Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.279
1.279 ! markus 1: /* $OpenBSD: sshconnect2.c,v 1.278 2018/07/09 21:03:30 markus 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"
1.278 markus 46: #include "sshbuf.h"
1.1 markus 47: #include "packet.h"
48: #include "compat.h"
1.37 markus 49: #include "cipher.h"
1.278 markus 50: #include "sshkey.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"
1.246 djm 68: #include "utf8.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:
1.76 itojun 89: static int
1.259 markus 90: verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
1.61 markus 91: {
1.75 markus 92: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 93: fatal("Host key verification failed.");
1.61 markus 94: return 0;
95: }
96:
1.186 djm 97: static char *
98: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
99: {
100: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
101: size_t maxlen;
102: struct hostkeys *hostkeys;
103: int ktype;
1.188 djm 104: u_int i;
1.186 djm 105:
106: /* Find all hostkeys for this hostname */
107: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
108: hostkeys = init_hostkeys();
1.188 djm 109: for (i = 0; i < options.num_user_hostfiles; i++)
110: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
111: for (i = 0; i < options.num_system_hostfiles; i++)
112: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 113:
114: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
115: maxlen = strlen(avail) + 1;
116: first = xmalloc(maxlen);
117: last = xmalloc(maxlen);
118: *first = *last = '\0';
119:
120: #define ALG_APPEND(to, from) \
121: do { \
122: if (*to != '\0') \
123: strlcat(to, ",", maxlen); \
124: strlcat(to, from, maxlen); \
125: } while (0)
126:
127: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 128: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 129: fatal("%s: unknown alg %s", __func__, alg);
130: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 131: sshkey_type_plain(ktype), NULL))
1.186 djm 132: ALG_APPEND(first, alg);
133: else
134: ALG_APPEND(last, alg);
135: }
136: #undef ALG_APPEND
1.216 djm 137: xasprintf(&ret, "%s%s%s", first,
138: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 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 };
1.275 djm 155: char *s, *all_key;
1.219 markus 156: struct kex *kex;
1.221 markus 157: int r;
1.61 markus 158:
159: xxx_host = host;
160: xxx_hostaddr = hostaddr;
1.22 provos 161:
1.231 markus 162: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
163: fatal("%s: kex_names_cat", __func__);
164: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
1.60 stevesk 165: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.226 djm 166: compat_cipher_proposal(options.ciphers);
1.60 stevesk 167: myproposal[PROPOSAL_ENC_ALGS_STOC] =
1.226 djm 168: compat_cipher_proposal(options.ciphers);
1.245 dtucker 169: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
170: myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ?
1.277 sf 171: "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib";
1.226 djm 172: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
173: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
174: if (options.hostkeyalgorithms != NULL) {
1.275 djm 175: all_key = sshkey_alg_list(0, 0, 1, ',');
176: if (kex_assemble_names(&options.hostkeyalgorithms,
177: KEX_DEFAULT_PK_ALG, all_key) != 0)
1.226 djm 178: fatal("%s: kex_assemble_namelist", __func__);
1.275 djm 179: free(all_key);
1.88 deraadt 180: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 181: compat_pkalg_proposal(options.hostkeyalgorithms);
1.226 djm 182: } else {
1.225 markus 183: /* Enforce default */
184: options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
1.186 djm 185: /* Prefer algorithms that we already have keys for */
186: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 187: compat_pkalg_proposal(
188: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 189: }
1.115 markus 190:
1.196 dtucker 191: if (options.rekey_limit || options.rekey_interval)
1.254 dtucker 192: packet_set_rekey_limits(options.rekey_limit,
193: options.rekey_interval);
1.22 provos 194:
1.65 markus 195: /* start key exchange */
1.221 markus 196: if ((r = kex_setup(active_state, myproposal)) != 0)
197: fatal("kex_setup: %s", ssh_err(r));
1.219 markus 198: kex = active_state->kex;
1.207 markus 199: #ifdef WITH_OPENSSL
1.111 markus 200: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 201: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.243 djm 202: kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
203: kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
204: kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client;
1.111 markus 205: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 206: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 207: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.207 markus 208: #endif
1.199 markus 209: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 210: kex->client_version_string=client_version_string;
211: kex->server_version_string=server_version_string;
1.75 markus 212: kex->verify_host_key=&verify_host_key_callback;
1.22 provos 213:
1.263 markus 214: ssh_dispatch_run_fatal(active_state, DISPATCH_BLOCK, &kex->done);
1.173 andreas 215:
1.231 markus 216: /* remove ext-info from the KEX proposals for rekeying */
217: myproposal[PROPOSAL_KEX_ALGS] =
218: compat_kex_proposal(options.kex_algorithms);
219: if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
220: fatal("kex_prop2buf: %s", ssh_err(r));
1.62 markus 221:
222: session_id2 = kex->session_id;
223: session_id2_len = kex->session_id_len;
1.22 provos 224:
225: #ifdef DEBUG_KEXDH
226: /* send 1st encrypted/maced/compressed message */
1.278 markus 227: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
228: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
229: (r = sshpkt_send(ssh)) != 0)
230: fatal("%s: %s", __func__, ssh_err(r));
231: ssh_packet_write_wait(ssh);
1.22 provos 232: #endif
1.1 markus 233: }
1.11 markus 234:
1.1 markus 235: /*
236: * Authenticate user
237: */
1.20 markus 238:
1.214 djm 239: typedef struct cauthctxt Authctxt;
240: typedef struct cauthmethod Authmethod;
1.117 markus 241: typedef struct identity Identity;
242: typedef struct idlist Idlist;
1.20 markus 243:
1.117 markus 244: struct identity {
245: TAILQ_ENTRY(identity) next;
1.214 djm 246: int agent_fd; /* >=0 if agent supports key */
247: struct sshkey *key; /* public/private key */
1.117 markus 248: char *filename; /* comment for agent-only keys */
249: int tried;
250: int isprivate; /* key points to the private key */
1.191 dtucker 251: int userprovided;
1.117 markus 252: };
253: TAILQ_HEAD(idlist, identity);
1.20 markus 254:
1.214 djm 255: struct cauthctxt {
1.20 markus 256: const char *server_user;
1.68 markus 257: const char *local_user;
1.20 markus 258: const char *host;
259: const char *service;
1.214 djm 260: struct cauthmethod *method;
1.183 djm 261: sig_atomic_t success;
1.51 markus 262: char *authlist;
1.214 djm 263: int attempt;
1.68 markus 264: /* pubkey */
1.214 djm 265: struct idlist keys;
266: int agent_fd;
1.68 markus 267: /* hostbased */
1.100 markus 268: Sensitive *sensitive;
1.223 djm 269: char *oktypes, *ktypes;
270: const char *active_ktype;
1.82 markus 271: /* kbd-interactive */
272: int info_req_seen;
1.121 markus 273: /* generic */
274: void *methoddata;
1.20 markus 275: };
1.214 djm 276:
277: struct cauthmethod {
1.20 markus 278: char *name; /* string to compare against server's list */
279: int (*userauth)(Authctxt *authctxt);
1.170 djm 280: void (*cleanup)(Authctxt *authctxt);
1.20 markus 281: int *enabled; /* flag in option struct that enables method */
282: int *batch_flag; /* flag in option struct that disables method */
283: };
284:
1.261 markus 285: int input_userauth_service_accept(int, u_int32_t, struct ssh *);
286: int input_userauth_ext_info(int, u_int32_t, struct ssh *);
287: int input_userauth_success(int, u_int32_t, struct ssh *);
288: int input_userauth_success_unexpected(int, u_int32_t, struct ssh *);
289: int input_userauth_failure(int, u_int32_t, struct ssh *);
290: int input_userauth_banner(int, u_int32_t, struct ssh *);
291: int input_userauth_error(int, u_int32_t, struct ssh *);
292: int input_userauth_info_req(int, u_int32_t, struct ssh *);
293: int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
294: int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
1.86 itojun 295:
296: int userauth_none(Authctxt *);
297: int userauth_pubkey(Authctxt *);
298: int userauth_passwd(Authctxt *);
299: int userauth_kbdint(Authctxt *);
300: int userauth_hostbased(Authctxt *);
1.20 markus 301:
1.121 markus 302: #ifdef GSSAPI
303: int userauth_gssapi(Authctxt *authctxt);
1.261 markus 304: int input_gssapi_response(int type, u_int32_t, struct ssh *);
305: int input_gssapi_token(int type, u_int32_t, struct ssh *);
306: int input_gssapi_hash(int type, u_int32_t, struct ssh *);
307: int input_gssapi_error(int, u_int32_t, struct ssh *);
308: int input_gssapi_errtok(int, u_int32_t, struct ssh *);
1.121 markus 309: #endif
310:
1.86 itojun 311: void userauth(Authctxt *, char *);
1.51 markus 312:
1.272 djm 313: static int sign_and_send_pubkey(struct ssh *ssh, Authctxt *, Identity *);
