Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.144
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"
1.144 ! stevesk 26: RCSID("$OpenBSD: sshconnect2.c,v 1.143 2005/10/14 02:17:59 stevesk Exp $");
! 27:
! 28: #include <sys/queue.h>
1.1 markus 29:
30: #include "ssh.h"
1.37 markus 31: #include "ssh2.h"
1.1 markus 32: #include "xmalloc.h"
33: #include "buffer.h"
34: #include "packet.h"
35: #include "compat.h"
36: #include "bufaux.h"
1.37 markus 37: #include "cipher.h"
1.1 markus 38: #include "kex.h"
39: #include "myproposal.h"
40: #include "sshconnect.h"
41: #include "authfile.h"
1.57 provos 42: #include "dh.h"
1.17 markus 43: #include "authfd.h"
1.37 markus 44: #include "log.h"
45: #include "readconf.h"
1.137 djm 46: #include "misc.h"
1.53 markus 47: #include "match.h"
1.61 markus 48: #include "dispatch.h"
1.68 markus 49: #include "canohost.h"
1.100 markus 50: #include "msg.h"
51: #include "pathnames.h"
1.22 provos 52:
1.121 markus 53: #ifdef GSSAPI
54: #include "ssh-gss.h"
55: #endif
56:
1.1 markus 57: /* import */
58: extern char *client_version_string;
59: extern char *server_version_string;
60: extern Options options;
61:
62: /*
63: * SSH2 key exchange
64: */
65:
1.32 markus 66: u_char *session_id2 = NULL;
1.120 markus 67: u_int session_id2_len = 0;
1.1 markus 68:
1.61 markus 69: char *xxx_host;
70: struct sockaddr *xxx_hostaddr;
71:
1.63 markus 72: Kex *xxx_kex = NULL;
73:
1.76 itojun 74: static int
1.75 markus 75: verify_host_key_callback(Key *hostkey)
1.61 markus 76: {
1.75 markus 77: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 78: fatal("Host key verification failed.");
1.61 markus 79: return 0;
80: }
81:
1.1 markus 82: void
1.22 provos 83: ssh_kex2(char *host, struct sockaddr *hostaddr)
84: {
85: Kex *kex;
1.61 markus 86:
87: xxx_host = host;
88: xxx_hostaddr = hostaddr;
1.22 provos 89:
1.29 markus 90: if (options.ciphers == (char *)-1) {
1.116 itojun 91: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 92: options.ciphers = NULL;
1.24 markus 93: }
1.22 provos 94: if (options.ciphers != NULL) {
95: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
96: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
97: }
1.60 stevesk 98: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
99: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
100: myproposal[PROPOSAL_ENC_ALGS_STOC] =
101: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 102: if (options.compression) {
1.47 markus 103: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 104: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 105: } else {
1.47 markus 106: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 107: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 108: }
109: if (options.macs != NULL) {
110: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
111: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 112: }
1.70 markus 113: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 114: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 115: options.hostkeyalgorithms;
1.115 markus 116:
117: if (options.rekey_limit)
118: packet_set_rekey_limit(options.rekey_limit);
1.22 provos 119:
1.65 markus 120: /* start key exchange */
1.64 markus 121: kex = kex_setup(myproposal);
1.111 markus 122: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 123: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 124: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.61 markus 125: kex->client_version_string=client_version_string;
126: kex->server_version_string=server_version_string;
1.75 markus 127: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 128:
129: xxx_kex = kex;
1.22 provos 130:
1.66 markus 131: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 132:
133: session_id2 = kex->session_id;
134: session_id2_len = kex->session_id_len;
1.22 provos 135:
136: #ifdef DEBUG_KEXDH
137: /* send 1st encrypted/maced/compressed message */
138: packet_start(SSH2_MSG_IGNORE);
139: packet_put_cstring("markus");
140: packet_send();
141: packet_write_wait();
142: #endif
1.1 markus 143: }
1.11 markus 144:
1.1 markus 145: /*
146: * Authenticate user
147: */
1.20 markus 148:
149: typedef struct Authctxt Authctxt;
150: typedef struct Authmethod Authmethod;
1.117 markus 151: typedef struct identity Identity;
152: typedef struct idlist Idlist;
1.20 markus 153:
1.117 markus 154: struct identity {
155: TAILQ_ENTRY(identity) next;
156: AuthenticationConnection *ac; /* set if agent supports key */
157: Key *key; /* public/private key */
158: char *filename; /* comment for agent-only keys */
159: int tried;
160: int isprivate; /* key points to the private key */
161: };
162: TAILQ_HEAD(idlist, identity);
1.20 markus 163:
164: struct Authctxt {
165: const char *server_user;
1.68 markus 166: const char *local_user;
1.20 markus 167: const char *host;
168: const char *service;
1.23 markus 169: Authmethod *method;
1.20 markus 170: int success;
1.51 markus 171: char *authlist;
1.68 markus 172: /* pubkey */
1.117 markus 173: Idlist keys;
1.68 markus 174: AuthenticationConnection *agent;
175: /* hostbased */
1.100 markus 176: Sensitive *sensitive;
1.82 markus 177: /* kbd-interactive */
178: int info_req_seen;
1.121 markus 179: /* generic */
180: void *methoddata;
1.20 markus 181: };
182: struct Authmethod {
183: char *name; /* string to compare against server's list */
184: int (*userauth)(Authctxt *authctxt);
185: int *enabled; /* flag in option struct that enables method */
186: int *batch_flag; /* flag in option struct that disables method */
187: };
188:
1.92 markus 189: void input_userauth_success(int, u_int32_t, void *);
190: void input_userauth_failure(int, u_int32_t, void *);
191: void input_userauth_banner(int, u_int32_t, void *);
192: void input_userauth_error(int, u_int32_t, void *);
193: void input_userauth_info_req(int, u_int32_t, void *);
194: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 195: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 196:
197: int userauth_none(Authctxt *);
198: int userauth_pubkey(Authctxt *);
199: int userauth_passwd(Authctxt *);
200: int userauth_kbdint(Authctxt *);
201: int userauth_hostbased(Authctxt *);
