Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.215
1.215 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.214 2015/01/14 20:05:27 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"
1.210 millert 58: #include "misc.h"
1.37 markus 59: #include "readconf.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"
1.214 djm 67: #include "ssherr.h"
1.22 provos 68:
1.121 markus 69: #ifdef GSSAPI
70: #include "ssh-gss.h"
71: #endif
72:
1.1 markus 73: /* import */
74: extern char *client_version_string;
75: extern char *server_version_string;
76: extern Options options;
77:
78: /*
79: * SSH2 key exchange
80: */
81:
1.32 markus 82: u_char *session_id2 = NULL;
1.120 markus 83: u_int session_id2_len = 0;
1.1 markus 84:
1.61 markus 85: char *xxx_host;
86: struct sockaddr *xxx_hostaddr;
87:
1.63 markus 88: Kex *xxx_kex = NULL;
89:
1.76 itojun 90: static int
1.75 markus 91: verify_host_key_callback(Key *hostkey)
1.61 markus 92: {
1.75 markus 93: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 94: fatal("Host key verification failed.");
1.61 markus 95: return 0;
96: }
97:
1.186 djm 98: static char *
99: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
100: {
101: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
102: size_t maxlen;
103: struct hostkeys *hostkeys;
104: int ktype;
1.188 djm 105: u_int i;
1.186 djm 106:
107: /* Find all hostkeys for this hostname */
108: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
109: hostkeys = init_hostkeys();
1.188 djm 110: for (i = 0; i < options.num_user_hostfiles; i++)
111: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
112: for (i = 0; i < options.num_system_hostfiles; i++)
113: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 114:
115: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
116: maxlen = strlen(avail) + 1;
117: first = xmalloc(maxlen);
118: last = xmalloc(maxlen);
119: *first = *last = '\0';
120:
121: #define ALG_APPEND(to, from) \
122: do { \
123: if (*to != '\0') \
124: strlcat(to, ",", maxlen); \
125: strlcat(to, from, maxlen); \
126: } while (0)
127:
128: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 129: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 130: fatal("%s: unknown alg %s", __func__, alg);
131: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 132: sshkey_type_plain(ktype), NULL))
1.186 djm 133: ALG_APPEND(first, alg);
134: else
135: ALG_APPEND(last, alg);
136: }
137: #undef ALG_APPEND
138: xasprintf(&ret, "%s%s%s", first, *first == '\0' ? "" : ",", last);
139: if (*first != '\0')
140: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
141:
1.197 djm 142: free(first);
143: free(last);
144: free(hostname);
145: free(oavail);
1.186 djm 146: free_hostkeys(hostkeys);
147:
148: return ret;
149: }
150:
1.1 markus 151: void
1.186 djm 152: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 153: {
1.205 markus 154: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.22 provos 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] =
1.200 djm 185: compat_pkalg_proposal(options.hostkeyalgorithms);
1.186 djm 186: else {
187: /* Prefer algorithms that we already have keys for */
188: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 189: compat_pkalg_proposal(
190: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 191: }
1.185 djm 192: if (options.kex_algorithms != NULL)
193: myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
1.206 djm 194: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
195: myproposal[PROPOSAL_KEX_ALGS]);
1.115 markus 196:
1.196 dtucker 197: if (options.rekey_limit || options.rekey_interval)
198: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
199: (time_t)options.rekey_interval);
1.22 provos 200:
1.65 markus 201: /* start key exchange */
1.64 markus 202: kex = kex_setup(myproposal);
1.207 markus 203: #ifdef WITH_OPENSSL
1.111 markus 204: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 205: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 206: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 207: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 208: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.207 markus 209: #endif
1.199 markus 210: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 211: kex->client_version_string=client_version_string;
212: kex->server_version_string=server_version_string;
1.75 markus 213: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 214:
215: xxx_kex = kex;
1.22 provos 216:
1.66 markus 217: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.173 andreas 218:
219: if (options.use_roaming && !kex->roaming) {
220: debug("Roaming not allowed by server");
221: options.use_roaming = 0;
222: }
1.62 markus 223:
224: session_id2 = kex->session_id;
225: session_id2_len = kex->session_id_len;
1.22 provos 226:
227: #ifdef DEBUG_KEXDH
228: /* send 1st encrypted/maced/compressed message */
229: packet_start(SSH2_MSG_IGNORE);
230: packet_put_cstring("markus");
231: packet_send();
232: packet_write_wait();
233: #endif
1.1 markus 234: }
1.11 markus 235:
1.1 markus 236: /*
237: * Authenticate user
238: */
1.20 markus 239:
1.214 djm 240: typedef struct cauthctxt Authctxt;
241: typedef struct cauthmethod Authmethod;
1.117 markus 242: typedef struct identity Identity;
243: typedef struct idlist Idlist;
1.20 markus 244:
1.117 markus 245: struct identity {
246: TAILQ_ENTRY(identity) next;
1.214 djm 247: int agent_fd; /* >=0 if agent supports key */
248: struct sshkey *key; /* public/private key */
1.117 markus 249: char *filename; /* comment for agent-only keys */
250: int tried;
251: int isprivate; /* key points to the private key */
1.191 dtucker 252: int userprovided;
1.117 markus 253: };
254: TAILQ_HEAD(idlist, identity);
1.20 markus 255:
1.214 djm 256: struct cauthctxt {
1.20 markus 257: const char *server_user;
1.68 markus 258: const char *local_user;
1.20 markus 259: const char *host;
260: const char *service;
1.214 djm 261: struct cauthmethod *method;
1.183 djm 262: sig_atomic_t success;
1.51 markus 263: char *authlist;
1.214 djm 264: int attempt;
1.68 markus 265: /* pubkey */
1.214 djm 266: struct idlist keys;
267: int agent_fd;
1.68 markus 268: /* hostbased */
1.100 markus 269: Sensitive *sensitive;
1.82 markus 270: /* kbd-interactive */
271: int info_req_seen;
1.121 markus 272: /* generic */
273: void *methoddata;
1.20 markus 274: };
1.214 djm 275:
276: struct cauthmethod {
1.20 markus 277: char *name; /* string to compare against server's list */
278: int (*userauth)(Authctxt *authctxt);
1.170 djm 279: void (*cleanup)(Authctxt *authctxt);
1.20 markus 280: int *enabled; /* flag in option struct that enables method */
281: int *batch_flag; /* flag in option struct that disables method */
282: };
283:
1.92 markus 284: void input_userauth_success(int, u_int32_t, void *);
1.172 djm 285: void input_userauth_success_unexpected(int, u_int32_t, void *);
1.92 markus 286: void input_userauth_failure(int, u_int32_t, void *);
287: void input_userauth_banner(int, u_int32_t, void *);
288: void input_userauth_error(int, u_int32_t, void *);
289: void input_userauth_info_req(int, u_int32_t, void *);
290: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 291: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 292:
293: int userauth_none(Authctxt *);
