Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.261
1.261 ! markus 1: /* $OpenBSD: sshconnect2.c,v 1.260 2017/05/30 14:19:15 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"
1.246 djm 68: #include "utf8.h"
1.22 provos 69:
1.121 markus 70: #ifdef GSSAPI
71: #include "ssh-gss.h"
72: #endif
73:
1.1 markus 74: /* import */
75: extern char *client_version_string;
76: extern char *server_version_string;
77: extern Options options;
78:
79: /*
80: * SSH2 key exchange
81: */
82:
1.32 markus 83: u_char *session_id2 = NULL;
1.120 markus 84: u_int session_id2_len = 0;
1.1 markus 85:
1.61 markus 86: char *xxx_host;
87: struct sockaddr *xxx_hostaddr;
88:
1.76 itojun 89: static int
1.259 markus 90: verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
1.61 markus 91: {
1.75 markus 92: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1)
1.83 markus 93: fatal("Host key verification failed.");
1.61 markus 94: return 0;
95: }
96:
1.186 djm 97: static char *
98: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port)
99: {
100: char *oavail, *avail, *first, *last, *alg, *hostname, *ret;
101: size_t maxlen;
102: struct hostkeys *hostkeys;
103: int ktype;
1.188 djm 104: u_int i;
1.186 djm 105:
106: /* Find all hostkeys for this hostname */
107: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
108: hostkeys = init_hostkeys();
1.188 djm 109: for (i = 0; i < options.num_user_hostfiles; i++)
110: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i]);
111: for (i = 0; i < options.num_system_hostfiles; i++)
112: load_hostkeys(hostkeys, hostname, options.system_hostfiles[i]);
1.186 djm 113:
114: oavail = avail = xstrdup(KEX_DEFAULT_PK_ALG);
115: maxlen = strlen(avail) + 1;
116: first = xmalloc(maxlen);
117: last = xmalloc(maxlen);
118: *first = *last = '\0';
119:
120: #define ALG_APPEND(to, from) \
121: do { \
122: if (*to != '\0') \
123: strlcat(to, ",", maxlen); \
124: strlcat(to, from, maxlen); \
125: } while (0)
126:
127: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 128: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.186 djm 129: fatal("%s: unknown alg %s", __func__, alg);
130: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.214 djm 131: sshkey_type_plain(ktype), NULL))
1.186 djm 132: ALG_APPEND(first, alg);
133: else
134: ALG_APPEND(last, alg);
135: }
136: #undef ALG_APPEND
1.216 djm 137: xasprintf(&ret, "%s%s%s", first,
138: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 139: if (*first != '\0')
140: debug3("%s: prefer hostkeyalgs: %s", __func__, first);
141:
1.197 djm 142: free(first);
143: free(last);
144: free(hostname);
145: free(oavail);
1.186 djm 146: free_hostkeys(hostkeys);
147:
148: return ret;
149: }
150:
1.1 markus 151: void
1.186 djm 152: ssh_kex2(char *host, struct sockaddr *hostaddr, u_short port)
1.22 provos 153: {
1.205 markus 154: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.231 markus 155: char *s;
1.219 markus 156: struct kex *kex;
1.221 markus 157: int r;
1.61 markus 158:
159: xxx_host = host;
160: xxx_hostaddr = hostaddr;
1.22 provos 161:
1.231 markus 162: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
163: fatal("%s: kex_names_cat", __func__);
164: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
1.60 stevesk 165: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.226 djm 166: compat_cipher_proposal(options.ciphers);
1.60 stevesk 167: myproposal[PROPOSAL_ENC_ALGS_STOC] =
1.226 djm 168: compat_cipher_proposal(options.ciphers);
1.245 dtucker 169: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
170: myproposal[PROPOSAL_COMP_ALGS_STOC] = options.compression ?
1.250 djm 171: "zlib@openssh.com,zlib,none" : "none,zlib@openssh.com,zlib";
1.226 djm 172: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
173: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
174: if (options.hostkeyalgorithms != NULL) {
175: if (kex_assemble_names(KEX_DEFAULT_PK_ALG,
176: &options.hostkeyalgorithms) != 0)
177: fatal("%s: kex_assemble_namelist", __func__);
1.88 deraadt 178: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 179: compat_pkalg_proposal(options.hostkeyalgorithms);
1.226 djm 180: } else {
1.225 markus 181: /* Enforce default */
182: options.hostkeyalgorithms = xstrdup(KEX_DEFAULT_PK_ALG);
1.186 djm 183: /* Prefer algorithms that we already have keys for */
184: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.200 djm 185: compat_pkalg_proposal(
186: order_hostkeyalgs(host, hostaddr, port));
1.186 djm 187: }
1.115 markus 188:
1.196 dtucker 189: if (options.rekey_limit || options.rekey_interval)
1.254 dtucker 190: packet_set_rekey_limits(options.rekey_limit,
191: options.rekey_interval);
1.22 provos 192:
1.65 markus 193: /* start key exchange */
1.221 markus 194: if ((r = kex_setup(active_state, myproposal)) != 0)
195: fatal("kex_setup: %s", ssh_err(r));
1.219 markus 196: kex = active_state->kex;
1.207 markus 197: #ifdef WITH_OPENSSL
1.111 markus 198: kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
1.138 djm 199: kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
1.243 djm 200: kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
201: kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
202: kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client;
1.111 markus 203: kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
1.147 djm 204: kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.184 djm 205: kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
1.207 markus 206: #endif
1.199 markus 207: kex->kex[KEX_C25519_SHA256] = kexc25519_client;
1.61 markus 208: kex->client_version_string=client_version_string;
209: kex->server_version_string=server_version_string;
1.75 markus 210: kex->verify_host_key=&verify_host_key_callback;
1.22 provos 211:
1.219 markus 212: dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
1.173 andreas 213:
1.231 markus 214: /* remove ext-info from the KEX proposals for rekeying */
215: myproposal[PROPOSAL_KEX_ALGS] =
216: compat_kex_proposal(options.kex_algorithms);
217: if ((r = kex_prop2buf(kex->my, myproposal)) != 0)
218: fatal("kex_prop2buf: %s", ssh_err(r));
1.62 markus 219:
220: session_id2 = kex->session_id;
221: session_id2_len = kex->session_id_len;
1.22 provos 222:
223: #ifdef DEBUG_KEXDH
224: /* send 1st encrypted/maced/compressed message */
225: packet_start(SSH2_MSG_IGNORE);
226: packet_put_cstring("markus");
227: packet_send();
228: packet_write_wait();
229: #endif
1.1 markus 230: }
1.11 markus 231:
1.1 markus 232: /*
233: * Authenticate user
234: */
1.20 markus 235:
1.214 djm 236: typedef struct cauthctxt Authctxt;
237: typedef struct cauthmethod Authmethod;
1.117 markus 238: typedef struct identity Identity;
239: typedef struct idlist Idlist;
1.20 markus 240:
1.117 markus 241: struct identity {
242: TAILQ_ENTRY(identity) next;
1.214 djm 243: int agent_fd; /* >=0 if agent supports key */
244: struct sshkey *key; /* public/private key */
1.117 markus 245: char *filename; /* comment for agent-only keys */
246: int tried;
247: int isprivate; /* key points to the private key */
1.191 dtucker 248: int userprovided;
1.117 markus 249: };
250: TAILQ_HEAD(idlist, identity);
1.20 markus 251:
1.214 djm 252: struct cauthctxt {
1.20 markus 253: const char *server_user;
1.68 markus 254: const char *local_user;
1.20 markus 255: const char *host;
256: const char *service;
1.214 djm 257: struct cauthmethod *method;
1.183 djm 258: sig_atomic_t success;
1.51 markus 259: char *authlist;
1.214 djm 260: int attempt;
1.68 markus 261: /* pubkey */
1.214 djm 262: struct idlist keys;
263: int agent_fd;
1.68 markus 264: /* hostbased */
1.100 markus 265: Sensitive *sensitive;
1.223 djm 266: char *oktypes, *ktypes;
267: const char *active_ktype;
1.82 markus 268: /* kbd-interactive */
269: int info_req_seen;
1.121 markus 270: /* generic */
271: void *methoddata;
1.20 markus 272: };
1.214 djm 273:
274: struct cauthmethod {
1.20 markus 275: char *name; /* string to compare against server's list */
276: int (*userauth)(Authctxt *authctxt);
1.170 djm 277: void (*cleanup)(Authctxt *authctxt);
1.20 markus 278: int *enabled; /* flag in option struct that enables method */
279: int *batch_flag; /* flag in option struct that disables method */
280: };
281:
1.261 ! markus 282: int input_userauth_service_accept(int, u_int32_t, struct ssh *);
! 283: int input_userauth_ext_info(int, u_int32_t, struct ssh *);
! 284: int input_userauth_success(int, u_int32_t, struct ssh *);
! 285: int input_userauth_success_unexpected(int, u_int32_t, struct ssh *);
! 286: int input_userauth_failure(int, u_int32_t, struct ssh *);
! 287: int input_userauth_banner(int, u_int32_t, struct ssh *);
! 288: int input_userauth_error(int, u_int32_t, struct ssh *);
! 289: int input_userauth_info_req(int, u_int32_t, struct ssh *);
! 290: int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
! 291: int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
1.86 itojun 292:
293: int userauth_none(Authctxt *);
294: int userauth_pubkey(Authctxt *);
295: int userauth_passwd(Authctxt *);
296: int userauth_kbdint(Authctxt *);
297: int userauth_hostbased(Authctxt *);
1.20 markus 298:
1.121 markus 299: #ifdef GSSAPI
300: int userauth_gssapi(Authctxt *authctxt);
1.261 ! markus 301: int input_gssapi_response(int type, u_int32_t, struct ssh *);
! 302: int input_gssapi_token(int type, u_int32_t, struct ssh *);
! 303: int input_gssapi_hash(int type, u_int32_t, struct ssh *);
! 304: int input_gssapi_error(int, u_int32_t, struct ssh *);
! 305: int input_gssapi_errtok(int, u_int32_t, struct ssh *);
1.121 markus 306: #endif
307:
1.86 itojun 308: void userauth(Authctxt *, char *);
1.51 markus 309:
1.117 markus 310: static int sign_and_send_pubkey(Authctxt *, Identity *);
311: static void pubkey_prepare(Authctxt *);
312: static void pubkey_cleanup(Authctxt *);
1.251 djm 313: static void pubkey_reset(Authctxt *);
1.259 markus 314: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 315:
316: static Authmethod *authmethod_get(char *authlist);
317: static Authmethod *authmethod_lookup(const char *name);
318: static char *authmethods_get(void);
1.20 markus 319:
320: Authmethod authmethods[] = {
1.121 markus 321: #ifdef GSSAPI
1.132 markus 322: {"gssapi-with-mic",
1.121 markus 323: userauth_gssapi,
1.170 djm 324: NULL,
1.121 markus 325: &options.gss_authentication,
326: NULL},
327: #endif
1.81 markus 328: {"hostbased",
329: userauth_hostbased,
1.170 djm 330: NULL,
1.81 markus 331: &options.hostbased_authentication,
332: NULL},
1.20 markus 333: {"publickey",
334: userauth_pubkey,
1.170 djm 335: NULL,
1.28 markus 336: &options.pubkey_authentication,
1.20 markus 337: NULL},
1.81 markus 338: {"keyboard-interactive",
339: userauth_kbdint,
1.170 djm 340: NULL,
1.81 markus 341: &options.kbd_interactive_authentication,
