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 == '\012')
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, "\012");
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, "\012");
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 x11_get_real_auth(ssh->x11auth, cfg.x11_display);
3023 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3024 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3025 PKT_STR, proto, PKT_STR, data,
3026 PKT_INT, x11_get_screen_number(cfg.x11_display),
3029 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3030 PKT_STR, proto, PKT_STR, data, PKT_END);
3035 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3036 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3037 bombout((ssh,"Protocol confusion"));
3039 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3040 logevent("X11 forwarding refused");
3042 logevent("X11 forwarding enabled");
3043 ssh->X11_fwd_enabled = TRUE;
3050 int sport,dport,sserv,dserv;
3051 char sports[256], dports[256], saddr[256], host[256];
3053 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3054 /* Add port forwardings. */
3055 ssh->portfwd_strptr = cfg.portfwd;
3056 while (*ssh->portfwd_strptr) {
3057 type = *ssh->portfwd_strptr++;
3060 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3061 if (*ssh->portfwd_strptr == ':') {
3063 * We've seen a colon in the middle of the
3064 * source port number. This means that
3065 * everything we've seen until now is the
3066 * source _address_, so we'll move it into
3067 * saddr and start sports from the beginning
3070 ssh->portfwd_strptr++;
3072 strcpy(saddr, sports);
3075 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3078 if (*ssh->portfwd_strptr == '\t')
3079 ssh->portfwd_strptr++;
3081 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3082 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3085 if (*ssh->portfwd_strptr == ':')
3086 ssh->portfwd_strptr++;
3088 while (*ssh->portfwd_strptr) {
3089 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3092 ssh->portfwd_strptr++;
3093 dport = atoi(dports);
3097 dport = net_service_lookup(dports);
3099 logeventf(ssh, "Service lookup failed for"
3100 " destination port \"%s\"", dports);
3103 sport = atoi(sports);
3107 sport = net_service_lookup(sports);
3109 logeventf(ssh, "Service lookup failed for source"
3110 " port \"%s\"", sports);
3113 if (sport && dport) {
3115 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3117 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3118 " forwarding to %s:%.*s%.*s%d%.*s",
3119 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3120 (int)(*saddr?1:0), ":",
3121 (int)(sserv ? strlen(sports) : 0), sports,
3122 sserv, "(", sport, sserv, ")",
3124 (int)(dserv ? strlen(dports) : 0), dports,
3125 dserv, "(", dport, dserv, ")");
3127 struct ssh_rportfwd *pf;
3128 pf = smalloc(sizeof(*pf));
3129 strcpy(pf->dhost, host);
3133 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3136 if (add234(ssh->rportfwds, pf) != pf) {
3138 "Duplicate remote port forwarding to %s:%d",
3142 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3143 " forward to %s:%.*s%.*s%d%.*s",
3144 (int)(sserv ? strlen(sports) : 0), sports,
3145 sserv, "(", sport, sserv, ")",
3147 (int)(dserv ? strlen(dports) : 0), dports,
3148 dserv, "(", dport, dserv, ")");
3149 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3157 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3158 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3159 bombout((ssh,"Protocol confusion"));
3161 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3162 c_write_str(ssh, "Server refused port"
3165 logevent("Remote port forwarding enabled");
3173 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3174 PKT_STR, cfg.termtype,
3175 PKT_INT, ssh->term_height,
3176 PKT_INT, ssh->term_width,
3177 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3178 ssh->state = SSH_STATE_INTERMED;
3182 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3183 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3184 bombout((ssh,"Protocol confusion"));
3186 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3187 c_write_str(ssh, "Server refused to allocate pty\r\n");
3188 ssh->editing = ssh->echoing = 1;
3190 logevent("Allocated pty");
3192 ssh->editing = ssh->echoing = 1;
3195 if (cfg.compression) {
3196 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3200 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3201 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3202 bombout((ssh,"Protocol confusion"));
3204 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3205 c_write_str(ssh, "Server refused to compress\r\n");
3207 logevent("Started compression");
3208 ssh->v1_compressing = TRUE;
3209 ssh->cs_comp_ctx = zlib_compress_init();
3210 logevent("Initialised zlib (RFC1950) compression");
3211 ssh->sc_comp_ctx = zlib_decompress_init();
3212 logevent("Initialised zlib (RFC1950) decompression");
3216 * Start the shell or command.
3218 * Special case: if the first-choice command is an SSH2
3219 * subsystem (hence not usable here) and the second choice
3220 * exists, we fall straight back to that.
3223 char *cmd = cfg.remote_cmd_ptr;
3225 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3226 cmd = cfg.remote_cmd_ptr2;
3227 ssh->fallback_cmd = TRUE;
3230 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3232 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3233 logevent("Started session");
3236 ssh->state = SSH_STATE_SESSION;
3237 if (ssh->size_needed)
3238 ssh_size(ssh, ssh->term_width, ssh->term_height);
3239 if (ssh->eof_needed)
3240 ssh_special(ssh, TS_EOF);
3243 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3245 ssh->channels = newtree234(ssh_channelcmp);
3249 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3250 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3251 long len = GET_32BIT(ssh->pktin.body);
3253 from_backend(ssh->frontend,
3254 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3255 (char *)(ssh->pktin.body) + 4, len);
3256 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3257 ssh->v1_stdout_throttling = 1;
3258 ssh1_throttle(ssh, +1);
3260 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3261 ssh->state = SSH_STATE_CLOSED;
3262 logevent("Received disconnect request");
3264 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3265 /* Remote side is trying to open a channel to talk to our
3266 * X-Server. Give them back a local channel number. */
3267 struct ssh_channel *c;
3269 logevent("Received X11 connect request");
3270 /* Refuse if X11 forwarding is disabled. */
3271 if (!ssh->X11_fwd_enabled) {
3272 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3273 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3274 logevent("Rejected X11 connect request");
3276 c = smalloc(sizeof(struct ssh_channel));
3279 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3280 ssh->x11auth) != NULL) {
3281 logevent("opening X11 forward connection failed");
3283 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3284 PKT_INT, GET_32BIT(ssh->pktin.body),
3288 ("opening X11 forward connection succeeded");
3289 c->remoteid = GET_32BIT(ssh->pktin.body);
3290 c->localid = alloc_channel_id(ssh);
3292 c->v.v1.throttling = 0;
3293 c->type = CHAN_X11; /* identify channel type */
3294 add234(ssh->channels, c);
3295 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3296 PKT_INT, c->remoteid, PKT_INT,
3297 c->localid, PKT_END);
3298 logevent("Opened X11 forward channel");
3301 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3302 /* Remote side is trying to open a channel to talk to our
3303 * agent. Give them back a local channel number. */
3304 struct ssh_channel *c;
3306 /* Refuse if agent forwarding is disabled. */
3307 if (!ssh->agentfwd_enabled) {
3308 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3309 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3311 c = smalloc(sizeof(struct ssh_channel));
3313 c->remoteid = GET_32BIT(ssh->pktin.body);
3314 c->localid = alloc_channel_id(ssh);
3316 c->v.v1.throttling = 0;
3317 c->type = CHAN_AGENT; /* identify channel type */
3318 c->u.a.lensofar = 0;
3319 add234(ssh->channels, c);
3320 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3321 PKT_INT, c->remoteid, PKT_INT, c->localid,
3324 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3325 /* Remote side is trying to open a channel to talk to a
3326 * forwarded port. Give them back a local channel number. */
3327 struct ssh_channel *c;
3328 struct ssh_rportfwd pf;
3330 char host[256], buf[1024];
3332 c = smalloc(sizeof(struct ssh_channel));
3335 hostsize = GET_32BIT(ssh->pktin.body+4);
3336 for (h = host, p = (char *)(ssh->pktin.body+8);
3337 hostsize != 0; hostsize--) {
3338 if (h+1 < host+sizeof(host))
3343 port = GET_32BIT(p);
3345 strcpy(pf.dhost, host);
3348 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3349 sprintf(buf, "Rejected remote port open request for %s:%d",
3352 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3353 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3355 sprintf(buf, "Received remote port open request for %s:%d",
3358 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3361 sprintf(buf, "Port open failed: %s", e);
3364 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3365 PKT_INT, GET_32BIT(ssh->pktin.body),
3368 c->remoteid = GET_32BIT(ssh->pktin.body);
3369 c->localid = alloc_channel_id(ssh);
3371 c->v.v1.throttling = 0;
3372 c->type = CHAN_SOCKDATA; /* identify channel type */
3373 add234(ssh->channels, c);
3374 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3375 PKT_INT, c->remoteid, PKT_INT,
3376 c->localid, PKT_END);
3377 logevent("Forwarded port opened successfully");
3381 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3382 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3383 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3384 struct ssh_channel *c;
3386 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3387 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3388 c->remoteid = localid;
3389 c->type = CHAN_SOCKDATA;
3390 c->v.v1.throttling = 0;
3391 pfd_confirm(c->u.pfd.s);
3394 if (c && c->closes) {
3396 * We have a pending close on this channel,
3397 * which we decided on before the server acked
3398 * the channel open. So now we know the
3399 * remoteid, we can close it again.
