Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.192
1.192 ! dtucker 1: /* $OpenBSD: sshconnect2.c,v 1.191 2013/02/15 00:21:01 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:
143: xfree(first);
144: xfree(last);
145: xfree(hostname);
146: xfree(oavail);
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:
194: if (options.rekey_limit)
1.165 djm 195: packet_set_rekey_limit((u_int32_t)options.rekey_limit);
1.22 provos 196:
1.65 markus 197: /* start key exchange */
1.64 markus 198: kex = kex_setup(myproposal);
1.111 markus 199: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 200: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 201: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 202: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 203: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.61 markus 204: kex->client_version_string=client_version_string;
205: kex->server_version_string=server_version_string;
1.75 markus 206: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 207:
208: xxx_kex = kex;
1.22 provos 209:
1.66 markus 210: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.173 andreas 211:
212: if (options.use_roaming && !kex->roaming) {
213: debug("Roaming not allowed by server");
214: options.use_roaming = 0;
215: }
1.62 markus 216:
217: session_id2 = kex->session_id;
218: session_id2_len = kex->session_id_len;
1.22 provos 219:
220: #ifdef DEBUG_KEXDH
221: /* send 1st encrypted/maced/compressed message */
222: packet_start(SSH2_MSG_IGNORE);
223: packet_put_cstring("markus");
224: packet_send();
225: packet_write_wait();
226: #endif
1.1 markus 227: }
1.11 markus 228:
1.1 markus 229: /*
230: * Authenticate user
231: */
1.20 markus 232:
233: typedef struct Authctxt Authctxt;
234: typedef struct Authmethod Authmethod;
1.117 markus 235: typedef struct identity Identity;
236: typedef struct idlist Idlist;
1.20 markus 237:
1.117 markus 238: struct identity {
239: TAILQ_ENTRY(identity) next;
240: AuthenticationConnection *ac; /* set if agent supports key */
241: Key *key; /* public/private key */
242: char *filename; /* comment for agent-only keys */
243: int tried;
244: int isprivate; /* key points to the private key */
1.191 dtucker 245: int userprovided;
1.117 markus 246: };
247: TAILQ_HEAD(idlist, identity);
1.20 markus 248:
249: struct Authctxt {
250: const char *server_user;
1.68 markus 251: const char *local_user;
1.20 markus 252: const char *host;
253: const char *service;
1.23 markus 254: Authmethod *method;
1.183 djm 255: sig_atomic_t success;
1.51 markus 256: char *authlist;
1.68 markus 257: /* pubkey */
1.117 markus 258: Idlist keys;
1.68 markus 259: AuthenticationConnection *agent;
260: /* hostbased */
1.100 markus 261: Sensitive *sensitive;
1.82 markus 262: /* kbd-interactive */
263: int info_req_seen;
1.121 markus 264: /* generic */
265: void *methoddata;
1.20 markus 266: };
267: struct Authmethod {
268: char *name; /* string to compare against server's list */
269: int (*userauth)(Authctxt *authctxt);
1.170 djm 270: void (*cleanup)(Authctxt *authctxt);
1.20 markus 271: int *enabled; /* flag in option struct that enables method */
272: int *batch_flag; /* flag in option struct that disables method */
273: };
274:
1.92 markus 275: void input_userauth_success(int, u_int32_t, void *);
1.172 djm 276: void input_userauth_success_unexpected(int, u_int32_t, void *);
1.92 markus 277: void input_userauth_failure(int, u_int32_t, void *);
278: void input_userauth_banner(int, u_int32_t, void *);
279: void input_userauth_error(int, u_int32_t, void *);
280: void input_userauth_info_req(int, u_int32_t, void *);
281: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 282: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.170 djm 283: void input_userauth_jpake_server_step1(int, u_int32_t, void *);
284: void input_userauth_jpake_server_step2(int, u_int32_t, void *);
285: void input_userauth_jpake_server_confirm(int, u_int32_t, void *);
1.86 itojun 286:
287: int userauth_none(Authctxt *);
288: int userauth_pubkey(Authctxt *);
289: int userauth_passwd(Authctxt *);
290: int userauth_kbdint(Authctxt *);
291: int userauth_hostbased(Authctxt *);
1.170 djm 292: int userauth_jpake(Authctxt *);
293:
294: void userauth_jpake_cleanup(Authctxt *);
1.20 markus 295:
1.121 markus 296: #ifdef GSSAPI
297: int userauth_gssapi(Authctxt *authctxt);
298: void input_gssapi_response(int type, u_int32_t, void *);
299: void input_gssapi_token(int type, u_int32_t, void *);
300: void input_gssapi_hash(int type, u_int32_t, void *);
301: void input_gssapi_error(int, u_int32_t, void *);
302: void input_gssapi_errtok(int, u_int32_t, void *);
303: #endif
304:
1.86 itojun 305: void userauth(Authctxt *, char *);
1.51 markus 306:
1.117 markus 307: static int sign_and_send_pubkey(Authctxt *, Identity *);
308: static void pubkey_prepare(Authctxt *);
309: static void pubkey_cleanup(Authctxt *);
1.191 dtucker 310: static Key *load_identity_file(char *, int);
1.76 itojun 311:
312: static Authmethod *authmethod_get(char *authlist);
313: static Authmethod *authmethod_lookup(const char *name);
314: static char *authmethods_get(void);
1.20 markus 315:
316: Authmethod authmethods[] = {
1.121 markus 317: #ifdef GSSAPI
1.132 markus 318: {"gssapi-with-mic",
1.121 markus 319: userauth_gssapi,
1.170 djm 320: NULL,
1.121 markus 321: &options.gss_authentication,
322: NULL},
323: #endif
1.81 markus 324: {"hostbased",
325: userauth_hostbased,
1.170 djm 326: NULL,
1.81 markus 327: &options.hostbased_authentication,
328: NULL},
1.20 markus 329: {"publickey",
330: userauth_pubkey,
1.170 djm 331: NULL,
1.28 markus 332: &options.pubkey_authentication,
1.20 markus 333: NULL},
1.170 djm 334: #ifdef JPAKE
335: {"jpake-01@openssh.com",
336: userauth_jpake,
337: userauth_jpake_cleanup,
338: &options.zero_knowledge_password_authentication,
339: &options.batch_mode},
340: #endif
1.81 markus 341: {"keyboard-interactive",
342: userauth_kbdint,
1.170 djm 343: NULL,
1.81 markus 344: &options.kbd_interactive_authentication,
345: &options.batch_mode},
1.20 markus 346: {"password",
347: userauth_passwd,
1.170 djm 348: NULL,
1.20 markus 349: &options.password_authentication,
1.23 markus 350: &options.batch_mode},
351: {"none",
352: userauth_none,
353: NULL,
1.170 djm 354: NULL,
1.23 markus 355: NULL},
1.170 djm 356: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 357: };
358:
359: void
1.68 markus 360: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 361: Sensitive *sensitive)
1.20 markus 362: {
363: Authctxt authctxt;
364: int type;
1.39 markus 365:
1.73 markus 366: if (options.challenge_response_authentication)
1.39 markus 367: options.kbd_interactive_authentication = 1;
1.20 markus 368:
369: packet_start(SSH2_MSG_SERVICE_REQUEST);
370: packet_put_cstring("ssh-userauth");
371: packet_send();
1.108 markus 372: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 373: packet_write_wait();
1.91 markus 374: type = packet_read();
1.108 markus 375: if (type != SSH2_MSG_SERVICE_ACCEPT)
376: fatal("Server denied authentication request: %d", type);
1.20 markus 377: if (packet_remaining() > 0) {
1.91 markus 378: char *reply = packet_get_string(NULL);
1.108 markus 379: debug2("service_accept: %s", reply);
1.20 markus 380: xfree(reply);
381: } else {
1.109 markus 382: debug2("buggy server: service_accept w/o service");
1.20 markus 383: }
1.90 markus 384: packet_check_eom();
1.108 markus 385: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 386:
1.53 markus 387: if (options.preferred_authentications == NULL)
388: options.preferred_authentications = authmethods_get();
389:
1.20 markus 390: /* setup authentication context */
1.82 markus 391: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 392: pubkey_prepare(&authctxt);
1.20 markus 393: authctxt.server_user = server_user;
1.68 markus 394: authctxt.local_user = local_user;
1.20 markus 395: authctxt.host = host;
396: authctxt.service = "ssh-connection"; /* service name */
397: authctxt.success = 0;
1.23 markus 398: authctxt.method = authmethod_lookup("none");
1.51 markus 399: authctxt.authlist = NULL;
1.121 markus 400: authctxt.methoddata = NULL;
1.100 markus 401: authctxt.sensitive = sensitive;
1.82 markus 402: authctxt.info_req_seen = 0;
1.23 markus 403: if (authctxt.method == NULL)
404: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 405:
406: /* initial userauth request */
1.23 markus 407: userauth_none(&authctxt);
1.20 markus 408:
1.65 markus 409: dispatch_init(&input_userauth_error);
1.20 markus 410: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
411: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 412: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 413: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
414:
1.117 markus 415: pubkey_cleanup(&authctxt);
1.119 markus 416: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
417:
1.109 markus 418: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 419: }
1.119 markus 420:
1.20 markus 421: void
1.51 markus 422: userauth(Authctxt *authctxt, char *authlist)
423: {
1.170 djm 424: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
425: authctxt->method->cleanup(authctxt);
426:
1.121 markus 427: if (authctxt->methoddata) {
428: xfree(authctxt->methoddata);
429: authctxt->methoddata = NULL;
430: }
1.51 markus 431: if (authlist == NULL) {
432: authlist = authctxt->authlist;
433: } else {
434: if (authctxt->authlist)
435: xfree(authctxt->authlist);
436: authctxt->authlist = authlist;
437: }
438: for (;;) {
439: Authmethod *method = authmethod_get(authlist);
440: if (method == NULL)
441: fatal("Permission denied (%s).", authlist);
442: authctxt->method = method;
1.119 markus 443:
444: /* reset the per method handler */
445: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
446: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
447:
448: /* and try new method */
1.51 markus 449: if (method->userauth(authctxt) != 0) {
450: debug2("we sent a %s packet, wait for reply", method->name);
451: break;
452: } else {
453: debug2("we did not send a packet, disable method");
454: method->enabled = NULL;
455: }
456: }
457: }
1.105 deraadt 458:
1.169 djm 459: /* ARGSUSED */
1.51 markus 460: void
1.92 markus 461: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 462: {
1.35 markus 463: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 464: "type %d", type);
1.35 markus 465: }
1.105 deraadt 466:
1.169 djm 467: /* ARGSUSED */
1.35 markus 468: void
1.92 markus 469: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 470: {
1.166 djm 471: char *msg, *raw, *lang;
472: u_int len;
1.126 deraadt 473:
1.35 markus 474: debug3("input_userauth_banner");
1.166 djm 475: raw = packet_get_string(&len);
1.35 markus 476: lang = packet_get_string(NULL);
1.167 markus 477: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 478: if (len > 65536)
479: len = 65536;
1.168 deraadt 480: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 481: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 482: fprintf(stderr, "%s", msg);
1.166 djm 483: xfree(msg);
484: }
485: xfree(raw);
1.35 markus 486: xfree(lang);
1.20 markus 487: }
1.105 deraadt 488:
1.169 djm 489: /* ARGSUSED */
1.20 markus 490: void
1.92 markus 491: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 492: {
493: Authctxt *authctxt = ctxt;
1.172 djm 494:
1.20 markus 495: if (authctxt == NULL)
496: fatal("input_userauth_success: no authentication context");
