Annotation of src/usr.bin/ssh/sshconnect1.c, Revision 1.46
1.1 markus 1: /*
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: * Code to connect to a remote host, and to perform the client side of the
6: * login (authentication) dialog.
7: *
1.6 deraadt 8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
1.1 markus 13: */
14:
15: #include "includes.h"
1.46 ! markus 16: RCSID("$OpenBSD: sshconnect1.c,v 1.45 2001/12/28 12:14:27 markus Exp $");
1.1 markus 17:
18: #include <openssl/bn.h>
19: #include <openssl/evp.h>
20:
1.18 markus 21: #ifdef KRB4
22: #include <krb.h>
23: #endif
1.37 dugsong 24: #ifdef KRB5
25: #include <krb5.h>
26: #endif
1.18 markus 27: #ifdef AFS
28: #include <kafs.h>
1.19 markus 29: #include "radix.h"
1.18 markus 30: #endif
31:
32: #include "ssh.h"
33: #include "ssh1.h"
1.1 markus 34: #include "xmalloc.h"
35: #include "rsa.h"
36: #include "buffer.h"
37: #include "packet.h"
38: #include "mpaux.h"
39: #include "uidswap.h"
1.18 markus 40: #include "log.h"
1.1 markus 41: #include "readconf.h"
42: #include "key.h"
1.4 markus 43: #include "authfd.h"
1.1 markus 44: #include "sshconnect.h"
45: #include "authfile.h"
1.18 markus 46: #include "readpass.h"
47: #include "cipher.h"
48: #include "canohost.h"
1.37 dugsong 49: #include "auth.h"
1.1 markus 50:
51: /* Session id for the current session. */
1.13 markus 52: u_char session_id[16];
53: u_int supported_authentications = 0;
1.1 markus 54:
55: extern Options options;
56: extern char *__progname;
57:
58: /*
59: * Checks if the user has an authentication agent, and if so, tries to
60: * authenticate using the agent.
61: */
1.35 itojun 62: static int
1.24 itojun 63: try_agent_authentication(void)
1.1 markus 64: {
1.5 markus 65: int type;
1.1 markus 66: char *comment;
67: AuthenticationConnection *auth;
1.13 markus 68: u_char response[16];
69: u_int i;
1.46 ! markus 70: int plen;
1.5 markus 71: Key *key;
72: BIGNUM *challenge;
1.1 markus 73:
74: /* Get connection to the agent. */
75: auth = ssh_get_authentication_connection();
76: if (!auth)
77: return 0;
78:
1.43 markus 79: if ((challenge = BN_new()) == NULL)
80: fatal("try_agent_authentication: BN_new failed");
1.1 markus 81: /* Loop through identities served by the agent. */
1.5 markus 82: for (key = ssh_get_first_identity(auth, &comment, 1);
1.42 deraadt 83: key != NULL;
84: key = ssh_get_next_identity(auth, &comment, 1)) {
1.1 markus 85:
86: /* Try this identity. */
87: debug("Trying RSA authentication via agent with '%.100s'", comment);
88: xfree(comment);
89:
90: /* Tell the server that we are willing to authenticate using this key. */
91: packet_start(SSH_CMSG_AUTH_RSA);
1.5 markus 92: packet_put_bignum(key->rsa->n);
1.1 markus 93: packet_send();
94: packet_write_wait();
95:
96: /* Wait for server's response. */
97: type = packet_read(&plen);
98:
99: /* The server sends failure if it doesn\'t like our key or
100: does not support RSA authentication. */
101: if (type == SSH_SMSG_FAILURE) {
102: debug("Server refused our key.");
1.5 markus 103: key_free(key);
1.1 markus 104: continue;
105: }
106: /* Otherwise it should have sent a challenge. */
107: if (type != SSH_SMSG_AUTH_RSA_CHALLENGE)
108: packet_disconnect("Protocol error during RSA authentication: %d",
109: type);
110:
1.46 ! markus 111: packet_get_bignum(challenge);
1.45 markus 112: packet_check_eom();
1.1 markus 113:
114: debug("Received RSA challenge from server.");
115:
116: /* Ask the agent to decrypt the challenge. */
1.5 markus 117: if (!ssh_decrypt_challenge(auth, key, challenge, session_id, 1, response)) {
118: /*
119: * The agent failed to authenticate this identifier
120: * although it advertised it supports this. Just
121: * return a wrong value.
122: */
1.1 markus 123: log("Authentication agent failed to decrypt challenge.");
124: memset(response, 0, sizeof(response));
125: }
1.5 markus 126: key_free(key);
1.1 markus 127: debug("Sending response to RSA challenge.");
128:
129: /* Send the decrypted challenge back to the server. */
130: packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
131: for (i = 0; i < 16; i++)
132: packet_put_char(response[i]);
133: packet_send();
134: packet_write_wait();
135:
136: /* Wait for response from the server. */
137: type = packet_read(&plen);
138:
139: /* The server returns success if it accepted the authentication. */
140: if (type == SSH_SMSG_SUCCESS) {
1.14 markus 141: ssh_close_authentication_connection(auth);
1.5 markus 142: BN_clear_free(challenge);
1.1 markus 143: debug("RSA authentication accepted by server.");
144: return 1;
145: }
146: /* Otherwise it should return failure. */
147: if (type != SSH_SMSG_FAILURE)
148: packet_disconnect("Protocol error waiting RSA auth response: %d",
149: type);
150: }
1.14 markus 151: ssh_close_authentication_connection(auth);
1.1 markus 152: BN_clear_free(challenge);
153: debug("RSA authentication using agent refused.");
154: return 0;
155: }
156:
157: /*
158: * Computes the proper response to a RSA challenge, and sends the response to
159: * the server.
160: */
1.35 itojun 161: static void
1.1 markus 162: respond_to_rsa_challenge(BIGNUM * challenge, RSA * prv)
163: {
1.13 markus 164: u_char buf[32], response[16];
1.1 markus 165: MD5_CTX md;
166: int i, len;
167:
168: /* Decrypt the challenge using the private key. */
1.21 markus 169: /* XXX think about Bleichenbacher, too */
170: if (rsa_private_decrypt(challenge, challenge, prv) <= 0)
171: packet_disconnect(
172: "respond_to_rsa_challenge: rsa_private_decrypt failed");
1.1 markus 173:
174: /* Compute the response. */
175: /* The response is MD5 of decrypted challenge plus session id. */
176: len = BN_num_bytes(challenge);
177: if (len <= 0 || len > sizeof(buf))
1.21 markus 178: packet_disconnect(
179: "respond_to_rsa_challenge: bad challenge length %d", len);
1.1 markus 180:
181: memset(buf, 0, sizeof(buf));
182: BN_bn2bin(challenge, buf + sizeof(buf) - len);
183: MD5_Init(&md);
184: MD5_Update(&md, buf, 32);
185: MD5_Update(&md, session_id, 16);
186: MD5_Final(response, &md);
187:
188: debug("Sending response to host key RSA challenge.");
189:
190: /* Send the response back to the server. */
191: packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
192: for (i = 0; i < 16; i++)
193: packet_put_char(response[i]);
194: packet_send();
195: packet_write_wait();
196:
197: memset(buf, 0, sizeof(buf));
198: memset(response, 0, sizeof(response));
199: memset(&md, 0, sizeof(md));
200: }
201:
202: /*
203: * Checks if the user has authentication file, and if so, tries to authenticate
204: * the user using it.
205: */
1.35 itojun 206: static int
1.38 markus 207: try_rsa_authentication(int idx)
1.1 markus 208: {
209: BIGNUM *challenge;
1.36 markus 210: Key *public, *private;
1.38 markus 211: char buf[300], *passphrase, *comment, *authfile;
1.46 ! markus 212: int i, type, quit, plen;
1.1 markus 213:
1.38 markus 214: public = options.identity_keys[idx];
215: authfile = options.identity_files[idx];
216: comment = xstrdup(authfile);
217:
1.1 markus 218: debug("Trying RSA authentication with key '%.100s'", comment);
219:
220: /* Tell the server that we are willing to authenticate using this key. */
221: packet_start(SSH_CMSG_AUTH_RSA);
222: packet_put_bignum(public->rsa->n);
223: packet_send();
224: packet_write_wait();
225:
226: /* Wait for server's response. */
227: type = packet_read(&plen);
228:
229: /*
230: * The server responds with failure if it doesn\'t like our key or
231: * doesn\'t support RSA authentication.
232: */
233: if (type == SSH_SMSG_FAILURE) {
234: debug("Server refused our key.");
235: xfree(comment);
236: return 0;
237: }
238: /* Otherwise, the server should respond with a challenge. */
239: if (type != SSH_SMSG_AUTH_RSA_CHALLENGE)
240: packet_disconnect("Protocol error during RSA authentication: %d", type);
241:
242: /* Get the challenge from the packet. */
1.43 markus 243: if ((challenge = BN_new()) == NULL)
244: fatal("try_rsa_authentication: BN_new failed");
1.46 ! markus 245: packet_get_bignum(challenge);
1.45 markus 246: packet_check_eom();
1.1 markus 247:
248: debug("Received RSA challenge from server.");
249:
250: /*
1.38 markus 251: * If the key is not stored in external hardware, we have to
252: * load the private key. Try first with empty passphrase; if it
1.1 markus 253: * fails, ask for a passphrase.
254: */
1.38 markus 255: if (public->flags && KEY_FLAG_EXT)
256: private = public;
257: else
258: private = key_load_private_type(KEY_RSA1, authfile, "", NULL);
1.36 markus 259: if (private == NULL && !options.batch_mode) {
260: snprintf(buf, sizeof(buf),
261: "Enter passphrase for RSA key '%.100s': ", comment);
262: for (i = 0; i < options.number_of_password_prompts; i++) {
1.1 markus 263: passphrase = read_passphrase(buf, 0);
1.36 markus 264: if (strcmp(passphrase, "") != 0) {
265: private = key_load_private_type(KEY_RSA1,
266: authfile, passphrase, NULL);
267: quit = 0;
268: } else {
269: debug2("no passphrase given, try next key");
270: quit = 1;
271: }
1.1 markus 272: memset(passphrase, 0, strlen(passphrase));
273: xfree(passphrase);
1.36 markus 274: if (private != NULL || quit)
275: break;
276: debug2("bad passphrase given, try again...");
1.1 markus 277: }
278: }
279: /* We no longer need the comment. */
280: xfree(comment);
1.36 markus 281:
282: if (private == NULL) {
283: if (!options.batch_mode)
284: error("Bad passphrase.");
285:
286: /* Send a dummy response packet to avoid protocol error. */
287: packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
288: for (i = 0; i < 16; i++)
289: packet_put_char(0);
290: packet_send();
291: packet_write_wait();
292:
293: /* Expect the server to reject it... */
294: packet_read_expect(&plen, SSH_SMSG_FAILURE);
295: BN_clear_free(challenge);
296: return 0;
297: }
1.1 markus 298:
299: /* Compute and send a response to the challenge. */
300: respond_to_rsa_challenge(challenge, private->rsa);
301:
1.38 markus 302: /* Destroy the private key unless it in external hardware. */
303: if (!(private->flags & KEY_FLAG_EXT))
304: key_free(private);
1.1 markus 305:
306: /* We no longer need the challenge. */
307: BN_clear_free(challenge);
308:
309: /* Wait for response from the server. */
310: type = packet_read(&plen);
311: if (type == SSH_SMSG_SUCCESS) {
312: debug("RSA authentication accepted by server.");
313: return 1;
314: }
315: if (type != SSH_SMSG_FAILURE)
316: packet_disconnect("Protocol error waiting RSA auth response: %d", type);
317: debug("RSA authentication refused.");
318: return 0;
319: }
320:
321: /*
322: * Tries to authenticate the user using combined rhosts or /etc/hosts.equiv
323: * authentication and RSA host authentication.
324: */
1.35 itojun 325: static int
1.29 markus 326: try_rhosts_rsa_authentication(const char *local_user, Key * host_key)
1.1 markus 327: {
328: int type;
329: BIGNUM *challenge;
1.46 ! markus 330: int plen;
1.1 markus 331:
332: debug("Trying rhosts or /etc/hosts.equiv with RSA host authentication.");
333:
334: /* Tell the server that we are willing to authenticate using this key. */
335: packet_start(SSH_CMSG_AUTH_RHOSTS_RSA);
1.33 markus 336: packet_put_cstring(local_user);
1.29 markus 337: packet_put_int(BN_num_bits(host_key->rsa->n));
338: packet_put_bignum(host_key->rsa->e);
339: packet_put_bignum(host_key->rsa->n);
1.1 markus 340: packet_send();
341: packet_write_wait();
342:
343: /* Wait for server's response. */
344: type = packet_read(&plen);
345:
346: /* The server responds with failure if it doesn't admit our
347: .rhosts authentication or doesn't know our host key. */
348: if (type == SSH_SMSG_FAILURE) {
349: debug("Server refused our rhosts authentication or host key.");
350: return 0;
351: }
352: /* Otherwise, the server should respond with a challenge. */
353: if (type != SSH_SMSG_AUTH_RSA_CHALLENGE)
354: packet_disconnect("Protocol error during RSA authentication: %d", type);
355:
356: /* Get the challenge from the packet. */
1.43 markus 357: if ((challenge = BN_new()) == NULL)
358: fatal("try_rhosts_rsa_authentication: BN_new failed");
1.46 ! markus 359: packet_get_bignum(challenge);
1.45 markus 360: packet_check_eom();
1.1 markus 361:
362: debug("Received RSA challenge for host key from server.");
363:
364: /* Compute a response to the challenge. */
1.29 markus 365: respond_to_rsa_challenge(challenge, host_key->rsa);
1.1 markus 366:
367: /* We no longer need the challenge. */
368: BN_clear_free(challenge);
369:
370: /* Wait for response from the server. */
371: type = packet_read(&plen);
372: if (type == SSH_SMSG_SUCCESS) {
373: debug("Rhosts or /etc/hosts.equiv with RSA host authentication accepted by server.");
374: return 1;
375: }
376: if (type != SSH_SMSG_FAILURE)
377: packet_disconnect("Protocol error waiting RSA auth response: %d", type);
378: debug("Rhosts or /etc/hosts.equiv with RSA host authentication refused.");
379: return 0;
380: }
381:
382: #ifdef KRB4
1.35 itojun 383: static int
1.37 dugsong 384: try_krb4_authentication(void)
1.1 markus 385: {
386: KTEXT_ST auth; /* Kerberos data */
387: char *reply;
388: char inst[INST_SZ];
389: char *realm;
390: CREDENTIALS cred;
391: int r, type, plen;
392: socklen_t slen;
393: Key_schedule schedule;
394: u_long checksum, cksum;
395: MSG_DAT msg_data;
396: struct sockaddr_in local, foreign;
397: struct stat st;
398:
399: /* Don't do anything if we don't have any tickets. */
400: if (stat(tkt_string(), &st) < 0)
401: return 0;
1.42 deraadt 402:
1.37 dugsong 403: strlcpy(inst, (char *)krb_get_phost(get_canonical_hostname(1)),
404: INST_SZ);
1.42 deraadt 405:
1.37 dugsong 406: realm = (char *)krb_realmofhost(get_canonical_hostname(1));
1.1 markus 407: if (!realm) {
1.37 dugsong 408: debug("Kerberos v4: no realm for %s", get_canonical_hostname(1));
1.1 markus 409: return 0;
410: }
411: /* This can really be anything. */
1.37 dugsong 412: checksum = (u_long)getpid();
1.42 deraadt 413:
1.1 markus 414: r = krb_mk_req(&auth, KRB4_SERVICE_NAME, inst, realm, checksum);
415: if (r != KSUCCESS) {
1.37 dugsong 416: debug("Kerberos v4 krb_mk_req failed: %s", krb_err_txt[r]);
1.1 markus 417: return 0;
418: }
419: /* Get session key to decrypt the server's reply with. */
420: r = krb_get_cred(KRB4_SERVICE_NAME, inst, realm, &cred);
421: if (r != KSUCCESS) {
422: debug("get_cred failed: %s", krb_err_txt[r]);
423: return 0;
424: }
425: des_key_sched((des_cblock *) cred.session, schedule);
1.42 deraadt 426:
1.1 markus 427: /* Send authentication info to server. */
428: packet_start(SSH_CMSG_AUTH_KERBEROS);
429: packet_put_string((char *) auth.dat, auth.length);
430: packet_send();
431: packet_write_wait();
1.42 deraadt 432:
1.1 markus 433: /* Zero the buffer. */
434: (void) memset(auth.dat, 0, MAX_KTXT_LEN);
1.42 deraadt 435:
1.1 markus 436: slen = sizeof(local);
437: memset(&local, 0, sizeof(local));
438: if (getsockname(packet_get_connection_in(),
1.37 dugsong 439: (struct sockaddr *)&local, &slen) < 0)
1.1 markus 440: debug("getsockname failed: %s", strerror(errno));
1.42 deraadt 441:
1.1 markus 442: slen = sizeof(foreign);
443: memset(&foreign, 0, sizeof(foreign));
444: if (getpeername(packet_get_connection_in(),
1.37 dugsong 445: (struct sockaddr *)&foreign, &slen) < 0) {
1.1 markus 446: debug("getpeername failed: %s", strerror(errno));
447: fatal_cleanup();
448: }
449: /* Get server reply. */
450: type = packet_read(&plen);
451: switch (type) {
452: case SSH_SMSG_FAILURE:
453: /* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
1.37 dugsong 454: debug("Kerberos v4 authentication failed.");
1.1 markus 455: return 0;
456: break;
1.42 deraadt 457:
1.1 markus 458: case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
459: /* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
1.37 dugsong 460: debug("Kerberos v4 authentication accepted.");
1.42 deraadt 461:
1.1 markus 462: /* Get server's response. */
1.13 markus 463: reply = packet_get_string((u_int *) &auth.length);
1.1 markus 464: memcpy(auth.dat, reply, auth.length);
465: xfree(reply);
1.42 deraadt 466:
1.45 markus 467: packet_check_eom();
1.42 deraadt 468:
1.1 markus 469: /*
470: * If his response isn't properly encrypted with the session
471: * key, and the decrypted checksum fails to match, he's
472: * bogus. Bail out.
473: */
474: r = krb_rd_priv(auth.dat, auth.length, schedule, &cred.session,
1.37 dugsong 475: &foreign, &local, &msg_data);
1.1 markus 476: if (r != KSUCCESS) {
1.37 dugsong 477: debug("Kerberos v4 krb_rd_priv failed: %s",
478: krb_err_txt[r]);
479: packet_disconnect("Kerberos v4 challenge failed!");
1.1 markus 480: }
481: /* Fetch the (incremented) checksum that we supplied in the request. */
1.37 dugsong 482: memcpy((char *)&cksum, (char *)msg_data.app_data,
483: sizeof(cksum));
1.1 markus 484: cksum = ntohl(cksum);
1.42 deraadt 485:
1.1 markus 486: /* If it matches, we're golden. */
487: if (cksum == checksum + 1) {
1.37 dugsong 488: debug("Kerberos v4 challenge successful.");
1.1 markus 489: return 1;
490: } else
1.37 dugsong 491: packet_disconnect("Kerberos v4 challenge failed!");
1.1 markus 492: break;
1.42 deraadt 493:
1.1 markus 494: default:
1.37 dugsong 495: packet_disconnect("Protocol error on Kerberos v4 response: %d", type);
1.1 markus 496: }
497: return 0;
498: }
499:
500: #endif /* KRB4 */
501:
1.37 dugsong 502: #ifdef KRB5
503: static int
504: try_krb5_authentication(krb5_context *context, krb5_auth_context *auth_context)
505: {
506: krb5_error_code problem;
507: const char *tkfile;
508: struct stat buf;
509: krb5_ccache ccache = NULL;
510: const char *remotehost;
511: krb5_data ap;
512: int type, payload_len;
513: krb5_ap_rep_enc_part *reply = NULL;
514: int ret;
1.42 deraadt 515:
1.37 dugsong 516: memset(&ap, 0, sizeof(ap));
1.42 deraadt 517:
1.37 dugsong 518: problem = krb5_init_context(context);
519: if (problem) {
520: debug("Kerberos v5: krb5_init_context failed");
521: ret = 0;
522: goto out;
523: }
1.42 deraadt 524:
1.37 dugsong 525: tkfile = krb5_cc_default_name(*context);
526: if (strncmp(tkfile, "FILE:", 5) == 0)
527: tkfile += 5;
1.42 deraadt 528:
1.37 dugsong 529: if (stat(tkfile, &buf) == 0 && getuid() != buf.st_uid) {
530: debug("Kerberos v5: could not get default ccache (permission denied).");
531: ret = 0;
532: goto out;
533: }
1.42 deraadt 534:
1.37 dugsong 535: problem = krb5_cc_default(*context, &ccache);
536: if (problem) {
537: debug("Kerberos v5: krb5_cc_default failed: %s",
538: krb5_get_err_text(*context, problem));
539: ret = 0;
540: goto out;
541: }
1.42 deraadt 542:
1.37 dugsong 543: remotehost = get_canonical_hostname(1);
1.42 deraadt 544:
1.37 dugsong 545: problem = krb5_mk_req(*context, auth_context, AP_OPTS_MUTUAL_REQUIRED,
546: "host", remotehost, NULL, ccache, &ap);
547: if (problem) {
548: debug("Kerberos v5: krb5_mk_req failed: %s",
549: krb5_get_err_text(*context, problem));
550: ret = 0;
551: goto out;
552: }
1.42 deraadt 553:
1.37 dugsong 554: packet_start(SSH_CMSG_AUTH_KERBEROS);
555: packet_put_string((char *) ap.data, ap.length);
556: packet_send();
557: packet_write_wait();
1.42 deraadt 558:
1.37 dugsong 559: xfree(ap.data);
560: ap.length = 0;
1.42 deraadt 561:
1.37 dugsong 562: type = packet_read(&payload_len);
563: switch (type) {
1.42 deraadt 564: case SSH_SMSG_FAILURE:
565: /* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
566: debug("Kerberos v5 authentication failed.");
567: ret = 0;
568: break;
569:
1.37 dugsong 570: case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
1.42 deraadt 571: /* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
572: debug("Kerberos v5 authentication accepted.");
573:
574: /* Get server's response. */
575: ap.data = packet_get_string((unsigned int *) &ap.length);
1.45 markus 576: packet_check_eom();
1.42 deraadt 577: /* XXX je to dobre? */
578:
579: problem = krb5_rd_rep(*context, *auth_context, &ap, &reply);
580: if (problem) {
1.37 dugsong 581: ret = 0;
582: }
583: ret = 1;
584: break;
1.42 deraadt 585:
1.37 dugsong 586: default:
587: packet_disconnect("Protocol error on Kerberos v5 response: %d",
588: type);
589: ret = 0;
590: break;
1.42 deraadt 591:
1.37 dugsong 592: }
1.42 deraadt 593:
1.37 dugsong 594: out:
595: if (ccache != NULL)
596: krb5_cc_close(*context, ccache);
597: if (reply != NULL)
598: krb5_free_ap_rep_enc_part(*context, reply);
599: if (ap.length > 0)
600: krb5_data_free(&ap);
1.42 deraadt 601:
1.37 dugsong 602: return (ret);
603: }
604:
605: static void
606: send_krb5_tgt(krb5_context context, krb5_auth_context auth_context)
607: {
608: int fd, type, payload_len;
609: krb5_error_code problem;
610: krb5_data outbuf;
611: krb5_ccache ccache = NULL;
612: krb5_creds creds;
613: krb5_kdc_flags flags;
614: const char *remotehost;
1.42 deraadt 615:
1.37 dugsong 616: memset(&creds, 0, sizeof(creds));
617: memset(&outbuf, 0, sizeof(outbuf));
1.42 deraadt 618:
1.37 dugsong 619: fd = packet_get_connection_in();
1.42 deraadt 620:
1.37 dugsong 621: problem = krb5_auth_con_setaddrs_from_fd(context, auth_context, &fd);
622: if (problem)
623: goto out;
1.42 deraadt 624:
1.37 dugsong 625: problem = krb5_cc_default(context, &ccache);
626: if (problem)
627: goto out;
1.42 deraadt 628:
1.37 dugsong 629: problem = krb5_cc_get_principal(context, ccache, &creds.client);
630: if (problem)
631: goto out;
1.42 deraadt 632:
1.37 dugsong 633: problem = krb5_build_principal(context, &creds.server,
634: strlen(creds.client->realm), creds.client->realm,
635: "krbtgt", creds.client->realm, NULL);
636: if (problem)
637: goto out;
1.42 deraadt 638:
1.37 dugsong 639: creds.times.endtime = 0;
1.42 deraadt 640:
1.37 dugsong 641: flags.i = 0;
642: flags.b.forwarded = 1;
643: flags.b.forwardable = krb5_config_get_bool(context, NULL,
644: "libdefaults", "forwardable", NULL);
1.42 deraadt 645:
1.37 dugsong 646: remotehost = get_canonical_hostname(1);
1.42 deraadt 647:
1.37 dugsong 648: problem = krb5_get_forwarded_creds(context, auth_context,
649: ccache, flags.i, remotehost, &creds, &outbuf);
650: if (problem)
651: goto out;
1.42 deraadt 652:
1.37 dugsong 653: packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
654: packet_put_string((char *)outbuf.data, outbuf.length);
655: packet_send();
656: packet_write_wait();
1.42 deraadt 657:
1.37 dugsong 658: type = packet_read(&payload_len);
1.42 deraadt 659:
1.37 dugsong 660: if (type == SSH_SMSG_SUCCESS) {
661: char *pname;
1.42 deraadt 662:
1.37 dugsong 663: krb5_unparse_name(context, creds.client, &pname);
664: debug("Kerberos v5 TGT forwarded (%s).", pname);
665: xfree(pname);
666: } else
667: debug("Kerberos v5 TGT forwarding failed.");
1.42 deraadt 668:
1.37 dugsong 669: return;
1.42 deraadt 670:
1.37 dugsong 671: out:
672: if (problem)
673: debug("Kerberos v5 TGT forwarding failed: %s",
674: krb5_get_err_text(context, problem));
675: if (creds.client)
676: krb5_free_principal(context, creds.client);
677: if (creds.server)
678: krb5_free_principal(context, creds.server);
679: if (ccache)
680: krb5_cc_close(context, ccache);
681: if (outbuf.data)
682: xfree(outbuf.data);
683: }
684: #endif /* KRB5 */
685:
1.1 markus 686: #ifdef AFS
1.37 dugsong 687: static void
688: send_krb4_tgt(void)
1.1 markus 689: {
690: CREDENTIALS *creds;
691: struct stat st;
1.37 dugsong 692: char buffer[4096], pname[ANAME_SZ], pinst[INST_SZ], prealm[REALM_SZ];
693: int problem, type, len;
1.42 deraadt 694:
1.1 markus 695: /* Don't do anything if we don't have any tickets. */
696: if (stat(tkt_string(), &st) < 0)
1.37 dugsong 697: return;
1.42 deraadt 698:
1.1 markus 699: creds = xmalloc(sizeof(*creds));
1.42 deraadt 700:
1.37 dugsong 701: problem = krb_get_tf_fullname(TKT_FILE, pname, pinst, prealm);
702: if (problem)
703: goto out;
1.42 deraadt 704:
1.37 dugsong 705: problem = krb_get_cred("krbtgt", prealm, prealm, creds);
706: if (problem)
707: goto out;
1.42 deraadt 708:
1.1 markus 709: if (time(0) > krb_life_to_time(creds->issue_date, creds->lifetime)) {
1.37 dugsong 710: problem = RD_AP_EXP;
711: goto out;
1.1 markus 712: }
1.37 dugsong 713: creds_to_radix(creds, (u_char *)buffer, sizeof(buffer));
1.42 deraadt 714:
1.1 markus 715: packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
1.33 markus 716: packet_put_cstring(buffer);
1.1 markus 717: packet_send();
718: packet_write_wait();
1.42 deraadt 719:
1.37 dugsong 720: type = packet_read(&len);
1.42 deraadt 721:
1.37 dugsong 722: if (type == SSH_SMSG_SUCCESS)
723: debug("Kerberos v4 TGT forwarded (%s%s%s@%s).",
724: creds->pname, creds->pinst[0] ? "." : "",
725: creds->pinst, creds->realm);
726: else
727: debug("Kerberos v4 TGT rejected.");
1.42 deraadt 728:
1.37 dugsong 729: xfree(creds);
730: return;
1.42 deraadt 731:
1.37 dugsong 732: out:
733: debug("Kerberos v4 TGT passing failed: %s", krb_err_txt[problem]);
734: xfree(creds);
1.1 markus 735: }
736:
1.35 itojun 737: static void
1.1 markus 738: send_afs_tokens(void)
739: {
740: CREDENTIALS creds;
741: struct ViceIoctl parms;
742: struct ClearToken ct;
1.37 dugsong 743: int i, type, len;
1.1 markus 744: char buf[2048], *p, *server_cell;
745: char buffer[8192];
1.42 deraadt 746:
1.1 markus 747: /* Move over ktc_GetToken, here's something leaner. */
748: for (i = 0; i < 100; i++) { /* just in case */
749: parms.in = (char *) &i;
750: parms.in_size = sizeof(i);
751: parms.out = buf;
752: parms.out_size = sizeof(buf);
753: if (k_pioctl(0, VIOCGETTOK, &parms, 0) != 0)
754: break;
755: p = buf;
1.42 deraadt 756:
1.1 markus 757: /* Get secret token. */
1.13 markus 758: memcpy(&creds.ticket_st.length, p, sizeof(u_int));
1.1 markus 759: if (creds.ticket_st.length > MAX_KTXT_LEN)
760: break;
1.13 markus 761: p += sizeof(u_int);
1.1 markus 762: memcpy(creds.ticket_st.dat, p, creds.ticket_st.length);
763: p += creds.ticket_st.length;
1.42 deraadt 764:
1.1 markus 765: /* Get clear token. */
766: memcpy(&len, p, sizeof(len));
767: if (len != sizeof(struct ClearToken))
768: break;
769: p += sizeof(len);
770: memcpy(&ct, p, len);
771: p += len;
772: p += sizeof(len); /* primary flag */
773: server_cell = p;
1.42 deraadt 774:
1.1 markus 775: /* Flesh out our credentials. */
1.37 dugsong 776: strlcpy(creds.service, "afs", sizeof(creds.service));
1.1 markus 777: creds.instance[0] = '\0';
778: strlcpy(creds.realm, server_cell, REALM_SZ);
779: memcpy(creds.session, ct.HandShakeKey, DES_KEY_SZ);
780: creds.issue_date = ct.BeginTimestamp;
1.37 dugsong 781: creds.lifetime = krb_time_to_life(creds.issue_date,
782: ct.EndTimestamp);
1.1 markus 783: creds.kvno = ct.AuthHandle;
784: snprintf(creds.pname, sizeof(creds.pname), "AFS ID %d", ct.ViceId);
785: creds.pinst[0] = '\0';
1.42 deraadt 786:
1.1 markus 787: /* Encode token, ship it off. */
1.37 dugsong 788: if (creds_to_radix(&creds, (u_char *)buffer,
789: sizeof(buffer)) <= 0)
1.1 markus 790: break;
791: packet_start(SSH_CMSG_HAVE_AFS_TOKEN);
1.33 markus 792: packet_put_cstring(buffer);
1.1 markus 793: packet_send();
794: packet_write_wait();
795:
796: /* Roger, Roger. Clearance, Clarence. What's your vector,
797: Victor? */
1.37 dugsong 798: type = packet_read(&len);
1.42 deraadt 799:
1.1 markus 800: if (type == SSH_SMSG_FAILURE)
801: debug("AFS token for cell %s rejected.", server_cell);
802: else if (type != SSH_SMSG_SUCCESS)
803: packet_disconnect("Protocol error on AFS token response: %d", type);
804: }
805: }
806:
807: #endif /* AFS */
808:
809: /*
810: * Tries to authenticate with any string-based challenge/response system.
811: * Note that the client code is not tied to s/key or TIS.
812: */
1.35 itojun 813: static int
1.32 markus 814: try_challenge_response_authentication(void)
1.1 markus 815: {
816: int type, i;
817: int payload_len;
1.13 markus 818: u_int clen;
1.12 markus 819: char prompt[1024];
1.1 markus 820: char *challenge, *response;
1.40 markus 821:
822: debug("Doing challenge response authentication.");
823:
1.12 markus 824: for (i = 0; i < options.number_of_password_prompts; i++) {
825: /* request a challenge */
826: packet_start(SSH_CMSG_AUTH_TIS);
827: packet_send();
828: packet_write_wait();
1.1 markus 829:
1.12 markus 830: type = packet_read(&payload_len);
831: if (type != SSH_SMSG_FAILURE &&
832: type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
833: packet_disconnect("Protocol error: got %d in response "
1.20 markus 834: "to SSH_CMSG_AUTH_TIS", type);
1.12 markus 835: }
836: if (type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
1.20 markus 837: debug("No challenge.");
1.12 markus 838: return 0;
839: }
840: challenge = packet_get_string(&clen);
1.45 markus 841: packet_check_eom();
1.16 markus 842: snprintf(prompt, sizeof prompt, "%s%s", challenge,
1.42 deraadt 843: strchr(challenge, '\n') ? "" : "\nResponse: ");
1.12 markus 844: xfree(challenge);
1.1 markus 845: if (i != 0)
846: error("Permission denied, please try again.");
1.12 markus 847: if (options.cipher == SSH_CIPHER_NONE)
848: log("WARNING: Encryption is disabled! "
849: "Reponse will be transmitted in clear text.");
850: response = read_passphrase(prompt, 0);
851: if (strcmp(response, "") == 0) {
852: xfree(response);
853: break;
854: }
1.1 markus 855: packet_start(SSH_CMSG_AUTH_TIS_RESPONSE);
1.27 markus 856: ssh_put_password(response);
1.1 markus 857: memset(response, 0, strlen(response));
858: xfree(response);
859: packet_send();
860: packet_write_wait();
861: type = packet_read(&payload_len);
862: if (type == SSH_SMSG_SUCCESS)
863: return 1;
864: if (type != SSH_SMSG_FAILURE)
865: packet_disconnect("Protocol error: got %d in response "
1.20 markus 866: "to SSH_CMSG_AUTH_TIS_RESPONSE", type);
1.1 markus 867: }
868: /* failure */
869: return 0;
870: }
871:
872: /*
873: * Tries to authenticate with plain passwd authentication.
874: */
1.35 itojun 875: static int
1.1 markus 876: try_password_authentication(char *prompt)
877: {
878: int type, i, payload_len;
879: char *password;
880:
881: debug("Doing password authentication.");
882: if (options.cipher == SSH_CIPHER_NONE)
883: log("WARNING: Encryption is disabled! Password will be transmitted in clear text.");
884: for (i = 0; i < options.number_of_password_prompts; i++) {
885: if (i != 0)
886: error("Permission denied, please try again.");
887: password = read_passphrase(prompt, 0);
888: packet_start(SSH_CMSG_AUTH_PASSWORD);
1.27 markus 889: ssh_put_password(password);
1.1 markus 890: memset(password, 0, strlen(password));
891: xfree(password);
892: packet_send();
893: packet_write_wait();
894:
895: type = packet_read(&payload_len);
896: if (type == SSH_SMSG_SUCCESS)
897: return 1;
898: if (type != SSH_SMSG_FAILURE)
899: packet_disconnect("Protocol error: got %d in response to passwd auth", type);
900: }
901: /* failure */
902: return 0;
903: }
904:
905: /*
906: * SSH1 key exchange
907: */
908: void
909: ssh_kex(char *host, struct sockaddr *hostaddr)
910: {
911: int i;
912: BIGNUM *key;
1.43 markus 913: Key *host_key, *server_key;
1.1 markus 914: int bits, rbits;
915: int ssh_cipher_default = SSH_CIPHER_3DES;
1.13 markus 916: u_char session_key[SSH_SESSION_KEY_LENGTH];
917: u_char cookie[8];
918: u_int supported_ciphers;
919: u_int server_flags, client_flags;
1.46 ! markus 920: int payload_len;
1.1 markus 921: u_int32_t rand = 0;
922:
923: debug("Waiting for server public key.");
924:
925: /* Wait for a public key packet from the server. */
926: packet_read_expect(&payload_len, SSH_SMSG_PUBLIC_KEY);
927:
928: /* Get cookie from the packet. */
929: for (i = 0; i < 8; i++)
930: cookie[i] = packet_get_char();
931:
932: /* Get the public key. */
1.43 markus 933: server_key = key_new(KEY_RSA1);
934: bits = packet_get_int();
1.46 ! markus 935: packet_get_bignum(server_key->rsa->e);
! 936: packet_get_bignum(server_key->rsa->n);
1.1 markus 937:
1.43 markus 938: rbits = BN_num_bits(server_key->rsa->n);
1.1 markus 939: if (bits != rbits) {
940: log("Warning: Server lies about size of server public key: "
941: "actual size is %d bits vs. announced %d.", rbits, bits);
942: log("Warning: This may be due to an old implementation of ssh.");
943: }
944: /* Get the host key. */
1.43 markus 945: host_key = key_new(KEY_RSA1);
946: bits = packet_get_int();
1.46 ! markus 947: packet_get_bignum(host_key->rsa->e);
! 948: packet_get_bignum(host_key->rsa->n);
1.1 markus 949:
1.43 markus 950: rbits = BN_num_bits(host_key->rsa->n);
1.1 markus 951: if (bits != rbits) {
952: log("Warning: Server lies about size of server host key: "
953: "actual size is %d bits vs. announced %d.", rbits, bits);
954: log("Warning: This may be due to an old implementation of ssh.");
955: }
956:
957: /* Get protocol flags. */
958: server_flags = packet_get_int();
959: packet_set_protocol_flags(server_flags);
960:
961: supported_ciphers = packet_get_int();
962: supported_authentications = packet_get_int();
1.45 markus 963: packet_check_eom();
1.1 markus 964:
965: debug("Received server public key (%d bits) and host key (%d bits).",
1.43 markus 966: BN_num_bits(server_key->rsa->n), BN_num_bits(host_key->rsa->n));
1.1 markus 967:
1.43 markus 968: if (verify_host_key(host, hostaddr, host_key) == -1)
1.41 markus 969: fatal("Host key verification failed.");
1.1 markus 970:
971: client_flags = SSH_PROTOFLAG_SCREEN_NUMBER | SSH_PROTOFLAG_HOST_IN_FWD_OPEN;
972:
1.43 markus 973: compute_session_id(session_id, cookie, host_key->rsa->n, server_key->rsa->n);
1.1 markus 974:
975: /* Generate a session key. */
976: arc4random_stir();
977:
978: /*
979: * Generate an encryption key for the session. The key is a 256 bit
980: * random number, interpreted as a 32-byte key, with the least
981: * significant 8 bits being the first byte of the key.
982: */
983: for (i = 0; i < 32; i++) {
984: if (i % 4 == 0)
985: rand = arc4random();
986: session_key[i] = rand & 0xff;
987: rand >>= 8;
988: }
989:
990: /*
991: * According to the protocol spec, the first byte of the session key
992: * is the highest byte of the integer. The session key is xored with
993: * the first 16 bytes of the session id.
994: */
1.43 markus 995: if ((key = BN_new()) == NULL)
996: fatal("respond_to_rsa_challenge: BN_new failed");
1.1 markus 997: BN_set_word(key, 0);
998: for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
999: BN_lshift(key, key, 8);
1000: if (i < 16)
1001: BN_add_word(key, session_key[i] ^ session_id[i]);
1002: else
1003: BN_add_word(key, session_key[i]);
1004: }
1005:
1006: /*
1007: * Encrypt the integer using the public key and host key of the
1008: * server (key with smaller modulus first).
1009: */
1.43 markus 1010: if (BN_cmp(server_key->rsa->n, host_key->rsa->n) < 0) {
1.1 markus 1011: /* Public key has smaller modulus. */
1.43 markus 1012: if (BN_num_bits(host_key->rsa->n) <
1013: BN_num_bits(server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1014: fatal("respond_to_rsa_challenge: host_key %d < server_key %d + "
1.42 deraadt 1015: "SSH_KEY_BITS_RESERVED %d",
1.43 markus 1016: BN_num_bits(host_key->rsa->n),
1017: BN_num_bits(server_key->rsa->n),
1.42 deraadt 1018: SSH_KEY_BITS_RESERVED);
1.1 markus 1019: }
1.43 markus 1020: rsa_public_encrypt(key, key, server_key->rsa);
1021: rsa_public_encrypt(key, key, host_key->rsa);
1.1 markus 1022: } else {
1023: /* Host key has smaller modulus (or they are equal). */
1.43 markus 1024: if (BN_num_bits(server_key->rsa->n) <
1025: BN_num_bits(host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1026: fatal("respond_to_rsa_challenge: server_key %d < host_key %d + "
1.42 deraadt 1027: "SSH_KEY_BITS_RESERVED %d",
1.43 markus 1028: BN_num_bits(server_key->rsa->n),
1029: BN_num_bits(host_key->rsa->n),
1.42 deraadt 1030: SSH_KEY_BITS_RESERVED);
1.1 markus 1031: }
1.43 markus 1032: rsa_public_encrypt(key, key, host_key->rsa);
1033: rsa_public_encrypt(key, key, server_key->rsa);
1.1 markus 1034: }
1035:
1036: /* Destroy the public keys since we no longer need them. */
1.43 markus 1037: key_free(server_key);
1038: key_free(host_key);
1.1 markus 1039:
1.11 markus 1040: if (options.cipher == SSH_CIPHER_NOT_SET) {
1041: if (cipher_mask_ssh1(1) & supported_ciphers & (1 << ssh_cipher_default))
1042: options.cipher = ssh_cipher_default;
1043: } else if (options.cipher == SSH_CIPHER_ILLEGAL ||
1.10 markus 1044: !(cipher_mask_ssh1(1) & (1 << options.cipher))) {
1.3 markus 1045: log("No valid SSH1 cipher, using %.100s instead.",
1.7 markus 1046: cipher_name(ssh_cipher_default));
1047: options.cipher = ssh_cipher_default;
1.1 markus 1048: }
1049: /* Check that the selected cipher is supported. */
1050: if (!(supported_ciphers & (1 << options.cipher)))
1051: fatal("Selected cipher type %.100s not supported by server.",
1.42 deraadt 1052: cipher_name(options.cipher));
1.1 markus 1053:
1054: debug("Encryption type: %.100s", cipher_name(options.cipher));
1055:
1056: /* Send the encrypted session key to the server. */
1057: packet_start(SSH_CMSG_SESSION_KEY);
1058: packet_put_char(options.cipher);
1059:
1060: /* Send the cookie back to the server. */
1061: for (i = 0; i < 8; i++)
1062: packet_put_char(cookie[i]);
1063:
1064: /* Send and destroy the encrypted encryption key integer. */
1065: packet_put_bignum(key);
1066: BN_clear_free(key);
1067:
1068: /* Send protocol flags. */
1069: packet_put_int(client_flags);
1070:
1071: /* Send the packet now. */
1072: packet_send();
1073: packet_write_wait();
1074:
1075: debug("Sent encrypted session key.");
1076:
1077: /* Set the encryption key. */
1078: packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, options.cipher);
1079:
1080: /* We will no longer need the session key here. Destroy any extra copies. */
1081: memset(session_key, 0, sizeof(session_key));
1082:
1083: /*
1084: * Expect a success message from the server. Note that this message
1085: * will be received in encrypted form.
1086: */
1087: packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
1088:
1089: debug("Received encrypted confirmation.");
1090: }
1091:
1092: /*
1093: * Authenticate user
1094: */
1095: void
1.30 markus 1096: ssh_userauth1(const char *local_user, const char *server_user, char *host,
1097: Key **keys, int nkeys)
1.1 markus 1098: {
1.37 dugsong 1099: #ifdef KRB5
1100: krb5_context context = NULL;
1101: krb5_auth_context auth_context = NULL;
1102: #endif
1.1 markus 1103: int i, type;
1104: int payload_len;
1.42 deraadt 1105:
1.1 markus 1106: if (supported_authentications == 0)
1.30 markus 1107: fatal("ssh_userauth1: server supports no auth methods");
1.1 markus 1108:
1109: /* Send the name of the user to log in as on the server. */
1110: packet_start(SSH_CMSG_USER);
1.33 markus 1111: packet_put_cstring(server_user);
1.1 markus 1112: packet_send();
1113: packet_write_wait();
1114:
1115: /*
1116: * The server should respond with success if no authentication is
1117: * needed (the user has no password). Otherwise the server responds
1118: * with failure.
1119: */
1120: type = packet_read(&payload_len);
1121:
1122: /* check whether the connection was accepted without authentication. */
1123: if (type == SSH_SMSG_SUCCESS)
1.37 dugsong 1124: goto success;
1.1 markus 1125: if (type != SSH_SMSG_FAILURE)
1.37 dugsong 1126: packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER", type);
1.42 deraadt 1127:
1.37 dugsong 1128: #ifdef KRB5
1129: if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) &&
1.42 deraadt 1130: options.kerberos_authentication) {
1.37 dugsong 1131: debug("Trying Kerberos v5 authentication.");
1.42 deraadt 1132:
1.37 dugsong 1133: if (try_krb5_authentication(&context, &auth_context)) {
1134: type = packet_read(&payload_len);
1135: if (type == SSH_SMSG_SUCCESS)
1136: goto success;
1137: if (type != SSH_SMSG_FAILURE)
1138: packet_disconnect("Protocol error: got %d in response to Kerberos v5 auth", type);
1139: }
1.1 markus 1140: }
1.37 dugsong 1141: #endif /* KRB5 */
1.42 deraadt 1142:
1.1 markus 1143: #ifdef KRB4
1144: if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) &&
1145: options.kerberos_authentication) {
1.37 dugsong 1146: debug("Trying Kerberos v4 authentication.");
1.42 deraadt 1147:
1.37 dugsong 1148: if (try_krb4_authentication()) {
1.1 markus 1149: type = packet_read(&payload_len);
1150: if (type == SSH_SMSG_SUCCESS)
1.37 dugsong 1151: goto success;
1.1 markus 1152: if (type != SSH_SMSG_FAILURE)
1.37 dugsong 1153: packet_disconnect("Protocol error: got %d in response to Kerberos v4 auth", type);
1.1 markus 1154: }
1155: }
1156: #endif /* KRB4 */
1.42 deraadt 1157:
1.1 markus 1158: /*
1159: * Use rhosts authentication if running in privileged socket and we
1160: * do not wish to remain anonymous.
1161: */
1162: if ((supported_authentications & (1 << SSH_AUTH_RHOSTS)) &&
1163: options.rhosts_authentication) {
1164: debug("Trying rhosts authentication.");
1165: packet_start(SSH_CMSG_AUTH_RHOSTS);
1.33 markus 1166: packet_put_cstring(local_user);
1.1 markus 1167: packet_send();
1168: packet_write_wait();
1169:
1170: /* The server should respond with success or failure. */
1171: type = packet_read(&payload_len);
1172: if (type == SSH_SMSG_SUCCESS)
1.37 dugsong 1173: goto success;
1.1 markus 1174: if (type != SSH_SMSG_FAILURE)
1175: packet_disconnect("Protocol error: got %d in response to rhosts auth",
1176: type);
1177: }
1178: /*
1179: * Try .rhosts or /etc/hosts.equiv authentication with RSA host
1180: * authentication.
1181: */
1182: if ((supported_authentications & (1 << SSH_AUTH_RHOSTS_RSA)) &&
1.30 markus 1183: options.rhosts_rsa_authentication) {
1184: for (i = 0; i < nkeys; i++) {
1.31 markus 1185: if (keys[i] != NULL && keys[i]->type == KEY_RSA1 &&
1.30 markus 1186: try_rhosts_rsa_authentication(local_user, keys[i]))
1.37 dugsong 1187: goto success;
1.30 markus 1188: }
1.1 markus 1189: }
1190: /* Try RSA authentication if the server supports it. */
1191: if ((supported_authentications & (1 << SSH_AUTH_RSA)) &&
1192: options.rsa_authentication) {
1193: /*
1194: * Try RSA authentication using the authentication agent. The
1195: * agent is tried first because no passphrase is needed for
1196: * it, whereas identity files may require passphrases.
1197: */
1198: if (try_agent_authentication())
1.37 dugsong 1199: goto success;
1.1 markus 1200:
1201: /* Try RSA authentication for each identity. */
1202: for (i = 0; i < options.num_identity_files; i++)
1.28 markus 1203: if (options.identity_keys[i] != NULL &&
1204: options.identity_keys[i]->type == KEY_RSA1 &&
1.38 markus 1205: try_rsa_authentication(i))
1.37 dugsong 1206: goto success;
1.1 markus 1207: }
1.20 markus 1208: /* Try challenge response authentication if the server supports it. */
1.1 markus 1209: if ((supported_authentications & (1 << SSH_AUTH_TIS)) &&
1.32 markus 1210: options.challenge_response_authentication && !options.batch_mode) {
1211: if (try_challenge_response_authentication())
1.37 dugsong 1212: goto success;
1.1 markus 1213: }
1214: /* Try password authentication if the server supports it. */
1215: if ((supported_authentications & (1 << SSH_AUTH_PASSWORD)) &&
1216: options.password_authentication && !options.batch_mode) {
1217: char prompt[80];
1218:
1.23 itojun 1219: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.1 markus 1220: server_user, host);
1221: if (try_password_authentication(prompt))
1.37 dugsong 1222: goto success;
1.1 markus 1223: }
1224: /* All authentication methods have failed. Exit with an error message. */
1225: fatal("Permission denied.");
1226: /* NOTREACHED */
1.37 dugsong 1227:
1228: success:
1229: #ifdef KRB5
1230: /* Try Kerberos v5 TGT passing. */
1231: if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) &&
1232: options.kerberos_tgt_passing && context && auth_context) {
1233: if (options.cipher == SSH_CIPHER_NONE)
1234: log("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
1235: send_krb5_tgt(context, auth_context);
1236: }
1237: if (auth_context)
1238: krb5_auth_con_free(context, auth_context);
1239: if (context)
1240: krb5_free_context(context);
1241: #endif
1.42 deraadt 1242:
1.37 dugsong 1243: #ifdef AFS
1244: /* Try Kerberos v4 TGT passing if the server supports it. */
1245: if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) &&
1246: options.kerberos_tgt_passing) {
1247: if (options.cipher == SSH_CIPHER_NONE)
1248: log("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
1249: send_krb4_tgt();
1250: }
1251: /* Try AFS token passing if the server supports it. */
1252: if ((supported_authentications & (1 << SSH_PASS_AFS_TOKEN)) &&
1253: options.afs_token_passing && k_hasafs()) {
1254: if (options.cipher == SSH_CIPHER_NONE)
1255: log("WARNING: Encryption is disabled! Token will be transmitted in the clear!");
1256: send_afs_tokens();
1257: }
1258: #endif /* AFS */
1.39 stevesk 1259:
1260: return; /* need statement after label */
1.1 markus 1261: }
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