1.117 markus 314: static void pubkey_prepare(Authctxt *);
315: static void pubkey_cleanup(Authctxt *);
1.251 djm 316: static void pubkey_reset(Authctxt *);
1.259 markus 317: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 318:
319: static Authmethod *authmethod_get(char *authlist);
320: static Authmethod *authmethod_lookup(const char *name);
321: static char *authmethods_get(void);
1.20 markus 322:
323: Authmethod authmethods[] = {
1.121 markus 324: #ifdef GSSAPI
1.132 markus 325: {"gssapi-with-mic",
1.121 markus 326: userauth_gssapi,
1.170 djm 327: NULL,
1.121 markus 328: &options.gss_authentication,
329: NULL},
330: #endif
1.81 markus 331: {"hostbased",
332: userauth_hostbased,
1.170 djm 333: NULL,
1.81 markus 334: &options.hostbased_authentication,
335: NULL},
1.20 markus 336: {"publickey",
337: userauth_pubkey,
1.170 djm 338: NULL,
1.28 markus 339: &options.pubkey_authentication,
1.20 markus 340: NULL},
1.81 markus 341: {"keyboard-interactive",
342: userauth_kbdint,
1.170 djm 343: NULL,
1.81 markus 344: &options.kbd_interactive_authentication,
345: &options.batch_mode},
1.20 markus 346: {"password",
347: userauth_passwd,
1.170 djm 348: NULL,
1.20 markus 349: &options.password_authentication,
1.23 markus 350: &options.batch_mode},
351: {"none",
352: userauth_none,
353: NULL,
1.170 djm 354: NULL,
1.23 markus 355: NULL},
1.170 djm 356: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 357: };
358:
359: void
1.68 markus 360: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 361: Sensitive *sensitive)
1.20 markus 362: {
1.231 markus 363: struct ssh *ssh = active_state;
1.20 markus 364: Authctxt authctxt;
1.231 markus 365: int r;
1.39 markus 366:
1.73 markus 367: if (options.challenge_response_authentication)
1.39 markus 368: options.kbd_interactive_authentication = 1;
1.53 markus 369: if (options.preferred_authentications == NULL)
370: options.preferred_authentications = authmethods_get();
371:
1.20 markus 372: /* setup authentication context */
1.82 markus 373: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 374: pubkey_prepare(&authctxt);
1.20 markus 375: authctxt.server_user = server_user;
1.68 markus 376: authctxt.local_user = local_user;
1.20 markus 377: authctxt.host = host;
378: authctxt.service = "ssh-connection"; /* service name */
379: authctxt.success = 0;
1.23 markus 380: authctxt.method = authmethod_lookup("none");
1.51 markus 381: authctxt.authlist = NULL;
1.121 markus 382: authctxt.methoddata = NULL;
1.100 markus 383: authctxt.sensitive = sensitive;
1.223 djm 384: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 385: authctxt.info_req_seen = 0;
1.215 djm 386: authctxt.agent_fd = -1;
1.23 markus 387: if (authctxt.method == NULL)
388: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 389:
1.231 markus 390: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
391: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
392: (r = sshpkt_send(ssh)) != 0)
393: fatal("%s: %s", __func__, ssh_err(r));
394:
1.260 markus 395: ssh->authctxt = &authctxt;
1.231 markus 396: ssh_dispatch_init(ssh, &input_userauth_error);
397: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
398: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.263 markus 399: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.260 markus 400: ssh->authctxt = NULL;
1.20 markus 401:
1.117 markus 402: pubkey_cleanup(&authctxt);
1.231 markus 403: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 404:
1.248 dtucker 405: if (!authctxt.success)
406: fatal("Authentication failed.");
1.109 markus 407: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 408: }
1.119 markus 409:
1.231 markus 410: /* ARGSUSED */
411: int
1.261 markus 412: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 413: {
1.260 markus 414: Authctxt *authctxt = ssh->authctxt;
1.231 markus 415: int r;
416:
417: if (ssh_packet_remaining(ssh) > 0) {
418: char *reply;
419:
420: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
421: goto out;
422: debug2("service_accept: %s", reply);
423: free(reply);
424: } else {
425: debug2("buggy server: service_accept w/o service");
426: }
427: if ((r = sshpkt_get_end(ssh)) != 0)
428: goto out;
429: debug("SSH2_MSG_SERVICE_ACCEPT received");
430:
431: /* initial userauth request */
432: userauth_none(authctxt);
433:
434: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
435: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
436: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
437: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
438: r = 0;
439: out:
440: return r;
441: }
442:
443: /* ARGSUSED */
444: int
1.261 markus 445: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 446: {
1.261 markus 447: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 448: }
449:
1.20 markus 450: void
1.51 markus 451: userauth(Authctxt *authctxt, char *authlist)
452: {
1.278 markus 453: struct ssh *ssh = active_state; /* XXX */
454:
1.170 djm 455: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
456: authctxt->method->cleanup(authctxt);
457:
1.197 djm 458: free(authctxt->methoddata);
459: authctxt->methoddata = NULL;
1.51 markus 460: if (authlist == NULL) {
461: authlist = authctxt->authlist;
462: } else {
1.197 djm 463: free(authctxt->authlist);
1.51 markus 464: authctxt->authlist = authlist;
465: }
466: for (;;) {
467: Authmethod *method = authmethod_get(authlist);
468: if (method == NULL)
1.264 dtucker 469: fatal("%s@%s: Permission denied (%s).",
470: authctxt->server_user, authctxt->host, authlist);
1.51 markus 471: authctxt->method = method;
1.119 markus 472:
473: /* reset the per method handler */
1.278 markus 474: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 475: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
476:
477: /* and try new method */
1.51 markus 478: if (method->userauth(authctxt) != 0) {
479: debug2("we sent a %s packet, wait for reply", method->name);
480: break;
481: } else {
482: debug2("we did not send a packet, disable method");
483: method->enabled = NULL;
484: }
485: }
486: }
1.105 deraadt 487:
1.169 djm 488: /* ARGSUSED */
1.218 markus 489: int
1.261 markus 490: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 491: {
1.35 markus 492: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 493: "type %d", type);
1.218 markus 494: return 0;
1.35 markus 495: }
1.105 deraadt 496:
1.169 djm 497: /* ARGSUSED */
1.218 markus 498: int
1.261 markus 499: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 500: {
1.246 djm 501: char *msg, *lang;
1.166 djm 502: u_int len;
1.126 deraadt 503:
1.246 djm 504: debug3("%s", __func__);
505: msg = packet_get_string(&len);
1.35 markus 506: lang = packet_get_string(NULL);
1.246 djm 507: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
508: fmprintf(stderr, "%s", msg);
509: free(msg);
1.197 djm 510: free(lang);
1.218 markus 511: return 0;
1.20 markus 512: }
1.105 deraadt 513:
1.169 djm 514: /* ARGSUSED */
1.218 markus 515: int
1.261 markus 516: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 517: {
1.260 markus 518: Authctxt *authctxt = ssh->authctxt;
1.172 djm 519:
1.20 markus 520: if (authctxt == NULL)
521: fatal("input_userauth_success: no authentication context");
1.197 djm 522: free(authctxt->authlist);
523: authctxt->authlist = NULL;
1.172 djm 524: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
525: authctxt->method->cleanup(authctxt);
1.197 djm 526: free(authctxt->methoddata);
527: authctxt->methoddata = NULL;
1.20 markus 528: authctxt->success = 1; /* break out */
1.218 markus 529: return 0;
1.20 markus 530: }
1.105 deraadt 531:
1.218 markus 532: int
1.261 markus 533: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 534: {
1.260 markus 535: Authctxt *authctxt = ssh->authctxt;
1.172 djm 536:
537: if (authctxt == NULL)
538: fatal("%s: no authentication context", __func__);
539:
540: fatal("Unexpected authentication success during %s.",
541: authctxt->method->name);
1.218 markus 542: return 0;
1.172 djm 543: }
544:
1.169 djm 545: /* ARGSUSED */
1.218 markus 546: int
1.261 markus 547: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 548: {
1.260 markus 549: Authctxt *authctxt = ssh->authctxt;
1.20 markus 550: char *authlist = NULL;
1.278 markus 551: u_char partial;
552: int r;
1.20 markus 553:
554: if (authctxt == NULL)
555: fatal("input_userauth_failure: no authentication context");
556:
1.278 markus 557: if ((r = sshpkt_get_cstring(ssh, &authlist, NULL)) != 0 ||
558: (r = sshpkt_get_u8(ssh, &partial)) != 0 ||
559: (r = sshpkt_get_end(ssh)) != 0)
560: goto out;
1.20 markus 561:
1.193 markus 562: if (partial != 0) {
1.247 dtucker 563: verbose("Authenticated with partial success.");
1.193 markus 564: /* reset state */
1.251 djm 565: pubkey_reset(authctxt);
1.193 markus 566: }
1.109 markus 567: debug("Authentications that can continue: %s", authlist);
1.20 markus 568:
1.51 markus 569: userauth(authctxt, authlist);
1.278 markus 570: authlist = NULL;
571: out:
572: free(authlist);
1.218 markus 573: return 0;
1.51 markus 574: }
1.169 djm 575:
576: /* ARGSUSED */
1.218 markus 577: int
1.261 markus 578: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 579: {
1.260 markus 580: Authctxt *authctxt = ssh->authctxt;
1.259 markus 581: struct sshkey *key = NULL;
1.117 markus 582: Identity *id = NULL;
1.96 markus 583: int pktype, sent = 0;