1.126 deraadt 497: if (authctxt->authlist) {
1.51 markus 498: xfree(authctxt->authlist);
1.126 deraadt 499: authctxt->authlist = NULL;
500: }
1.172 djm 501: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
502: authctxt->method->cleanup(authctxt);
1.126 deraadt 503: if (authctxt->methoddata) {
1.121 markus 504: xfree(authctxt->methoddata);
1.126 deraadt 505: authctxt->methoddata = NULL;
506: }
1.20 markus 507: authctxt->success = 1; /* break out */
508: }
1.105 deraadt 509:
1.172 djm 510: void
511: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
512: {
513: Authctxt *authctxt = ctxt;
514:
515: if (authctxt == NULL)
516: fatal("%s: no authentication context", __func__);
517:
518: fatal("Unexpected authentication success during %s.",
519: authctxt->method->name);
520: }
521:
1.169 djm 522: /* ARGSUSED */
1.20 markus 523: void
1.92 markus 524: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 525: {
526: Authctxt *authctxt = ctxt;
527: char *authlist = NULL;
528: int partial;
529:
530: if (authctxt == NULL)
531: fatal("input_userauth_failure: no authentication context");
532:
1.23 markus 533: authlist = packet_get_string(NULL);
1.20 markus 534: partial = packet_get_char();
1.90 markus 535: packet_check_eom();
1.20 markus 536:
537: if (partial != 0)
1.116 itojun 538: logit("Authenticated with partial success.");
1.109 markus 539: debug("Authentications that can continue: %s", authlist);
1.20 markus 540:
1.51 markus 541: userauth(authctxt, authlist);
542: }
1.169 djm 543:
544: /* ARGSUSED */
1.51 markus 545: void
1.92 markus 546: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 547: {
548: Authctxt *authctxt = ctxt;
549: Key *key = NULL;
1.117 markus 550: Identity *id = NULL;
1.51 markus 551: Buffer b;
1.96 markus 552: int pktype, sent = 0;
553: u_int alen, blen;
554: char *pkalg, *fp;
555: u_char *pkblob;
1.51 markus 556:
557: if (authctxt == NULL)
558: fatal("input_userauth_pk_ok: no authentication context");
559: if (datafellows & SSH_BUG_PKOK) {
560: /* this is similar to SSH_BUG_PKAUTH */
561: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
562: pkblob = packet_get_string(&blen);
563: buffer_init(&b);
564: buffer_append(&b, pkblob, blen);
565: pkalg = buffer_get_string(&b, &alen);
566: buffer_free(&b);
567: } else {
568: pkalg = packet_get_string(&alen);
569: pkblob = packet_get_string(&blen);
570: }
1.90 markus 571: packet_check_eom();
1.51 markus 572:
1.117 markus 573: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 574:
1.117 markus 575: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
576: debug("unknown pkalg %s", pkalg);
577: goto done;
578: }
579: if ((key = key_from_blob(pkblob, blen)) == NULL) {
580: debug("no key from blob. pkalg %s", pkalg);
581: goto done;
582: }
583: if (key->type != pktype) {
584: error("input_userauth_pk_ok: type mismatch "
585: "for decoded key (received %d, expected %d)",
586: key->type, pktype);
587: goto done;
588: }
589: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
590: debug2("input_userauth_pk_ok: fp %s", fp);
591: xfree(fp);
592:
1.127 markus 593: /*
594: * search keys in the reverse order, because last candidate has been
595: * moved to the end of the queue. this also avoids confusion by
596: * duplicate keys
597: */
1.136 henning 598: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 599: if (key_equal(key, id->key)) {
600: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 601: break;
602: }
1.117 markus 603: }
604: done:
1.51 markus 605: if (key != NULL)
606: key_free(key);
607: xfree(pkalg);
608: xfree(pkblob);
609:
1.106 deraadt 610: /* try another method if we did not send a packet */
1.51 markus 611: if (sent == 0)
612: userauth(authctxt, NULL);
1.20 markus 613: }
1.121 markus 614:
615: #ifdef GSSAPI
1.133 djm 616: int
1.121 markus 617: userauth_gssapi(Authctxt *authctxt)
618: {
619: Gssctxt *gssctxt = NULL;
1.128 avsm 620: static gss_OID_set gss_supported = NULL;
1.139 djm 621: static u_int mech = 0;
1.121 markus 622: OM_uint32 min;
623: int ok = 0;
624:
625: /* Try one GSSAPI method at a time, rather than sending them all at
626: * once. */
627:
1.128 avsm 628: if (gss_supported == NULL)
629: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 630:
631: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 632: while (mech < gss_supported->count && !ok) {
1.121 markus 633: /* My DER encoding requires length<128 */
1.128 avsm 634: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 635: ssh_gssapi_check_mechanism(&gssctxt,
636: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 637: ok = 1; /* Mechanism works */
638: } else {
639: mech++;
640: }
641: }
642:
1.161 djm 643: if (!ok)
1.139 djm 644: return 0;
1.121 markus 645:
646: authctxt->methoddata=(void *)gssctxt;
647:
648: packet_start(SSH2_MSG_USERAUTH_REQUEST);
649: packet_put_cstring(authctxt->server_user);
650: packet_put_cstring(authctxt->service);
651: packet_put_cstring(authctxt->method->name);
652:
653: packet_put_int(1);
654:
1.129 markus 655: packet_put_int((gss_supported->elements[mech].length) + 2);
656: packet_put_char(SSH_GSS_OIDTYPE);
657: packet_put_char(gss_supported->elements[mech].length);
658: packet_put_raw(gss_supported->elements[mech].elements,
659: gss_supported->elements[mech].length);
1.121 markus 660:
661: packet_send();
662:
663: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
664: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
665: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
666: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
667:
668: mech++; /* Move along to next candidate */
669:
670: return 1;
671: }
672:
1.130 markus 673: static OM_uint32
674: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
675: {
