Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.199
1.199 ! markus 1: /* $OpenBSD: sshconnect2.c,v 1.198 2013/06/05 12:52:38 dtucker Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
1.170 djm 4: * Copyright (c) 2008 Damien Miller. All rights reserved.
1.1 markus 5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.145 stevesk 27: #include <sys/types.h>
1.160 deraadt 28: #include <sys/socket.h>
1.145 stevesk 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>
1.174 dtucker 34: #include <fcntl.h>
1.164 jolan 35: #include <netdb.h>
1.159 stevesk 36: #include <stdio.h>
1.158 stevesk 37: #include <string.h>
1.160 deraadt 38: #include <signal.h>
39: #include <pwd.h>
1.157 stevesk 40: #include <unistd.h>
1.166 djm 41: #include <vis.h>
1.1 markus 42:
1.160 deraadt 43: #include "xmalloc.h"
1.1 markus 44: #include "ssh.h"
1.37 markus 45: #include "ssh2.h"
1.1 markus 46: #include "buffer.h"
47: #include "packet.h"
48: #include "compat.h"
1.37 markus 49: #include "cipher.h"
1.160 deraadt 50: #include "key.h"
1.1 markus 51: #include "kex.h"
52: #include "myproposal.h"
53: #include "sshconnect.h"
54: #include "authfile.h"
1.57 provos 55: #include "dh.h"
1.17 markus 56: #include "authfd.h"
1.37 markus 57: #include "log.h"
58: #include "readconf.h"
1.137 djm 59: #include "misc.h"
1.53 markus 60: #include "match.h"
1.61 markus 61: #include "dispatch.h"
1.68 markus 62: #include "canohost.h"
1.100 markus 63: #include "msg.h"
64: #include "pathnames.h"
1.154 markus 65: #include "uidswap.h"
1.186 djm 66: #include "hostfile.h"
1.171 djm 67: #include "schnorr.h"
1.170 djm 68: #include "jpake.h"
1.22 provos 69:
1.121 markus 70: #ifdef GSSAPI
71: #include "ssh-gss.h"
72: #endif
73:
1.1 markus 74: /* import */
75: extern char *client_version_string;
76: extern char *server_version_string;
77: extern Options options;
78:
79: /*
80: * SSH2 key exchange
81: */
82:
1.32 markus 83: u_char *session_id2 = NULL;
1.120 markus 84: u_int session_id2_len = 0;
1.1 markus 85:
1.61 markus 86: char *xxx_host;
87: struct sockaddr *xxx_hostaddr;
88:
1.63 markus 89: Kex *xxx_kex = NULL;
90:
1.76 itojun 91: static int
1.75 markus 92: verify_host_key_callback(Key *hostkey)
1.61 markus 93: {
1.75 markus 94: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 95: fatal("Host key verification failed.");
1.61 markus 96: return 0;
97: }
98:
1.186 djm 99: static char *
100: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
101: {
102: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
103: size_t maxlen;
104: struct hostkeys *hostkeys;
105: int ktype;
1.188 djm 106: u_int i;
1.186 djm 107:
108: /* Find all hostkeys for this hostname */
109: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
110: hostkeys = init_hostkeys();
1.188 djm 111: for (i = 0; i < options.num_user_hostfiles; i++)
112: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
113: for (i = 0; i < options.num_system_hostfiles; i++)
114: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 115:
116: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
117: maxlen = strlen(avail) + 1;
118: first = xmalloc(maxlen);
119: last = xmalloc(maxlen);
120: *first = *last = '\0';
121:
122: #define ALG_APPEND(to, from) \
123: do { \
124: if (*to != '\0') \
125: strlcat(to, ",", maxlen); \
126: strlcat(to, from, maxlen); \
127: } while (0)
128:
129: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
130: if ((ktype = key_type_from_name(alg)) == KEY_UNSPEC)
131: fatal("%s: unknown alg %s", __func__, alg);
132: if (lookup_key_in_hostkeys_by_type(hostkeys,
133: key_type_plain(ktype), NULL))
134: ALG_APPEND(first, alg);
135: else
136: ALG_APPEND(last, alg);
137: }
138: #undef ALG_APPEND
139: xasprintf(&ret, "%s%s%s", first, *first == '\0' ? "" : ",", last);
140: if (*first != '\0')
141: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
142:
1.197 djm 143: free(first);
144: free(last);
145: free(hostname);
146: free(oavail);
1.186 djm 147: free_hostkeys(hostkeys);
148:
149: return ret;
150: }
151:
1.1 markus 152: void
1.186 djm 153: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 154: {
155: Kex *kex;
1.61 markus 156:
157: xxx_host = host;
158: xxx_hostaddr = hostaddr;
1.22 provos 159:
1.29 markus 160: if (options.ciphers == (char *)-1) {
1.116 itojun 161: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 162: options.ciphers = NULL;
1.24 markus 163: }
1.22 provos 164: if (options.ciphers != NULL) {
165: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
166: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
167: }
1.60 stevesk 168: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
169: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
170: myproposal[PROPOSAL_ENC_ALGS_STOC] =
171: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 172: if (options.compression) {
1.47 markus 173: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 174: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 175: } else {
1.47 markus 176: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 177: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 178: }
179: if (options.macs != NULL) {
180: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
181: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 182: }
1.70 markus 183: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 184: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.70 markus 185: options.hostkeyalgorithms;
1.186 djm 186: else {
187: /* Prefer algorithms that we already have keys for */
188: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
189: order_hostkeyalgs(host, hostaddr, port);
190: }
1.185 djm 191: if (options.kex_algorithms != NULL)
192: myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
1.115 markus 193:
1.196 dtucker 194: if (options.rekey_limit || options.rekey_interval)
195: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
196: (time_t)options.rekey_interval);
1.22 provos 197:
1.65 markus 198: /* start key exchange */
1.64 markus 199: kex = kex_setup(myproposal);
1.111 markus 200: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 201: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 202: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 203: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 204: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.199 ! markus 205: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 206: kex->client_version_string=client_version_string;
207: kex->server_version_string=server_version_string;
1.75 markus 208: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 209:
210: xxx_kex = kex;
1.22 provos 211:
1.66 markus 212: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.173 andreas 213:
214: if (options.use_roaming && !kex->roaming) {
215: debug("Roaming not allowed by server");
216: options.use_roaming = 0;
217: }
1.62 markus 218:
219: session_id2 = kex->session_id;
220: session_id2_len = kex->session_id_len;
1.22 provos 221:
222: #ifdef DEBUG_KEXDH
223: /* send 1st encrypted/maced/compressed message */
224: packet_start(SSH2_MSG_IGNORE);
225: packet_put_cstring("markus");
226: packet_send();
227: packet_write_wait();
228: #endif
1.1 markus 229: }
1.11 markus 230:
1.1 markus 231: /*
232: * Authenticate user
233: */
1.20 markus 234:
235: typedef struct Authctxt Authctxt;
236: typedef struct Authmethod Authmethod;
1.117 markus 237: typedef struct identity Identity;
238: typedef struct idlist Idlist;
1.20 markus 239:
1.117 markus 240: struct identity {
241: TAILQ_ENTRY(identity) next;
242: AuthenticationConnection *ac; /* set if agent supports key */
243: Key *key; /* public/private key */
244: char *filename; /* comment for agent-only keys */
245: int tried;
246: int isprivate; /* key points to the private key */
1.191 dtucker 247: int userprovided;
1.117 markus 248: };
249: TAILQ_HEAD(idlist, identity);
1.20 markus 250:
251: struct Authctxt {
252: const char *server_user;
1.68 markus 253: const char *local_user;
1.20 markus 254: const char *host;
255: const char *service;
1.23 markus 256: Authmethod *method;
1.183 djm 257: sig_atomic_t success;
1.51 markus 258: char *authlist;
1.68 markus 259: /* pubkey */
1.117 markus 260: Idlist keys;
1.68 markus 261: AuthenticationConnection *agent;
262: /* hostbased */
1.100 markus 263: Sensitive *sensitive;
1.82 markus 264: /* kbd-interactive */
265: int info_req_seen;
1.121 markus 266: /* generic */
267: void *methoddata;
1.20 markus 268: };
269: struct Authmethod {
270: char *name; /* string to compare against server's list */
271: int (*userauth)(Authctxt *authctxt);
1.170 djm 272: void (*cleanup)(Authctxt *authctxt);
1.20 markus 273: int *enabled; /* flag in option struct that enables method */
274: int *batch_flag; /* flag in option struct that disables method */
275: };
276:
1.92 markus 277: void input_userauth_success(int, u_int32_t, void *);
1.172 djm 278: void input_userauth_success_unexpected(int, u_int32_t, void *);
1.92 markus 279: void input_userauth_failure(int, u_int32_t, void *);
280: void input_userauth_banner(int, u_int32_t, void *);
281: void input_userauth_error(int, u_int32_t, void *);
282: void input_userauth_info_req(int, u_int32_t, void *);
283: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 284: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.170 djm 285: void input_userauth_jpake_server_step1(int, u_int32_t, void *);
286: void input_userauth_jpake_server_step2(int, u_int32_t, void *);
287: void input_userauth_jpake_server_confirm(int, u_int32_t, void *);
1.86 itojun 288:
289: int userauth_none(Authctxt *);
290: int userauth_pubkey(Authctxt *);
291: int userauth_passwd(Authctxt *);
292: int userauth_kbdint(Authctxt *);
293: int userauth_hostbased(Authctxt *);
1.170 djm 294: int userauth_jpake(Authctxt *);
295:
296: void userauth_jpake_cleanup(Authctxt *);
1.20 markus 297:
1.121 markus 298: #ifdef GSSAPI
299: int userauth_gssapi(Authctxt *authctxt);
300: void input_gssapi_response(int type, u_int32_t, void *);
301: void input_gssapi_token(int type, u_int32_t, void *);
302: void input_gssapi_hash(int type, u_int32_t, void *);
303: void input_gssapi_error(int, u_int32_t, void *);
304: void input_gssapi_errtok(int, u_int32_t, void *);
305: #endif
306:
1.86 itojun 307: void userauth(Authctxt *, char *);
1.51 markus 308:
1.117 markus 309: static int sign_and_send_pubkey(Authctxt *, Identity *);
310: static void pubkey_prepare(Authctxt *);
311: static void pubkey_cleanup(Authctxt *);
1.191 dtucker 312: static Key *load_identity_file(char *, int);
1.76 itojun 313:
314: static Authmethod *authmethod_get(char *authlist);
315: static Authmethod *authmethod_lookup(const char *name);
316: static char *authmethods_get(void);
1.20 markus 317:
318: Authmethod authmethods[] = {
1.121 markus 319: #ifdef GSSAPI
1.132 markus 320: {"gssapi-with-mic",
1.121 markus 321: userauth_gssapi,
1.170 djm 322: NULL,
1.121 markus 323: &options.gss_authentication,
324: NULL},
325: #endif
1.81 markus 326: {"hostbased",
327: userauth_hostbased,
1.170 djm 328: NULL,
1.81 markus 329: &options.hostbased_authentication,
330: NULL},
1.20 markus 331: {"publickey",
332: userauth_pubkey,
1.170 djm 333: NULL,
1.28 markus 334: &options.pubkey_authentication,
1.20 markus 335: NULL},
1.170 djm 336: #ifdef JPAKE
337: {"jpake-01@openssh.com",
338: userauth_jpake,
339: userauth_jpake_cleanup,
340: &options.zero_knowledge_password_authentication,
341: &options.batch_mode},
342: #endif
1.81 markus 343: {"keyboard-interactive",
344: userauth_kbdint,
1.170 djm 345: NULL,
1.81 markus 346: &options.kbd_interactive_authentication,
347: &options.batch_mode},
1.20 markus 348: {"password",
349: userauth_passwd,
1.170 djm 350: NULL,
1.20 markus 351: &options.password_authentication,
1.23 markus 352: &options.batch_mode},
353: {"none",
354: userauth_none,
355: NULL,
1.170 djm 356: NULL,
1.23 markus 357: NULL},
1.170 djm 358: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 359: };
360:
361: void
1.68 markus 362: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 363: Sensitive *sensitive)
1.20 markus 364: {
365: Authctxt authctxt;
366: int type;
1.39 markus 367:
1.73 markus 368: if (options.challenge_response_authentication)
1.39 markus 369: options.kbd_interactive_authentication = 1;
1.20 markus 370:
371: packet_start(SSH2_MSG_SERVICE_REQUEST);
372: packet_put_cstring("ssh-userauth");
373: packet_send();
1.108 markus 374: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 375: packet_write_wait();
1.91 markus 376: type = packet_read();
1.108 markus 377: if (type != SSH2_MSG_SERVICE_ACCEPT)
378: fatal("Server denied authentication request: %d", type);
1.20 markus 379: if (packet_remaining() > 0) {
1.91 markus 380: char *reply = packet_get_string(NULL);
1.108 markus 381: debug2("service_accept: %s", reply);
1.197 djm 382: free(reply);
1.20 markus 383: } else {
1.109 markus 384: debug2("buggy server: service_accept w/o service");
1.20 markus 385: }
1.90 markus 386: packet_check_eom();
1.108 markus 387: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 388:
1.53 markus 389: if (options.preferred_authentications == NULL)
390: options.preferred_authentications = authmethods_get();
391:
1.20 markus 392: /* setup authentication context */
1.82 markus 393: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 394: pubkey_prepare(&authctxt);
1.20 markus 395: authctxt.server_user = server_user;
1.68 markus 396: authctxt.local_user = local_user;
1.20 markus 397: authctxt.host = host;
398: authctxt.service = "ssh-connection"; /* service name */
399: authctxt.success = 0;
1.23 markus 400: authctxt.method = authmethod_lookup("none");
1.51 markus 401: authctxt.authlist = NULL;
1.121 markus 402: authctxt.methoddata = NULL;
1.100 markus 403: authctxt.sensitive = sensitive;
1.82 markus 404: authctxt.info_req_seen = 0;
1.23 markus 405: if (authctxt.method == NULL)
406: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 407:
408: /* initial userauth request */
1.23 markus 409: userauth_none(&authctxt);
1.20 markus 410:
1.65 markus 411: dispatch_init(&input_userauth_error);
1.20 markus 412: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
413: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 414: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 415: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
416:
1.117 markus 417: pubkey_cleanup(&authctxt);
1.119 markus 418: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
419:
1.109 markus 420: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 421: }
1.119 markus 422:
1.20 markus 423: void
1.51 markus 424: userauth(Authctxt *authctxt, char *authlist)
425: {
1.170 djm 426: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
427: authctxt->method->cleanup(authctxt);
428:
1.197 djm 429: free(authctxt->methoddata);
430: authctxt->methoddata = NULL;
1.51 markus 431: if (authlist == NULL) {
432: authlist = authctxt->authlist;
433: } else {
1.197 djm 434: free(authctxt->authlist);
1.51 markus 435: authctxt->authlist = authlist;
436: }
437: for (;;) {
438: Authmethod *method = authmethod_get(authlist);
439: if (method == NULL)
440: fatal("Permission denied (%s).", authlist);
441: authctxt->method = method;
1.119 markus 442:
443: /* reset the per method handler */
444: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
445: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
446:
447: /* and try new method */
1.51 markus 448: if (method->userauth(authctxt) != 0) {
449: debug2("we sent a %s packet, wait for reply", method->name);
450: break;
451: } else {
452: debug2("we did not send a packet, disable method");
453: method->enabled = NULL;
454: }
455: }
456: }
1.105 deraadt 457:
1.169 djm 458: /* ARGSUSED */
1.51 markus 459: void
1.92 markus 460: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 461: {
1.35 markus 462: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 463: "type %d", type);
1.35 markus 464: }
1.105 deraadt 465:
1.169 djm 466: /* ARGSUSED */
1.35 markus 467: void
1.92 markus 468: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 469: {
1.166 djm 470: char *msg, *raw, *lang;
471: u_int len;
1.126 deraadt 472:
1.35 markus 473: debug3("input_userauth_banner");
1.166 djm 474: raw = packet_get_string(&len);
1.35 markus 475: lang = packet_get_string(NULL);
1.167 markus 476: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 477: if (len > 65536)
478: len = 65536;
1.168 deraadt 479: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 480: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 481: fprintf(stderr, "%s", msg);
1.197 djm 482: free(msg);
1.166 djm 483: }
1.197 djm 484: free(raw);
485: free(lang);
1.20 markus 486: }
1.105 deraadt 487:
1.169 djm 488: /* ARGSUSED */
1.20 markus 489: void
1.92 markus 490: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 491: {
492: Authctxt *authctxt = ctxt;
1.172 djm 493:
1.20 markus 494: if (authctxt == NULL)
495: fatal("input_userauth_success: no authentication context");
1.197 djm 496: free(authctxt->authlist);
497: authctxt->authlist = NULL;
1.172 djm 498: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
499: authctxt->method->cleanup(authctxt);
