Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.62
1.62 ! markus 1: /* $OpenBSD: ssh-agent.c,v 1.61 2001/07/04 22:47:19 markus Exp $ */
1.15 markus 2:
1.1 deraadt 3: /*
1.22 deraadt 4: * Author: Tatu Ylonen <ylo@cs.hut.fi>
5: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6: * All rights reserved
7: * The authentication agent program.
1.33 markus 8: *
1.35 deraadt 9: * As far as I am concerned, the code I have written for this software
10: * can be used freely for any purpose. Any derived versions of this
11: * software must be clearly marked as such, and if the derived work is
12: * incompatible with the protocol description in the RFC file, it must be
13: * called by a name other than "ssh" or "Secure Shell".
14: *
1.56 markus 15: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 16: *
17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 36: */
1.1 deraadt 37:
38: #include "includes.h"
1.62 ! markus 39: RCSID("$OpenBSD: ssh-agent.c,v 1.61 2001/07/04 22:47:19 markus Exp $");
1.47 markus 40:
41: #include <openssl/evp.h>
42: #include <openssl/md5.h>
1.1 deraadt 43:
44: #include "ssh.h"
45: #include "rsa.h"
46: #include "buffer.h"
47: #include "bufaux.h"
48: #include "xmalloc.h"
49: #include "packet.h"
50: #include "getput.h"
51: #include "mpaux.h"
1.32 markus 52: #include "key.h"
53: #include "authfd.h"
1.47 markus 54: #include "cipher.h"
1.33 markus 55: #include "kex.h"
1.37 markus 56: #include "compat.h"
1.47 markus 57: #include "log.h"
1.7 deraadt 58:
1.59 markus 59: #ifdef SMARTCARD
60: #include <openssl/engine.h>
61: #include "scard.h"
62: #endif
63:
1.21 markus 64: typedef struct {
65: int fd;
66: enum {
67: AUTH_UNUSED, AUTH_SOCKET, AUTH_CONNECTION
68: } type;
69: Buffer input;
70: Buffer output;
1.1 deraadt 71: } SocketEntry;
72:
1.45 markus 73: u_int sockets_alloc = 0;
1.1 deraadt 74: SocketEntry *sockets = NULL;
75:
1.21 markus 76: typedef struct {
1.33 markus 77: Key *key;
1.21 markus 78: char *comment;
1.1 deraadt 79: } Identity;
80:
1.33 markus 81: typedef struct {
82: int nentries;
83: Identity *identities;
84: } Idtab;
85:
86: /* private key table, one per protocol version */
87: Idtab idtable[3];
1.1 deraadt 88:
89: int max_fd = 0;
90:
1.11 markus 91: /* pid of shell == parent of agent */
1.29 deraadt 92: pid_t parent_pid = -1;
1.10 markus 93:
94: /* pathname and directory for AUTH_SOCKET */
95: char socket_name[1024];
96: char socket_dir[1024];
97:
1.20 markus 98: extern char *__progname;
99:
1.55 itojun 100: static void
1.33 markus 101: idtab_init(void)
1.1 deraadt 102: {
1.33 markus 103: int i;
104: for (i = 0; i <=2; i++){
105: idtable[i].identities = NULL;
106: idtable[i].nentries = 0;
107: }
108: }
109:
110: /* return private key table for requested protocol version */
1.55 itojun 111: static Idtab *
1.33 markus 112: idtab_lookup(int version)
113: {
114: if (version < 1 || version > 2)
115: fatal("internal error, bad protocol version %d", version);
116: return &idtable[version];
117: }
118:
119: /* return matching private key for given public key */
1.55 itojun 120: static Key *
1.33 markus 121: lookup_private_key(Key *key, int *idx, int version)
122: {
123: int i;
124: Idtab *tab = idtab_lookup(version);
125: for (i = 0; i < tab->nentries; i++) {
126: if (key_equal(key, tab->identities[i].key)) {
127: if (idx != NULL)
128: *idx = i;
129: return tab->identities[i].key;
130: }
131: }
132: return NULL;
133: }
134:
135: /* send list of supported public keys to 'client' */
1.55 itojun 136: static void
1.33 markus 137: process_request_identities(SocketEntry *e, int version)
138: {
139: Idtab *tab = idtab_lookup(version);
1.21 markus 140: Buffer msg;
141: int i;
1.1 deraadt 142:
1.21 markus 143: buffer_init(&msg);
1.33 markus 144: buffer_put_char(&msg, (version == 1) ?
145: SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
146: buffer_put_int(&msg, tab->nentries);
147: for (i = 0; i < tab->nentries; i++) {
148: Identity *id = &tab->identities[i];
1.39 markus 149: if (id->key->type == KEY_RSA1) {
1.33 markus 150: buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
151: buffer_put_bignum(&msg, id->key->rsa->e);
152: buffer_put_bignum(&msg, id->key->rsa->n);
153: } else {
1.45 markus 154: u_char *blob;
155: u_int blen;
1.39 markus 156: key_to_blob(id->key, &blob, &blen);
1.33 markus 157: buffer_put_string(&msg, blob, blen);
158: xfree(blob);
159: }
160: buffer_put_cstring(&msg, id->comment);
1.21 markus 161: }
162: buffer_put_int(&e->output, buffer_len(&msg));
163: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
164: buffer_free(&msg);
1.1 deraadt 165: }
166:
1.33 markus 167: /* ssh1 only */
1.55 itojun 168: static void
1.33 markus 169: process_authentication_challenge1(SocketEntry *e)
1.1 deraadt 170: {
1.33 markus 171: Key *key, *private;
172: BIGNUM *challenge;
173: int i, len;
1.21 markus 174: Buffer msg;
175: MD5_CTX md;
1.45 markus 176: u_char buf[32], mdbuf[16], session_id[16];
177: u_int response_type;
1.21 markus 178:
179: buffer_init(&msg);
1.39 markus 180: key = key_new(KEY_RSA1);
1.21 markus 181: challenge = BN_new();
1.33 markus 182:
183: buffer_get_int(&e->input); /* ignored */
184: buffer_get_bignum(&e->input, key->rsa->e);
185: buffer_get_bignum(&e->input, key->rsa->n);
1.21 markus 186: buffer_get_bignum(&e->input, challenge);
187:
1.33 markus 188: /* Only protocol 1.1 is supported */
189: if (buffer_len(&e->input) == 0)
190: goto failure;
191: buffer_get(&e->input, (char *) session_id, 16);
192: response_type = buffer_get_int(&e->input);
193: if (response_type != 1)
194: goto failure;
195:
196: private = lookup_private_key(key, NULL, 1);
197: if (private != NULL) {
198: /* Decrypt the challenge using the private key. */
1.49 markus 199: if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
200: goto failure;
1.33 markus 201:
202: /* The response is MD5 of decrypted challenge plus session id. */
203: len = BN_num_bytes(challenge);
204: if (len <= 0 || len > 32) {
205: log("process_authentication_challenge: bad challenge length %d", len);
206: goto failure;
207: }
208: memset(buf, 0, 32);
209: BN_bn2bin(challenge, buf + 32 - len);
210: MD5_Init(&md);
211: MD5_Update(&md, buf, 32);
212: MD5_Update(&md, session_id, 16);
213: MD5_Final(mdbuf, &md);
214:
215: /* Send the response. */
216: buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
217: for (i = 0; i < 16; i++)
218: buffer_put_char(&msg, mdbuf[i]);
219: goto send;
220: }
1.21 markus 221:
1.33 markus 222: failure:
223: /* Unknown identity or protocol error. Send failure. */
1.21 markus 224: buffer_put_char(&msg, SSH_AGENT_FAILURE);
225: send:
226: buffer_put_int(&e->output, buffer_len(&msg));
1.33 markus 227: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
228: key_free(key);
229: BN_clear_free(challenge);
230: buffer_free(&msg);
231: }
232:
233: /* ssh2 only */
1.55 itojun 234: static void
1.33 markus 235: process_sign_request2(SocketEntry *e)
236: {
237: extern int datafellows;
238: Key *key, *private;
1.45 markus 239: u_char *blob, *data, *signature = NULL;
240: u_int blen, dlen, slen = 0;
1.37 markus 241: int flags;
1.33 markus 242: Buffer msg;
243: int ok = -1;
244:
245: datafellows = 0;
1.43 markus 246:
1.33 markus 247: blob = buffer_get_string(&e->input, &blen);
248: data = buffer_get_string(&e->input, &dlen);
1.37 markus 249:
250: flags = buffer_get_int(&e->input);
251: if (flags & SSH_AGENT_OLD_SIGNATURE)
252: datafellows = SSH_BUG_SIGBLOB;
1.33 markus 253:
1.39 markus 254: key = key_from_blob(blob, blen);
1.33 markus 255: if (key != NULL) {
256: private = lookup_private_key(key, NULL, 2);
257: if (private != NULL)
1.39 markus 258: ok = key_sign(private, &signature, &slen, data, dlen);
1.33 markus 259: }
260: key_free(key);
261: buffer_init(&msg);
262: if (ok == 0) {
263: buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
264: buffer_put_string(&msg, signature, slen);
265: } else {
266: buffer_put_char(&msg, SSH_AGENT_FAILURE);
267: }
268: buffer_put_int(&e->output, buffer_len(&msg));
1.21 markus 269: buffer_append(&e->output, buffer_ptr(&msg),
1.33 markus 270: buffer_len(&msg));
1.21 markus 271: buffer_free(&msg);
1.33 markus 272: xfree(data);
273: xfree(blob);
274: if (signature != NULL)
275: xfree(signature);
1.1 deraadt 276: }
277:
1.33 markus 278: /* shared */
1.55 itojun 279: static void
1.33 markus 280: process_remove_identity(SocketEntry *e, int version)
1.1 deraadt 281: {
1.33 markus 282: Key *key = NULL, *private;
1.45 markus 283: u_char *blob;
284: u_int blen;
285: u_int bits;
1.33 markus 286: int success = 0;
1.21 markus 287:
1.33 markus 288: switch(version){
289: case 1:
1.39 markus 290: key = key_new(KEY_RSA1);
1.33 markus 291: bits = buffer_get_int(&e->input);
292: buffer_get_bignum(&e->input, key->rsa->e);
293: buffer_get_bignum(&e->input, key->rsa->n);
294:
295: if (bits != key_size(key))
296: log("Warning: identity keysize mismatch: actual %d, announced %d",
1.46 markus 297: key_size(key), bits);
1.33 markus 298: break;
299: case 2:
300: blob = buffer_get_string(&e->input, &blen);
1.39 markus 301: key = key_from_blob(blob, blen);
1.33 markus 302: xfree(blob);
303: break;
304: }
305: if (key != NULL) {
306: int idx;
307: private = lookup_private_key(key, &idx, version);
308: if (private != NULL) {
1.23 markus 309: /*
310: * We have this key. Free the old key. Since we
311: * don\'t want to leave empty slots in the middle of
1.40 markus 312: * the array, we actually free the key there and move
313: * all the entries between the empty slot and the end
314: * of the array.
1.23 markus 315: */
1.33 markus 316: Idtab *tab = idtab_lookup(version);
317: key_free(tab->identities[idx].key);
318: xfree(tab->identities[idx].comment);
1.38 markus 319: if (tab->nentries < 1)
320: fatal("process_remove_identity: "
321: "internal error: tab->nentries %d",
322: tab->nentries);
1.40 markus 323: if (idx != tab->nentries - 1) {
324: int i;
325: for (i = idx; i < tab->nentries - 1; i++)
326: tab->identities[i] = tab->identities[i+1];
327: }
328: tab->identities[tab->nentries - 1].key = NULL;
329: tab->identities[tab->nentries - 1].comment = NULL;
1.33 markus 330: tab->nentries--;
331: success = 1;
1.21 markus 332: }
1.33 markus 333: key_free(key);
334: }
1.1 deraadt 335: buffer_put_int(&e->output, 1);
1.33 markus 336: buffer_put_char(&e->output,
337: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 338: }
339:
1.55 itojun 340: static void
1.33 markus 341: process_remove_all_identities(SocketEntry *e, int version)
1.1 deraadt 342: {
1.45 markus 343: u_int i;
1.33 markus 344: Idtab *tab = idtab_lookup(version);
1.21 markus 345:
346: /* Loop over all identities and clear the keys. */
1.33 markus 347: for (i = 0; i < tab->nentries; i++) {
348: key_free(tab->identities[i].key);
349: xfree(tab->identities[i].comment);
1.21 markus 350: }
351:
352: /* Mark that there are no identities. */
1.33 markus 353: tab->nentries = 0;
1.21 markus 354:
355: /* Send success. */
356: buffer_put_int(&e->output, 1);
357: buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
358: return;
1.1 deraadt 359: }
360:
1.55 itojun 361: static void
1.33 markus 362: process_add_identity(SocketEntry *e, int version)
1.1 deraadt 363: {
1.33 markus 364: Key *k = NULL;
1.39 markus 365: char *type_name;
1.33 markus 366: char *comment;
1.39 markus 367: int type, success = 0;
1.33 markus 368: Idtab *tab = idtab_lookup(version);
369:
370: switch (version) {
371: case 1:
1.39 markus 372: k = key_new_private(KEY_RSA1);
1.46 markus 373: buffer_get_int(&e->input); /* ignored */
1.39 markus 374: buffer_get_bignum(&e->input, k->rsa->n);
375: buffer_get_bignum(&e->input, k->rsa->e);
376: buffer_get_bignum(&e->input, k->rsa->d);
377: buffer_get_bignum(&e->input, k->rsa->iqmp);
1.33 markus 378:
379: /* SSH and SSL have p and q swapped */
1.39 markus 380: buffer_get_bignum(&e->input, k->rsa->q); /* p */
381: buffer_get_bignum(&e->input, k->rsa->p); /* q */
1.33 markus 382:
383: /* Generate additional parameters */
1.60 markus 384: rsa_generate_additional_parameters(k->rsa);
1.33 markus 385: break;
386: case 2:
1.39 markus 387: type_name = buffer_get_string(&e->input, NULL);
1.46 markus 388: type = key_type_from_name(type_name);
1.39 markus 389: xfree(type_name);
390: switch(type) {
391: case KEY_DSA:
392: k = key_new_private(type);
393: buffer_get_bignum2(&e->input, k->dsa->p);
394: buffer_get_bignum2(&e->input, k->dsa->q);
395: buffer_get_bignum2(&e->input, k->dsa->g);
396: buffer_get_bignum2(&e->input, k->dsa->pub_key);
397: buffer_get_bignum2(&e->input, k->dsa->priv_key);
398: break;
399: case KEY_RSA:
400: k = key_new_private(type);
401: buffer_get_bignum2(&e->input, k->rsa->n);
402: buffer_get_bignum2(&e->input, k->rsa->e);
403: buffer_get_bignum2(&e->input, k->rsa->d);
404: buffer_get_bignum2(&e->input, k->rsa->iqmp);
405: buffer_get_bignum2(&e->input, k->rsa->p);
406: buffer_get_bignum2(&e->input, k->rsa->q);
407:
408: /* Generate additional parameters */
1.60 markus 409: rsa_generate_additional_parameters(k->rsa);
1.39 markus 410: break;
411: default:
1.33 markus 412: buffer_clear(&e->input);
413: goto send;
1.21 markus 414: }
1.33 markus 415: break;
416: }
417: comment = buffer_get_string(&e->input, NULL);
418: if (k == NULL) {
419: xfree(comment);
420: goto send;
421: }
422: success = 1;
423: if (lookup_private_key(k, NULL, version) == NULL) {
424: if (tab->nentries == 0)
425: tab->identities = xmalloc(sizeof(Identity));
426: else
427: tab->identities = xrealloc(tab->identities,
428: (tab->nentries + 1) * sizeof(Identity));
429: tab->identities[tab->nentries].key = k;
430: tab->identities[tab->nentries].comment = comment;
431: /* Increment the number of identities. */
432: tab->nentries++;
433: } else {
434: key_free(k);
435: xfree(comment);
436: }
437: send:
1.1 deraadt 438: buffer_put_int(&e->output, 1);
1.33 markus 439: buffer_put_char(&e->output,
440: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 441: }
442:
1.59 markus 443:
444: #ifdef SMARTCARD
445: static void
446: process_add_smartcard_key (SocketEntry *e)
447: {
448: Idtab *tab;
449: Key *n = NULL, *k = NULL;
450: int success = 0;
451: int sc_reader_num = 0;
452:
453: sc_reader_num = buffer_get_int(&e->input);
454:
455: k = sc_get_key(sc_reader_num);
456: if (k == NULL) {
457: error("sc_get_pubkey failed");
458: goto send;
459: }
460: success = 1;
461:
462: tab = idtab_lookup(1);
463: if (lookup_private_key(k, NULL, 1) == NULL) {
464: if (tab->nentries == 0)
465: tab->identities = xmalloc(sizeof(Identity));
466: else
467: tab->identities = xrealloc(tab->identities,
468: (tab->nentries + 1) * sizeof(Identity));
469: n = key_new(KEY_RSA1);
470: BN_copy(n->rsa->n, k->rsa->n);
471: BN_copy(n->rsa->e, k->rsa->e);
472: RSA_set_method(n->rsa, sc_get_engine());
473: tab->identities[tab->nentries].key = n;
474: tab->identities[tab->nentries].comment =
475: xstrdup("rsa1 smartcard");
476: tab->nentries++;
477: }
478: tab = idtab_lookup(2);
479: if (lookup_private_key(k, NULL, 2) == NULL) {
480: if (tab->nentries == 0)
481: tab->identities = xmalloc(sizeof(Identity));
482: else
483: tab->identities = xrealloc(tab->identities,
484: (tab->nentries + 1) * sizeof(Identity));
485: n = key_new(KEY_RSA);
486: BN_copy(n->rsa->n, k->rsa->n);
487: BN_copy(n->rsa->e, k->rsa->e);
488: RSA_set_method(n->rsa, sc_get_engine());
489: tab->identities[tab->nentries].key = n;
490: tab->identities[tab->nentries].comment =
491: xstrdup("rsa smartcard");
492: tab->nentries++;
493: }
494: key_free(k);
495: send:
496: buffer_put_int(&e->output, 1);
497: buffer_put_char(&e->output,
498: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
499: }
500:
501: static void
502: process_remove_smartcard_key(SocketEntry *e)
503: {
504: Key *k = NULL, *private;
505: int idx;
506: int success = 0;
507: int sc_reader_num = 0;
508:
509: sc_reader_num = buffer_get_int(&e->input);
510:
511: if ((k = sc_get_key(sc_reader_num)) == NULL) {
512: error("sc_get_pubkey failed");
513: } else {
514: private = lookup_private_key(k, &idx, 1);
515: if (private != NULL) {
516: Idtab *tab = idtab_lookup(1);
517: key_free(tab->identities[idx].key);
518: xfree(tab->identities[idx].comment);
519: if (idx != tab->nentries)
520: tab->identities[idx] = tab->identities[tab->nentries];
521: tab->nentries--;
522: success = 1;
523: }
524: private = lookup_private_key(k, &idx, 2);
525: if (private != NULL) {
526: Idtab *tab = idtab_lookup(2);
527: key_free(tab->identities[idx].key);
528: xfree(tab->identities[idx].comment);
529: if (idx != tab->nentries)
530: tab->identities[idx] = tab->identities[tab->nentries];
531: tab->nentries--;
532: success = 1;
533: }
534: key_free(k);
1.62 ! markus 535: sc_close();
1.59 markus 536: }
537:
538: buffer_put_int(&e->output, 1);
539: buffer_put_char(&e->output,
540: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
541: }
542: #endif
543:
1.33 markus 544: /* dispatch incoming messages */
545:
1.55 itojun 546: static void
1.2 provos 547: process_message(SocketEntry *e)
1.1 deraadt 548: {
1.45 markus 549: u_int msg_len;
550: u_int type;
551: u_char *cp;
1.21 markus 552: if (buffer_len(&e->input) < 5)
553: return; /* Incomplete message. */
1.45 markus 554: cp = (u_char *) buffer_ptr(&e->input);
1.21 markus 555: msg_len = GET_32BIT(cp);
556: if (msg_len > 256 * 1024) {
557: shutdown(e->fd, SHUT_RDWR);
558: close(e->fd);
559: e->type = AUTH_UNUSED;
560: return;
561: }
562: if (buffer_len(&e->input) < msg_len + 4)
563: return;
564: buffer_consume(&e->input, 4);
565: type = buffer_get_char(&e->input);
566:
1.59 markus 567: debug("type %d", type);
1.21 markus 568: switch (type) {
1.33 markus 569: /* ssh1 */
570: case SSH_AGENTC_RSA_CHALLENGE:
571: process_authentication_challenge1(e);
572: break;
1.21 markus 573: case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
1.33 markus 574: process_request_identities(e, 1);
1.21 markus 575: break;
576: case SSH_AGENTC_ADD_RSA_IDENTITY:
1.33 markus 577: process_add_identity(e, 1);
1.21 markus 578: break;
579: case SSH_AGENTC_REMOVE_RSA_IDENTITY:
1.33 markus 580: process_remove_identity(e, 1);
1.21 markus 581: break;
582: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.33 markus 583: process_remove_all_identities(e, 1);
584: break;
585: /* ssh2 */
586: case SSH2_AGENTC_SIGN_REQUEST:
587: process_sign_request2(e);
588: break;
589: case SSH2_AGENTC_REQUEST_IDENTITIES:
590: process_request_identities(e, 2);
591: break;
592: case SSH2_AGENTC_ADD_IDENTITY:
593: process_add_identity(e, 2);
594: break;
595: case SSH2_AGENTC_REMOVE_IDENTITY:
596: process_remove_identity(e, 2);
597: break;
598: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
599: process_remove_all_identities(e, 2);
1.21 markus 600: break;
1.59 markus 601: #ifdef SMARTCARD
602: case SSH_AGENTC_ADD_SMARTCARD_KEY:
603: process_add_smartcard_key(e);
604: break;
605: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
606: process_remove_smartcard_key(e);
607: break;
608: #endif
1.21 markus 609: default:
610: /* Unknown message. Respond with failure. */
611: error("Unknown message %d", type);
612: buffer_clear(&e->input);
613: buffer_put_int(&e->output, 1);
614: buffer_put_char(&e->output, SSH_AGENT_FAILURE);
615: break;
616: }
1.1 deraadt 617: }
618:
1.55 itojun 619: static void
1.2 provos 620: new_socket(int type, int fd)
1.1 deraadt 621: {
1.45 markus 622: u_int i, old_alloc;
1.21 markus 623: if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
624: error("fcntl O_NONBLOCK: %s", strerror(errno));
625:
626: if (fd > max_fd)
627: max_fd = fd;
628:
629: for (i = 0; i < sockets_alloc; i++)
630: if (sockets[i].type == AUTH_UNUSED) {
631: sockets[i].fd = fd;
632: sockets[i].type = type;
633: buffer_init(&sockets[i].input);
634: buffer_init(&sockets[i].output);
635: return;
636: }
637: old_alloc = sockets_alloc;
638: sockets_alloc += 10;
639: if (sockets)
640: sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0]));
641: else
642: sockets = xmalloc(sockets_alloc * sizeof(sockets[0]));
643: for (i = old_alloc; i < sockets_alloc; i++)
644: sockets[i].type = AUTH_UNUSED;
645: sockets[old_alloc].type = type;
646: sockets[old_alloc].fd = fd;
647: buffer_init(&sockets[old_alloc].input);
648: buffer_init(&sockets[old_alloc].output);
1.1 deraadt 649: }
650:
1.55 itojun 651: static int
1.46 markus 652: prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl)
1.1 deraadt 653: {
1.46 markus 654: u_int i, sz;
655: int n = 0;
656:
657: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 658: switch (sockets[i].type) {
659: case AUTH_SOCKET:
660: case AUTH_CONNECTION:
1.46 markus 661: n = MAX(n, sockets[i].fd);
1.21 markus 662: break;
663: case AUTH_UNUSED:
664: break;
665: default:
666: fatal("Unknown socket type %d", sockets[i].type);
667: break;
668: }
1.46 markus 669: }
670:
671: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
672: if (*fdrp == NULL || n > *fdl) {
673: if (*fdrp)
1.54 stevesk 674: xfree(*fdrp);
1.46 markus 675: if (*fdwp)
1.54 stevesk 676: xfree(*fdwp);
1.46 markus 677: *fdrp = xmalloc(sz);
678: *fdwp = xmalloc(sz);
679: *fdl = n;
680: }
681: memset(*fdrp, 0, sz);
682: memset(*fdwp, 0, sz);
683:
684: for (i = 0; i < sockets_alloc; i++) {
685: switch (sockets[i].type) {
686: case AUTH_SOCKET:
687: case AUTH_CONNECTION:
688: FD_SET(sockets[i].fd, *fdrp);
689: if (buffer_len(&sockets[i].output) > 0)
690: FD_SET(sockets[i].fd, *fdwp);
691: break;
692: default:
693: break;
694: }
695: }
696: return (1);
1.21 markus 697: }
698:
1.55 itojun 699: static void
1.21 markus 700: after_select(fd_set *readset, fd_set *writeset)
701: {
1.45 markus 702: u_int i;
1.21 markus 703: int len, sock;
1.26 markus 704: socklen_t slen;
1.21 markus 705: char buf[1024];
706: struct sockaddr_un sunaddr;
707:
708: for (i = 0; i < sockets_alloc; i++)
709: switch (sockets[i].type) {
710: case AUTH_UNUSED:
711: break;
712: case AUTH_SOCKET:
713: if (FD_ISSET(sockets[i].fd, readset)) {
1.26 markus 714: slen = sizeof(sunaddr);
1.46 markus 715: sock = accept(sockets[i].fd,
716: (struct sockaddr *) &sunaddr, &slen);
1.21 markus 717: if (sock < 0) {
718: perror("accept from AUTH_SOCKET");
719: break;
720: }
721: new_socket(AUTH_CONNECTION, sock);
722: }
723: break;
724: case AUTH_CONNECTION:
725: if (buffer_len(&sockets[i].output) > 0 &&
726: FD_ISSET(sockets[i].fd, writeset)) {
1.52 deraadt 727: do {
728: len = write(sockets[i].fd,
729: buffer_ptr(&sockets[i].output),
730: buffer_len(&sockets[i].output));
731: if (len == -1 && (errno == EAGAIN ||
732: errno == EINTR))
733: continue;
734: break;
735: } while (1);
1.21 markus 736: if (len <= 0) {
737: shutdown(sockets[i].fd, SHUT_RDWR);
738: close(sockets[i].fd);
739: sockets[i].type = AUTH_UNUSED;
1.30 djm 740: buffer_free(&sockets[i].input);
741: buffer_free(&sockets[i].output);
1.21 markus 742: break;
743: }
744: buffer_consume(&sockets[i].output, len);
745: }
746: if (FD_ISSET(sockets[i].fd, readset)) {
1.52 deraadt 747: do {
748: len = read(sockets[i].fd, buf, sizeof(buf));
749: if (len == -1 && (errno == EAGAIN ||
750: errno == EINTR))
751: continue;
752: break;
753: } while (1);
1.21 markus 754: if (len <= 0) {
755: shutdown(sockets[i].fd, SHUT_RDWR);
756: close(sockets[i].fd);
757: sockets[i].type = AUTH_UNUSED;
1.30 djm 758: buffer_free(&sockets[i].input);
759: buffer_free(&sockets[i].output);
1.21 markus 760: break;
761: }
762: buffer_append(&sockets[i].input, buf, len);
763: process_message(&sockets[i]);
764: }
765: break;
766: default:
767: fatal("Unknown type %d", sockets[i].type);
768: }
1.1 deraadt 769: }
770:
1.55 itojun 771: static void
1.2 provos 772: check_parent_exists(int sig)
1.1 deraadt 773: {
1.46 markus 774: int save_errno = errno;
775:
1.29 deraadt 776: if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
1.21 markus 777: /* printf("Parent has died - Authentication agent exiting.\n"); */
778: exit(1);
779: }
780: signal(SIGALRM, check_parent_exists);
781: alarm(10);
1.46 markus 782: errno = save_errno;
1.1 deraadt 783: }
784:
1.55 itojun 785: static void
1.15 markus 786: cleanup_socket(void)
787: {
1.48 deraadt 788: if (socket_name[0])
789: unlink(socket_name);
790: if (socket_dir[0])
791: rmdir(socket_dir);
1.10 markus 792: }
793:
1.55 itojun 794: static void
1.15 markus 795: cleanup_exit(int i)
796: {
1.21 markus 797: cleanup_socket();
798: exit(i);
1.15 markus 799: }
800:
1.55 itojun 801: static void
1.48 deraadt 802: cleanup_handler(int sig)
803: {
804: cleanup_socket();
805: _exit(2);
806: }
807:
1.55 itojun 808: static void
1.50 itojun 809: usage(void)
1.15 markus 810: {
1.21 markus 811: fprintf(stderr, "ssh-agent version %s\n", SSH_VERSION);
1.58 markus 812: fprintf(stderr, "Usage: %s [-c | -s] [-k] [-d] [command {args...]]\n",
1.46 markus 813: __progname);
1.21 markus 814: exit(1);
1.15 markus 815: }
816:
1.2 provos 817: int
818: main(int ac, char **av)
1.1 deraadt 819: {
1.57 markus 820: int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch;
1.21 markus 821: struct sockaddr_un sunaddr;
1.41 markus 822: struct rlimit rlim;
1.21 markus 823: pid_t pid;
824: char *shell, *format, *pidstr, pidstrbuf[1 + 3 * sizeof pid];
1.43 markus 825: extern int optind;
1.46 markus 826: fd_set *readsetp = NULL, *writesetp = NULL;
1.53 markus 827:
828: SSLeay_add_all_algorithms();
1.21 markus 829:
1.57 markus 830: while ((ch = getopt(ac, av, "cdks")) != -1) {
1.21 markus 831: switch (ch) {
832: case 'c':
833: if (s_flag)
834: usage();
835: c_flag++;
836: break;
837: case 'k':
838: k_flag++;
839: break;
840: case 's':
841: if (c_flag)
842: usage();
843: s_flag++;
844: break;
1.57 markus 845: case 'd':
846: if (d_flag)
847: usage();
848: d_flag++;
849: break;
1.21 markus 850: default:
851: usage();
852: }
853: }
854: ac -= optind;
855: av += optind;
856:
1.57 markus 857: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1.21 markus 858: usage();
859:
1.57 markus 860: if (ac == 0 && !c_flag && !k_flag && !s_flag && !d_flag) {
1.21 markus 861: shell = getenv("SHELL");
862: if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
863: c_flag = 1;
864: }
865: if (k_flag) {
866: pidstr = getenv(SSH_AGENTPID_ENV_NAME);
867: if (pidstr == NULL) {
868: fprintf(stderr, "%s not set, cannot kill agent\n",
1.46 markus 869: SSH_AGENTPID_ENV_NAME);
1.21 markus 870: exit(1);
871: }
872: pid = atoi(pidstr);
1.46 markus 873: if (pid < 1) {
1.21 markus 874: fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
1.46 markus 875: SSH_AGENTPID_ENV_NAME, pidstr);
1.21 markus 876: exit(1);
877: }
878: if (kill(pid, SIGTERM) == -1) {
879: perror("kill");
880: exit(1);
881: }
882: format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
883: printf(format, SSH_AUTHSOCKET_ENV_NAME);
884: printf(format, SSH_AGENTPID_ENV_NAME);
885: printf("echo Agent pid %d killed;\n", pid);
886: exit(0);
887: }
888: parent_pid = getpid();
889:
890: /* Create private directory for agent socket */
891: strlcpy(socket_dir, "/tmp/ssh-XXXXXXXX", sizeof socket_dir);
892: if (mkdtemp(socket_dir) == NULL) {
893: perror("mkdtemp: private socket dir");
894: exit(1);
895: }
896: snprintf(socket_name, sizeof socket_name, "%s/agent.%d", socket_dir,
1.46 markus 897: parent_pid);
1.21 markus 898:
1.23 markus 899: /*
900: * Create socket early so it will exist before command gets run from
901: * the parent.
902: */
1.21 markus 903: sock = socket(AF_UNIX, SOCK_STREAM, 0);
904: if (sock < 0) {
905: perror("socket");
906: cleanup_exit(1);
907: }
908: memset(&sunaddr, 0, sizeof(sunaddr));
909: sunaddr.sun_family = AF_UNIX;
910: strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
911: if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
912: perror("bind");
913: cleanup_exit(1);
914: }
915: if (listen(sock, 5) < 0) {
916: perror("listen");
917: cleanup_exit(1);
918: }
1.46 markus 919:
1.23 markus 920: /*
921: * Fork, and have the parent execute the command, if any, or present
922: * the socket data. The child continues as the authentication agent.
923: */
1.57 markus 924: if (d_flag) {
925: log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
926: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
927: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
928: SSH_AUTHSOCKET_ENV_NAME);
929: printf("echo Agent pid %d;\n", parent_pid);
930: goto skip;
931: }
1.21 markus 932: pid = fork();
933: if (pid == -1) {
934: perror("fork");
935: exit(1);
936: }
937: if (pid != 0) { /* Parent - execute the given command. */
938: close(sock);
939: snprintf(pidstrbuf, sizeof pidstrbuf, "%d", pid);
940: if (ac == 0) {
941: format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
942: printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1.46 markus 943: SSH_AUTHSOCKET_ENV_NAME);
1.21 markus 944: printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1.46 markus 945: SSH_AGENTPID_ENV_NAME);
1.21 markus 946: printf("echo Agent pid %d;\n", pid);
947: exit(0);
948: }
1.36 deraadt 949: if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
950: setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
951: perror("setenv");
952: exit(1);
953: }
1.21 markus 954: execvp(av[0], av);
955: perror(av[0]);
956: exit(1);
957: }
958: close(0);
959: close(1);
960: close(2);
961:
1.41 markus 962: /* deny core dumps, since memory contains unencrypted private keys */
963: rlim.rlim_cur = rlim.rlim_max = 0;
964: if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
965: perror("setrlimit rlimit_core failed");
966: cleanup_exit(1);
967: }
1.21 markus 968: if (setsid() == -1) {
969: perror("setsid");
970: cleanup_exit(1);
971: }
1.57 markus 972:
973: skip:
1.21 markus 974: if (atexit(cleanup_socket) < 0) {
975: perror("atexit");
976: cleanup_exit(1);
977: }
978: new_socket(AUTH_SOCKET, sock);
979: if (ac > 0) {
980: signal(SIGALRM, check_parent_exists);
981: alarm(10);
982: }
1.33 markus 983: idtab_init();
1.61 markus 984: if (!d_flag)
1.57 markus 985: signal(SIGINT, SIG_IGN);
1.61 markus 986: signal(SIGPIPE, SIG_IGN);
1.48 deraadt 987: signal(SIGHUP, cleanup_handler);
988: signal(SIGTERM, cleanup_handler);
1.21 markus 989: while (1) {
1.46 markus 990: prepare_select(&readsetp, &writesetp, &max_fd);
991: if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) {
1.21 markus 992: if (errno == EINTR)
993: continue;
994: exit(1);
995: }
1.46 markus 996: after_select(readsetp, writesetp);
1.15 markus 997: }
1.21 markus 998: /* NOTREACHED */
1.1 deraadt 999: }