Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.246
1.246 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.245 2016/05/24 04:43:45 dtucker 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"
1.246 ! djm 68: #include "utf8.h"
1.22 provos 69:
1.121 markus 70: #ifdef GSSAPI
71: #include "ssh-gss.h"
72: #endif
73:
1.1 markus 74: /* import */
75: extern char *client_version_string;
76: extern char *server_version_string;
77: extern Options options;
78:
79: /*
80: * SSH2 key exchange
81: */
82:
1.32 markus 83: u_char *session_id2 = NULL;
1.120 markus 84: u_int session_id2_len = 0;
1.1 markus 85:
1.61 markus 86: char *xxx_host;
87: struct sockaddr *xxx_hostaddr;
88:
1.76 itojun 89: static int
1.219 markus 90: verify_host_key_callback(Key *hostkey, struct ssh *ssh)
1.61 markus 91: {
1.75 markus 92: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 93: fatal("Host key verification failed.");
1.61 markus 94: return 0;
95: }
96:
1.186 djm 97: static char *
98: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
99: {
100: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
101: size_t maxlen;
102: struct hostkeys *hostkeys;
103: int ktype;
1.188 djm 104: u_int i;
1.186 djm 105:
106: /* Find all hostkeys for this hostname */
107: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
108: hostkeys = init_hostkeys();
1.188 djm 109: for (i = 0; i < options.num_user_hostfiles; i++)
110: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
111: for (i = 0; i < options.num_system_hostfiles; i++)
112: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 113:
114: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
115: maxlen = strlen(avail) + 1;
116: first = xmalloc(maxlen);
117: last = xmalloc(maxlen);
118: *first = *last = '\0';
119:
120: #define ALG_APPEND(to, from) \
121: do { \
122: if (*to != '\0') \
123: strlcat(to, ",", maxlen); \
124: strlcat(to, from, maxlen); \
125: } while (0)
126:
127: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 128: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 129: fatal("%s: unknown alg %s", __func__, alg);
130: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 131: sshkey_type_plain(ktype), NULL))
1.186 djm 132: ALG_APPEND(first, alg);
133: else
134: ALG_APPEND(last, alg);
135: }
136: #undef ALG_APPEND
1.216 djm 137: xasprintf(&ret, "%s%s%s", first,
138: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 139: if (*first != '\0')
140: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
141:
1.197 djm 142: free(first);
143: free(last);
144: free(hostname);
145: free(oavail);
1.186 djm 146: free_hostkeys(hostkeys);
147:
148: return ret;
149: }
150:
1.1 markus 151: void
1.186 djm 152: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 153: {
1.205 markus 154: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.231 markus 155: char *s;
1.219 markus 156: struct kex *kex;
1.221 markus 157: int r;
1.61 markus 158:
159: xxx_host = host;
160: xxx_hostaddr = hostaddr;
1.22 provos 161:
1.231 markus 162: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
163: fatal("%s: kex_names_cat", __func__);
164: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
1.60 stevesk 165: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.226 djm 166: compat_cipher_proposal(options.ciphers);
1.60 stevesk 167: myproposal[PROPOSAL_ENC_ALGS_STOC] =
1.226 djm 168: compat_cipher_proposal(options.ciphers);
1.245 dtucker 169: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
170: myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ?
171: "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib";
1.226 djm 172: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
173: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
174: if (options.hostkeyalgorithms != NULL) {
175: if (kex_assemble_names(KEX_DEFAULT_PK_ALG,
176: &options.hostkeyalgorithms) != 0)
177: fatal("%s: kex_assemble_namelist", __func__);
1.88 deraadt 178: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 179: compat_pkalg_proposal(options.hostkeyalgorithms);
1.226 djm 180: } else {
1.225 markus 181: /* Enforce default */
182: options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
1.186 djm 183: /* Prefer algorithms that we already have keys for */
184: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 185: compat_pkalg_proposal(
186: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 187: }
1.115 markus 188:
1.196 dtucker 189: if (options.rekey_limit || options.rekey_interval)
190: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
191: (time_t)options.rekey_interval);
1.22 provos 192:
1.65 markus 193: /* start key exchange */
1.221 markus 194: if ((r = kex_setup(active_state, myproposal)) != 0)
195: fatal("kex_setup: %s", ssh_err(r));
1.219 markus 196: kex = active_state->kex;
1.207 markus 197: #ifdef WITH_OPENSSL
1.111 markus 198: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 199: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.243 djm 200: kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
201: kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
202: kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client;
1.111 markus 203: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 204: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 205: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.207 markus 206: #endif
1.199 markus 207: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 208: kex->client_version_string=client_version_string;
209: kex->server_version_string=server_version_string;
1.75 markus 210: kex->verify_host_key=&verify_host_key_callback;
1.22 provos 211:
1.219 markus 212: dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
1.173 andreas 213:
1.231 markus 214: /* remove ext-info from the KEX proposals for rekeying */
215: myproposal[PROPOSAL_KEX_ALGS] =
216: compat_kex_proposal(options.kex_algorithms);
217: if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
218: fatal("kex_prop2buf: %s", ssh_err(r));
1.62 markus 219:
220: session_id2 = kex->session_id;
221: session_id2_len = kex->session_id_len;
1.22 provos 222:
223: #ifdef DEBUG_KEXDH
224: /* send 1st encrypted/maced/compressed message */
225: packet_start(SSH2_MSG_IGNORE);
226: packet_put_cstring("markus");
227: packet_send();
228: packet_write_wait();
229: #endif
1.1 markus 230: }
1.11 markus 231:
1.1 markus 232: /*
233: * Authenticate user
234: */
1.20 markus 235:
1.214 djm 236: typedef struct cauthctxt Authctxt;
237: typedef struct cauthmethod Authmethod;
1.117 markus 238: typedef struct identity Identity;
239: typedef struct idlist Idlist;
1.20 markus 240:
1.117 markus 241: struct identity {
242: TAILQ_ENTRY(identity) next;
1.214 djm 243: int agent_fd; /* >=0 if agent supports key */
244: struct sshkey *key; /* public/private key */
1.117 markus 245: char *filename; /* comment for agent-only keys */
246: int tried;
247: int isprivate; /* key points to the private key */
1.191 dtucker 248: int userprovided;
1.117 markus 249: };
250: TAILQ_HEAD(idlist, identity);
1.20 markus 251:
1.214 djm 252: struct cauthctxt {
1.20 markus 253: const char *server_user;
1.68 markus 254: const char *local_user;
1.20 markus 255: const char *host;
256: const char *service;
1.214 djm 257: struct cauthmethod *method;
1.183 djm 258: sig_atomic_t success;
1.51 markus 259: char *authlist;
1.214 djm 260: int attempt;
1.68 markus 261: /* pubkey */
1.214 djm 262: struct idlist keys;
263: int agent_fd;
1.68 markus 264: /* hostbased */
1.100 markus 265: Sensitive *sensitive;
1.223 djm 266: char *oktypes, *ktypes;
267: const char *active_ktype;
1.82 markus 268: /* kbd-interactive */
269: int info_req_seen;
1.121 markus 270: /* generic */
271: void *methoddata;
1.20 markus 272: };
1.214 djm 273:
274: struct cauthmethod {
1.20 markus 275: char *name; /* string to compare against server's list */
276: int (*userauth)(Authctxt *authctxt);
1.170 djm 277: void (*cleanup)(Authctxt *authctxt);
1.20 markus 278: int *enabled; /* flag in option struct that enables method */
279: int *batch_flag; /* flag in option struct that disables method */
280: };
281:
1.231 markus 282: int input_userauth_service_accept(int, u_int32_t, void *);
