17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP1 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_PUBLICKEY 0x0010
110 #define SSH2_PKTCTX_PASSWORD 0x0020
111 #define SSH2_PKTCTX_KBDINTER 0x0040
112 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
114 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
115 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
116 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
117 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
118 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
119 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
120 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
121 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
122 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
123 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
124 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
125 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
126 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
127 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
128 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
130 static const char *const ssh2_disconnect_reasons[] = {
132 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
133 "SSH_DISCONNECT_PROTOCOL_ERROR",
134 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
135 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
136 "SSH_DISCONNECT_MAC_ERROR",
137 "SSH_DISCONNECT_COMPRESSION_ERROR",
138 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
139 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
140 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
141 "SSH_DISCONNECT_CONNECTION_LOST",
142 "SSH_DISCONNECT_BY_APPLICATION",
143 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
144 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
145 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
146 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
149 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
150 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
151 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
152 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
154 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
157 * Various remote-bug flags.
159 #define BUG_CHOKES_ON_SSH1_IGNORE 1
160 #define BUG_SSH2_HMAC 2
161 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
162 #define BUG_CHOKES_ON_RSA 8
163 #define BUG_SSH2_RSA_PADDING 16
164 #define BUG_SSH2_DERIVEKEY 32
165 #define BUG_SSH2_DH_GEX 64
167 #define translate(x) if (type == x) return #x
168 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
169 char *ssh1_pkt_type(int type)
171 translate(SSH1_MSG_DISCONNECT);
172 translate(SSH1_SMSG_PUBLIC_KEY);
173 translate(SSH1_CMSG_SESSION_KEY);
174 translate(SSH1_CMSG_USER);
175 translate(SSH1_CMSG_AUTH_RSA);
176 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
177 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
178 translate(SSH1_CMSG_AUTH_PASSWORD);
179 translate(SSH1_CMSG_REQUEST_PTY);
180 translate(SSH1_CMSG_WINDOW_SIZE);
181 translate(SSH1_CMSG_EXEC_SHELL);
182 translate(SSH1_CMSG_EXEC_CMD);
183 translate(SSH1_SMSG_SUCCESS);
184 translate(SSH1_SMSG_FAILURE);
185 translate(SSH1_CMSG_STDIN_DATA);
186 translate(SSH1_SMSG_STDOUT_DATA);
187 translate(SSH1_SMSG_STDERR_DATA);
188 translate(SSH1_CMSG_EOF);
189 translate(SSH1_SMSG_EXIT_STATUS);
190 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
191 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
192 translate(SSH1_MSG_CHANNEL_DATA);
193 translate(SSH1_MSG_CHANNEL_CLOSE);
194 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
195 translate(SSH1_SMSG_X11_OPEN);
196 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
197 translate(SSH1_MSG_PORT_OPEN);
198 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
199 translate(SSH1_SMSG_AGENT_OPEN);
200 translate(SSH1_MSG_IGNORE);
201 translate(SSH1_CMSG_EXIT_CONFIRMATION);
202 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
203 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
204 translate(SSH1_MSG_DEBUG);
205 translate(SSH1_CMSG_REQUEST_COMPRESSION);
206 translate(SSH1_CMSG_AUTH_TIS);
207 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
208 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
209 translate(SSH1_CMSG_AUTH_CCARD);
210 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
211 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
214 char *ssh2_pkt_type(int pkt_ctx, int type)
216 translate(SSH2_MSG_DISCONNECT);
217 translate(SSH2_MSG_IGNORE);
218 translate(SSH2_MSG_UNIMPLEMENTED);
219 translate(SSH2_MSG_DEBUG);
220 translate(SSH2_MSG_SERVICE_REQUEST);
221 translate(SSH2_MSG_SERVICE_ACCEPT);
222 translate(SSH2_MSG_KEXINIT);
223 translate(SSH2_MSG_NEWKEYS);
224 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
225 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
226 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
227 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
228 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
230 translate(SSH2_MSG_USERAUTH_REQUEST);
231 translate(SSH2_MSG_USERAUTH_FAILURE);
232 translate(SSH2_MSG_USERAUTH_SUCCESS);
233 translate(SSH2_MSG_USERAUTH_BANNER);
234 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
235 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
236 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
237 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
238 translate(SSH2_MSG_GLOBAL_REQUEST);
239 translate(SSH2_MSG_REQUEST_SUCCESS);
240 translate(SSH2_MSG_REQUEST_FAILURE);
241 translate(SSH2_MSG_CHANNEL_OPEN);
242 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
243 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
244 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
245 translate(SSH2_MSG_CHANNEL_DATA);
246 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
247 translate(SSH2_MSG_CHANNEL_EOF);
248 translate(SSH2_MSG_CHANNEL_CLOSE);
249 translate(SSH2_MSG_CHANNEL_REQUEST);
250 translate(SSH2_MSG_CHANNEL_SUCCESS);
251 translate(SSH2_MSG_CHANNEL_FAILURE);
257 #define GET_32BIT(cp) \
258 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
259 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
260 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
261 ((unsigned long)(unsigned char)(cp)[3]))
263 #define PUT_32BIT(cp, value) { \
264 (cp)[0] = (unsigned char)((value) >> 24); \
265 (cp)[1] = (unsigned char)((value) >> 16); \
266 (cp)[2] = (unsigned char)((value) >> 8); \
267 (cp)[3] = (unsigned char)(value); }
269 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
271 /* Coroutine mechanics for the sillier bits of the code */
272 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
275 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
277 #define crFinish(z) } *crLine = 0; return (z); }
278 #define crFinishV } *crLine = 0; return; }
279 #define crReturn(z) \
281 *crLine =__LINE__; return (z); case __LINE__:;\
285 *crLine=__LINE__; return; case __LINE__:;\
287 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
288 #define crStopV do{ *crLine = 0; return; }while(0)
289 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
290 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
292 typedef struct ssh_tag *Ssh;
294 extern char *x11_init(Socket *, char *, void *, void *);
295 extern void x11_close(Socket);
296 extern int x11_send(Socket, char *, int);
297 extern void *x11_invent_auth(char *, int, char *, int);
298 extern void x11_unthrottle(Socket s);
299 extern void x11_override_throttle(Socket s, int enable);
301 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
302 extern char *pfd_addforward(char *desthost, int destport, int port,
304 extern void pfd_close(Socket s);
305 extern int pfd_send(Socket s, char *data, int len);
306 extern void pfd_confirm(Socket s);
307 extern void pfd_unthrottle(Socket s);
308 extern void pfd_override_throttle(Socket s, int enable);
310 static void ssh2_pkt_init(Ssh, int pkt_type);
311 static void ssh2_pkt_addbool(Ssh, unsigned char value);
312 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
313 static void ssh2_pkt_addstring_start(Ssh);
314 static void ssh2_pkt_addstring_str(Ssh, char *data);
315 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
316 static void ssh2_pkt_addstring(Ssh, char *data);
317 static char *ssh2_mpint_fmt(Bignum b, int *len);
318 static void ssh2_pkt_addmp(Ssh, Bignum b);
319 static int ssh2_pkt_construct(Ssh);
320 static void ssh2_pkt_send(Ssh);
323 * Buffer management constants. There are several of these for
324 * various different purposes:
326 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
327 * on a local data stream before we throttle the whole SSH
328 * connection (in SSH1 only). Throttling the whole connection is
329 * pretty drastic so we set this high in the hope it won't
332 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
333 * on the SSH connection itself before we defensively throttle
334 * _all_ local data streams. This is pretty drastic too (though
335 * thankfully unlikely in SSH2 since the window mechanism should
336 * ensure that the server never has any need to throttle its end
337 * of the connection), so we set this high as well.
339 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
343 #define SSH1_BUFFER_LIMIT 32768
344 #define SSH_MAX_BACKLOG 32768
345 #define OUR_V2_WINSIZE 16384
347 const static struct ssh_kex *kex_algs[] = {
348 &ssh_diffiehellman_gex,
352 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
354 static void *nullmac_make_context(void)
358 static void nullmac_free_context(void *handle)
361 static void nullmac_key(void *handle, unsigned char *key)
364 static void nullmac_generate(void *handle, unsigned char *blk, int len,
368 static int nullmac_verify(void *handle, unsigned char *blk, int len,
373 const static struct ssh_mac ssh_mac_none = {
374 nullmac_make_context, nullmac_free_context, nullmac_key,
375 nullmac_generate, nullmac_verify, "none", 0
377 const static struct ssh_mac *macs[] = {
378 &ssh_sha1, &ssh_md5, &ssh_mac_none
380 const static struct ssh_mac *buggymacs[] = {
381 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
384 static void *ssh_comp_none_init(void)
388 static void ssh_comp_none_cleanup(void *handle)
391 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
392 unsigned char **outblock, int *outlen)
396 static int ssh_comp_none_disable(void *handle)
400 const static struct ssh_compress ssh_comp_none = {
402 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
403 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
404 ssh_comp_none_disable, NULL
406 extern const struct ssh_compress ssh_zlib;
407 const static struct ssh_compress *compressions[] = {
408 &ssh_zlib, &ssh_comp_none
411 enum { /* channel types */
416 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
420 * 2-3-4 tree storing channels.
423 Ssh ssh; /* pointer back to main context */
424 unsigned remoteid, localid;
427 * In SSH1, this value contains four bits:
429 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
430 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
431 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
432 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
434 * A channel is completely finished with when all four bits are set.
438 struct ssh1_data_channel {
441 struct ssh2_data_channel {
443 unsigned remwindow, remmaxpkt;
448 struct ssh_agent_channel {
449 unsigned char *message;
450 unsigned char msglen[4];
451 int lensofar, totallen;
453 struct ssh_x11_channel {
456 struct ssh_pfd_channel {
463 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
464 * 2 use this structure in different ways, reflecting SSH 2's
465 * altogether saner approach to port forwarding.
467 * In SSH 1, you arrange a remote forwarding by sending the server
468 * the remote port number, and the local destination host:port.
469 * When a connection comes in, the server sends you back that
470 * host:port pair, and you connect to it. This is a ready-made
471 * security hole if you're not on the ball: a malicious server
472 * could send you back _any_ host:port pair, so if you trustingly
473 * connect to the address it gives you then you've just opened the
474 * entire inside of your corporate network just by connecting
475 * through it to a dodgy SSH server. Hence, we must store a list of
476 * host:port pairs we _are_ trying to forward to, and reject a
477 * connection request from the server if it's not in the list.
479 * In SSH 2, each side of the connection minds its own business and
480 * doesn't send unnecessary information to the other. You arrange a
481 * remote forwarding by sending the server just the remote port
482 * number. When a connection comes in, the server tells you which
483 * of its ports was connected to; and _you_ have to remember what
484 * local host:port pair went with that port number.
486 * Hence: in SSH 1 this structure stores host:port pairs we intend
487 * to allow connections to, and is indexed by those host:port
488 * pairs. In SSH 2 it stores a mapping from source port to
489 * destination host:port pair, and is indexed by source port.
491 struct ssh_rportfwd {
492 unsigned sport, dport;
505 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
506 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
507 static void ssh_size(void *handle, int width, int height);
508 static void ssh_special(void *handle, Telnet_Special);
509 static int ssh2_try_send(struct ssh_channel *c);
510 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
511 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
512 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
513 static int ssh_sendbuffer(void *handle);
515 struct rdpkt1_state_tag {
516 long len, pad, biglen, to_read;
517 unsigned long realcrc, gotcrc;
523 struct rdpkt2_state_tag {
524 long len, pad, payload, packetlen, maclen;
527 unsigned long incoming_sequence;
531 const struct plug_function_table *fn;
532 /* the above field _must_ be first in the structure */
534 SHA_State exhash, exhashbase;
541 unsigned char session_key[32];
543 int v1_remote_protoflags;
544 int v1_local_protoflags;
545 int agentfwd_enabled;
548 const struct ssh_cipher *cipher;
551 const struct ssh2_cipher *cscipher, *sccipher;
552 void *cs_cipher_ctx, *sc_cipher_ctx;
553 const struct ssh_mac *csmac, *scmac;
554 void *cs_mac_ctx, *sc_mac_ctx;
555 const struct ssh_compress *cscomp, *sccomp;
556 void *cs_comp_ctx, *sc_comp_ctx;
557 const struct ssh_kex *kex;
558 const struct ssh_signkey *hostkey;
559 unsigned char v2_session_id[20];
565 int echoing, editing;
569 int term_width, term_height;
571 tree234 *channels; /* indexed by local id */
572 struct ssh_channel *mainchan; /* primary session channel */
579 SSH_STATE_BEFORE_SIZE,
585 int size_needed, eof_needed;
588 struct Packet pktout;
589 unsigned char *deferred_send_data;
590 int deferred_len, deferred_size;
593 * Gross hack: pscp will try to start SFTP but fall back to
594 * scp1 if that fails. This variable is the means by which
595 * scp.c can reach into the SSH code and find out which one it
601 * Used for username and password input.
603 char *userpass_input_buffer;
604 int userpass_input_buflen;
605 int userpass_input_bufpos;
606 int userpass_input_echo;
608 char *portfwd_strptr;
614 int v1_throttle_count;
617 int v1_stdout_throttling;
618 int v2_outgoing_sequence;
620 int ssh1_rdpkt_crstate;
621 int ssh2_rdpkt_crstate;
622 int do_ssh_init_crstate;
623 int ssh_gotdata_crstate;
624 int ssh1_protocol_crstate;
625 int do_ssh1_login_crstate;
626 int do_ssh2_transport_crstate;
627 int do_ssh2_authconn_crstate;
629 void *do_ssh_init_state;
630 void *do_ssh1_login_state;
631 void *do_ssh2_transport_state;
632 void *do_ssh2_authconn_state;
634 struct rdpkt1_state_tag rdpkt1_state;
635 struct rdpkt2_state_tag rdpkt2_state;
637 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
638 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
641 #define logevent(s) { logevent(ssh->frontend, s); \
642 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
643 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
645 /* logevent, only printf-formatted. */
646 void logeventf(Ssh ssh, char *fmt, ...)
652 vsprintf(stuff, fmt, ap);
657 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
658 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
659 logeventf msg, connection_fatal msg )
661 static int ssh_channelcmp(void *av, void *bv)
663 struct ssh_channel *a = (struct ssh_channel *) av;
664 struct ssh_channel *b = (struct ssh_channel *) bv;
665 if (a->localid < b->localid)
667 if (a->localid > b->localid)
671 static int ssh_channelfind(void *av, void *bv)
673 unsigned *a = (unsigned *) av;
674 struct ssh_channel *b = (struct ssh_channel *) bv;
682 static int ssh_rportcmp_ssh1(void *av, void *bv)
684 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
685 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
687 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
688 return i < 0 ? -1 : +1;
689 if (a->dport > b->dport)
691 if (a->dport < b->dport)
696 static int ssh_rportcmp_ssh2(void *av, void *bv)
698 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
699 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
701 if (a->sport > b->sport)
703 if (a->sport < b->sport)
708 static int alloc_channel_id(Ssh ssh)
710 const unsigned CHANNEL_NUMBER_OFFSET = 256;
711 unsigned low, high, mid;
713 struct ssh_channel *c;
716 * First-fit allocation of channel numbers: always pick the
717 * lowest unused one. To do this, binary-search using the
718 * counted B-tree to find the largest channel ID which is in a
719 * contiguous sequence from the beginning. (Precisely
720 * everything in that sequence must have ID equal to its tree
721 * index plus CHANNEL_NUMBER_OFFSET.)
723 tsize = count234(ssh->channels);
727 while (high - low > 1) {
728 mid = (high + low) / 2;
729 c = index234(ssh->channels, mid);
730 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
731 low = mid; /* this one is fine */
733 high = mid; /* this one is past it */
736 * Now low points to either -1, or the tree index of the
737 * largest ID in the initial sequence.
740 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
741 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
743 return low + 1 + CHANNEL_NUMBER_OFFSET;
746 static void c_write(Ssh ssh, char *buf, int len)
748 if ((flags & FLAG_STDERR)) {
750 for (i = 0; i < len; i++)
752 fputc(buf[i], stderr);
755 from_backend(ssh->frontend, 1, buf, len);
758 static void c_write_untrusted(Ssh ssh, char *buf, int len)
761 for (i = 0; i < len; i++) {
763 c_write(ssh, "\r\n", 2);
764 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
765 c_write(ssh, buf + i, 1);
769 static void c_write_str(Ssh ssh, char *buf)
771 c_write(ssh, buf, strlen(buf));
775 * Collect incoming data in the incoming packet buffer.
776 * Decipher and verify the packet when it is completely read.
777 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
778 * Update the *data and *datalen variables.
779 * Return the additional nr of bytes needed, or 0 when
780 * a complete packet is available.
782 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
784 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
786 crBegin(ssh->ssh1_rdpkt_crstate);
791 ssh->pktin.length = 0;
793 for (st->i = st->len = 0; st->i < 4; st->i++) {
794 while ((*datalen) == 0)
796 st->len = (st->len << 8) + **data;
797 (*data)++, (*datalen)--;
800 st->pad = 8 - (st->len % 8);
801 st->biglen = st->len + st->pad;
802 ssh->pktin.length = st->len - 5;
804 if (ssh->pktin.maxlen < st->biglen) {
805 ssh->pktin.maxlen = st->biglen;
806 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
809 st->to_read = st->biglen;
810 st->p = ssh->pktin.data;
811 while (st->to_read > 0) {
812 st->chunk = st->to_read;
813 while ((*datalen) == 0)
814 crReturn(st->to_read);
815 if (st->chunk > (*datalen))
816 st->chunk = (*datalen);
817 memcpy(st->p, *data, st->chunk);
819 *datalen -= st->chunk;
821 st->to_read -= st->chunk;
824 if (ssh->cipher && detect_attack(ssh->crcda_ctx, ssh->pktin.data,
826 bombout((ssh,"Network attack (CRC compensation) detected!"));
831 ssh->cipher->decrypt(ssh->v1_cipher_ctx, ssh->pktin.data, st->biglen);
833 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
834 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
835 if (st->gotcrc != st->realcrc) {
836 bombout((ssh,"Incorrect CRC received on packet"));
840 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
842 if (ssh->v1_compressing) {
843 unsigned char *decompblk;
845 zlib_decompress_block(ssh->sc_comp_ctx,
846 ssh->pktin.body - 1, ssh->pktin.length + 1,
847 &decompblk, &decomplen);
849 if (ssh->pktin.maxlen < st->pad + decomplen) {
850 ssh->pktin.maxlen = st->pad + decomplen;
851 ssh->pktin.data = srealloc(ssh->pktin.data,
852 ssh->pktin.maxlen + APIEXTRA);
853 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
856 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
858 ssh->pktin.length = decomplen - 1;
861 ssh->pktin.type = ssh->pktin.body[-1];
864 log_packet(ssh->logctx,
865 PKT_INCOMING, ssh->pktin.type,
866 ssh1_pkt_type(ssh->pktin.type),
867 ssh->pktin.body, ssh->pktin.length);
869 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
870 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
871 ssh->pktin.type == SSH1_MSG_DEBUG ||
872 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
873 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
874 long stringlen = GET_32BIT(ssh->pktin.body);
875 if (stringlen + 4 != ssh->pktin.length) {
876 bombout((ssh,"Received data packet with bogus string length"));
881 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
882 /* log debug message */
884 int stringlen = GET_32BIT(ssh->pktin.body);
885 strcpy(buf, "Remote debug message: ");
888 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
889 buf[8 + stringlen] = '\0';
892 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
897 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
898 /* log reason code in disconnect message */
900 unsigned msglen = GET_32BIT(ssh->pktin.body);
902 strcpy(buf, "Remote sent disconnect: ");
903 nowlen = strlen(buf);
904 if (msglen > sizeof(buf) - nowlen - 1)
905 msglen = sizeof(buf) - nowlen - 1;
906 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
907 buf[nowlen + msglen] = '\0';
908 /* logevent(buf); (this is now done within the bombout macro) */
909 bombout((ssh,"Server sent disconnect message:\n\"%s\"", buf+nowlen));
916 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
918 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
920 crBegin(ssh->ssh2_rdpkt_crstate);
924 ssh->pktin.length = 0;
926 st->cipherblk = ssh->sccipher->blksize;
929 if (st->cipherblk < 8)
932 if (ssh->pktin.maxlen < st->cipherblk) {
933 ssh->pktin.maxlen = st->cipherblk;
934 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
938 * Acquire and decrypt the first block of the packet. This will
939 * contain the length and padding details.
941 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
942 while ((*datalen) == 0)
943 crReturn(st->cipherblk - st->i);
944 ssh->pktin.data[st->i] = *(*data)++;
949 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
950 ssh->pktin.data, st->cipherblk);
953 * Now get the length and padding figures.
955 st->len = GET_32BIT(ssh->pktin.data);
956 st->pad = ssh->pktin.data[4];
959 * _Completely_ silly lengths should be stomped on before they
960 * do us any more damage.
962 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
963 bombout((ssh,"Incoming packet was garbled on decryption"));
968 * This enables us to deduce the payload length.
970 st->payload = st->len - st->pad - 1;
972 ssh->pktin.length = st->payload + 5;
975 * So now we can work out the total packet length.
977 st->packetlen = st->len + 4;
978 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
981 * Adjust memory allocation if packet is too big.
983 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
984 ssh->pktin.maxlen = st->packetlen + st->maclen;
985 ssh->pktin.data = srealloc(ssh->pktin.data,
986 ssh->pktin.maxlen + APIEXTRA);
990 * Read and decrypt the remainder of the packet.
992 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
994 while ((*datalen) == 0)
995 crReturn(st->packetlen + st->maclen - st->i);
996 ssh->pktin.data[st->i] = *(*data)++;
999 /* Decrypt everything _except_ the MAC. */
1001 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1002 ssh->pktin.data + st->cipherblk,
1003 st->packetlen - st->cipherblk);
1009 && !ssh->scmac->verify(ssh->sc_mac_ctx, ssh->pktin.data, st->len + 4,
1010 st->incoming_sequence)) {
1011 bombout((ssh,"Incorrect MAC received on packet"));
1014 st->incoming_sequence++; /* whether or not we MACed */
1017 * Decompress packet payload.
1020 unsigned char *newpayload;
1023 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1024 ssh->pktin.data + 5, ssh->pktin.length - 5,
1025 &newpayload, &newlen)) {
1026 if (ssh->pktin.maxlen < newlen + 5) {
1027 ssh->pktin.maxlen = newlen + 5;
1028 ssh->pktin.data = srealloc(ssh->pktin.data,
1029 ssh->pktin.maxlen + APIEXTRA);
1031 ssh->pktin.length = 5 + newlen;
1032 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1037 ssh->pktin.savedpos = 6;
1038 ssh->pktin.type = ssh->pktin.data[5];
1041 log_packet(ssh->logctx, PKT_INCOMING, ssh->pktin.type,
1042 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1043 ssh->pktin.data+6, ssh->pktin.length-6);
1045 switch (ssh->pktin.type) {
1047 * These packets we must handle instantly.
1049 case SSH2_MSG_DISCONNECT:
1051 /* log reason code in disconnect message */
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 sprintf(buf, "Received disconnect message (%s)",
1058 ssh2_disconnect_reasons[reason]);
1060 sprintf(buf, "Received disconnect message (unknown type %d)",
1064 strcpy(buf, "Disconnection message text: ");
1065 nowlen = strlen(buf);
1066 if (msglen > sizeof(buf) - nowlen - 1)
1067 msglen = sizeof(buf) - nowlen - 1;
1068 memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
1069 buf[nowlen + msglen] = '\0';
1071 bombout((ssh,"Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1073 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1074 ssh2_disconnect_reasons[reason] : "unknown",
1079 case SSH2_MSG_IGNORE:
1081 case SSH2_MSG_DEBUG:
1083 /* log the debug message */
1085 /* int display = ssh->pktin.body[6]; */
1086 int stringlen = GET_32BIT(ssh->pktin.data+7);
1088 strcpy(buf, "Remote debug message: ");
1089 prefix = strlen(buf);
1090 if (stringlen > (int)(sizeof(buf)-prefix-1))
1091 stringlen = sizeof(buf)-prefix-1;
1092 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1093 buf[prefix + stringlen] = '\0';
1096 goto next_packet; /* FIXME: print the debug message */
1099 * These packets we need do nothing about here.
1101 case SSH2_MSG_UNIMPLEMENTED:
1102 case SSH2_MSG_SERVICE_REQUEST:
1103 case SSH2_MSG_SERVICE_ACCEPT:
1104 case SSH2_MSG_KEXINIT:
1105 case SSH2_MSG_NEWKEYS:
1106 case SSH2_MSG_KEXDH_INIT:
1107 case SSH2_MSG_KEXDH_REPLY:
1108 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1109 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1110 case SSH2_MSG_KEX_DH_GEX_INIT:
1111 case SSH2_MSG_KEX_DH_GEX_REPLY:
1112 case SSH2_MSG_USERAUTH_REQUEST:
1113 case SSH2_MSG_USERAUTH_FAILURE:
1114 case SSH2_MSG_USERAUTH_SUCCESS:
1115 case SSH2_MSG_USERAUTH_BANNER:
1116 case SSH2_MSG_USERAUTH_PK_OK:
1117 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1118 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1119 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1120 case SSH2_MSG_GLOBAL_REQUEST:
1121 case SSH2_MSG_REQUEST_SUCCESS:
1122 case SSH2_MSG_REQUEST_FAILURE:
1123 case SSH2_MSG_CHANNEL_OPEN:
1124 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1125 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1126 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1127 case SSH2_MSG_CHANNEL_DATA:
1128 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1129 case SSH2_MSG_CHANNEL_EOF:
1130 case SSH2_MSG_CHANNEL_CLOSE:
1131 case SSH2_MSG_CHANNEL_REQUEST:
1132 case SSH2_MSG_CHANNEL_SUCCESS:
1133 case SSH2_MSG_CHANNEL_FAILURE:
1137 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1140 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1141 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1149 static void ssh1_pktout_size(Ssh ssh, int len)
1153 len += 5; /* type and CRC */
1154 pad = 8 - (len % 8);
1157 ssh->pktout.length = len - 5;
1158 if (ssh->pktout.maxlen < biglen) {
1159 ssh->pktout.maxlen = biglen;
1161 /* Allocate enough buffer space for extra block
1162 * for MS CryptEncrypt() */
1163 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1165 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1168 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1171 static void s_wrpkt_start(Ssh ssh, int type, int len)
1173 ssh1_pktout_size(ssh, len);
1174 ssh->pktout.type = type;
1177 static int s_wrpkt_prepare(Ssh ssh)
1179 int pad, len, biglen, i;
1182 ssh->pktout.body[-1] = ssh->pktout.type;
1185 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.type,
1186 ssh1_pkt_type(ssh->pktout.type),
1187 ssh->pktout.body, ssh->pktout.length);
1189 if (ssh->v1_compressing) {
1190 unsigned char *compblk;
1192 zlib_compress_block(ssh->cs_comp_ctx,
1193 ssh->pktout.body - 1, ssh->pktout.length + 1,
1194 &compblk, &complen);
1195 ssh1_pktout_size(ssh, complen - 1);
1196 memcpy(ssh->pktout.body - 1, compblk, complen);
1200 len = ssh->pktout.length + 5; /* type and CRC */
1201 pad = 8 - (len % 8);
1204 for (i = 0; i < pad; i++)
1205 ssh->pktout.data[i + 4] = random_byte();
1206 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1207 PUT_32BIT(ssh->pktout.data + biglen, crc);
1208 PUT_32BIT(ssh->pktout.data, len);
1211 ssh->cipher->encrypt(ssh->v1_cipher_ctx, ssh->pktout.data + 4, biglen);
1216 static void s_wrpkt(Ssh ssh)
1219 len = s_wrpkt_prepare(ssh);
1220 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1221 if (backlog > SSH_MAX_BACKLOG)
1222 ssh_throttle_all(ssh, 1, backlog);
1225 static void s_wrpkt_defer(Ssh ssh)
1228 len = s_wrpkt_prepare(ssh);
1229 if (ssh->deferred_len + len > ssh->deferred_size) {
1230 ssh->deferred_size = ssh->deferred_len + len + 128;
1231 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1232 ssh->deferred_size);
1234 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1235 ssh->deferred_len += len;
1239 * Construct a packet with the specified contents.
1241 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1243 unsigned char *p, *argp, argchar;
1244 unsigned long argint;
1245 int pktlen, argtype, arglen;
1249 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1252 (void) va_arg(ap1, int);
1256 (void) va_arg(ap1, char);
1260 (void) va_arg(ap1, unsigned char *);
1261 arglen = va_arg(ap1, int);
1265 argp = va_arg(ap1, unsigned char *);
1266 arglen = strlen(argp);
1267 pktlen += 4 + arglen;
1270 bn = va_arg(ap1, Bignum);
1271 pktlen += ssh1_bignum_length(bn);
1278 s_wrpkt_start(ssh, pkttype, pktlen);
1279 p = ssh->pktout.body;
1281 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1284 argint = va_arg(ap2, int);
1285 PUT_32BIT(p, argint);
1289 argchar = va_arg(ap2, unsigned char);
1294 argp = va_arg(ap2, unsigned char *);
1295 arglen = va_arg(ap2, int);
1296 memcpy(p, argp, arglen);
1300 argp = va_arg(ap2, unsigned char *);
1301 arglen = strlen(argp);
1302 PUT_32BIT(p, arglen);
1303 memcpy(p + 4, argp, arglen);
1307 bn = va_arg(ap2, Bignum);
1308 p += ssh1_write_bignum(p, bn);
1314 static void send_packet(Ssh ssh, int pkttype, ...)
1317 va_start(ap1, pkttype);
1318 va_start(ap2, pkttype);
1319 construct_packet(ssh, pkttype, ap1, ap2);
1323 static void defer_packet(Ssh ssh, int pkttype, ...)
1326 va_start(ap1, pkttype);
1327 va_start(ap2, pkttype);
1328 construct_packet(ssh, pkttype, ap1, ap2);
1332 static int ssh_versioncmp(char *a, char *b)
1335 unsigned long av, bv;
1337 av = strtoul(a, &ae, 10);
1338 bv = strtoul(b, &be, 10);
1340 return (av < bv ? -1 : +1);
1345 av = strtoul(ae, &ae, 10);
1346 bv = strtoul(be, &be, 10);
1348 return (av < bv ? -1 : +1);
1353 * Utility routines for putting an SSH-protocol `string' and
1354 * `uint32' into a SHA state.
1357 static void sha_string(SHA_State * s, void *str, int len)
1359 unsigned char lenblk[4];
1360 PUT_32BIT(lenblk, len);
1361 SHA_Bytes(s, lenblk, 4);
1362 SHA_Bytes(s, str, len);
1365 static void sha_uint32(SHA_State * s, unsigned i)
1367 unsigned char intblk[4];
1368 PUT_32BIT(intblk, i);
1369 SHA_Bytes(s, intblk, 4);
1373 * SSH2 packet construction functions.
1375 static void ssh2_pkt_ensure(Ssh ssh, int length)
1377 if (ssh->pktout.maxlen < length) {
1378 ssh->pktout.maxlen = length + 256;
1379 ssh->pktout.data = srealloc(ssh->pktout.data,
1380 ssh->pktout.maxlen + APIEXTRA);
1381 if (!ssh->pktout.data)
1382 fatalbox("Out of memory");
1385 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1387 ssh->pktout.length += len;
1388 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1389 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1391 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1393 ssh2_pkt_adddata(ssh, &byte, 1);
1395 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1397 ssh->pktout.length = 5;
1398 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1400 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1402 ssh2_pkt_adddata(ssh, &value, 1);
1404 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1407 PUT_32BIT(x, value);
1408 ssh2_pkt_adddata(ssh, x, 4);
1410 static void ssh2_pkt_addstring_start(Ssh ssh)
1412 ssh2_pkt_adduint32(ssh, 0);
1413 ssh->pktout.savedpos = ssh->pktout.length;
1415 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1417 ssh2_pkt_adddata(ssh, data, strlen(data));
1418 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1419 ssh->pktout.length - ssh->pktout.savedpos);
1421 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1423 ssh2_pkt_adddata(ssh, data, len);
1424 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1425 ssh->pktout.length - ssh->pktout.savedpos);
1427 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1429 ssh2_pkt_addstring_start(ssh);
1430 ssh2_pkt_addstring_str(ssh, data);
1432 static char *ssh2_mpint_fmt(Bignum b, int *len)
1435 int i, n = (bignum_bitcount(b) + 7) / 8;
1438 fatalbox("out of memory");
1440 for (i = 1; i <= n; i++)
1441 p[i] = bignum_byte(b, n - i);
1443 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1445 memmove(p, p + i, n + 1 - i);
1449 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1453 p = ssh2_mpint_fmt(b, &len);
1454 ssh2_pkt_addstring_start(ssh);
1455 ssh2_pkt_addstring_data(ssh, p, len);
1460 * Construct an SSH2 final-form packet: compress it, encrypt it,
1461 * put the MAC on it. Final packet, ready to be sent, is stored in
1462 * ssh->pktout.data. Total length is returned.
1464 static int ssh2_pkt_construct(Ssh ssh)
1466 int cipherblk, maclen, padding, i;
1469 log_packet(ssh->logctx, PKT_OUTGOING, ssh->pktout.data[5],
1470 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1471 ssh->pktout.data + 6, ssh->pktout.length - 6);
1474 * Compress packet payload.
1477 unsigned char *newpayload;
1480 ssh->cscomp->compress(ssh->cs_comp_ctx, ssh->pktout.data + 5,
1481 ssh->pktout.length - 5,
1482 &newpayload, &newlen)) {
1483 ssh->pktout.length = 5;
1484 ssh2_pkt_adddata(ssh, newpayload, newlen);
1490 * Add padding. At least four bytes, and must also bring total
1491 * length (minus MAC) up to a multiple of the block size.
1493 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1494 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1497 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1498 maclen = ssh->csmac ? ssh->csmac->len : 0;
1499 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1500 ssh->pktout.data[4] = padding;
1501 for (i = 0; i < padding; i++)
1502 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1503 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1505 ssh->csmac->generate(ssh->cs_mac_ctx, ssh->pktout.data,
1506 ssh->pktout.length + padding,
1507 ssh->v2_outgoing_sequence);
1508 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1511 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1512 ssh->pktout.data, ssh->pktout.length + padding);
1514 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1515 return ssh->pktout.length + padding + maclen;
1519 * Construct and send an SSH2 packet immediately.
1521 static void ssh2_pkt_send(Ssh ssh)
1525 len = ssh2_pkt_construct(ssh);
1526 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1527 if (backlog > SSH_MAX_BACKLOG)
1528 ssh_throttle_all(ssh, 1, backlog);
1532 * Construct an SSH2 packet and add it to a deferred data block.
