Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.157
1.157 ! stevesk 1: /* $OpenBSD: sshconnect2.c,v 1.156 2006/07/11 20:07:25 stevesk Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: *
14: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24: */
25:
26: #include "includes.h"
1.144 stevesk 27:
1.145 stevesk 28: #include <sys/types.h>
29: #include <sys/wait.h>
1.144 stevesk 30: #include <sys/queue.h>
1.146 stevesk 31: #include <sys/stat.h>
1.156 stevesk 32:
33: #include <errno.h>
1.157 ! stevesk 34: #include <unistd.h>
1.1 markus 35:
36: #include "ssh.h"
1.37 markus 37: #include "ssh2.h"
1.1 markus 38: #include "xmalloc.h"
39: #include "buffer.h"
40: #include "packet.h"
41: #include "compat.h"
42: #include "bufaux.h"
1.37 markus 43: #include "cipher.h"
1.1 markus 44: #include "kex.h"
45: #include "myproposal.h"
46: #include "sshconnect.h"
47: #include "authfile.h"
1.57 provos 48: #include "dh.h"
1.17 markus 49: #include "authfd.h"
1.37 markus 50: #include "log.h"
51: #include "readconf.h"
1.137 djm 52: #include "misc.h"
1.53 markus 53: #include "match.h"
1.61 markus 54: #include "dispatch.h"
1.68 markus 55: #include "canohost.h"
1.100 markus 56: #include "msg.h"
57: #include "pathnames.h"
1.154 markus 58: #include "uidswap.h"
1.22 provos 59:
1.121 markus 60: #ifdef GSSAPI
61: #include "ssh-gss.h"
62: #endif
63:
1.1 markus 64: /* import */
65: extern char *client_version_string;
66: extern char *server_version_string;
67: extern Options options;
68:
69: /*
70: * SSH2 key exchange
71: */
72:
1.32 markus 73: u_char *session_id2 = NULL;
1.120 markus 74: u_int session_id2_len = 0;
1.1 markus 75:
1.61 markus 76: char *xxx_host;
77: struct sockaddr *xxx_hostaddr;
78:
1.63 markus 79: Kex *xxx_kex = NULL;
80:
1.76 itojun 81: static int
1.75 markus 82: verify_host_key_callback(Key *hostkey)
1.61 markus 83: {
1.75 markus 84: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 85: fatal("Host key verification failed.");
1.61 markus 86: return 0;
87: }
88:
1.1 markus 89: void
1.22 provos 90: ssh_kex2(char *host, struct sockaddr *hostaddr)
91: {
92: Kex *kex;
1.61 markus 93:
94: xxx_host = host;
95: xxx_hostaddr = hostaddr;
1.22 provos 96:
1.29 markus 97: if (options.ciphers == (char *)-1) {
1.116 itojun 98: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 99: options.ciphers = NULL;
1.24 markus 100: }
1.22 provos 101: if (options.ciphers != NULL) {
102: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
103: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
104: }
1.60 stevesk 105: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
106: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
107: myproposal[PROPOSAL_ENC_ALGS_STOC] =
108: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 109: if (options.compression) {
1.47 markus 110: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 111: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 112: } else {
1.47 markus 113: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 114: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 115: }
116: if (options.macs != NULL) {
117: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
118: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 119: }
1.70 markus 120: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 121: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 122: options.hostkeyalgorithms;
1.115 markus 123:
124: if (options.rekey_limit)
125: packet_set_rekey_limit(options.rekey_limit);
1.22 provos 126:
1.65 markus 127: /* start key exchange */
1.64 markus 128: kex = kex_setup(myproposal);
1.111 markus 129: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 130: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 131: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 132: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.61 markus 133: kex->client_version_string=client_version_string;
134: kex->server_version_string=server_version_string;
1.75 markus 135: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 136:
137: xxx_kex = kex;
1.22 provos 138:
1.66 markus 139: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.62 markus 140:
141: session_id2 = kex->session_id;
142: session_id2_len = kex->session_id_len;
1.22 provos 143:
144: #ifdef DEBUG_KEXDH
145: /* send 1st encrypted/maced/compressed message */
146: packet_start(SSH2_MSG_IGNORE);
147: packet_put_cstring("markus");
148: packet_send();
149: packet_write_wait();
150: #endif
1.1 markus 151: }
1.11 markus 152:
1.1 markus 153: /*
154: * Authenticate user
155: */
1.20 markus 156:
157: typedef struct Authctxt Authctxt;
158: typedef struct Authmethod Authmethod;
1.117 markus 159: typedef struct identity Identity;
160: typedef struct idlist Idlist;
1.20 markus 161:
1.117 markus 162: struct identity {
163: TAILQ_ENTRY(identity) next;
164: AuthenticationConnection *ac; /* set if agent supports key */
165: Key *key; /* public/private key */
166: char *filename; /* comment for agent-only keys */
167: int tried;
168: int isprivate; /* key points to the private key */
169: };
170: TAILQ_HEAD(idlist, identity);
1.20 markus 171:
172: struct Authctxt {
173: const char *server_user;
1.68 markus 174: const char *local_user;
1.20 markus 175: const char *host;
176: const char *service;
1.23 markus 177: Authmethod *method;
1.20 markus 178: int success;
1.51 markus 179: char *authlist;
1.68 markus 180: /* pubkey */
1.117 markus 181: Idlist keys;
1.68 markus 182: AuthenticationConnection *agent;
183: /* hostbased */
1.100 markus 184: Sensitive *sensitive;
1.82 markus 185: /* kbd-interactive */
186: int info_req_seen;
1.121 markus 187: /* generic */
188: void *methoddata;
1.20 markus 189: };
190: struct Authmethod {
191: char *name; /* string to compare against server's list */
192: int (*userauth)(Authctxt *authctxt);
193: int *enabled; /* flag in option struct that enables method */
194: int *batch_flag; /* flag in option struct that disables method */
195: };
196:
1.92 markus 197: void input_userauth_success(int, u_int32_t, void *);
198: void input_userauth_failure(int, u_int32_t, void *);
199: void input_userauth_banner(int, u_int32_t, void *);
200: void input_userauth_error(int, u_int32_t, void *);
201: void input_userauth_info_req(int, u_int32_t, void *);
