Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.243
1.243 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.242 2016/05/02 08:49:03 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:
1.76 itojun 88: static int
1.219 markus 89: verify_host_key_callback(Key *hostkey, struct ssh *ssh)
1.61 markus 90: {
1.75 markus 91: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 92: fatal("Host key verification failed.");
1.61 markus 93: return 0;
94: }
95:
1.186 djm 96: static char *
97: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
98: {
99: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
100: size_t maxlen;
101: struct hostkeys *hostkeys;
102: int ktype;
1.188 djm 103: u_int i;
1.186 djm 104:
105: /* Find all hostkeys for this hostname */
106: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
107: hostkeys = init_hostkeys();
1.188 djm 108: for (i = 0; i < options.num_user_hostfiles; i++)
109: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
110: for (i = 0; i < options.num_system_hostfiles; i++)
111: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 112:
113: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
114: maxlen = strlen(avail) + 1;
115: first = xmalloc(maxlen);
116: last = xmalloc(maxlen);
117: *first = *last = '\0';
118:
119: #define ALG_APPEND(to, from) \
120: do { \
121: if (*to != '\0') \
122: strlcat(to, ",", maxlen); \
123: strlcat(to, from, maxlen); \
124: } while (0)
125:
126: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 127: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 128: fatal("%s: unknown alg %s", __func__, alg);
129: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 130: sshkey_type_plain(ktype), NULL))
1.186 djm 131: ALG_APPEND(first, alg);
132: else
133: ALG_APPEND(last, alg);
134: }
135: #undef ALG_APPEND
1.216 djm 136: xasprintf(&ret, "%s%s%s", first,
137: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 138: if (*first != '\0')
139: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
140:
1.197 djm 141: free(first);
142: free(last);
143: free(hostname);
144: free(oavail);
1.186 djm 145: free_hostkeys(hostkeys);
146:
147: return ret;
148: }
149:
1.1 markus 150: void
1.186 djm 151: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 152: {
1.205 markus 153: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.231 markus 154: char *s;
1.219 markus 155: struct kex *kex;
1.221 markus 156: int r;
1.61 markus 157:
158: xxx_host = host;
159: xxx_hostaddr = hostaddr;
1.22 provos 160:
1.231 markus 161: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
162: fatal("%s: kex_names_cat", __func__);
163: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
1.60 stevesk 164: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.226 djm 165: compat_cipher_proposal(options.ciphers);
1.60 stevesk 166: myproposal[PROPOSAL_ENC_ALGS_STOC] =
1.226 djm 167: compat_cipher_proposal(options.ciphers);
1.22 provos 168: if (options.compression) {
1.47 markus 169: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 170: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 171: } else {
1.47 markus 172: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 173: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 174: }
1.226 djm 175: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
176: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
177: if (options.hostkeyalgorithms != NULL) {
178: if (kex_assemble_names(KEX_DEFAULT_PK_ALG,
179: &options.hostkeyalgorithms) != 0)
180: fatal("%s: kex_assemble_namelist", __func__);
1.88 deraadt 181: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 182: compat_pkalg_proposal(options.hostkeyalgorithms);
1.226 djm 183: } else {
1.225 markus 184: /* Enforce default */
185: options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
1.186 djm 186: /* Prefer algorithms that we already have keys for */
187: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 188: compat_pkalg_proposal(
189: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 190: }
1.115 markus 191:
1.196 dtucker 192: if (options.rekey_limit || options.rekey_interval)
193: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
194: (time_t)options.rekey_interval);
1.22 provos 195:
1.65 markus 196: /* start key exchange */
1.221 markus 197: if ((r = kex_setup(active_state, myproposal)) != 0)
198: fatal("kex_setup: %s", ssh_err(r));
1.219 markus 199: kex = active_state->kex;
1.207 markus 200: #ifdef WITH_OPENSSL
1.111 markus 201: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 202: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.243 ! djm 203: kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
! 204: kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
! 205: kex->kex[KEX_DH_GRP18_SHA512] = 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;
1.22 provos 214:
1.219 markus 215: dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
1.173 andreas 216:
1.231 markus 217: /* remove ext-info from the KEX proposals for rekeying */
218: myproposal[PROPOSAL_KEX_ALGS] =
219: compat_kex_proposal(options.kex_algorithms);
220: if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
221: fatal("kex_prop2buf: %s", ssh_err(r));
1.62 markus 222:
223: session_id2 = kex->session_id;
224: session_id2_len = kex->session_id_len;
1.22 provos 225:
226: #ifdef DEBUG_KEXDH
227: /* send 1st encrypted/maced/compressed message */
228: packet_start(SSH2_MSG_IGNORE);
229: packet_put_cstring("markus");
230: packet_send();
231: packet_write_wait();
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:
1.231 markus 285: int input_userauth_service_accept(int, u_int32_t, void *);
286: int input_userauth_ext_info(int, u_int32_t, void *);
1.218 markus 287: int input_userauth_success(int, u_int32_t, void *);
288: int input_userauth_success_unexpected(int, u_int32_t, void *);
289: int input_userauth_failure(int, u_int32_t, void *);
290: int input_userauth_banner(int, u_int32_t, void *);
291: int input_userauth_error(int, u_int32_t, void *);
292: int input_userauth_info_req(int, u_int32_t, void *);
293: int input_userauth_pk_ok(int, u_int32_t, void *);
294: int input_userauth_passwd_changereq(int, u_int32_t, void *);
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);
1.218 markus 304: int input_gssapi_response(int type, u_int32_t, void *);
305: int input_gssapi_token(int type, u_int32_t, void *);
306: int input_gssapi_hash(int type, u_int32_t, void *);
307: int input_gssapi_error(int, u_int32_t, void *);
308: int input_gssapi_errtok(int, u_int32_t, void *);
1.121 markus 309: #endif
310:
1.86 itojun 311: void userauth(Authctxt *, char *);
1.51 markus 312:
1.117 markus 313: static int sign_and_send_pubkey(Authctxt *, Identity *);
314: static void pubkey_prepare(Authctxt *);
315: static void pubkey_cleanup(Authctxt *);
1.229 jcs 316: static Key *load_identity_file(Identity *);
1.76 itojun 317:
318: static Authmethod *authmethod_get(char *authlist);
319: static Authmethod *authmethod_lookup(const char *name);
320: static char *authmethods_get(void);
1.20 markus 321:
322: Authmethod authmethods[] = {
1.121 markus 323: #ifdef GSSAPI
1.132 markus 324: {"gssapi-with-mic",
1.121 markus 325: userauth_gssapi,
1.170 djm 326: NULL,
1.121 markus 327: &options.gss_authentication,
328: NULL},
329: #endif
1.81 markus 330: {"hostbased",
331: userauth_hostbased,
1.170 djm 332: NULL,
1.81 markus 333: &options.hostbased_authentication,
334: NULL},
1.20 markus 335: {"publickey",
336: userauth_pubkey,
1.170 djm 337: NULL,
1.28 markus 338: &options.pubkey_authentication,
1.20 markus 339: NULL},
1.81 markus 340: {"keyboard-interactive",
341: userauth_kbdint,
1.170 djm 342: NULL,
1.81 markus 343: &options.kbd_interactive_authentication,
344: &options.batch_mode},
1.20 markus 345: {"password",
346: userauth_passwd,
1.170 djm 347: NULL,
1.20 markus 348: &options.password_authentication,
1.23 markus 349: &options.batch_mode},
350: {"none",
351: userauth_none,
352: NULL,
1.170 djm 353: NULL,
1.23 markus 354: NULL},
1.170 djm 355: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 356: };
357:
358: void
1.68 markus 359: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 360: Sensitive *sensitive)
