17 #define SSH1_MSG_DISCONNECT 1 /* 0x1 */
18 #define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
19 #define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
20 #define SSH1_CMSG_USER 4 /* 0x4 */
21 #define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
22 #define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
23 #define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
24 #define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
25 #define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
26 #define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
27 #define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
28 #define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
29 #define SSH1_SMSG_SUCCESS 14 /* 0xe */
30 #define SSH1_SMSG_FAILURE 15 /* 0xf */
31 #define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
32 #define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
33 #define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
34 #define SSH1_CMSG_EOF 19 /* 0x13 */
35 #define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
36 #define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
37 #define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
38 #define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
39 #define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
40 #define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
41 #define SSH1_SMSG_X11_OPEN 27 /* 0x1b */
42 #define SSH1_CMSG_PORT_FORWARD_REQUEST 28 /* 0x1c */
43 #define SSH1_MSG_PORT_OPEN 29 /* 0x1d */
44 #define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
45 #define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
46 #define SSH1_MSG_IGNORE 32 /* 0x20 */
47 #define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
48 #define SSH1_CMSG_X11_REQUEST_FORWARDING 34 /* 0x22 */
49 #define SSH1_CMSG_AUTH_RHOSTS_RSA 35 /* 0x23 */
50 #define SSH1_MSG_DEBUG 36 /* 0x24 */
51 #define SSH1_CMSG_REQUEST_COMPRESSION 37 /* 0x25 */
52 #define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
53 #define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
54 #define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
55 #define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
56 #define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
57 #define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
59 #define SSH1_AUTH_TIS 5 /* 0x5 */
60 #define SSH1_AUTH_CCARD 16 /* 0x10 */
62 #define SSH1_PROTOFLAG_SCREEN_NUMBER 1 /* 0x1 */
63 /* Mask for protoflags we will echo back to server if seen */
64 #define SSH1_PROTOFLAGS_SUPPORTED 0 /* 0x1 */
66 #define SSH2_MSG_DISCONNECT 1 /* 0x1 */
67 #define SSH2_MSG_IGNORE 2 /* 0x2 */
68 #define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
69 #define SSH2_MSG_DEBUG 4 /* 0x4 */
70 #define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
71 #define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
72 #define SSH2_MSG_KEXINIT 20 /* 0x14 */
73 #define SSH2_MSG_NEWKEYS 21 /* 0x15 */
74 #define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
75 #define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
76 #define SSH2_MSG_KEX_DH_GEX_REQUEST 30 /* 0x1e */
77 #define SSH2_MSG_KEX_DH_GEX_GROUP 31 /* 0x1f */
78 #define SSH2_MSG_KEX_DH_GEX_INIT 32 /* 0x20 */
79 #define SSH2_MSG_KEX_DH_GEX_REPLY 33 /* 0x21 */
80 #define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
81 #define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
82 #define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
83 #define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
84 #define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
85 #define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
86 #define SSH2_MSG_USERAUTH_INFO_REQUEST 60 /* 0x3c */
87 #define SSH2_MSG_USERAUTH_INFO_RESPONSE 61 /* 0x3d */
88 #define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
89 #define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
90 #define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
91 #define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
92 #define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
93 #define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
94 #define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
95 #define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
96 #define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
97 #define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
98 #define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
99 #define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
100 #define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
101 #define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
104 * Packet type contexts, so that ssh2_pkt_type can correctly decode
105 * the ambiguous type numbers back into the correct type strings.
107 #define SSH2_PKTCTX_DHGROUP 0x0001
108 #define SSH2_PKTCTX_DHGEX 0x0002
109 #define SSH2_PKTCTX_KEX_MASK 0x000F
110 #define SSH2_PKTCTX_PUBLICKEY 0x0010
111 #define SSH2_PKTCTX_PASSWORD 0x0020
112 #define SSH2_PKTCTX_KBDINTER 0x0040
113 #define SSH2_PKTCTX_AUTH_MASK 0x00F0
115 #define SSH2_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT 1 /* 0x1 */
116 #define SSH2_DISCONNECT_PROTOCOL_ERROR 2 /* 0x2 */
117 #define SSH2_DISCONNECT_KEY_EXCHANGE_FAILED 3 /* 0x3 */
118 #define SSH2_DISCONNECT_HOST_AUTHENTICATION_FAILED 4 /* 0x4 */
119 #define SSH2_DISCONNECT_MAC_ERROR 5 /* 0x5 */
120 #define SSH2_DISCONNECT_COMPRESSION_ERROR 6 /* 0x6 */
121 #define SSH2_DISCONNECT_SERVICE_NOT_AVAILABLE 7 /* 0x7 */
122 #define SSH2_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED 8 /* 0x8 */
123 #define SSH2_DISCONNECT_HOST_KEY_NOT_VERIFIABLE 9 /* 0x9 */
124 #define SSH2_DISCONNECT_CONNECTION_LOST 10 /* 0xa */
125 #define SSH2_DISCONNECT_BY_APPLICATION 11 /* 0xb */
126 #define SSH2_DISCONNECT_TOO_MANY_CONNECTIONS 12 /* 0xc */
127 #define SSH2_DISCONNECT_AUTH_CANCELLED_BY_USER 13 /* 0xd */
128 #define SSH2_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE 14 /* 0xe */
129 #define SSH2_DISCONNECT_ILLEGAL_USER_NAME 15 /* 0xf */
131 static const char *const ssh2_disconnect_reasons[] = {
133 "SSH_DISCONNECT_HOST_NOT_ALLOWED_TO_CONNECT",
134 "SSH_DISCONNECT_PROTOCOL_ERROR",
135 "SSH_DISCONNECT_KEY_EXCHANGE_FAILED",
136 "SSH_DISCONNECT_HOST_AUTHENTICATION_FAILED",
137 "SSH_DISCONNECT_MAC_ERROR",
138 "SSH_DISCONNECT_COMPRESSION_ERROR",
139 "SSH_DISCONNECT_SERVICE_NOT_AVAILABLE",
140 "SSH_DISCONNECT_PROTOCOL_VERSION_NOT_SUPPORTED",
141 "SSH_DISCONNECT_HOST_KEY_NOT_VERIFIABLE",
142 "SSH_DISCONNECT_CONNECTION_LOST",
143 "SSH_DISCONNECT_BY_APPLICATION",
144 "SSH_DISCONNECT_TOO_MANY_CONNECTIONS",
145 "SSH_DISCONNECT_AUTH_CANCELLED_BY_USER",
146 "SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE",
147 "SSH_DISCONNECT_ILLEGAL_USER_NAME",
150 #define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
151 #define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
152 #define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
153 #define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
155 #define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
158 * Various remote-bug flags.
160 #define BUG_CHOKES_ON_SSH1_IGNORE 1
161 #define BUG_SSH2_HMAC 2
162 #define BUG_NEEDS_SSH1_PLAIN_PASSWORD 4
163 #define BUG_CHOKES_ON_RSA 8
164 #define BUG_SSH2_RSA_PADDING 16
165 #define BUG_SSH2_DERIVEKEY 32
166 #define BUG_SSH2_REKEY 64
167 #define BUG_SSH2_PK_SESSIONID 128
169 #define translate(x) if (type == x) return #x
170 #define translatec(x,ctx) if (type == x && (pkt_ctx & ctx)) return #x
171 static char *ssh1_pkt_type(int type)
173 translate(SSH1_MSG_DISCONNECT);
174 translate(SSH1_SMSG_PUBLIC_KEY);
175 translate(SSH1_CMSG_SESSION_KEY);
176 translate(SSH1_CMSG_USER);
177 translate(SSH1_CMSG_AUTH_RSA);
178 translate(SSH1_SMSG_AUTH_RSA_CHALLENGE);
179 translate(SSH1_CMSG_AUTH_RSA_RESPONSE);
180 translate(SSH1_CMSG_AUTH_PASSWORD);
181 translate(SSH1_CMSG_REQUEST_PTY);
182 translate(SSH1_CMSG_WINDOW_SIZE);
183 translate(SSH1_CMSG_EXEC_SHELL);
184 translate(SSH1_CMSG_EXEC_CMD);
185 translate(SSH1_SMSG_SUCCESS);
186 translate(SSH1_SMSG_FAILURE);
187 translate(SSH1_CMSG_STDIN_DATA);
188 translate(SSH1_SMSG_STDOUT_DATA);
189 translate(SSH1_SMSG_STDERR_DATA);
190 translate(SSH1_CMSG_EOF);
191 translate(SSH1_SMSG_EXIT_STATUS);
192 translate(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION);
193 translate(SSH1_MSG_CHANNEL_OPEN_FAILURE);
194 translate(SSH1_MSG_CHANNEL_DATA);
195 translate(SSH1_MSG_CHANNEL_CLOSE);
196 translate(SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION);
197 translate(SSH1_SMSG_X11_OPEN);
198 translate(SSH1_CMSG_PORT_FORWARD_REQUEST);
199 translate(SSH1_MSG_PORT_OPEN);
200 translate(SSH1_CMSG_AGENT_REQUEST_FORWARDING);
201 translate(SSH1_SMSG_AGENT_OPEN);
202 translate(SSH1_MSG_IGNORE);
203 translate(SSH1_CMSG_EXIT_CONFIRMATION);
204 translate(SSH1_CMSG_X11_REQUEST_FORWARDING);
205 translate(SSH1_CMSG_AUTH_RHOSTS_RSA);
206 translate(SSH1_MSG_DEBUG);
207 translate(SSH1_CMSG_REQUEST_COMPRESSION);
208 translate(SSH1_CMSG_AUTH_TIS);
209 translate(SSH1_SMSG_AUTH_TIS_CHALLENGE);
210 translate(SSH1_CMSG_AUTH_TIS_RESPONSE);
211 translate(SSH1_CMSG_AUTH_CCARD);
212 translate(SSH1_SMSG_AUTH_CCARD_CHALLENGE);
213 translate(SSH1_CMSG_AUTH_CCARD_RESPONSE);
216 static char *ssh2_pkt_type(int pkt_ctx, int type)
218 translate(SSH2_MSG_DISCONNECT);
219 translate(SSH2_MSG_IGNORE);
220 translate(SSH2_MSG_UNIMPLEMENTED);
221 translate(SSH2_MSG_DEBUG);
222 translate(SSH2_MSG_SERVICE_REQUEST);
223 translate(SSH2_MSG_SERVICE_ACCEPT);
224 translate(SSH2_MSG_KEXINIT);
225 translate(SSH2_MSG_NEWKEYS);
226 translatec(SSH2_MSG_KEXDH_INIT, SSH2_PKTCTX_DHGROUP);
227 translatec(SSH2_MSG_KEXDH_REPLY, SSH2_PKTCTX_DHGROUP);
228 translatec(SSH2_MSG_KEX_DH_GEX_REQUEST, SSH2_PKTCTX_DHGEX);
229 translatec(SSH2_MSG_KEX_DH_GEX_GROUP, SSH2_PKTCTX_DHGEX);
230 translatec(SSH2_MSG_KEX_DH_GEX_INIT, SSH2_PKTCTX_DHGEX);
231 translatec(SSH2_MSG_KEX_DH_GEX_REPLY, SSH2_PKTCTX_DHGEX);
232 translate(SSH2_MSG_USERAUTH_REQUEST);
233 translate(SSH2_MSG_USERAUTH_FAILURE);
234 translate(SSH2_MSG_USERAUTH_SUCCESS);
235 translate(SSH2_MSG_USERAUTH_BANNER);
236 translatec(SSH2_MSG_USERAUTH_PK_OK, SSH2_PKTCTX_PUBLICKEY);
237 translatec(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, SSH2_PKTCTX_PASSWORD);
238 translatec(SSH2_MSG_USERAUTH_INFO_REQUEST, SSH2_PKTCTX_KBDINTER);
239 translatec(SSH2_MSG_USERAUTH_INFO_RESPONSE, SSH2_PKTCTX_KBDINTER);
240 translate(SSH2_MSG_GLOBAL_REQUEST);
241 translate(SSH2_MSG_REQUEST_SUCCESS);
242 translate(SSH2_MSG_REQUEST_FAILURE);
243 translate(SSH2_MSG_CHANNEL_OPEN);
244 translate(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
245 translate(SSH2_MSG_CHANNEL_OPEN_FAILURE);
246 translate(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
247 translate(SSH2_MSG_CHANNEL_DATA);
248 translate(SSH2_MSG_CHANNEL_EXTENDED_DATA);
249 translate(SSH2_MSG_CHANNEL_EOF);
250 translate(SSH2_MSG_CHANNEL_CLOSE);
251 translate(SSH2_MSG_CHANNEL_REQUEST);
252 translate(SSH2_MSG_CHANNEL_SUCCESS);
253 translate(SSH2_MSG_CHANNEL_FAILURE);
259 #define GET_32BIT(cp) \
260 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
261 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
262 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
263 ((unsigned long)(unsigned char)(cp)[3]))
265 #define PUT_32BIT(cp, value) { \
266 (cp)[0] = (unsigned char)((value) >> 24); \
267 (cp)[1] = (unsigned char)((value) >> 16); \
268 (cp)[2] = (unsigned char)((value) >> 8); \
269 (cp)[3] = (unsigned char)(value); }
271 /* Enumeration values for fields in SSH-1 packets */
273 PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM,
274 /* These values are for communicating relevant semantics of
275 * fields to the packet logging code. */
276 PKTT_OTHER, PKTT_PASSWORD, PKTT_DATA
280 * Coroutine mechanics for the sillier bits of the code. If these
281 * macros look impenetrable to you, you might find it helpful to
284 * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
286 * which explains the theory behind these macros.
288 * In particular, if you are getting `case expression not constant'
289 * errors when building with MS Visual Studio, this is because MS's
290 * Edit and Continue debugging feature causes their compiler to
291 * violate ANSI C. To disable Edit and Continue debugging:
293 * - right-click ssh.c in the FileView
295 * - select the C/C++ tab and the General category
296 * - under `Debug info:', select anything _other_ than `Program
297 * Database for Edit and Continue'.
299 #define crBegin(v) { int *crLine = &v; switch(v) { case 0:;
302 if (!ssh->t) ssh->t = snew(struct t); \
304 #define crFinish(z) } *crLine = 0; return (z); }
305 #define crFinishV } *crLine = 0; return; }
306 #define crReturn(z) \
308 *crLine =__LINE__; return (z); case __LINE__:;\
312 *crLine=__LINE__; return; case __LINE__:;\
314 #define crStop(z) do{ *crLine = 0; return (z); }while(0)
315 #define crStopV do{ *crLine = 0; return; }while(0)
316 #define crWaitUntil(c) do { crReturn(0); } while (!(c))
317 #define crWaitUntilV(c) do { crReturnV; } while (!(c))
319 typedef struct ssh_tag *Ssh;
322 static struct Packet *ssh2_pkt_init(int pkt_type);
323 static void ssh2_pkt_addbool(struct Packet *, unsigned char value);
324 static void ssh2_pkt_adduint32(struct Packet *, unsigned long value);
325 static void ssh2_pkt_addstring_start(struct Packet *);
326 static void ssh2_pkt_addstring_str(struct Packet *, char *data);
327 static void ssh2_pkt_addstring_data(struct Packet *, char *data, int len);
328 static void ssh2_pkt_addstring(struct Packet *, char *data);
329 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len);
330 static void ssh2_pkt_addmp(struct Packet *, Bignum b);
331 static int ssh2_pkt_construct(Ssh, struct Packet *);
332 static void ssh2_pkt_send(Ssh, struct Packet *);
333 static void ssh2_pkt_send_noqueue(Ssh, struct Packet *);
334 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
335 struct Packet *pktin);
336 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
337 struct Packet *pktin);
340 * Buffer management constants. There are several of these for
341 * various different purposes:
343 * - SSH1_BUFFER_LIMIT is the amount of backlog that must build up
344 * on a local data stream before we throttle the whole SSH
345 * connection (in SSH1 only). Throttling the whole connection is
346 * pretty drastic so we set this high in the hope it won't
349 * - SSH_MAX_BACKLOG is the amount of backlog that must build up
350 * on the SSH connection itself before we defensively throttle
351 * _all_ local data streams. This is pretty drastic too (though
352 * thankfully unlikely in SSH2 since the window mechanism should
353 * ensure that the server never has any need to throttle its end
354 * of the connection), so we set this high as well.
356 * - OUR_V2_WINSIZE is the maximum window size we present on SSH2
360 #define SSH1_BUFFER_LIMIT 32768
361 #define SSH_MAX_BACKLOG 32768
362 #define OUR_V2_WINSIZE 16384
364 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
366 static void *nullmac_make_context(void)
370 static void nullmac_free_context(void *handle)
373 static void nullmac_key(void *handle, unsigned char *key)
376 static void nullmac_generate(void *handle, unsigned char *blk, int len,
380 static int nullmac_verify(void *handle, unsigned char *blk, int len,
385 const static struct ssh_mac ssh_mac_none = {
386 nullmac_make_context, nullmac_free_context, nullmac_key,
387 nullmac_generate, nullmac_verify, "none", 0
389 const static struct ssh_mac *macs[] = {
390 &ssh_sha1, &ssh_md5, &ssh_mac_none
392 const static struct ssh_mac *buggymacs[] = {
393 &ssh_sha1_buggy, &ssh_md5, &ssh_mac_none
396 static void *ssh_comp_none_init(void)
400 static void ssh_comp_none_cleanup(void *handle)
403 static int ssh_comp_none_block(void *handle, unsigned char *block, int len,
404 unsigned char **outblock, int *outlen)
408 static int ssh_comp_none_disable(void *handle)
412 const static struct ssh_compress ssh_comp_none = {
414 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
415 ssh_comp_none_init, ssh_comp_none_cleanup, ssh_comp_none_block,
416 ssh_comp_none_disable, NULL
418 extern const struct ssh_compress ssh_zlib;
419 const static struct ssh_compress *compressions[] = {
420 &ssh_zlib, &ssh_comp_none
423 enum { /* channel types */
428 CHAN_SOCKDATA_DORMANT /* one the remote hasn't confirmed */
432 * 2-3-4 tree storing channels.
435 Ssh ssh; /* pointer back to main context */
436 unsigned remoteid, localid;
439 * In SSH1, this value contains four bits:
441 * 1 We have sent SSH1_MSG_CHANNEL_CLOSE.
442 * 2 We have sent SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
443 * 4 We have received SSH1_MSG_CHANNEL_CLOSE.
444 * 8 We have received SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION.
446 * A channel is completely finished with when all four bits are set.
450 struct ssh1_data_channel {
453 struct ssh2_data_channel {
455 unsigned remwindow, remmaxpkt;
460 struct ssh_agent_channel {
461 unsigned char *message;
462 unsigned char msglen[4];
463 unsigned lensofar, totallen;
465 struct ssh_x11_channel {
468 struct ssh_pfd_channel {
475 * 2-3-4 tree storing remote->local port forwardings. SSH 1 and SSH
476 * 2 use this structure in different ways, reflecting SSH 2's
477 * altogether saner approach to port forwarding.
479 * In SSH 1, you arrange a remote forwarding by sending the server
480 * the remote port number, and the local destination host:port.
481 * When a connection comes in, the server sends you back that
482 * host:port pair, and you connect to it. This is a ready-made
483 * security hole if you're not on the ball: a malicious server
484 * could send you back _any_ host:port pair, so if you trustingly
485 * connect to the address it gives you then you've just opened the
486 * entire inside of your corporate network just by connecting
487 * through it to a dodgy SSH server. Hence, we must store a list of
488 * host:port pairs we _are_ trying to forward to, and reject a
489 * connection request from the server if it's not in the list.
491 * In SSH 2, each side of the connection minds its own business and
492 * doesn't send unnecessary information to the other. You arrange a
493 * remote forwarding by sending the server just the remote port
494 * number. When a connection comes in, the server tells you which
495 * of its ports was connected to; and _you_ have to remember what
496 * local host:port pair went with that port number.
498 * Hence, in SSH 1 this structure is indexed by destination
499 * host:port pair, whereas in SSH 2 it is indexed by source port.
501 struct ssh_portfwd; /* forward declaration */
503 struct ssh_rportfwd {
504 unsigned sport, dport;
507 struct ssh_portfwd *pfrec;
509 #define free_rportfwd(pf) ( \
510 ((pf) ? (sfree((pf)->sportdesc)) : (void)0 ), sfree(pf) )
513 * Separately to the rportfwd tree (which is for looking up port
514 * open requests from the server), a tree of _these_ structures is
515 * used to keep track of all the currently open port forwardings,
516 * so that we can reconfigure in mid-session if the user requests
520 enum { DESTROY, KEEP, CREATE } status;
522 unsigned sport, dport;
525 struct ssh_rportfwd *remote;
529 #define free_portfwd(pf) ( \
530 ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
531 sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
536 unsigned long sequence;
541 long encrypted_len; /* for SSH2 total-size counting */
544 * State associated with packet logging
548 struct logblank_t *blanks;
551 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
552 struct Packet *pktin);
553 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
554 struct Packet *pktin);
555 static void ssh1_protocol_setup(Ssh ssh);
556 static void ssh2_protocol_setup(Ssh ssh);
557 static void ssh_size(void *handle, int width, int height);
558 static void ssh_special(void *handle, Telnet_Special);
559 static int ssh2_try_send(struct ssh_channel *c);
560 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
561 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
562 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
563 static int ssh_sendbuffer(void *handle);
564 static void ssh_do_close(Ssh ssh);
565 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
566 static int ssh2_pkt_getbool(struct Packet *pkt);
567 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
568 static void ssh2_timer(void *ctx, long now);
569 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
570 struct Packet *pktin);
572 struct rdpkt1_state_tag {
573 long len, pad, biglen, to_read;
574 unsigned long realcrc, gotcrc;
578 struct Packet *pktin;
581 struct rdpkt2_state_tag {
582 long len, pad, payload, packetlen, maclen;
585 unsigned long incoming_sequence;
586 struct Packet *pktin;
589 typedef void (*handler_fn_t)(Ssh ssh, struct Packet *pktin);
590 typedef void (*chandler_fn_t)(Ssh ssh, struct Packet *pktin, void *ctx);
592 struct queued_handler;
593 struct queued_handler {
595 chandler_fn_t handler;
597 struct queued_handler *next;
601 const struct plug_function_table *fn;
602 /* the above field _must_ be first in the structure */
604 SHA_State exhash, exhashbase;
611 unsigned char session_key[32];
613 int v1_remote_protoflags;
614 int v1_local_protoflags;
615 int agentfwd_enabled;
618 const struct ssh_cipher *cipher;
621 const struct ssh2_cipher *cscipher, *sccipher;
622 void *cs_cipher_ctx, *sc_cipher_ctx;
623 const struct ssh_mac *csmac, *scmac;
624 void *cs_mac_ctx, *sc_mac_ctx;
625 const struct ssh_compress *cscomp, *sccomp;
626 void *cs_comp_ctx, *sc_comp_ctx;
627 const struct ssh_kex *kex;
628 const struct ssh_signkey *hostkey;
629 unsigned char v2_session_id[20];
635 int echoing, editing;
639 int ospeed, ispeed; /* temporaries */
640 int term_width, term_height;
642 tree234 *channels; /* indexed by local id */
643 struct ssh_channel *mainchan; /* primary session channel */
646 tree234 *rportfwds, *portfwds;
650 SSH_STATE_BEFORE_SIZE,
656 int size_needed, eof_needed;
658 struct Packet **queue;
659 int queuelen, queuesize;
661 unsigned char *deferred_send_data;
662 int deferred_len, deferred_size;
665 * Gross hack: pscp will try to start SFTP but fall back to
666 * scp1 if that fails. This variable is the means by which
667 * scp.c can reach into the SSH code and find out which one it
673 * Used for username and password input.
675 char *userpass_input_buffer;
676 int userpass_input_buflen;
677 int userpass_input_bufpos;
678 int userpass_input_echo;
685 int v1_throttle_count;
688 int v1_stdout_throttling;
689 int v2_outgoing_sequence;
691 int ssh1_rdpkt_crstate;
692 int ssh2_rdpkt_crstate;
693 int do_ssh_init_crstate;
694 int ssh_gotdata_crstate;
695 int do_ssh1_login_crstate;
696 int do_ssh1_connection_crstate;
697 int do_ssh2_transport_crstate;
698 int do_ssh2_authconn_crstate;
700 void *do_ssh_init_state;
701 void *do_ssh1_login_state;
702 void *do_ssh2_transport_state;
703 void *do_ssh2_authconn_state;
705 struct rdpkt1_state_tag rdpkt1_state;
706 struct rdpkt2_state_tag rdpkt2_state;
708 /* ssh1 and ssh2 use this for different things, but both use it */
709 int protocol_initial_phase_done;
711 void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
713 struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
716 * We maintain a full _copy_ of a Config structure here, not
717 * merely a pointer to it. That way, when we're passed a new
718 * one for reconfiguration, we can check the differences and
719 * potentially reconfigure port forwardings etc in mid-session.
724 * Used to transfer data back from async agent callbacks.
726 void *agent_response;
727 int agent_response_len;
730 * Dispatch table for packet types that we may have to deal
733 handler_fn_t packet_dispatch[256];
736 * Queues of one-off handler functions for success/failure
737 * indications from a request.
739 struct queued_handler *qhead, *qtail;
742 * This module deals with sending keepalives.
747 * Track incoming and outgoing data sizes and time, for
750 unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
751 unsigned long max_data_size;
753 long next_rekey, last_rekey;
754 char *deferred_rekey_reason; /* points to STATIC string; don't free */
757 #define logevent(s) logevent(ssh->frontend, s)
759 /* logevent, only printf-formatted. */
760 static void logeventf(Ssh ssh, const char *fmt, ...)
766 buf = dupvprintf(fmt, ap);
772 #define bombout(msg) \
774 char *text = dupprintf msg; \
777 connection_fatal(ssh->frontend, "%s", text); \
781 /* Functions to leave bits out of the SSH packet log file. */
783 static void dont_log_password(Ssh ssh, struct Packet *pkt, int blanktype)
785 if (ssh->cfg.logomitpass)
786 pkt->logmode = blanktype;
789 static void dont_log_data(Ssh ssh, struct Packet *pkt, int blanktype)
791 if (ssh->cfg.logomitdata)
792 pkt->logmode = blanktype;
795 static void end_log_omission(Ssh ssh, struct Packet *pkt)
797 pkt->logmode = PKTLOG_EMIT;
800 static int ssh_channelcmp(void *av, void *bv)
802 struct ssh_channel *a = (struct ssh_channel *) av;
803 struct ssh_channel *b = (struct ssh_channel *) bv;
804 if (a->localid < b->localid)
806 if (a->localid > b->localid)
810 static int ssh_channelfind(void *av, void *bv)
812 unsigned *a = (unsigned *) av;
813 struct ssh_channel *b = (struct ssh_channel *) bv;
821 static int ssh_rportcmp_ssh1(void *av, void *bv)
823 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
824 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
826 if ( (i = strcmp(a->dhost, b->dhost)) != 0)
827 return i < 0 ? -1 : +1;
828 if (a->dport > b->dport)
830 if (a->dport < b->dport)
835 static int ssh_rportcmp_ssh2(void *av, void *bv)
837 struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
838 struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
840 if (a->sport > b->sport)
842 if (a->sport < b->sport)
848 * Special form of strcmp which can cope with NULL inputs. NULL is
849 * defined to sort before even the empty string.
851 static int nullstrcmp(const char *a, const char *b)
853 if (a == NULL && b == NULL)
862 static int ssh_portcmp(void *av, void *bv)
864 struct ssh_portfwd *a = (struct ssh_portfwd *) av;
865 struct ssh_portfwd *b = (struct ssh_portfwd *) bv;
867 if (a->type > b->type)
869 if (a->type < b->type)
871 if (a->addressfamily > b->addressfamily)
873 if (a->addressfamily < b->addressfamily)
875 if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
876 return i < 0 ? -1 : +1;
877 if (a->sport > b->sport)
879 if (a->sport < b->sport)
881 if (a->type != 'D') {
882 if ( (i = nullstrcmp(a->daddr, b->daddr)) != 0)
883 return i < 0 ? -1 : +1;
884 if (a->dport > b->dport)
886 if (a->dport < b->dport)
892 static int alloc_channel_id(Ssh ssh)
894 const unsigned CHANNEL_NUMBER_OFFSET = 256;
895 unsigned low, high, mid;
897 struct ssh_channel *c;
900 * First-fit allocation of channel numbers: always pick the
901 * lowest unused one. To do this, binary-search using the
902 * counted B-tree to find the largest channel ID which is in a
903 * contiguous sequence from the beginning. (Precisely
904 * everything in that sequence must have ID equal to its tree
905 * index plus CHANNEL_NUMBER_OFFSET.)
907 tsize = count234(ssh->channels);
911 while (high - low > 1) {
912 mid = (high + low) / 2;
913 c = index234(ssh->channels, mid);
914 if (c->localid == mid + CHANNEL_NUMBER_OFFSET)
915 low = mid; /* this one is fine */
917 high = mid; /* this one is past it */
920 * Now low points to either -1, or the tree index of the
921 * largest ID in the initial sequence.
924 unsigned i = low + 1 + CHANNEL_NUMBER_OFFSET;
925 assert(NULL == find234(ssh->channels, &i, ssh_channelfind));
927 return low + 1 + CHANNEL_NUMBER_OFFSET;
930 static void c_write(Ssh ssh, const char *buf, int len)
932 if ((flags & FLAG_STDERR)) {
934 for (i = 0; i < len; i++)
936 fputc(buf[i], stderr);
939 from_backend(ssh->frontend, 1, buf, len);
942 static void c_write_untrusted(Ssh ssh, const char *buf, int len)
945 for (i = 0; i < len; i++) {
947 c_write(ssh, "\r\n", 2);
948 else if ((buf[i] & 0x60) || (buf[i] == '\r'))
949 c_write(ssh, buf + i, 1);
953 static void c_write_str(Ssh ssh, const char *buf)
955 c_write(ssh, buf, strlen(buf));
958 static void ssh_free_packet(struct Packet *pkt)
963 static struct Packet *ssh_new_packet(void)
965 struct Packet *pkt = snew(struct Packet);
969 pkt->logmode = PKTLOG_EMIT;
977 * Collect incoming data in the incoming packet buffer.
978 * Decipher and verify the packet when it is completely read.
979 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
980 * Update the *data and *datalen variables.
981 * Return a Packet structure when a packet is completed.
983 static struct Packet *ssh1_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
985 struct rdpkt1_state_tag *st = &ssh->rdpkt1_state;
987 crBegin(ssh->ssh1_rdpkt_crstate);
989 st->pktin = ssh_new_packet();
992 st->pktin->length = 0;
994 for (st->i = st->len = 0; st->i < 4; st->i++) {
995 while ((*datalen) == 0)
997 st->len = (st->len << 8) + **data;
998 (*data)++, (*datalen)--;
1001 st->pad = 8 - (st->len % 8);
1002 st->biglen = st->len + st->pad;
1003 st->pktin->length = st->len - 5;
1005 if (st->biglen < 0) {
1006 bombout(("Extremely large packet length from server suggests"
1007 " data stream corruption"));
1008 ssh_free_packet(st->pktin);
1012 st->pktin->maxlen = st->biglen;
1013 st->pktin->data = snewn(st->biglen + APIEXTRA, unsigned char);
1015 st->to_read = st->biglen;
1016 st->p = st->pktin->data;
1017 while (st->to_read > 0) {
1018 st->chunk = st->to_read;
1019 while ((*datalen) == 0)
1021 if (st->chunk > (*datalen))
1022 st->chunk = (*datalen);
1023 memcpy(st->p, *data, st->chunk);
1025 *datalen -= st->chunk;
1027 st->to_read -= st->chunk;
1030 if (ssh->cipher && detect_attack(ssh->crcda_ctx, st->pktin->data,
1031 st->biglen, NULL)) {
1032 bombout(("Network attack (CRC compensation) detected!"));
1033 ssh_free_packet(st->pktin);
1038 ssh->cipher->decrypt(ssh->v1_cipher_ctx, st->pktin->data, st->biglen);
1040 st->realcrc = crc32_compute(st->pktin->data, st->biglen - 4);
1041 st->gotcrc = GET_32BIT(st->pktin->data + st->biglen - 4);
1042 if (st->gotcrc != st->realcrc) {
1043 bombout(("Incorrect CRC received on packet"));
1044 ssh_free_packet(st->pktin);
1048 st->pktin->body = st->pktin->data + st->pad + 1;
1049 st->pktin->savedpos = 0;
1051 if (ssh->v1_compressing) {
1052 unsigned char *decompblk;
1054 if (!zlib_decompress_block(ssh->sc_comp_ctx,
1055 st->pktin->body - 1, st->pktin->length + 1,
1056 &decompblk, &decomplen)) {
1057 bombout(("Zlib decompression encountered invalid data"));
1058 ssh_free_packet(st->pktin);
1062 if (st->pktin->maxlen < st->pad + decomplen) {
1063 st->pktin->maxlen = st->pad + decomplen;
1064 st->pktin->data = sresize(st->pktin->data,
1065 st->pktin->maxlen + APIEXTRA,
1067 st->pktin->body = st->pktin->data + st->pad + 1;
1070 memcpy(st->pktin->body - 1, decompblk, decomplen);
1072 st->pktin->length = decomplen - 1;
1075 st->pktin->type = st->pktin->body[-1];
1078 * Log incoming packet, possibly omitting sensitive fields.
1082 struct logblank_t blank;
1083 if (ssh->cfg.logomitdata) {
1084 int do_blank = FALSE, blank_prefix = 0;
1085 /* "Session data" packets - omit the data field */
1086 if ((st->pktin->type == SSH1_SMSG_STDOUT_DATA) ||
1087 (st->pktin->type == SSH1_SMSG_STDERR_DATA)) {
1088 do_blank = TRUE; blank_prefix = 0;
1089 } else if (st->pktin->type == SSH1_MSG_CHANNEL_DATA) {
1090 do_blank = TRUE; blank_prefix = 4;
1093 blank.offset = blank_prefix;
1094 blank.len = st->pktin->length;
1095 blank.type = PKTLOG_OMIT;
1099 log_packet(ssh->logctx,
1100 PKT_INCOMING, st->pktin->type,
1101 ssh1_pkt_type(st->pktin->type),
1102 st->pktin->body, st->pktin->length,
1106 crFinish(st->pktin);
1109 static struct Packet *ssh2_rdpkt(Ssh ssh, unsigned char **data, int *datalen)
1111 struct rdpkt2_state_tag *st = &ssh->rdpkt2_state;
1113 crBegin(ssh->ssh2_rdpkt_crstate);
1115 st->pktin = ssh_new_packet();
1117 st->pktin->type = 0;
1118 st->pktin->length = 0;
1120 st->cipherblk = ssh->sccipher->blksize;
1123 if (st->cipherblk < 8)
1126 st->pktin->data = snewn(st->cipherblk + APIEXTRA, unsigned char);
1129 * Acquire and decrypt the first block of the packet. This will
1130 * contain the length and padding details.
1132 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
1133 while ((*datalen) == 0)
1135 st->pktin->data[st->i] = *(*data)++;
1140 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1141 st->pktin->data, st->cipherblk);
1144 * Now get the length and padding figures.
1146 st->len = GET_32BIT(st->pktin->data);
1147 st->pad = st->pktin->data[4];
1150 * _Completely_ silly lengths should be stomped on before they
1151 * do us any more damage.
1153 if (st->len < 0 || st->pad < 0 || st->len + st->pad < 0) {
1154 bombout(("Incoming packet was garbled on decryption"));
1155 ssh_free_packet(st->pktin);
1160 * This enables us to deduce the payload length.
1162 st->payload = st->len - st->pad - 1;
1164 st->pktin->length = st->payload + 5;
1167 * So now we can work out the total packet length.
1169 st->packetlen = st->len + 4;
1170 st->maclen = ssh->scmac ? ssh->scmac->len : 0;
1173 * Allocate memory for the rest of the packet.
1175 st->pktin->maxlen = st->packetlen + st->maclen;
1176 st->pktin->data = sresize(st->pktin->data,
1177 st->pktin->maxlen + APIEXTRA,
1181 * Read and decrypt the remainder of the packet.
1183 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen;
1185 while ((*datalen) == 0)
1187 st->pktin->data[st->i] = *(*data)++;
1190 /* Decrypt everything _except_ the MAC. */
1192 ssh->sccipher->decrypt(ssh->sc_cipher_ctx,
1193 st->pktin->data + st->cipherblk,
1194 st->packetlen - st->cipherblk);
1196 st->pktin->encrypted_len = st->packetlen;
1202 && !ssh->scmac->verify(ssh->sc_mac_ctx, st->pktin->data, st->len + 4,
1203 st->incoming_sequence)) {
1204 bombout(("Incorrect MAC received on packet"));
1205 ssh_free_packet(st->pktin);
1209 st->pktin->sequence = st->incoming_sequence++;
1212 * Decompress packet payload.
1215 unsigned char *newpayload;
1218 ssh->sccomp->decompress(ssh->sc_comp_ctx,
1219 st->pktin->data + 5, st->pktin->length - 5,
1220 &newpayload, &newlen)) {
1221 if (st->pktin->maxlen < newlen + 5) {
1222 st->pktin->maxlen = newlen + 5;
1223 st->pktin->data = sresize(st->pktin->data,
1224 st->pktin->maxlen + APIEXTRA,
1227 st->pktin->length = 5 + newlen;
1228 memcpy(st->pktin->data + 5, newpayload, newlen);
1233 st->pktin->savedpos = 6;
1234 st->pktin->body = st->pktin->data;
1235 st->pktin->type = st->pktin->data[5];
1238 * Log incoming packet, possibly omitting sensitive fields.
1242 struct logblank_t blank;
1243 if (ssh->cfg.logomitdata) {
1244 int do_blank = FALSE, blank_prefix = 0;
1245 /* "Session data" packets - omit the data field */
1246 if (st->pktin->type == SSH2_MSG_CHANNEL_DATA) {
1247 do_blank = TRUE; blank_prefix = 4;
1248 } else if (st->pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
1249 do_blank = TRUE; blank_prefix = 8;
1252 blank.offset = blank_prefix;
1253 blank.len = (st->pktin->length-6) - blank_prefix;
1254 blank.type = PKTLOG_OMIT;
1258 log_packet(ssh->logctx, PKT_INCOMING, st->pktin->type,
1259 ssh2_pkt_type(ssh->pkt_ctx, st->pktin->type),
1260 st->pktin->data+6, st->pktin->length-6,
1264 crFinish(st->pktin);
1267 static void ssh1_pktout_size(struct Packet *pkt, int len)
1271 len += 5; /* type and CRC */
1272 pad = 8 - (len % 8);
1275 pkt->length = len - 5;
1276 if (pkt->maxlen < biglen) {
1277 pkt->maxlen = biglen;
1278 pkt->data = sresize(pkt->data, biglen + 4 + APIEXTRA, unsigned char);
1280 pkt->body = pkt->data + 4 + pad + 1;
1283 static struct Packet *s_wrpkt_start(int type, int len)
1285 struct Packet *pkt = ssh_new_packet();
1286 ssh1_pktout_size(pkt, len);
1288 /* Initialise log omission state */
1294 static int s_wrpkt_prepare(Ssh ssh, struct Packet *pkt)
1300 * XXX various versions of SC (including 8.8.4) screw up the
1301 * register allocation in this function and use the same register
1302 * (D6) for len and as a temporary, with predictable results. The
1303 * following sledgehammer prevents this.
1309 pkt->body[-1] = pkt->type;
1312 log_packet(ssh->logctx, PKT_OUTGOING, pkt->type,
1313 ssh1_pkt_type(pkt->type),
1314 pkt->body, pkt->length,
1315 pkt->nblanks, pkt->blanks);
1316 sfree(pkt->blanks); pkt->blanks = NULL;
1319 if (ssh->v1_compressing) {
1320 unsigned char *compblk;
1322 zlib_compress_block(ssh->cs_comp_ctx,
1323 pkt->body - 1, pkt->length + 1,
1324 &compblk, &complen);
1325 ssh1_pktout_size(pkt, complen - 1);
1326 memcpy(pkt->body - 1, compblk, complen);
1330 len = pkt->length + 5; /* type and CRC */
1331 pad = 8 - (len % 8);
1334 for (i = 0; i < pad; i++)
1335 pkt->data[i + 4] = random_byte();
1336 crc = crc32_compute(pkt->data + 4, biglen - 4);
1337 PUT_32BIT(pkt->data + biglen, crc);
1338 PUT_32BIT(pkt->data, len);
1341 ssh->cipher->encrypt(ssh->v1_cipher_ctx, pkt->data + 4, biglen);
1346 static void s_wrpkt(Ssh ssh, struct Packet *pkt)
1349 len = s_wrpkt_prepare(ssh, pkt);
1350 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1351 if (backlog > SSH_MAX_BACKLOG)
1352 ssh_throttle_all(ssh, 1, backlog);
1355 static void s_wrpkt_defer(Ssh ssh, struct Packet *pkt)
1358 len = s_wrpkt_prepare(ssh, pkt);
1359 if (ssh->deferred_len + len > ssh->deferred_size) {
1360 ssh->deferred_size = ssh->deferred_len + len + 128;
1361 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1365 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1366 ssh->deferred_len += len;
1370 * Construct a packet with the specified contents.
1372 static struct Packet *construct_packet(Ssh ssh, int pkttype,
1373 va_list ap1, va_list ap2)
1375 unsigned char *p, *argp, argchar;
1376 unsigned long argint;
1377 int pktlen, argtype, arglen;
1382 while ((argtype = va_arg(ap1, int)) != PKT_END) {
1385 (void) va_arg(ap1, int);
1389 (void) va_arg(ap1, int);
1393 (void) va_arg(ap1, unsigned char *);
1394 arglen = va_arg(ap1, int);
1398 argp = va_arg(ap1, unsigned char *);
1399 arglen = strlen((char *)argp);
1400 pktlen += 4 + arglen;
1403 bn = va_arg(ap1, Bignum);
1404 pktlen += ssh1_bignum_length(bn);
1409 /* ignore this pass */
1416 pkt = s_wrpkt_start(pkttype, pktlen);
1419 while ((argtype = va_arg(ap2, int)) != PKT_END) {
1420 int offset = p - pkt->body, len = 0;
1422 /* Actual fields in the packet */
1424 argint = va_arg(ap2, int);
1425 PUT_32BIT(p, argint);
1429 argchar = (unsigned char) va_arg(ap2, int);
1434 argp = va_arg(ap2, unsigned char *);
1435 arglen = va_arg(ap2, int);
1436 memcpy(p, argp, arglen);
1440 argp = va_arg(ap2, unsigned char *);
1441 arglen = strlen((char *)argp);
1442 PUT_32BIT(p, arglen);
1443 memcpy(p + 4, argp, arglen);
1447 bn = va_arg(ap2, Bignum);
1448 len = ssh1_write_bignum(p, bn);
1450 /* Tokens for modifications to packet logging */
1452 dont_log_password(ssh, pkt, PKTLOG_BLANK);
1455 dont_log_data(ssh, pkt, PKTLOG_OMIT);
1458 end_log_omission(ssh, pkt);
1462 /* Deal with logfile omission, if required. */
1463 if (len && (pkt->logmode != PKTLOG_EMIT)) {
1465 pkt->blanks = sresize(pkt->blanks, pkt->nblanks,
1467 pkt->blanks[pkt->nblanks-1].offset = offset;
1468 pkt->blanks[pkt->nblanks-1].len = len;
1469 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1476 static void send_packet(Ssh ssh, int pkttype, ...)
1480 va_start(ap1, pkttype);
1481 va_start(ap2, pkttype);
1482 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1486 ssh_free_packet(pkt);
1489 static void defer_packet(Ssh ssh, int pkttype, ...)
1493 va_start(ap1, pkttype);
1494 va_start(ap2, pkttype);
1495 pkt = construct_packet(ssh, pkttype, ap1, ap2);
1498 s_wrpkt_defer(ssh, pkt);
1499 ssh_free_packet(pkt);
1502 static int ssh_versioncmp(char *a, char *b)
1505 unsigned long av, bv;
1507 av = strtoul(a, &ae, 10);
1508 bv = strtoul(b, &be, 10);
1510 return (av < bv ? -1 : +1);
1515 av = strtoul(ae, &ae, 10);
1516 bv = strtoul(be, &be, 10);
1518 return (av < bv ? -1 : +1);
1523 * Utility routines for putting an SSH-protocol `string' and
1524 * `uint32' into a SHA state.
1527 static void sha_string(SHA_State * s, void *str, int len)
1529 unsigned char lenblk[4];
1530 PUT_32BIT(lenblk, len);
1531 SHA_Bytes(s, lenblk, 4);
1532 SHA_Bytes(s, str, len);
1535 static void sha_uint32(SHA_State * s, unsigned i)
1537 unsigned char intblk[4];
1538 PUT_32BIT(intblk, i);
1539 SHA_Bytes(s, intblk, 4);
1543 * SSH2 packet construction functions.
1545 static void ssh2_pkt_ensure(struct Packet *pkt, int length)
1547 if (pkt->maxlen < length) {
1548 pkt->maxlen = length + 256;
1549 pkt->data = sresize(pkt->data, pkt->maxlen + APIEXTRA, unsigned char);
1552 static void ssh2_pkt_adddata(struct Packet *pkt, void *data, int len)
1554 if (pkt->logmode != PKTLOG_EMIT) {
1556 pkt->blanks = sresize(pkt->blanks, pkt->nblanks, struct logblank_t);
1557 pkt->blanks[pkt->nblanks-1].offset = pkt->length - 6;
1558 pkt->blanks[pkt->nblanks-1].len = len;
1559 pkt->blanks[pkt->nblanks-1].type = pkt->logmode;
1562 ssh2_pkt_ensure(pkt, pkt->length);
1563 memcpy(pkt->data + pkt->length - len, data, len);
1565 static void ssh2_pkt_addbyte(struct Packet *pkt, unsigned char byte)
1567 ssh2_pkt_adddata(pkt, &byte, 1);
1569 static struct Packet *ssh2_pkt_init(int pkt_type)
1571 struct Packet *pkt = ssh_new_packet();
1573 ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
1576 static void ssh2_pkt_addbool(struct Packet *pkt, unsigned char value)
1578 ssh2_pkt_adddata(pkt, &value, 1);
1580 static void ssh2_pkt_adduint32(struct Packet *pkt, unsigned long value)
1583 PUT_32BIT(x, value);
1584 ssh2_pkt_adddata(pkt, x, 4);
1586 static void ssh2_pkt_addstring_start(struct Packet *pkt)
1588 ssh2_pkt_adduint32(pkt, 0);
1589 pkt->savedpos = pkt->length;
1591 static void ssh2_pkt_addstring_str(struct Packet *pkt, char *data)
1593 ssh2_pkt_adddata(pkt, data, strlen(data));
1594 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1596 static void ssh2_pkt_addstring_data(struct Packet *pkt, char *data, int len)
1598 ssh2_pkt_adddata(pkt, data, len);
1599 PUT_32BIT(pkt->data + pkt->savedpos - 4, pkt->length - pkt->savedpos);
1601 static void ssh2_pkt_addstring(struct Packet *pkt, char *data)
1603 ssh2_pkt_addstring_start(pkt);
1604 ssh2_pkt_addstring_str(pkt, data);
1606 static unsigned char *ssh2_mpint_fmt(Bignum b, int *len)
1609 int i, n = (bignum_bitcount(b) + 7) / 8;
1610 p = snewn(n + 1, unsigned char);
1612 fatalbox("out of memory");
1614 for (i = 1; i <= n; i++)
1615 p[i] = bignum_byte(b, n - i);
1617 while (i <= n && p[i] == 0 && (p[i + 1] & 0x80) == 0)
1619 memmove(p, p + i, n + 1 - i);
1623 static void ssh2_pkt_addmp(struct Packet *pkt, Bignum b)
1627 p = ssh2_mpint_fmt(b, &len);
1628 ssh2_pkt_addstring_start(pkt);
1629 ssh2_pkt_addstring_data(pkt, (char *)p, len);
1634 * Construct an SSH2 final-form packet: compress it, encrypt it,
1635 * put the MAC on it. Final packet, ready to be sent, is stored in
1636 * pkt->data. Total length is returned.
1638 static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
1640 int cipherblk, maclen, padding, i;
1643 log_packet(ssh->logctx, PKT_OUTGOING, pkt->data[5],
1644 ssh2_pkt_type(ssh->pkt_ctx, pkt->data[5]),
1645 pkt->data + 6, pkt->length - 6,
1646 pkt->nblanks, pkt->blanks);
1647 sfree(pkt->blanks); pkt->blanks = NULL;
1651 * Compress packet payload.
1654 unsigned char *newpayload;
1657 ssh->cscomp->compress(ssh->cs_comp_ctx, pkt->data + 5,
1659 &newpayload, &newlen)) {
1661 ssh2_pkt_adddata(pkt, newpayload, newlen);
1667 * Add padding. At least four bytes, and must also bring total
1668 * length (minus MAC) up to a multiple of the block size.
1670 cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8; /* block size */
1671 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
1674 (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
1675 maclen = ssh->csmac ? ssh->csmac->len : 0;
1676 ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
1677 pkt->data[4] = padding;
1678 for (i = 0; i < padding; i++)
1679 pkt->data[pkt->length + i] = random_byte();
1680 PUT_32BIT(pkt->data, pkt->length + padding - 4);
1682 ssh->csmac->generate(ssh->cs_mac_ctx, pkt->data,
1683 pkt->length + padding,
1684 ssh->v2_outgoing_sequence);
1685 ssh->v2_outgoing_sequence++; /* whether or not we MACed */
1688 ssh->cscipher->encrypt(ssh->cs_cipher_ctx,
1689 pkt->data, pkt->length + padding);
1691 pkt->encrypted_len = pkt->length + padding;
1693 /* Ready-to-send packet starts at pkt->data. We return length. */
1694 return pkt->length + padding + maclen;
1698 * Routines called from the main SSH code to send packets. There
1699 * are quite a few of these, because we have two separate
1700 * mechanisms for delaying the sending of packets:
1702 * - In order to send an IGNORE message and a password message in
1703 * a single fixed-length blob, we require the ability to
1704 * concatenate the encrypted forms of those two packets _into_ a
1705 * single blob and then pass it to our <network.h> transport
1706 * layer in one go. Hence, there's a deferment mechanism which
1707 * works after packet encryption.
1709 * - In order to avoid sending any connection-layer messages
1710 * during repeat key exchange, we have to queue up any such
1711 * outgoing messages _before_ they are encrypted (and in
1712 * particular before they're allocated sequence numbers), and
1713 * then send them once we've finished.
1715 * I call these mechanisms `defer' and `queue' respectively, so as
1716 * to distinguish them reasonably easily.
1718 * The functions send_noqueue() and defer_noqueue() free the packet
1719 * structure they are passed. Every outgoing packet goes through
1720 * precisely one of these functions in its life; packets passed to
1721 * ssh2_pkt_send() or ssh2_pkt_defer() either go straight to one of
1722 * these or get queued, and then when the queue is later emptied
1723 * the packets are all passed to defer_noqueue().
1727 * Send an SSH2 packet immediately, without queuing or deferring.
1729 static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
1733 len = ssh2_pkt_construct(ssh, pkt);
1734 backlog = sk_write(ssh->s, (char *)pkt->data, len);
1735 if (backlog > SSH_MAX_BACKLOG)
1736 ssh_throttle_all(ssh, 1, backlog);
1738 ssh->outgoing_data_size += pkt->encrypted_len;
1739 if (!ssh->kex_in_progress &&
1740 ssh->max_data_size != 0 &&
1741 ssh->outgoing_data_size > ssh->max_data_size)
1742 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1744 ssh_free_packet(pkt);
1748 * Defer an SSH2 packet.
1750 static void ssh2_pkt_defer_noqueue(Ssh ssh, struct Packet *pkt)
1752 int len = ssh2_pkt_construct(ssh, pkt);
1753 if (ssh->deferred_len + len > ssh->deferred_size) {
1754 ssh->deferred_size = ssh->deferred_len + len + 128;
1755 ssh->deferred_send_data = sresize(ssh->deferred_send_data,
1759 memcpy(ssh->deferred_send_data + ssh->deferred_len, pkt->data, len);
1760 ssh->deferred_len += len;
1761 ssh->deferred_data_size += pkt->encrypted_len;
1762 ssh_free_packet(pkt);
1766 * Queue an SSH2 packet.
1768 static void ssh2_pkt_queue(Ssh ssh, struct Packet *pkt)
1770 assert(ssh->queueing);
1772 if (ssh->queuelen >= ssh->queuesize) {
1773 ssh->queuesize = ssh->queuelen + 32;
1774 ssh->queue = sresize(ssh->queue, ssh->queuesize, struct Packet *);
1777 ssh->queue[ssh->queuelen++] = pkt;
1781 * Either queue or send a packet, depending on whether queueing is
1784 static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
1787 ssh2_pkt_queue(ssh, pkt);
1789 ssh2_pkt_send_noqueue(ssh, pkt);
1793 * Either queue or defer a packet, depending on whether queueing is
1796 static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
1799 ssh2_pkt_queue(ssh, pkt);
1801 ssh2_pkt_defer_noqueue(ssh, pkt);
1805 * Send the whole deferred data block constructed by
1806 * ssh2_pkt_defer() or SSH1's defer_packet().
1808 * The expected use of the defer mechanism is that you call
1809 * ssh2_pkt_defer() a few times, then call ssh_pkt_defersend(). If
1810 * not currently queueing, this simply sets up deferred_send_data
1811 * and then sends it. If we _are_ currently queueing, the calls to
1812 * ssh2_pkt_defer() put the deferred packets on to the queue
1813 * instead, and therefore ssh_pkt_defersend() has no deferred data
1814 * to send. Hence, there's no need to make it conditional on
1817 static void ssh_pkt_defersend(Ssh ssh)
1820 backlog = sk_write(ssh->s, (char *)ssh->deferred_send_data,
1822 ssh->deferred_len = ssh->deferred_size = 0;
1823 sfree(ssh->deferred_send_data);
1824 ssh->deferred_send_data = NULL;
1825 if (backlog > SSH_MAX_BACKLOG)
1826 ssh_throttle_all(ssh, 1, backlog);
1828 ssh->outgoing_data_size += ssh->deferred_data_size;
1829 if (!ssh->kex_in_progress &&
1830 ssh->max_data_size != 0 &&
1831 ssh->outgoing_data_size > ssh->max_data_size)
1832 do_ssh2_transport(ssh, "too much data sent", -1, NULL);
1833 ssh->deferred_data_size = 0;
1837 * Send all queued SSH2 packets. We send them by means of
1838 * ssh2_pkt_defer_noqueue(), in case they included a pair of
1839 * packets that needed to be lumped together.
1841 static void ssh2_pkt_queuesend(Ssh ssh)
1845 assert(!ssh->queueing);
1847 for (i = 0; i < ssh->queuelen; i++)
1848 ssh2_pkt_defer_noqueue(ssh, ssh->queue[i]);
1851 ssh_pkt_defersend(ssh);
1855 void bndebug(char *string, Bignum b)
1859 p = ssh2_mpint_fmt(b, &len);
1860 debug(("%s", string));
1861 for (i = 0; i < len; i++)
1862 debug((" %02x", p[i]));
1868 static void sha_mpint(SHA_State * s, Bignum b)
1872 p = ssh2_mpint_fmt(b, &len);
1873 sha_string(s, p, len);
1878 * Packet decode functions for both SSH1 and SSH2.
1880 static unsigned long ssh_pkt_getuint32(struct Packet *pkt)
1882 unsigned long value;
1883 if (pkt->length - pkt->savedpos < 4)
1884 return 0; /* arrgh, no way to decline (FIXME?) */
1885 value = GET_32BIT(pkt->body + pkt->savedpos);
1889 static int ssh2_pkt_getbool(struct Packet *pkt)
1891 unsigned long value;
1892 if (pkt->length - pkt->savedpos < 1)
1893 return 0; /* arrgh, no way to decline (FIXME?) */
1894 value = pkt->body[pkt->savedpos] != 0;
1898 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length)
1903 if (pkt->length - pkt->savedpos < 4)
1905 len = GET_32BIT(pkt->body + pkt->savedpos);
1910 if (pkt->length - pkt->savedpos < *length)
1912 *p = (char *)(pkt->body + pkt->savedpos);
1913 pkt->savedpos += *length;
1915 static void *ssh_pkt_getdata(struct Packet *pkt, int length)
1917 if (pkt->length - pkt->savedpos < length)
1919 pkt->savedpos += length;
1920 return pkt->body + (pkt->savedpos - length);
1922 static int ssh1_pkt_getrsakey(struct Packet *pkt, struct RSAKey *key,
1923 unsigned char **keystr)
1927 j = makekey(pkt->body + pkt->savedpos,
1928 pkt->length - pkt->savedpos,
1935 assert(pkt->savedpos < pkt->length);
1939 static Bignum ssh1_pkt_getmp(struct Packet *pkt)
1944 j = ssh1_read_bignum(pkt->body + pkt->savedpos,
1945 pkt->length - pkt->savedpos, &b);
1953 static Bignum ssh2_pkt_getmp(struct Packet *pkt)
1959 ssh_pkt_getstring(pkt, &p, &length);
1964 b = bignum_from_bytes((unsigned char *)p, length);
1969 * Helper function to add an SSH2 signature blob to a packet.
1970 * Expects to be shown the public key blob as well as the signature
1971 * blob. Normally works just like ssh2_pkt_addstring, but will
1972 * fiddle with the signature packet if necessary for
1973 * BUG_SSH2_RSA_PADDING.
1975 static void ssh2_add_sigblob(Ssh ssh, struct Packet *pkt,
1976 void *pkblob_v, int pkblob_len,
1977 void *sigblob_v, int sigblob_len)
1979 unsigned char *pkblob = (unsigned char *)pkblob_v;
1980 unsigned char *sigblob = (unsigned char *)sigblob_v;
1982 /* dmemdump(pkblob, pkblob_len); */
1983 /* dmemdump(sigblob, sigblob_len); */
1986 * See if this is in fact an ssh-rsa signature and a buggy
1987 * server; otherwise we can just do this the easy way.
1989 if ((ssh->remote_bugs & BUG_SSH2_RSA_PADDING) &&
1990 (GET_32BIT(pkblob) == 7 && !memcmp(pkblob+4, "ssh-rsa", 7))) {
1991 int pos, len, siglen;
1994 * Find the byte length of the modulus.
1997 pos = 4+7; /* skip over "ssh-rsa" */
1998 pos += 4 + GET_32BIT(pkblob+pos); /* skip over exponent */
1999 len = GET_32BIT(pkblob+pos); /* find length of modulus */
2000 pos += 4; /* find modulus itself */
2001 while (len > 0 && pkblob[pos] == 0)
2003 /* debug(("modulus length is %d\n", len)); */
2006 * Now find the signature integer.
2008 pos = 4+7; /* skip over "ssh-rsa" */
2009 siglen = GET_32BIT(sigblob+pos);
2010 /* debug(("signature length is %d\n", siglen)); */
2012 if (len != siglen) {
2013 unsigned char newlen[4];
2014 ssh2_pkt_addstring_start(pkt);
2015 ssh2_pkt_addstring_data(pkt, (char *)sigblob, pos);
2016 /* dmemdump(sigblob, pos); */
2017 pos += 4; /* point to start of actual sig */
2018 PUT_32BIT(newlen, len);
2019 ssh2_pkt_addstring_data(pkt, (char *)newlen, 4);
2020 /* dmemdump(newlen, 4); */
2022 while (len-- > siglen) {
2023 ssh2_pkt_addstring_data(pkt, (char *)newlen, 1);
2024 /* dmemdump(newlen, 1); */
2026 ssh2_pkt_addstring_data(pkt, (char *)(sigblob+pos), siglen);
2027 /* dmemdump(sigblob+pos, siglen); */
2031 /* Otherwise fall through and do it the easy way. */
2034 ssh2_pkt_addstring_start(pkt);
2035 ssh2_pkt_addstring_data(pkt, (char *)sigblob, sigblob_len);
2039 * Examine the remote side's version string and compare it against
2040 * a list of known buggy implementations.
2042 static void ssh_detect_bugs(Ssh ssh, char *vstring)
2044 char *imp; /* pointer to implementation part */
2046 imp += strcspn(imp, "-");
2048 imp += strcspn(imp, "-");
2051 ssh->remote_bugs = 0;
2053 if (ssh->cfg.sshbug_ignore1 == FORCE_ON ||
2054 (ssh->cfg.sshbug_ignore1 == AUTO &&
2055 (!strcmp(imp, "1.2.18") || !strcmp(imp, "1.2.19") ||
2056 !strcmp(imp, "1.2.20") || !strcmp(imp, "1.2.21") ||
2057 !strcmp(imp, "1.2.22") || !strcmp(imp, "Cisco-1.25") ||
2058 !strcmp(imp, "OSU_1.4alpha3") || !strcmp(imp, "OSU_1.5alpha4")))) {
2060 * These versions don't support SSH1_MSG_IGNORE, so we have
2061 * to use a different defence against password length
2064 ssh->remote_bugs |= BUG_CHOKES_ON_SSH1_IGNORE;
2065 logevent("We believe remote version has SSH1 ignore bug");
2068 if (ssh->cfg.sshbug_plainpw1 == FORCE_ON ||
2069 (ssh->cfg.sshbug_plainpw1 == AUTO &&
2070 (!strcmp(imp, "Cisco-1.25") || !strcmp(imp, "OSU_1.4alpha3")))) {
2072 * These versions need a plain password sent; they can't
2073 * handle having a null and a random length of data after
2076 ssh->remote_bugs |= BUG_NEEDS_SSH1_PLAIN_PASSWORD;
2077 logevent("We believe remote version needs a plain SSH1 password");
2080 if (ssh->cfg.sshbug_rsa1 == FORCE_ON ||
2081 (ssh->cfg.sshbug_rsa1 == AUTO &&
2082 (!strcmp(imp, "Cisco-1.25")))) {
2084 * These versions apparently have no clue whatever about
2085 * RSA authentication and will panic and die if they see
2086 * an AUTH_RSA message.
2088 ssh->remote_bugs |= BUG_CHOKES_ON_RSA;
2089 logevent("We believe remote version can't handle RSA authentication");
2092 if (ssh->cfg.sshbug_hmac2 == FORCE_ON ||
2093 (ssh->cfg.sshbug_hmac2 == AUTO &&
2094 !wc_match("* VShell", imp) &&
2095 (wc_match("2.1.0*", imp) || wc_match("2.0.*", imp) ||
2096 wc_match("2.2.0*", imp) || wc_match("2.3.0*", imp) ||
2097 wc_match("2.1 *", imp)))) {
2099 * These versions have the HMAC bug.
2101 ssh->remote_bugs |= BUG_SSH2_HMAC;
2102 logevent("We believe remote version has SSH2 HMAC bug");
2105 if (ssh->cfg.sshbug_derivekey2 == FORCE_ON ||
2106 (ssh->cfg.sshbug_derivekey2 == AUTO &&
2107 !wc_match("* VShell", imp) &&
2108 (wc_match("2.0.0*", imp) || wc_match("2.0.10*", imp) ))) {
2110 * These versions have the key-derivation bug (failing to
2111 * include the literal shared secret in the hashes that
2112 * generate the keys).
2114 ssh->remote_bugs |= BUG_SSH2_DERIVEKEY;
2115 logevent("We believe remote version has SSH2 key-derivation bug");
2118 if (ssh->cfg.sshbug_rsapad2 == FORCE_ON ||
2119 (ssh->cfg.sshbug_rsapad2 == AUTO &&
2120 (wc_match("OpenSSH_2.[5-9]*", imp) ||
2121 wc_match("OpenSSH_3.[0-2]*", imp)))) {
2123 * These versions have the SSH2 RSA padding bug.
2125 ssh->remote_bugs |= BUG_SSH2_RSA_PADDING;
2126 logevent("We believe remote version has SSH2 RSA padding bug");
2129 if (ssh->cfg.sshbug_pksessid2 == FORCE_ON ||
2130 (ssh->cfg.sshbug_pksessid2 == AUTO &&
2131 wc_match("OpenSSH_2.[0-2]*", imp))) {
2133 * These versions have the SSH2 session-ID bug in
2134 * public-key authentication.
2136 ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
2137 logevent("We believe remote version has SSH2 public-key-session-ID bug");
2140 if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
2141 (ssh->cfg.sshbug_rekey2 == AUTO &&
2142 (wc_match("OpenSSH_2.[0-4]*", imp) ||
2143 wc_match("OpenSSH_2.5.[0-3]*", imp) ||
2144 wc_match("Sun_SSH_1.0", imp) ||
2145 wc_match("Sun_SSH_1.0.1", imp)))) {
2147 * These versions have the SSH2 rekey bug.
2149 ssh->remote_bugs |= BUG_SSH2_REKEY;
2150 logevent("We believe remote version has SSH2 rekey bug");
2155 * The `software version' part of an SSH version string is required
2156 * to contain no spaces or minus signs.
2158 static void ssh_fix_verstring(char *str)
2160 /* Eat "SSH-<protoversion>-". */
2161 assert(*str == 'S'); str++;
2162 assert(*str == 'S'); str++;
2163 assert(*str == 'H'); str++;
2164 assert(*str == '-'); str++;
2165 while (*str && *str != '-') str++;
2166 assert(*str == '-'); str++;
2168 /* Convert minus signs and spaces in the remaining string into
2171 if (*str == '-' || *str == ' ')
2177 static int do_ssh_init(Ssh ssh, unsigned char c)
2179 struct do_ssh_init_state {
2187 crState(do_ssh_init_state);
2189 crBegin(ssh->do_ssh_init_crstate);
2191 /* Search for the string "SSH-" in the input. */
2194 static const int transS[] = { 1, 2, 2, 1 };
2195 static const int transH[] = { 0, 0, 3, 0 };
2196 static const int transminus[] = { 0, 0, 0, -1 };
2198 s->i = transS[s->i];
2200 s->i = transH[s->i];
2202 s->i = transminus[s->i];
2207 crReturn(1); /* get another character */
2211 s->vstring = snewn(s->vstrsize, char);
2212 strcpy(s->vstring, "SSH-");
2216 crReturn(1); /* get another char */
2217 if (s->vslen >= s->vstrsize - 1) {
2219 s->vstring = sresize(s->vstring, s->vstrsize, char);
2221 s->vstring[s->vslen++] = c;
2224 s->version[s->i] = '\0';
2226 } else if (s->i < sizeof(s->version) - 1)
2227 s->version[s->i++] = c;
2228 } else if (c == '\012')
2232 ssh->agentfwd_enabled = FALSE;
2233 ssh->rdpkt2_state.incoming_sequence = 0;
2235 s->vstring[s->vslen] = 0;
2236 s->vstring[strcspn(s->vstring, "\015\012")] = '\0';/* remove EOL chars */
2239 vlog = snewn(20 + s->vslen, char);
2240 sprintf(vlog, "Server version: %s", s->vstring);
2244 ssh_detect_bugs(ssh, s->vstring);
2247 * Decide which SSH protocol version to support.
2250 /* Anything strictly below "2.0" means protocol 1 is supported. */
2251 s->proto1 = ssh_versioncmp(s->version, "2.0") < 0;
2252 /* Anything greater or equal to "1.99" means protocol 2 is supported. */
2253 s->proto2 = ssh_versioncmp(s->version, "1.99") >= 0;
2255 if (ssh->cfg.sshprot == 0 && !s->proto1) {
2256 bombout(("SSH protocol version 1 required by user but not provided by server"));
2259 if (ssh->cfg.sshprot == 3 && !s->proto2) {
2260 bombout(("SSH protocol version 2 required by user but not provided by server"));
2267 if (s->proto2 && (ssh->cfg.sshprot >= 2 || !s->proto1)) {
2269 * Construct a v2 version string.
2271 verstring = dupprintf("SSH-2.0-%s\015\012", sshver);
2275 * Construct a v1 version string.
2277 verstring = dupprintf("SSH-%s-%s\012",
2278 (ssh_versioncmp(s->version, "1.5") <= 0 ?
2279 s->version : "1.5"),
2284 ssh_fix_verstring(verstring);
2286 if (ssh->version == 2) {
2288 * Hash our version string and their version string.
2290 SHA_Init(&ssh->exhashbase);
2291 sha_string(&ssh->exhashbase, verstring,
2292 strcspn(verstring, "\015\012"));
2293 sha_string(&ssh->exhashbase, s->vstring,
2294 strcspn(s->vstring, "\015\012"));
2297 * Initialise SSHv2 protocol.
2299 ssh->protocol = ssh2_protocol;
2300 ssh2_protocol_setup(ssh);
2301 ssh->s_rdpkt = ssh2_rdpkt;
2304 * Initialise SSHv1 protocol.
2306 ssh->protocol = ssh1_protocol;
2307 ssh1_protocol_setup(ssh);
2308 ssh->s_rdpkt = ssh1_rdpkt;
2310 logeventf(ssh, "We claim version: %.*s",
2311 strcspn(verstring, "\015\012"), verstring);
2312 sk_write(ssh->s, verstring, strlen(verstring));
2316 logeventf(ssh, "Using SSH protocol version %d", ssh->version);
2318 update_specials_menu(ssh->frontend);
2319 ssh->state = SSH_STATE_BEFORE_SIZE;
2320 ssh->pinger = pinger_new(&ssh->cfg, &ssh_backend, ssh);
2327 static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
2329 crBegin(ssh->ssh_gotdata_crstate);
2332 * To begin with, feed the characters one by one to the
2333 * protocol initialisation / selection function do_ssh_init().
2334 * When that returns 0, we're done with the initial greeting
2335 * exchange and can move on to packet discipline.
2338 int ret; /* need not be kept across crReturn */
2340 crReturnV; /* more data please */
2341 ret = do_ssh_init(ssh, *data);
2349 * We emerge from that loop when the initial negotiation is
2350 * over and we have selected an s_rdpkt function. Now pass
2351 * everything to s_rdpkt, and then pass the resulting packets
2352 * to the proper protocol handler.
2357 while (datalen > 0) {
2358 struct Packet *pktin = ssh->s_rdpkt(ssh, &data, &datalen);
2360 ssh->protocol(ssh, NULL, 0, pktin);
2361 ssh_free_packet(pktin);
2363 if (ssh->state == SSH_STATE_CLOSED)
2371 static void ssh_do_close(Ssh ssh)
2374 struct ssh_channel *c;
2376 ssh->state = SSH_STATE_CLOSED;
2380 notify_remote_exit(ssh->frontend);
2383 * Now we must shut down any port and X forwardings going
2384 * through this connection.
2386 if (ssh->channels) {
2387 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2390 x11_close(c->u.x11.s);
2393 pfd_close(c->u.pfd.s);
2396 del234(ssh->channels, c);
2397 if (ssh->version == 2)
2398 bufchain_clear(&c->v.v2.outbuffer);
2404 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
2407 Ssh ssh = (Ssh) plug;
2410 /* A socket error has occurred. */
2411 logevent(error_msg);
2412 connection_fatal(ssh->frontend, "%s", error_msg);
2414 /* Otherwise, the remote side closed the connection normally. */
2419 static int ssh_receive(Plug plug, int urgent, char *data, int len)
2421 Ssh ssh = (Ssh) plug;
2422 ssh_gotdata(ssh, (unsigned char *)data, len);
2423 if (ssh->state == SSH_STATE_CLOSED) {
2430 static void ssh_sent(Plug plug, int bufsize)
2432 Ssh ssh = (Ssh) plug;
2434 * If the send backlog on the SSH socket itself clears, we
2435 * should unthrottle the whole world if it was throttled.
2437 if (bufsize < SSH_MAX_BACKLOG)
2438 ssh_throttle_all(ssh, 0, bufsize);
2442 * Connect to specified host and port.
2443 * Returns an error message, or NULL on success.
2444 * Also places the canonical host name into `realhost'. It must be
2445 * freed by the caller.
2447 static const char *connect_to_host(Ssh ssh, char *host, int port,
2448 char **realhost, int nodelay, int keepalive)
2450 static const struct plug_function_table fn_table = {
2460 ssh->savedhost = snewn(1 + strlen(host), char);
2461 if (!ssh->savedhost)
2462 fatalbox("Out of memory");
2463 strcpy(ssh->savedhost, host);
2466 port = 22; /* default ssh port */
2467 ssh->savedport = port;
2472 logeventf(ssh, "Looking up host \"%s\"%s", host,
2473 (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
2474 (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
2475 addr = name_lookup(host, port, realhost, &ssh->cfg,
2476 ssh->cfg.addressfamily);
2477 if ((err = sk_addr_error(addr)) != NULL) {
2487 sk_getaddr(addr, addrbuf, 100);
2488 logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
2490 ssh->fn = &fn_table;
2491 ssh->s = new_connection(addr, *realhost, port,
2492 0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
2493 if ((err = sk_socket_error(ssh->s)) != NULL) {
2495 notify_remote_exit(ssh->frontend);
2503 * Throttle or unthrottle the SSH connection.
2505 static void ssh1_throttle(Ssh ssh, int adjust)
2507 int old_count = ssh->v1_throttle_count;
2508 ssh->v1_throttle_count += adjust;
2509 assert(ssh->v1_throttle_count >= 0);
2510 if (ssh->v1_throttle_count && !old_count) {
2511 sk_set_frozen(ssh->s, 1);
2512 } else if (!ssh->v1_throttle_count && old_count) {
2513 sk_set_frozen(ssh->s, 0);
2518 * Throttle or unthrottle _all_ local data streams (for when sends
2519 * on the SSH connection itself back up).
2521 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize)
2524 struct ssh_channel *c;
2526 if (enable == ssh->throttled_all)
2528 ssh->throttled_all = enable;
2529 ssh->overall_bufsize = bufsize;
2532 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
2534 case CHAN_MAINSESSION:
2536 * This is treated separately, outside the switch.
2540 x11_override_throttle(c->u.x11.s, enable);
2543 /* Agent channels require no buffer management. */
2546 pfd_override_throttle(c->u.pfd.s, enable);
2553 * Username and password input, abstracted off into routines
2554 * reusable in several places - even between SSH1 and SSH2.
2557 /* Set up a username or password input loop on a given buffer. */
2558 static void setup_userpass_input(Ssh ssh, char *buffer, int buflen, int echo)
2560 ssh->userpass_input_buffer = buffer;
2561 ssh->userpass_input_buflen = buflen;
2562 ssh->userpass_input_bufpos = 0;
2563 ssh->userpass_input_echo = echo;
2567 * Process some terminal data in the course of username/password
2568 * input. Returns >0 for success (line of input returned in
2569 * buffer), <0 for failure (user hit ^C/^D, bomb out and exit), 0
2570 * for inconclusive (keep waiting for more input please).
2572 static int process_userpass_input(Ssh ssh, unsigned char *in, int inlen)
2577 switch (c = *in++) {
2580 ssh->userpass_input_buffer[ssh->userpass_input_bufpos] = 0;
2581 ssh->userpass_input_buffer[ssh->userpass_input_buflen-1] = 0;
2586 if (ssh->userpass_input_bufpos > 0) {
2587 if (ssh->userpass_input_echo)
2588 c_write_str(ssh, "\b \b");
2589 ssh->userpass_input_bufpos--;
2594 while (ssh->userpass_input_bufpos > 0) {
2595 if (ssh->userpass_input_echo)
2596 c_write_str(ssh, "\b \b");
2597 ssh->userpass_input_bufpos--;
2606 * This simplistic check for printability is disabled
2607 * when we're doing password input, because some people
2608 * have control characters in their passwords.o
2610 if ((!ssh->userpass_input_echo ||
2611 (c >= ' ' && c <= '~') ||
2612 ((unsigned char) c >= 160))
2613 && ssh->userpass_input_bufpos < ssh->userpass_input_buflen-1) {
2614 ssh->userpass_input_buffer[ssh->userpass_input_bufpos++] = c;
2615 if (ssh->userpass_input_echo)
2616 c_write(ssh, &c, 1);
2624 static void ssh_agent_callback(void *sshv, void *reply, int replylen)
2626 Ssh ssh = (Ssh) sshv;
2628 ssh->agent_response = reply;
2629 ssh->agent_response_len = replylen;
2631 if (ssh->version == 1)
2632 do_ssh1_login(ssh, NULL, -1, NULL);
2634 do_ssh2_authconn(ssh, NULL, -1, NULL);
2637 static void ssh_agentf_callback(void *cv, void *reply, int replylen)
2639 struct ssh_channel *c = (struct ssh_channel *)cv;
2641 void *sentreply = reply;
2644 /* Fake SSH_AGENT_FAILURE. */
2645 sentreply = "\0\0\0\1\5";
2648 if (ssh->version == 2) {
2649 ssh2_add_channel_data(c, sentreply, replylen);
2652 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
2653 PKT_INT, c->remoteid,
2656 PKT_DATA, sentreply, replylen,
2665 * Handle the key exchange and user authentication phases.
2667 static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
2668 struct Packet *pktin)
2671 unsigned char cookie[8], *ptr;
2672 struct RSAKey servkey, hostkey;
2673 struct MD5Context md5c;
2674 struct do_ssh1_login_state {
2676 unsigned char *rsabuf, *keystr1, *keystr2;
2677 unsigned long supported_ciphers_mask, supported_auths_mask;
2678 int tried_publickey, tried_agent;
2679 int tis_auth_refused, ccard_auth_refused;
2680 unsigned char session_id[16];
2683 void *publickey_blob;
2684 int publickey_bloblen;
2690 unsigned char request[5], *response, *p;
2699 crState(do_ssh1_login_state);
2701 crBegin(ssh->do_ssh1_login_crstate);
2706 if (pktin->type != SSH1_SMSG_PUBLIC_KEY) {
2707 bombout(("Public key packet not received"));
2711 logevent("Received public keys");
2713 ptr = ssh_pkt_getdata(pktin, 8);
2715 bombout(("SSH1 public key packet stopped before random cookie"));
2718 memcpy(cookie, ptr, 8);
2720 if (!ssh1_pkt_getrsakey(pktin, &servkey, &s->keystr1) ||
2721 !ssh1_pkt_getrsakey(pktin, &hostkey, &s->keystr2)) {
2722 bombout(("Failed to read SSH1 public keys from public key packet"));
2727 * Log the host key fingerprint.
2731 logevent("Host key fingerprint is:");
2732 strcpy(logmsg, " ");
2733 hostkey.comment = NULL;
2734 rsa_fingerprint(logmsg + strlen(logmsg),
2735 sizeof(logmsg) - strlen(logmsg), &hostkey);
2739 ssh->v1_remote_protoflags = ssh_pkt_getuint32(pktin);
2740 s->supported_ciphers_mask = ssh_pkt_getuint32(pktin);
2741 s->supported_auths_mask = ssh_pkt_getuint32(pktin);
2743 ssh->v1_local_protoflags =
2744 ssh->v1_remote_protoflags & SSH1_PROTOFLAGS_SUPPORTED;
2745 ssh->v1_local_protoflags |= SSH1_PROTOFLAG_SCREEN_NUMBER;
2748 MD5Update(&md5c, s->keystr2, hostkey.bytes);
2749 MD5Update(&md5c, s->keystr1, servkey.bytes);
2750 MD5Update(&md5c, cookie, 8);
2751 MD5Final(s->session_id, &md5c);
2753 for (i = 0; i < 32; i++)
2754 ssh->session_key[i] = random_byte();
2757 * Verify that the `bits' and `bytes' parameters match.
2759 if (hostkey.bits > hostkey.bytes * 8 ||
2760 servkey.bits > servkey.bytes * 8) {
2761 bombout(("SSH1 public keys were badly formatted"));
2765 s->len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
2767 s->rsabuf = snewn(s->len, unsigned char);
2769 fatalbox("Out of memory");
2772 * Verify the host key.
2776 * First format the key into a string.
2778 int len = rsastr_len(&hostkey);
2779 char fingerprint[100];
2780 char *keystr = snewn(len, char);
2782 fatalbox("Out of memory");
2783 rsastr_fmt(keystr, &hostkey);
2784 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
2785 verify_ssh_host_key(ssh->frontend,
2786 ssh->savedhost, ssh->savedport, "rsa", keystr,
2791 for (i = 0; i < 32; i++) {
2792 s->rsabuf[i] = ssh->session_key[i];
2794 s->rsabuf[i] ^= s->session_id[i];
2797 if (hostkey.bytes > servkey.bytes) {
2798 ret = rsaencrypt(s->rsabuf, 32, &servkey);
2800 ret = rsaencrypt(s->rsabuf, servkey.bytes, &hostkey);
2802 ret = rsaencrypt(s->rsabuf, 32, &hostkey);
2804 ret = rsaencrypt(s->rsabuf, hostkey.bytes, &servkey);
2807 bombout(("SSH1 public key encryptions failed due to bad formatting"));
2811 logevent("Encrypted session key");
2814 int cipher_chosen = 0, warn = 0;
2815 char *cipher_string = NULL;
2817 for (i = 0; !cipher_chosen && i < CIPHER_MAX; i++) {
2818 int next_cipher = ssh->cfg.ssh_cipherlist[i];
2819 if (next_cipher == CIPHER_WARN) {
2820 /* If/when we choose a cipher, warn about it */
2822 } else if (next_cipher == CIPHER_AES) {
2823 /* XXX Probably don't need to mention this. */
2824 logevent("AES not supported in SSH1, skipping");
2826 switch (next_cipher) {
2827 case CIPHER_3DES: s->cipher_type = SSH_CIPHER_3DES;
2828 cipher_string = "3DES"; break;
2829 case CIPHER_BLOWFISH: s->cipher_type = SSH_CIPHER_BLOWFISH;
2830 cipher_string = "Blowfish"; break;
2831 case CIPHER_DES: s->cipher_type = SSH_CIPHER_DES;
2832 cipher_string = "single-DES"; break;
2834 if (s->supported_ciphers_mask & (1 << s->cipher_type))
2838 if (!cipher_chosen) {
2839 if ((s->supported_ciphers_mask & (1 << SSH_CIPHER_3DES)) == 0)
2840 bombout(("Server violates SSH 1 protocol by not "
2841 "supporting 3DES encryption"));
2843 /* shouldn't happen */
2844 bombout(("No supported ciphers found"));
2848 /* Warn about chosen cipher if necessary. */
2850 sk_set_frozen(ssh->s, 1);
2851 askalg(ssh->frontend, "cipher", cipher_string);
2852 sk_set_frozen(ssh->s, 0);
2856 switch (s->cipher_type) {
2857 case SSH_CIPHER_3DES:
2858 logevent("Using 3DES encryption");
2860 case SSH_CIPHER_DES:
2861 logevent("Using single-DES encryption");
2863 case SSH_CIPHER_BLOWFISH:
2864 logevent("Using Blowfish encryption");
2868 send_packet(ssh, SSH1_CMSG_SESSION_KEY,
2869 PKT_CHAR, s->cipher_type,
2870 PKT_DATA, cookie, 8,
2871 PKT_CHAR, (s->len * 8) >> 8, PKT_CHAR, (s->len * 8) & 0xFF,
2872 PKT_DATA, s->rsabuf, s->len,
2873 PKT_INT, ssh->v1_local_protoflags, PKT_END);
2875 logevent("Trying to enable encryption...");
2879 ssh->cipher = (s->cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
2880 s->cipher_type == SSH_CIPHER_DES ? &ssh_des :
2882 ssh->v1_cipher_ctx = ssh->cipher->make_context();
2883 ssh->cipher->sesskey(ssh->v1_cipher_ctx, ssh->session_key);
2884 logeventf(ssh, "Initialised %s encryption", ssh->cipher->text_name);
2886 ssh->crcda_ctx = crcda_make_context();
2887 logevent("Installing CRC compensation attack detector");
2889 if (servkey.modulus) {
2890 sfree(servkey.modulus);
2891 servkey.modulus = NULL;
2893 if (servkey.exponent) {
2894 sfree(servkey.exponent);
2895 servkey.exponent = NULL;
2897 if (hostkey.modulus) {
2898 sfree(hostkey.modulus);
2899 hostkey.modulus = NULL;
2901 if (hostkey.exponent) {
2902 sfree(hostkey.exponent);
2903 hostkey.exponent = NULL;
2907 if (pktin->type != SSH1_SMSG_SUCCESS) {
2908 bombout(("Encryption not successfully enabled"));
2912 logevent("Successfully started encryption");
2916 if (!*ssh->cfg.username) {
2917 if (ssh_get_line && !ssh_getline_pw_only) {
2918 if (!ssh_get_line("login as: ",
2919 s->username, sizeof(s->username), FALSE)) {
2921 * get_line failed to get a username.
2924 logevent("No username provided. Abandoning session.");
2925 ssh_closing((Plug)ssh, NULL, 0, 0);
2929 int ret; /* need not be kept over crReturn */
2930 c_write_str(ssh, "login as: ");
2933 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
2935 crWaitUntil(!pktin);
2936 ret = process_userpass_input(ssh, in, inlen);
2940 c_write_str(ssh, "\r\n");
2943 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
2944 s->username[sizeof(s->username)-1] = '\0';
2947 send_packet(ssh, SSH1_CMSG_USER, PKT_STR, s->username, PKT_END);
2949 char userlog[22 + sizeof(s->username)];
2950 sprintf(userlog, "Sent username \"%s\"", s->username);
2952 if (flags & FLAG_INTERACTIVE &&
2953 (!((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)))) {
2954 strcat(userlog, "\r\n");
2955 c_write_str(ssh, userlog);
2962 if ((ssh->remote_bugs & BUG_CHOKES_ON_RSA)) {
2963 /* We must not attempt PK auth. Pretend we've already tried it. */
2964 s->tried_publickey = s->tried_agent = 1;
2966 s->tried_publickey = s->tried_agent = 0;
2968 s->tis_auth_refused = s->ccard_auth_refused = 0;
2969 /* Load the public half of ssh->cfg.keyfile so we notice if it's in Pageant */
2970 if (!filename_is_null(ssh->cfg.keyfile)) {
2971 if (!rsakey_pubblob(&ssh->cfg.keyfile,
2972 &s->publickey_blob, &s->publickey_bloblen, NULL))
2973 s->publickey_blob = NULL;
2975 s->publickey_blob = NULL;
2977 while (pktin->type == SSH1_SMSG_FAILURE) {
2978 s->pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
2980 if (agent_exists() && !s->tried_agent) {
2982 * Attempt RSA authentication using Pageant.
2988 logevent("Pageant is running. Requesting keys.");
2990 /* Request the keys held by the agent. */
2991 PUT_32BIT(s->request, 1);
2992 s->request[4] = SSH1_AGENTC_REQUEST_RSA_IDENTITIES;
2993 if (!agent_query(s->request, 5, &r, &s->responselen,
2994 ssh_agent_callback, ssh)) {
2998 bombout(("Unexpected data from server while waiting"
2999 " for agent response"));
3002 } while (pktin || inlen > 0);
3003 r = ssh->agent_response;
3004 s->responselen = ssh->agent_response_len;
3006 s->response = (unsigned char *) r;
3007 if (s->response && s->responselen >= 5 &&
3008 s->response[4] == SSH1_AGENT_RSA_IDENTITIES_ANSWER) {
3009 s->p = s->response + 5;
3010 s->nkeys = GET_32BIT(s->p);
3014 sprintf(buf, "Pageant has %d SSH1 keys", s->nkeys);
3017 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
3020 sprintf(buf, "Trying Pageant key #%d", s->keyi);
3023 if (s->publickey_blob &&
3024 !memcmp(s->p, s->publickey_blob,
3025 s->publickey_bloblen)) {
3026 logevent("This key matches configured key file");
3027 s->tried_publickey = 1;
3032 do { /* do while (0) to make breaking easy */
3033 n = ssh1_read_bignum
3034 (s->p, s->responselen-(s->p-s->response),
3039 n = ssh1_read_bignum
3040 (s->p, s->responselen-(s->p-s->response),
3045 if (s->responselen - (s->p-s->response) < 4)
3047 s->commentlen = GET_32BIT(s->p);
3049 if (s->responselen - (s->p-s->response) <
3052 s->commentp = (char *)s->p;
3053 s->p += s->commentlen;
3057 logevent("Pageant key list packet was truncated");
3061 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3062 PKT_BIGNUM, s->key.modulus, PKT_END);
3064 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3065 logevent("Key refused");
3068 logevent("Received RSA challenge");
3069 if ((s->challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3070 bombout(("Server's RSA challenge was badly formatted"));
3075 char *agentreq, *q, *ret;
3078 len = 1 + 4; /* message type, bit count */
3079 len += ssh1_bignum_length(s->key.exponent);
3080 len += ssh1_bignum_length(s->key.modulus);
3081 len += ssh1_bignum_length(s->challenge);
3082 len += 16; /* session id */
3083 len += 4; /* response format */
3084 agentreq = snewn(4 + len, char);
3085 PUT_32BIT(agentreq, len);
3087 *q++ = SSH1_AGENTC_RSA_CHALLENGE;
3088 PUT_32BIT(q, bignum_bitcount(s->key.modulus));
3090 q += ssh1_write_bignum(q, s->key.exponent);
3091 q += ssh1_write_bignum(q, s->key.modulus);
3092 q += ssh1_write_bignum(q, s->challenge);
3093 memcpy(q, s->session_id, 16);
3095 PUT_32BIT(q, 1); /* response format */
3096 if (!agent_query(agentreq, len + 4, &vret, &retlen,
3097 ssh_agent_callback, ssh)) {
3102 bombout(("Unexpected data from server"
3103 " while waiting for agent"
3107 } while (pktin || inlen > 0);
3108 vret = ssh->agent_response;
3109 retlen = ssh->agent_response_len;
3114 if (ret[4] == SSH1_AGENT_RSA_RESPONSE) {
3115 logevent("Sending Pageant's response");
3116 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3117 PKT_DATA, ret + 5, 16,
3121 if (pktin->type == SSH1_SMSG_SUCCESS) {
3123 ("Pageant's response accepted");
3124 if (flags & FLAG_VERBOSE) {
3125 c_write_str(ssh, "Authenticated using"
3127 c_write(ssh, s->commentp,
3129 c_write_str(ssh, "\" from agent\r\n");
3134 ("Pageant's response not accepted");
3137 ("Pageant failed to answer challenge");
3141 logevent("No reply received from Pageant");
3144 freebn(s->key.exponent);
3145 freebn(s->key.modulus);
3146 freebn(s->challenge);
3155 if (!filename_is_null(ssh->cfg.keyfile) && !s->tried_publickey)
3156 s->pwpkt_type = SSH1_CMSG_AUTH_RSA;
3158 if (ssh->cfg.try_tis_auth &&
3159 (s->supported_auths_mask & (1 << SSH1_AUTH_TIS)) &&
3160 !s->tis_auth_refused) {
3161 s->pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
3162 logevent("Requested TIS authentication");
3163 send_packet(ssh, SSH1_CMSG_AUTH_TIS, PKT_END);
3165 if (pktin->type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
3166 logevent("TIS authentication declined");
3167 if (flags & FLAG_INTERACTIVE)
3168 c_write_str(ssh, "TIS authentication refused.\r\n");
3169 s->tis_auth_refused = 1;
3175 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3177 bombout(("TIS challenge packet was badly formed"));
3180 logevent("Received TIS challenge");
3181 if (challengelen > sizeof(s->prompt) - 1)
3182 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3183 memcpy(s->prompt, challenge, challengelen);
3184 /* Prompt heuristic comes from OpenSSH */
3185 strncpy(s->prompt + challengelen,
3186 memchr(s->prompt, '\n', challengelen) ?
3187 "": "\r\nResponse: ",
3188 (sizeof s->prompt) - challengelen);
3189 s->prompt[(sizeof s->prompt) - 1] = '\0';
3192 if (ssh->cfg.try_tis_auth &&
3193 (s->supported_auths_mask & (1 << SSH1_AUTH_CCARD)) &&
3194 !s->ccard_auth_refused) {
3195 s->pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
3196 logevent("Requested CryptoCard authentication");
3197 send_packet(ssh, SSH1_CMSG_AUTH_CCARD, PKT_END);
3199 if (pktin->type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
3200 logevent("CryptoCard authentication declined");
3201 c_write_str(ssh, "CryptoCard authentication refused.\r\n");
3202 s->ccard_auth_refused = 1;
3208 ssh_pkt_getstring(pktin, &challenge, &challengelen);
3210 bombout(("CryptoCard challenge packet was badly formed"));
3213 logevent("Received CryptoCard challenge");
3214 if (challengelen > sizeof(s->prompt) - 1)
3215 challengelen = sizeof(s->prompt) - 1;/* prevent overrun */
3216 memcpy(s->prompt, challenge, challengelen);
3217 strncpy(s->prompt + challengelen,
3218 memchr(s->prompt, '\n', challengelen) ?
3219 "" : "\r\nResponse: ",
3220 sizeof(s->prompt) - challengelen);
3221 s->prompt[sizeof(s->prompt) - 1] = '\0';
3224 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3225 sprintf(s->prompt, "%.90s@%.90s's password: ",
3226 s->username, ssh->savedhost);
3228 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3229 char *comment = NULL;
3232 if (flags & FLAG_VERBOSE)
3233 c_write_str(ssh, "Trying public key authentication.\r\n");
3234 logeventf(ssh, "Trying public key \"%s\"",
3235 filename_to_str(&ssh->cfg.keyfile));
3236 type = key_type(&ssh->cfg.keyfile);
3237 if (type != SSH_KEYTYPE_SSH1) {
3238 sprintf(msgbuf, "Key is of wrong type (%s)",
3239 key_type_to_str(type));
3241 c_write_str(ssh, msgbuf);
3242 c_write_str(ssh, "\r\n");
3243 s->tried_publickey = 1;
3246 if (!rsakey_encrypted(&ssh->cfg.keyfile, &comment)) {
3247 if (flags & FLAG_VERBOSE)
3248 c_write_str(ssh, "No passphrase required.\r\n");
3251 sprintf(s->prompt, "Passphrase for key \"%.100s\": ", comment);
3256 * Show password prompt, having first obtained it via a TIS
3257 * or CryptoCard exchange if we're doing TIS or CryptoCard
3261 if (!ssh_get_line(s->prompt, s->password,
3262 sizeof(s->password), TRUE)) {
3264 * get_line failed to get a password (for example
3265 * because one was supplied on the command line
3266 * which has already failed to work). Terminate.
3268 send_packet(ssh, SSH1_MSG_DISCONNECT,
3269 PKT_STR, "No more passwords available to try",
3271 logevent("Unable to authenticate");
3272 connection_fatal(ssh->frontend, "Unable to authenticate");
3273 ssh_closing((Plug)ssh, NULL, 0, 0);
3277 /* Prompt may have come from server. We've munged it a bit, so
3278 * we know it to be zero-terminated at least once. */
3279 int ret; /* need not be saved over crReturn */
3280 c_write_untrusted(ssh, s->prompt, strlen(s->prompt));
3283 setup_userpass_input(ssh, s->password, sizeof(s->password), 0);
3285 crWaitUntil(!pktin);
3286 ret = process_userpass_input(ssh, in, inlen);
3290 c_write_str(ssh, "\r\n");
3294 if (s->pwpkt_type == SSH1_CMSG_AUTH_RSA) {
3296 * Try public key authentication with the specified
3299 s->tried_publickey = 1;
3302 const char *error = NULL;
3303 int ret = loadrsakey(&ssh->cfg.keyfile, &s->key, s->password,
3306 c_write_str(ssh, "Couldn't load private key from ");
3307 c_write_str(ssh, filename_to_str(&ssh->cfg.keyfile));
3308 c_write_str(ssh, " (");
3309 c_write_str(ssh, error);
3310 c_write_str(ssh, ").\r\n");
3311 continue; /* go and try password */
3314 c_write_str(ssh, "Wrong passphrase.\r\n");
3315 s->tried_publickey = 0;
3316 continue; /* try again */
3321 * Send a public key attempt.
3323 send_packet(ssh, SSH1_CMSG_AUTH_RSA,
3324 PKT_BIGNUM, s->key.modulus, PKT_END);
3327 if (pktin->type == SSH1_SMSG_FAILURE) {
3328 c_write_str(ssh, "Server refused our public key.\r\n");
3329 continue; /* go and try password */
3331 if (pktin->type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
3332 bombout(("Bizarre response to offer of public key"));
3338 unsigned char buffer[32];
3339 Bignum challenge, response;
3341 if ((challenge = ssh1_pkt_getmp(pktin)) == NULL) {
3342 bombout(("Server's RSA challenge was badly formatted"));
3345 response = rsadecrypt(challenge, &s->key);
3346 freebn(s->key.private_exponent);/* burn the evidence */
3348 for (i = 0; i < 32; i++) {
3349 buffer[i] = bignum_byte(response, 31 - i);
3353 MD5Update(&md5c, buffer, 32);
3354 MD5Update(&md5c, s->session_id, 16);
3355 MD5Final(buffer, &md5c);
3357 send_packet(ssh, SSH1_CMSG_AUTH_RSA_RESPONSE,
3358 PKT_DATA, buffer, 16, PKT_END);
3365 if (pktin->type == SSH1_SMSG_FAILURE) {
3366 if (flags & FLAG_VERBOSE)
3367 c_write_str(ssh, "Failed to authenticate with"
3368 " our public key.\r\n");
3369 continue; /* go and try password */
3370 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3371 bombout(("Bizarre response to RSA authentication response"));
3375 break; /* we're through! */
3377 if (s->pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
3379 * Defence against traffic analysis: we send a
3380 * whole bunch of packets containing strings of
3381 * different lengths. One of these strings is the
3382 * password, in a SSH1_CMSG_AUTH_PASSWORD packet.
3383 * The others are all random data in
3384 * SSH1_MSG_IGNORE packets. This way a passive
3385 * listener can't tell which is the password, and
3386 * hence can't deduce the password length.
3388 * Anybody with a password length greater than 16
3389 * bytes is going to have enough entropy in their
3390 * password that a listener won't find it _that_
3391 * much help to know how long it is. So what we'll
3394 * - if password length < 16, we send 15 packets
3395 * containing string lengths 1 through 15
3397 * - otherwise, we let N be the nearest multiple
3398 * of 8 below the password length, and send 8
3399 * packets containing string lengths N through
3400 * N+7. This won't obscure the order of
3401 * magnitude of the password length, but it will
3402 * introduce a bit of extra uncertainty.
3404 * A few servers (the old 1.2.18 through 1.2.22)
3405 * can't deal with SSH1_MSG_IGNORE. For these
3406 * servers, we need an alternative defence. We make
3407 * use of the fact that the password is interpreted
3408 * as a C string: so we can append a NUL, then some
3411 * One server (a Cisco one) can deal with neither
3412 * SSH1_MSG_IGNORE _nor_ a padded password string.
3413 * For this server we are left with no defences
3414 * against password length sniffing.
3416 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE)) {
3418 * The server can deal with SSH1_MSG_IGNORE, so
3419 * we can use the primary defence.
3421 int bottom, top, pwlen, i;
3424 pwlen = strlen(s->password);
3426 bottom = 0; /* zero length passwords are OK! :-) */
3429 bottom = pwlen & ~7;
3433 assert(pwlen >= bottom && pwlen <= top);
3435 randomstr = snewn(top + 1, char);
3437 for (i = bottom; i <= top; i++) {
3439 defer_packet(ssh, s->pwpkt_type,
3440 PKTT_PASSWORD, PKT_STR, s->password,
3441 PKTT_OTHER, PKT_END);
3443 for (j = 0; j < i; j++) {
3445 randomstr[j] = random_byte();
3446 } while (randomstr[j] == '\0');
3448 randomstr[i] = '\0';
3449 defer_packet(ssh, SSH1_MSG_IGNORE,
3450 PKT_STR, randomstr, PKT_END);
3453 logevent("Sending password with camouflage packets");
3454 ssh_pkt_defersend(ssh);
3457 else if (!(ssh->remote_bugs & BUG_NEEDS_SSH1_PLAIN_PASSWORD)) {
3459 * The server can't deal with SSH1_MSG_IGNORE
3460 * but can deal with padded passwords, so we
3461 * can use the secondary defence.
3467 len = strlen(s->password);
3468 if (len < sizeof(string)) {
3470 strcpy(string, s->password);
3471 len++; /* cover the zero byte */
3472 while (len < sizeof(string)) {
3473 string[len++] = (char) random_byte();
3478 logevent("Sending length-padded password");
3479 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3480 PKT_INT, len, PKT_DATA, ss, len,
3481 PKTT_OTHER, PKT_END);
3484 * The server has _both_
3485 * BUG_CHOKES_ON_SSH1_IGNORE and
3486 * BUG_NEEDS_SSH1_PLAIN_PASSWORD. There is
3487 * therefore nothing we can do.
3490 len = strlen(s->password);
3491 logevent("Sending unpadded password");
3492 send_packet(ssh, s->pwpkt_type,
3493 PKTT_PASSWORD, PKT_INT, len,
3494 PKT_DATA, s->password, len,
3495 PKTT_OTHER, PKT_END);
3498 send_packet(ssh, s->pwpkt_type, PKTT_PASSWORD,
3499 PKT_STR, s->password, PKTT_OTHER, PKT_END);
3502 logevent("Sent password");
3503 memset(s->password, 0, strlen(s->password));
3505 if (pktin->type == SSH1_SMSG_FAILURE) {
3506 if (flags & FLAG_VERBOSE)
3507 c_write_str(ssh, "Access denied\r\n");
3508 logevent("Authentication refused");
3509 } else if (pktin->type != SSH1_SMSG_SUCCESS) {
3510 bombout(("Strange packet received, type %d", pktin->type));
3515 logevent("Authentication successful");
3520 void sshfwd_close(struct ssh_channel *c)
3524 if (ssh->state != SSH_STATE_SESSION) {
3525 assert(ssh->state == SSH_STATE_CLOSED);
3529 if (c && !c->closes) {
3531 * If the channel's remoteid is -1, we have sent
3532 * CHANNEL_OPEN for this channel, but it hasn't even been
3533 * acknowledged by the server. So we must set a close flag
3534 * on it now, and then when the server acks the channel
3535 * open, we can close it then.
3537 if (((int)c->remoteid) != -1) {
3538 if (ssh->version == 1) {
3539 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE, PKT_INT, c->remoteid,
3542 struct Packet *pktout;
3543 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
3544 ssh2_pkt_adduint32(pktout, c->remoteid);
3545 ssh2_pkt_send(ssh, pktout);
3548 c->closes = 1; /* sent MSG_CLOSE */
3549 if (c->type == CHAN_X11) {
3551 logevent("Forwarded X11 connection terminated");
3552 } else if (c->type == CHAN_SOCKDATA ||
3553 c->type == CHAN_SOCKDATA_DORMANT) {
3555 logevent("Forwarded port closed");
3560 int sshfwd_write(struct ssh_channel *c, char *buf, int len)
3564 if (ssh->state != SSH_STATE_SESSION) {
3565 assert(ssh->state == SSH_STATE_CLOSED);
3569 if (ssh->version == 1) {
3570 send_packet(ssh, SSH1_MSG_CHANNEL_DATA,
3571 PKT_INT, c->remoteid,
3573 PKT_INT, len, PKT_DATA, buf, len,
3574 PKTT_OTHER, PKT_END);
3576 * In SSH1 we can return 0 here - implying that forwarded
3577 * connections are never individually throttled - because
3578 * the only circumstance that can cause throttling will be
3579 * the whole SSH connection backing up, in which case
3580 * _everything_ will be throttled as a whole.
3584 ssh2_add_channel_data(c, buf, len);
3585 return ssh2_try_send(c);
3589 void sshfwd_unthrottle(struct ssh_channel *c, int bufsize)
3593 if (ssh->state != SSH_STATE_SESSION) {
3594 assert(ssh->state == SSH_STATE_CLOSED);
3598 if (ssh->version == 1) {
3599 if (c->v.v1.throttling && bufsize < SSH1_BUFFER_LIMIT) {
3600 c->v.v1.throttling = 0;
3601 ssh1_throttle(ssh, -1);
3604 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
3608 static void ssh_queueing_handler(Ssh ssh, struct Packet *pktin)
3610 struct queued_handler *qh = ssh->qhead;
3614 assert(pktin->type == qh->msg1 || pktin->type == qh->msg2);
3617 assert(ssh->packet_dispatch[qh->msg1] == ssh_queueing_handler);
3618 ssh->packet_dispatch[qh->msg1] = NULL;
3621 assert(ssh->packet_dispatch[qh->msg2] == ssh_queueing_handler);
3622 ssh->packet_dispatch[qh->msg2] = NULL;
3626 ssh->qhead = qh->next;
3628 if (ssh->qhead->msg1 > 0) {
3629 assert(ssh->packet_dispatch[ssh->qhead->msg1] == NULL);
3630 ssh->packet_dispatch[ssh->qhead->msg1] = ssh_queueing_handler;
3632 if (ssh->qhead->msg2 > 0) {
3633 assert(ssh->packet_dispatch[ssh->qhead->msg2] == NULL);
3634 ssh->packet_dispatch[ssh->qhead->msg2] = ssh_queueing_handler;
3637 ssh->qhead = ssh->qtail = NULL;
3638 ssh->packet_dispatch[pktin->type] = NULL;
3641 qh->handler(ssh, pktin, qh->ctx);
3646 static void ssh_queue_handler(Ssh ssh, int msg1, int msg2,
3647 chandler_fn_t handler, void *ctx)
3649 struct queued_handler *qh;
3651 qh = snew(struct queued_handler);
3654 qh->handler = handler;
3658 if (ssh->qtail == NULL) {
3662 assert(ssh->packet_dispatch[qh->msg1] == NULL);
3663 ssh->packet_dispatch[qh->msg1] = ssh_queueing_handler;
3666 assert(ssh->packet_dispatch[qh->msg2] == NULL);
3667 ssh->packet_dispatch[qh->msg2] = ssh_queueing_handler;
3670 ssh->qtail->next = qh;
3675 static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
3677 struct ssh_rportfwd *rpf, *pf = (struct ssh_rportfwd *)ctx;
3679 if (pktin->type == (ssh->version == 1 ? SSH1_SMSG_SUCCESS :
3680 SSH2_MSG_REQUEST_SUCCESS)) {
3681 logeventf(ssh, "Remote port forwarding from %s enabled",
3684 logeventf(ssh, "Remote port forwarding from %s refused",
3687 rpf = del234(ssh->rportfwds, pf);
3693 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
3695 const char *portfwd_strptr = cfg->portfwd;
3696 struct ssh_portfwd *epf;
3699 if (!ssh->portfwds) {
3700 ssh->portfwds = newtree234(ssh_portcmp);
3703 * Go through the existing port forwardings and tag them
3704 * with status==DESTROY. Any that we want to keep will be
3705 * re-enabled (status==KEEP) as we go through the
3706 * configuration and find out which bits are the same as
3709 struct ssh_portfwd *epf;
3711 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3712 epf->status = DESTROY;
3715 while (*portfwd_strptr) {
3716 char address_family, type;
3717 int sport,dport,sserv,dserv;
3718 char sports[256], dports[256], saddr[256], host[256];
3721 address_family = 'A';
3723 if (*portfwd_strptr == 'A' ||
3724 *portfwd_strptr == '4' ||
3725 *portfwd_strptr == '6')
3726 address_family = *portfwd_strptr++;
3727 if (*portfwd_strptr == 'L' ||
3728 *portfwd_strptr == 'R' ||
3729 *portfwd_strptr == 'D')
3730 type = *portfwd_strptr++;
3735 while (*portfwd_strptr && *portfwd_strptr != '\t') {
3736 if (*portfwd_strptr == ':') {
3738 * We've seen a colon in the middle of the
3739 * source port number. This means that
3740 * everything we've seen until now is the
3741 * source _address_, so we'll move it into
3742 * saddr and start sports from the beginning
3747 if (ssh->version == 1 && type == 'R') {
3748 logeventf(ssh, "SSH1 cannot handle remote source address "
3749 "spec \"%s\"; ignoring", sports);
3751 strcpy(saddr, sports);
3754 if (n < 255) sports[n++] = *portfwd_strptr++;
3758 if (*portfwd_strptr == '\t')
3761 while (*portfwd_strptr && *portfwd_strptr != ':') {
3762 if (n < 255) host[n++] = *portfwd_strptr++;
3765 if (*portfwd_strptr == ':')
3768 while (*portfwd_strptr) {
3769 if (n < 255) dports[n++] = *portfwd_strptr++;
3773 dport = atoi(dports);
3777 dport = net_service_lookup(dports);
3779 logeventf(ssh, "Service lookup failed for destination"
3780 " port \"%s\"", dports);
3784 while (*portfwd_strptr) portfwd_strptr++;
3786 portfwd_strptr++; /* eat the NUL and move to next one */
3788 sport = atoi(sports);
3792 sport = net_service_lookup(sports);
3794 logeventf(ssh, "Service lookup failed for source"
3795 " port \"%s\"", sports);
3798 if (sport && dport) {
3799 /* Set up a description of the source port. */
3800 struct ssh_portfwd *pfrec, *epfrec;
3802 pfrec = snew(struct ssh_portfwd);
3804 pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
3805 pfrec->sserv = sserv ? dupstr(sports) : NULL;
3806 pfrec->sport = sport;
3807 pfrec->daddr = *host ? dupstr(host) : NULL;
3808 pfrec->dserv = dserv ? dupstr(dports) : NULL;
3809 pfrec->dport = dport;
3810 pfrec->local = NULL;
3811 pfrec->remote = NULL;
3812 pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
3813 address_family == '6' ? ADDRTYPE_IPV6 :
3816 epfrec = add234(ssh->portfwds, pfrec);
3817 if (epfrec != pfrec) {
3819 * We already have a port forwarding with precisely
3820 * these parameters. Hence, no need to do anything;
3821 * simply tag the existing one as KEEP.
3823 epfrec->status = KEEP;
3824 free_portfwd(pfrec);
3826 pfrec->status = CREATE;
3832 * Now go through and destroy any port forwardings which were
3835 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3836 if (epf->status == DESTROY) {
3839 message = dupprintf("%s port forwarding from %s%s%d",
3840 epf->type == 'L' ? "local" :
3841 epf->type == 'R' ? "remote" : "dynamic",
3842 epf->saddr ? epf->saddr : "",
3843 epf->saddr ? ":" : "",
3846 if (epf->type != 'D') {
3847 char *msg2 = dupprintf("%s to %s:%d", message,
3848 epf->daddr, epf->dport);
3853 logeventf(ssh, "Cancelling %s", message);
3857 struct ssh_rportfwd *rpf = epf->remote;
3858 struct Packet *pktout;
3861 * Cancel the port forwarding at the server
3864 if (ssh->version == 1) {
3866 * We cannot cancel listening ports on the
3867 * server side in SSH1! There's no message
3868 * to support it. Instead, we simply remove
3869 * the rportfwd record from the local end
3870 * so that any connections the server tries
3871 * to make on it are rejected.
3874 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3875 ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
3876 ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
3878 ssh2_pkt_addstring(pktout, epf->saddr);
3879 } else if (ssh->cfg.rport_acceptall) {
3880 ssh2_pkt_addstring(pktout, "0.0.0.0");
3882 ssh2_pkt_addstring(pktout, "127.0.0.1");
3884 ssh2_pkt_adduint32(pktout, epf->sport);
3885 ssh2_pkt_send(ssh, pktout);
3888 del234(ssh->rportfwds, rpf);
3890 } else if (epf->local) {
3891 pfd_terminate(epf->local);
3894 delpos234(ssh->portfwds, i);
3896 i--; /* so we don't skip one in the list */
3900 * And finally, set up any new port forwardings (status==CREATE).
3902 for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
3903 if (epf->status == CREATE) {
3904 char *sportdesc, *dportdesc;
3905 sportdesc = dupprintf("%s%s%s%s%d%s",
3906 epf->saddr ? epf->saddr : "",
3907 epf->saddr ? ":" : "",
3908 epf->sserv ? epf->sserv : "",
3909 epf->sserv ? "(" : "",
3911 epf->sserv ? ")" : "");
3912 if (epf->type == 'D') {
3915 dportdesc = dupprintf("%s:%s%s%d%s",
3917 epf->dserv ? epf->dserv : "",
3918 epf->dserv ? "(" : "",
3920 epf->dserv ? ")" : "");
3923 if (epf->type == 'L') {
3924 const char *err = pfd_addforward(epf->daddr, epf->dport,
3925 epf->saddr, epf->sport,
3928 epf->addressfamily);
3930 logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
3931 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3932 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3933 sportdesc, dportdesc,
3934 err ? " failed: " : "", err ? err : "");
3935 } else if (epf->type == 'D') {
3936 const char *err = pfd_addforward(NULL, -1,
3937 epf->saddr, epf->sport,
3940 epf->addressfamily);
3942 logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
3943 epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
3944 epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
3946 err ? " failed: " : "", err ? err : "");
3948 struct ssh_rportfwd *pf;
3951 * Ensure the remote port forwardings tree exists.
3953 if (!ssh->rportfwds) {
3954 if (ssh->version == 1)
3955 ssh->rportfwds = newtree234(ssh_rportcmp_ssh1);
3957 ssh->rportfwds = newtree234(ssh_rportcmp_ssh2);
3960 pf = snew(struct ssh_rportfwd);
3961 strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
3962 pf->dhost[lenof(pf->dhost)-1] = '\0';
3963 pf->dport = epf->dport;
3964 pf->sport = epf->sport;
3965 if (add234(ssh->rportfwds, pf) != pf) {
3966 logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
3967 epf->daddr, epf->dport);
3970 logeventf(ssh, "Requesting remote port %s"
3971 " forward to %s", sportdesc, dportdesc);
3973 pf->sportdesc = sportdesc;
3978 if (ssh->version == 1) {
3979 send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
3980 PKT_INT, epf->sport,
3981 PKT_STR, epf->daddr,
3982 PKT_INT, epf->dport,
3984 ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
3986 ssh_rportfwd_succfail, pf);
3988 struct Packet *pktout;
3989 pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
3990 ssh2_pkt_addstring(pktout, "tcpip-forward");
3991 ssh2_pkt_addbool(pktout, 1);/* want reply */
3993 ssh2_pkt_addstring(pktout, epf->saddr);
3994 } else if (ssh->cfg.rport_acceptall) {
3995 ssh2_pkt_addstring(pktout, "0.0.0.0");
3997 ssh2_pkt_addstring(pktout, "127.0.0.1");
3999 ssh2_pkt_adduint32(pktout, epf->sport);
4000 ssh2_pkt_send(ssh, pktout);
4002 ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
4003 SSH2_MSG_REQUEST_FAILURE,
4004 ssh_rportfwd_succfail, pf);
4013 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
4016 int stringlen, bufsize;
4018 ssh_pkt_getstring(pktin, &string, &stringlen);
4019 if (string == NULL) {
4020 bombout(("Incoming terminal data packet was badly formed"));
4024 bufsize = from_backend(ssh->frontend, pktin->type == SSH1_SMSG_STDERR_DATA,
4026 if (!ssh->v1_stdout_throttling && bufsize > SSH1_BUFFER_LIMIT) {
4027 ssh->v1_stdout_throttling = 1;
4028 ssh1_throttle(ssh, +1);
4032 static void ssh1_smsg_x11_open(Ssh ssh, struct Packet *pktin)
4034 /* Remote side is trying to open a channel to talk to our
4035 * X-Server. Give them back a local channel number. */
4036 struct ssh_channel *c;
4037 int remoteid = ssh_pkt_getuint32(pktin);
4039 logevent("Received X11 connect request");
4040 /* Refuse if X11 forwarding is disabled. */
4041 if (!ssh->X11_fwd_enabled) {
4042 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4043 PKT_INT, remoteid, PKT_END);
4044 logevent("Rejected X11 connect request");
4046 c = snew(struct ssh_channel);
4049 if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
4050 ssh->x11auth, NULL, -1, &ssh->cfg) != NULL) {
4051 logevent("Opening X11 forward connection failed");
4053 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4054 PKT_INT, remoteid, PKT_END);
4057 ("Opening X11 forward connection succeeded");
4058 c->remoteid = remoteid;
4059 c->localid = alloc_channel_id(ssh);
4061 c->v.v1.throttling = 0;
4062 c->type = CHAN_X11; /* identify channel type */
4063 add234(ssh->channels, c);
4064 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4065 PKT_INT, c->remoteid, PKT_INT,
4066 c->localid, PKT_END);
4067 logevent("Opened X11 forward channel");
4072 static void ssh1_smsg_agent_open(Ssh ssh, struct Packet *pktin)
4074 /* Remote side is trying to open a channel to talk to our
4075 * agent. Give them back a local channel number. */
4076 struct ssh_channel *c;
4077 int remoteid = ssh_pkt_getuint32(pktin);
4079 /* Refuse if agent forwarding is disabled. */
4080 if (!ssh->agentfwd_enabled) {
4081 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4082 PKT_INT, remoteid, PKT_END);
4084 c = snew(struct ssh_channel);
4086 c->remoteid = remoteid;
4087 c->localid = alloc_channel_id(ssh);
4089 c->v.v1.throttling = 0;
4090 c->type = CHAN_AGENT; /* identify channel type */
4091 c->u.a.lensofar = 0;
4092 add234(ssh->channels, c);
4093 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4094 PKT_INT, c->remoteid, PKT_INT, c->localid,
4099 static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
4101 /* Remote side is trying to open a channel to talk to a
4102 * forwarded port. Give them back a local channel number. */
4103 struct ssh_channel *c;
4104 struct ssh_rportfwd pf, *pfp;
4107 char *host, buf[1024];
4109 c = snew(struct ssh_channel);
4112 remoteid = ssh_pkt_getuint32(pktin);
4113 ssh_pkt_getstring(pktin, &host, &hostsize);
4114 port = ssh_pkt_getuint32(pktin);
4116 if (hostsize >= lenof(pf.dhost))
4117 hostsize = lenof(pf.dhost)-1;
4118 memcpy(pf.dhost, host, hostsize);
4119 pf.dhost[hostsize] = '\0';
4121 pfp = find234(ssh->rportfwds, &pf, NULL);
4124 sprintf(buf, "Rejected remote port open request for %s:%d",
4127 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4128 PKT_INT, remoteid, PKT_END);
4130 sprintf(buf, "Received remote port open request for %s:%d",
4133 e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
4134 c, &ssh->cfg, pfp->pfrec->addressfamily);
4137 sprintf(buf, "Port open failed: %s", e);
4140 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_FAILURE,
4141 PKT_INT, remoteid, PKT_END);
4143 c->remoteid = remoteid;
4144 c->localid = alloc_channel_id(ssh);
4146 c->v.v1.throttling = 0;
4147 c->type = CHAN_SOCKDATA; /* identify channel type */
4148 add234(ssh->channels, c);
4149 send_packet(ssh, SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
4150 PKT_INT, c->remoteid, PKT_INT,
4151 c->localid, PKT_END);
4152 logevent("Forwarded port opened successfully");
4157 static void ssh1_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
4159 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4160 unsigned int localid = ssh_pkt_getuint32(pktin);
4161 struct ssh_channel *c;
4163 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4164 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4165 c->remoteid = localid;
4166 c->type = CHAN_SOCKDATA;
4167 c->v.v1.throttling = 0;
4168 pfd_confirm(c->u.pfd.s);
4171 if (c && c->closes) {
4173 * We have a pending close on this channel,
4174 * which we decided on before the server acked
4175 * the channel open. So now we know the
4176 * remoteid, we can close it again.
4178 send_packet(ssh, SSH1_MSG_CHANNEL_CLOSE,
4179 PKT_INT, c->remoteid, PKT_END);
4183 static void ssh1_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
4185 unsigned int remoteid = ssh_pkt_getuint32(pktin);
4186 struct ssh_channel *c;
4188 c = find234(ssh->channels, &remoteid, ssh_channelfind);
4189 if (c && c->type == CHAN_SOCKDATA_DORMANT) {
4190 logevent("Forwarded connection refused by server");
4191 pfd_close(c->u.pfd.s);
4192 del234(ssh->channels, c);
4197 static void ssh1_msg_channel_close(Ssh ssh, struct Packet *pktin)
4199 /* Remote side closes a channel. */
4200 unsigned i = ssh_pkt_getuint32(pktin);
4201 struct ssh_channel *c;
4202 c = find234(ssh->channels, &i, ssh_channelfind);
4203 if (c && ((int)c->remoteid) != -1) {
4206 (pktin->type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
4208 if ((c->closes == 0) && (c->type == CHAN_X11)) {
4209 logevent("Forwarded X11 connection terminated");
4210 assert(c->u.x11.s != NULL);
4211 x11_close(c->u.x11.s);
4214 if ((c->closes == 0) && (c->type == CHAN_SOCKDATA)) {
4215 logevent("Forwarded port closed");
4216 assert(c->u.pfd.s != NULL);
4217 pfd_close(c->u.pfd.s);
4221 c->closes |= (closetype << 2); /* seen this message */
4222 if (!(c->closes & closetype)) {
4223 send_packet(ssh, pktin->type, PKT_INT, c->remoteid,
4225 c->closes |= closetype; /* sent it too */
4228 if (c->closes == 15) {
4229 del234(ssh->channels, c);
4233 bombout(("Received CHANNEL_CLOSE%s for %s channel %d\n",
4234 pktin->type == SSH1_MSG_CHANNEL_CLOSE ? "" :
4235 "_CONFIRMATION", c ? "half-open" : "nonexistent",
4240 static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
4242 /* Data sent down one of our channels. */
4243 int i = ssh_pkt_getuint32(pktin);
4246 struct ssh_channel *c;
4248 ssh_pkt_getstring(pktin, &p, &len);
4250 c = find234(ssh->channels, &i, ssh_channelfind);
4255 bufsize = x11_send(c->u.x11.s, p, len);
4258 bufsize = pfd_send(c->u.pfd.s, p, len);
4261 /* Data for an agent message. Buffer it. */
4263 if (c->u.a.lensofar < 4) {
4264 unsigned int l = min(4 - c->u.a.lensofar, len);
4265 memcpy(c->u.a.msglen + c->u.a.lensofar, p,
4269 c->u.a.lensofar += l;
4271 if (c->u.a.lensofar == 4) {
4273 4 + GET_32BIT(c->u.a.msglen);
4274 c->u.a.message = snewn(c->u.a.totallen,
4276 memcpy(c->u.a.message, c->u.a.msglen, 4);
4278 if (c->u.a.lensofar >= 4 && len > 0) {
4280 min(c->u.a.totallen - c->u.a.lensofar,
4282 memcpy(c->u.a.message + c->u.a.lensofar, p,
4286 c->u.a.lensofar += l;
4288 if (c->u.a.lensofar == c->u.a.totallen) {
4291 if (agent_query(c->u.a.message,
4294 ssh_agentf_callback, c))
4295 ssh_agentf_callback(c, reply, replylen);
4296 sfree(c->u.a.message);
4297 c->u.a.lensofar = 0;
4300 bufsize = 0; /* agent channels never back up */
4303 if (!c->v.v1.throttling && bufsize > SSH1_BUFFER_LIMIT) {
4304 c->v.v1.throttling = 1;
4305 ssh1_throttle(ssh, +1);
4310 static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
4313 ssh->exitcode = ssh_pkt_getuint32(pktin);
4314 sprintf(buf, "Server sent command exit status %d",
4317 send_packet(ssh, SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
4319 * In case `helpful' firewalls or proxies tack
4320 * extra human-readable text on the end of the
4321 * session which we might mistake for another
4322 * encrypted packet, we close the session once
4323 * we've sent EXIT_CONFIRMATION.
4325 ssh_closing((Plug)ssh, NULL, 0, 0);
4328 static void do_ssh1_connection(Ssh ssh, unsigned char *in, int inlen,
4329 struct Packet *pktin)
4331 crBegin(ssh->do_ssh1_connection_crstate);
4333 ssh->packet_dispatch[SSH1_SMSG_STDOUT_DATA] =
4334 ssh->packet_dispatch[SSH1_SMSG_STDERR_DATA] =
4335 ssh1_smsg_stdout_stderr_data;
4337 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_CONFIRMATION] =
4338 ssh1_msg_channel_open_confirmation;
4339 ssh->packet_dispatch[SSH1_MSG_CHANNEL_OPEN_FAILURE] =
4340 ssh1_msg_channel_open_failure;
4341 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE] =
4342 ssh->packet_dispatch[SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION] =
4343 ssh1_msg_channel_close;
4344 ssh->packet_dispatch[SSH1_MSG_CHANNEL_DATA] = ssh1_msg_channel_data;
4345 ssh->packet_dispatch[SSH1_SMSG_EXIT_STATUS] = ssh1_smsg_exit_status;
4347 if (ssh->cfg.agentfwd && agent_exists()) {
4348 logevent("Requesting agent forwarding");
4349 send_packet(ssh, SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
4353 if (pktin->type != SSH1_SMSG_SUCCESS
4354 && pktin->type != SSH1_SMSG_FAILURE) {
4355 bombout(("Protocol confusion"));
4357 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4358 logevent("Agent forwarding refused");
4360 logevent("Agent forwarding enabled");
4361 ssh->agentfwd_enabled = TRUE;
4362 ssh->packet_dispatch[SSH1_SMSG_AGENT_OPEN] = ssh1_smsg_agent_open;
4366 if (ssh->cfg.x11_forward) {
4367 char proto[20], data[64];
4368 logevent("Requesting X11 forwarding");
4369 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
4370 data, sizeof(data), ssh->cfg.x11_auth);
4371 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
4372 if (ssh->v1_local_protoflags & SSH1_PROTOFLAG_SCREEN_NUMBER) {
4373 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4374 PKT_STR, proto, PKT_STR, data,
4375 PKT_INT, x11_get_screen_number(ssh->cfg.x11_display),
4378 send_packet(ssh, SSH1_CMSG_X11_REQUEST_FORWARDING,
4379 PKT_STR, proto, PKT_STR, data, PKT_END);
4384 if (pktin->type != SSH1_SMSG_SUCCESS
4385 && pktin->type != SSH1_SMSG_FAILURE) {
4386 bombout(("Protocol confusion"));
4388 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4389 logevent("X11 forwarding refused");
4391 logevent("X11 forwarding enabled");
4392 ssh->X11_fwd_enabled = TRUE;
4393 ssh->packet_dispatch[SSH1_SMSG_X11_OPEN] = ssh1_smsg_x11_open;
4397 ssh_setup_portfwd(ssh, &ssh->cfg);
4398 ssh->packet_dispatch[SSH1_MSG_PORT_OPEN] = ssh1_msg_port_open;
4400 if (!ssh->cfg.nopty) {
4401 /* Unpick the terminal-speed string. */
4402 /* XXX perhaps we should allow no speeds to be sent. */
4403 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
4404 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
4405 /* Send the pty request. */
4406 send_packet(ssh, SSH1_CMSG_REQUEST_PTY,
4407 PKT_STR, ssh->cfg.termtype,
4408 PKT_INT, ssh->term_height,
4409 PKT_INT, ssh->term_width,
4410 PKT_INT, 0, PKT_INT, 0, /* width,height in pixels */
4411 PKT_CHAR, 192, PKT_INT, ssh->ispeed, /* TTY_OP_ISPEED */
4412 PKT_CHAR, 193, PKT_INT, ssh->ospeed, /* TTY_OP_OSPEED */
4413 PKT_CHAR, 0, PKT_END);
4414 ssh->state = SSH_STATE_INTERMED;
4418 if (pktin->type != SSH1_SMSG_SUCCESS
4419 && pktin->type != SSH1_SMSG_FAILURE) {
4420 bombout(("Protocol confusion"));
4422 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4423 c_write_str(ssh, "Server refused to allocate pty\r\n");
4424 ssh->editing = ssh->echoing = 1;
4426 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
4427 ssh->ospeed, ssh->ispeed);
4429 ssh->editing = ssh->echoing = 1;
4432 if (ssh->cfg.compression) {
4433 send_packet(ssh, SSH1_CMSG_REQUEST_COMPRESSION, PKT_INT, 6, PKT_END);
4437 if (pktin->type != SSH1_SMSG_SUCCESS
4438 && pktin->type != SSH1_SMSG_FAILURE) {
4439 bombout(("Protocol confusion"));
4441 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4442 c_write_str(ssh, "Server refused to compress\r\n");
4444 logevent("Started compression");
4445 ssh->v1_compressing = TRUE;
4446 ssh->cs_comp_ctx = zlib_compress_init();
4447 logevent("Initialised zlib (RFC1950) compression");
4448 ssh->sc_comp_ctx = zlib_decompress_init();
4449 logevent("Initialised zlib (RFC1950) decompression");
4453 * Start the shell or command.
4455 * Special case: if the first-choice command is an SSH2
4456 * subsystem (hence not usable here) and the second choice
4457 * exists, we fall straight back to that.
4460 char *cmd = ssh->cfg.remote_cmd_ptr;
4462 if (ssh->cfg.ssh_subsys && ssh->cfg.remote_cmd_ptr2) {
4463 cmd = ssh->cfg.remote_cmd_ptr2;
4464 ssh->fallback_cmd = TRUE;
4467 send_packet(ssh, SSH1_CMSG_EXEC_CMD, PKT_STR, cmd, PKT_END);
4469 send_packet(ssh, SSH1_CMSG_EXEC_SHELL, PKT_END);
4470 logevent("Started session");
4473 ssh->state = SSH_STATE_SESSION;
4474 if (ssh->size_needed)
4475 ssh_size(ssh, ssh->term_width, ssh->term_height);
4476 if (ssh->eof_needed)
4477 ssh_special(ssh, TS_EOF);
4480 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
4482 ssh->channels = newtree234(ssh_channelcmp);
4486 * By this point, most incoming packets are already being
4487 * handled by the dispatch table, and we need only pay
4488 * attention to the unusual ones.
4493 if (pktin->type == SSH1_SMSG_SUCCESS) {
4494 /* may be from EXEC_SHELL on some servers */
4495 } else if (pktin->type == SSH1_SMSG_FAILURE) {
4496 /* may be from EXEC_SHELL on some servers
4497 * if no pty is available or in other odd cases. Ignore */
4499 bombout(("Strange packet received: type %d", pktin->type));
4504 int len = min(inlen, 512);
4505 send_packet(ssh, SSH1_CMSG_STDIN_DATA, PKTT_DATA,
4506 PKT_INT, len, PKT_DATA, in, len,
4507 PKTT_OTHER, PKT_END);
4518 * Handle the top-level SSH2 protocol.
4520 static void ssh1_msg_debug(Ssh ssh, struct Packet *pktin)
4525 ssh_pkt_getstring(pktin, &msg, &msglen);
4526 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
4531 static void ssh1_msg_disconnect(Ssh ssh, struct Packet *pktin)
4533 /* log reason code in disconnect message */
4537 ssh_pkt_getstring(pktin, &msg, &msglen);
4538 bombout(("Server sent disconnect message:\n\"%.*s\"", msglen, msg));
4541 void ssh_msg_ignore(Ssh ssh, struct Packet *pktin)
4543 /* Do nothing, because we're ignoring it! Duhh. */
4546 static void ssh1_protocol_setup(Ssh ssh)
4551 * Most messages are handled by the coroutines.
4553 for (i = 0; i < 256; i++)
4554 ssh->packet_dispatch[i] = NULL;
4557 * These special message types we install handlers for.
4559 ssh->packet_dispatch[SSH1_MSG_DISCONNECT] = ssh1_msg_disconnect;
4560 ssh->packet_dispatch[SSH1_MSG_IGNORE] = ssh_msg_ignore;
4561 ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
4564 static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
4565 struct Packet *pktin)
4567 if (ssh->state == SSH_STATE_CLOSED)
4570 if (pktin && ssh->packet_dispatch[pktin->type]) {
4571 ssh->packet_dispatch[pktin->type](ssh, pktin);
4575 if (!ssh->protocol_initial_phase_done) {
4576 if (do_ssh1_login(ssh, in, inlen, pktin))
4577 ssh->protocol_initial_phase_done = TRUE;
4582 do_ssh1_connection(ssh, in, inlen, pktin);
4586 * Utility routine for decoding comma-separated strings in KEXINIT.
4588 static int in_commasep_string(char *needle, char *haystack, int haylen)
4591 if (!needle || !haystack) /* protect against null pointers */
4593 needlen = strlen(needle);
4596 * Is it at the start of the string?
4598 if (haylen >= needlen && /* haystack is long enough */
4599 !memcmp(needle, haystack, needlen) && /* initial match */
4600 (haylen == needlen || haystack[needlen] == ',')
4601 /* either , or EOS follows */
4605 * If not, search for the next comma and resume after that.
4606 * If no comma found, terminate.
4608 while (haylen > 0 && *haystack != ',')
4609 haylen--, haystack++;
4612 haylen--, haystack++; /* skip over comma itself */
4617 * SSH2 key creation method.
4619 static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
4620 unsigned char *sessid, char chr,
4621 unsigned char *keyspace)
4624 /* First 20 bytes. */
4626 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4628 SHA_Bytes(&s, H, 20);
4629 SHA_Bytes(&s, &chr, 1);
4630 SHA_Bytes(&s, sessid, 20);
4631 SHA_Final(&s, keyspace);
4632 /* Next 20 bytes. */
4634 if (!(ssh->remote_bugs & BUG_SSH2_DERIVEKEY))
4636 SHA_Bytes(&s, H, 20);
4637 SHA_Bytes(&s, keyspace, 20);
4638 SHA_Final(&s, keyspace + 20);
4642 * Handle the SSH2 transport layer.
4644 static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
4645 struct Packet *pktin)
4647 struct do_ssh2_transport_state {
4648 int nbits, pbits, warn;
4649 Bignum p, g, e, f, K;
4650 int kex_init_value, kex_reply_value;
4651 const struct ssh_mac **maclist;
4653 const struct ssh2_cipher *cscipher_tobe;
4654 const struct ssh2_cipher *sccipher_tobe;
4655 const struct ssh_mac *csmac_tobe;
4656 const struct ssh_mac *scmac_tobe;
4657 const struct ssh_compress *cscomp_tobe;
4658 const struct ssh_compress *sccomp_tobe;
4659 char *hostkeydata, *sigdata, *keystr, *fingerprint;
4660 int hostkeylen, siglen;
4661 void *hkey; /* actual host key */
4662 unsigned char exchange_hash[20];
4663 int n_preferred_kex;
4664 const struct ssh_kex *preferred_kex[KEX_MAX];
4665 int n_preferred_ciphers;
4666 const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
4667 const struct ssh_compress *preferred_comp;
4668 int got_session_id, activated_authconn;
4669 struct Packet *pktout;
4671 crState(do_ssh2_transport_state);
4673 crBegin(ssh->do_ssh2_transport_crstate);
4675 s->cscipher_tobe = s->sccipher_tobe = NULL;
4676 s->csmac_tobe = s->scmac_tobe = NULL;
4677 s->cscomp_tobe = s->sccomp_tobe = NULL;
4679 s->got_session_id = s->activated_authconn = FALSE;
4682 * Be prepared to work around the buggy MAC problem.
4684 if (ssh->remote_bugs & BUG_SSH2_HMAC)
4685 s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
4687 s->maclist = macs, s->nmacs = lenof(macs);
4690 ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
4692 int i, j, commalist_started;
4695 * Set up the preferred key exchange. (NULL => warn below here)
4697 s->n_preferred_kex = 0;
4698 for (i = 0; i < KEX_MAX; i++) {
4699 switch (ssh->cfg.ssh_kexlist[i]) {
4701 s->preferred_kex[s->n_preferred_kex++] =
4702 &ssh_diffiehellman_gex;
4705 s->preferred_kex[s->n_preferred_kex++] =
4706 &ssh_diffiehellman_group14;
4709 s->preferred_kex[s->n_preferred_kex++] =
4710 &ssh_diffiehellman_group1;
4713 /* Flag for later. Don't bother if it's the last in
4715 if (i < KEX_MAX - 1) {
4716 s->preferred_kex[s->n_preferred_kex++] = NULL;
4723 * Set up the preferred ciphers. (NULL => warn below here)
4725 s->n_preferred_ciphers = 0;
4726 for (i = 0; i < CIPHER_MAX; i++) {
4727 switch (ssh->cfg.ssh_cipherlist[i]) {
4728 case CIPHER_BLOWFISH:
4729 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_blowfish;
4732 if (ssh->cfg.ssh2_des_cbc) {
4733 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_des;
4737 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_3des;
4740 s->preferred_ciphers[s->n_preferred_ciphers++] = &ssh2_aes;
4743 /* Flag for later. Don't bother if it's the last in
4745 if (i < CIPHER_MAX - 1) {
4746 s->preferred_ciphers[s->n_preferred_ciphers++] = NULL;
4753 * Set up preferred compression.
4755 if (ssh->cfg.compression)
4756 s->preferred_comp = &ssh_zlib;
4758 s->preferred_comp = &ssh_comp_none;
4761 * Enable queueing of outgoing auth- or connection-layer
4762 * packets while we are in the middle of a key exchange.
4764 ssh->queueing = TRUE;
4767 * Flag that KEX is in progress.
4769 ssh->kex_in_progress = TRUE;
4772 * Construct and send our key exchange packet.
4774 s->pktout = ssh2_pkt_init(SSH2_MSG_KEXINIT);
4775 for (i = 0; i < 16; i++)
4776 ssh2_pkt_addbyte(s->pktout, (unsigned char) random_byte());
4777 /* List key exchange algorithms. */
4778 ssh2_pkt_addstring_start(s->pktout);
4779 commalist_started = 0;
4780 for (i = 0; i < s->n_preferred_kex; i++) {
4781 const struct ssh_kex *k = s->preferred_kex[i];
4782 if (!k) continue; /* warning flag */
4783 if (commalist_started)
4784 ssh2_pkt_addstring_str(s->pktout, ",");
4785 ssh2_pkt_addstring_str(s->pktout, s->preferred_kex[i]->name);
4786 commalist_started = 1;
4788 /* List server host key algorithms. */
4789 ssh2_pkt_addstring_start(s->pktout);
4790 for (i = 0; i < lenof(hostkey_algs); i++) {
4791 ssh2_pkt_addstring_str(s->pktout, hostkey_algs[i]->name);
4792 if (i < lenof(hostkey_algs) - 1)
4793 ssh2_pkt_addstring_str(s->pktout, ",");
4795 /* List client->server encryption algorithms. */
4796 ssh2_pkt_addstring_start(s->pktout);
4797 commalist_started = 0;
4798 for (i = 0; i < s->n_preferred_ciphers; i++) {
4799 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4800 if (!c) continue; /* warning flag */
4801 for (j = 0; j < c->nciphers; j++) {
4802 if (commalist_started)
4803 ssh2_pkt_addstring_str(s->pktout, ",");
4804 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4805 commalist_started = 1;
4808 /* List server->client encryption algorithms. */
4809 ssh2_pkt_addstring_start(s->pktout);
4810 commalist_started = 0;
4811 for (i = 0; i < s->n_preferred_ciphers; i++) {
4812 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4813 if (!c) continue; /* warning flag */
4814 for (j = 0; j < c->nciphers; j++) {
4815 if (commalist_started)
4816 ssh2_pkt_addstring_str(s->pktout, ",");
4817 ssh2_pkt_addstring_str(s->pktout, c->list[j]->name);
4818 commalist_started = 1;
4821 /* List client->server MAC algorithms. */
4822 ssh2_pkt_addstring_start(s->pktout);
4823 for (i = 0; i < s->nmacs; i++) {
4824 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4825 if (i < s->nmacs - 1)
4826 ssh2_pkt_addstring_str(s->pktout, ",");
4828 /* List server->client MAC algorithms. */
4829 ssh2_pkt_addstring_start(s->pktout);
4830 for (i = 0; i < s->nmacs; i++) {
4831 ssh2_pkt_addstring_str(s->pktout, s->maclist[i]->name);
4832 if (i < s->nmacs - 1)
4833 ssh2_pkt_addstring_str(s->pktout, ",");
4835 /* List client->server compression algorithms. */
4836 ssh2_pkt_addstring_start(s->pktout);
4837 assert(lenof(compressions) > 1);
4838 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4839 for (i = 0; i < lenof(compressions); i++) {
4840 const struct ssh_compress *c = compressions[i];
4841 if (c != s->preferred_comp) {
4842 ssh2_pkt_addstring_str(s->pktout, ",");
4843 ssh2_pkt_addstring_str(s->pktout, c->name);
4846 /* List server->client compression algorithms. */
4847 ssh2_pkt_addstring_start(s->pktout);
4848 assert(lenof(compressions) > 1);
4849 ssh2_pkt_addstring_str(s->pktout, s->preferred_comp->name);
4850 for (i = 0; i < lenof(compressions); i++) {
4851 const struct ssh_compress *c = compressions[i];
4852 if (c != s->preferred_comp) {
4853 ssh2_pkt_addstring_str(s->pktout, ",");
4854 ssh2_pkt_addstring_str(s->pktout, c->name);
4857 /* List client->server languages. Empty list. */
4858 ssh2_pkt_addstring_start(s->pktout);
4859 /* List server->client languages. Empty list. */
4860 ssh2_pkt_addstring_start(s->pktout);
4861 /* First KEX packet does _not_ follow, because we're not that brave. */
4862 ssh2_pkt_addbool(s->pktout, FALSE);
4864 ssh2_pkt_adduint32(s->pktout, 0);
4867 ssh->exhash = ssh->exhashbase;
4868 sha_string(&ssh->exhash, s->pktout->data + 5, s->pktout->length - 5);
4870 ssh2_pkt_send_noqueue(ssh, s->pktout);
4874 if (pktin->length > 5)
4875 sha_string(&ssh->exhash, pktin->data + 5, pktin->length - 5);
4878 * Now examine the other side's KEXINIT to see what we're up
4885 if (pktin->type != SSH2_MSG_KEXINIT) {
4886 bombout(("expected key exchange packet from server"));
4890 ssh->hostkey = NULL;
4891 s->cscipher_tobe = NULL;
4892 s->sccipher_tobe = NULL;
4893 s->csmac_tobe = NULL;
4894 s->scmac_tobe = NULL;
4895 s->cscomp_tobe = NULL;
4896 s->sccomp_tobe = NULL;
4897 pktin->savedpos += 16; /* skip garbage cookie */
4898 ssh_pkt_getstring(pktin, &str, &len); /* key exchange algorithms */
4900 for (i = 0; i < s->n_preferred_kex; i++) {
4901 const struct ssh_kex *k = s->preferred_kex[i];
4904 } else if (in_commasep_string(k->name, str, len)) {
4909 sk_set_frozen(ssh->s, 1);
4910 askalg(ssh->frontend, "key-exchange algorithm",
4912 sk_set_frozen(ssh->s, 0);
4918 bombout(("Couldn't agree a key exchange algorithm (available: %s)",
4919 str ? str : "(null)"));
4922 ssh_pkt_getstring(pktin, &str, &len); /* host key algorithms */
4923 for (i = 0; i < lenof(hostkey_algs); i++) {
4924 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
4925 ssh->hostkey = hostkey_algs[i];
4929 ssh_pkt_getstring(pktin, &str, &len); /* client->server cipher */
4931 for (i = 0; i < s->n_preferred_ciphers; i++) {
4932 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4936 for (j = 0; j < c->nciphers; j++) {
4937 if (in_commasep_string(c->list[j]->name, str, len)) {
4938 s->cscipher_tobe = c->list[j];
4943 if (s->cscipher_tobe) {
4945 sk_set_frozen(ssh->s, 1);
4946 askalg(ssh->frontend, "client-to-server cipher",
4947 s->cscipher_tobe->name);
4948 sk_set_frozen(ssh->s, 0);
4953 if (!s->cscipher_tobe) {
4954 bombout(("Couldn't agree a client-to-server cipher (available: %s)",
4955 str ? str : "(null)"));
4959 ssh_pkt_getstring(pktin, &str, &len); /* server->client cipher */
4961 for (i = 0; i < s->n_preferred_ciphers; i++) {
4962 const struct ssh2_ciphers *c = s->preferred_ciphers[i];
4966 for (j = 0; j < c->nciphers; j++) {
4967 if (in_commasep_string(c->list[j]->name, str, len)) {
4968 s->sccipher_tobe = c->list[j];
4973 if (s->sccipher_tobe) {
4975 sk_set_frozen(ssh->s, 1);
4976 askalg(ssh->frontend, "server-to-client cipher",
4977 s->sccipher_tobe->name);
4978 sk_set_frozen(ssh->s, 0);
4983 if (!s->sccipher_tobe) {
4984 bombout(("Couldn't agree a server-to-client cipher (available: %s)",
4985 str ? str : "(null)"));
4989 ssh_pkt_getstring(pktin, &str, &len); /* client->server mac */
4990 for (i = 0; i < s->nmacs; i++) {
4991 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4992 s->csmac_tobe = s->maclist[i];
4996 ssh_pkt_getstring(pktin, &str, &len); /* server->client mac */
4997 for (i = 0; i < s->nmacs; i++) {
4998 if (in_commasep_string(s->maclist[i]->name, str, len)) {
4999 s->scmac_tobe = s->maclist[i];
5003 ssh_pkt_getstring(pktin, &str, &len); /* client->server compression */
5004 for (i = 0; i < lenof(compressions) + 1; i++) {
5005 const struct ssh_compress *c =
5006 i == 0 ? s->preferred_comp : compressions[i - 1];
5007 if (in_commasep_string(c->name, str, len)) {
5012 ssh_pkt_getstring(pktin, &str, &len); /* server->client compression */
5013 for (i = 0; i < lenof(compressions) + 1; i++) {
5014 const struct ssh_compress *c =
5015 i == 0 ? s->preferred_comp : compressions[i - 1];
5016 if (in_commasep_string(c->name, str, len)) {
5024 * Work out the number of bits of key we will need from the key
5025 * exchange. We start with the maximum key length of either
5031 csbits = s->cscipher_tobe->keylen;
5032 scbits = s->sccipher_tobe->keylen;
5033 s->nbits = (csbits > scbits ? csbits : scbits);
5035 /* The keys only have 160-bit entropy, since they're based on
5036 * a SHA-1 hash. So cap the key size at 160 bits. */
5041 * If we're doing Diffie-Hellman group exchange, start by
5042 * requesting a group.
5044 if (!ssh->kex->pdata) {
5045 logevent("Doing Diffie-Hellman group exchange");
5046 ssh->pkt_ctx |= SSH2_PKTCTX_DHGEX;
5048 * Work out how big a DH group we will need to allow that
5051 s->pbits = 512 << ((s->nbits - 1) / 64);
5052 s->pktout = ssh2_pkt_init(SSH2_MSG_KEX_DH_GEX_REQUEST);
5053 ssh2_pkt_adduint32(s->pktout, s->pbits);
5054 ssh2_pkt_send_noqueue(ssh, s->pktout);
5057 if (pktin->type != SSH2_MSG_KEX_DH_GEX_GROUP) {
5058 bombout(("expected key exchange group packet from server"));
5061 s->p = ssh2_pkt_getmp(pktin);
5062 s->g = ssh2_pkt_getmp(pktin);
5063 if (!s->p || !s->g) {
5064 bombout(("unable to read mp-ints from incoming group packet"));
5067 ssh->kex_ctx = dh_setup_gex(s->p, s->g);
5068 s->kex_init_value = SSH2_MSG_KEX_DH_GEX_INIT;
5069 s->kex_reply_value = SSH2_MSG_KEX_DH_GEX_REPLY;
5071 ssh->pkt_ctx |= SSH2_PKTCTX_DHGROUP;
5072 ssh->kex_ctx = dh_setup_group(ssh->kex);
5073 s->kex_init_value = SSH2_MSG_KEXDH_INIT;
5074 s->kex_reply_value = SSH2_MSG_KEXDH_REPLY;
5075 logeventf(ssh, "Using Diffie-Hellman with standard group \"%s\"",
5076 ssh->kex->groupname);
5079 logevent("Doing Diffie-Hellman key exchange");
5081 * Now generate and send e for Diffie-Hellman.
5083 s->e = dh_create_e(ssh->kex_ctx, s->nbits * 2);
5084 s->pktout = ssh2_pkt_init(s->kex_init_value);
5085 ssh2_pkt_addmp(s->pktout, s->e);
5086 ssh2_pkt_send_noqueue(ssh, s->pktout);
5089 if (pktin->type != s->kex_reply_value) {
5090 bombout(("expected key exchange reply packet from server"));
5093 ssh_pkt_getstring(pktin, &s->hostkeydata, &s->hostkeylen);
5094 s->f = ssh2_pkt_getmp(pktin);
5096 bombout(("unable to parse key exchange reply packet"));
5099 ssh_pkt_getstring(pktin, &s->sigdata, &s->siglen);
5101 s->K = dh_find_K(ssh->kex_ctx, s->f);
5103 sha_string(&ssh->exhash, s->hostkeydata, s->hostkeylen);
5104 if (ssh->kex == &ssh_diffiehellman_gex) {
5105 sha_uint32(&ssh->exhash, s->pbits);
5106 sha_mpint(&ssh->exhash, s->p);
5107 sha_mpint(&ssh->exhash, s->g);
5109 sha_mpint(&ssh->exhash, s->e);
5110 sha_mpint(&ssh->exhash, s->f);
5111 sha_mpint(&ssh->exhash, s->K);
5112 SHA_Final(&ssh->exhash, s->exchange_hash);
5114 dh_cleanup(ssh->kex_ctx);
5115 ssh->kex_ctx = NULL;
5118 debug(("Exchange hash is:\n"));
5119 dmemdump(s->exchange_hash, 20);
5122 s->hkey = ssh->hostkey->newkey(s->hostkeydata, s->hostkeylen);
5124 !ssh->hostkey->verifysig(s->hkey, s->sigdata, s->siglen,
5125 (char *)s->exchange_hash, 20)) {
5126 bombout(("Server's host key did not match the signature supplied"));
5131 * Authenticate remote host: verify host key. (We've already
5132 * checked the signature of the exchange hash.)
5134 s->keystr = ssh->hostkey->fmtkey(s->hkey);
5135 s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
5136 sk_set_frozen(ssh->s, 1);
5137 verify_ssh_host_key(ssh->frontend,
5138 ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
5139 s->keystr, s->fingerprint);
5140 sk_set_frozen(ssh->s, 0);
5141 if (!s->got_session_id) { /* don't bother logging this in rekeys */
5142 logevent("Host key fingerprint is:");
5143 logevent(s->fingerprint);
5145 sfree(s->fingerprint);
5147 ssh->hostkey->freekey(s->hkey);
5150 * The exchange hash from the very first key exchange is also
5151 * the session id, used in session key construction and
5154 if (!s->got_session_id) {
5155 memcpy(ssh->v2_session_id, s->exchange_hash,
5156 sizeof(s->exchange_hash));
5157 s->got_session_id = TRUE;
5161 * Send SSH2_MSG_NEWKEYS.
5163 s->pktout = ssh2_pkt_init(SSH2_MSG_NEWKEYS);
5164 ssh2_pkt_send_noqueue(ssh, s->pktout);
5165 ssh->outgoing_data_size = 0; /* start counting from here */
5168 * We've sent client NEWKEYS, so create and initialise
5169 * client-to-server session keys.
5171 if (ssh->cs_cipher_ctx)
5172 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
5173 ssh->cscipher = s->cscipher_tobe;
5174 ssh->cs_cipher_ctx = ssh->cscipher->make_context();
5176 if (ssh->cs_mac_ctx)
5177 ssh->csmac->free_context(ssh->cs_mac_ctx);
5178 ssh->csmac = s->csmac_tobe;
5179 ssh->cs_mac_ctx = ssh->csmac->make_context();
5181 if (ssh->cs_comp_ctx)
5182 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
5183 ssh->cscomp = s->cscomp_tobe;
5184 ssh->cs_comp_ctx = ssh->cscomp->compress_init();
5187 * Set IVs on client-to-server keys. Here we use the exchange
5188 * hash from the _first_ key exchange.
5191 unsigned char keyspace[40];
5192 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'C',keyspace);
5193 ssh->cscipher->setkey(ssh->cs_cipher_ctx, keyspace);
5194 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'A',keyspace);
5195 ssh->cscipher->setiv(ssh->cs_cipher_ctx, keyspace);
5196 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'E',keyspace);
5197 ssh->csmac->setkey(ssh->cs_mac_ctx, keyspace);
5200 logeventf(ssh, "Initialised %.200s client->server encryption",
5201 ssh->cscipher->text_name);
5202 logeventf(ssh, "Initialised %.200s client->server MAC algorithm",
5203 ssh->csmac->text_name);
5204 if (ssh->cscomp->text_name)
5205 logeventf(ssh, "Initialised %s compression",
5206 ssh->cscomp->text_name);
5209 * Now our end of the key exchange is complete, we can send all
5210 * our queued higher-layer packets.
5212 ssh->queueing = FALSE;
5213 ssh2_pkt_queuesend(ssh);
5216 * Expect SSH2_MSG_NEWKEYS from server.
5219 if (pktin->type != SSH2_MSG_NEWKEYS) {
5220 bombout(("expected new-keys packet from server"));
5223 ssh->incoming_data_size = 0; /* start counting from here */
5226 * We've seen server NEWKEYS, so create and initialise
5227 * server-to-client session keys.
5229 if (ssh->sc_cipher_ctx)
5230 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
5231 ssh->sccipher = s->sccipher_tobe;
5232 ssh->sc_cipher_ctx = ssh->sccipher->make_context();
5234 if (ssh->sc_mac_ctx)
5235 ssh->scmac->free_context(ssh->sc_mac_ctx);
5236 ssh->scmac = s->scmac_tobe;
5237 ssh->sc_mac_ctx = ssh->scmac->make_context();
5239 if (ssh->sc_comp_ctx)
5240 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
5241 ssh->sccomp = s->sccomp_tobe;
5242 ssh->sc_comp_ctx = ssh->sccomp->decompress_init();
5245 * Set IVs on server-to-client keys. Here we use the exchange
5246 * hash from the _first_ key exchange.
5249 unsigned char keyspace[40];
5250 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'D',keyspace);
5251 ssh->sccipher->setkey(ssh->sc_cipher_ctx, keyspace);
5252 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'B',keyspace);
5253 ssh->sccipher->setiv(ssh->sc_cipher_ctx, keyspace);
5254 ssh2_mkkey(ssh,s->K,s->exchange_hash,ssh->v2_session_id,'F',keyspace);
5255 ssh->scmac->setkey(ssh->sc_mac_ctx, keyspace);
5257 logeventf(ssh, "Initialised %.200s server->client encryption",
5258 ssh->sccipher->text_name);
5259 logeventf(ssh, "Initialised %.200s server->client MAC algorithm",
5260 ssh->scmac->text_name);
5261 if (ssh->sccomp->text_name)
5262 logeventf(ssh, "Initialised %s decompression",
5263 ssh->sccomp->text_name);
5266 * Free key exchange data.
5270 if (ssh->kex == &ssh_diffiehellman_gex) {
5276 * Key exchange is over. Loop straight back round if we have a
5277 * deferred rekey reason.
5279 if (ssh->deferred_rekey_reason) {
5280 logevent(ssh->deferred_rekey_reason);
5282 ssh->deferred_rekey_reason = NULL;
5283 goto begin_key_exchange;
5287 * Otherwise, schedule a timer for our next rekey.
5289 ssh->kex_in_progress = FALSE;
5290 ssh->last_rekey = GETTICKCOUNT();
5291 if (ssh->cfg.ssh_rekey_time != 0)
5292 ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5296 * If this is the first key exchange phase, we must pass the
5297 * SSH2_MSG_NEWKEYS packet to the next layer, not because it
5298 * wants to see it but because it will need time to initialise
5299 * itself before it sees an actual packet. In subsequent key
5300 * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
5301 * it would only confuse the layer above.
5303 if (s->activated_authconn) {
5306 s->activated_authconn = TRUE;
5309 * Now we're encrypting. Begin returning 1 to the protocol main
5310 * function so that other things can run on top of the
5311 * transport. If we ever see a KEXINIT, we must go back to the
5314 * We _also_ go back to the start if we see pktin==NULL and
5315 * inlen==-1, because this is a special signal meaning
5316 * `initiate client-driven rekey', and `in' contains a message
5317 * giving the reason for the rekey.
5319 while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
5320 (!pktin && inlen == -1))) {
5325 logevent("Server initiated key re-exchange");
5328 * Special case: if the server bug is set that doesn't
5329 * allow rekeying, we give a different log message and
5330 * continue waiting. (If such a server _initiates_ a rekey,
5331 * we process it anyway!)
5333 if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
5334 logeventf(ssh, "Server bug prevents key re-exchange (%s)",
5336 /* Reset the counters, so that at least this message doesn't
5337 * hit the event log _too_ often. */
5338 ssh->outgoing_data_size = 0;
5339 ssh->incoming_data_size = 0;
5340 if (ssh->cfg.ssh_rekey_time != 0) {
5342 schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
5345 goto wait_for_rekey; /* this is utterly horrid */
5347 logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
5350 goto begin_key_exchange;
5356 * Add data to an SSH2 channel output buffer.
5358 static void ssh2_add_channel_data(struct ssh_channel *c, char *buf,
5361 bufchain_add(&c->v.v2.outbuffer, buf, len);
5365 * Attempt to send data on an SSH2 channel.
5367 static int ssh2_try_send(struct ssh_channel *c)
5370 struct Packet *pktout;
5372 while (c->v.v2.remwindow > 0 && bufchain_size(&c->v.v2.outbuffer) > 0) {
5375 bufchain_prefix(&c->v.v2.outbuffer, &data, &len);
5376 if ((unsigned)len > c->v.v2.remwindow)
5377 len = c->v.v2.remwindow;
5378 if ((unsigned)len > c->v.v2.remmaxpkt)
5379 len = c->v.v2.remmaxpkt;
5380 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
5381 ssh2_pkt_adduint32(pktout, c->remoteid);
5382 dont_log_data(ssh, pktout, PKTLOG_OMIT);
5383 ssh2_pkt_addstring_start(pktout);
5384 ssh2_pkt_addstring_data(pktout, data, len);
5385 end_log_omission(ssh, pktout);
5386 ssh2_pkt_send(ssh, pktout);
5387 bufchain_consume(&c->v.v2.outbuffer, len);
5388 c->v.v2.remwindow -= len;
5392 * After having sent as much data as we can, return the amount
5395 return bufchain_size(&c->v.v2.outbuffer);
5399 * Potentially enlarge the window on an SSH2 channel.
5401 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
5406 * Never send WINDOW_ADJUST for a channel that the remote side
5407 * already thinks it's closed; there's no point, since it won't
5408 * be sending any more data anyway.
5413 if (newwin > c->v.v2.locwindow) {
5414 struct Packet *pktout;
5416 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
5417 ssh2_pkt_adduint32(pktout, c->remoteid);
5418 ssh2_pkt_adduint32(pktout, newwin - c->v.v2.locwindow);
5419 ssh2_pkt_send(ssh, pktout);
5420 c->v.v2.locwindow = newwin;
5424 static void ssh2_msg_channel_window_adjust(Ssh ssh, struct Packet *pktin)
5426 unsigned i = ssh_pkt_getuint32(pktin);
5427 struct ssh_channel *c;
5428 c = find234(ssh->channels, &i, ssh_channelfind);
5429 if (c && !c->closes)
5430 c->v.v2.remwindow += ssh_pkt_getuint32(pktin);
5433 static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
5436 unsigned int length;
5437 unsigned i = ssh_pkt_getuint32(pktin);
5438 struct ssh_channel *c;
5439 c = find234(ssh->channels, &i, ssh_channelfind);
5441 return; /* nonexistent channel */
5442 if (pktin->type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
5443 ssh_pkt_getuint32(pktin) != SSH2_EXTENDED_DATA_STDERR)
5444 return; /* extended but not stderr */
5445 ssh_pkt_getstring(pktin, &data, &length);
5448 c->v.v2.locwindow -= length;
5450 case CHAN_MAINSESSION:
5452 from_backend(ssh->frontend, pktin->type ==
5453 SSH2_MSG_CHANNEL_EXTENDED_DATA,
5457 bufsize = x11_send(c->u.x11.s, data, length);
5460 bufsize = pfd_send(c->u.pfd.s, data, length);
5463 while (length > 0) {
5464 if (c->u.a.lensofar < 4) {
5465 unsigned int l = min(4 - c->u.a.lensofar, length);
5466 memcpy(c->u.a.msglen + c->u.a.lensofar,
5470 c->u.a.lensofar += l;
5472 if (c->u.a.lensofar == 4) {
5474 4 + GET_32BIT(c->u.a.msglen);
5475 c->u.a.message = snewn(c->u.a.totallen,
5477 memcpy(c->u.a.message, c->u.a.msglen, 4);
5479 if (c->u.a.lensofar >= 4 && length > 0) {
5481 min(c->u.a.totallen - c->u.a.lensofar,
5483 memcpy(c->u.a.message + c->u.a.lensofar,
5487 c->u.a.lensofar += l;
5489 if (c->u.a.lensofar == c->u.a.totallen) {
5492 if (agent_query(c->u.a.message,
5495 ssh_agentf_callback, c))
5496 ssh_agentf_callback(c, reply, replylen);
5497 sfree(c->u.a.message);
5498 c->u.a.lensofar = 0;
5505 * If we are not buffering too much data,
5506 * enlarge the window again at the remote side.
5508 if (bufsize < OUR_V2_WINSIZE)
5509 ssh2_set_window(c, OUR_V2_WINSIZE - bufsize);
5513 static void ssh2_msg_channel_eof(Ssh ssh, struct Packet *pktin)
5515 unsigned i = ssh_pkt_getuint32(pktin);
5516 struct ssh_channel *c;
5518 c = find234(ssh->channels, &i, ssh_channelfind);
5520 return; /* nonexistent channel */
5522 if (c->type == CHAN_X11) {
5524 * Remote EOF on an X11 channel means we should
5525 * wrap up and close the channel ourselves.
5527 x11_close(c->u.x11.s);
5529 } else if (c->type == CHAN_AGENT) {
5531 } else if (c->type == CHAN_SOCKDATA) {
5532 pfd_close(c->u.pfd.s);
5537 static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
5539 unsigned i = ssh_pkt_getuint32(pktin);
5540 struct ssh_channel *c;
5541 struct Packet *pktout;
5543 c = find234(ssh->channels, &i, ssh_channelfind);
5544 if (!c || ((int)c->remoteid) == -1) {
5545 bombout(("Received CHANNEL_CLOSE for %s channel %d\n",
5546 c ? "half-open" : "nonexistent", i));
5549 /* Do pre-close processing on the channel. */
5551 case CHAN_MAINSESSION:
5552 ssh->mainchan = NULL;
5553 update_specials_menu(ssh->frontend);
5556 if (c->u.x11.s != NULL)
5557 x11_close(c->u.x11.s);
5564 if (c->u.pfd.s != NULL)
5565 pfd_close(c->u.pfd.s);
5569 if (c->closes == 0) {
5570 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5571 ssh2_pkt_adduint32(pktout, c->remoteid);
5572 ssh2_pkt_send(ssh, pktout);
5574 del234(ssh->channels, c);
5575 bufchain_clear(&c->v.v2.outbuffer);
5579 * See if that was the last channel left open.
5580 * (This is only our termination condition if we're
5581 * not running in -N mode.)
5583 if (!ssh->cfg.ssh_no_shell && count234(ssh->channels) == 0) {
5584 logevent("All channels closed. Disconnecting");
5587 * We used to send SSH_MSG_DISCONNECT here,
5588 * because I'd believed that _every_ conforming
5589 * SSH2 connection had to end with a disconnect
5590 * being sent by at least one side; apparently
5591 * I was wrong and it's perfectly OK to
5592 * unceremoniously slam the connection shut
5593 * when you're done, and indeed OpenSSH feels
5594 * this is more polite than sending a
5595 * DISCONNECT. So now we don't.
5597 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5598 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
5599 ssh2_pkt_addstring(s->pktout, "All open channels closed");
5600 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
5601 ssh2_pkt_send_noqueue(ssh, s->pktout);
5603 ssh_closing((Plug)ssh, NULL, 0, 0);
5607 static void ssh2_msg_channel_open_confirmation(Ssh ssh, struct Packet *pktin)
5609 unsigned i = ssh_pkt_getuint32(pktin);
5610 struct ssh_channel *c;
5611 struct Packet *pktout;
5613 c = find234(ssh->channels, &i, ssh_channelfind);
5615 return; /* nonexistent channel */
5616 if (c->type != CHAN_SOCKDATA_DORMANT)
5617 return; /* dunno why they're confirming this */
5618 c->remoteid = ssh_pkt_getuint32(pktin);
5619 c->type = CHAN_SOCKDATA;
5620 c->v.v2.remwindow = ssh_pkt_getuint32(pktin);
5621 c->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
5623 pfd_confirm(c->u.pfd.s);
5626 * We have a pending close on this channel,
5627 * which we decided on before the server acked
5628 * the channel open. So now we know the
5629 * remoteid, we can close it again.
5631 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
5632 ssh2_pkt_adduint32(pktout, c->remoteid);
5633 ssh2_pkt_send(ssh, pktout);
5637 static void ssh2_msg_channel_open_failure(Ssh ssh, struct Packet *pktin)
5639 static const char *const reasons[] = {
5640 "<unknown reason code>",
5641 "Administratively prohibited",
5643 "Unknown channel type",
5644 "Resource shortage",
5646 unsigned i = ssh_pkt_getuint32(pktin);
5647 unsigned reason_code;
5648 char *reason_string;
5651 struct ssh_channel *c;
5652 c = find234(ssh->channels, &i, ssh_channelfind);
5654 return; /* nonexistent channel */
5655 if (c->type != CHAN_SOCKDATA_DORMANT)
5656 return; /* dunno why they're failing this */
5658 reason_code = ssh_pkt_getuint32(pktin);
5659 if (reason_code >= lenof(reasons))
5660 reason_code = 0; /* ensure reasons[reason_code] in range */
5661 ssh_pkt_getstring(pktin, &reason_string, &reason_length);
5662 message = dupprintf("Forwarded connection refused by"
5663 " server: %s [%.*s]", reasons[reason_code],
5664 reason_length, reason_string);
5668 pfd_close(c->u.pfd.s);
5670 del234(ssh->channels, c);
5674 static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
5678 int typelen, want_reply;
5679 int reply = SSH2_MSG_CHANNEL_FAILURE; /* default */
5680 struct ssh_channel *c;
5681 struct Packet *pktout;
5683 localid = ssh_pkt_getuint32(pktin);
5684 ssh_pkt_getstring(pktin, &type, &typelen);
5685 want_reply = ssh2_pkt_getbool(pktin);
5688 * First, check that the channel exists. Otherwise,
5689 * we can instantly disconnect with a rude message.
5691 c = find234(ssh->channels, &localid, ssh_channelfind);
5694 sprintf(buf, "Received channel request for nonexistent"
5695 " channel %d", localid);
5697 pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
5698 ssh2_pkt_adduint32(pktout, SSH2_DISCONNECT_BY_APPLICATION);
5699 ssh2_pkt_addstring(pktout, buf);
5700 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5701 ssh2_pkt_send_noqueue(ssh, pktout);
5702 connection_fatal(ssh->frontend, "%s", buf);
5703 ssh_closing((Plug)ssh, NULL, 0, 0);
5708 * Having got the channel number, we now look at
5709 * the request type string to see if it's something
5712 if (c == ssh->mainchan) {
5714 * We recognise "exit-status" and "exit-signal" on
5715 * the primary channel.
5717 if (typelen == 11 &&
5718 !memcmp(type, "exit-status", 11)) {
5720 ssh->exitcode = ssh_pkt_getuint32(pktin);
5721 logeventf(ssh, "Server sent command exit status %d",
5723 reply = SSH2_MSG_CHANNEL_SUCCESS;
5725 } else if (typelen == 11 &&
5726 !memcmp(type, "exit-signal", 11)) {
5728 int is_plausible = TRUE, is_int = FALSE;
5729 char *fmt_sig = "", *fmt_msg = "";
5731 int msglen = 0, core = FALSE;
5732 /* ICK: older versions of OpenSSH (e.g. 3.4p1)
5733 * provide an `int' for the signal, despite its
5734 * having been a `string' in the drafts since at
5735 * least 2001. (Fixed in session.c 1.147.) Try to
5736 * infer which we can safely parse it as. */
5738 unsigned char *p = pktin->body +
5740 long len = pktin->length - pktin->savedpos;
5741 unsigned long num = GET_32BIT(p); /* what is it? */
5742 /* If it's 0, it hardly matters; assume string */
5746 int maybe_int = FALSE, maybe_str = FALSE;
5747 #define CHECK_HYPOTHESIS(offset, result) \
5750 if (q >= 0 && q+4 <= len) { \
5751 q = q + 4 + GET_32BIT(p+q); \
5752 if (q >= 0 && q+4 <= len && \
5753 (q = q + 4 + GET_32BIT(p+q)) && q == len) \
5757 CHECK_HYPOTHESIS(4+1, maybe_int);
5758 CHECK_HYPOTHESIS(4+num+1, maybe_str);
5759 #undef CHECK_HYPOTHESIS
5760 if (maybe_int && !maybe_str)
5762 else if (!maybe_int && maybe_str)
5765 /* Crikey. Either or neither. Panic. */
5766 is_plausible = FALSE;
5771 /* Old non-standard OpenSSH. */
5772 int signum = ssh_pkt_getuint32(pktin);
5773 fmt_sig = dupprintf(" %d", signum);
5775 /* As per the drafts. */
5778 ssh_pkt_getstring(pktin, &sig, &siglen);
5779 /* Signal name isn't supposed to be blank, but
5780 * let's cope gracefully if it is. */
5782 fmt_sig = dupprintf(" \"%.*s\"",
5786 core = ssh2_pkt_getbool(pktin);
5787 ssh_pkt_getstring(pktin, &msg, &msglen);
5789 fmt_msg = dupprintf(" (\"%.*s\")", msglen, msg);
5791 /* ignore lang tag */
5792 } /* else don't attempt to parse */
5793 logeventf(ssh, "Server exited on signal%s%s%s",
5794 fmt_sig, core ? " (core dumped)" : "",
5796 if (*fmt_sig) sfree(fmt_sig);
5797 if (*fmt_msg) sfree(fmt_msg);
5798 reply = SSH2_MSG_CHANNEL_SUCCESS;
5803 * This is a channel request we don't know
5804 * about, so we now either ignore the request
5805 * or respond with CHANNEL_FAILURE, depending
5808 reply = SSH2_MSG_CHANNEL_FAILURE;
5811 pktout = ssh2_pkt_init(reply);
5812 ssh2_pkt_adduint32(pktout, c->remoteid);
5813 ssh2_pkt_send(ssh, pktout);
5817 static void ssh2_msg_global_request(Ssh ssh, struct Packet *pktin)
5820 int typelen, want_reply;
5821 struct Packet *pktout;
5823 ssh_pkt_getstring(pktin, &type, &typelen);
5824 want_reply = ssh2_pkt_getbool(pktin);
5827 * We currently don't support any global requests
5828 * at all, so we either ignore the request or
5829 * respond with REQUEST_FAILURE, depending on
5833 pktout = ssh2_pkt_init(SSH2_MSG_REQUEST_FAILURE);
5834 ssh2_pkt_send(ssh, pktout);
5838 static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
5846 struct ssh_channel *c;
5847 unsigned remid, winsize, pktsize;
5848 struct Packet *pktout;
5850 ssh_pkt_getstring(pktin, &type, &typelen);
5851 c = snew(struct ssh_channel);
5854 remid = ssh_pkt_getuint32(pktin);
5855 winsize = ssh_pkt_getuint32(pktin);
5856 pktsize = ssh_pkt_getuint32(pktin);
5858 if (typelen == 3 && !memcmp(type, "x11", 3)) {
5861 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5862 addrstr = snewn(peeraddrlen+1, char);
5863 memcpy(addrstr, peeraddr, peeraddrlen);
5864 addrstr[peeraddrlen] = '\0';
5865 peerport = ssh_pkt_getuint32(pktin);
5867 logeventf(ssh, "Received X11 connect request from %s:%d",
5870 if (!ssh->X11_fwd_enabled)
5871 error = "X11 forwarding is not enabled";
5872 else if (x11_init(&c->u.x11.s, ssh->cfg.x11_display, c,
5873 ssh->x11auth, addrstr, peerport,
5874 &ssh->cfg) != NULL) {
5875 error = "Unable to open an X11 connection";
5877 logevent("Opening X11 forward connection succeeded");
5882 } else if (typelen == 15 &&
5883 !memcmp(type, "forwarded-tcpip", 15)) {
5884 struct ssh_rportfwd pf, *realpf;
5887 ssh_pkt_getstring(pktin, &dummy, &dummylen);/* skip address */
5888 pf.sport = ssh_pkt_getuint32(pktin);
5889 ssh_pkt_getstring(pktin, &peeraddr, &peeraddrlen);
5890 peerport = ssh_pkt_getuint32(pktin);
5891 realpf = find234(ssh->rportfwds, &pf, NULL);
5892 logeventf(ssh, "Received remote port %d open request "
5893 "from %s:%d", pf.sport, peeraddr, peerport);
5894 if (realpf == NULL) {
5895 error = "Remote port is not recognised";
5897 const char *e = pfd_newconnect(&c->u.pfd.s,
5901 realpf->pfrec->addressfamily);
5902 logeventf(ssh, "Attempting to forward remote port to "
5903 "%s:%d", realpf->dhost, realpf->dport);
5905 logeventf(ssh, "Port open failed: %s", e);
5906 error = "Port open failed";
5908 logevent("Forwarded port opened successfully");
5909 c->type = CHAN_SOCKDATA;
5912 } else if (typelen == 22 &&
5913 !memcmp(type, "auth-agent@openssh.com", 3)) {
5914 if (!ssh->agentfwd_enabled)
5915 error = "Agent forwarding is not enabled";
5917 c->type = CHAN_AGENT; /* identify channel type */
5918 c->u.a.lensofar = 0;
5921 error = "Unsupported channel type requested";
5924 c->remoteid = remid;
5926 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_FAILURE);
5927 ssh2_pkt_adduint32(pktout, c->remoteid);
5928 ssh2_pkt_adduint32(pktout, SSH2_OPEN_CONNECT_FAILED);
5929 ssh2_pkt_addstring(pktout, error);
5930 ssh2_pkt_addstring(pktout, "en"); /* language tag */
5931 ssh2_pkt_send(ssh, pktout);
5932 logeventf(ssh, "Rejected channel open: %s", error);
5935 c->localid = alloc_channel_id(ssh);
5937 c->v.v2.locwindow = OUR_V2_WINSIZE;
5938 c->v.v2.remwindow = winsize;
5939 c->v.v2.remmaxpkt = pktsize;
5940 bufchain_init(&c->v.v2.outbuffer);
5941 add234(ssh->channels, c);
5942 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
5943 ssh2_pkt_adduint32(pktout, c->remoteid);
5944 ssh2_pkt_adduint32(pktout, c->localid);
5945 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
5946 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
5947 ssh2_pkt_send(ssh, pktout);
5952 * Handle the SSH2 userauth and connection layers.
5954 static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
5955 struct Packet *pktin)
5957 struct do_ssh2_authconn_state {
5959 AUTH_INVALID, AUTH_PUBLICKEY_AGENT, AUTH_PUBLICKEY_FILE,
5961 AUTH_KEYBOARD_INTERACTIVE
5965 AUTH_TYPE_PUBLICKEY,
5966 AUTH_TYPE_PUBLICKEY_OFFER_LOUD,
5967 AUTH_TYPE_PUBLICKEY_OFFER_QUIET,
5969 AUTH_TYPE_KEYBOARD_INTERACTIVE,
5970 AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
5972 int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
5973 int tried_pubkey_config, tried_agent;
5974 int kbd_inter_running, kbd_inter_refused;
5976 int num_prompts, curr_prompt, echo;
5981 void *publickey_blob;
5982 int publickey_bloblen;
5983 unsigned char request[5], *response, *p;
5987 char *pkblob, *alg, *commentp;
5988 int pklen, alglen, commentlen;
5989 int siglen, retlen, len;
5990 char *q, *agentreq, *ret;
5992 int num_env, env_left, env_ok;
5993 struct Packet *pktout;
5995 crState(do_ssh2_authconn_state);
5997 crBegin(ssh->do_ssh2_authconn_crstate);
6000 * Request userauth protocol, and await a response to it.
6002 s->pktout = ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
6003 ssh2_pkt_addstring(s->pktout, "ssh-userauth");
6004 ssh2_pkt_send(ssh, s->pktout);
6005 crWaitUntilV(pktin);
6006 if (pktin->type != SSH2_MSG_SERVICE_ACCEPT) {
6007 bombout(("Server refused user authentication protocol"));
6012 * We repeat this whole loop, including the username prompt,
6013 * until we manage a successful authentication. If the user
6014 * types the wrong _password_, they can be sent back to the
6015 * beginning to try another username, if this is configured on.
6016 * (If they specify a username in the config, they are never
6017 * asked, even if they do give a wrong password.)
6019 * I think this best serves the needs of
6021 * - the people who have no configuration, no keys, and just
6022 * want to try repeated (username,password) pairs until they
6023 * type both correctly
6025 * - people who have keys and configuration but occasionally
6026 * need to fall back to passwords
6028 * - people with a key held in Pageant, who might not have
6029 * logged in to a particular machine before; so they want to
6030 * type a username, and then _either_ their key will be
6031 * accepted, _or_ they will type a password. If they mistype
6032 * the username they will want to be able to get back and
6035 s->username[0] = '\0';
6036 s->got_username = FALSE;
6041 if (s->got_username && !ssh->cfg.change_username) {
6043 * We got a username last time round this loop, and
6044 * with change_username turned off we don't try to get
6047 } else if (!*ssh->cfg.username) {
6048 if (ssh_get_line && !ssh_getline_pw_only) {
6049 if (!ssh_get_line("login as: ",
6050 s->username, sizeof(s->username), FALSE)) {
6052 * get_line failed to get a username.
6055 logevent("No username provided. Abandoning session.");
6056 ssh_closing((Plug)ssh, NULL, 0, 0);
6060 int ret; /* need not be saved across crReturn */
6061 c_write_str(ssh, "login as: ");
6063 setup_userpass_input(ssh, s->username, sizeof(s->username), 1);
6065 crWaitUntilV(!pktin);
6066 ret = process_userpass_input(ssh, in, inlen);
6070 c_write_str(ssh, "\r\n");
6072 s->username[strcspn(s->username, "\n\r")] = '\0';
6075 strncpy(s->username, ssh->cfg.username, sizeof(s->username));
6076 s->username[sizeof(s->username)-1] = '\0';
6077 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
6078 stuff = dupprintf("Using username \"%s\".\r\n", s->username);
6079 c_write_str(ssh, stuff);
6083 s->got_username = TRUE;
6086 * Send an authentication request using method "none": (a)
6087 * just in case it succeeds, and (b) so that we know what
6088 * authentication methods we can usefully try next.
6090 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6092 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6093 ssh2_pkt_addstring(s->pktout, s->username);
6094 ssh2_pkt_addstring(s->pktout, "ssh-connection");/* service requested */
6095 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6096 ssh2_pkt_send(ssh, s->pktout);
6097 s->type = AUTH_TYPE_NONE;
6099 s->we_are_in = FALSE;
6101 s->tried_pubkey_config = FALSE;
6102 s->tried_agent = FALSE;
6103 s->kbd_inter_running = FALSE;
6104 s->kbd_inter_refused = FALSE;
6105 /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
6106 if (!filename_is_null(ssh->cfg.keyfile)) {
6108 logeventf(ssh, "Reading private key file \"%.150s\"",
6109 filename_to_str(&ssh->cfg.keyfile));
6110 keytype = key_type(&ssh->cfg.keyfile);
6111 if (keytype == SSH_KEYTYPE_SSH2) {
6113 ssh2_userkey_loadpub(&ssh->cfg.keyfile, NULL,
6114 &s->publickey_bloblen, NULL);
6117 logeventf(ssh, "Unable to use this key file (%s)",
6118 key_type_to_str(keytype));
6119 msgbuf = dupprintf("Unable to use key file \"%.150s\""
6121 filename_to_str(&ssh->cfg.keyfile),
6122 key_type_to_str(keytype));
6123 c_write_str(ssh, msgbuf);
6125 s->publickey_blob = NULL;
6128 s->publickey_blob = NULL;
6132 * Wait for the result of the last authentication request.
6135 crWaitUntilV(pktin);
6136 while (pktin->type == SSH2_MSG_USERAUTH_BANNER) {
6140 * Don't show the banner if we're operating in
6141 * non-verbose non-interactive mode. (It's probably
6142 * a script, which means nobody will read the
6143 * banner _anyway_, and moreover the printing of
6144 * the banner will screw up processing on the
6145 * output of (say) plink.)
6147 if (flags & (FLAG_VERBOSE | FLAG_INTERACTIVE)) {
6148 ssh_pkt_getstring(pktin, &banner, &size);
6150 c_write_untrusted(ssh, banner, size);
6152 crWaitUntilV(pktin);
6154 if (pktin->type == SSH2_MSG_USERAUTH_SUCCESS) {
6155 logevent("Access granted");
6156 s->we_are_in = TRUE;
6160 if (s->kbd_inter_running &&
6161 pktin->type == SSH2_MSG_USERAUTH_INFO_REQUEST) {
6163 * This is either a further set-of-prompts packet
6164 * in keyboard-interactive authentication, or it's
6165 * the same one and we came back here with `gotit'
6166 * set. In the former case, we must reset the
6167 * curr_prompt variable.
6171 } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
6172 /* FIXME: perhaps we should support this? */
6173 bombout(("PASSWD_CHANGEREQ not yet supported"));
6175 } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
6176 bombout(("Strange packet received during authentication: type %d",
6184 * OK, we're now sitting on a USERAUTH_FAILURE message, so
6185 * we can look at the string in it and know what we can
6186 * helpfully try next.
6188 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE) {
6191 ssh_pkt_getstring(pktin, &methods, &methlen);
6192 s->kbd_inter_running = FALSE;
6193 if (!ssh2_pkt_getbool(pktin)) {
6195 * We have received an unequivocal Access
6196 * Denied. This can translate to a variety of
6199 * - if we'd just tried "none" authentication,
6200 * it's not worth printing anything at all
6202 * - if we'd just tried a public key _offer_,
6203 * the message should be "Server refused our
6204 * key" (or no message at all if the key
6205 * came from Pageant)
6207 * - if we'd just tried anything else, the
6208 * message really should be "Access denied".
6210 * Additionally, if we'd just tried password
6211 * authentication, we should break out of this
6212 * whole loop so as to go back to the username
6213 * prompt (iff we're configured to allow
6214 * username change attempts).
6216 if (s->type == AUTH_TYPE_NONE) {
6218 } else if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD ||
6219 s->type == AUTH_TYPE_PUBLICKEY_OFFER_QUIET) {
6220 if (s->type == AUTH_TYPE_PUBLICKEY_OFFER_LOUD)
6221 c_write_str(ssh, "Server refused our key\r\n");
6222 logevent("Server refused public key");
6223 } else if (s->type==AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET) {
6224 /* server declined keyboard-interactive; ignore */
6226 c_write_str(ssh, "Access denied\r\n");
6227 logevent("Access denied");
6228 if (s->type == AUTH_TYPE_PASSWORD &&
6229 ssh->cfg.change_username) {
6230 /* XXX perhaps we should allow
6231 * keyboard-interactive to do this too? */
6232 s->we_are_in = FALSE;
6237 c_write_str(ssh, "Further authentication required\r\n");
6238 logevent("Further authentication required");
6242 in_commasep_string("publickey", methods, methlen);
6244 in_commasep_string("password", methods, methlen);
6245 s->can_keyb_inter = ssh->cfg.try_ki_auth &&
6246 in_commasep_string("keyboard-interactive", methods, methlen);
6250 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6254 * Most password/passphrase prompts will be
6255 * non-echoing, so we set this to 0 by default.
6256 * Exception is that some keyboard-interactive prompts
6257 * can be echoing, in which case we'll set this to 1.
6261 if (!s->method && s->can_pubkey &&
6262 agent_exists() && !s->tried_agent) {
6264 * Attempt public-key authentication using Pageant.
6269 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6270 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6272 s->tried_agent = TRUE;
6274 logevent("Pageant is running. Requesting keys.");
6276 /* Request the keys held by the agent. */
6277 PUT_32BIT(s->request, 1);
6278 s->request[4] = SSH2_AGENTC_REQUEST_IDENTITIES;
6279 if (!agent_query(s->request, 5, &r, &s->responselen,
6280 ssh_agent_callback, ssh)) {
6284 bombout(("Unexpected data from server while"
6285 " waiting for agent response"));
6288 } while (pktin || inlen > 0);
6289 r = ssh->agent_response;
6290 s->responselen = ssh->agent_response_len;
6292 s->response = (unsigned char *) r;
6293 if (s->response && s->responselen >= 5 &&
6294 s->response[4] == SSH2_AGENT_IDENTITIES_ANSWER) {
6295 s->p = s->response + 5;
6296 s->nkeys = GET_32BIT(s->p);
6300 sprintf(buf, "Pageant has %d SSH2 keys", s->nkeys);
6303 for (s->keyi = 0; s->keyi < s->nkeys; s->keyi++) {
6308 sprintf(buf, "Trying Pageant key #%d", s->keyi);
6311 s->pklen = GET_32BIT(s->p);
6313 if (s->publickey_blob &&
6314 s->pklen == s->publickey_bloblen &&
6315 !memcmp(s->p, s->publickey_blob,
6316 s->publickey_bloblen)) {
6317 logevent("This key matches configured key file");
6318 s->tried_pubkey_config = 1;
6320 s->pkblob = (char *)s->p;
6322 s->alglen = GET_32BIT(s->pkblob);
6323 s->alg = s->pkblob + 4;
6324 s->commentlen = GET_32BIT(s->p);
6326 s->commentp = (char *)s->p;
6327 s->p += s->commentlen;
6328 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6329 ssh2_pkt_addstring(s->pktout, s->username);
6330 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6331 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6332 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6333 ssh2_pkt_addstring_start(s->pktout);
6334 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6335 ssh2_pkt_addstring_start(s->pktout);
6336 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6337 ssh2_pkt_send(ssh, s->pktout);
6339 crWaitUntilV(pktin);
6340 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6341 logevent("Key refused");
6345 if (flags & FLAG_VERBOSE) {
6346 c_write_str(ssh, "Authenticating with "
6348 c_write(ssh, s->commentp, s->commentlen);
6349 c_write_str(ssh, "\" from agent\r\n");
6353 * Server is willing to accept the key.
6354 * Construct a SIGN_REQUEST.
6356 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6357 ssh2_pkt_addstring(s->pktout, s->username);
6358 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6359 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6360 ssh2_pkt_addbool(s->pktout, TRUE);
6361 ssh2_pkt_addstring_start(s->pktout);
6362 ssh2_pkt_addstring_data(s->pktout, s->alg, s->alglen);
6363 ssh2_pkt_addstring_start(s->pktout);
6364 ssh2_pkt_addstring_data(s->pktout, s->pkblob, s->pklen);
6366 s->siglen = s->pktout->length - 5 + 4 + 20;
6367 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6369 s->len = 1; /* message type */
6370 s->len += 4 + s->pklen; /* key blob */
6371 s->len += 4 + s->siglen; /* data to sign */
6372 s->len += 4; /* flags */
6373 s->agentreq = snewn(4 + s->len, char);
6374 PUT_32BIT(s->agentreq, s->len);
6375 s->q = s->agentreq + 4;
6376 *s->q++ = SSH2_AGENTC_SIGN_REQUEST;
6377 PUT_32BIT(s->q, s->pklen);
6379 memcpy(s->q, s->pkblob, s->pklen);
6381 PUT_32BIT(s->q, s->siglen);
6383 /* Now the data to be signed... */
6384 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6385 PUT_32BIT(s->q, 20);
6388 memcpy(s->q, ssh->v2_session_id, 20);
6390 memcpy(s->q, s->pktout->data + 5,
6391 s->pktout->length - 5);
6392 s->q += s->pktout->length - 5;
6393 /* And finally the (zero) flags word. */
6395 if (!agent_query(s->agentreq, s->len + 4,
6397 ssh_agent_callback, ssh)) {
6401 bombout(("Unexpected data from server"
6402 " while waiting for agent"
6406 } while (pktin || inlen > 0);
6407 vret = ssh->agent_response;
6408 s->retlen = ssh->agent_response_len;
6413 if (s->ret[4] == SSH2_AGENT_SIGN_RESPONSE) {
6414 logevent("Sending Pageant's response");
6415 ssh2_add_sigblob(ssh, s->pktout,
6416 s->pkblob, s->pklen,
6418 GET_32BIT(s->ret + 5));
6419 ssh2_pkt_send(ssh, s->pktout);
6424 ("Pageant failed to answer challenge");
6435 if (!s->method && s->can_pubkey && s->publickey_blob
6436 && !s->tried_pubkey_config) {
6437 unsigned char *pub_blob;
6438 char *algorithm, *comment;
6441 s->tried_pubkey_config = TRUE;
6443 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6444 ssh->pkt_ctx |= SSH2_PKTCTX_PUBLICKEY;
6447 * Try the public key supplied in the configuration.
6449 * First, offer the public blob to see if the server is
6450 * willing to accept it.
6453 (unsigned char *)ssh2_userkey_loadpub(&ssh->cfg.keyfile,
6458 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6459 ssh2_pkt_addstring(s->pktout, s->username);
6460 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6461 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6462 ssh2_pkt_addbool(s->pktout, FALSE); /* no signature included */
6463 ssh2_pkt_addstring(s->pktout, algorithm);
6464 ssh2_pkt_addstring_start(s->pktout);
6465 ssh2_pkt_addstring_data(s->pktout, (char *)pub_blob,
6467 ssh2_pkt_send(ssh, s->pktout);
6468 logevent("Offered public key");
6470 crWaitUntilV(pktin);
6471 if (pktin->type != SSH2_MSG_USERAUTH_PK_OK) {
6473 s->type = AUTH_TYPE_PUBLICKEY_OFFER_LOUD;
6474 continue; /* key refused; give up on it */
6477 logevent("Offer of public key accepted");
6479 * Actually attempt a serious authentication using
6482 if (ssh2_userkey_encrypted(&ssh->cfg.keyfile, &comment)) {
6483 sprintf(s->pwprompt,
6484 "Passphrase for key \"%.100s\": ",
6490 if (flags & FLAG_VERBOSE) {
6491 c_write_str(ssh, "Authenticating with public key \"");
6492 c_write_str(ssh, comment);
6493 c_write_str(ssh, "\"\r\n");
6495 s->method = AUTH_PUBLICKEY_FILE;
6499 if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
6500 !s->kbd_inter_running) {
6501 s->method = AUTH_KEYBOARD_INTERACTIVE;
6502 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6504 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6505 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6507 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6508 ssh2_pkt_addstring(s->pktout, s->username);
6509 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6510 ssh2_pkt_addstring(s->pktout, "keyboard-interactive"); /* method */
6511 ssh2_pkt_addstring(s->pktout, ""); /* lang */
6512 ssh2_pkt_addstring(s->pktout, "");
6513 ssh2_pkt_send(ssh, s->pktout);
6515 crWaitUntilV(pktin);
6516 if (pktin->type != SSH2_MSG_USERAUTH_INFO_REQUEST) {
6517 if (pktin->type == SSH2_MSG_USERAUTH_FAILURE)
6519 logevent("Keyboard-interactive authentication refused");
6520 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
6521 s->kbd_inter_refused = TRUE; /* don't try it again */
6525 s->kbd_inter_running = TRUE;
6529 if (s->kbd_inter_running) {
6530 s->method = AUTH_KEYBOARD_INTERACTIVE;
6531 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6533 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6534 ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
6536 if (s->curr_prompt == 0) {
6538 * We've got a fresh USERAUTH_INFO_REQUEST.
6539 * Display header data, and start going through
6542 char *name, *inst, *lang;
6543 int name_len, inst_len, lang_len;
6545 ssh_pkt_getstring(pktin, &name, &name_len);
6546 ssh_pkt_getstring(pktin, &inst, &inst_len);
6547 ssh_pkt_getstring(pktin, &lang, &lang_len);
6549 c_write_untrusted(ssh, name, name_len);
6550 c_write_str(ssh, "\r\n");
6553 c_write_untrusted(ssh, inst, inst_len);
6554 c_write_str(ssh, "\r\n");
6556 s->num_prompts = ssh_pkt_getuint32(pktin);
6560 * If there are prompts remaining in the packet,
6561 * display one and get a response.
6563 if (s->curr_prompt < s->num_prompts) {
6567 ssh_pkt_getstring(pktin, &prompt, &prompt_len);
6568 if (prompt_len > 0) {
6569 static const char trunc[] = "<prompt truncated>: ";
6570 static const int prlen = sizeof(s->pwprompt) -
6572 if (prompt_len > prlen) {
6573 memcpy(s->pwprompt, prompt, prlen);
6574 strcpy(s->pwprompt + prlen, trunc);
6576 memcpy(s->pwprompt, prompt, prompt_len);
6577 s->pwprompt[prompt_len] = '\0';
6581 "<server failed to send prompt>: ");
6583 s->echo = ssh2_pkt_getbool(pktin);
6589 if (!s->method && s->can_passwd) {
6590 s->method = AUTH_PASSWORD;
6591 ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
6592 ssh->pkt_ctx |= SSH2_PKTCTX_PASSWORD;
6593 sprintf(s->pwprompt, "%.90s@%.90s's password: ", s->username,
6600 if (!ssh_get_line(s->pwprompt, s->password,
6601 sizeof(s->password), TRUE)) {
6603 * get_line failed to get a password (for
6604 * example because one was supplied on the
6605 * command line which has already failed to
6608 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6609 ssh2_pkt_adduint32(s->pktout,SSH2_DISCONNECT_BY_APPLICATION);
6610 ssh2_pkt_addstring(s->pktout, "No more passwords available"
6612 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6613 ssh2_pkt_send_noqueue(ssh, s->pktout);
6614 logevent("Unable to authenticate");
6615 connection_fatal(ssh->frontend,
6616 "Unable to authenticate");
6617 ssh_closing((Plug)ssh, NULL, 0, 0);
6621 int ret; /* need not be saved across crReturn */
6622 c_write_untrusted(ssh, s->pwprompt, strlen(s->pwprompt));
6625 setup_userpass_input(ssh, s->password,
6626 sizeof(s->password), s->echo);
6628 crWaitUntilV(!pktin);
6629 ret = process_userpass_input(ssh, in, inlen);
6633 c_write_str(ssh, "\r\n");
6637 if (s->method == AUTH_PUBLICKEY_FILE) {
6639 * We have our passphrase. Now try the actual authentication.
6641 struct ssh2_userkey *key;
6642 const char *error = NULL;
6644 key = ssh2_load_userkey(&ssh->cfg.keyfile, s->password,
6646 if (key == SSH2_WRONG_PASSPHRASE || key == NULL) {
6647 if (key == SSH2_WRONG_PASSPHRASE) {
6648 c_write_str(ssh, "Wrong passphrase\r\n");
6649 s->tried_pubkey_config = FALSE;
6651 c_write_str(ssh, "Unable to load private key (");
6652 c_write_str(ssh, error);
6653 c_write_str(ssh, ")\r\n");
6654 s->tried_pubkey_config = TRUE;
6656 /* Send a spurious AUTH_NONE to return to the top. */
6657 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6658 ssh2_pkt_addstring(s->pktout, s->username);
6659 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6660 ssh2_pkt_addstring(s->pktout, "none"); /* method */
6661 ssh2_pkt_send(ssh, s->pktout);
6662 s->type = AUTH_TYPE_NONE;
6664 unsigned char *pkblob, *sigblob, *sigdata;
6665 int pkblob_len, sigblob_len, sigdata_len;
6669 * We have loaded the private key and the server
6670 * has announced that it's willing to accept it.
6671 * Hallelujah. Generate a signature and send it.
6673 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6674 ssh2_pkt_addstring(s->pktout, s->username);
6675 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6676 ssh2_pkt_addstring(s->pktout, "publickey"); /* method */
6677 ssh2_pkt_addbool(s->pktout, TRUE);
6678 ssh2_pkt_addstring(s->pktout, key->alg->name);
6679 pkblob = key->alg->public_blob(key->data, &pkblob_len);
6680 ssh2_pkt_addstring_start(s->pktout);
6681 ssh2_pkt_addstring_data(s->pktout, (char *)pkblob, pkblob_len);
6684 * The data to be signed is:
6688 * followed by everything so far placed in the
6691 sigdata_len = s->pktout->length - 5 + 4 + 20;
6692 if (ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)
6694 sigdata = snewn(sigdata_len, unsigned char);
6696 if (!(ssh->remote_bugs & BUG_SSH2_PK_SESSIONID)) {
6697 PUT_32BIT(sigdata+p, 20);
6700 memcpy(sigdata+p, ssh->v2_session_id, 20); p += 20;
6701 memcpy(sigdata+p, s->pktout->data + 5,
6702 s->pktout->length - 5);
6703 p += s->pktout->length - 5;
6704 assert(p == sigdata_len);
6705 sigblob = key->alg->sign(key->data, (char *)sigdata,
6706 sigdata_len, &sigblob_len);
6707 ssh2_add_sigblob(ssh, s->pktout, pkblob, pkblob_len,
6708 sigblob, sigblob_len);
6713 ssh2_pkt_send(ssh, s->pktout);
6714 s->type = AUTH_TYPE_PUBLICKEY;
6715 key->alg->freekey(key->data);
6717 } else if (s->method == AUTH_PASSWORD) {
6719 * We send the password packet lumped tightly together with
6720 * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
6721 * string long enough to make the total length of the two
6722 * packets constant. This should ensure that a passive
6723 * listener doing traffic analyis can't work out the length
6726 * For this to work, we need an assumption about the
6727 * maximum length of the password packet. I think 256 is
6728 * pretty conservative. Anyone using a password longer than
6729 * that probably doesn't have much to worry about from
6730 * people who find out how long their password is!
6732 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
6733 ssh2_pkt_addstring(s->pktout, s->username);
6734 ssh2_pkt_addstring(s->pktout, "ssh-connection"); /* service requested */
6735 ssh2_pkt_addstring(s->pktout, "password");
6736 ssh2_pkt_addbool(s->pktout, FALSE);
6737 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6738 ssh2_pkt_addstring(s->pktout, s->password);
6739 memset(s->password, 0, sizeof(s->password));
6740 end_log_omission(ssh, s->pktout);
6741 ssh2_pkt_defer(ssh, s->pktout);
6743 * We'll include a string that's an exact multiple of the
6744 * cipher block size. If the cipher is NULL for some
6745 * reason, we don't do this trick at all because we gain
6748 if (ssh->cscipher) {
6751 stringlen = (256 - ssh->deferred_len);
6752 stringlen += ssh->cscipher->blksize - 1;
6753 stringlen -= (stringlen % ssh->cscipher->blksize);
6756 * Temporarily disable actual compression,
6757 * so we can guarantee to get this string
6758 * exactly the length we want it. The
6759 * compression-disabling routine should
6760 * return an integer indicating how many
6761 * bytes we should adjust our string length
6765 ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
6767 s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
6768 ssh2_pkt_addstring_start(s->pktout);
6769 for (i = 0; i < stringlen; i++) {
6770 char c = (char) random_byte();
6771 ssh2_pkt_addstring_data(s->pktout, &c, 1);
6773 ssh2_pkt_defer(ssh, s->pktout);
6775 ssh_pkt_defersend(ssh);
6776 logevent("Sent password");
6777 s->type = AUTH_TYPE_PASSWORD;
6778 } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
6779 if (s->curr_prompt == 0) {
6780 s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
6781 ssh2_pkt_adduint32(s->pktout, s->num_prompts);
6783 if (s->need_pw) { /* only add pw if we just got one! */
6784 dont_log_password(ssh, s->pktout, PKTLOG_BLANK);
6785 ssh2_pkt_addstring(s->pktout, s->password);
6786 memset(s->password, 0, sizeof(s->password));
6787 end_log_omission(ssh, s->pktout);
6790 if (s->curr_prompt >= s->num_prompts) {
6791 ssh2_pkt_send(ssh, s->pktout);
6794 * If there are prompts remaining, we set
6795 * `gotit' so that we won't attempt to get
6796 * another packet. Then we go back round the
6797 * loop and will end up retrieving another
6798 * prompt out of the existing packet. Funky or
6803 s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
6805 c_write_str(ssh, "No supported authentication methods"
6806 " left to try!\r\n");
6807 logevent("No supported authentications offered."
6809 s->pktout = ssh2_pkt_init(SSH2_MSG_DISCONNECT);
6810 ssh2_pkt_adduint32(s->pktout, SSH2_DISCONNECT_BY_APPLICATION);
6811 ssh2_pkt_addstring(s->pktout, "No supported authentication"
6812 " methods available");
6813 ssh2_pkt_addstring(s->pktout, "en"); /* language tag */
6814 ssh2_pkt_send_noqueue(ssh, s->pktout);
6815 ssh_closing((Plug)ssh, NULL, 0, 0);
6819 } while (!s->we_are_in);
6822 * Now we're authenticated for the connection protocol. The
6823 * connection protocol will automatically have started at this
6824 * point; there's no need to send SERVICE_REQUEST.
6827 ssh->channels = newtree234(ssh_channelcmp);
6830 * Set up handlers for some connection protocol messages, so we
6831 * don't have to handle them repeatedly in this coroutine.
6833 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] =
6834 ssh2_msg_channel_window_adjust;
6835 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] =
6836 ssh2_msg_global_request;
6839 * Create the main session channel.
6841 if (!ssh->cfg.ssh_no_shell) {
6842 ssh->mainchan = snew(struct ssh_channel);
6843 ssh->mainchan->ssh = ssh;
6844 ssh->mainchan->localid = alloc_channel_id(ssh);
6845 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
6846 ssh2_pkt_addstring(s->pktout, "session");
6847 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
6848 ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
6849 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
6850 ssh2_pkt_adduint32(s->pktout, 0x4000UL); /* our max pkt size */
6851 ssh2_pkt_send(ssh, s->pktout);
6852 crWaitUntilV(pktin);
6853 if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
6854 bombout(("Server refused to open a session"));
6856 /* FIXME: error data comes back in FAILURE packet */
6858 if (ssh_pkt_getuint32(pktin) != ssh->mainchan->localid) {
6859 bombout(("Server's channel confirmation cited wrong channel"));
6862 ssh->mainchan->remoteid = ssh_pkt_getuint32(pktin);
6863 ssh->mainchan->type = CHAN_MAINSESSION;
6864 ssh->mainchan->closes = 0;
6865 ssh->mainchan->v.v2.remwindow = ssh_pkt_getuint32(pktin);
6866 ssh->mainchan->v.v2.remmaxpkt = ssh_pkt_getuint32(pktin);
6867 bufchain_init(&ssh->mainchan->v.v2.outbuffer);
6868 add234(ssh->channels, ssh->mainchan);
6869 update_specials_menu(ssh->frontend);
6870 logevent("Opened channel for session");
6872 ssh->mainchan = NULL;
6875 * Now we have a channel, make dispatch table entries for
6876 * general channel-based messages.
6878 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] =
6879 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] =
6880 ssh2_msg_channel_data;
6881 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = ssh2_msg_channel_eof;
6882 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = ssh2_msg_channel_close;
6883 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] =
6884 ssh2_msg_channel_open_confirmation;
6885 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] =
6886 ssh2_msg_channel_open_failure;
6887 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] =
6888 ssh2_msg_channel_request;
6889 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] =
6890 ssh2_msg_channel_open;
6893 * Potentially enable X11 forwarding.
6895 if (ssh->mainchan && ssh->cfg.x11_forward) {
6896 char proto[20], data[64];
6897 logevent("Requesting X11 forwarding");
6898 ssh->x11auth = x11_invent_auth(proto, sizeof(proto),
6899 data, sizeof(data), ssh->cfg.x11_auth);
6900 x11_get_real_auth(ssh->x11auth, ssh->cfg.x11_display);
6901 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6902 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6903 ssh2_pkt_addstring(s->pktout, "x11-req");
6904 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6905 ssh2_pkt_addbool(s->pktout, 0); /* many connections */
6906 ssh2_pkt_addstring(s->pktout, proto);
6907 ssh2_pkt_addstring(s->pktout, data);
6908 ssh2_pkt_adduint32(s->pktout, x11_get_screen_number(ssh->cfg.x11_display));
6909 ssh2_pkt_send(ssh, s->pktout);
6911 crWaitUntilV(pktin);
6913 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6914 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6915 bombout(("Unexpected response to X11 forwarding request:"
6916 " packet type %d", pktin->type));
6919 logevent("X11 forwarding refused");
6921 logevent("X11 forwarding enabled");
6922 ssh->X11_fwd_enabled = TRUE;
6927 * Enable port forwardings.
6929 ssh_setup_portfwd(ssh, &ssh->cfg);
6932 * Potentially enable agent forwarding.
6934 if (ssh->mainchan && ssh->cfg.agentfwd && agent_exists()) {
6935 logevent("Requesting OpenSSH-style agent forwarding");
6936 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6937 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
6938 ssh2_pkt_addstring(s->pktout, "auth-agent-req@openssh.com");
6939 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6940 ssh2_pkt_send(ssh, s->pktout);
6942 crWaitUntilV(pktin);
6944 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6945 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6946 bombout(("Unexpected response to agent forwarding request:"
6947 " packet type %d", pktin->type));
6950 logevent("Agent forwarding refused");
6952 logevent("Agent forwarding enabled");
6953 ssh->agentfwd_enabled = TRUE;
6958 * Now allocate a pty for the session.
6960 if (ssh->mainchan && !ssh->cfg.nopty) {
6961 /* Unpick the terminal-speed string. */
6962 /* XXX perhaps we should allow no speeds to be sent. */
6963 ssh->ospeed = 38400; ssh->ispeed = 38400; /* last-resort defaults */
6964 sscanf(ssh->cfg.termspeed, "%d,%d", &ssh->ospeed, &ssh->ispeed);
6965 /* Build the pty request. */
6966 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
6967 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
6968 ssh2_pkt_addstring(s->pktout, "pty-req");
6969 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
6970 ssh2_pkt_addstring(s->pktout, ssh->cfg.termtype);
6971 ssh2_pkt_adduint32(s->pktout, ssh->term_width);
6972 ssh2_pkt_adduint32(s->pktout, ssh->term_height);
6973 ssh2_pkt_adduint32(s->pktout, 0); /* pixel width */
6974 ssh2_pkt_adduint32(s->pktout, 0); /* pixel height */
6975 ssh2_pkt_addstring_start(s->pktout);
6976 ssh2_pkt_addbyte(s->pktout, 128); /* TTY_OP_ISPEED */
6977 ssh2_pkt_adduint32(s->pktout, ssh->ispeed);
6978 ssh2_pkt_addbyte(s->pktout, 129); /* TTY_OP_OSPEED */
6979 ssh2_pkt_adduint32(s->pktout, ssh->ospeed);
6980 ssh2_pkt_addstring_data(s->pktout, "\0", 1); /* TTY_OP_END */
6981 ssh2_pkt_send(ssh, s->pktout);
6982 ssh->state = SSH_STATE_INTERMED;
6984 crWaitUntilV(pktin);
6986 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
6987 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
6988 bombout(("Unexpected response to pty request:"
6989 " packet type %d", pktin->type));
6992 c_write_str(ssh, "Server refused to allocate pty\r\n");
6993 ssh->editing = ssh->echoing = 1;
6995 logeventf(ssh, "Allocated pty (ospeed %dbps, ispeed %dbps)",
6996 ssh->ospeed, ssh->ispeed);
6999 ssh->editing = ssh->echoing = 1;
7003 * Send environment variables.
7005 * Simplest thing here is to send all the requests at once, and
7006 * then wait for a whole bunch of successes or failures.
7008 if (ssh->mainchan && *ssh->cfg.environmt) {
7009 char *e = ssh->cfg.environmt;
7010 char *var, *varend, *val;
7016 while (*e && *e != '\t') e++;
7018 if (*e == '\t') e++;
7023 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7024 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid);
7025 ssh2_pkt_addstring(s->pktout, "env");
7026 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7027 ssh2_pkt_addstring_start(s->pktout);
7028 ssh2_pkt_addstring_data(s->pktout, var, varend-var);
7029 ssh2_pkt_addstring(s->pktout, val);
7030 ssh2_pkt_send(ssh, s->pktout);
7035 logeventf(ssh, "Sent %d environment variables", s->num_env);
7038 s->env_left = s->num_env;
7040 while (s->env_left > 0) {
7041 crWaitUntilV(pktin);
7043 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7044 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7045 bombout(("Unexpected response to environment request:"
7046 " packet type %d", pktin->type));
7056 if (s->env_ok == s->num_env) {
7057 logevent("All environment variables successfully set");
7058 } else if (s->env_ok == 0) {
7059 logevent("All environment variables refused");
7060 c_write_str(ssh, "Server refused to set environment variables\r\n");
7062 logeventf(ssh, "%d environment variables refused",
7063 s->num_env - s->env_ok);
7064 c_write_str(ssh, "Server refused to set all environment variables\r\n");
7069 * Start a shell or a remote command. We may have to attempt
7070 * this twice if the config data has provided a second choice
7073 if (ssh->mainchan) while (1) {
7077 if (ssh->fallback_cmd) {
7078 subsys = ssh->cfg.ssh_subsys2;
7079 cmd = ssh->cfg.remote_cmd_ptr2;
7081 subsys = ssh->cfg.ssh_subsys;
7082 cmd = ssh->cfg.remote_cmd_ptr;
7085 s->pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7086 ssh2_pkt_adduint32(s->pktout, ssh->mainchan->remoteid); /* recipient channel */
7088 ssh2_pkt_addstring(s->pktout, "subsystem");
7089 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7090 ssh2_pkt_addstring(s->pktout, cmd);
7092 ssh2_pkt_addstring(s->pktout, "exec");
7093 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7094 ssh2_pkt_addstring(s->pktout, cmd);
7096 ssh2_pkt_addstring(s->pktout, "shell");
7097 ssh2_pkt_addbool(s->pktout, 1); /* want reply */
7099 ssh2_pkt_send(ssh, s->pktout);
7101 crWaitUntilV(pktin);
7103 if (pktin->type != SSH2_MSG_CHANNEL_SUCCESS) {
7104 if (pktin->type != SSH2_MSG_CHANNEL_FAILURE) {
7105 bombout(("Unexpected response to shell/command request:"
7106 " packet type %d", pktin->type));
7110 * We failed to start the command. If this is the
7111 * fallback command, we really are finished; if it's
7112 * not, and if the fallback command exists, try falling
7113 * back to it before complaining.
7115 if (!ssh->fallback_cmd && ssh->cfg.remote_cmd_ptr2 != NULL) {
7116 logevent("Primary command failed; attempting fallback");
7117 ssh->fallback_cmd = TRUE;
7120 bombout(("Server refused to start a shell/command"));
7123 logevent("Started a shell/command");
7128 ssh->state = SSH_STATE_SESSION;
7129 if (ssh->size_needed)
7130 ssh_size(ssh, ssh->term_width, ssh->term_height);
7131 if (ssh->eof_needed)
7132 ssh_special(ssh, TS_EOF);
7138 ldisc_send(ssh->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */
7143 s->try_send = FALSE;
7147 * _All_ the connection-layer packets we expect to
7148 * receive are now handled by the dispatch table.
7149 * Anything that reaches here must be bogus.
7152 bombout(("Strange packet received: type %d", pktin->type));
7154 } else if (ssh->mainchan) {
7156 * We have spare data. Add it to the channel buffer.
7158 ssh2_add_channel_data(ssh->mainchan, (char *)in, inlen);
7163 struct ssh_channel *c;
7165 * Try to send data on all channels if we can.
7167 for (i = 0; NULL != (c = index234(ssh->channels, i)); i++) {
7170 continue; /* don't send on closing channels */
7171 bufsize = ssh2_try_send(c);
7174 case CHAN_MAINSESSION:
7175 /* stdin need not receive an unthrottle
7176 * notification since it will be polled */
7179 x11_unthrottle(c->u.x11.s);
7182 /* agent sockets are request/response and need no
7183 * buffer management */
7186 pfd_unthrottle(c->u.pfd.s);
7198 * Handlers for SSH2 messages that might arrive at any moment.
7200 void ssh2_msg_disconnect(Ssh ssh, struct Packet *pktin)
7202 /* log reason code in disconnect message */
7204 int nowlen, reason, msglen;
7206 reason = ssh_pkt_getuint32(pktin);
7207 ssh_pkt_getstring(pktin, &msg, &msglen);
7209 if (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) {
7210 buf = dupprintf("Received disconnect message (%s)",
7211 ssh2_disconnect_reasons[reason]);
7213 buf = dupprintf("Received disconnect message (unknown"
7214 " type %d)", reason);
7218 buf = dupprintf("Disconnection message text: %n%.*s",
7219 &nowlen, msglen, msg);
7221 bombout(("Server sent disconnect message\ntype %d (%s):\n\"%s\"",
7223 (reason > 0 && reason < lenof(ssh2_disconnect_reasons)) ?
7224 ssh2_disconnect_reasons[reason] : "unknown",
7229 void ssh2_msg_debug(Ssh ssh, struct Packet *pktin)
7231 /* log the debug message */
7236 /* XXX maybe we should actually take notice of this */
7237 always_display = ssh2_pkt_getbool(pktin);
7238 ssh_pkt_getstring(pktin, &msg, &msglen);
7240 buf = dupprintf("Remote debug message: %.*s", msglen, msg);
7245 void ssh2_msg_something_unimplemented(Ssh ssh, struct Packet *pktin)
7247 struct Packet *pktout;
7248 pktout = ssh2_pkt_init(SSH2_MSG_UNIMPLEMENTED);
7249 ssh2_pkt_adduint32(pktout, pktin->sequence);
7251 * UNIMPLEMENTED messages MUST appear in the same order as the
7252 * messages they respond to. Hence, never queue them.
7254 ssh2_pkt_send_noqueue(ssh, pktout);
7258 * Handle the top-level SSH2 protocol.
7260 static void ssh2_protocol_setup(Ssh ssh)
7265 * Most messages cause SSH2_MSG_UNIMPLEMENTED.
7267 for (i = 0; i < 256; i++)
7268 ssh->packet_dispatch[i] = ssh2_msg_something_unimplemented;
7271 * Any message we actually understand, we set to NULL so that
7272 * the coroutines will get it.
7274 ssh->packet_dispatch[SSH2_MSG_UNIMPLEMENTED] = NULL;
7275 ssh->packet_dispatch[SSH2_MSG_SERVICE_REQUEST] = NULL;
7276 ssh->packet_dispatch[SSH2_MSG_SERVICE_ACCEPT] = NULL;
7277 ssh->packet_dispatch[SSH2_MSG_KEXINIT] = NULL;
7278 ssh->packet_dispatch[SSH2_MSG_NEWKEYS] = NULL;
7279 ssh->packet_dispatch[SSH2_MSG_KEXDH_INIT] = NULL;
7280 ssh->packet_dispatch[SSH2_MSG_KEXDH_REPLY] = NULL;
7281 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REQUEST] = NULL; duplicate case value */
7282 /* ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_GROUP] = NULL; duplicate case value */
7283 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_INIT] = NULL;
7284 ssh->packet_dispatch[SSH2_MSG_KEX_DH_GEX_REPLY] = NULL;
7285 ssh->packet_dispatch[SSH2_MSG_USERAUTH_REQUEST] = NULL;
7286 ssh->packet_dispatch[SSH2_MSG_USERAUTH_FAILURE] = NULL;
7287 ssh->packet_dispatch[SSH2_MSG_USERAUTH_SUCCESS] = NULL;
7288 ssh->packet_dispatch[SSH2_MSG_USERAUTH_BANNER] = NULL;
7289 ssh->packet_dispatch[SSH2_MSG_USERAUTH_PK_OK] = NULL;
7290 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ] = NULL; duplicate case value */
7291 /* ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_REQUEST] = NULL; duplicate case value */
7292 ssh->packet_dispatch[SSH2_MSG_USERAUTH_INFO_RESPONSE] = NULL;
7293 ssh->packet_dispatch[SSH2_MSG_GLOBAL_REQUEST] = NULL;
7294 ssh->packet_dispatch[SSH2_MSG_REQUEST_SUCCESS] = NULL;
7295 ssh->packet_dispatch[SSH2_MSG_REQUEST_FAILURE] = NULL;
7296 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN] = NULL;
7297 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_CONFIRMATION] = NULL;
7298 ssh->packet_dispatch[SSH2_MSG_CHANNEL_OPEN_FAILURE] = NULL;
7299 ssh->packet_dispatch[SSH2_MSG_CHANNEL_WINDOW_ADJUST] = NULL;
7300 ssh->packet_dispatch[SSH2_MSG_CHANNEL_DATA] = NULL;
7301 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EXTENDED_DATA] = NULL;
7302 ssh->packet_dispatch[SSH2_MSG_CHANNEL_EOF] = NULL;
7303 ssh->packet_dispatch[SSH2_MSG_CHANNEL_CLOSE] = NULL;
7304 ssh->packet_dispatch[SSH2_MSG_CHANNEL_REQUEST] = NULL;
7305 ssh->packet_dispatch[SSH2_MSG_CHANNEL_SUCCESS] = NULL;
7306 ssh->packet_dispatch[SSH2_MSG_CHANNEL_FAILURE] = NULL;
7309 * These special message types we install handlers for.
7311 ssh->packet_dispatch[SSH2_MSG_DISCONNECT] = ssh2_msg_disconnect;
7312 ssh->packet_dispatch[SSH2_MSG_IGNORE] = ssh_msg_ignore; /* shared with ssh1 */
7313 ssh->packet_dispatch[SSH2_MSG_DEBUG] = ssh2_msg_debug;
7316 static void ssh2_timer(void *ctx, long now)
7320 if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
7321 now - ssh->next_rekey >= 0) {
7322 do_ssh2_transport(ssh, "timeout", -1, NULL);
7326 static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
7327 struct Packet *pktin)
7329 if (ssh->state == SSH_STATE_CLOSED)
7333 ssh->incoming_data_size += pktin->encrypted_len;
7334 if (!ssh->kex_in_progress &&
7335 ssh->max_data_size != 0 &&
7336 ssh->incoming_data_size > ssh->max_data_size)
7337 do_ssh2_transport(ssh, "too much data received", -1, NULL);
7340 if (pktin && ssh->packet_dispatch[pktin->type]) {
7341 ssh->packet_dispatch[pktin->type](ssh, pktin);
7345 if (!ssh->protocol_initial_phase_done ||
7346 (pktin && pktin->type >= 20 && pktin->type < 50)) {
7347 if (do_ssh2_transport(ssh, in, inlen, pktin) &&
7348 !ssh->protocol_initial_phase_done) {
7349 ssh->protocol_initial_phase_done = TRUE;
7351 * Allow authconn to initialise itself.
7353 do_ssh2_authconn(ssh, NULL, 0, NULL);
7356 do_ssh2_authconn(ssh, in, inlen, pktin);
7361 * Called to set up the connection.
7363 * Returns an error message, or NULL on success.
7365 static const char *ssh_init(void *frontend_handle, void **backend_handle,
7367 char *host, int port, char **realhost, int nodelay,
7373 ssh = snew(struct ssh_tag);
7374 ssh->cfg = *cfg; /* STRUCTURE COPY */
7375 ssh->version = 0; /* when not ready yet */
7378 ssh->v1_cipher_ctx = NULL;
7379 ssh->crcda_ctx = NULL;
7380 ssh->cscipher = NULL;
7381 ssh->cs_cipher_ctx = NULL;
7382 ssh->sccipher = NULL;
7383 ssh->sc_cipher_ctx = NULL;
7385 ssh->cs_mac_ctx = NULL;
7387 ssh->sc_mac_ctx = NULL;
7389 ssh->cs_comp_ctx = NULL;
7391 ssh->sc_comp_ctx = NULL;
7393 ssh->kex_ctx = NULL;
7394 ssh->hostkey = NULL;
7396 ssh->state = SSH_STATE_PREPACKET;
7397 ssh->size_needed = FALSE;
7398 ssh->eof_needed = FALSE;
7401 ssh->deferred_send_data = NULL;
7402 ssh->deferred_len = 0;
7403 ssh->deferred_size = 0;
7404 ssh->fallback_cmd = 0;
7406 ssh->x11auth = NULL;
7407 ssh->v1_compressing = FALSE;
7408 ssh->v2_outgoing_sequence = 0;
7409 ssh->ssh1_rdpkt_crstate = 0;
7410 ssh->ssh2_rdpkt_crstate = 0;
7411 ssh->do_ssh_init_crstate = 0;
7412 ssh->ssh_gotdata_crstate = 0;
7413 ssh->do_ssh1_connection_crstate = 0;
7414 ssh->do_ssh1_login_crstate = 0;
7415 ssh->do_ssh2_transport_crstate = 0;
7416 ssh->do_ssh2_authconn_crstate = 0;
7417 ssh->do_ssh_init_state = NULL;
7418 ssh->do_ssh1_login_state = NULL;
7419 ssh->do_ssh2_transport_state = NULL;
7420 ssh->do_ssh2_authconn_state = NULL;
7421 ssh->mainchan = NULL;
7422 ssh->throttled_all = 0;
7423 ssh->v1_stdout_throttling = 0;
7425 ssh->queuelen = ssh->queuesize = 0;
7426 ssh->queueing = FALSE;
7427 ssh->qhead = ssh->qtail = NULL;
7428 ssh->deferred_rekey_reason = NULL;
7430 *backend_handle = ssh;
7433 if (crypto_startup() == 0)
7434 return "Microsoft high encryption pack not installed!";
7437 ssh->frontend = frontend_handle;
7438 ssh->term_width = ssh->cfg.width;
7439 ssh->term_height = ssh->cfg.height;
7441 ssh->channels = NULL;
7442 ssh->rportfwds = NULL;
7443 ssh->portfwds = NULL;
7448 ssh->v1_throttle_count = 0;
7449 ssh->overall_bufsize = 0;
7450 ssh->fallback_cmd = 0;
7452 ssh->protocol = NULL;
7454 ssh->protocol_initial_phase_done = FALSE;
7458 ssh->incoming_data_size = ssh->outgoing_data_size =
7459 ssh->deferred_data_size = 0L;
7460 ssh->max_data_size = parse_blocksize(ssh->cfg.ssh_rekey_data);
7461 ssh->kex_in_progress = FALSE;
7463 p = connect_to_host(ssh, host, port, realhost, nodelay, keepalive);
7472 static void ssh_free(void *handle)
7474 Ssh ssh = (Ssh) handle;
7475 struct ssh_channel *c;
7476 struct ssh_rportfwd *pf;
7478 if (ssh->v1_cipher_ctx)
7479 ssh->cipher->free_context(ssh->v1_cipher_ctx);
7480 if (ssh->cs_cipher_ctx)
7481 ssh->cscipher->free_context(ssh->cs_cipher_ctx);
7482 if (ssh->sc_cipher_ctx)
7483 ssh->sccipher->free_context(ssh->sc_cipher_ctx);
7484 if (ssh->cs_mac_ctx)
7485 ssh->csmac->free_context(ssh->cs_mac_ctx);
7486 if (ssh->sc_mac_ctx)
7487 ssh->scmac->free_context(ssh->sc_mac_ctx);
7488 if (ssh->cs_comp_ctx) {
7490 ssh->cscomp->compress_cleanup(ssh->cs_comp_ctx);
7492 zlib_compress_cleanup(ssh->cs_comp_ctx);
7494 if (ssh->sc_comp_ctx) {
7496 ssh->sccomp->decompress_cleanup(ssh->sc_comp_ctx);
7498 zlib_decompress_cleanup(ssh->sc_comp_ctx);
7501 dh_cleanup(ssh->kex_ctx);
7502 sfree(ssh->savedhost);
7504 while (ssh->queuelen-- > 0)
7505 ssh_free_packet(ssh->queue[ssh->queuelen]);
7508 while (ssh->qhead) {
7509 struct queued_handler *qh = ssh->qhead;
7510 ssh->qhead = qh->next;
7513 ssh->qhead = ssh->qtail = NULL;
7515 if (ssh->channels) {
7516 while ((c = delpos234(ssh->channels, 0)) != NULL) {
7519 if (c->u.x11.s != NULL)
7520 x11_close(c->u.x11.s);
7523 if (c->u.pfd.s != NULL)
7524 pfd_close(c->u.pfd.s);
7529 freetree234(ssh->channels);
7530 ssh->channels = NULL;
7533 if (ssh->rportfwds) {
7534 while ((pf = delpos234(ssh->rportfwds, 0)) != NULL)
7536 freetree234(ssh->rportfwds);
7537 ssh->rportfwds = NULL;
7539 sfree(ssh->deferred_send_data);
7541 x11_free_auth(ssh->x11auth);
7542 sfree(ssh->do_ssh_init_state);
7543 sfree(ssh->do_ssh1_login_state);
7544 sfree(ssh->do_ssh2_transport_state);
7545 sfree(ssh->do_ssh2_authconn_state);
7546 if (ssh->crcda_ctx) {
7547 crcda_free_context(ssh->crcda_ctx);
7548 ssh->crcda_ctx = NULL;
7552 expire_timer_context(ssh);
7554 pinger_free(ssh->pinger);
7561 * Reconfigure the SSH backend.
7563 static void ssh_reconfig(void *handle, Config *cfg)
7565 Ssh ssh = (Ssh) handle;
7566 char *rekeying = NULL, rekey_mandatory = FALSE;
7567 unsigned long old_max_data_size;
7569 pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
7570 ssh_setup_portfwd(ssh, cfg);
7572 if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
7573 cfg->ssh_rekey_time != 0) {
7574 long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
7575 long now = GETTICKCOUNT();
7577 if (new_next - now < 0) {
7578 rekeying = "timeout shortened";
7580 ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
7584 old_max_data_size = ssh->max_data_size;
7585 ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
7586 if (old_max_data_size != ssh->max_data_size &&
7587 ssh->max_data_size != 0) {
7588 if (ssh->outgoing_data_size > ssh->max_data_size ||
7589 ssh->incoming_data_size > ssh->max_data_size)
7590 rekeying = "data limit lowered";
7593 if (ssh->cfg.compression != cfg->compression) {
7594 rekeying = "compression setting changed";
7595 rekey_mandatory = TRUE;
7598 if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
7599 memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
7600 sizeof(ssh->cfg.ssh_cipherlist))) {
7601 rekeying = "cipher settings changed";
7602 rekey_mandatory = TRUE;
7605 ssh->cfg = *cfg; /* STRUCTURE COPY */
7608 if (!ssh->kex_in_progress) {
7609 do_ssh2_transport(ssh, rekeying, -1, NULL);
7610 } else if (rekey_mandatory) {
7611 ssh->deferred_rekey_reason = rekeying;
7617 * Called to send data down the Telnet connection.
7619 static int ssh_send(void *handle, char *buf, int len)
7621 Ssh ssh = (Ssh) handle;
7623 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7626 ssh->protocol(ssh, (unsigned char *)buf, len, 0);
7628 return ssh_sendbuffer(ssh);
7632 * Called to query the current amount of buffered stdin data.
7634 static int ssh_sendbuffer(void *handle)
7636 Ssh ssh = (Ssh) handle;
7639 if (ssh == NULL || ssh->s == NULL || ssh->protocol == NULL)
7643 * If the SSH socket itself has backed up, add the total backup
7644 * size on that to any individual buffer on the stdin channel.
7647 if (ssh->throttled_all)
7648 override_value = ssh->overall_bufsize;
7650 if (ssh->version == 1) {
7651 return override_value;
7652 } else if (ssh->version == 2) {
7653 if (!ssh->mainchan || ssh->mainchan->closes > 0)
7654 return override_value;
7656 return (override_value +
7657 bufchain_size(&ssh->mainchan->v.v2.outbuffer));
7664 * Called to set the size of the window from SSH's POV.
7666 static void ssh_size(void *handle, int width, int height)
7668 Ssh ssh = (Ssh) handle;
7669 struct Packet *pktout;
7671 ssh->term_width = width;
7672 ssh->term_height = height;
7674 switch (ssh->state) {
7675 case SSH_STATE_BEFORE_SIZE:
7676 case SSH_STATE_PREPACKET:
7677 case SSH_STATE_CLOSED:
7678 break; /* do nothing */
7679 case SSH_STATE_INTERMED:
7680 ssh->size_needed = TRUE; /* buffer for later */
7682 case SSH_STATE_SESSION:
7683 if (!ssh->cfg.nopty) {
7684 if (ssh->version == 1) {
7685 send_packet(ssh, SSH1_CMSG_WINDOW_SIZE,
7686 PKT_INT, ssh->term_height,
7687 PKT_INT, ssh->term_width,
7688 PKT_INT, 0, PKT_INT, 0, PKT_END);
7689 } else if (ssh->mainchan) {
7690 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7691 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7692 ssh2_pkt_addstring(pktout, "window-change");
7693 ssh2_pkt_addbool(pktout, 0);
7694 ssh2_pkt_adduint32(pktout, ssh->term_width);
7695 ssh2_pkt_adduint32(pktout, ssh->term_height);
7696 ssh2_pkt_adduint32(pktout, 0);
7697 ssh2_pkt_adduint32(pktout, 0);
7698 ssh2_pkt_send(ssh, pktout);
7706 * Return a list of the special codes that make sense in this
7709 static const struct telnet_special *ssh_get_specials(void *handle)
7711 static const struct telnet_special ssh1_ignore_special[] = {
7712 {"IGNORE message", TS_NOP}
7714 static const struct telnet_special ssh2_transport_specials[] = {
7715 {"IGNORE message", TS_NOP},
7716 {"Repeat key exchange", TS_REKEY},
7718 static const struct telnet_special ssh2_session_specials[] = {
7721 /* These are the signal names defined by draft-ietf-secsh-connect-23.
7722 * They include all the ISO C signals, but are a subset of the POSIX
7723 * required signals. */
7724 {"SIGINT (Interrupt)", TS_SIGINT},
7725 {"SIGTERM (Terminate)", TS_SIGTERM},
7726 {"SIGKILL (Kill)", TS_SIGKILL},
7727 {"SIGQUIT (Quit)", TS_SIGQUIT},
7728 {"SIGHUP (Hangup)", TS_SIGHUP},
7729 {"More signals", TS_SUBMENU},
7730 {"SIGABRT", TS_SIGABRT}, {"SIGALRM", TS_SIGALRM},
7731 {"SIGFPE", TS_SIGFPE}, {"SIGILL", TS_SIGILL},
7732 {"SIGPIPE", TS_SIGPIPE}, {"SIGSEGV", TS_SIGSEGV},
7733 {"SIGUSR1", TS_SIGUSR1}, {"SIGUSR2", TS_SIGUSR2},
7736 static const struct telnet_special specials_end[] = {
7739 /* XXX review this length for any changes: */
7740 static struct telnet_special ssh_specials[lenof(ssh2_transport_specials) +
7741 lenof(ssh2_session_specials) +
7742 lenof(specials_end)];
7743 Ssh ssh = (Ssh) handle;
7745 #define ADD_SPECIALS(name) \
7747 assert((i + lenof(name)) <= lenof(ssh_specials)); \
7748 memcpy(&ssh_specials[i], name, sizeof name); \
7752 if (ssh->version == 1) {
7753 /* Don't bother offering IGNORE if we've decided the remote
7754 * won't cope with it, since we wouldn't bother sending it if
7756 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7757 ADD_SPECIALS(ssh1_ignore_special);
7758 } else if (ssh->version == 2) {
7759 ADD_SPECIALS(ssh2_transport_specials);
7761 ADD_SPECIALS(ssh2_session_specials);
7762 } /* else we're not ready yet */
7765 ADD_SPECIALS(specials_end);
7766 return ssh_specials;
7774 * Send Telnet special codes. TS_EOF is useful for `plink', so you
7775 * can send an EOF and collect resulting output (e.g. `plink
7778 static void ssh_special(void *handle, Telnet_Special code)
7780 Ssh ssh = (Ssh) handle;
7781 struct Packet *pktout;
7783 if (code == TS_EOF) {
7784 if (ssh->state != SSH_STATE_SESSION) {
7786 * Buffer the EOF in case we are pre-SESSION, so we can
7787 * send it as soon as we reach SESSION.
7790 ssh->eof_needed = TRUE;
7793 if (ssh->version == 1) {
7794 send_packet(ssh, SSH1_CMSG_EOF, PKT_END);
7795 } else if (ssh->mainchan) {
7796 struct Packet *pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
7797 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7798 ssh2_pkt_send(ssh, pktout);
7800 logevent("Sent EOF message");
7801 } else if (code == TS_PING || code == TS_NOP) {
7802 if (ssh->state == SSH_STATE_CLOSED
7803 || ssh->state == SSH_STATE_PREPACKET) return;
7804 if (ssh->version == 1) {
7805 if (!(ssh->remote_bugs & BUG_CHOKES_ON_SSH1_IGNORE))
7806 send_packet(ssh, SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
7808 pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
7809 ssh2_pkt_addstring_start(pktout);
7810 ssh2_pkt_send_noqueue(ssh, pktout);
7812 } else if (code == TS_REKEY) {
7813 if (!ssh->kex_in_progress && ssh->version == 2) {
7814 do_ssh2_transport(ssh, "at user request", -1, NULL);
7816 } else if (code == TS_BRK) {
7817 if (ssh->state == SSH_STATE_CLOSED
7818 || ssh->state == SSH_STATE_PREPACKET) return;
7819 if (ssh->version == 1) {
7820 logevent("Unable to send BREAK signal in SSH1");
7821 } else if (ssh->mainchan) {
7822 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7823 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7824 ssh2_pkt_addstring(pktout, "break");
7825 ssh2_pkt_addbool(pktout, 0);
7826 ssh2_pkt_adduint32(pktout, 0); /* default break length */
7827 ssh2_pkt_send(ssh, pktout);
7830 /* Is is a POSIX signal? */
7831 char *signame = NULL;
7832 if (code == TS_SIGABRT) signame = "ABRT";
7833 if (code == TS_SIGALRM) signame = "ALRM";
7834 if (code == TS_SIGFPE) signame = "FPE";
7835 if (code == TS_SIGHUP) signame = "HUP";
7836 if (code == TS_SIGILL) signame = "ILL";
7837 if (code == TS_SIGINT) signame = "INT";
7838 if (code == TS_SIGKILL) signame = "KILL";
7839 if (code == TS_SIGPIPE) signame = "PIPE";
7840 if (code == TS_SIGQUIT) signame = "QUIT";
7841 if (code == TS_SIGSEGV) signame = "SEGV";
7842 if (code == TS_SIGTERM) signame = "TERM";
7843 if (code == TS_SIGUSR1) signame = "USR1";
7844 if (code == TS_SIGUSR2) signame = "USR2";
7845 /* The SSH-2 protocol does in principle support arbitrary named
7846 * signals, including signame@domain, but we don't support those. */
7848 /* It's a signal. */
7849 if (ssh->version == 2 && ssh->mainchan) {
7850 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
7851 ssh2_pkt_adduint32(pktout, ssh->mainchan->remoteid);
7852 ssh2_pkt_addstring(pktout, "signal");
7853 ssh2_pkt_addbool(pktout, 0);
7854 ssh2_pkt_addstring(pktout, signame);
7855 ssh2_pkt_send(ssh, pktout);
7856 logeventf(ssh, "Sent signal SIG%s", signame);
7859 /* Never heard of it. Do nothing */
7864 void *new_sock_channel(void *handle, Socket s)
7866 Ssh ssh = (Ssh) handle;
7867 struct ssh_channel *c;
7868 c = snew(struct ssh_channel);
7872 c->remoteid = -1; /* to be set when open confirmed */
7873 c->localid = alloc_channel_id(ssh);
7875 c->type = CHAN_SOCKDATA_DORMANT;/* identify channel type */
7877 bufchain_init(&c->v.v2.outbuffer);
7878 add234(ssh->channels, c);
7884 * This is called when stdout/stderr (the entity to which
7885 * from_backend sends data) manages to clear some backlog.
7887 static void ssh_unthrottle(void *handle, int bufsize)
7889 Ssh ssh = (Ssh) handle;
7890 if (ssh->version == 1) {
7891 if (ssh->v1_stdout_throttling && bufsize < SSH1_BUFFER_LIMIT) {
7892 ssh->v1_stdout_throttling = 0;
7893 ssh1_throttle(ssh, -1);
7896 if (ssh->mainchan && ssh->mainchan->closes == 0)
7897 ssh2_set_window(ssh->mainchan, OUR_V2_WINSIZE - bufsize);
7901 void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
7903 struct ssh_channel *c = (struct ssh_channel *)channel;
7905 struct Packet *pktout;
7907 logeventf(ssh, "Opening forwarded connection to %s:%d", hostname, port);
7909 if (ssh->version == 1) {
7910 send_packet(ssh, SSH1_MSG_PORT_OPEN,
7911 PKT_INT, c->localid,
7914 /* PKT_STR, <org:orgport>, */
7917 pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
7918 ssh2_pkt_addstring(pktout, "direct-tcpip");
7919 ssh2_pkt_adduint32(pktout, c->localid);
7920 c->v.v2.locwindow = OUR_V2_WINSIZE;
7921 ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
7922 ssh2_pkt_adduint32(pktout, 0x4000UL); /* our max pkt size */
7923 ssh2_pkt_addstring(pktout, hostname);
7924 ssh2_pkt_adduint32(pktout, port);
7926 * We make up values for the originator data; partly it's
7927 * too much hassle to keep track, and partly I'm not
7928 * convinced the server should be told details like that
7929 * about my local network configuration.
7931 ssh2_pkt_addstring(pktout, "client-side-connection");
7932 ssh2_pkt_adduint32(pktout, 0);
7933 ssh2_pkt_send(ssh, pktout);
7937 static Socket ssh_socket(void *handle)
7939 Ssh ssh = (Ssh) handle;
7943 static int ssh_sendok(void *handle)
7945 Ssh ssh = (Ssh) handle;
7946 return ssh->send_ok;
7949 static int ssh_ldisc(void *handle, int option)
7951 Ssh ssh = (Ssh) handle;
7952 if (option == LD_ECHO)
7953 return ssh->echoing;
7954 if (option == LD_EDIT)
7955 return ssh->editing;
7959 static void ssh_provide_ldisc(void *handle, void *ldisc)
7961 Ssh ssh = (Ssh) handle;
7965 static void ssh_provide_logctx(void *handle, void *logctx)
7967 Ssh ssh = (Ssh) handle;
7968 ssh->logctx = logctx;
7971 static int ssh_return_exitcode(void *handle)
7973 Ssh ssh = (Ssh) handle;
7977 return (ssh->exitcode >= 0 ? ssh->exitcode : 0);
7981 * cfg_info for SSH is the currently running version of the
7982 * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
7984 static int ssh_cfg_info(void *handle)
7986 Ssh ssh = (Ssh) handle;
7987 return ssh->version;
7991 * Gross hack: pscp will try to start SFTP but fall back to scp1 if
7992 * that fails. This variable is the means by which scp.c can reach
7993 * into the SSH code and find out which one it got.
7995 extern int ssh_fallback_cmd(void *handle)
7997 Ssh ssh = (Ssh) handle;
7998 return ssh->fallback_cmd;
8001 Backend ssh_backend = {
8011 ssh_return_exitcode,