Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.196
1.196 ! dtucker 1: /* $OpenBSD: sshconnect2.c,v 1.195 2013/05/10 03:40:07 djm 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:
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;
1.61 markus 205: kex->client_version_string=client_version_string;
206: kex->server_version_string=server_version_string;
1.75 markus 207: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 208:
209: xxx_kex = kex;
1.22 provos 210:
1.66 markus 211: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.173 andreas 212:
213: if (options.use_roaming && !kex->roaming) {
214: debug("Roaming not allowed by server");
215: options.use_roaming = 0;
216: }
1.62 markus 217:
218: session_id2 = kex->session_id;
219: session_id2_len = kex->session_id_len;
1.22 provos 220:
221: #ifdef DEBUG_KEXDH
222: /* send 1st encrypted/maced/compressed message */
223: packet_start(SSH2_MSG_IGNORE);
224: packet_put_cstring("markus");
225: packet_send();
226: packet_write_wait();
227: #endif
1.1 markus 228: }
1.11 markus 229:
1.1 markus 230: /*
231: * Authenticate user
232: */
1.20 markus 233:
234: typedef struct Authctxt Authctxt;
235: typedef struct Authmethod Authmethod;
1.117 markus 236: typedef struct identity Identity;
237: typedef struct idlist Idlist;
1.20 markus 238:
1.117 markus 239: struct identity {
240: TAILQ_ENTRY(identity) next;
241: AuthenticationConnection *ac; /* set if agent supports key */
242: Key *key; /* public/private key */
243: char *filename; /* comment for agent-only keys */
244: int tried;
245: int isprivate; /* key points to the private key */
1.191 dtucker 246: int userprovided;
1.117 markus 247: };
248: TAILQ_HEAD(idlist, identity);
1.20 markus 249:
250: struct Authctxt {
251: const char *server_user;
1.68 markus 252: const char *local_user;
1.20 markus 253: const char *host;
254: const char *service;
1.23 markus 255: Authmethod *method;
1.183 djm 256: sig_atomic_t success;
1.51 markus 257: char *authlist;
1.68 markus 258: /* pubkey */
1.117 markus 259: Idlist keys;
1.68 markus 260: AuthenticationConnection *agent;
261: /* hostbased */
1.100 markus 262: Sensitive *sensitive;
1.82 markus 263: /* kbd-interactive */
264: int info_req_seen;
1.121 markus 265: /* generic */
266: void *methoddata;
1.20 markus 267: };
268: struct Authmethod {
269: char *name; /* string to compare against server's list */
270: int (*userauth)(Authctxt *authctxt);
1.170 djm 271: void (*cleanup)(Authctxt *authctxt);
1.20 markus 272: int *enabled; /* flag in option struct that enables method */
273: int *batch_flag; /* flag in option struct that disables method */
274: };
275:
1.92 markus 276: void input_userauth_success(int, u_int32_t, void *);
1.172 djm 277: void input_userauth_success_unexpected(int, u_int32_t, void *);
1.92 markus 278: void input_userauth_failure(int, u_int32_t, void *);
279: void input_userauth_banner(int, u_int32_t, void *);
280: void input_userauth_error(int, u_int32_t, void *);
281: void input_userauth_info_req(int, u_int32_t, void *);
282: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 283: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.170 djm 284: void input_userauth_jpake_server_step1(int, u_int32_t, void *);
285: void input_userauth_jpake_server_step2(int, u_int32_t, void *);
286: void input_userauth_jpake_server_confirm(int, u_int32_t, void *);
1.86 itojun 287:
288: int userauth_none(Authctxt *);
289: int userauth_pubkey(Authctxt *);
290: int userauth_passwd(Authctxt *);
291: int userauth_kbdint(Authctxt *);
292: int userauth_hostbased(Authctxt *);
1.170 djm 293: int userauth_jpake(Authctxt *);
294:
295: void userauth_jpake_cleanup(Authctxt *);
1.20 markus 296:
1.121 markus 297: #ifdef GSSAPI
298: int userauth_gssapi(Authctxt *authctxt);
299: void input_gssapi_response(int type, u_int32_t, void *);
300: void input_gssapi_token(int type, u_int32_t, void *);
301: void input_gssapi_hash(int type, u_int32_t, void *);
302: void input_gssapi_error(int, u_int32_t, void *);
303: void input_gssapi_errtok(int, u_int32_t, void *);
304: #endif
305:
1.86 itojun 306: void userauth(Authctxt *, char *);
1.51 markus 307:
1.117 markus 308: static int sign_and_send_pubkey(Authctxt *, Identity *);
309: static void pubkey_prepare(Authctxt *);
310: static void pubkey_cleanup(Authctxt *);
1.191 dtucker 311: static Key *load_identity_file(char *, int);
1.76 itojun 312:
313: static Authmethod *authmethod_get(char *authlist);
314: static Authmethod *authmethod_lookup(const char *name);
315: static char *authmethods_get(void);
1.20 markus 316:
317: Authmethod authmethods[] = {
1.121 markus 318: #ifdef GSSAPI
1.132 markus 319: {"gssapi-with-mic",
1.121 markus 320: userauth_gssapi,
1.170 djm 321: NULL,
1.121 markus 322: &options.gss_authentication,
323: NULL},
324: #endif
1.81 markus 325: {"hostbased",
326: userauth_hostbased,
1.170 djm 327: NULL,
1.81 markus 328: &options.hostbased_authentication,
329: NULL},
1.20 markus 330: {"publickey",
331: userauth_pubkey,
1.170 djm 332: NULL,
1.28 markus 333: &options.pubkey_authentication,
1.20 markus 334: NULL},
1.170 djm 335: #ifdef JPAKE
336: {"jpake-01@openssh.com",
337: userauth_jpake,
338: userauth_jpake_cleanup,
339: &options.zero_knowledge_password_authentication,
340: &options.batch_mode},
341: #endif
1.81 markus 342: {"keyboard-interactive",
343: userauth_kbdint,
1.170 djm 344: NULL,
1.81 markus 345: &options.kbd_interactive_authentication,
346: &options.batch_mode},
1.20 markus 347: {"password",
348: userauth_passwd,
1.170 djm 349: NULL,
1.20 markus 350: &options.password_authentication,
1.23 markus 351: &options.batch_mode},
352: {"none",
353: userauth_none,
354: NULL,
1.170 djm 355: NULL,
1.23 markus 356: NULL},
1.170 djm 357: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 358: };
359:
360: void
1.68 markus 361: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 362: Sensitive *sensitive)
1.20 markus 363: {
364: Authctxt authctxt;
365: int type;
1.39 markus 366:
1.73 markus 367: if (options.challenge_response_authentication)
1.39 markus 368: options.kbd_interactive_authentication = 1;
1.20 markus 369:
370: packet_start(SSH2_MSG_SERVICE_REQUEST);
371: packet_put_cstring("ssh-userauth");
372: packet_send();
1.108 markus 373: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 374: packet_write_wait();
1.91 markus 375: type = packet_read();
1.108 markus 376: if (type != SSH2_MSG_SERVICE_ACCEPT)
377: fatal("Server denied authentication request: %d", type);
1.20 markus 378: if (packet_remaining() > 0) {
1.91 markus 379: char *reply = packet_get_string(NULL);
1.108 markus 380: debug2("service_accept: %s", reply);
1.20 markus 381: xfree(reply);
382: } else {
1.109 markus 383: debug2("buggy server: service_accept w/o service");
1.20 markus 384: }
1.90 markus 385: packet_check_eom();
1.108 markus 386: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 387:
1.53 markus 388: if (options.preferred_authentications == NULL)
389: options.preferred_authentications = authmethods_get();
390:
1.20 markus 391: /* setup authentication context */
1.82 markus 392: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 393: pubkey_prepare(&authctxt);
1.20 markus 394: authctxt.server_user = server_user;
1.68 markus 395: authctxt.local_user = local_user;
1.20 markus 396: authctxt.host = host;
397: authctxt.service = "ssh-connection"; /* service name */
398: authctxt.success = 0;
1.23 markus 399: authctxt.method = authmethod_lookup("none");
1.51 markus 400: authctxt.authlist = NULL;