342: &options.batch_mode},
1.20 markus 343: {"password",
344: userauth_passwd,
1.170 djm 345: NULL,
1.20 markus 346: &options.password_authentication,
1.23 markus 347: &options.batch_mode},
348: {"none",
349: userauth_none,
350: NULL,
1.170 djm 351: NULL,
1.23 markus 352: NULL},
1.170 djm 353: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 354: };
355:
356: void
1.68 markus 357: ssh_userauth2(const char *local_user, const char *server_user, char *host,
1.100 markus 358: Sensitive *sensitive)
1.20 markus 359: {
1.231 markus 360: struct ssh *ssh = active_state;
1.20 markus 361: Authctxt authctxt;
1.231 markus 362: int r;
1.39 markus 363:
1.73 markus 364: if (options.challenge_response_authentication)
1.39 markus 365: options.kbd_interactive_authentication = 1;
1.53 markus 366: if (options.preferred_authentications == NULL)
367: options.preferred_authentications = authmethods_get();
368:
1.20 markus 369: /* setup authentication context */
1.82 markus 370: memset(&authctxt, 0, sizeof(authctxt));
1.117 markus 371: pubkey_prepare(&authctxt);
1.20 markus 372: authctxt.server_user = server_user;
1.68 markus 373: authctxt.local_user = local_user;
1.20 markus 374: authctxt.host = host;
375: authctxt.service = "ssh-connection"; /* service name */
376: authctxt.success = 0;
1.23 markus 377: authctxt.method = authmethod_lookup("none");
1.51 markus 378: authctxt.authlist = NULL;
1.121 markus 379: authctxt.methoddata = NULL;
1.100 markus 380: authctxt.sensitive = sensitive;
1.223 djm 381: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 382: authctxt.info_req_seen = 0;
1.215 djm 383: authctxt.agent_fd = -1;
1.23 markus 384: if (authctxt.method == NULL)
385: fatal("ssh_userauth2: internal error: cannot send userauth none request");
1.20 markus 386:
1.231 markus 387: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
388: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
389: (r = sshpkt_send(ssh)) != 0)
390: fatal("%s: %s", __func__, ssh_err(r));
391:
1.260 markus 392: ssh->authctxt = &authctxt;
1.231 markus 393: ssh_dispatch_init(ssh, &input_userauth_error);
394: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
395: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.260 markus 396: ssh_dispatch_run(ssh, DISPATCH_BLOCK, &authctxt.success, ssh); /* loop until success */
397: ssh->authctxt = NULL;
1.20 markus 398:
1.117 markus 399: pubkey_cleanup(&authctxt);
1.231 markus 400: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 401:
1.248 dtucker 402: if (!authctxt.success)
403: fatal("Authentication failed.");
1.109 markus 404: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 405: }
1.119 markus 406:
1.231 markus 407: /* ARGSUSED */
408: int
1.261 ! markus 409: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 410: {
1.260 markus 411: Authctxt *authctxt = ssh->authctxt;
1.231 markus 412: int r;
413:
414: if (ssh_packet_remaining(ssh) > 0) {
415: char *reply;
416:
417: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
418: goto out;
419: debug2("service_accept: %s", reply);
420: free(reply);
421: } else {
422: debug2("buggy server: service_accept w/o service");
423: }
424: if ((r = sshpkt_get_end(ssh)) != 0)
425: goto out;
426: debug("SSH2_MSG_SERVICE_ACCEPT received");
427:
428: /* initial userauth request */
429: userauth_none(authctxt);
430:
431: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
432: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
433: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
434: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
435: r = 0;
436: out:
437: return r;
438: }
439:
440: /* ARGSUSED */
441: int
1.261 ! markus 442: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 443: {
1.261 ! markus 444: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 445: }
446:
1.20 markus 447: void
1.51 markus 448: userauth(Authctxt *authctxt, char *authlist)
449: {
1.170 djm 450: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
451: authctxt->method->cleanup(authctxt);
452:
1.197 djm 453: free(authctxt->methoddata);
454: authctxt->methoddata = NULL;
1.51 markus 455: if (authlist == NULL) {
456: authlist = authctxt->authlist;
457: } else {
1.197 djm 458: free(authctxt->authlist);
1.51 markus 459: authctxt->authlist = authlist;
460: }
461: for (;;) {
462: Authmethod *method = authmethod_get(authlist);
463: if (method == NULL)
464: fatal("Permission denied (%s).", authlist);
465: authctxt->method = method;
1.119 markus 466:
467: /* reset the per method handler */
468: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
469: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
470:
471: /* and try new method */
1.51 markus 472: if (method->userauth(authctxt) != 0) {
473: debug2("we sent a %s packet, wait for reply", method->name);
474: break;
475: } else {
476: debug2("we did not send a packet, disable method");
477: method->enabled = NULL;
478: }
479: }
480: }
1.105 deraadt 481:
1.169 djm 482: /* ARGSUSED */
1.218 markus 483: int
1.261 ! markus 484: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 485: {
1.35 markus 486: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 487: "type %d", type);
1.218 markus 488: return 0;
1.35 markus 489: }
1.105 deraadt 490:
1.169 djm 491: /* ARGSUSED */
1.218 markus 492: int
1.261 ! markus 493: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 494: {