294: int userauth_pubkey(Authctxt *);
295: int userauth_passwd(Authctxt *);
296: int userauth_kbdint(Authctxt *);
297: int userauth_hostbased(Authctxt *);
1.20 markus 298:
1.121 markus 299: #ifdef GSSAPI
300: int userauth_gssapi(Authctxt *authctxt);
301: void input_gssapi_response(int type, u_int32_t, void *);
302: void input_gssapi_token(int type, u_int32_t, void *);
303: void input_gssapi_hash(int type, u_int32_t, void *);
304: void input_gssapi_error(int, u_int32_t, void *);
305: void input_gssapi_errtok(int, u_int32_t, void *);
306: #endif
307:
1.86 itojun 308: void userauth(Authctxt *, char *);
1.51 markus 309:
1.117 markus 310: static int sign_and_send_pubkey(Authctxt *, Identity *);
311: static void pubkey_prepare(Authctxt *);
312: static void pubkey_cleanup(Authctxt *);
1.191 dtucker 313: static Key *load_identity_file(char *, int);
1.76 itojun 314:
315: static Authmethod *authmethod_get(char *authlist);
316: static Authmethod *authmethod_lookup(const char *name);
317: static char *authmethods_get(void);
1.20 markus 318:
319: Authmethod authmethods[] = {
1.121 markus 320: #ifdef GSSAPI
1.132 markus 321: {"gssapi-with-mic",
1.121 markus 322: userauth_gssapi,
1.170 djm 323: NULL,
1.121 markus 324: &options.gss_authentication,
325: NULL},
326: #endif
1.81 markus 327: {"hostbased",
328: userauth_hostbased,
1.170 djm 329: NULL,
1.81 markus 330: &options.hostbased_authentication,
331: NULL},
1.20 markus 332: {"publickey",
333: userauth_pubkey,
1.170 djm 334: NULL,
1.28 markus 335: &options.pubkey_authentication,
1.20 markus 336: NULL},
1.81 markus 337: {"keyboard-interactive",
338: userauth_kbdint,
1.170 djm 339: NULL,
1.81 markus 340: &options.kbd_interactive_authentication,
341: &options.batch_mode},
1.20 markus 342: {"password",
343: userauth_passwd,
1.170 djm 344: NULL,
1.20 markus 345: &options.password_authentication,
1.23 markus 346: &options.batch_mode},
347: {"none",
348: userauth_none,
349: NULL,
1.170 djm 350: NULL,
1.23 markus 351: NULL},
1.170 djm 352: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 353: };
354:
355: void
1.68 markus 356: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 357: Sensitive *sensitive)
1.20 markus 358: {
359: Authctxt authctxt;
360: int type;
1.39 markus 361:
1.73 markus 362: if (options.challenge_response_authentication)
1.39 markus 363: options.kbd_interactive_authentication = 1;
1.20 markus 364:
365: packet_start(SSH2_MSG_SERVICE_REQUEST);
366: packet_put_cstring("ssh-userauth");
367: packet_send();
1.108 markus 368: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 369: packet_write_wait();
1.91 markus 370: type = packet_read();
1.108 markus 371: if (type != SSH2_MSG_SERVICE_ACCEPT)
372: fatal("Server denied authentication request: %d", type);
1.20 markus 373: if (packet_remaining() > 0) {
1.91 markus 374: char *reply = packet_get_string(NULL);
1.108 markus 375: debug2("service_accept: %s", reply);
1.197 djm 376: free(reply);
1.20 markus 377: } else {
1.109 markus 378: debug2("buggy server: service_accept w/o service");
1.20 markus 379: }
1.90 markus 380: packet_check_eom();
1.108 markus 381: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 382:
1.53 markus 383: if (options.preferred_authentications == NULL)
384: options.preferred_authentications = authmethods_get();
385:
1.20 markus 386: /* setup authentication context */
1.82 markus 387: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 388: pubkey_prepare(&authctxt);
1.20 markus 389: authctxt.server_user = server_user;
1.68 markus 390: authctxt.local_user = local_user;
1.20 markus 391: authctxt.host = host;
392: authctxt.service = "ssh-connection"; /* service name */
393: authctxt.success = 0;
1.23 markus 394: authctxt.method = authmethod_lookup("none");
1.51 markus 395: authctxt.authlist = NULL;
1.121 markus 396: authctxt.methoddata = NULL;
1.100 markus 397: authctxt.sensitive = sensitive;
1.82 markus 398: authctxt.info_req_seen = 0;
1.215 ! djm 399: authctxt.agent_fd = -1;
1.23 markus 400: if (authctxt.method == NULL)
401: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 402:
403: /* initial userauth request */
1.23 markus 404: userauth_none(&authctxt);
1.20 markus 405:
1.65 markus 406: dispatch_init(&input_userauth_error);
1.20 markus 407: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
408: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 409: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 410: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
411:
1.117 markus 412: pubkey_cleanup(&authctxt);
1.119 markus 413: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
414:
1.109 markus 415: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 416: }
1.119 markus 417:
1.20 markus 418: void
1.51 markus 419: userauth(Authctxt *authctxt, char *authlist)
420: {
1.170 djm 421: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
422: authctxt->method->cleanup(authctxt);
423:
1.197 djm 424: free(authctxt->methoddata);
425: authctxt->methoddata = NULL;
1.51 markus 426: if (authlist == NULL) {
427: authlist = authctxt->authlist;
428: } else {
1.197 djm 429: free(authctxt->authlist);
1.51 markus 430: authctxt->authlist = authlist;
431: }
432: for (;;) {
433: Authmethod *method = authmethod_get(authlist);
434: if (method == NULL)
435: fatal("Permission denied (%s).", authlist);
436: authctxt->method = method;
1.119 markus 437:
438: /* reset the per method handler */
439: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
440: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
441:
442: /* and try new method */
1.51 markus 443: if (method->userauth(authctxt) != 0) {
444: debug2("we sent a %s packet, wait for reply", method->name);
445: break;
446: } else {
447: debug2("we did not send a packet, disable method");
448: method->enabled = NULL;
449: }
450: }
451: }
1.105 deraadt 452:
1.169 djm 453: /* ARGSUSED */
1.51 markus 454: void
1.92 markus 455: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 456: {
1.35 markus 457: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 458: "type %d", type);
1.35 markus 459: }
1.105 deraadt 460:
1.169 djm 461: /* ARGSUSED */
1.35 markus 462: void
1.92 markus 463: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 464: {
1.166 djm 465: char *msg, *raw, *lang;
466: u_int len;
1.126 deraadt 467:
1.35 markus 468: debug3("input_userauth_banner");
1.166 djm 469: raw = packet_get_string(&len);
1.35 markus 470: lang = packet_get_string(NULL);
1.167 markus 471: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 472: if (len > 65536)
473: len = 65536;
1.168 deraadt 474: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 475: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 476: fprintf(stderr, "%s", msg);
1.197 djm 477: free(msg);
1.166 djm 478: }
1.197 djm 479: free(raw);
480: free(lang);
1.20 markus 481: }
1.105 deraadt 482:
1.169 djm 483: /* ARGSUSED */
1.20 markus 484: void
1.92 markus 485: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 486: {
487: Authctxt *authctxt = ctxt;
1.172 djm 488:
1.20 markus 489: if (authctxt == NULL)
490: fatal("input_userauth_success: no authentication context");
1.197 djm 491: free(authctxt->authlist);
492: authctxt->authlist = NULL;
1.172 djm 493: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
