Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.269
1.269 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.268 2018/02/07 22:52:45 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
1.259 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:
1.263 markus 212: ssh_dispatch_run_fatal(active_state, DISPATCH_BLOCK, &kex->done);
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:
1.261 markus 282: int input_userauth_service_accept(int, u_int32_t, struct ssh *);
283: int input_userauth_ext_info(int, u_int32_t, struct ssh *);
284: int input_userauth_success(int, u_int32_t, struct ssh *);
285: int input_userauth_success_unexpected(int, u_int32_t, struct ssh *);
286: int input_userauth_failure(int, u_int32_t, struct ssh *);
287: int input_userauth_banner(int, u_int32_t, struct ssh *);
288: int input_userauth_error(int, u_int32_t, struct ssh *);
289: int input_userauth_info_req(int, u_int32_t, struct ssh *);
290: int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
291: int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
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);
1.261 markus 301: int input_gssapi_response(int type, u_int32_t, struct ssh *);
302: int input_gssapi_token(int type, u_int32_t, struct ssh *);
303: int input_gssapi_hash(int type, u_int32_t, struct ssh *);
304: int input_gssapi_error(int, u_int32_t, struct ssh *);
305: int input_gssapi_errtok(int, u_int32_t, struct ssh *);
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:
1.260 markus 392: ssh->authctxt = &authctxt;
1.231 markus 393: ssh_dispatch_init(ssh, &input_userauth_error);
394: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
395: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.263 markus 396: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.260 markus 397: ssh->authctxt = NULL;
1.20 markus 398:
1.117 markus 399: pubkey_cleanup(&authctxt);
1.231 markus 400: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 401:
1.248 dtucker 402: if (!authctxt.success)
403: fatal("Authentication failed.");
1.109 markus 404: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 405: }
1.119 markus 406:
1.231 markus 407: /* ARGSUSED */
408: int
1.261 markus 409: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 410: {
1.260 markus 411: Authctxt *authctxt = ssh->authctxt;
1.231 markus 412: int r;
413:
414: if (ssh_packet_remaining(ssh) > 0) {
415: char *reply;
416:
417: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
418: goto out;
419: debug2("service_accept: %s", reply);
420: free(reply);
421: } else {
422: debug2("buggy server: service_accept w/o service");
423: }
424: if ((r = sshpkt_get_end(ssh)) != 0)
425: goto out;
426: debug("SSH2_MSG_SERVICE_ACCEPT received");
427:
428: /* initial userauth request */
429: userauth_none(authctxt);
430:
431: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
432: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
433: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
434: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
435: r = 0;
436: out:
437: return r;
438: }
439:
440: /* ARGSUSED */
441: int
1.261 markus 442: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 443: {
1.261 markus 444: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 445: }
446:
1.20 markus 447: void
1.51 markus 448: userauth(Authctxt *authctxt, char *authlist)
449: {
1.170 djm 450: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
451: authctxt->method->cleanup(authctxt);
452:
1.197 djm 453: free(authctxt->methoddata);
454: authctxt->methoddata = NULL;
1.51 markus 455: if (authlist == NULL) {
456: authlist = authctxt->authlist;
457: } else {
1.197 djm 458: free(authctxt->authlist);
1.51 markus 459: authctxt->authlist = authlist;
460: }
461: for (;;) {
462: Authmethod *method = authmethod_get(authlist);
463: if (method == NULL)
1.264 dtucker 464: fatal("%s@%s: Permission denied (%s).",
465: authctxt->server_user, authctxt->host, authlist);
1.51 markus 466: authctxt->method = method;
1.119 markus 467:
468: /* reset the per method handler */
469: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
470: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
471:
472: /* and try new method */
1.51 markus 473: if (method->userauth(authctxt) != 0) {
474: debug2("we sent a %s packet, wait for reply", method->name);
475: break;
476: } else {
477: debug2("we did not send a packet, disable method");
478: method->enabled = NULL;
479: }
480: }
481: }
1.105 deraadt 482:
1.169 djm 483: /* ARGSUSED */
1.218 markus 484: int
1.261 markus 485: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 486: {
1.35 markus 487: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 488: "type %d", type);
1.218 markus 489: return 0;
1.35 markus 490: }
1.105 deraadt 491:
1.169 djm 492: /* ARGSUSED */
1.218 markus 493: int
1.261 markus 494: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 495: {
1.246 djm 496: char *msg, *lang;
1.166 djm 497: u_int len;
1.126 deraadt 498:
1.246 djm 499: debug3("%s", __func__);
500: msg = packet_get_string(&len);
1.35 markus 501: lang = packet_get_string(NULL);
1.246 djm 502: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
503: fmprintf(stderr, "%s", msg);
504: free(msg);
1.197 djm 505: free(lang);
1.218 markus 506: return 0;
1.20 markus 507: }
1.105 deraadt 508:
1.169 djm 509: /* ARGSUSED */
1.218 markus 510: int
1.261 markus 511: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 512: {
1.260 markus 513: Authctxt *authctxt = ssh->authctxt;
1.172 djm 514:
1.20 markus 515: if (authctxt == NULL)
516: fatal("input_userauth_success: no authentication context");
1.197 djm 517: free(authctxt->authlist);
518: authctxt->authlist = NULL;
1.172 djm 519: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
520: authctxt->method->cleanup(authctxt);
1.197 djm 521: free(authctxt->methoddata);
522: authctxt->methoddata = NULL;
1.20 markus 523: authctxt->success = 1; /* break out */
1.218 markus 524: return 0;
1.20 markus 525: }
1.105 deraadt 526:
1.218 markus 527: int
1.261 markus 528: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 529: {
1.260 markus 530: Authctxt *authctxt = ssh->authctxt;
1.172 djm 531:
532: if (authctxt == NULL)
533: fatal("%s: no authentication context", __func__);
534:
535: fatal("Unexpected authentication success during %s.",
536: authctxt->method->name);
1.218 markus 537: return 0;
1.172 djm 538: }
539:
1.169 djm 540: /* ARGSUSED */
1.218 markus 541: int
1.261 markus 542: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 543: {
1.260 markus 544: Authctxt *authctxt = ssh->authctxt;
1.20 markus 545: char *authlist = NULL;
546: int partial;
547:
548: if (authctxt == NULL)
549: fatal("input_userauth_failure: no authentication context");
550:
1.23 markus 551: authlist = packet_get_string(NULL);
1.20 markus 552: partial = packet_get_char();
1.90 markus 553: packet_check_eom();
1.20 markus 554:
1.193 markus 555: if (partial != 0) {
1.247 dtucker 556: verbose("Authenticated with partial success.");
1.193 markus 557: /* reset state */
1.251 djm 558: pubkey_reset(authctxt);
1.193 markus 559: }
1.109 markus 560: debug("Authentications that can continue: %s", authlist);
1.20 markus 561:
1.51 markus 562: userauth(authctxt, authlist);
1.218 markus 563: return 0;
1.51 markus 564: }
1.169 djm 565:
566: /* ARGSUSED */
1.218 markus 567: int
1.261 markus 568: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 569: {
1.260 markus 570: Authctxt *authctxt = ssh->authctxt;
1.259 markus 571: struct sshkey *key = NULL;
1.117 markus 572: Identity *id = NULL;
1.96 markus 573: int pktype, sent = 0;
574: u_int alen, blen;
575: char *pkalg, *fp;
576: u_char *pkblob;
1.51 markus 577:
578: if (authctxt == NULL)
579: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 580:
581: pkalg = packet_get_string(&alen);
582: pkblob = packet_get_string(&blen);
1.90 markus 583: packet_check_eom();
1.51 markus 584:
1.117 markus 585: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 586:
1.117 markus 587: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
588: debug("unknown pkalg %s", pkalg);
589: goto done;
590: }
591: if ((key = key_from_blob(pkblob, blen)) == NULL) {
592: debug("no key from blob. pkalg %s", pkalg);
593: goto done;
594: }
595: if (key->type != pktype) {
596: error("input_userauth_pk_ok: type mismatch "
597: "for decoded key (received %d, expected %d)",
598: key->type, pktype);
599: goto done;
600: }
1.222 djm 601: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
602: SSH_FP_DEFAULT)) == NULL)
603: goto done;
1.117 markus 604: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 605: free(fp);
1.117 markus 606:
1.127 markus 607: /*
608: * search keys in the reverse order, because last candidate has been
609: * moved to the end of the queue. this also avoids confusion by
610: * duplicate keys
611: */
1.136 henning 612: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 613: if (key_equal(key, id->key)) {
614: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 615: break;
616: }
1.117 markus 617: }
618: done:
1.268 dtucker 619: key_free(key);
1.197 djm 620: free(pkalg);
621: free(pkblob);
1.51 markus 622:
1.106 deraadt 623: /* try another method if we did not send a packet */
1.51 markus 624: if (sent == 0)
625: userauth(authctxt, NULL);
1.218 markus 626: return 0;
1.20 markus 627: }
1.121 markus 628:
629: #ifdef GSSAPI
1.133 djm 630: int
1.121 markus 631: userauth_gssapi(Authctxt *authctxt)
632: {
633: Gssctxt *gssctxt = NULL;
1.128 avsm 634: static gss_OID_set gss_supported = NULL;
1.139 djm 635: static u_int mech = 0;
1.121 markus 636: OM_uint32 min;
637: int ok = 0;
638:
639: /* Try one GSSAPI method at a time, rather than sending them all at
640: * once. */
641:
1.128 avsm 642: if (gss_supported == NULL)
643: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 644:
645: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 646: while (mech < gss_supported->count && !ok) {
1.121 markus 647: /* My DER encoding requires length<128 */
1.128 avsm 648: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 649: ssh_gssapi_check_mechanism(&gssctxt,
650: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 651: ok = 1; /* Mechanism works */
652: } else {
653: mech++;
654: }
655: }
656:
1.161 djm 657: if (!ok)
1.139 djm 658: return 0;
1.121 markus 659:
660: authctxt->methoddata=(void *)gssctxt;
661:
662: packet_start(SSH2_MSG_USERAUTH_REQUEST);
663: packet_put_cstring(authctxt->server_user);
664: packet_put_cstring(authctxt->service);
665: packet_put_cstring(authctxt->method->name);
666:
667: packet_put_int(1);
668:
1.129 markus 669: packet_put_int((gss_supported->elements[mech].length) + 2);
670: packet_put_char(SSH_GSS_OIDTYPE);
671: packet_put_char(gss_supported->elements[mech].length);
672: packet_put_raw(gss_supported->elements[mech].elements,
673: gss_supported->elements[mech].length);
1.121 markus 674:
675: packet_send();
676:
677: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
678: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
679: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
680: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
681:
682: mech++; /* Move along to next candidate */
683:
684: return 1;
685: }
686:
1.130 markus 687: static OM_uint32
1.262 djm 688: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 689: {
1.260 markus 690: Authctxt *authctxt = ssh->authctxt;
1.130 markus 691: Gssctxt *gssctxt = authctxt->methoddata;
692: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 693: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
694: gss_buffer_desc gssbuf;
1.132 markus 695: OM_uint32 status, ms, flags;
696: Buffer b;
1.133 djm 697:
1.130 markus 698: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 699: recv_tok, &send_tok, &flags);
1.130 markus 700:
701: if (send_tok.length > 0) {
702: if (GSS_ERROR(status))
703: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
704: else
705: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 706:
1.130 markus 707: packet_put_string(send_tok.value, send_tok.length);
708: packet_send();
709: gss_release_buffer(&ms, &send_tok);
710: }
1.133 djm 711:
1.130 markus 712: if (status == GSS_S_COMPLETE) {
1.132 markus 713: /* send either complete or MIC, depending on mechanism */
714: if (!(flags & GSS_C_INTEG_FLAG)) {
715: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
716: packet_send();
717: } else {
718: ssh_gssapi_buildmic(&b, authctxt->server_user,
719: authctxt->service, "gssapi-with-mic");
720:
721: gssbuf.value = buffer_ptr(&b);
722: gssbuf.length = buffer_len(&b);
1.133 djm 723:
1.132 markus 724: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 725:
1.132 markus 726: if (!GSS_ERROR(status)) {
727: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
728: packet_put_string(mic.value, mic.length);
1.133 djm 729:
1.132 markus 730: packet_send();
731: }
1.133 djm 732:
1.132 markus 733: buffer_free(&b);
734: gss_release_buffer(&ms, &mic);
1.133 djm 735: }
1.130 markus 736: }
1.133 djm 737:
1.130 markus 738: return status;
739: }
740:
1.169 djm 741: /* ARGSUSED */
1.220 djm 742: int
1.261 markus 743: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 744: {
1.260 markus 745: Authctxt *authctxt = ssh->authctxt;
1.121 markus 746: Gssctxt *gssctxt;
747: int oidlen;
748: char *oidv;
749:
750: if (authctxt == NULL)
751: fatal("input_gssapi_response: no authentication context");
752: gssctxt = authctxt->methoddata;
753:
754: /* Setup our OID */
755: oidv = packet_get_string(&oidlen);
756:
1.129 markus 757: if (oidlen <= 2 ||
758: oidv[0] != SSH_GSS_OIDTYPE ||
759: oidv[1] != oidlen - 2) {
1.197 djm 760: free(oidv);
1.129 markus 761: debug("Badly encoded mechanism OID received");
762: userauth(authctxt, NULL);
1.220 djm 763: return 0;
1.121 markus 764: }
1.129 markus 765:
766: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
767: fatal("Server returned different OID than expected");
1.121 markus 768:
769: packet_check_eom();
770:
1.197 djm 771: free(oidv);
1.121 markus 772:
1.262 djm 773: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 774: /* Start again with next method on list */
775: debug("Trying to start again");
776: userauth(authctxt, NULL);
1.220 djm 777: return 0;
1.121 markus 778: }
1.220 djm 779: return 0;
1.121 markus 780: }
781:
1.169 djm 782: /* ARGSUSED */
1.220 djm 783: int
1.261 markus 784: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 785: {
1.260 markus 786: Authctxt *authctxt = ssh->authctxt;
1.121 markus 787: gss_buffer_desc recv_tok;
1.130 markus 788: OM_uint32 status;
1.121 markus 789: u_int slen;
790:
791: if (authctxt == NULL)
792: fatal("input_gssapi_response: no authentication context");
793:
794: recv_tok.value = packet_get_string(&slen);
795: recv_tok.length = slen; /* safe typecast */
796:
797: packet_check_eom();
798:
1.262 djm 799: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 800:
1.197 djm 801: free(recv_tok.value);
1.121 markus 802:
803: if (GSS_ERROR(status)) {
804: /* Start again with the next method in the list */
805: userauth(authctxt, NULL);
1.220 djm 806: return 0;
1.121 markus 807: }
1.220 djm 808: return 0;
1.121 markus 809: }
810:
1.169 djm 811: /* ARGSUSED */
1.220 djm 812: int
1.261 markus 813: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 814: {
1.260 markus 815: Authctxt *authctxt = ssh->authctxt;
1.121 markus 816: Gssctxt *gssctxt;
817: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
818: gss_buffer_desc recv_tok;
1.194 djm 819: OM_uint32 ms;
1.123 deraadt 820: u_int len;
1.121 markus 821:
822: if (authctxt == NULL)
823: fatal("input_gssapi_response: no authentication context");
824: gssctxt = authctxt->methoddata;
825:
1.123 deraadt 826: recv_tok.value = packet_get_string(&len);
827: recv_tok.length = len;
1.121 markus 828:
829: packet_check_eom();
830:
831: /* Stick it into GSSAPI and see what it says */
1.194 djm 832: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 833: &recv_tok, &send_tok, NULL);
1.121 markus 834:
1.197 djm 835: free(recv_tok.value);
1.121 markus 836: gss_release_buffer(&ms, &send_tok);
837:
838: /* Server will be returning a failed packet after this one */
1.220 djm 839: return 0;
1.121 markus 840: }
841:
1.169 djm 842: /* ARGSUSED */
1.220 djm 843: int
1.261 markus 844: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 845: {
846: char *msg;
847: char *lang;
848:
1.194 djm 849: /* maj */(void)packet_get_int();
850: /* min */(void)packet_get_int();
1.121 markus 851: msg=packet_get_string(NULL);
852: lang=packet_get_string(NULL);
853:
854: packet_check_eom();
855:
1.143 stevesk 856: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 857: free(msg);
858: free(lang);
1.220 djm 859: return 0;
1.121 markus 860: }
861: #endif /* GSSAPI */
1.20 markus 862:
1.1 markus 863: int
1.23 markus 864: userauth_none(Authctxt *authctxt)
865: {
866: /* initial userauth request */
867: packet_start(SSH2_MSG_USERAUTH_REQUEST);
868: packet_put_cstring(authctxt->server_user);
869: packet_put_cstring(authctxt->service);
870: packet_put_cstring(authctxt->method->name);
871: packet_send();
872: return 1;
873: }
874:
875: int
1.20 markus 876: userauth_passwd(Authctxt *authctxt)
1.1 markus 877: {
1.6 markus 878: static int attempt = 0;
1.266 dtucker 879: char prompt[256];
1.1 markus 880: char *password;
1.175 dtucker 881: const char *host = options.host_key_alias ? options.host_key_alias :
882: authctxt->host;
1.6 markus 883:
1.13 todd 884: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 885: return 0;
1.13 todd 886:
1.87 deraadt 887: if (attempt != 1)
1.13 todd 888: error("Permission denied, please try again.");
1.1 markus 889:
1.43 itojun 890: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 891: authctxt->server_user, host);
1.1 markus 892: password = read_passphrase(prompt, 0);
893: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 894: packet_put_cstring(authctxt->server_user);
895: packet_put_cstring(authctxt->service);
1.23 markus 896: packet_put_cstring(authctxt->method->name);
1.1 markus 897: packet_put_char(0);
1.49 markus 898: packet_put_cstring(password);
1.204 djm 899: explicit_bzero(password, strlen(password));
1.197 djm 900: free(password);
1.85 markus 901: packet_add_padding(64);
1.1 markus 902: packet_send();
1.99 markus 903:
1.104 deraadt 904: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 905: &input_userauth_passwd_changereq);
906:
1.1 markus 907: return 1;
908: }
1.169 djm 909:
1.99 markus 910: /*
911: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
912: */
1.169 djm 913: /* ARGSUSED */
1.218 markus 914: int
1.261 markus 915: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 916: {
1.260 markus 917: Authctxt *authctxt = ssh->authctxt;
1.99 markus 918: char *info, *lang, *password = NULL, *retype = NULL;
1.266 dtucker 919: char prompt[256];
1.252 djm 920: const char *host;
1.99 markus 921:
922: debug2("input_userauth_passwd_changereq");
923:
924: if (authctxt == NULL)
925: fatal("input_userauth_passwd_changereq: "
926: "no authentication context");
1.252 djm 927: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 928:
929: info = packet_get_string(NULL);
930: lang = packet_get_string(NULL);
931: if (strlen(info) > 0)
1.116 itojun 932: logit("%s", info);
1.197 djm 933: free(info);
934: free(lang);
1.99 markus 935: packet_start(SSH2_MSG_USERAUTH_REQUEST);
936: packet_put_cstring(authctxt->server_user);
937: packet_put_cstring(authctxt->service);
938: packet_put_cstring(authctxt->method->name);
939: packet_put_char(1); /* additional info */
1.104 deraadt 940: snprintf(prompt, sizeof(prompt),
1.99 markus 941: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 942: authctxt->server_user, host);
1.99 markus 943: password = read_passphrase(prompt, 0);
944: packet_put_cstring(password);
1.204 djm 945: explicit_bzero(password, strlen(password));
1.197 djm 946: free(password);
1.99 markus 947: password = NULL;
948: while (password == NULL) {
1.104 deraadt 949: snprintf(prompt, sizeof(prompt),
1.99 markus 950: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 951: authctxt->server_user, host);
1.99 markus 952: password = read_passphrase(prompt, RP_ALLOW_EOF);
953: if (password == NULL) {
954: /* bail out */
1.218 markus 955: return 0;
1.99 markus 956: }
1.104 deraadt 957: snprintf(prompt, sizeof(prompt),
1.99 markus 958: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 959: authctxt->server_user, host);
1.99 markus 960: retype = read_passphrase(prompt, 0);
961: if (strcmp(password, retype) != 0) {
1.204 djm 962: explicit_bzero(password, strlen(password));
1.197 djm 963: free(password);
1.116 itojun 964: logit("Mismatch; try again, EOF to quit.");
1.99 markus 965: password = NULL;
966: }
1.204 djm 967: explicit_bzero(retype, strlen(retype));
1.197 djm 968: free(retype);
1.99 markus 969: }
970: packet_put_cstring(password);
1.204 djm 971: explicit_bzero(password, strlen(password));
1.197 djm 972: free(password);
1.99 markus 973: packet_add_padding(64);
974: packet_send();
1.104 deraadt 975:
976: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 977: &input_userauth_passwd_changereq);
1.218 markus 978: return 0;
1.117 markus 979: }
980:
1.231 markus 981: static const char *
1.255 djm 982: key_sign_encode(const struct sshkey *key)
1.231 markus 983: {
984: struct ssh *ssh = active_state;
985:
1.255 djm 986: if (key->type == KEY_RSA) {
1.231 markus 987: switch (ssh->kex->rsa_sha2) {
988: case 256:
989: return "rsa-sha2-256";
990: case 512:
991: return "rsa-sha2-512";
992: }
993: }
1.255 djm 994: return key_ssh_name(key);
1.231 markus 995: }
996:
1.269 ! djm 997: /*
! 998: * Some agents will return ssh-rsa signatures when asked to make a
! 999: * rsa-sha2-* signature. Check what they actually gave back and warn the
! 1000: * user if the agent has returned an unexpected type.
! 1001: */
! 1002: static int
! 1003: check_sigtype(const struct sshkey *key, const u_char *sig, size_t len)
! 1004: {
! 1005: int r;
! 1006: char *sigtype = NULL;
! 1007: const char *alg = key_sign_encode(key);
! 1008:
! 1009: if ((r = sshkey_sigtype(sig, len, &sigtype)) != 0)
! 1010: return r;
! 1011: if (strcmp(sigtype, alg) != 0) {
! 1012: logit("warning: agent returned different signature type %s "
! 1013: "(expected %s)", sigtype, alg);
! 1014: }
! 1015: free(sigtype);
! 1016: /* Incorrect signature types aren't an error ... yet */
! 1017: return 0;
! 1018: }
! 1019:
1.117 markus 1020: static int
1.214 djm 1021: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1022: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1023: {
1.259 markus 1024: struct sshkey *prv;
1.269 ! djm 1025: int r;
1.99 markus 1026:
1.117 markus 1027: /* the agent supports this key */
1.269 ! djm 1028: if (id->key != NULL && id->agent_fd != -1) {
! 1029: if ((r = ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
! 1030: data, datalen, key_sign_encode(id->key), compat)) != 0 ||
! 1031: (r = check_sigtype(id->key, *sigp, *lenp)) != 0)
! 1032: return r;
! 1033: return 0;
! 1034: }
1.214 djm 1035:
1.117 markus 1036: /*
1037: * we have already loaded the private key or
1038: * the private key is stored in external hardware
1039: */
1.255 djm 1040: if (id->key != NULL &&
1041: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT)))
1042: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
1043: key_sign_encode(id->key), compat));
1044:
1.117 markus 1045: /* load the private key from the file */
1.229 jcs 1046: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1047: return SSH_ERR_KEY_NOT_FOUND;
1.265 djm 1048: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1049: error("%s: private key %s contents do not match public",
1050: __func__, id->filename);
1051: return SSH_ERR_KEY_NOT_FOUND;
1052: }
1.269 ! djm 1053: r = sshkey_sign(prv, sigp, lenp, data, datalen,
1.255 djm 1054: key_sign_encode(prv), compat);
1.214 djm 1055: sshkey_free(prv);
1.269 ! djm 1056: return r;
1.51 markus 1057: }
1058:
1.76 itojun 1059: static int
1.255 djm 1060: id_filename_matches(Identity *id, Identity *private_id)
1061: {
1062: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1063: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1064: size_t i, slen;
1065:
1066: if (strcmp(id->filename, private_id->filename) == 0)
1067: return 1;
1068: for (i = 0; suffixes[i]; i++) {
1069: slen = strlen(suffixes[i]);
1070: if (len > slen && plen == len - slen &&
1071: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1072: memcmp(id->filename, private_id->filename, plen) == 0)
1073: return 1;
1074: }
1075: return 0;
1076: }
1077:
1078: static int
1.117 markus 1079: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1080: {
1081: Buffer b;
1.227 djm 1082: Identity *private_id;
1.32 markus 1083: u_char *blob, *signature;
1.214 djm 1084: size_t slen;
1.227 djm 1085: u_int bloblen, skip = 0;
1086: int matched, ret = -1, have_sig = 1;
1.182 djm 1087: char *fp;
1.1 markus 1088:
1.222 djm 1089: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1090: SSH_FP_DEFAULT)) == NULL)
1091: return 0;
1.227 djm 1092: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1093: free(fp);
1.51 markus 1094:
1.117 markus 1095: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1096: /* we cannot handle this key */
1.30 markus 1097: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1098: return 0;
1099: }
1.1 markus 1100: /* data to be signed */
1101: buffer_init(&b);
1.26 markus 1102: if (datafellows & SSH_OLD_SESSIONID) {
1103: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1104: skip = session_id2_len;
1.26 markus 1105: } else {
1.14 markus 1106: buffer_put_string(&b, session_id2, session_id2_len);
1107: skip = buffer_len(&b);
1108: }
1.1 markus 1109: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1110: buffer_put_cstring(&b, authctxt->server_user);
1.267 djm 1111: buffer_put_cstring(&b, authctxt->service);
1112: buffer_put_cstring(&b, authctxt->method->name);
1113: buffer_put_char(&b, have_sig);
1114: buffer_put_cstring(&b, key_sign_encode(id->key));
1.1 markus 1115: buffer_put_string(&b, blob, bloblen);
1116:
1.227 djm 1117: /*
1118: * If the key is an certificate, try to find a matching private key
1119: * and use it to complete the signature.
1.241 djm 1120: * If no such private key exists, fall back to trying the certificate
1121: * key itself in case it has a private half already loaded.
1.227 djm 1122: */
1123: if (key_is_cert(id->key)) {
1124: matched = 0;
1125: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1126: if (sshkey_equal_public(id->key, private_id->key) &&
1127: id->key->type != private_id->key->type) {
1128: id = private_id;
1129: matched = 1;
1130: break;
1131: }
1132: }
1.255 djm 1133: /*
1134: * Exact key matches are preferred, but also allow
1135: * filename matches for non-PKCS#11/agent keys that
1136: * didn't load public keys. This supports the case
1137: * of keeping just a private key file and public
1138: * certificate on disk.
1139: */
1140: if (!matched && !id->isprivate && id->agent_fd == -1 &&
1141: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1142: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1143: if (private_id->key == NULL &&
1144: id_filename_matches(id, private_id)) {
1145: id = private_id;
1146: matched = 1;
1147: break;
1148: }
1149: }
1150: }
1.227 djm 1151: if (matched) {
1152: debug2("%s: using private key \"%s\"%s for "
1153: "certificate", __func__, id->filename,
1154: id->agent_fd != -1 ? " from agent" : "");
1155: } else {
1.240 djm 1156: debug("%s: no separate private key for certificate "
1.227 djm 1157: "\"%s\"", __func__, id->filename);
1158: }
1159: }
1160:
1.1 markus 1161: /* generate signature */
1.117 markus 1162: ret = identity_sign(id, &signature, &slen,
1.214 djm 1163: buffer_ptr(&b), buffer_len(&b), datafellows);
1164: if (ret != 0) {
1.239 djm 1165: if (ret != SSH_ERR_KEY_NOT_FOUND)
1166: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1167: free(blob);
1.17 markus 1168: buffer_free(&b);
1169: return 0;
1170: }
1.28 markus 1171: #ifdef DEBUG_PK
1.1 markus 1172: buffer_dump(&b);
1173: #endif
1.197 djm 1174: free(blob);
1.51 markus 1175:
1.1 markus 1176: /* append signature */
1177: buffer_put_string(&b, signature, slen);
1.197 djm 1178: free(signature);
1.1 markus 1179:
1180: /* skip session id and packet type */
1.14 markus 1181: if (buffer_len(&b) < skip + 1)
1.20 markus 1182: fatal("userauth_pubkey: internal error");
1.14 markus 1183: buffer_consume(&b, skip + 1);
1.1 markus 1184:
1185: /* put remaining data from buffer into packet */
1186: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1187: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1188: buffer_free(&b);
1189: packet_send();
1.17 markus 1190:
1191: return 1;
1.16 markus 1192: }
1193:
1.76 itojun 1194: static int
1.117 markus 1195: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1196: {
1.51 markus 1197: u_char *blob;
1.97 markus 1198: u_int bloblen, have_sig = 0;
1.20 markus 1199:
1.51 markus 1200: debug3("send_pubkey_test");
1.16 markus 1201:
1.117 markus 1202: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1203: /* we cannot handle this key */
1204: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1205: return 0;
1206: }
1.51 markus 1207: /* register callback for USERAUTH_PK_OK message */
1208: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1209:
1210: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1211: packet_put_cstring(authctxt->server_user);
1212: packet_put_cstring(authctxt->service);
1213: packet_put_cstring(authctxt->method->name);
1214: packet_put_char(have_sig);
1.267 djm 1215: packet_put_cstring(key_sign_encode(id->key));
1.51 markus 1216: packet_put_string(blob, bloblen);
1.197 djm 1217: free(blob);
1.51 markus 1218: packet_send();
1219: return 1;
1220: }
1221:
1.259 markus 1222: static struct sshkey *
1.229 jcs 1223: load_identity_file(Identity *id)
1.51 markus 1224: {
1.259 markus 1225: struct sshkey *private = NULL;
1.229 jcs 1226: char prompt[300], *passphrase, *comment;
1.215 djm 1227: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1228: struct stat st;
1.16 markus 1229:
1.229 jcs 1230: if (stat(id->filename, &st) < 0) {
1231: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1232: id->filename, strerror(errno));
1.52 markus 1233: return NULL;
1234: }
1.214 djm 1235: snprintf(prompt, sizeof prompt,
1.229 jcs 1236: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1237: for (i = 0; i <= options.number_of_password_prompts; i++) {
1238: if (i == 0)
1239: passphrase = "";
1240: else {
1.20 markus 1241: passphrase = read_passphrase(prompt, 0);
1.214 djm 1242: if (*passphrase == '\0') {
1.20 markus 1243: debug2("no passphrase given, try next key");
1.214 djm 1244: free(passphrase);
1245: break;
1246: }
1247: }
1.229 jcs 1248: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1249: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1250: case 0:
1251: break;
1252: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1253: if (options.batch_mode) {
1254: quit = 1;
1255: break;
1256: }
1.215 djm 1257: if (i != 0)
1258: debug2("bad passphrase given, try again...");
1.214 djm 1259: break;
1260: case SSH_ERR_SYSTEM_ERROR:
1261: if (errno == ENOENT) {
1262: debug2("Load key \"%s\": %s",
1.229 jcs 1263: id->filename, ssh_err(r));
1.51 markus 1264: quit = 1;
1.214 djm 1265: break;
1.20 markus 1266: }
1.214 djm 1267: /* FALLTHROUGH */
1268: default:
1.229 jcs 1269: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1270: quit = 1;
1271: break;
1272: }
1.230 djm 1273: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1274: !(id->key && id->isprivate))
1275: maybe_add_key_to_agent(id->filename, private, comment,
1276: passphrase);
1.214 djm 1277: if (i > 0) {
1.204 djm 1278: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1279: free(passphrase);
1.16 markus 1280: }
1.232 mmcc 1281: free(comment);
1.214 djm 1282: if (private != NULL || quit)
1283: break;
1.16 markus 1284: }
1.51 markus 1285: return private;
1286: }
1287:
1.117 markus 1288: /*
1289: * try keys in the following order:
1.227 djm 1290: * 1. certificates listed in the config file
1291: * 2. other input certificates
1292: * 3. agent keys that are found in the config file
1293: * 4. other agent keys
1294: * 5. keys that are only listed in the config file
1.117 markus 1295: */
1296: static void
1297: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1298: {
1.214 djm 1299: struct identity *id, *id2, *tmp;
1300: struct idlist agent, files, *preferred;
1301: struct sshkey *key;
1.230 djm 1302: int agent_fd = -1, i, r, found;
1.214 djm 1303: size_t j;
1304: struct ssh_identitylist *idlist;
1.51 markus 1305:
1.117 markus 1306: TAILQ_INIT(&agent); /* keys from the agent */
1307: TAILQ_INIT(&files); /* keys from the config file */
1308: preferred = &authctxt->keys;
1309: TAILQ_INIT(preferred); /* preferred order of keys */
1310:
1.190 djm 1311: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1312: for (i = 0; i < options.num_identity_files; i++) {
1313: key = options.identity_keys[i];
1.180 djm 1314: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1315: continue;
1316: options.identity_keys[i] = NULL;
1.150 djm 1317: id = xcalloc(1, sizeof(*id));
1.230 djm 1318: id->agent_fd = -1;
1.117 markus 1319: id->key = key;
1320: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1321: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1322: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1323: }
1.227 djm 1324: /* list of certificates specified by user */
1325: for (i = 0; i < options.num_certificate_files; i++) {
1326: key = options.certificates[i];
1327: if (!key_is_cert(key) || key->cert == NULL ||
1328: key->cert->type != SSH2_CERT_TYPE_USER)
1329: continue;
1330: id = xcalloc(1, sizeof(*id));
1.230 djm 1331: id->agent_fd = -1;
1.227 djm 1332: id->key = key;
1333: id->filename = xstrdup(options.certificate_files[i]);
1334: id->userprovided = options.certificate_file_userprovided[i];
1335: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1336: }
1337: /* list of keys supported by the agent */
1.214 djm 1338: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1339: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1340: debug("%s: ssh_get_authentication_socket: %s",
1341: __func__, ssh_err(r));
1.258 naddy 1342: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1343: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1344: debug("%s: ssh_fetch_identitylist: %s",
1345: __func__, ssh_err(r));
1.237 markus 1346: close(agent_fd);
1.214 djm 1347: } else {
1348: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1349: found = 0;
1350: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1351: /*
1352: * agent keys from the config file are
1353: * preferred
1354: */
1355: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1356: TAILQ_REMOVE(&files, id, next);
1357: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1358: id->agent_fd = agent_fd;
1.117 markus 1359: found = 1;
1360: break;
1361: }
1362: }
1.135 markus 1363: if (!found && !options.identities_only) {
1.150 djm 1364: id = xcalloc(1, sizeof(*id));
1.214 djm 1365: /* XXX "steals" key/comment from idlist */
1366: id->key = idlist->keys[j];
1367: id->filename = idlist->comments[j];
1368: idlist->keys[j] = NULL;
1369: idlist->comments[j] = NULL;
1370: id->agent_fd = agent_fd;
1.117 markus 1371: TAILQ_INSERT_TAIL(&agent, id, next);
1372: }
1373: }
1.214 djm 1374: ssh_free_identitylist(idlist);
1.117 markus 1375: /* append remaining agent keys */
1376: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1377: TAILQ_REMOVE(&agent, id, next);
1378: TAILQ_INSERT_TAIL(preferred, id, next);
1379: }
1.214 djm 1380: authctxt->agent_fd = agent_fd;
1.244 djm 1381: }
1382: /* Prefer PKCS11 keys that are explicitly listed */
1383: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1384: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1385: continue;
1386: found = 0;
1387: TAILQ_FOREACH(id2, &files, next) {
1388: if (id2->key == NULL ||
1389: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1390: continue;
1391: if (sshkey_equal(id->key, id2->key)) {
1392: TAILQ_REMOVE(&files, id, next);
1393: TAILQ_INSERT_TAIL(preferred, id, next);
1394: found = 1;
1395: break;
1396: }
1397: }
1398: /* If IdentitiesOnly set and key not found then don't use it */
1399: if (!found && options.identities_only) {
1400: TAILQ_REMOVE(&files, id, next);
1401: explicit_bzero(id, sizeof(*id));
1402: free(id);
1403: }
1.117 markus 1404: }
1405: /* append remaining keys from the config file */
1406: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1407: TAILQ_REMOVE(&files, id, next);
1408: TAILQ_INSERT_TAIL(preferred, id, next);
1409: }
1.228 djm 1410: /* finally, filter by PubkeyAcceptedKeyTypes */
1411: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1412: if (id->key != NULL &&
1413: match_pattern_list(sshkey_ssh_name(id->key),
1414: options.pubkey_key_types, 0) != 1) {
1415: debug("Skipping %s key %s - "
1416: "not in PubkeyAcceptedKeyTypes",
1417: sshkey_ssh_name(id->key), id->filename);
1418: TAILQ_REMOVE(preferred, id, next);
1419: sshkey_free(id->key);
1420: free(id->filename);
1421: memset(id, 0, sizeof(*id));
1422: continue;
1423: }
1.230 djm 1424: debug2("key: %s (%p)%s%s", id->filename, id->key,
1425: id->userprovided ? ", explicit" : "",
1426: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1427: }
1.17 markus 1428: }
1429:
1.117 markus 1430: static void
1431: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1432: {
1.117 markus 1433: Identity *id;
1.51 markus 1434:
1.214 djm 1435: if (authctxt->agent_fd != -1)
1436: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1437: for (id = TAILQ_FIRST(&authctxt->keys); id;
1438: id = TAILQ_FIRST(&authctxt->keys)) {
1439: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1440: sshkey_free(id->key);
1.197 djm 1441: free(id->filename);
1442: free(id);
1.117 markus 1443: }
1.1 markus 1444: }
1445:
1.251 djm 1446: static void
1447: pubkey_reset(Authctxt *authctxt)
1448: {
1449: Identity *id;
1450:
1451: TAILQ_FOREACH(id, &authctxt->keys, next)
1452: id->tried = 0;
1453: }
1454:
1.225 markus 1455: static int
1456: try_identity(Identity *id)
1457: {
1458: if (!id->key)
1459: return (0);
1460: if (key_type_plain(id->key->type) == KEY_RSA &&
1461: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1462: debug("Skipped %s key %s for RSA/MD5 server",
1463: key_type(id->key), id->filename);
1464: return (0);
1465: }
1.257 djm 1466: return 1;
1.225 markus 1467: }
1468:
1.20 markus 1469: int
1470: userauth_pubkey(Authctxt *authctxt)
1471: {
1.117 markus 1472: Identity *id;
1.20 markus 1473: int sent = 0;
1.256 djm 1474: char *fp;
1.20 markus 1475:
1.117 markus 1476: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1477: if (id->tried++)
1478: return (0);
1.127 markus 1479: /* move key to the end of the queue */
1.117 markus 1480: TAILQ_REMOVE(&authctxt->keys, id, next);
1481: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1482: /*
1483: * send a test message if we have the public key. for
1484: * encrypted keys we cannot do this and have to load the
1485: * private key instead
1486: */
1.200 djm 1487: if (id->key != NULL) {
1.225 markus 1488: if (try_identity(id)) {
1.256 djm 1489: if ((fp = sshkey_fingerprint(id->key,
1490: options.fingerprint_hash,
1491: SSH_FP_DEFAULT)) == NULL) {
1492: error("%s: sshkey_fingerprint failed",
1493: __func__);
1494: return 0;
1495: }
1496: debug("Offering public key: %s %s %s",
1497: sshkey_type(id->key), fp, id->filename);
1498: free(fp);
1.200 djm 1499: sent = send_pubkey_test(authctxt, id);
1500: }
1501: } else {
1.117 markus 1502: debug("Trying private key: %s", id->filename);
1.229 jcs 1503: id->key = load_identity_file(id);
1.117 markus 1504: if (id->key != NULL) {
1.225 markus 1505: if (try_identity(id)) {
1506: id->isprivate = 1;
1.200 djm 1507: sent = sign_and_send_pubkey(
1508: authctxt, id);
1509: }
1.117 markus 1510: key_free(id->key);
1511: id->key = NULL;
1.251 djm 1512: id->isprivate = 0;
1.51 markus 1513: }
1514: }
1.117 markus 1515: if (sent)
1516: return (sent);
1.28 markus 1517: }
1.117 markus 1518: return (0);
1.20 markus 1519: }
1520:
1.23 markus 1521: /*
1522: * Send userauth request message specifying keyboard-interactive method.
1523: */
1524: int
1525: userauth_kbdint(Authctxt *authctxt)
1526: {
1527: static int attempt = 0;
1528:
1529: if (attempt++ >= options.number_of_password_prompts)
1530: return 0;
1.82 markus 1531: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1532: if (attempt > 1 && !authctxt->info_req_seen) {
1533: debug3("userauth_kbdint: disable: no info_req_seen");
1534: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1535: return 0;
1536: }
1.23 markus 1537:
1538: debug2("userauth_kbdint");
1539: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1540: packet_put_cstring(authctxt->server_user);
1541: packet_put_cstring(authctxt->service);
1542: packet_put_cstring(authctxt->method->name);
1543: packet_put_cstring(""); /* lang */
1544: packet_put_cstring(options.kbd_interactive_devices ?
1545: options.kbd_interactive_devices : "");
1546: packet_send();
1547:
1548: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1549: return 1;
1550: }
1551:
1552: /*
1.46 markus 1553: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1554: */
1.218 markus 1555: int
1.261 markus 1556: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1557: {
1.260 markus 1558: Authctxt *authctxt = ssh->authctxt;
1.46 markus 1559: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1560: u_int num_prompts, i;
1.23 markus 1561: int echo = 0;
1562:
1563: debug2("input_userauth_info_req");
1564:
1565: if (authctxt == NULL)
1566: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1567:
1568: authctxt->info_req_seen = 1;
1.23 markus 1569:
1570: name = packet_get_string(NULL);
1571: inst = packet_get_string(NULL);
1572: lang = packet_get_string(NULL);
1573: if (strlen(name) > 0)
1.116 itojun 1574: logit("%s", name);
1.23 markus 1575: if (strlen(inst) > 0)
1.116 itojun 1576: logit("%s", inst);
1.197 djm 1577: free(name);
1578: free(inst);
1579: free(lang);
1.23 markus 1580:
1581: num_prompts = packet_get_int();
1582: /*
1583: * Begin to build info response packet based on prompts requested.
1584: * We commit to providing the correct number of responses, so if
1585: * further on we run into a problem that prevents this, we have to
1586: * be sure and clean this up and send a correct error response.
1587: */
1588: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1589: packet_put_int(num_prompts);
1590:
1.73 markus 1591: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1592: for (i = 0; i < num_prompts; i++) {
1593: prompt = packet_get_string(NULL);
1594: echo = packet_get_char();
1595:
1.77 markus 1596: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1597:
1.49 markus 1598: packet_put_cstring(response);
1.204 djm 1599: explicit_bzero(response, strlen(response));
1.197 djm 1600: free(response);
1601: free(prompt);
1.23 markus 1602: }
1.90 markus 1603: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1604:
1.85 markus 1605: packet_add_padding(64);
1.23 markus 1606: packet_send();
1.218 markus 1607: return 0;
1.68 markus 1608: }
1609:
1.100 markus 1610: static int
1.223 djm 1611: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1612: const u_char *data, size_t datalen)
1.100 markus 1613: {
1.223 djm 1614: struct sshbuf *b;
1.101 markus 1615: struct stat st;
1.100 markus 1616: pid_t pid;
1.223 djm 1617: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1618: u_char rversion = 0, version = 2;
1619: void (*osigchld)(int);
1.100 markus 1620:
1.223 djm 1621: *sigp = NULL;
1622: *lenp = 0;
1.100 markus 1623:
1.101 markus 1624: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1625: error("%s: not installed: %s", __func__, strerror(errno));
1626: return -1;
1627: }
1628: if (fflush(stdout) != 0) {
1629: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1630: return -1;
1631: }
1.100 markus 1632: if (pipe(to) < 0) {
1.223 djm 1633: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1634: return -1;
1635: }
1636: if (pipe(from) < 0) {
1.223 djm 1637: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1638: return -1;
1639: }
1640: if ((pid = fork()) < 0) {
1.223 djm 1641: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1642: return -1;
1643: }
1.223 djm 1644: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1645: if (pid == 0) {
1.174 dtucker 1646: /* keep the socket on exec */
1.223 djm 1647: fcntl(sock, F_SETFD, 0);
1.155 markus 1648: permanently_drop_suid(getuid());
1.100 markus 1649: close(from[0]);
1650: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1651: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1652: close(to[1]);
1653: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1654: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1655: close(from[1]);
1656: close(to[0]);
1.223 djm 1657: /* Close everything but stdio and the socket */
1658: for (i = STDERR_FILENO + 1; i < sock; i++)
1659: close(i);
1660: closefrom(sock + 1);
1661: debug3("%s: [child] pid=%ld, exec %s",
1662: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1663: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1664: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1665: strerror(errno));
1666: }
1667: close(from[1]);
1668: close(to[0]);
1669:
1.223 djm 1670: if ((b = sshbuf_new()) == NULL)
1671: fatal("%s: sshbuf_new failed", __func__);
1672: /* send # of sock, data to be signed */
1.253 djm 1673: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 1674: (r = sshbuf_put_string(b, data, datalen)) != 0)
1675: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1676: if (ssh_msg_send(to[1], version, b) == -1)
1677: fatal("%s: couldn't send request", __func__);
1678: sshbuf_reset(b);
1679: r = ssh_msg_recv(from[0], b);
1.101 markus 1680: close(from[0]);
1681: close(to[1]);
1.223 djm 1682: if (r < 0) {
1683: error("%s: no reply", __func__);
1684: goto fail;
1685: }
1.101 markus 1686:
1.223 djm 1687: errno = 0;
1688: while (waitpid(pid, &status, 0) < 0) {
1689: if (errno != EINTR) {
1690: error("%s: waitpid %ld: %s",
1691: __func__, (long)pid, strerror(errno));
1692: goto fail;
1693: }
1694: }
1695: if (!WIFEXITED(status)) {
1696: error("%s: exited abnormally", __func__);
1697: goto fail;
1698: }
1699: if (WEXITSTATUS(status) != 0) {
1700: error("%s: exited with status %d",
1701: __func__, WEXITSTATUS(status));
1702: goto fail;
1703: }
1704: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1705: error("%s: buffer error: %s", __func__, ssh_err(r));
1706: goto fail;
1707: }
1708: if (rversion != version) {
1709: error("%s: bad version", __func__);
1710: goto fail;
1711: }
1712: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1713: error("%s: buffer error: %s", __func__, ssh_err(r));
1714: fail:
1715: signal(SIGCHLD, osigchld);
1716: sshbuf_free(b);
1.100 markus 1717: return -1;
1718: }
1.223 djm 1719: signal(SIGCHLD, osigchld);
1720: sshbuf_free(b);
1.100 markus 1721:
1722: return 0;
1723: }
1724:
1.68 markus 1725: int
1726: userauth_hostbased(Authctxt *authctxt)
1727: {
1.223 djm 1728: struct ssh *ssh = active_state;
1729: struct sshkey *private = NULL;
1730: struct sshbuf *b = NULL;
1731: u_char *sig = NULL, *keyblob = NULL;
1732: char *fp = NULL, *chost = NULL, *lname = NULL;
1733: size_t siglen = 0, keylen = 0;
1734: int i, r, success = 0;
1735:
1736: if (authctxt->ktypes == NULL) {
1737: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1738: authctxt->ktypes = authctxt->oktypes;
1739: }
1.213 djm 1740:
1.223 djm 1741: /*
1742: * Work through each listed type pattern in HostbasedKeyTypes,
1743: * trying each hostkey that matches the type in turn.
1744: */
1745: for (;;) {
1746: if (authctxt->active_ktype == NULL)
1747: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1748: if (authctxt->active_ktype == NULL ||
1749: *authctxt->active_ktype == '\0')
1750: break;
1751: debug3("%s: trying key type %s", __func__,
1752: authctxt->active_ktype);
1.68 markus 1753:
1.223 djm 1754: /* check for a useful key */
1755: private = NULL;
1756: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1757: if (authctxt->sensitive->keys[i] == NULL ||
1758: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1759: continue;
1760: if (match_pattern_list(
1761: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1762: authctxt->active_ktype, 0) != 1)
1.223 djm 1763: continue;
1.68 markus 1764: /* we take and free the key */
1.223 djm 1765: private = authctxt->sensitive->keys[i];
1766: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1767: break;
1768: }
1.223 djm 1769: /* Found one */
1770: if (private != NULL)
1771: break;
1772: /* No more keys of this type; advance */
1773: authctxt->active_ktype = NULL;
1.68 markus 1774: }
1.223 djm 1775: if (private == NULL) {
1776: free(authctxt->oktypes);
1777: authctxt->oktypes = authctxt->ktypes = NULL;
1778: authctxt->active_ktype = NULL;
1.109 markus 1779: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1780: goto out;
1.68 markus 1781: }
1.211 djm 1782:
1.223 djm 1783: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1784: SSH_FP_DEFAULT)) == NULL) {
1785: error("%s: sshkey_fingerprint failed", __func__);
1786: goto out;
1.68 markus 1787: }
1.223 djm 1788: debug("%s: trying hostkey %s %s",
1789: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1790:
1.84 markus 1791: /* figure out a name for the client host */
1.223 djm 1792: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1793: error("%s: cannot get local ipaddr/name", __func__);
1794: goto out;
1.84 markus 1795: }
1.223 djm 1796:
1797: /* XXX sshbuf_put_stringf? */
1798: xasprintf(&chost, "%s.", lname);
1799: debug2("%s: chost %s", __func__, chost);
1.84 markus 1800:
1.68 markus 1801: /* construct data */
1.223 djm 1802: if ((b = sshbuf_new()) == NULL) {
1803: error("%s: sshbuf_new failed", __func__);
1804: goto out;
1805: }
1806: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1807: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1808: goto out;
1809: }
1810: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1811: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1812: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 1813: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 1814: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1815: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1816: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1817: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1818: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1819: error("%s: buffer error: %s", __func__, ssh_err(r));
1820: goto out;
1821: }
1822:
1.68 markus 1823: #ifdef DEBUG_PK
1.223 djm 1824: sshbuf_dump(b, stderr);
1.68 markus 1825: #endif
1.223 djm 1826: if (authctxt->sensitive->external_keysign)
1827: r = ssh_keysign(private, &sig, &siglen,
1828: sshbuf_ptr(b), sshbuf_len(b));
1829: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1830: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1831: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1832: if (r != 0) {
1833: error("sign using hostkey %s %s failed",
1834: sshkey_ssh_name(private), fp);
1835: goto out;
1836: }
1837: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1838: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1839: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1840: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1841: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1842: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1843: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1844: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1845: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1846: (r = sshpkt_send(ssh)) != 0) {
1847: error("%s: packet error: %s", __func__, ssh_err(r));
1848: goto out;
1849: }
1850: success = 1;
1851:
1852: out:
1853: if (sig != NULL) {
1854: explicit_bzero(sig, siglen);
1855: free(sig);
1.68 markus 1856: }
1.223 djm 1857: free(keyblob);
1858: free(lname);
1859: free(fp);
1.197 djm 1860: free(chost);
1.223 djm 1861: sshkey_free(private);
1862: sshbuf_free(b);
1.68 markus 1863:
1.223 djm 1864: return success;
1.23 markus 1865: }
1.170 djm 1866:
1.20 markus 1867: /* find auth method */
1868:
1869: /*
1870: * given auth method name, if configurable options permit this method fill
1871: * in auth_ident field and return true, otherwise return false.
1872: */
1.76 itojun 1873: static int
1.20 markus 1874: authmethod_is_enabled(Authmethod *method)
1875: {
1876: if (method == NULL)
1877: return 0;
1878: /* return false if options indicate this method is disabled */
1879: if (method->enabled == NULL || *method->enabled == 0)
1880: return 0;
1881: /* return false if batch mode is enabled but method needs interactive mode */
1882: if (method->batch_flag != NULL && *method->batch_flag != 0)
1883: return 0;
1884: return 1;
1885: }
1886:
1.76 itojun 1887: static Authmethod *
1.20 markus 1888: authmethod_lookup(const char *name)
1.1 markus 1889: {
1.20 markus 1890: Authmethod *method = NULL;
1891: if (name != NULL)
1892: for (method = authmethods; method->name != NULL; method++)
1893: if (strcmp(name, method->name) == 0)
1894: return method;
1895: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1896: return NULL;
1897: }
1.1 markus 1898:
1.53 markus 1899: /* XXX internal state */
1900: static Authmethod *current = NULL;
1901: static char *supported = NULL;
1902: static char *preferred = NULL;
1.105 deraadt 1903:
1.20 markus 1904: /*
1905: * Given the authentication method list sent by the server, return the
1906: * next method we should try. If the server initially sends a nil list,
1.67 markus 1907: * use a built-in default list.
1.41 stevesk 1908: */
1.76 itojun 1909: static Authmethod *
1.20 markus 1910: authmethod_get(char *authlist)
1911: {
1.53 markus 1912: char *name = NULL;
1.97 markus 1913: u_int next;
1.41 stevesk 1914:
1.20 markus 1915: /* Use a suitable default if we're passed a nil list. */
1916: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1917: authlist = options.preferred_authentications;
1.20 markus 1918:
1.53 markus 1919: if (supported == NULL || strcmp(authlist, supported) != 0) {
1920: debug3("start over, passed a different list %s", authlist);
1.197 djm 1921: free(supported);
1.53 markus 1922: supported = xstrdup(authlist);
1923: preferred = options.preferred_authentications;
1924: debug3("preferred %s", preferred);
1925: current = NULL;
1926: } else if (current != NULL && authmethod_is_enabled(current))
1927: return current;
1.20 markus 1928:
1.53 markus 1929: for (;;) {
1930: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1931: debug("No more authentication methods to try.");
1.53 markus 1932: current = NULL;
1933: return NULL;
1934: }
1935: preferred += next;
1.23 markus 1936: debug3("authmethod_lookup %s", name);
1.53 markus 1937: debug3("remaining preferred: %s", preferred);
1938: if ((current = authmethod_lookup(name)) != NULL &&
1939: authmethod_is_enabled(current)) {
1.23 markus 1940: debug3("authmethod_is_enabled %s", name);
1.109 markus 1941: debug("Next authentication method: %s", name);
1.197 djm 1942: free(name);
1.53 markus 1943: return current;
1.23 markus 1944: }
1.198 dtucker 1945: free(name);
1.1 markus 1946: }
1.53 markus 1947: }
1.1 markus 1948:
1.79 stevesk 1949: static char *
1.53 markus 1950: authmethods_get(void)
1951: {
1952: Authmethod *method = NULL;
1.93 markus 1953: Buffer b;
1954: char *list;
1.27 provos 1955:
1.93 markus 1956: buffer_init(&b);
1.53 markus 1957: for (method = authmethods; method->name != NULL; method++) {
1958: if (authmethod_is_enabled(method)) {
1.93 markus 1959: if (buffer_len(&b) > 0)
1960: buffer_append(&b, ",", 1);
1961: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1962: }
1963: }
1.242 djm 1964: if ((list = sshbuf_dup_string(&b)) == NULL)
1965: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1966: buffer_free(&b);
1967: return list;
1.1 markus 1968: }
1.170 djm 1969:
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