Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.245
1.245 ! dtucker 1: /* $OpenBSD: sshconnect2.c,v 1.244 2016/05/23 23:30:50 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);
1.245 ! dtucker 168: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
! 169: myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ?
! 170: "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib";
1.226 djm 171: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
172: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
173: if (options.hostkeyalgorithms != NULL) {
174: if (kex_assemble_names(KEX_DEFAULT_PK_ALG,
175: &options.hostkeyalgorithms) != 0)
176: fatal("%s: kex_assemble_namelist", __func__);
1.88 deraadt 177: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 178: compat_pkalg_proposal(options.hostkeyalgorithms);
1.226 djm 179: } else {
1.225 markus 180: /* Enforce default */
181: options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
1.186 djm 182: /* Prefer algorithms that we already have keys for */
183: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 184: compat_pkalg_proposal(
185: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 186: }
1.115 markus 187:
1.196 dtucker 188: if (options.rekey_limit || options.rekey_interval)
189: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
190: (time_t)options.rekey_interval);
1.22 provos 191:
1.65 markus 192: /* start key exchange */
1.221 markus 193: if ((r = kex_setup(active_state, myproposal)) != 0)
194: fatal("kex_setup: %s", ssh_err(r));
1.219 markus 195: kex = active_state->kex;
1.207 markus 196: #ifdef WITH_OPENSSL
1.111 markus 197: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 198: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.243 djm 199: kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
200: kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
201: kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client;
1.111 markus 202: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 203: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 204: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.207 markus 205: #endif
1.199 markus 206: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 207: kex->client_version_string=client_version_string;
208: kex->server_version_string=server_version_string;
1.75 markus 209: kex->verify_host_key=&verify_host_key_callback;
1.22 provos 210:
1.219 markus 211: dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
1.173 andreas 212:
1.231 markus 213: /* remove ext-info from the KEX proposals for rekeying */
214: myproposal[PROPOSAL_KEX_ALGS] =
215: compat_kex_proposal(options.kex_algorithms);
216: if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
217: fatal("kex_prop2buf: %s", ssh_err(r));
1.62 markus 218:
219: session_id2 = kex->session_id;
220: session_id2_len = kex->session_id_len;
1.22 provos 221:
222: #ifdef DEBUG_KEXDH
223: /* send 1st encrypted/maced/compressed message */
224: packet_start(SSH2_MSG_IGNORE);
225: packet_put_cstring("markus");
226: packet_send();
227: packet_write_wait();
228: #endif
1.1 markus 229: }
1.11 markus 230:
1.1 markus 231: /*
232: * Authenticate user
233: */
1.20 markus 234:
1.214 djm 235: typedef struct cauthctxt Authctxt;
236: typedef struct cauthmethod Authmethod;
1.117 markus 237: typedef struct identity Identity;
238: typedef struct idlist Idlist;
1.20 markus 239:
1.117 markus 240: struct identity {
241: TAILQ_ENTRY(identity) next;
1.214 djm 242: int agent_fd; /* >=0 if agent supports key */
243: struct sshkey *key; /* public/private key */
1.117 markus 244: char *filename; /* comment for agent-only keys */
245: int tried;
246: int isprivate; /* key points to the private key */
1.191 dtucker 247: int userprovided;
1.117 markus 248: };
249: TAILQ_HEAD(idlist, identity);
1.20 markus 250:
1.214 djm 251: struct cauthctxt {
1.20 markus 252: const char *server_user;
1.68 markus 253: const char *local_user;
1.20 markus 254: const char *host;
255: const char *service;
1.214 djm 256: struct cauthmethod *method;
1.183 djm 257: sig_atomic_t success;
1.51 markus 258: char *authlist;
1.214 djm 259: int attempt;
1.68 markus 260: /* pubkey */
1.214 djm 261: struct idlist keys;
262: int agent_fd;
1.68 markus 263: /* hostbased */
1.100 markus 264: Sensitive *sensitive;
1.223 djm 265: char *oktypes, *ktypes;
266: const char *active_ktype;
1.82 markus 267: /* kbd-interactive */
268: int info_req_seen;
1.121 markus 269: /* generic */
270: void *methoddata;
1.20 markus 271: };
1.214 djm 272:
273: struct cauthmethod {
1.20 markus 274: char *name; /* string to compare against server's list */
275: int (*userauth)(Authctxt *authctxt);
1.170 djm 276: void (*cleanup)(Authctxt *authctxt);
1.20 markus 277: int *enabled; /* flag in option struct that enables method */
278: int *batch_flag; /* flag in option struct that disables method */
279: };
280:
1.231 markus 281: int input_userauth_service_accept(int, u_int32_t, void *);
282: int input_userauth_ext_info(int, u_int32_t, void *);
1.218 markus 283: int input_userauth_success(int, u_int32_t, void *);
284: int input_userauth_success_unexpected(int, u_int32_t, void *);
285: int input_userauth_failure(int, u_int32_t, void *);
286: int input_userauth_banner(int, u_int32_t, void *);
287: int input_userauth_error(int, u_int32_t, void *);
288: int input_userauth_info_req(int, u_int32_t, void *);
289: int input_userauth_pk_ok(int, u_int32_t, void *);
290: int input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 291:
292: int userauth_none(Authctxt *);
293: int userauth_pubkey(Authctxt *);
294: int userauth_passwd(Authctxt *);
295: int userauth_kbdint(Authctxt *);
296: int userauth_hostbased(Authctxt *);
1.20 markus 297:
1.121 markus 298: #ifdef GSSAPI
299: int userauth_gssapi(Authctxt *authctxt);
1.218 markus 300: int input_gssapi_response(int type, u_int32_t, void *);
301: int input_gssapi_token(int type, u_int32_t, void *);
302: int input_gssapi_hash(int type, u_int32_t, void *);
303: int input_gssapi_error(int, u_int32_t, void *);
304: int input_gssapi_errtok(int, u_int32_t, void *);
1.121 markus 305: #endif
306:
1.86 itojun 307: void userauth(Authctxt *, char *);
1.51 markus 308:
1.117 markus 309: static int sign_and_send_pubkey(Authctxt *, Identity *);
310: static void pubkey_prepare(Authctxt *);
311: static void pubkey_cleanup(Authctxt *);
1.229 jcs 312: static Key *load_identity_file(Identity *);
1.76 itojun 313:
314: static Authmethod *authmethod_get(char *authlist);
315: static Authmethod *authmethod_lookup(const char *name);
316: static char *authmethods_get(void);
1.20 markus 317:
318: Authmethod authmethods[] = {
1.121 markus 319: #ifdef GSSAPI
1.132 markus 320: {"gssapi-with-mic",
1.121 markus 321: userauth_gssapi,
1.170 djm 322: NULL,
1.121 markus 323: &options.gss_authentication,
324: NULL},
325: #endif
1.81 markus 326: {"hostbased",
327: userauth_hostbased,
1.170 djm 328: NULL,
1.81 markus 329: &options.hostbased_authentication,
330: NULL},
1.20 markus 331: {"publickey",
332: userauth_pubkey,
1.170 djm 333: NULL,
1.28 markus 334: &options.pubkey_authentication,
1.20 markus 335: NULL},
1.81 markus 336: {"keyboard-interactive",
337: userauth_kbdint,
1.170 djm 338: NULL,
1.81 markus 339: &options.kbd_interactive_authentication,
340: &options.batch_mode},
1.20 markus 341: {"password",
342: userauth_passwd,
1.170 djm 343: NULL,
1.20 markus 344: &options.password_authentication,
1.23 markus 345: &options.batch_mode},
346: {"none",
347: userauth_none,
348: NULL,
1.170 djm 349: NULL,
1.23 markus 350: NULL},
1.170 djm 351: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 352: };
353:
354: void
1.68 markus 355: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 356: Sensitive *sensitive)
1.20 markus 357: {
1.231 markus 358: struct ssh *ssh = active_state;
1.20 markus 359: Authctxt authctxt;
1.231 markus 360: int r;
1.39 markus 361:
1.73 markus 362: if (options.challenge_response_authentication)
1.39 markus 363: options.kbd_interactive_authentication = 1;
1.53 markus 364: if (options.preferred_authentications == NULL)
