Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.229
1.229 ! jcs 1: /* $OpenBSD: sshconnect2.c,v 1.228 2015/10/13 16:15:21 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
1.170 djm 4: * Copyright (c) 2008 Damien Miller. All rights reserved.
1.1 markus 5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.145 stevesk 27: #include <sys/types.h>
1.160 deraadt 28: #include <sys/socket.h>
1.145 stevesk 29: #include <sys/wait.h>
1.144 stevesk 30: #include <sys/queue.h>
1.146 stevesk 31: #include <sys/stat.h>
1.156 stevesk 32:
33: #include <errno.h>
1.174 dtucker 34: #include <fcntl.h>
1.164 jolan 35: #include <netdb.h>
1.159 stevesk 36: #include <stdio.h>
1.158 stevesk 37: #include <string.h>
1.160 deraadt 38: #include <signal.h>
39: #include <pwd.h>
1.157 stevesk 40: #include <unistd.h>
1.166 djm 41: #include <vis.h>
1.1 markus 42:
1.160 deraadt 43: #include "xmalloc.h"
1.1 markus 44: #include "ssh.h"
1.37 markus 45: #include "ssh2.h"
1.1 markus 46: #include "buffer.h"
47: #include "packet.h"
48: #include "compat.h"
1.37 markus 49: #include "cipher.h"
1.160 deraadt 50: #include "key.h"
1.1 markus 51: #include "kex.h"
52: #include "myproposal.h"
53: #include "sshconnect.h"
54: #include "authfile.h"
1.57 provos 55: #include "dh.h"
1.17 markus 56: #include "authfd.h"
1.37 markus 57: #include "log.h"
1.210 millert 58: #include "misc.h"
1.37 markus 59: #include "readconf.h"
1.53 markus 60: #include "match.h"
1.61 markus 61: #include "dispatch.h"
1.68 markus 62: #include "canohost.h"
1.100 markus 63: #include "msg.h"
64: #include "pathnames.h"
1.154 markus 65: #include "uidswap.h"
1.186 djm 66: #include "hostfile.h"
1.214 djm 67: #include "ssherr.h"
1.22 provos 68:
1.121 markus 69: #ifdef GSSAPI
70: #include "ssh-gss.h"
71: #endif
72:
1.1 markus 73: /* import */
74: extern char *client_version_string;
75: extern char *server_version_string;
76: extern Options options;
77:
78: /*
79: * SSH2 key exchange
80: */
81:
1.32 markus 82: u_char *session_id2 = NULL;
1.120 markus 83: u_int session_id2_len = 0;
1.1 markus 84:
1.61 markus 85: char *xxx_host;
86: struct sockaddr *xxx_hostaddr;
87:
1.76 itojun 88: static int
1.219 markus 89: verify_host_key_callback(Key *hostkey, struct ssh *ssh)
1.61 markus 90: {
1.75 markus 91: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 92: fatal("Host key verification failed.");
1.61 markus 93: return 0;
94: }
95:
1.186 djm 96: static char *
97: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
98: {
99: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
100: size_t maxlen;
101: struct hostkeys *hostkeys;
102: int ktype;
1.188 djm 103: u_int i;
1.186 djm 104:
105: /* Find all hostkeys for this hostname */
106: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
107: hostkeys = init_hostkeys();
1.188 djm 108: for (i = 0; i < options.num_user_hostfiles; i++)
109: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
110: for (i = 0; i < options.num_system_hostfiles; i++)
111: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 112:
113: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
114: maxlen = strlen(avail) + 1;
115: first = xmalloc(maxlen);
116: last = xmalloc(maxlen);
117: *first = *last = '\0';
118:
119: #define ALG_APPEND(to, from) \
120: do { \
121: if (*to != '\0') \
122: strlcat(to, ",", maxlen); \
123: strlcat(to, from, maxlen); \
124: } while (0)
125:
126: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 127: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 128: fatal("%s: unknown alg %s", __func__, alg);
129: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 130: sshkey_type_plain(ktype), NULL))
1.186 djm 131: ALG_APPEND(first, alg);
132: else
133: ALG_APPEND(last, alg);
134: }
135: #undef ALG_APPEND
1.216 djm 136: xasprintf(&ret, "%s%s%s", first,
137: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 138: if (*first != '\0')
139: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
140:
1.197 djm 141: free(first);
142: free(last);
143: free(hostname);
144: free(oavail);
1.186 djm 145: free_hostkeys(hostkeys);
146:
147: return ret;
148: }
149:
1.1 markus 150: void
1.186 djm 151: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 152: {
1.205 markus 153: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.219 markus 154: struct kex *kex;
1.221 markus 155: int r;
1.61 markus 156:
157: xxx_host = host;
158: xxx_hostaddr = hostaddr;
1.22 provos 159:
1.226 djm 160: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
161: options.kex_algorithms);
1.60 stevesk 162: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.226 djm 163: compat_cipher_proposal(options.ciphers);
1.60 stevesk 164: myproposal[PROPOSAL_ENC_ALGS_STOC] =
1.226 djm 165: compat_cipher_proposal(options.ciphers);
1.22 provos 166: if (options.compression) {
1.47 markus 167: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 168: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 169: } else {
1.47 markus 170: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 171: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 172: }
1.226 djm 173: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
174: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
175: if (options.hostkeyalgorithms != NULL) {
176: if (kex_assemble_names(KEX_DEFAULT_PK_ALG,
177: &options.hostkeyalgorithms) != 0)
178: fatal("%s: kex_assemble_namelist", __func__);
1.88 deraadt 179: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 180: compat_pkalg_proposal(options.hostkeyalgorithms);
1.226 djm 181: } else {
1.225 markus 182: /* Enforce default */
183: options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
1.186 djm 184: /* Prefer algorithms that we already have keys for */
185: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 186: compat_pkalg_proposal(
187: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 188: }
1.115 markus 189:
1.196 dtucker 190: if (options.rekey_limit || options.rekey_interval)
191: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
192: (time_t)options.rekey_interval);
1.22 provos 193:
1.65 markus 194: /* start key exchange */
1.221 markus 195: if ((r = kex_setup(active_state, myproposal)) != 0)
196: fatal("kex_setup: %s", ssh_err(r));
1.219 markus 197: kex = active_state->kex;
1.207 markus 198: #ifdef WITH_OPENSSL
1.111 markus 199: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 200: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.111 markus 201: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 202: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 203: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.207 markus 204: #endif
1.199 markus 205: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 206: kex->client_version_string=client_version_string;
207: kex->server_version_string=server_version_string;
1.75 markus 208: kex->verify_host_key=&verify_host_key_callback;
1.22 provos 209:
1.219 markus 210: dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
1.173 andreas 211:
212: if (options.use_roaming && !kex->roaming) {
213: debug("Roaming not allowed by server");
214: options.use_roaming = 0;
215: }
1.62 markus 216:
217: session_id2 = kex->session_id;
218: session_id2_len = kex->session_id_len;
1.22 provos 219:
220: #ifdef DEBUG_KEXDH
221: /* send 1st encrypted/maced/compressed message */
222: packet_start(SSH2_MSG_IGNORE);
223: packet_put_cstring("markus");
224: packet_send();
225: packet_write_wait();
226: #endif
1.1 markus 227: }
1.11 markus 228:
1.1 markus 229: /*
230: * Authenticate user
231: */
1.20 markus 232:
1.214 djm 233: typedef struct cauthctxt Authctxt;
234: typedef struct cauthmethod Authmethod;
1.117 markus 235: typedef struct identity Identity;
236: typedef struct idlist Idlist;
1.20 markus 237:
1.117 markus 238: struct identity {
239: TAILQ_ENTRY(identity) next;
1.214 djm 240: int agent_fd; /* >=0 if agent supports key */
241: struct sshkey *key; /* public/private key */
1.117 markus 242: char *filename; /* comment for agent-only keys */
243: int tried;
244: int isprivate; /* key points to the private key */
1.191 dtucker 245: int userprovided;
1.117 markus 246: };
247: TAILQ_HEAD(idlist, identity);
1.20 markus 248:
1.214 djm 249: struct cauthctxt {
1.20 markus 250: const char *server_user;
1.68 markus 251: const char *local_user;
1.20 markus 252: const char *host;
253: const char *service;
1.214 djm 254: struct cauthmethod *method;
1.183 djm 255: sig_atomic_t success;
1.51 markus 256: char *authlist;
1.214 djm 257: int attempt;
1.68 markus 258: /* pubkey */
1.214 djm 259: struct idlist keys;
260: int agent_fd;
1.68 markus 261: /* hostbased */
1.100 markus 262: Sensitive *sensitive;
1.223 djm 263: char *oktypes, *ktypes;
264: const char *active_ktype;
1.82 markus 265: /* kbd-interactive */
266: int info_req_seen;
1.121 markus 267: /* generic */
268: void *methoddata;
1.20 markus 269: };
1.214 djm 270:
271: struct cauthmethod {
1.20 markus 272: char *name; /* string to compare against server's list */
273: int (*userauth)(Authctxt *authctxt);
1.170 djm 274: void (*cleanup)(Authctxt *authctxt);
1.20 markus 275: int *enabled; /* flag in option struct that enables method */
276: int *batch_flag; /* flag in option struct that disables method */
277: };
278:
1.218 markus 279: int input_userauth_success(int, u_int32_t, void *);
280: int input_userauth_success_unexpected(int, u_int32_t, void *);
281: int input_userauth_failure(int, u_int32_t, void *);
282: int input_userauth_banner(int, u_int32_t, void *);
283: int input_userauth_error(int, u_int32_t, void *);
284: int input_userauth_info_req(int, u_int32_t, void *);
285: int input_userauth_pk_ok(int, u_int32_t, void *);
286: int input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 287:
288: int userauth_none(Authctxt *);
289: int userauth_pubkey(Authctxt *);
290: int userauth_passwd(Authctxt *);
291: int userauth_kbdint(Authctxt *);
292: int userauth_hostbased(Authctxt *);
1.20 markus 293:
1.121 markus 294: #ifdef GSSAPI
295: int userauth_gssapi(Authctxt *authctxt);
1.218 markus 296: int input_gssapi_response(int type, u_int32_t, void *);
297: int input_gssapi_token(int type, u_int32_t, void *);
298: int input_gssapi_hash(int type, u_int32_t, void *);
299: int input_gssapi_error(int, u_int32_t, void *);
300: int input_gssapi_errtok(int, u_int32_t, void *);
1.121 markus 301: #endif
302:
1.86 itojun 303: void userauth(Authctxt *, char *);
1.51 markus 304:
1.117 markus 305: static int sign_and_send_pubkey(Authctxt *, Identity *);
306: static void pubkey_prepare(Authctxt *);
307: static void pubkey_cleanup(Authctxt *);
1.229 ! jcs 308: static Key *load_identity_file(Identity *);
1.76 itojun 309:
310: static Authmethod *authmethod_get(char *authlist);
311: static Authmethod *authmethod_lookup(const char *name);
312: static char *authmethods_get(void);
1.20 markus 313:
314: Authmethod authmethods[] = {
1.121 markus 315: #ifdef GSSAPI
1.132 markus 316: {"gssapi-with-mic",
1.121 markus 317: userauth_gssapi,
1.170 djm 318: NULL,
1.121 markus 319: &options.gss_authentication,
320: NULL},
321: #endif
1.81 markus 322: {"hostbased",
323: userauth_hostbased,
1.170 djm 324: NULL,
1.81 markus 325: &options.hostbased_authentication,
326: NULL},
1.20 markus 327: {"publickey",
328: userauth_pubkey,
1.170 djm 329: NULL,
1.28 markus 330: &options.pubkey_authentication,
1.20 markus 331: NULL},
1.81 markus 332: {"keyboard-interactive",
333: userauth_kbdint,
1.170 djm 334: NULL,
1.81 markus 335: &options.kbd_interactive_authentication,
336: &options.batch_mode},
1.20 markus 337: {"password",
338: userauth_passwd,
1.170 djm 339: NULL,
1.20 markus 340: &options.password_authentication,
1.23 markus 341: &options.batch_mode},
342: {"none",
343: userauth_none,
344: NULL,
1.170 djm 345: NULL,
1.23 markus 346: NULL},
1.170 djm 347: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 348: };
349:
350: void
1.68 markus 351: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 352: Sensitive *sensitive)
1.20 markus 353: {
354: Authctxt authctxt;
355: int type;
1.39 markus 356:
1.73 markus 357: if (options.challenge_response_authentication)
1.39 markus 358: options.kbd_interactive_authentication = 1;
1.20 markus 359:
360: packet_start(SSH2_MSG_SERVICE_REQUEST);
361: packet_put_cstring("ssh-userauth");
362: packet_send();
1.108 markus 363: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 364: packet_write_wait();
1.91 markus 365: type = packet_read();
1.108 markus 366: if (type != SSH2_MSG_SERVICE_ACCEPT)
367: fatal("Server denied authentication request: %d", type);
1.20 markus 368: if (packet_remaining() > 0) {
1.91 markus 369: char *reply = packet_get_string(NULL);
1.108 markus 370: debug2("service_accept: %s", reply);
1.197 djm 371: free(reply);
1.20 markus 372: } else {
1.109 markus 373: debug2("buggy server: service_accept w/o service");
1.20 markus 374: }
1.90 markus 375: packet_check_eom();
1.108 markus 376: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 377:
1.53 markus 378: if (options.preferred_authentications == NULL)
379: options.preferred_authentications = authmethods_get();
380:
1.20 markus 381: /* setup authentication context */
1.82 markus 382: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 383: pubkey_prepare(&authctxt);
1.20 markus 384: authctxt.server_user = server_user;
1.68 markus 385: authctxt.local_user = local_user;
1.20 markus 386: authctxt.host = host;
387: authctxt.service = "ssh-connection"; /* service name */
388: authctxt.success = 0;
1.23 markus 389: authctxt.method = authmethod_lookup("none");
1.51 markus 390: authctxt.authlist = NULL;
1.121 markus 391: authctxt.methoddata = NULL;
1.100 markus 392: authctxt.sensitive = sensitive;
1.223 djm 393: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 394: authctxt.info_req_seen = 0;
1.215 djm 395: authctxt.agent_fd = -1;
1.23 markus 396: if (authctxt.method == NULL)
397: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 398:
399: /* initial userauth request */
1.23 markus 400: userauth_none(&authctxt);
1.20 markus 401:
1.65 markus 402: dispatch_init(&input_userauth_error);
1.20 markus 403: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
404: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 405: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 406: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
407:
1.117 markus 408: pubkey_cleanup(&authctxt);
1.119 markus 409: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
410:
1.109 markus 411: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 412: }
1.119 markus 413:
1.20 markus 414: void
1.51 markus 415: userauth(Authctxt *authctxt, char *authlist)
416: {
1.170 djm 417: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
418: authctxt->method->cleanup(authctxt);
419:
1.197 djm 420: free(authctxt->methoddata);
421: authctxt->methoddata = NULL;
1.51 markus 422: if (authlist == NULL) {
423: authlist = authctxt->authlist;
424: } else {
1.197 djm 425: free(authctxt->authlist);
1.51 markus 426: authctxt->authlist = authlist;
427: }
428: for (;;) {
429: Authmethod *method = authmethod_get(authlist);
430: if (method == NULL)
431: fatal("Permission denied (%s).", authlist);
432: authctxt->method = method;
1.119 markus 433:
434: /* reset the per method handler */
435: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
436: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
437:
438: /* and try new method */
1.51 markus 439: if (method->userauth(authctxt) != 0) {
440: debug2("we sent a %s packet, wait for reply", method->name);
441: break;
442: } else {
443: debug2("we did not send a packet, disable method");
444: method->enabled = NULL;
445: }
446: }
447: }
1.105 deraadt 448:
1.169 djm 449: /* ARGSUSED */
1.218 markus 450: int
1.92 markus 451: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 452: {
1.35 markus 453: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 454: "type %d", type);
1.218 markus 455: return 0;
1.35 markus 456: }
1.105 deraadt 457:
1.169 djm 458: /* ARGSUSED */
1.218 markus 459: int
1.92 markus 460: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 461: {
1.166 djm 462: char *msg, *raw, *lang;
463: u_int len;
1.126 deraadt 464:
1.35 markus 465: debug3("input_userauth_banner");
1.166 djm 466: raw = packet_get_string(&len);
1.35 markus 467: lang = packet_get_string(NULL);
