Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.122
1.1 markus 1: /*
2: * Copyright (c) 2000 Markus Friedl. All rights reserved.
3: *
4: * Redistribution and use in source and binary forms, with or without
5: * modification, are permitted provided that the following conditions
6: * are met:
7: * 1. Redistributions of source code must retain the above copyright
8: * notice, this list of conditions and the following disclaimer.
9: * 2. Redistributions in binary form must reproduce the above copyright
10: * notice, this list of conditions and the following disclaimer in the
11: * documentation and/or other materials provided with the distribution.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: */
24:
25: #include "includes.h"
1.122 ! markus 26: RCSID("$OpenBSD: sshconnect2.c,v 1.121 2003/08/22 10:56:09 markus Exp $");
1.1 markus 27:
28: #include "ssh.h"
1.37 markus 29: #include "ssh2.h"
1.1 markus 30: #include "xmalloc.h"
31: #include "buffer.h"
32: #include "packet.h"
33: #include "compat.h"
34: #include "bufaux.h"
1.37 markus 35: #include "cipher.h"
1.1 markus 36: #include "kex.h"
37: #include "myproposal.h"
38: #include "sshconnect.h"
39: #include "authfile.h"
1.57 provos 40: #include "dh.h"
1.17 markus 41: #include "authfd.h"
1.37 markus 42: #include "log.h"
43: #include "readconf.h"
44: #include "readpass.h"
1.53 markus 45: #include "match.h"
1.61 markus 46: #include "dispatch.h"
1.68 markus 47: #include "canohost.h"
1.100 markus 48: #include "msg.h"
49: #include "pathnames.h"
1.22 provos 50:
1.121 markus 51: #ifdef GSSAPI
52: #include "ssh-gss.h"
53: #endif
54:
1.1 markus 55: /* import */
56: extern char *client_version_string;
57: extern char *server_version_string;
58: extern Options options;
59:
60: /*
61: * SSH2 key exchange
62: */
63:
1.32 markus 64: u_char *session_id2 = NULL;
1.120 markus 65: u_int session_id2_len = 0;
1.1 markus 66:
1.61 markus 67: char *xxx_host;
68: struct sockaddr *xxx_hostaddr;
69:
1.63 markus 70: Kex *xxx_kex = NULL;
71:
1.76 itojun 72: static int
1.75 markus 73: verify_host_key_callback(Key *hostkey)
1.61 markus 74: {
1.75 markus 75: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 76: fatal("Host key verification failed.");
1.61 markus 77: return 0;
78: }
79:
1.1 markus 80: void
1.22 provos 81: ssh_kex2(char *host, struct sockaddr *hostaddr)
82: {
83: Kex *kex;
1.61 markus 84:
85: xxx_host = host;
86: xxx_hostaddr = hostaddr;
1.22 provos 87:
1.29 markus 88: if (options.ciphers == (char *)-1) {
1.116 itojun 89: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 90: options.ciphers = NULL;
1.24 markus 91: }
1.22 provos 92: if (options.ciphers != NULL) {
93: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
94: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
95: }
1.60 stevesk 96: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
97: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
98: myproposal[PROPOSAL_ENC_ALGS_STOC] =
99: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 100: if (options.compression) {
1.47 markus 101: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.107 markus 102: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none";
1.22 provos 103: } else {
1.47 markus 104: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.107 markus 105: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib";
1.47 markus 106: }
107: if (options.macs != NULL) {
108: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
109: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 110: }
1.70 markus 111: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 112: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 113: options.hostkeyalgorithms;
1.115 markus 114:
115: if (options.rekey_limit)
116: packet_set_rekey_limit(options.rekey_limit);
1.22 provos 117:
1.65 markus 118: /* start key exchange */
1.64 markus 119: kex = kex_setup(myproposal);
1.111 markus 120: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
121: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.61 markus 122: kex->client_version_string=client_version_string;
123: kex->server_version_string=server_version_string;
1.75 markus 124: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 125:
126: xxx_kex = kex;
1.22 provos 127:
1.66 markus 128: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 129:
130: session_id2 = kex->session_id;
131: session_id2_len = kex->session_id_len;
1.22 provos 132:
133: #ifdef DEBUG_KEXDH
134: /* send 1st encrypted/maced/compressed message */
135: packet_start(SSH2_MSG_IGNORE);
136: packet_put_cstring("markus");
137: packet_send();
138: packet_write_wait();
139: #endif
1.1 markus 140: }
1.11 markus 141:
1.1 markus 142: /*
143: * Authenticate user
144: */
1.20 markus 145:
146: typedef struct Authctxt Authctxt;
147: typedef struct Authmethod Authmethod;
1.117 markus 148: typedef struct identity Identity;
149: typedef struct idlist Idlist;
1.20 markus 150:
1.117 markus 151: struct identity {
152: TAILQ_ENTRY(identity) next;
153: AuthenticationConnection *ac; /* set if agent supports key */
154: Key *key; /* public/private key */
155: char *filename; /* comment for agent-only keys */
156: int tried;
157: int isprivate; /* key points to the private key */
158: };
159: TAILQ_HEAD(idlist, identity);
1.20 markus 160:
161: struct Authctxt {
162: const char *server_user;
1.68 markus 163: const char *local_user;
1.20 markus 164: const char *host;
165: const char *service;
1.23 markus 166: Authmethod *method;
1.20 markus 167: int success;
1.51 markus 168: char *authlist;
1.68 markus 169: /* pubkey */
1.117 markus 170: Idlist keys;
1.68 markus 171: AuthenticationConnection *agent;
172: /* hostbased */
1.100 markus 173: Sensitive *sensitive;
1.82 markus 174: /* kbd-interactive */
175: int info_req_seen;
1.121 markus 176: /* generic */
177: void *methoddata;
1.20 markus 178: };
179: struct Authmethod {
180: char *name; /* string to compare against server's list */
181: int (*userauth)(Authctxt *authctxt);
182: int *enabled; /* flag in option struct that enables method */
