Annotation of src/usr.bin/ssh/ssh-agent.c, Revision 1.54.2.2
1.1 deraadt 1: /*
1.22 deraadt 2: * Author: Tatu Ylonen <ylo@cs.hut.fi>
3: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4: * All rights reserved
5: * The authentication agent program.
1.33 markus 6: *
1.35 deraadt 7: * As far as I am concerned, the code I have written for this software
8: * can be used freely for any purpose. Any derived versions of this
9: * software must be clearly marked as such, and if the derived work is
10: * incompatible with the protocol description in the RFC file, it must be
11: * called by a name other than "ssh" or "Secure Shell".
12: *
1.54.2.1 jason 13: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.35 deraadt 14: *
15: * Redistribution and use in source and binary forms, with or without
16: * modification, are permitted provided that the following conditions
17: * are met:
18: * 1. Redistributions of source code must retain the above copyright
19: * notice, this list of conditions and the following disclaimer.
20: * 2. Redistributions in binary form must reproduce the above copyright
21: * notice, this list of conditions and the following disclaimer in the
22: * documentation and/or other materials provided with the distribution.
23: *
24: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.22 deraadt 34: */
1.1 deraadt 35:
36: #include "includes.h"
1.54.2.2! miod 37: #include <sys/queue.h>
! 38: RCSID("$OpenBSD: ssh-agent.c,v 1.82 2002/03/04 17:27:39 stevesk Exp $");
1.47 markus 39:
40: #include <openssl/evp.h>
41: #include <openssl/md5.h>
1.1 deraadt 42:
43: #include "ssh.h"
44: #include "rsa.h"
45: #include "buffer.h"
46: #include "bufaux.h"
47: #include "xmalloc.h"
48: #include "getput.h"
1.32 markus 49: #include "key.h"
50: #include "authfd.h"
1.37 markus 51: #include "compat.h"
1.47 markus 52: #include "log.h"
1.7 deraadt 53:
1.54.2.1 jason 54: #ifdef SMARTCARD
55: #include <openssl/engine.h>
56: #include "scard.h"
57: #endif
58:
1.54.2.2! miod 59: typedef enum {
! 60: AUTH_UNUSED,
! 61: AUTH_SOCKET,
! 62: AUTH_CONNECTION
! 63: } sock_type;
! 64:
1.21 markus 65: typedef struct {
66: int fd;
1.54.2.2! miod 67: sock_type type;
1.21 markus 68: Buffer input;
69: Buffer output;
1.1 deraadt 70: } SocketEntry;
71:
1.45 markus 72: u_int sockets_alloc = 0;
1.1 deraadt 73: SocketEntry *sockets = NULL;
74:
1.54.2.2! miod 75: typedef struct identity {
! 76: TAILQ_ENTRY(identity) next;
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;
1.54.2.2! miod 83: TAILQ_HEAD(idqueue, identity) idlist;
1.33 markus 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:
1.54.2.1 jason 100: static void
1.33 markus 101: idtab_init(void)
1.1 deraadt 102: {
1.33 markus 103: int i;
1.54.2.2! miod 104: for (i = 0; i <=2; i++) {
! 105: TAILQ_INIT(&idtable[i].idlist);
1.33 markus 106: idtable[i].nentries = 0;
107: }
108: }
109:
110: /* return private key table for requested protocol version */
1.54.2.1 jason 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 */
1.54.2.2! miod 120: static Identity *
! 121: lookup_identity(Key *key, int version)
1.33 markus 122: {
1.54.2.2! miod 123: Identity *id;
! 124:
1.33 markus 125: Idtab *tab = idtab_lookup(version);
1.54.2.2! miod 126: TAILQ_FOREACH(id, &tab->idlist, next) {
! 127: if (key_equal(key, id->key))
! 128: return (id);
1.33 markus 129: }
1.54.2.2! miod 130: return (NULL);
! 131: }
! 132:
! 133: static void
! 134: free_identity(Identity *id)
! 135: {
! 136: key_free(id->key);
! 137: xfree(id->comment);
! 138: xfree(id);
1.33 markus 139: }
140:
141: /* send list of supported public keys to 'client' */
1.54.2.1 jason 142: static void
1.33 markus 143: process_request_identities(SocketEntry *e, int version)
144: {
145: Idtab *tab = idtab_lookup(version);
1.21 markus 146: Buffer msg;
1.54.2.2! miod 147: Identity *id;
1.1 deraadt 148:
1.21 markus 149: buffer_init(&msg);
1.33 markus 150: buffer_put_char(&msg, (version == 1) ?