1.167 markus 468: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 469: if (len > 65536)
470: len = 65536;
1.168 deraadt 471: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 472: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 473: fprintf(stderr, "%s", msg);
1.197 djm 474: free(msg);
1.166 djm 475: }
1.197 djm 476: free(raw);
477: free(lang);
1.218 markus 478: return 0;
1.20 markus 479: }
1.105 deraadt 480:
1.169 djm 481: /* ARGSUSED */
1.218 markus 482: int
1.92 markus 483: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 484: {
485: Authctxt *authctxt = ctxt;
1.172 djm 486:
1.20 markus 487: if (authctxt == NULL)
488: fatal("input_userauth_success: no authentication context");
1.197 djm 489: free(authctxt->authlist);
490: authctxt->authlist = NULL;
1.172 djm 491: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
492: authctxt->method->cleanup(authctxt);
1.197 djm 493: free(authctxt->methoddata);
494: authctxt->methoddata = NULL;
1.20 markus 495: authctxt->success = 1; /* break out */
1.218 markus 496: return 0;
1.20 markus 497: }
1.105 deraadt 498:
1.218 markus 499: int
1.172 djm 500: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
501: {
502: Authctxt *authctxt = ctxt;
503:
504: if (authctxt == NULL)
505: fatal("%s: no authentication context", __func__);
506:
507: fatal("Unexpected authentication success during %s.",
508: authctxt->method->name);
1.218 markus 509: return 0;
1.172 djm 510: }
511:
1.169 djm 512: /* ARGSUSED */
1.218 markus 513: int
1.92 markus 514: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 515: {
516: Authctxt *authctxt = ctxt;
517: char *authlist = NULL;
518: int partial;
519:
520: if (authctxt == NULL)
521: fatal("input_userauth_failure: no authentication context");
522:
1.23 markus 523: authlist = packet_get_string(NULL);
1.20 markus 524: partial = packet_get_char();
1.90 markus 525: packet_check_eom();
1.20 markus 526:
1.193 markus 527: if (partial != 0) {
1.116 itojun 528: logit("Authenticated with partial success.");
1.193 markus 529: /* reset state */
530: pubkey_cleanup(authctxt);
531: pubkey_prepare(authctxt);
532: }
1.109 markus 533: debug("Authentications that can continue: %s", authlist);
1.20 markus 534:
1.51 markus 535: userauth(authctxt, authlist);
1.218 markus 536: return 0;
1.51 markus 537: }
1.169 djm 538:
539: /* ARGSUSED */
1.218 markus 540: int
1.92 markus 541: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 542: {
543: Authctxt *authctxt = ctxt;
544: Key *key = NULL;
1.117 markus 545: Identity *id = NULL;
1.51 markus 546: Buffer b;
1.96 markus 547: int pktype, sent = 0;
548: u_int alen, blen;
549: char *pkalg, *fp;
550: u_char *pkblob;
1.51 markus 551:
552: if (authctxt == NULL)
553: fatal("input_userauth_pk_ok: no authentication context");
554: if (datafellows & SSH_BUG_PKOK) {
555: /* this is similar to SSH_BUG_PKAUTH */
556: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
557: pkblob = packet_get_string(&blen);
558: buffer_init(&b);
559: buffer_append(&b, pkblob, blen);
560: pkalg = buffer_get_string(&b, &alen);
561: buffer_free(&b);
562: } else {
563: pkalg = packet_get_string(&alen);
564: pkblob = packet_get_string(&blen);
565: }
1.90 markus 566: packet_check_eom();
1.51 markus 567:
1.117 markus 568: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 569:
1.117 markus 570: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
571: debug("unknown pkalg %s", pkalg);
572: goto done;
573: }
574: if ((key = key_from_blob(pkblob, blen)) == NULL) {
575: debug("no key from blob. pkalg %s", pkalg);
576: goto done;
577: }
578: if (key->type != pktype) {
579: error("input_userauth_pk_ok: type mismatch "
580: "for decoded key (received %d, expected %d)",
581: key->type, pktype);
582: goto done;
583: }
1.222 djm 584: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
585: SSH_FP_DEFAULT)) == NULL)
586: goto done;
1.117 markus 587: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 588: free(fp);
1.117 markus 589:
1.127 markus 590: /*
591: * search keys in the reverse order, because last candidate has been
592: * moved to the end of the queue. this also avoids confusion by
593: * duplicate keys
594: */
1.136 henning 595: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 596: if (key_equal(key, id->key)) {
597: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 598: break;
599: }
1.117 markus 600: }
601: done:
1.51 markus 602: if (key != NULL)
603: key_free(key);
1.197 djm 604: free(pkalg);
605: free(pkblob);
1.51 markus 606:
1.106 deraadt 607: /* try another method if we did not send a packet */
1.51 markus 608: if (sent == 0)
609: userauth(authctxt, NULL);
1.218 markus 610: return 0;
1.20 markus 611: }
1.121 markus 612:
613: #ifdef GSSAPI
1.133 djm 614: int
1.121 markus 615: userauth_gssapi(Authctxt *authctxt)
616: {
617: Gssctxt *gssctxt = NULL;
1.128 avsm 618: static gss_OID_set gss_supported = NULL;
1.139 djm 619: static u_int mech = 0;
1.121 markus 620: OM_uint32 min;
621: int ok = 0;
622:
623: /* Try one GSSAPI method at a time, rather than sending them all at
624: * once. */
625:
1.128 avsm 626: if (gss_supported == NULL)
627: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 628:
629: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 630: while (mech < gss_supported->count && !ok) {
1.121 markus 631: /* My DER encoding requires length<128 */
1.128 avsm 632: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 633: ssh_gssapi_check_mechanism(&gssctxt,
634: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 635: ok = 1; /* Mechanism works */
636: } else {
637: mech++;
638: }
639: }
640:
1.161 djm 641: if (!ok)
1.139 djm 642: return 0;
1.121 markus 643:
644: authctxt->methoddata=(void *)gssctxt;
645:
646: packet_start(SSH2_MSG_USERAUTH_REQUEST);
647: packet_put_cstring(authctxt->server_user);
648: packet_put_cstring(authctxt->service);
649: packet_put_cstring(authctxt->method->name);
650:
651: packet_put_int(1);
652:
1.129 markus 653: packet_put_int((gss_supported->elements[mech].length) + 2);
654: packet_put_char(SSH_GSS_OIDTYPE);
655: packet_put_char(gss_supported->elements[mech].length);
656: packet_put_raw(gss_supported->elements[mech].elements,
657: gss_supported->elements[mech].length);
1.121 markus 658:
659: packet_send();
660:
661: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
662: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
663: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
664: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
665:
666: mech++; /* Move along to next candidate */
667:
668: return 1;
669: }
670:
1.130 markus 671: static OM_uint32
672: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
673: {
674: Authctxt *authctxt = ctxt;
675: Gssctxt *gssctxt = authctxt->methoddata;
676: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 677: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
678: gss_buffer_desc gssbuf;
1.132 markus 679: OM_uint32 status, ms, flags;
680: Buffer b;
1.133 djm 681:
1.130 markus 682: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 683: recv_tok, &send_tok, &flags);
1.130 markus 684:
685: if (send_tok.length > 0) {
686: if (GSS_ERROR(status))
687: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
688: else
689: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 690:
1.130 markus 691: packet_put_string(send_tok.value, send_tok.length);
692: packet_send();
693: gss_release_buffer(&ms, &send_tok);
694: }
1.133 djm 695:
1.130 markus 696: if (status == GSS_S_COMPLETE) {
1.132 markus 697: /* send either complete or MIC, depending on mechanism */
698: if (!(flags & GSS_C_INTEG_FLAG)) {
699: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
700: packet_send();
701: } else {
702: ssh_gssapi_buildmic(&b, authctxt->server_user,
703: authctxt->service, "gssapi-with-mic");
704:
705: gssbuf.value = buffer_ptr(&b);
706: gssbuf.length = buffer_len(&b);
1.133 djm 707:
1.132 markus 708: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 709:
1.132 markus 710: if (!GSS_ERROR(status)) {
711: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
712: packet_put_string(mic.value, mic.length);
1.133 djm 713:
1.132 markus 714: packet_send();
715: }
1.133 djm 716:
