Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.107.2.2
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"
1.107.2.2! brad 26: RCSID("$OpenBSD: sshconnect2.c,v 1.124 2003/08/25 10:33:33 djm 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:
1.107.2.2! brad 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;
1.107.2.2! brad 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) {
1.107.2.2! brad 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;
1.22 provos 114:
1.107.2.2! brad 115: if (options.rekey_limit)
! 116: packet_set_rekey_limit(options.rekey_limit);
! 117:
1.65 markus 118: /* start key exchange */
1.64 markus 119: kex = kex_setup(myproposal);
1.107.2.1 margarid 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;
1.107.2.2! brad 148: typedef struct identity Identity;
! 149: typedef struct idlist Idlist;
1.20 markus 150:
1.107.2.2! brad 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 */
1.107.2.2! brad 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;
1.107.2.2! brad 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 *);
1.107.2.2! brad 199: int userauth_kerberos(Authctxt *);
! 200:
! 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
1.20 markus 209:
1.86 itojun 210: void userauth(Authctxt *, char *);
1.51 markus 211:
1.107.2.2! brad 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[] = {
1.107.2.2! brad 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();
1.107.2.1 margarid 264: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 265: packet_write_wait();
1.91 markus 266: type = packet_read();
1.107.2.1 margarid 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);
1.107.2.1 margarid 271: debug2("service_accept: %s", reply);
1.20 markus 272: xfree(reply);
273: } else {
1.107.2.1 margarid 274: debug2("buggy server: service_accept w/o service");
1.20 markus 275: }
1.90 markus 276: packet_check_eom();
1.107.2.1 margarid 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));
1.107.2.2! brad 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;
1.107.2.2! brad 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:
1.107.2.2! brad 307: pubkey_cleanup(&authctxt);
! 308: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.20 markus 309:
1.107.2.1 margarid 310: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 311: }
1.107.2.2! brad 312:
1.20 markus 313: void
1.51 markus 314: userauth(Authctxt *authctxt, char *authlist)
315: {
1.107.2.2! brad 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;
1.107.2.2! brad 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);
1.107.2.2! brad 362: logit("%s", msg);
1.35 markus 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);
1.107.2.2! brad 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)
1.107.2.2! brad 395: logit("Authenticated with partial success.");
1.107.2.1 margarid 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;
1.107.2.2! brad 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:
1.107.2.2! brad 428: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 429:
1.107.2.2! brad 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: }
1.107.2.2! brad 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);
1.107.2.2! brad 463: }
! 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: u_int len;
! 649:
! 650: if (authctxt == NULL)
! 651: fatal("input_gssapi_response: no authentication context");
! 652: gssctxt = authctxt->methoddata;
! 653:
! 654: recv_tok.value = packet_get_string(&len);
! 655: recv_tok.length = len;
! 656:
! 657: packet_check_eom();
! 658:
! 659: /* Stick it into GSSAPI and see what it says */
! 660: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
! 661: &recv_tok, &send_tok, NULL);
1.51 markus 662:
1.107.2.2! brad 663: xfree(recv_tok.value);
! 664: gss_release_buffer(&ms, &send_tok);
! 665:
! 666: /* Server will be returning a failed packet after this one */
1.20 markus 667: }
668:
1.107.2.2! brad 669: void