3401 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3402 PKT_INT, c->remoteid, PKT_END);
3405 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3406 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3407 struct ssh_channel *c;
3409 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3410 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3411 logevent("Forwarded connection refused by server");
3412 pfd_close(c->u.pfd.s);
3413 del234(ssh->channels, c);
3417 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3418 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3419 /* Remote side closes a channel. */
3420 unsigned i = GET_32BIT(ssh->pktin.body);
3421 struct ssh_channel *c;
3422 c = find234(ssh->channels, &i, ssh_channelfind);
3423 if (c && ((int)c->remoteid) != -1) {
3426 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3428 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3429 logevent("Forwarded X11 connection terminated");
3430 assert(c->u.x11.s != NULL);
3431 x11_close(c->u.x11.s);
3434 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3435 logevent("Forwarded port closed");
3436 assert(c->u.pfd.s != NULL);
3437 pfd_close(c->u.pfd.s);
3441 c->closes |= (closetype << 2); /* seen this message */
3442 if (!(c->closes & closetype)) {
3443 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3445 c->closes |= closetype; /* sent it too */
3448 if (c->closes == 15) {
3449 del234(ssh->channels, c);
3453 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3454 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3455 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3458 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3459 /* Data sent down one of our channels. */
3460 int i = GET_32BIT(ssh->pktin.body);
3461 int len = GET_32BIT(ssh->pktin.body + 4);
3462 unsigned char *p = ssh->pktin.body + 8;
3463 struct ssh_channel *c;
3464 c = find234(ssh->channels, &i, ssh_channelfind);
3469 bufsize = x11_send(c->u.x11.s, (char *)p, len);
3472 bufsize = pfd_send(c->u.pfd.s, (char *)p, len);
3475 /* Data for an agent message. Buffer it. */
3477 if (c->u.a.lensofar < 4) {
3478 int l = min(4 - c->u.a.lensofar, len);
3479 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3483 c->u.a.lensofar += l;
3485 if (c->u.a.lensofar == 4) {
3487 4 + GET_32BIT(c->u.a.msglen);
3488 c->u.a.message = smalloc(c->u.a.totallen);
3489 memcpy(c->u.a.message, c->u.a.msglen, 4);
3491 if (c->u.a.lensofar >= 4 && len > 0) {
3493 min(c->u.a.totallen - c->u.a.lensofar,
3495 memcpy(c->u.a.message + c->u.a.lensofar, p,
3499 c->u.a.lensofar += l;
3501 if (c->u.a.lensofar == c->u.a.totallen) {
3502 void *reply, *sentreply;
3504 agent_query(c->u.a.message,
3505 c->u.a.totallen, &reply,
3510 /* Fake SSH_AGENT_FAILURE. */
3511 sentreply = "\0\0\0\1\5";
3514 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3515 PKT_INT, c->remoteid,
3517 PKT_DATA, sentreply, replylen,
3521 sfree(c->u.a.message);
3522 c->u.a.lensofar = 0;
3525 bufsize = 0; /* agent channels never back up */
3528 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3529 c->v.v1.throttling = 1;
3530 ssh1_throttle(ssh, +1);
3533 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3534 /* may be from EXEC_SHELL on some servers */
3535 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3536 /* may be from EXEC_SHELL on some servers
3537 * if no pty is available or in other odd cases. Ignore */
3538 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3540 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3541 sprintf(buf, "Server sent command exit status %d",
3544 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3546 * In case `helpful' firewalls or proxies tack
3547 * extra human-readable text on the end of the
3548 * session which we might mistake for another
3549 * encrypted packet, we close the session once
3550 * we've sent EXIT_CONFIRMATION.
3552 ssh->state = SSH_STATE_CLOSED;
3555 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3560 int len = min(inlen, 512);
3561 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3562 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3573 * Utility routine for decoding comma-separated strings in KEXINIT.
3575 static int in_commasep_string(char *needle, char *haystack, int haylen)
3578 if (!needle || !haystack) /* protect against null pointers */
3580 needlen = strlen(needle);
3583 * Is it at the start of the string?
3585 if (haylen >= needlen && /* haystack is long enough */
3586 !memcmp(needle, haystack, needlen) && /* initial match */
3587 (haylen == needlen || haystack[needlen] == ',')
3588 /* either , or EOS follows */
3592 * If not, search for the next comma and resume after that.
3593 * If no comma found, terminate.
3595 while (haylen > 0 && *haystack != ',')
3596 haylen--, haystack++;
3599 haylen--, haystack++; /* skip over comma itself */
3604 * SSH2 key creation method.
3606 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
3607 unsigned char *sessid, char chr,
3608 unsigned char *keyspace)
3611 /* First 20 bytes. */
3613 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3615 SHA_Bytes(&s, H, 20);
3616 SHA_Bytes(&s, &chr, 1);
3617 SHA_Bytes(&s, sessid, 20);
3618 SHA_Final(&s, keyspace);
3619 /* Next 20 bytes. */
3621 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3623 SHA_Bytes(&s, H, 20);
3624 SHA_Bytes(&s, keyspace, 20);
3625 SHA_Final(&s, keyspace + 20);
3629 * Handle the SSH2 transport layer.
3631 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3633 struct do_ssh2_transport_state {
3634 int nbits, pbits, warn;
3635 Bignum p, g, e, f, K;
3636 int kex_init_value, kex_reply_value;
3637 const struct ssh_mac **maclist;
3639 const struct ssh2_cipher *cscipher_tobe;
3640 const struct ssh2_cipher *sccipher_tobe;
3641 const struct ssh_mac *csmac_tobe;
3642 const struct ssh_mac *scmac_tobe;
3643 const struct ssh_compress *cscomp_tobe;
3644 const struct ssh_compress *sccomp_tobe;
3645 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3646 int hostkeylen, siglen;
3647 void *hkey; /* actual host key */
3648 unsigned char exchange_hash[20];
3649 int n_preferred_ciphers;
3650 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3651 const struct ssh_compress *preferred_comp;
3654 crState(do_ssh2_transport_state);
3656 crBegin(ssh->do_ssh2_transport_crstate);
3658 s->cscipher_tobe = s->sccipher_tobe = NULL;
3659 s->csmac_tobe = s->scmac_tobe = NULL;
3660 s->cscomp_tobe = s->sccomp_tobe = NULL;
3668 * Set up the preferred ciphers. (NULL => warn below here)
3670 s->n_preferred_ciphers = 0;
3671 for (i = 0; i < CIPHER_MAX; i++) {
3672 switch (cfg.ssh_cipherlist[i]) {
3673 case CIPHER_BLOWFISH:
3674 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3677 if (cfg.ssh2_des_cbc) {
3678 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3682 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3685 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3688 /* Flag for later. Don't bother if it's the last in
3690 if (i < CIPHER_MAX - 1) {
3691 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3699 * Set up preferred compression.
3701 if (cfg.compression)
3702 s->preferred_comp = &ssh_zlib;
3704 s->preferred_comp = &ssh_comp_none;
3707 * Be prepared to work around the buggy MAC problem.
3709 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3710 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3712 s->maclist = macs, s->nmacs = lenof(macs);
3716 int i, j, cipherstr_started;
3719 * Construct and send our key exchange packet.
3721 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3722 for (i = 0; i < 16; i++)
3723 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3724 /* List key exchange algorithms. */
3725 ssh2_pkt_addstring_start(ssh);
3726 for (i = 0; i < lenof(kex_algs); i++) {
3727 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3728 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3730 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3731 if (i < lenof(kex_algs) - 1)
3732 ssh2_pkt_addstring_str(ssh, ",");
3734 /* List server host key algorithms. */
3735 ssh2_pkt_addstring_start(ssh);
3736 for (i = 0; i < lenof(hostkey_algs); i++) {
3737 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3738 if (i < lenof(hostkey_algs) - 1)
3739 ssh2_pkt_addstring_str(ssh, ",");
3741 /* List client->server encryption algorithms. */
3742 ssh2_pkt_addstring_start(ssh);
3743 cipherstr_started = 0;
3744 for (i = 0; i < s->n_preferred_ciphers; i++) {
3745 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3746 if (!c) continue; /* warning flag */
3747 for (j = 0; j < c->nciphers; j++) {
3748 if (cipherstr_started)
3749 ssh2_pkt_addstring_str(ssh, ",");
3750 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3751 cipherstr_started = 1;
3754 /* List server->client encryption algorithms. */
3755 ssh2_pkt_addstring_start(ssh);
3756 cipherstr_started = 0;
3757 for (i = 0; i < s->n_preferred_ciphers; i++) {
3758 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3759 if (!c) continue; /* warning flag */
3760 for (j = 0; j < c->nciphers; j++) {
3761 if (cipherstr_started)
3762 ssh2_pkt_addstring_str(ssh, ",");
3763 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3764 cipherstr_started = 1;
3767 /* List client->server MAC algorithms. */
3768 ssh2_pkt_addstring_start(ssh);
3769 for (i = 0; i < s->nmacs; i++) {
3770 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3771 if (i < s->nmacs - 1)
3772 ssh2_pkt_addstring_str(ssh, ",");
3774 /* List server->client MAC algorithms. */
3775 ssh2_pkt_addstring_start(ssh);
3776 for (i = 0; i < s->nmacs; i++) {
3777 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3778 if (i < s->nmacs - 1)
3779 ssh2_pkt_addstring_str(ssh, ",");
3781 /* List client->server compression algorithms. */
3782 ssh2_pkt_addstring_start(ssh);
3783 for (i = 0; i < lenof(compressions) + 1; i++) {
3784 const struct ssh_compress *c =
3785 i == 0 ? s->preferred_comp : compressions[i - 1];
3786 ssh2_pkt_addstring_str(ssh, c->name);
3787 if (i < lenof(compressions))
3788 ssh2_pkt_addstring_str(ssh, ",");
3790 /* List server->client compression algorithms. */
3791 ssh2_pkt_addstring_start(ssh);
3792 for (i = 0; i < lenof(compressions) + 1; i++) {
3793 const struct ssh_compress *c =
3794 i == 0 ? s->preferred_comp : compressions[i - 1];
3795 ssh2_pkt_addstring_str(ssh, c->name);
3796 if (i < lenof(compressions))
3797 ssh2_pkt_addstring_str(ssh, ",");
3799 /* List client->server languages. Empty list. */
3800 ssh2_pkt_addstring_start(ssh);
3801 /* List server->client languages. Empty list. */
3802 ssh2_pkt_addstring_start(ssh);
3803 /* First KEX packet does _not_ follow, because we're not that brave. */
3804 ssh2_pkt_addbool(ssh, FALSE);
3806 ssh2_pkt_adduint32(ssh, 0);
3809 ssh->exhash = ssh->exhashbase;
