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);
301 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
302 extern char *pfd_addforward(char *desthost, int destport, int port,
304 extern void pfd_close(Socket s);
305 extern int pfd_send(Socket s, char *data, int len);
306 extern void pfd_confirm(Socket s);
307 extern void pfd_unthrottle(Socket s);
308 extern void pfd_override_throttle(Socket s, int enable);
310 static void ssh2_pkt_init(Ssh, int pkt_type);
311 static void ssh2_pkt_addbool(Ssh, unsigned char value);
312 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
313 static void ssh2_pkt_addstring_start(Ssh);
314 static void ssh2_pkt_addstring_str(Ssh, char *data);
315 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
316 static void ssh2_pkt_addstring(Ssh, char *data);
317 static char *ssh2_mpint_fmt(Bignum b, int *len);
318 static void ssh2_pkt_addmp(Ssh, Bignum b);
319 static int ssh2_pkt_construct(Ssh);
320 static void ssh2_pkt_send(Ssh);
323 * Buffer management constants. There are several of these for
324 * various different purposes:
326 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
327 * on a local data stream before we throttle the whole SSH
328 * connection (in SSH1 only). Throttling the whole connection is
329 * pretty drastic so we set this high in the hope it won't
332 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
333 * on the SSH connection itself before we defensively throttle
334 * _all_ local data streams. This is pretty drastic too (though
335 * thankfully unlikely in SSH2 since the window mechanism should
336 * ensure that the server never has any need to throttle its end
337 * of the connection), so we set this high as well.
339 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
343 #define SSH1_BUFFER_LIMIT 32768
344 #define SSH_MAX_BACKLOG 32768
345 #define OUR_V2_WINSIZE 16384
347 const static struct ssh_kex *kex_algs[] = {
348 &ssh_diffiehellman_gex,
352 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
354 static void *nullmac_make_context(void)
358 static void nullmac_free_context(void *handle)
361 static void nullmac_key(void *handle, unsigned char *key)
364 static void nullmac_generate(void *handle, unsigned char *blk, int len,
368 static int nullmac_verify(void *handle, unsigned char *blk, int len,
373 const static struct ssh_mac ssh_mac_none = {
374 nullmac_make_context, nullmac_free_context, nullmac_key,
375 nullmac_generate, nullmac_verify, "none", 0
377 const static struct ssh_mac *macs[] = {
378 &ssh_sha1, &ssh_md5, &ssh_mac_none
380 const static struct ssh_mac *buggymacs[] = {
381 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
384 static void *ssh_comp_none_init(void)
388 static void ssh_comp_none_cleanup(void *handle)
391 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
392 unsigned char **outblock, int *outlen)
396 static int ssh_comp_none_disable(void *handle)
400 const static struct ssh_compress ssh_comp_none = {
402 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
403 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
404 ssh_comp_none_disable, NULL
406 extern const struct ssh_compress ssh_zlib;
407 const static struct ssh_compress *compressions[] = {
408 &ssh_zlib, &ssh_comp_none
411 enum { /* channel types */
416 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
420 * 2-3-4 tree storing channels.
423 Ssh ssh; /* pointer back to main context */
424 unsigned remoteid, localid;
427 * In SSH1, this value contains four bits:
429 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
430 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
431 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
432 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
434 * A channel is completely finished with when all four bits are set.
438 struct ssh1_data_channel {
441 struct ssh2_data_channel {
443 unsigned remwindow, remmaxpkt;
448 struct ssh_agent_channel {
449 unsigned char *message;
450 unsigned char msglen[4];
451 int lensofar, totallen;
453 struct ssh_x11_channel {
456 struct ssh_pfd_channel {
463 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
464 * 2 use this structure in different ways, reflecting SSH 2's
465 * altogether saner approach to port forwarding.
467 * In SSH 1, you arrange a remote forwarding by sending the server
468 * the remote port number, and the local destination host:port.
469 * When a connection comes in, the server sends you back that
470 * host:port pair, and you connect to it. This is a ready-made
471 * security hole if you're not on the ball: a malicious server
472 * could send you back _any_ host:port pair, so if you trustingly
473 * connect to the address it gives you then you've just opened the
474 * entire inside of your corporate network just by connecting
475 * through it to a dodgy SSH server. Hence, we must store a list of
476 * host:port pairs we _are_ trying to forward to, and reject a
477 * connection request from the server if it's not in the list.
479 * In SSH 2, each side of the connection minds its own business and
480 * doesn't send unnecessary information to the other. You arrange a
481 * remote forwarding by sending the server just the remote port
482 * number. When a connection comes in, the server tells you which
483 * of its ports was connected to; and _you_ have to remember what
484 * local host:port pair went with that port number.
486 * Hence: in SSH 1 this structure stores host:port pairs we intend
487 * to allow connections to, and is indexed by those host:port
488 * pairs. In SSH 2 it stores a mapping from source port to
489 * destination host:port pair, and is indexed by source port.
491 struct ssh_rportfwd {
492 unsigned sport, dport;
505 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
506 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
507 static void ssh_size(void *handle, int width, int height);
508 static void ssh_special(void *handle, Telnet_Special);
509 static int ssh2_try_send(struct ssh_channel *c);
510 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
511 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
512 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
513 static int ssh_sendbuffer(void *handle);
515 struct rdpkt1_state_tag {
516 long len, pad, biglen, to_read;
517 unsigned long realcrc, gotcrc;
523 struct rdpkt2_state_tag {
524 long len, pad, payload, packetlen, maclen;
527 unsigned long incoming_sequence;
531 const struct plug_function_table *fn;
532 /* the above field _must_ be first in the structure */
534 SHA_State exhash, exhashbase;
541 unsigned char session_key[32];
543 int v1_remote_protoflags;
544 int v1_local_protoflags;
545 int agentfwd_enabled;
548 const struct ssh_cipher *cipher;
551 const struct ssh2_cipher *cscipher, *sccipher;
552 void *cs_cipher_ctx, *sc_cipher_ctx;
553 const struct ssh_mac *csmac, *scmac;
554 void *cs_mac_ctx, *sc_mac_ctx;
555 const struct ssh_compress *cscomp, *sccomp;
556 void *cs_comp_ctx, *sc_comp_ctx;
557 const struct ssh_kex *kex;
558 const struct ssh_signkey *hostkey;
559 unsigned char v2_session_id[20];
565 int echoing, editing;
569 int term_width, term_height;
571 tree234 *channels; /* indexed by local id */
572 struct ssh_channel *mainchan; /* primary session channel */
579 SSH_STATE_BEFORE_SIZE,
585 int size_needed, eof_needed;
588 struct Packet pktout;
589 unsigned char *deferred_send_data;
590 int deferred_len, deferred_size;
593 * Gross hack: pscp will try to start SFTP but fall back to
594 * scp1 if that fails. This variable is the means by which
595 * scp.c can reach into the SSH code and find out which one it
601 * Used for username and password input.
603 char *userpass_input_buffer;
604 int userpass_input_buflen;
605 int userpass_input_bufpos;
606 int userpass_input_echo;
608 char *portfwd_strptr;
614 int v1_throttle_count;
617 int v1_stdout_throttling;
618 int v2_outgoing_sequence;
620 int ssh1_rdpkt_crstate;
621 int ssh2_rdpkt_crstate;
622 int do_ssh_init_crstate;
623 int ssh_gotdata_crstate;
624 int ssh1_protocol_crstate;
625 int do_ssh1_login_crstate;
626 int do_ssh2_transport_crstate;
627 int do_ssh2_authconn_crstate;
629 void *do_ssh_init_state;
630 void *do_ssh1_login_state;
631 void *do_ssh2_transport_state;
632 void *do_ssh2_authconn_state;
634 struct rdpkt1_state_tag rdpkt1_state;
635 struct rdpkt2_state_tag rdpkt2_state;
637 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
638 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
641 #define logevent(s) do { \
642 logevent(ssh->frontend, s); \
643 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) { \
644 fprintf(stderr, "%s\n", s); \
649 /* logevent, only printf-formatted. */
650 void logeventf(Ssh ssh, char *fmt, ...)
656 buf = dupvprintf(fmt, ap);
659 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) {
660 fprintf(stderr, "%s\n", buf);
666 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
667 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
668 logeventf msg, connection_fatal msg )
670 static int ssh_channelcmp(void *av, void *bv)
672 struct ssh_channel *a = (struct ssh_channel *) av;
673 struct ssh_channel *b = (struct ssh_channel *) bv;
674 if (a->localid < b->localid)
676 if (a->localid > b->localid)
680 static int ssh_channelfind(void *av, void *bv)
682 unsigned *a = (unsigned *) av;
683 struct ssh_channel *b = (struct ssh_channel *) bv;
691 static int ssh_rportcmp_ssh1(void *av, void *bv)
693 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
694 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
696 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
697 return i < 0 ? -1 : +1;
698 if (a->dport > b->dport)
700 if (a->dport < b->dport)
705 static int ssh_rportcmp_ssh2(void *av, void *bv)
707 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
708 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
710 if (a->sport > b->sport)
712 if (a->sport < b->sport)
717 static int alloc_channel_id(Ssh ssh)
719 const unsigned CHANNEL_NUMBER_OFFSET = 256;
720 unsigned low, high, mid;
722 struct ssh_channel *c;
725 * First-fit allocation of channel numbers: always pick the
726 * lowest unused one. To do this, binary-search using the
727 * counted B-tree to find the largest channel ID which is in a
728 * contiguous sequence from the beginning. (Precisely
729 * everything in that sequence must have ID equal to its tree
730 * index plus CHANNEL_NUMBER_OFFSET.)
732 tsize = count234(ssh->channels);
736 while (high - low > 1) {
737 mid = (high + low) / 2;
738 c = index234(ssh->channels, mid);
739 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
740 low = mid; /* this one is fine */
742 high = mid; /* this one is past it */
745 * Now low points to either -1, or the tree index of the
746 * largest ID in the initial sequence.
749 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
750 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
752 return low + 1 + CHANNEL_NUMBER_OFFSET;
755 static void c_write(Ssh ssh, char *buf, int len)
757 if ((flags & FLAG_STDERR)) {
759 for (i = 0; i < len; i++)
761 fputc(buf[i], stderr);
764 from_backend(ssh->frontend, 1, buf, len);
767 static void c_write_untrusted(Ssh ssh, char *buf, int len)
770 for (i = 0; i < len; i++) {
772 c_write(ssh, "\r\n", 2);
773 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
774 c_write(ssh, buf + i, 1);
778 static void c_write_str(Ssh ssh, char *buf)
780 c_write(ssh, buf, strlen(buf));
784 * Collect incoming data in the incoming packet buffer.
785 * Decipher and verify the packet when it is completely read.
786 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
787 * Update the *data and *datalen variables.
788 * Return the additional nr of bytes needed, or 0 when
789 * a complete packet is available.
791 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
793 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
795 crBegin(ssh->ssh1_rdpkt_crstate);
800 ssh->pktin.length = 0;
802 for (st->i = st->len = 0; st->i < 4; st->i++) {
803 while ((*datalen) == 0)
805 st->len = (st->len << 8) + **data;
806 (*data)++, (*datalen)--;
809 st->pad = 8 - (st->len % 8);
810 st->biglen = st->len + st->pad;
811 ssh->pktin.length = st->len - 5;
813 if (ssh->pktin.maxlen < st->biglen) {
814 ssh->pktin.maxlen = st->biglen;
815 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
818 st->to_read = st->biglen;
819 st->p = ssh->pktin.data;
820 while (st->to_read > 0) {
821 st->chunk = st->to_read;
822 while ((*datalen) == 0)
823 crReturn(st->to_read);
824 if (st->chunk > (*datalen))
825 st->chunk = (*datalen);
826 memcpy(st->p, *data, st->chunk);
828 *datalen -= st->chunk;
830 st->to_read -= st->chunk;
833 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
835 bombout((ssh,"Network attack (CRC compensation) detected!"));
840 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
842 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
843 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
844 if (st->gotcrc != st->realcrc) {
845 bombout((ssh,"Incorrect CRC received on packet"));
849 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
851 if (ssh->v1_compressing) {
852 unsigned char *decompblk;
854 zlib_decompress_block(ssh->sc_comp_ctx,
855 ssh->pktin.body - 1, ssh->pktin.length + 1,
856 &decompblk, &decomplen);
858 if (ssh->pktin.maxlen < st->pad + decomplen) {
859 ssh->pktin.maxlen = st->pad + decomplen;
860 ssh->pktin.data = srealloc(ssh->pktin.data,
861 ssh->pktin.maxlen + APIEXTRA);
862 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
865 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
867 ssh->pktin.length = decomplen - 1;
870 ssh->pktin.type = ssh->pktin.body[-1];
873 log_packet(ssh->logctx,
874 PKT_INCOMING, ssh->pktin.type,
875 ssh1_pkt_type(ssh->pktin.type),
876 ssh->pktin.body, ssh->pktin.length);
878 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
879 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
880 ssh->pktin.type == SSH1_MSG_DEBUG ||
881 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
882 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
883 long stringlen = GET_32BIT(ssh->pktin.body);
884 if (stringlen + 4 != ssh->pktin.length) {
885 bombout((ssh,"Received data packet with bogus string length"));
890 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
891 /* log debug message */
893 int stringlen = GET_32BIT(ssh->pktin.body);
894 strcpy(buf, "Remote debug message: ");
897 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
898 buf[8 + stringlen] = '\0';
901 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
906 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
907 /* log reason code in disconnect message */
909 unsigned msglen = GET_32BIT(ssh->pktin.body);
911 strcpy(buf, "Remote sent disconnect: ");
912 nowlen = strlen(buf);
913 if (msglen > sizeof(buf) - nowlen - 1)
914 msglen = sizeof(buf) - nowlen - 1;
915 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
916 buf[nowlen + msglen] = '\0';
917 /* logevent(buf); (this is now done within the bombout macro) */
918 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
925 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
927 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
929 crBegin(ssh->ssh2_rdpkt_crstate);
933 ssh->pktin.length = 0;
935 st->cipherblk = ssh->sccipher->blksize;
938 if (st->cipherblk < 8)
941 if (ssh->pktin.maxlen < st->cipherblk) {
942 ssh->pktin.maxlen = st->cipherblk;
943 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
947 * Acquire and decrypt the first block of the packet. This will
948 * contain the length and padding details.
950 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
951 while ((*datalen) == 0)
952 crReturn(st->cipherblk - st->i);
953 ssh->pktin.data[st->i] = *(*data)++;
958 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
959 ssh->pktin.data, st->cipherblk);
962 * Now get the length and padding figures.
964 st->len = GET_32BIT(ssh->pktin.data);
965 st->pad = ssh->pktin.data[4];
968 * _Completely_ silly lengths should be stomped on before they
969 * do us any more damage.
971 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
972 bombout((ssh,"Incoming packet was garbled on decryption"));
977 * This enables us to deduce the payload length.
979 st->payload = st->len - st->pad - 1;
981 ssh->pktin.length = st->payload + 5;
984 * So now we can work out the total packet length.
986 st->packetlen = st->len + 4;
987 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
990 * Adjust memory allocation if packet is too big.
992 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
993 ssh->pktin.maxlen = st->packetlen + st->maclen;
994 ssh->pktin.data = srealloc(ssh->pktin.data,
995 ssh->pktin.maxlen + APIEXTRA);
999 * Read and decrypt the remainder of the packet.
1001 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1003 while ((*datalen) == 0)
1004 crReturn(st->packetlen + st->maclen - st->i);
1005 ssh->pktin.data[st->i] = *(*data)++;
1008 /* Decrypt everything _except_ the MAC. */
1010 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1011 ssh->pktin.data + st->cipherblk,
1012 st->packetlen - st->cipherblk);
1018 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1019 st->incoming_sequence)) {
1020 bombout((ssh,"Incorrect MAC received on packet"));
1023 st->incoming_sequence++; /* whether or not we MACed */
1026 * Decompress packet payload.
1029 unsigned char *newpayload;
1032 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1033 ssh->pktin.data + 5, ssh->pktin.length - 5,
1034 &newpayload, &newlen)) {
1035 if (ssh->pktin.maxlen < newlen + 5) {
1036 ssh->pktin.maxlen = newlen + 5;
1037 ssh->pktin.data = srealloc(ssh->pktin.data,
1038 ssh->pktin.maxlen + APIEXTRA);
1040 ssh->pktin.length = 5 + newlen;
1041 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1046 ssh->pktin.savedpos = 6;
1047 ssh->pktin.type = ssh->pktin.data[5];
1050 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1051 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1052 ssh->pktin.data+6, ssh->pktin.length-6);
1054 switch (ssh->pktin.type) {
1056 * These packets we must handle instantly.
1058 case SSH2_MSG_DISCONNECT:
1060 /* log reason code in disconnect message */
1063 int reason = GET_32BIT(ssh->pktin.data + 6);
1064 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1066 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1067 buf = dupprintf("Received disconnect message (%s)",
1068 ssh2_disconnect_reasons[reason]);
1070 buf = dupprintf("Received disconnect message (unknown"
1071 " type %d)", reason);
1075 buf = dupprintf("Disconnection message text: %n%.*s",
1076 &nowlen, msglen, ssh->pktin.data + 14);
1078 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1080 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1081 ssh2_disconnect_reasons[reason] : "unknown",
1087 case SSH2_MSG_IGNORE:
1089 case SSH2_MSG_DEBUG:
1091 /* log the debug message */
1093 /* int display = ssh->pktin.body[6]; */
1094 int stringlen = GET_32BIT(ssh->pktin.data+7);
1096 strcpy(buf, "Remote debug message: ");
1097 prefix = strlen(buf);
1098 if (stringlen > (int)(sizeof(buf)-prefix-1))
1099 stringlen = sizeof(buf)-prefix-1;
1100 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1101 buf[prefix + stringlen] = '\0';
1104 goto next_packet; /* FIXME: print the debug message */
1107 * These packets we need do nothing about here.
1109 case SSH2_MSG_UNIMPLEMENTED:
1110 case SSH2_MSG_SERVICE_REQUEST:
1111 case SSH2_MSG_SERVICE_ACCEPT:
1112 case SSH2_MSG_KEXINIT:
1113 case SSH2_MSG_NEWKEYS:
1114 case SSH2_MSG_KEXDH_INIT:
1115 case SSH2_MSG_KEXDH_REPLY:
1116 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1117 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1118 case SSH2_MSG_KEX_DH_GEX_INIT:
1119 case SSH2_MSG_KEX_DH_GEX_REPLY:
1120 case SSH2_MSG_USERAUTH_REQUEST:
1121 case SSH2_MSG_USERAUTH_FAILURE:
1122 case SSH2_MSG_USERAUTH_SUCCESS:
1123 case SSH2_MSG_USERAUTH_BANNER:
1124 case SSH2_MSG_USERAUTH_PK_OK:
1125 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1126 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1127 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1128 case SSH2_MSG_GLOBAL_REQUEST:
1129 case SSH2_MSG_REQUEST_SUCCESS:
1130 case SSH2_MSG_REQUEST_FAILURE:
1131 case SSH2_MSG_CHANNEL_OPEN:
1132 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1133 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1134 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1135 case SSH2_MSG_CHANNEL_DATA:
1136 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1137 case SSH2_MSG_CHANNEL_EOF:
1138 case SSH2_MSG_CHANNEL_CLOSE:
1139 case SSH2_MSG_CHANNEL_REQUEST:
1140 case SSH2_MSG_CHANNEL_SUCCESS:
1141 case SSH2_MSG_CHANNEL_FAILURE:
1145 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1148 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1149 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1157 static void ssh1_pktout_size(Ssh ssh, int len)
1161 len += 5; /* type and CRC */
1162 pad = 8 - (len % 8);
1165 ssh->pktout.length = len - 5;
1166 if (ssh->pktout.maxlen < biglen) {
1167 ssh->pktout.maxlen = biglen;
1169 /* Allocate enough buffer space for extra block
1170 * for MS CryptEncrypt() */
1171 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1173 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1176 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1179 static void s_wrpkt_start(Ssh ssh, int type, int len)
1181 ssh1_pktout_size(ssh, len);
1182 ssh->pktout.type = type;
1185 static int s_wrpkt_prepare(Ssh ssh)
1187 int pad, len, biglen, i;
1190 ssh->pktout.body[-1] = ssh->pktout.type;
1193 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1194 ssh1_pkt_type(ssh->pktout.type),
1195 ssh->pktout.body, ssh->pktout.length);
1197 if (ssh->v1_compressing) {
1198 unsigned char *compblk;
1200 zlib_compress_block(ssh->cs_comp_ctx,
1201 ssh->pktout.body - 1, ssh->pktout.length + 1,
1202 &compblk, &complen);
1203 ssh1_pktout_size(ssh, complen - 1);
1204 memcpy(ssh->pktout.body - 1, compblk, complen);
1208 len = ssh->pktout.length + 5; /* type and CRC */
1209 pad = 8 - (len % 8);
1212 for (i = 0; i < pad; i++)
1213 ssh->pktout.data[i + 4] = random_byte();
1214 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1215 PUT_32BIT(ssh->pktout.data + biglen, crc);
1216 PUT_32BIT(ssh->pktout.data, len);
1219 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1224 static void s_wrpkt(Ssh ssh)
1227 len = s_wrpkt_prepare(ssh);
1228 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1229 if (backlog > SSH_MAX_BACKLOG)
1230 ssh_throttle_all(ssh, 1, backlog);
1233 static void s_wrpkt_defer(Ssh ssh)
1236 len = s_wrpkt_prepare(ssh);
1237 if (ssh->deferred_len + len > ssh->deferred_size) {
1238 ssh->deferred_size = ssh->deferred_len + len + 128;
1239 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1240 ssh->deferred_size);
1242 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1243 ssh->deferred_len += len;
1247 * Construct a packet with the specified contents.
1249 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1251 unsigned char *p, *argp, argchar;
1252 unsigned long argint;
1253 int pktlen, argtype, arglen;
1257 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1260 (void) va_arg(ap1, int);
1264 (void) va_arg(ap1, int);
1268 (void) va_arg(ap1, unsigned char *);
1269 arglen = va_arg(ap1, int);
1273 argp = va_arg(ap1, unsigned char *);
1274 arglen = strlen(argp);
1275 pktlen += 4 + arglen;
1278 bn = va_arg(ap1, Bignum);
1279 pktlen += ssh1_bignum_length(bn);
1286 s_wrpkt_start(ssh, pkttype, pktlen);
1287 p = ssh->pktout.body;
1289 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1292 argint = va_arg(ap2, int);
1293 PUT_32BIT(p, argint);
1297 argchar = (unsigned char) va_arg(ap2, int);
1302 argp = va_arg(ap2, unsigned char *);
1303 arglen = va_arg(ap2, int);
1304 memcpy(p, argp, arglen);
1308 argp = va_arg(ap2, unsigned char *);
1309 arglen = strlen(argp);
1310 PUT_32BIT(p, arglen);
1311 memcpy(p + 4, argp, arglen);
1315 bn = va_arg(ap2, Bignum);
1316 p += ssh1_write_bignum(p, bn);
1322 static void send_packet(Ssh ssh, int pkttype, ...)
1325 va_start(ap1, pkttype);
1326 va_start(ap2, pkttype);
1327 construct_packet(ssh, pkttype, ap1, ap2);
1331 static void defer_packet(Ssh ssh, int pkttype, ...)
1334 va_start(ap1, pkttype);
1335 va_start(ap2, pkttype);
1336 construct_packet(ssh, pkttype, ap1, ap2);
1340 static int ssh_versioncmp(char *a, char *b)
1343 unsigned long av, bv;
1345 av = strtoul(a, &ae, 10);
1346 bv = strtoul(b, &be, 10);
1348 return (av < bv ? -1 : +1);
1353 av = strtoul(ae, &ae, 10);
1354 bv = strtoul(be, &be, 10);
1356 return (av < bv ? -1 : +1);
1361 * Utility routines for putting an SSH-protocol `string' and
1362 * `uint32' into a SHA state.
1365 static void sha_string(SHA_State * s, void *str, int len)
1367 unsigned char lenblk[4];
1368 PUT_32BIT(lenblk, len);
1369 SHA_Bytes(s, lenblk, 4);
1370 SHA_Bytes(s, str, len);
1373 static void sha_uint32(SHA_State * s, unsigned i)
1375 unsigned char intblk[4];
1376 PUT_32BIT(intblk, i);
1377 SHA_Bytes(s, intblk, 4);
1381 * SSH2 packet construction functions.
1383 static void ssh2_pkt_ensure(Ssh ssh, int length)
1385 if (ssh->pktout.maxlen < length) {
1386 ssh->pktout.maxlen = length + 256;
1387 ssh->pktout.data = srealloc(ssh->pktout.data,
1388 ssh->pktout.maxlen + APIEXTRA);
1389 if (!ssh->pktout.data)
1390 fatalbox("Out of memory");
1393 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1395 ssh->pktout.length += len;
1396 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1397 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1399 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1401 ssh2_pkt_adddata(ssh, &byte, 1);
1403 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1405 ssh->pktout.length = 5;
1406 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1408 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1410 ssh2_pkt_adddata(ssh, &value, 1);
1412 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1415 PUT_32BIT(x, value);
1416 ssh2_pkt_adddata(ssh, x, 4);
1418 static void ssh2_pkt_addstring_start(Ssh ssh)
1420 ssh2_pkt_adduint32(ssh, 0);
1421 ssh->pktout.savedpos = ssh->pktout.length;
1423 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1425 ssh2_pkt_adddata(ssh, data, strlen(data));
1426 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1427 ssh->pktout.length - ssh->pktout.savedpos);
1429 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1431 ssh2_pkt_adddata(ssh, data, len);
1432 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1433 ssh->pktout.length - ssh->pktout.savedpos);
1435 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1437 ssh2_pkt_addstring_start(ssh);
1438 ssh2_pkt_addstring_str(ssh, data);
1440 static char *ssh2_mpint_fmt(Bignum b, int *len)
1443 int i, n = (bignum_bitcount(b) + 7) / 8;
1446 fatalbox("out of memory");
1448 for (i = 1; i <= n; i++)
1449 p[i] = bignum_byte(b, n - i);
1451 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1453 memmove(p, p + i, n + 1 - i);
1457 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1461 p = ssh2_mpint_fmt(b, &len);
1462 ssh2_pkt_addstring_start(ssh);
1463 ssh2_pkt_addstring_data(ssh, p, len);
1468 * Construct an SSH2 final-form packet: compress it, encrypt it,
1469 * put the MAC on it. Final packet, ready to be sent, is stored in
1470 * ssh->pktout.data. Total length is returned.
1472 static int ssh2_pkt_construct(Ssh ssh)
1474 int cipherblk, maclen, padding, i;
1477 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1478 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1479 ssh->pktout.data + 6, ssh->pktout.length - 6);
1482 * Compress packet payload.
1485 unsigned char *newpayload;
1488 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1489 ssh->pktout.length - 5,
1490 &newpayload, &newlen)) {
1491 ssh->pktout.length = 5;
1492 ssh2_pkt_adddata(ssh, newpayload, newlen);
1498 * Add padding. At least four bytes, and must also bring total
1499 * length (minus MAC) up to a multiple of the block size.
1501 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1502 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1505 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1506 maclen = ssh->csmac ? ssh->csmac->len : 0;
1507 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1508 ssh->pktout.data[4] = padding;
1509 for (i = 0; i < padding; i++)
1510 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1511 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1513 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1514 ssh->pktout.length + padding,
1515 ssh->v2_outgoing_sequence);
1516 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1519 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1520 ssh->pktout.data, ssh->pktout.length + padding);
1522 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1523 return ssh->pktout.length + padding + maclen;
1527 * Construct and send an SSH2 packet immediately.
1529 static void ssh2_pkt_send(Ssh ssh)
1533 len = ssh2_pkt_construct(ssh);
1534 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1535 if (backlog > SSH_MAX_BACKLOG)
1536 ssh_throttle_all(ssh, 1, backlog);
1540 * Construct an SSH2 packet and add it to a deferred data block.
1541 * Useful for sending multiple packets in a single sk_write() call,
1542 * to prevent a traffic-analysing listener from being able to work
1543 * out the length of any particular packet (such as the password
1546 * Note that because SSH2 sequence-numbers its packets, this can
1547 * NOT be used as an m4-style `defer' allowing packets to be
1548 * constructed in one order and sent in another.
1550 static void ssh2_pkt_defer(Ssh ssh)
1552 int len = ssh2_pkt_construct(ssh);
1553 if (ssh->deferred_len + len > ssh->deferred_size) {
1554 ssh->deferred_size = ssh->deferred_len + len + 128;
1555 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1556 ssh->deferred_size);
1558 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1559 ssh->deferred_len += len;
1563 * Send the whole deferred data block constructed by
1564 * ssh2_pkt_defer() or SSH1's defer_packet().
1566 static void ssh_pkt_defersend(Ssh ssh)
1569 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1570 ssh->deferred_len = ssh->deferred_size = 0;
1571 sfree(ssh->deferred_send_data);
1572 ssh->deferred_send_data = NULL;
1573 if (backlog > SSH_MAX_BACKLOG)
1574 ssh_throttle_all(ssh, 1, backlog);
1578 void bndebug(char *string, Bignum b)
1582 p = ssh2_mpint_fmt(b, &len);
1583 debug(("%s", string));
1584 for (i = 0; i < len; i++)
1585 debug((" %02x", p[i]));
1591 static void sha_mpint(SHA_State * s, Bignum b)
1595 p = ssh2_mpint_fmt(b, &len);
1596 sha_string(s, p, len);
1601 * SSH2 packet decode functions.
1603 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1605 unsigned long value;
1606 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1607 return 0; /* arrgh, no way to decline (FIXME?) */
1608 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1609 ssh->pktin.savedpos += 4;
1612 static int ssh2_pkt_getbool(Ssh ssh)
1614 unsigned long value;
1615 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1616 return 0; /* arrgh, no way to decline (FIXME?) */
1617 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1618 ssh->pktin.savedpos++;
1621 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1626 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1628 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1632 ssh->pktin.savedpos += 4;
1633 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1635 *p = ssh->pktin.data + ssh->pktin.savedpos;
1636 ssh->pktin.savedpos += *length;
1638 static Bignum ssh2_pkt_getmp(Ssh ssh)
1644 ssh2_pkt_getstring(ssh, &p, &length);
1648 bombout((ssh,"internal error: Can't handle negative mpints"));
1651 b = bignum_from_bytes(p, length);
1656 * Helper function to add an SSH2 signature blob to a packet.
1657 * Expects to be shown the public key blob as well as the signature
1658 * blob. Normally works just like ssh2_pkt_addstring, but will
1659 * fiddle with the signature packet if necessary for
1660 * BUG_SSH2_RSA_PADDING.
1662 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1663 void *sigblob_v, int sigblob_len)
1665 unsigned char *pkblob = (unsigned char *)pkblob_v;
1666 unsigned char *sigblob = (unsigned char *)sigblob_v;
1668 /* dmemdump(pkblob, pkblob_len); */
1669 /* dmemdump(sigblob, sigblob_len); */
1672 * See if this is in fact an ssh-rsa signature and a buggy
1673 * server; otherwise we can just do this the easy way.
1675 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1676 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1677 int pos, len, siglen;
1680 * Find the byte length of the modulus.
1683 pos = 4+7; /* skip over "ssh-rsa" */
1684 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1685 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1686 pos += 4; /* find modulus itself */
1687 while (len > 0 && pkblob[pos] == 0)
1689 /* debug(("modulus length is %d\n", len)); */
1692 * Now find the signature integer.
1694 pos = 4+7; /* skip over "ssh-rsa" */
1695 siglen = GET_32BIT(sigblob+pos);
1696 /* debug(("signature length is %d\n", siglen)); */
1698 if (len != siglen) {
1699 unsigned char newlen[4];
1700 ssh2_pkt_addstring_start(ssh);
1701 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1702 /* dmemdump(sigblob, pos); */
1703 pos += 4; /* point to start of actual sig */
1704 PUT_32BIT(newlen, len);
1705 ssh2_pkt_addstring_data(ssh, newlen, 4);
1706 /* dmemdump(newlen, 4); */
1708 while (len-- > siglen) {
1709 ssh2_pkt_addstring_data(ssh, newlen, 1);
1710 /* dmemdump(newlen, 1); */
1712 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1713 /* dmemdump(sigblob+pos, siglen); */
1717 /* Otherwise fall through and do it the easy way. */
1720 ssh2_pkt_addstring_start(ssh);
1721 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1725 * Examine the remote side's version string and compare it against
1726 * a list of known buggy implementations.
1728 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1730 char *imp; /* pointer to implementation part */
1732 imp += strcspn(imp, "-");
1734 imp += strcspn(imp, "-");
1737 ssh->remote_bugs = 0;
1739 if (cfg.sshbug_ignore1 == BUG_ON ||
1740 (cfg.sshbug_ignore1 == BUG_AUTO &&
1741 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1742 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1743 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1745 * These versions don't support SSH1_MSG_IGNORE, so we have
1746 * to use a different defence against password length
1749 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1750 logevent("We believe remote version has SSH1 ignore bug");
1753 if (cfg.sshbug_plainpw1 == BUG_ON ||
1754 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1755 (!strcmp(imp, "Cisco-1.25")))) {
1757 * These versions need a plain password sent; they can't
1758 * handle having a null and a random length of data after
1761 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1762 logevent("We believe remote version needs a plain SSH1 password");
1765 if (cfg.sshbug_rsa1 == BUG_ON ||
1766 (cfg.sshbug_rsa1 == BUG_AUTO &&
1767 (!strcmp(imp, "Cisco-1.25")))) {
1769 * These versions apparently have no clue whatever about
1770 * RSA authentication and will panic and die if they see
1771 * an AUTH_RSA message.
1773 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1774 logevent("We believe remote version can't handle RSA authentication");
1777 if (cfg.sshbug_hmac2 == BUG_ON ||
1778 (cfg.sshbug_hmac2 == BUG_AUTO &&
1779 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1780 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1781 wc_match("2.1 *", imp)))) {
1783 * These versions have the HMAC bug.
