Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.147
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"
1.147 ! djm 26: RCSID("$OpenBSD: sshconnect2.c,v 1.146 2006/02/20 17:19:54 stevesk Exp $");
1.144 stevesk 27:
1.145 stevesk 28: #include <sys/types.h>
29: #include <sys/wait.h>
1.144 stevesk 30: #include <sys/queue.h>
1.146 stevesk 31: #include <sys/stat.h>
1.1 markus 32:
33: #include "ssh.h"
1.37 markus 34: #include "ssh2.h"
1.1 markus 35: #include "xmalloc.h"
36: #include "buffer.h"
37: #include "packet.h"
38: #include "compat.h"
39: #include "bufaux.h"
1.37 markus 40: #include "cipher.h"
1.1 markus 41: #include "kex.h"
42: #include "myproposal.h"
43: #include "sshconnect.h"
44: #include "authfile.h"
1.57 provos 45: #include "dh.h"
1.17 markus 46: #include "authfd.h"
1.37 markus 47: #include "log.h"
48: #include "readconf.h"
1.137 djm 49: #include "misc.h"
1.53 markus 50: #include "match.h"
1.61 markus 51: #include "dispatch.h"
1.68 markus 52: #include "canohost.h"
1.100 markus 53: #include "msg.h"
54: #include "pathnames.h"
1.22 provos 55:
1.121 markus 56: #ifdef GSSAPI
57: #include "ssh-gss.h"
58: #endif
59:
1.1 markus 60: /* import */
61: extern char *client_version_string;
62: extern char *server_version_string;
63: extern Options options;
64:
65: /*
66: * SSH2 key exchange
67: */
68:
1.32 markus 69: u_char *session_id2 = NULL;
1.120 markus 70: u_int session_id2_len = 0;
1.1 markus 71:
1.61 markus 72: char *xxx_host;
73: struct sockaddr *xxx_hostaddr;
74:
1.63 markus 75: Kex *xxx_kex = NULL;
76:
1.76 itojun 77: static int
1.75 markus 78: verify_host_key_callback(Key *hostkey)
1.61 markus 79: {
1.75 markus 80: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 81: fatal("Host key verification failed.");
1.61 markus 82: return 0;
83: }
84:
1.1 markus 85: void
1.22 provos 86: ssh_kex2(char *host, struct sockaddr *hostaddr)
87: {
88: Kex *kex;
1.61 markus 89:
90: xxx_host = host;
91: xxx_hostaddr = hostaddr;
1.22 provos 92:
1.29 markus 93: if (options.ciphers == (char *)-1) {
1.116 itojun 94: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 95: options.ciphers = NULL;
1.24 markus 96: }
1.22 provos 97: if (options.ciphers != NULL) {
98: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
99: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
100: }
1.60 stevesk 101: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
102: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
103: myproposal[PROPOSAL_ENC_ALGS_STOC] =
104: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 105: if (options.compression) {
1.47 markus 106: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 107: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 108: } else {
1.47 markus 109: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 110: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 111: }
112: if (options.macs != NULL) {
113: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
114: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 115: }
1.70 markus 116: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 117: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 118: options.hostkeyalgorithms;
1.115 markus 119:
120: if (options.rekey_limit)
121: packet_set_rekey_limit(options.rekey_limit);
1.22 provos 122:
1.65 markus 123: /* start key exchange */
1.64 markus 124: kex = kex_setup(myproposal);
1.111 markus 125: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 126: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 127: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 ! djm 128: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.61 markus 129: kex->client_version_string=client_version_string;
130: kex->server_version_string=server_version_string;
1.75 markus 131: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 132:
133: xxx_kex = kex;
1.22 provos 134:
1.66 markus 135: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 136:
137: session_id2 = kex->session_id;
138: session_id2_len = kex->session_id_len;
1.22 provos 139:
140: #ifdef DEBUG_KEXDH
141: /* send 1st encrypted/maced/compressed message */
142: packet_start(SSH2_MSG_IGNORE);
143: packet_put_cstring("markus");
144: packet_send();
145: packet_write_wait();
146: #endif
1.1 markus 147: }
1.11 markus 148:
1.1 markus 149: /*
150: * Authenticate user
151: */
1.20 markus 152:
153: typedef struct Authctxt Authctxt;
154: typedef struct Authmethod Authmethod;
1.117 markus 155: typedef struct identity Identity;
156: typedef struct idlist Idlist;
1.20 markus 157:
1.117 markus 158: struct identity {
159: TAILQ_ENTRY(identity) next;
160: AuthenticationConnection *ac; /* set if agent supports key */
161: Key *key; /* public/private key */
162: char *filename; /* comment for agent-only keys */
163: int tried;
164: int isprivate; /* key points to the private key */
165: };
166: TAILQ_HEAD(idlist, identity);
1.20 markus 167:
168: struct Authctxt {
169: const char *server_user;
1.68 markus 170: const char *local_user;
1.20 markus 171: const char *host;
172: const char *service;
1.23 markus 173: Authmethod *method;
1.20 markus 174: int success;
1.51 markus 175: char *authlist;
1.68 markus 176: /* pubkey */
1.117 markus 177: Idlist keys;
1.68 markus 178: AuthenticationConnection *agent;
179: /* hostbased */
1.100 markus 180: Sensitive *sensitive;
1.82 markus 181: /* kbd-interactive */
182: int info_req_seen;
1.121 markus 183: /* generic */
184: void *methoddata;
1.20 markus 185: };
186: struct Authmethod {
187: char *name; /* string to compare against server's list */
188: int (*userauth)(Authctxt *authctxt);
189: int *enabled; /* flag in option struct that enables method */
190: int *batch_flag; /* flag in option struct that disables method */
191: };
192:
1.92 markus 193: void input_userauth_success(int, u_int32_t, void *);
194: void input_userauth_failure(int, u_int32_t, void *);
195: void input_userauth_banner(int, u_int32_t, void *);
196: void input_userauth_error(int, u_int32_t, void *);
197: void input_userauth_info_req(int, u_int32_t, void *);
198: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 199: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 200:
201: int userauth_none(Authctxt *);
202: int userauth_pubkey(Authctxt *);
203: int userauth_passwd(Authctxt *);
204: int userauth_kbdint(Authctxt *);
205: int userauth_hostbased(Authctxt *);
1.118 markus 206: int userauth_kerberos(Authctxt *);
1.20 markus 207:
1.121 markus 208: #ifdef GSSAPI
209: int userauth_gssapi(Authctxt *authctxt);
210: void input_gssapi_response(int type, u_int32_t, void *);
211: void input_gssapi_token(int type, u_int32_t, void *);
212: void input_gssapi_hash(int type, u_int32_t, void *);
213: void input_gssapi_error(int, u_int32_t, void *);
214: void input_gssapi_errtok(int, u_int32_t, void *);
215: #endif
216:
1.86 itojun 217: void userauth(Authctxt *, char *);
1.51 markus 218:
1.117 markus 219: static int sign_and_send_pubkey(Authctxt *, Identity *);
220: static void pubkey_prepare(Authctxt *);
221: static void pubkey_cleanup(Authctxt *);
222: static Key *load_identity_file(char *);
1.76 itojun 223:
224: static Authmethod *authmethod_get(char *authlist);
225: static Authmethod *authmethod_lookup(const char *name);
226: static char *authmethods_get(void);
1.20 markus 227:
228: Authmethod authmethods[] = {
1.121 markus 229: #ifdef GSSAPI
1.132 markus 230: {"gssapi-with-mic",
1.121 markus 231: userauth_gssapi,
232: &options.gss_authentication,
233: NULL},
234: #endif
1.81 markus 235: {"hostbased",
236: userauth_hostbased,
237: &options.hostbased_authentication,
238: NULL},
1.20 markus 239: {"publickey",
240: userauth_pubkey,
1.28 markus 241: &options.pubkey_authentication,
1.20 markus 242: NULL},
1.81 markus 243: {"keyboard-interactive",
244: userauth_kbdint,
245: &options.kbd_interactive_authentication,
246: &options.batch_mode},
1.20 markus 247: {"password",
248: userauth_passwd,
249: &options.password_authentication,
1.23 markus 250: &options.batch_mode},
251: {"none",
252: userauth_none,
253: NULL,
254: NULL},
1.20 markus 255: {NULL, NULL, NULL, NULL}
256: };
257:
258: void
1.68 markus 259: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 260: Sensitive *sensitive)
1.20 markus 261: {
262: Authctxt authctxt;
263: int type;
1.39 markus 264:
1.73 markus 265: if (options.challenge_response_authentication)
1.39 markus 266: options.kbd_interactive_authentication = 1;
1.20 markus 267:
268: packet_start(SSH2_MSG_SERVICE_REQUEST);
269: packet_put_cstring("ssh-userauth");
270: packet_send();
1.108 markus 271: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 272: packet_write_wait();
1.91 markus 273: type = packet_read();
1.108 markus 274: if (type != SSH2_MSG_SERVICE_ACCEPT)
275: fatal("Server denied authentication request: %d", type);
1.20 markus 276: if (packet_remaining() > 0) {
1.91 markus 277: char *reply = packet_get_string(NULL);
1.108 markus 278: debug2("service_accept: %s", reply);
1.20 markus 279: xfree(reply);
280: } else {
1.109 markus 281: debug2("buggy server: service_accept w/o service");
1.20 markus 282: }
1.90 markus 283: packet_check_eom();
1.108 markus 284: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 285:
1.53 markus 286: if (options.preferred_authentications == NULL)
287: options.preferred_authentications = authmethods_get();
288:
1.20 markus 289: /* setup authentication context */
1.82 markus 290: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 291: pubkey_prepare(&authctxt);
1.20 markus 292: authctxt.server_user = server_user;
1.68 markus 293: authctxt.local_user = local_user;
1.20 markus 294: authctxt.host = host;
295: authctxt.service = "ssh-connection"; /* service name */
296: authctxt.success = 0;
1.23 markus 297: authctxt.method = authmethod_lookup("none");
1.51 markus 298: authctxt.authlist = NULL;
1.121 markus 299: authctxt.methoddata = NULL;
1.100 markus 300: authctxt.sensitive = sensitive;
1.82 markus 301: authctxt.info_req_seen = 0;
1.23 markus 302: if (authctxt.method == NULL)
303: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 304:
305: /* initial userauth request */
1.23 markus 306: userauth_none(&authctxt);
1.20 markus 307:
1.65 markus 308: dispatch_init(&input_userauth_error);
1.20 markus 309: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
310: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 311: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 312: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
313:
1.117 markus 314: pubkey_cleanup(&authctxt);
1.119 markus 315: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
316:
1.109 markus 317: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 318: }
1.119 markus 319:
1.20 markus 320: void
1.51 markus 321: userauth(Authctxt *authctxt, char *authlist)
322: {
1.121 markus 323: if (authctxt->methoddata) {
324: xfree(authctxt->methoddata);
325: authctxt->methoddata = NULL;
326: }
1.51 markus 327: if (authlist == NULL) {
328: authlist = authctxt->authlist;
329: } else {
330: if (authctxt->authlist)
331: xfree(authctxt->authlist);
332: authctxt->authlist = authlist;
333: }
334: for (;;) {
335: Authmethod *method = authmethod_get(authlist);
336: if (method == NULL)
337: fatal("Permission denied (%s).", authlist);
338: authctxt->method = method;
1.119 markus 339:
340: /* reset the per method handler */
341: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
342: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
343:
344: /* and try new method */
1.51 markus 345: if (method->userauth(authctxt) != 0) {
346: debug2("we sent a %s packet, wait for reply", method->name);
347: break;
348: } else {
349: debug2("we did not send a packet, disable method");
350: method->enabled = NULL;
351: }
352: }
353: }
1.105 deraadt 354:
1.51 markus 355: void
1.92 markus 356: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 357: {
1.35 markus 358: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 359: "type %d", type);
1.35 markus 360: }
1.105 deraadt 361:
1.35 markus 362: void
1.92 markus 363: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 364: {
365: char *msg, *lang;
1.126 deraadt 366:
1.35 markus 367: debug3("input_userauth_banner");
368: msg = packet_get_string(NULL);
369: lang = packet_get_string(NULL);
1.125 dtucker 370: if (options.log_level > SYSLOG_LEVEL_QUIET)
371: fprintf(stderr, "%s", msg);
1.35 markus 372: xfree(msg);
373: xfree(lang);
1.20 markus 374: }
1.105 deraadt 375:
1.20 markus 376: void
1.92 markus 377: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 378: {
379: Authctxt *authctxt = ctxt;
380: if (authctxt == NULL)
381: fatal("input_userauth_success: no authentication context");
1.126 deraadt 382: if (authctxt->authlist) {
1.51 markus 383: xfree(authctxt->authlist);
1.126 deraadt 384: authctxt->authlist = NULL;
385: }
386: if (authctxt->methoddata) {
1.121 markus 387: xfree(authctxt->methoddata);
1.126 deraadt 388: authctxt->methoddata = NULL;
389: }
1.20 markus 390: authctxt->success = 1; /* break out */
391: }
1.105 deraadt 392:
1.20 markus 393: void
1.92 markus 394: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 395: {
396: Authctxt *authctxt = ctxt;
397: char *authlist = NULL;
398: int partial;
399:
400: if (authctxt == NULL)
401: fatal("input_userauth_failure: no authentication context");
402:
1.23 markus 403: authlist = packet_get_string(NULL);
1.20 markus 404: partial = packet_get_char();
1.90 markus 405: packet_check_eom();
1.20 markus 406:
407: if (partial != 0)
1.116 itojun 408: logit("Authenticated with partial success.");
1.109 markus 409: debug("Authentications that can continue: %s", authlist);
1.20 markus 410:
1.51 markus 411: userauth(authctxt, authlist);
412: }
413: void
1.92 markus 414: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 415: {
416: Authctxt *authctxt = ctxt;
417: Key *key = NULL;
1.117 markus 418: Identity *id = NULL;
1.51 markus 419: Buffer b;
1.96 markus 420: int pktype, sent = 0;
421: u_int alen, blen;
422: char *pkalg, *fp;
423: u_char *pkblob;
1.51 markus 424:
425: if (authctxt == NULL)
426: fatal("input_userauth_pk_ok: no authentication context");
427: if (datafellows & SSH_BUG_PKOK) {
428: /* this is similar to SSH_BUG_PKAUTH */
429: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
430: pkblob = packet_get_string(&blen);
431: buffer_init(&b);
432: buffer_append(&b, pkblob, blen);
433: pkalg = buffer_get_string(&b, &alen);
434: buffer_free(&b);
435: } else {
436: pkalg = packet_get_string(&alen);
437: pkblob = packet_get_string(&blen);
438: }
1.90 markus 439: packet_check_eom();
1.51 markus 440:
1.117 markus 441: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 442:
1.117 markus 443: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
444: debug("unknown pkalg %s", pkalg);
445: goto done;
446: }
447: if ((key = key_from_blob(pkblob, blen)) == NULL) {
448: debug("no key from blob. pkalg %s", pkalg);
449: goto done;
450: }
451: if (key->type != pktype) {
452: error("input_userauth_pk_ok: type mismatch "
453: "for decoded key (received %d, expected %d)",
454: key->type, pktype);
455: goto done;
456: }
457: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
458: debug2("input_userauth_pk_ok: fp %s", fp);
459: xfree(fp);
460:
1.127 markus 461: /*
462: * search keys in the reverse order, because last candidate has been
463: * moved to the end of the queue. this also avoids confusion by
464: * duplicate keys
465: */
1.136 henning 466: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 467: if (key_equal(key, id->key)) {
468: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 469: break;
470: }
1.117 markus 471: }
472: done:
1.51 markus 473: if (key != NULL)
474: key_free(key);
475: xfree(pkalg);
476: xfree(pkblob);
477:
1.106 deraadt 478: /* try another method if we did not send a packet */
1.51 markus 479: if (sent == 0)
480: userauth(authctxt, NULL);
1.20 markus 481: }
1.121 markus 482:
483: #ifdef GSSAPI
1.133 djm 484: int
1.121 markus 485: userauth_gssapi(Authctxt *authctxt)
486: {
487: Gssctxt *gssctxt = NULL;
1.128 avsm 488: static gss_OID_set gss_supported = NULL;
1.139 djm 489: static u_int mech = 0;
1.121 markus 490: OM_uint32 min;
491: int ok = 0;
492:
493: /* Try one GSSAPI method at a time, rather than sending them all at
494: * once. */
495:
1.128 avsm 496: if (gss_supported == NULL)
497: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 498:
499: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 500: while (mech < gss_supported->count && !ok) {
1.121 markus 501: if (gssctxt)
502: ssh_gssapi_delete_ctx(&gssctxt);
503: ssh_gssapi_build_ctx(&gssctxt);
1.128 avsm 504: ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
1.121 markus 505:
506: /* My DER encoding requires length<128 */
1.128 avsm 507: if (gss_supported->elements[mech].length < 128 &&
1.121 markus 508: !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
509: authctxt->host))) {
510: ok = 1; /* Mechanism works */
511: } else {
512: mech++;
513: }
514: }
515:
1.139 djm 516: if (!ok)
517: return 0;
1.121 markus 518:
519: authctxt->methoddata=(void *)gssctxt;
520:
521: packet_start(SSH2_MSG_USERAUTH_REQUEST);
522: packet_put_cstring(authctxt->server_user);
523: packet_put_cstring(authctxt->service);
524: packet_put_cstring(authctxt->method->name);
525:
526: packet_put_int(1);
527:
1.129 markus 528: packet_put_int((gss_supported->elements[mech].length) + 2);
529: packet_put_char(SSH_GSS_OIDTYPE);
530: packet_put_char(gss_supported->elements[mech].length);
531: packet_put_raw(gss_supported->elements[mech].elements,
532: gss_supported->elements[mech].length);
1.121 markus 533:
534: packet_send();
535:
536: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
537: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
538: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
539: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
540:
541: mech++; /* Move along to next candidate */
542:
543: return 1;
544: }
545:
1.130 markus 546: static OM_uint32
547: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
548: {
549: Authctxt *authctxt = ctxt;
550: Gssctxt *gssctxt = authctxt->methoddata;
551: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 552: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
553: gss_buffer_desc gssbuf;
1.132 markus 554: OM_uint32 status, ms, flags;
555: Buffer b;
1.133 djm 556:
1.130 markus 557: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 558: recv_tok, &send_tok, &flags);
1.130 markus 559:
560: if (send_tok.length > 0) {
561: if (GSS_ERROR(status))
562: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
563: else
564: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 565:
1.130 markus 566: packet_put_string(send_tok.value, send_tok.length);
567: packet_send();
568: gss_release_buffer(&ms, &send_tok);
569: }
1.133 djm 570:
1.130 markus 571: if (status == GSS_S_COMPLETE) {
1.132 markus 572: /* send either complete or MIC, depending on mechanism */
573: if (!(flags & GSS_C_INTEG_FLAG)) {
574: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
575: packet_send();
576: } else {
577: ssh_gssapi_buildmic(&b, authctxt->server_user,
578: authctxt->service, "gssapi-with-mic");
579:
580: gssbuf.value = buffer_ptr(&b);
581: gssbuf.length = buffer_len(&b);
1.133 djm 582:
1.132 markus 583: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 584:
1.132 markus 585: if (!GSS_ERROR(status)) {
586: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
587: packet_put_string(mic.value, mic.length);
1.133 djm 588:
1.132 markus 589: packet_send();
590: }
1.133 djm 591:
1.132 markus 592: buffer_free(&b);
593: gss_release_buffer(&ms, &mic);
1.133 djm 594: }
1.130 markus 595: }
1.133 djm 596:
1.130 markus 597: return status;
598: }
599:
1.121 markus 600: void
601: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
602: {
603: Authctxt *authctxt = ctxt;
604: Gssctxt *gssctxt;
605: int oidlen;
606: char *oidv;
607:
608: if (authctxt == NULL)
609: fatal("input_gssapi_response: no authentication context");
610: gssctxt = authctxt->methoddata;
611:
612: /* Setup our OID */
613: oidv = packet_get_string(&oidlen);
614:
1.129 markus 615: if (oidlen <= 2 ||
616: oidv[0] != SSH_GSS_OIDTYPE ||
617: oidv[1] != oidlen - 2) {
1.130 markus 618: xfree(oidv);
1.129 markus 619: debug("Badly encoded mechanism OID received");
620: userauth(authctxt, NULL);
621: return;
1.121 markus 622: }
1.129 markus 623:
624: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
625: fatal("Server returned different OID than expected");
1.121 markus 626:
627: packet_check_eom();
628:
629: xfree(oidv);
630:
1.130 markus 631: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 632: /* Start again with next method on list */
633: debug("Trying to start again");
634: userauth(authctxt, NULL);
635: return;
636: }
637: }
638:
639: void
640: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
641: {
642: Authctxt *authctxt = ctxt;
643: gss_buffer_desc recv_tok;
1.130 markus 644: OM_uint32 status;
1.121 markus 645: u_int slen;
646:
647: if (authctxt == NULL)
648: fatal("input_gssapi_response: no authentication context");
649:
650: recv_tok.value = packet_get_string(&slen);
651: recv_tok.length = slen; /* safe typecast */
652:
653: packet_check_eom();
654:
1.130 markus 655: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 656:
657: xfree(recv_tok.value);
658:
659: if (GSS_ERROR(status)) {
660: /* Start again with the next method in the list */
661: userauth(authctxt, NULL);
662: return;
663: }
664: }
665:
666: void
667: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
668: {
669: Authctxt *authctxt = ctxt;
670: Gssctxt *gssctxt;
671: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
672: gss_buffer_desc recv_tok;
673: OM_uint32 status, ms;
1.123 deraadt 674: u_int len;
1.121 markus 675:
676: if (authctxt == NULL)
677: fatal("input_gssapi_response: no authentication context");
678: gssctxt = authctxt->methoddata;
679:
1.123 deraadt 680: recv_tok.value = packet_get_string(&len);
681: recv_tok.length = len;
1.121 markus 682:
683: packet_check_eom();
684:
685: /* Stick it into GSSAPI and see what it says */
686: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 687: &recv_tok, &send_tok, NULL);
1.121 markus 688:
689: xfree(recv_tok.value);
690: gss_release_buffer(&ms, &send_tok);
691:
692: /* Server will be returning a failed packet after this one */
693: }
694:
695: void
696: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
697: {
698: OM_uint32 maj, min;
699: char *msg;
700: char *lang;
701:
702: maj=packet_get_int();
703: min=packet_get_int();
704: msg=packet_get_string(NULL);
705: lang=packet_get_string(NULL);
706:
707: packet_check_eom();
708:
1.143 stevesk 709: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 710: xfree(msg);
711: xfree(lang);
712: }
713: #endif /* GSSAPI */
1.20 markus 714:
1.1 markus 715: int
1.23 markus 716: userauth_none(Authctxt *authctxt)
717: {
718: /* initial userauth request */
719: packet_start(SSH2_MSG_USERAUTH_REQUEST);
720: packet_put_cstring(authctxt->server_user);
721: packet_put_cstring(authctxt->service);
722: packet_put_cstring(authctxt->method->name);
723: packet_send();
724: return 1;
725: }
726:
727: int
1.20 markus 728: userauth_passwd(Authctxt *authctxt)
1.1 markus 729: {
1.6 markus 730: static int attempt = 0;
1.99 markus 731: char prompt[150];
1.1 markus 732: char *password;
1.6 markus 733:
1.13 todd 734: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 735: return 0;
1.13 todd 736:
1.87 deraadt 737: if (attempt != 1)
1.13 todd 738: error("Permission denied, please try again.");
1.1 markus 739:
1.43 itojun 740: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 741: authctxt->server_user, authctxt->host);
1.1 markus 742: password = read_passphrase(prompt, 0);
743: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 744: packet_put_cstring(authctxt->server_user);
745: packet_put_cstring(authctxt->service);
1.23 markus 746: packet_put_cstring(authctxt->method->name);
1.1 markus 747: packet_put_char(0);
1.49 markus 748: packet_put_cstring(password);
1.1 markus 749: memset(password, 0, strlen(password));
750: xfree(password);
1.85 markus 751: packet_add_padding(64);
1.1 markus 752: packet_send();
1.99 markus 753:
1.104 deraadt 754: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 755: &input_userauth_passwd_changereq);
756:
1.1 markus 757: return 1;
758: }
1.99 markus 759: /*
760: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
761: */
762: void
763: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
764: {
765: Authctxt *authctxt = ctxt;
766: char *info, *lang, *password = NULL, *retype = NULL;
767: char prompt[150];
768:
769: debug2("input_userauth_passwd_changereq");
770:
771: if (authctxt == NULL)
772: fatal("input_userauth_passwd_changereq: "
773: "no authentication context");
774:
775: info = packet_get_string(NULL);
776: lang = packet_get_string(NULL);
777: if (strlen(info) > 0)
1.116 itojun 778: logit("%s", info);
1.99 markus 779: xfree(info);
780: xfree(lang);
781: packet_start(SSH2_MSG_USERAUTH_REQUEST);
782: packet_put_cstring(authctxt->server_user);
783: packet_put_cstring(authctxt->service);
784: packet_put_cstring(authctxt->method->name);
785: packet_put_char(1); /* additional info */
1.104 deraadt 786: snprintf(prompt, sizeof(prompt),
1.99 markus 787: "Enter %.30s@%.128s's old password: ",
788: authctxt->server_user, authctxt->host);
789: password = read_passphrase(prompt, 0);
790: packet_put_cstring(password);
791: memset(password, 0, strlen(password));
792: xfree(password);
793: password = NULL;
794: while (password == NULL) {
1.104 deraadt 795: snprintf(prompt, sizeof(prompt),
1.99 markus 796: "Enter %.30s@%.128s's new password: ",
797: authctxt->server_user, authctxt->host);
798: password = read_passphrase(prompt, RP_ALLOW_EOF);
799: if (password == NULL) {
800: /* bail out */
801: return;
802: }
1.104 deraadt 803: snprintf(prompt, sizeof(prompt),
1.99 markus 804: "Retype %.30s@%.128s's new password: ",
805: authctxt->server_user, authctxt->host);
806: retype = read_passphrase(prompt, 0);
807: if (strcmp(password, retype) != 0) {
808: memset(password, 0, strlen(password));
809: xfree(password);
1.116 itojun 810: logit("Mismatch; try again, EOF to quit.");
1.99 markus 811: password = NULL;
812: }
813: memset(retype, 0, strlen(retype));
814: xfree(retype);
815: }
816: packet_put_cstring(password);
817: memset(password, 0, strlen(password));
818: xfree(password);
819: packet_add_padding(64);
820: packet_send();
1.104 deraadt 821:
822: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 823: &input_userauth_passwd_changereq);
1.117 markus 824: }
825:
826: static int
827: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
828: u_char *data, u_int datalen)
829: {
830: Key *prv;
831: int ret;
1.99 markus 832:
1.117 markus 833: /* the agent supports this key */
834: if (id->ac)
835: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
836: data, datalen));
837: /*
838: * we have already loaded the private key or
839: * the private key is stored in external hardware
840: */
841: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
842: return (key_sign(id->key, sigp, lenp, data, datalen));
843: /* load the private key from the file */
844: if ((prv = load_identity_file(id->filename)) == NULL)
845: return (-1);
846: ret = key_sign(prv, sigp, lenp, data, datalen);
847: key_free(prv);
848: return (ret);
1.51 markus 849: }
850:
1.76 itojun 851: static int
1.117 markus 852: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 853: {
854: Buffer b;
1.32 markus 855: u_char *blob, *signature;
1.96 markus 856: u_int bloblen, slen;
1.120 markus 857: u_int skip = 0;
1.17 markus 858: int ret = -1;
1.23 markus 859: int have_sig = 1;
1.1 markus 860:
1.30 markus 861: debug3("sign_and_send_pubkey");
1.51 markus 862:
1.117 markus 863: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 864: /* we cannot handle this key */
1.30 markus 865: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 866: return 0;
867: }
1.1 markus 868: /* data to be signed */
869: buffer_init(&b);
1.26 markus 870: if (datafellows & SSH_OLD_SESSIONID) {
871: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 872: skip = session_id2_len;
1.26 markus 873: } else {
1.14 markus 874: buffer_put_string(&b, session_id2, session_id2_len);
875: skip = buffer_len(&b);
876: }
1.1 markus 877: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 878: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 879: buffer_put_cstring(&b,
1.30 markus 880: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 881: "ssh-userauth" :
1.20 markus 882: authctxt->service);
1.30 markus 883: if (datafellows & SSH_BUG_PKAUTH) {
884: buffer_put_char(&b, have_sig);
885: } else {
886: buffer_put_cstring(&b, authctxt->method->name);
887: buffer_put_char(&b, have_sig);
1.117 markus 888: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 889: }
1.1 markus 890: buffer_put_string(&b, blob, bloblen);
891:
892: /* generate signature */
1.117 markus 893: ret = identity_sign(id, &signature, &slen,
1.51 markus 894: buffer_ptr(&b), buffer_len(&b));
1.17 markus 895: if (ret == -1) {
896: xfree(blob);
897: buffer_free(&b);
898: return 0;
899: }
1.28 markus 900: #ifdef DEBUG_PK
1.1 markus 901: buffer_dump(&b);
902: #endif
1.30 markus 903: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 904: buffer_clear(&b);
905: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 906: skip = session_id2_len;
1.10 markus 907: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 908: buffer_put_cstring(&b, authctxt->server_user);
909: buffer_put_cstring(&b, authctxt->service);
1.23 markus 910: buffer_put_cstring(&b, authctxt->method->name);
911: buffer_put_char(&b, have_sig);
1.30 markus 912: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 913: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 914: buffer_put_string(&b, blob, bloblen);
915: }
916: xfree(blob);
1.51 markus 917:
1.1 markus 918: /* append signature */
919: buffer_put_string(&b, signature, slen);
920: xfree(signature);
921:
922: /* skip session id and packet type */
1.14 markus 923: if (buffer_len(&b) < skip + 1)
1.20 markus 924: fatal("userauth_pubkey: internal error");
1.14 markus 925: buffer_consume(&b, skip + 1);
1.1 markus 926:
927: /* put remaining data from buffer into packet */
928: packet_start(SSH2_MSG_USERAUTH_REQUEST);
929: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
930: buffer_free(&b);
931: packet_send();
1.17 markus 932:
933: return 1;
1.16 markus 934: }
935:
1.76 itojun 936: static int
1.117 markus 937: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 938: {
1.51 markus 939: u_char *blob;
1.97 markus 940: u_int bloblen, have_sig = 0;
1.20 markus 941:
1.51 markus 942: debug3("send_pubkey_test");
1.16 markus 943:
1.117 markus 944: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 945: /* we cannot handle this key */
946: debug3("send_pubkey_test: cannot handle key");
1.16 markus 947: return 0;
948: }
1.51 markus 949: /* register callback for USERAUTH_PK_OK message */
