X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=ssh.c;h=46b6013b905f9b85aa847d8e8d73a4504b7d5358;hb=2a2434e0cc91492ce56ce4360aacb7737bb1eebe;hp=ad9ccae4235c6e38c5794e8bd803629dfaaea0a2;hpb=3fa95b2a7fa8082ad0109959d601c9e664ecdf84;p=PuTTY.git diff --git a/ssh.c b/ssh.c index ad9ccae4..46b6013b 100644 --- a/ssh.c +++ b/ssh.c @@ -10,7 +10,9 @@ #include #include "putty.h" +#include "pageant.h" /* for AGENT_MAX_MSGLEN */ #include "tree234.h" +#include "storage.h" #include "ssh.h" #ifndef NO_GSSAPI #include "sshgssc.h" @@ -24,105 +26,6 @@ #define TRUE 1 #endif -#define SSH1_MSG_DISCONNECT 1 /* 0x1 */ -#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */ -#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */ -#define SSH1_CMSG_USER 4 /* 0x4 */ -#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */ -#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */ -#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */ -#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */ -#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */ -#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */ -#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */ -#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */ -#define SSH1_SMSG_SUCCESS 14 /* 0xe */ -#define SSH1_SMSG_FAILURE 15 /* 0xf */ -#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */ -#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */ -#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */ -#define SSH1_CMSG_EOF 19 /* 0x13 */ -#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */ -#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */ -#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */ -#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */ -#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */ -#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */ -#define SSH1_SMSG_X11_OPEN 27 /* 0x1b */ -#define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */ -#define SSH1_MSG_PORT_OPEN 29 /* 0x1d */ -#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */ -#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */ -#define SSH1_MSG_IGNORE 32 /* 0x20 */ -#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */ -#define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */ -#define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */ -#define SSH1_MSG_DEBUG 36 /* 0x24 */ -#define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */ -#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */ -#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */ -#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */ -#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */ -#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */ -#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */ - -#define SSH1_AUTH_RHOSTS 1 /* 0x1 */ -#define SSH1_AUTH_RSA 2 /* 0x2 */ -#define SSH1_AUTH_PASSWORD 3 /* 0x3 */ -#define SSH1_AUTH_RHOSTS_RSA 4 /* 0x4 */ -#define SSH1_AUTH_TIS 5 /* 0x5 */ -#define SSH1_AUTH_CCARD 16 /* 0x10 */ - -#define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */ -/* Mask for protoflags we will echo back to server if seen */ -#define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */ - -#define SSH2_MSG_DISCONNECT 1 /* 0x1 */ -#define SSH2_MSG_IGNORE 2 /* 0x2 */ -#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */ -#define SSH2_MSG_DEBUG 4 /* 0x4 */ -#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */ -#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */ -#define SSH2_MSG_KEXINIT 20 /* 0x14 */ -#define SSH2_MSG_NEWKEYS 21 /* 0x15 */ -#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */ -#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */ -#define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */ -#define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */ -#define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */ -#define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */ -#define SSH2_MSG_KEXRSA_PUBKEY 30 /* 0x1e */ -#define SSH2_MSG_KEXRSA_SECRET 31 /* 0x1f */ -#define SSH2_MSG_KEXRSA_DONE 32 /* 0x20 */ -#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */ -#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */ -#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */ -#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */ -#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */ -#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */ -#define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */ -#define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */ -#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */ -#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */ -#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */ -#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */ -#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */ -#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */ -#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */ -#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */ -#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */ -#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */ -#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */ -#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */ -#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */ -#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */ -#define SSH2_MSG_USERAUTH_GSSAPI_RESPONSE 60 -#define SSH2_MSG_USERAUTH_GSSAPI_TOKEN 61 -#define SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE 63 -#define SSH2_MSG_USERAUTH_GSSAPI_ERROR 64 -#define SSH2_MSG_USERAUTH_GSSAPI_ERRTOK 65 -#define SSH2_MSG_USERAUTH_GSSAPI_MIC 66 - /* * Packet type contexts, so that ssh2_pkt_type can correctly decode * the ambiguous type numbers back into the correct type strings. @@ -131,6 +34,7 @@ typedef enum { SSH2_PKTCTX_NOKEX, SSH2_PKTCTX_DHGROUP, SSH2_PKTCTX_DHGEX, + SSH2_PKTCTX_ECDHKEX, SSH2_PKTCTX_RSAKEX } Pkt_KCtx; typedef enum { @@ -141,22 +45,6 @@ typedef enum { SSH2_PKTCTX_KBDINTER } Pkt_ACtx; -#define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */ -#define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */ -#define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */ -#define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */ -#define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */ -#define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */ -#define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */ -#define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */ -#define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */ -#define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */ -#define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */ -#define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */ -#define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */ -#define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */ -#define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */ - static const char *const ssh2_disconnect_reasons[] = { NULL, "host not allowed to connect", @@ -176,13 +64,6 @@ static const char *const ssh2_disconnect_reasons[] = { "illegal user name", }; -#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */ -#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */ -#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */ -#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */ - -#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */ - /* * Various remote-bug flags. */ @@ -197,6 +78,11 @@ static const char *const ssh2_disconnect_reasons[] = { #define BUG_SSH2_MAXPKT 256 #define BUG_CHOKES_ON_SSH2_IGNORE 512 #define BUG_CHOKES_ON_WINADJ 1024 +#define BUG_SENDS_LATE_REQUEST_REPLY 2048 +#define BUG_SSH2_OLDGEX 4096 + +#define DH_MIN_SIZE 1024 +#define DH_MAX_SIZE 8192 /* * Codes for terminal modes. @@ -204,7 +90,7 @@ static const char *const ssh2_disconnect_reasons[] = { * This list is derived from RFC 4254 and * SSH-1 RFC-1.2.31. */ -static const struct { +static const struct ssh_ttymode { const char* const mode; int opcode; enum { TTY_OP_CHAR, TTY_OP_BOOL } type; @@ -240,6 +126,7 @@ static const struct { { "IXANY", 39, TTY_OP_BOOL }, { "IXOFF", 40, TTY_OP_BOOL }, { "IMAXBEL", 41, TTY_OP_BOOL }, + { "IUTF8", 42, TTY_OP_BOOL }, { "ISIG", 50, TTY_OP_BOOL }, { "ICANON", 51, TTY_OP_BOOL }, { "XCASE", 52, TTY_OP_BOOL }, @@ -305,7 +192,7 @@ static unsigned int ssh_tty_parse_boolean(char *s) #define translate(x) if (type == x) return #x #define translatek(x,ctx) if (type == x && (pkt_kctx == ctx)) return #x #define translatea(x,ctx) if (type == x && (pkt_actx == ctx)) return #x -static char *ssh1_pkt_type(int type) +static const char *ssh1_pkt_type(int type) { translate(SSH1_MSG_DISCONNECT); translate(SSH1_SMSG_PUBLIC_KEY); @@ -350,7 +237,8 @@ static char *ssh1_pkt_type(int type) translate(SSH1_CMSG_AUTH_CCARD_RESPONSE); return "unknown"; } -static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) +static const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, + int type) { translatea(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE,SSH2_PKTCTX_GSSAPI); translatea(SSH2_MSG_USERAUTH_GSSAPI_TOKEN,SSH2_PKTCTX_GSSAPI); @@ -368,6 +256,7 @@ static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) translate(SSH2_MSG_NEWKEYS); translatek(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP); translatek(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP); + translatek(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD, SSH2_PKTCTX_DHGEX); translatek(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX); translatek(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX); translatek(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX); @@ -375,6 +264,8 @@ static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) translatek(SSH2_MSG_KEXRSA_PUBKEY, SSH2_PKTCTX_RSAKEX); translatek(SSH2_MSG_KEXRSA_SECRET, SSH2_PKTCTX_RSAKEX); translatek(SSH2_MSG_KEXRSA_DONE, SSH2_PKTCTX_RSAKEX); + translatek(SSH2_MSG_KEX_ECDH_INIT, SSH2_PKTCTX_ECDHKEX); + translatek(SSH2_MSG_KEX_ECDH_REPLY, SSH2_PKTCTX_ECDHKEX); translate(SSH2_MSG_USERAUTH_REQUEST); translate(SSH2_MSG_USERAUTH_FAILURE); translate(SSH2_MSG_USERAUTH_SUCCESS); @@ -405,9 +296,6 @@ static char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type) /* Enumeration values for fields in SSH-1 packets */ enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM, - /* These values are for communicating relevant semantics of - * fields to the packet logging code. */ - PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA }; /* @@ -439,8 +327,8 @@ enum { #define crState(t) crStateP(t, ssh->t) #define crFinish(z) } *crLine = 0; return (z); } #define crFinishV } *crLine = 0; return; } -#define crFinishFree(z, s) } *crLine = 0; sfree(s); return (z); } -#define crFinishFreeV(s) } *crLine = 0; sfree(s); return; } +#define crFinishFree(z) } sfree(s); return (z); } +#define crFinishFreeV } sfree(s); return; } #define crReturn(z) \ do {\ *crLine =__LINE__; return (z); case __LINE__:;\ @@ -454,32 +342,37 @@ enum { #define crWaitUntil(c) do { crReturn(0); } while (!(c)) #define crWaitUntilV(c) do { crReturnV; } while (!(c)) -typedef struct ssh_tag *Ssh; struct Packet; static struct Packet *ssh1_pkt_init(int pkt_type); static struct Packet *ssh2_pkt_init(int pkt_type); static void ssh_pkt_ensure(struct Packet *, int length); -static void ssh_pkt_adddata(struct Packet *, void *data, int len); +static void ssh_pkt_adddata(struct Packet *, const void *data, int len); static void ssh_pkt_addbyte(struct Packet *, unsigned char value); static void ssh2_pkt_addbool(struct Packet *, unsigned char value); static void ssh_pkt_adduint32(struct Packet *, unsigned long value); static void ssh_pkt_addstring_start(struct Packet *); -static void ssh_pkt_addstring_str(struct Packet *, char *data); -static void ssh_pkt_addstring_data(struct Packet *, char *data, int len); -static void ssh_pkt_addstring(struct Packet *, char *data); +static void ssh_pkt_addstring_str(struct Packet *, const char *data); +static void ssh_pkt_addstring_data(struct Packet *, const char *data, int len); +static void ssh_pkt_addstring(struct Packet *, const char *data); static unsigned char *ssh2_mpint_fmt(Bignum b, int *len); static void ssh1_pkt_addmp(struct Packet *, Bignum b); static void ssh2_pkt_addmp(struct Packet *, Bignum b); static int ssh2_pkt_construct(Ssh, struct Packet *); static void ssh2_pkt_send(Ssh, struct Packet *); static void ssh2_pkt_send_noqueue(Ssh, struct Packet *); -static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, +static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen, struct Packet *pktin); -static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, +static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen, struct Packet *pktin); +static void ssh_channel_init(struct ssh_channel *c); +static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin); +static void ssh_channel_got_eof(struct ssh_channel *c); static void ssh2_channel_check_close(struct ssh_channel *c); +static void ssh_channel_close_local(struct ssh_channel *c, char const *reason); static void ssh_channel_destroy(struct ssh_channel *c); +static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize); +static void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin); /* * Buffer management constants. There are several of these for @@ -498,7 +391,7 @@ static void ssh_channel_destroy(struct ssh_channel *c); * ensure that the server never has any need to throttle its end * of the connection), so we set this high as well. * - * - OUR_V2_WINSIZE is the maximum window size we present on SSH-2 + * - OUR_V2_WINSIZE is the default window size we present on SSH-2 * channels. * * - OUR_V2_BIGWIN is the window size we advertise for the only @@ -522,12 +415,23 @@ static void ssh_channel_destroy(struct ssh_channel *c); #define OUR_V2_MAXPKT 0x4000UL #define OUR_V2_PACKETLIMIT 0x9000UL -const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss }; +struct ssh_signkey_with_user_pref_id { + const struct ssh_signkey *alg; + int id; +}; +const static struct ssh_signkey_with_user_pref_id hostkey_algs[] = { + { &ssh_ecdsa_ed25519, HK_ED25519 }, + { &ssh_ecdsa_nistp256, HK_ECDSA }, + { &ssh_ecdsa_nistp384, HK_ECDSA }, + { &ssh_ecdsa_nistp521, HK_ECDSA }, + { &ssh_dss, HK_DSA }, + { &ssh_rsa, HK_RSA }, +}; -const static struct ssh_mac *macs[] = { - &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 +const static struct ssh_mac *const macs[] = { + &ssh_hmac_sha256, &ssh_hmac_sha1, &ssh_hmac_sha1_96, &ssh_hmac_md5 }; -const static struct ssh_mac *buggymacs[] = { +const static struct ssh_mac *const buggymacs[] = { &ssh_hmac_sha1_buggy, &ssh_hmac_sha1_96_buggy, &ssh_hmac_md5 }; @@ -554,7 +458,7 @@ const static struct ssh_compress ssh_comp_none = { ssh_comp_none_disable, NULL }; extern const struct ssh_compress ssh_zlib; -const static struct ssh_compress *compressions[] = { +const static struct ssh_compress *const compressions[] = { &ssh_zlib, &ssh_comp_none }; @@ -563,7 +467,14 @@ enum { /* channel types */ CHAN_X11, CHAN_AGENT, CHAN_SOCKDATA, - CHAN_SOCKDATA_DORMANT, /* one the remote hasn't confirmed */ + /* + * CHAN_SHARING indicates a channel which is tracked here on + * behalf of a connection-sharing downstream. We do almost nothing + * with these channels ourselves: all messages relating to them + * get thrown straight to sshshare.c and passed on almost + * unmodified to downstream. + */ + CHAN_SHARING, /* * CHAN_ZOMBIE is used to indicate a channel for which we've * already destroyed the local data source: for instance, if a @@ -588,14 +499,6 @@ struct outstanding_channel_request { struct outstanding_channel_request *next; }; -/* - * little structure to keep track of outstanding WINDOW_ADJUSTs - */ -struct winadj { - struct winadj *next; - unsigned size; -}; - /* * 2-3-4 tree storing channels. */ @@ -671,16 +574,19 @@ struct ssh_channel { } v; union { struct ssh_agent_channel { - unsigned char *message; - unsigned char msglen[4]; - unsigned lensofar, totallen; + bufchain inbuffer; + agent_pending_query *pending; } a; struct ssh_x11_channel { - Socket s; + struct X11Connection *xconn; + int initial; } x11; struct ssh_pfd_channel { - Socket s; + struct PortForwarding *pf; } pfd; + struct ssh_sharing_channel { + void *ctx; + } sharing; } u; }; @@ -715,12 +621,21 @@ struct ssh_portfwd; /* forward declaration */ struct ssh_rportfwd { unsigned sport, dport; - char dhost[256]; + char *shost, *dhost; char *sportdesc; + void *share_ctx; struct ssh_portfwd *pfrec; }; -#define free_rportfwd(pf) ( \ - ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) ) + +static void free_rportfwd(struct ssh_rportfwd *pf) +{ + if (pf) { + sfree(pf->sportdesc); + sfree(pf->shost); + sfree(pf->dhost); + sfree(pf); + } +} /* * Separately to the rportfwd tree (which is for looking up port @@ -737,41 +652,68 @@ struct ssh_portfwd { char *sserv, *dserv; struct ssh_rportfwd *remote; int addressfamily; - void *local; + struct PortListener *local; }; #define free_portfwd(pf) ( \ ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \ sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) ) struct Packet { - long length; /* length of `data' actually used */ + long length; /* length of packet: see below */ long forcepad; /* SSH-2: force padding to at least this length */ int type; /* only used for incoming packets */ unsigned long sequence; /* SSH-2 incoming sequence number */ unsigned char *data; /* allocated storage */ unsigned char *body; /* offset of payload within `data' */ - long savedpos; /* temporary index into `data' (for strings) */ + long savedpos; /* dual-purpose saved packet position: see below */ long maxlen; /* amount of storage allocated for `data' */ long encrypted_len; /* for SSH-2 total-size counting */ /* - * State associated with packet logging + * A note on the 'length' and 'savedpos' fields above. + * + * Incoming packets are set up so that pkt->length is measured + * relative to pkt->body, which itself points to a few bytes after + * pkt->data (skipping some uninteresting header fields including + * the packet type code). The ssh_pkt_get* functions all expect + * this setup, and they also use pkt->savedpos to indicate how far + * through the packet being decoded they've got - and that, too, + * is an offset from pkt->body rather than pkt->data. + * + * During construction of an outgoing packet, however, pkt->length + * is measured relative to the base pointer pkt->data, and + * pkt->body is not really used for anything until the packet is + * ready for sending. In this mode, pkt->savedpos is reused as a + * temporary variable by the addstring functions, which write out + * a string length field and then keep going back and updating it + * as more data is appended to the subsequent string data field; + * pkt->savedpos stores the offset (again relative to pkt->data) + * of the start of the string data field. */ - int logmode; - int nblanks; - struct logblank_t *blanks; + + /* Extra metadata used in SSH packet logging mode, allowing us to + * log in the packet header line that the packet came from a + * connection-sharing downstream and what if anything unusual was + * done to it. The additional_log_text field is expected to be a + * static string - it will not be freed. */ + unsigned downstream_id; + const char *additional_log_text; }; -static void ssh1_protocol(Ssh ssh, void *vin, int inlen, +static void ssh1_protocol(Ssh ssh, const void *vin, int inlen, struct Packet *pktin); -static void ssh2_protocol(Ssh ssh, void *vin, int inlen, +static void ssh2_protocol(Ssh ssh, const void *vin, int inlen, struct Packet *pktin); +static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen, + struct Packet *pktin); static void ssh1_protocol_setup(Ssh ssh); static void ssh2_protocol_setup(Ssh ssh); +static void ssh2_bare_connection_protocol_setup(Ssh ssh); static void ssh_size(void *handle, int width, int height); static void ssh_special(void *handle, Telnet_Special); static int ssh2_try_send(struct ssh_channel *c); -static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len); +static int ssh_send_channel_data(struct ssh_channel *c, + const char *buf, int len); static void ssh_throttle_all(Ssh ssh, int enable, int bufsize); static void ssh2_set_window(struct ssh_channel *c, int newwin); static int ssh_sendbuffer(void *handle); @@ -779,9 +721,9 @@ static int ssh_do_close(Ssh ssh, int notify_exit); static unsigned long ssh_pkt_getuint32(struct Packet *pkt); static int ssh2_pkt_getbool(struct Packet *pkt); static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length); -static void ssh2_timer(void *ctx, long now); -static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, - struct Packet *pktin); +static void ssh2_timer(void *ctx, unsigned long now); +static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen, + struct Packet *pktin); static void ssh2_msg_unexpected(Ssh ssh, struct Packet *pktin); struct rdpkt1_state_tag { @@ -801,6 +743,14 @@ struct rdpkt2_state_tag { struct Packet *pktin; }; +struct rdpkt2_bare_state_tag { + char length[4]; + long packetlen; + int i; + unsigned long incoming_sequence; + struct Packet *pktin; +}; + struct queued_handler; struct queued_handler { int msg1, msg2; @@ -834,20 +784,27 @@ struct ssh_tag { const struct ssh2_cipher *cscipher, *sccipher; void *cs_cipher_ctx, *sc_cipher_ctx; const struct ssh_mac *csmac, *scmac; + int csmac_etm, scmac_etm; void *cs_mac_ctx, *sc_mac_ctx; const struct ssh_compress *cscomp, *sccomp; void *cs_comp_ctx, *sc_comp_ctx; const struct ssh_kex *kex; const struct ssh_signkey *hostkey; + char *hostkey_str; /* string representation, for easy checking in rekeys */ unsigned char v2_session_id[SSH2_KEX_MAX_HASH_LEN]; int v2_session_id_len; void *kex_ctx; + int bare_connection; + int attempting_connshare; + void *connshare; + char *savedhost; int savedport; int send_ok; int echoing, editing; + int session_started; void *frontend; int ospeed, ispeed; /* temporaries */ @@ -894,6 +851,8 @@ struct ssh_tag { Pkt_ACtx pkt_actx; struct X11Display *x11disp; + struct X11FakeAuth *x11auth; + tree234 *x11authtree; int version; int conn_throttle_count; @@ -904,6 +863,7 @@ struct ssh_tag { int ssh1_rdpkt_crstate; int ssh2_rdpkt_crstate; + int ssh2_bare_rdpkt_crstate; int ssh_gotdata_crstate; int do_ssh1_connection_crstate; @@ -911,16 +871,20 @@ struct ssh_tag { void *do_ssh1_login_state; void *do_ssh2_transport_state; void *do_ssh2_authconn_state; + void *do_ssh_connection_init_state; struct rdpkt1_state_tag rdpkt1_state; struct rdpkt2_state_tag rdpkt2_state; + struct rdpkt2_bare_state_tag rdpkt2_bare_state; /* SSH-1 and SSH-2 use this for different things, but both use it */ int protocol_initial_phase_done; - void (*protocol) (Ssh ssh, void *vin, int inlen, + void (*protocol) (Ssh ssh, const void *vin, int inlen, struct Packet *pkt); - struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen); + struct Packet *(*s_rdpkt) (Ssh ssh, const unsigned char **data, + int *datalen); + int (*do_ssh_init)(Ssh ssh, unsigned char c); /* * We maintain our own copy of a Conf structure here. That way, @@ -988,8 +952,8 @@ struct ssh_tag { unsigned long incoming_data_size, outgoing_data_size, deferred_data_size; unsigned long max_data_size; int kex_in_progress; - long next_rekey, last_rekey; - char *deferred_rekey_reason; /* points to STATIC string; don't free */ + unsigned long next_rekey, last_rekey; + const char *deferred_rekey_reason; /* * Fully qualified host name, which we need if doing GSSAPI. @@ -1002,8 +966,41 @@ struct ssh_tag { */ struct ssh_gss_liblist *gsslibs; #endif + + /* + * The last list returned from get_specials. + */ + struct telnet_special *specials; + + /* + * List of host key algorithms for which we _don't_ have a stored + * host key. These are indices into the main hostkey_algs[] array + */ + int uncert_hostkeys[lenof(hostkey_algs)]; + int n_uncert_hostkeys; + + /* + * Flag indicating that the current rekey is intended to finish + * with a newly cross-certified host key. + */ + int cross_certifying; + + /* + * Any asynchronous query to our SSH agent that we might have in + * flight from the main authentication loop. (Queries from + * agent-forwarding channels live in their channel structure.) + */ + agent_pending_query *auth_agent_query; }; +static const char *ssh_pkt_type(Ssh ssh, int type) +{ + if (ssh->version == 1) + return ssh1_pkt_type(type); + else + return ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, type); +} + #define logevent(s) logevent(ssh->frontend, s) /* logevent, only printf-formatted. */ @@ -1019,55 +1016,49 @@ static void logeventf(Ssh ssh, const char *fmt, ...) sfree(buf); } -#define bombout(msg) \ - do { \ - char *text = dupprintf msg; \ - ssh_do_close(ssh, FALSE); \ - logevent(text); \ - connection_fatal(ssh->frontend, "%s", text); \ - sfree(text); \ - } while (0) - -/* Functions to leave bits out of the SSH packet log file. */ - -static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype) -{ - if (conf_get_int(ssh->conf, CONF_logomitpass)) - pkt->logmode = blanktype; -} - -static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype) +static void bomb_out(Ssh ssh, char *text) { - if (ssh->logomitdata) - pkt->logmode = blanktype; + ssh_do_close(ssh, FALSE); + logevent(text); + connection_fatal(ssh->frontend, "%s", text); + sfree(text); } -static void end_log_omission(Ssh ssh, struct Packet *pkt) -{ - pkt->logmode = PKTLOG_EMIT; -} +#define bombout(msg) bomb_out(ssh, dupprintf msg) /* Helper function for common bits of parsing ttymodes. */ static void parse_ttymodes(Ssh ssh, - void (*do_mode)(void *data, char *mode, char *val), + void (*do_mode)(void *data, + const struct ssh_ttymode *mode, + char *val), void *data) { - char *key, *val; + int i; + const struct ssh_ttymode *mode; + char *val; + char default_val[2]; + + strcpy(default_val, "A"); + + for (i = 0; i < lenof(ssh_ttymodes); i++) { + mode = ssh_ttymodes + i; + val = conf_get_str_str_opt(ssh->conf, CONF_ttymodes, mode->mode); + if (!val) + val = default_val; - for (val = conf_get_str_strs(ssh->conf, CONF_ttymodes, NULL, &key); - val != NULL; - val = conf_get_str_strs(ssh->conf, CONF_ttymodes, key, &key)) { /* * val[0] is either 'V', indicating that an explicit value * follows it, or 'A' indicating that we should pass the * value through from the local environment via get_ttymode. */ - if (val[0] == 'A') - val = get_ttymode(ssh->frontend, key); - else - val++; /* skip the 'V' */ - if (val) - do_mode(data, key, val); + if (val[0] == 'A') { + val = get_ttymode(ssh->frontend, mode->mode); + if (val) { + do_mode(data, mode, val); + sfree(val); + } + } else + do_mode(data, mode, val + 1); /* skip the 'V' */ } } @@ -1110,7 +1101,9 @@ static int ssh_rportcmp_ssh2(void *av, void *bv) { struct ssh_rportfwd *a = (struct ssh_rportfwd *) av; struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv; - + int i; + if ( (i = strcmp(a->shost, b->shost)) != 0) + return i < 0 ? -1 : +1; if (a->sport > b->sport) return +1; if (a->sport < b->sport) @@ -1241,13 +1234,119 @@ static struct Packet *ssh_new_packet(void) pkt->body = pkt->data = NULL; pkt->maxlen = 0; - pkt->logmode = PKTLOG_EMIT; - pkt->nblanks = 0; - pkt->blanks = NULL; return pkt; } +static void ssh1_log_incoming_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH1_SMSG_STDOUT_DATA || + pkt->type == SSH1_SMSG_STDERR_DATA || + pkt->type == SSH1_MSG_CHANNEL_DATA)) { + /* "Session data" packets - omit the data string. */ + if (pkt->type == SSH1_MSG_CHANNEL_DATA) + ssh_pkt_getuint32(pkt); /* skip channel id */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + log_packet(ssh->logctx, PKT_INCOMING, pkt->type, + ssh1_pkt_type(pkt->type), + pkt->body, pkt->length, nblanks, blanks, NULL, + 0, NULL); +} + +static void ssh1_log_outgoing_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + /* + * For outgoing packets, pkt->length represents the length of the + * whole packet starting at pkt->data (including some header), and + * pkt->body refers to the point within that where the log-worthy + * payload begins. However, incoming packets expect pkt->length to + * represent only the payload length (that is, it's measured from + * pkt->body not from pkt->data). Temporarily adjust our outgoing + * packet to conform to the incoming-packet semantics, so that we + * can analyse it with the ssh_pkt_get functions. + */ + pkt->length -= (pkt->body - pkt->data); + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH1_CMSG_STDIN_DATA || + pkt->type == SSH1_MSG_CHANNEL_DATA)) { + /* "Session data" packets - omit the data string. */ + if (pkt->type == SSH1_MSG_CHANNEL_DATA) + ssh_pkt_getuint32(pkt); /* skip channel id */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + + if ((pkt->type == SSH1_CMSG_AUTH_PASSWORD || + pkt->type == SSH1_CMSG_AUTH_TIS_RESPONSE || + pkt->type == SSH1_CMSG_AUTH_CCARD_RESPONSE) && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* If this is a password or similar packet, blank the password(s). */ + blanks[nblanks].offset = 0; + blanks[nblanks].len = pkt->length; + blanks[nblanks].type = PKTLOG_BLANK; + nblanks++; + } else if (pkt->type == SSH1_CMSG_X11_REQUEST_FORWARDING && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* + * If this is an X forwarding request packet, blank the fake + * auth data. + * + * Note that while we blank the X authentication data here, we + * don't take any special action to blank the start of an X11 + * channel, so using MIT-MAGIC-COOKIE-1 and actually opening + * an X connection without having session blanking enabled is + * likely to leak your cookie into the log. + */ + pkt->savedpos = 0; + ssh_pkt_getstring(pkt, &str, &slen); + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + } + } + + log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12], + ssh1_pkt_type(pkt->data[12]), + pkt->body, pkt->length, + nblanks, blanks, NULL, 0, NULL); + + /* + * Undo the above adjustment of pkt->length, to put the packet + * back in the state we found it. + */ + pkt->length += (pkt->body - pkt->data); +} + /* * Collect incoming data in the incoming packet buffer. * Decipher and verify the packet when it is completely read. @@ -1255,7 +1354,8 @@ static struct Packet *ssh_new_packet(void) * Update the *data and *datalen variables. * Return a Packet structure when a packet is completed. */ -static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) +static struct Packet *ssh1_rdpkt(Ssh ssh, const unsigned char **data, + int *datalen) { struct rdpkt1_state_tag *st = &ssh->rdpkt1_state; @@ -1321,7 +1421,6 @@ static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) } st->pktin->body = st->pktin->data + st->pad + 1; - st->pktin->savedpos = 0; if (ssh->v1_compressing) { unsigned char *decompblk; @@ -1350,38 +1449,169 @@ static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen) st->pktin->type = st->pktin->body[-1]; /* - * Log incoming packet, possibly omitting sensitive fields. + * Now pktin->body and pktin->length identify the semantic content + * of the packet, excluding the initial type byte. */ - if (ssh->logctx) { - int nblanks = 0; - struct logblank_t blank; - if (ssh->logomitdata) { - int do_blank = FALSE, blank_prefix = 0; - /* "Session data" packets - omit the data field */ - if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) || - (st->pktin->type == SSH1_SMSG_STDERR_DATA)) { - do_blank = TRUE; blank_prefix = 4; - } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) { - do_blank = TRUE; blank_prefix = 8; - } - if (do_blank) { - blank.offset = blank_prefix; - blank.len = st->pktin->length; - blank.type = PKTLOG_OMIT; - nblanks = 1; - } - } - log_packet(ssh->logctx, - PKT_INCOMING, st->pktin->type, - ssh1_pkt_type(st->pktin->type), - st->pktin->body, st->pktin->length, - nblanks, &blank, NULL); - } + + if (ssh->logctx) + ssh1_log_incoming_packet(ssh, st->pktin); + + st->pktin->savedpos = 0; crFinish(st->pktin); } -static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) +static void ssh2_log_incoming_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH2_MSG_CHANNEL_DATA || + pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) { + /* "Session data" packets - omit the data string. */ + ssh_pkt_getuint32(pkt); /* skip channel id */ + if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) + ssh_pkt_getuint32(pkt); /* skip extended data type */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + + log_packet(ssh->logctx, PKT_INCOMING, pkt->type, + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->type), + pkt->body, pkt->length, nblanks, blanks, &pkt->sequence, + 0, NULL); +} + +static void ssh2_log_outgoing_packet(Ssh ssh, struct Packet *pkt) +{ + int nblanks = 0; + struct logblank_t blanks[4]; + char *str; + int slen; + + /* + * For outgoing packets, pkt->length represents the length of the + * whole packet starting at pkt->data (including some header), and + * pkt->body refers to the point within that where the log-worthy + * payload begins. However, incoming packets expect pkt->length to + * represent only the payload length (that is, it's measured from + * pkt->body not from pkt->data). Temporarily adjust our outgoing + * packet to conform to the incoming-packet semantics, so that we + * can analyse it with the ssh_pkt_get functions. + */ + pkt->length -= (pkt->body - pkt->data); + pkt->savedpos = 0; + + if (ssh->logomitdata && + (pkt->type == SSH2_MSG_CHANNEL_DATA || + pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA)) { + /* "Session data" packets - omit the data string. */ + ssh_pkt_getuint32(pkt); /* skip channel id */ + if (pkt->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) + ssh_pkt_getuint32(pkt); /* skip extended data type */ + blanks[nblanks].offset = pkt->savedpos + 4; + blanks[nblanks].type = PKTLOG_OMIT; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = slen; + nblanks++; + } + } + + if (pkt->type == SSH2_MSG_USERAUTH_REQUEST && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* If this is a password packet, blank the password(s). */ + pkt->savedpos = 0; + ssh_pkt_getstring(pkt, &str, &slen); + ssh_pkt_getstring(pkt, &str, &slen); + ssh_pkt_getstring(pkt, &str, &slen); + if (slen == 8 && !memcmp(str, "password", 8)) { + ssh2_pkt_getbool(pkt); + /* Blank the password field. */ + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + /* If there's another password field beyond it (change of + * password), blank that too. */ + ssh_pkt_getstring(pkt, &str, &slen); + if (str) + blanks[nblanks-1].len = + pkt->savedpos - blanks[nblanks].offset; + } + } + } else if (ssh->pkt_actx == SSH2_PKTCTX_KBDINTER && + pkt->type == SSH2_MSG_USERAUTH_INFO_RESPONSE && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* If this is a keyboard-interactive response packet, blank + * the responses. */ + pkt->savedpos = 0; + ssh_pkt_getuint32(pkt); + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + while (1) { + ssh_pkt_getstring(pkt, &str, &slen); + if (!str) + break; + } + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + } else if (pkt->type == SSH2_MSG_CHANNEL_REQUEST && + conf_get_int(ssh->conf, CONF_logomitpass)) { + /* + * If this is an X forwarding request packet, blank the fake + * auth data. + * + * Note that while we blank the X authentication data here, we + * don't take any special action to blank the start of an X11 + * channel, so using MIT-MAGIC-COOKIE-1 and actually opening + * an X connection without having session blanking enabled is + * likely to leak your cookie into the log. + */ + pkt->savedpos = 0; + ssh_pkt_getuint32(pkt); + ssh_pkt_getstring(pkt, &str, &slen); + if (slen == 7 && !memcmp(str, "x11-req", 0)) { + ssh2_pkt_getbool(pkt); + ssh2_pkt_getbool(pkt); + ssh_pkt_getstring(pkt, &str, &slen); + blanks[nblanks].offset = pkt->savedpos; + blanks[nblanks].type = PKTLOG_BLANK; + ssh_pkt_getstring(pkt, &str, &slen); + if (str) { + blanks[nblanks].len = pkt->savedpos - blanks[nblanks].offset; + nblanks++; + } + } + } + + log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], + ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]), + pkt->body, pkt->length, nblanks, blanks, + &ssh->v2_outgoing_sequence, + pkt->downstream_id, pkt->additional_log_text); + + /* + * Undo the above adjustment of pkt->length, to put the packet + * back in the state we found it. + */ + pkt->length += (pkt->body - pkt->data); +} + +static struct Packet *ssh2_rdpkt(Ssh ssh, const unsigned char **data, + int *datalen) { struct rdpkt2_state_tag *st = &ssh->rdpkt2_state; @@ -1400,7 +1630,7 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) st->maclen = ssh->scmac ? ssh->scmac->len : 0; if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_IS_CBC) && - ssh->scmac) { + ssh->scmac && !ssh->scmac_etm) { /* * When dealing with a CBC-mode cipher, we want to avoid the * possibility of an attacker's tweaking the ciphertext stream @@ -1412,6 +1642,11 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) * length, so we just read data and check the MAC repeatedly, * and when the MAC passes, see if the length we've got is * plausible. + * + * This defence is unnecessary in OpenSSH ETM mode, because + * the whole point of ETM mode is that the attacker can't + * tweak the ciphertext stream at all without the MAC + * detecting it before we decrypt anything. */ /* May as well allocate the whole lot now. */ @@ -1453,7 +1688,8 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) /* See if that gives us a valid packet. */ if (ssh->scmac->verresult(ssh->sc_mac_ctx, st->pktin->data + st->packetlen) && - (st->len = GET_32BIT(st->pktin->data)) + 4 == st->packetlen) + ((st->len = toint(GET_32BIT(st->pktin->data))) == + st->packetlen-4)) break; if (st->packetlen >= OUR_V2_PACKETLIMIT) { bombout(("No valid incoming packet found")); @@ -1465,6 +1701,80 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) st->pktin->data = sresize(st->pktin->data, st->pktin->maxlen + APIEXTRA, unsigned char); + } else if (ssh->scmac && ssh->scmac_etm) { + st->pktin->data = snewn(4 + APIEXTRA, unsigned char); + + /* + * OpenSSH encrypt-then-MAC mode: the packet length is + * unencrypted, unless the cipher supports length encryption. + */ + for (st->i = st->len = 0; st->i < 4; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + /* Cipher supports length decryption, so do it */ + if (ssh->sccipher && (ssh->sccipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) { + /* Keep the packet the same though, so the MAC passes */ + unsigned char len[4]; + memcpy(len, st->pktin->data, 4); + ssh->sccipher->decrypt_length(ssh->sc_cipher_ctx, len, 4, st->incoming_sequence); + st->len = toint(GET_32BIT(len)); + } else { + st->len = toint(GET_32BIT(st->pktin->data)); + } + + /* + * _Completely_ silly lengths should be stomped on before they + * do us any more damage. + */ + if (st->len < 0 || st->len > OUR_V2_PACKETLIMIT || + st->len % st->cipherblk != 0) { + bombout(("Incoming packet length field was garbled")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + /* + * So now we can work out the total packet length. + */ + st->packetlen = st->len + 4; + + /* + * Allocate memory for the rest of the packet. + */ + st->pktin->maxlen = st->packetlen + st->maclen; + st->pktin->data = sresize(st->pktin->data, + st->pktin->maxlen + APIEXTRA, + unsigned char); + + /* + * Read the remainder of the packet. + */ + for (st->i = 4; st->i < st->packetlen + st->maclen; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; + } + + /* + * Check the MAC. + */ + if (ssh->scmac + && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, + st->len + 4, st->incoming_sequence)) { + bombout(("Incorrect MAC received on packet")); + ssh_free_packet(st->pktin); + crStop(NULL); + } + + /* Decrypt everything between the length field and the MAC. */ + if (ssh->sccipher) + ssh->sccipher->decrypt(ssh->sc_cipher_ctx, + st->pktin->data + 4, + st->packetlen - 4); } else { st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char); @@ -1486,7 +1796,7 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) /* * Now get the length figure. */ - st->len = GET_32BIT(st->pktin->data); + st->len = toint(GET_32BIT(st->pktin->data)); /* * _Completely_ silly lengths should be stomped on before they @@ -1556,6 +1866,9 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) st->pktin->sequence = st->incoming_sequence++; + st->pktin->length = st->packetlen - st->pad; + assert(st->pktin->length >= 0); + /* * Decompress packet payload. */ @@ -1578,38 +1891,89 @@ static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen) } } - st->pktin->savedpos = 6; - st->pktin->body = st->pktin->data; + /* + * RFC 4253 doesn't explicitly say that completely empty packets + * with no type byte are forbidden, so treat them as deserving + * an SSH_MSG_UNIMPLEMENTED. + */ + if (st->pktin->length <= 5) { /* == 5 we hope, but robustness */ + ssh2_msg_something_unimplemented(ssh, st->pktin); + crStop(NULL); + } + /* + * pktin->body and pktin->length should identify the semantic + * content of the packet, excluding the initial type byte. + */ st->pktin->type = st->pktin->data[5]; + st->pktin->body = st->pktin->data + 6; + st->pktin->length -= 6; + assert(st->pktin->length >= 0); /* one last double-check */ + + if (ssh->logctx) + ssh2_log_incoming_packet(ssh, st->pktin); + + st->pktin->savedpos = 0; + + crFinish(st->pktin); +} + +static struct Packet *ssh2_bare_connection_rdpkt(Ssh ssh, + const unsigned char **data, + int *datalen) +{ + struct rdpkt2_bare_state_tag *st = &ssh->rdpkt2_bare_state; + + crBegin(ssh->ssh2_bare_rdpkt_crstate); /* - * Log incoming packet, possibly omitting sensitive fields. + * Read the packet length field. */ - if (ssh->logctx) { - int nblanks = 0; - struct logblank_t blank; - if (ssh->logomitdata) { - int do_blank = FALSE, blank_prefix = 0; - /* "Session data" packets - omit the data field */ - if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) { - do_blank = TRUE; blank_prefix = 8; - } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) { - do_blank = TRUE; blank_prefix = 12; - } - if (do_blank) { - blank.offset = blank_prefix; - blank.len = (st->pktin->length-6) - blank_prefix; - blank.type = PKTLOG_OMIT; - nblanks = 1; - } - } - log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type, - ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, - st->pktin->type), - st->pktin->data+6, st->pktin->length-6, - nblanks, &blank, &st->pktin->sequence); + for (st->i = 0; st->i < 4; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->length[st->i] = *(*data)++; + (*datalen)--; + } + + st->packetlen = toint(GET_32BIT_MSB_FIRST(st->length)); + if (st->packetlen <= 0 || st->packetlen >= OUR_V2_PACKETLIMIT) { + bombout(("Invalid packet length received")); + crStop(NULL); + } + + st->pktin = ssh_new_packet(); + st->pktin->data = snewn(st->packetlen, unsigned char); + + st->pktin->encrypted_len = st->packetlen; + + st->pktin->sequence = st->incoming_sequence++; + + /* + * Read the remainder of the packet. + */ + for (st->i = 0; st->i < st->packetlen; st->i++) { + while ((*datalen) == 0) + crReturn(NULL); + st->pktin->data[st->i] = *(*data)++; + (*datalen)--; } + /* + * pktin->body and pktin->length should identify the semantic + * content of the packet, excluding the initial type byte. + */ + st->pktin->type = st->pktin->data[0]; + st->pktin->body = st->pktin->data + 1; + st->pktin->length = st->packetlen - 1; + + /* + * Log incoming packet, possibly omitting sensitive fields. + */ + if (ssh->logctx) + ssh2_log_incoming_packet(ssh, st->pktin); + + st->pktin->savedpos = 0; + crFinish(st->pktin); } @@ -1629,12 +1993,7 @@ static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt, int *offset_p) int len; if (ssh->logctx) - log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[12], - ssh1_pkt_type(pkt->data[12]), - pkt->body, pkt->length - (pkt->body - pkt->data), - pkt->nblanks, pkt->blanks, NULL); - sfree(pkt->blanks); pkt->blanks = NULL; - pkt->nblanks = 0; + ssh1_log_outgoing_packet(ssh, pkt); if (ssh->v1_compressing) { unsigned char *compblk; @@ -1673,7 +2032,9 @@ static int s_write(Ssh ssh, void *data, int len) { if (ssh->logctx) log_packet(ssh->logctx, PKT_OUTGOING, -1, NULL, data, len, - 0, NULL, NULL); + 0, NULL, NULL, 0, NULL); + if (!ssh->s) + return 0; return sk_write(ssh->s, (char *)data, len); } @@ -1744,16 +2105,6 @@ static struct Packet *construct_packet(Ssh ssh, int pkttype, va_list ap) bn = va_arg(ap, Bignum); ssh1_pkt_addmp(pkt, bn); break; - /* Tokens for modifications to packet logging */ - case PKTT_PASSWORD: - dont_log_password(ssh, pkt, PKTLOG_BLANK); - break; - case PKTT_DATA: - dont_log_data(ssh, pkt, PKTLOG_OMIT); - break; - case PKTT_OTHER: - end_log_omission(ssh, pkt); - break; } } @@ -1780,7 +2131,7 @@ static void defer_packet(Ssh ssh, int pkttype, ...) s_wrpkt_defer(ssh, pkt); } -static int ssh_versioncmp(char *a, char *b) +static int ssh_versioncmp(const char *a, const char *b) { char *ae, *be; unsigned long av, bv; @@ -1832,17 +2183,8 @@ static void ssh_pkt_ensure(struct Packet *pkt, int length) if (body) pkt->body = pkt->data + offset; } } -static void ssh_pkt_adddata(struct Packet *pkt, void *data, int len) +static void ssh_pkt_adddata(struct Packet *pkt, const void *data, int len) { - if (pkt->logmode != PKTLOG_EMIT) { - pkt->nblanks++; - pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t); - assert(pkt->body); - pkt->blanks[pkt->nblanks-1].offset = pkt->length - - (pkt->body - pkt->data); - pkt->blanks[pkt->nblanks-1].len = len; - pkt->blanks[pkt->nblanks-1].type = pkt->logmode; - } pkt->length += len; ssh_pkt_ensure(pkt, pkt->length); memcpy(pkt->data + pkt->length - len, data, len); @@ -1866,17 +2208,17 @@ static void ssh_pkt_addstring_start(struct Packet *pkt) ssh_pkt_adduint32(pkt, 0); pkt->savedpos = pkt->length; } -static void ssh_pkt_addstring_str(struct Packet *pkt, char *data) +static void ssh_pkt_addstring_data(struct Packet *pkt, const char *data, + int len) { - ssh_pkt_adddata(pkt, data, strlen(data)); + ssh_pkt_adddata(pkt, data, len); PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); } -static void ssh_pkt_addstring_data(struct Packet *pkt, char *data, int len) +static void ssh_pkt_addstring_str(struct Packet *pkt, const char *data) { - ssh_pkt_adddata(pkt, data, len); - PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos); + ssh_pkt_addstring_data(pkt, data, strlen(data)); } -static void ssh_pkt_addstring(struct Packet *pkt, char *data) +static void ssh_pkt_addstring(struct Packet *pkt, const char *data) { ssh_pkt_addstring_start(pkt); ssh_pkt_addstring_str(pkt, data); @@ -1920,6 +2262,9 @@ static struct Packet *ssh1_pkt_init(int pkt_type) pkt->length = 4 + 8; /* space for length + max padding */ ssh_pkt_addbyte(pkt, pkt_type); pkt->body = pkt->data + pkt->length; + pkt->type = pkt_type; + pkt->downstream_id = 0; + pkt->additional_log_text = NULL; return pkt; } @@ -1938,8 +2283,11 @@ static struct Packet *ssh2_pkt_init(int pkt_type) struct Packet *pkt = ssh_new_packet(); pkt->length = 5; /* space for packet length + padding length */ pkt->forcepad = 0; + pkt->type = pkt_type; ssh_pkt_addbyte(pkt, (unsigned char) pkt_type); pkt->body = pkt->data + pkt->length; /* after packet type */ + pkt->downstream_id = 0; + pkt->additional_log_text = NULL; return pkt; } @@ -1950,15 +2298,21 @@ static struct Packet *ssh2_pkt_init(int pkt_type) */ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) { - int cipherblk, maclen, padding, i; + int cipherblk, maclen, padding, unencrypted_prefix, i; if (ssh->logctx) - log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5], - ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, pkt->data[5]), - pkt->body, pkt->length - (pkt->body - pkt->data), - pkt->nblanks, pkt->blanks, &ssh->v2_outgoing_sequence); - sfree(pkt->blanks); pkt->blanks = NULL; - pkt->nblanks = 0; + ssh2_log_outgoing_packet(ssh, pkt); + + if (ssh->bare_connection) { + /* + * Trivial packet construction for the bare connection + * protocol. + */ + PUT_32BIT(pkt->data + 1, pkt->length - 5); + pkt->body = pkt->data + 1; + ssh->v2_outgoing_sequence++; /* only for diagnostics, really */ + return pkt->length - 1; + } /* * Compress packet payload. @@ -1985,10 +2339,12 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */ cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */ padding = 4; + unencrypted_prefix = (ssh->csmac && ssh->csmac_etm) ? 4 : 0; if (pkt->length + padding < pkt->forcepad) padding = pkt->forcepad - pkt->length; padding += - (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk; + (cipherblk - (pkt->length - unencrypted_prefix + padding) % cipherblk) + % cipherblk; assert(padding <= 255); maclen = ssh->csmac ? ssh->csmac->len : 0; ssh2_pkt_ensure(pkt, pkt->length + padding + maclen); @@ -1996,19 +2352,41 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt) for (i = 0; i < padding; i++) pkt->data[pkt->length + i] = random_byte(); PUT_32BIT(pkt->data, pkt->length + padding - 4); - if (ssh->csmac) - ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, - pkt->length + padding, - ssh->v2_outgoing_sequence); - ssh->v2_outgoing_sequence++; /* whether or not we MACed */ - if (ssh->cscipher) - ssh->cscipher->encrypt(ssh->cs_cipher_ctx, - pkt->data, pkt->length + padding); + /* Encrypt length if the scheme requires it */ + if (ssh->cscipher && (ssh->cscipher->flags & SSH_CIPHER_SEPARATE_LENGTH)) { + ssh->cscipher->encrypt_length(ssh->cs_cipher_ctx, pkt->data, 4, + ssh->v2_outgoing_sequence); + } + if (ssh->csmac && ssh->csmac_etm) { + /* + * OpenSSH-defined encrypt-then-MAC protocol. + */ + if (ssh->cscipher) + ssh->cscipher->encrypt(ssh->cs_cipher_ctx, + pkt->data + 4, pkt->length + padding - 4); + ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, + pkt->length + padding, + ssh->v2_outgoing_sequence); + } else { + /* + * SSH-2 standard protocol. + */ + if (ssh->csmac) + ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data, + pkt->length + padding, + ssh->v2_outgoing_sequence); + if (ssh->cscipher) + ssh->cscipher->encrypt(ssh->cs_cipher_ctx, + pkt->data, pkt->length + padding); + } + + ssh->v2_outgoing_sequence++; /* whether or not we MACed */ pkt->encrypted_len = pkt->length + padding; /* Ready-to-send packet starts at pkt->data. We return length. */ + pkt->body = pkt->data; return pkt->length + padding + maclen; } @@ -2066,12 +2444,13 @@ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt) return; } len = ssh2_pkt_construct(ssh, pkt); - backlog = s_write(ssh, pkt->data, len); + backlog = s_write(ssh, pkt->body, len); if (backlog > SSH_MAX_BACKLOG) ssh_throttle_all(ssh, 1, backlog); ssh->outgoing_data_size += pkt->encrypted_len; if (!ssh->kex_in_progress && + !ssh->bare_connection && ssh->max_data_size != 0 && ssh->outgoing_data_size > ssh->max_data_size) do_ssh2_transport(ssh, "too much data sent", -1, NULL); @@ -2103,7 +2482,7 @@ static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt, int noignore) ssh->deferred_size, unsigned char); } - memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len); + memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->body, len); ssh->deferred_len += len; ssh->deferred_data_size += pkt->encrypted_len; ssh_free_packet(pkt); @@ -2171,12 +2550,15 @@ static void ssh_pkt_defersend(Ssh ssh) if (backlog > SSH_MAX_BACKLOG) ssh_throttle_all(ssh, 1, backlog); - ssh->outgoing_data_size += ssh->deferred_data_size; - if (!ssh->kex_in_progress && - ssh->max_data_size != 0 && - ssh->outgoing_data_size > ssh->max_data_size) - do_ssh2_transport(ssh, "too much data sent", -1, NULL); - ssh->deferred_data_size = 0; + if (ssh->version == 2) { + ssh->outgoing_data_size += ssh->deferred_data_size; + ssh->deferred_data_size = 0; + if (!ssh->kex_in_progress && + !ssh->bare_connection && + ssh->max_data_size != 0 && + ssh->outgoing_data_size > ssh->max_data_size) + do_ssh2_transport(ssh, "too much data sent", -1, NULL); + } } /* @@ -2317,7 +2699,7 @@ static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length) *length = 0; if (pkt->length - pkt->savedpos < 4) return; - len = GET_32BIT(pkt->body + pkt->savedpos); + len = toint(GET_32BIT(pkt->body + pkt->savedpos)); if (len < 0) return; *length = len; @@ -2335,7 +2717,7 @@ static void *ssh_pkt_getdata(struct Packet *pkt, int length) return pkt->body + (pkt->savedpos - length); } static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key, - unsigned char **keystr) + const unsigned char **keystr) { int j; @@ -2401,7 +2783,7 @@ static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, * See if this is in fact an ssh-rsa signature and a buggy * server; otherwise we can just do this the easy way. */ - if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && + if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) && pkblob_len > 4+7+4 && (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) { int pos, len, siglen; @@ -2410,8 +2792,15 @@ static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, */ pos = 4+7; /* skip over "ssh-rsa" */ - pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */ - len = GET_32BIT(pkblob+pos); /* find length of modulus */ + len = toint(GET_32BIT(pkblob+pos)); /* get length of exponent */ + if (len < 0 || len > pkblob_len - pos - 4) + goto give_up; + pos += 4 + len; /* skip over exponent */ + if (pkblob_len - pos < 4) + goto give_up; + len = toint(GET_32BIT(pkblob+pos)); /* find length of modulus */ + if (len < 0 || len > pkblob_len - pos - 4) + goto give_up; pos += 4; /* find modulus itself */ while (len > 0 && pkblob[pos] == 0) len--, pos++; @@ -2421,7 +2810,11 @@ static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, * Now find the signature integer. */ pos = 4+7; /* skip over "ssh-rsa" */ - siglen = GET_32BIT(sigblob+pos); + if (sigblob_len < pos+4) + goto give_up; + siglen = toint(GET_32BIT(sigblob+pos)); + if (siglen != sigblob_len - pos - 4) + goto give_up; /* debug(("signature length is %d\n", siglen)); */ if (len != siglen) { @@ -2443,7 +2836,10 @@ static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt, return; } - /* Otherwise fall through and do it the easy way. */ + /* Otherwise fall through and do it the easy way. We also come + * here as a fallback if we discover above that the key blob + * is misformatted in some way. */ + give_up:; } ssh2_pkt_addstring_start(pkt); @@ -2540,7 +2936,9 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) if (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == FORCE_ON || (conf_get_int(ssh->conf, CONF_sshbug_rsapad2) == AUTO && (wc_match("OpenSSH_2.[5-9]*", imp) || - wc_match("OpenSSH_3.[0-2]*", imp)))) { + wc_match("OpenSSH_3.[0-2]*", imp) || + wc_match("mod_sftp/0.[0-8]*", imp) || + wc_match("mod_sftp/0.9.[0-8]", imp)))) { /* * These versions have the SSH-2 RSA padding bug. */ @@ -2595,6 +2993,18 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) logevent("We believe remote version has SSH-2 ignore bug"); } + if (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_oldgex2) == AUTO && + (wc_match("OpenSSH_2.[235]*", imp)))) { + /* + * These versions only support the original (pre-RFC4419) + * SSH-2 GEX request, and disconnect with a protocol error if + * we use the newer version. + */ + ssh->remote_bugs |= BUG_SSH2_OLDGEX; + logevent("We believe remote version has outdated SSH-2 GEX"); + } + if (conf_get_int(ssh->conf, CONF_sshbug_winadj) == FORCE_ON) { /* * Servers that don't support our winadj request for one @@ -2603,6 +3013,23 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) ssh->remote_bugs |= BUG_CHOKES_ON_WINADJ; logevent("We believe remote version has winadj bug"); } + + if (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == FORCE_ON || + (conf_get_int(ssh->conf, CONF_sshbug_chanreq) == AUTO && + (wc_match("OpenSSH_[2-5].*", imp) || + wc_match("OpenSSH_6.[0-6]*", imp) || + wc_match("dropbear_0.[2-4][0-9]*", imp) || + wc_match("dropbear_0.5[01]*", imp)))) { + /* + * These versions have the SSH-2 channel request bug. + * OpenSSH 6.7 and above do not: + * https://bugzilla.mindrot.org/show_bug.cgi?id=1818 + * dropbear_0.52 and above do not: + * https://secure.ucc.asn.au/hg/dropbear/rev/cd02449b709c + */ + ssh->remote_bugs |= BUG_SENDS_LATE_REQUEST_REPLY; + logevent("We believe remote version has SSH-2 channel request bug"); + } } /* @@ -2611,11 +3038,7 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring) */ static void ssh_fix_verstring(char *str) { - /* Eat "SSH--". */ - assert(*str == 'S'); str++; - assert(*str == 'S'); str++; - assert(*str == 'H'); str++; - assert(*str == '-'); str++; + /* Eat "-". */ while (*str && *str != '-') str++; assert(*str == '-'); str++; @@ -2631,7 +3054,7 @@ static void ssh_fix_verstring(char *str) /* * Send an appropriate SSH version string. */ -static void ssh_send_verstring(Ssh ssh, char *svers) +static void ssh_send_verstring(Ssh ssh, const char *protoname, char *svers) { char *verstring; @@ -2639,18 +3062,23 @@ static void ssh_send_verstring(Ssh ssh, char *svers) /* * Construct a v2 version string. */ - verstring = dupprintf("SSH-2.0-%s\015\012", sshver); + verstring = dupprintf("%s2.0-%s\015\012", protoname, sshver); } else { /* * Construct a v1 version string. */ + assert(!strcmp(protoname, "SSH-")); /* no v1 bare connection protocol */ verstring = dupprintf("SSH-%s-%s\012", (ssh_versioncmp(svers, "1.5") <= 0 ? svers : "1.5"), sshver); } - ssh_fix_verstring(verstring); + ssh_fix_verstring(verstring + strlen(protoname)); +#ifdef FUZZING + /* FUZZING make PuTTY insecure, so make live use difficult. */ + verstring[0] = 'I'; +#endif if (ssh->version == 2) { size_t len; @@ -2671,6 +3099,8 @@ static void ssh_send_verstring(Ssh ssh, char *svers) static int do_ssh_init(Ssh ssh, unsigned char c) { + static const char protoname[] = "SSH-"; + struct do_ssh_init_state { int crLine; int vslen; @@ -2684,15 +3114,13 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crBeginState; - /* Search for a line beginning with the string "SSH-" in the input. */ + /* Search for a line beginning with the protocol name prefix in + * the input. */ for (;;) { - if (c != 'S') goto no; - crReturn(1); - if (c != 'S') goto no; - crReturn(1); - if (c != 'H') goto no; - crReturn(1); - if (c != '-') goto no; + for (s->i = 0; protoname[s->i]; s->i++) { + if ((char)c != protoname[s->i]) goto no; + crReturn(1); + } break; no: while (c != '\012') @@ -2700,13 +3128,14 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crReturn(1); } - s->vstrsize = 16; + ssh->session_started = TRUE; + + s->vstrsize = sizeof(protoname) + 16; s->vstring = snewn(s->vstrsize, char); - strcpy(s->vstring, "SSH-"); - s->vslen = 4; + strcpy(s->vstring, protoname); + s->vslen = strlen(protoname); s->i = 0; while (1) { - crReturn(1); /* get another char */ if (s->vslen >= s->vstrsize - 1) { s->vstrsize += 16; s->vstring = sresize(s->vstring, s->vstrsize, char); @@ -2720,6 +3149,7 @@ static int do_ssh_init(Ssh ssh, unsigned char c) s->version[s->i++] = c; } else if (c == '\012') break; + crReturn(1); /* get another char */ } ssh->agentfwd_enabled = FALSE; @@ -2739,13 +3169,21 @@ static int do_ssh_init(Ssh ssh, unsigned char c) /* Anything greater or equal to "1.99" means protocol 2 is supported. */ s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0; - if (conf_get_int(ssh->conf, CONF_sshprot) == 0 && !s->proto1) { - bombout(("SSH protocol version 1 required by user but not provided by server")); - crStop(0); - } - if (conf_get_int(ssh->conf, CONF_sshprot) == 3 && !s->proto2) { - bombout(("SSH protocol version 2 required by user but not provided by server")); - crStop(0); + if (conf_get_int(ssh->conf, CONF_sshprot) == 0) { + if (!s->proto1) { + bombout(("SSH protocol version 1 required by our configuration " + "but not provided by server")); + crStop(0); + } + } else if (conf_get_int(ssh->conf, CONF_sshprot) == 3) { + if (!s->proto2) { + bombout(("SSH protocol version 2 required by our configuration " + "but server only provides (old, insecure) SSH-1")); + crStop(0); + } + } else { + /* No longer support values 1 or 2 for CONF_sshprot */ + assert(!"Unexpected value for CONF_sshprot"); } if (s->proto2 && (conf_get_int(ssh->conf, CONF_sshprot) >= 2 || !s->proto1)) @@ -2757,7 +3195,7 @@ static int do_ssh_init(Ssh ssh, unsigned char c) /* Send the version string, if we haven't already */ if (conf_get_int(ssh->conf, CONF_sshprot) != 3) - ssh_send_verstring(ssh, s->version); + ssh_send_verstring(ssh, protoname, s->version); if (ssh->version == 2) { size_t len; @@ -2795,8 +3233,119 @@ static int do_ssh_init(Ssh ssh, unsigned char c) crFinish(0); } +static int do_ssh_connection_init(Ssh ssh, unsigned char c) +{ + /* + * Ordinary SSH begins with the banner "SSH-x.y-...". This is just + * the ssh-connection part, extracted and given a trivial binary + * packet protocol, so we replace 'SSH-' at the start with a new + * name. In proper SSH style (though of course this part of the + * proper SSH protocol _isn't_ subject to this kind of + * DNS-domain-based extension), we define the new name in our + * extension space. + */ + static const char protoname[] = + "SSHCONNECTION@putty.projects.tartarus.org-"; + + struct do_ssh_connection_init_state { + int crLine; + int vslen; + char version[10]; + char *vstring; + int vstrsize; + int i; + }; + crState(do_ssh_connection_init_state); + + crBeginState; + + /* Search for a line beginning with the protocol name prefix in + * the input. */ + for (;;) { + for (s->i = 0; protoname[s->i]; s->i++) { + if ((char)c != protoname[s->i]) goto no; + crReturn(1); + } + break; + no: + while (c != '\012') + crReturn(1); + crReturn(1); + } + + s->vstrsize = sizeof(protoname) + 16; + s->vstring = snewn(s->vstrsize, char); + strcpy(s->vstring, protoname); + s->vslen = strlen(protoname); + s->i = 0; + while (1) { + if (s->vslen >= s->vstrsize - 1) { + s->vstrsize += 16; + s->vstring = sresize(s->vstring, s->vstrsize, char); + } + s->vstring[s->vslen++] = c; + if (s->i >= 0) { + if (c == '-') { + s->version[s->i] = '\0'; + s->i = -1; + } else if (s->i < sizeof(s->version) - 1) + s->version[s->i++] = c; + } else if (c == '\012') + break; + crReturn(1); /* get another char */ + } + + ssh->agentfwd_enabled = FALSE; + ssh->rdpkt2_bare_state.incoming_sequence = 0; + + s->vstring[s->vslen] = 0; + s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */ + logeventf(ssh, "Server version: %s", s->vstring); + ssh_detect_bugs(ssh, s->vstring); + + /* + * Decide which SSH protocol version to support. This is easy in + * bare ssh-connection mode: only 2.0 is legal. + */ + if (ssh_versioncmp(s->version, "2.0") < 0) { + bombout(("Server announces compatibility with SSH-1 in bare ssh-connection protocol")); + crStop(0); + } + if (conf_get_int(ssh->conf, CONF_sshprot) == 0) { + bombout(("Bare ssh-connection protocol cannot be run in SSH-1-only mode")); + crStop(0); + } + + ssh->version = 2; + + logeventf(ssh, "Using bare ssh-connection protocol"); + + /* Send the version string, if we haven't already */ + ssh_send_verstring(ssh, protoname, s->version); + + /* + * Initialise bare connection protocol. + */ + ssh->protocol = ssh2_bare_connection_protocol; + ssh2_bare_connection_protocol_setup(ssh); + ssh->s_rdpkt = ssh2_bare_connection_rdpkt; + + update_specials_menu(ssh->frontend); + ssh->state = SSH_STATE_BEFORE_SIZE; + ssh->pinger = pinger_new(ssh->conf, &ssh_backend, ssh); + + /* + * Get authconn (really just conn) under way. + */ + do_ssh2_authconn(ssh, NULL, 0, NULL); + + sfree(s->vstring); + + crFinish(0); +} + static void ssh_process_incoming_data(Ssh ssh, - unsigned char **data, int *datalen) + const unsigned char **data, int *datalen) { struct Packet *pktin; @@ -2808,7 +3357,7 @@ static void ssh_process_incoming_data(Ssh ssh, } static void ssh_queue_incoming_data(Ssh ssh, - unsigned char **data, int *datalen) + const unsigned char **data, int *datalen) { bufchain_add(&ssh->queued_incoming_data, *data, *datalen); *data += *datalen; @@ -2818,7 +3367,7 @@ static void ssh_queue_incoming_data(Ssh ssh, static void ssh_process_queued_incoming_data(Ssh ssh) { void *vdata; - unsigned char *data; + const unsigned char *data; int len, origlen; while (!ssh->frozen && bufchain_size(&ssh->queued_incoming_data)) { @@ -2841,12 +3390,12 @@ static void ssh_set_frozen(Ssh ssh, int frozen) ssh->frozen = frozen; } -static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) +static void ssh_gotdata(Ssh ssh, const unsigned char *data, int datalen) { /* Log raw data, if we're in that mode. */ if (ssh->logctx) log_packet(ssh->logctx, PKT_INCOMING, -1, NULL, data, datalen, - 0, NULL, NULL); + 0, NULL, NULL, 0, NULL); crBegin(ssh->ssh_gotdata_crstate); @@ -2860,7 +3409,7 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen) int ret; /* need not be kept across crReturn */ if (datalen == 0) crReturnV; /* more data please */ - ret = do_ssh_init(ssh, *data); + ret = ssh->do_ssh_init(ssh, *data); data++; datalen--; if (ret == 0) @@ -2922,15 +3471,7 @@ static int ssh_do_close(Ssh ssh, int notify_exit) */ if (ssh->channels) { while (NULL != (c = index234(ssh->channels, 0))) { - switch (c->type) { - case CHAN_X11: - x11_close(c->u.x11.s); - break; - case CHAN_SOCKDATA: - case CHAN_SOCKDATA_DORMANT: - pfd_close(c->u.pfd.s); - break; - } + ssh_channel_close_local(c, NULL); del234(ssh->channels, c); /* moving next one to index 0 */ if (ssh->version == 2) bufchain_clear(&c->v.v2.outbuffer); @@ -2946,7 +3487,7 @@ static int ssh_do_close(Ssh ssh, int notify_exit) while (NULL != (pf = index234(ssh->portfwds, 0))) { /* Dispose of any listening socket. */ if (pf->local) - pfd_terminate(pf->local); + pfl_terminate(pf->local); del234(ssh->portfwds, pf); /* moving next one to index 0 */ free_portfwd(pf); } @@ -2954,24 +3495,68 @@ static int ssh_do_close(Ssh ssh, int notify_exit) ssh->portfwds = NULL; } + /* + * Also stop attempting to connection-share. + */ + if (ssh->connshare) { + sharestate_free(ssh->connshare); + ssh->connshare = NULL; + } + return ret; } -static void ssh_log(Plug plug, int type, SockAddr addr, int port, - const char *error_msg, int error_code) +static void ssh_socket_log(Plug plug, int type, SockAddr addr, int port, + const char *error_msg, int error_code) { Ssh ssh = (Ssh) plug; - char addrbuf[256], *msg; - sk_getaddr(addr, addrbuf, lenof(addrbuf)); + /* + * While we're attempting connection sharing, don't loudly log + * everything that happens. Real TCP connections need to be logged + * when we _start_ trying to connect, because it might be ages + * before they respond if something goes wrong; but connection + * sharing is local and quick to respond, and it's sufficient to + * simply wait and see whether it worked afterwards. + */ - if (type == 0) - msg = dupprintf("Connecting to %s port %d", addrbuf, port); - else - msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg); + if (!ssh->attempting_connshare) + backend_socket_log(ssh->frontend, type, addr, port, + error_msg, error_code, ssh->conf, + ssh->session_started); +} - logevent(msg); - sfree(msg); +void ssh_connshare_log(Ssh ssh, int event, const char *logtext, + const char *ds_err, const char *us_err) +{ + if (event == SHARE_NONE) { + /* In this case, 'logtext' is an error message indicating a + * reason why connection sharing couldn't be set up _at all_. + * Failing that, ds_err and us_err indicate why we couldn't be + * a downstream and an upstream respectively. */ + if (logtext) { + logeventf(ssh, "Could not set up connection sharing: %s", logtext); + } else { + if (ds_err) + logeventf(ssh, "Could not set up connection sharing" + " as downstream: %s", ds_err); + if (us_err) + logeventf(ssh, "Could not set up connection sharing" + " as upstream: %s", us_err); + } + } else if (event == SHARE_DOWNSTREAM) { + /* In this case, 'logtext' is a local endpoint address */ + logeventf(ssh, "Using existing shared connection at %s", logtext); + /* Also we should mention this in the console window to avoid + * confusing users as to why this window doesn't behave the + * usual way. */ + if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) { + c_write_str(ssh,"Reusing a shared connection to this server.\r\n"); + } + } else if (event == SHARE_UPSTREAM) { + /* In this case, 'logtext' is a local endpoint address too */ + logeventf(ssh, "Sharing this connection at %s", logtext); + } } static int ssh_closing(Plug plug, const char *error_msg, int error_code, @@ -3022,17 +3607,69 @@ static void ssh_sent(Plug plug, int bufsize) ssh_throttle_all(ssh, 0, bufsize); } +static void ssh_hostport_setup(const char *host, int port, Conf *conf, + char **savedhost, int *savedport, + char **loghost_ret) +{ + char *loghost = conf_get_str(conf, CONF_loghost); + if (loghost_ret) + *loghost_ret = loghost; + + if (*loghost) { + char *tmphost; + char *colon; + + tmphost = dupstr(loghost); + *savedport = 22; /* default ssh port */ + + /* + * A colon suffix on the hostname string also lets us affect + * savedport. (Unless there are multiple colons, in which case + * we assume this is an unbracketed IPv6 literal.) + */ + colon = host_strrchr(tmphost, ':'); + if (colon && colon == host_strchr(tmphost, ':')) { + *colon++ = '\0'; + if (*colon) + *savedport = atoi(colon); + } + + *savedhost = host_strduptrim(tmphost); + sfree(tmphost); + } else { + *savedhost = host_strduptrim(host); + if (port < 0) + port = 22; /* default ssh port */ + *savedport = port; + } +} + +static int ssh_test_for_upstream(const char *host, int port, Conf *conf) +{ + char *savedhost; + int savedport; + int ret; + + random_ref(); /* platform may need this to determine share socket name */ + ssh_hostport_setup(host, port, conf, &savedhost, &savedport, NULL); + ret = ssh_share_test_for_upstream(savedhost, savedport, conf); + sfree(savedhost); + random_unref(); + + return ret; +} + /* * Connect to specified host and port. * Returns an error message, or NULL on success. * Also places the canonical host name into `realhost'. It must be * freed by the caller. */ -static const char *connect_to_host(Ssh ssh, char *host, int port, +static const char *connect_to_host(Ssh ssh, const char *host, int port, char **realhost, int nodelay, int keepalive) { static const struct plug_function_table fn_table = { - ssh_log, + ssh_socket_log, ssh_closing, ssh_receive, ssh_sent, @@ -3043,69 +3680,76 @@ static const char *connect_to_host(Ssh ssh, char *host, int port, const char *err; char *loghost; int addressfamily, sshprot; - - loghost = conf_get_str(ssh->conf, CONF_loghost); - if (*loghost) { - char *colon; - ssh->savedhost = dupstr(loghost); - ssh->savedport = 22; /* default ssh port */ + ssh_hostport_setup(host, port, ssh->conf, + &ssh->savedhost, &ssh->savedport, &loghost); - /* - * A colon suffix on savedhost also lets us affect - * savedport. - * - * (FIXME: do something about IPv6 address literals here.) - */ - colon = strrchr(ssh->savedhost, ':'); - if (colon) { - *colon++ = '\0'; - if (*colon) - ssh->savedport = atoi(colon); - } - } else { - ssh->savedhost = dupstr(host); - if (port < 0) - port = 22; /* default ssh port */ - ssh->savedport = port; - } + ssh->fn = &fn_table; /* make 'ssh' usable as a Plug */ /* - * Try to find host. + * Try connection-sharing, in case that means we don't open a + * socket after all. ssh_connection_sharing_init will connect to a + * previously established upstream if it can, and failing that, + * establish a listening socket for _us_ to be the upstream. In + * the latter case it will return NULL just as if it had done + * nothing, because here we only need to care if we're a + * downstream and need to do our connection setup differently. */ - addressfamily = conf_get_int(ssh->conf, CONF_addressfamily); - logeventf(ssh, "Looking up host \"%s\"%s", host, - (addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" : - (addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : ""))); - addr = name_lookup(host, port, realhost, ssh->conf, addressfamily); - if ((err = sk_addr_error(addr)) != NULL) { - sk_addr_free(addr); - return err; - } - ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */ + ssh->connshare = NULL; + ssh->attempting_connshare = TRUE; /* affects socket logging behaviour */ + ssh->s = ssh_connection_sharing_init(ssh->savedhost, ssh->savedport, + ssh->conf, ssh, &ssh->connshare); + ssh->attempting_connshare = FALSE; + if (ssh->s != NULL) { + /* + * We are a downstream. + */ + ssh->bare_connection = TRUE; + ssh->do_ssh_init = do_ssh_connection_init; + ssh->fullhostname = NULL; + *realhost = dupstr(host); /* best we can do */ + } else { + /* + * We're not a downstream, so open a normal socket. + */ + ssh->do_ssh_init = do_ssh_init; - /* - * Open socket. - */ - ssh->fn = &fn_table; - ssh->s = new_connection(addr, *realhost, port, - 0, 1, nodelay, keepalive, (Plug) ssh, ssh->conf); - if ((err = sk_socket_error(ssh->s)) != NULL) { - ssh->s = NULL; - notify_remote_exit(ssh->frontend); - return err; + /* + * Try to find host. + */ + addressfamily = conf_get_int(ssh->conf, CONF_addressfamily); + addr = name_lookup(host, port, realhost, ssh->conf, addressfamily, + ssh->frontend, "SSH connection"); + if ((err = sk_addr_error(addr)) != NULL) { + sk_addr_free(addr); + return err; + } + ssh->fullhostname = dupstr(*realhost); /* save in case of GSSAPI */ + + ssh->s = new_connection(addr, *realhost, port, + 0, 1, nodelay, keepalive, + (Plug) ssh, ssh->conf); + if ((err = sk_socket_error(ssh->s)) != NULL) { + ssh->s = NULL; + notify_remote_exit(ssh->frontend); + return err; + } } /* - * If the SSH version number's fixed, set it now, and if it's SSH-2, - * send the version string too. + * The SSH version number is always fixed (since we no longer support + * fallback between versions), so set it now, and if it's SSH-2, + * send the version string now too. */ sshprot = conf_get_int(ssh->conf, CONF_sshprot); + assert(sshprot == 0 || sshprot == 3); if (sshprot == 0) + /* SSH-1 only */ ssh->version = 1; - if (sshprot == 3) { + if (sshprot == 3 && !ssh->bare_connection) { + /* SSH-2 only */ ssh->version = 2; - ssh_send_verstring(ssh, NULL); + ssh_send_verstring(ssh, "SSH-", NULL); } /* @@ -3134,6 +3778,8 @@ static void ssh_throttle_conn(Ssh ssh, int adjust) } } +static void ssh_agentf_try_forward(struct ssh_channel *c); + /* * Throttle or unthrottle _all_ local data streams (for when sends * on the SSH connection itself back up). @@ -3157,13 +3803,18 @@ static void ssh_throttle_all(Ssh ssh, int enable, int bufsize) */ break; case CHAN_X11: - x11_override_throttle(c->u.x11.s, enable); + x11_override_throttle(c->u.x11.xconn, enable); break; case CHAN_AGENT: - /* Agent channels require no buffer management. */ + /* Agent forwarding channels are buffer-managed by + * checking ssh->throttled_all in ssh_agentf_try_forward. + * So at the moment we _un_throttle again, we must make an + * attempt to do something. */ + if (!enable) + ssh_agentf_try_forward(c); break; case CHAN_SOCKDATA: - pfd_override_throttle(c->u.pfd.s, enable); + pfd_override_throttle(c->u.pfd.pf, enable); break; } } @@ -3173,6 +3824,8 @@ static void ssh_agent_callback(void *sshv, void *reply, int replylen) { Ssh ssh = (Ssh) sshv; + ssh->auth_agent_query = NULL; + ssh->agent_response = reply; ssh->agent_response_len = replylen; @@ -3200,31 +3853,138 @@ static void ssh_dialog_callback(void *sshv, int ret) ssh_process_queued_incoming_data(ssh); } -static void ssh_agentf_callback(void *cv, void *reply, int replylen) +static void ssh_agentf_got_response(struct ssh_channel *c, + void *reply, int replylen) { - struct ssh_channel *c = (struct ssh_channel *)cv; - Ssh ssh = c->ssh; - void *sentreply = reply; + c->u.a.pending = NULL; + + assert(!(c->closes & CLOSES_SENT_EOF)); - if (!sentreply) { - /* Fake SSH_AGENT_FAILURE. */ - sentreply = "\0\0\0\1\5"; + if (!reply) { + /* The real agent didn't send any kind of reply at all for + * some reason, so fake an SSH_AGENT_FAILURE. */ + reply = "\0\0\0\1\5"; replylen = 5; } - if (ssh->version == 2) { - ssh2_add_channel_data(c, sentreply, replylen); - ssh2_try_send(c); - } else { - send_packet(ssh, SSH1_MSG_CHANNEL_DATA, - PKT_INT, c->remoteid, - PKT_INT, replylen, - PKTT_DATA, - PKT_DATA, sentreply, replylen, - PKTT_OTHER, - PKT_END); + + ssh_send_channel_data(c, reply, replylen); +} + +static void ssh_agentf_callback(void *cv, void *reply, int replylen); + +static void ssh_agentf_try_forward(struct ssh_channel *c) +{ + unsigned datalen, lengthfield, messagelen; + unsigned char *message; + unsigned char msglen[4]; + void *reply; + int replylen; + + /* + * Don't try to parallelise agent requests. Wait for each one to + * return before attempting the next. + */ + if (c->u.a.pending) + return; + + /* + * If the outgoing side of the channel connection is currently + * throttled (for any reason, either that channel's window size or + * the entire SSH connection being throttled), don't submit any + * new forwarded requests to the real agent. This causes the input + * side of the agent forwarding not to be emptied, exerting the + * required back-pressure on the remote client, and encouraging it + * to read our responses before sending too many more requests. + */ + if (c->ssh->throttled_all || + (c->ssh->version == 2 && c->v.v2.remwindow == 0)) + return; + + if (c->closes & CLOSES_SENT_EOF) { + /* + * If we've already sent outgoing EOF, there's nothing we can + * do with incoming data except consume it and throw it away. + */ + bufchain_clear(&c->u.a.inbuffer); + return; + } + + while (1) { + /* + * Try to extract a complete message from the input buffer. + */ + datalen = bufchain_size(&c->u.a.inbuffer); + if (datalen < 4) + break; /* not even a length field available yet */ + + bufchain_fetch(&c->u.a.inbuffer, msglen, 4); + lengthfield = GET_32BIT(msglen); + + if (lengthfield > AGENT_MAX_MSGLEN) { + /* + * If the remote has sent a message that's just _too_ + * long, we should reject it in advance of seeing the rest + * of the incoming message, and also close the connection + * for good measure (which avoids us having to faff about + * with carefully ignoring just the right number of bytes + * from the overlong message). + */ + ssh_agentf_got_response(c, NULL, 0); + sshfwd_write_eof(c); + return; + } + + if (lengthfield > datalen - 4) + break; /* a whole message is not yet available */ + + messagelen = lengthfield + 4; + + message = snewn(messagelen, unsigned char); + bufchain_fetch(&c->u.a.inbuffer, message, messagelen); + bufchain_consume(&c->u.a.inbuffer, messagelen); + c->u.a.pending = agent_query( + message, messagelen, &reply, &replylen, ssh_agentf_callback, c); + sfree(message); + + if (c->u.a.pending) + return; /* agent_query promised to reply in due course */ + + /* + * If the agent gave us an answer immediately, pass it + * straight on and go round this loop again. + */ + ssh_agentf_got_response(c, reply, replylen); + sfree(reply); } - if (reply) - sfree(reply); + + /* + * If we get here (i.e. we left the above while loop via 'break' + * rather than 'return'), that means we've determined that the + * input buffer for the agent forwarding connection doesn't + * contain a complete request. + * + * So if there's potentially more data to come, we can return now, + * and wait for the remote client to send it. But if the remote + * has sent EOF, it would be a mistake to do that, because we'd be + * waiting a long time. So this is the moment to check for EOF, + * and respond appropriately. + */ + if (c->closes & CLOSES_RCVD_EOF) + sshfwd_write_eof(c); +} + +static void ssh_agentf_callback(void *cv, void *reply, int replylen) +{ + struct ssh_channel *c = (struct ssh_channel *)cv; + + ssh_agentf_got_response(c, reply, replylen); + sfree(reply); + + /* + * Now try to extract and send further messages from the channel's + * input-side buffer. + */ + ssh_agentf_try_forward(c); } /* @@ -3232,7 +3992,8 @@ static void ssh_agentf_callback(void *cv, void *reply, int replylen) * non-NULL, otherwise just close the connection. `client_reason' == NULL * => log `wire_reason'. */ -static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, +static void ssh_disconnect(Ssh ssh, const char *client_reason, + const char *wire_reason, int code, int clean_exit) { char *error; @@ -3260,20 +4021,73 @@ static void ssh_disconnect(Ssh ssh, char *client_reason, char *wire_reason, sfree(error); } +int verify_ssh_manual_host_key(Ssh ssh, const char *fingerprint, + const struct ssh_signkey *ssh2keytype, + void *ssh2keydata) +{ + if (!conf_get_str_nthstrkey(ssh->conf, CONF_ssh_manual_hostkeys, 0)) { + return -1; /* no manual keys configured */ + } + + if (fingerprint) { + /* + * The fingerprint string we've been given will have things + * like 'ssh-rsa 2048' at the front of it. Strip those off and + * narrow down to just the colon-separated hex block at the + * end of the string. + */ + const char *p = strrchr(fingerprint, ' '); + fingerprint = p ? p+1 : fingerprint; + /* Quick sanity checks, including making sure it's in lowercase */ + assert(strlen(fingerprint) == 16*3 - 1); + assert(fingerprint[2] == ':'); + assert(fingerprint[strspn(fingerprint, "0123456789abcdef:")] == 0); + + if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys, + fingerprint)) + return 1; /* success */ + } + + if (ssh2keydata) { + /* + * Construct the base64-encoded public key blob and see if + * that's listed. + */ + unsigned char *binblob; + char *base64blob; + int binlen, atoms, i; + binblob = ssh2keytype->public_blob(ssh2keydata, &binlen); + atoms = (binlen + 2) / 3; + base64blob = snewn(atoms * 4 + 1, char); + for (i = 0; i < atoms; i++) + base64_encode_atom(binblob + 3*i, binlen - 3*i, base64blob + 4*i); + base64blob[atoms * 4] = '\0'; + sfree(binblob); + if (conf_get_str_str_opt(ssh->conf, CONF_ssh_manual_hostkeys, + base64blob)) { + sfree(base64blob); + return 1; /* success */ + } + sfree(base64blob); + } + + return 0; +} + /* * Handle the key exchange and user authentication phases. */ -static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, +static int do_ssh1_login(Ssh ssh, const unsigned char *in, int inlen, struct Packet *pktin) { int i, j, ret; unsigned char cookie[8], *ptr; - struct RSAKey servkey, hostkey; struct MD5Context md5c; struct do_ssh1_login_state { int crLine; int len; - unsigned char *rsabuf, *keystr1, *keystr2; + unsigned char *rsabuf; + const unsigned char *keystr1, *keystr2; unsigned long supported_ciphers_mask, supported_auths_mask; int tried_publickey, tried_agent; int tis_auth_refused, ccard_auth_refused; @@ -3282,7 +4096,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, void *publickey_blob; int publickey_bloblen; char *publickey_comment; - int publickey_encrypted; + int privatekey_available, privatekey_encrypted; prompts_t *cur_prompt; char c; int pwpkt_type; @@ -3296,6 +4110,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int commentlen; int dlgret; Filename *keyfile; + struct RSAKey servkey, hostkey; }; crState(do_ssh1_login_state); @@ -3318,8 +4133,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, } memcpy(cookie, ptr, 8); - if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) || - !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) { + if (!ssh1_pkt_getrsakey(pktin, &s->servkey, &s->keystr1) || + !ssh1_pkt_getrsakey(pktin, &s->hostkey, &s->keystr2)) { bombout(("Failed to read SSH-1 public keys from public key packet")); crStop(0); } @@ -3331,9 +4146,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, char logmsg[80]; logevent("Host key fingerprint is:"); strcpy(logmsg, " "); - hostkey.comment = NULL; + s->hostkey.comment = NULL; rsa_fingerprint(logmsg + strlen(logmsg), - sizeof(logmsg) - strlen(logmsg), &hostkey); + sizeof(logmsg) - strlen(logmsg), &s->hostkey); logevent(logmsg); } @@ -3348,8 +4163,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER; MD5Init(&md5c); - MD5Update(&md5c, s->keystr2, hostkey.bytes); - MD5Update(&md5c, s->keystr1, servkey.bytes); + MD5Update(&md5c, s->keystr2, s->hostkey.bytes); + MD5Update(&md5c, s->keystr1, s->servkey.bytes); MD5Update(&md5c, cookie, 8); MD5Final(s->session_id, &md5c); @@ -3359,13 +4174,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, /* * Verify that the `bits' and `bytes' parameters match. */ - if (hostkey.bits > hostkey.bytes * 8 || - servkey.bits > servkey.bytes * 8) { + if (s->hostkey.bits > s->hostkey.bytes * 8 || + s->servkey.bits > s->servkey.bytes * 8) { bombout(("SSH-1 public keys were badly formatted")); crStop(0); } - s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes); + s->len = (s->hostkey.bytes > s->servkey.bytes ? + s->hostkey.bytes : s->servkey.bytes); s->rsabuf = snewn(s->len, unsigned char); @@ -3376,35 +4192,48 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, /* * First format the key into a string. */ - int len = rsastr_len(&hostkey); + int len = rsastr_len(&s->hostkey); char fingerprint[100]; char *keystr = snewn(len, char); - rsastr_fmt(keystr, &hostkey); - rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey); - - ssh_set_frozen(ssh, 1); - s->dlgret = verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, - "rsa", keystr, fingerprint, - ssh_dialog_callback, ssh); - sfree(keystr); - if (s->dlgret < 0) { - do { - crReturn(0); - if (pktin) { - bombout(("Unexpected data from server while waiting" - " for user host key response")); - crStop(0); - } - } while (pktin || inlen > 0); - s->dlgret = ssh->user_response; - } - ssh_set_frozen(ssh, 0); + rsastr_fmt(keystr, &s->hostkey); + rsa_fingerprint(fingerprint, sizeof(fingerprint), &s->hostkey); + + /* First check against manually configured host keys. */ + s->dlgret = verify_ssh_manual_host_key(ssh, fingerprint, NULL, NULL); + if (s->dlgret == 0) { /* did not match */ + bombout(("Host key did not appear in manually configured list")); + sfree(keystr); + crStop(0); + } else if (s->dlgret < 0) { /* none configured; use standard handling */ + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + "rsa", keystr, fingerprint, + ssh_dialog_callback, ssh); + sfree(keystr); +#ifdef FUZZING + s->dlgret = 1; +#endif + if (s->dlgret < 0) { + do { + crReturn(0); + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStop(0); + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); - if (s->dlgret == 0) { - ssh_disconnect(ssh, "User aborted at host key verification", - NULL, 0, TRUE); - crStop(0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at host key verification", + NULL, 0, TRUE); + crStop(0); + } + } else { + sfree(keystr); } } @@ -3414,14 +4243,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->rsabuf[i] ^= s->session_id[i]; } - if (hostkey.bytes > servkey.bytes) { - ret = rsaencrypt(s->rsabuf, 32, &servkey); + if (s->hostkey.bytes > s->servkey.bytes) { + ret = rsaencrypt(s->rsabuf, 32, &s->servkey); if (ret) - ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey); + ret = rsaencrypt(s->rsabuf, s->servkey.bytes, &s->hostkey); } else { - ret = rsaencrypt(s->rsabuf, 32, &hostkey); + ret = rsaencrypt(s->rsabuf, 32, &s->hostkey); if (ret) - ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey); + ret = rsaencrypt(s->rsabuf, s->hostkey.bytes, &s->servkey); } if (!ret) { bombout(("SSH-1 public key encryptions failed due to bad formatting")); @@ -3432,7 +4261,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, { int cipher_chosen = 0, warn = 0; - char *cipher_string = NULL; + const char *cipher_string = NULL; int i; for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) { int next_cipher = conf_get_int_int(ssh->conf, @@ -3524,21 +4353,21 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ssh->crcda_ctx = crcda_make_context(); logevent("Installing CRC compensation attack detector"); - if (servkey.modulus) { - sfree(servkey.modulus); - servkey.modulus = NULL; + if (s->servkey.modulus) { + sfree(s->servkey.modulus); + s->servkey.modulus = NULL; } - if (servkey.exponent) { - sfree(servkey.exponent); - servkey.exponent = NULL; + if (s->servkey.exponent) { + sfree(s->servkey.exponent); + s->servkey.exponent = NULL; } - if (hostkey.modulus) { - sfree(hostkey.modulus); - hostkey.modulus = NULL; + if (s->hostkey.modulus) { + sfree(s->hostkey.modulus); + s->hostkey.modulus = NULL; } - if (hostkey.exponent) { - sfree(hostkey.exponent); - hostkey.exponent = NULL; + if (s->hostkey.exponent) { + sfree(s->hostkey.exponent); + s->hostkey.exponent = NULL; } crWaitUntil(pktin); @@ -3604,20 +4433,24 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); if (!filename_is_null(s->keyfile)) { int keytype; - logeventf(ssh, "Reading private key file \"%.150s\"", + logeventf(ssh, "Reading key file \"%.150s\"", filename_to_str(s->keyfile)); keytype = key_type(s->keyfile); - if (keytype == SSH_KEYTYPE_SSH1) { + if (keytype == SSH_KEYTYPE_SSH1 || + keytype == SSH_KEYTYPE_SSH1_PUBLIC) { const char *error; if (rsakey_pubblob(s->keyfile, &s->publickey_blob, &s->publickey_bloblen, &s->publickey_comment, &error)) { - s->publickey_encrypted = rsakey_encrypted(s->keyfile, - NULL); + s->privatekey_available = (keytype == SSH_KEYTYPE_SSH1); + if (!s->privatekey_available) + logeventf(ssh, "Key file contains public key only"); + s->privatekey_encrypted = rsakey_encrypted(s->keyfile, + NULL); } else { char *msgbuf; - logeventf(ssh, "Unable to load private key (%s)", error); - msgbuf = dupprintf("Unable to load private key file " + logeventf(ssh, "Unable to load key (%s)", error); + msgbuf = dupprintf("Unable to load key file " "\"%.150s\" (%s)\r\n", filename_to_str(s->keyfile), error); @@ -3656,8 +4489,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, /* Request the keys held by the agent. */ PUT_32BIT(s->request, 1); s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES; - if (!agent_query(s->request, 5, &r, &s->responselen, - ssh_agent_callback, ssh)) { + ssh->auth_agent_query = agent_query( + s->request, 5, &r, &s->responselen, ssh_agent_callback, ssh); + if (ssh->auth_agent_query) { do { crReturn(0); if (pktin) { @@ -3673,7 +4507,12 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, if (s->response && s->responselen >= 5 && s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) { s->p = s->response + 5; - s->nkeys = GET_32BIT(s->p); + s->nkeys = toint(GET_32BIT(s->p)); + if (s->nkeys < 0) { + logeventf(ssh, "Pageant reported negative key count %d", + s->nkeys); + s->nkeys = 0; + } s->p += 4; logeventf(ssh, "Pageant has %d SSH-1 keys", s->nkeys); for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) { @@ -3683,22 +4522,23 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int n, ok = FALSE; do { /* do while (0) to make breaking easy */ n = ssh1_read_bignum - (s->p, s->responselen-(s->p-s->response), + (s->p, toint(s->responselen-(s->p-s->response)), &s->key.exponent); if (n < 0) break; s->p += n; n = ssh1_read_bignum - (s->p, s->responselen-(s->p-s->response), + (s->p, toint(s->responselen-(s->p-s->response)), &s->key.modulus); if (n < 0) - break; + break; s->p += n; if (s->responselen - (s->p-s->response) < 4) break; - s->commentlen = GET_32BIT(s->p); + s->commentlen = toint(GET_32BIT(s->p)); s->p += 4; - if (s->responselen - (s->p-s->response) < + if (s->commentlen < 0 || + toint(s->responselen - (s->p-s->response)) < s->commentlen) break; s->commentp = (char *)s->p; @@ -3756,8 +4596,10 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, memcpy(q, s->session_id, 16); q += 16; PUT_32BIT(q, 1); /* response format */ - if (!agent_query(agentreq, len + 4, &vret, &retlen, - ssh_agent_callback, ssh)) { + ssh->auth_agent_query = agent_query( + agentreq, len + 4, &vret, &retlen, + ssh_agent_callback, ssh); + if (ssh->auth_agent_query) { sfree(agentreq); do { crReturn(0); @@ -3819,7 +4661,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, if (s->authed) break; } - if (s->publickey_blob && !s->tried_publickey) { + if (s->publickey_blob && s->privatekey_available && + !s->tried_publickey) { /* * Try public key authentication with the specified * key file. @@ -3838,7 +4681,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, */ char *passphrase = NULL; /* only written after crReturn */ const char *error; - if (!s->publickey_encrypted) { + if (!s->privatekey_encrypted) { if (flags & FLAG_VERBOSE) c_write_str(ssh, "No passphrase required.\r\n"); passphrase = NULL; @@ -4152,9 +4995,8 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, for (i = bottom; i <= top; i++) { if (i == pwlen) { defer_packet(ssh, s->pwpkt_type, - PKTT_PASSWORD, PKT_STR, - s->cur_prompt->prompts[0]->result, - PKTT_OTHER, PKT_END); + PKT_STR,s->cur_prompt->prompts[0]->result, + PKT_END); } else { for (j = 0; j < i; j++) { do { @@ -4192,9 +5034,9 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, ss = s->cur_prompt->prompts[0]->result; } logevent("Sending length-padded password"); - send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, + send_packet(ssh, s->pwpkt_type, PKT_INT, len, PKT_DATA, ss, len, - PKTT_OTHER, PKT_END); + PKT_END); } else { /* * The server is believed unable to cope with @@ -4204,14 +5046,14 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, len = strlen(s->cur_prompt->prompts[0]->result); logevent("Sending unpadded password"); send_packet(ssh, s->pwpkt_type, - PKTT_PASSWORD, PKT_INT, len, + PKT_INT, len, PKT_DATA, s->cur_prompt->prompts[0]->result, len, - PKTT_OTHER, PKT_END); + PKT_END); } } else { - send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD, + send_packet(ssh, s->pwpkt_type, PKT_STR, s->cur_prompt->prompts[0]->result, - PKTT_OTHER, PKT_END); + PKT_END); } logevent("Sent password"); free_prompts(s->cur_prompt); @@ -4261,7 +5103,13 @@ static void ssh_channel_try_eof(struct ssh_channel *c) } } -void sshfwd_write_eof(struct ssh_channel *c) +Conf *sshfwd_get_conf(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + return ssh->conf; +} + +void sshfwd_write_eof(struct ssh_channel *c) { Ssh ssh = c->ssh; @@ -4275,31 +5123,18 @@ void sshfwd_write_eof(struct ssh_channel *c) ssh_channel_try_eof(c); } -void sshfwd_unclean_close(struct ssh_channel *c) +void sshfwd_unclean_close(struct ssh_channel *c, const char *err) { Ssh ssh = c->ssh; - struct Packet *pktout; + char *reason; if (ssh->state == SSH_STATE_CLOSED) return; - if (!(c->closes & CLOSES_SENT_CLOSE)) { - pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); - ssh2_pkt_adduint32(pktout, c->remoteid); - ssh2_pkt_send(ssh, pktout); - c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE; - } - - switch (c->type) { - case CHAN_X11: - x11_close(c->u.x11.s); - break; - case CHAN_SOCKDATA: - case CHAN_SOCKDATA_DORMANT: - pfd_close(c->u.pfd.s); - break; - } - c->type = CHAN_ZOMBIE; + reason = dupprintf("due to local error: %s", err); + ssh_channel_close_local(c, reason); + sfree(reason); + c->pending_eof = FALSE; /* this will confuse a zombie channel */ ssh2_channel_check_close(c); } @@ -4311,43 +5146,17 @@ int sshfwd_write(struct ssh_channel *c, char *buf, int len) if (ssh->state == SSH_STATE_CLOSED) return 0; - if (ssh->version == 1) { - send_packet(ssh, SSH1_MSG_CHANNEL_DATA, - PKT_INT, c->remoteid, - PKT_INT, len, PKTT_DATA, PKT_DATA, buf, len, - PKTT_OTHER, PKT_END); - /* - * In SSH-1 we can return 0 here - implying that forwarded - * connections are never individually throttled - because - * the only circumstance that can cause throttling will be - * the whole SSH connection backing up, in which case - * _everything_ will be throttled as a whole. - */ - return 0; - } else { - ssh2_add_channel_data(c, buf, len); - return ssh2_try_send(c); - } + return ssh_send_channel_data(c, buf, len); } void sshfwd_unthrottle(struct ssh_channel *c, int bufsize) { Ssh ssh = c->ssh; - int buflimit; if (ssh->state == SSH_STATE_CLOSED) return; - if (ssh->version == 1) { - buflimit = SSH1_BUFFER_LIMIT; - } else { - buflimit = c->v.v2.locmaxwin; - ssh2_set_window(c, bufsize < buflimit ? buflimit - bufsize : 0); - } - if (c->throttling_conn && bufsize <= buflimit) { - c->throttling_conn = 0; - ssh_throttle_conn(ssh, -1); - } + ssh_channel_unthrottle(c, bufsize); } static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin) @@ -4435,6 +5244,41 @@ static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx) } } +int ssh_alloc_sharing_rportfwd(Ssh ssh, const char *shost, int sport, + void *share_ctx) +{ + struct ssh_rportfwd *pf = snew(struct ssh_rportfwd); + pf->dhost = NULL; + pf->dport = 0; + pf->share_ctx = share_ctx; + pf->shost = dupstr(shost); + pf->sport = sport; + pf->sportdesc = NULL; + if (!ssh->rportfwds) { + assert(ssh->version == 2); + ssh->rportfwds = newtree234(ssh_rportcmp_ssh2); + } + if (add234(ssh->rportfwds, pf) != pf) { + sfree(pf->shost); + sfree(pf); + return FALSE; + } + return TRUE; +} + +static void ssh_sharing_global_request_response(Ssh ssh, struct Packet *pktin, + void *ctx) +{ + share_got_pkt_from_server(ctx, pktin->type, + pktin->body, pktin->length); +} + +void ssh_sharing_queue_global_request(Ssh ssh, void *share_ctx) +{ + ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, SSH2_MSG_REQUEST_FAILURE, + ssh_sharing_global_request_response, share_ctx); +} + static void ssh_setup_portfwd(Ssh ssh, Conf *conf) { struct ssh_portfwd *epf; @@ -4474,13 +5318,15 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) if (*kp == 'L' || *kp == 'R') type = *kp++; - if ((kp2 = strchr(kp, ':')) != NULL) { + if ((kp2 = host_strchr(kp, ':')) != NULL) { /* * There's a colon in the middle of the source port * string, which means that the part before it is * actually a source address. */ - saddr = dupprintf("%.*s", (int)(kp2 - kp), kp); + char *saddr_tmp = dupprintf("%.*s", (int)(kp2 - kp), kp); + saddr = host_strduptrim(saddr_tmp); + sfree(saddr_tmp); sports = kp2+1; } else { saddr = NULL; @@ -4507,9 +5353,9 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) } else { /* ordinary forwarding */ vp = val; - vp2 = vp + strcspn(vp, ":"); + vp2 = vp + host_strcspn(vp, ":"); host = dupprintf("%.*s", (int)(vp2 - vp), vp); - if (vp2) + if (*vp2) vp2++; dports = vp2; dport = atoi(dports); @@ -4621,9 +5467,9 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) /* XXX: rport_acceptall may not represent * what was used to open the original connection, * since it's reconfigurable. */ - ssh2_pkt_addstring(pktout, "0.0.0.0"); + ssh2_pkt_addstring(pktout, ""); } else { - ssh2_pkt_addstring(pktout, "127.0.0.1"); + ssh2_pkt_addstring(pktout, "localhost"); } ssh2_pkt_adduint32(pktout, epf->sport); ssh2_pkt_send(ssh, pktout); @@ -4632,7 +5478,7 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) del234(ssh->rportfwds, rpf); free_rportfwd(rpf); } else if (epf->local) { - pfd_terminate(epf->local); + pfl_terminate(epf->local); } delpos234(ssh->portfwds, i); @@ -4665,29 +5511,31 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) } if (epf->type == 'L') { - const char *err = pfd_addforward(epf->daddr, epf->dport, - epf->saddr, epf->sport, - ssh, conf, - &epf->local, - epf->addressfamily); + char *err = pfl_listen(epf->daddr, epf->dport, + epf->saddr, epf->sport, + ssh, conf, &epf->local, + epf->addressfamily); logeventf(ssh, "Local %sport %s forwarding to %s%s%s", epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", sportdesc, dportdesc, err ? " failed: " : "", err ? err : ""); + if (err) + sfree(err); } else if (epf->type == 'D') { - const char *err = pfd_addforward(NULL, -1, - epf->saddr, epf->sport, - ssh, conf, - &epf->local, - epf->addressfamily); + char *err = pfl_listen(NULL, -1, epf->saddr, epf->sport, + ssh, conf, &epf->local, + epf->addressfamily); logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s", epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " : epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "", sportdesc, err ? " failed: " : "", err ? err : ""); + + if (err) + sfree(err); } else { struct ssh_rportfwd *pf; @@ -4702,9 +5550,16 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) } pf = snew(struct ssh_rportfwd); - strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1); - pf->dhost[lenof(pf->dhost)-1] = '\0'; + pf->share_ctx = NULL; + pf->dhost = dupstr(epf->daddr); pf->dport = epf->dport; + if (epf->saddr) { + pf->shost = dupstr(epf->saddr); + } else if (conf_get_int(conf, CONF_rport_acceptall)) { + pf->shost = dupstr(""); + } else { + pf->shost = dupstr("localhost"); + } pf->sport = epf->sport; if (add234(ssh->rportfwds, pf) != pf) { logeventf(ssh, "Duplicate remote port forwarding to %s:%d", @@ -4733,14 +5588,8 @@ static void ssh_setup_portfwd(Ssh ssh, Conf *conf) pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST); ssh2_pkt_addstring(pktout, "tcpip-forward"); ssh2_pkt_addbool(pktout, 1);/* want reply */ - if (epf->saddr) { - ssh2_pkt_addstring(pktout, epf->saddr); - } else if (conf_get_int(conf, CONF_rport_acceptall)) { - ssh2_pkt_addstring(pktout, "0.0.0.0"); - } else { - ssh2_pkt_addstring(pktout, "127.0.0.1"); - } - ssh2_pkt_adduint32(pktout, epf->sport); + ssh2_pkt_addstring(pktout, pf->shost); + ssh2_pkt_adduint32(pktout, pf->sport); ssh2_pkt_send(ssh, pktout); ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS, @@ -4790,28 +5639,15 @@ static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin) c = snew(struct ssh_channel); c->ssh = ssh; - if (x11_init(&c->u.x11.s, ssh->x11disp, c, - NULL, -1, ssh->conf) != NULL) { - logevent("Opening X11 forward connection failed"); - sfree(c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, - PKT_INT, remoteid, PKT_END); - } else { - logevent - ("Opening X11 forward connection succeeded"); - c->remoteid = remoteid; - c->halfopen = FALSE; - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->pending_eof = FALSE; - c->throttling_conn = 0; - c->type = CHAN_X11; /* identify channel type */ - add234(ssh->channels, c); - send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, - PKT_INT, c->remoteid, PKT_INT, - c->localid, PKT_END); - logevent("Opened X11 forward channel"); - } + ssh_channel_init(c); + c->u.x11.xconn = x11_init(ssh->x11authtree, c, NULL, -1); + c->remoteid = remoteid; + c->halfopen = FALSE; + c->type = CHAN_X11; /* identify channel type */ + send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, + PKT_INT, c->remoteid, PKT_INT, + c->localid, PKT_END); + logevent("Opened X11 forward channel"); } } @@ -4829,16 +5665,12 @@ static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin) } else { c = snew(struct ssh_channel); c->ssh = ssh; + ssh_channel_init(c); c->remoteid = remoteid; c->halfopen = FALSE; - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->pending_eof = FALSE; - c->throttling_conn = 0; c->type = CHAN_AGENT; /* identify channel type */ - c->u.a.lensofar = 0; - c->u.a.message = NULL; - add234(ssh->channels, c); + c->u.a.pending = NULL; + bufchain_init(&c->u.a.inbuffer); send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, PKT_INT, c->remoteid, PKT_INT, c->localid, PKT_END); @@ -4849,23 +5681,17 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) { /* Remote side is trying to open a channel to talk to a * forwarded port. Give them back a local channel number. */ - struct ssh_channel *c; struct ssh_rportfwd pf, *pfp; int remoteid; int hostsize, port; char *host; - const char *e; - c = snew(struct ssh_channel); - c->ssh = ssh; + char *err; remoteid = ssh_pkt_getuint32(pktin); ssh_pkt_getstring(pktin, &host, &hostsize); port = ssh_pkt_getuint32(pktin); - if (hostsize >= lenof(pf.dhost)) - hostsize = lenof(pf.dhost)-1; - memcpy(pf.dhost, host, hostsize); - pf.dhost[hostsize] = '\0'; + pf.dhost = dupprintf("%.*s", hostsize, NULLTOEMPTY(host)); pf.dport = port; pfp = find234(ssh->rportfwds, &pf, NULL); @@ -4875,45 +5701,44 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin) send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, PKT_INT, remoteid, PKT_END); } else { + struct ssh_channel *c = snew(struct ssh_channel); + c->ssh = ssh; + logeventf(ssh, "Received remote port open request for %s:%d", pf.dhost, port); - e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port, - c, ssh->conf, pfp->pfrec->addressfamily); - if (e != NULL) { - logeventf(ssh, "Port open failed: %s", e); + err = pfd_connect(&c->u.pfd.pf, pf.dhost, port, + c, ssh->conf, pfp->pfrec->addressfamily); + if (err != NULL) { + logeventf(ssh, "Port open failed: %s", err); + sfree(err); sfree(c); send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE, PKT_INT, remoteid, PKT_END); } else { + ssh_channel_init(c); c->remoteid = remoteid; c->halfopen = FALSE; - c->localid = alloc_channel_id(ssh); - c->closes = 0; - c->pending_eof = FALSE; - c->throttling_conn = 0; c->type = CHAN_SOCKDATA; /* identify channel type */ - add234(ssh->channels, c); send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION, PKT_INT, c->remoteid, PKT_INT, c->localid, PKT_END); logevent("Forwarded port opened successfully"); } } + + sfree(pf.dhost); } static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) { - unsigned int remoteid = ssh_pkt_getuint32(pktin); - unsigned int localid = ssh_pkt_getuint32(pktin); struct ssh_channel *c; - c = find234(ssh->channels, &remoteid, ssh_channelfind); - if (c && c->type == CHAN_SOCKDATA_DORMANT) { - c->remoteid = localid; + c = ssh_channel_msg(ssh, pktin); + if (c && c->type == CHAN_SOCKDATA) { + c->remoteid = ssh_pkt_getuint32(pktin); c->halfopen = FALSE; - c->type = CHAN_SOCKDATA; c->throttling_conn = 0; - pfd_confirm(c->u.pfd.s); + pfd_confirm(c->u.pfd.pf); } if (c && c->pending_eof) { @@ -4929,13 +5754,12 @@ static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) { - unsigned int remoteid = ssh_pkt_getuint32(pktin); struct ssh_channel *c; - c = find234(ssh->channels, &remoteid, ssh_channelfind); - if (c && c->type == CHAN_SOCKDATA_DORMANT) { + c = ssh_channel_msg(ssh, pktin); + if (c && c->type == CHAN_SOCKDATA) { logevent("Forwarded connection refused by server"); - pfd_close(c->u.pfd.s); + pfd_close(c->u.pfd.pf); del234(ssh->channels, c); sfree(c); } @@ -4944,52 +5768,26 @@ static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) { /* Remote side closes a channel. */ - unsigned i = ssh_pkt_getuint32(pktin); struct ssh_channel *c; - c = find234(ssh->channels, &i, ssh_channelfind); - if (c && !c->halfopen) { - if (pktin->type == SSH1_MSG_CHANNEL_CLOSE && - !(c->closes & CLOSES_RCVD_EOF)) { + c = ssh_channel_msg(ssh, pktin); + if (c) { + + if (pktin->type == SSH1_MSG_CHANNEL_CLOSE) { /* * Received CHANNEL_CLOSE, which we translate into * outgoing EOF. */ - int send_close = FALSE; - - c->closes |= CLOSES_RCVD_EOF; - - switch (c->type) { - case CHAN_X11: - if (c->u.x11.s) - x11_send_eof(c->u.x11.s); - else - send_close = TRUE; - break; - case CHAN_SOCKDATA: - if (c->u.pfd.s) - pfd_send_eof(c->u.pfd.s); - else - send_close = TRUE; - break; - case CHAN_AGENT: - send_close = TRUE; - break; - } - - if (send_close && !(c->closes & CLOSES_SENT_EOF)) { - send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid, - PKT_END); - c->closes |= CLOSES_SENT_EOF; - } + ssh_channel_got_eof(c); } if (pktin->type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION && !(c->closes & CLOSES_RCVD_CLOSE)) { if (!(c->closes & CLOSES_SENT_EOF)) { - bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %d" - " for which we never sent CHANNEL_CLOSE\n", i)); + bombout(("Received CHANNEL_CLOSE_CONFIRMATION for channel %u" + " for which we never sent CHANNEL_CLOSE\n", + c->localid)); } c->closes |= CLOSES_RCVD_CLOSE; @@ -5004,77 +5802,57 @@ static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin) if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) ssh_channel_destroy(c); - } else { - bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n", - pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" : - "_CONFIRMATION", c ? "half-open" : "nonexistent", - i)); } } +/* + * Handle incoming data on an SSH-1 or SSH-2 agent-forwarding channel. + */ +static int ssh_agent_channel_data(struct ssh_channel *c, char *data, + int length) +{ + bufchain_add(&c->u.a.inbuffer, data, length); + ssh_agentf_try_forward(c); + + /* + * We exert back-pressure on an agent forwarding client if and + * only if we're waiting for the response to an asynchronous agent + * request. This prevents the client running out of window while + * receiving the _first_ message, but means that if any message + * takes time to process, the client will be discouraged from + * sending an endless stream of further ones after it. + */ + return (c->u.a.pending ? bufchain_size(&c->u.a.inbuffer) : 0); +} + +static int ssh_channel_data(struct ssh_channel *c, int is_stderr, + char *data, int length) +{ + switch (c->type) { + case CHAN_MAINSESSION: + return from_backend(c->ssh->frontend, is_stderr, data, length); + case CHAN_X11: + return x11_send(c->u.x11.xconn, data, length); + case CHAN_SOCKDATA: + return pfd_send(c->u.pfd.pf, data, length); + case CHAN_AGENT: + return ssh_agent_channel_data(c, data, length); + } + return 0; +} + static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin) { /* Data sent down one of our channels. */ - int i = ssh_pkt_getuint32(pktin); char *p; int len; struct ssh_channel *c; + c = ssh_channel_msg(ssh, pktin); ssh_pkt_getstring(pktin, &p, &len); - c = find234(ssh->channels, &i, ssh_channelfind); if (c) { - int bufsize = 0; - switch (c->type) { - case CHAN_X11: - bufsize = x11_send(c->u.x11.s, p, len); - break; - case CHAN_SOCKDATA: - bufsize = pfd_send(c->u.pfd.s, p, len); - break; - case CHAN_AGENT: - /* Data for an agent message. Buffer it. */ - while (len > 0) { - if (c->u.a.lensofar < 4) { - unsigned int l = min(4 - c->u.a.lensofar, (unsigned)len); - memcpy(c->u.a.msglen + c->u.a.lensofar, p, - l); - p += l; - len -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == 4) { - c->u.a.totallen = - 4 + GET_32BIT(c->u.a.msglen); - c->u.a.message = snewn(c->u.a.totallen, - unsigned char); - memcpy(c->u.a.message, c->u.a.msglen, 4); - } - if (c->u.a.lensofar >= 4 && len > 0) { - unsigned int l = - min(c->u.a.totallen - c->u.a.lensofar, - (unsigned)len); - memcpy(c->u.a.message + c->u.a.lensofar, p, - l); - p += l; - len -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == c->u.a.totallen) { - void *reply; - int replylen; - if (agent_query(c->u.a.message, - c->u.a.totallen, - &reply, &replylen, - ssh_agentf_callback, c)) - ssh_agentf_callback(c, reply, replylen); - sfree(c->u.a.message); - c->u.a.lensofar = 0; - } - } - bufsize = 0; /* agent channels never back up */ - break; - } + int bufsize = ssh_channel_data(c, FALSE, p, len); if (!c->throttling_conn && bufsize > SSH1_BUFFER_LIMIT) { c->throttling_conn = 1; ssh_throttle_conn(ssh, +1); @@ -5098,14 +5876,13 @@ static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin) } /* Helper function to deal with sending tty modes for REQUEST_PTY */ -static void ssh1_send_ttymode(void *data, char *mode, char *val) +static void ssh1_send_ttymode(void *data, + const struct ssh_ttymode *mode, char *val) { struct Packet *pktout = (struct Packet *)data; - int i = 0; unsigned int arg = 0; - while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; - if (i == lenof(ssh_ttymodes)) return; - switch (ssh_ttymodes[i].type) { + + switch (mode->type) { case TTY_OP_CHAR: arg = ssh_tty_parse_specchar(val); break; @@ -5113,12 +5890,16 @@ static void ssh1_send_ttymode(void *data, char *mode, char *val) arg = ssh_tty_parse_boolean(val); break; } - ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); + ssh2_pkt_addbyte(pktout, mode->opcode); ssh2_pkt_addbyte(pktout, arg); } +int ssh_agent_forwarding_permitted(Ssh ssh) +{ + return conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists(); +} -static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, +static void do_ssh1_connection(Ssh ssh, const unsigned char *in, int inlen, struct Packet *pktin) { crBegin(ssh->do_ssh1_connection_crstate); @@ -5137,7 +5918,7 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data; ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status; - if (conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) { + if (ssh_agent_forwarding_permitted(ssh)) { logevent("Requesting agent forwarding"); send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END); do { @@ -5156,47 +5937,47 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, } } - if (conf_get_int(ssh->conf, CONF_x11_forward) && - (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), - conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) { - logevent("Requesting X11 forwarding"); - /* - * Note that while we blank the X authentication data here, we don't - * take any special action to blank the start of an X11 channel, - * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection - * without having session blanking enabled is likely to leak your - * cookie into the log. - */ - if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { - send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, - PKT_STR, ssh->x11disp->remoteauthprotoname, - PKTT_PASSWORD, - PKT_STR, ssh->x11disp->remoteauthdatastring, - PKTT_OTHER, - PKT_INT, ssh->x11disp->screennum, - PKT_END); - } else { - send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, - PKT_STR, ssh->x11disp->remoteauthprotoname, - PKTT_PASSWORD, - PKT_STR, ssh->x11disp->remoteauthdatastring, - PKTT_OTHER, - PKT_END); - } - do { - crReturnV; - } while (!pktin); - if (pktin->type != SSH1_SMSG_SUCCESS - && pktin->type != SSH1_SMSG_FAILURE) { - bombout(("Protocol confusion")); - crStopV; - } else if (pktin->type == SSH1_SMSG_FAILURE) { - logevent("X11 forwarding refused"); - } else { - logevent("X11 forwarding enabled"); - ssh->X11_fwd_enabled = TRUE; - ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open; - } + if (conf_get_int(ssh->conf, CONF_x11_forward)) { + ssh->x11disp = + x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), + ssh->conf); + if (!ssh->x11disp) { + /* FIXME: return an error message from x11_setup_display */ + logevent("X11 forwarding not enabled: unable to" + " initialise X display"); + } else { + ssh->x11auth = x11_invent_fake_auth + (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth)); + ssh->x11auth->disp = ssh->x11disp; + + logevent("Requesting X11 forwarding"); + if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, ssh->x11auth->protoname, + PKT_STR, ssh->x11auth->datastring, + PKT_INT, ssh->x11disp->screennum, + PKT_END); + } else { + send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING, + PKT_STR, ssh->x11auth->protoname, + PKT_STR, ssh->x11auth->datastring, + PKT_END); + } + do { + crReturnV; + } while (!pktin); + if (pktin->type != SSH1_SMSG_SUCCESS + && pktin->type != SSH1_SMSG_FAILURE) { + bombout(("Protocol confusion")); + crStopV; + } else if (pktin->type == SSH1_SMSG_FAILURE) { + logevent("X11 forwarding refused"); + } else { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open; + } + } } ssh_setup_portfwd(ssh, ssh->conf); @@ -5291,7 +6072,7 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, ssh_special(ssh, TS_EOF); if (ssh->ldisc) - ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ + ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */ ssh->send_ok = 1; ssh->channels = newtree234(ssh_channelcmp); while (1) { @@ -5317,8 +6098,8 @@ static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen, while (inlen > 0) { int len = min(inlen, 512); send_packet(ssh, SSH1_CMSG_STDIN_DATA, - PKT_INT, len, PKTT_DATA, PKT_DATA, in, len, - PKTT_OTHER, PKT_END); + PKT_INT, len, PKT_DATA, in, len, + PKT_END); in += len; inlen -= len; } @@ -5337,7 +6118,7 @@ static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin) int msglen; ssh_pkt_getstring(pktin, &msg, &msglen); - logeventf(ssh, "Remote debug message: %.*s", msglen, msg); + logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg)); } static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) @@ -5347,7 +6128,8 @@ static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin) int msglen; ssh_pkt_getstring(pktin, &msg, &msglen); - bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg)); + bombout(("Server sent disconnect message:\n\"%.*s\"", + msglen, NULLTOEMPTY(msg))); } static void ssh_msg_ignore(Ssh ssh, struct Packet *pktin) @@ -5373,10 +6155,10 @@ static void ssh1_protocol_setup(Ssh ssh) ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug; } -static void ssh1_protocol(Ssh ssh, void *vin, int inlen, +static void ssh1_protocol(Ssh ssh, const void *vin, int inlen, struct Packet *pktin) { - unsigned char *in=(unsigned char*)vin; + const unsigned char *in = (const unsigned char *)vin; if (ssh->state == SSH_STATE_CLOSED) return; @@ -5396,69 +6178,77 @@ static void ssh1_protocol(Ssh ssh, void *vin, int inlen, } /* - * Utility routine for decoding comma-separated strings in KEXINIT. + * Utility routines for decoding comma-separated strings in KEXINIT. */ -static int in_commasep_string(char *needle, char *haystack, int haylen) +static int first_in_commasep_string(char const *needle, char const *haystack, + int haylen) { int needlen; if (!needle || !haystack) /* protect against null pointers */ return 0; needlen = strlen(needle); - while (1) { - /* - * Is it at the start of the string? - */ - if (haylen >= needlen && /* haystack is long enough */ - !memcmp(needle, haystack, needlen) && /* initial match */ - (haylen == needlen || haystack[needlen] == ',') - /* either , or EOS follows */ - ) - return 1; - /* - * If not, search for the next comma and resume after that. - * If no comma found, terminate. - */ - while (haylen > 0 && *haystack != ',') - haylen--, haystack++; - if (haylen == 0) - return 0; - haylen--, haystack++; /* skip over comma itself */ - } + + if (haylen >= needlen && /* haystack is long enough */ + !memcmp(needle, haystack, needlen) && /* initial match */ + (haylen == needlen || haystack[needlen] == ',') + /* either , or EOS follows */ + ) + return 1; + return 0; } -/* - * Similar routine for checking whether we have the first string in a list. - */ -static int first_in_commasep_string(char *needle, char *haystack, int haylen) +static int in_commasep_string(char const *needle, char const *haystack, + int haylen) { - int needlen; + char *p; + if (!needle || !haystack) /* protect against null pointers */ return 0; - needlen = strlen(needle); /* * Is it at the start of the string? */ - if (haylen >= needlen && /* haystack is long enough */ - !memcmp(needle, haystack, needlen) && /* initial match */ - (haylen == needlen || haystack[needlen] == ',') - /* either , or EOS follows */ - ) + if (first_in_commasep_string(needle, haystack, haylen)) return 1; - return 0; + /* + * If not, search for the next comma and resume after that. + * If no comma found, terminate. + */ + p = memchr(haystack, ',', haylen); + if (!p) return 0; + /* + 1 to skip over comma */ + return in_commasep_string(needle, p + 1, haylen - (p + 1 - haystack)); +} + +/* + * Add a value to the comma-separated string at the end of the packet. + */ +static void ssh2_pkt_addstring_commasep(struct Packet *pkt, const char *data) +{ + if (pkt->length - pkt->savedpos > 0) + ssh_pkt_addstring_str(pkt, ","); + ssh_pkt_addstring_str(pkt, data); } /* - * SSH-2 key creation method. - * (Currently assumes 2 lots of any hash are sufficient to generate - * keys/IVs for any cipher/MAC. SSH2_MKKEY_ITERS documents this assumption.) + * SSH-2 key derivation (RFC 4253 section 7.2). */ -#define SSH2_MKKEY_ITERS (2) -static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, - unsigned char *keyspace) +static unsigned char *ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, + char chr, int keylen) { const struct ssh_hash *h = ssh->kex->hash; - void *s; + int keylen_padded; + unsigned char *key; + void *s, *s2; + + if (keylen == 0) + return NULL; + + /* Round up to the next multiple of hash length. */ + keylen_padded = ((keylen + h->hlen - 1) / h->hlen) * h->hlen; + + key = snewn(keylen_padded, unsigned char); + /* First hlen bytes. */ s = h->init(); if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) @@ -5466,45 +6256,128 @@ static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H, char chr, h->bytes(s, H, h->hlen); h->bytes(s, &chr, 1); h->bytes(s, ssh->v2_session_id, ssh->v2_session_id_len); - h->final(s, keyspace); - /* Next hlen bytes. */ - s = h->init(); - if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) - hash_mpint(h, s, K); - h->bytes(s, H, h->hlen); - h->bytes(s, keyspace, h->hlen); - h->final(s, keyspace + h->hlen); + h->final(s, key); + + /* Subsequent blocks of hlen bytes. */ + if (keylen_padded > h->hlen) { + int offset; + + s = h->init(); + if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY)) + hash_mpint(h, s, K); + h->bytes(s, H, h->hlen); + + for (offset = h->hlen; offset < keylen_padded; offset += h->hlen) { + h->bytes(s, key + offset - h->hlen, h->hlen); + s2 = h->copy(s); + h->final(s2, key + offset); + } + + h->free(s); + } + + /* Now clear any extra bytes of key material beyond the length + * we're officially returning, because the caller won't know to + * smemclr those. */ + if (keylen_padded > keylen) + smemclr(key + keylen, keylen_padded - keylen); + + return key; +} + +/* + * Structure for constructing KEXINIT algorithm lists. + */ +#define MAXKEXLIST 16 +struct kexinit_algorithm { + const char *name; + union { + struct { + const struct ssh_kex *kex; + int warn; + } kex; + struct { + const struct ssh_signkey *hostkey; + int warn; + } hk; + struct { + const struct ssh2_cipher *cipher; + int warn; + } cipher; + struct { + const struct ssh_mac *mac; + int etm; + } mac; + const struct ssh_compress *comp; + } u; +}; + +/* + * Find a slot in a KEXINIT algorithm list to use for a new algorithm. + * If the algorithm is already in the list, return a pointer to its + * entry, otherwise return an entry from the end of the list. + * This assumes that every time a particular name is passed in, it + * comes from the same string constant. If this isn't true, this + * function may need to be rewritten to use strcmp() instead. + */ +static struct kexinit_algorithm *ssh2_kexinit_addalg(struct kexinit_algorithm + *list, const char *name) +{ + int i; + + for (i = 0; i < MAXKEXLIST; i++) + if (list[i].name == NULL || list[i].name == name) { + list[i].name = name; + return &list[i]; + } + assert(!"No space in KEXINIT list"); + return NULL; } /* * Handle the SSH-2 transport layer. */ -static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, +static void do_ssh2_transport(Ssh ssh, const void *vin, int inlen, struct Packet *pktin) { - unsigned char *in = (unsigned char *)vin; + const unsigned char *in = (const unsigned char *)vin; + enum kexlist { + KEXLIST_KEX, KEXLIST_HOSTKEY, KEXLIST_CSCIPHER, KEXLIST_SCCIPHER, + KEXLIST_CSMAC, KEXLIST_SCMAC, KEXLIST_CSCOMP, KEXLIST_SCCOMP, + NKEXLIST + }; + const char * kexlist_descr[NKEXLIST] = { + "key exchange algorithm", "host key algorithm", + "client-to-server cipher", "server-to-client cipher", + "client-to-server MAC", "server-to-client MAC", + "client-to-server compression method", + "server-to-client compression method" }; struct do_ssh2_transport_state { int crLine; - int nbits, pbits, warn_kex, warn_cscipher, warn_sccipher; + int nbits, pbits, warn_kex, warn_hk, warn_cscipher, warn_sccipher; Bignum p, g, e, f, K; void *our_kexinit; int our_kexinitlen; int kex_init_value, kex_reply_value; - const struct ssh_mac **maclist; + const struct ssh_mac *const *maclist; int nmacs; const struct ssh2_cipher *cscipher_tobe; const struct ssh2_cipher *sccipher_tobe; const struct ssh_mac *csmac_tobe; const struct ssh_mac *scmac_tobe; + int csmac_etm_tobe, scmac_etm_tobe; const struct ssh_compress *cscomp_tobe; const struct ssh_compress *sccomp_tobe; char *hostkeydata, *sigdata, *rsakeydata, *keystr, *fingerprint; int hostkeylen, siglen, rsakeylen; void *hkey; /* actual host key */ void *rsakey; /* for RSA kex */ + void *eckey; /* for ECDH kex */ unsigned char exchange_hash[SSH2_KEX_MAX_HASH_LEN]; int n_preferred_kex; const struct ssh_kexes *preferred_kex[KEX_MAX]; + int n_preferred_hk; + int preferred_hk[HK_MAX]; int n_preferred_ciphers; const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX]; const struct ssh_compress *preferred_comp; @@ -5515,9 +6388,13 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, int dlgret; int guessok; int ignorepkt; + struct kexinit_algorithm kexlists[NKEXLIST][MAXKEXLIST]; }; crState(do_ssh2_transport_state); + assert(!ssh->bare_connection); + assert(ssh->version == 2); + crBeginState; s->cscipher_tobe = s->sccipher_tobe = NULL; @@ -5539,7 +6416,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, begin_key_exchange: ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; { - int i, j, k, commalist_started; + int i, j, k, warn; + struct kexinit_algorithm *alg; /* * Set up the preferred key exchange. (NULL => warn below here) @@ -5563,6 +6441,10 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, s->preferred_kex[s->n_preferred_kex++] = &ssh_rsa_kex; break; + case KEX_ECDH: + s->preferred_kex[s->n_preferred_kex++] = + &ssh_ecdh_kex; + break; case KEX_WARN: /* Flag for later. Don't bother if it's the last in * the list. */ @@ -5573,6 +6455,20 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } } + /* + * Set up the preferred host key types. These are just the ids + * in the enum in putty.h, so 'warn below here' is indicated + * by HK_WARN. + */ + s->n_preferred_hk = 0; + for (i = 0; i < HK_MAX; i++) { + int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, i); + /* As above, don't bother with HK_WARN if it's last in the + * list */ + if (id != HK_WARN || i < HK_MAX - 1) + s->preferred_hk[s->n_preferred_hk++] = id; + } + /* * Set up the preferred ciphers. (NULL => warn below here) */ @@ -5596,6 +6492,9 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, case CIPHER_ARCFOUR: s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_arcfour; break; + case CIPHER_CHACHA20: + s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_ccp; + break; case CIPHER_WARN: /* Flag for later. Don't bother if it's the last in * the list. */ @@ -5625,84 +6524,158 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, */ ssh->kex_in_progress = TRUE; - /* - * Construct and send our key exchange packet. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); - for (i = 0; i < 16; i++) - ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); + for (i = 0; i < NKEXLIST; i++) + for (j = 0; j < MAXKEXLIST; j++) + s->kexlists[i][j].name = NULL; /* List key exchange algorithms. */ - ssh2_pkt_addstring_start(s->pktout); - commalist_started = 0; + warn = FALSE; for (i = 0; i < s->n_preferred_kex; i++) { const struct ssh_kexes *k = s->preferred_kex[i]; - if (!k) continue; /* warning flag */ - for (j = 0; j < k->nkexes; j++) { - if (commalist_started) - ssh2_pkt_addstring_str(s->pktout, ","); - ssh2_pkt_addstring_str(s->pktout, k->list[j]->name); - commalist_started = 1; + if (!k) warn = TRUE; + else for (j = 0; j < k->nkexes; j++) { + alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_KEX], + k->list[j]->name); + alg->u.kex.kex = k->list[j]; + alg->u.kex.warn = warn; } } /* List server host key algorithms. */ - ssh2_pkt_addstring_start(s->pktout); - for (i = 0; i < lenof(hostkey_algs); i++) { - ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name); - if (i < lenof(hostkey_algs) - 1) - ssh2_pkt_addstring_str(s->pktout, ","); - } + if (!s->got_session_id) { + /* + * In the first key exchange, we list all the algorithms + * we're prepared to cope with, but prefer those algorithms + * for which we have a host key for this host. + * + * If the host key algorithm is below the warning + * threshold, we warn even if we did already have a key + * for it, on the basis that if the user has just + * reconfigured that host key type to be warned about, + * they surely _do_ want to be alerted that a server + * they're actually connecting to is using it. + */ + warn = FALSE; + for (i = 0; i < s->n_preferred_hk; i++) { + if (s->preferred_hk[i] == HK_WARN) + warn = TRUE; + for (j = 0; j < lenof(hostkey_algs); j++) { + if (hostkey_algs[j].id != s->preferred_hk[i]) + continue; + if (have_ssh_host_key(ssh->savedhost, ssh->savedport, + hostkey_algs[j].alg->keytype)) { + alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY], + hostkey_algs[j].alg->name); + alg->u.hk.hostkey = hostkey_algs[j].alg; + alg->u.hk.warn = warn; + } + } + } + warn = FALSE; + for (i = 0; i < s->n_preferred_hk; i++) { + if (s->preferred_hk[i] == HK_WARN) + warn = TRUE; + for (j = 0; j < lenof(hostkey_algs); j++) { + if (hostkey_algs[j].id != s->preferred_hk[i]) + continue; + alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY], + hostkey_algs[j].alg->name); + alg->u.hk.hostkey = hostkey_algs[j].alg; + alg->u.hk.warn = warn; + } + } + } else { + /* + * In subsequent key exchanges, we list only the kex + * algorithm that was selected in the first key exchange, + * so that we keep getting the same host key and hence + * don't have to interrupt the user's session to ask for + * reverification. + */ + assert(ssh->kex); + alg = ssh2_kexinit_addalg(s->kexlists[KEXLIST_HOSTKEY], + ssh->hostkey->name); + alg->u.hk.hostkey = ssh->hostkey; + alg->u.hk.warn = FALSE; + } /* List encryption algorithms (client->server then server->client). */ - for (k = 0; k < 2; k++) { - ssh2_pkt_addstring_start(s->pktout); - commalist_started = 0; + for (k = KEXLIST_CSCIPHER; k <= KEXLIST_SCCIPHER; k++) { + warn = FALSE; +#ifdef FUZZING + alg = ssh2_kexinit_addalg(s->kexlists[k], "none"); + alg->u.cipher.cipher = NULL; + alg->u.cipher.warn = warn; +#endif /* FUZZING */ for (i = 0; i < s->n_preferred_ciphers; i++) { const struct ssh2_ciphers *c = s->preferred_ciphers[i]; - if (!c) continue; /* warning flag */ - for (j = 0; j < c->nciphers; j++) { - if (commalist_started) - ssh2_pkt_addstring_str(s->pktout, ","); - ssh2_pkt_addstring_str(s->pktout, c->list[j]->name); - commalist_started = 1; + if (!c) warn = TRUE; + else for (j = 0; j < c->nciphers; j++) { + alg = ssh2_kexinit_addalg(s->kexlists[k], + c->list[j]->name); + alg->u.cipher.cipher = c->list[j]; + alg->u.cipher.warn = warn; } } } /* List MAC algorithms (client->server then server->client). */ - for (j = 0; j < 2; j++) { - ssh2_pkt_addstring_start(s->pktout); + for (j = KEXLIST_CSMAC; j <= KEXLIST_SCMAC; j++) { +#ifdef FUZZING + alg = ssh2_kexinit_addalg(s->kexlists[j], "none"); + alg->u.mac.mac = NULL; + alg->u.mac.etm = FALSE; +#endif /* FUZZING */ for (i = 0; i < s->nmacs; i++) { - ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name); - if (i < s->nmacs - 1) - ssh2_pkt_addstring_str(s->pktout, ","); - } + alg = ssh2_kexinit_addalg(s->kexlists[j], s->maclist[i]->name); + alg->u.mac.mac = s->maclist[i]; + alg->u.mac.etm = FALSE; + } + for (i = 0; i < s->nmacs; i++) + /* For each MAC, there may also be an ETM version, + * which we list second. */ + if (s->maclist[i]->etm_name) { + alg = ssh2_kexinit_addalg(s->kexlists[j], + s->maclist[i]->etm_name); + alg->u.mac.mac = s->maclist[i]; + alg->u.mac.etm = TRUE; + } } /* List client->server compression algorithms, * then server->client compression algorithms. (We use the * same set twice.) */ - for (j = 0; j < 2; j++) { - ssh2_pkt_addstring_start(s->pktout); + for (j = KEXLIST_CSCOMP; j <= KEXLIST_SCCOMP; j++) { assert(lenof(compressions) > 1); /* Prefer non-delayed versions */ - ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name); + alg = ssh2_kexinit_addalg(s->kexlists[j], s->preferred_comp->name); + alg->u.comp = s->preferred_comp; /* We don't even list delayed versions of algorithms until * they're allowed to be used, to avoid a race. See the end of * this function. */ if (s->userauth_succeeded && s->preferred_comp->delayed_name) { - ssh2_pkt_addstring_str(s->pktout, ","); - ssh2_pkt_addstring_str(s->pktout, - s->preferred_comp->delayed_name); + alg = ssh2_kexinit_addalg(s->kexlists[j], + s->preferred_comp->delayed_name); + alg->u.comp = s->preferred_comp; } for (i = 0; i < lenof(compressions); i++) { const struct ssh_compress *c = compressions[i]; - if (c != s->preferred_comp) { - ssh2_pkt_addstring_str(s->pktout, ","); - ssh2_pkt_addstring_str(s->pktout, c->name); - if (s->userauth_succeeded && c->delayed_name) { - ssh2_pkt_addstring_str(s->pktout, ","); - ssh2_pkt_addstring_str(s->pktout, c->delayed_name); - } + alg = ssh2_kexinit_addalg(s->kexlists[j], c->name); + alg->u.comp = c; + if (s->userauth_succeeded && c->delayed_name) { + alg = ssh2_kexinit_addalg(s->kexlists[j], c->delayed_name); + alg->u.comp = c; } } } + /* + * Construct and send our key exchange packet. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT); + for (i = 0; i < 16; i++) + ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte()); + for (i = 0; i < NKEXLIST; i++) { + ssh2_pkt_addstring_start(s->pktout); + for (j = 0; j < MAXKEXLIST; j++) { + if (s->kexlists[i][j].name == NULL) break; + ssh2_pkt_addstring_commasep(s->pktout, s->kexlists[i][j].name); + } + } /* List client->server languages. Empty list. */ ssh2_pkt_addstring_start(s->pktout); /* List server->client languages. Empty list. */ @@ -5720,19 +6693,19 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh2_pkt_send_noqueue(ssh, s->pktout); if (!pktin) - crWaitUntil(pktin); + crWaitUntilV(pktin); /* * Now examine the other side's KEXINIT to see what we're up * to. */ { - char *str, *preferred; + char *str; int i, j, len; if (pktin->type != SSH2_MSG_KEXINIT) { bombout(("expected key exchange packet from server")); - crStop(0); + crStopV; } ssh->kex = NULL; ssh->hostkey = NULL; @@ -5742,144 +6715,109 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, s->scmac_tobe = NULL; s->cscomp_tobe = NULL; s->sccomp_tobe = NULL; - s->warn_kex = s->warn_cscipher = s->warn_sccipher = FALSE; + s->warn_kex = s->warn_hk = FALSE; + s->warn_cscipher = s->warn_sccipher = FALSE; pktin->savedpos += 16; /* skip garbage cookie */ - ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */ - preferred = NULL; - for (i = 0; i < s->n_preferred_kex; i++) { - const struct ssh_kexes *k = s->preferred_kex[i]; - if (!k) { - s->warn_kex = TRUE; - } else { - for (j = 0; j < k->nkexes; j++) { - if (!preferred) preferred = k->list[j]->name; - if (in_commasep_string(k->list[j]->name, str, len)) { - ssh->kex = k->list[j]; - break; - } - } + s->guessok = FALSE; + for (i = 0; i < NKEXLIST; i++) { + ssh_pkt_getstring(pktin, &str, &len); + if (!str) { + bombout(("KEXINIT packet was incomplete")); + crStopV; } - if (ssh->kex) - break; - } - if (!ssh->kex) { - bombout(("Couldn't agree a key exchange algorithm (available: %s)", - str ? str : "(null)")); - crStop(0); - } - /* - * Note that the server's guess is considered wrong if it doesn't match - * the first algorithm in our list, even if it's still the algorithm - * we end up using. - */ - s->guessok = first_in_commasep_string(preferred, str, len); - ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */ - for (i = 0; i < lenof(hostkey_algs); i++) { - if (in_commasep_string(hostkey_algs[i]->name, str, len)) { - ssh->hostkey = hostkey_algs[i]; - break; - } - } - if (!ssh->hostkey) { - bombout(("Couldn't agree a host key algorithm (available: %s)", - str ? str : "(null)")); - crStop(0); - } - s->guessok = s->guessok && - first_in_commasep_string(hostkey_algs[0]->name, str, len); - ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */ - for (i = 0; i < s->n_preferred_ciphers; i++) { - const struct ssh2_ciphers *c = s->preferred_ciphers[i]; - if (!c) { - s->warn_cscipher = TRUE; - } else { - for (j = 0; j < c->nciphers; j++) { - if (in_commasep_string(c->list[j]->name, str, len)) { - s->cscipher_tobe = c->list[j]; - break; - } - } - } - if (s->cscipher_tobe) - break; - } - if (!s->cscipher_tobe) { - bombout(("Couldn't agree a client-to-server cipher (available: %s)", - str ? str : "(null)")); - crStop(0); - } + /* If we've already selected a cipher which requires a + * particular MAC, then just select that, and don't even + * bother looking through the server's KEXINIT string for + * MACs. */ + if (i == KEXLIST_CSMAC && s->cscipher_tobe && + s->cscipher_tobe->required_mac) { + s->csmac_tobe = s->cscipher_tobe->required_mac; + s->csmac_etm_tobe = !!(s->csmac_tobe->etm_name); + goto matched; + } + if (i == KEXLIST_SCMAC && s->sccipher_tobe && + s->sccipher_tobe->required_mac) { + s->scmac_tobe = s->sccipher_tobe->required_mac; + s->scmac_etm_tobe = !!(s->scmac_tobe->etm_name); + goto matched; + } - ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */ - for (i = 0; i < s->n_preferred_ciphers; i++) { - const struct ssh2_ciphers *c = s->preferred_ciphers[i]; - if (!c) { - s->warn_sccipher = TRUE; - } else { - for (j = 0; j < c->nciphers; j++) { - if (in_commasep_string(c->list[j]->name, str, len)) { - s->sccipher_tobe = c->list[j]; - break; + for (j = 0; j < MAXKEXLIST; j++) { + struct kexinit_algorithm *alg = &s->kexlists[i][j]; + if (alg->name == NULL) break; + if (in_commasep_string(alg->name, str, len)) { + /* We've found a matching algorithm. */ + if (i == KEXLIST_KEX || i == KEXLIST_HOSTKEY) { + /* Check if we might need to ignore first kex pkt */ + if (j != 0 || + !first_in_commasep_string(alg->name, str, len)) + s->guessok = FALSE; } + if (i == KEXLIST_KEX) { + ssh->kex = alg->u.kex.kex; + s->warn_kex = alg->u.kex.warn; + } else if (i == KEXLIST_HOSTKEY) { + ssh->hostkey = alg->u.hk.hostkey; + s->warn_hk = alg->u.hk.warn; + } else if (i == KEXLIST_CSCIPHER) { + s->cscipher_tobe = alg->u.cipher.cipher; + s->warn_cscipher = alg->u.cipher.warn; + } else if (i == KEXLIST_SCCIPHER) { + s->sccipher_tobe = alg->u.cipher.cipher; + s->warn_sccipher = alg->u.cipher.warn; + } else if (i == KEXLIST_CSMAC) { + s->csmac_tobe = alg->u.mac.mac; + s->csmac_etm_tobe = alg->u.mac.etm; + } else if (i == KEXLIST_SCMAC) { + s->scmac_tobe = alg->u.mac.mac; + s->scmac_etm_tobe = alg->u.mac.etm; + } else if (i == KEXLIST_CSCOMP) { + s->cscomp_tobe = alg->u.comp; + } else if (i == KEXLIST_SCCOMP) { + s->sccomp_tobe = alg->u.comp; + } + goto matched; } - } - if (s->sccipher_tobe) - break; - } - if (!s->sccipher_tobe) { - bombout(("Couldn't agree a server-to-client cipher (available: %s)", - str ? str : "(null)")); - crStop(0); - } - - ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */ - for (i = 0; i < s->nmacs; i++) { - if (in_commasep_string(s->maclist[i]->name, str, len)) { - s->csmac_tobe = s->maclist[i]; - break; - } - } - ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */ - for (i = 0; i < s->nmacs; i++) { - if (in_commasep_string(s->maclist[i]->name, str, len)) { - s->scmac_tobe = s->maclist[i]; - break; - } - } - ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */ - for (i = 0; i < lenof(compressions) + 1; i++) { - const struct ssh_compress *c = - i == 0 ? s->preferred_comp : compressions[i - 1]; - if (in_commasep_string(c->name, str, len)) { - s->cscomp_tobe = c; - break; - } else if (in_commasep_string(c->delayed_name, str, len)) { - if (s->userauth_succeeded) { - s->cscomp_tobe = c; - break; - } else { - s->pending_compression = TRUE; /* try this later */ - } - } - } - ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */ - for (i = 0; i < lenof(compressions) + 1; i++) { - const struct ssh_compress *c = - i == 0 ? s->preferred_comp : compressions[i - 1]; - if (in_commasep_string(c->name, str, len)) { - s->sccomp_tobe = c; - break; - } else if (in_commasep_string(c->delayed_name, str, len)) { - if (s->userauth_succeeded) { - s->sccomp_tobe = c; - break; - } else { + if ((i == KEXLIST_CSCOMP || i == KEXLIST_SCCOMP) && + in_commasep_string(alg->u.comp->delayed_name, str, len)) s->pending_compression = TRUE; /* try this later */ - } } + bombout(("Couldn't agree a %s (available: %.*s)", + kexlist_descr[i], len, str)); + crStopV; + matched:; + + if (i == KEXLIST_HOSTKEY) { + int j; + + /* + * In addition to deciding which host key we're + * actually going to use, we should make a list of the + * host keys offered by the server which we _don't_ + * have cached. These will be offered as cross- + * certification options by ssh_get_specials. + * + * We also count the key we're currently using for KEX + * as one we've already got, because by the time this + * menu becomes visible, it will be. + */ + ssh->n_uncert_hostkeys = 0; + + for (j = 0; j < lenof(hostkey_algs); j++) { + if (hostkey_algs[j].alg != ssh->hostkey && + in_commasep_string(hostkey_algs[j].alg->name, + str, len) && + !have_ssh_host_key(ssh->savedhost, ssh->savedport, + hostkey_algs[j].alg->keytype)) { + ssh->uncert_hostkeys[ssh->n_uncert_hostkeys++] = j; + } + } + } } + if (s->pending_compression) { logevent("Server supports delayed compression; " "will try this later"); @@ -5888,6 +6826,16 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh_pkt_getstring(pktin, &str, &len); /* server->client language */ s->ignorepkt = ssh2_pkt_getbool(pktin) && !s->guessok; + ssh->exhash = ssh->kex->hash->init(); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); + hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); + hash_string(ssh->kex->hash, ssh->exhash, + s->our_kexinit, s->our_kexinitlen); + sfree(s->our_kexinit); + /* Include the type byte in the hash of server's KEXINIT */ + hash_string(ssh->kex->hash, ssh->exhash, + pktin->body - 1, pktin->length + 1); + if (s->warn_kex) { ssh_set_frozen(ssh, 1); s->dlgret = askalg(ssh->frontend, "key-exchange algorithm", @@ -5895,11 +6843,11 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh_dialog_callback, ssh); if (s->dlgret < 0) { do { - crReturn(0); + crReturnV; if (pktin) { bombout(("Unexpected data from server while" " waiting for user response")); - crStop(0); + crStopV; } } while (pktin || inlen > 0); s->dlgret = ssh->user_response; @@ -5908,7 +6856,74 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, if (s->dlgret == 0) { ssh_disconnect(ssh, "User aborted at kex warning", NULL, 0, TRUE); - crStop(0); + crStopV; + } + } + + if (s->warn_hk) { + int j, k; + char *betteralgs; + + ssh_set_frozen(ssh, 1); + + /* + * Change warning box wording depending on why we chose a + * warning-level host key algorithm. If it's because + * that's all we have *cached*, use the askhk mechanism, + * and list the host keys we could usefully cross-certify. + * Otherwise, use askalg for the standard wording. + */ + betteralgs = NULL; + for (j = 0; j < ssh->n_uncert_hostkeys; j++) { + const struct ssh_signkey_with_user_pref_id *hktype = + &hostkey_algs[ssh->uncert_hostkeys[j]]; + int better = FALSE; + for (k = 0; k < HK_MAX; k++) { + int id = conf_get_int_int(ssh->conf, CONF_ssh_hklist, k); + if (id == HK_WARN) { + break; + } else if (id == hktype->id) { + better = TRUE; + break; + } + } + if (better) { + if (betteralgs) { + char *old_ba = betteralgs; + betteralgs = dupcat(betteralgs, ",", + hktype->alg->name, + (const char *)NULL); + sfree(old_ba); + } else { + betteralgs = dupstr(hktype->alg->name); + } + } + } + if (betteralgs) { + s->dlgret = askhk(ssh->frontend, ssh->hostkey->name, + betteralgs, ssh_dialog_callback, ssh); + sfree(betteralgs); + } else { + s->dlgret = askalg(ssh->frontend, "host key type", + ssh->hostkey->name, + ssh_dialog_callback, ssh); + } + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while" + " waiting for user response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; + } + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "User aborted at host key warning", NULL, + 0, TRUE); + crStopV; } } @@ -5920,11 +6935,11 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh_dialog_callback, ssh); if (s->dlgret < 0) { do { - crReturn(0); + crReturnV; if (pktin) { bombout(("Unexpected data from server while" " waiting for user response")); - crStop(0); + crStopV; } } while (pktin || inlen > 0); s->dlgret = ssh->user_response; @@ -5933,7 +6948,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, if (s->dlgret == 0) { ssh_disconnect(ssh, "User aborted at cipher warning", NULL, 0, TRUE); - crStop(0); + crStopV; } } @@ -5945,11 +6960,11 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh_dialog_callback, ssh); if (s->dlgret < 0) { do { - crReturn(0); + crReturnV; if (pktin) { bombout(("Unexpected data from server while" " waiting for user response")); - crStop(0); + crStopV; } } while (pktin || inlen > 0); s->dlgret = ssh->user_response; @@ -5958,22 +6973,12 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, if (s->dlgret == 0) { ssh_disconnect(ssh, "User aborted at cipher warning", NULL, 0, TRUE); - crStop(0); + crStopV; } } - ssh->exhash = ssh->kex->hash->init(); - hash_string(ssh->kex->hash, ssh->exhash, ssh->v_c, strlen(ssh->v_c)); - hash_string(ssh->kex->hash, ssh->exhash, ssh->v_s, strlen(ssh->v_s)); - hash_string(ssh->kex->hash, ssh->exhash, - s->our_kexinit, s->our_kexinitlen); - sfree(s->our_kexinit); - if (pktin->length > 5) - hash_string(ssh->kex->hash, ssh->exhash, - pktin->data + 5, pktin->length - 5); - if (s->ignorepkt) /* first_kex_packet_follows */ - crWaitUntil(pktin); /* Ignore packet */ + crWaitUntilV(pktin); /* Ignore packet */ } if (ssh->kex->main_type == KEXTYPE_DH) { @@ -5985,8 +6990,8 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, { int csbits, scbits; - csbits = s->cscipher_tobe->keylen; - scbits = s->sccipher_tobe->keylen; + csbits = s->cscipher_tobe ? s->cscipher_tobe->real_keybits : 0; + scbits = s->sccipher_tobe ? s->sccipher_tobe->real_keybits : 0; s->nbits = (csbits > scbits ? csbits : scbits); } /* The keys only have hlen-bit entropy, since they're based on @@ -5998,7 +7003,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * If we're doing Diffie-Hellman group exchange, start by * requesting a group. */ - if (!ssh->kex->pdata) { + if (dh_is_gex(ssh->kex)) { logevent("Doing Diffie-Hellman group exchange"); ssh->pkt_kctx = SSH2_PKTCTX_DHGEX; /* @@ -6006,20 +7011,31 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * much data. */ s->pbits = 512 << ((s->nbits - 1) / 64); - s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); - ssh2_pkt_adduint32(s->pktout, s->pbits); + if (s->pbits < DH_MIN_SIZE) + s->pbits = DH_MIN_SIZE; + if (s->pbits > DH_MAX_SIZE) + s->pbits = DH_MAX_SIZE; + if ((ssh->remote_bugs & BUG_SSH2_OLDGEX)) { + s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST_OLD); + ssh2_pkt_adduint32(s->pktout, s->pbits); + } else { + s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST); + ssh2_pkt_adduint32(s->pktout, DH_MIN_SIZE); + ssh2_pkt_adduint32(s->pktout, s->pbits); + ssh2_pkt_adduint32(s->pktout, DH_MAX_SIZE); + } ssh2_pkt_send_noqueue(ssh, s->pktout); - crWaitUntil(pktin); + crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) { bombout(("expected key exchange group packet from server")); - crStop(0); + crStopV; } s->p = ssh2_pkt_getmp(pktin); s->g = ssh2_pkt_getmp(pktin); if (!s->p || !s->g) { bombout(("unable to read mp-ints from incoming group packet")); - crStop(0); + crStopV; } ssh->kex_ctx = dh_setup_gex(s->p, s->g); s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT; @@ -6045,21 +7061,37 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh2_pkt_send_noqueue(ssh, s->pktout); set_busy_status(ssh->frontend, BUSY_WAITING); /* wait for server */ - crWaitUntil(pktin); + crWaitUntilV(pktin); if (pktin->type != s->kex_reply_value) { bombout(("expected key exchange reply packet from server")); - crStop(0); + crStopV; } set_busy_status(ssh->frontend, BUSY_CPU); /* cogitate */ ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); - s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); + if (!s->hostkeydata) { + bombout(("unable to parse key exchange reply packet")); + crStopV; + } + s->hkey = ssh->hostkey->newkey(ssh->hostkey, + s->hostkeydata, s->hostkeylen); s->f = ssh2_pkt_getmp(pktin); if (!s->f) { bombout(("unable to parse key exchange reply packet")); - crStop(0); + crStopV; } ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + if (!s->sigdata) { + bombout(("unable to parse key exchange reply packet")); + crStopV; + } + { + const char *err = dh_validate_f(ssh->kex_ctx, s->f); + if (err) { + bombout(("key exchange reply failed validation: %s", err)); + crStopV; + } + } s->K = dh_find_K(ssh->kex_ctx, s->f); /* We assume everything from now on will be quick, and it might @@ -6067,8 +7099,12 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, set_busy_status(ssh->frontend, BUSY_NOT); hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); - if (!ssh->kex->pdata) { + if (dh_is_gex(ssh->kex)) { + if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX)) + hash_uint32(ssh->kex->hash, ssh->exhash, DH_MIN_SIZE); hash_uint32(ssh->kex->hash, ssh->exhash, s->pbits); + if (!(ssh->remote_bugs & BUG_SSH2_OLDGEX)) + hash_uint32(ssh->kex->hash, ssh->exhash, DH_MAX_SIZE); hash_mpint(ssh->kex->hash, ssh->exhash, s->p); hash_mpint(ssh->kex->hash, ssh->exhash, s->g); } @@ -6077,10 +7113,94 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, dh_cleanup(ssh->kex_ctx); freebn(s->f); - if (!ssh->kex->pdata) { + if (dh_is_gex(ssh->kex)) { freebn(s->g); freebn(s->p); } + } else if (ssh->kex->main_type == KEXTYPE_ECDH) { + + logeventf(ssh, "Doing ECDH key exchange with curve %s and hash %s", + ssh_ecdhkex_curve_textname(ssh->kex), + ssh->kex->hash->text_name); + ssh->pkt_kctx = SSH2_PKTCTX_ECDHKEX; + + s->eckey = ssh_ecdhkex_newkey(ssh->kex); + if (!s->eckey) { + bombout(("Unable to generate key for ECDH")); + crStopV; + } + + { + char *publicPoint; + int publicPointLength; + publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength); + if (!publicPoint) { + ssh_ecdhkex_freekey(s->eckey); + bombout(("Unable to encode public key for ECDH")); + crStopV; + } + s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_ECDH_INIT); + ssh2_pkt_addstring_start(s->pktout); + ssh2_pkt_addstring_data(s->pktout, publicPoint, publicPointLength); + sfree(publicPoint); + } + + ssh2_pkt_send_noqueue(ssh, s->pktout); + + crWaitUntilV(pktin); + if (pktin->type != SSH2_MSG_KEX_ECDH_REPLY) { + ssh_ecdhkex_freekey(s->eckey); + bombout(("expected ECDH reply packet from server")); + crStopV; + } + + ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); + if (!s->hostkeydata) { + bombout(("unable to parse ECDH reply packet")); + crStopV; + } + hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); + s->hkey = ssh->hostkey->newkey(ssh->hostkey, + s->hostkeydata, s->hostkeylen); + + { + char *publicPoint; + int publicPointLength; + publicPoint = ssh_ecdhkex_getpublic(s->eckey, &publicPointLength); + if (!publicPoint) { + ssh_ecdhkex_freekey(s->eckey); + bombout(("Unable to encode public key for ECDH hash")); + crStopV; + } + hash_string(ssh->kex->hash, ssh->exhash, + publicPoint, publicPointLength); + sfree(publicPoint); + } + + { + char *keydata; + int keylen; + ssh_pkt_getstring(pktin, &keydata, &keylen); + if (!keydata) { + bombout(("unable to parse ECDH reply packet")); + crStopV; + } + hash_string(ssh->kex->hash, ssh->exhash, keydata, keylen); + s->K = ssh_ecdhkex_getkey(s->eckey, keydata, keylen); + if (!s->K) { + ssh_ecdhkex_freekey(s->eckey); + bombout(("point received in ECDH was not valid")); + crStopV; + } + } + + ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + if (!s->sigdata) { + bombout(("unable to parse key exchange reply packet")); + crStopV; + } + + ssh_ecdhkex_freekey(s->eckey); } else { logeventf(ssh, "Doing RSA key exchange with hash %s", ssh->kex->hash->text_name); @@ -6089,20 +7209,29 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * RSA key exchange. First expect a KEXRSA_PUBKEY packet * from the server. */ - crWaitUntil(pktin); + crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_KEXRSA_PUBKEY) { bombout(("expected RSA public key packet from server")); - crStop(0); + crStopV; } ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen); + if (!s->hostkeydata) { + bombout(("unable to parse RSA public key packet")); + crStopV; + } hash_string(ssh->kex->hash, ssh->exhash, s->hostkeydata, s->hostkeylen); - s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen); + s->hkey = ssh->hostkey->newkey(ssh->hostkey, + s->hostkeydata, s->hostkeylen); { char *keydata; ssh_pkt_getstring(pktin, &keydata, &s->rsakeylen); + if (!keydata) { + bombout(("unable to parse RSA public key packet")); + crStopV; + } s->rsakeydata = snewn(s->rsakeylen, char); memcpy(s->rsakeydata, keydata, s->rsakeylen); } @@ -6111,7 +7240,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, if (!s->rsakey) { sfree(s->rsakeydata); bombout(("unable to parse RSA public key from server")); - crStop(0); + crStopV; } hash_string(ssh->kex->hash, ssh->exhash, s->rsakeydata, s->rsakeylen); @@ -6171,14 +7300,18 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, ssh_rsakex_freekey(s->rsakey); - crWaitUntil(pktin); + crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_KEXRSA_DONE) { sfree(s->rsakeydata); bombout(("expected signature packet from server")); - crStop(0); + crStopV; } ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen); + if (!s->sigdata) { + bombout(("unable to parse signature packet")); + crStopV; + } sfree(s->rsakeydata); } @@ -6194,49 +7327,133 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, dmemdump(s->exchange_hash, ssh->kex->hash->hlen); #endif - if (!s->hkey || - !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, + if (!s->hkey) { + bombout(("Server's host key is invalid")); + crStopV; + } + + if (!ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen, (char *)s->exchange_hash, ssh->kex->hash->hlen)) { +#ifndef FUZZING bombout(("Server's host key did not match the signature supplied")); - crStop(0); + crStopV; +#endif } - /* - * Authenticate remote host: verify host key. (We've already - * checked the signature of the exchange hash.) - */ s->keystr = ssh->hostkey->fmtkey(s->hkey); - s->fingerprint = ssh->hostkey->fingerprint(s->hkey); - ssh_set_frozen(ssh, 1); - s->dlgret = verify_ssh_host_key(ssh->frontend, - ssh->savedhost, ssh->savedport, - ssh->hostkey->keytype, s->keystr, - s->fingerprint, - ssh_dialog_callback, ssh); - if (s->dlgret < 0) { - do { - crReturn(0); - if (pktin) { - bombout(("Unexpected data from server while waiting" - " for user host key response")); - crStop(0); + if (!s->got_session_id) { + /* + * Make a note of any other host key formats that are available. + */ + { + int i, j, nkeys = 0; + char *list = NULL; + for (i = 0; i < lenof(hostkey_algs); i++) { + if (hostkey_algs[i].alg == ssh->hostkey) + continue; + + for (j = 0; j < ssh->n_uncert_hostkeys; j++) + if (ssh->uncert_hostkeys[j] == i) + break; + + if (j < ssh->n_uncert_hostkeys) { + char *newlist; + if (list) + newlist = dupprintf("%s/%s", list, + hostkey_algs[i].alg->name); + else + newlist = dupprintf("%s", hostkey_algs[i].alg->name); + sfree(list); + list = newlist; + nkeys++; + } + } + if (list) { + logeventf(ssh, + "Server also has %s host key%s, but we " + "don't know %s", list, + nkeys > 1 ? "s" : "", + nkeys > 1 ? "any of them" : "it"); + sfree(list); + } + } + + /* + * Authenticate remote host: verify host key. (We've already + * checked the signature of the exchange hash.) + */ + s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey); + logevent("Host key fingerprint is:"); + logevent(s->fingerprint); + /* First check against manually configured host keys. */ + s->dlgret = verify_ssh_manual_host_key(ssh, s->fingerprint, + ssh->hostkey, s->hkey); + if (s->dlgret == 0) { /* did not match */ + bombout(("Host key did not appear in manually configured list")); + crStopV; + } else if (s->dlgret < 0) { /* none configured; use standard handling */ + ssh_set_frozen(ssh, 1); + s->dlgret = verify_ssh_host_key(ssh->frontend, + ssh->savedhost, ssh->savedport, + ssh->hostkey->keytype, s->keystr, + s->fingerprint, + ssh_dialog_callback, ssh); +#ifdef FUZZING + s->dlgret = 1; +#endif + if (s->dlgret < 0) { + do { + crReturnV; + if (pktin) { + bombout(("Unexpected data from server while waiting" + " for user host key response")); + crStopV; + } + } while (pktin || inlen > 0); + s->dlgret = ssh->user_response; } - } while (pktin || inlen > 0); - s->dlgret = ssh->user_response; - } - ssh_set_frozen(ssh, 0); - if (s->dlgret == 0) { - ssh_disconnect(ssh, "User aborted at host key verification", NULL, - 0, TRUE); - crStop(0); - } - if (!s->got_session_id) { /* don't bother logging this in rekeys */ - logevent("Host key fingerprint is:"); - logevent(s->fingerprint); + ssh_set_frozen(ssh, 0); + if (s->dlgret == 0) { + ssh_disconnect(ssh, "Aborted at host key verification", NULL, + 0, TRUE); + crStopV; + } + } + sfree(s->fingerprint); + /* + * Save this host key, to check against the one presented in + * subsequent rekeys. + */ + ssh->hostkey_str = s->keystr; + } else if (ssh->cross_certifying) { + s->fingerprint = ssh2_fingerprint(ssh->hostkey, s->hkey); + logevent("Storing additional host key for this host:"); + logevent(s->fingerprint); + sfree(s->fingerprint); + store_host_key(ssh->savedhost, ssh->savedport, + ssh->hostkey->keytype, s->keystr); + ssh->cross_certifying = FALSE; + /* + * Don't forget to store the new key as the one we'll be + * re-checking in future normal rekeys. + */ + ssh->hostkey_str = s->keystr; + } else { + /* + * In a rekey, we never present an interactive host key + * verification request to the user. Instead, we simply + * enforce that the key we're seeing this time is identical to + * the one we saw before. + */ + if (strcmp(ssh->hostkey_str, s->keystr)) { +#ifndef FUZZING + bombout(("Host key was different in repeat key exchange")); + crStopV; +#endif + } + sfree(s->keystr); } - sfree(s->fingerprint); - sfree(s->keystr); ssh->hostkey->freekey(s->hkey); /* @@ -6267,12 +7484,14 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, if (ssh->cs_cipher_ctx) ssh->cscipher->free_context(ssh->cs_cipher_ctx); ssh->cscipher = s->cscipher_tobe; - ssh->cs_cipher_ctx = ssh->cscipher->make_context(); + if (ssh->cscipher) ssh->cs_cipher_ctx = ssh->cscipher->make_context(); if (ssh->cs_mac_ctx) ssh->csmac->free_context(ssh->cs_mac_ctx); ssh->csmac = s->csmac_tobe; - ssh->cs_mac_ctx = ssh->csmac->make_context(); + ssh->csmac_etm = s->csmac_etm_tobe; + if (ssh->csmac) + ssh->cs_mac_ctx = ssh->csmac->make_context(ssh->cs_cipher_ctx); if (ssh->cs_comp_ctx) ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx); @@ -6283,28 +7502,39 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * Set IVs on client-to-server keys. Here we use the exchange * hash from the _first_ key exchange. */ - { - unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; - assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh2_mkkey(ssh,s->K,s->exchange_hash,'C',keyspace); - assert((ssh->cscipher->keylen+7) / 8 <= - ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,'A',keyspace); - assert(ssh->cscipher->blksize <= - ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,'E',keyspace); - assert(ssh->csmac->len <= - ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace); - smemclr(keyspace, sizeof(keyspace)); - } - - logeventf(ssh, "Initialised %.200s client->server encryption", - ssh->cscipher->text_name); - logeventf(ssh, "Initialised %.200s client->server MAC algorithm", - ssh->csmac->text_name); + if (ssh->cscipher) { + unsigned char *key; + + key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'C', + ssh->cscipher->padded_keybytes); + ssh->cscipher->setkey(ssh->cs_cipher_ctx, key); + smemclr(key, ssh->cscipher->padded_keybytes); + sfree(key); + + key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'A', + ssh->cscipher->blksize); + ssh->cscipher->setiv(ssh->cs_cipher_ctx, key); + smemclr(key, ssh->cscipher->blksize); + sfree(key); + } + if (ssh->csmac) { + unsigned char *key; + + key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'E', + ssh->csmac->keylen); + ssh->csmac->setkey(ssh->cs_mac_ctx, key); + smemclr(key, ssh->csmac->keylen); + sfree(key); + } + + if (ssh->cscipher) + logeventf(ssh, "Initialised %.200s client->server encryption", + ssh->cscipher->text_name); + if (ssh->csmac) + logeventf(ssh, "Initialised %.200s client->server MAC algorithm%s%s", + ssh->csmac->text_name, + ssh->csmac_etm ? " (in ETM mode)" : "", + ssh->cscipher->required_mac ? " (required by cipher)" : ""); if (ssh->cscomp->text_name) logeventf(ssh, "Initialised %s compression", ssh->cscomp->text_name); @@ -6319,10 +7549,10 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, /* * Expect SSH2_MSG_NEWKEYS from server. */ - crWaitUntil(pktin); + crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_NEWKEYS) { bombout(("expected new-keys packet from server")); - crStop(0); + crStopV; } ssh->incoming_data_size = 0; /* start counting from here */ @@ -6332,13 +7562,18 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, */ if (ssh->sc_cipher_ctx) ssh->sccipher->free_context(ssh->sc_cipher_ctx); - ssh->sccipher = s->sccipher_tobe; - ssh->sc_cipher_ctx = ssh->sccipher->make_context(); + if (s->sccipher_tobe) { + ssh->sccipher = s->sccipher_tobe; + ssh->sc_cipher_ctx = ssh->sccipher->make_context(); + } if (ssh->sc_mac_ctx) ssh->scmac->free_context(ssh->sc_mac_ctx); - ssh->scmac = s->scmac_tobe; - ssh->sc_mac_ctx = ssh->scmac->make_context(); + if (s->scmac_tobe) { + ssh->scmac = s->scmac_tobe; + ssh->scmac_etm = s->scmac_etm_tobe; + ssh->sc_mac_ctx = ssh->scmac->make_context(ssh->sc_cipher_ctx); + } if (ssh->sc_comp_ctx) ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx); @@ -6349,27 +7584,38 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, * Set IVs on server-to-client keys. Here we use the exchange * hash from the _first_ key exchange. */ - { - unsigned char keyspace[SSH2_KEX_MAX_HASH_LEN * SSH2_MKKEY_ITERS]; - assert(sizeof(keyspace) >= ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh2_mkkey(ssh,s->K,s->exchange_hash,'D',keyspace); - assert((ssh->sccipher->keylen+7) / 8 <= - ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,'B',keyspace); - assert(ssh->sccipher->blksize <= - ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace); - ssh2_mkkey(ssh,s->K,s->exchange_hash,'F',keyspace); - assert(ssh->scmac->len <= - ssh->kex->hash->hlen * SSH2_MKKEY_ITERS); - ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace); - smemclr(keyspace, sizeof(keyspace)); - } - logeventf(ssh, "Initialised %.200s server->client encryption", - ssh->sccipher->text_name); - logeventf(ssh, "Initialised %.200s server->client MAC algorithm", - ssh->scmac->text_name); + if (ssh->sccipher) { + unsigned char *key; + + key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'D', + ssh->sccipher->padded_keybytes); + ssh->sccipher->setkey(ssh->sc_cipher_ctx, key); + smemclr(key, ssh->sccipher->padded_keybytes); + sfree(key); + + key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'B', + ssh->sccipher->blksize); + ssh->sccipher->setiv(ssh->sc_cipher_ctx, key); + smemclr(key, ssh->sccipher->blksize); + sfree(key); + } + if (ssh->scmac) { + unsigned char *key; + + key = ssh2_mkkey(ssh, s->K, s->exchange_hash, 'F', + ssh->scmac->keylen); + ssh->scmac->setkey(ssh->sc_mac_ctx, key); + smemclr(key, ssh->scmac->keylen); + sfree(key); + } + if (ssh->sccipher) + logeventf(ssh, "Initialised %.200s server->client encryption", + ssh->sccipher->text_name); + if (ssh->scmac) + logeventf(ssh, "Initialised %.200s server->client MAC algorithm%s%s", + ssh->scmac->text_name, + ssh->scmac_etm ? " (in ETM mode)" : "", + ssh->sccipher->required_mac ? " (required by cipher)" : ""); if (ssh->sccomp->text_name) logeventf(ssh, "Initialised %s decompression", ssh->sccomp->text_name); @@ -6379,6 +7625,12 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, */ freebn(s->K); + /* + * Update the specials menu to list the remaining uncertified host + * keys. + */ + update_specials_menu(ssh->frontend); + /* * Key exchange is over. Loop straight back round if we have a * deferred rekey reason. @@ -6424,7 +7676,7 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, */ do_ssh2_authconn(ssh, NULL, 0, NULL); } - crReturn(1); + crReturnV; } if (pktin) { logevent("Server initiated key re-exchange"); @@ -6483,16 +7735,34 @@ static int do_ssh2_transport(Ssh ssh, void *vin, int inlen, } goto begin_key_exchange; - crFinish(1); + crFinishV; } /* - * Add data to an SSH-2 channel output buffer. + * Send data on an SSH channel. In SSH-2, this involves buffering it + * first. */ -static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, - int len) +static int ssh_send_channel_data(struct ssh_channel *c, const char *buf, + int len) { - bufchain_add(&c->v.v2.outbuffer, buf, len); + if (c->ssh->version == 2) { + bufchain_add(&c->v.v2.outbuffer, buf, len); + return ssh2_try_send(c); + } else { + send_packet(c->ssh, SSH1_MSG_CHANNEL_DATA, + PKT_INT, c->remoteid, + PKT_INT, len, + PKT_DATA, buf, len, + PKT_END); + /* + * In SSH-1 we can return 0 here - implying that channels are + * never individually throttled - because the only + * circumstance that can cause throttling will be the whole + * SSH connection backing up, in which case _everything_ will + * be throttled as a whole. + */ + return 0; + } } /* @@ -6515,9 +7785,7 @@ static int ssh2_try_send(struct ssh_channel *c) pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA); ssh2_pkt_adduint32(pktout, c->remoteid); ssh2_pkt_addstring_start(pktout); - dont_log_data(ssh, pktout, PKTLOG_OMIT); ssh2_pkt_addstring_data(pktout, data, len); - end_log_omission(ssh, pktout); ssh2_pkt_send(ssh, pktout); bufchain_consume(&c->v.v2.outbuffer, len); c->v.v2.remwindow -= len; @@ -6552,34 +7820,67 @@ static void ssh2_try_send_and_unthrottle(Ssh ssh, struct ssh_channel *c) * notification since it will be polled */ break; case CHAN_X11: - x11_unthrottle(c->u.x11.s); + x11_unthrottle(c->u.x11.xconn); break; case CHAN_AGENT: - /* agent sockets are request/response and need no - * buffer management */ + /* Now that we've successfully sent all the outgoing + * replies we had, try to process more incoming data. */ + ssh_agentf_try_forward(c); break; case CHAN_SOCKDATA: - pfd_unthrottle(c->u.pfd.s); + pfd_unthrottle(c->u.pfd.pf); break; } } } +static int ssh_is_simple(Ssh ssh) +{ + /* + * We use the 'simple' variant of the SSH protocol if we're asked + * to, except not if we're also doing connection-sharing (either + * tunnelling our packets over an upstream or expecting to be + * tunnelled over ourselves), since then the assumption that we + * have only one channel to worry about is not true after all. + */ + return (conf_get_int(ssh->conf, CONF_ssh_simple) && + !ssh->bare_connection && !ssh->connshare); +} + /* - * Set up most of a new ssh_channel for SSH-2. + * Set up most of a new ssh_channel. */ -static void ssh2_channel_init(struct ssh_channel *c) +static void ssh_channel_init(struct ssh_channel *c) { Ssh ssh = c->ssh; c->localid = alloc_channel_id(ssh); c->closes = 0; c->pending_eof = FALSE; c->throttling_conn = FALSE; - c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = - conf_get_int(ssh->conf, CONF_ssh_simple) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; - c->v.v2.chanreq_head = NULL; - c->v.v2.throttle_state = UNTHROTTLED; - bufchain_init(&c->v.v2.outbuffer); + if (ssh->version == 2) { + c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = + ssh_is_simple(ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE; + c->v.v2.chanreq_head = NULL; + c->v.v2.throttle_state = UNTHROTTLED; + bufchain_init(&c->v.v2.outbuffer); + } + add234(ssh->channels, c); +} + +/* + * Construct the common parts of a CHANNEL_OPEN. + */ +static struct Packet *ssh2_chanopen_init(struct ssh_channel *c, + const char *type) +{ + struct Packet *pktout; + + pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); + ssh2_pkt_addstring(pktout, type); + ssh2_pkt_adduint32(pktout, c->localid); + ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ + ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ + return pktout; } /* @@ -6611,12 +7912,14 @@ static void ssh2_queue_chanreq_handler(struct ssh_channel *c, * request-specific data added and be sent. Note that if a handler is * provided, it's essential that the request actually be sent. * - * The handler will usually be passed the response packet in pktin. - * If pktin is NULL, this means that no reply will ever be forthcoming - * (e.g. because the entire connection is being destroyed) and the - * handler should free any storage it's holding. + * The handler will usually be passed the response packet in pktin. If + * pktin is NULL, this means that no reply will ever be forthcoming + * (e.g. because the entire connection is being destroyed, or because + * the server initiated channel closure before we saw the response) + * and the handler should free any storage it's holding. */ -static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type, +static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, + const char *type, cchandler_fn_t handler, void *ctx) { struct Packet *pktout; @@ -6631,6 +7934,27 @@ static struct Packet *ssh2_chanreq_init(struct ssh_channel *c, char *type, return pktout; } +static void ssh_channel_unthrottle(struct ssh_channel *c, int bufsize) +{ + Ssh ssh = c->ssh; + int buflimit; + + if (ssh->version == 1) { + buflimit = SSH1_BUFFER_LIMIT; + } else { + if (ssh_is_simple(ssh)) + buflimit = 0; + else + buflimit = c->v.v2.locmaxwin; + if (bufsize < buflimit) + ssh2_set_window(c, buflimit - bufsize); + } + if (c->throttling_conn && bufsize <= buflimit) { + c->throttling_conn = 0; + ssh_throttle_conn(ssh, -1); + } +} + /* * Potentially enlarge the window on an SSH-2 channel. */ @@ -6649,6 +7973,14 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin) if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE)) return; + /* + * Also, never widen the window for an X11 channel when we're + * still waiting to see its initial auth and may yet hand it off + * to a downstream. + */ + if (c->type == CHAN_X11 && c->u.x11.initial) + return; + /* * If the remote end has a habit of ignoring maxpkt, limit the * window so that it has no choice (assuming it doesn't ignore the @@ -6704,24 +8036,38 @@ static void ssh2_set_window(struct ssh_channel *c, int newwin) /* * Find the channel associated with a message. If there's no channel, * or it's not properly open, make a noise about it and return NULL. + * If the channel is shared, pass the message on to downstream and + * also return NULL (meaning the caller should ignore this message). */ -static struct ssh_channel *ssh2_channel_msg(Ssh ssh, struct Packet *pktin) +static struct ssh_channel *ssh_channel_msg(Ssh ssh, struct Packet *pktin) { unsigned localid = ssh_pkt_getuint32(pktin); struct ssh_channel *c; + int halfopen_ok; + /* Is this message OK on a half-open connection? */ + if (ssh->version == 1) + halfopen_ok = (pktin->type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION || + pktin->type == SSH1_MSG_CHANNEL_OPEN_FAILURE); + else + halfopen_ok = (pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION || + pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE); c = find234(ssh->channels, &localid, ssh_channelfind); - if (!c || - (c->halfopen && pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION && - pktin->type != SSH2_MSG_CHANNEL_OPEN_FAILURE)) { + if (!c || (c->type != CHAN_SHARING && (c->halfopen != halfopen_ok))) { char *buf = dupprintf("Received %s for %s channel %u", - ssh2_pkt_type(ssh->pkt_kctx, ssh->pkt_actx, - pktin->type), - c ? "half-open" : "nonexistent", localid); + ssh_pkt_type(ssh, pktin->type), + !c ? "nonexistent" : + c->halfopen ? "half-open" : "open", + localid); ssh_disconnect(ssh, NULL, buf, SSH2_DISCONNECT_PROTOCOL_ERROR, FALSE); sfree(buf); return NULL; } + if (c->type == CHAN_SHARING) { + share_got_pkt_from_server(c->u.sharing.ctx, pktin->type, + pktin->body, pktin->length); + return NULL; + } return c; } @@ -6751,7 +8097,7 @@ static void ssh2_handle_winadj_response(struct ssh_channel *c, static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin) { - struct ssh_channel *c = ssh2_channel_msg(ssh, pktin); + struct ssh_channel *c = ssh_channel_msg(ssh, pktin); struct outstanding_channel_request *ocr; if (!c) return; @@ -6774,7 +8120,7 @@ static void ssh2_msg_channel_response(Ssh ssh, struct Packet *pktin) static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin) { struct ssh_channel *c; - c = ssh2_channel_msg(ssh, pktin); + c = ssh_channel_msg(ssh, pktin); if (!c) return; if (!(c->closes & CLOSES_SENT_EOF)) { @@ -6787,75 +8133,22 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) { char *data; int length; + unsigned ext_type = 0; /* 0 means not extended */ struct ssh_channel *c; - c = ssh2_channel_msg(ssh, pktin); + c = ssh_channel_msg(ssh, pktin); if (!c) return; - if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA && - ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR) - return; /* extended but not stderr */ + if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) + ext_type = ssh_pkt_getuint32(pktin); ssh_pkt_getstring(pktin, &data, &length); if (data) { - int bufsize = 0; + int bufsize; c->v.v2.locwindow -= length; c->v.v2.remlocwin -= length; - switch (c->type) { - case CHAN_MAINSESSION: - bufsize = - from_backend(ssh->frontend, pktin->type == - SSH2_MSG_CHANNEL_EXTENDED_DATA, - data, length); - break; - case CHAN_X11: - bufsize = x11_send(c->u.x11.s, data, length); - break; - case CHAN_SOCKDATA: - bufsize = pfd_send(c->u.pfd.s, data, length); - break; - case CHAN_AGENT: - while (length > 0) { - if (c->u.a.lensofar < 4) { - unsigned int l = min(4 - c->u.a.lensofar, - (unsigned)length); - memcpy(c->u.a.msglen + c->u.a.lensofar, - data, l); - data += l; - length -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == 4) { - c->u.a.totallen = - 4 + GET_32BIT(c->u.a.msglen); - c->u.a.message = snewn(c->u.a.totallen, - unsigned char); - memcpy(c->u.a.message, c->u.a.msglen, 4); - } - if (c->u.a.lensofar >= 4 && length > 0) { - unsigned int l = - min(c->u.a.totallen - c->u.a.lensofar, - (unsigned)length); - memcpy(c->u.a.message + c->u.a.lensofar, - data, l); - data += l; - length -= l; - c->u.a.lensofar += l; - } - if (c->u.a.lensofar == c->u.a.totallen) { - void *reply; - int replylen; - if (agent_query(c->u.a.message, - c->u.a.totallen, - &reply, &replylen, - ssh_agentf_callback, c)) - ssh_agentf_callback(c, reply, replylen); - sfree(c->u.a.message); - c->u.a.message = NULL; - c->u.a.lensofar = 0; - } - } - bufsize = 0; - break; - } + if (ext_type != 0 && ext_type != SSH2_EXTENDED_DATA_STDERR) + length = 0; /* Don't do anything with unknown extended data. */ + bufsize = ssh_channel_data(c, ext_type == SSH2_EXTENDED_DATA_STDERR, + data, length); /* * If it looks like the remote end hit the end of its window, * and we didn't want it to do that, think about using a @@ -6871,25 +8164,79 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin) * need to adjust the window if the server's * sent excess data. */ - ssh2_set_window(c, bufsize < c->v.v2.locmaxwin ? - c->v.v2.locmaxwin - bufsize : 0); + if (bufsize < c->v.v2.locmaxwin) + ssh2_set_window(c, c->v.v2.locmaxwin - bufsize); /* * If we're either buffering way too much data, or if we're * buffering anything at all and we're in "simple" mode, * throttle the whole channel. */ - if ((bufsize > c->v.v2.locmaxwin || - (conf_get_int(ssh->conf, CONF_ssh_simple) && bufsize > 0)) && - !c->throttling_conn) { + if ((bufsize > c->v.v2.locmaxwin || (ssh_is_simple(ssh) && bufsize>0)) + && !c->throttling_conn) { c->throttling_conn = 1; ssh_throttle_conn(ssh, +1); } } } -static void ssh_channel_destroy(struct ssh_channel *c) +static void ssh_check_termination(Ssh ssh) +{ + if (ssh->version == 2 && + !conf_get_int(ssh->conf, CONF_ssh_no_shell) && + (ssh->channels && count234(ssh->channels) == 0) && + !(ssh->connshare && share_ndownstreams(ssh->connshare) > 0)) { + /* + * We used to send SSH_MSG_DISCONNECT here, because I'd + * believed that _every_ conforming SSH-2 connection had to + * end with a disconnect being sent by at least one side; + * apparently I was wrong and it's perfectly OK to + * unceremoniously slam the connection shut when you're done, + * and indeed OpenSSH feels this is more polite than sending a + * DISCONNECT. So now we don't. + */ + ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); + } +} + +void ssh_sharing_downstream_connected(Ssh ssh, unsigned id, + const char *peerinfo) +{ + if (peerinfo) + logeventf(ssh, "Connection sharing downstream #%u connected from %s", + id, peerinfo); + else + logeventf(ssh, "Connection sharing downstream #%u connected", id); +} + +void ssh_sharing_downstream_disconnected(Ssh ssh, unsigned id) +{ + logeventf(ssh, "Connection sharing downstream #%u disconnected", id); + ssh_check_termination(ssh); +} + +void ssh_sharing_logf(Ssh ssh, unsigned id, const char *logfmt, ...) +{ + va_list ap; + char *buf; + + va_start(ap, logfmt); + buf = dupvprintf(logfmt, ap); + va_end(ap); + if (id) + logeventf(ssh, "Connection sharing downstream #%u: %s", id, buf); + else + logeventf(ssh, "Connection sharing: %s", buf); + sfree(buf); +} + +/* + * Close any local socket and free any local resources associated with + * a channel. This converts the channel into a CHAN_ZOMBIE. + */ +static void ssh_channel_close_local(struct ssh_channel *c, char const *reason) { Ssh ssh = c->ssh; + char const *msg = NULL; switch (c->type) { case CHAN_MAINSESSION: @@ -6897,19 +8244,36 @@ static void ssh_channel_destroy(struct ssh_channel *c) update_specials_menu(ssh->frontend); break; case CHAN_X11: - if (c->u.x11.s != NULL) - x11_close(c->u.x11.s); - logevent("Forwarded X11 connection terminated"); + assert(c->u.x11.xconn != NULL); + x11_close(c->u.x11.xconn); + msg = "Forwarded X11 connection terminated"; break; case CHAN_AGENT: - sfree(c->u.a.message); + if (c->u.a.pending) + agent_cancel_query(c->u.a.pending); + bufchain_clear(&c->u.a.inbuffer); + msg = "Agent-forwarding connection closed"; break; case CHAN_SOCKDATA: - if (c->u.pfd.s != NULL) - pfd_close(c->u.pfd.s); - logevent("Forwarded port closed"); + assert(c->u.pfd.pf != NULL); + pfd_close(c->u.pfd.pf); + msg = "Forwarded port closed"; break; } + c->type = CHAN_ZOMBIE; + if (msg != NULL) { + if (reason != NULL) + logeventf(ssh, "%s %s", msg, reason); + else + logevent(msg); + } +} + +static void ssh_channel_destroy(struct ssh_channel *c) +{ + Ssh ssh = c->ssh; + + ssh_channel_close_local(c, NULL); del234(ssh->channels, c); if (ssh->version == 2) { @@ -6919,26 +8283,10 @@ static void ssh_channel_destroy(struct ssh_channel *c) sfree(c); /* - * See if that was the last channel left open. - * (This is only our termination condition if we're - * not running in -N mode.) + * If that was the last channel left open, we might need to + * terminate. */ - if (ssh->version == 2 && - !conf_get_int(ssh->conf, CONF_ssh_no_shell) && - count234(ssh->channels) == 0) { - /* - * We used to send SSH_MSG_DISCONNECT here, - * because I'd believed that _every_ conforming - * SSH-2 connection had to end with a disconnect - * being sent by at least one side; apparently - * I was wrong and it's perfectly OK to - * unceremoniously slam the connection shut - * when you're done, and indeed OpenSSH feels - * this is more polite than sending a - * DISCONNECT. So now we don't. - */ - ssh_disconnect(ssh, "All channels closed", NULL, 0, TRUE); - } + ssh_check_termination(ssh); } static void ssh2_channel_check_close(struct ssh_channel *c) @@ -6946,18 +8294,30 @@ static void ssh2_channel_check_close(struct ssh_channel *c) Ssh ssh = c->ssh; struct Packet *pktout; - if ((c->closes & (CLOSES_SENT_EOF | CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE)) - == (CLOSES_SENT_EOF | CLOSES_RCVD_EOF) && !c->v.v2.chanreq_head) { + assert(ssh->version == 2); + if (c->halfopen) { + /* + * If we've sent out our own CHANNEL_OPEN but not yet seen + * either OPEN_CONFIRMATION or OPEN_FAILURE in response, then + * it's too early to be sending close messages of any kind. + */ + return; + } + + if ((!((CLOSES_SENT_EOF | CLOSES_RCVD_EOF) & ~c->closes) || + c->type == CHAN_ZOMBIE) && + !c->v.v2.chanreq_head && + !(c->closes & CLOSES_SENT_CLOSE)) { /* - * We have both sent and received EOF, and we have no - * outstanding channel requests, which means the - * channel is in final wind-up. But we haven't sent CLOSE, so - * let's do so now. + * We have both sent and received EOF (or the channel is a + * zombie), and we have no outstanding channel requests, which + * means the channel is in final wind-up. But we haven't sent + * CLOSE, so let's do so now. */ pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE); ssh2_pkt_adduint32(pktout, c->remoteid); ssh2_pkt_send(ssh, pktout); - c->closes |= CLOSES_SENT_CLOSE; + c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE; } if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) { @@ -6970,19 +8330,23 @@ static void ssh2_channel_check_close(struct ssh_channel *c) } } -static void ssh2_channel_got_eof(struct ssh_channel *c) +static void ssh_channel_got_eof(struct ssh_channel *c) { if (c->closes & CLOSES_RCVD_EOF) return; /* already seen EOF */ c->closes |= CLOSES_RCVD_EOF; if (c->type == CHAN_X11) { - x11_send_eof(c->u.x11.s); + assert(c->u.x11.xconn != NULL); + x11_send_eof(c->u.x11.xconn); } else if (c->type == CHAN_AGENT) { - /* Manufacture an outgoing EOF in response to the incoming one. */ - sshfwd_write_eof(c); + /* Just call try_forward, which will respond to the EOF now if + * appropriate, or wait until the queue of outstanding + * requests is dealt with if not */ + ssh_agentf_try_forward(c); } else if (c->type == CHAN_SOCKDATA) { - pfd_send_eof(c->u.pfd.s); + assert(c->u.pfd.pf != NULL); + pfd_send_eof(c->u.pfd.pf); } else if (c->type == CHAN_MAINSESSION) { Ssh ssh = c->ssh; @@ -7000,25 +8364,24 @@ static void ssh2_channel_got_eof(struct ssh_channel *c) } ssh->sent_console_eof = TRUE; } - - ssh2_channel_check_close(c); } static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin) { struct ssh_channel *c; - c = ssh2_channel_msg(ssh, pktin); + c = ssh_channel_msg(ssh, pktin); if (!c) return; - ssh2_channel_got_eof(c); + ssh_channel_got_eof(c); + ssh2_channel_check_close(c); } static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) { struct ssh_channel *c; - c = ssh2_channel_msg(ssh, pktin); + c = ssh_channel_msg(ssh, pktin); if (!c) return; @@ -7026,7 +8389,22 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) * When we receive CLOSE on a channel, we assume it comes with an * implied EOF if we haven't seen EOF yet. */ - ssh2_channel_got_eof(c); + ssh_channel_got_eof(c); + + if (!(ssh->remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) { + /* + * It also means we stop expecting to see replies to any + * outstanding channel requests, so clean those up too. + * (ssh_chanreq_init will enforce by assertion that we don't + * subsequently put anything back on this list.) + */ + while (c->v.v2.chanreq_head) { + struct outstanding_channel_request *ocr = c->v.v2.chanreq_head; + ocr->handler(c, NULL, ocr->ctx); + c->v.v2.chanreq_head = ocr->next; + sfree(ocr); + } + } /* * And we also send an outgoing EOF, if we haven't already, on the @@ -7045,13 +8423,22 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin) ssh->send_ok = 0; /* stop trying to read from stdin */ break; case CHAN_X11: - x11_override_throttle(c->u.x11.s, 1); + x11_override_throttle(c->u.x11.xconn, 1); break; case CHAN_SOCKDATA: - pfd_override_throttle(c->u.pfd.s, 1); + pfd_override_throttle(c->u.pfd.pf, 1); break; } + /* + * Abandon any buffered data we still wanted to send to this + * channel. Receiving a CHANNEL_CLOSE is an indication that + * the server really wants to get on and _destroy_ this + * channel, and it isn't going to send us any further + * WINDOW_ADJUSTs to permit us to send pending stuff. + */ + bufchain_clear(&c->v.v2.outbuffer); + /* * Send outgoing EOF. */ @@ -7071,20 +8458,44 @@ static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin) { struct ssh_channel *c; - c = ssh2_channel_msg(ssh, pktin); + c = ssh_channel_msg(ssh, pktin); if (!c) return; - if (c->type != CHAN_SOCKDATA_DORMANT) - return; /* dunno why they're confirming this */ + assert(c->halfopen); /* ssh_channel_msg will have enforced this */ c->remoteid = ssh_pkt_getuint32(pktin); c->halfopen = FALSE; - c->type = CHAN_SOCKDATA; c->v.v2.remwindow = ssh_pkt_getuint32(pktin); c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); - if (c->u.pfd.s) - pfd_confirm(c->u.pfd.s); + + if (c->type == CHAN_SOCKDATA) { + assert(c->u.pfd.pf != NULL); + pfd_confirm(c->u.pfd.pf); + } else if (c->type == CHAN_ZOMBIE) { + /* + * This case can occur if a local socket error occurred + * between us sending out CHANNEL_OPEN and receiving + * OPEN_CONFIRMATION. In this case, all we can do is + * immediately initiate close proceedings now that we know the + * server's id to put in the close message. + */ + ssh2_channel_check_close(c); + } else { + /* + * We never expect to receive OPEN_CONFIRMATION for any + * *other* channel type (since only local-to-remote port + * forwardings cause us to send CHANNEL_OPEN after the main + * channel is live - all other auxiliary channel types are + * initiated from the server end). It's safe to enforce this + * by assertion rather than by ssh_disconnect, because the + * real point is that we never constructed a half-open channel + * structure in the first place with any type other than the + * above. + */ + assert(!"Funny channel type in ssh2_msg_channel_open_confirmation"); + } + if (c->pending_eof) - ssh_channel_try_eof(c); + ssh_channel_try_eof(c); /* in case we had a pending EOF */ } static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) @@ -7100,20 +8511,42 @@ static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin) char *reason_string; int reason_length; struct ssh_channel *c; - c = ssh2_channel_msg(ssh, pktin); + + c = ssh_channel_msg(ssh, pktin); if (!c) return; - if (c->type != CHAN_SOCKDATA_DORMANT) - return; /* dunno why they're failing this */ - - reason_code = ssh_pkt_getuint32(pktin); - if (reason_code >= lenof(reasons)) - reason_code = 0; /* ensure reasons[reason_code] in range */ - ssh_pkt_getstring(pktin, &reason_string, &reason_length); - logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", - reasons[reason_code], reason_length, reason_string); - - pfd_close(c->u.pfd.s); + assert(c->halfopen); /* ssh_channel_msg will have enforced this */ + + if (c->type == CHAN_SOCKDATA) { + reason_code = ssh_pkt_getuint32(pktin); + if (reason_code >= lenof(reasons)) + reason_code = 0; /* ensure reasons[reason_code] in range */ + ssh_pkt_getstring(pktin, &reason_string, &reason_length); + logeventf(ssh, "Forwarded connection refused by server: %s [%.*s]", + reasons[reason_code], reason_length, + NULLTOEMPTY(reason_string)); + + pfd_close(c->u.pfd.pf); + } else if (c->type == CHAN_ZOMBIE) { + /* + * This case can occur if a local socket error occurred + * between us sending out CHANNEL_OPEN and receiving + * OPEN_FAILURE. In this case, we need do nothing except allow + * the code below to throw the half-open channel away. + */ + } else { + /* + * We never expect to receive OPEN_FAILURE for any *other* + * channel type (since only local-to-remote port forwardings + * cause us to send CHANNEL_OPEN after the main channel is + * live - all other auxiliary channel types are initiated from + * the server end). It's safe to enforce this by assertion + * rather than by ssh_disconnect, because the real point is + * that we never constructed a half-open channel structure in + * the first place with any type other than the above. + */ + assert(!"Funny channel type in ssh2_msg_channel_open_failure"); + } del234(ssh->channels, c); sfree(c); @@ -7127,12 +8560,22 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) struct ssh_channel *c; struct Packet *pktout; - c = ssh2_channel_msg(ssh, pktin); + c = ssh_channel_msg(ssh, pktin); if (!c) return; ssh_pkt_getstring(pktin, &type, &typelen); want_reply = ssh2_pkt_getbool(pktin); + if (c->closes & CLOSES_SENT_CLOSE) { + /* + * We don't reply to channel requests after we've sent + * CHANNEL_CLOSE for the channel, because our reply might + * cross in the network with the other side's CHANNEL_CLOSE + * and arrive after they have wound the channel up completely. + */ + want_reply = FALSE; + } + /* * Having got the channel number, we now look at * the request type string to see if it's something @@ -7155,7 +8598,7 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) !memcmp(type, "exit-signal", 11)) { int is_plausible = TRUE, is_int = FALSE; - char *fmt_sig = "", *fmt_msg = ""; + char *fmt_sig = NULL, *fmt_msg = NULL; char *msg; int msglen = 0, core = FALSE; /* ICK: older versions of OpenSSH (e.g. 3.4p1) @@ -7173,16 +8616,18 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) is_int = FALSE; } else { int maybe_int = FALSE, maybe_str = FALSE; -#define CHECK_HYPOTHESIS(offset, result) \ - do { \ - long q = offset; \ - if (q >= 0 && q+4 <= len) { \ - q = q + 4 + GET_32BIT(p+q); \ - if (q >= 0 && q+4 <= len && \ - ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \ - result = TRUE; \ - } \ - } while(0) +#define CHECK_HYPOTHESIS(offset, result) \ + do \ + { \ + int q = toint(offset); \ + if (q >= 0 && q+4 <= len) { \ + q = toint(q + 4 + GET_32BIT(p+q)); \ + if (q >= 0 && q+4 <= len && \ + ((q = toint(q + 4 + GET_32BIT(p+q))) != 0) && \ + q == len) \ + result = TRUE; \ + } \ + } while(0) CHECK_HYPOTHESIS(4+1, maybe_int); CHECK_HYPOTHESIS(4+num+1, maybe_str); #undef CHECK_HYPOTHESIS @@ -7276,10 +8721,11 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin) /* ignore lang tag */ } /* else don't attempt to parse */ logeventf(ssh, "Server exited on signal%s%s%s", - fmt_sig, core ? " (core dumped)" : "", - fmt_msg); - if (*fmt_sig) sfree(fmt_sig); - if (*fmt_msg) sfree(fmt_msg); + fmt_sig ? fmt_sig : "", + core ? " (core dumped)" : "", + fmt_msg ? fmt_msg : ""); + sfree(fmt_sig); + sfree(fmt_msg); reply = SSH2_MSG_CHANNEL_SUCCESS; } @@ -7320,6 +8766,30 @@ static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin) } } +struct X11FakeAuth *ssh_sharing_add_x11_display(Ssh ssh, int authtype, + void *share_cs, + void *share_chan) +{ + struct X11FakeAuth *auth; + + /* + * Make up a new set of fake X11 auth data, and add it to the tree + * of currently valid ones with an indication of the sharing + * context that it's relevant to. + */ + auth = x11_invent_fake_auth(ssh->x11authtree, authtype); + auth->share_cs = share_cs; + auth->share_chan = share_chan; + + return auth; +} + +void ssh_sharing_remove_x11_display(Ssh ssh, struct X11FakeAuth *auth) +{ + del234(ssh->x11authtree, auth); + x11_free_fake_auth(auth); +} + static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) { char *type; @@ -7327,9 +8797,10 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) char *peeraddr; int peeraddrlen; int peerport; - char *error = NULL; + const char *error = NULL; struct ssh_channel *c; unsigned remid, winsize, pktsize; + unsigned our_winsize_override = 0; struct Packet *pktout; ssh_pkt_getstring(pktin, &type, &typelen); @@ -7342,53 +8813,78 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) if (typelen == 3 && !memcmp(type, "x11", 3)) { char *addrstr; - const char *x11err; ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); - addrstr = snewn(peeraddrlen+1, char); - memcpy(addrstr, peeraddr, peeraddrlen); - addrstr[peeraddrlen] = '\0'; + addrstr = dupprintf("%.*s", peeraddrlen, NULLTOEMPTY(peeraddr)); peerport = ssh_pkt_getuint32(pktin); logeventf(ssh, "Received X11 connect request from %s:%d", addrstr, peerport); - if (!ssh->X11_fwd_enabled) + if (!ssh->X11_fwd_enabled && !ssh->connshare) error = "X11 forwarding is not enabled"; - else if ((x11err = x11_init(&c->u.x11.s, ssh->x11disp, c, - addrstr, peerport, ssh->conf)) != NULL) { - logeventf(ssh, "Local X11 connection failed: %s", x11err); - error = "Unable to open an X11 connection"; - } else { - logevent("Opening X11 forward connection succeeded"); + else { + c->u.x11.xconn = x11_init(ssh->x11authtree, c, + addrstr, peerport); c->type = CHAN_X11; + c->u.x11.initial = TRUE; + + /* + * If we are a connection-sharing upstream, then we should + * initially present a very small window, adequate to take + * the X11 initial authorisation packet but not much more. + * Downstream will then present us a larger window (by + * fiat of the connection-sharing protocol) and we can + * guarantee to send a positive-valued WINDOW_ADJUST. + */ + if (ssh->connshare) + our_winsize_override = 128; + + logevent("Opened X11 forward channel"); } sfree(addrstr); } else if (typelen == 15 && !memcmp(type, "forwarded-tcpip", 15)) { struct ssh_rportfwd pf, *realpf; - char *dummy; - int dummylen; - ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */ + char *shost; + int shostlen; + ssh_pkt_getstring(pktin, &shost, &shostlen);/* skip address */ + pf.shost = dupprintf("%.*s", shostlen, NULLTOEMPTY(shost)); pf.sport = ssh_pkt_getuint32(pktin); ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen); peerport = ssh_pkt_getuint32(pktin); realpf = find234(ssh->rportfwds, &pf, NULL); - logeventf(ssh, "Received remote port %d open request " - "from %s:%d", pf.sport, peeraddr, peerport); + logeventf(ssh, "Received remote port %s:%d open request " + "from %.*s:%d", pf.shost, pf.sport, + peeraddrlen, NULLTOEMPTY(peeraddr), peerport); + sfree(pf.shost); + if (realpf == NULL) { error = "Remote port is not recognised"; } else { - const char *e = pfd_newconnect(&c->u.pfd.s, - realpf->dhost, - realpf->dport, c, - ssh->conf, - realpf->pfrec->addressfamily); + char *err; + + if (realpf->share_ctx) { + /* + * This port forwarding is on behalf of a + * connection-sharing downstream, so abandon our own + * channel-open procedure and just pass the message on + * to sshshare.c. + */ + share_got_pkt_from_server(realpf->share_ctx, pktin->type, + pktin->body, pktin->length); + sfree(c); + return; + } + + err = pfd_connect(&c->u.pfd.pf, realpf->dhost, realpf->dport, + c, ssh->conf, realpf->pfrec->addressfamily); logeventf(ssh, "Attempting to forward remote port to " "%s:%d", realpf->dhost, realpf->dport); - if (e != NULL) { - logeventf(ssh, "Port open failed: %s", e); + if (err != NULL) { + logeventf(ssh, "Port open failed: %s", err); + sfree(err); error = "Port open failed"; } else { logevent("Forwarded port opened successfully"); @@ -7401,7 +8897,8 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) error = "Agent forwarding is not enabled"; else { c->type = CHAN_AGENT; /* identify channel type */ - c->u.a.lensofar = 0; + bufchain_init(&c->u.a.inbuffer); + c->u.a.pending = NULL; } } else { error = "Unsupported channel type requested"; @@ -7419,10 +8916,13 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) logeventf(ssh, "Rejected channel open: %s", error); sfree(c); } else { - ssh2_channel_init(c); + ssh_channel_init(c); c->v.v2.remwindow = winsize; c->v.v2.remmaxpkt = pktsize; - add234(ssh->channels, c); + if (our_winsize_override) { + c->v.v2.locwindow = c->v.v2.locmaxwin = c->v.v2.remlocwin = + our_winsize_override; + } pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); ssh2_pkt_adduint32(pktout, c->remoteid); ssh2_pkt_adduint32(pktout, c->localid); @@ -7432,6 +8932,43 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin) } } +void sshfwd_x11_sharing_handover(struct ssh_channel *c, + void *share_cs, void *share_chan, + const char *peer_addr, int peer_port, + int endian, int protomajor, int protominor, + const void *initial_data, int initial_len) +{ + /* + * This function is called when we've just discovered that an X + * forwarding channel on which we'd been handling the initial auth + * ourselves turns out to be destined for a connection-sharing + * downstream. So we turn the channel into a CHAN_SHARING, meaning + * that we completely stop tracking windows and buffering data and + * just pass more or less unmodified SSH messages back and forth. + */ + c->type = CHAN_SHARING; + c->u.sharing.ctx = share_cs; + share_setup_x11_channel(share_cs, share_chan, + c->localid, c->remoteid, c->v.v2.remwindow, + c->v.v2.remmaxpkt, c->v.v2.locwindow, + peer_addr, peer_port, endian, + protomajor, protominor, + initial_data, initial_len); +} + +void sshfwd_x11_is_local(struct ssh_channel *c) +{ + /* + * This function is called when we've just discovered that an X + * forwarding channel is _not_ destined for a connection-sharing + * downstream but we're going to handle it ourselves. We stop + * presenting a cautiously small window and go into ordinary data + * exchange mode. + */ + c->u.x11.initial = FALSE; + ssh2_set_window(c, ssh_is_simple(c->ssh) ? OUR_V2_BIGWIN : OUR_V2_WINSIZE); +} + /* * Buffer banner messages for later display at some convenient point, * if we're going to display them. @@ -7450,14 +8987,13 @@ static void ssh2_msg_userauth_banner(Ssh ssh, struct Packet *pktin) } /* Helper function to deal with sending tty modes for "pty-req" */ -static void ssh2_send_ttymode(void *data, char *mode, char *val) +static void ssh2_send_ttymode(void *data, + const struct ssh_ttymode *mode, char *val) { struct Packet *pktout = (struct Packet *)data; - int i = 0; unsigned int arg = 0; - while (strcmp(mode, ssh_ttymodes[i].mode) != 0) i++; - if (i == lenof(ssh_ttymodes)) return; - switch (ssh_ttymodes[i].type) { + + switch (mode->type) { case TTY_OP_CHAR: arg = ssh_tty_parse_specchar(val); break; @@ -7465,141 +9001,128 @@ static void ssh2_send_ttymode(void *data, char *mode, char *val) arg = ssh_tty_parse_boolean(val); break; } - ssh2_pkt_addbyte(pktout, ssh_ttymodes[i].opcode); + ssh2_pkt_addbyte(pktout, mode->opcode); ssh2_pkt_adduint32(pktout, arg); } -static void ssh2_maybe_setup_x11(struct ssh_channel *c, struct Packet *pktin, - void *ctx) +static void ssh2_setup_x11(struct ssh_channel *c, struct Packet *pktin, + void *ctx) { - struct ssh2_maybe_setup_x11_state { + struct ssh2_setup_x11_state { int crLine; }; Ssh ssh = c->ssh; struct Packet *pktout; - crStateP(ssh2_maybe_setup_x11_state, ctx); + crStateP(ssh2_setup_x11_state, ctx); crBeginState; - /* - * Potentially enable X11 forwarding. - */ - if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_x11_forward) && - (ssh->x11disp = x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), - conf_get_int(ssh->conf, CONF_x11_auth), ssh->conf))) { - logevent("Requesting X11 forwarding"); - pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req", - ssh2_maybe_setup_x11, s); - ssh2_pkt_addbool(pktout, 0); /* many connections */ - ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthprotoname); - /* - * Note that while we blank the X authentication data here, we don't - * take any special action to blank the start of an X11 channel, - * so using MIT-MAGIC-COOKIE-1 and actually opening an X connection - * without having session blanking enabled is likely to leak your - * cookie into the log. - */ - dont_log_password(ssh, pktout, PKTLOG_BLANK); - ssh2_pkt_addstring(pktout, ssh->x11disp->remoteauthdatastring); - end_log_omission(ssh, pktout); - ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum); - ssh2_pkt_send(ssh, pktout); + logevent("Requesting X11 forwarding"); + pktout = ssh2_chanreq_init(ssh->mainchan, "x11-req", + ssh2_setup_x11, s); + ssh2_pkt_addbool(pktout, 0); /* many connections */ + ssh2_pkt_addstring(pktout, ssh->x11auth->protoname); + ssh2_pkt_addstring(pktout, ssh->x11auth->datastring); + ssh2_pkt_adduint32(pktout, ssh->x11disp->screennum); + ssh2_pkt_send(ssh, pktout); - crWaitUntilV(pktin); + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; - if (pktin) { - if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { - logevent("X11 forwarding enabled"); - ssh->X11_fwd_enabled = TRUE; - } else - logevent("X11 forwarding refused"); - } + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logevent("X11 forwarding enabled"); + ssh->X11_fwd_enabled = TRUE; + } else + logevent("X11 forwarding refused"); } - crFinishFreeV(s); + + crFinishFreeV; } -static void ssh2_maybe_setup_agent(struct ssh_channel *c, struct Packet *pktin, +static void ssh2_setup_agent(struct ssh_channel *c, struct Packet *pktin, void *ctx) { - struct ssh2_maybe_setup_agent_state { + struct ssh2_setup_agent_state { int crLine; }; Ssh ssh = c->ssh; struct Packet *pktout; - crStateP(ssh2_maybe_setup_agent_state, ctx); + crStateP(ssh2_setup_agent_state, ctx); crBeginState; - if (ssh->mainchan && !ssh->ncmode && conf_get_int(ssh->conf, CONF_agentfwd) && agent_exists()) { - logevent("Requesting OpenSSH-style agent forwarding"); - pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com", - ssh2_maybe_setup_agent, s); - ssh2_pkt_send(ssh, pktout); + logevent("Requesting OpenSSH-style agent forwarding"); + pktout = ssh2_chanreq_init(ssh->mainchan, "auth-agent-req@openssh.com", + ssh2_setup_agent, s); + ssh2_pkt_send(ssh, pktout); - crWaitUntilV(pktin); + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; - if (pktin) { - if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { - logevent("Agent forwarding enabled"); - ssh->agentfwd_enabled = TRUE; - } else - logevent("Agent forwarding refused"); - } + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logevent("Agent forwarding enabled"); + ssh->agentfwd_enabled = TRUE; + } else + logevent("Agent forwarding refused"); } - crFinishFreeV(s); + + crFinishFreeV; } -static void ssh2_maybe_setup_pty(struct ssh_channel *c, struct Packet *pktin, +static void ssh2_setup_pty(struct ssh_channel *c, struct Packet *pktin, void *ctx) { - struct ssh2_maybe_setup_pty_state { + struct ssh2_setup_pty_state { int crLine; }; Ssh ssh = c->ssh; struct Packet *pktout; - crStateP(ssh2_maybe_setup_pty_state, ctx); + crStateP(ssh2_setup_pty_state, ctx); crBeginState; - if (ssh->mainchan && !ssh->ncmode && !conf_get_int(ssh->conf, CONF_nopty)) { - /* Unpick the terminal-speed string. */ - /* XXX perhaps we should allow no speeds to be sent. */ - ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ - sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); - /* Build the pty request. */ - pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req", - ssh2_maybe_setup_pty, s); - ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype)); - ssh2_pkt_adduint32(pktout, ssh->term_width); - ssh2_pkt_adduint32(pktout, ssh->term_height); - ssh2_pkt_adduint32(pktout, 0); /* pixel width */ - ssh2_pkt_adduint32(pktout, 0); /* pixel height */ - ssh2_pkt_addstring_start(pktout); - parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout); - ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED); - ssh2_pkt_adduint32(pktout, ssh->ispeed); - ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED); - ssh2_pkt_adduint32(pktout, ssh->ospeed); - ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */ - ssh2_pkt_send(ssh, pktout); - ssh->state = SSH_STATE_INTERMED; - - crWaitUntilV(pktin); + /* Unpick the terminal-speed string. */ + /* XXX perhaps we should allow no speeds to be sent. */ + ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */ + sscanf(conf_get_str(ssh->conf, CONF_termspeed), "%d,%d", &ssh->ospeed, &ssh->ispeed); + /* Build the pty request. */ + pktout = ssh2_chanreq_init(ssh->mainchan, "pty-req", + ssh2_setup_pty, s); + ssh2_pkt_addstring(pktout, conf_get_str(ssh->conf, CONF_termtype)); + ssh2_pkt_adduint32(pktout, ssh->term_width); + ssh2_pkt_adduint32(pktout, ssh->term_height); + ssh2_pkt_adduint32(pktout, 0); /* pixel width */ + ssh2_pkt_adduint32(pktout, 0); /* pixel height */ + ssh2_pkt_addstring_start(pktout); + parse_ttymodes(ssh, ssh2_send_ttymode, (void *)pktout); + ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_ISPEED); + ssh2_pkt_adduint32(pktout, ssh->ispeed); + ssh2_pkt_addbyte(pktout, SSH2_TTY_OP_OSPEED); + ssh2_pkt_adduint32(pktout, ssh->ospeed); + ssh2_pkt_addstring_data(pktout, "\0", 1); /* TTY_OP_END */ + ssh2_pkt_send(ssh, pktout); + ssh->state = SSH_STATE_INTERMED; + + /* Wait to be called back with either a response packet, or NULL + * meaning clean up and free our data */ + crReturnV; - if (pktin) { - if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { - logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", - ssh->ospeed, ssh->ispeed); - ssh->got_pty = TRUE; - } else { - c_write_str(ssh, "Server refused to allocate pty\r\n"); - ssh->editing = ssh->echoing = 1; - } - } - } else { - ssh->editing = ssh->echoing = 1; + if (pktin) { + if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) { + logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)", + ssh->ospeed, ssh->ispeed); + ssh->got_pty = TRUE; + } else { + c_write_str(ssh, "Server refused to allocate pty\r\n"); + ssh->editing = ssh->echoing = 1; + } } - crFinishFreeV(s); + + crFinishFreeV; } static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin, @@ -7622,7 +9145,7 @@ static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin, * then wait for a whole bunch of successes or failures. */ s->num_env = 0; - if (ssh->mainchan && !ssh->ncmode) { + { char *key, *val; for (val = conf_get_str_strs(ssh->conf, CONF_environmt, NULL, &key); @@ -7644,7 +9167,9 @@ static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin, s->env_left = s->num_env; while (s->env_left > 0) { - crWaitUntilV(pktin); + /* Wait to be called back with either a response packet, + * or NULL meaning clean up and free our data */ + crReturnV; if (!pktin) goto out; if (pktin->type == SSH2_MSG_CHANNEL_SUCCESS) s->env_ok++; @@ -7663,7 +9188,7 @@ static void ssh2_setup_env(struct ssh_channel *c, struct Packet *pktin, } } out:; - crFinishFreeV(s); + crFinishFreeV; } /* @@ -7677,10 +9202,11 @@ static void ssh2_msg_authconn(Ssh ssh, struct Packet *pktin) static void ssh2_response_authconn(struct ssh_channel *c, struct Packet *pktin, void *ctx) { - do_ssh2_authconn(c->ssh, NULL, 0, pktin); + if (pktin) + do_ssh2_authconn(c->ssh, NULL, 0, pktin); } -static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, +static void do_ssh2_authconn(Ssh ssh, const unsigned char *in, int inlen, struct Packet *pktin) { struct do_ssh2_authconn_state { @@ -7711,7 +9237,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int got_username; void *publickey_blob; int publickey_bloblen; - int publickey_encrypted; + int privatekey_available, privatekey_encrypted; char *publickey_algorithm; char *publickey_comment; unsigned char agent_request[5], *agent_response, *agentp; @@ -7722,7 +9248,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int pklen, alglen, commentlen; int siglen, retlen, len; char *q, *agentreq, *ret; - int try_send; struct Packet *pktout; Filename *keyfile; #ifndef NO_GSSAPI @@ -7762,35 +9287,40 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->done_service_req = FALSE; s->we_are_in = s->userauth_success = FALSE; + s->agent_response = NULL; #ifndef NO_GSSAPI s->tried_gssapi = FALSE; #endif - if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) { - /* - * Request userauth protocol, and await a response to it. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); - ssh2_pkt_addstring(s->pktout, "ssh-userauth"); - ssh2_pkt_send(ssh, s->pktout); - crWaitUntilV(pktin); - if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) - s->done_service_req = TRUE; - } - if (!s->done_service_req) { - /* - * Request connection protocol directly, without authentication. - */ - s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); - ssh2_pkt_addstring(s->pktout, "ssh-connection"); - ssh2_pkt_send(ssh, s->pktout); - crWaitUntilV(pktin); - if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) { - s->we_are_in = TRUE; /* no auth required */ - } else { - bombout(("Server refused service request")); - crStopV; - } + if (!ssh->bare_connection) { + if (!conf_get_int(ssh->conf, CONF_ssh_no_userauth)) { + /* + * Request userauth protocol, and await a response to it. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring(s->pktout, "ssh-userauth"); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) + s->done_service_req = TRUE; + } + if (!s->done_service_req) { + /* + * Request connection protocol directly, without authentication. + */ + s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST); + ssh2_pkt_addstring(s->pktout, "ssh-connection"); + ssh2_pkt_send(ssh, s->pktout); + crWaitUntilV(pktin); + if (pktin->type == SSH2_MSG_SERVICE_ACCEPT) { + s->we_are_in = TRUE; /* no auth required */ + } else { + bombout(("Server refused service request")); + crStopV; + } + } + } else { + s->we_are_in = TRUE; } /* Arrange to be able to deal with any BANNERs that come in. @@ -7812,10 +9342,12 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->keyfile = conf_get_filename(ssh->conf, CONF_keyfile); if (!filename_is_null(s->keyfile)) { int keytype; - logeventf(ssh, "Reading private key file \"%.150s\"", + logeventf(ssh, "Reading key file \"%.150s\"", filename_to_str(s->keyfile)); keytype = key_type(s->keyfile); - if (keytype == SSH_KEYTYPE_SSH2) { + if (keytype == SSH_KEYTYPE_SSH2 || + keytype == SSH_KEYTYPE_SSH2_PUBLIC_RFC4716 || + keytype == SSH_KEYTYPE_SSH2_PUBLIC_OPENSSH) { const char *error; s->publickey_blob = ssh2_userkey_loadpub(s->keyfile, @@ -7823,13 +9355,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, &s->publickey_bloblen, &s->publickey_comment, &error); if (s->publickey_blob) { - s->publickey_encrypted = + s->privatekey_available = (keytype == SSH_KEYTYPE_SSH2); + if (!s->privatekey_available) + logeventf(ssh, "Key file contains public key only"); + s->privatekey_encrypted = ssh2_userkey_encrypted(s->keyfile, NULL); } else { char *msgbuf; - logeventf(ssh, "Unable to load private key (%s)", + logeventf(ssh, "Unable to load key (%s)", error); - msgbuf = dupprintf("Unable to load private key file " + msgbuf = dupprintf("Unable to load key file " "\"%.150s\" (%s)\r\n", filename_to_str(s->keyfile), error); @@ -7866,8 +9401,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* Request the keys held by the agent. */ PUT_32BIT(s->agent_request, 1); s->agent_request[4] = SSH2_AGENTC_REQUEST_IDENTITIES; - if (!agent_query(s->agent_request, 5, &r, &s->agent_responselen, - ssh_agent_callback, ssh)) { + ssh->auth_agent_query = agent_query( + s->agent_request, 5, &r, &s->agent_responselen, + ssh_agent_callback, ssh); + if (ssh->auth_agent_query) { do { crReturnV; if (pktin) { @@ -7885,13 +9422,53 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int keyi; unsigned char *p; p = s->agent_response + 5; - s->nkeys = GET_32BIT(p); + s->nkeys = toint(GET_32BIT(p)); + + /* + * Vet the Pageant response to ensure that the key + * count and blob lengths make sense. + */ + if (s->nkeys < 0) { + logeventf(ssh, "Pageant response contained a negative" + " key count %d", s->nkeys); + s->nkeys = 0; + goto done_agent_query; + } else { + unsigned char *q = p + 4; + int lenleft = s->agent_responselen - 5 - 4; + + for (keyi = 0; keyi < s->nkeys; keyi++) { + int bloblen, commentlen; + if (lenleft < 4) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + bloblen = toint(GET_32BIT(q)); + if (bloblen < 0 || bloblen > lenleft) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + lenleft -= 4 + bloblen; + q += 4 + bloblen; + commentlen = toint(GET_32BIT(q)); + if (commentlen < 0 || commentlen > lenleft) { + logeventf(ssh, "Pageant response was truncated"); + s->nkeys = 0; + goto done_agent_query; + } + lenleft -= 4 + commentlen; + q += 4 + commentlen; + } + } + p += 4; logeventf(ssh, "Pageant has %d SSH-2 keys", s->nkeys); if (s->publickey_blob) { /* See if configured key is in agent. */ for (keyi = 0; keyi < s->nkeys; keyi++) { - s->pklen = GET_32BIT(p); + s->pklen = toint(GET_32BIT(p)); if (s->pklen == s->publickey_bloblen && !memcmp(p+4, s->publickey_blob, s->publickey_bloblen)) { @@ -7902,7 +9479,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, break; } p += 4 + s->pklen; - p += GET_32BIT(p) + 4; /* comment */ + p += toint(GET_32BIT(p)) + 4; /* comment */ } if (!s->pkblob_in_agent) { logevent("Configured key file not in Pageant"); @@ -7912,6 +9489,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } else { logevent("Failed to get reply from Pageant"); } + done_agent_query:; } } @@ -8142,11 +9720,20 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->can_keyb_inter = conf_get_int(ssh->conf, CONF_try_ki_auth) && in_commasep_string("keyboard-interactive", methods, methlen); #ifndef NO_GSSAPI - if (!ssh->gsslibs) - ssh->gsslibs = ssh_gss_setup(ssh->conf); - s->can_gssapi = conf_get_int(ssh->conf, CONF_try_gssapi_auth) && - in_commasep_string("gssapi-with-mic", methods, methlen) && - ssh->gsslibs->nlibraries > 0; + if (conf_get_int(ssh->conf, CONF_try_gssapi_auth) && + in_commasep_string("gssapi-with-mic", methods, methlen)) { + /* Try loading the GSS libraries and see if we + * have any. */ + if (!ssh->gsslibs) + ssh->gsslibs = ssh_gss_setup(ssh->conf); + s->can_gssapi = (ssh->gsslibs->nlibraries > 0); + } else { + /* No point in even bothering to try to load the + * GSS libraries, if the user configuration and + * server aren't both prepared to attempt GSSAPI + * auth in the first place. */ + s->can_gssapi = FALSE; + } #endif } @@ -8163,13 +9750,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, logeventf(ssh, "Trying Pageant key #%d", s->keyi); /* Unpack key from agent response */ - s->pklen = GET_32BIT(s->agentp); + s->pklen = toint(GET_32BIT(s->agentp)); s->agentp += 4; s->pkblob = (char *)s->agentp; s->agentp += s->pklen; - s->alglen = GET_32BIT(s->pkblob); + s->alglen = toint(GET_32BIT(s->pkblob)); s->alg = s->pkblob + 4; - s->commentlen = GET_32BIT(s->agentp); + s->commentlen = toint(GET_32BIT(s->agentp)); s->agentp += 4; s->commentp = (char *)s->agentp; s->agentp += s->commentlen; @@ -8255,9 +9842,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->q += s->pktout->length - 5; /* And finally the (zero) flags word. */ PUT_32BIT(s->q, 0); - if (!agent_query(s->agentreq, s->len + 4, - &vret, &s->retlen, - ssh_agent_callback, ssh)) { + ssh->auth_agent_query = agent_query( + s->agentreq, s->len + 4, &vret, &s->retlen, + ssh_agent_callback, ssh); + if (ssh->auth_agent_query) { do { crReturnV; if (pktin) { @@ -8273,7 +9861,9 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->ret = vret; sfree(s->agentreq); if (s->ret) { - if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) { + if (s->retlen >= 9 && + s->ret[4] == SSH2_AGENT_SIGN_RESPONSE && + GET_32BIT(s->ret + 5) <= (unsigned)(s->retlen-9)) { logevent("Sending Pageant's response"); ssh2_add_sigblob(ssh, s->pktout, s->pkblob, s->pklen, @@ -8300,7 +9890,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, } } else if (s->can_pubkey && s->publickey_blob && - !s->tried_pubkey_config) { + s->privatekey_available && !s->tried_pubkey_config) { struct ssh2_userkey *key; /* not live over crReturn */ char *passphrase; /* not live over crReturn */ @@ -8351,7 +9941,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, key = NULL; while (!key) { const char *error; /* not live over crReturn */ - if (s->publickey_encrypted) { + if (s->privatekey_encrypted) { /* * Get a passphrase from the user. */ @@ -8475,6 +10065,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, logevent("Sent public key signature"); s->type = AUTH_TYPE_PUBLICKEY; key->alg->freekey(key->data); + sfree(key->comment); + sfree(key); } #ifndef NO_GSSAPI @@ -8803,10 +10395,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE); ssh2_pkt_adduint32(s->pktout, s->num_prompts); for (i=0; i < s->num_prompts; i++) { - dont_log_password(ssh, s->pktout, PKTLOG_BLANK); ssh2_pkt_addstring(s->pktout, s->cur_prompt->prompts[i]->result); - end_log_omission(ssh, s->pktout); } ssh2_pkt_send_with_padding(ssh, s->pktout, 256); @@ -8889,9 +10479,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* service requested */ ssh2_pkt_addstring(s->pktout, "password"); ssh2_pkt_addbool(s->pktout, FALSE); - dont_log_password(ssh, s->pktout, PKTLOG_BLANK); ssh2_pkt_addstring(s->pktout, s->password); - end_log_omission(ssh, s->pktout); ssh2_pkt_send_with_padding(ssh, s->pktout, 256); logevent("Sent password"); s->type = AUTH_TYPE_PASSWORD; @@ -8916,7 +10504,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int prompt_len; /* not live over crReturn */ { - char *msg; + const char *msg; if (changereq_first_time) msg = "Server requested password change"; else @@ -8932,7 +10520,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, s->cur_prompt->to_server = TRUE; s->cur_prompt->name = dupstr("New SSH password"); s->cur_prompt->instruction = - dupprintf("%.*s", prompt_len, prompt); + dupprintf("%.*s", prompt_len, NULLTOEMPTY(prompt)); s->cur_prompt->instr_reqd = TRUE; /* * There's no explicit requirement in the protocol @@ -9018,12 +10606,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* service requested */ ssh2_pkt_addstring(s->pktout, "password"); ssh2_pkt_addbool(s->pktout, TRUE); - dont_log_password(ssh, s->pktout, PKTLOG_BLANK); ssh2_pkt_addstring(s->pktout, s->password); ssh2_pkt_addstring(s->pktout, s->cur_prompt->prompts[1]->result); free_prompts(s->cur_prompt); - end_log_omission(ssh, s->pktout); ssh2_pkt_send_with_padding(ssh, s->pktout, 256); logevent("Sent new password"); @@ -9080,13 +10666,14 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* Clear up various bits and pieces from authentication. */ if (s->publickey_blob) { + sfree(s->publickey_algorithm); sfree(s->publickey_blob); sfree(s->publickey_comment); } if (s->agent_response) sfree(s->agent_response); - if (s->userauth_success) { + if (s->userauth_success && !ssh->bare_connection) { /* * We've just received USERAUTH_SUCCESS, and we haven't sent any * packets since. Signal the transport layer to consider enacting @@ -9100,10 +10687,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, do_ssh2_transport(ssh, "enabling delayed compression", -2, NULL); } - /* - * Now the connection protocol has started, one way or another. - */ - ssh->channels = newtree234(ssh_channelcmp); /* @@ -9120,66 +10703,30 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ if (conf_get_int(ssh->conf, CONF_ssh_no_shell)) { ssh->mainchan = NULL; - } else if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) { - /* - * Just start a direct-tcpip channel and use it as the main - * channel. - */ + } else { ssh->mainchan = snew(struct ssh_channel); ssh->mainchan->ssh = ssh; - ssh2_channel_init(ssh->mainchan); - logeventf(ssh, - "Opening direct-tcpip channel to %s:%d in place of session", - conf_get_str(ssh->conf, CONF_ssh_nc_host), - conf_get_int(ssh->conf, CONF_ssh_nc_port)); - s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); - ssh2_pkt_addstring(s->pktout, "direct-tcpip"); - ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); - ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ - ssh2_pkt_addstring(s->pktout, conf_get_str(ssh->conf, CONF_ssh_nc_host)); - ssh2_pkt_adduint32(s->pktout, conf_get_int(ssh->conf, CONF_ssh_nc_port)); - /* - * There's nothing meaningful to put in the originator - * fields, but some servers insist on syntactically correct - * information. - */ - ssh2_pkt_addstring(s->pktout, "0.0.0.0"); - ssh2_pkt_adduint32(s->pktout, 0); - ssh2_pkt_send(ssh, s->pktout); + ssh_channel_init(ssh->mainchan); - crWaitUntilV(pktin); - if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { - bombout(("Server refused to open a direct-tcpip channel")); - crStopV; - /* FIXME: error data comes back in FAILURE packet */ - } - if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) { - bombout(("Server's channel confirmation cited wrong channel")); - crStopV; + if (*conf_get_str(ssh->conf, CONF_ssh_nc_host)) { + /* + * Just start a direct-tcpip channel and use it as the main + * channel. + */ + ssh_send_port_open(ssh->mainchan, + conf_get_str(ssh->conf, CONF_ssh_nc_host), + conf_get_int(ssh->conf, CONF_ssh_nc_port), + "main channel"); + ssh->ncmode = TRUE; + } else { + s->pktout = ssh2_chanopen_init(ssh->mainchan, "session"); + logevent("Opening session as main channel"); + ssh2_pkt_send(ssh, s->pktout); + ssh->ncmode = FALSE; } - ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin); - ssh->mainchan->halfopen = FALSE; - ssh->mainchan->type = CHAN_MAINSESSION; - ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); - ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); - add234(ssh->channels, ssh->mainchan); - update_specials_menu(ssh->frontend); - logevent("Opened direct-tcpip channel"); - ssh->ncmode = TRUE; - } else { - ssh->mainchan = snew(struct ssh_channel); - ssh->mainchan->ssh = ssh; - ssh2_channel_init(ssh->mainchan); - s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); - ssh2_pkt_addstring(s->pktout, "session"); - ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid); - ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT); /* our max pkt size */ - ssh2_pkt_send(ssh, s->pktout); crWaitUntilV(pktin); if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) { - bombout(("Server refused to open a session")); + bombout(("Server refused to open channel")); crStopV; /* FIXME: error data comes back in FAILURE packet */ } @@ -9192,10 +10739,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh->mainchan->type = CHAN_MAINSESSION; ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin); ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin); - add234(ssh->channels, ssh->mainchan); update_specials_menu(ssh->frontend); - logevent("Opened channel for session"); - ssh->ncmode = FALSE; + logevent("Opened main channel"); } /* @@ -9218,8 +10763,15 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response; ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response; + /* + * Now the connection protocol is properly up and running, with + * all those dispatch table entries, so it's safe to let + * downstreams start trying to open extra channels through us. + */ + if (ssh->connshare) + share_activate(ssh->connshare, ssh->v_s); - if (ssh->mainchan && conf_get_int(ssh->conf, CONF_ssh_simple)) { + if (ssh->mainchan && ssh_is_simple(ssh)) { /* * This message indicates to the server that we promise * not to try to run any other channel in parallel with @@ -9237,88 +10789,102 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, */ ssh_setup_portfwd(ssh, ssh->conf); - /* - * Send the CHANNEL_REQUESTS for the main channel. Each one is - * handled by its own little asynchronous co-routine. - */ + if (ssh->mainchan && !ssh->ncmode) { + /* + * Send the CHANNEL_REQUESTS for the main session channel. + * Each one is handled by its own little asynchronous + * co-routine. + */ - /* - * Potentially enable X11 forwarding. - */ - ssh2_maybe_setup_x11(ssh->mainchan, NULL, NULL); + /* Potentially enable X11 forwarding. */ + if (conf_get_int(ssh->conf, CONF_x11_forward)) { + ssh->x11disp = + x11_setup_display(conf_get_str(ssh->conf, CONF_x11_display), + ssh->conf); + if (!ssh->x11disp) { + /* FIXME: return an error message from x11_setup_display */ + logevent("X11 forwarding not enabled: unable to" + " initialise X display"); + } else { + ssh->x11auth = x11_invent_fake_auth + (ssh->x11authtree, conf_get_int(ssh->conf, CONF_x11_auth)); + ssh->x11auth->disp = ssh->x11disp; + + ssh2_setup_x11(ssh->mainchan, NULL, NULL); + } + } - /* - * Potentially enable agent forwarding. - */ - ssh2_maybe_setup_agent(ssh->mainchan, NULL, NULL); + /* Potentially enable agent forwarding. */ + if (ssh_agent_forwarding_permitted(ssh)) + ssh2_setup_agent(ssh->mainchan, NULL, NULL); - /* - * Now allocate a pty for the session. - */ - ssh2_maybe_setup_pty(ssh->mainchan, NULL, NULL); + /* Now allocate a pty for the session. */ + if (!conf_get_int(ssh->conf, CONF_nopty)) + ssh2_setup_pty(ssh->mainchan, NULL, NULL); - /* - * Send environment variables. - */ - ssh2_setup_env(ssh->mainchan, NULL, NULL); + /* Send environment variables. */ + ssh2_setup_env(ssh->mainchan, NULL, NULL); - /* - * Start a shell or a remote command. We may have to attempt - * this twice if the config data has provided a second choice - * of command. - */ - if (ssh->mainchan && !ssh->ncmode) while (1) { - int subsys; - char *cmd; + /* + * Start a shell or a remote command. We may have to attempt + * this twice if the config data has provided a second choice + * of command. + */ + while (1) { + int subsys; + char *cmd; - if (ssh->fallback_cmd) { - subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2); - cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); - } else { - subsys = conf_get_int(ssh->conf, CONF_ssh_subsys); - cmd = conf_get_str(ssh->conf, CONF_remote_cmd); - } + if (ssh->fallback_cmd) { + subsys = conf_get_int(ssh->conf, CONF_ssh_subsys2); + cmd = conf_get_str(ssh->conf, CONF_remote_cmd2); + } else { + subsys = conf_get_int(ssh->conf, CONF_ssh_subsys); + cmd = conf_get_str(ssh->conf, CONF_remote_cmd); + } - if (subsys) { - s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem", - ssh2_response_authconn, NULL); - ssh2_pkt_addstring(s->pktout, cmd); - } else if (*cmd) { - s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec", - ssh2_response_authconn, NULL); - ssh2_pkt_addstring(s->pktout, cmd); - } else { - s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell", - ssh2_response_authconn, NULL); - } - ssh2_pkt_send(ssh, s->pktout); + if (subsys) { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "subsystem", + ssh2_response_authconn, NULL); + ssh2_pkt_addstring(s->pktout, cmd); + } else if (*cmd) { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "exec", + ssh2_response_authconn, NULL); + ssh2_pkt_addstring(s->pktout, cmd); + } else { + s->pktout = ssh2_chanreq_init(ssh->mainchan, "shell", + ssh2_response_authconn, NULL); + } + ssh2_pkt_send(ssh, s->pktout); - crWaitUntilV(pktin); + crWaitUntilV(pktin); - if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { - if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { - bombout(("Unexpected response to shell/command request:" - " packet type %d", pktin->type)); + if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) { + if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) { + bombout(("Unexpected response to shell/command request:" + " packet type %d", pktin->type)); + crStopV; + } + /* + * We failed to start the command. If this is the + * fallback command, we really are finished; if it's + * not, and if the fallback command exists, try falling + * back to it before complaining. + */ + if (!ssh->fallback_cmd && + *conf_get_str(ssh->conf, CONF_remote_cmd2)) { + logevent("Primary command failed; attempting fallback"); + ssh->fallback_cmd = TRUE; + continue; + } + bombout(("Server refused to start a shell/command")); crStopV; + } else { + logevent("Started a shell/command"); } - /* - * We failed to start the command. If this is the - * fallback command, we really are finished; if it's - * not, and if the fallback command exists, try falling - * back to it before complaining. - */ - if (!ssh->fallback_cmd && - *conf_get_str(ssh->conf, CONF_remote_cmd2)) { - logevent("Primary command failed; attempting fallback"); - ssh->fallback_cmd = TRUE; - continue; - } - bombout(("Server refused to start a shell/command")); - crStopV; - } else { - logevent("Started a shell/command"); + break; } - break; + } else { + ssh->editing = ssh->echoing = TRUE; } ssh->state = SSH_STATE_SESSION; @@ -9327,23 +10893,15 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, if (ssh->eof_needed) ssh_special(ssh, TS_EOF); - /* - * All the initial channel requests are done, so install the default - * response handler. - */ - ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_channel_response; - ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_channel_response; - /* * Transfer data! */ if (ssh->ldisc) - ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */ + ldisc_echoedit_update(ssh->ldisc); /* cause ldisc to notice changes */ if (ssh->mainchan) ssh->send_ok = 1; while (1) { crReturnV; - s->try_send = FALSE; if (pktin) { /* @@ -9358,17 +10916,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, /* * We have spare data. Add it to the channel buffer. */ - ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen); - s->try_send = TRUE; - } - if (s->try_send) { - int i; - struct ssh_channel *c; - /* - * Try to send data on all channels if we can. - */ - for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) - ssh2_try_send_and_unthrottle(ssh, c); + ssh_send_channel_data(ssh->mainchan, (char *)in, inlen); } } @@ -9397,13 +10945,13 @@ static void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin) logevent(buf); sfree(buf); buf = dupprintf("Disconnection message text: %.*s", - msglen, msg); + msglen, NULLTOEMPTY(msg)); logevent(buf); bombout(("Server sent disconnect message\ntype %d (%s):\n\"%.*s\"", reason, (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ? ssh2_disconnect_reasons[reason] : "unknown", - msglen, msg)); + msglen, NULLTOEMPTY(msg))); sfree(buf); } @@ -9417,7 +10965,7 @@ static void ssh2_msg_debug(Ssh ssh, struct Packet *pktin) ssh2_pkt_getbool(pktin); ssh_pkt_getstring(pktin, &msg, &msglen); - logeventf(ssh, "Remote debug message: %.*s", msglen, msg); + logeventf(ssh, "Remote debug message: %.*s", msglen, NULLTOEMPTY(msg)); } static void ssh2_msg_transport(Ssh ssh, struct Packet *pktin) @@ -9512,23 +11060,66 @@ static void ssh2_protocol_setup(Ssh ssh) ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; } -static void ssh2_timer(void *ctx, long now) +static void ssh2_bare_connection_protocol_setup(Ssh ssh) +{ + int i; + + /* + * Most messages cause SSH2_MSG_UNIMPLEMENTED. + */ + for (i = 0; i < 256; i++) + ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented; + + /* + * Initially, we set all ssh-connection messages to 'unexpected'; + * do_ssh2_authconn will fill things in properly. We also handle a + * couple of messages from the transport protocol which aren't + * related to key exchange (UNIMPLEMENTED, IGNORE, DEBUG, + * DISCONNECT). + */ + ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = ssh2_msg_unexpected; + ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = ssh2_msg_unexpected; + + ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = ssh2_msg_unexpected; + + /* + * These messages have a special handler from the start. + */ + ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect; + ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; + ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug; +} + +static void ssh2_timer(void *ctx, unsigned long now) { Ssh ssh = (Ssh)ctx; if (ssh->state == SSH_STATE_CLOSED) return; - if (!ssh->kex_in_progress && conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 && - now - ssh->next_rekey >= 0) { + if (!ssh->kex_in_progress && !ssh->bare_connection && + conf_get_int(ssh->conf, CONF_ssh_rekey_time) != 0 && + now == ssh->next_rekey) { do_ssh2_transport(ssh, "timeout", -1, NULL); } } -static void ssh2_protocol(Ssh ssh, void *vin, int inlen, +static void ssh2_protocol(Ssh ssh, const void *vin, int inlen, struct Packet *pktin) { - unsigned char *in = (unsigned char *)vin; + const unsigned char *in = (const unsigned char *)vin; if (ssh->state == SSH_STATE_CLOSED) return; @@ -9548,6 +11139,19 @@ static void ssh2_protocol(Ssh ssh, void *vin, int inlen, do_ssh2_authconn(ssh, in, inlen, pktin); } +static void ssh2_bare_connection_protocol(Ssh ssh, const void *vin, int inlen, + struct Packet *pktin) +{ + const unsigned char *in = (const unsigned char *)vin; + if (ssh->state == SSH_STATE_CLOSED) + return; + + if (pktin) + ssh->packet_dispatch[pktin->type](ssh, pktin); + else + do_ssh2_authconn(ssh, in, inlen, pktin); +} + static void ssh_cache_conf_values(Ssh ssh) { ssh->logomitdata = conf_get_int(ssh->conf, CONF_logomitdata); @@ -9559,7 +11163,8 @@ static void ssh_cache_conf_values(Ssh ssh) * Returns an error message, or NULL on success. */ static const char *ssh_init(void *frontend_handle, void **backend_handle, - Conf *conf, char *host, int port, char **realhost, + Conf *conf, + const char *host, int port, char **realhost, int nodelay, int keepalive) { const char *p; @@ -9588,6 +11193,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->kex = NULL; ssh->kex_ctx = NULL; ssh->hostkey = NULL; + ssh->hostkey_str = NULL; ssh->exitcode = -1; ssh->close_expected = FALSE; ssh->clean_exit = FALSE; @@ -9603,13 +11209,17 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->pkt_kctx = SSH2_PKTCTX_NOKEX; ssh->pkt_actx = SSH2_PKTCTX_NOAUTH; ssh->x11disp = NULL; + ssh->x11auth = NULL; + ssh->x11authtree = newtree234(x11_authcmp); ssh->v1_compressing = FALSE; ssh->v2_outgoing_sequence = 0; ssh->ssh1_rdpkt_crstate = 0; ssh->ssh2_rdpkt_crstate = 0; + ssh->ssh2_bare_rdpkt_crstate = 0; ssh->ssh_gotdata_crstate = 0; ssh->do_ssh1_connection_crstate = 0; ssh->do_ssh_init_state = NULL; + ssh->do_ssh_connection_init_state = NULL; ssh->do_ssh1_login_state = NULL; ssh->do_ssh2_transport_state = NULL; ssh->do_ssh2_authconn_state = NULL; @@ -9628,6 +11238,14 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, ssh->username = NULL; ssh->sent_console_eof = FALSE; ssh->got_pty = FALSE; + ssh->bare_connection = FALSE; + ssh->X11_fwd_enabled = FALSE; + ssh->connshare = NULL; + ssh->attempting_connshare = FALSE; + ssh->session_started = FALSE; + ssh->specials = NULL; + ssh->n_uncert_hostkeys = 0; + ssh->cross_certifying = FALSE; *backend_handle = ssh; @@ -9663,15 +11281,19 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle, CONF_ssh_rekey_data)); ssh->kex_in_progress = FALSE; + ssh->auth_agent_query = NULL; + #ifndef NO_GSSAPI ssh->gsslibs = NULL; #endif + random_ref(); /* do this now - may be needed by sharing setup code */ + p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive); - if (p != NULL) + if (p != NULL) { + random_unref(); return p; - - random_ref(); + } return NULL; } @@ -9681,6 +11303,7 @@ static void ssh_free(void *handle) Ssh ssh = (Ssh) handle; struct ssh_channel *c; struct ssh_rportfwd *pf; + struct X11FakeAuth *auth; if (ssh->v1_cipher_ctx) ssh->cipher->free_context(ssh->v1_cipher_ctx); @@ -9715,23 +11338,13 @@ static void ssh_free(void *handle) while (ssh->qhead) { struct queued_handler *qh = ssh->qhead; ssh->qhead = qh->next; - sfree(ssh->qhead); + sfree(qh); } ssh->qhead = ssh->qtail = NULL; if (ssh->channels) { while ((c = delpos234(ssh->channels, 0)) != NULL) { - switch (c->type) { - case CHAN_X11: - if (c->u.x11.s != NULL) - x11_close(c->u.x11.s); - break; - case CHAN_SOCKDATA: - case CHAN_SOCKDATA_DORMANT: - if (c->u.pfd.s != NULL) - pfd_close(c->u.pfd.s); - break; - } + ssh_channel_close_local(c, NULL); if (ssh->version == 2) { struct outstanding_channel_request *ocr, *nocr; ocr = c->v.v2.chanreq_head; @@ -9749,6 +11362,9 @@ static void ssh_free(void *handle) ssh->channels = NULL; } + if (ssh->connshare) + sharestate_free(ssh->connshare); + if (ssh->rportfwds) { while ((pf = delpos234(ssh->rportfwds, 0)) != NULL) free_rportfwd(pf); @@ -9758,6 +11374,9 @@ static void ssh_free(void *handle) sfree(ssh->deferred_send_data); if (ssh->x11disp) x11_free_display(ssh->x11disp); + while ((auth = delpos234(ssh->x11authtree, 0)) != NULL) + x11_free_fake_auth(auth); + freetree234(ssh->x11authtree); sfree(ssh->do_ssh_init_state); sfree(ssh->do_ssh1_login_state); sfree(ssh->do_ssh2_transport_state); @@ -9765,6 +11384,8 @@ static void ssh_free(void *handle) sfree(ssh->v_c); sfree(ssh->v_s); sfree(ssh->fullhostname); + sfree(ssh->hostkey_str); + sfree(ssh->specials); if (ssh->crcda_ctx) { crcda_free_context(ssh->crcda_ctx); ssh->crcda_ctx = NULL; @@ -9777,6 +11398,10 @@ static void ssh_free(void *handle) bufchain_clear(&ssh->queued_incoming_data); sfree(ssh->username); conf_free(ssh->conf); + + if (ssh->auth_agent_query) + agent_cancel_query(ssh->auth_agent_query); + #ifndef NO_GSSAPI if (ssh->gsslibs) ssh_gss_cleanup(ssh->gsslibs); @@ -9792,7 +11417,8 @@ static void ssh_free(void *handle) static void ssh_reconfig(void *handle, Conf *conf) { Ssh ssh = (Ssh) handle; - char *rekeying = NULL, rekey_mandatory = FALSE; + const char *rekeying = NULL; + int rekey_mandatory = FALSE; unsigned long old_max_data_size; int i, rekey_time; @@ -9803,10 +11429,10 @@ static void ssh_reconfig(void *handle, Conf *conf) rekey_time = conf_get_int(conf, CONF_ssh_rekey_time); if (conf_get_int(ssh->conf, CONF_ssh_rekey_time) != rekey_time && rekey_time != 0) { - long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC; - long now = GETTICKCOUNT(); + unsigned long new_next = ssh->last_rekey + rekey_time*60*TICKSPERSEC; + unsigned long now = GETTICKCOUNT(); - if (new_next - now < 0) { + if (now - ssh->last_rekey > rekey_time*60*TICKSPERSEC) { rekeying = "timeout shortened"; } else { ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh); @@ -9845,7 +11471,7 @@ static void ssh_reconfig(void *handle, Conf *conf) ssh->conf = conf_copy(conf); ssh_cache_conf_values(ssh); - if (rekeying) { + if (!ssh->bare_connection && rekeying) { if (!ssh->kex_in_progress) { do_ssh2_transport(ssh, rekeying, -1, NULL); } else if (rekey_mandatory) { @@ -9857,14 +11483,14 @@ static void ssh_reconfig(void *handle, Conf *conf) /* * Called to send data down the SSH connection. */ -static int ssh_send(void *handle, char *buf, int len) +static int ssh_send(void *handle, const char *buf, int len) { Ssh ssh = (Ssh) handle; if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL) return 0; - ssh->protocol(ssh, (unsigned char *)buf, len, 0); + ssh->protocol(ssh, (const unsigned char *)buf, len, 0); return ssh_sendbuffer(ssh); } @@ -9977,19 +11603,24 @@ static const struct telnet_special *ssh_get_specials(void *handle) static const struct telnet_special specials_end[] = { {NULL, TS_EXITMENU} }; - /* XXX review this length for any changes: */ - static struct telnet_special ssh_specials[lenof(ssh2_ignore_special) + - lenof(ssh2_rekey_special) + - lenof(ssh2_session_specials) + - lenof(specials_end)]; + + struct telnet_special *specials = NULL; + int nspecials = 0, specialsize = 0; + Ssh ssh = (Ssh) handle; - int i = 0; -#define ADD_SPECIALS(name) \ - do { \ - assert((i + lenof(name)) <= lenof(ssh_specials)); \ - memcpy(&ssh_specials[i], name, sizeof name); \ - i += lenof(name); \ - } while(0) + + sfree(ssh->specials); + +#define ADD_SPECIALS(name) do \ + { \ + int len = lenof(name); \ + if (nspecials + len > specialsize) { \ + specialsize = (nspecials + len) * 5 / 4 + 32; \ + specials = sresize(specials, specialsize, struct telnet_special); \ + } \ + memcpy(specials+nspecials, name, len*sizeof(struct telnet_special)); \ + nspecials += len; \ + } while (0) if (ssh->version == 1) { /* Don't bother offering IGNORE if we've decided the remote @@ -10000,15 +11631,41 @@ static const struct telnet_special *ssh_get_specials(void *handle) } else if (ssh->version == 2) { if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) ADD_SPECIALS(ssh2_ignore_special); - if (!(ssh->remote_bugs & BUG_SSH2_REKEY)) + if (!(ssh->remote_bugs & BUG_SSH2_REKEY) && !ssh->bare_connection) ADD_SPECIALS(ssh2_rekey_special); if (ssh->mainchan) ADD_SPECIALS(ssh2_session_specials); + + if (ssh->n_uncert_hostkeys) { + static const struct telnet_special uncert_start[] = { + {NULL, TS_SEP}, + {"Cache new host key type", TS_SUBMENU}, + }; + static const struct telnet_special uncert_end[] = { + {NULL, TS_EXITMENU}, + }; + int i; + + ADD_SPECIALS(uncert_start); + for (i = 0; i < ssh->n_uncert_hostkeys; i++) { + struct telnet_special uncert[1]; + const struct ssh_signkey *alg = + hostkey_algs[ssh->uncert_hostkeys[i]].alg; + uncert[0].name = alg->name; + uncert[0].code = TS_LOCALSTART + ssh->uncert_hostkeys[i]; + ADD_SPECIALS(uncert); + } + ADD_SPECIALS(uncert_end); + } } /* else we're not ready yet */ - if (i) { + if (nspecials) ADD_SPECIALS(specials_end); - return ssh_specials; + + ssh->specials = specials; + + if (nspecials) { + return specials; } else { return NULL; } @@ -10056,9 +11713,17 @@ static void ssh_special(void *handle, Telnet_Special code) } } } else if (code == TS_REKEY) { - if (!ssh->kex_in_progress && ssh->version == 2) { + if (!ssh->kex_in_progress && !ssh->bare_connection && + ssh->version == 2) { do_ssh2_transport(ssh, "at user request", -1, NULL); } + } else if (code >= TS_LOCALSTART) { + ssh->hostkey = hostkey_algs[code - TS_LOCALSTART].alg; + ssh->cross_certifying = TRUE; + if (!ssh->kex_in_progress && !ssh->bare_connection && + ssh->version == 2) { + do_ssh2_transport(ssh, "cross-certifying new host key", -1, NULL); + } } else if (code == TS_BRK) { if (ssh->state == SSH_STATE_CLOSED || ssh->state == SSH_STATE_PREPACKET) return; @@ -10071,7 +11736,7 @@ static void ssh_special(void *handle, Telnet_Special code) } } else { /* Is is a POSIX signal? */ - char *signame = NULL; + const char *signame = NULL; if (code == TS_SIGABRT) signame = "ABRT"; if (code == TS_SIGALRM) signame = "ALRM"; if (code == TS_SIGFPE) signame = "FPE"; @@ -10101,21 +11766,54 @@ static void ssh_special(void *handle, Telnet_Special code) } } -void *new_sock_channel(void *handle, Socket s) +void *new_sock_channel(void *handle, struct PortForwarding *pf) { Ssh ssh = (Ssh) handle; struct ssh_channel *c; c = snew(struct ssh_channel); c->ssh = ssh; - ssh2_channel_init(c); + ssh_channel_init(c); c->halfopen = TRUE; - c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */ - c->u.pfd.s = s; - add234(ssh->channels, c); + c->type = CHAN_SOCKDATA;/* identify channel type */ + c->u.pfd.pf = pf; return c; } +unsigned ssh_alloc_sharing_channel(Ssh ssh, void *sharing_ctx) +{ + struct ssh_channel *c; + c = snew(struct ssh_channel); + + c->ssh = ssh; + ssh_channel_init(c); + c->type = CHAN_SHARING; + c->u.sharing.ctx = sharing_ctx; + return c->localid; +} + +void ssh_delete_sharing_channel(Ssh ssh, unsigned localid) +{ + struct ssh_channel *c; + + c = find234(ssh->channels, &localid, ssh_channelfind); + if (c) + ssh_channel_destroy(c); +} + +void ssh_send_packet_from_downstream(Ssh ssh, unsigned id, int type, + const void *data, int datalen, + const char *additional_log_text) +{ + struct Packet *pkt; + + pkt = ssh2_pkt_init(type); + pkt->downstream_id = id; + pkt->additional_log_text = additional_log_text; + ssh2_pkt_adddata(pkt, data, datalen); + ssh2_pkt_send(ssh, pkt); +} + /* * This is called when stdout/stderr (the entity to which * from_backend sends data) manages to clear some backlog. @@ -10123,7 +11821,6 @@ void *new_sock_channel(void *handle, Socket s) static void ssh_unthrottle(void *handle, int bufsize) { Ssh ssh = (Ssh) handle; - int buflimit; if (ssh->version == 1) { if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) { @@ -10131,19 +11828,8 @@ static void ssh_unthrottle(void *handle, int bufsize) ssh_throttle_conn(ssh, -1); } } else { - if (ssh->mainchan) { - ssh2_set_window(ssh->mainchan, - bufsize < ssh->mainchan->v.v2.locmaxwin ? - ssh->mainchan->v.v2.locmaxwin - bufsize : 0); - if (conf_get_int(ssh->conf, CONF_ssh_simple)) - buflimit = 0; - else - buflimit = ssh->mainchan->v.v2.locmaxwin; - if (ssh->mainchan->throttling_conn && bufsize <= buflimit) { - ssh->mainchan->throttling_conn = 0; - ssh_throttle_conn(ssh, -1); - } - } + if (ssh->mainchan) + ssh_channel_unthrottle(ssh->mainchan, bufsize); } /* @@ -10153,13 +11839,14 @@ static void ssh_unthrottle(void *handle, int bufsize) ssh_process_queued_incoming_data(ssh); } -void ssh_send_port_open(void *channel, char *hostname, int port, char *org) +void ssh_send_port_open(void *channel, const char *hostname, int port, + const char *org) { struct ssh_channel *c = (struct ssh_channel *)channel; Ssh ssh = c->ssh; struct Packet *pktout; - logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port); + logeventf(ssh, "Opening connection to %s:%d for %s", hostname, port, org); if (ssh->version == 1) { send_packet(ssh, SSH1_MSG_PORT_OPEN, @@ -10169,12 +11856,12 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org) /* PKT_STR, , */ PKT_END); } else { - pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN); - ssh2_pkt_addstring(pktout, "direct-tcpip"); - ssh2_pkt_adduint32(pktout, c->localid); - ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */ - ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */ - ssh2_pkt_addstring(pktout, hostname); + pktout = ssh2_chanopen_init(c, "direct-tcpip"); + { + char *trimmed_host = host_strduptrim(hostname); + ssh2_pkt_addstring(pktout, trimmed_host); + sfree(trimmed_host); + } ssh2_pkt_adduint32(pktout, port); /* * We make up values for the originator data; partly it's @@ -10235,13 +11922,19 @@ static int ssh_return_exitcode(void *handle) } /* - * cfg_info for SSH is the currently running version of the - * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.) + * cfg_info for SSH is the protocol running in this session. + * (1 or 2 for the full SSH-1 or SSH-2 protocol; -1 for the bare + * SSH-2 connection protocol, i.e. a downstream; 0 for not-decided-yet.) */ static int ssh_cfg_info(void *handle) { Ssh ssh = (Ssh) handle; - return ssh->version; + if (ssh->version == 0) + return 0; /* don't know yet */ + else if (ssh->bare_connection) + return -1; + else + return ssh->version; } /* @@ -10272,6 +11965,7 @@ Backend ssh_backend = { ssh_provide_logctx, ssh_unthrottle, ssh_cfg_info, + ssh_test_for_upstream, "ssh", PROT_SSH, 22