283: int input_userauth_ext_info(int, u_int32_t, void *);
1.218 markus 284: int input_userauth_success(int, u_int32_t, void *);
285: int input_userauth_success_unexpected(int, u_int32_t, void *);
286: int input_userauth_failure(int, u_int32_t, void *);
287: int input_userauth_banner(int, u_int32_t, void *);
288: int input_userauth_error(int, u_int32_t, void *);
289: int input_userauth_info_req(int, u_int32_t, void *);
290: int input_userauth_pk_ok(int, u_int32_t, void *);
291: int input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 292:
293: int userauth_none(Authctxt *);
294: int userauth_pubkey(Authctxt *);
295: int userauth_passwd(Authctxt *);
296: int userauth_kbdint(Authctxt *);
297: int userauth_hostbased(Authctxt *);
1.20 markus 298:
1.121 markus 299: #ifdef GSSAPI
300: int userauth_gssapi(Authctxt *authctxt);
1.218 markus 301: int input_gssapi_response(int type, u_int32_t, void *);
302: int input_gssapi_token(int type, u_int32_t, void *);
303: int input_gssapi_hash(int type, u_int32_t, void *);
304: int input_gssapi_error(int, u_int32_t, void *);
305: int input_gssapi_errtok(int, u_int32_t, void *);
1.121 markus 306: #endif
307:
1.86 itojun 308: void userauth(Authctxt *, char *);
1.51 markus 309:
1.117 markus 310: static int sign_and_send_pubkey(Authctxt *, Identity *);
311: static void pubkey_prepare(Authctxt *);
312: static void pubkey_cleanup(Authctxt *);
1.229 jcs 313: static Key *load_identity_file(Identity *);
1.76 itojun 314:
315: static Authmethod *authmethod_get(char *authlist);
316: static Authmethod *authmethod_lookup(const char *name);
317: static char *authmethods_get(void);
1.20 markus 318:
319: Authmethod authmethods[] = {
1.121 markus 320: #ifdef GSSAPI
1.132 markus 321: {"gssapi-with-mic",
1.121 markus 322: userauth_gssapi,
1.170 djm 323: NULL,
1.121 markus 324: &options.gss_authentication,
325: NULL},
326: #endif
1.81 markus 327: {"hostbased",
328: userauth_hostbased,
1.170 djm 329: NULL,
1.81 markus 330: &options.hostbased_authentication,
331: NULL},
1.20 markus 332: {"publickey",
333: userauth_pubkey,
1.170 djm 334: NULL,
1.28 markus 335: &options.pubkey_authentication,
1.20 markus 336: NULL},
1.81 markus 337: {"keyboard-interactive",
338: userauth_kbdint,
1.170 djm 339: NULL,
1.81 markus 340: &options.kbd_interactive_authentication,
341: &options.batch_mode},
1.20 markus 342: {"password",
343: userauth_passwd,
1.170 djm 344: NULL,
1.20 markus 345: &options.password_authentication,
1.23 markus 346: &options.batch_mode},
347: {"none",
348: userauth_none,
349: NULL,
1.170 djm 350: NULL,
1.23 markus 351: NULL},
1.170 djm 352: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 353: };
354:
355: void
1.68 markus 356: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 357: Sensitive *sensitive)
1.20 markus 358: {
1.231 markus 359: struct ssh *ssh = active_state;
1.20 markus 360: Authctxt authctxt;
1.231 markus 361: int r;
1.39 markus 362:
1.73 markus 363: if (options.challenge_response_authentication)
1.39 markus 364: options.kbd_interactive_authentication = 1;
1.53 markus 365: if (options.preferred_authentications == NULL)
366: options.preferred_authentications = authmethods_get();
367:
1.20 markus 368: /* setup authentication context */
1.82 markus 369: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 370: pubkey_prepare(&authctxt);
1.20 markus 371: authctxt.server_user = server_user;
1.68 markus 372: authctxt.local_user = local_user;
1.20 markus 373: authctxt.host = host;
374: authctxt.service = "ssh-connection"; /* service name */
375: authctxt.success = 0;
1.23 markus 376: authctxt.method = authmethod_lookup("none");
1.51 markus 377: authctxt.authlist = NULL;
1.121 markus 378: authctxt.methoddata = NULL;
1.100 markus 379: authctxt.sensitive = sensitive;
1.223 djm 380: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 381: authctxt.info_req_seen = 0;
1.215 djm 382: authctxt.agent_fd = -1;
1.23 markus 383: if (authctxt.method == NULL)
384: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 385:
1.231 markus 386: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
387: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
388: (r = sshpkt_send(ssh)) != 0)
389: fatal("%s: %s", __func__, ssh_err(r));
390:
391: ssh_dispatch_init(ssh, &input_userauth_error);
392: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
393: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
394: ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
1.20 markus 395:
1.117 markus 396: pubkey_cleanup(&authctxt);
1.231 markus 397: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 398:
1.109 markus 399: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 400: }
1.119 markus 401:
1.231 markus 402: /* ARGSUSED */
403: int
404: input_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt)
405: {
406: Authctxt *authctxt = ctxt;
407: struct ssh *ssh = active_state;
408: int r;
409:
410: if (ssh_packet_remaining(ssh) > 0) {
411: char *reply;
412:
413: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
414: goto out;
415: debug2("service_accept: %s", reply);
416: free(reply);
417: } else {
418: debug2("buggy server: service_accept w/o service");
419: }
420: if ((r = sshpkt_get_end(ssh)) != 0)
421: goto out;
422: debug("SSH2_MSG_SERVICE_ACCEPT received");
423:
424: /* initial userauth request */
425: userauth_none(authctxt);
426:
427: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
428: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
429: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
430: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
431: r = 0;
432: out:
433: return r;
434: }
435:
436: /* ARGSUSED */
437: int
438: input_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt)
439: {
440: return kex_input_ext_info(type, seqnr, active_state);
441: }
442:
1.20 markus 443: void
1.51 markus 444: userauth(Authctxt *authctxt, char *authlist)
445: {
1.170 djm 446: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
447: authctxt->method->cleanup(authctxt);
448:
1.197 djm 449: free(authctxt->methoddata);
450: authctxt->methoddata = NULL;
1.51 markus 451: if (authlist == NULL) {
452: authlist = authctxt->authlist;
453: } else {
1.197 djm 454: free(authctxt->authlist);
1.51 markus 455: authctxt->authlist = authlist;
456: }
457: for (;;) {
458: Authmethod *method = authmethod_get(authlist);
459: if (method == NULL)
460: fatal("Permission denied (%s).", authlist);
461: authctxt->method = method;
1.119 markus 462:
463: /* reset the per method handler */
464: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
465: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
466:
467: /* and try new method */
1.51 markus 468: if (method->userauth(authctxt) != 0) {
469: debug2("we sent a %s packet, wait for reply", method->name);
470: break;
471: } else {
472: debug2("we did not send a packet, disable method");
473: method->enabled = NULL;
474: }
475: }
476: }
1.105 deraadt 477:
1.169 djm 478: /* ARGSUSED */
1.218 markus 479: int
1.92 markus 480: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 481: {
1.35 markus 482: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 483: "type %d", type);
1.218 markus 484: return 0;
1.35 markus 485: }
1.105 deraadt 486:
1.169 djm 487: /* ARGSUSED */
1.218 markus 488: int
1.92 markus 489: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 490: {
1.246 ! djm 491: char *msg, *lang;
1.166 djm 492: u_int len;
1.126 deraadt 493:
1.246 ! djm 494: debug3("%s", __func__);
! 495: msg = packet_get_string(&len);
1.35 markus 496: lang = packet_get_string(NULL);
1.246 ! djm 497: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
! 498: fmprintf(stderr, "%s", msg);
! 499: free(msg);
1.197 djm 500: free(lang);
1.218 markus 501: return 0;
1.20 markus 502: }
1.105 deraadt 503:
1.169 djm 504: /* ARGSUSED */
1.218 markus 505: int
1.92 markus 506: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 507: {
508: Authctxt *authctxt = ctxt;
1.172 djm 509:
1.20 markus 510: if (authctxt == NULL)
511: fatal("input_userauth_success: no authentication context");
1.197 djm 512: free(authctxt->authlist);
513: authctxt->authlist = NULL;
1.172 djm 514: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
515: authctxt->method->cleanup(authctxt);
1.197 djm 516: free(authctxt->methoddata);
517: authctxt->methoddata = NULL;
1.20 markus 518: authctxt->success = 1; /* break out */
1.218 markus 519: return 0;
1.20 markus 520: }
1.105 deraadt 521:
1.218 markus 522: int
1.172 djm 523: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
524: {
525: Authctxt *authctxt = ctxt;
526:
527: if (authctxt == NULL)
528: fatal("%s: no authentication context", __func__);
529:
530: fatal("Unexpected authentication success during %s.",
531: authctxt->method->name);
1.218 markus 532: return 0;
1.172 djm 533: }
534:
1.169 djm 535: /* ARGSUSED */
1.218 markus 536: int
1.92 markus 537: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 538: {
539: Authctxt *authctxt = ctxt;
540: char *authlist = NULL;
541: int partial;
542:
543: if (authctxt == NULL)
544: fatal("input_userauth_failure: no authentication context");
545:
1.23 markus 546: authlist = packet_get_string(NULL);
1.20 markus 547: partial = packet_get_char();
1.90 markus 548: packet_check_eom();
1.20 markus 549:
1.193 markus 550: if (partial != 0) {
1.116 itojun 551: logit("Authenticated with partial success.");
1.193 markus 552: /* reset state */
553: pubkey_cleanup(authctxt);
554: pubkey_prepare(authctxt);
555: }
1.109 markus 556: debug("Authentications that can continue: %s", authlist);
1.20 markus 557:
1.51 markus 558: userauth(authctxt, authlist);
1.218 markus 559: return 0;
1.51 markus 560: }
1.169 djm 561:
562: /* ARGSUSED */
1.218 markus 563: int
1.92 markus 564: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 565: {
566: Authctxt *authctxt = ctxt;
567: Key *key = NULL;
1.117 markus 568: Identity *id = NULL;
1.51 markus 569: Buffer b;
1.96 markus 570: int pktype, sent = 0;
571: u_int alen, blen;
572: char *pkalg, *fp;
573: u_char *pkblob;
1.51 markus 574:
575: if (authctxt == NULL)
576: fatal("input_userauth_pk_ok: no authentication context");
577: if (datafellows & SSH_BUG_PKOK) {
578: /* this is similar to SSH_BUG_PKAUTH */
579: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
580: pkblob = packet_get_string(&blen);
581: buffer_init(&b);
582: buffer_append(&b, pkblob, blen);
583: pkalg = buffer_get_string(&b, &alen);
584: buffer_free(&b);
585: } else {
586: pkalg = packet_get_string(&alen);
587: pkblob = packet_get_string(&blen);
588: }
1.90 markus 589: packet_check_eom();
1.51 markus 590:
1.117 markus 591: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 592:
1.117 markus 593: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
594: debug("unknown pkalg %s", pkalg);
595: goto done;
596: }
597: if ((key = key_from_blob(pkblob, blen)) == NULL) {
598: debug("no key from blob. pkalg %s", pkalg);
599: goto done;
600: }
601: if (key->type != pktype) {
602: error("input_userauth_pk_ok: type mismatch "
603: "for decoded key (received %d, expected %d)",
604: key->type, pktype);
605: goto done;
606: }
1.222 djm 607: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
608: SSH_FP_DEFAULT)) == NULL)
609: goto done;
1.117 markus 610: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 611: free(fp);
1.117 markus 612:
1.127 markus 613: /*
614: * search keys in the reverse order, because last candidate has been
615: * moved to the end of the queue. this also avoids confusion by
616: * duplicate keys
617: */
1.136 henning 618: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 619: if (key_equal(key, id->key)) {
620: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 621: break;
622: }
1.117 markus 623: }
624: done:
1.51 markus 625: if (key != NULL)
626: key_free(key);
1.197 djm 627: free(pkalg);
628: free(pkblob);
1.51 markus 629:
1.106 deraadt 630: /* try another method if we did not send a packet */
1.51 markus 631: if (sent == 0)
632: userauth(authctxt, NULL);
1.218 markus 633: return 0;
1.20 markus 634: }
1.121 markus 635:
636: #ifdef GSSAPI
1.133 djm 637: int
1.121 markus 638: userauth_gssapi(Authctxt *authctxt)
639: {
640: Gssctxt *gssctxt = NULL;
1.128 avsm 641: static gss_OID_set gss_supported = NULL;
1.139 djm 642: static u_int mech = 0;
1.121 markus 643: OM_uint32 min;
644: int ok = 0;
645:
646: /* Try one GSSAPI method at a time, rather than sending them all at
647: * once. */
648:
1.128 avsm 649: if (gss_supported == NULL)
650: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 651:
652: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 653: while (mech < gss_supported->count && !ok) {
1.121 markus 654: /* My DER encoding requires length<128 */
1.128 avsm 655: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 656: ssh_gssapi_check_mechanism(&gssctxt,
657: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 658: ok = 1; /* Mechanism works */
659: } else {
660: mech++;
661: }
662: }
663:
1.161 djm 664: if (!ok)
1.139 djm 665: return 0;
1.121 markus 666:
667: authctxt->methoddata=(void *)gssctxt;
668:
669: packet_start(SSH2_MSG_USERAUTH_REQUEST);
670: packet_put_cstring(authctxt->server_user);
671: packet_put_cstring(authctxt->service);
672: packet_put_cstring(authctxt->method->name);
673:
674: packet_put_int(1);
675:
1.129 markus 676: packet_put_int((gss_supported->elements[mech].length) + 2);
677: packet_put_char(SSH_GSS_OIDTYPE);
678: packet_put_char(gss_supported->elements[mech].length);
679: packet_put_raw(gss_supported->elements[mech].elements,
680: gss_supported->elements[mech].length);
1.121 markus 681:
682: packet_send();
683:
684: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
685: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
686: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
687: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
688:
689: mech++; /* Move along to next candidate */
690:
691: return 1;
692: }
693:
1.130 markus 694: static OM_uint32
695: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
696: {
697: Authctxt *authctxt = ctxt;
698: Gssctxt *gssctxt = authctxt->methoddata;
699: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 700: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
701: gss_buffer_desc gssbuf;
1.132 markus 702: OM_uint32 status, ms, flags;
703: Buffer b;
1.133 djm 704:
1.130 markus 705: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 706: recv_tok, &send_tok, &flags);
1.130 markus 707:
708: if (send_tok.length > 0) {
709: if (GSS_ERROR(status))
710: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
711: else
712: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 713:
1.130 markus 714: packet_put_string(send_tok.value, send_tok.length);
715: packet_send();
716: gss_release_buffer(&ms, &send_tok);
717: }
1.133 djm 718:
1.130 markus 719: if (status == GSS_S_COMPLETE) {
1.132 markus 720: /* send either complete or MIC, depending on mechanism */
721: if (!(flags & GSS_C_INTEG_FLAG)) {
722: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
723: packet_send();
724: } else {
725: ssh_gssapi_buildmic(&b, authctxt->server_user,
726: authctxt->service, "gssapi-with-mic");
727:
728: gssbuf.value = buffer_ptr(&b);
729: gssbuf.length = buffer_len(&b);
1.133 djm 730:
1.132 markus 731: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 732:
1.132 markus 733: if (!GSS_ERROR(status)) {
734: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
735: packet_put_string(mic.value, mic.length);
1.133 djm 736:
1.132 markus 737: packet_send();
738: }
1.133 djm 739:
1.132 markus 740: buffer_free(&b);
741: gss_release_buffer(&ms, &mic);
1.133 djm 742: }
1.130 markus 743: }
1.133 djm 744:
1.130 markus 745: return status;
746: }
747:
1.169 djm 748: /* ARGSUSED */
1.220 djm 749: int
1.121 markus 750: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
751: {
752: Authctxt *authctxt = ctxt;
753: Gssctxt *gssctxt;
754: int oidlen;
755: char *oidv;
756:
757: if (authctxt == NULL)
758: fatal("input_gssapi_response: no authentication context");
759: gssctxt = authctxt->methoddata;
760:
761: /* Setup our OID */
762: oidv = packet_get_string(&oidlen);
763:
1.129 markus 764: if (oidlen <= 2 ||
765: oidv[0] != SSH_GSS_OIDTYPE ||
766: oidv[1] != oidlen - 2) {
1.197 djm 767: free(oidv);
1.129 markus 768: debug("Badly encoded mechanism OID received");