! 670: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
! 671: {
! 672: OM_uint32 maj, min;
! 673: char *msg;
! 674: char *lang;
! 675:
! 676: maj=packet_get_int();
! 677: min=packet_get_int();
! 678: msg=packet_get_string(NULL);
! 679: lang=packet_get_string(NULL);
! 680:
! 681: packet_check_eom();
! 682:
! 683: debug("Server GSSAPI Error:\n%s\n", msg);
! 684: xfree(msg);
! 685: xfree(lang);
! 686: }
! 687: #endif /* GSSAPI */
! 688:
1.1 markus 689: int
1.23 markus 690: userauth_none(Authctxt *authctxt)
691: {
692: /* initial userauth request */
693: packet_start(SSH2_MSG_USERAUTH_REQUEST);
694: packet_put_cstring(authctxt->server_user);
695: packet_put_cstring(authctxt->service);
696: packet_put_cstring(authctxt->method->name);
697: packet_send();
698: return 1;
699: }
700:
701: int
1.20 markus 702: userauth_passwd(Authctxt *authctxt)
1.1 markus 703: {
1.6 markus 704: static int attempt = 0;
1.99 markus 705: char prompt[150];
1.1 markus 706: char *password;
1.6 markus 707:
1.13 todd 708: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 709: return 0;
1.13 todd 710:
1.87 deraadt 711: if (attempt != 1)
1.13 todd 712: error("Permission denied, please try again.");
1.1 markus 713:
1.43 itojun 714: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 715: authctxt->server_user, authctxt->host);
1.1 markus 716: password = read_passphrase(prompt, 0);
717: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 718: packet_put_cstring(authctxt->server_user);
719: packet_put_cstring(authctxt->service);
1.23 markus 720: packet_put_cstring(authctxt->method->name);
1.1 markus 721: packet_put_char(0);
1.49 markus 722: packet_put_cstring(password);
1.1 markus 723: memset(password, 0, strlen(password));
724: xfree(password);
1.85 markus 725: packet_add_padding(64);
1.1 markus 726: packet_send();
1.99 markus 727:
1.104 deraadt 728: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 729: &input_userauth_passwd_changereq);
730:
1.1 markus 731: return 1;
732: }
1.99 markus 733: /*
734: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
735: */
736: void
737: input_userauth_passwd_changereq(int type, uint32_t seqnr, void *ctxt)
738: {
739: Authctxt *authctxt = ctxt;
740: char *info, *lang, *password = NULL, *retype = NULL;
741: char prompt[150];
742:
743: debug2("input_userauth_passwd_changereq");
744:
745: if (authctxt == NULL)
746: fatal("input_userauth_passwd_changereq: "
747: "no authentication context");
748:
749: info = packet_get_string(NULL);
750: lang = packet_get_string(NULL);
751: if (strlen(info) > 0)
1.107.2.2! brad 752: logit("%s", info);
1.99 markus 753: xfree(info);
754: xfree(lang);
755: packet_start(SSH2_MSG_USERAUTH_REQUEST);
756: packet_put_cstring(authctxt->server_user);
757: packet_put_cstring(authctxt->service);
758: packet_put_cstring(authctxt->method->name);
759: packet_put_char(1); /* additional info */
1.104 deraadt 760: snprintf(prompt, sizeof(prompt),
1.99 markus 761: "Enter %.30s@%.128s's old password: ",
762: authctxt->server_user, authctxt->host);
763: password = read_passphrase(prompt, 0);
764: packet_put_cstring(password);
765: memset(password, 0, strlen(password));
766: xfree(password);
767: password = NULL;
768: while (password == NULL) {
1.104 deraadt 769: snprintf(prompt, sizeof(prompt),
1.99 markus 770: "Enter %.30s@%.128s's new password: ",
771: authctxt->server_user, authctxt->host);
772: password = read_passphrase(prompt, RP_ALLOW_EOF);
773: if (password == NULL) {
774: /* bail out */
775: return;
776: }
1.104 deraadt 777: snprintf(prompt, sizeof(prompt),
1.99 markus 778: "Retype %.30s@%.128s's new password: ",
779: authctxt->server_user, authctxt->host);
780: retype = read_passphrase(prompt, 0);
781: if (strcmp(password, retype) != 0) {
782: memset(password, 0, strlen(password));
783: xfree(password);
1.107.2.2! brad 784: logit("Mismatch; try again, EOF to quit.");
1.99 markus 785: password = NULL;
786: }
787: memset(retype, 0, strlen(retype));
788: xfree(retype);