183: int *batch_flag; /* flag in option struct that disables method */
184: };
185:
1.92 markus 186: void input_userauth_success(int, u_int32_t, void *);
187: void input_userauth_failure(int, u_int32_t, void *);
188: void input_userauth_banner(int, u_int32_t, void *);
189: void input_userauth_error(int, u_int32_t, void *);
190: void input_userauth_info_req(int, u_int32_t, void *);
191: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 192: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 193:
194: int userauth_none(Authctxt *);
195: int userauth_pubkey(Authctxt *);
196: int userauth_passwd(Authctxt *);
197: int userauth_kbdint(Authctxt *);
198: int userauth_hostbased(Authctxt *);
1.118 markus 199: int userauth_kerberos(Authctxt *);
1.20 markus 200:
1.121 markus 201: #ifdef GSSAPI
202: int userauth_gssapi(Authctxt *authctxt);
203: void input_gssapi_response(int type, u_int32_t, void *);
204: void input_gssapi_token(int type, u_int32_t, void *);
205: void input_gssapi_hash(int type, u_int32_t, void *);
206: void input_gssapi_error(int, u_int32_t, void *);
207: void input_gssapi_errtok(int, u_int32_t, void *);
208: #endif
209:
1.86 itojun 210: void userauth(Authctxt *, char *);
1.51 markus 211:
1.117 markus 212: static int sign_and_send_pubkey(Authctxt *, Identity *);
213: static void pubkey_prepare(Authctxt *);
214: static void pubkey_cleanup(Authctxt *);
215: static Key *load_identity_file(char *);
1.76 itojun 216:
217: static Authmethod *authmethod_get(char *authlist);
218: static Authmethod *authmethod_lookup(const char *name);
219: static char *authmethods_get(void);
1.20 markus 220:
221: Authmethod authmethods[] = {
1.121 markus 222: #ifdef GSSAPI
223: {"gssapi",
224: userauth_gssapi,
225: &options.gss_authentication,
226: NULL},
227: #endif
1.81 markus 228: {"hostbased",
229: userauth_hostbased,
230: &options.hostbased_authentication,
231: NULL},
1.20 markus 232: {"publickey",
233: userauth_pubkey,
1.28 markus 234: &options.pubkey_authentication,
1.20 markus 235: NULL},
1.81 markus 236: {"keyboard-interactive",
237: userauth_kbdint,
238: &options.kbd_interactive_authentication,
239: &options.batch_mode},
1.20 markus 240: {"password",
241: userauth_passwd,
242: &options.password_authentication,
1.23 markus 243: &options.batch_mode},
244: {"none",
245: userauth_none,
246: NULL,
247: NULL},
1.20 markus 248: {NULL, NULL, NULL, NULL}
249: };
250:
251: void
1.68 markus 252: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 253: Sensitive *sensitive)
1.20 markus 254: {
255: Authctxt authctxt;
256: int type;
1.39 markus 257:
1.73 markus 258: if (options.challenge_response_authentication)
1.39 markus 259: options.kbd_interactive_authentication = 1;
1.20 markus 260:
261: packet_start(SSH2_MSG_SERVICE_REQUEST);
262: packet_put_cstring("ssh-userauth");
263: packet_send();
1.108 markus 264: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 265: packet_write_wait();
1.91 markus 266: type = packet_read();
1.108 markus 267: if (type != SSH2_MSG_SERVICE_ACCEPT)
268: fatal("Server denied authentication request: %d", type);
1.20 markus 269: if (packet_remaining() > 0) {
1.91 markus 270: char *reply = packet_get_string(NULL);
1.108 markus 271: debug2("service_accept: %s", reply);
1.20 markus 272: xfree(reply);
273: } else {
1.109 markus 274: debug2("buggy server: service_accept w/o service");
1.20 markus 275: }
1.90 markus 276: packet_check_eom();
1.108 markus 277: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 278:
1.53 markus 279: if (options.preferred_authentications == NULL)
280: options.preferred_authentications = authmethods_get();
281:
1.20 markus 282: /* setup authentication context */
1.82 markus 283: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 284: pubkey_prepare(&authctxt);
1.20 markus 285: authctxt.server_user = server_user;
1.68 markus 286: authctxt.local_user = local_user;
1.20 markus 287: authctxt.host = host;
288: authctxt.service = "ssh-connection"; /* service name */
289: authctxt.success = 0;
1.23 markus 290: authctxt.method = authmethod_lookup("none");
1.51 markus 291: authctxt.authlist = NULL;
1.121 markus 292: authctxt.methoddata = NULL;
1.100 markus 293: authctxt.sensitive = sensitive;
1.82 markus 294: authctxt.info_req_seen = 0;
1.23 markus 295: if (authctxt.method == NULL)
296: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 297:
298: /* initial userauth request */
1.23 markus 299: userauth_none(&authctxt);
1.20 markus 300:
1.65 markus 301: dispatch_init(&input_userauth_error);
1.20 markus 302: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
303: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 304: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 305: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
306:
1.117 markus 307: pubkey_cleanup(&authctxt);
1.119 markus 308: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
309:
1.109 markus 310: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 311: }
1.119 markus 312:
1.20 markus 313: void
1.51 markus 314: userauth(Authctxt *authctxt, char *authlist)
315: {
1.121 markus 316: if (authctxt->methoddata) {
317: xfree(authctxt->methoddata);
318: authctxt->methoddata = NULL;
319: }
1.51 markus 320: if (authlist == NULL) {
321: authlist = authctxt->authlist;
322: } else {
323: if (authctxt->authlist)
324: xfree(authctxt->authlist);
325: authctxt->authlist = authlist;
326: }
327: for (;;) {
328: Authmethod *method = authmethod_get(authlist);
329: if (method == NULL)
330: fatal("Permission denied (%s).", authlist);
331: authctxt->method = method;
1.119 markus 332:
333: /* reset the per method handler */
334: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
335: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
336:
337: /* and try new method */
1.51 markus 338: if (method->userauth(authctxt) != 0) {
339: debug2("we sent a %s packet, wait for reply", method->name);
340: break;
341: } else {
342: debug2("we did not send a packet, disable method");
343: method->enabled = NULL;
344: }
345: }
346: }
1.105 deraadt 347:
1.51 markus 348: void