1.118 markus 202: int userauth_kerberos(Authctxt *);
1.20 markus 203:
1.121 markus 204: #ifdef GSSAPI
205: int userauth_gssapi(Authctxt *authctxt);
206: void input_gssapi_response(int type, u_int32_t, void *);
207: void input_gssapi_token(int type, u_int32_t, void *);
208: void input_gssapi_hash(int type, u_int32_t, void *);
209: void input_gssapi_error(int, u_int32_t, void *);
210: void input_gssapi_errtok(int, u_int32_t, void *);
211: #endif
212:
1.86 itojun 213: void userauth(Authctxt *, char *);
1.51 markus 214:
1.117 markus 215: static int sign_and_send_pubkey(Authctxt *, Identity *);
216: static void pubkey_prepare(Authctxt *);
217: static void pubkey_cleanup(Authctxt *);
218: static Key *load_identity_file(char *);
1.76 itojun 219:
220: static Authmethod *authmethod_get(char *authlist);
221: static Authmethod *authmethod_lookup(const char *name);
222: static char *authmethods_get(void);
1.20 markus 223:
224: Authmethod authmethods[] = {
1.121 markus 225: #ifdef GSSAPI
1.132 markus 226: {"gssapi-with-mic",
1.121 markus 227: userauth_gssapi,
228: &options.gss_authentication,
229: NULL},
230: #endif
1.81 markus 231: {"hostbased",
232: userauth_hostbased,
233: &options.hostbased_authentication,
234: NULL},
1.20 markus 235: {"publickey",
236: userauth_pubkey,
1.28 markus 237: &options.pubkey_authentication,
1.20 markus 238: NULL},
1.81 markus 239: {"keyboard-interactive",
240: userauth_kbdint,
241: &options.kbd_interactive_authentication,
242: &options.batch_mode},
1.20 markus 243: {"password",
244: userauth_passwd,
245: &options.password_authentication,
1.23 markus 246: &options.batch_mode},
247: {"none",
248: userauth_none,
249: NULL,
250: NULL},
1.20 markus 251: {NULL, NULL, NULL, NULL}
252: };
253:
254: void
1.68 markus 255: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 256: Sensitive *sensitive)
1.20 markus 257: {
258: Authctxt authctxt;
259: int type;
1.39 markus 260:
1.73 markus 261: if (options.challenge_response_authentication)
1.39 markus 262: options.kbd_interactive_authentication = 1;
1.20 markus 263:
264: packet_start(SSH2_MSG_SERVICE_REQUEST);
265: packet_put_cstring("ssh-userauth");
266: packet_send();
1.108 markus 267: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 268: packet_write_wait();
1.91 markus 269: type = packet_read();
1.108 markus 270: if (type != SSH2_MSG_SERVICE_ACCEPT)
271: fatal("Server denied authentication request: %d", type);
1.20 markus 272: if (packet_remaining() > 0) {
1.91 markus 273: char *reply = packet_get_string(NULL);
1.108 markus 274: debug2("service_accept: %s", reply);
1.20 markus 275: xfree(reply);
276: } else {
1.109 markus 277: debug2("buggy server: service_accept w/o service");
1.20 markus 278: }
1.90 markus 279: packet_check_eom();
1.108 markus 280: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 281:
1.53 markus 282: if (options.preferred_authentications == NULL)
283: options.preferred_authentications = authmethods_get();
284:
1.20 markus 285: /* setup authentication context */
1.82 markus 286: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 287: pubkey_prepare(&authctxt);
1.20 markus 288: authctxt.server_user = server_user;
1.68 markus 289: authctxt.local_user = local_user;
1.20 markus 290: authctxt.host = host;
291: authctxt.service = "ssh-connection"; /* service name */
292: authctxt.success = 0;
1.23 markus 293: authctxt.method = authmethod_lookup("none");
1.51 markus 294: authctxt.authlist = NULL;
1.121 markus 295: authctxt.methoddata = NULL;
1.100 markus 296: authctxt.sensitive = sensitive;
1.82 markus 297: authctxt.info_req_seen = 0;
1.23 markus 298: if (authctxt.method == NULL)
299: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 300:
301: /* initial userauth request */
1.23 markus 302: userauth_none(&authctxt);
1.20 markus 303:
1.65 markus 304: dispatch_init(&input_userauth_error);
1.20 markus 305: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
306: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 307: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 308: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
309:
1.117 markus 310: pubkey_cleanup(&authctxt);
1.119 markus 311: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
312:
1.109 markus 313: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 314: }
1.119 markus 315:
1.20 markus 316: void
1.51 markus 317: userauth(Authctxt *authctxt, char *authlist)
318: {
1.121 markus 319: if (authctxt->methoddata) {
320: xfree(authctxt->methoddata);
321: authctxt->methoddata = NULL;
322: }
1.51 markus 323: if (authlist == NULL) {
324: authlist = authctxt->authlist;
325: } else {
326: if (authctxt->authlist)
327: xfree(authctxt->authlist);
328: authctxt->authlist = authlist;
329: }
330: for (;;) {
331: Authmethod *method = authmethod_get(authlist);
332: if (method == NULL)
333: fatal("Permission denied (%s).", authlist);
334: authctxt->method = method;
1.119 markus 335:
336: /* reset the per method handler */
337: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
338: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
339:
340: /* and try new method */
1.51 markus 341: if (method->userauth(authctxt) != 0) {
342: debug2("we sent a %s packet, wait for reply", method->name);
343: break;
344: } else {
345: debug2("we did not send a packet, disable method");
346: method->enabled = NULL;
347: }
348: }
349: }
1.105 deraadt 350:
1.51 markus 351: void
1.92 markus 352: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 353: {
1.35 markus 354: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 355: "type %d", type);
1.35 markus 356: }
1.105 deraadt 357:
1.35 markus 358: void
1.92 markus 359: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 360: {
361: char *msg, *lang;
1.126 deraadt 362:
1.35 markus 363: debug3("input_userauth_banner");
364: msg = packet_get_string(NULL);
365: lang = packet_get_string(NULL);
1.125 dtucker 366: if (options.log_level > SYSLOG_LEVEL_QUIET)
367: fprintf(stderr, "%s", msg);
1.35 markus 368: xfree(msg);
369: xfree(lang);
1.20 markus 370: }
1.105 deraadt 371:
1.20 markus 372: void
1.92 markus 373: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 374: {
375: Authctxt *authctxt = ctxt;