676: Authctxt *authctxt = ctxt;
677: Gssctxt *gssctxt = authctxt->methoddata;
678: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 679: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
680: gss_buffer_desc gssbuf;
1.132 markus 681: OM_uint32 status, ms, flags;
682: Buffer b;
1.133 djm 683:
1.130 markus 684: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 685: recv_tok, &send_tok, &flags);
1.130 markus 686:
687: if (send_tok.length > 0) {
688: if (GSS_ERROR(status))
689: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
690: else
691: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 692:
1.130 markus 693: packet_put_string(send_tok.value, send_tok.length);
694: packet_send();
695: gss_release_buffer(&ms, &send_tok);
696: }
1.133 djm 697:
1.130 markus 698: if (status == GSS_S_COMPLETE) {
1.132 markus 699: /* send either complete or MIC, depending on mechanism */
700: if (!(flags & GSS_C_INTEG_FLAG)) {
701: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
702: packet_send();
703: } else {
704: ssh_gssapi_buildmic(&b, authctxt->server_user,
705: authctxt->service, "gssapi-with-mic");
706:
707: gssbuf.value = buffer_ptr(&b);
708: gssbuf.length = buffer_len(&b);
1.133 djm 709:
1.132 markus 710: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 711:
1.132 markus 712: if (!GSS_ERROR(status)) {
713: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
714: packet_put_string(mic.value, mic.length);
1.133 djm 715:
1.132 markus 716: packet_send();
717: }
1.133 djm 718:
1.132 markus 719: buffer_free(&b);
720: gss_release_buffer(&ms, &mic);
1.133 djm 721: }
1.130 markus 722: }
1.133 djm 723:
1.130 markus 724: return status;
725: }
726:
1.169 djm 727: /* ARGSUSED */
1.121 markus 728: void
729: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
730: {
731: Authctxt *authctxt = ctxt;
732: Gssctxt *gssctxt;
733: int oidlen;
734: char *oidv;
735:
736: if (authctxt == NULL)
737: fatal("input_gssapi_response: no authentication context");
738: gssctxt = authctxt->methoddata;
739:
740: /* Setup our OID */
741: oidv = packet_get_string(&oidlen);
742:
1.129 markus 743: if (oidlen <= 2 ||
744: oidv[0] != SSH_GSS_OIDTYPE ||
745: oidv[1] != oidlen - 2) {
1.130 markus 746: xfree(oidv);
1.129 markus 747: debug("Badly encoded mechanism OID received");
748: userauth(authctxt, NULL);
749: return;
1.121 markus 750: }
1.129 markus 751:
752: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
753: fatal("Server returned different OID than expected");
1.121 markus 754:
755: packet_check_eom();
756:
757: xfree(oidv);
758:
1.130 markus 759: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 760: /* Start again with next method on list */
761: debug("Trying to start again");
762: userauth(authctxt, NULL);
763: return;
764: }
765: }
766:
1.169 djm 767: /* ARGSUSED */
1.121 markus 768: void
769: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
770: {
771: Authctxt *authctxt = ctxt;
772: gss_buffer_desc recv_tok;
1.130 markus 773: OM_uint32 status;
1.121 markus 774: u_int slen;
775:
776: if (authctxt == NULL)
777: fatal("input_gssapi_response: no authentication context");
778:
779: recv_tok.value = packet_get_string(&slen);
780: recv_tok.length = slen; /* safe typecast */
781:
782: packet_check_eom();
783:
1.130 markus 784: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 785:
786: xfree(recv_tok.value);
787:
788: if (GSS_ERROR(status)) {
789: /* Start again with the next method in the list */
790: userauth(authctxt, NULL);
791: return;
792: }
793: }
794:
1.169 djm 795: /* ARGSUSED */
1.121 markus 796: void
797: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
798: {
799: Authctxt *authctxt = ctxt;
800: Gssctxt *gssctxt;
801: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
802: gss_buffer_desc recv_tok;
803: OM_uint32 status, ms;
1.123 deraadt 804: u_int len;
1.121 markus 805:
806: if (authctxt == NULL)
807: fatal("input_gssapi_response: no authentication context");
808: gssctxt = authctxt->methoddata;
809:
1.123 deraadt 810: recv_tok.value = packet_get_string(&len);
811: recv_tok.length = len;
1.121 markus 812:
813: packet_check_eom();
814:
815: /* Stick it into GSSAPI and see what it says */
816: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 817: &recv_tok, &send_tok, NULL);
1.121 markus 818:
819: xfree(recv_tok.value);
820: gss_release_buffer(&ms, &send_tok);
821:
822: /* Server will be returning a failed packet after this one */
823: }
824:
1.169 djm 825: /* ARGSUSED */
1.121 markus 826: void
827: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
828: {
829: OM_uint32 maj, min;
830: char *msg;
831: char *lang;
832:
833: maj=packet_get_int();
834: min=packet_get_int();
835: msg=packet_get_string(NULL);
836: lang=packet_get_string(NULL);
837:
838: packet_check_eom();
839:
1.143 stevesk 840: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 841: xfree(msg);
842: xfree(lang);
843: }
844: #endif /* GSSAPI */
1.20 markus 845:
1.1 markus 846: int
1.23 markus 847: userauth_none(Authctxt *authctxt)
848: {
849: /* initial userauth request */
850: packet_start(SSH2_MSG_USERAUTH_REQUEST);
851: packet_put_cstring(authctxt->server_user);
852: packet_put_cstring(authctxt->service);
853: packet_put_cstring(authctxt->method->name);
854: packet_send();
855: return 1;
856: }
857:
858: int
1.20 markus 859: userauth_passwd(Authctxt *authctxt)
1.1 markus 860: {
1.6 markus 861: static int attempt = 0;
1.99 markus 862: char prompt[150];
1.1 markus 863: char *password;
1.175 dtucker 864: const char *host = options.host_key_alias ? options.host_key_alias :
865: authctxt->host;
1.6 markus 866:
1.13 todd 867: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 868: return 0;
1.13 todd 869:
1.87 deraadt 870: if (attempt != 1)