202: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 203: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 204:
205: int userauth_none(Authctxt *);
206: int userauth_pubkey(Authctxt *);
207: int userauth_passwd(Authctxt *);
208: int userauth_kbdint(Authctxt *);
209: int userauth_hostbased(Authctxt *);
1.118 markus 210: int userauth_kerberos(Authctxt *);
1.20 markus 211:
1.121 markus 212: #ifdef GSSAPI
213: int userauth_gssapi(Authctxt *authctxt);
214: void input_gssapi_response(int type, u_int32_t, void *);
215: void input_gssapi_token(int type, u_int32_t, void *);
216: void input_gssapi_hash(int type, u_int32_t, void *);
217: void input_gssapi_error(int, u_int32_t, void *);
218: void input_gssapi_errtok(int, u_int32_t, void *);
219: #endif
220:
1.86 itojun 221: void userauth(Authctxt *, char *);
1.51 markus 222:
1.117 markus 223: static int sign_and_send_pubkey(Authctxt *, Identity *);
224: static void pubkey_prepare(Authctxt *);
225: static void pubkey_cleanup(Authctxt *);
226: static Key *load_identity_file(char *);
1.76 itojun 227:
228: static Authmethod *authmethod_get(char *authlist);
229: static Authmethod *authmethod_lookup(const char *name);
230: static char *authmethods_get(void);
1.20 markus 231:
232: Authmethod authmethods[] = {
1.121 markus 233: #ifdef GSSAPI
1.132 markus 234: {"gssapi-with-mic",
1.121 markus 235: userauth_gssapi,
236: &options.gss_authentication,
237: NULL},
238: #endif
1.81 markus 239: {"hostbased",
240: userauth_hostbased,
241: &options.hostbased_authentication,
242: NULL},
1.20 markus 243: {"publickey",
244: userauth_pubkey,
1.28 markus 245: &options.pubkey_authentication,
1.20 markus 246: NULL},
1.81 markus 247: {"keyboard-interactive",
248: userauth_kbdint,
249: &options.kbd_interactive_authentication,
250: &options.batch_mode},
1.20 markus 251: {"password",
252: userauth_passwd,
253: &options.password_authentication,
1.23 markus 254: &options.batch_mode},
255: {"none",
256: userauth_none,
257: NULL,
258: NULL},
1.20 markus 259: {NULL, NULL, NULL, NULL}
260: };
261:
262: void
1.68 markus 263: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 264: Sensitive *sensitive)
1.20 markus 265: {
266: Authctxt authctxt;
267: int type;
1.39 markus 268:
1.73 markus 269: if (options.challenge_response_authentication)
1.39 markus 270: options.kbd_interactive_authentication = 1;
1.20 markus 271:
272: packet_start(SSH2_MSG_SERVICE_REQUEST);
273: packet_put_cstring("ssh-userauth");
274: packet_send();
1.108 markus 275: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 276: packet_write_wait();
1.91 markus 277: type = packet_read();
1.108 markus 278: if (type != SSH2_MSG_SERVICE_ACCEPT)
279: fatal("Server denied authentication request: %d", type);
1.20 markus 280: if (packet_remaining() > 0) {
1.91 markus 281: char *reply = packet_get_string(NULL);
1.108 markus 282: debug2("service_accept: %s", reply);
1.20 markus 283: xfree(reply);
284: } else {
1.109 markus 285: debug2("buggy server: service_accept w/o service");
1.20 markus 286: }
1.90 markus 287: packet_check_eom();
1.108 markus 288: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 289:
1.53 markus 290: if (options.preferred_authentications == NULL)
291: options.preferred_authentications = authmethods_get();
292:
1.20 markus 293: /* setup authentication context */
1.82 markus 294: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 295: pubkey_prepare(&authctxt);
1.20 markus 296: authctxt.server_user = server_user;
1.68 markus 297: authctxt.local_user = local_user;
1.20 markus 298: authctxt.host = host;
299: authctxt.service = "ssh-connection"; /* service name */
300: authctxt.success = 0;
1.23 markus 301: authctxt.method = authmethod_lookup("none");
1.51 markus 302: authctxt.authlist = NULL;
1.121 markus 303: authctxt.methoddata = NULL;
1.100 markus 304: authctxt.sensitive = sensitive;
1.82 markus 305: authctxt.info_req_seen = 0;
1.23 markus 306: if (authctxt.method == NULL)
307: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 308:
309: /* initial userauth request */
1.23 markus 310: userauth_none(&authctxt);
1.20 markus 311:
1.65 markus 312: dispatch_init(&input_userauth_error);
1.20 markus 313: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
314: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 315: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 316: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
317:
1.117 markus 318: pubkey_cleanup(&authctxt);
1.119 markus 319: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
320:
1.109 markus 321: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 322: }
1.119 markus 323:
1.20 markus 324: void
1.51 markus 325: userauth(Authctxt *authctxt, char *authlist)
326: {
1.121 markus 327: if (authctxt->methoddata) {
328: xfree(authctxt->methoddata);
329: authctxt->methoddata = NULL;
330: }
1.51 markus 331: if (authlist == NULL) {
332: authlist = authctxt->authlist;
333: } else {
334: if (authctxt->authlist)
335: xfree(authctxt->authlist);
336: authctxt->authlist = authlist;
337: }
338: for (;;) {
339: Authmethod *method = authmethod_get(authlist);
340: if (method == NULL)
341: fatal("Permission denied (%s).", authlist);
342: authctxt->method = method;
1.119 markus 343:
344: /* reset the per method handler */
345: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
346: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
347:
348: /* and try new method */
1.51 markus 349: if (method->userauth(authctxt) != 0) {
350: debug2("we sent a %s packet, wait for reply", method->name);
351: break;
352: } else {
353: debug2("we did not send a packet, disable method");
354: method->enabled = NULL;
355: }
356: }
357: }
1.105 deraadt 358:
1.51 markus 359: void
1.92 markus 360: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 361: {
1.35 markus 362: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 363: "type %d", type);
1.35 markus 364: }
1.105 deraadt 365:
1.35 markus 366: void
1.92 markus 367: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 368: {
369: char *msg, *lang;
1.126 deraadt 370:
1.35 markus 371: debug3("input_userauth_banner");
372: msg = packet_get_string(NULL);
373: lang = packet_get_string(NULL);
1.125 dtucker 374: if (options.log_level > SYSLOG_LEVEL_QUIET)
375: fprintf(stderr, "%s", msg);