376: if (authctxt == NULL)
377: fatal("input_userauth_success: no authentication context");
1.126 deraadt 378: if (authctxt->authlist) {
1.51 markus 379: xfree(authctxt->authlist);
1.126 deraadt 380: authctxt->authlist = NULL;
381: }
382: if (authctxt->methoddata) {
1.121 markus 383: xfree(authctxt->methoddata);
1.126 deraadt 384: authctxt->methoddata = NULL;
385: }
1.20 markus 386: authctxt->success = 1; /* break out */
387: }
1.105 deraadt 388:
1.20 markus 389: void
1.92 markus 390: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 391: {
392: Authctxt *authctxt = ctxt;
393: char *authlist = NULL;
394: int partial;
395:
396: if (authctxt == NULL)
397: fatal("input_userauth_failure: no authentication context");
398:
1.23 markus 399: authlist = packet_get_string(NULL);
1.20 markus 400: partial = packet_get_char();
1.90 markus 401: packet_check_eom();
1.20 markus 402:
403: if (partial != 0)
1.116 itojun 404: logit("Authenticated with partial success.");
1.109 markus 405: debug("Authentications that can continue: %s", authlist);
1.20 markus 406:
1.51 markus 407: userauth(authctxt, authlist);
408: }
409: void
1.92 markus 410: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 411: {
412: Authctxt *authctxt = ctxt;
413: Key *key = NULL;
1.117 markus 414: Identity *id = NULL;
1.51 markus 415: Buffer b;
1.96 markus 416: int pktype, sent = 0;
417: u_int alen, blen;
418: char *pkalg, *fp;
419: u_char *pkblob;
1.51 markus 420:
421: if (authctxt == NULL)
422: fatal("input_userauth_pk_ok: no authentication context");
423: if (datafellows & SSH_BUG_PKOK) {
424: /* this is similar to SSH_BUG_PKAUTH */
425: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
426: pkblob = packet_get_string(&blen);
427: buffer_init(&b);
428: buffer_append(&b, pkblob, blen);
429: pkalg = buffer_get_string(&b, &alen);
430: buffer_free(&b);
431: } else {
432: pkalg = packet_get_string(&alen);
433: pkblob = packet_get_string(&blen);
434: }
1.90 markus 435: packet_check_eom();
1.51 markus 436:
1.117 markus 437: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 438:
1.117 markus 439: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
440: debug("unknown pkalg %s", pkalg);
441: goto done;
442: }
443: if ((key = key_from_blob(pkblob, blen)) == NULL) {
444: debug("no key from blob. pkalg %s", pkalg);
445: goto done;
446: }
447: if (key->type != pktype) {
448: error("input_userauth_pk_ok: type mismatch "
449: "for decoded key (received %d, expected %d)",
450: key->type, pktype);
451: goto done;
452: }
453: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
454: debug2("input_userauth_pk_ok: fp %s", fp);
455: xfree(fp);
456:
1.127 markus 457: /*
458: * search keys in the reverse order, because last candidate has been
459: * moved to the end of the queue. this also avoids confusion by
460: * duplicate keys
461: */
1.136 henning 462: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 463: if (key_equal(key, id->key)) {
464: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 465: break;
466: }
1.117 markus 467: }
468: done:
1.51 markus 469: if (key != NULL)
470: key_free(key);
471: xfree(pkalg);
472: xfree(pkblob);
473:
1.106 deraadt 474: /* try another method if we did not send a packet */
1.51 markus 475: if (sent == 0)
476: userauth(authctxt, NULL);
1.20 markus 477: }
1.121 markus 478:
479: #ifdef GSSAPI
1.133 djm 480: int
1.121 markus 481: userauth_gssapi(Authctxt *authctxt)
482: {
483: Gssctxt *gssctxt = NULL;
1.128 avsm 484: static gss_OID_set gss_supported = NULL;
1.139 djm 485: static u_int mech = 0;
1.121 markus 486: OM_uint32 min;
487: int ok = 0;
488:
489: /* Try one GSSAPI method at a time, rather than sending them all at
490: * once. */
491:
1.128 avsm 492: if (gss_supported == NULL)
493: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 494:
495: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 496: while (mech < gss_supported->count && !ok) {
1.121 markus 497: if (gssctxt)
498: ssh_gssapi_delete_ctx(&gssctxt);
499: ssh_gssapi_build_ctx(&gssctxt);
1.128 avsm 500: ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
1.121 markus 501:
502: /* My DER encoding requires length<128 */
1.128 avsm 503: if (gss_supported->elements[mech].length < 128 &&
1.121 markus 504: !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
505: authctxt->host))) {
506: ok = 1; /* Mechanism works */
507: } else {
508: mech++;
509: }
510: }
511:
1.139 djm 512: if (!ok)
513: return 0;
1.121 markus 514:
515: authctxt->methoddata=(void *)gssctxt;
516:
517: packet_start(SSH2_MSG_USERAUTH_REQUEST);
518: packet_put_cstring(authctxt->server_user);
519: packet_put_cstring(authctxt->service);
520: packet_put_cstring(authctxt->method->name);
521:
522: packet_put_int(1);
523:
1.129 markus 524: packet_put_int((gss_supported->elements[mech].length) + 2);
525: packet_put_char(SSH_GSS_OIDTYPE);
526: packet_put_char(gss_supported->elements[mech].length);
527: packet_put_raw(gss_supported->elements[mech].elements,
528: gss_supported->elements[mech].length);
1.121 markus 529:
530: packet_send();
531:
532: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
533: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
534: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
535: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
536:
537: mech++; /* Move along to next candidate */
538:
539: return 1;
540: }
541:
1.130 markus 542: static OM_uint32
543: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
544: {
545: Authctxt *authctxt = ctxt;
546: Gssctxt *gssctxt = authctxt->methoddata;
547: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 548: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
549: gss_buffer_desc gssbuf;
1.132 markus 550: OM_uint32 status, ms, flags;
551: Buffer b;
1.133 djm 552:
1.130 markus 553: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 554: recv_tok, &send_tok, &flags);
1.130 markus 555:
556: if (send_tok.length > 0) {
557: if (GSS_ERROR(status))
558: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
559: else
560: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 561:
1.130 markus 562: packet_put_string(send_tok.value, send_tok.length);