1.13 todd 871: error("Permission denied, please try again.");
1.1 markus 872:
1.43 itojun 873: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 874: authctxt->server_user, host);
1.1 markus 875: password = read_passphrase(prompt, 0);
876: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 877: packet_put_cstring(authctxt->server_user);
878: packet_put_cstring(authctxt->service);
1.23 markus 879: packet_put_cstring(authctxt->method->name);
1.1 markus 880: packet_put_char(0);
1.49 markus 881: packet_put_cstring(password);
1.1 markus 882: memset(password, 0, strlen(password));
883: xfree(password);
1.85 markus 884: packet_add_padding(64);
1.1 markus 885: packet_send();
1.99 markus 886:
1.104 deraadt 887: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 888: &input_userauth_passwd_changereq);
889:
1.1 markus 890: return 1;
891: }
1.169 djm 892:
1.99 markus 893: /*
894: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
895: */
1.169 djm 896: /* ARGSUSED */
1.99 markus 897: void
1.153 djm 898: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 899: {
900: Authctxt *authctxt = ctxt;
901: char *info, *lang, *password = NULL, *retype = NULL;
902: char prompt[150];
1.175 dtucker 903: const char *host = options.host_key_alias ? options.host_key_alias :
904: authctxt->host;
1.99 markus 905:
906: debug2("input_userauth_passwd_changereq");
907:
908: if (authctxt == NULL)
909: fatal("input_userauth_passwd_changereq: "
910: "no authentication context");
911:
912: info = packet_get_string(NULL);
913: lang = packet_get_string(NULL);
914: if (strlen(info) > 0)
1.116 itojun 915: logit("%s", info);
1.99 markus 916: xfree(info);
917: xfree(lang);
918: packet_start(SSH2_MSG_USERAUTH_REQUEST);
919: packet_put_cstring(authctxt->server_user);
920: packet_put_cstring(authctxt->service);
921: packet_put_cstring(authctxt->method->name);
922: packet_put_char(1); /* additional info */
1.104 deraadt 923: snprintf(prompt, sizeof(prompt),
1.99 markus 924: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 925: authctxt->server_user, host);
1.99 markus 926: password = read_passphrase(prompt, 0);
927: packet_put_cstring(password);
928: memset(password, 0, strlen(password));
929: xfree(password);
930: password = NULL;
931: while (password == NULL) {
1.104 deraadt 932: snprintf(prompt, sizeof(prompt),
1.99 markus 933: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 934: authctxt->server_user, host);
1.99 markus 935: password = read_passphrase(prompt, RP_ALLOW_EOF);
936: if (password == NULL) {
937: /* bail out */
938: return;
939: }
1.104 deraadt 940: snprintf(prompt, sizeof(prompt),
1.99 markus 941: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 942: authctxt->server_user, host);
1.99 markus 943: retype = read_passphrase(prompt, 0);
944: if (strcmp(password, retype) != 0) {
945: memset(password, 0, strlen(password));
946: xfree(password);
1.116 itojun 947: logit("Mismatch; try again, EOF to quit.");
1.99 markus 948: password = NULL;
949: }
950: memset(retype, 0, strlen(retype));
951: xfree(retype);
952: }
953: packet_put_cstring(password);
954: memset(password, 0, strlen(password));
955: xfree(password);
956: packet_add_padding(64);
957: packet_send();
1.104 deraadt 958:
959: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 960: &input_userauth_passwd_changereq);
1.117 markus 961: }
962:
1.170 djm 963: #ifdef JPAKE
964: static char *
965: pw_encrypt(const char *password, const char *crypt_scheme, const char *salt)
966: {
967: /* OpenBSD crypt(3) handles all of these */
968: if (strcmp(crypt_scheme, "crypt") == 0 ||
969: strcmp(crypt_scheme, "bcrypt") == 0 ||
970: strcmp(crypt_scheme, "md5crypt") == 0 ||
971: strcmp(crypt_scheme, "crypt-extended") == 0)
972: return xstrdup(crypt(password, salt));
973: error("%s: unsupported password encryption scheme \"%.100s\"",
974: __func__, crypt_scheme);
975: return NULL;
976: }
977:
978: static BIGNUM *
979: jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
980: const char *salt)
981: {
982: char prompt[256], *password, *crypted;
983: u_char *secret;
984: u_int secret_len;
985: BIGNUM *ret;
986:
987: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
988: authctxt->server_user, authctxt->host);
989: password = read_passphrase(prompt, 0);
990:
991: if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
992: logit("Disabling %s authentication", authctxt->method->name);
993: authctxt->method->enabled = NULL;
994: /* Continue with an empty password to fail gracefully */
995: crypted = xstrdup("");
996: }
997:
998: #ifdef JPAKE_DEBUG
999: debug3("%s: salt = %s", __func__, salt);
1000: debug3("%s: scheme = %s", __func__, crypt_scheme);
1001: debug3("%s: crypted = %s", __func__, crypted);
1002: #endif
1003:
1004: if (hash_buffer(crypted, strlen(crypted), EVP_sha256(),
1005: &secret, &secret_len) != 0)
1006: fatal("%s: hash_buffer", __func__);
1007:
1008: bzero(password, strlen(password));
1009: bzero(crypted, strlen(crypted));
1010: xfree(password);
1011: xfree(crypted);
1012:
1013: if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL)
1014: fatal("%s: BN_bin2bn (secret)", __func__);
1015: bzero(secret, secret_len);
1016: xfree(secret);
1017:
1018: return ret;
1019: }
1020:
1021: /* ARGSUSED */
1022: void
1023: input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt)
1024: {
1025: Authctxt *authctxt = ctxt;
1026: struct jpake_ctx *pctx = authctxt->methoddata;
1027: u_char *x3_proof, *x4_proof, *x2_s_proof;
1028: u_int x3_proof_len, x4_proof_len, x2_s_proof_len;
1029: char *crypt_scheme, *salt;
1030:
1031: /* Disable this message */
1032: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1, NULL);
1033:
1034: if ((pctx->g_x3 = BN_new()) == NULL ||
1035: (pctx->g_x4 = BN_new()) == NULL)
1036: fatal("%s: BN_new", __func__);
1037:
1038: /* Fetch step 1 values */
1039: crypt_scheme = packet_get_string(NULL);
1040: salt = packet_get_string(NULL);
1041: pctx->server_id = packet_get_string(&pctx->server_id_len);
1042: packet_get_bignum2(pctx->g_x3);
1043: packet_get_bignum2(pctx->g_x4);
1044: x3_proof = packet_get_string(&x3_proof_len);
1045: x4_proof = packet_get_string(&x4_proof_len);
1046: packet_check_eom();
1047:
1048: JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__));
1049:
1050: /* Obtain password and derive secret */
1051: pctx->s = jpake_password_to_secret(authctxt, crypt_scheme, salt);
1052: bzero(crypt_scheme, strlen(crypt_scheme));
1053: bzero(salt, strlen(salt));
1054: xfree(crypt_scheme);
1055: xfree(salt);
1056: JPAKE_DEBUG_BN((pctx->s, "%s: s = ", __func__));
1057:
1058: /* Calculate step 2 values */
1059: jpake_step2(pctx->grp, pctx->s, pctx->g_x1,
1060: pctx->g_x3, pctx->g_x4, pctx->x2,
1061: pctx->server_id, pctx->server_id_len,
1062: pctx->client_id, pctx->client_id_len,
1063: x3_proof, x3_proof_len,
1064: x4_proof, x4_proof_len,
1065: &pctx->a,
1066: &x2_s_proof, &x2_s_proof_len);
1067:
1068: bzero(x3_proof, x3_proof_len);
1069: bzero(x4_proof, x4_proof_len);
1070: xfree(x3_proof);
1071: xfree(x4_proof);
1072:
1073: JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__));
1074:
1075: /* Send values for step 2 */
1076: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2);
1077: packet_put_bignum2(pctx->a);
1078: packet_put_string(x2_s_proof, x2_s_proof_len);
1079: packet_send();
1080:
1081: bzero(x2_s_proof, x2_s_proof_len);
1082: xfree(x2_s_proof);
1083:
1084: /* Expect step 2 packet from peer */
1085: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2,
1086: input_userauth_jpake_server_step2);
1087: }
1088:
1089: /* ARGSUSED */
1090: void
1091: input_userauth_jpake_server_step2(int type, u_int32_t seq, void *ctxt)
1092: {
1093: Authctxt *authctxt = ctxt;
1094: struct jpake_ctx *pctx = authctxt->methoddata;
1095: u_char *x4_s_proof;
1096: u_int x4_s_proof_len;
1097:
1098: /* Disable this message */
1099: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL);
1100:
1101: if ((pctx->b = BN_new()) == NULL)
1102: fatal("%s: BN_new", __func__);
1103:
1104: /* Fetch step 2 values */
1105: packet_get_bignum2(pctx->b);
1106: x4_s_proof = packet_get_string(&x4_s_proof_len);
1107: packet_check_eom();
1108:
1109: JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__));
1110:
1111: /* Derive shared key and calculate confirmation hash */
1112: jpake_key_confirm(pctx->grp, pctx->s, pctx->b,
1113: pctx->x2, pctx->g_x1, pctx->g_x2, pctx->g_x3, pctx->g_x4,
1114: pctx->client_id, pctx->client_id_len,
1115: pctx->server_id, pctx->server_id_len,
1116: session_id2, session_id2_len,
1117: x4_s_proof, x4_s_proof_len,
1118: &pctx->k,
1119: &pctx->h_k_cid_sessid, &pctx->h_k_cid_sessid_len);
1120:
1121: bzero(x4_s_proof, x4_s_proof_len);
1122: xfree(x4_s_proof);
1123:
1124: JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__));
1125:
1126: /* Send key confirmation proof */
1127: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM);
1128: packet_put_string(pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len);
1129: packet_send();
1130:
1131: /* Expect confirmation from peer */
1132: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM,
1133: input_userauth_jpake_server_confirm);
1134: }
1135:
1136: /* ARGSUSED */
1137: void
1138: input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt)
1139: {
1140: Authctxt *authctxt = ctxt;
1141: struct jpake_ctx *pctx = authctxt->methoddata;
1142:
1143: /* Disable this message */
1144: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL);
1145:
1146: pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len);
1147: packet_check_eom();
1148:
1149: JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__));
1150:
1151: /* Verify expected confirmation hash */
1152: if (jpake_check_confirm(pctx->k,
1153: pctx->server_id, pctx->server_id_len,
1154: session_id2, session_id2_len,
1155: pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len) == 1)
1156: debug("%s: %s success", __func__, authctxt->method->name);
1157: else {
1158: debug("%s: confirmation mismatch", __func__);
1159: /* XXX stash this so if auth succeeds then we can warn/kill */
1160: }
1161:
1162: userauth_jpake_cleanup(authctxt);
1163: }
1164: #endif /* JPAKE */
1165:
1.117 markus 1166: static int
1167: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
1168: u_char *data, u_int datalen)
1169: {
1170: Key *prv;
1171: int ret;
1.99 markus 1172:
1.117 markus 1173: /* the agent supports this key */
1174: if (id->ac)
1175: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
1176: data, datalen));
1177: /*
1178: * we have already loaded the private key or
1179: * the private key is stored in external hardware
1180: */
1181: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
1182: return (key_sign(id->key, sigp, lenp, data, datalen));
1183: /* load the private key from the file */
1.191 dtucker 1184: if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
1.117 markus 1185: return (-1);
1186: ret = key_sign(prv, sigp, lenp, data, datalen);
1187: key_free(prv);
1188: return (ret);
1.51 markus 1189: }
1190:
1.76 itojun 1191: static int
1.117 markus 1192: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1193: {
1194: Buffer b;
1.32 markus 1195: u_char *blob, *signature;
1.96 markus 1196: u_int bloblen, slen;
1.120 markus 1197: u_int skip = 0;
1.17 markus 1198: int ret = -1;
1.23 markus 1199: int have_sig = 1;
1.182 djm 1200: char *fp;
1.1 markus 1201:
1.182 djm 1202: fp = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
