Annotation of src/usr.bin/ssh/sshconnect1.c, Revision 1.42
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"
1.42 ! deraadt 16: RCSID("$OpenBSD: sshconnect1.c,v 1.41 2001/10/06 11:18:19 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;
1.5 markus 70: int plen, clen;
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:
79: challenge = BN_new();
80:
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:
111: packet_get_bignum(challenge, &clen);
112:
113: packet_integrity_check(plen, clen, type);
114:
115: debug("Received RSA challenge from server.");
116:
117: /* Ask the agent to decrypt the challenge. */
1.5 markus 118: if (!ssh_decrypt_challenge(auth, key, challenge, session_id, 1, response)) {
119: /*
120: * The agent failed to authenticate this identifier
121: * although it advertised it supports this. Just
122: * return a wrong value.
123: */
1.1 markus 124: log("Authentication agent failed to decrypt challenge.");
125: memset(response, 0, sizeof(response));
126: }
1.5 markus 127: key_free(key);
1.1 markus 128: debug("Sending response to RSA challenge.");
129:
130: /* Send the decrypted challenge back to the server. */
131: packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
132: for (i = 0; i < 16; i++)
133: packet_put_char(response[i]);
134: packet_send();
135: packet_write_wait();
136:
137: /* Wait for response from the server. */
138: type = packet_read(&plen);
139:
140: /* The server returns success if it accepted the authentication. */
141: if (type == SSH_SMSG_SUCCESS) {
1.14 markus 142: ssh_close_authentication_connection(auth);
1.5 markus 143: BN_clear_free(challenge);
1.1 markus 144: debug("RSA authentication accepted by server.");
145: return 1;
146: }
147: /* Otherwise it should return failure. */
148: if (type != SSH_SMSG_FAILURE)
149: packet_disconnect("Protocol error waiting RSA auth response: %d",
150: type);
151: }
1.14 markus 152: ssh_close_authentication_connection(auth);
1.1 markus 153: BN_clear_free(challenge);
154: debug("RSA authentication using agent refused.");
155: return 0;
156: }
157:
158: /*
159: * Computes the proper response to a RSA challenge, and sends the response to
160: * the server.
161: */
1.35 itojun 162: static void
1.1 markus 163: respond_to_rsa_challenge(BIGNUM * challenge, RSA * prv)
164: {
1.13 markus 165: u_char buf[32], response[16];
1.1 markus 166: MD5_CTX md;
167: int i, len;
168:
169: /* Decrypt the challenge using the private key. */
1.21 markus 170: /* XXX think about Bleichenbacher, too */
171: if (rsa_private_decrypt(challenge, challenge, prv) <= 0)
172: packet_disconnect(
173: "respond_to_rsa_challenge: rsa_private_decrypt failed");
1.1 markus 174:
175: /* Compute the response. */
176: /* The response is MD5 of decrypted challenge plus session id. */
177: len = BN_num_bytes(challenge);
178: if (len <= 0 || len > sizeof(buf))
1.21 markus 179: packet_disconnect(
180: "respond_to_rsa_challenge: bad challenge length %d", len);
1.1 markus 181:
182: memset(buf, 0, sizeof(buf));
183: BN_bn2bin(challenge, buf + sizeof(buf) - len);
184: MD5_Init(&md);
185: MD5_Update(&md, buf, 32);
186: MD5_Update(&md, session_id, 16);
187: MD5_Final(response, &md);
188:
189: debug("Sending response to host key RSA challenge.");
190:
191: /* Send the response back to the server. */
192: packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
193: for (i = 0; i < 16; i++)
194: packet_put_char(response[i]);
195: packet_send();
196: packet_write_wait();
197:
198: memset(buf, 0, sizeof(buf));
199: memset(response, 0, sizeof(response));
200: memset(&md, 0, sizeof(md));
201: }
202:
203: /*
204: * Checks if the user has authentication file, and if so, tries to authenticate
205: * the user using it.
206: */
1.35 itojun 207: static int
1.38 markus 208: try_rsa_authentication(int idx)
1.1 markus 209: {
210: BIGNUM *challenge;
1.36 markus 211: Key *public, *private;
1.38 markus 212: char buf[300], *passphrase, *comment, *authfile;
1.36 markus 213: int i, type, quit, plen, clen;
1.1 markus 214:
1.38 markus 215: public = options.identity_keys[idx];
216: authfile = options.identity_files[idx];
217: comment = xstrdup(authfile);
218:
1.1 markus 219: debug("Trying RSA authentication with key '%.100s'", comment);
220:
221: /* Tell the server that we are willing to authenticate using this key. */
222: packet_start(SSH_CMSG_AUTH_RSA);
223: packet_put_bignum(public->rsa->n);
224: packet_send();
225: packet_write_wait();
226:
227: /* Wait for server's response. */
228: type = packet_read(&plen);
229:
230: /*
231: * The server responds with failure if it doesn\'t like our key or
232: * doesn\'t support RSA authentication.
233: */
234: if (type == SSH_SMSG_FAILURE) {
235: debug("Server refused our key.");
236: xfree(comment);
237: return 0;
238: }
239: /* Otherwise, the server should respond with a challenge. */
240: if (type != SSH_SMSG_AUTH_RSA_CHALLENGE)
241: packet_disconnect("Protocol error during RSA authentication: %d", type);
242:
243: /* Get the challenge from the packet. */
244: challenge = BN_new();
245: packet_get_bignum(challenge, &clen);
246:
247: packet_integrity_check(plen, clen, type);
248:
249: debug("Received RSA challenge from server.");
250:
251: /*
1.38 markus 252: * If the key is not stored in external hardware, we have to
253: * load the private key. Try first with empty passphrase; if it
1.1 markus 254: * fails, ask for a passphrase.
255: */
1.38 markus 256: if (public->flags && KEY_FLAG_EXT)
257: private = public;
258: else
259: private = key_load_private_type(KEY_RSA1, authfile, "", NULL);
1.36 markus 260: if (private == NULL && !options.batch_mode) {
261: snprintf(buf, sizeof(buf),
262: "Enter passphrase for RSA key '%.100s': ", comment);
263: for (i = 0; i < options.number_of_password_prompts; i++) {
1.1 markus 264: passphrase = read_passphrase(buf, 0);
1.36 markus 265: if (strcmp(passphrase, "") != 0) {
266: private = key_load_private_type(KEY_RSA1,
267: authfile, passphrase, NULL);
268: quit = 0;
269: } else {
270: debug2("no passphrase given, try next key");
271: quit = 1;
272: }
1.1 markus 273: memset(passphrase, 0, strlen(passphrase));
274: xfree(passphrase);
1.36 markus 275: if (private != NULL || quit)
276: break;
277: debug2("bad passphrase given, try again...");
1.1 markus 278: }
279: }
280: /* We no longer need the comment. */
281: xfree(comment);
1.36 markus 282:
283: if (private == NULL) {
284: if (!options.batch_mode)
285: error("Bad passphrase.");
286:
287: /* Send a dummy response packet to avoid protocol error. */
288: packet_start(SSH_CMSG_AUTH_RSA_RESPONSE);
289: for (i = 0; i < 16; i++)
290: packet_put_char(0);
291: packet_send();
292: packet_write_wait();
293:
294: /* Expect the server to reject it... */
295: packet_read_expect(&plen, SSH_SMSG_FAILURE);
296: BN_clear_free(challenge);
297: return 0;
298: }
1.1 markus 299:
300: /* Compute and send a response to the challenge. */
301: respond_to_rsa_challenge(challenge, private->rsa);
302:
1.38 markus 303: /* Destroy the private key unless it in external hardware. */
304: if (!(private->flags & KEY_FLAG_EXT))
305: key_free(private);
1.1 markus 306:
307: /* We no longer need the challenge. */
308: BN_clear_free(challenge);
309:
310: /* Wait for response from the server. */
311: type = packet_read(&plen);
312: if (type == SSH_SMSG_SUCCESS) {
313: debug("RSA authentication accepted by server.");
314: return 1;
315: }
316: if (type != SSH_SMSG_FAILURE)
317: packet_disconnect("Protocol error waiting RSA auth response: %d", type);
318: debug("RSA authentication refused.");
319: return 0;
320: }
321:
322: /*
323: * Tries to authenticate the user using combined rhosts or /etc/hosts.equiv
324: * authentication and RSA host authentication.
325: */
1.35 itojun 326: static int
1.29 markus 327: try_rhosts_rsa_authentication(const char *local_user, Key * host_key)
1.1 markus 328: {
329: int type;
330: BIGNUM *challenge;
331: int plen, clen;
332:
333: debug("Trying rhosts or /etc/hosts.equiv with RSA host authentication.");
334:
335: /* Tell the server that we are willing to authenticate using this key. */
336: packet_start(SSH_CMSG_AUTH_RHOSTS_RSA);
1.33 markus 337: packet_put_cstring(local_user);
1.29 markus 338: packet_put_int(BN_num_bits(host_key->rsa->n));
339: packet_put_bignum(host_key->rsa->e);
340: packet_put_bignum(host_key->rsa->n);
1.1 markus 341: packet_send();
342: packet_write_wait();
343:
344: /* Wait for server's response. */
345: type = packet_read(&plen);
346:
347: /* The server responds with failure if it doesn't admit our
348: .rhosts authentication or doesn't know our host key. */
349: if (type == SSH_SMSG_FAILURE) {
350: debug("Server refused our rhosts authentication or host key.");
351: return 0;
352: }
353: /* Otherwise, the server should respond with a challenge. */
354: if (type != SSH_SMSG_AUTH_RSA_CHALLENGE)
355: packet_disconnect("Protocol error during RSA authentication: %d", type);
356:
357: /* Get the challenge from the packet. */
358: challenge = BN_new();
359: packet_get_bignum(challenge, &clen);
360:
361: packet_integrity_check(plen, clen, type);
362:
363: debug("Received RSA challenge for host key from server.");
364:
365: /* Compute a response to the challenge. */
1.29 markus 366: respond_to_rsa_challenge(challenge, host_key->rsa);
1.1 markus 367:
368: /* We no longer need the challenge. */
369: BN_clear_free(challenge);
370:
371: /* Wait for response from the server. */
372: type = packet_read(&plen);
373: if (type == SSH_SMSG_SUCCESS) {
374: debug("Rhosts or /etc/hosts.equiv with RSA host authentication accepted by server.");
375: return 1;
376: }
377: if (type != SSH_SMSG_FAILURE)
378: packet_disconnect("Protocol error waiting RSA auth response: %d", type);
379: debug("Rhosts or /etc/hosts.equiv with RSA host authentication refused.");
380: return 0;
381: }
382:
383: #ifdef KRB4
1.35 itojun 384: static int
1.37 dugsong 385: try_krb4_authentication(void)
1.1 markus 386: {
387: KTEXT_ST auth; /* Kerberos data */
388: char *reply;
389: char inst[INST_SZ];
390: char *realm;
391: CREDENTIALS cred;
392: int r, type, plen;
393: socklen_t slen;
394: Key_schedule schedule;
395: u_long checksum, cksum;
396: MSG_DAT msg_data;
397: struct sockaddr_in local, foreign;
398: struct stat st;
399:
400: /* Don't do anything if we don't have any tickets. */
401: if (stat(tkt_string(), &st) < 0)
402: return 0;
1.42 ! deraadt 403:
1.37 dugsong 404: strlcpy(inst, (char *)krb_get_phost(get_canonical_hostname(1)),
405: INST_SZ);
1.42 ! deraadt 406:
1.37 dugsong 407: realm = (char *)krb_realmofhost(get_canonical_hostname(1));
1.1 markus 408: if (!realm) {
1.37 dugsong 409: debug("Kerberos v4: no realm for %s", get_canonical_hostname(1));
1.1 markus 410: return 0;
411: }
412: /* This can really be anything. */
1.37 dugsong 413: checksum = (u_long)getpid();
1.42 ! deraadt 414:
1.1 markus 415: r = krb_mk_req(&auth, KRB4_SERVICE_NAME, inst, realm, checksum);
416: if (r != KSUCCESS) {
1.37 dugsong 417: debug("Kerberos v4 krb_mk_req failed: %s", krb_err_txt[r]);
1.1 markus 418: return 0;
419: }
420: /* Get session key to decrypt the server's reply with. */
421: r = krb_get_cred(KRB4_SERVICE_NAME, inst, realm, &cred);
422: if (r != KSUCCESS) {
423: debug("get_cred failed: %s", krb_err_txt[r]);
424: return 0;
425: }
426: des_key_sched((des_cblock *) cred.session, schedule);
1.42 ! deraadt 427:
1.1 markus 428: /* Send authentication info to server. */
429: packet_start(SSH_CMSG_AUTH_KERBEROS);
430: packet_put_string((char *) auth.dat, auth.length);
431: packet_send();
432: packet_write_wait();
1.42 ! deraadt 433:
1.1 markus 434: /* Zero the buffer. */
435: (void) memset(auth.dat, 0, MAX_KTXT_LEN);
1.42 ! deraadt 436:
1.1 markus 437: slen = sizeof(local);
438: memset(&local, 0, sizeof(local));
439: if (getsockname(packet_get_connection_in(),
1.37 dugsong 440: (struct sockaddr *)&local, &slen) < 0)
1.1 markus 441: debug("getsockname failed: %s", strerror(errno));
1.42 ! deraadt 442:
1.1 markus 443: slen = sizeof(foreign);
444: memset(&foreign, 0, sizeof(foreign));
445: if (getpeername(packet_get_connection_in(),
1.37 dugsong 446: (struct sockaddr *)&foreign, &slen) < 0) {
1.1 markus 447: debug("getpeername failed: %s", strerror(errno));
448: fatal_cleanup();
449: }
450: /* Get server reply. */
451: type = packet_read(&plen);
452: switch (type) {
453: case SSH_SMSG_FAILURE:
454: /* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
1.37 dugsong 455: debug("Kerberos v4 authentication failed.");
1.1 markus 456: return 0;
457: break;
1.42 ! deraadt 458:
1.1 markus 459: case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
460: /* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
1.37 dugsong 461: debug("Kerberos v4 authentication accepted.");
1.42 ! deraadt 462:
1.1 markus 463: /* Get server's response. */
1.13 markus 464: reply = packet_get_string((u_int *) &auth.length);
1.1 markus 465: memcpy(auth.dat, reply, auth.length);
466: xfree(reply);
1.42 ! deraadt 467:
1.1 markus 468: packet_integrity_check(plen, 4 + auth.length, type);
1.42 ! deraadt 469:
1.1 markus 470: /*
471: * If his response isn't properly encrypted with the session
472: * key, and the decrypted checksum fails to match, he's
473: * bogus. Bail out.
474: */
475: r = krb_rd_priv(auth.dat, auth.length, schedule, &cred.session,
1.37 dugsong 476: &foreign, &local, &msg_data);
1.1 markus 477: if (r != KSUCCESS) {
1.37 dugsong 478: debug("Kerberos v4 krb_rd_priv failed: %s",
479: krb_err_txt[r]);
480: packet_disconnect("Kerberos v4 challenge failed!");
1.1 markus 481: }
482: /* Fetch the (incremented) checksum that we supplied in the request. */
1.37 dugsong 483: memcpy((char *)&cksum, (char *)msg_data.app_data,
484: sizeof(cksum));
1.1 markus 485: cksum = ntohl(cksum);
1.42 ! deraadt 486:
1.1 markus 487: /* If it matches, we're golden. */
488: if (cksum == checksum + 1) {
1.37 dugsong 489: debug("Kerberos v4 challenge successful.");
1.1 markus 490: return 1;
491: } else
1.37 dugsong 492: packet_disconnect("Kerberos v4 challenge failed!");
1.1 markus 493: break;
1.42 ! deraadt 494:
1.1 markus 495: default:
1.37 dugsong 496: packet_disconnect("Protocol error on Kerberos v4 response: %d", type);
1.1 markus 497: }
498: return 0;
499: }
500:
501: #endif /* KRB4 */
502:
1.37 dugsong 503: #ifdef KRB5
504: static int
505: try_krb5_authentication(krb5_context *context, krb5_auth_context *auth_context)
506: {
507: krb5_error_code problem;
508: const char *tkfile;
509: struct stat buf;
510: krb5_ccache ccache = NULL;
511: const char *remotehost;
512: krb5_data ap;
513: int type, payload_len;
514: krb5_ap_rep_enc_part *reply = NULL;
515: int ret;
1.42 ! deraadt 516:
1.37 dugsong 517: memset(&ap, 0, sizeof(ap));
1.42 ! deraadt 518:
1.37 dugsong 519: problem = krb5_init_context(context);
520: if (problem) {
521: debug("Kerberos v5: krb5_init_context failed");
522: ret = 0;
523: goto out;
524: }
1.42 ! deraadt 525:
1.37 dugsong 526: tkfile = krb5_cc_default_name(*context);
527: if (strncmp(tkfile, "FILE:", 5) == 0)
528: tkfile += 5;
1.42 ! deraadt 529:
1.37 dugsong 530: if (stat(tkfile, &buf) == 0 && getuid() != buf.st_uid) {
531: debug("Kerberos v5: could not get default ccache (permission denied).");
532: ret = 0;
533: goto out;
534: }
1.42 ! deraadt 535:
1.37 dugsong 536: problem = krb5_cc_default(*context, &ccache);
537: if (problem) {
538: debug("Kerberos v5: krb5_cc_default failed: %s",
539: krb5_get_err_text(*context, problem));
540: ret = 0;
541: goto out;
542: }
1.42 ! deraadt 543:
1.37 dugsong 544: remotehost = get_canonical_hostname(1);
1.42 ! deraadt 545:
1.37 dugsong 546: problem = krb5_mk_req(*context, auth_context, AP_OPTS_MUTUAL_REQUIRED,
547: "host", remotehost, NULL, ccache, &ap);
548: if (problem) {
549: debug("Kerberos v5: krb5_mk_req failed: %s",
550: krb5_get_err_text(*context, problem));
551: ret = 0;
552: goto out;
553: }
1.42 ! deraadt 554:
1.37 dugsong 555: packet_start(SSH_CMSG_AUTH_KERBEROS);
556: packet_put_string((char *) ap.data, ap.length);
557: packet_send();
558: packet_write_wait();
1.42 ! deraadt 559:
1.37 dugsong 560: xfree(ap.data);
561: ap.length = 0;
1.42 ! deraadt 562:
1.37 dugsong 563: type = packet_read(&payload_len);
564: switch (type) {
1.42 ! deraadt 565: case SSH_SMSG_FAILURE:
! 566: /* Should really be SSH_SMSG_AUTH_KERBEROS_FAILURE */
! 567: debug("Kerberos v5 authentication failed.");
! 568: ret = 0;
! 569: break;
! 570:
1.37 dugsong 571: case SSH_SMSG_AUTH_KERBEROS_RESPONSE:
1.42 ! deraadt 572: /* SSH_SMSG_AUTH_KERBEROS_SUCCESS */
! 573: debug("Kerberos v5 authentication accepted.");
! 574:
! 575: /* Get server's response. */
! 576: ap.data = packet_get_string((unsigned int *) &ap.length);
! 577:
! 578: packet_integrity_check(payload_len, 4 + ap.length, type);
! 579: /* XXX je to dobre? */
! 580:
! 581: problem = krb5_rd_rep(*context, *auth_context, &ap, &reply);
! 582: if (problem) {
1.37 dugsong 583: ret = 0;
584: }
585: ret = 1;
586: break;
1.42 ! deraadt 587:
1.37 dugsong 588: default:
589: packet_disconnect("Protocol error on Kerberos v5 response: %d",
590: type);
591: ret = 0;
592: break;
1.42 ! deraadt 593:
1.37 dugsong 594: }
1.42 ! deraadt 595:
1.37 dugsong 596: out:
597: if (ccache != NULL)
598: krb5_cc_close(*context, ccache);
599: if (reply != NULL)
600: krb5_free_ap_rep_enc_part(*context, reply);
601: if (ap.length > 0)
602: krb5_data_free(&ap);
1.42 ! deraadt 603:
1.37 dugsong 604: return (ret);
605: }
606:
607: static void
608: send_krb5_tgt(krb5_context context, krb5_auth_context auth_context)
609: {
610: int fd, type, payload_len;
611: krb5_error_code problem;
612: krb5_data outbuf;
613: krb5_ccache ccache = NULL;
614: krb5_creds creds;
615: krb5_kdc_flags flags;
616: const char *remotehost;
1.42 ! deraadt 617:
1.37 dugsong 618: memset(&creds, 0, sizeof(creds));
619: memset(&outbuf, 0, sizeof(outbuf));
1.42 ! deraadt 620:
1.37 dugsong 621: fd = packet_get_connection_in();
1.42 ! deraadt 622:
1.37 dugsong 623: problem = krb5_auth_con_setaddrs_from_fd(context, auth_context, &fd);
624: if (problem)
625: goto out;
1.42 ! deraadt 626:
1.37 dugsong 627: problem = krb5_cc_default(context, &ccache);
628: if (problem)
629: goto out;
1.42 ! deraadt 630:
1.37 dugsong 631: problem = krb5_cc_get_principal(context, ccache, &creds.client);
632: if (problem)
633: goto out;
1.42 ! deraadt 634:
1.37 dugsong 635: problem = krb5_build_principal(context, &creds.server,
636: strlen(creds.client->realm), creds.client->realm,
637: "krbtgt", creds.client->realm, NULL);
638: if (problem)
639: goto out;
1.42 ! deraadt 640:
1.37 dugsong 641: creds.times.endtime = 0;
1.42 ! deraadt 642:
1.37 dugsong 643: flags.i = 0;
644: flags.b.forwarded = 1;
645: flags.b.forwardable = krb5_config_get_bool(context, NULL,
646: "libdefaults", "forwardable", NULL);
1.42 ! deraadt 647:
1.37 dugsong 648: remotehost = get_canonical_hostname(1);
1.42 ! deraadt 649:
1.37 dugsong 650: problem = krb5_get_forwarded_creds(context, auth_context,
651: ccache, flags.i, remotehost, &creds, &outbuf);
652: if (problem)
653: goto out;
1.42 ! deraadt 654:
1.37 dugsong 655: packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
656: packet_put_string((char *)outbuf.data, outbuf.length);
657: packet_send();
658: packet_write_wait();
1.42 ! deraadt 659:
1.37 dugsong 660: type = packet_read(&payload_len);
1.42 ! deraadt 661:
1.37 dugsong 662: if (type == SSH_SMSG_SUCCESS) {
663: char *pname;
1.42 ! deraadt 664:
1.37 dugsong 665: krb5_unparse_name(context, creds.client, &pname);
666: debug("Kerberos v5 TGT forwarded (%s).", pname);
667: xfree(pname);
668: } else
669: debug("Kerberos v5 TGT forwarding failed.");
1.42 ! deraadt 670:
1.37 dugsong 671: return;
1.42 ! deraadt 672:
1.37 dugsong 673: out:
674: if (problem)
675: debug("Kerberos v5 TGT forwarding failed: %s",
676: krb5_get_err_text(context, problem));
677: if (creds.client)
678: krb5_free_principal(context, creds.client);
679: if (creds.server)
680: krb5_free_principal(context, creds.server);
681: if (ccache)
682: krb5_cc_close(context, ccache);
683: if (outbuf.data)
684: xfree(outbuf.data);
685: }
686: #endif /* KRB5 */
687:
1.1 markus 688: #ifdef AFS
1.37 dugsong 689: static void
690: send_krb4_tgt(void)
1.1 markus 691: {
692: CREDENTIALS *creds;
693: struct stat st;
1.37 dugsong 694: char buffer[4096], pname[ANAME_SZ], pinst[INST_SZ], prealm[REALM_SZ];
695: int problem, type, len;
1.42 ! deraadt 696:
1.1 markus 697: /* Don't do anything if we don't have any tickets. */
698: if (stat(tkt_string(), &st) < 0)
1.37 dugsong 699: return;
1.42 ! deraadt 700:
1.1 markus 701: creds = xmalloc(sizeof(*creds));
1.42 ! deraadt 702:
1.37 dugsong 703: problem = krb_get_tf_fullname(TKT_FILE, pname, pinst, prealm);
704: if (problem)
705: goto out;
1.42 ! deraadt 706:
1.37 dugsong 707: problem = krb_get_cred("krbtgt", prealm, prealm, creds);
708: if (problem)
709: goto out;
1.42 ! deraadt 710:
1.1 markus 711: if (time(0) > krb_life_to_time(creds->issue_date, creds->lifetime)) {
1.37 dugsong 712: problem = RD_AP_EXP;
713: goto out;
1.1 markus 714: }
1.37 dugsong 715: creds_to_radix(creds, (u_char *)buffer, sizeof(buffer));
1.42 ! deraadt 716:
1.1 markus 717: packet_start(SSH_CMSG_HAVE_KERBEROS_TGT);
1.33 markus 718: packet_put_cstring(buffer);
1.1 markus 719: packet_send();
720: packet_write_wait();
1.42 ! deraadt 721:
1.37 dugsong 722: type = packet_read(&len);
1.42 ! deraadt 723:
1.37 dugsong 724: if (type == SSH_SMSG_SUCCESS)
725: debug("Kerberos v4 TGT forwarded (%s%s%s@%s).",
726: creds->pname, creds->pinst[0] ? "." : "",
727: creds->pinst, creds->realm);
728: else
729: debug("Kerberos v4 TGT rejected.");
1.42 ! deraadt 730:
1.37 dugsong 731: xfree(creds);
732: return;
1.42 ! deraadt 733:
1.37 dugsong 734: out:
735: debug("Kerberos v4 TGT passing failed: %s", krb_err_txt[problem]);
736: xfree(creds);
1.1 markus 737: }
738:
1.35 itojun 739: static void
1.1 markus 740: send_afs_tokens(void)
741: {
742: CREDENTIALS creds;
743: struct ViceIoctl parms;
744: struct ClearToken ct;
1.37 dugsong 745: int i, type, len;
1.1 markus 746: char buf[2048], *p, *server_cell;
747: char buffer[8192];
1.42 ! deraadt 748:
1.1 markus 749: /* Move over ktc_GetToken, here's something leaner. */
750: for (i = 0; i < 100; i++) { /* just in case */
751: parms.in = (char *) &i;
752: parms.in_size = sizeof(i);
753: parms.out = buf;
754: parms.out_size = sizeof(buf);
755: if (k_pioctl(0, VIOCGETTOK, &parms, 0) != 0)
756: break;
757: p = buf;
1.42 ! deraadt 758:
1.1 markus 759: /* Get secret token. */
1.13 markus 760: memcpy(&creds.ticket_st.length, p, sizeof(u_int));
1.1 markus 761: if (creds.ticket_st.length > MAX_KTXT_LEN)
762: break;
1.13 markus 763: p += sizeof(u_int);
1.1 markus 764: memcpy(creds.ticket_st.dat, p, creds.ticket_st.length);
765: p += creds.ticket_st.length;
1.42 ! deraadt 766:
1.1 markus 767: /* Get clear token. */
768: memcpy(&len, p, sizeof(len));
769: if (len != sizeof(struct ClearToken))
770: break;
771: p += sizeof(len);
772: memcpy(&ct, p, len);
773: p += len;
774: p += sizeof(len); /* primary flag */
775: server_cell = p;
1.42 ! deraadt 776:
1.1 markus 777: /* Flesh out our credentials. */
1.37 dugsong 778: strlcpy(creds.service, "afs", sizeof(creds.service));
1.1 markus 779: creds.instance[0] = '\0';
780: strlcpy(creds.realm, server_cell, REALM_SZ);
781: memcpy(creds.session, ct.HandShakeKey, DES_KEY_SZ);
782: creds.issue_date = ct.BeginTimestamp;
1.37 dugsong 783: creds.lifetime = krb_time_to_life(creds.issue_date,
784: ct.EndTimestamp);
1.1 markus 785: creds.kvno = ct.AuthHandle;
786: snprintf(creds.pname, sizeof(creds.pname), "AFS ID %d", ct.ViceId);
787: creds.pinst[0] = '\0';
1.42 ! deraadt 788:
1.1 markus 789: /* Encode token, ship it off. */
1.37 dugsong 790: if (creds_to_radix(&creds, (u_char *)buffer,
791: sizeof(buffer)) <= 0)
1.1 markus 792: break;
793: packet_start(SSH_CMSG_HAVE_AFS_TOKEN);
1.33 markus 794: packet_put_cstring(buffer);
1.1 markus 795: packet_send();
796: packet_write_wait();
797:
798: /* Roger, Roger. Clearance, Clarence. What's your vector,
799: Victor? */
1.37 dugsong 800: type = packet_read(&len);
1.42 ! deraadt 801:
1.1 markus 802: if (type == SSH_SMSG_FAILURE)
803: debug("AFS token for cell %s rejected.", server_cell);
804: else if (type != SSH_SMSG_SUCCESS)
805: packet_disconnect("Protocol error on AFS token response: %d", type);
806: }
807: }
808:
809: #endif /* AFS */
810:
811: /*
812: * Tries to authenticate with any string-based challenge/response system.
813: * Note that the client code is not tied to s/key or TIS.
814: */
1.35 itojun 815: static int
1.32 markus 816: try_challenge_response_authentication(void)
1.1 markus 817: {
818: int type, i;
819: int payload_len;
1.13 markus 820: u_int clen;
1.12 markus 821: char prompt[1024];
1.1 markus 822: char *challenge, *response;
1.40 markus 823:
824: debug("Doing challenge response authentication.");
825:
1.12 markus 826: for (i = 0; i < options.number_of_password_prompts; i++) {
827: /* request a challenge */
828: packet_start(SSH_CMSG_AUTH_TIS);
829: packet_send();
830: packet_write_wait();
1.1 markus 831:
1.12 markus 832: type = packet_read(&payload_len);
833: if (type != SSH_SMSG_FAILURE &&
834: type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
835: packet_disconnect("Protocol error: got %d in response "
1.20 markus 836: "to SSH_CMSG_AUTH_TIS", type);
1.12 markus 837: }
838: if (type != SSH_SMSG_AUTH_TIS_CHALLENGE) {
1.20 markus 839: debug("No challenge.");
1.12 markus 840: return 0;
841: }
842: challenge = packet_get_string(&clen);
843: packet_integrity_check(payload_len, (4 + clen), type);
1.16 markus 844: snprintf(prompt, sizeof prompt, "%s%s", challenge,
1.42 ! deraadt 845: strchr(challenge, '\n') ? "" : "\nResponse: ");
1.12 markus 846: xfree(challenge);
1.1 markus 847: if (i != 0)
848: error("Permission denied, please try again.");
1.12 markus 849: if (options.cipher == SSH_CIPHER_NONE)
850: log("WARNING: Encryption is disabled! "
851: "Reponse will be transmitted in clear text.");
852: response = read_passphrase(prompt, 0);
853: if (strcmp(response, "") == 0) {
854: xfree(response);
855: break;
856: }
1.1 markus 857: packet_start(SSH_CMSG_AUTH_TIS_RESPONSE);
1.27 markus 858: ssh_put_password(response);
1.1 markus 859: memset(response, 0, strlen(response));
860: xfree(response);
861: packet_send();
862: packet_write_wait();
863: type = packet_read(&payload_len);
864: if (type == SSH_SMSG_SUCCESS)
865: return 1;
866: if (type != SSH_SMSG_FAILURE)
867: packet_disconnect("Protocol error: got %d in response "
1.20 markus 868: "to SSH_CMSG_AUTH_TIS_RESPONSE", type);
1.1 markus 869: }
870: /* failure */
871: return 0;
872: }
873:
874: /*
875: * Tries to authenticate with plain passwd authentication.
876: */
1.35 itojun 877: static int
1.1 markus 878: try_password_authentication(char *prompt)
879: {
880: int type, i, payload_len;
881: char *password;
882:
883: debug("Doing password authentication.");
884: if (options.cipher == SSH_CIPHER_NONE)
885: log("WARNING: Encryption is disabled! Password will be transmitted in clear text.");
886: for (i = 0; i < options.number_of_password_prompts; i++) {
887: if (i != 0)
888: error("Permission denied, please try again.");
889: password = read_passphrase(prompt, 0);
890: packet_start(SSH_CMSG_AUTH_PASSWORD);
1.27 markus 891: ssh_put_password(password);
1.1 markus 892: memset(password, 0, strlen(password));
893: xfree(password);
894: packet_send();
895: packet_write_wait();
896:
897: type = packet_read(&payload_len);
898: if (type == SSH_SMSG_SUCCESS)
899: return 1;
900: if (type != SSH_SMSG_FAILURE)
901: packet_disconnect("Protocol error: got %d in response to passwd auth", type);
902: }
903: /* failure */
904: return 0;
905: }
906:
907: /*
908: * SSH1 key exchange
909: */
910: void
911: ssh_kex(char *host, struct sockaddr *hostaddr)
912: {
913: int i;
914: BIGNUM *key;
915: RSA *host_key;
916: RSA *public_key;
917: Key k;
918: int bits, rbits;
919: int ssh_cipher_default = SSH_CIPHER_3DES;
1.13 markus 920: u_char session_key[SSH_SESSION_KEY_LENGTH];
921: u_char cookie[8];
922: u_int supported_ciphers;
923: u_int server_flags, client_flags;
1.1 markus 924: int payload_len, clen, sum_len = 0;
925: u_int32_t rand = 0;
926:
927: debug("Waiting for server public key.");
928:
929: /* Wait for a public key packet from the server. */
930: packet_read_expect(&payload_len, SSH_SMSG_PUBLIC_KEY);
931:
932: /* Get cookie from the packet. */
933: for (i = 0; i < 8; i++)
934: cookie[i] = packet_get_char();
935:
936: /* Get the public key. */
937: public_key = RSA_new();
938: bits = packet_get_int();/* bits */
939: public_key->e = BN_new();
940: packet_get_bignum(public_key->e, &clen);
941: sum_len += clen;
942: public_key->n = BN_new();
943: packet_get_bignum(public_key->n, &clen);
944: sum_len += clen;
945:
946: rbits = BN_num_bits(public_key->n);
947: if (bits != rbits) {
948: log("Warning: Server lies about size of server public key: "
949: "actual size is %d bits vs. announced %d.", rbits, bits);
950: log("Warning: This may be due to an old implementation of ssh.");
951: }
952: /* Get the host key. */
953: host_key = RSA_new();
954: bits = packet_get_int();/* bits */
955: host_key->e = BN_new();
956: packet_get_bignum(host_key->e, &clen);
957: sum_len += clen;
958: host_key->n = BN_new();
959: packet_get_bignum(host_key->n, &clen);
960: sum_len += clen;
961:
962: rbits = BN_num_bits(host_key->n);
963: if (bits != rbits) {
964: log("Warning: Server lies about size of server host key: "
965: "actual size is %d bits vs. announced %d.", rbits, bits);
966: log("Warning: This may be due to an old implementation of ssh.");
967: }
968:
969: /* Get protocol flags. */
970: server_flags = packet_get_int();
971: packet_set_protocol_flags(server_flags);
972:
973: supported_ciphers = packet_get_int();
974: supported_authentications = packet_get_int();
975:
976: debug("Received server public key (%d bits) and host key (%d bits).",
1.42 ! deraadt 977: BN_num_bits(public_key->n), BN_num_bits(host_key->n));
1.1 markus 978:
979: packet_integrity_check(payload_len,
1.42 ! deraadt 980: 8 + 4 + sum_len + 0 + 4 + 0 + 0 + 4 + 4 + 4,
! 981: SSH_SMSG_PUBLIC_KEY);
1.9 markus 982: k.type = KEY_RSA1;
1.1 markus 983: k.rsa = host_key;
1.34 markus 984: if (verify_host_key(host, hostaddr, &k) == -1)
1.41 markus 985: fatal("Host key verification failed.");
1.1 markus 986:
987: client_flags = SSH_PROTOFLAG_SCREEN_NUMBER | SSH_PROTOFLAG_HOST_IN_FWD_OPEN;
988:
989: compute_session_id(session_id, cookie, host_key->n, public_key->n);
990:
991: /* Generate a session key. */
992: arc4random_stir();
993:
994: /*
995: * Generate an encryption key for the session. The key is a 256 bit
996: * random number, interpreted as a 32-byte key, with the least
997: * significant 8 bits being the first byte of the key.
998: */
999: for (i = 0; i < 32; i++) {
1000: if (i % 4 == 0)
1001: rand = arc4random();
1002: session_key[i] = rand & 0xff;
1003: rand >>= 8;
1004: }
1005:
1006: /*
1007: * According to the protocol spec, the first byte of the session key
1008: * is the highest byte of the integer. The session key is xored with
1009: * the first 16 bytes of the session id.
1010: */
1011: key = BN_new();
1012: BN_set_word(key, 0);
1013: for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
1014: BN_lshift(key, key, 8);
1015: if (i < 16)
1016: BN_add_word(key, session_key[i] ^ session_id[i]);
1017: else
1018: BN_add_word(key, session_key[i]);
1019: }
1020:
1021: /*
1022: * Encrypt the integer using the public key and host key of the
1023: * server (key with smaller modulus first).
1024: */
1025: if (BN_cmp(public_key->n, host_key->n) < 0) {
1026: /* Public key has smaller modulus. */
1027: if (BN_num_bits(host_key->n) <
1028: BN_num_bits(public_key->n) + SSH_KEY_BITS_RESERVED) {
1029: fatal("respond_to_rsa_challenge: host_key %d < public_key %d + "
1.42 ! deraadt 1030: "SSH_KEY_BITS_RESERVED %d",
! 1031: BN_num_bits(host_key->n),
! 1032: BN_num_bits(public_key->n),
! 1033: SSH_KEY_BITS_RESERVED);
1.1 markus 1034: }
1035: rsa_public_encrypt(key, key, public_key);
1036: rsa_public_encrypt(key, key, host_key);
1037: } else {
1038: /* Host key has smaller modulus (or they are equal). */
1039: if (BN_num_bits(public_key->n) <
1040: BN_num_bits(host_key->n) + SSH_KEY_BITS_RESERVED) {
1041: fatal("respond_to_rsa_challenge: public_key %d < host_key %d + "
1.42 ! deraadt 1042: "SSH_KEY_BITS_RESERVED %d",
! 1043: BN_num_bits(public_key->n),
! 1044: BN_num_bits(host_key->n),
! 1045: SSH_KEY_BITS_RESERVED);
1.1 markus 1046: }
1047: rsa_public_encrypt(key, key, host_key);
1048: rsa_public_encrypt(key, key, public_key);
1049: }
1050:
1051: /* Destroy the public keys since we no longer need them. */
1052: RSA_free(public_key);
1053: RSA_free(host_key);
1054:
1.11 markus 1055: if (options.cipher == SSH_CIPHER_NOT_SET) {
1056: if (cipher_mask_ssh1(1) & supported_ciphers & (1 << ssh_cipher_default))
1057: options.cipher = ssh_cipher_default;
1058: } else if (options.cipher == SSH_CIPHER_ILLEGAL ||
1.10 markus 1059: !(cipher_mask_ssh1(1) & (1 << options.cipher))) {
1.3 markus 1060: log("No valid SSH1 cipher, using %.100s instead.",
1.7 markus 1061: cipher_name(ssh_cipher_default));
1062: options.cipher = ssh_cipher_default;
1.1 markus 1063: }
1064: /* Check that the selected cipher is supported. */
1065: if (!(supported_ciphers & (1 << options.cipher)))
1066: fatal("Selected cipher type %.100s not supported by server.",
1.42 ! deraadt 1067: cipher_name(options.cipher));
1.1 markus 1068:
1069: debug("Encryption type: %.100s", cipher_name(options.cipher));
1070:
1071: /* Send the encrypted session key to the server. */
1072: packet_start(SSH_CMSG_SESSION_KEY);
1073: packet_put_char(options.cipher);
1074:
1075: /* Send the cookie back to the server. */
1076: for (i = 0; i < 8; i++)
1077: packet_put_char(cookie[i]);
1078:
1079: /* Send and destroy the encrypted encryption key integer. */
1080: packet_put_bignum(key);
1081: BN_clear_free(key);
1082:
1083: /* Send protocol flags. */
1084: packet_put_int(client_flags);
1085:
1086: /* Send the packet now. */
1087: packet_send();
1088: packet_write_wait();
1089:
1090: debug("Sent encrypted session key.");
1091:
1092: /* Set the encryption key. */
1093: packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, options.cipher);
1094:
1095: /* We will no longer need the session key here. Destroy any extra copies. */
1096: memset(session_key, 0, sizeof(session_key));
1097:
1098: /*
1099: * Expect a success message from the server. Note that this message
1100: * will be received in encrypted form.
1101: */
1102: packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
1103:
1104: debug("Received encrypted confirmation.");
1105: }
1106:
1107: /*
1108: * Authenticate user
1109: */
1110: void
1.30 markus 1111: ssh_userauth1(const char *local_user, const char *server_user, char *host,
1112: Key **keys, int nkeys)
1.1 markus 1113: {
1.37 dugsong 1114: #ifdef KRB5
1115: krb5_context context = NULL;
1116: krb5_auth_context auth_context = NULL;
1117: #endif
1.1 markus 1118: int i, type;
1119: int payload_len;
1.42 ! deraadt 1120:
1.1 markus 1121: if (supported_authentications == 0)
1.30 markus 1122: fatal("ssh_userauth1: server supports no auth methods");
1.1 markus 1123:
1124: /* Send the name of the user to log in as on the server. */
1125: packet_start(SSH_CMSG_USER);
1.33 markus 1126: packet_put_cstring(server_user);
1.1 markus 1127: packet_send();
1128: packet_write_wait();
1129:
1130: /*
1131: * The server should respond with success if no authentication is
1132: * needed (the user has no password). Otherwise the server responds
1133: * with failure.
1134: */
1135: type = packet_read(&payload_len);
1136:
1137: /* check whether the connection was accepted without authentication. */
1138: if (type == SSH_SMSG_SUCCESS)
1.37 dugsong 1139: goto success;
1.1 markus 1140: if (type != SSH_SMSG_FAILURE)
1.37 dugsong 1141: packet_disconnect("Protocol error: got %d in response to SSH_CMSG_USER", type);
1.42 ! deraadt 1142:
1.37 dugsong 1143: #ifdef KRB5
1144: if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) &&
1.42 ! deraadt 1145: options.kerberos_authentication) {
1.37 dugsong 1146: debug("Trying Kerberos v5 authentication.");
1.42 ! deraadt 1147:
1.37 dugsong 1148: if (try_krb5_authentication(&context, &auth_context)) {
1149: type = packet_read(&payload_len);
1150: if (type == SSH_SMSG_SUCCESS)
1151: goto success;
1152: if (type != SSH_SMSG_FAILURE)
1153: packet_disconnect("Protocol error: got %d in response to Kerberos v5 auth", type);
1154: }
1.1 markus 1155: }
1.37 dugsong 1156: #endif /* KRB5 */
1.42 ! deraadt 1157:
1.1 markus 1158: #ifdef KRB4
1159: if ((supported_authentications & (1 << SSH_AUTH_KERBEROS)) &&
1160: options.kerberos_authentication) {
1.37 dugsong 1161: debug("Trying Kerberos v4 authentication.");
1.42 ! deraadt 1162:
1.37 dugsong 1163: if (try_krb4_authentication()) {
1.1 markus 1164: type = packet_read(&payload_len);
1165: if (type == SSH_SMSG_SUCCESS)
1.37 dugsong 1166: goto success;
1.1 markus 1167: if (type != SSH_SMSG_FAILURE)
1.37 dugsong 1168: packet_disconnect("Protocol error: got %d in response to Kerberos v4 auth", type);
1.1 markus 1169: }
1170: }
1171: #endif /* KRB4 */
1.42 ! deraadt 1172:
1.1 markus 1173: /*
1174: * Use rhosts authentication if running in privileged socket and we
1175: * do not wish to remain anonymous.
1176: */
1177: if ((supported_authentications & (1 << SSH_AUTH_RHOSTS)) &&
1178: options.rhosts_authentication) {
1179: debug("Trying rhosts authentication.");
1180: packet_start(SSH_CMSG_AUTH_RHOSTS);
1.33 markus 1181: packet_put_cstring(local_user);
1.1 markus 1182: packet_send();
1183: packet_write_wait();
1184:
1185: /* The server should respond with success or failure. */
1186: type = packet_read(&payload_len);
1187: if (type == SSH_SMSG_SUCCESS)
1.37 dugsong 1188: goto success;
1.1 markus 1189: if (type != SSH_SMSG_FAILURE)
1190: packet_disconnect("Protocol error: got %d in response to rhosts auth",
1191: type);
1192: }
1193: /*
1194: * Try .rhosts or /etc/hosts.equiv authentication with RSA host
1195: * authentication.
1196: */
1197: if ((supported_authentications & (1 << SSH_AUTH_RHOSTS_RSA)) &&
1.30 markus 1198: options.rhosts_rsa_authentication) {
1199: for (i = 0; i < nkeys; i++) {
1.31 markus 1200: if (keys[i] != NULL && keys[i]->type == KEY_RSA1 &&
1.30 markus 1201: try_rhosts_rsa_authentication(local_user, keys[i]))
1.37 dugsong 1202: goto success;
1.30 markus 1203: }
1.1 markus 1204: }
1205: /* Try RSA authentication if the server supports it. */
1206: if ((supported_authentications & (1 << SSH_AUTH_RSA)) &&
1207: options.rsa_authentication) {
1208: /*
1209: * Try RSA authentication using the authentication agent. The
1210: * agent is tried first because no passphrase is needed for
1211: * it, whereas identity files may require passphrases.
1212: */
1213: if (try_agent_authentication())
1.37 dugsong 1214: goto success;
1.1 markus 1215:
1216: /* Try RSA authentication for each identity. */
1217: for (i = 0; i < options.num_identity_files; i++)
1.28 markus 1218: if (options.identity_keys[i] != NULL &&
1219: options.identity_keys[i]->type == KEY_RSA1 &&
1.38 markus 1220: try_rsa_authentication(i))
1.37 dugsong 1221: goto success;
1.1 markus 1222: }
1.20 markus 1223: /* Try challenge response authentication if the server supports it. */
1.1 markus 1224: if ((supported_authentications & (1 << SSH_AUTH_TIS)) &&
1.32 markus 1225: options.challenge_response_authentication && !options.batch_mode) {
1226: if (try_challenge_response_authentication())
1.37 dugsong 1227: goto success;
1.1 markus 1228: }
1229: /* Try password authentication if the server supports it. */
1230: if ((supported_authentications & (1 << SSH_AUTH_PASSWORD)) &&
1231: options.password_authentication && !options.batch_mode) {
1232: char prompt[80];
1233:
1.23 itojun 1234: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.1 markus 1235: server_user, host);
1236: if (try_password_authentication(prompt))
1.37 dugsong 1237: goto success;
1.1 markus 1238: }
1239: /* All authentication methods have failed. Exit with an error message. */
1240: fatal("Permission denied.");
1241: /* NOTREACHED */
1.37 dugsong 1242:
1243: success:
1244: #ifdef KRB5
1245: /* Try Kerberos v5 TGT passing. */
1246: if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) &&
1247: options.kerberos_tgt_passing && context && auth_context) {
1248: if (options.cipher == SSH_CIPHER_NONE)
1249: log("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
1250: send_krb5_tgt(context, auth_context);
1251: }
1252: if (auth_context)
1253: krb5_auth_con_free(context, auth_context);
1254: if (context)
1255: krb5_free_context(context);
1256: #endif
1.42 ! deraadt 1257:
1.37 dugsong 1258: #ifdef AFS
1259: /* Try Kerberos v4 TGT passing if the server supports it. */
1260: if ((supported_authentications & (1 << SSH_PASS_KERBEROS_TGT)) &&
1261: options.kerberos_tgt_passing) {
1262: if (options.cipher == SSH_CIPHER_NONE)
1263: log("WARNING: Encryption is disabled! Ticket will be transmitted in the clear!");
1264: send_krb4_tgt();
1265: }
1266: /* Try AFS token passing if the server supports it. */
1267: if ((supported_authentications & (1 << SSH_PASS_AFS_TOKEN)) &&
1268: options.afs_token_passing && k_hasafs()) {
1269: if (options.cipher == SSH_CIPHER_NONE)
1270: log("WARNING: Encryption is disabled! Token will be transmitted in the clear!");
1271: send_afs_tokens();
1272: }
1273: #endif /* AFS */
1.39 stevesk 1274:
1275: return; /* need statement after label */
1.1 markus 1276: }
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