563: packet_send();
564: gss_release_buffer(&ms, &send_tok);
565: }
1.133 djm 566:
1.130 markus 567: if (status == GSS_S_COMPLETE) {
1.132 markus 568: /* send either complete or MIC, depending on mechanism */
569: if (!(flags & GSS_C_INTEG_FLAG)) {
570: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
571: packet_send();
572: } else {
573: ssh_gssapi_buildmic(&b, authctxt->server_user,
574: authctxt->service, "gssapi-with-mic");
575:
576: gssbuf.value = buffer_ptr(&b);
577: gssbuf.length = buffer_len(&b);
1.133 djm 578:
1.132 markus 579: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 580:
1.132 markus 581: if (!GSS_ERROR(status)) {
582: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
583: packet_put_string(mic.value, mic.length);
1.133 djm 584:
1.132 markus 585: packet_send();
586: }
1.133 djm 587:
1.132 markus 588: buffer_free(&b);
589: gss_release_buffer(&ms, &mic);
1.133 djm 590: }
1.130 markus 591: }
1.133 djm 592:
1.130 markus 593: return status;
594: }
595:
1.121 markus 596: void
597: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
598: {
599: Authctxt *authctxt = ctxt;
600: Gssctxt *gssctxt;
601: int oidlen;
602: char *oidv;
603:
604: if (authctxt == NULL)
605: fatal("input_gssapi_response: no authentication context");
606: gssctxt = authctxt->methoddata;
607:
608: /* Setup our OID */
609: oidv = packet_get_string(&oidlen);
610:
1.129 markus 611: if (oidlen <= 2 ||
612: oidv[0] != SSH_GSS_OIDTYPE ||
613: oidv[1] != oidlen - 2) {
1.130 markus 614: xfree(oidv);
1.129 markus 615: debug("Badly encoded mechanism OID received");
616: userauth(authctxt, NULL);
617: return;
1.121 markus 618: }
1.129 markus 619:
620: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
621: fatal("Server returned different OID than expected");
1.121 markus 622:
623: packet_check_eom();
624:
625: xfree(oidv);
626:
1.130 markus 627: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 628: /* Start again with next method on list */
629: debug("Trying to start again");
630: userauth(authctxt, NULL);
631: return;
632: }
633: }
634:
635: void
636: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
637: {
638: Authctxt *authctxt = ctxt;
639: gss_buffer_desc recv_tok;
1.130 markus 640: OM_uint32 status;
1.121 markus 641: u_int slen;
642:
643: if (authctxt == NULL)
644: fatal("input_gssapi_response: no authentication context");
645:
646: recv_tok.value = packet_get_string(&slen);
647: recv_tok.length = slen; /* safe typecast */
648:
649: packet_check_eom();
650:
1.130 markus 651: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 652:
653: xfree(recv_tok.value);
654:
655: if (GSS_ERROR(status)) {
656: /* Start again with the next method in the list */
657: userauth(authctxt, NULL);
658: return;
659: }
660: }
661:
662: void
663: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
664: {
665: Authctxt *authctxt = ctxt;
666: Gssctxt *gssctxt;
667: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
668: gss_buffer_desc recv_tok;
669: OM_uint32 status, ms;
1.123 deraadt 670: u_int len;
1.121 markus 671:
672: if (authctxt == NULL)
673: fatal("input_gssapi_response: no authentication context");
674: gssctxt = authctxt->methoddata;
675:
1.123 deraadt 676: recv_tok.value = packet_get_string(&len);
677: recv_tok.length = len;
1.121 markus 678:
679: packet_check_eom();
680:
681: /* Stick it into GSSAPI and see what it says */
682: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 683: &recv_tok, &send_tok, NULL);
1.121 markus 684:
685: xfree(recv_tok.value);
686: gss_release_buffer(&ms, &send_tok);
687:
688: /* Server will be returning a failed packet after this one */
689: }
690:
691: void
692: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
693: {
694: OM_uint32 maj, min;
695: char *msg;
696: char *lang;
697:
698: maj=packet_get_int();
699: min=packet_get_int();
700: msg=packet_get_string(NULL);
701: lang=packet_get_string(NULL);
702:
703: packet_check_eom();
704:
1.143 stevesk 705: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 706: xfree(msg);
707: xfree(lang);
708: }
709: #endif /* GSSAPI */
1.20 markus 710:
1.1 markus 711: int
1.23 markus 712: userauth_none(Authctxt *authctxt)
713: {
714: /* initial userauth request */
715: packet_start(SSH2_MSG_USERAUTH_REQUEST);
716: packet_put_cstring(authctxt->server_user);
717: packet_put_cstring(authctxt->service);
718: packet_put_cstring(authctxt->method->name);
719: packet_send();
720: return 1;
721: }
722:
723: int
1.20 markus 724: userauth_passwd(Authctxt *authctxt)
1.1 markus 725: {
1.6 markus 726: static int attempt = 0;
1.99 markus 727: char prompt[150];
1.1 markus 728: char *password;
1.6 markus 729:
1.13 todd 730: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 731: return 0;
1.13 todd 732:
1.87 deraadt 733: if (attempt != 1)
1.13 todd 734: error("Permission denied, please try again.");
1.1 markus 735:
1.43 itojun 736: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 737: authctxt->server_user, authctxt->host);
1.1 markus 738: password = read_passphrase(prompt, 0);
739: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 740: packet_put_cstring(authctxt->server_user);
741: packet_put_cstring(authctxt->service);
1.23 markus 742: packet_put_cstring(authctxt->method->name);
1.1 markus 743: packet_put_char(0);
1.49 markus 744: packet_put_cstring(password);
1.1 markus 745: memset(password, 0, strlen(password));
746: xfree(password);
1.85 markus 747: packet_add_padding(64);
1.1 markus 748: packet_send();
1.99 markus 749:
1.104 deraadt 750: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 751: &input_userauth_passwd_changereq);
752:
1.1 markus 753: return 1;
754: }
1.99 markus 755: /*
756: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
757: */
758: void
759: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
760: {
761: Authctxt *authctxt = ctxt;
762: char *info, *lang, *password = NULL, *retype = NULL;
763: char prompt[150];
764:
765: debug2("input_userauth_passwd_changereq");
766:
767: if (authctxt == NULL)
768: fatal("input_userauth_passwd_changereq: "
769: "no authentication context");
770:
771: info = packet_get_string(NULL);
772: lang = packet_get_string(NULL);
773: if (strlen(info) > 0)