1203: debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1204: xfree(fp);
1.51 markus 1205:
1.117 markus 1206: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1207: /* we cannot handle this key */
1.30 markus 1208: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1209: return 0;
1210: }
1.1 markus 1211: /* data to be signed */
1212: buffer_init(&b);
1.26 markus 1213: if (datafellows & SSH_OLD_SESSIONID) {
1214: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1215: skip = session_id2_len;
1.26 markus 1216: } else {
1.14 markus 1217: buffer_put_string(&b, session_id2, session_id2_len);
1218: skip = buffer_len(&b);
1219: }
1.1 markus 1220: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1221: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1222: buffer_put_cstring(&b,
1.30 markus 1223: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1224: "ssh-userauth" :
1.20 markus 1225: authctxt->service);
1.30 markus 1226: if (datafellows & SSH_BUG_PKAUTH) {
1227: buffer_put_char(&b, have_sig);
1228: } else {
1229: buffer_put_cstring(&b, authctxt->method->name);
1230: buffer_put_char(&b, have_sig);
1.117 markus 1231: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1232: }
1.1 markus 1233: buffer_put_string(&b, blob, bloblen);
1234:
1235: /* generate signature */
1.117 markus 1236: ret = identity_sign(id, &signature, &slen,
1.51 markus 1237: buffer_ptr(&b), buffer_len(&b));
1.17 markus 1238: if (ret == -1) {
1239: xfree(blob);
1240: buffer_free(&b);
1241: return 0;
1242: }
1.28 markus 1243: #ifdef DEBUG_PK
1.1 markus 1244: buffer_dump(&b);
1245: #endif
1.30 markus 1246: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1247: buffer_clear(&b);
1248: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1249: skip = session_id2_len;
1.10 markus 1250: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1251: buffer_put_cstring(&b, authctxt->server_user);
1252: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1253: buffer_put_cstring(&b, authctxt->method->name);
1254: buffer_put_char(&b, have_sig);
1.30 markus 1255: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1256: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1257: buffer_put_string(&b, blob, bloblen);
1258: }
1259: xfree(blob);
1.51 markus 1260:
1.1 markus 1261: /* append signature */
1262: buffer_put_string(&b, signature, slen);
1263: xfree(signature);
1264:
1265: /* skip session id and packet type */
1.14 markus 1266: if (buffer_len(&b) < skip + 1)
1.20 markus 1267: fatal("userauth_pubkey: internal error");
1.14 markus 1268: buffer_consume(&b, skip + 1);
1.1 markus 1269:
1270: /* put remaining data from buffer into packet */
1271: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1272: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1273: buffer_free(&b);
1274: packet_send();
1.17 markus 1275:
1276: return 1;
1.16 markus 1277: }
1278:
1.76 itojun 1279: static int
1.117 markus 1280: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1281: {
1.51 markus 1282: u_char *blob;
1.97 markus 1283: u_int bloblen, have_sig = 0;
1.20 markus 1284:
1.51 markus 1285: debug3("send_pubkey_test");
1.16 markus 1286:
1.117 markus 1287: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1288: /* we cannot handle this key */
1289: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1290: return 0;
1291: }
1.51 markus 1292: /* register callback for USERAUTH_PK_OK message */
1293: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1294:
1295: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1296: packet_put_cstring(authctxt->server_user);
1297: packet_put_cstring(authctxt->service);
1298: packet_put_cstring(authctxt->method->name);
1299: packet_put_char(have_sig);
1300: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1301: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1302: packet_put_string(blob, bloblen);
1303: xfree(blob);
1304: packet_send();
1305: return 1;
1306: }
1307:
1.76 itojun 1308: static Key *
1.191 dtucker 1309: load_identity_file(char *filename, int userprovided)
1.51 markus 1310: {
1311: Key *private;
1312: char prompt[300], *passphrase;
1.178 dtucker 1313: int perm_ok = 0, quit, i;
1.52 markus 1314: struct stat st;
1.16 markus 1315:
1.52 markus 1316: if (stat(filename, &st) < 0) {
1.191 dtucker 1317: (userprovided ? logit : debug3)("no such identity: %s: %s",
1318: filename, strerror(errno));
1.52 markus 1319: return NULL;
1320: }
1.152 dtucker 1321: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
1322: if (!perm_ok)
1323: return NULL;
1.56 markus 1324: if (private == NULL) {
1325: if (options.batch_mode)
1.51 markus 1326: return NULL;
1.16 markus 1327: snprintf(prompt, sizeof prompt,
1.88 deraadt 1328: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 1329: for (i = 0; i < options.number_of_password_prompts; i++) {
1330: passphrase = read_passphrase(prompt, 0);
1331: if (strcmp(passphrase, "") != 0) {
1.152 dtucker 1332: private = key_load_private_type(KEY_UNSPEC,
1333: filename, passphrase, NULL, NULL);
1.51 markus 1334: quit = 0;
1.20 markus 1335: } else {
1336: debug2("no passphrase given, try next key");
1.51 markus 1337: quit = 1;
1.20 markus 1338: }
1339: memset(passphrase, 0, strlen(passphrase));
1340: xfree(passphrase);
1.56 markus 1341: if (private != NULL || quit)
1.20 markus 1342: break;
1343: debug2("bad passphrase given, try again...");
1.16 markus 1344: }
1345: }
1.51 markus 1346: return private;
1347: }
1348:
1.117 markus 1349: /*
1350: * try keys in the following order:
1351: * 1. agent keys that are found in the config file
1352: * 2. other agent keys
1353: * 3. keys that are only listed in the config file
1354: */
1355: static void
1356: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1357: {
1.190 djm 1358: Identity *id, *id2, *tmp;
1.117 markus 1359: Idlist agent, files, *preferred;
1360: Key *key;
1361: AuthenticationConnection *ac;
1362: char *comment;
1363: int i, found;
1.51 markus 1364:
1.117 markus 1365: TAILQ_INIT(&agent); /* keys from the agent */
1366: TAILQ_INIT(&files); /* keys from the config file */
1367: preferred = &authctxt->keys;
1368: TAILQ_INIT(preferred); /* preferred order of keys */
1369:
1.190 djm 1370: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1371: for (i = 0; i < options.num_identity_files; i++) {
1372: key = options.identity_keys[i];
1373: if (key && key->type == KEY_RSA1)
1.180 djm 1374: continue;
1375: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1376: continue;
1377: options.identity_keys[i] = NULL;
1.150 djm 1378: id = xcalloc(1, sizeof(*id));
1.117 markus 1379: id->key = key;
1380: id->filename = xstrdup(options.identity_files[i]);
1.192 ! dtucker 1381: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1382: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1383: }
1384: /* Prefer PKCS11 keys that are explicitly listed */
1385: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1386: if (id->key == NULL || (id->key->flags & KEY_FLAG_EXT) == 0)
1387: continue;
1388: found = 0;
1389: TAILQ_FOREACH(id2, &files, next) {
1390: if (id2->key == NULL ||
1391: (id2->key->flags & KEY_FLAG_EXT) != 0)
1392: continue;
1393: if (key_equal(id->key, id2->key)) {
1394: TAILQ_REMOVE(&files, id, next);
1395: TAILQ_INSERT_TAIL(preferred, id, next);
1396: found = 1;
1397: break;
1398: }
1399: }
1400: /* If IdentitiesOnly set and key not found then don't use it */
1401: if (!found && options.identities_only) {
1402: TAILQ_REMOVE(&files, id, next);
1403: bzero(id, sizeof(id));
1404: free(id);
1405: }
1.117 markus 1406: }
1407: /* list of keys supported by the agent */
1408: if ((ac = ssh_get_authentication_connection())) {
1409: for (key = ssh_get_first_identity(ac, &comment, 2);
1410: key != NULL;
1411: key = ssh_get_next_identity(ac, &comment, 2)) {
1412: found = 0;
1413: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1414: /* agent keys from the config file are preferred */
1.117 markus 1415: if (key_equal(key, id->key)) {
1416: key_free(key);
1417: xfree(comment);
1418: TAILQ_REMOVE(&files, id, next);
1419: TAILQ_INSERT_TAIL(preferred, id, next);
1420: id->ac = ac;
1421: found = 1;
1422: break;
1423: }
1424: }
1.135 markus 1425: if (!found && !options.identities_only) {
1.150 djm 1426: id = xcalloc(1, sizeof(*id));
1.117 markus 1427: id->key = key;
1428: id->filename = comment;
1429: id->ac = ac;
1430: TAILQ_INSERT_TAIL(&agent, id, next);
1431: }
1432: }
1433: /* append remaining agent keys */
1434: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1435: TAILQ_REMOVE(&agent, id, next);
1436: TAILQ_INSERT_TAIL(preferred, id, next);
1437: }
1438: authctxt->agent = ac;
1439: }
1440: /* append remaining keys from the config file */
1441: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1442: TAILQ_REMOVE(&files, id, next);
1443: TAILQ_INSERT_TAIL(preferred, id, next);
1444: }
1445: TAILQ_FOREACH(id, preferred, next) {
1.191 dtucker 1446: debug2("key: %s (%p),%s", id->filename, id->key,
1447: id->userprovided ? " explicit" : "");
1.117 markus 1448: }
1.17 markus 1449: }
1450:
1.117 markus 1451: static void
1452: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1453: {
1.117 markus 1454: Identity *id;
1.51 markus 1455:
1.117 markus 1456: if (authctxt->agent != NULL)
1457: ssh_close_authentication_connection(authctxt->agent);
1458: for (id = TAILQ_FIRST(&authctxt->keys); id;
1459: id = TAILQ_FIRST(&authctxt->keys)) {
1460: TAILQ_REMOVE(&authctxt->keys, id, next);
1461: if (id->key)
1462: key_free(id->key);
1463: if (id->filename)
1464: xfree(id->filename);
1465: xfree(id);
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);
1.46 markus 1563: xfree(name);
1.23 markus 1564: xfree(inst);
1.46 markus 1565: xfree(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));
1586: xfree(response);
1587: xfree(prompt);
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);
1.148 djm 1707: xfree(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);
1.112 markus 1712: xfree(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");
1741: xfree(chost);
1742: xfree(pkalg);
1.148 djm 1743: xfree(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);
1756: xfree(signature);
1757: xfree(chost);
1758: xfree(pkalg);
1.148 djm 1759: xfree(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);
1814: xfree(x1_proof);
1815: xfree(x2_proof);
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);
1892: if (supported != NULL)
1893: xfree(supported);
1894: supported = xstrdup(authlist);
1895: preferred = options.preferred_authentications;
1896: debug3("preferred %s", preferred);
1897: current = NULL;
1898: } else if (current != NULL && authmethod_is_enabled(current))
1899: return current;
1.20 markus 1900:
1.53 markus 1901: for (;;) {
1902: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1903: debug("No more authentication methods to try.");
1.53 markus 1904: current = NULL;
1905: return NULL;
1906: }
1907: preferred += next;
1.23 markus 1908: debug3("authmethod_lookup %s", name);
1.53 markus 1909: debug3("remaining preferred: %s", preferred);
1910: if ((current = authmethod_lookup(name)) != NULL &&
1911: authmethod_is_enabled(current)) {
1.23 markus 1912: debug3("authmethod_is_enabled %s", name);
1.109 markus 1913: debug("Next authentication method: %s", name);
1.187 djm 1914: xfree(name);
1.53 markus 1915: return current;
1.23 markus 1916: }
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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