Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.152
1.152 ! dtucker 1: /* $OpenBSD: sshconnect2.c,v 1.151 2006/03/25 13:17:02 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: *
14: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24: */
25:
26: #include "includes.h"
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:
1.148 djm 516: if (!ok) {
517: ssh_gssapi_delete_ctx(&gssctxt);
1.139 djm 518: return 0;
1.148 djm 519: }
1.121 markus 520:
521: authctxt->methoddata=(void *)gssctxt;
522:
523: packet_start(SSH2_MSG_USERAUTH_REQUEST);
524: packet_put_cstring(authctxt->server_user);
525: packet_put_cstring(authctxt->service);
526: packet_put_cstring(authctxt->method->name);
527:
528: packet_put_int(1);
529:
1.129 markus 530: packet_put_int((gss_supported->elements[mech].length) + 2);
531: packet_put_char(SSH_GSS_OIDTYPE);
532: packet_put_char(gss_supported->elements[mech].length);
533: packet_put_raw(gss_supported->elements[mech].elements,
534: gss_supported->elements[mech].length);
1.121 markus 535:
536: packet_send();
537:
538: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
539: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
540: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
541: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
542:
543: mech++; /* Move along to next candidate */
544:
545: return 1;
546: }
547:
1.130 markus 548: static OM_uint32
549: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
550: {
551: Authctxt *authctxt = ctxt;
552: Gssctxt *gssctxt = authctxt->methoddata;
553: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 554: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
555: gss_buffer_desc gssbuf;
1.132 markus 556: OM_uint32 status, ms, flags;
557: Buffer b;
1.133 djm 558:
1.130 markus 559: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 560: recv_tok, &send_tok, &flags);
1.130 markus 561:
562: if (send_tok.length > 0) {
563: if (GSS_ERROR(status))
564: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
565: else
566: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 567:
1.130 markus 568: packet_put_string(send_tok.value, send_tok.length);
569: packet_send();
570: gss_release_buffer(&ms, &send_tok);
571: }
1.133 djm 572:
1.130 markus 573: if (status == GSS_S_COMPLETE) {
1.132 markus 574: /* send either complete or MIC, depending on mechanism */
575: if (!(flags & GSS_C_INTEG_FLAG)) {
576: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
577: packet_send();
578: } else {
579: ssh_gssapi_buildmic(&b, authctxt->server_user,
580: authctxt->service, "gssapi-with-mic");
581:
582: gssbuf.value = buffer_ptr(&b);
583: gssbuf.length = buffer_len(&b);
1.133 djm 584:
1.132 markus 585: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 586:
1.132 markus 587: if (!GSS_ERROR(status)) {
588: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
589: packet_put_string(mic.value, mic.length);
1.133 djm 590:
1.132 markus 591: packet_send();
592: }
1.133 djm 593:
1.132 markus 594: buffer_free(&b);
595: gss_release_buffer(&ms, &mic);
1.133 djm 596: }
1.130 markus 597: }
1.133 djm 598:
1.130 markus 599: return status;
600: }
601:
1.121 markus 602: void
603: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
604: {
605: Authctxt *authctxt = ctxt;
606: Gssctxt *gssctxt;
607: int oidlen;
608: char *oidv;
609:
610: if (authctxt == NULL)
611: fatal("input_gssapi_response: no authentication context");
612: gssctxt = authctxt->methoddata;
613:
614: /* Setup our OID */
615: oidv = packet_get_string(&oidlen);
616:
1.129 markus 617: if (oidlen <= 2 ||
618: oidv[0] != SSH_GSS_OIDTYPE ||
619: oidv[1] != oidlen - 2) {
1.130 markus 620: xfree(oidv);
1.129 markus 621: debug("Badly encoded mechanism OID received");
622: userauth(authctxt, NULL);
623: return;
1.121 markus 624: }
1.129 markus 625:
626: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
627: fatal("Server returned different OID than expected");
1.121 markus 628:
629: packet_check_eom();
630:
631: xfree(oidv);
632:
1.130 markus 633: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 634: /* Start again with next method on list */
635: debug("Trying to start again");
636: userauth(authctxt, NULL);
637: return;
638: }
639: }
640:
641: void
642: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
643: {
644: Authctxt *authctxt = ctxt;
645: gss_buffer_desc recv_tok;
1.130 markus 646: OM_uint32 status;
1.121 markus 647: u_int slen;
648:
649: if (authctxt == NULL)
650: fatal("input_gssapi_response: no authentication context");
651:
652: recv_tok.value = packet_get_string(&slen);
653: recv_tok.length = slen; /* safe typecast */
654:
655: packet_check_eom();
656:
1.130 markus 657: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 658:
659: xfree(recv_tok.value);
660:
661: if (GSS_ERROR(status)) {
662: /* Start again with the next method in the list */
663: userauth(authctxt, NULL);
664: return;
665: }
666: }
667:
668: void
669: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
670: {
671: Authctxt *authctxt = ctxt;
672: Gssctxt *gssctxt;
673: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
674: gss_buffer_desc recv_tok;
675: OM_uint32 status, ms;
1.123 deraadt 676: u_int len;
1.121 markus 677:
678: if (authctxt == NULL)
679: fatal("input_gssapi_response: no authentication context");
680: gssctxt = authctxt->methoddata;
681:
1.123 deraadt 682: recv_tok.value = packet_get_string(&len);
683: recv_tok.length = len;
1.121 markus 684:
685: packet_check_eom();
686:
687: /* Stick it into GSSAPI and see what it says */
688: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 689: &recv_tok, &send_tok, NULL);
1.121 markus 690:
691: xfree(recv_tok.value);
692: gss_release_buffer(&ms, &send_tok);
693:
694: /* Server will be returning a failed packet after this one */
695: }
696:
697: void
698: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
699: {
700: OM_uint32 maj, min;
701: char *msg;
702: char *lang;
703:
704: maj=packet_get_int();
705: min=packet_get_int();
706: msg=packet_get_string(NULL);
707: lang=packet_get_string(NULL);
708:
709: packet_check_eom();
710:
1.143 stevesk 711: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 712: xfree(msg);
713: xfree(lang);
714: }
715: #endif /* GSSAPI */
1.20 markus 716:
1.1 markus 717: int
1.23 markus 718: userauth_none(Authctxt *authctxt)
719: {
720: /* initial userauth request */
721: packet_start(SSH2_MSG_USERAUTH_REQUEST);
722: packet_put_cstring(authctxt->server_user);
723: packet_put_cstring(authctxt->service);
724: packet_put_cstring(authctxt->method->name);
725: packet_send();
726: return 1;
727: }
728:
729: int
1.20 markus 730: userauth_passwd(Authctxt *authctxt)
1.1 markus 731: {
1.6 markus 732: static int attempt = 0;
1.99 markus 733: char prompt[150];
1.1 markus 734: char *password;
1.6 markus 735:
1.13 todd 736: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 737: return 0;
1.13 todd 738:
1.87 deraadt 739: if (attempt != 1)
1.13 todd 740: error("Permission denied, please try again.");
1.1 markus 741:
1.43 itojun 742: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 743: authctxt->server_user, authctxt->host);
1.1 markus 744: password = read_passphrase(prompt, 0);
745: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 746: packet_put_cstring(authctxt->server_user);
747: packet_put_cstring(authctxt->service);
1.23 markus 748: packet_put_cstring(authctxt->method->name);
1.1 markus 749: packet_put_char(0);
1.49 markus 750: packet_put_cstring(password);
1.1 markus 751: memset(password, 0, strlen(password));
752: xfree(password);
1.85 markus 753: packet_add_padding(64);
1.1 markus 754: packet_send();
1.99 markus 755:
1.104 deraadt 756: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 757: &input_userauth_passwd_changereq);
758:
1.1 markus 759: return 1;
760: }
1.99 markus 761: /*
762: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
763: */
764: void
765: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
766: {
767: Authctxt *authctxt = ctxt;
768: char *info, *lang, *password = NULL, *retype = NULL;
769: char prompt[150];
770:
771: debug2("input_userauth_passwd_changereq");
772:
773: if (authctxt == NULL)
774: fatal("input_userauth_passwd_changereq: "
775: "no authentication context");
776:
777: info = packet_get_string(NULL);
778: lang = packet_get_string(NULL);
779: if (strlen(info) > 0)
1.116 itojun 780: logit("%s", info);
1.99 markus 781: xfree(info);
782: xfree(lang);
783: packet_start(SSH2_MSG_USERAUTH_REQUEST);
784: packet_put_cstring(authctxt->server_user);
785: packet_put_cstring(authctxt->service);
786: packet_put_cstring(authctxt->method->name);
787: packet_put_char(1); /* additional info */
1.104 deraadt 788: snprintf(prompt, sizeof(prompt),
1.99 markus 789: "Enter %.30s@%.128s's old password: ",
790: authctxt->server_user, authctxt->host);
791: password = read_passphrase(prompt, 0);
792: packet_put_cstring(password);
793: memset(password, 0, strlen(password));
794: xfree(password);
795: password = NULL;
796: while (password == NULL) {
1.104 deraadt 797: snprintf(prompt, sizeof(prompt),
1.99 markus 798: "Enter %.30s@%.128s's new password: ",
799: authctxt->server_user, authctxt->host);
800: password = read_passphrase(prompt, RP_ALLOW_EOF);
801: if (password == NULL) {
802: /* bail out */
803: return;
804: }
1.104 deraadt 805: snprintf(prompt, sizeof(prompt),
1.99 markus 806: "Retype %.30s@%.128s's new password: ",
807: authctxt->server_user, authctxt->host);
808: retype = read_passphrase(prompt, 0);
809: if (strcmp(password, retype) != 0) {
810: memset(password, 0, strlen(password));
811: xfree(password);
1.116 itojun 812: logit("Mismatch; try again, EOF to quit.");
1.99 markus 813: password = NULL;
814: }
815: memset(retype, 0, strlen(retype));
816: xfree(retype);
817: }
818: packet_put_cstring(password);
819: memset(password, 0, strlen(password));
820: xfree(password);
821: packet_add_padding(64);
822: packet_send();
1.104 deraadt 823:
824: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 825: &input_userauth_passwd_changereq);
1.117 markus 826: }
827:
828: static int
829: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
830: u_char *data, u_int datalen)
831: {
832: Key *prv;
833: int ret;
1.99 markus 834:
1.117 markus 835: /* the agent supports this key */
836: if (id->ac)
837: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
838: data, datalen));
839: /*
840: * we have already loaded the private key or
841: * the private key is stored in external hardware
842: */
843: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
844: return (key_sign(id->key, sigp, lenp, data, datalen));
845: /* load the private key from the file */
846: if ((prv = load_identity_file(id->filename)) == NULL)
847: return (-1);
848: ret = key_sign(prv, sigp, lenp, data, datalen);
849: key_free(prv);
850: return (ret);
1.51 markus 851: }
852:
1.76 itojun 853: static int
1.117 markus 854: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 855: {
856: Buffer b;
1.32 markus 857: u_char *blob, *signature;
1.96 markus 858: u_int bloblen, slen;
1.120 markus 859: u_int skip = 0;
1.17 markus 860: int ret = -1;
1.23 markus 861: int have_sig = 1;
1.1 markus 862:
1.30 markus 863: debug3("sign_and_send_pubkey");
1.51 markus 864:
1.117 markus 865: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 866: /* we cannot handle this key */
1.30 markus 867: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 868: return 0;
869: }
1.1 markus 870: /* data to be signed */
871: buffer_init(&b);
1.26 markus 872: if (datafellows & SSH_OLD_SESSIONID) {
873: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 874: skip = session_id2_len;
1.26 markus 875: } else {
1.14 markus 876: buffer_put_string(&b, session_id2, session_id2_len);
877: skip = buffer_len(&b);
878: }
1.1 markus 879: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 880: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 881: buffer_put_cstring(&b,
1.30 markus 882: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 883: "ssh-userauth" :
1.20 markus 884: authctxt->service);
1.30 markus 885: if (datafellows & SSH_BUG_PKAUTH) {
886: buffer_put_char(&b, have_sig);
887: } else {
888: buffer_put_cstring(&b, authctxt->method->name);
889: buffer_put_char(&b, have_sig);
1.117 markus 890: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 891: }
1.1 markus 892: buffer_put_string(&b, blob, bloblen);
893:
894: /* generate signature */
1.117 markus 895: ret = identity_sign(id, &signature, &slen,
1.51 markus 896: buffer_ptr(&b), buffer_len(&b));
1.17 markus 897: if (ret == -1) {
898: xfree(blob);
899: buffer_free(&b);
900: return 0;
901: }
1.28 markus 902: #ifdef DEBUG_PK
1.1 markus 903: buffer_dump(&b);
904: #endif
1.30 markus 905: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 906: buffer_clear(&b);
907: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 908: skip = session_id2_len;
1.10 markus 909: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 910: buffer_put_cstring(&b, authctxt->server_user);
911: buffer_put_cstring(&b, authctxt->service);
1.23 markus 912: buffer_put_cstring(&b, authctxt->method->name);
913: buffer_put_char(&b, have_sig);
1.30 markus 914: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 915: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 916: buffer_put_string(&b, blob, bloblen);
917: }
918: xfree(blob);
1.51 markus 919:
1.1 markus 920: /* append signature */
921: buffer_put_string(&b, signature, slen);
922: xfree(signature);
923:
924: /* skip session id and packet type */
1.14 markus 925: if (buffer_len(&b) < skip + 1)
1.20 markus 926: fatal("userauth_pubkey: internal error");
1.14 markus 927: buffer_consume(&b, skip + 1);
1.1 markus 928:
929: /* put remaining data from buffer into packet */
930: packet_start(SSH2_MSG_USERAUTH_REQUEST);
931: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
932: buffer_free(&b);
933: packet_send();
1.17 markus 934:
935: return 1;
1.16 markus 936: }
937:
1.76 itojun 938: static int
1.117 markus 939: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 940: {
1.51 markus 941: u_char *blob;
1.97 markus 942: u_int bloblen, have_sig = 0;
1.20 markus 943:
1.51 markus 944: debug3("send_pubkey_test");
1.16 markus 945:
1.117 markus 946: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 947: /* we cannot handle this key */
948: debug3("send_pubkey_test: cannot handle key");
1.16 markus 949: return 0;
950: }
1.51 markus 951: /* register callback for USERAUTH_PK_OK message */
952: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
953:
954: packet_start(SSH2_MSG_USERAUTH_REQUEST);
955: packet_put_cstring(authctxt->server_user);
956: packet_put_cstring(authctxt->service);
957: packet_put_cstring(authctxt->method->name);
958: packet_put_char(have_sig);
959: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 960: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 961: packet_put_string(blob, bloblen);
962: xfree(blob);
963: packet_send();
964: return 1;
965: }
966:
1.76 itojun 967: static Key *
1.51 markus 968: load_identity_file(char *filename)
969: {
970: Key *private;
971: char prompt[300], *passphrase;
1.152 ! dtucker 972: int perm_ok, quit, i;
1.52 markus 973: struct stat st;
1.16 markus 974:
1.52 markus 975: if (stat(filename, &st) < 0) {
976: debug3("no such identity: %s", filename);
977: return NULL;
978: }
1.152 ! dtucker 979: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
! 980: if (!perm_ok)
! 981: return NULL;
1.56 markus 982: if (private == NULL) {
983: if (options.batch_mode)
1.51 markus 984: return NULL;
1.16 markus 985: snprintf(prompt, sizeof prompt,
1.88 deraadt 986: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 987: for (i = 0; i < options.number_of_password_prompts; i++) {
988: passphrase = read_passphrase(prompt, 0);
989: if (strcmp(passphrase, "") != 0) {
1.152 ! dtucker 990: private = key_load_private_type(KEY_UNSPEC,
! 991: filename, passphrase, NULL, NULL);
1.51 markus 992: quit = 0;
1.20 markus 993: } else {
994: debug2("no passphrase given, try next key");
1.51 markus 995: quit = 1;
1.20 markus 996: }
997: memset(passphrase, 0, strlen(passphrase));
998: xfree(passphrase);
1.56 markus 999: if (private != NULL || quit)
1.20 markus 1000: break;
1001: debug2("bad passphrase given, try again...");
1.16 markus 1002: }
1003: }
1.51 markus 1004: return private;
1005: }
1006:
1.117 markus 1007: /*
1008: * try keys in the following order:
1009: * 1. agent keys that are found in the config file
1010: * 2. other agent keys
1011: * 3. keys that are only listed in the config file
1012: */
1013: static void
1014: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1015: {
1.117 markus 1016: Identity *id;
1017: Idlist agent, files, *preferred;
1018: Key *key;
1019: AuthenticationConnection *ac;
1020: char *comment;
1021: int i, found;
1.51 markus 1022:
1.117 markus 1023: TAILQ_INIT(&agent); /* keys from the agent */
1024: TAILQ_INIT(&files); /* keys from the config file */
1025: preferred = &authctxt->keys;
1026: TAILQ_INIT(preferred); /* preferred order of keys */
1027:
1028: /* list of keys stored in the filesystem */
1029: for (i = 0; i < options.num_identity_files; i++) {
1030: key = options.identity_keys[i];
1031: if (key && key->type == KEY_RSA1)
1032: continue;
1033: options.identity_keys[i] = NULL;
1.150 djm 1034: id = xcalloc(1, sizeof(*id));
1.117 markus 1035: id->key = key;
1036: id->filename = xstrdup(options.identity_files[i]);
1037: TAILQ_INSERT_TAIL(&files, id, next);
1038: }
1039: /* list of keys supported by the agent */
1040: if ((ac = ssh_get_authentication_connection())) {
1041: for (key = ssh_get_first_identity(ac, &comment, 2);
1042: key != NULL;
1043: key = ssh_get_next_identity(ac, &comment, 2)) {
1044: found = 0;
1045: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1046: /* agent keys from the config file are preferred */
1.117 markus 1047: if (key_equal(key, id->key)) {
1048: key_free(key);
1049: xfree(comment);
1050: TAILQ_REMOVE(&files, id, next);
1051: TAILQ_INSERT_TAIL(preferred, id, next);
1052: id->ac = ac;
1053: found = 1;
1054: break;
1055: }
1056: }
1.135 markus 1057: if (!found && !options.identities_only) {
1.150 djm 1058: id = xcalloc(1, sizeof(*id));
1.117 markus 1059: id->key = key;
1060: id->filename = comment;
1061: id->ac = ac;
1062: TAILQ_INSERT_TAIL(&agent, id, next);
1063: }
1064: }
1065: /* append remaining agent keys */
1066: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1067: TAILQ_REMOVE(&agent, id, next);
1068: TAILQ_INSERT_TAIL(preferred, id, next);
1069: }
1070: authctxt->agent = ac;
1071: }
1072: /* append remaining keys from the config file */
1073: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1074: TAILQ_REMOVE(&files, id, next);
1075: TAILQ_INSERT_TAIL(preferred, id, next);
1076: }
1077: TAILQ_FOREACH(id, preferred, next) {
1078: debug2("key: %s (%p)", id->filename, id->key);
1079: }
1.17 markus 1080: }
1081:
1.117 markus 1082: static void
1083: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1084: {
1.117 markus 1085: Identity *id;
1.51 markus 1086:
1.117 markus 1087: if (authctxt->agent != NULL)
1088: ssh_close_authentication_connection(authctxt->agent);
1089: for (id = TAILQ_FIRST(&authctxt->keys); id;
1090: id = TAILQ_FIRST(&authctxt->keys)) {
1091: TAILQ_REMOVE(&authctxt->keys, id, next);
1092: if (id->key)
1093: key_free(id->key);
1094: if (id->filename)
1095: xfree(id->filename);
1096: xfree(id);
1097: }
1.1 markus 1098: }
1099:
1.20 markus 1100: int
1101: userauth_pubkey(Authctxt *authctxt)
1102: {
1.117 markus 1103: Identity *id;
1.20 markus 1104: int sent = 0;
1105:
1.117 markus 1106: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1107: if (id->tried++)
1108: return (0);
1.127 markus 1109: /* move key to the end of the queue */
1.117 markus 1110: TAILQ_REMOVE(&authctxt->keys, id, next);
1111: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1112: /*
1113: * send a test message if we have the public key. for
1114: * encrypted keys we cannot do this and have to load the
1115: * private key instead
1116: */
1117: if (id->key && id->key->type != KEY_RSA1) {
1118: debug("Offering public key: %s", id->filename);
1119: sent = send_pubkey_test(authctxt, id);
1120: } else if (id->key == NULL) {
1121: debug("Trying private key: %s", id->filename);
1122: id->key = load_identity_file(id->filename);
1123: if (id->key != NULL) {
1124: id->isprivate = 1;
1125: sent = sign_and_send_pubkey(authctxt, id);
1126: key_free(id->key);
1127: id->key = NULL;
1.51 markus 1128: }
1129: }
1.117 markus 1130: if (sent)
1131: return (sent);
1.28 markus 1132: }
1.117 markus 1133: return (0);
1.20 markus 1134: }
1135:
1.23 markus 1136: /*
1137: * Send userauth request message specifying keyboard-interactive method.
1138: */
1139: int
1140: userauth_kbdint(Authctxt *authctxt)
1141: {
1142: static int attempt = 0;
1143:
1144: if (attempt++ >= options.number_of_password_prompts)
1145: return 0;
1.82 markus 1146: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1147: if (attempt > 1 && !authctxt->info_req_seen) {
1148: debug3("userauth_kbdint: disable: no info_req_seen");
1149: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1150: return 0;
1151: }
1.23 markus 1152:
1153: debug2("userauth_kbdint");
1154: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1155: packet_put_cstring(authctxt->server_user);
1156: packet_put_cstring(authctxt->service);
1157: packet_put_cstring(authctxt->method->name);
1158: packet_put_cstring(""); /* lang */
1159: packet_put_cstring(options.kbd_interactive_devices ?
1160: options.kbd_interactive_devices : "");
1161: packet_send();
1162:
1163: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1164: return 1;
1165: }
1166:
1167: /*
1.46 markus 1168: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1169: */
1170: void
1.92 markus 1171: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1172: {
1173: Authctxt *authctxt = ctxt;
1.46 markus 1174: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1175: u_int num_prompts, i;
1.23 markus 1176: int echo = 0;
1177:
1178: debug2("input_userauth_info_req");
1179:
1180: if (authctxt == NULL)
1181: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1182:
1183: authctxt->info_req_seen = 1;
1.23 markus 1184:
1185: name = packet_get_string(NULL);
1186: inst = packet_get_string(NULL);
1187: lang = packet_get_string(NULL);
1188: if (strlen(name) > 0)
1.116 itojun 1189: logit("%s", name);
1.23 markus 1190: if (strlen(inst) > 0)
1.116 itojun 1191: logit("%s", inst);
1.46 markus 1192: xfree(name);
1.23 markus 1193: xfree(inst);
1.46 markus 1194: xfree(lang);
1.23 markus 1195:
1196: num_prompts = packet_get_int();
1197: /*
1198: * Begin to build info response packet based on prompts requested.
1199: * We commit to providing the correct number of responses, so if
1200: * further on we run into a problem that prevents this, we have to
1201: * be sure and clean this up and send a correct error response.
1202: */
1203: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1204: packet_put_int(num_prompts);
1205:
1.73 markus 1206: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1207: for (i = 0; i < num_prompts; i++) {
1208: prompt = packet_get_string(NULL);
1209: echo = packet_get_char();
1210:
1.77 markus 1211: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1212:
1.49 markus 1213: packet_put_cstring(response);
1.23 markus 1214: memset(response, 0, strlen(response));
1215: xfree(response);
1216: xfree(prompt);
1217: }
1.90 markus 1218: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1219:
1.85 markus 1220: packet_add_padding(64);
1.23 markus 1221: packet_send();
1.68 markus 1222: }
1223:
1.100 markus 1224: static int
1.105 deraadt 1225: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1226: u_char *data, u_int datalen)
1227: {
1228: Buffer b;
1.101 markus 1229: struct stat st;
1.100 markus 1230: pid_t pid;
1.103 markus 1231: int to[2], from[2], status, version = 2;
1.100 markus 1232:
1.109 markus 1233: debug2("ssh_keysign called");
1.100 markus 1234:
1.101 markus 1235: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1236: error("ssh_keysign: no installed: %s", strerror(errno));
1237: return -1;
1238: }
1.100 markus 1239: if (fflush(stdout) != 0)
1240: error("ssh_keysign: fflush: %s", strerror(errno));
1241: if (pipe(to) < 0) {
1242: error("ssh_keysign: pipe: %s", strerror(errno));
1243: return -1;
1244: }
1245: if (pipe(from) < 0) {
1246: error("ssh_keysign: pipe: %s", strerror(errno));
1247: return -1;
1248: }
1249: if ((pid = fork()) < 0) {
1250: error("ssh_keysign: fork: %s", strerror(errno));
1251: return -1;
1252: }
1253: if (pid == 0) {
1254: seteuid(getuid());
1255: setuid(getuid());
1256: close(from[0]);
1257: if (dup2(from[1], STDOUT_FILENO) < 0)
1258: fatal("ssh_keysign: dup2: %s", strerror(errno));
1259: close(to[1]);
1260: if (dup2(to[0], STDIN_FILENO) < 0)
1261: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1262: close(from[1]);
1263: close(to[0]);
1.102 markus 1264: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1265: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1266: strerror(errno));
1267: }
1268: close(from[1]);
1269: close(to[0]);
1270:
1271: buffer_init(&b);
1.103 markus 1272: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1273: buffer_put_string(&b, data, datalen);
1.131 djm 1274: if (ssh_msg_send(to[1], version, &b) == -1)
1275: fatal("ssh_keysign: couldn't send request");
1.100 markus 1276:
1.110 djm 1277: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1278: error("ssh_keysign: no reply");
1.134 markus 1279: buffer_free(&b);
1.100 markus 1280: return -1;
1281: }
1.101 markus 1282: close(from[0]);
1283: close(to[1]);
1284:
1.103 markus 1285: while (waitpid(pid, &status, 0) < 0)
1286: if (errno != EINTR)
1287: break;
1.101 markus 1288:
1.100 markus 1289: if (buffer_get_char(&b) != version) {
1.101 markus 1290: error("ssh_keysign: bad version");
1.134 markus 1291: buffer_free(&b);
1.100 markus 1292: return -1;
1293: }
1294: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1295: buffer_free(&b);
1.100 markus 1296:
1297: return 0;
1298: }
1299:
1.68 markus 1300: int
1301: userauth_hostbased(Authctxt *authctxt)
1302: {
1303: Key *private = NULL;
1.100 markus 1304: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1305: Buffer b;
1306: u_char *signature, *blob;
1307: char *chost, *pkalg, *p;
1.72 markus 1308: const char *service;
1.68 markus 1309: u_int blen, slen;
1.71 markus 1310: int ok, i, len, found = 0;
1.68 markus 1311:
1312: /* check for a useful key */
1.100 markus 1313: for (i = 0; i < sensitive->nkeys; i++) {
1314: private = sensitive->keys[i];
1.68 markus 1315: if (private && private->type != KEY_RSA1) {
1316: found = 1;
1317: /* we take and free the key */
1.100 markus 1318: sensitive->keys[i] = NULL;
1.68 markus 1319: break;
1320: }
1321: }
1322: if (!found) {
1.109 markus 1323: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1324: return 0;
1325: }
1326: if (key_to_blob(private, &blob, &blen) == 0) {
1327: key_free(private);
1328: return 0;
1329: }
1.84 markus 1330: /* figure out a name for the client host */
1331: p = get_local_name(packet_get_connection_in());
1332: if (p == NULL) {
1333: error("userauth_hostbased: cannot get local ipaddr/name");
1334: key_free(private);
1.148 djm 1335: xfree(blob);
1.84 markus 1336: return 0;
1337: }
1338: len = strlen(p) + 2;
1.150 djm 1339: xasprintf(&chost, "%s.", p);
1.84 markus 1340: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1341: xfree(p);
1.84 markus 1342:
1.72 markus 1343: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1344: authctxt->service;
1.68 markus 1345: pkalg = xstrdup(key_ssh_name(private));
1346: buffer_init(&b);
1347: /* construct data */
1.72 markus 1348: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1349: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1350: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1351: buffer_put_cstring(&b, service);
1.68 markus 1352: buffer_put_cstring(&b, authctxt->method->name);
1353: buffer_put_cstring(&b, pkalg);
1354: buffer_put_string(&b, blob, blen);
1355: buffer_put_cstring(&b, chost);
1356: buffer_put_cstring(&b, authctxt->local_user);
1357: #ifdef DEBUG_PK
1358: buffer_dump(&b);
1359: #endif
1.100 markus 1360: if (sensitive->external_keysign)
1361: ok = ssh_keysign(private, &signature, &slen,
1362: buffer_ptr(&b), buffer_len(&b));
1363: else
1364: ok = key_sign(private, &signature, &slen,
1365: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1366: key_free(private);
1367: buffer_free(&b);
1368: if (ok != 0) {
1369: error("key_sign failed");
1370: xfree(chost);
1371: xfree(pkalg);
1.148 djm 1372: xfree(blob);
1.68 markus 1373: return 0;
1374: }
1375: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1376: packet_put_cstring(authctxt->server_user);
1377: packet_put_cstring(authctxt->service);
1378: packet_put_cstring(authctxt->method->name);
1379: packet_put_cstring(pkalg);
1380: packet_put_string(blob, blen);
1381: packet_put_cstring(chost);
1382: packet_put_cstring(authctxt->local_user);
1383: packet_put_string(signature, slen);
1384: memset(signature, 's', slen);
1385: xfree(signature);
1386: xfree(chost);
1387: xfree(pkalg);
1.148 djm 1388: xfree(blob);
1.68 markus 1389:
1390: packet_send();
1391: return 1;
1.23 markus 1392: }
1.20 markus 1393:
1394: /* find auth method */
1395:
1396: /*
1397: * given auth method name, if configurable options permit this method fill
1398: * in auth_ident field and return true, otherwise return false.
1399: */
1.76 itojun 1400: static int
1.20 markus 1401: authmethod_is_enabled(Authmethod *method)
1402: {
1403: if (method == NULL)
1404: return 0;
1405: /* return false if options indicate this method is disabled */
1406: if (method->enabled == NULL || *method->enabled == 0)
1407: return 0;
1408: /* return false if batch mode is enabled but method needs interactive mode */
1409: if (method->batch_flag != NULL && *method->batch_flag != 0)
1410: return 0;
1411: return 1;
1412: }
1413:
1.76 itojun 1414: static Authmethod *
1.20 markus 1415: authmethod_lookup(const char *name)
1.1 markus 1416: {
1.20 markus 1417: Authmethod *method = NULL;
1418: if (name != NULL)
1419: for (method = authmethods; method->name != NULL; method++)
1420: if (strcmp(name, method->name) == 0)
1421: return method;
1422: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1423: return NULL;
1424: }
1.1 markus 1425:
1.53 markus 1426: /* XXX internal state */
1427: static Authmethod *current = NULL;
1428: static char *supported = NULL;
1429: static char *preferred = NULL;
1.105 deraadt 1430:
1.20 markus 1431: /*
1432: * Given the authentication method list sent by the server, return the
1433: * next method we should try. If the server initially sends a nil list,
1.67 markus 1434: * use a built-in default list.
1.41 stevesk 1435: */
1.76 itojun 1436: static Authmethod *
1.20 markus 1437: authmethod_get(char *authlist)
1438: {
1.53 markus 1439: char *name = NULL;
1.97 markus 1440: u_int next;
1.41 stevesk 1441:
1.20 markus 1442: /* Use a suitable default if we're passed a nil list. */
1443: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1444: authlist = options.preferred_authentications;
1.20 markus 1445:
1.53 markus 1446: if (supported == NULL || strcmp(authlist, supported) != 0) {
1447: debug3("start over, passed a different list %s", authlist);
1448: if (supported != NULL)
1449: xfree(supported);
1450: supported = xstrdup(authlist);
1451: preferred = options.preferred_authentications;
1452: debug3("preferred %s", preferred);
1453: current = NULL;
1454: } else if (current != NULL && authmethod_is_enabled(current))
1455: return current;
1.20 markus 1456:
1.53 markus 1457: for (;;) {
1458: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1459: debug("No more authentication methods to try.");
1.53 markus 1460: current = NULL;
1461: return NULL;
1462: }
1463: preferred += next;
1.23 markus 1464: debug3("authmethod_lookup %s", name);
1.53 markus 1465: debug3("remaining preferred: %s", preferred);
1466: if ((current = authmethod_lookup(name)) != NULL &&
1467: authmethod_is_enabled(current)) {
1.23 markus 1468: debug3("authmethod_is_enabled %s", name);
1.109 markus 1469: debug("Next authentication method: %s", name);
1.53 markus 1470: return current;
1.23 markus 1471: }
1.1 markus 1472: }
1.53 markus 1473: }
1.1 markus 1474:
1.79 stevesk 1475: static char *
1.53 markus 1476: authmethods_get(void)
1477: {
1478: Authmethod *method = NULL;
1.93 markus 1479: Buffer b;
1480: char *list;
1.27 provos 1481:
1.93 markus 1482: buffer_init(&b);
1.53 markus 1483: for (method = authmethods; method->name != NULL; method++) {
1484: if (authmethod_is_enabled(method)) {
1.93 markus 1485: if (buffer_len(&b) > 0)
1486: buffer_append(&b, ",", 1);
1487: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1488: }
1489: }
1.93 markus 1490: buffer_append(&b, "\0", 1);
1491: list = xstrdup(buffer_ptr(&b));
1492: buffer_free(&b);
1493: return list;
1.1 markus 1494: }
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