1.20 markus 361: {
1.231 markus 362: struct ssh *ssh = active_state;
1.20 markus 363: Authctxt authctxt;
1.231 markus 364: int r;
1.39 markus 365:
1.73 markus 366: if (options.challenge_response_authentication)
1.39 markus 367: options.kbd_interactive_authentication = 1;
1.53 markus 368: if (options.preferred_authentications == NULL)
369: options.preferred_authentications = authmethods_get();
370:
1.20 markus 371: /* setup authentication context */
1.82 markus 372: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 373: pubkey_prepare(&authctxt);
1.20 markus 374: authctxt.server_user = server_user;
1.68 markus 375: authctxt.local_user = local_user;
1.20 markus 376: authctxt.host = host;
377: authctxt.service = "ssh-connection"; /* service name */
378: authctxt.success = 0;
1.23 markus 379: authctxt.method = authmethod_lookup("none");
1.51 markus 380: authctxt.authlist = NULL;
1.121 markus 381: authctxt.methoddata = NULL;
1.100 markus 382: authctxt.sensitive = sensitive;
1.223 djm 383: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 384: authctxt.info_req_seen = 0;
1.215 djm 385: authctxt.agent_fd = -1;
1.23 markus 386: if (authctxt.method == NULL)
387: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 388:
1.231 markus 389: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
390: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
391: (r = sshpkt_send(ssh)) != 0)
392: fatal("%s: %s", __func__, ssh_err(r));
393:
394: ssh_dispatch_init(ssh, &input_userauth_error);
395: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
396: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
397: ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
1.20 markus 398:
1.117 markus 399: pubkey_cleanup(&authctxt);
1.231 markus 400: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 401:
1.109 markus 402: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 403: }
1.119 markus 404:
1.231 markus 405: /* ARGSUSED */
406: int
407: input_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt)
408: {
409: Authctxt *authctxt = ctxt;
410: struct ssh *ssh = active_state;
411: int r;
412:
413: if (ssh_packet_remaining(ssh) > 0) {
414: char *reply;
415:
416: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
417: goto out;
418: debug2("service_accept: %s", reply);
419: free(reply);
420: } else {
421: debug2("buggy server: service_accept w/o service");
422: }
423: if ((r = sshpkt_get_end(ssh)) != 0)
424: goto out;
425: debug("SSH2_MSG_SERVICE_ACCEPT received");
426:
427: /* initial userauth request */
428: userauth_none(authctxt);
429:
430: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
431: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
432: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
433: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
434: r = 0;
435: out:
436: return r;
437: }
438:
439: /* ARGSUSED */
440: int
441: input_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt)
442: {
443: return kex_input_ext_info(type, seqnr, active_state);
444: }
445:
1.20 markus 446: void
1.51 markus 447: userauth(Authctxt *authctxt, char *authlist)
448: {
1.170 djm 449: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
450: authctxt->method->cleanup(authctxt);
451:
1.197 djm 452: free(authctxt->methoddata);
453: authctxt->methoddata = NULL;
1.51 markus 454: if (authlist == NULL) {
455: authlist = authctxt->authlist;
456: } else {
1.197 djm 457: free(authctxt->authlist);
1.51 markus 458: authctxt->authlist = authlist;
459: }
460: for (;;) {
461: Authmethod *method = authmethod_get(authlist);
462: if (method == NULL)
463: fatal("Permission denied (%s).", authlist);
464: authctxt->method = method;
1.119 markus 465:
466: /* reset the per method handler */
467: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
468: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
469:
470: /* and try new method */
1.51 markus 471: if (method->userauth(authctxt) != 0) {
472: debug2("we sent a %s packet, wait for reply", method->name);
473: break;
474: } else {
475: debug2("we did not send a packet, disable method");
476: method->enabled = NULL;
477: }
478: }
479: }
1.105 deraadt 480:
1.169 djm 481: /* ARGSUSED */
1.218 markus 482: int
1.92 markus 483: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 484: {
1.35 markus 485: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 486: "type %d", type);
1.218 markus 487: return 0;
1.35 markus 488: }
1.105 deraadt 489:
1.169 djm 490: /* ARGSUSED */
1.218 markus 491: int
1.92 markus 492: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 493: {
1.166 djm 494: char *msg, *raw, *lang;
495: u_int len;
1.126 deraadt 496:
1.35 markus 497: debug3("input_userauth_banner");
1.166 djm 498: raw = packet_get_string(&len);
1.35 markus 499: lang = packet_get_string(NULL);
1.167 markus 500: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 501: if (len > 65536)
502: len = 65536;
1.168 deraadt 503: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 504: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 505: fprintf(stderr, "%s", msg);
1.197 djm 506: free(msg);
1.166 djm 507: }
1.197 djm 508: free(raw);
509: free(lang);
1.218 markus 510: return 0;
1.20 markus 511: }
1.105 deraadt 512:
1.169 djm 513: /* ARGSUSED */
1.218 markus 514: int
1.92 markus 515: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 516: {
517: Authctxt *authctxt = ctxt;
1.172 djm 518:
1.20 markus 519: if (authctxt == NULL)
520: fatal("input_userauth_success: no authentication context");
1.197 djm 521: free(authctxt->authlist);
522: authctxt->authlist = NULL;
1.172 djm 523: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
524: authctxt->method->cleanup(authctxt);
1.197 djm 525: free(authctxt->methoddata);
526: authctxt->methoddata = NULL;
1.20 markus 527: authctxt->success = 1; /* break out */
1.218 markus 528: return 0;
1.20 markus 529: }
1.105 deraadt 530:
1.218 markus 531: int
1.172 djm 532: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
533: {
534: Authctxt *authctxt = ctxt;
535:
536: if (authctxt == NULL)
537: fatal("%s: no authentication context", __func__);
538:
539: fatal("Unexpected authentication success during %s.",
540: authctxt->method->name);
1.218 markus 541: return 0;
1.172 djm 542: }
543:
1.169 djm 544: /* ARGSUSED */
1.218 markus 545: int
1.92 markus 546: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 547: {
548: Authctxt *authctxt = ctxt;
549: char *authlist = NULL;
550: int partial;
551:
552: if (authctxt == NULL)
553: fatal("input_userauth_failure: no authentication context");
554:
1.23 markus 555: authlist = packet_get_string(NULL);
1.20 markus 556: partial = packet_get_char();
1.90 markus 557: packet_check_eom();
1.20 markus 558:
1.193 markus 559: if (partial != 0) {
1.116 itojun 560: logit("Authenticated with partial success.");
1.193 markus 561: /* reset state */
562: pubkey_cleanup(authctxt);
563: pubkey_prepare(authctxt);
564: }
1.109 markus 565: debug("Authentications that can continue: %s", authlist);
1.20 markus 566:
1.51 markus 567: userauth(authctxt, authlist);
1.218 markus 568: return 0;
1.51 markus 569: }
1.169 djm 570:
571: /* ARGSUSED */
1.218 markus 572: int
1.92 markus 573: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 574: {
575: Authctxt *authctxt = ctxt;
576: Key *key = NULL;
1.117 markus 577: Identity *id = NULL;
1.51 markus 578: Buffer b;
1.96 markus 579: int pktype, sent = 0;
580: u_int alen, blen;
581: char *pkalg, *fp;
582: u_char *pkblob;
1.51 markus 583:
584: if (authctxt == NULL)
585: fatal("input_userauth_pk_ok: no authentication context");
586: if (datafellows & SSH_BUG_PKOK) {
587: /* this is similar to SSH_BUG_PKAUTH */
588: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
589: pkblob = packet_get_string(&blen);
590: buffer_init(&b);
591: buffer_append(&b, pkblob, blen);
592: pkalg = buffer_get_string(&b, &alen);
593: buffer_free(&b);
594: } else {
595: pkalg = packet_get_string(&alen);
596: pkblob = packet_get_string(&blen);
597: }
1.90 markus 598: packet_check_eom();
1.51 markus 599:
1.117 markus 600: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 601:
1.117 markus 602: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