494: authctxt->method->cleanup(authctxt);
1.197 djm 495: free(authctxt->methoddata);
496: authctxt->methoddata = NULL;
1.20 markus 497: authctxt->success = 1; /* break out */
498: }
1.105 deraadt 499:
1.172 djm 500: void
501: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
502: {
503: Authctxt *authctxt = ctxt;
504:
505: if (authctxt == NULL)
506: fatal("%s: no authentication context", __func__);
507:
508: fatal("Unexpected authentication success during %s.",
509: authctxt->method->name);
510: }
511:
1.169 djm 512: /* ARGSUSED */
1.20 markus 513: void
1.92 markus 514: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 515: {
516: Authctxt *authctxt = ctxt;
517: char *authlist = NULL;
518: int partial;
519:
520: if (authctxt == NULL)
521: fatal("input_userauth_failure: no authentication context");
522:
1.23 markus 523: authlist = packet_get_string(NULL);
1.20 markus 524: partial = packet_get_char();
1.90 markus 525: packet_check_eom();
1.20 markus 526:
1.193 markus 527: if (partial != 0) {
1.116 itojun 528: logit("Authenticated with partial success.");
1.193 markus 529: /* reset state */
530: pubkey_cleanup(authctxt);
531: pubkey_prepare(authctxt);
532: }
1.109 markus 533: debug("Authentications that can continue: %s", authlist);
1.20 markus 534:
1.51 markus 535: userauth(authctxt, authlist);
536: }
1.169 djm 537:
538: /* ARGSUSED */
1.51 markus 539: void
1.92 markus 540: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 541: {
542: Authctxt *authctxt = ctxt;
543: Key *key = NULL;
1.117 markus 544: Identity *id = NULL;
1.51 markus 545: Buffer b;
1.96 markus 546: int pktype, sent = 0;
547: u_int alen, blen;
548: char *pkalg, *fp;
549: u_char *pkblob;
1.51 markus 550:
551: if (authctxt == NULL)
552: fatal("input_userauth_pk_ok: no authentication context");
553: if (datafellows & SSH_BUG_PKOK) {
554: /* this is similar to SSH_BUG_PKAUTH */
555: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
556: pkblob = packet_get_string(&blen);
557: buffer_init(&b);
558: buffer_append(&b, pkblob, blen);
559: pkalg = buffer_get_string(&b, &alen);
560: buffer_free(&b);
561: } else {
562: pkalg = packet_get_string(&alen);
563: pkblob = packet_get_string(&blen);
564: }
1.90 markus 565: packet_check_eom();
1.51 markus 566:
1.117 markus 567: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 568:
1.117 markus 569: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
570: debug("unknown pkalg %s", pkalg);
571: goto done;
572: }
573: if ((key = key_from_blob(pkblob, blen)) == NULL) {
574: debug("no key from blob. pkalg %s", pkalg);
575: goto done;
576: }
577: if (key->type != pktype) {
578: error("input_userauth_pk_ok: type mismatch "
579: "for decoded key (received %d, expected %d)",
580: key->type, pktype);
581: goto done;
582: }
1.214 djm 583: fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_DEFAULT);
1.117 markus 584: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 585: free(fp);
1.117 markus 586:
1.127 markus 587: /*
588: * search keys in the reverse order, because last candidate has been
589: * moved to the end of the queue. this also avoids confusion by
590: * duplicate keys
591: */
1.136 henning 592: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 593: if (key_equal(key, id->key)) {
594: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 595: break;
596: }
1.117 markus 597: }
598: done:
1.51 markus 599: if (key != NULL)
600: key_free(key);
1.197 djm 601: free(pkalg);
602: free(pkblob);
1.51 markus 603:
1.106 deraadt 604: /* try another method if we did not send a packet */
1.51 markus 605: if (sent == 0)
606: userauth(authctxt, NULL);
1.20 markus 607: }
1.121 markus 608:
609: #ifdef GSSAPI
1.133 djm 610: int
1.121 markus 611: userauth_gssapi(Authctxt *authctxt)
612: {
613: Gssctxt *gssctxt = NULL;
1.128 avsm 614: static gss_OID_set gss_supported = NULL;
1.139 djm 615: static u_int mech = 0;
1.121 markus 616: OM_uint32 min;
617: int ok = 0;
618:
619: /* Try one GSSAPI method at a time, rather than sending them all at
620: * once. */
621:
1.128 avsm 622: if (gss_supported == NULL)
623: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 624:
625: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 626: while (mech < gss_supported->count && !ok) {
1.121 markus 627: /* My DER encoding requires length<128 */
1.128 avsm 628: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 629: ssh_gssapi_check_mechanism(&gssctxt,
630: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 631: ok = 1; /* Mechanism works */
632: } else {
633: mech++;
634: }
635: }
636:
1.161 djm 637: if (!ok)
1.139 djm 638: return 0;
1.121 markus 639:
640: authctxt->methoddata=(void *)gssctxt;
641:
642: packet_start(SSH2_MSG_USERAUTH_REQUEST);
643: packet_put_cstring(authctxt->server_user);
644: packet_put_cstring(authctxt->service);
645: packet_put_cstring(authctxt->method->name);
646:
647: packet_put_int(1);
648:
1.129 markus 649: packet_put_int((gss_supported->elements[mech].length) + 2);
650: packet_put_char(SSH_GSS_OIDTYPE);
651: packet_put_char(gss_supported->elements[mech].length);
652: packet_put_raw(gss_supported->elements[mech].elements,
653: gss_supported->elements[mech].length);
1.121 markus 654:
655: packet_send();
656:
657: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
658: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
659: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
660: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
661:
662: mech++; /* Move along to next candidate */
663:
664: return 1;
665: }
666:
1.130 markus 667: static OM_uint32
668: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
669: {
670: Authctxt *authctxt = ctxt;
671: Gssctxt *gssctxt = authctxt->methoddata;
672: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 673: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
674: gss_buffer_desc gssbuf;
1.132 markus 675: OM_uint32 status, ms, flags;
676: Buffer b;
1.133 djm 677:
1.130 markus 678: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 679: recv_tok, &send_tok, &flags);
1.130 markus 680:
681: if (send_tok.length > 0) {
682: if (GSS_ERROR(status))
683: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
684: else
685: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 686:
1.130 markus 687: packet_put_string(send_tok.value, send_tok.length);
688: packet_send();
689: gss_release_buffer(&ms, &send_tok);
690: }
1.133 djm 691:
1.130 markus 692: if (status == GSS_S_COMPLETE) {
1.132 markus 693: /* send either complete or MIC, depending on mechanism */
694: if (!(flags & GSS_C_INTEG_FLAG)) {
695: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
696: packet_send();
697: } else {
698: ssh_gssapi_buildmic(&b, authctxt->server_user,
699: authctxt->service, "gssapi-with-mic");
700:
701: gssbuf.value = buffer_ptr(&b);
702: gssbuf.length = buffer_len(&b);
1.133 djm 703:
1.132 markus 704: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 705:
1.132 markus 706: if (!GSS_ERROR(status)) {
707: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
708: packet_put_string(mic.value, mic.length);
1.133 djm 709:
1.132 markus 710: packet_send();
711: }
1.133 djm 712:
1.132 markus 713: buffer_free(&b);
714: gss_release_buffer(&ms, &mic);
1.133 djm 715: }
1.130 markus 716: }
1.133 djm 717:
1.130 markus 718: return status;
719: }
720:
1.169 djm 721: /* ARGSUSED */
1.121 markus 722: void
723: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
724: {
725: Authctxt *authctxt = ctxt;
726: Gssctxt *gssctxt;
727: int oidlen;
728: char *oidv;
729:
730: if (authctxt == NULL)
731: fatal("input_gssapi_response: no authentication context");
732: gssctxt = authctxt->methoddata;
733:
734: /* Setup our OID */
735: oidv = packet_get_string(&oidlen);
736:
1.129 markus 737: if (oidlen <= 2 ||
738: oidv[0] != SSH_GSS_OIDTYPE ||
739: oidv[1] != oidlen - 2) {
1.197 djm 740: free(oidv);
1.129 markus 741: debug("Badly encoded mechanism OID received");
742: userauth(authctxt, NULL);
743: return;
1.121 markus 744: }
1.129 markus 745:
746: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
747: fatal("Server returned different OID than expected");
1.121 markus 748:
749: packet_check_eom();
750:
1.197 djm 751: free(oidv);
1.121 markus 752:
1.130 markus 753: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 754: /* Start again with next method on list */
755: debug("Trying to start again");
756: userauth(authctxt, NULL);
757: return;
758: }
759: }
760:
1.169 djm 761: /* ARGSUSED */
1.121 markus 762: void
763: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
764: {
765: Authctxt *authctxt = ctxt;
766: gss_buffer_desc recv_tok;
1.130 markus 767: OM_uint32 status;
1.121 markus 768: u_int slen;
769:
770: if (authctxt == NULL)
771: fatal("input_gssapi_response: no authentication context");
772:
773: recv_tok.value = packet_get_string(&slen);
774: recv_tok.length = slen; /* safe typecast */
775:
776: packet_check_eom();
777:
1.130 markus 778: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 779:
1.197 djm 780: free(recv_tok.value);
1.121 markus 781:
782: if (GSS_ERROR(status)) {
783: /* Start again with the next method in the list */
784: userauth(authctxt, NULL);
785: return;
786: }
787: }
788:
1.169 djm 789: /* ARGSUSED */
1.121 markus 790: void
791: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
792: {
793: Authctxt *authctxt = ctxt;
794: Gssctxt *gssctxt;
795: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
796: gss_buffer_desc recv_tok;
1.194 djm 797: OM_uint32 ms;
1.123 deraadt 798: u_int len;
1.121 markus 799:
800: if (authctxt == NULL)
801: fatal("input_gssapi_response: no authentication context");
802: gssctxt = authctxt->methoddata;
803:
1.123 deraadt 804: recv_tok.value = packet_get_string(&len);
805: recv_tok.length = len;
1.121 markus 806:
807: packet_check_eom();
808:
809: /* Stick it into GSSAPI and see what it says */
1.194 djm 810: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 811: &recv_tok, &send_tok, NULL);
1.121 markus 812:
1.197 djm 813: free(recv_tok.value);
1.121 markus 814: gss_release_buffer(&ms, &send_tok);
815:
816: /* Server will be returning a failed packet after this one */
817: }
818:
1.169 djm 819: /* ARGSUSED */
1.121 markus 820: void
821: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
822: {
823: char *msg;
824: char *lang;
825:
1.194 djm 826: /* maj */(void)packet_get_int();
827: /* min */(void)packet_get_int();
1.121 markus 828: msg=packet_get_string(NULL);
829: lang=packet_get_string(NULL);
830:
831: packet_check_eom();
832:
1.143 stevesk 833: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 834: free(msg);
835: free(lang);
1.121 markus 836: }
837: #endif /* GSSAPI */
1.20 markus 838:
1.1 markus 839: int
1.23 markus 840: userauth_none(Authctxt *authctxt)
841: {
842: /* initial userauth request */
843: packet_start(SSH2_MSG_USERAUTH_REQUEST);
844: packet_put_cstring(authctxt->server_user);
845: packet_put_cstring(authctxt->service);
846: packet_put_cstring(authctxt->method->name);
847: packet_send();
848: return 1;
849: }
850:
851: int
1.20 markus 852: userauth_passwd(Authctxt *authctxt)
1.1 markus 853: {
1.6 markus 854: static int attempt = 0;
1.99 markus 855: char prompt[150];
1.1 markus 856: char *password;
1.175 dtucker 857: const char *host = options.host_key_alias ? options.host_key_alias :
858: authctxt->host;
1.6 markus 859:
1.13 todd 860: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 861: return 0;
1.13 todd 862:
1.87 deraadt 863: if (attempt != 1)
1.13 todd 864: error("Permission denied, please try again.");
1.1 markus 865:
1.43 itojun 866: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 867: authctxt->server_user, host);
1.1 markus 868: password = read_passphrase(prompt, 0);
869: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 870: packet_put_cstring(authctxt->server_user);
871: packet_put_cstring(authctxt->service);
1.23 markus 872: packet_put_cstring(authctxt->method->name);
1.1 markus 873: packet_put_char(0);
1.49 markus 874: packet_put_cstring(password);
1.204 djm 875: explicit_bzero(password, strlen(password));
1.197 djm 876: free(password);
1.85 markus 877: packet_add_padding(64);
1.1 markus 878: packet_send();
1.99 markus 879:
1.104 deraadt 880: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 881: &input_userauth_passwd_changereq);
882:
1.1 markus 883: return 1;
884: }
1.169 djm 885:
1.99 markus 886: /*
887: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
888: */
1.169 djm 889: /* ARGSUSED */
1.99 markus 890: void
1.153 djm 891: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 892: {
893: Authctxt *authctxt = ctxt;
894: char *info, *lang, *password = NULL, *retype = NULL;
895: char prompt[150];
1.175 dtucker 896: const char *host = options.host_key_alias ? options.host_key_alias :
897: authctxt->host;
1.99 markus 898:
899: debug2("input_userauth_passwd_changereq");
900:
901: if (authctxt == NULL)
902: fatal("input_userauth_passwd_changereq: "
903: "no authentication context");
904:
905: info = packet_get_string(NULL);
906: lang = packet_get_string(NULL);
907: if (strlen(info) > 0)
1.116 itojun 908: logit("%s", info);
1.197 djm 909: free(info);
910: free(lang);
1.99 markus 911: packet_start(SSH2_MSG_USERAUTH_REQUEST);
912: packet_put_cstring(authctxt->server_user);
913: packet_put_cstring(authctxt->service);
914: packet_put_cstring(authctxt->method->name);
915: packet_put_char(1); /* additional info */
1.104 deraadt 916: snprintf(prompt, sizeof(prompt),
1.99 markus 917: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 918: authctxt->server_user, host);
1.99 markus 919: password = read_passphrase(prompt, 0);
920: packet_put_cstring(password);
1.204 djm 921: explicit_bzero(password, strlen(password));
1.197 djm 922: free(password);
1.99 markus 923: password = NULL;
924: while (password == NULL) {
1.104 deraadt 925: snprintf(prompt, sizeof(prompt),
1.99 markus 926: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 927: authctxt->server_user, host);
1.99 markus 928: password = read_passphrase(prompt, RP_ALLOW_EOF);
929: if (password == NULL) {
930: /* bail out */
931: return;
932: }
1.104 deraadt 933: snprintf(prompt, sizeof(prompt),
1.99 markus 934: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 935: authctxt->server_user, host);
1.99 markus 936: retype = read_passphrase(prompt, 0);
937: if (strcmp(password, retype) != 0) {
1.204 djm 938: explicit_bzero(password, strlen(password));
1.197 djm 939: free(password);
1.116 itojun 940: logit("Mismatch; try again, EOF to quit.");
1.99 markus 941: password = NULL;
942: }
1.204 djm 943: explicit_bzero(retype, strlen(retype));
1.197 djm 944: free(retype);
1.99 markus 945: }
946: packet_put_cstring(password);
1.204 djm 947: explicit_bzero(password, strlen(password));
1.197 djm 948: free(password);
1.99 markus 949: packet_add_padding(64);
950: packet_send();
1.104 deraadt 951:
952: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 953: &input_userauth_passwd_changereq);
1.117 markus 954: }
955:
956: static int
1.214 djm 957: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
958: const u_char *data, size_t datalen, u_int compat)
1.117 markus 959: {
960: Key *prv;
961: int ret;
1.99 markus 962:
1.117 markus 963: /* the agent supports this key */
1.214 djm 964: if (id->agent_fd)
965: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
966: data, datalen, compat);
967:
1.117 markus 968: /*
969: * we have already loaded the private key or
970: * the private key is stored in external hardware
971: */
1.209 djm 972: if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
1.214 djm 973: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
974: compat));
1.117 markus 975: /* load the private key from the file */
1.191 dtucker 976: if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
1.214 djm 977: return (-1); /* XXX return decent error code */
978: ret = sshkey_sign(prv, sigp, lenp, data, datalen, compat);
979: sshkey_free(prv);
1.117 markus 980: return (ret);
1.51 markus 981: }
982:
1.76 itojun 983: static int
1.117 markus 984: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 985: {
986: Buffer b;
1.32 markus 987: u_char *blob, *signature;
1.214 djm 988: u_int bloblen;
989: size_t slen;
1.120 markus 990: u_int skip = 0;
1.17 markus 991: int ret = -1;
1.23 markus 992: int have_sig = 1;
1.182 djm 993: char *fp;
1.1 markus 994:
1.212 djm 995: fp = key_fingerprint(id->key, options.fingerprint_hash, SSH_FP_DEFAULT);
1.182 djm 996: debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1.197 djm 997: free(fp);
1.51 markus 998:
1.117 markus 999: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1000: /* we cannot handle this key */
1.30 markus 1001: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1002: return 0;
1003: }
1.1 markus 1004: /* data to be signed */
1005: buffer_init(&b);
1.26 markus 1006: if (datafellows & SSH_OLD_SESSIONID) {
1007: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1008: skip = session_id2_len;
1.26 markus 1009: } else {
1.14 markus 1010: buffer_put_string(&b, session_id2, session_id2_len);
1011: skip = buffer_len(&b);
1012: }
1.1 markus 1013: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1014: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1015: buffer_put_cstring(&b,
1.30 markus 1016: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1017: "ssh-userauth" :
1.20 markus 1018: authctxt->service);
1.30 markus 1019: if (datafellows & SSH_BUG_PKAUTH) {
1020: buffer_put_char(&b, have_sig);
1021: } else {
1022: buffer_put_cstring(&b, authctxt->method->name);
1023: buffer_put_char(&b, have_sig);
1.117 markus 1024: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1025: }
1.1 markus 1026: buffer_put_string(&b, blob, bloblen);
1027:
1028: /* generate signature */
1.117 markus 1029: ret = identity_sign(id, &signature, &slen,
1.214 djm 1030: buffer_ptr(&b), buffer_len(&b), datafellows);
1031: if (ret != 0) {
1.197 djm 1032: free(blob);
1.17 markus 1033: buffer_free(&b);
1034: return 0;
1035: }
1.28 markus 1036: #ifdef DEBUG_PK
1.1 markus 1037: buffer_dump(&b);
1038: #endif
1.30 markus 1039: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1040: buffer_clear(&b);
1041: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1042: skip = session_id2_len;
1.10 markus 1043: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1044: buffer_put_cstring(&b, authctxt->server_user);
1045: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1046: buffer_put_cstring(&b, authctxt->method->name);
1047: buffer_put_char(&b, have_sig);
1.30 markus 1048: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1049: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1050: buffer_put_string(&b, blob, bloblen);
1051: }
1.197 djm 1052: free(blob);
1.51 markus 1053:
1.1 markus 1054: /* append signature */
1055: buffer_put_string(&b, signature, slen);
1.197 djm 1056: free(signature);
1.1 markus 1057:
1058: /* skip session id and packet type */
1.14 markus 1059: if (buffer_len(&b) < skip + 1)
1.20 markus 1060: fatal("userauth_pubkey: internal error");
1.14 markus 1061: buffer_consume(&b, skip + 1);
1.1 markus 1062:
1063: /* put remaining data from buffer into packet */
1064: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1065: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1066: buffer_free(&b);
1067: packet_send();
1.17 markus 1068:
1069: return 1;
1.16 markus 1070: }
1071:
1.76 itojun 1072: static int
1.117 markus 1073: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1074: {
1.51 markus 1075: u_char *blob;
1.97 markus 1076: u_int bloblen, have_sig = 0;
1.20 markus 1077:
1.51 markus 1078: debug3("send_pubkey_test");
1.16 markus 1079:
1.117 markus 1080: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1081: /* we cannot handle this key */
1082: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1083: return 0;
1084: }
1.51 markus 1085: /* register callback for USERAUTH_PK_OK message */
1086: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1087:
1088: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1089: packet_put_cstring(authctxt->server_user);
1090: packet_put_cstring(authctxt->service);
1091: packet_put_cstring(authctxt->method->name);
1092: packet_put_char(have_sig);
1093: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1094: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1095: packet_put_string(blob, bloblen);
1.197 djm 1096: free(blob);
1.51 markus 1097: packet_send();
1098: return 1;
1099: }
1100:
1.76 itojun 1101: static Key *
1.191 dtucker 1102: load_identity_file(char *filename, int userprovided)
1.51 markus 1103: {
1104: Key *private;
1105: char prompt[300], *passphrase;
1.215 ! djm 1106: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1107: struct stat st;
1.16 markus 1108:
1.52 markus 1109: if (stat(filename, &st) < 0) {
1.191 dtucker 1110: (userprovided ? logit : debug3)("no such identity: %s: %s",
1111: filename, strerror(errno));
1.52 markus 1112: return NULL;
1113: }
1.214 djm 1114: snprintf(prompt, sizeof prompt,
1115: "Enter passphrase for key '%.100s': ", filename);
1116: for (i = 0; i <= options.number_of_password_prompts; i++) {
1117: if (i == 0)
1118: passphrase = "";
1119: else {
1.20 markus 1120: passphrase = read_passphrase(prompt, 0);
1.214 djm 1121: if (*passphrase == '\0') {
1.20 markus 1122: debug2("no passphrase given, try next key");
1.214 djm 1123: free(passphrase);
1124: break;
1125: }
1126: }
1127: switch ((r = sshkey_load_private_type(KEY_UNSPEC, filename,
1128: passphrase, &private, NULL, &perm_ok))) {
1129: case 0:
1130: break;
1131: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1132: if (options.batch_mode) {
1133: quit = 1;
1134: break;
1135: }
1.215 ! djm 1136: if (i != 0)
! 1137: debug2("bad passphrase given, try again...");
1.214 djm 1138: break;
1139: case SSH_ERR_SYSTEM_ERROR:
1140: if (errno == ENOENT) {
1141: debug2("Load key \"%s\": %s",
1142: filename, ssh_err(r));
1.51 markus 1143: quit = 1;
1.214 djm 1144: break;
1.20 markus 1145: }
1.214 djm 1146: /* FALLTHROUGH */
1147: default:
1148: error("Load key \"%s\": %s", filename, ssh_err(r));
1149: quit = 1;
1150: break;
1151: }
1152: if (i > 0) {
1.204 djm 1153: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1154: free(passphrase);
1.16 markus 1155: }
1.214 djm 1156: if (private != NULL || quit)
1157: break;
1.16 markus 1158: }
1.51 markus 1159: return private;
1160: }
1161:
1.117 markus 1162: /*
1163: * try keys in the following order:
1164: * 1. agent keys that are found in the config file
1165: * 2. other agent keys
1166: * 3. keys that are only listed in the config file
1167: */
1168: static void
1169: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1170: {
1.214 djm 1171: struct identity *id, *id2, *tmp;
1172: struct idlist agent, files, *preferred;
1173: struct sshkey *key;
1174: int agent_fd, i, r, found;
1175: size_t j;
1176: struct ssh_identitylist *idlist;
1.51 markus 1177:
1.117 markus 1178: TAILQ_INIT(&agent); /* keys from the agent */
1179: TAILQ_INIT(&files); /* keys from the config file */
1180: preferred = &authctxt->keys;
1181: TAILQ_INIT(preferred); /* preferred order of keys */
1182:
1.190 djm 1183: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1184: for (i = 0; i < options.num_identity_files; i++) {
1185: key = options.identity_keys[i];
1186: if (key && key->type == KEY_RSA1)
1.180 djm 1187: continue;
1188: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1189: continue;
1190: options.identity_keys[i] = NULL;
1.150 djm 1191: id = xcalloc(1, sizeof(*id));
1.117 markus 1192: id->key = key;
1193: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1194: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1195: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1196: }
1197: /* Prefer PKCS11 keys that are explicitly listed */
1198: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1.209 djm 1199: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1200: continue;
1201: found = 0;
1202: TAILQ_FOREACH(id2, &files, next) {
1203: if (id2->key == NULL ||
1.209 djm 1204: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1205: continue;
1.214 djm 1206: if (sshkey_equal(id->key, id2->key)) {
1.190 djm 1207: TAILQ_REMOVE(&files, id, next);
1208: TAILQ_INSERT_TAIL(preferred, id, next);
1209: found = 1;
1210: break;
1211: }
1212: }
1213: /* If IdentitiesOnly set and key not found then don't use it */
1214: if (!found && options.identities_only) {
1215: TAILQ_REMOVE(&files, id, next);
1.203 tedu 1216: explicit_bzero(id, sizeof(*id));
1.190 djm 1217: free(id);
1218: }
1.117 markus 1219: }
1220: /* list of keys supported by the agent */
1.214 djm 1221: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1222: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1223: debug("%s: ssh_get_authentication_socket: %s",
1224: __func__, ssh_err(r));
1225: } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1226: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1227: debug("%s: ssh_fetch_identitylist: %s",
1228: __func__, ssh_err(r));
1229: } else {
1230: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1231: found = 0;
1232: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1233: /*
1234: * agent keys from the config file are
1235: * preferred
1236: */
1237: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1238: TAILQ_REMOVE(&files, id, next);
1239: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1240: id->agent_fd = agent_fd;
1.117 markus 1241: found = 1;
1242: break;
1243: }
1244: }
1.135 markus 1245: if (!found && !options.identities_only) {
1.150 djm 1246: id = xcalloc(1, sizeof(*id));
1.214 djm 1247: /* XXX "steals" key/comment from idlist */
1248: id->key = idlist->keys[j];
1249: id->filename = idlist->comments[j];
1250: idlist->keys[j] = NULL;
1251: idlist->comments[j] = NULL;
1252: id->agent_fd = agent_fd;
1.117 markus 1253: TAILQ_INSERT_TAIL(&agent, id, next);
1254: }
1255: }
1.214 djm 1256: ssh_free_identitylist(idlist);
1.117 markus 1257: /* append remaining agent keys */
1258: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1259: TAILQ_REMOVE(&agent, id, next);
1260: TAILQ_INSERT_TAIL(preferred, id, next);
1261: }
1.214 djm 1262: authctxt->agent_fd = agent_fd;
1.117 markus 1263: }
1264: /* append remaining keys from the config file */
1265: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1266: TAILQ_REMOVE(&files, id, next);
1267: TAILQ_INSERT_TAIL(preferred, id, next);
1268: }
1269: TAILQ_FOREACH(id, preferred, next) {
1.191 dtucker 1270: debug2("key: %s (%p),%s", id->filename, id->key,
1271: id->userprovided ? " explicit" : "");
1.117 markus 1272: }
1.17 markus 1273: }
1274:
1.117 markus 1275: static void
1276: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1277: {
1.117 markus 1278: Identity *id;
1.51 markus 1279:
1.214 djm 1280: if (authctxt->agent_fd != -1)
1281: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1282: for (id = TAILQ_FIRST(&authctxt->keys); id;
1283: id = TAILQ_FIRST(&authctxt->keys)) {
1284: TAILQ_REMOVE(&authctxt->keys, id, next);
1285: if (id->key)
1.214 djm 1286: sshkey_free(id->key);
1.197 djm 1287: free(id->filename);
1288: free(id);
1.117 markus 1289: }
1.1 markus 1290: }
1291:
1.20 markus 1292: int
1293: userauth_pubkey(Authctxt *authctxt)
1294: {
1.117 markus 1295: Identity *id;
1.20 markus 1296: int sent = 0;
1297:
1.117 markus 1298: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1299: if (id->tried++)
1300: return (0);
1.127 markus 1301: /* move key to the end of the queue */
1.117 markus 1302: TAILQ_REMOVE(&authctxt->keys, id, next);
1303: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1304: /*
1305: * send a test message if we have the public key. for
1306: * encrypted keys we cannot do this and have to load the
1307: * private key instead
1308: */
1.200 djm 1309: if (id->key != NULL) {
1310: if (key_type_plain(id->key->type) == KEY_RSA &&
1311: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1312: debug("Skipped %s key %s for RSA/MD5 server",
1313: key_type(id->key), id->filename);
1314: } else if (id->key->type != KEY_RSA1) {
1315: debug("Offering %s public key: %s",
1316: key_type(id->key), id->filename);
1317: sent = send_pubkey_test(authctxt, id);
1318: }
1319: } else {
1.117 markus 1320: debug("Trying private key: %s", id->filename);
1.191 dtucker 1321: id->key = load_identity_file(id->filename,
1322: id->userprovided);
1.117 markus 1323: if (id->key != NULL) {
1324: id->isprivate = 1;
1.200 djm 1325: if (key_type_plain(id->key->type) == KEY_RSA &&
1326: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1327: debug("Skipped %s key %s for RSA/MD5 "
1328: "server", key_type(id->key),
1329: id->filename);
1330: } else {
1331: sent = sign_and_send_pubkey(
1332: authctxt, id);
1333: }
1.117 markus 1334: key_free(id->key);
1335: id->key = NULL;
1.51 markus 1336: }
1337: }
1.117 markus 1338: if (sent)
1339: return (sent);
1.28 markus 1340: }
1.117 markus 1341: return (0);
1.20 markus 1342: }
1343:
1.23 markus 1344: /*
1345: * Send userauth request message specifying keyboard-interactive method.