1533 * Useful for sending multiple packets in a single sk_write() call,
1534 * to prevent a traffic-analysing listener from being able to work
1535 * out the length of any particular packet (such as the password
1538 * Note that because SSH2 sequence-numbers its packets, this can
1539 * NOT be used as an m4-style `defer' allowing packets to be
1540 * constructed in one order and sent in another.
1542 static void ssh2_pkt_defer(Ssh ssh)
1544 int len = ssh2_pkt_construct(ssh);
1545 if (ssh->deferred_len + len > ssh->deferred_size) {
1546 ssh->deferred_size = ssh->deferred_len + len + 128;
1547 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1548 ssh->deferred_size);
1550 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1551 ssh->deferred_len += len;
1555 * Send the whole deferred data block constructed by
1556 * ssh2_pkt_defer() or SSH1's defer_packet().
1558 static void ssh_pkt_defersend(Ssh ssh)
1561 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1562 ssh->deferred_len = ssh->deferred_size = 0;
1563 sfree(ssh->deferred_send_data);
1564 ssh->deferred_send_data = NULL;
1565 if (backlog > SSH_MAX_BACKLOG)
1566 ssh_throttle_all(ssh, 1, backlog);
1570 void bndebug(char *string, Bignum b)
1574 p = ssh2_mpint_fmt(b, &len);
1575 debug(("%s", string));
1576 for (i = 0; i < len; i++)
1577 debug((" %02x", p[i]));
1583 static void sha_mpint(SHA_State * s, Bignum b)
1587 p = ssh2_mpint_fmt(b, &len);
1588 sha_string(s, p, len);
1593 * SSH2 packet decode functions.
1595 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1597 unsigned long value;
1598 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1599 return 0; /* arrgh, no way to decline (FIXME?) */
1600 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1601 ssh->pktin.savedpos += 4;
1604 static int ssh2_pkt_getbool(Ssh ssh)
1606 unsigned long value;
1607 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1608 return 0; /* arrgh, no way to decline (FIXME?) */
1609 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1610 ssh->pktin.savedpos++;
1613 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1617 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1619 *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1620 ssh->pktin.savedpos += 4;
1621 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1623 *p = ssh->pktin.data + ssh->pktin.savedpos;
1624 ssh->pktin.savedpos += *length;
1626 static Bignum ssh2_pkt_getmp(Ssh ssh)
1632 ssh2_pkt_getstring(ssh, &p, &length);
1636 bombout((ssh,"internal error: Can't handle negative mpints"));
1639 b = bignum_from_bytes(p, length);
1644 * Helper function to add an SSH2 signature blob to a packet.
1645 * Expects to be shown the public key blob as well as the signature
1646 * blob. Normally works just like ssh2_pkt_addstring, but will
1647 * fiddle with the signature packet if necessary for
1648 * BUG_SSH2_RSA_PADDING.
1650 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1651 void *sigblob_v, int sigblob_len)
1653 unsigned char *pkblob = (unsigned char *)pkblob_v;
1654 unsigned char *sigblob = (unsigned char *)sigblob_v;
1656 /* dmemdump(pkblob, pkblob_len); */
1657 /* dmemdump(sigblob, sigblob_len); */
1660 * See if this is in fact an ssh-rsa signature and a buggy
1661 * server; otherwise we can just do this the easy way.
1663 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1664 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1665 int pos, len, siglen;
1668 * Find the byte length of the modulus.
1671 pos = 4+7; /* skip over "ssh-rsa" */
1672 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1673 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1674 pos += 4; /* find modulus itself */
1675 while (len > 0 && pkblob[pos] == 0)
1677 /* debug(("modulus length is %d\n", len)); */
1680 * Now find the signature integer.
1682 pos = 4+7; /* skip over "ssh-rsa" */
1683 siglen = GET_32BIT(sigblob+pos);
1684 /* debug(("signature length is %d\n", siglen)); */
1686 if (len != siglen) {
1687 unsigned char newlen[4];
1688 ssh2_pkt_addstring_start(ssh);
1689 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1690 /* dmemdump(sigblob, pos); */
1691 pos += 4; /* point to start of actual sig */
1692 PUT_32BIT(newlen, len);
1693 ssh2_pkt_addstring_data(ssh, newlen, 4);
1694 /* dmemdump(newlen, 4); */
1696 while (len-- > siglen) {
1697 ssh2_pkt_addstring_data(ssh, newlen, 1);
1698 /* dmemdump(newlen, 1); */
1700 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1701 /* dmemdump(sigblob+pos, siglen); */
1705 /* Otherwise fall through and do it the easy way. */
1708 ssh2_pkt_addstring_start(ssh);
1709 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1713 * Examine the remote side's version string and compare it against
1714 * a list of known buggy implementations.
1716 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1718 char *imp; /* pointer to implementation part */
1720 imp += strcspn(imp, "-");
1722 imp += strcspn(imp, "-");
1725 ssh->remote_bugs = 0;
1727 if (cfg.sshbug_ignore1 == BUG_ON ||
1728 (cfg.sshbug_ignore1 == BUG_AUTO &&
1729 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1730 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1731 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1733 * These versions don't support SSH1_MSG_IGNORE, so we have
1734 * to use a different defence against password length
1737 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1738 logevent("We believe remote version has SSH1 ignore bug");
1741 if (cfg.sshbug_plainpw1 == BUG_ON ||
1742 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1743 (!strcmp(imp, "Cisco-1.25")))) {
1745 * These versions need a plain password sent; they can't
1746 * handle having a null and a random length of data after
1749 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1750 logevent("We believe remote version needs a plain SSH1 password");
1753 if (cfg.sshbug_rsa1 == BUG_ON ||
1754 (cfg.sshbug_rsa1 == BUG_AUTO &&
1755 (!strcmp(imp, "Cisco-1.25")))) {
1757 * These versions apparently have no clue whatever about
1758 * RSA authentication and will panic and die if they see
1759 * an AUTH_RSA message.
1761 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1762 logevent("We believe remote version can't handle RSA authentication");
1765 if (cfg.sshbug_hmac2 == BUG_ON ||
1766 (cfg.sshbug_hmac2 == BUG_AUTO &&
1767 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1768 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1769 !strncmp(imp, "2.1 ", 4)))) {
1771 * These versions have the HMAC bug.
1773 ssh->remote_bugs |= BUG_SSH2_HMAC;
1774 logevent("We believe remote version has SSH2 HMAC bug");
1777 if (cfg.sshbug_derivekey2 == BUG_ON ||
1778 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1779 (!strncmp(imp, "2.0.", 4)))) {
1781 * These versions have the key-derivation bug (failing to
1782 * include the literal shared secret in the hashes that
1783 * generate the keys).
1785 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1786 logevent("We believe remote version has SSH2 key-derivation bug");
1789 if (cfg.sshbug_rsapad2 == BUG_ON ||
1790 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1791 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1792 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1794 * These versions have the SSH2 RSA padding bug.
1796 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1797 logevent("We believe remote version has SSH2 RSA padding bug");
1800 if (cfg.sshbug_dhgex2 == BUG_ON) {
1802 * These versions have the SSH2 DH GEX bug.
1804 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1805 logevent("We believe remote version has SSH2 DH group exchange bug");
1809 static int do_ssh_init(Ssh ssh, unsigned char c)
1811 struct do_ssh_init_state {
1819 crState(do_ssh_init_state);
1821 crBegin(ssh->do_ssh_init_crstate);
1823 /* Search for the string "SSH-" in the input. */
1826 static const int transS[] = { 1, 2, 2, 1 };
1827 static const int transH[] = { 0, 0, 3, 0 };
1828 static const int transminus[] = { 0, 0, 0, -1 };
1830 s->i = transS[s->i];
1832 s->i = transH[s->i];
1834 s->i = transminus[s->i];
1839 crReturn(1); /* get another character */
1843 s->vstring = smalloc(s->vstrsize);
1844 strcpy(s->vstring, "SSH-");
1848 crReturn(1); /* get another char */
1849 if (s->vslen >= s->vstrsize - 1) {
1851 s->vstring = srealloc(s->vstring, s->vstrsize);
1853 s->vstring[s->vslen++] = c;
1856 s->version[s->i] = '\0';
1858 } else if (s->i < sizeof(s->version) - 1)
1859 s->version[s->i++] = c;
1860 } else if (c == '\n')
1864 ssh->agentfwd_enabled = FALSE;
1865 ssh->rdpkt2_state.incoming_sequence = 0;
1867 s->vstring[s->vslen] = 0;
1868 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1871 vlog = smalloc(20 + s->vslen);
1872 sprintf(vlog, "Server version: %s", s->vstring);
1876 ssh_detect_bugs(ssh, s->vstring);
1879 * Decide which SSH protocol version to support.
1882 /* Anything strictly below "2.0" means protocol 1 is supported. */
1883 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1884 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1885 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1887 if (cfg.sshprot == 0 && !s->proto1) {
1888 bombout((ssh,"SSH protocol version 1 required by user but not provided by server"));
1891 if (cfg.sshprot == 3 && !s->proto2) {
1892 bombout((ssh,"SSH protocol version 2 required by user but not provided by server"));
1896 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1900 char verstring[80], vlog[100];
1901 sprintf(verstring, "SSH-2.0-%s", sshver);
1902 SHA_Init(&ssh->exhashbase);
1904 * Hash our version string and their version string.
1906 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1907 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1908 sprintf(vlog, "We claim version: %s", verstring);
1910 strcat(verstring, "\n");
1911 logevent("Using SSH protocol version 2");
1912 sk_write(ssh->s, verstring, strlen(verstring));
1913 ssh->protocol = ssh2_protocol;
1915 ssh->s_rdpkt = ssh2_rdpkt;
1920 char verstring[80], vlog[100];
1921 sprintf(verstring, "SSH-%s-%s",
1922 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1924 sprintf(vlog, "We claim version: %s", verstring);
1926 strcat(verstring, "\n");
1928 logevent("Using SSH protocol version 1");
1929 sk_write(ssh->s, verstring, strlen(verstring));
1930 ssh->protocol = ssh1_protocol;
1932 ssh->s_rdpkt = ssh1_rdpkt;
1934 ssh->state = SSH_STATE_BEFORE_SIZE;
1941 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1943 crBegin(ssh->ssh_gotdata_crstate);
1946 * To begin with, feed the characters one by one to the
1947 * protocol initialisation / selection function do_ssh_init().
1948 * When that returns 0, we're done with the initial greeting
1949 * exchange and can move on to packet discipline.
1952 int ret; /* need not be kept across crReturn */
1954 crReturnV; /* more data please */
1955 ret = do_ssh_init(ssh, *data);
1963 * We emerge from that loop when the initial negotiation is
1964 * over and we have selected an s_rdpkt function. Now pass
1965 * everything to s_rdpkt, and then pass the resulting packets
1966 * to the proper protocol handler.
1971 while (datalen > 0) {
1972 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1973 if (ssh->state == SSH_STATE_CLOSED) {
1976 ssh->protocol(ssh, NULL, 0, 1);
1977 if (ssh->state == SSH_STATE_CLOSED) {
1987 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1990 Ssh ssh = (Ssh) plug;
1991 ssh->state = SSH_STATE_CLOSED;
1997 /* A socket error has occurred. */
1998 logevent(error_msg);
1999 connection_fatal(ssh->frontend, error_msg);
2001 /* Otherwise, the remote side closed the connection normally. */
2006 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2008 Ssh ssh = (Ssh) plug;
2009 ssh_gotdata(ssh, data, len);
2010 if (ssh->state == SSH_STATE_CLOSED) {
2020 static void ssh_sent(Plug plug, int bufsize)
2022 Ssh ssh = (Ssh) plug;
2024 * If the send backlog on the SSH socket itself clears, we
2025 * should unthrottle the whole world if it was throttled.
2027 if (bufsize < SSH_MAX_BACKLOG)
2028 ssh_throttle_all(ssh, 0, bufsize);
2032 * Connect to specified host and port.
2033 * Returns an error message, or NULL on success.
2034 * Also places the canonical host name into `realhost'. It must be
2035 * freed by the caller.
2037 static char *connect_to_host(Ssh ssh, char *host, int port,
2038 char **realhost, int nodelay)
2040 static const struct plug_function_table fn_table = {
2050 ssh->savedhost = smalloc(1 + strlen(host));
2051 if (!ssh->savedhost)
2052 fatalbox("Out of memory");
2053 strcpy(ssh->savedhost, host);
2056 port = 22; /* default ssh port */
2057 ssh->savedport = port;
2064 sprintf(buf, "Looking up host \"%.170s\"", host);
2067 addr = sk_namelookup(host, realhost);
2068 if ((err = sk_addr_error(addr)))
2075 char buf[200], addrbuf[100];
2076 sk_getaddr(addr, addrbuf, 100);
2077 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2080 ssh->fn = &fn_table;
2081 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2082 if ((err = sk_socket_error(ssh->s))) {
2091 * Throttle or unthrottle the SSH connection.
2093 static void ssh1_throttle(Ssh ssh, int adjust)
2095 int old_count = ssh->v1_throttle_count;
2096 ssh->v1_throttle_count += adjust;
2097 assert(ssh->v1_throttle_count >= 0);
2098 if (ssh->v1_throttle_count && !old_count) {
2099 sk_set_frozen(ssh->s, 1);
2100 } else if (!ssh->v1_throttle_count && old_count) {
2101 sk_set_frozen(ssh->s, 0);
2106 * Throttle or unthrottle _all_ local data streams (for when sends
2107 * on the SSH connection itself back up).
2109 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2112 struct ssh_channel *c;
2114 if (enable == ssh->throttled_all)
2116 ssh->throttled_all = enable;
2117 ssh->overall_bufsize = bufsize;
2120 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2122 case CHAN_MAINSESSION:
2124 * This is treated separately, outside the switch.
2128 x11_override_throttle(c->u.x11.s, enable);
2131 /* Agent channels require no buffer management. */
2134 pfd_override_throttle(c->u.x11.s, enable);
2141 * Username and password input, abstracted off into routines
2142 * reusable in several places - even between SSH1 and SSH2.
2145 /* Set up a username or password input loop on a given buffer. */
2146 void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2148 ssh->userpass_input_buffer = buffer;
2149 ssh->userpass_input_buflen = buflen;
2150 ssh->userpass_input_bufpos = 0;
2151 ssh->userpass_input_echo = echo;
2155 * Process some terminal data in the course of username/password
2156 * input. Returns >0 for success (line of input returned in
2157 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2158 * for inconclusive (keep waiting for more input please).
2160 int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2165 switch (c = *in++) {
2168 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2169 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2174 if (ssh->userpass_input_bufpos > 0) {
2175 if (ssh->userpass_input_echo)
2176 c_write_str(ssh, "\b \b");
2177 ssh->userpass_input_bufpos--;
2182 while (ssh->userpass_input_bufpos > 0) {
2183 if (ssh->userpass_input_echo)
2184 c_write_str(ssh, "\b \b");
2185 ssh->userpass_input_bufpos--;
2193 if (((c >= ' ' && c <= '~') ||
2194 ((unsigned char) c >= 160))
2195 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2196 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2197 if (ssh->userpass_input_echo)
2198 c_write(ssh, &c, 1);
2207 * Handle the key exchange and user authentication phases.
2209 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2212 unsigned char cookie[8];
2213 struct RSAKey servkey, hostkey;
2214 struct MD5Context md5c;
2215 struct do_ssh1_login_state {
2217 unsigned char *rsabuf, *keystr1, *keystr2;
2218 unsigned long supported_ciphers_mask, supported_auths_mask;
2219 int tried_publickey, tried_agent;
2220 int tis_auth_refused, ccard_auth_refused;
2221 unsigned char session_id[16];
2224 void *publickey_blob;
2225 int publickey_bloblen;
2231 unsigned char request[5], *response, *p;
2240 crState(do_ssh1_login_state);
2242 crBegin(ssh->do_ssh1_login_crstate);
2247 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2248 bombout((ssh,"Public key packet not received"));
2252 logevent("Received public keys");
2254 memcpy(cookie, ssh->pktin.body, 8);
2256 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2257 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2260 * Log the host key fingerprint.
2264 logevent("Host key fingerprint is:");
2265 strcpy(logmsg, " ");
2266 hostkey.comment = NULL;
2267 rsa_fingerprint(logmsg + strlen(logmsg),
2268 sizeof(logmsg) - strlen(logmsg), &hostkey);
2272 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2273 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2274 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2276 ssh->v1_local_protoflags =
2277 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2278 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2281 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2282 MD5Update(&md5c, s->keystr1, servkey.bytes);
2283 MD5Update(&md5c, ssh->pktin.body, 8);
2284 MD5Final(s->session_id, &md5c);
2286 for (i = 0; i < 32; i++)
2287 ssh->session_key[i] = random_byte();
2289 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2291 s->rsabuf = smalloc(s->len);
2293 fatalbox("Out of memory");
2296 * Verify the host key.
2300 * First format the key into a string.
2302 int len = rsastr_len(&hostkey);
2303 char fingerprint[100];
2304 char *keystr = smalloc(len);
2306 fatalbox("Out of memory");
2307 rsastr_fmt(keystr, &hostkey);
2308 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2309 verify_ssh_host_key(ssh->frontend,
2310 ssh->savedhost, ssh->savedport, "rsa", keystr,
2315 for (i = 0; i < 32; i++) {
2316 s->rsabuf[i] = ssh->session_key[i];
2318 s->rsabuf[i] ^= s->session_id[i];
2321 if (hostkey.bytes > servkey.bytes) {
2322 rsaencrypt(s->rsabuf, 32, &servkey);
2323 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2325 rsaencrypt(s->rsabuf, 32, &hostkey);
2326 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2329 logevent("Encrypted session key");
2332 int cipher_chosen = 0, warn = 0;
2333 char *cipher_string = NULL;
2335 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2336 int next_cipher = cfg.ssh_cipherlist[i];
2337 if (next_cipher == CIPHER_WARN) {
2338 /* If/when we choose a cipher, warn about it */
2340 } else if (next_cipher == CIPHER_AES) {
2341 /* XXX Probably don't need to mention this. */
2342 logevent("AES not supported in SSH1, skipping");
2344 switch (next_cipher) {
2345 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2346 cipher_string = "3DES"; break;
2347 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2348 cipher_string = "Blowfish"; break;
2349 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2350 cipher_string = "single-DES"; break;
2352 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2356 if (!cipher_chosen) {
2357 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2358 bombout((ssh,"Server violates SSH 1 protocol by not "
2359 "supporting 3DES encryption"));
2361 /* shouldn't happen */
2362 bombout((ssh,"No supported ciphers found"));
2366 /* Warn about chosen cipher if necessary. */
2368 askcipher(ssh->frontend, cipher_string, 0);
2371 switch (s->cipher_type) {
2372 case SSH_CIPHER_3DES:
2373 logevent("Using 3DES encryption");
2375 case SSH_CIPHER_DES:
2376 logevent("Using single-DES encryption");
2378 case SSH_CIPHER_BLOWFISH:
2379 logevent("Using Blowfish encryption");
2383 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2384 PKT_CHAR, s->cipher_type,
2385 PKT_DATA, cookie, 8,
2386 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2387 PKT_DATA, s->rsabuf, s->len,
2388 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2390 logevent("Trying to enable encryption...");
2394 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2395 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2397 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2398 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2401 sprintf(buf, "Initialised %.200s encryption", ssh->cipher->text_name);
2405 ssh->crcda_ctx = crcda_make_context();
2406 logevent("Installing CRC compensation attack detector");
2410 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2411 bombout((ssh,"Encryption not successfully enabled"));
2415 logevent("Successfully started encryption");
2419 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2420 if (ssh_get_line && !ssh_getline_pw_only) {
2421 if (!ssh_get_line("login as: ",
2422 s->username, sizeof(s->username), FALSE)) {
2424 * get_line failed to get a username.
2427 logevent("No username provided. Abandoning session.");
2428 ssh->state = SSH_STATE_CLOSED;
2432 int ret; /* need not be kept over crReturn */
2433 c_write_str(ssh, "login as: ");
2436 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2438 crWaitUntil(!ispkt);
2439 ret = process_userpass_input(ssh, in, inlen);
2443 c_write_str(ssh, "\r\n");
2446 strncpy(s->username, cfg.username, sizeof(s->username));
2447 s->username[sizeof(s->username)-1] = '\0';
2450 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2452 char userlog[22 + sizeof(s->username)];
2453 sprintf(userlog, "Sent username \"%s\"", s->username);
2455 if (flags & FLAG_INTERACTIVE &&
2456 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2457 strcat(userlog, "\r\n");
2458 c_write_str(ssh, userlog);
2465 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2466 /* We must not attempt PK auth. Pretend we've already tried it. */
2467 s->tried_publickey = s->tried_agent = 1;
2469 s->tried_publickey = s->tried_agent = 0;
2471 s->tis_auth_refused = s->ccard_auth_refused = 0;
2472 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2474 if (!rsakey_pubblob(cfg.keyfile,
2475 &s->publickey_blob, &s->publickey_bloblen))
2476 s->publickey_blob = NULL;
2478 s->publickey_blob = NULL;
2480 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2481 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2483 if (agent_exists() && !s->tried_agent) {
2485 * Attempt RSA authentication using Pageant.
2491 logevent("Pageant is running. Requesting keys.");
2493 /* Request the keys held by the agent. */
2494 PUT_32BIT(s->request, 1);
2495 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2496 agent_query(s->request, 5, &r, &s->responselen);
2497 s->response = (unsigned char *) r;
2498 if (s->response && s->responselen >= 5 &&
2499 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2500 s->p = s->response + 5;
2501 s->nkeys = GET_32BIT(s->p);
2505 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2508 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2511 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2514 if (s->publickey_blob &&
2515 !memcmp(s->p, s->publickey_blob,
2516 s->publickey_bloblen)) {
2517 logevent("This key matches configured key file");
2518 s->tried_publickey = 1;
2521 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2522 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2523 s->commentlen = GET_32BIT(s->p);
2526 s->p += s->commentlen;
2527 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2528 PKT_BIGNUM, s->key.modulus, PKT_END);
2530 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2531 logevent("Key refused");
2534 logevent("Received RSA challenge");
2535 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2537 char *agentreq, *q, *ret;
2540 len = 1 + 4; /* message type, bit count */
2541 len += ssh1_bignum_length(s->key.exponent);
2542 len += ssh1_bignum_length(s->key.modulus);
2543 len += ssh1_bignum_length(s->challenge);
2544 len += 16; /* session id */
2545 len += 4; /* response format */
2546 agentreq = smalloc(4 + len);
2547 PUT_32BIT(agentreq, len);
2549 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2550 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2552 q += ssh1_write_bignum(q, s->key.exponent);
2553 q += ssh1_write_bignum(q, s->key.modulus);
2554 q += ssh1_write_bignum(q, s->challenge);
2555 memcpy(q, s->session_id, 16);
2557 PUT_32BIT(q, 1); /* response format */
2558 agent_query(agentreq, len + 4, &vret, &retlen);
2562 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2563 logevent("Sending Pageant's response");
2564 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2565 PKT_DATA, ret + 5, 16,
2569 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2571 ("Pageant's response accepted");
2572 if (flags & FLAG_VERBOSE) {
2573 c_write_str(ssh, "Authenticated using"
2575 c_write(ssh, s->commentp,
2577 c_write_str(ssh, "\" from agent\r\n");
2582 ("Pageant's response not accepted");
2585 ("Pageant failed to answer challenge");
2589 logevent("No reply received from Pageant");
2592 freebn(s->key.exponent);
2593 freebn(s->key.modulus);
2594 freebn(s->challenge);
2602 if (*cfg.keyfile && !s->tried_publickey)
2603 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2605 if (cfg.try_tis_auth &&
2606 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2607 !s->tis_auth_refused) {
2608 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2609 logevent("Requested TIS authentication");
2610 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2612 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2613 logevent("TIS authentication declined");
2614 if (flags & FLAG_INTERACTIVE)
2615 c_write_str(ssh, "TIS authentication refused.\r\n");
2616 s->tis_auth_refused = 1;
2619 int challengelen = GET_32BIT(ssh->pktin.body);
2620 logevent("Received TIS challenge");
2621 if (challengelen > sizeof(s->prompt) - 1)
2622 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2623 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2624 /* Prompt heuristic comes from OpenSSH */
2625 strncpy(s->prompt + challengelen,
2626 memchr(s->prompt, '\n', challengelen) ?
2627 "": "\r\nResponse: ",
2628 (sizeof s->prompt) - challengelen);
2629 s->prompt[(sizeof s->prompt) - 1] = '\0';
2632 if (cfg.try_tis_auth &&
2633 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2634 !s->ccard_auth_refused) {
2635 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2636 logevent("Requested CryptoCard authentication");
2637 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2639 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2640 logevent("CryptoCard authentication declined");
2641 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2642 s->ccard_auth_refused = 1;
2645 int challengelen = GET_32BIT(ssh->pktin.body);
2646 logevent("Received CryptoCard challenge");
2647 if (challengelen > sizeof(s->prompt) - 1)
2648 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2649 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2650 strncpy(s->prompt + challengelen,
2651 memchr(s->prompt, '\n', challengelen) ?
2652 "" : "\r\nResponse: ",
2653 sizeof(s->prompt) - challengelen);
2654 s->prompt[sizeof(s->prompt) - 1] = '\0';
2657 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2658 sprintf(s->prompt, "%.90s@%.90s's password: ",
2659 s->username, ssh->savedhost);
2661 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2662 char *comment = NULL;
2665 if (flags & FLAG_VERBOSE)
2666 c_write_str(ssh, "Trying public key authentication.\r\n");
2667 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2669 type = key_type(cfg.keyfile);
2670 if (type != SSH_KEYTYPE_SSH1) {
2671 sprintf(msgbuf, "Key is of wrong type (%s)",
2672 key_type_to_str(type));
2674 c_write_str(ssh, msgbuf);
2675 c_write_str(ssh, "\r\n");
2676 s->tried_publickey = 1;
2679 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2680 if (flags & FLAG_VERBOSE)
2681 c_write_str(ssh, "No passphrase required.\r\n");
2684 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2689 * Show password prompt, having first obtained it via a TIS
2690 * or CryptoCard exchange if we're doing TIS or CryptoCard
2694 if (!ssh_get_line(s->prompt, s->password,
2695 sizeof(s->password), TRUE)) {
2697 * get_line failed to get a password (for example
2698 * because one was supplied on the command line
2699 * which has already failed to work). Terminate.
2701 send_packet(ssh, SSH1_MSG_DISCONNECT,
2702 PKT_STR, "No more passwords available to try",
2704 logevent("Unable to authenticate");
2705 connection_fatal(ssh->frontend, "Unable to authenticate");
2706 ssh->state = SSH_STATE_CLOSED;
2710 /* Prompt may have come from server. We've munged it a bit, so
2711 * we know it to be zero-terminated at least once. */
2712 int ret; /* need not be saved over crReturn */
2713 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2716 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2718 crWaitUntil(!ispkt);
2719 ret = process_userpass_input(ssh, in, inlen);
2723 c_write_str(ssh, "\r\n");
2727 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2729 * Try public key authentication with the specified
2732 s->tried_publickey = 1;
2735 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2737 c_write_str(ssh, "Couldn't load private key from ");
2738 c_write_str(ssh, cfg.keyfile);
2739 c_write_str(ssh, ".\r\n");
2740 continue; /* go and try password */
2743 c_write_str(ssh, "Wrong passphrase.\r\n");
2744 s->tried_publickey = 0;
2745 continue; /* try again */
2750 * Send a public key attempt.
2752 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2753 PKT_BIGNUM, s->key.modulus, PKT_END);
2756 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2757 c_write_str(ssh, "Server refused our public key.\r\n");
2758 continue; /* go and try password */
2760 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2761 bombout((ssh,"Bizarre response to offer of public key"));
2767 unsigned char buffer[32];
2768 Bignum challenge, response;
2770 ssh1_read_bignum(ssh->pktin.body, &challenge);
2771 response = rsadecrypt(challenge, &s->key);
2772 freebn(s->key.private_exponent);/* burn the evidence */
2774 for (i = 0; i < 32; i++) {
2775 buffer[i] = bignum_byte(response, 31 - i);
2779 MD5Update(&md5c, buffer, 32);
2780 MD5Update(&md5c, s->session_id, 16);
2781 MD5Final(buffer, &md5c);
2783 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2784 PKT_DATA, buffer, 16, PKT_END);
2791 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2792 if (flags & FLAG_VERBOSE)
2793 c_write_str(ssh, "Failed to authenticate with"
2794 " our public key.\r\n");
2795 continue; /* go and try password */
2796 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2797 bombout((ssh,"Bizarre response to RSA authentication response"));
2801 break; /* we're through! */
2803 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2805 * Defence against traffic analysis: we send a
2806 * whole bunch of packets containing strings of
2807 * different lengths. One of these strings is the
2808 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2809 * The others are all random data in
2810 * SSH1_MSG_IGNORE packets. This way a passive
2811 * listener can't tell which is the password, and
2812 * hence can't deduce the password length.
2814 * Anybody with a password length greater than 16
2815 * bytes is going to have enough entropy in their
2816 * password that a listener won't find it _that_
2817 * much help to know how long it is. So what we'll
2820 * - if password length < 16, we send 15 packets
2821 * containing string lengths 1 through 15
2823 * - otherwise, we let N be the nearest multiple
2824 * of 8 below the password length, and send 8
2825 * packets containing string lengths N through
2826 * N+7. This won't obscure the order of
2827 * magnitude of the password length, but it will
2828 * introduce a bit of extra uncertainty.
2830 * A few servers (the old 1.2.18 through 1.2.22)
2831 * can't deal with SSH1_MSG_IGNORE. For these
2832 * servers, we need an alternative defence. We make
2833 * use of the fact that the password is interpreted
2834 * as a C string: so we can append a NUL, then some
2837 * One server (a Cisco one) can deal with neither
2838 * SSH1_MSG_IGNORE _nor_ a padded password string.
2839 * For this server we are left with no defences
2840 * against password length sniffing.
2842 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2844 * The server can deal with SSH1_MSG_IGNORE, so
2845 * we can use the primary defence.
2847 int bottom, top, pwlen, i;
2850 pwlen = strlen(s->password);
2852 bottom = 0; /* zero length passwords are OK! :-) */
2855 bottom = pwlen & ~7;
2859 assert(pwlen >= bottom && pwlen <= top);
2861 randomstr = smalloc(top + 1);
2863 for (i = bottom; i <= top; i++) {
2865 defer_packet(ssh, s->pwpkt_type,
2866 PKT_STR, s->password, PKT_END);
2868 for (j = 0; j < i; j++) {
2870 randomstr[j] = random_byte();
2871 } while (randomstr[j] == '\0');
2873 randomstr[i] = '\0';
2874 defer_packet(ssh, SSH1_MSG_IGNORE,
2875 PKT_STR, randomstr, PKT_END);
2878 logevent("Sending password with camouflage packets");
2879 ssh_pkt_defersend(ssh);
2881 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2883 * The server can't deal with SSH1_MSG_IGNORE
2884 * but can deal with padded passwords, so we
2885 * can use the secondary defence.
2891 len = strlen(s->password);
2892 if (len < sizeof(string)) {
2894 strcpy(string, s->password);
2895 len++; /* cover the zero byte */
2896 while (len < sizeof(string)) {
2897 string[len++] = (char) random_byte();
2902 logevent("Sending length-padded password");
2903 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2904 PKT_DATA, ss, len, PKT_END);
2907 * The server has _both_
2908 * BUG_CHOKES_ON_SSH1_IGNORE and
2909 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2910 * therefore nothing we can do.
2913 len = strlen(s->password);
2914 logevent("Sending unpadded password");
2915 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2916 PKT_DATA, s->password, len, PKT_END);
2919 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2922 logevent("Sent password");
2923 memset(s->password, 0, strlen(s->password));
2925 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2926 if (flags & FLAG_VERBOSE)
2927 c_write_str(ssh, "Access denied\r\n");
2928 logevent("Authentication refused");
2929 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2930 bombout((ssh,"Strange packet received, type %d", ssh->pktin.type));
2935 logevent("Authentication successful");
2940 void sshfwd_close(struct ssh_channel *c)
2944 if (c && !c->closes) {
2946 * If the channel's remoteid is -1, we have sent
2947 * CHANNEL_OPEN for this channel, but it hasn't even been
2948 * acknowledged by the server. So we must set a close flag
2949 * on it now, and then when the server acks the channel
2950 * open, we can close it then.
2952 if (((int)c->remoteid) != -1) {
2953 if (ssh->version == 1) {
2954 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2957 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2958 ssh2_pkt_adduint32(ssh, c->remoteid);
2962 c->closes = 1; /* sent MSG_CLOSE */
2963 if (c->type == CHAN_X11) {
2965 logevent("Forwarded X11 connection terminated");
2966 } else if (c->type == CHAN_SOCKDATA ||
2967 c->type == CHAN_SOCKDATA_DORMANT) {
2969 logevent("Forwarded port closed");
2974 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2978 if (ssh->version == 1) {
2979 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2980 PKT_INT, c->remoteid,
2981 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2983 * In SSH1 we can return 0 here - implying that forwarded
2984 * connections are never individually throttled - because
2985 * the only circumstance that can cause throttling will be
2986 * the whole SSH connection backing up, in which case
2987 * _everything_ will be throttled as a whole.
2991 ssh2_add_channel_data(c, buf, len);
2992 return ssh2_try_send(c);
2996 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3000 if (ssh->version == 1) {
3001 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3002 c->v.v1.throttling = 0;
3003 ssh1_throttle(ssh, -1);
3006 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3010 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3012 crBegin(ssh->ssh1_protocol_crstate);
3016 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
3019 if (ssh->state == SSH_STATE_CLOSED)
3022 if (cfg.agentfwd && agent_exists()) {
3023 logevent("Requesting agent forwarding");
3024 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
3028 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3029 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3030 bombout((ssh,"Protocol confusion"));
3032 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3033 logevent("Agent forwarding refused");
3035 logevent("Agent forwarding enabled");
3036 ssh->agentfwd_enabled = TRUE;
3040 if (cfg.x11_forward) {
3041 char proto[20], data[64];
3042 logevent("Requesting X11 forwarding");
3043 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
3044 data, sizeof(data));
3045 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
3046 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3047 PKT_STR, proto, PKT_STR, data,
3048 PKT_INT, 0, PKT_END);
3050 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3051 PKT_STR, proto, PKT_STR, data, PKT_END);
3056 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3057 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3058 bombout((ssh,"Protocol confusion"));
3060 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3061 logevent("X11 forwarding refused");
3063 logevent("X11 forwarding enabled");
3064 ssh->X11_fwd_enabled = TRUE;
3071 int sport,dport,sserv,dserv;
3072 char sports[256], dports[256], host[256];
3076 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3077 /* Add port forwardings. */
3078 ssh->portfwd_strptr = cfg.portfwd;
3079 while (*ssh->portfwd_strptr) {
3080 type = *ssh->portfwd_strptr++;
3082 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3083 sports[n++] = *ssh->portfwd_strptr++;
3085 if (*ssh->portfwd_strptr == '\t')
3086 ssh->portfwd_strptr++;
3088 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3089 host[n++] = *ssh->portfwd_strptr++;
3091 if (*ssh->portfwd_strptr == ':')
3092 ssh->portfwd_strptr++;
3094 while (*ssh->portfwd_strptr)
3095 dports[n++] = *ssh->portfwd_strptr++;
3097 ssh->portfwd_strptr++;
3098 dport = atoi(dports);
3102 se = getservbyname(dports, NULL);
3104 dport = ntohs(se->s_port);
3107 "Service lookup failed for destination port \"%s\"",
3112 sport = atoi(sports);
3116 se = getservbyname(sports, NULL);
3118 sport = ntohs(se->s_port);
3121 "Service lookup failed for source port \"%s\"",
3126 if (sport && dport) {
3128 pfd_addforward(host, dport, sport, ssh);
3129 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3130 " %s:%.*s%.*s%d%.*s",
3131 sserv ? strlen(sports) : 0, sports,
3132 sserv, "(", sport, sserv, ")",
3134 dserv ? strlen(dports) : 0, dports,
3135 dserv, "(", dport, dserv, ")");
3138 struct ssh_rportfwd *pf;
3139 pf = smalloc(sizeof(*pf));
3140 strcpy(pf->dhost, host);
3142 if (add234(ssh->rportfwds, pf) != pf) {
3144 "Duplicate remote port forwarding to %s:%d",
3149 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3150 " forward to %s:%.*s%.*s%d%.*s",
3151 sserv ? strlen(sports) : 0, sports,
3152 sserv, "(", sport, sserv, ")",
3154 dserv ? strlen(dports) : 0, dports,
3155 dserv, "(", dport, dserv, ")");
3157 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3165 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3166 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3167 bombout((ssh,"Protocol confusion"));
3169 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3170 c_write_str(ssh, "Server refused port"
3173 logevent("Remote port forwarding enabled");
3181 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3182 PKT_STR, cfg.termtype,
3183 PKT_INT, ssh->term_height,
3184 PKT_INT, ssh->term_width,
3185 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3186 ssh->state = SSH_STATE_INTERMED;
3190 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3191 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3192 bombout((ssh,"Protocol confusion"));
3194 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3195 c_write_str(ssh, "Server refused to allocate pty\r\n");
3196 ssh->editing = ssh->echoing = 1;
3198 logevent("Allocated pty");
3200 ssh->editing = ssh->echoing = 1;
3203 if (cfg.compression) {
3204 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3208 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3209 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3210 bombout((ssh,"Protocol confusion"));
3212 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3213 c_write_str(ssh, "Server refused to compress\r\n");
3215 logevent("Started compression");
3216 ssh->v1_compressing = TRUE;
3217 ssh->cs_comp_ctx = zlib_compress_init();
3218 logevent("Initialised zlib (RFC1950) compression");
3219 ssh->sc_comp_ctx = zlib_decompress_init();
3220 logevent("Initialised zlib (RFC1950) decompression");
3224 * Start the shell or command.
3226 * Special case: if the first-choice command is an SSH2
3227 * subsystem (hence not usable here) and the second choice
3228 * exists, we fall straight back to that.
3231 char *cmd = cfg.remote_cmd_ptr;
3233 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3234 cmd = cfg.remote_cmd_ptr2;
3235 ssh->fallback_cmd = TRUE;
3238 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3240 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3241 logevent("Started session");
3244 ssh->state = SSH_STATE_SESSION;
3245 if (ssh->size_needed)
3246 ssh_size(ssh, ssh->term_width, ssh->term_height);
3247 if (ssh->eof_needed)
3248 ssh_special(ssh, TS_EOF);
3251 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
3253 ssh->channels = newtree234(ssh_channelcmp);
3257 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3258 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3259 long len = GET_32BIT(ssh->pktin.body);
3261 from_backend(ssh->frontend,
3262 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3263 ssh->pktin.body + 4, len);
3264 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3265 ssh->v1_stdout_throttling = 1;
3266 ssh1_throttle(ssh, +1);
3268 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3269 ssh->state = SSH_STATE_CLOSED;
3270 logevent("Received disconnect request");
3272 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3273 /* Remote side is trying to open a channel to talk to our
3274 * X-Server. Give them back a local channel number. */
3275 struct ssh_channel *c;
3277 logevent("Received X11 connect request");
3278 /* Refuse if X11 forwarding is disabled. */
3279 if (!ssh->X11_fwd_enabled) {
3280 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3281 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3282 logevent("Rejected X11 connect request");
3284 c = smalloc(sizeof(struct ssh_channel));
3287 if (x11_init(&c->u.x11.s, cfg.x11_display, c,
3288 ssh->x11auth) != NULL) {
3289 logevent("opening X11 forward connection failed");
3291 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3292 PKT_INT, GET_32BIT(ssh->pktin.body),
3296 ("opening X11 forward connection succeeded");
3297 c->remoteid = GET_32BIT(ssh->pktin.body);
3298 c->localid = alloc_channel_id(ssh);
3300 c->v.v1.throttling = 0;
3301 c->type = CHAN_X11; /* identify channel type */
3302 add234(ssh->channels, c);
3303 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3304 PKT_INT, c->remoteid, PKT_INT,
3305 c->localid, PKT_END);
3306 logevent("Opened X11 forward channel");
3309 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3310 /* Remote side is trying to open a channel to talk to our
3311 * agent. Give them back a local channel number. */
3312 struct ssh_channel *c;
3314 /* Refuse if agent forwarding is disabled. */
3315 if (!ssh->agentfwd_enabled) {
3316 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3317 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3319 c = smalloc(sizeof(struct ssh_channel));
3321 c->remoteid = GET_32BIT(ssh->pktin.body);
3322 c->localid = alloc_channel_id(ssh);
3324 c->v.v1.throttling = 0;
3325 c->type = CHAN_AGENT; /* identify channel type */
3326 c->u.a.lensofar = 0;
3327 add234(ssh->channels, c);
3328 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3329 PKT_INT, c->remoteid, PKT_INT, c->localid,
3332 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3333 /* Remote side is trying to open a channel to talk to a
3334 * forwarded port. Give them back a local channel number. */
3335 struct ssh_channel *c;
3336 struct ssh_rportfwd pf;
3338 char host[256], buf[1024];
3340 c = smalloc(sizeof(struct ssh_channel));
3343 hostsize = GET_32BIT(ssh->pktin.body+4);
3344 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
3345 if (h+1 < host+sizeof(host))
3350 port = GET_32BIT(p);
3352 strcpy(pf.dhost, host);
3355 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3356 sprintf(buf, "Rejected remote port open request for %s:%d",
3359 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3360 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3362 sprintf(buf, "Received remote port open request for %s:%d",
3365 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3368 sprintf(buf, "Port open failed: %s", e);
3371 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3372 PKT_INT, GET_32BIT(ssh->pktin.body),
3375 c->remoteid = GET_32BIT(ssh->pktin.body);
3376 c->localid = alloc_channel_id(ssh);
3378 c->v.v1.throttling = 0;
3379 c->type = CHAN_SOCKDATA; /* identify channel type */
3380 add234(ssh->channels, c);
3381 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3382 PKT_INT, c->remoteid, PKT_INT,
3383 c->localid, PKT_END);
3384 logevent("Forwarded port opened successfully");
3388 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3389 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3390 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3391 struct ssh_channel *c;
3393 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3394 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3395 c->remoteid = localid;
3396 c->type = CHAN_SOCKDATA;
3397 c->v.v1.throttling = 0;
3398 pfd_confirm(c->u.pfd.s);
3401 if (c && c->closes) {
3403 * We have a pending close on this channel,
3404 * which we decided on before the server acked
3405 * the channel open. So now we know the
3406 * remoteid, we can close it again.
3408 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3409 PKT_INT, c->remoteid, PKT_END);
3412 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3413 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3414 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3415 struct ssh_channel *c;
3417 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3418 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3419 logevent("Forwarded connection refused by server");
3420 pfd_close(c->u.pfd.s);
3421 del234(ssh->channels, c);
3425 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3426 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3427 /* Remote side closes a channel. */
3428 unsigned i = GET_32BIT(ssh->pktin.body);
3429 struct ssh_channel *c;
3430 c = find234(ssh->channels, &i, ssh_channelfind);
3431 if (c && ((int)c->remoteid) != -1) {
3434 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3436 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3437 logevent("Forwarded X11 connection terminated");
3438 assert(c->u.x11.s != NULL);
3439 x11_close(c->u.x11.s);
3442 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3443 logevent("Forwarded port closed");
3444 assert(c->u.pfd.s != NULL);
3445 pfd_close(c->u.pfd.s);
3449 c->closes |= (closetype << 2); /* seen this message */
3450 if (!(c->closes & closetype)) {
3451 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3453 c->closes |= closetype; /* sent it too */
3456 if (c->closes == 15) {
3457 del234(ssh->channels, c);
3461 bombout((ssh,"Received CHANNEL_CLOSE%s for %s channel %d\n",
3462 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3463 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3466 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3467 /* Data sent down one of our channels. */
3468 int i = GET_32BIT(ssh->pktin.body);
3469 int len = GET_32BIT(ssh->pktin.body + 4);
3470 unsigned char *p = ssh->pktin.body + 8;
3471 struct ssh_channel *c;
3472 c = find234(ssh->channels, &i, ssh_channelfind);
3477 bufsize = x11_send(c->u.x11.s, p, len);
3480 bufsize = pfd_send(c->u.pfd.s, p, len);
3483 /* Data for an agent message. Buffer it. */
3485 if (c->u.a.lensofar < 4) {
3486 int l = min(4 - c->u.a.lensofar, len);
3487 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3491 c->u.a.lensofar += l;
3493 if (c->u.a.lensofar == 4) {
3495 4 + GET_32BIT(c->u.a.msglen);
3496 c->u.a.message = smalloc(c->u.a.totallen);
3497 memcpy(c->u.a.message, c->u.a.msglen, 4);
3499 if (c->u.a.lensofar >= 4 && len > 0) {
3501 min(c->u.a.totallen - c->u.a.lensofar,
3503 memcpy(c->u.a.message + c->u.a.lensofar, p,
3507 c->u.a.lensofar += l;
3509 if (c->u.a.lensofar == c->u.a.totallen) {
3510 void *reply, *sentreply;
3512 agent_query(c->u.a.message,
3513 c->u.a.totallen, &reply,
3518 /* Fake SSH_AGENT_FAILURE. */
3519 sentreply = "\0\0\0\1\5";
3522 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3523 PKT_INT, c->remoteid,
3525 PKT_DATA, sentreply, replylen,
3529 sfree(c->u.a.message);
3530 c->u.a.lensofar = 0;
3533 bufsize = 0; /* agent channels never back up */
3536 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3537 c->v.v1.throttling = 1;
3538 ssh1_throttle(ssh, +1);
3541 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3542 /* may be from EXEC_SHELL on some servers */
3543 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3544 /* may be from EXEC_SHELL on some servers
3545 * if no pty is available or in other odd cases. Ignore */
3546 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3548 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3549 sprintf(buf, "Server sent command exit status %d",
3552 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3554 * In case `helpful' firewalls or proxies tack
3555 * extra human-readable text on the end of the
3556 * session which we might mistake for another
3557 * encrypted packet, we close the session once
3558 * we've sent EXIT_CONFIRMATION.
3560 ssh->state = SSH_STATE_CLOSED;
3563 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
3568 int len = min(inlen, 512);
3569 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3570 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3581 * Utility routine for decoding comma-separated strings in KEXINIT.
3583 static int in_commasep_string(char *needle, char *haystack, int haylen)
3585 int needlen = strlen(needle);
3588 * Is it at the start of the string?
3590 if (haylen >= needlen && /* haystack is long enough */
3591 !memcmp(needle, haystack, needlen) && /* initial match */
3592 (haylen == needlen || haystack[needlen] == ',')
3593 /* either , or EOS follows */
3597 * If not, search for the next comma and resume after that.
3598 * If no comma found, terminate.
3600 while (haylen > 0 && *haystack != ',')
3601 haylen--, haystack++;
3604 haylen--, haystack++; /* skip over comma itself */
3609 * SSH2 key creation method.
3611 static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
3615 /* First 20 bytes. */
3617 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3619 SHA_Bytes(&s, H, 20);
3620 SHA_Bytes(&s, &chr, 1);
3621 SHA_Bytes(&s, sessid, 20);
3622 SHA_Final(&s, keyspace);
3623 /* Next 20 bytes. */
3625 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3627 SHA_Bytes(&s, H, 20);
3628 SHA_Bytes(&s, keyspace, 20);
3629 SHA_Final(&s, keyspace + 20);
3633 * Handle the SSH2 transport layer.
3635 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3637 struct do_ssh2_transport_state {
3638 int nbits, pbits, warn;
3639 Bignum p, g, e, f, K;
3640 int kex_init_value, kex_reply_value;
3641 const struct ssh_mac **maclist;
3643 const struct ssh2_cipher *cscipher_tobe;
3644 const struct ssh2_cipher *sccipher_tobe;
3645 const struct ssh_mac *csmac_tobe;
3646 const struct ssh_mac *scmac_tobe;
3647 const struct ssh_compress *cscomp_tobe;
3648 const struct ssh_compress *sccomp_tobe;
3649 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3650 int hostkeylen, siglen;
3651 void *hkey; /* actual host key */
3652 unsigned char exchange_hash[20];
3653 int n_preferred_ciphers;
3654 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3655 const struct ssh_compress *preferred_comp;
3658 crState(do_ssh2_transport_state);
3660 crBegin(ssh->do_ssh2_transport_crstate);
3662 s->cscipher_tobe = s->sccipher_tobe = NULL;
3663 s->csmac_tobe = s->scmac_tobe = NULL;
3664 s->cscomp_tobe = s->sccomp_tobe = NULL;
3672 * Set up the preferred ciphers. (NULL => warn below here)
3674 s->n_preferred_ciphers = 0;
3675 for (i = 0; i < CIPHER_MAX; i++) {
3676 switch (cfg.ssh_cipherlist[i]) {
3677 case CIPHER_BLOWFISH:
3678 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3681 if (cfg.ssh2_des_cbc) {
3682 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3686 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3689 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3692 /* Flag for later. Don't bother if it's the last in
3694 if (i < CIPHER_MAX - 1) {
3695 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3703 * Set up preferred compression.
3705 if (cfg.compression)
3706 s->preferred_comp = &ssh_zlib;
3708 s->preferred_comp = &ssh_comp_none;
3711 * Be prepared to work around the buggy MAC problem.
3713 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3714 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3716 s->maclist = macs, s->nmacs = lenof(macs);
3720 int i, j, cipherstr_started;
3723 * Construct and send our key exchange packet.
3725 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3726 for (i = 0; i < 16; i++)
3727 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3728 /* List key exchange algorithms. */
3729 ssh2_pkt_addstring_start(ssh);
3730 for (i = 0; i < lenof(kex_algs); i++) {
3731 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3732 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3734 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3735 if (i < lenof(kex_algs) - 1)
3736 ssh2_pkt_addstring_str(ssh, ",");
3738 /* List server host key algorithms. */
3739 ssh2_pkt_addstring_start(ssh);
3740 for (i = 0; i < lenof(hostkey_algs); i++) {
3741 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3742 if (i < lenof(hostkey_algs) - 1)
3743 ssh2_pkt_addstring_str(ssh, ",");
3745 /* List client->server encryption algorithms. */
3746 ssh2_pkt_addstring_start(ssh);
3747 cipherstr_started = 0;
3748 for (i = 0; i < s->n_preferred_ciphers; i++) {
3749 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3750 if (!c) continue; /* warning flag */
3751 for (j = 0; j < c->nciphers; j++) {
3752 if (cipherstr_started)
3753 ssh2_pkt_addstring_str(ssh, ",");
3754 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3755 cipherstr_started = 1;
3758 /* List server->client encryption algorithms. */
3759 ssh2_pkt_addstring_start(ssh);
3760 cipherstr_started = 0;
3761 for (i = 0; i < s->n_preferred_ciphers; i++) {
3762 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3763 if (!c) continue; /* warning flag */
3764 for (j = 0; j < c->nciphers; j++) {
3765 if (cipherstr_started)
3766 ssh2_pkt_addstring_str(ssh, ",");
3767 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3768 cipherstr_started = 1;
3771 /* List client->server MAC algorithms. */
3772 ssh2_pkt_addstring_start(ssh);
3773 for (i = 0; i < s->nmacs; i++) {
3774 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3775 if (i < s->nmacs - 1)
3776 ssh2_pkt_addstring_str(ssh, ",");
3778 /* List server->client 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 client->server compression algorithms. */
3786 ssh2_pkt_addstring_start(ssh);
3787 for (i = 0; i < lenof(compressions) + 1; i++) {
3788 const struct ssh_compress *c =
3789 i == 0 ? s->preferred_comp : compressions[i - 1];
3790 ssh2_pkt_addstring_str(ssh, c->name);
3791 if (i < lenof(compressions))
3792 ssh2_pkt_addstring_str(ssh, ",");
3794 /* List server->client compression algorithms. */
3795 ssh2_pkt_addstring_start(ssh);
3796 for (i = 0; i < lenof(compressions) + 1; i++) {
3797 const struct ssh_compress *c =
3798 i == 0 ? s->preferred_comp : compressions[i - 1];
3799 ssh2_pkt_addstring_str(ssh, c->name);
3800 if (i < lenof(compressions))
3801 ssh2_pkt_addstring_str(ssh, ",");
3803 /* List client->server languages. Empty list. */
3804 ssh2_pkt_addstring_start(ssh);
3805 /* List server->client languages. Empty list. */
3806 ssh2_pkt_addstring_start(ssh);
3807 /* First KEX packet does _not_ follow, because we're not that brave. */
3808 ssh2_pkt_addbool(ssh, FALSE);
3810 ssh2_pkt_adduint32(ssh, 0);
3813 ssh->exhash = ssh->exhashbase;
3814 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3820 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3823 * Now examine the other side's KEXINIT to see what we're up
3830 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3831 bombout((ssh,"expected key exchange packet from server"));
3835 ssh->hostkey = NULL;
3836 s->cscipher_tobe = NULL;
3837 s->sccipher_tobe = NULL;
3838 s->csmac_tobe = NULL;
3839 s->scmac_tobe = NULL;
3840 s->cscomp_tobe = NULL;
3841 s->sccomp_tobe = NULL;
3842 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3843 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3844 for (i = 0; i < lenof(kex_algs); i++) {
3845 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3846 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3848 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3849 ssh->kex = kex_algs[i];
3853 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3854 for (i = 0; i < lenof(hostkey_algs); i++) {
3855 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3856 ssh->hostkey = hostkey_algs[i];
3860 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3862 for (i = 0; i < s->n_preferred_ciphers; i++) {
3863 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3867 for (j = 0; j < c->nciphers; j++) {
3868 if (in_commasep_string(c->list[j]->name, str, len)) {
3869 s->cscipher_tobe = c->list[j];
3874 if (s->cscipher_tobe) {
3876 askcipher(ssh->frontend, s->cscipher_tobe->name, 1);
3880 if (!s->cscipher_tobe) {
3881 bombout((ssh,"Couldn't agree a client-to-server cipher (available: %s)", str));
3885 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3887 for (i = 0; i < s->n_preferred_ciphers; i++) {
3888 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3892 for (j = 0; j < c->nciphers; j++) {
3893 if (in_commasep_string(c->list[j]->name, str, len)) {
3894 s->sccipher_tobe = c->list[j];
3899 if (s->sccipher_tobe) {
3901 askcipher(ssh->frontend, s->sccipher_tobe->name, 2);
3905 if (!s->sccipher_tobe) {
3906 bombout((ssh,"Couldn't agree a server-to-client cipher (available: %s)", str));
3910 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3911 for (i = 0; i < s->nmacs; i++) {
3912 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3913 s->csmac_tobe = s->maclist[i];
3917 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3918 for (i = 0; i < s->nmacs; i++) {
3919 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3920 s->scmac_tobe = s->maclist[i];
3924 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3925 for (i = 0; i < lenof(compressions) + 1; i++) {
3926 const struct ssh_compress *c =
3927 i == 0 ? s->preferred_comp : compressions[i - 1];
3928 if (in_commasep_string(c->name, str, len)) {
3933 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3934 for (i = 0; i < lenof(compressions) + 1; i++) {
3935 const struct ssh_compress *c =
3936 i == 0 ? s->preferred_comp : compressions[i - 1];
3937 if (in_commasep_string(c->name, str, len)) {
3945 * Work out the number of bits of key we will need from the key
3946 * exchange. We start with the maximum key length of either
3952 csbits = s->cscipher_tobe->keylen;
3953 scbits = s->sccipher_tobe->keylen;
3954 s->nbits = (csbits > scbits ? csbits : scbits);
3956 /* The keys only have 160-bit entropy, since they're based on
3957 * a SHA-1 hash. So cap the key size at 160 bits. */
3962 * If we're doing Diffie-Hellman group exchange, start by
3963 * requesting a group.
3965 if (ssh->kex == &ssh_diffiehellman_gex) {
3966 logevent("Doing Diffie-Hellman group exchange");
3967 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3969 * Work out how big a DH group we will need to allow that
3972 s->pbits = 512 << ((s->nbits - 1) / 64);
3973 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3974 ssh2_pkt_adduint32(ssh, s->pbits);
3978 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3979 bombout((ssh,"expected key exchange group packet from server"));
3982 s->p = ssh2_pkt_getmp(ssh);
3983 s->g = ssh2_pkt_getmp(ssh);
3984 ssh->kex_ctx = dh_setup_group(s->p, s->g);
3985 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3986 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3988 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3989 ssh->kex_ctx = dh_setup_group1();
3990 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3991 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3994 logevent("Doing Diffie-Hellman key exchange");
3996 * Now generate and send e for Diffie-Hellman.
3998 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
3999 ssh2_pkt_init(ssh, s->kex_init_value);
4000 ssh2_pkt_addmp(ssh, s->e);
4004 if (ssh->pktin.type != s->kex_reply_value) {
4005 bombout((ssh,"expected key exchange reply packet from server"));
4008 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
4009 s->f = ssh2_pkt_getmp(ssh);
4010 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
4012 s->K = dh_find_K(ssh->kex_ctx, s->f);
4014 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
4015 if (ssh->kex == &ssh_diffiehellman_gex) {
4016 sha_uint32(&ssh->exhash, s->pbits);
4017 sha_mpint(&ssh->exhash, s->p);
4018 sha_mpint(&ssh->exhash, s->g);
4020 sha_mpint(&ssh->exhash, s->e);
4021 sha_mpint(&ssh->exhash, s->f);
4022 sha_mpint(&ssh->exhash, s->K);
4023 SHA_Final(&ssh->exhash, s->exchange_hash);
4025 dh_cleanup(ssh->kex_ctx);
4028 debug(("Exchange hash is:\n"));
4029 dmemdump(s->exchange_hash, 20);
4032 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
4034 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
4035 s->exchange_hash, 20)) {
4036 bombout((ssh,"Server's host key did not match the signature supplied"));
4041 * Authenticate remote host: verify host key. (We've already
4042 * checked the signature of the exchange hash.)
4044 s->keystr = ssh->hostkey->fmtkey(s->hkey);
4045 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
4046 verify_ssh_host_key(ssh->frontend,
4047 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
4048 s->keystr, s->fingerprint);
4049 if (s->first_kex) { /* don't bother logging this in rekeys */
4050 logevent("Host key fingerprint is:");
4051 logevent(s->fingerprint);
4053 sfree(s->fingerprint);
4055 ssh->hostkey->freekey(s->hkey);
4058 * Send SSH2_MSG_NEWKEYS.
4060 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4064 * Expect SSH2_MSG_NEWKEYS from server.
4067 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4068 bombout((ssh,"expected new-keys packet from server"));
4073 * Create and initialise session keys.
4075 if (ssh->cs_cipher_ctx)
4076 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
4077 ssh->cscipher = s->cscipher_tobe;
4078 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
4080 if (ssh->sc_cipher_ctx)
4081 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
4082 ssh->sccipher = s->sccipher_tobe;
4083 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
4085 if (ssh->cs_mac_ctx)
4086 ssh->csmac->free_context(ssh->cs_mac_ctx);
4087 ssh->csmac = s->csmac_tobe;
4088 ssh->cs_mac_ctx = ssh->csmac->make_context();
4090 if (ssh->sc_mac_ctx)
4091 ssh->scmac->free_context(ssh->sc_mac_ctx);
4092 ssh->scmac = s->scmac_tobe;
4093 ssh->sc_mac_ctx = ssh->scmac->make_context();
4095 if (ssh->cs_comp_ctx)
4096 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
4097 ssh->cscomp = s->cscomp_tobe;
4098 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
4100 if (ssh->sc_comp_ctx)
4101 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
4102 ssh->sccomp = s->sccomp_tobe;
4103 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
4106 * Set IVs after keys. Here we use the exchange hash from the
4107 * _first_ key exchange.
4110 unsigned char keyspace[40];
4112 memcpy(ssh->v2_session_id, s->exchange_hash,
4113 sizeof(s->exchange_hash));
4114 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4115 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
4116 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4117 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
4118 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4119 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
4120 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4121 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
4122 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4123 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
4124 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4125 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
4129 sprintf(buf, "Initialised %.200s client->server encryption",
4130 ssh->cscipher->text_name);
4132 sprintf(buf, "Initialised %.200s server->client encryption",
4133 ssh->sccipher->text_name);
4135 if (ssh->cscomp->text_name) {
4136 sprintf(buf, "Initialised %.200s compression",
4137 ssh->cscomp->text_name);
4140 if (ssh->sccomp->text_name) {
4141 sprintf(buf, "Initialised %.200s decompression",
4142 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);
4357 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 sprintf(stuff, "Using username \"%s\".\r\n", s->username);
4365 c_write_str(ssh, stuff);
4368 s->got_username = TRUE;
4371 * Send an authentication request using method "none": (a)
4372 * just in case it succeeds, and (b) so that we know what
4373 * authentication methods we can usefully try next.
4375 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4377 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4378 ssh2_pkt_addstring(ssh, s->username);
4379 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4380 ssh2_pkt_addstring(ssh, "none"); /* method */
4382 s->type = AUTH_TYPE_NONE;
4384 s->we_are_in = FALSE;
4386 s->tried_pubkey_config = FALSE;
4387 s->tried_agent = FALSE;
4388 s->tried_keyb_inter = FALSE;
4389 s->kbd_inter_running = FALSE;
4390 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4393 logeventf(ssh->frontend,
4394 "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->frontend,
4403 "Unable to use this key file (%s)",
4404 key_type_to_str(keytype));
4405 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4406 cfg.keyfile, key_type_to_str(keytype));
4407 c_write_str(ssh, msgbuf);
4408 s->publickey_blob = NULL;
4411 s->publickey_blob = NULL;
4415 * Wait for the result of the last authentication request.
4418 crWaitUntilV(ispkt);
4419 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4423 * Don't show the banner if we're operating in
4424 * non-verbose non-interactive mode. (It's probably
4425 * a script, which means nobody will read the
4426 * banner _anyway_, and moreover the printing of
4427 * the banner will screw up processing on the
4428 * output of (say) plink.)
4430 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4431 ssh2_pkt_getstring(ssh, &banner, &size);
4433 c_write_untrusted(ssh, banner, size);
4435 crWaitUntilV(ispkt);
4437 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4438 logevent("Access granted");
4439 s->we_are_in = TRUE;
4443 if (s->kbd_inter_running &&
4444 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4446 * This is either a further set-of-prompts packet
4447 * in keyboard-interactive authentication, or it's
4448 * the same one and we came back here with `gotit'
4449 * set. In the former case, we must reset the
4450 * curr_prompt variable.
4454 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4455 bombout((ssh,"Strange packet received during authentication: type %d",
4463 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4464 * we can look at the string in it and know what we can
4465 * helpfully try next.
4467 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4470 ssh2_pkt_getstring(ssh, &methods, &methlen);
4471 s->kbd_inter_running = FALSE;
4472 if (!ssh2_pkt_getbool(ssh)) {
4474 * We have received an unequivocal Access
4475 * Denied. This can translate to a variety of
4478 * - if we'd just tried "none" authentication,
4479 * it's not worth printing anything at all
4481 * - if we'd just tried a public key _offer_,
4482 * the message should be "Server refused our
4483 * key" (or no message at all if the key
4484 * came from Pageant)
4486 * - if we'd just tried anything else, the
4487 * message really should be "Access denied".
4489 * Additionally, if we'd just tried password
4490 * authentication, we should break out of this
4491 * whole loop so as to go back to the username
4494 if (s->type == AUTH_TYPE_NONE) {
4496 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4497 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4498 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4499 c_write_str(ssh, "Server refused our key\r\n");
4500 logevent("Server refused public key");
4501 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4502 /* server declined keyboard-interactive; ignore */
4504 c_write_str(ssh, "Access denied\r\n");
4505 logevent("Access denied");
4506 if (s->type == AUTH_TYPE_PASSWORD) {
4507 s->we_are_in = FALSE;
4512 c_write_str(ssh, "Further authentication required\r\n");
4513 logevent("Further authentication required");
4517 in_commasep_string("publickey", methods, methlen);
4519 in_commasep_string("password", methods, methlen);
4520 s->can_keyb_inter = cfg.try_ki_auth &&
4521 in_commasep_string("keyboard-interactive", methods, methlen);
4525 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4528 * Most password/passphrase prompts will be
4529 * non-echoing, so we set this to 0 by default.
4530 * Exception is that some keyboard-interactive prompts
4531 * can be echoing, in which case we'll set this to 1.
4535 if (!s->method && s->can_pubkey &&
4536 agent_exists() && !s->tried_agent) {
4538 * Attempt public-key authentication using Pageant.
4543 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4544 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4546 s->tried_agent = TRUE;
4548 logevent("Pageant is running. Requesting keys.");
4550 /* Request the keys held by the agent. */
4551 PUT_32BIT(s->request, 1);
4552 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4553 agent_query(s->request, 5, &r, &s->responselen);
4554 s->response = (unsigned char *) r;
4555 if (s->response && s->responselen >= 5 &&
4556 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4557 s->p = s->response + 5;
4558 s->nkeys = GET_32BIT(s->p);
4562 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4565 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4570 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4573 s->pklen = GET_32BIT(s->p);
4575 if (s->publickey_blob &&
4576 s->pklen == s->publickey_bloblen &&
4577 !memcmp(s->p, s->publickey_blob,
4578 s->publickey_bloblen)) {
4579 logevent("This key matches configured key file");
4580 s->tried_pubkey_config = 1;
4584 s->alglen = GET_32BIT(s->pkblob);
4585 s->alg = s->pkblob + 4;
4586 s->commentlen = GET_32BIT(s->p);
4589 s->p += s->commentlen;
4590 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4591 ssh2_pkt_addstring(ssh, s->username);
4592 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4593 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4594 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4595 ssh2_pkt_addstring_start(ssh);
4596 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4597 ssh2_pkt_addstring_start(ssh);
4598 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4601 crWaitUntilV(ispkt);
4602 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4603 logevent("Key refused");
4607 if (flags & FLAG_VERBOSE) {
4608 c_write_str(ssh, "Authenticating with "
4610 c_write(ssh, s->commentp, s->commentlen);
4611 c_write_str(ssh, "\" from agent\r\n");
4615 * Server is willing to accept the key.
4616 * Construct a SIGN_REQUEST.
4618 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4619 ssh2_pkt_addstring(ssh, s->username);
4620 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4621 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4622 ssh2_pkt_addbool(ssh, TRUE);
4623 ssh2_pkt_addstring_start(ssh);
4624 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4625 ssh2_pkt_addstring_start(ssh);
4626 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4628 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4629 s->len = 1; /* message type */
4630 s->len += 4 + s->pklen; /* key blob */
4631 s->len += 4 + s->siglen; /* data to sign */
4632 s->len += 4; /* flags */
4633 s->agentreq = smalloc(4 + s->len);
4634 PUT_32BIT(s->agentreq, s->len);
4635 s->q = s->agentreq + 4;
4636 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4637 PUT_32BIT(s->q, s->pklen);
4639 memcpy(s->q, s->pkblob, s->pklen);
4641 PUT_32BIT(s->q, s->siglen);
4643 /* Now the data to be signed... */
4644 PUT_32BIT(s->q, 20);
4646 memcpy(s->q, ssh->v2_session_id, 20);
4648 memcpy(s->q, ssh->pktout.data + 5,
4649 ssh->pktout.length - 5);
4650 s->q += ssh->pktout.length - 5;
4651 /* And finally the (zero) flags word. */
4653 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4657 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4658 logevent("Sending Pageant's response");
4659 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4661 GET_32BIT(s->ret + 5));
4667 ("Pageant failed to answer challenge");
4677 if (!s->method && s->can_pubkey && s->publickey_blob
4678 && !s->tried_pubkey_config) {
4679 unsigned char *pub_blob;
4680 char *algorithm, *comment;
4683 s->tried_pubkey_config = TRUE;
4685 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4686 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4689 * Try the public key supplied in the configuration.
4691 * First, offer the public blob to see if the server is
4692 * willing to accept it.
4694 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4697 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4698 ssh2_pkt_addstring(ssh, s->username);
4699 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4700 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4701 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4702 ssh2_pkt_addstring(ssh, algorithm);
4703 ssh2_pkt_addstring_start(ssh);
4704 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4706 logevent("Offered public key"); /* FIXME */
4708 crWaitUntilV(ispkt);
4709 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4711 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4712 continue; /* key refused; give up on it */
4715 logevent("Offer of public key accepted");
4717 * Actually attempt a serious authentication using
4720 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4721 sprintf(s->pwprompt,
4722 "Passphrase for key \"%.100s\": ",
4728 c_write_str(ssh, "Authenticating with public key \"");
4729 c_write_str(ssh, comment);
4730 c_write_str(ssh, "\"\r\n");
4731 s->method = AUTH_PUBLICKEY_FILE;
4735 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4736 s->method = AUTH_KEYBOARD_INTERACTIVE;
4737 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4738 s->tried_keyb_inter = TRUE;
4740 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4741 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4743 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4744 ssh2_pkt_addstring(ssh, s->username);
4745 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4746 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4747 ssh2_pkt_addstring(ssh, ""); /* lang */
4748 ssh2_pkt_addstring(ssh, "");
4751 crWaitUntilV(ispkt);
4752 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4753 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4755 logevent("Keyboard-interactive authentication refused");
4756 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4760 s->kbd_inter_running = TRUE;
4764 if (s->kbd_inter_running) {
4765 s->method = AUTH_KEYBOARD_INTERACTIVE;
4766 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4767 s->tried_keyb_inter = TRUE;
4769 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4770 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4772 if (s->curr_prompt == 0) {
4774 * We've got a fresh USERAUTH_INFO_REQUEST.
4775 * Display header data, and start going through
4778 char *name, *inst, *lang;
4779 int name_len, inst_len, lang_len;
4781 ssh2_pkt_getstring(ssh, &name, &name_len);
4782 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4783 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4785 c_write_untrusted(ssh, name, name_len);
4786 c_write_str(ssh, "\r\n");
4789 c_write_untrusted(ssh, inst, inst_len);
4790 c_write_str(ssh, "\r\n");
4792 s->num_prompts = ssh2_pkt_getuint32(ssh);
4796 * If there are prompts remaining in the packet,
4797 * display one and get a response.
4799 if (s->curr_prompt < s->num_prompts) {
4803 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4804 if (prompt_len > 0) {
4805 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4806 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4807 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4810 "<server failed to send prompt>: ");
4812 s->echo = ssh2_pkt_getbool(ssh);
4818 if (!s->method && s->can_passwd) {
4819 s->method = AUTH_PASSWORD;
4820 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4821 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4822 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4829 if (!ssh_get_line(s->pwprompt, s->password,
4830 sizeof(s->password), TRUE)) {
4832 * get_line failed to get a password (for
4833 * example because one was supplied on the
4834 * command line which has already failed to
4837 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4838 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4839 ssh2_pkt_addstring(ssh, "No more passwords available"
4841 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4843 logevent("Unable to authenticate");
4844 connection_fatal(ssh->frontend,
4845 "Unable to authenticate");
4846 ssh->state = SSH_STATE_CLOSED;
4850 int ret; /* need not be saved across crReturn */
4851 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4854 setup_userpass_input(ssh, s->password,
4855 sizeof(s->password), s->echo);
4857 crWaitUntilV(!ispkt);
4858 ret = process_userpass_input(ssh, in, inlen);
4862 c_write_str(ssh, "\r\n");
4866 if (s->method == AUTH_PUBLICKEY_FILE) {
4868 * We have our passphrase. Now try the actual authentication.
4870 struct ssh2_userkey *key;
4872 key = ssh2_load_userkey(cfg.keyfile, s->password);
4873 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4874 if (key == SSH2_WRONG_PASSPHRASE) {
4875 c_write_str(ssh, "Wrong passphrase\r\n");
4876 s->tried_pubkey_config = FALSE;
4878 c_write_str(ssh, "Unable to load private key\r\n");
4879 s->tried_pubkey_config = TRUE;
4881 /* Send a spurious AUTH_NONE to return to the top. */
4882 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4883 ssh2_pkt_addstring(ssh, s->username);
4884 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4885 ssh2_pkt_addstring(ssh, "none"); /* method */
4887 s->type = AUTH_TYPE_NONE;
4889 unsigned char *pkblob, *sigblob, *sigdata;
4890 int pkblob_len, sigblob_len, sigdata_len;
4893 * We have loaded the private key and the server
4894 * has announced that it's willing to accept it.
4895 * Hallelujah. Generate a signature and send it.
4897 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4898 ssh2_pkt_addstring(ssh, s->username);
4899 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4900 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4901 ssh2_pkt_addbool(ssh, TRUE);
4902 ssh2_pkt_addstring(ssh, key->alg->name);
4903 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4904 ssh2_pkt_addstring_start(ssh);
4905 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
4908 * The data to be signed is:
4912 * followed by everything so far placed in the
4915 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4916 sigdata = smalloc(sigdata_len);
4917 PUT_32BIT(sigdata, 20);
4918 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4919 memcpy(sigdata + 24, ssh->pktout.data + 5,
4920 ssh->pktout.length - 5);
4921 sigblob = key->alg->sign(key->data, sigdata,
4922 sigdata_len, &sigblob_len);
4923 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4924 sigblob, sigblob_len);
4930 s->type = AUTH_TYPE_PUBLICKEY;
4932 } else if (s->method == AUTH_PASSWORD) {
4934 * We send the password packet lumped tightly together with
4935 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4936 * string long enough to make the total length of the two
4937 * packets constant. This should ensure that a passive
4938 * listener doing traffic analyis can't work out the length
4941 * For this to work, we need an assumption about the
4942 * maximum length of the password packet. I think 256 is
4943 * pretty conservative. Anyone using a password longer than
4944 * that probably doesn't have much to worry about from
4945 * people who find out how long their password is!
4947 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4948 ssh2_pkt_addstring(ssh, s->username);
4949 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4950 ssh2_pkt_addstring(ssh, "password");
4951 ssh2_pkt_addbool(ssh, FALSE);
4952 ssh2_pkt_addstring(ssh, s->password);
4953 ssh2_pkt_defer(ssh);
4955 * We'll include a string that's an exact multiple of the
4956 * cipher block size. If the cipher is NULL for some
4957 * reason, we don't do this trick at all because we gain
4960 if (ssh->cscipher) {
4963 stringlen = (256 - ssh->deferred_len);
4964 stringlen += ssh->cscipher->blksize - 1;
4965 stringlen -= (stringlen % ssh->cscipher->blksize);
4968 * Temporarily disable actual compression,
4969 * so we can guarantee to get this string
4970 * exactly the length we want it. The
4971 * compression-disabling routine should
4972 * return an integer indicating how many
4973 * bytes we should adjust our string length
4977 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
4979 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4980 ssh2_pkt_addstring_start(ssh);
4981 for (i = 0; i < stringlen; i++) {
4982 char c = (char) random_byte();
4983 ssh2_pkt_addstring_data(ssh, &c, 1);
4985 ssh2_pkt_defer(ssh);
4987 ssh_pkt_defersend(ssh);
4988 logevent("Sent password");
4989 s->type = AUTH_TYPE_PASSWORD;
4990 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4991 if (s->curr_prompt == 0) {
4992 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4993 ssh2_pkt_adduint32(ssh, s->num_prompts);
4995 if (s->need_pw) { /* only add pw if we just got one! */
4996 ssh2_pkt_addstring(ssh, s->password);
4997 memset(s->password, 0, sizeof(s->password));
5000 if (s->curr_prompt >= s->num_prompts) {
5004 * If there are prompts remaining, we set
5005 * `gotit' so that we won't attempt to get
5006 * another packet. Then we go back round the
5007 * loop and will end up retrieving another
5008 * prompt out of the existing packet. Funky or
5013 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
5015 c_write_str(ssh, "No supported authentication methods"
5016 " left to try!\r\n");
5017 logevent("No supported authentications offered."
5019 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5020 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5021 ssh2_pkt_addstring(ssh, "No supported authentication"
5022 " methods available");
5023 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5025 ssh->state = SSH_STATE_CLOSED;
5029 } while (!s->we_are_in);
5032 * Now we're authenticated for the connection protocol. The
5033 * connection protocol will automatically have started at this
5034 * point; there's no need to send SERVICE_REQUEST.
5038 * So now create a channel with a session in it.
5040 ssh->channels = newtree234(ssh_channelcmp);
5041 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
5042 ssh->mainchan->ssh = ssh;
5043 ssh->mainchan->localid = alloc_channel_id(ssh);
5044 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
5045 ssh2_pkt_addstring(ssh, "session");
5046 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
5047 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
5048 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
5049 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5051 crWaitUntilV(ispkt);
5052 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5053 bombout((ssh,"Server refused to open a session"));
5055 /* FIXME: error data comes back in FAILURE packet */
5057 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
5058 bombout((ssh,"Server's channel confirmation cited wrong channel"));
5061 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
5062 ssh->mainchan->type = CHAN_MAINSESSION;
5063 ssh->mainchan->closes = 0;
5064 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5065 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5066 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
5067 add234(ssh->channels, ssh->mainchan);
5068 logevent("Opened channel for session");
5071 * Potentially enable X11 forwarding.
5073 if (cfg.x11_forward) {
5074 char proto[20], data[64];
5075 logevent("Requesting X11 forwarding");
5076 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
5077 data, sizeof(data));
5078 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5079 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5080 ssh2_pkt_addstring(ssh, "x11-req");
5081 ssh2_pkt_addbool(ssh, 1); /* want reply */
5082 ssh2_pkt_addbool(ssh, 0); /* many connections */
5083 ssh2_pkt_addstring(ssh, proto);
5084 ssh2_pkt_addstring(ssh, data);
5085 ssh2_pkt_adduint32(ssh, 0); /* screen number */
5089 crWaitUntilV(ispkt);
5090 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5091 unsigned i = ssh2_pkt_getuint32(ssh);
5092 struct ssh_channel *c;
5093 c = find234(ssh->channels, &i, ssh_channelfind);
5095 continue; /* nonexistent channel */
5096 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5098 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5100 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5101 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5102 bombout((ssh,"Unexpected response to X11 forwarding request:"
5103 " packet type %d", ssh->pktin.type));
5106 logevent("X11 forwarding refused");
5108 logevent("X11 forwarding enabled");
5109 ssh->X11_fwd_enabled = TRUE;
5114 * Enable port forwardings.
5119 int sport,dport,sserv,dserv;
5120 char sports[256], dports[256], host[256];
5124 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5125 /* Add port forwardings. */
5126 ssh->portfwd_strptr = cfg.portfwd;
5127 while (*ssh->portfwd_strptr) {
5128 type = *ssh->portfwd_strptr++;
5130 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5131 sports[n++] = *ssh->portfwd_strptr++;
5133 if (*ssh->portfwd_strptr == '\t')
5134 ssh->portfwd_strptr++;
5136 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5137 host[n++] = *ssh->portfwd_strptr++;
5139 if (*ssh->portfwd_strptr == ':')
5140 ssh->portfwd_strptr++;
5142 while (*ssh->portfwd_strptr)
5143 dports[n++] = *ssh->portfwd_strptr++;
5145 ssh->portfwd_strptr++;
5146 dport = atoi(dports);
5150 se = getservbyname(dports, NULL);
5152 dport = ntohs(se->s_port);
5155 "Service lookup failed for destination port \"%s\"",
5160 sport = atoi(sports);
5164 se = getservbyname(sports, NULL);
5166 sport = ntohs(se->s_port);
5169 "Service lookup failed for source port \"%s\"",
5174 if (sport && dport) {
5176 pfd_addforward(host, dport, sport, ssh);
5177 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5178 " %s:%.*s%.*s%d%.*s",
5179 sserv ? strlen(sports) : 0, sports,
5180 sserv, "(", sport, sserv, ")",
5182 dserv ? strlen(dports) : 0, dports,
5183 dserv, "(", dport, dserv, ")");
5186 struct ssh_rportfwd *pf;
5187 pf = smalloc(sizeof(*pf));
5188 strcpy(pf->dhost, host);
5191 if (add234(ssh->rportfwds, pf) != pf) {
5193 "Duplicate remote port forwarding to %s:%d",
5198 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5199 " forward to %s:%.*s%.*s%d%.*s",
5200 sserv ? strlen(sports) : 0, sports,
5201 sserv, "(", sport, sserv, ")",
5203 dserv ? strlen(dports) : 0, dports,
5204 dserv, "(", dport, dserv, ")");
5206 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5207 ssh2_pkt_addstring(ssh, "tcpip-forward");
5208 ssh2_pkt_addbool(ssh, 1);/* want reply */
5209 if (cfg.rport_acceptall)
5210 ssh2_pkt_addstring(ssh, "0.0.0.0");
5212 ssh2_pkt_addstring(ssh, "127.0.0.1");
5213 ssh2_pkt_adduint32(ssh, sport);
5217 crWaitUntilV(ispkt);
5218 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5219 unsigned i = ssh2_pkt_getuint32(ssh);
5220 struct ssh_channel *c;
5221 c = find234(ssh->channels, &i, ssh_channelfind);
5223 continue;/* nonexistent channel */
5224 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5226 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5228 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5229 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5230 bombout((ssh,"Unexpected response to port "
5231 "forwarding request: packet type %d",
5235 logevent("Server refused this port forwarding");
5237 logevent("Remote port forwarding enabled");
5246 * Potentially enable agent forwarding.
5248 if (cfg.agentfwd && agent_exists()) {
5249 logevent("Requesting OpenSSH-style agent forwarding");
5250 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5251 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5252 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5253 ssh2_pkt_addbool(ssh, 1); /* want reply */
5257 crWaitUntilV(ispkt);
5258 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5259 unsigned i = ssh2_pkt_getuint32(ssh);
5260 struct ssh_channel *c;
5261 c = find234(ssh->channels, &i, ssh_channelfind);
5263 continue; /* nonexistent channel */
5264 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5266 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5268 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5269 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5270 bombout((ssh,"Unexpected response to agent forwarding request:"
5271 " packet type %d", ssh->pktin.type));
5274 logevent("Agent forwarding refused");
5276 logevent("Agent forwarding enabled");
5277 ssh->agentfwd_enabled = TRUE;
5282 * Now allocate a pty for the session.
5285 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5286 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5287 ssh2_pkt_addstring(ssh, "pty-req");
5288 ssh2_pkt_addbool(ssh, 1); /* want reply */
5289 ssh2_pkt_addstring(ssh, cfg.termtype);
5290 ssh2_pkt_adduint32(ssh, ssh->term_width);
5291 ssh2_pkt_adduint32(ssh, ssh->term_height);
5292 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5293 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5294 ssh2_pkt_addstring_start(ssh);
5295 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5297 ssh->state = SSH_STATE_INTERMED;
5300 crWaitUntilV(ispkt);
5301 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5302 unsigned i = ssh2_pkt_getuint32(ssh);
5303 struct ssh_channel *c;
5304 c = find234(ssh->channels, &i, ssh_channelfind);
5306 continue; /* nonexistent channel */
5307 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5309 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5311 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5312 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5313 bombout((ssh,"Unexpected response to pty request:"
5314 " packet type %d", ssh->pktin.type));
5317 c_write_str(ssh, "Server refused to allocate pty\r\n");
5318 ssh->editing = ssh->echoing = 1;
5320 logevent("Allocated pty");
5323 ssh->editing = ssh->echoing = 1;
5327 * Start a shell or a remote command. We may have to attempt
5328 * this twice if the config data has provided a second choice
5335 if (ssh->fallback_cmd) {
5336 subsys = cfg.ssh_subsys2;
5337 cmd = cfg.remote_cmd_ptr2;
5339 subsys = cfg.ssh_subsys;
5340 cmd = cfg.remote_cmd_ptr;
5343 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5344 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5346 ssh2_pkt_addstring(ssh, "subsystem");
5347 ssh2_pkt_addbool(ssh, 1); /* want reply */
5348 ssh2_pkt_addstring(ssh, cmd);
5350 ssh2_pkt_addstring(ssh, "exec");
5351 ssh2_pkt_addbool(ssh, 1); /* want reply */
5352 ssh2_pkt_addstring(ssh, cmd);
5354 ssh2_pkt_addstring(ssh, "shell");
5355 ssh2_pkt_addbool(ssh, 1); /* want reply */
5359 crWaitUntilV(ispkt);
5360 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5361 unsigned i = ssh2_pkt_getuint32(ssh);
5362 struct ssh_channel *c;
5363 c = find234(ssh->channels, &i, ssh_channelfind);
5365 continue; /* nonexistent channel */
5366 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5368 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5369 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5370 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5371 bombout((ssh,"Unexpected response to shell/command request:"
5372 " packet type %d", ssh->pktin.type));
5376 * We failed to start the command. If this is the
5377 * fallback command, we really are finished; if it's
5378 * not, and if the fallback command exists, try falling
5379 * back to it before complaining.
5381 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5382 logevent("Primary command failed; attempting fallback");
5383 ssh->fallback_cmd = TRUE;
5386 bombout((ssh,"Server refused to start a shell/command"));
5389 logevent("Started a shell/command");
5394 ssh->state = SSH_STATE_SESSION;
5395 if (ssh->size_needed)
5396 ssh_size(ssh, ssh->term_width, ssh->term_height);
5397 if (ssh->eof_needed)
5398 ssh_special(ssh, TS_EOF);
5404 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
5408 s->try_send = FALSE;
5410 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5411 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5414 unsigned i = ssh2_pkt_getuint32(ssh);
5415 struct ssh_channel *c;
5416 c = find234(ssh->channels, &i, ssh_channelfind);
5418 continue; /* nonexistent channel */
5419 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5420 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5421 continue; /* extended but not stderr */
5422 ssh2_pkt_getstring(ssh, &data, &length);
5425 c->v.v2.locwindow -= length;
5427 case CHAN_MAINSESSION:
5429 from_backend(ssh->frontend, ssh->pktin.type ==
5430 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5434 bufsize = x11_send(c->u.x11.s, data, length);
5437 bufsize = pfd_send(c->u.pfd.s, data, length);
5440 while (length > 0) {
5441 if (c->u.a.lensofar < 4) {
5442 int l = min(4 - c->u.a.lensofar, length);
5443 memcpy(c->u.a.msglen + c->u.a.lensofar,
5447 c->u.a.lensofar += l;
5449 if (c->u.a.lensofar == 4) {
5451 4 + GET_32BIT(c->u.a.msglen);
5452 c->u.a.message = smalloc(c->u.a.totallen);
5453 memcpy(c->u.a.message, c->u.a.msglen, 4);
5455 if (c->u.a.lensofar >= 4 && length > 0) {
5457 min(c->u.a.totallen - c->u.a.lensofar,
5459 memcpy(c->u.a.message + c->u.a.lensofar,
5463 c->u.a.lensofar += l;
5465 if (c->u.a.lensofar == c->u.a.totallen) {
5466 void *reply, *sentreply;
5468 agent_query(c->u.a.message,
5469 c->u.a.totallen, &reply,
5474 /* Fake SSH_AGENT_FAILURE. */
5475 sentreply = "\0\0\0\1\5";
5478 ssh2_add_channel_data(c, sentreply, replylen);
5482 sfree(c->u.a.message);
5483 c->u.a.lensofar = 0;
5490 * If we are not buffering too much data,
5491 * enlarge the window again at the remote side.
5493 if (bufsize < OUR_V2_WINSIZE)
5494 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5496 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5497 unsigned i = ssh2_pkt_getuint32(ssh);
5498 struct ssh_channel *c;
5500 c = find234(ssh->channels, &i, ssh_channelfind);
5502 continue; /* nonexistent channel */
5504 if (c->type == CHAN_X11) {
5506 * Remote EOF on an X11 channel means we should
5507 * wrap up and close the channel ourselves.
5509 x11_close(c->u.x11.s);
5511 } else if (c->type == CHAN_AGENT) {
5513 } else if (c->type == CHAN_SOCKDATA) {
5514 pfd_close(c->u.pfd.s);
5517 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5518 unsigned i = ssh2_pkt_getuint32(ssh);
5519 struct ssh_channel *c;
5521 c = find234(ssh->channels, &i, ssh_channelfind);
5522 if (!c || ((int)c->remoteid) == -1) {
5523 bombout((ssh,"Received CHANNEL_CLOSE for %s channel %d\n",
5524 c ? "half-open" : "nonexistent", i));
5526 /* Do pre-close processing on the channel. */
5528 case CHAN_MAINSESSION:
5529 break; /* nothing to see here, move along */
5531 if (c->u.x11.s != NULL)
5532 x11_close(c->u.x11.s);
5539 if (c->u.pfd.s != NULL)
5540 pfd_close(c->u.pfd.s);
5544 if (c->closes == 0) {
5545 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5546 ssh2_pkt_adduint32(ssh, c->remoteid);
5549 del234(ssh->channels, c);
5550 bufchain_clear(&c->v.v2.outbuffer);
5554 * See if that was the last channel left open.
5556 if (count234(ssh->channels) == 0) {
5559 * We used to send SSH_MSG_DISCONNECT here,
5560 * because I'd believed that _every_ conforming
5561 * SSH2 connection had to end with a disconnect
5562 * being sent by at least one side; apparently
5563 * I was wrong and it's perfectly OK to
5564 * unceremoniously slam the connection shut
5565 * when you're done, and indeed OpenSSH feels
5566 * this is more polite than sending a
5567 * DISCONNECT. So now we don't.
5569 logevent("All channels closed. Disconnecting");
5570 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5571 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5572 ssh2_pkt_addstring(ssh, "All open channels closed");
5573 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5576 ssh->state = SSH_STATE_CLOSED;
5579 continue; /* remote sends close; ignore (FIXME) */
5580 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5581 unsigned i = ssh2_pkt_getuint32(ssh);
5582 struct ssh_channel *c;
5583 c = find234(ssh->channels, &i, ssh_channelfind);
5585 continue; /* nonexistent channel */
5586 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5588 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5589 unsigned i = ssh2_pkt_getuint32(ssh);
5590 struct ssh_channel *c;
5591 c = find234(ssh->channels, &i, ssh_channelfind);
5593 continue; /* nonexistent channel */
5594 if (c->type != CHAN_SOCKDATA_DORMANT)
5595 continue; /* dunno why they're confirming this */
5596 c->remoteid = ssh2_pkt_getuint32(ssh);
5597 c->type = CHAN_SOCKDATA;
5598 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5599 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5601 pfd_confirm(c->u.pfd.s);
5604 * We have a pending close on this channel,
5605 * which we decided on before the server acked
5606 * the channel open. So now we know the
5607 * remoteid, we can close it again.
5609 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5610 ssh2_pkt_adduint32(ssh, c->remoteid);
5613 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5614 unsigned i = ssh2_pkt_getuint32(ssh);
5615 struct ssh_channel *c;
5616 c = find234(ssh->channels, &i, ssh_channelfind);
5618 continue; /* nonexistent channel */
5619 if (c->type != CHAN_SOCKDATA_DORMANT)
5620 continue; /* dunno why they're failing this */
5622 logevent("Forwarded connection refused by server");
5624 pfd_close(c->u.pfd.s);
5626 del234(ssh->channels, c);
5628 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5631 int typelen, want_reply;
5632 struct ssh_channel *c;
5634 localid = ssh2_pkt_getuint32(ssh);
5635 ssh2_pkt_getstring(ssh, &type, &typelen);
5636 want_reply = ssh2_pkt_getbool(ssh);
5639 * First, check that the channel exists. Otherwise,
5640 * we can instantly disconnect with a rude message.
5642 c = find234(ssh->channels, &localid, ssh_channelfind);
5645 sprintf(buf, "Received channel request for nonexistent"
5646 " channel %d", localid);
5648 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5649 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5650 ssh2_pkt_addstring(ssh, buf);
5651 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5653 connection_fatal("%s", buf);
5654 ssh->state = SSH_STATE_CLOSED;
5659 * Having got the channel number, we now look at
5660 * the request type string to see if it's something
5663 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5664 c == ssh->mainchan) {
5665 /* We recognise "exit-status" on the primary channel. */
5667 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5668 sprintf(buf, "Server sent command exit status %d",
5672 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5673 ssh2_pkt_adduint32(ssh, c->remoteid);
5678 * This is a channel request we don't know
5679 * about, so we now either ignore the request
5680 * or respond with CHANNEL_FAILURE, depending
5684 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5685 ssh2_pkt_adduint32(ssh, c->remoteid);
5689 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5691 int typelen, want_reply;
5693 ssh2_pkt_getstring(ssh, &type, &typelen);
5694 want_reply = ssh2_pkt_getbool(ssh);
5697 * We currently don't support any global requests
5698 * at all, so we either ignore the request or
5699 * respond with REQUEST_FAILURE, depending on
5703 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5706 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5710 struct ssh_channel *c;
5711 unsigned remid, winsize, pktsize;
5712 ssh2_pkt_getstring(ssh, &type, &typelen);
5713 c = smalloc(sizeof(struct ssh_channel));
5716 remid = ssh2_pkt_getuint32(ssh);
5717 winsize = ssh2_pkt_getuint32(ssh);
5718 pktsize = ssh2_pkt_getuint32(ssh);
5720 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5721 if (!ssh->X11_fwd_enabled)
5722 error = "X11 forwarding is not enabled";
5723 else if (x11_init(&c->u.x11.s, cfg.x11_display, c,
5724 ssh->x11auth) != NULL) {
5725 error = "Unable to open an X11 connection";
5729 } else if (typelen == 15 &&
5730 !memcmp(type, "forwarded-tcpip", 15)) {
5731 struct ssh_rportfwd pf, *realpf;
5734 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5735 pf.sport = ssh2_pkt_getuint32(ssh);
5736 realpf = find234(ssh->rportfwds, &pf, NULL);
5737 if (realpf == NULL) {
5738 error = "Remote port is not recognised";
5740 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5743 sprintf(buf, "Received remote port open request for %s:%d",
5744 realpf->dhost, realpf->dport);
5747 sprintf(buf, "Port open failed: %s", e);
5749 error = "Port open failed";
5751 logevent("Forwarded port opened successfully");
5752 c->type = CHAN_SOCKDATA;
5755 } else if (typelen == 22 &&
5756 !memcmp(type, "auth-agent@openssh.com", 3)) {
5757 if (!ssh->agentfwd_enabled)
5758 error = "Agent forwarding is not enabled";
5760 c->type = CHAN_AGENT; /* identify channel type */
5761 c->u.a.lensofar = 0;
5764 error = "Unsupported channel type requested";
5767 c->remoteid = remid;
5769 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5770 ssh2_pkt_adduint32(ssh, c->remoteid);
5771 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5772 ssh2_pkt_addstring(ssh, error);
5773 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5777 c->localid = alloc_channel_id(ssh);
5779 c->v.v2.locwindow = OUR_V2_WINSIZE;
5780 c->v.v2.remwindow = winsize;
5781 c->v.v2.remmaxpkt = pktsize;
5782 bufchain_init(&c->v.v2.outbuffer);
5783 add234(ssh->channels, c);
5784 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5785 ssh2_pkt_adduint32(ssh, c->remoteid);
5786 ssh2_pkt_adduint32(ssh, c->localid);
5787 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5788 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5792 bombout((ssh,"Strange packet received: type %d", ssh->pktin.type));
5797 * We have spare data. Add it to the channel buffer.
5799 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5804 struct ssh_channel *c;
5806 * Try to send data on all channels if we can.
5808 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5809 int bufsize = ssh2_try_send(c);
5812 case CHAN_MAINSESSION:
5813 /* stdin need not receive an unthrottle
5814 * notification since it will be polled */
5817 x11_unthrottle(c->u.x11.s);
5820 /* agent sockets are request/response and need no
5821 * buffer management */
5824 pfd_unthrottle(c->u.pfd.s);
5836 * Handle the top-level SSH2 protocol.
5838 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5840 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5842 do_ssh2_authconn(ssh, in, inlen, ispkt);
5846 * Called to set up the connection.
5848 * Returns an error message, or NULL on success.
5850 static char *ssh_init(void *frontend_handle, void **backend_handle,
5851 char *host, int port, char **realhost, int nodelay)
5856 ssh = smalloc(sizeof(*ssh));
5859 ssh->v1_cipher_ctx = NULL;
5860 ssh->crcda_ctx = NULL;
5861 ssh->cscipher = NULL;
5862 ssh->cs_cipher_ctx = NULL;
5863 ssh->sccipher = NULL;
5864 ssh->sc_cipher_ctx = NULL;
5866 ssh->cs_mac_ctx = NULL;
5868 ssh->sc_mac_ctx = NULL;
5870 ssh->cs_comp_ctx = NULL;
5872 ssh->sc_comp_ctx = NULL;
5874 ssh->hostkey = NULL;
5876 ssh->state = SSH_STATE_PREPACKET;
5877 ssh->size_needed = FALSE;
5878 ssh->eof_needed = FALSE;
5882 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5883 ssh->pktin = ssh->pktout = empty;
5885 ssh->deferred_send_data = NULL;
5886 ssh->deferred_len = 0;
5887 ssh->deferred_size = 0;
5888 ssh->fallback_cmd = 0;
5890 ssh->x11auth = NULL;
5891 ssh->v1_compressing = FALSE;
5892 ssh->v2_outgoing_sequence = 0;
5893 ssh->ssh1_rdpkt_crstate = 0;
5894 ssh->ssh2_rdpkt_crstate = 0;
5895 ssh->do_ssh_init_crstate = 0;
5896 ssh->ssh_gotdata_crstate = 0;
5897 ssh->ssh1_protocol_crstate = 0;
5898 ssh->do_ssh1_login_crstate = 0;
5899 ssh->do_ssh2_transport_crstate = 0;
5900 ssh->do_ssh2_authconn_crstate = 0;
5901 ssh->do_ssh_init_state = NULL;
5902 ssh->do_ssh1_login_state = NULL;
5903 ssh->do_ssh2_transport_state = NULL;
5904 ssh->do_ssh2_authconn_state = NULL;
5905 ssh->mainchan = NULL;
5907 *backend_handle = ssh;
5910 if (crypto_startup() == 0)
5911 return "Microsoft high encryption pack not installed!";
5914 ssh->frontend = frontend_handle;
5915 ssh->term_width = cfg.width;
5916 ssh->term_height = cfg.height;
5921 ssh->v1_throttle_count = 0;
5922 ssh->overall_bufsize = 0;
5923 ssh->fallback_cmd = 0;
5925 p = connect_to_host(ssh, host, port, realhost, nodelay);
5933 * Called to send data down the Telnet connection.
5935 static int ssh_send(void *handle, char *buf, int len)
5937 Ssh ssh = (Ssh) handle;
5939 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5942 ssh->protocol(ssh, buf, len, 0);
5944 return ssh_sendbuffer(ssh);
5948 * Called to query the current amount of buffered stdin data.
5950 static int ssh_sendbuffer(void *handle)
5952 Ssh ssh = (Ssh) handle;
5955 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5959 * If the SSH socket itself has backed up, add the total backup
5960 * size on that to any individual buffer on the stdin channel.
5963 if (ssh->throttled_all)
5964 override_value = ssh->overall_bufsize;
5966 if (ssh->version == 1) {
5967 return override_value;
5968 } else if (ssh->version == 2) {
5969 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5970 return override_value;
5972 return (override_value +
5973 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5980 * Called to set the size of the window from SSH's POV.
5982 static void ssh_size(void *handle, int width, int height)
5984 Ssh ssh = (Ssh) handle;
5986 ssh->term_width = width;
5987 ssh->term_height = height;
5989 switch (ssh->state) {
5990 case SSH_STATE_BEFORE_SIZE:
5991 case SSH_STATE_PREPACKET:
5992 case SSH_STATE_CLOSED:
5993 break; /* do nothing */
5994 case SSH_STATE_INTERMED:
5995 ssh->size_needed = TRUE; /* buffer for later */
5997 case SSH_STATE_SESSION:
5999 if (ssh->version == 1) {
6000 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
6001 PKT_INT, ssh->term_height,
6002 PKT_INT, ssh->term_width,
6003 PKT_INT, 0, PKT_INT, 0, PKT_END);
6005 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
6006 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6007 ssh2_pkt_addstring(ssh, "window-change");
6008 ssh2_pkt_addbool(ssh, 0);
6009 ssh2_pkt_adduint32(ssh, ssh->term_width);
6010 ssh2_pkt_adduint32(ssh, ssh->term_height);
6011 ssh2_pkt_adduint32(ssh, 0);
6012 ssh2_pkt_adduint32(ssh, 0);
6021 * Send Telnet special codes. TS_EOF is useful for `plink', so you
6022 * can send an EOF and collect resulting output (e.g. `plink
6025 static void ssh_special(void *handle, Telnet_Special code)
6027 Ssh ssh = (Ssh) handle;
6029 if (code == TS_EOF) {
6030 if (ssh->state != SSH_STATE_SESSION) {
6032 * Buffer the EOF in case we are pre-SESSION, so we can
6033 * send it as soon as we reach SESSION.
6036 ssh->eof_needed = TRUE;
6039 if (ssh->version == 1) {
6040 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
6042 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
6043 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
6046 logevent("Sent EOF message");
6047 } else if (code == TS_PING) {
6048 if (ssh->state == SSH_STATE_CLOSED
6049 || ssh->state == SSH_STATE_PREPACKET) return;
6050 if (ssh->version == 1) {
6051 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
6052 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
6054 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
6055 ssh2_pkt_addstring_start(ssh);
6063 void *new_sock_channel(void *handle, Socket s)
6065 Ssh ssh = (Ssh) handle;
6066 struct ssh_channel *c;
6067 c = smalloc(sizeof(struct ssh_channel));
6071 c->remoteid = -1; /* to be set when open confirmed */
6072 c->localid = alloc_channel_id(ssh);
6074 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
6076 bufchain_init(&c->v.v2.outbuffer);
6077 add234(ssh->channels, c);
6083 * This is called when stdout/stderr (the entity to which
6084 * from_backend sends data) manages to clear some backlog.
6086 void ssh_unthrottle(void *handle, int bufsize)
6088 Ssh ssh = (Ssh) handle;
6089 if (ssh->version == 1) {
6090 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
6091 ssh->v1_stdout_throttling = 0;
6092 ssh1_throttle(ssh, -1);
6095 if (ssh->mainchan && ssh->mainchan->closes == 0)
6096 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
6100 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
6102 struct ssh_channel *c = (struct ssh_channel *)channel;
6106 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
6109 if (ssh->version == 1) {
6110 send_packet(ssh, SSH1_MSG_PORT_OPEN,
6111 PKT_INT, c->localid,
6114 //PKT_STR, <org:orgport>,
6117 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6118 ssh2_pkt_addstring(ssh, "direct-tcpip");
6119 ssh2_pkt_adduint32(ssh, c->localid);
6120 c->v.v2.locwindow = OUR_V2_WINSIZE;
6121 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6122 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6123 ssh2_pkt_addstring(ssh, hostname);
6124 ssh2_pkt_adduint32(ssh, port);
6126 * We make up values for the originator data; partly it's
6127 * too much hassle to keep track, and partly I'm not
6128 * convinced the server should be told details like that
6129 * about my local network configuration.
6131 ssh2_pkt_addstring(ssh, "client-side-connection");
6132 ssh2_pkt_adduint32(ssh, 0);
6138 static Socket ssh_socket(void *handle)
6140 Ssh ssh = (Ssh) handle;
6144 static int ssh_sendok(void *handle)
6146 Ssh ssh = (Ssh) handle;
6147 return ssh->send_ok;
6150 static int ssh_ldisc(void *handle, int option)
6152 Ssh ssh = (Ssh) handle;
6153 if (option == LD_ECHO)
6154 return ssh->echoing;
6155 if (option == LD_EDIT)
6156 return ssh->editing;
6160 static void ssh_provide_ldisc(void *handle, void *ldisc)
6162 Ssh ssh = (Ssh) handle;
6166 static void ssh_provide_logctx(void *handle, void *logctx)
6168 Ssh ssh = (Ssh) handle;
6169 ssh->logctx = logctx;
6172 static int ssh_return_exitcode(void *handle)
6174 Ssh ssh = (Ssh) handle;
6175 return ssh->exitcode;
6179 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6180 * that fails. This variable is the means by which scp.c can reach
6181 * into the SSH code and find out which one it got.
6183 extern int ssh_fallback_cmd(void *handle)
6185 Ssh ssh = (Ssh) handle;
6186 return ssh->fallback_cmd;
6189 Backend ssh_backend = {
6196 ssh_return_exitcode,