Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.143
1.1 markus 1: /*
2: * Copyright (c) 2000 Markus Friedl. All rights reserved.
3: *
4: * Redistribution and use in source and binary forms, with or without
5: * modification, are permitted provided that the following conditions
6: * are met:
7: * 1. Redistributions of source code must retain the above copyright
8: * notice, this list of conditions and the following disclaimer.
9: * 2. Redistributions in binary form must reproduce the above copyright
10: * notice, this list of conditions and the following disclaimer in the
11: * documentation and/or other materials provided with the distribution.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: */
24:
25: #include "includes.h"
1.143 ! stevesk 26: RCSID("$OpenBSD: sshconnect2.c,v 1.142 2005/08/30 22:08:05 djm Exp $");
1.1 markus 27:
28: #include "ssh.h"
1.37 markus 29: #include "ssh2.h"
1.1 markus 30: #include "xmalloc.h"
31: #include "buffer.h"
32: #include "packet.h"
33: #include "compat.h"
34: #include "bufaux.h"
1.37 markus 35: #include "cipher.h"
1.1 markus 36: #include "kex.h"
37: #include "myproposal.h"
38: #include "sshconnect.h"
39: #include "authfile.h"
1.57 provos 40: #include "dh.h"
1.17 markus 41: #include "authfd.h"
1.37 markus 42: #include "log.h"
43: #include "readconf.h"
1.137 djm 44: #include "misc.h"
1.53 markus 45: #include "match.h"
1.61 markus 46: #include "dispatch.h"
1.68 markus 47: #include "canohost.h"
1.100 markus 48: #include "msg.h"
49: #include "pathnames.h"
1.22 provos 50:
1.121 markus 51: #ifdef GSSAPI
52: #include "ssh-gss.h"
53: #endif
54:
1.1 markus 55: /* import */
56: extern char *client_version_string;
57: extern char *server_version_string;
58: extern Options options;
59:
60: /*
61: * SSH2 key exchange
62: */
63:
1.32 markus 64: u_char *session_id2 = NULL;
1.120 markus 65: u_int session_id2_len = 0;
1.1 markus 66:
1.61 markus 67: char *xxx_host;
68: struct sockaddr *xxx_hostaddr;
69:
1.63 markus 70: Kex *xxx_kex = NULL;
71:
1.76 itojun 72: static int
1.75 markus 73: verify_host_key_callback(Key *hostkey)
1.61 markus 74: {
1.75 markus 75: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 76: fatal("Host key verification failed.");
1.61 markus 77: return 0;
78: }
79:
1.1 markus 80: void
1.22 provos 81: ssh_kex2(char *host, struct sockaddr *hostaddr)
82: {
83: Kex *kex;
1.61 markus 84:
85: xxx_host = host;
86: xxx_hostaddr = hostaddr;
1.22 provos 87:
1.29 markus 88: if (options.ciphers == (char *)-1) {
1.116 itojun 89: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 90: options.ciphers = NULL;
1.24 markus 91: }
1.22 provos 92: if (options.ciphers != NULL) {
93: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
94: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
95: }
1.60 stevesk 96: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
97: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
98: myproposal[PROPOSAL_ENC_ALGS_STOC] =
99: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 100: if (options.compression) {
1.47 markus 101: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 102: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 103: } else {
1.47 markus 104: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 105: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 106: }
107: if (options.macs != NULL) {
108: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
109: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 110: }
1.70 markus 111: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 112: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 113: options.hostkeyalgorithms;
1.115 markus 114:
115: if (options.rekey_limit)
116: packet_set_rekey_limit(options.rekey_limit);
1.22 provos 117:
1.65 markus 118: /* start key exchange */
1.64 markus 119: kex = kex_setup(myproposal);
1.111 markus 120: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 121: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 122: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.61 markus 123: kex->client_version_string=client_version_string;
124: kex->server_version_string=server_version_string;
1.75 markus 125: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 126:
127: xxx_kex = kex;
1.22 provos 128:
1.66 markus 129: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 130:
131: session_id2 = kex->session_id;
132: session_id2_len = kex->session_id_len;
1.22 provos 133:
134: #ifdef DEBUG_KEXDH
135: /* send 1st encrypted/maced/compressed message */
136: packet_start(SSH2_MSG_IGNORE);
137: packet_put_cstring("markus");
138: packet_send();
139: packet_write_wait();
140: #endif
1.1 markus 141: }
1.11 markus 142:
1.1 markus 143: /*
144: * Authenticate user
145: */
1.20 markus 146:
147: typedef struct Authctxt Authctxt;
148: typedef struct Authmethod Authmethod;
1.117 markus 149: typedef struct identity Identity;
150: typedef struct idlist Idlist;
1.20 markus 151:
1.117 markus 152: struct identity {
153: TAILQ_ENTRY(identity) next;
154: AuthenticationConnection *ac; /* set if agent supports key */
155: Key *key; /* public/private key */
156: char *filename; /* comment for agent-only keys */
157: int tried;
158: int isprivate; /* key points to the private key */
159: };
160: TAILQ_HEAD(idlist, identity);
1.20 markus 161:
162: struct Authctxt {
163: const char *server_user;
1.68 markus 164: const char *local_user;
1.20 markus 165: const char *host;
166: const char *service;
1.23 markus 167: Authmethod *method;
1.20 markus 168: int success;
1.51 markus 169: char *authlist;
1.68 markus 170: /* pubkey */
1.117 markus 171: Idlist keys;
1.68 markus 172: AuthenticationConnection *agent;
173: /* hostbased */
1.100 markus 174: Sensitive *sensitive;
1.82 markus 175: /* kbd-interactive */
176: int info_req_seen;
1.121 markus 177: /* generic */
178: void *methoddata;
1.20 markus 179: };
180: struct Authmethod {
181: char *name; /* string to compare against server's list */
182: int (*userauth)(Authctxt *authctxt);
183: int *enabled; /* flag in option struct that enables method */
184: int *batch_flag; /* flag in option struct that disables method */
185: };
186:
1.92 markus 187: void input_userauth_success(int, u_int32_t, void *);
188: void input_userauth_failure(int, u_int32_t, void *);
189: void input_userauth_banner(int, u_int32_t, void *);
190: void input_userauth_error(int, u_int32_t, void *);
191: void input_userauth_info_req(int, u_int32_t, void *);
192: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 193: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 194:
195: int userauth_none(Authctxt *);
196: int userauth_pubkey(Authctxt *);
197: int userauth_passwd(Authctxt *);
198: int userauth_kbdint(Authctxt *);
199: int userauth_hostbased(Authctxt *);
1.118 markus 200: int userauth_kerberos(Authctxt *);
1.20 markus 201:
1.121 markus 202: #ifdef GSSAPI
203: int userauth_gssapi(Authctxt *authctxt);
204: void input_gssapi_response(int type, u_int32_t, void *);
205: void input_gssapi_token(int type, u_int32_t, void *);
206: void input_gssapi_hash(int type, u_int32_t, void *);
207: void input_gssapi_error(int, u_int32_t, void *);
208: void input_gssapi_errtok(int, u_int32_t, void *);
209: #endif
210:
1.86 itojun 211: void userauth(Authctxt *, char *);
1.51 markus 212:
1.117 markus 213: static int sign_and_send_pubkey(Authctxt *, Identity *);
214: static void pubkey_prepare(Authctxt *);
215: static void pubkey_cleanup(Authctxt *);
216: static Key *load_identity_file(char *);
1.76 itojun 217:
218: static Authmethod *authmethod_get(char *authlist);
219: static Authmethod *authmethod_lookup(const char *name);
220: static char *authmethods_get(void);
1.20 markus 221:
222: Authmethod authmethods[] = {
1.121 markus 223: #ifdef GSSAPI
1.132 markus 224: {"gssapi-with-mic",
1.121 markus 225: userauth_gssapi,
226: &options.gss_authentication,
227: NULL},
228: #endif
1.81 markus 229: {"hostbased",
230: userauth_hostbased,
231: &options.hostbased_authentication,
232: NULL},
1.20 markus 233: {"publickey",
234: userauth_pubkey,
1.28 markus 235: &options.pubkey_authentication,
1.20 markus 236: NULL},
1.81 markus 237: {"keyboard-interactive",
238: userauth_kbdint,
239: &options.kbd_interactive_authentication,
240: &options.batch_mode},
1.20 markus 241: {"password",
242: userauth_passwd,
243: &options.password_authentication,
1.23 markus 244: &options.batch_mode},
245: {"none",
246: userauth_none,
247: NULL,
248: NULL},
1.20 markus 249: {NULL, NULL, NULL, NULL}
250: };
251:
252: void
1.68 markus 253: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 254: Sensitive *sensitive)
1.20 markus 255: {
256: Authctxt authctxt;
257: int type;
1.39 markus 258:
1.73 markus 259: if (options.challenge_response_authentication)
1.39 markus 260: options.kbd_interactive_authentication = 1;
1.20 markus 261:
262: packet_start(SSH2_MSG_SERVICE_REQUEST);
263: packet_put_cstring("ssh-userauth");
264: packet_send();
1.108 markus 265: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 266: packet_write_wait();
1.91 markus 267: type = packet_read();
1.108 markus 268: if (type != SSH2_MSG_SERVICE_ACCEPT)
269: fatal("Server denied authentication request: %d", type);
1.20 markus 270: if (packet_remaining() > 0) {
1.91 markus 271: char *reply = packet_get_string(NULL);
1.108 markus 272: debug2("service_accept: %s", reply);
1.20 markus 273: xfree(reply);
274: } else {
1.109 markus 275: debug2("buggy server: service_accept w/o service");
1.20 markus 276: }
1.90 markus 277: packet_check_eom();
1.108 markus 278: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 279:
1.53 markus 280: if (options.preferred_authentications == NULL)
281: options.preferred_authentications = authmethods_get();
282:
1.20 markus 283: /* setup authentication context */
1.82 markus 284: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 285: pubkey_prepare(&authctxt);
1.20 markus 286: authctxt.server_user = server_user;
1.68 markus 287: authctxt.local_user = local_user;
1.20 markus 288: authctxt.host = host;
289: authctxt.service = "ssh-connection"; /* service name */
290: authctxt.success = 0;
1.23 markus 291: authctxt.method = authmethod_lookup("none");
1.51 markus 292: authctxt.authlist = NULL;
1.121 markus 293: authctxt.methoddata = NULL;
1.100 markus 294: authctxt.sensitive = sensitive;
1.82 markus 295: authctxt.info_req_seen = 0;
1.23 markus 296: if (authctxt.method == NULL)
297: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 298:
299: /* initial userauth request */
1.23 markus 300: userauth_none(&authctxt);
1.20 markus 301:
1.65 markus 302: dispatch_init(&input_userauth_error);
1.20 markus 303: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
304: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 305: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 306: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
307:
1.117 markus 308: pubkey_cleanup(&authctxt);
1.119 markus 309: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
310:
1.109 markus 311: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 312: }
1.119 markus 313:
1.20 markus 314: void
1.51 markus 315: userauth(Authctxt *authctxt, char *authlist)
316: {
1.121 markus 317: if (authctxt->methoddata) {
318: xfree(authctxt->methoddata);
319: authctxt->methoddata = NULL;
320: }
1.51 markus 321: if (authlist == NULL) {
322: authlist = authctxt->authlist;
323: } else {
324: if (authctxt->authlist)
325: xfree(authctxt->authlist);
326: authctxt->authlist = authlist;
327: }
328: for (;;) {
329: Authmethod *method = authmethod_get(authlist);
330: if (method == NULL)
331: fatal("Permission denied (%s).", authlist);
332: authctxt->method = method;
1.119 markus 333:
334: /* reset the per method handler */
335: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
336: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
337:
338: /* and try new method */
1.51 markus 339: if (method->userauth(authctxt) != 0) {
340: debug2("we sent a %s packet, wait for reply", method->name);
341: break;
342: } else {
343: debug2("we did not send a packet, disable method");
344: method->enabled = NULL;
345: }
346: }
347: }
1.105 deraadt 348:
1.51 markus 349: void
1.92 markus 350: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 351: {
1.35 markus 352: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 353: "type %d", type);
1.35 markus 354: }
1.105 deraadt 355:
1.35 markus 356: void
1.92 markus 357: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 358: {
359: char *msg, *lang;
1.126 deraadt 360:
1.35 markus 361: debug3("input_userauth_banner");
362: msg = packet_get_string(NULL);
363: lang = packet_get_string(NULL);
1.125 dtucker 364: if (options.log_level > SYSLOG_LEVEL_QUIET)
365: fprintf(stderr, "%s", msg);
1.35 markus 366: xfree(msg);
367: xfree(lang);
1.20 markus 368: }
1.105 deraadt 369:
1.20 markus 370: void
1.92 markus 371: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 372: {
373: Authctxt *authctxt = ctxt;
374: if (authctxt == NULL)
375: fatal("input_userauth_success: no authentication context");
1.126 deraadt 376: if (authctxt->authlist) {
1.51 markus 377: xfree(authctxt->authlist);
1.126 deraadt 378: authctxt->authlist = NULL;
379: }
380: if (authctxt->methoddata) {
1.121 markus 381: xfree(authctxt->methoddata);
1.126 deraadt 382: authctxt->methoddata = NULL;
383: }
1.20 markus 384: authctxt->success = 1; /* break out */
385: }
1.105 deraadt 386:
1.20 markus 387: void
1.92 markus 388: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 389: {
390: Authctxt *authctxt = ctxt;
391: char *authlist = NULL;
392: int partial;
393:
394: if (authctxt == NULL)
395: fatal("input_userauth_failure: no authentication context");
396:
1.23 markus 397: authlist = packet_get_string(NULL);
1.20 markus 398: partial = packet_get_char();
1.90 markus 399: packet_check_eom();
1.20 markus 400:
401: if (partial != 0)
1.116 itojun 402: logit("Authenticated with partial success.");
1.109 markus 403: debug("Authentications that can continue: %s", authlist);
1.20 markus 404:
1.51 markus 405: userauth(authctxt, authlist);
406: }
407: void
1.92 markus 408: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 409: {
410: Authctxt *authctxt = ctxt;
411: Key *key = NULL;
1.117 markus 412: Identity *id = NULL;
1.51 markus 413: Buffer b;
1.96 markus 414: int pktype, sent = 0;
415: u_int alen, blen;
416: char *pkalg, *fp;
417: u_char *pkblob;
1.51 markus 418:
419: if (authctxt == NULL)
420: fatal("input_userauth_pk_ok: no authentication context");
421: if (datafellows & SSH_BUG_PKOK) {
422: /* this is similar to SSH_BUG_PKAUTH */
423: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
424: pkblob = packet_get_string(&blen);
425: buffer_init(&b);
426: buffer_append(&b, pkblob, blen);
427: pkalg = buffer_get_string(&b, &alen);
428: buffer_free(&b);
429: } else {
430: pkalg = packet_get_string(&alen);
431: pkblob = packet_get_string(&blen);
432: }
1.90 markus 433: packet_check_eom();
1.51 markus 434:
1.117 markus 435: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 436:
1.117 markus 437: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
438: debug("unknown pkalg %s", pkalg);
439: goto done;
440: }
441: if ((key = key_from_blob(pkblob, blen)) == NULL) {
442: debug("no key from blob. pkalg %s", pkalg);
443: goto done;
444: }
445: if (key->type != pktype) {
446: error("input_userauth_pk_ok: type mismatch "
447: "for decoded key (received %d, expected %d)",
448: key->type, pktype);
449: goto done;
450: }
451: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
452: debug2("input_userauth_pk_ok: fp %s", fp);
453: xfree(fp);
454:
1.127 markus 455: /*
456: * search keys in the reverse order, because last candidate has been
457: * moved to the end of the queue. this also avoids confusion by
458: * duplicate keys
459: */
1.136 henning 460: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 461: if (key_equal(key, id->key)) {
462: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 463: break;
464: }
1.117 markus 465: }
466: done:
1.51 markus 467: if (key != NULL)
468: key_free(key);
469: xfree(pkalg);
470: xfree(pkblob);
471:
1.106 deraadt 472: /* try another method if we did not send a packet */
1.51 markus 473: if (sent == 0)
474: userauth(authctxt, NULL);
1.20 markus 475: }
1.121 markus 476:
477: #ifdef GSSAPI
1.133 djm 478: int
1.121 markus 479: userauth_gssapi(Authctxt *authctxt)
480: {
481: Gssctxt *gssctxt = NULL;
1.128 avsm 482: static gss_OID_set gss_supported = NULL;
1.139 djm 483: static u_int mech = 0;
1.121 markus 484: OM_uint32 min;
485: int ok = 0;
486:
487: /* Try one GSSAPI method at a time, rather than sending them all at
488: * once. */
489:
1.128 avsm 490: if (gss_supported == NULL)
491: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 492:
493: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 494: while (mech < gss_supported->count && !ok) {
1.121 markus 495: if (gssctxt)
496: ssh_gssapi_delete_ctx(&gssctxt);
497: ssh_gssapi_build_ctx(&gssctxt);
1.128 avsm 498: ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
1.121 markus 499:
500: /* My DER encoding requires length<128 */
1.128 avsm 501: if (gss_supported->elements[mech].length < 128 &&
1.121 markus 502: !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
503: authctxt->host))) {
504: ok = 1; /* Mechanism works */
505: } else {
506: mech++;
507: }
508: }
509:
1.139 djm 510: if (!ok)
511: return 0;
1.121 markus 512:
513: authctxt->methoddata=(void *)gssctxt;
514:
515: packet_start(SSH2_MSG_USERAUTH_REQUEST);
516: packet_put_cstring(authctxt->server_user);
517: packet_put_cstring(authctxt->service);
518: packet_put_cstring(authctxt->method->name);
519:
520: packet_put_int(1);
521:
1.129 markus 522: packet_put_int((gss_supported->elements[mech].length) + 2);
523: packet_put_char(SSH_GSS_OIDTYPE);
524: packet_put_char(gss_supported->elements[mech].length);
525: packet_put_raw(gss_supported->elements[mech].elements,
526: gss_supported->elements[mech].length);
1.121 markus 527:
528: packet_send();
529:
530: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
531: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
532: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
533: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
534:
535: mech++; /* Move along to next candidate */
536:
537: return 1;
538: }
539:
1.130 markus 540: static OM_uint32
541: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
542: {
543: Authctxt *authctxt = ctxt;
544: Gssctxt *gssctxt = authctxt->methoddata;
545: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 546: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
547: gss_buffer_desc gssbuf;
1.132 markus 548: OM_uint32 status, ms, flags;
549: Buffer b;
1.133 djm 550:
1.130 markus 551: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 552: recv_tok, &send_tok, &flags);
1.130 markus 553:
554: if (send_tok.length > 0) {
555: if (GSS_ERROR(status))
556: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
557: else
558: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 559:
1.130 markus 560: packet_put_string(send_tok.value, send_tok.length);
561: packet_send();
562: gss_release_buffer(&ms, &send_tok);
563: }
1.133 djm 564:
1.130 markus 565: if (status == GSS_S_COMPLETE) {
1.132 markus 566: /* send either complete or MIC, depending on mechanism */
567: if (!(flags & GSS_C_INTEG_FLAG)) {
568: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
569: packet_send();
570: } else {
571: ssh_gssapi_buildmic(&b, authctxt->server_user,
572: authctxt->service, "gssapi-with-mic");
573:
574: gssbuf.value = buffer_ptr(&b);
575: gssbuf.length = buffer_len(&b);
1.133 djm 576:
1.132 markus 577: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 578:
1.132 markus 579: if (!GSS_ERROR(status)) {
580: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
581: packet_put_string(mic.value, mic.length);
1.133 djm 582:
1.132 markus 583: packet_send();
584: }
1.133 djm 585:
1.132 markus 586: buffer_free(&b);
587: gss_release_buffer(&ms, &mic);
1.133 djm 588: }
1.130 markus 589: }
1.133 djm 590:
1.130 markus 591: return status;
592: }
593:
1.121 markus 594: void
595: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
596: {
597: Authctxt *authctxt = ctxt;
598: Gssctxt *gssctxt;
599: int oidlen;
600: char *oidv;
601:
602: if (authctxt == NULL)
603: fatal("input_gssapi_response: no authentication context");
604: gssctxt = authctxt->methoddata;
605:
606: /* Setup our OID */
607: oidv = packet_get_string(&oidlen);
608:
1.129 markus 609: if (oidlen <= 2 ||
610: oidv[0] != SSH_GSS_OIDTYPE ||
611: oidv[1] != oidlen - 2) {
1.130 markus 612: xfree(oidv);
1.129 markus 613: debug("Badly encoded mechanism OID received");
614: userauth(authctxt, NULL);
615: return;
1.121 markus 616: }
1.129 markus 617:
618: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
619: fatal("Server returned different OID than expected");
1.121 markus 620:
621: packet_check_eom();
622:
623: xfree(oidv);
624:
1.130 markus 625: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 626: /* Start again with next method on list */
627: debug("Trying to start again");
628: userauth(authctxt, NULL);
629: return;
630: }
631: }
632:
633: void
634: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
635: {
636: Authctxt *authctxt = ctxt;
637: gss_buffer_desc recv_tok;
1.130 markus 638: OM_uint32 status;
1.121 markus 639: u_int slen;
640:
641: if (authctxt == NULL)
642: fatal("input_gssapi_response: no authentication context");
643:
644: recv_tok.value = packet_get_string(&slen);
645: recv_tok.length = slen; /* safe typecast */
646:
647: packet_check_eom();
648:
1.130 markus 649: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 650:
651: xfree(recv_tok.value);
652:
653: if (GSS_ERROR(status)) {
654: /* Start again with the next method in the list */
655: userauth(authctxt, NULL);
656: return;
657: }
658: }
659:
660: void
661: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
662: {
663: Authctxt *authctxt = ctxt;
664: Gssctxt *gssctxt;
665: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
666: gss_buffer_desc recv_tok;
667: OM_uint32 status, ms;
1.123 deraadt 668: u_int len;
1.121 markus 669:
670: if (authctxt == NULL)
671: fatal("input_gssapi_response: no authentication context");
672: gssctxt = authctxt->methoddata;
673:
1.123 deraadt 674: recv_tok.value = packet_get_string(&len);
675: recv_tok.length = len;
1.121 markus 676:
677: packet_check_eom();
678:
679: /* Stick it into GSSAPI and see what it says */
680: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 681: &recv_tok, &send_tok, NULL);
1.121 markus 682:
683: xfree(recv_tok.value);
684: gss_release_buffer(&ms, &send_tok);
685:
686: /* Server will be returning a failed packet after this one */
687: }
688:
689: void
690: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
691: {
692: OM_uint32 maj, min;
693: char *msg;
694: char *lang;
695:
696: maj=packet_get_int();
697: min=packet_get_int();
698: msg=packet_get_string(NULL);
699: lang=packet_get_string(NULL);
700:
701: packet_check_eom();
702:
1.143 ! stevesk 703: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 704: xfree(msg);
705: xfree(lang);
706: }
707: #endif /* GSSAPI */
1.20 markus 708:
1.1 markus 709: int
1.23 markus 710: userauth_none(Authctxt *authctxt)
711: {
712: /* initial userauth request */
713: packet_start(SSH2_MSG_USERAUTH_REQUEST);
714: packet_put_cstring(authctxt->server_user);
715: packet_put_cstring(authctxt->service);
716: packet_put_cstring(authctxt->method->name);
717: packet_send();
718: return 1;
719: }
720:
721: int
1.20 markus 722: userauth_passwd(Authctxt *authctxt)
1.1 markus 723: {
1.6 markus 724: static int attempt = 0;
1.99 markus 725: char prompt[150];
1.1 markus 726: char *password;
1.6 markus 727:
1.13 todd 728: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 729: return 0;
1.13 todd 730:
1.87 deraadt 731: if (attempt != 1)
1.13 todd 732: error("Permission denied, please try again.");
1.1 markus 733:
1.43 itojun 734: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 735: authctxt->server_user, authctxt->host);
1.1 markus 736: password = read_passphrase(prompt, 0);
737: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 738: packet_put_cstring(authctxt->server_user);
739: packet_put_cstring(authctxt->service);
1.23 markus 740: packet_put_cstring(authctxt->method->name);
1.1 markus 741: packet_put_char(0);
1.49 markus 742: packet_put_cstring(password);
1.1 markus 743: memset(password, 0, strlen(password));
744: xfree(password);
1.85 markus 745: packet_add_padding(64);
1.1 markus 746: packet_send();
1.99 markus 747:
1.104 deraadt 748: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 749: &input_userauth_passwd_changereq);
750:
1.1 markus 751: return 1;
752: }
1.99 markus 753: /*
754: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
755: */
756: void
757: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
758: {
759: Authctxt *authctxt = ctxt;
760: char *info, *lang, *password = NULL, *retype = NULL;
761: char prompt[150];
762:
763: debug2("input_userauth_passwd_changereq");
764:
765: if (authctxt == NULL)
766: fatal("input_userauth_passwd_changereq: "
767: "no authentication context");
768:
769: info = packet_get_string(NULL);
770: lang = packet_get_string(NULL);
771: if (strlen(info) > 0)
1.116 itojun 772: logit("%s", info);
1.99 markus 773: xfree(info);
774: xfree(lang);
775: packet_start(SSH2_MSG_USERAUTH_REQUEST);
776: packet_put_cstring(authctxt->server_user);
777: packet_put_cstring(authctxt->service);
778: packet_put_cstring(authctxt->method->name);
779: packet_put_char(1); /* additional info */
1.104 deraadt 780: snprintf(prompt, sizeof(prompt),
1.99 markus 781: "Enter %.30s@%.128s's old password: ",
782: authctxt->server_user, authctxt->host);
783: password = read_passphrase(prompt, 0);
784: packet_put_cstring(password);
785: memset(password, 0, strlen(password));
786: xfree(password);
787: password = NULL;
788: while (password == NULL) {
1.104 deraadt 789: snprintf(prompt, sizeof(prompt),
1.99 markus 790: "Enter %.30s@%.128s's new password: ",
791: authctxt->server_user, authctxt->host);
792: password = read_passphrase(prompt, RP_ALLOW_EOF);
793: if (password == NULL) {
794: /* bail out */
795: return;
796: }
1.104 deraadt 797: snprintf(prompt, sizeof(prompt),
1.99 markus 798: "Retype %.30s@%.128s's new password: ",
799: authctxt->server_user, authctxt->host);
800: retype = read_passphrase(prompt, 0);
801: if (strcmp(password, retype) != 0) {
802: memset(password, 0, strlen(password));
803: xfree(password);
1.116 itojun 804: logit("Mismatch; try again, EOF to quit.");
1.99 markus 805: password = NULL;
806: }
807: memset(retype, 0, strlen(retype));
808: xfree(retype);
809: }
810: packet_put_cstring(password);
811: memset(password, 0, strlen(password));
812: xfree(password);
813: packet_add_padding(64);
814: packet_send();
1.104 deraadt 815:
816: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 817: &input_userauth_passwd_changereq);
1.117 markus 818: }
819:
820: static int
821: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
822: u_char *data, u_int datalen)
823: {
824: Key *prv;
825: int ret;
1.99 markus 826:
1.117 markus 827: /* the agent supports this key */
828: if (id->ac)
829: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
830: data, datalen));
831: /*
832: * we have already loaded the private key or
833: * the private key is stored in external hardware
834: */
835: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
836: return (key_sign(id->key, sigp, lenp, data, datalen));
837: /* load the private key from the file */
838: if ((prv = load_identity_file(id->filename)) == NULL)
839: return (-1);
840: ret = key_sign(prv, sigp, lenp, data, datalen);
841: key_free(prv);
842: return (ret);
1.51 markus 843: }
844:
1.76 itojun 845: static int
1.117 markus 846: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 847: {
848: Buffer b;
1.32 markus 849: u_char *blob, *signature;
1.96 markus 850: u_int bloblen, slen;
1.120 markus 851: u_int skip = 0;
1.17 markus 852: int ret = -1;
1.23 markus 853: int have_sig = 1;
1.1 markus 854:
1.30 markus 855: debug3("sign_and_send_pubkey");
1.51 markus 856:
1.117 markus 857: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 858: /* we cannot handle this key */
1.30 markus 859: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 860: return 0;
861: }
1.1 markus 862: /* data to be signed */
863: buffer_init(&b);
1.26 markus 864: if (datafellows & SSH_OLD_SESSIONID) {
865: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 866: skip = session_id2_len;
1.26 markus 867: } else {
1.14 markus 868: buffer_put_string(&b, session_id2, session_id2_len);
869: skip = buffer_len(&b);
870: }
1.1 markus 871: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 872: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 873: buffer_put_cstring(&b,
1.30 markus 874: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 875: "ssh-userauth" :
1.20 markus 876: authctxt->service);
1.30 markus 877: if (datafellows & SSH_BUG_PKAUTH) {
878: buffer_put_char(&b, have_sig);
879: } else {
880: buffer_put_cstring(&b, authctxt->method->name);
881: buffer_put_char(&b, have_sig);
1.117 markus 882: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 883: }
1.1 markus 884: buffer_put_string(&b, blob, bloblen);
885:
886: /* generate signature */
1.117 markus 887: ret = identity_sign(id, &signature, &slen,
1.51 markus 888: buffer_ptr(&b), buffer_len(&b));
1.17 markus 889: if (ret == -1) {
890: xfree(blob);
891: buffer_free(&b);
892: return 0;
893: }
1.28 markus 894: #ifdef DEBUG_PK
1.1 markus 895: buffer_dump(&b);
896: #endif
1.30 markus 897: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 898: buffer_clear(&b);
899: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 900: skip = session_id2_len;
1.10 markus 901: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 902: buffer_put_cstring(&b, authctxt->server_user);
903: buffer_put_cstring(&b, authctxt->service);
1.23 markus 904: buffer_put_cstring(&b, authctxt->method->name);
905: buffer_put_char(&b, have_sig);
1.30 markus 906: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 907: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 908: buffer_put_string(&b, blob, bloblen);
909: }
910: xfree(blob);
1.51 markus 911:
1.1 markus 912: /* append signature */
913: buffer_put_string(&b, signature, slen);
914: xfree(signature);
915:
916: /* skip session id and packet type */
1.14 markus 917: if (buffer_len(&b) < skip + 1)
1.20 markus 918: fatal("userauth_pubkey: internal error");
1.14 markus 919: buffer_consume(&b, skip + 1);
1.1 markus 920:
921: /* put remaining data from buffer into packet */
922: packet_start(SSH2_MSG_USERAUTH_REQUEST);
923: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
924: buffer_free(&b);
925: packet_send();
1.17 markus 926:
927: return 1;
1.16 markus 928: }
929:
1.76 itojun 930: static int
1.117 markus 931: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 932: {
1.51 markus 933: u_char *blob;
1.97 markus 934: u_int bloblen, have_sig = 0;
1.20 markus 935:
1.51 markus 936: debug3("send_pubkey_test");
1.16 markus 937:
1.117 markus 938: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 939: /* we cannot handle this key */
940: debug3("send_pubkey_test: cannot handle key");
1.16 markus 941: return 0;
942: }
1.51 markus 943: /* register callback for USERAUTH_PK_OK message */
944: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
945:
946: packet_start(SSH2_MSG_USERAUTH_REQUEST);
947: packet_put_cstring(authctxt->server_user);
948: packet_put_cstring(authctxt->service);
949: packet_put_cstring(authctxt->method->name);
950: packet_put_char(have_sig);
951: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 952: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 953: packet_put_string(blob, bloblen);
954: xfree(blob);
955: packet_send();
956: return 1;
957: }
958:
1.76 itojun 959: static Key *
1.51 markus 960: load_identity_file(char *filename)
961: {
962: Key *private;
963: char prompt[300], *passphrase;
1.56 markus 964: int quit, i;
1.52 markus 965: struct stat st;
1.16 markus 966:
1.52 markus 967: if (stat(filename, &st) < 0) {
968: debug3("no such identity: %s", filename);
969: return NULL;
970: }
1.56 markus 971: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
972: if (private == NULL) {
973: if (options.batch_mode)
1.51 markus 974: return NULL;
1.16 markus 975: snprintf(prompt, sizeof prompt,
1.88 deraadt 976: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 977: for (i = 0; i < options.number_of_password_prompts; i++) {
978: passphrase = read_passphrase(prompt, 0);
979: if (strcmp(passphrase, "") != 0) {
1.56 markus 980: private = key_load_private_type(KEY_UNSPEC, filename,
981: passphrase, NULL);
1.51 markus 982: quit = 0;
1.20 markus 983: } else {
984: debug2("no passphrase given, try next key");
1.51 markus 985: quit = 1;
1.20 markus 986: }
987: memset(passphrase, 0, strlen(passphrase));
988: xfree(passphrase);
1.56 markus 989: if (private != NULL || quit)
1.20 markus 990: break;
991: debug2("bad passphrase given, try again...");
1.16 markus 992: }
993: }
1.51 markus 994: return private;
995: }
996:
1.117 markus 997: /*
998: * try keys in the following order:
999: * 1. agent keys that are found in the config file
1000: * 2. other agent keys
1001: * 3. keys that are only listed in the config file
1002: */
1003: static void
1004: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1005: {
1.117 markus 1006: Identity *id;
1007: Idlist agent, files, *preferred;
1008: Key *key;
1009: AuthenticationConnection *ac;
1010: char *comment;
1011: int i, found;
1.51 markus 1012:
1.117 markus 1013: TAILQ_INIT(&agent); /* keys from the agent */
1014: TAILQ_INIT(&files); /* keys from the config file */
1015: preferred = &authctxt->keys;
1016: TAILQ_INIT(preferred); /* preferred order of keys */
1017:
1018: /* list of keys stored in the filesystem */
1019: for (i = 0; i < options.num_identity_files; i++) {
1020: key = options.identity_keys[i];
1021: if (key && key->type == KEY_RSA1)
1022: continue;
1023: options.identity_keys[i] = NULL;
1024: id = xmalloc(sizeof(*id));
1025: memset(id, 0, sizeof(*id));
1026: id->key = key;
1027: id->filename = xstrdup(options.identity_files[i]);
1028: TAILQ_INSERT_TAIL(&files, id, next);
1029: }
1030: /* list of keys supported by the agent */
1031: if ((ac = ssh_get_authentication_connection())) {
1032: for (key = ssh_get_first_identity(ac, &comment, 2);
1033: key != NULL;
1034: key = ssh_get_next_identity(ac, &comment, 2)) {
1035: found = 0;
1036: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1037: /* agent keys from the config file are preferred */
1.117 markus 1038: if (key_equal(key, id->key)) {
1039: key_free(key);
1040: xfree(comment);
1041: TAILQ_REMOVE(&files, id, next);
1042: TAILQ_INSERT_TAIL(preferred, id, next);
1043: id->ac = ac;
1044: found = 1;
1045: break;
1046: }
1047: }
1.135 markus 1048: if (!found && !options.identities_only) {
1.117 markus 1049: id = xmalloc(sizeof(*id));
1050: memset(id, 0, sizeof(*id));
1051: id->key = key;
1052: id->filename = comment;
1053: id->ac = ac;
1054: TAILQ_INSERT_TAIL(&agent, id, next);
1055: }
1056: }
1057: /* append remaining agent keys */
1058: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1059: TAILQ_REMOVE(&agent, id, next);
1060: TAILQ_INSERT_TAIL(preferred, id, next);
1061: }
1062: authctxt->agent = ac;
1063: }
1064: /* append remaining keys from the config file */
1065: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1066: TAILQ_REMOVE(&files, id, next);
1067: TAILQ_INSERT_TAIL(preferred, id, next);
1068: }
1069: TAILQ_FOREACH(id, preferred, next) {
1070: debug2("key: %s (%p)", id->filename, id->key);
1071: }
1.17 markus 1072: }
1073:
1.117 markus 1074: static void
1075: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1076: {
1.117 markus 1077: Identity *id;
1.51 markus 1078:
1.117 markus 1079: if (authctxt->agent != NULL)
1080: ssh_close_authentication_connection(authctxt->agent);
1081: for (id = TAILQ_FIRST(&authctxt->keys); id;
1082: id = TAILQ_FIRST(&authctxt->keys)) {
1083: TAILQ_REMOVE(&authctxt->keys, id, next);
1084: if (id->key)
1085: key_free(id->key);
1086: if (id->filename)
1087: xfree(id->filename);
1088: xfree(id);
1089: }
1.1 markus 1090: }
1091:
1.20 markus 1092: int
1093: userauth_pubkey(Authctxt *authctxt)
1094: {
1.117 markus 1095: Identity *id;
1.20 markus 1096: int sent = 0;
1097:
1.117 markus 1098: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1099: if (id->tried++)
1100: return (0);
1.127 markus 1101: /* move key to the end of the queue */
1.117 markus 1102: TAILQ_REMOVE(&authctxt->keys, id, next);
1103: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1104: /*
1105: * send a test message if we have the public key. for
1106: * encrypted keys we cannot do this and have to load the
1107: * private key instead
1108: */
1109: if (id->key && id->key->type != KEY_RSA1) {
1110: debug("Offering public key: %s", id->filename);
1111: sent = send_pubkey_test(authctxt, id);
1112: } else if (id->key == NULL) {
1113: debug("Trying private key: %s", id->filename);
1114: id->key = load_identity_file(id->filename);
1115: if (id->key != NULL) {
1116: id->isprivate = 1;
1117: sent = sign_and_send_pubkey(authctxt, id);
1118: key_free(id->key);
1119: id->key = NULL;
1.51 markus 1120: }
1121: }
1.117 markus 1122: if (sent)
1123: return (sent);
1.28 markus 1124: }
1.117 markus 1125: return (0);
1.20 markus 1126: }
1127:
1.23 markus 1128: /*
1129: * Send userauth request message specifying keyboard-interactive method.
1130: */
1131: int
1132: userauth_kbdint(Authctxt *authctxt)
1133: {
1134: static int attempt = 0;
1135:
1136: if (attempt++ >= options.number_of_password_prompts)
1137: return 0;
1.82 markus 1138: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1139: if (attempt > 1 && !authctxt->info_req_seen) {
1140: debug3("userauth_kbdint: disable: no info_req_seen");
1141: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1142: return 0;
1143: }
1.23 markus 1144:
1145: debug2("userauth_kbdint");
1146: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1147: packet_put_cstring(authctxt->server_user);
1148: packet_put_cstring(authctxt->service);
1149: packet_put_cstring(authctxt->method->name);
1150: packet_put_cstring(""); /* lang */
1151: packet_put_cstring(options.kbd_interactive_devices ?
1152: options.kbd_interactive_devices : "");
1153: packet_send();
1154:
1155: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1156: return 1;
1157: }
1158:
1159: /*
1.46 markus 1160: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1161: */
1162: void
1.92 markus 1163: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1164: {
1165: Authctxt *authctxt = ctxt;
1.46 markus 1166: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1167: u_int num_prompts, i;
1.23 markus 1168: int echo = 0;
1169:
1170: debug2("input_userauth_info_req");
1171:
1172: if (authctxt == NULL)
1173: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1174:
1175: authctxt->info_req_seen = 1;
1.23 markus 1176:
1177: name = packet_get_string(NULL);
1178: inst = packet_get_string(NULL);
1179: lang = packet_get_string(NULL);
1180: if (strlen(name) > 0)
1.116 itojun 1181: logit("%s", name);
1.23 markus 1182: if (strlen(inst) > 0)
1.116 itojun 1183: logit("%s", inst);
1.46 markus 1184: xfree(name);
1.23 markus 1185: xfree(inst);
1.46 markus 1186: xfree(lang);
1.23 markus 1187:
1188: num_prompts = packet_get_int();
1189: /*
1190: * Begin to build info response packet based on prompts requested.
1191: * We commit to providing the correct number of responses, so if
1192: * further on we run into a problem that prevents this, we have to
1193: * be sure and clean this up and send a correct error response.
1194: */
1195: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1196: packet_put_int(num_prompts);
1197:
1.73 markus 1198: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1199: for (i = 0; i < num_prompts; i++) {
1200: prompt = packet_get_string(NULL);
1201: echo = packet_get_char();
1202:
1.77 markus 1203: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1204:
1.49 markus 1205: packet_put_cstring(response);
1.23 markus 1206: memset(response, 0, strlen(response));
1207: xfree(response);
1208: xfree(prompt);
1209: }
1.90 markus 1210: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1211:
1.85 markus 1212: packet_add_padding(64);
1.23 markus 1213: packet_send();
1.68 markus 1214: }
1215:
1.100 markus 1216: static int
1.105 deraadt 1217: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1218: u_char *data, u_int datalen)
1219: {
1220: Buffer b;
1.101 markus 1221: struct stat st;
1.100 markus 1222: pid_t pid;
1.103 markus 1223: int to[2], from[2], status, version = 2;
1.100 markus 1224:
1.109 markus 1225: debug2("ssh_keysign called");
1.100 markus 1226:
1.101 markus 1227: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1228: error("ssh_keysign: no installed: %s", strerror(errno));
1229: return -1;
1230: }
1.100 markus 1231: if (fflush(stdout) != 0)
1232: error("ssh_keysign: fflush: %s", strerror(errno));
1233: if (pipe(to) < 0) {
1234: error("ssh_keysign: pipe: %s", strerror(errno));
1235: return -1;
1236: }
1237: if (pipe(from) < 0) {
1238: error("ssh_keysign: pipe: %s", strerror(errno));
1239: return -1;
1240: }
1241: if ((pid = fork()) < 0) {
1242: error("ssh_keysign: fork: %s", strerror(errno));
1243: return -1;
1244: }
1245: if (pid == 0) {
1246: seteuid(getuid());
1247: setuid(getuid());
1248: close(from[0]);
1249: if (dup2(from[1], STDOUT_FILENO) < 0)
1250: fatal("ssh_keysign: dup2: %s", strerror(errno));
1251: close(to[1]);
1252: if (dup2(to[0], STDIN_FILENO) < 0)
1253: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1254: close(from[1]);
1255: close(to[0]);
1.102 markus 1256: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1257: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1258: strerror(errno));
1259: }
1260: close(from[1]);
1261: close(to[0]);
1262:
1263: buffer_init(&b);
1.103 markus 1264: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1265: buffer_put_string(&b, data, datalen);
1.131 djm 1266: if (ssh_msg_send(to[1], version, &b) == -1)
1267: fatal("ssh_keysign: couldn't send request");
1.100 markus 1268:
1.110 djm 1269: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1270: error("ssh_keysign: no reply");
1.134 markus 1271: buffer_free(&b);
1.100 markus 1272: return -1;
1273: }
1.101 markus 1274: close(from[0]);
1275: close(to[1]);
1276:
1.103 markus 1277: while (waitpid(pid, &status, 0) < 0)
1278: if (errno != EINTR)
1279: break;
1.101 markus 1280:
1.100 markus 1281: if (buffer_get_char(&b) != version) {
1.101 markus 1282: error("ssh_keysign: bad version");
1.134 markus 1283: buffer_free(&b);
1.100 markus 1284: return -1;
1285: }
1286: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1287: buffer_free(&b);
1.100 markus 1288:
1289: return 0;
1290: }
1291:
1.68 markus 1292: int
1293: userauth_hostbased(Authctxt *authctxt)
1294: {
1295: Key *private = NULL;
1.100 markus 1296: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1297: Buffer b;
1298: u_char *signature, *blob;
1299: char *chost, *pkalg, *p;
1.72 markus 1300: const char *service;
1.68 markus 1301: u_int blen, slen;
1.71 markus 1302: int ok, i, len, found = 0;
1.68 markus 1303:
1304: /* check for a useful key */
1.100 markus 1305: for (i = 0; i < sensitive->nkeys; i++) {
1306: private = sensitive->keys[i];
1.68 markus 1307: if (private && private->type != KEY_RSA1) {
1308: found = 1;
1309: /* we take and free the key */
1.100 markus 1310: sensitive->keys[i] = NULL;
1.68 markus 1311: break;
1312: }
1313: }
1314: if (!found) {
1.109 markus 1315: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1316: return 0;
1317: }
1318: if (key_to_blob(private, &blob, &blen) == 0) {
1319: key_free(private);
1320: return 0;
1321: }
1.84 markus 1322: /* figure out a name for the client host */
1323: p = get_local_name(packet_get_connection_in());
1324: if (p == NULL) {
1325: error("userauth_hostbased: cannot get local ipaddr/name");
1326: key_free(private);
1327: return 0;
1328: }
1329: len = strlen(p) + 2;
1330: chost = xmalloc(len);
1331: strlcpy(chost, p, len);
1332: strlcat(chost, ".", len);
1333: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1334: xfree(p);
1.84 markus 1335:
1.72 markus 1336: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1337: authctxt->service;
1.68 markus 1338: pkalg = xstrdup(key_ssh_name(private));
1339: buffer_init(&b);
1340: /* construct data */
1.72 markus 1341: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1342: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1343: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1344: buffer_put_cstring(&b, service);
1.68 markus 1345: buffer_put_cstring(&b, authctxt->method->name);
1346: buffer_put_cstring(&b, pkalg);
1347: buffer_put_string(&b, blob, blen);
1348: buffer_put_cstring(&b, chost);
1349: buffer_put_cstring(&b, authctxt->local_user);
1350: #ifdef DEBUG_PK
1351: buffer_dump(&b);
1352: #endif
1.100 markus 1353: if (sensitive->external_keysign)
1354: ok = ssh_keysign(private, &signature, &slen,
1355: buffer_ptr(&b), buffer_len(&b));
1356: else
1357: ok = key_sign(private, &signature, &slen,
1358: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1359: key_free(private);
1360: buffer_free(&b);
1361: if (ok != 0) {
1362: error("key_sign failed");
1363: xfree(chost);
1364: xfree(pkalg);
1365: return 0;
1366: }
1367: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1368: packet_put_cstring(authctxt->server_user);
1369: packet_put_cstring(authctxt->service);
1370: packet_put_cstring(authctxt->method->name);
1371: packet_put_cstring(pkalg);
1372: packet_put_string(blob, blen);
1373: packet_put_cstring(chost);
1374: packet_put_cstring(authctxt->local_user);
1375: packet_put_string(signature, slen);
1376: memset(signature, 's', slen);
1377: xfree(signature);
1378: xfree(chost);
1379: xfree(pkalg);
1380:
1381: packet_send();
1382: return 1;
1.23 markus 1383: }
1.20 markus 1384:
1385: /* find auth method */
1386:
1387: /*
1388: * given auth method name, if configurable options permit this method fill
1389: * in auth_ident field and return true, otherwise return false.
1390: */
1.76 itojun 1391: static int
1.20 markus 1392: authmethod_is_enabled(Authmethod *method)
1393: {
1394: if (method == NULL)
1395: return 0;
1396: /* return false if options indicate this method is disabled */
1397: if (method->enabled == NULL || *method->enabled == 0)
1398: return 0;
1399: /* return false if batch mode is enabled but method needs interactive mode */
1400: if (method->batch_flag != NULL && *method->batch_flag != 0)
1401: return 0;
1402: return 1;
1403: }
1404:
1.76 itojun 1405: static Authmethod *
1.20 markus 1406: authmethod_lookup(const char *name)
1.1 markus 1407: {
1.20 markus 1408: Authmethod *method = NULL;
1409: if (name != NULL)
1410: for (method = authmethods; method->name != NULL; method++)
1411: if (strcmp(name, method->name) == 0)
1412: return method;
1413: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1414: return NULL;
1415: }
1.1 markus 1416:
1.53 markus 1417: /* XXX internal state */
1418: static Authmethod *current = NULL;
1419: static char *supported = NULL;
1420: static char *preferred = NULL;
1.105 deraadt 1421:
1.20 markus 1422: /*
1423: * Given the authentication method list sent by the server, return the
1424: * next method we should try. If the server initially sends a nil list,
1.67 markus 1425: * use a built-in default list.
1.41 stevesk 1426: */
1.76 itojun 1427: static Authmethod *
1.20 markus 1428: authmethod_get(char *authlist)
1429: {
1.53 markus 1430: char *name = NULL;
1.97 markus 1431: u_int next;
1.41 stevesk 1432:
1.20 markus 1433: /* Use a suitable default if we're passed a nil list. */
1434: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1435: authlist = options.preferred_authentications;
1.20 markus 1436:
1.53 markus 1437: if (supported == NULL || strcmp(authlist, supported) != 0) {
1438: debug3("start over, passed a different list %s", authlist);
1439: if (supported != NULL)
1440: xfree(supported);
1441: supported = xstrdup(authlist);
1442: preferred = options.preferred_authentications;
1443: debug3("preferred %s", preferred);
1444: current = NULL;
1445: } else if (current != NULL && authmethod_is_enabled(current))
1446: return current;
1.20 markus 1447:
1.53 markus 1448: for (;;) {
1449: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1450: debug("No more authentication methods to try.");
1.53 markus 1451: current = NULL;
1452: return NULL;
1453: }
1454: preferred += next;
1.23 markus 1455: debug3("authmethod_lookup %s", name);
1.53 markus 1456: debug3("remaining preferred: %s", preferred);
1457: if ((current = authmethod_lookup(name)) != NULL &&
1458: authmethod_is_enabled(current)) {
1.23 markus 1459: debug3("authmethod_is_enabled %s", name);
1.109 markus 1460: debug("Next authentication method: %s", name);
1.53 markus 1461: return current;
1.23 markus 1462: }
1.1 markus 1463: }
1.53 markus 1464: }
1.1 markus 1465:
1.79 stevesk 1466: static char *
1.53 markus 1467: authmethods_get(void)
1468: {
1469: Authmethod *method = NULL;
1.93 markus 1470: Buffer b;
1471: char *list;
1.27 provos 1472:
1.93 markus 1473: buffer_init(&b);
1.53 markus 1474: for (method = authmethods; method->name != NULL; method++) {
1475: if (authmethod_is_enabled(method)) {
1.93 markus 1476: if (buffer_len(&b) > 0)
1477: buffer_append(&b, ",", 1);
1478: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1479: }
1480: }
1.93 markus 1481: buffer_append(&b, "\0", 1);
1482: list = xstrdup(buffer_ptr(&b));
1483: buffer_free(&b);
1484: return list;
1.1 markus 1485: }
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