151: SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
152: buffer_put_int(&msg, tab->nentries);
1.54.2.2! miod 153: TAILQ_FOREACH(id, &tab->idlist, next) {
1.39 markus 154: if (id->key->type == KEY_RSA1) {
1.33 markus 155: buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
156: buffer_put_bignum(&msg, id->key->rsa->e);
157: buffer_put_bignum(&msg, id->key->rsa->n);
158: } else {
1.45 markus 159: u_char *blob;
160: u_int blen;
1.39 markus 161: key_to_blob(id->key, &blob, &blen);
1.33 markus 162: buffer_put_string(&msg, blob, blen);
163: xfree(blob);
164: }
165: buffer_put_cstring(&msg, id->comment);
1.21 markus 166: }
167: buffer_put_int(&e->output, buffer_len(&msg));
168: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
169: buffer_free(&msg);
1.1 deraadt 170: }
171:
1.33 markus 172: /* ssh1 only */
1.54.2.1 jason 173: static void
1.33 markus 174: process_authentication_challenge1(SocketEntry *e)
1.1 deraadt 175: {
1.54.2.2! miod 176: Identity *id;
! 177: Key *key;
1.33 markus 178: BIGNUM *challenge;
179: int i, len;
1.21 markus 180: Buffer msg;
181: MD5_CTX md;
1.45 markus 182: u_char buf[32], mdbuf[16], session_id[16];
183: u_int response_type;
1.21 markus 184:
185: buffer_init(&msg);
1.39 markus 186: key = key_new(KEY_RSA1);
1.54.2.2! miod 187: if ((challenge = BN_new()) == NULL)
! 188: fatal("process_authentication_challenge1: BN_new failed");
1.33 markus 189:
190: buffer_get_int(&e->input); /* ignored */
191: buffer_get_bignum(&e->input, key->rsa->e);
192: buffer_get_bignum(&e->input, key->rsa->n);
1.21 markus 193: buffer_get_bignum(&e->input, challenge);
194:
1.33 markus 195: /* Only protocol 1.1 is supported */
196: if (buffer_len(&e->input) == 0)
197: goto failure;
1.54.2.2! miod 198: buffer_get(&e->input, session_id, 16);
1.33 markus 199: response_type = buffer_get_int(&e->input);
200: if (response_type != 1)
201: goto failure;
202:
1.54.2.2! miod 203: id = lookup_identity(key, 1);
! 204: if (id != NULL) {
! 205: Key *private = id->key;
1.33 markus 206: /* Decrypt the challenge using the private key. */
1.49 markus 207: if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
208: goto failure;
1.33 markus 209:
210: /* The response is MD5 of decrypted challenge plus session id. */
211: len = BN_num_bytes(challenge);
212: if (len <= 0 || len > 32) {
213: log("process_authentication_challenge: bad challenge length %d", len);
214: goto failure;
215: }
216: memset(buf, 0, 32);
217: BN_bn2bin(challenge, buf + 32 - len);
218: MD5_Init(&md);
219: MD5_Update(&md, buf, 32);
220: MD5_Update(&md, session_id, 16);
221: MD5_Final(mdbuf, &md);
222:
223: /* Send the response. */
224: buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
225: for (i = 0; i < 16; i++)
226: buffer_put_char(&msg, mdbuf[i]);
227: goto send;
228: }
1.21 markus 229:
1.33 markus 230: failure:
231: /* Unknown identity or protocol error. Send failure. */
1.21 markus 232: buffer_put_char(&msg, SSH_AGENT_FAILURE);