1.121 markus 401: authctxt.methoddata = NULL;
1.100 markus 402: authctxt.sensitive = sensitive;
1.82 markus 403: authctxt.info_req_seen = 0;
1.23 markus 404: if (authctxt.method == NULL)
405: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 406:
407: /* initial userauth request */
1.23 markus 408: userauth_none(&authctxt);
1.20 markus 409:
1.65 markus 410: dispatch_init(&input_userauth_error);
1.20 markus 411: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
412: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 413: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 414: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
415:
1.117 markus 416: pubkey_cleanup(&authctxt);
1.119 markus 417: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
418:
1.109 markus 419: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 420: }
1.119 markus 421:
1.20 markus 422: void
1.51 markus 423: userauth(Authctxt *authctxt, char *authlist)
424: {
1.170 djm 425: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
426: authctxt->method->cleanup(authctxt);
427:
1.121 markus 428: if (authctxt->methoddata) {
429: xfree(authctxt->methoddata);
430: authctxt->methoddata = NULL;
431: }
1.51 markus 432: if (authlist == NULL) {
433: authlist = authctxt->authlist;
434: } else {
435: if (authctxt->authlist)
436: xfree(authctxt->authlist);
437: authctxt->authlist = authlist;
438: }
439: for (;;) {
440: Authmethod *method = authmethod_get(authlist);
441: if (method == NULL)
442: fatal("Permission denied (%s).", authlist);
443: authctxt->method = method;
1.119 markus 444:
445: /* reset the per method handler */
446: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
447: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
448:
449: /* and try new method */
1.51 markus 450: if (method->userauth(authctxt) != 0) {
451: debug2("we sent a %s packet, wait for reply", method->name);
452: break;
453: } else {
454: debug2("we did not send a packet, disable method");
455: method->enabled = NULL;
456: }
457: }
458: }
1.105 deraadt 459:
1.169 djm 460: /* ARGSUSED */
1.51 markus 461: void
1.92 markus 462: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 463: {
1.35 markus 464: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 465: "type %d", type);
1.35 markus 466: }
1.105 deraadt 467:
1.169 djm 468: /* ARGSUSED */
1.35 markus 469: void
1.92 markus 470: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 471: {
1.166 djm 472: char *msg, *raw, *lang;
473: u_int len;
1.126 deraadt 474:
1.35 markus 475: debug3("input_userauth_banner");
1.166 djm 476: raw = packet_get_string(&len);
1.35 markus 477: lang = packet_get_string(NULL);
1.167 markus 478: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 479: if (len > 65536)
480: len = 65536;
1.168 deraadt 481: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 482: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 483: fprintf(stderr, "%s", msg);
1.166 djm 484: xfree(msg);
485: }
486: xfree(raw);
1.35 markus 487: xfree(lang);
1.20 markus 488: }
1.105 deraadt 489:
1.169 djm 490: /* ARGSUSED */
1.20 markus 491: void
1.92 markus 492: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 493: {
494: Authctxt *authctxt = ctxt;
1.172 djm 495:
1.20 markus 496: if (authctxt == NULL)
497: fatal("input_userauth_success: no authentication context");
1.126 deraadt 498: if (authctxt->authlist) {
1.51 markus 499: xfree(authctxt->authlist);
1.126 deraadt 500: authctxt->authlist = NULL;
501: }
1.172 djm 502: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
503: authctxt->method->cleanup(authctxt);
1.126 deraadt 504: if (authctxt->methoddata) {
1.121 markus 505: xfree(authctxt->methoddata);
1.126 deraadt 506: authctxt->methoddata = NULL;
507: }
1.20 markus 508: authctxt->success = 1; /* break out */
509: }
1.105 deraadt 510:
1.172 djm 511: void
512: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
513: {
514: Authctxt *authctxt = ctxt;
515:
516: if (authctxt == NULL)
517: fatal("%s: no authentication context", __func__);
518:
519: fatal("Unexpected authentication success during %s.",
520: authctxt->method->name);
521: }
522:
1.169 djm 523: /* ARGSUSED */
1.20 markus 524: void
1.92 markus 525: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 526: {
527: Authctxt *authctxt = ctxt;
528: char *authlist = NULL;
529: int partial;
530:
531: if (authctxt == NULL)
532: fatal("input_userauth_failure: no authentication context");
533:
1.23 markus 534: authlist = packet_get_string(NULL);
1.20 markus 535: partial = packet_get_char();
1.90 markus 536: packet_check_eom();
1.20 markus 537:
1.193 markus 538: if (partial != 0) {
1.116 itojun 539: logit("Authenticated with partial success.");
1.193 markus 540: /* reset state */
541: pubkey_cleanup(authctxt);
542: pubkey_prepare(authctxt);
543: }
1.109 markus 544: debug("Authentications that can continue: %s", authlist);
1.20 markus 545:
1.51 markus 546: userauth(authctxt, authlist);
547: }
1.169 djm 548:
549: /* ARGSUSED */
1.51 markus 550: void
1.92 markus 551: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 552: {
553: Authctxt *authctxt = ctxt;
554: Key *key = NULL;
1.117 markus 555: Identity *id = NULL;
1.51 markus 556: Buffer b;
1.96 markus 557: int pktype, sent = 0;
558: u_int alen, blen;
559: char *pkalg, *fp;
560: u_char *pkblob;
1.51 markus 561:
562: if (authctxt == NULL)
563: fatal("input_userauth_pk_ok: no authentication context");
564: if (datafellows & SSH_BUG_PKOK) {
565: /* this is similar to SSH_BUG_PKAUTH */
566: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
567: pkblob = packet_get_string(&blen);
568: buffer_init(&b);
569: buffer_append(&b, pkblob, blen);
570: pkalg = buffer_get_string(&b, &alen);
571: buffer_free(&b);
572: } else {
573: pkalg = packet_get_string(&alen);
574: pkblob = packet_get_string(&blen);
575: }
1.90 markus 576: packet_check_eom();
1.51 markus 577:
1.117 markus 578: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 579:
1.117 markus 580: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
581: debug("unknown pkalg %s", pkalg);
582: goto done;
583: }
584: if ((key = key_from_blob(pkblob, blen)) == NULL) {
585: debug("no key from blob. pkalg %s", pkalg);
586: goto done;
587: }
588: if (key->type != pktype) {
589: error("input_userauth_pk_ok: type mismatch "
590: "for decoded key (received %d, expected %d)",
591: key->type, pktype);
592: goto done;
593: }
594: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
595: debug2("input_userauth_pk_ok: fp %s", fp);
596: xfree(fp);
597:
1.127 markus 598: /*
599: * search keys in the reverse order, because last candidate has been
600: * moved to the end of the queue. this also avoids confusion by
601: * duplicate keys
602: */
1.136 henning 603: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 604: if (key_equal(key, id->key)) {
605: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 606: break;
607: }
1.117 markus 608: }
609: done:
1.51 markus 610: if (key != NULL)
611: key_free(key);
612: xfree(pkalg);
613: xfree(pkblob);
614:
1.106 deraadt 615: /* try another method if we did not send a packet */
1.51 markus 616: if (sent == 0)
617: userauth(authctxt, NULL);
1.20 markus 618: }
1.121 markus 619:
620: #ifdef GSSAPI
1.133 djm 621: int
1.121 markus 622: userauth_gssapi(Authctxt *authctxt)
623: {
624: Gssctxt *gssctxt = NULL;
1.128 avsm 625: static gss_OID_set gss_supported = NULL;
1.139 djm 626: static u_int mech = 0;
1.121 markus 627: OM_uint32 min;
628: int ok = 0;
629:
630: /* Try one GSSAPI method at a time, rather than sending them all at
631: * once. */
632:
1.128 avsm 633: if (gss_supported == NULL)
634: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 635:
636: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 637: while (mech < gss_supported->count && !ok) {
1.121 markus 638: /* My DER encoding requires length<128 */
1.128 avsm 639: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 640: ssh_gssapi_check_mechanism(&gssctxt,
641: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 642: ok = 1; /* Mechanism works */
643: } else {
644: mech++;
645: }
646: }
647:
1.161 djm 648: if (!ok)
1.139 djm 649: return 0;
1.121 markus 650:
651: authctxt->methoddata=(void *)gssctxt;
652:
653: packet_start(SSH2_MSG_USERAUTH_REQUEST);
654: packet_put_cstring(authctxt->server_user);
655: packet_put_cstring(authctxt->service);
656: packet_put_cstring(authctxt->method->name);
657:
658: packet_put_int(1);
659:
1.129 markus 660: packet_put_int((gss_supported->elements[mech].length) + 2);
661: packet_put_char(SSH_GSS_OIDTYPE);
662: packet_put_char(gss_supported->elements[mech].length);
663: packet_put_raw(gss_supported->elements[mech].elements,
664: gss_supported->elements[mech].length);
1.121 markus 665:
666: packet_send();
667:
668: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
669: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
670: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
671: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
672:
673: mech++; /* Move along to next candidate */
674:
675: return 1;
676: }
677:
1.130 markus 678: static OM_uint32
679: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
680: {
681: Authctxt *authctxt = ctxt;
682: Gssctxt *gssctxt = authctxt->methoddata;
683: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 684: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
685: gss_buffer_desc gssbuf;
1.132 markus 686: OM_uint32 status, ms, flags;
687: Buffer b;
1.133 djm 688:
1.130 markus 689: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 690: recv_tok, &send_tok, &flags);
1.130 markus 691:
692: if (send_tok.length > 0) {
693: if (GSS_ERROR(status))
694: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
695: else
696: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 697:
1.130 markus 698: packet_put_string(send_tok.value, send_tok.length);
699: packet_send();
700: gss_release_buffer(&ms, &send_tok);
701: }
1.133 djm 702:
1.130 markus 703: if (status == GSS_S_COMPLETE) {
1.132 markus 704: /* send either complete or MIC, depending on mechanism */
705: if (!(flags & GSS_C_INTEG_FLAG)) {
706: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
707: packet_send();
708: } else {
709: ssh_gssapi_buildmic(&b, authctxt->server_user,
710: authctxt->service, "gssapi-with-mic");
711:
712: gssbuf.value = buffer_ptr(&b);
713: gssbuf.length = buffer_len(&b);
1.133 djm 714:
1.132 markus 715: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 716:
1.132 markus 717: if (!GSS_ERROR(status)) {
718: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
719: packet_put_string(mic.value, mic.length);
1.133 djm 720:
1.132 markus 721: packet_send();
722: }
1.133 djm 723:
1.132 markus 724: buffer_free(&b);
725: gss_release_buffer(&ms, &mic);
1.133 djm 726: }
1.130 markus 727: }
1.133 djm 728:
1.130 markus 729: return status;
730: }
731:
1.169 djm 732: /* ARGSUSED */
1.121 markus 733: void
734: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
735: {
736: Authctxt *authctxt = ctxt;
737: Gssctxt *gssctxt;
738: int oidlen;
739: char *oidv;
740:
741: if (authctxt == NULL)
742: fatal("input_gssapi_response: no authentication context");
743: gssctxt = authctxt->methoddata;
744:
745: /* Setup our OID */
746: oidv = packet_get_string(&oidlen);
747:
1.129 markus 748: if (oidlen <= 2 ||
749: oidv[0] != SSH_GSS_OIDTYPE ||
750: oidv[1] != oidlen - 2) {
1.130 markus 751: xfree(oidv);
1.129 markus 752: debug("Badly encoded mechanism OID received");
753: userauth(authctxt, NULL);
754: return;
1.121 markus 755: }
1.129 markus 756:
757: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
758: fatal("Server returned different OID than expected");
1.121 markus 759:
760: packet_check_eom();
761:
762: xfree(oidv);
763:
1.130 markus 764: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 765: /* Start again with next method on list */
766: debug("Trying to start again");
767: userauth(authctxt, NULL);
768: return;
769: }
770: }
771:
1.169 djm 772: /* ARGSUSED */
1.121 markus 773: void
774: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
775: {
776: Authctxt *authctxt = ctxt;
777: gss_buffer_desc recv_tok;
1.130 markus 778: OM_uint32 status;
1.121 markus 779: u_int slen;
780:
781: if (authctxt == NULL)
782: fatal("input_gssapi_response: no authentication context");
783:
784: recv_tok.value = packet_get_string(&slen);
785: recv_tok.length = slen; /* safe typecast */
786:
787: packet_check_eom();
788:
1.130 markus 789: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 790:
791: xfree(recv_tok.value);
792:
793: if (GSS_ERROR(status)) {
794: /* Start again with the next method in the list */
795: userauth(authctxt, NULL);
796: return;
797: }
798: }
799:
1.169 djm 800: /* ARGSUSED */
1.121 markus 801: void
802: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
803: {
804: Authctxt *authctxt = ctxt;
805: Gssctxt *gssctxt;
806: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
807: gss_buffer_desc recv_tok;
1.194 djm 808: OM_uint32 ms;
1.123 deraadt 809: u_int len;
1.121 markus 810:
811: if (authctxt == NULL)
812: fatal("input_gssapi_response: no authentication context");
813: gssctxt = authctxt->methoddata;
814:
1.123 deraadt 815: recv_tok.value = packet_get_string(&len);
816: recv_tok.length = len;
1.121 markus 817:
818: packet_check_eom();
819:
820: /* Stick it into GSSAPI and see what it says */
1.194 djm 821: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 822: &recv_tok, &send_tok, NULL);
1.121 markus 823:
824: xfree(recv_tok.value);
825: gss_release_buffer(&ms, &send_tok);
826:
827: /* Server will be returning a failed packet after this one */
828: }
829:
1.169 djm 830: /* ARGSUSED */
1.121 markus 831: void
832: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
833: {
834: char *msg;
835: char *lang;
836:
1.194 djm 837: /* maj */(void)packet_get_int();
838: /* min */(void)packet_get_int();
1.121 markus 839: msg=packet_get_string(NULL);
840: lang=packet_get_string(NULL);
841:
842: packet_check_eom();
843:
1.143 stevesk 844: debug("Server GSSAPI Error:\n%s", msg);
1.121 markus 845: xfree(msg);
846: xfree(lang);
847: }
848: #endif /* GSSAPI */
1.20 markus 849:
1.1 markus 850: int
1.23 markus 851: userauth_none(Authctxt *authctxt)
852: {
853: /* initial userauth request */
854: packet_start(SSH2_MSG_USERAUTH_REQUEST);
855: packet_put_cstring(authctxt->server_user);
856: packet_put_cstring(authctxt->service);
857: packet_put_cstring(authctxt->method->name);
858: packet_send();
859: return 1;
860: }
861:
862: int
1.20 markus 863: userauth_passwd(Authctxt *authctxt)
1.1 markus 864: {
1.6 markus 865: static int attempt = 0;
1.99 markus 866: char prompt[150];
1.1 markus 867: char *password;
1.175 dtucker 868: const char *host = options.host_key_alias ? options.host_key_alias :
869: authctxt->host;
1.6 markus 870:
1.13 todd 871: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 872: return 0;
1.13 todd 873:
1.87 deraadt 874: if (attempt != 1)