1.116 itojun 774: logit("%s", info);
1.99 markus 775: xfree(info);
776: xfree(lang);
777: packet_start(SSH2_MSG_USERAUTH_REQUEST);
778: packet_put_cstring(authctxt->server_user);
779: packet_put_cstring(authctxt->service);
780: packet_put_cstring(authctxt->method->name);
781: packet_put_char(1); /* additional info */
1.104 deraadt 782: snprintf(prompt, sizeof(prompt),
1.99 markus 783: "Enter %.30s@%.128s's old password: ",
784: authctxt->server_user, authctxt->host);
785: password = read_passphrase(prompt, 0);
786: packet_put_cstring(password);
787: memset(password, 0, strlen(password));
788: xfree(password);
789: password = NULL;
790: while (password == NULL) {
1.104 deraadt 791: snprintf(prompt, sizeof(prompt),
1.99 markus 792: "Enter %.30s@%.128s's new password: ",
793: authctxt->server_user, authctxt->host);
794: password = read_passphrase(prompt, RP_ALLOW_EOF);
795: if (password == NULL) {
796: /* bail out */
797: return;
798: }
1.104 deraadt 799: snprintf(prompt, sizeof(prompt),
1.99 markus 800: "Retype %.30s@%.128s's new password: ",
801: authctxt->server_user, authctxt->host);
802: retype = read_passphrase(prompt, 0);
803: if (strcmp(password, retype) != 0) {
804: memset(password, 0, strlen(password));
805: xfree(password);
1.116 itojun 806: logit("Mismatch; try again, EOF to quit.");
1.99 markus 807: password = NULL;
808: }
809: memset(retype, 0, strlen(retype));
810: xfree(retype);
811: }
812: packet_put_cstring(password);
813: memset(password, 0, strlen(password));
814: xfree(password);
815: packet_add_padding(64);
816: packet_send();
1.104 deraadt 817:
818: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 819: &input_userauth_passwd_changereq);
1.117 markus 820: }
821:
822: static int
823: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
824: u_char *data, u_int datalen)
825: {
826: Key *prv;
827: int ret;
1.99 markus 828:
1.117 markus 829: /* the agent supports this key */
830: if (id->ac)
831: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
832: data, datalen));
833: /*
834: * we have already loaded the private key or
835: * the private key is stored in external hardware
836: */
837: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
838: return (key_sign(id->key, sigp, lenp, data, datalen));
839: /* load the private key from the file */
840: if ((prv = load_identity_file(id->filename)) == NULL)
841: return (-1);
842: ret = key_sign(prv, sigp, lenp, data, datalen);
843: key_free(prv);
844: return (ret);
1.51 markus 845: }
846:
1.76 itojun 847: static int
1.117 markus 848: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 849: {
850: Buffer b;
1.32 markus 851: u_char *blob, *signature;
1.96 markus 852: u_int bloblen, slen;
1.120 markus 853: u_int skip = 0;
1.17 markus 854: int ret = -1;
1.23 markus 855: int have_sig = 1;
1.1 markus 856:
1.30 markus 857: debug3("sign_and_send_pubkey");
1.51 markus 858:
1.117 markus 859: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 860: /* we cannot handle this key */
1.30 markus 861: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 862: return 0;
863: }
1.1 markus 864: /* data to be signed */
865: buffer_init(&b);
1.26 markus 866: if (datafellows & SSH_OLD_SESSIONID) {
867: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 868: skip = session_id2_len;
1.26 markus 869: } else {
1.14 markus 870: buffer_put_string(&b, session_id2, session_id2_len);
871: skip = buffer_len(&b);
872: }
1.1 markus 873: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 874: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 875: buffer_put_cstring(&b,
1.30 markus 876: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 877: "ssh-userauth" :
1.20 markus 878: authctxt->service);
1.30 markus 879: if (datafellows & SSH_BUG_PKAUTH) {
880: buffer_put_char(&b, have_sig);
881: } else {
882: buffer_put_cstring(&b, authctxt->method->name);
883: buffer_put_char(&b, have_sig);
1.117 markus 884: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 885: }
1.1 markus 886: buffer_put_string(&b, blob, bloblen);
887:
888: /* generate signature */
1.117 markus 889: ret = identity_sign(id, &signature, &slen,
1.51 markus 890: buffer_ptr(&b), buffer_len(&b));
1.17 markus 891: if (ret == -1) {
892: xfree(blob);
893: buffer_free(&b);
894: return 0;
895: }
1.28 markus 896: #ifdef DEBUG_PK
1.1 markus 897: buffer_dump(&b);
898: #endif
1.30 markus 899: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 900: buffer_clear(&b);
901: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 902: skip = session_id2_len;
1.10 markus 903: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 904: buffer_put_cstring(&b, authctxt->server_user);
905: buffer_put_cstring(&b, authctxt->service);
1.23 markus 906: buffer_put_cstring(&b, authctxt->method->name);
907: buffer_put_char(&b, have_sig);
1.30 markus 908: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 909: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 910: buffer_put_string(&b, blob, bloblen);
911: }
912: xfree(blob);
1.51 markus 913:
1.1 markus 914: /* append signature */
915: buffer_put_string(&b, signature, slen);
916: xfree(signature);
917:
918: /* skip session id and packet type */
1.14 markus 919: if (buffer_len(&b) < skip + 1)
1.20 markus 920: fatal("userauth_pubkey: internal error");
1.14 markus 921: buffer_consume(&b, skip + 1);
1.1 markus 922:
923: /* put remaining data from buffer into packet */
924: packet_start(SSH2_MSG_USERAUTH_REQUEST);
925: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
926: buffer_free(&b);
927: packet_send();
1.17 markus 928:
929: return 1;
1.16 markus 930: }
931:
1.76 itojun 932: static int
1.117 markus 933: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 934: {
1.51 markus 935: u_char *blob;
1.97 markus 936: u_int bloblen, have_sig = 0;
1.20 markus 937:
1.51 markus 938: debug3("send_pubkey_test");
1.16 markus 939:
1.117 markus 940: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 941: /* we cannot handle this key */
942: debug3("send_pubkey_test: cannot handle key");
1.16 markus 943: return 0;
944: }
1.51 markus 945: /* register callback for USERAUTH_PK_OK message */
946: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
947:
948: packet_start(SSH2_MSG_USERAUTH_REQUEST);
949: packet_put_cstring(authctxt->server_user);
950: packet_put_cstring(authctxt->service);
951: packet_put_cstring(authctxt->method->name);
952: packet_put_char(have_sig);
953: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 954: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 955: packet_put_string(blob, bloblen);
956: xfree(blob);
957: packet_send();
958: return 1;
959: }
960:
1.76 itojun 961: static Key *
1.51 markus 962: load_identity_file(char *filename)
963: {
964: Key *private;
965: char prompt[300], *passphrase;
1.56 markus 966: int quit, i;
1.52 markus 967: struct stat st;
1.16 markus 968:
1.52 markus 969: if (stat(filename, &st) < 0) {
970: debug3("no such identity: %s", filename);
971: return NULL;
972: }
1.56 markus 973: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
974: if (private == NULL) {
975: if (options.batch_mode)
1.51 markus 976: return NULL;
1.16 markus 977: snprintf(prompt, sizeof prompt,
1.88 deraadt 978: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 979: for (i = 0; i < options.number_of_password_prompts; i++) {
980: passphrase = read_passphrase(prompt, 0);
981: if (strcmp(passphrase, "") != 0) {
1.56 markus 982: private = key_load_private_type(KEY_UNSPEC, filename,
983: passphrase, NULL);
1.51 markus 984: quit = 0;
1.20 markus 985: } else {
986: debug2("no passphrase given, try next key");
1.51 markus 987: quit = 1;
1.20 markus 988: }
989: memset(passphrase, 0, strlen(passphrase));
990: xfree(passphrase);
1.56 markus 991: if (private != NULL || quit)
1.20 markus 992: break;
993: debug2("bad passphrase given, try again...");
1.16 markus 994: }
995: }
1.51 markus 996: return private;
997: }
998:
1.117 markus 999: /*
1000: * try keys in the following order:
1001: * 1. agent keys that are found in the config file
1002: * 2. other agent keys
1003: * 3. keys that are only listed in the config file
1004: */
1005: static void
1006: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1007: {
1.117 markus 1008: Identity *id;
1009: Idlist agent, files, *preferred;
1010: Key *key;
1011: AuthenticationConnection *ac;
1012: char *comment;
1013: int i, found;
1.51 markus 1014:
1.117 markus 1015: TAILQ_INIT(&agent); /* keys from the agent */
1016: TAILQ_INIT(&files); /* keys from the config file */
1017: preferred = &authctxt->keys;
1018: TAILQ_INIT(preferred); /* preferred order of keys */
1019:
1020: /* list of keys stored in the filesystem */
1021: for (i = 0; i < options.num_identity_files; i++) {
1022: key = options.identity_keys[i];
1023: if (key && key->type == KEY_RSA1)
1024: continue;
1025: options.identity_keys[i] = NULL;
1026: id = xmalloc(sizeof(*id));
1027: memset(id, 0, sizeof(*id));
1028: id->key = key;
1029: id->filename = xstrdup(options.identity_files[i]);
1030: TAILQ_INSERT_TAIL(&files, id, next);
1031: }
1032: /* list of keys supported by the agent */
1033: if ((ac = ssh_get_authentication_connection())) {
1034: for (key = ssh_get_first_identity(ac, &comment, 2);
1035: key != NULL;
1036: key = ssh_get_next_identity(ac, &comment, 2)) {
1037: found = 0;
1038: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1039: /* agent keys from the config file are preferred */
1.117 markus 1040: if (key_equal(key, id->key)) {
1041: key_free(key);
1042: xfree(comment);
1043: TAILQ_REMOVE(&files, id, next);
1044: TAILQ_INSERT_TAIL(preferred, id, next);
1045: id->ac = ac;
1046: found = 1;
1047: break;
1048: }
1049: }
1.135 markus 1050: if (!found && !options.identities_only) {
1.117 markus 1051: id = xmalloc(sizeof(*id));
1052: memset(id, 0, sizeof(*id));
1053: id->key = key;
1054: id->filename = comment;
1055: id->ac = ac;
1056: TAILQ_INSERT_TAIL(&agent, id, next);
1057: }
1058: }
1059: /* append remaining agent keys */
1060: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1061: TAILQ_REMOVE(&agent, id, next);
1062: TAILQ_INSERT_TAIL(preferred, id, next);
1063: }
1064: authctxt->agent = ac;
1065: }
1066: /* append remaining keys from the config file */
1067: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1068: TAILQ_REMOVE(&files, id, next);
1069: TAILQ_INSERT_TAIL(preferred, id, next);
1070: }
1071: TAILQ_FOREACH(id, preferred, next) {
1072: debug2("key: %s (%p)", id->filename, id->key);
1073: }
1.17 markus 1074: }
1075:
1.117 markus 1076: static void
1077: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1078: {
1.117 markus 1079: Identity *id;
1.51 markus 1080:
1.117 markus 1081: if (authctxt->agent != NULL)
1082: ssh_close_authentication_connection(authctxt->agent);
1083: for (id = TAILQ_FIRST(&authctxt->keys); id;
1084: id = TAILQ_FIRST(&authctxt->keys)) {
1085: TAILQ_REMOVE(&authctxt->keys, id, next);
1086: if (id->key)
1087: key_free(id->key);
1088: if (id->filename)
1089: xfree(id->filename);
1090: xfree(id);
1091: }
1.1 markus 1092: }
1093:
1.20 markus 1094: int
1095: userauth_pubkey(Authctxt *authctxt)
1096: {
1.117 markus 1097: Identity *id;
1.20 markus 1098: int sent = 0;
1099:
1.117 markus 1100: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1101: if (id->tried++)
1102: return (0);
1.127 markus 1103: /* move key to the end of the queue */
1.117 markus 1104: TAILQ_REMOVE(&authctxt->keys, id, next);
1105: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1106: /*
1107: * send a test message if we have the public key. for
1108: * encrypted keys we cannot do this and have to load the
1109: * private key instead
1110: */
1111: if (id->key && id->key->type != KEY_RSA1) {
1112: debug("Offering public key: %s", id->filename);
1113: sent = send_pubkey_test(authctxt, id);
1114: } else if (id->key == NULL) {
1115: debug("Trying private key: %s", id->filename);
1116: id->key = load_identity_file(id->filename);
1117: if (id->key != NULL) {
1118: id->isprivate = 1;
1119: sent = sign_and_send_pubkey(authctxt, id);
1120: key_free(id->key);
1121: id->key = NULL;
1.51 markus 1122: }
1123: }
1.117 markus 1124: if (sent)
1125: return (sent);
1.28 markus 1126: }
1.117 markus 1127: return (0);
1.20 markus 1128: }
1129:
1.23 markus 1130: /*
1131: * Send userauth request message specifying keyboard-interactive method.
1132: */
1133: int
1134: userauth_kbdint(Authctxt *authctxt)
1135: {
1136: static int attempt = 0;
1137:
1138: if (attempt++ >= options.number_of_password_prompts)
1139: return 0;
1.82 markus 1140: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1141: if (attempt > 1 && !authctxt->info_req_seen) {
1142: debug3("userauth_kbdint: disable: no info_req_seen");
1143: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1144: return 0;
1145: }
1.23 markus 1146:
1147: debug2("userauth_kbdint");
1148: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1149: packet_put_cstring(authctxt->server_user);
1150: packet_put_cstring(authctxt->service);
1151: packet_put_cstring(authctxt->method->name);
1152: packet_put_cstring(""); /* lang */
1153: packet_put_cstring(options.kbd_interactive_devices ?
1154: options.kbd_interactive_devices : "");
1155: packet_send();
1156:
1157: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1158: return 1;
1159: }
1160:
1161: /*
1.46 markus 1162: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1163: */
1164: void
1.92 markus 1165: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1166: {
1167: Authctxt *authctxt = ctxt;
1.46 markus 1168: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1169: u_int num_prompts, i;
1.23 markus 1170: int echo = 0;
1171:
1172: debug2("input_userauth_info_req");
1173:
1174: if (authctxt == NULL)
1175: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1176:
1177: authctxt->info_req_seen = 1;
1.23 markus 1178:
1179: name = packet_get_string(NULL);
1180: inst = packet_get_string(NULL);
1181: lang = packet_get_string(NULL);
1182: if (strlen(name) > 0)
1.116 itojun 1183: logit("%s", name);
1.23 markus 1184: if (strlen(inst) > 0)
1.116 itojun 1185: logit("%s", inst);
1.46 markus 1186: xfree(name);
1.23 markus 1187: xfree(inst);
1.46 markus 1188: xfree(lang);
1.23 markus 1189:
1190: num_prompts = packet_get_int();
1191: /*
1192: * Begin to build info response packet based on prompts requested.
1193: * We commit to providing the correct number of responses, so if
1194: * further on we run into a problem that prevents this, we have to
1195: * be sure and clean this up and send a correct error response.
1196: */
1197: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1198: packet_put_int(num_prompts);
1199:
1.73 markus 1200: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1201: for (i = 0; i < num_prompts; i++) {
1202: prompt = packet_get_string(NULL);
1203: echo = packet_get_char();
1204:
1.77 markus 1205: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1206:
1.49 markus 1207: packet_put_cstring(response);
1.23 markus 1208: memset(response, 0, strlen(response));
1209: xfree(response);
1210: xfree(prompt);
1211: }
1.90 markus 1212: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1213:
1.85 markus 1214: packet_add_padding(64);
1.23 markus 1215: packet_send();
1.68 markus 1216: }
1217:
1.100 markus 1218: static int
1.105 deraadt 1219: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1220: u_char *data, u_int datalen)
1221: {
1222: Buffer b;
1.101 markus 1223: struct stat st;
1.100 markus 1224: pid_t pid;
1.103 markus 1225: int to[2], from[2], status, version = 2;
1.100 markus 1226:
1.109 markus 1227: debug2("ssh_keysign called");
1.100 markus 1228:
1.101 markus 1229: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1230: error("ssh_keysign: no installed: %s", strerror(errno));
1231: return -1;
1232: }
1.100 markus 1233: if (fflush(stdout) != 0)
1234: error("ssh_keysign: fflush: %s", strerror(errno));
1235: if (pipe(to) < 0) {
1236: error("ssh_keysign: pipe: %s", strerror(errno));
1237: return -1;
1238: }
1239: if (pipe(from) < 0) {
1240: error("ssh_keysign: pipe: %s", strerror(errno));
1241: return -1;
1242: }
1243: if ((pid = fork()) < 0) {
1244: error("ssh_keysign: fork: %s", strerror(errno));
1245: return -1;
1246: }
1247: if (pid == 0) {
1248: seteuid(getuid());
1249: setuid(getuid());
1250: close(from[0]);
1251: if (dup2(from[1], STDOUT_FILENO) < 0)
1252: fatal("ssh_keysign: dup2: %s", strerror(errno));
1253: close(to[1]);
1254: if (dup2(to[0], STDIN_FILENO) < 0)
1255: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1256: close(from[1]);
1257: close(to[0]);
1.102 markus 1258: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1259: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1260: strerror(errno));
1261: }
1262: close(from[1]);
1263: close(to[0]);
1264:
1265: buffer_init(&b);
1.103 markus 1266: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1267: buffer_put_string(&b, data, datalen);
1.131 djm 1268: if (ssh_msg_send(to[1], version, &b) == -1)
1269: fatal("ssh_keysign: couldn't send request");
1.100 markus 1270:
1.110 djm 1271: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1272: error("ssh_keysign: no reply");
1.134 markus 1273: buffer_free(&b);
1.100 markus 1274: return -1;
1275: }
1.101 markus 1276: close(from[0]);
1277: close(to[1]);
1278:
1.103 markus 1279: while (waitpid(pid, &status, 0) < 0)
1280: if (errno != EINTR)
1281: break;
1.101 markus 1282:
1.100 markus 1283: if (buffer_get_char(&b) != version) {
1.101 markus 1284: error("ssh_keysign: bad version");
1.134 markus 1285: buffer_free(&b);
1.100 markus 1286: return -1;
1287: }
1288: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1289: buffer_free(&b);
1.100 markus 1290:
1291: return 0;
1292: }
1293:
1.68 markus 1294: int
1295: userauth_hostbased(Authctxt *authctxt)
1296: {
1297: Key *private = NULL;
1.100 markus 1298: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1299: Buffer b;
1300: u_char *signature, *blob;
1301: char *chost, *pkalg, *p;
1.72 markus 1302: const char *service;
1.68 markus 1303: u_int blen, slen;
1.71 markus 1304: int ok, i, len, found = 0;
1.68 markus 1305:
1306: /* check for a useful key */
1.100 markus 1307: for (i = 0; i < sensitive->nkeys; i++) {
1308: private = sensitive->keys[i];
1.68 markus 1309: if (private && private->type != KEY_RSA1) {
1310: found = 1;
1311: /* we take and free the key */
1.100 markus 1312: sensitive->keys[i] = NULL;
1.68 markus 1313: break;
1314: }
1315: }
1316: if (!found) {
1.109 markus 1317: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1318: return 0;
1319: }
1320: if (key_to_blob(private, &blob, &blen) == 0) {
1321: key_free(private);
1322: return 0;
1323: }
1.84 markus 1324: /* figure out a name for the client host */
1325: p = get_local_name(packet_get_connection_in());
1326: if (p == NULL) {
1327: error("userauth_hostbased: cannot get local ipaddr/name");
1328: key_free(private);
1329: return 0;
1330: }
1331: len = strlen(p) + 2;
1332: chost = xmalloc(len);
1333: strlcpy(chost, p, len);
1334: strlcat(chost, ".", len);
1335: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1336: xfree(p);
1.84 markus 1337:
1.72 markus 1338: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1339: authctxt->service;
1.68 markus 1340: pkalg = xstrdup(key_ssh_name(private));
1341: buffer_init(&b);
1342: /* construct data */
1.72 markus 1343: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1344: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1345: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1346: buffer_put_cstring(&b, service);
1.68 markus 1347: buffer_put_cstring(&b, authctxt->method->name);
1348: buffer_put_cstring(&b, pkalg);
1349: buffer_put_string(&b, blob, blen);
1350: buffer_put_cstring(&b, chost);
1351: buffer_put_cstring(&b, authctxt->local_user);
1352: #ifdef DEBUG_PK
1353: buffer_dump(&b);
1354: #endif
1.100 markus 1355: if (sensitive->external_keysign)
1356: ok = ssh_keysign(private, &signature, &slen,
1357: buffer_ptr(&b), buffer_len(&b));
1358: else
1359: ok = key_sign(private, &signature, &slen,
1360: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1361: key_free(private);
1362: buffer_free(&b);
1363: if (ok != 0) {
1364: error("key_sign failed");
1365: xfree(chost);
1366: xfree(pkalg);
1367: return 0;
1368: }
1369: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1370: packet_put_cstring(authctxt->server_user);
1371: packet_put_cstring(authctxt->service);
1372: packet_put_cstring(authctxt->method->name);
1373: packet_put_cstring(pkalg);
1374: packet_put_string(blob, blen);
1375: packet_put_cstring(chost);
1376: packet_put_cstring(authctxt->local_user);
1377: packet_put_string(signature, slen);
1378: memset(signature, 's', slen);
1379: xfree(signature);
1380: xfree(chost);
1381: xfree(pkalg);
1382:
1383: packet_send();
1384: return 1;
1.23 markus 1385: }
1.20 markus 1386:
1387: /* find auth method */
1388:
1389: /*
1390: * given auth method name, if configurable options permit this method fill
1391: * in auth_ident field and return true, otherwise return false.
1392: */
1.76 itojun 1393: static int
1.20 markus 1394: authmethod_is_enabled(Authmethod *method)
1395: {
1396: if (method == NULL)
1397: return 0;
1398: /* return false if options indicate this method is disabled */
1399: if (method->enabled == NULL || *method->enabled == 0)
1400: return 0;
1401: /* return false if batch mode is enabled but method needs interactive mode */
1402: if (method->batch_flag != NULL && *method->batch_flag != 0)
1403: return 0;
1404: return 1;
1405: }
1406:
1.76 itojun 1407: static Authmethod *
1.20 markus 1408: authmethod_lookup(const char *name)
1.1 markus 1409: {
1.20 markus 1410: Authmethod *method = NULL;
1411: if (name != NULL)
1412: for (method = authmethods; method->name != NULL; method++)
1413: if (strcmp(name, method->name) == 0)
1414: return method;
1415: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1416: return NULL;
1417: }
1.1 markus 1418:
1.53 markus 1419: /* XXX internal state */
1420: static Authmethod *current = NULL;
1421: static char *supported = NULL;
1422: static char *preferred = NULL;
1.105 deraadt 1423:
1.20 markus 1424: /*
1425: * Given the authentication method list sent by the server, return the
1426: * next method we should try. If the server initially sends a nil list,
1.67 markus 1427: * use a built-in default list.
1.41 stevesk 1428: */
1.76 itojun 1429: static Authmethod *
1.20 markus 1430: authmethod_get(char *authlist)
1431: {
1.53 markus 1432: char *name = NULL;
1.97 markus 1433: u_int next;
1.41 stevesk 1434:
1.20 markus 1435: /* Use a suitable default if we're passed a nil list. */
1436: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1437: authlist = options.preferred_authentications;
1.20 markus 1438:
1.53 markus 1439: if (supported == NULL || strcmp(authlist, supported) != 0) {
1440: debug3("start over, passed a different list %s", authlist);
1441: if (supported != NULL)
1442: xfree(supported);
1443: supported = xstrdup(authlist);
1444: preferred = options.preferred_authentications;
1445: debug3("preferred %s", preferred);
1446: current = NULL;
1447: } else if (current != NULL && authmethod_is_enabled(current))
1448: return current;
1.20 markus 1449:
1.53 markus 1450: for (;;) {
1451: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1452: debug("No more authentication methods to try.");
1.53 markus 1453: current = NULL;
1454: return NULL;
1455: }
1456: preferred += next;
1.23 markus 1457: debug3("authmethod_lookup %s", name);
1.53 markus 1458: debug3("remaining preferred: %s", preferred);
1459: if ((current = authmethod_lookup(name)) != NULL &&
1460: authmethod_is_enabled(current)) {
1.23 markus 1461: debug3("authmethod_is_enabled %s", name);
1.109 markus 1462: debug("Next authentication method: %s", name);
1.53 markus 1463: return current;
1.23 markus 1464: }
1.1 markus 1465: }
1.53 markus 1466: }
1.1 markus 1467:
1.79 stevesk 1468: static char *
1.53 markus 1469: authmethods_get(void)
1470: {
1471: Authmethod *method = NULL;
1.93 markus 1472: Buffer b;
1473: char *list;
1.27 provos 1474:
1.93 markus 1475: buffer_init(&b);
1.53 markus 1476: for (method = authmethods; method->name != NULL; method++) {
1477: if (authmethod_is_enabled(method)) {
1.93 markus 1478: if (buffer_len(&b) > 0)
1479: buffer_append(&b, ",", 1);
1480: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1481: }
1482: }
1.93 markus 1483: buffer_append(&b, "\0", 1);
1484: list = xstrdup(buffer_ptr(&b));
1485: buffer_free(&b);
1486: return list;
1.1 markus 1487: }
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