1.278 markus 584: size_t blen;
585: char *pkalg = NULL, *fp;
586: u_char *pkblob = NULL;
587: int r;
1.51 markus 588:
589: if (authctxt == NULL)
590: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 591:
1.278 markus 592: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
593: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
594: (r = sshpkt_get_end(ssh)) != 0)
595: goto done;
1.51 markus 596:
1.278 markus 597: debug("Server accepts key: pkalg %s blen %zu", pkalg, blen);
1.51 markus 598:
1.278 markus 599: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.117 markus 600: debug("unknown pkalg %s", pkalg);
601: goto done;
602: }
1.278 markus 603: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
604: debug("no key from blob. pkalg %s: %s", pkalg, ssh_err(r));
1.117 markus 605: goto done;
606: }
607: if (key->type != pktype) {
608: error("input_userauth_pk_ok: type mismatch "
609: "for decoded key (received %d, expected %d)",
610: key->type, pktype);
611: goto done;
612: }
1.222 djm 613: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
614: SSH_FP_DEFAULT)) == NULL)
615: goto done;
1.117 markus 616: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 617: free(fp);
1.117 markus 618:
1.127 markus 619: /*
620: * search keys in the reverse order, because last candidate has been
621: * moved to the end of the queue. this also avoids confusion by
622: * duplicate keys
623: */
1.136 henning 624: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 625: if (sshkey_equal(key, id->key)) {
1.272 djm 626: sent = sign_and_send_pubkey(ssh, authctxt, id);
1.51 markus 627: break;
628: }
1.117 markus 629: }
1.278 markus 630: r = 0;
631: done:
632: sshkey_free(key);
1.197 djm 633: free(pkalg);
634: free(pkblob);
1.51 markus 635:
1.106 deraadt 636: /* try another method if we did not send a packet */
1.278 markus 637: if (r == 0 && sent == 0)
1.51 markus 638: userauth(authctxt, NULL);
1.278 markus 639: return r;
1.20 markus 640: }
1.121 markus 641:
642: #ifdef GSSAPI
1.133 djm 643: int
1.121 markus 644: userauth_gssapi(Authctxt *authctxt)
645: {
1.278 markus 646: struct ssh *ssh = active_state; /* XXX */
1.121 markus 647: Gssctxt *gssctxt = NULL;
1.128 avsm 648: static gss_OID_set gss_supported = NULL;
1.139 djm 649: static u_int mech = 0;
1.121 markus 650: OM_uint32 min;
1.278 markus 651: int r, ok = 0;
1.121 markus 652:
653: /* Try one GSSAPI method at a time, rather than sending them all at
654: * once. */
655:
1.128 avsm 656: if (gss_supported == NULL)
657: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 658:
659: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 660: while (mech < gss_supported->count && !ok) {
1.121 markus 661: /* My DER encoding requires length<128 */
1.128 avsm 662: if (gss_supported->elements[mech].length < 128 &&
1.271 djm 663: ssh_gssapi_check_mechanism(&gssctxt,
1.161 djm 664: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 665: ok = 1; /* Mechanism works */
666: } else {
667: mech++;
668: }
669: }
670:
1.161 djm 671: if (!ok)
1.139 djm 672: return 0;
1.121 markus 673:
674: authctxt->methoddata=(void *)gssctxt;
675:
1.278 markus 676: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
677: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
678: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
679: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
680: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
681: (r = sshpkt_put_u32(ssh,
682: (gss_supported->elements[mech].length) + 2)) != 0 ||
683: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
684: (r = sshpkt_put_u8(ssh,
685: gss_supported->elements[mech].length)) != 0 ||
686: (r = sshpkt_put(ssh,
687: gss_supported->elements[mech].elements,
688: gss_supported->elements[mech].length)) != 0 ||
689: (r = sshpkt_send(ssh)) != 0)
690: fatal("%s: %s", __func__, ssh_err(r));
691:
692: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
693: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
694: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
695: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 696:
697: mech++; /* Move along to next candidate */
698:
699: return 1;
700: }
701:
1.130 markus 702: static OM_uint32
1.262 djm 703: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 704: {
1.260 markus 705: Authctxt *authctxt = ssh->authctxt;
1.130 markus 706: Gssctxt *gssctxt = authctxt->methoddata;
707: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 708: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
709: gss_buffer_desc gssbuf;
1.132 markus 710: OM_uint32 status, ms, flags;
1.278 markus 711: int r;
1.133 djm 712:
1.130 markus 713: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 714: recv_tok, &send_tok, &flags);
1.130 markus 715:
716: if (send_tok.length > 0) {
1.278 markus 717: u_char type = GSS_ERROR(status) ?
718: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
719: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
720:
721: if ((r = sshpkt_start(ssh, type)) != 0 ||
722: (r = sshpkt_put_string(ssh, send_tok.value,
723: send_tok.length)) != 0 ||
724: (r = sshpkt_send(ssh)) != 0)
725: fatal("%s: %s", __func__, ssh_err(r));
1.133 djm 726:
1.130 markus 727: gss_release_buffer(&ms, &send_tok);
728: }
1.133 djm 729:
1.130 markus 730: if (status == GSS_S_COMPLETE) {
1.132 markus 731: /* send either complete or MIC, depending on mechanism */
732: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 733: if ((r = sshpkt_start(ssh,
734: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
735: (r = sshpkt_send(ssh)) != 0)
736: fatal("%s: %s", __func__, ssh_err(r));
1.132 markus 737: } else {
1.278 markus 738: struct sshbuf *b;
739:
740: if ((b = sshbuf_new()) == NULL)
741: fatal("%s: sshbuf_new failed", __func__);
742: ssh_gssapi_buildmic(b, authctxt->server_user,
1.132 markus 743: authctxt->service, "gssapi-with-mic");
744:
1.278 markus 745: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
746: fatal("%s: sshbuf_mutable_ptr failed", __func__);
747: gssbuf.length = sshbuf_len(b);
1.133 djm 748:
1.132 markus 749: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 750:
1.132 markus 751: if (!GSS_ERROR(status)) {
1.278 markus 752: if ((r = sshpkt_start(ssh,
753: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
754: (r = sshpkt_put_string(ssh, mic.value,
755: mic.length)) != 0 ||
756: (r = sshpkt_send(ssh)) != 0)
757: fatal("%s: %s", __func__, ssh_err(r));
1.132 markus 758: }
1.133 djm 759:
1.278 markus 760: sshbuf_free(b);
1.132 markus 761: gss_release_buffer(&ms, &mic);
1.133 djm 762: }
1.130 markus 763: }
1.133 djm 764:
1.130 markus 765: return status;
766: }
767:
1.169 djm 768: /* ARGSUSED */
1.220 djm 769: int
1.261 markus 770: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 771: {
1.260 markus 772: Authctxt *authctxt = ssh->authctxt;
1.121 markus 773: Gssctxt *gssctxt;
1.278 markus 774: size_t oidlen;
775: u_char *oidv = NULL;
776: int r;
1.121 markus 777:
778: if (authctxt == NULL)
779: fatal("input_gssapi_response: no authentication context");
780: gssctxt = authctxt->methoddata;
781:
782: /* Setup our OID */
1.278 markus 783: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
784: goto done;
1.121 markus 785:
1.129 markus 786: if (oidlen <= 2 ||
787: oidv[0] != SSH_GSS_OIDTYPE ||
788: oidv[1] != oidlen - 2) {
789: debug("Badly encoded mechanism OID received");
790: userauth(authctxt, NULL);
1.278 markus 791: goto ok;
1.121 markus 792: }
1.129 markus 793:
794: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
795: fatal("Server returned different OID than expected");
1.121 markus 796:
1.278 markus 797: if ((r = sshpkt_get_end(ssh)) != 0)
798: goto done;
1.121 markus 799:
1.262 djm 800: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 801: /* Start again with next method on list */
802: debug("Trying to start again");
803: userauth(authctxt, NULL);
1.278 markus 804: goto ok;
1.121 markus 805: }
1.278 markus 806: ok:
807: r = 0;
808: done:
809: free(oidv);
810: return r;
1.121 markus 811: }
812:
1.169 djm 813: /* ARGSUSED */
1.220 djm 814: int
1.261 markus 815: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 816: {
1.260 markus 817: Authctxt *authctxt = ssh->authctxt;
1.121 markus 818: gss_buffer_desc recv_tok;
1.278 markus 819: u_char *p = NULL;
820: size_t len;
1.130 markus 821: OM_uint32 status;
1.278 markus 822: int r;
1.121 markus 823:
824: if (authctxt == NULL)
825: fatal("input_gssapi_response: no authentication context");
826:
1.278 markus 827: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
828: (r = sshpkt_get_end(ssh)) != 0)
829: goto out;
1.121 markus 830:
1.278 markus 831: recv_tok.value = p;
832: recv_tok.length = len;
1.262 djm 833: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 834:
1.278 markus 835: /* Start again with the next method in the list */
1.121 markus 836: if (GSS_ERROR(status)) {
837: userauth(authctxt, NULL);
1.278 markus 838: /* ok */
1.121 markus 839: }
1.278 markus 840: r = 0;
841: out:
842: free(p);
843: return r;
1.121 markus 844: }
845:
1.169 djm 846: /* ARGSUSED */
1.220 djm 847: int
1.261 markus 848: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 849: {
1.260 markus 850: Authctxt *authctxt = ssh->authctxt;
1.121 markus 851: Gssctxt *gssctxt;
852: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
853: gss_buffer_desc recv_tok;
1.194 djm 854: OM_uint32 ms;
1.278 markus 855: u_char *p = NULL;
856: size_t len;
857: int r;
1.121 markus 858:
859: if (authctxt == NULL)
860: fatal("input_gssapi_response: no authentication context");
861: gssctxt = authctxt->methoddata;
862:
1.278 markus 863: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
864: (r = sshpkt_get_end(ssh)) != 0) {
865: free(p);
866: return r;
867: }
1.121 markus 868:
869: /* Stick it into GSSAPI and see what it says */
1.278 markus 870: recv_tok.value = p;
871: recv_tok.length = len;
1.194 djm 872: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 873: &recv_tok, &send_tok, NULL);
1.278 markus 874: free(p);
1.121 markus 875: gss_release_buffer(&ms, &send_tok);
876:
877: /* Server will be returning a failed packet after this one */
1.220 djm 878: return 0;
1.121 markus 879: }
880:
1.169 djm 881: /* ARGSUSED */
1.220 djm 882: int
1.261 markus 883: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 884: {
1.278 markus 885: char *msg = NULL;
886: char *lang = NULL;
887: int r;
1.121 markus 888:
1.278 markus 889: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
890: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
891: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
892: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
893: goto out;
894: r = sshpkt_get_end(ssh);
1.143 stevesk 895: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 896: out:
1.197 djm 897: free(msg);
898: free(lang);
1.278 markus 899: return r;
1.121 markus 900: }
901: #endif /* GSSAPI */
1.20 markus 902:
1.1 markus 903: int
1.23 markus 904: userauth_none(Authctxt *authctxt)
905: {
1.278 markus 906: struct ssh *ssh = active_state; /* XXX */
907: int r;
908:
1.23 markus 909: /* initial userauth request */
1.278 markus 910: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
911: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
912: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
913: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
914: (r = sshpkt_send(ssh)) != 0)
915: fatal("%s: %s", __func__, ssh_err(r));
1.23 markus 916: return 1;
917: }
918:
919: int
1.20 markus 920: userauth_passwd(Authctxt *authctxt)
1.1 markus 921: {
1.278 markus 922: struct ssh *ssh = active_state; /* XXX */
1.6 markus 923: static int attempt = 0;
1.266 dtucker 924: char prompt[256];
1.1 markus 925: char *password;
1.175 dtucker 926: const char *host = options.host_key_alias ? options.host_key_alias :
927: authctxt->host;
1.278 markus 928: int r;
1.6 markus 929:
1.13 todd 930: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 931: return 0;
1.13 todd 932:
1.87 deraadt 933: if (attempt != 1)
1.13 todd 934: error("Permission denied, please try again.");
1.1 markus 935:
1.43 itojun 936: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 937: authctxt->server_user, host);
1.1 markus 938: password = read_passphrase(prompt, 0);
1.278 markus 939: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
940: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
941: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
942: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
943: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
944: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
945: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
946: (r = sshpkt_send(ssh)) != 0)
947: fatal("%s: %s", __func__, ssh_err(r));
1.99 markus 948:
1.278 markus 949: if (password)
950: freezero(password, strlen(password));
951:
952: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 953: &input_userauth_passwd_changereq);
954:
1.1 markus 955: return 1;
956: }
1.169 djm 957:
1.99 markus 958: /*
959: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
960: */
1.169 djm 961: /* ARGSUSED */
1.218 markus 962: int
1.261 markus 963: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 964: {
1.260 markus 965: Authctxt *authctxt = ssh->authctxt;
1.278 markus 966: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 967: char prompt[256];
1.252 djm 968: const char *host;
1.278 markus 969: int r;
1.99 markus 970:
971: debug2("input_userauth_passwd_changereq");
972:
973: if (authctxt == NULL)
974: fatal("input_userauth_passwd_changereq: "
975: "no authentication context");
1.252 djm 976: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 977:
1.278 markus 978: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
979: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
980: goto out;
1.99 markus 981: if (strlen(info) > 0)
1.116 itojun 982: logit("%s", info);
1.278 markus 983: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
984: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
985: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
986: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
987: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
988: goto out;
989:
1.104 deraadt 990: snprintf(prompt, sizeof(prompt),
1.99 markus 991: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 992: authctxt->server_user, host);
1.99 markus 993: password = read_passphrase(prompt, 0);
1.278 markus 994: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
995: goto out;
996:
997: freezero(password, strlen(password));
1.99 markus 998: password = NULL;
999: while (password == NULL) {
1.104 deraadt 1000: snprintf(prompt, sizeof(prompt),
1.99 markus 1001: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1002: authctxt->server_user, host);
1.99 markus 1003: password = read_passphrase(prompt, RP_ALLOW_EOF);
1004: if (password == NULL) {
1005: /* bail out */
1.278 markus 1006: r = 0;
1007: goto out;
1.99 markus 1008: }
1.104 deraadt 1009: snprintf(prompt, sizeof(prompt),
1.99 markus 1010: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1011: authctxt->server_user, host);
1.99 markus 1012: retype = read_passphrase(prompt, 0);
1013: if (strcmp(password, retype) != 0) {
1.278 markus 1014: freezero(password, strlen(password));
1.116 itojun 1015: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1016: password = NULL;
1017: }
1.278 markus 1018: freezero(retype, strlen(retype));
1.99 markus 1019: }
1.278 markus 1020: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1021: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1022: (r = sshpkt_send(ssh)) != 0)
1023: goto out;
1.104 deraadt 1024:
1.278 markus 1025: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1026: &input_userauth_passwd_changereq);
1.278 markus 1027: r = 0;
1028: out:
1029: if (password)
1030: freezero(password, strlen(password));
1031: free(info);
1032: free(lang);
1033: return r;
1.117 markus 1034: }
1035:
1.272 djm 1036: /*
1037: * Select an algorithm for publickey signatures.
1038: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1039: *
1040: * Call with ssh==NULL to ignore server-sig-algs extension list and
1041: * only attempt with the key's base signature type.
1042: */
1043: static char *
1044: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1045: {
1.274 djm 1046: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.231 markus 1047:
1.272 djm 1048: /*
1049: * The signature algorithm will only differ from the key algorithm
1050: * for RSA keys/certs and when the server advertises support for
1051: * newer (SHA2) algorithms.
1052: */
1053: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1054: (key->type != KEY_RSA && key->type != KEY_RSA_CERT)) {
1055: /* Filter base key signature alg against our configuration */
1.279 ! markus 1056: return match_list(sshkey_ssh_name(key),
1.272 djm 1057: options.pubkey_key_types, NULL);
1.231 markus 1058: }
1059:
1.272 djm 1060: /*
1061: * For RSA keys/certs, since these might have a different sig type:
1062: * find the first entry in PubkeyAcceptedKeyTypes of the right type
1063: * that also appears in the supported signature algorithms list from
1064: * the server.
1065: */
1066: oallowed = allowed = xstrdup(options.pubkey_key_types);
1067: while ((cp = strsep(&allowed, ",")) != NULL) {
1068: if (sshkey_type_from_name(cp) != key->type)
1069: continue;
1.274 djm 1070: tmp = match_list(sshkey_sigalg_by_name(cp), ssh->kex->server_sig_algs, NULL);
1071: if (tmp != NULL)
1072: alg = xstrdup(cp);
1073: free(tmp);
1.272 djm 1074: if (alg != NULL)
1075: break;
1.269 djm 1076: }
1.272 djm 1077: free(oallowed);
1078: return alg;
1.269 djm 1079: }
1080:
1.117 markus 1081: static int
1.214 djm 1082: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1083: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1084: {
1.259 markus 1085: struct sshkey *prv;
1.269 djm 1086: int r;
1.99 markus 1087:
1.272 djm 1088: /* The agent supports this key. */
1.269 djm 1089: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1090: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1091: data, datalen, alg, compat);
1.269 djm 1092: }
1.214 djm 1093:
1.117 markus 1094: /*
1.272 djm 1095: * We have already loaded the private key or the private key is
1096: * stored in external hardware.
1.117 markus 1097: */
1.255 djm 1098: if (id->key != NULL &&
1.272 djm 1099: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1100: if ((r = sshkey_sign(id->key, sigp, lenp, data, datalen,
1101: alg, compat)) != 0)
1102: return r;
1103: /*
1104: * PKCS#11 tokens may not support all signature algorithms,
1105: * so check what we get back.