1.35 markus 376: xfree(msg);
377: xfree(lang);
1.20 markus 378: }
1.105 deraadt 379:
1.20 markus 380: void
1.92 markus 381: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 382: {
383: Authctxt *authctxt = ctxt;
384: if (authctxt == NULL)
385: fatal("input_userauth_success: no authentication context");
1.126 deraadt 386: if (authctxt->authlist) {
1.51 markus 387: xfree(authctxt->authlist);
1.126 deraadt 388: authctxt->authlist = NULL;
389: }
390: if (authctxt->methoddata) {
1.121 markus 391: xfree(authctxt->methoddata);
1.126 deraadt 392: authctxt->methoddata = NULL;
393: }
1.20 markus 394: authctxt->success = 1; /* break out */
395: }
1.105 deraadt 396:
1.20 markus 397: void
1.92 markus 398: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 399: {
400: Authctxt *authctxt = ctxt;
401: char *authlist = NULL;
402: int partial;
403:
404: if (authctxt == NULL)
405: fatal("input_userauth_failure: no authentication context");
406:
1.23 markus 407: authlist = packet_get_string(NULL);
1.20 markus 408: partial = packet_get_char();
1.90 markus 409: packet_check_eom();
1.20 markus 410:
411: if (partial != 0)
1.116 itojun 412: logit("Authenticated with partial success.");
1.109 markus 413: debug("Authentications that can continue: %s", authlist);
1.20 markus 414:
1.51 markus 415: userauth(authctxt, authlist);
416: }
417: void
1.92 markus 418: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 419: {
420: Authctxt *authctxt = ctxt;
421: Key *key = NULL;
1.117 markus 422: Identity *id = NULL;
1.51 markus 423: Buffer b;
1.96 markus 424: int pktype, sent = 0;
425: u_int alen, blen;
426: char *pkalg, *fp;
427: u_char *pkblob;
1.51 markus 428:
429: if (authctxt == NULL)
430: fatal("input_userauth_pk_ok: no authentication context");
431: if (datafellows & SSH_BUG_PKOK) {
432: /* this is similar to SSH_BUG_PKAUTH */
433: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
434: pkblob = packet_get_string(&blen);
435: buffer_init(&b);
436: buffer_append(&b, pkblob, blen);
437: pkalg = buffer_get_string(&b, &alen);
438: buffer_free(&b);
439: } else {
440: pkalg = packet_get_string(&alen);
441: pkblob = packet_get_string(&blen);
442: }
1.90 markus 443: packet_check_eom();
1.51 markus 444:
1.117 markus 445: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 446:
1.117 markus 447: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
448: debug("unknown pkalg %s", pkalg);
449: goto done;
450: }
451: if ((key = key_from_blob(pkblob, blen)) == NULL) {
452: debug("no key from blob. pkalg %s", pkalg);
453: goto done;
454: }
455: if (key->type != pktype) {
456: error("input_userauth_pk_ok: type mismatch "
457: "for decoded key (received %d, expected %d)",
458: key->type, pktype);
459: goto done;
460: }
461: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
462: debug2("input_userauth_pk_ok: fp %s", fp);
463: xfree(fp);
464:
1.127 markus 465: /*
466: * search keys in the reverse order, because last candidate has been
467: * moved to the end of the queue. this also avoids confusion by
468: * duplicate keys
469: */
1.136 henning 470: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 471: if (key_equal(key, id->key)) {
472: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 473: break;
474: }
1.117 markus 475: }
476: done:
1.51 markus 477: if (key != NULL)
478: key_free(key);
479: xfree(pkalg);
480: xfree(pkblob);
481:
1.106 deraadt 482: /* try another method if we did not send a packet */
1.51 markus 483: if (sent == 0)
484: userauth(authctxt, NULL);
1.20 markus 485: }
1.121 markus 486:
487: #ifdef GSSAPI
1.133 djm 488: int
1.121 markus 489: userauth_gssapi(Authctxt *authctxt)
490: {
491: Gssctxt *gssctxt = NULL;
1.128 avsm 492: static gss_OID_set gss_supported = NULL;
1.139 djm 493: static u_int mech = 0;
1.121 markus 494: OM_uint32 min;
495: int ok = 0;
496:
497: /* Try one GSSAPI method at a time, rather than sending them all at
498: * once. */
499:
1.128 avsm 500: if (gss_supported == NULL)
501: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 502:
503: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 504: while (mech < gss_supported->count && !ok) {
1.121 markus 505: if (gssctxt)
506: ssh_gssapi_delete_ctx(&gssctxt);
507: ssh_gssapi_build_ctx(&gssctxt);
1.128 avsm 508: ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]);
1.121 markus 509:
510: /* My DER encoding requires length<128 */
1.128 avsm 511: if (gss_supported->elements[mech].length < 128 &&
1.121 markus 512: !GSS_ERROR(ssh_gssapi_import_name(gssctxt,
513: authctxt->host))) {
514: ok = 1; /* Mechanism works */
515: } else {
516: mech++;
517: }
518: }
519:
1.148 djm 520: if (!ok) {
521: ssh_gssapi_delete_ctx(&gssctxt);
1.139 djm 522: return 0;
1.148 djm 523: }
1.121 markus 524:
525: authctxt->methoddata=(void *)gssctxt;
526:
527: packet_start(SSH2_MSG_USERAUTH_REQUEST);
528: packet_put_cstring(authctxt->server_user);
529: packet_put_cstring(authctxt->service);
530: packet_put_cstring(authctxt->method->name);
531:
532: packet_put_int(1);
533:
1.129 markus 534: packet_put_int((gss_supported->elements[mech].length) + 2);
535: packet_put_char(SSH_GSS_OIDTYPE);
536: packet_put_char(gss_supported->elements[mech].length);
537: packet_put_raw(gss_supported->elements[mech].elements,
538: gss_supported->elements[mech].length);
1.121 markus 539:
540: packet_send();
541:
542: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
543: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
544: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
545: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
546:
547: mech++; /* Move along to next candidate */
548:
549: return 1;
550: }
551:
1.130 markus 552: static OM_uint32
553: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
554: {
555: Authctxt *authctxt = ctxt;
556: Gssctxt *gssctxt = authctxt->methoddata;
557: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 558: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
559: gss_buffer_desc gssbuf;
1.132 markus 560: OM_uint32 status, ms, flags;
561: Buffer b;
1.133 djm 562:
1.130 markus 563: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 564: recv_tok, &send_tok, &flags);
1.130 markus 565:
566: if (send_tok.length > 0) {
567: if (GSS_ERROR(status))