603: debug("unknown pkalg %s", pkalg);
604: goto done;
605: }
606: if ((key = key_from_blob(pkblob, blen)) == NULL) {
607: debug("no key from blob. pkalg %s", pkalg);
608: goto done;
609: }
610: if (key->type != pktype) {
611: error("input_userauth_pk_ok: type mismatch "
612: "for decoded key (received %d, expected %d)",
613: key->type, pktype);
614: goto done;
615: }
1.222 djm 616: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
617: SSH_FP_DEFAULT)) == NULL)
618: goto done;
1.117 markus 619: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 620: free(fp);
1.117 markus 621:
1.127 markus 622: /*
623: * search keys in the reverse order, because last candidate has been
624: * moved to the end of the queue. this also avoids confusion by
625: * duplicate keys
626: */
1.136 henning 627: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 628: if (key_equal(key, id->key)) {
629: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 630: break;
631: }
1.117 markus 632: }
633: done:
1.51 markus 634: if (key != NULL)
635: key_free(key);
1.197 djm 636: free(pkalg);
637: free(pkblob);
1.51 markus 638:
1.106 deraadt 639: /* try another method if we did not send a packet */
1.51 markus 640: if (sent == 0)
641: userauth(authctxt, NULL);
1.218 markus 642: return 0;
1.20 markus 643: }
1.121 markus 644:
645: #ifdef GSSAPI
1.133 djm 646: int
1.121 markus 647: userauth_gssapi(Authctxt *authctxt)
648: {
649: Gssctxt *gssctxt = NULL;
1.128 avsm 650: static gss_OID_set gss_supported = NULL;
1.139 djm 651: static u_int mech = 0;
1.121 markus 652: OM_uint32 min;
653: int ok = 0;
654:
655: /* Try one GSSAPI method at a time, rather than sending them all at
656: * once. */
657:
1.128 avsm 658: if (gss_supported == NULL)
659: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 660:
661: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 662: while (mech < gss_supported->count && !ok) {
1.121 markus 663: /* My DER encoding requires length<128 */
1.128 avsm 664: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 665: ssh_gssapi_check_mechanism(&gssctxt,
666: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 667: ok = 1; /* Mechanism works */
668: } else {
669: mech++;
670: }
671: }
672:
1.161 djm 673: if (!ok)
1.139 djm 674: return 0;
1.121 markus 675:
676: authctxt->methoddata=(void *)gssctxt;
677:
678: packet_start(SSH2_MSG_USERAUTH_REQUEST);
679: packet_put_cstring(authctxt->server_user);
680: packet_put_cstring(authctxt->service);
681: packet_put_cstring(authctxt->method->name);
682:
683: packet_put_int(1);
684:
1.129 markus 685: packet_put_int((gss_supported->elements[mech].length) + 2);
686: packet_put_char(SSH_GSS_OIDTYPE);
687: packet_put_char(gss_supported->elements[mech].length);
688: packet_put_raw(gss_supported->elements[mech].elements,
689: gss_supported->elements[mech].length);
1.121 markus 690:
691: packet_send();
692:
693: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
694: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
695: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
696: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
697:
698: mech++; /* Move along to next candidate */
699:
700: return 1;
701: }
702:
1.130 markus 703: static OM_uint32
704: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
705: {
706: Authctxt *authctxt = ctxt;
707: Gssctxt *gssctxt = authctxt->methoddata;
708: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 709: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
710: gss_buffer_desc gssbuf;
1.132 markus 711: OM_uint32 status, ms, flags;
712: Buffer b;
1.133 djm 713:
1.130 markus 714: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 715: recv_tok, &send_tok, &flags);
1.130 markus 716:
717: if (send_tok.length > 0) {
718: if (GSS_ERROR(status))
719: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
720: else
721: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 722:
1.130 markus 723: packet_put_string(send_tok.value, send_tok.length);
724: packet_send();
725: gss_release_buffer(&ms, &send_tok);
726: }
1.133 djm 727:
1.130 markus 728: if (status == GSS_S_COMPLETE) {
1.132 markus 729: /* send either complete or MIC, depending on mechanism */
730: if (!(flags & GSS_C_INTEG_FLAG)) {
731: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
732: packet_send();
733: } else {
734: ssh_gssapi_buildmic(&b, authctxt->server_user,
735: authctxt->service, "gssapi-with-mic");
736:
737: gssbuf.value = buffer_ptr(&b);
738: gssbuf.length = buffer_len(&b);
1.133 djm 739:
1.132 markus 740: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 741:
1.132 markus 742: if (!GSS_ERROR(status)) {
743: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
744: packet_put_string(mic.value, mic.length);
1.133 djm 745:
1.132 markus 746: packet_send();
747: }
1.133 djm 748:
1.132 markus 749: buffer_free(&b);
750: gss_release_buffer(&ms, &mic);
1.133 djm 751: }
1.130 markus 752: }
1.133 djm 753:
1.130 markus 754: return status;
755: }
756:
1.169 djm 757: /* ARGSUSED */
1.220 djm 758: int
1.121 markus 759: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
760: {
761: Authctxt *authctxt = ctxt;
762: Gssctxt *gssctxt;
763: int oidlen;
764: char *oidv;
765:
766: if (authctxt == NULL)
767: fatal("input_gssapi_response: no authentication context");
768: gssctxt = authctxt->methoddata;
769:
770: /* Setup our OID */
771: oidv = packet_get_string(&oidlen);
772:
1.129 markus 773: if (oidlen <= 2 ||
774: oidv[0] != SSH_GSS_OIDTYPE ||
775: oidv[1] != oidlen - 2) {
1.197 djm 776: free(oidv);
1.129 markus 777: debug("Badly encoded mechanism OID received");
778: userauth(authctxt, NULL);
1.220 djm 779: return 0;
1.121 markus 780: }
1.129 markus 781:
782: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
783: fatal("Server returned different OID than expected");
1.121 markus 784:
785: packet_check_eom();
786:
1.197 djm 787: free(oidv);
1.121 markus 788:
1.130 markus 789: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 790: /* Start again with next method on list */
791: debug("Trying to start again");
792: userauth(authctxt, NULL);
1.220 djm 793: return 0;
1.121 markus 794: }
1.220 djm 795: return 0;
1.121 markus 796: }
797:
1.169 djm 798: /* ARGSUSED */
1.220 djm 799: int
1.121 markus 800: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
801: {
802: Authctxt *authctxt = ctxt;
803: gss_buffer_desc recv_tok;
1.130 markus 804: OM_uint32 status;
1.121 markus 805: u_int slen;
806:
807: if (authctxt == NULL)
808: fatal("input_gssapi_response: no authentication context");
809:
810: recv_tok.value = packet_get_string(&slen);
811: recv_tok.length = slen; /* safe typecast */
812:
813: packet_check_eom();
814:
1.130 markus 815: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 816:
1.197 djm 817: free(recv_tok.value);
1.121 markus 818:
819: if (GSS_ERROR(status)) {
820: /* Start again with the next method in the list */
821: userauth(authctxt, NULL);
1.220 djm 822: return 0;
1.121 markus 823: }
1.220 djm 824: return 0;
1.121 markus 825: }
826:
1.169 djm 827: /* ARGSUSED */
1.220 djm 828: int
1.121 markus 829: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
830: {
831: Authctxt *authctxt = ctxt;
832: Gssctxt *gssctxt;
833: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
834: gss_buffer_desc recv_tok;
1.194 djm 835: OM_uint32 ms;
1.123 deraadt 836: u_int len;
1.121 markus 837:
838: if (authctxt == NULL)
839: fatal("input_gssapi_response: no authentication context");
840: gssctxt = authctxt->methoddata;
841:
1.123 deraadt 842: recv_tok.value = packet_get_string(&len);
843: recv_tok.length = len;
1.121 markus 844:
845: packet_check_eom();
846:
847: /* Stick it into GSSAPI and see what it says */
1.194 djm 848: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 849: &recv_tok, &send_tok, NULL);
1.121 markus 850:
1.197 djm 851: free(recv_tok.value);
1.121 markus 852: gss_release_buffer(&ms, &send_tok);
853:
854: /* Server will be returning a failed packet after this one */
1.220 djm 855: return 0;
1.121 markus 856: }
857:
1.169 djm 858: /* ARGSUSED */
1.220 djm 859: int
1.121 markus 860: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
861: {
862: char *msg;
863: char *lang;
864:
1.194 djm 865: /* maj */(void)packet_get_int();
866: /* min */(void)packet_get_int();
1.121 markus 867: msg=packet_get_string(NULL);
868: lang=packet_get_string(NULL);
869:
870: packet_check_eom();
871:
1.143 stevesk 872: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 873: free(msg);
874: free(lang);
1.220 djm 875: return 0;
1.121 markus 876: }
877: #endif /* GSSAPI */
1.20 markus 878:
1.1 markus 879: int
1.23 markus 880: userauth_none(Authctxt *authctxt)
881: {
882: /* initial userauth request */
883: packet_start(SSH2_MSG_USERAUTH_REQUEST);
884: packet_put_cstring(authctxt->server_user);
885: packet_put_cstring(authctxt->service);
886: packet_put_cstring(authctxt->method->name);
887: packet_send();
888: return 1;
889: }
890:
891: int
1.20 markus 892: userauth_passwd(Authctxt *authctxt)
1.1 markus 893: {
1.6 markus 894: static int attempt = 0;
1.99 markus 895: char prompt[150];
1.1 markus 896: char *password;
1.175 dtucker 897: const char *host = options.host_key_alias ? options.host_key_alias :
898: authctxt->host;
1.6 markus 899:
1.13 todd 900: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 901: return 0;
1.13 todd 902:
1.87 deraadt 903: if (attempt != 1)
1.13 todd 904: error("Permission denied, please try again.");
1.1 markus 905:
1.43 itojun 906: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 907: authctxt->server_user, host);
1.1 markus 908: password = read_passphrase(prompt, 0);
909: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 910: packet_put_cstring(authctxt->server_user);
911: packet_put_cstring(authctxt->service);
1.23 markus 912: packet_put_cstring(authctxt->method->name);
1.1 markus 913: packet_put_char(0);
1.49 markus 914: packet_put_cstring(password);
1.204 djm 915: explicit_bzero(password, strlen(password));
1.197 djm 916: free(password);
1.85 markus 917: packet_add_padding(64);
1.1 markus 918: packet_send();
1.99 markus 919:
1.104 deraadt 920: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 921: &input_userauth_passwd_changereq);
922:
1.1 markus 923: return 1;
924: }
1.169 djm 925:
1.99 markus 926: /*
927: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
928: */
1.169 djm 929: /* ARGSUSED */
1.218 markus 930: int
1.153 djm 931: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 932: {
933: Authctxt *authctxt = ctxt;
934: char *info, *lang, *password = NULL, *retype = NULL;
935: char prompt[150];
1.175 dtucker 936: const char *host = options.host_key_alias ? options.host_key_alias :
937: authctxt->host;
1.99 markus 938:
939: debug2("input_userauth_passwd_changereq");
940:
941: if (authctxt == NULL)
942: fatal("input_userauth_passwd_changereq: "
943: "no authentication context");
944:
945: info = packet_get_string(NULL);
946: lang = packet_get_string(NULL);
947: if (strlen(info) > 0)
1.116 itojun 948: logit("%s", info);
1.197 djm 949: free(info);
950: free(lang);
1.99 markus 951: packet_start(SSH2_MSG_USERAUTH_REQUEST);
952: packet_put_cstring(authctxt->server_user);
953: packet_put_cstring(authctxt->service);
954: packet_put_cstring(authctxt->method->name);
955: packet_put_char(1); /* additional info */
1.104 deraadt 956: snprintf(prompt, sizeof(prompt),
1.99 markus 957: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 958: authctxt->server_user, host);
1.99 markus 959: password = read_passphrase(prompt, 0);
960: packet_put_cstring(password);
1.204 djm 961: explicit_bzero(password, strlen(password));
1.197 djm 962: free(password);
1.99 markus 963: password = NULL;
964: while (password == NULL) {
1.104 deraadt 965: snprintf(prompt, sizeof(prompt),
1.99 markus 966: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 967: authctxt->server_user, host);
1.99 markus 968: password = read_passphrase(prompt, RP_ALLOW_EOF);
969: if (password == NULL) {
970: /* bail out */
1.218 markus 971: return 0;
1.99 markus 972: }
1.104 deraadt 973: snprintf(prompt, sizeof(prompt),
1.99 markus 974: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 975: authctxt->server_user, host);
1.99 markus 976: retype = read_passphrase(prompt, 0);
977: if (strcmp(password, retype) != 0) {
1.204 djm 978: explicit_bzero(password, strlen(password));
1.197 djm 979: free(password);
1.116 itojun 980: logit("Mismatch; try again, EOF to quit.");
1.99 markus 981: password = NULL;
982: }
1.204 djm 983: explicit_bzero(retype, strlen(retype));
1.197 djm 984: free(retype);
1.99 markus 985: }
986: packet_put_cstring(password);
1.204 djm 987: explicit_bzero(password, strlen(password));
1.197 djm 988: free(password);
1.99 markus 989: packet_add_padding(64);
990: packet_send();
1.104 deraadt 991:
992: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 993: &input_userauth_passwd_changereq);
1.218 markus 994: return 0;
1.117 markus 995: }
996:
1.231 markus 997: static const char *
998: identity_sign_encode(struct identity *id)
999: {
1000: struct ssh *ssh = active_state;
1001:
1002: if (id->key->type == KEY_RSA) {
1003: switch (ssh->kex->rsa_sha2) {
1004: case 256:
1005: return "rsa-sha2-256";
1006: case 512:
1007: return "rsa-sha2-512";
1008: }
1009: }
1010: return key_ssh_name(id->key);
1011: }
1012:
1.117 markus 1013: static int
1.214 djm 1014: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1015: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1016: {
1017: Key *prv;
1018: int ret;
1.231 markus 1019: const char *alg;
1020:
1021: alg = identity_sign_encode(id);
1.99 markus 1022:
1.117 markus 1023: /* the agent supports this key */
1.230 djm 1024: if (id->agent_fd != -1)
1.214 djm 1025: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.231 markus 1026: data, datalen, alg, compat);
1.214 djm 1027:
1.117 markus 1028: /*
1029: * we have already loaded the private key or
1030: * the private key is stored in external hardware
1031: */
1.209 djm 1032: if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
1.231 markus 1033: return (sshkey_sign(id->key, sigp, lenp, data, datalen, alg,
1.214 djm 1034: compat));
1.117 markus 1035: /* load the private key from the file */
1.229 jcs 1036: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1037: return SSH_ERR_KEY_NOT_FOUND;
1.231 markus 1038: ret = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat);
1.214 djm 1039: sshkey_free(prv);
1.117 markus 1040: return (ret);
1.51 markus 1041: }
1042:
1.76 itojun 1043: static int
1.117 markus 1044: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1045: {
1046: Buffer b;
1.227 djm 1047: Identity *private_id;
1.32 markus 1048: u_char *blob, *signature;
1.214 djm 1049: size_t slen;
1.227 djm 1050: u_int bloblen, skip = 0;
1051: int matched, ret = -1, have_sig = 1;
1.182 djm 1052: char *fp;
1.1 markus 1053:
1.222 djm 1054: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1055: SSH_FP_DEFAULT)) == NULL)
1056: return 0;
1.227 djm 1057: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1058: free(fp);
1.51 markus 1059:
1.117 markus 1060: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1061: /* we cannot handle this key */
1.30 markus 1062: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1063: return 0;
1064: }
1.1 markus 1065: /* data to be signed */
1066: buffer_init(&b);
1.26 markus 1067: if (datafellows & SSH_OLD_SESSIONID) {
1068: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1069: skip = session_id2_len;
1.26 markus 1070: } else {
1.14 markus 1071: buffer_put_string(&b, session_id2, session_id2_len);
1072: skip = buffer_len(&b);
1073: }
1.1 markus 1074: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1075: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1076: buffer_put_cstring(&b,
1.30 markus 1077: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1078: "ssh-userauth" :
1.20 markus 1079: authctxt->service);
1.30 markus 1080: if (datafellows & SSH_BUG_PKAUTH) {
1081: buffer_put_char(&b, have_sig);
1082: } else {
1083: buffer_put_cstring(&b, authctxt->method->name);
1084: buffer_put_char(&b, have_sig);
1.231 markus 1085: buffer_put_cstring(&b, identity_sign_encode(id));
1.30 markus 1086: }
1.1 markus 1087: buffer_put_string(&b, blob, bloblen);
1088:
1.227 djm 1089: /*
1090: * If the key is an certificate, try to find a matching private key
1091: * and use it to complete the signature.
1.241 djm 1092: * If no such private key exists, fall back to trying the certificate
1093: * key itself in case it has a private half already loaded.
1.227 djm 1094: */
1095: if (key_is_cert(id->key)) {
1096: matched = 0;
1097: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1098: if (sshkey_equal_public(id->key, private_id->key) &&
1099: id->key->type != private_id->key->type) {
1100: id = private_id;
1101: matched = 1;
1102: break;
1103: }
1104: }
1105: if (matched) {
1106: debug2("%s: using private key \"%s\"%s for "
1107: "certificate", __func__, id->filename,
1108: id->agent_fd != -1 ? " from agent" : "");
1109: } else {
1.240 djm 1110: debug("%s: no separate private key for certificate "
1.227 djm 1111: "\"%s\"", __func__, id->filename);
1112: }
1113: }
1114:
1.1 markus 1115: /* generate signature */
1.117 markus 1116: ret = identity_sign(id, &signature, &slen,
1.214 djm 1117: buffer_ptr(&b), buffer_len(&b), datafellows);
1118: if (ret != 0) {
1.239 djm 1119: if (ret != SSH_ERR_KEY_NOT_FOUND)
1120: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1121: free(blob);
1.17 markus 1122: buffer_free(&b);
1123: return 0;
1124: }
1.28 markus 1125: #ifdef DEBUG_PK
1.1 markus 1126: buffer_dump(&b);
1127: #endif
1.30 markus 1128: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1129: buffer_clear(&b);
1130: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1131: skip = session_id2_len;
1.10 markus 1132: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1133: buffer_put_cstring(&b, authctxt->server_user);
1134: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1135: buffer_put_cstring(&b, authctxt->method->name);
1136: buffer_put_char(&b, have_sig);
1.30 markus 1137: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1138: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1139: buffer_put_string(&b, blob, bloblen);
1140: }
1.197 djm 1141: free(blob);
1.51 markus 1142:
1.1 markus 1143: /* append signature */
1144: buffer_put_string(&b, signature, slen);
1.197 djm 1145: free(signature);
1.1 markus 1146:
1147: /* skip session id and packet type */
1.14 markus 1148: if (buffer_len(&b) < skip + 1)
1.20 markus 1149: fatal("userauth_pubkey: internal error");
1.14 markus 1150: buffer_consume(&b, skip + 1);
1.1 markus 1151:
1152: /* put remaining data from buffer into packet */
1153: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1154: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1155: buffer_free(&b);
1156: packet_send();
1.17 markus 1157:
1158: return 1;
1.16 markus 1159: }
1160:
1.76 itojun 1161: static int
1.117 markus 1162: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1163: {
1.51 markus 1164: u_char *blob;
1.97 markus 1165: u_int bloblen, have_sig = 0;
1.20 markus 1166:
1.51 markus 1167: debug3("send_pubkey_test");
1.16 markus 1168:
1.117 markus 1169: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1170: /* we cannot handle this key */
1171: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1172: return 0;
1173: }
1.51 markus 1174: /* register callback for USERAUTH_PK_OK message */
1175: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1176:
1177: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1178: packet_put_cstring(authctxt->server_user);
1179: packet_put_cstring(authctxt->service);
1180: packet_put_cstring(authctxt->method->name);
1181: packet_put_char(have_sig);
1182: if (!(datafellows & SSH_BUG_PKAUTH))
1.231 markus 1183: packet_put_cstring(identity_sign_encode(id));
1.51 markus 1184: packet_put_string(blob, bloblen);
1.197 djm 1185: free(blob);
1.51 markus 1186: packet_send();
1187: return 1;
1188: }
1189:
1.76 itojun 1190: static Key *
1.229 jcs 1191: load_identity_file(Identity *id)
1.51 markus 1192: {
1.238 jsg 1193: Key *private = NULL;
1.229 jcs 1194: char prompt[300], *passphrase, *comment;
1.215 djm 1195: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1196: struct stat st;
1.16 markus 1197:
1.229 jcs 1198: if (stat(id->filename, &st) < 0) {
1199: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1200: id->filename, strerror(errno));
1.52 markus 1201: return NULL;
1202: }
1.214 djm 1203: snprintf(prompt, sizeof prompt,
1.229 jcs 1204: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1205: for (i = 0; i <= options.number_of_password_prompts; i++) {
1206: if (i == 0)
1207: passphrase = "";
1208: else {
1.20 markus 1209: passphrase = read_passphrase(prompt, 0);
1.214 djm 1210: if (*passphrase == '\0') {
1.20 markus 1211: debug2("no passphrase given, try next key");
1.214 djm 1212: free(passphrase);
1213: break;
1214: }
1215: }
1.229 jcs 1216: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1217: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1218: case 0:
1219: break;
1220: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1221: if (options.batch_mode) {
1222: quit = 1;
1223: break;
1224: }
1.215 djm 1225: if (i != 0)
1226: debug2("bad passphrase given, try again...");
1.214 djm 1227: break;
1228: case SSH_ERR_SYSTEM_ERROR:
1229: if (errno == ENOENT) {
1230: debug2("Load key \"%s\": %s",
1.229 jcs 1231: id->filename, ssh_err(r));
1.51 markus 1232: quit = 1;
1.214 djm 1233: break;
1.20 markus 1234: }
1.214 djm 1235: /* FALLTHROUGH */
1236: default:
1.229 jcs 1237: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1238: quit = 1;
1239: break;
1240: }
1.230 djm 1241: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1242: !(id->key && id->isprivate))
1243: maybe_add_key_to_agent(id->filename, private, comment,
1244: passphrase);
1.214 djm 1245: if (i > 0) {
1.204 djm 1246: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1247: free(passphrase);
1.16 markus 1248: }
1.232 mmcc 1249: free(comment);
1.214 djm 1250: if (private != NULL || quit)
1251: break;
1.16 markus 1252: }
1.51 markus 1253: return private;
1254: }
1255:
1.117 markus 1256: /*
1257: * try keys in the following order:
1.227 djm 1258: * 1. certificates listed in the config file
1259: * 2. other input certificates
1260: * 3. agent keys that are found in the config file
1261: * 4. other agent keys
1262: * 5. keys that are only listed in the config file
1.117 markus 1263: */
1264: static void
1265: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1266: {
1.214 djm 1267: struct identity *id, *id2, *tmp;
1268: struct idlist agent, files, *preferred;
1269: struct sshkey *key;
1.230 djm 1270: int agent_fd = -1, i, r, found;
1.214 djm 1271: size_t j;
1272: struct ssh_identitylist *idlist;
1.51 markus 1273:
1.117 markus 1274: TAILQ_INIT(&agent); /* keys from the agent */
1275: TAILQ_INIT(&files); /* keys from the config file */
1276: preferred = &authctxt->keys;
1277: TAILQ_INIT(preferred); /* preferred order of keys */
1278:
1.190 djm 1279: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1280: for (i = 0; i < options.num_identity_files; i++) {
1281: key = options.identity_keys[i];