1106: */
1107: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0)
1108: return r;
1109: return 0;
1110: }
1.255 djm 1111:
1.272 djm 1112: /* Load the private key from the file. */
1.229 jcs 1113: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1114: return SSH_ERR_KEY_NOT_FOUND;
1.265 djm 1115: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1116: error("%s: private key %s contents do not match public",
1117: __func__, id->filename);
1118: return SSH_ERR_KEY_NOT_FOUND;
1119: }
1.272 djm 1120: r = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat);
1.214 djm 1121: sshkey_free(prv);
1.269 djm 1122: return r;
1.51 markus 1123: }
1124:
1.76 itojun 1125: static int
1.255 djm 1126: id_filename_matches(Identity *id, Identity *private_id)
1127: {
1128: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1129: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1130: size_t i, slen;
1131:
1132: if (strcmp(id->filename, private_id->filename) == 0)
1133: return 1;
1134: for (i = 0; suffixes[i]; i++) {
1135: slen = strlen(suffixes[i]);
1136: if (len > slen && plen == len - slen &&
1137: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1138: memcmp(id->filename, private_id->filename, plen) == 0)
1139: return 1;
1140: }
1141: return 0;
1142: }
1143:
1144: static int
1.272 djm 1145: sign_and_send_pubkey(struct ssh *ssh, Authctxt *authctxt, Identity *id)
1.1 markus 1146: {
1.272 djm 1147: struct sshbuf *b = NULL;
1148: Identity *private_id, *sign_id = NULL;
1149: u_char *signature = NULL;
1150: size_t slen = 0, skip = 0;
1151: int r, fallback_sigtype, sent = 0;
1152: char *alg = NULL, *fp = NULL;
1153: const char *loc = "";
1.1 markus 1154:
1.222 djm 1155: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1156: SSH_FP_DEFAULT)) == NULL)
1157: return 0;
1.51 markus 1158:
1.272 djm 1159: debug3("%s: %s %s", __func__, sshkey_type(id->key), fp);
1.1 markus 1160:
1.227 djm 1161: /*
1162: * If the key is an certificate, try to find a matching private key
1163: * and use it to complete the signature.
1.241 djm 1164: * If no such private key exists, fall back to trying the certificate
1165: * key itself in case it has a private half already loaded.
1.272 djm 1166: * This will try to set sign_id to the private key that will perform
1167: * the signature.
1.227 djm 1168: */
1.272 djm 1169: if (sshkey_is_cert(id->key)) {
1.227 djm 1170: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1171: if (sshkey_equal_public(id->key, private_id->key) &&
1172: id->key->type != private_id->key->type) {
1.272 djm 1173: sign_id = private_id;
1.227 djm 1174: break;
1175: }
1176: }
1.255 djm 1177: /*
1178: * Exact key matches are preferred, but also allow
1179: * filename matches for non-PKCS#11/agent keys that
1180: * didn't load public keys. This supports the case
1181: * of keeping just a private key file and public
1182: * certificate on disk.
1183: */
1.272 djm 1184: if (sign_id == NULL &&
1185: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1186: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1187: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1188: if (private_id->key == NULL &&
1189: id_filename_matches(id, private_id)) {
1.272 djm 1190: sign_id = private_id;
1.255 djm 1191: break;
1192: }
1193: }
1194: }
1.272 djm 1195: if (sign_id != NULL) {
1.227 djm 1196: debug2("%s: using private key \"%s\"%s for "
1197: "certificate", __func__, id->filename,
1198: id->agent_fd != -1 ? " from agent" : "");
1199: } else {
1.240 djm 1200: debug("%s: no separate private key for certificate "
1.227 djm 1201: "\"%s\"", __func__, id->filename);
1202: }
1203: }
1204:
1.272 djm 1205: /*
1206: * If the above didn't select another identity to do the signing
1207: * then default to the one we started with.
1208: */
1209: if (sign_id == NULL)
1210: sign_id = id;
1211:
1212: /* assemble and sign data */
1213: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1214: free(alg);
1215: slen = 0;
1216: signature = NULL;
1217: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1218: id->key)) == NULL) {
1219: error("%s: no mutual signature supported", __func__);
1220: goto out;
1221: }
1222: debug3("%s: signing using %s", __func__, alg);
1223:
1224: sshbuf_free(b);
1225: if ((b = sshbuf_new()) == NULL)
1226: fatal("%s: sshbuf_new failed", __func__);
1227: if (datafellows & SSH_OLD_SESSIONID) {
1228: if ((r = sshbuf_put(b, session_id2,
1229: session_id2_len)) != 0) {
1230: fatal("%s: sshbuf_put: %s",
1231: __func__, ssh_err(r));
1232: }
1233: } else {
1234: if ((r = sshbuf_put_string(b, session_id2,
1235: session_id2_len)) != 0) {
1236: fatal("%s: sshbuf_put_string: %s",
1237: __func__, ssh_err(r));
1238: }
1239: }
1.278 markus 1240: skip = sshbuf_len(b);
1.272 djm 1241: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1242: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1243: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1244: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1245: (r = sshbuf_put_u8(b, 1)) != 0 ||
1246: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1247: (r = sshkey_puts(id->key, b)) != 0) {
1248: fatal("%s: assemble signed data: %s",
1249: __func__, ssh_err(r));
1250: }
1251:
1252: /* generate signature */
1253: r = identity_sign(sign_id, &signature, &slen,
1254: sshbuf_ptr(b), sshbuf_len(b), datafellows, alg);
1255: if (r == 0)
1256: break;
1257: else if (r == SSH_ERR_KEY_NOT_FOUND)
1258: goto out; /* soft failure */
1259: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1260: !fallback_sigtype) {
1261: if (sign_id->agent_fd != -1)
1262: loc = "agent ";
1263: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1264: loc = "token ";
1265: logit("%skey %s %s returned incorrect signature type",
1266: loc, sshkey_type(id->key), fp);
1267: continue;
1268: }
1269: error("%s: signing failed: %s", __func__, ssh_err(r));
1270: goto out;
1.17 markus 1271: }
1.272 djm 1272: if (slen == 0 || signature == NULL) /* shouldn't happen */
1273: fatal("%s: no signature", __func__);
1.51 markus 1274:
1.1 markus 1275: /* append signature */
1.272 djm 1276: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1277: fatal("%s: append signature: %s", __func__, ssh_err(r));
1.1 markus 1278:
1.272 djm 1279: #ifdef DEBUG_PK
1280: sshbuf_dump(b, stderr);
1281: #endif
1.1 markus 1282: /* skip session id and packet type */
1.272 djm 1283: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1284: fatal("%s: consume: %s", __func__, ssh_err(r));
1.1 markus 1285:
1286: /* put remaining data from buffer into packet */
1.272 djm 1287: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1288: (r = sshpkt_putb(ssh, b)) != 0 ||
1289: (r = sshpkt_send(ssh)) != 0)
1290: fatal("%s: enqueue request: %s", __func__, ssh_err(r));
1291:
1292: /* success */
1293: sent = 1;
1.17 markus 1294:
1.272 djm 1295: out:
1296: free(fp);
1297: free(alg);
1298: sshbuf_free(b);
1299: freezero(signature, slen);
1300: return sent;
1.16 markus 1301: }
1302:
1.76 itojun 1303: static int
1.272 djm 1304: send_pubkey_test(struct ssh *ssh, Authctxt *authctxt, Identity *id)
1.20 markus 1305: {
1.272 djm 1306: u_char *blob = NULL;
1307: char *alg = NULL;
1.278 markus 1308: size_t bloblen;
1309: u_int have_sig = 0;
1310: int sent = 0, r;
1.20 markus 1311:
1.272 djm 1312: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1313: debug("%s: no mutual signature algorithm", __func__);
1314: goto out;
1315: }
1.16 markus 1316:
1.278 markus 1317: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1318: /* we cannot handle this key */
1.272 djm 1319: debug3("%s: cannot handle key", __func__);
1320: goto out;
1.16 markus 1321: }
1.51 markus 1322: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1323: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1324:
1.278 markus 1325: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1326: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1327: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1328: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1329: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1330: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1331: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1332: (r = sshpkt_send(ssh)) != 0)
1333: fatal("%s: %s", __func__, ssh_err(r));
1.272 djm 1334: sent = 1;
1.278 markus 1335:
1336: out:
1.272 djm 1337: free(alg);
1.197 djm 1338: free(blob);
1.272 djm 1339: return sent;
1.51 markus 1340: }
1341:
1.259 markus 1342: static struct sshkey *
1.229 jcs 1343: load_identity_file(Identity *id)
1.51 markus 1344: {
1.259 markus 1345: struct sshkey *private = NULL;
1.229 jcs 1346: char prompt[300], *passphrase, *comment;
1.215 djm 1347: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1348: struct stat st;
1.16 markus 1349:
1.229 jcs 1350: if (stat(id->filename, &st) < 0) {
1351: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1352: id->filename, strerror(errno));
1.52 markus 1353: return NULL;
1354: }
1.214 djm 1355: snprintf(prompt, sizeof prompt,
1.229 jcs 1356: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1357: for (i = 0; i <= options.number_of_password_prompts; i++) {
1358: if (i == 0)
1359: passphrase = "";
1360: else {
1.20 markus 1361: passphrase = read_passphrase(prompt, 0);
1.214 djm 1362: if (*passphrase == '\0') {
1.20 markus 1363: debug2("no passphrase given, try next key");
1.214 djm 1364: free(passphrase);
1365: break;
1366: }
1367: }
1.229 jcs 1368: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1369: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1370: case 0:
1371: break;
1372: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1373: if (options.batch_mode) {
1374: quit = 1;
1375: break;
1376: }
1.215 djm 1377: if (i != 0)
1378: debug2("bad passphrase given, try again...");
1.214 djm 1379: break;
1380: case SSH_ERR_SYSTEM_ERROR:
1381: if (errno == ENOENT) {
1382: debug2("Load key \"%s\": %s",
1.229 jcs 1383: id->filename, ssh_err(r));
1.51 markus 1384: quit = 1;
1.214 djm 1385: break;
1.20 markus 1386: }
1.214 djm 1387: /* FALLTHROUGH */
1388: default:
1.229 jcs 1389: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1390: quit = 1;
1391: break;
1392: }
1.230 djm 1393: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1394: !(id->key && id->isprivate))
1395: maybe_add_key_to_agent(id->filename, private, comment,
1396: passphrase);
1.278 markus 1397: if (i > 0)
1398: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1399: free(comment);
1.214 djm 1400: if (private != NULL || quit)
1401: break;
1.16 markus 1402: }
1.51 markus 1403: return private;
1404: }
1405:
1.272 djm 1406: static int
1407: key_type_allowed_by_config(struct sshkey *key)
1408: {
1409: if (match_pattern_list(sshkey_ssh_name(key),
1410: options.pubkey_key_types, 0) == 1)
1411: return 1;
1412:
1413: /* RSA keys/certs might be allowed by alternate signature types */
1414: switch (key->type) {
1415: case KEY_RSA:
1416: if (match_pattern_list("rsa-sha2-512",
1417: options.pubkey_key_types, 0) == 1)
1418: return 1;
1419: if (match_pattern_list("rsa-sha2-256",
1420: options.pubkey_key_types, 0) == 1)
1421: return 1;
1422: break;
1423: case KEY_RSA_CERT:
1424: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1425: options.pubkey_key_types, 0) == 1)
1426: return 1;
1427: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1428: options.pubkey_key_types, 0) == 1)
1429: return 1;
1430: break;
1431: }
1432: return 0;
1433: }
1434:
1435:
1.117 markus 1436: /*
1437: * try keys in the following order:
1.227 djm 1438: * 1. certificates listed in the config file
1439: * 2. other input certificates
1440: * 3. agent keys that are found in the config file
1441: * 4. other agent keys
1442: * 5. keys that are only listed in the config file
1.117 markus 1443: */
1444: static void
1445: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1446: {
1.214 djm 1447: struct identity *id, *id2, *tmp;
1448: struct idlist agent, files, *preferred;
1449: struct sshkey *key;
1.230 djm 1450: int agent_fd = -1, i, r, found;
1.214 djm 1451: size_t j;
1452: struct ssh_identitylist *idlist;
1.51 markus 1453:
1.117 markus 1454: TAILQ_INIT(&agent); /* keys from the agent */
1455: TAILQ_INIT(&files); /* keys from the config file */
1456: preferred = &authctxt->keys;
1457: TAILQ_INIT(preferred); /* preferred order of keys */
1458:
1.190 djm 1459: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1460: for (i = 0; i < options.num_identity_files; i++) {
1461: key = options.identity_keys[i];
1.180 djm 1462: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1463: continue;
1464: options.identity_keys[i] = NULL;
1.150 djm 1465: id = xcalloc(1, sizeof(*id));
1.230 djm 1466: id->agent_fd = -1;
1.117 markus 1467: id->key = key;
1468: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1469: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1470: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1471: }
1.227 djm 1472: /* list of certificates specified by user */
1473: for (i = 0; i < options.num_certificate_files; i++) {
1474: key = options.certificates[i];
1.278 markus 1475: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.227 djm 1476: key->cert->type != SSH2_CERT_TYPE_USER)
1477: continue;
1478: id = xcalloc(1, sizeof(*id));
1.230 djm 1479: id->agent_fd = -1;
1.227 djm 1480: id->key = key;
1481: id->filename = xstrdup(options.certificate_files[i]);
1482: id->userprovided = options.certificate_file_userprovided[i];
1483: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1484: }
1485: /* list of keys supported by the agent */
1.214 djm 1486: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1487: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1488: debug("%s: ssh_get_authentication_socket: %s",
1489: __func__, ssh_err(r));
1.258 naddy 1490: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1491: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1492: debug("%s: ssh_fetch_identitylist: %s",
1493: __func__, ssh_err(r));
1.237 markus 1494: close(agent_fd);
1.214 djm 1495: } else {
1496: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1497: found = 0;
1498: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1499: /*
1500: * agent keys from the config file are
1501: * preferred
1502: */
1503: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1504: TAILQ_REMOVE(&files, id, next);
1505: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1506: id->agent_fd = agent_fd;
1.117 markus 1507: found = 1;
1508: break;
1509: }
1510: }
1.135 markus 1511: if (!found && !options.identities_only) {
1.150 djm 1512: id = xcalloc(1, sizeof(*id));
1.214 djm 1513: /* XXX "steals" key/comment from idlist */
1514: id->key = idlist->keys[j];
1515: id->filename = idlist->comments[j];
1516: idlist->keys[j] = NULL;
1517: idlist->comments[j] = NULL;
1518: id->agent_fd = agent_fd;
1.117 markus 1519: TAILQ_INSERT_TAIL(&agent, id, next);
1520: }
1521: }
1.214 djm 1522: ssh_free_identitylist(idlist);
1.117 markus 1523: /* append remaining agent keys */
1524: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1525: TAILQ_REMOVE(&agent, id, next);
1526: TAILQ_INSERT_TAIL(preferred, id, next);
1527: }
1.214 djm 1528: authctxt->agent_fd = agent_fd;
1.244 djm 1529: }
1530: /* Prefer PKCS11 keys that are explicitly listed */
1531: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1532: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1533: continue;
1534: found = 0;
1535: TAILQ_FOREACH(id2, &files, next) {
1536: if (id2->key == NULL ||
1537: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1538: continue;
1539: if (sshkey_equal(id->key, id2->key)) {
1540: TAILQ_REMOVE(&files, id, next);
1541: TAILQ_INSERT_TAIL(preferred, id, next);
1542: found = 1;
1543: break;
1544: }
1545: }
1546: /* If IdentitiesOnly set and key not found then don't use it */
1547: if (!found && options.identities_only) {
1548: TAILQ_REMOVE(&files, id, next);
1.278 markus 1549: freezero(id, sizeof(*id));
1.244 djm 1550: }
1.117 markus 1551: }
1552: /* append remaining keys from the config file */
1553: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1554: TAILQ_REMOVE(&files, id, next);
1555: TAILQ_INSERT_TAIL(preferred, id, next);
1556: }
1.228 djm 1557: /* finally, filter by PubkeyAcceptedKeyTypes */
1558: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1559: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1560: debug("Skipping %s key %s - "
1561: "not in PubkeyAcceptedKeyTypes",
1562: sshkey_ssh_name(id->key), id->filename);
1563: TAILQ_REMOVE(preferred, id, next);
1564: sshkey_free(id->key);
1565: free(id->filename);
1566: memset(id, 0, sizeof(*id));
1567: continue;
1568: }
1.230 djm 1569: debug2("key: %s (%p)%s%s", id->filename, id->key,
1570: id->userprovided ? ", explicit" : "",
1571: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1572: }
1.17 markus 1573: }
1574:
1.117 markus 1575: static void
1576: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1577: {
1.117 markus 1578: Identity *id;
1.51 markus 1579:
1.214 djm 1580: if (authctxt->agent_fd != -1)
1581: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1582: for (id = TAILQ_FIRST(&authctxt->keys); id;
1583: id = TAILQ_FIRST(&authctxt->keys)) {
1584: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1585: sshkey_free(id->key);
1.197 djm 1586: free(id->filename);
1587: free(id);
1.117 markus 1588: }
1.1 markus 1589: }
1590:
1.251 djm 1591: static void
1592: pubkey_reset(Authctxt *authctxt)
1593: {
1594: Identity *id;
1595:
1596: TAILQ_FOREACH(id, &authctxt->keys, next)
1597: id->tried = 0;
1598: }
1599:
1.225 markus 1600: static int
1601: try_identity(Identity *id)
1602: {
1603: if (!id->key)
1604: return (0);
1.279 ! markus 1605: if (sshkey_type_plain(id->key->type) == KEY_RSA &&
1.225 markus 1606: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1607: debug("Skipped %s key %s for RSA/MD5 server",
1.279 ! markus 1608: sshkey_type(id->key), id->filename);
1.225 markus 1609: return (0);
1610: }
1.257 djm 1611: return 1;
1.225 markus 1612: }
1613:
1.20 markus 1614: int
1615: userauth_pubkey(Authctxt *authctxt)
1616: {
1.272 djm 1617: struct ssh *ssh = active_state; /* XXX */
1.117 markus 1618: Identity *id;
1.20 markus 1619: int sent = 0;
1.256 djm 1620: char *fp;
1.20 markus 1621:
1.117 markus 1622: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1623: if (id->tried++)
1624: return (0);
1.127 markus 1625: /* move key to the end of the queue */
1.117 markus 1626: TAILQ_REMOVE(&authctxt->keys, id, next);
1627: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1628: /*
1629: * send a test message if we have the public key. for
1630: * encrypted keys we cannot do this and have to load the
1631: * private key instead
1632: */
1.200 djm 1633: if (id->key != NULL) {
1.225 markus 1634: if (try_identity(id)) {
1.256 djm 1635: if ((fp = sshkey_fingerprint(id->key,
1636: options.fingerprint_hash,
1637: SSH_FP_DEFAULT)) == NULL) {
1638: error("%s: sshkey_fingerprint failed",
1639: __func__);
1640: return 0;
1641: }
1642: debug("Offering public key: %s %s %s",
1643: sshkey_type(id->key), fp, id->filename);
1644: free(fp);
1.272 djm 1645: sent = send_pubkey_test(ssh, authctxt, id);
1.200 djm 1646: }
1647: } else {
1.117 markus 1648: debug("Trying private key: %s", id->filename);
1.229 jcs 1649: id->key = load_identity_file(id);
1.117 markus 1650: if (id->key != NULL) {
1.225 markus 1651: if (try_identity(id)) {
1652: id->isprivate = 1;
1.272 djm 1653: sent = sign_and_send_pubkey(ssh,
1.200 djm 1654: authctxt, id);
1655: }
1.278 markus 1656: sshkey_free(id->key);
1.117 markus 1657: id->key = NULL;
1.251 djm 1658: id->isprivate = 0;
1.51 markus 1659: }
1660: }
1.117 markus 1661: if (sent)
1662: return (sent);
1.28 markus 1663: }
1.117 markus 1664: return (0);
1.20 markus 1665: }
1666:
1.23 markus 1667: /*
1668: * Send userauth request message specifying keyboard-interactive method.
1669: */
1670: int
1671: userauth_kbdint(Authctxt *authctxt)
1672: {
1.278 markus 1673: struct ssh *ssh = active_state; /* XXX */
1.23 markus 1674: static int attempt = 0;
1.278 markus 1675: int r;
1.23 markus 1676:
1677: if (attempt++ >= options.number_of_password_prompts)
1678: return 0;
1.82 markus 1679: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1680: if (attempt > 1 && !authctxt->info_req_seen) {
1681: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1682: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1683: return 0;
1684: }
1.23 markus 1685:
1686: debug2("userauth_kbdint");
1.278 markus 1687: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1688: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1689: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1690: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1691: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1692: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1693: options.kbd_interactive_devices : "")) != 0 ||
1694: (r = sshpkt_send(ssh)) != 0)
1695: fatal("%s: %s", __func__, ssh_err(r));
1.23 markus 1696:
1.278 markus 1697: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1698: return 1;
1699: }
1700:
1701: /*
1.46 markus 1702: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1703: */
1.218 markus 1704: int
1.261 markus 1705: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1706: {
1.260 markus 1707: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1708: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1709: char *response = NULL;
1710: u_char echo = 0;
1.32 markus 1711: u_int num_prompts, i;
1.278 markus 1712: int r;
1.23 markus 1713:
1714: debug2("input_userauth_info_req");
1715:
1716: if (authctxt == NULL)
1717: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1718:
1719: authctxt->info_req_seen = 1;
1.23 markus 1720:
1.278 markus 1721: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1722: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1723: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1724: goto out;
1.23 markus 1725: if (strlen(name) > 0)
1.116 itojun 1726: logit("%s", name);
1.23 markus 1727: if (strlen(inst) > 0)
1.116 itojun 1728: logit("%s", inst);
1.23 markus 1729:
1.278 markus 1730: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1731: goto out;
1.23 markus 1732: /*
1733: * Begin to build info response packet based on prompts requested.
1734: * We commit to providing the correct number of responses, so if
1735: * further on we run into a problem that prevents this, we have to
1736: * be sure and clean this up and send a correct error response.
1737: */
1.278 markus 1738: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1739: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1740: goto out;
1.23 markus 1741:
1.73 markus 1742: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1743: for (i = 0; i < num_prompts; i++) {
1.278 markus 1744: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1745: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1746: goto out;
1.77 markus 1747: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.278 markus 1748: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1749: goto out;
1750: freezero(response, strlen(response));
1.197 djm 1751: free(prompt);
1.278 markus 1752: response = prompt = NULL;
1.23 markus 1753: }
1.278 markus 1754: /* done with parsing incoming message. */
1755: if ((r = sshpkt_get_end(ssh)) != 0 ||
1756: (r = sshpkt_add_padding(ssh, 64)) != 0)
1757: goto out;
1758: r = sshpkt_send(ssh);
1759: out:
1760: if (response)
1761: freezero(response, strlen(response));
1762: free(prompt);
1763: free(name);
1764: free(inst);
1765: free(lang);
1766: return r;
1.68 markus 1767: }
1768:
1.100 markus 1769: static int
1.223 djm 1770: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1771: const u_char *data, size_t datalen)
1.100 markus 1772: {
1.223 djm 1773: struct sshbuf *b;
1.101 markus 1774: struct stat st;
1.100 markus 1775: pid_t pid;
1.223 djm 1776: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1777: u_char rversion = 0, version = 2;
1778: void (*osigchld)(int);
1.100 markus 1779:
1.223 djm 1780: *sigp = NULL;
1781: *lenp = 0;
1.100 markus 1782:
1.101 markus 1783: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1784: error("%s: not installed: %s", __func__, strerror(errno));
1785: return -1;
1786: }
1787: if (fflush(stdout) != 0) {
1788: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1789: return -1;
1790: }
1.100 markus 1791: if (pipe(to) < 0) {
1.223 djm 1792: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1793: return -1;
1794: }
1795: if (pipe(from) < 0) {
1.223 djm 1796: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1797: return -1;
1798: }
1799: if ((pid = fork()) < 0) {
1.223 djm 1800: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1801: return -1;
1802: }
1.223 djm 1803: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1804: if (pid == 0) {
1.174 dtucker 1805: /* keep the socket on exec */
1.223 djm 1806: fcntl(sock, F_SETFD, 0);
1.155 markus 1807: permanently_drop_suid(getuid());
1.100 markus 1808: close(from[0]);
1809: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1810: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1811: close(to[1]);
1812: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1813: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1814: close(from[1]);
1815: close(to[0]);
1.223 djm 1816: /* Close everything but stdio and the socket */
1817: for (i = STDERR_FILENO + 1; i < sock; i++)
1818: close(i);
1819: closefrom(sock + 1);
1820: debug3("%s: [child] pid=%ld, exec %s",
1821: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1822: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1823: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1824: strerror(errno));
1825: }
1826: close(from[1]);
1827: close(to[0]);
1828:
1.223 djm 1829: if ((b = sshbuf_new()) == NULL)
1830: fatal("%s: sshbuf_new failed", __func__);
1831: /* send # of sock, data to be signed */
1.253 djm 1832: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 1833: (r = sshbuf_put_string(b, data, datalen)) != 0)
1834: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1835: if (ssh_msg_send(to[1], version, b) == -1)
1836: fatal("%s: couldn't send request", __func__);
1837: sshbuf_reset(b);
1838: r = ssh_msg_recv(from[0], b);
1.101 markus 1839: close(from[0]);
1840: close(to[1]);
1.223 djm 1841: if (r < 0) {
1842: error("%s: no reply", __func__);
1843: goto fail;
1844: }
1.101 markus 1845:
1.223 djm 1846: errno = 0;
1847: while (waitpid(pid, &status, 0) < 0) {
1848: if (errno != EINTR) {
1849: error("%s: waitpid %ld: %s",
1850: __func__, (long)pid, strerror(errno));
1851: goto fail;
1852: }
1853: }
1854: if (!WIFEXITED(status)) {
1855: error("%s: exited abnormally", __func__);
1856: goto fail;
1857: }
1858: if (WEXITSTATUS(status) != 0) {
1859: error("%s: exited with status %d",
1860: __func__, WEXITSTATUS(status));
1861: goto fail;
1862: }
1863: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1864: error("%s: buffer error: %s", __func__, ssh_err(r));
1865: goto fail;
1866: }
1867: if (rversion != version) {
1868: error("%s: bad version", __func__);
1869: goto fail;
1870: }
1871: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1872: error("%s: buffer error: %s", __func__, ssh_err(r));
1873: fail:
1874: signal(SIGCHLD, osigchld);
1875: sshbuf_free(b);
1.100 markus 1876: return -1;
1877: }
1.223 djm 1878: signal(SIGCHLD, osigchld);
1879: sshbuf_free(b);
1.100 markus 1880:
1881: return 0;
1882: }
1883:
1.68 markus 1884: int
1885: userauth_hostbased(Authctxt *authctxt)
1886: {
1.272 djm 1887: struct ssh *ssh = active_state; /* XXX */
1.223 djm 1888: struct sshkey *private = NULL;
1889: struct sshbuf *b = NULL;
1890: u_char *sig = NULL, *keyblob = NULL;
1891: char *fp = NULL, *chost = NULL, *lname = NULL;
1892: size_t siglen = 0, keylen = 0;
1893: int i, r, success = 0;
1894:
1895: if (authctxt->ktypes == NULL) {
1896: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1897: authctxt->ktypes = authctxt->oktypes;
1898: }
1.213 djm 1899:
1.223 djm 1900: /*
1901: * Work through each listed type pattern in HostbasedKeyTypes,
1902: * trying each hostkey that matches the type in turn.
1903: */
1904: for (;;) {
1905: if (authctxt->active_ktype == NULL)
1906: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1907: if (authctxt->active_ktype == NULL ||
1908: *authctxt->active_ktype == '\0')
1909: break;
1910: debug3("%s: trying key type %s", __func__,
1911: authctxt->active_ktype);
1.68 markus 1912:
1.223 djm 1913: /* check for a useful key */
1914: private = NULL;
1915: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1916: if (authctxt->sensitive->keys[i] == NULL ||
1917: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1918: continue;
1919: if (match_pattern_list(
1920: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1921: authctxt->active_ktype, 0) != 1)
1.223 djm 1922: continue;
1.68 markus 1923: /* we take and free the key */
1.223 djm 1924: private = authctxt->sensitive->keys[i];
1925: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1926: break;
1927: }
1.223 djm 1928: /* Found one */
1929: if (private != NULL)
1930: break;
1931: /* No more keys of this type; advance */
1932: authctxt->active_ktype = NULL;
1.68 markus 1933: }
1.223 djm 1934: if (private == NULL) {
1935: free(authctxt->oktypes);
1936: authctxt->oktypes = authctxt->ktypes = NULL;
1937: authctxt->active_ktype = NULL;
1.109 markus 1938: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1939: goto out;
1.68 markus 1940: }
1.211 djm 1941:
1.223 djm 1942: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1943: SSH_FP_DEFAULT)) == NULL) {
1944: error("%s: sshkey_fingerprint failed", __func__);
1945: goto out;
1.68 markus 1946: }
1.223 djm 1947: debug("%s: trying hostkey %s %s",
1948: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1949:
1.84 markus 1950: /* figure out a name for the client host */
1.223 djm 1951: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1952: error("%s: cannot get local ipaddr/name", __func__);
1953: goto out;
1.84 markus 1954: }
1.223 djm 1955:
1956: /* XXX sshbuf_put_stringf? */
1957: xasprintf(&chost, "%s.", lname);
1958: debug2("%s: chost %s", __func__, chost);
1.84 markus 1959:
1.68 markus 1960: /* construct data */
1.223 djm 1961: if ((b = sshbuf_new()) == NULL) {
1962: error("%s: sshbuf_new failed", __func__);
1963: goto out;
1964: }
1965: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1966: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1967: goto out;
1968: }
1969: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1970: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1971: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 1972: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 1973: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.279 ! markus 1974: (r = sshbuf_put_cstring(b, sshkey_ssh_name(private))) != 0 ||
1.223 djm 1975: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1976: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1977: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1978: error("%s: buffer error: %s", __func__, ssh_err(r));
1979: goto out;
1980: }
1981:
1.68 markus 1982: #ifdef DEBUG_PK
1.223 djm 1983: sshbuf_dump(b, stderr);
1.68 markus 1984: #endif
1.223 djm 1985: if (authctxt->sensitive->external_keysign)
1986: r = ssh_keysign(private, &sig, &siglen,
1987: sshbuf_ptr(b), sshbuf_len(b));
1988: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1989: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1990: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1991: if (r != 0) {
1992: error("sign using hostkey %s %s failed",
1993: sshkey_ssh_name(private), fp);
1994: goto out;
1995: }
1996: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1997: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1998: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1999: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.279 ! markus 2000: (r = sshpkt_put_cstring(ssh, sshkey_ssh_name(private))) != 0 ||
1.223 djm 2001: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2002: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2003: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2004: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2005: (r = sshpkt_send(ssh)) != 0) {
2006: error("%s: packet error: %s", __func__, ssh_err(r));
2007: goto out;
2008: }
2009: success = 1;
2010:
2011: out:
1.278 markus 2012: if (sig != NULL)
2013: freezero(sig, siglen);
1.223 djm 2014: free(keyblob);
2015: free(lname);
2016: free(fp);
1.197 djm 2017: free(chost);
1.223 djm 2018: sshkey_free(private);
2019: sshbuf_free(b);
1.68 markus 2020:
1.223 djm 2021: return success;
1.23 markus 2022: }
1.170 djm 2023:
1.20 markus 2024: /* find auth method */
2025:
2026: /*
2027: * given auth method name, if configurable options permit this method fill
2028: * in auth_ident field and return true, otherwise return false.
2029: */
1.76 itojun 2030: static int
1.20 markus 2031: authmethod_is_enabled(Authmethod *method)
2032: {
2033: if (method == NULL)
2034: return 0;
2035: /* return false if options indicate this method is disabled */
2036: if (method->enabled == NULL || *method->enabled == 0)
2037: return 0;
2038: /* return false if batch mode is enabled but method needs interactive mode */
2039: if (method->batch_flag != NULL && *method->batch_flag != 0)
2040: return 0;
2041: return 1;
2042: }
2043:
1.76 itojun 2044: static Authmethod *
1.20 markus 2045: authmethod_lookup(const char *name)
1.1 markus 2046: {
1.20 markus 2047: Authmethod *method = NULL;
2048: if (name != NULL)
2049: for (method = authmethods; method->name != NULL; method++)
2050: if (strcmp(name, method->name) == 0)
2051: return method;
2052: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2053: return NULL;
2054: }
1.1 markus 2055:
1.53 markus 2056: /* XXX internal state */
2057: static Authmethod *current = NULL;
2058: static char *supported = NULL;
2059: static char *preferred = NULL;
1.105 deraadt 2060:
1.20 markus 2061: /*
2062: * Given the authentication method list sent by the server, return the
2063: * next method we should try. If the server initially sends a nil list,
1.67 markus 2064: * use a built-in default list.
1.41 stevesk 2065: */
1.76 itojun 2066: static Authmethod *
1.20 markus 2067: authmethod_get(char *authlist)
2068: {
1.53 markus 2069: char *name = NULL;
1.97 markus 2070: u_int next;
1.41 stevesk 2071:
1.20 markus 2072: /* Use a suitable default if we're passed a nil list. */
2073: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2074: authlist = options.preferred_authentications;
1.20 markus 2075:
1.53 markus 2076: if (supported == NULL || strcmp(authlist, supported) != 0) {
2077: debug3("start over, passed a different list %s", authlist);
1.197 djm 2078: free(supported);
1.53 markus 2079: supported = xstrdup(authlist);
2080: preferred = options.preferred_authentications;
2081: debug3("preferred %s", preferred);
2082: current = NULL;
2083: } else if (current != NULL && authmethod_is_enabled(current))
2084: return current;
1.20 markus 2085:
1.53 markus 2086: for (;;) {
2087: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2088: debug("No more authentication methods to try.");
1.53 markus 2089: current = NULL;
2090: return NULL;
2091: }
2092: preferred += next;
1.23 markus 2093: debug3("authmethod_lookup %s", name);
1.53 markus 2094: debug3("remaining preferred: %s", preferred);
2095: if ((current = authmethod_lookup(name)) != NULL &&
2096: authmethod_is_enabled(current)) {
1.23 markus 2097: debug3("authmethod_is_enabled %s", name);
1.109 markus 2098: debug("Next authentication method: %s", name);
1.197 djm 2099: free(name);
1.53 markus 2100: return current;
1.23 markus 2101: }
1.198 dtucker 2102: free(name);
1.1 markus 2103: }
1.53 markus 2104: }
1.1 markus 2105:
1.79 stevesk 2106: static char *
1.53 markus 2107: authmethods_get(void)
2108: {
2109: Authmethod *method = NULL;
1.278 markus 2110: struct sshbuf *b;
1.93 markus 2111: char *list;
1.278 markus 2112: int r;
1.27 provos 2113:
1.278 markus 2114: if ((b = sshbuf_new()) == NULL)
2115: fatal("%s: sshbuf_new failed", __func__);
1.53 markus 2116: for (method = authmethods; method->name != NULL; method++) {
2117: if (authmethod_is_enabled(method)) {
1.278 markus 2118: if ((r = sshbuf_putf(b, "%s%s",
2119: sshbuf_len(b) ? "," : "", method->name)) != 0)
2120: fatal("%s: buffer error: %s",
2121: __func__, ssh_err(r));
1.53 markus 2122: }
2123: }
1.278 markus 2124: if ((list = sshbuf_dup_string(b)) == NULL)
1.242 djm 2125: fatal("%s: sshbuf_dup_string failed", __func__);
1.278 markus 2126: sshbuf_free(b);
1.93 markus 2127: return list;
1.1 markus 2128: }