1.13 todd 875: error("Permission denied, please try again.");
1.1 markus 876:
1.43 itojun 877: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 878: authctxt->server_user, host);
1.1 markus 879: password = read_passphrase(prompt, 0);
880: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 881: packet_put_cstring(authctxt->server_user);
882: packet_put_cstring(authctxt->service);
1.23 markus 883: packet_put_cstring(authctxt->method->name);
1.1 markus 884: packet_put_char(0);
1.49 markus 885: packet_put_cstring(password);
1.1 markus 886: memset(password, 0, strlen(password));
887: xfree(password);
1.85 markus 888: packet_add_padding(64);
1.1 markus 889: packet_send();
1.99 markus 890:
1.104 deraadt 891: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 892: &input_userauth_passwd_changereq);
893:
1.1 markus 894: return 1;
895: }
1.169 djm 896:
1.99 markus 897: /*
898: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
899: */
1.169 djm 900: /* ARGSUSED */
1.99 markus 901: void
1.153 djm 902: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 903: {
904: Authctxt *authctxt = ctxt;
905: char *info, *lang, *password = NULL, *retype = NULL;
906: char prompt[150];
1.175 dtucker 907: const char *host = options.host_key_alias ? options.host_key_alias :
908: authctxt->host;
1.99 markus 909:
910: debug2("input_userauth_passwd_changereq");
911:
912: if (authctxt == NULL)
913: fatal("input_userauth_passwd_changereq: "
914: "no authentication context");
915:
916: info = packet_get_string(NULL);
917: lang = packet_get_string(NULL);
918: if (strlen(info) > 0)
1.116 itojun 919: logit("%s", info);
1.99 markus 920: xfree(info);
921: xfree(lang);
922: packet_start(SSH2_MSG_USERAUTH_REQUEST);
923: packet_put_cstring(authctxt->server_user);
924: packet_put_cstring(authctxt->service);
925: packet_put_cstring(authctxt->method->name);
926: packet_put_char(1); /* additional info */
1.104 deraadt 927: snprintf(prompt, sizeof(prompt),
1.99 markus 928: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 929: authctxt->server_user, host);
1.99 markus 930: password = read_passphrase(prompt, 0);
931: packet_put_cstring(password);
932: memset(password, 0, strlen(password));
933: xfree(password);
934: password = NULL;
935: while (password == NULL) {
1.104 deraadt 936: snprintf(prompt, sizeof(prompt),
1.99 markus 937: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 938: authctxt->server_user, host);
1.99 markus 939: password = read_passphrase(prompt, RP_ALLOW_EOF);
940: if (password == NULL) {
941: /* bail out */
942: return;
943: }
1.104 deraadt 944: snprintf(prompt, sizeof(prompt),
1.99 markus 945: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 946: authctxt->server_user, host);
1.99 markus 947: retype = read_passphrase(prompt, 0);
948: if (strcmp(password, retype) != 0) {
949: memset(password, 0, strlen(password));
950: xfree(password);
1.116 itojun 951: logit("Mismatch; try again, EOF to quit.");
1.99 markus 952: password = NULL;
953: }
954: memset(retype, 0, strlen(retype));
955: xfree(retype);
956: }
957: packet_put_cstring(password);
958: memset(password, 0, strlen(password));
959: xfree(password);
960: packet_add_padding(64);
961: packet_send();
1.104 deraadt 962:
963: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 964: &input_userauth_passwd_changereq);
1.117 markus 965: }
966:
1.170 djm 967: #ifdef JPAKE
968: static char *
969: pw_encrypt(const char *password, const char *crypt_scheme, const char *salt)
970: {
971: /* OpenBSD crypt(3) handles all of these */
972: if (strcmp(crypt_scheme, "crypt") == 0 ||
973: strcmp(crypt_scheme, "bcrypt") == 0 ||
974: strcmp(crypt_scheme, "md5crypt") == 0 ||
975: strcmp(crypt_scheme, "crypt-extended") == 0)
976: return xstrdup(crypt(password, salt));
977: error("%s: unsupported password encryption scheme \"%.100s\"",
978: __func__, crypt_scheme);
979: return NULL;
980: }
981:
982: static BIGNUM *
983: jpake_password_to_secret(Authctxt *authctxt, const char *crypt_scheme,
984: const char *salt)
985: {
986: char prompt[256], *password, *crypted;
987: u_char *secret;
988: u_int secret_len;
989: BIGNUM *ret;
990:
991: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password (JPAKE): ",
992: authctxt->server_user, authctxt->host);
993: password = read_passphrase(prompt, 0);
994:
995: if ((crypted = pw_encrypt(password, crypt_scheme, salt)) == NULL) {
996: logit("Disabling %s authentication", authctxt->method->name);
997: authctxt->method->enabled = NULL;
998: /* Continue with an empty password to fail gracefully */
999: crypted = xstrdup("");
1000: }
1001:
1002: #ifdef JPAKE_DEBUG
1003: debug3("%s: salt = %s", __func__, salt);
1004: debug3("%s: scheme = %s", __func__, crypt_scheme);
1005: debug3("%s: crypted = %s", __func__, crypted);
1006: #endif
1007:
1008: if (hash_buffer(crypted, strlen(crypted), EVP_sha256(),
1009: &secret, &secret_len) != 0)
1010: fatal("%s: hash_buffer", __func__);
1011:
1012: bzero(password, strlen(password));
1013: bzero(crypted, strlen(crypted));
1014: xfree(password);
1015: xfree(crypted);
1016:
1017: if ((ret = BN_bin2bn(secret, secret_len, NULL)) == NULL)
1018: fatal("%s: BN_bin2bn (secret)", __func__);
1019: bzero(secret, secret_len);
1020: xfree(secret);
1021:
1022: return ret;
1023: }
1024:
1025: /* ARGSUSED */
1026: void
1027: input_userauth_jpake_server_step1(int type, u_int32_t seq, void *ctxt)
1028: {
1029: Authctxt *authctxt = ctxt;
1030: struct jpake_ctx *pctx = authctxt->methoddata;
1031: u_char *x3_proof, *x4_proof, *x2_s_proof;
1032: u_int x3_proof_len, x4_proof_len, x2_s_proof_len;
1033: char *crypt_scheme, *salt;
1034:
1035: /* Disable this message */
1036: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1, NULL);
1037:
1038: if ((pctx->g_x3 = BN_new()) == NULL ||
1039: (pctx->g_x4 = BN_new()) == NULL)
1040: fatal("%s: BN_new", __func__);
1041:
1042: /* Fetch step 1 values */
1043: crypt_scheme = packet_get_string(NULL);
1044: salt = packet_get_string(NULL);
1045: pctx->server_id = packet_get_string(&pctx->server_id_len);
1046: packet_get_bignum2(pctx->g_x3);
1047: packet_get_bignum2(pctx->g_x4);
1048: x3_proof = packet_get_string(&x3_proof_len);
1049: x4_proof = packet_get_string(&x4_proof_len);
1050: packet_check_eom();
1051:
1052: JPAKE_DEBUG_CTX((pctx, "step 1 received in %s", __func__));
1053:
1054: /* Obtain password and derive secret */
1055: pctx->s = jpake_password_to_secret(authctxt, crypt_scheme, salt);
1056: bzero(crypt_scheme, strlen(crypt_scheme));
1057: bzero(salt, strlen(salt));
1058: xfree(crypt_scheme);
1059: xfree(salt);
1060: JPAKE_DEBUG_BN((pctx->s, "%s: s = ", __func__));
1061:
1062: /* Calculate step 2 values */
1063: jpake_step2(pctx->grp, pctx->s, pctx->g_x1,
1064: pctx->g_x3, pctx->g_x4, pctx->x2,
1065: pctx->server_id, pctx->server_id_len,
1066: pctx->client_id, pctx->client_id_len,
1067: x3_proof, x3_proof_len,
1068: x4_proof, x4_proof_len,
1069: &pctx->a,
1070: &x2_s_proof, &x2_s_proof_len);
1071:
1072: bzero(x3_proof, x3_proof_len);
1073: bzero(x4_proof, x4_proof_len);
1074: xfree(x3_proof);
1075: xfree(x4_proof);
1076:
1077: JPAKE_DEBUG_CTX((pctx, "step 2 sending in %s", __func__));
1078:
1079: /* Send values for step 2 */
1080: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP2);
1081: packet_put_bignum2(pctx->a);
1082: packet_put_string(x2_s_proof, x2_s_proof_len);
1083: packet_send();
1084:
1085: bzero(x2_s_proof, x2_s_proof_len);
1086: xfree(x2_s_proof);
1087:
1088: /* Expect step 2 packet from peer */