1.246 djm 495: char *msg, *lang;
1.166 djm 496: u_int len;
1.126 deraadt 497:
1.246 djm 498: debug3("%s", __func__);
499: msg = packet_get_string(&len);
1.35 markus 500: lang = packet_get_string(NULL);
1.246 djm 501: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
502: fmprintf(stderr, "%s", msg);
503: free(msg);
1.197 djm 504: free(lang);
1.218 markus 505: return 0;
1.20 markus 506: }
1.105 deraadt 507:
1.169 djm 508: /* ARGSUSED */
1.218 markus 509: int
1.261 ! markus 510: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 511: {
1.260 markus 512: Authctxt *authctxt = ssh->authctxt;
1.172 djm 513:
1.20 markus 514: if (authctxt == NULL)
515: fatal("input_userauth_success: no authentication context");
1.197 djm 516: free(authctxt->authlist);
517: authctxt->authlist = NULL;
1.172 djm 518: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
519: authctxt->method->cleanup(authctxt);
1.197 djm 520: free(authctxt->methoddata);
521: authctxt->methoddata = NULL;
1.20 markus 522: authctxt->success = 1; /* break out */
1.218 markus 523: return 0;
1.20 markus 524: }
1.105 deraadt 525:
1.218 markus 526: int
1.261 ! markus 527: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 528: {
1.260 markus 529: Authctxt *authctxt = ssh->authctxt;
1.172 djm 530:
531: if (authctxt == NULL)
532: fatal("%s: no authentication context", __func__);
533:
534: fatal("Unexpected authentication success during %s.",
535: authctxt->method->name);
1.218 markus 536: return 0;
1.172 djm 537: }
538:
1.169 djm 539: /* ARGSUSED */
1.218 markus 540: int
1.261 ! markus 541: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 542: {
1.260 markus 543: Authctxt *authctxt = ssh->authctxt;
1.20 markus 544: char *authlist = NULL;
545: int partial;
546:
547: if (authctxt == NULL)
548: fatal("input_userauth_failure: no authentication context");
549:
1.23 markus 550: authlist = packet_get_string(NULL);
1.20 markus 551: partial = packet_get_char();
1.90 markus 552: packet_check_eom();
1.20 markus 553:
1.193 markus 554: if (partial != 0) {
1.247 dtucker 555: verbose("Authenticated with partial success.");
1.193 markus 556: /* reset state */
1.251 djm 557: pubkey_reset(authctxt);
1.193 markus 558: }
1.109 markus 559: debug("Authentications that can continue: %s", authlist);
1.20 markus 560:
1.51 markus 561: userauth(authctxt, authlist);
1.218 markus 562: return 0;
1.51 markus 563: }
1.169 djm 564:
565: /* ARGSUSED */
1.218 markus 566: int
1.261 ! markus 567: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 568: {
1.260 markus 569: Authctxt *authctxt = ssh->authctxt;
1.259 markus 570: struct sshkey *key = NULL;
1.117 markus 571: Identity *id = NULL;
1.51 markus 572: Buffer b;
1.96 markus 573: int pktype, sent = 0;
574: u_int alen, blen;
575: char *pkalg, *fp;
576: u_char *pkblob;
1.51 markus 577:
578: if (authctxt == NULL)
579: fatal("input_userauth_pk_ok: no authentication context");
580: if (datafellows & SSH_BUG_PKOK) {
581: /* this is similar to SSH_BUG_PKAUTH */
582: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
583: pkblob = packet_get_string(&blen);
584: buffer_init(&b);
585: buffer_append(&b, pkblob, blen);
586: pkalg = buffer_get_string(&b, &alen);
587: buffer_free(&b);
588: } else {
589: pkalg = packet_get_string(&alen);
590: pkblob = packet_get_string(&blen);
591: }
1.90 markus 592: packet_check_eom();
1.51 markus 593:
1.117 markus 594: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 595:
1.117 markus 596: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
597: debug("unknown pkalg %s", pkalg);
598: goto done;
599: }
600: if ((key = key_from_blob(pkblob, blen)) == NULL) {
601: debug("no key from blob. pkalg %s", pkalg);
602: goto done;
603: }
604: if (key->type != pktype) {
605: error("input_userauth_pk_ok: type mismatch "
606: "for decoded key (received %d, expected %d)",
607: key->type, pktype);
608: goto done;
609: }
1.222 djm 610: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
611: SSH_FP_DEFAULT)) == NULL)
612: goto done;
1.117 markus 613: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 614: free(fp);
1.117 markus 615:
1.127 markus 616: /*
617: * search keys in the reverse order, because last candidate has been
618: * moved to the end of the queue. this also avoids confusion by
619: * duplicate keys
620: */
1.136 henning 621: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 622: if (key_equal(key, id->key)) {
623: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 624: break;
625: }
1.117 markus 626: }
627: done:
1.51 markus 628: if (key != NULL)
629: key_free(key);
1.197 djm 630: free(pkalg);
631: free(pkblob);
1.51 markus 632:
1.106 deraadt 633: /* try another method if we did not send a packet */
1.51 markus 634: if (sent == 0)
635: userauth(authctxt, NULL);
1.218 markus 636: return 0;
1.20 markus 637: }
1.121 markus 638:
639: #ifdef GSSAPI
1.133 djm 640: int
1.121 markus 641: userauth_gssapi(Authctxt *authctxt)
642: {
643: Gssctxt *gssctxt = NULL;
1.128 avsm 644: static gss_OID_set gss_supported = NULL;
1.139 djm 645: static u_int mech = 0;
1.121 markus 646: OM_uint32 min;
647: int ok = 0;
648:
649: /* Try one GSSAPI method at a time, rather than sending them all at
650: * once. */
651:
1.128 avsm 652: if (gss_supported == NULL)
653: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 654:
655: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 656: while (mech < gss_supported->count && !ok) {
