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, char *srcaddr,
303 int port, void *backhandle);
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) logevent(ssh->frontend, s)
643 /* logevent, only printf-formatted. */
644 void logeventf(Ssh ssh, char *fmt, ...)
650 buf = dupvprintf(fmt, ap);
656 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
657 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
658 logeventf msg, connection_fatal msg )
660 static int ssh_channelcmp(void *av, void *bv)
662 struct ssh_channel *a = (struct ssh_channel *) av;
663 struct ssh_channel *b = (struct ssh_channel *) bv;
664 if (a->localid < b->localid)
666 if (a->localid > b->localid)
670 static int ssh_channelfind(void *av, void *bv)
672 unsigned *a = (unsigned *) av;
673 struct ssh_channel *b = (struct ssh_channel *) bv;
681 static int ssh_rportcmp_ssh1(void *av, void *bv)
683 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
684 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
686 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
687 return i < 0 ? -1 : +1;
688 if (a->dport > b->dport)
690 if (a->dport < b->dport)
695 static int ssh_rportcmp_ssh2(void *av, void *bv)
697 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
698 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
700 if (a->sport > b->sport)
702 if (a->sport < b->sport)
707 static int alloc_channel_id(Ssh ssh)
709 const unsigned CHANNEL_NUMBER_OFFSET = 256;
710 unsigned low, high, mid;
712 struct ssh_channel *c;
715 * First-fit allocation of channel numbers: always pick the
716 * lowest unused one. To do this, binary-search using the
717 * counted B-tree to find the largest channel ID which is in a
718 * contiguous sequence from the beginning. (Precisely
719 * everything in that sequence must have ID equal to its tree
720 * index plus CHANNEL_NUMBER_OFFSET.)
722 tsize = count234(ssh->channels);
726 while (high - low > 1) {
727 mid = (high + low) / 2;
728 c = index234(ssh->channels, mid);
729 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
730 low = mid; /* this one is fine */
732 high = mid; /* this one is past it */
735 * Now low points to either -1, or the tree index of the
736 * largest ID in the initial sequence.
739 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
740 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
742 return low + 1 + CHANNEL_NUMBER_OFFSET;
745 static void c_write(Ssh ssh, char *buf, int len)
747 if ((flags & FLAG_STDERR)) {
749 for (i = 0; i < len; i++)
751 fputc(buf[i], stderr);
754 from_backend(ssh->frontend, 1, buf, len);
757 static void c_write_untrusted(Ssh ssh, char *buf, int len)
760 for (i = 0; i < len; i++) {
762 c_write(ssh, "\r\n", 2);
763 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
764 c_write(ssh, buf + i, 1);
768 static void c_write_str(Ssh ssh, char *buf)
770 c_write(ssh, buf, strlen(buf));
774 * Collect incoming data in the incoming packet buffer.
775 * Decipher and verify the packet when it is completely read.
776 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
777 * Update the *data and *datalen variables.
778 * Return the additional nr of bytes needed, or 0 when
779 * a complete packet is available.
781 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
783 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
785 crBegin(ssh->ssh1_rdpkt_crstate);
790 ssh->pktin.length = 0;
792 for (st->i = st->len = 0; st->i < 4; st->i++) {
793 while ((*datalen) == 0)
795 st->len = (st->len << 8) + **data;
796 (*data)++, (*datalen)--;
799 st->pad = 8 - (st->len % 8);
800 st->biglen = st->len + st->pad;
801 ssh->pktin.length = st->len - 5;
803 if (ssh->pktin.maxlen < st->biglen) {
804 ssh->pktin.maxlen = st->biglen;
805 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
808 st->to_read = st->biglen;
809 st->p = ssh->pktin.data;
810 while (st->to_read > 0) {
811 st->chunk = st->to_read;
812 while ((*datalen) == 0)
813 crReturn(st->to_read);
814 if (st->chunk > (*datalen))
815 st->chunk = (*datalen);
816 memcpy(st->p, *data, st->chunk);
818 *datalen -= st->chunk;
820 st->to_read -= st->chunk;
823 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
825 bombout((ssh,"Network attack (CRC compensation) detected!"));
830 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
832 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
833 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
834 if (st->gotcrc != st->realcrc) {
835 bombout((ssh,"Incorrect CRC received on packet"));
839 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
841 if (ssh->v1_compressing) {
842 unsigned char *decompblk;
844 zlib_decompress_block(ssh->sc_comp_ctx,
845 ssh->pktin.body - 1, ssh->pktin.length + 1,
846 &decompblk, &decomplen);
848 if (ssh->pktin.maxlen < st->pad + decomplen) {
849 ssh->pktin.maxlen = st->pad + decomplen;
850 ssh->pktin.data = srealloc(ssh->pktin.data,
851 ssh->pktin.maxlen + APIEXTRA);
852 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
855 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
857 ssh->pktin.length = decomplen - 1;
860 ssh->pktin.type = ssh->pktin.body[-1];
863 log_packet(ssh->logctx,
864 PKT_INCOMING, ssh->pktin.type,
865 ssh1_pkt_type(ssh->pktin.type),
866 ssh->pktin.body, ssh->pktin.length);
868 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
869 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
870 ssh->pktin.type == SSH1_MSG_DEBUG ||
871 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
872 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
873 long stringlen = GET_32BIT(ssh->pktin.body);
874 if (stringlen + 4 != ssh->pktin.length) {
875 bombout((ssh,"Received data packet with bogus string length"));
880 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
881 /* log debug message */
883 int stringlen = GET_32BIT(ssh->pktin.body);
884 strcpy(buf, "Remote debug message: ");
887 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
888 buf[8 + stringlen] = '\0';
891 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
896 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
897 /* log reason code in disconnect message */
899 unsigned msglen = GET_32BIT(ssh->pktin.body);
901 strcpy(buf, "Remote sent disconnect: ");
902 nowlen = strlen(buf);
903 if (msglen > sizeof(buf) - nowlen - 1)
904 msglen = sizeof(buf) - nowlen - 1;
905 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
906 buf[nowlen + msglen] = '\0';
907 /* logevent(buf); (this is now done within the bombout macro) */
908 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
915 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
917 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
919 crBegin(ssh->ssh2_rdpkt_crstate);
923 ssh->pktin.length = 0;
925 st->cipherblk = ssh->sccipher->blksize;
928 if (st->cipherblk < 8)
931 if (ssh->pktin.maxlen < st->cipherblk) {
932 ssh->pktin.maxlen = st->cipherblk;
933 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
937 * Acquire and decrypt the first block of the packet. This will
938 * contain the length and padding details.
940 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
941 while ((*datalen) == 0)
942 crReturn(st->cipherblk - st->i);
943 ssh->pktin.data[st->i] = *(*data)++;
948 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
949 ssh->pktin.data, st->cipherblk);
952 * Now get the length and padding figures.
954 st->len = GET_32BIT(ssh->pktin.data);
955 st->pad = ssh->pktin.data[4];
958 * _Completely_ silly lengths should be stomped on before they
959 * do us any more damage.
961 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
962 bombout((ssh,"Incoming packet was garbled on decryption"));
967 * This enables us to deduce the payload length.
969 st->payload = st->len - st->pad - 1;
971 ssh->pktin.length = st->payload + 5;
974 * So now we can work out the total packet length.
976 st->packetlen = st->len + 4;
977 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
980 * Adjust memory allocation if packet is too big.
982 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
983 ssh->pktin.maxlen = st->packetlen + st->maclen;
984 ssh->pktin.data = srealloc(ssh->pktin.data,
985 ssh->pktin.maxlen + APIEXTRA);
989 * Read and decrypt the remainder of the packet.
991 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
993 while ((*datalen) == 0)
994 crReturn(st->packetlen + st->maclen - st->i);
995 ssh->pktin.data[st->i] = *(*data)++;
998 /* Decrypt everything _except_ the MAC. */
1000 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1001 ssh->pktin.data + st->cipherblk,
1002 st->packetlen - st->cipherblk);
1008 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1009 st->incoming_sequence)) {
1010 bombout((ssh,"Incorrect MAC received on packet"));
1013 st->incoming_sequence++; /* whether or not we MACed */
1016 * Decompress packet payload.
1019 unsigned char *newpayload;
1022 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1023 ssh->pktin.data + 5, ssh->pktin.length - 5,
1024 &newpayload, &newlen)) {
1025 if (ssh->pktin.maxlen < newlen + 5) {
1026 ssh->pktin.maxlen = newlen + 5;
1027 ssh->pktin.data = srealloc(ssh->pktin.data,
1028 ssh->pktin.maxlen + APIEXTRA);
1030 ssh->pktin.length = 5 + newlen;
1031 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1036 ssh->pktin.savedpos = 6;
1037 ssh->pktin.type = ssh->pktin.data[5];
1040 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1041 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1042 ssh->pktin.data+6, ssh->pktin.length-6);
1044 switch (ssh->pktin.type) {
1046 * These packets we must handle instantly.
1048 case SSH2_MSG_DISCONNECT:
1050 /* log reason code in disconnect message */
1053 int reason = GET_32BIT(ssh->pktin.data + 6);
1054 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1056 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1057 buf = dupprintf("Received disconnect message (%s)",
1058 ssh2_disconnect_reasons[reason]);
1060 buf = dupprintf("Received disconnect message (unknown"
1061 " type %d)", reason);
1065 buf = dupprintf("Disconnection message text: %n%.*s",
1066 &nowlen, msglen, ssh->pktin.data + 14);
1068 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1070 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1071 ssh2_disconnect_reasons[reason] : "unknown",
1077 case SSH2_MSG_IGNORE:
1079 case SSH2_MSG_DEBUG:
1081 /* log the debug message */
1083 /* int display = ssh->pktin.body[6]; */
1084 int stringlen = GET_32BIT(ssh->pktin.data+7);
1086 strcpy(buf, "Remote debug message: ");
1087 prefix = strlen(buf);
1088 if (stringlen > (int)(sizeof(buf)-prefix-1))
1089 stringlen = sizeof(buf)-prefix-1;
1090 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1091 buf[prefix + stringlen] = '\0';
1094 goto next_packet; /* FIXME: print the debug message */
1097 * These packets we need do nothing about here.
1099 case SSH2_MSG_UNIMPLEMENTED:
1100 case SSH2_MSG_SERVICE_REQUEST:
1101 case SSH2_MSG_SERVICE_ACCEPT:
1102 case SSH2_MSG_KEXINIT:
1103 case SSH2_MSG_NEWKEYS:
1104 case SSH2_MSG_KEXDH_INIT:
1105 case SSH2_MSG_KEXDH_REPLY:
1106 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1107 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1108 case SSH2_MSG_KEX_DH_GEX_INIT:
1109 case SSH2_MSG_KEX_DH_GEX_REPLY:
1110 case SSH2_MSG_USERAUTH_REQUEST:
1111 case SSH2_MSG_USERAUTH_FAILURE:
1112 case SSH2_MSG_USERAUTH_SUCCESS:
1113 case SSH2_MSG_USERAUTH_BANNER:
1114 case SSH2_MSG_USERAUTH_PK_OK:
1115 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1116 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1117 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1118 case SSH2_MSG_GLOBAL_REQUEST:
1119 case SSH2_MSG_REQUEST_SUCCESS:
1120 case SSH2_MSG_REQUEST_FAILURE:
1121 case SSH2_MSG_CHANNEL_OPEN:
1122 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1123 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1124 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1125 case SSH2_MSG_CHANNEL_DATA:
1126 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1127 case SSH2_MSG_CHANNEL_EOF:
1128 case SSH2_MSG_CHANNEL_CLOSE:
1129 case SSH2_MSG_CHANNEL_REQUEST:
1130 case SSH2_MSG_CHANNEL_SUCCESS:
1131 case SSH2_MSG_CHANNEL_FAILURE:
1135 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1138 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1139 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1147 static void ssh1_pktout_size(Ssh ssh, int len)
1151 len += 5; /* type and CRC */
1152 pad = 8 - (len % 8);
1155 ssh->pktout.length = len - 5;
1156 if (ssh->pktout.maxlen < biglen) {
1157 ssh->pktout.maxlen = biglen;
1159 /* Allocate enough buffer space for extra block
1160 * for MS CryptEncrypt() */
1161 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1163 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1166 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1169 static void s_wrpkt_start(Ssh ssh, int type, int len)
1171 ssh1_pktout_size(ssh, len);
1172 ssh->pktout.type = type;
1175 static int s_wrpkt_prepare(Ssh ssh)
1177 int pad, len, biglen, i;
1180 ssh->pktout.body[-1] = ssh->pktout.type;
1183 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1184 ssh1_pkt_type(ssh->pktout.type),
1185 ssh->pktout.body, ssh->pktout.length);
1187 if (ssh->v1_compressing) {
1188 unsigned char *compblk;
1190 zlib_compress_block(ssh->cs_comp_ctx,
1191 ssh->pktout.body - 1, ssh->pktout.length + 1,
1192 &compblk, &complen);
1193 ssh1_pktout_size(ssh, complen - 1);
1194 memcpy(ssh->pktout.body - 1, compblk, complen);
1198 len = ssh->pktout.length + 5; /* type and CRC */
1199 pad = 8 - (len % 8);
1202 for (i = 0; i < pad; i++)
1203 ssh->pktout.data[i + 4] = random_byte();
1204 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1205 PUT_32BIT(ssh->pktout.data + biglen, crc);
1206 PUT_32BIT(ssh->pktout.data, len);
1209 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1214 static void s_wrpkt(Ssh ssh)
1217 len = s_wrpkt_prepare(ssh);
1218 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1219 if (backlog > SSH_MAX_BACKLOG)
1220 ssh_throttle_all(ssh, 1, backlog);
1223 static void s_wrpkt_defer(Ssh ssh)
1226 len = s_wrpkt_prepare(ssh);
1227 if (ssh->deferred_len + len > ssh->deferred_size) {
1228 ssh->deferred_size = ssh->deferred_len + len + 128;
1229 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1230 ssh->deferred_size);
1232 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1233 ssh->deferred_len += len;
1237 * Construct a packet with the specified contents.
1239 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1241 unsigned char *p, *argp, argchar;
1242 unsigned long argint;
1243 int pktlen, argtype, arglen;
1247 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1250 (void) va_arg(ap1, int);
1254 (void) va_arg(ap1, int);
1258 (void) va_arg(ap1, unsigned char *);
1259 arglen = va_arg(ap1, int);
1263 argp = va_arg(ap1, unsigned char *);
1264 arglen = strlen(argp);
1265 pktlen += 4 + arglen;
1268 bn = va_arg(ap1, Bignum);
1269 pktlen += ssh1_bignum_length(bn);
1276 s_wrpkt_start(ssh, pkttype, pktlen);
1277 p = ssh->pktout.body;
1279 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1282 argint = va_arg(ap2, int);
1283 PUT_32BIT(p, argint);
1287 argchar = (unsigned char) va_arg(ap2, int);
1292 argp = va_arg(ap2, unsigned char *);
1293 arglen = va_arg(ap2, int);
1294 memcpy(p, argp, arglen);
1298 argp = va_arg(ap2, unsigned char *);
1299 arglen = strlen(argp);
1300 PUT_32BIT(p, arglen);
1301 memcpy(p + 4, argp, arglen);
1305 bn = va_arg(ap2, Bignum);
1306 p += ssh1_write_bignum(p, bn);
1312 static void send_packet(Ssh ssh, int pkttype, ...)
1315 va_start(ap1, pkttype);
1316 va_start(ap2, pkttype);
1317 construct_packet(ssh, pkttype, ap1, ap2);
1321 static void defer_packet(Ssh ssh, int pkttype, ...)
1324 va_start(ap1, pkttype);
1325 va_start(ap2, pkttype);
1326 construct_packet(ssh, pkttype, ap1, ap2);
1330 static int ssh_versioncmp(char *a, char *b)
1333 unsigned long av, bv;
1335 av = strtoul(a, &ae, 10);
1336 bv = strtoul(b, &be, 10);
1338 return (av < bv ? -1 : +1);
1343 av = strtoul(ae, &ae, 10);
1344 bv = strtoul(be, &be, 10);
1346 return (av < bv ? -1 : +1);
1351 * Utility routines for putting an SSH-protocol `string' and
1352 * `uint32' into a SHA state.
1355 static void sha_string(SHA_State * s, void *str, int len)
1357 unsigned char lenblk[4];
1358 PUT_32BIT(lenblk, len);
1359 SHA_Bytes(s, lenblk, 4);
1360 SHA_Bytes(s, str, len);
1363 static void sha_uint32(SHA_State * s, unsigned i)
1365 unsigned char intblk[4];
1366 PUT_32BIT(intblk, i);
1367 SHA_Bytes(s, intblk, 4);
1371 * SSH2 packet construction functions.
1373 static void ssh2_pkt_ensure(Ssh ssh, int length)
1375 if (ssh->pktout.maxlen < length) {
1376 ssh->pktout.maxlen = length + 256;
1377 ssh->pktout.data = srealloc(ssh->pktout.data,
1378 ssh->pktout.maxlen + APIEXTRA);
1379 if (!ssh->pktout.data)
1380 fatalbox("Out of memory");
1383 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1385 ssh->pktout.length += len;
1386 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1387 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1389 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1391 ssh2_pkt_adddata(ssh, &byte, 1);
1393 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1395 ssh->pktout.length = 5;
1396 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1398 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1400 ssh2_pkt_adddata(ssh, &value, 1);
1402 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1405 PUT_32BIT(x, value);
1406 ssh2_pkt_adddata(ssh, x, 4);
1408 static void ssh2_pkt_addstring_start(Ssh ssh)
1410 ssh2_pkt_adduint32(ssh, 0);
1411 ssh->pktout.savedpos = ssh->pktout.length;
1413 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1415 ssh2_pkt_adddata(ssh, data, strlen(data));
1416 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1417 ssh->pktout.length - ssh->pktout.savedpos);
1419 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1421 ssh2_pkt_adddata(ssh, data, len);
1422 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1423 ssh->pktout.length - ssh->pktout.savedpos);
1425 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1427 ssh2_pkt_addstring_start(ssh);
1428 ssh2_pkt_addstring_str(ssh, data);
1430 static char *ssh2_mpint_fmt(Bignum b, int *len)
1433 int i, n = (bignum_bitcount(b) + 7) / 8;
1436 fatalbox("out of memory");
1438 for (i = 1; i <= n; i++)
1439 p[i] = bignum_byte(b, n - i);
1441 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1443 memmove(p, p + i, n + 1 - i);
1447 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1451 p = ssh2_mpint_fmt(b, &len);
1452 ssh2_pkt_addstring_start(ssh);
1453 ssh2_pkt_addstring_data(ssh, p, len);
1458 * Construct an SSH2 final-form packet: compress it, encrypt it,
1459 * put the MAC on it. Final packet, ready to be sent, is stored in
1460 * ssh->pktout.data. Total length is returned.
1462 static int ssh2_pkt_construct(Ssh ssh)
1464 int cipherblk, maclen, padding, i;
1467 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1468 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1469 ssh->pktout.data + 6, ssh->pktout.length - 6);
1472 * Compress packet payload.
1475 unsigned char *newpayload;
1478 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1479 ssh->pktout.length - 5,
1480 &newpayload, &newlen)) {
1481 ssh->pktout.length = 5;
1482 ssh2_pkt_adddata(ssh, newpayload, newlen);
1488 * Add padding. At least four bytes, and must also bring total
1489 * length (minus MAC) up to a multiple of the block size.
1491 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1492 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1495 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1496 maclen = ssh->csmac ? ssh->csmac->len : 0;
1497 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1498 ssh->pktout.data[4] = padding;
1499 for (i = 0; i < padding; i++)
1500 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1501 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1503 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1504 ssh->pktout.length + padding,
1505 ssh->v2_outgoing_sequence);
1506 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1509 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1510 ssh->pktout.data, ssh->pktout.length + padding);
1512 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1513 return ssh->pktout.length + padding + maclen;
1517 * Construct and send an SSH2 packet immediately.
1519 static void ssh2_pkt_send(Ssh ssh)
1523 len = ssh2_pkt_construct(ssh);
1524 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1525 if (backlog > SSH_MAX_BACKLOG)
1526 ssh_throttle_all(ssh, 1, backlog);
1530 * Construct an SSH2 packet and add it to a deferred data block.
1531 * Useful for sending multiple packets in a single sk_write() call,
1532 * to prevent a traffic-analysing listener from being able to work
1533 * out the length of any particular packet (such as the password
1536 * Note that because SSH2 sequence-numbers its packets, this can
1537 * NOT be used as an m4-style `defer' allowing packets to be
1538 * constructed in one order and sent in another.
1540 static void ssh2_pkt_defer(Ssh ssh)
1542 int len = ssh2_pkt_construct(ssh);
1543 if (ssh->deferred_len + len > ssh->deferred_size) {
1544 ssh->deferred_size = ssh->deferred_len + len + 128;
1545 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1546 ssh->deferred_size);
1548 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1549 ssh->deferred_len += len;
1553 * Send the whole deferred data block constructed by
1554 * ssh2_pkt_defer() or SSH1's defer_packet().
1556 static void ssh_pkt_defersend(Ssh ssh)
1559 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1560 ssh->deferred_len = ssh->deferred_size = 0;
1561 sfree(ssh->deferred_send_data);
1562 ssh->deferred_send_data = NULL;
1563 if (backlog > SSH_MAX_BACKLOG)
1564 ssh_throttle_all(ssh, 1, backlog);
1568 void bndebug(char *string, Bignum b)
1572 p = ssh2_mpint_fmt(b, &len);
1573 debug(("%s", string));
1574 for (i = 0; i < len; i++)
1575 debug((" %02x", p[i]));
1581 static void sha_mpint(SHA_State * s, Bignum b)
1585 p = ssh2_mpint_fmt(b, &len);
1586 sha_string(s, p, len);
1591 * SSH2 packet decode functions.
1593 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1595 unsigned long value;
1596 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1597 return 0; /* arrgh, no way to decline (FIXME?) */
1598 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1599 ssh->pktin.savedpos += 4;
1602 static int ssh2_pkt_getbool(Ssh ssh)
1604 unsigned long value;
1605 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1606 return 0; /* arrgh, no way to decline (FIXME?) */
1607 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1608 ssh->pktin.savedpos++;
1611 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1616 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1618 len = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1622 ssh->pktin.savedpos += 4;
1623 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1625 *p = ssh->pktin.data + ssh->pktin.savedpos;
1626 ssh->pktin.savedpos += *length;
1628 static Bignum ssh2_pkt_getmp(Ssh ssh)
1634 ssh2_pkt_getstring(ssh, &p, &length);
1638 bombout((ssh,"internal error: Can't handle negative mpints"));
1641 b = bignum_from_bytes(p, length);
1646 * Helper function to add an SSH2 signature blob to a packet.
1647 * Expects to be shown the public key blob as well as the signature
1648 * blob. Normally works just like ssh2_pkt_addstring, but will
1649 * fiddle with the signature packet if necessary for
1650 * BUG_SSH2_RSA_PADDING.
1652 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1653 void *sigblob_v, int sigblob_len)
1655 unsigned char *pkblob = (unsigned char *)pkblob_v;
1656 unsigned char *sigblob = (unsigned char *)sigblob_v;
1658 /* dmemdump(pkblob, pkblob_len); */
1659 /* dmemdump(sigblob, sigblob_len); */
1662 * See if this is in fact an ssh-rsa signature and a buggy
1663 * server; otherwise we can just do this the easy way.
1665 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1666 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1667 int pos, len, siglen;
1670 * Find the byte length of the modulus.
1673 pos = 4+7; /* skip over "ssh-rsa" */
1674 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1675 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1676 pos += 4; /* find modulus itself */
1677 while (len > 0 && pkblob[pos] == 0)
1679 /* debug(("modulus length is %d\n", len)); */
1682 * Now find the signature integer.
1684 pos = 4+7; /* skip over "ssh-rsa" */
1685 siglen = GET_32BIT(sigblob+pos);
1686 /* debug(("signature length is %d\n", siglen)); */
1688 if (len != siglen) {
1689 unsigned char newlen[4];
1690 ssh2_pkt_addstring_start(ssh);
1691 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1692 /* dmemdump(sigblob, pos); */
1693 pos += 4; /* point to start of actual sig */
1694 PUT_32BIT(newlen, len);
1695 ssh2_pkt_addstring_data(ssh, newlen, 4);
1696 /* dmemdump(newlen, 4); */
1698 while (len-- > siglen) {
1699 ssh2_pkt_addstring_data(ssh, newlen, 1);
1700 /* dmemdump(newlen, 1); */
1702 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1703 /* dmemdump(sigblob+pos, siglen); */
1707 /* Otherwise fall through and do it the easy way. */
1710 ssh2_pkt_addstring_start(ssh);
1711 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1715 * Examine the remote side's version string and compare it against
1716 * a list of known buggy implementations.
1718 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1720 char *imp; /* pointer to implementation part */
1722 imp += strcspn(imp, "-");
1724 imp += strcspn(imp, "-");
1727 ssh->remote_bugs = 0;
1729 if (cfg.sshbug_ignore1 == BUG_ON ||
1730 (cfg.sshbug_ignore1 == BUG_AUTO &&
1731 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1732 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1733 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1735 * These versions don't support SSH1_MSG_IGNORE, so we have
1736 * to use a different defence against password length
1739 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1740 logevent("We believe remote version has SSH1 ignore bug");
1743 if (cfg.sshbug_plainpw1 == BUG_ON ||
1744 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1745 (!strcmp(imp, "Cisco-1.25")))) {
1747 * These versions need a plain password sent; they can't
1748 * handle having a null and a random length of data after
1751 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1752 logevent("We believe remote version needs a plain SSH1 password");
1755 if (cfg.sshbug_rsa1 == BUG_ON ||
1756 (cfg.sshbug_rsa1 == BUG_AUTO &&
1757 (!strcmp(imp, "Cisco-1.25")))) {
1759 * These versions apparently have no clue whatever about
1760 * RSA authentication and will panic and die if they see
1761 * an AUTH_RSA message.
1763 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1764 logevent("We believe remote version can't handle RSA authentication");
1767 if (cfg.sshbug_hmac2 == BUG_ON ||
1768 (cfg.sshbug_hmac2 == BUG_AUTO &&
1769 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
1770 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
1771 wc_match("2.1 *", imp)))) {
1773 * These versions have the HMAC bug.
1775 ssh->remote_bugs |= BUG_SSH2_HMAC;
1776 logevent("We believe remote version has SSH2 HMAC bug");
1779 if (cfg.sshbug_derivekey2 == BUG_ON ||
1780 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1781 (wc_match("2.0.0*", imp) || wc_match("2.0.1[01]*", imp) ))) {
1783 * These versions have the key-derivation bug (failing to
1784 * include the literal shared secret in the hashes that
1785 * generate the keys).
1787 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1788 logevent("We believe remote version has SSH2 key-derivation bug");
1791 if (cfg.sshbug_rsapad2 == BUG_ON ||
1792 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1793 (wc_match("OpenSSH_2.[5-9]*", imp) ||
1794 wc_match("OpenSSH_3.[0-2]*", imp)))) {
1796 * These versions have the SSH2 RSA padding bug.
1798 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1799 logevent("We believe remote version has SSH2 RSA padding bug");
1802 if (cfg.sshbug_dhgex2 == BUG_ON) {
1804 * User specified the SSH2 DH GEX bug.
1806 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1807 logevent("We believe remote version has SSH2 DH group exchange bug");
1811 static int do_ssh_init(Ssh ssh, unsigned char c)
1813 struct do_ssh_init_state {
1821 crState(do_ssh_init_state);
1823 crBegin(ssh->do_ssh_init_crstate);
1825 /* Search for the string "SSH-" in the input. */
1828 static const int transS[] = { 1, 2, 2, 1 };
1829 static const int transH[] = { 0, 0, 3, 0 };
1830 static const int transminus[] = { 0, 0, 0, -1 };
1832 s->i = transS[s->i];
1834 s->i = transH[s->i];
1836 s->i = transminus[s->i];
1841 crReturn(1); /* get another character */
1845 s->vstring = smalloc(s->vstrsize);
1846 strcpy(s->vstring, "SSH-");
1850 crReturn(1); /* get another char */
1851 if (s->vslen >= s->vstrsize - 1) {
1853 s->vstring = srealloc(s->vstring, s->vstrsize);
1855 s->vstring[s->vslen++] = c;
1858 s->version[s->i] = '\0';
1860 } else if (s->i < sizeof(s->version) - 1)
1861 s->version[s->i++] = c;
1862 } else if (c == '\n')
1866 ssh->agentfwd_enabled = FALSE;
1867 ssh->rdpkt2_state.incoming_sequence = 0;
1869 s->vstring[s->vslen] = 0;
1870 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1873 vlog = smalloc(20 + s->vslen);
1874 sprintf(vlog, "Server version: %s", s->vstring);
1878 ssh_detect_bugs(ssh, s->vstring);
1881 * Decide which SSH protocol version to support.
1884 /* Anything strictly below "2.0" means protocol 1 is supported. */
1885 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1886 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1887 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1889 if (cfg.sshprot == 0 && !s->proto1) {
1890 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
1893 if (cfg.sshprot == 3 && !s->proto2) {
1894 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
1898 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1902 char verstring[80], vlog[100];
1903 sprintf(verstring, "SSH-2.0-%s", sshver);
1904 SHA_Init(&ssh->exhashbase);
1906 * Hash our version string and their version string.
1908 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1909 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1910 sprintf(vlog, "We claim version: %s", verstring);
1912 strcat(verstring, "\n");
1913 logevent("Using SSH protocol version 2");
1914 sk_write(ssh->s, verstring, strlen(verstring));
1915 ssh->protocol = ssh2_protocol;
1917 ssh->s_rdpkt = ssh2_rdpkt;
1922 char verstring[80], vlog[100];
1923 sprintf(verstring, "SSH-%s-%s",
1924 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1926 sprintf(vlog, "We claim version: %s", verstring);
1928 strcat(verstring, "\n");
1930 logevent("Using SSH protocol version 1");
1931 sk_write(ssh->s, verstring, strlen(verstring));
1932 ssh->protocol = ssh1_protocol;
1934 ssh->s_rdpkt = ssh1_rdpkt;
1936 ssh->state = SSH_STATE_BEFORE_SIZE;
1943 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1945 crBegin(ssh->ssh_gotdata_crstate);
1948 * To begin with, feed the characters one by one to the
1949 * protocol initialisation / selection function do_ssh_init().
1950 * When that returns 0, we're done with the initial greeting
1951 * exchange and can move on to packet discipline.
1954 int ret; /* need not be kept across crReturn */
1956 crReturnV; /* more data please */
1957 ret = do_ssh_init(ssh, *data);
1965 * We emerge from that loop when the initial negotiation is
1966 * over and we have selected an s_rdpkt function. Now pass
1967 * everything to s_rdpkt, and then pass the resulting packets
1968 * to the proper protocol handler.
1973 while (datalen > 0) {
1974 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1975 if (ssh->state == SSH_STATE_CLOSED) {
1978 ssh->protocol(ssh, NULL, 0, 1);
1979 if (ssh->state == SSH_STATE_CLOSED) {
1989 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1992 Ssh ssh = (Ssh) plug;
1993 ssh->state = SSH_STATE_CLOSED;
1999 /* A socket error has occurred. */
2000 logevent(error_msg);
2001 connection_fatal(ssh->frontend, error_msg);
2003 /* Otherwise, the remote side closed the connection normally. */
2008 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2010 Ssh ssh = (Ssh) plug;
2011 ssh_gotdata(ssh, data, len);
2012 if (ssh->state == SSH_STATE_CLOSED) {
2022 static void ssh_sent(Plug plug, int bufsize)
2024 Ssh ssh = (Ssh) plug;
2026 * If the send backlog on the SSH socket itself clears, we
2027 * should unthrottle the whole world if it was throttled.
2029 if (bufsize < SSH_MAX_BACKLOG)
2030 ssh_throttle_all(ssh, 0, bufsize);
2034 * Connect to specified host and port.
2035 * Returns an error message, or NULL on success.
2036 * Also places the canonical host name into `realhost'. It must be
2037 * freed by the caller.
2039 static char *connect_to_host(Ssh ssh, char *host, int port,
2040 char **realhost, int nodelay)
2042 static const struct plug_function_table fn_table = {
2052 ssh->savedhost = smalloc(1 + strlen(host));
2053 if (!ssh->savedhost)
2054 fatalbox("Out of memory");
2055 strcpy(ssh->savedhost, host);
2058 port = 22; /* default ssh port */
2059 ssh->savedport = port;
2064 logeventf(ssh, "Looking up host \"%s\"", host);
2065 addr = name_lookup(host, port, realhost);
2066 if ((err = sk_addr_error(addr)))
2074 sk_getaddr(addr, addrbuf, 100);
2075 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2077 ssh->fn = &fn_table;
2078 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2079 if ((err = sk_socket_error(ssh->s))) {
2088 * Throttle or unthrottle the SSH connection.
2090 static void ssh1_throttle(Ssh ssh, int adjust)
2092 int old_count = ssh->v1_throttle_count;
2093 ssh->v1_throttle_count += adjust;
2094 assert(ssh->v1_throttle_count >= 0);
2095 if (ssh->v1_throttle_count && !old_count) {
2096 sk_set_frozen(ssh->s, 1);
2097 } else if (!ssh->v1_throttle_count && old_count) {
2098 sk_set_frozen(ssh->s, 0);
2103 * Throttle or unthrottle _all_ local data streams (for when sends
2104 * on the SSH connection itself back up).
2106 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2109 struct ssh_channel *c;
2111 if (enable == ssh->throttled_all)
2113 ssh->throttled_all = enable;
2114 ssh->overall_bufsize = bufsize;
2117 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2119 case CHAN_MAINSESSION:
2121 * This is treated separately, outside the switch.
2125 x11_override_throttle(c->u.x11.s, enable);
2128 /* Agent channels require no buffer management. */
2131 pfd_override_throttle(c->u.x11.s, enable);
2138 * Username and password input, abstracted off into routines
2139 * reusable in several places - even between SSH1 and SSH2.
2142 /* Set up a username or password input loop on a given buffer. */
2143 void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2145 ssh->userpass_input_buffer = buffer;
2146 ssh->userpass_input_buflen = buflen;
2147 ssh->userpass_input_bufpos = 0;
2148 ssh->userpass_input_echo = echo;
2152 * Process some terminal data in the course of username/password
2153 * input. Returns >0 for success (line of input returned in
2154 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2155 * for inconclusive (keep waiting for more input please).
2157 int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2162 switch (c = *in++) {
2165 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2166 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2171 if (ssh->userpass_input_bufpos > 0) {
2172 if (ssh->userpass_input_echo)
2173 c_write_str(ssh, "\b \b");
2174 ssh->userpass_input_bufpos--;
2179 while (ssh->userpass_input_bufpos > 0) {
2180 if (ssh->userpass_input_echo)
2181 c_write_str(ssh, "\b \b");
2182 ssh->userpass_input_bufpos--;
2190 if (((c >= ' ' && c <= '~') ||
2191 ((unsigned char) c >= 160))
2192 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2193 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2194 if (ssh->userpass_input_echo)
2195 c_write(ssh, &c, 1);
2204 * Handle the key exchange and user authentication phases.
2206 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2209 unsigned char cookie[8];
2210 struct RSAKey servkey, hostkey;
2211 struct MD5Context md5c;
2212 struct do_ssh1_login_state {
2214 unsigned char *rsabuf, *keystr1, *keystr2;
2215 unsigned long supported_ciphers_mask, supported_auths_mask;
2216 int tried_publickey, tried_agent;
2217 int tis_auth_refused, ccard_auth_refused;
2218 unsigned char session_id[16];
2221 void *publickey_blob;
2222 int publickey_bloblen;
2228 unsigned char request[5], *response, *p;
2237 crState(do_ssh1_login_state);
2239 crBegin(ssh->do_ssh1_login_crstate);
2244 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2245 bombout((ssh,"Public key packet not received"));
2249 logevent("Received public keys");
2251 memcpy(cookie, ssh->pktin.body, 8);
2253 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2254 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2257 * Log the host key fingerprint.
2261 logevent("Host key fingerprint is:");
2262 strcpy(logmsg, " ");
2263 hostkey.comment = NULL;
2264 rsa_fingerprint(logmsg + strlen(logmsg),
2265 sizeof(logmsg) - strlen(logmsg), &hostkey);
2269 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2270 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2271 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2273 ssh->v1_local_protoflags =
2274 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2275 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2278 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2279 MD5Update(&md5c, s->keystr1, servkey.bytes);
2280 MD5Update(&md5c, ssh->pktin.body, 8);
2281 MD5Final(s->session_id, &md5c);
2283 for (i = 0; i < 32; i++)
2284 ssh->session_key[i] = random_byte();
2286 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2288 s->rsabuf = smalloc(s->len);
2290 fatalbox("Out of memory");
2293 * Verify the host key.
2297 * First format the key into a string.
2299 int len = rsastr_len(&hostkey);
2300 char fingerprint[100];
2301 char *keystr = smalloc(len);
2303 fatalbox("Out of memory");
2304 rsastr_fmt(keystr, &hostkey);
2305 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2306 verify_ssh_host_key(ssh->frontend,
2307 ssh->savedhost, ssh->savedport, "rsa", keystr,
2312 for (i = 0; i < 32; i++) {
2313 s->rsabuf[i] = ssh->session_key[i];
2315 s->rsabuf[i] ^= s->session_id[i];
2318 if (hostkey.bytes > servkey.bytes) {
2319 rsaencrypt(s->rsabuf, 32, &servkey);
2320 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2322 rsaencrypt(s->rsabuf, 32, &hostkey);
2323 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2326 logevent("Encrypted session key");
2329 int cipher_chosen = 0, warn = 0;
2330 char *cipher_string = NULL;
2332 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2333 int next_cipher = cfg.ssh_cipherlist[i];
2334 if (next_cipher == CIPHER_WARN) {
2335 /* If/when we choose a cipher, warn about it */
2337 } else if (next_cipher == CIPHER_AES) {
2338 /* XXX Probably don't need to mention this. */
2339 logevent("AES not supported in SSH1, skipping");
2341 switch (next_cipher) {
2342 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2343 cipher_string = "3DES"; break;
2344 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2345 cipher_string = "Blowfish"; break;
2346 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2347 cipher_string = "single-DES"; break;
2349 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2353 if (!cipher_chosen) {
2354 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2355 bombout((ssh,"Server violates SSH 1 protocol by not "
2356 "supporting 3DES encryption"));
2358 /* shouldn't happen */
2359 bombout((ssh,"No supported ciphers found"));
2363 /* Warn about chosen cipher if necessary. */
2365 askcipher(ssh->frontend, cipher_string, 0);
2368 switch (s->cipher_type) {
2369 case SSH_CIPHER_3DES:
2370 logevent("Using 3DES encryption");
2372 case SSH_CIPHER_DES:
2373 logevent("Using single-DES encryption");
2375 case SSH_CIPHER_BLOWFISH:
2376 logevent("Using Blowfish encryption");
2380 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2381 PKT_CHAR, s->cipher_type,
2382 PKT_DATA, cookie, 8,
2383 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2384 PKT_DATA, s->rsabuf, s->len,
2385 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2387 logevent("Trying to enable encryption...");
2391 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2392 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2394 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2395 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2396 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2398 ssh->crcda_ctx = crcda_make_context();
2399 logevent("Installing CRC compensation attack detector");
2403 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2404 bombout((ssh,"Encryption not successfully enabled"));
2408 logevent("Successfully started encryption");
2412 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2413 if (ssh_get_line && !ssh_getline_pw_only) {
2414 if (!ssh_get_line("login as: ",
2415 s->username, sizeof(s->username), FALSE)) {
2417 * get_line failed to get a username.
2420 logevent("No username provided. Abandoning session.");
2421 ssh->state = SSH_STATE_CLOSED;
2425 int ret; /* need not be kept over crReturn */
2426 c_write_str(ssh, "login as: ");
2429 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2431 crWaitUntil(!ispkt);
2432 ret = process_userpass_input(ssh, in, inlen);
2436 c_write_str(ssh, "\r\n");
2439 strncpy(s->username, cfg.username, sizeof(s->username));
2440 s->username[sizeof(s->username)-1] = '\0';
2443 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2445 char userlog[22 + sizeof(s->username)];
2446 sprintf(userlog, "Sent username \"%s\"", s->username);
2448 if (flags & FLAG_INTERACTIVE &&
2449 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2450 strcat(userlog, "\r\n");
2451 c_write_str(ssh, userlog);
2458 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2459 /* We must not attempt PK auth. Pretend we've already tried it. */
2460 s->tried_publickey = s->tried_agent = 1;
2462 s->tried_publickey = s->tried_agent = 0;
2464 s->tis_auth_refused = s->ccard_auth_refused = 0;
2465 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2467 if (!rsakey_pubblob(cfg.keyfile,
2468 &s->publickey_blob, &s->publickey_bloblen))
2469 s->publickey_blob = NULL;
2471 s->publickey_blob = NULL;
2473 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2474 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2476 if (agent_exists() && !s->tried_agent) {
2478 * Attempt RSA authentication using Pageant.
2484 logevent("Pageant is running. Requesting keys.");
2486 /* Request the keys held by the agent. */
2487 PUT_32BIT(s->request, 1);
2488 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2489 agent_query(s->request, 5, &r, &s->responselen);
2490 s->response = (unsigned char *) r;
2491 if (s->response && s->responselen >= 5 &&
2492 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2493 s->p = s->response + 5;
2494 s->nkeys = GET_32BIT(s->p);
2498 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2501 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2504 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2507 if (s->publickey_blob &&
2508 !memcmp(s->p, s->publickey_blob,
2509 s->publickey_bloblen)) {
2510 logevent("This key matches configured key file");
2511 s->tried_publickey = 1;
2514 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2515 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2516 s->commentlen = GET_32BIT(s->p);
2519 s->p += s->commentlen;
2520 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2521 PKT_BIGNUM, s->key.modulus, PKT_END);
2523 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2524 logevent("Key refused");
2527 logevent("Received RSA challenge");
2528 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2530 char *agentreq, *q, *ret;
2533 len = 1 + 4; /* message type, bit count */
2534 len += ssh1_bignum_length(s->key.exponent);
2535 len += ssh1_bignum_length(s->key.modulus);
2536 len += ssh1_bignum_length(s->challenge);
2537 len += 16; /* session id */
2538 len += 4; /* response format */
2539 agentreq = smalloc(4 + len);
2540 PUT_32BIT(agentreq, len);
2542 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2543 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2545 q += ssh1_write_bignum(q, s->key.exponent);
2546 q += ssh1_write_bignum(q, s->key.modulus);
2547 q += ssh1_write_bignum(q, s->challenge);
2548 memcpy(q, s->session_id, 16);
2550 PUT_32BIT(q, 1); /* response format */
2551 agent_query(agentreq, len + 4, &vret, &retlen);
2555 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2556 logevent("Sending Pageant's response");
2557 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2558 PKT_DATA, ret + 5, 16,
2562 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2564 ("Pageant's response accepted");
2565 if (flags & FLAG_VERBOSE) {
2566 c_write_str(ssh, "Authenticated using"
2568 c_write(ssh, s->commentp,
2570 c_write_str(ssh, "\" from agent\r\n");
2575 ("Pageant's response not accepted");
2578 ("Pageant failed to answer challenge");
2582 logevent("No reply received from Pageant");
2585 freebn(s->key.exponent);
2586 freebn(s->key.modulus);
2587 freebn(s->challenge);
2595 if (*cfg.keyfile && !s->tried_publickey)
2596 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2598 if (cfg.try_tis_auth &&
2599 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2600 !s->tis_auth_refused) {
2601 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2602 logevent("Requested TIS authentication");
2603 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2605 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2606 logevent("TIS authentication declined");
2607 if (flags & FLAG_INTERACTIVE)
2608 c_write_str(ssh, "TIS authentication refused.\r\n");
2609 s->tis_auth_refused = 1;
2612 int challengelen = GET_32BIT(ssh->pktin.body);
2613 logevent("Received TIS challenge");
2614 if (challengelen > sizeof(s->prompt) - 1)
2615 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2616 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2617 /* Prompt heuristic comes from OpenSSH */
2618 strncpy(s->prompt + challengelen,
2619 memchr(s->prompt, '\n', challengelen) ?
2620 "": "\r\nResponse: ",
2621 (sizeof s->prompt) - challengelen);
2622 s->prompt[(sizeof s->prompt) - 1] = '\0';
2625 if (cfg.try_tis_auth &&
2626 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2627 !s->ccard_auth_refused) {
2628 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2629 logevent("Requested CryptoCard authentication");
2630 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2632 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2633 logevent("CryptoCard authentication declined");
2634 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2635 s->ccard_auth_refused = 1;
2638 int challengelen = GET_32BIT(ssh->pktin.body);
2639 logevent("Received CryptoCard challenge");
2640 if (challengelen > sizeof(s->prompt) - 1)
2641 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2642 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2643 strncpy(s->prompt + challengelen,
2644 memchr(s->prompt, '\n', challengelen) ?
2645 "" : "\r\nResponse: ",
2646 sizeof(s->prompt) - challengelen);
2647 s->prompt[sizeof(s->prompt) - 1] = '\0';
2650 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2651 sprintf(s->prompt, "%.90s@%.90s's password: ",
2652 s->username, ssh->savedhost);
2654 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2655 char *comment = NULL;
2658 if (flags & FLAG_VERBOSE)
2659 c_write_str(ssh, "Trying public key authentication.\r\n");
2660 logeventf(ssh, "Trying public key \"%s\"", cfg.keyfile);
2661 type = key_type(cfg.keyfile);
2662 if (type != SSH_KEYTYPE_SSH1) {
2663 sprintf(msgbuf, "Key is of wrong type (%s)",
2664 key_type_to_str(type));
2666 c_write_str(ssh, msgbuf);
2667 c_write_str(ssh, "\r\n");
2668 s->tried_publickey = 1;
2671 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2672 if (flags & FLAG_VERBOSE)
2673 c_write_str(ssh, "No passphrase required.\r\n");
2676 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2681 * Show password prompt, having first obtained it via a TIS
2682 * or CryptoCard exchange if we're doing TIS or CryptoCard
2686 if (!ssh_get_line(s->prompt, s->password,
2687 sizeof(s->password), TRUE)) {
2689 * get_line failed to get a password (for example
2690 * because one was supplied on the command line
2691 * which has already failed to work). Terminate.
2693 send_packet(ssh, SSH1_MSG_DISCONNECT,
2694 PKT_STR, "No more passwords available to try",
2696 logevent("Unable to authenticate");
2697 connection_fatal(ssh->frontend, "Unable to authenticate");
2698 ssh->state = SSH_STATE_CLOSED;
2702 /* Prompt may have come from server. We've munged it a bit, so
2703 * we know it to be zero-terminated at least once. */
2704 int ret; /* need not be saved over crReturn */
2705 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2708 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2710 crWaitUntil(!ispkt);
2711 ret = process_userpass_input(ssh, in, inlen);
2715 c_write_str(ssh, "\r\n");
2719 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2721 * Try public key authentication with the specified
2724 s->tried_publickey = 1;
2727 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2729 c_write_str(ssh, "Couldn't load private key from ");
2730 c_write_str(ssh, cfg.keyfile);
2731 c_write_str(ssh, ".\r\n");
2732 continue; /* go and try password */
2735 c_write_str(ssh, "Wrong passphrase.\r\n");
2736 s->tried_publickey = 0;
2737 continue; /* try again */
2742 * Send a public key attempt.
2744 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2745 PKT_BIGNUM, s->key.modulus, PKT_END);
2748 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2749 c_write_str(ssh, "Server refused our public key.\r\n");
2750 continue; /* go and try password */
2752 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2753 bombout((ssh,"Bizarre response to offer of public key"));
2759 unsigned char buffer[32];
2760 Bignum challenge, response;
2762 ssh1_read_bignum(ssh->pktin.body, &challenge);
2763 response = rsadecrypt(challenge, &s->key);
2764 freebn(s->key.private_exponent);/* burn the evidence */
2766 for (i = 0; i < 32; i++) {
2767 buffer[i] = bignum_byte(response, 31 - i);
2771 MD5Update(&md5c, buffer, 32);
2772 MD5Update(&md5c, s->session_id, 16);
2773 MD5Final(buffer, &md5c);
2775 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2776 PKT_DATA, buffer, 16, PKT_END);
2783 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2784 if (flags & FLAG_VERBOSE)
2785 c_write_str(ssh, "Failed to authenticate with"
2786 " our public key.\r\n");
2787 continue; /* go and try password */
2788 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2789 bombout((ssh,"Bizarre response to RSA authentication response"));
2793 break; /* we're through! */
2795 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2797 * Defence against traffic analysis: we send a
2798 * whole bunch of packets containing strings of
2799 * different lengths. One of these strings is the
2800 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2801 * The others are all random data in
2802 * SSH1_MSG_IGNORE packets. This way a passive
2803 * listener can't tell which is the password, and
2804 * hence can't deduce the password length.
2806 * Anybody with a password length greater than 16
2807 * bytes is going to have enough entropy in their
2808 * password that a listener won't find it _that_
2809 * much help to know how long it is. So what we'll
2812 * - if password length < 16, we send 15 packets
2813 * containing string lengths 1 through 15
2815 * - otherwise, we let N be the nearest multiple
2816 * of 8 below the password length, and send 8
2817 * packets containing string lengths N through
2818 * N+7. This won't obscure the order of
2819 * magnitude of the password length, but it will
2820 * introduce a bit of extra uncertainty.
2822 * A few servers (the old 1.2.18 through 1.2.22)
2823 * can't deal with SSH1_MSG_IGNORE. For these
2824 * servers, we need an alternative defence. We make
2825 * use of the fact that the password is interpreted
2826 * as a C string: so we can append a NUL, then some
2829 * One server (a Cisco one) can deal with neither
2830 * SSH1_MSG_IGNORE _nor_ a padded password string.
2831 * For this server we are left with no defences
2832 * against password length sniffing.
2834 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2836 * The server can deal with SSH1_MSG_IGNORE, so
2837 * we can use the primary defence.
2839 int bottom, top, pwlen, i;
2842 pwlen = strlen(s->password);
2844 bottom = 0; /* zero length passwords are OK! :-) */
2847 bottom = pwlen & ~7;
2851 assert(pwlen >= bottom && pwlen <= top);
2853 randomstr = smalloc(top + 1);
2855 for (i = bottom; i <= top; i++) {
2857 defer_packet(ssh, s->pwpkt_type,
2858 PKT_STR, s->password, PKT_END);
2860 for (j = 0; j < i; j++) {
2862 randomstr[j] = random_byte();
2863 } while (randomstr[j] == '\0');
2865 randomstr[i] = '\0';
2866 defer_packet(ssh, SSH1_MSG_IGNORE,
2867 PKT_STR, randomstr, PKT_END);
2870 logevent("Sending password with camouflage packets");
2871 ssh_pkt_defersend(ssh);
2873 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2875 * The server can't deal with SSH1_MSG_IGNORE
2876 * but can deal with padded passwords, so we
2877 * can use the secondary defence.
2883 len = strlen(s->password);
2884 if (len < sizeof(string)) {
2886 strcpy(string, s->password);
2887 len++; /* cover the zero byte */
2888 while (len < sizeof(string)) {
2889 string[len++] = (char) random_byte();
2894 logevent("Sending length-padded password");
2895 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2896 PKT_DATA, ss, len, PKT_END);
2899 * The server has _both_
2900 * BUG_CHOKES_ON_SSH1_IGNORE and
2901 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2902 * therefore nothing we can do.
2905 len = strlen(s->password);
2906 logevent("Sending unpadded password");
2907 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2908 PKT_DATA, s->password, len, PKT_END);
2911 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2914 logevent("Sent password");
2915 memset(s->password, 0, strlen(s->password));
2917 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2918 if (flags & FLAG_VERBOSE)
2919 c_write_str(ssh, "Access denied\r\n");
2920 logevent("Authentication refused");
2921 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2922 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
2927 logevent("Authentication successful");
2932 void sshfwd_close(struct ssh_channel *c)
2936 if (c && !c->closes) {
2938 * If the channel's remoteid is -1, we have sent
2939 * CHANNEL_OPEN for this channel, but it hasn't even been
2940 * acknowledged by the server. So we must set a close flag
2941 * on it now, and then when the server acks the channel
2942 * open, we can close it then.
2944 if (((int)c->remoteid) != -1) {
2945 if (ssh->version == 1) {
2946 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2949 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2950 ssh2_pkt_adduint32(ssh, c->remoteid);
2954 c->closes = 1; /* sent MSG_CLOSE */
2955 if (c->type == CHAN_X11) {
2957 logevent("Forwarded X11 connection terminated");
2958 } else if (c->type == CHAN_SOCKDATA ||
2959 c->type == CHAN_SOCKDATA_DORMANT) {
2961 logevent("Forwarded port closed");
2966 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2970 if (ssh->version == 1) {
2971 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2972 PKT_INT, c->remoteid,
2973 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2975 * In SSH1 we can return 0 here - implying that forwarded
2976 * connections are never individually throttled - because
2977 * the only circumstance that can cause throttling will be
2978 * the whole SSH connection backing up, in which case
2979 * _everything_ will be throttled as a whole.
2983 ssh2_add_channel_data(c, buf, len);
2984 return ssh2_try_send(c);
2988 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2992 if (ssh->version == 1) {
2993 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2994 c->v.v1.throttling = 0;
2995 ssh1_throttle(ssh, -1);
2998 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3002 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3004 crBegin(ssh->ssh1_protocol_crstate);
3008 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3011 if (ssh->state == SSH_STATE_CLOSED)
3014 if (cfg.agentfwd && agent_exists()) {
3015 logevent("Requesting agent forwarding");
3016 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3020 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3021 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3022 bombout((ssh,"Protocol confusion"));
3024 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3025 logevent("Agent forwarding refused");
3027 logevent("Agent forwarding enabled");
3028 ssh->agentfwd_enabled = TRUE;
3032 if (cfg.x11_forward) {
3033 char proto[20], data[64];
3034 logevent("Requesting X11 forwarding");
3035 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3036 data, sizeof(data));
3037 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3038 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3039 PKT_STR, proto, PKT_STR, data,
3040 PKT_INT, 0, PKT_END);
3042 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3043 PKT_STR, proto, PKT_STR, data, PKT_END);
3048 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3049 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3050 bombout((ssh,"Protocol confusion"));
3052 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3053 logevent("X11 forwarding refused");
3055 logevent("X11 forwarding enabled");
3056 ssh->X11_fwd_enabled = TRUE;
3063 int sport,dport,sserv,dserv;
3064 char sports[256], dports[256], saddr[256], host[256];
3066 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3067 /* Add port forwardings. */
3068 ssh->portfwd_strptr = cfg.portfwd;
3069 while (*ssh->portfwd_strptr) {
3070 type = *ssh->portfwd_strptr++;
3073 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
3074 if (*ssh->portfwd_strptr == ':') {
3076 * We've seen a colon in the middle of the
3077 * source port number. This means that
3078 * everything we've seen until now is the
3079 * source _address_, so we'll move it into
3080 * saddr and start sports from the beginning
3083 ssh->portfwd_strptr++;
3085 strcpy(saddr, sports);
3088 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
3091 if (*ssh->portfwd_strptr == '\t')
3092 ssh->portfwd_strptr++;
3094 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
3095 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
3098 if (*ssh->portfwd_strptr == ':')
3099 ssh->portfwd_strptr++;
3101 while (*ssh->portfwd_strptr) {
3102 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
3105 ssh->portfwd_strptr++;
3106 dport = atoi(dports);
3110 dport = net_service_lookup(dports);
3112 logeventf(ssh, "Service lookup failed for"
3113 " destination port \"%s\"", dports);
3116 sport = atoi(sports);
3120 sport = net_service_lookup(sports);
3122 logeventf(ssh, "Service lookup failed for source"
3123 " port \"%s\"", sports);
3126 if (sport && dport) {
3128 pfd_addforward(host, dport, *saddr ? saddr : NULL,
3130 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
3131 " forwarding to %s:%.*s%.*s%d%.*s",
3132 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
3133 (int)(*saddr?1:0), ":",
3134 (int)(sserv ? strlen(sports) : 0), sports,
3135 sserv, "(", sport, sserv, ")",
3137 (int)(dserv ? strlen(dports) : 0), dports,
3138 dserv, "(", dport, dserv, ")");
3140 struct ssh_rportfwd *pf;
3141 pf = smalloc(sizeof(*pf));
3142 strcpy(pf->dhost, host);
3146 "SSH1 cannot handle source address spec \"%s:%d\"; ignoring",
3149 if (add234(ssh->rportfwds, pf) != pf) {
3151 "Duplicate remote port forwarding to %s:%d",
3155 logeventf(ssh, "Requesting remote port %.*s%.*s%d%.*s"
3156 " forward to %s:%.*s%.*s%d%.*s",
3157 (int)(sserv ? strlen(sports) : 0), sports,
3158 sserv, "(", sport, sserv, ")",
3160 (int)(dserv ? strlen(dports) : 0), dports,
3161 dserv, "(", dport, dserv, ")");
3162 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3170 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3171 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3172 bombout((ssh,"Protocol confusion"));
3174 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3175 c_write_str(ssh, "Server refused port"
3178 logevent("Remote port forwarding enabled");
3186 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3187 PKT_STR, cfg.termtype,
3188 PKT_INT, ssh->term_height,
3189 PKT_INT, ssh->term_width,
3190 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3191 ssh->state = SSH_STATE_INTERMED;
3195 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3196 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3197 bombout((ssh,"Protocol confusion"));
3199 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3200 c_write_str(ssh, "Server refused to allocate pty\r\n");
3201 ssh->editing = ssh->echoing = 1;
3203 logevent("Allocated pty");
3205 ssh->editing = ssh->echoing = 1;
3208 if (cfg.compression) {
3209 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3213 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3214 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3215 bombout((ssh,"Protocol confusion"));
3217 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3218 c_write_str(ssh, "Server refused to compress\r\n");
3220 logevent("Started compression");
3221 ssh->v1_compressing = TRUE;
3222 ssh->cs_comp_ctx = zlib_compress_init();
3223 logevent("Initialised zlib (RFC1950) compression");
3224 ssh->sc_comp_ctx = zlib_decompress_init();
3225 logevent("Initialised zlib (RFC1950) decompression");
3229 * Start the shell or command.
3231 * Special case: if the first-choice command is an SSH2
3232 * subsystem (hence not usable here) and the second choice
3233 * exists, we fall straight back to that.
3236 char *cmd = cfg.remote_cmd_ptr;
3238 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3239 cmd = cfg.remote_cmd_ptr2;
3240 ssh->fallback_cmd = TRUE;
3243 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3245 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3246 logevent("Started session");
3249 ssh->state = SSH_STATE_SESSION;
3250 if (ssh->size_needed)
3251 ssh_size(ssh, ssh->term_width, ssh->term_height);
3252 if (ssh->eof_needed)
3253 ssh_special(ssh, TS_EOF);
3256 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3258 ssh->channels = newtree234(ssh_channelcmp);
3262 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3263 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3264 long len = GET_32BIT(ssh->pktin.body);
3266 from_backend(ssh->frontend,
3267 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3268 ssh->pktin.body + 4, len);
3269 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3270 ssh->v1_stdout_throttling = 1;
3271 ssh1_throttle(ssh, +1);
3273 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3274 ssh->state = SSH_STATE_CLOSED;
3275 logevent("Received disconnect request");
3277 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3278 /* Remote side is trying to open a channel to talk to our
3279 * X-Server. Give them back a local channel number. */
3280 struct ssh_channel *c;
3282 logevent("Received X11 connect request");
3283 /* Refuse if X11 forwarding is disabled. */
3284 if (!ssh->X11_fwd_enabled) {
3285 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3286 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3287 logevent("Rejected X11 connect request");
3289 c = smalloc(sizeof(struct ssh_channel));
3292 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3293 ssh->x11auth) != NULL) {
3294 logevent("opening X11 forward connection failed");
3296 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3297 PKT_INT, GET_32BIT(ssh->pktin.body),
3301 ("opening X11 forward connection succeeded");
3302 c->remoteid = GET_32BIT(ssh->pktin.body);
3303 c->localid = alloc_channel_id(ssh);
3305 c->v.v1.throttling = 0;
3306 c->type = CHAN_X11; /* identify channel type */
3307 add234(ssh->channels, c);
3308 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3309 PKT_INT, c->remoteid, PKT_INT,
3310 c->localid, PKT_END);
3311 logevent("Opened X11 forward channel");
3314 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3315 /* Remote side is trying to open a channel to talk to our
3316 * agent. Give them back a local channel number. */
3317 struct ssh_channel *c;
3319 /* Refuse if agent forwarding is disabled. */
3320 if (!ssh->agentfwd_enabled) {
3321 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3322 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3324 c = smalloc(sizeof(struct ssh_channel));
3326 c->remoteid = GET_32BIT(ssh->pktin.body);
3327 c->localid = alloc_channel_id(ssh);
3329 c->v.v1.throttling = 0;
3330 c->type = CHAN_AGENT; /* identify channel type */
3331 c->u.a.lensofar = 0;
3332 add234(ssh->channels, c);
3333 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3334 PKT_INT, c->remoteid, PKT_INT, c->localid,
3337 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3338 /* Remote side is trying to open a channel to talk to a
3339 * forwarded port. Give them back a local channel number. */
3340 struct ssh_channel *c;
3341 struct ssh_rportfwd pf;
3343 char host[256], buf[1024];
3345 c = smalloc(sizeof(struct ssh_channel));
3348 hostsize = GET_32BIT(ssh->pktin.body+4);
3349 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
3350 if (h+1 < host+sizeof(host))
3355 port = GET_32BIT(p);
3357 strcpy(pf.dhost, host);
3360 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3361 sprintf(buf, "Rejected remote port open request for %s:%d",
3364 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3365 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3367 sprintf(buf, "Received remote port open request for %s:%d",
3370 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3373 sprintf(buf, "Port open failed: %s", e);
3376 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3377 PKT_INT, GET_32BIT(ssh->pktin.body),
3380 c->remoteid = GET_32BIT(ssh->pktin.body);
3381 c->localid = alloc_channel_id(ssh);
3383 c->v.v1.throttling = 0;
3384 c->type = CHAN_SOCKDATA; /* identify channel type */
3385 add234(ssh->channels, c);
3386 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3387 PKT_INT, c->remoteid, PKT_INT,
3388 c->localid, PKT_END);
3389 logevent("Forwarded port opened successfully");
3393 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3394 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3395 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3396 struct ssh_channel *c;
3398 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3399 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3400 c->remoteid = localid;
3401 c->type = CHAN_SOCKDATA;
3402 c->v.v1.throttling = 0;
3403 pfd_confirm(c->u.pfd.s);
3406 if (c && c->closes) {
3408 * We have a pending close on this channel,
3409 * which we decided on before the server acked
3410 * the channel open. So now we know the
3411 * remoteid, we can close it again.
3413 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3414 PKT_INT, c->remoteid, PKT_END);
3417 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3418 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3419 struct ssh_channel *c;
3421 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3422 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3423 logevent("Forwarded connection refused by server");
3424 pfd_close(c->u.pfd.s);
3425 del234(ssh->channels, c);
3429 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3430 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3431 /* Remote side closes a channel. */
3432 unsigned i = GET_32BIT(ssh->pktin.body);
3433 struct ssh_channel *c;
3434 c = find234(ssh->channels, &i, ssh_channelfind);
3435 if (c && ((int)c->remoteid) != -1) {
3438 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3440 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3441 logevent("Forwarded X11 connection terminated");
3442 assert(c->u.x11.s != NULL);
3443 x11_close(c->u.x11.s);
3446 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3447 logevent("Forwarded port closed");
3448 assert(c->u.pfd.s != NULL);
3449 pfd_close(c->u.pfd.s);
3453 c->closes |= (closetype << 2); /* seen this message */
3454 if (!(c->closes & closetype)) {
3455 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3457 c->closes |= closetype; /* sent it too */
3460 if (c->closes == 15) {
3461 del234(ssh->channels, c);
3465 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3466 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3467 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3470 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3471 /* Data sent down one of our channels. */
3472 int i = GET_32BIT(ssh->pktin.body);
3473 int len = GET_32BIT(ssh->pktin.body + 4);
3474 unsigned char *p = ssh->pktin.body + 8;
3475 struct ssh_channel *c;
3476 c = find234(ssh->channels, &i, ssh_channelfind);
3481 bufsize = x11_send(c->u.x11.s, p, len);
3484 bufsize = pfd_send(c->u.pfd.s, p, len);
3487 /* Data for an agent message. Buffer it. */
3489 if (c->u.a.lensofar < 4) {
3490 int l = min(4 - c->u.a.lensofar, len);
3491 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3495 c->u.a.lensofar += l;
3497 if (c->u.a.lensofar == 4) {
3499 4 + GET_32BIT(c->u.a.msglen);
3500 c->u.a.message = smalloc(c->u.a.totallen);
3501 memcpy(c->u.a.message, c->u.a.msglen, 4);
3503 if (c->u.a.lensofar >= 4 && len > 0) {
3505 min(c->u.a.totallen - c->u.a.lensofar,
3507 memcpy(c->u.a.message + c->u.a.lensofar, p,
3511 c->u.a.lensofar += l;
3513 if (c->u.a.lensofar == c->u.a.totallen) {
3514 void *reply, *sentreply;
3516 agent_query(c->u.a.message,
3517 c->u.a.totallen, &reply,
3522 /* Fake SSH_AGENT_FAILURE. */
3523 sentreply = "\0\0\0\1\5";
3526 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3527 PKT_INT, c->remoteid,
3529 PKT_DATA, sentreply, replylen,
3533 sfree(c->u.a.message);
3534 c->u.a.lensofar = 0;
3537 bufsize = 0; /* agent channels never back up */
3540 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3541 c->v.v1.throttling = 1;
3542 ssh1_throttle(ssh, +1);
3545 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3546 /* may be from EXEC_SHELL on some servers */
3547 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3548 /* may be from EXEC_SHELL on some servers
3549 * if no pty is available or in other odd cases. Ignore */
3550 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3552 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3553 sprintf(buf, "Server sent command exit status %d",
3556 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3558 * In case `helpful' firewalls or proxies tack
3559 * extra human-readable text on the end of the
3560 * session which we might mistake for another
3561 * encrypted packet, we close the session once
3562 * we've sent EXIT_CONFIRMATION.
3564 ssh->state = SSH_STATE_CLOSED;
3567 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3572 int len = min(inlen, 512);
3573 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3574 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3585 * Utility routine for decoding comma-separated strings in KEXINIT.
3587 static int in_commasep_string(char *needle, char *haystack, int haylen)
3590 if (!needle || !haystack) /* protect against null pointers */
3592 needlen = strlen(needle);
3595 * Is it at the start of the string?
3597 if (haylen >= needlen && /* haystack is long enough */
3598 !memcmp(needle, haystack, needlen) && /* initial match */
3599 (haylen == needlen || haystack[needlen] == ',')
3600 /* either , or EOS follows */
3604 * If not, search for the next comma and resume after that.
3605 * If no comma found, terminate.
3607 while (haylen > 0 && *haystack != ',')
3608 haylen--, haystack++;
3611 haylen--, haystack++; /* skip over comma itself */
3616 * SSH2 key creation method.
3618 static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
3622 /* First 20 bytes. */
3624 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3626 SHA_Bytes(&s, H, 20);
3627 SHA_Bytes(&s, &chr, 1);
3628 SHA_Bytes(&s, sessid, 20);
3629 SHA_Final(&s, keyspace);
3630 /* Next 20 bytes. */
3632 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3634 SHA_Bytes(&s, H, 20);
3635 SHA_Bytes(&s, keyspace, 20);
3636 SHA_Final(&s, keyspace + 20);
3640 * Handle the SSH2 transport layer.
3642 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3644 struct do_ssh2_transport_state {
3645 int nbits, pbits, warn;
3646 Bignum p, g, e, f, K;
3647 int kex_init_value, kex_reply_value;
3648 const struct ssh_mac **maclist;
3650 const struct ssh2_cipher *cscipher_tobe;
3651 const struct ssh2_cipher *sccipher_tobe;
3652 const struct ssh_mac *csmac_tobe;
3653 const struct ssh_mac *scmac_tobe;
3654 const struct ssh_compress *cscomp_tobe;
3655 const struct ssh_compress *sccomp_tobe;
3656 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3657 int hostkeylen, siglen;
3658 void *hkey; /* actual host key */
3659 unsigned char exchange_hash[20];
3660 int n_preferred_ciphers;
3661 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3662 const struct ssh_compress *preferred_comp;
3665 crState(do_ssh2_transport_state);
3667 crBegin(ssh->do_ssh2_transport_crstate);
3669 s->cscipher_tobe = s->sccipher_tobe = NULL;
3670 s->csmac_tobe = s->scmac_tobe = NULL;
3671 s->cscomp_tobe = s->sccomp_tobe = NULL;
3679 * Set up the preferred ciphers. (NULL => warn below here)
3681 s->n_preferred_ciphers = 0;
3682 for (i = 0; i < CIPHER_MAX; i++) {
3683 switch (cfg.ssh_cipherlist[i]) {
3684 case CIPHER_BLOWFISH:
3685 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3688 if (cfg.ssh2_des_cbc) {
3689 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3693 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3696 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3699 /* Flag for later. Don't bother if it's the last in
3701 if (i < CIPHER_MAX - 1) {
3702 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3710 * Set up preferred compression.
3712 if (cfg.compression)
3713 s->preferred_comp = &ssh_zlib;
3715 s->preferred_comp = &ssh_comp_none;
3718 * Be prepared to work around the buggy MAC problem.
3720 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3721 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3723 s->maclist = macs, s->nmacs = lenof(macs);
3727 int i, j, cipherstr_started;
3730 * Construct and send our key exchange packet.
3732 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3733 for (i = 0; i < 16; i++)
3734 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3735 /* List key exchange algorithms. */
3736 ssh2_pkt_addstring_start(ssh);
3737 for (i = 0; i < lenof(kex_algs); i++) {
3738 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3739 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3741 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3742 if (i < lenof(kex_algs) - 1)
3743 ssh2_pkt_addstring_str(ssh, ",");
3745 /* List server host key algorithms. */
3746 ssh2_pkt_addstring_start(ssh);
3747 for (i = 0; i < lenof(hostkey_algs); i++) {
3748 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3749 if (i < lenof(hostkey_algs) - 1)
3750 ssh2_pkt_addstring_str(ssh, ",");
3752 /* List client->server encryption algorithms. */
3753 ssh2_pkt_addstring_start(ssh);
3754 cipherstr_started = 0;
3755 for (i = 0; i < s->n_preferred_ciphers; i++) {
3756 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3757 if (!c) continue; /* warning flag */
3758 for (j = 0; j < c->nciphers; j++) {
3759 if (cipherstr_started)
3760 ssh2_pkt_addstring_str(ssh, ",");
3761 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3762 cipherstr_started = 1;
3765 /* List server->client encryption algorithms. */
3766 ssh2_pkt_addstring_start(ssh);
3767 cipherstr_started = 0;
3768 for (i = 0; i < s->n_preferred_ciphers; i++) {
3769 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3770 if (!c) continue; /* warning flag */
3771 for (j = 0; j < c->nciphers; j++) {
3772 if (cipherstr_started)
3773 ssh2_pkt_addstring_str(ssh, ",");
3774 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3775 cipherstr_started = 1;
3778 /* List client->server MAC algorithms. */
3779 ssh2_pkt_addstring_start(ssh);
3780 for (i = 0; i < s->nmacs; i++) {
3781 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3782 if (i < s->nmacs - 1)
3783 ssh2_pkt_addstring_str(ssh, ",");
3785 /* List server->client MAC algorithms. */
3786 ssh2_pkt_addstring_start(ssh);
3787 for (i = 0; i < s->nmacs; i++) {
3788 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3789 if (i < s->nmacs - 1)
3790 ssh2_pkt_addstring_str(ssh, ",");
3792 /* List client->server compression algorithms. */
3793 ssh2_pkt_addstring_start(ssh);
3794 for (i = 0; i < lenof(compressions) + 1; i++) {
3795 const struct ssh_compress *c =
3796 i == 0 ? s->preferred_comp : compressions[i - 1];
3797 ssh2_pkt_addstring_str(ssh, c->name);
3798 if (i < lenof(compressions))
3799 ssh2_pkt_addstring_str(ssh, ",");
3801 /* List server->client compression algorithms. */
3802 ssh2_pkt_addstring_start(ssh);
3803 for (i = 0; i < lenof(compressions) + 1; i++) {
3804 const struct ssh_compress *c =
3805 i == 0 ? s->preferred_comp : compressions[i - 1];
3806 ssh2_pkt_addstring_str(ssh, c->name);
3807 if (i < lenof(compressions))
3808 ssh2_pkt_addstring_str(ssh, ",");
3810 /* List client->server languages. Empty list. */
3811 ssh2_pkt_addstring_start(ssh);
3812 /* List server->client languages. Empty list. */
3813 ssh2_pkt_addstring_start(ssh);
3814 /* First KEX packet does _not_ follow, because we're not that brave. */
3815 ssh2_pkt_addbool(ssh, FALSE);
3817 ssh2_pkt_adduint32(ssh, 0);
3820 ssh->exhash = ssh->exhashbase;
3821 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3827 if (ssh->pktin.length > 5)
3828 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3831 * Now examine the other side's KEXINIT to see what we're up
3838 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3839 bombout((ssh,"expected key exchange packet from server"));
3843 ssh->hostkey = NULL;
3844 s->cscipher_tobe = NULL;
3845 s->sccipher_tobe = NULL;
3846 s->csmac_tobe = NULL;
3847 s->scmac_tobe = NULL;
3848 s->cscomp_tobe = NULL;
3849 s->sccomp_tobe = NULL;
3850 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3851 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3852 for (i = 0; i < lenof(kex_algs); i++) {
3853 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3854 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3856 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3857 ssh->kex = kex_algs[i];
3861 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3862 for (i = 0; i < lenof(hostkey_algs); i++) {
3863 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3864 ssh->hostkey = hostkey_algs[i];
3868 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3870 for (i = 0; i < s->n_preferred_ciphers; i++) {
3871 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3875 for (j = 0; j < c->nciphers; j++) {
3876 if (in_commasep_string(c->list[j]->name, str, len)) {
3877 s->cscipher_tobe = c->list[j];
3882 if (s->cscipher_tobe) {
3884 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3888 if (!s->cscipher_tobe) {
3889 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)",
3890 str ? str : "(null)"));
3894 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3896 for (i = 0; i < s->n_preferred_ciphers; i++) {
3897 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3901 for (j = 0; j < c->nciphers; j++) {
3902 if (in_commasep_string(c->list[j]->name, str, len)) {
3903 s->sccipher_tobe = c->list[j];
3908 if (s->sccipher_tobe) {
3910 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3914 if (!s->sccipher_tobe) {
3915 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)",
3916 str ? str : "(null)"));
3920 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3921 for (i = 0; i < s->nmacs; i++) {
3922 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3923 s->csmac_tobe = s->maclist[i];
3927 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3928 for (i = 0; i < s->nmacs; i++) {
3929 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3930 s->scmac_tobe = s->maclist[i];
3934 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3935 for (i = 0; i < lenof(compressions) + 1; i++) {
3936 const struct ssh_compress *c =
3937 i == 0 ? s->preferred_comp : compressions[i - 1];
3938 if (in_commasep_string(c->name, str, len)) {
3943 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3944 for (i = 0; i < lenof(compressions) + 1; i++) {
3945 const struct ssh_compress *c =
3946 i == 0 ? s->preferred_comp : compressions[i - 1];
3947 if (in_commasep_string(c->name, str, len)) {
3955 * Work out the number of bits of key we will need from the key
3956 * exchange. We start with the maximum key length of either
3962 csbits = s->cscipher_tobe->keylen;
3963 scbits = s->sccipher_tobe->keylen;
3964 s->nbits = (csbits > scbits ? csbits : scbits);
3966 /* The keys only have 160-bit entropy, since they're based on
3967 * a SHA-1 hash. So cap the key size at 160 bits. */
3972 * If we're doing Diffie-Hellman group exchange, start by
3973 * requesting a group.
3975 if (ssh->kex == &ssh_diffiehellman_gex) {
3976 logevent("Doing Diffie-Hellman group exchange");
3977 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3979 * Work out how big a DH group we will need to allow that
3982 s->pbits = 512 << ((s->nbits - 1) / 64);
3983 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3984 ssh2_pkt_adduint32(ssh, s->pbits);
3988 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3989 bombout((ssh,"expected key exchange group packet from server"));
3992 s->p = ssh2_pkt_getmp(ssh);
3993 s->g = ssh2_pkt_getmp(ssh);
3994 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3995 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3996 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3998 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3999 ssh->kex_ctx = dh_setup_group1();
4000 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
4001 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
4004 logevent("Doing Diffie-Hellman key exchange");
4006 * Now generate and send e for Diffie-Hellman.
4008 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
4009 ssh2_pkt_init(ssh, s->kex_init_value);
4010 ssh2_pkt_addmp(ssh, s->e);
4014 if (ssh->pktin.type != s->kex_reply_value) {
4015 bombout((ssh,"expected key exchange reply packet from server"));
4018 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4019 s->f = ssh2_pkt_getmp(ssh);
4020 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4022 s->K = dh_find_K(ssh->kex_ctx, s->f);
4024 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4025 if (ssh->kex == &ssh_diffiehellman_gex) {
4026 sha_uint32(&ssh->exhash, s->pbits);
4027 sha_mpint(&ssh->exhash, s->p);
4028 sha_mpint(&ssh->exhash, s->g);
4030 sha_mpint(&ssh->exhash, s->e);
4031 sha_mpint(&ssh->exhash, s->f);
4032 sha_mpint(&ssh->exhash, s->K);
4033 SHA_Final(&ssh->exhash, s->exchange_hash);
4035 dh_cleanup(ssh->kex_ctx);
4038 debug(("Exchange hash is:\n"));
4039 dmemdump(s->exchange_hash, 20);
4042 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4044 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4045 s->exchange_hash, 20)) {
4046 bombout((ssh,"Server's host key did not match the signature supplied"));
4051 * Authenticate remote host: verify host key. (We've already
4052 * checked the signature of the exchange hash.)
4054 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4055 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4056 verify_ssh_host_key(ssh->frontend,
4057 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4058 s->keystr, s->fingerprint);
4059 if (s->first_kex) { /* don't bother logging this in rekeys */
4060 logevent("Host key fingerprint is:");
4061 logevent(s->fingerprint);
4063 sfree(s->fingerprint);
4065 ssh->hostkey->freekey(s->hkey);
4068 * Send SSH2_MSG_NEWKEYS.
4070 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4074 * Expect SSH2_MSG_NEWKEYS from server.
4077 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4078 bombout((ssh,"expected new-keys packet from server"));
4083 * Create and initialise session keys.
4085 if (ssh->cs_cipher_ctx)
4086 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4087 ssh->cscipher = s->cscipher_tobe;
4088 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4090 if (ssh->sc_cipher_ctx)
4091 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4092 ssh->sccipher = s->sccipher_tobe;
4093 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4095 if (ssh->cs_mac_ctx)
4096 ssh->csmac->free_context(ssh->cs_mac_ctx);
4097 ssh->csmac = s->csmac_tobe;
4098 ssh->cs_mac_ctx = ssh->csmac->make_context();
4100 if (ssh->sc_mac_ctx)
4101 ssh->scmac->free_context(ssh->sc_mac_ctx);
4102 ssh->scmac = s->scmac_tobe;
4103 ssh->sc_mac_ctx = ssh->scmac->make_context();
4105 if (ssh->cs_comp_ctx)
4106 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4107 ssh->cscomp = s->cscomp_tobe;
4108 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4110 if (ssh->sc_comp_ctx)
4111 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4112 ssh->sccomp = s->sccomp_tobe;
4113 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4116 * Set IVs after keys. Here we use the exchange hash from the
4117 * _first_ key exchange.
4120 unsigned char keyspace[40];
4122 memcpy(ssh->v2_session_id, s->exchange_hash,
4123 sizeof(s->exchange_hash));
4124 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4125 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4126 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4127 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4128 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4129 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4130 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4131 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4132 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4133 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4134 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4135 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4137 logeventf(ssh, "Initialised %.200s client->server encryption",
4138 ssh->cscipher->text_name);
4139 logeventf(ssh, "Initialised %.200s server->client encryption",
4140 ssh->sccipher->text_name);
4141 if (ssh->cscomp->text_name)
4142 logeventf(ssh, "Initialised %s compression",
4143 ssh->cscomp->text_name);
4144 if (ssh->sccomp->text_name)
4145 logeventf(ssh, "Initialised %s decompression",
4146 ssh->sccomp->text_name);
4149 * If this is the first key exchange phase, we must pass the
4150 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4151 * wants to see it but because it will need time to initialise
4152 * itself before it sees an actual packet. In subsequent key
4153 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4154 * it would only confuse the layer above.
4156 if (!s->first_kex) {
4162 * Now we're encrypting. Begin returning 1 to the protocol main
4163 * function so that other things can run on top of the
4164 * transport. If we ever see a KEXINIT, we must go back to the
4167 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4170 logevent("Server initiated key re-exchange");
4171 goto begin_key_exchange;
4177 * Add data to an SSH2 channel output buffer.
4179 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4182 bufchain_add(&c->v.v2.outbuffer, buf, len);
4186 * Attempt to send data on an SSH2 channel.
4188 static int ssh2_try_send(struct ssh_channel *c)
4192 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4195 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4196 if ((unsigned)len > c->v.v2.remwindow)
4197 len = c->v.v2.remwindow;
4198 if ((unsigned)len > c->v.v2.remmaxpkt)
4199 len = c->v.v2.remmaxpkt;
4200 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4201 ssh2_pkt_adduint32(ssh, c->remoteid);
4202 ssh2_pkt_addstring_start(ssh);
4203 ssh2_pkt_addstring_data(ssh, data, len);
4205 bufchain_consume(&c->v.v2.outbuffer, len);
4206 c->v.v2.remwindow -= len;
4210 * After having sent as much data as we can, return the amount
4213 return bufchain_size(&c->v.v2.outbuffer);
4217 * Potentially enlarge the window on an SSH2 channel.
4219 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4224 * Never send WINDOW_ADJUST for a channel that the remote side
4225 * already thinks it's closed; there's no point, since it won't
4226 * be sending any more data anyway.
4231 if (newwin > c->v.v2.locwindow) {
4232 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4233 ssh2_pkt_adduint32(ssh, c->remoteid);
4234 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4236 c->v.v2.locwindow = newwin;
4241 * Handle the SSH2 userauth and connection layers.
4243 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4245 struct do_ssh2_authconn_state {
4247 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4249 AUTH_KEYBOARD_INTERACTIVE
4253 AUTH_TYPE_PUBLICKEY,
4254 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4255 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4257 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4258 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4260 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4261 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4262 int kbd_inter_running;
4264 int num_prompts, curr_prompt, echo;
4269 void *publickey_blob;
4270 int publickey_bloblen;
4271 unsigned char request[5], *response, *p;
4275 char *pkblob, *alg, *commentp;
4276 int pklen, alglen, commentlen;
4277 int siglen, retlen, len;
4278 char *q, *agentreq, *ret;
4281 crState(do_ssh2_authconn_state);
4283 crBegin(ssh->do_ssh2_authconn_crstate);
4286 * Request userauth protocol, and await a response to it.
4288 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4289 ssh2_pkt_addstring(ssh, "ssh-userauth");
4291 crWaitUntilV(ispkt);
4292 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4293 bombout((ssh,"Server refused user authentication protocol"));
4298 * We repeat this whole loop, including the username prompt,
4299 * until we manage a successful authentication. If the user
4300 * types the wrong _password_, they can be sent back to the
4301 * beginning to try another username, if this is configured on.
4302 * (If they specify a username in the config, they are never
4303 * asked, even if they do give a wrong password.)
4305 * I think this best serves the needs of
4307 * - the people who have no configuration, no keys, and just
4308 * want to try repeated (username,password) pairs until they
4309 * type both correctly
4311 * - people who have keys and configuration but occasionally
4312 * need to fall back to passwords
4314 * - people with a key held in Pageant, who might not have
4315 * logged in to a particular machine before; so they want to
4316 * type a username, and then _either_ their key will be
4317 * accepted, _or_ they will type a password. If they mistype
4318 * the username they will want to be able to get back and
4321 s->username[0] = '\0';
4322 s->got_username = FALSE;
4327 if (s->got_username && !cfg.change_username) {
4329 * We got a username last time round this loop, and
4330 * with change_username turned off we don't try to get
4333 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4334 if (ssh_get_line && !ssh_getline_pw_only) {
4335 if (!ssh_get_line("login as: ",
4336 s->username, sizeof(s->username), FALSE)) {
4338 * get_line failed to get a username.
4341 logevent("No username provided. Abandoning session.");
4342 ssh->state = SSH_STATE_CLOSED;
4346 int ret; /* need not be saved across crReturn */
4347 c_write_str(ssh, "login as: ");
4349 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4351 crWaitUntilV(!ispkt);
4352 ret = process_userpass_input(ssh, in, inlen);
4356 c_write_str(ssh, "\r\n");
4358 s->username[strcspn(s->username, "\n\r")] = '\0';
4361 strncpy(s->username, cfg.username, sizeof(s->username));
4362 s->username[sizeof(s->username)-1] = '\0';
4363 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4364 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
4365 c_write_str(ssh, stuff);
4369 s->got_username = TRUE;
4372 * Send an authentication request using method "none": (a)
4373 * just in case it succeeds, and (b) so that we know what
4374 * authentication methods we can usefully try next.
4376 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4378 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4379 ssh2_pkt_addstring(ssh, s->username);
4380 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4381 ssh2_pkt_addstring(ssh, "none"); /* method */
4383 s->type = AUTH_TYPE_NONE;
4385 s->we_are_in = FALSE;
4387 s->tried_pubkey_config = FALSE;
4388 s->tried_agent = FALSE;
4389 s->tried_keyb_inter = FALSE;
4390 s->kbd_inter_running = FALSE;
4391 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4394 logeventf(ssh, "Reading private key file \"%.150s\"", cfg.keyfile);
4395 keytype = key_type(cfg.keyfile);
4396 if (keytype == SSH_KEYTYPE_SSH2) {
4398 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4399 &s->publickey_bloblen);
4402 logeventf(ssh, "Unable to use this key file (%s)",
4403 key_type_to_str(keytype));
4404 msgbuf = dupprintf("Unable to use key file \"%.150s\""
4405 " (%s)\r\n", cfg.keyfile,
4406 key_type_to_str(keytype));
4407 c_write_str(ssh, msgbuf);
4409 s->publickey_blob = NULL;
4412 s->publickey_blob = NULL;
4416 * Wait for the result of the last authentication request.
4419 crWaitUntilV(ispkt);
4420 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4424 * Don't show the banner if we're operating in
4425 * non-verbose non-interactive mode. (It's probably
4426 * a script, which means nobody will read the
4427 * banner _anyway_, and moreover the printing of
4428 * the banner will screw up processing on the
4429 * output of (say) plink.)
4431 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4432 ssh2_pkt_getstring(ssh, &banner, &size);
4434 c_write_untrusted(ssh, banner, size);
4436 crWaitUntilV(ispkt);
4438 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4439 logevent("Access granted");
4440 s->we_are_in = TRUE;
4444 if (s->kbd_inter_running &&
4445 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4447 * This is either a further set-of-prompts packet
4448 * in keyboard-interactive authentication, or it's
4449 * the same one and we came back here with `gotit'
4450 * set. In the former case, we must reset the
4451 * curr_prompt variable.
4455 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4456 bombout((ssh,"Strange packet received during authentication: type %d",
4464 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4465 * we can look at the string in it and know what we can
4466 * helpfully try next.
4468 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4471 ssh2_pkt_getstring(ssh, &methods, &methlen);
4472 s->kbd_inter_running = FALSE;
4473 if (!ssh2_pkt_getbool(ssh)) {
4475 * We have received an unequivocal Access
4476 * Denied. This can translate to a variety of
4479 * - if we'd just tried "none" authentication,
4480 * it's not worth printing anything at all
4482 * - if we'd just tried a public key _offer_,
4483 * the message should be "Server refused our
4484 * key" (or no message at all if the key
4485 * came from Pageant)
4487 * - if we'd just tried anything else, the
4488 * message really should be "Access denied".
4490 * Additionally, if we'd just tried password
4491 * authentication, we should break out of this
4492 * whole loop so as to go back to the username
4495 if (s->type == AUTH_TYPE_NONE) {
4497 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4498 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4499 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4500 c_write_str(ssh, "Server refused our key\r\n");
4501 logevent("Server refused public key");
4502 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4503 /* server declined keyboard-interactive; ignore */
4505 c_write_str(ssh, "Access denied\r\n");
4506 logevent("Access denied");
4507 if (s->type == AUTH_TYPE_PASSWORD) {
4508 s->we_are_in = FALSE;
4513 c_write_str(ssh, "Further authentication required\r\n");
4514 logevent("Further authentication required");
4518 in_commasep_string("publickey", methods, methlen);
4520 in_commasep_string("password", methods, methlen);
4521 s->can_keyb_inter = cfg.try_ki_auth &&
4522 in_commasep_string("keyboard-interactive", methods, methlen);
4526 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4529 * Most password/passphrase prompts will be
4530 * non-echoing, so we set this to 0 by default.
4531 * Exception is that some keyboard-interactive prompts
4532 * can be echoing, in which case we'll set this to 1.
4536 if (!s->method && s->can_pubkey &&
4537 agent_exists() && !s->tried_agent) {
4539 * Attempt public-key authentication using Pageant.
4544 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4545 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4547 s->tried_agent = TRUE;
4549 logevent("Pageant is running. Requesting keys.");
4551 /* Request the keys held by the agent. */
4552 PUT_32BIT(s->request, 1);
4553 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4554 agent_query(s->request, 5, &r, &s->responselen);
4555 s->response = (unsigned char *) r;
4556 if (s->response && s->responselen >= 5 &&
4557 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4558 s->p = s->response + 5;
4559 s->nkeys = GET_32BIT(s->p);
4563 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4566 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4571 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4574 s->pklen = GET_32BIT(s->p);
4576 if (s->publickey_blob &&
4577 s->pklen == s->publickey_bloblen &&
4578 !memcmp(s->p, s->publickey_blob,
4579 s->publickey_bloblen)) {
4580 logevent("This key matches configured key file");
4581 s->tried_pubkey_config = 1;
4585 s->alglen = GET_32BIT(s->pkblob);
4586 s->alg = s->pkblob + 4;
4587 s->commentlen = GET_32BIT(s->p);
4590 s->p += s->commentlen;
4591 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4592 ssh2_pkt_addstring(ssh, s->username);
4593 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4594 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4595 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4596 ssh2_pkt_addstring_start(ssh);
4597 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4598 ssh2_pkt_addstring_start(ssh);
4599 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4602 crWaitUntilV(ispkt);
4603 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4604 logevent("Key refused");
4608 if (flags & FLAG_VERBOSE) {
4609 c_write_str(ssh, "Authenticating with "
4611 c_write(ssh, s->commentp, s->commentlen);
4612 c_write_str(ssh, "\" from agent\r\n");
4616 * Server is willing to accept the key.
4617 * Construct a SIGN_REQUEST.
4619 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4620 ssh2_pkt_addstring(ssh, s->username);
4621 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4622 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4623 ssh2_pkt_addbool(ssh, TRUE);
4624 ssh2_pkt_addstring_start(ssh);
4625 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4626 ssh2_pkt_addstring_start(ssh);
4627 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4629 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4630 s->len = 1; /* message type */
4631 s->len += 4 + s->pklen; /* key blob */
4632 s->len += 4 + s->siglen; /* data to sign */
4633 s->len += 4; /* flags */
4634 s->agentreq = smalloc(4 + s->len);
4635 PUT_32BIT(s->agentreq, s->len);
4636 s->q = s->agentreq + 4;
4637 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4638 PUT_32BIT(s->q, s->pklen);
4640 memcpy(s->q, s->pkblob, s->pklen);
4642 PUT_32BIT(s->q, s->siglen);
4644 /* Now the data to be signed... */
4645 PUT_32BIT(s->q, 20);
4647 memcpy(s->q, ssh->v2_session_id, 20);
4649 memcpy(s->q, ssh->pktout.data + 5,
4650 ssh->pktout.length - 5);
4651 s->q += ssh->pktout.length - 5;
4652 /* And finally the (zero) flags word. */
4654 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4658 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4659 logevent("Sending Pageant's response");
4660 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4662 GET_32BIT(s->ret + 5));
4668 ("Pageant failed to answer challenge");
4678 if (!s->method && s->can_pubkey && s->publickey_blob
4679 && !s->tried_pubkey_config) {
4680 unsigned char *pub_blob;
4681 char *algorithm, *comment;
4684 s->tried_pubkey_config = TRUE;
4686 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4687 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4690 * Try the public key supplied in the configuration.
4692 * First, offer the public blob to see if the server is
4693 * willing to accept it.
4695 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4698 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4699 ssh2_pkt_addstring(ssh, s->username);
4700 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4701 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4702 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4703 ssh2_pkt_addstring(ssh, algorithm);
4704 ssh2_pkt_addstring_start(ssh);
4705 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4707 logevent("Offered public key"); /* FIXME */
4709 crWaitUntilV(ispkt);
4710 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4712 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4713 continue; /* key refused; give up on it */
4716 logevent("Offer of public key accepted");
4718 * Actually attempt a serious authentication using
4721 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4722 sprintf(s->pwprompt,
4723 "Passphrase for key \"%.100s\": ",
4729 c_write_str(ssh, "Authenticating with public key \"");
4730 c_write_str(ssh, comment);
4731 c_write_str(ssh, "\"\r\n");
4732 s->method = AUTH_PUBLICKEY_FILE;
4736 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4737 s->method = AUTH_KEYBOARD_INTERACTIVE;
4738 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4739 s->tried_keyb_inter = TRUE;
4741 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4742 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4744 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4745 ssh2_pkt_addstring(ssh, s->username);
4746 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4747 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4748 ssh2_pkt_addstring(ssh, ""); /* lang */
4749 ssh2_pkt_addstring(ssh, "");
4752 crWaitUntilV(ispkt);
4753 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4754 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4756 logevent("Keyboard-interactive authentication refused");
4757 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4761 s->kbd_inter_running = TRUE;
4765 if (s->kbd_inter_running) {
4766 s->method = AUTH_KEYBOARD_INTERACTIVE;
4767 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4768 s->tried_keyb_inter = TRUE;
4770 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4771 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4773 if (s->curr_prompt == 0) {
4775 * We've got a fresh USERAUTH_INFO_REQUEST.
4776 * Display header data, and start going through
4779 char *name, *inst, *lang;
4780 int name_len, inst_len, lang_len;
4782 ssh2_pkt_getstring(ssh, &name, &name_len);
4783 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4784 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4786 c_write_untrusted(ssh, name, name_len);
4787 c_write_str(ssh, "\r\n");
4790 c_write_untrusted(ssh, inst, inst_len);
4791 c_write_str(ssh, "\r\n");
4793 s->num_prompts = ssh2_pkt_getuint32(ssh);
4797 * If there are prompts remaining in the packet,
4798 * display one and get a response.
4800 if (s->curr_prompt < s->num_prompts) {
4804 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4805 if (prompt_len > 0) {
4806 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4807 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4808 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4811 "<server failed to send prompt>: ");
4813 s->echo = ssh2_pkt_getbool(ssh);
4819 if (!s->method && s->can_passwd) {
4820 s->method = AUTH_PASSWORD;
4821 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4822 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4823 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4830 if (!ssh_get_line(s->pwprompt, s->password,
4831 sizeof(s->password), TRUE)) {
4833 * get_line failed to get a password (for
4834 * example because one was supplied on the
4835 * command line which has already failed to
4838 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4839 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4840 ssh2_pkt_addstring(ssh, "No more passwords available"
4842 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4844 logevent("Unable to authenticate");
4845 connection_fatal(ssh->frontend,
4846 "Unable to authenticate");
4847 ssh->state = SSH_STATE_CLOSED;
4851 int ret; /* need not be saved across crReturn */
4852 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4855 setup_userpass_input(ssh, s->password,
4856 sizeof(s->password), s->echo);
4858 crWaitUntilV(!ispkt);
4859 ret = process_userpass_input(ssh, in, inlen);
4863 c_write_str(ssh, "\r\n");
4867 if (s->method == AUTH_PUBLICKEY_FILE) {
4869 * We have our passphrase. Now try the actual authentication.
4871 struct ssh2_userkey *key;
4873 key = ssh2_load_userkey(cfg.keyfile, s->password);
4874 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4875 if (key == SSH2_WRONG_PASSPHRASE) {
4876 c_write_str(ssh, "Wrong passphrase\r\n");
4877 s->tried_pubkey_config = FALSE;
4879 c_write_str(ssh, "Unable to load private key\r\n");
4880 s->tried_pubkey_config = TRUE;
4882 /* Send a spurious AUTH_NONE to return to the top. */
4883 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4884 ssh2_pkt_addstring(ssh, s->username);
4885 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4886 ssh2_pkt_addstring(ssh, "none"); /* method */
4888 s->type = AUTH_TYPE_NONE;
4890 unsigned char *pkblob, *sigblob, *sigdata;
4891 int pkblob_len, sigblob_len, sigdata_len;
4894 * We have loaded the private key and the server
4895 * has announced that it's willing to accept it.
4896 * Hallelujah. Generate a signature and send it.
4898 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4899 ssh2_pkt_addstring(ssh, s->username);
4900 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4901 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4902 ssh2_pkt_addbool(ssh, TRUE);
4903 ssh2_pkt_addstring(ssh, key->alg->name);
4904 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4905 ssh2_pkt_addstring_start(ssh);
4906 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
4909 * The data to be signed is:
4913 * followed by everything so far placed in the
4916 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4917 sigdata = smalloc(sigdata_len);
4918 PUT_32BIT(sigdata, 20);
4919 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4920 memcpy(sigdata + 24, ssh->pktout.data + 5,
4921 ssh->pktout.length - 5);
4922 sigblob = key->alg->sign(key->data, sigdata,
4923 sigdata_len, &sigblob_len);
4924 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4925 sigblob, sigblob_len);
4931 s->type = AUTH_TYPE_PUBLICKEY;
4933 } else if (s->method == AUTH_PASSWORD) {
4935 * We send the password packet lumped tightly together with
4936 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4937 * string long enough to make the total length of the two
4938 * packets constant. This should ensure that a passive
4939 * listener doing traffic analyis can't work out the length
4942 * For this to work, we need an assumption about the
4943 * maximum length of the password packet. I think 256 is
4944 * pretty conservative. Anyone using a password longer than
4945 * that probably doesn't have much to worry about from
4946 * people who find out how long their password is!
4948 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4949 ssh2_pkt_addstring(ssh, s->username);
4950 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4951 ssh2_pkt_addstring(ssh, "password");
4952 ssh2_pkt_addbool(ssh, FALSE);
4953 ssh2_pkt_addstring(ssh, s->password);
4954 ssh2_pkt_defer(ssh);
4956 * We'll include a string that's an exact multiple of the
4957 * cipher block size. If the cipher is NULL for some
4958 * reason, we don't do this trick at all because we gain
4961 if (ssh->cscipher) {
4964 stringlen = (256 - ssh->deferred_len);
4965 stringlen += ssh->cscipher->blksize - 1;
4966 stringlen -= (stringlen % ssh->cscipher->blksize);
4969 * Temporarily disable actual compression,
4970 * so we can guarantee to get this string
4971 * exactly the length we want it. The
4972 * compression-disabling routine should
4973 * return an integer indicating how many
4974 * bytes we should adjust our string length
4978 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4980 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4981 ssh2_pkt_addstring_start(ssh);
4982 for (i = 0; i < stringlen; i++) {
4983 char c = (char) random_byte();
4984 ssh2_pkt_addstring_data(ssh, &c, 1);
4986 ssh2_pkt_defer(ssh);
4988 ssh_pkt_defersend(ssh);
4989 logevent("Sent password");
4990 s->type = AUTH_TYPE_PASSWORD;
4991 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4992 if (s->curr_prompt == 0) {
4993 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4994 ssh2_pkt_adduint32(ssh, s->num_prompts);
4996 if (s->need_pw) { /* only add pw if we just got one! */
4997 ssh2_pkt_addstring(ssh, s->password);
4998 memset(s->password, 0, sizeof(s->password));
5001 if (s->curr_prompt >= s->num_prompts) {
5005 * If there are prompts remaining, we set
5006 * `gotit' so that we won't attempt to get
5007 * another packet. Then we go back round the
5008 * loop and will end up retrieving another
5009 * prompt out of the existing packet. Funky or
5014 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5016 c_write_str(ssh, "No supported authentication methods"
5017 " left to try!\r\n");
5018 logevent("No supported authentications offered."
5020 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5021 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5022 ssh2_pkt_addstring(ssh, "No supported authentication"
5023 " methods available");
5024 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5026 ssh->state = SSH_STATE_CLOSED;
5030 } while (!s->we_are_in);
5033 * Now we're authenticated for the connection protocol. The
5034 * connection protocol will automatically have started at this
5035 * point; there's no need to send SERVICE_REQUEST.
5039 * So now create a channel with a session in it.
5041 ssh->channels = newtree234(ssh_channelcmp);
5042 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5043 ssh->mainchan->ssh = ssh;
5044 ssh->mainchan->localid = alloc_channel_id(ssh);
5045 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5046 ssh2_pkt_addstring(ssh, "session");
5047 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5048 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5049 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5050 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5052 crWaitUntilV(ispkt);
5053 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5054 bombout((ssh,"Server refused to open a session"));
5056 /* FIXME: error data comes back in FAILURE packet */
5058 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5059 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5062 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5063 ssh->mainchan->type = CHAN_MAINSESSION;
5064 ssh->mainchan->closes = 0;
5065 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5066 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5067 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5068 add234(ssh->channels, ssh->mainchan);
5069 logevent("Opened channel for session");
5072 * Potentially enable X11 forwarding.
5074 if (cfg.x11_forward) {
5075 char proto[20], data[64];
5076 logevent("Requesting X11 forwarding");
5077 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5078 data, sizeof(data));
5079 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5080 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5081 ssh2_pkt_addstring(ssh, "x11-req");
5082 ssh2_pkt_addbool(ssh, 1); /* want reply */
5083 ssh2_pkt_addbool(ssh, 0); /* many connections */
5084 ssh2_pkt_addstring(ssh, proto);
5085 ssh2_pkt_addstring(ssh, data);
5086 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5090 crWaitUntilV(ispkt);
5091 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5092 unsigned i = ssh2_pkt_getuint32(ssh);
5093 struct ssh_channel *c;
5094 c = find234(ssh->channels, &i, ssh_channelfind);
5096 continue; /* nonexistent channel */
5097 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5099 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5101 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5102 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5103 bombout((ssh,"Unexpected response to X11 forwarding request:"
5104 " packet type %d", ssh->pktin.type));
5107 logevent("X11 forwarding refused");
5109 logevent("X11 forwarding enabled");
5110 ssh->X11_fwd_enabled = TRUE;
5115 * Enable port forwardings.
5120 int sport,dport,sserv,dserv;
5121 char sports[256], dports[256], saddr[256], host[256];
5123 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5124 /* Add port forwardings. */
5125 ssh->portfwd_strptr = cfg.portfwd;
5126 while (*ssh->portfwd_strptr) {
5127 type = *ssh->portfwd_strptr++;
5130 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t') {
5131 if (*ssh->portfwd_strptr == ':') {
5133 * We've seen a colon in the middle of the
5134 * source port number. This means that
5135 * everything we've seen until now is the
5136 * source _address_, so we'll move it into
5137 * saddr and start sports from the beginning
5140 ssh->portfwd_strptr++;
5142 strcpy(saddr, sports);
5145 if (n < 255) sports[n++] = *ssh->portfwd_strptr++;
5148 if (*ssh->portfwd_strptr == '\t')
5149 ssh->portfwd_strptr++;
5151 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':') {
5152 if (n < 255) host[n++] = *ssh->portfwd_strptr++;
5155 if (*ssh->portfwd_strptr == ':')
5156 ssh->portfwd_strptr++;
5158 while (*ssh->portfwd_strptr) {
5159 if (n < 255) dports[n++] = *ssh->portfwd_strptr++;
5162 ssh->portfwd_strptr++;
5163 dport = atoi(dports);
5167 dport = net_service_lookup(dports);
5169 logeventf(ssh, "Service lookup failed for destination"
5170 " port \"%s\"", dports);
5173 sport = atoi(sports);
5177 sport = net_service_lookup(sports);
5179 logeventf(ssh, "Service lookup failed for source"
5180 " port \"%s\"", sports);
5183 if (sport && dport) {
5185 pfd_addforward(host, dport, *saddr ? saddr : NULL,
5187 logeventf(ssh, "Local port %.*s%.*s%.*s%.*s%d%.*s"
5188 " forwarding to %s:%.*s%.*s%d%.*s",
5189 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
5190 (int)(*saddr?1:0), ":",
5191 (int)(sserv ? strlen(sports) : 0), sports,
5192 sserv, "(", sport, sserv, ")",
5194 (int)(dserv ? strlen(dports) : 0), dports,
5195 dserv, "(", dport, dserv, ")");
5197 struct ssh_rportfwd *pf;
5198 pf = smalloc(sizeof(*pf));
5199 strcpy(pf->dhost, host);
5202 if (add234(ssh->rportfwds, pf) != pf) {
5203 logeventf(ssh, "Duplicate remote port forwarding"
5204 " to %s:%d", host, dport);
5207 logeventf(ssh, "Requesting remote port "
5208 "%.*s%.*s%.*s%.*s%d%.*s"
5209 " forward to %s:%.*s%.*s%d%.*s",
5210 (int)(*saddr?strlen(saddr):0),
5212 (int)(*saddr?1:0), ":",
5213 (int)(sserv ? strlen(sports) : 0), sports,
5214 sserv, "(", sport, sserv, ")",
5216 (int)(dserv ? strlen(dports) : 0), dports,
5217 dserv, "(", dport, dserv, ")");
5218 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5219 ssh2_pkt_addstring(ssh, "tcpip-forward");
5220 ssh2_pkt_addbool(ssh, 1);/* want reply */
5222 ssh2_pkt_addstring(ssh, saddr);
5223 if (cfg.rport_acceptall)
5224 ssh2_pkt_addstring(ssh, "0.0.0.0");
5226 ssh2_pkt_addstring(ssh, "127.0.0.1");
5227 ssh2_pkt_adduint32(ssh, sport);
5231 crWaitUntilV(ispkt);
5232 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5233 unsigned i = ssh2_pkt_getuint32(ssh);
5234 struct ssh_channel *c;
5235 c = find234(ssh->channels, &i, ssh_channelfind);
5237 continue;/* nonexistent channel */
5238 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5240 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5242 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5243 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5244 bombout((ssh,"Unexpected response to port "
5245 "forwarding request: packet type %d",
5249 logevent("Server refused this port forwarding");
5251 logevent("Remote port forwarding enabled");
5260 * Potentially enable agent forwarding.
5262 if (cfg.agentfwd && agent_exists()) {
5263 logevent("Requesting OpenSSH-style agent forwarding");
5264 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5265 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5266 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5267 ssh2_pkt_addbool(ssh, 1); /* want reply */
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 agent forwarding request:"
5285 " packet type %d", ssh->pktin.type));
5288 logevent("Agent forwarding refused");
5290 logevent("Agent forwarding enabled");
5291 ssh->agentfwd_enabled = TRUE;
5296 * Now allocate a pty for the session.
5299 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5300 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5301 ssh2_pkt_addstring(ssh, "pty-req");
5302 ssh2_pkt_addbool(ssh, 1); /* want reply */
5303 ssh2_pkt_addstring(ssh, cfg.termtype);
5304 ssh2_pkt_adduint32(ssh, ssh->term_width);
5305 ssh2_pkt_adduint32(ssh, ssh->term_height);
5306 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5307 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5308 ssh2_pkt_addstring_start(ssh);
5309 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5311 ssh->state = SSH_STATE_INTERMED;
5314 crWaitUntilV(ispkt);
5315 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5316 unsigned i = ssh2_pkt_getuint32(ssh);
5317 struct ssh_channel *c;
5318 c = find234(ssh->channels, &i, ssh_channelfind);
5320 continue; /* nonexistent channel */
5321 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5323 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5325 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5326 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5327 bombout((ssh,"Unexpected response to pty request:"
5328 " packet type %d", ssh->pktin.type));
5331 c_write_str(ssh, "Server refused to allocate pty\r\n");
5332 ssh->editing = ssh->echoing = 1;
5334 logevent("Allocated pty");
5337 ssh->editing = ssh->echoing = 1;
5341 * Start a shell or a remote command. We may have to attempt
5342 * this twice if the config data has provided a second choice
5349 if (ssh->fallback_cmd) {
5350 subsys = cfg.ssh_subsys2;
5351 cmd = cfg.remote_cmd_ptr2;
5353 subsys = cfg.ssh_subsys;
5354 cmd = cfg.remote_cmd_ptr;
5357 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5358 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5360 ssh2_pkt_addstring(ssh, "subsystem");
5361 ssh2_pkt_addbool(ssh, 1); /* want reply */
5362 ssh2_pkt_addstring(ssh, cmd);
5364 ssh2_pkt_addstring(ssh, "exec");
5365 ssh2_pkt_addbool(ssh, 1); /* want reply */
5366 ssh2_pkt_addstring(ssh, cmd);
5368 ssh2_pkt_addstring(ssh, "shell");
5369 ssh2_pkt_addbool(ssh, 1); /* want reply */
5373 crWaitUntilV(ispkt);
5374 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5375 unsigned i = ssh2_pkt_getuint32(ssh);
5376 struct ssh_channel *c;
5377 c = find234(ssh->channels, &i, ssh_channelfind);
5379 continue; /* nonexistent channel */
5380 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5382 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5383 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5384 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5385 bombout((ssh,"Unexpected response to shell/command request:"
5386 " packet type %d", ssh->pktin.type));
5390 * We failed to start the command. If this is the
5391 * fallback command, we really are finished; if it's
5392 * not, and if the fallback command exists, try falling
5393 * back to it before complaining.
5395 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5396 logevent("Primary command failed; attempting fallback");
5397 ssh->fallback_cmd = TRUE;
5400 bombout((ssh,"Server refused to start a shell/command"));
5403 logevent("Started a shell/command");
5408 ssh->state = SSH_STATE_SESSION;
5409 if (ssh->size_needed)
5410 ssh_size(ssh, ssh->term_width, ssh->term_height);
5411 if (ssh->eof_needed)
5412 ssh_special(ssh, TS_EOF);
5418 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5422 s->try_send = FALSE;
5424 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5425 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5428 unsigned i = ssh2_pkt_getuint32(ssh);
5429 struct ssh_channel *c;
5430 c = find234(ssh->channels, &i, ssh_channelfind);
5432 continue; /* nonexistent channel */
5433 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5434 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5435 continue; /* extended but not stderr */
5436 ssh2_pkt_getstring(ssh, &data, &length);
5439 c->v.v2.locwindow -= length;
5441 case CHAN_MAINSESSION:
5443 from_backend(ssh->frontend, ssh->pktin.type ==
5444 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5448 bufsize = x11_send(c->u.x11.s, data, length);
5451 bufsize = pfd_send(c->u.pfd.s, data, length);
5454 while (length > 0) {
5455 if (c->u.a.lensofar < 4) {
5456 int l = min(4 - c->u.a.lensofar, length);
5457 memcpy(c->u.a.msglen + c->u.a.lensofar,
5461 c->u.a.lensofar += l;
5463 if (c->u.a.lensofar == 4) {
5465 4 + GET_32BIT(c->u.a.msglen);
5466 c->u.a.message = smalloc(c->u.a.totallen);
5467 memcpy(c->u.a.message, c->u.a.msglen, 4);
5469 if (c->u.a.lensofar >= 4 && length > 0) {
5471 min(c->u.a.totallen - c->u.a.lensofar,
5473 memcpy(c->u.a.message + c->u.a.lensofar,
5477 c->u.a.lensofar += l;
5479 if (c->u.a.lensofar == c->u.a.totallen) {
5480 void *reply, *sentreply;
5482 agent_query(c->u.a.message,
5483 c->u.a.totallen, &reply,
5488 /* Fake SSH_AGENT_FAILURE. */
5489 sentreply = "\0\0\0\1\5";
5492 ssh2_add_channel_data(c, sentreply, replylen);
5496 sfree(c->u.a.message);
5497 c->u.a.lensofar = 0;
5504 * If we are not buffering too much data,
5505 * enlarge the window again at the remote side.
5507 if (bufsize < OUR_V2_WINSIZE)
5508 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5510 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5511 unsigned i = ssh2_pkt_getuint32(ssh);
5512 struct ssh_channel *c;
5514 c = find234(ssh->channels, &i, ssh_channelfind);
5516 continue; /* nonexistent channel */
5518 if (c->type == CHAN_X11) {
5520 * Remote EOF on an X11 channel means we should
5521 * wrap up and close the channel ourselves.
5523 x11_close(c->u.x11.s);
5525 } else if (c->type == CHAN_AGENT) {
5527 } else if (c->type == CHAN_SOCKDATA) {
5528 pfd_close(c->u.pfd.s);
5531 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5532 unsigned i = ssh2_pkt_getuint32(ssh);
5533 struct ssh_channel *c;
5535 c = find234(ssh->channels, &i, ssh_channelfind);
5536 if (!c || ((int)c->remoteid) == -1) {
5537 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5538 c ? "half-open" : "nonexistent", i));
5540 /* Do pre-close processing on the channel. */
5542 case CHAN_MAINSESSION:
5543 break; /* nothing to see here, move along */
5545 if (c->u.x11.s != NULL)
5546 x11_close(c->u.x11.s);
5553 if (c->u.pfd.s != NULL)
5554 pfd_close(c->u.pfd.s);
5558 if (c->closes == 0) {
5559 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5560 ssh2_pkt_adduint32(ssh, c->remoteid);
5563 del234(ssh->channels, c);
5564 bufchain_clear(&c->v.v2.outbuffer);
5568 * See if that was the last channel left open.
5570 if (count234(ssh->channels) == 0) {
5573 * We used to send SSH_MSG_DISCONNECT here,
5574 * because I'd believed that _every_ conforming
5575 * SSH2 connection had to end with a disconnect
5576 * being sent by at least one side; apparently
5577 * I was wrong and it's perfectly OK to
5578 * unceremoniously slam the connection shut
5579 * when you're done, and indeed OpenSSH feels
5580 * this is more polite than sending a
5581 * DISCONNECT. So now we don't.
5583 logevent("All channels closed. Disconnecting");
5584 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5585 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5586 ssh2_pkt_addstring(ssh, "All open channels closed");
5587 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5590 ssh->state = SSH_STATE_CLOSED;
5593 continue; /* remote sends close; ignore (FIXME) */
5594 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5595 unsigned i = ssh2_pkt_getuint32(ssh);
5596 struct ssh_channel *c;
5597 c = find234(ssh->channels, &i, ssh_channelfind);
5599 continue; /* nonexistent channel */
5600 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5602 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5603 unsigned i = ssh2_pkt_getuint32(ssh);
5604 struct ssh_channel *c;
5605 c = find234(ssh->channels, &i, ssh_channelfind);
5607 continue; /* nonexistent channel */
5608 if (c->type != CHAN_SOCKDATA_DORMANT)
5609 continue; /* dunno why they're confirming this */
5610 c->remoteid = ssh2_pkt_getuint32(ssh);
5611 c->type = CHAN_SOCKDATA;
5612 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5613 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5615 pfd_confirm(c->u.pfd.s);
5618 * We have a pending close on this channel,
5619 * which we decided on before the server acked
5620 * the channel open. So now we know the
5621 * remoteid, we can close it again.
5623 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5624 ssh2_pkt_adduint32(ssh, c->remoteid);
5627 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5628 unsigned i = ssh2_pkt_getuint32(ssh);
5629 struct ssh_channel *c;
5630 c = find234(ssh->channels, &i, ssh_channelfind);
5632 continue; /* nonexistent channel */
5633 if (c->type != CHAN_SOCKDATA_DORMANT)
5634 continue; /* dunno why they're failing this */
5636 logevent("Forwarded connection refused by server");
5638 pfd_close(c->u.pfd.s);
5640 del234(ssh->channels, c);
5642 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5645 int typelen, want_reply;
5646 struct ssh_channel *c;
5648 localid = ssh2_pkt_getuint32(ssh);
5649 ssh2_pkt_getstring(ssh, &type, &typelen);
5650 want_reply = ssh2_pkt_getbool(ssh);
5653 * First, check that the channel exists. Otherwise,
5654 * we can instantly disconnect with a rude message.
5656 c = find234(ssh->channels, &localid, ssh_channelfind);
5659 sprintf(buf, "Received channel request for nonexistent"
5660 " channel %d", localid);
5662 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5663 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5664 ssh2_pkt_addstring(ssh, buf);
5665 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5667 connection_fatal("%s", buf);
5668 ssh->state = SSH_STATE_CLOSED;
5673 * Having got the channel number, we now look at
5674 * the request type string to see if it's something
5677 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5678 c == ssh->mainchan) {
5679 /* We recognise "exit-status" on the primary channel. */
5681 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5682 sprintf(buf, "Server sent command exit status %d",
5686 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5687 ssh2_pkt_adduint32(ssh, c->remoteid);
5692 * This is a channel request we don't know
5693 * about, so we now either ignore the request
5694 * or respond with CHANNEL_FAILURE, depending
5698 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5699 ssh2_pkt_adduint32(ssh, c->remoteid);
5703 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5705 int typelen, want_reply;
5707 ssh2_pkt_getstring(ssh, &type, &typelen);
5708 want_reply = ssh2_pkt_getbool(ssh);
5711 * We currently don't support any global requests
5712 * at all, so we either ignore the request or
5713 * respond with REQUEST_FAILURE, depending on
5717 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5720 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5724 struct ssh_channel *c;
5725 unsigned remid, winsize, pktsize;
5726 ssh2_pkt_getstring(ssh, &type, &typelen);
5727 c = smalloc(sizeof(struct ssh_channel));
5730 remid = ssh2_pkt_getuint32(ssh);
5731 winsize = ssh2_pkt_getuint32(ssh);
5732 pktsize = ssh2_pkt_getuint32(ssh);
5734 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5735 if (!ssh->X11_fwd_enabled)
5736 error = "X11 forwarding is not enabled";
5737 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5738 ssh->x11auth) != NULL) {
5739 error = "Unable to open an X11 connection";
5743 } else if (typelen == 15 &&
5744 !memcmp(type, "forwarded-tcpip", 15)) {
5745 struct ssh_rportfwd pf, *realpf;
5748 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5749 pf.sport = ssh2_pkt_getuint32(ssh);
5750 realpf = find234(ssh->rportfwds, &pf, NULL);
5751 if (realpf == NULL) {
5752 error = "Remote port is not recognised";
5754 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5756 logeventf(ssh, "Received remote port open request"
5757 " for %s:%d", realpf->dhost, realpf->dport);
5759 logeventf(ssh, "Port open failed: %s", e);
5760 error = "Port open failed";
5762 logevent("Forwarded port opened successfully");
5763 c->type = CHAN_SOCKDATA;
5766 } else if (typelen == 22 &&
5767 !memcmp(type, "auth-agent@openssh.com", 3)) {
5768 if (!ssh->agentfwd_enabled)
5769 error = "Agent forwarding is not enabled";
5771 c->type = CHAN_AGENT; /* identify channel type */
5772 c->u.a.lensofar = 0;
5775 error = "Unsupported channel type requested";
5778 c->remoteid = remid;
5780 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5781 ssh2_pkt_adduint32(ssh, c->remoteid);
5782 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5783 ssh2_pkt_addstring(ssh, error);
5784 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5788 c->localid = alloc_channel_id(ssh);
5790 c->v.v2.locwindow = OUR_V2_WINSIZE;
5791 c->v.v2.remwindow = winsize;
5792 c->v.v2.remmaxpkt = pktsize;
5793 bufchain_init(&c->v.v2.outbuffer);
5794 add234(ssh->channels, c);
5795 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5796 ssh2_pkt_adduint32(ssh, c->remoteid);
5797 ssh2_pkt_adduint32(ssh, c->localid);
5798 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5799 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5803 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5808 * We have spare data. Add it to the channel buffer.
5810 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5815 struct ssh_channel *c;
5817 * Try to send data on all channels if we can.
5819 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5820 int bufsize = ssh2_try_send(c);
5823 case CHAN_MAINSESSION:
5824 /* stdin need not receive an unthrottle
5825 * notification since it will be polled */
5828 x11_unthrottle(c->u.x11.s);
5831 /* agent sockets are request/response and need no
5832 * buffer management */
5835 pfd_unthrottle(c->u.pfd.s);
5847 * Handle the top-level SSH2 protocol.
5849 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5851 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5853 do_ssh2_authconn(ssh, in, inlen, ispkt);
5857 * Called to set up the connection.
5859 * Returns an error message, or NULL on success.
5861 static char *ssh_init(void *frontend_handle, void **backend_handle,
5862 char *host, int port, char **realhost, int nodelay)
5867 ssh = smalloc(sizeof(*ssh));
5870 ssh->v1_cipher_ctx = NULL;
5871 ssh->crcda_ctx = NULL;
5872 ssh->cscipher = NULL;
5873 ssh->cs_cipher_ctx = NULL;
5874 ssh->sccipher = NULL;
5875 ssh->sc_cipher_ctx = NULL;
5877 ssh->cs_mac_ctx = NULL;
5879 ssh->sc_mac_ctx = NULL;
5881 ssh->cs_comp_ctx = NULL;
5883 ssh->sc_comp_ctx = NULL;
5885 ssh->hostkey = NULL;
5887 ssh->state = SSH_STATE_PREPACKET;
5888 ssh->size_needed = FALSE;
5889 ssh->eof_needed = FALSE;
5893 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5894 ssh->pktin = ssh->pktout = empty;
5896 ssh->deferred_send_data = NULL;
5897 ssh->deferred_len = 0;
5898 ssh->deferred_size = 0;
5899 ssh->fallback_cmd = 0;
5901 ssh->x11auth = NULL;
5902 ssh->v1_compressing = FALSE;
5903 ssh->v2_outgoing_sequence = 0;
5904 ssh->ssh1_rdpkt_crstate = 0;
5905 ssh->ssh2_rdpkt_crstate = 0;
5906 ssh->do_ssh_init_crstate = 0;
5907 ssh->ssh_gotdata_crstate = 0;
5908 ssh->ssh1_protocol_crstate = 0;
5909 ssh->do_ssh1_login_crstate = 0;
5910 ssh->do_ssh2_transport_crstate = 0;
5911 ssh->do_ssh2_authconn_crstate = 0;
5912 ssh->do_ssh_init_state = NULL;
5913 ssh->do_ssh1_login_state = NULL;
5914 ssh->do_ssh2_transport_state = NULL;
5915 ssh->do_ssh2_authconn_state = NULL;
5916 ssh->mainchan = NULL;
5917 ssh->throttled_all = 0;
5918 ssh->v1_stdout_throttling = 0;
5920 *backend_handle = ssh;
5923 if (crypto_startup() == 0)
5924 return "Microsoft high encryption pack not installed!";
5927 ssh->frontend = frontend_handle;
5928 ssh->term_width = cfg.width;
5929 ssh->term_height = cfg.height;
5934 ssh->v1_throttle_count = 0;
5935 ssh->overall_bufsize = 0;
5936 ssh->fallback_cmd = 0;
5938 p = connect_to_host(ssh, host, port, realhost, nodelay);
5946 * Called to send data down the Telnet connection.
5948 static int ssh_send(void *handle, char *buf, int len)
5950 Ssh ssh = (Ssh) handle;
5952 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5955 ssh->protocol(ssh, buf, len, 0);
5957 return ssh_sendbuffer(ssh);
5961 * Called to query the current amount of buffered stdin data.
5963 static int ssh_sendbuffer(void *handle)
5965 Ssh ssh = (Ssh) handle;
5968 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5972 * If the SSH socket itself has backed up, add the total backup
5973 * size on that to any individual buffer on the stdin channel.
5976 if (ssh->throttled_all)
5977 override_value = ssh->overall_bufsize;
5979 if (ssh->version == 1) {
5980 return override_value;
5981 } else if (ssh->version == 2) {
5982 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5983 return override_value;
5985 return (override_value +
5986 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5993 * Called to set the size of the window from SSH's POV.
5995 static void ssh_size(void *handle, int width, int height)
5997 Ssh ssh = (Ssh) handle;
5999 ssh->term_width = width;
6000 ssh->term_height = height;
6002 switch (ssh->state) {
6003 case SSH_STATE_BEFORE_SIZE:
6004 case SSH_STATE_PREPACKET:
6005 case SSH_STATE_CLOSED:
6006 break; /* do nothing */
6007 case SSH_STATE_INTERMED:
6008 ssh->size_needed = TRUE; /* buffer for later */
6010 case SSH_STATE_SESSION:
6012 if (ssh->version == 1) {
6013 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6014 PKT_INT, ssh->term_height,
6015 PKT_INT, ssh->term_width,
6016 PKT_INT, 0, PKT_INT, 0, PKT_END);
6018 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6019 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6020 ssh2_pkt_addstring(ssh, "window-change");
6021 ssh2_pkt_addbool(ssh, 0);
6022 ssh2_pkt_adduint32(ssh, ssh->term_width);
6023 ssh2_pkt_adduint32(ssh, ssh->term_height);
6024 ssh2_pkt_adduint32(ssh, 0);
6025 ssh2_pkt_adduint32(ssh, 0);
6034 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6035 * can send an EOF and collect resulting output (e.g. `plink
6038 static void ssh_special(void *handle, Telnet_Special code)
6040 Ssh ssh = (Ssh) handle;
6042 if (code == TS_EOF) {
6043 if (ssh->state != SSH_STATE_SESSION) {
6045 * Buffer the EOF in case we are pre-SESSION, so we can
6046 * send it as soon as we reach SESSION.
6049 ssh->eof_needed = TRUE;
6052 if (ssh->version == 1) {
6053 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6055 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6056 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6059 logevent("Sent EOF message");
6060 } else if (code == TS_PING) {
6061 if (ssh->state == SSH_STATE_CLOSED
6062 || ssh->state == SSH_STATE_PREPACKET) return;
6063 if (ssh->version == 1) {
6064 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6065 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6067 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6068 ssh2_pkt_addstring_start(ssh);
6076 void *new_sock_channel(void *handle, Socket s)
6078 Ssh ssh = (Ssh) handle;
6079 struct ssh_channel *c;
6080 c = smalloc(sizeof(struct ssh_channel));
6084 c->remoteid = -1; /* to be set when open confirmed */
6085 c->localid = alloc_channel_id(ssh);
6087 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6089 bufchain_init(&c->v.v2.outbuffer);
6090 add234(ssh->channels, c);
6096 * This is called when stdout/stderr (the entity to which
6097 * from_backend sends data) manages to clear some backlog.
6099 void ssh_unthrottle(void *handle, int bufsize)
6101 Ssh ssh = (Ssh) handle;
6102 if (ssh->version == 1) {
6103 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6104 ssh->v1_stdout_throttling = 0;
6105 ssh1_throttle(ssh, -1);
6108 if (ssh->mainchan && ssh->mainchan->closes == 0)
6109 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6113 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6115 struct ssh_channel *c = (struct ssh_channel *)channel;
6118 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
6120 if (ssh->version == 1) {
6121 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6122 PKT_INT, c->localid,
6125 //PKT_STR, <org:orgport>,
6128 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6129 ssh2_pkt_addstring(ssh, "direct-tcpip");
6130 ssh2_pkt_adduint32(ssh, c->localid);
6131 c->v.v2.locwindow = OUR_V2_WINSIZE;
6132 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6133 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6134 ssh2_pkt_addstring(ssh, hostname);
6135 ssh2_pkt_adduint32(ssh, port);
6137 * We make up values for the originator data; partly it's
6138 * too much hassle to keep track, and partly I'm not
6139 * convinced the server should be told details like that
6140 * about my local network configuration.
6142 ssh2_pkt_addstring(ssh, "client-side-connection");
6143 ssh2_pkt_adduint32(ssh, 0);
6149 static Socket ssh_socket(void *handle)
6151 Ssh ssh = (Ssh) handle;
6155 static int ssh_sendok(void *handle)
6157 Ssh ssh = (Ssh) handle;
6158 return ssh->send_ok;
6161 static int ssh_ldisc(void *handle, int option)
6163 Ssh ssh = (Ssh) handle;
6164 if (option == LD_ECHO)
6165 return ssh->echoing;
6166 if (option == LD_EDIT)
6167 return ssh->editing;
6171 static void ssh_provide_ldisc(void *handle, void *ldisc)
6173 Ssh ssh = (Ssh) handle;
6177 static void ssh_provide_logctx(void *handle, void *logctx)
6179 Ssh ssh = (Ssh) handle;
6180 ssh->logctx = logctx;
6183 static int ssh_return_exitcode(void *handle)
6185 Ssh ssh = (Ssh) handle;
6186 return ssh->exitcode;
6190 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6191 * that fails. This variable is the means by which scp.c can reach
6192 * into the SSH code and find out which one it got.
6194 extern int ssh_fallback_cmd(void *handle)
6196 Ssh ssh = (Ssh) handle;
6197 return ssh->fallback_cmd;
6200 Backend ssh_backend = {
6207 ssh_return_exitcode,