769: userauth(authctxt, NULL);
1.220 djm 770: return 0;
1.121 markus 771: }
1.129 markus 772:
773: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
774: fatal("Server returned different OID than expected");
1.121 markus 775:
776: packet_check_eom();
777:
1.197 djm 778: free(oidv);
1.121 markus 779:
1.130 markus 780: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 781: /* Start again with next method on list */
782: debug("Trying to start again");
783: userauth(authctxt, NULL);
1.220 djm 784: return 0;
1.121 markus 785: }
1.220 djm 786: return 0;
1.121 markus 787: }
788:
1.169 djm 789: /* ARGSUSED */
1.220 djm 790: int
1.121 markus 791: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
792: {
793: Authctxt *authctxt = ctxt;
794: gss_buffer_desc recv_tok;
1.130 markus 795: OM_uint32 status;
1.121 markus 796: u_int slen;
797:
798: if (authctxt == NULL)
799: fatal("input_gssapi_response: no authentication context");
800:
801: recv_tok.value = packet_get_string(&slen);
802: recv_tok.length = slen; /* safe typecast */
803:
804: packet_check_eom();
805:
1.130 markus 806: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 807:
1.197 djm 808: free(recv_tok.value);
1.121 markus 809:
810: if (GSS_ERROR(status)) {
811: /* Start again with the next method in the list */
812: userauth(authctxt, NULL);
1.220 djm 813: return 0;
1.121 markus 814: }
1.220 djm 815: return 0;
1.121 markus 816: }
817:
1.169 djm 818: /* ARGSUSED */
1.220 djm 819: int
1.121 markus 820: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
821: {
822: Authctxt *authctxt = ctxt;
823: Gssctxt *gssctxt;
824: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
825: gss_buffer_desc recv_tok;
1.194 djm 826: OM_uint32 ms;
1.123 deraadt 827: u_int len;
1.121 markus 828:
829: if (authctxt == NULL)
830: fatal("input_gssapi_response: no authentication context");
831: gssctxt = authctxt->methoddata;
832:
1.123 deraadt 833: recv_tok.value = packet_get_string(&len);
834: recv_tok.length = len;
1.121 markus 835:
836: packet_check_eom();
837:
838: /* Stick it into GSSAPI and see what it says */
1.194 djm 839: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 840: &recv_tok, &send_tok, NULL);
1.121 markus 841:
1.197 djm 842: free(recv_tok.value);
1.121 markus 843: gss_release_buffer(&ms, &send_tok);
844:
845: /* Server will be returning a failed packet after this one */
1.220 djm 846: return 0;
1.121 markus 847: }
848:
1.169 djm 849: /* ARGSUSED */
1.220 djm 850: int
1.121 markus 851: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
852: {
853: char *msg;
854: char *lang;
855:
1.194 djm 856: /* maj */(void)packet_get_int();
857: /* min */(void)packet_get_int();
1.121 markus 858: msg=packet_get_string(NULL);
859: lang=packet_get_string(NULL);
860:
861: packet_check_eom();
862:
1.143 stevesk 863: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 864: free(msg);
865: free(lang);
1.220 djm 866: return 0;
1.121 markus 867: }
868: #endif /* GSSAPI */
1.20 markus 869:
1.1 markus 870: int
1.23 markus 871: userauth_none(Authctxt *authctxt)
872: {
873: /* initial userauth request */
874: packet_start(SSH2_MSG_USERAUTH_REQUEST);
875: packet_put_cstring(authctxt->server_user);
876: packet_put_cstring(authctxt->service);
877: packet_put_cstring(authctxt->method->name);
878: packet_send();
879: return 1;
880: }
881:
882: int
1.20 markus 883: userauth_passwd(Authctxt *authctxt)
1.1 markus 884: {
1.6 markus 885: static int attempt = 0;
1.99 markus 886: char prompt[150];
1.1 markus 887: char *password;
1.175 dtucker 888: const char *host = options.host_key_alias ? options.host_key_alias :
889: authctxt->host;
1.6 markus 890:
1.13 todd 891: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 892: return 0;
1.13 todd 893:
1.87 deraadt 894: if (attempt != 1)
1.13 todd 895: error("Permission denied, please try again.");
1.1 markus 896:
1.43 itojun 897: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 898: authctxt->server_user, host);
1.1 markus 899: password = read_passphrase(prompt, 0);
900: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 901: packet_put_cstring(authctxt->server_user);
902: packet_put_cstring(authctxt->service);
1.23 markus 903: packet_put_cstring(authctxt->method->name);
1.1 markus 904: packet_put_char(0);
1.49 markus 905: packet_put_cstring(password);
1.204 djm 906: explicit_bzero(password, strlen(password));
1.197 djm 907: free(password);
1.85 markus 908: packet_add_padding(64);
1.1 markus 909: packet_send();
1.99 markus 910:
1.104 deraadt 911: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 912: &input_userauth_passwd_changereq);
913:
1.1 markus 914: return 1;
915: }
1.169 djm 916:
1.99 markus 917: /*
918: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
919: */
1.169 djm 920: /* ARGSUSED */
1.218 markus 921: int
1.153 djm 922: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 923: {
924: Authctxt *authctxt = ctxt;
925: char *info, *lang, *password = NULL, *retype = NULL;
926: char prompt[150];
1.175 dtucker 927: const char *host = options.host_key_alias ? options.host_key_alias :
928: authctxt->host;
1.99 markus 929:
930: debug2("input_userauth_passwd_changereq");
931:
932: if (authctxt == NULL)
933: fatal("input_userauth_passwd_changereq: "
934: "no authentication context");
935:
936: info = packet_get_string(NULL);
937: lang = packet_get_string(NULL);
938: if (strlen(info) > 0)
1.116 itojun 939: logit("%s", info);
1.197 djm 940: free(info);
941: free(lang);
1.99 markus 942: packet_start(SSH2_MSG_USERAUTH_REQUEST);
943: packet_put_cstring(authctxt->server_user);
944: packet_put_cstring(authctxt->service);
945: packet_put_cstring(authctxt->method->name);
946: packet_put_char(1); /* additional info */
1.104 deraadt 947: snprintf(prompt, sizeof(prompt),
1.99 markus 948: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 949: authctxt->server_user, host);
1.99 markus 950: password = read_passphrase(prompt, 0);
951: packet_put_cstring(password);
1.204 djm 952: explicit_bzero(password, strlen(password));
1.197 djm 953: free(password);
1.99 markus 954: password = NULL;
955: while (password == NULL) {
1.104 deraadt 956: snprintf(prompt, sizeof(prompt),
1.99 markus 957: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 958: authctxt->server_user, host);
1.99 markus 959: password = read_passphrase(prompt, RP_ALLOW_EOF);
960: if (password == NULL) {
961: /* bail out */
1.218 markus 962: return 0;
1.99 markus 963: }
1.104 deraadt 964: snprintf(prompt, sizeof(prompt),
1.99 markus 965: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 966: authctxt->server_user, host);
1.99 markus 967: retype = read_passphrase(prompt, 0);
968: if (strcmp(password, retype) != 0) {
1.204 djm 969: explicit_bzero(password, strlen(password));
1.197 djm 970: free(password);
1.116 itojun 971: logit("Mismatch; try again, EOF to quit.");
1.99 markus 972: password = NULL;
973: }
1.204 djm 974: explicit_bzero(retype, strlen(retype));
1.197 djm 975: free(retype);
1.99 markus 976: }
977: packet_put_cstring(password);
1.204 djm 978: explicit_bzero(password, strlen(password));
1.197 djm 979: free(password);
1.99 markus 980: packet_add_padding(64);
981: packet_send();
1.104 deraadt 982:
983: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 984: &input_userauth_passwd_changereq);
1.218 markus 985: return 0;
1.117 markus 986: }
987:
1.231 markus 988: static const char *
989: identity_sign_encode(struct identity *id)
990: {
991: struct ssh *ssh = active_state;
992:
993: if (id->key->type == KEY_RSA) {
994: switch (ssh->kex->rsa_sha2) {
995: case 256:
996: return "rsa-sha2-256";
997: case 512:
998: return "rsa-sha2-512";
999: }
1000: }
1001: return key_ssh_name(id->key);
1002: }
1003:
1.117 markus 1004: static int
1.214 djm 1005: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1006: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1007: {
1008: Key *prv;
1009: int ret;
1.231 markus 1010: const char *alg;
1011:
1012: alg = identity_sign_encode(id);
1.99 markus 1013:
1.117 markus 1014: /* the agent supports this key */
1.230 djm 1015: if (id->agent_fd != -1)