1089: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2,
1090: input_userauth_jpake_server_step2);
1091: }
1092:
1093: /* ARGSUSED */
1094: void
1095: input_userauth_jpake_server_step2(int type, u_int32_t seq, void *ctxt)
1096: {
1097: Authctxt *authctxt = ctxt;
1098: struct jpake_ctx *pctx = authctxt->methoddata;
1099: u_char *x4_s_proof;
1100: u_int x4_s_proof_len;
1101:
1102: /* Disable this message */
1103: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP2, NULL);
1104:
1105: if ((pctx->b = BN_new()) == NULL)
1106: fatal("%s: BN_new", __func__);
1107:
1108: /* Fetch step 2 values */
1109: packet_get_bignum2(pctx->b);
1110: x4_s_proof = packet_get_string(&x4_s_proof_len);
1111: packet_check_eom();
1112:
1113: JPAKE_DEBUG_CTX((pctx, "step 2 received in %s", __func__));
1114:
1115: /* Derive shared key and calculate confirmation hash */
1116: jpake_key_confirm(pctx->grp, pctx->s, pctx->b,
1117: pctx->x2, pctx->g_x1, pctx->g_x2, pctx->g_x3, pctx->g_x4,
1118: pctx->client_id, pctx->client_id_len,
1119: pctx->server_id, pctx->server_id_len,
1120: session_id2, session_id2_len,
1121: x4_s_proof, x4_s_proof_len,
1122: &pctx->k,
1123: &pctx->h_k_cid_sessid, &pctx->h_k_cid_sessid_len);
1124:
1125: bzero(x4_s_proof, x4_s_proof_len);
1126: xfree(x4_s_proof);
1127:
1128: JPAKE_DEBUG_CTX((pctx, "confirm sending in %s", __func__));
1129:
1130: /* Send key confirmation proof */
1131: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_CONFIRM);
1132: packet_put_string(pctx->h_k_cid_sessid, pctx->h_k_cid_sessid_len);
1133: packet_send();
1134:
1135: /* Expect confirmation from peer */
1136: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM,
1137: input_userauth_jpake_server_confirm);
1138: }
1139:
1140: /* ARGSUSED */
1141: void
1142: input_userauth_jpake_server_confirm(int type, u_int32_t seq, void *ctxt)
1143: {
1144: Authctxt *authctxt = ctxt;
1145: struct jpake_ctx *pctx = authctxt->methoddata;
1146:
1147: /* Disable this message */
1148: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_CONFIRM, NULL);
1149:
1150: pctx->h_k_sid_sessid = packet_get_string(&pctx->h_k_sid_sessid_len);
1151: packet_check_eom();
1152:
1153: JPAKE_DEBUG_CTX((pctx, "confirm received in %s", __func__));
1154:
1155: /* Verify expected confirmation hash */
1156: if (jpake_check_confirm(pctx->k,
1157: pctx->server_id, pctx->server_id_len,
1158: session_id2, session_id2_len,
1159: pctx->h_k_sid_sessid, pctx->h_k_sid_sessid_len) == 1)
1160: debug("%s: %s success", __func__, authctxt->method->name);
1161: else {
1162: debug("%s: confirmation mismatch", __func__);
1163: /* XXX stash this so if auth succeeds then we can warn/kill */
1164: }
1165:
1166: userauth_jpake_cleanup(authctxt);
1167: }
1168: #endif /* JPAKE */
1169:
1.117 markus 1170: static int
1171: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
1172: u_char *data, u_int datalen)
1173: {
1174: Key *prv;
1175: int ret;
1.99 markus 1176:
1.117 markus 1177: /* the agent supports this key */
1178: if (id->ac)
1179: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
1180: data, datalen));
1181: /*
1182: * we have already loaded the private key or
1183: * the private key is stored in external hardware
1184: */
1185: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
1186: return (key_sign(id->key, sigp, lenp, data, datalen));
1187: /* load the private key from the file */
1.191 dtucker 1188: if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
1.117 markus 1189: return (-1);
1190: ret = key_sign(prv, sigp, lenp, data, datalen);
1191: key_free(prv);
1192: return (ret);
1.51 markus 1193: }
1194:
1.76 itojun 1195: static int
1.117 markus 1196: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1197: {
1198: Buffer b;
1.32 markus 1199: u_char *blob, *signature;
1.96 markus 1200: u_int bloblen, slen;
1.120 markus 1201: u_int skip = 0;
1.17 markus 1202: int ret = -1;
1.23 markus 1203: int have_sig = 1;
1.182 djm 1204: char *fp;
1.1 markus 1205:
1.182 djm 1206: fp = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
1207: debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1208: xfree(fp);
1.51 markus 1209:
1.117 markus 1210: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1211: /* we cannot handle this key */
1.30 markus 1212: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1213: return 0;
1214: }
1.1 markus 1215: /* data to be signed */
1216: buffer_init(&b);
1.26 markus 1217: if (datafellows & SSH_OLD_SESSIONID) {
1218: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1219: skip = session_id2_len;
1.26 markus 1220: } else {
1.14 markus 1221: buffer_put_string(&b, session_id2, session_id2_len);
1222: skip = buffer_len(&b);
1223: }
1.1 markus 1224: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1225: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1226: buffer_put_cstring(&b,
1.30 markus 1227: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1228: "ssh-userauth" :
1.20 markus 1229: authctxt->service);
1.30 markus 1230: if (datafellows & SSH_BUG_PKAUTH) {
1231: buffer_put_char(&b, have_sig);
1232: } else {
1233: buffer_put_cstring(&b, authctxt->method->name);
1234: buffer_put_char(&b, have_sig);
1.117 markus 1235: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1236: }
1.1 markus 1237: buffer_put_string(&b, blob, bloblen);
1238:
1239: /* generate signature */
1.117 markus 1240: ret = identity_sign(id, &signature, &slen,
1.51 markus 1241: buffer_ptr(&b), buffer_len(&b));
1.17 markus 1242: if (ret == -1) {
1243: xfree(blob);
1244: buffer_free(&b);
1245: return 0;
1246: }
1.28 markus 1247: #ifdef DEBUG_PK
1.1 markus 1248: buffer_dump(&b);
1249: #endif
1.30 markus 1250: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1251: buffer_clear(&b);
1252: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1253: skip = session_id2_len;
1.10 markus 1254: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1255: buffer_put_cstring(&b, authctxt->server_user);
1256: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1257: buffer_put_cstring(&b, authctxt->method->name);
1258: buffer_put_char(&b, have_sig);
1.30 markus 1259: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1260: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1261: buffer_put_string(&b, blob, bloblen);
1262: }
1263: xfree(blob);
1.51 markus 1264:
1.1 markus 1265: /* append signature */
1266: buffer_put_string(&b, signature, slen);
1267: xfree(signature);
1268:
1269: /* skip session id and packet type */
1.14 markus 1270: if (buffer_len(&b) < skip + 1)
1.20 markus 1271: fatal("userauth_pubkey: internal error");
1.14 markus 1272: buffer_consume(&b, skip + 1);
1.1 markus 1273:
1274: /* put remaining data from buffer into packet */
1275: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1276: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1277: buffer_free(&b);
1278: packet_send();
1.17 markus 1279:
1280: return 1;
1.16 markus 1281: }
1282:
1.76 itojun 1283: static int
1.117 markus 1284: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1285: {
1.51 markus 1286: u_char *blob;
1.97 markus 1287: u_int bloblen, have_sig = 0;
1.20 markus 1288:
1.51 markus 1289: debug3("send_pubkey_test");
1.16 markus 1290:
1.117 markus 1291: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1292: /* we cannot handle this key */
1293: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1294: return 0;
1295: }
1.51 markus 1296: /* register callback for USERAUTH_PK_OK message */
1297: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1298:
1299: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1300: packet_put_cstring(authctxt->server_user);
1301: packet_put_cstring(authctxt->service);
1302: packet_put_cstring(authctxt->method->name);
1303: packet_put_char(have_sig);
1304: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1305: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1306: packet_put_string(blob, bloblen);
1307: xfree(blob);
1308: packet_send();
1309: return 1;
1310: }
1311:
1.76 itojun 1312: static Key *
1.191 dtucker 1313: load_identity_file(char *filename, int userprovided)
1.51 markus 1314: {
1315: Key *private;
1316: char prompt[300], *passphrase;
1.178 dtucker 1317: int perm_ok = 0, quit, i;
1.52 markus 1318: struct stat st;
1.16 markus 1319:
1.52 markus 1320: if (stat(filename, &st) < 0) {
1.191 dtucker 1321: (userprovided ? logit : debug3)("no such identity: %s: %s",
1322: filename, strerror(errno));
1.52 markus 1323: return NULL;
1324: }
1.152 dtucker 1325: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
1326: if (!perm_ok)
1327: return NULL;
1.56 markus 1328: if (private == NULL) {
1329: if (options.batch_mode)
1.51 markus 1330: return NULL;
1.16 markus 1331: snprintf(prompt, sizeof prompt,
1.88 deraadt 1332: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 1333: for (i = 0; i < options.number_of_password_prompts; i++) {
1334: passphrase = read_passphrase(prompt, 0);
1335: if (strcmp(passphrase, "") != 0) {
1.152 dtucker 1336: private = key_load_private_type(KEY_UNSPEC,
1337: filename, passphrase, NULL, NULL);
1.51 markus 1338: quit = 0;
1.20 markus 1339: } else {
1340: debug2("no passphrase given, try next key");
1.51 markus 1341: quit = 1;
1.20 markus 1342: }
1343: memset(passphrase, 0, strlen(passphrase));
1344: xfree(passphrase);
1.56 markus 1345: if (private != NULL || quit)
1.20 markus 1346: break;
1347: debug2("bad passphrase given, try again...");
1.16 markus 1348: }
1349: }
1.51 markus 1350: return private;
1351: }
1352:
1.117 markus 1353: /*
1354: * try keys in the following order:
1355: * 1. agent keys that are found in the config file
1356: * 2. other agent keys
1357: * 3. keys that are only listed in the config file
1358: */
1359: static void
1360: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1361: {
1.190 djm 1362: Identity *id, *id2, *tmp;
1.117 markus 1363: Idlist agent, files, *preferred;
1364: Key *key;
1365: AuthenticationConnection *ac;
1366: char *comment;
1367: int i, found;
1.51 markus 1368:
1.117 markus 1369: TAILQ_INIT(&agent); /* keys from the agent */
1370: TAILQ_INIT(&files); /* keys from the config file */
1371: preferred = &authctxt->keys;
1372: TAILQ_INIT(preferred); /* preferred order of keys */
1373:
1.190 djm 1374: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1375: for (i = 0; i < options.num_identity_files; i++) {
1376: key = options.identity_keys[i];
1377: if (key && key->type == KEY_RSA1)
1.180 djm 1378: continue;
1379: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1380: continue;
1381: options.identity_keys[i] = NULL;
1.150 djm 1382: id = xcalloc(1, sizeof(*id));
1.117 markus 1383: id->key = key;
1384: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1385: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1386: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1387: }
1388: /* Prefer PKCS11 keys that are explicitly listed */
1389: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1390: if (id->key == NULL || (id->key->flags & KEY_FLAG_EXT) == 0)
1391: continue;
1392: found = 0;
1393: TAILQ_FOREACH(id2, &files, next) {
1394: if (id2->key == NULL ||
1395: (id2->key->flags & KEY_FLAG_EXT) != 0)
1396: continue;
1397: if (key_equal(id->key, id2->key)) {
1398: TAILQ_REMOVE(&files, id, next);
1399: TAILQ_INSERT_TAIL(preferred, id, next);
1400: found = 1;
1401: break;
1402: }
1403: }
1404: /* If IdentitiesOnly set and key not found then don't use it */
1405: if (!found && options.identities_only) {
1406: TAILQ_REMOVE(&files, id, next);
1.195 djm 1407: bzero(id, sizeof(*id));
1.190 djm 1408: free(id);
1409: }
1.117 markus 1410: }
1411: /* list of keys supported by the agent */
1412: if ((ac = ssh_get_authentication_connection())) {
1413: for (key = ssh_get_first_identity(ac, &comment, 2);
1414: key != NULL;
1415: key = ssh_get_next_identity(ac, &comment, 2)) {
1416: found = 0;
1417: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1418: /* agent keys from the config file are preferred */
1.117 markus 1419: if (key_equal(key, id->key)) {
1420: key_free(key);
1421: xfree(comment);
1422: TAILQ_REMOVE(&files, id, next);
1423: TAILQ_INSERT_TAIL(preferred, id, next);
1424: id->ac = ac;
1425: found = 1;
1426: break;
1427: }
1428: }
1.135 markus 1429: if (!found && !options.identities_only) {
1.150 djm 1430: id = xcalloc(1, sizeof(*id));
1.117 markus 1431: id->key = key;
1432: id->filename = comment;
1433: id->ac = ac;
1434: TAILQ_INSERT_TAIL(&agent, id, next);
1435: }
1436: }
1437: /* append remaining agent keys */
1438: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1439: TAILQ_REMOVE(&agent, id, next);
1440: TAILQ_INSERT_TAIL(preferred, id, next);
1441: }
1442: authctxt->agent = ac;
1443: }
1444: /* append remaining keys from the config file */
1445: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1446: TAILQ_REMOVE(&files, id, next);
1447: TAILQ_INSERT_TAIL(preferred, id, next);
1448: }
1449: TAILQ_FOREACH(id, preferred, next) {
1.191 dtucker 1450: debug2("key: %s (%p),%s", id->filename, id->key,
1451: id->userprovided ? " explicit" : "");
1.117 markus 1452: }
1.17 markus 1453: }
1454:
1.117 markus 1455: static void
1456: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1457: {
1.117 markus 1458: Identity *id;
1.51 markus 1459:
1.117 markus 1460: if (authctxt->agent != NULL)
1461: ssh_close_authentication_connection(authctxt->agent);
1462: for (id = TAILQ_FIRST(&authctxt->keys); id;
1463: id = TAILQ_FIRST(&authctxt->keys)) {
1464: TAILQ_REMOVE(&authctxt->keys, id, next);
1465: if (id->key)
1466: key_free(id->key);
1467: if (id->filename)
1468: xfree(id->filename);
1469: xfree(id);
1470: }
1.1 markus 1471: }
1472:
1.20 markus 1473: int
1474: userauth_pubkey(Authctxt *authctxt)
1475: {
1.117 markus 1476: Identity *id;
1.20 markus 1477: int sent = 0;
1478:
1.117 markus 1479: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1480: if (id->tried++)
1481: return (0);
1.127 markus 1482: /* move key to the end of the queue */
1.117 markus 1483: TAILQ_REMOVE(&authctxt->keys, id, next);
1484: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1485: /*
1486: * send a test message if we have the public key. for
1487: * encrypted keys we cannot do this and have to load the
1488: * private key instead
1489: */
1490: if (id->key && id->key->type != KEY_RSA1) {
1.181 djm 1491: debug("Offering %s public key: %s", key_type(id->key),
1492: id->filename);
1.117 markus 1493: sent = send_pubkey_test(authctxt, id);
1494: } else if (id->key == NULL) {
1495: debug("Trying private key: %s", id->filename);
1.191 dtucker 1496: id->key = load_identity_file(id->filename,
1497: id->userprovided);
1.117 markus 1498: if (id->key != NULL) {
1499: id->isprivate = 1;
1500: sent = sign_and_send_pubkey(authctxt, id);
1501: key_free(id->key);
1502: id->key = NULL;
1.51 markus 1503: }
1504: }
1.117 markus 1505: if (sent)
1506: return (sent);
1.28 markus 1507: }
1.117 markus 1508: return (0);
1.20 markus 1509: }
1510:
1.23 markus 1511: /*
1512: * Send userauth request message specifying keyboard-interactive method.
