17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
167 #define translate(x) if (type == x) return #x
168 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
169 char *ssh1_pkt_type(int type)
171 translate(SSH1_MSG_DISCONNECT);
172 translate(SSH1_SMSG_PUBLIC_KEY);
173 translate(SSH1_CMSG_SESSION_KEY);
174 translate(SSH1_CMSG_USER);
175 translate(SSH1_CMSG_AUTH_RSA);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
178 translate(SSH1_CMSG_AUTH_PASSWORD);
179 translate(SSH1_CMSG_REQUEST_PTY);
180 translate(SSH1_CMSG_WINDOW_SIZE);
181 translate(SSH1_CMSG_EXEC_SHELL);
182 translate(SSH1_CMSG_EXEC_CMD);
183 translate(SSH1_SMSG_SUCCESS);
184 translate(SSH1_SMSG_FAILURE);
185 translate(SSH1_CMSG_STDIN_DATA);
186 translate(SSH1_SMSG_STDOUT_DATA);
187 translate(SSH1_SMSG_STDERR_DATA);
188 translate(SSH1_CMSG_EOF);
189 translate(SSH1_SMSG_EXIT_STATUS);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
192 translate(SSH1_MSG_CHANNEL_DATA);
193 translate(SSH1_MSG_CHANNEL_CLOSE);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
195 translate(SSH1_SMSG_X11_OPEN);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
197 translate(SSH1_MSG_PORT_OPEN);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
199 translate(SSH1_SMSG_AGENT_OPEN);
200 translate(SSH1_MSG_IGNORE);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
204 translate(SSH1_MSG_DEBUG);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION);
206 translate(SSH1_CMSG_AUTH_TIS);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
209 translate(SSH1_CMSG_AUTH_CCARD);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
214 char *ssh2_pkt_type(int pkt_ctx, int type)
216 translate(SSH2_MSG_DISCONNECT);
217 translate(SSH2_MSG_IGNORE);
218 translate(SSH2_MSG_UNIMPLEMENTED);
219 translate(SSH2_MSG_DEBUG);
220 translate(SSH2_MSG_SERVICE_REQUEST);
221 translate(SSH2_MSG_SERVICE_ACCEPT);
222 translate(SSH2_MSG_KEXINIT);
223 translate(SSH2_MSG_NEWKEYS);
224 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
225 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
230 translate(SSH2_MSG_USERAUTH_REQUEST);
231 translate(SSH2_MSG_USERAUTH_FAILURE);
232 translate(SSH2_MSG_USERAUTH_SUCCESS);
233 translate(SSH2_MSG_USERAUTH_BANNER);
234 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
238 translate(SSH2_MSG_GLOBAL_REQUEST);
239 translate(SSH2_MSG_REQUEST_SUCCESS);
240 translate(SSH2_MSG_REQUEST_FAILURE);
241 translate(SSH2_MSG_CHANNEL_OPEN);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
245 translate(SSH2_MSG_CHANNEL_DATA);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
247 translate(SSH2_MSG_CHANNEL_EOF);
248 translate(SSH2_MSG_CHANNEL_CLOSE);
249 translate(SSH2_MSG_CHANNEL_REQUEST);
250 translate(SSH2_MSG_CHANNEL_SUCCESS);
251 translate(SSH2_MSG_CHANNEL_FAILURE);
257 #define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
263 #define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
269 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
271 /* Coroutine mechanics for the sillier bits of the code */
272 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
277 #define crFinish(z) } *crLine = 0; return (z); }
278 #define crFinishV } *crLine = 0; return; }
279 #define crReturn(z) \
281 *crLine =__LINE__; return (z); case __LINE__:;\
285 *crLine=__LINE__; return; case __LINE__:;\
287 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
288 #define crStopV do{ *crLine = 0; return; }while(0)
289 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
290 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
292 typedef struct ssh_tag *Ssh;
294 extern char *x11_init(Socket *, char *, void *, void *);
295 extern void x11_close(Socket);
296 extern int x11_send(Socket, char *, int);
297 extern void *x11_invent_auth(char *, int, char *, int);
298 extern void x11_unthrottle(Socket s);
299 extern void x11_override_throttle(Socket s, int enable);
300 extern int x11_get_screen_number(char *display);
302 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
303 extern char *pfd_addforward(char *desthost, int destport, char *srcaddr,
304 int port, void *backhandle);
305 extern void pfd_close(Socket s);
306 extern int pfd_send(Socket s, char *data, int len);
307 extern void pfd_confirm(Socket s);
308 extern void pfd_unthrottle(Socket s);
309 extern void pfd_override_throttle(Socket s, int enable);
311 static void ssh2_pkt_init(Ssh, int pkt_type);
312 static void ssh2_pkt_addbool(Ssh, unsigned char value);
313 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
314 static void ssh2_pkt_addstring_start(Ssh);
315 static void ssh2_pkt_addstring_str(Ssh, char *data);
316 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
317 static void ssh2_pkt_addstring(Ssh, char *data);
318 static char *ssh2_mpint_fmt(Bignum b, int *len);
319 static void ssh2_pkt_addmp(Ssh, Bignum b);
320 static int ssh2_pkt_construct(Ssh);
321 static void ssh2_pkt_send(Ssh);
324 * Buffer management constants. There are several of these for
325 * various different purposes:
327 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
328 * on a local data stream before we throttle the whole SSH
329 * connection (in SSH1 only). Throttling the whole connection is
330 * pretty drastic so we set this high in the hope it won't
333 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
334 * on the SSH connection itself before we defensively throttle
335 * _all_ local data streams. This is pretty drastic too (though
336 * thankfully unlikely in SSH2 since the window mechanism should
337 * ensure that the server never has any need to throttle its end
338 * of the connection), so we set this high as well.
340 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
344 #define SSH1_BUFFER_LIMIT 32768
345 #define SSH_MAX_BACKLOG 32768
346 #define OUR_V2_WINSIZE 16384
348 const static struct ssh_kex *kex_algs[] = {
349 &ssh_diffiehellman_gex,
353 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
355 static void *nullmac_make_context(void)
359 static void nullmac_free_context(void *handle)
362 static void nullmac_key(void *handle, unsigned char *key)
365 static void nullmac_generate(void *handle, unsigned char *blk, int len,
369 static int nullmac_verify(void *handle, unsigned char *blk, int len,
374 const static struct ssh_mac ssh_mac_none = {
375 nullmac_make_context, nullmac_free_context, nullmac_key,
376 nullmac_generate, nullmac_verify, "none", 0
378 const static struct ssh_mac *macs[] = {
379 &ssh_sha1, &ssh_md5, &ssh_mac_none
381 const static struct ssh_mac *buggymacs[] = {
382 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
385 static void *ssh_comp_none_init(void)
389 static void ssh_comp_none_cleanup(void *handle)
392 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
393 unsigned char **outblock, int *outlen)
397 static int ssh_comp_none_disable(void *handle)
401 const static struct ssh_compress ssh_comp_none = {
403 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
404 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
405 ssh_comp_none_disable, NULL
407 extern const struct ssh_compress ssh_zlib;
408 const static struct ssh_compress *compressions[] = {
409 &ssh_zlib, &ssh_comp_none
412 enum { /* channel types */
417 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
421 * 2-3-4 tree storing channels.
424 Ssh ssh; /* pointer back to main context */
425 unsigned remoteid, localid;
428 * In SSH1, this value contains four bits:
430 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
431 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
432 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
433 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
435 * A channel is completely finished with when all four bits are set.
439 struct ssh1_data_channel {
442 struct ssh2_data_channel {
444 unsigned remwindow, remmaxpkt;
449 struct ssh_agent_channel {
450 unsigned char *message;
451 unsigned char msglen[4];
452 int lensofar, totallen;
454 struct ssh_x11_channel {
457 struct ssh_pfd_channel {
464 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
465 * 2 use this structure in different ways, reflecting SSH 2's
466 * altogether saner approach to port forwarding.
468 * In SSH 1, you arrange a remote forwarding by sending the server
469 * the remote port number, and the local destination host:port.
470 * When a connection comes in, the server sends you back that
471 * host:port pair, and you connect to it. This is a ready-made
472 * security hole if you're not on the ball: a malicious server
473 * could send you back _any_ host:port pair, so if you trustingly
474 * connect to the address it gives you then you've just opened the
475 * entire inside of your corporate network just by connecting
476 * through it to a dodgy SSH server. Hence, we must store a list of
477 * host:port pairs we _are_ trying to forward to, and reject a
478 * connection request from the server if it's not in the list.
480 * In SSH 2, each side of the connection minds its own business and
481 * doesn't send unnecessary information to the other. You arrange a
482 * remote forwarding by sending the server just the remote port
483 * number. When a connection comes in, the server tells you which
484 * of its ports was connected to; and _you_ have to remember what
485 * local host:port pair went with that port number.
487 * Hence: in SSH 1 this structure stores host:port pairs we intend
488 * to allow connections to, and is indexed by those host:port
489 * pairs. In SSH 2 it stores a mapping from source port to
490 * destination host:port pair, and is indexed by source port.
492 struct ssh_rportfwd {
493 unsigned sport, dport;
506 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
507 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
508 static void ssh_size(void *handle, int width, int height);
509 static void ssh_special(void *handle, Telnet_Special);
510 static int ssh2_try_send(struct ssh_channel *c);
511 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
512 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
513 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
514 static int ssh_sendbuffer(void *handle);
516 struct rdpkt1_state_tag {
517 long len, pad, biglen, to_read;
518 unsigned long realcrc, gotcrc;
524 struct rdpkt2_state_tag {
525 long len, pad, payload, packetlen, maclen;
528 unsigned long incoming_sequence;
532 const struct plug_function_table *fn;
533 /* the above field _must_ be first in the structure */
535 SHA_State exhash, exhashbase;
542 unsigned char session_key[32];
544 int v1_remote_protoflags;
545 int v1_local_protoflags;
546 int agentfwd_enabled;
549 const struct ssh_cipher *cipher;
552 const struct ssh2_cipher *cscipher, *sccipher;
553 void *cs_cipher_ctx, *sc_cipher_ctx;
554 const struct ssh_mac *csmac, *scmac;
555 void *cs_mac_ctx, *sc_mac_ctx;
556 const struct ssh_compress *cscomp, *sccomp;
557 void *cs_comp_ctx, *sc_comp_ctx;
558 const struct ssh_kex *kex;
559 const struct ssh_signkey *hostkey;
560 unsigned char v2_session_id[20];
566 int echoing, editing;
570 int term_width, term_height;
572 tree234 *channels; /* indexed by local id */
573 struct ssh_channel *mainchan; /* primary session channel */
580 SSH_STATE_BEFORE_SIZE,
586 int size_needed, eof_needed;
589 struct Packet pktout;
590 unsigned char *deferred_send_data;
591 int deferred_len, deferred_size;
594 * Gross hack: pscp will try to start SFTP but fall back to
595 * scp1 if that fails. This variable is the means by which
596 * scp.c can reach into the SSH code and find out which one it
602 * Used for username and password input.
604 char *userpass_input_buffer;
605 int userpass_input_buflen;
606 int userpass_input_bufpos;
607 int userpass_input_echo;
609 char *portfwd_strptr;
615 int v1_throttle_count;
618 int v1_stdout_throttling;
619 int v2_outgoing_sequence;
621 int ssh1_rdpkt_crstate;
622 int ssh2_rdpkt_crstate;
623 int do_ssh_init_crstate;
624 int ssh_gotdata_crstate;
625 int ssh1_protocol_crstate;
626 int do_ssh1_login_crstate;
627 int do_ssh2_transport_crstate;
628 int do_ssh2_authconn_crstate;
630 void *do_ssh_init_state;
631 void *do_ssh1_login_state;
632 void *do_ssh2_transport_state;
633 void *do_ssh2_authconn_state;
635 struct rdpkt1_state_tag rdpkt1_state;
636 struct rdpkt2_state_tag rdpkt2_state;
638 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
639 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
642 #define logevent(s) logevent(ssh->frontend, s)
644 /* logevent, only printf-formatted. */
645 void logeventf(Ssh ssh, char *fmt, ...)
651 buf = dupvprintf(fmt, ap);
657 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
658 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
659 logeventf msg, connection_fatal msg )
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((ssh,"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((ssh,"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];
864 log_packet(ssh->logctx,
865 PKT_INCOMING, ssh->pktin.type,
866 ssh1_pkt_type(ssh->pktin.type),
867 ssh->pktin.body, ssh->pktin.length);
869 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
870 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
871 ssh->pktin.type == SSH1_MSG_DEBUG ||
872 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
873 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
874 long stringlen = GET_32BIT(ssh->pktin.body);
875 if (stringlen + 4 != ssh->pktin.length) {
876 bombout((ssh,"Received data packet with bogus string length"));
881 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
882 /* log debug message */
884 int stringlen = GET_32BIT(ssh->pktin.body);
885 strcpy(buf, "Remote debug message: ");
888 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
889 buf[8 + stringlen] = '\0';
892 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
897 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
898 /* log reason code in disconnect message */
900 unsigned msglen = GET_32BIT(ssh->pktin.body);
902 strcpy(buf, "Remote sent disconnect: ");
903 nowlen = strlen(buf);
904 if (msglen > sizeof(buf) - nowlen - 1)
905 msglen = sizeof(buf) - nowlen - 1;
906 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
907 buf[nowlen + msglen] = '\0';
908 /* logevent(buf); (this is now done within the bombout macro) */
909 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
916 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
918 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
920 crBegin(ssh->ssh2_rdpkt_crstate);
924 ssh->pktin.length = 0;
926 st->cipherblk = ssh->sccipher->blksize;
929 if (st->cipherblk < 8)
932 if (ssh->pktin.maxlen < st->cipherblk) {
933 ssh->pktin.maxlen = st->cipherblk;
934 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
938 * Acquire and decrypt the first block of the packet. This will
939 * contain the length and padding details.
941 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
942 while ((*datalen) == 0)
943 crReturn(st->cipherblk - st->i);
944 ssh->pktin.data[st->i] = *(*data)++;
949 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
950 ssh->pktin.data, st->cipherblk);
953 * Now get the length and padding figures.
955 st->len = GET_32BIT(ssh->pktin.data);
956 st->pad = ssh->pktin.data[4];
959 * _Completely_ silly lengths should be stomped on before they
960 * do us any more damage.
962 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
963 bombout((ssh,"Incoming packet was garbled on decryption"));
968 * This enables us to deduce the payload length.
970 st->payload = st->len - st->pad - 1;
972 ssh->pktin.length = st->payload + 5;
975 * So now we can work out the total packet length.
977 st->packetlen = st->len + 4;
978 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
981 * Adjust memory allocation if packet is too big.
983 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
984 ssh->pktin.maxlen = st->packetlen + st->maclen;
985 ssh->pktin.data = srealloc(ssh->pktin.data,
986 ssh->pktin.maxlen + APIEXTRA);
990 * Read and decrypt the remainder of the packet.
992 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
994 while ((*datalen) == 0)
995 crReturn(st->packetlen + st->maclen - st->i);
996 ssh->pktin.data[st->i] = *(*data)++;
999 /* Decrypt everything _except_ the MAC. */
1001 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1002 ssh->pktin.data + st->cipherblk,
1003 st->packetlen - st->cipherblk);
1009 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1010 st->incoming_sequence)) {
1011 bombout((ssh,"Incorrect MAC received on packet"));
1014 st->incoming_sequence++; /* whether or not we MACed */
1017 * Decompress packet payload.
1020 unsigned char *newpayload;
1023 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1024 ssh->pktin.data + 5, ssh->pktin.length - 5,
1025 &newpayload, &newlen)) {
1026 if (ssh->pktin.maxlen < newlen + 5) {
1027 ssh->pktin.maxlen = newlen + 5;
1028 ssh->pktin.data = srealloc(ssh->pktin.data,
1029 ssh->pktin.maxlen + APIEXTRA);
1031 ssh->pktin.length = 5 + newlen;
1032 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1037 ssh->pktin.savedpos = 6;
1038 ssh->pktin.type = ssh->pktin.data[5];
1041 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1042 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1043 ssh->pktin.data+6, ssh->pktin.length-6);
1045 switch (ssh->pktin.type) {
1047 * These packets we must handle instantly.
1049 case SSH2_MSG_DISCONNECT:
1051 /* log reason code in disconnect message */
1054 int reason = GET_32BIT(ssh->pktin.data + 6);
1055 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1057 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1058 buf = dupprintf("Received disconnect message (%s)",
1059 ssh2_disconnect_reasons[reason]);
1061 buf = dupprintf("Received disconnect message (unknown"
1062 " type %d)", reason);
1066 buf = dupprintf("Disconnection message text: %n%.*s",
1067 &nowlen, msglen, ssh->pktin.data + 14);
1069 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1071 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1072 ssh2_disconnect_reasons[reason] : "unknown",
1078 case SSH2_MSG_IGNORE:
1080 case SSH2_MSG_DEBUG:
1082 /* log the debug message */
1084 /* int display = ssh->pktin.body[6]; */
1085 int stringlen = GET_32BIT(ssh->pktin.data+7);
1087 strcpy(buf, "Remote debug message: ");
1088 prefix = strlen(buf);
1089 if (stringlen > (int)(sizeof(buf)-prefix-1))
1090 stringlen = sizeof(buf)-prefix-1;
1091 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1092 buf[prefix + stringlen] = '\0';
1095 goto next_packet; /* FIXME: print the debug message */
1098 * These packets we need do nothing about here.
1100 case SSH2_MSG_UNIMPLEMENTED:
1101 case SSH2_MSG_SERVICE_REQUEST:
1102 case SSH2_MSG_SERVICE_ACCEPT:
1103 case SSH2_MSG_KEXINIT:
1104 case SSH2_MSG_NEWKEYS:
1105 case SSH2_MSG_KEXDH_INIT:
1106 case SSH2_MSG_KEXDH_REPLY:
1107 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1108 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1109 case SSH2_MSG_KEX_DH_GEX_INIT:
1110 case SSH2_MSG_KEX_DH_GEX_REPLY:
1111 case SSH2_MSG_USERAUTH_REQUEST:
1112 case SSH2_MSG_USERAUTH_FAILURE:
1113 case SSH2_MSG_USERAUTH_SUCCESS:
1114 case SSH2_MSG_USERAUTH_BANNER:
1115 case SSH2_MSG_USERAUTH_PK_OK:
1116 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1117 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1118 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1119 case SSH2_MSG_GLOBAL_REQUEST:
1120 case SSH2_MSG_REQUEST_SUCCESS:
1121 case SSH2_MSG_REQUEST_FAILURE:
1122 case SSH2_MSG_CHANNEL_OPEN:
1123 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1124 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1125 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1126 case SSH2_MSG_CHANNEL_DATA:
1127 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1128 case SSH2_MSG_CHANNEL_EOF:
1129 case SSH2_MSG_CHANNEL_CLOSE:
1130 case SSH2_MSG_CHANNEL_REQUEST:
1131 case SSH2_MSG_CHANNEL_SUCCESS:
1132 case SSH2_MSG_CHANNEL_FAILURE:
1136 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1139 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1140 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1148 static void ssh1_pktout_size(Ssh ssh, int len)
1152 len += 5; /* type and CRC */
1153 pad = 8 - (len % 8);
1156 ssh->pktout.length = len - 5;
1157 if (ssh->pktout.maxlen < biglen) {
1158 ssh->pktout.maxlen = biglen;
1160 /* Allocate enough buffer space for extra block
1161 * for MS CryptEncrypt() */
1162 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1164 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1167 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1170 static void s_wrpkt_start(Ssh ssh, int type, int len)
1172 ssh1_pktout_size(ssh, len);
1173 ssh->pktout.type = type;
1176 static int s_wrpkt_prepare(Ssh ssh)
1178 int pad, len, biglen, i;
1181 ssh->pktout.body[-1] = ssh->pktout.type;
1184 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1185 ssh1_pkt_type(ssh->pktout.type),
1186 ssh->pktout.body, ssh->pktout.length);
1188 if (ssh->v1_compressing) {
1189 unsigned char *compblk;
1191 zlib_compress_block(ssh->cs_comp_ctx,
1192 ssh->pktout.body - 1, ssh->pktout.length + 1,
1193 &compblk, &complen);
1194 ssh1_pktout_size(ssh, complen - 1);
1195 memcpy(ssh->pktout.body - 1, compblk, complen);
1199 len = ssh->pktout.length + 5; /* type and CRC */
1200 pad = 8 - (len % 8);
1203 for (i = 0; i < pad; i++)
1204 ssh->pktout.data[i + 4] = random_byte();
1205 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1206 PUT_32BIT(ssh->pktout.data + biglen, crc);
1207 PUT_32BIT(ssh->pktout.data, len);
1210 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1215 static void s_wrpkt(Ssh ssh)
1218 len = s_wrpkt_prepare(ssh);
1219 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1220 if (backlog > SSH_MAX_BACKLOG)
1221 ssh_throttle_all(ssh, 1, backlog);
1224 static void s_wrpkt_defer(Ssh ssh)
1227 len = s_wrpkt_prepare(ssh);
1228 if (ssh->deferred_len + len > ssh->deferred_size) {
1229 ssh->deferred_size = ssh->deferred_len + len + 128;
1230 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1231 ssh->deferred_size);
1233 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1234 ssh->deferred_len += len;
1238 * Construct a packet with the specified contents.
1240 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1242 unsigned char *p, *argp, argchar;
1243 unsigned long argint;
1244 int pktlen, argtype, arglen;
1248 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1251 (void) va_arg(ap1, int);
1255 (void) va_arg(ap1, int);
1259 (void) va_arg(ap1, unsigned char *);
1260 arglen = va_arg(ap1, int);
1264 argp = va_arg(ap1, unsigned char *);
1265 arglen = strlen(argp);
1266 pktlen += 4 + arglen;
1269 bn = va_arg(ap1, Bignum);
1270 pktlen += ssh1_bignum_length(bn);
1277 s_wrpkt_start(ssh, pkttype, pktlen);
1278 p = ssh->pktout.body;
1280 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1283 argint = va_arg(ap2, int);
1284 PUT_32BIT(p, argint);
1288 argchar = (unsigned char) va_arg(ap2, int);
1293 argp = va_arg(ap2, unsigned char *);
1294 arglen = va_arg(ap2, int);
1295 memcpy(p, argp, arglen);
1299 argp = va_arg(ap2, unsigned char *);
1300 arglen = strlen(argp);
1301 PUT_32BIT(p, arglen);
1302 memcpy(p + 4, argp, arglen);
1306 bn = va_arg(ap2, Bignum);
1307 p += ssh1_write_bignum(p, bn);
1313 static void send_packet(Ssh ssh, int pkttype, ...)
1316 va_start(ap1, pkttype);
1317 va_start(ap2, pkttype);
1318 construct_packet(ssh, pkttype, ap1, ap2);
1322 static void defer_packet(Ssh ssh, int pkttype, ...)
1325 va_start(ap1, pkttype);
1326 va_start(ap2, pkttype);
1327 construct_packet(ssh, pkttype, ap1, ap2);
1331 static int ssh_versioncmp(char *a, char *b)
1334 unsigned long av, bv;
1336 av = strtoul(a, &ae, 10);
1337 bv = strtoul(b, &be, 10);
1339 return (av < bv ? -1 : +1);
1344 av = strtoul(ae, &ae, 10);
1345 bv = strtoul(be, &be, 10);
1347 return (av < bv ? -1 : +1);
1352 * Utility routines for putting an SSH-protocol `string' and
1353 * `uint32' into a SHA state.
1356 static void sha_string(SHA_State * s, void *str, int len)
1358 unsigned char lenblk[4];
1359 PUT_32BIT(lenblk, len);
1360 SHA_Bytes(s, lenblk, 4);
1361 SHA_Bytes(s, str, len);
1364 static void sha_uint32(SHA_State * s, unsigned i)
1366 unsigned char intblk[4];
1367 PUT_32BIT(intblk, i);
1368 SHA_Bytes(s, intblk, 4);
1372 * SSH2 packet construction functions.
1374 static void ssh2_pkt_ensure(Ssh ssh, int length)
1376 if (ssh->pktout.maxlen < length) {
1377 ssh->pktout.maxlen = length + 256;
1378 ssh->pktout.data = srealloc(ssh->pktout.data,
1379 ssh->pktout.maxlen + APIEXTRA);
1380 if (!ssh->pktout.data)
1381 fatalbox("Out of memory");
1384 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1386 ssh->pktout.length += len;
1387 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1388 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1390 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1392 ssh2_pkt_adddata(ssh, &byte, 1);
1394 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1396 ssh->pktout.length = 5;
1397 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1399 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1401 ssh2_pkt_adddata(ssh, &value, 1);
1403 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1406 PUT_32BIT(x, value);
1407 ssh2_pkt_adddata(ssh, x, 4);
1409 static void ssh2_pkt_addstring_start(Ssh ssh)
1411 ssh2_pkt_adduint32(ssh, 0);
1412 ssh->pktout.savedpos = ssh->pktout.length;
1414 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1416 ssh2_pkt_adddata(ssh, data, strlen(data));
1417 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1418 ssh->pktout.length - ssh->pktout.savedpos);
1420 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1422 ssh2_pkt_adddata(ssh, data, len);
1423 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1424 ssh->pktout.length - ssh->pktout.savedpos);
1426 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1428 ssh2_pkt_addstring_start(ssh);
1429 ssh2_pkt_addstring_str(ssh, data);
1431 static char *ssh2_mpint_fmt(Bignum b, int *len)
1434 int i, n = (bignum_bitcount(b) + 7) / 8;
1437 fatalbox("out of memory");
1439 for (i = 1; i <= n; i++)
1440 p[i] = bignum_byte(b, n - i);
1442 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1444 memmove(p, p + i, n + 1 - i);
1448 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1452 p = ssh2_mpint_fmt(b, &len);
1453 ssh2_pkt_addstring_start(ssh);
1454 ssh2_pkt_addstring_data(ssh, p, len);
1459 * Construct an SSH2 final-form packet: compress it, encrypt it,
1460 * put the MAC on it. Final packet, ready to be sent, is stored in
1461 * ssh->pktout.data. Total length is returned.
1463 static int ssh2_pkt_construct(Ssh ssh)
1465 int cipherblk, maclen, padding, i;
1468 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1469 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1470 ssh->pktout.data + 6, ssh->pktout.length - 6);
1473 * Compress packet payload.
1476 unsigned char *newpayload;
1479 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1480 ssh->pktout.length - 5,
1481 &newpayload, &newlen)) {
1482 ssh->pktout.length = 5;
1483 ssh2_pkt_adddata(ssh, newpayload, newlen);
1489 * Add padding. At least four bytes, and must also bring total
1490 * length (minus MAC) up to a multiple of the block size.
1492 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1493 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1496 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1497 maclen = ssh->csmac ? ssh->csmac->len : 0;
1498 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1499 ssh->pktout.data[4] = padding;
1500 for (i = 0; i < padding; i++)
1501 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1502 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1504 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1505 ssh->pktout.length + padding,
1506 ssh->v2_outgoing_sequence);
1507 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1510 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1511 ssh->pktout.data, ssh->pktout.length + padding);
1513 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1514 return ssh->pktout.length + padding + maclen;
1518 * Construct and send an SSH2 packet immediately.
1520 static void ssh2_pkt_send(Ssh ssh)
1524 len = ssh2_pkt_construct(ssh);
1525 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1526 if (backlog > SSH_MAX_BACKLOG)
1527 ssh_throttle_all(ssh, 1, backlog);
1531 * Construct an SSH2 packet and add it to a deferred data block.
1532 * Useful for sending multiple packets in a single sk_write() call,
1533 * to prevent a traffic-analysing listener from being able to work
1534 * out the length of any particular packet (such as the password
1537 * Note that because SSH2 sequence-numbers its packets, this can
1538 * NOT be used as an m4-style `defer' allowing packets to be
1539 * constructed in one order and sent in another.
1541 static void ssh2_pkt_defer(Ssh ssh)
1543 int len = ssh2_pkt_construct(ssh);
1544 if (ssh->deferred_len + len > ssh->deferred_size) {
1545 ssh->deferred_size = ssh->deferred_len + len + 128;
1546 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1547 ssh->deferred_size);
1549 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1550 ssh->deferred_len += len;
1554 * Send the whole deferred data block constructed by
1555 * ssh2_pkt_defer() or SSH1's defer_packet().
1557 static void ssh_pkt_defersend(Ssh ssh)
1560 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1561 ssh->deferred_len = ssh->deferred_size = 0;
1562 sfree(ssh->deferred_send_data);
1563 ssh->deferred_send_data = NULL;
1564 if (backlog > SSH_MAX_BACKLOG)
1565 ssh_throttle_all(ssh, 1, backlog);
1569 void bndebug(char *string, Bignum b)
1573 p = ssh2_mpint_fmt(b, &len);
1574 debug(("%s", string));
1575 for (i = 0; i < len; i++)
1576 debug((" %02x", p[i]));
1582 static void sha_mpint(SHA_State * s, Bignum b)
1586 p = ssh2_mpint_fmt(b, &len);
1587 sha_string(s, p, len);
1592 * SSH2 packet decode functions.
1594 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1596 unsigned long value;
1597 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1598 return 0; /* arrgh, no way to decline (FIXME?) */
1599 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1600 ssh->pktin.savedpos += 4;
1603 static int ssh2_pkt_getbool(Ssh ssh)
1605 unsigned long value;
1606 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1607 return 0; /* arrgh, no way to decline (FIXME?) */
1608 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1609 ssh->pktin.savedpos++;
1612 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1617 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1619 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1623 ssh->pktin.savedpos += 4;
1624 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1626 *p = ssh->pktin.data + ssh->pktin.savedpos;
1627 ssh->pktin.savedpos += *length;
1629 static Bignum ssh2_pkt_getmp(Ssh ssh)
1635 ssh2_pkt_getstring(ssh, &p, &length);
1639 bombout((ssh,"internal error: Can't handle negative mpints"));
1642 b = bignum_from_bytes(p, length);
1647 * Helper function to add an SSH2 signature blob to a packet.
1648 * Expects to be shown the public key blob as well as the signature
1649 * blob. Normally works just like ssh2_pkt_addstring, but will
1650 * fiddle with the signature packet if necessary for
1651 * BUG_SSH2_RSA_PADDING.
1653 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1654 void *sigblob_v, int sigblob_len)
1656 unsigned char *pkblob = (unsigned char *)pkblob_v;
1657 unsigned char *sigblob = (unsigned char *)sigblob_v;
1659 /* dmemdump(pkblob, pkblob_len); */
1660 /* dmemdump(sigblob, sigblob_len); */
1663 * See if this is in fact an ssh-rsa signature and a buggy
1664 * server; otherwise we can just do this the easy way.
1666 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1667 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1668 int pos, len, siglen;
1671 * Find the byte length of the modulus.
1674 pos = 4+7; /* skip over "ssh-rsa" */
1675 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1676 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1677 pos += 4; /* find modulus itself */
1678 while (len > 0 && pkblob[pos] == 0)
1680 /* debug(("modulus length is %d\n", len)); */
1683 * Now find the signature integer.
1685 pos = 4+7; /* skip over "ssh-rsa" */
1686 siglen = GET_32BIT(sigblob+pos);
1687 /* debug(("signature length is %d\n", siglen)); */
1689 if (len != siglen) {
1690 unsigned char newlen[4];
1691 ssh2_pkt_addstring_start(ssh);
1692 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1693 /* dmemdump(sigblob, pos); */
1694 pos += 4; /* point to start of actual sig */
1695 PUT_32BIT(newlen, len);
1696 ssh2_pkt_addstring_data(ssh, newlen, 4);
1697 /* dmemdump(newlen, 4); */
1699 while (len-- > siglen) {
1700 ssh2_pkt_addstring_data(ssh, newlen, 1);
1701 /* dmemdump(newlen, 1); */
1703 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1704 /* dmemdump(sigblob+pos, siglen); */
1708 /* Otherwise fall through and do it the easy way. */
1711 ssh2_pkt_addstring_start(ssh);
1712 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1716 * Examine the remote side's version string and compare it against
1717 * a list of known buggy implementations.
1719 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1721 char *imp; /* pointer to implementation part */
1723 imp += strcspn(imp, "-");
1725 imp += strcspn(imp, "-");
1728 ssh->remote_bugs = 0;
1730 if (cfg.sshbug_ignore1 == BUG_ON ||
1731 (cfg.sshbug_ignore1 == BUG_AUTO &&
1732 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1733 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1734 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1736 * These versions don't support SSH1_MSG_IGNORE, so we have
1737 * to use a different defence against password length
1740 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1741 logevent("We believe remote version has SSH1 ignore bug");
1744 if (cfg.sshbug_plainpw1 == BUG_ON ||
1745 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1746 (!strcmp(imp, "Cisco-1.25")))) {
1748 * These versions need a plain password sent; they can't
1749 * handle having a null and a random length of data after
1752 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1753 logevent("We believe remote version needs a plain SSH1 password");
1756 if (cfg.sshbug_rsa1 == BUG_ON ||
1757 (cfg.sshbug_rsa1 == BUG_AUTO &&
1758 (!strcmp(imp, "Cisco-1.25")))) {
1760 * These versions apparently have no clue whatever about
1761 * RSA authentication and will panic and die if they see
1762 * an AUTH_RSA message.
1764 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1765 logevent("We believe remote version can't handle RSA authentication");
1768 if (cfg.sshbug_hmac2 == BUG_ON ||
1769 (cfg.sshbug_hmac2 == BUG_AUTO &&
1770 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1771 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1772 wc_match("2.1 *", imp)))) {
1774 * These versions have the HMAC bug.
1776 ssh->remote_bugs |= BUG_SSH2_HMAC;
1777 logevent("We believe remote version has SSH2 HMAC bug");
1780 if (cfg.sshbug_derivekey2 == BUG_ON ||
1781 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1782 (wc_match("2.0.0*", imp) || wc_match("2.0.1[01]*", imp) ))) {
1784 * These versions have the key-derivation bug (failing to
1785 * include the literal shared secret in the hashes that
1786 * generate the keys).
1788 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1789 logevent("We believe remote version has SSH2 key-derivation bug");
1792 if (cfg.sshbug_rsapad2 == BUG_ON ||
1793 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1794 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1795 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1797 * These versions have the SSH2 RSA padding bug.
1799 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1800 logevent("We believe remote version has SSH2 RSA padding bug");
1803 if (cfg.sshbug_dhgex2 == BUG_ON) {
1805 * User specified the SSH2 DH GEX bug.
1807 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1808 logevent("We believe remote version has SSH2 DH group exchange bug");
1812 static int do_ssh_init(Ssh ssh, unsigned char c)
1814 struct do_ssh_init_state {
1822 crState(do_ssh_init_state);
1824 crBegin(ssh->do_ssh_init_crstate);
1826 /* Search for the string "SSH-" in the input. */
1829 static const int transS[] = { 1, 2, 2, 1 };
1830 static const int transH[] = { 0, 0, 3, 0 };
1831 static const int transminus[] = { 0, 0, 0, -1 };
1833 s->i = transS[s->i];
1835 s->i = transH[s->i];
1837 s->i = transminus[s->i];
1842 crReturn(1); /* get another character */
1846 s->vstring = smalloc(s->vstrsize);
1847 strcpy(s->vstring, "SSH-");
1851 crReturn(1); /* get another char */
1852 if (s->vslen >= s->vstrsize - 1) {
1854 s->vstring = srealloc(s->vstring, s->vstrsize);
1856 s->vstring[s->vslen++] = c;
1859 s->version[s->i] = '\0';
1861 } else if (s->i < sizeof(s->version) - 1)
1862 s->version[s->i++] = c;
1863 } else if (c == '\n')
1867 ssh->agentfwd_enabled = FALSE;
1868 ssh->rdpkt2_state.incoming_sequence = 0;
1870 s->vstring[s->vslen] = 0;
1871 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1874 vlog = smalloc(20 + s->vslen);
1875 sprintf(vlog, "Server version: %s", s->vstring);
1879 ssh_detect_bugs(ssh, s->vstring);
1882 * Decide which SSH protocol version to support.
1885 /* Anything strictly below "2.0" means protocol 1 is supported. */
1886 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1887 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1888 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1890 if (cfg.sshprot == 0 && !s->proto1) {
1891 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
1894 if (cfg.sshprot == 3 && !s->proto2) {
1895 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
1899 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1903 char verstring[80], vlog[100];
1904 sprintf(verstring, "SSH-2.0-%s", sshver);
1905 SHA_Init(&ssh->exhashbase);
1907 * Hash our version string and their version string.
1909 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1910 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1911 sprintf(vlog, "We claim version: %s", verstring);
1913 strcat(verstring, "\n");
1914 logevent("Using SSH protocol version 2");
1915 sk_write(ssh->s, verstring, strlen(verstring));
1916 ssh->protocol = ssh2_protocol;
1918 ssh->s_rdpkt = ssh2_rdpkt;
1923 char verstring[80], vlog[100];
1924 sprintf(verstring, "SSH-%s-%s",
1925 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1927 sprintf(vlog, "We claim version: %s", verstring);
1929 strcat(verstring, "\n");
1931 logevent("Using SSH protocol version 1");
1932 sk_write(ssh->s, verstring, strlen(verstring));
1933 ssh->protocol = ssh1_protocol;
1935 ssh->s_rdpkt = ssh1_rdpkt;
1937 ssh->state = SSH_STATE_BEFORE_SIZE;
1944 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1946 crBegin(ssh->ssh_gotdata_crstate);
1949 * To begin with, feed the characters one by one to the
1950 * protocol initialisation / selection function do_ssh_init().
1951 * When that returns 0, we're done with the initial greeting
1952 * exchange and can move on to packet discipline.
1955 int ret; /* need not be kept across crReturn */
1957 crReturnV; /* more data please */
1958 ret = do_ssh_init(ssh, *data);
1966 * We emerge from that loop when the initial negotiation is
1967 * over and we have selected an s_rdpkt function. Now pass
1968 * everything to s_rdpkt, and then pass the resulting packets
1969 * to the proper protocol handler.
1974 while (datalen > 0) {
1975 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1976 if (ssh->state == SSH_STATE_CLOSED) {
1979 ssh->protocol(ssh, NULL, 0, 1);
1980 if (ssh->state == SSH_STATE_CLOSED) {
1990 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1993 Ssh ssh = (Ssh) plug;
1994 ssh->state = SSH_STATE_CLOSED;
2000 /* A socket error has occurred. */
2001 logevent(error_msg);
2002 connection_fatal(ssh->frontend, error_msg);
2004 /* Otherwise, the remote side closed the connection normally. */
2009 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2011 Ssh ssh = (Ssh) plug;
2012 ssh_gotdata(ssh, data, len);
2013 if (ssh->state == SSH_STATE_CLOSED) {
2023 static void ssh_sent(Plug plug, int bufsize)
2025 Ssh ssh = (Ssh) plug;
2027 * If the send backlog on the SSH socket itself clears, we
2028 * should unthrottle the whole world if it was throttled.
2030 if (bufsize < SSH_MAX_BACKLOG)
2031 ssh_throttle_all(ssh, 0, bufsize);
2035 * Connect to specified host and port.
2036 * Returns an error message, or NULL on success.
2037 * Also places the canonical host name into `realhost'. It must be
2038 * freed by the caller.
2040 static char *connect_to_host(Ssh ssh, char *host, int port,
2041 char **realhost, int nodelay)
2043 static const struct plug_function_table fn_table = {
2053 ssh->savedhost = smalloc(1 + strlen(host));
2054 if (!ssh->savedhost)
2055 fatalbox("Out of memory");
2056 strcpy(ssh->savedhost, host);
2059 port = 22; /* default ssh port */
2060 ssh->savedport = port;
2065 logeventf(ssh, "Looking up host \"%s\"", host);
2066 addr = name_lookup(host, port, realhost);
2067 if ((err = sk_addr_error(addr)))
2075 sk_getaddr(addr, addrbuf, 100);
2076 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2078 ssh->fn = &fn_table;
2079 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2080 if ((err = sk_socket_error(ssh->s))) {
2089 * Throttle or unthrottle the SSH connection.
2091 static void ssh1_throttle(Ssh ssh, int adjust)
2093 int old_count = ssh->v1_throttle_count;
2094 ssh->v1_throttle_count += adjust;
2095 assert(ssh->v1_throttle_count >= 0);
2096 if (ssh->v1_throttle_count && !old_count) {
2097 sk_set_frozen(ssh->s, 1);
2098 } else if (!ssh->v1_throttle_count && old_count) {
2099 sk_set_frozen(ssh->s, 0);
2104 * Throttle or unthrottle _all_ local data streams (for when sends
2105 * on the SSH connection itself back up).
2107 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2110 struct ssh_channel *c;
2112 if (enable == ssh->throttled_all)
2114 ssh->throttled_all = enable;
2115 ssh->overall_bufsize = bufsize;
2118 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2120 case CHAN_MAINSESSION:
2122 * This is treated separately, outside the switch.
2126 x11_override_throttle(c->u.x11.s, enable);
2129 /* Agent channels require no buffer management. */
2132 pfd_override_throttle(c->u.x11.s, enable);
2139 * Username and password input, abstracted off into routines
2140 * reusable in several places - even between SSH1 and SSH2.
2143 /* Set up a username or password input loop on a given buffer. */
2144 void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2146 ssh->userpass_input_buffer = buffer;
2147 ssh->userpass_input_buflen = buflen;
2148 ssh->userpass_input_bufpos = 0;
2149 ssh->userpass_input_echo = echo;
2153 * Process some terminal data in the course of username/password
2154 * input. Returns >0 for success (line of input returned in
2155 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2156 * for inconclusive (keep waiting for more input please).
2158 int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2163 switch (c = *in++) {
2166 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2167 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2172 if (ssh->userpass_input_bufpos > 0) {
2173 if (ssh->userpass_input_echo)
2174 c_write_str(ssh, "\b \b");
2175 ssh->userpass_input_bufpos--;
2180 while (ssh->userpass_input_bufpos > 0) {
2181 if (ssh->userpass_input_echo)
2182 c_write_str(ssh, "\b \b");
2183 ssh->userpass_input_bufpos--;
2191 if (((c >= ' ' && c <= '~') ||
2192 ((unsigned char) c >= 160))
2193 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2194 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2195 if (ssh->userpass_input_echo)
2196 c_write(ssh, &c, 1);
2205 * Handle the key exchange and user authentication phases.
2207 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2210 unsigned char cookie[8];
2211 struct RSAKey servkey, hostkey;
2212 struct MD5Context md5c;
2213 struct do_ssh1_login_state {
2215 unsigned char *rsabuf, *keystr1, *keystr2;
2216 unsigned long supported_ciphers_mask, supported_auths_mask;
2217 int tried_publickey, tried_agent;
2218 int tis_auth_refused, ccard_auth_refused;
2219 unsigned char session_id[16];
2222 void *publickey_blob;
2223 int publickey_bloblen;
2229 unsigned char request[5], *response, *p;
2238 crState(do_ssh1_login_state);
2240 crBegin(ssh->do_ssh1_login_crstate);
2245 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2246 bombout((ssh,"Public key packet not received"));
2250 logevent("Received public keys");
2252 memcpy(cookie, ssh->pktin.body, 8);
2254 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2255 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2258 * Log the host key fingerprint.
2262 logevent("Host key fingerprint is:");
2263 strcpy(logmsg, " ");
2264 hostkey.comment = NULL;
2265 rsa_fingerprint(logmsg + strlen(logmsg),
2266 sizeof(logmsg) - strlen(logmsg), &hostkey);
2270 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2271 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2272 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2274 ssh->v1_local_protoflags =
2275 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2276 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2279 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2280 MD5Update(&md5c, s->keystr1, servkey.bytes);
2281 MD5Update(&md5c, ssh->pktin.body, 8);
2282 MD5Final(s->session_id, &md5c);
2284 for (i = 0; i < 32; i++)
2285 ssh->session_key[i] = random_byte();
2287 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2289 s->rsabuf = smalloc(s->len);
2291 fatalbox("Out of memory");
2294 * Verify the host key.
2298 * First format the key into a string.
2300 int len = rsastr_len(&hostkey);
2301 char fingerprint[100];
2302 char *keystr = smalloc(len);
2304 fatalbox("Out of memory");
2305 rsastr_fmt(keystr, &hostkey);
2306 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2307 verify_ssh_host_key(ssh->frontend,
2308 ssh->savedhost, ssh->savedport, "rsa", keystr,
2313 for (i = 0; i < 32; i++) {
2314 s->rsabuf[i] = ssh->session_key[i];
2316 s->rsabuf[i] ^= s->session_id[i];
2319 if (hostkey.bytes > servkey.bytes) {
2320 rsaencrypt(s->rsabuf, 32, &servkey);
2321 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2323 rsaencrypt(s->rsabuf, 32, &hostkey);
2324 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2327 logevent("Encrypted session key");
2330 int cipher_chosen = 0, warn = 0;
2331 char *cipher_string = NULL;
2333 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2334 int next_cipher = cfg.ssh_cipherlist[i];
2335 if (next_cipher == CIPHER_WARN) {
2336 /* If/when we choose a cipher, warn about it */
2338 } else if (next_cipher == CIPHER_AES) {
2339 /* XXX Probably don't need to mention this. */
2340 logevent("AES not supported in SSH1, skipping");
2342 switch (next_cipher) {
2343 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2344 cipher_string = "3DES"; break;
2345 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2346 cipher_string = "Blowfish"; break;
2347 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2348 cipher_string = "single-DES"; break;
2350 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2354 if (!cipher_chosen) {
2355 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2356 bombout((ssh,"Server violates SSH 1 protocol by not "
2357 "supporting 3DES encryption"));
2359 /* shouldn't happen */
2360 bombout((ssh,"No supported ciphers found"));
2364 /* Warn about chosen cipher if necessary. */
2366 askcipher(ssh->frontend, cipher_string, 0);
2369 switch (s->cipher_type) {
2370 case SSH_CIPHER_3DES:
2371 logevent("Using 3DES encryption");
2373 case SSH_CIPHER_DES:
2374 logevent("Using single-DES encryption");
2376 case SSH_CIPHER_BLOWFISH:
2377 logevent("Using Blowfish encryption");
2381 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2382 PKT_CHAR, s->cipher_type,
2383 PKT_DATA, cookie, 8,
2384 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2385 PKT_DATA, s->rsabuf, s->len,
2386 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2388 logevent("Trying to enable encryption...");
2392 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2393 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2395 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2396 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2397 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2399 ssh->crcda_ctx = crcda_make_context();
2400 logevent("Installing CRC compensation attack detector");
2404 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2405 bombout((ssh,"Encryption not successfully enabled"));
2409 logevent("Successfully started encryption");
2413 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2414 if (ssh_get_line && !ssh_getline_pw_only) {
2415 if (!ssh_get_line("login as: ",
2416 s->username, sizeof(s->username), FALSE)) {
2418 * get_line failed to get a username.
2421 logevent("No username provided. Abandoning session.");
2422 ssh->state = SSH_STATE_CLOSED;
2426 int ret; /* need not be kept over crReturn */
2427 c_write_str(ssh, "login as: ");
2430 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2432 crWaitUntil(!ispkt);
2433 ret = process_userpass_input(ssh, in, inlen);
2437 c_write_str(ssh, "\r\n");
2440 strncpy(s->username, cfg.username, sizeof(s->username));
2441 s->username[sizeof(s->username)-1] = '\0';
2444 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2446 char userlog[22 + sizeof(s->username)];
2447 sprintf(userlog, "Sent username \"%s\"", s->username);
2449 if (flags & FLAG_INTERACTIVE &&
2450 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2451 strcat(userlog, "\r\n");
2452 c_write_str(ssh, userlog);
2459 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2460 /* We must not attempt PK auth. Pretend we've already tried it. */
2461 s->tried_publickey = s->tried_agent = 1;
2463 s->tried_publickey = s->tried_agent = 0;
2465 s->tis_auth_refused = s->ccard_auth_refused = 0;
2466 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2468 if (!rsakey_pubblob(cfg.keyfile,
2469 &s->publickey_blob, &s->publickey_bloblen))
2470 s->publickey_blob = NULL;
2472 s->publickey_blob = NULL;
2474 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2475 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2477 if (agent_exists() && !s->tried_agent) {
2479 * Attempt RSA authentication using Pageant.
2485 logevent("Pageant is running. Requesting keys.");
2487 /* Request the keys held by the agent. */
2488 PUT_32BIT(s->request, 1);
2489 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2490 agent_query(s->request, 5, &r, &s->responselen);
2491 s->response = (unsigned char *) r;
2492 if (s->response && s->responselen >= 5 &&
2493 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2494 s->p = s->response + 5;
2495 s->nkeys = GET_32BIT(s->p);
2499 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2502 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2505 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2508 if (s->publickey_blob &&
2509 !memcmp(s->p, s->publickey_blob,
2510 s->publickey_bloblen)) {
2511 logevent("This key matches configured key file");
2512 s->tried_publickey = 1;
2515 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2516 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2517 s->commentlen = GET_32BIT(s->p);
2520 s->p += s->commentlen;
2521 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2522 PKT_BIGNUM, s->key.modulus, PKT_END);
2524 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2525 logevent("Key refused");
2528 logevent("Received RSA challenge");
2529 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2531 char *agentreq, *q, *ret;
2534 len = 1 + 4; /* message type, bit count */
2535 len += ssh1_bignum_length(s->key.exponent);
2536 len += ssh1_bignum_length(s->key.modulus);
2537 len += ssh1_bignum_length(s->challenge);
2538 len += 16; /* session id */
2539 len += 4; /* response format */
2540 agentreq = smalloc(4 + len);
2541 PUT_32BIT(agentreq, len);
2543 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2544 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2546 q += ssh1_write_bignum(q, s->key.exponent);
2547 q += ssh1_write_bignum(q, s->key.modulus);
2548 q += ssh1_write_bignum(q, s->challenge);
2549 memcpy(q, s->session_id, 16);
2551 PUT_32BIT(q, 1); /* response format */
2552 agent_query(agentreq, len + 4, &vret, &retlen);
2556 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2557 logevent("Sending Pageant's response");
2558 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2559 PKT_DATA, ret + 5, 16,
2563 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2565 ("Pageant's response accepted");
2566 if (flags & FLAG_VERBOSE) {
2567 c_write_str(ssh, "Authenticated using"
2569 c_write(ssh, s->commentp,
2571 c_write_str(ssh, "\" from agent\r\n");
2576 ("Pageant's response not accepted");
2579 ("Pageant failed to answer challenge");
2583 logevent("No reply received from Pageant");
2586 freebn(s->key.exponent);
2587 freebn(s->key.modulus);
2588 freebn(s->challenge);
2596 if (*cfg.keyfile && !s->tried_publickey)
2597 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2599 if (cfg.try_tis_auth &&
2600 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2601 !s->tis_auth_refused) {
2602 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2603 logevent("Requested TIS authentication");
2604 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2606 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2607 logevent("TIS authentication declined");
2608 if (flags & FLAG_INTERACTIVE)
2609 c_write_str(ssh, "TIS authentication refused.\r\n");
2610 s->tis_auth_refused = 1;
2613 int challengelen = GET_32BIT(ssh->pktin.body);
2614 logevent("Received TIS challenge");
2615 if (challengelen > sizeof(s->prompt) - 1)
2616 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2617 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2618 /* Prompt heuristic comes from OpenSSH */
2619 strncpy(s->prompt + challengelen,
2620 memchr(s->prompt, '\n', challengelen) ?
2621 "": "\r\nResponse: ",
2622 (sizeof s->prompt) - challengelen);
2623 s->prompt[(sizeof s->prompt) - 1] = '\0';
2626 if (cfg.try_tis_auth &&
2627 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2628 !s->ccard_auth_refused) {
2629 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2630 logevent("Requested CryptoCard authentication");
2631 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2633 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2634 logevent("CryptoCard authentication declined");
2635 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2636 s->ccard_auth_refused = 1;
2639 int challengelen = GET_32BIT(ssh->pktin.body);
2640 logevent("Received CryptoCard challenge");
2641 if (challengelen > sizeof(s->prompt) - 1)
2642 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2643 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2644 strncpy(s->prompt + challengelen,
2645 memchr(s->prompt, '\n', challengelen) ?
2646 "" : "\r\nResponse: ",
2647 sizeof(s->prompt) - challengelen);
2648 s->prompt[sizeof(s->prompt) - 1] = '\0';
2651 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2652 sprintf(s->prompt, "%.90s@%.90s's password: ",
2653 s->username, ssh->savedhost);
2655 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2656 char *comment = NULL;
2659 if (flags & FLAG_VERBOSE)
2660 c_write_str(ssh, "Trying public key authentication.\r\n");
2661 logeventf(ssh, "Trying public key \"%s\"", cfg.keyfile);
2662 type = key_type(cfg.keyfile);
2663 if (type != SSH_KEYTYPE_SSH1) {
2664 sprintf(msgbuf, "Key is of wrong type (%s)",
2665 key_type_to_str(type));
2667 c_write_str(ssh, msgbuf);
2668 c_write_str(ssh, "\r\n");
2669 s->tried_publickey = 1;
2672 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2673 if (flags & FLAG_VERBOSE)
2674 c_write_str(ssh, "No passphrase required.\r\n");
2677 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2682 * Show password prompt, having first obtained it via a TIS
2683 * or CryptoCard exchange if we're doing TIS or CryptoCard
2687 if (!ssh_get_line(s->prompt, s->password,
2688 sizeof(s->password), TRUE)) {
2690 * get_line failed to get a password (for example
2691 * because one was supplied on the command line
2692 * which has already failed to work). Terminate.
2694 send_packet(ssh, SSH1_MSG_DISCONNECT,
2695 PKT_STR, "No more passwords available to try",
2697 logevent("Unable to authenticate");
2698 connection_fatal(ssh->frontend, "Unable to authenticate");
2699 ssh->state = SSH_STATE_CLOSED;
2703 /* Prompt may have come from server. We've munged it a bit, so
2704 * we know it to be zero-terminated at least once. */
2705 int ret; /* need not be saved over crReturn */
2706 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2709 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2711 crWaitUntil(!ispkt);
2712 ret = process_userpass_input(ssh, in, inlen);
2716 c_write_str(ssh, "\r\n");
2720 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2722 * Try public key authentication with the specified
2725 s->tried_publickey = 1;
2728 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2730 c_write_str(ssh, "Couldn't load private key from ");
2731 c_write_str(ssh, cfg.keyfile);
2732 c_write_str(ssh, ".\r\n");
2733 continue; /* go and try password */
2736 c_write_str(ssh, "Wrong passphrase.\r\n");
2737 s->tried_publickey = 0;
2738 continue; /* try again */
2743 * Send a public key attempt.
2745 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2746 PKT_BIGNUM, s->key.modulus, PKT_END);
2749 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2750 c_write_str(ssh, "Server refused our public key.\r\n");
2751 continue; /* go and try password */
2753 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2754 bombout((ssh,"Bizarre response to offer of public key"));
2760 unsigned char buffer[32];
2761 Bignum challenge, response;
2763 ssh1_read_bignum(ssh->pktin.body, &challenge);
2764 response = rsadecrypt(challenge, &s->key);
2765 freebn(s->key.private_exponent);/* burn the evidence */
2767 for (i = 0; i < 32; i++) {
2768 buffer[i] = bignum_byte(response, 31 - i);
2772 MD5Update(&md5c, buffer, 32);
2773 MD5Update(&md5c, s->session_id, 16);
2774 MD5Final(buffer, &md5c);
2776 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2777 PKT_DATA, buffer, 16, PKT_END);
2784 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2785 if (flags & FLAG_VERBOSE)
2786 c_write_str(ssh, "Failed to authenticate with"
2787 " our public key.\r\n");
2788 continue; /* go and try password */
2789 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2790 bombout((ssh,"Bizarre response to RSA authentication response"));
2794 break; /* we're through! */
2796 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2798 * Defence against traffic analysis: we send a
2799 * whole bunch of packets containing strings of
2800 * different lengths. One of these strings is the
2801 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2802 * The others are all random data in
2803 * SSH1_MSG_IGNORE packets. This way a passive
2804 * listener can't tell which is the password, and
2805 * hence can't deduce the password length.
2807 * Anybody with a password length greater than 16
2808 * bytes is going to have enough entropy in their
2809 * password that a listener won't find it _that_
2810 * much help to know how long it is. So what we'll
2813 * - if password length < 16, we send 15 packets
2814 * containing string lengths 1 through 15
2816 * - otherwise, we let N be the nearest multiple
2817 * of 8 below the password length, and send 8
2818 * packets containing string lengths N through
2819 * N+7. This won't obscure the order of
2820 * magnitude of the password length, but it will
2821 * introduce a bit of extra uncertainty.
2823 * A few servers (the old 1.2.18 through 1.2.22)
2824 * can't deal with SSH1_MSG_IGNORE. For these
2825 * servers, we need an alternative defence. We make
2826 * use of the fact that the password is interpreted
2827 * as a C string: so we can append a NUL, then some
2830 * One server (a Cisco one) can deal with neither
2831 * SSH1_MSG_IGNORE _nor_ a padded password string.
2832 * For this server we are left with no defences
2833 * against password length sniffing.
2835 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2837 * The server can deal with SSH1_MSG_IGNORE, so
2838 * we can use the primary defence.
2840 int bottom, top, pwlen, i;
2843 pwlen = strlen(s->password);
2845 bottom = 0; /* zero length passwords are OK! :-) */
2848 bottom = pwlen & ~7;
2852 assert(pwlen >= bottom && pwlen <= top);
2854 randomstr = smalloc(top + 1);
2856 for (i = bottom; i <= top; i++) {
2858 defer_packet(ssh, s->pwpkt_type,
2859 PKT_STR, s->password, PKT_END);
2861 for (j = 0; j < i; j++) {
2863 randomstr[j] = random_byte();
2864 } while (randomstr[j] == '\0');
2866 randomstr[i] = '\0';
2867 defer_packet(ssh, SSH1_MSG_IGNORE,
2868 PKT_STR, randomstr, PKT_END);
2871 logevent("Sending password with camouflage packets");
2872 ssh_pkt_defersend(ssh);
2874 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2876 * The server can't deal with SSH1_MSG_IGNORE
2877 * but can deal with padded passwords, so we
2878 * can use the secondary defence.
2884 len = strlen(s->password);
2885 if (len < sizeof(string)) {
2887 strcpy(string, s->password);
2888 len++; /* cover the zero byte */
2889 while (len < sizeof(string)) {
2890 string[len++] = (char) random_byte();
2895 logevent("Sending length-padded password");
2896 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2897 PKT_DATA, ss, len, PKT_END);
2900 * The server has _both_
2901 * BUG_CHOKES_ON_SSH1_IGNORE and
2902 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2903 * therefore nothing we can do.
2906 len = strlen(s->password);
2907 logevent("Sending unpadded password");
2908 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2909 PKT_DATA, s->password, len, PKT_END);
2912 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2915 logevent("Sent password");
2916 memset(s->password, 0, strlen(s->password));
2918 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2919 if (flags & FLAG_VERBOSE)
2920 c_write_str(ssh, "Access denied\r\n");
2921 logevent("Authentication refused");
2922 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2923 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
2928 logevent("Authentication successful");
2933 void sshfwd_close(struct ssh_channel *c)
2937 if (c && !c->closes) {
2939 * If the channel's remoteid is -1, we have sent
2940 * CHANNEL_OPEN for this channel, but it hasn't even been
2941 * acknowledged by the server. So we must set a close flag
2942 * on it now, and then when the server acks the channel
2943 * open, we can close it then.
2945 if (((int)c->remoteid) != -1) {
2946 if (ssh->version == 1) {
2947 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2950 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2951 ssh2_pkt_adduint32(ssh, c->remoteid);
2955 c->closes = 1; /* sent MSG_CLOSE */
2956 if (c->type == CHAN_X11) {
2958 logevent("Forwarded X11 connection terminated");
2959 } else if (c->type == CHAN_SOCKDATA ||
2960 c->type == CHAN_SOCKDATA_DORMANT) {
2962 logevent("Forwarded port closed");
2967 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2971 if (ssh->version == 1) {
2972 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2973 PKT_INT, c->remoteid,
2974 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2976 * In SSH1 we can return 0 here - implying that forwarded
2977 * connections are never individually throttled - because
2978 * the only circumstance that can cause throttling will be
2979 * the whole SSH connection backing up, in which case
2980 * _everything_ will be throttled as a whole.
2984 ssh2_add_channel_data(c, buf, len);
2985 return ssh2_try_send(c);
2989 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2993 if (ssh->version == 1) {
2994 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2995 c->v.v1.throttling = 0;
2996 ssh1_throttle(ssh, -1);
2999 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3003 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3005 crBegin(ssh->ssh1_protocol_crstate);
3009 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3012 if (ssh->state == SSH_STATE_CLOSED)
3015 if (cfg.agentfwd && agent_exists()) {
3016 logevent("Requesting agent forwarding");
3017 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3021 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3022 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3023 bombout((ssh,"Protocol confusion"));
3025 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3026 logevent("Agent forwarding refused");
3028 logevent("Agent forwarding enabled");
3029 ssh->agentfwd_enabled = TRUE;
3033 if (cfg.x11_forward) {
3034 char proto[20], data[64];
3035 logevent("Requesting X11 forwarding");
3036 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3037 data, sizeof(data));
3038 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3039 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3040 PKT_STR, proto, PKT_STR, data,
3041 PKT_INT, x11_get_screen_number(cfg.x11_display),
3044 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3045 PKT_STR, proto, PKT_STR, data, PKT_END);
3050 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3051 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3052 bombout((ssh,"Protocol confusion"));
3054 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3055 logevent("X11 forwarding refused");
3057 logevent("X11 forwarding enabled");
3058 ssh->X11_fwd_enabled = TRUE;
3065 int sport,dport,sserv,dserv;
3066 char sports[256], dports[256], saddr[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++;
3075 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3076 if (*ssh->portfwd_strptr == ':') {
3078 * We've seen a colon in the middle of the
3079 * source port number. This means that
3080 * everything we've seen until now is the
3081 * source _address_, so we'll move it into
3082 * saddr and start sports from the beginning
3085 ssh->portfwd_strptr++;
3087 strcpy(saddr, sports);
3090 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3093 if (*ssh->portfwd_strptr == '\t')
3094 ssh->portfwd_strptr++;
3096 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3097 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3100 if (*ssh->portfwd_strptr == ':')
3101 ssh->portfwd_strptr++;
3103 while (*ssh->portfwd_strptr) {
3104 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3107 ssh->portfwd_strptr++;
3108 dport = atoi(dports);
3112 dport = net_service_lookup(dports);
3114 logeventf(ssh, "Service lookup failed for"
3115 " destination port \"%s\"", dports);
3118 sport = atoi(sports);
3122 sport = net_service_lookup(sports);
3124 logeventf(ssh, "Service lookup failed for source"
3125 " port \"%s\"", sports);
3128 if (sport && dport) {
3130 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3132 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3133 " forwarding to %s:%.*s%.*s%d%.*s",
3134 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3135 (int)(*saddr?1:0), ":",
3136 (int)(sserv ? strlen(sports) : 0), sports,
3137 sserv, "(", sport, sserv, ")",
3139 (int)(dserv ? strlen(dports) : 0), dports,
3140 dserv, "(", dport, dserv, ")");
3142 struct ssh_rportfwd *pf;
3143 pf = smalloc(sizeof(*pf));
3144 strcpy(pf->dhost, host);
3148 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3151 if (add234(ssh->rportfwds, pf) != pf) {
3153 "Duplicate remote port forwarding to %s:%d",
3157 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3158 " forward to %s:%.*s%.*s%d%.*s",
3159 (int)(sserv ? strlen(sports) : 0), sports,
3160 sserv, "(", sport, sserv, ")",
3162 (int)(dserv ? strlen(dports) : 0), dports,
3163 dserv, "(", dport, dserv, ")");
3164 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3172 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3173 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3174 bombout((ssh,"Protocol confusion"));
3176 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3177 c_write_str(ssh, "Server refused port"
3180 logevent("Remote port forwarding enabled");
3188 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3189 PKT_STR, cfg.termtype,
3190 PKT_INT, ssh->term_height,
3191 PKT_INT, ssh->term_width,
3192 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3193 ssh->state = SSH_STATE_INTERMED;
3197 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3198 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3199 bombout((ssh,"Protocol confusion"));
3201 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3202 c_write_str(ssh, "Server refused to allocate pty\r\n");
3203 ssh->editing = ssh->echoing = 1;
3205 logevent("Allocated pty");
3207 ssh->editing = ssh->echoing = 1;
3210 if (cfg.compression) {
3211 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3215 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3216 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3217 bombout((ssh,"Protocol confusion"));
3219 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3220 c_write_str(ssh, "Server refused to compress\r\n");
3222 logevent("Started compression");
3223 ssh->v1_compressing = TRUE;
3224 ssh->cs_comp_ctx = zlib_compress_init();
3225 logevent("Initialised zlib (RFC1950) compression");
3226 ssh->sc_comp_ctx = zlib_decompress_init();
3227 logevent("Initialised zlib (RFC1950) decompression");
3231 * Start the shell or command.
3233 * Special case: if the first-choice command is an SSH2
3234 * subsystem (hence not usable here) and the second choice
3235 * exists, we fall straight back to that.
3238 char *cmd = cfg.remote_cmd_ptr;
3240 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3241 cmd = cfg.remote_cmd_ptr2;
3242 ssh->fallback_cmd = TRUE;
3245 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3247 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3248 logevent("Started session");
3251 ssh->state = SSH_STATE_SESSION;
3252 if (ssh->size_needed)
3253 ssh_size(ssh, ssh->term_width, ssh->term_height);
3254 if (ssh->eof_needed)
3255 ssh_special(ssh, TS_EOF);
3258 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3260 ssh->channels = newtree234(ssh_channelcmp);
3264 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3265 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3266 long len = GET_32BIT(ssh->pktin.body);
3268 from_backend(ssh->frontend,
3269 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3270 ssh->pktin.body + 4, len);
3271 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3272 ssh->v1_stdout_throttling = 1;
3273 ssh1_throttle(ssh, +1);
3275 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3276 ssh->state = SSH_STATE_CLOSED;
3277 logevent("Received disconnect request");
3279 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3280 /* Remote side is trying to open a channel to talk to our
3281 * X-Server. Give them back a local channel number. */
3282 struct ssh_channel *c;
3284 logevent("Received X11 connect request");
3285 /* Refuse if X11 forwarding is disabled. */
3286 if (!ssh->X11_fwd_enabled) {
3287 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3288 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3289 logevent("Rejected X11 connect request");
3291 c = smalloc(sizeof(struct ssh_channel));
3294 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3295 ssh->x11auth) != NULL) {
3296 logevent("opening X11 forward connection failed");
3298 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3299 PKT_INT, GET_32BIT(ssh->pktin.body),
3303 ("opening X11 forward connection succeeded");
3304 c->remoteid = GET_32BIT(ssh->pktin.body);
3305 c->localid = alloc_channel_id(ssh);
3307 c->v.v1.throttling = 0;
3308 c->type = CHAN_X11; /* identify channel type */
3309 add234(ssh->channels, c);
3310 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3311 PKT_INT, c->remoteid, PKT_INT,
3312 c->localid, PKT_END);
3313 logevent("Opened X11 forward channel");
3316 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3317 /* Remote side is trying to open a channel to talk to our
3318 * agent. Give them back a local channel number. */
3319 struct ssh_channel *c;
3321 /* Refuse if agent forwarding is disabled. */
3322 if (!ssh->agentfwd_enabled) {
3323 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3324 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3326 c = smalloc(sizeof(struct ssh_channel));
3328 c->remoteid = GET_32BIT(ssh->pktin.body);
3329 c->localid = alloc_channel_id(ssh);
3331 c->v.v1.throttling = 0;
3332 c->type = CHAN_AGENT; /* identify channel type */
3333 c->u.a.lensofar = 0;
3334 add234(ssh->channels, c);
3335 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3336 PKT_INT, c->remoteid, PKT_INT, c->localid,
3339 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3340 /* Remote side is trying to open a channel to talk to a
3341 * forwarded port. Give them back a local channel number. */
3342 struct ssh_channel *c;
3343 struct ssh_rportfwd pf;
3345 char host[256], buf[1024];
3347 c = smalloc(sizeof(struct ssh_channel));
3350 hostsize = GET_32BIT(ssh->pktin.body+4);
3351 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
3352 if (h+1 < host+sizeof(host))
3357 port = GET_32BIT(p);
3359 strcpy(pf.dhost, host);
3362 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3363 sprintf(buf, "Rejected remote port open request for %s:%d",
3366 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3367 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3369 sprintf(buf, "Received remote port open request for %s:%d",
3372 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3375 sprintf(buf, "Port open failed: %s", e);
3378 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3379 PKT_INT, GET_32BIT(ssh->pktin.body),
3382 c->remoteid = GET_32BIT(ssh->pktin.body);
3383 c->localid = alloc_channel_id(ssh);
3385 c->v.v1.throttling = 0;
3386 c->type = CHAN_SOCKDATA; /* identify channel type */
3387 add234(ssh->channels, c);
3388 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3389 PKT_INT, c->remoteid, PKT_INT,
3390 c->localid, PKT_END);
3391 logevent("Forwarded port opened successfully");
3395 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3396 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3397 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3398 struct ssh_channel *c;
3400 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3401 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3402 c->remoteid = localid;
3403 c->type = CHAN_SOCKDATA;
3404 c->v.v1.throttling = 0;
3405 pfd_confirm(c->u.pfd.s);
3408 if (c && c->closes) {
3410 * We have a pending close on this channel,
3411 * which we decided on before the server acked
3412 * the channel open. So now we know the
3413 * remoteid, we can close it again.
3415 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3416 PKT_INT, c->remoteid, PKT_END);
3419 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3420 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3421 struct ssh_channel *c;
3423 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3424 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3425 logevent("Forwarded connection refused by server");
3426 pfd_close(c->u.pfd.s);
3427 del234(ssh->channels, c);
3431 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3432 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3433 /* Remote side closes a channel. */
3434 unsigned i = GET_32BIT(ssh->pktin.body);
3435 struct ssh_channel *c;
3436 c = find234(ssh->channels, &i, ssh_channelfind);
3437 if (c && ((int)c->remoteid) != -1) {
3440 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3442 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3443 logevent("Forwarded X11 connection terminated");
3444 assert(c->u.x11.s != NULL);
3445 x11_close(c->u.x11.s);
3448 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3449 logevent("Forwarded port closed");
3450 assert(c->u.pfd.s != NULL);
3451 pfd_close(c->u.pfd.s);
3455 c->closes |= (closetype << 2); /* seen this message */
3456 if (!(c->closes & closetype)) {
3457 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3459 c->closes |= closetype; /* sent it too */
3462 if (c->closes == 15) {
3463 del234(ssh->channels, c);
3467 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3468 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3469 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3472 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3473 /* Data sent down one of our channels. */
3474 int i = GET_32BIT(ssh->pktin.body);
3475 int len = GET_32BIT(ssh->pktin.body + 4);
3476 unsigned char *p = ssh->pktin.body + 8;
3477 struct ssh_channel *c;
3478 c = find234(ssh->channels, &i, ssh_channelfind);
3483 bufsize = x11_send(c->u.x11.s, p, len);
3486 bufsize = pfd_send(c->u.pfd.s, p, len);
3489 /* Data for an agent message. Buffer it. */
3491 if (c->u.a.lensofar < 4) {
3492 int l = min(4 - c->u.a.lensofar, len);
3493 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3497 c->u.a.lensofar += l;
3499 if (c->u.a.lensofar == 4) {
3501 4 + GET_32BIT(c->u.a.msglen);
3502 c->u.a.message = smalloc(c->u.a.totallen);
3503 memcpy(c->u.a.message, c->u.a.msglen, 4);
3505 if (c->u.a.lensofar >= 4 && len > 0) {
3507 min(c->u.a.totallen - c->u.a.lensofar,
3509 memcpy(c->u.a.message + c->u.a.lensofar, p,
3513 c->u.a.lensofar += l;
3515 if (c->u.a.lensofar == c->u.a.totallen) {
3516 void *reply, *sentreply;
3518 agent_query(c->u.a.message,
3519 c->u.a.totallen, &reply,
3524 /* Fake SSH_AGENT_FAILURE. */
3525 sentreply = "\0\0\0\1\5";
3528 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3529 PKT_INT, c->remoteid,
3531 PKT_DATA, sentreply, replylen,
3535 sfree(c->u.a.message);
3536 c->u.a.lensofar = 0;
3539 bufsize = 0; /* agent channels never back up */
3542 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3543 c->v.v1.throttling = 1;
3544 ssh1_throttle(ssh, +1);
3547 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3548 /* may be from EXEC_SHELL on some servers */
3549 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3550 /* may be from EXEC_SHELL on some servers
3551 * if no pty is available or in other odd cases. Ignore */
3552 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3554 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3555 sprintf(buf, "Server sent command exit status %d",
3558 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3560 * In case `helpful' firewalls or proxies tack
3561 * extra human-readable text on the end of the
3562 * session which we might mistake for another
3563 * encrypted packet, we close the session once
3564 * we've sent EXIT_CONFIRMATION.
3566 ssh->state = SSH_STATE_CLOSED;
3569 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3574 int len = min(inlen, 512);
3575 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3576 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3587 * Utility routine for decoding comma-separated strings in KEXINIT.
3589 static int in_commasep_string(char *needle, char *haystack, int haylen)
3592 if (!needle || !haystack) /* protect against null pointers */
3594 needlen = strlen(needle);
3597 * Is it at the start of the string?
3599 if (haylen >= needlen && /* haystack is long enough */
3600 !memcmp(needle, haystack, needlen) && /* initial match */
3601 (haylen == needlen || haystack[needlen] == ',')
3602 /* either , or EOS follows */
3606 * If not, search for the next comma and resume after that.
3607 * If no comma found, terminate.
3609 while (haylen > 0 && *haystack != ',')
3610 haylen--, haystack++;
3613 haylen--, haystack++; /* skip over comma itself */
3618 * SSH2 key creation method.
3620 static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
3624 /* First 20 bytes. */
3626 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3628 SHA_Bytes(&s, H, 20);
3629 SHA_Bytes(&s, &chr, 1);
3630 SHA_Bytes(&s, sessid, 20);
3631 SHA_Final(&s, keyspace);
3632 /* Next 20 bytes. */
3634 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3636 SHA_Bytes(&s, H, 20);
3637 SHA_Bytes(&s, keyspace, 20);
3638 SHA_Final(&s, keyspace + 20);
3642 * Handle the SSH2 transport layer.
3644 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3646 struct do_ssh2_transport_state {
3647 int nbits, pbits, warn;
3648 Bignum p, g, e, f, K;
3649 int kex_init_value, kex_reply_value;
3650 const struct ssh_mac **maclist;
3652 const struct ssh2_cipher *cscipher_tobe;
3653 const struct ssh2_cipher *sccipher_tobe;
3654 const struct ssh_mac *csmac_tobe;
3655 const struct ssh_mac *scmac_tobe;
3656 const struct ssh_compress *cscomp_tobe;
3657 const struct ssh_compress *sccomp_tobe;
3658 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3659 int hostkeylen, siglen;
3660 void *hkey; /* actual host key */
3661 unsigned char exchange_hash[20];
3662 int n_preferred_ciphers;
3663 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3664 const struct ssh_compress *preferred_comp;
3667 crState(do_ssh2_transport_state);
3669 crBegin(ssh->do_ssh2_transport_crstate);
3671 s->cscipher_tobe = s->sccipher_tobe = NULL;
3672 s->csmac_tobe = s->scmac_tobe = NULL;
3673 s->cscomp_tobe = s->sccomp_tobe = NULL;
3681 * Set up the preferred ciphers. (NULL => warn below here)
3683 s->n_preferred_ciphers = 0;
3684 for (i = 0; i < CIPHER_MAX; i++) {
3685 switch (cfg.ssh_cipherlist[i]) {
3686 case CIPHER_BLOWFISH:
3687 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3690 if (cfg.ssh2_des_cbc) {
3691 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3695 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3698 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3701 /* Flag for later. Don't bother if it's the last in
3703 if (i < CIPHER_MAX - 1) {
3704 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3712 * Set up preferred compression.
3714 if (cfg.compression)
3715 s->preferred_comp = &ssh_zlib;
3717 s->preferred_comp = &ssh_comp_none;
3720 * Be prepared to work around the buggy MAC problem.
3722 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3723 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3725 s->maclist = macs, s->nmacs = lenof(macs);
3729 int i, j, cipherstr_started;
3732 * Construct and send our key exchange packet.
3734 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3735 for (i = 0; i < 16; i++)
3736 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3737 /* List key exchange algorithms. */
3738 ssh2_pkt_addstring_start(ssh);
3739 for (i = 0; i < lenof(kex_algs); i++) {
3740 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3741 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3743 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3744 if (i < lenof(kex_algs) - 1)
3745 ssh2_pkt_addstring_str(ssh, ",");
3747 /* List server host key algorithms. */
3748 ssh2_pkt_addstring_start(ssh);
3749 for (i = 0; i < lenof(hostkey_algs); i++) {
3750 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3751 if (i < lenof(hostkey_algs) - 1)
3752 ssh2_pkt_addstring_str(ssh, ",");
3754 /* List client->server encryption algorithms. */
3755 ssh2_pkt_addstring_start(ssh);
3756 cipherstr_started = 0;
3757 for (i = 0; i < s->n_preferred_ciphers; i++) {
3758 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3759 if (!c) continue; /* warning flag */
3760 for (j = 0; j < c->nciphers; j++) {
3761 if (cipherstr_started)
3762 ssh2_pkt_addstring_str(ssh, ",");
3763 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3764 cipherstr_started = 1;
3767 /* List server->client encryption algorithms. */
3768 ssh2_pkt_addstring_start(ssh);
3769 cipherstr_started = 0;
3770 for (i = 0; i < s->n_preferred_ciphers; i++) {
3771 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3772 if (!c) continue; /* warning flag */
3773 for (j = 0; j < c->nciphers; j++) {
3774 if (cipherstr_started)
3775 ssh2_pkt_addstring_str(ssh, ",");
3776 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3777 cipherstr_started = 1;
3780 /* List client->server MAC algorithms. */
3781 ssh2_pkt_addstring_start(ssh);
3782 for (i = 0; i < s->nmacs; i++) {
3783 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3784 if (i < s->nmacs - 1)
3785 ssh2_pkt_addstring_str(ssh, ",");
3787 /* List server->client MAC algorithms. */
3788 ssh2_pkt_addstring_start(ssh);
3789 for (i = 0; i < s->nmacs; i++) {
3790 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3791 if (i < s->nmacs - 1)
3792 ssh2_pkt_addstring_str(ssh, ",");
3794 /* List client->server compression algorithms. */
3795 ssh2_pkt_addstring_start(ssh);
3796 for (i = 0; i < lenof(compressions) + 1; i++) {
3797 const struct ssh_compress *c =
3798 i == 0 ? s->preferred_comp : compressions[i - 1];
3799 ssh2_pkt_addstring_str(ssh, c->name);
3800 if (i < lenof(compressions))
3801 ssh2_pkt_addstring_str(ssh, ",");
3803 /* List server->client compression algorithms. */
3804 ssh2_pkt_addstring_start(ssh);
3805 for (i = 0; i < lenof(compressions) + 1; i++) {
3806 const struct ssh_compress *c =
3807 i == 0 ? s->preferred_comp : compressions[i - 1];
3808 ssh2_pkt_addstring_str(ssh, c->name);
3809 if (i < lenof(compressions))
3810 ssh2_pkt_addstring_str(ssh, ",");
3812 /* List client->server languages. Empty list. */
3813 ssh2_pkt_addstring_start(ssh);
3814 /* List server->client languages. Empty list. */
3815 ssh2_pkt_addstring_start(ssh);
3816 /* First KEX packet does _not_ follow, because we're not that brave. */
3817 ssh2_pkt_addbool(ssh, FALSE);
3819 ssh2_pkt_adduint32(ssh, 0);
3822 ssh->exhash = ssh->exhashbase;
3823 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3829 if (ssh->pktin.length > 5)
3830 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3833 * Now examine the other side's KEXINIT to see what we're up
3840 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3841 bombout((ssh,"expected key exchange packet from server"));
3845 ssh->hostkey = NULL;
3846 s->cscipher_tobe = NULL;
3847 s->sccipher_tobe = NULL;
3848 s->csmac_tobe = NULL;
3849 s->scmac_tobe = NULL;
3850 s->cscomp_tobe = NULL;
3851 s->sccomp_tobe = NULL;
3852 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3853 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3854 for (i = 0; i < lenof(kex_algs); i++) {
3855 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3856 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3858 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3859 ssh->kex = kex_algs[i];
3863 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3864 for (i = 0; i < lenof(hostkey_algs); i++) {
3865 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3866 ssh->hostkey = hostkey_algs[i];
3870 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3872 for (i = 0; i < s->n_preferred_ciphers; i++) {
3873 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3877 for (j = 0; j < c->nciphers; j++) {
3878 if (in_commasep_string(c->list[j]->name, str, len)) {
3879 s->cscipher_tobe = c->list[j];
3884 if (s->cscipher_tobe) {
3886 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3890 if (!s->cscipher_tobe) {
3891 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3892 str ? str : "(null)"));
3896 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3898 for (i = 0; i < s->n_preferred_ciphers; i++) {
3899 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3903 for (j = 0; j < c->nciphers; j++) {
3904 if (in_commasep_string(c->list[j]->name, str, len)) {
3905 s->sccipher_tobe = c->list[j];
3910 if (s->sccipher_tobe) {
3912 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3916 if (!s->sccipher_tobe) {
3917 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3918 str ? str : "(null)"));
3922 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3923 for (i = 0; i < s->nmacs; i++) {
3924 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3925 s->csmac_tobe = s->maclist[i];
3929 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3930 for (i = 0; i < s->nmacs; i++) {
3931 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3932 s->scmac_tobe = s->maclist[i];
3936 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3937 for (i = 0; i < lenof(compressions) + 1; i++) {
3938 const struct ssh_compress *c =
3939 i == 0 ? s->preferred_comp : compressions[i - 1];
3940 if (in_commasep_string(c->name, str, len)) {
3945 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3946 for (i = 0; i < lenof(compressions) + 1; i++) {
3947 const struct ssh_compress *c =
3948 i == 0 ? s->preferred_comp : compressions[i - 1];
3949 if (in_commasep_string(c->name, str, len)) {
3957 * Work out the number of bits of key we will need from the key
3958 * exchange. We start with the maximum key length of either
3964 csbits = s->cscipher_tobe->keylen;
3965 scbits = s->sccipher_tobe->keylen;
3966 s->nbits = (csbits > scbits ? csbits : scbits);
3968 /* The keys only have 160-bit entropy, since they're based on
3969 * a SHA-1 hash. So cap the key size at 160 bits. */
3974 * If we're doing Diffie-Hellman group exchange, start by
3975 * requesting a group.
3977 if (ssh->kex == &ssh_diffiehellman_gex) {
3978 logevent("Doing Diffie-Hellman group exchange");
3979 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3981 * Work out how big a DH group we will need to allow that
3984 s->pbits = 512 << ((s->nbits - 1) / 64);
3985 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3986 ssh2_pkt_adduint32(ssh, s->pbits);
3990 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3991 bombout((ssh,"expected key exchange group packet from server"));
3994 s->p = ssh2_pkt_getmp(ssh);
3995 s->g = ssh2_pkt_getmp(ssh);
3996 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3997 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3998 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
4000 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
4001 ssh->kex_ctx = dh_setup_group1();
4002 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4003 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4006 logevent("Doing Diffie-Hellman key exchange");
4008 * Now generate and send e for Diffie-Hellman.
4010 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4011 ssh2_pkt_init(ssh, s->kex_init_value);
4012 ssh2_pkt_addmp(ssh, s->e);
4016 if (ssh->pktin.type != s->kex_reply_value) {
4017 bombout((ssh,"expected key exchange reply packet from server"));
4020 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4021 s->f = ssh2_pkt_getmp(ssh);
4022 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4024 s->K = dh_find_K(ssh->kex_ctx, s->f);
4026 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4027 if (ssh->kex == &ssh_diffiehellman_gex) {
4028 sha_uint32(&ssh->exhash, s->pbits);
4029 sha_mpint(&ssh->exhash, s->p);
4030 sha_mpint(&ssh->exhash, s->g);
4032 sha_mpint(&ssh->exhash, s->e);
4033 sha_mpint(&ssh->exhash, s->f);
4034 sha_mpint(&ssh->exhash, s->K);
4035 SHA_Final(&ssh->exhash, s->exchange_hash);
4037 dh_cleanup(ssh->kex_ctx);
4040 debug(("Exchange hash is:\n"));
4041 dmemdump(s->exchange_hash, 20);
4044 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4046 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4047 s->exchange_hash, 20)) {
4048 bombout((ssh,"Server's host key did not match the signature supplied"));
4053 * Authenticate remote host: verify host key. (We've already
4054 * checked the signature of the exchange hash.)
4056 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4057 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4058 verify_ssh_host_key(ssh->frontend,
4059 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4060 s->keystr, s->fingerprint);
4061 if (s->first_kex) { /* don't bother logging this in rekeys */
4062 logevent("Host key fingerprint is:");
4063 logevent(s->fingerprint);
4065 sfree(s->fingerprint);
4067 ssh->hostkey->freekey(s->hkey);
4070 * Send SSH2_MSG_NEWKEYS.
4072 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4076 * Expect SSH2_MSG_NEWKEYS from server.
4079 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4080 bombout((ssh,"expected new-keys packet from server"));
4085 * Create and initialise session keys.
4087 if (ssh->cs_cipher_ctx)
4088 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4089 ssh->cscipher = s->cscipher_tobe;
4090 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4092 if (ssh->sc_cipher_ctx)
4093 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4094 ssh->sccipher = s->sccipher_tobe;
4095 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4097 if (ssh->cs_mac_ctx)
4098 ssh->csmac->free_context(ssh->cs_mac_ctx);
4099 ssh->csmac = s->csmac_tobe;
4100 ssh->cs_mac_ctx = ssh->csmac->make_context();
4102 if (ssh->sc_mac_ctx)
4103 ssh->scmac->free_context(ssh->sc_mac_ctx);
4104 ssh->scmac = s->scmac_tobe;
4105 ssh->sc_mac_ctx = ssh->scmac->make_context();
4107 if (ssh->cs_comp_ctx)
4108 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4109 ssh->cscomp = s->cscomp_tobe;
4110 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4112 if (ssh->sc_comp_ctx)
4113 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4114 ssh->sccomp = s->sccomp_tobe;
4115 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4118 * Set IVs after keys. Here we use the exchange hash from the
4119 * _first_ key exchange.
4122 unsigned char keyspace[40];
4124 memcpy(ssh->v2_session_id, s->exchange_hash,
4125 sizeof(s->exchange_hash));
4126 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4127 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4128 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4129 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4130 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4131 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4132 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4133 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4134 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4135 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4136 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4137 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4139 logeventf(ssh, "Initialised %.200s client->server encryption",
4140 ssh->cscipher->text_name);
4141 logeventf(ssh, "Initialised %.200s server->client encryption",
4142 ssh->sccipher->text_name);
4143 if (ssh->cscomp->text_name)
4144 logeventf(ssh, "Initialised %s compression",
4145 ssh->cscomp->text_name);
4146 if (ssh->sccomp->text_name)
4147 logeventf(ssh, "Initialised %s decompression",
4148 ssh->sccomp->text_name);
4151 * If this is the first key exchange phase, we must pass the
4152 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4153 * wants to see it but because it will need time to initialise
4154 * itself before it sees an actual packet. In subsequent key
4155 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4156 * it would only confuse the layer above.
4158 if (!s->first_kex) {
4164 * Now we're encrypting. Begin returning 1 to the protocol main
4165 * function so that other things can run on top of the
4166 * transport. If we ever see a KEXINIT, we must go back to the
4169 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4172 logevent("Server initiated key re-exchange");
4173 goto begin_key_exchange;
4179 * Add data to an SSH2 channel output buffer.
4181 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4184 bufchain_add(&c->v.v2.outbuffer, buf, len);
4188 * Attempt to send data on an SSH2 channel.
4190 static int ssh2_try_send(struct ssh_channel *c)
4194 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4197 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4198 if ((unsigned)len > c->v.v2.remwindow)
4199 len = c->v.v2.remwindow;
4200 if ((unsigned)len > c->v.v2.remmaxpkt)
4201 len = c->v.v2.remmaxpkt;
4202 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4203 ssh2_pkt_adduint32(ssh, c->remoteid);
4204 ssh2_pkt_addstring_start(ssh);
4205 ssh2_pkt_addstring_data(ssh, data, len);
4207 bufchain_consume(&c->v.v2.outbuffer, len);
4208 c->v.v2.remwindow -= len;
4212 * After having sent as much data as we can, return the amount
4215 return bufchain_size(&c->v.v2.outbuffer);
4219 * Potentially enlarge the window on an SSH2 channel.
4221 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4226 * Never send WINDOW_ADJUST for a channel that the remote side
4227 * already thinks it's closed; there's no point, since it won't
4228 * be sending any more data anyway.
4233 if (newwin > c->v.v2.locwindow) {
4234 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4235 ssh2_pkt_adduint32(ssh, c->remoteid);
4236 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4238 c->v.v2.locwindow = newwin;
4243 * Handle the SSH2 userauth and connection layers.
4245 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4247 struct do_ssh2_authconn_state {
4249 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4251 AUTH_KEYBOARD_INTERACTIVE
4255 AUTH_TYPE_PUBLICKEY,
4256 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4257 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4259 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4260 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4262 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4263 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4264 int kbd_inter_running;
4266 int num_prompts, curr_prompt, echo;
4271 void *publickey_blob;
4272 int publickey_bloblen;
4273 unsigned char request[5], *response, *p;
4277 char *pkblob, *alg, *commentp;
4278 int pklen, alglen, commentlen;
4279 int siglen, retlen, len;
4280 char *q, *agentreq, *ret;
4283 crState(do_ssh2_authconn_state);
4285 crBegin(ssh->do_ssh2_authconn_crstate);
4288 * Request userauth protocol, and await a response to it.
4290 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4291 ssh2_pkt_addstring(ssh, "ssh-userauth");
4293 crWaitUntilV(ispkt);
4294 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4295 bombout((ssh,"Server refused user authentication protocol"));
4300 * We repeat this whole loop, including the username prompt,
4301 * until we manage a successful authentication. If the user
4302 * types the wrong _password_, they can be sent back to the
4303 * beginning to try another username, if this is configured on.
4304 * (If they specify a username in the config, they are never
4305 * asked, even if they do give a wrong password.)
4307 * I think this best serves the needs of
4309 * - the people who have no configuration, no keys, and just
4310 * want to try repeated (username,password) pairs until they
4311 * type both correctly
4313 * - people who have keys and configuration but occasionally
4314 * need to fall back to passwords
4316 * - people with a key held in Pageant, who might not have
4317 * logged in to a particular machine before; so they want to
4318 * type a username, and then _either_ their key will be
4319 * accepted, _or_ they will type a password. If they mistype
4320 * the username they will want to be able to get back and
4323 s->username[0] = '\0';
4324 s->got_username = FALSE;
4329 if (s->got_username && !cfg.change_username) {
4331 * We got a username last time round this loop, and
4332 * with change_username turned off we don't try to get
4335 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4336 if (ssh_get_line && !ssh_getline_pw_only) {
4337 if (!ssh_get_line("login as: ",
4338 s->username, sizeof(s->username), FALSE)) {
4340 * get_line failed to get a username.
4343 logevent("No username provided. Abandoning session.");
4344 ssh->state = SSH_STATE_CLOSED;
4348 int ret; /* need not be saved across crReturn */
4349 c_write_str(ssh, "login as: ");
4351 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4353 crWaitUntilV(!ispkt);
4354 ret = process_userpass_input(ssh, in, inlen);
4358 c_write_str(ssh, "\r\n");
4360 s->username[strcspn(s->username, "\n\r")] = '\0';
4363 strncpy(s->username, cfg.username, sizeof(s->username));
4364 s->username[sizeof(s->username)-1] = '\0';
4365 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4366 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4367 c_write_str(ssh, stuff);
4371 s->got_username = TRUE;
4374 * Send an authentication request using method "none": (a)
4375 * just in case it succeeds, and (b) so that we know what
4376 * authentication methods we can usefully try next.
4378 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4380 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4381 ssh2_pkt_addstring(ssh, s->username);
4382 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4383 ssh2_pkt_addstring(ssh, "none"); /* method */
4385 s->type = AUTH_TYPE_NONE;
4387 s->we_are_in = FALSE;
4389 s->tried_pubkey_config = FALSE;
4390 s->tried_agent = FALSE;
4391 s->tried_keyb_inter = FALSE;
4392 s->kbd_inter_running = FALSE;
4393 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4396 logeventf(ssh, "Reading private key file \"%.150s\"", cfg.keyfile);
4397 keytype = key_type(cfg.keyfile);
4398 if (keytype == SSH_KEYTYPE_SSH2) {
4400 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4401 &s->publickey_bloblen);
4404 logeventf(ssh, "Unable to use this key file (%s)",
4405 key_type_to_str(keytype));
4406 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4407 " (%s)\r\n", cfg.keyfile,
4408 key_type_to_str(keytype));
4409 c_write_str(ssh, msgbuf);
4411 s->publickey_blob = NULL;
4414 s->publickey_blob = NULL;
4418 * Wait for the result of the last authentication request.
4421 crWaitUntilV(ispkt);
4422 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4426 * Don't show the banner if we're operating in
4427 * non-verbose non-interactive mode. (It's probably
4428 * a script, which means nobody will read the
4429 * banner _anyway_, and moreover the printing of
4430 * the banner will screw up processing on the
4431 * output of (say) plink.)
4433 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4434 ssh2_pkt_getstring(ssh, &banner, &size);
4436 c_write_untrusted(ssh, banner, size);
4438 crWaitUntilV(ispkt);
4440 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4441 logevent("Access granted");
4442 s->we_are_in = TRUE;
4446 if (s->kbd_inter_running &&
4447 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4449 * This is either a further set-of-prompts packet
4450 * in keyboard-interactive authentication, or it's
4451 * the same one and we came back here with `gotit'
4452 * set. In the former case, we must reset the
4453 * curr_prompt variable.
4457 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4458 bombout((ssh,"Strange packet received during authentication: type %d",
4466 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4467 * we can look at the string in it and know what we can
4468 * helpfully try next.
4470 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4473 ssh2_pkt_getstring(ssh, &methods, &methlen);
4474 s->kbd_inter_running = FALSE;
4475 if (!ssh2_pkt_getbool(ssh)) {
4477 * We have received an unequivocal Access
4478 * Denied. This can translate to a variety of
4481 * - if we'd just tried "none" authentication,
4482 * it's not worth printing anything at all
4484 * - if we'd just tried a public key _offer_,
4485 * the message should be "Server refused our
4486 * key" (or no message at all if the key
4487 * came from Pageant)
4489 * - if we'd just tried anything else, the
4490 * message really should be "Access denied".
4492 * Additionally, if we'd just tried password
4493 * authentication, we should break out of this
4494 * whole loop so as to go back to the username
4497 if (s->type == AUTH_TYPE_NONE) {
4499 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4500 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4501 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4502 c_write_str(ssh, "Server refused our key\r\n");
4503 logevent("Server refused public key");
4504 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4505 /* server declined keyboard-interactive; ignore */
4507 c_write_str(ssh, "Access denied\r\n");
4508 logevent("Access denied");
4509 if (s->type == AUTH_TYPE_PASSWORD) {
4510 s->we_are_in = FALSE;
4515 c_write_str(ssh, "Further authentication required\r\n");
4516 logevent("Further authentication required");
4520 in_commasep_string("publickey", methods, methlen);
4522 in_commasep_string("password", methods, methlen);
4523 s->can_keyb_inter = cfg.try_ki_auth &&
4524 in_commasep_string("keyboard-interactive", methods, methlen);
4528 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4531 * Most password/passphrase prompts will be
4532 * non-echoing, so we set this to 0 by default.
4533 * Exception is that some keyboard-interactive prompts
4534 * can be echoing, in which case we'll set this to 1.
4538 if (!s->method && s->can_pubkey &&
4539 agent_exists() && !s->tried_agent) {
4541 * Attempt public-key authentication using Pageant.
4546 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4547 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4549 s->tried_agent = TRUE;
4551 logevent("Pageant is running. Requesting keys.");
4553 /* Request the keys held by the agent. */
4554 PUT_32BIT(s->request, 1);
4555 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4556 agent_query(s->request, 5, &r, &s->responselen);
4557 s->response = (unsigned char *) r;
4558 if (s->response && s->responselen >= 5 &&
4559 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4560 s->p = s->response + 5;
4561 s->nkeys = GET_32BIT(s->p);
4565 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4568 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4573 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4576 s->pklen = GET_32BIT(s->p);
4578 if (s->publickey_blob &&
4579 s->pklen == s->publickey_bloblen &&
4580 !memcmp(s->p, s->publickey_blob,
4581 s->publickey_bloblen)) {
4582 logevent("This key matches configured key file");
4583 s->tried_pubkey_config = 1;
4587 s->alglen = GET_32BIT(s->pkblob);
4588 s->alg = s->pkblob + 4;
4589 s->commentlen = GET_32BIT(s->p);
4592 s->p += s->commentlen;
4593 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4594 ssh2_pkt_addstring(ssh, s->username);
4595 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4596 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4597 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4598 ssh2_pkt_addstring_start(ssh);
4599 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4600 ssh2_pkt_addstring_start(ssh);
4601 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4604 crWaitUntilV(ispkt);
4605 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4606 logevent("Key refused");
4610 if (flags & FLAG_VERBOSE) {
4611 c_write_str(ssh, "Authenticating with "
4613 c_write(ssh, s->commentp, s->commentlen);
4614 c_write_str(ssh, "\" from agent\r\n");
4618 * Server is willing to accept the key.
4619 * Construct a SIGN_REQUEST.
4621 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4622 ssh2_pkt_addstring(ssh, s->username);
4623 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4624 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4625 ssh2_pkt_addbool(ssh, TRUE);
4626 ssh2_pkt_addstring_start(ssh);
4627 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4628 ssh2_pkt_addstring_start(ssh);
4629 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4631 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4632 s->len = 1; /* message type */
4633 s->len += 4 + s->pklen; /* key blob */
4634 s->len += 4 + s->siglen; /* data to sign */
4635 s->len += 4; /* flags */
4636 s->agentreq = smalloc(4 + s->len);
4637 PUT_32BIT(s->agentreq, s->len);
4638 s->q = s->agentreq + 4;
4639 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4640 PUT_32BIT(s->q, s->pklen);
4642 memcpy(s->q, s->pkblob, s->pklen);
4644 PUT_32BIT(s->q, s->siglen);
4646 /* Now the data to be signed... */
4647 PUT_32BIT(s->q, 20);
4649 memcpy(s->q, ssh->v2_session_id, 20);
4651 memcpy(s->q, ssh->pktout.data + 5,
4652 ssh->pktout.length - 5);
4653 s->q += ssh->pktout.length - 5;
4654 /* And finally the (zero) flags word. */
4656 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4660 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4661 logevent("Sending Pageant's response");
4662 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4664 GET_32BIT(s->ret + 5));
4670 ("Pageant failed to answer challenge");
4680 if (!s->method && s->can_pubkey && s->publickey_blob
4681 && !s->tried_pubkey_config) {
4682 unsigned char *pub_blob;
4683 char *algorithm, *comment;
4686 s->tried_pubkey_config = TRUE;
4688 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4689 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4692 * Try the public key supplied in the configuration.
4694 * First, offer the public blob to see if the server is
4695 * willing to accept it.
4697 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4700 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4701 ssh2_pkt_addstring(ssh, s->username);
4702 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4703 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4704 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4705 ssh2_pkt_addstring(ssh, algorithm);
4706 ssh2_pkt_addstring_start(ssh);
4707 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4709 logevent("Offered public key"); /* FIXME */
4711 crWaitUntilV(ispkt);
4712 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4714 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4715 continue; /* key refused; give up on it */
4718 logevent("Offer of public key accepted");
4720 * Actually attempt a serious authentication using
4723 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4724 sprintf(s->pwprompt,
4725 "Passphrase for key \"%.100s\": ",
4731 c_write_str(ssh, "Authenticating with public key \"");
4732 c_write_str(ssh, comment);
4733 c_write_str(ssh, "\"\r\n");
4734 s->method = AUTH_PUBLICKEY_FILE;
4738 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4739 s->method = AUTH_KEYBOARD_INTERACTIVE;
4740 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4741 s->tried_keyb_inter = TRUE;
4743 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4744 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4746 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4747 ssh2_pkt_addstring(ssh, s->username);
4748 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4749 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4750 ssh2_pkt_addstring(ssh, ""); /* lang */
4751 ssh2_pkt_addstring(ssh, "");
4754 crWaitUntilV(ispkt);
4755 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4756 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4758 logevent("Keyboard-interactive authentication refused");
4759 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4763 s->kbd_inter_running = TRUE;
4767 if (s->kbd_inter_running) {
4768 s->method = AUTH_KEYBOARD_INTERACTIVE;
4769 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4770 s->tried_keyb_inter = TRUE;
4772 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4773 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4775 if (s->curr_prompt == 0) {
4777 * We've got a fresh USERAUTH_INFO_REQUEST.
4778 * Display header data, and start going through
4781 char *name, *inst, *lang;
4782 int name_len, inst_len, lang_len;
4784 ssh2_pkt_getstring(ssh, &name, &name_len);
4785 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4786 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4788 c_write_untrusted(ssh, name, name_len);
4789 c_write_str(ssh, "\r\n");
4792 c_write_untrusted(ssh, inst, inst_len);
4793 c_write_str(ssh, "\r\n");
4795 s->num_prompts = ssh2_pkt_getuint32(ssh);
4799 * If there are prompts remaining in the packet,
4800 * display one and get a response.
4802 if (s->curr_prompt < s->num_prompts) {
4806 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4807 if (prompt_len > 0) {
4808 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4809 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4810 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4813 "<server failed to send prompt>: ");
4815 s->echo = ssh2_pkt_getbool(ssh);
4821 if (!s->method && s->can_passwd) {
4822 s->method = AUTH_PASSWORD;
4823 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4824 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4825 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4832 if (!ssh_get_line(s->pwprompt, s->password,
4833 sizeof(s->password), TRUE)) {
4835 * get_line failed to get a password (for
4836 * example because one was supplied on the
4837 * command line which has already failed to
4840 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4841 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4842 ssh2_pkt_addstring(ssh, "No more passwords available"
4844 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4846 logevent("Unable to authenticate");
4847 connection_fatal(ssh->frontend,
4848 "Unable to authenticate");
4849 ssh->state = SSH_STATE_CLOSED;
4853 int ret; /* need not be saved across crReturn */
4854 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4857 setup_userpass_input(ssh, s->password,
4858 sizeof(s->password), s->echo);
4860 crWaitUntilV(!ispkt);
4861 ret = process_userpass_input(ssh, in, inlen);
4865 c_write_str(ssh, "\r\n");
4869 if (s->method == AUTH_PUBLICKEY_FILE) {
4871 * We have our passphrase. Now try the actual authentication.
4873 struct ssh2_userkey *key;
4875 key = ssh2_load_userkey(cfg.keyfile, s->password);
4876 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4877 if (key == SSH2_WRONG_PASSPHRASE) {
4878 c_write_str(ssh, "Wrong passphrase\r\n");
4879 s->tried_pubkey_config = FALSE;
4881 c_write_str(ssh, "Unable to load private key\r\n");
4882 s->tried_pubkey_config = TRUE;
4884 /* Send a spurious AUTH_NONE to return to the top. */
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, "none"); /* method */
4890 s->type = AUTH_TYPE_NONE;
4892 unsigned char *pkblob, *sigblob, *sigdata;
4893 int pkblob_len, sigblob_len, sigdata_len;
4896 * We have loaded the private key and the server
4897 * has announced that it's willing to accept it.
4898 * Hallelujah. Generate a signature and send it.
4900 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4901 ssh2_pkt_addstring(ssh, s->username);
4902 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4903 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4904 ssh2_pkt_addbool(ssh, TRUE);
4905 ssh2_pkt_addstring(ssh, key->alg->name);
4906 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4907 ssh2_pkt_addstring_start(ssh);
4908 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
4911 * The data to be signed is:
4915 * followed by everything so far placed in the
4918 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4919 sigdata = smalloc(sigdata_len);
4920 PUT_32BIT(sigdata, 20);
4921 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4922 memcpy(sigdata + 24, ssh->pktout.data + 5,
4923 ssh->pktout.length - 5);
4924 sigblob = key->alg->sign(key->data, sigdata,
4925 sigdata_len, &sigblob_len);
4926 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4927 sigblob, sigblob_len);
4933 s->type = AUTH_TYPE_PUBLICKEY;
4935 } else if (s->method == AUTH_PASSWORD) {
4937 * We send the password packet lumped tightly together with
4938 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4939 * string long enough to make the total length of the two
4940 * packets constant. This should ensure that a passive
4941 * listener doing traffic analyis can't work out the length
4944 * For this to work, we need an assumption about the
4945 * maximum length of the password packet. I think 256 is
4946 * pretty conservative. Anyone using a password longer than
4947 * that probably doesn't have much to worry about from
4948 * people who find out how long their password is!
4950 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4951 ssh2_pkt_addstring(ssh, s->username);
4952 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4953 ssh2_pkt_addstring(ssh, "password");
4954 ssh2_pkt_addbool(ssh, FALSE);
4955 ssh2_pkt_addstring(ssh, s->password);
4956 ssh2_pkt_defer(ssh);
4958 * We'll include a string that's an exact multiple of the
4959 * cipher block size. If the cipher is NULL for some
4960 * reason, we don't do this trick at all because we gain
4963 if (ssh->cscipher) {
4966 stringlen = (256 - ssh->deferred_len);
4967 stringlen += ssh->cscipher->blksize - 1;
4968 stringlen -= (stringlen % ssh->cscipher->blksize);
4971 * Temporarily disable actual compression,
4972 * so we can guarantee to get this string
4973 * exactly the length we want it. The
4974 * compression-disabling routine should
4975 * return an integer indicating how many
4976 * bytes we should adjust our string length
4980 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4982 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4983 ssh2_pkt_addstring_start(ssh);
4984 for (i = 0; i < stringlen; i++) {
4985 char c = (char) random_byte();
4986 ssh2_pkt_addstring_data(ssh, &c, 1);
4988 ssh2_pkt_defer(ssh);
4990 ssh_pkt_defersend(ssh);
4991 logevent("Sent password");
4992 s->type = AUTH_TYPE_PASSWORD;
4993 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4994 if (s->curr_prompt == 0) {
4995 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4996 ssh2_pkt_adduint32(ssh, s->num_prompts);
4998 if (s->need_pw) { /* only add pw if we just got one! */
4999 ssh2_pkt_addstring(ssh, s->password);
5000 memset(s->password, 0, sizeof(s->password));
5003 if (s->curr_prompt >= s->num_prompts) {
5007 * If there are prompts remaining, we set
5008 * `gotit' so that we won't attempt to get
5009 * another packet. Then we go back round the
5010 * loop and will end up retrieving another
5011 * prompt out of the existing packet. Funky or
5016 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5018 c_write_str(ssh, "No supported authentication methods"
5019 " left to try!\r\n");
5020 logevent("No supported authentications offered."
5022 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5023 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5024 ssh2_pkt_addstring(ssh, "No supported authentication"
5025 " methods available");
5026 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5028 ssh->state = SSH_STATE_CLOSED;
5032 } while (!s->we_are_in);
5035 * Now we're authenticated for the connection protocol. The
5036 * connection protocol will automatically have started at this
5037 * point; there's no need to send SERVICE_REQUEST.
5041 * So now create a channel with a session in it.
5043 ssh->channels = newtree234(ssh_channelcmp);
5044 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5045 ssh->mainchan->ssh = ssh;
5046 ssh->mainchan->localid = alloc_channel_id(ssh);
5047 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5048 ssh2_pkt_addstring(ssh, "session");
5049 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5050 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5051 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5052 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5054 crWaitUntilV(ispkt);
5055 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5056 bombout((ssh,"Server refused to open a session"));
5058 /* FIXME: error data comes back in FAILURE packet */
5060 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5061 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5064 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5065 ssh->mainchan->type = CHAN_MAINSESSION;
5066 ssh->mainchan->closes = 0;
5067 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5068 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5069 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5070 add234(ssh->channels, ssh->mainchan);
5071 logevent("Opened channel for session");
5074 * Potentially enable X11 forwarding.
5076 if (cfg.x11_forward) {
5077 char proto[20], data[64];
5078 logevent("Requesting X11 forwarding");
5079 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5080 data, sizeof(data));
5081 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5082 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5083 ssh2_pkt_addstring(ssh, "x11-req");
5084 ssh2_pkt_addbool(ssh, 1); /* want reply */
5085 ssh2_pkt_addbool(ssh, 0); /* many connections */
5086 ssh2_pkt_addstring(ssh, proto);
5087 ssh2_pkt_addstring(ssh, data);
5088 ssh2_pkt_adduint32(ssh, x11_get_screen_number(cfg.x11_display));
5092 crWaitUntilV(ispkt);
5093 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5094 unsigned i = ssh2_pkt_getuint32(ssh);
5095 struct ssh_channel *c;
5096 c = find234(ssh->channels, &i, ssh_channelfind);
5098 continue; /* nonexistent channel */
5099 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5101 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5103 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5104 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5105 bombout((ssh,"Unexpected response to X11 forwarding request:"
5106 " packet type %d", ssh->pktin.type));
5109 logevent("X11 forwarding refused");
5111 logevent("X11 forwarding enabled");
5112 ssh->X11_fwd_enabled = TRUE;
5117 * Enable port forwardings.
5122 int sport,dport,sserv,dserv;
5123 char sports[256], dports[256], saddr[256], host[256];
5125 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5126 /* Add port forwardings. */
5127 ssh->portfwd_strptr = cfg.portfwd;
5128 while (*ssh->portfwd_strptr) {
5129 type = *ssh->portfwd_strptr++;
5132 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5133 if (*ssh->portfwd_strptr == ':') {
5135 * We've seen a colon in the middle of the
5136 * source port number. This means that
5137 * everything we've seen until now is the
5138 * source _address_, so we'll move it into
5139 * saddr and start sports from the beginning
5142 ssh->portfwd_strptr++;
5144 strcpy(saddr, sports);
5147 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5150 if (*ssh->portfwd_strptr == '\t')
5151 ssh->portfwd_strptr++;
5153 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5154 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5157 if (*ssh->portfwd_strptr == ':')
5158 ssh->portfwd_strptr++;
5160 while (*ssh->portfwd_strptr) {
5161 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5164 ssh->portfwd_strptr++;
5165 dport = atoi(dports);
5169 dport = net_service_lookup(dports);
5171 logeventf(ssh, "Service lookup failed for destination"
5172 " port \"%s\"", dports);
5175 sport = atoi(sports);
5179 sport = net_service_lookup(sports);
5181 logeventf(ssh, "Service lookup failed for source"
5182 " port \"%s\"", sports);
5185 if (sport && dport) {
5187 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5189 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5190 " forwarding to %s:%.*s%.*s%d%.*s",
5191 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5192 (int)(*saddr?1:0), ":",
5193 (int)(sserv ? strlen(sports) : 0), sports,
5194 sserv, "(", sport, sserv, ")",
5196 (int)(dserv ? strlen(dports) : 0), dports,
5197 dserv, "(", dport, dserv, ")");
5199 struct ssh_rportfwd *pf;
5200 pf = smalloc(sizeof(*pf));
5201 strcpy(pf->dhost, host);
5204 if (add234(ssh->rportfwds, pf) != pf) {
5205 logeventf(ssh, "Duplicate remote port forwarding"
5206 " to %s:%d", host, dport);
5209 logeventf(ssh, "Requesting remote port "
5210 "%.*s%.*s%.*s%.*s%d%.*s"
5211 " forward to %s:%.*s%.*s%d%.*s",
5212 (int)(*saddr?strlen(saddr):0),
5214 (int)(*saddr?1:0), ":",
5215 (int)(sserv ? strlen(sports) : 0), sports,
5216 sserv, "(", sport, sserv, ")",
5218 (int)(dserv ? strlen(dports) : 0), dports,
5219 dserv, "(", dport, dserv, ")");
5220 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5221 ssh2_pkt_addstring(ssh, "tcpip-forward");
5222 ssh2_pkt_addbool(ssh, 1);/* want reply */
5224 ssh2_pkt_addstring(ssh, saddr);
5225 if (cfg.rport_acceptall)
5226 ssh2_pkt_addstring(ssh, "0.0.0.0");
5228 ssh2_pkt_addstring(ssh, "127.0.0.1");
5229 ssh2_pkt_adduint32(ssh, sport);
5233 crWaitUntilV(ispkt);
5234 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5235 unsigned i = ssh2_pkt_getuint32(ssh);
5236 struct ssh_channel *c;
5237 c = find234(ssh->channels, &i, ssh_channelfind);
5239 continue;/* nonexistent channel */
5240 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5242 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5244 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5245 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5246 bombout((ssh,"Unexpected response to port "
5247 "forwarding request: packet type %d",
5251 logevent("Server refused this port forwarding");
5253 logevent("Remote port forwarding enabled");
5262 * Potentially enable agent forwarding.
5264 if (cfg.agentfwd && agent_exists()) {
5265 logevent("Requesting OpenSSH-style agent forwarding");
5266 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5267 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5268 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5269 ssh2_pkt_addbool(ssh, 1); /* want reply */
5273 crWaitUntilV(ispkt);
5274 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5275 unsigned i = ssh2_pkt_getuint32(ssh);
5276 struct ssh_channel *c;
5277 c = find234(ssh->channels, &i, ssh_channelfind);
5279 continue; /* nonexistent channel */
5280 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5282 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5284 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5285 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5286 bombout((ssh,"Unexpected response to agent forwarding request:"
5287 " packet type %d", ssh->pktin.type));
5290 logevent("Agent forwarding refused");
5292 logevent("Agent forwarding enabled");
5293 ssh->agentfwd_enabled = TRUE;
5298 * Now allocate a pty for the session.
5301 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5302 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5303 ssh2_pkt_addstring(ssh, "pty-req");
5304 ssh2_pkt_addbool(ssh, 1); /* want reply */
5305 ssh2_pkt_addstring(ssh, cfg.termtype);
5306 ssh2_pkt_adduint32(ssh, ssh->term_width);
5307 ssh2_pkt_adduint32(ssh, ssh->term_height);
5308 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5309 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5310 ssh2_pkt_addstring_start(ssh);
5311 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5313 ssh->state = SSH_STATE_INTERMED;
5316 crWaitUntilV(ispkt);
5317 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5318 unsigned i = ssh2_pkt_getuint32(ssh);
5319 struct ssh_channel *c;
5320 c = find234(ssh->channels, &i, ssh_channelfind);
5322 continue; /* nonexistent channel */
5323 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5325 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5327 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5328 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5329 bombout((ssh,"Unexpected response to pty request:"
5330 " packet type %d", ssh->pktin.type));
5333 c_write_str(ssh, "Server refused to allocate pty\r\n");
5334 ssh->editing = ssh->echoing = 1;
5336 logevent("Allocated pty");
5339 ssh->editing = ssh->echoing = 1;
5343 * Start a shell or a remote command. We may have to attempt
5344 * this twice if the config data has provided a second choice
5351 if (ssh->fallback_cmd) {
5352 subsys = cfg.ssh_subsys2;
5353 cmd = cfg.remote_cmd_ptr2;
5355 subsys = cfg.ssh_subsys;
5356 cmd = cfg.remote_cmd_ptr;
5359 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5360 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5362 ssh2_pkt_addstring(ssh, "subsystem");
5363 ssh2_pkt_addbool(ssh, 1); /* want reply */
5364 ssh2_pkt_addstring(ssh, cmd);
5366 ssh2_pkt_addstring(ssh, "exec");
5367 ssh2_pkt_addbool(ssh, 1); /* want reply */
5368 ssh2_pkt_addstring(ssh, cmd);
5370 ssh2_pkt_addstring(ssh, "shell");
5371 ssh2_pkt_addbool(ssh, 1); /* want reply */
5375 crWaitUntilV(ispkt);
5376 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5377 unsigned i = ssh2_pkt_getuint32(ssh);
5378 struct ssh_channel *c;
5379 c = find234(ssh->channels, &i, ssh_channelfind);
5381 continue; /* nonexistent channel */
5382 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5384 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5385 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5386 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5387 bombout((ssh,"Unexpected response to shell/command request:"
5388 " packet type %d", ssh->pktin.type));
5392 * We failed to start the command. If this is the
5393 * fallback command, we really are finished; if it's
5394 * not, and if the fallback command exists, try falling
5395 * back to it before complaining.
5397 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5398 logevent("Primary command failed; attempting fallback");
5399 ssh->fallback_cmd = TRUE;
5402 bombout((ssh,"Server refused to start a shell/command"));
5405 logevent("Started a shell/command");
5410 ssh->state = SSH_STATE_SESSION;
5411 if (ssh->size_needed)
5412 ssh_size(ssh, ssh->term_width, ssh->term_height);
5413 if (ssh->eof_needed)
5414 ssh_special(ssh, TS_EOF);
5420 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5424 s->try_send = FALSE;
5426 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5427 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5430 unsigned i = ssh2_pkt_getuint32(ssh);
5431 struct ssh_channel *c;
5432 c = find234(ssh->channels, &i, ssh_channelfind);
5434 continue; /* nonexistent channel */
5435 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5436 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5437 continue; /* extended but not stderr */
5438 ssh2_pkt_getstring(ssh, &data, &length);
5441 c->v.v2.locwindow -= length;
5443 case CHAN_MAINSESSION:
5445 from_backend(ssh->frontend, ssh->pktin.type ==
5446 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5450 bufsize = x11_send(c->u.x11.s, data, length);
5453 bufsize = pfd_send(c->u.pfd.s, data, length);
5456 while (length > 0) {
5457 if (c->u.a.lensofar < 4) {
5458 int l = min(4 - c->u.a.lensofar, length);
5459 memcpy(c->u.a.msglen + c->u.a.lensofar,
5463 c->u.a.lensofar += l;
5465 if (c->u.a.lensofar == 4) {
5467 4 + GET_32BIT(c->u.a.msglen);
5468 c->u.a.message = smalloc(c->u.a.totallen);
5469 memcpy(c->u.a.message, c->u.a.msglen, 4);
5471 if (c->u.a.lensofar >= 4 && length > 0) {
5473 min(c->u.a.totallen - c->u.a.lensofar,
5475 memcpy(c->u.a.message + c->u.a.lensofar,
5479 c->u.a.lensofar += l;
5481 if (c->u.a.lensofar == c->u.a.totallen) {
5482 void *reply, *sentreply;
5484 agent_query(c->u.a.message,
5485 c->u.a.totallen, &reply,
5490 /* Fake SSH_AGENT_FAILURE. */
5491 sentreply = "\0\0\0\1\5";
5494 ssh2_add_channel_data(c, sentreply, replylen);
5498 sfree(c->u.a.message);
5499 c->u.a.lensofar = 0;
5506 * If we are not buffering too much data,
5507 * enlarge the window again at the remote side.
5509 if (bufsize < OUR_V2_WINSIZE)
5510 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5512 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5513 unsigned i = ssh2_pkt_getuint32(ssh);
5514 struct ssh_channel *c;
5516 c = find234(ssh->channels, &i, ssh_channelfind);
5518 continue; /* nonexistent channel */
5520 if (c->type == CHAN_X11) {
5522 * Remote EOF on an X11 channel means we should
5523 * wrap up and close the channel ourselves.
5525 x11_close(c->u.x11.s);
5527 } else if (c->type == CHAN_AGENT) {
5529 } else if (c->type == CHAN_SOCKDATA) {
5530 pfd_close(c->u.pfd.s);
5533 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5534 unsigned i = ssh2_pkt_getuint32(ssh);
5535 struct ssh_channel *c;
5537 c = find234(ssh->channels, &i, ssh_channelfind);
5538 if (!c || ((int)c->remoteid) == -1) {
5539 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5540 c ? "half-open" : "nonexistent", i));
5542 /* Do pre-close processing on the channel. */
5544 case CHAN_MAINSESSION:
5545 break; /* nothing to see here, move along */
5547 if (c->u.x11.s != NULL)
5548 x11_close(c->u.x11.s);
5555 if (c->u.pfd.s != NULL)
5556 pfd_close(c->u.pfd.s);
5560 if (c->closes == 0) {
5561 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5562 ssh2_pkt_adduint32(ssh, c->remoteid);
5565 del234(ssh->channels, c);
5566 bufchain_clear(&c->v.v2.outbuffer);
5570 * See if that was the last channel left open.
5572 if (count234(ssh->channels) == 0) {
5575 * We used to send SSH_MSG_DISCONNECT here,
5576 * because I'd believed that _every_ conforming
5577 * SSH2 connection had to end with a disconnect
5578 * being sent by at least one side; apparently
5579 * I was wrong and it's perfectly OK to
5580 * unceremoniously slam the connection shut
5581 * when you're done, and indeed OpenSSH feels
5582 * this is more polite than sending a
5583 * DISCONNECT. So now we don't.
5585 logevent("All channels closed. Disconnecting");
5586 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5587 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5588 ssh2_pkt_addstring(ssh, "All open channels closed");
5589 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5592 ssh->state = SSH_STATE_CLOSED;
5595 continue; /* remote sends close; ignore (FIXME) */
5596 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5597 unsigned i = ssh2_pkt_getuint32(ssh);
5598 struct ssh_channel *c;
5599 c = find234(ssh->channels, &i, ssh_channelfind);
5601 continue; /* nonexistent channel */
5602 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5604 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5605 unsigned i = ssh2_pkt_getuint32(ssh);
5606 struct ssh_channel *c;
5607 c = find234(ssh->channels, &i, ssh_channelfind);
5609 continue; /* nonexistent channel */
5610 if (c->type != CHAN_SOCKDATA_DORMANT)
5611 continue; /* dunno why they're confirming this */
5612 c->remoteid = ssh2_pkt_getuint32(ssh);
5613 c->type = CHAN_SOCKDATA;
5614 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5615 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5617 pfd_confirm(c->u.pfd.s);
5620 * We have a pending close on this channel,
5621 * which we decided on before the server acked
5622 * the channel open. So now we know the
5623 * remoteid, we can close it again.
5625 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5626 ssh2_pkt_adduint32(ssh, c->remoteid);
5629 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5630 unsigned i = ssh2_pkt_getuint32(ssh);
5631 struct ssh_channel *c;
5632 c = find234(ssh->channels, &i, ssh_channelfind);
5634 continue; /* nonexistent channel */
5635 if (c->type != CHAN_SOCKDATA_DORMANT)
5636 continue; /* dunno why they're failing this */
5638 logevent("Forwarded connection refused by server");
5640 pfd_close(c->u.pfd.s);
5642 del234(ssh->channels, c);
5644 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5647 int typelen, want_reply;
5648 struct ssh_channel *c;
5650 localid = ssh2_pkt_getuint32(ssh);
5651 ssh2_pkt_getstring(ssh, &type, &typelen);
5652 want_reply = ssh2_pkt_getbool(ssh);
5655 * First, check that the channel exists. Otherwise,
5656 * we can instantly disconnect with a rude message.
5658 c = find234(ssh->channels, &localid, ssh_channelfind);
5661 sprintf(buf, "Received channel request for nonexistent"
5662 " channel %d", localid);
5664 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5665 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5666 ssh2_pkt_addstring(ssh, buf);
5667 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5669 connection_fatal("%s", buf);
5670 ssh->state = SSH_STATE_CLOSED;
5675 * Having got the channel number, we now look at
5676 * the request type string to see if it's something
5679 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5680 c == ssh->mainchan) {
5681 /* We recognise "exit-status" on the primary channel. */
5683 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5684 sprintf(buf, "Server sent command exit status %d",
5688 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5689 ssh2_pkt_adduint32(ssh, c->remoteid);
5694 * This is a channel request we don't know
5695 * about, so we now either ignore the request
5696 * or respond with CHANNEL_FAILURE, depending
5700 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5701 ssh2_pkt_adduint32(ssh, c->remoteid);
5705 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5707 int typelen, want_reply;
5709 ssh2_pkt_getstring(ssh, &type, &typelen);
5710 want_reply = ssh2_pkt_getbool(ssh);
5713 * We currently don't support any global requests
5714 * at all, so we either ignore the request or
5715 * respond with REQUEST_FAILURE, depending on
5719 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5722 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5726 struct ssh_channel *c;
5727 unsigned remid, winsize, pktsize;
5728 ssh2_pkt_getstring(ssh, &type, &typelen);
5729 c = smalloc(sizeof(struct ssh_channel));
5732 remid = ssh2_pkt_getuint32(ssh);
5733 winsize = ssh2_pkt_getuint32(ssh);
5734 pktsize = ssh2_pkt_getuint32(ssh);
5736 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5737 if (!ssh->X11_fwd_enabled)
5738 error = "X11 forwarding is not enabled";
5739 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5740 ssh->x11auth) != NULL) {
5741 error = "Unable to open an X11 connection";
5745 } else if (typelen == 15 &&
5746 !memcmp(type, "forwarded-tcpip", 15)) {
5747 struct ssh_rportfwd pf, *realpf;
5750 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5751 pf.sport = ssh2_pkt_getuint32(ssh);
5752 realpf = find234(ssh->rportfwds, &pf, NULL);
5753 if (realpf == NULL) {
5754 error = "Remote port is not recognised";
5756 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5758 logeventf(ssh, "Received remote port open request"
5759 " for %s:%d", realpf->dhost, realpf->dport);
5761 logeventf(ssh, "Port open failed: %s", e);
5762 error = "Port open failed";
5764 logevent("Forwarded port opened successfully");
5765 c->type = CHAN_SOCKDATA;
5768 } else if (typelen == 22 &&
5769 !memcmp(type, "auth-agent@openssh.com", 3)) {
5770 if (!ssh->agentfwd_enabled)
5771 error = "Agent forwarding is not enabled";
5773 c->type = CHAN_AGENT; /* identify channel type */
5774 c->u.a.lensofar = 0;
5777 error = "Unsupported channel type requested";
5780 c->remoteid = remid;
5782 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5783 ssh2_pkt_adduint32(ssh, c->remoteid);
5784 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5785 ssh2_pkt_addstring(ssh, error);
5786 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5790 c->localid = alloc_channel_id(ssh);
5792 c->v.v2.locwindow = OUR_V2_WINSIZE;
5793 c->v.v2.remwindow = winsize;
5794 c->v.v2.remmaxpkt = pktsize;
5795 bufchain_init(&c->v.v2.outbuffer);
5796 add234(ssh->channels, c);
5797 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5798 ssh2_pkt_adduint32(ssh, c->remoteid);
5799 ssh2_pkt_adduint32(ssh, c->localid);
5800 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5801 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5805 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5810 * We have spare data. Add it to the channel buffer.
5812 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5817 struct ssh_channel *c;
5819 * Try to send data on all channels if we can.
5821 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5822 int bufsize = ssh2_try_send(c);
5825 case CHAN_MAINSESSION:
5826 /* stdin need not receive an unthrottle
5827 * notification since it will be polled */
5830 x11_unthrottle(c->u.x11.s);
5833 /* agent sockets are request/response and need no
5834 * buffer management */
5837 pfd_unthrottle(c->u.pfd.s);
5849 * Handle the top-level SSH2 protocol.
5851 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5853 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5855 do_ssh2_authconn(ssh, in, inlen, ispkt);
5859 * Called to set up the connection.
5861 * Returns an error message, or NULL on success.
5863 static char *ssh_init(void *frontend_handle, void **backend_handle,
5864 char *host, int port, char **realhost, int nodelay)
5869 ssh = smalloc(sizeof(*ssh));
5872 ssh->v1_cipher_ctx = NULL;
5873 ssh->crcda_ctx = NULL;
5874 ssh->cscipher = NULL;
5875 ssh->cs_cipher_ctx = NULL;
5876 ssh->sccipher = NULL;
5877 ssh->sc_cipher_ctx = NULL;
5879 ssh->cs_mac_ctx = NULL;
5881 ssh->sc_mac_ctx = NULL;
5883 ssh->cs_comp_ctx = NULL;
5885 ssh->sc_comp_ctx = NULL;
5887 ssh->hostkey = NULL;
5889 ssh->state = SSH_STATE_PREPACKET;
5890 ssh->size_needed = FALSE;
5891 ssh->eof_needed = FALSE;
5895 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5896 ssh->pktin = ssh->pktout = empty;
5898 ssh->deferred_send_data = NULL;
5899 ssh->deferred_len = 0;
5900 ssh->deferred_size = 0;
5901 ssh->fallback_cmd = 0;
5903 ssh->x11auth = NULL;
5904 ssh->v1_compressing = FALSE;
5905 ssh->v2_outgoing_sequence = 0;
5906 ssh->ssh1_rdpkt_crstate = 0;
5907 ssh->ssh2_rdpkt_crstate = 0;
5908 ssh->do_ssh_init_crstate = 0;
5909 ssh->ssh_gotdata_crstate = 0;
5910 ssh->ssh1_protocol_crstate = 0;
5911 ssh->do_ssh1_login_crstate = 0;
5912 ssh->do_ssh2_transport_crstate = 0;
5913 ssh->do_ssh2_authconn_crstate = 0;
5914 ssh->do_ssh_init_state = NULL;
5915 ssh->do_ssh1_login_state = NULL;
5916 ssh->do_ssh2_transport_state = NULL;
5917 ssh->do_ssh2_authconn_state = NULL;
5918 ssh->mainchan = NULL;
5919 ssh->throttled_all = 0;
5920 ssh->v1_stdout_throttling = 0;
5922 *backend_handle = ssh;
5925 if (crypto_startup() == 0)
5926 return "Microsoft high encryption pack not installed!";
5929 ssh->frontend = frontend_handle;
5930 ssh->term_width = cfg.width;
5931 ssh->term_height = cfg.height;
5936 ssh->v1_throttle_count = 0;
5937 ssh->overall_bufsize = 0;
5938 ssh->fallback_cmd = 0;
5940 p = connect_to_host(ssh, host, port, realhost, nodelay);
5948 * Called to send data down the Telnet connection.
5950 static int ssh_send(void *handle, char *buf, int len)
5952 Ssh ssh = (Ssh) handle;
5954 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5957 ssh->protocol(ssh, buf, len, 0);
5959 return ssh_sendbuffer(ssh);
5963 * Called to query the current amount of buffered stdin data.
5965 static int ssh_sendbuffer(void *handle)
5967 Ssh ssh = (Ssh) handle;
5970 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5974 * If the SSH socket itself has backed up, add the total backup
5975 * size on that to any individual buffer on the stdin channel.
5978 if (ssh->throttled_all)
5979 override_value = ssh->overall_bufsize;
5981 if (ssh->version == 1) {
5982 return override_value;
5983 } else if (ssh->version == 2) {
5984 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5985 return override_value;
5987 return (override_value +
5988 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5995 * Called to set the size of the window from SSH's POV.
5997 static void ssh_size(void *handle, int width, int height)
5999 Ssh ssh = (Ssh) handle;
6001 ssh->term_width = width;
6002 ssh->term_height = height;
6004 switch (ssh->state) {
6005 case SSH_STATE_BEFORE_SIZE:
6006 case SSH_STATE_PREPACKET:
6007 case SSH_STATE_CLOSED:
6008 break; /* do nothing */
6009 case SSH_STATE_INTERMED:
6010 ssh->size_needed = TRUE; /* buffer for later */
6012 case SSH_STATE_SESSION:
6014 if (ssh->version == 1) {
6015 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6016 PKT_INT, ssh->term_height,
6017 PKT_INT, ssh->term_width,
6018 PKT_INT, 0, PKT_INT, 0, PKT_END);
6020 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6021 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6022 ssh2_pkt_addstring(ssh, "window-change");
6023 ssh2_pkt_addbool(ssh, 0);
6024 ssh2_pkt_adduint32(ssh, ssh->term_width);
6025 ssh2_pkt_adduint32(ssh, ssh->term_height);
6026 ssh2_pkt_adduint32(ssh, 0);
6027 ssh2_pkt_adduint32(ssh, 0);
6036 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6037 * can send an EOF and collect resulting output (e.g. `plink
6040 static void ssh_special(void *handle, Telnet_Special code)
6042 Ssh ssh = (Ssh) handle;
6044 if (code == TS_EOF) {
6045 if (ssh->state != SSH_STATE_SESSION) {
6047 * Buffer the EOF in case we are pre-SESSION, so we can
6048 * send it as soon as we reach SESSION.
6051 ssh->eof_needed = TRUE;
6054 if (ssh->version == 1) {
6055 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6057 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6058 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6061 logevent("Sent EOF message");
6062 } else if (code == TS_PING) {
6063 if (ssh->state == SSH_STATE_CLOSED
6064 || ssh->state == SSH_STATE_PREPACKET) return;
6065 if (ssh->version == 1) {
6066 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6067 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6069 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6070 ssh2_pkt_addstring_start(ssh);
6078 void *new_sock_channel(void *handle, Socket s)
6080 Ssh ssh = (Ssh) handle;
6081 struct ssh_channel *c;
6082 c = smalloc(sizeof(struct ssh_channel));
6086 c->remoteid = -1; /* to be set when open confirmed */
6087 c->localid = alloc_channel_id(ssh);
6089 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6091 bufchain_init(&c->v.v2.outbuffer);
6092 add234(ssh->channels, c);
6098 * This is called when stdout/stderr (the entity to which
6099 * from_backend sends data) manages to clear some backlog.
6101 void ssh_unthrottle(void *handle, int bufsize)
6103 Ssh ssh = (Ssh) handle;
6104 if (ssh->version == 1) {
6105 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6106 ssh->v1_stdout_throttling = 0;
6107 ssh1_throttle(ssh, -1);
6110 if (ssh->mainchan && ssh->mainchan->closes == 0)
6111 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6115 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6117 struct ssh_channel *c = (struct ssh_channel *)channel;
6120 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6122 if (ssh->version == 1) {
6123 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6124 PKT_INT, c->localid,
6127 //PKT_STR, <org:orgport>,
6130 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6131 ssh2_pkt_addstring(ssh, "direct-tcpip");
6132 ssh2_pkt_adduint32(ssh, c->localid);
6133 c->v.v2.locwindow = OUR_V2_WINSIZE;
6134 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6135 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6136 ssh2_pkt_addstring(ssh, hostname);
6137 ssh2_pkt_adduint32(ssh, port);
6139 * We make up values for the originator data; partly it's
6140 * too much hassle to keep track, and partly I'm not
6141 * convinced the server should be told details like that
6142 * about my local network configuration.
6144 ssh2_pkt_addstring(ssh, "client-side-connection");
6145 ssh2_pkt_adduint32(ssh, 0);
6151 static Socket ssh_socket(void *handle)
6153 Ssh ssh = (Ssh) handle;
6157 static int ssh_sendok(void *handle)
6159 Ssh ssh = (Ssh) handle;
6160 return ssh->send_ok;
6163 static int ssh_ldisc(void *handle, int option)
6165 Ssh ssh = (Ssh) handle;
6166 if (option == LD_ECHO)
6167 return ssh->echoing;
6168 if (option == LD_EDIT)
6169 return ssh->editing;
6173 static void ssh_provide_ldisc(void *handle, void *ldisc)
6175 Ssh ssh = (Ssh) handle;
6179 static void ssh_provide_logctx(void *handle, void *logctx)
6181 Ssh ssh = (Ssh) handle;
6182 ssh->logctx = logctx;
6185 static int ssh_return_exitcode(void *handle)
6187 Ssh ssh = (Ssh) handle;
6188 return ssh->exitcode;
6192 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6193 * that fails. This variable is the means by which scp.c can reach
6194 * into the SSH code and find out which one it got.
6196 extern int ssh_fallback_cmd(void *handle)
6198 Ssh ssh = (Ssh) handle;
6199 return ssh->fallback_cmd;
6202 Backend ssh_backend = {
6209 ssh_return_exitcode,