789: }
790: packet_put_cstring(password);
791: memset(password, 0, strlen(password));
792: xfree(password);
793: packet_add_padding(64);
794: packet_send();
1.104 deraadt 795:
796: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 797: &input_userauth_passwd_changereq);
798: }
1.1 markus 799:
1.107.2.2! brad 800: static int
! 801: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
! 802: u_char *data, u_int datalen)
1.51 markus 803: {
1.107.2.2! brad 804: Key *prv;
! 805: int ret;
1.99 markus 806:
1.107.2.2! brad 807: /* the agent supports this key */
! 808: if (id->ac)
! 809: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
! 810: data, datalen));
! 811: /*
! 812: * we have already loaded the private key or
! 813: * the private key is stored in external hardware
! 814: */
! 815: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
! 816: return (key_sign(id->key, sigp, lenp, data, datalen));
! 817: /* load the private key from the file */
! 818: if ((prv = load_identity_file(id->filename)) == NULL)
! 819: return (-1);
! 820: ret = key_sign(prv, sigp, lenp, data, datalen);
! 821: key_free(prv);
! 822: return (ret);
1.51 markus 823: }
824:
1.76 itojun 825: static int
1.107.2.2! brad 826: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 827: {
828: Buffer b;
1.32 markus 829: u_char *blob, *signature;
1.96 markus 830: u_int bloblen, slen;
1.107.2.2! brad 831: u_int skip = 0;
1.17 markus 832: int ret = -1;
1.23 markus 833: int have_sig = 1;
1.1 markus 834:
1.30 markus 835: debug3("sign_and_send_pubkey");
1.51 markus 836:
1.107.2.2! brad 837: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 838: /* we cannot handle this key */
1.30 markus 839: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 840: return 0;
841: }
1.1 markus 842: /* data to be signed */
843: buffer_init(&b);
1.26 markus 844: if (datafellows & SSH_OLD_SESSIONID) {
845: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 846: skip = session_id2_len;
1.26 markus 847: } else {
1.14 markus 848: buffer_put_string(&b, session_id2, session_id2_len);
849: skip = buffer_len(&b);
850: }
1.1 markus 851: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 852: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 853: buffer_put_cstring(&b,
1.30 markus 854: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 855: "ssh-userauth" :
1.20 markus 856: authctxt->service);
1.30 markus 857: if (datafellows & SSH_BUG_PKAUTH) {
858: buffer_put_char(&b, have_sig);
859: } else {
860: buffer_put_cstring(&b, authctxt->method->name);
861: buffer_put_char(&b, have_sig);
1.107.2.2! brad 862: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 863: }
1.1 markus 864: buffer_put_string(&b, blob, bloblen);
865:
866: /* generate signature */
1.107.2.2! brad 867: ret = identity_sign(id, &signature, &slen,
1.51 markus 868: buffer_ptr(&b), buffer_len(&b));
1.17 markus 869: if (ret == -1) {
870: xfree(blob);
871: buffer_free(&b);
872: return 0;
873: }
1.28 markus 874: #ifdef DEBUG_PK
1.1 markus 875: buffer_dump(&b);
876: #endif
1.30 markus 877: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 878: buffer_clear(&b);
879: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 880: skip = session_id2_len;
1.10 markus 881: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 882: buffer_put_cstring(&b, authctxt->server_user);
883: buffer_put_cstring(&b, authctxt->service);
1.23 markus 884: buffer_put_cstring(&b, authctxt->method->name);
885: buffer_put_char(&b, have_sig);
1.30 markus 886: if (!(datafellows & SSH_BUG_PKAUTH))
1.107.2.2! brad 887: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 888: buffer_put_string(&b, blob, bloblen);
889: }
890: xfree(blob);
1.51 markus 891:
1.1 markus 892: /* append signature */
893: buffer_put_string(&b, signature, slen);
894: xfree(signature);
895:
896: /* skip session id and packet type */
1.14 markus 897: if (buffer_len(&b) < skip + 1)
1.20 markus 898: fatal("userauth_pubkey: internal error");