1513: */
1514: int
1515: userauth_kbdint(Authctxt *authctxt)
1516: {
1517: static int attempt = 0;
1518:
1519: if (attempt++ >= options.number_of_password_prompts)
1520: return 0;
1.82 markus 1521: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1522: if (attempt > 1 && !authctxt->info_req_seen) {
1523: debug3("userauth_kbdint: disable: no info_req_seen");
1524: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1525: return 0;
1526: }
1.23 markus 1527:
1528: debug2("userauth_kbdint");
1529: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1530: packet_put_cstring(authctxt->server_user);
1531: packet_put_cstring(authctxt->service);
1532: packet_put_cstring(authctxt->method->name);
1533: packet_put_cstring(""); /* lang */
1534: packet_put_cstring(options.kbd_interactive_devices ?
1535: options.kbd_interactive_devices : "");
1536: packet_send();
1537:
1538: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1539: return 1;
1540: }
1541:
1542: /*
1.46 markus 1543: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1544: */
1545: void
1.92 markus 1546: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1547: {
1548: Authctxt *authctxt = ctxt;
1.46 markus 1549: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1550: u_int num_prompts, i;
1.23 markus 1551: int echo = 0;
1552:
1553: debug2("input_userauth_info_req");
1554:
1555: if (authctxt == NULL)
1556: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1557:
1558: authctxt->info_req_seen = 1;
1.23 markus 1559:
1560: name = packet_get_string(NULL);
1561: inst = packet_get_string(NULL);
1562: lang = packet_get_string(NULL);
1563: if (strlen(name) > 0)
1.116 itojun 1564: logit("%s", name);
1.23 markus 1565: if (strlen(inst) > 0)
1.116 itojun 1566: logit("%s", inst);
1.46 markus 1567: xfree(name);
1.23 markus 1568: xfree(inst);
1.46 markus 1569: xfree(lang);
1.23 markus 1570:
1571: num_prompts = packet_get_int();
1572: /*
1573: * Begin to build info response packet based on prompts requested.
1574: * We commit to providing the correct number of responses, so if
1575: * further on we run into a problem that prevents this, we have to
1576: * be sure and clean this up and send a correct error response.
1577: */
1578: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1579: packet_put_int(num_prompts);
1580:
1.73 markus 1581: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1582: for (i = 0; i < num_prompts; i++) {
1583: prompt = packet_get_string(NULL);
1584: echo = packet_get_char();
1585:
1.77 markus 1586: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1587:
1.49 markus 1588: packet_put_cstring(response);
1.23 markus 1589: memset(response, 0, strlen(response));
1590: xfree(response);
1591: xfree(prompt);
1592: }
1.90 markus 1593: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1594:
1.85 markus 1595: packet_add_padding(64);
1.23 markus 1596: packet_send();
1.68 markus 1597: }
1598:
1.100 markus 1599: static int
1.105 deraadt 1600: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1601: u_char *data, u_int datalen)
1602: {
1603: Buffer b;
1.101 markus 1604: struct stat st;
1.100 markus 1605: pid_t pid;
1.103 markus 1606: int to[2], from[2], status, version = 2;
1.100 markus 1607:
1.109 markus 1608: debug2("ssh_keysign called");
1.100 markus 1609:
1.101 markus 1610: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.179 dtucker 1611: error("ssh_keysign: not installed: %s", strerror(errno));
1.101 markus 1612: return -1;
1613: }
1.100 markus 1614: if (fflush(stdout) != 0)
1615: error("ssh_keysign: fflush: %s", strerror(errno));
1616: if (pipe(to) < 0) {
1617: error("ssh_keysign: pipe: %s", strerror(errno));
1618: return -1;
1619: }
1620: if (pipe(from) < 0) {
1621: error("ssh_keysign: pipe: %s", strerror(errno));
1622: return -1;
1623: }
1624: if ((pid = fork()) < 0) {
1625: error("ssh_keysign: fork: %s", strerror(errno));
1626: return -1;
1627: }
1628: if (pid == 0) {
1.174 dtucker 1629: /* keep the socket on exec */
1630: fcntl(packet_get_connection_in(), F_SETFD, 0);
1.155 markus 1631: permanently_drop_suid(getuid());
1.100 markus 1632: close(from[0]);
1633: if (dup2(from[1], STDOUT_FILENO) < 0)
1634: fatal("ssh_keysign: dup2: %s", strerror(errno));
1635: close(to[1]);
1636: if (dup2(to[0], STDIN_FILENO) < 0)
1637: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1638: close(from[1]);
1639: close(to[0]);
1.102 markus 1640: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1641: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1642: strerror(errno));
1643: }
1644: close(from[1]);
1645: close(to[0]);
1646:
1647: buffer_init(&b);
1.103 markus 1648: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1649: buffer_put_string(&b, data, datalen);
1.131 djm 1650: if (ssh_msg_send(to[1], version, &b) == -1)
1651: fatal("ssh_keysign: couldn't send request");
1.100 markus 1652:
1.110 djm 1653: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1654: error("ssh_keysign: no reply");
1.134 markus 1655: buffer_free(&b);
1.100 markus 1656: return -1;
1657: }
1.101 markus 1658: close(from[0]);
1659: close(to[1]);
1660:
1.103 markus 1661: while (waitpid(pid, &status, 0) < 0)
1662: if (errno != EINTR)
1663: break;
1.101 markus 1664:
1.100 markus 1665: if (buffer_get_char(&b) != version) {
1.101 markus 1666: error("ssh_keysign: bad version");
1.134 markus 1667: buffer_free(&b);
1.100 markus 1668: return -1;
1669: }
1670: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1671: buffer_free(&b);
1.100 markus 1672:
1673: return 0;
1674: }
1675:
1.68 markus 1676: int
1677: userauth_hostbased(Authctxt *authctxt)
1678: {
1679: Key *private = NULL;
1.100 markus 1680: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1681: Buffer b;
1682: u_char *signature, *blob;
1.179 dtucker 1683: char *chost, *pkalg, *p;
1.72 markus 1684: const char *service;
1.68 markus 1685: u_int blen, slen;
1.176 dtucker 1686: int ok, i, found = 0;
1.68 markus 1687:
1688: /* check for a useful key */
1.100 markus 1689: for (i = 0; i < sensitive->nkeys; i++) {
1690: private = sensitive->keys[i];
1.68 markus 1691: if (private && private->type != KEY_RSA1) {
1692: found = 1;
1693: /* we take and free the key */
1.100 markus 1694: sensitive->keys[i] = NULL;
1.68 markus 1695: break;
1696: }
1697: }
1698: if (!found) {
1.109 markus 1699: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1700: return 0;
1701: }
1702: if (key_to_blob(private, &blob, &blen) == 0) {
1703: key_free(private);
1704: return 0;
1705: }
1.84 markus 1706: /* figure out a name for the client host */
1.179 dtucker 1707: p = get_local_name(packet_get_connection_in());
1.84 markus 1708: if (p == NULL) {
1709: error("userauth_hostbased: cannot get local ipaddr/name");
1710: key_free(private);
1.148 djm 1711: xfree(blob);
1.84 markus 1712: return 0;
1713: }
1.150 djm 1714: xasprintf(&chost, "%s.", p);
1.84 markus 1715: debug2("userauth_hostbased: chost %s", chost);
1.112 markus 1716: xfree(p);
1.84 markus 1717:
1.72 markus 1718: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1719: authctxt->service;
1.68 markus 1720: pkalg = xstrdup(key_ssh_name(private));
1721: buffer_init(&b);
1722: /* construct data */
1.72 markus 1723: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1724: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1725: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1726: buffer_put_cstring(&b, service);
1.68 markus 1727: buffer_put_cstring(&b, authctxt->method->name);
1728: buffer_put_cstring(&b, pkalg);
1729: buffer_put_string(&b, blob, blen);
1730: buffer_put_cstring(&b, chost);
1731: buffer_put_cstring(&b, authctxt->local_user);
1732: #ifdef DEBUG_PK
1733: buffer_dump(&b);
1734: #endif
1.100 markus 1735: if (sensitive->external_keysign)
1736: ok = ssh_keysign(private, &signature, &slen,
1737: buffer_ptr(&b), buffer_len(&b));
1738: else
1739: ok = key_sign(private, &signature, &slen,
1740: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1741: key_free(private);
1742: buffer_free(&b);
1743: if (ok != 0) {
1744: error("key_sign failed");
1745: xfree(chost);
1746: xfree(pkalg);
1.148 djm 1747: xfree(blob);
1.68 markus 1748: return 0;
1749: }
1750: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1751: packet_put_cstring(authctxt->server_user);
1752: packet_put_cstring(authctxt->service);
1753: packet_put_cstring(authctxt->method->name);
1754: packet_put_cstring(pkalg);
1755: packet_put_string(blob, blen);
1756: packet_put_cstring(chost);
1757: packet_put_cstring(authctxt->local_user);
1758: packet_put_string(signature, slen);
1759: memset(signature, 's', slen);
1760: xfree(signature);
1761: xfree(chost);
1762: xfree(pkalg);
1.148 djm 1763: xfree(blob);
1.68 markus 1764:
1765: packet_send();
1766: return 1;
1.23 markus 1767: }
1.20 markus 1768:
1.170 djm 1769: #ifdef JPAKE
1770: int
1771: userauth_jpake(Authctxt *authctxt)
1772: {
1773: struct jpake_ctx *pctx;
1774: u_char *x1_proof, *x2_proof;
1775: u_int x1_proof_len, x2_proof_len;
1776: static int attempt = 0; /* XXX share with userauth_password's? */
1777:
1778: if (attempt++ >= options.number_of_password_prompts)
1779: return 0;
1780: if (attempt != 1)
1781: error("Permission denied, please try again.");
1782:
1783: if (authctxt->methoddata != NULL)
1784: fatal("%s: authctxt->methoddata already set (%p)",
1785: __func__, authctxt->methoddata);
1786:
1787: authctxt->methoddata = pctx = jpake_new();
1788:
1789: /*
1790: * Send request immediately, to get the protocol going while
1791: * we do the initial computations.