3810 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3816 if (ssh->pktin.length > 5)
3817 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3820 * Now examine the other side's KEXINIT to see what we're up
3827 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3828 bombout((ssh,"expected key exchange packet from server"));
3832 ssh->hostkey = NULL;
3833 s->cscipher_tobe = NULL;
3834 s->sccipher_tobe = NULL;
3835 s->csmac_tobe = NULL;
3836 s->scmac_tobe = NULL;
3837 s->cscomp_tobe = NULL;
3838 s->sccomp_tobe = NULL;
3839 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3840 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3841 for (i = 0; i < lenof(kex_algs); i++) {
3842 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3843 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3845 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3846 ssh->kex = kex_algs[i];
3850 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3851 for (i = 0; i < lenof(hostkey_algs); i++) {
3852 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3853 ssh->hostkey = hostkey_algs[i];
3857 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3859 for (i = 0; i < s->n_preferred_ciphers; i++) {
3860 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3864 for (j = 0; j < c->nciphers; j++) {
3865 if (in_commasep_string(c->list[j]->name, str, len)) {
3866 s->cscipher_tobe = c->list[j];
3871 if (s->cscipher_tobe) {
3873 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3877 if (!s->cscipher_tobe) {
3878 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3879 str ? str : "(null)"));
3883 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3885 for (i = 0; i < s->n_preferred_ciphers; i++) {
3886 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3890 for (j = 0; j < c->nciphers; j++) {
3891 if (in_commasep_string(c->list[j]->name, str, len)) {
3892 s->sccipher_tobe = c->list[j];
3897 if (s->sccipher_tobe) {
3899 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3903 if (!s->sccipher_tobe) {
3904 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3905 str ? str : "(null)"));
3909 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3910 for (i = 0; i < s->nmacs; i++) {
3911 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3912 s->csmac_tobe = s->maclist[i];
3916 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3917 for (i = 0; i < s->nmacs; i++) {
3918 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3919 s->scmac_tobe = s->maclist[i];
3923 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3924 for (i = 0; i < lenof(compressions) + 1; i++) {
3925 const struct ssh_compress *c =
3926 i == 0 ? s->preferred_comp : compressions[i - 1];
3927 if (in_commasep_string(c->name, str, len)) {
3932 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3933 for (i = 0; i < lenof(compressions) + 1; i++) {
3934 const struct ssh_compress *c =
3935 i == 0 ? s->preferred_comp : compressions[i - 1];
3936 if (in_commasep_string(c->name, str, len)) {
3944 * Work out the number of bits of key we will need from the key
3945 * exchange. We start with the maximum key length of either
3951 csbits = s->cscipher_tobe->keylen;
3952 scbits = s->sccipher_tobe->keylen;
3953 s->nbits = (csbits > scbits ? csbits : scbits);
3955 /* The keys only have 160-bit entropy, since they're based on
3956 * a SHA-1 hash. So cap the key size at 160 bits. */
3961 * If we're doing Diffie-Hellman group exchange, start by
3962 * requesting a group.
3964 if (ssh->kex == &ssh_diffiehellman_gex) {
3965 logevent("Doing Diffie-Hellman group exchange");
3966 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3968 * Work out how big a DH group we will need to allow that
3971 s->pbits = 512 << ((s->nbits - 1) / 64);
3972 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3973 ssh2_pkt_adduint32(ssh, s->pbits);
3977 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3978 bombout((ssh,"expected key exchange group packet from server"));
3981 s->p = ssh2_pkt_getmp(ssh);
3982 s->g = ssh2_pkt_getmp(ssh);
3983 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3984 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3985 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3987 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3988 ssh->kex_ctx = dh_setup_group1();
3989 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3990 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3993 logevent("Doing Diffie-Hellman key exchange");
3995 * Now generate and send e for Diffie-Hellman.
3997 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
3998 ssh2_pkt_init(ssh, s->kex_init_value);
3999 ssh2_pkt_addmp(ssh, s->e);
4003 if (ssh->pktin.type != s->kex_reply_value) {
4004 bombout((ssh,"expected key exchange reply packet from server"));
4007 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4008 s->f = ssh2_pkt_getmp(ssh);
4009 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4011 s->K = dh_find_K(ssh->kex_ctx, s->f);
4013 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4014 if (ssh->kex == &ssh_diffiehellman_gex) {
4015 sha_uint32(&ssh->exhash, s->pbits);
4016 sha_mpint(&ssh->exhash, s->p);
4017 sha_mpint(&ssh->exhash, s->g);
4019 sha_mpint(&ssh->exhash, s->e);
4020 sha_mpint(&ssh->exhash, s->f);
4021 sha_mpint(&ssh->exhash, s->K);
4022 SHA_Final(&ssh->exhash, s->exchange_hash);
4024 dh_cleanup(ssh->kex_ctx);
4027 debug(("Exchange hash is:\n"));
4028 dmemdump(s->exchange_hash, 20);
4031 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4033 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4034 (char *)s->exchange_hash, 20)) {
4035 bombout((ssh,"Server's host key did not match the signature supplied"));
4040 * Authenticate remote host: verify host key. (We've already
4041 * checked the signature of the exchange hash.)
4043 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4044 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4045 verify_ssh_host_key(ssh->frontend,
4046 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4047 s->keystr, s->fingerprint);
4048 if (s->first_kex) { /* don't bother logging this in rekeys */
4049 logevent("Host key fingerprint is:");
4050 logevent(s->fingerprint);
4052 sfree(s->fingerprint);
4054 ssh->hostkey->freekey(s->hkey);
4057 * Send SSH2_MSG_NEWKEYS.
4059 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4063 * Expect SSH2_MSG_NEWKEYS from server.
4066 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4067 bombout((ssh,"expected new-keys packet from server"));
4072 * Create and initialise session keys.
4074 if (ssh->cs_cipher_ctx)
4075 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4076 ssh->cscipher = s->cscipher_tobe;
4077 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4079 if (ssh->sc_cipher_ctx)
4080 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4081 ssh->sccipher = s->sccipher_tobe;
4082 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4084 if (ssh->cs_mac_ctx)
4085 ssh->csmac->free_context(ssh->cs_mac_ctx);
4086 ssh->csmac = s->csmac_tobe;
4087 ssh->cs_mac_ctx = ssh->csmac->make_context();
4089 if (ssh->sc_mac_ctx)
4090 ssh->scmac->free_context(ssh->sc_mac_ctx);
4091 ssh->scmac = s->scmac_tobe;
4092 ssh->sc_mac_ctx = ssh->scmac->make_context();
4094 if (ssh->cs_comp_ctx)
4095 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4096 ssh->cscomp = s->cscomp_tobe;
4097 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4099 if (ssh->sc_comp_ctx)
4100 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4101 ssh->sccomp = s->sccomp_tobe;
4102 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4105 * Set IVs after keys. Here we use the exchange hash from the
4106 * _first_ key exchange.
4109 unsigned char keyspace[40];
4111 memcpy(ssh->v2_session_id, s->exchange_hash,
4112 sizeof(s->exchange_hash));
4113 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4114 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4115 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4116 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4117 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4118 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4119 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4120 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4121 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4122 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4123 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4124 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4126 logeventf(ssh, "Initialised %.200s client->server encryption",
4127 ssh->cscipher->text_name);
4128 logeventf(ssh, "Initialised %.200s server->client encryption",
4129 ssh->sccipher->text_name);
4130 if (ssh->cscomp->text_name)
4131 logeventf(ssh, "Initialised %s compression",
4132 ssh->cscomp->text_name);
4133 if (ssh->sccomp->text_name)
4134 logeventf(ssh, "Initialised %s decompression",
4135 ssh->sccomp->text_name);
4138 * If this is the first key exchange phase, we must pass the
4139 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4140 * wants to see it but because it will need time to initialise
4141 * itself before it sees an actual packet. In subsequent key
4142 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4143 * it would only confuse the layer above.
4145 if (!s->first_kex) {
4151 * Now we're encrypting. Begin returning 1 to the protocol main
4152 * function so that other things can run on top of the
4153 * transport. If we ever see a KEXINIT, we must go back to the
4156 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4159 logevent("Server initiated key re-exchange");
4160 goto begin_key_exchange;
4166 * Add data to an SSH2 channel output buffer.
4168 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4171 bufchain_add(&c->v.v2.outbuffer, buf, len);
4175 * Attempt to send data on an SSH2 channel.
4177 static int ssh2_try_send(struct ssh_channel *c)
4181 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4184 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4185 if ((unsigned)len > c->v.v2.remwindow)
4186 len = c->v.v2.remwindow;
4187 if ((unsigned)len > c->v.v2.remmaxpkt)
4188 len = c->v.v2.remmaxpkt;
4189 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4190 ssh2_pkt_adduint32(ssh, c->remoteid);
4191 ssh2_pkt_addstring_start(ssh);
4192 ssh2_pkt_addstring_data(ssh, data, len);
4194 bufchain_consume(&c->v.v2.outbuffer, len);
4195 c->v.v2.remwindow -= len;
4199 * After having sent as much data as we can, return the amount
4202 return bufchain_size(&c->v.v2.outbuffer);
4206 * Potentially enlarge the window on an SSH2 channel.
4208 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4213 * Never send WINDOW_ADJUST for a channel that the remote side
4214 * already thinks it's closed; there's no point, since it won't
4215 * be sending any more data anyway.
4220 if (newwin > c->v.v2.locwindow) {
4221 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4222 ssh2_pkt_adduint32(ssh, c->remoteid);
4223 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4225 c->v.v2.locwindow = newwin;
4230 * Handle the SSH2 userauth and connection layers.
4232 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4234 struct do_ssh2_authconn_state {
4236 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4238 AUTH_KEYBOARD_INTERACTIVE
4242 AUTH_TYPE_PUBLICKEY,
4243 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4244 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4246 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4247 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4249 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4250 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4251 int kbd_inter_running;
4253 int num_prompts, curr_prompt, echo;
4258 void *publickey_blob;
4259 int publickey_bloblen;
4260 unsigned char request[5], *response, *p;
4264 char *pkblob, *alg, *commentp;
4265 int pklen, alglen, commentlen;
4266 int siglen, retlen, len;
4267 char *q, *agentreq, *ret;
4270 crState(do_ssh2_authconn_state);
4272 crBegin(ssh->do_ssh2_authconn_crstate);
4275 * Request userauth protocol, and await a response to it.
4277 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4278 ssh2_pkt_addstring(ssh, "ssh-userauth");
4280 crWaitUntilV(ispkt);
4281 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4282 bombout((ssh,"Server refused user authentication protocol"));
4287 * We repeat this whole loop, including the username prompt,
4288 * until we manage a successful authentication. If the user
4289 * types the wrong _password_, they can be sent back to the
4290 * beginning to try another username, if this is configured on.
4291 * (If they specify a username in the config, they are never
4292 * asked, even if they do give a wrong password.)
4294 * I think this best serves the needs of
4296 * - the people who have no configuration, no keys, and just
4297 * want to try repeated (username,password) pairs until they
4298 * type both correctly
4300 * - people who have keys and configuration but occasionally
4301 * need to fall back to passwords
4303 * - people with a key held in Pageant, who might not have
4304 * logged in to a particular machine before; so they want to
4305 * type a username, and then _either_ their key will be
4306 * accepted, _or_ they will type a password. If they mistype
4307 * the username they will want to be able to get back and
4310 s->username[0] = '\0';
4311 s->got_username = FALSE;
4316 if (s->got_username && !cfg.change_username) {
4318 * We got a username last time round this loop, and
4319 * with change_username turned off we don't try to get
4322 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4323 if (ssh_get_line && !ssh_getline_pw_only) {
4324 if (!ssh_get_line("login as: ",
4325 s->username, sizeof(s->username), FALSE)) {
4327 * get_line failed to get a username.
4330 logevent("No username provided. Abandoning session.");
4331 ssh->state = SSH_STATE_CLOSED;
4335 int ret; /* need not be saved across crReturn */
4336 c_write_str(ssh, "login as: ");
4338 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4340 crWaitUntilV(!ispkt);
4341 ret = process_userpass_input(ssh, in, inlen);
4345 c_write_str(ssh, "\r\n");
4347 s->username[strcspn(s->username, "\n\r")] = '\0';
4350 strncpy(s->username, cfg.username, sizeof(s->username));
4351 s->username[sizeof(s->username)-1] = '\0';
4352 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4353 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4354 c_write_str(ssh, stuff);
4358 s->got_username = TRUE;
4361 * Send an authentication request using method "none": (a)
4362 * just in case it succeeds, and (b) so that we know what
4363 * authentication methods we can usefully try next.
4365 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4367 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4368 ssh2_pkt_addstring(ssh, s->username);
4369 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4370 ssh2_pkt_addstring(ssh, "none"); /* method */
4372 s->type = AUTH_TYPE_NONE;
4374 s->we_are_in = FALSE;
4376 s->tried_pubkey_config = FALSE;
4377 s->tried_agent = FALSE;
4378 s->tried_keyb_inter = FALSE;
4379 s->kbd_inter_running = FALSE;
4380 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4383 logeventf(ssh, "Reading private key file \"%.150s\"", cfg.keyfile);
4384 keytype = key_type(cfg.keyfile);
4385 if (keytype == SSH_KEYTYPE_SSH2) {
4387 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4388 &s->publickey_bloblen);
4391 logeventf(ssh, "Unable to use this key file (%s)",
4392 key_type_to_str(keytype));
4393 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4394 " (%s)\r\n", cfg.keyfile,
4395 key_type_to_str(keytype));
4396 c_write_str(ssh, msgbuf);
4398 s->publickey_blob = NULL;
4401 s->publickey_blob = NULL;
4405 * Wait for the result of the last authentication request.
4408 crWaitUntilV(ispkt);
4409 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4413 * Don't show the banner if we're operating in
4414 * non-verbose non-interactive mode. (It's probably
4415 * a script, which means nobody will read the
4416 * banner _anyway_, and moreover the printing of
4417 * the banner will screw up processing on the
4418 * output of (say) plink.)
4420 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4421 ssh2_pkt_getstring(ssh, &banner, &size);
4423 c_write_untrusted(ssh, banner, size);
4425 crWaitUntilV(ispkt);
4427 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4428 logevent("Access granted");
4429 s->we_are_in = TRUE;
4433 if (s->kbd_inter_running &&
4434 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4436 * This is either a further set-of-prompts packet
4437 * in keyboard-interactive authentication, or it's
4438 * the same one and we came back here with `gotit'
4439 * set. In the former case, we must reset the
4440 * curr_prompt variable.
4444 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4445 bombout((ssh,"Strange packet received during authentication: type %d",
4453 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4454 * we can look at the string in it and know what we can
4455 * helpfully try next.
4457 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4460 ssh2_pkt_getstring(ssh, &methods, &methlen);
4461 s->kbd_inter_running = FALSE;
4462 if (!ssh2_pkt_getbool(ssh)) {
4464 * We have received an unequivocal Access
4465 * Denied. This can translate to a variety of
4468 * - if we'd just tried "none" authentication,
4469 * it's not worth printing anything at all
4471 * - if we'd just tried a public key _offer_,
4472 * the message should be "Server refused our
4473 * key" (or no message at all if the key
4474 * came from Pageant)
4476 * - if we'd just tried anything else, the
4477 * message really should be "Access denied".
4479 * Additionally, if we'd just tried password
4480 * authentication, we should break out of this
4481 * whole loop so as to go back to the username
4484 if (s->type == AUTH_TYPE_NONE) {
4486 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4487 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4488 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4489 c_write_str(ssh, "Server refused our key\r\n");
4490 logevent("Server refused public key");
4491 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4492 /* server declined keyboard-interactive; ignore */
4494 c_write_str(ssh, "Access denied\r\n");
4495 logevent("Access denied");
4496 if (s->type == AUTH_TYPE_PASSWORD) {
4497 s->we_are_in = FALSE;
4502 c_write_str(ssh, "Further authentication required\r\n");
4503 logevent("Further authentication required");
4507 in_commasep_string("publickey", methods, methlen);
4509 in_commasep_string("password", methods, methlen);
4510 s->can_keyb_inter = cfg.try_ki_auth &&
4511 in_commasep_string("keyboard-interactive", methods, methlen);
4515 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4518 * Most password/passphrase prompts will be
4519 * non-echoing, so we set this to 0 by default.
4520 * Exception is that some keyboard-interactive prompts
4521 * can be echoing, in which case we'll set this to 1.
4525 if (!s->method && s->can_pubkey &&
4526 agent_exists() && !s->tried_agent) {
4528 * Attempt public-key authentication using Pageant.
4533 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4534 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4536 s->tried_agent = TRUE;
4538 logevent("Pageant is running. Requesting keys.");
4540 /* Request the keys held by the agent. */
4541 PUT_32BIT(s->request, 1);
4542 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4543 agent_query(s->request, 5, &r, &s->responselen);
4544 s->response = (unsigned char *) r;
4545 if (s->response && s->responselen >= 5 &&
4546 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4547 s->p = s->response + 5;
4548 s->nkeys = GET_32BIT(s->p);
4552 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4555 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4560 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4563 s->pklen = GET_32BIT(s->p);
4565 if (s->publickey_blob &&
4566 s->pklen == s->publickey_bloblen &&
4567 !memcmp(s->p, s->publickey_blob,
4568 s->publickey_bloblen)) {
4569 logevent("This key matches configured key file");
4570 s->tried_pubkey_config = 1;
4572 s->pkblob = (char *)s->p;
4574 s->alglen = GET_32BIT(s->pkblob);
4575 s->alg = s->pkblob + 4;
4576 s->commentlen = GET_32BIT(s->p);
4578 s->commentp = (char *)s->p;
4579 s->p += s->commentlen;
4580 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4581 ssh2_pkt_addstring(ssh, s->username);
4582 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4583 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4584 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4585 ssh2_pkt_addstring_start(ssh);
4586 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4587 ssh2_pkt_addstring_start(ssh);
4588 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4591 crWaitUntilV(ispkt);
4592 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4593 logevent("Key refused");
4597 if (flags & FLAG_VERBOSE) {
4598 c_write_str(ssh, "Authenticating with "
4600 c_write(ssh, s->commentp, s->commentlen);
4601 c_write_str(ssh, "\" from agent\r\n");
4605 * Server is willing to accept the key.
4606 * Construct a SIGN_REQUEST.
4608 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4609 ssh2_pkt_addstring(ssh, s->username);
4610 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4611 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4612 ssh2_pkt_addbool(ssh, TRUE);
4613 ssh2_pkt_addstring_start(ssh);
4614 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4615 ssh2_pkt_addstring_start(ssh);
4616 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4618 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4619 s->len = 1; /* message type */
4620 s->len += 4 + s->pklen; /* key blob */
4621 s->len += 4 + s->siglen; /* data to sign */
4622 s->len += 4; /* flags */
4623 s->agentreq = smalloc(4 + s->len);
4624 PUT_32BIT(s->agentreq, s->len);
4625 s->q = s->agentreq + 4;
4626 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4627 PUT_32BIT(s->q, s->pklen);
4629 memcpy(s->q, s->pkblob, s->pklen);
4631 PUT_32BIT(s->q, s->siglen);
4633 /* Now the data to be signed... */
4634 PUT_32BIT(s->q, 20);
4636 memcpy(s->q, ssh->v2_session_id, 20);
4638 memcpy(s->q, ssh->pktout.data + 5,
4639 ssh->pktout.length - 5);
4640 s->q += ssh->pktout.length - 5;
4641 /* And finally the (zero) flags word. */
4643 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4647 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4648 logevent("Sending Pageant's response");
4649 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4651 GET_32BIT(s->ret + 5));
4657 ("Pageant failed to answer challenge");
4667 if (!s->method && s->can_pubkey && s->publickey_blob
4668 && !s->tried_pubkey_config) {
4669 unsigned char *pub_blob;
4670 char *algorithm, *comment;
4673 s->tried_pubkey_config = TRUE;
4675 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4676 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4679 * Try the public key supplied in the configuration.
4681 * First, offer the public blob to see if the server is
4682 * willing to accept it.
4685 (unsigned char *)ssh2_userkey_loadpub(cfg.keyfile,
4689 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4690 ssh2_pkt_addstring(ssh, s->username);
4691 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4692 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4693 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4694 ssh2_pkt_addstring(ssh, algorithm);
4695 ssh2_pkt_addstring_start(ssh);
4696 ssh2_pkt_addstring_data(ssh, (char *)pub_blob,
4699 logevent("Offered public key"); /* FIXME */
4701 crWaitUntilV(ispkt);
4702 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4704 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4705 continue; /* key refused; give up on it */
4708 logevent("Offer of public key accepted");
4710 * Actually attempt a serious authentication using
4713 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4714 sprintf(s->pwprompt,
4715 "Passphrase for key \"%.100s\": ",
4721 c_write_str(ssh, "Authenticating with public key \"");
4722 c_write_str(ssh, comment);
4723 c_write_str(ssh, "\"\r\n");
4724 s->method = AUTH_PUBLICKEY_FILE;
4728 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4729 s->method = AUTH_KEYBOARD_INTERACTIVE;
4730 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4731 s->tried_keyb_inter = TRUE;
4733 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4734 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4736 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4737 ssh2_pkt_addstring(ssh, s->username);
4738 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4739 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4740 ssh2_pkt_addstring(ssh, ""); /* lang */
4741 ssh2_pkt_addstring(ssh, "");
4744 crWaitUntilV(ispkt);
4745 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4746 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4748 logevent("Keyboard-interactive authentication refused");
4749 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4753 s->kbd_inter_running = TRUE;
4757 if (s->kbd_inter_running) {
4758 s->method = AUTH_KEYBOARD_INTERACTIVE;
4759 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4760 s->tried_keyb_inter = TRUE;
4762 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4763 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4765 if (s->curr_prompt == 0) {
4767 * We've got a fresh USERAUTH_INFO_REQUEST.
4768 * Display header data, and start going through
4771 char *name, *inst, *lang;
4772 int name_len, inst_len, lang_len;
4774 ssh2_pkt_getstring(ssh, &name, &name_len);
4775 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4776 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4778 c_write_untrusted(ssh, name, name_len);
4779 c_write_str(ssh, "\r\n");
4782 c_write_untrusted(ssh, inst, inst_len);
4783 c_write_str(ssh, "\r\n");
4785 s->num_prompts = ssh2_pkt_getuint32(ssh);
4789 * If there are prompts remaining in the packet,
4790 * display one and get a response.
4792 if (s->curr_prompt < s->num_prompts) {
4796 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4797 if (prompt_len > 0) {
4798 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4799 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4800 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4803 "<server failed to send prompt>: ");
4805 s->echo = ssh2_pkt_getbool(ssh);
4811 if (!s->method && s->can_passwd) {
4812 s->method = AUTH_PASSWORD;
4813 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4814 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4815 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4822 if (!ssh_get_line(s->pwprompt, s->password,
4823 sizeof(s->password), TRUE)) {
4825 * get_line failed to get a password (for
4826 * example because one was supplied on the
4827 * command line which has already failed to
4830 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4831 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4832 ssh2_pkt_addstring(ssh, "No more passwords available"
4834 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4836 logevent("Unable to authenticate");
4837 connection_fatal(ssh->frontend,
4838 "Unable to authenticate");
4839 ssh->state = SSH_STATE_CLOSED;
4843 int ret; /* need not be saved across crReturn */
4844 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4847 setup_userpass_input(ssh, s->password,
4848 sizeof(s->password), s->echo);
4850 crWaitUntilV(!ispkt);
4851 ret = process_userpass_input(ssh, in, inlen);
4855 c_write_str(ssh, "\r\n");
4859 if (s->method == AUTH_PUBLICKEY_FILE) {
4861 * We have our passphrase. Now try the actual authentication.
4863 struct ssh2_userkey *key;
4865 key = ssh2_load_userkey(cfg.keyfile, s->password);
4866 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4867 if (key == SSH2_WRONG_PASSPHRASE) {
4868 c_write_str(ssh, "Wrong passphrase\r\n");
4869 s->tried_pubkey_config = FALSE;
4871 c_write_str(ssh, "Unable to load private key\r\n");
4872 s->tried_pubkey_config = TRUE;
4874 /* Send a spurious AUTH_NONE to return to the top. */
4875 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4876 ssh2_pkt_addstring(ssh, s->username);
4877 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4878 ssh2_pkt_addstring(ssh, "none"); /* method */
4880 s->type = AUTH_TYPE_NONE;
4882 unsigned char *pkblob, *sigblob, *sigdata;
4883 int pkblob_len, sigblob_len, sigdata_len;
4886 * We have loaded the private key and the server
4887 * has announced that it's willing to accept it.
4888 * Hallelujah. Generate a signature and send it.
4890 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4891 ssh2_pkt_addstring(ssh, s->username);
4892 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4893 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4894 ssh2_pkt_addbool(ssh, TRUE);
4895 ssh2_pkt_addstring(ssh, key->alg->name);
4896 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4897 ssh2_pkt_addstring_start(ssh);
4898 ssh2_pkt_addstring_data(ssh, (char *)pkblob, pkblob_len);
4901 * The data to be signed is:
4905 * followed by everything so far placed in the
4908 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4909 sigdata = smalloc(sigdata_len);
4910 PUT_32BIT(sigdata, 20);
4911 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4912 memcpy(sigdata + 24, ssh->pktout.data + 5,
4913 ssh->pktout.length - 5);
4914 sigblob = key->alg->sign(key->data, (char *)sigdata,
4915 sigdata_len, &sigblob_len);
4916 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4917 sigblob, sigblob_len);
4923 s->type = AUTH_TYPE_PUBLICKEY;
4925 } else if (s->method == AUTH_PASSWORD) {
4927 * We send the password packet lumped tightly together with
4928 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4929 * string long enough to make the total length of the two
4930 * packets constant. This should ensure that a passive
4931 * listener doing traffic analyis can't work out the length
4934 * For this to work, we need an assumption about the
4935 * maximum length of the password packet. I think 256 is
4936 * pretty conservative. Anyone using a password longer than
4937 * that probably doesn't have much to worry about from
4938 * people who find out how long their password is!
4940 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4941 ssh2_pkt_addstring(ssh, s->username);
4942 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4943 ssh2_pkt_addstring(ssh, "password");
4944 ssh2_pkt_addbool(ssh, FALSE);
4945 ssh2_pkt_addstring(ssh, s->password);
4946 memset(s->password, 0, sizeof(s->password));
4947 ssh2_pkt_defer(ssh);
4949 * We'll include a string that's an exact multiple of the
4950 * cipher block size. If the cipher is NULL for some
4951 * reason, we don't do this trick at all because we gain
4954 if (ssh->cscipher) {
4957 stringlen = (256 - ssh->deferred_len);
4958 stringlen += ssh->cscipher->blksize - 1;
4959 stringlen -= (stringlen % ssh->cscipher->blksize);
4962 * Temporarily disable actual compression,
4963 * so we can guarantee to get this string
4964 * exactly the length we want it. The
4965 * compression-disabling routine should
4966 * return an integer indicating how many
4967 * bytes we should adjust our string length
4971 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4973 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4974 ssh2_pkt_addstring_start(ssh);
4975 for (i = 0; i < stringlen; i++) {
4976 char c = (char) random_byte();
4977 ssh2_pkt_addstring_data(ssh, &c, 1);
4979 ssh2_pkt_defer(ssh);
4981 ssh_pkt_defersend(ssh);
4982 logevent("Sent password");
4983 s->type = AUTH_TYPE_PASSWORD;
4984 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4985 if (s->curr_prompt == 0) {
4986 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4987 ssh2_pkt_adduint32(ssh, s->num_prompts);
4989 if (s->need_pw) { /* only add pw if we just got one! */
4990 ssh2_pkt_addstring(ssh, s->password);
4991 memset(s->password, 0, sizeof(s->password));
4994 if (s->curr_prompt >= s->num_prompts) {
4998 * If there are prompts remaining, we set
4999 * `gotit' so that we won't attempt to get
5000 * another packet. Then we go back round the
5001 * loop and will end up retrieving another
5002 * prompt out of the existing packet. Funky or
5007 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5009 c_write_str(ssh, "No supported authentication methods"
5010 " left to try!\r\n");
5011 logevent("No supported authentications offered."
5013 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5014 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5015 ssh2_pkt_addstring(ssh, "No supported authentication"
5016 " methods available");
5017 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5019 ssh->state = SSH_STATE_CLOSED;
5023 } while (!s->we_are_in);
5026 * Now we're authenticated for the connection protocol. The
5027 * connection protocol will automatically have started at this
5028 * point; there's no need to send SERVICE_REQUEST.
5032 * So now create a channel with a session in it.
5034 ssh->channels = newtree234(ssh_channelcmp);
5035 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5036 ssh->mainchan->ssh = ssh;
5037 ssh->mainchan->localid = alloc_channel_id(ssh);
5038 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5039 ssh2_pkt_addstring(ssh, "session");
5040 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5041 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5042 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5043 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5045 crWaitUntilV(ispkt);
5046 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5047 bombout((ssh,"Server refused to open a session"));
5049 /* FIXME: error data comes back in FAILURE packet */
5051 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5052 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5055 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5056 ssh->mainchan->type = CHAN_MAINSESSION;
5057 ssh->mainchan->closes = 0;
5058 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5059 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5060 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5061 add234(ssh->channels, ssh->mainchan);
5062 logevent("Opened channel for session");
5065 * Potentially enable X11 forwarding.
5067 if (cfg.x11_forward) {
5068 char proto[20], data[64];
5069 logevent("Requesting X11 forwarding");
5070 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5071 data, sizeof(data));
5072 x11_get_real_auth(ssh->x11auth, cfg.x11_display);
5073 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5074 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5075 ssh2_pkt_addstring(ssh, "x11-req");
5076 ssh2_pkt_addbool(ssh, 1); /* want reply */
5077 ssh2_pkt_addbool(ssh, 0); /* many connections */
5078 ssh2_pkt_addstring(ssh, proto);
5079 ssh2_pkt_addstring(ssh, data);
5080 ssh2_pkt_adduint32(ssh, x11_get_screen_number(cfg.x11_display));
5084 crWaitUntilV(ispkt);
5085 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5086 unsigned i = ssh2_pkt_getuint32(ssh);
5087 struct ssh_channel *c;
5088 c = find234(ssh->channels, &i, ssh_channelfind);
5090 continue; /* nonexistent channel */
5091 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5093 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5095 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5096 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5097 bombout((ssh,"Unexpected response to X11 forwarding request:"
5098 " packet type %d", ssh->pktin.type));
5101 logevent("X11 forwarding refused");
5103 logevent("X11 forwarding enabled");
5104 ssh->X11_fwd_enabled = TRUE;
5109 * Enable port forwardings.
5114 int sport,dport,sserv,dserv;
5115 char sports[256], dports[256], saddr[256], host[256];
5117 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5118 /* Add port forwardings. */
5119 ssh->portfwd_strptr = cfg.portfwd;
5120 while (*ssh->portfwd_strptr) {
5121 type = *ssh->portfwd_strptr++;
5124 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5125 if (*ssh->portfwd_strptr == ':') {
5127 * We've seen a colon in the middle of the
5128 * source port number. This means that
5129 * everything we've seen until now is the
5130 * source _address_, so we'll move it into
5131 * saddr and start sports from the beginning
5134 ssh->portfwd_strptr++;
5136 strcpy(saddr, sports);
5139 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5142 if (*ssh->portfwd_strptr == '\t')
5143 ssh->portfwd_strptr++;
5145 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5146 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5149 if (*ssh->portfwd_strptr == ':')
5150 ssh->portfwd_strptr++;
5152 while (*ssh->portfwd_strptr) {
5153 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5156 ssh->portfwd_strptr++;
5157 dport = atoi(dports);
5161 dport = net_service_lookup(dports);
5163 logeventf(ssh, "Service lookup failed for destination"
5164 " port \"%s\"", dports);
5167 sport = atoi(sports);
5171 sport = net_service_lookup(sports);
5173 logeventf(ssh, "Service lookup failed for source"
5174 " port \"%s\"", sports);
5177 if (sport && dport) {
5179 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5181 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5182 " forwarding to %s:%.*s%.*s%d%.*s",
5183 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5184 (int)(*saddr?1:0), ":",
5185 (int)(sserv ? strlen(sports) : 0), sports,
5186 sserv, "(", sport, sserv, ")",
5188 (int)(dserv ? strlen(dports) : 0), dports,
5189 dserv, "(", dport, dserv, ")");
5191 struct ssh_rportfwd *pf;
5192 pf = smalloc(sizeof(*pf));
5193 strcpy(pf->dhost, host);
5196 if (add234(ssh->rportfwds, pf) != pf) {
5197 logeventf(ssh, "Duplicate remote port forwarding"
5198 " to %s:%d", host, dport);
5201 logeventf(ssh, "Requesting remote port "
5202 "%.*s%.*s%.*s%.*s%d%.*s"
5203 " forward to %s:%.*s%.*s%d%.*s",
5204 (int)(*saddr?strlen(saddr):0),
5206 (int)(*saddr?1:0), ":",
5207 (int)(sserv ? strlen(sports) : 0), sports,
5208 sserv, "(", sport, sserv, ")",
5210 (int)(dserv ? strlen(dports) : 0), dports,
5211 dserv, "(", dport, dserv, ")");
5212 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5213 ssh2_pkt_addstring(ssh, "tcpip-forward");
5214 ssh2_pkt_addbool(ssh, 1);/* want reply */
5216 ssh2_pkt_addstring(ssh, saddr);
5217 if (cfg.rport_acceptall)
5218 ssh2_pkt_addstring(ssh, "0.0.0.0");
5220 ssh2_pkt_addstring(ssh, "127.0.0.1");
5221 ssh2_pkt_adduint32(ssh, sport);
5225 crWaitUntilV(ispkt);
5226 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5227 unsigned i = ssh2_pkt_getuint32(ssh);
5228 struct ssh_channel *c;
5229 c = find234(ssh->channels, &i, ssh_channelfind);
5231 continue;/* nonexistent channel */
5232 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5234 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5236 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5237 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5238 bombout((ssh,"Unexpected response to port "
5239 "forwarding request: packet type %d",
5243 logevent("Server refused this port forwarding");
5245 logevent("Remote port forwarding enabled");
5254 * Potentially enable agent forwarding.
5256 if (cfg.agentfwd && agent_exists()) {
5257 logevent("Requesting OpenSSH-style agent forwarding");
5258 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5259 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5260 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5261 ssh2_pkt_addbool(ssh, 1); /* want reply */
5265 crWaitUntilV(ispkt);
5266 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5267 unsigned i = ssh2_pkt_getuint32(ssh);
5268 struct ssh_channel *c;
5269 c = find234(ssh->channels, &i, ssh_channelfind);
5271 continue; /* nonexistent channel */
5272 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5274 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5276 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5277 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5278 bombout((ssh,"Unexpected response to agent forwarding request:"
5279 " packet type %d", ssh->pktin.type));
5282 logevent("Agent forwarding refused");
5284 logevent("Agent forwarding enabled");
5285 ssh->agentfwd_enabled = TRUE;
5290 * Now allocate a pty for the session.
5293 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5294 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5295 ssh2_pkt_addstring(ssh, "pty-req");
5296 ssh2_pkt_addbool(ssh, 1); /* want reply */
5297 ssh2_pkt_addstring(ssh, cfg.termtype);
5298 ssh2_pkt_adduint32(ssh, ssh->term_width);
5299 ssh2_pkt_adduint32(ssh, ssh->term_height);
5300 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5301 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5302 ssh2_pkt_addstring_start(ssh);
5303 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5305 ssh->state = SSH_STATE_INTERMED;
5308 crWaitUntilV(ispkt);
5309 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5310 unsigned i = ssh2_pkt_getuint32(ssh);
5311 struct ssh_channel *c;
5312 c = find234(ssh->channels, &i, ssh_channelfind);
5314 continue; /* nonexistent channel */
5315 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5317 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5319 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5320 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5321 bombout((ssh,"Unexpected response to pty request:"
5322 " packet type %d", ssh->pktin.type));
5325 c_write_str(ssh, "Server refused to allocate pty\r\n");
5326 ssh->editing = ssh->echoing = 1;
5328 logevent("Allocated pty");
5331 ssh->editing = ssh->echoing = 1;
5335 * Start a shell or a remote command. We may have to attempt
5336 * this twice if the config data has provided a second choice
5343 if (ssh->fallback_cmd) {
5344 subsys = cfg.ssh_subsys2;
5345 cmd = cfg.remote_cmd_ptr2;
5347 subsys = cfg.ssh_subsys;
5348 cmd = cfg.remote_cmd_ptr;
5351 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5352 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5354 ssh2_pkt_addstring(ssh, "subsystem");
5355 ssh2_pkt_addbool(ssh, 1); /* want reply */
5356 ssh2_pkt_addstring(ssh, cmd);
5358 ssh2_pkt_addstring(ssh, "exec");
5359 ssh2_pkt_addbool(ssh, 1); /* want reply */
5360 ssh2_pkt_addstring(ssh, cmd);
5362 ssh2_pkt_addstring(ssh, "shell");
5363 ssh2_pkt_addbool(ssh, 1); /* want reply */
5367 crWaitUntilV(ispkt);
5368 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5369 unsigned i = ssh2_pkt_getuint32(ssh);
5370 struct ssh_channel *c;
5371 c = find234(ssh->channels, &i, ssh_channelfind);
5373 continue; /* nonexistent channel */
5374 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5376 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5377 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5378 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5379 bombout((ssh,"Unexpected response to shell/command request:"
5380 " packet type %d", ssh->pktin.type));
5384 * We failed to start the command. If this is the
5385 * fallback command, we really are finished; if it's
5386 * not, and if the fallback command exists, try falling
5387 * back to it before complaining.
5389 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5390 logevent("Primary command failed; attempting fallback");
5391 ssh->fallback_cmd = TRUE;
5394 bombout((ssh,"Server refused to start a shell/command"));
5397 logevent("Started a shell/command");
5402 ssh->state = SSH_STATE_SESSION;
5403 if (ssh->size_needed)
5404 ssh_size(ssh, ssh->term_width, ssh->term_height);
5405 if (ssh->eof_needed)
5406 ssh_special(ssh, TS_EOF);
5412 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5416 s->try_send = FALSE;
5418 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5419 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5422 unsigned i = ssh2_pkt_getuint32(ssh);
5423 struct ssh_channel *c;
5424 c = find234(ssh->channels, &i, ssh_channelfind);
5426 continue; /* nonexistent channel */
5427 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5428 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5429 continue; /* extended but not stderr */
5430 ssh2_pkt_getstring(ssh, &data, &length);
5433 c->v.v2.locwindow -= length;
5435 case CHAN_MAINSESSION:
5437 from_backend(ssh->frontend, ssh->pktin.type ==
5438 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5442 bufsize = x11_send(c->u.x11.s, data, length);
5445 bufsize = pfd_send(c->u.pfd.s, data, length);
5448 while (length > 0) {
5449 if (c->u.a.lensofar < 4) {
5450 int l = min(4 - c->u.a.lensofar, length);
5451 memcpy(c->u.a.msglen + c->u.a.lensofar,
5455 c->u.a.lensofar += l;
5457 if (c->u.a.lensofar == 4) {
5459 4 + GET_32BIT(c->u.a.msglen);
5460 c->u.a.message = smalloc(c->u.a.totallen);
5461 memcpy(c->u.a.message, c->u.a.msglen, 4);
5463 if (c->u.a.lensofar >= 4 && length > 0) {
5465 min(c->u.a.totallen - c->u.a.lensofar,
5467 memcpy(c->u.a.message + c->u.a.lensofar,
5471 c->u.a.lensofar += l;
5473 if (c->u.a.lensofar == c->u.a.totallen) {
5474 void *reply, *sentreply;
5476 agent_query(c->u.a.message,
5477 c->u.a.totallen, &reply,
5482 /* Fake SSH_AGENT_FAILURE. */
5483 sentreply = "\0\0\0\1\5";
5486 ssh2_add_channel_data(c, sentreply, replylen);
5490 sfree(c->u.a.message);
5491 c->u.a.lensofar = 0;
5498 * If we are not buffering too much data,
5499 * enlarge the window again at the remote side.
5501 if (bufsize < OUR_V2_WINSIZE)
5502 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5504 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5505 unsigned i = ssh2_pkt_getuint32(ssh);
5506 struct ssh_channel *c;
5508 c = find234(ssh->channels, &i, ssh_channelfind);
5510 continue; /* nonexistent channel */
5512 if (c->type == CHAN_X11) {
5514 * Remote EOF on an X11 channel means we should
5515 * wrap up and close the channel ourselves.
5517 x11_close(c->u.x11.s);
5519 } else if (c->type == CHAN_AGENT) {
5521 } else if (c->type == CHAN_SOCKDATA) {
5522 pfd_close(c->u.pfd.s);
5525 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5526 unsigned i = ssh2_pkt_getuint32(ssh);
5527 struct ssh_channel *c;
5529 c = find234(ssh->channels, &i, ssh_channelfind);
5530 if (!c || ((int)c->remoteid) == -1) {
5531 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5532 c ? "half-open" : "nonexistent", i));
5534 /* Do pre-close processing on the channel. */
5536 case CHAN_MAINSESSION:
5537 break; /* nothing to see here, move along */
5539 if (c->u.x11.s != NULL)
5540 x11_close(c->u.x11.s);
5547 if (c->u.pfd.s != NULL)
5548 pfd_close(c->u.pfd.s);
5552 if (c->closes == 0) {
5553 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5554 ssh2_pkt_adduint32(ssh, c->remoteid);
5557 del234(ssh->channels, c);
5558 bufchain_clear(&c->v.v2.outbuffer);
5562 * See if that was the last channel left open.
5564 if (count234(ssh->channels) == 0) {
5567 * We used to send SSH_MSG_DISCONNECT here,
5568 * because I'd believed that _every_ conforming
5569 * SSH2 connection had to end with a disconnect
5570 * being sent by at least one side; apparently
5571 * I was wrong and it's perfectly OK to
5572 * unceremoniously slam the connection shut
5573 * when you're done, and indeed OpenSSH feels
5574 * this is more polite than sending a
5575 * DISCONNECT. So now we don't.
5577 logevent("All channels closed. Disconnecting");
5578 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5579 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5580 ssh2_pkt_addstring(ssh, "All open channels closed");
5581 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5584 ssh->state = SSH_STATE_CLOSED;
5587 continue; /* remote sends close; ignore (FIXME) */
5588 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5589 unsigned i = ssh2_pkt_getuint32(ssh);
5590 struct ssh_channel *c;
5591 c = find234(ssh->channels, &i, ssh_channelfind);
5592 if (!c || c->closes)
5593 continue; /* nonexistent or closing channel */
5594 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5596 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5597 unsigned i = ssh2_pkt_getuint32(ssh);
5598 struct ssh_channel *c;
5599 c = find234(ssh->channels, &i, ssh_channelfind);
5601 continue; /* nonexistent channel */
5602 if (c->type != CHAN_SOCKDATA_DORMANT)
5603 continue; /* dunno why they're confirming this */
5604 c->remoteid = ssh2_pkt_getuint32(ssh);
5605 c->type = CHAN_SOCKDATA;
5606 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5607 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5609 pfd_confirm(c->u.pfd.s);
5612 * We have a pending close on this channel,
5613 * which we decided on before the server acked
5614 * the channel open. So now we know the
5615 * remoteid, we can close it again.
5617 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5618 ssh2_pkt_adduint32(ssh, c->remoteid);
5621 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5622 unsigned i = ssh2_pkt_getuint32(ssh);
5623 struct ssh_channel *c;
5624 c = find234(ssh->channels, &i, ssh_channelfind);
5626 continue; /* nonexistent channel */
5627 if (c->type != CHAN_SOCKDATA_DORMANT)
5628 continue; /* dunno why they're failing this */
5630 logevent("Forwarded connection refused by server");
5632 pfd_close(c->u.pfd.s);
5634 del234(ssh->channels, c);
5636 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5639 int typelen, want_reply;
5640 struct ssh_channel *c;
5642 localid = ssh2_pkt_getuint32(ssh);
5643 ssh2_pkt_getstring(ssh, &type, &typelen);
5644 want_reply = ssh2_pkt_getbool(ssh);
5647 * First, check that the channel exists. Otherwise,
5648 * we can instantly disconnect with a rude message.
5650 c = find234(ssh->channels, &localid, ssh_channelfind);
5653 sprintf(buf, "Received channel request for nonexistent"
5654 " channel %d", localid);
5656 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5657 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5658 ssh2_pkt_addstring(ssh, buf);
5659 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5661 connection_fatal("%s", buf);
5662 ssh->state = SSH_STATE_CLOSED;
5667 * Having got the channel number, we now look at
5668 * the request type string to see if it's something
5671 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5672 c == ssh->mainchan) {
5673 /* We recognise "exit-status" on the primary channel. */
5675 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5676 sprintf(buf, "Server sent command exit status %d",
5680 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5681 ssh2_pkt_adduint32(ssh, c->remoteid);
5686 * This is a channel request we don't know
5687 * about, so we now either ignore the request
5688 * or respond with CHANNEL_FAILURE, depending
5692 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5693 ssh2_pkt_adduint32(ssh, c->remoteid);
5697 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5699 int typelen, want_reply;
5701 ssh2_pkt_getstring(ssh, &type, &typelen);
5702 want_reply = ssh2_pkt_getbool(ssh);
5705 * We currently don't support any global requests
5706 * at all, so we either ignore the request or
5707 * respond with REQUEST_FAILURE, depending on
5711 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5714 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5718 struct ssh_channel *c;
5719 unsigned remid, winsize, pktsize;
5720 ssh2_pkt_getstring(ssh, &type, &typelen);
5721 c = smalloc(sizeof(struct ssh_channel));
5724 remid = ssh2_pkt_getuint32(ssh);
5725 winsize = ssh2_pkt_getuint32(ssh);
5726 pktsize = ssh2_pkt_getuint32(ssh);
5728 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5729 if (!ssh->X11_fwd_enabled)
5730 error = "X11 forwarding is not enabled";
5731 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5732 ssh->x11auth) != NULL) {
5733 error = "Unable to open an X11 connection";
5737 } else if (typelen == 15 &&
5738 !memcmp(type, "forwarded-tcpip", 15)) {
5739 struct ssh_rportfwd pf, *realpf;
5742 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5743 pf.sport = ssh2_pkt_getuint32(ssh);
5744 realpf = find234(ssh->rportfwds, &pf, NULL);
5745 if (realpf == NULL) {
5746 error = "Remote port is not recognised";
5748 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5750 logeventf(ssh, "Received remote port open request"
5751 " for %s:%d", realpf->dhost, realpf->dport);
5753 logeventf(ssh, "Port open failed: %s", e);
5754 error = "Port open failed";
5756 logevent("Forwarded port opened successfully");
5757 c->type = CHAN_SOCKDATA;
5760 } else if (typelen == 22 &&
5761 !memcmp(type, "auth-agent@openssh.com", 3)) {
5762 if (!ssh->agentfwd_enabled)
5763 error = "Agent forwarding is not enabled";
5765 c->type = CHAN_AGENT; /* identify channel type */
5766 c->u.a.lensofar = 0;
5769 error = "Unsupported channel type requested";
5772 c->remoteid = remid;
5774 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5775 ssh2_pkt_adduint32(ssh, c->remoteid);
5776 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5777 ssh2_pkt_addstring(ssh, error);
5778 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5782 c->localid = alloc_channel_id(ssh);
5784 c->v.v2.locwindow = OUR_V2_WINSIZE;
5785 c->v.v2.remwindow = winsize;
5786 c->v.v2.remmaxpkt = pktsize;
5787 bufchain_init(&c->v.v2.outbuffer);
5788 add234(ssh->channels, c);
5789 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5790 ssh2_pkt_adduint32(ssh, c->remoteid);
5791 ssh2_pkt_adduint32(ssh, c->localid);
5792 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5793 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5797 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5802 * We have spare data. Add it to the channel buffer.
5804 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
5809 struct ssh_channel *c;
5811 * Try to send data on all channels if we can.
5813 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5816 continue; /* don't send on closing channels */
5817 bufsize = ssh2_try_send(c);
5820 case CHAN_MAINSESSION:
5821 /* stdin need not receive an unthrottle
5822 * notification since it will be polled */
5825 x11_unthrottle(c->u.x11.s);
5828 /* agent sockets are request/response and need no
5829 * buffer management */
5832 pfd_unthrottle(c->u.pfd.s);
5844 * Handle the top-level SSH2 protocol.
5846 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5848 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5850 do_ssh2_authconn(ssh, in, inlen, ispkt);
5854 * Called to set up the connection.
5856 * Returns an error message, or NULL on success.
5858 static char *ssh_init(void *frontend_handle, void **backend_handle,
5859 char *host, int port, char **realhost, int nodelay)
5864 ssh = smalloc(sizeof(*ssh));
5867 ssh->v1_cipher_ctx = NULL;
5868 ssh->crcda_ctx = NULL;
5869 ssh->cscipher = NULL;
5870 ssh->cs_cipher_ctx = NULL;
5871 ssh->sccipher = NULL;
5872 ssh->sc_cipher_ctx = NULL;
5874 ssh->cs_mac_ctx = NULL;
5876 ssh->sc_mac_ctx = NULL;
5878 ssh->cs_comp_ctx = NULL;
5880 ssh->sc_comp_ctx = NULL;
5882 ssh->hostkey = NULL;
5884 ssh->state = SSH_STATE_PREPACKET;
5885 ssh->size_needed = FALSE;
5886 ssh->eof_needed = FALSE;
5890 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5891 ssh->pktin = ssh->pktout = empty;
5893 ssh->deferred_send_data = NULL;
5894 ssh->deferred_len = 0;
5895 ssh->deferred_size = 0;
5896 ssh->fallback_cmd = 0;
5898 ssh->x11auth = NULL;
5899 ssh->v1_compressing = FALSE;
5900 ssh->v2_outgoing_sequence = 0;
5901 ssh->ssh1_rdpkt_crstate = 0;
5902 ssh->ssh2_rdpkt_crstate = 0;
5903 ssh->do_ssh_init_crstate = 0;
5904 ssh->ssh_gotdata_crstate = 0;
5905 ssh->ssh1_protocol_crstate = 0;
5906 ssh->do_ssh1_login_crstate = 0;
5907 ssh->do_ssh2_transport_crstate = 0;
5908 ssh->do_ssh2_authconn_crstate = 0;
5909 ssh->do_ssh_init_state = NULL;
5910 ssh->do_ssh1_login_state = NULL;
5911 ssh->do_ssh2_transport_state = NULL;
5912 ssh->do_ssh2_authconn_state = NULL;
5913 ssh->mainchan = NULL;
5914 ssh->throttled_all = 0;
5915 ssh->v1_stdout_throttling = 0;
5917 *backend_handle = ssh;
5920 if (crypto_startup() == 0)
5921 return "Microsoft high encryption pack not installed!";
5924 ssh->frontend = frontend_handle;
5925 ssh->term_width = cfg.width;
5926 ssh->term_height = cfg.height;
5931 ssh->v1_throttle_count = 0;
5932 ssh->overall_bufsize = 0;
5933 ssh->fallback_cmd = 0;
5935 ssh->protocol = NULL;
5937 p = connect_to_host(ssh, host, port, realhost, nodelay);
5945 * Called to send data down the Telnet connection.
5947 static int ssh_send(void *handle, char *buf, int len)
5949 Ssh ssh = (Ssh) handle;
5951 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5954 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
5956 return ssh_sendbuffer(ssh);
5960 * Called to query the current amount of buffered stdin data.
5962 static int ssh_sendbuffer(void *handle)
5964 Ssh ssh = (Ssh) handle;
5967 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5971 * If the SSH socket itself has backed up, add the total backup
5972 * size on that to any individual buffer on the stdin channel.
5975 if (ssh->throttled_all)
5976 override_value = ssh->overall_bufsize;
5978 if (ssh->version == 1) {
5979 return override_value;
5980 } else if (ssh->version == 2) {
5981 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5982 return override_value;
5984 return (override_value +
5985 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5992 * Called to set the size of the window from SSH's POV.
5994 static void ssh_size(void *handle, int width, int height)
5996 Ssh ssh = (Ssh) handle;
5998 ssh->term_width = width;
5999 ssh->term_height = height;
6001 switch (ssh->state) {
6002 case SSH_STATE_BEFORE_SIZE:
6003 case SSH_STATE_PREPACKET:
6004 case SSH_STATE_CLOSED:
6005 break; /* do nothing */
6006 case SSH_STATE_INTERMED:
6007 ssh->size_needed = TRUE; /* buffer for later */
6009 case SSH_STATE_SESSION:
6011 if (ssh->version == 1) {
6012 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6013 PKT_INT, ssh->term_height,
6014 PKT_INT, ssh->term_width,
6015 PKT_INT, 0, PKT_INT, 0, PKT_END);
6017 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6018 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6019 ssh2_pkt_addstring(ssh, "window-change");
6020 ssh2_pkt_addbool(ssh, 0);
6021 ssh2_pkt_adduint32(ssh, ssh->term_width);
6022 ssh2_pkt_adduint32(ssh, ssh->term_height);
6023 ssh2_pkt_adduint32(ssh, 0);
6024 ssh2_pkt_adduint32(ssh, 0);
6033 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6034 * can send an EOF and collect resulting output (e.g. `plink
6037 static void ssh_special(void *handle, Telnet_Special code)
6039 Ssh ssh = (Ssh) handle;
6041 if (code == TS_EOF) {
6042 if (ssh->state != SSH_STATE_SESSION) {
6044 * Buffer the EOF in case we are pre-SESSION, so we can
6045 * send it as soon as we reach SESSION.
6048 ssh->eof_needed = TRUE;
6051 if (ssh->version == 1) {
6052 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6054 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6055 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6058 logevent("Sent EOF message");
6059 } else if (code == TS_PING) {
6060 if (ssh->state == SSH_STATE_CLOSED
6061 || ssh->state == SSH_STATE_PREPACKET) return;
6062 if (ssh->version == 1) {
6063 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6064 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6066 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6067 ssh2_pkt_addstring_start(ssh);
6075 void *new_sock_channel(void *handle, Socket s)
6077 Ssh ssh = (Ssh) handle;
6078 struct ssh_channel *c;
6079 c = smalloc(sizeof(struct ssh_channel));
6083 c->remoteid = -1; /* to be set when open confirmed */
6084 c->localid = alloc_channel_id(ssh);
6086 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6088 bufchain_init(&c->v.v2.outbuffer);
6089 add234(ssh->channels, c);
6095 * This is called when stdout/stderr (the entity to which
6096 * from_backend sends data) manages to clear some backlog.
6098 static void ssh_unthrottle(void *handle, int bufsize)
6100 Ssh ssh = (Ssh) handle;
6101 if (ssh->version == 1) {
6102 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6103 ssh->v1_stdout_throttling = 0;
6104 ssh1_throttle(ssh, -1);
6107 if (ssh->mainchan && ssh->mainchan->closes == 0)
6108 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6112 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6114 struct ssh_channel *c = (struct ssh_channel *)channel;
6117 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6119 if (ssh->version == 1) {
6120 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6121 PKT_INT, c->localid,
6124 //PKT_STR, <org:orgport>,
6127 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6128 ssh2_pkt_addstring(ssh, "direct-tcpip");
6129 ssh2_pkt_adduint32(ssh, c->localid);
6130 c->v.v2.locwindow = OUR_V2_WINSIZE;
6131 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6132 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6133 ssh2_pkt_addstring(ssh, hostname);
6134 ssh2_pkt_adduint32(ssh, port);
6136 * We make up values for the originator data; partly it's
6137 * too much hassle to keep track, and partly I'm not
6138 * convinced the server should be told details like that
6139 * about my local network configuration.
6141 ssh2_pkt_addstring(ssh, "client-side-connection");
6142 ssh2_pkt_adduint32(ssh, 0);
6148 static Socket ssh_socket(void *handle)
6150 Ssh ssh = (Ssh) handle;
6154 static int ssh_sendok(void *handle)
6156 Ssh ssh = (Ssh) handle;
6157 return ssh->send_ok;
6160 static int ssh_ldisc(void *handle, int option)
6162 Ssh ssh = (Ssh) handle;
6163 if (option == LD_ECHO)
6164 return ssh->echoing;
6165 if (option == LD_EDIT)
6166 return ssh->editing;
6170 static void ssh_provide_ldisc(void *handle, void *ldisc)
6172 Ssh ssh = (Ssh) handle;
6176 static void ssh_provide_logctx(void *handle, void *logctx)
6178 Ssh ssh = (Ssh) handle;
6179 ssh->logctx = logctx;
6182 static int ssh_return_exitcode(void *handle)
6184 Ssh ssh = (Ssh) handle;
6185 return ssh->exitcode;
6189 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6190 * that fails. This variable is the means by which scp.c can reach
6191 * into the SSH code and find out which one it got.
6193 extern int ssh_fallback_cmd(void *handle)
6195 Ssh ssh = (Ssh) handle;
6196 return ssh->fallback_cmd;
6199 Backend ssh_backend = {
6206 ssh_return_exitcode,