1.121 markus 657: /* My DER encoding requires length<128 */
1.128 avsm 658: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 659: ssh_gssapi_check_mechanism(&gssctxt,
660: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 661: ok = 1; /* Mechanism works */
662: } else {
663: mech++;
664: }
665: }
666:
1.161 djm 667: if (!ok)
1.139 djm 668: return 0;
1.121 markus 669:
670: authctxt->methoddata=(void *)gssctxt;
671:
672: packet_start(SSH2_MSG_USERAUTH_REQUEST);
673: packet_put_cstring(authctxt->server_user);
674: packet_put_cstring(authctxt->service);
675: packet_put_cstring(authctxt->method->name);
676:
677: packet_put_int(1);
678:
1.129 markus 679: packet_put_int((gss_supported->elements[mech].length) + 2);
680: packet_put_char(SSH_GSS_OIDTYPE);
681: packet_put_char(gss_supported->elements[mech].length);
682: packet_put_raw(gss_supported->elements[mech].elements,
683: gss_supported->elements[mech].length);
1.121 markus 684:
685: packet_send();
686:
687: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
688: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
689: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
690: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
691:
692: mech++; /* Move along to next candidate */
693:
694: return 1;
695: }
696:
1.130 markus 697: static OM_uint32
698: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
699: {
1.260 markus 700: struct ssh *ssh = ctxt;
701: Authctxt *authctxt = ssh->authctxt;
1.130 markus 702: Gssctxt *gssctxt = authctxt->methoddata;
703: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 704: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
705: gss_buffer_desc gssbuf;
1.132 markus 706: OM_uint32 status, ms, flags;
707: Buffer b;
1.133 djm 708:
1.130 markus 709: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 710: recv_tok, &send_tok, &flags);
1.130 markus 711:
712: if (send_tok.length > 0) {
713: if (GSS_ERROR(status))
714: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
715: else
716: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 717:
1.130 markus 718: packet_put_string(send_tok.value, send_tok.length);
719: packet_send();
720: gss_release_buffer(&ms, &send_tok);
721: }
1.133 djm 722:
1.130 markus 723: if (status == GSS_S_COMPLETE) {
1.132 markus 724: /* send either complete or MIC, depending on mechanism */
725: if (!(flags & GSS_C_INTEG_FLAG)) {
726: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
727: packet_send();
728: } else {
729: ssh_gssapi_buildmic(&b, authctxt->server_user,
730: authctxt->service, "gssapi-with-mic");
731:
732: gssbuf.value = buffer_ptr(&b);
733: gssbuf.length = buffer_len(&b);
1.133 djm 734:
1.132 markus 735: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 736:
1.132 markus 737: if (!GSS_ERROR(status)) {
738: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
739: packet_put_string(mic.value, mic.length);
1.133 djm 740:
1.132 markus 741: packet_send();
742: }
1.133 djm 743:
1.132 markus 744: buffer_free(&b);
745: gss_release_buffer(&ms, &mic);
1.133 djm 746: }
1.130 markus 747: }
1.133 djm 748:
1.130 markus 749: return status;
750: }
751:
1.169 djm 752: /* ARGSUSED */
1.220 djm 753: int
1.261 ! markus 754: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 755: {
1.260 markus 756: Authctxt *authctxt = ssh->authctxt;
1.121 markus 757: Gssctxt *gssctxt;
758: int oidlen;
759: char *oidv;
760:
761: if (authctxt == NULL)
762: fatal("input_gssapi_response: no authentication context");
763: gssctxt = authctxt->methoddata;
764:
765: /* Setup our OID */
766: oidv = packet_get_string(&oidlen);
767:
1.129 markus 768: if (oidlen <= 2 ||
769: oidv[0] != SSH_GSS_OIDTYPE ||
770: oidv[1] != oidlen - 2) {
1.197 djm 771: free(oidv);
1.129 markus 772: debug("Badly encoded mechanism OID received");
773: userauth(authctxt, NULL);
1.220 djm 774: return 0;
1.121 markus 775: }
1.129 markus 776:
777: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
778: fatal("Server returned different OID than expected");
1.121 markus 779:
780: packet_check_eom();
781:
1.197 djm 782: free(oidv);
1.121 markus 783:
1.130 markus 784: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 785: /* Start again with next method on list */
786: debug("Trying to start again");
787: userauth(authctxt, NULL);
1.220 djm 788: return 0;
1.121 markus 789: }
1.220 djm 790: return 0;
1.121 markus 791: }
792:
1.169 djm 793: /* ARGSUSED */
1.220 djm 794: int
1.261 ! markus 795: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 796: {
1.260 markus 797: Authctxt *authctxt = ssh->authctxt;
1.121 markus 798: gss_buffer_desc recv_tok;
1.130 markus 799: OM_uint32 status;
1.121 markus 800: u_int slen;
801:
802: if (authctxt == NULL)
803: fatal("input_gssapi_response: no authentication context");
804:
805: recv_tok.value = packet_get_string(&slen);
806: recv_tok.length = slen; /* safe typecast */
807:
808: packet_check_eom();
809:
1.130 markus 810: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 811:
1.197 djm 812: free(recv_tok.value);
1.121 markus 813:
814: if (GSS_ERROR(status)) {
815: /* Start again with the next method in the list */
816: userauth(authctxt, NULL);
1.220 djm 817: return 0;
1.121 markus 818: }
1.220 djm 819: return 0;
1.121 markus 820: }
821:
1.169 djm 822: /* ARGSUSED */
1.220 djm 823: int
1.261 ! markus 824: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 825: {
1.260 markus 826: Authctxt *authctxt = ssh->authctxt;
1.121 markus 827: Gssctxt *gssctxt;
828: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
829: gss_buffer_desc recv_tok;
1.194 djm 830: OM_uint32 ms;
1.123 deraadt 831: u_int len;
1.121 markus 832:
833: if (authctxt == NULL)
834: fatal("input_gssapi_response: no authentication context");
835: gssctxt = authctxt->methoddata;
836:
1.123 deraadt 837: recv_tok.value = packet_get_string(&len);
838: recv_tok.length = len;
1.121 markus 839:
840: packet_check_eom();
841:
842: /* Stick it into GSSAPI and see what it says */
1.194 djm 843: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 844: &recv_tok, &send_tok, NULL);
1.121 markus 845:
1.197 djm 846: free(recv_tok.value);
1.121 markus 847: gss_release_buffer(&ms, &send_tok);
848:
849: /* Server will be returning a failed packet after this one */
1.220 djm 850: return 0;
1.121 markus 851: }
852:
1.169 djm 853: /* ARGSUSED */
1.220 djm 854: int
1.261 ! markus 855: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 856: {
857: char *msg;
858: char *lang;
859:
1.194 djm 860: /* maj */(void)packet_get_int();
861: /* min */(void)packet_get_int();
1.121 markus 862: msg=packet_get_string(NULL);
863: lang=packet_get_string(NULL);
864:
865: packet_check_eom();
866:
1.143 stevesk 867: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 868: free(msg);
869: free(lang);
1.220 djm 870: return 0;
1.121 markus 871: }
872: #endif /* GSSAPI */
1.20 markus 873:
1.1 markus 874: int
1.23 markus 875: userauth_none(Authctxt *authctxt)
876: {
877: /* initial userauth request */
878: packet_start(SSH2_MSG_USERAUTH_REQUEST);
879: packet_put_cstring(authctxt->server_user);
880: packet_put_cstring(authctxt->service);
881: packet_put_cstring(authctxt->method->name);
882: packet_send();
883: return 1;
884: }
885:
886: int
1.20 markus 887: userauth_passwd(Authctxt *authctxt)
1.1 markus 888: {
1.6 markus 889: static int attempt = 0;
1.99 markus 890: char prompt[150];
1.1 markus 891: char *password;
1.175 dtucker 892: const char *host = options.host_key_alias ? options.host_key_alias :
893: authctxt->host;
1.6 markus 894:
1.13 todd 895: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 896: return 0;
1.13 todd 897:
1.87 deraadt 898: if (attempt != 1)
1.13 todd 899: error("Permission denied, please try again.");
1.1 markus 900:
1.43 itojun 901: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 902: authctxt->server_user, host);
1.1 markus 903: password = read_passphrase(prompt, 0);
904: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 905: packet_put_cstring(authctxt->server_user);
906: packet_put_cstring(authctxt->service);
1.23 markus 907: packet_put_cstring(authctxt->method->name);
1.1 markus 908: packet_put_char(0);
1.49 markus 909: packet_put_cstring(password);
1.204 djm 910: explicit_bzero(password, strlen(password));
1.197 djm 911: free(password);
1.85 markus 912: packet_add_padding(64);
1.1 markus 913: packet_send();
1.99 markus 914:
1.104 deraadt 915: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 916: &input_userauth_passwd_changereq);
917:
1.1 markus 918: return 1;
919: }
1.169 djm 920:
1.99 markus 921: /*
922: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
923: */
1.169 djm 924: /* ARGSUSED */
1.218 markus 925: int
1.261 ! markus 926: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 927: {
1.260 markus 928: Authctxt *authctxt = ssh->authctxt;
1.99 markus 929: char *info, *lang, *password = NULL, *retype = NULL;
930: char prompt[150];
1.252 djm 931: const char *host;
1.99 markus 932:
933: debug2("input_userauth_passwd_changereq");
934:
935: if (authctxt == NULL)
936: fatal("input_userauth_passwd_changereq: "
937: "no authentication context");
1.252 djm 938: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 939:
940: info = packet_get_string(NULL);
941: lang = packet_get_string(NULL);
942: if (strlen(info) > 0)
1.116 itojun 943: logit("%s", info);
1.197 djm 944: free(info);
945: free(lang);
1.99 markus 946: packet_start(SSH2_MSG_USERAUTH_REQUEST);
947: packet_put_cstring(authctxt->server_user);
948: packet_put_cstring(authctxt->service);
949: packet_put_cstring(authctxt->method->name);
950: packet_put_char(1); /* additional info */
1.104 deraadt 951: snprintf(prompt, sizeof(prompt),
1.99 markus 952: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 953: authctxt->server_user, host);
1.99 markus 954: password = read_passphrase(prompt, 0);
955: packet_put_cstring(password);
1.204 djm 956: explicit_bzero(password, strlen(password));
1.197 djm 957: free(password);
1.99 markus 958: password = NULL;
959: while (password == NULL) {
1.104 deraadt 960: snprintf(prompt, sizeof(prompt),
1.99 markus 961: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 962: authctxt->server_user, host);
1.99 markus 963: password = read_passphrase(prompt, RP_ALLOW_EOF);
964: if (password == NULL) {
965: /* bail out */
1.218 markus 966: return 0;
1.99 markus 967: }
1.104 deraadt 968: snprintf(prompt, sizeof(prompt),
1.99 markus 969: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 970: authctxt->server_user, host);
1.99 markus 971: retype = read_passphrase(prompt, 0);
972: if (strcmp(password, retype) != 0) {
1.204 djm 973: explicit_bzero(password, strlen(password));
1.197 djm 974: free(password);
1.116 itojun 975: logit("Mismatch; try again, EOF to quit.");
1.99 markus 976: password = NULL;
977: }
1.204 djm 978: explicit_bzero(retype, strlen(retype));
1.197 djm 979: free(retype);
1.99 markus 980: }
981: packet_put_cstring(password);
1.204 djm 982: explicit_bzero(password, strlen(password));
1.197 djm 983: free(password);
1.99 markus 984: packet_add_padding(64);
985: packet_send();
1.104 deraadt 986:
987: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 988: &input_userauth_passwd_changereq);
1.218 markus 989: return 0;
1.117 markus 990: }
991:
1.231 markus 992: static const char *
1.255 djm 993: key_sign_encode(const struct sshkey *key)
1.231 markus 994: {
995: struct ssh *ssh = active_state;
996:
1.255 djm 997: if (key->type == KEY_RSA) {
1.231 markus 998: switch (ssh->kex->rsa_sha2) {
999: case 256:
1000: return "rsa-sha2-256";
1001: case 512:
1002: return "rsa-sha2-512";
1003: }
1004: }
1.255 djm 1005: return key_ssh_name(key);
1.231 markus 1006: }
1007:
1.117 markus 1008: static int
1.214 djm 1009: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1010: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1011: {
1.259 markus 1012: struct sshkey *prv;
1.117 markus 1013: int ret;
1.99 markus 1014:
1.117 markus 1015: /* the agent supports this key */
1.255 djm 1016: if (id->key != NULL && id->agent_fd != -1)
1.214 djm 1017: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.255 djm 1018: data, datalen, key_sign_encode(id->key), compat);
1.214 djm 1019:
1.117 markus 1020: /*
1021: * we have already loaded the private key or
1022: * the private key is stored in external hardware
1023: */
1.255 djm 1024: if (id->key != NULL &&
1025: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT)))
1026: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
1027: key_sign_encode(id->key), compat));
1028:
1.117 markus 1029: /* load the private key from the file */
1.229 jcs 1030: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1031: return SSH_ERR_KEY_NOT_FOUND;
1.255 djm 1032: ret = sshkey_sign(prv, sigp, lenp, data, datalen,
1033: key_sign_encode(prv), compat);
1.214 djm 1034: sshkey_free(prv);
1.117 markus 1035: return (ret);
1.51 markus 1036: }
1037:
1.76 itojun 1038: static int
1.255 djm 1039: id_filename_matches(Identity *id, Identity *private_id)
1040: {
1041: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1042: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1043: size_t i, slen;
1044:
1045: if (strcmp(id->filename, private_id->filename) == 0)
1046: return 1;
1047: for (i = 0; suffixes[i]; i++) {
1048: slen = strlen(suffixes[i]);
1049: if (len > slen && plen == len - slen &&
1050: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1051: memcmp(id->filename, private_id->filename, plen) == 0)
1052: return 1;
1053: }
1054: return 0;
1055: }
1056:
1057: static int
1.117 markus 1058: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1059: {
1060: Buffer b;
1.227 djm 1061: Identity *private_id;
1.32 markus 1062: u_char *blob, *signature;
1.214 djm 1063: size_t slen;
1.227 djm 1064: u_int bloblen, skip = 0;
1065: int matched, ret = -1, have_sig = 1;
1.182 djm 1066: char *fp;
1.1 markus 1067:
1.222 djm 1068: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1069: SSH_FP_DEFAULT)) == NULL)
1070: return 0;
1.227 djm 1071: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1072: free(fp);
1.51 markus 1073:
1.117 markus 1074: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1075: /* we cannot handle this key */
1.30 markus 1076: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1077: return 0;
1078: }
1.1 markus 1079: /* data to be signed */
1080: buffer_init(&b);
1.26 markus 1081: if (datafellows & SSH_OLD_SESSIONID) {
1082: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1083: skip = session_id2_len;
1.26 markus 1084: } else {
1.14 markus 1085: buffer_put_string(&b, session_id2, session_id2_len);
1086: skip = buffer_len(&b);
1087: }
1.1 markus 1088: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1089: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1090: buffer_put_cstring(&b,
1.30 markus 1091: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1092: "ssh-userauth" :
1.20 markus 1093: authctxt->service);
1.30 markus 1094: if (datafellows & SSH_BUG_PKAUTH) {
1095: buffer_put_char(&b, have_sig);
1096: } else {
1097: buffer_put_cstring(&b, authctxt->method->name);
1098: buffer_put_char(&b, have_sig);
1.255 djm 1099: buffer_put_cstring(&b, key_sign_encode(id->key));
1.30 markus 1100: }
1.1 markus 1101: buffer_put_string(&b, blob, bloblen);
1102:
1.227 djm 1103: /*
1104: * If the key is an certificate, try to find a matching private key
1105: * and use it to complete the signature.
1.241 djm 1106: * If no such private key exists, fall back to trying the certificate
1107: * key itself in case it has a private half already loaded.
1.227 djm 1108: */
1109: if (key_is_cert(id->key)) {
1110: matched = 0;
1111: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1112: if (sshkey_equal_public(id->key, private_id->key) &&
1113: id->key->type != private_id->key->type) {
1114: id = private_id;
1115: matched = 1;
1116: break;
1117: }
1118: }
1.255 djm 1119: /*
1120: * Exact key matches are preferred, but also allow
1121: * filename matches for non-PKCS#11/agent keys that
1122: * didn't load public keys. This supports the case
1123: * of keeping just a private key file and public
1124: * certificate on disk.