1.132 markus 717: buffer_free(&b);
718: gss_release_buffer(&ms, &mic);
1.133 djm 719: }
1.130 markus 720: }
1.133 djm 721:
1.130 markus 722: return status;
723: }
724:
1.169 djm 725: /* ARGSUSED */
1.220 djm 726: int
1.121 markus 727: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
728: {
729: Authctxt *authctxt = ctxt;
730: Gssctxt *gssctxt;
731: int oidlen;
732: char *oidv;
733:
734: if (authctxt == NULL)
735: fatal("input_gssapi_response: no authentication context");
736: gssctxt = authctxt->methoddata;
737:
738: /* Setup our OID */
739: oidv = packet_get_string(&oidlen);
740:
1.129 markus 741: if (oidlen <= 2 ||
742: oidv[0] != SSH_GSS_OIDTYPE ||
743: oidv[1] != oidlen - 2) {
1.197 djm 744: free(oidv);
1.129 markus 745: debug("Badly encoded mechanism OID received");
746: userauth(authctxt, NULL);
1.220 djm 747: return 0;
1.121 markus 748: }
1.129 markus 749:
750: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
751: fatal("Server returned different OID than expected");
1.121 markus 752:
753: packet_check_eom();
754:
1.197 djm 755: free(oidv);
1.121 markus 756:
1.130 markus 757: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 758: /* Start again with next method on list */
759: debug("Trying to start again");
760: userauth(authctxt, NULL);
1.220 djm 761: return 0;
1.121 markus 762: }
1.220 djm 763: return 0;
1.121 markus 764: }
765:
1.169 djm 766: /* ARGSUSED */
1.220 djm 767: int
1.121 markus 768: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
769: {
770: Authctxt *authctxt = ctxt;
771: gss_buffer_desc recv_tok;
1.130 markus 772: OM_uint32 status;
1.121 markus 773: u_int slen;
774:
775: if (authctxt == NULL)
776: fatal("input_gssapi_response: no authentication context");
777:
778: recv_tok.value = packet_get_string(&slen);
779: recv_tok.length = slen; /* safe typecast */
780:
781: packet_check_eom();
782:
1.130 markus 783: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 784:
1.197 djm 785: free(recv_tok.value);
1.121 markus 786:
787: if (GSS_ERROR(status)) {
788: /* Start again with the next method in the list */
789: userauth(authctxt, NULL);
1.220 djm 790: return 0;
1.121 markus 791: }
1.220 djm 792: return 0;
1.121 markus 793: }
794:
1.169 djm 795: /* ARGSUSED */
1.220 djm 796: int
1.121 markus 797: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
798: {
799: Authctxt *authctxt = ctxt;
800: Gssctxt *gssctxt;
801: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
802: gss_buffer_desc recv_tok;
1.194 djm 803: OM_uint32 ms;
1.123 deraadt 804: u_int len;
1.121 markus 805:
806: if (authctxt == NULL)
807: fatal("input_gssapi_response: no authentication context");
808: gssctxt = authctxt->methoddata;
809:
1.123 deraadt 810: recv_tok.value = packet_get_string(&len);
811: recv_tok.length = len;
1.121 markus 812:
813: packet_check_eom();
814:
815: /* Stick it into GSSAPI and see what it says */
1.194 djm 816: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 817: &recv_tok, &send_tok, NULL);
1.121 markus 818:
1.197 djm 819: free(recv_tok.value);
1.121 markus 820: gss_release_buffer(&ms, &send_tok);
821:
822: /* Server will be returning a failed packet after this one */
1.220 djm 823: return 0;
1.121 markus 824: }
825:
1.169 djm 826: /* ARGSUSED */
1.220 djm 827: int
1.121 markus 828: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
829: {
830: char *msg;
831: char *lang;
832:
1.194 djm 833: /* maj */(void)packet_get_int();
834: /* min */(void)packet_get_int();
1.121 markus 835: msg=packet_get_string(NULL);
836: lang=packet_get_string(NULL);
837:
838: packet_check_eom();
839:
1.143 stevesk 840: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 841: free(msg);
842: free(lang);
1.220 djm 843: return 0;
1.121 markus 844: }
845: #endif /* GSSAPI */
1.20 markus 846:
1.1 markus 847: int
1.23 markus 848: userauth_none(Authctxt *authctxt)
849: {
850: /* initial userauth request */
851: packet_start(SSH2_MSG_USERAUTH_REQUEST);
852: packet_put_cstring(authctxt->server_user);
853: packet_put_cstring(authctxt->service);
854: packet_put_cstring(authctxt->method->name);
855: packet_send();
856: return 1;
857: }
858:
859: int
1.20 markus 860: userauth_passwd(Authctxt *authctxt)
1.1 markus 861: {
1.6 markus 862: static int attempt = 0;
1.99 markus 863: char prompt[150];
1.1 markus 864: char *password;
1.175 dtucker 865: const char *host = options.host_key_alias ? options.host_key_alias :
866: authctxt->host;
1.6 markus 867:
1.13 todd 868: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 869: return 0;
1.13 todd 870:
1.87 deraadt 871: if (attempt != 1)
1.13 todd 872: error("Permission denied, please try again.");
1.1 markus 873:
1.43 itojun 874: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 875: authctxt->server_user, host);
1.1 markus 876: password = read_passphrase(prompt, 0);
877: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 878: packet_put_cstring(authctxt->server_user);
879: packet_put_cstring(authctxt->service);
1.23 markus 880: packet_put_cstring(authctxt->method->name);
1.1 markus 881: packet_put_char(0);
1.49 markus 882: packet_put_cstring(password);
1.204 djm 883: explicit_bzero(password, strlen(password));
1.197 djm 884: free(password);
1.85 markus 885: packet_add_padding(64);
1.1 markus 886: packet_send();
1.99 markus 887:
1.104 deraadt 888: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 889: &input_userauth_passwd_changereq);
890:
1.1 markus 891: return 1;
892: }
1.169 djm 893:
1.99 markus 894: /*
895: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
896: */
1.169 djm 897: /* ARGSUSED */
1.218 markus 898: int
1.153 djm 899: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 900: {
901: Authctxt *authctxt = ctxt;
902: char *info, *lang, *password = NULL, *retype = NULL;
903: char prompt[150];
1.175 dtucker 904: const char *host = options.host_key_alias ? options.host_key_alias :
905: authctxt->host;
1.99 markus 906:
907: debug2("input_userauth_passwd_changereq");
908:
909: if (authctxt == NULL)
910: fatal("input_userauth_passwd_changereq: "
911: "no authentication context");
912:
913: info = packet_get_string(NULL);
914: lang = packet_get_string(NULL);
915: if (strlen(info) > 0)
1.116 itojun 916: logit("%s", info);
1.197 djm 917: free(info);
918: free(lang);
1.99 markus 919: packet_start(SSH2_MSG_USERAUTH_REQUEST);
920: packet_put_cstring(authctxt->server_user);
921: packet_put_cstring(authctxt->service);
922: packet_put_cstring(authctxt->method->name);
923: packet_put_char(1); /* additional info */
1.104 deraadt 924: snprintf(prompt, sizeof(prompt),
1.99 markus 925: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 926: authctxt->server_user, host);
1.99 markus 927: password = read_passphrase(prompt, 0);
928: packet_put_cstring(password);
1.204 djm 929: explicit_bzero(password, strlen(password));
1.197 djm 930: free(password);
1.99 markus 931: password = NULL;
932: while (password == NULL) {
1.104 deraadt 933: snprintf(prompt, sizeof(prompt),
1.99 markus 934: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 935: authctxt->server_user, host);
1.99 markus 936: password = read_passphrase(prompt, RP_ALLOW_EOF);
937: if (password == NULL) {
938: /* bail out */
1.218 markus 939: return 0;
1.99 markus 940: }
1.104 deraadt 941: snprintf(prompt, sizeof(prompt),
1.99 markus 942: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 943: authctxt->server_user, host);
1.99 markus 944: retype = read_passphrase(prompt, 0);
945: if (strcmp(password, retype) != 0) {
1.204 djm 946: explicit_bzero(password, strlen(password));
1.197 djm 947: free(password);
1.116 itojun 948: logit("Mismatch; try again, EOF to quit.");
1.99 markus 949: password = NULL;
950: }
1.204 djm 951: explicit_bzero(retype, strlen(retype));
1.197 djm 952: free(retype);
1.99 markus 953: }
954: packet_put_cstring(password);
1.204 djm 955: explicit_bzero(password, strlen(password));
1.197 djm 956: free(password);
1.99 markus 957: packet_add_padding(64);
958: packet_send();
1.104 deraadt 959:
960: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 961: &input_userauth_passwd_changereq);
1.218 markus 962: return 0;
1.117 markus 963: }
964:
965: static int
1.214 djm 966: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
967: const u_char *data, size_t datalen, u_int compat)
1.117 markus 968: {
969: Key *prv;
970: int ret;
1.99 markus 971:
1.117 markus 972: /* the agent supports this key */
1.214 djm 973: if (id->agent_fd)
974: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
975: data, datalen, compat);
976:
1.117 markus 977: /*
978: * we have already loaded the private key or
979: * the private key is stored in external hardware
980: */
1.209 djm 981: if (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))
1.214 djm 982: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
983: compat));
1.117 markus 984: /* load the private key from the file */
1.229 ! jcs 985: if ((prv = load_identity_file(id)) == NULL)
1.214 djm 986: return (-1); /* XXX return decent error code */
987: ret = sshkey_sign(prv, sigp, lenp, data, datalen, compat);
988: sshkey_free(prv);
1.117 markus 989: return (ret);
1.51 markus 990: }
991:
1.76 itojun 992: static int
1.117 markus 993: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 994: {
995: Buffer b;
1.227 djm 996: Identity *private_id;
1.32 markus 997: u_char *blob, *signature;
1.214 djm 998: size_t slen;
1.227 djm 999: u_int bloblen, skip = 0;
1000: int matched, ret = -1, have_sig = 1;
1.182 djm 1001: char *fp;
1.1 markus 1002:
1.222 djm 1003: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1004: SSH_FP_DEFAULT)) == NULL)
1005: return 0;
1.227 djm 1006: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1007: free(fp);
1.51 markus 1008:
1.117 markus 1009: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1010: /* we cannot handle this key */
1.30 markus 1011: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1012: return 0;
1013: }
1.1 markus 1014: /* data to be signed */
1015: buffer_init(&b);
1.26 markus 1016: if (datafellows & SSH_OLD_SESSIONID) {
1017: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1018: skip = session_id2_len;
1.26 markus 1019: } else {
1.14 markus 1020: buffer_put_string(&b, session_id2, session_id2_len);
1021: skip = buffer_len(&b);
1022: }
1.1 markus 1023: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1024: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1025: buffer_put_cstring(&b,
1.30 markus 1026: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1027: "ssh-userauth" :
1.20 markus 1028: authctxt->service);
1.30 markus 1029: if (datafellows & SSH_BUG_PKAUTH) {
1030: buffer_put_char(&b, have_sig);
1031: } else {
1032: buffer_put_cstring(&b, authctxt->method->name);
1033: buffer_put_char(&b, have_sig);
1.117 markus 1034: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1035: }
1.1 markus 1036: buffer_put_string(&b, blob, bloblen);
1037:
1.227 djm 1038: /*
1039: * If the key is an certificate, try to find a matching private key
1040: * and use it to complete the signature.
1041: * If no such private key exists, return failure and continue with
1042: * other methods of authentication.
1043: */
1044: if (key_is_cert(id->key)) {
1045: matched = 0;
1046: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1047: if (sshkey_equal_public(id->key, private_id->key) &&
1048: id->key->type != private_id->key->type) {
1049: id = private_id;
1050: matched = 1;
1051: break;
1052: }
1053: }
1054: if (matched) {
1055: debug2("%s: using private key \"%s\"%s for "
1056: "certificate", __func__, id->filename,
1057: id->agent_fd != -1 ? " from agent" : "");
1058: } else {
1059: /* XXX maybe verbose/error? */
1060: debug("%s: no private key for certificate "
1061: "\"%s\"", __func__, id->filename);
1062: free(blob);
1063: buffer_free(&b);
1064: return 0;
1065: }
1066: }
1067:
1.1 markus 1068: /* generate signature */
1.117 markus 1069: ret = identity_sign(id, &signature, &slen,
1.214 djm 1070: buffer_ptr(&b), buffer_len(&b), datafellows);
1071: if (ret != 0) {
1.197 djm 1072: free(blob);
1.17 markus 1073: buffer_free(&b);
1074: return 0;
1075: }
1.28 markus 1076: #ifdef DEBUG_PK
1.1 markus 1077: buffer_dump(&b);
1078: #endif
1.30 markus 1079: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1080: buffer_clear(&b);
1081: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1082: skip = session_id2_len;
1.10 markus 1083: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1084: buffer_put_cstring(&b, authctxt->server_user);
1085: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1086: buffer_put_cstring(&b, authctxt->method->name);
1087: buffer_put_char(&b, have_sig);
1.30 markus 1088: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1089: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1090: buffer_put_string(&b, blob, bloblen);
1091: }
1.197 djm 1092: free(blob);
1.51 markus 1093:
1.1 markus 1094: /* append signature */
1095: buffer_put_string(&b, signature, slen);
1.197 djm 1096: free(signature);
1.1 markus 1097:
1098: /* skip session id and packet type */
1.14 markus 1099: if (buffer_len(&b) < skip + 1)
1.20 markus 1100: fatal("userauth_pubkey: internal error");
1.14 markus 1101: buffer_consume(&b, skip + 1);
1.1 markus 1102:
1103: /* put remaining data from buffer into packet */
1104: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1105: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1106: buffer_free(&b);
1107: packet_send();
1.17 markus 1108:
1109: return 1;
1.16 markus 1110: }
1111:
1.76 itojun 1112: static int
1.117 markus 1113: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1114: {
1.51 markus 1115: u_char *blob;
1.97 markus 1116: u_int bloblen, have_sig = 0;
1.20 markus 1117:
1.51 markus 1118: debug3("send_pubkey_test");
1.16 markus 1119:
1.117 markus 1120: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1121: /* we cannot handle this key */
1122: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1123: return 0;
1124: }
1.51 markus 1125: /* register callback for USERAUTH_PK_OK message */
1126: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1127:
1128: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1129: packet_put_cstring(authctxt->server_user);
1130: packet_put_cstring(authctxt->service);
1131: packet_put_cstring(authctxt->method->name);
1132: packet_put_char(have_sig);
1133: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1134: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1135: packet_put_string(blob, bloblen);
1.197 djm 1136: free(blob);
1.51 markus 1137: packet_send();
1138: return 1;
1139: }
1140:
1.76 itojun 1141: static Key *
1.229 ! jcs 1142: load_identity_file(Identity *id)
1.51 markus 1143: {
1144: Key *private;
1.229 ! jcs 1145: char prompt[300], *passphrase, *comment;
1.215 djm 1146: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1147: struct stat st;
1.16 markus 1148:
1.229 ! jcs 1149: if (stat(id->filename, &st) < 0) {
! 1150: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
! 1151: id->filename, strerror(errno));
1.52 markus 1152: return NULL;
1153: }
1.214 djm 1154: snprintf(prompt, sizeof prompt,
1.229 ! jcs 1155: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1156: for (i = 0; i <= options.number_of_password_prompts; i++) {
1157: if (i == 0)
1158: passphrase = "";
1159: else {
1.20 markus 1160: passphrase = read_passphrase(prompt, 0);
1.214 djm 1161: if (*passphrase == '\0') {
1.20 markus 1162: debug2("no passphrase given, try next key");
1.214 djm 1163: free(passphrase);
1164: break;
1165: }
1166: }
1.229 ! jcs 1167: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
! 1168: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1169: case 0:
1170: break;
1171: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1172: if (options.batch_mode) {
1173: quit = 1;
1174: break;
1175: }
1.215 djm 1176: if (i != 0)
1177: debug2("bad passphrase given, try again...");
1.214 djm 1178: break;
1179: case SSH_ERR_SYSTEM_ERROR:
1180: if (errno == ENOENT) {
1181: debug2("Load key \"%s\": %s",
1.229 ! jcs 1182: id->filename, ssh_err(r));
1.51 markus 1183: quit = 1;
1.214 djm 1184: break;
1.20 markus 1185: }
1.214 djm 1186: /* FALLTHROUGH */
1187: default:
1.229 ! jcs 1188: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1189: quit = 1;
1190: break;
1191: }
1.229 ! jcs 1192: if (!quit && private != NULL && !id->agent_fd &&
! 1193: !(id->key && id->isprivate))
! 1194: maybe_add_key_to_agent(id->filename, private, comment,
! 1195: passphrase);
1.214 djm 1196: if (i > 0) {
1.204 djm 1197: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1198: free(passphrase);
1.16 markus 1199: }
1.229 ! jcs 1200: if (comment)
! 1201: free(comment);
1.214 djm 1202: if (private != NULL || quit)
1203: break;
1.16 markus 1204: }
1.51 markus 1205: return private;
1206: }
1207:
1.117 markus 1208: /*
1209: * try keys in the following order:
1.227 djm 1210: * 1. certificates listed in the config file
1211: * 2. other input certificates
1212: * 3. agent keys that are found in the config file
1213: * 4. other agent keys
1214: * 5. keys that are only listed in the config file
1.117 markus 1215: */
1216: static void
1217: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1218: {
1.214 djm 1219: struct identity *id, *id2, *tmp;
1220: struct idlist agent, files, *preferred;
1221: struct sshkey *key;
1222: int agent_fd, i, r, found;
1223: size_t j;
1224: struct ssh_identitylist *idlist;
1.51 markus 1225:
1.117 markus 1226: TAILQ_INIT(&agent); /* keys from the agent */
1227: TAILQ_INIT(&files); /* keys from the config file */
1228: preferred = &authctxt->keys;
1229: TAILQ_INIT(preferred); /* preferred order of keys */
1230:
1.190 djm 1231: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1232: for (i = 0; i < options.num_identity_files; i++) {
1233: key = options.identity_keys[i];
1234: if (key && key->type == KEY_RSA1)
1.180 djm 1235: continue;
1236: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1237: continue;
1238: options.identity_keys[i] = NULL;
1.150 djm 1239: id = xcalloc(1, sizeof(*id));
1.117 markus 1240: id->key = key;
1241: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1242: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1243: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1244: }
1245: /* Prefer PKCS11 keys that are explicitly listed */
1246: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1.209 djm 1247: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1248: continue;
1249: found = 0;
1250: TAILQ_FOREACH(id2, &files, next) {
1251: if (id2->key == NULL ||
1.209 djm 1252: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1253: continue;
1.214 djm 1254: if (sshkey_equal(id->key, id2->key)) {
1.190 djm 1255: TAILQ_REMOVE(&files, id, next);
1256: TAILQ_INSERT_TAIL(preferred, id, next);
1257: found = 1;
1258: break;
1259: }
1260: }
1261: /* If IdentitiesOnly set and key not found then don't use it */
1262: if (!found && options.identities_only) {
1263: TAILQ_REMOVE(&files, id, next);
1.203 tedu 1264: explicit_bzero(id, sizeof(*id));
1.190 djm 1265: free(id);
1266: }
1.227 djm 1267: }
1268: /* list of certificates specified by user */
1269: for (i = 0; i < options.num_certificate_files; i++) {
1270: key = options.certificates[i];
1271: if (!key_is_cert(key) || key->cert == NULL ||
1272: key->cert->type != SSH2_CERT_TYPE_USER)
1273: continue;
1274: id = xcalloc(1, sizeof(*id));
1275: id->key = key;
1276: id->filename = xstrdup(options.certificate_files[i]);
1277: id->userprovided = options.certificate_file_userprovided[i];
1278: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1279: }
1280: /* list of keys supported by the agent */
1.214 djm 1281: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1282: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1283: debug("%s: ssh_get_authentication_socket: %s",
1284: __func__, ssh_err(r));
1285: } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1286: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1287: debug("%s: ssh_fetch_identitylist: %s",
1288: __func__, ssh_err(r));
1289: } else {
1290: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1291: found = 0;
1292: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1293: /*
1294: * agent keys from the config file are
1295: * preferred
1296: */
1297: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1298: TAILQ_REMOVE(&files, id, next);
1299: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1300: id->agent_fd = agent_fd;
1.117 markus 1301: found = 1;
1302: break;
1303: }
1304: }
1.135 markus 1305: if (!found && !options.identities_only) {
1.150 djm 1306: id = xcalloc(1, sizeof(*id));
1.214 djm 1307: /* XXX "steals" key/comment from idlist */
1308: id->key = idlist->keys[j];
1309: id->filename = idlist->comments[j];
1310: idlist->keys[j] = NULL;
1311: idlist->comments[j] = NULL;
1312: id->agent_fd = agent_fd;
1.117 markus 1313: TAILQ_INSERT_TAIL(&agent, id, next);
1314: }
1315: }
1.214 djm 1316: ssh_free_identitylist(idlist);
1.117 markus 1317: /* append remaining agent keys */
1318: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1319: TAILQ_REMOVE(&agent, id, next);
1320: TAILQ_INSERT_TAIL(preferred, id, next);
1321: }
1.214 djm 1322: authctxt->agent_fd = agent_fd;
1.117 markus 1323: }
1324: /* append remaining keys from the config file */
1325: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1326: TAILQ_REMOVE(&files, id, next);
1327: TAILQ_INSERT_TAIL(preferred, id, next);
1328: }
1.228 djm 1329: /* finally, filter by PubkeyAcceptedKeyTypes */
1330: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1331: if (id->key != NULL &&
1332: match_pattern_list(sshkey_ssh_name(id->key),
1333: options.pubkey_key_types, 0) != 1) {
1334: debug("Skipping %s key %s - "
1335: "not in PubkeyAcceptedKeyTypes",
1336: sshkey_ssh_name(id->key), id->filename);
1337: TAILQ_REMOVE(preferred, id, next);
1338: sshkey_free(id->key);
1339: free(id->filename);
1340: memset(id, 0, sizeof(*id));
1341: continue;
1342: }
1.191 dtucker 1343: debug2("key: %s (%p),%s", id->filename, id->key,
1344: id->userprovided ? " explicit" : "");
1.117 markus 1345: }
1.17 markus 1346: }
1347:
1.117 markus 1348: static void
1349: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1350: {
1.117 markus 1351: Identity *id;
1.51 markus 1352:
1.214 djm 1353: if (authctxt->agent_fd != -1)
1354: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1355: for (id = TAILQ_FIRST(&authctxt->keys); id;
1356: id = TAILQ_FIRST(&authctxt->keys)) {
1357: TAILQ_REMOVE(&authctxt->keys, id, next);
1358: if (id->key)
1.214 djm 1359: sshkey_free(id->key);
1.197 djm 1360: free(id->filename);
1361: free(id);
1.117 markus 1362: }
1.1 markus 1363: }
1364:
1.225 markus 1365: static int
1366: try_identity(Identity *id)
1367: {
1368: if (!id->key)
1369: return (0);
1370: if (key_type_plain(id->key->type) == KEY_RSA &&
1371: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1372: debug("Skipped %s key %s for RSA/MD5 server",
1373: key_type(id->key), id->filename);
1374: return (0);
1375: }
1376: return (id->key->type != KEY_RSA1);
1377: }
1378:
1.20 markus 1379: int
1380: userauth_pubkey(Authctxt *authctxt)
1381: {
1.117 markus 1382: Identity *id;
1.20 markus 1383: int sent = 0;
1384:
1.117 markus 1385: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1386: if (id->tried++)
1387: return (0);
1.127 markus 1388: /* move key to the end of the queue */
1.117 markus 1389: TAILQ_REMOVE(&authctxt->keys, id, next);
1390: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1391: /*
1392: * send a test message if we have the public key. for
1393: * encrypted keys we cannot do this and have to load the
1394: * private key instead
1395: */
1.200 djm 1396: if (id->key != NULL) {
1.225 markus 1397: if (try_identity(id)) {
1.200 djm 1398: debug("Offering %s public key: %s",
1399: key_type(id->key), id->filename);
1400: sent = send_pubkey_test(authctxt, id);
1401: }
1402: } else {
1.117 markus 1403: debug("Trying private key: %s", id->filename);
1.229 ! jcs 1404: id->key = load_identity_file(id);
1.117 markus 1405: if (id->key != NULL) {
1.225 markus 1406: if (try_identity(id)) {
1407: id->isprivate = 1;
1.200 djm 1408: sent = sign_and_send_pubkey(
1409: authctxt, id);
1410: }
1.117 markus 1411: key_free(id->key);
1412: id->key = NULL;
1.51 markus 1413: }
1414: }
1.117 markus 1415: if (sent)
1416: return (sent);
1.28 markus 1417: }
1.117 markus 1418: return (0);
1.20 markus 1419: }
1420:
1.23 markus 1421: /*
1422: * Send userauth request message specifying keyboard-interactive method.
1423: */
1424: int
1425: userauth_kbdint(Authctxt *authctxt)
1426: {
1427: static int attempt = 0;
1428:
1429: if (attempt++ >= options.number_of_password_prompts)
1430: return 0;
1.82 markus 1431: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1432: if (attempt > 1 && !authctxt->info_req_seen) {
1433: debug3("userauth_kbdint: disable: no info_req_seen");
1434: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1435: return 0;
1436: }
1.23 markus 1437:
1438: debug2("userauth_kbdint");
1439: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1440: packet_put_cstring(authctxt->server_user);
1441: packet_put_cstring(authctxt->service);
1442: packet_put_cstring(authctxt->method->name);
1443: packet_put_cstring(""); /* lang */
1444: packet_put_cstring(options.kbd_interactive_devices ?
1445: options.kbd_interactive_devices : "");
1446: packet_send();
1447:
1448: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1449: return 1;
1450: }
1451:
1452: /*
1.46 markus 1453: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1454: */
1.218 markus 1455: int
1.92 markus 1456: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1457: {
1458: Authctxt *authctxt = ctxt;
1.46 markus 1459: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1460: u_int num_prompts, i;
1.23 markus 1461: int echo = 0;
1462:
1463: debug2("input_userauth_info_req");
1464:
1465: if (authctxt == NULL)
1466: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1467:
1468: authctxt->info_req_seen = 1;
1.23 markus 1469:
1470: name = packet_get_string(NULL);
1471: inst = packet_get_string(NULL);
1472: lang = packet_get_string(NULL);
1473: if (strlen(name) > 0)
1.116 itojun 1474: logit("%s", name);
1.23 markus 1475: if (strlen(inst) > 0)
1.116 itojun 1476: logit("%s", inst);
1.197 djm 1477: free(name);
1478: free(inst);
1479: free(lang);
1.23 markus 1480:
1481: num_prompts = packet_get_int();
1482: /*
1483: * Begin to build info response packet based on prompts requested.
1484: * We commit to providing the correct number of responses, so if
1485: * further on we run into a problem that prevents this, we have to
1486: * be sure and clean this up and send a correct error response.
1487: */
1488: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1489: packet_put_int(num_prompts);
1490:
1.73 markus 1491: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1492: for (i = 0; i < num_prompts; i++) {
1493: prompt = packet_get_string(NULL);
1494: echo = packet_get_char();
1495:
1.77 markus 1496: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1497:
1.49 markus 1498: packet_put_cstring(response);
1.204 djm 1499: explicit_bzero(response, strlen(response));
1.197 djm 1500: free(response);
1501: free(prompt);
1.23 markus 1502: }
1.90 markus 1503: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1504:
1.85 markus 1505: packet_add_padding(64);
1.23 markus 1506: packet_send();
1.218 markus 1507: return 0;
1.68 markus 1508: }
1509:
1.100 markus 1510: static int
1.223 djm 1511: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1512: const u_char *data, size_t datalen)
1.100 markus 1513: {
1.223 djm 1514: struct sshbuf *b;
1.101 markus 1515: struct stat st;
1.100 markus 1516: pid_t pid;
1.223 djm 1517: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1518: u_char rversion = 0, version = 2;
1519: void (*osigchld)(int);
1.100 markus 1520:
1.223 djm 1521: *sigp = NULL;
1522: *lenp = 0;
1.100 markus 1523:
1.101 markus 1524: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1525: error("%s: not installed: %s", __func__, strerror(errno));
1526: return -1;
1527: }
1528: if (fflush(stdout) != 0) {
1529: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1530: return -1;
1531: }
1.100 markus 1532: if (pipe(to) < 0) {
1.223 djm 1533: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1534: return -1;
1535: }
1536: if (pipe(from) < 0) {
1.223 djm 1537: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1538: return -1;
1539: }
1540: if ((pid = fork()) < 0) {
1.223 djm 1541: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1542: return -1;
1543: }
1.223 djm 1544: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1545: if (pid == 0) {
1.174 dtucker 1546: /* keep the socket on exec */
1.223 djm 1547: fcntl(sock, F_SETFD, 0);
1.155 markus 1548: permanently_drop_suid(getuid());
1.100 markus 1549: close(from[0]);
1550: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1551: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1552: close(to[1]);
1553: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1554: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1555: close(from[1]);
1556: close(to[0]);
1.223 djm 1557: /* Close everything but stdio and the socket */
1558: for (i = STDERR_FILENO + 1; i < sock; i++)
1559: close(i);
1560: closefrom(sock + 1);
1561: debug3("%s: [child] pid=%ld, exec %s",
1562: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.102 markus 1563: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.223 djm 1564: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1565: strerror(errno));
1566: }
1567: close(from[1]);
1568: close(to[0]);
1569:
1.223 djm 1570: if ((b = sshbuf_new()) == NULL)
1571: fatal("%s: sshbuf_new failed", __func__);
1572: /* send # of sock, data to be signed */
1573: if ((r = sshbuf_put_u32(b, sock) != 0) ||
1574: (r = sshbuf_put_string(b, data, datalen)) != 0)
1575: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1576: if (ssh_msg_send(to[1], version, b) == -1)
1577: fatal("%s: couldn't send request", __func__);
1578: sshbuf_reset(b);
1579: r = ssh_msg_recv(from[0], b);
1.101 markus 1580: close(from[0]);
1581: close(to[1]);
1.223 djm 1582: if (r < 0) {
1583: error("%s: no reply", __func__);
1584: goto fail;
1585: }
1.101 markus 1586:
1.223 djm 1587: errno = 0;
1588: while (waitpid(pid, &status, 0) < 0) {
1589: if (errno != EINTR) {
1590: error("%s: waitpid %ld: %s",
1591: __func__, (long)pid, strerror(errno));
1592: goto fail;
1593: }
1594: }
1595: if (!WIFEXITED(status)) {
1596: error("%s: exited abnormally", __func__);
1597: goto fail;
1598: }
1599: if (WEXITSTATUS(status) != 0) {
1600: error("%s: exited with status %d",
1601: __func__, WEXITSTATUS(status));
1602: goto fail;
1603: }
1604: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1605: error("%s: buffer error: %s", __func__, ssh_err(r));
1606: goto fail;
1607: }
1608: if (rversion != version) {
1609: error("%s: bad version", __func__);
1610: goto fail;
1611: }
1612: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1613: error("%s: buffer error: %s", __func__, ssh_err(r));
1614: fail:
1615: signal(SIGCHLD, osigchld);
1616: sshbuf_free(b);
1.100 markus 1617: return -1;
1618: }
1.223 djm 1619: signal(SIGCHLD, osigchld);
1620: sshbuf_free(b);
1.100 markus 1621:
1622: return 0;
1623: }
1624:
1.68 markus 1625: int
1626: userauth_hostbased(Authctxt *authctxt)
1627: {
1.223 djm 1628: struct ssh *ssh = active_state;
1629: struct sshkey *private = NULL;
1630: struct sshbuf *b = NULL;
1.72 markus 1631: const char *service;
1.223 djm 1632: u_char *sig = NULL, *keyblob = NULL;
1633: char *fp = NULL, *chost = NULL, *lname = NULL;
1634: size_t siglen = 0, keylen = 0;
1635: int i, r, success = 0;
1636:
1637: if (authctxt->ktypes == NULL) {
1638: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1639: authctxt->ktypes = authctxt->oktypes;
1640: }
1.213 djm 1641:
1.223 djm 1642: /*
1643: * Work through each listed type pattern in HostbasedKeyTypes,
1644: * trying each hostkey that matches the type in turn.
1645: */
1646: for (;;) {
1647: if (authctxt->active_ktype == NULL)
1648: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1649: if (authctxt->active_ktype == NULL ||
1650: *authctxt->active_ktype == '\0')
1651: break;
1652: debug3("%s: trying key type %s", __func__,
1653: authctxt->active_ktype);
1.68 markus 1654:
1.223 djm 1655: /* check for a useful key */
1656: private = NULL;
1657: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1658: if (authctxt->sensitive->keys[i] == NULL ||
1659: authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
1660: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1661: continue;
1662: if (match_pattern_list(
1663: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1664: authctxt->active_ktype, 0) != 1)
1.223 djm 1665: continue;
1.68 markus 1666: /* we take and free the key */
1.223 djm 1667: private = authctxt->sensitive->keys[i];
1668: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1669: break;
1670: }
1.223 djm 1671: /* Found one */
1672: if (private != NULL)
1673: break;
1674: /* No more keys of this type; advance */
1675: authctxt->active_ktype = NULL;
1.68 markus 1676: }
1.223 djm 1677: if (private == NULL) {
1678: free(authctxt->oktypes);
1679: authctxt->oktypes = authctxt->ktypes = NULL;
1680: authctxt->active_ktype = NULL;
1.109 markus 1681: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1682: goto out;
1.68 markus 1683: }
1.211 djm 1684:
1.223 djm 1685: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1686: SSH_FP_DEFAULT)) == NULL) {
1687: error("%s: sshkey_fingerprint failed", __func__);
1688: goto out;
1.68 markus 1689: }
1.223 djm 1690: debug("%s: trying hostkey %s %s",
1691: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1692:
1.84 markus 1693: /* figure out a name for the client host */
1.223 djm 1694: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1695: error("%s: cannot get local ipaddr/name", __func__);
1696: goto out;
1.84 markus 1697: }
1.223 djm 1698:
1699: /* XXX sshbuf_put_stringf? */
1700: xasprintf(&chost, "%s.", lname);
1701: debug2("%s: chost %s", __func__, chost);
1.84 markus 1702:
1.72 markus 1703: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1704: authctxt->service;
1.223 djm 1705:
1.68 markus 1706: /* construct data */
1.223 djm 1707: if ((b = sshbuf_new()) == NULL) {
1708: error("%s: sshbuf_new failed", __func__);
1709: goto out;
1710: }
1711: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1712: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1713: goto out;
1714: }
1715: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1716: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1717: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1718: (r = sshbuf_put_cstring(b, service)) != 0 ||
1719: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1720: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1721: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1722: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1723: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1724: error("%s: buffer error: %s", __func__, ssh_err(r));
1725: goto out;
1726: }
1727:
1.68 markus 1728: #ifdef DEBUG_PK
1.223 djm 1729: sshbuf_dump(b, stderr);
1.68 markus 1730: #endif
1.223 djm 1731: if (authctxt->sensitive->external_keysign)
1732: r = ssh_keysign(private, &sig, &siglen,
1733: sshbuf_ptr(b), sshbuf_len(b));
1734: else if ((r = sshkey_sign(private, &sig, &siglen,
1735: sshbuf_ptr(b), sshbuf_len(b), datafellows)) != 0)
1736: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1737: if (r != 0) {
1738: error("sign using hostkey %s %s failed",
1739: sshkey_ssh_name(private), fp);
1740: goto out;
1741: }
1742: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1743: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1744: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1745: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1746: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1747: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1748: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1749: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1750: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1751: (r = sshpkt_send(ssh)) != 0) {
1752: error("%s: packet error: %s", __func__, ssh_err(r));
1753: goto out;
1754: }
1755: success = 1;
1756:
1757: out:
1758: if (sig != NULL) {
1759: explicit_bzero(sig, siglen);
1760: free(sig);
1.68 markus 1761: }
1.223 djm 1762: free(keyblob);
1763: free(lname);
1764: free(fp);
1.197 djm 1765: free(chost);
1.223 djm 1766: sshkey_free(private);
1767: sshbuf_free(b);
1.68 markus 1768:
1.223 djm 1769: return success;
1.23 markus 1770: }
1.170 djm 1771:
1.20 markus 1772: /* find auth method */
1773:
1774: /*
1775: * given auth method name, if configurable options permit this method fill
1776: * in auth_ident field and return true, otherwise return false.
1777: */
1.76 itojun 1778: static int
1.20 markus 1779: authmethod_is_enabled(Authmethod *method)
1780: {
1781: if (method == NULL)
1782: return 0;
1783: /* return false if options indicate this method is disabled */
1784: if (method->enabled == NULL || *method->enabled == 0)
1785: return 0;
1786: /* return false if batch mode is enabled but method needs interactive mode */
1787: if (method->batch_flag != NULL && *method->batch_flag != 0)
1788: return 0;
1789: return 1;
1790: }
1791:
1.76 itojun 1792: static Authmethod *
1.20 markus 1793: authmethod_lookup(const char *name)
1.1 markus 1794: {
1.20 markus 1795: Authmethod *method = NULL;
1796: if (name != NULL)
1797: for (method = authmethods; method->name != NULL; method++)
1798: if (strcmp(name, method->name) == 0)
1799: return method;
1800: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1801: return NULL;
1802: }
1.1 markus 1803:
1.53 markus 1804: /* XXX internal state */
1805: static Authmethod *current = NULL;
1806: static char *supported = NULL;
1807: static char *preferred = NULL;
1.105 deraadt 1808:
1.20 markus 1809: /*
1810: * Given the authentication method list sent by the server, return the
1811: * next method we should try. If the server initially sends a nil list,
1.67 markus 1812: * use a built-in default list.
1.41 stevesk 1813: */
1.76 itojun 1814: static Authmethod *
1.20 markus 1815: authmethod_get(char *authlist)
1816: {
1.53 markus 1817: char *name = NULL;
1.97 markus 1818: u_int next;
1.41 stevesk 1819:
1.20 markus 1820: /* Use a suitable default if we're passed a nil list. */
1821: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1822: authlist = options.preferred_authentications;
1.20 markus 1823:
1.53 markus 1824: if (supported == NULL || strcmp(authlist, supported) != 0) {
1825: debug3("start over, passed a different list %s", authlist);
1.197 djm 1826: free(supported);
1.53 markus 1827: supported = xstrdup(authlist);
1828: preferred = options.preferred_authentications;
1829: debug3("preferred %s", preferred);
1830: current = NULL;
1831: } else if (current != NULL && authmethod_is_enabled(current))
1832: return current;
1.20 markus 1833:
1.53 markus 1834: for (;;) {
1835: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1836: debug("No more authentication methods to try.");
1.53 markus 1837: current = NULL;
1838: return NULL;
1839: }
1840: preferred += next;
1.23 markus 1841: debug3("authmethod_lookup %s", name);
1.53 markus 1842: debug3("remaining preferred: %s", preferred);
1843: if ((current = authmethod_lookup(name)) != NULL &&
1844: authmethod_is_enabled(current)) {
1.23 markus 1845: debug3("authmethod_is_enabled %s", name);
1.109 markus 1846: debug("Next authentication method: %s", name);
1.197 djm 1847: free(name);
1.53 markus 1848: return current;
1.23 markus 1849: }
1.198 dtucker 1850: free(name);
1.1 markus 1851: }
1.53 markus 1852: }
1.1 markus 1853:
1.79 stevesk 1854: static char *
1.53 markus 1855: authmethods_get(void)
1856: {
1857: Authmethod *method = NULL;
1.93 markus 1858: Buffer b;
1859: char *list;
1.27 provos 1860:
1.93 markus 1861: buffer_init(&b);
1.53 markus 1862: for (method = authmethods; method->name != NULL; method++) {
1863: if (authmethod_is_enabled(method)) {
1.93 markus 1864: if (buffer_len(&b) > 0)
1865: buffer_append(&b, ",", 1);
1866: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1867: }
1868: }
1.93 markus 1869: buffer_append(&b, "\0", 1);
1870: list = xstrdup(buffer_ptr(&b));
1871: buffer_free(&b);
1872: return list;
1.1 markus 1873: }
1.170 djm 1874:
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