365: options.preferred_authentications = authmethods_get();
366:
1.20 markus 367: /* setup authentication context */
1.82 markus 368: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 369: pubkey_prepare(&authctxt);
1.20 markus 370: authctxt.server_user = server_user;
1.68 markus 371: authctxt.local_user = local_user;
1.20 markus 372: authctxt.host = host;
373: authctxt.service = "ssh-connection"; /* service name */
374: authctxt.success = 0;
1.23 markus 375: authctxt.method = authmethod_lookup("none");
1.51 markus 376: authctxt.authlist = NULL;
1.121 markus 377: authctxt.methoddata = NULL;
1.100 markus 378: authctxt.sensitive = sensitive;
1.223 djm 379: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 380: authctxt.info_req_seen = 0;
1.215 djm 381: authctxt.agent_fd = -1;
1.23 markus 382: if (authctxt.method == NULL)
383: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 384:
1.231 markus 385: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
386: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
387: (r = sshpkt_send(ssh)) != 0)
388: fatal("%s: %s", __func__, ssh_err(r));
389:
390: ssh_dispatch_init(ssh, &input_userauth_error);
391: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
392: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
393: ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
1.20 markus 394:
1.117 markus 395: pubkey_cleanup(&authctxt);
1.231 markus 396: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 397:
1.109 markus 398: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 399: }
1.119 markus 400:
1.231 markus 401: /* ARGSUSED */
402: int
403: input_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt)
404: {
405: Authctxt *authctxt = ctxt;
406: struct ssh *ssh = active_state;
407: int r;
408:
409: if (ssh_packet_remaining(ssh) > 0) {
410: char *reply;
411:
412: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
413: goto out;
414: debug2("service_accept: %s", reply);
415: free(reply);
416: } else {
417: debug2("buggy server: service_accept w/o service");
418: }
419: if ((r = sshpkt_get_end(ssh)) != 0)
420: goto out;
421: debug("SSH2_MSG_SERVICE_ACCEPT received");
422:
423: /* initial userauth request */
424: userauth_none(authctxt);
425:
426: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
427: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
428: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
429: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
430: r = 0;
431: out:
432: return r;
433: }
434:
435: /* ARGSUSED */
436: int
437: input_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt)
438: {
439: return kex_input_ext_info(type, seqnr, active_state);
440: }
441:
1.20 markus 442: void
1.51 markus 443: userauth(Authctxt *authctxt, char *authlist)
444: {
1.170 djm 445: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
446: authctxt->method->cleanup(authctxt);
447:
1.197 djm 448: free(authctxt->methoddata);
449: authctxt->methoddata = NULL;
1.51 markus 450: if (authlist == NULL) {
451: authlist = authctxt->authlist;
452: } else {
1.197 djm 453: free(authctxt->authlist);
1.51 markus 454: authctxt->authlist = authlist;
455: }
456: for (;;) {
457: Authmethod *method = authmethod_get(authlist);
458: if (method == NULL)
459: fatal("Permission denied (%s).", authlist);
460: authctxt->method = method;
1.119 markus 461:
462: /* reset the per method handler */
463: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
464: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
465:
466: /* and try new method */
1.51 markus 467: if (method->userauth(authctxt) != 0) {
468: debug2("we sent a %s packet, wait for reply", method->name);
469: break;
470: } else {
471: debug2("we did not send a packet, disable method");
472: method->enabled = NULL;
473: }
474: }
475: }
1.105 deraadt 476:
1.169 djm 477: /* ARGSUSED */
1.218 markus 478: int
1.92 markus 479: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 480: {
1.35 markus 481: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 482: "type %d", type);
1.218 markus 483: return 0;
1.35 markus 484: }
1.105 deraadt 485:
1.169 djm 486: /* ARGSUSED */
1.218 markus 487: int
1.92 markus 488: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 489: {
1.166 djm 490: char *msg, *raw, *lang;
491: u_int len;
1.126 deraadt 492:
1.35 markus 493: debug3("input_userauth_banner");
1.166 djm 494: raw = packet_get_string(&len);
1.35 markus 495: lang = packet_get_string(NULL);
1.167 markus 496: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 497: if (len > 65536)
498: len = 65536;
1.168 deraadt 499: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 500: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 501: fprintf(stderr, "%s", msg);
1.197 djm 502: free(msg);
1.166 djm 503: }
1.197 djm 504: free(raw);
505: free(lang);
1.218 markus 506: return 0;
1.20 markus 507: }
1.105 deraadt 508:
1.169 djm 509: /* ARGSUSED */
1.218 markus 510: int
1.92 markus 511: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 512: {
513: Authctxt *authctxt = ctxt;
1.172 djm 514:
1.20 markus 515: if (authctxt == NULL)
516: fatal("input_userauth_success: no authentication context");
1.197 djm 517: free(authctxt->authlist);
518: authctxt->authlist = NULL;
1.172 djm 519: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
520: authctxt->method->cleanup(authctxt);
1.197 djm 521: free(authctxt->methoddata);
522: authctxt->methoddata = NULL;
1.20 markus 523: authctxt->success = 1; /* break out */
1.218 markus 524: return 0;
1.20 markus 525: }
1.105 deraadt 526:
1.218 markus 527: int
1.172 djm 528: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
529: {
530: Authctxt *authctxt = ctxt;
531:
532: if (authctxt == NULL)
533: fatal("%s: no authentication context", __func__);
534:
535: fatal("Unexpected authentication success during %s.",
536: authctxt->method->name);
1.218 markus 537: return 0;
1.172 djm 538: }
539:
1.169 djm 540: /* ARGSUSED */
1.218 markus 541: int
1.92 markus 542: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 543: {
544: Authctxt *authctxt = ctxt;
545: char *authlist = NULL;
546: int partial;
547:
548: if (authctxt == NULL)
549: fatal("input_userauth_failure: no authentication context");
550:
1.23 markus 551: authlist = packet_get_string(NULL);
1.20 markus 552: partial = packet_get_char();
1.90 markus 553: packet_check_eom();
1.20 markus 554:
1.193 markus 555: if (partial != 0) {
1.116 itojun 556: logit("Authenticated with partial success.");
1.193 markus 557: /* reset state */
558: pubkey_cleanup(authctxt);
559: pubkey_prepare(authctxt);
560: }
1.109 markus 561: debug("Authentications that can continue: %s", authlist);
1.20 markus 562:
1.51 markus 563: userauth(authctxt, authlist);
1.218 markus 564: return 0;
1.51 markus 565: }
1.169 djm 566:
567: /* ARGSUSED */
1.218 markus 568: int
1.92 markus 569: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 570: {
571: Authctxt *authctxt = ctxt;
572: Key *key = NULL;
1.117 markus 573: Identity *id = NULL;
1.51 markus 574: Buffer b;
1.96 markus 575: int pktype, sent = 0;
576: u_int alen, blen;
577: char *pkalg, *fp;
578: u_char *pkblob;
1.51 markus 579:
580: if (authctxt == NULL)
581: fatal("input_userauth_pk_ok: no authentication context");
582: if (datafellows & SSH_BUG_PKOK) {
583: /* this is similar to SSH_BUG_PKAUTH */
584: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
585: pkblob = packet_get_string(&blen);
586: buffer_init(&b);
587: buffer_append(&b, pkblob, blen);
588: pkalg = buffer_get_string(&b, &alen);
589: buffer_free(&b);
590: } else {
591: pkalg = packet_get_string(&alen);
592: pkblob = packet_get_string(&blen);
593: }
1.90 markus 594: packet_check_eom();
1.51 markus 595:
1.117 markus 596: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 597:
1.117 markus 598: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
599: debug("unknown pkalg %s", pkalg);
600: goto done;
601: }
602: if ((key = key_from_blob(pkblob, blen)) == NULL) {
603: debug("no key from blob. pkalg %s", pkalg);
604: goto done;
605: }
606: if (key->type != pktype) {