1.214 djm 1016: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.231 markus 1017: data, datalen, alg, compat);
1.214 djm 1018:
1.117 markus 1019: /*
1020: * we have already loaded the private key or
1021: * the private key is stored in external hardware
1022: */
1.209 djm 1023: if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
1.231 markus 1024: return (sshkey_sign(id->key, sigp, lenp, data, datalen, alg,
1.214 djm 1025: compat));
1.117 markus 1026: /* load the private key from the file */
1.229 jcs 1027: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1028: return SSH_ERR_KEY_NOT_FOUND;
1.231 markus 1029: ret = sshkey_sign(prv, sigp, lenp, data, datalen, alg, compat);
1.214 djm 1030: sshkey_free(prv);
1.117 markus 1031: return (ret);
1.51 markus 1032: }
1033:
1.76 itojun 1034: static int
1.117 markus 1035: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1036: {
1037: Buffer b;
1.227 djm 1038: Identity *private_id;
1.32 markus 1039: u_char *blob, *signature;
1.214 djm 1040: size_t slen;
1.227 djm 1041: u_int bloblen, skip = 0;
1042: int matched, ret = -1, have_sig = 1;
1.182 djm 1043: char *fp;
1.1 markus 1044:
1.222 djm 1045: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1046: SSH_FP_DEFAULT)) == NULL)
1047: return 0;
1.227 djm 1048: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1049: free(fp);
1.51 markus 1050:
1.117 markus 1051: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1052: /* we cannot handle this key */
1.30 markus 1053: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1054: return 0;
1055: }
1.1 markus 1056: /* data to be signed */
1057: buffer_init(&b);
1.26 markus 1058: if (datafellows & SSH_OLD_SESSIONID) {
1059: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1060: skip = session_id2_len;
1.26 markus 1061: } else {
1.14 markus 1062: buffer_put_string(&b, session_id2, session_id2_len);
1063: skip = buffer_len(&b);
1064: }
1.1 markus 1065: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1066: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1067: buffer_put_cstring(&b,
1.30 markus 1068: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1069: "ssh-userauth" :
1.20 markus 1070: authctxt->service);
1.30 markus 1071: if (datafellows & SSH_BUG_PKAUTH) {
1072: buffer_put_char(&b, have_sig);
1073: } else {
1074: buffer_put_cstring(&b, authctxt->method->name);
1075: buffer_put_char(&b, have_sig);
1.231 markus 1076: buffer_put_cstring(&b, identity_sign_encode(id));
1.30 markus 1077: }
1.1 markus 1078: buffer_put_string(&b, blob, bloblen);
1079:
1.227 djm 1080: /*
1081: * If the key is an certificate, try to find a matching private key
1082: * and use it to complete the signature.
1.241 djm 1083: * If no such private key exists, fall back to trying the certificate
1084: * key itself in case it has a private half already loaded.
1.227 djm 1085: */
1086: if (key_is_cert(id->key)) {
1087: matched = 0;
1088: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1089: if (sshkey_equal_public(id->key, private_id->key) &&
1090: id->key->type != private_id->key->type) {
1091: id = private_id;
1092: matched = 1;
1093: break;
1094: }
1095: }
1096: if (matched) {
1097: debug2("%s: using private key \"%s\"%s for "
1098: "certificate", __func__, id->filename,
1099: id->agent_fd != -1 ? " from agent" : "");
1100: } else {
1.240 djm 1101: debug("%s: no separate private key for certificate "
1.227 djm 1102: "\"%s\"", __func__, id->filename);
1103: }
1104: }
1105:
1.1 markus 1106: /* generate signature */
1.117 markus 1107: ret = identity_sign(id, &signature, &slen,
1.214 djm 1108: buffer_ptr(&b), buffer_len(&b), datafellows);
1109: if (ret != 0) {
1.239 djm 1110: if (ret != SSH_ERR_KEY_NOT_FOUND)
1111: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1112: free(blob);
1.17 markus 1113: buffer_free(&b);
1114: return 0;
1115: }
1.28 markus 1116: #ifdef DEBUG_PK
1.1 markus 1117: buffer_dump(&b);
1118: #endif
1.30 markus 1119: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1120: buffer_clear(&b);
1121: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1122: skip = session_id2_len;
1.10 markus 1123: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1124: buffer_put_cstring(&b, authctxt->server_user);
1125: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1126: buffer_put_cstring(&b, authctxt->method->name);
1127: buffer_put_char(&b, have_sig);
1.30 markus 1128: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1129: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1130: buffer_put_string(&b, blob, bloblen);
1131: }
1.197 djm 1132: free(blob);
1.51 markus 1133:
1.1 markus 1134: /* append signature */
1135: buffer_put_string(&b, signature, slen);
1.197 djm 1136: free(signature);
1.1 markus 1137:
1138: /* skip session id and packet type */
1.14 markus 1139: if (buffer_len(&b) < skip + 1)
1.20 markus 1140: fatal("userauth_pubkey: internal error");
1.14 markus 1141: buffer_consume(&b, skip + 1);
1.1 markus 1142:
1143: /* put remaining data from buffer into packet */
1144: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1145: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1146: buffer_free(&b);
1147: packet_send();
1.17 markus 1148:
1149: return 1;
1.16 markus 1150: }
1151:
1.76 itojun 1152: static int
1.117 markus 1153: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1154: {
1.51 markus 1155: u_char *blob;
1.97 markus 1156: u_int bloblen, have_sig = 0;
1.20 markus 1157:
1.51 markus 1158: debug3("send_pubkey_test");
1.16 markus 1159:
1.117 markus 1160: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1161: /* we cannot handle this key */
1162: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1163: return 0;
1164: }
1.51 markus 1165: /* register callback for USERAUTH_PK_OK message */
1166: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1167:
1168: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1169: packet_put_cstring(authctxt->server_user);
1170: packet_put_cstring(authctxt->service);
1171: packet_put_cstring(authctxt->method->name);
1172: packet_put_char(have_sig);
1173: if (!(datafellows & SSH_BUG_PKAUTH))
1.231 markus 1174: packet_put_cstring(identity_sign_encode(id));
1.51 markus 1175: packet_put_string(blob, bloblen);
1.197 djm 1176: free(blob);
1.51 markus 1177: packet_send();
1178: return 1;
1179: }
1180:
1.76 itojun 1181: static Key *
1.229 jcs 1182: load_identity_file(Identity *id)
1.51 markus 1183: {
1.238 jsg 1184: Key *private = NULL;
1.229 jcs 1185: char prompt[300], *passphrase, *comment;
1.215 djm 1186: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1187: struct stat st;
1.16 markus 1188:
1.229 jcs 1189: if (stat(id->filename, &st) < 0) {
1190: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1191: id->filename, strerror(errno));
1.52 markus 1192: return NULL;
1193: }
1.214 djm 1194: snprintf(prompt, sizeof prompt,
1.229 jcs 1195: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1196: for (i = 0; i <= options.number_of_password_prompts; i++) {
1197: if (i == 0)
1198: passphrase = "";
1199: else {
1.20 markus 1200: passphrase = read_passphrase(prompt, 0);
1.214 djm 1201: if (*passphrase == '\0') {
1.20 markus 1202: debug2("no passphrase given, try next key");
1.214 djm 1203: free(passphrase);
1204: break;
1205: }
1206: }
1.229 jcs 1207: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1208: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1209: case 0:
1210: break;
1211: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1212: if (options.batch_mode) {
1213: quit = 1;
1214: break;
1215: }
1.215 djm 1216: if (i != 0)
1217: debug2("bad passphrase given, try again...");
1.214 djm 1218: break;
1219: case SSH_ERR_SYSTEM_ERROR:
1220: if (errno == ENOENT) {
1221: debug2("Load key \"%s\": %s",
1.229 jcs 1222: id->filename, ssh_err(r));
1.51 markus 1223: quit = 1;
1.214 djm 1224: break;
1.20 markus 1225: }
1.214 djm 1226: /* FALLTHROUGH */
1227: default:
1.229 jcs 1228: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1229: quit = 1;
1230: break;
1231: }
1.230 djm 1232: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1233: !(id->key && id->isprivate))
1234: maybe_add_key_to_agent(id->filename, private, comment,
1235: passphrase);
1.214 djm 1236: if (i > 0) {
1.204 djm 1237: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1238: free(passphrase);
1.16 markus 1239: }
1.232 mmcc 1240: free(comment);
1.214 djm 1241: if (private != NULL || quit)
1242: break;
1.16 markus 1243: }
1.51 markus 1244: return private;
1245: }
1246:
1.117 markus 1247: /*
1248: * try keys in the following order:
1.227 djm 1249: * 1. certificates listed in the config file
1250: * 2. other input certificates
1251: * 3. agent keys that are found in the config file
1252: * 4. other agent keys
1253: * 5. keys that are only listed in the config file
1.117 markus 1254: */
1255: static void
1256: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1257: {
1.214 djm 1258: struct identity *id, *id2, *tmp;
1259: struct idlist agent, files, *preferred;
1260: struct sshkey *key;
1.230 djm 1261: int agent_fd = -1, i, r, found;
1.214 djm 1262: size_t j;
1263: struct ssh_identitylist *idlist;
1.51 markus 1264:
1.117 markus 1265: TAILQ_INIT(&agent); /* keys from the agent */
1266: TAILQ_INIT(&files); /* keys from the config file */
1267: preferred = &authctxt->keys;
1268: TAILQ_INIT(preferred); /* preferred order of keys */
1269:
1.190 djm 1270: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1271: for (i = 0; i < options.num_identity_files; i++) {
1272: key = options.identity_keys[i];
1273: if (key && key->type == KEY_RSA1)
1.180 djm 1274: continue;
1275: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1276: continue;
1277: options.identity_keys[i] = NULL;
1.150 djm 1278: id = xcalloc(1, sizeof(*id));
1.230 djm 1279: id->agent_fd = -1;
1.117 markus 1280: id->key = key;
1281: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1282: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1283: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1284: }
1.227 djm 1285: /* list of certificates specified by user */
1286: for (i = 0; i < options.num_certificate_files; i++) {
1287: key = options.certificates[i];
1288: if (!key_is_cert(key) || key->cert == NULL ||
1289: key->cert->type != SSH2_CERT_TYPE_USER)
1290: continue;
1291: id = xcalloc(1, sizeof(*id));
1.230 djm 1292: id->agent_fd = -1;
1.227 djm 1293: id->key = key;
1294: id->filename = xstrdup(options.certificate_files[i]);
1295: id->userprovided = options.certificate_file_userprovided[i];
1296: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1297: }
1298: /* list of keys supported by the agent */
1.214 djm 1299: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1300: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1301: debug("%s: ssh_get_authentication_socket: %s",
1302: __func__, ssh_err(r));
1303: } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1304: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1305: debug("%s: ssh_fetch_identitylist: %s",
1306: __func__, ssh_err(r));
1.237 markus 1307: close(agent_fd);
1.214 djm 1308: } else {
1309: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1310: found = 0;
1311: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1312: /*
1313: * agent keys from the config file are
1314: * preferred
1315: */
1316: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1317: TAILQ_REMOVE(&files, id, next);
1318: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1319: id->agent_fd = agent_fd;
1.117 markus 1320: found = 1;
1321: break;
1322: }
1323: }
1.135 markus 1324: if (!found && !options.identities_only) {
1.150 djm 1325: id = xcalloc(1, sizeof(*id));
1.214 djm 1326: /* XXX "steals" key/comment from idlist */
1327: id->key = idlist->keys[j];
1328: id->filename = idlist->comments[j];
1329: idlist->keys[j] = NULL;
1330: idlist->comments[j] = NULL;
1331: id->agent_fd = agent_fd;
1.117 markus 1332: TAILQ_INSERT_TAIL(&agent, id, next);
1333: }
1334: }
1.214 djm 1335: ssh_free_identitylist(idlist);
1.117 markus 1336: /* append remaining agent keys */
1337: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1338: TAILQ_REMOVE(&agent, id, next);
1339: TAILQ_INSERT_TAIL(preferred, id, next);
1340: }
1.214 djm 1341: authctxt->agent_fd = agent_fd;
1.244 djm 1342: }
1343: /* Prefer PKCS11 keys that are explicitly listed */
1344: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1345: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1346: continue;
1347: found = 0;
1348: TAILQ_FOREACH(id2, &files, next) {
1349: if (id2->key == NULL ||
1350: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1351: continue;
1352: if (sshkey_equal(id->key, id2->key)) {
1353: TAILQ_REMOVE(&files, id, next);
1354: TAILQ_INSERT_TAIL(preferred, id, next);
1355: found = 1;
1356: break;
1357: }
1358: }
1359: /* If IdentitiesOnly set and key not found then don't use it */
1360: if (!found && options.identities_only) {
1361: TAILQ_REMOVE(&files, id, next);
1362: explicit_bzero(id, sizeof(*id));
1363: free(id);
1364: }
1.117 markus 1365: }
1366: /* append remaining keys from the config file */
1367: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1368: TAILQ_REMOVE(&files, id, next);
1369: TAILQ_INSERT_TAIL(preferred, id, next);
1370: }
1.228 djm 1371: /* finally, filter by PubkeyAcceptedKeyTypes */
1372: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1373: if (id->key != NULL &&
1374: match_pattern_list(sshkey_ssh_name(id->key),
1375: options.pubkey_key_types, 0) != 1) {
1376: debug("Skipping %s key %s - "
1377: "not in PubkeyAcceptedKeyTypes",
1378: sshkey_ssh_name(id->key), id->filename);
1379: TAILQ_REMOVE(preferred, id, next);
1380: sshkey_free(id->key);
1381: free(id->filename);
1382: memset(id, 0, sizeof(*id));
1383: continue;
1384: }
1.230 djm 1385: debug2("key: %s (%p)%s%s", id->filename, id->key,
1386: id->userprovided ? ", explicit" : "",
1387: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1388: }
1.17 markus 1389: }
1390:
1.117 markus 1391: static void
1392: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1393: {
1.117 markus 1394: Identity *id;
1.51 markus 1395:
1.214 djm 1396: if (authctxt->agent_fd != -1)
1397: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1398: for (id = TAILQ_FIRST(&authctxt->keys); id;
1399: id = TAILQ_FIRST(&authctxt->keys)) {
1400: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1401: sshkey_free(id->key);
1.197 djm 1402: free(id->filename);
1403: free(id);
1.117 markus 1404: }
1.1 markus 1405: }
1406:
1.225 markus 1407: static int
1408: try_identity(Identity *id)
1409: {
1410: if (!id->key)
1411: return (0);
1412: if (key_type_plain(id->key->type) == KEY_RSA &&
1413: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1414: debug("Skipped %s key %s for RSA/MD5 server",
1415: key_type(id->key), id->filename);
1416: return (0);
1417: }
1418: return (id->key->type != KEY_RSA1);
1419: }
1420:
1.20 markus 1421: int
1422: userauth_pubkey(Authctxt *authctxt)
1423: {
1.117 markus 1424: Identity *id;
1.20 markus 1425: int sent = 0;
1426:
1.117 markus 1427: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1428: if (id->tried++)
1429: return (0);
1.127 markus 1430: /* move key to the end of the queue */
1.117 markus 1431: TAILQ_REMOVE(&authctxt->keys, id, next);
1432: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1433: /*
1434: * send a test message if we have the public key. for
1435: * encrypted keys we cannot do this and have to load the
1436: * private key instead
1437: */
1.200 djm 1438: if (id->key != NULL) {
1.225 markus 1439: if (try_identity(id)) {
1.200 djm 1440: debug("Offering %s public key: %s",
1441: key_type(id->key), id->filename);
1442: sent = send_pubkey_test(authctxt, id);
1443: }
1444: } else {
1.117 markus 1445: debug("Trying private key: %s", id->filename);
1.229 jcs 1446: id->key = load_identity_file(id);
1.117 markus 1447: if (id->key != NULL) {
1.225 markus 1448: if (try_identity(id)) {
1449: id->isprivate = 1;
1.200 djm 1450: sent = sign_and_send_pubkey(
1451: authctxt, id);
1452: }
1.117 markus 1453: key_free(id->key);
1454: id->key = NULL;
1.51 markus 1455: }
1456: }
1.117 markus 1457: if (sent)
1458: return (sent);
1.28 markus 1459: }
1.117 markus 1460: return (0);
1.20 markus 1461: }
1462:
1.23 markus 1463: /*
1464: * Send userauth request message specifying keyboard-interactive method.
1465: */
1466: int
1467: userauth_kbdint(Authctxt *authctxt)
1468: {
1469: static int attempt = 0;
1470:
1471: if (attempt++ >= options.number_of_password_prompts)
1472: return 0;
1.82 markus 1473: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1474: if (attempt > 1 && !authctxt->info_req_seen) {
1475: debug3("userauth_kbdint: disable: no info_req_seen");
1476: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1477: return 0;
1478: }
1.23 markus 1479:
1480: debug2("userauth_kbdint");
1481: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1482: packet_put_cstring(authctxt->server_user);
1483: packet_put_cstring(authctxt->service);
1484: packet_put_cstring(authctxt->method->name);
1485: packet_put_cstring(""); /* lang */
1486: packet_put_cstring(options.kbd_interactive_devices ?
1487: options.kbd_interactive_devices : "");
1488: packet_send();
1489:
1490: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1491: return 1;
1492: }
1493:
1494: /*
1.46 markus 1495: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1496: */
1.218 markus 1497: int
1.92 markus 1498: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1499: {
1500: Authctxt *authctxt = ctxt;
1.46 markus 1501: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1502: u_int num_prompts, i;
1.23 markus 1503: int echo = 0;
1504:
1505: debug2("input_userauth_info_req");
1506:
1507: if (authctxt == NULL)
1508: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1509:
1510: authctxt->info_req_seen = 1;
1.23 markus 1511:
1512: name = packet_get_string(NULL);
1513: inst = packet_get_string(NULL);
1514: lang = packet_get_string(NULL);
1515: if (strlen(name) > 0)
1.116 itojun 1516: logit("%s", name);
1.23 markus 1517: if (strlen(inst) > 0)
1.116 itojun 1518: logit("%s", inst);
1.197 djm 1519: free(name);
1520: free(inst);
1521: free(lang);
1.23 markus 1522:
1523: num_prompts = packet_get_int();
1524: /*
1525: * Begin to build info response packet based on prompts requested.
1526: * We commit to providing the correct number of responses, so if
1527: * further on we run into a problem that prevents this, we have to
1528: * be sure and clean this up and send a correct error response.
1529: */
1530: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1531: packet_put_int(num_prompts);
1532:
1.73 markus 1533: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1534: for (i = 0; i < num_prompts; i++) {
1535: prompt = packet_get_string(NULL);
1536: echo = packet_get_char();
1537:
1.77 markus 1538: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1539:
1.49 markus 1540: packet_put_cstring(response);
1.204 djm 1541: explicit_bzero(response, strlen(response));
1.197 djm 1542: free(response);
1543: free(prompt);
1.23 markus 1544: }
1.90 markus 1545: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1546:
1.85 markus 1547: packet_add_padding(64);
1.23 markus 1548: packet_send();
1.218 markus 1549: return 0;
1.68 markus 1550: }
1551:
1.100 markus 1552: static int
1.223 djm 1553: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1554: const u_char *data, size_t datalen)
1.100 markus 1555: {
1.223 djm 1556: struct sshbuf *b;
1.101 markus 1557: struct stat st;
1.100 markus 1558: pid_t pid;
1.223 djm 1559: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1560: u_char rversion = 0, version = 2;
1561: void (*osigchld)(int);
1.100 markus 1562:
1.223 djm 1563: *sigp = NULL;
1564: *lenp = 0;
1.100 markus 1565:
1.101 markus 1566: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1567: error("%s: not installed: %s", __func__, strerror(errno));
1568: return -1;
1569: }
1570: if (fflush(stdout) != 0) {
1571: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1572: return -1;
1573: }
1.100 markus 1574: if (pipe(to) < 0) {
1.223 djm 1575: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1576: return -1;
1577: }
1578: if (pipe(from) < 0) {
1.223 djm 1579: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1580: return -1;
1581: }
1582: if ((pid = fork()) < 0) {
1.223 djm 1583: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1584: return -1;
1585: }
1.223 djm 1586: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1587: if (pid == 0) {
1.174 dtucker 1588: /* keep the socket on exec */
1.223 djm 1589: fcntl(sock, F_SETFD, 0);
1.155 markus 1590: permanently_drop_suid(getuid());
1.100 markus 1591: close(from[0]);
1592: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1593: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1594: close(to[1]);
1595: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1596: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1597: close(from[1]);
1598: close(to[0]);
1.223 djm 1599: /* Close everything but stdio and the socket */
1600: for (i = STDERR_FILENO + 1; i < sock; i++)
1601: close(i);
1602: closefrom(sock + 1);
1603: debug3("%s: [child] pid=%ld, exec %s",
1604: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1605: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1606: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1607: strerror(errno));
1608: }
1609: close(from[1]);
1610: close(to[0]);
1611:
1.223 djm 1612: if ((b = sshbuf_new()) == NULL)
1613: fatal("%s: sshbuf_new failed", __func__);
1614: /* send # of sock, data to be signed */
1615: if ((r = sshbuf_put_u32(b, sock) != 0) ||
1616: (r = sshbuf_put_string(b, data, datalen)) != 0)
1617: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1618: if (ssh_msg_send(to[1], version, b) == -1)
1619: fatal("%s: couldn't send request", __func__);
1620: sshbuf_reset(b);
1621: r = ssh_msg_recv(from[0], b);
1.101 markus 1622: close(from[0]);
1623: close(to[1]);
1.223 djm 1624: if (r < 0) {
1625: error("%s: no reply", __func__);
1626: goto fail;
1627: }
1.101 markus 1628:
1.223 djm 1629: errno = 0;
1630: while (waitpid(pid, &status, 0) < 0) {
1631: if (errno != EINTR) {
1632: error("%s: waitpid %ld: %s",
1633: __func__, (long)pid, strerror(errno));
1634: goto fail;
1635: }
1636: }
1637: if (!WIFEXITED(status)) {
1638: error("%s: exited abnormally", __func__);
1639: goto fail;
1640: }
1641: if (WEXITSTATUS(status) != 0) {
1642: error("%s: exited with status %d",
1643: __func__, WEXITSTATUS(status));
1644: goto fail;
1645: }
1646: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1647: error("%s: buffer error: %s", __func__, ssh_err(r));
1648: goto fail;
1649: }
1650: if (rversion != version) {
1651: error("%s: bad version", __func__);
1652: goto fail;
1653: }
1654: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1655: error("%s: buffer error: %s", __func__, ssh_err(r));
1656: fail:
1657: signal(SIGCHLD, osigchld);
1658: sshbuf_free(b);
1.100 markus 1659: return -1;
1660: }
1.223 djm 1661: signal(SIGCHLD, osigchld);
1662: sshbuf_free(b);
1.100 markus 1663:
1664: return 0;
1665: }
1666:
1.68 markus 1667: int
1668: userauth_hostbased(Authctxt *authctxt)
1669: {
1.223 djm 1670: struct ssh *ssh = active_state;
1671: struct sshkey *private = NULL;
1672: struct sshbuf *b = NULL;
1.72 markus 1673: const char *service;
1.223 djm 1674: u_char *sig = NULL, *keyblob = NULL;
1675: char *fp = NULL, *chost = NULL, *lname = NULL;
1676: size_t siglen = 0, keylen = 0;
1677: int i, r, success = 0;
1678:
1679: if (authctxt->ktypes == NULL) {
1680: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1681: authctxt->ktypes = authctxt->oktypes;
1682: }
1.213 djm 1683:
1.223 djm 1684: /*
1685: * Work through each listed type pattern in HostbasedKeyTypes,
1686: * trying each hostkey that matches the type in turn.
1687: */
1688: for (;;) {
1689: if (authctxt->active_ktype == NULL)
1690: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1691: if (authctxt->active_ktype == NULL ||
1692: *authctxt->active_ktype == '\0')
1693: break;
1694: debug3("%s: trying key type %s", __func__,
1695: authctxt->active_ktype);
1.68 markus 1696:
1.223 djm 1697: /* check for a useful key */
1698: private = NULL;
1699: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1700: if (authctxt->sensitive->keys[i] == NULL ||
1701: authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
1702: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1703: continue;
1704: if (match_pattern_list(
1705: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1706: authctxt->active_ktype, 0) != 1)
1.223 djm 1707: continue;
1.68 markus 1708: /* we take and free the key */
1.223 djm 1709: private = authctxt->sensitive->keys[i];
1710: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1711: break;
1712: }
1.223 djm 1713: /* Found one */
1714: if (private != NULL)
1715: break;
1716: /* No more keys of this type; advance */
1717: authctxt->active_ktype = NULL;
1.68 markus 1718: }
1.223 djm 1719: if (private == NULL) {
1720: free(authctxt->oktypes);
1721: authctxt->oktypes = authctxt->ktypes = NULL;
1722: authctxt->active_ktype = NULL;
1.109 markus 1723: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1724: goto out;
1.68 markus 1725: }
1.211 djm 1726:
1.223 djm 1727: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1728: SSH_FP_DEFAULT)) == NULL) {
1729: error("%s: sshkey_fingerprint failed", __func__);
1730: goto out;
1.68 markus 1731: }
1.223 djm 1732: debug("%s: trying hostkey %s %s",
1733: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1734:
1.84 markus 1735: /* figure out a name for the client host */
1.223 djm 1736: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1737: error("%s: cannot get local ipaddr/name", __func__);
1738: goto out;
1.84 markus 1739: }
1.223 djm 1740:
1741: /* XXX sshbuf_put_stringf? */
1742: xasprintf(&chost, "%s.", lname);
1743: debug2("%s: chost %s", __func__, chost);
1.84 markus 1744:
1.72 markus 1745: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1746: authctxt->service;
1.223 djm 1747:
1.68 markus 1748: /* construct data */
1.223 djm 1749: if ((b = sshbuf_new()) == NULL) {
1750: error("%s: sshbuf_new failed", __func__);
1751: goto out;
1752: }
1753: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1754: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1755: goto out;
1756: }
1757: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1758: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1759: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1760: (r = sshbuf_put_cstring(b, service)) != 0 ||
1761: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1762: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1763: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1764: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1765: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1766: error("%s: buffer error: %s", __func__, ssh_err(r));
1767: goto out;
1768: }
1769:
1.68 markus 1770: #ifdef DEBUG_PK
1.223 djm 1771: sshbuf_dump(b, stderr);
1.68 markus 1772: #endif
1.223 djm 1773: if (authctxt->sensitive->external_keysign)
1774: r = ssh_keysign(private, &sig, &siglen,
1775: sshbuf_ptr(b), sshbuf_len(b));
1776: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1777: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1778: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1779: if (r != 0) {
1780: error("sign using hostkey %s %s failed",
1781: sshkey_ssh_name(private), fp);
1782: goto out;
1783: }
1784: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1785: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1786: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1787: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1788: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1789: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1790: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1791: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1792: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1793: (r = sshpkt_send(ssh)) != 0) {
1794: error("%s: packet error: %s", __func__, ssh_err(r));
1795: goto out;
1796: }
1797: success = 1;
1798:
1799: out:
1800: if (sig != NULL) {
1801: explicit_bzero(sig, siglen);
1802: free(sig);
1.68 markus 1803: }
1.223 djm 1804: free(keyblob);
1805: free(lname);
1806: free(fp);
1.197 djm 1807: free(chost);
1.223 djm 1808: sshkey_free(private);
1809: sshbuf_free(b);
1.68 markus 1810:
1.223 djm 1811: return success;
1.23 markus 1812: }
1.170 djm 1813:
1.20 markus 1814: /* find auth method */
1815:
1816: /*
1817: * given auth method name, if configurable options permit this method fill
1818: * in auth_ident field and return true, otherwise return false.
1819: */
1.76 itojun 1820: static int
1.20 markus 1821: authmethod_is_enabled(Authmethod *method)
1822: {
1823: if (method == NULL)
1824: return 0;
1825: /* return false if options indicate this method is disabled */
1826: if (method->enabled == NULL || *method->enabled == 0)
1827: return 0;
1828: /* return false if batch mode is enabled but method needs interactive mode */
1829: if (method->batch_flag != NULL && *method->batch_flag != 0)
1830: return 0;
1831: return 1;
1832: }
1833:
1.76 itojun 1834: static Authmethod *
1.20 markus 1835: authmethod_lookup(const char *name)
1.1 markus 1836: {
1.20 markus 1837: Authmethod *method = NULL;
1838: if (name != NULL)
1839: for (method = authmethods; method->name != NULL; method++)
1840: if (strcmp(name, method->name) == 0)
1841: return method;
1842: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1843: return NULL;
1844: }
1.1 markus 1845:
1.53 markus 1846: /* XXX internal state */
1847: static Authmethod *current = NULL;
1848: static char *supported = NULL;
1849: static char *preferred = NULL;
1.105 deraadt 1850:
1.20 markus 1851: /*
1852: * Given the authentication method list sent by the server, return the
1853: * next method we should try. If the server initially sends a nil list,
1.67 markus 1854: * use a built-in default list.
1.41 stevesk 1855: */
1.76 itojun 1856: static Authmethod *
1.20 markus 1857: authmethod_get(char *authlist)
1858: {
1.53 markus 1859: char *name = NULL;
1.97 markus 1860: u_int next;
1.41 stevesk 1861:
1.20 markus 1862: /* Use a suitable default if we're passed a nil list. */
1863: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1864: authlist = options.preferred_authentications;
1.20 markus 1865:
1.53 markus 1866: if (supported == NULL || strcmp(authlist, supported) != 0) {
1867: debug3("start over, passed a different list %s", authlist);
1.197 djm 1868: free(supported);
1.53 markus 1869: supported = xstrdup(authlist);
1870: preferred = options.preferred_authentications;
1871: debug3("preferred %s", preferred);
1872: current = NULL;
1873: } else if (current != NULL && authmethod_is_enabled(current))
1874: return current;
1.20 markus 1875:
1.53 markus 1876: for (;;) {
1877: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1878: debug("No more authentication methods to try.");
1.53 markus 1879: current = NULL;
1880: return NULL;
1881: }
1882: preferred += next;
1.23 markus 1883: debug3("authmethod_lookup %s", name);
1.53 markus 1884: debug3("remaining preferred: %s", preferred);
1885: if ((current = authmethod_lookup(name)) != NULL &&
1886: authmethod_is_enabled(current)) {
1.23 markus 1887: debug3("authmethod_is_enabled %s", name);
1.109 markus 1888: debug("Next authentication method: %s", name);
1.197 djm 1889: free(name);
1.53 markus 1890: return current;
1.23 markus 1891: }
1.198 dtucker 1892: free(name);
1.1 markus 1893: }
1.53 markus 1894: }
1.1 markus 1895:
1.79 stevesk 1896: static char *
1.53 markus 1897: authmethods_get(void)
1898: {
1899: Authmethod *method = NULL;
1.93 markus 1900: Buffer b;
1901: char *list;
1.27 provos 1902:
1.93 markus 1903: buffer_init(&b);
1.53 markus 1904: for (method = authmethods; method->name != NULL; method++) {
1905: if (authmethod_is_enabled(method)) {
1.93 markus 1906: if (buffer_len(&b) > 0)
1907: buffer_append(&b, ",", 1);
1908: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1909: }
1910: }
1.242 djm 1911: if ((list = sshbuf_dup_string(&b)) == NULL)
1912: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1913: buffer_free(&b);
1914: return list;
1.1 markus 1915: }
1.170 djm 1916:
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