233: send:
234: buffer_put_int(&e->output, buffer_len(&msg));
1.33 markus 235: buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
236: key_free(key);
237: BN_clear_free(challenge);
238: buffer_free(&msg);
239: }
240:
241: /* ssh2 only */
1.54.2.1 jason 242: static void
1.33 markus 243: process_sign_request2(SocketEntry *e)
244: {
245: extern int datafellows;
1.54.2.2! miod 246: Key *key;
1.45 markus 247: u_char *blob, *data, *signature = NULL;
248: u_int blen, dlen, slen = 0;
1.37 markus 249: int flags;
1.33 markus 250: Buffer msg;
251: int ok = -1;
252:
253: datafellows = 0;
1.43 markus 254:
1.33 markus 255: blob = buffer_get_string(&e->input, &blen);
256: data = buffer_get_string(&e->input, &dlen);
1.37 markus 257:
258: flags = buffer_get_int(&e->input);
259: if (flags & SSH_AGENT_OLD_SIGNATURE)
260: datafellows = SSH_BUG_SIGBLOB;
1.33 markus 261:
1.39 markus 262: key = key_from_blob(blob, blen);
1.33 markus 263: if (key != NULL) {
1.54.2.2! miod 264: Identity *id = lookup_identity(key, 2);
! 265: if (id != NULL)
! 266: ok = key_sign(id->key, &signature, &slen, data, dlen);
1.33 markus 267: }
268: key_free(key);
269: buffer_init(&msg);
270: if (ok == 0) {
271: buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
272: buffer_put_string(&msg, signature, slen);
273: } else {
274: buffer_put_char(&msg, SSH_AGENT_FAILURE);
275: }
276: buffer_put_int(&e->output, buffer_len(&msg));
1.21 markus 277: buffer_append(&e->output, buffer_ptr(&msg),
1.33 markus 278: buffer_len(&msg));
1.21 markus 279: buffer_free(&msg);
1.33 markus 280: xfree(data);
281: xfree(blob);
282: if (signature != NULL)
283: xfree(signature);
1.1 deraadt 284: }
285:
1.33 markus 286: /* shared */
1.54.2.1 jason 287: static void
1.33 markus 288: process_remove_identity(SocketEntry *e, int version)
1.1 deraadt 289: {
1.54.2.2! miod 290: Key *key = NULL;
1.45 markus 291: u_char *blob;
292: u_int blen;
293: u_int bits;
1.33 markus 294: int success = 0;
1.21 markus 295:
1.54.2.2! miod 296: switch (version) {
1.33 markus 297: case 1:
1.39 markus 298: key = key_new(KEY_RSA1);
1.33 markus 299: bits = buffer_get_int(&e->input);
300: buffer_get_bignum(&e->input, key->rsa->e);
301: buffer_get_bignum(&e->input, key->rsa->n);
302:
303: if (bits != key_size(key))
304: log("Warning: identity keysize mismatch: actual %d, announced %d",
1.46 markus 305: key_size(key), bits);
1.33 markus 306: break;
307: case 2:
308: blob = buffer_get_string(&e->input, &blen);
1.39 markus 309: key = key_from_blob(blob, blen);
1.33 markus 310: xfree(blob);
311: break;
312: }
313: if (key != NULL) {
1.54.2.2! miod 314: Identity *id = lookup_identity(key, version);
! 315: if (id != NULL) {
1.23 markus 316: /*
317: * We have this key. Free the old key. Since we
318: * don\'t want to leave empty slots in the middle of
1.40 markus 319: * the array, we actually free the key there and move
320: * all the entries between the empty slot and the end
321: * of the array.
1.23 markus 322: */
1.33 markus 323: Idtab *tab = idtab_lookup(version);
1.38 markus 324: if (tab->nentries < 1)
325: fatal("process_remove_identity: "
326: "internal error: tab->nentries %d",
327: tab->nentries);
1.54.2.2! miod 328: TAILQ_REMOVE(&tab->idlist, id, next);
! 329: free_identity(id);
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:
1.54.2.1 jason 340: static void
1.33 markus 341: process_remove_all_identities(SocketEntry *e, int version)
1.1 deraadt 342: {
1.33 markus 343: Idtab *tab = idtab_lookup(version);
1.54.2.2! miod 344: Identity *id;
1.21 markus 345:
346: /* Loop over all identities and clear the keys. */
1.54.2.2! miod 347: for (id = TAILQ_FIRST(&tab->idlist); id;
! 348: id = TAILQ_FIRST(&tab->idlist)) {
! 349: TAILQ_REMOVE(&tab->idlist, id, next);
! 350: free_identity(id);
1.21 markus 351: }
352:
353: /* Mark that there are no identities. */
1.33 markus 354: tab->nentries = 0;
1.21 markus 355:
356: /* Send success. */
357: buffer_put_int(&e->output, 1);
358: buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
359: return;
1.1 deraadt 360: }
361:
1.54.2.1 jason 362: static void
1.33 markus 363: process_add_identity(SocketEntry *e, int version)
1.1 deraadt 364: {
1.33 markus 365: Key *k = NULL;
1.39 markus 366: char *type_name;
1.33 markus 367: char *comment;
1.39 markus 368: int type, success = 0;
1.33 markus 369: Idtab *tab = idtab_lookup(version);
370:
371: switch (version) {
372: case 1:
1.39 markus 373: k = key_new_private(KEY_RSA1);
1.46 markus 374: buffer_get_int(&e->input); /* ignored */
1.39 markus 375: buffer_get_bignum(&e->input, k->rsa->n);
376: buffer_get_bignum(&e->input, k->rsa->e);
377: buffer_get_bignum(&e->input, k->rsa->d);
378: buffer_get_bignum(&e->input, k->rsa->iqmp);
1.33 markus 379:
380: /* SSH and SSL have p and q swapped */
1.39 markus 381: buffer_get_bignum(&e->input, k->rsa->q); /* p */
382: buffer_get_bignum(&e->input, k->rsa->p); /* q */
1.33 markus 383:
384: /* Generate additional parameters */
1.54.2.1 jason 385: rsa_generate_additional_parameters(k->rsa);
1.33 markus 386: break;
387: case 2:
1.39 markus 388: type_name = buffer_get_string(&e->input, NULL);
1.46 markus 389: type = key_type_from_name(type_name);
1.39 markus 390: xfree(type_name);
1.54.2.2! miod 391: switch (type) {
1.39 markus 392: case KEY_DSA:
393: k = key_new_private(type);
394: buffer_get_bignum2(&e->input, k->dsa->p);
395: buffer_get_bignum2(&e->input, k->dsa->q);
396: buffer_get_bignum2(&e->input, k->dsa->g);
397: buffer_get_bignum2(&e->input, k->dsa->pub_key);
398: buffer_get_bignum2(&e->input, k->dsa->priv_key);
399: break;
400: case KEY_RSA:
401: k = key_new_private(type);
402: buffer_get_bignum2(&e->input, k->rsa->n);
403: buffer_get_bignum2(&e->input, k->rsa->e);
404: buffer_get_bignum2(&e->input, k->rsa->d);
405: buffer_get_bignum2(&e->input, k->rsa->iqmp);
406: buffer_get_bignum2(&e->input, k->rsa->p);
407: buffer_get_bignum2(&e->input, k->rsa->q);
408:
409: /* Generate additional parameters */
1.54.2.1 jason 410: rsa_generate_additional_parameters(k->rsa);
1.39 markus 411: break;
412: default:
1.33 markus 413: buffer_clear(&e->input);
414: goto send;
1.21 markus 415: }
1.33 markus 416: break;
417: }
418: comment = buffer_get_string(&e->input, NULL);
419: if (k == NULL) {
420: xfree(comment);
421: goto send;
422: }
423: success = 1;
1.54.2.2! miod 424: if (lookup_identity(k, version) == NULL) {
! 425: Identity *id = xmalloc(sizeof(Identity));
! 426: id->key = k;
! 427: id->comment = comment;
! 428: TAILQ_INSERT_TAIL(&tab->idlist, id, next);
1.33 markus 429: /* Increment the number of identities. */
430: tab->nentries++;
431: } else {
432: key_free(k);
433: xfree(comment);
434: }
435: send:
1.1 deraadt 436: buffer_put_int(&e->output, 1);
1.33 markus 437: buffer_put_char(&e->output,
438: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
1.1 deraadt 439: }
440:
1.54.2.1 jason 441:
442: #ifdef SMARTCARD
443: static void
444: process_add_smartcard_key (SocketEntry *e)
445: {
446: Idtab *tab;
447: Key *n = NULL, *k = NULL;
448: char *sc_reader_id = NULL;
449: int success = 0;
1.54.2.2! miod 450:
1.54.2.1 jason 451: sc_reader_id = buffer_get_string(&e->input, NULL);
452: k = sc_get_key(sc_reader_id);
453: xfree(sc_reader_id);
454:
455: if (k == NULL) {
456: error("sc_get_pubkey failed");
457: goto send;
458: }
459: success = 1;
460:
461: tab = idtab_lookup(1);
462: k->type = KEY_RSA1;
1.54.2.2! miod 463: if (lookup_identity(k, 1) == NULL) {
! 464: Identity *id = xmalloc(sizeof(Identity));
1.54.2.1 jason 465: n = key_new(KEY_RSA1);
466: BN_copy(n->rsa->n, k->rsa->n);
467: BN_copy(n->rsa->e, k->rsa->e);
468: RSA_set_method(n->rsa, sc_get_engine());
1.54.2.2! miod 469: id->key = n;
! 470: id->comment = xstrdup("rsa1 smartcard");
! 471: TAILQ_INSERT_TAIL(&tab->idlist, id, next);
1.54.2.1 jason 472: tab->nentries++;
473: }
474: k->type = KEY_RSA;
475: tab = idtab_lookup(2);
1.54.2.2! miod 476: if (lookup_identity(k, 2) == NULL) {
! 477: Identity *id = xmalloc(sizeof(Identity));
1.54.2.1 jason 478: n = key_new(KEY_RSA);
479: BN_copy(n->rsa->n, k->rsa->n);
480: BN_copy(n->rsa->e, k->rsa->e);
481: RSA_set_method(n->rsa, sc_get_engine());
1.54.2.2! miod 482: id->key = n;
! 483: id->comment = xstrdup("rsa smartcard");
! 484: TAILQ_INSERT_TAIL(&tab->idlist, id, next);
1.54.2.1 jason 485: tab->nentries++;
486: }
487: key_free(k);
488: send:
489: buffer_put_int(&e->output, 1);
490: buffer_put_char(&e->output,
491: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
492: }
493:
494: static void
495: process_remove_smartcard_key(SocketEntry *e)
496: {
1.54.2.2! miod 497: Key *k = NULL;
1.54.2.1 jason 498: int success = 0;
499: char *sc_reader_id = NULL;
500:
501: sc_reader_id = buffer_get_string(&e->input, NULL);
502: k = sc_get_key(sc_reader_id);
503: xfree(sc_reader_id);
504:
505: if (k == NULL) {
506: error("sc_get_pubkey failed");
507: } else {
1.54.2.2! miod 508: Identity *id;
1.54.2.1 jason 509: k->type = KEY_RSA1;
1.54.2.2! miod 510: id = lookup_identity(k, 1);
! 511: if (id != NULL) {
1.54.2.1 jason 512: Idtab *tab = idtab_lookup(1);
1.54.2.2! miod 513: TAILQ_REMOVE(&tab->idlist, id, next);
! 514: free_identity(id);
1.54.2.1 jason 515: tab->nentries--;
516: success = 1;
517: }
518: k->type = KEY_RSA;
1.54.2.2! miod 519: id = lookup_identity(k, 2);
! 520: if (id != NULL) {
1.54.2.1 jason 521: Idtab *tab = idtab_lookup(2);
1.54.2.2! miod 522: TAILQ_REMOVE(&tab->idlist, id, next);
! 523: free_identity(id);
1.54.2.1 jason 524: tab->nentries--;
525: success = 1;
526: }
527: key_free(k);
528: }
529:
530: buffer_put_int(&e->output, 1);
531: buffer_put_char(&e->output,
532: success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
533: }
534: #endif /* SMARTCARD */
535:
1.33 markus 536: /* dispatch incoming messages */
537:
1.54.2.1 jason 538: static void
1.2 provos 539: process_message(SocketEntry *e)
1.1 deraadt 540: {
1.45 markus 541: u_int msg_len;
542: u_int type;
543: u_char *cp;
1.21 markus 544: if (buffer_len(&e->input) < 5)
545: return; /* Incomplete message. */
1.54.2.2! miod 546: cp = buffer_ptr(&e->input);
1.21 markus 547: msg_len = GET_32BIT(cp);
548: if (msg_len > 256 * 1024) {
549: shutdown(e->fd, SHUT_RDWR);
550: close(e->fd);
551: e->type = AUTH_UNUSED;
552: return;
553: }
554: if (buffer_len(&e->input) < msg_len + 4)
555: return;
556: buffer_consume(&e->input, 4);
557: type = buffer_get_char(&e->input);
558:
1.54.2.1 jason 559: debug("type %d", type);
1.21 markus 560: switch (type) {
1.33 markus 561: /* ssh1 */
562: case SSH_AGENTC_RSA_CHALLENGE:
563: process_authentication_challenge1(e);
564: break;
1.21 markus 565: case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
1.33 markus 566: process_request_identities(e, 1);
1.21 markus 567: break;
568: case SSH_AGENTC_ADD_RSA_IDENTITY:
1.33 markus 569: process_add_identity(e, 1);
1.21 markus 570: break;
571: case SSH_AGENTC_REMOVE_RSA_IDENTITY:
1.33 markus 572: process_remove_identity(e, 1);
1.21 markus 573: break;
574: case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
1.33 markus 575: process_remove_all_identities(e, 1);
576: break;
577: /* ssh2 */
578: case SSH2_AGENTC_SIGN_REQUEST:
579: process_sign_request2(e);
580: break;
581: case SSH2_AGENTC_REQUEST_IDENTITIES:
582: process_request_identities(e, 2);
583: break;
584: case SSH2_AGENTC_ADD_IDENTITY:
585: process_add_identity(e, 2);
586: break;
587: case SSH2_AGENTC_REMOVE_IDENTITY:
588: process_remove_identity(e, 2);
589: break;
590: case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
591: process_remove_all_identities(e, 2);
1.21 markus 592: break;
1.54.2.1 jason 593: #ifdef SMARTCARD
594: case SSH_AGENTC_ADD_SMARTCARD_KEY:
595: process_add_smartcard_key(e);
1.54.2.2! miod 596: break;
1.54.2.1 jason 597: case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
598: process_remove_smartcard_key(e);
1.54.2.2! miod 599: break;
1.54.2.1 jason 600: #endif /* SMARTCARD */
1.21 markus 601: default:
602: /* Unknown message. Respond with failure. */
603: error("Unknown message %d", type);
604: buffer_clear(&e->input);
605: buffer_put_int(&e->output, 1);
606: buffer_put_char(&e->output, SSH_AGENT_FAILURE);
607: break;
608: }
1.1 deraadt 609: }
610:
1.54.2.1 jason 611: static void
1.54.2.2! miod 612: new_socket(sock_type type, int fd)
1.1 deraadt 613: {
1.45 markus 614: u_int i, old_alloc;
1.21 markus 615: if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
616: error("fcntl O_NONBLOCK: %s", strerror(errno));
617:
618: if (fd > max_fd)
619: max_fd = fd;
620:
621: for (i = 0; i < sockets_alloc; i++)
622: if (sockets[i].type == AUTH_UNUSED) {
623: sockets[i].fd = fd;
624: sockets[i].type = type;
625: buffer_init(&sockets[i].input);
626: buffer_init(&sockets[i].output);
627: return;
628: }
629: old_alloc = sockets_alloc;
630: sockets_alloc += 10;
631: if (sockets)
632: sockets = xrealloc(sockets, sockets_alloc * sizeof(sockets[0]));
633: else
634: sockets = xmalloc(sockets_alloc * sizeof(sockets[0]));
635: for (i = old_alloc; i < sockets_alloc; i++)
636: sockets[i].type = AUTH_UNUSED;
637: sockets[old_alloc].type = type;
638: sockets[old_alloc].fd = fd;
639: buffer_init(&sockets[old_alloc].input);
640: buffer_init(&sockets[old_alloc].output);
1.1 deraadt 641: }
642:
1.54.2.1 jason 643: static int
644: prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp)
1.1 deraadt 645: {
1.46 markus 646: u_int i, sz;
647: int n = 0;
648:
649: for (i = 0; i < sockets_alloc; i++) {
1.21 markus 650: switch (sockets[i].type) {
651: case AUTH_SOCKET:
652: case AUTH_CONNECTION:
1.46 markus 653: n = MAX(n, sockets[i].fd);
1.21 markus 654: break;
655: case AUTH_UNUSED:
656: break;
657: default:
658: fatal("Unknown socket type %d", sockets[i].type);
659: break;
660: }
1.46 markus 661: }
662:
663: sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
1.54.2.1 jason 664: if (*fdrp == NULL || sz > *nallocp) {
1.46 markus 665: if (*fdrp)
1.54 stevesk 666: xfree(*fdrp);
1.46 markus 667: if (*fdwp)
1.54 stevesk 668: xfree(*fdwp);
1.46 markus 669: *fdrp = xmalloc(sz);
670: *fdwp = xmalloc(sz);
1.54.2.1 jason 671: *nallocp = sz;
1.46 markus 672: }
1.54.2.1 jason 673: if (n < *fdl)
674: debug("XXX shrink: %d < %d", n, *fdl);
675: *fdl = n;
1.46 markus 676: memset(*fdrp, 0, sz);
677: memset(*fdwp, 0, sz);
678:
679: for (i = 0; i < sockets_alloc; i++) {
680: switch (sockets[i].type) {
681: case AUTH_SOCKET:
682: case AUTH_CONNECTION:
683: FD_SET(sockets[i].fd, *fdrp);
684: if (buffer_len(&sockets[i].output) > 0)
685: FD_SET(sockets[i].fd, *fdwp);
686: break;
687: default:
688: break;
689: }
690: }
691: return (1);
1.21 markus 692: }
693:
1.54.2.1 jason 694: static void
1.21 markus 695: after_select(fd_set *readset, fd_set *writeset)
696: {
1.45 markus 697: u_int i;
1.21 markus 698: int len, sock;
1.26 markus 699: socklen_t slen;
1.21 markus 700: char buf[1024];
701: struct sockaddr_un sunaddr;
702:
703: for (i = 0; i < sockets_alloc; i++)
704: switch (sockets[i].type) {
705: case AUTH_UNUSED:
706: break;
707: case AUTH_SOCKET:
708: if (FD_ISSET(sockets[i].fd, readset)) {
1.26 markus 709: slen = sizeof(sunaddr);
1.46 markus 710: sock = accept(sockets[i].fd,
711: (struct sockaddr *) &sunaddr, &slen);
1.21 markus 712: if (sock < 0) {
1.54.2.2! miod 713: error("accept from AUTH_SOCKET: %s",
! 714: strerror(errno));
1.21 markus 715: break;
716: }
717: new_socket(AUTH_CONNECTION, sock);
718: }
719: break;
720: case AUTH_CONNECTION:
721: if (buffer_len(&sockets[i].output) > 0 &&
722: FD_ISSET(sockets[i].fd, writeset)) {
1.52 deraadt 723: do {
724: len = write(sockets[i].fd,
725: buffer_ptr(&sockets[i].output),
726: buffer_len(&sockets[i].output));
727: if (len == -1 && (errno == EAGAIN ||
728: errno == EINTR))
729: continue;
730: break;
731: } while (1);
1.21 markus 732: if (len <= 0) {
733: shutdown(sockets[i].fd, SHUT_RDWR);
734: close(sockets[i].fd);
735: sockets[i].type = AUTH_UNUSED;
1.30 djm 736: buffer_free(&sockets[i].input);
737: buffer_free(&sockets[i].output);
1.21 markus 738: break;
739: }
740: buffer_consume(&sockets[i].output, len);
741: }
742: if (FD_ISSET(sockets[i].fd, readset)) {
1.52 deraadt 743: do {
744: len = read(sockets[i].fd, buf, sizeof(buf));
745: if (len == -1 && (errno == EAGAIN ||
746: errno == EINTR))
747: continue;
748: break;
749: } while (1);
1.21 markus 750: if (len <= 0) {
751: shutdown(sockets[i].fd, SHUT_RDWR);
752: close(sockets[i].fd);
753: sockets[i].type = AUTH_UNUSED;
1.30 djm 754: buffer_free(&sockets[i].input);
755: buffer_free(&sockets[i].output);
1.21 markus 756: break;
757: }
758: buffer_append(&sockets[i].input, buf, len);
759: process_message(&sockets[i]);
760: }
761: break;
762: default:
763: fatal("Unknown type %d", sockets[i].type);
764: }
1.1 deraadt 765: }
766:
1.54.2.1 jason 767: static void
1.54.2.2! miod 768: cleanup_socket(void *p)
1.15 markus 769: {
1.48 deraadt 770: if (socket_name[0])
771: unlink(socket_name);
772: if (socket_dir[0])
773: rmdir(socket_dir);
1.10 markus 774: }
775:
1.54.2.1 jason 776: static void
1.15 markus 777: cleanup_exit(int i)
778: {
1.54.2.2! miod 779: cleanup_socket(NULL);
1.21 markus 780: exit(i);
1.15 markus 781: }
782:
1.54.2.1 jason 783: static void
1.48 deraadt 784: cleanup_handler(int sig)
785: {
1.54.2.2! miod 786: cleanup_socket(NULL);
1.48 deraadt 787: _exit(2);
788: }
789:
1.54.2.1 jason 790: static void
791: check_parent_exists(int sig)
792: {
793: int save_errno = errno;
794:
795: if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
796: /* printf("Parent has died - Authentication agent exiting.\n"); */
797: cleanup_handler(sig); /* safe */
798: }
799: signal(SIGALRM, check_parent_exists);
800: alarm(10);
801: errno = save_errno;
802: }
803:
804: static void
1.50 itojun 805: usage(void)
1.15 markus 806: {
1.54.2.1 jason 807: fprintf(stderr, "Usage: %s [options] [command [args ...]]\n",
1.46 markus 808: __progname);
1.54.2.1 jason 809: fprintf(stderr, "Options:\n");
810: fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
811: fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
812: fprintf(stderr, " -k Kill the current agent.\n");
813: fprintf(stderr, " -d Debug mode.\n");
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: {
1.54.2.1 jason 820: int sock, c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0, ch, nalloc;
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:
1.54.2.1 jason 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;
1.54.2.1 jason 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:
1.54.2.1 jason 857: if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1.21 markus 858: usage();
859:
1.54.2.1 jason 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: */
1.54.2.1 jason 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");
1.54.2.2! miod 935: cleanup_exit(1);
1.21 markus 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: }
1.54.2.2! miod 958: /* child */
! 959: log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1.54.2.1 jason 960:
961: if (setsid() == -1) {
1.54.2.2! miod 962: error("setsid: %s", strerror(errno));
1.54.2.1 jason 963: cleanup_exit(1);
964: }
965:
966: (void)chdir("/");
1.21 markus 967: close(0);
968: close(1);
969: close(2);
970:
1.41 markus 971: /* deny core dumps, since memory contains unencrypted private keys */
972: rlim.rlim_cur = rlim.rlim_max = 0;
973: if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1.54.2.2! miod 974: error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1.41 markus 975: cleanup_exit(1);
976: }
1.54.2.1 jason 977:
978: skip:
1.54.2.2! miod 979: fatal_add_cleanup(cleanup_socket, NULL);
1.21 markus 980: new_socket(AUTH_SOCKET, sock);
981: if (ac > 0) {
982: signal(SIGALRM, check_parent_exists);
983: alarm(10);
984: }
1.33 markus 985: idtab_init();
1.54.2.1 jason 986: if (!d_flag)
987: signal(SIGINT, SIG_IGN);
1.21 markus 988: signal(SIGPIPE, SIG_IGN);
1.48 deraadt 989: signal(SIGHUP, cleanup_handler);
990: signal(SIGTERM, cleanup_handler);
1.54.2.1 jason 991: nalloc = 0;
992:
1.21 markus 993: while (1) {
1.54.2.1 jason 994: prepare_select(&readsetp, &writesetp, &max_fd, &nalloc);
1.46 markus 995: if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) {
1.21 markus 996: if (errno == EINTR)
997: continue;
1.54.2.2! miod 998: fatal("select: %s", strerror(errno));
1.21 markus 999: }
1.46 markus 1000: after_select(readsetp, writesetp);
1.15 markus 1001: }
1.21 markus 1002: /* NOTREACHED */
1.1 deraadt 1003: }
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