1.92 markus 349: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 350: {
1.35 markus 351: fatal("input_userauth_error: bad message during authentication: "
352: "type %d", type);
353: }
1.105 deraadt 354:
1.35 markus 355: void
1.92 markus 356: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 357: {
358: char *msg, *lang;
359: debug3("input_userauth_banner");
360: msg = packet_get_string(NULL);
361: lang = packet_get_string(NULL);
362: fprintf(stderr, "%s", msg);
363: xfree(msg);
364: xfree(lang);
1.20 markus 365: }
1.105 deraadt 366:
1.20 markus 367: void
1.92 markus 368: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 369: {
370: Authctxt *authctxt = ctxt;
371: if (authctxt == NULL)
372: fatal("input_userauth_success: no authentication context");
1.51 markus 373: if (authctxt->authlist)
374: xfree(authctxt->authlist);
1.121 markus 375: if (authctxt->methoddata)
376: xfree(authctxt->methoddata);
1.20 markus 377: authctxt->success = 1; /* break out */
378: }
1.105 deraadt 379:
1.20 markus 380: void
1.92 markus 381: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 382: {
383: Authctxt *authctxt = ctxt;
384: char *authlist = NULL;
385: int partial;
386:
387: if (authctxt == NULL)
388: fatal("input_userauth_failure: no authentication context");
389:
1.23 markus 390: authlist = packet_get_string(NULL);
1.20 markus 391: partial = packet_get_char();
1.90 markus 392: packet_check_eom();
1.20 markus 393:
394: if (partial != 0)
1.116 itojun 395: logit("Authenticated with partial success.");
1.109 markus 396: debug("Authentications that can continue: %s", authlist);
1.20 markus 397:
1.51 markus 398: userauth(authctxt, authlist);
399: }
400: void
1.92 markus 401: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 402: {
403: Authctxt *authctxt = ctxt;
404: Key *key = NULL;
1.117 markus 405: Identity *id = NULL;
1.51 markus 406: Buffer b;
1.96 markus 407: int pktype, sent = 0;
408: u_int alen, blen;
409: char *pkalg, *fp;
410: u_char *pkblob;
1.51 markus 411:
412: if (authctxt == NULL)
413: fatal("input_userauth_pk_ok: no authentication context");
414: if (datafellows & SSH_BUG_PKOK) {
415: /* this is similar to SSH_BUG_PKAUTH */
416: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
417: pkblob = packet_get_string(&blen);
418: buffer_init(&b);
419: buffer_append(&b, pkblob, blen);
420: pkalg = buffer_get_string(&b, &alen);
421: buffer_free(&b);
422: } else {
423: pkalg = packet_get_string(&alen);
424: pkblob = packet_get_string(&blen);
425: }
1.90 markus 426: packet_check_eom();
1.51 markus 427:
1.117 markus 428: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 429:
1.117 markus 430: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
431: debug("unknown pkalg %s", pkalg);
432: goto done;
433: }
434: if ((key = key_from_blob(pkblob, blen)) == NULL) {
435: debug("no key from blob. pkalg %s", pkalg);
436: goto done;
437: }
438: if (key->type != pktype) {
439: error("input_userauth_pk_ok: type mismatch "
440: "for decoded key (received %d, expected %d)",
441: key->type, pktype);
442: goto done;
443: }
444: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
445: debug2("input_userauth_pk_ok: fp %s", fp);
446: xfree(fp);
447:
448: TAILQ_FOREACH(id, &authctxt->keys, next) {
449: if (key_equal(key, id->key)) {
450: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 451: break;
452: }
1.117 markus 453: }
454: done:
1.51 markus 455: if (key != NULL)
456: key_free(key);
457: xfree(pkalg);
458: xfree(pkblob);
459:
1.106 deraadt 460: /* try another method if we did not send a packet */
1.51 markus 461: if (sent == 0)
462: userauth(authctxt, NULL);
1.20 markus 463: }
1.121 markus 464:
465: #ifdef GSSAPI
466: int
467: userauth_gssapi(Authctxt *authctxt)
468: {
469: Gssctxt *gssctxt = NULL;
470: static gss_OID_set supported = NULL;
471: static int mech = 0;
472: OM_uint32 min;
473: int ok = 0;
474:
475: /* Try one GSSAPI method at a time, rather than sending them all at
476: * once. */
477:
478: if (supported == NULL)
479: gss_indicate_mechs(&min, &supported);
480:
481: /* Check to see if the mechanism is usable before we offer it */
482: while (mech<supported->count && !ok) {
483: if (gssctxt)
484: ssh_gssapi_delete_ctx(&gssctxt);
485: ssh_gssapi_build_ctx(&gssctxt);
486: ssh_gssapi_set_oid(gssctxt, &supported->elements[mech]);
487:
488: /* My DER encoding requires length<128 */
489: if (supported->elements[mech].length < 128 &&
490: !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
491: authctxt->host))) {
492: ok = 1; /* Mechanism works */
493: } else {
494: mech++;
495: }
496: }
497:
498: if (!ok) return 0;
499:
500: authctxt->methoddata=(void *)gssctxt;
501:
502: packet_start(SSH2_MSG_USERAUTH_REQUEST);
503: packet_put_cstring(authctxt->server_user);
504: packet_put_cstring(authctxt->service);
505: packet_put_cstring(authctxt->method->name);
506:
507: packet_put_int(1);
508:
509: /* Some servers encode the OID incorrectly (as we used to) */
510: if (datafellows & SSH_BUG_GSSAPI_BER) {
511: packet_put_string(supported->elements[mech].elements,
512: supported->elements[mech].length);
513: } else {
514: packet_put_int((supported->elements[mech].length)+2);
515: packet_put_char(SSH_GSS_OIDTYPE);
516: packet_put_char(supported->elements[mech].length);
517: packet_put_raw(supported->elements[mech].elements,
518: supported->elements[mech].length);
519: }
520:
521: packet_send();
522:
523: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
524: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
525: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
526: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
527:
528: mech++; /* Move along to next candidate */
529:
530: return 1;
531: }
532:
533: void
534: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
535: {
536: Authctxt *authctxt = ctxt;
537: Gssctxt *gssctxt;
538: OM_uint32 status, ms;
539: int oidlen;
540: char *oidv;
541: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
542:
543: if (authctxt == NULL)
544: fatal("input_gssapi_response: no authentication context");
545: gssctxt = authctxt->methoddata;
546:
547: /* Setup our OID */
548: oidv = packet_get_string(&oidlen);
549:
550: if (datafellows & SSH_BUG_GSSAPI_BER) {
551: if (!ssh_gssapi_check_oid(gssctxt, oidv, oidlen))
552: fatal("Server returned different OID than expected");
553: } else {
554: if(oidv[0] != SSH_GSS_OIDTYPE || oidv[1] != oidlen-2) {
555: debug("Badly encoded mechanism OID received");
556: userauth(authctxt, NULL);
557: xfree(oidv);
558: return;
559: }
560: if (!ssh_gssapi_check_oid(gssctxt, oidv+2, oidlen-2))
561: fatal("Server returned different OID than expected");
562: }
563:
564: packet_check_eom();
565:
566: xfree(oidv);
567:
568: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
569: GSS_C_NO_BUFFER, &send_tok, NULL);
570: if (GSS_ERROR(status)) {
571: if (send_tok.length > 0) {
572: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
573: packet_put_string(send_tok.value, send_tok.length);
574: packet_send();
575: gss_release_buffer(&ms, &send_tok);
576: }
577: /* Start again with next method on list */
578: debug("Trying to start again");
579: userauth(authctxt, NULL);
580: return;
581: }
582:
583: /* We must have data to send */
584: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
585: packet_put_string(send_tok.value, send_tok.length);
586: packet_send();
587: gss_release_buffer(&ms, &send_tok);
588: }
589:
590: void
591: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
592: {
593: Authctxt *authctxt = ctxt;
594: Gssctxt *gssctxt;
595: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
596: gss_buffer_desc recv_tok;
597: OM_uint32 status, ms;
598: u_int slen;
599:
600: if (authctxt == NULL)
601: fatal("input_gssapi_response: no authentication context");
602: gssctxt = authctxt->methoddata;
603:
604: recv_tok.value = packet_get_string(&slen);
605: recv_tok.length = slen; /* safe typecast */
606:
607: packet_check_eom();
608:
609: status=ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
610: &recv_tok, &send_tok, NULL);
611:
612: xfree(recv_tok.value);
613:
614: if (GSS_ERROR(status)) {
615: if (send_tok.length > 0) {
616: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
617: packet_put_string(send_tok.value, send_tok.length);
618: packet_send();
619: gss_release_buffer(&ms, &send_tok);
620: }
621: /* Start again with the next method in the list */
622: userauth(authctxt, NULL);
623: return;
624: }
625:
626: if (send_tok.length > 0) {
627: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
628: packet_put_string(send_tok.value, send_tok.length);
629: packet_send();
630: gss_release_buffer(&ms, &send_tok);
631: }
632:
633: if (status == GSS_S_COMPLETE) {
634: /* If that succeeded, send a exchange complete message */
635: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
636: packet_send();
637: }
638: }
639:
640: void
641: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
642: {
643: Authctxt *authctxt = ctxt;
644: Gssctxt *gssctxt;
645: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
646: gss_buffer_desc recv_tok;
647: OM_uint32 status, ms;
648:
649: if (authctxt == NULL)
650: fatal("input_gssapi_response: no authentication context");
651: gssctxt = authctxt->methoddata;
652:
653: recv_tok.value = packet_get_string(&recv_tok.length);
654:
655: packet_check_eom();
656:
657: /* Stick it into GSSAPI and see what it says */
658: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
659: &recv_tok, &send_tok, NULL);
660:
661: xfree(recv_tok.value);
662: gss_release_buffer(&ms, &send_tok);
663:
664: /* Server will be returning a failed packet after this one */
665: }
666:
667: void
668: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
669: {
670: OM_uint32 maj, min;
671: char *msg;
672: char *lang;
673:
674: maj=packet_get_int();
675: min=packet_get_int();
676: msg=packet_get_string(NULL);
677: lang=packet_get_string(NULL);
678:
679: packet_check_eom();
680:
681: debug("Server GSSAPI Error:\n%s\n", msg);
682: xfree(msg);
683: xfree(lang);
684: }
685: #endif /* GSSAPI */
1.20 markus 686:
1.1 markus 687: int
1.23 markus 688: userauth_none(Authctxt *authctxt)
689: {
690: /* initial userauth request */
691: packet_start(SSH2_MSG_USERAUTH_REQUEST);
692: packet_put_cstring(authctxt->server_user);
693: packet_put_cstring(authctxt->service);
694: packet_put_cstring(authctxt->method->name);
695: packet_send();
696: return 1;
697: }
698:
699: int
1.20 markus 700: userauth_passwd(Authctxt *authctxt)
1.1 markus 701: {
1.6 markus 702: static int attempt = 0;
1.99 markus 703: char prompt[150];
1.1 markus 704: char *password;
1.6 markus 705:
1.13 todd 706: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 707: return 0;
1.13 todd 708:
1.87 deraadt 709: if (attempt != 1)
1.13 todd 710: error("Permission denied, please try again.");
1.1 markus 711:
1.43 itojun 712: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 713: authctxt->server_user, authctxt->host);
1.1 markus 714: password = read_passphrase(prompt, 0);
715: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 716: packet_put_cstring(authctxt->server_user);
717: packet_put_cstring(authctxt->service);
1.23 markus 718: packet_put_cstring(authctxt->method->name);
1.1 markus 719: packet_put_char(0);
1.49 markus 720: packet_put_cstring(password);
1.1 markus 721: memset(password, 0, strlen(password));
722: xfree(password);
1.85 markus 723: packet_add_padding(64);
1.1 markus 724: packet_send();
1.99 markus 725:
1.104 deraadt 726: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 727: &input_userauth_passwd_changereq);
728:
1.1 markus 729: return 1;
730: }
1.99 markus 731: /*
732: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
733: */
734: void
735: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
736: {
737: Authctxt *authctxt = ctxt;
738: char *info, *lang, *password = NULL, *retype = NULL;
739: char prompt[150];
740:
741: debug2("input_userauth_passwd_changereq");
742:
743: if (authctxt == NULL)
744: fatal("input_userauth_passwd_changereq: "
745: "no authentication context");
746:
747: info = packet_get_string(NULL);
748: lang = packet_get_string(NULL);
749: if (strlen(info) > 0)
1.116 itojun 750: logit("%s", info);
1.99 markus 751: xfree(info);
752: xfree(lang);
753: packet_start(SSH2_MSG_USERAUTH_REQUEST);
754: packet_put_cstring(authctxt->server_user);
755: packet_put_cstring(authctxt->service);
756: packet_put_cstring(authctxt->method->name);
757: packet_put_char(1); /* additional info */
1.104 deraadt 758: snprintf(prompt, sizeof(prompt),
1.99 markus 759: "Enter %.30s@%.128s's old password: ",
760: authctxt->server_user, authctxt->host);
761: password = read_passphrase(prompt, 0);
762: packet_put_cstring(password);
763: memset(password, 0, strlen(password));
764: xfree(password);
765: password = NULL;
766: while (password == NULL) {
1.104 deraadt 767: snprintf(prompt, sizeof(prompt),
1.99 markus 768: "Enter %.30s@%.128s's new password: ",
769: authctxt->server_user, authctxt->host);
770: password = read_passphrase(prompt, RP_ALLOW_EOF);
771: if (password == NULL) {
772: /* bail out */
773: return;
774: }
1.104 deraadt 775: snprintf(prompt, sizeof(prompt),
1.99 markus 776: "Retype %.30s@%.128s's new password: ",
777: authctxt->server_user, authctxt->host);
778: retype = read_passphrase(prompt, 0);
779: if (strcmp(password, retype) != 0) {
780: memset(password, 0, strlen(password));
781: xfree(password);
1.116 itojun 782: logit("Mismatch; try again, EOF to quit.");
1.99 markus 783: password = NULL;
784: }
785: memset(retype, 0, strlen(retype));
786: xfree(retype);
787: }
788: packet_put_cstring(password);
789: memset(password, 0, strlen(password));
790: xfree(password);
791: packet_add_padding(64);
792: packet_send();
1.104 deraadt 793:
794: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 795: &input_userauth_passwd_changereq);
1.117 markus 796: }
797:
798: static int
799: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
800: u_char *data, u_int datalen)
801: {
802: Key *prv;
803: int ret;
1.99 markus 804:
1.117 markus 805: /* the agent supports this key */
806: if (id->ac)
807: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
808: data, datalen));
809: /*
810: * we have already loaded the private key or
811: * the private key is stored in external hardware
812: */
813: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
814: return (key_sign(id->key, sigp, lenp, data, datalen));
815: /* load the private key from the file */
816: if ((prv = load_identity_file(id->filename)) == NULL)
817: return (-1);
818: ret = key_sign(prv, sigp, lenp, data, datalen);
819: key_free(prv);
820: return (ret);
1.51 markus 821: }
822:
1.76 itojun 823: static int
1.117 markus 824: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 825: {
826: Buffer b;
1.32 markus 827: u_char *blob, *signature;
1.96 markus 828: u_int bloblen, slen;
1.120 markus 829: u_int skip = 0;
1.17 markus 830: int ret = -1;
1.23 markus 831: int have_sig = 1;
1.1 markus 832:
1.30 markus 833: debug3("sign_and_send_pubkey");
1.51 markus 834:
1.117 markus 835: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 836: /* we cannot handle this key */
1.30 markus 837: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 838: return 0;
839: }
1.1 markus 840: /* data to be signed */
841: buffer_init(&b);
1.26 markus 842: if (datafellows & SSH_OLD_SESSIONID) {
843: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 844: skip = session_id2_len;
1.26 markus 845: } else {
1.14 markus 846: buffer_put_string(&b, session_id2, session_id2_len);
847: skip = buffer_len(&b);
848: }
1.1 markus 849: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 850: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 851: buffer_put_cstring(&b,
1.30 markus 852: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 853: "ssh-userauth" :
1.20 markus 854: authctxt->service);
1.30 markus 855: if (datafellows & SSH_BUG_PKAUTH) {
856: buffer_put_char(&b, have_sig);
857: } else {
858: buffer_put_cstring(&b, authctxt->method->name);
859: buffer_put_char(&b, have_sig);
1.117 markus 860: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 861: }
1.1 markus 862: buffer_put_string(&b, blob, bloblen);
863:
864: /* generate signature */
1.117 markus 865: ret = identity_sign(id, &signature, &slen,
1.51 markus 866: buffer_ptr(&b), buffer_len(&b));
1.17 markus 867: if (ret == -1) {
868: xfree(blob);
869: buffer_free(&b);
870: return 0;
871: }
1.28 markus 872: #ifdef DEBUG_PK
1.1 markus 873: buffer_dump(&b);
874: #endif
1.30 markus 875: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 876: buffer_clear(&b);
877: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 878: skip = session_id2_len;
1.10 markus 879: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 880: buffer_put_cstring(&b, authctxt->server_user);
881: buffer_put_cstring(&b, authctxt->service);
1.23 markus 882: buffer_put_cstring(&b, authctxt->method->name);
883: buffer_put_char(&b, have_sig);
1.30 markus 884: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 885: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 886: buffer_put_string(&b, blob, bloblen);
887: }
888: xfree(blob);
1.51 markus 889:
1.1 markus 890: /* append signature */
891: buffer_put_string(&b, signature, slen);
892: xfree(signature);
893:
894: /* skip session id and packet type */
1.14 markus 895: if (buffer_len(&b) < skip + 1)
1.20 markus 896: fatal("userauth_pubkey: internal error");
1.14 markus 897: buffer_consume(&b, skip + 1);
1.1 markus 898:
899: /* put remaining data from buffer into packet */
900: packet_start(SSH2_MSG_USERAUTH_REQUEST);
901: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
902: buffer_free(&b);
903: packet_send();
1.17 markus 904:
905: return 1;
1.16 markus 906: }
907:
1.76 itojun 908: static int
1.117 markus 909: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 910: {
1.51 markus 911: u_char *blob;
1.97 markus 912: u_int bloblen, have_sig = 0;
1.20 markus 913:
1.51 markus 914: debug3("send_pubkey_test");
1.16 markus 915:
1.117 markus 916: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 917: /* we cannot handle this key */
918: debug3("send_pubkey_test: cannot handle key");
1.16 markus 919: return 0;
920: }
1.51 markus 921: /* register callback for USERAUTH_PK_OK message */
922: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
923:
924: packet_start(SSH2_MSG_USERAUTH_REQUEST);
925: packet_put_cstring(authctxt->server_user);
926: packet_put_cstring(authctxt->service);
927: packet_put_cstring(authctxt->method->name);
928: packet_put_char(have_sig);
929: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 930: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 931: packet_put_string(blob, bloblen);
932: xfree(blob);
933: packet_send();
934: return 1;
935: }
936:
1.76 itojun 937: static Key *
1.51 markus 938: load_identity_file(char *filename)
939: {
940: Key *private;
941: char prompt[300], *passphrase;
1.56 markus 942: int quit, i;
1.52 markus 943: struct stat st;
1.16 markus 944:
1.52 markus 945: if (stat(filename, &st) < 0) {
946: debug3("no such identity: %s", filename);
947: return NULL;
948: }
1.56 markus 949: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
950: if (private == NULL) {
951: if (options.batch_mode)
1.51 markus 952: return NULL;
1.16 markus 953: snprintf(prompt, sizeof prompt,
1.88 deraadt 954: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 955: for (i = 0; i < options.number_of_password_prompts; i++) {
956: passphrase = read_passphrase(prompt, 0);
957: if (strcmp(passphrase, "") != 0) {
1.56 markus 958: private = key_load_private_type(KEY_UNSPEC, filename,
959: passphrase, NULL);
1.51 markus 960: quit = 0;
1.20 markus 961: } else {
962: debug2("no passphrase given, try next key");
1.51 markus 963: quit = 1;
1.20 markus 964: }
965: memset(passphrase, 0, strlen(passphrase));
966: xfree(passphrase);
1.56 markus 967: if (private != NULL || quit)
1.20 markus 968: break;
969: debug2("bad passphrase given, try again...");
1.16 markus 970: }
971: }
1.51 markus 972: return private;
973: }
974:
1.117 markus 975: /*
976: * try keys in the following order:
977: * 1. agent keys that are found in the config file
978: * 2. other agent keys
979: * 3. keys that are only listed in the config file
980: */
981: static void
982: pubkey_prepare(Authctxt *authctxt)
1.51 markus 983: {
1.117 markus 984: Identity *id;
985: Idlist agent, files, *preferred;
986: Key *key;
987: AuthenticationConnection *ac;
988: char *comment;
989: int i, found;
1.51 markus 990:
1.117 markus 991: TAILQ_INIT(&agent); /* keys from the agent */
992: TAILQ_INIT(&files); /* keys from the config file */
993: preferred = &authctxt->keys;
994: TAILQ_INIT(preferred); /* preferred order of keys */
995:
996: /* list of keys stored in the filesystem */
997: for (i = 0; i < options.num_identity_files; i++) {
998: key = options.identity_keys[i];
999: if (key && key->type == KEY_RSA1)
1000: continue;
1001: options.identity_keys[i] = NULL;
1002: id = xmalloc(sizeof(*id));
1003: memset(id, 0, sizeof(*id));
1004: id->key = key;
1005: id->filename = xstrdup(options.identity_files[i]);
1006: TAILQ_INSERT_TAIL(&files, id, next);
1007: }
1008: /* list of keys supported by the agent */
1009: if ((ac = ssh_get_authentication_connection())) {
1010: for (key = ssh_get_first_identity(ac, &comment, 2);
1011: key != NULL;
1012: key = ssh_get_next_identity(ac, &comment, 2)) {
1013: found = 0;
1014: TAILQ_FOREACH(id, &files, next) {
1015: /* agent keys from the config file are preferred */
1016: if (key_equal(key, id->key)) {
1017: key_free(key);
1018: xfree(comment);
1019: TAILQ_REMOVE(&files, id, next);
1020: TAILQ_INSERT_TAIL(preferred, id, next);
1021: id->ac = ac;
1022: found = 1;
1023: break;
1024: }
1025: }
1026: if (!found) {
1027: id = xmalloc(sizeof(*id));
1028: memset(id, 0, sizeof(*id));
1029: id->key = key;
1030: id->filename = comment;
1031: id->ac = ac;
1032: TAILQ_INSERT_TAIL(&agent, id, next);
1033: }
1034: }
1035: /* append remaining agent keys */
1036: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1037: TAILQ_REMOVE(&agent, id, next);
1038: TAILQ_INSERT_TAIL(preferred, id, next);
1039: }
1040: authctxt->agent = ac;
1041: }
1042: /* append remaining keys from the config file */
1043: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1044: TAILQ_REMOVE(&files, id, next);
1045: TAILQ_INSERT_TAIL(preferred, id, next);
1046: }
1047: TAILQ_FOREACH(id, preferred, next) {
1048: debug2("key: %s (%p)", id->filename, id->key);
1049: }
1.17 markus 1050: }
1051:
1.117 markus 1052: static void
1053: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1054: {
1.117 markus 1055: Identity *id;
1.51 markus 1056:
1.117 markus 1057: if (authctxt->agent != NULL)
1058: ssh_close_authentication_connection(authctxt->agent);
1059: for (id = TAILQ_FIRST(&authctxt->keys); id;
1060: id = TAILQ_FIRST(&authctxt->keys)) {
1061: TAILQ_REMOVE(&authctxt->keys, id, next);
1062: if (id->key)
1063: key_free(id->key);
1064: if (id->filename)
1065: xfree(id->filename);
1066: xfree(id);
1067: }
1.1 markus 1068: }
1069:
1.20 markus 1070: int
1071: userauth_pubkey(Authctxt *authctxt)
1072: {
1.117 markus 1073: Identity *id;
1.20 markus 1074: int sent = 0;
1075:
1.117 markus 1076: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1077: if (id->tried++)
1078: return (0);
1079: TAILQ_REMOVE(&authctxt->keys, id, next);
1080: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1081: /*
1082: * send a test message if we have the public key. for
1083: * encrypted keys we cannot do this and have to load the
1084: * private key instead
1085: */
1086: if (id->key && id->key->type != KEY_RSA1) {
1087: debug("Offering public key: %s", id->filename);
1088: sent = send_pubkey_test(authctxt, id);
1089: } else if (id->key == NULL) {
1090: debug("Trying private key: %s", id->filename);
1091: id->key = load_identity_file(id->filename);
1092: if (id->key != NULL) {
1093: id->isprivate = 1;
1094: sent = sign_and_send_pubkey(authctxt, id);
1095: key_free(id->key);
1096: id->key = NULL;
1.51 markus 1097: }
1098: }
1.117 markus 1099: if (sent)
1100: return (sent);
1.28 markus 1101: }
1.117 markus 1102: return (0);
1.20 markus 1103: }
1104:
1.23 markus 1105: /*
1106: * Send userauth request message specifying keyboard-interactive method.
1107: */
1108: int
1109: userauth_kbdint(Authctxt *authctxt)
1110: {
1111: static int attempt = 0;
1112:
1113: if (attempt++ >= options.number_of_password_prompts)
1114: return 0;
1.82 markus 1115: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1116: if (attempt > 1 && !authctxt->info_req_seen) {
1117: debug3("userauth_kbdint: disable: no info_req_seen");
1118: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1119: return 0;
1120: }
1.23 markus 1121:
1122: debug2("userauth_kbdint");
1123: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1124: packet_put_cstring(authctxt->server_user);
1125: packet_put_cstring(authctxt->service);
1126: packet_put_cstring(authctxt->method->name);
1127: packet_put_cstring(""); /* lang */
1128: packet_put_cstring(options.kbd_interactive_devices ?
1129: options.kbd_interactive_devices : "");
1130: packet_send();
1131:
1132: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1133: return 1;
1134: }
1135:
1136: /*
1.46 markus 1137: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1138: */
1139: void
1.92 markus 1140: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1141: {
1142: Authctxt *authctxt = ctxt;
1.46 markus 1143: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1144: u_int num_prompts, i;
1.23 markus 1145: int echo = 0;
1146:
1147: debug2("input_userauth_info_req");
1148:
1149: if (authctxt == NULL)
1150: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1151:
1152: authctxt->info_req_seen = 1;
1.23 markus 1153:
1154: name = packet_get_string(NULL);
1155: inst = packet_get_string(NULL);
1156: lang = packet_get_string(NULL);
1157: if (strlen(name) > 0)
1.116 itojun 1158: logit("%s", name);
1.23 markus 1159: if (strlen(inst) > 0)
1.116 itojun 1160: logit("%s", inst);
1.46 markus 1161: xfree(name);
1.23 markus 1162: xfree(inst);
1.46 markus 1163: xfree(lang);
1.23 markus 1164:
1165: num_prompts = packet_get_int();
1166: /*
1167: * Begin to build info response packet based on prompts requested.
1168: * We commit to providing the correct number of responses, so if
1169: * further on we run into a problem that prevents this, we have to
1170: * be sure and clean this up and send a correct error response.
1171: */
1172: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1173: packet_put_int(num_prompts);
1174:
1.73 markus 1175: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1176: for (i = 0; i < num_prompts; i++) {
1177: prompt = packet_get_string(NULL);
1178: echo = packet_get_char();
1179:
1.77 markus 1180: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1181:
1.49 markus 1182: packet_put_cstring(response);
1.23 markus 1183: memset(response, 0, strlen(response));
1184: xfree(response);
1185: xfree(prompt);
1186: }
1.90 markus 1187: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1188:
1.85 markus 1189: packet_add_padding(64);
1.23 markus 1190: packet_send();
1.68 markus 1191: }
1192:
1.100 markus 1193: static int
1.105 deraadt 1194: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1195: u_char *data, u_int datalen)
1196: {
1197: Buffer b;
1.101 markus 1198: struct stat st;
1.100 markus 1199: pid_t pid;
1.103 markus 1200: int to[2], from[2], status, version = 2;
1.100 markus 1201:
1.109 markus 1202: debug2("ssh_keysign called");
1.100 markus 1203:
1.101 markus 1204: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1205: error("ssh_keysign: no installed: %s", strerror(errno));
1206: return -1;
1207: }
1.100 markus 1208: if (fflush(stdout) != 0)
1209: error("ssh_keysign: fflush: %s", strerror(errno));
1210: if (pipe(to) < 0) {
1211: error("ssh_keysign: pipe: %s", strerror(errno));
1212: return -1;
1213: }
1214: if (pipe(from) < 0) {
1215: error("ssh_keysign: pipe: %s", strerror(errno));
1216: return -1;
1217: }
1218: if ((pid = fork()) < 0) {
1219: error("ssh_keysign: fork: %s", strerror(errno));
1220: return -1;
1221: }
1222: if (pid == 0) {
1223: seteuid(getuid());
1224: setuid(getuid());
1225: close(from[0]);
1226: if (dup2(from[1], STDOUT_FILENO) < 0)
1227: fatal("ssh_keysign: dup2: %s", strerror(errno));
1228: close(to[1]);
1229: if (dup2(to[0], STDIN_FILENO) < 0)
1230: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1231: close(from[1]);
1232: close(to[0]);
1.102 markus 1233: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1234: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1235: strerror(errno));
1236: }
1237: close(from[1]);
1238: close(to[0]);
1239:
1240: buffer_init(&b);
1.103 markus 1241: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1242: buffer_put_string(&b, data, datalen);
1.110 djm 1243: ssh_msg_send(to[1], version, &b);
1.100 markus 1244:
1.110 djm 1245: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1246: error("ssh_keysign: no reply");
1.100 markus 1247: buffer_clear(&b);
1248: return -1;
1249: }
1.101 markus 1250: close(from[0]);
1251: close(to[1]);
1252:
1.103 markus 1253: while (waitpid(pid, &status, 0) < 0)
1254: if (errno != EINTR)
1255: break;
1.101 markus 1256:
1.100 markus 1257: if (buffer_get_char(&b) != version) {
1.101 markus 1258: error("ssh_keysign: bad version");
1.100 markus 1259: buffer_clear(&b);
1260: return -1;
1261: }
1262: *sigp = buffer_get_string(&b, lenp);
1263: buffer_clear(&b);
1264:
1265: return 0;
1266: }
1267:
1.68 markus 1268: int
1269: userauth_hostbased(Authctxt *authctxt)
1270: {
1271: Key *private = NULL;
1.100 markus 1272: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1273: Buffer b;
1274: u_char *signature, *blob;
1275: char *chost, *pkalg, *p;
1.72 markus 1276: const char *service;
1.68 markus 1277: u_int blen, slen;
1.71 markus 1278: int ok, i, len, found = 0;
1.68 markus 1279:
1280: /* check for a useful key */
1.100 markus 1281: for (i = 0; i < sensitive->nkeys; i++) {
1282: private = sensitive->keys[i];
1.68 markus 1283: if (private && private->type != KEY_RSA1) {
1284: found = 1;
1285: /* we take and free the key */
1.100 markus 1286: sensitive->keys[i] = NULL;
1.68 markus 1287: break;
1288: }
1289: }
1290: if (!found) {
1.109 markus 1291: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1292: return 0;
1293: }
1294: if (key_to_blob(private, &blob, &blen) == 0) {
1295: key_free(private);
1296: return 0;
1297: }
1.84 markus 1298: /* figure out a name for the client host */
1299: p = get_local_name(packet_get_connection_in());
1300: if (p == NULL) {
1301: error("userauth_hostbased: cannot get local ipaddr/name");
1302: key_free(private);
1303: return 0;
1304: }
1305: len = strlen(p) + 2;
1306: chost = xmalloc(len);
1307: strlcpy(chost, p, len);
1308: strlcat(chost, ".", len);
1309: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1310: xfree(p);
1.84 markus 1311:
1.72 markus 1312: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1313: authctxt->service;
1.68 markus 1314: pkalg = xstrdup(key_ssh_name(private));
1315: buffer_init(&b);
1316: /* construct data */
1.72 markus 1317: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1318: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1319: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1320: buffer_put_cstring(&b, service);
1.68 markus 1321: buffer_put_cstring(&b, authctxt->method->name);
1322: buffer_put_cstring(&b, pkalg);
1323: buffer_put_string(&b, blob, blen);
1324: buffer_put_cstring(&b, chost);
1325: buffer_put_cstring(&b, authctxt->local_user);
1326: #ifdef DEBUG_PK
1327: buffer_dump(&b);
1328: #endif
1.100 markus 1329: if (sensitive->external_keysign)
1330: ok = ssh_keysign(private, &signature, &slen,
1331: buffer_ptr(&b), buffer_len(&b));
1332: else
1333: ok = key_sign(private, &signature, &slen,
1334: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1335: key_free(private);
1336: buffer_free(&b);
1337: if (ok != 0) {
1338: error("key_sign failed");
1339: xfree(chost);
1340: xfree(pkalg);
1341: return 0;
1342: }
1343: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1344: packet_put_cstring(authctxt->server_user);
1345: packet_put_cstring(authctxt->service);
1346: packet_put_cstring(authctxt->method->name);
1347: packet_put_cstring(pkalg);
1348: packet_put_string(blob, blen);
1349: packet_put_cstring(chost);
1350: packet_put_cstring(authctxt->local_user);
1351: packet_put_string(signature, slen);
1352: memset(signature, 's', slen);
1353: xfree(signature);
1354: xfree(chost);
1355: xfree(pkalg);
1356:
1357: packet_send();
1358: return 1;
1.23 markus 1359: }
1.20 markus 1360:
1361: /* find auth method */
1362:
1363: /*
1364: * given auth method name, if configurable options permit this method fill
1365: * in auth_ident field and return true, otherwise return false.
1366: */
1.76 itojun 1367: static int
1.20 markus 1368: authmethod_is_enabled(Authmethod *method)
1369: {
1370: if (method == NULL)
1371: return 0;
1372: /* return false if options indicate this method is disabled */
1373: if (method->enabled == NULL || *method->enabled == 0)
1374: return 0;
1375: /* return false if batch mode is enabled but method needs interactive mode */
1376: if (method->batch_flag != NULL && *method->batch_flag != 0)
1377: return 0;
1378: return 1;
1379: }
1380:
1.76 itojun 1381: static Authmethod *
1.20 markus 1382: authmethod_lookup(const char *name)
1.1 markus 1383: {
1.20 markus 1384: Authmethod *method = NULL;
1385: if (name != NULL)
1386: for (method = authmethods; method->name != NULL; method++)
1387: if (strcmp(name, method->name) == 0)
1388: return method;
1389: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1390: return NULL;
1391: }
1.1 markus 1392:
1.53 markus 1393: /* XXX internal state */
1394: static Authmethod *current = NULL;
1395: static char *supported = NULL;
1396: static char *preferred = NULL;
1.105 deraadt 1397:
1.20 markus 1398: /*
1399: * Given the authentication method list sent by the server, return the
1400: * next method we should try. If the server initially sends a nil list,
1.67 markus 1401: * use a built-in default list.
1.41 stevesk 1402: */
1.76 itojun 1403: static Authmethod *
1.20 markus 1404: authmethod_get(char *authlist)
1405: {
1.53 markus 1406: char *name = NULL;
1.97 markus 1407: u_int next;
1.41 stevesk 1408:
1.20 markus 1409: /* Use a suitable default if we're passed a nil list. */
1410: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1411: authlist = options.preferred_authentications;
1.20 markus 1412:
1.53 markus 1413: if (supported == NULL || strcmp(authlist, supported) != 0) {
1414: debug3("start over, passed a different list %s", authlist);
1415: if (supported != NULL)
1416: xfree(supported);
1417: supported = xstrdup(authlist);
1418: preferred = options.preferred_authentications;
1419: debug3("preferred %s", preferred);
1420: current = NULL;
1421: } else if (current != NULL && authmethod_is_enabled(current))
1422: return current;
1.20 markus 1423:
1.53 markus 1424: for (;;) {
1425: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1426: debug("No more authentication methods to try.");
1.53 markus 1427: current = NULL;
1428: return NULL;
1429: }
1430: preferred += next;
1.23 markus 1431: debug3("authmethod_lookup %s", name);
1.53 markus 1432: debug3("remaining preferred: %s", preferred);
1433: if ((current = authmethod_lookup(name)) != NULL &&
1434: authmethod_is_enabled(current)) {
1.23 markus 1435: debug3("authmethod_is_enabled %s", name);
1.109 markus 1436: debug("Next authentication method: %s", name);
1.53 markus 1437: return current;
1.23 markus 1438: }
1.1 markus 1439: }
1.53 markus 1440: }
1.1 markus 1441:
1.79 stevesk 1442: static char *
1.53 markus 1443: authmethods_get(void)
1444: {
1445: Authmethod *method = NULL;
1.93 markus 1446: Buffer b;
1447: char *list;
1.27 provos 1448:
1.93 markus 1449: buffer_init(&b);
1.53 markus 1450: for (method = authmethods; method->name != NULL; method++) {
1451: if (authmethod_is_enabled(method)) {
1.93 markus 1452: if (buffer_len(&b) > 0)
1453: buffer_append(&b, ",", 1);
1454: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1455: }
1456: }
1.93 markus 1457: buffer_append(&b, "\0", 1);
1458: list = xstrdup(buffer_ptr(&b));
1459: buffer_free(&b);
1460: return list;
1.1 markus 1461: }
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