1785 ssh->remote_bugs |= BUG_SSH2_HMAC;
1786 logevent("We believe remote version has SSH2 HMAC bug");
1789 if (cfg.sshbug_derivekey2 == BUG_ON ||
1790 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1791 (wc_match("2.0.*", imp)))) {
1793 * These versions have the key-derivation bug (failing to
1794 * include the literal shared secret in the hashes that
1795 * generate the keys).
1797 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1798 logevent("We believe remote version has SSH2 key-derivation bug");
1801 if (cfg.sshbug_rsapad2 == BUG_ON ||
1802 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1803 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1804 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1806 * These versions have the SSH2 RSA padding bug.
1808 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1809 logevent("We believe remote version has SSH2 RSA padding bug");
1812 if (cfg.sshbug_dhgex2 == BUG_ON) {
1814 * User specified the SSH2 DH GEX bug.
1816 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1817 logevent("We believe remote version has SSH2 DH group exchange bug");
1821 static int do_ssh_init(Ssh ssh, unsigned char c)
1823 struct do_ssh_init_state {
1831 crState(do_ssh_init_state);
1833 crBegin(ssh->do_ssh_init_crstate);
1835 /* Search for the string "SSH-" in the input. */
1838 static const int transS[] = { 1, 2, 2, 1 };
1839 static const int transH[] = { 0, 0, 3, 0 };
1840 static const int transminus[] = { 0, 0, 0, -1 };
1842 s->i = transS[s->i];
1844 s->i = transH[s->i];
1846 s->i = transminus[s->i];
1851 crReturn(1); /* get another character */
1855 s->vstring = smalloc(s->vstrsize);
1856 strcpy(s->vstring, "SSH-");
1860 crReturn(1); /* get another char */
1861 if (s->vslen >= s->vstrsize - 1) {
1863 s->vstring = srealloc(s->vstring, s->vstrsize);
1865 s->vstring[s->vslen++] = c;
1868 s->version[s->i] = '\0';
1870 } else if (s->i < sizeof(s->version) - 1)
1871 s->version[s->i++] = c;
1872 } else if (c == '\n')
1876 ssh->agentfwd_enabled = FALSE;
1877 ssh->rdpkt2_state.incoming_sequence = 0;
1879 s->vstring[s->vslen] = 0;
1880 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1883 vlog = smalloc(20 + s->vslen);
1884 sprintf(vlog, "Server version: %s", s->vstring);
1888 ssh_detect_bugs(ssh, s->vstring);
1891 * Decide which SSH protocol version to support.
1894 /* Anything strictly below "2.0" means protocol 1 is supported. */
1895 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1896 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1897 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1899 if (cfg.sshprot == 0 && !s->proto1) {
1900 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
1903 if (cfg.sshprot == 3 && !s->proto2) {
1904 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
1908 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1912 char verstring[80], vlog[100];
1913 sprintf(verstring, "SSH-2.0-%s", sshver);
1914 SHA_Init(&ssh->exhashbase);
1916 * Hash our version string and their version string.
1918 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1919 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1920 sprintf(vlog, "We claim version: %s", verstring);
1922 strcat(verstring, "\n");
1923 logevent("Using SSH protocol version 2");
1924 sk_write(ssh->s, verstring, strlen(verstring));
1925 ssh->protocol = ssh2_protocol;
1927 ssh->s_rdpkt = ssh2_rdpkt;
1932 char verstring[80], vlog[100];
1933 sprintf(verstring, "SSH-%s-%s",
1934 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1936 sprintf(vlog, "We claim version: %s", verstring);
1938 strcat(verstring, "\n");
1940 logevent("Using SSH protocol version 1");
1941 sk_write(ssh->s, verstring, strlen(verstring));
1942 ssh->protocol = ssh1_protocol;
1944 ssh->s_rdpkt = ssh1_rdpkt;
1946 ssh->state = SSH_STATE_BEFORE_SIZE;
1953 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1955 crBegin(ssh->ssh_gotdata_crstate);
1958 * To begin with, feed the characters one by one to the
1959 * protocol initialisation / selection function do_ssh_init().
1960 * When that returns 0, we're done with the initial greeting
1961 * exchange and can move on to packet discipline.
1964 int ret; /* need not be kept across crReturn */
1966 crReturnV; /* more data please */
1967 ret = do_ssh_init(ssh, *data);
1975 * We emerge from that loop when the initial negotiation is
1976 * over and we have selected an s_rdpkt function. Now pass
1977 * everything to s_rdpkt, and then pass the resulting packets
1978 * to the proper protocol handler.
1983 while (datalen > 0) {
1984 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1985 if (ssh->state == SSH_STATE_CLOSED) {
1988 ssh->protocol(ssh, NULL, 0, 1);
1989 if (ssh->state == SSH_STATE_CLOSED) {
1999 static int ssh_closing(Plug plug, char *error_msg, int error_code,
2002 Ssh ssh = (Ssh) plug;
2003 ssh->state = SSH_STATE_CLOSED;
2009 /* A socket error has occurred. */
2010 logevent(error_msg);
2011 connection_fatal(ssh->frontend, error_msg);
2013 /* Otherwise, the remote side closed the connection normally. */
2018 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2020 Ssh ssh = (Ssh) plug;
2021 ssh_gotdata(ssh, data, len);
2022 if (ssh->state == SSH_STATE_CLOSED) {
2032 static void ssh_sent(Plug plug, int bufsize)
2034 Ssh ssh = (Ssh) plug;
2036 * If the send backlog on the SSH socket itself clears, we
2037 * should unthrottle the whole world if it was throttled.
2039 if (bufsize < SSH_MAX_BACKLOG)
2040 ssh_throttle_all(ssh, 0, bufsize);
2044 * Connect to specified host and port.
2045 * Returns an error message, or NULL on success.
2046 * Also places the canonical host name into `realhost'. It must be
2047 * freed by the caller.
2049 static char *connect_to_host(Ssh ssh, char *host, int port,
2050 char **realhost, int nodelay)
2052 static const struct plug_function_table fn_table = {
2062 ssh->savedhost = smalloc(1 + strlen(host));
2063 if (!ssh->savedhost)
2064 fatalbox("Out of memory");
2065 strcpy(ssh->savedhost, host);
2068 port = 22; /* default ssh port */
2069 ssh->savedport = port;
2074 logeventf(ssh, "Looking up host \"%s\"", host);
2075 addr = sk_namelookup(host, realhost);
2076 if ((err = sk_addr_error(addr)))
2084 sk_getaddr(addr, addrbuf, 100);
2085 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2087 ssh->fn = &fn_table;
2088 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2089 if ((err = sk_socket_error(ssh->s))) {
2098 * Throttle or unthrottle the SSH connection.
2100 static void ssh1_throttle(Ssh ssh, int adjust)
2102 int old_count = ssh->v1_throttle_count;
2103 ssh->v1_throttle_count += adjust;
2104 assert(ssh->v1_throttle_count >= 0);
2105 if (ssh->v1_throttle_count && !old_count) {
2106 sk_set_frozen(ssh->s, 1);
2107 } else if (!ssh->v1_throttle_count && old_count) {
2108 sk_set_frozen(ssh->s, 0);
2113 * Throttle or unthrottle _all_ local data streams (for when sends
2114 * on the SSH connection itself back up).
2116 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2119 struct ssh_channel *c;
2121 if (enable == ssh->throttled_all)
2123 ssh->throttled_all = enable;
2124 ssh->overall_bufsize = bufsize;
2127 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2129 case CHAN_MAINSESSION:
2131 * This is treated separately, outside the switch.
2135 x11_override_throttle(c->u.x11.s, enable);
2138 /* Agent channels require no buffer management. */
2141 pfd_override_throttle(c->u.x11.s, enable);
2148 * Username and password input, abstracted off into routines
2149 * reusable in several places - even between SSH1 and SSH2.
2152 /* Set up a username or password input loop on a given buffer. */
2153 void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2155 ssh->userpass_input_buffer = buffer;
2156 ssh->userpass_input_buflen = buflen;
2157 ssh->userpass_input_bufpos = 0;
2158 ssh->userpass_input_echo = echo;
2162 * Process some terminal data in the course of username/password
2163 * input. Returns >0 for success (line of input returned in
2164 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2165 * for inconclusive (keep waiting for more input please).
2167 int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2172 switch (c = *in++) {
2175 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2176 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2181 if (ssh->userpass_input_bufpos > 0) {
2182 if (ssh->userpass_input_echo)
2183 c_write_str(ssh, "\b \b");
2184 ssh->userpass_input_bufpos--;
2189 while (ssh->userpass_input_bufpos > 0) {
2190 if (ssh->userpass_input_echo)
2191 c_write_str(ssh, "\b \b");
2192 ssh->userpass_input_bufpos--;
2200 if (((c >= ' ' && c <= '~') ||
2201 ((unsigned char) c >= 160))
2202 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2203 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2204 if (ssh->userpass_input_echo)
2205 c_write(ssh, &c, 1);
2214 * Handle the key exchange and user authentication phases.
2216 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2219 unsigned char cookie[8];
2220 struct RSAKey servkey, hostkey;
2221 struct MD5Context md5c;
2222 struct do_ssh1_login_state {
2224 unsigned char *rsabuf, *keystr1, *keystr2;
2225 unsigned long supported_ciphers_mask, supported_auths_mask;
2226 int tried_publickey, tried_agent;
2227 int tis_auth_refused, ccard_auth_refused;
2228 unsigned char session_id[16];
2231 void *publickey_blob;
2232 int publickey_bloblen;
2238 unsigned char request[5], *response, *p;
2247 crState(do_ssh1_login_state);
2249 crBegin(ssh->do_ssh1_login_crstate);
2254 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2255 bombout((ssh,"Public key packet not received"));
2259 logevent("Received public keys");
2261 memcpy(cookie, ssh->pktin.body, 8);
2263 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2264 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2267 * Log the host key fingerprint.
2271 logevent("Host key fingerprint is:");
2272 strcpy(logmsg, " ");
2273 hostkey.comment = NULL;
2274 rsa_fingerprint(logmsg + strlen(logmsg),
2275 sizeof(logmsg) - strlen(logmsg), &hostkey);
2279 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2280 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2281 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2283 ssh->v1_local_protoflags =
2284 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2285 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2288 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2289 MD5Update(&md5c, s->keystr1, servkey.bytes);
2290 MD5Update(&md5c, ssh->pktin.body, 8);
2291 MD5Final(s->session_id, &md5c);
2293 for (i = 0; i < 32; i++)
2294 ssh->session_key[i] = random_byte();
2296 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2298 s->rsabuf = smalloc(s->len);
2300 fatalbox("Out of memory");
2303 * Verify the host key.
2307 * First format the key into a string.
2309 int len = rsastr_len(&hostkey);
2310 char fingerprint[100];
2311 char *keystr = smalloc(len);
2313 fatalbox("Out of memory");
2314 rsastr_fmt(keystr, &hostkey);
2315 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2316 verify_ssh_host_key(ssh->frontend,
2317 ssh->savedhost, ssh->savedport, "rsa", keystr,
2322 for (i = 0; i < 32; i++) {
2323 s->rsabuf[i] = ssh->session_key[i];
2325 s->rsabuf[i] ^= s->session_id[i];
2328 if (hostkey.bytes > servkey.bytes) {
2329 rsaencrypt(s->rsabuf, 32, &servkey);
2330 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2332 rsaencrypt(s->rsabuf, 32, &hostkey);
2333 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2336 logevent("Encrypted session key");
2339 int cipher_chosen = 0, warn = 0;
2340 char *cipher_string = NULL;
2342 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2343 int next_cipher = cfg.ssh_cipherlist[i];
2344 if (next_cipher == CIPHER_WARN) {
2345 /* If/when we choose a cipher, warn about it */
2347 } else if (next_cipher == CIPHER_AES) {
2348 /* XXX Probably don't need to mention this. */
2349 logevent("AES not supported in SSH1, skipping");
2351 switch (next_cipher) {
2352 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2353 cipher_string = "3DES"; break;
2354 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2355 cipher_string = "Blowfish"; break;
2356 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2357 cipher_string = "single-DES"; break;
2359 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2363 if (!cipher_chosen) {
2364 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2365 bombout((ssh,"Server violates SSH 1 protocol by not "
2366 "supporting 3DES encryption"));
2368 /* shouldn't happen */
2369 bombout((ssh,"No supported ciphers found"));
2373 /* Warn about chosen cipher if necessary. */
2375 askcipher(ssh->frontend, cipher_string, 0);
2378 switch (s->cipher_type) {
2379 case SSH_CIPHER_3DES:
2380 logevent("Using 3DES encryption");
2382 case SSH_CIPHER_DES:
2383 logevent("Using single-DES encryption");
2385 case SSH_CIPHER_BLOWFISH:
2386 logevent("Using Blowfish encryption");
2390 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2391 PKT_CHAR, s->cipher_type,
2392 PKT_DATA, cookie, 8,
2393 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2394 PKT_DATA, s->rsabuf, s->len,
2395 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2397 logevent("Trying to enable encryption...");
2401 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2402 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2404 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2405 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2406 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2408 ssh->crcda_ctx = crcda_make_context();
2409 logevent("Installing CRC compensation attack detector");
2413 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2414 bombout((ssh,"Encryption not successfully enabled"));
2418 logevent("Successfully started encryption");
2422 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2423 if (ssh_get_line && !ssh_getline_pw_only) {
2424 if (!ssh_get_line("login as: ",
2425 s->username, sizeof(s->username), FALSE)) {
2427 * get_line failed to get a username.
2430 logevent("No username provided. Abandoning session.");
2431 ssh->state = SSH_STATE_CLOSED;
2435 int ret; /* need not be kept over crReturn */
2436 c_write_str(ssh, "login as: ");
2439 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2441 crWaitUntil(!ispkt);
2442 ret = process_userpass_input(ssh, in, inlen);
2446 c_write_str(ssh, "\r\n");
2449 strncpy(s->username, cfg.username, sizeof(s->username));
2450 s->username[sizeof(s->username)-1] = '\0';
2453 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2455 char userlog[22 + sizeof(s->username)];
2456 sprintf(userlog, "Sent username \"%s\"", s->username);
2458 if (flags & FLAG_INTERACTIVE &&
2459 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2460 strcat(userlog, "\r\n");
2461 c_write_str(ssh, userlog);
2468 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2469 /* We must not attempt PK auth. Pretend we've already tried it. */
2470 s->tried_publickey = s->tried_agent = 1;
2472 s->tried_publickey = s->tried_agent = 0;
2474 s->tis_auth_refused = s->ccard_auth_refused = 0;
2475 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2477 if (!rsakey_pubblob(cfg.keyfile,
2478 &s->publickey_blob, &s->publickey_bloblen))
2479 s->publickey_blob = NULL;
2481 s->publickey_blob = NULL;
2483 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2484 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2486 if (agent_exists() && !s->tried_agent) {
2488 * Attempt RSA authentication using Pageant.
2494 logevent("Pageant is running. Requesting keys.");
2496 /* Request the keys held by the agent. */
2497 PUT_32BIT(s->request, 1);
2498 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2499 agent_query(s->request, 5, &r, &s->responselen);
2500 s->response = (unsigned char *) r;
2501 if (s->response && s->responselen >= 5 &&
2502 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2503 s->p = s->response + 5;
2504 s->nkeys = GET_32BIT(s->p);
2508 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2511 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2514 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2517 if (s->publickey_blob &&
2518 !memcmp(s->p, s->publickey_blob,
2519 s->publickey_bloblen)) {
2520 logevent("This key matches configured key file");
2521 s->tried_publickey = 1;
2524 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2525 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2526 s->commentlen = GET_32BIT(s->p);
2529 s->p += s->commentlen;
2530 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2531 PKT_BIGNUM, s->key.modulus, PKT_END);
2533 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2534 logevent("Key refused");
2537 logevent("Received RSA challenge");
2538 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2540 char *agentreq, *q, *ret;
2543 len = 1 + 4; /* message type, bit count */
2544 len += ssh1_bignum_length(s->key.exponent);
2545 len += ssh1_bignum_length(s->key.modulus);
2546 len += ssh1_bignum_length(s->challenge);
2547 len += 16; /* session id */
2548 len += 4; /* response format */
2549 agentreq = smalloc(4 + len);
2550 PUT_32BIT(agentreq, len);
2552 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2553 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2555 q += ssh1_write_bignum(q, s->key.exponent);
2556 q += ssh1_write_bignum(q, s->key.modulus);
2557 q += ssh1_write_bignum(q, s->challenge);
2558 memcpy(q, s->session_id, 16);
2560 PUT_32BIT(q, 1); /* response format */
2561 agent_query(agentreq, len + 4, &vret, &retlen);
2565 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2566 logevent("Sending Pageant's response");
2567 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2568 PKT_DATA, ret + 5, 16,
2572 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2574 ("Pageant's response accepted");
2575 if (flags & FLAG_VERBOSE) {
2576 c_write_str(ssh, "Authenticated using"
2578 c_write(ssh, s->commentp,
2580 c_write_str(ssh, "\" from agent\r\n");
2585 ("Pageant's response not accepted");
2588 ("Pageant failed to answer challenge");
2592 logevent("No reply received from Pageant");
2595 freebn(s->key.exponent);
2596 freebn(s->key.modulus);
2597 freebn(s->challenge);
2605 if (*cfg.keyfile && !s->tried_publickey)
2606 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2608 if (cfg.try_tis_auth &&
2609 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2610 !s->tis_auth_refused) {
2611 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2612 logevent("Requested TIS authentication");
2613 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2615 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2616 logevent("TIS authentication declined");
2617 if (flags & FLAG_INTERACTIVE)
2618 c_write_str(ssh, "TIS authentication refused.\r\n");
2619 s->tis_auth_refused = 1;
2622 int challengelen = GET_32BIT(ssh->pktin.body);
2623 logevent("Received TIS challenge");
2624 if (challengelen > sizeof(s->prompt) - 1)
2625 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2626 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2627 /* Prompt heuristic comes from OpenSSH */
2628 strncpy(s->prompt + challengelen,
2629 memchr(s->prompt, '\n', challengelen) ?