1282: if (key && key->type == KEY_RSA1)
1.180 djm 1283: continue;
1284: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1285: continue;
1286: options.identity_keys[i] = NULL;
1.150 djm 1287: id = xcalloc(1, sizeof(*id));
1.230 djm 1288: id->agent_fd = -1;
1.117 markus 1289: id->key = key;
1290: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1291: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1292: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1293: }
1294: /* Prefer PKCS11 keys that are explicitly listed */
1295: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1.209 djm 1296: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1297: continue;
1298: found = 0;
1299: TAILQ_FOREACH(id2, &files, next) {
1300: if (id2->key == NULL ||
1.209 djm 1301: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1302: continue;
1.214 djm 1303: if (sshkey_equal(id->key, id2->key)) {
1.190 djm 1304: TAILQ_REMOVE(&files, id, next);
1305: TAILQ_INSERT_TAIL(preferred, id, next);
1306: found = 1;
1307: break;
1308: }
1309: }
1310: /* If IdentitiesOnly set and key not found then don't use it */
1311: if (!found && options.identities_only) {
1312: TAILQ_REMOVE(&files, id, next);
1.203 tedu 1313: explicit_bzero(id, sizeof(*id));
1.190 djm 1314: free(id);
1315: }
1.227 djm 1316: }
1317: /* list of certificates specified by user */
1318: for (i = 0; i < options.num_certificate_files; i++) {
1319: key = options.certificates[i];
1320: if (!key_is_cert(key) || key->cert == NULL ||
1321: key->cert->type != SSH2_CERT_TYPE_USER)
1322: continue;
1323: id = xcalloc(1, sizeof(*id));
1.230 djm 1324: id->agent_fd = -1;
1.227 djm 1325: id->key = key;
1326: id->filename = xstrdup(options.certificate_files[i]);
1327: id->userprovided = options.certificate_file_userprovided[i];
1328: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1329: }
1330: /* list of keys supported by the agent */
1.214 djm 1331: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1332: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1333: debug("%s: ssh_get_authentication_socket: %s",
1334: __func__, ssh_err(r));
1335: } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1336: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1337: debug("%s: ssh_fetch_identitylist: %s",
1338: __func__, ssh_err(r));
1.237 markus 1339: close(agent_fd);
1.214 djm 1340: } else {
1341: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1342: found = 0;
1343: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1344: /*
1345: * agent keys from the config file are
1346: * preferred
1347: */
1348: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1349: TAILQ_REMOVE(&files, id, next);
1350: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1351: id->agent_fd = agent_fd;
1.117 markus 1352: found = 1;
1353: break;
1354: }
1355: }
1.135 markus 1356: if (!found && !options.identities_only) {
1.150 djm 1357: id = xcalloc(1, sizeof(*id));
1.214 djm 1358: /* XXX "steals" key/comment from idlist */
1359: id->key = idlist->keys[j];
1360: id->filename = idlist->comments[j];
1361: idlist->keys[j] = NULL;
1362: idlist->comments[j] = NULL;
1363: id->agent_fd = agent_fd;
1.117 markus 1364: TAILQ_INSERT_TAIL(&agent, id, next);
1365: }
1366: }
1.214 djm 1367: ssh_free_identitylist(idlist);
1.117 markus 1368: /* append remaining agent keys */
1369: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1370: TAILQ_REMOVE(&agent, id, next);
1371: TAILQ_INSERT_TAIL(preferred, id, next);
1372: }
1.214 djm 1373: authctxt->agent_fd = agent_fd;
1.117 markus 1374: }
1375: /* append remaining keys from the config file */
1376: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1377: TAILQ_REMOVE(&files, id, next);
1378: TAILQ_INSERT_TAIL(preferred, id, next);
1379: }
1.228 djm 1380: /* finally, filter by PubkeyAcceptedKeyTypes */
1381: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1382: if (id->key != NULL &&
1383: match_pattern_list(sshkey_ssh_name(id->key),
1384: options.pubkey_key_types, 0) != 1) {
1385: debug("Skipping %s key %s - "
1386: "not in PubkeyAcceptedKeyTypes",
1387: sshkey_ssh_name(id->key), id->filename);
1388: TAILQ_REMOVE(preferred, id, next);
1389: sshkey_free(id->key);
1390: free(id->filename);
1391: memset(id, 0, sizeof(*id));
1392: continue;
1393: }
1.230 djm 1394: debug2("key: %s (%p)%s%s", id->filename, id->key,
1395: id->userprovided ? ", explicit" : "",
1396: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1397: }
1.17 markus 1398: }
1399:
1.117 markus 1400: static void
1401: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1402: {
1.117 markus 1403: Identity *id;
1.51 markus 1404:
1.214 djm 1405: if (authctxt->agent_fd != -1)
1406: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1407: for (id = TAILQ_FIRST(&authctxt->keys); id;
1408: id = TAILQ_FIRST(&authctxt->keys)) {
1409: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1410: sshkey_free(id->key);
1.197 djm 1411: free(id->filename);
1412: free(id);
1.117 markus 1413: }
1.1 markus 1414: }
1415:
1.225 markus 1416: static int
1417: try_identity(Identity *id)
1418: {
1419: if (!id->key)
1420: return (0);
1421: if (key_type_plain(id->key->type) == KEY_RSA &&
1422: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1423: debug("Skipped %s key %s for RSA/MD5 server",
1424: key_type(id->key), id->filename);
1425: return (0);
1426: }
1427: return (id->key->type != KEY_RSA1);
1428: }
1429:
1.20 markus 1430: int
1431: userauth_pubkey(Authctxt *authctxt)
1432: {
1.117 markus 1433: Identity *id;
1.20 markus 1434: int sent = 0;
1435:
1.117 markus 1436: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1437: if (id->tried++)
1438: return (0);
1.127 markus 1439: /* move key to the end of the queue */
1.117 markus 1440: TAILQ_REMOVE(&authctxt->keys, id, next);
1441: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1442: /*
1443: * send a test message if we have the public key. for
1444: * encrypted keys we cannot do this and have to load the
1445: * private key instead
1446: */
1.200 djm 1447: if (id->key != NULL) {
1.225 markus 1448: if (try_identity(id)) {
1.200 djm 1449: debug("Offering %s public key: %s",
1450: key_type(id->key), id->filename);
1451: sent = send_pubkey_test(authctxt, id);
1452: }
1453: } else {
1.117 markus 1454: debug("Trying private key: %s", id->filename);
1.229 jcs 1455: id->key = load_identity_file(id);
1.117 markus 1456: if (id->key != NULL) {
1.225 markus 1457: if (try_identity(id)) {
1458: id->isprivate = 1;
1.200 djm 1459: sent = sign_and_send_pubkey(
1460: authctxt, id);
1461: }
1.117 markus 1462: key_free(id->key);
1463: id->key = NULL;
1.51 markus 1464: }
1465: }
1.117 markus 1466: if (sent)
1467: return (sent);
1.28 markus 1468: }
1.117 markus 1469: return (0);
1.20 markus 1470: }
1471:
1.23 markus 1472: /*
1473: * Send userauth request message specifying keyboard-interactive method.
1474: */
1475: int
1476: userauth_kbdint(Authctxt *authctxt)
1477: {
1478: static int attempt = 0;
1479:
1480: if (attempt++ >= options.number_of_password_prompts)
1481: return 0;
1.82 markus 1482: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1483: if (attempt > 1 && !authctxt->info_req_seen) {
1484: debug3("userauth_kbdint: disable: no info_req_seen");
1485: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1486: return 0;
1487: }
1.23 markus 1488:
1489: debug2("userauth_kbdint");
1490: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1491: packet_put_cstring(authctxt->server_user);
1492: packet_put_cstring(authctxt->service);
1493: packet_put_cstring(authctxt->method->name);
1494: packet_put_cstring(""); /* lang */
1495: packet_put_cstring(options.kbd_interactive_devices ?
1496: options.kbd_interactive_devices : "");
1497: packet_send();
1498:
1499: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1500: return 1;
1501: }
1502:
1503: /*
1.46 markus 1504: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1505: */
1.218 markus 1506: int
1.92 markus 1507: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1508: {
1509: Authctxt *authctxt = ctxt;
1.46 markus 1510: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1511: u_int num_prompts, i;
1.23 markus 1512: int echo = 0;
1513:
1514: debug2("input_userauth_info_req");
1515:
1516: if (authctxt == NULL)
1517: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1518:
1519: authctxt->info_req_seen = 1;
1.23 markus 1520:
1521: name = packet_get_string(NULL);
1522: inst = packet_get_string(NULL);
1523: lang = packet_get_string(NULL);
1524: if (strlen(name) > 0)
1.116 itojun 1525: logit("%s", name);
1.23 markus 1526: if (strlen(inst) > 0)
1.116 itojun 1527: logit("%s", inst);
1.197 djm 1528: free(name);
1529: free(inst);
1530: free(lang);
1.23 markus 1531:
1532: num_prompts = packet_get_int();
1533: /*
1534: * Begin to build info response packet based on prompts requested.
1535: * We commit to providing the correct number of responses, so if
1536: * further on we run into a problem that prevents this, we have to
1537: * be sure and clean this up and send a correct error response.
1538: */
1539: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1540: packet_put_int(num_prompts);
1541:
1.73 markus 1542: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1543: for (i = 0; i < num_prompts; i++) {
1544: prompt = packet_get_string(NULL);
1545: echo = packet_get_char();
1546:
1.77 markus 1547: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1548:
1.49 markus 1549: packet_put_cstring(response);
1.204 djm 1550: explicit_bzero(response, strlen(response));
1.197 djm 1551: free(response);
1552: free(prompt);
1.23 markus 1553: }
1.90 markus 1554: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1555:
1.85 markus 1556: packet_add_padding(64);
1.23 markus 1557: packet_send();
1.218 markus 1558: return 0;
1.68 markus 1559: }
1560:
1.100 markus 1561: static int
1.223 djm 1562: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1563: const u_char *data, size_t datalen)
1.100 markus 1564: {
1.223 djm 1565: struct sshbuf *b;
1.101 markus 1566: struct stat st;
1.100 markus 1567: pid_t pid;
1.223 djm 1568: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1569: u_char rversion = 0, version = 2;
1570: void (*osigchld)(int);
1.100 markus 1571:
1.223 djm 1572: *sigp = NULL;
1573: *lenp = 0;
1.100 markus 1574:
1.101 markus 1575: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1576: error("%s: not installed: %s", __func__, strerror(errno));
1577: return -1;
1578: }
1579: if (fflush(stdout) != 0) {
1580: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1581: return -1;
1582: }
1.100 markus 1583: if (pipe(to) < 0) {
1.223 djm 1584: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1585: return -1;
1586: }
1587: if (pipe(from) < 0) {
1.223 djm 1588: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1589: return -1;
1590: }
1591: if ((pid = fork()) < 0) {
1.223 djm 1592: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1593: return -1;
1594: }
1.223 djm 1595: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1596: if (pid == 0) {
1.174 dtucker 1597: /* keep the socket on exec */
1.223 djm 1598: fcntl(sock, F_SETFD, 0);
1.155 markus 1599: permanently_drop_suid(getuid());
1.100 markus 1600: close(from[0]);
1601: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1602: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1603: close(to[1]);
1604: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1605: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1606: close(from[1]);
1607: close(to[0]);
1.223 djm 1608: /* Close everything but stdio and the socket */
1609: for (i = STDERR_FILENO + 1; i < sock; i++)
1610: close(i);
1611: closefrom(sock + 1);
1612: debug3("%s: [child] pid=%ld, exec %s",
1613: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1614: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1615: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1616: strerror(errno));
1617: }
1618: close(from[1]);
1619: close(to[0]);
1620:
1.223 djm 1621: if ((b = sshbuf_new()) == NULL)
1622: fatal("%s: sshbuf_new failed", __func__);
1623: /* send # of sock, data to be signed */
1624: if ((r = sshbuf_put_u32(b, sock) != 0) ||
1625: (r = sshbuf_put_string(b, data, datalen)) != 0)
1626: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1627: if (ssh_msg_send(to[1], version, b) == -1)
1628: fatal("%s: couldn't send request", __func__);
1629: sshbuf_reset(b);
1630: r = ssh_msg_recv(from[0], b);
1.101 markus 1631: close(from[0]);
1632: close(to[1]);
1.223 djm 1633: if (r < 0) {
1634: error("%s: no reply", __func__);
1635: goto fail;
1636: }
1.101 markus 1637:
1.223 djm 1638: errno = 0;
1639: while (waitpid(pid, &status, 0) < 0) {
1640: if (errno != EINTR) {
1641: error("%s: waitpid %ld: %s",
1642: __func__, (long)pid, strerror(errno));
1643: goto fail;
1644: }
1645: }
1646: if (!WIFEXITED(status)) {
1647: error("%s: exited abnormally", __func__);
1648: goto fail;
1649: }
1650: if (WEXITSTATUS(status) != 0) {
1651: error("%s: exited with status %d",
1652: __func__, WEXITSTATUS(status));
1653: goto fail;
1654: }
1655: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1656: error("%s: buffer error: %s", __func__, ssh_err(r));
1657: goto fail;
1658: }
1659: if (rversion != version) {
1660: error("%s: bad version", __func__);
1661: goto fail;
1662: }
1663: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1664: error("%s: buffer error: %s", __func__, ssh_err(r));
1665: fail:
1666: signal(SIGCHLD, osigchld);
1667: sshbuf_free(b);
1.100 markus 1668: return -1;
1669: }
1.223 djm 1670: signal(SIGCHLD, osigchld);
1671: sshbuf_free(b);
1.100 markus 1672:
1673: return 0;
1674: }
1675:
1.68 markus 1676: int
1677: userauth_hostbased(Authctxt *authctxt)
1678: {
1.223 djm 1679: struct ssh *ssh = active_state;
1680: struct sshkey *private = NULL;
1681: struct sshbuf *b = NULL;
1.72 markus 1682: const char *service;
1.223 djm 1683: u_char *sig = NULL, *keyblob = NULL;
1684: char *fp = NULL, *chost = NULL, *lname = NULL;
1685: size_t siglen = 0, keylen = 0;
1686: int i, r, success = 0;
1687:
1688: if (authctxt->ktypes == NULL) {
1689: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1690: authctxt->ktypes = authctxt->oktypes;
1691: }
1.213 djm 1692:
1.223 djm 1693: /*
1694: * Work through each listed type pattern in HostbasedKeyTypes,
1695: * trying each hostkey that matches the type in turn.
1696: */
1697: for (;;) {
1698: if (authctxt->active_ktype == NULL)
1699: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1700: if (authctxt->active_ktype == NULL ||
1701: *authctxt->active_ktype == '\0')
1702: break;
1703: debug3("%s: trying key type %s", __func__,
1704: authctxt->active_ktype);
1.68 markus 1705:
1.223 djm 1706: /* check for a useful key */
1707: private = NULL;
1708: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1709: if (authctxt->sensitive->keys[i] == NULL ||
1710: authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
1711: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1712: continue;
1713: if (match_pattern_list(
1714: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1715: authctxt->active_ktype, 0) != 1)
1.223 djm 1716: continue;
1.68 markus 1717: /* we take and free the key */
1.223 djm 1718: private = authctxt->sensitive->keys[i];
1719: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1720: break;
1721: }
1.223 djm 1722: /* Found one */
1723: if (private != NULL)
1724: break;
1725: /* No more keys of this type; advance */
1726: authctxt->active_ktype = NULL;
1.68 markus 1727: }
1.223 djm 1728: if (private == NULL) {
1729: free(authctxt->oktypes);
1730: authctxt->oktypes = authctxt->ktypes = NULL;
1731: authctxt->active_ktype = NULL;
1.109 markus 1732: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1733: goto out;
1.68 markus 1734: }
1.211 djm 1735:
1.223 djm 1736: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1737: SSH_FP_DEFAULT)) == NULL) {
1738: error("%s: sshkey_fingerprint failed", __func__);
1739: goto out;
1.68 markus 1740: }
1.223 djm 1741: debug("%s: trying hostkey %s %s",
1742: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1743:
1.84 markus 1744: /* figure out a name for the client host */
1.223 djm 1745: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1746: error("%s: cannot get local ipaddr/name", __func__);
1747: goto out;
1.84 markus 1748: }
1.223 djm 1749:
1750: /* XXX sshbuf_put_stringf? */
1751: xasprintf(&chost, "%s.", lname);
1752: debug2("%s: chost %s", __func__, chost);
1.84 markus 1753:
1.72 markus 1754: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1755: authctxt->service;
1.223 djm 1756:
1.68 markus 1757: /* construct data */
1.223 djm 1758: if ((b = sshbuf_new()) == NULL) {
1759: error("%s: sshbuf_new failed", __func__);
1760: goto out;
1761: }
1762: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1763: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1764: goto out;
1765: }
1766: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1767: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1768: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1769: (r = sshbuf_put_cstring(b, service)) != 0 ||
1770: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1771: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1772: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1773: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1774: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1775: error("%s: buffer error: %s", __func__, ssh_err(r));
1776: goto out;
1777: }
1778:
1.68 markus 1779: #ifdef DEBUG_PK
1.223 djm 1780: sshbuf_dump(b, stderr);
1.68 markus 1781: #endif
1.223 djm 1782: if (authctxt->sensitive->external_keysign)
1783: r = ssh_keysign(private, &sig, &siglen,
1784: sshbuf_ptr(b), sshbuf_len(b));
1785: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1786: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1787: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1788: if (r != 0) {
1789: error("sign using hostkey %s %s failed",
1790: sshkey_ssh_name(private), fp);
1791: goto out;
1792: }
1793: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1794: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1795: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1796: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1797: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1798: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1799: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1800: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1801: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1802: (r = sshpkt_send(ssh)) != 0) {
1803: error("%s: packet error: %s", __func__, ssh_err(r));
1804: goto out;
1805: }
1806: success = 1;
1807:
1808: out:
1809: if (sig != NULL) {
1810: explicit_bzero(sig, siglen);
1811: free(sig);
1.68 markus 1812: }
1.223 djm 1813: free(keyblob);
1814: free(lname);
1815: free(fp);
1.197 djm 1816: free(chost);
1.223 djm 1817: sshkey_free(private);
1818: sshbuf_free(b);
1.68 markus 1819:
1.223 djm 1820: return success;
1.23 markus 1821: }
1.170 djm 1822:
1.20 markus 1823: /* find auth method */
1824:
1825: /*
1826: * given auth method name, if configurable options permit this method fill
1827: * in auth_ident field and return true, otherwise return false.
1828: */
1.76 itojun 1829: static int
1.20 markus 1830: authmethod_is_enabled(Authmethod *method)
1831: {
1832: if (method == NULL)
1833: return 0;
1834: /* return false if options indicate this method is disabled */
1835: if (method->enabled == NULL || *method->enabled == 0)
1836: return 0;
1837: /* return false if batch mode is enabled but method needs interactive mode */
1838: if (method->batch_flag != NULL && *method->batch_flag != 0)
1839: return 0;
1840: return 1;
1841: }
1842:
1.76 itojun 1843: static Authmethod *
1.20 markus 1844: authmethod_lookup(const char *name)
1.1 markus 1845: {
1.20 markus 1846: Authmethod *method = NULL;
1847: if (name != NULL)
1848: for (method = authmethods; method->name != NULL; method++)
1849: if (strcmp(name, method->name) == 0)
1850: return method;
1851: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1852: return NULL;
1853: }
1.1 markus 1854:
1.53 markus 1855: /* XXX internal state */
1856: static Authmethod *current = NULL;
1857: static char *supported = NULL;
1858: static char *preferred = NULL;
1.105 deraadt 1859:
1.20 markus 1860: /*
1861: * Given the authentication method list sent by the server, return the
1862: * next method we should try. If the server initially sends a nil list,
1.67 markus 1863: * use a built-in default list.
1.41 stevesk 1864: */
1.76 itojun 1865: static Authmethod *
1.20 markus 1866: authmethod_get(char *authlist)
1867: {
1.53 markus 1868: char *name = NULL;
1.97 markus 1869: u_int next;
1.41 stevesk 1870:
1.20 markus 1871: /* Use a suitable default if we're passed a nil list. */
1872: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1873: authlist = options.preferred_authentications;
1.20 markus 1874:
1.53 markus 1875: if (supported == NULL || strcmp(authlist, supported) != 0) {
1876: debug3("start over, passed a different list %s", authlist);
1.197 djm 1877: free(supported);
1.53 markus 1878: supported = xstrdup(authlist);
1879: preferred = options.preferred_authentications;
1880: debug3("preferred %s", preferred);
1881: current = NULL;
1882: } else if (current != NULL && authmethod_is_enabled(current))
1883: return current;
1.20 markus 1884:
1.53 markus 1885: for (;;) {
1886: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1887: debug("No more authentication methods to try.");
1.53 markus 1888: current = NULL;
1889: return NULL;
1890: }
1891: preferred += next;
1.23 markus 1892: debug3("authmethod_lookup %s", name);
1.53 markus 1893: debug3("remaining preferred: %s", preferred);
1894: if ((current = authmethod_lookup(name)) != NULL &&
1895: authmethod_is_enabled(current)) {
1.23 markus 1896: debug3("authmethod_is_enabled %s", name);
1.109 markus 1897: debug("Next authentication method: %s", name);
1.197 djm 1898: free(name);
1.53 markus 1899: return current;
1.23 markus 1900: }
1.198 dtucker 1901: free(name);
1.1 markus 1902: }
1.53 markus 1903: }
1.1 markus 1904:
1.79 stevesk 1905: static char *
1.53 markus 1906: authmethods_get(void)
1907: {
1908: Authmethod *method = NULL;
1.93 markus 1909: Buffer b;
1910: char *list;
1.27 provos 1911:
1.93 markus 1912: buffer_init(&b);
1.53 markus 1913: for (method = authmethods; method->name != NULL; method++) {
1914: if (authmethod_is_enabled(method)) {
1.93 markus 1915: if (buffer_len(&b) > 0)
1916: buffer_append(&b, ",", 1);
1917: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1918: }
1919: }
1.242 djm 1920: if ((list = sshbuf_dup_string(&b)) == NULL)
1921: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1922: buffer_free(&b);
1923: return list;
1.1 markus 1924: }
1.170 djm 1925:
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