1792: */
1793: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1794: packet_put_cstring(authctxt->server_user);
1795: packet_put_cstring(authctxt->service);
1796: packet_put_cstring(authctxt->method->name);
1797: packet_send();
1798: packet_write_wait();
1799:
1800: jpake_step1(pctx->grp,
1801: &pctx->client_id, &pctx->client_id_len,
1802: &pctx->x1, &pctx->x2, &pctx->g_x1, &pctx->g_x2,
1803: &x1_proof, &x1_proof_len,
1804: &x2_proof, &x2_proof_len);
1805:
1806: JPAKE_DEBUG_CTX((pctx, "step 1 sending in %s", __func__));
1807:
1808: packet_start(SSH2_MSG_USERAUTH_JPAKE_CLIENT_STEP1);
1809: packet_put_string(pctx->client_id, pctx->client_id_len);
1810: packet_put_bignum2(pctx->g_x1);
1811: packet_put_bignum2(pctx->g_x2);
1812: packet_put_string(x1_proof, x1_proof_len);
1813: packet_put_string(x2_proof, x2_proof_len);
1814: packet_send();
1815:
1816: bzero(x1_proof, x1_proof_len);
1817: bzero(x2_proof, x2_proof_len);
1818: xfree(x1_proof);
1819: xfree(x2_proof);
1820:
1821: /* Expect step 1 packet from peer */
1822: dispatch_set(SSH2_MSG_USERAUTH_JPAKE_SERVER_STEP1,
1823: input_userauth_jpake_server_step1);
1.172 djm 1824: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS,
1825: &input_userauth_success_unexpected);
1.170 djm 1826:
1827: return 1;
1828: }
1829:
1830: void
1831: userauth_jpake_cleanup(Authctxt *authctxt)
1832: {
1833: debug3("%s: clean up", __func__);
1834: if (authctxt->methoddata != NULL) {
1835: jpake_free(authctxt->methoddata);
1836: authctxt->methoddata = NULL;
1837: }
1.172 djm 1838: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
1.170 djm 1839: }
1840: #endif /* JPAKE */
1841:
1.20 markus 1842: /* find auth method */
1843:
1844: /*
1845: * given auth method name, if configurable options permit this method fill
1846: * in auth_ident field and return true, otherwise return false.
1847: */
1.76 itojun 1848: static int
1.20 markus 1849: authmethod_is_enabled(Authmethod *method)
1850: {
1851: if (method == NULL)
1852: return 0;
1853: /* return false if options indicate this method is disabled */
1854: if (method->enabled == NULL || *method->enabled == 0)
1855: return 0;
1856: /* return false if batch mode is enabled but method needs interactive mode */
1857: if (method->batch_flag != NULL && *method->batch_flag != 0)
1858: return 0;
1859: return 1;
1860: }
1861:
1.76 itojun 1862: static Authmethod *
1.20 markus 1863: authmethod_lookup(const char *name)
1.1 markus 1864: {
1.20 markus 1865: Authmethod *method = NULL;
1866: if (name != NULL)
1867: for (method = authmethods; method->name != NULL; method++)
1868: if (strcmp(name, method->name) == 0)
1869: return method;
1870: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1871: return NULL;
1872: }
1.1 markus 1873:
1.53 markus 1874: /* XXX internal state */
1875: static Authmethod *current = NULL;
1876: static char *supported = NULL;
1877: static char *preferred = NULL;
1.105 deraadt 1878:
1.20 markus 1879: /*
1880: * Given the authentication method list sent by the server, return the
1881: * next method we should try. If the server initially sends a nil list,
1.67 markus 1882: * use a built-in default list.
1.41 stevesk 1883: */
1.76 itojun 1884: static Authmethod *
1.20 markus 1885: authmethod_get(char *authlist)
1886: {
1.53 markus 1887: char *name = NULL;
1.97 markus 1888: u_int next;
1.41 stevesk 1889:
1.20 markus 1890: /* Use a suitable default if we're passed a nil list. */
1891: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1892: authlist = options.preferred_authentications;
1.20 markus 1893:
1.53 markus 1894: if (supported == NULL || strcmp(authlist, supported) != 0) {
1895: debug3("start over, passed a different list %s", authlist);
1896: if (supported != NULL)
1897: xfree(supported);
1898: supported = xstrdup(authlist);
1899: preferred = options.preferred_authentications;
1900: debug3("preferred %s", preferred);
1901: current = NULL;
1902: } else if (current != NULL && authmethod_is_enabled(current))
1903: return current;
1.20 markus 1904:
1.53 markus 1905: for (;;) {
1906: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1907: debug("No more authentication methods to try.");
1.53 markus 1908: current = NULL;
1909: return NULL;
1910: }
1911: preferred += next;
1.23 markus 1912: debug3("authmethod_lookup %s", name);
1.53 markus 1913: debug3("remaining preferred: %s", preferred);
1914: if ((current = authmethod_lookup(name)) != NULL &&
1915: authmethod_is_enabled(current)) {
1.23 markus 1916: debug3("authmethod_is_enabled %s", name);
1.109 markus 1917: debug("Next authentication method: %s", name);
1.187 djm 1918: xfree(name);
1.53 markus 1919: return current;
1.23 markus 1920: }
1.1 markus 1921: }
1.53 markus 1922: }
1.1 markus 1923:
1.79 stevesk 1924: static char *
1.53 markus 1925: authmethods_get(void)
1926: {
1927: Authmethod *method = NULL;
1.93 markus 1928: Buffer b;
1929: char *list;
1.27 provos 1930:
1.93 markus 1931: buffer_init(&b);
1.53 markus 1932: for (method = authmethods; method->name != NULL; method++) {
1933: if (authmethod_is_enabled(method)) {
1.93 markus 1934: if (buffer_len(&b) > 0)
1935: buffer_append(&b, ",", 1);
1936: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1937: }
1938: }
1.93 markus 1939: buffer_append(&b, "\0", 1);
1940: list = xstrdup(buffer_ptr(&b));
1941: buffer_free(&b);
1942: return list;
1.1 markus 1943: }
1.170 djm 1944:
![[BACK]](/icons/back.gif){kind=icon}
Return to sshconnect2.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh