Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.226
1.226 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.225 2015/07/10 06:21:53 markus 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 *);
1.191 dtucker 308: static Key *load_identity_file(char *, int);
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 */
1.191 dtucker 985: if ((prv = load_identity_file(id->filename, id->userprovided)) == 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;
1.32 markus 996: u_char *blob, *signature;
1.214 djm 997: u_int bloblen;
998: size_t slen;
1.120 markus 999: u_int skip = 0;
1.17 markus 1000: int ret = -1;
1.23 markus 1001: int have_sig = 1;
1.182 djm 1002: char *fp;
1.1 markus 1003:
1.222 djm 1004: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1005: SSH_FP_DEFAULT)) == NULL)
1006: return 0;
1.182 djm 1007: debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1.197 djm 1008: free(fp);
1.51 markus 1009:
1.117 markus 1010: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1011: /* we cannot handle this key */
1.30 markus 1012: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1013: return 0;
1014: }
1.1 markus 1015: /* data to be signed */
1016: buffer_init(&b);
1.26 markus 1017: if (datafellows & SSH_OLD_SESSIONID) {
1018: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1019: skip = session_id2_len;
1.26 markus 1020: } else {
1.14 markus 1021: buffer_put_string(&b, session_id2, session_id2_len);
1022: skip = buffer_len(&b);
1023: }
1.1 markus 1024: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1025: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1026: buffer_put_cstring(&b,
1.30 markus 1027: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1028: "ssh-userauth" :
1.20 markus 1029: authctxt->service);
1.30 markus 1030: if (datafellows & SSH_BUG_PKAUTH) {
1031: buffer_put_char(&b, have_sig);
1032: } else {
1033: buffer_put_cstring(&b, authctxt->method->name);
1034: buffer_put_char(&b, have_sig);
1.117 markus 1035: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1036: }
1.1 markus 1037: buffer_put_string(&b, blob, bloblen);
1038:
1039: /* generate signature */
1.117 markus 1040: ret = identity_sign(id, &signature, &slen,
1.214 djm 1041: buffer_ptr(&b), buffer_len(&b), datafellows);
1042: if (ret != 0) {
1.197 djm 1043: free(blob);
1.17 markus 1044: buffer_free(&b);
1045: return 0;
1046: }
1.28 markus 1047: #ifdef DEBUG_PK
1.1 markus 1048: buffer_dump(&b);
1049: #endif
1.30 markus 1050: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1051: buffer_clear(&b);
1052: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1053: skip = session_id2_len;
1.10 markus 1054: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1055: buffer_put_cstring(&b, authctxt->server_user);
1056: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1057: buffer_put_cstring(&b, authctxt->method->name);
1058: buffer_put_char(&b, have_sig);
1.30 markus 1059: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1060: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1061: buffer_put_string(&b, blob, bloblen);
1062: }
1.197 djm 1063: free(blob);
1.51 markus 1064:
1.1 markus 1065: /* append signature */
1066: buffer_put_string(&b, signature, slen);
1.197 djm 1067: free(signature);
1.1 markus 1068:
1069: /* skip session id and packet type */
1.14 markus 1070: if (buffer_len(&b) < skip + 1)
1.20 markus 1071: fatal("userauth_pubkey: internal error");
1.14 markus 1072: buffer_consume(&b, skip + 1);
1.1 markus 1073:
1074: /* put remaining data from buffer into packet */
1075: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1076: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1077: buffer_free(&b);
1078: packet_send();
1.17 markus 1079:
1080: return 1;
1.16 markus 1081: }
1082:
1.76 itojun 1083: static int
1.117 markus 1084: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1085: {
1.51 markus 1086: u_char *blob;
1.97 markus 1087: u_int bloblen, have_sig = 0;
1.20 markus 1088:
1.51 markus 1089: debug3("send_pubkey_test");
1.16 markus 1090:
1.117 markus 1091: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1092: /* we cannot handle this key */
1093: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1094: return 0;
1095: }
1.51 markus 1096: /* register callback for USERAUTH_PK_OK message */
1097: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1098:
1099: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1100: packet_put_cstring(authctxt->server_user);
1101: packet_put_cstring(authctxt->service);
1102: packet_put_cstring(authctxt->method->name);
1103: packet_put_char(have_sig);
1104: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1105: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1106: packet_put_string(blob, bloblen);
1.197 djm 1107: free(blob);
1.51 markus 1108: packet_send();
1109: return 1;
1110: }
1111:
1.76 itojun 1112: static Key *
1.191 dtucker 1113: load_identity_file(char *filename, int userprovided)
1.51 markus 1114: {
1115: Key *private;
1116: char prompt[300], *passphrase;
1.215 djm 1117: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1118: struct stat st;
1.16 markus 1119:
1.52 markus 1120: if (stat(filename, &st) < 0) {
1.191 dtucker 1121: (userprovided ? logit : debug3)("no such identity: %s: %s",
1122: filename, strerror(errno));
1.52 markus 1123: return NULL;
1124: }
1.214 djm 1125: snprintf(prompt, sizeof prompt,
1126: "Enter passphrase for key '%.100s': ", filename);
1127: for (i = 0; i <= options.number_of_password_prompts; i++) {
1128: if (i == 0)
1129: passphrase = "";
1130: else {
1.20 markus 1131: passphrase = read_passphrase(prompt, 0);
1.214 djm 1132: if (*passphrase == '\0') {
1.20 markus 1133: debug2("no passphrase given, try next key");
1.214 djm 1134: free(passphrase);
1135: break;
1136: }
1137: }
1138: switch ((r = sshkey_load_private_type(KEY_UNSPEC, filename,
1139: passphrase, &private, NULL, &perm_ok))) {
1140: case 0:
1141: break;
1142: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1143: if (options.batch_mode) {
1144: quit = 1;
1145: break;
1146: }
1.215 djm 1147: if (i != 0)
1148: debug2("bad passphrase given, try again...");
1.214 djm 1149: break;
1150: case SSH_ERR_SYSTEM_ERROR:
1151: if (errno == ENOENT) {
1152: debug2("Load key \"%s\": %s",
1153: filename, ssh_err(r));
1.51 markus 1154: quit = 1;
1.214 djm 1155: break;
1.20 markus 1156: }
1.214 djm 1157: /* FALLTHROUGH */
1158: default:
1159: error("Load key \"%s\": %s", filename, ssh_err(r));
1160: quit = 1;
1161: break;
1162: }
1163: if (i > 0) {
1.204 djm 1164: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1165: free(passphrase);
1.16 markus 1166: }
1.214 djm 1167: if (private != NULL || quit)
1168: break;
1.16 markus 1169: }
1.51 markus 1170: return private;
1171: }
1172:
1.117 markus 1173: /*
1174: * try keys in the following order:
1175: * 1. agent keys that are found in the config file
1176: * 2. other agent keys
1177: * 3. keys that are only listed in the config file
1178: */
1179: static void
1180: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1181: {
1.214 djm 1182: struct identity *id, *id2, *tmp;
1183: struct idlist agent, files, *preferred;
1184: struct sshkey *key;
1185: int agent_fd, i, r, found;
1186: size_t j;
1187: struct ssh_identitylist *idlist;
1.51 markus 1188:
1.117 markus 1189: TAILQ_INIT(&agent); /* keys from the agent */
1190: TAILQ_INIT(&files); /* keys from the config file */
1191: preferred = &authctxt->keys;
1192: TAILQ_INIT(preferred); /* preferred order of keys */
1193:
1.190 djm 1194: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1195: for (i = 0; i < options.num_identity_files; i++) {
1196: key = options.identity_keys[i];
1197: if (key && key->type == KEY_RSA1)
1.180 djm 1198: continue;
1199: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1200: continue;
1201: options.identity_keys[i] = NULL;
1.150 djm 1202: id = xcalloc(1, sizeof(*id));
1.117 markus 1203: id->key = key;
1204: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1205: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1206: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1207: }
1208: /* Prefer PKCS11 keys that are explicitly listed */
1209: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1.209 djm 1210: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1211: continue;
1212: found = 0;
1213: TAILQ_FOREACH(id2, &files, next) {
1214: if (id2->key == NULL ||
1.209 djm 1215: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1.190 djm 1216: continue;
1.214 djm 1217: if (sshkey_equal(id->key, id2->key)) {
1.190 djm 1218: TAILQ_REMOVE(&files, id, next);
1219: TAILQ_INSERT_TAIL(preferred, id, next);
1220: found = 1;
1221: break;
1222: }
1223: }
1224: /* If IdentitiesOnly set and key not found then don't use it */
1225: if (!found && options.identities_only) {
1226: TAILQ_REMOVE(&files, id, next);
1.203 tedu 1227: explicit_bzero(id, sizeof(*id));
1.190 djm 1228: free(id);
1229: }
1.117 markus 1230: }
1231: /* list of keys supported by the agent */
1.214 djm 1232: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1233: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1234: debug("%s: ssh_get_authentication_socket: %s",
1235: __func__, ssh_err(r));
1236: } else if ((r = ssh_fetch_identitylist(agent_fd, 2, &idlist)) != 0) {
1237: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1238: debug("%s: ssh_fetch_identitylist: %s",
1239: __func__, ssh_err(r));
1240: } else {
1241: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1242: found = 0;
1243: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1244: /*
1245: * agent keys from the config file are
1246: * preferred
1247: */
1248: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1249: TAILQ_REMOVE(&files, id, next);
1250: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1251: id->agent_fd = agent_fd;
1.117 markus 1252: found = 1;
1253: break;
1254: }
1255: }
1.135 markus 1256: if (!found && !options.identities_only) {
1.150 djm 1257: id = xcalloc(1, sizeof(*id));
1.214 djm 1258: /* XXX "steals" key/comment from idlist */
1259: id->key = idlist->keys[j];
1260: id->filename = idlist->comments[j];
1261: idlist->keys[j] = NULL;
1262: idlist->comments[j] = NULL;
1263: id->agent_fd = agent_fd;
1.117 markus 1264: TAILQ_INSERT_TAIL(&agent, id, next);
1265: }
1266: }
1.214 djm 1267: ssh_free_identitylist(idlist);
1.117 markus 1268: /* append remaining agent keys */
1269: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1270: TAILQ_REMOVE(&agent, id, next);
1271: TAILQ_INSERT_TAIL(preferred, id, next);
1272: }
1.214 djm 1273: authctxt->agent_fd = agent_fd;
1.117 markus 1274: }
1275: /* append remaining keys from the config file */
1276: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1277: TAILQ_REMOVE(&files, id, next);
1278: TAILQ_INSERT_TAIL(preferred, id, next);
1279: }
1280: TAILQ_FOREACH(id, preferred, next) {
1.191 dtucker 1281: debug2("key: %s (%p),%s", id->filename, id->key,
1282: id->userprovided ? " explicit" : "");
1.117 markus 1283: }
1.17 markus 1284: }
1285:
1.117 markus 1286: static void
1287: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1288: {
1.117 markus 1289: Identity *id;
1.51 markus 1290:
1.214 djm 1291: if (authctxt->agent_fd != -1)
1292: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1293: for (id = TAILQ_FIRST(&authctxt->keys); id;
1294: id = TAILQ_FIRST(&authctxt->keys)) {
1295: TAILQ_REMOVE(&authctxt->keys, id, next);
1296: if (id->key)
1.214 djm 1297: sshkey_free(id->key);
1.197 djm 1298: free(id->filename);
1299: free(id);
1.117 markus 1300: }
1.1 markus 1301: }
1302:
1.225 markus 1303: static int
1304: try_identity(Identity *id)
1305: {
1306: if (!id->key)
1307: return (0);
1308: if (match_pattern_list(sshkey_ssh_name(id->key),
1309: options.pubkey_key_types, 0) != 1) {
1310: debug("Skipping %s key %s for not in PubkeyAcceptedKeyTypes",
1311: sshkey_ssh_name(id->key), id->filename);
1312: return (0);
1313: }
1314: if (key_type_plain(id->key->type) == KEY_RSA &&
1315: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1316: debug("Skipped %s key %s for RSA/MD5 server",
1317: key_type(id->key), id->filename);
1318: return (0);
1319: }
1320: return (id->key->type != KEY_RSA1);
1321: }
1322:
1.20 markus 1323: int
1324: userauth_pubkey(Authctxt *authctxt)
1325: {
1.117 markus 1326: Identity *id;
1.20 markus 1327: int sent = 0;
1328:
1.117 markus 1329: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1330: if (id->tried++)
1331: return (0);
1.127 markus 1332: /* move key to the end of the queue */
1.117 markus 1333: TAILQ_REMOVE(&authctxt->keys, id, next);
1334: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1335: /*
1336: * send a test message if we have the public key. for
1337: * encrypted keys we cannot do this and have to load the
1338: * private key instead
1339: */
1.200 djm 1340: if (id->key != NULL) {
1.225 markus 1341: if (try_identity(id)) {
1.200 djm 1342: debug("Offering %s public key: %s",
1343: key_type(id->key), id->filename);
1344: sent = send_pubkey_test(authctxt, id);
1345: }
1346: } else {
1.117 markus 1347: debug("Trying private key: %s", id->filename);
1.191 dtucker 1348: id->key = load_identity_file(id->filename,
1349: id->userprovided);
1.117 markus 1350: if (id->key != NULL) {
1.225 markus 1351: if (try_identity(id)) {
1352: id->isprivate = 1;
1.200 djm 1353: sent = sign_and_send_pubkey(
1354: authctxt, id);
1355: }
1.117 markus 1356: key_free(id->key);
1357: id->key = NULL;
1.51 markus 1358: }
1359: }
1.117 markus 1360: if (sent)
1361: return (sent);
1.28 markus 1362: }
1.117 markus 1363: return (0);
1.20 markus 1364: }
1365:
1.23 markus 1366: /*
1367: * Send userauth request message specifying keyboard-interactive method.
1368: */
1369: int
1370: userauth_kbdint(Authctxt *authctxt)
1371: {
1372: static int attempt = 0;
1373:
1374: if (attempt++ >= options.number_of_password_prompts)
1375: return 0;
1.82 markus 1376: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1377: if (attempt > 1 && !authctxt->info_req_seen) {
1378: debug3("userauth_kbdint: disable: no info_req_seen");
1379: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1380: return 0;
1381: }
1.23 markus 1382:
1383: debug2("userauth_kbdint");
1384: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1385: packet_put_cstring(authctxt->server_user);
1386: packet_put_cstring(authctxt->service);
1387: packet_put_cstring(authctxt->method->name);
1388: packet_put_cstring(""); /* lang */
1389: packet_put_cstring(options.kbd_interactive_devices ?
1390: options.kbd_interactive_devices : "");
1391: packet_send();
1392:
1393: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1394: return 1;
1395: }
1396:
1397: /*
1.46 markus 1398: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1399: */
1.218 markus 1400: int
1.92 markus 1401: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1402: {
1403: Authctxt *authctxt = ctxt;
1.46 markus 1404: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1405: u_int num_prompts, i;
1.23 markus 1406: int echo = 0;
1407:
1408: debug2("input_userauth_info_req");
1409:
1410: if (authctxt == NULL)
1411: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1412:
1413: authctxt->info_req_seen = 1;
1.23 markus 1414:
1415: name = packet_get_string(NULL);
1416: inst = packet_get_string(NULL);
1417: lang = packet_get_string(NULL);
1418: if (strlen(name) > 0)
1.116 itojun 1419: logit("%s", name);
1.23 markus 1420: if (strlen(inst) > 0)
1.116 itojun 1421: logit("%s", inst);
1.197 djm 1422: free(name);
1423: free(inst);
1424: free(lang);
1.23 markus 1425:
1426: num_prompts = packet_get_int();
1427: /*
1428: * Begin to build info response packet based on prompts requested.
1429: * We commit to providing the correct number of responses, so if
1430: * further on we run into a problem that prevents this, we have to
1431: * be sure and clean this up and send a correct error response.
1432: */
1433: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1434: packet_put_int(num_prompts);
1435:
1.73 markus 1436: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1437: for (i = 0; i < num_prompts; i++) {
1438: prompt = packet_get_string(NULL);
1439: echo = packet_get_char();
1440:
1.77 markus 1441: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1442:
1.49 markus 1443: packet_put_cstring(response);
1.204 djm 1444: explicit_bzero(response, strlen(response));
1.197 djm 1445: free(response);
1446: free(prompt);
1.23 markus 1447: }
1.90 markus 1448: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1449:
1.85 markus 1450: packet_add_padding(64);
1.23 markus 1451: packet_send();
1.218 markus 1452: return 0;
1.68 markus 1453: }
1454:
1.100 markus 1455: static int
1.223 djm 1456: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1457: const u_char *data, size_t datalen)
1.100 markus 1458: {
1.223 djm 1459: struct sshbuf *b;
1.101 markus 1460: struct stat st;
1.100 markus 1461: pid_t pid;
1.223 djm 1462: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1463: u_char rversion = 0, version = 2;
1464: void (*osigchld)(int);
1.100 markus 1465:
1.223 djm 1466: *sigp = NULL;
1467: *lenp = 0;
1.100 markus 1468:
1.101 markus 1469: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1470: error("%s: not installed: %s", __func__, strerror(errno));
1471: return -1;
1472: }
1473: if (fflush(stdout) != 0) {
1474: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1475: return -1;
1476: }
1.100 markus 1477: if (pipe(to) < 0) {
1.223 djm 1478: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1479: return -1;
1480: }
1481: if (pipe(from) < 0) {
1.223 djm 1482: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1483: return -1;
1484: }
1485: if ((pid = fork()) < 0) {
1.223 djm 1486: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1487: return -1;
1488: }
1.223 djm 1489: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1490: if (pid == 0) {
1.174 dtucker 1491: /* keep the socket on exec */
1.223 djm 1492: fcntl(sock, F_SETFD, 0);
1.155 markus 1493: permanently_drop_suid(getuid());
1.100 markus 1494: close(from[0]);
1495: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1496: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1497: close(to[1]);
1498: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1499: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1500: close(from[1]);
1501: close(to[0]);
1.223 djm 1502: /* Close everything but stdio and the socket */
1503: for (i = STDERR_FILENO + 1; i < sock; i++)
1504: close(i);
1505: closefrom(sock + 1);
1506: debug3("%s: [child] pid=%ld, exec %s",
1507: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.102 markus 1508: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.223 djm 1509: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1510: strerror(errno));
1511: }
1512: close(from[1]);
1513: close(to[0]);
1514:
1.223 djm 1515: if ((b = sshbuf_new()) == NULL)
1516: fatal("%s: sshbuf_new failed", __func__);
1517: /* send # of sock, data to be signed */
1518: if ((r = sshbuf_put_u32(b, sock) != 0) ||
1519: (r = sshbuf_put_string(b, data, datalen)) != 0)
1520: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1521: if (ssh_msg_send(to[1], version, b) == -1)
1522: fatal("%s: couldn't send request", __func__);
1523: sshbuf_reset(b);
1524: r = ssh_msg_recv(from[0], b);
1.101 markus 1525: close(from[0]);
1526: close(to[1]);
1.223 djm 1527: if (r < 0) {
1528: error("%s: no reply", __func__);
1529: goto fail;
1530: }
1.101 markus 1531:
1.223 djm 1532: errno = 0;
1533: while (waitpid(pid, &status, 0) < 0) {
1534: if (errno != EINTR) {
1535: error("%s: waitpid %ld: %s",
1536: __func__, (long)pid, strerror(errno));
1537: goto fail;
1538: }
1539: }
1540: if (!WIFEXITED(status)) {
1541: error("%s: exited abnormally", __func__);
1542: goto fail;
1543: }
1544: if (WEXITSTATUS(status) != 0) {
1545: error("%s: exited with status %d",
1546: __func__, WEXITSTATUS(status));
1547: goto fail;
1548: }
1549: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1550: error("%s: buffer error: %s", __func__, ssh_err(r));
1551: goto fail;
1552: }
1553: if (rversion != version) {
1554: error("%s: bad version", __func__);
1555: goto fail;
1556: }
1557: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1558: error("%s: buffer error: %s", __func__, ssh_err(r));
1559: fail:
1560: signal(SIGCHLD, osigchld);
1561: sshbuf_free(b);
1.100 markus 1562: return -1;
1563: }
1.223 djm 1564: signal(SIGCHLD, osigchld);
1565: sshbuf_free(b);
1.100 markus 1566:
1567: return 0;
1568: }
1569:
1.68 markus 1570: int
1571: userauth_hostbased(Authctxt *authctxt)
1572: {
1.223 djm 1573: struct ssh *ssh = active_state;
1574: struct sshkey *private = NULL;
1575: struct sshbuf *b = NULL;
1.72 markus 1576: const char *service;
1.223 djm 1577: u_char *sig = NULL, *keyblob = NULL;
1578: char *fp = NULL, *chost = NULL, *lname = NULL;
1579: size_t siglen = 0, keylen = 0;
1580: int i, r, success = 0;
1581:
1582: if (authctxt->ktypes == NULL) {
1583: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1584: authctxt->ktypes = authctxt->oktypes;
1585: }
1.213 djm 1586:
1.223 djm 1587: /*
1588: * Work through each listed type pattern in HostbasedKeyTypes,
1589: * trying each hostkey that matches the type in turn.
1590: */
1591: for (;;) {
1592: if (authctxt->active_ktype == NULL)
1593: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1594: if (authctxt->active_ktype == NULL ||
1595: *authctxt->active_ktype == '\0')
1596: break;
1597: debug3("%s: trying key type %s", __func__,
1598: authctxt->active_ktype);
1.68 markus 1599:
1.223 djm 1600: /* check for a useful key */
1601: private = NULL;
1602: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1603: if (authctxt->sensitive->keys[i] == NULL ||
1604: authctxt->sensitive->keys[i]->type == KEY_RSA1 ||
1605: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1606: continue;
1607: if (match_pattern_list(
1608: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1609: authctxt->active_ktype, 0) != 1)
1.223 djm 1610: continue;
1.68 markus 1611: /* we take and free the key */
1.223 djm 1612: private = authctxt->sensitive->keys[i];
1613: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1614: break;
1615: }
1.223 djm 1616: /* Found one */
1617: if (private != NULL)
1618: break;
1619: /* No more keys of this type; advance */
1620: authctxt->active_ktype = NULL;
1.68 markus 1621: }
1.223 djm 1622: if (private == NULL) {
1623: free(authctxt->oktypes);
1624: authctxt->oktypes = authctxt->ktypes = NULL;
1625: authctxt->active_ktype = NULL;
1.109 markus 1626: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1627: goto out;
1.68 markus 1628: }
1.211 djm 1629:
1.223 djm 1630: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1631: SSH_FP_DEFAULT)) == NULL) {
1632: error("%s: sshkey_fingerprint failed", __func__);
1633: goto out;
1.68 markus 1634: }
1.223 djm 1635: debug("%s: trying hostkey %s %s",
1636: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1637:
1.84 markus 1638: /* figure out a name for the client host */
1.223 djm 1639: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1640: error("%s: cannot get local ipaddr/name", __func__);
1641: goto out;
1.84 markus 1642: }
1.223 djm 1643:
1644: /* XXX sshbuf_put_stringf? */
1645: xasprintf(&chost, "%s.", lname);
1646: debug2("%s: chost %s", __func__, chost);
1.84 markus 1647:
1.72 markus 1648: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1649: authctxt->service;
1.223 djm 1650:
1.68 markus 1651: /* construct data */
1.223 djm 1652: if ((b = sshbuf_new()) == NULL) {
1653: error("%s: sshbuf_new failed", __func__);
1654: goto out;
1655: }
1656: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1657: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1658: goto out;
1659: }
1660: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1661: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1662: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1663: (r = sshbuf_put_cstring(b, service)) != 0 ||
1664: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1665: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1666: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1667: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1668: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1669: error("%s: buffer error: %s", __func__, ssh_err(r));
1670: goto out;
1671: }
1672:
1.68 markus 1673: #ifdef DEBUG_PK
1.223 djm 1674: sshbuf_dump(b, stderr);
1.68 markus 1675: #endif
1.223 djm 1676: if (authctxt->sensitive->external_keysign)
1677: r = ssh_keysign(private, &sig, &siglen,
1678: sshbuf_ptr(b), sshbuf_len(b));
1679: else if ((r = sshkey_sign(private, &sig, &siglen,
1680: sshbuf_ptr(b), sshbuf_len(b), datafellows)) != 0)
1681: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1682: if (r != 0) {
1683: error("sign using hostkey %s %s failed",
1684: sshkey_ssh_name(private), fp);
1685: goto out;
1686: }
1687: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1688: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1689: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1690: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1691: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1692: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1693: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1694: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1695: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1696: (r = sshpkt_send(ssh)) != 0) {
1697: error("%s: packet error: %s", __func__, ssh_err(r));
1698: goto out;
1699: }
1700: success = 1;
1701:
1702: out:
1703: if (sig != NULL) {
1704: explicit_bzero(sig, siglen);
1705: free(sig);
1.68 markus 1706: }
1.223 djm 1707: free(keyblob);
1708: free(lname);
1709: free(fp);
1.197 djm 1710: free(chost);
1.223 djm 1711: sshkey_free(private);
1712: sshbuf_free(b);
1.68 markus 1713:
1.223 djm 1714: return success;
1.23 markus 1715: }
1.170 djm 1716:
1.20 markus 1717: /* find auth method */
1718:
1719: /*
1720: * given auth method name, if configurable options permit this method fill
1721: * in auth_ident field and return true, otherwise return false.
1722: */
1.76 itojun 1723: static int
1.20 markus 1724: authmethod_is_enabled(Authmethod *method)
1725: {
1726: if (method == NULL)
1727: return 0;
1728: /* return false if options indicate this method is disabled */
1729: if (method->enabled == NULL || *method->enabled == 0)
1730: return 0;
1731: /* return false if batch mode is enabled but method needs interactive mode */
1732: if (method->batch_flag != NULL && *method->batch_flag != 0)
1733: return 0;
1734: return 1;
1735: }
1736:
1.76 itojun 1737: static Authmethod *
1.20 markus 1738: authmethod_lookup(const char *name)
1.1 markus 1739: {
1.20 markus 1740: Authmethod *method = NULL;
1741: if (name != NULL)
1742: for (method = authmethods; method->name != NULL; method++)
1743: if (strcmp(name, method->name) == 0)
1744: return method;
1745: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1746: return NULL;
1747: }
1.1 markus 1748:
1.53 markus 1749: /* XXX internal state */
1750: static Authmethod *current = NULL;
1751: static char *supported = NULL;
1752: static char *preferred = NULL;
1.105 deraadt 1753:
1.20 markus 1754: /*
1755: * Given the authentication method list sent by the server, return the
1756: * next method we should try. If the server initially sends a nil list,
1.67 markus 1757: * use a built-in default list.
1.41 stevesk 1758: */
1.76 itojun 1759: static Authmethod *
1.20 markus 1760: authmethod_get(char *authlist)
1761: {
1.53 markus 1762: char *name = NULL;
1.97 markus 1763: u_int next;
1.41 stevesk 1764:
1.20 markus 1765: /* Use a suitable default if we're passed a nil list. */
1766: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1767: authlist = options.preferred_authentications;
1.20 markus 1768:
1.53 markus 1769: if (supported == NULL || strcmp(authlist, supported) != 0) {
1770: debug3("start over, passed a different list %s", authlist);
1.197 djm 1771: free(supported);
1.53 markus 1772: supported = xstrdup(authlist);
1773: preferred = options.preferred_authentications;
1774: debug3("preferred %s", preferred);
1775: current = NULL;
1776: } else if (current != NULL && authmethod_is_enabled(current))
1777: return current;
1.20 markus 1778:
1.53 markus 1779: for (;;) {
1780: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1781: debug("No more authentication methods to try.");
1.53 markus 1782: current = NULL;
1783: return NULL;
1784: }
1785: preferred += next;
1.23 markus 1786: debug3("authmethod_lookup %s", name);
1.53 markus 1787: debug3("remaining preferred: %s", preferred);
1788: if ((current = authmethod_lookup(name)) != NULL &&
1789: authmethod_is_enabled(current)) {
1.23 markus 1790: debug3("authmethod_is_enabled %s", name);
1.109 markus 1791: debug("Next authentication method: %s", name);
1.197 djm 1792: free(name);
1.53 markus 1793: return current;
1.23 markus 1794: }
1.198 dtucker 1795: free(name);
1.1 markus 1796: }
1.53 markus 1797: }
1.1 markus 1798:
1.79 stevesk 1799: static char *
1.53 markus 1800: authmethods_get(void)
1801: {
1802: Authmethod *method = NULL;
1.93 markus 1803: Buffer b;
1804: char *list;
1.27 provos 1805:
1.93 markus 1806: buffer_init(&b);
1.53 markus 1807: for (method = authmethods; method->name != NULL; method++) {
1808: if (authmethod_is_enabled(method)) {
1.93 markus 1809: if (buffer_len(&b) > 0)
1810: buffer_append(&b, ",", 1);
1811: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1812: }
1813: }
1.93 markus 1814: buffer_append(&b, "\0", 1);
1815: list = xstrdup(buffer_ptr(&b));
1816: buffer_free(&b);
1817: return list;
1.1 markus 1818: }
1.170 djm 1819: