Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.204
1.204 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.203 2014/01/31 16:39:19 tedu 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"
58: #include "readconf.h"
1.137 djm 59: #include "misc.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"
1.22 provos 67:
1.121 markus 68: #ifdef GSSAPI
69: #include "ssh-gss.h"
70: #endif
71:
1.1 markus 72: /* import */
73: extern char *client_version_string;
74: extern char *server_version_string;
75: extern Options options;
76:
77: /*
78: * SSH2 key exchange
79: */
80:
1.32 markus 81: u_char *session_id2 = NULL;
1.120 markus 82: u_int session_id2_len = 0;
1.1 markus 83:
1.61 markus 84: char *xxx_host;
85: struct sockaddr *xxx_hostaddr;
86:
1.63 markus 87: Kex *xxx_kex = NULL;
88:
1.76 itojun 89: static int
1.75 markus 90: verify_host_key_callback(Key *hostkey)
1.61 markus 91: {
1.75 markus 92: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 93: fatal("Host key verification failed.");
1.61 markus 94: return 0;
95: }
96:
1.186 djm 97: static char *
98: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
99: {
100: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
101: size_t maxlen;
102: struct hostkeys *hostkeys;
103: int ktype;
1.188 djm 104: u_int i;
1.186 djm 105:
106: /* Find all hostkeys for this hostname */
107: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
108: hostkeys = init_hostkeys();
1.188 djm 109: for (i = 0; i < options.num_user_hostfiles; i++)
110: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
111: for (i = 0; i < options.num_system_hostfiles; i++)
112: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 113:
114: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
115: maxlen = strlen(avail) + 1;
116: first = xmalloc(maxlen);
117: last = xmalloc(maxlen);
118: *first = *last = '\0';
119:
120: #define ALG_APPEND(to, from) \
121: do { \
122: if (*to != '\0') \
123: strlcat(to, ",", maxlen); \
124: strlcat(to, from, maxlen); \
125: } while (0)
126:
127: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
128: if ((ktype = key_type_from_name(alg)) == KEY_UNSPEC)
129: fatal("%s: unknown alg %s", __func__, alg);
130: if (lookup_key_in_hostkeys_by_type(hostkeys,
131: key_type_plain(ktype), NULL))
132: ALG_APPEND(first, alg);
133: else
134: ALG_APPEND(last, alg);
135: }
136: #undef ALG_APPEND
137: xasprintf(&ret, "%s%s%s", first, *first == '\0' ? "" : ",", last);
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: {
153: Kex *kex;
1.61 markus 154:
155: xxx_host = host;
156: xxx_hostaddr = hostaddr;
1.22 provos 157:
1.29 markus 158: if (options.ciphers == (char *)-1) {
1.116 itojun 159: logit("No valid ciphers for protocol version 2 given, using defaults.");
1.29 markus 160: options.ciphers = NULL;
1.24 markus 161: }
1.22 provos 162: if (options.ciphers != NULL) {
163: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
164: myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
165: }
1.60 stevesk 166: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
167: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
168: myproposal[PROPOSAL_ENC_ALGS_STOC] =
169: compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1.22 provos 170: if (options.compression) {
1.47 markus 171: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 172: myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none";
1.22 provos 173: } else {
1.47 markus 174: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.141 markus 175: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib";
1.47 markus 176: }
177: if (options.macs != NULL) {
178: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
179: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.22 provos 180: }
1.70 markus 181: if (options.hostkeyalgorithms != NULL)
1.88 deraadt 182: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 183: compat_pkalg_proposal(options.hostkeyalgorithms);
1.186 djm 184: else {
185: /* Prefer algorithms that we already have keys for */
186: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 187: compat_pkalg_proposal(
188: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 189: }
1.185 djm 190: if (options.kex_algorithms != NULL)
191: myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
1.115 markus 192:
1.196 dtucker 193: if (options.rekey_limit || options.rekey_interval)
194: packet_set_rekey_limits((u_int32_t)options.rekey_limit,
195: (time_t)options.rekey_interval);
1.22 provos 196:
1.65 markus 197: /* start key exchange */
1.64 markus 198: kex = kex_setup(myproposal);
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;
1.199 markus 204: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 205: kex->client_version_string=client_version_string;
206: kex->server_version_string=server_version_string;
1.75 markus 207: kex->verify_host_key=&verify_host_key_callback;
1.63 markus 208:
209: xxx_kex = kex;
1.22 provos 210:
1.66 markus 211: dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1.173 andreas 212:
213: if (options.use_roaming && !kex->roaming) {
214: debug("Roaming not allowed by server");
215: options.use_roaming = 0;
216: }
1.62 markus 217:
218: session_id2 = kex->session_id;
219: session_id2_len = kex->session_id_len;
1.22 provos 220:
221: #ifdef DEBUG_KEXDH
222: /* send 1st encrypted/maced/compressed message */
223: packet_start(SSH2_MSG_IGNORE);
224: packet_put_cstring("markus");
225: packet_send();
226: packet_write_wait();
227: #endif
1.1 markus 228: }
1.11 markus 229:
1.1 markus 230: /*
231: * Authenticate user
232: */
1.20 markus 233:
234: typedef struct Authctxt Authctxt;
235: typedef struct Authmethod Authmethod;
1.117 markus 236: typedef struct identity Identity;
237: typedef struct idlist Idlist;
1.20 markus 238:
1.117 markus 239: struct identity {
240: TAILQ_ENTRY(identity) next;
241: AuthenticationConnection *ac; /* set if agent supports key */
242: Key *key; /* public/private key */
243: char *filename; /* comment for agent-only keys */
244: int tried;
245: int isprivate; /* key points to the private key */
1.191 dtucker 246: int userprovided;
1.117 markus 247: };
248: TAILQ_HEAD(idlist, identity);
1.20 markus 249:
250: struct Authctxt {
251: const char *server_user;
1.68 markus 252: const char *local_user;
1.20 markus 253: const char *host;
254: const char *service;
1.23 markus 255: Authmethod *method;
1.183 djm 256: sig_atomic_t success;
1.51 markus 257: char *authlist;
1.68 markus 258: /* pubkey */
1.117 markus 259: Idlist keys;
1.68 markus 260: AuthenticationConnection *agent;
261: /* hostbased */
1.100 markus 262: Sensitive *sensitive;
1.82 markus 263: /* kbd-interactive */
264: int info_req_seen;
1.121 markus 265: /* generic */
266: void *methoddata;
1.20 markus 267: };
268: struct Authmethod {
269: char *name; /* string to compare against server's list */
270: int (*userauth)(Authctxt *authctxt);
1.170 djm 271: void (*cleanup)(Authctxt *authctxt);
1.20 markus 272: int *enabled; /* flag in option struct that enables method */
273: int *batch_flag; /* flag in option struct that disables method */
274: };
275:
1.92 markus 276: void input_userauth_success(int, u_int32_t, void *);
1.172 djm 277: void input_userauth_success_unexpected(int, u_int32_t, void *);
1.92 markus 278: void input_userauth_failure(int, u_int32_t, void *);
279: void input_userauth_banner(int, u_int32_t, void *);
280: void input_userauth_error(int, u_int32_t, void *);
281: void input_userauth_info_req(int, u_int32_t, void *);
282: void input_userauth_pk_ok(int, u_int32_t, void *);
1.99 markus 283: void input_userauth_passwd_changereq(int, u_int32_t, void *);
1.86 itojun 284:
285: int userauth_none(Authctxt *);
286: int userauth_pubkey(Authctxt *);
287: int userauth_passwd(Authctxt *);
288: int userauth_kbdint(Authctxt *);
289: int userauth_hostbased(Authctxt *);
1.20 markus 290:
1.121 markus 291: #ifdef GSSAPI
292: int userauth_gssapi(Authctxt *authctxt);
293: void input_gssapi_response(int type, u_int32_t, void *);
294: void input_gssapi_token(int type, u_int32_t, void *);
295: void input_gssapi_hash(int type, u_int32_t, void *);
296: void input_gssapi_error(int, u_int32_t, void *);
297: void input_gssapi_errtok(int, u_int32_t, void *);
298: #endif
299:
1.86 itojun 300: void userauth(Authctxt *, char *);
1.51 markus 301:
1.117 markus 302: static int sign_and_send_pubkey(Authctxt *, Identity *);
303: static void pubkey_prepare(Authctxt *);
304: static void pubkey_cleanup(Authctxt *);
1.191 dtucker 305: static Key *load_identity_file(char *, int);
1.76 itojun 306:
307: static Authmethod *authmethod_get(char *authlist);
308: static Authmethod *authmethod_lookup(const char *name);
309: static char *authmethods_get(void);
1.20 markus 310:
311: Authmethod authmethods[] = {
1.121 markus 312: #ifdef GSSAPI
1.132 markus 313: {"gssapi-with-mic",
1.121 markus 314: userauth_gssapi,
1.170 djm 315: NULL,
1.121 markus 316: &options.gss_authentication,
317: NULL},
318: #endif
1.81 markus 319: {"hostbased",
320: userauth_hostbased,
1.170 djm 321: NULL,
1.81 markus 322: &options.hostbased_authentication,
323: NULL},
1.20 markus 324: {"publickey",
325: userauth_pubkey,
1.170 djm 326: NULL,
1.28 markus 327: &options.pubkey_authentication,
1.20 markus 328: NULL},
1.81 markus 329: {"keyboard-interactive",
330: userauth_kbdint,
1.170 djm 331: NULL,
1.81 markus 332: &options.kbd_interactive_authentication,
333: &options.batch_mode},
1.20 markus 334: {"password",
335: userauth_passwd,
1.170 djm 336: NULL,
1.20 markus 337: &options.password_authentication,
1.23 markus 338: &options.batch_mode},
339: {"none",
340: userauth_none,
341: NULL,
1.170 djm 342: NULL,
1.23 markus 343: NULL},
1.170 djm 344: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 345: };
346:
347: void
1.68 markus 348: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 349: Sensitive *sensitive)
1.20 markus 350: {
351: Authctxt authctxt;
352: int type;
1.39 markus 353:
1.73 markus 354: if (options.challenge_response_authentication)
1.39 markus 355: options.kbd_interactive_authentication = 1;
1.20 markus 356:
357: packet_start(SSH2_MSG_SERVICE_REQUEST);
358: packet_put_cstring("ssh-userauth");
359: packet_send();
1.108 markus 360: debug("SSH2_MSG_SERVICE_REQUEST sent");
1.20 markus 361: packet_write_wait();
1.91 markus 362: type = packet_read();
1.108 markus 363: if (type != SSH2_MSG_SERVICE_ACCEPT)
364: fatal("Server denied authentication request: %d", type);
1.20 markus 365: if (packet_remaining() > 0) {
1.91 markus 366: char *reply = packet_get_string(NULL);
1.108 markus 367: debug2("service_accept: %s", reply);
1.197 djm 368: free(reply);
1.20 markus 369: } else {
1.109 markus 370: debug2("buggy server: service_accept w/o service");
1.20 markus 371: }
1.90 markus 372: packet_check_eom();
1.108 markus 373: debug("SSH2_MSG_SERVICE_ACCEPT received");
1.20 markus 374:
1.53 markus 375: if (options.preferred_authentications == NULL)
376: options.preferred_authentications = authmethods_get();
377:
1.20 markus 378: /* setup authentication context */
1.82 markus 379: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 380: pubkey_prepare(&authctxt);
1.20 markus 381: authctxt.server_user = server_user;
1.68 markus 382: authctxt.local_user = local_user;
1.20 markus 383: authctxt.host = host;
384: authctxt.service = "ssh-connection"; /* service name */
385: authctxt.success = 0;
1.23 markus 386: authctxt.method = authmethod_lookup("none");
1.51 markus 387: authctxt.authlist = NULL;
1.121 markus 388: authctxt.methoddata = NULL;
1.100 markus 389: authctxt.sensitive = sensitive;
1.82 markus 390: authctxt.info_req_seen = 0;
1.23 markus 391: if (authctxt.method == NULL)
392: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 393:
394: /* initial userauth request */
1.23 markus 395: userauth_none(&authctxt);
1.20 markus 396:
1.65 markus 397: dispatch_init(&input_userauth_error);
1.20 markus 398: dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
399: dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
1.35 markus 400: dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
1.20 markus 401: dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */
402:
1.117 markus 403: pubkey_cleanup(&authctxt);
1.119 markus 404: dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
405:
1.109 markus 406: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 407: }
1.119 markus 408:
1.20 markus 409: void
1.51 markus 410: userauth(Authctxt *authctxt, char *authlist)
411: {
1.170 djm 412: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
413: authctxt->method->cleanup(authctxt);
414:
1.197 djm 415: free(authctxt->methoddata);
416: authctxt->methoddata = NULL;
1.51 markus 417: if (authlist == NULL) {
418: authlist = authctxt->authlist;
419: } else {
1.197 djm 420: free(authctxt->authlist);
1.51 markus 421: authctxt->authlist = authlist;
422: }
423: for (;;) {
424: Authmethod *method = authmethod_get(authlist);
425: if (method == NULL)
426: fatal("Permission denied (%s).", authlist);
427: authctxt->method = method;
1.119 markus 428:
429: /* reset the per method handler */
430: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
431: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
432:
433: /* and try new method */
1.51 markus 434: if (method->userauth(authctxt) != 0) {
435: debug2("we sent a %s packet, wait for reply", method->name);
436: break;
437: } else {
438: debug2("we did not send a packet, disable method");
439: method->enabled = NULL;
440: }
441: }
442: }
1.105 deraadt 443:
1.169 djm 444: /* ARGSUSED */
1.51 markus 445: void
1.92 markus 446: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 447: {
1.35 markus 448: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 449: "type %d", type);
1.35 markus 450: }
1.105 deraadt 451:
1.169 djm 452: /* ARGSUSED */
1.35 markus 453: void
1.92 markus 454: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 455: {
1.166 djm 456: char *msg, *raw, *lang;
457: u_int len;
1.126 deraadt 458:
1.35 markus 459: debug3("input_userauth_banner");
1.166 djm 460: raw = packet_get_string(&len);
1.35 markus 461: lang = packet_get_string(NULL);
1.167 markus 462: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO) {
1.166 djm 463: if (len > 65536)
464: len = 65536;
1.168 deraadt 465: msg = xmalloc(len * 4 + 1); /* max expansion from strnvis() */
1.177 dtucker 466: strnvis(msg, raw, len * 4 + 1, VIS_SAFE|VIS_OCTAL|VIS_NOSLASH);
1.125 dtucker 467: fprintf(stderr, "%s", msg);
1.197 djm 468: free(msg);
1.166 djm 469: }
1.197 djm 470: free(raw);
471: free(lang);
1.20 markus 472: }
1.105 deraadt 473:
1.169 djm 474: /* ARGSUSED */
1.20 markus 475: void
1.92 markus 476: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 477: {
478: Authctxt *authctxt = ctxt;
1.172 djm 479:
1.20 markus 480: if (authctxt == NULL)
481: fatal("input_userauth_success: no authentication context");
1.197 djm 482: free(authctxt->authlist);
483: authctxt->authlist = NULL;
1.172 djm 484: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
485: authctxt->method->cleanup(authctxt);
1.197 djm 486: free(authctxt->methoddata);
487: authctxt->methoddata = NULL;
1.20 markus 488: authctxt->success = 1; /* break out */
489: }
1.105 deraadt 490:
1.172 djm 491: void
492: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
493: {
494: Authctxt *authctxt = ctxt;
495:
496: if (authctxt == NULL)
497: fatal("%s: no authentication context", __func__);
498:
499: fatal("Unexpected authentication success during %s.",
500: authctxt->method->name);
501: }
502:
1.169 djm 503: /* ARGSUSED */
1.20 markus 504: void
1.92 markus 505: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 506: {
507: Authctxt *authctxt = ctxt;
508: char *authlist = NULL;
509: int partial;
510:
511: if (authctxt == NULL)
512: fatal("input_userauth_failure: no authentication context");
513:
1.23 markus 514: authlist = packet_get_string(NULL);
1.20 markus 515: partial = packet_get_char();
1.90 markus 516: packet_check_eom();
1.20 markus 517:
1.193 markus 518: if (partial != 0) {
1.116 itojun 519: logit("Authenticated with partial success.");
1.193 markus 520: /* reset state */
521: pubkey_cleanup(authctxt);
522: pubkey_prepare(authctxt);
523: }
1.109 markus 524: debug("Authentications that can continue: %s", authlist);
1.20 markus 525:
1.51 markus 526: userauth(authctxt, authlist);
527: }
1.169 djm 528:
529: /* ARGSUSED */
1.51 markus 530: void
1.92 markus 531: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 532: {
533: Authctxt *authctxt = ctxt;
534: Key *key = NULL;
1.117 markus 535: Identity *id = NULL;
1.51 markus 536: Buffer b;
1.96 markus 537: int pktype, sent = 0;
538: u_int alen, blen;
539: char *pkalg, *fp;
540: u_char *pkblob;
1.51 markus 541:
542: if (authctxt == NULL)
543: fatal("input_userauth_pk_ok: no authentication context");
544: if (datafellows & SSH_BUG_PKOK) {
545: /* this is similar to SSH_BUG_PKAUTH */
546: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
547: pkblob = packet_get_string(&blen);
548: buffer_init(&b);
549: buffer_append(&b, pkblob, blen);
550: pkalg = buffer_get_string(&b, &alen);
551: buffer_free(&b);
552: } else {
553: pkalg = packet_get_string(&alen);
554: pkblob = packet_get_string(&blen);
555: }
1.90 markus 556: packet_check_eom();
1.51 markus 557:
1.117 markus 558: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 559:
1.117 markus 560: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
561: debug("unknown pkalg %s", pkalg);
562: goto done;
563: }
564: if ((key = key_from_blob(pkblob, blen)) == NULL) {
565: debug("no key from blob. pkalg %s", pkalg);
566: goto done;
567: }
568: if (key->type != pktype) {
569: error("input_userauth_pk_ok: type mismatch "
570: "for decoded key (received %d, expected %d)",
571: key->type, pktype);
572: goto done;
573: }
574: fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
575: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 576: free(fp);
1.117 markus 577:
1.127 markus 578: /*
579: * search keys in the reverse order, because last candidate has been
580: * moved to the end of the queue. this also avoids confusion by
581: * duplicate keys
582: */
1.136 henning 583: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 584: if (key_equal(key, id->key)) {
585: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 586: break;
587: }
1.117 markus 588: }
589: done:
1.51 markus 590: if (key != NULL)
591: key_free(key);
1.197 djm 592: free(pkalg);
593: free(pkblob);
1.51 markus 594:
1.106 deraadt 595: /* try another method if we did not send a packet */
1.51 markus 596: if (sent == 0)
597: userauth(authctxt, NULL);
1.20 markus 598: }
1.121 markus 599:
600: #ifdef GSSAPI
1.133 djm 601: int
1.121 markus 602: userauth_gssapi(Authctxt *authctxt)
603: {
604: Gssctxt *gssctxt = NULL;
1.128 avsm 605: static gss_OID_set gss_supported = NULL;
1.139 djm 606: static u_int mech = 0;
1.121 markus 607: OM_uint32 min;
608: int ok = 0;
609:
610: /* Try one GSSAPI method at a time, rather than sending them all at
611: * once. */
612:
1.128 avsm 613: if (gss_supported == NULL)
614: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 615:
616: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 617: while (mech < gss_supported->count && !ok) {
1.121 markus 618: /* My DER encoding requires length<128 */
1.128 avsm 619: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 620: ssh_gssapi_check_mechanism(&gssctxt,
621: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 622: ok = 1; /* Mechanism works */
623: } else {
624: mech++;
625: }
626: }
627:
1.161 djm 628: if (!ok)
1.139 djm 629: return 0;
1.121 markus 630:
631: authctxt->methoddata=(void *)gssctxt;
632:
633: packet_start(SSH2_MSG_USERAUTH_REQUEST);
634: packet_put_cstring(authctxt->server_user);
635: packet_put_cstring(authctxt->service);
636: packet_put_cstring(authctxt->method->name);
637:
638: packet_put_int(1);
639:
1.129 markus 640: packet_put_int((gss_supported->elements[mech].length) + 2);
641: packet_put_char(SSH_GSS_OIDTYPE);
642: packet_put_char(gss_supported->elements[mech].length);
643: packet_put_raw(gss_supported->elements[mech].elements,
644: gss_supported->elements[mech].length);
1.121 markus 645:
646: packet_send();
647:
648: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
649: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
650: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
651: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
652:
653: mech++; /* Move along to next candidate */
654:
655: return 1;
656: }
657:
1.130 markus 658: static OM_uint32
659: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
660: {
661: Authctxt *authctxt = ctxt;
662: Gssctxt *gssctxt = authctxt->methoddata;
663: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 664: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
665: gss_buffer_desc gssbuf;
1.132 markus 666: OM_uint32 status, ms, flags;
667: Buffer b;
1.133 djm 668:
1.130 markus 669: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 670: recv_tok, &send_tok, &flags);
1.130 markus 671:
672: if (send_tok.length > 0) {
673: if (GSS_ERROR(status))
674: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
675: else
676: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 677:
1.130 markus 678: packet_put_string(send_tok.value, send_tok.length);
679: packet_send();
680: gss_release_buffer(&ms, &send_tok);
681: }
1.133 djm 682:
1.130 markus 683: if (status == GSS_S_COMPLETE) {
1.132 markus 684: /* send either complete or MIC, depending on mechanism */
685: if (!(flags & GSS_C_INTEG_FLAG)) {
686: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
687: packet_send();
688: } else {
689: ssh_gssapi_buildmic(&b, authctxt->server_user,
690: authctxt->service, "gssapi-with-mic");
691:
692: gssbuf.value = buffer_ptr(&b);
693: gssbuf.length = buffer_len(&b);
1.133 djm 694:
1.132 markus 695: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 696:
1.132 markus 697: if (!GSS_ERROR(status)) {
698: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
699: packet_put_string(mic.value, mic.length);
1.133 djm 700:
1.132 markus 701: packet_send();
702: }
1.133 djm 703:
1.132 markus 704: buffer_free(&b);
705: gss_release_buffer(&ms, &mic);
1.133 djm 706: }
1.130 markus 707: }
1.133 djm 708:
1.130 markus 709: return status;
710: }
711:
1.169 djm 712: /* ARGSUSED */
1.121 markus 713: void
714: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
715: {
716: Authctxt *authctxt = ctxt;
717: Gssctxt *gssctxt;
718: int oidlen;
719: char *oidv;
720:
721: if (authctxt == NULL)
722: fatal("input_gssapi_response: no authentication context");
723: gssctxt = authctxt->methoddata;
724:
725: /* Setup our OID */
726: oidv = packet_get_string(&oidlen);
727:
1.129 markus 728: if (oidlen <= 2 ||
729: oidv[0] != SSH_GSS_OIDTYPE ||
730: oidv[1] != oidlen - 2) {
1.197 djm 731: free(oidv);
1.129 markus 732: debug("Badly encoded mechanism OID received");
733: userauth(authctxt, NULL);
734: return;
1.121 markus 735: }
1.129 markus 736:
737: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
738: fatal("Server returned different OID than expected");
1.121 markus 739:
740: packet_check_eom();
741:
1.197 djm 742: free(oidv);
1.121 markus 743:
1.130 markus 744: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 745: /* Start again with next method on list */
746: debug("Trying to start again");
747: userauth(authctxt, NULL);
748: return;
749: }
750: }
751:
1.169 djm 752: /* ARGSUSED */
1.121 markus 753: void
754: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
755: {
756: Authctxt *authctxt = ctxt;
757: gss_buffer_desc recv_tok;
1.130 markus 758: OM_uint32 status;
1.121 markus 759: u_int slen;
760:
761: if (authctxt == NULL)
762: fatal("input_gssapi_response: no authentication context");
763:
764: recv_tok.value = packet_get_string(&slen);
765: recv_tok.length = slen; /* safe typecast */
766:
767: packet_check_eom();
768:
1.130 markus 769: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 770:
1.197 djm 771: free(recv_tok.value);
1.121 markus 772:
773: if (GSS_ERROR(status)) {
774: /* Start again with the next method in the list */
775: userauth(authctxt, NULL);
776: return;
777: }
778: }
779:
1.169 djm 780: /* ARGSUSED */
1.121 markus 781: void
782: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
783: {
784: Authctxt *authctxt = ctxt;
785: Gssctxt *gssctxt;
786: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
787: gss_buffer_desc recv_tok;
1.194 djm 788: OM_uint32 ms;
1.123 deraadt 789: u_int len;
1.121 markus 790:
791: if (authctxt == NULL)
792: fatal("input_gssapi_response: no authentication context");
793: gssctxt = authctxt->methoddata;
794:
1.123 deraadt 795: recv_tok.value = packet_get_string(&len);
796: recv_tok.length = len;
1.121 markus 797:
798: packet_check_eom();
799:
800: /* Stick it into GSSAPI and see what it says */
1.194 djm 801: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 802: &recv_tok, &send_tok, NULL);
1.121 markus 803:
1.197 djm 804: free(recv_tok.value);
1.121 markus 805: gss_release_buffer(&ms, &send_tok);
806:
807: /* Server will be returning a failed packet after this one */
808: }
809:
1.169 djm 810: /* ARGSUSED */
1.121 markus 811: void
812: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
813: {
814: char *msg;
815: char *lang;
816:
1.194 djm 817: /* maj */(void)packet_get_int();
818: /* min */(void)packet_get_int();
1.121 markus 819: msg=packet_get_string(NULL);
820: lang=packet_get_string(NULL);
821:
822: packet_check_eom();
823:
1.143 stevesk 824: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 825: free(msg);
826: free(lang);
1.121 markus 827: }
828: #endif /* GSSAPI */
1.20 markus 829:
1.1 markus 830: int
1.23 markus 831: userauth_none(Authctxt *authctxt)
832: {
833: /* initial userauth request */
834: packet_start(SSH2_MSG_USERAUTH_REQUEST);
835: packet_put_cstring(authctxt->server_user);
836: packet_put_cstring(authctxt->service);
837: packet_put_cstring(authctxt->method->name);
838: packet_send();
839: return 1;
840: }
841:
842: int
1.20 markus 843: userauth_passwd(Authctxt *authctxt)
1.1 markus 844: {
1.6 markus 845: static int attempt = 0;
1.99 markus 846: char prompt[150];
1.1 markus 847: char *password;
1.175 dtucker 848: const char *host = options.host_key_alias ? options.host_key_alias :
849: authctxt->host;
1.6 markus 850:
1.13 todd 851: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 852: return 0;
1.13 todd 853:
1.87 deraadt 854: if (attempt != 1)
1.13 todd 855: error("Permission denied, please try again.");
1.1 markus 856:
1.43 itojun 857: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 858: authctxt->server_user, host);
1.1 markus 859: password = read_passphrase(prompt, 0);
860: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 861: packet_put_cstring(authctxt->server_user);
862: packet_put_cstring(authctxt->service);
1.23 markus 863: packet_put_cstring(authctxt->method->name);
1.1 markus 864: packet_put_char(0);
1.49 markus 865: packet_put_cstring(password);
1.204 ! djm 866: explicit_bzero(password, strlen(password));
1.197 djm 867: free(password);
1.85 markus 868: packet_add_padding(64);
1.1 markus 869: packet_send();
1.99 markus 870:
1.104 deraadt 871: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 872: &input_userauth_passwd_changereq);
873:
1.1 markus 874: return 1;
875: }
1.169 djm 876:
1.99 markus 877: /*
878: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
879: */
1.169 djm 880: /* ARGSUSED */
1.99 markus 881: void
1.153 djm 882: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 883: {
884: Authctxt *authctxt = ctxt;
885: char *info, *lang, *password = NULL, *retype = NULL;
886: char prompt[150];
1.175 dtucker 887: const char *host = options.host_key_alias ? options.host_key_alias :
888: authctxt->host;
1.99 markus 889:
890: debug2("input_userauth_passwd_changereq");
891:
892: if (authctxt == NULL)
893: fatal("input_userauth_passwd_changereq: "
894: "no authentication context");
895:
896: info = packet_get_string(NULL);
897: lang = packet_get_string(NULL);
898: if (strlen(info) > 0)
1.116 itojun 899: logit("%s", info);
1.197 djm 900: free(info);
901: free(lang);
1.99 markus 902: packet_start(SSH2_MSG_USERAUTH_REQUEST);
903: packet_put_cstring(authctxt->server_user);
904: packet_put_cstring(authctxt->service);
905: packet_put_cstring(authctxt->method->name);
906: packet_put_char(1); /* additional info */
1.104 deraadt 907: snprintf(prompt, sizeof(prompt),
1.99 markus 908: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 909: authctxt->server_user, host);
1.99 markus 910: password = read_passphrase(prompt, 0);
911: packet_put_cstring(password);
1.204 ! djm 912: explicit_bzero(password, strlen(password));
1.197 djm 913: free(password);
1.99 markus 914: password = NULL;
915: while (password == NULL) {
1.104 deraadt 916: snprintf(prompt, sizeof(prompt),
1.99 markus 917: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 918: authctxt->server_user, host);
1.99 markus 919: password = read_passphrase(prompt, RP_ALLOW_EOF);
920: if (password == NULL) {
921: /* bail out */
922: return;
923: }
1.104 deraadt 924: snprintf(prompt, sizeof(prompt),
1.99 markus 925: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 926: authctxt->server_user, host);
1.99 markus 927: retype = read_passphrase(prompt, 0);
928: if (strcmp(password, retype) != 0) {
1.204 ! djm 929: explicit_bzero(password, strlen(password));
1.197 djm 930: free(password);
1.116 itojun 931: logit("Mismatch; try again, EOF to quit.");
1.99 markus 932: password = NULL;
933: }
1.204 ! djm 934: explicit_bzero(retype, strlen(retype));
1.197 djm 935: free(retype);
1.99 markus 936: }
937: packet_put_cstring(password);
1.204 ! djm 938: explicit_bzero(password, strlen(password));
1.197 djm 939: free(password);
1.99 markus 940: packet_add_padding(64);
941: packet_send();
1.104 deraadt 942:
943: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 944: &input_userauth_passwd_changereq);
1.117 markus 945: }
946:
947: static int
948: identity_sign(Identity *id, u_char **sigp, u_int *lenp,
949: u_char *data, u_int datalen)
950: {
951: Key *prv;
952: int ret;
1.99 markus 953:
1.117 markus 954: /* the agent supports this key */
955: if (id->ac)
956: return (ssh_agent_sign(id->ac, id->key, sigp, lenp,
957: data, datalen));
958: /*
959: * we have already loaded the private key or
960: * the private key is stored in external hardware
961: */
962: if (id->isprivate || (id->key->flags & KEY_FLAG_EXT))
963: return (key_sign(id->key, sigp, lenp, data, datalen));
964: /* load the private key from the file */
1.191 dtucker 965: if ((prv = load_identity_file(id->filename, id->userprovided)) == NULL)
1.117 markus 966: return (-1);
967: ret = key_sign(prv, sigp, lenp, data, datalen);
968: key_free(prv);
969: return (ret);
1.51 markus 970: }
971:
1.76 itojun 972: static int
1.117 markus 973: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 974: {
975: Buffer b;
1.32 markus 976: u_char *blob, *signature;
1.96 markus 977: u_int bloblen, slen;
1.120 markus 978: u_int skip = 0;
1.17 markus 979: int ret = -1;
1.23 markus 980: int have_sig = 1;
1.182 djm 981: char *fp;
1.1 markus 982:
1.182 djm 983: fp = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
984: debug3("sign_and_send_pubkey: %s %s", key_type(id->key), fp);
1.197 djm 985: free(fp);
1.51 markus 986:
1.117 markus 987: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 988: /* we cannot handle this key */
1.30 markus 989: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 990: return 0;
991: }
1.1 markus 992: /* data to be signed */
993: buffer_init(&b);
1.26 markus 994: if (datafellows & SSH_OLD_SESSIONID) {
995: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 996: skip = session_id2_len;
1.26 markus 997: } else {
1.14 markus 998: buffer_put_string(&b, session_id2, session_id2_len);
999: skip = buffer_len(&b);
1000: }
1.1 markus 1001: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1002: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1003: buffer_put_cstring(&b,
1.30 markus 1004: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1005: "ssh-userauth" :
1.20 markus 1006: authctxt->service);
1.30 markus 1007: if (datafellows & SSH_BUG_PKAUTH) {
1008: buffer_put_char(&b, have_sig);
1009: } else {
1010: buffer_put_cstring(&b, authctxt->method->name);
1011: buffer_put_char(&b, have_sig);
1.117 markus 1012: buffer_put_cstring(&b, key_ssh_name(id->key));
1.30 markus 1013: }
1.1 markus 1014: buffer_put_string(&b, blob, bloblen);
1015:
1016: /* generate signature */
1.117 markus 1017: ret = identity_sign(id, &signature, &slen,
1.51 markus 1018: buffer_ptr(&b), buffer_len(&b));
1.17 markus 1019: if (ret == -1) {
1.197 djm 1020: free(blob);
1.17 markus 1021: buffer_free(&b);
1022: return 0;
1023: }
1.28 markus 1024: #ifdef DEBUG_PK
1.1 markus 1025: buffer_dump(&b);
1026: #endif
1.30 markus 1027: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1028: buffer_clear(&b);
1029: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1030: skip = session_id2_len;
1.10 markus 1031: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1032: buffer_put_cstring(&b, authctxt->server_user);
1033: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1034: buffer_put_cstring(&b, authctxt->method->name);
1035: buffer_put_char(&b, have_sig);
1.30 markus 1036: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1037: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1038: buffer_put_string(&b, blob, bloblen);
1039: }
1.197 djm 1040: free(blob);
1.51 markus 1041:
1.1 markus 1042: /* append signature */
1043: buffer_put_string(&b, signature, slen);
1.197 djm 1044: free(signature);
1.1 markus 1045:
1046: /* skip session id and packet type */
1.14 markus 1047: if (buffer_len(&b) < skip + 1)
1.20 markus 1048: fatal("userauth_pubkey: internal error");
1.14 markus 1049: buffer_consume(&b, skip + 1);
1.1 markus 1050:
1051: /* put remaining data from buffer into packet */
1052: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1053: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1054: buffer_free(&b);
1055: packet_send();
1.17 markus 1056:
1057: return 1;
1.16 markus 1058: }
1059:
1.76 itojun 1060: static int
1.117 markus 1061: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1062: {
1.51 markus 1063: u_char *blob;
1.97 markus 1064: u_int bloblen, have_sig = 0;
1.20 markus 1065:
1.51 markus 1066: debug3("send_pubkey_test");
1.16 markus 1067:
1.117 markus 1068: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1069: /* we cannot handle this key */
1070: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1071: return 0;
1072: }
1.51 markus 1073: /* register callback for USERAUTH_PK_OK message */
1074: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1075:
1076: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1077: packet_put_cstring(authctxt->server_user);
1078: packet_put_cstring(authctxt->service);
1079: packet_put_cstring(authctxt->method->name);
1080: packet_put_char(have_sig);
1081: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1082: packet_put_cstring(key_ssh_name(id->key));
1.51 markus 1083: packet_put_string(blob, bloblen);
1.197 djm 1084: free(blob);
1.51 markus 1085: packet_send();
1086: return 1;
1087: }
1088:
1.76 itojun 1089: static Key *
1.191 dtucker 1090: load_identity_file(char *filename, int userprovided)
1.51 markus 1091: {
1092: Key *private;
1093: char prompt[300], *passphrase;
1.178 dtucker 1094: int perm_ok = 0, quit, i;
1.52 markus 1095: struct stat st;
1.16 markus 1096:
1.52 markus 1097: if (stat(filename, &st) < 0) {
1.191 dtucker 1098: (userprovided ? logit : debug3)("no such identity: %s: %s",
1099: filename, strerror(errno));
1.52 markus 1100: return NULL;
1101: }
1.152 dtucker 1102: private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok);
1.198 dtucker 1103: if (!perm_ok) {
1104: if (private != NULL)
1105: key_free(private);
1.152 dtucker 1106: return NULL;
1.198 dtucker 1107: }
1.56 markus 1108: if (private == NULL) {
1109: if (options.batch_mode)
1.51 markus 1110: return NULL;
1.16 markus 1111: snprintf(prompt, sizeof prompt,
1.88 deraadt 1112: "Enter passphrase for key '%.100s': ", filename);
1.20 markus 1113: for (i = 0; i < options.number_of_password_prompts; i++) {
1114: passphrase = read_passphrase(prompt, 0);
1115: if (strcmp(passphrase, "") != 0) {
1.152 dtucker 1116: private = key_load_private_type(KEY_UNSPEC,
1117: filename, passphrase, NULL, NULL);
1.51 markus 1118: quit = 0;
1.20 markus 1119: } else {
1120: debug2("no passphrase given, try next key");
1.51 markus 1121: quit = 1;
1.20 markus 1122: }
1.204 ! djm 1123: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1124: free(passphrase);
1.56 markus 1125: if (private != NULL || quit)
1.20 markus 1126: break;
1127: debug2("bad passphrase given, try again...");
1.16 markus 1128: }
1129: }
1.51 markus 1130: return private;
1131: }
1132:
1.117 markus 1133: /*
1134: * try keys in the following order:
1135: * 1. agent keys that are found in the config file
1136: * 2. other agent keys
1137: * 3. keys that are only listed in the config file
1138: */
1139: static void
1140: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1141: {
1.190 djm 1142: Identity *id, *id2, *tmp;
1.117 markus 1143: Idlist agent, files, *preferred;
1144: Key *key;
1145: AuthenticationConnection *ac;
1146: char *comment;
1147: int i, found;
1.51 markus 1148:
1.117 markus 1149: TAILQ_INIT(&agent); /* keys from the agent */
1150: TAILQ_INIT(&files); /* keys from the config file */
1151: preferred = &authctxt->keys;
1152: TAILQ_INIT(preferred); /* preferred order of keys */
1153:
1.190 djm 1154: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1155: for (i = 0; i < options.num_identity_files; i++) {
1156: key = options.identity_keys[i];
1157: if (key && key->type == KEY_RSA1)
1.180 djm 1158: continue;
1159: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1160: continue;
1161: options.identity_keys[i] = NULL;
1.150 djm 1162: id = xcalloc(1, sizeof(*id));
1.117 markus 1163: id->key = key;
1164: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1165: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1166: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1167: }
1168: /* Prefer PKCS11 keys that are explicitly listed */
1169: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1170: if (id->key == NULL || (id->key->flags & KEY_FLAG_EXT) == 0)
1171: continue;
1172: found = 0;
1173: TAILQ_FOREACH(id2, &files, next) {
1174: if (id2->key == NULL ||
1175: (id2->key->flags & KEY_FLAG_EXT) != 0)
1176: continue;
1177: if (key_equal(id->key, id2->key)) {
1178: TAILQ_REMOVE(&files, id, next);
1179: TAILQ_INSERT_TAIL(preferred, id, next);
1180: found = 1;
1181: break;
1182: }
1183: }
1184: /* If IdentitiesOnly set and key not found then don't use it */
1185: if (!found && options.identities_only) {
1186: TAILQ_REMOVE(&files, id, next);
1.203 tedu 1187: explicit_bzero(id, sizeof(*id));
1.190 djm 1188: free(id);
1189: }
1.117 markus 1190: }
1191: /* list of keys supported by the agent */
1192: if ((ac = ssh_get_authentication_connection())) {
1193: for (key = ssh_get_first_identity(ac, &comment, 2);
1194: key != NULL;
1195: key = ssh_get_next_identity(ac, &comment, 2)) {
1196: found = 0;
1197: TAILQ_FOREACH(id, &files, next) {
1.133 djm 1198: /* agent keys from the config file are preferred */
1.117 markus 1199: if (key_equal(key, id->key)) {
1200: key_free(key);
1.197 djm 1201: free(comment);
1.117 markus 1202: TAILQ_REMOVE(&files, id, next);
1203: TAILQ_INSERT_TAIL(preferred, id, next);
1204: id->ac = ac;
1205: found = 1;
1206: break;
1207: }
1208: }
1.135 markus 1209: if (!found && !options.identities_only) {
1.150 djm 1210: id = xcalloc(1, sizeof(*id));
1.117 markus 1211: id->key = key;
1212: id->filename = comment;
1213: id->ac = ac;
1214: TAILQ_INSERT_TAIL(&agent, id, next);
1215: }
1216: }
1217: /* append remaining agent keys */
1218: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1219: TAILQ_REMOVE(&agent, id, next);
1220: TAILQ_INSERT_TAIL(preferred, id, next);
1221: }
1222: authctxt->agent = ac;
1223: }
1224: /* append remaining keys from the config file */
1225: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1226: TAILQ_REMOVE(&files, id, next);
1227: TAILQ_INSERT_TAIL(preferred, id, next);
1228: }
1229: TAILQ_FOREACH(id, preferred, next) {
1.191 dtucker 1230: debug2("key: %s (%p),%s", id->filename, id->key,
1231: id->userprovided ? " explicit" : "");
1.117 markus 1232: }
1.17 markus 1233: }
1234:
1.117 markus 1235: static void
1236: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1237: {
1.117 markus 1238: Identity *id;
1.51 markus 1239:
1.117 markus 1240: if (authctxt->agent != NULL)
1241: ssh_close_authentication_connection(authctxt->agent);
1242: for (id = TAILQ_FIRST(&authctxt->keys); id;
1243: id = TAILQ_FIRST(&authctxt->keys)) {
1244: TAILQ_REMOVE(&authctxt->keys, id, next);
1245: if (id->key)
1246: key_free(id->key);
1.197 djm 1247: free(id->filename);
1248: free(id);
1.117 markus 1249: }
1.1 markus 1250: }
1251:
1.20 markus 1252: int
1253: userauth_pubkey(Authctxt *authctxt)
1254: {
1.117 markus 1255: Identity *id;
1.20 markus 1256: int sent = 0;
1257:
1.117 markus 1258: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1259: if (id->tried++)
1260: return (0);
1.127 markus 1261: /* move key to the end of the queue */
1.117 markus 1262: TAILQ_REMOVE(&authctxt->keys, id, next);
1263: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1264: /*
1265: * send a test message if we have the public key. for
1266: * encrypted keys we cannot do this and have to load the
1267: * private key instead
1268: */
1.200 djm 1269: if (id->key != NULL) {
1270: if (key_type_plain(id->key->type) == KEY_RSA &&
1271: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1272: debug("Skipped %s key %s for RSA/MD5 server",
1273: key_type(id->key), id->filename);
1274: } else if (id->key->type != KEY_RSA1) {
1275: debug("Offering %s public key: %s",
1276: key_type(id->key), id->filename);
1277: sent = send_pubkey_test(authctxt, id);
1278: }
1279: } else {
1.117 markus 1280: debug("Trying private key: %s", id->filename);
1.191 dtucker 1281: id->key = load_identity_file(id->filename,
1282: id->userprovided);
1.117 markus 1283: if (id->key != NULL) {
1284: id->isprivate = 1;
1.200 djm 1285: if (key_type_plain(id->key->type) == KEY_RSA &&
1286: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1287: debug("Skipped %s key %s for RSA/MD5 "
1288: "server", key_type(id->key),
1289: id->filename);
1290: } else {
1291: sent = sign_and_send_pubkey(
1292: authctxt, id);
1293: }
1.117 markus 1294: key_free(id->key);
1295: id->key = NULL;
1.51 markus 1296: }
1297: }
1.117 markus 1298: if (sent)
1299: return (sent);
1.28 markus 1300: }
1.117 markus 1301: return (0);
1.20 markus 1302: }
1303:
1.23 markus 1304: /*
1305: * Send userauth request message specifying keyboard-interactive method.
1306: */
1307: int
1308: userauth_kbdint(Authctxt *authctxt)
1309: {
1310: static int attempt = 0;
1311:
1312: if (attempt++ >= options.number_of_password_prompts)
1313: return 0;
1.82 markus 1314: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1315: if (attempt > 1 && !authctxt->info_req_seen) {
1316: debug3("userauth_kbdint: disable: no info_req_seen");
1317: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1318: return 0;
1319: }
1.23 markus 1320:
1321: debug2("userauth_kbdint");
1322: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1323: packet_put_cstring(authctxt->server_user);
1324: packet_put_cstring(authctxt->service);
1325: packet_put_cstring(authctxt->method->name);
1326: packet_put_cstring(""); /* lang */
1327: packet_put_cstring(options.kbd_interactive_devices ?
1328: options.kbd_interactive_devices : "");
1329: packet_send();
1330:
1331: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1332: return 1;
1333: }
1334:
1335: /*
1.46 markus 1336: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1337: */
1338: void
1.92 markus 1339: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1340: {
1341: Authctxt *authctxt = ctxt;
1.46 markus 1342: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1343: u_int num_prompts, i;
1.23 markus 1344: int echo = 0;
1345:
1346: debug2("input_userauth_info_req");
1347:
1348: if (authctxt == NULL)
1349: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1350:
1351: authctxt->info_req_seen = 1;
1.23 markus 1352:
1353: name = packet_get_string(NULL);
1354: inst = packet_get_string(NULL);
1355: lang = packet_get_string(NULL);
1356: if (strlen(name) > 0)
1.116 itojun 1357: logit("%s", name);
1.23 markus 1358: if (strlen(inst) > 0)
1.116 itojun 1359: logit("%s", inst);
1.197 djm 1360: free(name);
1361: free(inst);
1362: free(lang);
1.23 markus 1363:
1364: num_prompts = packet_get_int();
1365: /*
1366: * Begin to build info response packet based on prompts requested.
1367: * We commit to providing the correct number of responses, so if
1368: * further on we run into a problem that prevents this, we have to
1369: * be sure and clean this up and send a correct error response.
1370: */
1371: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1372: packet_put_int(num_prompts);
1373:
1.73 markus 1374: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1375: for (i = 0; i < num_prompts; i++) {
1376: prompt = packet_get_string(NULL);
1377: echo = packet_get_char();
1378:
1.77 markus 1379: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1380:
1.49 markus 1381: packet_put_cstring(response);
1.204 ! djm 1382: explicit_bzero(response, strlen(response));
1.197 djm 1383: free(response);
1384: free(prompt);
1.23 markus 1385: }
1.90 markus 1386: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1387:
1.85 markus 1388: packet_add_padding(64);
1.23 markus 1389: packet_send();
1.68 markus 1390: }
1391:
1.100 markus 1392: static int
1.105 deraadt 1393: ssh_keysign(Key *key, u_char **sigp, u_int *lenp,
1.100 markus 1394: u_char *data, u_int datalen)
1395: {
1396: Buffer b;
1.101 markus 1397: struct stat st;
1.100 markus 1398: pid_t pid;
1.103 markus 1399: int to[2], from[2], status, version = 2;
1.100 markus 1400:
1.109 markus 1401: debug2("ssh_keysign called");
1.100 markus 1402:
1.101 markus 1403: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.179 dtucker 1404: error("ssh_keysign: not installed: %s", strerror(errno));
1.101 markus 1405: return -1;
1406: }
1.100 markus 1407: if (fflush(stdout) != 0)
1408: error("ssh_keysign: fflush: %s", strerror(errno));
1409: if (pipe(to) < 0) {
1410: error("ssh_keysign: pipe: %s", strerror(errno));
1411: return -1;
1412: }
1413: if (pipe(from) < 0) {
1414: error("ssh_keysign: pipe: %s", strerror(errno));
1415: return -1;
1416: }
1417: if ((pid = fork()) < 0) {
1418: error("ssh_keysign: fork: %s", strerror(errno));
1419: return -1;
1420: }
1421: if (pid == 0) {
1.174 dtucker 1422: /* keep the socket on exec */
1423: fcntl(packet_get_connection_in(), F_SETFD, 0);
1.155 markus 1424: permanently_drop_suid(getuid());
1.100 markus 1425: close(from[0]);
1426: if (dup2(from[1], STDOUT_FILENO) < 0)
1427: fatal("ssh_keysign: dup2: %s", strerror(errno));
1428: close(to[1]);
1429: if (dup2(to[0], STDIN_FILENO) < 0)
1430: fatal("ssh_keysign: dup2: %s", strerror(errno));
1.103 markus 1431: close(from[1]);
1432: close(to[0]);
1.102 markus 1433: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0);
1.100 markus 1434: fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN,
1435: strerror(errno));
1436: }
1437: close(from[1]);
1438: close(to[0]);
1439:
1440: buffer_init(&b);
1.103 markus 1441: buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */
1.100 markus 1442: buffer_put_string(&b, data, datalen);
1.131 djm 1443: if (ssh_msg_send(to[1], version, &b) == -1)
1444: fatal("ssh_keysign: couldn't send request");
1.100 markus 1445:
1.110 djm 1446: if (ssh_msg_recv(from[0], &b) < 0) {
1.101 markus 1447: error("ssh_keysign: no reply");
1.134 markus 1448: buffer_free(&b);
1.100 markus 1449: return -1;
1450: }
1.101 markus 1451: close(from[0]);
1452: close(to[1]);
1453:
1.103 markus 1454: while (waitpid(pid, &status, 0) < 0)
1455: if (errno != EINTR)
1456: break;
1.101 markus 1457:
1.100 markus 1458: if (buffer_get_char(&b) != version) {
1.101 markus 1459: error("ssh_keysign: bad version");
1.134 markus 1460: buffer_free(&b);
1.100 markus 1461: return -1;
1462: }
1463: *sigp = buffer_get_string(&b, lenp);
1.134 markus 1464: buffer_free(&b);
1.100 markus 1465:
1466: return 0;
1467: }
1468:
1.68 markus 1469: int
1470: userauth_hostbased(Authctxt *authctxt)
1471: {
1472: Key *private = NULL;
1.100 markus 1473: Sensitive *sensitive = authctxt->sensitive;
1.68 markus 1474: Buffer b;
1475: u_char *signature, *blob;
1.179 dtucker 1476: char *chost, *pkalg, *p;
1.72 markus 1477: const char *service;
1.68 markus 1478: u_int blen, slen;
1.176 dtucker 1479: int ok, i, found = 0;
1.68 markus 1480:
1481: /* check for a useful key */
1.100 markus 1482: for (i = 0; i < sensitive->nkeys; i++) {
1483: private = sensitive->keys[i];
1.68 markus 1484: if (private && private->type != KEY_RSA1) {
1485: found = 1;
1486: /* we take and free the key */
1.100 markus 1487: sensitive->keys[i] = NULL;
1.68 markus 1488: break;
1489: }
1490: }
1491: if (!found) {
1.109 markus 1492: debug("No more client hostkeys for hostbased authentication.");
1.68 markus 1493: return 0;
1494: }
1495: if (key_to_blob(private, &blob, &blen) == 0) {
1496: key_free(private);
1497: return 0;
1498: }
1.84 markus 1499: /* figure out a name for the client host */
1.179 dtucker 1500: p = get_local_name(packet_get_connection_in());
1.84 markus 1501: if (p == NULL) {
1502: error("userauth_hostbased: cannot get local ipaddr/name");
1503: key_free(private);
1.197 djm 1504: free(blob);
1.84 markus 1505: return 0;
1506: }
1.150 djm 1507: xasprintf(&chost, "%s.", p);
1.84 markus 1508: debug2("userauth_hostbased: chost %s", chost);
1.197 djm 1509: free(p);
1.84 markus 1510:
1.72 markus 1511: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1512: authctxt->service;
1.68 markus 1513: pkalg = xstrdup(key_ssh_name(private));
1514: buffer_init(&b);
1515: /* construct data */
1.72 markus 1516: buffer_put_string(&b, session_id2, session_id2_len);
1.68 markus 1517: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1518: buffer_put_cstring(&b, authctxt->server_user);
1.72 markus 1519: buffer_put_cstring(&b, service);
1.68 markus 1520: buffer_put_cstring(&b, authctxt->method->name);
1521: buffer_put_cstring(&b, pkalg);
1522: buffer_put_string(&b, blob, blen);
1523: buffer_put_cstring(&b, chost);
1524: buffer_put_cstring(&b, authctxt->local_user);
1525: #ifdef DEBUG_PK
1526: buffer_dump(&b);
1527: #endif
1.100 markus 1528: if (sensitive->external_keysign)
1529: ok = ssh_keysign(private, &signature, &slen,
1530: buffer_ptr(&b), buffer_len(&b));
1531: else
1532: ok = key_sign(private, &signature, &slen,
1533: buffer_ptr(&b), buffer_len(&b));
1.68 markus 1534: key_free(private);
1535: buffer_free(&b);
1536: if (ok != 0) {
1537: error("key_sign failed");
1.197 djm 1538: free(chost);
1539: free(pkalg);
1540: free(blob);
1.68 markus 1541: return 0;
1542: }
1543: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1544: packet_put_cstring(authctxt->server_user);
1545: packet_put_cstring(authctxt->service);
1546: packet_put_cstring(authctxt->method->name);
1547: packet_put_cstring(pkalg);
1548: packet_put_string(blob, blen);
1549: packet_put_cstring(chost);
1550: packet_put_cstring(authctxt->local_user);
1551: packet_put_string(signature, slen);
1.204 ! djm 1552: explicit_bzero(signature, slen);
1.197 djm 1553: free(signature);
1554: free(chost);
1555: free(pkalg);
1556: free(blob);
1.68 markus 1557:
1558: packet_send();
1559: return 1;
1.23 markus 1560: }
1.170 djm 1561:
1.20 markus 1562: /* find auth method */
1563:
1564: /*
1565: * given auth method name, if configurable options permit this method fill
1566: * in auth_ident field and return true, otherwise return false.
1567: */
1.76 itojun 1568: static int
1.20 markus 1569: authmethod_is_enabled(Authmethod *method)
1570: {
1571: if (method == NULL)
1572: return 0;
1573: /* return false if options indicate this method is disabled */
1574: if (method->enabled == NULL || *method->enabled == 0)
1575: return 0;
1576: /* return false if batch mode is enabled but method needs interactive mode */
1577: if (method->batch_flag != NULL && *method->batch_flag != 0)
1578: return 0;
1579: return 1;
1580: }
1581:
1.76 itojun 1582: static Authmethod *
1.20 markus 1583: authmethod_lookup(const char *name)
1.1 markus 1584: {
1.20 markus 1585: Authmethod *method = NULL;
1586: if (name != NULL)
1587: for (method = authmethods; method->name != NULL; method++)
1588: if (strcmp(name, method->name) == 0)
1589: return method;
1590: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1591: return NULL;
1592: }
1.1 markus 1593:
1.53 markus 1594: /* XXX internal state */
1595: static Authmethod *current = NULL;
1596: static char *supported = NULL;
1597: static char *preferred = NULL;
1.105 deraadt 1598:
1.20 markus 1599: /*
1600: * Given the authentication method list sent by the server, return the
1601: * next method we should try. If the server initially sends a nil list,
1.67 markus 1602: * use a built-in default list.
1.41 stevesk 1603: */
1.76 itojun 1604: static Authmethod *
1.20 markus 1605: authmethod_get(char *authlist)
1606: {
1.53 markus 1607: char *name = NULL;
1.97 markus 1608: u_int next;
1.41 stevesk 1609:
1.20 markus 1610: /* Use a suitable default if we're passed a nil list. */
1611: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1612: authlist = options.preferred_authentications;
1.20 markus 1613:
1.53 markus 1614: if (supported == NULL || strcmp(authlist, supported) != 0) {
1615: debug3("start over, passed a different list %s", authlist);
1.197 djm 1616: free(supported);
1.53 markus 1617: supported = xstrdup(authlist);
1618: preferred = options.preferred_authentications;
1619: debug3("preferred %s", preferred);
1620: current = NULL;
1621: } else if (current != NULL && authmethod_is_enabled(current))
1622: return current;
1.20 markus 1623:
1.53 markus 1624: for (;;) {
1625: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1626: debug("No more authentication methods to try.");
1.53 markus 1627: current = NULL;
1628: return NULL;
1629: }
1630: preferred += next;
1.23 markus 1631: debug3("authmethod_lookup %s", name);
1.53 markus 1632: debug3("remaining preferred: %s", preferred);
1633: if ((current = authmethod_lookup(name)) != NULL &&
1634: authmethod_is_enabled(current)) {
1.23 markus 1635: debug3("authmethod_is_enabled %s", name);
1.109 markus 1636: debug("Next authentication method: %s", name);
1.197 djm 1637: free(name);
1.53 markus 1638: return current;
1.23 markus 1639: }
1.198 dtucker 1640: free(name);
1.1 markus 1641: }
1.53 markus 1642: }
1.1 markus 1643:
1.79 stevesk 1644: static char *
1.53 markus 1645: authmethods_get(void)
1646: {
1647: Authmethod *method = NULL;
1.93 markus 1648: Buffer b;
1649: char *list;
1.27 provos 1650:
1.93 markus 1651: buffer_init(&b);
1.53 markus 1652: for (method = authmethods; method->name != NULL; method++) {
1653: if (authmethod_is_enabled(method)) {
1.93 markus 1654: if (buffer_len(&b) > 0)
1655: buffer_append(&b, ",", 1);
1656: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1657: }
1658: }
1.93 markus 1659: buffer_append(&b, "\0", 1);
1660: list = xstrdup(buffer_ptr(&b));
1661: buffer_free(&b);
1662: return list;
1.1 markus 1663: }
1.170 djm 1664:
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