17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
167 #define translate(x) if (type == x) return #x
168 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
169 static char *ssh1_pkt_type(int type)
171 translate(SSH1_MSG_DISCONNECT);
172 translate(SSH1_SMSG_PUBLIC_KEY);
173 translate(SSH1_CMSG_SESSION_KEY);
174 translate(SSH1_CMSG_USER);
175 translate(SSH1_CMSG_AUTH_RSA);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
178 translate(SSH1_CMSG_AUTH_PASSWORD);
179 translate(SSH1_CMSG_REQUEST_PTY);
180 translate(SSH1_CMSG_WINDOW_SIZE);
181 translate(SSH1_CMSG_EXEC_SHELL);
182 translate(SSH1_CMSG_EXEC_CMD);
183 translate(SSH1_SMSG_SUCCESS);
184 translate(SSH1_SMSG_FAILURE);
185 translate(SSH1_CMSG_STDIN_DATA);
186 translate(SSH1_SMSG_STDOUT_DATA);
187 translate(SSH1_SMSG_STDERR_DATA);
188 translate(SSH1_CMSG_EOF);
189 translate(SSH1_SMSG_EXIT_STATUS);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
192 translate(SSH1_MSG_CHANNEL_DATA);
193 translate(SSH1_MSG_CHANNEL_CLOSE);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
195 translate(SSH1_SMSG_X11_OPEN);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
197 translate(SSH1_MSG_PORT_OPEN);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
199 translate(SSH1_SMSG_AGENT_OPEN);
200 translate(SSH1_MSG_IGNORE);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
204 translate(SSH1_MSG_DEBUG);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION);
206 translate(SSH1_CMSG_AUTH_TIS);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
209 translate(SSH1_CMSG_AUTH_CCARD);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
214 static char *ssh2_pkt_type(int pkt_ctx, int type)
216 translate(SSH2_MSG_DISCONNECT);
217 translate(SSH2_MSG_IGNORE);
218 translate(SSH2_MSG_UNIMPLEMENTED);
219 translate(SSH2_MSG_DEBUG);
220 translate(SSH2_MSG_SERVICE_REQUEST);
221 translate(SSH2_MSG_SERVICE_ACCEPT);
222 translate(SSH2_MSG_KEXINIT);
223 translate(SSH2_MSG_NEWKEYS);
224 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
225 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
230 translate(SSH2_MSG_USERAUTH_REQUEST);
231 translate(SSH2_MSG_USERAUTH_FAILURE);
232 translate(SSH2_MSG_USERAUTH_SUCCESS);
233 translate(SSH2_MSG_USERAUTH_BANNER);
234 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
238 translate(SSH2_MSG_GLOBAL_REQUEST);
239 translate(SSH2_MSG_REQUEST_SUCCESS);
240 translate(SSH2_MSG_REQUEST_FAILURE);
241 translate(SSH2_MSG_CHANNEL_OPEN);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
245 translate(SSH2_MSG_CHANNEL_DATA);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
247 translate(SSH2_MSG_CHANNEL_EOF);
248 translate(SSH2_MSG_CHANNEL_CLOSE);
249 translate(SSH2_MSG_CHANNEL_REQUEST);
250 translate(SSH2_MSG_CHANNEL_SUCCESS);
251 translate(SSH2_MSG_CHANNEL_FAILURE);
257 #define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
263 #define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
269 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
271 /* Coroutine mechanics for the sillier bits of the code */
272 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
277 #define crFinish(z) } *crLine = 0; return (z); }
278 #define crFinishV } *crLine = 0; return; }
279 #define crReturn(z) \
281 *crLine =__LINE__; return (z); case __LINE__:;\
285 *crLine=__LINE__; return; case __LINE__:;\
287 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
288 #define crStopV do{ *crLine = 0; return; }while(0)
289 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
290 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
292 typedef struct ssh_tag *Ssh;
294 static void ssh2_pkt_init(Ssh, int pkt_type);
295 static void ssh2_pkt_addbool(Ssh, unsigned char value);
296 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
297 static void ssh2_pkt_addstring_start(Ssh);
298 static void ssh2_pkt_addstring_str(Ssh, char *data);
299 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
300 static void ssh2_pkt_addstring(Ssh, char *data);
301 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
302 static void ssh2_pkt_addmp(Ssh, Bignum b);
303 static int ssh2_pkt_construct(Ssh);
304 static void ssh2_pkt_send(Ssh);
307 * Buffer management constants. There are several of these for
308 * various different purposes:
310 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
311 * on a local data stream before we throttle the whole SSH
312 * connection (in SSH1 only). Throttling the whole connection is
313 * pretty drastic so we set this high in the hope it won't
316 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
317 * on the SSH connection itself before we defensively throttle
318 * _all_ local data streams. This is pretty drastic too (though
319 * thankfully unlikely in SSH2 since the window mechanism should
320 * ensure that the server never has any need to throttle its end
321 * of the connection), so we set this high as well.
323 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
327 #define SSH1_BUFFER_LIMIT 32768
328 #define SSH_MAX_BACKLOG 32768
329 #define OUR_V2_WINSIZE 16384
331 const static struct ssh_kex *kex_algs[] = {
332 &ssh_diffiehellman_gex,
336 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
338 static void *nullmac_make_context(void)
342 static void nullmac_free_context(void *handle)
345 static void nullmac_key(void *handle, unsigned char *key)
348 static void nullmac_generate(void *handle, unsigned char *blk, int len,
352 static int nullmac_verify(void *handle, unsigned char *blk, int len,
357 const static struct ssh_mac ssh_mac_none = {
358 nullmac_make_context, nullmac_free_context, nullmac_key,
359 nullmac_generate, nullmac_verify, "none", 0
361 const static struct ssh_mac *macs[] = {
362 &ssh_sha1, &ssh_md5, &ssh_mac_none
364 const static struct ssh_mac *buggymacs[] = {
365 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
368 static void *ssh_comp_none_init(void)
372 static void ssh_comp_none_cleanup(void *handle)
375 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
376 unsigned char **outblock, int *outlen)
380 static int ssh_comp_none_disable(void *handle)
384 const static struct ssh_compress ssh_comp_none = {
386 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
387 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
388 ssh_comp_none_disable, NULL
390 extern const struct ssh_compress ssh_zlib;
391 const static struct ssh_compress *compressions[] = {
392 &ssh_zlib, &ssh_comp_none
395 enum { /* channel types */
400 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
404 * 2-3-4 tree storing channels.
407 Ssh ssh; /* pointer back to main context */
408 unsigned remoteid, localid;
411 * In SSH1, this value contains four bits:
413 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
414 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
415 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
416 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
418 * A channel is completely finished with when all four bits are set.
422 struct ssh1_data_channel {
425 struct ssh2_data_channel {
427 unsigned remwindow, remmaxpkt;
432 struct ssh_agent_channel {
433 unsigned char *message;
434 unsigned char msglen[4];
435 int lensofar, totallen;
437 struct ssh_x11_channel {
440 struct ssh_pfd_channel {
447 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
448 * 2 use this structure in different ways, reflecting SSH 2's
449 * altogether saner approach to port forwarding.
451 * In SSH 1, you arrange a remote forwarding by sending the server
452 * the remote port number, and the local destination host:port.
453 * When a connection comes in, the server sends you back that
454 * host:port pair, and you connect to it. This is a ready-made
455 * security hole if you're not on the ball: a malicious server
456 * could send you back _any_ host:port pair, so if you trustingly
457 * connect to the address it gives you then you've just opened the
458 * entire inside of your corporate network just by connecting
459 * through it to a dodgy SSH server. Hence, we must store a list of
460 * host:port pairs we _are_ trying to forward to, and reject a
461 * connection request from the server if it's not in the list.
463 * In SSH 2, each side of the connection minds its own business and
464 * doesn't send unnecessary information to the other. You arrange a
465 * remote forwarding by sending the server just the remote port
466 * number. When a connection comes in, the server tells you which
467 * of its ports was connected to; and _you_ have to remember what
468 * local host:port pair went with that port number.
470 * Hence: in SSH 1 this structure stores host:port pairs we intend
471 * to allow connections to, and is indexed by those host:port
472 * pairs. In SSH 2 it stores a mapping from source port to
473 * destination host:port pair, and is indexed by source port.
475 struct ssh_rportfwd {
476 unsigned sport, dport;
489 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
490 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
491 static void ssh_size(void *handle, int width, int height);
492 static void ssh_special(void *handle, Telnet_Special);
493 static int ssh2_try_send(struct ssh_channel *c);
494 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
495 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
496 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
497 static int ssh_sendbuffer(void *handle);
499 struct rdpkt1_state_tag {
500 long len, pad, biglen, to_read;
501 unsigned long realcrc, gotcrc;
507 struct rdpkt2_state_tag {
508 long len, pad, payload, packetlen, maclen;
511 unsigned long incoming_sequence;
515 const struct plug_function_table *fn;
516 /* the above field _must_ be first in the structure */
518 SHA_State exhash, exhashbase;
525 unsigned char session_key[32];
527 int v1_remote_protoflags;
528 int v1_local_protoflags;
529 int agentfwd_enabled;
532 const struct ssh_cipher *cipher;
535 const struct ssh2_cipher *cscipher, *sccipher;
536 void *cs_cipher_ctx, *sc_cipher_ctx;
537 const struct ssh_mac *csmac, *scmac;
538 void *cs_mac_ctx, *sc_mac_ctx;
539 const struct ssh_compress *cscomp, *sccomp;
540 void *cs_comp_ctx, *sc_comp_ctx;
541 const struct ssh_kex *kex;
542 const struct ssh_signkey *hostkey;
543 unsigned char v2_session_id[20];
549 int echoing, editing;
553 int term_width, term_height;
555 tree234 *channels; /* indexed by local id */
556 struct ssh_channel *mainchan; /* primary session channel */
563 SSH_STATE_BEFORE_SIZE,
569 int size_needed, eof_needed;
572 struct Packet pktout;
573 unsigned char *deferred_send_data;
574 int deferred_len, deferred_size;
577 * Gross hack: pscp will try to start SFTP but fall back to
578 * scp1 if that fails. This variable is the means by which
579 * scp.c can reach into the SSH code and find out which one it
585 * Used for username and password input.
587 char *userpass_input_buffer;
588 int userpass_input_buflen;
589 int userpass_input_bufpos;
590 int userpass_input_echo;
592 char *portfwd_strptr;
598 int v1_throttle_count;
601 int v1_stdout_throttling;
602 int v2_outgoing_sequence;
604 int ssh1_rdpkt_crstate;
605 int ssh2_rdpkt_crstate;
606 int do_ssh_init_crstate;
607 int ssh_gotdata_crstate;
608 int ssh1_protocol_crstate;
609 int do_ssh1_login_crstate;
610 int do_ssh2_transport_crstate;
611 int do_ssh2_authconn_crstate;
613 void *do_ssh_init_state;
614 void *do_ssh1_login_state;
615 void *do_ssh2_transport_state;
616 void *do_ssh2_authconn_state;
618 struct rdpkt1_state_tag rdpkt1_state;
619 struct rdpkt2_state_tag rdpkt2_state;
621 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
622 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
625 #define logevent(s) logevent(ssh->frontend, s)
627 /* logevent, only printf-formatted. */
628 static void logeventf(Ssh ssh, char *fmt, ...)
634 buf = dupvprintf(fmt, ap);
640 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
641 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
642 logeventf msg, connection_fatal msg )
644 static int ssh_channelcmp(void *av, void *bv)
646 struct ssh_channel *a = (struct ssh_channel *) av;
647 struct ssh_channel *b = (struct ssh_channel *) bv;
648 if (a->localid < b->localid)
650 if (a->localid > b->localid)
654 static int ssh_channelfind(void *av, void *bv)
656 unsigned *a = (unsigned *) av;
657 struct ssh_channel *b = (struct ssh_channel *) bv;
665 static int ssh_rportcmp_ssh1(void *av, void *bv)
667 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
668 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
670 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
671 return i < 0 ? -1 : +1;
672 if (a->dport > b->dport)
674 if (a->dport < b->dport)
679 static int ssh_rportcmp_ssh2(void *av, void *bv)
681 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
682 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
684 if (a->sport > b->sport)
686 if (a->sport < b->sport)
691 static int alloc_channel_id(Ssh ssh)
693 const unsigned CHANNEL_NUMBER_OFFSET = 256;
694 unsigned low, high, mid;
696 struct ssh_channel *c;
699 * First-fit allocation of channel numbers: always pick the
700 * lowest unused one. To do this, binary-search using the
701 * counted B-tree to find the largest channel ID which is in a
702 * contiguous sequence from the beginning. (Precisely
703 * everything in that sequence must have ID equal to its tree
704 * index plus CHANNEL_NUMBER_OFFSET.)
706 tsize = count234(ssh->channels);
710 while (high - low > 1) {
711 mid = (high + low) / 2;
712 c = index234(ssh->channels, mid);
713 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
714 low = mid; /* this one is fine */
716 high = mid; /* this one is past it */
719 * Now low points to either -1, or the tree index of the
720 * largest ID in the initial sequence.
723 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
724 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
726 return low + 1 + CHANNEL_NUMBER_OFFSET;
729 static void c_write(Ssh ssh, char *buf, int len)
731 if ((flags & FLAG_STDERR)) {
733 for (i = 0; i < len; i++)
735 fputc(buf[i], stderr);
738 from_backend(ssh->frontend, 1, buf, len);
741 static void c_write_untrusted(Ssh ssh, char *buf, int len)
744 for (i = 0; i < len; i++) {
746 c_write(ssh, "\r\n", 2);
747 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
748 c_write(ssh, buf + i, 1);
752 static void c_write_str(Ssh ssh, char *buf)
754 c_write(ssh, buf, strlen(buf));
758 * Collect incoming data in the incoming packet buffer.
759 * Decipher and verify the packet when it is completely read.
760 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
761 * Update the *data and *datalen variables.
762 * Return the additional nr of bytes needed, or 0 when
763 * a complete packet is available.
765 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
767 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
769 crBegin(ssh->ssh1_rdpkt_crstate);
774 ssh->pktin.length = 0;
776 for (st->i = st->len = 0; st->i < 4; st->i++) {
777 while ((*datalen) == 0)
779 st->len = (st->len << 8) + **data;
780 (*data)++, (*datalen)--;
783 st->pad = 8 - (st->len % 8);
784 st->biglen = st->len + st->pad;
785 ssh->pktin.length = st->len - 5;
787 if (ssh->pktin.maxlen < st->biglen) {
788 ssh->pktin.maxlen = st->biglen;
789 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
792 st->to_read = st->biglen;
793 st->p = ssh->pktin.data;
794 while (st->to_read > 0) {
795 st->chunk = st->to_read;
796 while ((*datalen) == 0)
797 crReturn(st->to_read);
798 if (st->chunk > (*datalen))
799 st->chunk = (*datalen);
800 memcpy(st->p, *data, st->chunk);
802 *datalen -= st->chunk;
804 st->to_read -= st->chunk;
807 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
809 bombout((ssh,"Network attack (CRC compensation) detected!"));
814 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
816 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
817 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
818 if (st->gotcrc != st->realcrc) {
819 bombout((ssh,"Incorrect CRC received on packet"));
823 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
825 if (ssh->v1_compressing) {
826 unsigned char *decompblk;
828 zlib_decompress_block(ssh->sc_comp_ctx,
829 ssh->pktin.body - 1, ssh->pktin.length + 1,
830 &decompblk, &decomplen);
832 if (ssh->pktin.maxlen < st->pad + decomplen) {
833 ssh->pktin.maxlen = st->pad + decomplen;
834 ssh->pktin.data = srealloc(ssh->pktin.data,
835 ssh->pktin.maxlen + APIEXTRA);
836 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
839 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
841 ssh->pktin.length = decomplen - 1;
844 ssh->pktin.type = ssh->pktin.body[-1];
847 log_packet(ssh->logctx,
848 PKT_INCOMING, ssh->pktin.type,
849 ssh1_pkt_type(ssh->pktin.type),
850 ssh->pktin.body, ssh->pktin.length);
852 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
853 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
854 ssh->pktin.type == SSH1_MSG_DEBUG ||
855 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
856 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
857 long stringlen = GET_32BIT(ssh->pktin.body);
858 if (stringlen + 4 != ssh->pktin.length) {
859 bombout((ssh,"Received data packet with bogus string length"));
864 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
865 /* log debug message */
867 int stringlen = GET_32BIT(ssh->pktin.body);
868 strcpy(buf, "Remote debug message: ");
871 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
872 buf[8 + stringlen] = '\0';
875 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
880 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
881 /* log reason code in disconnect message */
883 unsigned msglen = GET_32BIT(ssh->pktin.body);
885 strcpy(buf, "Remote sent disconnect: ");
886 nowlen = strlen(buf);
887 if (msglen > sizeof(buf) - nowlen - 1)
888 msglen = sizeof(buf) - nowlen - 1;
889 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
890 buf[nowlen + msglen] = '\0';
891 /* logevent(buf); (this is now done within the bombout macro) */
892 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
899 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
901 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
903 crBegin(ssh->ssh2_rdpkt_crstate);
907 ssh->pktin.length = 0;
909 st->cipherblk = ssh->sccipher->blksize;
912 if (st->cipherblk < 8)
915 if (ssh->pktin.maxlen < st->cipherblk) {
916 ssh->pktin.maxlen = st->cipherblk;
917 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
921 * Acquire and decrypt the first block of the packet. This will
922 * contain the length and padding details.
924 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
925 while ((*datalen) == 0)
926 crReturn(st->cipherblk - st->i);
927 ssh->pktin.data[st->i] = *(*data)++;
932 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
933 ssh->pktin.data, st->cipherblk);
936 * Now get the length and padding figures.
938 st->len = GET_32BIT(ssh->pktin.data);
939 st->pad = ssh->pktin.data[4];
942 * _Completely_ silly lengths should be stomped on before they
943 * do us any more damage.
945 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
946 bombout((ssh,"Incoming packet was garbled on decryption"));
951 * This enables us to deduce the payload length.
953 st->payload = st->len - st->pad - 1;
955 ssh->pktin.length = st->payload + 5;
958 * So now we can work out the total packet length.
960 st->packetlen = st->len + 4;
961 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
964 * Adjust memory allocation if packet is too big.
966 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
967 ssh->pktin.maxlen = st->packetlen + st->maclen;
968 ssh->pktin.data = srealloc(ssh->pktin.data,
969 ssh->pktin.maxlen + APIEXTRA);
973 * Read and decrypt the remainder of the packet.
975 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
977 while ((*datalen) == 0)
978 crReturn(st->packetlen + st->maclen - st->i);
979 ssh->pktin.data[st->i] = *(*data)++;
982 /* Decrypt everything _except_ the MAC. */
984 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
985 ssh->pktin.data + st->cipherblk,
986 st->packetlen - st->cipherblk);
992 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
993 st->incoming_sequence)) {
994 bombout((ssh,"Incorrect MAC received on packet"));
997 st->incoming_sequence++; /* whether or not we MACed */
1000 * Decompress packet payload.
1003 unsigned char *newpayload;
1006 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1007 ssh->pktin.data + 5, ssh->pktin.length - 5,
1008 &newpayload, &newlen)) {
1009 if (ssh->pktin.maxlen < newlen + 5) {
1010 ssh->pktin.maxlen = newlen + 5;
1011 ssh->pktin.data = srealloc(ssh->pktin.data,
1012 ssh->pktin.maxlen + APIEXTRA);
1014 ssh->pktin.length = 5 + newlen;
1015 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1020 ssh->pktin.savedpos = 6;
1021 ssh->pktin.type = ssh->pktin.data[5];
1024 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1025 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1026 ssh->pktin.data+6, ssh->pktin.length-6);
1028 switch (ssh->pktin.type) {
1030 * These packets we must handle instantly.
1032 case SSH2_MSG_DISCONNECT:
1034 /* log reason code in disconnect message */
1037 int reason = GET_32BIT(ssh->pktin.data + 6);
1038 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1040 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1041 buf = dupprintf("Received disconnect message (%s)",
1042 ssh2_disconnect_reasons[reason]);
1044 buf = dupprintf("Received disconnect message (unknown"
1045 " type %d)", reason);
1049 buf = dupprintf("Disconnection message text: %n%.*s",
1050 &nowlen, msglen, ssh->pktin.data + 14);
1052 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1054 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1055 ssh2_disconnect_reasons[reason] : "unknown",
1061 case SSH2_MSG_IGNORE:
1063 case SSH2_MSG_DEBUG:
1065 /* log the debug message */
1067 /* int display = ssh->pktin.body[6]; */
1068 int stringlen = GET_32BIT(ssh->pktin.data+7);
1070 strcpy(buf, "Remote debug message: ");
1071 prefix = strlen(buf);
1072 if (stringlen > (int)(sizeof(buf)-prefix-1))
1073 stringlen = sizeof(buf)-prefix-1;
1074 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1075 buf[prefix + stringlen] = '\0';
1078 goto next_packet; /* FIXME: print the debug message */
1081 * These packets we need do nothing about here.
1083 case SSH2_MSG_UNIMPLEMENTED:
1084 case SSH2_MSG_SERVICE_REQUEST:
1085 case SSH2_MSG_SERVICE_ACCEPT:
1086 case SSH2_MSG_KEXINIT:
1087 case SSH2_MSG_NEWKEYS:
1088 case SSH2_MSG_KEXDH_INIT:
1089 case SSH2_MSG_KEXDH_REPLY:
1090 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1091 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1092 case SSH2_MSG_KEX_DH_GEX_INIT:
1093 case SSH2_MSG_KEX_DH_GEX_REPLY:
1094 case SSH2_MSG_USERAUTH_REQUEST:
1095 case SSH2_MSG_USERAUTH_FAILURE:
1096 case SSH2_MSG_USERAUTH_SUCCESS:
1097 case SSH2_MSG_USERAUTH_BANNER:
1098 case SSH2_MSG_USERAUTH_PK_OK:
1099 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1100 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1101 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1102 case SSH2_MSG_GLOBAL_REQUEST:
1103 case SSH2_MSG_REQUEST_SUCCESS:
1104 case SSH2_MSG_REQUEST_FAILURE:
1105 case SSH2_MSG_CHANNEL_OPEN:
1106 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1107 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1108 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1109 case SSH2_MSG_CHANNEL_DATA:
1110 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1111 case SSH2_MSG_CHANNEL_EOF:
1112 case SSH2_MSG_CHANNEL_CLOSE:
1113 case SSH2_MSG_CHANNEL_REQUEST:
1114 case SSH2_MSG_CHANNEL_SUCCESS:
1115 case SSH2_MSG_CHANNEL_FAILURE:
1119 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1122 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1123 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1131 static void ssh1_pktout_size(Ssh ssh, int len)
1135 len += 5; /* type and CRC */
1136 pad = 8 - (len % 8);
1139 ssh->pktout.length = len - 5;
1140 if (ssh->pktout.maxlen < biglen) {
1141 ssh->pktout.maxlen = biglen;
1143 /* Allocate enough buffer space for extra block
1144 * for MS CryptEncrypt() */
1145 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1147 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1150 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1153 static void s_wrpkt_start(Ssh ssh, int type, int len)
1155 ssh1_pktout_size(ssh, len);
1156 ssh->pktout.type = type;
1159 static int s_wrpkt_prepare(Ssh ssh)
1161 int pad, len, biglen, i;
1164 ssh->pktout.body[-1] = ssh->pktout.type;
1167 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1168 ssh1_pkt_type(ssh->pktout.type),
1169 ssh->pktout.body, ssh->pktout.length);
1171 if (ssh->v1_compressing) {
1172 unsigned char *compblk;
1174 zlib_compress_block(ssh->cs_comp_ctx,
1175 ssh->pktout.body - 1, ssh->pktout.length + 1,
1176 &compblk, &complen);
1177 ssh1_pktout_size(ssh, complen - 1);
1178 memcpy(ssh->pktout.body - 1, compblk, complen);
1182 len = ssh->pktout.length + 5; /* type and CRC */
1183 pad = 8 - (len % 8);
1186 for (i = 0; i < pad; i++)
1187 ssh->pktout.data[i + 4] = random_byte();
1188 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1189 PUT_32BIT(ssh->pktout.data + biglen, crc);
1190 PUT_32BIT(ssh->pktout.data, len);
1193 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1198 static void s_wrpkt(Ssh ssh)
1201 len = s_wrpkt_prepare(ssh);
1202 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1203 if (backlog > SSH_MAX_BACKLOG)
1204 ssh_throttle_all(ssh, 1, backlog);
1207 static void s_wrpkt_defer(Ssh ssh)
1210 len = s_wrpkt_prepare(ssh);
1211 if (ssh->deferred_len + len > ssh->deferred_size) {
1212 ssh->deferred_size = ssh->deferred_len + len + 128;
1213 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1214 ssh->deferred_size);
1216 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1217 ssh->deferred_len += len;
1221 * Construct a packet with the specified contents.
1223 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1225 unsigned char *p, *argp, argchar;
1226 unsigned long argint;
1227 int pktlen, argtype, arglen;
1231 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1234 (void) va_arg(ap1, int);
1238 (void) va_arg(ap1, int);
1242 (void) va_arg(ap1, unsigned char *);
1243 arglen = va_arg(ap1, int);
1247 argp = va_arg(ap1, unsigned char *);
1248 arglen = strlen((char *)argp);
1249 pktlen += 4 + arglen;
1252 bn = va_arg(ap1, Bignum);
1253 pktlen += ssh1_bignum_length(bn);
1260 s_wrpkt_start(ssh, pkttype, pktlen);
1261 p = ssh->pktout.body;
1263 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1266 argint = va_arg(ap2, int);
1267 PUT_32BIT(p, argint);
1271 argchar = (unsigned char) va_arg(ap2, int);
1276 argp = va_arg(ap2, unsigned char *);
1277 arglen = va_arg(ap2, int);
1278 memcpy(p, argp, arglen);
1282 argp = va_arg(ap2, unsigned char *);
1283 arglen = strlen((char *)argp);
1284 PUT_32BIT(p, arglen);
1285 memcpy(p + 4, argp, arglen);
1289 bn = va_arg(ap2, Bignum);
1290 p += ssh1_write_bignum(p, bn);
1296 static void send_packet(Ssh ssh, int pkttype, ...)
1299 va_start(ap1, pkttype);
1300 va_start(ap2, pkttype);
1301 construct_packet(ssh, pkttype, ap1, ap2);
1305 static void defer_packet(Ssh ssh, int pkttype, ...)
1308 va_start(ap1, pkttype);
1309 va_start(ap2, pkttype);
1310 construct_packet(ssh, pkttype, ap1, ap2);
1314 static int ssh_versioncmp(char *a, char *b)
1317 unsigned long av, bv;
1319 av = strtoul(a, &ae, 10);
1320 bv = strtoul(b, &be, 10);
1322 return (av < bv ? -1 : +1);
1327 av = strtoul(ae, &ae, 10);
1328 bv = strtoul(be, &be, 10);
1330 return (av < bv ? -1 : +1);
1335 * Utility routines for putting an SSH-protocol `string' and
1336 * `uint32' into a SHA state.
1339 static void sha_string(SHA_State * s, void *str, int len)
1341 unsigned char lenblk[4];
1342 PUT_32BIT(lenblk, len);
1343 SHA_Bytes(s, lenblk, 4);
1344 SHA_Bytes(s, str, len);
1347 static void sha_uint32(SHA_State * s, unsigned i)
1349 unsigned char intblk[4];
1350 PUT_32BIT(intblk, i);
1351 SHA_Bytes(s, intblk, 4);
1355 * SSH2 packet construction functions.
1357 static void ssh2_pkt_ensure(Ssh ssh, int length)
1359 if (ssh->pktout.maxlen < length) {
1360 ssh->pktout.maxlen = length + 256;
1361 ssh->pktout.data = srealloc(ssh->pktout.data,
1362 ssh->pktout.maxlen + APIEXTRA);
1363 if (!ssh->pktout.data)
1364 fatalbox("Out of memory");
1367 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1369 ssh->pktout.length += len;
1370 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1371 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1373 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1375 ssh2_pkt_adddata(ssh, &byte, 1);
1377 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1379 ssh->pktout.length = 5;
1380 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1382 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1384 ssh2_pkt_adddata(ssh, &value, 1);
1386 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1389 PUT_32BIT(x, value);
1390 ssh2_pkt_adddata(ssh, x, 4);
1392 static void ssh2_pkt_addstring_start(Ssh ssh)
1394 ssh2_pkt_adduint32(ssh, 0);
1395 ssh->pktout.savedpos = ssh->pktout.length;
1397 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1399 ssh2_pkt_adddata(ssh, data, strlen(data));
1400 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1401 ssh->pktout.length - ssh->pktout.savedpos);
1403 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1405 ssh2_pkt_adddata(ssh, data, len);
1406 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1407 ssh->pktout.length - ssh->pktout.savedpos);
1409 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1411 ssh2_pkt_addstring_start(ssh);
1412 ssh2_pkt_addstring_str(ssh, data);
1414 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1417 int i, n = (bignum_bitcount(b) + 7) / 8;
1420 fatalbox("out of memory");
1422 for (i = 1; i <= n; i++)
1423 p[i] = bignum_byte(b, n - i);
1425 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1427 memmove(p, p + i, n + 1 - i);
1431 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1435 p = ssh2_mpint_fmt(b, &len);
1436 ssh2_pkt_addstring_start(ssh);
1437 ssh2_pkt_addstring_data(ssh, (char *)p, len);
1442 * Construct an SSH2 final-form packet: compress it, encrypt it,
1443 * put the MAC on it. Final packet, ready to be sent, is stored in
1444 * ssh->pktout.data. Total length is returned.
1446 static int ssh2_pkt_construct(Ssh ssh)
1448 int cipherblk, maclen, padding, i;
1451 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1452 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1453 ssh->pktout.data + 6, ssh->pktout.length - 6);
1456 * Compress packet payload.
1459 unsigned char *newpayload;
1462 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1463 ssh->pktout.length - 5,
1464 &newpayload, &newlen)) {
1465 ssh->pktout.length = 5;
1466 ssh2_pkt_adddata(ssh, newpayload, newlen);
1472 * Add padding. At least four bytes, and must also bring total
1473 * length (minus MAC) up to a multiple of the block size.
1475 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1476 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1479 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1480 maclen = ssh->csmac ? ssh->csmac->len : 0;
1481 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1482 ssh->pktout.data[4] = padding;
1483 for (i = 0; i < padding; i++)
1484 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1485 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1487 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1488 ssh->pktout.length + padding,
1489 ssh->v2_outgoing_sequence);
1490 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1493 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1494 ssh->pktout.data, ssh->pktout.length + padding);
1496 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1497 return ssh->pktout.length + padding + maclen;
1501 * Construct and send an SSH2 packet immediately.
1503 static void ssh2_pkt_send(Ssh ssh)
1507 len = ssh2_pkt_construct(ssh);
1508 backlog = sk_write(ssh->s, (char *)ssh->pktout.data, len);
1509 if (backlog > SSH_MAX_BACKLOG)
1510 ssh_throttle_all(ssh, 1, backlog);
1514 * Construct an SSH2 packet and add it to a deferred data block.
1515 * Useful for sending multiple packets in a single sk_write() call,
1516 * to prevent a traffic-analysing listener from being able to work
1517 * out the length of any particular packet (such as the password
1520 * Note that because SSH2 sequence-numbers its packets, this can
1521 * NOT be used as an m4-style `defer' allowing packets to be
1522 * constructed in one order and sent in another.
1524 static void ssh2_pkt_defer(Ssh ssh)
1526 int len = ssh2_pkt_construct(ssh);
1527 if (ssh->deferred_len + len > ssh->deferred_size) {
1528 ssh->deferred_size = ssh->deferred_len + len + 128;
1529 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1530 ssh->deferred_size);
1532 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1533 ssh->deferred_len += len;
1537 * Send the whole deferred data block constructed by
1538 * ssh2_pkt_defer() or SSH1's defer_packet().
1540 static void ssh_pkt_defersend(Ssh ssh)
1543 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1545 ssh->deferred_len = ssh->deferred_size = 0;
1546 sfree(ssh->deferred_send_data);
1547 ssh->deferred_send_data = NULL;
1548 if (backlog > SSH_MAX_BACKLOG)
1549 ssh_throttle_all(ssh, 1, backlog);
1553 void bndebug(char *string, Bignum b)
1557 p = ssh2_mpint_fmt(b, &len);
1558 debug(("%s", string));
1559 for (i = 0; i < len; i++)
1560 debug((" %02x", p[i]));
1566 static void sha_mpint(SHA_State * s, Bignum b)
1570 p = ssh2_mpint_fmt(b, &len);
1571 sha_string(s, p, len);
1576 * SSH2 packet decode functions.
1578 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1580 unsigned long value;
1581 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1582 return 0; /* arrgh, no way to decline (FIXME?) */
1583 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1584 ssh->pktin.savedpos += 4;
1587 static int ssh2_pkt_getbool(Ssh ssh)
1589 unsigned long value;
1590 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1591 return 0; /* arrgh, no way to decline (FIXME?) */
1592 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1593 ssh->pktin.savedpos++;
1596 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1601 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1603 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1607 ssh->pktin.savedpos += 4;
1608 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1610 *p = (char *)(ssh->pktin.data + ssh->pktin.savedpos);
1611 ssh->pktin.savedpos += *length;
1613 static Bignum ssh2_pkt_getmp(Ssh ssh)
1619 ssh2_pkt_getstring(ssh, &p, &length);
1623 bombout((ssh,"internal error: Can't handle negative mpints"));
1626 b = bignum_from_bytes((unsigned char *)p, length);
1631 * Helper function to add an SSH2 signature blob to a packet.
1632 * Expects to be shown the public key blob as well as the signature
1633 * blob. Normally works just like ssh2_pkt_addstring, but will
1634 * fiddle with the signature packet if necessary for
1635 * BUG_SSH2_RSA_PADDING.
1637 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1638 void *sigblob_v, int sigblob_len)
1640 unsigned char *pkblob = (unsigned char *)pkblob_v;
1641 unsigned char *sigblob = (unsigned char *)sigblob_v;
1643 /* dmemdump(pkblob, pkblob_len); */
1644 /* dmemdump(sigblob, sigblob_len); */
1647 * See if this is in fact an ssh-rsa signature and a buggy
1648 * server; otherwise we can just do this the easy way.
1650 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1651 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1652 int pos, len, siglen;
1655 * Find the byte length of the modulus.
1658 pos = 4+7; /* skip over "ssh-rsa" */
1659 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1660 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1661 pos += 4; /* find modulus itself */
1662 while (len > 0 && pkblob[pos] == 0)
1664 /* debug(("modulus length is %d\n", len)); */
1667 * Now find the signature integer.
1669 pos = 4+7; /* skip over "ssh-rsa" */
1670 siglen = GET_32BIT(sigblob+pos);
1671 /* debug(("signature length is %d\n", siglen)); */
1673 if (len != siglen) {
1674 unsigned char newlen[4];
1675 ssh2_pkt_addstring_start(ssh);
1676 ssh2_pkt_addstring_data(ssh, (char *)sigblob, pos);
1677 /* dmemdump(sigblob, pos); */
1678 pos += 4; /* point to start of actual sig */
1679 PUT_32BIT(newlen, len);
1680 ssh2_pkt_addstring_data(ssh, (char *)newlen, 4);
1681 /* dmemdump(newlen, 4); */
1683 while (len-- > siglen) {
1684 ssh2_pkt_addstring_data(ssh, (char *)newlen, 1);
1685 /* dmemdump(newlen, 1); */
1687 ssh2_pkt_addstring_data(ssh, (char *)(sigblob+pos), siglen);
1688 /* dmemdump(sigblob+pos, siglen); */
1692 /* Otherwise fall through and do it the easy way. */
1695 ssh2_pkt_addstring_start(ssh);
1696 ssh2_pkt_addstring_data(ssh, (char *)sigblob, sigblob_len);
1700 * Examine the remote side's version string and compare it against
1701 * a list of known buggy implementations.
1703 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1705 char *imp; /* pointer to implementation part */
1707 imp += strcspn(imp, "-");
1709 imp += strcspn(imp, "-");
1712 ssh->remote_bugs = 0;
1714 if (cfg.sshbug_ignore1 == BUG_ON ||
1715 (cfg.sshbug_ignore1 == BUG_AUTO &&
1716 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1717 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1718 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1720 * These versions don't support SSH1_MSG_IGNORE, so we have
1721 * to use a different defence against password length
1724 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1725 logevent("We believe remote version has SSH1 ignore bug");
1728 if (cfg.sshbug_plainpw1 == BUG_ON ||
1729 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1730 (!strcmp(imp, "Cisco-1.25")))) {
1732 * These versions need a plain password sent; they can't
1733 * handle having a null and a random length of data after
1736 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1737 logevent("We believe remote version needs a plain SSH1 password");
1740 if (cfg.sshbug_rsa1 == BUG_ON ||
1741 (cfg.sshbug_rsa1 == BUG_AUTO &&
1742 (!strcmp(imp, "Cisco-1.25")))) {
1744 * These versions apparently have no clue whatever about
1745 * RSA authentication and will panic and die if they see
1746 * an AUTH_RSA message.
1748 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1749 logevent("We believe remote version can't handle RSA authentication");
1752 if (cfg.sshbug_hmac2 == BUG_ON ||
1753 (cfg.sshbug_hmac2 == BUG_AUTO &&
1754 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1755 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1756 wc_match("2.1 *", imp)))) {
1758 * These versions have the HMAC bug.
1760 ssh->remote_bugs |= BUG_SSH2_HMAC;
1761 logevent("We believe remote version has SSH2 HMAC bug");
1764 if (cfg.sshbug_derivekey2 == BUG_ON ||
1765 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1766 (wc_match("2.0.0*", imp) || wc_match("2.0.1[01]*", imp) ))) {
1768 * These versions have the key-derivation bug (failing to
1769 * include the literal shared secret in the hashes that
1770 * generate the keys).
1772 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1773 logevent("We believe remote version has SSH2 key-derivation bug");
1776 if (cfg.sshbug_rsapad2 == BUG_ON ||
1777 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1778 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1779 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1781 * These versions have the SSH2 RSA padding bug.
1783 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1784 logevent("We believe remote version has SSH2 RSA padding bug");
1787 if (cfg.sshbug_dhgex2 == BUG_ON) {
1789 * User specified the SSH2 DH GEX bug.
1791 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1792 logevent("We believe remote version has SSH2 DH group exchange bug");
1796 static int do_ssh_init(Ssh ssh, unsigned char c)
1798 struct do_ssh_init_state {
1806 crState(do_ssh_init_state);
1808 crBegin(ssh->do_ssh_init_crstate);
1810 /* Search for the string "SSH-" in the input. */
1813 static const int transS[] = { 1, 2, 2, 1 };
1814 static const int transH[] = { 0, 0, 3, 0 };
1815 static const int transminus[] = { 0, 0, 0, -1 };
1817 s->i = transS[s->i];
1819 s->i = transH[s->i];
1821 s->i = transminus[s->i];
1826 crReturn(1); /* get another character */
1830 s->vstring = smalloc(s->vstrsize);
1831 strcpy(s->vstring, "SSH-");
1835 crReturn(1); /* get another char */
1836 if (s->vslen >= s->vstrsize - 1) {
1838 s->vstring = srealloc(s->vstring, s->vstrsize);
1840 s->vstring[s->vslen++] = c;
1843 s->version[s->i] = '\0';
1845 } else if (s->i < sizeof(s->version) - 1)
1846 s->version[s->i++] = c;
1847 } else if (c == '\n')
1851 ssh->agentfwd_enabled = FALSE;
1852 ssh->rdpkt2_state.incoming_sequence = 0;
1854 s->vstring[s->vslen] = 0;
1855 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1858 vlog = smalloc(20 + s->vslen);
1859 sprintf(vlog, "Server version: %s", s->vstring);
1863 ssh_detect_bugs(ssh, s->vstring);
1866 * Decide which SSH protocol version to support.
1869 /* Anything strictly below "2.0" means protocol 1 is supported. */
1870 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1871 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1872 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1874 if (cfg.sshprot == 0 && !s->proto1) {
1875 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
1878 if (cfg.sshprot == 3 && !s->proto2) {
1879 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
1883 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1887 char verstring[80], vlog[100];
1888 sprintf(verstring, "SSH-2.0-%s", sshver);
1889 SHA_Init(&ssh->exhashbase);
1891 * Hash our version string and their version string.
1893 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1894 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1895 sprintf(vlog, "We claim version: %s", verstring);
1897 strcat(verstring, "\n");
1898 logevent("Using SSH protocol version 2");
1899 sk_write(ssh->s, verstring, strlen(verstring));
1900 ssh->protocol = ssh2_protocol;
1902 ssh->s_rdpkt = ssh2_rdpkt;
1907 char verstring[80], vlog[100];
1908 sprintf(verstring, "SSH-%s-%s",
1909 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1911 sprintf(vlog, "We claim version: %s", verstring);
1913 strcat(verstring, "\n");
1915 logevent("Using SSH protocol version 1");
1916 sk_write(ssh->s, verstring, strlen(verstring));
1917 ssh->protocol = ssh1_protocol;
1919 ssh->s_rdpkt = ssh1_rdpkt;
1921 ssh->state = SSH_STATE_BEFORE_SIZE;
1928 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1930 crBegin(ssh->ssh_gotdata_crstate);
1933 * To begin with, feed the characters one by one to the
1934 * protocol initialisation / selection function do_ssh_init().
1935 * When that returns 0, we're done with the initial greeting
1936 * exchange and can move on to packet discipline.
1939 int ret; /* need not be kept across crReturn */
1941 crReturnV; /* more data please */
1942 ret = do_ssh_init(ssh, *data);
1950 * We emerge from that loop when the initial negotiation is
1951 * over and we have selected an s_rdpkt function. Now pass
1952 * everything to s_rdpkt, and then pass the resulting packets
1953 * to the proper protocol handler.
1958 while (datalen > 0) {
1959 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1960 if (ssh->state == SSH_STATE_CLOSED) {
1963 ssh->protocol(ssh, NULL, 0, 1);
1964 if (ssh->state == SSH_STATE_CLOSED) {
1974 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1977 Ssh ssh = (Ssh) plug;
1978 ssh->state = SSH_STATE_CLOSED;
1984 /* A socket error has occurred. */
1985 logevent(error_msg);
1986 connection_fatal(ssh->frontend, error_msg);
1988 /* Otherwise, the remote side closed the connection normally. */
1993 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1995 Ssh ssh = (Ssh) plug;
1996 ssh_gotdata(ssh, (unsigned char *)data, len);
1997 if (ssh->state == SSH_STATE_CLOSED) {
2007 static void ssh_sent(Plug plug, int bufsize)
2009 Ssh ssh = (Ssh) plug;
2011 * If the send backlog on the SSH socket itself clears, we
2012 * should unthrottle the whole world if it was throttled.
2014 if (bufsize < SSH_MAX_BACKLOG)
2015 ssh_throttle_all(ssh, 0, bufsize);
2019 * Connect to specified host and port.
2020 * Returns an error message, or NULL on success.
2021 * Also places the canonical host name into `realhost'. It must be
2022 * freed by the caller.
2024 static char *connect_to_host(Ssh ssh, char *host, int port,
2025 char **realhost, int nodelay)
2027 static const struct plug_function_table fn_table = {
2037 ssh->savedhost = smalloc(1 + strlen(host));
2038 if (!ssh->savedhost)
2039 fatalbox("Out of memory");
2040 strcpy(ssh->savedhost, host);
2043 port = 22; /* default ssh port */
2044 ssh->savedport = port;
2049 logeventf(ssh, "Looking up host \"%s\"", host);
2050 addr = name_lookup(host, port, realhost);
2051 if ((err = sk_addr_error(addr)) != NULL)
2059 sk_getaddr(addr, addrbuf, 100);
2060 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2062 ssh->fn = &fn_table;
2063 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2064 if ((err = sk_socket_error(ssh->s)) != NULL) {
2073 * Throttle or unthrottle the SSH connection.
2075 static void ssh1_throttle(Ssh ssh, int adjust)
2077 int old_count = ssh->v1_throttle_count;
2078 ssh->v1_throttle_count += adjust;
2079 assert(ssh->v1_throttle_count >= 0);
2080 if (ssh->v1_throttle_count && !old_count) {
2081 sk_set_frozen(ssh->s, 1);
2082 } else if (!ssh->v1_throttle_count && old_count) {
2083 sk_set_frozen(ssh->s, 0);
2088 * Throttle or unthrottle _all_ local data streams (for when sends
2089 * on the SSH connection itself back up).
2091 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2094 struct ssh_channel *c;
2096 if (enable == ssh->throttled_all)
2098 ssh->throttled_all = enable;
2099 ssh->overall_bufsize = bufsize;
2102 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2104 case CHAN_MAINSESSION:
2106 * This is treated separately, outside the switch.
2110 x11_override_throttle(c->u.x11.s, enable);
2113 /* Agent channels require no buffer management. */
2116 pfd_override_throttle(c->u.x11.s, enable);
2123 * Username and password input, abstracted off into routines
2124 * reusable in several places - even between SSH1 and SSH2.
2127 /* Set up a username or password input loop on a given buffer. */
2128 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2130 ssh->userpass_input_buffer = buffer;
2131 ssh->userpass_input_buflen = buflen;
2132 ssh->userpass_input_bufpos = 0;
2133 ssh->userpass_input_echo = echo;
2137 * Process some terminal data in the course of username/password
2138 * input. Returns >0 for success (line of input returned in
2139 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2140 * for inconclusive (keep waiting for more input please).
2142 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2147 switch (c = *in++) {
2150 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2151 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2156 if (ssh->userpass_input_bufpos > 0) {
2157 if (ssh->userpass_input_echo)
2158 c_write_str(ssh, "\b \b");
2159 ssh->userpass_input_bufpos--;
2164 while (ssh->userpass_input_bufpos > 0) {
2165 if (ssh->userpass_input_echo)
2166 c_write_str(ssh, "\b \b");
2167 ssh->userpass_input_bufpos--;
2175 if (((c >= ' ' && c <= '~') ||
2176 ((unsigned char) c >= 160))
2177 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2178 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2179 if (ssh->userpass_input_echo)
2180 c_write(ssh, &c, 1);
2189 * Handle the key exchange and user authentication phases.
2191 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2194 unsigned char cookie[8];
2195 struct RSAKey servkey, hostkey;
2196 struct MD5Context md5c;
2197 struct do_ssh1_login_state {
2199 unsigned char *rsabuf, *keystr1, *keystr2;
2200 unsigned long supported_ciphers_mask, supported_auths_mask;
2201 int tried_publickey, tried_agent;
2202 int tis_auth_refused, ccard_auth_refused;
2203 unsigned char session_id[16];
2206 void *publickey_blob;
2207 int publickey_bloblen;
2213 unsigned char request[5], *response, *p;
2222 crState(do_ssh1_login_state);
2224 crBegin(ssh->do_ssh1_login_crstate);
2229 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2230 bombout((ssh,"Public key packet not received"));
2234 logevent("Received public keys");
2236 memcpy(cookie, ssh->pktin.body, 8);
2238 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2239 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2242 * Log the host key fingerprint.
2246 logevent("Host key fingerprint is:");
2247 strcpy(logmsg, " ");
2248 hostkey.comment = NULL;
2249 rsa_fingerprint(logmsg + strlen(logmsg),
2250 sizeof(logmsg) - strlen(logmsg), &hostkey);
2254 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2255 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2256 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2258 ssh->v1_local_protoflags =
2259 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2260 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2263 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2264 MD5Update(&md5c, s->keystr1, servkey.bytes);
2265 MD5Update(&md5c, ssh->pktin.body, 8);
2266 MD5Final(s->session_id, &md5c);
2268 for (i = 0; i < 32; i++)
2269 ssh->session_key[i] = random_byte();
2271 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2273 s->rsabuf = smalloc(s->len);
2275 fatalbox("Out of memory");
2278 * Verify the host key.
2282 * First format the key into a string.
2284 int len = rsastr_len(&hostkey);
2285 char fingerprint[100];
2286 char *keystr = smalloc(len);
2288 fatalbox("Out of memory");
2289 rsastr_fmt(keystr, &hostkey);
2290 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2291 verify_ssh_host_key(ssh->frontend,
2292 ssh->savedhost, ssh->savedport, "rsa", keystr,
2297 for (i = 0; i < 32; i++) {
2298 s->rsabuf[i] = ssh->session_key[i];
2300 s->rsabuf[i] ^= s->session_id[i];
2303 if (hostkey.bytes > servkey.bytes) {
2304 rsaencrypt(s->rsabuf, 32, &servkey);
2305 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2307 rsaencrypt(s->rsabuf, 32, &hostkey);
2308 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2311 logevent("Encrypted session key");
2314 int cipher_chosen = 0, warn = 0;
2315 char *cipher_string = NULL;
2317 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2318 int next_cipher = cfg.ssh_cipherlist[i];
2319 if (next_cipher == CIPHER_WARN) {
2320 /* If/when we choose a cipher, warn about it */
2322 } else if (next_cipher == CIPHER_AES) {
2323 /* XXX Probably don't need to mention this. */
2324 logevent("AES not supported in SSH1, skipping");
2326 switch (next_cipher) {
2327 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2328 cipher_string = "3DES"; break;
2329 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2330 cipher_string = "Blowfish"; break;
2331 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2332 cipher_string = "single-DES"; break;
2334 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2338 if (!cipher_chosen) {
2339 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2340 bombout((ssh,"Server violates SSH 1 protocol by not "
2341 "supporting 3DES encryption"));
2343 /* shouldn't happen */
2344 bombout((ssh,"No supported ciphers found"));
2348 /* Warn about chosen cipher if necessary. */
2350 askcipher(ssh->frontend, cipher_string, 0);
2353 switch (s->cipher_type) {
2354 case SSH_CIPHER_3DES:
2355 logevent("Using 3DES encryption");
2357 case SSH_CIPHER_DES:
2358 logevent("Using single-DES encryption");
2360 case SSH_CIPHER_BLOWFISH:
2361 logevent("Using Blowfish encryption");
2365 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2366 PKT_CHAR, s->cipher_type,
2367 PKT_DATA, cookie, 8,
2368 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2369 PKT_DATA, s->rsabuf, s->len,
2370 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2372 logevent("Trying to enable encryption...");
2376 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2377 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2379 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2380 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2381 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2383 ssh->crcda_ctx = crcda_make_context();
2384 logevent("Installing CRC compensation attack detector");
2388 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2389 bombout((ssh,"Encryption not successfully enabled"));
2393 logevent("Successfully started encryption");
2397 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2398 if (ssh_get_line && !ssh_getline_pw_only) {
2399 if (!ssh_get_line("login as: ",
2400 s->username, sizeof(s->username), FALSE)) {
2402 * get_line failed to get a username.
2405 logevent("No username provided. Abandoning session.");
2406 ssh->state = SSH_STATE_CLOSED;
2410 int ret; /* need not be kept over crReturn */
2411 c_write_str(ssh, "login as: ");
2414 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2416 crWaitUntil(!ispkt);
2417 ret = process_userpass_input(ssh, in, inlen);
2421 c_write_str(ssh, "\r\n");
2424 strncpy(s->username, cfg.username, sizeof(s->username));
2425 s->username[sizeof(s->username)-1] = '\0';
2428 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2430 char userlog[22 + sizeof(s->username)];
2431 sprintf(userlog, "Sent username \"%s\"", s->username);
2433 if (flags & FLAG_INTERACTIVE &&
2434 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2435 strcat(userlog, "\r\n");
2436 c_write_str(ssh, userlog);
2443 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2444 /* We must not attempt PK auth. Pretend we've already tried it. */
2445 s->tried_publickey = s->tried_agent = 1;
2447 s->tried_publickey = s->tried_agent = 0;
2449 s->tis_auth_refused = s->ccard_auth_refused = 0;
2450 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2452 if (!rsakey_pubblob(cfg.keyfile,
2453 &s->publickey_blob, &s->publickey_bloblen))
2454 s->publickey_blob = NULL;
2456 s->publickey_blob = NULL;
2458 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2459 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2461 if (agent_exists() && !s->tried_agent) {
2463 * Attempt RSA authentication using Pageant.
2469 logevent("Pageant is running. Requesting keys.");
2471 /* Request the keys held by the agent. */
2472 PUT_32BIT(s->request, 1);
2473 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2474 agent_query(s->request, 5, &r, &s->responselen);
2475 s->response = (unsigned char *) r;
2476 if (s->response && s->responselen >= 5 &&
2477 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2478 s->p = s->response + 5;
2479 s->nkeys = GET_32BIT(s->p);
2483 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2486 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2489 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2492 if (s->publickey_blob &&
2493 !memcmp(s->p, s->publickey_blob,
2494 s->publickey_bloblen)) {
2495 logevent("This key matches configured key file");
2496 s->tried_publickey = 1;
2499 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2500 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2501 s->commentlen = GET_32BIT(s->p);
2503 s->commentp = (char *)s->p;
2504 s->p += s->commentlen;
2505 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2506 PKT_BIGNUM, s->key.modulus, PKT_END);
2508 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2509 logevent("Key refused");
2512 logevent("Received RSA challenge");
2513 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2515 char *agentreq, *q, *ret;
2518 len = 1 + 4; /* message type, bit count */
2519 len += ssh1_bignum_length(s->key.exponent);
2520 len += ssh1_bignum_length(s->key.modulus);
2521 len += ssh1_bignum_length(s->challenge);
2522 len += 16; /* session id */
2523 len += 4; /* response format */
2524 agentreq = smalloc(4 + len);
2525 PUT_32BIT(agentreq, len);
2527 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2528 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2530 q += ssh1_write_bignum(q, s->key.exponent);
2531 q += ssh1_write_bignum(q, s->key.modulus);
2532 q += ssh1_write_bignum(q, s->challenge);
2533 memcpy(q, s->session_id, 16);
2535 PUT_32BIT(q, 1); /* response format */
2536 agent_query(agentreq, len + 4, &vret, &retlen);
2540 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2541 logevent("Sending Pageant's response");
2542 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2543 PKT_DATA, ret + 5, 16,
2547 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2549 ("Pageant's response accepted");
2550 if (flags & FLAG_VERBOSE) {
2551 c_write_str(ssh, "Authenticated using"
2553 c_write(ssh, s->commentp,
2555 c_write_str(ssh, "\" from agent\r\n");
2560 ("Pageant's response not accepted");
2563 ("Pageant failed to answer challenge");
2567 logevent("No reply received from Pageant");
2570 freebn(s->key.exponent);
2571 freebn(s->key.modulus);
2572 freebn(s->challenge);
2580 if (*cfg.keyfile && !s->tried_publickey)
2581 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2583 if (cfg.try_tis_auth &&
2584 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2585 !s->tis_auth_refused) {
2586 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2587 logevent("Requested TIS authentication");
2588 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2590 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2591 logevent("TIS authentication declined");
2592 if (flags & FLAG_INTERACTIVE)
2593 c_write_str(ssh, "TIS authentication refused.\r\n");
2594 s->tis_auth_refused = 1;
2597 int challengelen = GET_32BIT(ssh->pktin.body);
2598 logevent("Received TIS challenge");
2599 if (challengelen > sizeof(s->prompt) - 1)
2600 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2601 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2602 /* Prompt heuristic comes from OpenSSH */
2603 strncpy(s->prompt + challengelen,
2604 memchr(s->prompt, '\n', challengelen) ?
2605 "": "\r\nResponse: ",
2606 (sizeof s->prompt) - challengelen);
2607 s->prompt[(sizeof s->prompt) - 1] = '\0';
2610 if (cfg.try_tis_auth &&
2611 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2612 !s->ccard_auth_refused) {
2613 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2614 logevent("Requested CryptoCard authentication");
2615 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2617 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2618 logevent("CryptoCard authentication declined");
2619 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2620 s->ccard_auth_refused = 1;
2623 int challengelen = GET_32BIT(ssh->pktin.body);
2624 logevent("Received CryptoCard challenge");
2625 if (challengelen > sizeof(s->prompt) - 1)
2626 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2627 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2628 strncpy(s->prompt + challengelen,
2629 memchr(s->prompt, '\n', challengelen) ?
2630 "" : "\r\nResponse: ",
2631 sizeof(s->prompt) - challengelen);
2632 s->prompt[sizeof(s->prompt) - 1] = '\0';
2635 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2636 sprintf(s->prompt, "%.90s@%.90s's password: ",
2637 s->username, ssh->savedhost);
2639 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2640 char *comment = NULL;
2643 if (flags & FLAG_VERBOSE)
2644 c_write_str(ssh, "Trying public key authentication.\r\n");
2645 logeventf(ssh, "Trying public key \"%s\"", cfg.keyfile);
2646 type = key_type(cfg.keyfile);
2647 if (type != SSH_KEYTYPE_SSH1) {
2648 sprintf(msgbuf, "Key is of wrong type (%s)",
2649 key_type_to_str(type));
2651 c_write_str(ssh, msgbuf);
2652 c_write_str(ssh, "\r\n");
2653 s->tried_publickey = 1;
2656 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2657 if (flags & FLAG_VERBOSE)
2658 c_write_str(ssh, "No passphrase required.\r\n");
2661 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2666 * Show password prompt, having first obtained it via a TIS
2667 * or CryptoCard exchange if we're doing TIS or CryptoCard
2671 if (!ssh_get_line(s->prompt, s->password,
2672 sizeof(s->password), TRUE)) {
2674 * get_line failed to get a password (for example
2675 * because one was supplied on the command line
2676 * which has already failed to work). Terminate.
2678 send_packet(ssh, SSH1_MSG_DISCONNECT,
2679 PKT_STR, "No more passwords available to try",
2681 logevent("Unable to authenticate");
2682 connection_fatal(ssh->frontend, "Unable to authenticate");
2683 ssh->state = SSH_STATE_CLOSED;
2687 /* Prompt may have come from server. We've munged it a bit, so
2688 * we know it to be zero-terminated at least once. */
2689 int ret; /* need not be saved over crReturn */
2690 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2693 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2695 crWaitUntil(!ispkt);
2696 ret = process_userpass_input(ssh, in, inlen);
2700 c_write_str(ssh, "\r\n");
2704 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2706 * Try public key authentication with the specified
2709 s->tried_publickey = 1;
2712 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2714 c_write_str(ssh, "Couldn't load private key from ");
2715 c_write_str(ssh, cfg.keyfile);
2716 c_write_str(ssh, ".\r\n");
2717 continue; /* go and try password */
2720 c_write_str(ssh, "Wrong passphrase.\r\n");
2721 s->tried_publickey = 0;
2722 continue; /* try again */
2727 * Send a public key attempt.
2729 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2730 PKT_BIGNUM, s->key.modulus, PKT_END);
2733 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2734 c_write_str(ssh, "Server refused our public key.\r\n");
2735 continue; /* go and try password */
2737 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2738 bombout((ssh,"Bizarre response to offer of public key"));
2744 unsigned char buffer[32];
2745 Bignum challenge, response;
2747 ssh1_read_bignum(ssh->pktin.body, &challenge);
2748 response = rsadecrypt(challenge, &s->key);
2749 freebn(s->key.private_exponent);/* burn the evidence */
2751 for (i = 0; i < 32; i++) {
2752 buffer[i] = bignum_byte(response, 31 - i);
2756 MD5Update(&md5c, buffer, 32);
2757 MD5Update(&md5c, s->session_id, 16);
2758 MD5Final(buffer, &md5c);
2760 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2761 PKT_DATA, buffer, 16, PKT_END);
2768 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2769 if (flags & FLAG_VERBOSE)
2770 c_write_str(ssh, "Failed to authenticate with"
2771 " our public key.\r\n");
2772 continue; /* go and try password */
2773 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2774 bombout((ssh,"Bizarre response to RSA authentication response"));
2778 break; /* we're through! */
2780 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2782 * Defence against traffic analysis: we send a
2783 * whole bunch of packets containing strings of
2784 * different lengths. One of these strings is the
2785 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2786 * The others are all random data in
2787 * SSH1_MSG_IGNORE packets. This way a passive
2788 * listener can't tell which is the password, and
2789 * hence can't deduce the password length.
2791 * Anybody with a password length greater than 16
2792 * bytes is going to have enough entropy in their
2793 * password that a listener won't find it _that_
2794 * much help to know how long it is. So what we'll
2797 * - if password length < 16, we send 15 packets
2798 * containing string lengths 1 through 15
2800 * - otherwise, we let N be the nearest multiple
2801 * of 8 below the password length, and send 8
2802 * packets containing string lengths N through
2803 * N+7. This won't obscure the order of
2804 * magnitude of the password length, but it will
2805 * introduce a bit of extra uncertainty.
2807 * A few servers (the old 1.2.18 through 1.2.22)
2808 * can't deal with SSH1_MSG_IGNORE. For these
2809 * servers, we need an alternative defence. We make
2810 * use of the fact that the password is interpreted
2811 * as a C string: so we can append a NUL, then some
2814 * One server (a Cisco one) can deal with neither
2815 * SSH1_MSG_IGNORE _nor_ a padded password string.
2816 * For this server we are left with no defences
2817 * against password length sniffing.
2819 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2821 * The server can deal with SSH1_MSG_IGNORE, so
2822 * we can use the primary defence.
2824 int bottom, top, pwlen, i;
2827 pwlen = strlen(s->password);
2829 bottom = 0; /* zero length passwords are OK! :-) */
2832 bottom = pwlen & ~7;
2836 assert(pwlen >= bottom && pwlen <= top);
2838 randomstr = smalloc(top + 1);
2840 for (i = bottom; i <= top; i++) {
2842 defer_packet(ssh, s->pwpkt_type,
2843 PKT_STR, s->password, PKT_END);
2845 for (j = 0; j < i; j++) {
2847 randomstr[j] = random_byte();
2848 } while (randomstr[j] == '\0');
2850 randomstr[i] = '\0';
2851 defer_packet(ssh, SSH1_MSG_IGNORE,
2852 PKT_STR, randomstr, PKT_END);
2855 logevent("Sending password with camouflage packets");
2856 ssh_pkt_defersend(ssh);
2858 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2860 * The server can't deal with SSH1_MSG_IGNORE
2861 * but can deal with padded passwords, so we
2862 * can use the secondary defence.
2868 len = strlen(s->password);
2869 if (len < sizeof(string)) {
2871 strcpy(string, s->password);
2872 len++; /* cover the zero byte */
2873 while (len < sizeof(string)) {
2874 string[len++] = (char) random_byte();
2879 logevent("Sending length-padded password");
2880 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2881 PKT_DATA, ss, len, PKT_END);
2884 * The server has _both_
2885 * BUG_CHOKES_ON_SSH1_IGNORE and
2886 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2887 * therefore nothing we can do.
2890 len = strlen(s->password);
2891 logevent("Sending unpadded password");
2892 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2893 PKT_DATA, s->password, len, PKT_END);
2896 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2899 logevent("Sent password");
2900 memset(s->password, 0, strlen(s->password));
2902 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2903 if (flags & FLAG_VERBOSE)
2904 c_write_str(ssh, "Access denied\r\n");
2905 logevent("Authentication refused");
2906 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2907 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
2912 logevent("Authentication successful");
2917 void sshfwd_close(struct ssh_channel *c)
2921 if (c && !c->closes) {
2923 * If the channel's remoteid is -1, we have sent
2924 * CHANNEL_OPEN for this channel, but it hasn't even been
2925 * acknowledged by the server. So we must set a close flag
2926 * on it now, and then when the server acks the channel
2927 * open, we can close it then.
2929 if (((int)c->remoteid) != -1) {
2930 if (ssh->version == 1) {
2931 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2934 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2935 ssh2_pkt_adduint32(ssh, c->remoteid);
2939 c->closes = 1; /* sent MSG_CLOSE */
2940 if (c->type == CHAN_X11) {
2942 logevent("Forwarded X11 connection terminated");
2943 } else if (c->type == CHAN_SOCKDATA ||
2944 c->type == CHAN_SOCKDATA_DORMANT) {
2946 logevent("Forwarded port closed");
2951 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2955 if (ssh->version == 1) {
2956 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2957 PKT_INT, c->remoteid,
2958 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2960 * In SSH1 we can return 0 here - implying that forwarded
2961 * connections are never individually throttled - because
2962 * the only circumstance that can cause throttling will be
2963 * the whole SSH connection backing up, in which case
2964 * _everything_ will be throttled as a whole.
2968 ssh2_add_channel_data(c, buf, len);
2969 return ssh2_try_send(c);
2973 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2977 if (ssh->version == 1) {
2978 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2979 c->v.v1.throttling = 0;
2980 ssh1_throttle(ssh, -1);
2983 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2987 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2989 crBegin(ssh->ssh1_protocol_crstate);
2993 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
2996 if (ssh->state == SSH_STATE_CLOSED)
2999 if (cfg.agentfwd && agent_exists()) {
3000 logevent("Requesting agent forwarding");
3001 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3005 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3006 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3007 bombout((ssh,"Protocol confusion"));
3009 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3010 logevent("Agent forwarding refused");
3012 logevent("Agent forwarding enabled");
3013 ssh->agentfwd_enabled = TRUE;
3017 if (cfg.x11_forward) {
3018 char proto[20], data[64];
3019 logevent("Requesting X11 forwarding");
3020 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3021 data, sizeof(data));
3022 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3023 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3024 PKT_STR, proto, PKT_STR, data,
3025 PKT_INT, x11_get_screen_number(cfg.x11_display),
3028 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3029 PKT_STR, proto, PKT_STR, data, PKT_END);
3034 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3035 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3036 bombout((ssh,"Protocol confusion"));
3038 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3039 logevent("X11 forwarding refused");
3041 logevent("X11 forwarding enabled");
3042 ssh->X11_fwd_enabled = TRUE;
3049 int sport,dport,sserv,dserv;
3050 char sports[256], dports[256], saddr[256], host[256];
3052 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3053 /* Add port forwardings. */
3054 ssh->portfwd_strptr = cfg.portfwd;
3055 while (*ssh->portfwd_strptr) {
3056 type = *ssh->portfwd_strptr++;
3059 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3060 if (*ssh->portfwd_strptr == ':') {
3062 * We've seen a colon in the middle of the
3063 * source port number. This means that
3064 * everything we've seen until now is the
3065 * source _address_, so we'll move it into
3066 * saddr and start sports from the beginning
3069 ssh->portfwd_strptr++;
3071 strcpy(saddr, sports);
3074 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3077 if (*ssh->portfwd_strptr == '\t')
3078 ssh->portfwd_strptr++;
3080 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3081 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3084 if (*ssh->portfwd_strptr == ':')
3085 ssh->portfwd_strptr++;
3087 while (*ssh->portfwd_strptr) {
3088 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3091 ssh->portfwd_strptr++;
3092 dport = atoi(dports);
3096 dport = net_service_lookup(dports);
3098 logeventf(ssh, "Service lookup failed for"
3099 " destination port \"%s\"", dports);
3102 sport = atoi(sports);
3106 sport = net_service_lookup(sports);
3108 logeventf(ssh, "Service lookup failed for source"
3109 " port \"%s\"", sports);
3112 if (sport && dport) {
3114 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3116 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3117 " forwarding to %s:%.*s%.*s%d%.*s",
3118 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3119 (int)(*saddr?1:0), ":",
3120 (int)(sserv ? strlen(sports) : 0), sports,
3121 sserv, "(", sport, sserv, ")",
3123 (int)(dserv ? strlen(dports) : 0), dports,
3124 dserv, "(", dport, dserv, ")");
3126 struct ssh_rportfwd *pf;
3127 pf = smalloc(sizeof(*pf));
3128 strcpy(pf->dhost, host);
3132 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3135 if (add234(ssh->rportfwds, pf) != pf) {
3137 "Duplicate remote port forwarding to %s:%d",
3141 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3142 " forward to %s:%.*s%.*s%d%.*s",
3143 (int)(sserv ? strlen(sports) : 0), sports,
3144 sserv, "(", sport, sserv, ")",
3146 (int)(dserv ? strlen(dports) : 0), dports,
3147 dserv, "(", dport, dserv, ")");
3148 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3156 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3157 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3158 bombout((ssh,"Protocol confusion"));
3160 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3161 c_write_str(ssh, "Server refused port"
3164 logevent("Remote port forwarding enabled");
3172 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3173 PKT_STR, cfg.termtype,
3174 PKT_INT, ssh->term_height,
3175 PKT_INT, ssh->term_width,
3176 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3177 ssh->state = SSH_STATE_INTERMED;
3181 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3182 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3183 bombout((ssh,"Protocol confusion"));
3185 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3186 c_write_str(ssh, "Server refused to allocate pty\r\n");
3187 ssh->editing = ssh->echoing = 1;
3189 logevent("Allocated pty");
3191 ssh->editing = ssh->echoing = 1;
3194 if (cfg.compression) {
3195 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3199 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3200 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3201 bombout((ssh,"Protocol confusion"));
3203 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3204 c_write_str(ssh, "Server refused to compress\r\n");
3206 logevent("Started compression");
3207 ssh->v1_compressing = TRUE;
3208 ssh->cs_comp_ctx = zlib_compress_init();
3209 logevent("Initialised zlib (RFC1950) compression");
3210 ssh->sc_comp_ctx = zlib_decompress_init();
3211 logevent("Initialised zlib (RFC1950) decompression");
3215 * Start the shell or command.
3217 * Special case: if the first-choice command is an SSH2
3218 * subsystem (hence not usable here) and the second choice
3219 * exists, we fall straight back to that.
3222 char *cmd = cfg.remote_cmd_ptr;
3224 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3225 cmd = cfg.remote_cmd_ptr2;
3226 ssh->fallback_cmd = TRUE;
3229 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3231 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3232 logevent("Started session");
3235 ssh->state = SSH_STATE_SESSION;
3236 if (ssh->size_needed)
3237 ssh_size(ssh, ssh->term_width, ssh->term_height);
3238 if (ssh->eof_needed)
3239 ssh_special(ssh, TS_EOF);
3242 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3244 ssh->channels = newtree234(ssh_channelcmp);
3248 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3249 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3250 long len = GET_32BIT(ssh->pktin.body);
3252 from_backend(ssh->frontend,
3253 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3254 (char *)(ssh->pktin.body) + 4, len);
3255 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3256 ssh->v1_stdout_throttling = 1;
3257 ssh1_throttle(ssh, +1);
3259 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3260 ssh->state = SSH_STATE_CLOSED;
3261 logevent("Received disconnect request");
3263 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3264 /* Remote side is trying to open a channel to talk to our
3265 * X-Server. Give them back a local channel number. */
3266 struct ssh_channel *c;
3268 logevent("Received X11 connect request");
3269 /* Refuse if X11 forwarding is disabled. */
3270 if (!ssh->X11_fwd_enabled) {
3271 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3272 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3273 logevent("Rejected X11 connect request");
3275 c = smalloc(sizeof(struct ssh_channel));
3278 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3279 ssh->x11auth) != NULL) {
3280 logevent("opening X11 forward connection failed");
3282 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3283 PKT_INT, GET_32BIT(ssh->pktin.body),
3287 ("opening X11 forward connection succeeded");
3288 c->remoteid = GET_32BIT(ssh->pktin.body);
3289 c->localid = alloc_channel_id(ssh);
3291 c->v.v1.throttling = 0;
3292 c->type = CHAN_X11; /* identify channel type */
3293 add234(ssh->channels, c);
3294 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3295 PKT_INT, c->remoteid, PKT_INT,
3296 c->localid, PKT_END);
3297 logevent("Opened X11 forward channel");
3300 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3301 /* Remote side is trying to open a channel to talk to our
3302 * agent. Give them back a local channel number. */
3303 struct ssh_channel *c;
3305 /* Refuse if agent forwarding is disabled. */
3306 if (!ssh->agentfwd_enabled) {
3307 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3308 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3310 c = smalloc(sizeof(struct ssh_channel));
3312 c->remoteid = GET_32BIT(ssh->pktin.body);
3313 c->localid = alloc_channel_id(ssh);
3315 c->v.v1.throttling = 0;
3316 c->type = CHAN_AGENT; /* identify channel type */
3317 c->u.a.lensofar = 0;
3318 add234(ssh->channels, c);
3319 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3320 PKT_INT, c->remoteid, PKT_INT, c->localid,
3323 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3324 /* Remote side is trying to open a channel to talk to a
3325 * forwarded port. Give them back a local channel number. */
3326 struct ssh_channel *c;
3327 struct ssh_rportfwd pf;
3329 char host[256], buf[1024];
3331 c = smalloc(sizeof(struct ssh_channel));
3334 hostsize = GET_32BIT(ssh->pktin.body+4);
3335 for (h = host, p = (char *)(ssh->pktin.body+8);
3336 hostsize != 0; hostsize--) {
3337 if (h+1 < host+sizeof(host))
3342 port = GET_32BIT(p);
3344 strcpy(pf.dhost, host);
3347 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3348 sprintf(buf, "Rejected remote port open request for %s:%d",
3351 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3352 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3354 sprintf(buf, "Received remote port open request for %s:%d",
3357 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3360 sprintf(buf, "Port open failed: %s", e);
3363 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3364 PKT_INT, GET_32BIT(ssh->pktin.body),
3367 c->remoteid = GET_32BIT(ssh->pktin.body);
3368 c->localid = alloc_channel_id(ssh);
3370 c->v.v1.throttling = 0;
3371 c->type = CHAN_SOCKDATA; /* identify channel type */
3372 add234(ssh->channels, c);
3373 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3374 PKT_INT, c->remoteid, PKT_INT,
3375 c->localid, PKT_END);
3376 logevent("Forwarded port opened successfully");
3380 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3381 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3382 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3383 struct ssh_channel *c;
3385 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3386 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3387 c->remoteid = localid;
3388 c->type = CHAN_SOCKDATA;
3389 c->v.v1.throttling = 0;
3390 pfd_confirm(c->u.pfd.s);
3393 if (c && c->closes) {
3395 * We have a pending close on this channel,
3396 * which we decided on before the server acked
3397 * the channel open. So now we know the
3398 * remoteid, we can close it again.
3400 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3401 PKT_INT, c->remoteid, PKT_END);
3404 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3405 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3406 struct ssh_channel *c;
3408 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3409 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3410 logevent("Forwarded connection refused by server");
3411 pfd_close(c->u.pfd.s);
3412 del234(ssh->channels, c);
3416 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3417 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3418 /* Remote side closes a channel. */
3419 unsigned i = GET_32BIT(ssh->pktin.body);
3420 struct ssh_channel *c;
3421 c = find234(ssh->channels, &i, ssh_channelfind);
3422 if (c && ((int)c->remoteid) != -1) {
3425 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3427 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3428 logevent("Forwarded X11 connection terminated");
3429 assert(c->u.x11.s != NULL);
3430 x11_close(c->u.x11.s);
3433 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3434 logevent("Forwarded port closed");
3435 assert(c->u.pfd.s != NULL);
3436 pfd_close(c->u.pfd.s);
3440 c->closes |= (closetype << 2); /* seen this message */
3441 if (!(c->closes & closetype)) {
3442 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3444 c->closes |= closetype; /* sent it too */
3447 if (c->closes == 15) {
3448 del234(ssh->channels, c);
3452 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3453 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3454 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3457 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3458 /* Data sent down one of our channels. */
3459 int i = GET_32BIT(ssh->pktin.body);
3460 int len = GET_32BIT(ssh->pktin.body + 4);
3461 unsigned char *p = ssh->pktin.body + 8;
3462 struct ssh_channel *c;
3463 c = find234(ssh->channels, &i, ssh_channelfind);
3468 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3471 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3474 /* Data for an agent message. Buffer it. */
3476 if (c->u.a.lensofar < 4) {
3477 int l = min(4 - c->u.a.lensofar, len);
3478 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3482 c->u.a.lensofar += l;
3484 if (c->u.a.lensofar == 4) {
3486 4 + GET_32BIT(c->u.a.msglen);
3487 c->u.a.message = smalloc(c->u.a.totallen);
3488 memcpy(c->u.a.message, c->u.a.msglen, 4);
3490 if (c->u.a.lensofar >= 4 && len > 0) {
3492 min(c->u.a.totallen - c->u.a.lensofar,
3494 memcpy(c->u.a.message + c->u.a.lensofar, p,
3498 c->u.a.lensofar += l;
3500 if (c->u.a.lensofar == c->u.a.totallen) {
3501 void *reply, *sentreply;
3503 agent_query(c->u.a.message,
3504 c->u.a.totallen, &reply,
3509 /* Fake SSH_AGENT_FAILURE. */
3510 sentreply = "\0\0\0\1\5";
3513 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3514 PKT_INT, c->remoteid,
3516 PKT_DATA, sentreply, replylen,
3520 sfree(c->u.a.message);
3521 c->u.a.lensofar = 0;
3524 bufsize = 0; /* agent channels never back up */
3527 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3528 c->v.v1.throttling = 1;
3529 ssh1_throttle(ssh, +1);
3532 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3533 /* may be from EXEC_SHELL on some servers */
3534 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3535 /* may be from EXEC_SHELL on some servers
3536 * if no pty is available or in other odd cases. Ignore */
3537 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3539 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3540 sprintf(buf, "Server sent command exit status %d",
3543 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3545 * In case `helpful' firewalls or proxies tack
3546 * extra human-readable text on the end of the
3547 * session which we might mistake for another
3548 * encrypted packet, we close the session once
3549 * we've sent EXIT_CONFIRMATION.
3551 ssh->state = SSH_STATE_CLOSED;
3554 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3559 int len = min(inlen, 512);
3560 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3561 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3572 * Utility routine for decoding comma-separated strings in KEXINIT.
3574 static int in_commasep_string(char *needle, char *haystack, int haylen)
3577 if (!needle || !haystack) /* protect against null pointers */
3579 needlen = strlen(needle);
3582 * Is it at the start of the string?
3584 if (haylen >= needlen && /* haystack is long enough */
3585 !memcmp(needle, haystack, needlen) && /* initial match */
3586 (haylen == needlen || haystack[needlen] == ',')
3587 /* either , or EOS follows */
3591 * If not, search for the next comma and resume after that.
3592 * If no comma found, terminate.
3594 while (haylen > 0 && *haystack != ',')
3595 haylen--, haystack++;
3598 haylen--, haystack++; /* skip over comma itself */
3603 * SSH2 key creation method.
3605 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3606 unsigned char *sessid, char chr,
3607 unsigned char *keyspace)
3610 /* First 20 bytes. */
3612 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3614 SHA_Bytes(&s, H, 20);
3615 SHA_Bytes(&s, &chr, 1);
3616 SHA_Bytes(&s, sessid, 20);
3617 SHA_Final(&s, keyspace);
3618 /* Next 20 bytes. */
3620 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3622 SHA_Bytes(&s, H, 20);
3623 SHA_Bytes(&s, keyspace, 20);
3624 SHA_Final(&s, keyspace + 20);
3628 * Handle the SSH2 transport layer.
3630 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3632 struct do_ssh2_transport_state {
3633 int nbits, pbits, warn;
3634 Bignum p, g, e, f, K;
3635 int kex_init_value, kex_reply_value;
3636 const struct ssh_mac **maclist;
3638 const struct ssh2_cipher *cscipher_tobe;
3639 const struct ssh2_cipher *sccipher_tobe;
3640 const struct ssh_mac *csmac_tobe;
3641 const struct ssh_mac *scmac_tobe;
3642 const struct ssh_compress *cscomp_tobe;
3643 const struct ssh_compress *sccomp_tobe;
3644 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3645 int hostkeylen, siglen;
3646 void *hkey; /* actual host key */
3647 unsigned char exchange_hash[20];
3648 int n_preferred_ciphers;
3649 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3650 const struct ssh_compress *preferred_comp;
3653 crState(do_ssh2_transport_state);
3655 crBegin(ssh->do_ssh2_transport_crstate);
3657 s->cscipher_tobe = s->sccipher_tobe = NULL;
3658 s->csmac_tobe = s->scmac_tobe = NULL;
3659 s->cscomp_tobe = s->sccomp_tobe = NULL;
3667 * Set up the preferred ciphers. (NULL => warn below here)
3669 s->n_preferred_ciphers = 0;
3670 for (i = 0; i < CIPHER_MAX; i++) {
3671 switch (cfg.ssh_cipherlist[i]) {
3672 case CIPHER_BLOWFISH:
3673 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3676 if (cfg.ssh2_des_cbc) {
3677 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3681 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3684 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3687 /* Flag for later. Don't bother if it's the last in
3689 if (i < CIPHER_MAX - 1) {
3690 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3698 * Set up preferred compression.
3700 if (cfg.compression)
3701 s->preferred_comp = &ssh_zlib;
3703 s->preferred_comp = &ssh_comp_none;
3706 * Be prepared to work around the buggy MAC problem.
3708 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3709 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3711 s->maclist = macs, s->nmacs = lenof(macs);
3715 int i, j, cipherstr_started;
3718 * Construct and send our key exchange packet.
3720 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3721 for (i = 0; i < 16; i++)
3722 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3723 /* List key exchange algorithms. */
3724 ssh2_pkt_addstring_start(ssh);
3725 for (i = 0; i < lenof(kex_algs); i++) {
3726 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3727 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3729 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3730 if (i < lenof(kex_algs) - 1)
3731 ssh2_pkt_addstring_str(ssh, ",");
3733 /* List server host key algorithms. */
3734 ssh2_pkt_addstring_start(ssh);
3735 for (i = 0; i < lenof(hostkey_algs); i++) {
3736 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3737 if (i < lenof(hostkey_algs) - 1)
3738 ssh2_pkt_addstring_str(ssh, ",");
3740 /* List client->server encryption algorithms. */
3741 ssh2_pkt_addstring_start(ssh);
3742 cipherstr_started = 0;
3743 for (i = 0; i < s->n_preferred_ciphers; i++) {
3744 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3745 if (!c) continue; /* warning flag */
3746 for (j = 0; j < c->nciphers; j++) {
3747 if (cipherstr_started)
3748 ssh2_pkt_addstring_str(ssh, ",");
3749 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3750 cipherstr_started = 1;
3753 /* List server->client encryption algorithms. */
3754 ssh2_pkt_addstring_start(ssh);
3755 cipherstr_started = 0;
3756 for (i = 0; i < s->n_preferred_ciphers; i++) {
3757 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3758 if (!c) continue; /* warning flag */
3759 for (j = 0; j < c->nciphers; j++) {
3760 if (cipherstr_started)
3761 ssh2_pkt_addstring_str(ssh, ",");
3762 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3763 cipherstr_started = 1;
3766 /* List client->server MAC algorithms. */
3767 ssh2_pkt_addstring_start(ssh);
3768 for (i = 0; i < s->nmacs; i++) {
3769 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3770 if (i < s->nmacs - 1)
3771 ssh2_pkt_addstring_str(ssh, ",");
3773 /* List server->client MAC algorithms. */
3774 ssh2_pkt_addstring_start(ssh);
3775 for (i = 0; i < s->nmacs; i++) {
3776 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3777 if (i < s->nmacs - 1)
3778 ssh2_pkt_addstring_str(ssh, ",");
3780 /* List client->server compression algorithms. */
3781 ssh2_pkt_addstring_start(ssh);
3782 for (i = 0; i < lenof(compressions) + 1; i++) {
3783 const struct ssh_compress *c =
3784 i == 0 ? s->preferred_comp : compressions[i - 1];
3785 ssh2_pkt_addstring_str(ssh, c->name);
3786 if (i < lenof(compressions))
3787 ssh2_pkt_addstring_str(ssh, ",");
3789 /* List server->client compression algorithms. */
3790 ssh2_pkt_addstring_start(ssh);
3791 for (i = 0; i < lenof(compressions) + 1; i++) {
3792 const struct ssh_compress *c =
3793 i == 0 ? s->preferred_comp : compressions[i - 1];
3794 ssh2_pkt_addstring_str(ssh, c->name);
3795 if (i < lenof(compressions))
3796 ssh2_pkt_addstring_str(ssh, ",");
3798 /* List client->server languages. Empty list. */
3799 ssh2_pkt_addstring_start(ssh);
3800 /* List server->client languages. Empty list. */
3801 ssh2_pkt_addstring_start(ssh);
3802 /* First KEX packet does _not_ follow, because we're not that brave. */
3803 ssh2_pkt_addbool(ssh, FALSE);
3805 ssh2_pkt_adduint32(ssh, 0);
3808 ssh->exhash = ssh->exhashbase;
3809 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3815 if (ssh->pktin.length > 5)
3816 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3819 * Now examine the other side's KEXINIT to see what we're up
3826 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3827 bombout((ssh,"expected key exchange packet from server"));
3831 ssh->hostkey = NULL;
3832 s->cscipher_tobe = NULL;
3833 s->sccipher_tobe = NULL;
3834 s->csmac_tobe = NULL;
3835 s->scmac_tobe = NULL;
3836 s->cscomp_tobe = NULL;
3837 s->sccomp_tobe = NULL;
3838 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3839 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3840 for (i = 0; i < lenof(kex_algs); i++) {
3841 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3842 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3844 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3845 ssh->kex = kex_algs[i];
3849 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3850 for (i = 0; i < lenof(hostkey_algs); i++) {
3851 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3852 ssh->hostkey = hostkey_algs[i];
3856 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3858 for (i = 0; i < s->n_preferred_ciphers; i++) {
3859 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3863 for (j = 0; j < c->nciphers; j++) {
3864 if (in_commasep_string(c->list[j]->name, str, len)) {
3865 s->cscipher_tobe = c->list[j];
3870 if (s->cscipher_tobe) {
3872 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3876 if (!s->cscipher_tobe) {
3877 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3878 str ? str : "(null)"));
3882 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3884 for (i = 0; i < s->n_preferred_ciphers; i++) {
3885 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3889 for (j = 0; j < c->nciphers; j++) {
3890 if (in_commasep_string(c->list[j]->name, str, len)) {
3891 s->sccipher_tobe = c->list[j];
3896 if (s->sccipher_tobe) {
3898 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3902 if (!s->sccipher_tobe) {
3903 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3904 str ? str : "(null)"));
3908 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3909 for (i = 0; i < s->nmacs; i++) {
3910 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3911 s->csmac_tobe = s->maclist[i];
3915 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3916 for (i = 0; i < s->nmacs; i++) {
3917 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3918 s->scmac_tobe = s->maclist[i];
3922 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3923 for (i = 0; i < lenof(compressions) + 1; i++) {
3924 const struct ssh_compress *c =
3925 i == 0 ? s->preferred_comp : compressions[i - 1];
3926 if (in_commasep_string(c->name, str, len)) {
3931 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3932 for (i = 0; i < lenof(compressions) + 1; i++) {
3933 const struct ssh_compress *c =
3934 i == 0 ? s->preferred_comp : compressions[i - 1];
3935 if (in_commasep_string(c->name, str, len)) {
3943 * Work out the number of bits of key we will need from the key
3944 * exchange. We start with the maximum key length of either
3950 csbits = s->cscipher_tobe->keylen;
3951 scbits = s->sccipher_tobe->keylen;
3952 s->nbits = (csbits > scbits ? csbits : scbits);
3954 /* The keys only have 160-bit entropy, since they're based on
3955 * a SHA-1 hash. So cap the key size at 160 bits. */
3960 * If we're doing Diffie-Hellman group exchange, start by
3961 * requesting a group.
3963 if (ssh->kex == &ssh_diffiehellman_gex) {
3964 logevent("Doing Diffie-Hellman group exchange");
3965 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3967 * Work out how big a DH group we will need to allow that
3970 s->pbits = 512 << ((s->nbits - 1) / 64);
3971 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3972 ssh2_pkt_adduint32(ssh, s->pbits);
3976 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3977 bombout((ssh,"expected key exchange group packet from server"));
3980 s->p = ssh2_pkt_getmp(ssh);
3981 s->g = ssh2_pkt_getmp(ssh);
3982 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3983 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3984 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3986 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3987 ssh->kex_ctx = dh_setup_group1();
3988 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3989 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3992 logevent("Doing Diffie-Hellman key exchange");
3994 * Now generate and send e for Diffie-Hellman.
3996 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
3997 ssh2_pkt_init(ssh, s->kex_init_value);
3998 ssh2_pkt_addmp(ssh, s->e);
4002 if (ssh->pktin.type != s->kex_reply_value) {
4003 bombout((ssh,"expected key exchange reply packet from server"));
4006 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4007 s->f = ssh2_pkt_getmp(ssh);
4008 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4010 s->K = dh_find_K(ssh->kex_ctx, s->f);
4012 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4013 if (ssh->kex == &ssh_diffiehellman_gex) {
4014 sha_uint32(&ssh->exhash, s->pbits);
4015 sha_mpint(&ssh->exhash, s->p);
4016 sha_mpint(&ssh->exhash, s->g);
4018 sha_mpint(&ssh->exhash, s->e);
4019 sha_mpint(&ssh->exhash, s->f);
4020 sha_mpint(&ssh->exhash, s->K);
4021 SHA_Final(&ssh->exhash, s->exchange_hash);
4023 dh_cleanup(ssh->kex_ctx);
4026 debug(("Exchange hash is:\n"));
4027 dmemdump(s->exchange_hash, 20);
4030 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4032 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4033 (char *)s->exchange_hash, 20)) {
4034 bombout((ssh,"Server's host key did not match the signature supplied"));
4039 * Authenticate remote host: verify host key. (We've already
4040 * checked the signature of the exchange hash.)
4042 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4043 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4044 verify_ssh_host_key(ssh->frontend,
4045 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4046 s->keystr, s->fingerprint);
4047 if (s->first_kex) { /* don't bother logging this in rekeys */
4048 logevent("Host key fingerprint is:");
4049 logevent(s->fingerprint);
4051 sfree(s->fingerprint);
4053 ssh->hostkey->freekey(s->hkey);
4056 * Send SSH2_MSG_NEWKEYS.
4058 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4062 * Expect SSH2_MSG_NEWKEYS from server.
4065 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4066 bombout((ssh,"expected new-keys packet from server"));
4071 * Create and initialise session keys.
4073 if (ssh->cs_cipher_ctx)
4074 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4075 ssh->cscipher = s->cscipher_tobe;
4076 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4078 if (ssh->sc_cipher_ctx)
4079 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4080 ssh->sccipher = s->sccipher_tobe;
4081 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4083 if (ssh->cs_mac_ctx)
4084 ssh->csmac->free_context(ssh->cs_mac_ctx);
4085 ssh->csmac = s->csmac_tobe;
4086 ssh->cs_mac_ctx = ssh->csmac->make_context();
4088 if (ssh->sc_mac_ctx)
4089 ssh->scmac->free_context(ssh->sc_mac_ctx);
4090 ssh->scmac = s->scmac_tobe;
4091 ssh->sc_mac_ctx = ssh->scmac->make_context();
4093 if (ssh->cs_comp_ctx)
4094 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4095 ssh->cscomp = s->cscomp_tobe;
4096 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4098 if (ssh->sc_comp_ctx)
4099 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4100 ssh->sccomp = s->sccomp_tobe;
4101 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4104 * Set IVs after keys. Here we use the exchange hash from the
4105 * _first_ key exchange.
4108 unsigned char keyspace[40];
4110 memcpy(ssh->v2_session_id, s->exchange_hash,
4111 sizeof(s->exchange_hash));
4112 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4113 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4114 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4115 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4116 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4117 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4118 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4119 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4120 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4121 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4122 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4123 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4125 logeventf(ssh, "Initialised %.200s client->server encryption",
4126 ssh->cscipher->text_name);
4127 logeventf(ssh, "Initialised %.200s server->client encryption",
4128 ssh->sccipher->text_name);
4129 if (ssh->cscomp->text_name)
4130 logeventf(ssh, "Initialised %s compression",
4131 ssh->cscomp->text_name);
4132 if (ssh->sccomp->text_name)
4133 logeventf(ssh, "Initialised %s decompression",
4134 ssh->sccomp->text_name);
4137 * If this is the first key exchange phase, we must pass the
4138 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4139 * wants to see it but because it will need time to initialise
4140 * itself before it sees an actual packet. In subsequent key
4141 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4142 * it would only confuse the layer above.
4144 if (!s->first_kex) {
4150 * Now we're encrypting. Begin returning 1 to the protocol main
4151 * function so that other things can run on top of the
4152 * transport. If we ever see a KEXINIT, we must go back to the
4155 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4158 logevent("Server initiated key re-exchange");
4159 goto begin_key_exchange;
4165 * Add data to an SSH2 channel output buffer.
4167 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4170 bufchain_add(&c->v.v2.outbuffer, buf, len);
4174 * Attempt to send data on an SSH2 channel.
4176 static int ssh2_try_send(struct ssh_channel *c)
4180 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4183 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4184 if ((unsigned)len > c->v.v2.remwindow)
4185 len = c->v.v2.remwindow;
4186 if ((unsigned)len > c->v.v2.remmaxpkt)
4187 len = c->v.v2.remmaxpkt;
4188 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4189 ssh2_pkt_adduint32(ssh, c->remoteid);
4190 ssh2_pkt_addstring_start(ssh);
4191 ssh2_pkt_addstring_data(ssh, data, len);
4193 bufchain_consume(&c->v.v2.outbuffer, len);
4194 c->v.v2.remwindow -= len;
4198 * After having sent as much data as we can, return the amount
4201 return bufchain_size(&c->v.v2.outbuffer);
4205 * Potentially enlarge the window on an SSH2 channel.
4207 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4212 * Never send WINDOW_ADJUST for a channel that the remote side
4213 * already thinks it's closed; there's no point, since it won't
4214 * be sending any more data anyway.
4219 if (newwin > c->v.v2.locwindow) {
4220 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4221 ssh2_pkt_adduint32(ssh, c->remoteid);
4222 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4224 c->v.v2.locwindow = newwin;
4229 * Handle the SSH2 userauth and connection layers.
4231 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4233 struct do_ssh2_authconn_state {
4235 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4237 AUTH_KEYBOARD_INTERACTIVE
4241 AUTH_TYPE_PUBLICKEY,
4242 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4243 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4245 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4246 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4248 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4249 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4250 int kbd_inter_running;
4252 int num_prompts, curr_prompt, echo;
4257 void *publickey_blob;
4258 int publickey_bloblen;
4259 unsigned char request[5], *response, *p;
4263 char *pkblob, *alg, *commentp;
4264 int pklen, alglen, commentlen;
4265 int siglen, retlen, len;
4266 char *q, *agentreq, *ret;
4269 crState(do_ssh2_authconn_state);
4271 crBegin(ssh->do_ssh2_authconn_crstate);
4274 * Request userauth protocol, and await a response to it.
4276 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4277 ssh2_pkt_addstring(ssh, "ssh-userauth");
4279 crWaitUntilV(ispkt);
4280 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4281 bombout((ssh,"Server refused user authentication protocol"));
4286 * We repeat this whole loop, including the username prompt,
4287 * until we manage a successful authentication. If the user
4288 * types the wrong _password_, they can be sent back to the
4289 * beginning to try another username, if this is configured on.
4290 * (If they specify a username in the config, they are never
4291 * asked, even if they do give a wrong password.)
4293 * I think this best serves the needs of
4295 * - the people who have no configuration, no keys, and just
4296 * want to try repeated (username,password) pairs until they
4297 * type both correctly
4299 * - people who have keys and configuration but occasionally
4300 * need to fall back to passwords
4302 * - people with a key held in Pageant, who might not have
4303 * logged in to a particular machine before; so they want to
4304 * type a username, and then _either_ their key will be
4305 * accepted, _or_ they will type a password. If they mistype
4306 * the username they will want to be able to get back and
4309 s->username[0] = '\0';
4310 s->got_username = FALSE;
4315 if (s->got_username && !cfg.change_username) {
4317 * We got a username last time round this loop, and
4318 * with change_username turned off we don't try to get
4321 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4322 if (ssh_get_line && !ssh_getline_pw_only) {
4323 if (!ssh_get_line("login as: ",
4324 s->username, sizeof(s->username), FALSE)) {
4326 * get_line failed to get a username.
4329 logevent("No username provided. Abandoning session.");
4330 ssh->state = SSH_STATE_CLOSED;
4334 int ret; /* need not be saved across crReturn */
4335 c_write_str(ssh, "login as: ");
4337 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4339 crWaitUntilV(!ispkt);
4340 ret = process_userpass_input(ssh, in, inlen);
4344 c_write_str(ssh, "\r\n");
4346 s->username[strcspn(s->username, "\n\r")] = '\0';
4349 strncpy(s->username, cfg.username, sizeof(s->username));
4350 s->username[sizeof(s->username)-1] = '\0';
4351 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4352 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4353 c_write_str(ssh, stuff);
4357 s->got_username = TRUE;
4360 * Send an authentication request using method "none": (a)
4361 * just in case it succeeds, and (b) so that we know what
4362 * authentication methods we can usefully try next.
4364 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4366 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4367 ssh2_pkt_addstring(ssh, s->username);
4368 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4369 ssh2_pkt_addstring(ssh, "none"); /* method */
4371 s->type = AUTH_TYPE_NONE;
4373 s->we_are_in = FALSE;
4375 s->tried_pubkey_config = FALSE;
4376 s->tried_agent = FALSE;
4377 s->tried_keyb_inter = FALSE;
4378 s->kbd_inter_running = FALSE;
4379 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4382 logeventf(ssh, "Reading private key file \"%.150s\"", cfg.keyfile);
4383 keytype = key_type(cfg.keyfile);
4384 if (keytype == SSH_KEYTYPE_SSH2) {
4386 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4387 &s->publickey_bloblen);
4390 logeventf(ssh, "Unable to use this key file (%s)",
4391 key_type_to_str(keytype));
4392 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4393 " (%s)\r\n", cfg.keyfile,
4394 key_type_to_str(keytype));
4395 c_write_str(ssh, msgbuf);
4397 s->publickey_blob = NULL;
4400 s->publickey_blob = NULL;
4404 * Wait for the result of the last authentication request.
4407 crWaitUntilV(ispkt);
4408 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4412 * Don't show the banner if we're operating in
4413 * non-verbose non-interactive mode. (It's probably
4414 * a script, which means nobody will read the
4415 * banner _anyway_, and moreover the printing of
4416 * the banner will screw up processing on the
4417 * output of (say) plink.)
4419 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4420 ssh2_pkt_getstring(ssh, &banner, &size);
4422 c_write_untrusted(ssh, banner, size);
4424 crWaitUntilV(ispkt);
4426 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4427 logevent("Access granted");
4428 s->we_are_in = TRUE;
4432 if (s->kbd_inter_running &&
4433 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4435 * This is either a further set-of-prompts packet
4436 * in keyboard-interactive authentication, or it's
4437 * the same one and we came back here with `gotit'
4438 * set. In the former case, we must reset the
4439 * curr_prompt variable.
4443 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4444 bombout((ssh,"Strange packet received during authentication: type %d",
4452 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4453 * we can look at the string in it and know what we can
4454 * helpfully try next.
4456 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4459 ssh2_pkt_getstring(ssh, &methods, &methlen);
4460 s->kbd_inter_running = FALSE;
4461 if (!ssh2_pkt_getbool(ssh)) {
4463 * We have received an unequivocal Access
4464 * Denied. This can translate to a variety of
4467 * - if we'd just tried "none" authentication,
4468 * it's not worth printing anything at all
4470 * - if we'd just tried a public key _offer_,
4471 * the message should be "Server refused our
4472 * key" (or no message at all if the key
4473 * came from Pageant)
4475 * - if we'd just tried anything else, the
4476 * message really should be "Access denied".
4478 * Additionally, if we'd just tried password
4479 * authentication, we should break out of this
4480 * whole loop so as to go back to the username
4483 if (s->type == AUTH_TYPE_NONE) {
4485 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4486 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4487 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4488 c_write_str(ssh, "Server refused our key\r\n");
4489 logevent("Server refused public key");
4490 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4491 /* server declined keyboard-interactive; ignore */
4493 c_write_str(ssh, "Access denied\r\n");
4494 logevent("Access denied");
4495 if (s->type == AUTH_TYPE_PASSWORD) {
4496 s->we_are_in = FALSE;
4501 c_write_str(ssh, "Further authentication required\r\n");
4502 logevent("Further authentication required");
4506 in_commasep_string("publickey", methods, methlen);
4508 in_commasep_string("password", methods, methlen);
4509 s->can_keyb_inter = cfg.try_ki_auth &&
4510 in_commasep_string("keyboard-interactive", methods, methlen);
4514 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4517 * Most password/passphrase prompts will be
4518 * non-echoing, so we set this to 0 by default.
4519 * Exception is that some keyboard-interactive prompts
4520 * can be echoing, in which case we'll set this to 1.
4524 if (!s->method && s->can_pubkey &&
4525 agent_exists() && !s->tried_agent) {
4527 * Attempt public-key authentication using Pageant.
4532 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4533 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4535 s->tried_agent = TRUE;
4537 logevent("Pageant is running. Requesting keys.");
4539 /* Request the keys held by the agent. */
4540 PUT_32BIT(s->request, 1);
4541 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4542 agent_query(s->request, 5, &r, &s->responselen);
4543 s->response = (unsigned char *) r;
4544 if (s->response && s->responselen >= 5 &&
4545 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4546 s->p = s->response + 5;
4547 s->nkeys = GET_32BIT(s->p);
4551 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4554 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4559 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4562 s->pklen = GET_32BIT(s->p);
4564 if (s->publickey_blob &&
4565 s->pklen == s->publickey_bloblen &&
4566 !memcmp(s->p, s->publickey_blob,
4567 s->publickey_bloblen)) {
4568 logevent("This key matches configured key file");
4569 s->tried_pubkey_config = 1;
4571 s->pkblob = (char *)s->p;
4573 s->alglen = GET_32BIT(s->pkblob);
4574 s->alg = s->pkblob + 4;
4575 s->commentlen = GET_32BIT(s->p);
4577 s->commentp = (char *)s->p;
4578 s->p += s->commentlen;
4579 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4580 ssh2_pkt_addstring(ssh, s->username);
4581 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4582 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4583 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4584 ssh2_pkt_addstring_start(ssh);
4585 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4586 ssh2_pkt_addstring_start(ssh);
4587 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4590 crWaitUntilV(ispkt);
4591 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4592 logevent("Key refused");
4596 if (flags & FLAG_VERBOSE) {
4597 c_write_str(ssh, "Authenticating with "
4599 c_write(ssh, s->commentp, s->commentlen);
4600 c_write_str(ssh, "\" from agent\r\n");
4604 * Server is willing to accept the key.
4605 * Construct a SIGN_REQUEST.
4607 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4608 ssh2_pkt_addstring(ssh, s->username);
4609 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4610 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4611 ssh2_pkt_addbool(ssh, TRUE);
4612 ssh2_pkt_addstring_start(ssh);
4613 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4614 ssh2_pkt_addstring_start(ssh);
4615 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4617 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4618 s->len = 1; /* message type */
4619 s->len += 4 + s->pklen; /* key blob */
4620 s->len += 4 + s->siglen; /* data to sign */
4621 s->len += 4; /* flags */
4622 s->agentreq = smalloc(4 + s->len);
4623 PUT_32BIT(s->agentreq, s->len);
4624 s->q = s->agentreq + 4;
4625 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4626 PUT_32BIT(s->q, s->pklen);
4628 memcpy(s->q, s->pkblob, s->pklen);
4630 PUT_32BIT(s->q, s->siglen);
4632 /* Now the data to be signed... */
4633 PUT_32BIT(s->q, 20);
4635 memcpy(s->q, ssh->v2_session_id, 20);
4637 memcpy(s->q, ssh->pktout.data + 5,
4638 ssh->pktout.length - 5);
4639 s->q += ssh->pktout.length - 5;
4640 /* And finally the (zero) flags word. */
4642 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4646 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4647 logevent("Sending Pageant's response");
4648 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4650 GET_32BIT(s->ret + 5));
4656 ("Pageant failed to answer challenge");
4666 if (!s->method && s->can_pubkey && s->publickey_blob
4667 && !s->tried_pubkey_config) {
4668 unsigned char *pub_blob;
4669 char *algorithm, *comment;
4672 s->tried_pubkey_config = TRUE;
4674 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4675 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4678 * Try the public key supplied in the configuration.
4680 * First, offer the public blob to see if the server is
4681 * willing to accept it.
4684 (unsigned char *)ssh2_userkey_loadpub(cfg.keyfile,
4688 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4689 ssh2_pkt_addstring(ssh, s->username);
4690 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4691 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4692 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4693 ssh2_pkt_addstring(ssh, algorithm);
4694 ssh2_pkt_addstring_start(ssh);
4695 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4698 logevent("Offered public key"); /* FIXME */
4700 crWaitUntilV(ispkt);
4701 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4703 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4704 continue; /* key refused; give up on it */
4707 logevent("Offer of public key accepted");
4709 * Actually attempt a serious authentication using
4712 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4713 sprintf(s->pwprompt,
4714 "Passphrase for key \"%.100s\": ",
4720 c_write_str(ssh, "Authenticating with public key \"");
4721 c_write_str(ssh, comment);
4722 c_write_str(ssh, "\"\r\n");
4723 s->method = AUTH_PUBLICKEY_FILE;
4727 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4728 s->method = AUTH_KEYBOARD_INTERACTIVE;
4729 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4730 s->tried_keyb_inter = TRUE;
4732 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4733 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4735 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4736 ssh2_pkt_addstring(ssh, s->username);
4737 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4738 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4739 ssh2_pkt_addstring(ssh, ""); /* lang */
4740 ssh2_pkt_addstring(ssh, "");
4743 crWaitUntilV(ispkt);
4744 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4745 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4747 logevent("Keyboard-interactive authentication refused");
4748 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4752 s->kbd_inter_running = TRUE;
4756 if (s->kbd_inter_running) {
4757 s->method = AUTH_KEYBOARD_INTERACTIVE;
4758 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4759 s->tried_keyb_inter = TRUE;
4761 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4762 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4764 if (s->curr_prompt == 0) {
4766 * We've got a fresh USERAUTH_INFO_REQUEST.
4767 * Display header data, and start going through
4770 char *name, *inst, *lang;
4771 int name_len, inst_len, lang_len;
4773 ssh2_pkt_getstring(ssh, &name, &name_len);
4774 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4775 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4777 c_write_untrusted(ssh, name, name_len);
4778 c_write_str(ssh, "\r\n");
4781 c_write_untrusted(ssh, inst, inst_len);
4782 c_write_str(ssh, "\r\n");
4784 s->num_prompts = ssh2_pkt_getuint32(ssh);
4788 * If there are prompts remaining in the packet,
4789 * display one and get a response.
4791 if (s->curr_prompt < s->num_prompts) {
4795 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4796 if (prompt_len > 0) {
4797 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4798 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4799 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4802 "<server failed to send prompt>: ");
4804 s->echo = ssh2_pkt_getbool(ssh);
4810 if (!s->method && s->can_passwd) {
4811 s->method = AUTH_PASSWORD;
4812 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4813 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4814 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4821 if (!ssh_get_line(s->pwprompt, s->password,
4822 sizeof(s->password), TRUE)) {
4824 * get_line failed to get a password (for
4825 * example because one was supplied on the
4826 * command line which has already failed to
4829 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4830 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4831 ssh2_pkt_addstring(ssh, "No more passwords available"
4833 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4835 logevent("Unable to authenticate");
4836 connection_fatal(ssh->frontend,
4837 "Unable to authenticate");
4838 ssh->state = SSH_STATE_CLOSED;
4842 int ret; /* need not be saved across crReturn */
4843 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4846 setup_userpass_input(ssh, s->password,
4847 sizeof(s->password), s->echo);
4849 crWaitUntilV(!ispkt);
4850 ret = process_userpass_input(ssh, in, inlen);
4854 c_write_str(ssh, "\r\n");
4858 if (s->method == AUTH_PUBLICKEY_FILE) {
4860 * We have our passphrase. Now try the actual authentication.
4862 struct ssh2_userkey *key;
4864 key = ssh2_load_userkey(cfg.keyfile, s->password);
4865 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4866 if (key == SSH2_WRONG_PASSPHRASE) {
4867 c_write_str(ssh, "Wrong passphrase\r\n");
4868 s->tried_pubkey_config = FALSE;
4870 c_write_str(ssh, "Unable to load private key\r\n");
4871 s->tried_pubkey_config = TRUE;
4873 /* Send a spurious AUTH_NONE to return to the top. */
4874 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4875 ssh2_pkt_addstring(ssh, s->username);
4876 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4877 ssh2_pkt_addstring(ssh, "none"); /* method */
4879 s->type = AUTH_TYPE_NONE;
4881 unsigned char *pkblob, *sigblob, *sigdata;
4882 int pkblob_len, sigblob_len, sigdata_len;
4885 * We have loaded the private key and the server
4886 * has announced that it's willing to accept it.
4887 * Hallelujah. Generate a signature and send it.
4889 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4890 ssh2_pkt_addstring(ssh, s->username);
4891 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4892 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4893 ssh2_pkt_addbool(ssh, TRUE);
4894 ssh2_pkt_addstring(ssh, key->alg->name);
4895 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4896 ssh2_pkt_addstring_start(ssh);
4897 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
4900 * The data to be signed is:
4904 * followed by everything so far placed in the
4907 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4908 sigdata = smalloc(sigdata_len);
4909 PUT_32BIT(sigdata, 20);
4910 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4911 memcpy(sigdata + 24, ssh->pktout.data + 5,
4912 ssh->pktout.length - 5);
4913 sigblob = key->alg->sign(key->data, (char *)sigdata,
4914 sigdata_len, &sigblob_len);
4915 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4916 sigblob, sigblob_len);
4922 s->type = AUTH_TYPE_PUBLICKEY;
4924 } else if (s->method == AUTH_PASSWORD) {
4926 * We send the password packet lumped tightly together with
4927 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4928 * string long enough to make the total length of the two
4929 * packets constant. This should ensure that a passive
4930 * listener doing traffic analyis can't work out the length
4933 * For this to work, we need an assumption about the
4934 * maximum length of the password packet. I think 256 is
4935 * pretty conservative. Anyone using a password longer than
4936 * that probably doesn't have much to worry about from
4937 * people who find out how long their password is!
4939 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4940 ssh2_pkt_addstring(ssh, s->username);
4941 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4942 ssh2_pkt_addstring(ssh, "password");
4943 ssh2_pkt_addbool(ssh, FALSE);
4944 ssh2_pkt_addstring(ssh, s->password);
4945 ssh2_pkt_defer(ssh);
4947 * We'll include a string that's an exact multiple of the
4948 * cipher block size. If the cipher is NULL for some
4949 * reason, we don't do this trick at all because we gain
4952 if (ssh->cscipher) {
4955 stringlen = (256 - ssh->deferred_len);
4956 stringlen += ssh->cscipher->blksize - 1;
4957 stringlen -= (stringlen % ssh->cscipher->blksize);
4960 * Temporarily disable actual compression,
4961 * so we can guarantee to get this string
4962 * exactly the length we want it. The
4963 * compression-disabling routine should
4964 * return an integer indicating how many
4965 * bytes we should adjust our string length
4969 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4971 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4972 ssh2_pkt_addstring_start(ssh);
4973 for (i = 0; i < stringlen; i++) {
4974 char c = (char) random_byte();
4975 ssh2_pkt_addstring_data(ssh, &c, 1);
4977 ssh2_pkt_defer(ssh);
4979 ssh_pkt_defersend(ssh);
4980 logevent("Sent password");
4981 s->type = AUTH_TYPE_PASSWORD;
4982 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4983 if (s->curr_prompt == 0) {
4984 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4985 ssh2_pkt_adduint32(ssh, s->num_prompts);
4987 if (s->need_pw) { /* only add pw if we just got one! */
4988 ssh2_pkt_addstring(ssh, s->password);
4989 memset(s->password, 0, sizeof(s->password));
4992 if (s->curr_prompt >= s->num_prompts) {
4996 * If there are prompts remaining, we set
4997 * `gotit' so that we won't attempt to get
4998 * another packet. Then we go back round the
4999 * loop and will end up retrieving another
5000 * prompt out of the existing packet. Funky or
5005 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5007 c_write_str(ssh, "No supported authentication methods"
5008 " left to try!\r\n");
5009 logevent("No supported authentications offered."
5011 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5012 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5013 ssh2_pkt_addstring(ssh, "No supported authentication"
5014 " methods available");
5015 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5017 ssh->state = SSH_STATE_CLOSED;
5021 } while (!s->we_are_in);
5024 * Now we're authenticated for the connection protocol. The
5025 * connection protocol will automatically have started at this
5026 * point; there's no need to send SERVICE_REQUEST.
5030 * So now create a channel with a session in it.
5032 ssh->channels = newtree234(ssh_channelcmp);
5033 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5034 ssh->mainchan->ssh = ssh;
5035 ssh->mainchan->localid = alloc_channel_id(ssh);
5036 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5037 ssh2_pkt_addstring(ssh, "session");
5038 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5039 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5040 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5041 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5043 crWaitUntilV(ispkt);
5044 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5045 bombout((ssh,"Server refused to open a session"));
5047 /* FIXME: error data comes back in FAILURE packet */
5049 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5050 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5053 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5054 ssh->mainchan->type = CHAN_MAINSESSION;
5055 ssh->mainchan->closes = 0;
5056 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5057 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5058 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5059 add234(ssh->channels, ssh->mainchan);
5060 logevent("Opened channel for session");
5063 * Potentially enable X11 forwarding.
5065 if (cfg.x11_forward) {
5066 char proto[20], data[64];
5067 logevent("Requesting X11 forwarding");
5068 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5069 data, sizeof(data));
5070 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5071 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5072 ssh2_pkt_addstring(ssh, "x11-req");
5073 ssh2_pkt_addbool(ssh, 1); /* want reply */
5074 ssh2_pkt_addbool(ssh, 0); /* many connections */
5075 ssh2_pkt_addstring(ssh, proto);
5076 ssh2_pkt_addstring(ssh, data);
5077 ssh2_pkt_adduint32(ssh, x11_get_screen_number(cfg.x11_display));
5081 crWaitUntilV(ispkt);
5082 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5083 unsigned i = ssh2_pkt_getuint32(ssh);
5084 struct ssh_channel *c;
5085 c = find234(ssh->channels, &i, ssh_channelfind);
5087 continue; /* nonexistent channel */
5088 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5090 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5092 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5093 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5094 bombout((ssh,"Unexpected response to X11 forwarding request:"
5095 " packet type %d", ssh->pktin.type));
5098 logevent("X11 forwarding refused");
5100 logevent("X11 forwarding enabled");
5101 ssh->X11_fwd_enabled = TRUE;
5106 * Enable port forwardings.
5111 int sport,dport,sserv,dserv;
5112 char sports[256], dports[256], saddr[256], host[256];
5114 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5115 /* Add port forwardings. */
5116 ssh->portfwd_strptr = cfg.portfwd;
5117 while (*ssh->portfwd_strptr) {
5118 type = *ssh->portfwd_strptr++;
5121 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5122 if (*ssh->portfwd_strptr == ':') {
5124 * We've seen a colon in the middle of the
5125 * source port number. This means that
5126 * everything we've seen until now is the
5127 * source _address_, so we'll move it into
5128 * saddr and start sports from the beginning
5131 ssh->portfwd_strptr++;
5133 strcpy(saddr, sports);
5136 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5139 if (*ssh->portfwd_strptr == '\t')
5140 ssh->portfwd_strptr++;
5142 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5143 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5146 if (*ssh->portfwd_strptr == ':')
5147 ssh->portfwd_strptr++;
5149 while (*ssh->portfwd_strptr) {
5150 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5153 ssh->portfwd_strptr++;
5154 dport = atoi(dports);
5158 dport = net_service_lookup(dports);
5160 logeventf(ssh, "Service lookup failed for destination"
5161 " port \"%s\"", dports);
5164 sport = atoi(sports);
5168 sport = net_service_lookup(sports);
5170 logeventf(ssh, "Service lookup failed for source"
5171 " port \"%s\"", sports);
5174 if (sport && dport) {
5176 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5178 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5179 " forwarding to %s:%.*s%.*s%d%.*s",
5180 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5181 (int)(*saddr?1:0), ":",
5182 (int)(sserv ? strlen(sports) : 0), sports,
5183 sserv, "(", sport, sserv, ")",
5185 (int)(dserv ? strlen(dports) : 0), dports,
5186 dserv, "(", dport, dserv, ")");
5188 struct ssh_rportfwd *pf;
5189 pf = smalloc(sizeof(*pf));
5190 strcpy(pf->dhost, host);
5193 if (add234(ssh->rportfwds, pf) != pf) {
5194 logeventf(ssh, "Duplicate remote port forwarding"
5195 " to %s:%d", host, dport);
5198 logeventf(ssh, "Requesting remote port "
5199 "%.*s%.*s%.*s%.*s%d%.*s"
5200 " forward to %s:%.*s%.*s%d%.*s",
5201 (int)(*saddr?strlen(saddr):0),
5203 (int)(*saddr?1:0), ":",
5204 (int)(sserv ? strlen(sports) : 0), sports,
5205 sserv, "(", sport, sserv, ")",
5207 (int)(dserv ? strlen(dports) : 0), dports,
5208 dserv, "(", dport, dserv, ")");
5209 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5210 ssh2_pkt_addstring(ssh, "tcpip-forward");
5211 ssh2_pkt_addbool(ssh, 1);/* want reply */
5213 ssh2_pkt_addstring(ssh, saddr);
5214 if (cfg.rport_acceptall)
5215 ssh2_pkt_addstring(ssh, "0.0.0.0");
5217 ssh2_pkt_addstring(ssh, "127.0.0.1");
5218 ssh2_pkt_adduint32(ssh, sport);
5222 crWaitUntilV(ispkt);
5223 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5224 unsigned i = ssh2_pkt_getuint32(ssh);
5225 struct ssh_channel *c;
5226 c = find234(ssh->channels, &i, ssh_channelfind);
5228 continue;/* nonexistent channel */
5229 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5231 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5233 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5234 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5235 bombout((ssh,"Unexpected response to port "
5236 "forwarding request: packet type %d",
5240 logevent("Server refused this port forwarding");
5242 logevent("Remote port forwarding enabled");
5251 * Potentially enable agent forwarding.
5253 if (cfg.agentfwd && agent_exists()) {
5254 logevent("Requesting OpenSSH-style agent forwarding");
5255 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5256 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5257 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5258 ssh2_pkt_addbool(ssh, 1); /* want reply */
5262 crWaitUntilV(ispkt);
5263 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5264 unsigned i = ssh2_pkt_getuint32(ssh);
5265 struct ssh_channel *c;
5266 c = find234(ssh->channels, &i, ssh_channelfind);
5268 continue; /* nonexistent channel */
5269 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5271 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5273 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5274 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5275 bombout((ssh,"Unexpected response to agent forwarding request:"
5276 " packet type %d", ssh->pktin.type));
5279 logevent("Agent forwarding refused");
5281 logevent("Agent forwarding enabled");
5282 ssh->agentfwd_enabled = TRUE;
5287 * Now allocate a pty for the session.
5290 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5291 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5292 ssh2_pkt_addstring(ssh, "pty-req");
5293 ssh2_pkt_addbool(ssh, 1); /* want reply */
5294 ssh2_pkt_addstring(ssh, cfg.termtype);
5295 ssh2_pkt_adduint32(ssh, ssh->term_width);
5296 ssh2_pkt_adduint32(ssh, ssh->term_height);
5297 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5298 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5299 ssh2_pkt_addstring_start(ssh);
5300 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5302 ssh->state = SSH_STATE_INTERMED;
5305 crWaitUntilV(ispkt);
5306 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5307 unsigned i = ssh2_pkt_getuint32(ssh);
5308 struct ssh_channel *c;
5309 c = find234(ssh->channels, &i, ssh_channelfind);
5311 continue; /* nonexistent channel */
5312 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5314 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5316 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5317 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5318 bombout((ssh,"Unexpected response to pty request:"
5319 " packet type %d", ssh->pktin.type));
5322 c_write_str(ssh, "Server refused to allocate pty\r\n");
5323 ssh->editing = ssh->echoing = 1;
5325 logevent("Allocated pty");
5328 ssh->editing = ssh->echoing = 1;
5332 * Start a shell or a remote command. We may have to attempt
5333 * this twice if the config data has provided a second choice
5340 if (ssh->fallback_cmd) {
5341 subsys = cfg.ssh_subsys2;
5342 cmd = cfg.remote_cmd_ptr2;
5344 subsys = cfg.ssh_subsys;
5345 cmd = cfg.remote_cmd_ptr;
5348 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5349 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5351 ssh2_pkt_addstring(ssh, "subsystem");
5352 ssh2_pkt_addbool(ssh, 1); /* want reply */
5353 ssh2_pkt_addstring(ssh, cmd);
5355 ssh2_pkt_addstring(ssh, "exec");
5356 ssh2_pkt_addbool(ssh, 1); /* want reply */
5357 ssh2_pkt_addstring(ssh, cmd);
5359 ssh2_pkt_addstring(ssh, "shell");
5360 ssh2_pkt_addbool(ssh, 1); /* want reply */
5364 crWaitUntilV(ispkt);
5365 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5366 unsigned i = ssh2_pkt_getuint32(ssh);
5367 struct ssh_channel *c;
5368 c = find234(ssh->channels, &i, ssh_channelfind);
5370 continue; /* nonexistent channel */
5371 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5373 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5374 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5375 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5376 bombout((ssh,"Unexpected response to shell/command request:"
5377 " packet type %d", ssh->pktin.type));
5381 * We failed to start the command. If this is the
5382 * fallback command, we really are finished; if it's
5383 * not, and if the fallback command exists, try falling
5384 * back to it before complaining.
5386 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5387 logevent("Primary command failed; attempting fallback");
5388 ssh->fallback_cmd = TRUE;
5391 bombout((ssh,"Server refused to start a shell/command"));
5394 logevent("Started a shell/command");
5399 ssh->state = SSH_STATE_SESSION;
5400 if (ssh->size_needed)
5401 ssh_size(ssh, ssh->term_width, ssh->term_height);
5402 if (ssh->eof_needed)
5403 ssh_special(ssh, TS_EOF);
5409 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5413 s->try_send = FALSE;
5415 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5416 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5419 unsigned i = ssh2_pkt_getuint32(ssh);
5420 struct ssh_channel *c;
5421 c = find234(ssh->channels, &i, ssh_channelfind);
5423 continue; /* nonexistent channel */
5424 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5425 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5426 continue; /* extended but not stderr */
5427 ssh2_pkt_getstring(ssh, &data, &length);
5430 c->v.v2.locwindow -= length;
5432 case CHAN_MAINSESSION:
5434 from_backend(ssh->frontend, ssh->pktin.type ==
5435 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5439 bufsize = x11_send(c->u.x11.s, data, length);
5442 bufsize = pfd_send(c->u.pfd.s, data, length);
5445 while (length > 0) {
5446 if (c->u.a.lensofar < 4) {
5447 int l = min(4 - c->u.a.lensofar, length);
5448 memcpy(c->u.a.msglen + c->u.a.lensofar,
5452 c->u.a.lensofar += l;
5454 if (c->u.a.lensofar == 4) {
5456 4 + GET_32BIT(c->u.a.msglen);
5457 c->u.a.message = smalloc(c->u.a.totallen);
5458 memcpy(c->u.a.message, c->u.a.msglen, 4);
5460 if (c->u.a.lensofar >= 4 && length > 0) {
5462 min(c->u.a.totallen - c->u.a.lensofar,
5464 memcpy(c->u.a.message + c->u.a.lensofar,
5468 c->u.a.lensofar += l;
5470 if (c->u.a.lensofar == c->u.a.totallen) {
5471 void *reply, *sentreply;
5473 agent_query(c->u.a.message,
5474 c->u.a.totallen, &reply,
5479 /* Fake SSH_AGENT_FAILURE. */
5480 sentreply = "\0\0\0\1\5";
5483 ssh2_add_channel_data(c, sentreply, replylen);
5487 sfree(c->u.a.message);
5488 c->u.a.lensofar = 0;
5495 * If we are not buffering too much data,
5496 * enlarge the window again at the remote side.
5498 if (bufsize < OUR_V2_WINSIZE)
5499 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5501 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5502 unsigned i = ssh2_pkt_getuint32(ssh);
5503 struct ssh_channel *c;
5505 c = find234(ssh->channels, &i, ssh_channelfind);
5507 continue; /* nonexistent channel */
5509 if (c->type == CHAN_X11) {
5511 * Remote EOF on an X11 channel means we should
5512 * wrap up and close the channel ourselves.
5514 x11_close(c->u.x11.s);
5516 } else if (c->type == CHAN_AGENT) {
5518 } else if (c->type == CHAN_SOCKDATA) {
5519 pfd_close(c->u.pfd.s);
5522 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5523 unsigned i = ssh2_pkt_getuint32(ssh);
5524 struct ssh_channel *c;
5526 c = find234(ssh->channels, &i, ssh_channelfind);
5527 if (!c || ((int)c->remoteid) == -1) {
5528 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5529 c ? "half-open" : "nonexistent", i));
5531 /* Do pre-close processing on the channel. */
5533 case CHAN_MAINSESSION:
5534 break; /* nothing to see here, move along */
5536 if (c->u.x11.s != NULL)
5537 x11_close(c->u.x11.s);
5544 if (c->u.pfd.s != NULL)
5545 pfd_close(c->u.pfd.s);
5549 if (c->closes == 0) {
5550 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5551 ssh2_pkt_adduint32(ssh, c->remoteid);
5554 del234(ssh->channels, c);
5555 bufchain_clear(&c->v.v2.outbuffer);
5559 * See if that was the last channel left open.
5561 if (count234(ssh->channels) == 0) {
5564 * We used to send SSH_MSG_DISCONNECT here,
5565 * because I'd believed that _every_ conforming
5566 * SSH2 connection had to end with a disconnect
5567 * being sent by at least one side; apparently
5568 * I was wrong and it's perfectly OK to
5569 * unceremoniously slam the connection shut
5570 * when you're done, and indeed OpenSSH feels
5571 * this is more polite than sending a
5572 * DISCONNECT. So now we don't.
5574 logevent("All channels closed. Disconnecting");
5575 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5576 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5577 ssh2_pkt_addstring(ssh, "All open channels closed");
5578 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5581 ssh->state = SSH_STATE_CLOSED;
5584 continue; /* remote sends close; ignore (FIXME) */
5585 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5586 unsigned i = ssh2_pkt_getuint32(ssh);
5587 struct ssh_channel *c;
5588 c = find234(ssh->channels, &i, ssh_channelfind);
5590 continue; /* nonexistent channel */
5591 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5593 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5594 unsigned i = ssh2_pkt_getuint32(ssh);
5595 struct ssh_channel *c;
5596 c = find234(ssh->channels, &i, ssh_channelfind);
5598 continue; /* nonexistent channel */
5599 if (c->type != CHAN_SOCKDATA_DORMANT)
5600 continue; /* dunno why they're confirming this */
5601 c->remoteid = ssh2_pkt_getuint32(ssh);
5602 c->type = CHAN_SOCKDATA;
5603 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5604 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5606 pfd_confirm(c->u.pfd.s);
5609 * We have a pending close on this channel,
5610 * which we decided on before the server acked
5611 * the channel open. So now we know the
5612 * remoteid, we can close it again.
5614 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5615 ssh2_pkt_adduint32(ssh, c->remoteid);
5618 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5619 unsigned i = ssh2_pkt_getuint32(ssh);
5620 struct ssh_channel *c;
5621 c = find234(ssh->channels, &i, ssh_channelfind);
5623 continue; /* nonexistent channel */
5624 if (c->type != CHAN_SOCKDATA_DORMANT)
5625 continue; /* dunno why they're failing this */
5627 logevent("Forwarded connection refused by server");
5629 pfd_close(c->u.pfd.s);
5631 del234(ssh->channels, c);
5633 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5636 int typelen, want_reply;
5637 struct ssh_channel *c;
5639 localid = ssh2_pkt_getuint32(ssh);
5640 ssh2_pkt_getstring(ssh, &type, &typelen);
5641 want_reply = ssh2_pkt_getbool(ssh);
5644 * First, check that the channel exists. Otherwise,
5645 * we can instantly disconnect with a rude message.
5647 c = find234(ssh->channels, &localid, ssh_channelfind);
5650 sprintf(buf, "Received channel request for nonexistent"
5651 " channel %d", localid);
5653 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5654 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5655 ssh2_pkt_addstring(ssh, buf);
5656 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5658 connection_fatal("%s", buf);
5659 ssh->state = SSH_STATE_CLOSED;
5664 * Having got the channel number, we now look at
5665 * the request type string to see if it's something
5668 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5669 c == ssh->mainchan) {
5670 /* We recognise "exit-status" on the primary channel. */
5672 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5673 sprintf(buf, "Server sent command exit status %d",
5677 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5678 ssh2_pkt_adduint32(ssh, c->remoteid);
5683 * This is a channel request we don't know
5684 * about, so we now either ignore the request
5685 * or respond with CHANNEL_FAILURE, depending
5689 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5690 ssh2_pkt_adduint32(ssh, c->remoteid);
5694 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5696 int typelen, want_reply;
5698 ssh2_pkt_getstring(ssh, &type, &typelen);
5699 want_reply = ssh2_pkt_getbool(ssh);
5702 * We currently don't support any global requests
5703 * at all, so we either ignore the request or
5704 * respond with REQUEST_FAILURE, depending on
5708 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5711 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5715 struct ssh_channel *c;
5716 unsigned remid, winsize, pktsize;
5717 ssh2_pkt_getstring(ssh, &type, &typelen);
5718 c = smalloc(sizeof(struct ssh_channel));
5721 remid = ssh2_pkt_getuint32(ssh);
5722 winsize = ssh2_pkt_getuint32(ssh);
5723 pktsize = ssh2_pkt_getuint32(ssh);
5725 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5726 if (!ssh->X11_fwd_enabled)
5727 error = "X11 forwarding is not enabled";
5728 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5729 ssh->x11auth) != NULL) {
5730 error = "Unable to open an X11 connection";
5734 } else if (typelen == 15 &&
5735 !memcmp(type, "forwarded-tcpip", 15)) {
5736 struct ssh_rportfwd pf, *realpf;
5739 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5740 pf.sport = ssh2_pkt_getuint32(ssh);
5741 realpf = find234(ssh->rportfwds, &pf, NULL);
5742 if (realpf == NULL) {
5743 error = "Remote port is not recognised";
5745 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5747 logeventf(ssh, "Received remote port open request"
5748 " for %s:%d", realpf->dhost, realpf->dport);
5750 logeventf(ssh, "Port open failed: %s", e);
5751 error = "Port open failed";
5753 logevent("Forwarded port opened successfully");
5754 c->type = CHAN_SOCKDATA;
5757 } else if (typelen == 22 &&
5758 !memcmp(type, "auth-agent@openssh.com", 3)) {
5759 if (!ssh->agentfwd_enabled)
5760 error = "Agent forwarding is not enabled";
5762 c->type = CHAN_AGENT; /* identify channel type */
5763 c->u.a.lensofar = 0;
5766 error = "Unsupported channel type requested";
5769 c->remoteid = remid;
5771 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5772 ssh2_pkt_adduint32(ssh, c->remoteid);
5773 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5774 ssh2_pkt_addstring(ssh, error);
5775 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5779 c->localid = alloc_channel_id(ssh);
5781 c->v.v2.locwindow = OUR_V2_WINSIZE;
5782 c->v.v2.remwindow = winsize;
5783 c->v.v2.remmaxpkt = pktsize;
5784 bufchain_init(&c->v.v2.outbuffer);
5785 add234(ssh->channels, c);
5786 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5787 ssh2_pkt_adduint32(ssh, c->remoteid);
5788 ssh2_pkt_adduint32(ssh, c->localid);
5789 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5790 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5794 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5799 * We have spare data. Add it to the channel buffer.
5801 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5806 struct ssh_channel *c;
5808 * Try to send data on all channels if we can.
5810 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5811 int bufsize = ssh2_try_send(c);
5814 case CHAN_MAINSESSION:
5815 /* stdin need not receive an unthrottle
5816 * notification since it will be polled */
5819 x11_unthrottle(c->u.x11.s);
5822 /* agent sockets are request/response and need no
5823 * buffer management */
5826 pfd_unthrottle(c->u.pfd.s);
5838 * Handle the top-level SSH2 protocol.
5840 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5842 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5844 do_ssh2_authconn(ssh, in, inlen, ispkt);
5848 * Called to set up the connection.
5850 * Returns an error message, or NULL on success.
5852 static char *ssh_init(void *frontend_handle, void **backend_handle,
5853 char *host, int port, char **realhost, int nodelay)
5858 ssh = smalloc(sizeof(*ssh));
5861 ssh->v1_cipher_ctx = NULL;
5862 ssh->crcda_ctx = NULL;
5863 ssh->cscipher = NULL;
5864 ssh->cs_cipher_ctx = NULL;
5865 ssh->sccipher = NULL;
5866 ssh->sc_cipher_ctx = NULL;
5868 ssh->cs_mac_ctx = NULL;
5870 ssh->sc_mac_ctx = NULL;
5872 ssh->cs_comp_ctx = NULL;
5874 ssh->sc_comp_ctx = NULL;
5876 ssh->hostkey = NULL;
5878 ssh->state = SSH_STATE_PREPACKET;
5879 ssh->size_needed = FALSE;
5880 ssh->eof_needed = FALSE;
5884 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5885 ssh->pktin = ssh->pktout = empty;
5887 ssh->deferred_send_data = NULL;
5888 ssh->deferred_len = 0;
5889 ssh->deferred_size = 0;
5890 ssh->fallback_cmd = 0;
5892 ssh->x11auth = NULL;
5893 ssh->v1_compressing = FALSE;
5894 ssh->v2_outgoing_sequence = 0;
5895 ssh->ssh1_rdpkt_crstate = 0;
5896 ssh->ssh2_rdpkt_crstate = 0;
5897 ssh->do_ssh_init_crstate = 0;
5898 ssh->ssh_gotdata_crstate = 0;
5899 ssh->ssh1_protocol_crstate = 0;
5900 ssh->do_ssh1_login_crstate = 0;
5901 ssh->do_ssh2_transport_crstate = 0;
5902 ssh->do_ssh2_authconn_crstate = 0;
5903 ssh->do_ssh_init_state = NULL;
5904 ssh->do_ssh1_login_state = NULL;
5905 ssh->do_ssh2_transport_state = NULL;
5906 ssh->do_ssh2_authconn_state = NULL;
5907 ssh->mainchan = NULL;
5908 ssh->throttled_all = 0;
5909 ssh->v1_stdout_throttling = 0;
5911 *backend_handle = ssh;
5914 if (crypto_startup() == 0)
5915 return "Microsoft high encryption pack not installed!";
5918 ssh->frontend = frontend_handle;
5919 ssh->term_width = cfg.width;
5920 ssh->term_height = cfg.height;
5925 ssh->v1_throttle_count = 0;
5926 ssh->overall_bufsize = 0;
5927 ssh->fallback_cmd = 0;
5929 p = connect_to_host(ssh, host, port, realhost, nodelay);
5937 * Called to send data down the Telnet connection.
5939 static int ssh_send(void *handle, char *buf, int len)
5941 Ssh ssh = (Ssh) handle;
5943 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5946 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5948 return ssh_sendbuffer(ssh);
5952 * Called to query the current amount of buffered stdin data.
5954 static int ssh_sendbuffer(void *handle)
5956 Ssh ssh = (Ssh) handle;
5959 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5963 * If the SSH socket itself has backed up, add the total backup
5964 * size on that to any individual buffer on the stdin channel.
5967 if (ssh->throttled_all)
5968 override_value = ssh->overall_bufsize;
5970 if (ssh->version == 1) {
5971 return override_value;
5972 } else if (ssh->version == 2) {
5973 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5974 return override_value;
5976 return (override_value +
5977 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5984 * Called to set the size of the window from SSH's POV.
5986 static void ssh_size(void *handle, int width, int height)
5988 Ssh ssh = (Ssh) handle;
5990 ssh->term_width = width;
5991 ssh->term_height = height;
5993 switch (ssh->state) {
5994 case SSH_STATE_BEFORE_SIZE:
5995 case SSH_STATE_PREPACKET:
5996 case SSH_STATE_CLOSED:
5997 break; /* do nothing */
5998 case SSH_STATE_INTERMED:
5999 ssh->size_needed = TRUE; /* buffer for later */
6001 case SSH_STATE_SESSION:
6003 if (ssh->version == 1) {
6004 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6005 PKT_INT, ssh->term_height,
6006 PKT_INT, ssh->term_width,
6007 PKT_INT, 0, PKT_INT, 0, PKT_END);
6009 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6010 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6011 ssh2_pkt_addstring(ssh, "window-change");
6012 ssh2_pkt_addbool(ssh, 0);
6013 ssh2_pkt_adduint32(ssh, ssh->term_width);
6014 ssh2_pkt_adduint32(ssh, ssh->term_height);
6015 ssh2_pkt_adduint32(ssh, 0);
6016 ssh2_pkt_adduint32(ssh, 0);
6025 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6026 * can send an EOF and collect resulting output (e.g. `plink
6029 static void ssh_special(void *handle, Telnet_Special code)
6031 Ssh ssh = (Ssh) handle;
6033 if (code == TS_EOF) {
6034 if (ssh->state != SSH_STATE_SESSION) {
6036 * Buffer the EOF in case we are pre-SESSION, so we can
6037 * send it as soon as we reach SESSION.
6040 ssh->eof_needed = TRUE;
6043 if (ssh->version == 1) {
6044 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6046 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6047 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6050 logevent("Sent EOF message");
6051 } else if (code == TS_PING) {
6052 if (ssh->state == SSH_STATE_CLOSED
6053 || ssh->state == SSH_STATE_PREPACKET) return;
6054 if (ssh->version == 1) {
6055 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6056 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6058 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6059 ssh2_pkt_addstring_start(ssh);
6067 void *new_sock_channel(void *handle, Socket s)
6069 Ssh ssh = (Ssh) handle;
6070 struct ssh_channel *c;
6071 c = smalloc(sizeof(struct ssh_channel));
6075 c->remoteid = -1; /* to be set when open confirmed */
6076 c->localid = alloc_channel_id(ssh);
6078 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6080 bufchain_init(&c->v.v2.outbuffer);
6081 add234(ssh->channels, c);
6087 * This is called when stdout/stderr (the entity to which
6088 * from_backend sends data) manages to clear some backlog.
6090 static void ssh_unthrottle(void *handle, int bufsize)
6092 Ssh ssh = (Ssh) handle;
6093 if (ssh->version == 1) {
6094 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6095 ssh->v1_stdout_throttling = 0;
6096 ssh1_throttle(ssh, -1);
6099 if (ssh->mainchan && ssh->mainchan->closes == 0)
6100 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6104 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6106 struct ssh_channel *c = (struct ssh_channel *)channel;
6109 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6111 if (ssh->version == 1) {
6112 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6113 PKT_INT, c->localid,
6116 //PKT_STR, <org:orgport>,
6119 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6120 ssh2_pkt_addstring(ssh, "direct-tcpip");
6121 ssh2_pkt_adduint32(ssh, c->localid);
6122 c->v.v2.locwindow = OUR_V2_WINSIZE;
6123 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6124 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6125 ssh2_pkt_addstring(ssh, hostname);
6126 ssh2_pkt_adduint32(ssh, port);
6128 * We make up values for the originator data; partly it's
6129 * too much hassle to keep track, and partly I'm not
6130 * convinced the server should be told details like that
6131 * about my local network configuration.
6133 ssh2_pkt_addstring(ssh, "client-side-connection");
6134 ssh2_pkt_adduint32(ssh, 0);
6140 static Socket ssh_socket(void *handle)
6142 Ssh ssh = (Ssh) handle;
6146 static int ssh_sendok(void *handle)
6148 Ssh ssh = (Ssh) handle;
6149 return ssh->send_ok;
6152 static int ssh_ldisc(void *handle, int option)
6154 Ssh ssh = (Ssh) handle;
6155 if (option == LD_ECHO)
6156 return ssh->echoing;
6157 if (option == LD_EDIT)
6158 return ssh->editing;
6162 static void ssh_provide_ldisc(void *handle, void *ldisc)
6164 Ssh ssh = (Ssh) handle;
6168 static void ssh_provide_logctx(void *handle, void *logctx)
6170 Ssh ssh = (Ssh) handle;
6171 ssh->logctx = logctx;
6174 static int ssh_return_exitcode(void *handle)
6176 Ssh ssh = (Ssh) handle;
6177 return ssh->exitcode;
6181 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6182 * that fails. This variable is the means by which scp.c can reach
6183 * into the SSH code and find out which one it got.
6185 extern int ssh_fallback_cmd(void *handle)
6187 Ssh ssh = (Ssh) handle;
6188 return ssh->fallback_cmd;
6191 Backend ssh_backend = {
6198 ssh_return_exitcode,