18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 /* logevent, only printf-formatted. */
23 void logeventf(char *fmt, ...)
29 vsprintf(stuff, fmt, ap);
34 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
35 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
36 logeventf msg, connection_fatal msg )
38 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41 #define SSH1_CMSG_USER 4 /* 0x4 */
42 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
51 #define SSH1_SMSG_FAILURE 15 /* 0xf */
52 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55 #define SSH1_CMSG_EOF 19 /* 0x13 */
56 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67 #define SSH1_MSG_IGNORE 32 /* 0x20 */
68 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71 #define SSH1_MSG_DEBUG 36 /* 0x24 */
72 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
80 #define SSH1_AUTH_TIS 5 /* 0x5 */
81 #define SSH1_AUTH_CCARD 16 /* 0x10 */
83 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
84 /* Mask for protoflags we will echo back to server if seen */
85 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
87 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88 #define SSH2_MSG_IGNORE 2 /* 0x2 */
89 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90 #define SSH2_MSG_DEBUG 4 /* 0x4 */
91 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
94 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
107 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
109 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
128 #define SSH2_PKTCTX_DHGROUP1 0x0001
129 #define SSH2_PKTCTX_DHGEX 0x0002
130 #define SSH2_PKTCTX_PUBLICKEY 0x0010
131 #define SSH2_PKTCTX_PASSWORD 0x0020
132 #define SSH2_PKTCTX_KBDINTER 0x0040
133 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
135 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
151 static const char *const ssh2_disconnect_reasons[] = {
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
170 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
175 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
178 * Various remote-bug flags.
180 #define BUG_CHOKES_ON_SSH1_IGNORE 1
181 #define BUG_SSH2_HMAC 2
182 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
183 #define BUG_CHOKES_ON_RSA 8
184 #define BUG_SSH2_RSA_PADDING 16
185 #define BUG_SSH2_DERIVEKEY 32
186 #define BUG_SSH2_DH_GEX 64
188 #define translate(x) if (type == x) return #x
189 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
190 char *ssh1_pkt_type(int type)
192 translate(SSH1_MSG_DISCONNECT);
193 translate(SSH1_SMSG_PUBLIC_KEY);
194 translate(SSH1_CMSG_SESSION_KEY);
195 translate(SSH1_CMSG_USER);
196 translate(SSH1_CMSG_AUTH_RSA);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
199 translate(SSH1_CMSG_AUTH_PASSWORD);
200 translate(SSH1_CMSG_REQUEST_PTY);
201 translate(SSH1_CMSG_WINDOW_SIZE);
202 translate(SSH1_CMSG_EXEC_SHELL);
203 translate(SSH1_CMSG_EXEC_CMD);
204 translate(SSH1_SMSG_SUCCESS);
205 translate(SSH1_SMSG_FAILURE);
206 translate(SSH1_CMSG_STDIN_DATA);
207 translate(SSH1_SMSG_STDOUT_DATA);
208 translate(SSH1_SMSG_STDERR_DATA);
209 translate(SSH1_CMSG_EOF);
210 translate(SSH1_SMSG_EXIT_STATUS);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
213 translate(SSH1_MSG_CHANNEL_DATA);
214 translate(SSH1_MSG_CHANNEL_CLOSE);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
216 translate(SSH1_SMSG_X11_OPEN);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
218 translate(SSH1_MSG_PORT_OPEN);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
220 translate(SSH1_SMSG_AGENT_OPEN);
221 translate(SSH1_MSG_IGNORE);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
225 translate(SSH1_MSG_DEBUG);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION);
227 translate(SSH1_CMSG_AUTH_TIS);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
230 translate(SSH1_CMSG_AUTH_CCARD);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
235 char *ssh2_pkt_type(int pkt_ctx, int type)
237 translate(SSH2_MSG_DISCONNECT);
238 translate(SSH2_MSG_IGNORE);
239 translate(SSH2_MSG_UNIMPLEMENTED);
240 translate(SSH2_MSG_DEBUG);
241 translate(SSH2_MSG_SERVICE_REQUEST);
242 translate(SSH2_MSG_SERVICE_ACCEPT);
243 translate(SSH2_MSG_KEXINIT);
244 translate(SSH2_MSG_NEWKEYS);
245 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
251 translate(SSH2_MSG_USERAUTH_REQUEST);
252 translate(SSH2_MSG_USERAUTH_FAILURE);
253 translate(SSH2_MSG_USERAUTH_SUCCESS);
254 translate(SSH2_MSG_USERAUTH_BANNER);
255 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
259 translate(SSH2_MSG_GLOBAL_REQUEST);
260 translate(SSH2_MSG_REQUEST_SUCCESS);
261 translate(SSH2_MSG_REQUEST_FAILURE);
262 translate(SSH2_MSG_CHANNEL_OPEN);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
266 translate(SSH2_MSG_CHANNEL_DATA);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
268 translate(SSH2_MSG_CHANNEL_EOF);
269 translate(SSH2_MSG_CHANNEL_CLOSE);
270 translate(SSH2_MSG_CHANNEL_REQUEST);
271 translate(SSH2_MSG_CHANNEL_SUCCESS);
272 translate(SSH2_MSG_CHANNEL_FAILURE);
278 #define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
284 #define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
290 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
292 /* Coroutine mechanics for the sillier bits of the code */
293 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
296 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
298 #define crFinish(z) } *crLine = 0; return (z); }
299 #define crFinishV } *crLine = 0; return; }
300 #define crReturn(z) \
302 *crLine =__LINE__; return (z); case __LINE__:;\
306 *crLine=__LINE__; return; case __LINE__:;\
308 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
309 #define crStopV do{ *crLine = 0; return; }while(0)
310 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
311 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
313 typedef struct ssh_tag *Ssh;
315 extern char *x11_init(Socket *, char *, void *, void *);
316 extern void x11_close(Socket);
317 extern int x11_send(Socket, char *, int);
318 extern void *x11_invent_auth(char *, int, char *, int);
319 extern void x11_unthrottle(Socket s);
320 extern void x11_override_throttle(Socket s, int enable);
322 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
323 extern char *pfd_addforward(char *desthost, int destport, int port,
325 extern void pfd_close(Socket s);
326 extern int pfd_send(Socket s, char *data, int len);
327 extern void pfd_confirm(Socket s);
328 extern void pfd_unthrottle(Socket s);
329 extern void pfd_override_throttle(Socket s, int enable);
331 static void ssh2_pkt_init(Ssh, int pkt_type);
332 static void ssh2_pkt_addbool(Ssh, unsigned char value);
333 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
334 static void ssh2_pkt_addstring_start(Ssh);
335 static void ssh2_pkt_addstring_str(Ssh, char *data);
336 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
337 static void ssh2_pkt_addstring(Ssh, char *data);
338 static char *ssh2_mpint_fmt(Bignum b, int *len);
339 static void ssh2_pkt_addmp(Ssh, Bignum b);
340 static int ssh2_pkt_construct(Ssh);
341 static void ssh2_pkt_send(Ssh);
344 * Buffer management constants. There are several of these for
345 * various different purposes:
347 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
348 * on a local data stream before we throttle the whole SSH
349 * connection (in SSH1 only). Throttling the whole connection is
350 * pretty drastic so we set this high in the hope it won't
353 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
354 * on the SSH connection itself before we defensively throttle
355 * _all_ local data streams. This is pretty drastic too (though
356 * thankfully unlikely in SSH2 since the window mechanism should
357 * ensure that the server never has any need to throttle its end
358 * of the connection), so we set this high as well.
360 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
364 #define SSH1_BUFFER_LIMIT 32768
365 #define SSH_MAX_BACKLOG 32768
366 #define OUR_V2_WINSIZE 16384
368 const static struct ssh_kex *kex_algs[] = {
369 &ssh_diffiehellman_gex,
373 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
375 static void *nullmac_make_context(void)
379 static void nullmac_free_context(void *handle)
382 static void nullmac_key(void *handle, unsigned char *key)
385 static void nullmac_generate(void *handle, unsigned char *blk, int len,
389 static int nullmac_verify(void *handle, unsigned char *blk, int len,
394 const static struct ssh_mac ssh_mac_none = {
395 nullmac_make_context, nullmac_free_context, nullmac_key,
396 nullmac_generate, nullmac_verify, "none", 0
398 const static struct ssh_mac *macs[] = {
399 &ssh_sha1, &ssh_md5, &ssh_mac_none
401 const static struct ssh_mac *buggymacs[] = {
402 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
405 static void *ssh_comp_none_init(void)
409 static void ssh_comp_none_cleanup(void *handle)
412 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
413 unsigned char **outblock, int *outlen)
417 static int ssh_comp_none_disable(void *handle)
421 const static struct ssh_compress ssh_comp_none = {
423 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
424 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
425 ssh_comp_none_disable, NULL
427 extern const struct ssh_compress ssh_zlib;
428 const static struct ssh_compress *compressions[] = {
429 &ssh_zlib, &ssh_comp_none
432 enum { /* channel types */
437 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
441 * 2-3-4 tree storing channels.
444 Ssh ssh; /* pointer back to main context */
445 unsigned remoteid, localid;
448 * In SSH1, this value contains four bits:
450 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
451 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
452 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
453 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
455 * A channel is completely finished with when all four bits are set.
459 struct ssh1_data_channel {
462 struct ssh2_data_channel {
464 unsigned remwindow, remmaxpkt;
469 struct ssh_agent_channel {
470 unsigned char *message;
471 unsigned char msglen[4];
472 int lensofar, totallen;
474 struct ssh_x11_channel {
477 struct ssh_pfd_channel {
484 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
485 * 2 use this structure in different ways, reflecting SSH 2's
486 * altogether saner approach to port forwarding.
488 * In SSH 1, you arrange a remote forwarding by sending the server
489 * the remote port number, and the local destination host:port.
490 * When a connection comes in, the server sends you back that
491 * host:port pair, and you connect to it. This is a ready-made
492 * security hole if you're not on the ball: a malicious server
493 * could send you back _any_ host:port pair, so if you trustingly
494 * connect to the address it gives you then you've just opened the
495 * entire inside of your corporate network just by connecting
496 * through it to a dodgy SSH server. Hence, we must store a list of
497 * host:port pairs we _are_ trying to forward to, and reject a
498 * connection request from the server if it's not in the list.
500 * In SSH 2, each side of the connection minds its own business and
501 * doesn't send unnecessary information to the other. You arrange a
502 * remote forwarding by sending the server just the remote port
503 * number. When a connection comes in, the server tells you which
504 * of its ports was connected to; and _you_ have to remember what
505 * local host:port pair went with that port number.
507 * Hence: in SSH 1 this structure stores host:port pairs we intend
508 * to allow connections to, and is indexed by those host:port
509 * pairs. In SSH 2 it stores a mapping from source port to
510 * destination host:port pair, and is indexed by source port.
512 struct ssh_rportfwd {
513 unsigned sport, dport;
526 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
527 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
528 static void ssh_size(void *handle, int width, int height);
529 static void ssh_special(void *handle, Telnet_Special);
530 static int ssh2_try_send(struct ssh_channel *c);
531 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
532 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
533 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
534 static int ssh_sendbuffer(void *handle);
536 struct rdpkt1_state_tag {
537 long len, pad, biglen, to_read;
538 unsigned long realcrc, gotcrc;
544 struct rdpkt2_state_tag {
545 long len, pad, payload, packetlen, maclen;
548 unsigned long incoming_sequence;
552 const struct plug_function_table *fn;
553 /* the above field _must_ be first in the structure */
555 SHA_State exhash, exhashbase;
561 unsigned char session_key[32];
563 int v1_remote_protoflags;
564 int v1_local_protoflags;
565 int agentfwd_enabled;
568 const struct ssh_cipher *cipher;
571 const struct ssh2_cipher *cscipher, *sccipher;
572 void *cs_cipher_ctx, *sc_cipher_ctx;
573 const struct ssh_mac *csmac, *scmac;
574 void *cs_mac_ctx, *sc_mac_ctx;
575 const struct ssh_compress *cscomp, *sccomp;
576 void *cs_comp_ctx, *sc_comp_ctx;
577 const struct ssh_kex *kex;
578 const struct ssh_signkey *hostkey;
579 unsigned char v2_session_id[20];
585 int echoing, editing;
589 int term_width, term_height;
591 tree234 *channels; /* indexed by local id */
592 struct ssh_channel *mainchan; /* primary session channel */
599 SSH_STATE_BEFORE_SIZE,
605 int size_needed, eof_needed;
608 struct Packet pktout;
609 unsigned char *deferred_send_data;
610 int deferred_len, deferred_size;
613 * Gross hack: pscp will try to start SFTP but fall back to
614 * scp1 if that fails. This variable is the means by which
615 * scp.c can reach into the SSH code and find out which one it
621 * Used for username and password input.
623 char *userpass_input_buffer;
624 int userpass_input_buflen;
625 int userpass_input_bufpos;
626 int userpass_input_echo;
628 char *portfwd_strptr;
634 int v1_throttle_count;
637 int v1_stdout_throttling;
638 int v2_outgoing_sequence;
640 int ssh1_rdpkt_crstate;
641 int ssh2_rdpkt_crstate;
642 int do_ssh_init_crstate;
643 int ssh_gotdata_crstate;
644 int ssh1_protocol_crstate;
645 int do_ssh1_login_crstate;
646 int do_ssh2_transport_crstate;
647 int do_ssh2_authconn_crstate;
649 void *do_ssh_init_state;
650 void *do_ssh1_login_state;
651 void *do_ssh2_transport_state;
652 void *do_ssh2_authconn_state;
654 struct rdpkt1_state_tag rdpkt1_state;
655 struct rdpkt2_state_tag rdpkt2_state;
657 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
658 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
661 static int ssh_channelcmp(void *av, void *bv)
663 struct ssh_channel *a = (struct ssh_channel *) av;
664 struct ssh_channel *b = (struct ssh_channel *) bv;
665 if (a->localid < b->localid)
667 if (a->localid > b->localid)
671 static int ssh_channelfind(void *av, void *bv)
673 unsigned *a = (unsigned *) av;
674 struct ssh_channel *b = (struct ssh_channel *) bv;
682 static int ssh_rportcmp_ssh1(void *av, void *bv)
684 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
685 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
687 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
688 return i < 0 ? -1 : +1;
689 if (a->dport > b->dport)
691 if (a->dport < b->dport)
696 static int ssh_rportcmp_ssh2(void *av, void *bv)
698 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
699 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
701 if (a->sport > b->sport)
703 if (a->sport < b->sport)
708 static int alloc_channel_id(Ssh ssh)
710 const unsigned CHANNEL_NUMBER_OFFSET = 256;
711 unsigned low, high, mid;
713 struct ssh_channel *c;
716 * First-fit allocation of channel numbers: always pick the
717 * lowest unused one. To do this, binary-search using the
718 * counted B-tree to find the largest channel ID which is in a
719 * contiguous sequence from the beginning. (Precisely
720 * everything in that sequence must have ID equal to its tree
721 * index plus CHANNEL_NUMBER_OFFSET.)
723 tsize = count234(ssh->channels);
727 while (high - low > 1) {
728 mid = (high + low) / 2;
729 c = index234(ssh->channels, mid);
730 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
731 low = mid; /* this one is fine */
733 high = mid; /* this one is past it */
736 * Now low points to either -1, or the tree index of the
737 * largest ID in the initial sequence.
740 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
741 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
743 return low + 1 + CHANNEL_NUMBER_OFFSET;
746 static void c_write(Ssh ssh, char *buf, int len)
748 if ((flags & FLAG_STDERR)) {
750 for (i = 0; i < len; i++)
752 fputc(buf[i], stderr);
755 from_backend(ssh->frontend, 1, buf, len);
758 static void c_write_untrusted(Ssh ssh, char *buf, int len)
761 for (i = 0; i < len; i++) {
763 c_write(ssh, "\r\n", 2);
764 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
765 c_write(ssh, buf + i, 1);
769 static void c_write_str(Ssh ssh, char *buf)
771 c_write(ssh, buf, strlen(buf));
775 * Collect incoming data in the incoming packet buffer.
776 * Decipher and verify the packet when it is completely read.
777 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
778 * Update the *data and *datalen variables.
779 * Return the additional nr of bytes needed, or 0 when
780 * a complete packet is available.
782 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
784 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
786 crBegin(ssh->ssh1_rdpkt_crstate);
791 ssh->pktin.length = 0;
793 for (st->i = st->len = 0; st->i < 4; st->i++) {
794 while ((*datalen) == 0)
796 st->len = (st->len << 8) + **data;
797 (*data)++, (*datalen)--;
800 st->pad = 8 - (st->len % 8);
801 st->biglen = st->len + st->pad;
802 ssh->pktin.length = st->len - 5;
804 if (ssh->pktin.maxlen < st->biglen) {
805 ssh->pktin.maxlen = st->biglen;
806 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
809 st->to_read = st->biglen;
810 st->p = ssh->pktin.data;
811 while (st->to_read > 0) {
812 st->chunk = st->to_read;
813 while ((*datalen) == 0)
814 crReturn(st->to_read);
815 if (st->chunk > (*datalen))
816 st->chunk = (*datalen);
817 memcpy(st->p, *data, st->chunk);
819 *datalen -= st->chunk;
821 st->to_read -= st->chunk;
824 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
826 bombout(("Network attack (CRC compensation) detected!"));
831 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
833 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
834 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
835 if (st->gotcrc != st->realcrc) {
836 bombout(("Incorrect CRC received on packet"));
840 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
842 if (ssh->v1_compressing) {
843 unsigned char *decompblk;
845 zlib_decompress_block(ssh->sc_comp_ctx,
846 ssh->pktin.body - 1, ssh->pktin.length + 1,
847 &decompblk, &decomplen);
849 if (ssh->pktin.maxlen < st->pad + decomplen) {
850 ssh->pktin.maxlen = st->pad + decomplen;
851 ssh->pktin.data = srealloc(ssh->pktin.data,
852 ssh->pktin.maxlen + APIEXTRA);
853 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
856 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
858 ssh->pktin.length = decomplen - 1;
861 ssh->pktin.type = ssh->pktin.body[-1];
863 log_packet(PKT_INCOMING, ssh->pktin.type, ssh1_pkt_type(ssh->pktin.type),
864 ssh->pktin.body, ssh->pktin.length);
866 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
867 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
868 ssh->pktin.type == SSH1_MSG_DEBUG ||
869 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
870 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
871 long stringlen = GET_32BIT(ssh->pktin.body);
872 if (stringlen + 4 != ssh->pktin.length) {
873 bombout(("Received data packet with bogus string length"));
878 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
879 /* log debug message */
881 int stringlen = GET_32BIT(ssh->pktin.body);
882 strcpy(buf, "Remote debug message: ");
885 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
886 buf[8 + stringlen] = '\0';
889 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
894 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
895 /* log reason code in disconnect message */
897 unsigned msglen = GET_32BIT(ssh->pktin.body);
899 strcpy(buf, "Remote sent disconnect: ");
900 nowlen = strlen(buf);
901 if (msglen > sizeof(buf) - nowlen - 1)
902 msglen = sizeof(buf) - nowlen - 1;
903 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
904 buf[nowlen + msglen] = '\0';
905 /* logevent(buf); (this is now done within the bombout macro) */
906 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
913 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
915 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
917 crBegin(ssh->ssh2_rdpkt_crstate);
921 ssh->pktin.length = 0;
923 st->cipherblk = ssh->sccipher->blksize;
926 if (st->cipherblk < 8)
929 if (ssh->pktin.maxlen < st->cipherblk) {
930 ssh->pktin.maxlen = st->cipherblk;
931 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
935 * Acquire and decrypt the first block of the packet. This will
936 * contain the length and padding details.
938 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
939 while ((*datalen) == 0)
940 crReturn(st->cipherblk - st->i);
941 ssh->pktin.data[st->i] = *(*data)++;
946 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
947 ssh->pktin.data, st->cipherblk);
950 * Now get the length and padding figures.
952 st->len = GET_32BIT(ssh->pktin.data);
953 st->pad = ssh->pktin.data[4];
956 * _Completely_ silly lengths should be stomped on before they
957 * do us any more damage.
959 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
960 bombout(("Incoming packet was garbled on decryption"));
965 * This enables us to deduce the payload length.
967 st->payload = st->len - st->pad - 1;
969 ssh->pktin.length = st->payload + 5;
972 * So now we can work out the total packet length.
974 st->packetlen = st->len + 4;
975 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
978 * Adjust memory allocation if packet is too big.
980 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
981 ssh->pktin.maxlen = st->packetlen + st->maclen;
982 ssh->pktin.data = srealloc(ssh->pktin.data,
983 ssh->pktin.maxlen + APIEXTRA);
987 * Read and decrypt the remainder of the packet.
989 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
991 while ((*datalen) == 0)
992 crReturn(st->packetlen + st->maclen - st->i);
993 ssh->pktin.data[st->i] = *(*data)++;
996 /* Decrypt everything _except_ the MAC. */
998 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
999 ssh->pktin.data + st->cipherblk,
1000 st->packetlen - st->cipherblk);
1006 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1007 st->incoming_sequence)) {
1008 bombout(("Incorrect MAC received on packet"));
1011 st->incoming_sequence++; /* whether or not we MACed */
1014 * Decompress packet payload.
1017 unsigned char *newpayload;
1020 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1021 ssh->pktin.data + 5, ssh->pktin.length - 5,
1022 &newpayload, &newlen)) {
1023 if (ssh->pktin.maxlen < newlen + 5) {
1024 ssh->pktin.maxlen = newlen + 5;
1025 ssh->pktin.data = srealloc(ssh->pktin.data,
1026 ssh->pktin.maxlen + APIEXTRA);
1028 ssh->pktin.length = 5 + newlen;
1029 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1034 ssh->pktin.savedpos = 6;
1035 ssh->pktin.type = ssh->pktin.data[5];
1037 log_packet(PKT_INCOMING, ssh->pktin.type,
1038 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1039 ssh->pktin.data+6, ssh->pktin.length-6);
1041 switch (ssh->pktin.type) {
1043 * These packets we must handle instantly.
1045 case SSH2_MSG_DISCONNECT:
1047 /* log reason code in disconnect message */
1049 int reason = GET_32BIT(ssh->pktin.data + 6);
1050 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1052 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1053 sprintf(buf, "Received disconnect message (%s)",
1054 ssh2_disconnect_reasons[reason]);
1056 sprintf(buf, "Received disconnect message (unknown type %d)",
1060 strcpy(buf, "Disconnection message text: ");
1061 nowlen = strlen(buf);
1062 if (msglen > sizeof(buf) - nowlen - 1)
1063 msglen = sizeof(buf) - nowlen - 1;
1064 memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
1065 buf[nowlen + msglen] = '\0';
1067 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1069 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1070 ssh2_disconnect_reasons[reason] : "unknown",
1075 case SSH2_MSG_IGNORE:
1077 case SSH2_MSG_DEBUG:
1079 /* log the debug message */
1081 /* int display = ssh->pktin.body[6]; */
1082 int stringlen = GET_32BIT(ssh->pktin.data+7);
1084 strcpy(buf, "Remote debug message: ");
1085 prefix = strlen(buf);
1086 if (stringlen > (int)(sizeof(buf)-prefix-1))
1087 stringlen = sizeof(buf)-prefix-1;
1088 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1089 buf[prefix + stringlen] = '\0';
1092 goto next_packet; /* FIXME: print the debug message */
1095 * These packets we need do nothing about here.
1097 case SSH2_MSG_UNIMPLEMENTED:
1098 case SSH2_MSG_SERVICE_REQUEST:
1099 case SSH2_MSG_SERVICE_ACCEPT:
1100 case SSH2_MSG_KEXINIT:
1101 case SSH2_MSG_NEWKEYS:
1102 case SSH2_MSG_KEXDH_INIT:
1103 case SSH2_MSG_KEXDH_REPLY:
1104 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1105 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1106 case SSH2_MSG_KEX_DH_GEX_INIT:
1107 case SSH2_MSG_KEX_DH_GEX_REPLY:
1108 case SSH2_MSG_USERAUTH_REQUEST:
1109 case SSH2_MSG_USERAUTH_FAILURE:
1110 case SSH2_MSG_USERAUTH_SUCCESS:
1111 case SSH2_MSG_USERAUTH_BANNER:
1112 case SSH2_MSG_USERAUTH_PK_OK:
1113 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1114 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1115 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1116 case SSH2_MSG_GLOBAL_REQUEST:
1117 case SSH2_MSG_REQUEST_SUCCESS:
1118 case SSH2_MSG_REQUEST_FAILURE:
1119 case SSH2_MSG_CHANNEL_OPEN:
1120 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1121 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1122 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1123 case SSH2_MSG_CHANNEL_DATA:
1124 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1125 case SSH2_MSG_CHANNEL_EOF:
1126 case SSH2_MSG_CHANNEL_CLOSE:
1127 case SSH2_MSG_CHANNEL_REQUEST:
1128 case SSH2_MSG_CHANNEL_SUCCESS:
1129 case SSH2_MSG_CHANNEL_FAILURE:
1133 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1136 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1137 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1145 static void ssh1_pktout_size(Ssh ssh, int len)
1149 len += 5; /* type and CRC */
1150 pad = 8 - (len % 8);
1153 ssh->pktout.length = len - 5;
1154 if (ssh->pktout.maxlen < biglen) {
1155 ssh->pktout.maxlen = biglen;
1157 /* Allocate enough buffer space for extra block
1158 * for MS CryptEncrypt() */
1159 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1161 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1164 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1167 static void s_wrpkt_start(Ssh ssh, int type, int len)
1169 ssh1_pktout_size(ssh, len);
1170 ssh->pktout.type = type;
1173 static int s_wrpkt_prepare(Ssh ssh)
1175 int pad, len, biglen, i;
1178 ssh->pktout.body[-1] = ssh->pktout.type;
1180 log_packet(PKT_OUTGOING, ssh->pktout.type, ssh1_pkt_type(ssh->pktout.type),
1181 ssh->pktout.body, ssh->pktout.length);
1183 if (ssh->v1_compressing) {
1184 unsigned char *compblk;
1186 zlib_compress_block(ssh->cs_comp_ctx,
1187 ssh->pktout.body - 1, ssh->pktout.length + 1,
1188 &compblk, &complen);
1189 ssh1_pktout_size(ssh, complen - 1);
1190 memcpy(ssh->pktout.body - 1, compblk, complen);
1194 len = ssh->pktout.length + 5; /* type and CRC */
1195 pad = 8 - (len % 8);
1198 for (i = 0; i < pad; i++)
1199 ssh->pktout.data[i + 4] = random_byte();
1200 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1201 PUT_32BIT(ssh->pktout.data + biglen, crc);
1202 PUT_32BIT(ssh->pktout.data, len);
1205 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1210 static void s_wrpkt(Ssh ssh)
1213 len = s_wrpkt_prepare(ssh);
1214 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1215 if (backlog > SSH_MAX_BACKLOG)
1216 ssh_throttle_all(ssh, 1, backlog);
1219 static void s_wrpkt_defer(Ssh ssh)
1222 len = s_wrpkt_prepare(ssh);
1223 if (ssh->deferred_len + len > ssh->deferred_size) {
1224 ssh->deferred_size = ssh->deferred_len + len + 128;
1225 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1226 ssh->deferred_size);
1228 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1229 ssh->deferred_len += len;
1233 * Construct a packet with the specified contents.
1235 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1237 unsigned char *p, *argp, argchar;
1238 unsigned long argint;
1239 int pktlen, argtype, arglen;
1243 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1246 (void) va_arg(ap1, int);
1250 (void) va_arg(ap1, char);
1254 (void) va_arg(ap1, unsigned char *);
1255 arglen = va_arg(ap1, int);
1259 argp = va_arg(ap1, unsigned char *);
1260 arglen = strlen(argp);
1261 pktlen += 4 + arglen;
1264 bn = va_arg(ap1, Bignum);
1265 pktlen += ssh1_bignum_length(bn);
1272 s_wrpkt_start(ssh, pkttype, pktlen);
1273 p = ssh->pktout.body;
1275 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1278 argint = va_arg(ap2, int);
1279 PUT_32BIT(p, argint);
1283 argchar = va_arg(ap2, unsigned char);
1288 argp = va_arg(ap2, unsigned char *);
1289 arglen = va_arg(ap2, int);
1290 memcpy(p, argp, arglen);
1294 argp = va_arg(ap2, unsigned char *);
1295 arglen = strlen(argp);
1296 PUT_32BIT(p, arglen);
1297 memcpy(p + 4, argp, arglen);
1301 bn = va_arg(ap2, Bignum);
1302 p += ssh1_write_bignum(p, bn);
1308 static void send_packet(Ssh ssh, int pkttype, ...)
1311 va_start(ap1, pkttype);
1312 va_start(ap2, pkttype);
1313 construct_packet(ssh, pkttype, ap1, ap2);
1317 static void defer_packet(Ssh ssh, int pkttype, ...)
1320 va_start(ap1, pkttype);
1321 va_start(ap2, pkttype);
1322 construct_packet(ssh, pkttype, ap1, ap2);
1326 static int ssh_versioncmp(char *a, char *b)
1329 unsigned long av, bv;
1331 av = strtoul(a, &ae, 10);
1332 bv = strtoul(b, &be, 10);
1334 return (av < bv ? -1 : +1);
1339 av = strtoul(ae, &ae, 10);
1340 bv = strtoul(be, &be, 10);
1342 return (av < bv ? -1 : +1);
1347 * Utility routines for putting an SSH-protocol `string' and
1348 * `uint32' into a SHA state.
1351 static void sha_string(SHA_State * s, void *str, int len)
1353 unsigned char lenblk[4];
1354 PUT_32BIT(lenblk, len);
1355 SHA_Bytes(s, lenblk, 4);
1356 SHA_Bytes(s, str, len);
1359 static void sha_uint32(SHA_State * s, unsigned i)
1361 unsigned char intblk[4];
1362 PUT_32BIT(intblk, i);
1363 SHA_Bytes(s, intblk, 4);
1367 * SSH2 packet construction functions.
1369 static void ssh2_pkt_ensure(Ssh ssh, int length)
1371 if (ssh->pktout.maxlen < length) {
1372 ssh->pktout.maxlen = length + 256;
1373 ssh->pktout.data = srealloc(ssh->pktout.data,
1374 ssh->pktout.maxlen + APIEXTRA);
1375 if (!ssh->pktout.data)
1376 fatalbox("Out of memory");
1379 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1381 ssh->pktout.length += len;
1382 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1383 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1385 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1387 ssh2_pkt_adddata(ssh, &byte, 1);
1389 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1391 ssh->pktout.length = 5;
1392 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1394 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1396 ssh2_pkt_adddata(ssh, &value, 1);
1398 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1401 PUT_32BIT(x, value);
1402 ssh2_pkt_adddata(ssh, x, 4);
1404 static void ssh2_pkt_addstring_start(Ssh ssh)
1406 ssh2_pkt_adduint32(ssh, 0);
1407 ssh->pktout.savedpos = ssh->pktout.length;
1409 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1411 ssh2_pkt_adddata(ssh, data, strlen(data));
1412 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1413 ssh->pktout.length - ssh->pktout.savedpos);
1415 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1417 ssh2_pkt_adddata(ssh, data, len);
1418 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1419 ssh->pktout.length - ssh->pktout.savedpos);
1421 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1423 ssh2_pkt_addstring_start(ssh);
1424 ssh2_pkt_addstring_str(ssh, data);
1426 static char *ssh2_mpint_fmt(Bignum b, int *len)
1429 int i, n = (bignum_bitcount(b) + 7) / 8;
1432 fatalbox("out of memory");
1434 for (i = 1; i <= n; i++)
1435 p[i] = bignum_byte(b, n - i);
1437 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1439 memmove(p, p + i, n + 1 - i);
1443 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1447 p = ssh2_mpint_fmt(b, &len);
1448 ssh2_pkt_addstring_start(ssh);
1449 ssh2_pkt_addstring_data(ssh, p, len);
1454 * Construct an SSH2 final-form packet: compress it, encrypt it,
1455 * put the MAC on it. Final packet, ready to be sent, is stored in
1456 * ssh->pktout.data. Total length is returned.
1458 static int ssh2_pkt_construct(Ssh ssh)
1460 int cipherblk, maclen, padding, i;
1462 log_packet(PKT_OUTGOING, ssh->pktout.data[5],
1463 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1464 ssh->pktout.data + 6, ssh->pktout.length - 6);
1467 * Compress packet payload.
1470 unsigned char *newpayload;
1473 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1474 ssh->pktout.length - 5,
1475 &newpayload, &newlen)) {
1476 ssh->pktout.length = 5;
1477 ssh2_pkt_adddata(ssh, newpayload, newlen);
1483 * Add padding. At least four bytes, and must also bring total
1484 * length (minus MAC) up to a multiple of the block size.
1486 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1487 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1490 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1491 maclen = ssh->csmac ? ssh->csmac->len : 0;
1492 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1493 ssh->pktout.data[4] = padding;
1494 for (i = 0; i < padding; i++)
1495 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1496 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1498 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1499 ssh->pktout.length + padding,
1500 ssh->v2_outgoing_sequence);
1501 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1504 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1505 ssh->pktout.data, ssh->pktout.length + padding);
1507 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1508 return ssh->pktout.length + padding + maclen;
1512 * Construct and send an SSH2 packet immediately.
1514 static void ssh2_pkt_send(Ssh ssh)
1518 len = ssh2_pkt_construct(ssh);
1519 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1520 if (backlog > SSH_MAX_BACKLOG)
1521 ssh_throttle_all(ssh, 1, backlog);
1525 * Construct an SSH2 packet and add it to a deferred data block.
1526 * Useful for sending multiple packets in a single sk_write() call,
1527 * to prevent a traffic-analysing listener from being able to work
1528 * out the length of any particular packet (such as the password
1531 * Note that because SSH2 sequence-numbers its packets, this can
1532 * NOT be used as an m4-style `defer' allowing packets to be
1533 * constructed in one order and sent in another.
1535 static void ssh2_pkt_defer(Ssh ssh)
1537 int len = ssh2_pkt_construct(ssh);
1538 if (ssh->deferred_len + len > ssh->deferred_size) {
1539 ssh->deferred_size = ssh->deferred_len + len + 128;
1540 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1541 ssh->deferred_size);
1543 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1544 ssh->deferred_len += len;
1548 * Send the whole deferred data block constructed by
1549 * ssh2_pkt_defer() or SSH1's defer_packet().
1551 static void ssh_pkt_defersend(Ssh ssh)
1554 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1555 ssh->deferred_len = ssh->deferred_size = 0;
1556 sfree(ssh->deferred_send_data);
1557 ssh->deferred_send_data = NULL;
1558 if (backlog > SSH_MAX_BACKLOG)
1559 ssh_throttle_all(ssh, 1, backlog);
1563 void bndebug(char *string, Bignum b)
1567 p = ssh2_mpint_fmt(b, &len);
1568 debug(("%s", string));
1569 for (i = 0; i < len; i++)
1570 debug((" %02x", p[i]));
1576 static void sha_mpint(SHA_State * s, Bignum b)
1580 p = ssh2_mpint_fmt(b, &len);
1581 sha_string(s, p, len);
1586 * SSH2 packet decode functions.
1588 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1590 unsigned long value;
1591 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1592 return 0; /* arrgh, no way to decline (FIXME?) */
1593 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1594 ssh->pktin.savedpos += 4;
1597 static int ssh2_pkt_getbool(Ssh ssh)
1599 unsigned long value;
1600 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1601 return 0; /* arrgh, no way to decline (FIXME?) */
1602 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1603 ssh->pktin.savedpos++;
1606 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1610 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1612 *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1613 ssh->pktin.savedpos += 4;
1614 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1616 *p = ssh->pktin.data + ssh->pktin.savedpos;
1617 ssh->pktin.savedpos += *length;
1619 static Bignum ssh2_pkt_getmp(Ssh ssh)
1625 ssh2_pkt_getstring(ssh, &p, &length);
1629 bombout(("internal error: Can't handle negative mpints"));
1632 b = bignum_from_bytes(p, length);
1637 * Helper function to add an SSH2 signature blob to a packet.
1638 * Expects to be shown the public key blob as well as the signature
1639 * blob. Normally works just like ssh2_pkt_addstring, but will
1640 * fiddle with the signature packet if necessary for
1641 * BUG_SSH2_RSA_PADDING.
1643 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1644 void *sigblob_v, int sigblob_len)
1646 unsigned char *pkblob = (unsigned char *)pkblob_v;
1647 unsigned char *sigblob = (unsigned char *)sigblob_v;
1649 /* dmemdump(pkblob, pkblob_len); */
1650 /* dmemdump(sigblob, sigblob_len); */
1653 * See if this is in fact an ssh-rsa signature and a buggy
1654 * server; otherwise we can just do this the easy way.
1656 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1657 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1658 int pos, len, siglen;
1661 * Find the byte length of the modulus.
1664 pos = 4+7; /* skip over "ssh-rsa" */
1665 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1666 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1667 pos += 4; /* find modulus itself */
1668 while (len > 0 && pkblob[pos] == 0)
1670 /* debug(("modulus length is %d\n", len)); */
1673 * Now find the signature integer.
1675 pos = 4+7; /* skip over "ssh-rsa" */
1676 siglen = GET_32BIT(sigblob+pos);
1677 /* debug(("signature length is %d\n", siglen)); */
1679 if (len != siglen) {
1680 unsigned char newlen[4];
1681 ssh2_pkt_addstring_start(ssh);
1682 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1683 /* dmemdump(sigblob, pos); */
1684 pos += 4; /* point to start of actual sig */
1685 PUT_32BIT(newlen, len);
1686 ssh2_pkt_addstring_data(ssh, newlen, 4);
1687 /* dmemdump(newlen, 4); */
1689 while (len-- > siglen) {
1690 ssh2_pkt_addstring_data(ssh, newlen, 1);
1691 /* dmemdump(newlen, 1); */
1693 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1694 /* dmemdump(sigblob+pos, siglen); */
1698 /* Otherwise fall through and do it the easy way. */
1701 ssh2_pkt_addstring_start(ssh);
1702 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1706 * Examine the remote side's version string and compare it against
1707 * a list of known buggy implementations.
1709 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1711 char *imp; /* pointer to implementation part */
1713 imp += strcspn(imp, "-");
1715 imp += strcspn(imp, "-");
1718 ssh->remote_bugs = 0;
1720 if (cfg.sshbug_ignore1 == BUG_ON ||
1721 (cfg.sshbug_ignore1 == BUG_AUTO &&
1722 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1723 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1724 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1726 * These versions don't support SSH1_MSG_IGNORE, so we have
1727 * to use a different defence against password length
1730 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1731 logevent("We believe remote version has SSH1 ignore bug");
1734 if (cfg.sshbug_plainpw1 == BUG_ON ||
1735 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1736 (!strcmp(imp, "Cisco-1.25")))) {
1738 * These versions need a plain password sent; they can't
1739 * handle having a null and a random length of data after
1742 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1743 logevent("We believe remote version needs a plain SSH1 password");
1746 if (cfg.sshbug_rsa1 == BUG_ON ||
1747 (cfg.sshbug_rsa1 == BUG_AUTO &&
1748 (!strcmp(imp, "Cisco-1.25")))) {
1750 * These versions apparently have no clue whatever about
1751 * RSA authentication and will panic and die if they see
1752 * an AUTH_RSA message.
1754 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1755 logevent("We believe remote version can't handle RSA authentication");
1758 if (cfg.sshbug_hmac2 == BUG_ON ||
1759 (cfg.sshbug_hmac2 == BUG_AUTO &&
1760 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1761 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1762 !strncmp(imp, "2.1 ", 4)))) {
1764 * These versions have the HMAC bug.
1766 ssh->remote_bugs |= BUG_SSH2_HMAC;
1767 logevent("We believe remote version has SSH2 HMAC bug");
1770 if (cfg.sshbug_derivekey2 == BUG_ON ||
1771 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1772 (!strncmp(imp, "2.0.", 4)))) {
1774 * These versions have the key-derivation bug (failing to
1775 * include the literal shared secret in the hashes that
1776 * generate the keys).
1778 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1779 logevent("We believe remote version has SSH2 key-derivation bug");
1782 if (cfg.sshbug_rsapad2 == BUG_ON ||
1783 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1784 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1785 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1787 * These versions have the SSH2 RSA padding bug.
1789 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1790 logevent("We believe remote version has SSH2 RSA padding bug");
1793 if (cfg.sshbug_dhgex2 == BUG_ON) {
1795 * These versions have the SSH2 DH GEX bug.
1797 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1798 logevent("We believe remote version has SSH2 DH group exchange bug");
1802 static int do_ssh_init(Ssh ssh, unsigned char c)
1804 struct do_ssh_init_state {
1812 crState(do_ssh_init_state);
1814 crBegin(ssh->do_ssh_init_crstate);
1816 /* Search for the string "SSH-" in the input. */
1819 static const int transS[] = { 1, 2, 2, 1 };
1820 static const int transH[] = { 0, 0, 3, 0 };
1821 static const int transminus[] = { 0, 0, 0, -1 };
1823 s->i = transS[s->i];
1825 s->i = transH[s->i];
1827 s->i = transminus[s->i];
1832 crReturn(1); /* get another character */
1836 s->vstring = smalloc(s->vstrsize);
1837 strcpy(s->vstring, "SSH-");
1841 crReturn(1); /* get another char */
1842 if (s->vslen >= s->vstrsize - 1) {
1844 s->vstring = srealloc(s->vstring, s->vstrsize);
1846 s->vstring[s->vslen++] = c;
1849 s->version[s->i] = '\0';
1851 } else if (s->i < sizeof(s->version) - 1)
1852 s->version[s->i++] = c;
1853 } else if (c == '\n')
1857 ssh->agentfwd_enabled = FALSE;
1858 ssh->rdpkt2_state.incoming_sequence = 0;
1860 s->vstring[s->vslen] = 0;
1861 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1864 vlog = smalloc(20 + s->vslen);
1865 sprintf(vlog, "Server version: %s", s->vstring);
1869 ssh_detect_bugs(ssh, s->vstring);
1872 * Decide which SSH protocol version to support.
1875 /* Anything strictly below "2.0" means protocol 1 is supported. */
1876 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1877 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1878 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1880 if (cfg.sshprot == 0 && !s->proto1) {
1881 bombout(("SSH protocol version 1 required by user but not provided by server"));
1884 if (cfg.sshprot == 3 && !s->proto2) {
1885 bombout(("SSH protocol version 2 required by user but not provided by server"));
1889 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1893 char verstring[80], vlog[100];
1894 sprintf(verstring, "SSH-2.0-%s", sshver);
1895 SHA_Init(&ssh->exhashbase);
1897 * Hash our version string and their version string.
1899 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1900 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1901 sprintf(vlog, "We claim version: %s", verstring);
1903 strcat(verstring, "\n");
1904 logevent("Using SSH protocol version 2");
1905 sk_write(ssh->s, verstring, strlen(verstring));
1906 ssh->protocol = ssh2_protocol;
1908 ssh->s_rdpkt = ssh2_rdpkt;
1913 char verstring[80], vlog[100];
1914 sprintf(verstring, "SSH-%s-%s",
1915 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1917 sprintf(vlog, "We claim version: %s", verstring);
1919 strcat(verstring, "\n");
1921 logevent("Using SSH protocol version 1");
1922 sk_write(ssh->s, verstring, strlen(verstring));
1923 ssh->protocol = ssh1_protocol;
1925 ssh->s_rdpkt = ssh1_rdpkt;
1927 ssh->state = SSH_STATE_BEFORE_SIZE;
1934 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1936 crBegin(ssh->ssh_gotdata_crstate);
1939 * To begin with, feed the characters one by one to the
1940 * protocol initialisation / selection function do_ssh_init().
1941 * When that returns 0, we're done with the initial greeting
1942 * exchange and can move on to packet discipline.
1945 int ret; /* need not be kept across crReturn */
1947 crReturnV; /* more data please */
1948 ret = do_ssh_init(ssh, *data);
1956 * We emerge from that loop when the initial negotiation is
1957 * over and we have selected an s_rdpkt function. Now pass
1958 * everything to s_rdpkt, and then pass the resulting packets
1959 * to the proper protocol handler.
1964 while (datalen > 0) {
1965 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1966 if (ssh->state == SSH_STATE_CLOSED) {
1969 ssh->protocol(ssh, NULL, 0, 1);
1970 if (ssh->state == SSH_STATE_CLOSED) {
1980 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1983 Ssh ssh = (Ssh) plug;
1984 ssh->state = SSH_STATE_CLOSED;
1990 /* A socket error has occurred. */
1991 logevent(error_msg);
1992 connection_fatal(error_msg);
1994 /* Otherwise, the remote side closed the connection normally. */
1999 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2001 Ssh ssh = (Ssh) plug;
2002 ssh_gotdata(ssh, data, len);
2003 if (ssh->state == SSH_STATE_CLOSED) {
2013 static void ssh_sent(Plug plug, int bufsize)
2015 Ssh ssh = (Ssh) plug;
2017 * If the send backlog on the SSH socket itself clears, we
2018 * should unthrottle the whole world if it was throttled.
2020 if (bufsize < SSH_MAX_BACKLOG)
2021 ssh_throttle_all(ssh, 0, bufsize);
2025 * Connect to specified host and port.
2026 * Returns an error message, or NULL on success.
2027 * Also places the canonical host name into `realhost'. It must be
2028 * freed by the caller.
2030 static char *connect_to_host(Ssh ssh, char *host, int port,
2031 char **realhost, int nodelay)
2033 static const struct plug_function_table fn_table = {
2043 ssh->savedhost = smalloc(1 + strlen(host));
2044 if (!ssh->savedhost)
2045 fatalbox("Out of memory");
2046 strcpy(ssh->savedhost, host);
2049 port = 22; /* default ssh port */
2050 ssh->savedport = port;
2057 sprintf(buf, "Looking up host \"%.170s\"", host);
2060 addr = sk_namelookup(host, realhost);
2061 if ((err = sk_addr_error(addr)))
2068 char buf[200], addrbuf[100];
2069 sk_getaddr(addr, addrbuf, 100);
2070 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2073 ssh->fn = &fn_table;
2074 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2075 if ((err = sk_socket_error(ssh->s))) {
2084 * Throttle or unthrottle the SSH connection.
2086 static void ssh1_throttle(Ssh ssh, int adjust)
2088 int old_count = ssh->v1_throttle_count;
2089 ssh->v1_throttle_count += adjust;
2090 assert(ssh->v1_throttle_count >= 0);
2091 if (ssh->v1_throttle_count && !old_count) {
2092 sk_set_frozen(ssh->s, 1);
2093 } else if (!ssh->v1_throttle_count && old_count) {
2094 sk_set_frozen(ssh->s, 0);
2099 * Throttle or unthrottle _all_ local data streams (for when sends
2100 * on the SSH connection itself back up).
2102 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2105 struct ssh_channel *c;
2107 if (enable == ssh->throttled_all)
2109 ssh->throttled_all = enable;
2110 ssh->overall_bufsize = bufsize;
2113 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2115 case CHAN_MAINSESSION:
2117 * This is treated separately, outside the switch.
2121 x11_override_throttle(c->u.x11.s, enable);
2124 /* Agent channels require no buffer management. */
2127 pfd_override_throttle(c->u.x11.s, enable);
2134 * Username and password input, abstracted off into routines
2135 * reusable in several places - even between SSH1 and SSH2.
2138 /* Set up a username or password input loop on a given buffer. */
2139 void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2141 ssh->userpass_input_buffer = buffer;
2142 ssh->userpass_input_buflen = buflen;
2143 ssh->userpass_input_bufpos = 0;
2144 ssh->userpass_input_echo = echo;
2148 * Process some terminal data in the course of username/password
2149 * input. Returns >0 for success (line of input returned in
2150 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2151 * for inconclusive (keep waiting for more input please).
2153 int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2158 switch (c = *in++) {
2161 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2162 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2167 if (ssh->userpass_input_bufpos > 0) {
2168 if (ssh->userpass_input_echo)
2169 c_write_str(ssh, "\b \b");
2170 ssh->userpass_input_bufpos--;
2175 while (ssh->userpass_input_bufpos > 0) {
2176 if (ssh->userpass_input_echo)
2177 c_write_str(ssh, "\b \b");
2178 ssh->userpass_input_bufpos--;
2186 if (((c >= ' ' && c <= '~') ||
2187 ((unsigned char) c >= 160))
2188 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2189 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2190 if (ssh->userpass_input_echo)
2191 c_write(ssh, &c, 1);
2200 * Handle the key exchange and user authentication phases.
2202 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2205 unsigned char cookie[8];
2206 struct RSAKey servkey, hostkey;
2207 struct MD5Context md5c;
2208 struct do_ssh1_login_state {
2210 unsigned char *rsabuf, *keystr1, *keystr2;
2211 unsigned long supported_ciphers_mask, supported_auths_mask;
2212 int tried_publickey, tried_agent;
2213 int tis_auth_refused, ccard_auth_refused;
2214 unsigned char session_id[16];
2217 void *publickey_blob;
2218 int publickey_bloblen;
2224 unsigned char request[5], *response, *p;
2233 crState(do_ssh1_login_state);
2235 crBegin(ssh->do_ssh1_login_crstate);
2240 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2241 bombout(("Public key packet not received"));
2245 logevent("Received public keys");
2247 memcpy(cookie, ssh->pktin.body, 8);
2249 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2250 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2253 * Log the host key fingerprint.
2257 logevent("Host key fingerprint is:");
2258 strcpy(logmsg, " ");
2259 hostkey.comment = NULL;
2260 rsa_fingerprint(logmsg + strlen(logmsg),
2261 sizeof(logmsg) - strlen(logmsg), &hostkey);
2265 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2266 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2267 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2269 ssh->v1_local_protoflags =
2270 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2271 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2274 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2275 MD5Update(&md5c, s->keystr1, servkey.bytes);
2276 MD5Update(&md5c, ssh->pktin.body, 8);
2277 MD5Final(s->session_id, &md5c);
2279 for (i = 0; i < 32; i++)
2280 ssh->session_key[i] = random_byte();
2282 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2284 s->rsabuf = smalloc(s->len);
2286 fatalbox("Out of memory");
2289 * Verify the host key.
2293 * First format the key into a string.
2295 int len = rsastr_len(&hostkey);
2296 char fingerprint[100];
2297 char *keystr = smalloc(len);
2299 fatalbox("Out of memory");
2300 rsastr_fmt(keystr, &hostkey);
2301 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2302 verify_ssh_host_key(ssh->savedhost, ssh->savedport, "rsa", keystr,
2307 for (i = 0; i < 32; i++) {
2308 s->rsabuf[i] = ssh->session_key[i];
2310 s->rsabuf[i] ^= s->session_id[i];
2313 if (hostkey.bytes > servkey.bytes) {
2314 rsaencrypt(s->rsabuf, 32, &servkey);
2315 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2317 rsaencrypt(s->rsabuf, 32, &hostkey);
2318 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2321 logevent("Encrypted session key");
2324 int cipher_chosen = 0, warn = 0;
2325 char *cipher_string = NULL;
2327 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2328 int next_cipher = cfg.ssh_cipherlist[i];
2329 if (next_cipher == CIPHER_WARN) {
2330 /* If/when we choose a cipher, warn about it */
2332 } else if (next_cipher == CIPHER_AES) {
2333 /* XXX Probably don't need to mention this. */
2334 logevent("AES not supported in SSH1, skipping");
2336 switch (next_cipher) {
2337 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2338 cipher_string = "3DES"; break;
2339 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2340 cipher_string = "Blowfish"; break;
2341 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2342 cipher_string = "single-DES"; break;
2344 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2348 if (!cipher_chosen) {
2349 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2350 bombout(("Server violates SSH 1 protocol by not "
2351 "supporting 3DES encryption"));
2353 /* shouldn't happen */
2354 bombout(("No supported ciphers found"));
2358 /* Warn about chosen cipher if necessary. */
2360 askcipher(cipher_string, 0);
2363 switch (s->cipher_type) {
2364 case SSH_CIPHER_3DES:
2365 logevent("Using 3DES encryption");
2367 case SSH_CIPHER_DES:
2368 logevent("Using single-DES encryption");
2370 case SSH_CIPHER_BLOWFISH:
2371 logevent("Using Blowfish encryption");
2375 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2376 PKT_CHAR, s->cipher_type,
2377 PKT_DATA, cookie, 8,
2378 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2379 PKT_DATA, s->rsabuf, s->len,
2380 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2382 logevent("Trying to enable encryption...");
2386 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2387 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2389 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2390 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2393 sprintf(buf, "Initialised %.200s encryption", ssh->cipher->text_name);
2397 ssh->crcda_ctx = crcda_make_context();
2398 logevent("Installing CRC compensation attack detector");
2402 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2403 bombout(("Encryption not successfully enabled"));
2407 logevent("Successfully started encryption");
2411 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2412 if (ssh_get_line && !ssh_getline_pw_only) {
2413 if (!ssh_get_line("login as: ",
2414 s->username, sizeof(s->username), FALSE)) {
2416 * get_line failed to get a username.
2419 logevent("No username provided. Abandoning session.");
2420 ssh->state = SSH_STATE_CLOSED;
2424 int ret; /* need not be kept over crReturn */
2425 c_write_str(ssh, "login as: ");
2428 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2430 crWaitUntil(!ispkt);
2431 ret = process_userpass_input(ssh, in, inlen);
2435 c_write_str(ssh, "\r\n");
2438 strncpy(s->username, cfg.username, sizeof(s->username));
2439 s->username[sizeof(s->username)-1] = '\0';
2442 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2444 char userlog[22 + sizeof(s->username)];
2445 sprintf(userlog, "Sent username \"%s\"", s->username);
2447 if (flags & FLAG_INTERACTIVE &&
2448 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2449 strcat(userlog, "\r\n");
2450 c_write_str(ssh, userlog);
2457 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2458 /* We must not attempt PK auth. Pretend we've already tried it. */
2459 s->tried_publickey = s->tried_agent = 1;
2461 s->tried_publickey = s->tried_agent = 0;
2463 s->tis_auth_refused = s->ccard_auth_refused = 0;
2464 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2466 if (!rsakey_pubblob(cfg.keyfile,
2467 &s->publickey_blob, &s->publickey_bloblen))
2468 s->publickey_blob = NULL;
2470 s->publickey_blob = NULL;
2472 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2473 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2475 if (agent_exists() && !s->tried_agent) {
2477 * Attempt RSA authentication using Pageant.
2483 logevent("Pageant is running. Requesting keys.");
2485 /* Request the keys held by the agent. */
2486 PUT_32BIT(s->request, 1);
2487 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2488 agent_query(s->request, 5, &r, &s->responselen);
2489 s->response = (unsigned char *) r;
2490 if (s->response && s->responselen >= 5 &&
2491 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2492 s->p = s->response + 5;
2493 s->nkeys = GET_32BIT(s->p);
2497 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2500 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2503 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2506 if (s->publickey_blob &&
2507 !memcmp(s->p, s->publickey_blob,
2508 s->publickey_bloblen)) {
2509 logevent("This key matches configured key file");
2510 s->tried_publickey = 1;
2513 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2514 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2515 s->commentlen = GET_32BIT(s->p);
2518 s->p += s->commentlen;
2519 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2520 PKT_BIGNUM, s->key.modulus, PKT_END);
2522 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2523 logevent("Key refused");
2526 logevent("Received RSA challenge");
2527 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2529 char *agentreq, *q, *ret;
2532 len = 1 + 4; /* message type, bit count */
2533 len += ssh1_bignum_length(s->key.exponent);
2534 len += ssh1_bignum_length(s->key.modulus);
2535 len += ssh1_bignum_length(s->challenge);
2536 len += 16; /* session id */
2537 len += 4; /* response format */
2538 agentreq = smalloc(4 + len);
2539 PUT_32BIT(agentreq, len);
2541 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2542 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2544 q += ssh1_write_bignum(q, s->key.exponent);
2545 q += ssh1_write_bignum(q, s->key.modulus);
2546 q += ssh1_write_bignum(q, s->challenge);
2547 memcpy(q, s->session_id, 16);
2549 PUT_32BIT(q, 1); /* response format */
2550 agent_query(agentreq, len + 4, &vret, &retlen);
2554 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2555 logevent("Sending Pageant's response");
2556 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2557 PKT_DATA, ret + 5, 16,
2561 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2563 ("Pageant's response accepted");
2564 if (flags & FLAG_VERBOSE) {
2565 c_write_str(ssh, "Authenticated using"
2567 c_write(ssh, s->commentp,
2569 c_write_str(ssh, "\" from agent\r\n");
2574 ("Pageant's response not accepted");
2577 ("Pageant failed to answer challenge");
2581 logevent("No reply received from Pageant");
2584 freebn(s->key.exponent);
2585 freebn(s->key.modulus);
2586 freebn(s->challenge);
2594 if (*cfg.keyfile && !s->tried_publickey)
2595 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2597 if (cfg.try_tis_auth &&
2598 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2599 !s->tis_auth_refused) {
2600 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2601 logevent("Requested TIS authentication");
2602 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2604 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2605 logevent("TIS authentication declined");
2606 if (flags & FLAG_INTERACTIVE)
2607 c_write_str(ssh, "TIS authentication refused.\r\n");
2608 s->tis_auth_refused = 1;
2611 int challengelen = GET_32BIT(ssh->pktin.body);
2612 logevent("Received TIS challenge");
2613 if (challengelen > sizeof(s->prompt) - 1)
2614 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2615 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2616 /* Prompt heuristic comes from OpenSSH */
2617 strncpy(s->prompt + challengelen,
2618 memchr(s->prompt, '\n', challengelen) ?
2619 "": "\r\nResponse: ",
2620 (sizeof s->prompt) - challengelen);
2621 s->prompt[(sizeof s->prompt) - 1] = '\0';
2624 if (cfg.try_tis_auth &&
2625 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2626 !s->ccard_auth_refused) {
2627 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2628 logevent("Requested CryptoCard authentication");
2629 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2631 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2632 logevent("CryptoCard authentication declined");
2633 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2634 s->ccard_auth_refused = 1;
2637 int challengelen = GET_32BIT(ssh->pktin.body);
2638 logevent("Received CryptoCard challenge");
2639 if (challengelen > sizeof(s->prompt) - 1)
2640 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2641 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2642 strncpy(s->prompt + challengelen,
2643 memchr(s->prompt, '\n', challengelen) ?
2644 "" : "\r\nResponse: ",
2645 sizeof(s->prompt) - challengelen);
2646 s->prompt[sizeof(s->prompt) - 1] = '\0';
2649 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2650 sprintf(s->prompt, "%.90s@%.90s's password: ",
2651 s->username, ssh->savedhost);
2653 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2654 char *comment = NULL;
2657 if (flags & FLAG_VERBOSE)
2658 c_write_str(ssh, "Trying public key authentication.\r\n");
2659 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2661 type = key_type(cfg.keyfile);
2662 if (type != SSH_KEYTYPE_SSH1) {
2663 sprintf(msgbuf, "Key is of wrong type (%s)",
2664 key_type_to_str(type));
2666 c_write_str(ssh, msgbuf);
2667 c_write_str(ssh, "\r\n");
2668 s->tried_publickey = 1;
2671 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2672 if (flags & FLAG_VERBOSE)
2673 c_write_str(ssh, "No passphrase required.\r\n");
2676 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2681 * Show password prompt, having first obtained it via a TIS
2682 * or CryptoCard exchange if we're doing TIS or CryptoCard
2686 if (!ssh_get_line(s->prompt, s->password,
2687 sizeof(s->password), TRUE)) {
2689 * get_line failed to get a password (for example
2690 * because one was supplied on the command line
2691 * which has already failed to work). Terminate.
2693 send_packet(ssh, SSH1_MSG_DISCONNECT,
2694 PKT_STR, "No more passwords available to try",
2696 logevent("Unable to authenticate");
2697 connection_fatal("Unable to authenticate");
2698 ssh->state = SSH_STATE_CLOSED;
2702 /* Prompt may have come from server. We've munged it a bit, so
2703 * we know it to be zero-terminated at least once. */
2704 int ret; /* need not be saved over crReturn */
2705 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2708 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2710 crWaitUntil(!ispkt);
2711 ret = process_userpass_input(ssh, in, inlen);
2715 c_write_str(ssh, "\r\n");
2719 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2721 * Try public key authentication with the specified
2724 s->tried_publickey = 1;
2727 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2729 c_write_str(ssh, "Couldn't load private key from ");
2730 c_write_str(ssh, cfg.keyfile);
2731 c_write_str(ssh, ".\r\n");
2732 continue; /* go and try password */
2735 c_write_str(ssh, "Wrong passphrase.\r\n");
2736 s->tried_publickey = 0;
2737 continue; /* try again */
2742 * Send a public key attempt.
2744 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2745 PKT_BIGNUM, s->key.modulus, PKT_END);
2748 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2749 c_write_str(ssh, "Server refused our public key.\r\n");
2750 continue; /* go and try password */
2752 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2753 bombout(("Bizarre response to offer of public key"));
2759 unsigned char buffer[32];
2760 Bignum challenge, response;
2762 ssh1_read_bignum(ssh->pktin.body, &challenge);
2763 response = rsadecrypt(challenge, &s->key);
2764 freebn(s->key.private_exponent);/* burn the evidence */
2766 for (i = 0; i < 32; i++) {
2767 buffer[i] = bignum_byte(response, 31 - i);
2771 MD5Update(&md5c, buffer, 32);
2772 MD5Update(&md5c, s->session_id, 16);
2773 MD5Final(buffer, &md5c);
2775 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2776 PKT_DATA, buffer, 16, PKT_END);
2783 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2784 if (flags & FLAG_VERBOSE)
2785 c_write_str(ssh, "Failed to authenticate with"
2786 " our public key.\r\n");
2787 continue; /* go and try password */
2788 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2789 bombout(("Bizarre response to RSA authentication response"));
2793 break; /* we're through! */
2795 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2797 * Defence against traffic analysis: we send a
2798 * whole bunch of packets containing strings of
2799 * different lengths. One of these strings is the
2800 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2801 * The others are all random data in
2802 * SSH1_MSG_IGNORE packets. This way a passive
2803 * listener can't tell which is the password, and
2804 * hence can't deduce the password length.
2806 * Anybody with a password length greater than 16
2807 * bytes is going to have enough entropy in their
2808 * password that a listener won't find it _that_
2809 * much help to know how long it is. So what we'll
2812 * - if password length < 16, we send 15 packets
2813 * containing string lengths 1 through 15
2815 * - otherwise, we let N be the nearest multiple
2816 * of 8 below the password length, and send 8
2817 * packets containing string lengths N through
2818 * N+7. This won't obscure the order of
2819 * magnitude of the password length, but it will
2820 * introduce a bit of extra uncertainty.
2822 * A few servers (the old 1.2.18 through 1.2.22)
2823 * can't deal with SSH1_MSG_IGNORE. For these
2824 * servers, we need an alternative defence. We make
2825 * use of the fact that the password is interpreted
2826 * as a C string: so we can append a NUL, then some
2829 * One server (a Cisco one) can deal with neither
2830 * SSH1_MSG_IGNORE _nor_ a padded password string.
2831 * For this server we are left with no defences
2832 * against password length sniffing.
2834 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2836 * The server can deal with SSH1_MSG_IGNORE, so
2837 * we can use the primary defence.
2839 int bottom, top, pwlen, i;
2842 pwlen = strlen(s->password);
2844 bottom = 0; /* zero length passwords are OK! :-) */
2847 bottom = pwlen & ~7;
2851 assert(pwlen >= bottom && pwlen <= top);
2853 randomstr = smalloc(top + 1);
2855 for (i = bottom; i <= top; i++) {
2857 defer_packet(ssh, s->pwpkt_type,
2858 PKT_STR, s->password, PKT_END);
2860 for (j = 0; j < i; j++) {
2862 randomstr[j] = random_byte();
2863 } while (randomstr[j] == '\0');
2865 randomstr[i] = '\0';
2866 defer_packet(ssh, SSH1_MSG_IGNORE,
2867 PKT_STR, randomstr, PKT_END);
2870 logevent("Sending password with camouflage packets");
2871 ssh_pkt_defersend(ssh);
2873 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2875 * The server can't deal with SSH1_MSG_IGNORE
2876 * but can deal with padded passwords, so we
2877 * can use the secondary defence.
2883 len = strlen(s->password);
2884 if (len < sizeof(string)) {
2886 strcpy(string, s->password);
2887 len++; /* cover the zero byte */
2888 while (len < sizeof(string)) {
2889 string[len++] = (char) random_byte();
2894 logevent("Sending length-padded password");
2895 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2896 PKT_DATA, ss, len, PKT_END);
2899 * The server has _both_
2900 * BUG_CHOKES_ON_SSH1_IGNORE and
2901 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2902 * therefore nothing we can do.
2905 len = strlen(s->password);
2906 logevent("Sending unpadded password");
2907 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2908 PKT_DATA, s->password, len, PKT_END);
2911 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2914 logevent("Sent password");
2915 memset(s->password, 0, strlen(s->password));
2917 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2918 if (flags & FLAG_VERBOSE)
2919 c_write_str(ssh, "Access denied\r\n");
2920 logevent("Authentication refused");
2921 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2922 bombout(("Strange packet received, type %d", ssh->pktin.type));
2927 logevent("Authentication successful");
2932 void sshfwd_close(struct ssh_channel *c)
2936 if (c && !c->closes) {
2938 * If the channel's remoteid is -1, we have sent
2939 * CHANNEL_OPEN for this channel, but it hasn't even been
2940 * acknowledged by the server. So we must set a close flag
2941 * on it now, and then when the server acks the channel
2942 * open, we can close it then.
2944 if (((int)c->remoteid) != -1) {
2945 if (ssh->version == 1) {
2946 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2949 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2950 ssh2_pkt_adduint32(ssh, c->remoteid);
2954 c->closes = 1; /* sent MSG_CLOSE */
2955 if (c->type == CHAN_X11) {
2957 logevent("Forwarded X11 connection terminated");
2958 } else if (c->type == CHAN_SOCKDATA ||
2959 c->type == CHAN_SOCKDATA_DORMANT) {
2961 logevent("Forwarded port closed");
2966 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2970 if (ssh->version == 1) {
2971 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2972 PKT_INT, c->remoteid,
2973 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2975 * In SSH1 we can return 0 here - implying that forwarded
2976 * connections are never individually throttled - because
2977 * the only circumstance that can cause throttling will be
2978 * the whole SSH connection backing up, in which case
2979 * _everything_ will be throttled as a whole.
2983 ssh2_add_channel_data(c, buf, len);
2984 return ssh2_try_send(c);
2988 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2992 if (ssh->version == 1) {
2993 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2994 c->v.v1.throttling = 0;
2995 ssh1_throttle(ssh, -1);
2998 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3002 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3004 crBegin(ssh->ssh1_protocol_crstate);
3008 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3011 if (ssh->state == SSH_STATE_CLOSED)
3014 if (cfg.agentfwd && agent_exists()) {
3015 logevent("Requesting agent forwarding");
3016 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3020 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3021 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3022 bombout(("Protocol confusion"));
3024 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3025 logevent("Agent forwarding refused");
3027 logevent("Agent forwarding enabled");
3028 ssh->agentfwd_enabled = TRUE;
3032 if (cfg.x11_forward) {
3033 char proto[20], data[64];
3034 logevent("Requesting X11 forwarding");
3035 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3036 data, sizeof(data));
3037 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3038 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3039 PKT_STR, proto, PKT_STR, data,
3040 PKT_INT, 0, PKT_END);
3042 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3043 PKT_STR, proto, PKT_STR, data, PKT_END);
3048 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3049 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3050 bombout(("Protocol confusion"));
3052 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3053 logevent("X11 forwarding refused");
3055 logevent("X11 forwarding enabled");
3056 ssh->X11_fwd_enabled = TRUE;
3063 int sport,dport,sserv,dserv;
3064 char sports[256], dports[256], host[256];
3068 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3069 /* Add port forwardings. */
3070 ssh->portfwd_strptr = cfg.portfwd;
3071 while (*ssh->portfwd_strptr) {
3072 type = *ssh->portfwd_strptr++;
3074 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3075 sports[n++] = *ssh->portfwd_strptr++;
3077 if (*ssh->portfwd_strptr == '\t')
3078 ssh->portfwd_strptr++;
3080 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3081 host[n++] = *ssh->portfwd_strptr++;
3083 if (*ssh->portfwd_strptr == ':')
3084 ssh->portfwd_strptr++;
3086 while (*ssh->portfwd_strptr)
3087 dports[n++] = *ssh->portfwd_strptr++;
3089 ssh->portfwd_strptr++;
3090 dport = atoi(dports);
3094 se = getservbyname(dports, NULL);
3096 dport = ntohs(se->s_port);
3099 "Service lookup failed for destination port \"%s\"",
3104 sport = atoi(sports);
3108 se = getservbyname(sports, NULL);
3110 sport = ntohs(se->s_port);
3113 "Service lookup failed for source port \"%s\"",
3118 if (sport && dport) {
3120 pfd_addforward(host, dport, sport, ssh);
3121 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3122 " %s:%.*s%.*s%d%.*s",
3123 sserv ? strlen(sports) : 0, sports,
3124 sserv, "(", sport, sserv, ")",
3126 dserv ? strlen(dports) : 0, dports,
3127 dserv, "(", dport, dserv, ")");
3130 struct ssh_rportfwd *pf;
3131 pf = smalloc(sizeof(*pf));
3132 strcpy(pf->dhost, host);
3134 if (add234(ssh->rportfwds, pf) != pf) {
3136 "Duplicate remote port forwarding to %s:%d",
3141 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3142 " forward to %s:%.*s%.*s%d%.*s",
3143 sserv ? strlen(sports) : 0, sports,
3144 sserv, "(", sport, sserv, ")",
3146 dserv ? strlen(dports) : 0, dports,
3147 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(("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(("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(("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 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 = ssh->pktin.body+8; hostsize != 0; hostsize--) {
3337 if (h+1 < host+sizeof(host))
3342 port = GET_32BIT(p);
3344 strcpy(pf.dhost, host);
3347 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3348 sprintf(buf, "Rejected remote port open request for %s:%d",
3351 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3352 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3354 sprintf(buf, "Received remote port open request for %s:%d",
3357 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3360 sprintf(buf, "Port open failed: %s", e);
3363 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3364 PKT_INT, GET_32BIT(ssh->pktin.body),
3367 c->remoteid = GET_32BIT(ssh->pktin.body);
3368 c->localid = alloc_channel_id(ssh);
3370 c->v.v1.throttling = 0;
3371 c->type = CHAN_SOCKDATA; /* identify channel type */
3372 add234(ssh->channels, c);
3373 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3374 PKT_INT, c->remoteid, PKT_INT,
3375 c->localid, PKT_END);
3376 logevent("Forwarded port opened successfully");
3380 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3381 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3382 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3383 struct ssh_channel *c;
3385 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3386 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3387 c->remoteid = localid;
3388 c->type = CHAN_SOCKDATA;
3389 c->v.v1.throttling = 0;
3390 pfd_confirm(c->u.pfd.s);
3393 if (c && c->closes) {
3395 * We have a pending close on this channel,
3396 * which we decided on before the server acked
3397 * the channel open. So now we know the
3398 * remoteid, we can close it again.
3400 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3401 PKT_INT, c->remoteid, PKT_END);
3404 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3405 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3406 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
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(("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, p, len);
3472 bufsize = pfd_send(c->u.pfd.s, 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(("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)
3577 int needlen = strlen(needle);
3580 * Is it at the start of the string?
3582 if (haylen >= needlen && /* haystack is long enough */
3583 !memcmp(needle, haystack, needlen) && /* initial match */
3584 (haylen == needlen || haystack[needlen] == ',')
3585 /* either , or EOS follows */
3589 * If not, search for the next comma and resume after that.
3590 * If no comma found, terminate.
3592 while (haylen > 0 && *haystack != ',')
3593 haylen--, haystack++;
3596 haylen--, haystack++; /* skip over comma itself */
3601 * SSH2 key creation method.
3603 static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
3607 /* First 20 bytes. */
3609 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3611 SHA_Bytes(&s, H, 20);
3612 SHA_Bytes(&s, &chr, 1);
3613 SHA_Bytes(&s, sessid, 20);
3614 SHA_Final(&s, keyspace);
3615 /* Next 20 bytes. */
3617 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3619 SHA_Bytes(&s, H, 20);
3620 SHA_Bytes(&s, keyspace, 20);
3621 SHA_Final(&s, keyspace + 20);
3625 * Handle the SSH2 transport layer.
3627 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3629 struct do_ssh2_transport_state {
3630 int nbits, pbits, warn;
3631 Bignum p, g, e, f, K;
3632 int kex_init_value, kex_reply_value;
3633 const struct ssh_mac **maclist;
3635 const struct ssh2_cipher *cscipher_tobe;
3636 const struct ssh2_cipher *sccipher_tobe;
3637 const struct ssh_mac *csmac_tobe;
3638 const struct ssh_mac *scmac_tobe;
3639 const struct ssh_compress *cscomp_tobe;
3640 const struct ssh_compress *sccomp_tobe;
3641 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3642 int hostkeylen, siglen;
3643 void *hkey; /* actual host key */
3644 unsigned char exchange_hash[20];
3645 int n_preferred_ciphers;
3646 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3647 const struct ssh_compress *preferred_comp;
3650 crState(do_ssh2_transport_state);
3652 crBegin(ssh->do_ssh2_transport_crstate);
3654 s->cscipher_tobe = s->sccipher_tobe = NULL;
3655 s->csmac_tobe = s->scmac_tobe = NULL;
3656 s->cscomp_tobe = s->sccomp_tobe = NULL;
3664 * Set up the preferred ciphers. (NULL => warn below here)
3666 s->n_preferred_ciphers = 0;
3667 for (i = 0; i < CIPHER_MAX; i++) {
3668 switch (cfg.ssh_cipherlist[i]) {
3669 case CIPHER_BLOWFISH:
3670 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3673 if (cfg.ssh2_des_cbc) {
3674 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3678 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3681 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3684 /* Flag for later. Don't bother if it's the last in
3686 if (i < CIPHER_MAX - 1) {
3687 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3695 * Set up preferred compression.
3697 if (cfg.compression)
3698 s->preferred_comp = &ssh_zlib;
3700 s->preferred_comp = &ssh_comp_none;
3703 * Be prepared to work around the buggy MAC problem.
3705 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3706 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3708 s->maclist = macs, s->nmacs = lenof(macs);
3712 int i, j, cipherstr_started;
3715 * Construct and send our key exchange packet.
3717 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3718 for (i = 0; i < 16; i++)
3719 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3720 /* List key exchange algorithms. */
3721 ssh2_pkt_addstring_start(ssh);
3722 for (i = 0; i < lenof(kex_algs); i++) {
3723 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3724 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3726 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3727 if (i < lenof(kex_algs) - 1)
3728 ssh2_pkt_addstring_str(ssh, ",");
3730 /* List server host key algorithms. */
3731 ssh2_pkt_addstring_start(ssh);
3732 for (i = 0; i < lenof(hostkey_algs); i++) {
3733 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3734 if (i < lenof(hostkey_algs) - 1)
3735 ssh2_pkt_addstring_str(ssh, ",");
3737 /* List client->server encryption algorithms. */
3738 ssh2_pkt_addstring_start(ssh);
3739 cipherstr_started = 0;
3740 for (i = 0; i < s->n_preferred_ciphers; i++) {
3741 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3742 if (!c) continue; /* warning flag */
3743 for (j = 0; j < c->nciphers; j++) {
3744 if (cipherstr_started)
3745 ssh2_pkt_addstring_str(ssh, ",");
3746 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3747 cipherstr_started = 1;
3750 /* List server->client encryption algorithms. */
3751 ssh2_pkt_addstring_start(ssh);
3752 cipherstr_started = 0;
3753 for (i = 0; i < s->n_preferred_ciphers; i++) {
3754 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3755 if (!c) continue; /* warning flag */
3756 for (j = 0; j < c->nciphers; j++) {
3757 if (cipherstr_started)
3758 ssh2_pkt_addstring_str(ssh, ",");
3759 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3760 cipherstr_started = 1;
3763 /* List client->server MAC algorithms. */
3764 ssh2_pkt_addstring_start(ssh);
3765 for (i = 0; i < s->nmacs; i++) {
3766 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3767 if (i < s->nmacs - 1)
3768 ssh2_pkt_addstring_str(ssh, ",");
3770 /* List server->client MAC algorithms. */
3771 ssh2_pkt_addstring_start(ssh);
3772 for (i = 0; i < s->nmacs; i++) {
3773 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3774 if (i < s->nmacs - 1)
3775 ssh2_pkt_addstring_str(ssh, ",");
3777 /* List client->server compression algorithms. */
3778 ssh2_pkt_addstring_start(ssh);
3779 for (i = 0; i < lenof(compressions) + 1; i++) {
3780 const struct ssh_compress *c =
3781 i == 0 ? s->preferred_comp : compressions[i - 1];
3782 ssh2_pkt_addstring_str(ssh, c->name);
3783 if (i < lenof(compressions))
3784 ssh2_pkt_addstring_str(ssh, ",");
3786 /* List server->client compression algorithms. */
3787 ssh2_pkt_addstring_start(ssh);
3788 for (i = 0; i < lenof(compressions) + 1; i++) {
3789 const struct ssh_compress *c =
3790 i == 0 ? s->preferred_comp : compressions[i - 1];
3791 ssh2_pkt_addstring_str(ssh, c->name);
3792 if (i < lenof(compressions))
3793 ssh2_pkt_addstring_str(ssh, ",");
3795 /* List client->server languages. Empty list. */
3796 ssh2_pkt_addstring_start(ssh);
3797 /* List server->client languages. Empty list. */
3798 ssh2_pkt_addstring_start(ssh);
3799 /* First KEX packet does _not_ follow, because we're not that brave. */
3800 ssh2_pkt_addbool(ssh, FALSE);
3802 ssh2_pkt_adduint32(ssh, 0);
3805 ssh->exhash = ssh->exhashbase;
3806 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3812 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3815 * Now examine the other side's KEXINIT to see what we're up
3822 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3823 bombout(("expected key exchange packet from server"));
3827 ssh->hostkey = NULL;
3828 s->cscipher_tobe = NULL;
3829 s->sccipher_tobe = NULL;
3830 s->csmac_tobe = NULL;
3831 s->scmac_tobe = NULL;
3832 s->cscomp_tobe = NULL;
3833 s->sccomp_tobe = NULL;
3834 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3835 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3836 for (i = 0; i < lenof(kex_algs); i++) {
3837 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3838 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3840 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3841 ssh->kex = kex_algs[i];
3845 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3846 for (i = 0; i < lenof(hostkey_algs); i++) {
3847 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3848 ssh->hostkey = hostkey_algs[i];
3852 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3854 for (i = 0; i < s->n_preferred_ciphers; i++) {
3855 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3859 for (j = 0; j < c->nciphers; j++) {
3860 if (in_commasep_string(c->list[j]->name, str, len)) {
3861 s->cscipher_tobe = c->list[j];
3866 if (s->cscipher_tobe) {
3868 askcipher(s->cscipher_tobe->name, 1);
3872 if (!s->cscipher_tobe) {
3873 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3877 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3879 for (i = 0; i < s->n_preferred_ciphers; i++) {
3880 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3884 for (j = 0; j < c->nciphers; j++) {
3885 if (in_commasep_string(c->list[j]->name, str, len)) {
3886 s->sccipher_tobe = c->list[j];
3891 if (s->sccipher_tobe) {
3893 askcipher(s->sccipher_tobe->name, 2);
3897 if (!s->sccipher_tobe) {
3898 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3902 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3903 for (i = 0; i < s->nmacs; i++) {
3904 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3905 s->csmac_tobe = s->maclist[i];
3909 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3910 for (i = 0; i < s->nmacs; i++) {
3911 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3912 s->scmac_tobe = s->maclist[i];
3916 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3917 for (i = 0; i < lenof(compressions) + 1; i++) {
3918 const struct ssh_compress *c =
3919 i == 0 ? s->preferred_comp : compressions[i - 1];
3920 if (in_commasep_string(c->name, str, len)) {
3925 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3926 for (i = 0; i < lenof(compressions) + 1; i++) {
3927 const struct ssh_compress *c =
3928 i == 0 ? s->preferred_comp : compressions[i - 1];
3929 if (in_commasep_string(c->name, str, len)) {
3937 * Work out the number of bits of key we will need from the key
3938 * exchange. We start with the maximum key length of either
3944 csbits = s->cscipher_tobe->keylen;
3945 scbits = s->sccipher_tobe->keylen;
3946 s->nbits = (csbits > scbits ? csbits : scbits);
3948 /* The keys only have 160-bit entropy, since they're based on
3949 * a SHA-1 hash. So cap the key size at 160 bits. */
3954 * If we're doing Diffie-Hellman group exchange, start by
3955 * requesting a group.
3957 if (ssh->kex == &ssh_diffiehellman_gex) {
3958 logevent("Doing Diffie-Hellman group exchange");
3959 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3961 * Work out how big a DH group we will need to allow that
3964 s->pbits = 512 << ((s->nbits - 1) / 64);
3965 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3966 ssh2_pkt_adduint32(ssh, s->pbits);
3970 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3971 bombout(("expected key exchange group packet from server"));
3974 s->p = ssh2_pkt_getmp(ssh);
3975 s->g = ssh2_pkt_getmp(ssh);
3976 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3977 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3978 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3980 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3981 ssh->kex_ctx = dh_setup_group1();
3982 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3983 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3986 logevent("Doing Diffie-Hellman key exchange");
3988 * Now generate and send e for Diffie-Hellman.
3990 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
3991 ssh2_pkt_init(ssh, s->kex_init_value);
3992 ssh2_pkt_addmp(ssh, s->e);
3996 if (ssh->pktin.type != s->kex_reply_value) {
3997 bombout(("expected key exchange reply packet from server"));
4000 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4001 s->f = ssh2_pkt_getmp(ssh);
4002 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4004 s->K = dh_find_K(ssh->kex_ctx, s->f);
4006 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4007 if (ssh->kex == &ssh_diffiehellman_gex) {
4008 sha_uint32(&ssh->exhash, s->pbits);
4009 sha_mpint(&ssh->exhash, s->p);
4010 sha_mpint(&ssh->exhash, s->g);
4012 sha_mpint(&ssh->exhash, s->e);
4013 sha_mpint(&ssh->exhash, s->f);
4014 sha_mpint(&ssh->exhash, s->K);
4015 SHA_Final(&ssh->exhash, s->exchange_hash);
4017 dh_cleanup(ssh->kex_ctx);
4020 debug(("Exchange hash is:\n"));
4021 dmemdump(s->exchange_hash, 20);
4024 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4026 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4027 s->exchange_hash, 20)) {
4028 bombout(("Server's host key did not match the signature supplied"));
4033 * Authenticate remote host: verify host key. (We've already
4034 * checked the signature of the exchange hash.)
4036 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4037 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4038 verify_ssh_host_key(ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4039 s->keystr, s->fingerprint);
4040 if (s->first_kex) { /* don't bother logging this in rekeys */
4041 logevent("Host key fingerprint is:");
4042 logevent(s->fingerprint);
4044 sfree(s->fingerprint);
4046 ssh->hostkey->freekey(s->hkey);
4049 * Send SSH2_MSG_NEWKEYS.
4051 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4055 * Expect SSH2_MSG_NEWKEYS from server.
4058 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4059 bombout(("expected new-keys packet from server"));
4064 * Create and initialise session keys.
4066 if (ssh->cs_cipher_ctx)
4067 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4068 ssh->cscipher = s->cscipher_tobe;
4069 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4071 if (ssh->sc_cipher_ctx)
4072 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4073 ssh->sccipher = s->sccipher_tobe;
4074 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4076 if (ssh->cs_mac_ctx)
4077 ssh->csmac->free_context(ssh->cs_mac_ctx);
4078 ssh->csmac = s->csmac_tobe;
4079 ssh->cs_mac_ctx = ssh->csmac->make_context();
4081 if (ssh->sc_mac_ctx)
4082 ssh->scmac->free_context(ssh->sc_mac_ctx);
4083 ssh->scmac = s->scmac_tobe;
4084 ssh->sc_mac_ctx = ssh->scmac->make_context();
4086 if (ssh->cs_comp_ctx)
4087 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4088 ssh->cscomp = s->cscomp_tobe;
4089 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4091 if (ssh->sc_comp_ctx)
4092 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4093 ssh->sccomp = s->sccomp_tobe;
4094 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4097 * Set IVs after keys. Here we use the exchange hash from the
4098 * _first_ key exchange.
4101 unsigned char keyspace[40];
4103 memcpy(ssh->v2_session_id, s->exchange_hash,
4104 sizeof(s->exchange_hash));
4105 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4106 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4107 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4108 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4109 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4110 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4111 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4112 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4113 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4114 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4115 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4116 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4120 sprintf(buf, "Initialised %.200s client->server encryption",
4121 ssh->cscipher->text_name);
4123 sprintf(buf, "Initialised %.200s server->client encryption",
4124 ssh->sccipher->text_name);
4126 if (ssh->cscomp->text_name) {
4127 sprintf(buf, "Initialised %.200s compression",
4128 ssh->cscomp->text_name);
4131 if (ssh->sccomp->text_name) {
4132 sprintf(buf, "Initialised %.200s decompression",
4133 ssh->sccomp->text_name);
4140 * If this is the first key exchange phase, we must pass the
4141 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4142 * wants to see it but because it will need time to initialise
4143 * itself before it sees an actual packet. In subsequent key
4144 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4145 * it would only confuse the layer above.
4147 if (!s->first_kex) {
4153 * Now we're encrypting. Begin returning 1 to the protocol main
4154 * function so that other things can run on top of the
4155 * transport. If we ever see a KEXINIT, we must go back to the
4158 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4161 logevent("Server initiated key re-exchange");
4162 goto begin_key_exchange;
4168 * Add data to an SSH2 channel output buffer.
4170 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4173 bufchain_add(&c->v.v2.outbuffer, buf, len);
4177 * Attempt to send data on an SSH2 channel.
4179 static int ssh2_try_send(struct ssh_channel *c)
4183 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4186 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4187 if ((unsigned)len > c->v.v2.remwindow)
4188 len = c->v.v2.remwindow;
4189 if ((unsigned)len > c->v.v2.remmaxpkt)
4190 len = c->v.v2.remmaxpkt;
4191 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4192 ssh2_pkt_adduint32(ssh, c->remoteid);
4193 ssh2_pkt_addstring_start(ssh);
4194 ssh2_pkt_addstring_data(ssh, data, len);
4196 bufchain_consume(&c->v.v2.outbuffer, len);
4197 c->v.v2.remwindow -= len;
4201 * After having sent as much data as we can, return the amount
4204 return bufchain_size(&c->v.v2.outbuffer);
4208 * Potentially enlarge the window on an SSH2 channel.
4210 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4215 * Never send WINDOW_ADJUST for a channel that the remote side
4216 * already thinks it's closed; there's no point, since it won't
4217 * be sending any more data anyway.
4222 if (newwin > c->v.v2.locwindow) {
4223 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4224 ssh2_pkt_adduint32(ssh, c->remoteid);
4225 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4227 c->v.v2.locwindow = newwin;
4232 * Handle the SSH2 userauth and connection layers.
4234 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4236 struct do_ssh2_authconn_state {
4238 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4240 AUTH_KEYBOARD_INTERACTIVE
4244 AUTH_TYPE_PUBLICKEY,
4245 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4246 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4248 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4249 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4251 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4252 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4253 int kbd_inter_running;
4255 int num_prompts, curr_prompt, echo;
4260 void *publickey_blob;
4261 int publickey_bloblen;
4262 unsigned char request[5], *response, *p;
4266 char *pkblob, *alg, *commentp;
4267 int pklen, alglen, commentlen;
4268 int siglen, retlen, len;
4269 char *q, *agentreq, *ret;
4272 crState(do_ssh2_authconn_state);
4274 crBegin(ssh->do_ssh2_authconn_crstate);
4277 * Request userauth protocol, and await a response to it.
4279 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4280 ssh2_pkt_addstring(ssh, "ssh-userauth");
4282 crWaitUntilV(ispkt);
4283 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4284 bombout(("Server refused user authentication protocol"));
4289 * We repeat this whole loop, including the username prompt,
4290 * until we manage a successful authentication. If the user
4291 * types the wrong _password_, they can be sent back to the
4292 * beginning to try another username, if this is configured on.
4293 * (If they specify a username in the config, they are never
4294 * asked, even if they do give a wrong password.)
4296 * I think this best serves the needs of
4298 * - the people who have no configuration, no keys, and just
4299 * want to try repeated (username,password) pairs until they
4300 * type both correctly
4302 * - people who have keys and configuration but occasionally
4303 * need to fall back to passwords
4305 * - people with a key held in Pageant, who might not have
4306 * logged in to a particular machine before; so they want to
4307 * type a username, and then _either_ their key will be
4308 * accepted, _or_ they will type a password. If they mistype
4309 * the username they will want to be able to get back and
4312 s->username[0] = '\0';
4313 s->got_username = FALSE;
4318 if (s->got_username && !cfg.change_username) {
4320 * We got a username last time round this loop, and
4321 * with change_username turned off we don't try to get
4324 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4325 if (ssh_get_line && !ssh_getline_pw_only) {
4326 if (!ssh_get_line("login as: ",
4327 s->username, sizeof(s->username), FALSE)) {
4329 * get_line failed to get a username.
4332 logevent("No username provided. Abandoning session.");
4333 ssh->state = SSH_STATE_CLOSED;
4337 int ret; /* need not be saved across crReturn */
4338 c_write_str(ssh, "login as: ");
4340 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4342 crWaitUntilV(!ispkt);
4343 ret = process_userpass_input(ssh, in, inlen);
4348 c_write_str(ssh, "\r\n");
4349 s->username[strcspn(s->username, "\n\r")] = '\0';
4352 strncpy(s->username, cfg.username, sizeof(s->username));
4353 s->username[sizeof(s->username)-1] = '\0';
4354 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4355 sprintf(stuff, "Using username \"%s\".\r\n", s->username);
4356 c_write_str(ssh, stuff);
4359 s->got_username = TRUE;
4362 * Send an authentication request using method "none": (a)
4363 * just in case it succeeds, and (b) so that we know what
4364 * authentication methods we can usefully try next.
4366 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4368 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4369 ssh2_pkt_addstring(ssh, s->username);
4370 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4371 ssh2_pkt_addstring(ssh, "none"); /* method */
4373 s->type = AUTH_TYPE_NONE;
4375 s->we_are_in = FALSE;
4377 s->tried_pubkey_config = FALSE;
4378 s->tried_agent = FALSE;
4379 s->tried_keyb_inter = FALSE;
4380 s->kbd_inter_running = FALSE;
4381 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4384 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4385 keytype = key_type(cfg.keyfile);
4386 if (keytype == SSH_KEYTYPE_SSH2) {
4388 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4389 &s->publickey_bloblen);
4392 logeventf("Unable to use this key file (%s)",
4393 key_type_to_str(keytype));
4394 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4395 cfg.keyfile, key_type_to_str(keytype));
4396 c_write_str(ssh, msgbuf);
4397 s->publickey_blob = NULL;
4400 s->publickey_blob = NULL;
4404 * Wait for the result of the last authentication request.
4407 crWaitUntilV(ispkt);
4408 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4412 * Don't show the banner if we're operating in
4413 * non-verbose non-interactive mode. (It's probably
4414 * a script, which means nobody will read the
4415 * banner _anyway_, and moreover the printing of
4416 * the banner will screw up processing on the
4417 * output of (say) plink.)
4419 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4420 ssh2_pkt_getstring(ssh, &banner, &size);
4422 c_write_untrusted(ssh, banner, size);
4424 crWaitUntilV(ispkt);
4426 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4427 logevent("Access granted");
4428 s->we_are_in = TRUE;
4432 if (s->kbd_inter_running &&
4433 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4435 * This is either a further set-of-prompts packet
4436 * in keyboard-interactive authentication, or it's
4437 * the same one and we came back here with `gotit'
4438 * set. In the former case, we must reset the
4439 * curr_prompt variable.
4443 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4444 bombout(("Strange packet received during authentication: type %d",
4452 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4453 * we can look at the string in it and know what we can
4454 * helpfully try next.
4456 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4459 ssh2_pkt_getstring(ssh, &methods, &methlen);
4460 s->kbd_inter_running = FALSE;
4461 if (!ssh2_pkt_getbool(ssh)) {
4463 * We have received an unequivocal Access
4464 * Denied. This can translate to a variety of
4467 * - if we'd just tried "none" authentication,
4468 * it's not worth printing anything at all
4470 * - if we'd just tried a public key _offer_,
4471 * the message should be "Server refused our
4472 * key" (or no message at all if the key
4473 * came from Pageant)
4475 * - if we'd just tried anything else, the
4476 * message really should be "Access denied".
4478 * Additionally, if we'd just tried password
4479 * authentication, we should break out of this
4480 * whole loop so as to go back to the username
4483 if (s->type == AUTH_TYPE_NONE) {
4485 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4486 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4487 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4488 c_write_str(ssh, "Server refused our key\r\n");
4489 logevent("Server refused public key");
4490 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4491 /* server declined keyboard-interactive; ignore */
4493 c_write_str(ssh, "Access denied\r\n");
4494 logevent("Access denied");
4495 if (s->type == AUTH_TYPE_PASSWORD) {
4496 s->we_are_in = FALSE;
4501 c_write_str(ssh, "Further authentication required\r\n");
4502 logevent("Further authentication required");
4506 in_commasep_string("publickey", methods, methlen);
4508 in_commasep_string("password", methods, methlen);
4509 s->can_keyb_inter = cfg.try_ki_auth &&
4510 in_commasep_string("keyboard-interactive", methods, methlen);
4514 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4517 * Most password/passphrase prompts will be
4518 * non-echoing, so we set this to 0 by default.
4519 * Exception is that some keyboard-interactive prompts
4520 * can be echoing, in which case we'll set this to 1.
4524 if (!s->method && s->can_pubkey &&
4525 agent_exists() && !s->tried_agent) {
4527 * Attempt public-key authentication using Pageant.
4532 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4533 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4535 s->tried_agent = TRUE;
4537 logevent("Pageant is running. Requesting keys.");
4539 /* Request the keys held by the agent. */
4540 PUT_32BIT(s->request, 1);
4541 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4542 agent_query(s->request, 5, &r, &s->responselen);
4543 s->response = (unsigned char *) r;
4544 if (s->response && s->responselen >= 5 &&
4545 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4546 s->p = s->response + 5;
4547 s->nkeys = GET_32BIT(s->p);
4551 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4554 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4559 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4562 s->pklen = GET_32BIT(s->p);
4564 if (s->publickey_blob &&
4565 s->pklen == s->publickey_bloblen &&
4566 !memcmp(s->p, s->publickey_blob,
4567 s->publickey_bloblen)) {
4568 logevent("This key matches configured key file");
4569 s->tried_pubkey_config = 1;
4573 s->alglen = GET_32BIT(s->pkblob);
4574 s->alg = s->pkblob + 4;
4575 s->commentlen = GET_32BIT(s->p);
4578 s->p += s->commentlen;
4579 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4580 ssh2_pkt_addstring(ssh, s->username);
4581 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4582 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4583 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4584 ssh2_pkt_addstring_start(ssh);
4585 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4586 ssh2_pkt_addstring_start(ssh);
4587 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4590 crWaitUntilV(ispkt);
4591 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4592 logevent("Key refused");
4596 if (flags & FLAG_VERBOSE) {
4597 c_write_str(ssh, "Authenticating with "
4599 c_write(ssh, s->commentp, s->commentlen);
4600 c_write_str(ssh, "\" from agent\r\n");
4604 * Server is willing to accept the key.
4605 * Construct a SIGN_REQUEST.
4607 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4608 ssh2_pkt_addstring(ssh, s->username);
4609 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4610 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4611 ssh2_pkt_addbool(ssh, TRUE);
4612 ssh2_pkt_addstring_start(ssh);
4613 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4614 ssh2_pkt_addstring_start(ssh);
4615 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4617 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4618 s->len = 1; /* message type */
4619 s->len += 4 + s->pklen; /* key blob */
4620 s->len += 4 + s->siglen; /* data to sign */
4621 s->len += 4; /* flags */
4622 s->agentreq = smalloc(4 + s->len);
4623 PUT_32BIT(s->agentreq, s->len);
4624 s->q = s->agentreq + 4;
4625 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4626 PUT_32BIT(s->q, s->pklen);
4628 memcpy(s->q, s->pkblob, s->pklen);
4630 PUT_32BIT(s->q, s->siglen);
4632 /* Now the data to be signed... */
4633 PUT_32BIT(s->q, 20);
4635 memcpy(s->q, ssh->v2_session_id, 20);
4637 memcpy(s->q, ssh->pktout.data + 5,
4638 ssh->pktout.length - 5);
4639 s->q += ssh->pktout.length - 5;
4640 /* And finally the (zero) flags word. */
4642 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4646 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4647 logevent("Sending Pageant's response");
4648 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4650 GET_32BIT(s->ret + 5));
4656 ("Pageant failed to answer challenge");
4666 if (!s->method && s->can_pubkey && s->publickey_blob
4667 && !s->tried_pubkey_config) {
4668 unsigned char *pub_blob;
4669 char *algorithm, *comment;
4672 s->tried_pubkey_config = TRUE;
4674 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4675 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4678 * Try the public key supplied in the configuration.
4680 * First, offer the public blob to see if the server is
4681 * willing to accept it.
4683 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4686 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4687 ssh2_pkt_addstring(ssh, s->username);
4688 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4689 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4690 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4691 ssh2_pkt_addstring(ssh, algorithm);
4692 ssh2_pkt_addstring_start(ssh);
4693 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4695 logevent("Offered public key"); /* FIXME */
4697 crWaitUntilV(ispkt);
4698 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4700 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4701 continue; /* key refused; give up on it */
4704 logevent("Offer of public key accepted");
4706 * Actually attempt a serious authentication using
4709 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4710 sprintf(s->pwprompt,
4711 "Passphrase for key \"%.100s\": ",
4717 c_write_str(ssh, "Authenticating with public key \"");
4718 c_write_str(ssh, comment);
4719 c_write_str(ssh, "\"\r\n");
4720 s->method = AUTH_PUBLICKEY_FILE;
4724 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4725 s->method = AUTH_KEYBOARD_INTERACTIVE;
4726 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4727 s->tried_keyb_inter = TRUE;
4729 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4730 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4732 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4733 ssh2_pkt_addstring(ssh, s->username);
4734 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4735 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4736 ssh2_pkt_addstring(ssh, ""); /* lang */
4737 ssh2_pkt_addstring(ssh, "");
4740 crWaitUntilV(ispkt);
4741 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4742 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4744 logevent("Keyboard-interactive authentication refused");
4745 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4749 s->kbd_inter_running = TRUE;
4753 if (s->kbd_inter_running) {
4754 s->method = AUTH_KEYBOARD_INTERACTIVE;
4755 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4756 s->tried_keyb_inter = TRUE;
4758 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4759 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4761 if (s->curr_prompt == 0) {
4763 * We've got a fresh USERAUTH_INFO_REQUEST.
4764 * Display header data, and start going through
4767 char *name, *inst, *lang;
4768 int name_len, inst_len, lang_len;
4770 ssh2_pkt_getstring(ssh, &name, &name_len);
4771 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4772 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4774 c_write_untrusted(ssh, name, name_len);
4775 c_write_str(ssh, "\r\n");
4778 c_write_untrusted(ssh, inst, inst_len);
4779 c_write_str(ssh, "\r\n");
4781 s->num_prompts = ssh2_pkt_getuint32(ssh);
4785 * If there are prompts remaining in the packet,
4786 * display one and get a response.
4788 if (s->curr_prompt < s->num_prompts) {
4792 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4793 if (prompt_len > 0) {
4794 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4795 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4796 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4799 "<server failed to send prompt>: ");
4801 s->echo = ssh2_pkt_getbool(ssh);
4807 if (!s->method && s->can_passwd) {
4808 s->method = AUTH_PASSWORD;
4809 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4810 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4811 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4818 if (!ssh_get_line(s->pwprompt, s->password,
4819 sizeof(s->password), TRUE)) {
4821 * get_line failed to get a password (for
4822 * example because one was supplied on the
4823 * command line which has already failed to
4826 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4827 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4828 ssh2_pkt_addstring(ssh, "No more passwords available"
4830 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4832 logevent("Unable to authenticate");
4833 connection_fatal("Unable to authenticate");
4834 ssh->state = SSH_STATE_CLOSED;
4838 int ret; /* need not be saved across crReturn */
4839 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4842 setup_userpass_input(ssh, s->password,
4843 sizeof(s->password), s->echo);
4845 crWaitUntilV(!ispkt);
4846 ret = process_userpass_input(ssh, in, inlen);
4850 c_write_str(ssh, "\r\n");
4854 if (s->method == AUTH_PUBLICKEY_FILE) {
4856 * We have our passphrase. Now try the actual authentication.
4858 struct ssh2_userkey *key;
4860 key = ssh2_load_userkey(cfg.keyfile, s->password);
4861 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4862 if (key == SSH2_WRONG_PASSPHRASE) {
4863 c_write_str(ssh, "Wrong passphrase\r\n");
4864 s->tried_pubkey_config = FALSE;
4866 c_write_str(ssh, "Unable to load private key\r\n");
4867 s->tried_pubkey_config = TRUE;
4869 /* Send a spurious AUTH_NONE to return to the top. */
4870 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4871 ssh2_pkt_addstring(ssh, s->username);
4872 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4873 ssh2_pkt_addstring(ssh, "none"); /* method */
4875 s->type = AUTH_TYPE_NONE;
4877 unsigned char *pkblob, *sigblob, *sigdata;
4878 int pkblob_len, sigblob_len, sigdata_len;
4881 * We have loaded the private key and the server
4882 * has announced that it's willing to accept it.
4883 * Hallelujah. Generate a signature and send it.
4885 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4886 ssh2_pkt_addstring(ssh, s->username);
4887 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4888 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4889 ssh2_pkt_addbool(ssh, TRUE);
4890 ssh2_pkt_addstring(ssh, key->alg->name);
4891 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4892 ssh2_pkt_addstring_start(ssh);
4893 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
4896 * The data to be signed is:
4900 * followed by everything so far placed in the
4903 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4904 sigdata = smalloc(sigdata_len);
4905 PUT_32BIT(sigdata, 20);
4906 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4907 memcpy(sigdata + 24, ssh->pktout.data + 5,
4908 ssh->pktout.length - 5);
4909 sigblob = key->alg->sign(key->data, sigdata,
4910 sigdata_len, &sigblob_len);
4911 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4912 sigblob, sigblob_len);
4918 s->type = AUTH_TYPE_PUBLICKEY;
4920 } else if (s->method == AUTH_PASSWORD) {
4922 * We send the password packet lumped tightly together with
4923 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4924 * string long enough to make the total length of the two
4925 * packets constant. This should ensure that a passive
4926 * listener doing traffic analyis can't work out the length
4929 * For this to work, we need an assumption about the
4930 * maximum length of the password packet. I think 256 is
4931 * pretty conservative. Anyone using a password longer than
4932 * that probably doesn't have much to worry about from
4933 * people who find out how long their password is!
4935 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4936 ssh2_pkt_addstring(ssh, s->username);
4937 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4938 ssh2_pkt_addstring(ssh, "password");
4939 ssh2_pkt_addbool(ssh, FALSE);
4940 ssh2_pkt_addstring(ssh, s->password);
4941 ssh2_pkt_defer(ssh);
4943 * We'll include a string that's an exact multiple of the
4944 * cipher block size. If the cipher is NULL for some
4945 * reason, we don't do this trick at all because we gain
4948 if (ssh->cscipher) {
4951 stringlen = (256 - ssh->deferred_len);
4952 stringlen += ssh->cscipher->blksize - 1;
4953 stringlen -= (stringlen % ssh->cscipher->blksize);
4956 * Temporarily disable actual compression,
4957 * so we can guarantee to get this string
4958 * exactly the length we want it. The
4959 * compression-disabling routine should
4960 * return an integer indicating how many
4961 * bytes we should adjust our string length
4965 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4967 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4968 ssh2_pkt_addstring_start(ssh);
4969 for (i = 0; i < stringlen; i++) {
4970 char c = (char) random_byte();
4971 ssh2_pkt_addstring_data(ssh, &c, 1);
4973 ssh2_pkt_defer(ssh);
4975 ssh_pkt_defersend(ssh);
4976 logevent("Sent password");
4977 s->type = AUTH_TYPE_PASSWORD;
4978 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4979 if (s->curr_prompt == 0) {
4980 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4981 ssh2_pkt_adduint32(ssh, s->num_prompts);
4983 if (s->need_pw) { /* only add pw if we just got one! */
4984 ssh2_pkt_addstring(ssh, s->password);
4985 memset(s->password, 0, sizeof(s->password));
4988 if (s->curr_prompt >= s->num_prompts) {
4992 * If there are prompts remaining, we set
4993 * `gotit' so that we won't attempt to get
4994 * another packet. Then we go back round the
4995 * loop and will end up retrieving another
4996 * prompt out of the existing packet. Funky or
5001 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5003 c_write_str(ssh, "No supported authentication methods"
5004 " left to try!\r\n");
5005 logevent("No supported authentications offered."
5007 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5008 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5009 ssh2_pkt_addstring(ssh, "No supported authentication"
5010 " methods available");
5011 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5013 ssh->state = SSH_STATE_CLOSED;
5017 } while (!s->we_are_in);
5020 * Now we're authenticated for the connection protocol. The
5021 * connection protocol will automatically have started at this
5022 * point; there's no need to send SERVICE_REQUEST.
5026 * So now create a channel with a session in it.
5028 ssh->channels = newtree234(ssh_channelcmp);
5029 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5030 ssh->mainchan->ssh = ssh;
5031 ssh->mainchan->localid = alloc_channel_id(ssh);
5032 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5033 ssh2_pkt_addstring(ssh, "session");
5034 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5035 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5036 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5037 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5039 crWaitUntilV(ispkt);
5040 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5041 bombout(("Server refused to open a session"));
5043 /* FIXME: error data comes back in FAILURE packet */
5045 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5046 bombout(("Server's channel confirmation cited wrong channel"));
5049 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5050 ssh->mainchan->type = CHAN_MAINSESSION;
5051 ssh->mainchan->closes = 0;
5052 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5053 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5054 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5055 add234(ssh->channels, ssh->mainchan);
5056 logevent("Opened channel for session");
5059 * Potentially enable X11 forwarding.
5061 if (cfg.x11_forward) {
5062 char proto[20], data[64];
5063 logevent("Requesting X11 forwarding");
5064 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5065 data, sizeof(data));
5066 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5067 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5068 ssh2_pkt_addstring(ssh, "x11-req");
5069 ssh2_pkt_addbool(ssh, 1); /* want reply */
5070 ssh2_pkt_addbool(ssh, 0); /* many connections */
5071 ssh2_pkt_addstring(ssh, proto);
5072 ssh2_pkt_addstring(ssh, data);
5073 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5077 crWaitUntilV(ispkt);
5078 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5079 unsigned i = ssh2_pkt_getuint32(ssh);
5080 struct ssh_channel *c;
5081 c = find234(ssh->channels, &i, ssh_channelfind);
5083 continue; /* nonexistent channel */
5084 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5086 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5088 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5089 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5090 bombout(("Unexpected response to X11 forwarding request:"
5091 " packet type %d", ssh->pktin.type));
5094 logevent("X11 forwarding refused");
5096 logevent("X11 forwarding enabled");
5097 ssh->X11_fwd_enabled = TRUE;
5102 * Enable port forwardings.
5107 int sport,dport,sserv,dserv;
5108 char sports[256], dports[256], host[256];
5112 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5113 /* Add port forwardings. */
5114 ssh->portfwd_strptr = cfg.portfwd;
5115 while (*ssh->portfwd_strptr) {
5116 type = *ssh->portfwd_strptr++;
5118 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5119 sports[n++] = *ssh->portfwd_strptr++;
5121 if (*ssh->portfwd_strptr == '\t')
5122 ssh->portfwd_strptr++;
5124 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5125 host[n++] = *ssh->portfwd_strptr++;
5127 if (*ssh->portfwd_strptr == ':')
5128 ssh->portfwd_strptr++;
5130 while (*ssh->portfwd_strptr)
5131 dports[n++] = *ssh->portfwd_strptr++;
5133 ssh->portfwd_strptr++;
5134 dport = atoi(dports);
5138 se = getservbyname(dports, NULL);
5140 dport = ntohs(se->s_port);
5143 "Service lookup failed for destination port \"%s\"",
5148 sport = atoi(sports);
5152 se = getservbyname(sports, NULL);
5154 sport = ntohs(se->s_port);
5157 "Service lookup failed for source port \"%s\"",
5162 if (sport && dport) {
5164 pfd_addforward(host, dport, sport, ssh);
5165 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5166 " %s:%.*s%.*s%d%.*s",
5167 sserv ? strlen(sports) : 0, sports,
5168 sserv, "(", sport, sserv, ")",
5170 dserv ? strlen(dports) : 0, dports,
5171 dserv, "(", dport, dserv, ")");
5174 struct ssh_rportfwd *pf;
5175 pf = smalloc(sizeof(*pf));
5176 strcpy(pf->dhost, host);
5179 if (add234(ssh->rportfwds, pf) != pf) {
5181 "Duplicate remote port forwarding to %s:%d",
5186 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5187 " forward to %s:%.*s%.*s%d%.*s",
5188 sserv ? strlen(sports) : 0, sports,
5189 sserv, "(", sport, sserv, ")",
5191 dserv ? strlen(dports) : 0, dports,
5192 dserv, "(", dport, dserv, ")");
5194 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5195 ssh2_pkt_addstring(ssh, "tcpip-forward");
5196 ssh2_pkt_addbool(ssh, 1);/* want reply */
5197 if (cfg.rport_acceptall)
5198 ssh2_pkt_addstring(ssh, "0.0.0.0");
5200 ssh2_pkt_addstring(ssh, "127.0.0.1");
5201 ssh2_pkt_adduint32(ssh, sport);
5205 crWaitUntilV(ispkt);
5206 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5207 unsigned i = ssh2_pkt_getuint32(ssh);
5208 struct ssh_channel *c;
5209 c = find234(ssh->channels, &i, ssh_channelfind);
5211 continue;/* nonexistent channel */
5212 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5214 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5216 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5217 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5218 bombout(("Unexpected response to port "
5219 "forwarding request: packet type %d",
5223 logevent("Server refused this port forwarding");
5225 logevent("Remote port forwarding enabled");
5234 * Potentially enable agent forwarding.
5236 if (cfg.agentfwd && agent_exists()) {
5237 logevent("Requesting OpenSSH-style agent forwarding");
5238 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5239 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5240 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5241 ssh2_pkt_addbool(ssh, 1); /* want reply */
5245 crWaitUntilV(ispkt);
5246 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5247 unsigned i = ssh2_pkt_getuint32(ssh);
5248 struct ssh_channel *c;
5249 c = find234(ssh->channels, &i, ssh_channelfind);
5251 continue; /* nonexistent channel */
5252 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5254 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5256 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5257 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5258 bombout(("Unexpected response to agent forwarding request:"
5259 " packet type %d", ssh->pktin.type));
5262 logevent("Agent forwarding refused");
5264 logevent("Agent forwarding enabled");
5265 ssh->agentfwd_enabled = TRUE;
5270 * Now allocate a pty for the session.
5273 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5274 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5275 ssh2_pkt_addstring(ssh, "pty-req");
5276 ssh2_pkt_addbool(ssh, 1); /* want reply */
5277 ssh2_pkt_addstring(ssh, cfg.termtype);
5278 ssh2_pkt_adduint32(ssh, ssh->term_width);
5279 ssh2_pkt_adduint32(ssh, ssh->term_height);
5280 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5281 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5282 ssh2_pkt_addstring_start(ssh);
5283 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5285 ssh->state = SSH_STATE_INTERMED;
5288 crWaitUntilV(ispkt);
5289 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5290 unsigned i = ssh2_pkt_getuint32(ssh);
5291 struct ssh_channel *c;
5292 c = find234(ssh->channels, &i, ssh_channelfind);
5294 continue; /* nonexistent channel */
5295 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5297 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5299 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5300 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5301 bombout(("Unexpected response to pty request:"
5302 " packet type %d", ssh->pktin.type));
5305 c_write_str(ssh, "Server refused to allocate pty\r\n");
5306 ssh->editing = ssh->echoing = 1;
5308 logevent("Allocated pty");
5311 ssh->editing = ssh->echoing = 1;
5315 * Start a shell or a remote command. We may have to attempt
5316 * this twice if the config data has provided a second choice
5323 if (ssh->fallback_cmd) {
5324 subsys = cfg.ssh_subsys2;
5325 cmd = cfg.remote_cmd_ptr2;
5327 subsys = cfg.ssh_subsys;
5328 cmd = cfg.remote_cmd_ptr;
5331 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5332 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5334 ssh2_pkt_addstring(ssh, "subsystem");
5335 ssh2_pkt_addbool(ssh, 1); /* want reply */
5336 ssh2_pkt_addstring(ssh, cmd);
5338 ssh2_pkt_addstring(ssh, "exec");
5339 ssh2_pkt_addbool(ssh, 1); /* want reply */
5340 ssh2_pkt_addstring(ssh, cmd);
5342 ssh2_pkt_addstring(ssh, "shell");
5343 ssh2_pkt_addbool(ssh, 1); /* want reply */
5347 crWaitUntilV(ispkt);
5348 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5349 unsigned i = ssh2_pkt_getuint32(ssh);
5350 struct ssh_channel *c;
5351 c = find234(ssh->channels, &i, ssh_channelfind);
5353 continue; /* nonexistent channel */
5354 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5356 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5357 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5358 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5359 bombout(("Unexpected response to shell/command request:"
5360 " packet type %d", ssh->pktin.type));
5364 * We failed to start the command. If this is the
5365 * fallback command, we really are finished; if it's
5366 * not, and if the fallback command exists, try falling
5367 * back to it before complaining.
5369 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5370 logevent("Primary command failed; attempting fallback");
5371 ssh->fallback_cmd = TRUE;
5374 bombout(("Server refused to start a shell/command"));
5377 logevent("Started a shell/command");
5382 ssh->state = SSH_STATE_SESSION;
5383 if (ssh->size_needed)
5384 ssh_size(ssh, ssh->term_width, ssh->term_height);
5385 if (ssh->eof_needed)
5386 ssh_special(ssh, TS_EOF);
5392 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5396 s->try_send = FALSE;
5398 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5399 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5402 unsigned i = ssh2_pkt_getuint32(ssh);
5403 struct ssh_channel *c;
5404 c = find234(ssh->channels, &i, ssh_channelfind);
5406 continue; /* nonexistent channel */
5407 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5408 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5409 continue; /* extended but not stderr */
5410 ssh2_pkt_getstring(ssh, &data, &length);
5413 c->v.v2.locwindow -= length;
5415 case CHAN_MAINSESSION:
5417 from_backend(ssh->frontend, ssh->pktin.type ==
5418 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5422 bufsize = x11_send(c->u.x11.s, data, length);
5425 bufsize = pfd_send(c->u.pfd.s, data, length);
5428 while (length > 0) {
5429 if (c->u.a.lensofar < 4) {
5430 int l = min(4 - c->u.a.lensofar, length);
5431 memcpy(c->u.a.msglen + c->u.a.lensofar,
5435 c->u.a.lensofar += l;
5437 if (c->u.a.lensofar == 4) {
5439 4 + GET_32BIT(c->u.a.msglen);
5440 c->u.a.message = smalloc(c->u.a.totallen);
5441 memcpy(c->u.a.message, c->u.a.msglen, 4);
5443 if (c->u.a.lensofar >= 4 && length > 0) {
5445 min(c->u.a.totallen - c->u.a.lensofar,
5447 memcpy(c->u.a.message + c->u.a.lensofar,
5451 c->u.a.lensofar += l;
5453 if (c->u.a.lensofar == c->u.a.totallen) {
5454 void *reply, *sentreply;
5456 agent_query(c->u.a.message,
5457 c->u.a.totallen, &reply,
5462 /* Fake SSH_AGENT_FAILURE. */
5463 sentreply = "\0\0\0\1\5";
5466 ssh2_add_channel_data(c, sentreply, replylen);
5470 sfree(c->u.a.message);
5471 c->u.a.lensofar = 0;
5478 * If we are not buffering too much data,
5479 * enlarge the window again at the remote side.
5481 if (bufsize < OUR_V2_WINSIZE)
5482 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5484 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5485 unsigned i = ssh2_pkt_getuint32(ssh);
5486 struct ssh_channel *c;
5488 c = find234(ssh->channels, &i, ssh_channelfind);
5490 continue; /* nonexistent channel */
5492 if (c->type == CHAN_X11) {
5494 * Remote EOF on an X11 channel means we should
5495 * wrap up and close the channel ourselves.
5497 x11_close(c->u.x11.s);
5499 } else if (c->type == CHAN_AGENT) {
5501 } else if (c->type == CHAN_SOCKDATA) {
5502 pfd_close(c->u.pfd.s);
5505 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5506 unsigned i = ssh2_pkt_getuint32(ssh);
5507 struct ssh_channel *c;
5509 c = find234(ssh->channels, &i, ssh_channelfind);
5510 if (!c || ((int)c->remoteid) == -1) {
5511 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5512 c ? "half-open" : "nonexistent", i));
5514 /* Do pre-close processing on the channel. */
5516 case CHAN_MAINSESSION:
5517 break; /* nothing to see here, move along */
5519 if (c->u.x11.s != NULL)
5520 x11_close(c->u.x11.s);
5527 if (c->u.pfd.s != NULL)
5528 pfd_close(c->u.pfd.s);
5532 if (c->closes == 0) {
5533 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5534 ssh2_pkt_adduint32(ssh, c->remoteid);
5537 del234(ssh->channels, c);
5538 bufchain_clear(&c->v.v2.outbuffer);
5542 * See if that was the last channel left open.
5544 if (count234(ssh->channels) == 0) {
5547 * We used to send SSH_MSG_DISCONNECT here,
5548 * because I'd believed that _every_ conforming
5549 * SSH2 connection had to end with a disconnect
5550 * being sent by at least one side; apparently
5551 * I was wrong and it's perfectly OK to
5552 * unceremoniously slam the connection shut
5553 * when you're done, and indeed OpenSSH feels
5554 * this is more polite than sending a
5555 * DISCONNECT. So now we don't.
5557 logevent("All channels closed. Disconnecting");
5558 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5559 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5560 ssh2_pkt_addstring(ssh, "All open channels closed");
5561 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5564 ssh->state = SSH_STATE_CLOSED;
5567 continue; /* remote sends close; ignore (FIXME) */
5568 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5569 unsigned i = ssh2_pkt_getuint32(ssh);
5570 struct ssh_channel *c;
5571 c = find234(ssh->channels, &i, ssh_channelfind);
5573 continue; /* nonexistent channel */
5574 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5576 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5577 unsigned i = ssh2_pkt_getuint32(ssh);
5578 struct ssh_channel *c;
5579 c = find234(ssh->channels, &i, ssh_channelfind);
5581 continue; /* nonexistent channel */
5582 if (c->type != CHAN_SOCKDATA_DORMANT)
5583 continue; /* dunno why they're confirming this */
5584 c->remoteid = ssh2_pkt_getuint32(ssh);
5585 c->type = CHAN_SOCKDATA;
5586 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5587 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5589 pfd_confirm(c->u.pfd.s);
5592 * We have a pending close on this channel,
5593 * which we decided on before the server acked
5594 * the channel open. So now we know the
5595 * remoteid, we can close it again.
5597 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5598 ssh2_pkt_adduint32(ssh, c->remoteid);
5601 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5602 unsigned i = ssh2_pkt_getuint32(ssh);
5603 struct ssh_channel *c;
5604 c = find234(ssh->channels, &i, ssh_channelfind);
5606 continue; /* nonexistent channel */
5607 if (c->type != CHAN_SOCKDATA_DORMANT)
5608 continue; /* dunno why they're failing this */
5610 logevent("Forwarded connection refused by server");
5612 pfd_close(c->u.pfd.s);
5614 del234(ssh->channels, c);
5616 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5619 int typelen, want_reply;
5620 struct ssh_channel *c;
5622 localid = ssh2_pkt_getuint32(ssh);
5623 ssh2_pkt_getstring(ssh, &type, &typelen);
5624 want_reply = ssh2_pkt_getbool(ssh);
5627 * First, check that the channel exists. Otherwise,
5628 * we can instantly disconnect with a rude message.
5630 c = find234(ssh->channels, &localid, ssh_channelfind);
5633 sprintf(buf, "Received channel request for nonexistent"
5634 " channel %d", localid);
5636 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5637 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5638 ssh2_pkt_addstring(ssh, buf);
5639 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5641 connection_fatal("%s", buf);
5642 ssh->state = SSH_STATE_CLOSED;
5647 * Having got the channel number, we now look at
5648 * the request type string to see if it's something
5651 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5652 c == ssh->mainchan) {
5653 /* We recognise "exit-status" on the primary channel. */
5655 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5656 sprintf(buf, "Server sent command exit status %d",
5660 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5661 ssh2_pkt_adduint32(ssh, c->remoteid);
5666 * This is a channel request we don't know
5667 * about, so we now either ignore the request
5668 * or respond with CHANNEL_FAILURE, depending
5672 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5673 ssh2_pkt_adduint32(ssh, c->remoteid);
5677 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5679 int typelen, want_reply;
5681 ssh2_pkt_getstring(ssh, &type, &typelen);
5682 want_reply = ssh2_pkt_getbool(ssh);
5685 * We currently don't support any global requests
5686 * at all, so we either ignore the request or
5687 * respond with REQUEST_FAILURE, depending on
5691 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5694 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5698 struct ssh_channel *c;
5699 unsigned remid, winsize, pktsize;
5700 ssh2_pkt_getstring(ssh, &type, &typelen);
5701 c = smalloc(sizeof(struct ssh_channel));
5704 remid = ssh2_pkt_getuint32(ssh);
5705 winsize = ssh2_pkt_getuint32(ssh);
5706 pktsize = ssh2_pkt_getuint32(ssh);
5708 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5709 if (!ssh->X11_fwd_enabled)
5710 error = "X11 forwarding is not enabled";
5711 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5712 ssh->x11auth) != NULL) {
5713 error = "Unable to open an X11 connection";
5717 } else if (typelen == 15 &&
5718 !memcmp(type, "forwarded-tcpip", 15)) {
5719 struct ssh_rportfwd pf, *realpf;
5722 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5723 pf.sport = ssh2_pkt_getuint32(ssh);
5724 realpf = find234(ssh->rportfwds, &pf, NULL);
5725 if (realpf == NULL) {
5726 error = "Remote port is not recognised";
5728 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5731 sprintf(buf, "Received remote port open request for %s:%d",
5732 realpf->dhost, realpf->dport);
5735 sprintf(buf, "Port open failed: %s", e);
5737 error = "Port open failed";
5739 logevent("Forwarded port opened successfully");
5740 c->type = CHAN_SOCKDATA;
5743 } else if (typelen == 22 &&
5744 !memcmp(type, "auth-agent@openssh.com", 3)) {
5745 if (!ssh->agentfwd_enabled)
5746 error = "Agent forwarding is not enabled";
5748 c->type = CHAN_AGENT; /* identify channel type */
5749 c->u.a.lensofar = 0;
5752 error = "Unsupported channel type requested";
5755 c->remoteid = remid;
5757 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5758 ssh2_pkt_adduint32(ssh, c->remoteid);
5759 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5760 ssh2_pkt_addstring(ssh, error);
5761 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5765 c->localid = alloc_channel_id(ssh);
5767 c->v.v2.locwindow = OUR_V2_WINSIZE;
5768 c->v.v2.remwindow = winsize;
5769 c->v.v2.remmaxpkt = pktsize;
5770 bufchain_init(&c->v.v2.outbuffer);
5771 add234(ssh->channels, c);
5772 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5773 ssh2_pkt_adduint32(ssh, c->remoteid);
5774 ssh2_pkt_adduint32(ssh, c->localid);
5775 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5776 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5780 bombout(("Strange packet received: type %d", ssh->pktin.type));
5785 * We have spare data. Add it to the channel buffer.
5787 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5792 struct ssh_channel *c;
5794 * Try to send data on all channels if we can.
5796 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5797 int bufsize = ssh2_try_send(c);
5800 case CHAN_MAINSESSION:
5801 /* stdin need not receive an unthrottle
5802 * notification since it will be polled */
5805 x11_unthrottle(c->u.x11.s);
5808 /* agent sockets are request/response and need no
5809 * buffer management */
5812 pfd_unthrottle(c->u.pfd.s);
5824 * Handle the top-level SSH2 protocol.
5826 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5828 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5830 do_ssh2_authconn(ssh, in, inlen, ispkt);
5834 * Called to set up the connection.
5836 * Returns an error message, or NULL on success.
5838 static char *ssh_init(void *frontend_handle, void **backend_handle,
5839 char *host, int port, char **realhost, int nodelay)
5844 ssh = smalloc(sizeof(*ssh));
5847 ssh->v1_cipher_ctx = NULL;
5848 ssh->crcda_ctx = NULL;
5849 ssh->cscipher = NULL;
5850 ssh->cs_cipher_ctx = NULL;
5851 ssh->sccipher = NULL;
5852 ssh->sc_cipher_ctx = NULL;
5854 ssh->sc_mac_ctx = NULL;
5856 ssh->sc_mac_ctx = NULL;
5858 ssh->cs_comp_ctx = NULL;
5860 ssh->sc_comp_ctx = NULL;
5862 ssh->hostkey = NULL;
5864 ssh->state = SSH_STATE_PREPACKET;
5865 ssh->size_needed = FALSE;
5866 ssh->eof_needed = FALSE;
5869 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5870 ssh->pktin = ssh->pktout = empty;
5872 ssh->deferred_send_data = NULL;
5873 ssh->deferred_len = 0;
5874 ssh->deferred_size = 0;
5875 ssh->fallback_cmd = 0;
5877 ssh->x11auth = NULL;
5878 ssh->v2_outgoing_sequence = 0;
5879 ssh->ssh1_rdpkt_crstate = 0;
5880 ssh->ssh2_rdpkt_crstate = 0;
5881 ssh->do_ssh_init_crstate = 0;
5882 ssh->ssh_gotdata_crstate = 0;
5883 ssh->ssh1_protocol_crstate = 0;
5884 ssh->do_ssh1_login_crstate = 0;
5885 ssh->do_ssh2_transport_crstate = 0;
5886 ssh->do_ssh2_authconn_crstate = 0;
5887 ssh->do_ssh_init_state = NULL;
5888 ssh->do_ssh1_login_state = NULL;
5889 ssh->do_ssh2_transport_state = NULL;
5890 ssh->do_ssh2_authconn_state = NULL;
5892 *backend_handle = ssh;
5895 if (crypto_startup() == 0)
5896 return "Microsoft high encryption pack not installed!";
5899 ssh->frontend = frontend_handle;
5900 ssh->term_width = cfg.width;
5901 ssh->term_height = cfg.height;
5906 ssh->v1_throttle_count = 0;
5907 ssh->overall_bufsize = 0;
5908 ssh->fallback_cmd = 0;
5910 p = connect_to_host(ssh, host, port, realhost, nodelay);
5918 * Called to send data down the Telnet connection.
5920 static int ssh_send(void *handle, char *buf, int len)
5922 Ssh ssh = (Ssh) handle;
5924 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5927 ssh->protocol(ssh, buf, len, 0);
5929 return ssh_sendbuffer(ssh);
5933 * Called to query the current amount of buffered stdin data.
5935 static int ssh_sendbuffer(void *handle)
5937 Ssh ssh = (Ssh) handle;
5940 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5944 * If the SSH socket itself has backed up, add the total backup
5945 * size on that to any individual buffer on the stdin channel.
5948 if (ssh->throttled_all)
5949 override_value = ssh->overall_bufsize;
5951 if (ssh->version == 1) {
5952 return override_value;
5953 } else if (ssh->version == 2) {
5954 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5955 return override_value;
5957 return (override_value +
5958 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5965 * Called to set the size of the window from SSH's POV.
5967 static void ssh_size(void *handle, int width, int height)
5969 Ssh ssh = (Ssh) handle;
5971 ssh->term_width = width;
5972 ssh->term_height = height;
5974 switch (ssh->state) {
5975 case SSH_STATE_BEFORE_SIZE:
5976 case SSH_STATE_PREPACKET:
5977 case SSH_STATE_CLOSED:
5978 break; /* do nothing */
5979 case SSH_STATE_INTERMED:
5980 ssh->size_needed = TRUE; /* buffer for later */
5982 case SSH_STATE_SESSION:
5984 if (ssh->version == 1) {
5985 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
5986 PKT_INT, ssh->term_height,
5987 PKT_INT, ssh->term_width,
5988 PKT_INT, 0, PKT_INT, 0, PKT_END);
5990 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5991 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5992 ssh2_pkt_addstring(ssh, "window-change");
5993 ssh2_pkt_addbool(ssh, 0);
5994 ssh2_pkt_adduint32(ssh, ssh->term_width);
5995 ssh2_pkt_adduint32(ssh, ssh->term_height);
5996 ssh2_pkt_adduint32(ssh, 0);
5997 ssh2_pkt_adduint32(ssh, 0);
6006 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6007 * can send an EOF and collect resulting output (e.g. `plink
6010 static void ssh_special(void *handle, Telnet_Special code)
6012 Ssh ssh = (Ssh) handle;
6014 if (code == TS_EOF) {
6015 if (ssh->state != SSH_STATE_SESSION) {
6017 * Buffer the EOF in case we are pre-SESSION, so we can
6018 * send it as soon as we reach SESSION.
6021 ssh->eof_needed = TRUE;
6024 if (ssh->version == 1) {
6025 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6027 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6028 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6031 logevent("Sent EOF message");
6032 } else if (code == TS_PING) {
6033 if (ssh->state == SSH_STATE_CLOSED
6034 || ssh->state == SSH_STATE_PREPACKET) return;
6035 if (ssh->version == 1) {
6036 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6037 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6039 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6040 ssh2_pkt_addstring_start(ssh);
6048 void *new_sock_channel(void *handle, Socket s)
6050 Ssh ssh = (Ssh) handle;
6051 struct ssh_channel *c;
6052 c = smalloc(sizeof(struct ssh_channel));
6056 c->remoteid = -1; /* to be set when open confirmed */
6057 c->localid = alloc_channel_id(ssh);
6059 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6061 bufchain_init(&c->v.v2.outbuffer);
6062 add234(ssh->channels, c);
6068 * This is called when stdout/stderr (the entity to which
6069 * from_backend sends data) manages to clear some backlog.
6071 void ssh_unthrottle(void *handle, int bufsize)
6073 Ssh ssh = (Ssh) handle;
6074 if (ssh->version == 1) {
6075 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6076 ssh->v1_stdout_throttling = 0;
6077 ssh1_throttle(ssh, -1);
6080 if (ssh->mainchan && ssh->mainchan->closes == 0)
6081 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6085 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6087 struct ssh_channel *c = (struct ssh_channel *)channel;
6091 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
6094 if (ssh->version == 1) {
6095 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6096 PKT_INT, c->localid,
6099 //PKT_STR, <org:orgport>,
6102 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6103 ssh2_pkt_addstring(ssh, "direct-tcpip");
6104 ssh2_pkt_adduint32(ssh, c->localid);
6105 c->v.v2.locwindow = OUR_V2_WINSIZE;
6106 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6107 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6108 ssh2_pkt_addstring(ssh, hostname);
6109 ssh2_pkt_adduint32(ssh, port);
6111 * We make up values for the originator data; partly it's
6112 * too much hassle to keep track, and partly I'm not
6113 * convinced the server should be told details like that
6114 * about my local network configuration.
6116 ssh2_pkt_addstring(ssh, "client-side-connection");
6117 ssh2_pkt_adduint32(ssh, 0);
6123 static Socket ssh_socket(void *handle)
6125 Ssh ssh = (Ssh) handle;
6129 static int ssh_sendok(void *handle)
6131 Ssh ssh = (Ssh) handle;
6132 return ssh->send_ok;
6135 static int ssh_ldisc(void *handle, int option)
6137 Ssh ssh = (Ssh) handle;
6138 if (option == LD_ECHO)
6139 return ssh->echoing;
6140 if (option == LD_EDIT)
6141 return ssh->editing;
6145 static void ssh_provide_ldisc(void *handle, void *ldisc)
6147 Ssh ssh = (Ssh) handle;
6151 static int ssh_return_exitcode(void *handle)
6153 Ssh ssh = (Ssh) handle;
6154 return ssh->exitcode;
6158 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6159 * that fails. This variable is the means by which scp.c can reach
6160 * into the SSH code and find out which one it got.
6162 extern int ssh_fallback_cmd(void *handle)
6164 Ssh ssh = (Ssh) handle;
6165 return ssh->fallback_cmd;
6168 Backend ssh_backend = {
6175 ssh_return_exitcode,