Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.136
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"
1.136 ! henning 26: RCSID("$OpenBSD: sshconnect2.c,v 1.135 2004/03/05 10:53:58 markus 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"
44: #include "readpass.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] =
1.107 markus 102: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
1.22 provos 103: } else {
1.47 markus 104: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.107 markus 105: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,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;
121: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.61 markus 122: kex->client_version_string=client_version_string;
123: kex->server_version_string=server_version_string;
1.75 markus 124: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 125:
126: xxx_kex = kex;
1.22 provos 127:
1.66 markus 128: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 129:
130: session_id2 = kex->session_id;
131: session_id2_len = kex->session_id_len;
1.22 provos 132:
133: #ifdef DEBUG_KEXDH
134: /* send 1st encrypted/maced/compressed message */
135: packet_start(SSH2_MSG_IGNORE);
136: packet_put_cstring("markus");
137: packet_send();
138: packet_write_wait();
139: #endif
1.1 markus 140: }
1.11 markus 141:
1.1 markus 142: /*
143: * Authenticate user
144: */
1.20 markus 145:
146: typedef struct Authctxt Authctxt;
147: typedef struct Authmethod Authmethod;
1.117 markus 148: typedef struct identity Identity;
149: typedef struct idlist Idlist;
1.20 markus 150:
1.117 markus 151: struct identity {
152: TAILQ_ENTRY(identity) next;
153: AuthenticationConnection *ac; /* set if agent supports key */
154: Key *key; /* public/private key */
155: char *filename; /* comment for agent-only keys */
156: int tried;
157: int isprivate; /* key points to the private key */
158: };
159: TAILQ_HEAD(idlist, identity);
1.20 markus 160:
161: struct Authctxt {
162: const char *server_user;
1.68 markus 163: const char *local_user;
1.20 markus 164: const char *host;
165: const char *service;
1.23 markus 166: Authmethod *method;
1.20 markus 167: int success;
1.51 markus 168: char *authlist;
1.68 markus 169: /* pubkey */
1.117 markus 170: Idlist keys;
1.68 markus 171: AuthenticationConnection *agent;
172: /* hostbased */
1.100 markus 173: Sensitive *sensitive;
1.82 markus 174: /* kbd-interactive */
175: int info_req_seen;
1.121 markus 176: /* generic */
177: void *methoddata;
1.20 markus 178: };
179: struct Authmethod {
180: char *name; /* string to compare against server's list */
181: int (*userauth)(Authctxt *authctxt);
182: int *enabled; /* flag in option struct that enables method */
183: int *batch_flag; /* flag in option struct that disables method */
184: };
185:
1.92 markus 186: void input_userauth_success(int, u_int32_t, void *);
187: void input_userauth_failure(int, u_int32_t, void *);
188: void input_userauth_banner(int, u_int32_t, void *);
189: void input_userauth_error(int, u_int32_t, void *);
190: void input_userauth_info_req(int, u_int32_t, void *);
191: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 192: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 193:
194: int userauth_none(Authctxt *);
195: int userauth_pubkey(Authctxt *);
196: int userauth_passwd(Authctxt *);
197: int userauth_kbdint(Authctxt *);
198: int userauth_hostbased(Authctxt *);
1.118 markus 199: int userauth_kerberos(Authctxt *);
1.20 markus 200:
1.121 markus 201: #ifdef GSSAPI
202: int userauth_gssapi(Authctxt *authctxt);
203: void input_gssapi_response(int type, u_int32_t, void *);
204: void input_gssapi_token(int type, u_int32_t, void *);
205: void input_gssapi_hash(int type, u_int32_t, void *);
206: void input_gssapi_error(int, u_int32_t, void *);
207: void input_gssapi_errtok(int, u_int32_t, void *);
208: #endif
209:
1.86 itojun 210: void userauth(Authctxt *, char *);
1.51 markus 211:
1.117 markus 212: static int sign_and_send_pubkey(Authctxt *, Identity *);
213: static void pubkey_prepare(Authctxt *);
214: static void pubkey_cleanup(Authctxt *);
215: static Key *load_identity_file(char *);
1.76 itojun 216:
217: static Authmethod *authmethod_get(char *authlist);
218: static Authmethod *authmethod_lookup(const char *name);
219: static char *authmethods_get(void);
1.20 markus 220:
221: Authmethod authmethods[] = {
1.121 markus 222: #ifdef GSSAPI
1.132 markus 223: {"gssapi-with-mic",
1.121 markus 224: userauth_gssapi,
225: &options.gss_authentication,
226: NULL},
227: #endif
1.81 markus 228: {"hostbased",
229: userauth_hostbased,
230: &options.hostbased_authentication,
231: NULL},
1.20 markus 232: {"publickey",
233: userauth_pubkey,
1.28 markus 234: &options.pubkey_authentication,
1.20 markus 235: NULL},
1.81 markus 236: {"keyboard-interactive",
237: userauth_kbdint,
238: &options.kbd_interactive_authentication,
239: &options.batch_mode},
1.20 markus 240: {"password",
241: userauth_passwd,
242: &options.password_authentication,
1.23 markus 243: &options.batch_mode},
244: {"none",
245: userauth_none,
246: NULL,
247: NULL},
1.20 markus 248: {NULL, NULL, NULL, NULL}
249: };
250:
251: void
1.68 markus 252: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 253: Sensitive *sensitive)
1.20 markus 254: {
255: Authctxt authctxt;
256: int type;
1.39 markus 257:
1.73 markus 258: if (options.challenge_response_authentication)
1.39 markus 259: options.kbd_interactive_authentication = 1;
1.20 markus 260:
261: packet_start(SSH2_MSG_SERVICE_REQUEST);
262: packet_put_cstring("ssh-userauth");
263: packet_send();
1.108 markus 264: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 265: packet_write_wait();
1.91 markus 266: type = packet_read();
1.108 markus 267: if (type != SSH2_MSG_SERVICE_ACCEPT)
268: fatal("Server denied authentication request: %d", type);
1.20 markus 269: if (packet_remaining() > 0) {
1.91 markus 270: char *reply = packet_get_string(NULL);
1.108 markus 271: debug2("service_accept: %s", reply);
1.20 markus 272: xfree(reply);
273: } else {
1.109 markus 274: debug2("buggy server: service_accept w/o service");
1.20 markus 275: }
1.90 markus 276: packet_check_eom();
1.108 markus 277: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 278:
1.53 markus 279: if (options.preferred_authentications == NULL)
280: options.preferred_authentications = authmethods_get();
281:
1.20 markus 282: /* setup authentication context */
1.82 markus 283: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 284: pubkey_prepare(&authctxt);
1.20 markus 285: authctxt.server_user = server_user;
1.68 markus 286: authctxt.local_user = local_user;
1.20 markus 287: authctxt.host = host;
288: authctxt.service = "ssh-connection"; /* service name */
289: authctxt.success = 0;
1.23 markus 290: authctxt.method = authmethod_lookup("none");
1.51 markus 291: authctxt.authlist = NULL;
1.121 markus 292: authctxt.methoddata = NULL;
1.100 markus 293: authctxt.sensitive = sensitive;
1.82 markus 294: authctxt.info_req_seen = 0;
1.23 markus 295: if (authctxt.method == NULL)
296: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 297:
298: /* initial userauth request */
1.23 markus 299: userauth_none(&authctxt);
1.20 markus 300:
1.65 markus 301: dispatch_init(&input_userauth_error);
1.20 markus 302: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
303: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 304: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 305: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
306:
1.117 markus 307: pubkey_cleanup(&authctxt);
1.119 markus 308: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
309:
1.109 markus 310: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 311: }
1.119 markus 312:
1.20 markus 313: void
1.51 markus 314: userauth(Authctxt *authctxt, char *authlist)
315: {
1.121 markus 316: if (authctxt->methoddata) {
317: xfree(authctxt->methoddata);
318: authctxt->methoddata = NULL;
319: }
1.51 markus 320: if (authlist == NULL) {
321: authlist = authctxt->authlist;
322: } else {
323: if (authctxt->authlist)
324: xfree(authctxt->authlist);
325: authctxt->authlist = authlist;
326: }
327: for (;;) {
328: Authmethod *method = authmethod_get(authlist);
329: if (method == NULL)
330: fatal("Permission denied (%s).", authlist);
331: authctxt->method = method;
1.119 markus 332:
333: /* reset the per method handler */
334: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
335: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
336:
337: /* and try new method */
1.51 markus 338: if (method->userauth(authctxt) != 0) {
339: debug2("we sent a %s packet, wait for reply", method->name);
340: break;
341: } else {
342: debug2("we did not send a packet, disable method");
343: method->enabled = NULL;
344: }
345: }
346: }
1.105 deraadt 347:
1.51 markus 348: void
1.92 markus 349: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 350: {
1.35 markus 351: fatal("input_userauth_error: bad message during authentication: "
352: "type %d", type);
353: }
1.105 deraadt 354:
1.35 markus 355: void
1.92 markus 356: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 357: {
358: char *msg, *lang;
1.126 deraadt 359:
1.35 markus 360: debug3("input_userauth_banner");
361: msg = packet_get_string(NULL);
362: lang = packet_get_string(NULL);
1.125 dtucker 363: if (options.log_level > SYSLOG_LEVEL_QUIET)
364: fprintf(stderr, "%s", msg);
1.35 markus 365: xfree(msg);
366: xfree(lang);
1.20 markus 367: }
1.105 deraadt 368:
1.20 markus 369: void
1.92 markus 370: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 371: {
372: Authctxt *authctxt = ctxt;
373: if (authctxt == NULL)
374: fatal("input_userauth_success: no authentication context");
1.126 deraadt 375: if (authctxt->authlist) {
1.51 markus 376: xfree(authctxt->authlist);
1.126 deraadt 377: authctxt->authlist = NULL;
378: }
379: if (authctxt->methoddata) {
1.121 markus 380: xfree(authctxt->methoddata);
1.126 deraadt 381: authctxt->methoddata = NULL;
382: }
1.20 markus 383: authctxt->success = 1; /* break out */
384: }
1.105 deraadt 385:
1.20 markus 386: void
1.92 markus 387: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 388: {
389: Authctxt *authctxt = ctxt;
390: char *authlist = NULL;
391: int partial;
392:
393: if (authctxt == NULL)
394: fatal("input_userauth_failure: no authentication context");
395:
1.23 markus 396: authlist = packet_get_string(NULL);
1.20 markus 397: partial = packet_get_char();
1.90 markus 398: packet_check_eom();
1.20 markus 399:
400: if (partial != 0)
1.116 itojun 401: logit("Authenticated with partial success.");
1.109 markus 402: debug("Authentications that can continue: %s", authlist);
1.20 markus 403:
1.51 markus 404: userauth(authctxt, authlist);
405: }
406: void
1.92 markus 407: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 408: {
409: Authctxt *authctxt = ctxt;
410: Key *key = NULL;
1.117 markus 411: Identity *id = NULL;
1.51 markus 412: Buffer b;
1.96 markus 413: int pktype, sent = 0;
414: u_int alen, blen;
415: char *pkalg, *fp;
416: u_char *pkblob;
1.51 markus 417:
418: if (authctxt == NULL)
419: fatal("input_userauth_pk_ok: no authentication context");
420: if (datafellows & SSH_BUG_PKOK) {
421: /* this is similar to SSH_BUG_PKAUTH */
422: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
423: pkblob = packet_get_string(&blen);
424: buffer_init(&b);
425: buffer_append(&b, pkblob, blen);
426: pkalg = buffer_get_string(&b, &alen);
427: buffer_free(&b);
428: } else {
429: pkalg = packet_get_string(&alen);
430: pkblob = packet_get_string(&blen);
431: }
1.90 markus 432: packet_check_eom();
1.51 markus 433:
1.117 markus 434: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 435:
1.117 markus 436: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
437: debug("unknown pkalg %s", pkalg);
438: goto done;
439: }
440: if ((key = key_from_blob(pkblob, blen)) == NULL) {
441: debug("no key from blob. pkalg %s", pkalg);
442: goto done;
443: }
444: if (key->type != pktype) {
445: error("input_userauth_pk_ok: type mismatch "
446: "for decoded key (received %d, expected %d)",
447: key->type, pktype);
448: goto done;
449: }
450: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
451: debug2("input_userauth_pk_ok: fp %s", fp);
452: xfree(fp);
453:
1.127 markus 454: /*
455: * search keys in the reverse order, because last candidate has been
456: * moved to the end of the queue. this also avoids confusion by
457: * duplicate keys
458: */
1.136 ! henning 459: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 460: if (key_equal(key, id->key)) {
461: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 462: break;
463: }
1.117 markus 464: }
465: done:
1.51 markus 466: if (key != NULL)
467: key_free(key);
468: xfree(pkalg);
469: xfree(pkblob);
470:
1.106 deraadt 471: /* try another method if we did not send a packet */
1.51 markus 472: if (sent == 0)
473: userauth(authctxt, NULL);
1.20 markus 474: }
1.121 markus 475:
476: #ifdef GSSAPI
1.133 djm 477: int
1.121 markus 478: userauth_gssapi(Authctxt *authctxt)
479: {
480: Gssctxt *gssctxt = NULL;
1.128 avsm 481: static gss_OID_set gss_supported = NULL;
1.121 markus 482: static int mech = 0;
483: OM_uint32 min;
484: int ok = 0;
485:
486: /* Try one GSSAPI method at a time, rather than sending them all at
487: * once. */
488:
1.128 avsm 489: if (gss_supported == NULL)
490: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 491:
492: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 493: while (mech < gss_supported->count && !ok) {
1.121 markus 494: if (gssctxt)
495: ssh_gssapi_delete_ctx(&gssctxt);
496: ssh_gssapi_build_ctx(&gssctxt);
1.128 avsm 497: ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
1.121 markus 498:
499: /* My DER encoding requires length<128 */
1.128 avsm 500: if (gss_supported->elements[mech].length < 128 &&
1.121 markus 501: !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
502: authctxt->host))) {
503: ok = 1; /* Mechanism works */
504: } else {
505: mech++;
506: }
507: }
508:
509: if (!ok) return 0;
510:
511: authctxt->methoddata=(void *)gssctxt;
512:
513: packet_start(SSH2_MSG_USERAUTH_REQUEST);
514: packet_put_cstring(authctxt->server_user);
515: packet_put_cstring(authctxt->service);
516: packet_put_cstring(authctxt->method->name);
517:
518: packet_put_int(1);
519:
1.129 markus 520: packet_put_int((gss_supported->elements[mech].length) + 2);
521: packet_put_char(SSH_GSS_OIDTYPE);
522: packet_put_char(gss_supported->elements[mech].length);
523: packet_put_raw(gss_supported->elements[mech].elements,
524: gss_supported->elements[mech].length);
1.121 markus 525:
526: packet_send();
527:
528: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
529: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
530: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
531: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
532:
533: mech++; /* Move along to next candidate */
534:
535: return 1;
536: }
537:
1.130 markus 538: static OM_uint32
539: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
540: {
541: Authctxt *authctxt = ctxt;
542: Gssctxt *gssctxt = authctxt->methoddata;
543: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.132 markus 544: gss_buffer_desc gssbuf, mic;
545: OM_uint32 status, ms, flags;
546: Buffer b;
1.133 djm 547:
1.130 markus 548: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 549: recv_tok, &send_tok, &flags);
1.130 markus 550:
551: if (send_tok.length > 0) {
552: if (GSS_ERROR(status))
553: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
554: else
555: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 556:
1.130 markus 557: packet_put_string(send_tok.value, send_tok.length);
558: packet_send();
559: gss_release_buffer(&ms, &send_tok);
560: }
1.133 djm 561:
1.130 markus 562: if (status == GSS_S_COMPLETE) {
1.132 markus 563: /* send either complete or MIC, depending on mechanism */
564: if (!(flags & GSS_C_INTEG_FLAG)) {
565: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
566: packet_send();
567: } else {
568: ssh_gssapi_buildmic(&b, authctxt->server_user,
569: authctxt->service, "gssapi-with-mic");
570:
571: gssbuf.value = buffer_ptr(&b);
572: gssbuf.length = buffer_len(&b);
1.133 djm 573:
1.132 markus 574: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 575:
1.132 markus 576: if (!GSS_ERROR(status)) {
577: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
578: packet_put_string(mic.value, mic.length);
1.133 djm 579:
1.132 markus 580: packet_send();
581: }
1.133 djm 582:
1.132 markus 583: buffer_free(&b);
584: gss_release_buffer(&ms, &mic);
1.133 djm 585: }
1.130 markus 586: }
1.133 djm 587:
1.130 markus 588: return status;
589: }
590:
1.121 markus 591: void
592: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
593: {
594: Authctxt *authctxt = ctxt;
595: Gssctxt *gssctxt;
596: int oidlen;
597: char *oidv;
598:
599: if (authctxt == NULL)
600: fatal("input_gssapi_response: no authentication context");
601: gssctxt = authctxt->methoddata;
602:
603: /* Setup our OID */
604: oidv = packet_get_string(&oidlen);
605:
1.129 markus 606: if (oidlen <= 2 ||
607: oidv[0] != SSH_GSS_OIDTYPE ||
608: oidv[1] != oidlen - 2) {
1.130 markus 609: xfree(oidv);
1.129 markus 610: debug("Badly encoded mechanism OID received");
611: userauth(authctxt, NULL);
612: return;
1.121 markus 613: }
1.129 markus 614:
615: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
616: fatal("Server returned different OID than expected");
1.121 markus 617:
618: packet_check_eom();
619:
620: xfree(oidv);
621:
1.130 markus 622: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 623: /* Start again with next method on list */
624: debug("Trying to start again");
625: userauth(authctxt, NULL);
626: return;
627: }
628: }
629:
630: void
631: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
632: {
633: Authctxt *authctxt = ctxt;
634: gss_buffer_desc recv_tok;
1.130 markus 635: OM_uint32 status;
1.121 markus 636: u_int slen;
637:
638: if (authctxt == NULL)
639: fatal("input_gssapi_response: no authentication context");
640:
641: recv_tok.value = packet_get_string(&slen);
642: recv_tok.length = slen; /* safe typecast */
643:
644: packet_check_eom();
645:
1.130 markus 646: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 647:
648: xfree(recv_tok.value);
649:
650: if (GSS_ERROR(status)) {
651: /* Start again with the next method in the list */
652: userauth(authctxt, NULL);
653: return;
654: }
655: }
656:
657: void
658: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
659: {
660: Authctxt *authctxt = ctxt;
661: Gssctxt *gssctxt;
662: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
663: gss_buffer_desc recv_tok;
664: OM_uint32 status, ms;
1.123 deraadt 665: u_int len;
1.121 markus 666:
667: if (authctxt == NULL)
668: fatal("input_gssapi_response: no authentication context");
669: gssctxt = authctxt->methoddata;
670:
1.123 deraadt 671: recv_tok.value = packet_get_string(&len);
672: recv_tok.length = len;
1.121 markus 673:
674: packet_check_eom();
675:
676: /* Stick it into GSSAPI and see what it says */
677: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
678: &recv_tok, &send_tok, NULL);
679:
680: xfree(recv_tok.value);
681: gss_release_buffer(&ms, &send_tok);
682:
683: /* Server will be returning a failed packet after this one */
684: }
685:
686: void
687: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
688: {
689: OM_uint32 maj, min;
690: char *msg;
691: char *lang;
692:
693: maj=packet_get_int();
694: min=packet_get_int();
695: msg=packet_get_string(NULL);
696: lang=packet_get_string(NULL);
697:
698: packet_check_eom();
699:
700: debug("Server GSSAPI Error:\n%s\n", msg);
701: xfree(msg);
702: xfree(lang);
703: }
704: #endif /* GSSAPI */
1.20 markus 705:
1.1 markus 706: int
1.23 markus 707: userauth_none(Authctxt *authctxt)
708: {
709: /* initial userauth request */
710: packet_start(SSH2_MSG_USERAUTH_REQUEST);
711: packet_put_cstring(authctxt->server_user);
712: packet_put_cstring(authctxt->service);
713: packet_put_cstring(authctxt->method->name);
714: packet_send();
715: return 1;
716: }
717:
718: int
1.20 markus 719: userauth_passwd(Authctxt *authctxt)
1.1 markus 720: {
1.6 markus 721: static int attempt = 0;
1.99 markus 722: char prompt[150];
1.1 markus 723: char *password;
1.6 markus 724:
1.13 todd 725: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 726: return 0;
1.13 todd 727:
1.87 deraadt 728: if (attempt != 1)
1.13 todd 729: error("Permission denied, please try again.");
1.1 markus 730:
1.43 itojun 731: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 732: authctxt->server_user, authctxt->host);
1.1 markus 733: password = read_passphrase(prompt, 0);
734: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 735: packet_put_cstring(authctxt->server_user);
736: packet_put_cstring(authctxt->service);
1.23 markus 737: packet_put_cstring(authctxt->method->name);
1.1 markus 738: packet_put_char(0);
1.49 markus 739: packet_put_cstring(password);
1.1 markus 740: memset(password, 0, strlen(password));
741: xfree(password);
1.85 markus 742: packet_add_padding(64);
1.1 markus 743: packet_send();
1.99 markus 744:
1.104 deraadt 745: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 746: &input_userauth_passwd_changereq);
747:
1.1 markus 748: return 1;
749: }
1.99 markus 750: /*
751: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
752: */
753: void
754: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
755: {
756: Authctxt *authctxt = ctxt;
757: char *info, *lang, *password = NULL, *retype = NULL;
758: char prompt[150];
759:
760: debug2("input_userauth_passwd_changereq");
761:
762: if (authctxt == NULL)
763: fatal("input_userauth_passwd_changereq: "
764: "no authentication context");
765:
766: info = packet_get_string(NULL);
767: lang = packet_get_string(NULL);
768: if (strlen(info) > 0)
1.116 itojun 769: logit("%s", info);
1.99 markus 770: xfree(info);
771: xfree(lang);
772: packet_start(SSH2_MSG_USERAUTH_REQUEST);
773: packet_put_cstring(authctxt->server_user);
774: packet_put_cstring(authctxt->service);
775: packet_put_cstring(authctxt->method->name);
776: packet_put_char(1); /* additional info */
1.104 deraadt 777: snprintf(prompt, sizeof(prompt),
1.99 markus 778: "Enter %.30s@%.128s's old password: ",
779: authctxt->server_user, authctxt->host);
780: password = read_passphrase(prompt, 0);
781: packet_put_cstring(password);
782: memset(password, 0, strlen(password));
783: xfree(password);
784: password = NULL;
785: while (password == NULL) {
1.104 deraadt 786: snprintf(prompt, sizeof(prompt),
1.99 markus 787: "Enter %.30s@%.128s's new password: ",
788: authctxt->server_user, authctxt->host);
789: password = read_passphrase(prompt, RP_ALLOW_EOF);
790: if (password == NULL) {
791: /* bail out */
792: return;
793: }
1.104 deraadt 794: snprintf(prompt, sizeof(prompt),
1.99 markus 795: "Retype %.30s@%.128s's new password: ",
796: authctxt->server_user, authctxt->host);
797: retype = read_passphrase(prompt, 0);
798: if (strcmp(password, retype) != 0) {
799: memset(password, 0, strlen(password));
800: xfree(password);
1.116 itojun 801: logit("Mismatch; try again, EOF to quit.");
1.99 markus 802: password = NULL;
803: }
804: memset(retype, 0, strlen(retype));
805: xfree(retype);
806: }
807: packet_put_cstring(password);
808: memset(password, 0, strlen(password));
809: xfree(password);
810: packet_add_padding(64);
811: packet_send();
1.104 deraadt 812:
813: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 814: &input_userauth_passwd_changereq);
1.117 markus 815: }
816:
817: static int
818: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
819: u_char *data, u_int datalen)
820: {
821: Key *prv;
822: int ret;
1.99 markus 823:
1.117 markus 824: /* the agent supports this key */
825: if (id->ac)
826: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
827: data, datalen));
828: /*
829: * we have already loaded the private key or
830: * the private key is stored in external hardware
831: */
832: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
833: return (key_sign(id->key, sigp, lenp, data, datalen));
834: /* load the private key from the file */
835: if ((prv = load_identity_file(id->filename)) == NULL)
836: return (-1);
837: ret = key_sign(prv, sigp, lenp, data, datalen);
838: key_free(prv);
839: return (ret);
1.51 markus 840: }
841:
1.76 itojun 842: static int
1.117 markus 843: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 844: {
845: Buffer b;
1.32 markus 846: u_char *blob, *signature;
1.96 markus 847: u_int bloblen, slen;
1.120 markus 848: u_int skip = 0;
1.17 markus 849: int ret = -1;
1.23 markus 850: int have_sig = 1;
1.1 markus 851:
1.30 markus 852: debug3("sign_and_send_pubkey");
1.51 markus 853:
1.117 markus 854: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 855: /* we cannot handle this key */
1.30 markus 856: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 857: return 0;
858: }
1.1 markus 859: /* data to be signed */
860: buffer_init(&b);
1.26 markus 861: if (datafellows & SSH_OLD_SESSIONID) {
862: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 863: skip = session_id2_len;
1.26 markus 864: } else {
1.14 markus 865: buffer_put_string(&b, session_id2, session_id2_len);
866: skip = buffer_len(&b);
867: }
1.1 markus 868: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 869: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 870: buffer_put_cstring(&b,
1.30 markus 871: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 872: "ssh-userauth" :
1.20 markus 873: authctxt->service);
1.30 markus 874: if (datafellows & SSH_BUG_PKAUTH) {
875: buffer_put_char(&b, have_sig);
876: } else {
877: buffer_put_cstring(&b, authctxt->method->name);
878: buffer_put_char(&b, have_sig);
1.117 markus 879: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 880: }
1.1 markus 881: buffer_put_string(&b, blob, bloblen);
882:
883: /* generate signature */
1.117 markus 884: ret = identity_sign(id, &signature, &slen,
1.51 markus 885: buffer_ptr(&b), buffer_len(&b));
1.17 markus 886: if (ret == -1) {
887: xfree(blob);
888: buffer_free(&b);
889: return 0;
890: }
1.28 markus 891: #ifdef DEBUG_PK
1.1 markus 892: buffer_dump(&b);
893: #endif
1.30 markus 894: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 895: buffer_clear(&b);
896: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 897: skip = session_id2_len;
1.10 markus 898: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 899: buffer_put_cstring(&b, authctxt->server_user);
900: buffer_put_cstring(&b, authctxt->service);
1.23 markus 901: buffer_put_cstring(&b, authctxt->method->name);
902: buffer_put_char(&b, have_sig);
1.30 markus 903: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 904: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 905: buffer_put_string(&b, blob, bloblen);
906: }
907: xfree(blob);
1.51 markus 908:
1.1 markus 909: /* append signature */
910: buffer_put_string(&b, signature, slen);
911: xfree(signature);
912:
913: /* skip session id and packet type */
1.14 markus 914: if (buffer_len(&b) < skip + 1)
1.20 markus 915: fatal("userauth_pubkey: internal error");
1.14 markus 916: buffer_consume(&b, skip + 1);
1.1 markus 917:
918: /* put remaining data from buffer into packet */
919: packet_start(SSH2_MSG_USERAUTH_REQUEST);
920: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
921: buffer_free(&b);
922: packet_send();
1.17 markus 923:
924: return 1;
1.16 markus 925: }
926:
1.76 itojun 927: static int
1.117 markus 928: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 929: {
1.51 markus 930: u_char *blob;
1.97 markus 931: u_int bloblen, have_sig = 0;
1.20 markus 932:
1.51 markus 933: debug3("send_pubkey_test");
1.16 markus 934:
1.117 markus 935: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 936: /* we cannot handle this key */
937: debug3("send_pubkey_test: cannot handle key");
1.16 markus 938: return 0;
939: }
1.51 markus 940: /* register callback for USERAUTH_PK_OK message */
941: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
942:
943: packet_start(SSH2_MSG_USERAUTH_REQUEST);
944: packet_put_cstring(authctxt->server_user);
945: packet_put_cstring(authctxt->service);
946: packet_put_cstring(authctxt->method->name);
947: packet_put_char(have_sig);
948: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 949: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 950: packet_put_string(blob, bloblen);
951: xfree(blob);
952: packet_send();
953: return 1;
954: }
955:
1.76 itojun 956: static Key *
1.51 markus 957: load_identity_file(char *filename)
958: {
959: Key *private;
960: char prompt[300], *passphrase;
1.56 markus 961: int quit, i;
1.52 markus 962: struct stat st;
1.16 markus 963:
1.52 markus 964: if (stat(filename, &st) < 0) {
965: debug3("no such identity: %s", filename);
966: return NULL;
967: }
1.56 markus 968: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
969: if (private == NULL) {
970: if (options.batch_mode)
1.51 markus 971: return NULL;
1.16 markus 972: snprintf(prompt, sizeof prompt,
1.88 deraadt 973: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 974: for (i = 0; i < options.number_of_password_prompts; i++) {
975: passphrase = read_passphrase(prompt, 0);
976: if (strcmp(passphrase, "") != 0) {
1.56 markus 977: private = key_load_private_type(KEY_UNSPEC, filename,
978: passphrase, NULL);
1.51 markus 979: quit = 0;
1.20 markus 980: } else {
981: debug2("no passphrase given, try next key");
1.51 markus 982: quit = 1;
1.20 markus 983: }
984: memset(passphrase, 0, strlen(passphrase));
985: xfree(passphrase);
1.56 markus 986: if (private != NULL || quit)
1.20 markus 987: break;
988: debug2("bad passphrase given, try again...");
1.16 markus 989: }
990: }
1.51 markus 991: return private;
992: }
993:
1.117 markus 994: /*
995: * try keys in the following order:
996: * 1. agent keys that are found in the config file
997: * 2. other agent keys
998: * 3. keys that are only listed in the config file
999: */
1000: static void
1001: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1002: {
1.117 markus 1003: Identity *id;
1004: Idlist agent, files, *preferred;
1005: Key *key;
1006: AuthenticationConnection *ac;
1007: char *comment;
1008: int i, found;
1.51 markus 1009:
1.117 markus 1010: TAILQ_INIT(&agent); /* keys from the agent */
1011: TAILQ_INIT(&files); /* keys from the config file */
1012: preferred = &authctxt->keys;
1013: TAILQ_INIT(preferred); /* preferred order of keys */
1014:
1015: /* list of keys stored in the filesystem */
1016: for (i = 0; i < options.num_identity_files; i++) {
1017: key = options.identity_keys[i];
1018: if (key && key->type == KEY_RSA1)
1019: continue;
1020: options.identity_keys[i] = NULL;
1021: id = xmalloc(sizeof(*id));
1022: memset(id, 0, sizeof(*id));
1023: id->key = key;
1024: id->filename = xstrdup(options.identity_files[i]);
1025: TAILQ_INSERT_TAIL(&files, id, next);
1026: }
1027: /* list of keys supported by the agent */
1028: if ((ac = ssh_get_authentication_connection())) {
1029: for (key = ssh_get_first_identity(ac, &comment, 2);
1030: key != NULL;
1031: key = ssh_get_next_identity(ac, &comment, 2)) {
1032: found = 0;
1033: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1034: /* agent keys from the config file are preferred */
1.117 markus 1035: if (key_equal(key, id->key)) {
1036: key_free(key);
1037: xfree(comment);
1038: TAILQ_REMOVE(&files, id, next);
1039: TAILQ_INSERT_TAIL(preferred, id, next);
1040: id->ac = ac;
1041: found = 1;
1042: break;
1043: }
1044: }
1.135 markus 1045: if (!found && !options.identities_only) {
1.117 markus 1046: id = xmalloc(sizeof(*id));
1047: memset(id, 0, sizeof(*id));
1048: id->key = key;
1049: id->filename = comment;
1050: id->ac = ac;
1051: TAILQ_INSERT_TAIL(&agent, id, next);
1052: }
1053: }
1054: /* append remaining agent keys */
1055: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1056: TAILQ_REMOVE(&agent, id, next);
1057: TAILQ_INSERT_TAIL(preferred, id, next);
1058: }
1059: authctxt->agent = ac;
1060: }
1061: /* append remaining keys from the config file */
1062: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1063: TAILQ_REMOVE(&files, id, next);
1064: TAILQ_INSERT_TAIL(preferred, id, next);
1065: }
1066: TAILQ_FOREACH(id, preferred, next) {
1067: debug2("key: %s (%p)", id->filename, id->key);
1068: }
1.17 markus 1069: }
1070:
1.117 markus 1071: static void
1072: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1073: {
1.117 markus 1074: Identity *id;
1.51 markus 1075:
1.117 markus 1076: if (authctxt->agent != NULL)
1077: ssh_close_authentication_connection(authctxt->agent);
1078: for (id = TAILQ_FIRST(&authctxt->keys); id;
1079: id = TAILQ_FIRST(&authctxt->keys)) {
1080: TAILQ_REMOVE(&authctxt->keys, id, next);
1081: if (id->key)
1082: key_free(id->key);
1083: if (id->filename)
1084: xfree(id->filename);
1085: xfree(id);
1086: }
1.1 markus 1087: }
1088:
1.20 markus 1089: int
1090: userauth_pubkey(Authctxt *authctxt)
1091: {
1.117 markus 1092: Identity *id;
1.20 markus 1093: int sent = 0;
1094:
1.117 markus 1095: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1096: if (id->tried++)
1097: return (0);
1.127 markus 1098: /* move key to the end of the queue */
1.117 markus 1099: TAILQ_REMOVE(&authctxt->keys, id, next);
1100: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1101: /*
1102: * send a test message if we have the public key. for
1103: * encrypted keys we cannot do this and have to load the
1104: * private key instead
1105: */
1106: if (id->key && id->key->type != KEY_RSA1) {
1107: debug("Offering public key: %s", id->filename);
1108: sent = send_pubkey_test(authctxt, id);
1109: } else if (id->key == NULL) {
1110: debug("Trying private key: %s", id->filename);
1111: id->key = load_identity_file(id->filename);
1112: if (id->key != NULL) {
1113: id->isprivate = 1;
1114: sent = sign_and_send_pubkey(authctxt, id);
1115: key_free(id->key);
1116: id->key = NULL;
1.51 markus 1117: }
1118: }
1.117 markus 1119: if (sent)
1120: return (sent);
1.28 markus 1121: }
1.117 markus 1122: return (0);
1.20 markus 1123: }
1124:
1.23 markus 1125: /*
1126: * Send userauth request message specifying keyboard-interactive method.
1127: */
1128: int
1129: userauth_kbdint(Authctxt *authctxt)
1130: {
1131: static int attempt = 0;
1132:
1133: if (attempt++ >= options.number_of_password_prompts)
1134: return 0;
1.82 markus 1135: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1136: if (attempt > 1 && !authctxt->info_req_seen) {
1137: debug3("userauth_kbdint: disable: no info_req_seen");
1138: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1139: return 0;
1140: }
1.23 markus 1141:
1142: debug2("userauth_kbdint");
1143: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1144: packet_put_cstring(authctxt->server_user);
1145: packet_put_cstring(authctxt->service);
1146: packet_put_cstring(authctxt->method->name);
1147: packet_put_cstring(""); /* lang */
1148: packet_put_cstring(options.kbd_interactive_devices ?
1149: options.kbd_interactive_devices : "");
1150: packet_send();
1151:
1152: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1153: return 1;
1154: }
1155:
1156: /*
1.46 markus 1157: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1158: */
1159: void
1.92 markus 1160: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1161: {
1162: Authctxt *authctxt = ctxt;
1.46 markus 1163: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1164: u_int num_prompts, i;
1.23 markus 1165: int echo = 0;
1166:
1167: debug2("input_userauth_info_req");
1168:
1169: if (authctxt == NULL)
1170: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1171:
1172: authctxt->info_req_seen = 1;
1.23 markus 1173:
1174: name = packet_get_string(NULL);
1175: inst = packet_get_string(NULL);
1176: lang = packet_get_string(NULL);
1177: if (strlen(name) > 0)
1.116 itojun 1178: logit("%s", name);
1.23 markus 1179: if (strlen(inst) > 0)
1.116 itojun 1180: logit("%s", inst);
1.46 markus 1181: xfree(name);
1.23 markus 1182: xfree(inst);
1.46 markus 1183: xfree(lang);
1.23 markus 1184:
1185: num_prompts = packet_get_int();
1186: /*
1187: * Begin to build info response packet based on prompts requested.
1188: * We commit to providing the correct number of responses, so if
1189: * further on we run into a problem that prevents this, we have to
1190: * be sure and clean this up and send a correct error response.
1191: */
1192: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1193: packet_put_int(num_prompts);
1194:
1.73 markus 1195: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1196: for (i = 0; i < num_prompts; i++) {
1197: prompt = packet_get_string(NULL);
1198: echo = packet_get_char();
1199:
1.77 markus 1200: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1201:
1.49 markus 1202: packet_put_cstring(response);
1.23 markus 1203: memset(response, 0, strlen(response));
1204: xfree(response);
1205: xfree(prompt);
1206: }
1.90 markus 1207: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1208:
1.85 markus 1209: packet_add_padding(64);
1.23 markus 1210: packet_send();
1.68 markus 1211: }
1212:
1.100 markus 1213: static int
1.105 deraadt 1214: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1215: u_char *data, u_int datalen)
1216: {
1217: Buffer b;
1.101 markus 1218: struct stat st;
1.100 markus 1219: pid_t pid;
1.103 markus 1220: int to[2], from[2], status, version = 2;
1.100 markus 1221:
1.109 markus 1222: debug2("ssh_keysign called");
1.100 markus 1223:
1.101 markus 1224: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1225: error("ssh_keysign: no installed: %s", strerror(errno));
1226: return -1;
1227: }
1.100 markus 1228: if (fflush(stdout) != 0)
1229: error("ssh_keysign: fflush: %s", strerror(errno));
1230: if (pipe(to) < 0) {
1231: error("ssh_keysign: pipe: %s", strerror(errno));
1232: return -1;
1233: }
1234: if (pipe(from) < 0) {
1235: error("ssh_keysign: pipe: %s", strerror(errno));
1236: return -1;
1237: }
1238: if ((pid = fork()) < 0) {
1239: error("ssh_keysign: fork: %s", strerror(errno));
1240: return -1;
1241: }
1242: if (pid == 0) {
1243: seteuid(getuid());
1244: setuid(getuid());
1245: close(from[0]);
1246: if (dup2(from[1], STDOUT_FILENO) < 0)
1247: fatal("ssh_keysign: dup2: %s", strerror(errno));
1248: close(to[1]);
1249: if (dup2(to[0], STDIN_FILENO) < 0)
1250: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1251: close(from[1]);
1252: close(to[0]);
1.102 markus 1253: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1254: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1255: strerror(errno));
1256: }
1257: close(from[1]);
1258: close(to[0]);
1259:
1260: buffer_init(&b);
1.103 markus 1261: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1262: buffer_put_string(&b, data, datalen);
1.131 djm 1263: if (ssh_msg_send(to[1], version, &b) == -1)
1264: fatal("ssh_keysign: couldn't send request");
1.100 markus 1265:
1.110 djm 1266: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1267: error("ssh_keysign: no reply");
1.134 markus 1268: buffer_free(&b);
1.100 markus 1269: return -1;
1270: }
1.101 markus 1271: close(from[0]);
1272: close(to[1]);
1273:
1.103 markus 1274: while (waitpid(pid, &status, 0) < 0)
1275: if (errno != EINTR)
1276: break;
1.101 markus 1277:
1.100 markus 1278: if (buffer_get_char(&b) != version) {
1.101 markus 1279: error("ssh_keysign: bad version");
1.134 markus 1280: buffer_free(&b);
1.100 markus 1281: return -1;
1282: }
1283: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1284: buffer_free(&b);
1.100 markus 1285:
1286: return 0;
1287: }
1288:
1.68 markus 1289: int
1290: userauth_hostbased(Authctxt *authctxt)
1291: {
1292: Key *private = NULL;
1.100 markus 1293: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1294: Buffer b;
1295: u_char *signature, *blob;
1296: char *chost, *pkalg, *p;
1.72 markus 1297: const char *service;
1.68 markus 1298: u_int blen, slen;
1.71 markus 1299: int ok, i, len, found = 0;
1.68 markus 1300:
1301: /* check for a useful key */
1.100 markus 1302: for (i = 0; i < sensitive->nkeys; i++) {
1303: private = sensitive->keys[i];
1.68 markus 1304: if (private && private->type != KEY_RSA1) {
1305: found = 1;
1306: /* we take and free the key */
1.100 markus 1307: sensitive->keys[i] = NULL;
1.68 markus 1308: break;
1309: }
1310: }
1311: if (!found) {
1.109 markus 1312: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1313: return 0;
1314: }
1315: if (key_to_blob(private, &blob, &blen) == 0) {
1316: key_free(private);
1317: return 0;
1318: }
1.84 markus 1319: /* figure out a name for the client host */
1320: p = get_local_name(packet_get_connection_in());
1321: if (p == NULL) {
1322: error("userauth_hostbased: cannot get local ipaddr/name");
1323: key_free(private);
1324: return 0;
1325: }
1326: len = strlen(p) + 2;
1327: chost = xmalloc(len);
1328: strlcpy(chost, p, len);
1329: strlcat(chost, ".", len);
1330: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1331: xfree(p);
1.84 markus 1332:
1.72 markus 1333: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1334: authctxt->service;
1.68 markus 1335: pkalg = xstrdup(key_ssh_name(private));
1336: buffer_init(&b);
1337: /* construct data */
1.72 markus 1338: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1339: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1340: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1341: buffer_put_cstring(&b, service);
1.68 markus 1342: buffer_put_cstring(&b, authctxt->method->name);
1343: buffer_put_cstring(&b, pkalg);
1344: buffer_put_string(&b, blob, blen);
1345: buffer_put_cstring(&b, chost);
1346: buffer_put_cstring(&b, authctxt->local_user);
1347: #ifdef DEBUG_PK
1348: buffer_dump(&b);
1349: #endif
1.100 markus 1350: if (sensitive->external_keysign)
1351: ok = ssh_keysign(private, &signature, &slen,
1352: buffer_ptr(&b), buffer_len(&b));
1353: else
1354: ok = key_sign(private, &signature, &slen,
1355: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1356: key_free(private);
1357: buffer_free(&b);
1358: if (ok != 0) {
1359: error("key_sign failed");
1360: xfree(chost);
1361: xfree(pkalg);
1362: return 0;
1363: }
1364: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1365: packet_put_cstring(authctxt->server_user);
1366: packet_put_cstring(authctxt->service);
1367: packet_put_cstring(authctxt->method->name);
1368: packet_put_cstring(pkalg);
1369: packet_put_string(blob, blen);
1370: packet_put_cstring(chost);
1371: packet_put_cstring(authctxt->local_user);
1372: packet_put_string(signature, slen);
1373: memset(signature, 's', slen);
1374: xfree(signature);
1375: xfree(chost);
1376: xfree(pkalg);
1377:
1378: packet_send();
1379: return 1;
1.23 markus 1380: }
1.20 markus 1381:
1382: /* find auth method */
1383:
1384: /*
1385: * given auth method name, if configurable options permit this method fill
1386: * in auth_ident field and return true, otherwise return false.
1387: */
1.76 itojun 1388: static int
1.20 markus 1389: authmethod_is_enabled(Authmethod *method)
1390: {
1391: if (method == NULL)
1392: return 0;
1393: /* return false if options indicate this method is disabled */
1394: if (method->enabled == NULL || *method->enabled == 0)
1395: return 0;
1396: /* return false if batch mode is enabled but method needs interactive mode */
1397: if (method->batch_flag != NULL && *method->batch_flag != 0)
1398: return 0;
1399: return 1;
1400: }
1401:
1.76 itojun 1402: static Authmethod *
1.20 markus 1403: authmethod_lookup(const char *name)
1.1 markus 1404: {
1.20 markus 1405: Authmethod *method = NULL;
1406: if (name != NULL)
1407: for (method = authmethods; method->name != NULL; method++)
1408: if (strcmp(name, method->name) == 0)
1409: return method;
1410: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1411: return NULL;
1412: }
1.1 markus 1413:
1.53 markus 1414: /* XXX internal state */
1415: static Authmethod *current = NULL;
1416: static char *supported = NULL;
1417: static char *preferred = NULL;
1.105 deraadt 1418:
1.20 markus 1419: /*
1420: * Given the authentication method list sent by the server, return the
1421: * next method we should try. If the server initially sends a nil list,
1.67 markus 1422: * use a built-in default list.
1.41 stevesk 1423: */
1.76 itojun 1424: static Authmethod *
1.20 markus 1425: authmethod_get(char *authlist)
1426: {
1.53 markus 1427: char *name = NULL;
1.97 markus 1428: u_int next;
1.41 stevesk 1429:
1.20 markus 1430: /* Use a suitable default if we're passed a nil list. */
1431: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1432: authlist = options.preferred_authentications;
1.20 markus 1433:
1.53 markus 1434: if (supported == NULL || strcmp(authlist, supported) != 0) {
1435: debug3("start over, passed a different list %s", authlist);
1436: if (supported != NULL)
1437: xfree(supported);
1438: supported = xstrdup(authlist);
1439: preferred = options.preferred_authentications;
1440: debug3("preferred %s", preferred);
1441: current = NULL;
1442: } else if (current != NULL && authmethod_is_enabled(current))
1443: return current;
1.20 markus 1444:
1.53 markus 1445: for (;;) {
1446: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1447: debug("No more authentication methods to try.");
1.53 markus 1448: current = NULL;
1449: return NULL;
1450: }
1451: preferred += next;
1.23 markus 1452: debug3("authmethod_lookup %s", name);
1.53 markus 1453: debug3("remaining preferred: %s", preferred);
1454: if ((current = authmethod_lookup(name)) != NULL &&
1455: authmethod_is_enabled(current)) {
1.23 markus 1456: debug3("authmethod_is_enabled %s", name);
1.109 markus 1457: debug("Next authentication method: %s", name);
1.53 markus 1458: return current;
1.23 markus 1459: }
1.1 markus 1460: }
1.53 markus 1461: }
1.1 markus 1462:
1.79 stevesk 1463: static char *
1.53 markus 1464: authmethods_get(void)
1465: {
1466: Authmethod *method = NULL;
1.93 markus 1467: Buffer b;
1468: char *list;
1.27 provos 1469:
1.93 markus 1470: buffer_init(&b);
1.53 markus 1471: for (method = authmethods; method->name != NULL; method++) {
1472: if (authmethod_is_enabled(method)) {
1.93 markus 1473: if (buffer_len(&b) > 0)
1474: buffer_append(&b, ",", 1);
1475: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1476: }
1477: }
1.93 markus 1478: buffer_append(&b, "\0", 1);
1479: list = xstrdup(buffer_ptr(&b));
1480: buffer_free(&b);
1481: return list;
1.1 markus 1482: }
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