Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.164
1.164 ! jolan 1: /* $OpenBSD: sshconnect2.c,v 1.163 2007/05/17 20:48:13 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:
1.145 stevesk 26: #include <sys/types.h>
1.160 deraadt 27: #include <sys/socket.h>
1.145 stevesk 28: #include <sys/wait.h>
1.144 stevesk 29: #include <sys/queue.h>
1.146 stevesk 30: #include <sys/stat.h>
1.156 stevesk 31:
32: #include <errno.h>
1.164 ! jolan 33: #include <netdb.h>
1.159 stevesk 34: #include <stdio.h>
1.158 stevesk 35: #include <string.h>
1.160 deraadt 36: #include <signal.h>
37: #include <pwd.h>
1.157 stevesk 38: #include <unistd.h>
1.1 markus 39:
1.160 deraadt 40: #include "xmalloc.h"
1.1 markus 41: #include "ssh.h"
1.37 markus 42: #include "ssh2.h"
1.1 markus 43: #include "buffer.h"
44: #include "packet.h"
45: #include "compat.h"
1.37 markus 46: #include "cipher.h"
1.160 deraadt 47: #include "key.h"
1.1 markus 48: #include "kex.h"
49: #include "myproposal.h"
50: #include "sshconnect.h"
51: #include "authfile.h"
1.57 provos 52: #include "dh.h"
1.17 markus 53: #include "authfd.h"
1.37 markus 54: #include "log.h"
55: #include "readconf.h"
1.137 djm 56: #include "misc.h"
1.53 markus 57: #include "match.h"
1.61 markus 58: #include "dispatch.h"
1.68 markus 59: #include "canohost.h"
1.100 markus 60: #include "msg.h"
61: #include "pathnames.h"
1.154 markus 62: #include "uidswap.h"
1.22 provos 63:
1.121 markus 64: #ifdef GSSAPI
65: #include "ssh-gss.h"
66: #endif
67:
1.1 markus 68: /* import */
69: extern char *client_version_string;
70: extern char *server_version_string;
71: extern Options options;
72:
73: /*
74: * SSH2 key exchange
75: */
76:
1.32 markus 77: u_char *session_id2 = NULL;
1.120 markus 78: u_int session_id2_len = 0;
1.1 markus 79:
1.61 markus 80: char *xxx_host;
81: struct sockaddr *xxx_hostaddr;
82:
1.63 markus 83: Kex *xxx_kex = NULL;
84:
1.76 itojun 85: static int
1.75 markus 86: verify_host_key_callback(Key *hostkey)
1.61 markus 87: {
1.75 markus 88: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 89: fatal("Host key verification failed.");
1.61 markus 90: return 0;
91: }
92:
1.1 markus 93: void
1.22 provos 94: ssh_kex2(char *host, struct sockaddr *hostaddr)
95: {
96: Kex *kex;
1.61 markus 97:
98: xxx_host = host;
99: xxx_hostaddr = hostaddr;
1.22 provos 100:
1.29 markus 101: if (options.ciphers == (char *)-1) {
1.116 itojun 102: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 103: options.ciphers = NULL;
1.24 markus 104: }
1.22 provos 105: if (options.ciphers != NULL) {
106: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
107: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
108: }
1.60 stevesk 109: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
110: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
111: myproposal[PROPOSAL_ENC_ALGS_STOC] =
112: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 113: if (options.compression) {
1.47 markus 114: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 115: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 116: } else {
1.47 markus 117: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 118: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 119: }
120: if (options.macs != NULL) {
121: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
122: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 123: }
1.70 markus 124: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 125: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 126: options.hostkeyalgorithms;
1.115 markus 127:
128: if (options.rekey_limit)
129: packet_set_rekey_limit(options.rekey_limit);
1.22 provos 130:
1.65 markus 131: /* start key exchange */
1.64 markus 132: kex = kex_setup(myproposal);
1.111 markus 133: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 134: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 135: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 136: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.61 markus 137: kex->client_version_string=client_version_string;
138: kex->server_version_string=server_version_string;
1.75 markus 139: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 140:
141: xxx_kex = kex;
1.22 provos 142:
1.66 markus 143: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 144:
145: session_id2 = kex->session_id;
146: session_id2_len = kex->session_id_len;
1.22 provos 147:
148: #ifdef DEBUG_KEXDH
149: /* send 1st encrypted/maced/compressed message */
150: packet_start(SSH2_MSG_IGNORE);
151: packet_put_cstring("markus");
152: packet_send();
153: packet_write_wait();
154: #endif
1.1 markus 155: }
1.11 markus 156:
1.1 markus 157: /*
158: * Authenticate user
159: */
1.20 markus 160:
161: typedef struct Authctxt Authctxt;
162: typedef struct Authmethod Authmethod;
1.117 markus 163: typedef struct identity Identity;
164: typedef struct idlist Idlist;
1.20 markus 165:
1.117 markus 166: struct identity {
167: TAILQ_ENTRY(identity) next;
168: AuthenticationConnection *ac; /* set if agent supports key */
169: Key *key; /* public/private key */
170: char *filename; /* comment for agent-only keys */
171: int tried;
172: int isprivate; /* key points to the private key */
173: };
174: TAILQ_HEAD(idlist, identity);
1.20 markus 175:
176: struct Authctxt {
177: const char *server_user;
1.68 markus 178: const char *local_user;
1.20 markus 179: const char *host;
180: const char *service;
1.23 markus 181: Authmethod *method;
1.20 markus 182: int success;
1.51 markus 183: char *authlist;
1.68 markus 184: /* pubkey */
1.117 markus 185: Idlist keys;
1.68 markus 186: AuthenticationConnection *agent;
187: /* hostbased */
1.100 markus 188: Sensitive *sensitive;
1.82 markus 189: /* kbd-interactive */
190: int info_req_seen;
1.121 markus 191: /* generic */
192: void *methoddata;
1.20 markus 193: };
194: struct Authmethod {
195: char *name; /* string to compare against server's list */
196: int (*userauth)(Authctxt *authctxt);
197: int *enabled; /* flag in option struct that enables method */
198: int *batch_flag; /* flag in option struct that disables method */
199: };
200:
1.92 markus 201: void input_userauth_success(int, u_int32_t, void *);
202: void input_userauth_failure(int, u_int32_t, void *);
203: void input_userauth_banner(int, u_int32_t, void *);
204: void input_userauth_error(int, u_int32_t, void *);
205: void input_userauth_info_req(int, u_int32_t, void *);
206: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 207: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 208:
209: int userauth_none(Authctxt *);
210: int userauth_pubkey(Authctxt *);
211: int userauth_passwd(Authctxt *);
212: int userauth_kbdint(Authctxt *);
213: int userauth_hostbased(Authctxt *);
1.118 markus 214: int userauth_kerberos(Authctxt *);
1.20 markus 215:
1.121 markus 216: #ifdef GSSAPI
217: int userauth_gssapi(Authctxt *authctxt);
218: void input_gssapi_response(int type, u_int32_t, void *);
219: void input_gssapi_token(int type, u_int32_t, void *);
220: void input_gssapi_hash(int type, u_int32_t, void *);
221: void input_gssapi_error(int, u_int32_t, void *);
222: void input_gssapi_errtok(int, u_int32_t, void *);
223: #endif
224:
1.86 itojun 225: void userauth(Authctxt *, char *);
1.51 markus 226:
1.117 markus 227: static int sign_and_send_pubkey(Authctxt *, Identity *);
228: static void pubkey_prepare(Authctxt *);
229: static void pubkey_cleanup(Authctxt *);
230: static Key *load_identity_file(char *);
1.76 itojun 231:
232: static Authmethod *authmethod_get(char *authlist);
233: static Authmethod *authmethod_lookup(const char *name);
234: static char *authmethods_get(void);
1.20 markus 235:
236: Authmethod authmethods[] = {
1.121 markus 237: #ifdef GSSAPI
1.132 markus 238: {"gssapi-with-mic",
1.121 markus 239: userauth_gssapi,
240: &options.gss_authentication,
241: NULL},
242: #endif
1.81 markus 243: {"hostbased",
244: userauth_hostbased,
245: &options.hostbased_authentication,
246: NULL},
1.20 markus 247: {"publickey",
248: userauth_pubkey,
1.28 markus 249: &options.pubkey_authentication,
1.20 markus 250: NULL},
1.81 markus 251: {"keyboard-interactive",
252: userauth_kbdint,
253: &options.kbd_interactive_authentication,
254: &options.batch_mode},
1.20 markus 255: {"password",
256: userauth_passwd,
257: &options.password_authentication,
1.23 markus 258: &options.batch_mode},
259: {"none",
260: userauth_none,
261: NULL,
262: NULL},
1.20 markus 263: {NULL, NULL, NULL, NULL}
264: };
265:
266: void
1.68 markus 267: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 268: Sensitive *sensitive)
1.20 markus 269: {
270: Authctxt authctxt;
271: int type;
1.39 markus 272:
1.73 markus 273: if (options.challenge_response_authentication)
1.39 markus 274: options.kbd_interactive_authentication = 1;
1.20 markus 275:
276: packet_start(SSH2_MSG_SERVICE_REQUEST);
277: packet_put_cstring("ssh-userauth");
278: packet_send();
1.108 markus 279: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 280: packet_write_wait();
1.91 markus 281: type = packet_read();
1.108 markus 282: if (type != SSH2_MSG_SERVICE_ACCEPT)
283: fatal("Server denied authentication request: %d", type);
1.20 markus 284: if (packet_remaining() > 0) {
1.91 markus 285: char *reply = packet_get_string(NULL);
1.108 markus 286: debug2("service_accept: %s", reply);
1.20 markus 287: xfree(reply);
288: } else {
1.109 markus 289: debug2("buggy server: service_accept w/o service");
1.20 markus 290: }
1.90 markus 291: packet_check_eom();
1.108 markus 292: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 293:
1.53 markus 294: if (options.preferred_authentications == NULL)
295: options.preferred_authentications = authmethods_get();
296:
1.20 markus 297: /* setup authentication context */
1.82 markus 298: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 299: pubkey_prepare(&authctxt);
1.20 markus 300: authctxt.server_user = server_user;
1.68 markus 301: authctxt.local_user = local_user;
1.20 markus 302: authctxt.host = host;
303: authctxt.service = "ssh-connection"; /* service name */
304: authctxt.success = 0;
1.23 markus 305: authctxt.method = authmethod_lookup("none");
1.51 markus 306: authctxt.authlist = NULL;
1.121 markus 307: authctxt.methoddata = NULL;
1.100 markus 308: authctxt.sensitive = sensitive;
1.82 markus 309: authctxt.info_req_seen = 0;
1.23 markus 310: if (authctxt.method == NULL)
311: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 312:
313: /* initial userauth request */
1.23 markus 314: userauth_none(&authctxt);
1.20 markus 315:
1.65 markus 316: dispatch_init(&input_userauth_error);
1.20 markus 317: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
318: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 319: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 320: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
321:
1.117 markus 322: pubkey_cleanup(&authctxt);
1.119 markus 323: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
324:
1.109 markus 325: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 326: }
1.119 markus 327:
1.20 markus 328: void
1.51 markus 329: userauth(Authctxt *authctxt, char *authlist)
330: {
1.121 markus 331: if (authctxt->methoddata) {
332: xfree(authctxt->methoddata);
333: authctxt->methoddata = NULL;
334: }
1.51 markus 335: if (authlist == NULL) {
336: authlist = authctxt->authlist;
337: } else {
338: if (authctxt->authlist)
339: xfree(authctxt->authlist);
340: authctxt->authlist = authlist;
341: }
342: for (;;) {
343: Authmethod *method = authmethod_get(authlist);
344: if (method == NULL)
345: fatal("Permission denied (%s).", authlist);
346: authctxt->method = method;
1.119 markus 347:
348: /* reset the per method handler */
349: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
350: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
351:
352: /* and try new method */
1.51 markus 353: if (method->userauth(authctxt) != 0) {
354: debug2("we sent a %s packet, wait for reply", method->name);
355: break;
356: } else {
357: debug2("we did not send a packet, disable method");
358: method->enabled = NULL;
359: }
360: }
361: }
1.105 deraadt 362:
1.51 markus 363: void
1.92 markus 364: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 365: {
1.35 markus 366: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 367: "type %d", type);
1.35 markus 368: }
1.105 deraadt 369:
1.35 markus 370: void
1.92 markus 371: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 372: {
373: char *msg, *lang;
1.126 deraadt 374:
1.35 markus 375: debug3("input_userauth_banner");
376: msg = packet_get_string(NULL);
377: lang = packet_get_string(NULL);
1.162 dtucker 378: if (options.log_level >= SYSLOG_LEVEL_INFO)
1.125 dtucker 379: fprintf(stderr, "%s", msg);
1.35 markus 380: xfree(msg);
381: xfree(lang);
1.20 markus 382: }
1.105 deraadt 383:
1.20 markus 384: void
1.92 markus 385: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 386: {
387: Authctxt *authctxt = ctxt;
388: if (authctxt == NULL)
389: fatal("input_userauth_success: no authentication context");
1.126 deraadt 390: if (authctxt->authlist) {
1.51 markus 391: xfree(authctxt->authlist);
1.126 deraadt 392: authctxt->authlist = NULL;
393: }
394: if (authctxt->methoddata) {
1.121 markus 395: xfree(authctxt->methoddata);
1.126 deraadt 396: authctxt->methoddata = NULL;
397: }
1.20 markus 398: authctxt->success = 1; /* break out */
399: }
1.105 deraadt 400:
1.20 markus 401: void
1.92 markus 402: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 403: {
404: Authctxt *authctxt = ctxt;
405: char *authlist = NULL;
406: int partial;
407:
408: if (authctxt == NULL)
409: fatal("input_userauth_failure: no authentication context");
410:
1.23 markus 411: authlist = packet_get_string(NULL);
1.20 markus 412: partial = packet_get_char();
1.90 markus 413: packet_check_eom();
1.20 markus 414:
415: if (partial != 0)
1.116 itojun 416: logit("Authenticated with partial success.");
1.109 markus 417: debug("Authentications that can continue: %s", authlist);
1.20 markus 418:
1.51 markus 419: userauth(authctxt, authlist);
420: }
421: void
1.92 markus 422: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 423: {
424: Authctxt *authctxt = ctxt;
425: Key *key = NULL;
1.117 markus 426: Identity *id = NULL;
1.51 markus 427: Buffer b;
1.96 markus 428: int pktype, sent = 0;
429: u_int alen, blen;
430: char *pkalg, *fp;
431: u_char *pkblob;
1.51 markus 432:
433: if (authctxt == NULL)
434: fatal("input_userauth_pk_ok: no authentication context");
435: if (datafellows & SSH_BUG_PKOK) {
436: /* this is similar to SSH_BUG_PKAUTH */
437: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
438: pkblob = packet_get_string(&blen);
439: buffer_init(&b);
440: buffer_append(&b, pkblob, blen);
441: pkalg = buffer_get_string(&b, &alen);
442: buffer_free(&b);
443: } else {
444: pkalg = packet_get_string(&alen);
445: pkblob = packet_get_string(&blen);
446: }
1.90 markus 447: packet_check_eom();
1.51 markus 448:
1.117 markus 449: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 450:
1.117 markus 451: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
452: debug("unknown pkalg %s", pkalg);
453: goto done;
454: }
455: if ((key = key_from_blob(pkblob, blen)) == NULL) {
456: debug("no key from blob. pkalg %s", pkalg);
457: goto done;
458: }
459: if (key->type != pktype) {
460: error("input_userauth_pk_ok: type mismatch "
461: "for decoded key (received %d, expected %d)",
462: key->type, pktype);
463: goto done;
464: }
465: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
466: debug2("input_userauth_pk_ok: fp %s", fp);
467: xfree(fp);
468:
1.127 markus 469: /*
470: * search keys in the reverse order, because last candidate has been
471: * moved to the end of the queue. this also avoids confusion by
472: * duplicate keys
473: */
1.136 henning 474: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 475: if (key_equal(key, id->key)) {
476: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 477: break;
478: }
1.117 markus 479: }
480: done:
1.51 markus 481: if (key != NULL)
482: key_free(key);
483: xfree(pkalg);
484: xfree(pkblob);
485:
1.106 deraadt 486: /* try another method if we did not send a packet */
1.51 markus 487: if (sent == 0)
488: userauth(authctxt, NULL);
1.20 markus 489: }
1.121 markus 490:
491: #ifdef GSSAPI
1.133 djm 492: int
1.121 markus 493: userauth_gssapi(Authctxt *authctxt)
494: {
495: Gssctxt *gssctxt = NULL;
1.128 avsm 496: static gss_OID_set gss_supported = NULL;
1.139 djm 497: static u_int mech = 0;
1.121 markus 498: OM_uint32 min;
499: int ok = 0;
500:
501: /* Try one GSSAPI method at a time, rather than sending them all at
502: * once. */
503:
1.128 avsm 504: if (gss_supported == NULL)
505: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 506:
507: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 508: while (mech < gss_supported->count && !ok) {
1.121 markus 509: /* My DER encoding requires length<128 */
1.128 avsm 510: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 511: ssh_gssapi_check_mechanism(&gssctxt,
512: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 513: ok = 1; /* Mechanism works */
514: } else {
515: mech++;
516: }
517: }
518:
1.161 djm 519: if (!ok)
1.139 djm 520: return 0;
1.121 markus 521:
522: authctxt->methoddata=(void *)gssctxt;
523:
524: packet_start(SSH2_MSG_USERAUTH_REQUEST);
525: packet_put_cstring(authctxt->server_user);
526: packet_put_cstring(authctxt->service);
527: packet_put_cstring(authctxt->method->name);
528:
529: packet_put_int(1);
530:
1.129 markus 531: packet_put_int((gss_supported->elements[mech].length) + 2);
532: packet_put_char(SSH_GSS_OIDTYPE);
533: packet_put_char(gss_supported->elements[mech].length);
534: packet_put_raw(gss_supported->elements[mech].elements,
535: gss_supported->elements[mech].length);
1.121 markus 536:
537: packet_send();
538:
539: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
540: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
541: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
542: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
543:
544: mech++; /* Move along to next candidate */
545:
546: return 1;
547: }
548:
1.130 markus 549: static OM_uint32
550: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
551: {
552: Authctxt *authctxt = ctxt;
553: Gssctxt *gssctxt = authctxt->methoddata;
554: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 555: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
556: gss_buffer_desc gssbuf;
1.132 markus 557: OM_uint32 status, ms, flags;
558: Buffer b;
1.133 djm 559:
1.130 markus 560: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 561: recv_tok, &send_tok, &flags);
1.130 markus 562:
563: if (send_tok.length > 0) {
564: if (GSS_ERROR(status))
565: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
566: else
567: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 568:
1.130 markus 569: packet_put_string(send_tok.value, send_tok.length);
570: packet_send();
571: gss_release_buffer(&ms, &send_tok);
572: }
1.133 djm 573:
1.130 markus 574: if (status == GSS_S_COMPLETE) {
1.132 markus 575: /* send either complete or MIC, depending on mechanism */
576: if (!(flags & GSS_C_INTEG_FLAG)) {
577: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
578: packet_send();
579: } else {
580: ssh_gssapi_buildmic(&b, authctxt->server_user,
581: authctxt->service, "gssapi-with-mic");
582:
583: gssbuf.value = buffer_ptr(&b);
584: gssbuf.length = buffer_len(&b);
1.133 djm 585:
1.132 markus 586: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 587:
1.132 markus 588: if (!GSS_ERROR(status)) {
589: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
590: packet_put_string(mic.value, mic.length);
1.133 djm 591:
1.132 markus 592: packet_send();
593: }
1.133 djm 594:
1.132 markus 595: buffer_free(&b);
596: gss_release_buffer(&ms, &mic);
1.133 djm 597: }
1.130 markus 598: }
1.133 djm 599:
1.130 markus 600: return status;
601: }
602:
1.121 markus 603: void
604: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
605: {
606: Authctxt *authctxt = ctxt;
607: Gssctxt *gssctxt;
608: int oidlen;
609: char *oidv;
610:
611: if (authctxt == NULL)
612: fatal("input_gssapi_response: no authentication context");
613: gssctxt = authctxt->methoddata;
614:
615: /* Setup our OID */
616: oidv = packet_get_string(&oidlen);
617:
1.129 markus 618: if (oidlen <= 2 ||
619: oidv[0] != SSH_GSS_OIDTYPE ||
620: oidv[1] != oidlen - 2) {
1.130 markus 621: xfree(oidv);
1.129 markus 622: debug("Badly encoded mechanism OID received");
623: userauth(authctxt, NULL);
624: return;
1.121 markus 625: }
1.129 markus 626:
627: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
628: fatal("Server returned different OID than expected");
1.121 markus 629:
630: packet_check_eom();
631:
632: xfree(oidv);
633:
1.130 markus 634: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 635: /* Start again with next method on list */
636: debug("Trying to start again");
637: userauth(authctxt, NULL);
638: return;
639: }
640: }
641:
642: void
643: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
644: {
645: Authctxt *authctxt = ctxt;
646: gss_buffer_desc recv_tok;
1.130 markus 647: OM_uint32 status;
1.121 markus 648: u_int slen;
649:
650: if (authctxt == NULL)
651: fatal("input_gssapi_response: no authentication context");
652:
653: recv_tok.value = packet_get_string(&slen);
654: recv_tok.length = slen; /* safe typecast */
655:
656: packet_check_eom();
657:
1.130 markus 658: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 659:
660: xfree(recv_tok.value);
661:
662: if (GSS_ERROR(status)) {
663: /* Start again with the next method in the list */
664: userauth(authctxt, NULL);
665: return;
666: }
667: }
668:
669: void
670: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
671: {
672: Authctxt *authctxt = ctxt;
673: Gssctxt *gssctxt;
674: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
675: gss_buffer_desc recv_tok;
676: OM_uint32 status, ms;
1.123 deraadt 677: u_int len;
1.121 markus 678:
679: if (authctxt == NULL)
680: fatal("input_gssapi_response: no authentication context");
681: gssctxt = authctxt->methoddata;
682:
1.123 deraadt 683: recv_tok.value = packet_get_string(&len);
684: recv_tok.length = len;
1.121 markus 685:
686: packet_check_eom();
687:
688: /* Stick it into GSSAPI and see what it says */
689: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 690: &recv_tok, &send_tok, NULL);
1.121 markus 691:
692: xfree(recv_tok.value);
693: gss_release_buffer(&ms, &send_tok);
694:
695: /* Server will be returning a failed packet after this one */
696: }
697:
698: void
699: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
700: {
701: OM_uint32 maj, min;
702: char *msg;
703: char *lang;
704:
705: maj=packet_get_int();
706: min=packet_get_int();
707: msg=packet_get_string(NULL);
708: lang=packet_get_string(NULL);
709:
710: packet_check_eom();
711:
1.143 stevesk 712: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 713: xfree(msg);
714: xfree(lang);
715: }
716: #endif /* GSSAPI */
1.20 markus 717:
1.1 markus 718: int
1.23 markus 719: userauth_none(Authctxt *authctxt)
720: {
721: /* initial userauth request */
722: packet_start(SSH2_MSG_USERAUTH_REQUEST);
723: packet_put_cstring(authctxt->server_user);
724: packet_put_cstring(authctxt->service);
725: packet_put_cstring(authctxt->method->name);
726: packet_send();
727: return 1;
728: }
729:
730: int
1.20 markus 731: userauth_passwd(Authctxt *authctxt)
1.1 markus 732: {
1.6 markus 733: static int attempt = 0;
1.99 markus 734: char prompt[150];
1.1 markus 735: char *password;
1.6 markus 736:
1.13 todd 737: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 738: return 0;
1.13 todd 739:
1.87 deraadt 740: if (attempt != 1)
1.13 todd 741: error("Permission denied, please try again.");
1.1 markus 742:
1.43 itojun 743: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 744: authctxt->server_user, authctxt->host);
1.1 markus 745: password = read_passphrase(prompt, 0);
746: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 747: packet_put_cstring(authctxt->server_user);
748: packet_put_cstring(authctxt->service);
1.23 markus 749: packet_put_cstring(authctxt->method->name);
1.1 markus 750: packet_put_char(0);
1.49 markus 751: packet_put_cstring(password);
1.1 markus 752: memset(password, 0, strlen(password));
753: xfree(password);
1.85 markus 754: packet_add_padding(64);
1.1 markus 755: packet_send();
1.99 markus 756:
1.104 deraadt 757: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 758: &input_userauth_passwd_changereq);
759:
1.1 markus 760: return 1;
761: }
1.99 markus 762: /*
763: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
764: */
765: void
1.153 djm 766: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 767: {
768: Authctxt *authctxt = ctxt;
769: char *info, *lang, *password = NULL, *retype = NULL;
770: char prompt[150];
771:
772: debug2("input_userauth_passwd_changereq");
773:
774: if (authctxt == NULL)
775: fatal("input_userauth_passwd_changereq: "
776: "no authentication context");
777:
778: info = packet_get_string(NULL);
779: lang = packet_get_string(NULL);
780: if (strlen(info) > 0)
1.116 itojun 781: logit("%s", info);
1.99 markus 782: xfree(info);
783: xfree(lang);
784: packet_start(SSH2_MSG_USERAUTH_REQUEST);
785: packet_put_cstring(authctxt->server_user);
786: packet_put_cstring(authctxt->service);
787: packet_put_cstring(authctxt->method->name);
788: packet_put_char(1); /* additional info */
1.104 deraadt 789: snprintf(prompt, sizeof(prompt),
1.99 markus 790: "Enter %.30s@%.128s's old password: ",
791: authctxt->server_user, authctxt->host);
792: password = read_passphrase(prompt, 0);
793: packet_put_cstring(password);
794: memset(password, 0, strlen(password));
795: xfree(password);
796: password = NULL;
797: while (password == NULL) {
1.104 deraadt 798: snprintf(prompt, sizeof(prompt),
1.99 markus 799: "Enter %.30s@%.128s's new password: ",
800: authctxt->server_user, authctxt->host);
801: password = read_passphrase(prompt, RP_ALLOW_EOF);
802: if (password == NULL) {
803: /* bail out */
804: return;
805: }
1.104 deraadt 806: snprintf(prompt, sizeof(prompt),
1.99 markus 807: "Retype %.30s@%.128s's new password: ",
808: authctxt->server_user, authctxt->host);
809: retype = read_passphrase(prompt, 0);
810: if (strcmp(password, retype) != 0) {
811: memset(password, 0, strlen(password));
812: xfree(password);
1.116 itojun 813: logit("Mismatch; try again, EOF to quit.");
1.99 markus 814: password = NULL;
815: }
816: memset(retype, 0, strlen(retype));
817: xfree(retype);
818: }
819: packet_put_cstring(password);
820: memset(password, 0, strlen(password));
821: xfree(password);
822: packet_add_padding(64);
823: packet_send();
1.104 deraadt 824:
825: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 826: &input_userauth_passwd_changereq);
1.117 markus 827: }
828:
829: static int
830: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
831: u_char *data, u_int datalen)
832: {
833: Key *prv;
834: int ret;
1.99 markus 835:
1.117 markus 836: /* the agent supports this key */
837: if (id->ac)
838: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
839: data, datalen));
840: /*
841: * we have already loaded the private key or
842: * the private key is stored in external hardware
843: */
844: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
845: return (key_sign(id->key, sigp, lenp, data, datalen));
846: /* load the private key from the file */
847: if ((prv = load_identity_file(id->filename)) == NULL)
848: return (-1);
849: ret = key_sign(prv, sigp, lenp, data, datalen);
850: key_free(prv);
851: return (ret);
1.51 markus 852: }
853:
1.76 itojun 854: static int
1.117 markus 855: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 856: {
857: Buffer b;
1.32 markus 858: u_char *blob, *signature;
1.96 markus 859: u_int bloblen, slen;
1.120 markus 860: u_int skip = 0;
1.17 markus 861: int ret = -1;
1.23 markus 862: int have_sig = 1;
1.1 markus 863:
1.30 markus 864: debug3("sign_and_send_pubkey");
1.51 markus 865:
1.117 markus 866: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 867: /* we cannot handle this key */
1.30 markus 868: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 869: return 0;
870: }
1.1 markus 871: /* data to be signed */
872: buffer_init(&b);
1.26 markus 873: if (datafellows & SSH_OLD_SESSIONID) {
874: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 875: skip = session_id2_len;
1.26 markus 876: } else {
1.14 markus 877: buffer_put_string(&b, session_id2, session_id2_len);
878: skip = buffer_len(&b);
879: }
1.1 markus 880: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 881: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 882: buffer_put_cstring(&b,
1.30 markus 883: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 884: "ssh-userauth" :
1.20 markus 885: authctxt->service);
1.30 markus 886: if (datafellows & SSH_BUG_PKAUTH) {
887: buffer_put_char(&b, have_sig);
888: } else {
889: buffer_put_cstring(&b, authctxt->method->name);
890: buffer_put_char(&b, have_sig);
1.117 markus 891: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 892: }
1.1 markus 893: buffer_put_string(&b, blob, bloblen);
894:
895: /* generate signature */
1.117 markus 896: ret = identity_sign(id, &signature, &slen,
1.51 markus 897: buffer_ptr(&b), buffer_len(&b));
1.17 markus 898: if (ret == -1) {
899: xfree(blob);
900: buffer_free(&b);
901: return 0;
902: }
1.28 markus 903: #ifdef DEBUG_PK
1.1 markus 904: buffer_dump(&b);
905: #endif
1.30 markus 906: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 907: buffer_clear(&b);
908: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 909: skip = session_id2_len;
1.10 markus 910: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 911: buffer_put_cstring(&b, authctxt->server_user);
912: buffer_put_cstring(&b, authctxt->service);
1.23 markus 913: buffer_put_cstring(&b, authctxt->method->name);
914: buffer_put_char(&b, have_sig);
1.30 markus 915: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 916: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 917: buffer_put_string(&b, blob, bloblen);
918: }
919: xfree(blob);
1.51 markus 920:
1.1 markus 921: /* append signature */
922: buffer_put_string(&b, signature, slen);
923: xfree(signature);
924:
925: /* skip session id and packet type */
1.14 markus 926: if (buffer_len(&b) < skip + 1)
1.20 markus 927: fatal("userauth_pubkey: internal error");
1.14 markus 928: buffer_consume(&b, skip + 1);
1.1 markus 929:
930: /* put remaining data from buffer into packet */
931: packet_start(SSH2_MSG_USERAUTH_REQUEST);
932: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
933: buffer_free(&b);
934: packet_send();
1.17 markus 935:
936: return 1;
1.16 markus 937: }
938:
1.76 itojun 939: static int
1.117 markus 940: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 941: {
1.51 markus 942: u_char *blob;
1.97 markus 943: u_int bloblen, have_sig = 0;
1.20 markus 944:
1.51 markus 945: debug3("send_pubkey_test");
1.16 markus 946:
1.117 markus 947: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 948: /* we cannot handle this key */
949: debug3("send_pubkey_test: cannot handle key");
1.16 markus 950: return 0;
951: }
1.51 markus 952: /* register callback for USERAUTH_PK_OK message */
953: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
954:
955: packet_start(SSH2_MSG_USERAUTH_REQUEST);
956: packet_put_cstring(authctxt->server_user);
957: packet_put_cstring(authctxt->service);
958: packet_put_cstring(authctxt->method->name);
959: packet_put_char(have_sig);
960: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 961: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 962: packet_put_string(blob, bloblen);
963: xfree(blob);
964: packet_send();
965: return 1;
966: }
967:
1.76 itojun 968: static Key *
1.51 markus 969: load_identity_file(char *filename)
970: {
971: Key *private;
972: char prompt[300], *passphrase;
1.152 dtucker 973: int perm_ok, quit, i;
1.52 markus 974: struct stat st;
1.16 markus 975:
1.52 markus 976: if (stat(filename, &st) < 0) {
977: debug3("no such identity: %s", filename);
978: return NULL;
979: }
1.152 dtucker 980: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
981: if (!perm_ok)
982: return NULL;
1.56 markus 983: if (private == NULL) {
984: if (options.batch_mode)
1.51 markus 985: return NULL;
1.16 markus 986: snprintf(prompt, sizeof prompt,
1.88 deraadt 987: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 988: for (i = 0; i < options.number_of_password_prompts; i++) {
989: passphrase = read_passphrase(prompt, 0);
990: if (strcmp(passphrase, "") != 0) {
1.152 dtucker 991: private = key_load_private_type(KEY_UNSPEC,
992: filename, passphrase, NULL, NULL);
1.51 markus 993: quit = 0;
1.20 markus 994: } else {
995: debug2("no passphrase given, try next key");
1.51 markus 996: quit = 1;
1.20 markus 997: }
998: memset(passphrase, 0, strlen(passphrase));
999: xfree(passphrase);
1.56 markus 1000: if (private != NULL || quit)
1.20 markus 1001: break;
1002: debug2("bad passphrase given, try again...");
1.16 markus 1003: }
1004: }
1.51 markus 1005: return private;
1006: }
1007:
1.117 markus 1008: /*
1009: * try keys in the following order:
1010: * 1. agent keys that are found in the config file
1011: * 2. other agent keys
1012: * 3. keys that are only listed in the config file
1013: */
1014: static void
1015: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1016: {
1.117 markus 1017: Identity *id;
1018: Idlist agent, files, *preferred;
1019: Key *key;
1020: AuthenticationConnection *ac;
1021: char *comment;
1022: int i, found;
1.51 markus 1023:
1.117 markus 1024: TAILQ_INIT(&agent); /* keys from the agent */
1025: TAILQ_INIT(&files); /* keys from the config file */
1026: preferred = &authctxt->keys;
1027: TAILQ_INIT(preferred); /* preferred order of keys */
1028:
1029: /* list of keys stored in the filesystem */
1030: for (i = 0; i < options.num_identity_files; i++) {
1031: key = options.identity_keys[i];
1032: if (key && key->type == KEY_RSA1)
1033: continue;
1034: options.identity_keys[i] = NULL;
1.150 djm 1035: id = xcalloc(1, sizeof(*id));
1.117 markus 1036: id->key = key;
1037: id->filename = xstrdup(options.identity_files[i]);
1038: TAILQ_INSERT_TAIL(&files, id, next);
1039: }
1040: /* list of keys supported by the agent */
1041: if ((ac = ssh_get_authentication_connection())) {
1042: for (key = ssh_get_first_identity(ac, &comment, 2);
1043: key != NULL;
1044: key = ssh_get_next_identity(ac, &comment, 2)) {
1045: found = 0;
1046: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1047: /* agent keys from the config file are preferred */
1.117 markus 1048: if (key_equal(key, id->key)) {
1049: key_free(key);
1050: xfree(comment);
1051: TAILQ_REMOVE(&files, id, next);
1052: TAILQ_INSERT_TAIL(preferred, id, next);
1053: id->ac = ac;
1054: found = 1;
1055: break;
1056: }
1057: }
1.135 markus 1058: if (!found && !options.identities_only) {
1.150 djm 1059: id = xcalloc(1, sizeof(*id));
1.117 markus 1060: id->key = key;
1061: id->filename = comment;
1062: id->ac = ac;
1063: TAILQ_INSERT_TAIL(&agent, id, next);
1064: }
1065: }
1066: /* append remaining agent keys */
1067: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1068: TAILQ_REMOVE(&agent, id, next);
1069: TAILQ_INSERT_TAIL(preferred, id, next);
1070: }
1071: authctxt->agent = ac;
1072: }
1073: /* append remaining keys from the config file */
1074: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1075: TAILQ_REMOVE(&files, id, next);
1076: TAILQ_INSERT_TAIL(preferred, id, next);
1077: }
1078: TAILQ_FOREACH(id, preferred, next) {
1079: debug2("key: %s (%p)", id->filename, id->key);
1080: }
1.17 markus 1081: }
1082:
1.117 markus 1083: static void
1084: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1085: {
1.117 markus 1086: Identity *id;
1.51 markus 1087:
1.117 markus 1088: if (authctxt->agent != NULL)
1089: ssh_close_authentication_connection(authctxt->agent);
1090: for (id = TAILQ_FIRST(&authctxt->keys); id;
1091: id = TAILQ_FIRST(&authctxt->keys)) {
1092: TAILQ_REMOVE(&authctxt->keys, id, next);
1093: if (id->key)
1094: key_free(id->key);
1095: if (id->filename)
1096: xfree(id->filename);
1097: xfree(id);
1098: }
1.1 markus 1099: }
1100:
1.20 markus 1101: int
1102: userauth_pubkey(Authctxt *authctxt)
1103: {
1.117 markus 1104: Identity *id;
1.20 markus 1105: int sent = 0;
1106:
1.117 markus 1107: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1108: if (id->tried++)
1109: return (0);
1.127 markus 1110: /* move key to the end of the queue */
1.117 markus 1111: TAILQ_REMOVE(&authctxt->keys, id, next);
1112: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1113: /*
1114: * send a test message if we have the public key. for
1115: * encrypted keys we cannot do this and have to load the
1116: * private key instead
1117: */
1118: if (id->key && id->key->type != KEY_RSA1) {
1119: debug("Offering public key: %s", id->filename);
1120: sent = send_pubkey_test(authctxt, id);
1121: } else if (id->key == NULL) {
1122: debug("Trying private key: %s", id->filename);
1123: id->key = load_identity_file(id->filename);
1124: if (id->key != NULL) {
1125: id->isprivate = 1;
1126: sent = sign_and_send_pubkey(authctxt, id);
1127: key_free(id->key);
1128: id->key = NULL;
1.51 markus 1129: }
1130: }
1.117 markus 1131: if (sent)
1132: return (sent);
1.28 markus 1133: }
1.117 markus 1134: return (0);
1.20 markus 1135: }
1136:
1.23 markus 1137: /*
1138: * Send userauth request message specifying keyboard-interactive method.
1139: */
1140: int
1141: userauth_kbdint(Authctxt *authctxt)
1142: {
1143: static int attempt = 0;
1144:
1145: if (attempt++ >= options.number_of_password_prompts)
1146: return 0;
1.82 markus 1147: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1148: if (attempt > 1 && !authctxt->info_req_seen) {
1149: debug3("userauth_kbdint: disable: no info_req_seen");
1150: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1151: return 0;
1152: }
1.23 markus 1153:
1154: debug2("userauth_kbdint");
1155: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1156: packet_put_cstring(authctxt->server_user);
1157: packet_put_cstring(authctxt->service);
1158: packet_put_cstring(authctxt->method->name);
1159: packet_put_cstring(""); /* lang */
1160: packet_put_cstring(options.kbd_interactive_devices ?
1161: options.kbd_interactive_devices : "");
1162: packet_send();
1163:
1164: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1165: return 1;
1166: }
1167:
1168: /*
1.46 markus 1169: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1170: */
1171: void
1.92 markus 1172: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1173: {
1174: Authctxt *authctxt = ctxt;
1.46 markus 1175: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1176: u_int num_prompts, i;
1.23 markus 1177: int echo = 0;
1178:
1179: debug2("input_userauth_info_req");
1180:
1181: if (authctxt == NULL)
1182: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1183:
1184: authctxt->info_req_seen = 1;
1.23 markus 1185:
1186: name = packet_get_string(NULL);
1187: inst = packet_get_string(NULL);
1188: lang = packet_get_string(NULL);
1189: if (strlen(name) > 0)
1.116 itojun 1190: logit("%s", name);
1.23 markus 1191: if (strlen(inst) > 0)
1.116 itojun 1192: logit("%s", inst);
1.46 markus 1193: xfree(name);
1.23 markus 1194: xfree(inst);
1.46 markus 1195: xfree(lang);
1.23 markus 1196:
1197: num_prompts = packet_get_int();
1198: /*
1199: * Begin to build info response packet based on prompts requested.
1200: * We commit to providing the correct number of responses, so if
1201: * further on we run into a problem that prevents this, we have to
1202: * be sure and clean this up and send a correct error response.
1203: */
1204: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1205: packet_put_int(num_prompts);
1206:
1.73 markus 1207: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1208: for (i = 0; i < num_prompts; i++) {
1209: prompt = packet_get_string(NULL);
1210: echo = packet_get_char();
1211:
1.77 markus 1212: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1213:
1.49 markus 1214: packet_put_cstring(response);
1.23 markus 1215: memset(response, 0, strlen(response));
1216: xfree(response);
1217: xfree(prompt);
1218: }
1.90 markus 1219: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1220:
1.85 markus 1221: packet_add_padding(64);
1.23 markus 1222: packet_send();
1.68 markus 1223: }
1224:
1.100 markus 1225: static int
1.105 deraadt 1226: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1227: u_char *data, u_int datalen)
1228: {
1229: Buffer b;
1.101 markus 1230: struct stat st;
1.100 markus 1231: pid_t pid;
1.103 markus 1232: int to[2], from[2], status, version = 2;
1.100 markus 1233:
1.109 markus 1234: debug2("ssh_keysign called");
1.100 markus 1235:
1.101 markus 1236: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1237: error("ssh_keysign: no installed: %s", strerror(errno));
1238: return -1;
1239: }
1.100 markus 1240: if (fflush(stdout) != 0)
1241: error("ssh_keysign: fflush: %s", strerror(errno));
1242: if (pipe(to) < 0) {
1243: error("ssh_keysign: pipe: %s", strerror(errno));
1244: return -1;
1245: }
1246: if (pipe(from) < 0) {
1247: error("ssh_keysign: pipe: %s", strerror(errno));
1248: return -1;
1249: }
1250: if ((pid = fork()) < 0) {
1251: error("ssh_keysign: fork: %s", strerror(errno));
1252: return -1;
1253: }
1254: if (pid == 0) {
1.155 markus 1255: permanently_drop_suid(getuid());
1.100 markus 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;
1.163 djm 1307: char *chost, *pkalg, *p, myname[NI_MAXHOST];
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 */
1.163 djm 1331: p = NULL;
1332: if (packet_connection_is_on_socket())
1333: p = get_local_name(packet_get_connection_in());
1334: if (p == NULL) {
1335: if (gethostname(myname, sizeof(myname)) == -1) {
1336: verbose("userauth_hostbased: gethostname: %s",
1337: strerror(errno));
1338: } else
1339: p = xstrdup(myname);
1340: }
1.84 markus 1341: if (p == NULL) {
1342: error("userauth_hostbased: cannot get local ipaddr/name");
1343: key_free(private);
1.148 djm 1344: xfree(blob);
1.84 markus 1345: return 0;
1346: }
1347: len = strlen(p) + 2;
1.150 djm 1348: xasprintf(&chost, "%s.", p);
1.84 markus 1349: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1350: xfree(p);
1.84 markus 1351:
1.72 markus 1352: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1353: authctxt->service;
1.68 markus 1354: pkalg = xstrdup(key_ssh_name(private));
1355: buffer_init(&b);
1356: /* construct data */
1.72 markus 1357: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1358: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1359: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1360: buffer_put_cstring(&b, service);
1.68 markus 1361: buffer_put_cstring(&b, authctxt->method->name);
1362: buffer_put_cstring(&b, pkalg);
1363: buffer_put_string(&b, blob, blen);
1364: buffer_put_cstring(&b, chost);
1365: buffer_put_cstring(&b, authctxt->local_user);
1366: #ifdef DEBUG_PK
1367: buffer_dump(&b);
1368: #endif
1.100 markus 1369: if (sensitive->external_keysign)
1370: ok = ssh_keysign(private, &signature, &slen,
1371: buffer_ptr(&b), buffer_len(&b));
1372: else
1373: ok = key_sign(private, &signature, &slen,
1374: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1375: key_free(private);
1376: buffer_free(&b);
1377: if (ok != 0) {
1378: error("key_sign failed");
1379: xfree(chost);
1380: xfree(pkalg);
1.148 djm 1381: xfree(blob);
1.68 markus 1382: return 0;
1383: }
1384: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1385: packet_put_cstring(authctxt->server_user);
1386: packet_put_cstring(authctxt->service);
1387: packet_put_cstring(authctxt->method->name);
1388: packet_put_cstring(pkalg);
1389: packet_put_string(blob, blen);
1390: packet_put_cstring(chost);
1391: packet_put_cstring(authctxt->local_user);
1392: packet_put_string(signature, slen);
1393: memset(signature, 's', slen);
1394: xfree(signature);
1395: xfree(chost);
1396: xfree(pkalg);
1.148 djm 1397: xfree(blob);
1.68 markus 1398:
1399: packet_send();
1400: return 1;
1.23 markus 1401: }
1.20 markus 1402:
1403: /* find auth method */
1404:
1405: /*
1406: * given auth method name, if configurable options permit this method fill
1407: * in auth_ident field and return true, otherwise return false.
1408: */
1.76 itojun 1409: static int
1.20 markus 1410: authmethod_is_enabled(Authmethod *method)
1411: {
1412: if (method == NULL)
1413: return 0;
1414: /* return false if options indicate this method is disabled */
1415: if (method->enabled == NULL || *method->enabled == 0)
1416: return 0;
1417: /* return false if batch mode is enabled but method needs interactive mode */
1418: if (method->batch_flag != NULL && *method->batch_flag != 0)
1419: return 0;
1420: return 1;
1421: }
1422:
1.76 itojun 1423: static Authmethod *
1.20 markus 1424: authmethod_lookup(const char *name)
1.1 markus 1425: {
1.20 markus 1426: Authmethod *method = NULL;
1427: if (name != NULL)
1428: for (method = authmethods; method->name != NULL; method++)
1429: if (strcmp(name, method->name) == 0)
1430: return method;
1431: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1432: return NULL;
1433: }
1.1 markus 1434:
1.53 markus 1435: /* XXX internal state */
1436: static Authmethod *current = NULL;
1437: static char *supported = NULL;
1438: static char *preferred = NULL;
1.105 deraadt 1439:
1.20 markus 1440: /*
1441: * Given the authentication method list sent by the server, return the
1442: * next method we should try. If the server initially sends a nil list,
1.67 markus 1443: * use a built-in default list.
1.41 stevesk 1444: */
1.76 itojun 1445: static Authmethod *
1.20 markus 1446: authmethod_get(char *authlist)
1447: {
1.53 markus 1448: char *name = NULL;
1.97 markus 1449: u_int next;
1.41 stevesk 1450:
1.20 markus 1451: /* Use a suitable default if we're passed a nil list. */
1452: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1453: authlist = options.preferred_authentications;
1.20 markus 1454:
1.53 markus 1455: if (supported == NULL || strcmp(authlist, supported) != 0) {
1456: debug3("start over, passed a different list %s", authlist);
1457: if (supported != NULL)
1458: xfree(supported);
1459: supported = xstrdup(authlist);
1460: preferred = options.preferred_authentications;
1461: debug3("preferred %s", preferred);
1462: current = NULL;
1463: } else if (current != NULL && authmethod_is_enabled(current))
1464: return current;
1.20 markus 1465:
1.53 markus 1466: for (;;) {
1467: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1468: debug("No more authentication methods to try.");
1.53 markus 1469: current = NULL;
1470: return NULL;
1471: }
1472: preferred += next;
1.23 markus 1473: debug3("authmethod_lookup %s", name);
1.53 markus 1474: debug3("remaining preferred: %s", preferred);
1475: if ((current = authmethod_lookup(name)) != NULL &&
1476: authmethod_is_enabled(current)) {
1.23 markus 1477: debug3("authmethod_is_enabled %s", name);
1.109 markus 1478: debug("Next authentication method: %s", name);
1.53 markus 1479: return current;
1.23 markus 1480: }
1.1 markus 1481: }
1.53 markus 1482: }
1.1 markus 1483:
1.79 stevesk 1484: static char *
1.53 markus 1485: authmethods_get(void)
1486: {
1487: Authmethod *method = NULL;
1.93 markus 1488: Buffer b;
1489: char *list;
1.27 provos 1490:
1.93 markus 1491: buffer_init(&b);
1.53 markus 1492: for (method = authmethods; method->name != NULL; method++) {
1493: if (authmethod_is_enabled(method)) {
1.93 markus 1494: if (buffer_len(&b) > 0)
1495: buffer_append(&b, ",", 1);
1496: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1497: }
1498: }
1.93 markus 1499: buffer_append(&b, "\0", 1);
1500: list = xstrdup(buffer_ptr(&b));
1501: buffer_free(&b);
1502: return list;
1.1 markus 1503: }
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