1.14 markus 899: buffer_consume(&b, skip + 1);
1.1 markus 900:
901: /* put remaining data from buffer into packet */
902: packet_start(SSH2_MSG_USERAUTH_REQUEST);
903: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
904: buffer_free(&b);
905: packet_send();
1.17 markus 906:
907: return 1;
1.16 markus 908: }
909:
1.76 itojun 910: static int
1.107.2.2! brad 911: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 912: {
1.51 markus 913: u_char *blob;
1.97 markus 914: u_int bloblen, have_sig = 0;
1.20 markus 915:
1.51 markus 916: debug3("send_pubkey_test");
1.16 markus 917:
1.107.2.2! brad 918: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 919: /* we cannot handle this key */
920: debug3("send_pubkey_test: cannot handle key");
1.16 markus 921: return 0;
922: }
1.51 markus 923: /* register callback for USERAUTH_PK_OK message */
924: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
925:
926: packet_start(SSH2_MSG_USERAUTH_REQUEST);
927: packet_put_cstring(authctxt->server_user);
928: packet_put_cstring(authctxt->service);
929: packet_put_cstring(authctxt->method->name);
930: packet_put_char(have_sig);
931: if (!(datafellows & SSH_BUG_PKAUTH))
1.107.2.2! brad 932: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 933: packet_put_string(blob, bloblen);
934: xfree(blob);
935: packet_send();
936: return 1;
937: }
938:
1.76 itojun 939: static Key *
1.51 markus 940: load_identity_file(char *filename)
941: {
942: Key *private;
943: char prompt[300], *passphrase;
1.56 markus 944: int quit, i;
1.52 markus 945: struct stat st;
1.16 markus 946:
1.52 markus 947: if (stat(filename, &st) < 0) {
948: debug3("no such identity: %s", filename);
949: return NULL;
950: }
1.56 markus 951: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL);
952: if (private == NULL) {
953: if (options.batch_mode)
1.51 markus 954: return NULL;
1.16 markus 955: snprintf(prompt, sizeof prompt,
1.88 deraadt 956: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 957: for (i = 0; i < options.number_of_password_prompts; i++) {
958: passphrase = read_passphrase(prompt, 0);
959: if (strcmp(passphrase, "") != 0) {
1.56 markus 960: private = key_load_private_type(KEY_UNSPEC, filename,
961: passphrase, NULL);
1.51 markus 962: quit = 0;
1.20 markus 963: } else {
964: debug2("no passphrase given, try next key");
1.51 markus 965: quit = 1;
1.20 markus 966: }
967: memset(passphrase, 0, strlen(passphrase));
968: xfree(passphrase);
1.56 markus 969: if (private != NULL || quit)
1.20 markus 970: break;
971: debug2("bad passphrase given, try again...");
1.16 markus 972: }
973: }
1.51 markus 974: return private;
975: }
976:
1.107.2.2! brad 977: /*
! 978: * try keys in the following order:
! 979: * 1. agent keys that are found in the config file
! 980: * 2. other agent keys
! 981: * 3. keys that are only listed in the config file
! 982: */
! 983: static void
! 984: pubkey_prepare(Authctxt *authctxt)
1.17 markus 985: {
1.107.2.2! brad 986: Identity *id;
! 987: Idlist agent, files, *preferred;
! 988: Key *key;
! 989: AuthenticationConnection *ac;
! 990: char *comment;
! 991: int i, found;
1.17 markus 992:
1.107.2.2! brad 993: TAILQ_INIT(&agent); /* keys from the agent */
! 994: TAILQ_INIT(&files); /* keys from the config file */
! 995: preferred = &authctxt->keys;
! 996: TAILQ_INIT(preferred); /* preferred order of keys */
! 997:
! 998: /* list of keys stored in the filesystem */
! 999: for (i = 0; i < options.num_identity_files; i++) {
! 1000: key = options.identity_keys[i];
! 1001: if (key && key->type == KEY_RSA1)
! 1002: continue;
! 1003: options.identity_keys[i] = NULL;
! 1004: id = xmalloc(sizeof(*id));
! 1005: memset(id, 0, sizeof(*id));
! 1006: id->key = key;
! 1007: id->filename = xstrdup(options.identity_files[i]);
! 1008: TAILQ_INSERT_TAIL(&files, id, next);
! 1009: }
! 1010: /* list of keys supported by the agent */
! 1011: if ((ac = ssh_get_authentication_connection())) {
! 1012: for (key = ssh_get_first_identity(ac, &comment, 2);
! 1013: key != NULL;
! 1014: key = ssh_get_next_identity(ac, &comment, 2)) {
! 1015: found = 0;
! 1016: TAILQ_FOREACH(id, &files, next) {
! 1017: /* agent keys from the config file are preferred */
! 1018: if (key_equal(key, id->key)) {
! 1019: key_free(key);
! 1020: xfree(comment);
! 1021: TAILQ_REMOVE(&files, id, next);
! 1022: TAILQ_INSERT_TAIL(preferred, id, next);
! 1023: id->ac = ac;
! 1024: found = 1;
! 1025: break;
! 1026: }
! 1027: }
! 1028: if (!found) {
! 1029: id = xmalloc(sizeof(*id));
! 1030: memset(id, 0, sizeof(*id));
! 1031: id->key = key;
! 1032: id->filename = comment;
! 1033: id->ac = ac;
! 1034: TAILQ_INSERT_TAIL(&agent, id, next);
! 1035: }
! 1036: }
! 1037: /* append remaining agent keys */
! 1038: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
! 1039: TAILQ_REMOVE(&agent, id, next);
! 1040: TAILQ_INSERT_TAIL(preferred, id, next);
! 1041: }
! 1042: authctxt->agent = ac;
! 1043: }
! 1044: /* append remaining keys from the config file */
! 1045: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
! 1046: TAILQ_REMOVE(&files, id, next);
! 1047: TAILQ_INSERT_TAIL(preferred, id, next);
! 1048: }
! 1049: TAILQ_FOREACH(id, preferred, next) {
! 1050: debug2("key: %s (%p)", id->filename, id->key);
! 1051: }
1.51 markus 1052: }
1053:
1.107.2.2! brad 1054: static void
! 1055: pubkey_cleanup(Authctxt *authctxt)
1.17 markus 1056: {
1.107.2.2! brad 1057: Identity *id;
1.17 markus 1058:
1.107.2.2! brad 1059: if (authctxt->agent != NULL)
! 1060: ssh_close_authentication_connection(authctxt->agent);
! 1061: for (id = TAILQ_FIRST(&authctxt->keys); id;
! 1062: id = TAILQ_FIRST(&authctxt->keys)) {
! 1063: TAILQ_REMOVE(&authctxt->keys, id, next);
! 1064: if (id->key)
! 1065: key_free(id->key);
! 1066: if (id->filename)
! 1067: xfree(id->filename);
! 1068: xfree(id);
! 1069: }
1.1 markus 1070: }
1071:
1.20 markus 1072: int
1073: userauth_pubkey(Authctxt *authctxt)
1074: {
1.107.2.2! brad 1075: Identity *id;
1.20 markus 1076: int sent = 0;
1077:
1.107.2.2! brad 1078: while ((id = TAILQ_FIRST(&authctxt->keys))) {
! 1079: if (id->tried++)
! 1080: return (0);
! 1081: TAILQ_REMOVE(&authctxt->keys, id, next);
! 1082: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
! 1083: /*
! 1084: * send a test message if we have the public key. for
! 1085: * encrypted keys we cannot do this and have to load the
! 1086: * private key instead
! 1087: */
! 1088: if (id->key && id->key->type != KEY_RSA1) {
! 1089: debug("Offering public key: %s", id->filename);
! 1090: sent = send_pubkey_test(authctxt, id);
! 1091: } else if (id->key == NULL) {
! 1092: debug("Trying private key: %s", id->filename);
! 1093: id->key = load_identity_file(id->filename);
! 1094: if (id->key != NULL) {
! 1095: id->isprivate = 1;
! 1096: sent = sign_and_send_pubkey(authctxt, id);
! 1097: key_free(id->key);
! 1098: id->key = NULL;
1.51 markus 1099: }
1100: }
1.107.2.2! brad 1101: if (sent)
! 1102: return (sent);
1.28 markus 1103: }
1.107.2.2! brad 1104: return (0);
1.20 markus 1105: }
1106:
1.23 markus 1107: /*
1108: * Send userauth request message specifying keyboard-interactive method.
1109: */
1110: int
1111: userauth_kbdint(Authctxt *authctxt)
1112: {
1113: static int attempt = 0;
1114:
1115: if (attempt++ >= options.number_of_password_prompts)
1116: return 0;
1.82 markus 1117: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1118: if (attempt > 1 && !authctxt->info_req_seen) {
1119: debug3("userauth_kbdint: disable: no info_req_seen");
1120: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1121: return 0;
1122: }
1.23 markus 1123:
1124: debug2("userauth_kbdint");
1125: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1126: packet_put_cstring(authctxt->server_user);
1127: packet_put_cstring(authctxt->service);
1128: packet_put_cstring(authctxt->method->name);
1129: packet_put_cstring(""); /* lang */
1130: packet_put_cstring(options.kbd_interactive_devices ?
1131: options.kbd_interactive_devices : "");
1132: packet_send();
1133:
1134: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1135: return 1;
1136: }
1137:
1138: /*
1.46 markus 1139: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1140: */
1141: void
1.92 markus 1142: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1143: {
1144: Authctxt *authctxt = ctxt;
1.46 markus 1145: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1146: u_int num_prompts, i;
1.23 markus 1147: int echo = 0;
1148:
1149: debug2("input_userauth_info_req");
1150:
1151: if (authctxt == NULL)
1152: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1153:
1154: authctxt->info_req_seen = 1;
1.23 markus 1155:
1156: name = packet_get_string(NULL);
1157: inst = packet_get_string(NULL);
1158: lang = packet_get_string(NULL);
1159: if (strlen(name) > 0)
1.107.2.2! brad 1160: logit("%s", name);
1.23 markus 1161: if (strlen(inst) > 0)
1.107.2.2! brad 1162: logit("%s", inst);
1.46 markus 1163: xfree(name);
1.23 markus 1164: xfree(inst);
1.46 markus 1165: xfree(lang);
1.23 markus 1166:
1167: num_prompts = packet_get_int();
1168: /*
1169: * Begin to build info response packet based on prompts requested.
1170: * We commit to providing the correct number of responses, so if
1171: * further on we run into a problem that prevents this, we have to
1172: * be sure and clean this up and send a correct error response.
1173: */
1174: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1175: packet_put_int(num_prompts);
1176:
1.73 markus 1177: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1178: for (i = 0; i < num_prompts; i++) {
1179: prompt = packet_get_string(NULL);
1180: echo = packet_get_char();
1181:
1.77 markus 1182: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1183:
1.49 markus 1184: packet_put_cstring(response);
1.23 markus 1185: memset(response, 0, strlen(response));
1186: xfree(response);
1187: xfree(prompt);
1188: }
1.90 markus 1189: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1190:
1.85 markus 1191: packet_add_padding(64);
1.23 markus 1192: packet_send();
1.68 markus 1193: }
1194:
1.100 markus 1195: static int
1.105 deraadt 1196: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1197: u_char *data, u_int datalen)
1198: {
1199: Buffer b;
1.101 markus 1200: struct stat st;
1.100 markus 1201: pid_t pid;
1.103 markus 1202: int to[2], from[2], status, version = 2;
1.100 markus 1203:
1.107.2.1 margarid 1204: debug2("ssh_keysign called");
1.100 markus 1205:
1.101 markus 1206: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1207: error("ssh_keysign: no installed: %s", strerror(errno));
1208: return -1;
1209: }
1.100 markus 1210: if (fflush(stdout) != 0)
1211: error("ssh_keysign: fflush: %s", strerror(errno));
1212: if (pipe(to) < 0) {
1213: error("ssh_keysign: pipe: %s", strerror(errno));
1214: return -1;
1215: }
1216: if (pipe(from) < 0) {
1217: error("ssh_keysign: pipe: %s", strerror(errno));
1218: return -1;
1219: }
1220: if ((pid = fork()) < 0) {
1221: error("ssh_keysign: fork: %s", strerror(errno));
1222: return -1;
1223: }
1224: if (pid == 0) {
1225: seteuid(getuid());
1226: setuid(getuid());
1227: close(from[0]);
1228: if (dup2(from[1], STDOUT_FILENO) < 0)
1229: fatal("ssh_keysign: dup2: %s", strerror(errno));
1230: close(to[1]);
1231: if (dup2(to[0], STDIN_FILENO) < 0)
1232: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1233: close(from[1]);
1234: close(to[0]);
1.102 markus 1235: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1236: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1237: strerror(errno));
1238: }
1239: close(from[1]);
1240: close(to[0]);
1241:
1242: buffer_init(&b);
1.103 markus 1243: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1244: buffer_put_string(&b, data, datalen);
1.107.2.1 margarid 1245: ssh_msg_send(to[1], version, &b);
1.100 markus 1246:
1.107.2.1 margarid 1247: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1248: error("ssh_keysign: no reply");
1.100 markus 1249: buffer_clear(&b);
1250: return -1;
1251: }
1.101 markus 1252: close(from[0]);
1253: close(to[1]);
1254:
1.103 markus 1255: while (waitpid(pid, &status, 0) < 0)
1256: if (errno != EINTR)
1257: break;
1.101 markus 1258:
1.100 markus 1259: if (buffer_get_char(&b) != version) {
1.101 markus 1260: error("ssh_keysign: bad version");
1.100 markus 1261: buffer_clear(&b);
1262: return -1;
1263: }
1264: *sigp = buffer_get_string(&b, lenp);
1265: buffer_clear(&b);
1266:
1267: return 0;
1268: }
1269:
1.68 markus 1270: int
1271: userauth_hostbased(Authctxt *authctxt)
1272: {
1273: Key *private = NULL;
1.100 markus 1274: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1275: Buffer b;
1276: u_char *signature, *blob;
1277: char *chost, *pkalg, *p;
1.72 markus 1278: const char *service;
1.68 markus 1279: u_int blen, slen;
1.71 markus 1280: int ok, i, len, found = 0;
1.68 markus 1281:
1282: /* check for a useful key */
1.100 markus 1283: for (i = 0; i < sensitive->nkeys; i++) {
1284: private = sensitive->keys[i];
1.68 markus 1285: if (private && private->type != KEY_RSA1) {
1286: found = 1;
1287: /* we take and free the key */
1.100 markus 1288: sensitive->keys[i] = NULL;
1.68 markus 1289: break;
1290: }
1291: }
1292: if (!found) {
1.107.2.1 margarid 1293: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1294: return 0;
1295: }
1296: if (key_to_blob(private, &blob, &blen) == 0) {
1297: key_free(private);
1298: return 0;
1299: }
1.84 markus 1300: /* figure out a name for the client host */
1301: p = get_local_name(packet_get_connection_in());
1302: if (p == NULL) {
1303: error("userauth_hostbased: cannot get local ipaddr/name");
1304: key_free(private);
1305: return 0;
1306: }
1307: len = strlen(p) + 2;
1308: chost = xmalloc(len);
1309: strlcpy(chost, p, len);
1310: strlcat(chost, ".", len);
1311: debug2("userauth_hostbased: chost %s", chost);
1.107.2.1 margarid 1312: xfree(p);
1.84 markus 1313:
1.72 markus 1314: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1315: authctxt->service;
1.68 markus 1316: pkalg = xstrdup(key_ssh_name(private));
1317: buffer_init(&b);
1318: /* construct data */
1.72 markus 1319: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1320: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1321: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1322: buffer_put_cstring(&b, service);
1.68 markus 1323: buffer_put_cstring(&b, authctxt->method->name);
1324: buffer_put_cstring(&b, pkalg);
1325: buffer_put_string(&b, blob, blen);
1326: buffer_put_cstring(&b, chost);
1327: buffer_put_cstring(&b, authctxt->local_user);
1328: #ifdef DEBUG_PK
1329: buffer_dump(&b);
1330: #endif
1.100 markus 1331: if (sensitive->external_keysign)
1332: ok = ssh_keysign(private, &signature, &slen,
1333: buffer_ptr(&b), buffer_len(&b));
1334: else
1335: ok = key_sign(private, &signature, &slen,
1336: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1337: key_free(private);
1338: buffer_free(&b);
1339: if (ok != 0) {
1340: error("key_sign failed");
1341: xfree(chost);
1342: xfree(pkalg);
1343: return 0;
1344: }
1345: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1346: packet_put_cstring(authctxt->server_user);
1347: packet_put_cstring(authctxt->service);
1348: packet_put_cstring(authctxt->method->name);
1349: packet_put_cstring(pkalg);
1350: packet_put_string(blob, blen);
1351: packet_put_cstring(chost);
1352: packet_put_cstring(authctxt->local_user);
1353: packet_put_string(signature, slen);
1354: memset(signature, 's', slen);
1355: xfree(signature);
1356: xfree(chost);
1357: xfree(pkalg);
1358:
1359: packet_send();
1360: return 1;
1.23 markus 1361: }
1.20 markus 1362:
1363: /* find auth method */
1364:
1365: /*
1366: * given auth method name, if configurable options permit this method fill
1367: * in auth_ident field and return true, otherwise return false.
1368: */
1.76 itojun 1369: static int
1.20 markus 1370: authmethod_is_enabled(Authmethod *method)
1371: {
1372: if (method == NULL)
1373: return 0;
1374: /* return false if options indicate this method is disabled */
1375: if (method->enabled == NULL || *method->enabled == 0)
1376: return 0;
1377: /* return false if batch mode is enabled but method needs interactive mode */
1378: if (method->batch_flag != NULL && *method->batch_flag != 0)
1379: return 0;
1380: return 1;
1381: }
1382:
1.76 itojun 1383: static Authmethod *
1.20 markus 1384: authmethod_lookup(const char *name)
1.1 markus 1385: {
1.20 markus 1386: Authmethod *method = NULL;
1387: if (name != NULL)
1388: for (method = authmethods; method->name != NULL; method++)
1389: if (strcmp(name, method->name) == 0)
1390: return method;
1391: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1392: return NULL;
1393: }
1.1 markus 1394:
1.53 markus 1395: /* XXX internal state */
1396: static Authmethod *current = NULL;
1397: static char *supported = NULL;
1398: static char *preferred = NULL;
1.105 deraadt 1399:
1.20 markus 1400: /*
1401: * Given the authentication method list sent by the server, return the
1402: * next method we should try. If the server initially sends a nil list,
1.67 markus 1403: * use a built-in default list.
1.41 stevesk 1404: */
1.76 itojun 1405: static Authmethod *
1.20 markus 1406: authmethod_get(char *authlist)
1407: {
1.53 markus 1408: char *name = NULL;
1.97 markus 1409: u_int next;
1.41 stevesk 1410:
1.20 markus 1411: /* Use a suitable default if we're passed a nil list. */
1412: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1413: authlist = options.preferred_authentications;
1.20 markus 1414:
1.53 markus 1415: if (supported == NULL || strcmp(authlist, supported) != 0) {
1416: debug3("start over, passed a different list %s", authlist);
1417: if (supported != NULL)
1418: xfree(supported);
1419: supported = xstrdup(authlist);
1420: preferred = options.preferred_authentications;
1421: debug3("preferred %s", preferred);
1422: current = NULL;
1423: } else if (current != NULL && authmethod_is_enabled(current))
1424: return current;
1.20 markus 1425:
1.53 markus 1426: for (;;) {
1427: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.107.2.1 margarid 1428: debug("No more authentication methods to try.");
1.53 markus 1429: current = NULL;
1430: return NULL;
1431: }
1432: preferred += next;
1.23 markus 1433: debug3("authmethod_lookup %s", name);
1.53 markus 1434: debug3("remaining preferred: %s", preferred);
1435: if ((current = authmethod_lookup(name)) != NULL &&
1436: authmethod_is_enabled(current)) {
1.23 markus 1437: debug3("authmethod_is_enabled %s", name);
1.107.2.1 margarid 1438: debug("Next authentication method: %s", name);
1.53 markus 1439: return current;
1.23 markus 1440: }
1.1 markus 1441: }
1.53 markus 1442: }
1.1 markus 1443:
1.79 stevesk 1444: static char *
1.53 markus 1445: authmethods_get(void)
1446: {
1447: Authmethod *method = NULL;
1.93 markus 1448: Buffer b;
1449: char *list;
1.27 provos 1450:
1.93 markus 1451: buffer_init(&b);
1.53 markus 1452: for (method = authmethods; method->name != NULL; method++) {
1453: if (authmethod_is_enabled(method)) {
1.93 markus 1454: if (buffer_len(&b) > 0)
1455: buffer_append(&b, ",", 1);
1456: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1457: }
1458: }
1.93 markus 1459: buffer_append(&b, "\0", 1);
1460: list = xstrdup(buffer_ptr(&b));
1461: buffer_free(&b);
1462: return list;
1.1 markus 1463: }
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