1.197 djm 500: free(authctxt->methoddata);
501: authctxt->methoddata = NULL;
1.20 markus 502: authctxt->success = 1; /* break out */
503: }
1.105 deraadt 504:
1.172 djm 505: void
506: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
507: {
508: Authctxt *authctxt = ctxt;
509:
510: if (authctxt == NULL)
511: fatal("%s: no authentication context", __func__);
512:
513: fatal("Unexpected authentication success during %s.",
514: authctxt->method->name);
515: }
516:
1.169 djm 517: /* ARGSUSED */
1.20 markus 518: void
1.92 markus 519: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 520: {
521: Authctxt *authctxt = ctxt;
522: char *authlist = NULL;
523: int partial;
524:
525: if (authctxt == NULL)
526: fatal("input_userauth_failure: no authentication context");
527:
1.23 markus 528: authlist = packet_get_string(NULL);
1.20 markus 529: partial = packet_get_char();
1.90 markus 530: packet_check_eom();
1.20 markus 531:
1.193 markus 532: if (partial != 0) {
1.116 itojun 533: logit("Authenticated with partial success.");
1.193 markus 534: /* reset state */
535: pubkey_cleanup(authctxt);
536: pubkey_prepare(authctxt);
537: }
1.109 markus 538: debug("Authentications that can continue: %s", authlist);
1.20 markus 539:
1.51 markus 540: userauth(authctxt, authlist);
541: }
1.169 djm 542:
543: /* ARGSUSED */
1.51 markus 544: void
1.92 markus 545: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 546: {
547: Authctxt *authctxt = ctxt;
548: Key *key = NULL;
1.117 markus 549: Identity *id = NULL;
1.51 markus 550: Buffer b;
1.96 markus 551: int pktype, sent = 0;
552: u_int alen, blen;
553: char *pkalg, *fp;
554: u_char *pkblob;
1.51 markus 555:
556: if (authctxt == NULL)
557: fatal("input_userauth_pk_ok: no authentication context");
558: if (datafellows & SSH_BUG_PKOK) {
559: /* this is similar to SSH_BUG_PKAUTH */
560: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
561: pkblob = packet_get_string(&blen);
562: buffer_init(&b);
563: buffer_append(&b, pkblob, blen);
564: pkalg = buffer_get_string(&b, &alen);
565: buffer_free(&b);
566: } else {
567: pkalg = packet_get_string(&alen);
568: pkblob = packet_get_string(&blen);
569: }
1.90 markus 570: packet_check_eom();
1.51 markus 571:
1.117 markus 572: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 573:
1.117 markus 574: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
575: debug("unknown pkalg %s", pkalg);
576: goto done;
577: }
578: if ((key = key_from_blob(pkblob, blen)) == NULL) {
579: debug("no key from blob. pkalg %s", pkalg);
580: goto done;
581: }
582: if (key->type != pktype) {
583: error("input_userauth_pk_ok: type mismatch "
584: "for decoded key (received %d, expected %d)",
585: key->type, pktype);
586: goto done;
587: }
588: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
589: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 590: free(fp);
1.117 markus 591:
1.127 markus 592: /*
593: * search keys in the reverse order, because last candidate has been
594: * moved to the end of the queue. this also avoids confusion by
595: * duplicate keys
596: */
1.136 henning 597: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 598: if (key_equal(key, id->key)) {
599: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 600: break;
601: }
1.117 markus 602: }
603: done:
1.51 markus 604: if (key != NULL)
605: key_free(key);
1.197 djm 606: free(pkalg);
607: free(pkblob);
1.51 markus 608:
1.106 deraadt 609: /* try another method if we did not send a packet */
1.51 markus 610: if (sent == 0)
611: userauth(authctxt, NULL);
1.20 markus 612: }
1.121 markus 613:
614: #ifdef GSSAPI
1.133 djm 615: int
1.121 markus 616: userauth_gssapi(Authctxt *authctxt)
617: {
618: Gssctxt *gssctxt = NULL;
1.128 avsm 619: static gss_OID_set gss_supported = NULL;
1.139 djm 620: static u_int mech = 0;
1.121 markus 621: OM_uint32 min;
622: int ok = 0;
623:
624: /* Try one GSSAPI method at a time, rather than sending them all at
625: * once. */
626:
1.128 avsm 627: if (gss_supported == NULL)
628: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 629:
630: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 631: while (mech < gss_supported->count && !ok) {
1.121 markus 632: /* My DER encoding requires length<128 */
1.128 avsm 633: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 634: ssh_gssapi_check_mechanism(&gssctxt,
635: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 636: ok = 1; /* Mechanism works */
637: } else {
638: mech++;
639: }
640: }
641:
1.161 djm 642: if (!ok)
1.139 djm 643: return 0;
1.121 markus 644:
645: authctxt->methoddata=(void *)gssctxt;
646:
647: packet_start(SSH2_MSG_USERAUTH_REQUEST);
648: packet_put_cstring(authctxt->server_user);
649: packet_put_cstring(authctxt->service);
650: packet_put_cstring(authctxt->method->name);
651:
652: packet_put_int(1);
653:
1.129 markus 654: packet_put_int((gss_supported->elements[mech].length) + 2);
655: packet_put_char(SSH_GSS_OIDTYPE);
656: packet_put_char(gss_supported->elements[mech].length);
657: packet_put_raw(gss_supported->elements[mech].elements,
658: gss_supported->elements[mech].length);
1.121 markus 659:
660: packet_send();
661:
662: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
663: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
664: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
665: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
666:
667: mech++; /* Move along to next candidate */
668:
669: return 1;
670: }
671:
1.130 markus 672: static OM_uint32
673: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
674: {
675: Authctxt *authctxt = ctxt;
676: Gssctxt *gssctxt = authctxt->methoddata;
677: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 678: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
679: gss_buffer_desc gssbuf;
1.132 markus 680: OM_uint32 status, ms, flags;
681: Buffer b;
1.133 djm 682:
1.130 markus 683: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 684: recv_tok, &send_tok, &flags);
1.130 markus 685:
686: if (send_tok.length > 0) {
687: if (GSS_ERROR(status))
688: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
689: else
690: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 691:
1.130 markus 692: packet_put_string(send_tok.value, send_tok.length);
693: packet_send();
694: gss_release_buffer(&ms, &send_tok);
695: }
1.133 djm 696:
1.130 markus 697: if (status == GSS_S_COMPLETE) {
1.132 markus 698: /* send either complete or MIC, depending on mechanism */
699: if (!(flags & GSS_C_INTEG_FLAG)) {
700: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
701: packet_send();
702: } else {
703: ssh_gssapi_buildmic(&b, authctxt->server_user,
704: authctxt->service, "gssapi-with-mic");
705:
706: gssbuf.value = buffer_ptr(&b);
707: gssbuf.length = buffer_len(&b);
1.133 djm 708:
1.132 markus 709: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 710:
1.132 markus 711: if (!GSS_ERROR(status)) {
712: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
713: packet_put_string(mic.value, mic.length);
1.133 djm 714:
1.132 markus 715: packet_send();
716: }
1.133 djm 717:
1.132 markus 718: buffer_free(&b);
719: gss_release_buffer(&ms, &mic);
1.133 djm 720: }
1.130 markus 721: }
1.133 djm 722:
1.130 markus 723: return status;
724: }
725:
1.169 djm 726: /* ARGSUSED */
1.121 markus 727: void
728: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
729: {
730: Authctxt *authctxt = ctxt;
731: Gssctxt *gssctxt;
732: int oidlen;
733: char *oidv;
734:
735: if (authctxt == NULL)
736: fatal("input_gssapi_response: no authentication context");
737: gssctxt = authctxt->methoddata;
738:
739: /* Setup our OID */
740: oidv = packet_get_string(&oidlen);
741:
1.129 markus 742: if (oidlen <= 2 ||
743: oidv[0] != SSH_GSS_OIDTYPE ||
744: oidv[1] != oidlen - 2) {
1.197 djm 745: free(oidv);
1.129 markus 746: debug("Badly encoded mechanism OID received");
747: userauth(authctxt, NULL);
748: return;
1.121 markus 749: }
1.129 markus 750:
751: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
752: fatal("Server returned different OID than expected");
1.121 markus 753:
754: packet_check_eom();
755:
1.197 djm 756: free(oidv);
1.121 markus 757:
1.130 markus 758: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 759: /* Start again with next method on list */
760: debug("Trying to start again");
761: userauth(authctxt, NULL);
762: return;
763: }
764: }
765:
1.169 djm 766: /* ARGSUSED */
1.121 markus 767: void
768: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
769: {
770: Authctxt *authctxt = ctxt;
771: gss_buffer_desc recv_tok;
1.130 markus 772: OM_uint32 status;
1.121 markus 773: u_int slen;
774:
775: if (authctxt == NULL)
776: fatal("input_gssapi_response: no authentication context");
777:
778: recv_tok.value = packet_get_string(&slen);
779: recv_tok.length = slen; /* safe typecast */
780:
781: packet_check_eom();
782:
1.130 markus 783: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 784:
1.197 djm 785: free(recv_tok.value);
1.121 markus 786:
787: if (GSS_ERROR(status)) {
788: /* Start again with the next method in the list */
789: userauth(authctxt, NULL);
790: return;
791: }
792: }
793:
1.169 djm 794: /* ARGSUSED */
1.121 markus 795: void
796: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
797: {
798: Authctxt *authctxt = ctxt;
799: Gssctxt *gssctxt;
800: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
801: gss_buffer_desc recv_tok;
1.194 djm 802: OM_uint32 ms;
1.123 deraadt 803: u_int len;
1.121 markus 804:
805: if (authctxt == NULL)
806: fatal("input_gssapi_response: no authentication context");
807: gssctxt = authctxt->methoddata;
808:
1.123 deraadt 809: recv_tok.value = packet_get_string(&len);
810: recv_tok.length = len;
1.121 markus 811:
812: packet_check_eom();
813:
814: /* Stick it into GSSAPI and see what it says */
1.194 djm 815: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 816: &recv_tok, &send_tok, NULL);
1.121 markus 817:
1.197 djm 818: free(recv_tok.value);
1.121 markus 819: gss_release_buffer(&ms, &send_tok);
820:
821: /* Server will be returning a failed packet after this one */
822: }
823:
1.169 djm 824: /* ARGSUSED */
1.121 markus 825: void
826: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
827: {
828: char *msg;
829: char *lang;
830:
1.194 djm 831: /* maj */(void)packet_get_int();
832: /* min */(void)packet_get_int();
1.121 markus 833: msg=packet_get_string(NULL);
834: lang=packet_get_string(NULL);
835:
836: packet_check_eom();
837:
1.143 stevesk 838: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 839: free(msg);
840: free(lang);
1.121 markus 841: }
842: #endif /* GSSAPI */
1.20 markus 843:
1.1 markus 844: int
1.23 markus 845: userauth_none(Authctxt *authctxt)
846: {
847: /* initial userauth request */
848: packet_start(SSH2_MSG_USERAUTH_REQUEST);
849: packet_put_cstring(authctxt->server_user);
850: packet_put_cstring(authctxt->service);
851: packet_put_cstring(authctxt->method->name);
852: packet_send();
853: return 1;
854: }
855:
856: int
1.20 markus 857: userauth_passwd(Authctxt *authctxt)
1.1 markus 858: {
1.6 markus 859: static int attempt = 0;
1.99 markus 860: char prompt[150];
1.1 markus 861: char *password;
1.175 dtucker 862: const char *host = options.host_key_alias ? options.host_key_alias :
863: authctxt->host;
1.6 markus 864:
1.13 todd 865: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 866: return 0;
1.13 todd 867:
1.87 deraadt 868: if (attempt != 1)
1.13 todd 869: error("Permission denied, please try again.");
1.1 markus 870:
1.43 itojun 871: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 872: authctxt->server_user, host);
1.1 markus 873: password = read_passphrase(prompt, 0);
874: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 875: packet_put_cstring(authctxt->server_user);
876: packet_put_cstring(authctxt->service);
1.23 markus 877: packet_put_cstring(authctxt->method->name);
1.1 markus 878: packet_put_char(0);
1.49 markus 879: packet_put_cstring(password);
1.1 markus 880: memset(password, 0, strlen(password));
1.197 djm 881: free(password);
1.85 markus 882: packet_add_padding(64);
1.1 markus 883: packet_send();
1.99 markus 884:
1.104 deraadt 885: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 886: &input_userauth_passwd_changereq);
887:
1.1 markus 888: return 1;
889: }
1.169 djm 890:
1.99 markus 891: /*
892: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
893: */
1.169 djm 894: /* ARGSUSED */
1.99 markus 895: void
1.153 djm 896: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 897: {
898: Authctxt *authctxt = ctxt;
899: char *info, *lang, *password = NULL, *retype = NULL;
900: char prompt[150];
1.175 dtucker 901: const char *host = options.host_key_alias ? options.host_key_alias :
902: authctxt->host;
1.99 markus 903:
904: debug2("input_userauth_passwd_changereq");
905:
906: if (authctxt == NULL)
907: fatal("input_userauth_passwd_changereq: "
908: "no authentication context");
909:
910: info = packet_get_string(NULL);
911: lang = packet_get_string(NULL);
912: if (strlen(info) > 0)
1.116 itojun 913: logit("%s", info);
1.197 djm 914: free(info);
915: free(lang);
1.99 markus 916: packet_start(SSH2_MSG_USERAUTH_REQUEST);
917: packet_put_cstring(authctxt->server_user);
918: packet_put_cstring(authctxt->service);
919: packet_put_cstring(authctxt->method->name);
920: packet_put_char(1); /* additional info */
1.104 deraadt 921: snprintf(prompt, sizeof(prompt),
1.99 markus 922: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 923: authctxt->server_user, host);
1.99 markus 924: password = read_passphrase(prompt, 0);
925: packet_put_cstring(password);
926: memset(password, 0, strlen(password));
1.197 djm 927: free(password);
1.99 markus 928: password = NULL;
929: while (password == NULL) {
1.104 deraadt 930: snprintf(prompt, sizeof(prompt),
1.99 markus 931: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 932: authctxt->server_user, host);
1.99 markus 933: password = read_passphrase(prompt, RP_ALLOW_EOF);
934: if (password == NULL) {
935: /* bail out */
936: return;
937: }
1.104 deraadt 938: snprintf(prompt, sizeof(prompt),
1.99 markus 939: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 940: authctxt->server_user, host);
1.99 markus 941: retype = read_passphrase(prompt, 0);
942: if (strcmp(password, retype) != 0) {
943: memset(password, 0, strlen(password));
1.197 djm 944: free(password);
1.116 itojun 945: logit("Mismatch; try again, EOF to quit.");
1.99 markus 946: password = NULL;
947: }
948: memset(retype, 0, strlen(retype));
1.197 djm 949: free(retype);
1.99 markus 950: }
951: packet_put_cstring(password);
952: memset(password, 0, strlen(password));
1.197 djm 953: free(password);
1.99 markus 954: packet_add_padding(64);
955: packet_send();
1.104 deraadt 956:
957: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 958: &input_userauth_passwd_changereq);
1.117 markus 959: }
960:
1.170 djm 961: #ifdef JPAKE
962: static char *
963: pw_encrypt(const char *password, const char *crypt_scheme, const char *salt)
964: {
965: /* OpenBSD crypt(3) handles all of these */
966: if (strcmp(crypt_scheme, "crypt") == 0 ||
967: strcmp(crypt_scheme, "bcrypt") == 0 ||
968: strcmp(crypt_scheme, "md5crypt") == 0 ||
969: strcmp(crypt_scheme, "crypt-extended") == 0)
970: return xstrdup(crypt(password, salt));
971: error("%s: unsupported password encryption scheme \"%.100s\"",
972: __func__, crypt_scheme);
973: return NULL;
974: }
975:
976: static BIGNUM *
977: jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
978: const char *salt)
979: {
980: char prompt[256], *password, *crypted;
981: u_char *secret;
982: u_int secret_len;
983: BIGNUM *ret;
984:
985: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
986: authctxt->server_user, authctxt->host);
987: password = read_passphrase(prompt, 0);
988:
989: if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
990: logit("Disabling %s authentication", authctxt->method->name);
991: authctxt->method->enabled = NULL;
992: /* Continue with an empty password to fail gracefully */
993: crypted = xstrdup("");
994: }
995:
996: #ifdef JPAKE_DEBUG
997: debug3("%s: salt = %s", __func__, salt);
998: debug3("%s: scheme = %s", __func__, crypt_scheme);
999: debug3("%s: crypted = %s", __func__, crypted);
1000: #endif
1001:
1002: if (hash_buffer(crypted, strlen(crypted), EVP_sha256(),
1003: &secret, &secret_len) != 0)
1004: fatal("%s: hash_buffer", __func__);
1005:
1006: bzero(password, strlen(password));
1007: bzero(crypted, strlen(crypted));
1.197 djm 1008: free(password);
1009: free(crypted);
1.170 djm 1010:
1011: if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL)
1012: fatal("%s: BN_bin2bn (secret)", __func__);
1013: bzero(secret, secret_len);
1.197 djm 1014: free(secret);
1.170 djm 1015:
1016: return ret;
1017: }
1018:
1019: /* ARGSUSED */
1020: void
1021: input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt)
1022: {
1023: Authctxt *authctxt = ctxt;
1024: struct jpake_ctx *pctx = authctxt->methoddata;
1025: u_char *x3_proof, *x4_proof, *x2_s_proof;
1026: u_int x3_proof_len, x4_proof_len, x2_s_proof_len;
1027: char *crypt_scheme, *salt;
1028:
1029: /* Disable this message */
1030: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1, NULL);
1031:
1032: if ((pctx->g_x3 = BN_new()) == NULL ||
1033: (pctx->g_x4 = BN_new()) == NULL)
1034: fatal("%s: BN_new", __func__);
1035:
1036: /* Fetch step 1 values */
1037: crypt_scheme = packet_get_string(NULL);
1038: salt = packet_get_string(NULL);
1039: pctx->server_id = packet_get_string(&pctx->server_id_len);
1040: packet_get_bignum2(pctx->g_x3);
1041: packet_get_bignum2(pctx->g_x4);
1042: x3_proof = packet_get_string(&x3_proof_len);
1043: x4_proof = packet_get_string(&x4_proof_len);
1044: packet_check_eom();
1045:
1046: JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__));
1047:
1048: /* Obtain password and derive secret */
1049: pctx->s = jpake_password_to_secret(authctxt, crypt_scheme, salt);
1050: bzero(crypt_scheme, strlen(crypt_scheme));
1051: bzero(salt, strlen(salt));
1.197 djm 1052: free(crypt_scheme);
1053: free(salt);
1.170 djm 1054: JPAKE_DEBUG_BN((pctx->s, "%s: s = ", __func__));
1055:
1056: /* Calculate step 2 values */
1057: jpake_step2(pctx->grp, pctx->s, pctx->g_x1,
1058: pctx->g_x3, pctx->g_x4, pctx->x2,
1059: pctx->server_id, pctx->server_id_len,
1060: pctx->client_id, pctx->client_id_len,
1061: x3_proof, x3_proof_len,
1062: x4_proof, x4_proof_len,
1063: &pctx->a,
1064: &x2_s_proof, &x2_s_proof_len);
1065:
1066: bzero(x3_proof, x3_proof_len);
1067: bzero(x4_proof, x4_proof_len);
1.197 djm 1068: free(x3_proof);
1069: free(x4_proof);
1.170 djm 1070:
1071: JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__));
1072:
1073: /* Send values for step 2 */
1074: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2);
1075: packet_put_bignum2(pctx->a);
1076: packet_put_string(x2_s_proof, x2_s_proof_len);
1077: packet_send();
1078:
1079: bzero(x2_s_proof, x2_s_proof_len);
1.197 djm 1080: free(x2_s_proof);
1.170 djm 1081:
1082: /* Expect step 2 packet from peer */
1083: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2,
1084: input_userauth_jpake_server_step2);
1085: }
1086:
1087: /* ARGSUSED */
1088: void
1089: input_userauth_jpake_server_step2(int type, u_int32_t seq, void *ctxt)
1090: {
1091: Authctxt *authctxt = ctxt;
1092: struct jpake_ctx *pctx = authctxt->methoddata;
1093: u_char *x4_s_proof;
1094: u_int x4_s_proof_len;
1095:
1096: /* Disable this message */
1097: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL);
1098:
1099: if ((pctx->b = BN_new()) == NULL)
1100: fatal("%s: BN_new", __func__);
1101:
1102: /* Fetch step 2 values */
1103: packet_get_bignum2(pctx->b);
1104: x4_s_proof = packet_get_string(&x4_s_proof_len);
1105: packet_check_eom();
1106:
1107: JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__));
1108:
1109: /* Derive shared key and calculate confirmation hash */
1110: jpake_key_confirm(pctx->grp, pctx->s, pctx->b,
1111: pctx->x2, pctx->g_x1, pctx->g_x2, pctx->g_x3, pctx->g_x4,
1112: pctx->client_id, pctx->client_id_len,
1113: pctx->server_id, pctx->server_id_len,
1114: session_id2, session_id2_len,
1115: x4_s_proof, x4_s_proof_len,
1116: &pctx->k,
1117: &pctx->h_k_cid_sessid, &pctx->h_k_cid_sessid_len);
1118:
1119: bzero(x4_s_proof, x4_s_proof_len);
1.197 djm 1120: free(x4_s_proof);
1.170 djm 1121:
1122: JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__));
1123:
1124: /* Send key confirmation proof */
1125: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM);
1126: packet_put_string(pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len);
1127: packet_send();
1128:
1129: /* Expect confirmation from peer */
1130: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM,
1131: input_userauth_jpake_server_confirm);
1132: }
1133:
1134: /* ARGSUSED */
1135: void
1136: input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt)
1137: {
1138: Authctxt *authctxt = ctxt;
1139: struct jpake_ctx *pctx = authctxt->methoddata;
1140:
1141: /* Disable this message */
1142: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL);
1143:
1144: pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len);
1145: packet_check_eom();
1146:
1147: JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__));
1148:
1149: /* Verify expected confirmation hash */
1150: if (jpake_check_confirm(pctx->k,
1151: pctx->server_id, pctx->server_id_len,
1152: session_id2, session_id2_len,
1153: pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len) == 1)
1154: debug("%s: %s success", __func__, authctxt->method->name);
1155: else {
1156: debug("%s: confirmation mismatch", __func__);
1157: /* XXX stash this so if auth succeeds then we can warn/kill */
1158: }
1159:
1160: userauth_jpake_cleanup(authctxt);
1161: }
1162: #endif /* JPAKE */
1163:
1.117 markus 1164: static int
1165: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
1166: u_char *data, u_int datalen)
1167: {
1168: Key *prv;
1169: int ret;
1.99 markus 1170:
1.117 markus 1171: /* the agent supports this key */
1172: if (id->ac)
1173: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
1174: data, datalen));
1175: /*
1176: * we have already loaded the private key or
1177: * the private key is stored in external hardware
1178: */
1179: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
1180: return (key_sign(id->key, sigp, lenp, data, datalen));
1181: /* load the private key from the file */
1.191 dtucker 1182: if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
1.117 markus 1183: return (-1);
1184: ret = key_sign(prv, sigp, lenp, data, datalen);
1185: key_free(prv);
1186: return (ret);
1.51 markus 1187: }
1188:
1.76 itojun 1189: static int
1.117 markus 1190: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1191: {
1192: Buffer b;
1.32 markus 1193: u_char *blob, *signature;
1.96 markus 1194: u_int bloblen, slen;
1.120 markus 1195: u_int skip = 0;
1.17 markus 1196: int ret = -1;
1.23 markus 1197: int have_sig = 1;
1.182 djm 1198: char *fp;
1.1 markus 1199:
1.182 djm 1200: fp = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
1201: debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1.197 djm 1202: free(fp);
1.51 markus 1203:
1.117 markus 1204: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1205: /* we cannot handle this key */
1.30 markus 1206: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1207: return 0;
1208: }
1.1 markus 1209: /* data to be signed */
1210: buffer_init(&b);
1.26 markus 1211: if (datafellows & SSH_OLD_SESSIONID) {
1212: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1213: skip = session_id2_len;
1.26 markus 1214: } else {
1.14 markus 1215: buffer_put_string(&b, session_id2, session_id2_len);
1216: skip = buffer_len(&b);
1217: }
1.1 markus 1218: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1219: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1220: buffer_put_cstring(&b,
1.30 markus 1221: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1222: "ssh-userauth" :
1.20 markus 1223: authctxt->service);
1.30 markus 1224: if (datafellows & SSH_BUG_PKAUTH) {
1225: buffer_put_char(&b, have_sig);
1226: } else {
1227: buffer_put_cstring(&b, authctxt->method->name);
1228: buffer_put_char(&b, have_sig);
1.117 markus 1229: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1230: }
1.1 markus 1231: buffer_put_string(&b, blob, bloblen);
1232:
1233: /* generate signature */
1.117 markus 1234: ret = identity_sign(id, &signature, &slen,
1.51 markus 1235: buffer_ptr(&b), buffer_len(&b));
1.17 markus 1236: if (ret == -1) {
1.197 djm 1237: free(blob);
1.17 markus 1238: buffer_free(&b);
1239: return 0;
1240: }
1.28 markus 1241: #ifdef DEBUG_PK
1.1 markus 1242: buffer_dump(&b);
1243: #endif
1.30 markus 1244: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1245: buffer_clear(&b);
1246: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1247: skip = session_id2_len;
1.10 markus 1248: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1249: buffer_put_cstring(&b, authctxt->server_user);
1250: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1251: buffer_put_cstring(&b, authctxt->method->name);
1252: buffer_put_char(&b, have_sig);
1.30 markus 1253: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1254: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1255: buffer_put_string(&b, blob, bloblen);
1256: }
1.197 djm 1257: free(blob);
1.51 markus 1258:
1.1 markus 1259: /* append signature */
1260: buffer_put_string(&b, signature, slen);
1.197 djm 1261: free(signature);
1.1 markus 1262:
1263: /* skip session id and packet type */
1.14 markus 1264: if (buffer_len(&b) < skip + 1)
1.20 markus 1265: fatal("userauth_pubkey: internal error");
1.14 markus 1266: buffer_consume(&b, skip + 1);
1.1 markus 1267:
1268: /* put remaining data from buffer into packet */
1269: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1270: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1271: buffer_free(&b);
1272: packet_send();
1.17 markus 1273:
1274: return 1;
1.16 markus 1275: }
1276:
1.76 itojun 1277: static int
1.117 markus 1278: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1279: {
1.51 markus 1280: u_char *blob;
1.97 markus 1281: u_int bloblen, have_sig = 0;
1.20 markus 1282:
1.51 markus 1283: debug3("send_pubkey_test");
1.16 markus 1284:
1.117 markus 1285: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1286: /* we cannot handle this key */
1287: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1288: return 0;
1289: }
1.51 markus 1290: /* register callback for USERAUTH_PK_OK message */
1291: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1292:
1293: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1294: packet_put_cstring(authctxt->server_user);
1295: packet_put_cstring(authctxt->service);
1296: packet_put_cstring(authctxt->method->name);
1297: packet_put_char(have_sig);
1298: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1299: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1300: packet_put_string(blob, bloblen);
1.197 djm 1301: free(blob);
1.51 markus 1302: packet_send();
1303: return 1;
1304: }
1305:
1.76 itojun 1306: static Key *
1.191 dtucker 1307: load_identity_file(char *filename, int userprovided)
1.51 markus 1308: {
1309: Key *private;
1310: char prompt[300], *passphrase;
1.178 dtucker 1311: int perm_ok = 0, quit, i;
1.52 markus 1312: struct stat st;
1.16 markus 1313:
1.52 markus 1314: if (stat(filename, &st) < 0) {
1.191 dtucker 1315: (userprovided ? logit : debug3)("no such identity: %s: %s",
1316: filename, strerror(errno));
1.52 markus 1317: return NULL;
1318: }
1.152 dtucker 1319: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
1.198 dtucker 1320: if (!perm_ok) {
1321: if (private != NULL)
1322: key_free(private);
1.152 dtucker 1323: return NULL;
1.198 dtucker 1324: }
1.56 markus 1325: if (private == NULL) {
1326: if (options.batch_mode)
1.51 markus 1327: return NULL;
1.16 markus 1328: snprintf(prompt, sizeof prompt,
1.88 deraadt 1329: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 1330: for (i = 0; i < options.number_of_password_prompts; i++) {
1331: passphrase = read_passphrase(prompt, 0);
1332: if (strcmp(passphrase, "") != 0) {
1.152 dtucker 1333: private = key_load_private_type(KEY_UNSPEC,
1334: filename, passphrase, NULL, NULL);
1.51 markus 1335: quit = 0;
1.20 markus 1336: } else {
1337: debug2("no passphrase given, try next key");
1.51 markus 1338: quit = 1;
1.20 markus 1339: }
1340: memset(passphrase, 0, strlen(passphrase));
1.197 djm 1341: free(passphrase);
1.56 markus 1342: if (private != NULL || quit)
1.20 markus 1343: break;
1344: debug2("bad passphrase given, try again...");
1.16 markus 1345: }
1346: }
1.51 markus 1347: return private;
1348: }
1349:
1.117 markus 1350: /*
1351: * try keys in the following order:
1352: * 1. agent keys that are found in the config file
1353: * 2. other agent keys
1354: * 3. keys that are only listed in the config file
1355: */
1356: static void
1357: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1358: {
1.190 djm 1359: Identity *id, *id2, *tmp;
1.117 markus 1360: Idlist agent, files, *preferred;
1361: Key *key;
1362: AuthenticationConnection *ac;
1363: char *comment;
1364: int i, found;
1.51 markus 1365:
1.117 markus 1366: TAILQ_INIT(&agent); /* keys from the agent */
1367: TAILQ_INIT(&files); /* keys from the config file */
1368: preferred = &authctxt->keys;
1369: TAILQ_INIT(preferred); /* preferred order of keys */
1370:
1.190 djm 1371: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1372: for (i = 0; i < options.num_identity_files; i++) {
1373: key = options.identity_keys[i];
1374: if (key && key->type == KEY_RSA1)
1.180 djm 1375: continue;
1376: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1377: continue;
1378: options.identity_keys[i] = NULL;
1.150 djm 1379: id = xcalloc(1, sizeof(*id));
1.117 markus 1380: id->key = key;
1381: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1382: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1383: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1384: }
1385: /* Prefer PKCS11 keys that are explicitly listed */
1386: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1387: if (id->key == NULL || (id->key->flags & KEY_FLAG_EXT) == 0)
1388: continue;
1389: found = 0;
1390: TAILQ_FOREACH(id2, &files, next) {
1391: if (id2->key == NULL ||
1392: (id2->key->flags & KEY_FLAG_EXT) != 0)
1393: continue;
1394: if (key_equal(id->key, id2->key)) {
1395: TAILQ_REMOVE(&files, id, next);
1396: TAILQ_INSERT_TAIL(preferred, id, next);
1397: found = 1;
1398: break;
1399: }
1400: }
1401: /* If IdentitiesOnly set and key not found then don't use it */
1402: if (!found && options.identities_only) {
1403: TAILQ_REMOVE(&files, id, next);
1.195 djm 1404: bzero(id, sizeof(*id));
1.190 djm 1405: free(id);
1406: }
1.117 markus 1407: }
1408: /* list of keys supported by the agent */
1409: if ((ac = ssh_get_authentication_connection())) {
1410: for (key = ssh_get_first_identity(ac, &comment, 2);
1411: key != NULL;
1412: key = ssh_get_next_identity(ac, &comment, 2)) {
1413: found = 0;
1414: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1415: /* agent keys from the config file are preferred */
1.117 markus 1416: if (key_equal(key, id->key)) {
1417: key_free(key);
1.197 djm 1418: free(comment);
1.117 markus 1419: TAILQ_REMOVE(&files, id, next);
1420: TAILQ_INSERT_TAIL(preferred, id, next);
1421: id->ac = ac;
1422: found = 1;
1423: break;
1424: }
1425: }
1.135 markus 1426: if (!found && !options.identities_only) {
1.150 djm 1427: id = xcalloc(1, sizeof(*id));
1.117 markus 1428: id->key = key;
1429: id->filename = comment;
1430: id->ac = ac;
1431: TAILQ_INSERT_TAIL(&agent, id, next);
1432: }
1433: }
1434: /* append remaining agent keys */
1435: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1436: TAILQ_REMOVE(&agent, id, next);
1437: TAILQ_INSERT_TAIL(preferred, id, next);
1438: }
1439: authctxt->agent = ac;
1440: }
1441: /* append remaining keys from the config file */
1442: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1443: TAILQ_REMOVE(&files, id, next);
1444: TAILQ_INSERT_TAIL(preferred, id, next);
1445: }
1446: TAILQ_FOREACH(id, preferred, next) {
1.191 dtucker 1447: debug2("key: %s (%p),%s", id->filename, id->key,
1448: id->userprovided ? " explicit" : "");
1.117 markus 1449: }
1.17 markus 1450: }
1451:
1.117 markus 1452: static void
1453: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1454: {
1.117 markus 1455: Identity *id;
1.51 markus 1456:
1.117 markus 1457: if (authctxt->agent != NULL)
1458: ssh_close_authentication_connection(authctxt->agent);
1459: for (id = TAILQ_FIRST(&authctxt->keys); id;
1460: id = TAILQ_FIRST(&authctxt->keys)) {
1461: TAILQ_REMOVE(&authctxt->keys, id, next);
1462: if (id->key)
1463: key_free(id->key);
1.197 djm 1464: free(id->filename);
1465: free(id);
1.117 markus 1466: }
1.1 markus 1467: }
1468:
1.20 markus 1469: int
1470: userauth_pubkey(Authctxt *authctxt)
1471: {
1.117 markus 1472: Identity *id;
1.20 markus 1473: int sent = 0;
1474:
1.117 markus 1475: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1476: if (id->tried++)
1477: return (0);
1.127 markus 1478: /* move key to the end of the queue */
1.117 markus 1479: TAILQ_REMOVE(&authctxt->keys, id, next);
1480: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1481: /*
1482: * send a test message if we have the public key. for
1483: * encrypted keys we cannot do this and have to load the
1484: * private key instead
1485: */
1486: if (id->key && id->key->type != KEY_RSA1) {
1.181 djm 1487: debug("Offering %s public key: %s", key_type(id->key),
1488: id->filename);
1.117 markus 1489: sent = send_pubkey_test(authctxt, id);
1490: } else if (id->key == NULL) {
1491: debug("Trying private key: %s", id->filename);
1.191 dtucker 1492: id->key = load_identity_file(id->filename,
1493: id->userprovided);
1.117 markus 1494: if (id->key != NULL) {
1495: id->isprivate = 1;
1496: sent = sign_and_send_pubkey(authctxt, id);
1497: key_free(id->key);
1498: id->key = NULL;
1.51 markus 1499: }
1500: }
1.117 markus 1501: if (sent)
1502: return (sent);
1.28 markus 1503: }
1.117 markus 1504: return (0);
1.20 markus 1505: }
1506:
1.23 markus 1507: /*
1508: * Send userauth request message specifying keyboard-interactive method.
1509: */
1510: int
1511: userauth_kbdint(Authctxt *authctxt)
1512: {
1513: static int attempt = 0;
1514:
1515: if (attempt++ >= options.number_of_password_prompts)
1516: return 0;
1.82 markus 1517: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1518: if (attempt > 1 && !authctxt->info_req_seen) {
1519: debug3("userauth_kbdint: disable: no info_req_seen");
1520: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1521: return 0;
1522: }
1.23 markus 1523:
1524: debug2("userauth_kbdint");
1525: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1526: packet_put_cstring(authctxt->server_user);
1527: packet_put_cstring(authctxt->service);
1528: packet_put_cstring(authctxt->method->name);
1529: packet_put_cstring(""); /* lang */
1530: packet_put_cstring(options.kbd_interactive_devices ?
1531: options.kbd_interactive_devices : "");
1532: packet_send();
1533:
1534: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1535: return 1;
1536: }
1537:
1538: /*
1.46 markus 1539: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1540: */
1541: void
1.92 markus 1542: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1543: {
1544: Authctxt *authctxt = ctxt;
1.46 markus 1545: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1546: u_int num_prompts, i;
1.23 markus 1547: int echo = 0;
1548:
1549: debug2("input_userauth_info_req");
1550:
1551: if (authctxt == NULL)
1552: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1553:
1554: authctxt->info_req_seen = 1;
1.23 markus 1555:
1556: name = packet_get_string(NULL);
1557: inst = packet_get_string(NULL);
1558: lang = packet_get_string(NULL);
1559: if (strlen(name) > 0)
1.116 itojun 1560: logit("%s", name);
1.23 markus 1561: if (strlen(inst) > 0)
1.116 itojun 1562: logit("%s", inst);
1.197 djm 1563: free(name);
1564: free(inst);
1565: free(lang);
1.23 markus 1566:
1567: num_prompts = packet_get_int();
1568: /*
1569: * Begin to build info response packet based on prompts requested.
1570: * We commit to providing the correct number of responses, so if
1571: * further on we run into a problem that prevents this, we have to
1572: * be sure and clean this up and send a correct error response.
1573: */
1574: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1575: packet_put_int(num_prompts);
1576:
1.73 markus 1577: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1578: for (i = 0; i < num_prompts; i++) {
1579: prompt = packet_get_string(NULL);
1580: echo = packet_get_char();
1581:
1.77 markus 1582: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1583:
1.49 markus 1584: packet_put_cstring(response);
1.23 markus 1585: memset(response, 0, strlen(response));
1.197 djm 1586: free(response);
1587: free(prompt);
1.23 markus 1588: }
1.90 markus 1589: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1590:
1.85 markus 1591: packet_add_padding(64);
1.23 markus 1592: packet_send();
1.68 markus 1593: }
1594:
1.100 markus 1595: static int
1.105 deraadt 1596: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1597: u_char *data, u_int datalen)
1598: {
1599: Buffer b;
1.101 markus 1600: struct stat st;
1.100 markus 1601: pid_t pid;
1.103 markus 1602: int to[2], from[2], status, version = 2;
1.100 markus 1603:
1.109 markus 1604: debug2("ssh_keysign called");
1.100 markus 1605:
1.101 markus 1606: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.179 dtucker 1607: error("ssh_keysign: not installed: %s", strerror(errno));
1.101 markus 1608: return -1;
1609: }
1.100 markus 1610: if (fflush(stdout) != 0)
1611: error("ssh_keysign: fflush: %s", strerror(errno));
1612: if (pipe(to) < 0) {
1613: error("ssh_keysign: pipe: %s", strerror(errno));
1614: return -1;
1615: }
1616: if (pipe(from) < 0) {
1617: error("ssh_keysign: pipe: %s", strerror(errno));
1618: return -1;
1619: }
1620: if ((pid = fork()) < 0) {
1621: error("ssh_keysign: fork: %s", strerror(errno));
1622: return -1;
1623: }
1624: if (pid == 0) {
1.174 dtucker 1625: /* keep the socket on exec */
1626: fcntl(packet_get_connection_in(), F_SETFD, 0);
1.155 markus 1627: permanently_drop_suid(getuid());
1.100 markus 1628: close(from[0]);
1629: if (dup2(from[1], STDOUT_FILENO) < 0)
1630: fatal("ssh_keysign: dup2: %s", strerror(errno));
1631: close(to[1]);
1632: if (dup2(to[0], STDIN_FILENO) < 0)
1633: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1634: close(from[1]);
1635: close(to[0]);
1.102 markus 1636: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1637: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1638: strerror(errno));
1639: }
1640: close(from[1]);
1641: close(to[0]);
1642:
1643: buffer_init(&b);
1.103 markus 1644: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1645: buffer_put_string(&b, data, datalen);
1.131 djm 1646: if (ssh_msg_send(to[1], version, &b) == -1)
1647: fatal("ssh_keysign: couldn't send request");
1.100 markus 1648:
1.110 djm 1649: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1650: error("ssh_keysign: no reply");
1.134 markus 1651: buffer_free(&b);
1.100 markus 1652: return -1;
1653: }
1.101 markus 1654: close(from[0]);
1655: close(to[1]);
1656:
1.103 markus 1657: while (waitpid(pid, &status, 0) < 0)
1658: if (errno != EINTR)
1659: break;
1.101 markus 1660:
1.100 markus 1661: if (buffer_get_char(&b) != version) {
1.101 markus 1662: error("ssh_keysign: bad version");
1.134 markus 1663: buffer_free(&b);
1.100 markus 1664: return -1;
1665: }
1666: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1667: buffer_free(&b);
1.100 markus 1668:
1669: return 0;
1670: }
1671:
1.68 markus 1672: int
1673: userauth_hostbased(Authctxt *authctxt)
1674: {
1675: Key *private = NULL;
1.100 markus 1676: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1677: Buffer b;
1678: u_char *signature, *blob;
1.179 dtucker 1679: char *chost, *pkalg, *p;
1.72 markus 1680: const char *service;
1.68 markus 1681: u_int blen, slen;
1.176 dtucker 1682: int ok, i, found = 0;
1.68 markus 1683:
1684: /* check for a useful key */
1.100 markus 1685: for (i = 0; i < sensitive->nkeys; i++) {
1686: private = sensitive->keys[i];
1.68 markus 1687: if (private && private->type != KEY_RSA1) {
1688: found = 1;
1689: /* we take and free the key */
1.100 markus 1690: sensitive->keys[i] = NULL;
1.68 markus 1691: break;
1692: }
1693: }
1694: if (!found) {
1.109 markus 1695: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1696: return 0;
1697: }
1698: if (key_to_blob(private, &blob, &blen) == 0) {
1699: key_free(private);
1700: return 0;
1701: }
1.84 markus 1702: /* figure out a name for the client host */
1.179 dtucker 1703: p = get_local_name(packet_get_connection_in());
1.84 markus 1704: if (p == NULL) {
1705: error("userauth_hostbased: cannot get local ipaddr/name");
1706: key_free(private);
1.197 djm 1707: free(blob);
1.84 markus 1708: return 0;
1709: }
1.150 djm 1710: xasprintf(&chost, "%s.", p);
1.84 markus 1711: debug2("userauth_hostbased: chost %s", chost);
1.197 djm 1712: free(p);
1.84 markus 1713:
1.72 markus 1714: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1715: authctxt->service;
1.68 markus 1716: pkalg = xstrdup(key_ssh_name(private));
1717: buffer_init(&b);
1718: /* construct data */
1.72 markus 1719: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1720: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1721: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1722: buffer_put_cstring(&b, service);
1.68 markus 1723: buffer_put_cstring(&b, authctxt->method->name);
1724: buffer_put_cstring(&b, pkalg);
1725: buffer_put_string(&b, blob, blen);
1726: buffer_put_cstring(&b, chost);
1727: buffer_put_cstring(&b, authctxt->local_user);
1728: #ifdef DEBUG_PK
1729: buffer_dump(&b);
1730: #endif
1.100 markus 1731: if (sensitive->external_keysign)
1732: ok = ssh_keysign(private, &signature, &slen,
1733: buffer_ptr(&b), buffer_len(&b));
1734: else
1735: ok = key_sign(private, &signature, &slen,
1736: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1737: key_free(private);
1738: buffer_free(&b);
1739: if (ok != 0) {
1740: error("key_sign failed");
1.197 djm 1741: free(chost);
1742: free(pkalg);
1743: free(blob);
1.68 markus 1744: return 0;
1745: }
1746: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1747: packet_put_cstring(authctxt->server_user);
1748: packet_put_cstring(authctxt->service);
1749: packet_put_cstring(authctxt->method->name);
1750: packet_put_cstring(pkalg);
1751: packet_put_string(blob, blen);
1752: packet_put_cstring(chost);
1753: packet_put_cstring(authctxt->local_user);
1754: packet_put_string(signature, slen);
1755: memset(signature, 's', slen);
1.197 djm 1756: free(signature);
1757: free(chost);
1758: free(pkalg);
1759: free(blob);
1.68 markus 1760:
1761: packet_send();
1762: return 1;
1.23 markus 1763: }
1.20 markus 1764:
1.170 djm 1765: #ifdef JPAKE
1766: int
1767: userauth_jpake(Authctxt *authctxt)
1768: {
1769: struct jpake_ctx *pctx;
1770: u_char *x1_proof, *x2_proof;
1771: u_int x1_proof_len, x2_proof_len;
1772: static int attempt = 0; /* XXX share with userauth_password's? */
1773:
1774: if (attempt++ >= options.number_of_password_prompts)
1775: return 0;
1776: if (attempt != 1)
1777: error("Permission denied, please try again.");
1778:
1779: if (authctxt->methoddata != NULL)
1780: fatal("%s: authctxt->methoddata already set (%p)",
1781: __func__, authctxt->methoddata);
1782:
1783: authctxt->methoddata = pctx = jpake_new();
1784:
1785: /*
1786: * Send request immediately, to get the protocol going while
1787: * we do the initial computations.
1788: */
1789: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1790: packet_put_cstring(authctxt->server_user);
1791: packet_put_cstring(authctxt->service);
1792: packet_put_cstring(authctxt->method->name);
1793: packet_send();
1794: packet_write_wait();
1795:
1796: jpake_step1(pctx->grp,
1797: &pctx->client_id, &pctx->client_id_len,
1798: &pctx->x1, &pctx->x2, &pctx->g_x1, &pctx->g_x2,
1799: &x1_proof, &x1_proof_len,
1800: &x2_proof, &x2_proof_len);
1801:
1802: JPAKE_DEBUG_CTX((pctx, "step 1 sending in %s", __func__));
1803:
1804: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1);
1805: packet_put_string(pctx->client_id, pctx->client_id_len);
1806: packet_put_bignum2(pctx->g_x1);
1807: packet_put_bignum2(pctx->g_x2);
1808: packet_put_string(x1_proof, x1_proof_len);
1809: packet_put_string(x2_proof, x2_proof_len);
1810: packet_send();
1811:
1812: bzero(x1_proof, x1_proof_len);
1813: bzero(x2_proof, x2_proof_len);
1.197 djm 1814: free(x1_proof);
1815: free(x2_proof);
1.170 djm 1816:
1817: /* Expect step 1 packet from peer */
1818: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1,
1819: input_userauth_jpake_server_step1);
1.172 djm 1820: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS,
1821: &input_userauth_success_unexpected);
1.170 djm 1822:
1823: return 1;
1824: }
1825:
1826: void
1827: userauth_jpake_cleanup(Authctxt *authctxt)
1828: {
1829: debug3("%s: clean up", __func__);
1830: if (authctxt->methoddata != NULL) {
1831: jpake_free(authctxt->methoddata);
1832: authctxt->methoddata = NULL;
1833: }
1.172 djm 1834: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
1.170 djm 1835: }
1836: #endif /* JPAKE */
1837:
1.20 markus 1838: /* find auth method */
1839:
1840: /*
1841: * given auth method name, if configurable options permit this method fill
1842: * in auth_ident field and return true, otherwise return false.
1843: */
1.76 itojun 1844: static int
1.20 markus 1845: authmethod_is_enabled(Authmethod *method)
1846: {
1847: if (method == NULL)
1848: return 0;
1849: /* return false if options indicate this method is disabled */
1850: if (method->enabled == NULL || *method->enabled == 0)
1851: return 0;
1852: /* return false if batch mode is enabled but method needs interactive mode */
1853: if (method->batch_flag != NULL && *method->batch_flag != 0)
1854: return 0;
1855: return 1;
1856: }
1857:
1.76 itojun 1858: static Authmethod *
1.20 markus 1859: authmethod_lookup(const char *name)
1.1 markus 1860: {
1.20 markus 1861: Authmethod *method = NULL;
1862: if (name != NULL)
1863: for (method = authmethods; method->name != NULL; method++)
1864: if (strcmp(name, method->name) == 0)
1865: return method;
1866: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1867: return NULL;
1868: }
1.1 markus 1869:
1.53 markus 1870: /* XXX internal state */
1871: static Authmethod *current = NULL;
1872: static char *supported = NULL;
1873: static char *preferred = NULL;
1.105 deraadt 1874:
1.20 markus 1875: /*
1876: * Given the authentication method list sent by the server, return the
1877: * next method we should try. If the server initially sends a nil list,
1.67 markus 1878: * use a built-in default list.
1.41 stevesk 1879: */
1.76 itojun 1880: static Authmethod *
1.20 markus 1881: authmethod_get(char *authlist)
1882: {
1.53 markus 1883: char *name = NULL;
1.97 markus 1884: u_int next;
1.41 stevesk 1885:
1.20 markus 1886: /* Use a suitable default if we're passed a nil list. */
1887: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1888: authlist = options.preferred_authentications;
1.20 markus 1889:
1.53 markus 1890: if (supported == NULL || strcmp(authlist, supported) != 0) {
1891: debug3("start over, passed a different list %s", authlist);
1.197 djm 1892: free(supported);
1.53 markus 1893: supported = xstrdup(authlist);
1894: preferred = options.preferred_authentications;
1895: debug3("preferred %s", preferred);
1896: current = NULL;
1897: } else if (current != NULL && authmethod_is_enabled(current))
1898: return current;
1.20 markus 1899:
1.53 markus 1900: for (;;) {
1901: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1902: debug("No more authentication methods to try.");
1.53 markus 1903: current = NULL;
1904: return NULL;
1905: }
1906: preferred += next;
1.23 markus 1907: debug3("authmethod_lookup %s", name);
1.53 markus 1908: debug3("remaining preferred: %s", preferred);
1909: if ((current = authmethod_lookup(name)) != NULL &&
1910: authmethod_is_enabled(current)) {
1.23 markus 1911: debug3("authmethod_is_enabled %s", name);
1.109 markus 1912: debug("Next authentication method: %s", name);
1.197 djm 1913: free(name);
1.53 markus 1914: return current;
1.23 markus 1915: }
1.198 dtucker 1916: free(name);
1.1 markus 1917: }
1.53 markus 1918: }
1.1 markus 1919:
1.79 stevesk 1920: static char *
1.53 markus 1921: authmethods_get(void)
1922: {
1923: Authmethod *method = NULL;
1.93 markus 1924: Buffer b;
1925: char *list;
1.27 provos 1926:
1.93 markus 1927: buffer_init(&b);
1.53 markus 1928: for (method = authmethods; method->name != NULL; method++) {
1929: if (authmethod_is_enabled(method)) {
1.93 markus 1930: if (buffer_len(&b) > 0)
1931: buffer_append(&b, ",", 1);
1932: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1933: }
1934: }
1.93 markus 1935: buffer_append(&b, "\0", 1);
1936: list = xstrdup(buffer_ptr(&b));
1937: buffer_free(&b);
1938: return list;
1.1 markus 1939: }
1.170 djm 1940:
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