607: error("input_userauth_pk_ok: type mismatch "
608: "for decoded key (received %d, expected %d)",
609: key->type, pktype);
610: goto done;
611: }
1.222 djm 612: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
613: SSH_FP_DEFAULT)) == NULL)
614: goto done;
1.117 markus 615: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 616: free(fp);
1.117 markus 617:
1.127 markus 618: /*
619: * search keys in the reverse order, because last candidate has been
620: * moved to the end of the queue. this also avoids confusion by
621: * duplicate keys
622: */
1.136 henning 623: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 624: if (key_equal(key, id->key)) {
625: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 626: break;
627: }
1.117 markus 628: }
629: done:
1.51 markus 630: if (key != NULL)
631: key_free(key);
1.197 djm 632: free(pkalg);
633: free(pkblob);
1.51 markus 634:
1.106 deraadt 635: /* try another method if we did not send a packet */
1.51 markus 636: if (sent == 0)
637: userauth(authctxt, NULL);
1.218 markus 638: return 0;
1.20 markus 639: }
1.121 markus 640:
641: #ifdef GSSAPI
1.133 djm 642: int
1.121 markus 643: userauth_gssapi(Authctxt *authctxt)
644: {
645: Gssctxt *gssctxt = NULL;
1.128 avsm 646: static gss_OID_set gss_supported = NULL;
1.139 djm 647: static u_int mech = 0;
1.121 markus 648: OM_uint32 min;
649: int ok = 0;
650:
651: /* Try one GSSAPI method at a time, rather than sending them all at
652: * once. */
653:
1.128 avsm 654: if (gss_supported == NULL)
655: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 656:
657: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 658: while (mech < gss_supported->count && !ok) {
1.121 markus 659: /* My DER encoding requires length<128 */
1.128 avsm 660: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 661: ssh_gssapi_check_mechanism(&gssctxt,
662: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 663: ok = 1; /* Mechanism works */
664: } else {
665: mech++;
666: }
667: }
668:
1.161 djm 669: if (!ok)
1.139 djm 670: return 0;
1.121 markus 671:
672: authctxt->methoddata=(void *)gssctxt;
673:
674: packet_start(SSH2_MSG_USERAUTH_REQUEST);
675: packet_put_cstring(authctxt->server_user);
676: packet_put_cstring(authctxt->service);
677: packet_put_cstring(authctxt->method->name);
678:
679: packet_put_int(1);
680:
1.129 markus 681: packet_put_int((gss_supported->elements[mech].length) + 2);
682: packet_put_char(SSH_GSS_OIDTYPE);
683: packet_put_char(gss_supported->elements[mech].length);
684: packet_put_raw(gss_supported->elements[mech].elements,
685: gss_supported->elements[mech].length);
1.121 markus 686:
687: packet_send();
688:
689: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
690: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
691: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
692: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
693:
694: mech++; /* Move along to next candidate */
695:
696: return 1;
697: }
698:
1.130 markus 699: static OM_uint32
700: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
701: {
702: Authctxt *authctxt = ctxt;
703: Gssctxt *gssctxt = authctxt->methoddata;
704: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 705: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
706: gss_buffer_desc gssbuf;
1.132 markus 707: OM_uint32 status, ms, flags;
708: Buffer b;
1.133 djm 709:
1.130 markus 710: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 711: recv_tok, &send_tok, &flags);
1.130 markus 712:
713: if (send_tok.length > 0) {
714: if (GSS_ERROR(status))
715: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
716: else
717: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 718:
1.130 markus 719: packet_put_string(send_tok.value, send_tok.length);
720: packet_send();
721: gss_release_buffer(&ms, &send_tok);
722: }
1.133 djm 723:
1.130 markus 724: if (status == GSS_S_COMPLETE) {
1.132 markus 725: /* send either complete or MIC, depending on mechanism */
726: if (!(flags & GSS_C_INTEG_FLAG)) {
727: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
728: packet_send();
729: } else {
730: ssh_gssapi_buildmic(&b, authctxt->server_user,
731: authctxt->service, "gssapi-with-mic");
732:
733: gssbuf.value = buffer_ptr(&b);
734: gssbuf.length = buffer_len(&b);
1.133 djm 735:
1.132 markus 736: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 737:
1.132 markus 738: if (!GSS_ERROR(status)) {
739: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
740: packet_put_string(mic.value, mic.length);
1.133 djm 741:
1.132 markus 742: packet_send();
743: }
1.133 djm 744:
1.132 markus 745: buffer_free(&b);
746: gss_release_buffer(&ms, &mic);
1.133 djm 747: }
1.130 markus 748: }
1.133 djm 749:
1.130 markus 750: return status;
751: }
752:
1.169 djm 753: /* ARGSUSED */
1.220 djm 754: int
1.121 markus 755: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
756: {
757: Authctxt *authctxt = ctxt;
758: Gssctxt *gssctxt;
759: int oidlen;
760: char *oidv;
761:
762: if (authctxt == NULL)
763: fatal("input_gssapi_response: no authentication context");
764: gssctxt = authctxt->methoddata;
765:
766: /* Setup our OID */
767: oidv = packet_get_string(&oidlen);
768:
1.129 markus 769: if (oidlen <= 2 ||
770: oidv[0] != SSH_GSS_OIDTYPE ||
771: oidv[1] != oidlen - 2) {
1.197 djm 772: free(oidv);
1.129 markus 773: debug("Badly encoded mechanism OID received");
774: userauth(authctxt, NULL);
1.220 djm 775: return 0;
1.121 markus 776: }
1.129 markus 777:
778: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
779: fatal("Server returned different OID than expected");
1.121 markus 780:
781: packet_check_eom();
782:
1.197 djm 783: free(oidv);
1.121 markus 784:
1.130 markus 785: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 786: /* Start again with next method on list */
787: debug("Trying to start again");
788: userauth(authctxt, NULL);
1.220 djm 789: return 0;
1.121 markus 790: }
1.220 djm 791: return 0;
1.121 markus 792: }
793:
1.169 djm 794: /* ARGSUSED */
1.220 djm 795: int
1.121 markus 796: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
797: {
798: Authctxt *authctxt = ctxt;
799: gss_buffer_desc recv_tok;
1.130 markus 800: OM_uint32 status;
1.121 markus 801: u_int slen;
802:
803: if (authctxt == NULL)
804: fatal("input_gssapi_response: no authentication context");
805:
806: recv_tok.value = packet_get_string(&slen);
807: recv_tok.length = slen; /* safe typecast */
808:
809: packet_check_eom();
810:
1.130 markus 811: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 812:
1.197 djm 813: free(recv_tok.value);
1.121 markus 814:
815: if (GSS_ERROR(status)) {
816: /* Start again with the next method in the list */
817: userauth(authctxt, NULL);
1.220 djm 818: return 0;
1.121 markus 819: }
1.220 djm 820: return 0;
1.121 markus 821: }
822:
1.169 djm 823: /* ARGSUSED */
1.220 djm 824: int
1.121 markus 825: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
826: {
827: Authctxt *authctxt = ctxt;
828: Gssctxt *gssctxt;
829: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
830: gss_buffer_desc recv_tok;
1.194 djm 831: OM_uint32 ms;
1.123 deraadt 832: u_int len;
1.121 markus 833:
834: if (authctxt == NULL)
835: fatal("input_gssapi_response: no authentication context");
836: gssctxt = authctxt->methoddata;
837:
1.123 deraadt 838: recv_tok.value = packet_get_string(&len);
839: recv_tok.length = len;
1.121 markus 840:
841: packet_check_eom();
842:
843: /* Stick it into GSSAPI and see what it says */
1.194 djm 844: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 845: &recv_tok, &send_tok, NULL);
1.121 markus 846:
1.197 djm 847: free(recv_tok.value);
1.121 markus 848: gss_release_buffer(&ms, &send_tok);
849:
850: /* Server will be returning a failed packet after this one */
1.220 djm 851: return 0;
1.121 markus 852: }
853:
1.169 djm 854: /* ARGSUSED */
1.220 djm 855: int
1.121 markus 856: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
857: {
858: char *msg;
859: char *lang;
860:
1.194 djm 861: /* maj */(void)packet_get_int();
862: /* min */(void)packet_get_int();
1.121 markus 863: msg=packet_get_string(NULL);