950: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
951:
952: packet_start(SSH2_MSG_USERAUTH_REQUEST);
953: packet_put_cstring(authctxt->server_user);
954: packet_put_cstring(authctxt->service);
955: packet_put_cstring(authctxt->method->name);
956: packet_put_char(have_sig);
957: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 958: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 959: packet_put_string(blob, bloblen);
960: xfree(blob);
961: packet_send();
962: return 1;
963: }
964:
1.76 itojun 965: static Key *
1.51 markus 966: load_identity_file(char *filename)
967: {
968: Key *private;
969: char prompt[300], *passphrase;
1.56 markus 970: int quit, i;
1.52 markus 971: struct stat st;
1.16 markus 972:
1.52 markus 973: if (stat(filename, &st) < 0) {
974: debug3("no such identity: %s", filename);
975: return NULL;
976: }
1.56 markus 977: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
978: if (private == NULL) {
979: if (options.batch_mode)
1.51 markus 980: return NULL;
1.16 markus 981: snprintf(prompt, sizeof prompt,
1.88 deraadt 982: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 983: for (i = 0; i < options.number_of_password_prompts; i++) {
984: passphrase = read_passphrase(prompt, 0);
985: if (strcmp(passphrase, "") != 0) {
1.56 markus 986: private = key_load_private_type(KEY_UNSPEC, filename,
987: passphrase, NULL);
1.51 markus 988: quit = 0;
1.20 markus 989: } else {
990: debug2("no passphrase given, try next key");
1.51 markus 991: quit = 1;
1.20 markus 992: }
993: memset(passphrase, 0, strlen(passphrase));
994: xfree(passphrase);
1.56 markus 995: if (private != NULL || quit)
1.20 markus 996: break;
997: debug2("bad passphrase given, try again...");
1.16 markus 998: }
999: }
1.51 markus 1000: return private;
1001: }
1002:
1.117 markus 1003: /*
1004: * try keys in the following order:
1005: * 1. agent keys that are found in the config file
1006: * 2. other agent keys
1007: * 3. keys that are only listed in the config file
1008: */
1009: static void
1010: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1011: {
1.117 markus 1012: Identity *id;
1013: Idlist agent, files, *preferred;
1014: Key *key;
1015: AuthenticationConnection *ac;
1016: char *comment;
1017: int i, found;
1.51 markus 1018:
1.117 markus 1019: TAILQ_INIT(&agent); /* keys from the agent */
1020: TAILQ_INIT(&files); /* keys from the config file */
1021: preferred = &authctxt->keys;
1022: TAILQ_INIT(preferred); /* preferred order of keys */
1023:
1024: /* list of keys stored in the filesystem */
1025: for (i = 0; i < options.num_identity_files; i++) {
1026: key = options.identity_keys[i];
1027: if (key && key->type == KEY_RSA1)
1028: continue;
1029: options.identity_keys[i] = NULL;
1030: id = xmalloc(sizeof(*id));
1031: memset(id, 0, sizeof(*id));
1032: id->key = key;
1033: id->filename = xstrdup(options.identity_files[i]);
1034: TAILQ_INSERT_TAIL(&files, id, next);
1035: }
1036: /* list of keys supported by the agent */
1037: if ((ac = ssh_get_authentication_connection())) {
1038: for (key = ssh_get_first_identity(ac, &comment, 2);
1039: key != NULL;
1040: key = ssh_get_next_identity(ac, &comment, 2)) {
1041: found = 0;
1042: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1043: /* agent keys from the config file are preferred */
1.117 markus 1044: if (key_equal(key, id->key)) {
1045: key_free(key);
1046: xfree(comment);
1047: TAILQ_REMOVE(&files, id, next);
1048: TAILQ_INSERT_TAIL(preferred, id, next);
1049: id->ac = ac;
1050: found = 1;
1051: break;
1052: }
1053: }
1.135 markus 1054: if (!found && !options.identities_only) {
1.117 markus 1055: id = xmalloc(sizeof(*id));
1056: memset(id, 0, sizeof(*id));
1057: id->key = key;
1058: id->filename = comment;
1059: id->ac = ac;
1060: TAILQ_INSERT_TAIL(&agent, id, next);
1061: }
1062: }
1063: /* append remaining agent keys */
1064: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1065: TAILQ_REMOVE(&agent, id, next);
1066: TAILQ_INSERT_TAIL(preferred, id, next);
1067: }
1068: authctxt->agent = ac;
1069: }
1070: /* append remaining keys from the config file */
1071: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1072: TAILQ_REMOVE(&files, id, next);
1073: TAILQ_INSERT_TAIL(preferred, id, next);
1074: }
1075: TAILQ_FOREACH(id, preferred, next) {
1076: debug2("key: %s (%p)", id->filename, id->key);
1077: }
1.17 markus 1078: }
1079:
1.117 markus 1080: static void
1081: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1082: {
1.117 markus 1083: Identity *id;
1.51 markus 1084:
1.117 markus 1085: if (authctxt->agent != NULL)
1086: ssh_close_authentication_connection(authctxt->agent);
1087: for (id = TAILQ_FIRST(&authctxt->keys); id;
1088: id = TAILQ_FIRST(&authctxt->keys)) {
1089: TAILQ_REMOVE(&authctxt->keys, id, next);
1090: if (id->key)
1091: key_free(id->key);
1092: if (id->filename)
1093: xfree(id->filename);
1094: xfree(id);
1095: }
1.1 markus 1096: }
1097:
1.20 markus 1098: int
1099: userauth_pubkey(Authctxt *authctxt)
1100: {
1.117 markus 1101: Identity *id;
1.20 markus 1102: int sent = 0;
1103:
1.117 markus 1104: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1105: if (id->tried++)
1106: return (0);
1.127 markus 1107: /* move key to the end of the queue */
1.117 markus 1108: TAILQ_REMOVE(&authctxt->keys, id, next);
1109: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1110: /*
1111: * send a test message if we have the public key. for
1112: * encrypted keys we cannot do this and have to load the
1113: * private key instead
1114: */
1115: if (id->key && id->key->type != KEY_RSA1) {
1116: debug("Offering public key: %s", id->filename);
1117: sent = send_pubkey_test(authctxt, id);
1118: } else if (id->key == NULL) {
1119: debug("Trying private key: %s", id->filename);
1120: id->key = load_identity_file(id->filename);
1121: if (id->key != NULL) {
1122: id->isprivate = 1;
1123: sent = sign_and_send_pubkey(authctxt, id);
1124: key_free(id->key);
1125: id->key = NULL;
1.51 markus 1126: }
1127: }
1.117 markus 1128: if (sent)
1129: return (sent);
1.28 markus 1130: }
1.117 markus 1131: return (0);
1.20 markus 1132: }
1133:
1.23 markus 1134: /*
1135: * Send userauth request message specifying keyboard-interactive method.
1136: */
1137: int
1138: userauth_kbdint(Authctxt *authctxt)
1139: {
1140: static int attempt = 0;
1141:
1142: if (attempt++ >= options.number_of_password_prompts)
1143: return 0;
1.82 markus 1144: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1145: if (attempt > 1 && !authctxt->info_req_seen) {
1146: debug3("userauth_kbdint: disable: no info_req_seen");
1147: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1148: return 0;
1149: }
1.23 markus 1150:
1151: debug2("userauth_kbdint");
1152: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1153: packet_put_cstring(authctxt->server_user);
1154: packet_put_cstring(authctxt->service);
1155: packet_put_cstring(authctxt->method->name);
1156: packet_put_cstring(""); /* lang */
1157: packet_put_cstring(options.kbd_interactive_devices ?
1158: options.kbd_interactive_devices : "");
1159: packet_send();
1160:
1161: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1162: return 1;
1163: }
1164:
1165: /*
1.46 markus 1166: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1167: */
1168: void
1.92 markus 1169: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1170: {
1171: Authctxt *authctxt = ctxt;
1.46 markus 1172: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1173: u_int num_prompts, i;
1.23 markus 1174: int echo = 0;
1175:
1176: debug2("input_userauth_info_req");
1177:
1178: if (authctxt == NULL)
1179: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1180:
1181: authctxt->info_req_seen = 1;
1.23 markus 1182:
1183: name = packet_get_string(NULL);
1184: inst = packet_get_string(NULL);
1185: lang = packet_get_string(NULL);
1186: if (strlen(name) > 0)
1.116 itojun 1187: logit("%s", name);
1.23 markus 1188: if (strlen(inst) > 0)
1.116 itojun 1189: logit("%s", inst);
1.46 markus 1190: xfree(name);
1.23 markus 1191: xfree(inst);
1.46 markus 1192: xfree(lang);
1.23 markus 1193:
1194: num_prompts = packet_get_int();
1195: /*
1196: * Begin to build info response packet based on prompts requested.
1197: * We commit to providing the correct number of responses, so if
1198: * further on we run into a problem that prevents this, we have to
1199: * be sure and clean this up and send a correct error response.
1200: */
1201: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1202: packet_put_int(num_prompts);
1203:
1.73 markus 1204: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1205: for (i = 0; i < num_prompts; i++) {
1206: prompt = packet_get_string(NULL);
1207: echo = packet_get_char();
1208:
1.77 markus 1209: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1210:
1.49 markus 1211: packet_put_cstring(response);
1.23 markus 1212: memset(response, 0, strlen(response));
1213: xfree(response);
1214: xfree(prompt);
1215: }
1.90 markus 1216: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1217:
1.85 markus 1218: packet_add_padding(64);
1.23 markus 1219: packet_send();
1.68 markus 1220: }
1221:
1.100 markus 1222: static int
1.105 deraadt 1223: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1224: u_char *data, u_int datalen)
1225: {
1226: Buffer b;
1.101 markus 1227: struct stat st;
1.100 markus 1228: pid_t pid;
1.103 markus 1229: int to[2], from[2], status, version = 2;
1.100 markus 1230:
1.109 markus 1231: debug2("ssh_keysign called");
1.100 markus 1232:
1.101 markus 1233: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1234: error("ssh_keysign: no installed: %s", strerror(errno));
1235: return -1;
1236: }
1.100 markus 1237: if (fflush(stdout) != 0)
1238: error("ssh_keysign: fflush: %s", strerror(errno));
1239: if (pipe(to) < 0) {
1240: error("ssh_keysign: pipe: %s", strerror(errno));
1241: return -1;
1242: }
1243: if (pipe(from) < 0) {
1244: error("ssh_keysign: pipe: %s", strerror(errno));
1245: return -1;
1246: }
1247: if ((pid = fork()) < 0) {
1248: error("ssh_keysign: fork: %s", strerror(errno));
1249: return -1;
1250: }
1251: if (pid == 0) {
1252: seteuid(getuid());
1253: setuid(getuid());
1254: close(from[0]);
1255: if (dup2(from[1], STDOUT_FILENO) < 0)
1256: fatal("ssh_keysign: dup2: %s", strerror(errno));
1257: close(to[1]);
1258: if (dup2(to[0], STDIN_FILENO) < 0)
1259: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1260: close(from[1]);
1261: close(to[0]);
1.102 markus 1262: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1263: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1264: strerror(errno));
1265: }
1266: close(from[1]);
1267: close(to[0]);
1268:
1269: buffer_init(&b);
1.103 markus 1270: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1271: buffer_put_string(&b, data, datalen);
1.131 djm 1272: if (ssh_msg_send(to[1], version, &b) == -1)
1273: fatal("ssh_keysign: couldn't send request");
1.100 markus 1274:
1.110 djm 1275: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1276: error("ssh_keysign: no reply");
1.134 markus 1277: buffer_free(&b);
1.100 markus 1278: return -1;
1279: }
1.101 markus 1280: close(from[0]);
1281: close(to[1]);
1282:
1.103 markus 1283: while (waitpid(pid, &status, 0) < 0)
1284: if (errno != EINTR)
1285: break;
1.101 markus 1286:
1.100 markus 1287: if (buffer_get_char(&b) != version) {
1.101 markus 1288: error("ssh_keysign: bad version");
1.134 markus 1289: buffer_free(&b);
1.100 markus 1290: return -1;
1291: }
1292: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1293: buffer_free(&b);
1.100 markus 1294:
1295: return 0;
1296: }
1297:
1.68 markus 1298: int
1299: userauth_hostbased(Authctxt *authctxt)
1300: {
1301: Key *private = NULL;
1.100 markus 1302: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1303: Buffer b;
1304: u_char *signature, *blob;
1305: char *chost, *pkalg, *p;
1.72 markus 1306: const char *service;
1.68 markus 1307: u_int blen, slen;
1.71 markus 1308: int ok, i, len, found = 0;
1.68 markus 1309:
1310: /* check for a useful key */
1.100 markus 1311: for (i = 0; i < sensitive->nkeys; i++) {
1312: private = sensitive->keys[i];
1.68 markus 1313: if (private && private->type != KEY_RSA1) {
1314: found = 1;
1315: /* we take and free the key */
1.100 markus 1316: sensitive->keys[i] = NULL;
1.68 markus 1317: break;
1318: }
