1 /* Copyright (c) 2004-2007, Sara Golemon <sarag@libssh2.org>
2 * Copyright (c) 2005 Mikhail Gusarov <dottedmag@dottedmag.net>
3 * Copyright (c) 2009-2014 by Daniel Stenberg
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms,
7 * with or without modification, are permitted provided
8 * that the following conditions are met:
9 *
10 * Redistributions of source code must retain the above
11 * copyright notice, this list of conditions and the
12 * following disclaimer.
13 *
14 * Redistributions in binary form must reproduce the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer in the documentation and/or other materials
17 * provided with the distribution.
18 *
19 * Neither the name of the copyright holder nor the names
20 * of any other contributors may be used to endorse or
21 * promote products derived from this software without
22 * specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
25 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
26 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
29 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
31 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
34 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
36 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
37 * OF SUCH DAMAGE.
38 */
39
40 #include "libssh2_priv.h"
41
42 #include <ctype.h>
43 #include <stdio.h>
44
45 #include <assert.h>
46
47 /* Needed for struct iovec on some platforms */
48 #ifdef HAVE_SYS_UIO_H
49 #include <sys/uio.h>
50 #endif
51
52 #include "transport.h"
53 #include "session.h"
54 #include "userauth.h"
55
56 /* libssh2_userauth_list
57 *
58 * List authentication methods
59 * Will yield successful login if "none" happens to be allowable for this user
60 * Not a common configuration for any SSH server though
61 * username should be NULL, or a null terminated string
62 */
userauth_list(LIBSSH2_SESSION * session,const char * username,unsigned int username_len)63 static char *userauth_list(LIBSSH2_SESSION *session, const char *username,
64 unsigned int username_len)
65 {
66 static const unsigned char reply_codes[3] =
67 { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, 0 };
68 /* packet_type(1) + username_len(4) + service_len(4) +
69 service(14)"ssh-connection" + method_len(4) = 27 */
70 unsigned long methods_len;
71 unsigned char *s;
72 int rc;
73
74 if(session->userauth_list_state == libssh2_NB_state_idle) {
75 /* Zero the whole thing out */
76 memset(&session->userauth_list_packet_requirev_state, 0,
77 sizeof(session->userauth_list_packet_requirev_state));
78
79 session->userauth_list_data_len = username_len + 27;
80
81 s = session->userauth_list_data =
82 LIBSSH2_ALLOC(session, session->userauth_list_data_len);
83 if(!session->userauth_list_data) {
84 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
85 "Unable to allocate memory for userauth_list");
86 return NULL;
87 }
88
89 *(s++) = SSH_MSG_USERAUTH_REQUEST;
90 _libssh2_store_str(&s, username, username_len);
91 _libssh2_store_str(&s, "ssh-connection", 14);
92 _libssh2_store_u32(&s, 4); /* send "none" separately */
93
94 session->userauth_list_state = libssh2_NB_state_created;
95 }
96
97 if(session->userauth_list_state == libssh2_NB_state_created) {
98 rc = _libssh2_transport_send(session, session->userauth_list_data,
99 session->userauth_list_data_len,
100 (unsigned char *)"none", 4);
101 if(rc == LIBSSH2_ERROR_EAGAIN) {
102 _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
103 "Would block requesting userauth list");
104 return NULL;
105 }
106 /* now free the packet that was sent */
107 LIBSSH2_FREE(session, session->userauth_list_data);
108 session->userauth_list_data = NULL;
109
110 if(rc) {
111 _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
112 "Unable to send userauth-none request");
113 session->userauth_list_state = libssh2_NB_state_idle;
114 return NULL;
115 }
116
117 session->userauth_list_state = libssh2_NB_state_sent;
118 }
119
120 if(session->userauth_list_state == libssh2_NB_state_sent) {
121 rc = _libssh2_packet_requirev(session, reply_codes,
122 &session->userauth_list_data,
123 &session->userauth_list_data_len, 0,
124 NULL, 0,
125 &session->userauth_list_packet_requirev_state);
126 if(rc == LIBSSH2_ERROR_EAGAIN) {
127 _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
128 "Would block requesting userauth list");
129 return NULL;
130 }
131 else if(rc || (session->userauth_list_data_len < 1)) {
132 _libssh2_error(session, rc, "Failed getting response");
133 session->userauth_list_state = libssh2_NB_state_idle;
134 return NULL;
135 }
136
137 if(session->userauth_list_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
138 /* Wow, who'dve thought... */
139 _libssh2_error(session, LIBSSH2_ERROR_NONE, "No error");
140 LIBSSH2_FREE(session, session->userauth_list_data);
141 session->userauth_list_data = NULL;
142 session->state |= LIBSSH2_STATE_AUTHENTICATED;
143 session->userauth_list_state = libssh2_NB_state_idle;
144 return NULL;
145 }
146
147 if(session->userauth_list_data_len < 5) {
148 LIBSSH2_FREE(session, session->userauth_list_data);
149 session->userauth_list_data = NULL;
150 _libssh2_error(session, LIBSSH2_ERROR_PROTO,
151 "Unexpected packet size");
152 return NULL;
153 }
154
155 methods_len = _libssh2_ntohu32(session->userauth_list_data + 1);
156 if(methods_len >= session->userauth_list_data_len - 5) {
157 _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY,
158 "Unexpected userauth list size");
159 return NULL;
160 }
161
162 /* Do note that the memory areas overlap! */
163 memmove(session->userauth_list_data, session->userauth_list_data + 5,
164 methods_len);
165 session->userauth_list_data[methods_len] = '\0';
166 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
167 "Permitted auth methods: %s",
168 session->userauth_list_data);
169 }
170
171 session->userauth_list_state = libssh2_NB_state_idle;
172 return (char *) session->userauth_list_data;
173 }
174
175 /* libssh2_userauth_list
176 *
177 * List authentication methods
178 * Will yield successful login if "none" happens to be allowable for this user
179 * Not a common configuration for any SSH server though
180 * username should be NULL, or a null terminated string
181 */
182 LIBSSH2_API char *
libssh2_userauth_list(LIBSSH2_SESSION * session,const char * user,unsigned int user_len)183 libssh2_userauth_list(LIBSSH2_SESSION * session, const char *user,
184 unsigned int user_len)
185 {
186 char *ptr;
187 BLOCK_ADJUST_ERRNO(ptr, session,
188 userauth_list(session, user, user_len));
189 return ptr;
190 }
191
192 /*
193 * libssh2_userauth_authenticated
194 *
195 * Returns: 0 if not yet authenticated
196 * 1 if already authenticated
197 */
198 LIBSSH2_API int
libssh2_userauth_authenticated(LIBSSH2_SESSION * session)199 libssh2_userauth_authenticated(LIBSSH2_SESSION * session)
200 {
201 return (session->state & LIBSSH2_STATE_AUTHENTICATED)?1:0;
202 }
203
204
205
206 /* userauth_password
207 * Plain ol' login
208 */
209 static int
userauth_password(LIBSSH2_SESSION * session,const char * username,unsigned int username_len,const unsigned char * password,unsigned int password_len,LIBSSH2_PASSWD_CHANGEREQ_FUNC ((* passwd_change_cb)))210 userauth_password(LIBSSH2_SESSION *session,
211 const char *username, unsigned int username_len,
212 const unsigned char *password, unsigned int password_len,
213 LIBSSH2_PASSWD_CHANGEREQ_FUNC((*passwd_change_cb)))
214 {
215 unsigned char *s;
216 static const unsigned char reply_codes[4] =
217 { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE,
218 SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, 0
219 };
220 int rc;
221
222 if(session->userauth_pswd_state == libssh2_NB_state_idle) {
223 /* Zero the whole thing out */
224 memset(&session->userauth_pswd_packet_requirev_state, 0,
225 sizeof(session->userauth_pswd_packet_requirev_state));
226
227 /*
228 * 40 = packet_type(1) + username_len(4) + service_len(4) +
229 * service(14)"ssh-connection" + method_len(4) + method(8)"password" +
230 * chgpwdbool(1) + password_len(4) */
231 session->userauth_pswd_data_len = username_len + 40;
232
233 session->userauth_pswd_data0 =
234 (unsigned char) ~SSH_MSG_USERAUTH_PASSWD_CHANGEREQ;
235
236 /* TODO: remove this alloc with a fixed buffer in the session
237 struct */
238 s = session->userauth_pswd_data =
239 LIBSSH2_ALLOC(session, session->userauth_pswd_data_len);
240 if(!session->userauth_pswd_data) {
241 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
242 "Unable to allocate memory for "
243 "userauth-password request");
244 }
245
246 *(s++) = SSH_MSG_USERAUTH_REQUEST;
247 _libssh2_store_str(&s, username, username_len);
248 _libssh2_store_str(&s, "ssh-connection", sizeof("ssh-connection") - 1);
249 _libssh2_store_str(&s, "password", sizeof("password") - 1);
250 *s++ = '\0';
251 _libssh2_store_u32(&s, password_len);
252 /* 'password' is sent separately */
253
254 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
255 "Attempting to login using password authentication");
256
257 session->userauth_pswd_state = libssh2_NB_state_created;
258 }
259
260 if(session->userauth_pswd_state == libssh2_NB_state_created) {
261 rc = _libssh2_transport_send(session, session->userauth_pswd_data,
262 session->userauth_pswd_data_len,
263 password, password_len);
264 if(rc == LIBSSH2_ERROR_EAGAIN) {
265 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
266 "Would block writing password request");
267 }
268
269 /* now free the sent packet */
270 LIBSSH2_FREE(session, session->userauth_pswd_data);
271 session->userauth_pswd_data = NULL;
272
273 if(rc) {
274 session->userauth_pswd_state = libssh2_NB_state_idle;
275 return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
276 "Unable to send userauth-password request");
277 }
278
279 session->userauth_pswd_state = libssh2_NB_state_sent;
280 }
281
282 password_response:
283
284 if((session->userauth_pswd_state == libssh2_NB_state_sent)
285 || (session->userauth_pswd_state == libssh2_NB_state_sent1)
286 || (session->userauth_pswd_state == libssh2_NB_state_sent2)) {
287 if(session->userauth_pswd_state == libssh2_NB_state_sent) {
288 rc = _libssh2_packet_requirev(session, reply_codes,
289 &session->userauth_pswd_data,
290 &session->userauth_pswd_data_len,
291 0, NULL, 0,
292 &session->
293 userauth_pswd_packet_requirev_state);
294
295 if(rc) {
296 if(rc != LIBSSH2_ERROR_EAGAIN)
297 session->userauth_pswd_state = libssh2_NB_state_idle;
298
299 return _libssh2_error(session, rc,
300 "Waiting for password response");
301 }
302 else if(session->userauth_pswd_data_len < 1) {
303 session->userauth_pswd_state = libssh2_NB_state_idle;
304 return _libssh2_error(session, LIBSSH2_ERROR_PROTO,
305 "Unexpected packet size");
306 }
307
308 if(session->userauth_pswd_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
309 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
310 "Password authentication successful");
311 LIBSSH2_FREE(session, session->userauth_pswd_data);
312 session->userauth_pswd_data = NULL;
313 session->state |= LIBSSH2_STATE_AUTHENTICATED;
314 session->userauth_pswd_state = libssh2_NB_state_idle;
315 return 0;
316 }
317 else if(session->userauth_pswd_data[0] ==
318 SSH_MSG_USERAUTH_FAILURE) {
319 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
320 "Password authentication failed");
321 LIBSSH2_FREE(session, session->userauth_pswd_data);
322 session->userauth_pswd_data = NULL;
323 session->userauth_pswd_state = libssh2_NB_state_idle;
324 return _libssh2_error(session,
325 LIBSSH2_ERROR_AUTHENTICATION_FAILED,
326 "Authentication failed "
327 "(username/password)");
328 }
329
330 session->userauth_pswd_newpw = NULL;
331 session->userauth_pswd_newpw_len = 0;
332
333 session->userauth_pswd_state = libssh2_NB_state_sent1;
334 }
335
336 if(session->userauth_pswd_data_len < 1) {
337 session->userauth_pswd_state = libssh2_NB_state_idle;
338 return _libssh2_error(session, LIBSSH2_ERROR_PROTO,
339 "Unexpected packet size");
340 }
341
342 if((session->userauth_pswd_data[0] ==
343 SSH_MSG_USERAUTH_PASSWD_CHANGEREQ)
344 || (session->userauth_pswd_data0 ==
345 SSH_MSG_USERAUTH_PASSWD_CHANGEREQ)) {
346 session->userauth_pswd_data0 = SSH_MSG_USERAUTH_PASSWD_CHANGEREQ;
347
348 if((session->userauth_pswd_state == libssh2_NB_state_sent1) ||
349 (session->userauth_pswd_state == libssh2_NB_state_sent2)) {
350 if(session->userauth_pswd_state == libssh2_NB_state_sent1) {
351 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
352 "Password change required");
353 LIBSSH2_FREE(session, session->userauth_pswd_data);
354 session->userauth_pswd_data = NULL;
355 }
356 if(passwd_change_cb) {
357 if(session->userauth_pswd_state ==
358 libssh2_NB_state_sent1) {
359 passwd_change_cb(session,
360 &session->userauth_pswd_newpw,
361 &session->userauth_pswd_newpw_len,
362 &session->abstract);
363 if(!session->userauth_pswd_newpw) {
364 return _libssh2_error(session,
365 LIBSSH2_ERROR_PASSWORD_EXPIRED,
366 "Password expired, and "
367 "callback failed");
368 }
369
370 /* basic data_len + newpw_len(4) */
371 if(username_len + password_len + 44 <= UINT_MAX) {
372 session->userauth_pswd_data_len =
373 username_len + password_len + 44;
374 s = session->userauth_pswd_data =
375 LIBSSH2_ALLOC(session,
376 session->userauth_pswd_data_len);
377 }
378 else {
379 s = session->userauth_pswd_data = NULL;
380 session->userauth_pswd_data_len = 0;
381 }
382
383 if(!session->userauth_pswd_data) {
384 LIBSSH2_FREE(session,
385 session->userauth_pswd_newpw);
386 session->userauth_pswd_newpw = NULL;
387 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
388 "Unable to allocate memory "
389 "for userauth password "
390 "change request");
391 }
392
393 *(s++) = SSH_MSG_USERAUTH_REQUEST;
394 _libssh2_store_str(&s, username, username_len);
395 _libssh2_store_str(&s, "ssh-connection",
396 sizeof("ssh-connection") - 1);
397 _libssh2_store_str(&s, "password",
398 sizeof("password") - 1);
399 *s++ = 0x01;
400 _libssh2_store_str(&s, (char *)password, password_len);
401 _libssh2_store_u32(&s,
402 session->userauth_pswd_newpw_len);
403 /* send session->userauth_pswd_newpw separately */
404
405 session->userauth_pswd_state = libssh2_NB_state_sent2;
406 }
407
408 if(session->userauth_pswd_state ==
409 libssh2_NB_state_sent2) {
410 rc = _libssh2_transport_send(session,
411 session->userauth_pswd_data,
412 session->userauth_pswd_data_len,
413 (unsigned char *)
414 session->userauth_pswd_newpw,
415 session->userauth_pswd_newpw_len);
416 if(rc == LIBSSH2_ERROR_EAGAIN) {
417 return _libssh2_error(session,
418 LIBSSH2_ERROR_EAGAIN,
419 "Would block waiting");
420 }
421
422 /* free the allocated packets again */
423 LIBSSH2_FREE(session, session->userauth_pswd_data);
424 session->userauth_pswd_data = NULL;
425 LIBSSH2_FREE(session, session->userauth_pswd_newpw);
426 session->userauth_pswd_newpw = NULL;
427
428 if(rc) {
429 return _libssh2_error(session,
430 LIBSSH2_ERROR_SOCKET_SEND,
431 "Unable to send userauth "
432 "password-change request");
433 }
434
435 /*
436 * Ugliest use of goto ever. Blame it on the
437 * askN => requirev migration.
438 */
439 session->userauth_pswd_state = libssh2_NB_state_sent;
440 goto password_response;
441 }
442 }
443 }
444 else {
445 session->userauth_pswd_state = libssh2_NB_state_idle;
446 return _libssh2_error(session, LIBSSH2_ERROR_PASSWORD_EXPIRED,
447 "Password Expired, and no callback "
448 "specified");
449 }
450 }
451 }
452
453 /* FAILURE */
454 LIBSSH2_FREE(session, session->userauth_pswd_data);
455 session->userauth_pswd_data = NULL;
456 session->userauth_pswd_state = libssh2_NB_state_idle;
457
458 return _libssh2_error(session, LIBSSH2_ERROR_AUTHENTICATION_FAILED,
459 "Authentication failed");
460 }
461
462 /*
463 * libssh2_userauth_password_ex
464 *
465 * Plain ol' login
466 */
467
468 LIBSSH2_API int
libssh2_userauth_password_ex(LIBSSH2_SESSION * session,const char * username,unsigned int username_len,const char * password,unsigned int password_len,LIBSSH2_PASSWD_CHANGEREQ_FUNC ((* passwd_change_cb)))469 libssh2_userauth_password_ex(LIBSSH2_SESSION *session, const char *username,
470 unsigned int username_len, const char *password,
471 unsigned int password_len,
472 LIBSSH2_PASSWD_CHANGEREQ_FUNC
473 ((*passwd_change_cb)))
474 {
475 int rc;
476 BLOCK_ADJUST(rc, session,
477 userauth_password(session, username, username_len,
478 (unsigned char *)password, password_len,
479 passwd_change_cb));
480 return rc;
481 }
482
483 static int
memory_read_publickey(LIBSSH2_SESSION * session,unsigned char ** method,size_t * method_len,unsigned char ** pubkeydata,size_t * pubkeydata_len,const char * pubkeyfiledata,size_t pubkeyfiledata_len)484 memory_read_publickey(LIBSSH2_SESSION * session, unsigned char **method,
485 size_t *method_len,
486 unsigned char **pubkeydata,
487 size_t *pubkeydata_len,
488 const char *pubkeyfiledata,
489 size_t pubkeyfiledata_len)
490 {
491 unsigned char *pubkey = NULL, *sp1, *sp2, *tmp;
492 size_t pubkey_len = pubkeyfiledata_len;
493 unsigned int tmp_len;
494
495 if(pubkeyfiledata_len <= 1) {
496 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
497 "Invalid data in public key file");
498 }
499
500 pubkey = LIBSSH2_ALLOC(session, pubkeyfiledata_len);
501 if(!pubkey) {
502 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
503 "Unable to allocate memory for public key data");
504 }
505
506 memcpy(pubkey, pubkeyfiledata, pubkeyfiledata_len);
507
508 /*
509 * Remove trailing whitespace
510 */
511 while(pubkey_len && isspace(pubkey[pubkey_len - 1]))
512 pubkey_len--;
513
514 if(!pubkey_len) {
515 LIBSSH2_FREE(session, pubkey);
516 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
517 "Missing public key data");
518 }
519
520 sp1 = memchr(pubkey, ' ', pubkey_len);
521 if(sp1 == NULL) {
522 LIBSSH2_FREE(session, pubkey);
523 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
524 "Invalid public key data");
525 }
526
527 sp1++;
528
529 sp2 = memchr(sp1, ' ', pubkey_len - (sp1 - pubkey));
530 if(sp2 == NULL) {
531 /* Assume that the id string is missing, but that it's okay */
532 sp2 = pubkey + pubkey_len;
533 }
534
535 if(libssh2_base64_decode(session, (char **) &tmp, &tmp_len,
536 (char *) sp1, sp2 - sp1)) {
537 LIBSSH2_FREE(session, pubkey);
538 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
539 "Invalid key data, not base64 encoded");
540 }
541
542 /* Wasting some bytes here (okay, more than some), but since it's likely
543 * to be freed soon anyway, we'll just avoid the extra free/alloc and call
544 * it a wash
545 */
546 *method = pubkey;
547 *method_len = sp1 - pubkey - 1;
548
549 *pubkeydata = tmp;
550 *pubkeydata_len = tmp_len;
551
552 return 0;
553 }
554
555 /*
556 * file_read_publickey
557 *
558 * Read a public key from an id_???.pub style file
559 *
560 * Returns an allocated string containing the decoded key in *pubkeydata
561 * on success.
562 * Returns an allocated string containing the key method (e.g. "ssh-dss")
563 * in method on success.
564 */
565 static int
file_read_publickey(LIBSSH2_SESSION * session,unsigned char ** method,size_t * method_len,unsigned char ** pubkeydata,size_t * pubkeydata_len,const char * pubkeyfile)566 file_read_publickey(LIBSSH2_SESSION * session, unsigned char **method,
567 size_t *method_len,
568 unsigned char **pubkeydata,
569 size_t *pubkeydata_len,
570 const char *pubkeyfile)
571 {
572 FILE *fd;
573 char c;
574 unsigned char *pubkey = NULL, *sp1, *sp2, *tmp;
575 size_t pubkey_len = 0, sp_len;
576 unsigned int tmp_len;
577
578 _libssh2_debug(session, LIBSSH2_TRACE_AUTH, "Loading public key file: %s",
579 pubkeyfile);
580 /* Read Public Key */
581 fd = fopen(pubkeyfile, FOPEN_READTEXT);
582 if(!fd) {
583 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
584 "Unable to open public key file");
585 }
586 while(!feof(fd) && 1 == fread(&c, 1, 1, fd) && c != '\r' && c != '\n') {
587 pubkey_len++;
588 }
589 rewind(fd);
590
591 if(pubkey_len <= 1) {
592 fclose(fd);
593 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
594 "Invalid data in public key file");
595 }
596
597 pubkey = LIBSSH2_ALLOC(session, pubkey_len);
598 if(!pubkey) {
599 fclose(fd);
600 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
601 "Unable to allocate memory for public key data");
602 }
603 if(fread(pubkey, 1, pubkey_len, fd) != pubkey_len) {
604 LIBSSH2_FREE(session, pubkey);
605 fclose(fd);
606 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
607 "Unable to read public key from file");
608 }
609 fclose(fd);
610 /*
611 * Remove trailing whitespace
612 */
613 while(pubkey_len && isspace(pubkey[pubkey_len - 1])) {
614 pubkey_len--;
615 }
616
617 if(!pubkey_len) {
618 LIBSSH2_FREE(session, pubkey);
619 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
620 "Missing public key data");
621 }
622
623 sp1 = memchr(pubkey, ' ', pubkey_len);
624 if(sp1 == NULL) {
625 LIBSSH2_FREE(session, pubkey);
626 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
627 "Invalid public key data");
628 }
629
630 sp1++;
631
632 sp_len = sp1 > pubkey ? (sp1 - pubkey) : 0;
633 sp2 = memchr(sp1, ' ', pubkey_len - sp_len);
634 if(sp2 == NULL) {
635 /* Assume that the id string is missing, but that it's okay */
636 sp2 = pubkey + pubkey_len;
637 }
638
639 if(libssh2_base64_decode(session, (char **) &tmp, &tmp_len,
640 (char *) sp1, sp2 - sp1)) {
641 LIBSSH2_FREE(session, pubkey);
642 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
643 "Invalid key data, not base64 encoded");
644 }
645
646 /* Wasting some bytes here (okay, more than some), but since it's likely
647 * to be freed soon anyway, we'll just avoid the extra free/alloc and call
648 * it a wash */
649 *method = pubkey;
650 *method_len = sp1 - pubkey - 1;
651
652 *pubkeydata = tmp;
653 *pubkeydata_len = tmp_len;
654
655 return 0;
656 }
657
658 static int
memory_read_privatekey(LIBSSH2_SESSION * session,const LIBSSH2_HOSTKEY_METHOD ** hostkey_method,void ** hostkey_abstract,const unsigned char * method,int method_len,const char * privkeyfiledata,size_t privkeyfiledata_len,const char * passphrase)659 memory_read_privatekey(LIBSSH2_SESSION * session,
660 const LIBSSH2_HOSTKEY_METHOD ** hostkey_method,
661 void **hostkey_abstract,
662 const unsigned char *method, int method_len,
663 const char *privkeyfiledata, size_t privkeyfiledata_len,
664 const char *passphrase)
665 {
666 const LIBSSH2_HOSTKEY_METHOD **hostkey_methods_avail =
667 libssh2_hostkey_methods();
668
669 *hostkey_method = NULL;
670 *hostkey_abstract = NULL;
671 while(*hostkey_methods_avail && (*hostkey_methods_avail)->name) {
672 if((*hostkey_methods_avail)->initPEMFromMemory
673 && strncmp((*hostkey_methods_avail)->name, (const char *) method,
674 method_len) == 0) {
675 *hostkey_method = *hostkey_methods_avail;
676 break;
677 }
678 hostkey_methods_avail++;
679 }
680 if(!*hostkey_method) {
681 return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NONE,
682 "No handler for specified private key");
683 }
684
685 if((*hostkey_method)->
686 initPEMFromMemory(session, privkeyfiledata, privkeyfiledata_len,
687 (unsigned char *) passphrase,
688 hostkey_abstract)) {
689 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
690 "Unable to initialize private key from file");
691 }
692
693 return 0;
694 }
695
696 /* libssh2_file_read_privatekey
697 * Read a PEM encoded private key from an id_??? style file
698 */
699 static int
file_read_privatekey(LIBSSH2_SESSION * session,const LIBSSH2_HOSTKEY_METHOD ** hostkey_method,void ** hostkey_abstract,const unsigned char * method,int method_len,const char * privkeyfile,const char * passphrase)700 file_read_privatekey(LIBSSH2_SESSION * session,
701 const LIBSSH2_HOSTKEY_METHOD ** hostkey_method,
702 void **hostkey_abstract,
703 const unsigned char *method, int method_len,
704 const char *privkeyfile, const char *passphrase)
705 {
706 const LIBSSH2_HOSTKEY_METHOD **hostkey_methods_avail =
707 libssh2_hostkey_methods();
708
709 _libssh2_debug(session, LIBSSH2_TRACE_AUTH, "Loading private key file: %s",
710 privkeyfile);
711 *hostkey_method = NULL;
712 *hostkey_abstract = NULL;
713 while(*hostkey_methods_avail && (*hostkey_methods_avail)->name) {
714 if((*hostkey_methods_avail)->initPEM
715 && strncmp((*hostkey_methods_avail)->name, (const char *) method,
716 method_len) == 0) {
717 *hostkey_method = *hostkey_methods_avail;
718 break;
719 }
720 hostkey_methods_avail++;
721 }
722 if(!*hostkey_method) {
723 return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NONE,
724 "No handler for specified private key");
725 }
726
727 if((*hostkey_method)->
728 initPEM(session, privkeyfile, (unsigned char *) passphrase,
729 hostkey_abstract)) {
730 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
731 "Unable to initialize private key from file");
732 }
733
734 return 0;
735 }
736
737 struct privkey_file {
738 const char *filename;
739 const char *passphrase;
740 };
741
742 static int
sign_frommemory(LIBSSH2_SESSION * session,unsigned char ** sig,size_t * sig_len,const unsigned char * data,size_t data_len,void ** abstract)743 sign_frommemory(LIBSSH2_SESSION *session, unsigned char **sig, size_t *sig_len,
744 const unsigned char *data, size_t data_len, void **abstract)
745 {
746 struct privkey_file *pk_file = (struct privkey_file *) (*abstract);
747 const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
748 void *hostkey_abstract;
749 struct iovec datavec;
750 int rc;
751
752 rc = memory_read_privatekey(session, &privkeyobj, &hostkey_abstract,
753 session->userauth_pblc_method,
754 session->userauth_pblc_method_len,
755 pk_file->filename,
756 strlen(pk_file->filename),
757 pk_file->passphrase);
758 if(rc)
759 return rc;
760
761 libssh2_prepare_iovec(&datavec, 1);
762 datavec.iov_base = (void *)data;
763 datavec.iov_len = data_len;
764
765 if(privkeyobj->signv(session, sig, sig_len, 1, &datavec,
766 &hostkey_abstract)) {
767 if(privkeyobj->dtor) {
768 privkeyobj->dtor(session, &hostkey_abstract);
769 }
770 return -1;
771 }
772
773 if(privkeyobj->dtor) {
774 privkeyobj->dtor(session, &hostkey_abstract);
775 }
776 return 0;
777 }
778
779 static int
sign_fromfile(LIBSSH2_SESSION * session,unsigned char ** sig,size_t * sig_len,const unsigned char * data,size_t data_len,void ** abstract)780 sign_fromfile(LIBSSH2_SESSION *session, unsigned char **sig, size_t *sig_len,
781 const unsigned char *data, size_t data_len, void **abstract)
782 {
783 struct privkey_file *privkey_file = (struct privkey_file *) (*abstract);
784 const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
785 void *hostkey_abstract;
786 struct iovec datavec;
787 int rc;
788
789 rc = file_read_privatekey(session, &privkeyobj, &hostkey_abstract,
790 session->userauth_pblc_method,
791 session->userauth_pblc_method_len,
792 privkey_file->filename,
793 privkey_file->passphrase);
794 if(rc)
795 return rc;
796
797 libssh2_prepare_iovec(&datavec, 1);
798 datavec.iov_base = (void *)data;
799 datavec.iov_len = data_len;
800
801 if(privkeyobj->signv(session, sig, sig_len, 1, &datavec,
802 &hostkey_abstract)) {
803 if(privkeyobj->dtor) {
804 privkeyobj->dtor(session, &hostkey_abstract);
805 }
806 return -1;
807 }
808
809 if(privkeyobj->dtor) {
810 privkeyobj->dtor(session, &hostkey_abstract);
811 }
812 return 0;
813 }
814
815
816
817 /* userauth_hostbased_fromfile
818 * Authenticate using a keypair found in the named files
819 */
820 static int
userauth_hostbased_fromfile(LIBSSH2_SESSION * session,const char * username,size_t username_len,const char * publickey,const char * privatekey,const char * passphrase,const char * hostname,size_t hostname_len,const char * local_username,size_t local_username_len)821 userauth_hostbased_fromfile(LIBSSH2_SESSION *session,
822 const char *username, size_t username_len,
823 const char *publickey, const char *privatekey,
824 const char *passphrase, const char *hostname,
825 size_t hostname_len,
826 const char *local_username,
827 size_t local_username_len)
828 {
829 int rc;
830
831 #if !LIBSSH2_RSA
832 return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NOT_SUPPORTED,
833 "RSA is not supported by crypto backend");
834 #endif
835
836 if(session->userauth_host_state == libssh2_NB_state_idle) {
837 const LIBSSH2_HOSTKEY_METHOD *privkeyobj;
838 unsigned char *pubkeydata = NULL;
839 unsigned char *sig = NULL;
840 size_t pubkeydata_len = 0;
841 size_t sig_len = 0;
842 void *abstract;
843 unsigned char buf[5];
844 struct iovec datavec[4];
845
846 /* Zero the whole thing out */
847 memset(&session->userauth_host_packet_requirev_state, 0,
848 sizeof(session->userauth_host_packet_requirev_state));
849
850 if(publickey) {
851 rc = file_read_publickey(session, &session->userauth_host_method,
852 &session->userauth_host_method_len,
853 &pubkeydata, &pubkeydata_len, publickey);
854 if(rc)
855 /* Note: file_read_publickey() calls _libssh2_error() */
856 return rc;
857 }
858 else {
859 /* Compute public key from private key. */
860 rc = _libssh2_pub_priv_keyfile(session,
861 &session->userauth_host_method,
862 &session->userauth_host_method_len,
863 &pubkeydata, &pubkeydata_len,
864 privatekey, passphrase);
865 if(rc)
866 /* libssh2_pub_priv_keyfile calls _libssh2_error() */
867 return rc;
868 }
869
870 /*
871 * 52 = packet_type(1) + username_len(4) + servicename_len(4) +
872 * service_name(14)"ssh-connection" + authmethod_len(4) +
873 * authmethod(9)"hostbased" + method_len(4) + pubkeydata_len(4) +
874 * hostname_len(4) + local_username_len(4)
875 */
876 session->userauth_host_packet_len =
877 username_len + session->userauth_host_method_len + hostname_len +
878 local_username_len + pubkeydata_len + 52;
879
880 /*
881 * Preallocate space for an overall length, method name again,
882 * and the signature, which won't be any larger than the size of
883 * the publickeydata itself
884 */
885 session->userauth_host_s = session->userauth_host_packet =
886 LIBSSH2_ALLOC(session,
887 session->userauth_host_packet_len + 4 +
888 (4 + session->userauth_host_method_len) +
889 (4 + pubkeydata_len));
890 if(!session->userauth_host_packet) {
891 LIBSSH2_FREE(session, session->userauth_host_method);
892 session->userauth_host_method = NULL;
893 LIBSSH2_FREE(session, pubkeydata);
894 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
895 "Out of memory");
896 }
897
898 *(session->userauth_host_s++) = SSH_MSG_USERAUTH_REQUEST;
899 _libssh2_store_str(&session->userauth_host_s, username, username_len);
900 _libssh2_store_str(&session->userauth_host_s, "ssh-connection", 14);
901 _libssh2_store_str(&session->userauth_host_s, "hostbased", 9);
902 _libssh2_store_str(&session->userauth_host_s,
903 (const char *)session->userauth_host_method,
904 session->userauth_host_method_len);
905 _libssh2_store_str(&session->userauth_host_s, (const char *)pubkeydata,
906 pubkeydata_len);
907 LIBSSH2_FREE(session, pubkeydata);
908 _libssh2_store_str(&session->userauth_host_s, hostname, hostname_len);
909 _libssh2_store_str(&session->userauth_host_s, local_username,
910 local_username_len);
911
912 rc = file_read_privatekey(session, &privkeyobj, &abstract,
913 session->userauth_host_method,
914 session->userauth_host_method_len,
915 privatekey, passphrase);
916 if(rc) {
917 /* Note: file_read_privatekey() calls _libssh2_error() */
918 LIBSSH2_FREE(session, session->userauth_host_method);
919 session->userauth_host_method = NULL;
920 LIBSSH2_FREE(session, session->userauth_host_packet);
921 session->userauth_host_packet = NULL;
922 return rc;
923 }
924
925 _libssh2_htonu32(buf, session->session_id_len);
926 libssh2_prepare_iovec(datavec, 4);
927 datavec[0].iov_base = (void *)buf;
928 datavec[0].iov_len = 4;
929 datavec[1].iov_base = (void *)session->session_id;
930 datavec[1].iov_len = session->session_id_len;
931 datavec[2].iov_base = (void *)session->userauth_host_packet;
932 datavec[2].iov_len = session->userauth_host_packet_len;
933
934 if(privkeyobj && privkeyobj->signv &&
935 privkeyobj->signv(session, &sig, &sig_len, 3,
936 datavec, &abstract)) {
937 LIBSSH2_FREE(session, session->userauth_host_method);
938 session->userauth_host_method = NULL;
939 LIBSSH2_FREE(session, session->userauth_host_packet);
940 session->userauth_host_packet = NULL;
941 if(privkeyobj->dtor) {
942 privkeyobj->dtor(session, &abstract);
943 }
944 return -1;
945 }
946
947 if(privkeyobj && privkeyobj->dtor) {
948 privkeyobj->dtor(session, &abstract);
949 }
950
951 if(sig_len > pubkeydata_len) {
952 unsigned char *newpacket;
953 /* Should *NEVER* happen, but...well.. better safe than sorry */
954 newpacket = LIBSSH2_REALLOC(session, session->userauth_host_packet,
955 session->userauth_host_packet_len + 4 +
956 (4 + session->userauth_host_method_len)
957 + (4 + sig_len)); /* PK sigblob */
958 if(!newpacket) {
959 LIBSSH2_FREE(session, sig);
960 LIBSSH2_FREE(session, session->userauth_host_packet);
961 session->userauth_host_packet = NULL;
962 LIBSSH2_FREE(session, session->userauth_host_method);
963 session->userauth_host_method = NULL;
964 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
965 "Failed allocating additional space for "
966 "userauth-hostbased packet");
967 }
968 session->userauth_host_packet = newpacket;
969 }
970
971 session->userauth_host_s =
972 session->userauth_host_packet + session->userauth_host_packet_len;
973
974 _libssh2_store_u32(&session->userauth_host_s,
975 4 + session->userauth_host_method_len +
976 4 + sig_len);
977 _libssh2_store_str(&session->userauth_host_s,
978 (const char *)session->userauth_host_method,
979 session->userauth_host_method_len);
980 LIBSSH2_FREE(session, session->userauth_host_method);
981 session->userauth_host_method = NULL;
982
983 _libssh2_store_str(&session->userauth_host_s, (const char *)sig,
984 sig_len);
985 LIBSSH2_FREE(session, sig);
986
987 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
988 "Attempting hostbased authentication");
989
990 session->userauth_host_state = libssh2_NB_state_created;
991 }
992
993 if(session->userauth_host_state == libssh2_NB_state_created) {
994 rc = _libssh2_transport_send(session, session->userauth_host_packet,
995 session->userauth_host_s -
996 session->userauth_host_packet,
997 NULL, 0);
998 if(rc == LIBSSH2_ERROR_EAGAIN) {
999 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1000 "Would block");
1001 }
1002 else if(rc) {
1003 LIBSSH2_FREE(session, session->userauth_host_packet);
1004 session->userauth_host_packet = NULL;
1005 session->userauth_host_state = libssh2_NB_state_idle;
1006 return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
1007 "Unable to send userauth-hostbased request");
1008 }
1009 LIBSSH2_FREE(session, session->userauth_host_packet);
1010 session->userauth_host_packet = NULL;
1011
1012 session->userauth_host_state = libssh2_NB_state_sent;
1013 }
1014
1015 if(session->userauth_host_state == libssh2_NB_state_sent) {
1016 static const unsigned char reply_codes[3] =
1017 { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE, 0 };
1018 size_t data_len;
1019 rc = _libssh2_packet_requirev(session, reply_codes,
1020 &session->userauth_host_data,
1021 &data_len, 0, NULL, 0,
1022 &session->
1023 userauth_host_packet_requirev_state);
1024 if(rc == LIBSSH2_ERROR_EAGAIN) {
1025 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1026 "Would block");
1027 }
1028
1029 session->userauth_host_state = libssh2_NB_state_idle;
1030 if(rc || data_len < 1) {
1031 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1032 "Auth failed");
1033 }
1034
1035 if(session->userauth_host_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
1036 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1037 "Hostbased authentication successful");
1038 /* We are us and we've proved it. */
1039 LIBSSH2_FREE(session, session->userauth_host_data);
1040 session->userauth_host_data = NULL;
1041 session->state |= LIBSSH2_STATE_AUTHENTICATED;
1042 return 0;
1043 }
1044 }
1045
1046 /* This public key is not allowed for this user on this server */
1047 LIBSSH2_FREE(session, session->userauth_host_data);
1048 session->userauth_host_data = NULL;
1049 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1050 "Invalid signature for supplied public key, or bad "
1051 "username/public key combination");
1052 }
1053
1054 /* libssh2_userauth_hostbased_fromfile_ex
1055 * Authenticate using a keypair found in the named files
1056 */
1057 LIBSSH2_API int
libssh2_userauth_hostbased_fromfile_ex(LIBSSH2_SESSION * session,const char * user,unsigned int user_len,const char * publickey,const char * privatekey,const char * passphrase,const char * host,unsigned int host_len,const char * localuser,unsigned int localuser_len)1058 libssh2_userauth_hostbased_fromfile_ex(LIBSSH2_SESSION *session,
1059 const char *user,
1060 unsigned int user_len,
1061 const char *publickey,
1062 const char *privatekey,
1063 const char *passphrase,
1064 const char *host,
1065 unsigned int host_len,
1066 const char *localuser,
1067 unsigned int localuser_len)
1068 {
1069 int rc;
1070 BLOCK_ADJUST(rc, session,
1071 userauth_hostbased_fromfile(session, user, user_len,
1072 publickey, privatekey,
1073 passphrase, host, host_len,
1074 localuser, localuser_len));
1075 return rc;
1076 }
1077
1078
1079
1080 int
_libssh2_userauth_publickey(LIBSSH2_SESSION * session,const char * username,unsigned int username_len,const unsigned char * pubkeydata,unsigned long pubkeydata_len,LIBSSH2_USERAUTH_PUBLICKEY_SIGN_FUNC ((* sign_callback)),void * abstract)1081 _libssh2_userauth_publickey(LIBSSH2_SESSION *session,
1082 const char *username,
1083 unsigned int username_len,
1084 const unsigned char *pubkeydata,
1085 unsigned long pubkeydata_len,
1086 LIBSSH2_USERAUTH_PUBLICKEY_SIGN_FUNC
1087 ((*sign_callback)),
1088 void *abstract)
1089 {
1090 unsigned char reply_codes[4] =
1091 { SSH_MSG_USERAUTH_SUCCESS, SSH_MSG_USERAUTH_FAILURE,
1092 SSH_MSG_USERAUTH_PK_OK, 0
1093 };
1094 int rc;
1095 unsigned char *s;
1096
1097 if(session->userauth_pblc_state == libssh2_NB_state_idle) {
1098
1099 /*
1100 * The call to _libssh2_ntohu32 later relies on pubkeydata having at
1101 * least 4 valid bytes containing the length of the method name.
1102 */
1103 if(pubkeydata_len < 4)
1104 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1105 "Invalid public key, too short");
1106
1107 /* Zero the whole thing out */
1108 memset(&session->userauth_pblc_packet_requirev_state, 0,
1109 sizeof(session->userauth_pblc_packet_requirev_state));
1110
1111 /*
1112 * As an optimisation, userauth_publickey_fromfile reuses a
1113 * previously allocated copy of the method name to avoid an extra
1114 * allocation/free.
1115 * For other uses, we allocate and populate it here.
1116 */
1117 if(!session->userauth_pblc_method) {
1118 session->userauth_pblc_method_len = _libssh2_ntohu32(pubkeydata);
1119
1120 if(session->userauth_pblc_method_len > pubkeydata_len - 4)
1121 /* the method length simply cannot be longer than the entire
1122 passed in data, so we use this to detect crazy input
1123 data */
1124 return _libssh2_error(session,
1125 LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1126 "Invalid public key");
1127
1128 session->userauth_pblc_method =
1129 LIBSSH2_ALLOC(session, session->userauth_pblc_method_len);
1130 if(!session->userauth_pblc_method) {
1131 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1132 "Unable to allocate memory "
1133 "for public key data");
1134 }
1135 memcpy(session->userauth_pblc_method, pubkeydata + 4,
1136 session->userauth_pblc_method_len);
1137 }
1138 /*
1139 * The length of the method name read from plaintext prefix in the
1140 * file must match length embedded in the key.
1141 * TODO: The data should match too but we don't check that. Should we?
1142 */
1143 else if(session->userauth_pblc_method_len !=
1144 _libssh2_ntohu32(pubkeydata))
1145 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1146 "Invalid public key");
1147
1148 /*
1149 * 45 = packet_type(1) + username_len(4) + servicename_len(4) +
1150 * service_name(14)"ssh-connection" + authmethod_len(4) +
1151 * authmethod(9)"publickey" + sig_included(1)'\0' + algmethod_len(4) +
1152 * publickey_len(4)
1153 */
1154 session->userauth_pblc_packet_len =
1155 username_len + session->userauth_pblc_method_len + pubkeydata_len +
1156 45;
1157
1158 /*
1159 * Preallocate space for an overall length, method name again, and the
1160 * signature, which won't be any larger than the size of the
1161 * publickeydata itself.
1162 *
1163 * Note that the 'pubkeydata_len' extra bytes allocated here will not
1164 * be used in this first send, but will be used in the later one where
1165 * this same allocation is re-used.
1166 */
1167 s = session->userauth_pblc_packet =
1168 LIBSSH2_ALLOC(session,
1169 session->userauth_pblc_packet_len + 4 +
1170 (4 + session->userauth_pblc_method_len)
1171 + (4 + pubkeydata_len));
1172 if(!session->userauth_pblc_packet) {
1173 LIBSSH2_FREE(session, session->userauth_pblc_method);
1174 session->userauth_pblc_method = NULL;
1175 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1176 "Out of memory");
1177 }
1178
1179 *s++ = SSH_MSG_USERAUTH_REQUEST;
1180 _libssh2_store_str(&s, username, username_len);
1181 _libssh2_store_str(&s, "ssh-connection", 14);
1182 _libssh2_store_str(&s, "publickey", 9);
1183
1184 session->userauth_pblc_b = s;
1185 /* Not sending signature with *this* packet */
1186 *s++ = 0;
1187
1188 _libssh2_store_str(&s, (const char *)session->userauth_pblc_method,
1189 session->userauth_pblc_method_len);
1190 _libssh2_store_str(&s, (const char *)pubkeydata, pubkeydata_len);
1191
1192 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1193 "Attempting publickey authentication");
1194
1195 session->userauth_pblc_state = libssh2_NB_state_created;
1196 }
1197
1198 if(session->userauth_pblc_state == libssh2_NB_state_created) {
1199 rc = _libssh2_transport_send(session, session->userauth_pblc_packet,
1200 session->userauth_pblc_packet_len,
1201 NULL, 0);
1202 if(rc == LIBSSH2_ERROR_EAGAIN)
1203 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1204 "Would block");
1205 else if(rc) {
1206 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1207 session->userauth_pblc_packet = NULL;
1208 LIBSSH2_FREE(session, session->userauth_pblc_method);
1209 session->userauth_pblc_method = NULL;
1210 session->userauth_pblc_state = libssh2_NB_state_idle;
1211 return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
1212 "Unable to send userauth-publickey request");
1213 }
1214
1215 session->userauth_pblc_state = libssh2_NB_state_sent;
1216 }
1217
1218 if(session->userauth_pblc_state == libssh2_NB_state_sent) {
1219 rc = _libssh2_packet_requirev(session, reply_codes,
1220 &session->userauth_pblc_data,
1221 &session->userauth_pblc_data_len, 0,
1222 NULL, 0,
1223 &session->
1224 userauth_pblc_packet_requirev_state);
1225 if(rc == LIBSSH2_ERROR_EAGAIN) {
1226 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1227 "Would block");
1228 }
1229 else if(rc || (session->userauth_pblc_data_len < 1)) {
1230 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1231 session->userauth_pblc_packet = NULL;
1232 LIBSSH2_FREE(session, session->userauth_pblc_method);
1233 session->userauth_pblc_method = NULL;
1234 session->userauth_pblc_state = libssh2_NB_state_idle;
1235 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1236 "Waiting for USERAUTH response");
1237 }
1238
1239 if(session->userauth_pblc_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
1240 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1241 "Pubkey authentication prematurely successful");
1242 /*
1243 * God help any SSH server that allows an UNVERIFIED
1244 * public key to validate the user
1245 */
1246 LIBSSH2_FREE(session, session->userauth_pblc_data);
1247 session->userauth_pblc_data = NULL;
1248 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1249 session->userauth_pblc_packet = NULL;
1250 LIBSSH2_FREE(session, session->userauth_pblc_method);
1251 session->userauth_pblc_method = NULL;
1252 session->state |= LIBSSH2_STATE_AUTHENTICATED;
1253 session->userauth_pblc_state = libssh2_NB_state_idle;
1254 return 0;
1255 }
1256
1257 if(session->userauth_pblc_data[0] == SSH_MSG_USERAUTH_FAILURE) {
1258 /* This public key is not allowed for this user on this server */
1259 LIBSSH2_FREE(session, session->userauth_pblc_data);
1260 session->userauth_pblc_data = NULL;
1261 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1262 session->userauth_pblc_packet = NULL;
1263 LIBSSH2_FREE(session, session->userauth_pblc_method);
1264 session->userauth_pblc_method = NULL;
1265 session->userauth_pblc_state = libssh2_NB_state_idle;
1266 return _libssh2_error(session, LIBSSH2_ERROR_AUTHENTICATION_FAILED,
1267 "Username/PublicKey combination invalid");
1268 }
1269
1270 /* Semi-Success! */
1271 LIBSSH2_FREE(session, session->userauth_pblc_data);
1272 session->userauth_pblc_data = NULL;
1273
1274 *session->userauth_pblc_b = 0x01;
1275 session->userauth_pblc_state = libssh2_NB_state_sent1;
1276 }
1277
1278 if(session->userauth_pblc_state == libssh2_NB_state_sent1) {
1279 unsigned char *buf;
1280 unsigned char *sig;
1281 size_t sig_len;
1282
1283 s = buf = LIBSSH2_ALLOC(session, 4 + session->session_id_len
1284 + session->userauth_pblc_packet_len);
1285 if(!buf) {
1286 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1287 "Unable to allocate memory for "
1288 "userauth-publickey signed data");
1289 }
1290
1291 _libssh2_store_str(&s, (const char *)session->session_id,
1292 session->session_id_len);
1293
1294 memcpy(s, session->userauth_pblc_packet,
1295 session->userauth_pblc_packet_len);
1296 s += session->userauth_pblc_packet_len;
1297
1298 rc = sign_callback(session, &sig, &sig_len, buf, s - buf, abstract);
1299 LIBSSH2_FREE(session, buf);
1300 if(rc == LIBSSH2_ERROR_EAGAIN) {
1301 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1302 "Would block");
1303 }
1304 else if(rc) {
1305 LIBSSH2_FREE(session, session->userauth_pblc_method);
1306 session->userauth_pblc_method = NULL;
1307 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1308 session->userauth_pblc_packet = NULL;
1309 session->userauth_pblc_state = libssh2_NB_state_idle;
1310 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1311 "Callback returned error");
1312 }
1313
1314 /*
1315 * If this function was restarted, pubkeydata_len might still be 0
1316 * which will cause an unnecessary but harmless realloc here.
1317 */
1318 if(sig_len > pubkeydata_len) {
1319 unsigned char *newpacket;
1320 /* Should *NEVER* happen, but...well.. better safe than sorry */
1321 newpacket = LIBSSH2_REALLOC(session,
1322 session->userauth_pblc_packet,
1323 session->userauth_pblc_packet_len + 4 +
1324 (4 + session->userauth_pblc_method_len)
1325 + (4 + sig_len)); /* PK sigblob */
1326 if(!newpacket) {
1327 LIBSSH2_FREE(session, sig);
1328 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1329 session->userauth_pblc_packet = NULL;
1330 LIBSSH2_FREE(session, session->userauth_pblc_method);
1331 session->userauth_pblc_method = NULL;
1332 session->userauth_pblc_state = libssh2_NB_state_idle;
1333 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1334 "Failed allocating additional space for "
1335 "userauth-publickey packet");
1336 }
1337 session->userauth_pblc_packet = newpacket;
1338 }
1339
1340 s = session->userauth_pblc_packet + session->userauth_pblc_packet_len;
1341 session->userauth_pblc_b = NULL;
1342
1343 _libssh2_store_u32(&s,
1344 4 + session->userauth_pblc_method_len + 4 +
1345 sig_len);
1346 _libssh2_store_str(&s, (const char *)session->userauth_pblc_method,
1347 session->userauth_pblc_method_len);
1348
1349 LIBSSH2_FREE(session, session->userauth_pblc_method);
1350 session->userauth_pblc_method = NULL;
1351
1352 _libssh2_store_str(&s, (const char *)sig, sig_len);
1353 LIBSSH2_FREE(session, sig);
1354
1355 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1356 "Attempting publickey authentication -- phase 2");
1357
1358 session->userauth_pblc_s = s;
1359 session->userauth_pblc_state = libssh2_NB_state_sent2;
1360 }
1361
1362 if(session->userauth_pblc_state == libssh2_NB_state_sent2) {
1363 rc = _libssh2_transport_send(session, session->userauth_pblc_packet,
1364 session->userauth_pblc_s -
1365 session->userauth_pblc_packet,
1366 NULL, 0);
1367 if(rc == LIBSSH2_ERROR_EAGAIN) {
1368 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1369 "Would block");
1370 }
1371 else if(rc) {
1372 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1373 session->userauth_pblc_packet = NULL;
1374 session->userauth_pblc_state = libssh2_NB_state_idle;
1375 return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
1376 "Unable to send userauth-publickey request");
1377 }
1378 LIBSSH2_FREE(session, session->userauth_pblc_packet);
1379 session->userauth_pblc_packet = NULL;
1380
1381 session->userauth_pblc_state = libssh2_NB_state_sent3;
1382 }
1383
1384 /* PK_OK is no longer valid */
1385 reply_codes[2] = 0;
1386
1387 rc = _libssh2_packet_requirev(session, reply_codes,
1388 &session->userauth_pblc_data,
1389 &session->userauth_pblc_data_len, 0, NULL, 0,
1390 &session->userauth_pblc_packet_requirev_state);
1391 if(rc == LIBSSH2_ERROR_EAGAIN) {
1392 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1393 "Would block requesting userauth list");
1394 }
1395 else if(rc || session->userauth_pblc_data_len < 1) {
1396 session->userauth_pblc_state = libssh2_NB_state_idle;
1397 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1398 "Waiting for publickey USERAUTH response");
1399 }
1400
1401 if(session->userauth_pblc_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
1402 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1403 "Publickey authentication successful");
1404 /* We are us and we've proved it. */
1405 LIBSSH2_FREE(session, session->userauth_pblc_data);
1406 session->userauth_pblc_data = NULL;
1407 session->state |= LIBSSH2_STATE_AUTHENTICATED;
1408 session->userauth_pblc_state = libssh2_NB_state_idle;
1409 return 0;
1410 }
1411
1412 /* This public key is not allowed for this user on this server */
1413 LIBSSH2_FREE(session, session->userauth_pblc_data);
1414 session->userauth_pblc_data = NULL;
1415 session->userauth_pblc_state = libssh2_NB_state_idle;
1416 return _libssh2_error(session, LIBSSH2_ERROR_PUBLICKEY_UNVERIFIED,
1417 "Invalid signature for supplied public key, or bad "
1418 "username/public key combination");
1419 }
1420
1421 /*
1422 * userauth_publickey_frommemory
1423 * Authenticate using a keypair from memory
1424 */
1425 static int
userauth_publickey_frommemory(LIBSSH2_SESSION * session,const char * username,size_t username_len,const char * publickeydata,size_t publickeydata_len,const char * privatekeydata,size_t privatekeydata_len,const char * passphrase)1426 userauth_publickey_frommemory(LIBSSH2_SESSION *session,
1427 const char *username,
1428 size_t username_len,
1429 const char *publickeydata,
1430 size_t publickeydata_len,
1431 const char *privatekeydata,
1432 size_t privatekeydata_len,
1433 const char *passphrase)
1434 {
1435 unsigned char *pubkeydata = NULL;
1436 size_t pubkeydata_len = 0;
1437 struct privkey_file privkey_file;
1438 void *abstract = &privkey_file;
1439 int rc;
1440
1441 #if !LIBSSH2_RSA
1442 return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NOT_SUPPORTED,
1443 "RSA is not supported by crypto backend");
1444 #endif
1445
1446 privkey_file.filename = privatekeydata;
1447 privkey_file.passphrase = passphrase;
1448
1449 if(session->userauth_pblc_state == libssh2_NB_state_idle) {
1450 if(publickeydata_len && publickeydata) {
1451 rc = memory_read_publickey(session, &session->userauth_pblc_method,
1452 &session->userauth_pblc_method_len,
1453 &pubkeydata, &pubkeydata_len,
1454 publickeydata, publickeydata_len);
1455 if(rc)
1456 return rc;
1457 }
1458 else if(privatekeydata_len && privatekeydata) {
1459 /* Compute public key from private key. */
1460 if(_libssh2_pub_priv_keyfilememory(session,
1461 &session->userauth_pblc_method,
1462 &session->userauth_pblc_method_len,
1463 &pubkeydata, &pubkeydata_len,
1464 privatekeydata, privatekeydata_len,
1465 passphrase))
1466 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
1467 "Unable to extract public key "
1468 "from private key.");
1469 }
1470 else {
1471 return _libssh2_error(session, LIBSSH2_ERROR_FILE,
1472 "Invalid data in public and private key.");
1473 }
1474 }
1475
1476 rc = _libssh2_userauth_publickey(session, username, username_len,
1477 pubkeydata, pubkeydata_len,
1478 sign_frommemory, &abstract);
1479 if(pubkeydata)
1480 LIBSSH2_FREE(session, pubkeydata);
1481
1482 return rc;
1483 }
1484
1485 /*
1486 * userauth_publickey_fromfile
1487 * Authenticate using a keypair found in the named files
1488 */
1489 static int
userauth_publickey_fromfile(LIBSSH2_SESSION * session,const char * username,size_t username_len,const char * publickey,const char * privatekey,const char * passphrase)1490 userauth_publickey_fromfile(LIBSSH2_SESSION *session,
1491 const char *username,
1492 size_t username_len,
1493 const char *publickey,
1494 const char *privatekey,
1495 const char *passphrase)
1496 {
1497 unsigned char *pubkeydata = NULL;
1498 size_t pubkeydata_len = 0;
1499 struct privkey_file privkey_file;
1500 void *abstract = &privkey_file;
1501 int rc;
1502
1503 #if !LIBSSH2_RSA
1504 return _libssh2_error(session, LIBSSH2_ERROR_METHOD_NOT_SUPPORTED,
1505 "RSA is not supported by crypto backend");
1506 #endif
1507
1508 privkey_file.filename = privatekey;
1509 privkey_file.passphrase = passphrase;
1510
1511 if(session->userauth_pblc_state == libssh2_NB_state_idle) {
1512 if(publickey) {
1513 rc = file_read_publickey(session, &session->userauth_pblc_method,
1514 &session->userauth_pblc_method_len,
1515 &pubkeydata, &pubkeydata_len, publickey);
1516 if(rc)
1517 return rc;
1518 }
1519 else {
1520 /* Compute public key from private key. */
1521 rc = _libssh2_pub_priv_keyfile(session,
1522 &session->userauth_pblc_method,
1523 &session->userauth_pblc_method_len,
1524 &pubkeydata, &pubkeydata_len,
1525 privatekey, passphrase);
1526
1527 /* _libssh2_pub_priv_keyfile calls _libssh2_error() */
1528 if(rc)
1529 return rc;
1530 }
1531 }
1532
1533 rc = _libssh2_userauth_publickey(session, username, username_len,
1534 pubkeydata, pubkeydata_len,
1535 sign_fromfile, &abstract);
1536 if(pubkeydata)
1537 LIBSSH2_FREE(session, pubkeydata);
1538
1539 return rc;
1540 }
1541
1542 /* libssh2_userauth_publickey_frommemory
1543 * Authenticate using a keypair from memory
1544 */
1545 LIBSSH2_API int
libssh2_userauth_publickey_frommemory(LIBSSH2_SESSION * session,const char * user,size_t user_len,const char * publickeyfiledata,size_t publickeyfiledata_len,const char * privatekeyfiledata,size_t privatekeyfiledata_len,const char * passphrase)1546 libssh2_userauth_publickey_frommemory(LIBSSH2_SESSION *session,
1547 const char *user,
1548 size_t user_len,
1549 const char *publickeyfiledata,
1550 size_t publickeyfiledata_len,
1551 const char *privatekeyfiledata,
1552 size_t privatekeyfiledata_len,
1553 const char *passphrase)
1554 {
1555 int rc;
1556
1557 if(NULL == passphrase)
1558 /* if given a NULL pointer, make it point to a zero-length
1559 string to save us from having to check this all over */
1560 passphrase = "";
1561
1562 BLOCK_ADJUST(rc, session,
1563 userauth_publickey_frommemory(session, user, user_len,
1564 publickeyfiledata,
1565 publickeyfiledata_len,
1566 privatekeyfiledata,
1567 privatekeyfiledata_len,
1568 passphrase));
1569 return rc;
1570 }
1571
1572 /* libssh2_userauth_publickey_fromfile_ex
1573 * Authenticate using a keypair found in the named files
1574 */
1575 LIBSSH2_API int
libssh2_userauth_publickey_fromfile_ex(LIBSSH2_SESSION * session,const char * user,unsigned int user_len,const char * publickey,const char * privatekey,const char * passphrase)1576 libssh2_userauth_publickey_fromfile_ex(LIBSSH2_SESSION *session,
1577 const char *user,
1578 unsigned int user_len,
1579 const char *publickey,
1580 const char *privatekey,
1581 const char *passphrase)
1582 {
1583 int rc;
1584
1585 if(NULL == passphrase)
1586 /* if given a NULL pointer, make it point to a zero-length
1587 string to save us from having to check this all over */
1588 passphrase = "";
1589
1590 BLOCK_ADJUST(rc, session,
1591 userauth_publickey_fromfile(session, user, user_len,
1592 publickey, privatekey,
1593 passphrase));
1594 return rc;
1595 }
1596
1597 /* libssh2_userauth_publickey_ex
1598 * Authenticate using an external callback function
1599 */
1600 LIBSSH2_API int
libssh2_userauth_publickey(LIBSSH2_SESSION * session,const char * user,const unsigned char * pubkeydata,size_t pubkeydata_len,LIBSSH2_USERAUTH_PUBLICKEY_SIGN_FUNC ((* sign_callback)),void ** abstract)1601 libssh2_userauth_publickey(LIBSSH2_SESSION *session,
1602 const char *user,
1603 const unsigned char *pubkeydata,
1604 size_t pubkeydata_len,
1605 LIBSSH2_USERAUTH_PUBLICKEY_SIGN_FUNC
1606 ((*sign_callback)),
1607 void **abstract)
1608 {
1609 int rc;
1610
1611 if(!session)
1612 return LIBSSH2_ERROR_BAD_USE;
1613
1614 BLOCK_ADJUST(rc, session,
1615 _libssh2_userauth_publickey(session, user, strlen(user),
1616 pubkeydata, pubkeydata_len,
1617 sign_callback, abstract));
1618 return rc;
1619 }
1620
1621
1622
1623 /*
1624 * userauth_keyboard_interactive
1625 *
1626 * Authenticate using a challenge-response authentication
1627 */
1628 static int
userauth_keyboard_interactive(LIBSSH2_SESSION * session,const char * username,unsigned int username_len,LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC ((* response_callback)))1629 userauth_keyboard_interactive(LIBSSH2_SESSION * session,
1630 const char *username,
1631 unsigned int username_len,
1632 LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC
1633 ((*response_callback)))
1634 {
1635 unsigned char *s;
1636 int rc;
1637
1638 static const unsigned char reply_codes[4] = {
1639 SSH_MSG_USERAUTH_SUCCESS,
1640 SSH_MSG_USERAUTH_FAILURE, SSH_MSG_USERAUTH_INFO_REQUEST, 0
1641 };
1642 unsigned int language_tag_len;
1643 unsigned int i;
1644
1645 if(session->userauth_kybd_state == libssh2_NB_state_idle) {
1646 session->userauth_kybd_auth_name = NULL;
1647 session->userauth_kybd_auth_instruction = NULL;
1648 session->userauth_kybd_num_prompts = 0;
1649 session->userauth_kybd_auth_failure = 1;
1650 session->userauth_kybd_prompts = NULL;
1651 session->userauth_kybd_responses = NULL;
1652
1653 /* Zero the whole thing out */
1654 memset(&session->userauth_kybd_packet_requirev_state, 0,
1655 sizeof(session->userauth_kybd_packet_requirev_state));
1656
1657 session->userauth_kybd_packet_len =
1658 1 /* byte SSH_MSG_USERAUTH_REQUEST */
1659 + 4 + username_len /* string user name (ISO-10646 UTF-8, as
1660 defined in [RFC-3629]) */
1661 + 4 + 14 /* string service name (US-ASCII) */
1662 + 4 + 20 /* string "keyboard-interactive" (US-ASCII) */
1663 + 4 + 0 /* string language tag (as defined in
1664 [RFC-3066]) */
1665 + 4 + 0 /* string submethods (ISO-10646 UTF-8) */
1666 ;
1667
1668 session->userauth_kybd_data = s =
1669 LIBSSH2_ALLOC(session, session->userauth_kybd_packet_len);
1670 if(!s) {
1671 return _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1672 "Unable to allocate memory for "
1673 "keyboard-interactive authentication");
1674 }
1675
1676 *s++ = SSH_MSG_USERAUTH_REQUEST;
1677
1678 /* user name */
1679 _libssh2_store_str(&s, username, username_len);
1680
1681 /* service name */
1682 _libssh2_store_str(&s, "ssh-connection", sizeof("ssh-connection") - 1);
1683
1684 /* "keyboard-interactive" */
1685 _libssh2_store_str(&s, "keyboard-interactive",
1686 sizeof("keyboard-interactive") - 1);
1687 /* language tag */
1688 _libssh2_store_u32(&s, 0);
1689
1690 /* submethods */
1691 _libssh2_store_u32(&s, 0);
1692
1693 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1694 "Attempting keyboard-interactive authentication");
1695
1696 session->userauth_kybd_state = libssh2_NB_state_created;
1697 }
1698
1699 if(session->userauth_kybd_state == libssh2_NB_state_created) {
1700 rc = _libssh2_transport_send(session, session->userauth_kybd_data,
1701 session->userauth_kybd_packet_len,
1702 NULL, 0);
1703 if(rc == LIBSSH2_ERROR_EAGAIN) {
1704 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1705 "Would block");
1706 }
1707 else if(rc) {
1708 LIBSSH2_FREE(session, session->userauth_kybd_data);
1709 session->userauth_kybd_data = NULL;
1710 session->userauth_kybd_state = libssh2_NB_state_idle;
1711 return _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
1712 "Unable to send keyboard-interactive"
1713 " request");
1714 }
1715 LIBSSH2_FREE(session, session->userauth_kybd_data);
1716 session->userauth_kybd_data = NULL;
1717
1718 session->userauth_kybd_state = libssh2_NB_state_sent;
1719 }
1720
1721 for(;;) {
1722 if(session->userauth_kybd_state == libssh2_NB_state_sent) {
1723 rc = _libssh2_packet_requirev(session, reply_codes,
1724 &session->userauth_kybd_data,
1725 &session->userauth_kybd_data_len,
1726 0, NULL, 0,
1727 &session->
1728 userauth_kybd_packet_requirev_state);
1729 if(rc == LIBSSH2_ERROR_EAGAIN) {
1730 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
1731 "Would block");
1732 }
1733 else if(rc || session->userauth_kybd_data_len < 1) {
1734 session->userauth_kybd_state = libssh2_NB_state_idle;
1735 return _libssh2_error(session,
1736 LIBSSH2_ERROR_AUTHENTICATION_FAILED,
1737 "Waiting for keyboard "
1738 "USERAUTH response");
1739 }
1740
1741 if(session->userauth_kybd_data[0] == SSH_MSG_USERAUTH_SUCCESS) {
1742 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1743 "Keyboard-interactive "
1744 "authentication successful");
1745 LIBSSH2_FREE(session, session->userauth_kybd_data);
1746 session->userauth_kybd_data = NULL;
1747 session->state |= LIBSSH2_STATE_AUTHENTICATED;
1748 session->userauth_kybd_state = libssh2_NB_state_idle;
1749 return 0;
1750 }
1751
1752 if(session->userauth_kybd_data[0] == SSH_MSG_USERAUTH_FAILURE) {
1753 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1754 "Keyboard-interactive authentication failed");
1755 LIBSSH2_FREE(session, session->userauth_kybd_data);
1756 session->userauth_kybd_data = NULL;
1757 session->userauth_kybd_state = libssh2_NB_state_idle;
1758 return _libssh2_error(session,
1759 LIBSSH2_ERROR_AUTHENTICATION_FAILED,
1760 "Authentication failed "
1761 "(keyboard-interactive)");
1762 }
1763
1764 /* server requested PAM-like conversation */
1765 s = session->userauth_kybd_data + 1;
1766
1767 if(session->userauth_kybd_data_len >= 5) {
1768 /* string name (ISO-10646 UTF-8) */
1769 session->userauth_kybd_auth_name_len = _libssh2_ntohu32(s);
1770 s += 4;
1771 }
1772 else {
1773 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1774 "userauth keyboard data buffer too small"
1775 "to get length");
1776 goto cleanup;
1777 }
1778
1779 if(session->userauth_kybd_auth_name_len) {
1780 session->userauth_kybd_auth_name =
1781 LIBSSH2_ALLOC(session,
1782 session->userauth_kybd_auth_name_len);
1783 if(!session->userauth_kybd_auth_name) {
1784 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1785 "Unable to allocate memory for "
1786 "keyboard-interactive 'name' "
1787 "request field");
1788 goto cleanup;
1789 }
1790 if(s + session->userauth_list_data_len <=
1791 session->userauth_kybd_data +
1792 session->userauth_kybd_data_len) {
1793 memcpy(session->userauth_kybd_auth_name, s,
1794 session->userauth_kybd_auth_name_len);
1795 s += session->userauth_kybd_auth_name_len;
1796 }
1797 else {
1798 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1799 "userauth keyboard data buffer too small"
1800 "for auth name");
1801 goto cleanup;
1802 }
1803 }
1804
1805 if(s + 4 <= session->userauth_kybd_data +
1806 session->userauth_kybd_data_len) {
1807 /* string instruction (ISO-10646 UTF-8) */
1808 session->userauth_kybd_auth_instruction_len =
1809 _libssh2_ntohu32(s);
1810 s += 4;
1811 }
1812 else {
1813 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1814 "userauth keyboard data buffer too small"
1815 "for auth instruction length");
1816 goto cleanup;
1817 }
1818
1819 if(session->userauth_kybd_auth_instruction_len) {
1820 session->userauth_kybd_auth_instruction =
1821 LIBSSH2_ALLOC(session,
1822 session->userauth_kybd_auth_instruction_len);
1823 if(!session->userauth_kybd_auth_instruction) {
1824 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1825 "Unable to allocate memory for "
1826 "keyboard-interactive 'instruction' "
1827 "request field");
1828 goto cleanup;
1829 }
1830 if(s + session->userauth_kybd_auth_instruction_len <=
1831 session->userauth_kybd_data +
1832 session->userauth_kybd_data_len) {
1833 memcpy(session->userauth_kybd_auth_instruction, s,
1834 session->userauth_kybd_auth_instruction_len);
1835 s += session->userauth_kybd_auth_instruction_len;
1836 }
1837 else {
1838 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1839 "userauth keyboard data buffer too small"
1840 "for auth instruction");
1841 goto cleanup;
1842 }
1843 }
1844
1845 if(s + 4 <= session->userauth_kybd_data +
1846 session->userauth_kybd_data_len) {
1847 /* string language tag (as defined in [RFC-3066]) */
1848 language_tag_len = _libssh2_ntohu32(s);
1849 s += 4;
1850 }
1851 else {
1852 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1853 "userauth keyboard data buffer too small"
1854 "for auth language tag length");
1855 goto cleanup;
1856 }
1857
1858 if(s + language_tag_len <= session->userauth_kybd_data +
1859 session->userauth_kybd_data_len) {
1860 /* ignoring this field as deprecated */
1861 s += language_tag_len;
1862 }
1863 else {
1864 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1865 "userauth keyboard data buffer too small"
1866 "for auth language tag");
1867 goto cleanup;
1868 }
1869
1870 if(s + 4 <= session->userauth_kybd_data +
1871 session->userauth_kybd_data_len) {
1872 /* int num-prompts */
1873 session->userauth_kybd_num_prompts = _libssh2_ntohu32(s);
1874 s += 4;
1875 }
1876 else {
1877 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1878 "userauth keyboard data buffer too small"
1879 "for auth num keyboard prompts");
1880 goto cleanup;
1881 }
1882
1883 if(session->userauth_kybd_num_prompts > 100) {
1884 _libssh2_error(session, LIBSSH2_ERROR_OUT_OF_BOUNDARY,
1885 "Too many replies for "
1886 "keyboard-interactive prompts");
1887 goto cleanup;
1888 }
1889
1890 if(session->userauth_kybd_num_prompts) {
1891 session->userauth_kybd_prompts =
1892 LIBSSH2_CALLOC(session,
1893 sizeof(LIBSSH2_USERAUTH_KBDINT_PROMPT) *
1894 session->userauth_kybd_num_prompts);
1895 if(!session->userauth_kybd_prompts) {
1896 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1897 "Unable to allocate memory for "
1898 "keyboard-interactive prompts array");
1899 goto cleanup;
1900 }
1901
1902 session->userauth_kybd_responses =
1903 LIBSSH2_CALLOC(session,
1904 sizeof(LIBSSH2_USERAUTH_KBDINT_RESPONSE) *
1905 session->userauth_kybd_num_prompts);
1906 if(!session->userauth_kybd_responses) {
1907 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1908 "Unable to allocate memory for "
1909 "keyboard-interactive responses array");
1910 goto cleanup;
1911 }
1912
1913 for(i = 0; i < session->userauth_kybd_num_prompts; i++) {
1914 if(s + 4 <= session->userauth_kybd_data +
1915 session->userauth_kybd_data_len) {
1916 /* string prompt[1] (ISO-10646 UTF-8) */
1917 session->userauth_kybd_prompts[i].length =
1918 _libssh2_ntohu32(s);
1919 s += 4;
1920 }
1921 else {
1922 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1923 "userauth keyboard data buffer too "
1924 "small for auth keyboard "
1925 "prompt length");
1926 goto cleanup;
1927 }
1928
1929 session->userauth_kybd_prompts[i].text =
1930 LIBSSH2_CALLOC(session,
1931 session->userauth_kybd_prompts[i].
1932 length);
1933 if(!session->userauth_kybd_prompts[i].text) {
1934 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1935 "Unable to allocate memory for "
1936 "keyboard-interactive prompt message");
1937 goto cleanup;
1938 }
1939
1940 if(s + session->userauth_kybd_prompts[i].length <=
1941 session->userauth_kybd_data +
1942 session->userauth_kybd_data_len) {
1943 memcpy(session->userauth_kybd_prompts[i].text, s,
1944 session->userauth_kybd_prompts[i].length);
1945 s += session->userauth_kybd_prompts[i].length;
1946 }
1947 else {
1948 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1949 "userauth keyboard data buffer too "
1950 "small for auth keyboard prompt");
1951 goto cleanup;
1952 }
1953 if(s < session->userauth_kybd_data +
1954 session->userauth_kybd_data_len) {
1955 /* boolean echo[1] */
1956 session->userauth_kybd_prompts[i].echo = *s++;
1957 }
1958 else {
1959 _libssh2_error(session, LIBSSH2_ERROR_BUFFER_TOO_SMALL,
1960 "userauth keyboard data buffer too "
1961 "small for auth keyboard prompt echo");
1962 goto cleanup;
1963 }
1964 }
1965 }
1966
1967 response_callback(session->userauth_kybd_auth_name,
1968 session->userauth_kybd_auth_name_len,
1969 session->userauth_kybd_auth_instruction,
1970 session->userauth_kybd_auth_instruction_len,
1971 session->userauth_kybd_num_prompts,
1972 session->userauth_kybd_prompts,
1973 session->userauth_kybd_responses,
1974 &session->abstract);
1975
1976 _libssh2_debug(session, LIBSSH2_TRACE_AUTH,
1977 "Keyboard-interactive response callback function"
1978 " invoked");
1979
1980 session->userauth_kybd_packet_len =
1981 1 /* byte SSH_MSG_USERAUTH_INFO_RESPONSE */
1982 + 4 /* int num-responses */
1983 ;
1984
1985 for(i = 0; i < session->userauth_kybd_num_prompts; i++) {
1986 /* string response[1] (ISO-10646 UTF-8) */
1987 if(session->userauth_kybd_responses[i].length <=
1988 (SIZE_MAX - 4 - session->userauth_kybd_packet_len) ) {
1989 session->userauth_kybd_packet_len +=
1990 4 + session->userauth_kybd_responses[i].length;
1991 }
1992 else {
1993 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
1994 "Unable to allocate memory for keyboard-"
1995 "interactive response packet");
1996 goto cleanup;
1997 }
1998 }
1999
2000 /* A new userauth_kybd_data area is to be allocated, free the
2001 former one. */
2002 LIBSSH2_FREE(session, session->userauth_kybd_data);
2003
2004 session->userauth_kybd_data = s =
2005 LIBSSH2_ALLOC(session, session->userauth_kybd_packet_len);
2006 if(!s) {
2007 _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
2008 "Unable to allocate memory for keyboard-"
2009 "interactive response packet");
2010 goto cleanup;
2011 }
2012
2013 *s = SSH_MSG_USERAUTH_INFO_RESPONSE;
2014 s++;
2015 _libssh2_store_u32(&s, session->userauth_kybd_num_prompts);
2016
2017 for(i = 0; i < session->userauth_kybd_num_prompts; i++) {
2018 _libssh2_store_str(&s,
2019 session->userauth_kybd_responses[i].text,
2020 session->userauth_kybd_responses[i].length);
2021 }
2022
2023 session->userauth_kybd_state = libssh2_NB_state_sent1;
2024 }
2025
2026 if(session->userauth_kybd_state == libssh2_NB_state_sent1) {
2027 rc = _libssh2_transport_send(session, session->userauth_kybd_data,
2028 session->userauth_kybd_packet_len,
2029 NULL, 0);
2030 if(rc == LIBSSH2_ERROR_EAGAIN)
2031 return _libssh2_error(session, LIBSSH2_ERROR_EAGAIN,
2032 "Would block");
2033 if(rc) {
2034 _libssh2_error(session, LIBSSH2_ERROR_SOCKET_SEND,
2035 "Unable to send userauth-keyboard-interactive"
2036 " request");
2037 goto cleanup;
2038 }
2039
2040 session->userauth_kybd_auth_failure = 0;
2041 }
2042
2043 cleanup:
2044 /*
2045 * It's safe to clean all the data here, because unallocated pointers
2046 * are filled by zeroes
2047 */
2048
2049 LIBSSH2_FREE(session, session->userauth_kybd_data);
2050 session->userauth_kybd_data = NULL;
2051
2052 if(session->userauth_kybd_prompts) {
2053 for(i = 0; i < session->userauth_kybd_num_prompts; i++) {
2054 LIBSSH2_FREE(session, session->userauth_kybd_prompts[i].text);
2055 session->userauth_kybd_prompts[i].text = NULL;
2056 }
2057 }
2058
2059 if(session->userauth_kybd_responses) {
2060 for(i = 0; i < session->userauth_kybd_num_prompts; i++) {
2061 LIBSSH2_FREE(session,
2062 session->userauth_kybd_responses[i].text);
2063 session->userauth_kybd_responses[i].text = NULL;
2064 }
2065 }
2066
2067 if(session->userauth_kybd_prompts) {
2068 LIBSSH2_FREE(session, session->userauth_kybd_prompts);
2069 session->userauth_kybd_prompts = NULL;
2070 }
2071 if(session->userauth_kybd_responses) {
2072 LIBSSH2_FREE(session, session->userauth_kybd_responses);
2073 session->userauth_kybd_responses = NULL;
2074 }
2075 if(session->userauth_kybd_auth_name) {
2076 LIBSSH2_FREE(session, session->userauth_kybd_auth_name);
2077 session->userauth_kybd_auth_name = NULL;
2078 }
2079 if(session->userauth_kybd_auth_instruction) {
2080 LIBSSH2_FREE(session, session->userauth_kybd_auth_instruction);
2081 session->userauth_kybd_auth_instruction = NULL;
2082 }
2083
2084 if(session->userauth_kybd_auth_failure) {
2085 session->userauth_kybd_state = libssh2_NB_state_idle;
2086 return -1;
2087 }
2088
2089 session->userauth_kybd_state = libssh2_NB_state_sent;
2090 }
2091 }
2092
2093 /*
2094 * libssh2_userauth_keyboard_interactive_ex
2095 *
2096 * Authenticate using a challenge-response authentication
2097 */
2098 LIBSSH2_API int
libssh2_userauth_keyboard_interactive_ex(LIBSSH2_SESSION * session,const char * user,unsigned int user_len,LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC ((* response_callback)))2099 libssh2_userauth_keyboard_interactive_ex(LIBSSH2_SESSION *session,
2100 const char *user,
2101 unsigned int user_len,
2102 LIBSSH2_USERAUTH_KBDINT_RESPONSE_FUNC
2103 ((*response_callback)))
2104 {
2105 int rc;
2106 BLOCK_ADJUST(rc, session,
2107 userauth_keyboard_interactive(session, user, user_len,
2108 response_callback));
2109 return rc;
2110 }
2111