864: lang=packet_get_string(NULL);
865:
866: packet_check_eom();
867:
1.143 stevesk 868: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 869: free(msg);
870: free(lang);
1.220 djm 871: return 0;
1.121 markus 872: }
873: #endif /* GSSAPI */
1.20 markus 874:
1.1 markus 875: int
1.23 markus 876: userauth_none(Authctxt *authctxt)
877: {
878: /* initial userauth request */
879: packet_start(SSH2_MSG_USERAUTH_REQUEST);
880: packet_put_cstring(authctxt->server_user);
881: packet_put_cstring(authctxt->service);
882: packet_put_cstring(authctxt->method->name);
883: packet_send();
884: return 1;
885: }
886:
887: int
1.20 markus 888: userauth_passwd(Authctxt *authctxt)
1.1 markus 889: {
1.6 markus 890: static int attempt = 0;
1.99 markus 891: char prompt[150];
1.1 markus 892: char *password;
1.175 dtucker 893: const char *host = options.host_key_alias ? options.host_key_alias :
894: authctxt->host;
1.6 markus 895:
1.13 todd 896: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 897: return 0;
1.13 todd 898:
1.87 deraadt 899: if (attempt != 1)
1.13 todd 900: error("Permission denied, please try again.");
1.1 markus 901:
1.43 itojun 902: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 903: authctxt->server_user, host);
1.1 markus 904: password = read_passphrase(prompt, 0);
905: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 906: packet_put_cstring(authctxt->server_user);
907: packet_put_cstring(authctxt->service);
1.23 markus 908: packet_put_cstring(authctxt->method->name);
1.1 markus 909: packet_put_char(0);
1.49 markus 910: packet_put_cstring(password);
1.204 djm 911: explicit_bzero(password, strlen(password));
1.197 djm 912: free(password);
1.85 markus 913: packet_add_padding(64);
1.1 markus 914: packet_send();
1.99 markus 915:
1.104 deraadt 916: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 917: &input_userauth_passwd_changereq);
918:
1.1 markus 919: return 1;
920: }
1.169 djm 921:
1.99 markus 922: /*
923: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
924: */
1.169 djm 925: /* ARGSUSED */
1.218 markus 926: int
1.153 djm 927: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 928: {
929: Authctxt *authctxt = ctxt;
930: char *info, *lang, *password = NULL, *retype = NULL;
931: char prompt[150];
1.175 dtucker 932: const char *host = options.host_key_alias ? options.host_key_alias :
933: authctxt->host;
1.99 markus 934:
935: debug2("input_userauth_passwd_changereq");
936:
937: if (authctxt == NULL)
938: fatal("input_userauth_passwd_changereq: "
939: "no authentication context");
940:
941: info = packet_get_string(NULL);
942: lang = packet_get_string(NULL);
943: if (strlen(info) > 0)
1.116 itojun 944: logit("%s", info);
1.197 djm 945: free(info);
946: free(lang);
1.99 markus 947: packet_start(SSH2_MSG_USERAUTH_REQUEST);
948: packet_put_cstring(authctxt->server_user);
949: packet_put_cstring(authctxt->service);
950: packet_put_cstring(authctxt->method->name);
951: packet_put_char(1); /* additional info */
1.104 deraadt 952: snprintf(prompt, sizeof(prompt),
1.99 markus 953: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 954: authctxt->server_user, host);
1.99 markus 955: password = read_passphrase(prompt, 0);
956: packet_put_cstring(password);
1.204 djm 957: explicit_bzero(password, strlen(password));
1.197 djm 958: free(password);
1.99 markus 959: password = NULL;
960: while (password == NULL) {
1.104 deraadt 961: snprintf(prompt, sizeof(prompt),
1.99 markus 962: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 963: authctxt->server_user, host);
1.99 markus 964: password = read_passphrase(prompt, RP_ALLOW_EOF);
965: if (password == NULL) {
966: /* bail out */
1.218 markus 967: return 0;
1.99 markus 968: }
1.104 deraadt 969: snprintf(prompt, sizeof(prompt),
1.99 markus 970: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 971: authctxt->server_user, host);
1.99 markus 972: retype = read_passphrase(prompt, 0);
973: if (strcmp(password, retype) != 0) {
1.204 djm 974: explicit_bzero(password, strlen(password));
1.197 djm 975: free(password);
1.116 itojun 976: logit("Mismatch; try again, EOF to quit.");
1.99 markus 977: password = NULL;
978: }
1.204 djm 979: explicit_bzero(retype, strlen(retype));
1.197 djm 980: free(retype);
1.99 markus 981: }
982: packet_put_cstring(password);
1.204 djm 983: explicit_bzero(password, strlen(password));
1.197 djm 984: free(password);
1.99 markus 985: packet_add_padding(64);
986: packet_send();
1.104 deraadt 987:
988: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 989: &input_userauth_passwd_changereq);
1.218 markus 990: return 0;
1.117 markus 991: }
992:
1.231 markus 993: static const char *
994: identity_sign_encode(struct identity *id)
995: {
996: struct ssh *ssh = active_state;
997:
998: if (id->key->type == KEY_RSA) {
999: switch (ssh->kex->rsa_sha2) {
1000: case 256:
1001: return "rsa-sha2-256";
1002: case 512:
1003: return "rsa-sha2-512";
1004: }
1005: }
1006: return key_ssh_name(id->key);
1007: }
1008:
1.117 markus 1009: static int
1.214 djm 1010: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1011: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1012: {
1013: Key *prv;
1014: int ret;
1.231 markus 1015: const char *alg;
1016:
1017: alg = identity_sign_encode(id);
1.99 markus 1018:
1.117 markus 1019: /* the agent supports this key */
1.230 djm 1020: if (id->agent_fd != -1)
1.214 djm 1021: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.231 markus 1022: data, datalen, alg, compat);
1.214 djm 1023:
1.117 markus 1024: /*
1025: * we have already loaded the private key or
1026: * the private key is stored in external hardware
1027: */
1.209 djm 1028: if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
1.231 markus 1029: return (sshkey_sign(id->key, sigp, lenp, data, datalen, alg,
1.214 djm 1030: compat));
1.117 markus 1031: /* load the private key from the file */
1.229 jcs 1032: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1033: return SSH_ERR_KEY_NOT_FOUND;
1.231 markus 1034: ret = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat);
1.214 djm 1035: sshkey_free(prv);
1.117 markus 1036: return (ret);
1.51 markus 1037: }
1038:
1.76 itojun 1039: static int
1.117 markus 1040: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1041: {
1042: Buffer b;
1.227 djm 1043: Identity *private_id;
1.32 markus 1044: u_char *blob, *signature;
1.214 djm 1045: size_t slen;
1.227 djm 1046: u_int bloblen, skip = 0;
1047: int matched, ret = -1, have_sig = 1;
1.182 djm 1048: char *fp;
1.1 markus 1049:
1.222 djm 1050: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1051: SSH_FP_DEFAULT)) == NULL)
1052: return 0;
1.227 djm 1053: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1054: free(fp);
1.51 markus 1055:
1.117 markus 1056: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1057: /* we cannot handle this key */
1.30 markus 1058: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1059: return 0;
1060: }
1.1 markus 1061: /* data to be signed */
1062: buffer_init(&b);
1.26 markus 1063: if (datafellows & SSH_OLD_SESSIONID) {
1064: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1065: skip = session_id2_len;
1.26 markus 1066: } else {
1.14 markus 1067: buffer_put_string(&b, session_id2, session_id2_len);
1068: skip = buffer_len(&b);
1069: }
1.1 markus 1070: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1071: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1072: buffer_put_cstring(&b,
1.30 markus 1073: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1074: "ssh-userauth" :
1.20 markus 1075: authctxt->service);
1.30 markus 1076: if (datafellows & SSH_BUG_PKAUTH) {
1077: buffer_put_char(&b, have_sig);
1078: } else {
1079: buffer_put_cstring(&b, authctxt->method->name);
1080: buffer_put_char(&b, have_sig);
1.231 markus 1081: buffer_put_cstring(&b, identity_sign_encode(id));
1.30 markus 1082: }
1.1 markus 1083: buffer_put_string(&b, blob, bloblen);
1084:
1.227 djm 1085: /*
1086: * If the key is an certificate, try to find a matching private key
1087: * and use it to complete the signature.
1.241 djm 1088: * If no such private key exists, fall back to trying the certificate
1089: * key itself in case it has a private half already loaded.
1.227 djm 1090: */
1091: if (key_is_cert(id->key)) {
1092: matched = 0;
1093: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1094: if (sshkey_equal_public(id->key, private_id->key) &&
1095: id->key->type != private_id->key->type) {
1096: id = private_id;
1097: matched = 1;
1098: break;
1099: }
1100: }
1101: if (matched) {
1102: debug2("%s: using private key \"%s\"%s for "
1103: "certificate", __func__, id->filename,
1104: id->agent_fd != -1 ? " from agent" : "");
1105: } else {
1.240 djm 1106: debug("%s: no separate private key for certificate "
1.227 djm 1107: "\"%s\"", __func__, id->filename);
1108: }
1109: }
1110:
1.1 markus 1111: /* generate signature */
1.117 markus 1112: ret = identity_sign(id, &signature, &slen,
1.214 djm 1113: buffer_ptr(&b), buffer_len(&b), datafellows);
1114: if (ret != 0) {
1.239 djm 1115: if (ret != SSH_ERR_KEY_NOT_FOUND)
1116: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1117: free(blob);
1.17 markus 1118: buffer_free(&b);
1119: return 0;
1120: }
1.28 markus 1121: #ifdef DEBUG_PK
1.1 markus 1122: buffer_dump(&b);
1123: #endif
1.30 markus 1124: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1125: buffer_clear(&b);
1126: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1127: skip = session_id2_len;
1.10 markus 1128: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1129: buffer_put_cstring(&b, authctxt->server_user);
1130: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1131: buffer_put_cstring(&b, authctxt->method->name);
1132: buffer_put_char(&b, have_sig);
1.30 markus 1133: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1134: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1135: buffer_put_string(&b, blob, bloblen);
1136: }
1.197 djm 1137: free(blob);
1.51 markus 1138:
1.1 markus 1139: /* append signature */
1140: buffer_put_string(&b, signature, slen);
1.197 djm 1141: free(signature);
1.1 markus 1142:
1143: /* skip session id and packet type */
1.14 markus 1144: if (buffer_len(&b) < skip + 1)
1.20 markus 1145: fatal("userauth_pubkey: internal error");
1.14 markus 1146: buffer_consume(&b, skip + 1);
1.1 markus 1147:
1148: /* put remaining data from buffer into packet */
1149: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1150: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1151: buffer_free(&b);
1152: packet_send();
1.17 markus 1153:
1154: return 1;
1.16 markus 1155: }
1156:
1.76 itojun 1157: static int
1.117 markus 1158: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1159: {
1.51 markus 1160: u_char *blob;
1.97 markus 1161: u_int bloblen, have_sig = 0;
1.20 markus 1162:
1.51 markus 1163: debug3("send_pubkey_test");
1.16 markus 1164:
1.117 markus 1165: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1166: /* we cannot handle this key */
1167: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1168: return 0;
1169: }
1.51 markus 1170: /* register callback for USERAUTH_PK_OK message */
1171: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1172:
1173: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1174: packet_put_cstring(authctxt->server_user);
1175: packet_put_cstring(authctxt->service);
1176: packet_put_cstring(authctxt->method->name);
1177: packet_put_char(have_sig);
1178: if (!(datafellows & SSH_BUG_PKAUTH))
1.231 markus 1179: packet_put_cstring(identity_sign_encode(id));
1.51 markus 1180: packet_put_string(blob, bloblen);
1.197 djm 1181: free(blob);
1.51 markus 1182: packet_send();
1183: return 1;
1184: }
1185:
1.76 itojun 1186: static Key *
1.229 jcs 1187: load_identity_file(Identity *id)
1.51 markus 1188: {
1.238 jsg 1189: Key *private = NULL;
1.229 jcs 1190: char prompt[300], *passphrase, *comment;
1.215 djm 1191: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1192: struct stat st;
1.16 markus 1193:
1.229 jcs 1194: if (stat(id->filename, &st) < 0) {
1195: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1196: id->filename, strerror(errno));
1.52 markus 1197: return NULL;
1198: }
1.214 djm 1199: snprintf(prompt, sizeof prompt,
1.229 jcs 1200: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1201: for (i = 0; i <= options.number_of_password_prompts; i++) {
1202: if (i == 0)
1203: passphrase = "";
1204: else {
1.20 markus 1205: passphrase = read_passphrase(prompt, 0);
1.214 djm 1206: if (*passphrase == '\0') {
1.20 markus 1207: debug2("no passphrase given, try next key");
1.214 djm 1208: free(passphrase);
1209: break;
1210: }
1211: }
1.229 jcs 1212: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1213: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1214: case 0:
1215: break;
1216: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1217: if (options.batch_mode) {
1218: quit = 1;
1219: break;
1220: }
1.215 djm 1221: if (i != 0)
1222: debug2("bad passphrase given, try again...");
1.214 djm 1223: break;
1224: case SSH_ERR_SYSTEM_ERROR:
1225: if (errno == ENOENT) {
1226: debug2("Load key \"%s\": %s",
1.229 jcs 1227: id->filename, ssh_err(r));
1.51 markus 1228: quit = 1;
1.214 djm 1229: break;
1.20 markus 1230: }
1.214 djm 1231: /* FALLTHROUGH */
1232: default:
1.229 jcs 1233: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1234: quit = 1;
1235: break;
1236: }
1.230 djm 1237: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1238: !(id->key && id->isprivate))
1239: maybe_add_key_to_agent(id->filename, private, comment,
1240: passphrase);
1.214 djm 1241: if (i > 0) {
1.204 djm 1242: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1243: free(passphrase);
1.16 markus 1244: }
1.232 mmcc 1245: free(comment);
1.214 djm 1246: if (private != NULL || quit)
1247: break;
1.16 markus 1248: }
1.51 markus 1249: return private;
1250: }
1251:
1.117 markus 1252: /*
1253: * try keys in the following order:
1.227 djm 1254: * 1. certificates listed in the config file
1255: * 2. other input certificates
1256: * 3. agent keys that are found in the config file
1257: * 4. other agent keys
1258: * 5. keys that are only listed in the config file
1.117 markus 1259: */
1260: static void
1261: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1262: {
1.214 djm 1263: struct identity *id, *id2, *tmp;
1264: struct idlist agent, files, *preferred;
1265: struct sshkey *key;
1.230 djm 1266: int agent_fd = -1, i, r, found;
1.214 djm 1267: size_t j;
1268: struct ssh_identitylist *idlist;
1.51 markus 1269:
1.117 markus 1270: TAILQ_INIT(&agent); /* keys from the agent */
1271: TAILQ_INIT(&files); /* keys from the config file */
1272: preferred = &authctxt->keys;
1273: TAILQ_INIT(preferred); /* preferred order of keys */
1274:
1.190 djm 1275: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1276: for (i = 0; i < options.num_identity_files; i++) {
1277: key = options.identity_keys[i];
1278: if (key && key->type == KEY_RSA1)
1.180 djm 1279: continue;
1280: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1281: continue;
1282: options.identity_keys[i] = NULL;
1.150 djm 1283: id = xcalloc(1, sizeof(*id));
1.230 djm 1284: id->agent_fd = -1;
1.117 markus 1285: id->key = key;
1286: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1287: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1288: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1289: }
1.227 djm 1290: /* list of certificates specified by user */
1291: for (i = 0; i < options.num_certificate_files; i++) {
1292: key = options.certificates[i];
1293: if (!key_is_cert(key) || key->cert == NULL ||
1294: key->cert->type != SSH2_CERT_TYPE_USER)
1295: continue;
1296: id = xcalloc(1, sizeof(*id));
1.230 djm 1297: id->agent_fd = -1;
1.227 djm 1298: id->key = key;
1299: id->filename = xstrdup(options.certificate_files[i]);
1300: id->userprovided = options.certificate_file_userprovided[i];
1301: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1302: }
1303: /* list of keys supported by the agent */
1.214 djm 1304: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1305: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1306: debug("%s: ssh_get_authentication_socket: %s",
1307: __func__, ssh_err(r));
1308: } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1309: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1310: debug("%s: ssh_fetch_identitylist: %s",
1311: __func__, ssh_err(r));
1.237 markus 1312: close(agent_fd);
1.214 djm 1313: } else {
1314: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1315: found = 0;
1316: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1317: /*
1318: * agent keys from the config file are
1319: * preferred
1320: */
1321: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1322: TAILQ_REMOVE(&files, id, next);
1323: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1324: id->agent_fd = agent_fd;
1.117 markus 1325: found = 1;
1326: break;
1327: }
1328: }
1.135 markus 1329: if (!found && !options.identities_only) {
1.150 djm 1330: id = xcalloc(1, sizeof(*id));
1.214 djm 1331: /* XXX "steals" key/comment from idlist */
1332: id->key = idlist->keys[j];
1333: id->filename = idlist->comments[j];
1334: idlist->keys[j] = NULL;
1335: idlist->comments[j] = NULL;
1336: id->agent_fd = agent_fd;
1.117 markus 1337: TAILQ_INSERT_TAIL(&agent, id, next);
1338: }
1339: }
1.214 djm 1340: ssh_free_identitylist(idlist);
1.117 markus 1341: /* append remaining agent keys */
1342: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1343: TAILQ_REMOVE(&agent, id, next);
1344: TAILQ_INSERT_TAIL(preferred, id, next);
1345: }
1.214 djm 1346: authctxt->agent_fd = agent_fd;
1.244 djm 1347: }
1348: /* Prefer PKCS11 keys that are explicitly listed */
1349: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1350: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1351: continue;
1352: found = 0;
1353: TAILQ_FOREACH(id2, &files, next) {
1354: if (id2->key == NULL ||
1355: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1356: continue;
1357: if (sshkey_equal(id->key, id2->key)) {
1358: TAILQ_REMOVE(&files, id, next);
1359: TAILQ_INSERT_TAIL(preferred, id, next);
1360: found = 1;
1361: break;
1362: }
1363: }
1364: /* If IdentitiesOnly set and key not found then don't use it */
1365: if (!found && options.identities_only) {
1366: TAILQ_REMOVE(&files, id, next);
1367: explicit_bzero(id, sizeof(*id));
1368: free(id);
1369: }
1.117 markus 1370: }
1371: /* append remaining keys from the config file */
1372: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1373: TAILQ_REMOVE(&files, id, next);
1374: TAILQ_INSERT_TAIL(preferred, id, next);
1375: }
1.228 djm 1376: /* finally, filter by PubkeyAcceptedKeyTypes */
1377: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1378: if (id->key != NULL &&
1379: match_pattern_list(sshkey_ssh_name(id->key),
1380: options.pubkey_key_types, 0) != 1) {
1381: debug("Skipping %s key %s - "
1382: "not in PubkeyAcceptedKeyTypes",
1383: sshkey_ssh_name(id->key), id->filename);
1384: TAILQ_REMOVE(preferred, id, next);
1385: sshkey_free(id->key);
1386: free(id->filename);
1387: memset(id, 0, sizeof(*id));
1388: continue;
1389: }
1.230 djm 1390: debug2("key: %s (%p)%s%s", id->filename, id->key,
1391: id->userprovided ? ", explicit" : "",
1392: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1393: }
1.17 markus 1394: }
1395:
1.117 markus 1396: static void
1397: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1398: {
1.117 markus 1399: Identity *id;
1.51 markus 1400:
1.214 djm 1401: if (authctxt->agent_fd != -1)
1402: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1403: for (id = TAILQ_FIRST(&authctxt->keys); id;
1404: id = TAILQ_FIRST(&authctxt->keys)) {
1405: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1406: sshkey_free(id->key);
1.197 djm 1407: free(id->filename);
1408: free(id);
1.117 markus 1409: }
1.1 markus 1410: }
1411:
1.225 markus 1412: static int
1413: try_identity(Identity *id)
1414: {
1415: if (!id->key)
1416: return (0);
1417: if (key_type_plain(id->key->type) == KEY_RSA &&
1418: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1419: debug("Skipped %s key %s for RSA/MD5 server",
1420: key_type(id->key), id->filename);
1421: return (0);
1422: }
1423: return (id->key->type != KEY_RSA1);
1424: }
1425:
1.20 markus 1426: int
1427: userauth_pubkey(Authctxt *authctxt)
1428: {
1.117 markus 1429: Identity *id;
1.20 markus 1430: int sent = 0;
1431:
1.117 markus 1432: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1433: if (id->tried++)
1434: return (0);
1.127 markus 1435: /* move key to the end of the queue */
1.117 markus 1436: TAILQ_REMOVE(&authctxt->keys, id, next);
1437: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1438: /*
1439: * send a test message if we have the public key. for
1440: * encrypted keys we cannot do this and have to load the
1441: * private key instead
1442: */
1.200 djm 1443: if (id->key != NULL) {
1.225 markus 1444: if (try_identity(id)) {
1.200 djm 1445: debug("Offering %s public key: %s",
1446: key_type(id->key), id->filename);
1447: sent = send_pubkey_test(authctxt, id);
1448: }
1449: } else {
1.117 markus 1450: debug("Trying private key: %s", id->filename);
1.229 jcs 1451: id->key = load_identity_file(id);
1.117 markus 1452: if (id->key != NULL) {
1.225 markus 1453: if (try_identity(id)) {
1454: id->isprivate = 1;
1.200 djm 1455: sent = sign_and_send_pubkey(
1456: authctxt, id);
1457: }
1.117 markus 1458: key_free(id->key);
1459: id->key = NULL;
1.51 markus 1460: }
1461: }
1.117 markus 1462: if (sent)
1463: return (sent);
1.28 markus 1464: }
1.117 markus 1465: return (0);
1.20 markus 1466: }
1467:
1.23 markus 1468: /*
1469: * Send userauth request message specifying keyboard-interactive method.
1470: */
1471: int
1472: userauth_kbdint(Authctxt *authctxt)
1473: {
1474: static int attempt = 0;
1475:
1476: if (attempt++ >= options.number_of_password_prompts)
1477: return 0;
1.82 markus 1478: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1479: if (attempt > 1 && !authctxt->info_req_seen) {
1480: debug3("userauth_kbdint: disable: no info_req_seen");
1481: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1482: return 0;
1483: }
1.23 markus 1484:
1485: debug2("userauth_kbdint");
1486: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1487: packet_put_cstring(authctxt->server_user);
1488: packet_put_cstring(authctxt->service);
1489: packet_put_cstring(authctxt->method->name);
1490: packet_put_cstring(""); /* lang */
1491: packet_put_cstring(options.kbd_interactive_devices ?
1492: options.kbd_interactive_devices : "");
1493: packet_send();
1494:
1495: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1496: return 1;
1497: }
1498:
1499: /*
1.46 markus 1500: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1501: */
1.218 markus 1502: int
1.92 markus 1503: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1504: {
1505: Authctxt *authctxt = ctxt;
1.46 markus 1506: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1507: u_int num_prompts, i;
1.23 markus 1508: int echo = 0;
1509:
1510: debug2("input_userauth_info_req");
1511:
1512: if (authctxt == NULL)
1513: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1514:
1515: authctxt->info_req_seen = 1;
1.23 markus 1516:
1517: name = packet_get_string(NULL);
1518: inst = packet_get_string(NULL);
1519: lang = packet_get_string(NULL);
1520: if (strlen(name) > 0)
1.116 itojun 1521: logit("%s", name);
1.23 markus 1522: if (strlen(inst) > 0)
1.116 itojun 1523: logit("%s", inst);
1.197 djm 1524: free(name);
1525: free(inst);
1526: free(lang);
1.23 markus 1527:
1528: num_prompts = packet_get_int();
1529: /*
1530: * Begin to build info response packet based on prompts requested.
1531: * We commit to providing the correct number of responses, so if
1532: * further on we run into a problem that prevents this, we have to
1533: * be sure and clean this up and send a correct error response.
1534: */
1535: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1536: packet_put_int(num_prompts);
1537:
1.73 markus 1538: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1539: for (i = 0; i < num_prompts; i++) {
1540: prompt = packet_get_string(NULL);
1541: echo = packet_get_char();
1542:
1.77 markus 1543: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1544:
1.49 markus 1545: packet_put_cstring(response);
1.204 djm 1546: explicit_bzero(response, strlen(response));
1.197 djm 1547: free(response);
1548: free(prompt);
1.23 markus 1549: }
1.90 markus 1550: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1551:
1.85 markus 1552: packet_add_padding(64);
1.23 markus 1553: packet_send();
1.218 markus 1554: return 0;
1.68 markus 1555: }
1556:
1.100 markus 1557: static int
1.223 djm 1558: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1559: const u_char *data, size_t datalen)
1.100 markus 1560: {
1.223 djm 1561: struct sshbuf *b;
1.101 markus 1562: struct stat st;
1.100 markus 1563: pid_t pid;
1.223 djm 1564: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1565: u_char rversion = 0, version = 2;
1566: void (*osigchld)(int);
1.100 markus 1567:
1.223 djm 1568: *sigp = NULL;
1569: *lenp = 0;
1.100 markus 1570:
1.101 markus 1571: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1572: error("%s: not installed: %s", __func__, strerror(errno));
1573: return -1;
1574: }
1575: if (fflush(stdout) != 0) {
1576: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1577: return -1;
1578: }
1.100 markus 1579: if (pipe(to) < 0) {
1.223 djm 1580: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1581: return -1;
1582: }
1583: if (pipe(from) < 0) {
1.223 djm 1584: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1585: return -1;
1586: }
1587: if ((pid = fork()) < 0) {
1.223 djm 1588: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1589: return -1;
1590: }
1.223 djm 1591: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1592: if (pid == 0) {
1.174 dtucker 1593: /* keep the socket on exec */
1.223 djm 1594: fcntl(sock, F_SETFD, 0);
1.155 markus 1595: permanently_drop_suid(getuid());
1.100 markus 1596: close(from[0]);
1597: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1598: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1599: close(to[1]);
1600: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1601: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1602: close(from[1]);
1603: close(to[0]);
1.223 djm 1604: /* Close everything but stdio and the socket */
1605: for (i = STDERR_FILENO + 1; i < sock; i++)
1606: close(i);
1607: closefrom(sock + 1);
1608: debug3("%s: [child] pid=%ld, exec %s",
1609: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1610: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1611: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1612: strerror(errno));
1613: }
1614: close(from[1]);
1615: close(to[0]);
1616:
1.223 djm 1617: if ((b = sshbuf_new()) == NULL)
1618: fatal("%s: sshbuf_new failed", __func__);
1619: /* send # of sock, data to be signed */
1620: if ((r = sshbuf_put_u32(b, sock) != 0) ||
1621: (r = sshbuf_put_string(b, data, datalen)) != 0)
1622: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1623: if (ssh_msg_send(to[1], version, b) == -1)
1624: fatal("%s: couldn't send request", __func__);
1625: sshbuf_reset(b);
1626: r = ssh_msg_recv(from[0], b);
1.101 markus 1627: close(from[0]);
1628: close(to[1]);
1.223 djm 1629: if (r < 0) {
1630: error("%s: no reply", __func__);
1631: goto fail;
1632: }
1.101 markus 1633:
1.223 djm 1634: errno = 0;
1635: while (waitpid(pid, &status, 0) < 0) {
1636: if (errno != EINTR) {
1637: error("%s: waitpid %ld: %s",
1638: __func__, (long)pid, strerror(errno));
1639: goto fail;
1640: }
1641: }
1642: if (!WIFEXITED(status)) {
1643: error("%s: exited abnormally", __func__);
1644: goto fail;
1645: }
1646: if (WEXITSTATUS(status) != 0) {
1647: error("%s: exited with status %d",
1648: __func__, WEXITSTATUS(status));
1649: goto fail;
1650: }
1651: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1652: error("%s: buffer error: %s", __func__, ssh_err(r));
1653: goto fail;
1654: }
1655: if (rversion != version) {
1656: error("%s: bad version", __func__);
1657: goto fail;
1658: }
1659: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1660: error("%s: buffer error: %s", __func__, ssh_err(r));
1661: fail:
1662: signal(SIGCHLD, osigchld);
1663: sshbuf_free(b);
1.100 markus 1664: return -1;
1665: }
1.223 djm 1666: signal(SIGCHLD, osigchld);
1667: sshbuf_free(b);
1.100 markus 1668:
1669: return 0;
1670: }
1671:
1.68 markus 1672: int
1673: userauth_hostbased(Authctxt *authctxt)
1674: {
1.223 djm 1675: struct ssh *ssh = active_state;
1676: struct sshkey *private = NULL;
1677: struct sshbuf *b = NULL;
1.72 markus 1678: const char *service;
1.223 djm 1679: u_char *sig = NULL, *keyblob = NULL;
1680: char *fp = NULL, *chost = NULL, *lname = NULL;
1681: size_t siglen = 0, keylen = 0;
1682: int i, r, success = 0;
1683:
1684: if (authctxt->ktypes == NULL) {
1685: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1686: authctxt->ktypes = authctxt->oktypes;
1687: }
1.213 djm 1688:
1.223 djm 1689: /*
1690: * Work through each listed type pattern in HostbasedKeyTypes,
1691: * trying each hostkey that matches the type in turn.
1692: */
1693: for (;;) {
1694: if (authctxt->active_ktype == NULL)
1695: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1696: if (authctxt->active_ktype == NULL ||
1697: *authctxt->active_ktype == '\0')
1698: break;
1699: debug3("%s: trying key type %s", __func__,
1700: authctxt->active_ktype);
1.68 markus 1701:
1.223 djm 1702: /* check for a useful key */
1703: private = NULL;
1704: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1705: if (authctxt->sensitive->keys[i] == NULL ||
1706: authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
1707: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1708: continue;
1709: if (match_pattern_list(
1710: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1711: authctxt->active_ktype, 0) != 1)
1.223 djm 1712: continue;
1.68 markus 1713: /* we take and free the key */
1.223 djm 1714: private = authctxt->sensitive->keys[i];
1715: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1716: break;
1717: }
1.223 djm 1718: /* Found one */
1719: if (private != NULL)
1720: break;
1721: /* No more keys of this type; advance */
1722: authctxt->active_ktype = NULL;
1.68 markus 1723: }
1.223 djm 1724: if (private == NULL) {
1725: free(authctxt->oktypes);
1726: authctxt->oktypes = authctxt->ktypes = NULL;
1727: authctxt->active_ktype = NULL;
1.109 markus 1728: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1729: goto out;
1.68 markus 1730: }
1.211 djm 1731:
1.223 djm 1732: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1733: SSH_FP_DEFAULT)) == NULL) {
1734: error("%s: sshkey_fingerprint failed", __func__);
1735: goto out;
1.68 markus 1736: }
1.223 djm 1737: debug("%s: trying hostkey %s %s",
1738: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1739:
1.84 markus 1740: /* figure out a name for the client host */
1.223 djm 1741: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1742: error("%s: cannot get local ipaddr/name", __func__);
1743: goto out;
1.84 markus 1744: }
1.223 djm 1745:
1746: /* XXX sshbuf_put_stringf? */
1747: xasprintf(&chost, "%s.", lname);
1748: debug2("%s: chost %s", __func__, chost);
1.84 markus 1749:
1.72 markus 1750: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1751: authctxt->service;
1.223 djm 1752:
1.68 markus 1753: /* construct data */
1.223 djm 1754: if ((b = sshbuf_new()) == NULL) {
1755: error("%s: sshbuf_new failed", __func__);
1756: goto out;
1757: }
1758: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1759: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1760: goto out;
1761: }
1762: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1763: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1764: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1765: (r = sshbuf_put_cstring(b, service)) != 0 ||
1766: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1767: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1768: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1769: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1770: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1771: error("%s: buffer error: %s", __func__, ssh_err(r));
1772: goto out;
1773: }
1774:
1.68 markus 1775: #ifdef DEBUG_PK
1.223 djm 1776: sshbuf_dump(b, stderr);
1.68 markus 1777: #endif
1.223 djm 1778: if (authctxt->sensitive->external_keysign)
1779: r = ssh_keysign(private, &sig, &siglen,
1780: sshbuf_ptr(b), sshbuf_len(b));
1781: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1782: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1783: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1784: if (r != 0) {
1785: error("sign using hostkey %s %s failed",
1786: sshkey_ssh_name(private), fp);
1787: goto out;
1788: }
1789: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1790: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1791: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1792: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1793: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1794: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1795: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1796: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1797: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1798: (r = sshpkt_send(ssh)) != 0) {
1799: error("%s: packet error: %s", __func__, ssh_err(r));
1800: goto out;
1801: }
1802: success = 1;
1803:
1804: out:
1805: if (sig != NULL) {
1806: explicit_bzero(sig, siglen);
1807: free(sig);
1.68 markus 1808: }
1.223 djm 1809: free(keyblob);
1810: free(lname);
1811: free(fp);
1.197 djm 1812: free(chost);
1.223 djm 1813: sshkey_free(private);
1814: sshbuf_free(b);
1.68 markus 1815:
1.223 djm 1816: return success;
1.23 markus 1817: }
1.170 djm 1818:
1.20 markus 1819: /* find auth method */
1820:
1821: /*
1822: * given auth method name, if configurable options permit this method fill
1823: * in auth_ident field and return true, otherwise return false.
1824: */
1.76 itojun 1825: static int
1.20 markus 1826: authmethod_is_enabled(Authmethod *method)
1827: {
1828: if (method == NULL)
1829: return 0;
1830: /* return false if options indicate this method is disabled */
1831: if (method->enabled == NULL || *method->enabled == 0)
1832: return 0;
1833: /* return false if batch mode is enabled but method needs interactive mode */
1834: if (method->batch_flag != NULL && *method->batch_flag != 0)
1835: return 0;
1836: return 1;
1837: }
1838:
1.76 itojun 1839: static Authmethod *
1.20 markus 1840: authmethod_lookup(const char *name)
1.1 markus 1841: {
1.20 markus 1842: Authmethod *method = NULL;
1843: if (name != NULL)
1844: for (method = authmethods; method->name != NULL; method++)
1845: if (strcmp(name, method->name) == 0)
1846: return method;
1847: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1848: return NULL;
1849: }
1.1 markus 1850:
1.53 markus 1851: /* XXX internal state */
1852: static Authmethod *current = NULL;
1853: static char *supported = NULL;
1854: static char *preferred = NULL;
1.105 deraadt 1855:
1.20 markus 1856: /*
1857: * Given the authentication method list sent by the server, return the
1858: * next method we should try. If the server initially sends a nil list,
1.67 markus 1859: * use a built-in default list.
1.41 stevesk 1860: */
1.76 itojun 1861: static Authmethod *
1.20 markus 1862: authmethod_get(char *authlist)
1863: {
1.53 markus 1864: char *name = NULL;
1.97 markus 1865: u_int next;
1.41 stevesk 1866:
1.20 markus 1867: /* Use a suitable default if we're passed a nil list. */
1868: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1869: authlist = options.preferred_authentications;
1.20 markus 1870:
1.53 markus 1871: if (supported == NULL || strcmp(authlist, supported) != 0) {
1872: debug3("start over, passed a different list %s", authlist);
1.197 djm 1873: free(supported);
1.53 markus 1874: supported = xstrdup(authlist);
1875: preferred = options.preferred_authentications;
1876: debug3("preferred %s", preferred);
1877: current = NULL;
1878: } else if (current != NULL && authmethod_is_enabled(current))
1879: return current;
1.20 markus 1880:
1.53 markus 1881: for (;;) {
1882: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1883: debug("No more authentication methods to try.");
1.53 markus 1884: current = NULL;
1885: return NULL;
1886: }
1887: preferred += next;
1.23 markus 1888: debug3("authmethod_lookup %s", name);
1.53 markus 1889: debug3("remaining preferred: %s", preferred);
1890: if ((current = authmethod_lookup(name)) != NULL &&
1891: authmethod_is_enabled(current)) {
1.23 markus 1892: debug3("authmethod_is_enabled %s", name);
1.109 markus 1893: debug("Next authentication method: %s", name);
1.197 djm 1894: free(name);
1.53 markus 1895: return current;
1.23 markus 1896: }
1.198 dtucker 1897: free(name);
1.1 markus 1898: }
1.53 markus 1899: }
1.1 markus 1900:
1.79 stevesk 1901: static char *
1.53 markus 1902: authmethods_get(void)
1903: {
1904: Authmethod *method = NULL;
1.93 markus 1905: Buffer b;
1906: char *list;
1.27 provos 1907:
1.93 markus 1908: buffer_init(&b);
1.53 markus 1909: for (method = authmethods; method->name != NULL; method++) {
1910: if (authmethod_is_enabled(method)) {
1.93 markus 1911: if (buffer_len(&b) > 0)
1912: buffer_append(&b, ",", 1);
1913: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1914: }
1915: }
1.242 djm 1916: if ((list = sshbuf_dup_string(&b)) == NULL)
1917: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1918: buffer_free(&b);
1919: return list;
1.1 markus 1920: }
1.170 djm 1921:
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