2630 "": "\r\nResponse: ",
2631 (sizeof s->prompt) - challengelen);
2632 s->prompt[(sizeof s->prompt) - 1] = '\0';
2635 if (cfg.try_tis_auth &&
2636 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2637 !s->ccard_auth_refused) {
2638 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2639 logevent("Requested CryptoCard authentication");
2640 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2642 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2643 logevent("CryptoCard authentication declined");
2644 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2645 s->ccard_auth_refused = 1;
2648 int challengelen = GET_32BIT(ssh->pktin.body);
2649 logevent("Received CryptoCard challenge");
2650 if (challengelen > sizeof(s->prompt) - 1)
2651 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2652 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2653 strncpy(s->prompt + challengelen,
2654 memchr(s->prompt, '\n', challengelen) ?
2655 "" : "\r\nResponse: ",
2656 sizeof(s->prompt) - challengelen);
2657 s->prompt[sizeof(s->prompt) - 1] = '\0';
2660 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2661 sprintf(s->prompt, "%.90s@%.90s's password: ",
2662 s->username, ssh->savedhost);
2664 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2665 char *comment = NULL;
2668 if (flags & FLAG_VERBOSE)
2669 c_write_str(ssh, "Trying public key authentication.\r\n");
2670 logeventf(ssh, "Trying public key \"%s\"", cfg.keyfile);
2671 type = key_type(cfg.keyfile);
2672 if (type != SSH_KEYTYPE_SSH1) {
2673 sprintf(msgbuf, "Key is of wrong type (%s)",
2674 key_type_to_str(type));
2676 c_write_str(ssh, msgbuf);
2677 c_write_str(ssh, "\r\n");
2678 s->tried_publickey = 1;
2681 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2682 if (flags & FLAG_VERBOSE)
2683 c_write_str(ssh, "No passphrase required.\r\n");
2686 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2691 * Show password prompt, having first obtained it via a TIS
2692 * or CryptoCard exchange if we're doing TIS or CryptoCard
2696 if (!ssh_get_line(s->prompt, s->password,
2697 sizeof(s->password), TRUE)) {
2699 * get_line failed to get a password (for example
2700 * because one was supplied on the command line
2701 * which has already failed to work). Terminate.
2703 send_packet(ssh, SSH1_MSG_DISCONNECT,
2704 PKT_STR, "No more passwords available to try",
2706 logevent("Unable to authenticate");
2707 connection_fatal(ssh->frontend, "Unable to authenticate");
2708 ssh->state = SSH_STATE_CLOSED;
2712 /* Prompt may have come from server. We've munged it a bit, so
2713 * we know it to be zero-terminated at least once. */
2714 int ret; /* need not be saved over crReturn */
2715 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2718 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2720 crWaitUntil(!ispkt);
2721 ret = process_userpass_input(ssh, in, inlen);
2725 c_write_str(ssh, "\r\n");
2729 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2731 * Try public key authentication with the specified
2734 s->tried_publickey = 1;
2737 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2739 c_write_str(ssh, "Couldn't load private key from ");
2740 c_write_str(ssh, cfg.keyfile);
2741 c_write_str(ssh, ".\r\n");
2742 continue; /* go and try password */
2745 c_write_str(ssh, "Wrong passphrase.\r\n");
2746 s->tried_publickey = 0;
2747 continue; /* try again */
2752 * Send a public key attempt.
2754 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2755 PKT_BIGNUM, s->key.modulus, PKT_END);
2758 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2759 c_write_str(ssh, "Server refused our public key.\r\n");
2760 continue; /* go and try password */
2762 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2763 bombout((ssh,"Bizarre response to offer of public key"));
2769 unsigned char buffer[32];
2770 Bignum challenge, response;
2772 ssh1_read_bignum(ssh->pktin.body, &challenge);
2773 response = rsadecrypt(challenge, &s->key);
2774 freebn(s->key.private_exponent);/* burn the evidence */
2776 for (i = 0; i < 32; i++) {
2777 buffer[i] = bignum_byte(response, 31 - i);
2781 MD5Update(&md5c, buffer, 32);
2782 MD5Update(&md5c, s->session_id, 16);
2783 MD5Final(buffer, &md5c);
2785 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2786 PKT_DATA, buffer, 16, PKT_END);
2793 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2794 if (flags & FLAG_VERBOSE)
2795 c_write_str(ssh, "Failed to authenticate with"
2796 " our public key.\r\n");
2797 continue; /* go and try password */
2798 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2799 bombout((ssh,"Bizarre response to RSA authentication response"));
2803 break; /* we're through! */
2805 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2807 * Defence against traffic analysis: we send a
2808 * whole bunch of packets containing strings of
2809 * different lengths. One of these strings is the
2810 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2811 * The others are all random data in
2812 * SSH1_MSG_IGNORE packets. This way a passive
2813 * listener can't tell which is the password, and
2814 * hence can't deduce the password length.
2816 * Anybody with a password length greater than 16
2817 * bytes is going to have enough entropy in their
2818 * password that a listener won't find it _that_
2819 * much help to know how long it is. So what we'll
2822 * - if password length < 16, we send 15 packets
2823 * containing string lengths 1 through 15
2825 * - otherwise, we let N be the nearest multiple
2826 * of 8 below the password length, and send 8
2827 * packets containing string lengths N through
2828 * N+7. This won't obscure the order of
2829 * magnitude of the password length, but it will
2830 * introduce a bit of extra uncertainty.
2832 * A few servers (the old 1.2.18 through 1.2.22)
2833 * can't deal with SSH1_MSG_IGNORE. For these
2834 * servers, we need an alternative defence. We make
2835 * use of the fact that the password is interpreted
2836 * as a C string: so we can append a NUL, then some
2839 * One server (a Cisco one) can deal with neither
2840 * SSH1_MSG_IGNORE _nor_ a padded password string.
2841 * For this server we are left with no defences
2842 * against password length sniffing.
2844 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2846 * The server can deal with SSH1_MSG_IGNORE, so
2847 * we can use the primary defence.
2849 int bottom, top, pwlen, i;
2852 pwlen = strlen(s->password);
2854 bottom = 0; /* zero length passwords are OK! :-) */
2857 bottom = pwlen & ~7;
2861 assert(pwlen >= bottom && pwlen <= top);
2863 randomstr = smalloc(top + 1);
2865 for (i = bottom; i <= top; i++) {
2867 defer_packet(ssh, s->pwpkt_type,
2868 PKT_STR, s->password, PKT_END);
2870 for (j = 0; j < i; j++) {
2872 randomstr[j] = random_byte();
2873 } while (randomstr[j] == '\0');
2875 randomstr[i] = '\0';
2876 defer_packet(ssh, SSH1_MSG_IGNORE,
2877 PKT_STR, randomstr, PKT_END);
2880 logevent("Sending password with camouflage packets");
2881 ssh_pkt_defersend(ssh);
2883 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2885 * The server can't deal with SSH1_MSG_IGNORE
2886 * but can deal with padded passwords, so we
2887 * can use the secondary defence.
2893 len = strlen(s->password);
2894 if (len < sizeof(string)) {
2896 strcpy(string, s->password);
2897 len++; /* cover the zero byte */
2898 while (len < sizeof(string)) {
2899 string[len++] = (char) random_byte();
2904 logevent("Sending length-padded password");
2905 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2906 PKT_DATA, ss, len, PKT_END);
2909 * The server has _both_
2910 * BUG_CHOKES_ON_SSH1_IGNORE and
2911 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2912 * therefore nothing we can do.
2915 len = strlen(s->password);
2916 logevent("Sending unpadded password");
2917 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2918 PKT_DATA, s->password, len, PKT_END);
2921 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2924 logevent("Sent password");
2925 memset(s->password, 0, strlen(s->password));
2927 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2928 if (flags & FLAG_VERBOSE)
2929 c_write_str(ssh, "Access denied\r\n");
2930 logevent("Authentication refused");
2931 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2932 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
2937 logevent("Authentication successful");
2942 void sshfwd_close(struct ssh_channel *c)
2946 if (c && !c->closes) {
2948 * If the channel's remoteid is -1, we have sent
2949 * CHANNEL_OPEN for this channel, but it hasn't even been
2950 * acknowledged by the server. So we must set a close flag
2951 * on it now, and then when the server acks the channel
2952 * open, we can close it then.
2954 if (((int)c->remoteid) != -1) {
2955 if (ssh->version == 1) {
2956 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2959 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2960 ssh2_pkt_adduint32(ssh, c->remoteid);
2964 c->closes = 1; /* sent MSG_CLOSE */
2965 if (c->type == CHAN_X11) {
2967 logevent("Forwarded X11 connection terminated");
2968 } else if (c->type == CHAN_SOCKDATA ||
2969 c->type == CHAN_SOCKDATA_DORMANT) {
2971 logevent("Forwarded port closed");
2976 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2980 if (ssh->version == 1) {
2981 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2982 PKT_INT, c->remoteid,
2983 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2985 * In SSH1 we can return 0 here - implying that forwarded
2986 * connections are never individually throttled - because
2987 * the only circumstance that can cause throttling will be
2988 * the whole SSH connection backing up, in which case
2989 * _everything_ will be throttled as a whole.
2993 ssh2_add_channel_data(c, buf, len);
2994 return ssh2_try_send(c);
2998 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3002 if (ssh->version == 1) {
3003 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3004 c->v.v1.throttling = 0;
3005 ssh1_throttle(ssh, -1);
3008 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3012 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3014 crBegin(ssh->ssh1_protocol_crstate);
3018 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3021 if (ssh->state == SSH_STATE_CLOSED)
3024 if (cfg.agentfwd && agent_exists()) {
3025 logevent("Requesting agent forwarding");
3026 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3030 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3031 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3032 bombout((ssh,"Protocol confusion"));
3034 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3035 logevent("Agent forwarding refused");
3037 logevent("Agent forwarding enabled");
3038 ssh->agentfwd_enabled = TRUE;
3042 if (cfg.x11_forward) {
3043 char proto[20], data[64];
3044 logevent("Requesting X11 forwarding");
3045 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3046 data, sizeof(data));
3047 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3048 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3049 PKT_STR, proto, PKT_STR, data,
3050 PKT_INT, 0, PKT_END);
3052 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3053 PKT_STR, proto, PKT_STR, data, PKT_END);
3058 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3059 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3060 bombout((ssh,"Protocol confusion"));
3062 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3063 logevent("X11 forwarding refused");
3065 logevent("X11 forwarding enabled");
3066 ssh->X11_fwd_enabled = TRUE;
3073 int sport,dport,sserv,dserv;
3074 char sports[256], dports[256], host[256];
3076 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3077 /* Add port forwardings. */
3078 ssh->portfwd_strptr = cfg.portfwd;
3079 while (*ssh->portfwd_strptr) {
3080 type = *ssh->portfwd_strptr++;
3082 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3083 sports[n++] = *ssh->portfwd_strptr++;
3085 if (*ssh->portfwd_strptr == '\t')
3086 ssh->portfwd_strptr++;
3088 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3089 host[n++] = *ssh->portfwd_strptr++;
3091 if (*ssh->portfwd_strptr == ':')
3092 ssh->portfwd_strptr++;
3094 while (*ssh->portfwd_strptr)
3095 dports[n++] = *ssh->portfwd_strptr++;
3097 ssh->portfwd_strptr++;
3098 dport = atoi(dports);
3102 dport = net_service_lookup(dports);
3104 logeventf(ssh, "Service lookup failed for"
3105 " destination port \"%s\"", dports);
3108 sport = atoi(sports);
3112 sport = net_service_lookup(sports);
3114 logeventf(ssh, "Service lookup failed for source"
3115 " port \"%s\"", sports);
3118 if (sport && dport) {
3120 pfd_addforward(host, dport, sport, ssh);
3121 logeventf(ssh, "Local port %.*s%.*s%d%.*s forwarding to"
3122 " %s:%.*s%.*s%d%.*s",
3123 (int)(sserv ? strlen(sports) : 0), sports,
3124 sserv, "(", sport, sserv, ")",
3126 (int)(dserv ? strlen(dports) : 0), dports,
3127 dserv, "(", dport, dserv, ")");
3129 struct ssh_rportfwd *pf;
3130 pf = smalloc(sizeof(*pf));
3131 strcpy(pf->dhost, host);
3133 if (add234(ssh->rportfwds, pf) != pf) {
3135 "Duplicate remote port forwarding to %s:%d",
3139 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3140 " forward to %s:%.*s%.*s%d%.*s",
3141 (int)(sserv ? strlen(sports) : 0), sports,
3142 sserv, "(", sport, sserv, ")",
3144 (int)(dserv ? strlen(dports) : 0), dports,
3145 dserv, "(", dport, dserv, ")");
3146 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3154 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3155 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3156 bombout((ssh,"Protocol confusion"));
3158 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3159 c_write_str(ssh, "Server refused port"
3162 logevent("Remote port forwarding enabled");
3170 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3171 PKT_STR, cfg.termtype,
3172 PKT_INT, ssh->term_height,
3173 PKT_INT, ssh->term_width,
3174 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3175 ssh->state = SSH_STATE_INTERMED;
3179 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3180 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3181 bombout((ssh,"Protocol confusion"));
3183 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3184 c_write_str(ssh, "Server refused to allocate pty\r\n");
3185 ssh->editing = ssh->echoing = 1;
3187 logevent("Allocated pty");
3189 ssh->editing = ssh->echoing = 1;
3192 if (cfg.compression) {
3193 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
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 compress\r\n");
3204 logevent("Started compression");
3205 ssh->v1_compressing = TRUE;
3206 ssh->cs_comp_ctx = zlib_compress_init();
3207 logevent("Initialised zlib (RFC1950) compression");
3208 ssh->sc_comp_ctx = zlib_decompress_init();
3209 logevent("Initialised zlib (RFC1950) decompression");
3213 * Start the shell or command.
3215 * Special case: if the first-choice command is an SSH2
3216 * subsystem (hence not usable here) and the second choice
3217 * exists, we fall straight back to that.
3220 char *cmd = cfg.remote_cmd_ptr;
3222 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3223 cmd = cfg.remote_cmd_ptr2;
3224 ssh->fallback_cmd = TRUE;
3227 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3229 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3230 logevent("Started session");
3233 ssh->state = SSH_STATE_SESSION;
3234 if (ssh->size_needed)
3235 ssh_size(ssh, ssh->term_width, ssh->term_height);
3236 if (ssh->eof_needed)
3237 ssh_special(ssh, TS_EOF);
3240 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3242 ssh->channels = newtree234(ssh_channelcmp);
3246 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3247 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3248 long len = GET_32BIT(ssh->pktin.body);
3250 from_backend(ssh->frontend,
3251 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3252 ssh->pktin.body + 4, len);
3253 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3254 ssh->v1_stdout_throttling = 1;
3255 ssh1_throttle(ssh, +1);
3257 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3258 ssh->state = SSH_STATE_CLOSED;
3259 logevent("Received disconnect request");
3261 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3262 /* Remote side is trying to open a channel to talk to our
3263 * X-Server. Give them back a local channel number. */
3264 struct ssh_channel *c;
3266 logevent("Received X11 connect request");
3267 /* Refuse if X11 forwarding is disabled. */
3268 if (!ssh->X11_fwd_enabled) {
3269 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3270 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3271 logevent("Rejected X11 connect request");
3273 c = smalloc(sizeof(struct ssh_channel));
3276 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3277 ssh->x11auth) != NULL) {
3278 logevent("opening X11 forward connection failed");
3280 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3281 PKT_INT, GET_32BIT(ssh->pktin.body),
3285 ("opening X11 forward connection succeeded");
3286 c->remoteid = GET_32BIT(ssh->pktin.body);
3287 c->localid = alloc_channel_id(ssh);
3289 c->v.v1.throttling = 0;
3290 c->type = CHAN_X11; /* identify channel type */
3291 add234(ssh->channels, c);
3292 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3293 PKT_INT, c->remoteid, PKT_INT,
3294 c->localid, PKT_END);
3295 logevent("Opened X11 forward channel");
3298 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3299 /* Remote side is trying to open a channel to talk to our
3300 * agent. Give them back a local channel number. */
3301 struct ssh_channel *c;
3303 /* Refuse if agent forwarding is disabled. */
3304 if (!ssh->agentfwd_enabled) {
3305 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3306 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3308 c = smalloc(sizeof(struct ssh_channel));
3310 c->remoteid = GET_32BIT(ssh->pktin.body);
3311 c->localid = alloc_channel_id(ssh);
3313 c->v.v1.throttling = 0;
3314 c->type = CHAN_AGENT; /* identify channel type */
3315 c->u.a.lensofar = 0;
3316 add234(ssh->channels, c);
3317 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3318 PKT_INT, c->remoteid, PKT_INT, c->localid,
3321 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3322 /* Remote side is trying to open a channel to talk to a
3323 * forwarded port. Give them back a local channel number. */
3324 struct ssh_channel *c;
3325 struct ssh_rportfwd pf;
3327 char host[256], buf[1024];
3329 c = smalloc(sizeof(struct ssh_channel));
3332 hostsize = GET_32BIT(ssh->pktin.body+4);
3333 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
3334 if (h+1 < host+sizeof(host))
3339 port = GET_32BIT(p);
3341 strcpy(pf.dhost, host);
3344 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3345 sprintf(buf, "Rejected remote port open request for %s:%d",
3348 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3349 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3351 sprintf(buf, "Received remote port open request for %s:%d",
3354 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3357 sprintf(buf, "Port open failed: %s", e);
3360 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3361 PKT_INT, GET_32BIT(ssh->pktin.body),
3364 c->remoteid = GET_32BIT(ssh->pktin.body);
3365 c->localid = alloc_channel_id(ssh);
3367 c->v.v1.throttling = 0;
3368 c->type = CHAN_SOCKDATA; /* identify channel type */
3369 add234(ssh->channels, c);
3370 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3371 PKT_INT, c->remoteid, PKT_INT,
3372 c->localid, PKT_END);
3373 logevent("Forwarded port opened successfully");
3377 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3378 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3379 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3380 struct ssh_channel *c;
3382 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3383 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3384 c->remoteid = localid;
3385 c->type = CHAN_SOCKDATA;
3386 c->v.v1.throttling = 0;
3387 pfd_confirm(c->u.pfd.s);
3390 if (c && c->closes) {
3392 * We have a pending close on this channel,
3393 * which we decided on before the server acked
3394 * the channel open. So now we know the
3395 * remoteid, we can close it again.
3397 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3398 PKT_INT, c->remoteid, PKT_END);
3401 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3402 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3403 struct ssh_channel *c;
3405 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3406 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3407 logevent("Forwarded connection refused by server");
3408 pfd_close(c->u.pfd.s);
3409 del234(ssh->channels, c);
3413 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3414 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3415 /* Remote side closes a channel. */
3416 unsigned i = GET_32BIT(ssh->pktin.body);
3417 struct ssh_channel *c;
3418 c = find234(ssh->channels, &i, ssh_channelfind);
3419 if (c && ((int)c->remoteid) != -1) {
3422 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3424 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3425 logevent("Forwarded X11 connection terminated");
3426 assert(c->u.x11.s != NULL);
3427 x11_close(c->u.x11.s);
3430 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3431 logevent("Forwarded port closed");
3432 assert(c->u.pfd.s != NULL);
3433 pfd_close(c->u.pfd.s);
3437 c->closes |= (closetype << 2); /* seen this message */
3438 if (!(c->closes & closetype)) {
3439 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3441 c->closes |= closetype; /* sent it too */
3444 if (c->closes == 15) {
3445 del234(ssh->channels, c);
3449 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3450 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3451 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3454 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3455 /* Data sent down one of our channels. */
3456 int i = GET_32BIT(ssh->pktin.body);
3457 int len = GET_32BIT(ssh->pktin.body + 4);
3458 unsigned char *p = ssh->pktin.body + 8;
3459 struct ssh_channel *c;
3460 c = find234(ssh->channels, &i, ssh_channelfind);
3465 bufsize = x11_send(c->u.x11.s, p, len);
3468 bufsize = pfd_send(c->u.pfd.s, p, len);
3471 /* Data for an agent message. Buffer it. */
3473 if (c->u.a.lensofar < 4) {
3474 int l = min(4 - c->u.a.lensofar, len);
3475 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3479 c->u.a.lensofar += l;
3481 if (c->u.a.lensofar == 4) {
3483 4 + GET_32BIT(c->u.a.msglen);
3484 c->u.a.message = smalloc(c->u.a.totallen);
3485 memcpy(c->u.a.message, c->u.a.msglen, 4);
3487 if (c->u.a.lensofar >= 4 && len > 0) {
3489 min(c->u.a.totallen - c->u.a.lensofar,
3491 memcpy(c->u.a.message + c->u.a.lensofar, p,
3495 c->u.a.lensofar += l;
3497 if (c->u.a.lensofar == c->u.a.totallen) {
3498 void *reply, *sentreply;
3500 agent_query(c->u.a.message,
3501 c->u.a.totallen, &reply,
3506 /* Fake SSH_AGENT_FAILURE. */
3507 sentreply = "\0\0\0\1\5";
3510 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3511 PKT_INT, c->remoteid,
3513 PKT_DATA, sentreply, replylen,
3517 sfree(c->u.a.message);
3518 c->u.a.lensofar = 0;
3521 bufsize = 0; /* agent channels never back up */
3524 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3525 c->v.v1.throttling = 1;
3526 ssh1_throttle(ssh, +1);
3529 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3530 /* may be from EXEC_SHELL on some servers */
3531 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3532 /* may be from EXEC_SHELL on some servers
3533 * if no pty is available or in other odd cases. Ignore */
3534 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3536 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3537 sprintf(buf, "Server sent command exit status %d",
3540 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3542 * In case `helpful' firewalls or proxies tack
3543 * extra human-readable text on the end of the
3544 * session which we might mistake for another
3545 * encrypted packet, we close the session once
3546 * we've sent EXIT_CONFIRMATION.
3548 ssh->state = SSH_STATE_CLOSED;
3551 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3556 int len = min(inlen, 512);
3557 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3558 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3569 * Utility routine for decoding comma-separated strings in KEXINIT.
3571 static int in_commasep_string(char *needle, char *haystack, int haylen)
3574 if (!needle || !haystack) /* protect against null pointers */
3576 needlen = strlen(needle);
3579 * Is it at the start of the string?
3581 if (haylen >= needlen && /* haystack is long enough */
3582 !memcmp(needle, haystack, needlen) && /* initial match */
3583 (haylen == needlen || haystack[needlen] == ',')
3584 /* either , or EOS follows */
3588 * If not, search for the next comma and resume after that.
3589 * If no comma found, terminate.
3591 while (haylen > 0 && *haystack != ',')
3592 haylen--, haystack++;
3595 haylen--, haystack++; /* skip over comma itself */
3600 * SSH2 key creation method.
3602 static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
3606 /* First 20 bytes. */
3608 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3610 SHA_Bytes(&s, H, 20);
3611 SHA_Bytes(&s, &chr, 1);
3612 SHA_Bytes(&s, sessid, 20);
3613 SHA_Final(&s, keyspace);
3614 /* Next 20 bytes. */
3616 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3618 SHA_Bytes(&s, H, 20);
3619 SHA_Bytes(&s, keyspace, 20);
3620 SHA_Final(&s, keyspace + 20);
3624 * Handle the SSH2 transport layer.
3626 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3628 struct do_ssh2_transport_state {
3629 int nbits, pbits, warn;
3630 Bignum p, g, e, f, K;
3631 int kex_init_value, kex_reply_value;
3632 const struct ssh_mac **maclist;
3634 const struct ssh2_cipher *cscipher_tobe;
3635 const struct ssh2_cipher *sccipher_tobe;
3636 const struct ssh_mac *csmac_tobe;
3637 const struct ssh_mac *scmac_tobe;
3638 const struct ssh_compress *cscomp_tobe;
3639 const struct ssh_compress *sccomp_tobe;
3640 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3641 int hostkeylen, siglen;
3642 void *hkey; /* actual host key */
3643 unsigned char exchange_hash[20];
3644 int n_preferred_ciphers;
3645 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3646 const struct ssh_compress *preferred_comp;
3649 crState(do_ssh2_transport_state);
3651 crBegin(ssh->do_ssh2_transport_crstate);
3653 s->cscipher_tobe = s->sccipher_tobe = NULL;
3654 s->csmac_tobe = s->scmac_tobe = NULL;
3655 s->cscomp_tobe = s->sccomp_tobe = NULL;
3663 * Set up the preferred ciphers. (NULL => warn below here)
3665 s->n_preferred_ciphers = 0;
3666 for (i = 0; i < CIPHER_MAX; i++) {
3667 switch (cfg.ssh_cipherlist[i]) {
3668 case CIPHER_BLOWFISH:
3669 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3672 if (cfg.ssh2_des_cbc) {
3673 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3677 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3680 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3683 /* Flag for later. Don't bother if it's the last in
3685 if (i < CIPHER_MAX - 1) {
3686 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3694 * Set up preferred compression.
3696 if (cfg.compression)
3697 s->preferred_comp = &ssh_zlib;
3699 s->preferred_comp = &ssh_comp_none;
3702 * Be prepared to work around the buggy MAC problem.
3704 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3705 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3707 s->maclist = macs, s->nmacs = lenof(macs);
3711 int i, j, cipherstr_started;
3714 * Construct and send our key exchange packet.
3716 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3717 for (i = 0; i < 16; i++)
3718 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3719 /* List key exchange algorithms. */
3720 ssh2_pkt_addstring_start(ssh);
3721 for (i = 0; i < lenof(kex_algs); i++) {
3722 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3723 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3725 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3726 if (i < lenof(kex_algs) - 1)
3727 ssh2_pkt_addstring_str(ssh, ",");
3729 /* List server host key algorithms. */
3730 ssh2_pkt_addstring_start(ssh);
3731 for (i = 0; i < lenof(hostkey_algs); i++) {
3732 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3733 if (i < lenof(hostkey_algs) - 1)
3734 ssh2_pkt_addstring_str(ssh, ",");
3736 /* List client->server encryption algorithms. */
3737 ssh2_pkt_addstring_start(ssh);
3738 cipherstr_started = 0;
3739 for (i = 0; i < s->n_preferred_ciphers; i++) {
3740 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3741 if (!c) continue; /* warning flag */
3742 for (j = 0; j < c->nciphers; j++) {
3743 if (cipherstr_started)
3744 ssh2_pkt_addstring_str(ssh, ",");
3745 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3746 cipherstr_started = 1;
3749 /* List server->client encryption algorithms. */
3750 ssh2_pkt_addstring_start(ssh);
3751 cipherstr_started = 0;
3752 for (i = 0; i < s->n_preferred_ciphers; i++) {
3753 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3754 if (!c) continue; /* warning flag */
3755 for (j = 0; j < c->nciphers; j++) {
3756 if (cipherstr_started)
3757 ssh2_pkt_addstring_str(ssh, ",");
3758 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3759 cipherstr_started = 1;
3762 /* List client->server MAC algorithms. */
3763 ssh2_pkt_addstring_start(ssh);
3764 for (i = 0; i < s->nmacs; i++) {
3765 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3766 if (i < s->nmacs - 1)
3767 ssh2_pkt_addstring_str(ssh, ",");
3769 /* List server->client MAC algorithms. */
3770 ssh2_pkt_addstring_start(ssh);
3771 for (i = 0; i < s->nmacs; i++) {
3772 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3773 if (i < s->nmacs - 1)
3774 ssh2_pkt_addstring_str(ssh, ",");
3776 /* List client->server compression algorithms. */
3777 ssh2_pkt_addstring_start(ssh);
3778 for (i = 0; i < lenof(compressions) + 1; i++) {
3779 const struct ssh_compress *c =
3780 i == 0 ? s->preferred_comp : compressions[i - 1];
3781 ssh2_pkt_addstring_str(ssh, c->name);
3782 if (i < lenof(compressions))
3783 ssh2_pkt_addstring_str(ssh, ",");
3785 /* List server->client compression algorithms. */
3786 ssh2_pkt_addstring_start(ssh);
3787 for (i = 0; i < lenof(compressions) + 1; i++) {
3788 const struct ssh_compress *c =
3789 i == 0 ? s->preferred_comp : compressions[i - 1];
3790 ssh2_pkt_addstring_str(ssh, c->name);
3791 if (i < lenof(compressions))
3792 ssh2_pkt_addstring_str(ssh, ",");
3794 /* List client->server languages. Empty list. */
3795 ssh2_pkt_addstring_start(ssh);
3796 /* List server->client languages. Empty list. */
3797 ssh2_pkt_addstring_start(ssh);
3798 /* First KEX packet does _not_ follow, because we're not that brave. */
3799 ssh2_pkt_addbool(ssh, FALSE);
3801 ssh2_pkt_adduint32(ssh, 0);
3804 ssh->exhash = ssh->exhashbase;
3805 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3811 if (ssh->pktin.length > 5)
3812 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3815 * Now examine the other side's KEXINIT to see what we're up
3822 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3823 bombout((ssh,"expected key exchange packet from server"));
3827 ssh->hostkey = NULL;
3828 s->cscipher_tobe = NULL;
3829 s->sccipher_tobe = NULL;
3830 s->csmac_tobe = NULL;
3831 s->scmac_tobe = NULL;
3832 s->cscomp_tobe = NULL;
3833 s->sccomp_tobe = NULL;
3834 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3835 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3836 for (i = 0; i < lenof(kex_algs); i++) {
3837 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3838 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3840 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3841 ssh->kex = kex_algs[i];
3845 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3846 for (i = 0; i < lenof(hostkey_algs); i++) {
3847 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3848 ssh->hostkey = hostkey_algs[i];
3852 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3854 for (i = 0; i < s->n_preferred_ciphers; i++) {
3855 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3859 for (j = 0; j < c->nciphers; j++) {
3860 if (in_commasep_string(c->list[j]->name, str, len)) {
3861 s->cscipher_tobe = c->list[j];
3866 if (s->cscipher_tobe) {
3868 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3872 if (!s->cscipher_tobe) {
3873 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3874 str ? str : "(null)"));
3878 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3880 for (i = 0; i < s->n_preferred_ciphers; i++) {
3881 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3885 for (j = 0; j < c->nciphers; j++) {
3886 if (in_commasep_string(c->list[j]->name, str, len)) {
3887 s->sccipher_tobe = c->list[j];
3892 if (s->sccipher_tobe) {
3894 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3898 if (!s->sccipher_tobe) {
3899 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3900 str ? str : "(null)"));
3904 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3905 for (i = 0; i < s->nmacs; i++) {
3906 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3907 s->csmac_tobe = s->maclist[i];
3911 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3912 for (i = 0; i < s->nmacs; i++) {
3913 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3914 s->scmac_tobe = s->maclist[i];
3918 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3919 for (i = 0; i < lenof(compressions) + 1; i++) {
3920 const struct ssh_compress *c =
3921 i == 0 ? s->preferred_comp : compressions[i - 1];
3922 if (in_commasep_string(c->name, str, len)) {
3927 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3928 for (i = 0; i < lenof(compressions) + 1; i++) {
3929 const struct ssh_compress *c =
3930 i == 0 ? s->preferred_comp : compressions[i - 1];
3931 if (in_commasep_string(c->name, str, len)) {
3939 * Work out the number of bits of key we will need from the key
3940 * exchange. We start with the maximum key length of either
3946 csbits = s->cscipher_tobe->keylen;
3947 scbits = s->sccipher_tobe->keylen;
3948 s->nbits = (csbits > scbits ? csbits : scbits);
3950 /* The keys only have 160-bit entropy, since they're based on
3951 * a SHA-1 hash. So cap the key size at 160 bits. */
3956 * If we're doing Diffie-Hellman group exchange, start by
3957 * requesting a group.
3959 if (ssh->kex == &ssh_diffiehellman_gex) {
3960 logevent("Doing Diffie-Hellman group exchange");
3961 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3963 * Work out how big a DH group we will need to allow that
3966 s->pbits = 512 << ((s->nbits - 1) / 64);
3967 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3968 ssh2_pkt_adduint32(ssh, s->pbits);
3972 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3973 bombout((ssh,"expected key exchange group packet from server"));
3976 s->p = ssh2_pkt_getmp(ssh);
3977 s->g = ssh2_pkt_getmp(ssh);
3978 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3979 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3980 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3982 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3983 ssh->kex_ctx = dh_setup_group1();
3984 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3985 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3988 logevent("Doing Diffie-Hellman key exchange");
3990 * Now generate and send e for Diffie-Hellman.
3992 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
3993 ssh2_pkt_init(ssh, s->kex_init_value);
3994 ssh2_pkt_addmp(ssh, s->e);
3998 if (ssh->pktin.type != s->kex_reply_value) {
3999 bombout((ssh,"expected key exchange reply packet from server"));
4002 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4003 s->f = ssh2_pkt_getmp(ssh);
4004 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4006 s->K = dh_find_K(ssh->kex_ctx, s->f);
4008 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4009 if (ssh->kex == &ssh_diffiehellman_gex) {
4010 sha_uint32(&ssh->exhash, s->pbits);
4011 sha_mpint(&ssh->exhash, s->p);
4012 sha_mpint(&ssh->exhash, s->g);
4014 sha_mpint(&ssh->exhash, s->e);
4015 sha_mpint(&ssh->exhash, s->f);
4016 sha_mpint(&ssh->exhash, s->K);
4017 SHA_Final(&ssh->exhash, s->exchange_hash);
4019 dh_cleanup(ssh->kex_ctx);
4022 debug(("Exchange hash is:\n"));
4023 dmemdump(s->exchange_hash, 20);
4026 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4028 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4029 s->exchange_hash, 20)) {
4030 bombout((ssh,"Server's host key did not match the signature supplied"));
4035 * Authenticate remote host: verify host key. (We've already
4036 * checked the signature of the exchange hash.)
4038 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4039 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4040 verify_ssh_host_key(ssh->frontend,
4041 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4042 s->keystr, s->fingerprint);
4043 if (s->first_kex) { /* don't bother logging this in rekeys */
4044 logevent("Host key fingerprint is:");
4045 logevent(s->fingerprint);
4047 sfree(s->fingerprint);
4049 ssh->hostkey->freekey(s->hkey);
4052 * Send SSH2_MSG_NEWKEYS.
4054 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4058 * Expect SSH2_MSG_NEWKEYS from server.
4061 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4062 bombout((ssh,"expected new-keys packet from server"));
4067 * Create and initialise session keys.
4069 if (ssh->cs_cipher_ctx)
4070 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4071 ssh->cscipher = s->cscipher_tobe;
4072 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4074 if (ssh->sc_cipher_ctx)
4075 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4076 ssh->sccipher = s->sccipher_tobe;
4077 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4079 if (ssh->cs_mac_ctx)
4080 ssh->csmac->free_context(ssh->cs_mac_ctx);
4081 ssh->csmac = s->csmac_tobe;
4082 ssh->cs_mac_ctx = ssh->csmac->make_context();
4084 if (ssh->sc_mac_ctx)
4085 ssh->scmac->free_context(ssh->sc_mac_ctx);
4086 ssh->scmac = s->scmac_tobe;
4087 ssh->sc_mac_ctx = ssh->scmac->make_context();
4089 if (ssh->cs_comp_ctx)
4090 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4091 ssh->cscomp = s->cscomp_tobe;
4092 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4094 if (ssh->sc_comp_ctx)
4095 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4096 ssh->sccomp = s->sccomp_tobe;
4097 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4100 * Set IVs after keys. Here we use the exchange hash from the
4101 * _first_ key exchange.
4104 unsigned char keyspace[40];
4106 memcpy(ssh->v2_session_id, s->exchange_hash,
4107 sizeof(s->exchange_hash));
4108 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4109 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4110 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4111 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4112 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4113 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4114 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4115 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4116 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4117 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4118 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4119 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4121 logeventf(ssh, "Initialised %.200s client->server encryption",
4122 ssh->cscipher->text_name);
4123 logeventf(ssh, "Initialised %.200s server->client encryption",
4124 ssh->sccipher->text_name);
4125 if (ssh->cscomp->text_name)
4126 logeventf(ssh, "Initialised %s compression",
4127 ssh->cscomp->text_name);
4128 if (ssh->sccomp->text_name)
4129 logeventf(ssh, "Initialised %s decompression",
4130 ssh->sccomp->text_name);
4133 * If this is the first key exchange phase, we must pass the
4134 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4135 * wants to see it but because it will need time to initialise
4136 * itself before it sees an actual packet. In subsequent key
4137 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4138 * it would only confuse the layer above.
4140 if (!s->first_kex) {
4146 * Now we're encrypting. Begin returning 1 to the protocol main
4147 * function so that other things can run on top of the
4148 * transport. If we ever see a KEXINIT, we must go back to the
4151 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4154 logevent("Server initiated key re-exchange");
4155 goto begin_key_exchange;
4161 * Add data to an SSH2 channel output buffer.
4163 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4166 bufchain_add(&c->v.v2.outbuffer, buf, len);
4170 * Attempt to send data on an SSH2 channel.
4172 static int ssh2_try_send(struct ssh_channel *c)
4176 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4179 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4180 if ((unsigned)len > c->v.v2.remwindow)
4181 len = c->v.v2.remwindow;
4182 if ((unsigned)len > c->v.v2.remmaxpkt)
4183 len = c->v.v2.remmaxpkt;
4184 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4185 ssh2_pkt_adduint32(ssh, c->remoteid);
4186 ssh2_pkt_addstring_start(ssh);
4187 ssh2_pkt_addstring_data(ssh, data, len);
4189 bufchain_consume(&c->v.v2.outbuffer, len);
4190 c->v.v2.remwindow -= len;
4194 * After having sent as much data as we can, return the amount
4197 return bufchain_size(&c->v.v2.outbuffer);
4201 * Potentially enlarge the window on an SSH2 channel.
4203 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4208 * Never send WINDOW_ADJUST for a channel that the remote side
4209 * already thinks it's closed; there's no point, since it won't
4210 * be sending any more data anyway.
4215 if (newwin > c->v.v2.locwindow) {
4216 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4217 ssh2_pkt_adduint32(ssh, c->remoteid);
4218 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4220 c->v.v2.locwindow = newwin;
4225 * Handle the SSH2 userauth and connection layers.
4227 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4229 struct do_ssh2_authconn_state {
4231 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4233 AUTH_KEYBOARD_INTERACTIVE
4237 AUTH_TYPE_PUBLICKEY,
4238 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4239 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4241 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4242 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4244 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4245 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4246 int kbd_inter_running;
4248 int num_prompts, curr_prompt, echo;
4253 void *publickey_blob;
4254 int publickey_bloblen;
4255 unsigned char request[5], *response, *p;
4259 char *pkblob, *alg, *commentp;
4260 int pklen, alglen, commentlen;
4261 int siglen, retlen, len;
4262 char *q, *agentreq, *ret;
4265 crState(do_ssh2_authconn_state);
4267 crBegin(ssh->do_ssh2_authconn_crstate);
4270 * Request userauth protocol, and await a response to it.
4272 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4273 ssh2_pkt_addstring(ssh, "ssh-userauth");
4275 crWaitUntilV(ispkt);
4276 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4277 bombout((ssh,"Server refused user authentication protocol"));
4282 * We repeat this whole loop, including the username prompt,
4283 * until we manage a successful authentication. If the user
4284 * types the wrong _password_, they can be sent back to the
4285 * beginning to try another username, if this is configured on.
4286 * (If they specify a username in the config, they are never
4287 * asked, even if they do give a wrong password.)
4289 * I think this best serves the needs of
4291 * - the people who have no configuration, no keys, and just
4292 * want to try repeated (username,password) pairs until they
4293 * type both correctly
4295 * - people who have keys and configuration but occasionally
4296 * need to fall back to passwords
4298 * - people with a key held in Pageant, who might not have
4299 * logged in to a particular machine before; so they want to
4300 * type a username, and then _either_ their key will be
4301 * accepted, _or_ they will type a password. If they mistype
4302 * the username they will want to be able to get back and
4305 s->username[0] = '\0';
4306 s->got_username = FALSE;
4311 if (s->got_username && !cfg.change_username) {
4313 * We got a username last time round this loop, and
4314 * with change_username turned off we don't try to get
4317 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4318 if (ssh_get_line && !ssh_getline_pw_only) {
4319 if (!ssh_get_line("login as: ",
4320 s->username, sizeof(s->username), FALSE)) {
4322 * get_line failed to get a username.
4325 logevent("No username provided. Abandoning session.");
4326 ssh->state = SSH_STATE_CLOSED;
4330 int ret; /* need not be saved across crReturn */
4331 c_write_str(ssh, "login as: ");
4333 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4335 crWaitUntilV(!ispkt);
4336 ret = process_userpass_input(ssh, in, inlen);
4340 c_write_str(ssh, "\r\n");
4342 s->username[strcspn(s->username, "\n\r")] = '\0';
4345 strncpy(s->username, cfg.username, sizeof(s->username));
4346 s->username[sizeof(s->username)-1] = '\0';
4347 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4348 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4349 c_write_str(ssh, stuff);
4353 s->got_username = TRUE;
4356 * Send an authentication request using method "none": (a)
4357 * just in case it succeeds, and (b) so that we know what
4358 * authentication methods we can usefully try next.
4360 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4362 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4363 ssh2_pkt_addstring(ssh, s->username);
4364 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4365 ssh2_pkt_addstring(ssh, "none"); /* method */
4367 s->type = AUTH_TYPE_NONE;
4369 s->we_are_in = FALSE;
4371 s->tried_pubkey_config = FALSE;
4372 s->tried_agent = FALSE;
4373 s->tried_keyb_inter = FALSE;
4374 s->kbd_inter_running = FALSE;
4375 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4378 logeventf(ssh, "Reading private key file \"%.150s\"", cfg.keyfile);
4379 keytype = key_type(cfg.keyfile);
4380 if (keytype == SSH_KEYTYPE_SSH2) {
4382 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4383 &s->publickey_bloblen);
4386 logeventf(ssh, "Unable to use this key file (%s)",
4387 key_type_to_str(keytype));
4388 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4389 " (%s)\r\n", cfg.keyfile,
4390 key_type_to_str(keytype));
4391 c_write_str(ssh, msgbuf);
4393 s->publickey_blob = NULL;
4396 s->publickey_blob = NULL;
4400 * Wait for the result of the last authentication request.
4403 crWaitUntilV(ispkt);
4404 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4408 * Don't show the banner if we're operating in
4409 * non-verbose non-interactive mode. (It's probably
4410 * a script, which means nobody will read the
4411 * banner _anyway_, and moreover the printing of
4412 * the banner will screw up processing on the
4413 * output of (say) plink.)
4415 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4416 ssh2_pkt_getstring(ssh, &banner, &size);
4418 c_write_untrusted(ssh, banner, size);
4420 crWaitUntilV(ispkt);
4422 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4423 logevent("Access granted");
4424 s->we_are_in = TRUE;
4428 if (s->kbd_inter_running &&
4429 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4431 * This is either a further set-of-prompts packet
4432 * in keyboard-interactive authentication, or it's
4433 * the same one and we came back here with `gotit'
4434 * set. In the former case, we must reset the
4435 * curr_prompt variable.
4439 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4440 bombout((ssh,"Strange packet received during authentication: type %d",
4448 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4449 * we can look at the string in it and know what we can
4450 * helpfully try next.
4452 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4455 ssh2_pkt_getstring(ssh, &methods, &methlen);
4456 s->kbd_inter_running = FALSE;
4457 if (!ssh2_pkt_getbool(ssh)) {
4459 * We have received an unequivocal Access
4460 * Denied. This can translate to a variety of
4463 * - if we'd just tried "none" authentication,
4464 * it's not worth printing anything at all
4466 * - if we'd just tried a public key _offer_,
4467 * the message should be "Server refused our
4468 * key" (or no message at all if the key
4469 * came from Pageant)
4471 * - if we'd just tried anything else, the
4472 * message really should be "Access denied".
4474 * Additionally, if we'd just tried password
4475 * authentication, we should break out of this
4476 * whole loop so as to go back to the username
4479 if (s->type == AUTH_TYPE_NONE) {
4481 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4482 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4483 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4484 c_write_str(ssh, "Server refused our key\r\n");
4485 logevent("Server refused public key");
4486 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4487 /* server declined keyboard-interactive; ignore */
4489 c_write_str(ssh, "Access denied\r\n");
4490 logevent("Access denied");
4491 if (s->type == AUTH_TYPE_PASSWORD) {
4492 s->we_are_in = FALSE;
4497 c_write_str(ssh, "Further authentication required\r\n");
4498 logevent("Further authentication required");
4502 in_commasep_string("publickey", methods, methlen);
4504 in_commasep_string("password", methods, methlen);
4505 s->can_keyb_inter = cfg.try_ki_auth &&
4506 in_commasep_string("keyboard-interactive", methods, methlen);
4510 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4513 * Most password/passphrase prompts will be
4514 * non-echoing, so we set this to 0 by default.
4515 * Exception is that some keyboard-interactive prompts
4516 * can be echoing, in which case we'll set this to 1.
4520 if (!s->method && s->can_pubkey &&
4521 agent_exists() && !s->tried_agent) {
4523 * Attempt public-key authentication using Pageant.
4528 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4529 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4531 s->tried_agent = TRUE;
4533 logevent("Pageant is running. Requesting keys.");
4535 /* Request the keys held by the agent. */
4536 PUT_32BIT(s->request, 1);
4537 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4538 agent_query(s->request, 5, &r, &s->responselen);
4539 s->response = (unsigned char *) r;
4540 if (s->response && s->responselen >= 5 &&
4541 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4542 s->p = s->response + 5;
4543 s->nkeys = GET_32BIT(s->p);
4547 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4550 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4555 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4558 s->pklen = GET_32BIT(s->p);
4560 if (s->publickey_blob &&
4561 s->pklen == s->publickey_bloblen &&
4562 !memcmp(s->p, s->publickey_blob,
4563 s->publickey_bloblen)) {
4564 logevent("This key matches configured key file");
4565 s->tried_pubkey_config = 1;
4569 s->alglen = GET_32BIT(s->pkblob);
4570 s->alg = s->pkblob + 4;
4571 s->commentlen = GET_32BIT(s->p);
4574 s->p += s->commentlen;
4575 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4576 ssh2_pkt_addstring(ssh, s->username);
4577 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4578 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4579 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4580 ssh2_pkt_addstring_start(ssh);
4581 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4582 ssh2_pkt_addstring_start(ssh);
4583 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4586 crWaitUntilV(ispkt);
4587 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4588 logevent("Key refused");
4592 if (flags & FLAG_VERBOSE) {
4593 c_write_str(ssh, "Authenticating with "
4595 c_write(ssh, s->commentp, s->commentlen);
4596 c_write_str(ssh, "\" from agent\r\n");
4600 * Server is willing to accept the key.
4601 * Construct a SIGN_REQUEST.
4603 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4604 ssh2_pkt_addstring(ssh, s->username);
4605 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4606 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4607 ssh2_pkt_addbool(ssh, TRUE);
4608 ssh2_pkt_addstring_start(ssh);
4609 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4610 ssh2_pkt_addstring_start(ssh);
4611 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4613 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4614 s->len = 1; /* message type */
4615 s->len += 4 + s->pklen; /* key blob */
4616 s->len += 4 + s->siglen; /* data to sign */
4617 s->len += 4; /* flags */
4618 s->agentreq = smalloc(4 + s->len);
4619 PUT_32BIT(s->agentreq, s->len);
4620 s->q = s->agentreq + 4;
4621 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4622 PUT_32BIT(s->q, s->pklen);
4624 memcpy(s->q, s->pkblob, s->pklen);
4626 PUT_32BIT(s->q, s->siglen);
4628 /* Now the data to be signed... */
4629 PUT_32BIT(s->q, 20);
4631 memcpy(s->q, ssh->v2_session_id, 20);
4633 memcpy(s->q, ssh->pktout.data + 5,
4634 ssh->pktout.length - 5);
4635 s->q += ssh->pktout.length - 5;
4636 /* And finally the (zero) flags word. */
4638 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4642 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4643 logevent("Sending Pageant's response");
4644 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4646 GET_32BIT(s->ret + 5));
4652 ("Pageant failed to answer challenge");
4662 if (!s->method && s->can_pubkey && s->publickey_blob
4663 && !s->tried_pubkey_config) {
4664 unsigned char *pub_blob;
4665 char *algorithm, *comment;
4668 s->tried_pubkey_config = TRUE;
4670 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4671 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4674 * Try the public key supplied in the configuration.
4676 * First, offer the public blob to see if the server is
4677 * willing to accept it.
4679 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4682 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4683 ssh2_pkt_addstring(ssh, s->username);
4684 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4685 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4686 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4687 ssh2_pkt_addstring(ssh, algorithm);
4688 ssh2_pkt_addstring_start(ssh);
4689 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4691 logevent("Offered public key"); /* FIXME */
4693 crWaitUntilV(ispkt);
4694 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4696 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4697 continue; /* key refused; give up on it */
4700 logevent("Offer of public key accepted");
4702 * Actually attempt a serious authentication using
4705 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4706 sprintf(s->pwprompt,
4707 "Passphrase for key \"%.100s\": ",
4713 c_write_str(ssh, "Authenticating with public key \"");
4714 c_write_str(ssh, comment);
4715 c_write_str(ssh, "\"\r\n");
4716 s->method = AUTH_PUBLICKEY_FILE;
4720 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4721 s->method = AUTH_KEYBOARD_INTERACTIVE;
4722 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4723 s->tried_keyb_inter = TRUE;
4725 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4726 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4728 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4729 ssh2_pkt_addstring(ssh, s->username);
4730 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4731 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4732 ssh2_pkt_addstring(ssh, ""); /* lang */
4733 ssh2_pkt_addstring(ssh, "");
4736 crWaitUntilV(ispkt);
4737 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4738 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4740 logevent("Keyboard-interactive authentication refused");
4741 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4745 s->kbd_inter_running = TRUE;
4749 if (s->kbd_inter_running) {
4750 s->method = AUTH_KEYBOARD_INTERACTIVE;
4751 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4752 s->tried_keyb_inter = TRUE;
4754 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4755 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4757 if (s->curr_prompt == 0) {
4759 * We've got a fresh USERAUTH_INFO_REQUEST.
4760 * Display header data, and start going through
4763 char *name, *inst, *lang;
4764 int name_len, inst_len, lang_len;
4766 ssh2_pkt_getstring(ssh, &name, &name_len);
4767 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4768 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4770 c_write_untrusted(ssh, name, name_len);
4771 c_write_str(ssh, "\r\n");
4774 c_write_untrusted(ssh, inst, inst_len);
4775 c_write_str(ssh, "\r\n");
4777 s->num_prompts = ssh2_pkt_getuint32(ssh);
4781 * If there are prompts remaining in the packet,
4782 * display one and get a response.
4784 if (s->curr_prompt < s->num_prompts) {
4788 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4789 if (prompt_len > 0) {
4790 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4791 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4792 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4795 "<server failed to send prompt>: ");
4797 s->echo = ssh2_pkt_getbool(ssh);
4803 if (!s->method && s->can_passwd) {
4804 s->method = AUTH_PASSWORD;
4805 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4806 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4807 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4814 if (!ssh_get_line(s->pwprompt, s->password,
4815 sizeof(s->password), TRUE)) {
4817 * get_line failed to get a password (for
4818 * example because one was supplied on the
4819 * command line which has already failed to
4822 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4823 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4824 ssh2_pkt_addstring(ssh, "No more passwords available"
4826 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4828 logevent("Unable to authenticate");
4829 connection_fatal(ssh->frontend,
4830 "Unable to authenticate");
4831 ssh->state = SSH_STATE_CLOSED;
4835 int ret; /* need not be saved across crReturn */
4836 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4839 setup_userpass_input(ssh, s->password,
4840 sizeof(s->password), s->echo);
4842 crWaitUntilV(!ispkt);
4843 ret = process_userpass_input(ssh, in, inlen);
4847 c_write_str(ssh, "\r\n");
4851 if (s->method == AUTH_PUBLICKEY_FILE) {
4853 * We have our passphrase. Now try the actual authentication.
4855 struct ssh2_userkey *key;
4857 key = ssh2_load_userkey(cfg.keyfile, s->password);
4858 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4859 if (key == SSH2_WRONG_PASSPHRASE) {
4860 c_write_str(ssh, "Wrong passphrase\r\n");
4861 s->tried_pubkey_config = FALSE;
4863 c_write_str(ssh, "Unable to load private key\r\n");
4864 s->tried_pubkey_config = TRUE;
4866 /* Send a spurious AUTH_NONE to return to the top. */
4867 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4868 ssh2_pkt_addstring(ssh, s->username);
4869 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4870 ssh2_pkt_addstring(ssh, "none"); /* method */
4872 s->type = AUTH_TYPE_NONE;
4874 unsigned char *pkblob, *sigblob, *sigdata;
4875 int pkblob_len, sigblob_len, sigdata_len;
4878 * We have loaded the private key and the server
4879 * has announced that it's willing to accept it.
4880 * Hallelujah. Generate a signature and send it.
4882 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4883 ssh2_pkt_addstring(ssh, s->username);
4884 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4885 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4886 ssh2_pkt_addbool(ssh, TRUE);
4887 ssh2_pkt_addstring(ssh, key->alg->name);
4888 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4889 ssh2_pkt_addstring_start(ssh);
4890 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
4893 * The data to be signed is:
4897 * followed by everything so far placed in the
4900 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4901 sigdata = smalloc(sigdata_len);
4902 PUT_32BIT(sigdata, 20);
4903 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4904 memcpy(sigdata + 24, ssh->pktout.data + 5,
4905 ssh->pktout.length - 5);
4906 sigblob = key->alg->sign(key->data, sigdata,
4907 sigdata_len, &sigblob_len);
4908 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4909 sigblob, sigblob_len);
4915 s->type = AUTH_TYPE_PUBLICKEY;
4917 } else if (s->method == AUTH_PASSWORD) {
4919 * We send the password packet lumped tightly together with
4920 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4921 * string long enough to make the total length of the two
4922 * packets constant. This should ensure that a passive
4923 * listener doing traffic analyis can't work out the length
4926 * For this to work, we need an assumption about the
4927 * maximum length of the password packet. I think 256 is
4928 * pretty conservative. Anyone using a password longer than
4929 * that probably doesn't have much to worry about from
4930 * people who find out how long their password is!
4932 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4933 ssh2_pkt_addstring(ssh, s->username);
4934 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4935 ssh2_pkt_addstring(ssh, "password");
4936 ssh2_pkt_addbool(ssh, FALSE);
4937 ssh2_pkt_addstring(ssh, s->password);
4938 ssh2_pkt_defer(ssh);
4940 * We'll include a string that's an exact multiple of the
4941 * cipher block size. If the cipher is NULL for some
4942 * reason, we don't do this trick at all because we gain
4945 if (ssh->cscipher) {
4948 stringlen = (256 - ssh->deferred_len);
4949 stringlen += ssh->cscipher->blksize - 1;
4950 stringlen -= (stringlen % ssh->cscipher->blksize);
4953 * Temporarily disable actual compression,
4954 * so we can guarantee to get this string
4955 * exactly the length we want it. The
4956 * compression-disabling routine should
4957 * return an integer indicating how many
4958 * bytes we should adjust our string length
4962 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4964 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4965 ssh2_pkt_addstring_start(ssh);
4966 for (i = 0; i < stringlen; i++) {
4967 char c = (char) random_byte();
4968 ssh2_pkt_addstring_data(ssh, &c, 1);
4970 ssh2_pkt_defer(ssh);
4972 ssh_pkt_defersend(ssh);
4973 logevent("Sent password");
4974 s->type = AUTH_TYPE_PASSWORD;
4975 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4976 if (s->curr_prompt == 0) {
4977 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4978 ssh2_pkt_adduint32(ssh, s->num_prompts);
4980 if (s->need_pw) { /* only add pw if we just got one! */
4981 ssh2_pkt_addstring(ssh, s->password);
4982 memset(s->password, 0, sizeof(s->password));
4985 if (s->curr_prompt >= s->num_prompts) {
4989 * If there are prompts remaining, we set
4990 * `gotit' so that we won't attempt to get
4991 * another packet. Then we go back round the
4992 * loop and will end up retrieving another
4993 * prompt out of the existing packet. Funky or
4998 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5000 c_write_str(ssh, "No supported authentication methods"
5001 " left to try!\r\n");
5002 logevent("No supported authentications offered."
5004 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5005 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5006 ssh2_pkt_addstring(ssh, "No supported authentication"
5007 " methods available");
5008 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5010 ssh->state = SSH_STATE_CLOSED;
5014 } while (!s->we_are_in);
5017 * Now we're authenticated for the connection protocol. The
5018 * connection protocol will automatically have started at this
5019 * point; there's no need to send SERVICE_REQUEST.
5023 * So now create a channel with a session in it.
5025 ssh->channels = newtree234(ssh_channelcmp);
5026 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5027 ssh->mainchan->ssh = ssh;
5028 ssh->mainchan->localid = alloc_channel_id(ssh);
5029 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5030 ssh2_pkt_addstring(ssh, "session");
5031 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5032 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5033 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5034 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5036 crWaitUntilV(ispkt);
5037 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5038 bombout((ssh,"Server refused to open a session"));
5040 /* FIXME: error data comes back in FAILURE packet */
5042 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5043 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5046 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5047 ssh->mainchan->type = CHAN_MAINSESSION;
5048 ssh->mainchan->closes = 0;
5049 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5050 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5051 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5052 add234(ssh->channels, ssh->mainchan);
5053 logevent("Opened channel for session");
5056 * Potentially enable X11 forwarding.
5058 if (cfg.x11_forward) {
5059 char proto[20], data[64];
5060 logevent("Requesting X11 forwarding");
5061 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5062 data, sizeof(data));
5063 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5064 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5065 ssh2_pkt_addstring(ssh, "x11-req");
5066 ssh2_pkt_addbool(ssh, 1); /* want reply */
5067 ssh2_pkt_addbool(ssh, 0); /* many connections */
5068 ssh2_pkt_addstring(ssh, proto);
5069 ssh2_pkt_addstring(ssh, data);
5070 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5074 crWaitUntilV(ispkt);
5075 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5076 unsigned i = ssh2_pkt_getuint32(ssh);
5077 struct ssh_channel *c;
5078 c = find234(ssh->channels, &i, ssh_channelfind);
5080 continue; /* nonexistent channel */
5081 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5083 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5085 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5086 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5087 bombout((ssh,"Unexpected response to X11 forwarding request:"
5088 " packet type %d", ssh->pktin.type));
5091 logevent("X11 forwarding refused");
5093 logevent("X11 forwarding enabled");
5094 ssh->X11_fwd_enabled = TRUE;
5099 * Enable port forwardings.
5104 int sport,dport,sserv,dserv;
5105 char sports[256], dports[256], host[256];
5107 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5108 /* Add port forwardings. */
5109 ssh->portfwd_strptr = cfg.portfwd;
5110 while (*ssh->portfwd_strptr) {
5111 type = *ssh->portfwd_strptr++;
5113 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5114 sports[n++] = *ssh->portfwd_strptr++;
5116 if (*ssh->portfwd_strptr == '\t')
5117 ssh->portfwd_strptr++;
5119 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5120 host[n++] = *ssh->portfwd_strptr++;
5122 if (*ssh->portfwd_strptr == ':')
5123 ssh->portfwd_strptr++;
5125 while (*ssh->portfwd_strptr)
5126 dports[n++] = *ssh->portfwd_strptr++;
5128 ssh->portfwd_strptr++;
5129 dport = atoi(dports);
5133 dport = net_service_lookup(dports);
5135 logeventf(ssh, "Service lookup failed for destination"
5136 " port \"%s\"", dports);
5139 sport = atoi(sports);
5143 sport = net_service_lookup(sports);
5145 logeventf(ssh, "Service lookup failed for source"
5146 " port \"%s\"", sports);
5149 if (sport && dport) {
5151 pfd_addforward(host, dport, sport, ssh);
5152 logeventf(ssh, "Local port %.*s%.*s%d%.*s forwarding to"
5153 " %s:%.*s%.*s%d%.*s",
5154 (int)(sserv ? strlen(sports) : 0), sports,
5155 sserv, "(", sport, sserv, ")",
5157 (int)(dserv ? strlen(dports) : 0), dports,
5158 dserv, "(", dport, dserv, ")");
5160 struct ssh_rportfwd *pf;
5161 pf = smalloc(sizeof(*pf));
5162 strcpy(pf->dhost, host);
5165 if (add234(ssh->rportfwds, pf) != pf) {
5166 logeventf(ssh, "Duplicate remote port forwarding"
5167 " to %s:%d", host, dport);
5170 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
5171 " forward to %s:%.*s%.*s%d%.*s",
5172 (int)(sserv ? strlen(sports) : 0), sports,
5173 sserv, "(", sport, sserv, ")",
5175 (int)(dserv ? strlen(dports) : 0), dports,
5176 dserv, "(", dport, dserv, ")");
5177 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5178 ssh2_pkt_addstring(ssh, "tcpip-forward");
5179 ssh2_pkt_addbool(ssh, 1);/* want reply */
5180 if (cfg.rport_acceptall)
5181 ssh2_pkt_addstring(ssh, "0.0.0.0");
5183 ssh2_pkt_addstring(ssh, "127.0.0.1");
5184 ssh2_pkt_adduint32(ssh, sport);
5188 crWaitUntilV(ispkt);
5189 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5190 unsigned i = ssh2_pkt_getuint32(ssh);
5191 struct ssh_channel *c;
5192 c = find234(ssh->channels, &i, ssh_channelfind);
5194 continue;/* nonexistent channel */
5195 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5197 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5199 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5200 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5201 bombout((ssh,"Unexpected response to port "
5202 "forwarding request: packet type %d",
5206 logevent("Server refused this port forwarding");
5208 logevent("Remote port forwarding enabled");
5217 * Potentially enable agent forwarding.
5219 if (cfg.agentfwd && agent_exists()) {
5220 logevent("Requesting OpenSSH-style agent forwarding");
5221 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5222 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5223 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5224 ssh2_pkt_addbool(ssh, 1); /* want reply */
5228 crWaitUntilV(ispkt);
5229 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5230 unsigned i = ssh2_pkt_getuint32(ssh);
5231 struct ssh_channel *c;
5232 c = find234(ssh->channels, &i, ssh_channelfind);
5234 continue; /* nonexistent channel */
5235 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5237 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5239 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5240 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5241 bombout((ssh,"Unexpected response to agent forwarding request:"
5242 " packet type %d", ssh->pktin.type));
5245 logevent("Agent forwarding refused");
5247 logevent("Agent forwarding enabled");
5248 ssh->agentfwd_enabled = TRUE;
5253 * Now allocate a pty for the session.
5256 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5257 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5258 ssh2_pkt_addstring(ssh, "pty-req");
5259 ssh2_pkt_addbool(ssh, 1); /* want reply */
5260 ssh2_pkt_addstring(ssh, cfg.termtype);
5261 ssh2_pkt_adduint32(ssh, ssh->term_width);
5262 ssh2_pkt_adduint32(ssh, ssh->term_height);
5263 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5264 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5265 ssh2_pkt_addstring_start(ssh);
5266 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5268 ssh->state = SSH_STATE_INTERMED;
5271 crWaitUntilV(ispkt);
5272 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5273 unsigned i = ssh2_pkt_getuint32(ssh);
5274 struct ssh_channel *c;
5275 c = find234(ssh->channels, &i, ssh_channelfind);
5277 continue; /* nonexistent channel */
5278 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5280 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5282 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5283 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5284 bombout((ssh,"Unexpected response to pty request:"
5285 " packet type %d", ssh->pktin.type));
5288 c_write_str(ssh, "Server refused to allocate pty\r\n");
5289 ssh->editing = ssh->echoing = 1;
5291 logevent("Allocated pty");
5294 ssh->editing = ssh->echoing = 1;
5298 * Start a shell or a remote command. We may have to attempt
5299 * this twice if the config data has provided a second choice
5306 if (ssh->fallback_cmd) {
5307 subsys = cfg.ssh_subsys2;
5308 cmd = cfg.remote_cmd_ptr2;
5310 subsys = cfg.ssh_subsys;
5311 cmd = cfg.remote_cmd_ptr;
5314 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5315 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5317 ssh2_pkt_addstring(ssh, "subsystem");
5318 ssh2_pkt_addbool(ssh, 1); /* want reply */
5319 ssh2_pkt_addstring(ssh, cmd);
5321 ssh2_pkt_addstring(ssh, "exec");
5322 ssh2_pkt_addbool(ssh, 1); /* want reply */
5323 ssh2_pkt_addstring(ssh, cmd);
5325 ssh2_pkt_addstring(ssh, "shell");
5326 ssh2_pkt_addbool(ssh, 1); /* want reply */
5330 crWaitUntilV(ispkt);
5331 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5332 unsigned i = ssh2_pkt_getuint32(ssh);
5333 struct ssh_channel *c;
5334 c = find234(ssh->channels, &i, ssh_channelfind);
5336 continue; /* nonexistent channel */
5337 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5339 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5340 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5341 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5342 bombout((ssh,"Unexpected response to shell/command request:"
5343 " packet type %d", ssh->pktin.type));
5347 * We failed to start the command. If this is the
5348 * fallback command, we really are finished; if it's
5349 * not, and if the fallback command exists, try falling
5350 * back to it before complaining.
5352 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5353 logevent("Primary command failed; attempting fallback");
5354 ssh->fallback_cmd = TRUE;
5357 bombout((ssh,"Server refused to start a shell/command"));
5360 logevent("Started a shell/command");
5365 ssh->state = SSH_STATE_SESSION;
5366 if (ssh->size_needed)
5367 ssh_size(ssh, ssh->term_width, ssh->term_height);
5368 if (ssh->eof_needed)
5369 ssh_special(ssh, TS_EOF);
5375 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5379 s->try_send = FALSE;
5381 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5382 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5385 unsigned i = ssh2_pkt_getuint32(ssh);
5386 struct ssh_channel *c;
5387 c = find234(ssh->channels, &i, ssh_channelfind);
5389 continue; /* nonexistent channel */
5390 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5391 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5392 continue; /* extended but not stderr */
5393 ssh2_pkt_getstring(ssh, &data, &length);
5396 c->v.v2.locwindow -= length;
5398 case CHAN_MAINSESSION:
5400 from_backend(ssh->frontend, ssh->pktin.type ==
5401 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5405 bufsize = x11_send(c->u.x11.s, data, length);
5408 bufsize = pfd_send(c->u.pfd.s, data, length);
5411 while (length > 0) {
5412 if (c->u.a.lensofar < 4) {
5413 int l = min(4 - c->u.a.lensofar, length);
5414 memcpy(c->u.a.msglen + c->u.a.lensofar,
5418 c->u.a.lensofar += l;
5420 if (c->u.a.lensofar == 4) {
5422 4 + GET_32BIT(c->u.a.msglen);
5423 c->u.a.message = smalloc(c->u.a.totallen);
5424 memcpy(c->u.a.message, c->u.a.msglen, 4);
5426 if (c->u.a.lensofar >= 4 && length > 0) {
5428 min(c->u.a.totallen - c->u.a.lensofar,
5430 memcpy(c->u.a.message + c->u.a.lensofar,
5434 c->u.a.lensofar += l;
5436 if (c->u.a.lensofar == c->u.a.totallen) {
5437 void *reply, *sentreply;
5439 agent_query(c->u.a.message,
5440 c->u.a.totallen, &reply,
5445 /* Fake SSH_AGENT_FAILURE. */
5446 sentreply = "\0\0\0\1\5";
5449 ssh2_add_channel_data(c, sentreply, replylen);
5453 sfree(c->u.a.message);
5454 c->u.a.lensofar = 0;
5461 * If we are not buffering too much data,
5462 * enlarge the window again at the remote side.
5464 if (bufsize < OUR_V2_WINSIZE)
5465 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5467 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5468 unsigned i = ssh2_pkt_getuint32(ssh);
5469 struct ssh_channel *c;
5471 c = find234(ssh->channels, &i, ssh_channelfind);
5473 continue; /* nonexistent channel */
5475 if (c->type == CHAN_X11) {
5477 * Remote EOF on an X11 channel means we should
5478 * wrap up and close the channel ourselves.
5480 x11_close(c->u.x11.s);
5482 } else if (c->type == CHAN_AGENT) {
5484 } else if (c->type == CHAN_SOCKDATA) {
5485 pfd_close(c->u.pfd.s);
5488 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5489 unsigned i = ssh2_pkt_getuint32(ssh);
5490 struct ssh_channel *c;
5492 c = find234(ssh->channels, &i, ssh_channelfind);
5493 if (!c || ((int)c->remoteid) == -1) {
5494 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5495 c ? "half-open" : "nonexistent", i));
5497 /* Do pre-close processing on the channel. */
5499 case CHAN_MAINSESSION:
5500 break; /* nothing to see here, move along */
5502 if (c->u.x11.s != NULL)
5503 x11_close(c->u.x11.s);
5510 if (c->u.pfd.s != NULL)
5511 pfd_close(c->u.pfd.s);
5515 if (c->closes == 0) {
5516 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5517 ssh2_pkt_adduint32(ssh, c->remoteid);
5520 del234(ssh->channels, c);
5521 bufchain_clear(&c->v.v2.outbuffer);
5525 * See if that was the last channel left open.
5527 if (count234(ssh->channels) == 0) {
5530 * We used to send SSH_MSG_DISCONNECT here,
5531 * because I'd believed that _every_ conforming
5532 * SSH2 connection had to end with a disconnect
5533 * being sent by at least one side; apparently
5534 * I was wrong and it's perfectly OK to
5535 * unceremoniously slam the connection shut
5536 * when you're done, and indeed OpenSSH feels
5537 * this is more polite than sending a
5538 * DISCONNECT. So now we don't.
5540 logevent("All channels closed. Disconnecting");
5541 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5542 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5543 ssh2_pkt_addstring(ssh, "All open channels closed");
5544 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5547 ssh->state = SSH_STATE_CLOSED;
5550 continue; /* remote sends close; ignore (FIXME) */
5551 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5552 unsigned i = ssh2_pkt_getuint32(ssh);
5553 struct ssh_channel *c;
5554 c = find234(ssh->channels, &i, ssh_channelfind);
5556 continue; /* nonexistent channel */
5557 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5559 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5560 unsigned i = ssh2_pkt_getuint32(ssh);
5561 struct ssh_channel *c;
5562 c = find234(ssh->channels, &i, ssh_channelfind);
5564 continue; /* nonexistent channel */
5565 if (c->type != CHAN_SOCKDATA_DORMANT)
5566 continue; /* dunno why they're confirming this */
5567 c->remoteid = ssh2_pkt_getuint32(ssh);
5568 c->type = CHAN_SOCKDATA;
5569 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5570 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5572 pfd_confirm(c->u.pfd.s);
5575 * We have a pending close on this channel,
5576 * which we decided on before the server acked
5577 * the channel open. So now we know the
5578 * remoteid, we can close it again.
5580 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5581 ssh2_pkt_adduint32(ssh, c->remoteid);
5584 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5585 unsigned i = ssh2_pkt_getuint32(ssh);
5586 struct ssh_channel *c;
5587 c = find234(ssh->channels, &i, ssh_channelfind);
5589 continue; /* nonexistent channel */
5590 if (c->type != CHAN_SOCKDATA_DORMANT)
5591 continue; /* dunno why they're failing this */
5593 logevent("Forwarded connection refused by server");
5595 pfd_close(c->u.pfd.s);
5597 del234(ssh->channels, c);
5599 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5602 int typelen, want_reply;
5603 struct ssh_channel *c;
5605 localid = ssh2_pkt_getuint32(ssh);
5606 ssh2_pkt_getstring(ssh, &type, &typelen);
5607 want_reply = ssh2_pkt_getbool(ssh);
5610 * First, check that the channel exists. Otherwise,
5611 * we can instantly disconnect with a rude message.
5613 c = find234(ssh->channels, &localid, ssh_channelfind);
5616 sprintf(buf, "Received channel request for nonexistent"
5617 " channel %d", localid);
5619 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5620 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5621 ssh2_pkt_addstring(ssh, buf);
5622 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5624 connection_fatal("%s", buf);
5625 ssh->state = SSH_STATE_CLOSED;
5630 * Having got the channel number, we now look at
5631 * the request type string to see if it's something
5634 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5635 c == ssh->mainchan) {
5636 /* We recognise "exit-status" on the primary channel. */
5638 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5639 sprintf(buf, "Server sent command exit status %d",
5643 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5644 ssh2_pkt_adduint32(ssh, c->remoteid);
5649 * This is a channel request we don't know
5650 * about, so we now either ignore the request
5651 * or respond with CHANNEL_FAILURE, depending
5655 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5656 ssh2_pkt_adduint32(ssh, c->remoteid);
5660 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5662 int typelen, want_reply;
5664 ssh2_pkt_getstring(ssh, &type, &typelen);
5665 want_reply = ssh2_pkt_getbool(ssh);
5668 * We currently don't support any global requests
5669 * at all, so we either ignore the request or
5670 * respond with REQUEST_FAILURE, depending on
5674 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5677 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5681 struct ssh_channel *c;
5682 unsigned remid, winsize, pktsize;
5683 ssh2_pkt_getstring(ssh, &type, &typelen);
5684 c = smalloc(sizeof(struct ssh_channel));
5687 remid = ssh2_pkt_getuint32(ssh);
5688 winsize = ssh2_pkt_getuint32(ssh);
5689 pktsize = ssh2_pkt_getuint32(ssh);
5691 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5692 if (!ssh->X11_fwd_enabled)
5693 error = "X11 forwarding is not enabled";
5694 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5695 ssh->x11auth) != NULL) {
5696 error = "Unable to open an X11 connection";
5700 } else if (typelen == 15 &&
5701 !memcmp(type, "forwarded-tcpip", 15)) {
5702 struct ssh_rportfwd pf, *realpf;
5705 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5706 pf.sport = ssh2_pkt_getuint32(ssh);
5707 realpf = find234(ssh->rportfwds, &pf, NULL);
5708 if (realpf == NULL) {
5709 error = "Remote port is not recognised";
5711 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5713 logeventf(ssh, "Received remote port open request"
5714 " for %s:%d", realpf->dhost, realpf->dport);
5716 logeventf(ssh, "Port open failed: %s", e);
5717 error = "Port open failed";
5719 logevent("Forwarded port opened successfully");
5720 c->type = CHAN_SOCKDATA;
5723 } else if (typelen == 22 &&
5724 !memcmp(type, "auth-agent@openssh.com", 3)) {
5725 if (!ssh->agentfwd_enabled)
5726 error = "Agent forwarding is not enabled";
5728 c->type = CHAN_AGENT; /* identify channel type */
5729 c->u.a.lensofar = 0;
5732 error = "Unsupported channel type requested";
5735 c->remoteid = remid;
5737 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5738 ssh2_pkt_adduint32(ssh, c->remoteid);
5739 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5740 ssh2_pkt_addstring(ssh, error);
5741 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5745 c->localid = alloc_channel_id(ssh);
5747 c->v.v2.locwindow = OUR_V2_WINSIZE;
5748 c->v.v2.remwindow = winsize;
5749 c->v.v2.remmaxpkt = pktsize;
5750 bufchain_init(&c->v.v2.outbuffer);
5751 add234(ssh->channels, c);
5752 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5753 ssh2_pkt_adduint32(ssh, c->remoteid);
5754 ssh2_pkt_adduint32(ssh, c->localid);
5755 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5756 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5760 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5765 * We have spare data. Add it to the channel buffer.
5767 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5772 struct ssh_channel *c;
5774 * Try to send data on all channels if we can.
5776 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5777 int bufsize = ssh2_try_send(c);
5780 case CHAN_MAINSESSION:
5781 /* stdin need not receive an unthrottle
5782 * notification since it will be polled */
5785 x11_unthrottle(c->u.x11.s);
5788 /* agent sockets are request/response and need no
5789 * buffer management */
5792 pfd_unthrottle(c->u.pfd.s);
5804 * Handle the top-level SSH2 protocol.
5806 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5808 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5810 do_ssh2_authconn(ssh, in, inlen, ispkt);
5814 * Called to set up the connection.
5816 * Returns an error message, or NULL on success.
5818 static char *ssh_init(void *frontend_handle, void **backend_handle,
5819 char *host, int port, char **realhost, int nodelay)
5824 ssh = smalloc(sizeof(*ssh));
5827 ssh->v1_cipher_ctx = NULL;
5828 ssh->crcda_ctx = NULL;
5829 ssh->cscipher = NULL;
5830 ssh->cs_cipher_ctx = NULL;
5831 ssh->sccipher = NULL;
5832 ssh->sc_cipher_ctx = NULL;
5834 ssh->cs_mac_ctx = NULL;
5836 ssh->sc_mac_ctx = NULL;
5838 ssh->cs_comp_ctx = NULL;
5840 ssh->sc_comp_ctx = NULL;
5842 ssh->hostkey = NULL;
5844 ssh->state = SSH_STATE_PREPACKET;
5845 ssh->size_needed = FALSE;
5846 ssh->eof_needed = FALSE;
5850 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5851 ssh->pktin = ssh->pktout = empty;
5853 ssh->deferred_send_data = NULL;
5854 ssh->deferred_len = 0;
5855 ssh->deferred_size = 0;
5856 ssh->fallback_cmd = 0;
5858 ssh->x11auth = NULL;
5859 ssh->v1_compressing = FALSE;
5860 ssh->v2_outgoing_sequence = 0;
5861 ssh->ssh1_rdpkt_crstate = 0;
5862 ssh->ssh2_rdpkt_crstate = 0;
5863 ssh->do_ssh_init_crstate = 0;
5864 ssh->ssh_gotdata_crstate = 0;
5865 ssh->ssh1_protocol_crstate = 0;
5866 ssh->do_ssh1_login_crstate = 0;
5867 ssh->do_ssh2_transport_crstate = 0;
5868 ssh->do_ssh2_authconn_crstate = 0;
5869 ssh->do_ssh_init_state = NULL;
5870 ssh->do_ssh1_login_state = NULL;
5871 ssh->do_ssh2_transport_state = NULL;
5872 ssh->do_ssh2_authconn_state = NULL;
5873 ssh->mainchan = NULL;
5874 ssh->throttled_all = 0;
5875 ssh->v1_stdout_throttling = 0;
5877 *backend_handle = ssh;
5880 if (crypto_startup() == 0)
5881 return "Microsoft high encryption pack not installed!";
5884 ssh->frontend = frontend_handle;
5885 ssh->term_width = cfg.width;
5886 ssh->term_height = cfg.height;
5891 ssh->v1_throttle_count = 0;
5892 ssh->overall_bufsize = 0;
5893 ssh->fallback_cmd = 0;
5895 p = connect_to_host(ssh, host, port, realhost, nodelay);
5903 * Called to send data down the Telnet connection.
5905 static int ssh_send(void *handle, char *buf, int len)
5907 Ssh ssh = (Ssh) handle;
5909 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5912 ssh->protocol(ssh, buf, len, 0);
5914 return ssh_sendbuffer(ssh);
5918 * Called to query the current amount of buffered stdin data.
5920 static int ssh_sendbuffer(void *handle)
5922 Ssh ssh = (Ssh) handle;
5925 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5929 * If the SSH socket itself has backed up, add the total backup
5930 * size on that to any individual buffer on the stdin channel.
5933 if (ssh->throttled_all)
5934 override_value = ssh->overall_bufsize;
5936 if (ssh->version == 1) {
5937 return override_value;
5938 } else if (ssh->version == 2) {
5939 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5940 return override_value;
5942 return (override_value +
5943 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5950 * Called to set the size of the window from SSH's POV.
5952 static void ssh_size(void *handle, int width, int height)
5954 Ssh ssh = (Ssh) handle;
5956 ssh->term_width = width;
5957 ssh->term_height = height;
5959 switch (ssh->state) {
5960 case SSH_STATE_BEFORE_SIZE:
5961 case SSH_STATE_PREPACKET:
5962 case SSH_STATE_CLOSED:
5963 break; /* do nothing */
5964 case SSH_STATE_INTERMED:
5965 ssh->size_needed = TRUE; /* buffer for later */
5967 case SSH_STATE_SESSION:
5969 if (ssh->version == 1) {
5970 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
5971 PKT_INT, ssh->term_height,
5972 PKT_INT, ssh->term_width,
5973 PKT_INT, 0, PKT_INT, 0, PKT_END);
5975 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5976 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5977 ssh2_pkt_addstring(ssh, "window-change");
5978 ssh2_pkt_addbool(ssh, 0);
5979 ssh2_pkt_adduint32(ssh, ssh->term_width);
5980 ssh2_pkt_adduint32(ssh, ssh->term_height);
5981 ssh2_pkt_adduint32(ssh, 0);
5982 ssh2_pkt_adduint32(ssh, 0);
5991 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5992 * can send an EOF and collect resulting output (e.g. `plink
5995 static void ssh_special(void *handle, Telnet_Special code)
5997 Ssh ssh = (Ssh) handle;
5999 if (code == TS_EOF) {
6000 if (ssh->state != SSH_STATE_SESSION) {
6002 * Buffer the EOF in case we are pre-SESSION, so we can
6003 * send it as soon as we reach SESSION.
6006 ssh->eof_needed = TRUE;
6009 if (ssh->version == 1) {
6010 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6012 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6013 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6016 logevent("Sent EOF message");
6017 } else if (code == TS_PING) {
6018 if (ssh->state == SSH_STATE_CLOSED
6019 || ssh->state == SSH_STATE_PREPACKET) return;
6020 if (ssh->version == 1) {
6021 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6022 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6024 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6025 ssh2_pkt_addstring_start(ssh);
6033 void *new_sock_channel(void *handle, Socket s)
6035 Ssh ssh = (Ssh) handle;
6036 struct ssh_channel *c;
6037 c = smalloc(sizeof(struct ssh_channel));
6041 c->remoteid = -1; /* to be set when open confirmed */
6042 c->localid = alloc_channel_id(ssh);
6044 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6046 bufchain_init(&c->v.v2.outbuffer);
6047 add234(ssh->channels, c);
6053 * This is called when stdout/stderr (the entity to which
6054 * from_backend sends data) manages to clear some backlog.
6056 void ssh_unthrottle(void *handle, int bufsize)
6058 Ssh ssh = (Ssh) handle;
6059 if (ssh->version == 1) {
6060 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6061 ssh->v1_stdout_throttling = 0;
6062 ssh1_throttle(ssh, -1);
6065 if (ssh->mainchan && ssh->mainchan->closes == 0)
6066 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6070 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6072 struct ssh_channel *c = (struct ssh_channel *)channel;
6075 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6077 if (ssh->version == 1) {
6078 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6079 PKT_INT, c->localid,
6082 //PKT_STR, <org:orgport>,
6085 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6086 ssh2_pkt_addstring(ssh, "direct-tcpip");
6087 ssh2_pkt_adduint32(ssh, c->localid);
6088 c->v.v2.locwindow = OUR_V2_WINSIZE;
6089 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6090 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6091 ssh2_pkt_addstring(ssh, hostname);
6092 ssh2_pkt_adduint32(ssh, port);
6094 * We make up values for the originator data; partly it's
6095 * too much hassle to keep track, and partly I'm not
6096 * convinced the server should be told details like that
6097 * about my local network configuration.
6099 ssh2_pkt_addstring(ssh, "client-side-connection");
6100 ssh2_pkt_adduint32(ssh, 0);
6106 static Socket ssh_socket(void *handle)
6108 Ssh ssh = (Ssh) handle;
6112 static int ssh_sendok(void *handle)
6114 Ssh ssh = (Ssh) handle;
6115 return ssh->send_ok;
6118 static int ssh_ldisc(void *handle, int option)
6120 Ssh ssh = (Ssh) handle;
6121 if (option == LD_ECHO)
6122 return ssh->echoing;
6123 if (option == LD_EDIT)
6124 return ssh->editing;
6128 static void ssh_provide_ldisc(void *handle, void *ldisc)
6130 Ssh ssh = (Ssh) handle;
6134 static void ssh_provide_logctx(void *handle, void *logctx)
6136 Ssh ssh = (Ssh) handle;
6137 ssh->logctx = logctx;
6140 static int ssh_return_exitcode(void *handle)
6142 Ssh ssh = (Ssh) handle;
6143 return ssh->exitcode;
6147 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6148 * that fails. This variable is the means by which scp.c can reach
6149 * into the SSH code and find out which one it got.
6151 extern int ssh_fallback_cmd(void *handle)
6153 Ssh ssh = (Ssh) handle;
6154 return ssh->fallback_cmd;
6157 Backend ssh_backend = {
6164 ssh_return_exitcode,