Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.259
1.259 ! markus 1: /* $OpenBSD: sshconnect2.c,v 1.258 2017/05/05 10:42:49 naddy 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
1.259 ! markus 90: verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
1.61 markus 91: {
1.75 markus 92: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 93: fatal("Host key verification failed.");
1.61 markus 94: return 0;
95: }
96:
1.186 djm 97: static char *
98: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
99: {
100: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
101: size_t maxlen;
102: struct hostkeys *hostkeys;
103: int ktype;
1.188 djm 104: u_int i;
1.186 djm 105:
106: /* Find all hostkeys for this hostname */
107: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
108: hostkeys = init_hostkeys();
1.188 djm 109: for (i = 0; i < options.num_user_hostfiles; i++)
110: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
111: for (i = 0; i < options.num_system_hostfiles; i++)
112: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 113:
114: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
115: maxlen = strlen(avail) + 1;
116: first = xmalloc(maxlen);
117: last = xmalloc(maxlen);
118: *first = *last = '\0';
119:
120: #define ALG_APPEND(to, from) \
121: do { \
122: if (*to != '\0') \
123: strlcat(to, ",", maxlen); \
124: strlcat(to, from, maxlen); \
125: } while (0)
126:
127: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 128: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 129: fatal("%s: unknown alg %s", __func__, alg);
130: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 131: sshkey_type_plain(ktype), NULL))
1.186 djm 132: ALG_APPEND(first, alg);
133: else
134: ALG_APPEND(last, alg);
135: }
136: #undef ALG_APPEND
1.216 djm 137: xasprintf(&ret, "%s%s%s", first,
138: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 139: if (*first != '\0')
140: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
141:
1.197 djm 142: free(first);
143: free(last);
144: free(hostname);
145: free(oavail);
1.186 djm 146: free_hostkeys(hostkeys);
147:
148: return ret;
149: }
150:
1.1 markus 151: void
1.186 djm 152: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 153: {
1.205 markus 154: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.231 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 ?
1.250 djm 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)
1.254 dtucker 190: packet_set_rekey_limits(options.rekey_limit,
191: 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 *);
1.251 djm 313: static void pubkey_reset(Authctxt *);
1.259 ! markus 314: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 315:
316: static Authmethod *authmethod_get(char *authlist);
317: static Authmethod *authmethod_lookup(const char *name);
318: static char *authmethods_get(void);
1.20 markus 319:
320: Authmethod authmethods[] = {
1.121 markus 321: #ifdef GSSAPI
1.132 markus 322: {"gssapi-with-mic",
1.121 markus 323: userauth_gssapi,
1.170 djm 324: NULL,
1.121 markus 325: &options.gss_authentication,
326: NULL},
327: #endif
1.81 markus 328: {"hostbased",
329: userauth_hostbased,
1.170 djm 330: NULL,
1.81 markus 331: &options.hostbased_authentication,
332: NULL},
1.20 markus 333: {"publickey",
334: userauth_pubkey,
1.170 djm 335: NULL,
1.28 markus 336: &options.pubkey_authentication,
1.20 markus 337: NULL},
1.81 markus 338: {"keyboard-interactive",
339: userauth_kbdint,
1.170 djm 340: NULL,
1.81 markus 341: &options.kbd_interactive_authentication,
342: &options.batch_mode},
1.20 markus 343: {"password",
344: userauth_passwd,
1.170 djm 345: NULL,
1.20 markus 346: &options.password_authentication,
1.23 markus 347: &options.batch_mode},
348: {"none",
349: userauth_none,
350: NULL,
1.170 djm 351: NULL,
1.23 markus 352: NULL},
1.170 djm 353: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 354: };
355:
356: void
1.68 markus 357: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 358: Sensitive *sensitive)
1.20 markus 359: {
1.231 markus 360: struct ssh *ssh = active_state;
1.20 markus 361: Authctxt authctxt;
1.231 markus 362: int r;
1.39 markus 363:
1.73 markus 364: if (options.challenge_response_authentication)
1.39 markus 365: options.kbd_interactive_authentication = 1;
1.53 markus 366: if (options.preferred_authentications == NULL)
367: options.preferred_authentications = authmethods_get();
368:
1.20 markus 369: /* setup authentication context */
1.82 markus 370: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 371: pubkey_prepare(&authctxt);
1.20 markus 372: authctxt.server_user = server_user;
1.68 markus 373: authctxt.local_user = local_user;
1.20 markus 374: authctxt.host = host;
375: authctxt.service = "ssh-connection"; /* service name */
376: authctxt.success = 0;
1.23 markus 377: authctxt.method = authmethod_lookup("none");
1.51 markus 378: authctxt.authlist = NULL;
1.121 markus 379: authctxt.methoddata = NULL;
1.100 markus 380: authctxt.sensitive = sensitive;
1.223 djm 381: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 382: authctxt.info_req_seen = 0;
1.215 djm 383: authctxt.agent_fd = -1;
1.23 markus 384: if (authctxt.method == NULL)
385: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 386:
1.231 markus 387: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
388: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
389: (r = sshpkt_send(ssh)) != 0)
390: fatal("%s: %s", __func__, ssh_err(r));
391:
392: ssh_dispatch_init(ssh, &input_userauth_error);
393: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
394: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
395: ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
1.20 markus 396:
1.117 markus 397: pubkey_cleanup(&authctxt);
1.231 markus 398: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 399:
1.248 dtucker 400: if (!authctxt.success)
401: fatal("Authentication failed.");
1.109 markus 402: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 403: }
1.119 markus 404:
1.231 markus 405: /* ARGSUSED */
406: int
407: input_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt)
408: {
409: Authctxt *authctxt = ctxt;
410: struct ssh *ssh = active_state;
411: int r;
412:
413: if (ssh_packet_remaining(ssh) > 0) {
414: char *reply;
415:
416: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
417: goto out;
418: debug2("service_accept: %s", reply);
419: free(reply);
420: } else {
421: debug2("buggy server: service_accept w/o service");
422: }
423: if ((r = sshpkt_get_end(ssh)) != 0)
424: goto out;
425: debug("SSH2_MSG_SERVICE_ACCEPT received");
426:
427: /* initial userauth request */
428: userauth_none(authctxt);
429:
430: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
431: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
432: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
433: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
434: r = 0;
435: out:
436: return r;
437: }
438:
439: /* ARGSUSED */
440: int
441: input_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt)
442: {
443: return kex_input_ext_info(type, seqnr, active_state);
444: }
445:
1.20 markus 446: void
1.51 markus 447: userauth(Authctxt *authctxt, char *authlist)
448: {
1.170 djm 449: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
450: authctxt->method->cleanup(authctxt);
451:
1.197 djm 452: free(authctxt->methoddata);
453: authctxt->methoddata = NULL;
1.51 markus 454: if (authlist == NULL) {
455: authlist = authctxt->authlist;