568: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
569: else
570: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 571:
1.130 markus 572: packet_put_string(send_tok.value, send_tok.length);
573: packet_send();
574: gss_release_buffer(&ms, &send_tok);
575: }
1.133 djm 576:
1.130 markus 577: if (status == GSS_S_COMPLETE) {
1.132 markus 578: /* send either complete or MIC, depending on mechanism */
579: if (!(flags & GSS_C_INTEG_FLAG)) {
580: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
581: packet_send();
582: } else {
583: ssh_gssapi_buildmic(&b, authctxt->server_user,
584: authctxt->service, "gssapi-with-mic");
585:
586: gssbuf.value = buffer_ptr(&b);
587: gssbuf.length = buffer_len(&b);
1.133 djm 588:
1.132 markus 589: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 590:
1.132 markus 591: if (!GSS_ERROR(status)) {
592: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
593: packet_put_string(mic.value, mic.length);
1.133 djm 594:
1.132 markus 595: packet_send();
596: }
1.133 djm 597:
1.132 markus 598: buffer_free(&b);
599: gss_release_buffer(&ms, &mic);
1.133 djm 600: }
1.130 markus 601: }
1.133 djm 602:
1.130 markus 603: return status;
604: }
605:
1.121 markus 606: void
607: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
608: {
609: Authctxt *authctxt = ctxt;
610: Gssctxt *gssctxt;
611: int oidlen;
612: char *oidv;
613:
614: if (authctxt == NULL)
615: fatal("input_gssapi_response: no authentication context");
616: gssctxt = authctxt->methoddata;
617:
618: /* Setup our OID */
619: oidv = packet_get_string(&oidlen);
620:
1.129 markus 621: if (oidlen <= 2 ||
622: oidv[0] != SSH_GSS_OIDTYPE ||
623: oidv[1] != oidlen - 2) {
1.130 markus 624: xfree(oidv);
1.129 markus 625: debug("Badly encoded mechanism OID received");
626: userauth(authctxt, NULL);
627: return;
1.121 markus 628: }
1.129 markus 629:
630: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
631: fatal("Server returned different OID than expected");
1.121 markus 632:
633: packet_check_eom();
634:
635: xfree(oidv);
636:
1.130 markus 637: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 638: /* Start again with next method on list */
639: debug("Trying to start again");
640: userauth(authctxt, NULL);
641: return;
642: }
643: }
644:
645: void
646: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
647: {
648: Authctxt *authctxt = ctxt;
649: gss_buffer_desc recv_tok;
1.130 markus 650: OM_uint32 status;
1.121 markus 651: u_int slen;
652:
653: if (authctxt == NULL)
654: fatal("input_gssapi_response: no authentication context");
655:
656: recv_tok.value = packet_get_string(&slen);
657: recv_tok.length = slen; /* safe typecast */
658:
659: packet_check_eom();
660:
1.130 markus 661: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 662:
663: xfree(recv_tok.value);
664:
665: if (GSS_ERROR(status)) {
666: /* Start again with the next method in the list */
667: userauth(authctxt, NULL);
668: return;
669: }
670: }
671:
672: void
673: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
674: {
675: Authctxt *authctxt = ctxt;
676: Gssctxt *gssctxt;
677: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
678: gss_buffer_desc recv_tok;
679: OM_uint32 status, ms;
1.123 deraadt 680: u_int len;
1.121 markus 681:
682: if (authctxt == NULL)
683: fatal("input_gssapi_response: no authentication context");
684: gssctxt = authctxt->methoddata;
685:
1.123 deraadt 686: recv_tok.value = packet_get_string(&len);
687: recv_tok.length = len;
1.121 markus 688:
689: packet_check_eom();
690:
691: /* Stick it into GSSAPI and see what it says */
692: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 693: &recv_tok, &send_tok, NULL);
1.121 markus 694:
695: xfree(recv_tok.value);
696: gss_release_buffer(&ms, &send_tok);
697:
698: /* Server will be returning a failed packet after this one */
699: }
700:
701: void
702: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
703: {
704: OM_uint32 maj, min;
705: char *msg;
706: char *lang;
707:
708: maj=packet_get_int();
709: min=packet_get_int();
710: msg=packet_get_string(NULL);
711: lang=packet_get_string(NULL);
712:
713: packet_check_eom();
714:
1.143 stevesk 715: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 716: xfree(msg);
717: xfree(lang);
718: }
719: #endif /* GSSAPI */
1.20 markus 720:
1.1 markus 721: int
1.23 markus 722: userauth_none(Authctxt *authctxt)
723: {
724: /* initial userauth request */
725: packet_start(SSH2_MSG_USERAUTH_REQUEST);
726: packet_put_cstring(authctxt->server_user);
727: packet_put_cstring(authctxt->service);
728: packet_put_cstring(authctxt->method->name);
729: packet_send();
730: return 1;
731: }
732:
733: int
1.20 markus 734: userauth_passwd(Authctxt *authctxt)
1.1 markus 735: {
1.6 markus 736: static int attempt = 0;
1.99 markus 737: char prompt[150];
1.1 markus 738: char *password;
1.6 markus 739:
1.13 todd 740: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 741: return 0;
1.13 todd 742:
1.87 deraadt 743: if (attempt != 1)
1.13 todd 744: error("Permission denied, please try again.");
1.1 markus 745:
1.43 itojun 746: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.20 markus 747: authctxt->server_user, authctxt->host);
1.1 markus 748: password = read_passphrase(prompt, 0);
749: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 750: packet_put_cstring(authctxt->server_user);
751: packet_put_cstring(authctxt->service);
1.23 markus 752: packet_put_cstring(authctxt->method->name);
1.1 markus 753: packet_put_char(0);
1.49 markus 754: packet_put_cstring(password);
1.1 markus 755: memset(password, 0, strlen(password));
756: xfree(password);
1.85 markus 757: packet_add_padding(64);
1.1 markus 758: packet_send();
1.99 markus 759:
1.104 deraadt 760: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 761: &input_userauth_passwd_changereq);
762:
1.1 markus 763: return 1;
764: }
1.99 markus 765: /*
766: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
767: */
768: void
1.153 djm 769: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 770: {
771: Authctxt *authctxt = ctxt;
772: char *info, *lang, *password = NULL, *retype = NULL;
773: char prompt[150];
774:
775: debug2("input_userauth_passwd_changereq");
776:
777: if (authctxt == NULL)
778: fatal("input_userauth_passwd_changereq: "
779: "no authentication context");
780:
781: info = packet_get_string(NULL);
782: lang = packet_get_string(NULL);
783: if (strlen(info) > 0)
1.116 itojun 784: logit("%s", info);
1.99 markus 785: xfree(info);
786: xfree(lang);
787: packet_start(SSH2_MSG_USERAUTH_REQUEST);
788: packet_put_cstring(authctxt->server_user);
789: packet_put_cstring(authctxt->service);
790: packet_put_cstring(authctxt->method->name);
791: packet_put_char(1); /* additional info */
1.104 deraadt 792: snprintf(prompt, sizeof(prompt),
1.99 markus 793: "Enter %.30s@%.128s's old password: ",
794: authctxt->server_user, authctxt->host);
795: password = read_passphrase(prompt, 0);
796: packet_put_cstring(password);
797: memset(password, 0, strlen(password));
798: xfree(password);
799: password = NULL;
800: while (password == NULL) {
1.104 deraadt 801: snprintf(prompt, sizeof(prompt),
1.99 markus 802: "Enter %.30s@%.128s's new password: ",
803: authctxt->server_user, authctxt->host);
804: password = read_passphrase(prompt, RP_ALLOW_EOF);
805: if (password == NULL) {
806: /* bail out */
807: return;
808: }
1.104 deraadt 809: snprintf(prompt, sizeof(prompt),
1.99 markus 810: "Retype %.30s@%.128s's new password: ",
811: authctxt->server_user, authctxt->host);
812: retype = read_passphrase(prompt, 0);
813: if (strcmp(password, retype) != 0) {
814: memset(password, 0, strlen(password));
815: xfree(password);
1.116 itojun 816: logit("Mismatch; try again, EOF to quit.");
1.99 markus 817: password = NULL;
818: }
819: memset(retype, 0, strlen(retype));
820: xfree(retype);
821: }
822: packet_put_cstring(password);
823: memset(password, 0, strlen(password));
824: xfree(password);
825: packet_add_padding(64);
826: packet_send();
1.104 deraadt 827:
828: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 829: &input_userauth_passwd_changereq);
1.117 markus 830: }
831:
832: static int
833: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
834: u_char *data, u_int datalen)
835: {
836: Key *prv;
837: int ret;
1.99 markus 838:
1.117 markus 839: /* the agent supports this key */
840: if (id->ac)
841: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
842: data, datalen));
843: /*
844: * we have already loaded the private key or
845: * the private key is stored in external hardware
846: */
847: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
848: return (key_sign(id->key, sigp, lenp, data, datalen));
849: /* load the private key from the file */
850: if ((prv = load_identity_file(id->filename)) == NULL)
851: return (-1);
852: ret = key_sign(prv, sigp, lenp, data, datalen);
853: key_free(prv);
854: return (ret);
1.51 markus 855: }
856:
1.76 itojun 857: static int
1.117 markus 858: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 859: {
860: Buffer b;
1.32 markus 861: u_char *blob, *signature;
1.96 markus 862: u_int bloblen, slen;
1.120 markus 863: u_int skip = 0;
1.17 markus 864: int ret = -1;
1.23 markus 865: int have_sig = 1;
1.1 markus 866:
1.30 markus 867: debug3("sign_and_send_pubkey");
1.51 markus 868:
1.117 markus 869: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 870: /* we cannot handle this key */
1.30 markus 871: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 872: return 0;
873: }
1.1 markus 874: /* data to be signed */
875: buffer_init(&b);
1.26 markus 876: if (datafellows & SSH_OLD_SESSIONID) {
877: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 878: skip = session_id2_len;
1.26 markus 879: } else {
1.14 markus 880: buffer_put_string(&b, session_id2, session_id2_len);
881: skip = buffer_len(&b);
882: }
1.1 markus 883: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 884: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 885: buffer_put_cstring(&b,
1.30 markus 886: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 887: "ssh-userauth" :
1.20 markus 888: authctxt->service);
1.30 markus 889: if (datafellows & SSH_BUG_PKAUTH) {
890: buffer_put_char(&b, have_sig);
891: } else {
892: buffer_put_cstring(&b, authctxt->method->name);
893: buffer_put_char(&b, have_sig);
1.117 markus 894: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 895: }
1.1 markus 896: buffer_put_string(&b, blob, bloblen);
897:
898: /* generate signature */
1.117 markus 899: ret = identity_sign(id, &signature, &slen,
1.51 markus 900: buffer_ptr(&b), buffer_len(&b));
1.17 markus 901: if (ret == -1) {
902: xfree(blob);
903: buffer_free(&b);
904: return 0;
905: }
1.28 markus 906: #ifdef DEBUG_PK
1.1 markus 907: buffer_dump(&b);
908: #endif
1.30 markus 909: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 910: buffer_clear(&b);
911: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 912: skip = session_id2_len;
1.10 markus 913: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 914: buffer_put_cstring(&b, authctxt->server_user);
915: buffer_put_cstring(&b, authctxt->service);
1.23 markus 916: buffer_put_cstring(&b, authctxt->method->name);
917: buffer_put_char(&b, have_sig);
1.30 markus 918: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 919: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 920: buffer_put_string(&b, blob, bloblen);
921: }
922: xfree(blob);
1.51 markus 923:
1.1 markus 924: /* append signature */
925: buffer_put_string(&b, signature, slen);
926: xfree(signature);
927:
928: /* skip session id and packet type */
1.14 markus 929: if (buffer_len(&b) < skip + 1)
1.20 markus 930: fatal("userauth_pubkey: internal error");
1.14 markus 931: buffer_consume(&b, skip + 1);
1.1 markus 932:
933: /* put remaining data from buffer into packet */
934: packet_start(SSH2_MSG_USERAUTH_REQUEST);
935: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
936: buffer_free(&b);
937: packet_send();
1.17 markus 938:
939: return 1;
1.16 markus 940: }
941:
1.76 itojun 942: static int
1.117 markus 943: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 944: {
1.51 markus 945: u_char *blob;
1.97 markus 946: u_int bloblen, have_sig = 0;
1.20 markus 947:
1.51 markus 948: debug3("send_pubkey_test");
1.16 markus 949:
1.117 markus 950: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 951: /* we cannot handle this key */
952: debug3("send_pubkey_test: cannot handle key");
1.16 markus 953: return 0;
954: }
1.51 markus 955: /* register callback for USERAUTH_PK_OK message */
956: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
957:
958: packet_start(SSH2_MSG_USERAUTH_REQUEST);
959: packet_put_cstring(authctxt->server_user);
960: packet_put_cstring(authctxt->service);
961: packet_put_cstring(authctxt->method->name);
962: packet_put_char(have_sig);
963: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 964: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 965: packet_put_string(blob, bloblen);
966: xfree(blob);
967: packet_send();
968: return 1;
969: }
970:
1.76 itojun 971: static Key *
1.51 markus 972: load_identity_file(char *filename)
973: {
974: Key *private;
975: char prompt[300], *passphrase;
1.152 dtucker 976: int perm_ok, quit, i;
1.52 markus 977: struct stat st;
1.16 markus 978:
1.52 markus 979: if (stat(filename, &st) < 0) {
980: debug3("no such identity: %s", filename);
981: return NULL;
982: }
1.152 dtucker 983: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
984: if (!perm_ok)
985: return NULL;
1.56 markus 986: if (private == NULL) {
987: if (options.batch_mode)
1.51 markus 988: return NULL;
1.16 markus 989: snprintf(prompt, sizeof prompt,
1.88 deraadt 990: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 991: for (i = 0; i < options.number_of_password_prompts; i++) {
992: passphrase = read_passphrase(prompt, 0);
993: if (strcmp(passphrase, "") != 0) {
1.152 dtucker 994: private = key_load_private_type(KEY_UNSPEC,
995: filename, passphrase, NULL, NULL);
1.51 markus 996: quit = 0;
1.20 markus 997: } else {
998: debug2("no passphrase given, try next key");
1.51 markus 999: quit = 1;
1.20 markus 1000: }
1001: memset(passphrase, 0, strlen(passphrase));
1002: xfree(passphrase);
1.56 markus 1003: if (private != NULL || quit)
1.20 markus 1004: break;
1005: debug2("bad passphrase given, try again...");
1.16 markus 1006: }
1007: }
1.51 markus 1008: return private;
1009: }
1010:
1.117 markus 1011: /*
1012: * try keys in the following order:
1013: * 1. agent keys that are found in the config file
1014: * 2. other agent keys
1015: * 3. keys that are only listed in the config file
1016: */
1017: static void
1018: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1019: {
1.117 markus 1020: Identity *id;
1021: Idlist agent, files, *preferred;
1022: Key *key;
1023: AuthenticationConnection *ac;
1024: char *comment;
1025: int i, found;
1.51 markus 1026:
1.117 markus 1027: TAILQ_INIT(&agent); /* keys from the agent */
1028: TAILQ_INIT(&files); /* keys from the config file */
1029: preferred = &authctxt->keys;
1030: TAILQ_INIT(preferred); /* preferred order of keys */
1031:
1032: /* list of keys stored in the filesystem */
1033: for (i = 0; i < options.num_identity_files; i++) {
1034: key = options.identity_keys[i];
1035: if (key && key->type == KEY_RSA1)
1036: continue;
1037: options.identity_keys[i] = NULL;
1.150 djm 1038: id = xcalloc(1, sizeof(*id));
1.117 markus 1039: id->key = key;
1040: id->filename = xstrdup(options.identity_files[i]);
1041: TAILQ_INSERT_TAIL(&files, id, next);
1042: }
1043: /* list of keys supported by the agent */
1044: if ((ac = ssh_get_authentication_connection())) {
1045: for (key = ssh_get_first_identity(ac, &comment, 2);
1046: key != NULL;
1047: key = ssh_get_next_identity(ac, &comment, 2)) {
1048: found = 0;
1049: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1050: /* agent keys from the config file are preferred */
1.117 markus 1051: if (key_equal(key, id->key)) {
1052: key_free(key);
1053: xfree(comment);
1054: TAILQ_REMOVE(&files, id, next);
1055: TAILQ_INSERT_TAIL(preferred, id, next);
1056: id->ac = ac;
1057: found = 1;
1058: break;
1059: }
1060: }
1.135 markus 1061: if (!found && !options.identities_only) {
1.150 djm 1062: id = xcalloc(1, sizeof(*id));
1.117 markus 1063: id->key = key;
1064: id->filename = comment;
1065: id->ac = ac;
1066: TAILQ_INSERT_TAIL(&agent, id, next);
1067: }
1068: }
1069: /* append remaining agent keys */
1070: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1071: TAILQ_REMOVE(&agent, id, next);
1072: TAILQ_INSERT_TAIL(preferred, id, next);
1073: }
1074: authctxt->agent = ac;
1075: }
1076: /* append remaining keys from the config file */
1077: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1078: TAILQ_REMOVE(&files, id, next);
1079: TAILQ_INSERT_TAIL(preferred, id, next);
1080: }
1081: TAILQ_FOREACH(id, preferred, next) {
1082: debug2("key: %s (%p)", id->filename, id->key);
1083: }
1.17 markus 1084: }
1085:
1.117 markus 1086: static void
1087: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1088: {
1.117 markus 1089: Identity *id;
1.51 markus 1090:
1.117 markus 1091: if (authctxt->agent != NULL)
1092: ssh_close_authentication_connection(authctxt->agent);
1093: for (id = TAILQ_FIRST(&authctxt->keys); id;
1094: id = TAILQ_FIRST(&authctxt->keys)) {
1095: TAILQ_REMOVE(&authctxt->keys, id, next);
1096: if (id->key)
1097: key_free(id->key);
1098: if (id->filename)
1099: xfree(id->filename);
1100: xfree(id);
1101: }
1.1 markus 1102: }
1103:
1.20 markus 1104: int
1105: userauth_pubkey(Authctxt *authctxt)
1106: {
1.117 markus 1107: Identity *id;
1.20 markus 1108: int sent = 0;
1109:
1.117 markus 1110: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1111: if (id->tried++)
1112: return (0);
1.127 markus 1113: /* move key to the end of the queue */
1.117 markus 1114: TAILQ_REMOVE(&authctxt->keys, id, next);
1115: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1116: /*
1117: * send a test message if we have the public key. for
1118: * encrypted keys we cannot do this and have to load the
1119: * private key instead
1120: */
1121: if (id->key && id->key->type != KEY_RSA1) {
1122: debug("Offering public key: %s", id->filename);
1123: sent = send_pubkey_test(authctxt, id);
1124: } else if (id->key == NULL) {
1125: debug("Trying private key: %s", id->filename);
1126: id->key = load_identity_file(id->filename);
1127: if (id->key != NULL) {
1128: id->isprivate = 1;
1129: sent = sign_and_send_pubkey(authctxt, id);
1130: key_free(id->key);
1131: id->key = NULL;
1.51 markus 1132: }
1133: }
1.117 markus 1134: if (sent)
1135: return (sent);
1.28 markus 1136: }
1.117 markus 1137: return (0);
1.20 markus 1138: }
1139:
1.23 markus 1140: /*
1141: * Send userauth request message specifying keyboard-interactive method.
1142: */
1143: int
1144: userauth_kbdint(Authctxt *authctxt)
1145: {
1146: static int attempt = 0;
1147:
1148: if (attempt++ >= options.number_of_password_prompts)
1149: return 0;
1.82 markus 1150: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1151: if (attempt > 1 && !authctxt->info_req_seen) {
1152: debug3("userauth_kbdint: disable: no info_req_seen");
1153: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1154: return 0;
1155: }
1.23 markus 1156:
1157: debug2("userauth_kbdint");
1158: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1159: packet_put_cstring(authctxt->server_user);
1160: packet_put_cstring(authctxt->service);
1161: packet_put_cstring(authctxt->method->name);
1162: packet_put_cstring(""); /* lang */
1163: packet_put_cstring(options.kbd_interactive_devices ?
1164: options.kbd_interactive_devices : "");
1165: packet_send();
1166:
1167: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1168: return 1;
1169: }
1170:
1171: /*
1.46 markus 1172: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1173: */
1174: void
1.92 markus 1175: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1176: {
1177: Authctxt *authctxt = ctxt;
1.46 markus 1178: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1179: u_int num_prompts, i;
1.23 markus 1180: int echo = 0;
1181:
1182: debug2("input_userauth_info_req");
1183:
1184: if (authctxt == NULL)
1185: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1186:
1187: authctxt->info_req_seen = 1;
1.23 markus 1188:
1189: name = packet_get_string(NULL);
1190: inst = packet_get_string(NULL);
1191: lang = packet_get_string(NULL);
1192: if (strlen(name) > 0)
1.116 itojun 1193: logit("%s", name);
1.23 markus 1194: if (strlen(inst) > 0)
1.116 itojun 1195: logit("%s", inst);
1.46 markus 1196: xfree(name);
1.23 markus 1197: xfree(inst);
1.46 markus 1198: xfree(lang);
1.23 markus 1199:
1200: num_prompts = packet_get_int();
1201: /*
1202: * Begin to build info response packet based on prompts requested.
1203: * We commit to providing the correct number of responses, so if
1204: * further on we run into a problem that prevents this, we have to
1205: * be sure and clean this up and send a correct error response.
1206: */
1207: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1208: packet_put_int(num_prompts);
1209:
1.73 markus 1210: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1211: for (i = 0; i < num_prompts; i++) {
1212: prompt = packet_get_string(NULL);
1213: echo = packet_get_char();
1214:
1.77 markus 1215: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1216:
1.49 markus 1217: packet_put_cstring(response);
1.23 markus 1218: memset(response, 0, strlen(response));
1219: xfree(response);
1220: xfree(prompt);
1221: }
1.90 markus 1222: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1223:
1.85 markus 1224: packet_add_padding(64);
1.23 markus 1225: packet_send();
1.68 markus 1226: }
1227:
1.100 markus 1228: static int
1.105 deraadt 1229: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1230: u_char *data, u_int datalen)
1231: {
1232: Buffer b;
1.101 markus 1233: struct stat st;
1.100 markus 1234: pid_t pid;
1.103 markus 1235: int to[2], from[2], status, version = 2;
1.100 markus 1236:
1.109 markus 1237: debug2("ssh_keysign called");
1.100 markus 1238:
1.101 markus 1239: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1240: error("ssh_keysign: no installed: %s", strerror(errno));
1241: return -1;
1242: }
1.100 markus 1243: if (fflush(stdout) != 0)
1244: error("ssh_keysign: fflush: %s", strerror(errno));
1245: if (pipe(to) < 0) {
1246: error("ssh_keysign: pipe: %s", strerror(errno));
1247: return -1;
1248: }
1249: if (pipe(from) < 0) {
1250: error("ssh_keysign: pipe: %s", strerror(errno));
1251: return -1;
1252: }
1253: if ((pid = fork()) < 0) {
1254: error("ssh_keysign: fork: %s", strerror(errno));
1255: return -1;
1256: }
1257: if (pid == 0) {
1.155 markus 1258: permanently_drop_suid(getuid());
1.100 markus 1259: close(from[0]);
1260: if (dup2(from[1], STDOUT_FILENO) < 0)
1261: fatal("ssh_keysign: dup2: %s", strerror(errno));
1262: close(to[1]);
1263: if (dup2(to[0], STDIN_FILENO) < 0)
1264: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1265: close(from[1]);
1266: close(to[0]);
1.102 markus 1267: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1268: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1269: strerror(errno));
1270: }
1271: close(from[1]);
1272: close(to[0]);
1273:
1274: buffer_init(&b);
1.103 markus 1275: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1276: buffer_put_string(&b, data, datalen);
1.131 djm 1277: if (ssh_msg_send(to[1], version, &b) == -1)
1278: fatal("ssh_keysign: couldn't send request");
1.100 markus 1279:
1.110 djm 1280: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1281: error("ssh_keysign: no reply");
1.134 markus 1282: buffer_free(&b);
1.100 markus 1283: return -1;
1284: }
1.101 markus 1285: close(from[0]);
1286: close(to[1]);
1287:
1.103 markus 1288: while (waitpid(pid, &status, 0) < 0)
1289: if (errno != EINTR)
1290: break;
1.101 markus 1291:
1.100 markus 1292: if (buffer_get_char(&b) != version) {
1.101 markus 1293: error("ssh_keysign: bad version");
1.134 markus 1294: buffer_free(&b);
1.100 markus 1295: return -1;
1296: }
1297: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1298: buffer_free(&b);
1.100 markus 1299:
1300: return 0;
1301: }
1302:
1.68 markus 1303: int
1304: userauth_hostbased(Authctxt *authctxt)
1305: {
1306: Key *private = NULL;
1.100 markus 1307: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1308: Buffer b;
1309: u_char *signature, *blob;
1310: char *chost, *pkalg, *p;
1.72 markus 1311: const char *service;
1.68 markus 1312: u_int blen, slen;
1.71 markus 1313: int ok, i, len, found = 0;
1.68 markus 1314:
1315: /* check for a useful key */
1.100 markus 1316: for (i = 0; i < sensitive->nkeys; i++) {
1317: private = sensitive->keys[i];
1.68 markus 1318: if (private && private->type != KEY_RSA1) {
1319: found = 1;
1320: /* we take and free the key */
1.100 markus 1321: sensitive->keys[i] = NULL;
1.68 markus 1322: break;
1323: }
1324: }
1325: if (!found) {
1.109 markus 1326: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1327: return 0;
1328: }
1329: if (key_to_blob(private, &blob, &blen) == 0) {
1330: key_free(private);
1331: return 0;
1332: }
1.84 markus 1333: /* figure out a name for the client host */
1334: p = get_local_name(packet_get_connection_in());
1335: if (p == NULL) {
1336: error("userauth_hostbased: cannot get local ipaddr/name");
1337: key_free(private);
1.148 djm 1338: xfree(blob);
1.84 markus 1339: return 0;
1340: }
1341: len = strlen(p) + 2;
1.150 djm 1342: xasprintf(&chost, "%s.", p);
1.84 markus 1343: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1344: xfree(p);
1.84 markus 1345:
1.72 markus 1346: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1347: authctxt->service;
1.68 markus 1348: pkalg = xstrdup(key_ssh_name(private));
1349: buffer_init(&b);
1350: /* construct data */
1.72 markus 1351: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1352: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1353: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1354: buffer_put_cstring(&b, service);
1.68 markus 1355: buffer_put_cstring(&b, authctxt->method->name);
1356: buffer_put_cstring(&b, pkalg);
1357: buffer_put_string(&b, blob, blen);
1358: buffer_put_cstring(&b, chost);
1359: buffer_put_cstring(&b, authctxt->local_user);
1360: #ifdef DEBUG_PK
1361: buffer_dump(&b);
1362: #endif
1.100 markus 1363: if (sensitive->external_keysign)
1364: ok = ssh_keysign(private, &signature, &slen,
1365: buffer_ptr(&b), buffer_len(&b));
1366: else
1367: ok = key_sign(private, &signature, &slen,
1368: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1369: key_free(private);
1370: buffer_free(&b);
1371: if (ok != 0) {
1372: error("key_sign failed");
1373: xfree(chost);
1374: xfree(pkalg);
1.148 djm 1375: xfree(blob);
1.68 markus 1376: return 0;
1377: }
1378: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1379: packet_put_cstring(authctxt->server_user);
1380: packet_put_cstring(authctxt->service);
1381: packet_put_cstring(authctxt->method->name);
1382: packet_put_cstring(pkalg);
1383: packet_put_string(blob, blen);
1384: packet_put_cstring(chost);
1385: packet_put_cstring(authctxt->local_user);
1386: packet_put_string(signature, slen);
1387: memset(signature, 's', slen);
1388: xfree(signature);
1389: xfree(chost);
1390: xfree(pkalg);
1.148 djm 1391: xfree(blob);
1.68 markus 1392:
1393: packet_send();
1394: return 1;
1.23 markus 1395: }
1.20 markus 1396:
1397: /* find auth method */
1398:
1399: /*
1400: * given auth method name, if configurable options permit this method fill
1401: * in auth_ident field and return true, otherwise return false.
1402: */
1.76 itojun 1403: static int
1.20 markus 1404: authmethod_is_enabled(Authmethod *method)
1405: {
1406: if (method == NULL)
1407: return 0;
1408: /* return false if options indicate this method is disabled */
1409: if (method->enabled == NULL || *method->enabled == 0)
1410: return 0;
1411: /* return false if batch mode is enabled but method needs interactive mode */
1412: if (method->batch_flag != NULL && *method->batch_flag != 0)
1413: return 0;
1414: return 1;
1415: }
1416:
1.76 itojun 1417: static Authmethod *
1.20 markus 1418: authmethod_lookup(const char *name)
1.1 markus 1419: {
1.20 markus 1420: Authmethod *method = NULL;
1421: if (name != NULL)
1422: for (method = authmethods; method->name != NULL; method++)
1423: if (strcmp(name, method->name) == 0)
1424: return method;
1425: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1426: return NULL;
1427: }
1.1 markus 1428:
1.53 markus 1429: /* XXX internal state */
1430: static Authmethod *current = NULL;
1431: static char *supported = NULL;
1432: static char *preferred = NULL;
1.105 deraadt 1433:
1.20 markus 1434: /*
1435: * Given the authentication method list sent by the server, return the
1436: * next method we should try. If the server initially sends a nil list,
1.67 markus 1437: * use a built-in default list.
1.41 stevesk 1438: */
1.76 itojun 1439: static Authmethod *
1.20 markus 1440: authmethod_get(char *authlist)
1441: {
1.53 markus 1442: char *name = NULL;
1.97 markus 1443: u_int next;
1.41 stevesk 1444:
1.20 markus 1445: /* Use a suitable default if we're passed a nil list. */
1446: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1447: authlist = options.preferred_authentications;
1.20 markus 1448:
1.53 markus 1449: if (supported == NULL || strcmp(authlist, supported) != 0) {
1450: debug3("start over, passed a different list %s", authlist);
1451: if (supported != NULL)
1452: xfree(supported);
1453: supported = xstrdup(authlist);
1454: preferred = options.preferred_authentications;
1455: debug3("preferred %s", preferred);
1456: current = NULL;
1457: } else if (current != NULL && authmethod_is_enabled(current))
1458: return current;
1.20 markus 1459:
1.53 markus 1460: for (;;) {
1461: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1462: debug("No more authentication methods to try.");
1.53 markus 1463: current = NULL;
1464: return NULL;
1465: }
1466: preferred += next;
1.23 markus 1467: debug3("authmethod_lookup %s", name);
1.53 markus 1468: debug3("remaining preferred: %s", preferred);
1469: if ((current = authmethod_lookup(name)) != NULL &&
1470: authmethod_is_enabled(current)) {
1.23 markus 1471: debug3("authmethod_is_enabled %s", name);
1.109 markus 1472: debug("Next authentication method: %s", name);
1.53 markus 1473: return current;
1.23 markus 1474: }
1.1 markus 1475: }
1.53 markus 1476: }
1.1 markus 1477:
1.79 stevesk 1478: static char *
1.53 markus 1479: authmethods_get(void)
1480: {
1481: Authmethod *method = NULL;
1.93 markus 1482: Buffer b;
1483: char *list;
1.27 provos 1484:
1.93 markus 1485: buffer_init(&b);
1.53 markus 1486: for (method = authmethods; method->name != NULL; method++) {
1487: if (authmethod_is_enabled(method)) {
1.93 markus 1488: if (buffer_len(&b) > 0)
1489: buffer_append(&b, ",", 1);
1490: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1491: }
1492: }
1.93 markus 1493: buffer_append(&b, "\0", 1);
1494: list = xstrdup(buffer_ptr(&b));
1495: buffer_free(&b);
1496: return list;
1.1 markus 1497: }
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