1319: }
1320: if (!found) {
1.109 markus 1321: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1322: return 0;
1323: }
1324: if (key_to_blob(private, &blob, &blen) == 0) {
1325: key_free(private);
1326: return 0;
1327: }
1.84 markus 1328: /* figure out a name for the client host */
1329: p = get_local_name(packet_get_connection_in());
1330: if (p == NULL) {
1331: error("userauth_hostbased: cannot get local ipaddr/name");
1332: key_free(private);
1333: return 0;
1334: }
1335: len = strlen(p) + 2;
1336: chost = xmalloc(len);
1337: strlcpy(chost, p, len);
1338: strlcat(chost, ".", len);
1339: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1340: xfree(p);
1.84 markus 1341:
1.72 markus 1342: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1343: authctxt->service;
1.68 markus 1344: pkalg = xstrdup(key_ssh_name(private));
1345: buffer_init(&b);
1346: /* construct data */
1.72 markus 1347: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1348: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1349: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1350: buffer_put_cstring(&b, service);
1.68 markus 1351: buffer_put_cstring(&b, authctxt->method->name);
1352: buffer_put_cstring(&b, pkalg);
1353: buffer_put_string(&b, blob, blen);
1354: buffer_put_cstring(&b, chost);
1355: buffer_put_cstring(&b, authctxt->local_user);
1356: #ifdef DEBUG_PK
1357: buffer_dump(&b);
1358: #endif
1.100 markus 1359: if (sensitive->external_keysign)
1360: ok = ssh_keysign(private, &signature, &slen,
1361: buffer_ptr(&b), buffer_len(&b));
1362: else
1363: ok = key_sign(private, &signature, &slen,
1364: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1365: key_free(private);
1366: buffer_free(&b);
1367: if (ok != 0) {
1368: error("key_sign failed");
1369: xfree(chost);
1370: xfree(pkalg);
1371: return 0;
1372: }
1373: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1374: packet_put_cstring(authctxt->server_user);
1375: packet_put_cstring(authctxt->service);
1376: packet_put_cstring(authctxt->method->name);
1377: packet_put_cstring(pkalg);
1378: packet_put_string(blob, blen);
1379: packet_put_cstring(chost);
1380: packet_put_cstring(authctxt->local_user);
1381: packet_put_string(signature, slen);
1382: memset(signature, 's', slen);
1383: xfree(signature);
1384: xfree(chost);
1385: xfree(pkalg);
1386:
1387: packet_send();
1388: return 1;
1.23 markus 1389: }
1.20 markus 1390:
1391: /* find auth method */
1392:
1393: /*
1394: * given auth method name, if configurable options permit this method fill
1395: * in auth_ident field and return true, otherwise return false.
1396: */
1.76 itojun 1397: static int
1.20 markus 1398: authmethod_is_enabled(Authmethod *method)
1399: {
1400: if (method == NULL)
1401: return 0;
1402: /* return false if options indicate this method is disabled */
1403: if (method->enabled == NULL || *method->enabled == 0)
1404: return 0;
1405: /* return false if batch mode is enabled but method needs interactive mode */
1406: if (method->batch_flag != NULL && *method->batch_flag != 0)
1407: return 0;
1408: return 1;
1409: }
1410:
1.76 itojun 1411: static Authmethod *
1.20 markus 1412: authmethod_lookup(const char *name)
1.1 markus 1413: {
1.20 markus 1414: Authmethod *method = NULL;
1415: if (name != NULL)
1416: for (method = authmethods; method->name != NULL; method++)
1417: if (strcmp(name, method->name) == 0)
1418: return method;
1419: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1420: return NULL;
1421: }
1.1 markus 1422:
1.53 markus 1423: /* XXX internal state */
1424: static Authmethod *current = NULL;
1425: static char *supported = NULL;
1426: static char *preferred = NULL;
1.105 deraadt 1427:
1.20 markus 1428: /*
1429: * Given the authentication method list sent by the server, return the
1430: * next method we should try. If the server initially sends a nil list,
1.67 markus 1431: * use a built-in default list.
1.41 stevesk 1432: */
1.76 itojun 1433: static Authmethod *
1.20 markus 1434: authmethod_get(char *authlist)
1435: {
1.53 markus 1436: char *name = NULL;
1.97 markus 1437: u_int next;
1.41 stevesk 1438:
1.20 markus 1439: /* Use a suitable default if we're passed a nil list. */
1440: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1441: authlist = options.preferred_authentications;
1.20 markus 1442:
1.53 markus 1443: if (supported == NULL || strcmp(authlist, supported) != 0) {
1444: debug3("start over, passed a different list %s", authlist);
1445: if (supported != NULL)
1446: xfree(supported);
1447: supported = xstrdup(authlist);
1448: preferred = options.preferred_authentications;
1449: debug3("preferred %s", preferred);
1450: current = NULL;
1451: } else if (current != NULL && authmethod_is_enabled(current))
1452: return current;
1.20 markus 1453:
1.53 markus 1454: for (;;) {
1455: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1456: debug("No more authentication methods to try.");
1.53 markus 1457: current = NULL;
1458: return NULL;
1459: }
1460: preferred += next;
1.23 markus 1461: debug3("authmethod_lookup %s", name);
1.53 markus 1462: debug3("remaining preferred: %s", preferred);
1463: if ((current = authmethod_lookup(name)) != NULL &&
1464: authmethod_is_enabled(current)) {
1.23 markus 1465: debug3("authmethod_is_enabled %s", name);
1.109 markus 1466: debug("Next authentication method: %s", name);
1.53 markus 1467: return current;
1.23 markus 1468: }
1.1 markus 1469: }
1.53 markus 1470: }
1.1 markus 1471:
1.79 stevesk 1472: static char *
1.53 markus 1473: authmethods_get(void)
1474: {
1475: Authmethod *method = NULL;
1.93 markus 1476: Buffer b;
1477: char *list;
1.27 provos 1478:
1.93 markus 1479: buffer_init(&b);
1.53 markus 1480: for (method = authmethods; method->name != NULL; method++) {
1481: if (authmethod_is_enabled(method)) {
1.93 markus 1482: if (buffer_len(&b) > 0)
1483: buffer_append(&b, ",", 1);
1484: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1485: }
1486: }
1.93 markus 1487: buffer_append(&b, "\0", 1);
1488: list = xstrdup(buffer_ptr(&b));
1489: buffer_free(&b);
1490: return list;
1.1 markus 1491: }