456: } else {
1.197 djm 457: free(authctxt->authlist);
1.51 markus 458: authctxt->authlist = authlist;
459: }
460: for (;;) {
461: Authmethod *method = authmethod_get(authlist);
462: if (method == NULL)
463: fatal("Permission denied (%s).", authlist);
464: authctxt->method = method;
1.119 markus 465:
466: /* reset the per method handler */
467: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
468: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
469:
470: /* and try new method */
1.51 markus 471: if (method->userauth(authctxt) != 0) {
472: debug2("we sent a %s packet, wait for reply", method->name);
473: break;
474: } else {
475: debug2("we did not send a packet, disable method");
476: method->enabled = NULL;
477: }
478: }
479: }
1.105 deraadt 480:
1.169 djm 481: /* ARGSUSED */
1.218 markus 482: int
1.92 markus 483: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 484: {
1.35 markus 485: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 486: "type %d", type);
1.218 markus 487: return 0;
1.35 markus 488: }
1.105 deraadt 489:
1.169 djm 490: /* ARGSUSED */
1.218 markus 491: int
1.92 markus 492: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 493: {
1.246 djm 494: char *msg, *lang;
1.166 djm 495: u_int len;
1.126 deraadt 496:
1.246 djm 497: debug3("%s", __func__);
498: msg = packet_get_string(&len);
1.35 markus 499: lang = packet_get_string(NULL);
1.246 djm 500: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
501: fmprintf(stderr, "%s", msg);
502: free(msg);
1.197 djm 503: free(lang);
1.218 markus 504: return 0;
1.20 markus 505: }
1.105 deraadt 506:
1.169 djm 507: /* ARGSUSED */
1.218 markus 508: int
1.92 markus 509: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 510: {
511: Authctxt *authctxt = ctxt;
1.172 djm 512:
1.20 markus 513: if (authctxt == NULL)
514: fatal("input_userauth_success: no authentication context");
1.197 djm 515: free(authctxt->authlist);
516: authctxt->authlist = NULL;
1.172 djm 517: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
518: authctxt->method->cleanup(authctxt);
1.197 djm 519: free(authctxt->methoddata);
520: authctxt->methoddata = NULL;
1.20 markus 521: authctxt->success = 1; /* break out */
1.218 markus 522: return 0;
1.20 markus 523: }
1.105 deraadt 524:
1.218 markus 525: int
1.172 djm 526: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
527: {
528: Authctxt *authctxt = ctxt;
529:
530: if (authctxt == NULL)
531: fatal("%s: no authentication context", __func__);
532:
533: fatal("Unexpected authentication success during %s.",
534: authctxt->method->name);
1.218 markus 535: return 0;
1.172 djm 536: }
537:
1.169 djm 538: /* ARGSUSED */
1.218 markus 539: int
1.92 markus 540: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 541: {
542: Authctxt *authctxt = ctxt;
543: char *authlist = NULL;
544: int partial;
545:
546: if (authctxt == NULL)
547: fatal("input_userauth_failure: no authentication context");
548:
1.23 markus 549: authlist = packet_get_string(NULL);
1.20 markus 550: partial = packet_get_char();
1.90 markus 551: packet_check_eom();
1.20 markus 552:
1.193 markus 553: if (partial != 0) {
1.247 dtucker 554: verbose("Authenticated with partial success.");
1.193 markus 555: /* reset state */
1.251 djm 556: pubkey_reset(authctxt);
1.193 markus 557: }
1.109 markus 558: debug("Authentications that can continue: %s", authlist);
1.20 markus 559:
1.51 markus 560: userauth(authctxt, authlist);
1.218 markus 561: return 0;
1.51 markus 562: }
1.169 djm 563:
564: /* ARGSUSED */
1.218 markus 565: int
1.92 markus 566: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 567: {
568: Authctxt *authctxt = ctxt;
1.259 ! markus 569: struct sshkey *key = NULL;
1.117 markus 570: Identity *id = NULL;
1.51 markus 571: Buffer b;
1.96 markus 572: int pktype, sent = 0;
573: u_int alen, blen;
574: char *pkalg, *fp;
575: u_char *pkblob;
1.51 markus 576:
577: if (authctxt == NULL)
578: fatal("input_userauth_pk_ok: no authentication context");
579: if (datafellows & SSH_BUG_PKOK) {
580: /* this is similar to SSH_BUG_PKAUTH */
581: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
582: pkblob = packet_get_string(&blen);
583: buffer_init(&b);
584: buffer_append(&b, pkblob, blen);
585: pkalg = buffer_get_string(&b, &alen);
586: buffer_free(&b);
587: } else {
588: pkalg = packet_get_string(&alen);
589: pkblob = packet_get_string(&blen);
590: }
1.90 markus 591: packet_check_eom();
1.51 markus 592:
1.117 markus 593: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 594:
1.117 markus 595: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
596: debug("unknown pkalg %s", pkalg);
597: goto done;
598: }
599: if ((key = key_from_blob(pkblob, blen)) == NULL) {
600: debug("no key from blob. pkalg %s", pkalg);
601: goto done;
602: }
603: if (key->type != pktype) {
604: error("input_userauth_pk_ok: type mismatch "
605: "for decoded key (received %d, expected %d)",
606: key->type, pktype);
607: goto done;
608: }
1.222 djm 609: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
610: SSH_FP_DEFAULT)) == NULL)
611: goto done;
1.117 markus 612: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 613: free(fp);
1.117 markus 614:
1.127 markus 615: /*
616: * search keys in the reverse order, because last candidate has been
617: * moved to the end of the queue. this also avoids confusion by
618: * duplicate keys
619: */
1.136 henning 620: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 621: if (key_equal(key, id->key)) {
622: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 623: break;
624: }
1.117 markus 625: }
626: done:
1.51 markus 627: if (key != NULL)
628: key_free(key);
1.197 djm 629: free(pkalg);
630: free(pkblob);
1.51 markus 631:
1.106 deraadt 632: /* try another method if we did not send a packet */
1.51 markus 633: if (sent == 0)
634: userauth(authctxt, NULL);
1.218 markus 635: return 0;
1.20 markus 636: }
1.121 markus 637:
638: #ifdef GSSAPI
1.133 djm 639: int
1.121 markus 640: userauth_gssapi(Authctxt *authctxt)
641: {
642: Gssctxt *gssctxt = NULL;
1.128 avsm 643: static gss_OID_set gss_supported = NULL;
1.139 djm 644: static u_int mech = 0;
1.121 markus 645: OM_uint32 min;
646: int ok = 0;
647:
648: /* Try one GSSAPI method at a time, rather than sending them all at
649: * once. */
650:
1.128 avsm 651: if (gss_supported == NULL)
652: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 653:
654: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 655: while (mech < gss_supported->count && !ok) {
1.121 markus 656: /* My DER encoding requires length<128 */
1.128 avsm 657: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 658: ssh_gssapi_check_mechanism(&gssctxt,
659: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 660: ok = 1; /* Mechanism works */
661: } else {
662: mech++;
663: }
664: }
665:
1.161 djm 666: if (!ok)
1.139 djm 667: return 0;
1.121 markus 668:
669: authctxt->methoddata=(void *)gssctxt;
670:
671: packet_start(SSH2_MSG_USERAUTH_REQUEST);
672: packet_put_cstring(authctxt->server_user);
673: packet_put_cstring(authctxt->service);
674: packet_put_cstring(authctxt->method->name);
675:
676: packet_put_int(1);
677:
1.129 markus 678: packet_put_int((gss_supported->elements[mech].length) + 2);
679: packet_put_char(SSH_GSS_OIDTYPE);
680: packet_put_char(gss_supported->elements[mech].length);
681: packet_put_raw(gss_supported->elements[mech].elements,
682: gss_supported->elements[mech].length);
1.121 markus 683:
684: packet_send();
685:
686: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
687: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
688: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
689: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
690:
691: mech++; /* Move along to next candidate */
692:
693: return 1;
694: }
695:
1.130 markus 696: static OM_uint32
697: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
698: {
699: Authctxt *authctxt = ctxt;
700: Gssctxt *gssctxt = authctxt->methoddata;
701: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 702: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
703: gss_buffer_desc gssbuf;
1.132 markus 704: OM_uint32 status, ms, flags;
705: Buffer b;
1.133 djm 706:
1.130 markus 707: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 708: recv_tok, &send_tok, &flags);
1.130 markus 709:
710: if (send_tok.length > 0) {
711: if (GSS_ERROR(status))
712: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
713: else
714: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 715:
1.130 markus 716: packet_put_string(send_tok.value, send_tok.length);
717: packet_send();
718: gss_release_buffer(&ms, &send_tok);
719: }
1.133 djm 720:
1.130 markus 721: if (status == GSS_S_COMPLETE) {
1.132 markus 722: /* send either complete or MIC, depending on mechanism */
723: if (!(flags & GSS_C_INTEG_FLAG)) {
724: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
725: packet_send();
726: } else {
727: ssh_gssapi_buildmic(&b, authctxt->server_user,
728: authctxt->service, "gssapi-with-mic");
729:
730: gssbuf.value = buffer_ptr(&b);
731: gssbuf.length = buffer_len(&b);
1.133 djm 732:
1.132 markus 733: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 734:
1.132 markus 735: if (!GSS_ERROR(status)) {
736: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
737: packet_put_string(mic.value, mic.length);
1.133 djm 738:
1.132 markus 739: packet_send();
740: }
1.133 djm 741:
1.132 markus 742: buffer_free(&b);
743: gss_release_buffer(&ms, &mic);
1.133 djm 744: }
1.130 markus 745: }
1.133 djm 746:
1.130 markus 747: return status;
748: }
749:
1.169 djm 750: /* ARGSUSED */
1.220 djm 751: int
1.121 markus 752: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
753: {
754: Authctxt *authctxt = ctxt;
755: Gssctxt *gssctxt;
756: int oidlen;
757: char *oidv;
758:
759: if (authctxt == NULL)
760: fatal("input_gssapi_response: no authentication context");
761: gssctxt = authctxt->methoddata;
762:
763: /* Setup our OID */
764: oidv = packet_get_string(&oidlen);
765:
1.129 markus 766: if (oidlen <= 2 ||
767: oidv[0] != SSH_GSS_OIDTYPE ||
768: oidv[1] != oidlen - 2) {
1.197 djm 769: free(oidv);
1.129 markus 770: debug("Badly encoded mechanism OID received");
771: userauth(authctxt, NULL);
1.220 djm 772: return 0;
1.121 markus 773: }
1.129 markus 774:
775: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
776: fatal("Server returned different OID than expected");
1.121 markus 777:
778: packet_check_eom();
779:
1.197 djm 780: free(oidv);
1.121 markus 781:
1.130 markus 782: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 783: /* Start again with next method on list */
784: debug("Trying to start again");
785: userauth(authctxt, NULL);
1.220 djm 786: return 0;
1.121 markus 787: }
1.220 djm 788: return 0;
1.121 markus 789: }
790:
1.169 djm 791: /* ARGSUSED */
1.220 djm 792: int
1.121 markus 793: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
794: {
795: Authctxt *authctxt = ctxt;
796: gss_buffer_desc recv_tok;
1.130 markus 797: OM_uint32 status;
1.121 markus 798: u_int slen;
799:
800: if (authctxt == NULL)
801: fatal("input_gssapi_response: no authentication context");
802:
803: recv_tok.value = packet_get_string(&slen);
804: recv_tok.length = slen; /* safe typecast */
805:
806: packet_check_eom();
807:
1.130 markus 808: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 809:
1.197 djm 810: free(recv_tok.value);
1.121 markus 811:
812: if (GSS_ERROR(status)) {
813: /* Start again with the next method in the list */
814: userauth(authctxt, NULL);
1.220 djm 815: return 0;
1.121 markus 816: }
1.220 djm 817: return 0;
1.121 markus 818: }
819:
1.169 djm 820: /* ARGSUSED */
1.220 djm 821: int
1.121 markus 822: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
823: {
824: Authctxt *authctxt = ctxt;
825: Gssctxt *gssctxt;
826: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
827: gss_buffer_desc recv_tok;
1.194 djm 828: OM_uint32 ms;
1.123 deraadt 829: u_int len;
1.121 markus 830:
831: if (authctxt == NULL)
832: fatal("input_gssapi_response: no authentication context");
833: gssctxt = authctxt->methoddata;
834:
1.123 deraadt 835: recv_tok.value = packet_get_string(&len);
836: recv_tok.length = len;
1.121 markus 837:
838: packet_check_eom();
839:
840: /* Stick it into GSSAPI and see what it says */
1.194 djm 841: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 842: &recv_tok, &send_tok, NULL);
1.121 markus 843:
1.197 djm 844: free(recv_tok.value);
1.121 markus 845: gss_release_buffer(&ms, &send_tok);
846:
847: /* Server will be returning a failed packet after this one */
1.220 djm 848: return 0;
1.121 markus 849: }
850:
1.169 djm 851: /* ARGSUSED */
1.220 djm 852: int
1.121 markus 853: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
854: {
855: char *msg;
856: char *lang;
857:
1.194 djm 858: /* maj */(void)packet_get_int();
859: /* min */(void)packet_get_int();
1.121 markus 860: msg=packet_get_string(NULL);
861: lang=packet_get_string(NULL);
862:
863: packet_check_eom();
864:
1.143 stevesk 865: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 866: free(msg);
867: free(lang);
1.220 djm 868: return 0;
1.121 markus 869: }
870: #endif /* GSSAPI */
1.20 markus 871:
1.1 markus 872: int
1.23 markus 873: userauth_none(Authctxt *authctxt)
874: {
875: /* initial userauth request */
876: packet_start(SSH2_MSG_USERAUTH_REQUEST);
877: packet_put_cstring(authctxt->server_user);
878: packet_put_cstring(authctxt->service);
879: packet_put_cstring(authctxt->method->name);
880: packet_send();
881: return 1;
882: }
883:
884: int
1.20 markus 885: userauth_passwd(Authctxt *authctxt)
1.1 markus 886: {
1.6 markus 887: static int attempt = 0;
1.99 markus 888: char prompt[150];
1.1 markus 889: char *password;
1.175 dtucker 890: const char *host = options.host_key_alias ? options.host_key_alias :
891: authctxt->host;
1.6 markus 892:
1.13 todd 893: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 894: return 0;
1.13 todd 895:
1.87 deraadt 896: if (attempt != 1)
1.13 todd 897: error("Permission denied, please try again.");
1.1 markus 898:
1.43 itojun 899: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 900: authctxt->server_user, host);
1.1 markus 901: password = read_passphrase(prompt, 0);
902: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 903: packet_put_cstring(authctxt->server_user);
904: packet_put_cstring(authctxt->service);
1.23 markus 905: packet_put_cstring(authctxt->method->name);
1.1 markus 906: packet_put_char(0);
1.49 markus 907: packet_put_cstring(password);
1.204 djm 908: explicit_bzero(password, strlen(password));
1.197 djm 909: free(password);
1.85 markus 910: packet_add_padding(64);
1.1 markus 911: packet_send();
1.99 markus 912:
1.104 deraadt 913: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 914: &input_userauth_passwd_changereq);
915:
1.1 markus 916: return 1;
917: }
1.169 djm 918:
1.99 markus 919: /*
920: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
921: */
1.169 djm 922: /* ARGSUSED */
1.218 markus 923: int
1.153 djm 924: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 925: {
926: Authctxt *authctxt = ctxt;
927: char *info, *lang, *password = NULL, *retype = NULL;
928: char prompt[150];
1.252 djm 929: const char *host;
1.99 markus 930:
931: debug2("input_userauth_passwd_changereq");
932:
933: if (authctxt == NULL)
934: fatal("input_userauth_passwd_changereq: "
935: "no authentication context");
1.252 djm 936: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 937:
938: info = packet_get_string(NULL);
939: lang = packet_get_string(NULL);
940: if (strlen(info) > 0)
1.116 itojun 941: logit("%s", info);
1.197 djm 942: free(info);
943: free(lang);
1.99 markus 944: packet_start(SSH2_MSG_USERAUTH_REQUEST);
945: packet_put_cstring(authctxt->server_user);
946: packet_put_cstring(authctxt->service);
947: packet_put_cstring(authctxt->method->name);
948: packet_put_char(1); /* additional info */
1.104 deraadt 949: snprintf(prompt, sizeof(prompt),
1.99 markus 950: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 951: authctxt->server_user, host);
1.99 markus 952: password = read_passphrase(prompt, 0);
953: packet_put_cstring(password);
1.204 djm 954: explicit_bzero(password, strlen(password));
1.197 djm 955: free(password);
1.99 markus 956: password = NULL;
957: while (password == NULL) {
1.104 deraadt 958: snprintf(prompt, sizeof(prompt),
1.99 markus 959: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 960: authctxt->server_user, host);
1.99 markus 961: password = read_passphrase(prompt, RP_ALLOW_EOF);
962: if (password == NULL) {
963: /* bail out */
1.218 markus 964: return 0;
1.99 markus 965: }
1.104 deraadt 966: snprintf(prompt, sizeof(prompt),
1.99 markus 967: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 968: authctxt->server_user, host);
1.99 markus 969: retype = read_passphrase(prompt, 0);
970: if (strcmp(password, retype) != 0) {
1.204 djm 971: explicit_bzero(password, strlen(password));
1.197 djm 972: free(password);
1.116 itojun 973: logit("Mismatch; try again, EOF to quit.");
1.99 markus 974: password = NULL;
975: }
1.204 djm 976: explicit_bzero(retype, strlen(retype));
1.197 djm 977: free(retype);
1.99 markus 978: }
979: packet_put_cstring(password);
1.204 djm 980: explicit_bzero(password, strlen(password));
1.197 djm 981: free(password);
1.99 markus 982: packet_add_padding(64);
983: packet_send();
1.104 deraadt 984:
985: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 986: &input_userauth_passwd_changereq);
1.218 markus 987: return 0;
1.117 markus 988: }
989:
1.231 markus 990: static const char *
1.255 djm 991: key_sign_encode(const struct sshkey *key)
1.231 markus 992: {
993: struct ssh *ssh = active_state;
994:
1.255 djm 995: if (key->type == KEY_RSA) {
1.231 markus 996: switch (ssh->kex->rsa_sha2) {
997: case 256:
998: return "rsa-sha2-256";
999: case 512:
1000: return "rsa-sha2-512";
1001: }
1002: }
1.255 djm 1003: return key_ssh_name(key);
1.231 markus 1004: }
1005:
1.117 markus 1006: static int
1.214 djm 1007: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1008: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1009: {
1.259 ! markus 1010: struct sshkey *prv;
1.117 markus 1011: int ret;
1.99 markus 1012:
1.117 markus 1013: /* the agent supports this key */
1.255 djm 1014: if (id->key != NULL && id->agent_fd != -1)
1.214 djm 1015: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.255 djm 1016: data, datalen, key_sign_encode(id->key), compat);
1.214 djm 1017:
1.117 markus 1018: /*
1019: * we have already loaded the private key or
1020: * the private key is stored in external hardware
1021: */
1.255 djm 1022: if (id->key != NULL &&
1023: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT)))
1024: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
1025: key_sign_encode(id->key), compat));
1026:
1.117 markus 1027: /* load the private key from the file */
1.229 jcs 1028: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1029: return SSH_ERR_KEY_NOT_FOUND;
1.255 djm 1030: ret = sshkey_sign(prv, sigp, lenp, data, datalen,
1031: key_sign_encode(prv), compat);
1.214 djm 1032: sshkey_free(prv);
1.117 markus 1033: return (ret);
1.51 markus 1034: }
1035:
1.76 itojun 1036: static int
1.255 djm 1037: id_filename_matches(Identity *id, Identity *private_id)
1038: {
1039: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1040: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1041: size_t i, slen;
1042:
1043: if (strcmp(id->filename, private_id->filename) == 0)
1044: return 1;
1045: for (i = 0; suffixes[i]; i++) {
1046: slen = strlen(suffixes[i]);
1047: if (len > slen && plen == len - slen &&
1048: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1049: memcmp(id->filename, private_id->filename, plen) == 0)
1050: return 1;
1051: }
1052: return 0;
1053: }
1054:
1055: static int
1.117 markus 1056: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1057: {
1058: Buffer b;
1.227 djm 1059: Identity *private_id;
1.32 markus 1060: u_char *blob, *signature;
1.214 djm 1061: size_t slen;
1.227 djm 1062: u_int bloblen, skip = 0;
1063: int matched, ret = -1, have_sig = 1;
1.182 djm 1064: char *fp;
1.1 markus 1065:
1.222 djm 1066: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1067: SSH_FP_DEFAULT)) == NULL)
1068: return 0;
1.227 djm 1069: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1070: free(fp);
1.51 markus 1071:
1.117 markus 1072: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1073: /* we cannot handle this key */
1.30 markus 1074: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1075: return 0;
1076: }
1.1 markus 1077: /* data to be signed */
1078: buffer_init(&b);
1.26 markus 1079: if (datafellows & SSH_OLD_SESSIONID) {
1080: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1081: skip = session_id2_len;
1.26 markus 1082: } else {
1.14 markus 1083: buffer_put_string(&b, session_id2, session_id2_len);
1084: skip = buffer_len(&b);
1085: }
1.1 markus 1086: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1087: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1088: buffer_put_cstring(&b,
1.30 markus 1089: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1090: "ssh-userauth" :
1.20 markus 1091: authctxt->service);
1.30 markus 1092: if (datafellows & SSH_BUG_PKAUTH) {
1093: buffer_put_char(&b, have_sig);
1094: } else {
1095: buffer_put_cstring(&b, authctxt->method->name);
1096: buffer_put_char(&b, have_sig);
1.255 djm 1097: buffer_put_cstring(&b, key_sign_encode(id->key));
1.30 markus 1098: }
1.1 markus 1099: buffer_put_string(&b, blob, bloblen);
1100:
1.227 djm 1101: /*
1102: * If the key is an certificate, try to find a matching private key
1103: * and use it to complete the signature.
1.241 djm 1104: * If no such private key exists, fall back to trying the certificate
1105: * key itself in case it has a private half already loaded.
1.227 djm 1106: */
1107: if (key_is_cert(id->key)) {
1108: matched = 0;
1109: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1110: if (sshkey_equal_public(id->key, private_id->key) &&
1111: id->key->type != private_id->key->type) {
1112: id = private_id;
1113: matched = 1;
1114: break;
1115: }
1116: }
1.255 djm 1117: /*
1118: * Exact key matches are preferred, but also allow
1119: * filename matches for non-PKCS#11/agent keys that
1120: * didn't load public keys. This supports the case
1121: * of keeping just a private key file and public
1122: * certificate on disk.
1123: */
1124: if (!matched && !id->isprivate && id->agent_fd == -1 &&
1125: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1126: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1127: if (private_id->key == NULL &&
1128: id_filename_matches(id, private_id)) {
1129: id = private_id;
1130: matched = 1;
1131: break;
1132: }
1133: }
1134: }
1.227 djm 1135: if (matched) {
1136: debug2("%s: using private key \"%s\"%s for "
1137: "certificate", __func__, id->filename,
1138: id->agent_fd != -1 ? " from agent" : "");
1139: } else {
1.240 djm 1140: debug("%s: no separate private key for certificate "
1.227 djm 1141: "\"%s\"", __func__, id->filename);
1142: }
1143: }
1144:
1.1 markus 1145: /* generate signature */
1.117 markus 1146: ret = identity_sign(id, &signature, &slen,
1.214 djm 1147: buffer_ptr(&b), buffer_len(&b), datafellows);
1148: if (ret != 0) {
1.239 djm 1149: if (ret != SSH_ERR_KEY_NOT_FOUND)
1150: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1151: free(blob);
1.17 markus 1152: buffer_free(&b);
1153: return 0;
1154: }
1.28 markus 1155: #ifdef DEBUG_PK
1.1 markus 1156: buffer_dump(&b);
1157: #endif
1.30 markus 1158: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1159: buffer_clear(&b);
1160: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1161: skip = session_id2_len;
1.10 markus 1162: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1163: buffer_put_cstring(&b, authctxt->server_user);
1164: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1165: buffer_put_cstring(&b, authctxt->method->name);
1166: buffer_put_char(&b, have_sig);
1.30 markus 1167: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1168: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1169: buffer_put_string(&b, blob, bloblen);
1170: }
1.197 djm 1171: free(blob);
1.51 markus 1172:
1.1 markus 1173: /* append signature */
1174: buffer_put_string(&b, signature, slen);
1.197 djm 1175: free(signature);
1.1 markus 1176:
1177: /* skip session id and packet type */
1.14 markus 1178: if (buffer_len(&b) < skip + 1)
1.20 markus 1179: fatal("userauth_pubkey: internal error");
1.14 markus 1180: buffer_consume(&b, skip + 1);
1.1 markus 1181:
1182: /* put remaining data from buffer into packet */
1183: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1184: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1185: buffer_free(&b);
1186: packet_send();
1.17 markus 1187:
1188: return 1;
1.16 markus 1189: }
1190:
1.76 itojun 1191: static int
1.117 markus 1192: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1193: {
1.51 markus 1194: u_char *blob;
1.97 markus 1195: u_int bloblen, have_sig = 0;
1.20 markus 1196:
1.51 markus 1197: debug3("send_pubkey_test");
1.16 markus 1198:
1.117 markus 1199: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1200: /* we cannot handle this key */
1201: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1202: return 0;
1203: }
1.51 markus 1204: /* register callback for USERAUTH_PK_OK message */
1205: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1206:
1207: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1208: packet_put_cstring(authctxt->server_user);
1209: packet_put_cstring(authctxt->service);
1210: packet_put_cstring(authctxt->method->name);
1211: packet_put_char(have_sig);
1212: if (!(datafellows & SSH_BUG_PKAUTH))
1.255 djm 1213: packet_put_cstring(key_sign_encode(id->key));
1.51 markus 1214: packet_put_string(blob, bloblen);
1.197 djm 1215: free(blob);
1.51 markus 1216: packet_send();
1217: return 1;
1218: }
1219:
1.259 ! markus 1220: static struct sshkey *
1.229 jcs 1221: load_identity_file(Identity *id)
1.51 markus 1222: {
1.259 ! markus 1223: struct sshkey *private = NULL;
1.229 jcs 1224: char prompt[300], *passphrase, *comment;
1.215 djm 1225: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1226: struct stat st;
1.16 markus 1227:
1.229 jcs 1228: if (stat(id->filename, &st) < 0) {
1229: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1230: id->filename, strerror(errno));
1.52 markus 1231: return NULL;
1232: }
1.214 djm 1233: snprintf(prompt, sizeof prompt,
1.229 jcs 1234: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1235: for (i = 0; i <= options.number_of_password_prompts; i++) {
1236: if (i == 0)
1237: passphrase = "";
1238: else {
1.20 markus 1239: passphrase = read_passphrase(prompt, 0);
1.214 djm 1240: if (*passphrase == '\0') {
1.20 markus 1241: debug2("no passphrase given, try next key");
1.214 djm 1242: free(passphrase);
1243: break;
1244: }
1245: }
1.229 jcs 1246: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1247: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1248: case 0:
1249: break;
1250: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1251: if (options.batch_mode) {
1252: quit = 1;
1253: break;
1254: }
1.215 djm 1255: if (i != 0)
1256: debug2("bad passphrase given, try again...");
1.214 djm 1257: break;
1258: case SSH_ERR_SYSTEM_ERROR:
1259: if (errno == ENOENT) {
1260: debug2("Load key \"%s\": %s",
1.229 jcs 1261: id->filename, ssh_err(r));
1.51 markus 1262: quit = 1;
1.214 djm 1263: break;
1.20 markus 1264: }
1.214 djm 1265: /* FALLTHROUGH */
1266: default:
1.229 jcs 1267: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1268: quit = 1;
1269: break;
1270: }
1.230 djm 1271: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1272: !(id->key && id->isprivate))
1273: maybe_add_key_to_agent(id->filename, private, comment,
1274: passphrase);
1.214 djm 1275: if (i > 0) {
1.204 djm 1276: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1277: free(passphrase);
1.16 markus 1278: }
1.232 mmcc 1279: free(comment);
1.214 djm 1280: if (private != NULL || quit)
1281: break;
1.16 markus 1282: }
1.51 markus 1283: return private;
1284: }
1285:
1.117 markus 1286: /*
1287: * try keys in the following order:
1.227 djm 1288: * 1. certificates listed in the config file
1289: * 2. other input certificates
1290: * 3. agent keys that are found in the config file
1291: * 4. other agent keys
1292: * 5. keys that are only listed in the config file
1.117 markus 1293: */
1294: static void
1295: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1296: {
1.214 djm 1297: struct identity *id, *id2, *tmp;
1298: struct idlist agent, files, *preferred;
1299: struct sshkey *key;
1.230 djm 1300: int agent_fd = -1, i, r, found;
1.214 djm 1301: size_t j;
1302: struct ssh_identitylist *idlist;
1.51 markus 1303:
1.117 markus 1304: TAILQ_INIT(&agent); /* keys from the agent */
1305: TAILQ_INIT(&files); /* keys from the config file */
1306: preferred = &authctxt->keys;
1307: TAILQ_INIT(preferred); /* preferred order of keys */
1308:
1.190 djm 1309: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1310: for (i = 0; i < options.num_identity_files; i++) {
1311: key = options.identity_keys[i];
1.180 djm 1312: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1313: continue;
1314: options.identity_keys[i] = NULL;
1.150 djm 1315: id = xcalloc(1, sizeof(*id));
1.230 djm 1316: id->agent_fd = -1;
1.117 markus 1317: id->key = key;
1318: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1319: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1320: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1321: }
1.227 djm 1322: /* list of certificates specified by user */
1323: for (i = 0; i < options.num_certificate_files; i++) {
1324: key = options.certificates[i];
1325: if (!key_is_cert(key) || key->cert == NULL ||
1326: key->cert->type != SSH2_CERT_TYPE_USER)
1327: continue;
1328: id = xcalloc(1, sizeof(*id));
1.230 djm 1329: id->agent_fd = -1;
1.227 djm 1330: id->key = key;
1331: id->filename = xstrdup(options.certificate_files[i]);
1332: id->userprovided = options.certificate_file_userprovided[i];
1333: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1334: }
1335: /* list of keys supported by the agent */
1.214 djm 1336: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1337: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1338: debug("%s: ssh_get_authentication_socket: %s",
1339: __func__, ssh_err(r));
1.258 naddy 1340: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1341: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1342: debug("%s: ssh_fetch_identitylist: %s",
1343: __func__, ssh_err(r));
1.237 markus 1344: close(agent_fd);
1.214 djm 1345: } else {
1346: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1347: found = 0;
1348: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1349: /*
1350: * agent keys from the config file are
1351: * preferred
1352: */
1353: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1354: TAILQ_REMOVE(&files, id, next);
1355: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1356: id->agent_fd = agent_fd;
1.117 markus 1357: found = 1;
1358: break;
1359: }
1360: }
1.135 markus 1361: if (!found && !options.identities_only) {
1.150 djm 1362: id = xcalloc(1, sizeof(*id));
1.214 djm 1363: /* XXX "steals" key/comment from idlist */
1364: id->key = idlist->keys[j];
1365: id->filename = idlist->comments[j];
1366: idlist->keys[j] = NULL;
1367: idlist->comments[j] = NULL;
1368: id->agent_fd = agent_fd;
1.117 markus 1369: TAILQ_INSERT_TAIL(&agent, id, next);
1370: }
1371: }
1.214 djm 1372: ssh_free_identitylist(idlist);
1.117 markus 1373: /* append remaining agent keys */
1374: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1375: TAILQ_REMOVE(&agent, id, next);
1376: TAILQ_INSERT_TAIL(preferred, id, next);
1377: }
1.214 djm 1378: authctxt->agent_fd = agent_fd;
1.244 djm 1379: }
1380: /* Prefer PKCS11 keys that are explicitly listed */
1381: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1382: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1383: continue;
1384: found = 0;
1385: TAILQ_FOREACH(id2, &files, next) {
1386: if (id2->key == NULL ||
1387: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1388: continue;
1389: if (sshkey_equal(id->key, id2->key)) {
1390: TAILQ_REMOVE(&files, id, next);
1391: TAILQ_INSERT_TAIL(preferred, id, next);
1392: found = 1;
1393: break;
1394: }
1395: }
1396: /* If IdentitiesOnly set and key not found then don't use it */
1397: if (!found && options.identities_only) {
1398: TAILQ_REMOVE(&files, id, next);
1399: explicit_bzero(id, sizeof(*id));
1400: free(id);
1401: }
1.117 markus 1402: }
1403: /* append remaining keys from the config file */
1404: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1405: TAILQ_REMOVE(&files, id, next);
1406: TAILQ_INSERT_TAIL(preferred, id, next);
1407: }
1.228 djm 1408: /* finally, filter by PubkeyAcceptedKeyTypes */
1409: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1410: if (id->key != NULL &&
1411: match_pattern_list(sshkey_ssh_name(id->key),
1412: options.pubkey_key_types, 0) != 1) {
1413: debug("Skipping %s key %s - "
1414: "not in PubkeyAcceptedKeyTypes",
1415: sshkey_ssh_name(id->key), id->filename);
1416: TAILQ_REMOVE(preferred, id, next);
1417: sshkey_free(id->key);
1418: free(id->filename);
1419: memset(id, 0, sizeof(*id));
1420: continue;
1421: }
1.230 djm 1422: debug2("key: %s (%p)%s%s", id->filename, id->key,
1423: id->userprovided ? ", explicit" : "",
1424: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1425: }
1.17 markus 1426: }
1427:
1.117 markus 1428: static void
1429: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1430: {
1.117 markus 1431: Identity *id;
1.51 markus 1432:
1.214 djm 1433: if (authctxt->agent_fd != -1)
1434: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1435: for (id = TAILQ_FIRST(&authctxt->keys); id;
1436: id = TAILQ_FIRST(&authctxt->keys)) {
1437: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1438: sshkey_free(id->key);
1.197 djm 1439: free(id->filename);
1440: free(id);
1.117 markus 1441: }
1.1 markus 1442: }
1443:
1.251 djm 1444: static void
1445: pubkey_reset(Authctxt *authctxt)
1446: {
1447: Identity *id;
1448:
1449: TAILQ_FOREACH(id, &authctxt->keys, next)
1450: id->tried = 0;
1451: }
1452:
1.225 markus 1453: static int
1454: try_identity(Identity *id)
1455: {
1456: if (!id->key)
1457: return (0);
1458: if (key_type_plain(id->key->type) == KEY_RSA &&
1459: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1460: debug("Skipped %s key %s for RSA/MD5 server",
1461: key_type(id->key), id->filename);
1462: return (0);
1463: }
1.257 djm 1464: return 1;
1.225 markus 1465: }
1466:
1.20 markus 1467: int
1468: userauth_pubkey(Authctxt *authctxt)
1469: {
1.117 markus 1470: Identity *id;
1.20 markus 1471: int sent = 0;
1.256 djm 1472: char *fp;
1.20 markus 1473:
1.117 markus 1474: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1475: if (id->tried++)
1476: return (0);
1.127 markus 1477: /* move key to the end of the queue */
1.117 markus 1478: TAILQ_REMOVE(&authctxt->keys, id, next);
1479: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1480: /*
1481: * send a test message if we have the public key. for
1482: * encrypted keys we cannot do this and have to load the
1483: * private key instead
1484: */
1.200 djm 1485: if (id->key != NULL) {
1.225 markus 1486: if (try_identity(id)) {
1.256 djm 1487: if ((fp = sshkey_fingerprint(id->key,
1488: options.fingerprint_hash,
1489: SSH_FP_DEFAULT)) == NULL) {
1490: error("%s: sshkey_fingerprint failed",
1491: __func__);
1492: return 0;
1493: }
1494: debug("Offering public key: %s %s %s",
1495: sshkey_type(id->key), fp, id->filename);
1496: free(fp);
1.200 djm 1497: sent = send_pubkey_test(authctxt, id);
1498: }
1499: } else {
1.117 markus 1500: debug("Trying private key: %s", id->filename);
1.229 jcs 1501: id->key = load_identity_file(id);
1.117 markus 1502: if (id->key != NULL) {
1.225 markus 1503: if (try_identity(id)) {
1504: id->isprivate = 1;
1.200 djm 1505: sent = sign_and_send_pubkey(
1506: authctxt, id);
1507: }
1.117 markus 1508: key_free(id->key);
1509: id->key = NULL;
1.251 djm 1510: id->isprivate = 0;
1.51 markus 1511: }
1512: }
1.117 markus 1513: if (sent)
1514: return (sent);
1.28 markus 1515: }
1.117 markus 1516: return (0);
1.20 markus 1517: }
1518:
1.23 markus 1519: /*
1520: * Send userauth request message specifying keyboard-interactive method.
1521: */
1522: int
1523: userauth_kbdint(Authctxt *authctxt)
1524: {
1525: static int attempt = 0;
1526:
1527: if (attempt++ >= options.number_of_password_prompts)
1528: return 0;
1.82 markus 1529: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1530: if (attempt > 1 && !authctxt->info_req_seen) {
1531: debug3("userauth_kbdint: disable: no info_req_seen");
1532: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1533: return 0;
1534: }
1.23 markus 1535:
1536: debug2("userauth_kbdint");
1537: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1538: packet_put_cstring(authctxt->server_user);
1539: packet_put_cstring(authctxt->service);
1540: packet_put_cstring(authctxt->method->name);
1541: packet_put_cstring(""); /* lang */
1542: packet_put_cstring(options.kbd_interactive_devices ?
1543: options.kbd_interactive_devices : "");
1544: packet_send();
1545:
1546: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1547: return 1;
1548: }
1549:
1550: /*
1.46 markus 1551: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1552: */
1.218 markus 1553: int
1.92 markus 1554: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1555: {
1556: Authctxt *authctxt = ctxt;
1.46 markus 1557: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1558: u_int num_prompts, i;
1.23 markus 1559: int echo = 0;
1560:
1561: debug2("input_userauth_info_req");
1562:
1563: if (authctxt == NULL)
1564: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1565:
1566: authctxt->info_req_seen = 1;
1.23 markus 1567:
1568: name = packet_get_string(NULL);
1569: inst = packet_get_string(NULL);
1570: lang = packet_get_string(NULL);
1571: if (strlen(name) > 0)
1.116 itojun 1572: logit("%s", name);
1.23 markus 1573: if (strlen(inst) > 0)
1.116 itojun 1574: logit("%s", inst);
1.197 djm 1575: free(name);
1576: free(inst);
1577: free(lang);
1.23 markus 1578:
1579: num_prompts = packet_get_int();
1580: /*
1581: * Begin to build info response packet based on prompts requested.
1582: * We commit to providing the correct number of responses, so if
1583: * further on we run into a problem that prevents this, we have to
1584: * be sure and clean this up and send a correct error response.
1585: */
1586: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1587: packet_put_int(num_prompts);
1588:
1.73 markus 1589: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1590: for (i = 0; i < num_prompts; i++) {
1591: prompt = packet_get_string(NULL);
1592: echo = packet_get_char();
1593:
1.77 markus 1594: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1595:
1.49 markus 1596: packet_put_cstring(response);
1.204 djm 1597: explicit_bzero(response, strlen(response));
1.197 djm 1598: free(response);
1599: free(prompt);
1.23 markus 1600: }
1.90 markus 1601: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1602:
1.85 markus 1603: packet_add_padding(64);
1.23 markus 1604: packet_send();
1.218 markus 1605: return 0;
1.68 markus 1606: }
1607:
1.100 markus 1608: static int
1.223 djm 1609: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1610: const u_char *data, size_t datalen)
1.100 markus 1611: {
1.223 djm 1612: struct sshbuf *b;
1.101 markus 1613: struct stat st;
1.100 markus 1614: pid_t pid;
1.223 djm 1615: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1616: u_char rversion = 0, version = 2;
1617: void (*osigchld)(int);
1.100 markus 1618:
1.223 djm 1619: *sigp = NULL;
1620: *lenp = 0;
1.100 markus 1621:
1.101 markus 1622: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1623: error("%s: not installed: %s", __func__, strerror(errno));
1624: return -1;
1625: }
1626: if (fflush(stdout) != 0) {
1627: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1628: return -1;
1629: }
1.100 markus 1630: if (pipe(to) < 0) {
1.223 djm 1631: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1632: return -1;
1633: }
1634: if (pipe(from) < 0) {
1.223 djm 1635: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1636: return -1;
1637: }
1638: if ((pid = fork()) < 0) {
1.223 djm 1639: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1640: return -1;
1641: }
1.223 djm 1642: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1643: if (pid == 0) {
1.174 dtucker 1644: /* keep the socket on exec */
1.223 djm 1645: fcntl(sock, F_SETFD, 0);
1.155 markus 1646: permanently_drop_suid(getuid());
1.100 markus 1647: close(from[0]);
1648: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1649: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1650: close(to[1]);
1651: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1652: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1653: close(from[1]);
1654: close(to[0]);
1.223 djm 1655: /* Close everything but stdio and the socket */
1656: for (i = STDERR_FILENO + 1; i < sock; i++)
1657: close(i);
1658: closefrom(sock + 1);
1659: debug3("%s: [child] pid=%ld, exec %s",
1660: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1661: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1662: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1663: strerror(errno));
1664: }
1665: close(from[1]);
1666: close(to[0]);
1667:
1.223 djm 1668: if ((b = sshbuf_new()) == NULL)
1669: fatal("%s: sshbuf_new failed", __func__);
1670: /* send # of sock, data to be signed */
1.253 djm 1671: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 1672: (r = sshbuf_put_string(b, data, datalen)) != 0)
1673: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1674: if (ssh_msg_send(to[1], version, b) == -1)
1675: fatal("%s: couldn't send request", __func__);
1676: sshbuf_reset(b);
1677: r = ssh_msg_recv(from[0], b);
1.101 markus 1678: close(from[0]);
1679: close(to[1]);
1.223 djm 1680: if (r < 0) {
1681: error("%s: no reply", __func__);
1682: goto fail;
1683: }
1.101 markus 1684:
1.223 djm 1685: errno = 0;
1686: while (waitpid(pid, &status, 0) < 0) {
1687: if (errno != EINTR) {
1688: error("%s: waitpid %ld: %s",
1689: __func__, (long)pid, strerror(errno));
1690: goto fail;
1691: }
1692: }
1693: if (!WIFEXITED(status)) {
1694: error("%s: exited abnormally", __func__);
1695: goto fail;
1696: }
1697: if (WEXITSTATUS(status) != 0) {
1698: error("%s: exited with status %d",
1699: __func__, WEXITSTATUS(status));
1700: goto fail;
1701: }
1702: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1703: error("%s: buffer error: %s", __func__, ssh_err(r));
1704: goto fail;
1705: }
1706: if (rversion != version) {
1707: error("%s: bad version", __func__);
1708: goto fail;
1709: }
1710: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1711: error("%s: buffer error: %s", __func__, ssh_err(r));
1712: fail:
1713: signal(SIGCHLD, osigchld);
1714: sshbuf_free(b);
1.100 markus 1715: return -1;
1716: }
1.223 djm 1717: signal(SIGCHLD, osigchld);
1718: sshbuf_free(b);
1.100 markus 1719:
1720: return 0;
1721: }
1722:
1.68 markus 1723: int
1724: userauth_hostbased(Authctxt *authctxt)
1725: {
1.223 djm 1726: struct ssh *ssh = active_state;
1727: struct sshkey *private = NULL;
1728: struct sshbuf *b = NULL;
1.72 markus 1729: const char *service;
1.223 djm 1730: u_char *sig = NULL, *keyblob = NULL;
1731: char *fp = NULL, *chost = NULL, *lname = NULL;
1732: size_t siglen = 0, keylen = 0;
1733: int i, r, success = 0;
1734:
1735: if (authctxt->ktypes == NULL) {
1736: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1737: authctxt->ktypes = authctxt->oktypes;
1738: }
1.213 djm 1739:
1.223 djm 1740: /*
1741: * Work through each listed type pattern in HostbasedKeyTypes,
1742: * trying each hostkey that matches the type in turn.
1743: */
1744: for (;;) {
1745: if (authctxt->active_ktype == NULL)
1746: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1747: if (authctxt->active_ktype == NULL ||
1748: *authctxt->active_ktype == '\0')
1749: break;
1750: debug3("%s: trying key type %s", __func__,
1751: authctxt->active_ktype);
1.68 markus 1752:
1.223 djm 1753: /* check for a useful key */
1754: private = NULL;
1755: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1756: if (authctxt->sensitive->keys[i] == NULL ||
1757: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1758: continue;
1759: if (match_pattern_list(
1760: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1761: authctxt->active_ktype, 0) != 1)
1.223 djm 1762: continue;
1.68 markus 1763: /* we take and free the key */
1.223 djm 1764: private = authctxt->sensitive->keys[i];
1765: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1766: break;
1767: }
1.223 djm 1768: /* Found one */
1769: if (private != NULL)
1770: break;
1771: /* No more keys of this type; advance */
1772: authctxt->active_ktype = NULL;
1.68 markus 1773: }
1.223 djm 1774: if (private == NULL) {
1775: free(authctxt->oktypes);
1776: authctxt->oktypes = authctxt->ktypes = NULL;
1777: authctxt->active_ktype = NULL;
1.109 markus 1778: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1779: goto out;
1.68 markus 1780: }
1.211 djm 1781:
1.223 djm 1782: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1783: SSH_FP_DEFAULT)) == NULL) {
1784: error("%s: sshkey_fingerprint failed", __func__);
1785: goto out;
1.68 markus 1786: }
1.223 djm 1787: debug("%s: trying hostkey %s %s",
1788: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1789:
1.84 markus 1790: /* figure out a name for the client host */
1.223 djm 1791: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1792: error("%s: cannot get local ipaddr/name", __func__);
1793: goto out;
1.84 markus 1794: }
1.223 djm 1795:
1796: /* XXX sshbuf_put_stringf? */
1797: xasprintf(&chost, "%s.", lname);
1798: debug2("%s: chost %s", __func__, chost);
1.84 markus 1799:
1.72 markus 1800: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1801: authctxt->service;
1.223 djm 1802:
1.68 markus 1803: /* construct data */
1.223 djm 1804: if ((b = sshbuf_new()) == NULL) {
1805: error("%s: sshbuf_new failed", __func__);
1806: goto out;
1807: }
1808: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1809: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1810: goto out;
1811: }
1812: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1813: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1814: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1815: (r = sshbuf_put_cstring(b, service)) != 0 ||
1816: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1817: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1818: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1819: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1820: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1821: error("%s: buffer error: %s", __func__, ssh_err(r));
1822: goto out;
1823: }
1824:
1.68 markus 1825: #ifdef DEBUG_PK
1.223 djm 1826: sshbuf_dump(b, stderr);
1.68 markus 1827: #endif
1.223 djm 1828: if (authctxt->sensitive->external_keysign)
1829: r = ssh_keysign(private, &sig, &siglen,
1830: sshbuf_ptr(b), sshbuf_len(b));
1831: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1832: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1833: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1834: if (r != 0) {
1835: error("sign using hostkey %s %s failed",
1836: sshkey_ssh_name(private), fp);
1837: goto out;
1838: }
1839: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1840: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1841: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1842: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1843: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1844: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1845: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1846: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1847: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1848: (r = sshpkt_send(ssh)) != 0) {
1849: error("%s: packet error: %s", __func__, ssh_err(r));
1850: goto out;
1851: }
1852: success = 1;
1853:
1854: out:
1855: if (sig != NULL) {
1856: explicit_bzero(sig, siglen);
1857: free(sig);
1.68 markus 1858: }
1.223 djm 1859: free(keyblob);
1860: free(lname);
1861: free(fp);
1.197 djm 1862: free(chost);
1.223 djm 1863: sshkey_free(private);
1864: sshbuf_free(b);
1.68 markus 1865:
1.223 djm 1866: return success;
1.23 markus 1867: }
1.170 djm 1868:
1.20 markus 1869: /* find auth method */
1870:
1871: /*
1872: * given auth method name, if configurable options permit this method fill
1873: * in auth_ident field and return true, otherwise return false.
1874: */
1.76 itojun 1875: static int
1.20 markus 1876: authmethod_is_enabled(Authmethod *method)
1877: {
1878: if (method == NULL)
1879: return 0;
1880: /* return false if options indicate this method is disabled */
1881: if (method->enabled == NULL || *method->enabled == 0)
1882: return 0;
1883: /* return false if batch mode is enabled but method needs interactive mode */
1884: if (method->batch_flag != NULL && *method->batch_flag != 0)
1885: return 0;
1886: return 1;
1887: }
1888:
1.76 itojun 1889: static Authmethod *
1.20 markus 1890: authmethod_lookup(const char *name)
1.1 markus 1891: {
1.20 markus 1892: Authmethod *method = NULL;
1893: if (name != NULL)
1894: for (method = authmethods; method->name != NULL; method++)
1895: if (strcmp(name, method->name) == 0)
1896: return method;
1897: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1898: return NULL;
1899: }
1.1 markus 1900:
1.53 markus 1901: /* XXX internal state */
1902: static Authmethod *current = NULL;
1903: static char *supported = NULL;
1904: static char *preferred = NULL;
1.105 deraadt 1905:
1.20 markus 1906: /*
1907: * Given the authentication method list sent by the server, return the
1908: * next method we should try. If the server initially sends a nil list,
1.67 markus 1909: * use a built-in default list.
1.41 stevesk 1910: */
1.76 itojun 1911: static Authmethod *
1.20 markus 1912: authmethod_get(char *authlist)
1913: {
1.53 markus 1914: char *name = NULL;
1.97 markus 1915: u_int next;
1.41 stevesk 1916:
1.20 markus 1917: /* Use a suitable default if we're passed a nil list. */
1918: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1919: authlist = options.preferred_authentications;
1.20 markus 1920:
1.53 markus 1921: if (supported == NULL || strcmp(authlist, supported) != 0) {
1922: debug3("start over, passed a different list %s", authlist);
1.197 djm 1923: free(supported);
1.53 markus 1924: supported = xstrdup(authlist);
1925: preferred = options.preferred_authentications;
1926: debug3("preferred %s", preferred);
1927: current = NULL;
1928: } else if (current != NULL && authmethod_is_enabled(current))
1929: return current;
1.20 markus 1930:
1.53 markus 1931: for (;;) {
1932: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1933: debug("No more authentication methods to try.");
1.53 markus 1934: current = NULL;
1935: return NULL;
1936: }
1937: preferred += next;
1.23 markus 1938: debug3("authmethod_lookup %s", name);
1.53 markus 1939: debug3("remaining preferred: %s", preferred);
1940: if ((current = authmethod_lookup(name)) != NULL &&
1941: authmethod_is_enabled(current)) {
1.23 markus 1942: debug3("authmethod_is_enabled %s", name);
1.109 markus 1943: debug("Next authentication method: %s", name);
1.197 djm 1944: free(name);
1.53 markus 1945: return current;
1.23 markus 1946: }
1.198 dtucker 1947: free(name);
1.1 markus 1948: }
1.53 markus 1949: }
1.1 markus 1950:
1.79 stevesk 1951: static char *
1.53 markus 1952: authmethods_get(void)
1953: {
1954: Authmethod *method = NULL;
1.93 markus 1955: Buffer b;
1956: char *list;
1.27 provos 1957:
1.93 markus 1958: buffer_init(&b);
1.53 markus 1959: for (method = authmethods; method->name != NULL; method++) {
1960: if (authmethod_is_enabled(method)) {
1.93 markus 1961: if (buffer_len(&b) > 0)
1962: buffer_append(&b, ",", 1);
1963: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1964: }
1965: }
1.242 djm 1966: if ((list = sshbuf_dup_string(&b)) == NULL)
1967: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1968: buffer_free(&b);
1969: return list;
1.1 markus 1970: }
1.170 djm 1971:
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