1346: */
1347: int
1348: userauth_kbdint(Authctxt *authctxt)
1349: {
1350: static int attempt = 0;
1351:
1352: if (attempt++ >= options.number_of_password_prompts)
1353: return 0;
1.82 markus 1354: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1355: if (attempt > 1 && !authctxt->info_req_seen) {
1356: debug3("userauth_kbdint: disable: no info_req_seen");
1357: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1358: return 0;
1359: }
1.23 markus 1360:
1361: debug2("userauth_kbdint");
1362: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1363: packet_put_cstring(authctxt->server_user);
1364: packet_put_cstring(authctxt->service);
1365: packet_put_cstring(authctxt->method->name);
1366: packet_put_cstring(""); /* lang */
1367: packet_put_cstring(options.kbd_interactive_devices ?
1368: options.kbd_interactive_devices : "");
1369: packet_send();
1370:
1371: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1372: return 1;
1373: }
1374:
1375: /*
1.46 markus 1376: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1377: */
1378: void
1.92 markus 1379: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1380: {
1381: Authctxt *authctxt = ctxt;
1.46 markus 1382: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1383: u_int num_prompts, i;
1.23 markus 1384: int echo = 0;
1385:
1386: debug2("input_userauth_info_req");
1387:
1388: if (authctxt == NULL)
1389: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1390:
1391: authctxt->info_req_seen = 1;
1.23 markus 1392:
1393: name = packet_get_string(NULL);
1394: inst = packet_get_string(NULL);
1395: lang = packet_get_string(NULL);
1396: if (strlen(name) > 0)
1.116 itojun 1397: logit("%s", name);
1.23 markus 1398: if (strlen(inst) > 0)
1.116 itojun 1399: logit("%s", inst);
1.197 djm 1400: free(name);
1401: free(inst);
1402: free(lang);
1.23 markus 1403:
1404: num_prompts = packet_get_int();
1405: /*
1406: * Begin to build info response packet based on prompts requested.
1407: * We commit to providing the correct number of responses, so if
1408: * further on we run into a problem that prevents this, we have to
1409: * be sure and clean this up and send a correct error response.
1410: */
1411: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1412: packet_put_int(num_prompts);
1413:
1.73 markus 1414: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1415: for (i = 0; i < num_prompts; i++) {
1416: prompt = packet_get_string(NULL);
1417: echo = packet_get_char();
1418:
1.77 markus 1419: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1420:
1.49 markus 1421: packet_put_cstring(response);
1.204 djm 1422: explicit_bzero(response, strlen(response));
1.197 djm 1423: free(response);
1424: free(prompt);
1.23 markus 1425: }
1.90 markus 1426: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1427:
1.85 markus 1428: packet_add_padding(64);
1.23 markus 1429: packet_send();
1.68 markus 1430: }
1431:
1.100 markus 1432: static int
1.105 deraadt 1433: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1434: u_char *data, u_int datalen)
1435: {
1436: Buffer b;
1.101 markus 1437: struct stat st;
1.100 markus 1438: pid_t pid;
1.103 markus 1439: int to[2], from[2], status, version = 2;
1.100 markus 1440:
1.109 markus 1441: debug2("ssh_keysign called");
1.100 markus 1442:
1.101 markus 1443: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.179 dtucker 1444: error("ssh_keysign: not installed: %s", strerror(errno));
1.101 markus 1445: return -1;
1446: }
1.100 markus 1447: if (fflush(stdout) != 0)
1448: error("ssh_keysign: fflush: %s", strerror(errno));
1449: if (pipe(to) < 0) {
1450: error("ssh_keysign: pipe: %s", strerror(errno));
1451: return -1;
1452: }
1453: if (pipe(from) < 0) {
1454: error("ssh_keysign: pipe: %s", strerror(errno));
1455: return -1;
1456: }
1457: if ((pid = fork()) < 0) {
1458: error("ssh_keysign: fork: %s", strerror(errno));
1459: return -1;
1460: }
1461: if (pid == 0) {
1.174 dtucker 1462: /* keep the socket on exec */
1463: fcntl(packet_get_connection_in(), F_SETFD, 0);
1.155 markus 1464: permanently_drop_suid(getuid());
1.100 markus 1465: close(from[0]);
1466: if (dup2(from[1], STDOUT_FILENO) < 0)
1467: fatal("ssh_keysign: dup2: %s", strerror(errno));
1468: close(to[1]);
1469: if (dup2(to[0], STDIN_FILENO) < 0)
1470: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1471: close(from[1]);
1472: close(to[0]);
1.102 markus 1473: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1474: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1475: strerror(errno));
1476: }
1477: close(from[1]);
1478: close(to[0]);
1479:
1480: buffer_init(&b);
1.103 markus 1481: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1482: buffer_put_string(&b, data, datalen);
1.131 djm 1483: if (ssh_msg_send(to[1], version, &b) == -1)
1484: fatal("ssh_keysign: couldn't send request");
1.100 markus 1485:
1.110 djm 1486: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1487: error("ssh_keysign: no reply");
1.134 markus 1488: buffer_free(&b);
1.100 markus 1489: return -1;
1490: }
1.101 markus 1491: close(from[0]);
1492: close(to[1]);
1493:
1.103 markus 1494: while (waitpid(pid, &status, 0) < 0)
1495: if (errno != EINTR)
1496: break;
1.101 markus 1497:
1.100 markus 1498: if (buffer_get_char(&b) != version) {
1.101 markus 1499: error("ssh_keysign: bad version");
1.134 markus 1500: buffer_free(&b);
1.100 markus 1501: return -1;
1502: }
1503: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1504: buffer_free(&b);
1.100 markus 1505:
1506: return 0;
1507: }
1508:
1.68 markus 1509: int
1510: userauth_hostbased(Authctxt *authctxt)
1511: {
1512: Key *private = NULL;
1.100 markus 1513: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1514: Buffer b;
1515: u_char *signature, *blob;
1.179 dtucker 1516: char *chost, *pkalg, *p;
1.72 markus 1517: const char *service;
1.68 markus 1518: u_int blen, slen;
1.176 dtucker 1519: int ok, i, found = 0;
1.213 djm 1520:
1521: /* XXX provide some way to allow user to specify key types attempted */
1.68 markus 1522:
1523: /* check for a useful key */
1.100 markus 1524: for (i = 0; i < sensitive->nkeys; i++) {
1525: private = sensitive->keys[i];
1.68 markus 1526: if (private && private->type != KEY_RSA1) {
1527: found = 1;
1528: /* we take and free the key */
1.100 markus 1529: sensitive->keys[i] = NULL;
1.68 markus 1530: break;
1531: }
1532: }
1533: if (!found) {
1.109 markus 1534: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1535: return 0;
1536: }
1.211 djm 1537:
1538: debug("%s: trying hostkey type %s", __func__, key_type(private));
1539:
1.68 markus 1540: if (key_to_blob(private, &blob, &blen) == 0) {
1541: key_free(private);
1542: return 0;
1543: }
1.211 djm 1544:
1.84 markus 1545: /* figure out a name for the client host */
1.179 dtucker 1546: p = get_local_name(packet_get_connection_in());
1.84 markus 1547: if (p == NULL) {
1548: error("userauth_hostbased: cannot get local ipaddr/name");
1549: key_free(private);
1.197 djm 1550: free(blob);
1.84 markus 1551: return 0;
1552: }
1.150 djm 1553: xasprintf(&chost, "%s.", p);
1.84 markus 1554: debug2("userauth_hostbased: chost %s", chost);
1.197 djm 1555: free(p);
1.84 markus 1556:
1.72 markus 1557: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1558: authctxt->service;
1.68 markus 1559: pkalg = xstrdup(key_ssh_name(private));
1560: buffer_init(&b);
1561: /* construct data */
1.72 markus 1562: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1563: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1564: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1565: buffer_put_cstring(&b, service);
1.68 markus 1566: buffer_put_cstring(&b, authctxt->method->name);
1567: buffer_put_cstring(&b, pkalg);
1568: buffer_put_string(&b, blob, blen);
1569: buffer_put_cstring(&b, chost);
1570: buffer_put_cstring(&b, authctxt->local_user);
1571: #ifdef DEBUG_PK
1572: buffer_dump(&b);
1573: #endif
1.100 markus 1574: if (sensitive->external_keysign)
1575: ok = ssh_keysign(private, &signature, &slen,
1576: buffer_ptr(&b), buffer_len(&b));
1577: else
1578: ok = key_sign(private, &signature, &slen,
1579: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1580: key_free(private);
1581: buffer_free(&b);
1582: if (ok != 0) {
1583: error("key_sign failed");
1.197 djm 1584: free(chost);
1585: free(pkalg);
1586: free(blob);
1.68 markus 1587: return 0;
1588: }
1589: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1590: packet_put_cstring(authctxt->server_user);
1591: packet_put_cstring(authctxt->service);
1592: packet_put_cstring(authctxt->method->name);
1593: packet_put_cstring(pkalg);
1594: packet_put_string(blob, blen);
1595: packet_put_cstring(chost);
1596: packet_put_cstring(authctxt->local_user);
1597: packet_put_string(signature, slen);
1.204 djm 1598: explicit_bzero(signature, slen);
1.197 djm 1599: free(signature);
1600: free(chost);
1601: free(pkalg);
1602: free(blob);
1.68 markus 1603:
1604: packet_send();
1605: return 1;
1.23 markus 1606: }
1.170 djm 1607:
1.20 markus 1608: /* find auth method */
1609:
1610: /*
1611: * given auth method name, if configurable options permit this method fill
1612: * in auth_ident field and return true, otherwise return false.
1613: */
1.76 itojun 1614: static int
1.20 markus 1615: authmethod_is_enabled(Authmethod *method)
1616: {
1617: if (method == NULL)
1618: return 0;
1619: /* return false if options indicate this method is disabled */
1620: if (method->enabled == NULL || *method->enabled == 0)
1621: return 0;
1622: /* return false if batch mode is enabled but method needs interactive mode */
1623: if (method->batch_flag != NULL && *method->batch_flag != 0)
1624: return 0;
1625: return 1;
1626: }
1627:
1.76 itojun 1628: static Authmethod *
1.20 markus 1629: authmethod_lookup(const char *name)
1.1 markus 1630: {
1.20 markus 1631: Authmethod *method = NULL;
1632: if (name != NULL)
1633: for (method = authmethods; method->name != NULL; method++)
1634: if (strcmp(name, method->name) == 0)
1635: return method;
1636: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1637: return NULL;
1638: }
1.1 markus 1639:
1.53 markus 1640: /* XXX internal state */
1641: static Authmethod *current = NULL;
1642: static char *supported = NULL;
1643: static char *preferred = NULL;
1.105 deraadt 1644:
1.20 markus 1645: /*
1646: * Given the authentication method list sent by the server, return the
1647: * next method we should try. If the server initially sends a nil list,
1.67 markus 1648: * use a built-in default list.
1.41 stevesk 1649: */
1.76 itojun 1650: static Authmethod *
1.20 markus 1651: authmethod_get(char *authlist)
1652: {
1.53 markus 1653: char *name = NULL;
1.97 markus 1654: u_int next;
1.41 stevesk 1655:
1.20 markus 1656: /* Use a suitable default if we're passed a nil list. */
1657: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1658: authlist = options.preferred_authentications;
1.20 markus 1659:
1.53 markus 1660: if (supported == NULL || strcmp(authlist, supported) != 0) {
1661: debug3("start over, passed a different list %s", authlist);
1.197 djm 1662: free(supported);
1.53 markus 1663: supported = xstrdup(authlist);
1664: preferred = options.preferred_authentications;
1665: debug3("preferred %s", preferred);
1666: current = NULL;
1667: } else if (current != NULL && authmethod_is_enabled(current))
1668: return current;
1.20 markus 1669:
1.53 markus 1670: for (;;) {
1671: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1672: debug("No more authentication methods to try.");
1.53 markus 1673: current = NULL;
1674: return NULL;
1675: }
1676: preferred += next;
1.23 markus 1677: debug3("authmethod_lookup %s", name);
1.53 markus 1678: debug3("remaining preferred: %s", preferred);
1679: if ((current = authmethod_lookup(name)) != NULL &&
1680: authmethod_is_enabled(current)) {
1.23 markus 1681: debug3("authmethod_is_enabled %s", name);
1.109 markus 1682: debug("Next authentication method: %s", name);
1.197 djm 1683: free(name);
1.53 markus 1684: return current;
1.23 markus 1685: }
1.198 dtucker 1686: free(name);
1.1 markus 1687: }
1.53 markus 1688: }
1.1 markus 1689:
1.79 stevesk 1690: static char *
1.53 markus 1691: authmethods_get(void)
1692: {
1693: Authmethod *method = NULL;
1.93 markus 1694: Buffer b;
1695: char *list;
1.27 provos 1696:
1.93 markus 1697: buffer_init(&b);
1.53 markus 1698: for (method = authmethods; method->name != NULL; method++) {
1699: if (authmethod_is_enabled(method)) {
1.93 markus 1700: if (buffer_len(&b) > 0)
1701: buffer_append(&b, ",", 1);
1702: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1703: }
1704: }
1.93 markus 1705: buffer_append(&b, "\0", 1);
1706: list = xstrdup(buffer_ptr(&b));
1707: buffer_free(&b);
1708: return list;
1.1 markus 1709: }
1.170 djm 1710:
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