18 #define logevent(s) { logevent(s); \
19 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
20 { fprintf(stderr, "%s\n", s); fflush(stderr); } }
22 /* logevent, only printf-formatted. */
23 void logeventf(char *fmt, ...)
29 vsprintf(stuff, fmt, ap);
34 #define bombout(msg) ( ssh->state = SSH_STATE_CLOSED, \
35 (ssh->s ? sk_close(ssh->s), ssh->s = NULL : 0), \
36 logeventf msg, connection_fatal msg )
38 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
39 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
40 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
41 #define SSH1_CMSG_USER 4 /* 0x4 */
42 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
43 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
44 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
45 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
46 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
47 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
48 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
49 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
50 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
51 #define SSH1_SMSG_FAILURE 15 /* 0xf */
52 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
53 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
54 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
55 #define SSH1_CMSG_EOF 19 /* 0x13 */
56 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
57 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
58 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
59 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
60 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
61 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
62 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
63 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
64 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
65 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
66 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
67 #define SSH1_MSG_IGNORE 32 /* 0x20 */
68 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
69 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
70 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
71 #define SSH1_MSG_DEBUG 36 /* 0x24 */
72 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
73 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
74 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
75 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
76 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
77 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
78 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
80 #define SSH1_AUTH_TIS 5 /* 0x5 */
81 #define SSH1_AUTH_CCARD 16 /* 0x10 */
83 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
84 /* Mask for protoflags we will echo back to server if seen */
85 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
87 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
88 #define SSH2_MSG_IGNORE 2 /* 0x2 */
89 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
90 #define SSH2_MSG_DEBUG 4 /* 0x4 */
91 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
92 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
93 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
94 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
95 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
96 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
97 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
98 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
99 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
100 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
101 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
102 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
103 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
104 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
105 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
106 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
107 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
108 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
109 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
110 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
111 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
112 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
113 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
114 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
115 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
116 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
117 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
118 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
119 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
120 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
121 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
122 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
125 * Packet type contexts, so that ssh2_pkt_type can correctly decode
126 * the ambiguous type numbers back into the correct type strings.
128 #define SSH2_PKTCTX_DHGROUP1 0x0001
129 #define SSH2_PKTCTX_DHGEX 0x0002
130 #define SSH2_PKTCTX_PUBLICKEY 0x0010
131 #define SSH2_PKTCTX_PASSWORD 0x0020
132 #define SSH2_PKTCTX_KBDINTER 0x0040
133 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
135 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
136 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
137 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
138 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
139 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
140 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
141 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
142 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
143 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
144 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
145 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
146 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
147 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
148 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
149 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
151 static const char *const ssh2_disconnect_reasons[] = {
153 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
154 "SSH_DISCONNECT_PROTOCOL_ERROR",
155 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
156 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
157 "SSH_DISCONNECT_MAC_ERROR",
158 "SSH_DISCONNECT_COMPRESSION_ERROR",
159 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
160 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
161 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
162 "SSH_DISCONNECT_CONNECTION_LOST",
163 "SSH_DISCONNECT_BY_APPLICATION",
164 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
165 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
166 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
167 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
170 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
171 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
172 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
173 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
175 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
178 * Various remote-bug flags.
180 #define BUG_CHOKES_ON_SSH1_IGNORE 1
181 #define BUG_SSH2_HMAC 2
182 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
183 #define BUG_CHOKES_ON_RSA 8
184 #define BUG_SSH2_RSA_PADDING 16
185 #define BUG_SSH2_DERIVEKEY 32
186 #define BUG_SSH2_DH_GEX 64
188 #define translate(x) if (type == x) return #x
189 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
190 char *ssh1_pkt_type(int type)
192 translate(SSH1_MSG_DISCONNECT);
193 translate(SSH1_SMSG_PUBLIC_KEY);
194 translate(SSH1_CMSG_SESSION_KEY);
195 translate(SSH1_CMSG_USER);
196 translate(SSH1_CMSG_AUTH_RSA);
197 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
198 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
199 translate(SSH1_CMSG_AUTH_PASSWORD);
200 translate(SSH1_CMSG_REQUEST_PTY);
201 translate(SSH1_CMSG_WINDOW_SIZE);
202 translate(SSH1_CMSG_EXEC_SHELL);
203 translate(SSH1_CMSG_EXEC_CMD);
204 translate(SSH1_SMSG_SUCCESS);
205 translate(SSH1_SMSG_FAILURE);
206 translate(SSH1_CMSG_STDIN_DATA);
207 translate(SSH1_SMSG_STDOUT_DATA);
208 translate(SSH1_SMSG_STDERR_DATA);
209 translate(SSH1_CMSG_EOF);
210 translate(SSH1_SMSG_EXIT_STATUS);
211 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
212 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
213 translate(SSH1_MSG_CHANNEL_DATA);
214 translate(SSH1_MSG_CHANNEL_CLOSE);
215 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
216 translate(SSH1_SMSG_X11_OPEN);
217 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
218 translate(SSH1_MSG_PORT_OPEN);
219 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
220 translate(SSH1_SMSG_AGENT_OPEN);
221 translate(SSH1_MSG_IGNORE);
222 translate(SSH1_CMSG_EXIT_CONFIRMATION);
223 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
224 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
225 translate(SSH1_MSG_DEBUG);
226 translate(SSH1_CMSG_REQUEST_COMPRESSION);
227 translate(SSH1_CMSG_AUTH_TIS);
228 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
229 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
230 translate(SSH1_CMSG_AUTH_CCARD);
231 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
232 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
235 char *ssh2_pkt_type(int pkt_ctx, int type)
237 translate(SSH2_MSG_DISCONNECT);
238 translate(SSH2_MSG_IGNORE);
239 translate(SSH2_MSG_UNIMPLEMENTED);
240 translate(SSH2_MSG_DEBUG);
241 translate(SSH2_MSG_SERVICE_REQUEST);
242 translate(SSH2_MSG_SERVICE_ACCEPT);
243 translate(SSH2_MSG_KEXINIT);
244 translate(SSH2_MSG_NEWKEYS);
245 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP1);
246 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP1);
247 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
248 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
249 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
250 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
251 translate(SSH2_MSG_USERAUTH_REQUEST);
252 translate(SSH2_MSG_USERAUTH_FAILURE);
253 translate(SSH2_MSG_USERAUTH_SUCCESS);
254 translate(SSH2_MSG_USERAUTH_BANNER);
255 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
256 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
257 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
258 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
259 translate(SSH2_MSG_GLOBAL_REQUEST);
260 translate(SSH2_MSG_REQUEST_SUCCESS);
261 translate(SSH2_MSG_REQUEST_FAILURE);
262 translate(SSH2_MSG_CHANNEL_OPEN);
263 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
264 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
265 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
266 translate(SSH2_MSG_CHANNEL_DATA);
267 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
268 translate(SSH2_MSG_CHANNEL_EOF);
269 translate(SSH2_MSG_CHANNEL_CLOSE);
270 translate(SSH2_MSG_CHANNEL_REQUEST);
271 translate(SSH2_MSG_CHANNEL_SUCCESS);
272 translate(SSH2_MSG_CHANNEL_FAILURE);
278 #define GET_32BIT(cp) \
279 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
280 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
281 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
282 ((unsigned long)(unsigned char)(cp)[3]))
284 #define PUT_32BIT(cp, value) { \
285 (cp)[0] = (unsigned char)((value) >> 24); \
286 (cp)[1] = (unsigned char)((value) >> 16); \
287 (cp)[2] = (unsigned char)((value) >> 8); \
288 (cp)[3] = (unsigned char)(value); }
290 enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
292 /* Coroutine mechanics for the sillier bits of the code */
293 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
296 if (!ssh->t) ssh->t = smalloc(sizeof(struct t)); \
298 #define crFinish(z) } *crLine = 0; return (z); }
299 #define crFinishV } *crLine = 0; return; }
300 #define crReturn(z) \
302 *crLine =__LINE__; return (z); case __LINE__:;\
306 *crLine=__LINE__; return; case __LINE__:;\
308 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
309 #define crStopV do{ *crLine = 0; return; }while(0)
310 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
311 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
313 typedef struct ssh_tag *Ssh;
315 extern char *x11_init(Socket *, char *, void *);
316 extern void x11_close(Socket);
317 extern int x11_send(Socket, char *, int);
318 extern void x11_invent_auth(char *, int, char *, int);
319 extern void x11_unthrottle(Socket s);
320 extern void x11_override_throttle(Socket s, int enable);
322 extern char *pfd_newconnect(Socket * s, char *hostname, int port, void *c);
323 extern char *pfd_addforward(char *desthost, int destport, int port);
324 extern void pfd_close(Socket s);
325 extern int pfd_send(Socket s, char *data, int len);
326 extern void pfd_confirm(Socket s);
327 extern void pfd_unthrottle(Socket s);
328 extern void pfd_override_throttle(Socket s, int enable);
330 static void ssh2_pkt_init(Ssh, int pkt_type);
331 static void ssh2_pkt_addbool(Ssh, unsigned char value);
332 static void ssh2_pkt_adduint32(Ssh, unsigned long value);
333 static void ssh2_pkt_addstring_start(Ssh);
334 static void ssh2_pkt_addstring_str(Ssh, char *data);
335 static void ssh2_pkt_addstring_data(Ssh, char *data, int len);
336 static void ssh2_pkt_addstring(Ssh, char *data);
337 static char *ssh2_mpint_fmt(Bignum b, int *len);
338 static void ssh2_pkt_addmp(Ssh, Bignum b);
339 static int ssh2_pkt_construct(Ssh);
340 static void ssh2_pkt_send(Ssh);
343 * Buffer management constants. There are several of these for
344 * various different purposes:
346 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
347 * on a local data stream before we throttle the whole SSH
348 * connection (in SSH1 only). Throttling the whole connection is
349 * pretty drastic so we set this high in the hope it won't
352 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
353 * on the SSH connection itself before we defensively throttle
354 * _all_ local data streams. This is pretty drastic too (though
355 * thankfully unlikely in SSH2 since the window mechanism should
356 * ensure that the server never has any need to throttle its end
357 * of the connection), so we set this high as well.
359 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
363 #define SSH1_BUFFER_LIMIT 32768
364 #define SSH_MAX_BACKLOG 32768
365 #define OUR_V2_WINSIZE 16384
367 const static struct ssh_kex *kex_algs[] = {
368 &ssh_diffiehellman_gex,
372 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
374 static void nullmac_key(unsigned char *key)
377 static void nullmac_generate(unsigned char *blk, int len,
381 static int nullmac_verify(unsigned char *blk, int len, unsigned long seq)
385 const static struct ssh_mac ssh_mac_none = {
386 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
388 const static struct ssh_mac *macs[] = {
389 &ssh_sha1, &ssh_md5, &ssh_mac_none
391 const static struct ssh_mac *buggymacs[] = {
392 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
395 static void ssh_comp_none_init(void)
398 static int ssh_comp_none_block(unsigned char *block, int len,
399 unsigned char **outblock, int *outlen)
403 static int ssh_comp_none_disable(void)
407 const static struct ssh_compress ssh_comp_none = {
409 ssh_comp_none_init, ssh_comp_none_block,
410 ssh_comp_none_init, ssh_comp_none_block,
411 ssh_comp_none_disable
413 extern const struct ssh_compress ssh_zlib;
414 const static struct ssh_compress *compressions[] = {
415 &ssh_zlib, &ssh_comp_none
418 enum { /* channel types */
423 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
427 * 2-3-4 tree storing channels.
430 Ssh ssh; /* pointer back to main context */
431 unsigned remoteid, localid;
434 * In SSH1, this value contains four bits:
436 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
437 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
438 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
439 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
441 * A channel is completely finished with when all four bits are set.
445 struct ssh1_data_channel {
448 struct ssh2_data_channel {
450 unsigned remwindow, remmaxpkt;
455 struct ssh_agent_channel {
456 unsigned char *message;
457 unsigned char msglen[4];
458 int lensofar, totallen;
460 struct ssh_x11_channel {
463 struct ssh_pfd_channel {
470 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
471 * 2 use this structure in different ways, reflecting SSH 2's
472 * altogether saner approach to port forwarding.
474 * In SSH 1, you arrange a remote forwarding by sending the server
475 * the remote port number, and the local destination host:port.
476 * When a connection comes in, the server sends you back that
477 * host:port pair, and you connect to it. This is a ready-made
478 * security hole if you're not on the ball: a malicious server
479 * could send you back _any_ host:port pair, so if you trustingly
480 * connect to the address it gives you then you've just opened the
481 * entire inside of your corporate network just by connecting
482 * through it to a dodgy SSH server. Hence, we must store a list of
483 * host:port pairs we _are_ trying to forward to, and reject a
484 * connection request from the server if it's not in the list.
486 * In SSH 2, each side of the connection minds its own business and
487 * doesn't send unnecessary information to the other. You arrange a
488 * remote forwarding by sending the server just the remote port
489 * number. When a connection comes in, the server tells you which
490 * of its ports was connected to; and _you_ have to remember what
491 * local host:port pair went with that port number.
493 * Hence: in SSH 1 this structure stores host:port pairs we intend
494 * to allow connections to, and is indexed by those host:port
495 * pairs. In SSH 2 it stores a mapping from source port to
496 * destination host:port pair, and is indexed by source port.
498 struct ssh_rportfwd {
499 unsigned sport, dport;
512 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
513 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt);
514 static void ssh_size(void *handle, int width, int height);
515 static void ssh_special(void *handle, Telnet_Special);
516 static int ssh2_try_send(struct ssh_channel *c);
517 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
518 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
519 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
520 static int ssh_sendbuffer(void *handle);
522 struct rdpkt1_state_tag {
523 long len, pad, biglen, to_read;
524 unsigned long realcrc, gotcrc;
530 struct rdpkt2_state_tag {
531 long len, pad, payload, packetlen, maclen;
534 unsigned long incoming_sequence;
538 const struct plug_function_table *fn;
539 /* the above field _must_ be first in the structure */
541 SHA_State exhash, exhashbase;
545 unsigned char session_key[32];
547 int v1_remote_protoflags;
548 int v1_local_protoflags;
549 int agentfwd_enabled;
552 const struct ssh_cipher *cipher;
553 const struct ssh2_cipher *cscipher, *sccipher;
554 const struct ssh_mac *csmac, *scmac;
555 const struct ssh_compress *cscomp, *sccomp;
556 const struct ssh_kex *kex;
557 const struct ssh_signkey *hostkey;
558 unsigned char v2_session_id[20];
563 int echoing, editing;
567 int term_width, term_height;
569 tree234 *channels; /* indexed by local id */
570 struct ssh_channel *mainchan; /* primary session channel */
577 SSH_STATE_BEFORE_SIZE,
583 int size_needed, eof_needed;
586 struct Packet pktout;
587 unsigned char *deferred_send_data;
588 int deferred_len, deferred_size;
591 * Gross hack: pscp will try to start SFTP but fall back to
592 * scp1 if that fails. This variable is the means by which
593 * scp.c can reach into the SSH code and find out which one it
599 * Used for username and password input.
601 char *userpass_input_buffer;
602 int userpass_input_buflen;
603 int userpass_input_bufpos;
604 int userpass_input_echo;
606 char *portfwd_strptr;
610 int v1_throttle_count;
613 int v1_stdout_throttling;
614 int v2_outgoing_sequence;
616 int ssh1_rdpkt_crstate;
617 int ssh2_rdpkt_crstate;
618 int do_ssh_init_crstate;
619 int ssh_gotdata_crstate;
620 int ssh1_protocol_crstate;
621 int do_ssh1_login_crstate;
622 int do_ssh2_transport_crstate;
623 int do_ssh2_authconn_crstate;
625 void *do_ssh_init_state;
626 void *do_ssh1_login_state;
627 void *do_ssh2_transport_state;
628 void *do_ssh2_authconn_state;
630 struct rdpkt1_state_tag rdpkt1_state;
631 struct rdpkt2_state_tag rdpkt2_state;
633 void (*protocol) (Ssh ssh, unsigned char *in, int inlen, int ispkt);
634 int (*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
637 static int ssh_channelcmp(void *av, void *bv)
639 struct ssh_channel *a = (struct ssh_channel *) av;
640 struct ssh_channel *b = (struct ssh_channel *) bv;
641 if (a->localid < b->localid)
643 if (a->localid > b->localid)
647 static int ssh_channelfind(void *av, void *bv)
649 unsigned *a = (unsigned *) av;
650 struct ssh_channel *b = (struct ssh_channel *) bv;
658 static int ssh_rportcmp_ssh1(void *av, void *bv)
660 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
661 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
663 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
664 return i < 0 ? -1 : +1;
665 if (a->dport > b->dport)
667 if (a->dport < b->dport)
672 static int ssh_rportcmp_ssh2(void *av, void *bv)
674 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
675 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
677 if (a->sport > b->sport)
679 if (a->sport < b->sport)
684 static int alloc_channel_id(Ssh ssh)
686 const unsigned CHANNEL_NUMBER_OFFSET = 256;
687 unsigned low, high, mid;
689 struct ssh_channel *c;
692 * First-fit allocation of channel numbers: always pick the
693 * lowest unused one. To do this, binary-search using the
694 * counted B-tree to find the largest channel ID which is in a
695 * contiguous sequence from the beginning. (Precisely
696 * everything in that sequence must have ID equal to its tree
697 * index plus CHANNEL_NUMBER_OFFSET.)
699 tsize = count234(ssh->channels);
703 while (high - low > 1) {
704 mid = (high + low) / 2;
705 c = index234(ssh->channels, mid);
706 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
707 low = mid; /* this one is fine */
709 high = mid; /* this one is past it */
712 * Now low points to either -1, or the tree index of the
713 * largest ID in the initial sequence.
716 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
717 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
719 return low + 1 + CHANNEL_NUMBER_OFFSET;
722 static void c_write(Ssh ssh, char *buf, int len)
724 if ((flags & FLAG_STDERR)) {
726 for (i = 0; i < len; i++)
728 fputc(buf[i], stderr);
731 from_backend(ssh->frontend, 1, buf, len);
734 static void c_write_untrusted(Ssh ssh, char *buf, int len)
737 for (i = 0; i < len; i++) {
739 c_write(ssh, "\r\n", 2);
740 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
741 c_write(ssh, buf + i, 1);
745 static void c_write_str(Ssh ssh, char *buf)
747 c_write(ssh, buf, strlen(buf));
751 * Collect incoming data in the incoming packet buffer.
752 * Decipher and verify the packet when it is completely read.
753 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
754 * Update the *data and *datalen variables.
755 * Return the additional nr of bytes needed, or 0 when
756 * a complete packet is available.
758 static int ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
760 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
762 crBegin(ssh->ssh1_rdpkt_crstate);
767 ssh->pktin.length = 0;
769 for (st->i = st->len = 0; st->i < 4; st->i++) {
770 while ((*datalen) == 0)
772 st->len = (st->len << 8) + **data;
773 (*data)++, (*datalen)--;
776 st->pad = 8 - (st->len % 8);
777 st->biglen = st->len + st->pad;
778 ssh->pktin.length = st->len - 5;
780 if (ssh->pktin.maxlen < st->biglen) {
781 ssh->pktin.maxlen = st->biglen;
782 ssh->pktin.data = srealloc(ssh->pktin.data, st->biglen + APIEXTRA);
785 st->to_read = st->biglen;
786 st->p = ssh->pktin.data;
787 while (st->to_read > 0) {
788 st->chunk = st->to_read;
789 while ((*datalen) == 0)
790 crReturn(st->to_read);
791 if (st->chunk > (*datalen))
792 st->chunk = (*datalen);
793 memcpy(st->p, *data, st->chunk);
795 *datalen -= st->chunk;
797 st->to_read -= st->chunk;
800 if (ssh->cipher && detect_attack(ssh->pktin.data, st->biglen, NULL)) {
801 bombout(("Network attack (CRC compensation) detected!"));
806 ssh->cipher->decrypt(ssh->pktin.data, st->biglen);
808 st->realcrc = crc32(ssh->pktin.data, st->biglen - 4);
809 st->gotcrc = GET_32BIT(ssh->pktin.data + st->biglen - 4);
810 if (st->gotcrc != st->realcrc) {
811 bombout(("Incorrect CRC received on packet"));
815 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
817 if (ssh->v1_compressing) {
818 unsigned char *decompblk;
820 zlib_decompress_block(ssh->pktin.body - 1, ssh->pktin.length + 1,
821 &decompblk, &decomplen);
823 if (ssh->pktin.maxlen < st->pad + decomplen) {
824 ssh->pktin.maxlen = st->pad + decomplen;
825 ssh->pktin.data = srealloc(ssh->pktin.data,
826 ssh->pktin.maxlen + APIEXTRA);
827 ssh->pktin.body = ssh->pktin.data + st->pad + 1;
830 memcpy(ssh->pktin.body - 1, decompblk, decomplen);
832 ssh->pktin.length = decomplen - 1;
835 ssh->pktin.type = ssh->pktin.body[-1];
837 log_packet(PKT_INCOMING, ssh->pktin.type, ssh1_pkt_type(ssh->pktin.type),
838 ssh->pktin.body, ssh->pktin.length);
840 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
841 ssh->pktin.type == SSH1_SMSG_STDERR_DATA ||
842 ssh->pktin.type == SSH1_MSG_DEBUG ||
843 ssh->pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
844 ssh->pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
845 long stringlen = GET_32BIT(ssh->pktin.body);
846 if (stringlen + 4 != ssh->pktin.length) {
847 bombout(("Received data packet with bogus string length"));
852 if (ssh->pktin.type == SSH1_MSG_DEBUG) {
853 /* log debug message */
855 int stringlen = GET_32BIT(ssh->pktin.body);
856 strcpy(buf, "Remote debug message: ");
859 memcpy(buf + 8, ssh->pktin.body + 4, stringlen);
860 buf[8 + stringlen] = '\0';
863 } else if (ssh->pktin.type == SSH1_MSG_IGNORE) {
868 if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
869 /* log reason code in disconnect message */
871 unsigned msglen = GET_32BIT(ssh->pktin.body);
873 strcpy(buf, "Remote sent disconnect: ");
874 nowlen = strlen(buf);
875 if (msglen > sizeof(buf) - nowlen - 1)
876 msglen = sizeof(buf) - nowlen - 1;
877 memcpy(buf + nowlen, ssh->pktin.body + 4, msglen);
878 buf[nowlen + msglen] = '\0';
879 /* logevent(buf); (this is now done within the bombout macro) */
880 bombout(("Server sent disconnect message:\n\"%s\"", buf+nowlen));
887 static int ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
889 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
891 crBegin(ssh->ssh2_rdpkt_crstate);
895 ssh->pktin.length = 0;
897 st->cipherblk = ssh->sccipher->blksize;
900 if (st->cipherblk < 8)
903 if (ssh->pktin.maxlen < st->cipherblk) {
904 ssh->pktin.maxlen = st->cipherblk;
905 ssh->pktin.data = srealloc(ssh->pktin.data, st->cipherblk + APIEXTRA);
909 * Acquire and decrypt the first block of the packet. This will
910 * contain the length and padding details.
912 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
913 while ((*datalen) == 0)
914 crReturn(st->cipherblk - st->i);
915 ssh->pktin.data[st->i] = *(*data)++;
920 ssh->sccipher->decrypt(ssh->pktin.data, st->cipherblk);
923 * Now get the length and padding figures.
925 st->len = GET_32BIT(ssh->pktin.data);
926 st->pad = ssh->pktin.data[4];
929 * _Completely_ silly lengths should be stomped on before they
930 * do us any more damage.
932 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
933 bombout(("Incoming packet was garbled on decryption"));
938 * This enables us to deduce the payload length.
940 st->payload = st->len - st->pad - 1;
942 ssh->pktin.length = st->payload + 5;
945 * So now we can work out the total packet length.
947 st->packetlen = st->len + 4;
948 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
951 * Adjust memory allocation if packet is too big.
953 if (ssh->pktin.maxlen < st->packetlen + st->maclen) {
954 ssh->pktin.maxlen = st->packetlen + st->maclen;
955 ssh->pktin.data = srealloc(ssh->pktin.data,
956 ssh->pktin.maxlen + APIEXTRA);
960 * Read and decrypt the remainder of the packet.
962 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
964 while ((*datalen) == 0)
965 crReturn(st->packetlen + st->maclen - st->i);
966 ssh->pktin.data[st->i] = *(*data)++;
969 /* Decrypt everything _except_ the MAC. */
971 ssh->sccipher->decrypt(ssh->pktin.data + st->cipherblk,
972 st->packetlen - st->cipherblk);
978 && !ssh->scmac->verify(ssh->pktin.data, st->len + 4,
979 st->incoming_sequence)) {
980 bombout(("Incorrect MAC received on packet"));
983 st->incoming_sequence++; /* whether or not we MACed */
986 * Decompress packet payload.
989 unsigned char *newpayload;
992 ssh->sccomp->decompress(ssh->pktin.data + 5, ssh->pktin.length - 5,
993 &newpayload, &newlen)) {
994 if (ssh->pktin.maxlen < newlen + 5) {
995 ssh->pktin.maxlen = newlen + 5;
996 ssh->pktin.data = srealloc(ssh->pktin.data,
997 ssh->pktin.maxlen + APIEXTRA);
999 ssh->pktin.length = 5 + newlen;
1000 memcpy(ssh->pktin.data + 5, newpayload, newlen);
1005 ssh->pktin.savedpos = 6;
1006 ssh->pktin.type = ssh->pktin.data[5];
1008 log_packet(PKT_INCOMING, ssh->pktin.type,
1009 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktin.type),
1010 ssh->pktin.data+6, ssh->pktin.length-6);
1012 switch (ssh->pktin.type) {
1014 * These packets we must handle instantly.
1016 case SSH2_MSG_DISCONNECT:
1018 /* log reason code in disconnect message */
1020 int reason = GET_32BIT(ssh->pktin.data + 6);
1021 unsigned msglen = GET_32BIT(ssh->pktin.data + 10);
1023 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
1024 sprintf(buf, "Received disconnect message (%s)",
1025 ssh2_disconnect_reasons[reason]);
1027 sprintf(buf, "Received disconnect message (unknown type %d)",
1031 strcpy(buf, "Disconnection message text: ");
1032 nowlen = strlen(buf);
1033 if (msglen > sizeof(buf) - nowlen - 1)
1034 msglen = sizeof(buf) - nowlen - 1;
1035 memcpy(buf + nowlen, ssh->pktin.data + 14, msglen);
1036 buf[nowlen + msglen] = '\0';
1038 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
1040 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
1041 ssh2_disconnect_reasons[reason] : "unknown",
1046 case SSH2_MSG_IGNORE:
1048 case SSH2_MSG_DEBUG:
1050 /* log the debug message */
1052 /* int display = ssh->pktin.body[6]; */
1053 int stringlen = GET_32BIT(ssh->pktin.data+7);
1055 strcpy(buf, "Remote debug message: ");
1056 prefix = strlen(buf);
1057 if (stringlen > (int)(sizeof(buf)-prefix-1))
1058 stringlen = sizeof(buf)-prefix-1;
1059 memcpy(buf + prefix, ssh->pktin.data + 11, stringlen);
1060 buf[prefix + stringlen] = '\0';
1063 goto next_packet; /* FIXME: print the debug message */
1066 * These packets we need do nothing about here.
1068 case SSH2_MSG_UNIMPLEMENTED:
1069 case SSH2_MSG_SERVICE_REQUEST:
1070 case SSH2_MSG_SERVICE_ACCEPT:
1071 case SSH2_MSG_KEXINIT:
1072 case SSH2_MSG_NEWKEYS:
1073 case SSH2_MSG_KEXDH_INIT:
1074 case SSH2_MSG_KEXDH_REPLY:
1075 /* case SSH2_MSG_KEX_DH_GEX_REQUEST: duplicate case value */
1076 /* case SSH2_MSG_KEX_DH_GEX_GROUP: duplicate case value */
1077 case SSH2_MSG_KEX_DH_GEX_INIT:
1078 case SSH2_MSG_KEX_DH_GEX_REPLY:
1079 case SSH2_MSG_USERAUTH_REQUEST:
1080 case SSH2_MSG_USERAUTH_FAILURE:
1081 case SSH2_MSG_USERAUTH_SUCCESS:
1082 case SSH2_MSG_USERAUTH_BANNER:
1083 case SSH2_MSG_USERAUTH_PK_OK:
1084 /* case SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ: duplicate case value */
1085 /* case SSH2_MSG_USERAUTH_INFO_REQUEST: duplicate case value */
1086 case SSH2_MSG_USERAUTH_INFO_RESPONSE:
1087 case SSH2_MSG_GLOBAL_REQUEST:
1088 case SSH2_MSG_REQUEST_SUCCESS:
1089 case SSH2_MSG_REQUEST_FAILURE:
1090 case SSH2_MSG_CHANNEL_OPEN:
1091 case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
1092 case SSH2_MSG_CHANNEL_OPEN_FAILURE:
1093 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1094 case SSH2_MSG_CHANNEL_DATA:
1095 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1096 case SSH2_MSG_CHANNEL_EOF:
1097 case SSH2_MSG_CHANNEL_CLOSE:
1098 case SSH2_MSG_CHANNEL_REQUEST:
1099 case SSH2_MSG_CHANNEL_SUCCESS:
1100 case SSH2_MSG_CHANNEL_FAILURE:
1104 * For anything else we send SSH2_MSG_UNIMPLEMENTED.
1107 ssh2_pkt_init(ssh, SSH2_MSG_UNIMPLEMENTED);
1108 ssh2_pkt_adduint32(ssh, st->incoming_sequence - 1);
1116 static void ssh1_pktout_size(Ssh ssh, int len)
1120 len += 5; /* type and CRC */
1121 pad = 8 - (len % 8);
1124 ssh->pktout.length = len - 5;
1125 if (ssh->pktout.maxlen < biglen) {
1126 ssh->pktout.maxlen = biglen;
1128 /* Allocate enough buffer space for extra block
1129 * for MS CryptEncrypt() */
1130 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 12);
1132 ssh->pktout.data = srealloc(ssh->pktout.data, biglen + 4);
1135 ssh->pktout.body = ssh->pktout.data + 4 + pad + 1;
1138 static void s_wrpkt_start(Ssh ssh, int type, int len)
1140 ssh1_pktout_size(ssh, len);
1141 ssh->pktout.type = type;
1144 static int s_wrpkt_prepare(Ssh ssh)
1146 int pad, len, biglen, i;
1149 ssh->pktout.body[-1] = ssh->pktout.type;
1151 log_packet(PKT_OUTGOING, ssh->pktout.type, ssh1_pkt_type(ssh->pktout.type),
1152 ssh->pktout.body, ssh->pktout.length);
1154 if (ssh->v1_compressing) {
1155 unsigned char *compblk;
1157 zlib_compress_block(ssh->pktout.body - 1, ssh->pktout.length + 1,
1158 &compblk, &complen);
1159 ssh1_pktout_size(ssh, complen - 1);
1160 memcpy(ssh->pktout.body - 1, compblk, complen);
1164 len = ssh->pktout.length + 5; /* type and CRC */
1165 pad = 8 - (len % 8);
1168 for (i = 0; i < pad; i++)
1169 ssh->pktout.data[i + 4] = random_byte();
1170 crc = crc32(ssh->pktout.data + 4, biglen - 4);
1171 PUT_32BIT(ssh->pktout.data + biglen, crc);
1172 PUT_32BIT(ssh->pktout.data, len);
1175 ssh->cipher->encrypt(ssh->pktout.data + 4, biglen);
1180 static void s_wrpkt(Ssh ssh)
1183 len = s_wrpkt_prepare(ssh);
1184 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1185 if (backlog > SSH_MAX_BACKLOG)
1186 ssh_throttle_all(ssh, 1, backlog);
1189 static void s_wrpkt_defer(Ssh ssh)
1192 len = s_wrpkt_prepare(ssh);
1193 if (ssh->deferred_len + len > ssh->deferred_size) {
1194 ssh->deferred_size = ssh->deferred_len + len + 128;
1195 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1196 ssh->deferred_size);
1198 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1199 ssh->deferred_len += len;
1203 * Construct a packet with the specified contents.
1205 static void construct_packet(Ssh ssh, int pkttype, va_list ap1, va_list ap2)
1207 unsigned char *p, *argp, argchar;
1208 unsigned long argint;
1209 int pktlen, argtype, arglen;
1213 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1216 (void) va_arg(ap1, int);
1220 (void) va_arg(ap1, char);
1224 (void) va_arg(ap1, unsigned char *);
1225 arglen = va_arg(ap1, int);
1229 argp = va_arg(ap1, unsigned char *);
1230 arglen = strlen(argp);
1231 pktlen += 4 + arglen;
1234 bn = va_arg(ap1, Bignum);
1235 pktlen += ssh1_bignum_length(bn);
1242 s_wrpkt_start(ssh, pkttype, pktlen);
1243 p = ssh->pktout.body;
1245 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1248 argint = va_arg(ap2, int);
1249 PUT_32BIT(p, argint);
1253 argchar = va_arg(ap2, unsigned char);
1258 argp = va_arg(ap2, unsigned char *);
1259 arglen = va_arg(ap2, int);
1260 memcpy(p, argp, arglen);
1264 argp = va_arg(ap2, unsigned char *);
1265 arglen = strlen(argp);
1266 PUT_32BIT(p, arglen);
1267 memcpy(p + 4, argp, arglen);
1271 bn = va_arg(ap2, Bignum);
1272 p += ssh1_write_bignum(p, bn);
1278 static void send_packet(Ssh ssh, int pkttype, ...)
1281 va_start(ap1, pkttype);
1282 va_start(ap2, pkttype);
1283 construct_packet(ssh, pkttype, ap1, ap2);
1287 static void defer_packet(Ssh ssh, int pkttype, ...)
1290 va_start(ap1, pkttype);
1291 va_start(ap2, pkttype);
1292 construct_packet(ssh, pkttype, ap1, ap2);
1296 static int ssh_versioncmp(char *a, char *b)
1299 unsigned long av, bv;
1301 av = strtoul(a, &ae, 10);
1302 bv = strtoul(b, &be, 10);
1304 return (av < bv ? -1 : +1);
1309 av = strtoul(ae, &ae, 10);
1310 bv = strtoul(be, &be, 10);
1312 return (av < bv ? -1 : +1);
1317 * Utility routines for putting an SSH-protocol `string' and
1318 * `uint32' into a SHA state.
1321 static void sha_string(SHA_State * s, void *str, int len)
1323 unsigned char lenblk[4];
1324 PUT_32BIT(lenblk, len);
1325 SHA_Bytes(s, lenblk, 4);
1326 SHA_Bytes(s, str, len);
1329 static void sha_uint32(SHA_State * s, unsigned i)
1331 unsigned char intblk[4];
1332 PUT_32BIT(intblk, i);
1333 SHA_Bytes(s, intblk, 4);
1337 * SSH2 packet construction functions.
1339 static void ssh2_pkt_ensure(Ssh ssh, int length)
1341 if (ssh->pktout.maxlen < length) {
1342 ssh->pktout.maxlen = length + 256;
1343 ssh->pktout.data = srealloc(ssh->pktout.data,
1344 ssh->pktout.maxlen + APIEXTRA);
1345 if (!ssh->pktout.data)
1346 fatalbox("Out of memory");
1349 static void ssh2_pkt_adddata(Ssh ssh, void *data, int len)
1351 ssh->pktout.length += len;
1352 ssh2_pkt_ensure(ssh, ssh->pktout.length);
1353 memcpy(ssh->pktout.data + ssh->pktout.length - len, data, len);
1355 static void ssh2_pkt_addbyte(Ssh ssh, unsigned char byte)
1357 ssh2_pkt_adddata(ssh, &byte, 1);
1359 static void ssh2_pkt_init(Ssh ssh, int pkt_type)
1361 ssh->pktout.length = 5;
1362 ssh2_pkt_addbyte(ssh, (unsigned char) pkt_type);
1364 static void ssh2_pkt_addbool(Ssh ssh, unsigned char value)
1366 ssh2_pkt_adddata(ssh, &value, 1);
1368 static void ssh2_pkt_adduint32(Ssh ssh, unsigned long value)
1371 PUT_32BIT(x, value);
1372 ssh2_pkt_adddata(ssh, x, 4);
1374 static void ssh2_pkt_addstring_start(Ssh ssh)
1376 ssh2_pkt_adduint32(ssh, 0);
1377 ssh->pktout.savedpos = ssh->pktout.length;
1379 static void ssh2_pkt_addstring_str(Ssh ssh, char *data)
1381 ssh2_pkt_adddata(ssh, data, strlen(data));
1382 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1383 ssh->pktout.length - ssh->pktout.savedpos);
1385 static void ssh2_pkt_addstring_data(Ssh ssh, char *data, int len)
1387 ssh2_pkt_adddata(ssh, data, len);
1388 PUT_32BIT(ssh->pktout.data + ssh->pktout.savedpos - 4,
1389 ssh->pktout.length - ssh->pktout.savedpos);
1391 static void ssh2_pkt_addstring(Ssh ssh, char *data)
1393 ssh2_pkt_addstring_start(ssh);
1394 ssh2_pkt_addstring_str(ssh, data);
1396 static char *ssh2_mpint_fmt(Bignum b, int *len)
1399 int i, n = (bignum_bitcount(b) + 7) / 8;
1402 fatalbox("out of memory");
1404 for (i = 1; i <= n; i++)
1405 p[i] = bignum_byte(b, n - i);
1407 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1409 memmove(p, p + i, n + 1 - i);
1413 static void ssh2_pkt_addmp(Ssh ssh, Bignum b)
1417 p = ssh2_mpint_fmt(b, &len);
1418 ssh2_pkt_addstring_start(ssh);
1419 ssh2_pkt_addstring_data(ssh, p, len);
1424 * Construct an SSH2 final-form packet: compress it, encrypt it,
1425 * put the MAC on it. Final packet, ready to be sent, is stored in
1426 * ssh->pktout.data. Total length is returned.
1428 static int ssh2_pkt_construct(Ssh ssh)
1430 int cipherblk, maclen, padding, i;
1432 log_packet(PKT_OUTGOING, ssh->pktout.data[5],
1433 ssh2_pkt_type(ssh->pkt_ctx, ssh->pktout.data[5]),
1434 ssh->pktout.data + 6, ssh->pktout.length - 6);
1437 * Compress packet payload.
1440 unsigned char *newpayload;
1443 ssh->cscomp->compress(ssh->pktout.data + 5, ssh->pktout.length - 5,
1444 &newpayload, &newlen)) {
1445 ssh->pktout.length = 5;
1446 ssh2_pkt_adddata(ssh, newpayload, newlen);
1452 * Add padding. At least four bytes, and must also bring total
1453 * length (minus MAC) up to a multiple of the block size.
1455 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1456 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1459 (cipherblk - (ssh->pktout.length + padding) % cipherblk) % cipherblk;
1460 maclen = ssh->csmac ? ssh->csmac->len : 0;
1461 ssh2_pkt_ensure(ssh, ssh->pktout.length + padding + maclen);
1462 ssh->pktout.data[4] = padding;
1463 for (i = 0; i < padding; i++)
1464 ssh->pktout.data[ssh->pktout.length + i] = random_byte();
1465 PUT_32BIT(ssh->pktout.data, ssh->pktout.length + padding - 4);
1467 ssh->csmac->generate(ssh->pktout.data, ssh->pktout.length + padding,
1468 ssh->v2_outgoing_sequence);
1469 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1472 ssh->cscipher->encrypt(ssh->pktout.data, ssh->pktout.length + padding);
1474 /* Ready-to-send packet starts at ssh->pktout.data. We return length. */
1475 return ssh->pktout.length + padding + maclen;
1479 * Construct and send an SSH2 packet immediately.
1481 static void ssh2_pkt_send(Ssh ssh)
1485 len = ssh2_pkt_construct(ssh);
1486 backlog = sk_write(ssh->s, ssh->pktout.data, len);
1487 if (backlog > SSH_MAX_BACKLOG)
1488 ssh_throttle_all(ssh, 1, backlog);
1492 * Construct an SSH2 packet and add it to a deferred data block.
1493 * Useful for sending multiple packets in a single sk_write() call,
1494 * to prevent a traffic-analysing listener from being able to work
1495 * out the length of any particular packet (such as the password
1498 * Note that because SSH2 sequence-numbers its packets, this can
1499 * NOT be used as an m4-style `defer' allowing packets to be
1500 * constructed in one order and sent in another.
1502 static void ssh2_pkt_defer(Ssh ssh)
1504 int len = ssh2_pkt_construct(ssh);
1505 if (ssh->deferred_len + len > ssh->deferred_size) {
1506 ssh->deferred_size = ssh->deferred_len + len + 128;
1507 ssh->deferred_send_data = srealloc(ssh->deferred_send_data,
1508 ssh->deferred_size);
1510 memcpy(ssh->deferred_send_data + ssh->deferred_len, ssh->pktout.data, len);
1511 ssh->deferred_len += len;
1515 * Send the whole deferred data block constructed by
1516 * ssh2_pkt_defer() or SSH1's defer_packet().
1518 static void ssh_pkt_defersend(Ssh ssh)
1521 backlog = sk_write(ssh->s, ssh->deferred_send_data, ssh->deferred_len);
1522 ssh->deferred_len = ssh->deferred_size = 0;
1523 sfree(ssh->deferred_send_data);
1524 ssh->deferred_send_data = NULL;
1525 if (backlog > SSH_MAX_BACKLOG)
1526 ssh_throttle_all(ssh, 1, backlog);
1530 void bndebug(char *string, Bignum b)
1534 p = ssh2_mpint_fmt(b, &len);
1535 debug(("%s", string));
1536 for (i = 0; i < len; i++)
1537 debug((" %02x", p[i]));
1543 static void sha_mpint(SHA_State * s, Bignum b)
1547 p = ssh2_mpint_fmt(b, &len);
1548 sha_string(s, p, len);
1553 * SSH2 packet decode functions.
1555 static unsigned long ssh2_pkt_getuint32(Ssh ssh)
1557 unsigned long value;
1558 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1559 return 0; /* arrgh, no way to decline (FIXME?) */
1560 value = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1561 ssh->pktin.savedpos += 4;
1564 static int ssh2_pkt_getbool(Ssh ssh)
1566 unsigned long value;
1567 if (ssh->pktin.length - ssh->pktin.savedpos < 1)
1568 return 0; /* arrgh, no way to decline (FIXME?) */
1569 value = ssh->pktin.data[ssh->pktin.savedpos] != 0;
1570 ssh->pktin.savedpos++;
1573 static void ssh2_pkt_getstring(Ssh ssh, char **p, int *length)
1577 if (ssh->pktin.length - ssh->pktin.savedpos < 4)
1579 *length = GET_32BIT(ssh->pktin.data + ssh->pktin.savedpos);
1580 ssh->pktin.savedpos += 4;
1581 if (ssh->pktin.length - ssh->pktin.savedpos < *length)
1583 *p = ssh->pktin.data + ssh->pktin.savedpos;
1584 ssh->pktin.savedpos += *length;
1586 static Bignum ssh2_pkt_getmp(Ssh ssh)
1592 ssh2_pkt_getstring(ssh, &p, &length);
1596 bombout(("internal error: Can't handle negative mpints"));
1599 b = bignum_from_bytes(p, length);
1604 * Helper function to add an SSH2 signature blob to a packet.
1605 * Expects to be shown the public key blob as well as the signature
1606 * blob. Normally works just like ssh2_pkt_addstring, but will
1607 * fiddle with the signature packet if necessary for
1608 * BUG_SSH2_RSA_PADDING.
1610 static void ssh2_add_sigblob(Ssh ssh, void *pkblob_v, int pkblob_len,
1611 void *sigblob_v, int sigblob_len)
1613 unsigned char *pkblob = (unsigned char *)pkblob_v;
1614 unsigned char *sigblob = (unsigned char *)sigblob_v;
1616 /* dmemdump(pkblob, pkblob_len); */
1617 /* dmemdump(sigblob, sigblob_len); */
1620 * See if this is in fact an ssh-rsa signature and a buggy
1621 * server; otherwise we can just do this the easy way.
1623 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1624 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1625 int pos, len, siglen;
1628 * Find the byte length of the modulus.
1631 pos = 4+7; /* skip over "ssh-rsa" */
1632 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1633 len = GET_32BIT(pkblob+pos); /* find length of modulus */
1634 pos += 4; /* find modulus itself */
1635 while (len > 0 && pkblob[pos] == 0)
1637 /* debug(("modulus length is %d\n", len)); */
1640 * Now find the signature integer.
1642 pos = 4+7; /* skip over "ssh-rsa" */
1643 siglen = GET_32BIT(sigblob+pos);
1644 /* debug(("signature length is %d\n", siglen)); */
1646 if (len != siglen) {
1647 unsigned char newlen[4];
1648 ssh2_pkt_addstring_start(ssh);
1649 ssh2_pkt_addstring_data(ssh, sigblob, pos);
1650 /* dmemdump(sigblob, pos); */
1651 pos += 4; /* point to start of actual sig */
1652 PUT_32BIT(newlen, len);
1653 ssh2_pkt_addstring_data(ssh, newlen, 4);
1654 /* dmemdump(newlen, 4); */
1656 while (len-- > siglen) {
1657 ssh2_pkt_addstring_data(ssh, newlen, 1);
1658 /* dmemdump(newlen, 1); */
1660 ssh2_pkt_addstring_data(ssh, sigblob+pos, siglen);
1661 /* dmemdump(sigblob+pos, siglen); */
1665 /* Otherwise fall through and do it the easy way. */
1668 ssh2_pkt_addstring_start(ssh);
1669 ssh2_pkt_addstring_data(ssh, sigblob, sigblob_len);
1673 * Examine the remote side's version string and compare it against
1674 * a list of known buggy implementations.
1676 static void ssh_detect_bugs(Ssh ssh, char *vstring)
1678 char *imp; /* pointer to implementation part */
1680 imp += strcspn(imp, "-");
1682 imp += strcspn(imp, "-");
1685 ssh->remote_bugs = 0;
1687 if (cfg.sshbug_ignore1 == BUG_ON ||
1688 (cfg.sshbug_ignore1 == BUG_AUTO &&
1689 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
1690 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
1691 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25")))) {
1693 * These versions don't support SSH1_MSG_IGNORE, so we have
1694 * to use a different defence against password length
1697 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
1698 logevent("We believe remote version has SSH1 ignore bug");
1701 if (cfg.sshbug_plainpw1 == BUG_ON ||
1702 (cfg.sshbug_plainpw1 == BUG_AUTO &&
1703 (!strcmp(imp, "Cisco-1.25")))) {
1705 * These versions need a plain password sent; they can't
1706 * handle having a null and a random length of data after
1709 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
1710 logevent("We believe remote version needs a plain SSH1 password");
1713 if (cfg.sshbug_rsa1 == BUG_ON ||
1714 (cfg.sshbug_rsa1 == BUG_AUTO &&
1715 (!strcmp(imp, "Cisco-1.25")))) {
1717 * These versions apparently have no clue whatever about
1718 * RSA authentication and will panic and die if they see
1719 * an AUTH_RSA message.
1721 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
1722 logevent("We believe remote version can't handle RSA authentication");
1725 if (cfg.sshbug_hmac2 == BUG_ON ||
1726 (cfg.sshbug_hmac2 == BUG_AUTO &&
1727 (!strncmp(imp, "2.1.0", 5) || !strncmp(imp, "2.0.", 4) ||
1728 !strncmp(imp, "2.2.0", 5) || !strncmp(imp, "2.3.0", 5) ||
1729 !strncmp(imp, "2.1 ", 4)))) {
1731 * These versions have the HMAC bug.
1733 ssh->remote_bugs |= BUG_SSH2_HMAC;
1734 logevent("We believe remote version has SSH2 HMAC bug");
1737 if (cfg.sshbug_derivekey2 == BUG_ON ||
1738 (cfg.sshbug_derivekey2 == BUG_AUTO &&
1739 (!strncmp(imp, "2.0.", 4)))) {
1741 * These versions have the key-derivation bug (failing to
1742 * include the literal shared secret in the hashes that
1743 * generate the keys).
1745 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
1746 logevent("We believe remote version has SSH2 key-derivation bug");
1749 if (cfg.sshbug_rsapad2 == BUG_ON ||
1750 (cfg.sshbug_rsapad2 == BUG_AUTO &&
1751 ((!strncmp(imp, "OpenSSH_2.", 10) && imp[10]>='5' && imp[10]<='9') ||
1752 (!strncmp(imp, "OpenSSH_3.", 10) && imp[10]>='0' && imp[10]<='2')))){
1754 * These versions have the SSH2 RSA padding bug.
1756 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
1757 logevent("We believe remote version has SSH2 RSA padding bug");
1760 if (cfg.sshbug_dhgex2 == BUG_ON) {
1762 * These versions have the SSH2 DH GEX bug.
1764 ssh->remote_bugs |= BUG_SSH2_DH_GEX;
1765 logevent("We believe remote version has SSH2 DH group exchange bug");
1769 static int do_ssh_init(Ssh ssh, unsigned char c)
1771 struct do_ssh_init_state {
1779 crState(do_ssh_init_state);
1781 crBegin(ssh->do_ssh_init_crstate);
1783 /* Search for the string "SSH-" in the input. */
1786 static const int transS[] = { 1, 2, 2, 1 };
1787 static const int transH[] = { 0, 0, 3, 0 };
1788 static const int transminus[] = { 0, 0, 0, -1 };
1790 s->i = transS[s->i];
1792 s->i = transH[s->i];
1794 s->i = transminus[s->i];
1799 crReturn(1); /* get another character */
1803 s->vstring = smalloc(s->vstrsize);
1804 strcpy(s->vstring, "SSH-");
1808 crReturn(1); /* get another char */
1809 if (s->vslen >= s->vstrsize - 1) {
1811 s->vstring = srealloc(s->vstring, s->vstrsize);
1813 s->vstring[s->vslen++] = c;
1816 s->version[s->i] = '\0';
1818 } else if (s->i < sizeof(s->version) - 1)
1819 s->version[s->i++] = c;
1820 } else if (c == '\n')
1824 ssh->agentfwd_enabled = FALSE;
1825 ssh->rdpkt2_state.incoming_sequence = 0;
1827 s->vstring[s->vslen] = 0;
1828 s->vstring[strcspn(s->vstring, "\r\n")] = '\0';/* remove EOL chars */
1831 vlog = smalloc(20 + s->vslen);
1832 sprintf(vlog, "Server version: %s", s->vstring);
1836 ssh_detect_bugs(ssh, s->vstring);
1839 * Decide which SSH protocol version to support.
1842 /* Anything strictly below "2.0" means protocol 1 is supported. */
1843 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
1844 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
1845 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
1847 if (cfg.sshprot == 0 && !s->proto1) {
1848 bombout(("SSH protocol version 1 required by user but not provided by server"));
1851 if (cfg.sshprot == 3 && !s->proto2) {
1852 bombout(("SSH protocol version 2 required by user but not provided by server"));
1856 if (s->proto2 && (cfg.sshprot >= 2 || !s->proto1)) {
1860 char verstring[80], vlog[100];
1861 sprintf(verstring, "SSH-2.0-%s", sshver);
1862 SHA_Init(&ssh->exhashbase);
1864 * Hash our version string and their version string.
1866 sha_string(&ssh->exhashbase, verstring, strlen(verstring));
1867 sha_string(&ssh->exhashbase, s->vstring, strcspn(s->vstring, "\r\n"));
1868 sprintf(vlog, "We claim version: %s", verstring);
1870 strcat(verstring, "\n");
1871 logevent("Using SSH protocol version 2");
1872 sk_write(ssh->s, verstring, strlen(verstring));
1873 ssh->protocol = ssh2_protocol;
1875 ssh->s_rdpkt = ssh2_rdpkt;
1880 char verstring[80], vlog[100];
1881 sprintf(verstring, "SSH-%s-%s",
1882 (ssh_versioncmp(s->version, "1.5") <= 0 ? s->version : "1.5"),
1884 sprintf(vlog, "We claim version: %s", verstring);
1886 strcat(verstring, "\n");
1888 logevent("Using SSH protocol version 1");
1889 sk_write(ssh->s, verstring, strlen(verstring));
1890 ssh->protocol = ssh1_protocol;
1892 ssh->s_rdpkt = ssh1_rdpkt;
1894 ssh->state = SSH_STATE_BEFORE_SIZE;
1901 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
1903 crBegin(ssh->ssh_gotdata_crstate);
1906 * To begin with, feed the characters one by one to the
1907 * protocol initialisation / selection function do_ssh_init().
1908 * When that returns 0, we're done with the initial greeting
1909 * exchange and can move on to packet discipline.
1912 int ret; /* need not be kept across crReturn */
1914 crReturnV; /* more data please */
1915 ret = do_ssh_init(ssh, *data);
1923 * We emerge from that loop when the initial negotiation is
1924 * over and we have selected an s_rdpkt function. Now pass
1925 * everything to s_rdpkt, and then pass the resulting packets
1926 * to the proper protocol handler.
1931 while (datalen > 0) {
1932 if (ssh->s_rdpkt(ssh, &data, &datalen) == 0) {
1933 if (ssh->state == SSH_STATE_CLOSED) {
1936 ssh->protocol(ssh, NULL, 0, 1);
1937 if (ssh->state == SSH_STATE_CLOSED) {
1947 static int ssh_closing(Plug plug, char *error_msg, int error_code,
1950 Ssh ssh = (Ssh) plug;
1951 ssh->state = SSH_STATE_CLOSED;
1957 /* A socket error has occurred. */
1958 logevent(error_msg);
1959 connection_fatal(error_msg);
1961 /* Otherwise, the remote side closed the connection normally. */
1966 static int ssh_receive(Plug plug, int urgent, char *data, int len)
1968 Ssh ssh = (Ssh) plug;
1969 ssh_gotdata(ssh, data, len);
1970 if (ssh->state == SSH_STATE_CLOSED) {
1980 static void ssh_sent(Plug plug, int bufsize)
1982 Ssh ssh = (Ssh) plug;
1984 * If the send backlog on the SSH socket itself clears, we
1985 * should unthrottle the whole world if it was throttled.
1987 if (bufsize < SSH_MAX_BACKLOG)
1988 ssh_throttle_all(ssh, 0, bufsize);
1992 * Connect to specified host and port.
1993 * Returns an error message, or NULL on success.
1994 * Also places the canonical host name into `realhost'. It must be
1995 * freed by the caller.
1997 static char *connect_to_host(Ssh ssh, char *host, int port,
1998 char **realhost, int nodelay)
2000 static const struct plug_function_table fn_table = {
2010 ssh->savedhost = smalloc(1 + strlen(host));
2011 if (!ssh->savedhost)
2012 fatalbox("Out of memory");
2013 strcpy(ssh->savedhost, host);
2016 port = 22; /* default ssh port */
2017 ssh->savedport = port;
2024 sprintf(buf, "Looking up host \"%.170s\"", host);
2027 addr = sk_namelookup(host, realhost);
2028 if ((err = sk_addr_error(addr)))
2035 char buf[200], addrbuf[100];
2036 sk_getaddr(addr, addrbuf, 100);
2037 sprintf(buf, "Connecting to %.100s port %d", addrbuf, port);
2040 ssh->fn = &fn_table;
2041 ssh->s = new_connection(addr, *realhost, port, 0, 1, nodelay, (Plug) ssh);
2042 if ((err = sk_socket_error(ssh->s))) {
2051 * Throttle or unthrottle the SSH connection.
2053 static void ssh1_throttle(Ssh ssh, int adjust)
2055 int old_count = ssh->v1_throttle_count;
2056 ssh->v1_throttle_count += adjust;
2057 assert(ssh->v1_throttle_count >= 0);
2058 if (ssh->v1_throttle_count && !old_count) {
2059 sk_set_frozen(ssh->s, 1);
2060 } else if (!ssh->v1_throttle_count && old_count) {
2061 sk_set_frozen(ssh->s, 0);
2066 * Throttle or unthrottle _all_ local data streams (for when sends
2067 * on the SSH connection itself back up).
2069 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2072 struct ssh_channel *c;
2074 if (enable == ssh->throttled_all)
2076 ssh->throttled_all = enable;
2077 ssh->overall_bufsize = bufsize;
2080 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2082 case CHAN_MAINSESSION:
2084 * This is treated separately, outside the switch.
2088 x11_override_throttle(c->u.x11.s, enable);
2091 /* Agent channels require no buffer management. */
2094 pfd_override_throttle(c->u.x11.s, enable);
2101 * Username and password input, abstracted off into routines
2102 * reusable in several places - even between SSH1 and SSH2.
2105 /* Set up a username or password input loop on a given buffer. */
2106 void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2108 ssh->userpass_input_buffer = buffer;
2109 ssh->userpass_input_buflen = buflen;
2110 ssh->userpass_input_bufpos = 0;
2111 ssh->userpass_input_echo = echo;
2115 * Process some terminal data in the course of username/password
2116 * input. Returns >0 for success (line of input returned in
2117 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2118 * for inconclusive (keep waiting for more input please).
2120 int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2125 switch (c = *in++) {
2128 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2129 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2134 if (ssh->userpass_input_bufpos > 0) {
2135 if (ssh->userpass_input_echo)
2136 c_write_str(ssh, "\b \b");
2137 ssh->userpass_input_bufpos--;
2142 while (ssh->userpass_input_bufpos > 0) {
2143 if (ssh->userpass_input_echo)
2144 c_write_str(ssh, "\b \b");
2145 ssh->userpass_input_bufpos--;
2153 if (((c >= ' ' && c <= '~') ||
2154 ((unsigned char) c >= 160))
2155 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2156 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2157 if (ssh->userpass_input_echo)
2158 c_write(ssh, &c, 1);
2167 * Handle the key exchange and user authentication phases.
2169 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2172 unsigned char cookie[8];
2173 struct RSAKey servkey, hostkey;
2174 struct MD5Context md5c;
2175 struct do_ssh1_login_state {
2177 unsigned char *rsabuf, *keystr1, *keystr2;
2178 unsigned long supported_ciphers_mask, supported_auths_mask;
2179 int tried_publickey, tried_agent;
2180 int tis_auth_refused, ccard_auth_refused;
2181 unsigned char session_id[16];
2184 void *publickey_blob;
2185 int publickey_bloblen;
2191 unsigned char request[5], *response, *p;
2200 crState(do_ssh1_login_state);
2202 crBegin(ssh->do_ssh1_login_crstate);
2207 if (ssh->pktin.type != SSH1_SMSG_PUBLIC_KEY) {
2208 bombout(("Public key packet not received"));
2212 logevent("Received public keys");
2214 memcpy(cookie, ssh->pktin.body, 8);
2216 i = makekey(ssh->pktin.body + 8, &servkey, &s->keystr1, 0);
2217 j = makekey(ssh->pktin.body + 8 + i, &hostkey, &s->keystr2, 0);
2220 * Log the host key fingerprint.
2224 logevent("Host key fingerprint is:");
2225 strcpy(logmsg, " ");
2226 hostkey.comment = NULL;
2227 rsa_fingerprint(logmsg + strlen(logmsg),
2228 sizeof(logmsg) - strlen(logmsg), &hostkey);
2232 ssh->v1_remote_protoflags = GET_32BIT(ssh->pktin.body + 8 + i + j);
2233 s->supported_ciphers_mask = GET_32BIT(ssh->pktin.body + 12 + i + j);
2234 s->supported_auths_mask = GET_32BIT(ssh->pktin.body + 16 + i + j);
2236 ssh->v1_local_protoflags =
2237 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2238 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2241 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2242 MD5Update(&md5c, s->keystr1, servkey.bytes);
2243 MD5Update(&md5c, ssh->pktin.body, 8);
2244 MD5Final(s->session_id, &md5c);
2246 for (i = 0; i < 32; i++)
2247 ssh->session_key[i] = random_byte();
2249 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2251 s->rsabuf = smalloc(s->len);
2253 fatalbox("Out of memory");
2256 * Verify the host key.
2260 * First format the key into a string.
2262 int len = rsastr_len(&hostkey);
2263 char fingerprint[100];
2264 char *keystr = smalloc(len);
2266 fatalbox("Out of memory");
2267 rsastr_fmt(keystr, &hostkey);
2268 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2269 verify_ssh_host_key(ssh->savedhost, ssh->savedport, "rsa", keystr,
2274 for (i = 0; i < 32; i++) {
2275 s->rsabuf[i] = ssh->session_key[i];
2277 s->rsabuf[i] ^= s->session_id[i];
2280 if (hostkey.bytes > servkey.bytes) {
2281 rsaencrypt(s->rsabuf, 32, &servkey);
2282 rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2284 rsaencrypt(s->rsabuf, 32, &hostkey);
2285 rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2288 logevent("Encrypted session key");
2291 int cipher_chosen = 0, warn = 0;
2292 char *cipher_string = NULL;
2294 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2295 int next_cipher = cfg.ssh_cipherlist[i];
2296 if (next_cipher == CIPHER_WARN) {
2297 /* If/when we choose a cipher, warn about it */
2299 } else if (next_cipher == CIPHER_AES) {
2300 /* XXX Probably don't need to mention this. */
2301 logevent("AES not supported in SSH1, skipping");
2303 switch (next_cipher) {
2304 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2305 cipher_string = "3DES"; break;
2306 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2307 cipher_string = "Blowfish"; break;
2308 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2309 cipher_string = "single-DES"; break;
2311 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2315 if (!cipher_chosen) {
2316 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2317 bombout(("Server violates SSH 1 protocol by not "
2318 "supporting 3DES encryption"));
2320 /* shouldn't happen */
2321 bombout(("No supported ciphers found"));
2325 /* Warn about chosen cipher if necessary. */
2327 askcipher(cipher_string, 0);
2330 switch (s->cipher_type) {
2331 case SSH_CIPHER_3DES:
2332 logevent("Using 3DES encryption");
2334 case SSH_CIPHER_DES:
2335 logevent("Using single-DES encryption");
2337 case SSH_CIPHER_BLOWFISH:
2338 logevent("Using Blowfish encryption");
2342 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2343 PKT_CHAR, s->cipher_type,
2344 PKT_DATA, cookie, 8,
2345 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2346 PKT_DATA, s->rsabuf, s->len,
2347 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2349 logevent("Trying to enable encryption...");
2353 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2354 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2356 ssh->cipher->sesskey(ssh->session_key);
2360 if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2361 bombout(("Encryption not successfully enabled"));
2365 logevent("Successfully started encryption");
2369 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
2370 if (ssh_get_line && !ssh_getline_pw_only) {
2371 if (!ssh_get_line("login as: ",
2372 s->username, sizeof(s->username), FALSE)) {
2374 * get_line failed to get a username.
2377 logevent("No username provided. Abandoning session.");
2378 ssh->state = SSH_STATE_CLOSED;
2382 int ret; /* need not be kept over crReturn */
2383 c_write_str(ssh, "login as: ");
2386 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2388 crWaitUntil(!ispkt);
2389 ret = process_userpass_input(ssh, in, inlen);
2393 c_write_str(ssh, "\r\n");
2396 strncpy(s->username, cfg.username, sizeof(s->username));
2397 s->username[sizeof(s->username)-1] = '\0';
2400 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2402 char userlog[22 + sizeof(s->username)];
2403 sprintf(userlog, "Sent username \"%s\"", s->username);
2405 if (flags & FLAG_INTERACTIVE &&
2406 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2407 strcat(userlog, "\r\n");
2408 c_write_str(ssh, userlog);
2415 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2416 /* We must not attempt PK auth. Pretend we've already tried it. */
2417 s->tried_publickey = s->tried_agent = 1;
2419 s->tried_publickey = s->tried_agent = 0;
2421 s->tis_auth_refused = s->ccard_auth_refused = 0;
2422 /* Load the public half of cfg.keyfile so we notice if it's in Pageant */
2424 if (!rsakey_pubblob(cfg.keyfile,
2425 &s->publickey_blob, &s->publickey_bloblen))
2426 s->publickey_blob = NULL;
2428 s->publickey_blob = NULL;
2430 while (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2431 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2433 if (agent_exists() && !s->tried_agent) {
2435 * Attempt RSA authentication using Pageant.
2441 logevent("Pageant is running. Requesting keys.");
2443 /* Request the keys held by the agent. */
2444 PUT_32BIT(s->request, 1);
2445 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2446 agent_query(s->request, 5, &r, &s->responselen);
2447 s->response = (unsigned char *) r;
2448 if (s->response && s->responselen >= 5 &&
2449 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
2450 s->p = s->response + 5;
2451 s->nkeys = GET_32BIT(s->p);
2455 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
2458 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
2461 sprintf(buf, "Trying Pageant key #%d", s->keyi);
2464 if (s->publickey_blob &&
2465 !memcmp(s->p, s->publickey_blob,
2466 s->publickey_bloblen)) {
2467 logevent("This key matches configured key file");
2468 s->tried_publickey = 1;
2471 s->p += ssh1_read_bignum(s->p, &s->key.exponent);
2472 s->p += ssh1_read_bignum(s->p, &s->key.modulus);
2473 s->commentlen = GET_32BIT(s->p);
2476 s->p += s->commentlen;
2477 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2478 PKT_BIGNUM, s->key.modulus, PKT_END);
2480 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2481 logevent("Key refused");
2484 logevent("Received RSA challenge");
2485 ssh1_read_bignum(ssh->pktin.body, &s->challenge);
2487 char *agentreq, *q, *ret;
2490 len = 1 + 4; /* message type, bit count */
2491 len += ssh1_bignum_length(s->key.exponent);
2492 len += ssh1_bignum_length(s->key.modulus);
2493 len += ssh1_bignum_length(s->challenge);
2494 len += 16; /* session id */
2495 len += 4; /* response format */
2496 agentreq = smalloc(4 + len);
2497 PUT_32BIT(agentreq, len);
2499 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
2500 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
2502 q += ssh1_write_bignum(q, s->key.exponent);
2503 q += ssh1_write_bignum(q, s->key.modulus);
2504 q += ssh1_write_bignum(q, s->challenge);
2505 memcpy(q, s->session_id, 16);
2507 PUT_32BIT(q, 1); /* response format */
2508 agent_query(agentreq, len + 4, &vret, &retlen);
2512 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
2513 logevent("Sending Pageant's response");
2514 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2515 PKT_DATA, ret + 5, 16,
2519 if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
2521 ("Pageant's response accepted");
2522 if (flags & FLAG_VERBOSE) {
2523 c_write_str(ssh, "Authenticated using"
2525 c_write(ssh, s->commentp,
2527 c_write_str(ssh, "\" from agent\r\n");
2532 ("Pageant's response not accepted");
2535 ("Pageant failed to answer challenge");
2539 logevent("No reply received from Pageant");
2542 freebn(s->key.exponent);
2543 freebn(s->key.modulus);
2544 freebn(s->challenge);
2552 if (*cfg.keyfile && !s->tried_publickey)
2553 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
2555 if (cfg.try_tis_auth &&
2556 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
2557 !s->tis_auth_refused) {
2558 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
2559 logevent("Requested TIS authentication");
2560 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
2562 if (ssh->pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
2563 logevent("TIS authentication declined");
2564 if (flags & FLAG_INTERACTIVE)
2565 c_write_str(ssh, "TIS authentication refused.\r\n");
2566 s->tis_auth_refused = 1;
2569 int challengelen = GET_32BIT(ssh->pktin.body);
2570 logevent("Received TIS challenge");
2571 if (challengelen > sizeof(s->prompt) - 1)
2572 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2573 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2574 /* Prompt heuristic comes from OpenSSH */
2575 strncpy(s->prompt + challengelen,
2576 memchr(s->prompt, '\n', challengelen) ?
2577 "": "\r\nResponse: ",
2578 (sizeof s->prompt) - challengelen);
2579 s->prompt[(sizeof s->prompt) - 1] = '\0';
2582 if (cfg.try_tis_auth &&
2583 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
2584 !s->ccard_auth_refused) {
2585 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
2586 logevent("Requested CryptoCard authentication");
2587 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
2589 if (ssh->pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
2590 logevent("CryptoCard authentication declined");
2591 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
2592 s->ccard_auth_refused = 1;
2595 int challengelen = GET_32BIT(ssh->pktin.body);
2596 logevent("Received CryptoCard challenge");
2597 if (challengelen > sizeof(s->prompt) - 1)
2598 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
2599 memcpy(s->prompt, ssh->pktin.body + 4, challengelen);
2600 strncpy(s->prompt + challengelen,
2601 memchr(s->prompt, '\n', challengelen) ?
2602 "" : "\r\nResponse: ",
2603 sizeof(s->prompt) - challengelen);
2604 s->prompt[sizeof(s->prompt) - 1] = '\0';
2607 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2608 sprintf(s->prompt, "%.90s@%.90s's password: ",
2609 s->username, ssh->savedhost);
2611 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2612 char *comment = NULL;
2615 if (flags & FLAG_VERBOSE)
2616 c_write_str(ssh, "Trying public key authentication.\r\n");
2617 sprintf(msgbuf, "Trying public key \"%.200s\"", cfg.keyfile);
2619 type = key_type(cfg.keyfile);
2620 if (type != SSH_KEYTYPE_SSH1) {
2621 sprintf(msgbuf, "Key is of wrong type (%s)",
2622 key_type_to_str(type));
2624 c_write_str(ssh, msgbuf);
2625 c_write_str(ssh, "\r\n");
2626 s->tried_publickey = 1;
2629 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
2630 if (flags & FLAG_VERBOSE)
2631 c_write_str(ssh, "No passphrase required.\r\n");
2634 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
2639 * Show password prompt, having first obtained it via a TIS
2640 * or CryptoCard exchange if we're doing TIS or CryptoCard
2644 if (!ssh_get_line(s->prompt, s->password,
2645 sizeof(s->password), TRUE)) {
2647 * get_line failed to get a password (for example
2648 * because one was supplied on the command line
2649 * which has already failed to work). Terminate.
2651 send_packet(ssh, SSH1_MSG_DISCONNECT,
2652 PKT_STR, "No more passwords available to try",
2654 logevent("Unable to authenticate");
2655 connection_fatal("Unable to authenticate");
2656 ssh->state = SSH_STATE_CLOSED;
2660 /* Prompt may have come from server. We've munged it a bit, so
2661 * we know it to be zero-terminated at least once. */
2662 int ret; /* need not be saved over crReturn */
2663 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
2666 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
2668 crWaitUntil(!ispkt);
2669 ret = process_userpass_input(ssh, in, inlen);
2673 c_write_str(ssh, "\r\n");
2677 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
2679 * Try public key authentication with the specified
2682 s->tried_publickey = 1;
2685 int ret = loadrsakey(cfg.keyfile, &s->key, s->password);
2687 c_write_str(ssh, "Couldn't load private key from ");
2688 c_write_str(ssh, cfg.keyfile);
2689 c_write_str(ssh, ".\r\n");
2690 continue; /* go and try password */
2693 c_write_str(ssh, "Wrong passphrase.\r\n");
2694 s->tried_publickey = 0;
2695 continue; /* try again */
2700 * Send a public key attempt.
2702 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
2703 PKT_BIGNUM, s->key.modulus, PKT_END);
2706 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2707 c_write_str(ssh, "Server refused our public key.\r\n");
2708 continue; /* go and try password */
2710 if (ssh->pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
2711 bombout(("Bizarre response to offer of public key"));
2717 unsigned char buffer[32];
2718 Bignum challenge, response;
2720 ssh1_read_bignum(ssh->pktin.body, &challenge);
2721 response = rsadecrypt(challenge, &s->key);
2722 freebn(s->key.private_exponent);/* burn the evidence */
2724 for (i = 0; i < 32; i++) {
2725 buffer[i] = bignum_byte(response, 31 - i);
2729 MD5Update(&md5c, buffer, 32);
2730 MD5Update(&md5c, s->session_id, 16);
2731 MD5Final(buffer, &md5c);
2733 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
2734 PKT_DATA, buffer, 16, PKT_END);
2741 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2742 if (flags & FLAG_VERBOSE)
2743 c_write_str(ssh, "Failed to authenticate with"
2744 " our public key.\r\n");
2745 continue; /* go and try password */
2746 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2747 bombout(("Bizarre response to RSA authentication response"));
2751 break; /* we're through! */
2753 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
2755 * Defence against traffic analysis: we send a
2756 * whole bunch of packets containing strings of
2757 * different lengths. One of these strings is the
2758 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
2759 * The others are all random data in
2760 * SSH1_MSG_IGNORE packets. This way a passive
2761 * listener can't tell which is the password, and
2762 * hence can't deduce the password length.
2764 * Anybody with a password length greater than 16
2765 * bytes is going to have enough entropy in their
2766 * password that a listener won't find it _that_
2767 * much help to know how long it is. So what we'll
2770 * - if password length < 16, we send 15 packets
2771 * containing string lengths 1 through 15
2773 * - otherwise, we let N be the nearest multiple
2774 * of 8 below the password length, and send 8
2775 * packets containing string lengths N through
2776 * N+7. This won't obscure the order of
2777 * magnitude of the password length, but it will
2778 * introduce a bit of extra uncertainty.
2780 * A few servers (the old 1.2.18 through 1.2.22)
2781 * can't deal with SSH1_MSG_IGNORE. For these
2782 * servers, we need an alternative defence. We make
2783 * use of the fact that the password is interpreted
2784 * as a C string: so we can append a NUL, then some
2787 * One server (a Cisco one) can deal with neither
2788 * SSH1_MSG_IGNORE _nor_ a padded password string.
2789 * For this server we are left with no defences
2790 * against password length sniffing.
2792 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
2794 * The server can deal with SSH1_MSG_IGNORE, so
2795 * we can use the primary defence.
2797 int bottom, top, pwlen, i;
2800 pwlen = strlen(s->password);
2802 bottom = 0; /* zero length passwords are OK! :-) */
2805 bottom = pwlen & ~7;
2809 assert(pwlen >= bottom && pwlen <= top);
2811 randomstr = smalloc(top + 1);
2813 for (i = bottom; i <= top; i++) {
2815 defer_packet(ssh, s->pwpkt_type,
2816 PKT_STR, s->password, PKT_END);
2818 for (j = 0; j < i; j++) {
2820 randomstr[j] = random_byte();
2821 } while (randomstr[j] == '\0');
2823 randomstr[i] = '\0';
2824 defer_packet(ssh, SSH1_MSG_IGNORE,
2825 PKT_STR, randomstr, PKT_END);
2828 logevent("Sending password with camouflage packets");
2829 ssh_pkt_defersend(ssh);
2831 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
2833 * The server can't deal with SSH1_MSG_IGNORE
2834 * but can deal with padded passwords, so we
2835 * can use the secondary defence.
2841 len = strlen(s->password);
2842 if (len < sizeof(string)) {
2844 strcpy(string, s->password);
2845 len++; /* cover the zero byte */
2846 while (len < sizeof(string)) {
2847 string[len++] = (char) random_byte();
2852 logevent("Sending length-padded password");
2853 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2854 PKT_DATA, ss, len, PKT_END);
2857 * The server has _both_
2858 * BUG_CHOKES_ON_SSH1_IGNORE and
2859 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
2860 * therefore nothing we can do.
2863 len = strlen(s->password);
2864 logevent("Sending unpadded password");
2865 send_packet(ssh, s->pwpkt_type, PKT_INT, len,
2866 PKT_DATA, s->password, len, PKT_END);
2869 send_packet(ssh, s->pwpkt_type, PKT_STR, s->password, PKT_END);
2872 logevent("Sent password");
2873 memset(s->password, 0, strlen(s->password));
2875 if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2876 if (flags & FLAG_VERBOSE)
2877 c_write_str(ssh, "Access denied\r\n");
2878 logevent("Authentication refused");
2879 } else if (ssh->pktin.type != SSH1_SMSG_SUCCESS) {
2880 bombout(("Strange packet received, type %d", ssh->pktin.type));
2885 logevent("Authentication successful");
2890 void sshfwd_close(struct ssh_channel *c)
2894 if (c && !c->closes) {
2896 * If the channel's remoteid is -1, we have sent
2897 * CHANNEL_OPEN for this channel, but it hasn't even been
2898 * acknowledged by the server. So we must set a close flag
2899 * on it now, and then when the server acks the channel
2900 * open, we can close it then.
2902 if (((int)c->remoteid) != -1) {
2903 if (ssh->version == 1) {
2904 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
2907 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
2908 ssh2_pkt_adduint32(ssh, c->remoteid);
2912 c->closes = 1; /* sent MSG_CLOSE */
2913 if (c->type == CHAN_X11) {
2915 logevent("Forwarded X11 connection terminated");
2916 } else if (c->type == CHAN_SOCKDATA ||
2917 c->type == CHAN_SOCKDATA_DORMANT) {
2919 logevent("Forwarded port closed");
2924 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
2928 if (ssh->version == 1) {
2929 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2930 PKT_INT, c->remoteid,
2931 PKT_INT, len, PKT_DATA, buf, len, PKT_END);
2933 * In SSH1 we can return 0 here - implying that forwarded
2934 * connections are never individually throttled - because
2935 * the only circumstance that can cause throttling will be
2936 * the whole SSH connection backing up, in which case
2937 * _everything_ will be throttled as a whole.
2941 ssh2_add_channel_data(c, buf, len);
2942 return ssh2_try_send(c);
2946 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
2950 if (ssh->version == 1) {
2951 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
2952 c->v.v1.throttling = 0;
2953 ssh1_throttle(ssh, -1);
2956 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
2960 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
2962 crBegin(ssh->ssh1_protocol_crstate);
2966 while (!do_ssh1_login(ssh, in, inlen, ispkt)) {
2969 if (ssh->state == SSH_STATE_CLOSED)
2972 if (cfg.agentfwd && agent_exists()) {
2973 logevent("Requesting agent forwarding");
2974 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
2978 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
2979 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
2980 bombout(("Protocol confusion"));
2982 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
2983 logevent("Agent forwarding refused");
2985 logevent("Agent forwarding enabled");
2986 ssh->agentfwd_enabled = TRUE;
2990 if (cfg.x11_forward) {
2991 char proto[20], data[64];
2992 logevent("Requesting X11 forwarding");
2993 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
2994 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
2995 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
2996 PKT_STR, proto, PKT_STR, data,
2997 PKT_INT, 0, PKT_END);
2999 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
3000 PKT_STR, proto, PKT_STR, data, PKT_END);
3005 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3006 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3007 bombout(("Protocol confusion"));
3009 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3010 logevent("X11 forwarding refused");
3012 logevent("X11 forwarding enabled");
3013 ssh->X11_fwd_enabled = TRUE;
3020 int sport,dport,sserv,dserv;
3021 char sports[256], dports[256], host[256];
3025 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3026 /* Add port forwardings. */
3027 ssh->portfwd_strptr = cfg.portfwd;
3028 while (*ssh->portfwd_strptr) {
3029 type = *ssh->portfwd_strptr++;
3031 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
3032 sports[n++] = *ssh->portfwd_strptr++;
3034 if (*ssh->portfwd_strptr == '\t')
3035 ssh->portfwd_strptr++;
3037 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
3038 host[n++] = *ssh->portfwd_strptr++;
3040 if (*ssh->portfwd_strptr == ':')
3041 ssh->portfwd_strptr++;
3043 while (*ssh->portfwd_strptr)
3044 dports[n++] = *ssh->portfwd_strptr++;
3046 ssh->portfwd_strptr++;
3047 dport = atoi(dports);
3051 se = getservbyname(dports, NULL);
3053 dport = ntohs(se->s_port);
3056 "Service lookup failed for destination port \"%s\"",
3061 sport = atoi(sports);
3065 se = getservbyname(sports, NULL);
3067 sport = ntohs(se->s_port);
3070 "Service lookup failed for source port \"%s\"",
3075 if (sport && dport) {
3077 pfd_addforward(host, dport, sport);
3078 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
3079 " %s:%.*s%.*s%d%.*s",
3080 sserv ? strlen(sports) : 0, sports,
3081 sserv, "(", sport, sserv, ")",
3083 dserv ? strlen(dports) : 0, dports,
3084 dserv, "(", dport, dserv, ")");
3087 struct ssh_rportfwd *pf;
3088 pf = smalloc(sizeof(*pf));
3089 strcpy(pf->dhost, host);
3091 if (add234(ssh->rportfwds, pf) != pf) {
3093 "Duplicate remote port forwarding to %s:%d",
3098 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
3099 " forward to %s:%.*s%.*s%d%.*s",
3100 sserv ? strlen(sports) : 0, sports,
3101 sserv, "(", sport, sserv, ")",
3103 dserv ? strlen(dports) : 0, dports,
3104 dserv, "(", dport, dserv, ")");
3106 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3114 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3115 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3116 bombout(("Protocol confusion"));
3118 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3119 c_write_str(ssh, "Server refused port"
3122 logevent("Remote port forwarding enabled");
3130 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
3131 PKT_STR, cfg.termtype,
3132 PKT_INT, ssh->term_height,
3133 PKT_INT, ssh->term_width,
3134 PKT_INT, 0, PKT_INT, 0, PKT_CHAR, 0, PKT_END);
3135 ssh->state = SSH_STATE_INTERMED;
3139 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3140 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3141 bombout(("Protocol confusion"));
3143 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3144 c_write_str(ssh, "Server refused to allocate pty\r\n");
3145 ssh->editing = ssh->echoing = 1;
3147 logevent("Allocated pty");
3149 ssh->editing = ssh->echoing = 1;
3152 if (cfg.compression) {
3153 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
3157 if (ssh->pktin.type != SSH1_SMSG_SUCCESS
3158 && ssh->pktin.type != SSH1_SMSG_FAILURE) {
3159 bombout(("Protocol confusion"));
3161 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3162 c_write_str(ssh, "Server refused to compress\r\n");
3164 logevent("Started compression");
3165 ssh->v1_compressing = TRUE;
3166 zlib_compress_init();
3167 zlib_decompress_init();
3171 * Start the shell or command.
3173 * Special case: if the first-choice command is an SSH2
3174 * subsystem (hence not usable here) and the second choice
3175 * exists, we fall straight back to that.
3178 char *cmd = cfg.remote_cmd_ptr;
3180 if (cfg.ssh_subsys && cfg.remote_cmd_ptr2) {
3181 cmd = cfg.remote_cmd_ptr2;
3182 ssh->fallback_cmd = TRUE;
3185 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
3187 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
3188 logevent("Started session");
3191 ssh->state = SSH_STATE_SESSION;
3192 if (ssh->size_needed)
3193 ssh_size(ssh, ssh->term_width, ssh->term_height);
3194 if (ssh->eof_needed)
3195 ssh_special(ssh, TS_EOF);
3197 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
3199 ssh->channels = newtree234(ssh_channelcmp);
3203 if (ssh->pktin.type == SSH1_SMSG_STDOUT_DATA ||
3204 ssh->pktin.type == SSH1_SMSG_STDERR_DATA) {
3205 long len = GET_32BIT(ssh->pktin.body);
3207 from_backend(ssh->frontend,
3208 ssh->pktin.type == SSH1_SMSG_STDERR_DATA,
3209 ssh->pktin.body + 4, len);
3210 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
3211 ssh->v1_stdout_throttling = 1;
3212 ssh1_throttle(ssh, +1);
3214 } else if (ssh->pktin.type == SSH1_MSG_DISCONNECT) {
3215 ssh->state = SSH_STATE_CLOSED;
3216 logevent("Received disconnect request");
3218 } else if (ssh->pktin.type == SSH1_SMSG_X11_OPEN) {
3219 /* Remote side is trying to open a channel to talk to our
3220 * X-Server. Give them back a local channel number. */
3221 struct ssh_channel *c;
3223 logevent("Received X11 connect request");
3224 /* Refuse if X11 forwarding is disabled. */
3225 if (!ssh->X11_fwd_enabled) {
3226 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3227 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3228 logevent("Rejected X11 connect request");
3230 c = smalloc(sizeof(struct ssh_channel));
3233 if (x11_init(&c->u.x11.s, cfg.x11_display, c) != NULL) {
3234 logevent("opening X11 forward connection failed");
3236 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3237 PKT_INT, GET_32BIT(ssh->pktin.body),
3241 ("opening X11 forward connection succeeded");
3242 c->remoteid = GET_32BIT(ssh->pktin.body);
3243 c->localid = alloc_channel_id(ssh);
3245 c->v.v1.throttling = 0;
3246 c->type = CHAN_X11; /* identify channel type */
3247 add234(ssh->channels, c);
3248 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3249 PKT_INT, c->remoteid, PKT_INT,
3250 c->localid, PKT_END);
3251 logevent("Opened X11 forward channel");
3254 } else if (ssh->pktin.type == SSH1_SMSG_AGENT_OPEN) {
3255 /* Remote side is trying to open a channel to talk to our
3256 * agent. Give them back a local channel number. */
3257 struct ssh_channel *c;
3259 /* Refuse if agent forwarding is disabled. */
3260 if (!ssh->agentfwd_enabled) {
3261 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3262 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3264 c = smalloc(sizeof(struct ssh_channel));
3266 c->remoteid = GET_32BIT(ssh->pktin.body);
3267 c->localid = alloc_channel_id(ssh);
3269 c->v.v1.throttling = 0;
3270 c->type = CHAN_AGENT; /* identify channel type */
3271 c->u.a.lensofar = 0;
3272 add234(ssh->channels, c);
3273 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3274 PKT_INT, c->remoteid, PKT_INT, c->localid,
3277 } else if (ssh->pktin.type == SSH1_MSG_PORT_OPEN) {
3278 /* Remote side is trying to open a channel to talk to a
3279 * forwarded port. Give them back a local channel number. */
3280 struct ssh_channel *c;
3281 struct ssh_rportfwd pf;
3283 char host[256], buf[1024];
3285 c = smalloc(sizeof(struct ssh_channel));
3288 hostsize = GET_32BIT(ssh->pktin.body+4);
3289 for(h = host, p = ssh->pktin.body+8; hostsize != 0; hostsize--) {
3290 if (h+1 < host+sizeof(host))
3295 port = GET_32BIT(p);
3297 strcpy(pf.dhost, host);
3300 if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
3301 sprintf(buf, "Rejected remote port open request for %s:%d",
3304 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3305 PKT_INT, GET_32BIT(ssh->pktin.body), PKT_END);
3307 sprintf(buf, "Received remote port open request for %s:%d",
3310 e = pfd_newconnect(&c->u.pfd.s, host, port, c);
3313 sprintf(buf, "Port open failed: %s", e);
3316 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
3317 PKT_INT, GET_32BIT(ssh->pktin.body),
3320 c->remoteid = GET_32BIT(ssh->pktin.body);
3321 c->localid = alloc_channel_id(ssh);
3323 c->v.v1.throttling = 0;
3324 c->type = CHAN_SOCKDATA; /* identify channel type */
3325 add234(ssh->channels, c);
3326 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
3327 PKT_INT, c->remoteid, PKT_INT,
3328 c->localid, PKT_END);
3329 logevent("Forwarded port opened successfully");
3333 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_CONFIRMATION) {
3334 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3335 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3336 struct ssh_channel *c;
3338 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3339 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3340 c->remoteid = localid;
3341 c->type = CHAN_SOCKDATA;
3342 c->v.v1.throttling = 0;
3343 pfd_confirm(c->u.pfd.s);
3346 if (c && c->closes) {
3348 * We have a pending close on this channel,
3349 * which we decided on before the server acked
3350 * the channel open. So now we know the
3351 * remoteid, we can close it again.
3353 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
3354 PKT_INT, c->remoteid, PKT_END);
3357 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_OPEN_FAILURE) {
3358 unsigned int remoteid = GET_32BIT(ssh->pktin.body);
3359 unsigned int localid = GET_32BIT(ssh->pktin.body+4);
3360 struct ssh_channel *c;
3362 c = find234(ssh->channels, &remoteid, ssh_channelfind);
3363 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
3364 logevent("Forwarded connection refused by server");
3365 pfd_close(c->u.pfd.s);
3366 del234(ssh->channels, c);
3370 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
3371 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
3372 /* Remote side closes a channel. */
3373 unsigned i = GET_32BIT(ssh->pktin.body);
3374 struct ssh_channel *c;
3375 c = find234(ssh->channels, &i, ssh_channelfind);
3376 if (c && ((int)c->remoteid) != -1) {
3379 (ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
3381 if ((c->closes == 0) && (c->type == CHAN_X11)) {
3382 logevent("Forwarded X11 connection terminated");
3383 assert(c->u.x11.s != NULL);
3384 x11_close(c->u.x11.s);
3387 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
3388 logevent("Forwarded port closed");
3389 assert(c->u.pfd.s != NULL);
3390 pfd_close(c->u.pfd.s);
3394 c->closes |= (closetype << 2); /* seen this message */
3395 if (!(c->closes & closetype)) {
3396 send_packet(ssh, ssh->pktin.type, PKT_INT, c->remoteid,
3398 c->closes |= closetype; /* sent it too */
3401 if (c->closes == 15) {
3402 del234(ssh->channels, c);
3406 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
3407 ssh->pktin.type == SSH1_MSG_CHANNEL_CLOSE ? "" :
3408 "_CONFIRMATION", c ? "half-open" : "nonexistent",
3411 } else if (ssh->pktin.type == SSH1_MSG_CHANNEL_DATA) {
3412 /* Data sent down one of our channels. */
3413 int i = GET_32BIT(ssh->pktin.body);
3414 int len = GET_32BIT(ssh->pktin.body + 4);
3415 unsigned char *p = ssh->pktin.body + 8;
3416 struct ssh_channel *c;
3417 c = find234(ssh->channels, &i, ssh_channelfind);
3422 bufsize = x11_send(c->u.x11.s, p, len);
3425 bufsize = pfd_send(c->u.pfd.s, p, len);
3428 /* Data for an agent message. Buffer it. */
3430 if (c->u.a.lensofar < 4) {
3431 int l = min(4 - c->u.a.lensofar, len);
3432 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
3436 c->u.a.lensofar += l;
3438 if (c->u.a.lensofar == 4) {
3440 4 + GET_32BIT(c->u.a.msglen);
3441 c->u.a.message = smalloc(c->u.a.totallen);
3442 memcpy(c->u.a.message, c->u.a.msglen, 4);
3444 if (c->u.a.lensofar >= 4 && len > 0) {
3446 min(c->u.a.totallen - c->u.a.lensofar,
3448 memcpy(c->u.a.message + c->u.a.lensofar, p,
3452 c->u.a.lensofar += l;
3454 if (c->u.a.lensofar == c->u.a.totallen) {
3455 void *reply, *sentreply;
3457 agent_query(c->u.a.message,
3458 c->u.a.totallen, &reply,
3463 /* Fake SSH_AGENT_FAILURE. */
3464 sentreply = "\0\0\0\1\5";
3467 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3468 PKT_INT, c->remoteid,
3470 PKT_DATA, sentreply, replylen,
3474 sfree(c->u.a.message);
3475 c->u.a.lensofar = 0;
3478 bufsize = 0; /* agent channels never back up */
3481 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
3482 c->v.v1.throttling = 1;
3483 ssh1_throttle(ssh, +1);
3486 } else if (ssh->pktin.type == SSH1_SMSG_SUCCESS) {
3487 /* may be from EXEC_SHELL on some servers */
3488 } else if (ssh->pktin.type == SSH1_SMSG_FAILURE) {
3489 /* may be from EXEC_SHELL on some servers
3490 * if no pty is available or in other odd cases. Ignore */
3491 } else if (ssh->pktin.type == SSH1_SMSG_EXIT_STATUS) {
3493 ssh->exitcode = GET_32BIT(ssh->pktin.body);
3494 sprintf(buf, "Server sent command exit status %d",
3497 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
3499 * In case `helpful' firewalls or proxies tack
3500 * extra human-readable text on the end of the
3501 * session which we might mistake for another
3502 * encrypted packet, we close the session once
3503 * we've sent EXIT_CONFIRMATION.
3505 ssh->state = SSH_STATE_CLOSED;
3508 bombout(("Strange packet received: type %d", ssh->pktin.type));
3513 int len = min(inlen, 512);
3514 send_packet(ssh, SSH1_CMSG_STDIN_DATA,
3515 PKT_INT, len, PKT_DATA, in, len, PKT_END);
3526 * Utility routine for decoding comma-separated strings in KEXINIT.
3528 static int in_commasep_string(char *needle, char *haystack, int haylen)
3530 int needlen = strlen(needle);
3533 * Is it at the start of the string?
3535 if (haylen >= needlen && /* haystack is long enough */
3536 !memcmp(needle, haystack, needlen) && /* initial match */
3537 (haylen == needlen || haystack[needlen] == ',')
3538 /* either , or EOS follows */
3542 * If not, search for the next comma and resume after that.
3543 * If no comma found, terminate.
3545 while (haylen > 0 && *haystack != ',')
3546 haylen--, haystack++;
3549 haylen--, haystack++; /* skip over comma itself */
3554 * SSH2 key creation method.
3556 static void ssh2_mkkey(Ssh ssh, Bignum K, char *H, char *sessid, char chr,
3560 /* First 20 bytes. */
3562 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3564 SHA_Bytes(&s, H, 20);
3565 SHA_Bytes(&s, &chr, 1);
3566 SHA_Bytes(&s, sessid, 20);
3567 SHA_Final(&s, keyspace);
3568 /* Next 20 bytes. */
3570 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
3572 SHA_Bytes(&s, H, 20);
3573 SHA_Bytes(&s, keyspace, 20);
3574 SHA_Final(&s, keyspace + 20);
3578 * Handle the SSH2 transport layer.
3580 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen, int ispkt)
3582 struct do_ssh2_transport_state {
3583 int nbits, pbits, warn;
3584 Bignum p, g, e, f, K;
3585 int kex_init_value, kex_reply_value;
3586 const struct ssh_mac **maclist;
3588 const struct ssh2_cipher *cscipher_tobe;
3589 const struct ssh2_cipher *sccipher_tobe;
3590 const struct ssh_mac *csmac_tobe;
3591 const struct ssh_mac *scmac_tobe;
3592 const struct ssh_compress *cscomp_tobe;
3593 const struct ssh_compress *sccomp_tobe;
3594 char *hostkeydata, *sigdata, *keystr, *fingerprint;
3595 int hostkeylen, siglen;
3596 void *hkey; /* actual host key */
3597 unsigned char exchange_hash[20];
3598 int n_preferred_ciphers;
3599 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
3600 const struct ssh_compress *preferred_comp;
3603 crState(do_ssh2_transport_state);
3605 crBegin(ssh->do_ssh2_transport_crstate);
3607 s->cscipher_tobe = s->sccipher_tobe = NULL;
3608 s->csmac_tobe = s->scmac_tobe = NULL;
3609 s->cscomp_tobe = s->sccomp_tobe = NULL;
3617 * Set up the preferred ciphers. (NULL => warn below here)
3619 s->n_preferred_ciphers = 0;
3620 for (i = 0; i < CIPHER_MAX; i++) {
3621 switch (cfg.ssh_cipherlist[i]) {
3622 case CIPHER_BLOWFISH:
3623 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
3626 if (cfg.ssh2_des_cbc) {
3627 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
3631 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
3634 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
3637 /* Flag for later. Don't bother if it's the last in
3639 if (i < CIPHER_MAX - 1) {
3640 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
3648 * Set up preferred compression.
3650 if (cfg.compression)
3651 s->preferred_comp = &ssh_zlib;
3653 s->preferred_comp = &ssh_comp_none;
3656 * Be prepared to work around the buggy MAC problem.
3658 if (ssh->remote_bugs & BUG_SSH2_HMAC)
3659 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
3661 s->maclist = macs, s->nmacs = lenof(macs);
3665 int i, j, cipherstr_started;
3668 * Construct and send our key exchange packet.
3670 ssh2_pkt_init(ssh, SSH2_MSG_KEXINIT);
3671 for (i = 0; i < 16; i++)
3672 ssh2_pkt_addbyte(ssh, (unsigned char) random_byte());
3673 /* List key exchange algorithms. */
3674 ssh2_pkt_addstring_start(ssh);
3675 for (i = 0; i < lenof(kex_algs); i++) {
3676 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3677 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3679 ssh2_pkt_addstring_str(ssh, kex_algs[i]->name);
3680 if (i < lenof(kex_algs) - 1)
3681 ssh2_pkt_addstring_str(ssh, ",");
3683 /* List server host key algorithms. */
3684 ssh2_pkt_addstring_start(ssh);
3685 for (i = 0; i < lenof(hostkey_algs); i++) {
3686 ssh2_pkt_addstring_str(ssh, hostkey_algs[i]->name);
3687 if (i < lenof(hostkey_algs) - 1)
3688 ssh2_pkt_addstring_str(ssh, ",");
3690 /* List client->server encryption algorithms. */
3691 ssh2_pkt_addstring_start(ssh);
3692 cipherstr_started = 0;
3693 for (i = 0; i < s->n_preferred_ciphers; i++) {
3694 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3695 if (!c) continue; /* warning flag */
3696 for (j = 0; j < c->nciphers; j++) {
3697 if (cipherstr_started)
3698 ssh2_pkt_addstring_str(ssh, ",");
3699 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3700 cipherstr_started = 1;
3703 /* List server->client encryption algorithms. */
3704 ssh2_pkt_addstring_start(ssh);
3705 cipherstr_started = 0;
3706 for (i = 0; i < s->n_preferred_ciphers; i++) {
3707 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3708 if (!c) continue; /* warning flag */
3709 for (j = 0; j < c->nciphers; j++) {
3710 if (cipherstr_started)
3711 ssh2_pkt_addstring_str(ssh, ",");
3712 ssh2_pkt_addstring_str(ssh, c->list[j]->name);
3713 cipherstr_started = 1;
3716 /* List client->server MAC algorithms. */
3717 ssh2_pkt_addstring_start(ssh);
3718 for (i = 0; i < s->nmacs; i++) {
3719 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3720 if (i < s->nmacs - 1)
3721 ssh2_pkt_addstring_str(ssh, ",");
3723 /* List server->client MAC algorithms. */
3724 ssh2_pkt_addstring_start(ssh);
3725 for (i = 0; i < s->nmacs; i++) {
3726 ssh2_pkt_addstring_str(ssh, s->maclist[i]->name);
3727 if (i < s->nmacs - 1)
3728 ssh2_pkt_addstring_str(ssh, ",");
3730 /* List client->server compression algorithms. */
3731 ssh2_pkt_addstring_start(ssh);
3732 for (i = 0; i < lenof(compressions) + 1; i++) {
3733 const struct ssh_compress *c =
3734 i == 0 ? s->preferred_comp : compressions[i - 1];
3735 ssh2_pkt_addstring_str(ssh, c->name);
3736 if (i < lenof(compressions))
3737 ssh2_pkt_addstring_str(ssh, ",");
3739 /* List server->client compression algorithms. */
3740 ssh2_pkt_addstring_start(ssh);
3741 for (i = 0; i < lenof(compressions) + 1; i++) {
3742 const struct ssh_compress *c =
3743 i == 0 ? s->preferred_comp : compressions[i - 1];
3744 ssh2_pkt_addstring_str(ssh, c->name);
3745 if (i < lenof(compressions))
3746 ssh2_pkt_addstring_str(ssh, ",");
3748 /* List client->server languages. Empty list. */
3749 ssh2_pkt_addstring_start(ssh);
3750 /* List server->client languages. Empty list. */
3751 ssh2_pkt_addstring_start(ssh);
3752 /* First KEX packet does _not_ follow, because we're not that brave. */
3753 ssh2_pkt_addbool(ssh, FALSE);
3755 ssh2_pkt_adduint32(ssh, 0);
3758 ssh->exhash = ssh->exhashbase;
3759 sha_string(&ssh->exhash, ssh->pktout.data + 5, ssh->pktout.length - 5);
3765 sha_string(&ssh->exhash, ssh->pktin.data + 5, ssh->pktin.length - 5);
3768 * Now examine the other side's KEXINIT to see what we're up
3775 if (ssh->pktin.type != SSH2_MSG_KEXINIT) {
3776 bombout(("expected key exchange packet from server"));
3780 ssh->hostkey = NULL;
3781 s->cscipher_tobe = NULL;
3782 s->sccipher_tobe = NULL;
3783 s->csmac_tobe = NULL;
3784 s->scmac_tobe = NULL;
3785 s->cscomp_tobe = NULL;
3786 s->sccomp_tobe = NULL;
3787 ssh->pktin.savedpos += 16; /* skip garbage cookie */
3788 ssh2_pkt_getstring(ssh, &str, &len); /* key exchange algorithms */
3789 for (i = 0; i < lenof(kex_algs); i++) {
3790 if (kex_algs[i] == &ssh_diffiehellman_gex &&
3791 (ssh->remote_bugs & BUG_SSH2_DH_GEX))
3793 if (in_commasep_string(kex_algs[i]->name, str, len)) {
3794 ssh->kex = kex_algs[i];
3798 ssh2_pkt_getstring(ssh, &str, &len); /* host key algorithms */
3799 for (i = 0; i < lenof(hostkey_algs); i++) {
3800 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
3801 ssh->hostkey = hostkey_algs[i];
3805 ssh2_pkt_getstring(ssh, &str, &len); /* client->server cipher */
3807 for (i = 0; i < s->n_preferred_ciphers; i++) {
3808 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3812 for (j = 0; j < c->nciphers; j++) {
3813 if (in_commasep_string(c->list[j]->name, str, len)) {
3814 s->cscipher_tobe = c->list[j];
3819 if (s->cscipher_tobe) {
3821 askcipher(s->cscipher_tobe->name, 1);
3825 if (!s->cscipher_tobe) {
3826 bombout(("Couldn't agree a client-to-server cipher (available: %s)", str));
3830 ssh2_pkt_getstring(ssh, &str, &len); /* server->client cipher */
3832 for (i = 0; i < s->n_preferred_ciphers; i++) {
3833 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
3837 for (j = 0; j < c->nciphers; j++) {
3838 if (in_commasep_string(c->list[j]->name, str, len)) {
3839 s->sccipher_tobe = c->list[j];
3844 if (s->sccipher_tobe) {
3846 askcipher(s->sccipher_tobe->name, 2);
3850 if (!s->sccipher_tobe) {
3851 bombout(("Couldn't agree a server-to-client cipher (available: %s)", str));
3855 ssh2_pkt_getstring(ssh, &str, &len); /* client->server mac */
3856 for (i = 0; i < s->nmacs; i++) {
3857 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3858 s->csmac_tobe = s->maclist[i];
3862 ssh2_pkt_getstring(ssh, &str, &len); /* server->client mac */
3863 for (i = 0; i < s->nmacs; i++) {
3864 if (in_commasep_string(s->maclist[i]->name, str, len)) {
3865 s->scmac_tobe = s->maclist[i];
3869 ssh2_pkt_getstring(ssh, &str, &len); /* client->server compression */
3870 for (i = 0; i < lenof(compressions) + 1; i++) {
3871 const struct ssh_compress *c =
3872 i == 0 ? s->preferred_comp : compressions[i - 1];
3873 if (in_commasep_string(c->name, str, len)) {
3878 ssh2_pkt_getstring(ssh, &str, &len); /* server->client compression */
3879 for (i = 0; i < lenof(compressions) + 1; i++) {
3880 const struct ssh_compress *c =
3881 i == 0 ? s->preferred_comp : compressions[i - 1];
3882 if (in_commasep_string(c->name, str, len)) {
3890 * Work out the number of bits of key we will need from the key
3891 * exchange. We start with the maximum key length of either
3897 csbits = s->cscipher_tobe->keylen;
3898 scbits = s->sccipher_tobe->keylen;
3899 s->nbits = (csbits > scbits ? csbits : scbits);
3901 /* The keys only have 160-bit entropy, since they're based on
3902 * a SHA-1 hash. So cap the key size at 160 bits. */
3907 * If we're doing Diffie-Hellman group exchange, start by
3908 * requesting a group.
3910 if (ssh->kex == &ssh_diffiehellman_gex) {
3911 logevent("Doing Diffie-Hellman group exchange");
3912 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
3914 * Work out how big a DH group we will need to allow that
3917 s->pbits = 512 << ((s->nbits - 1) / 64);
3918 ssh2_pkt_init(ssh, SSH2_MSG_KEX_DH_GEX_REQUEST);
3919 ssh2_pkt_adduint32(ssh, s->pbits);
3923 if (ssh->pktin.type != SSH2_MSG_KEX_DH_GEX_GROUP) {
3924 bombout(("expected key exchange group packet from server"));
3927 s->p = ssh2_pkt_getmp(ssh);
3928 s->g = ssh2_pkt_getmp(ssh);
3929 dh_setup_group(s->p, s->g);
3930 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
3931 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
3933 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP1;
3935 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
3936 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
3939 logevent("Doing Diffie-Hellman key exchange");
3941 * Now generate and send e for Diffie-Hellman.
3943 s->e = dh_create_e(s->nbits * 2);
3944 ssh2_pkt_init(ssh, s->kex_init_value);
3945 ssh2_pkt_addmp(ssh, s->e);
3949 if (ssh->pktin.type != s->kex_reply_value) {
3950 bombout(("expected key exchange reply packet from server"));
3953 ssh2_pkt_getstring(ssh, &s->hostkeydata, &s->hostkeylen);
3954 s->f = ssh2_pkt_getmp(ssh);
3955 ssh2_pkt_getstring(ssh, &s->sigdata, &s->siglen);
3957 s->K = dh_find_K(s->f);
3959 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
3960 if (ssh->kex == &ssh_diffiehellman_gex) {
3961 sha_uint32(&ssh->exhash, s->pbits);
3962 sha_mpint(&ssh->exhash, s->p);
3963 sha_mpint(&ssh->exhash, s->g);
3965 sha_mpint(&ssh->exhash, s->e);
3966 sha_mpint(&ssh->exhash, s->f);
3967 sha_mpint(&ssh->exhash, s->K);
3968 SHA_Final(&ssh->exhash, s->exchange_hash);
3973 debug(("Exchange hash is:\n"));
3974 dmemdump(s->exchange_hash, 20);
3977 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
3979 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
3980 s->exchange_hash, 20)) {
3981 bombout(("Server's host key did not match the signature supplied"));
3986 * Authenticate remote host: verify host key. (We've already
3987 * checked the signature of the exchange hash.)
3989 s->keystr = ssh->hostkey->fmtkey(s->hkey);
3990 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
3991 verify_ssh_host_key(ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
3992 s->keystr, s->fingerprint);
3993 if (s->first_kex) { /* don't bother logging this in rekeys */
3994 logevent("Host key fingerprint is:");
3995 logevent(s->fingerprint);
3997 sfree(s->fingerprint);
3999 ssh->hostkey->freekey(s->hkey);
4002 * Send SSH2_MSG_NEWKEYS.
4004 ssh2_pkt_init(ssh, SSH2_MSG_NEWKEYS);
4008 * Expect SSH2_MSG_NEWKEYS from server.
4011 if (ssh->pktin.type != SSH2_MSG_NEWKEYS) {
4012 bombout(("expected new-keys packet from server"));
4017 * Create and initialise session keys.
4019 ssh->cscipher = s->cscipher_tobe;
4020 ssh->sccipher = s->sccipher_tobe;
4021 ssh->csmac = s->csmac_tobe;
4022 ssh->scmac = s->scmac_tobe;
4023 ssh->cscomp = s->cscomp_tobe;
4024 ssh->sccomp = s->sccomp_tobe;
4025 ssh->cscomp->compress_init();
4026 ssh->sccomp->decompress_init();
4028 * Set IVs after keys. Here we use the exchange hash from the
4029 * _first_ key exchange.
4032 unsigned char keyspace[40];
4034 memcpy(ssh->v2_session_id, s->exchange_hash,
4035 sizeof(s->exchange_hash));
4036 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
4037 ssh->cscipher->setcskey(keyspace);
4038 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
4039 ssh->sccipher->setsckey(keyspace);
4040 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
4041 ssh->cscipher->setcsiv(keyspace);
4042 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
4043 ssh->sccipher->setsciv(keyspace);
4044 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
4045 ssh->csmac->setcskey(keyspace);
4046 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
4047 ssh->scmac->setsckey(keyspace);
4051 * If this is the first key exchange phase, we must pass the
4052 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
4053 * wants to see it but because it will need time to initialise
4054 * itself before it sees an actual packet. In subsequent key
4055 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
4056 * it would only confuse the layer above.
4058 if (!s->first_kex) {
4064 * Now we're encrypting. Begin returning 1 to the protocol main
4065 * function so that other things can run on top of the
4066 * transport. If we ever see a KEXINIT, we must go back to the
4069 while (!(ispkt && ssh->pktin.type == SSH2_MSG_KEXINIT)) {
4072 logevent("Server initiated key re-exchange");
4073 goto begin_key_exchange;
4079 * Add data to an SSH2 channel output buffer.
4081 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
4084 bufchain_add(&c->v.v2.outbuffer, buf, len);
4088 * Attempt to send data on an SSH2 channel.
4090 static int ssh2_try_send(struct ssh_channel *c)
4094 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
4097 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
4098 if ((unsigned)len > c->v.v2.remwindow)
4099 len = c->v.v2.remwindow;
4100 if ((unsigned)len > c->v.v2.remmaxpkt)
4101 len = c->v.v2.remmaxpkt;
4102 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_DATA);
4103 ssh2_pkt_adduint32(ssh, c->remoteid);
4104 ssh2_pkt_addstring_start(ssh);
4105 ssh2_pkt_addstring_data(ssh, data, len);
4107 bufchain_consume(&c->v.v2.outbuffer, len);
4108 c->v.v2.remwindow -= len;
4112 * After having sent as much data as we can, return the amount
4115 return bufchain_size(&c->v.v2.outbuffer);
4119 * Potentially enlarge the window on an SSH2 channel.
4121 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
4126 * Never send WINDOW_ADJUST for a channel that the remote side
4127 * already thinks it's closed; there's no point, since it won't
4128 * be sending any more data anyway.
4133 if (newwin > c->v.v2.locwindow) {
4134 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4135 ssh2_pkt_adduint32(ssh, c->remoteid);
4136 ssh2_pkt_adduint32(ssh, newwin - c->v.v2.locwindow);
4138 c->v.v2.locwindow = newwin;
4143 * Handle the SSH2 userauth and connection layers.
4145 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen, int ispkt)
4147 struct do_ssh2_authconn_state {
4149 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
4151 AUTH_KEYBOARD_INTERACTIVE
4155 AUTH_TYPE_PUBLICKEY,
4156 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
4157 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
4159 AUTH_TYPE_KEYBOARD_INTERACTIVE,
4160 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
4162 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
4163 int tried_pubkey_config, tried_agent, tried_keyb_inter;
4164 int kbd_inter_running;
4166 int num_prompts, curr_prompt, echo;
4171 void *publickey_blob;
4172 int publickey_bloblen;
4173 unsigned char request[5], *response, *p;
4177 char *pkblob, *alg, *commentp;
4178 int pklen, alglen, commentlen;
4179 int siglen, retlen, len;
4180 char *q, *agentreq, *ret;
4183 crState(do_ssh2_authconn_state);
4185 crBegin(ssh->do_ssh2_authconn_crstate);
4188 * Request userauth protocol, and await a response to it.
4190 ssh2_pkt_init(ssh, SSH2_MSG_SERVICE_REQUEST);
4191 ssh2_pkt_addstring(ssh, "ssh-userauth");
4193 crWaitUntilV(ispkt);
4194 if (ssh->pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
4195 bombout(("Server refused user authentication protocol"));
4200 * We repeat this whole loop, including the username prompt,
4201 * until we manage a successful authentication. If the user
4202 * types the wrong _password_, they can be sent back to the
4203 * beginning to try another username, if this is configured on.
4204 * (If they specify a username in the config, they are never
4205 * asked, even if they do give a wrong password.)
4207 * I think this best serves the needs of
4209 * - the people who have no configuration, no keys, and just
4210 * want to try repeated (username,password) pairs until they
4211 * type both correctly
4213 * - people who have keys and configuration but occasionally
4214 * need to fall back to passwords
4216 * - people with a key held in Pageant, who might not have
4217 * logged in to a particular machine before; so they want to
4218 * type a username, and then _either_ their key will be
4219 * accepted, _or_ they will type a password. If they mistype
4220 * the username they will want to be able to get back and
4223 s->username[0] = '\0';
4224 s->got_username = FALSE;
4229 if (s->got_username && !cfg.change_username) {
4231 * We got a username last time round this loop, and
4232 * with change_username turned off we don't try to get
4235 } else if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
4236 if (ssh_get_line && !ssh_getline_pw_only) {
4237 if (!ssh_get_line("login as: ",
4238 s->username, sizeof(s->username), FALSE)) {
4240 * get_line failed to get a username.
4243 logevent("No username provided. Abandoning session.");
4244 ssh->state = SSH_STATE_CLOSED;
4248 int ret; /* need not be saved across crReturn */
4249 c_write_str(ssh, "login as: ");
4251 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
4253 crWaitUntilV(!ispkt);
4254 ret = process_userpass_input(ssh, in, inlen);
4259 c_write_str(ssh, "\r\n");
4260 s->username[strcspn(s->username, "\n\r")] = '\0';
4263 strncpy(s->username, cfg.username, sizeof(s->username));
4264 s->username[sizeof(s->username)-1] = '\0';
4265 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
4266 sprintf(stuff, "Using username \"%s\".\r\n", s->username);
4267 c_write_str(ssh, stuff);
4270 s->got_username = TRUE;
4273 * Send an authentication request using method "none": (a)
4274 * just in case it succeeds, and (b) so that we know what
4275 * authentication methods we can usefully try next.
4277 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4279 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4280 ssh2_pkt_addstring(ssh, s->username);
4281 ssh2_pkt_addstring(ssh, "ssh-connection");/* service requested */
4282 ssh2_pkt_addstring(ssh, "none"); /* method */
4284 s->type = AUTH_TYPE_NONE;
4286 s->we_are_in = FALSE;
4288 s->tried_pubkey_config = FALSE;
4289 s->tried_agent = FALSE;
4290 s->tried_keyb_inter = FALSE;
4291 s->kbd_inter_running = FALSE;
4292 /* Load the pub half of cfg.keyfile so we notice if it's in Pageant */
4295 logeventf("Reading private key file \"%.150s\"", cfg.keyfile);
4296 keytype = key_type(cfg.keyfile);
4297 if (keytype == SSH_KEYTYPE_SSH2) {
4299 ssh2_userkey_loadpub(cfg.keyfile, NULL,
4300 &s->publickey_bloblen);
4303 logeventf("Unable to use this key file (%s)",
4304 key_type_to_str(keytype));
4305 sprintf(msgbuf, "Unable to use key file \"%.150s\" (%s)\r\n",
4306 cfg.keyfile, key_type_to_str(keytype));
4307 c_write_str(ssh, msgbuf);
4308 s->publickey_blob = NULL;
4311 s->publickey_blob = NULL;
4315 * Wait for the result of the last authentication request.
4318 crWaitUntilV(ispkt);
4319 while (ssh->pktin.type == SSH2_MSG_USERAUTH_BANNER) {
4323 * Don't show the banner if we're operating in
4324 * non-verbose non-interactive mode. (It's probably
4325 * a script, which means nobody will read the
4326 * banner _anyway_, and moreover the printing of
4327 * the banner will screw up processing on the
4328 * output of (say) plink.)
4330 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
4331 ssh2_pkt_getstring(ssh, &banner, &size);
4333 c_write_untrusted(ssh, banner, size);
4335 crWaitUntilV(ispkt);
4337 if (ssh->pktin.type == SSH2_MSG_USERAUTH_SUCCESS) {
4338 logevent("Access granted");
4339 s->we_are_in = TRUE;
4343 if (s->kbd_inter_running &&
4344 ssh->pktin.type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
4346 * This is either a further set-of-prompts packet
4347 * in keyboard-interactive authentication, or it's
4348 * the same one and we came back here with `gotit'
4349 * set. In the former case, we must reset the
4350 * curr_prompt variable.
4354 } else if (ssh->pktin.type != SSH2_MSG_USERAUTH_FAILURE) {
4355 bombout(("Strange packet received during authentication: type %d",
4363 * OK, we're now sitting on a USERAUTH_FAILURE message, so
4364 * we can look at the string in it and know what we can
4365 * helpfully try next.
4367 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE) {
4370 ssh2_pkt_getstring(ssh, &methods, &methlen);
4371 s->kbd_inter_running = FALSE;
4372 if (!ssh2_pkt_getbool(ssh)) {
4374 * We have received an unequivocal Access
4375 * Denied. This can translate to a variety of
4378 * - if we'd just tried "none" authentication,
4379 * it's not worth printing anything at all
4381 * - if we'd just tried a public key _offer_,
4382 * the message should be "Server refused our
4383 * key" (or no message at all if the key
4384 * came from Pageant)
4386 * - if we'd just tried anything else, the
4387 * message really should be "Access denied".
4389 * Additionally, if we'd just tried password
4390 * authentication, we should break out of this
4391 * whole loop so as to go back to the username
4394 if (s->type == AUTH_TYPE_NONE) {
4396 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
4397 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
4398 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
4399 c_write_str(ssh, "Server refused our key\r\n");
4400 logevent("Server refused public key");
4401 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
4402 /* server declined keyboard-interactive; ignore */
4404 c_write_str(ssh, "Access denied\r\n");
4405 logevent("Access denied");
4406 if (s->type == AUTH_TYPE_PASSWORD) {
4407 s->we_are_in = FALSE;
4412 c_write_str(ssh, "Further authentication required\r\n");
4413 logevent("Further authentication required");
4417 in_commasep_string("publickey", methods, methlen);
4419 in_commasep_string("password", methods, methlen);
4420 s->can_keyb_inter = cfg.try_ki_auth &&
4421 in_commasep_string("keyboard-interactive", methods, methlen);
4425 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4428 * Most password/passphrase prompts will be
4429 * non-echoing, so we set this to 0 by default.
4430 * Exception is that some keyboard-interactive prompts
4431 * can be echoing, in which case we'll set this to 1.
4435 if (!s->method && s->can_pubkey &&
4436 agent_exists() && !s->tried_agent) {
4438 * Attempt public-key authentication using Pageant.
4443 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4444 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4446 s->tried_agent = TRUE;
4448 logevent("Pageant is running. Requesting keys.");
4450 /* Request the keys held by the agent. */
4451 PUT_32BIT(s->request, 1);
4452 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
4453 agent_query(s->request, 5, &r, &s->responselen);
4454 s->response = (unsigned char *) r;
4455 if (s->response && s->responselen >= 5 &&
4456 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
4457 s->p = s->response + 5;
4458 s->nkeys = GET_32BIT(s->p);
4462 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
4465 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
4470 sprintf(buf, "Trying Pageant key #%d", s->keyi);
4473 s->pklen = GET_32BIT(s->p);
4475 if (s->publickey_blob &&
4476 s->pklen == s->publickey_bloblen &&
4477 !memcmp(s->p, s->publickey_blob,
4478 s->publickey_bloblen)) {
4479 logevent("This key matches configured key file");
4480 s->tried_pubkey_config = 1;
4484 s->alglen = GET_32BIT(s->pkblob);
4485 s->alg = s->pkblob + 4;
4486 s->commentlen = GET_32BIT(s->p);
4489 s->p += s->commentlen;
4490 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4491 ssh2_pkt_addstring(ssh, s->username);
4492 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4493 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4494 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4495 ssh2_pkt_addstring_start(ssh);
4496 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4497 ssh2_pkt_addstring_start(ssh);
4498 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4501 crWaitUntilV(ispkt);
4502 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4503 logevent("Key refused");
4507 if (flags & FLAG_VERBOSE) {
4508 c_write_str(ssh, "Authenticating with "
4510 c_write(ssh, s->commentp, s->commentlen);
4511 c_write_str(ssh, "\" from agent\r\n");
4515 * Server is willing to accept the key.
4516 * Construct a SIGN_REQUEST.
4518 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4519 ssh2_pkt_addstring(ssh, s->username);
4520 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4521 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4522 ssh2_pkt_addbool(ssh, TRUE);
4523 ssh2_pkt_addstring_start(ssh);
4524 ssh2_pkt_addstring_data(ssh, s->alg, s->alglen);
4525 ssh2_pkt_addstring_start(ssh);
4526 ssh2_pkt_addstring_data(ssh, s->pkblob, s->pklen);
4528 s->siglen = ssh->pktout.length - 5 + 4 + 20;
4529 s->len = 1; /* message type */
4530 s->len += 4 + s->pklen; /* key blob */
4531 s->len += 4 + s->siglen; /* data to sign */
4532 s->len += 4; /* flags */
4533 s->agentreq = smalloc(4 + s->len);
4534 PUT_32BIT(s->agentreq, s->len);
4535 s->q = s->agentreq + 4;
4536 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
4537 PUT_32BIT(s->q, s->pklen);
4539 memcpy(s->q, s->pkblob, s->pklen);
4541 PUT_32BIT(s->q, s->siglen);
4543 /* Now the data to be signed... */
4544 PUT_32BIT(s->q, 20);
4546 memcpy(s->q, ssh->v2_session_id, 20);
4548 memcpy(s->q, ssh->pktout.data + 5,
4549 ssh->pktout.length - 5);
4550 s->q += ssh->pktout.length - 5;
4551 /* And finally the (zero) flags word. */
4553 agent_query(s->agentreq, s->len + 4, &vret, &s->retlen);
4557 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
4558 logevent("Sending Pageant's response");
4559 ssh2_add_sigblob(ssh, s->pkblob, s->pklen,
4561 GET_32BIT(s->ret + 5));
4567 ("Pageant failed to answer challenge");
4577 if (!s->method && s->can_pubkey && s->publickey_blob
4578 && !s->tried_pubkey_config) {
4579 unsigned char *pub_blob;
4580 char *algorithm, *comment;
4583 s->tried_pubkey_config = TRUE;
4585 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4586 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
4589 * Try the public key supplied in the configuration.
4591 * First, offer the public blob to see if the server is
4592 * willing to accept it.
4594 pub_blob = ssh2_userkey_loadpub(cfg.keyfile, &algorithm,
4597 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4598 ssh2_pkt_addstring(ssh, s->username);
4599 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4600 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4601 ssh2_pkt_addbool(ssh, FALSE); /* no signature included */
4602 ssh2_pkt_addstring(ssh, algorithm);
4603 ssh2_pkt_addstring_start(ssh);
4604 ssh2_pkt_addstring_data(ssh, pub_blob, pub_blob_len);
4606 logevent("Offered public key"); /* FIXME */
4608 crWaitUntilV(ispkt);
4609 if (ssh->pktin.type != SSH2_MSG_USERAUTH_PK_OK) {
4611 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
4612 continue; /* key refused; give up on it */
4615 logevent("Offer of public key accepted");
4617 * Actually attempt a serious authentication using
4620 if (ssh2_userkey_encrypted(cfg.keyfile, &comment)) {
4621 sprintf(s->pwprompt,
4622 "Passphrase for key \"%.100s\": ",
4628 c_write_str(ssh, "Authenticating with public key \"");
4629 c_write_str(ssh, comment);
4630 c_write_str(ssh, "\"\r\n");
4631 s->method = AUTH_PUBLICKEY_FILE;
4635 if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
4636 s->method = AUTH_KEYBOARD_INTERACTIVE;
4637 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4638 s->tried_keyb_inter = TRUE;
4640 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4641 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4643 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4644 ssh2_pkt_addstring(ssh, s->username);
4645 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4646 ssh2_pkt_addstring(ssh, "keyboard-interactive"); /* method */
4647 ssh2_pkt_addstring(ssh, ""); /* lang */
4648 ssh2_pkt_addstring(ssh, "");
4651 crWaitUntilV(ispkt);
4652 if (ssh->pktin.type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
4653 if (ssh->pktin.type == SSH2_MSG_USERAUTH_FAILURE)
4655 logevent("Keyboard-interactive authentication refused");
4656 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
4660 s->kbd_inter_running = TRUE;
4664 if (s->kbd_inter_running) {
4665 s->method = AUTH_KEYBOARD_INTERACTIVE;
4666 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4667 s->tried_keyb_inter = TRUE;
4669 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4670 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
4672 if (s->curr_prompt == 0) {
4674 * We've got a fresh USERAUTH_INFO_REQUEST.
4675 * Display header data, and start going through
4678 char *name, *inst, *lang;
4679 int name_len, inst_len, lang_len;
4681 ssh2_pkt_getstring(ssh, &name, &name_len);
4682 ssh2_pkt_getstring(ssh, &inst, &inst_len);
4683 ssh2_pkt_getstring(ssh, &lang, &lang_len);
4685 c_write_untrusted(ssh, name, name_len);
4686 c_write_str(ssh, "\r\n");
4689 c_write_untrusted(ssh, inst, inst_len);
4690 c_write_str(ssh, "\r\n");
4692 s->num_prompts = ssh2_pkt_getuint32(ssh);
4696 * If there are prompts remaining in the packet,
4697 * display one and get a response.
4699 if (s->curr_prompt < s->num_prompts) {
4703 ssh2_pkt_getstring(ssh, &prompt, &prompt_len);
4704 if (prompt_len > 0) {
4705 strncpy(s->pwprompt, prompt, sizeof(s->pwprompt));
4706 s->pwprompt[prompt_len < sizeof(s->pwprompt) ?
4707 prompt_len : sizeof(s->pwprompt)-1] = '\0';
4710 "<server failed to send prompt>: ");
4712 s->echo = ssh2_pkt_getbool(ssh);
4718 if (!s->method && s->can_passwd) {
4719 s->method = AUTH_PASSWORD;
4720 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
4721 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
4722 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
4729 if (!ssh_get_line(s->pwprompt, s->password,
4730 sizeof(s->password), TRUE)) {
4732 * get_line failed to get a password (for
4733 * example because one was supplied on the
4734 * command line which has already failed to
4737 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4738 ssh2_pkt_adduint32(ssh,SSH2_DISCONNECT_BY_APPLICATION);
4739 ssh2_pkt_addstring(ssh, "No more passwords available"
4741 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4743 logevent("Unable to authenticate");
4744 connection_fatal("Unable to authenticate");
4745 ssh->state = SSH_STATE_CLOSED;
4749 int ret; /* need not be saved across crReturn */
4750 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
4753 setup_userpass_input(ssh, s->password,
4754 sizeof(s->password), s->echo);
4756 crWaitUntilV(!ispkt);
4757 ret = process_userpass_input(ssh, in, inlen);
4761 c_write_str(ssh, "\r\n");
4765 if (s->method == AUTH_PUBLICKEY_FILE) {
4767 * We have our passphrase. Now try the actual authentication.
4769 struct ssh2_userkey *key;
4771 key = ssh2_load_userkey(cfg.keyfile, s->password);
4772 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
4773 if (key == SSH2_WRONG_PASSPHRASE) {
4774 c_write_str(ssh, "Wrong passphrase\r\n");
4775 s->tried_pubkey_config = FALSE;
4777 c_write_str(ssh, "Unable to load private key\r\n");
4778 s->tried_pubkey_config = TRUE;
4780 /* Send a spurious AUTH_NONE to return to the top. */
4781 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4782 ssh2_pkt_addstring(ssh, s->username);
4783 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4784 ssh2_pkt_addstring(ssh, "none"); /* method */
4786 s->type = AUTH_TYPE_NONE;
4788 unsigned char *pkblob, *sigblob, *sigdata;
4789 int pkblob_len, sigblob_len, sigdata_len;
4792 * We have loaded the private key and the server
4793 * has announced that it's willing to accept it.
4794 * Hallelujah. Generate a signature and send it.
4796 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4797 ssh2_pkt_addstring(ssh, s->username);
4798 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4799 ssh2_pkt_addstring(ssh, "publickey"); /* method */
4800 ssh2_pkt_addbool(ssh, TRUE);
4801 ssh2_pkt_addstring(ssh, key->alg->name);
4802 pkblob = key->alg->public_blob(key->data, &pkblob_len);
4803 ssh2_pkt_addstring_start(ssh);
4804 ssh2_pkt_addstring_data(ssh, pkblob, pkblob_len);
4807 * The data to be signed is:
4811 * followed by everything so far placed in the
4814 sigdata_len = ssh->pktout.length - 5 + 4 + 20;
4815 sigdata = smalloc(sigdata_len);
4816 PUT_32BIT(sigdata, 20);
4817 memcpy(sigdata + 4, ssh->v2_session_id, 20);
4818 memcpy(sigdata + 24, ssh->pktout.data + 5,
4819 ssh->pktout.length - 5);
4820 sigblob = key->alg->sign(key->data, sigdata,
4821 sigdata_len, &sigblob_len);
4822 ssh2_add_sigblob(ssh, pkblob, pkblob_len,
4823 sigblob, sigblob_len);
4829 s->type = AUTH_TYPE_PUBLICKEY;
4831 } else if (s->method == AUTH_PASSWORD) {
4833 * We send the password packet lumped tightly together with
4834 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
4835 * string long enough to make the total length of the two
4836 * packets constant. This should ensure that a passive
4837 * listener doing traffic analyis can't work out the length
4840 * For this to work, we need an assumption about the
4841 * maximum length of the password packet. I think 256 is
4842 * pretty conservative. Anyone using a password longer than
4843 * that probably doesn't have much to worry about from
4844 * people who find out how long their password is!
4846 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_REQUEST);
4847 ssh2_pkt_addstring(ssh, s->username);
4848 ssh2_pkt_addstring(ssh, "ssh-connection"); /* service requested */
4849 ssh2_pkt_addstring(ssh, "password");
4850 ssh2_pkt_addbool(ssh, FALSE);
4851 ssh2_pkt_addstring(ssh, s->password);
4852 ssh2_pkt_defer(ssh);
4854 * We'll include a string that's an exact multiple of the
4855 * cipher block size. If the cipher is NULL for some
4856 * reason, we don't do this trick at all because we gain
4859 if (ssh->cscipher) {
4862 stringlen = (256 - ssh->deferred_len);
4863 stringlen += ssh->cscipher->blksize - 1;
4864 stringlen -= (stringlen % ssh->cscipher->blksize);
4867 * Temporarily disable actual compression,
4868 * so we can guarantee to get this string
4869 * exactly the length we want it. The
4870 * compression-disabling routine should
4871 * return an integer indicating how many
4872 * bytes we should adjust our string length
4875 stringlen -= ssh->cscomp->disable_compression();
4877 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
4878 ssh2_pkt_addstring_start(ssh);
4879 for (i = 0; i < stringlen; i++) {
4880 char c = (char) random_byte();
4881 ssh2_pkt_addstring_data(ssh, &c, 1);
4883 ssh2_pkt_defer(ssh);
4885 ssh_pkt_defersend(ssh);
4886 logevent("Sent password");
4887 s->type = AUTH_TYPE_PASSWORD;
4888 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
4889 if (s->curr_prompt == 0) {
4890 ssh2_pkt_init(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE);
4891 ssh2_pkt_adduint32(ssh, s->num_prompts);
4893 if (s->need_pw) { /* only add pw if we just got one! */
4894 ssh2_pkt_addstring(ssh, s->password);
4895 memset(s->password, 0, sizeof(s->password));
4898 if (s->curr_prompt >= s->num_prompts) {
4902 * If there are prompts remaining, we set
4903 * `gotit' so that we won't attempt to get
4904 * another packet. Then we go back round the
4905 * loop and will end up retrieving another
4906 * prompt out of the existing packet. Funky or
4911 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
4913 c_write_str(ssh, "No supported authentication methods"
4914 " left to try!\r\n");
4915 logevent("No supported authentications offered."
4917 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
4918 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
4919 ssh2_pkt_addstring(ssh, "No supported authentication"
4920 " methods available");
4921 ssh2_pkt_addstring(ssh, "en"); /* language tag */
4923 ssh->state = SSH_STATE_CLOSED;
4927 } while (!s->we_are_in);
4930 * Now we're authenticated for the connection protocol. The
4931 * connection protocol will automatically have started at this
4932 * point; there's no need to send SERVICE_REQUEST.
4936 * So now create a channel with a session in it.
4938 ssh->channels = newtree234(ssh_channelcmp);
4939 ssh->mainchan = smalloc(sizeof(struct ssh_channel));
4940 ssh->mainchan->ssh = ssh;
4941 ssh->mainchan->localid = alloc_channel_id(ssh);
4942 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
4943 ssh2_pkt_addstring(ssh, "session");
4944 ssh2_pkt_adduint32(ssh, ssh->mainchan->localid);
4945 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
4946 ssh2_pkt_adduint32(ssh, ssh->mainchan->v.v2.locwindow);/* our window size */
4947 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
4949 crWaitUntilV(ispkt);
4950 if (ssh->pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
4951 bombout(("Server refused to open a session"));
4953 /* FIXME: error data comes back in FAILURE packet */
4955 if (ssh2_pkt_getuint32(ssh) != ssh->mainchan->localid) {
4956 bombout(("Server's channel confirmation cited wrong channel"));
4959 ssh->mainchan->remoteid = ssh2_pkt_getuint32(ssh);
4960 ssh->mainchan->type = CHAN_MAINSESSION;
4961 ssh->mainchan->closes = 0;
4962 ssh->mainchan->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
4963 ssh->mainchan->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
4964 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
4965 add234(ssh->channels, ssh->mainchan);
4966 logevent("Opened channel for session");
4969 * Potentially enable X11 forwarding.
4971 if (cfg.x11_forward) {
4972 char proto[20], data[64];
4973 logevent("Requesting X11 forwarding");
4974 x11_invent_auth(proto, sizeof(proto), data, sizeof(data));
4975 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
4976 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
4977 ssh2_pkt_addstring(ssh, "x11-req");
4978 ssh2_pkt_addbool(ssh, 1); /* want reply */
4979 ssh2_pkt_addbool(ssh, 0); /* many connections */
4980 ssh2_pkt_addstring(ssh, proto);
4981 ssh2_pkt_addstring(ssh, data);
4982 ssh2_pkt_adduint32(ssh, 0); /* screen number */
4986 crWaitUntilV(ispkt);
4987 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
4988 unsigned i = ssh2_pkt_getuint32(ssh);
4989 struct ssh_channel *c;
4990 c = find234(ssh->channels, &i, ssh_channelfind);
4992 continue; /* nonexistent channel */
4993 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
4995 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
4997 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
4998 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
4999 bombout(("Unexpected response to X11 forwarding request:"
5000 " packet type %d", ssh->pktin.type));
5003 logevent("X11 forwarding refused");
5005 logevent("X11 forwarding enabled");
5006 ssh->X11_fwd_enabled = TRUE;
5011 * Enable port forwardings.
5016 int sport,dport,sserv,dserv;
5017 char sports[256], dports[256], host[256];
5021 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
5022 /* Add port forwardings. */
5023 ssh->portfwd_strptr = cfg.portfwd;
5024 while (*ssh->portfwd_strptr) {
5025 type = *ssh->portfwd_strptr++;
5027 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != '\t')
5028 sports[n++] = *ssh->portfwd_strptr++;
5030 if (*ssh->portfwd_strptr == '\t')
5031 ssh->portfwd_strptr++;
5033 while (*ssh->portfwd_strptr && *ssh->portfwd_strptr != ':')
5034 host[n++] = *ssh->portfwd_strptr++;
5036 if (*ssh->portfwd_strptr == ':')
5037 ssh->portfwd_strptr++;
5039 while (*ssh->portfwd_strptr)
5040 dports[n++] = *ssh->portfwd_strptr++;
5042 ssh->portfwd_strptr++;
5043 dport = atoi(dports);
5047 se = getservbyname(dports, NULL);
5049 dport = ntohs(se->s_port);
5052 "Service lookup failed for destination port \"%s\"",
5057 sport = atoi(sports);
5061 se = getservbyname(sports, NULL);
5063 sport = ntohs(se->s_port);
5066 "Service lookup failed for source port \"%s\"",
5071 if (sport && dport) {
5073 pfd_addforward(host, dport, sport);
5074 sprintf(buf, "Local port %.*s%.*s%d%.*s forwarding to"
5075 " %s:%.*s%.*s%d%.*s",
5076 sserv ? strlen(sports) : 0, sports,
5077 sserv, "(", sport, sserv, ")",
5079 dserv ? strlen(dports) : 0, dports,
5080 dserv, "(", dport, dserv, ")");
5083 struct ssh_rportfwd *pf;
5084 pf = smalloc(sizeof(*pf));
5085 strcpy(pf->dhost, host);
5088 if (add234(ssh->rportfwds, pf) != pf) {
5090 "Duplicate remote port forwarding to %s:%d",
5095 sprintf(buf, "Requesting remote port %.*s%.*s%d%.*s"
5096 " forward to %s:%.*s%.*s%d%.*s",
5097 sserv ? strlen(sports) : 0, sports,
5098 sserv, "(", sport, sserv, ")",
5100 dserv ? strlen(dports) : 0, dports,
5101 dserv, "(", dport, dserv, ")");
5103 ssh2_pkt_init(ssh, SSH2_MSG_GLOBAL_REQUEST);
5104 ssh2_pkt_addstring(ssh, "tcpip-forward");
5105 ssh2_pkt_addbool(ssh, 1);/* want reply */
5106 if (cfg.rport_acceptall)
5107 ssh2_pkt_addstring(ssh, "0.0.0.0");
5109 ssh2_pkt_addstring(ssh, "127.0.0.1");
5110 ssh2_pkt_adduint32(ssh, sport);
5114 crWaitUntilV(ispkt);
5115 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5116 unsigned i = ssh2_pkt_getuint32(ssh);
5117 struct ssh_channel *c;
5118 c = find234(ssh->channels, &i, ssh_channelfind);
5120 continue;/* nonexistent channel */
5121 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5123 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5125 if (ssh->pktin.type != SSH2_MSG_REQUEST_SUCCESS) {
5126 if (ssh->pktin.type != SSH2_MSG_REQUEST_FAILURE) {
5127 bombout(("Unexpected response to port "
5128 "forwarding request: packet type %d",
5132 logevent("Server refused this port forwarding");
5134 logevent("Remote port forwarding enabled");
5143 * Potentially enable agent forwarding.
5145 if (cfg.agentfwd && agent_exists()) {
5146 logevent("Requesting OpenSSH-style agent forwarding");
5147 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5148 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5149 ssh2_pkt_addstring(ssh, "auth-agent-req@openssh.com");
5150 ssh2_pkt_addbool(ssh, 1); /* want reply */
5154 crWaitUntilV(ispkt);
5155 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5156 unsigned i = ssh2_pkt_getuint32(ssh);
5157 struct ssh_channel *c;
5158 c = find234(ssh->channels, &i, ssh_channelfind);
5160 continue; /* nonexistent channel */
5161 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5163 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5165 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5166 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5167 bombout(("Unexpected response to agent forwarding request:"
5168 " packet type %d", ssh->pktin.type));
5171 logevent("Agent forwarding refused");
5173 logevent("Agent forwarding enabled");
5174 ssh->agentfwd_enabled = TRUE;
5179 * Now allocate a pty for the session.
5182 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5183 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5184 ssh2_pkt_addstring(ssh, "pty-req");
5185 ssh2_pkt_addbool(ssh, 1); /* want reply */
5186 ssh2_pkt_addstring(ssh, cfg.termtype);
5187 ssh2_pkt_adduint32(ssh, ssh->term_width);
5188 ssh2_pkt_adduint32(ssh, ssh->term_height);
5189 ssh2_pkt_adduint32(ssh, 0); /* pixel width */
5190 ssh2_pkt_adduint32(ssh, 0); /* pixel height */
5191 ssh2_pkt_addstring_start(ssh);
5192 ssh2_pkt_addstring_data(ssh, "\0", 1); /* TTY_OP_END, no special options */
5194 ssh->state = SSH_STATE_INTERMED;
5197 crWaitUntilV(ispkt);
5198 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5199 unsigned i = ssh2_pkt_getuint32(ssh);
5200 struct ssh_channel *c;
5201 c = find234(ssh->channels, &i, ssh_channelfind);
5203 continue; /* nonexistent channel */
5204 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5206 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5208 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5209 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5210 bombout(("Unexpected response to pty request:"
5211 " packet type %d", ssh->pktin.type));
5214 c_write_str(ssh, "Server refused to allocate pty\r\n");
5215 ssh->editing = ssh->echoing = 1;
5217 logevent("Allocated pty");
5220 ssh->editing = ssh->echoing = 1;
5224 * Start a shell or a remote command. We may have to attempt
5225 * this twice if the config data has provided a second choice
5232 if (ssh->fallback_cmd) {
5233 subsys = cfg.ssh_subsys2;
5234 cmd = cfg.remote_cmd_ptr2;
5236 subsys = cfg.ssh_subsys;
5237 cmd = cfg.remote_cmd_ptr;
5240 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5241 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid); /* recipient channel */
5243 ssh2_pkt_addstring(ssh, "subsystem");
5244 ssh2_pkt_addbool(ssh, 1); /* want reply */
5245 ssh2_pkt_addstring(ssh, cmd);
5247 ssh2_pkt_addstring(ssh, "exec");
5248 ssh2_pkt_addbool(ssh, 1); /* want reply */
5249 ssh2_pkt_addstring(ssh, cmd);
5251 ssh2_pkt_addstring(ssh, "shell");
5252 ssh2_pkt_addbool(ssh, 1); /* want reply */
5256 crWaitUntilV(ispkt);
5257 if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5258 unsigned i = ssh2_pkt_getuint32(ssh);
5259 struct ssh_channel *c;
5260 c = find234(ssh->channels, &i, ssh_channelfind);
5262 continue; /* nonexistent channel */
5263 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5265 } while (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5266 if (ssh->pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
5267 if (ssh->pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
5268 bombout(("Unexpected response to shell/command request:"
5269 " packet type %d", ssh->pktin.type));
5273 * We failed to start the command. If this is the
5274 * fallback command, we really are finished; if it's
5275 * not, and if the fallback command exists, try falling
5276 * back to it before complaining.
5278 if (!ssh->fallback_cmd && cfg.remote_cmd_ptr2 != NULL) {
5279 logevent("Primary command failed; attempting fallback");
5280 ssh->fallback_cmd = TRUE;
5283 bombout(("Server refused to start a shell/command"));
5286 logevent("Started a shell/command");
5291 ssh->state = SSH_STATE_SESSION;
5292 if (ssh->size_needed)
5293 ssh_size(ssh, ssh->term_width, ssh->term_height);
5294 if (ssh->eof_needed)
5295 ssh_special(ssh, TS_EOF);
5300 ldisc_send(NULL, 0, 0); /* cause ldisc to notice changes */
5304 s->try_send = FALSE;
5306 if (ssh->pktin.type == SSH2_MSG_CHANNEL_DATA ||
5307 ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
5310 unsigned i = ssh2_pkt_getuint32(ssh);
5311 struct ssh_channel *c;
5312 c = find234(ssh->channels, &i, ssh_channelfind);
5314 continue; /* nonexistent channel */
5315 if (ssh->pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5316 ssh2_pkt_getuint32(ssh) != SSH2_EXTENDED_DATA_STDERR)
5317 continue; /* extended but not stderr */
5318 ssh2_pkt_getstring(ssh, &data, &length);
5321 c->v.v2.locwindow -= length;
5323 case CHAN_MAINSESSION:
5325 from_backend(ssh->frontend, ssh->pktin.type ==
5326 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5330 bufsize = x11_send(c->u.x11.s, data, length);
5333 bufsize = pfd_send(c->u.pfd.s, data, length);
5336 while (length > 0) {
5337 if (c->u.a.lensofar < 4) {
5338 int l = min(4 - c->u.a.lensofar, length);
5339 memcpy(c->u.a.msglen + c->u.a.lensofar,
5343 c->u.a.lensofar += l;
5345 if (c->u.a.lensofar == 4) {
5347 4 + GET_32BIT(c->u.a.msglen);
5348 c->u.a.message = smalloc(c->u.a.totallen);
5349 memcpy(c->u.a.message, c->u.a.msglen, 4);
5351 if (c->u.a.lensofar >= 4 && length > 0) {
5353 min(c->u.a.totallen - c->u.a.lensofar,
5355 memcpy(c->u.a.message + c->u.a.lensofar,
5359 c->u.a.lensofar += l;
5361 if (c->u.a.lensofar == c->u.a.totallen) {
5362 void *reply, *sentreply;
5364 agent_query(c->u.a.message,
5365 c->u.a.totallen, &reply,
5370 /* Fake SSH_AGENT_FAILURE. */
5371 sentreply = "\0\0\0\1\5";
5374 ssh2_add_channel_data(c, sentreply, replylen);
5378 sfree(c->u.a.message);
5379 c->u.a.lensofar = 0;
5386 * If we are not buffering too much data,
5387 * enlarge the window again at the remote side.
5389 if (bufsize < OUR_V2_WINSIZE)
5390 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5392 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_EOF) {
5393 unsigned i = ssh2_pkt_getuint32(ssh);
5394 struct ssh_channel *c;
5396 c = find234(ssh->channels, &i, ssh_channelfind);
5398 continue; /* nonexistent channel */
5400 if (c->type == CHAN_X11) {
5402 * Remote EOF on an X11 channel means we should
5403 * wrap up and close the channel ourselves.
5405 x11_close(c->u.x11.s);
5407 } else if (c->type == CHAN_AGENT) {
5409 } else if (c->type == CHAN_SOCKDATA) {
5410 pfd_close(c->u.pfd.s);
5413 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
5414 unsigned i = ssh2_pkt_getuint32(ssh);
5415 struct ssh_channel *c;
5417 c = find234(ssh->channels, &i, ssh_channelfind);
5418 if (!c || ((int)c->remoteid) == -1) {
5419 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5420 c ? "half-open" : "nonexistent", i));
5422 /* Do pre-close processing on the channel. */
5424 case CHAN_MAINSESSION:
5425 break; /* nothing to see here, move along */
5427 if (c->u.x11.s != NULL)
5428 x11_close(c->u.x11.s);
5435 if (c->u.pfd.s != NULL)
5436 pfd_close(c->u.pfd.s);
5440 if (c->closes == 0) {
5441 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5442 ssh2_pkt_adduint32(ssh, c->remoteid);
5445 del234(ssh->channels, c);
5446 bufchain_clear(&c->v.v2.outbuffer);
5450 * See if that was the last channel left open.
5452 if (count234(ssh->channels) == 0) {
5455 * We used to send SSH_MSG_DISCONNECT here,
5456 * because I'd believed that _every_ conforming
5457 * SSH2 connection had to end with a disconnect
5458 * being sent by at least one side; apparently
5459 * I was wrong and it's perfectly OK to
5460 * unceremoniously slam the connection shut
5461 * when you're done, and indeed OpenSSH feels
5462 * this is more polite than sending a
5463 * DISCONNECT. So now we don't.
5465 logevent("All channels closed. Disconnecting");
5466 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5467 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5468 ssh2_pkt_addstring(ssh, "All open channels closed");
5469 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5472 ssh->state = SSH_STATE_CLOSED;
5475 continue; /* remote sends close; ignore (FIXME) */
5476 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
5477 unsigned i = ssh2_pkt_getuint32(ssh);
5478 struct ssh_channel *c;
5479 c = find234(ssh->channels, &i, ssh_channelfind);
5481 continue; /* nonexistent channel */
5482 c->v.v2.remwindow += ssh2_pkt_getuint32(ssh);
5484 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
5485 unsigned i = ssh2_pkt_getuint32(ssh);
5486 struct ssh_channel *c;
5487 c = find234(ssh->channels, &i, ssh_channelfind);
5489 continue; /* nonexistent channel */
5490 if (c->type != CHAN_SOCKDATA_DORMANT)
5491 continue; /* dunno why they're confirming this */
5492 c->remoteid = ssh2_pkt_getuint32(ssh);
5493 c->type = CHAN_SOCKDATA;
5494 c->v.v2.remwindow = ssh2_pkt_getuint32(ssh);
5495 c->v.v2.remmaxpkt = ssh2_pkt_getuint32(ssh);
5497 pfd_confirm(c->u.pfd.s);
5500 * We have a pending close on this channel,
5501 * which we decided on before the server acked
5502 * the channel open. So now we know the
5503 * remoteid, we can close it again.
5505 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_CLOSE);
5506 ssh2_pkt_adduint32(ssh, c->remoteid);
5509 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN_FAILURE) {
5510 unsigned i = ssh2_pkt_getuint32(ssh);
5511 struct ssh_channel *c;
5512 c = find234(ssh->channels, &i, ssh_channelfind);
5514 continue; /* nonexistent channel */
5515 if (c->type != CHAN_SOCKDATA_DORMANT)
5516 continue; /* dunno why they're failing this */
5518 logevent("Forwarded connection refused by server");
5520 pfd_close(c->u.pfd.s);
5522 del234(ssh->channels, c);
5524 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
5527 int typelen, want_reply;
5528 struct ssh_channel *c;
5530 localid = ssh2_pkt_getuint32(ssh);
5531 ssh2_pkt_getstring(ssh, &type, &typelen);
5532 want_reply = ssh2_pkt_getbool(ssh);
5535 * First, check that the channel exists. Otherwise,
5536 * we can instantly disconnect with a rude message.
5538 c = find234(ssh->channels, &localid, ssh_channelfind);
5541 sprintf(buf, "Received channel request for nonexistent"
5542 " channel %d", localid);
5544 ssh2_pkt_init(ssh, SSH2_MSG_DISCONNECT);
5545 ssh2_pkt_adduint32(ssh, SSH2_DISCONNECT_BY_APPLICATION);
5546 ssh2_pkt_addstring(ssh, buf);
5547 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5549 connection_fatal("%s", buf);
5550 ssh->state = SSH_STATE_CLOSED;
5555 * Having got the channel number, we now look at
5556 * the request type string to see if it's something
5559 if (typelen == 11 && !memcmp(type, "exit-status", 11) &&
5560 c == ssh->mainchan) {
5561 /* We recognise "exit-status" on the primary channel. */
5563 ssh->exitcode = ssh2_pkt_getuint32(ssh);
5564 sprintf(buf, "Server sent command exit status %d",
5568 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_SUCCESS);
5569 ssh2_pkt_adduint32(ssh, c->remoteid);
5574 * This is a channel request we don't know
5575 * about, so we now either ignore the request
5576 * or respond with CHANNEL_FAILURE, depending
5580 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_FAILURE);
5581 ssh2_pkt_adduint32(ssh, c->remoteid);
5585 } else if (ssh->pktin.type == SSH2_MSG_GLOBAL_REQUEST) {
5587 int typelen, want_reply;
5589 ssh2_pkt_getstring(ssh, &type, &typelen);
5590 want_reply = ssh2_pkt_getbool(ssh);
5593 * We currently don't support any global requests
5594 * at all, so we either ignore the request or
5595 * respond with REQUEST_FAILURE, depending on
5599 ssh2_pkt_init(ssh, SSH2_MSG_REQUEST_FAILURE);
5602 } else if (ssh->pktin.type == SSH2_MSG_CHANNEL_OPEN) {
5606 struct ssh_channel *c;
5607 unsigned remid, winsize, pktsize;
5608 ssh2_pkt_getstring(ssh, &type, &typelen);
5609 c = smalloc(sizeof(struct ssh_channel));
5612 remid = ssh2_pkt_getuint32(ssh);
5613 winsize = ssh2_pkt_getuint32(ssh);
5614 pktsize = ssh2_pkt_getuint32(ssh);
5616 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5617 if (!ssh->X11_fwd_enabled)
5618 error = "X11 forwarding is not enabled";
5619 else if (x11_init(&c->u.x11.s, cfg.x11_display, c) !=
5621 error = "Unable to open an X11 connection";
5625 } else if (typelen == 15 &&
5626 !memcmp(type, "forwarded-tcpip", 15)) {
5627 struct ssh_rportfwd pf, *realpf;
5630 ssh2_pkt_getstring(ssh, &dummy, &dummylen);/* skip address */
5631 pf.sport = ssh2_pkt_getuint32(ssh);
5632 realpf = find234(ssh->rportfwds, &pf, NULL);
5633 if (realpf == NULL) {
5634 error = "Remote port is not recognised";
5636 char *e = pfd_newconnect(&c->u.pfd.s, realpf->dhost,
5639 sprintf(buf, "Received remote port open request for %s:%d",
5640 realpf->dhost, realpf->dport);
5643 sprintf(buf, "Port open failed: %s", e);
5645 error = "Port open failed";
5647 logevent("Forwarded port opened successfully");
5648 c->type = CHAN_SOCKDATA;
5651 } else if (typelen == 22 &&
5652 !memcmp(type, "auth-agent@openssh.com", 3)) {
5653 if (!ssh->agentfwd_enabled)
5654 error = "Agent forwarding is not enabled";
5656 c->type = CHAN_AGENT; /* identify channel type */
5657 c->u.a.lensofar = 0;
5660 error = "Unsupported channel type requested";
5663 c->remoteid = remid;
5665 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE);
5666 ssh2_pkt_adduint32(ssh, c->remoteid);
5667 ssh2_pkt_adduint32(ssh, SSH2_OPEN_CONNECT_FAILED);
5668 ssh2_pkt_addstring(ssh, error);
5669 ssh2_pkt_addstring(ssh, "en"); /* language tag */
5673 c->localid = alloc_channel_id(ssh);
5675 c->v.v2.locwindow = OUR_V2_WINSIZE;
5676 c->v.v2.remwindow = winsize;
5677 c->v.v2.remmaxpkt = pktsize;
5678 bufchain_init(&c->v.v2.outbuffer);
5679 add234(ssh->channels, c);
5680 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5681 ssh2_pkt_adduint32(ssh, c->remoteid);
5682 ssh2_pkt_adduint32(ssh, c->localid);
5683 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);
5684 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
5688 bombout(("Strange packet received: type %d", ssh->pktin.type));
5693 * We have spare data. Add it to the channel buffer.
5695 ssh2_add_channel_data(ssh->mainchan, in, inlen);
5700 struct ssh_channel *c;
5702 * Try to send data on all channels if we can.
5704 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
5705 int bufsize = ssh2_try_send(c);
5708 case CHAN_MAINSESSION:
5709 /* stdin need not receive an unthrottle
5710 * notification since it will be polled */
5713 x11_unthrottle(c->u.x11.s);
5716 /* agent sockets are request/response and need no
5717 * buffer management */
5720 pfd_unthrottle(c->u.pfd.s);
5732 * Handle the top-level SSH2 protocol.
5734 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen, int ispkt)
5736 if (do_ssh2_transport(ssh, in, inlen, ispkt) == 0)
5738 do_ssh2_authconn(ssh, in, inlen, ispkt);
5742 * Called to set up the connection.
5744 * Returns an error message, or NULL on success.
5746 static char *ssh_init(void *frontend_handle, void **backend_handle,
5747 char *host, int port, char **realhost, int nodelay)
5752 ssh = smalloc(sizeof(*ssh));
5755 ssh->cscipher = NULL;
5756 ssh->sccipher = NULL;
5762 ssh->hostkey = NULL;
5764 ssh->state = SSH_STATE_PREPACKET;
5765 ssh->size_needed = FALSE;
5766 ssh->eof_needed = FALSE;
5768 static const struct Packet empty = { 0, 0, NULL, NULL, 0 };
5769 ssh->pktin = ssh->pktout = empty;
5771 ssh->deferred_send_data = NULL;
5772 ssh->deferred_len = 0;
5773 ssh->deferred_size = 0;
5774 ssh->fallback_cmd = 0;
5776 ssh->v2_outgoing_sequence = 0;
5777 ssh->ssh1_rdpkt_crstate = 0;
5778 ssh->ssh2_rdpkt_crstate = 0;
5779 ssh->do_ssh_init_crstate = 0;
5780 ssh->ssh_gotdata_crstate = 0;
5781 ssh->ssh1_protocol_crstate = 0;
5782 ssh->do_ssh1_login_crstate = 0;
5783 ssh->do_ssh2_transport_crstate = 0;
5784 ssh->do_ssh2_authconn_crstate = 0;
5785 ssh->do_ssh_init_state = NULL;
5786 ssh->do_ssh1_login_state = NULL;
5787 ssh->do_ssh2_transport_state = NULL;
5788 ssh->do_ssh2_authconn_state = NULL;
5790 *backend_handle = ssh;
5793 if (crypto_startup() == 0)
5794 return "Microsoft high encryption pack not installed!";
5797 ssh->frontend = frontend_handle;
5798 ssh->term_width = cfg.width;
5799 ssh->term_height = cfg.height;
5804 ssh->v1_throttle_count = 0;
5805 ssh->overall_bufsize = 0;
5806 ssh->fallback_cmd = 0;
5808 p = connect_to_host(ssh, host, port, realhost, nodelay);
5816 * Called to send data down the Telnet connection.
5818 static int ssh_send(void *handle, char *buf, int len)
5820 Ssh ssh = (Ssh) handle;
5822 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5825 ssh->protocol(ssh, buf, len, 0);
5827 return ssh_sendbuffer(ssh);
5831 * Called to query the current amount of buffered stdin data.
5833 static int ssh_sendbuffer(void *handle)
5835 Ssh ssh = (Ssh) handle;
5838 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
5842 * If the SSH socket itself has backed up, add the total backup
5843 * size on that to any individual buffer on the stdin channel.
5846 if (ssh->throttled_all)
5847 override_value = ssh->overall_bufsize;
5849 if (ssh->version == 1) {
5850 return override_value;
5851 } else if (ssh->version == 2) {
5852 if (!ssh->mainchan || ssh->mainchan->closes > 0)
5853 return override_value;
5855 return (override_value +
5856 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
5863 * Called to set the size of the window from SSH's POV.
5865 static void ssh_size(void *handle, int width, int height)
5867 Ssh ssh = (Ssh) handle;
5869 ssh->term_width = width;
5870 ssh->term_height = height;
5872 switch (ssh->state) {
5873 case SSH_STATE_BEFORE_SIZE:
5874 case SSH_STATE_PREPACKET:
5875 case SSH_STATE_CLOSED:
5876 break; /* do nothing */
5877 case SSH_STATE_INTERMED:
5878 ssh->size_needed = TRUE; /* buffer for later */
5880 case SSH_STATE_SESSION:
5884 if (ssh->version == 1) {
5885 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
5886 PKT_INT, ssh->term_height,
5887 PKT_INT, ssh->term_width,
5888 PKT_INT, 0, PKT_INT, 0, PKT_END);
5890 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_REQUEST);
5891 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5892 ssh2_pkt_addstring(ssh, "window-change");
5893 ssh2_pkt_addbool(ssh, 0);
5894 ssh2_pkt_adduint32(ssh, ssh->term_width);
5895 ssh2_pkt_adduint32(ssh, ssh->term_height);
5896 ssh2_pkt_adduint32(ssh, 0);
5897 ssh2_pkt_adduint32(ssh, 0);
5906 * Send Telnet special codes. TS_EOF is useful for `plink', so you
5907 * can send an EOF and collect resulting output (e.g. `plink
5910 static void ssh_special(void *handle, Telnet_Special code)
5912 Ssh ssh = (Ssh) handle;
5914 if (code == TS_EOF) {
5915 if (ssh->state != SSH_STATE_SESSION) {
5917 * Buffer the EOF in case we are pre-SESSION, so we can
5918 * send it as soon as we reach SESSION.
5921 ssh->eof_needed = TRUE;
5924 if (ssh->version == 1) {
5925 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
5927 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_EOF);
5928 ssh2_pkt_adduint32(ssh, ssh->mainchan->remoteid);
5931 logevent("Sent EOF message");
5932 } else if (code == TS_PING) {
5933 if (ssh->state == SSH_STATE_CLOSED
5934 || ssh->state == SSH_STATE_PREPACKET) return;
5935 if (ssh->version == 1) {
5936 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
5937 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
5939 ssh2_pkt_init(ssh, SSH2_MSG_IGNORE);
5940 ssh2_pkt_addstring_start(ssh);
5948 void *new_sock_channel(void *handle, Socket s)
5950 Ssh ssh = (Ssh) handle;
5951 struct ssh_channel *c;
5952 c = smalloc(sizeof(struct ssh_channel));
5956 c->remoteid = -1; /* to be set when open confirmed */
5957 c->localid = alloc_channel_id(ssh);
5959 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
5961 bufchain_init(&c->v.v2.outbuffer);
5962 add234(ssh->channels, c);
5968 * This is called when stdout/stderr (the entity to which
5969 * from_backend sends data) manages to clear some backlog.
5971 void ssh_unthrottle(void *handle, int bufsize)
5973 Ssh ssh = (Ssh) handle;
5974 if (ssh->version == 1) {
5975 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
5976 ssh->v1_stdout_throttling = 0;
5977 ssh1_throttle(ssh, -1);
5980 if (ssh->mainchan && ssh->mainchan->closes == 0)
5981 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
5985 void ssh_send_port_open(void *handle, void *channel, char *hostname,
5986 int port, char *org)
5988 Ssh ssh = (Ssh) handle;
5989 struct ssh_channel *c = (struct ssh_channel *)channel;
5992 sprintf(buf, "Opening forwarded connection to %.512s:%d", hostname, port);
5995 if (ssh->version == 1) {
5996 send_packet(ssh, SSH1_MSG_PORT_OPEN,
5997 PKT_INT, c->localid,
6000 //PKT_STR, <org:orgport>,
6003 ssh2_pkt_init(ssh, SSH2_MSG_CHANNEL_OPEN);
6004 ssh2_pkt_addstring(ssh, "direct-tcpip");
6005 ssh2_pkt_adduint32(ssh, c->localid);
6006 c->v.v2.locwindow = OUR_V2_WINSIZE;
6007 ssh2_pkt_adduint32(ssh, c->v.v2.locwindow);/* our window size */
6008 ssh2_pkt_adduint32(ssh, 0x4000UL); /* our max pkt size */
6009 ssh2_pkt_addstring(ssh, hostname);
6010 ssh2_pkt_adduint32(ssh, port);
6012 * We make up values for the originator data; partly it's
6013 * too much hassle to keep track, and partly I'm not
6014 * convinced the server should be told details like that
6015 * about my local network configuration.
6017 ssh2_pkt_addstring(ssh, "client-side-connection");
6018 ssh2_pkt_adduint32(ssh, 0);
6024 static Socket ssh_socket(void *handle)
6026 Ssh ssh = (Ssh) handle;
6030 static int ssh_sendok(void *handle)
6032 Ssh ssh = (Ssh) handle;
6033 return ssh->send_ok;
6036 static int ssh_ldisc(void *handle, int option)
6038 Ssh ssh = (Ssh) handle;
6039 if (option == LD_ECHO)
6040 return ssh->echoing;
6041 if (option == LD_EDIT)
6042 return ssh->editing;
6046 static int ssh_return_exitcode(void *handle)
6048 Ssh ssh = (Ssh) handle;
6049 return ssh->exitcode;
6053 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
6054 * that fails. This variable is the means by which scp.c can reach
6055 * into the SSH code and find out which one it got.
6057 extern int ssh_fallback_cmd(void *handle)
6059 Ssh ssh = (Ssh) handle;
6060 return ssh->fallback_cmd;
6063 Backend ssh_backend = {
6070 ssh_return_exitcode,