1125: */
1126: if (!matched && !id->isprivate && id->agent_fd == -1 &&
1127: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1128: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1129: if (private_id->key == NULL &&
1130: id_filename_matches(id, private_id)) {
1131: id = private_id;
1132: matched = 1;
1133: break;
1134: }
1135: }
1136: }
1.227 djm 1137: if (matched) {
1138: debug2("%s: using private key \"%s\"%s for "
1139: "certificate", __func__, id->filename,
1140: id->agent_fd != -1 ? " from agent" : "");
1141: } else {
1.240 djm 1142: debug("%s: no separate private key for certificate "
1.227 djm 1143: "\"%s\"", __func__, id->filename);
1144: }
1145: }
1146:
1.1 markus 1147: /* generate signature */
1.117 markus 1148: ret = identity_sign(id, &signature, &slen,
1.214 djm 1149: buffer_ptr(&b), buffer_len(&b), datafellows);
1150: if (ret != 0) {
1.239 djm 1151: if (ret != SSH_ERR_KEY_NOT_FOUND)
1152: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1153: free(blob);
1.17 markus 1154: buffer_free(&b);
1155: return 0;
1156: }
1.28 markus 1157: #ifdef DEBUG_PK
1.1 markus 1158: buffer_dump(&b);
1159: #endif
1.30 markus 1160: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1161: buffer_clear(&b);
1162: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1163: skip = session_id2_len;
1.10 markus 1164: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1165: buffer_put_cstring(&b, authctxt->server_user);
1166: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1167: buffer_put_cstring(&b, authctxt->method->name);
1168: buffer_put_char(&b, have_sig);
1.30 markus 1169: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1170: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1171: buffer_put_string(&b, blob, bloblen);
1172: }
1.197 djm 1173: free(blob);
1.51 markus 1174:
1.1 markus 1175: /* append signature */
1176: buffer_put_string(&b, signature, slen);
1.197 djm 1177: free(signature);
1.1 markus 1178:
1179: /* skip session id and packet type */
1.14 markus 1180: if (buffer_len(&b) < skip + 1)
1.20 markus 1181: fatal("userauth_pubkey: internal error");
1.14 markus 1182: buffer_consume(&b, skip + 1);
1.1 markus 1183:
1184: /* put remaining data from buffer into packet */
1185: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1186: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1187: buffer_free(&b);
1188: packet_send();
1.17 markus 1189:
1190: return 1;
1.16 markus 1191: }
1192:
1.76 itojun 1193: static int
1.117 markus 1194: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1195: {
1.51 markus 1196: u_char *blob;
1.97 markus 1197: u_int bloblen, have_sig = 0;
1.20 markus 1198:
1.51 markus 1199: debug3("send_pubkey_test");
1.16 markus 1200:
1.117 markus 1201: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1202: /* we cannot handle this key */
1203: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1204: return 0;
1205: }
1.51 markus 1206: /* register callback for USERAUTH_PK_OK message */
1207: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1208:
1209: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1210: packet_put_cstring(authctxt->server_user);
1211: packet_put_cstring(authctxt->service);
1212: packet_put_cstring(authctxt->method->name);
1213: packet_put_char(have_sig);
1214: if (!(datafellows & SSH_BUG_PKAUTH))
1.255 djm 1215: packet_put_cstring(key_sign_encode(id->key));
1.51 markus 1216: packet_put_string(blob, bloblen);
1.197 djm 1217: free(blob);
1.51 markus 1218: packet_send();
1219: return 1;
1220: }
1221:
1.259 markus 1222: static struct sshkey *
1.229 jcs 1223: load_identity_file(Identity *id)
1.51 markus 1224: {
1.259 markus 1225: struct sshkey *private = NULL;
1.229 jcs 1226: char prompt[300], *passphrase, *comment;
1.215 djm 1227: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1228: struct stat st;
1.16 markus 1229:
1.229 jcs 1230: if (stat(id->filename, &st) < 0) {
1231: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1232: id->filename, strerror(errno));
1.52 markus 1233: return NULL;
1234: }
1.214 djm 1235: snprintf(prompt, sizeof prompt,
1.229 jcs 1236: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1237: for (i = 0; i <= options.number_of_password_prompts; i++) {
1238: if (i == 0)
1239: passphrase = "";
1240: else {
1.20 markus 1241: passphrase = read_passphrase(prompt, 0);
1.214 djm 1242: if (*passphrase == '\0') {
1.20 markus 1243: debug2("no passphrase given, try next key");
1.214 djm 1244: free(passphrase);
1245: break;
1246: }
1247: }
1.229 jcs 1248: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1249: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1250: case 0:
1251: break;
1252: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1253: if (options.batch_mode) {
1254: quit = 1;
1255: break;
1256: }
1.215 djm 1257: if (i != 0)
1258: debug2("bad passphrase given, try again...");
1.214 djm 1259: break;
1260: case SSH_ERR_SYSTEM_ERROR:
1261: if (errno == ENOENT) {
1262: debug2("Load key \"%s\": %s",
1.229 jcs 1263: id->filename, ssh_err(r));
1.51 markus 1264: quit = 1;
1.214 djm 1265: break;
1.20 markus 1266: }
1.214 djm 1267: /* FALLTHROUGH */
1268: default:
1.229 jcs 1269: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1270: quit = 1;
1271: break;
1272: }
1.230 djm 1273: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1274: !(id->key && id->isprivate))
1275: maybe_add_key_to_agent(id->filename, private, comment,
1276: passphrase);
1.214 djm 1277: if (i > 0) {
1.204 djm 1278: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1279: free(passphrase);
1.16 markus 1280: }
1.232 mmcc 1281: free(comment);
1.214 djm 1282: if (private != NULL || quit)
1283: break;
1.16 markus 1284: }
1.51 markus 1285: return private;
1286: }
1287:
1.117 markus 1288: /*
1289: * try keys in the following order:
1.227 djm 1290: * 1. certificates listed in the config file
1291: * 2. other input certificates
1292: * 3. agent keys that are found in the config file
1293: * 4. other agent keys
1294: * 5. keys that are only listed in the config file
1.117 markus 1295: */
1296: static void
1297: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1298: {
1.214 djm 1299: struct identity *id, *id2, *tmp;
1300: struct idlist agent, files, *preferred;
1301: struct sshkey *key;
1.230 djm 1302: int agent_fd = -1, i, r, found;
1.214 djm 1303: size_t j;
1304: struct ssh_identitylist *idlist;
1.51 markus 1305:
1.117 markus 1306: TAILQ_INIT(&agent); /* keys from the agent */
1307: TAILQ_INIT(&files); /* keys from the config file */
1308: preferred = &authctxt->keys;
1309: TAILQ_INIT(preferred); /* preferred order of keys */
1310:
1.190 djm 1311: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1312: for (i = 0; i < options.num_identity_files; i++) {
1313: key = options.identity_keys[i];
1.180 djm 1314: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1315: continue;
1316: options.identity_keys[i] = NULL;
1.150 djm 1317: id = xcalloc(1, sizeof(*id));
1.230 djm 1318: id->agent_fd = -1;
1.117 markus 1319: id->key = key;
1320: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1321: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1322: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1323: }
1.227 djm 1324: /* list of certificates specified by user */
1325: for (i = 0; i < options.num_certificate_files; i++) {
1326: key = options.certificates[i];
1327: if (!key_is_cert(key) || key->cert == NULL ||
1328: key->cert->type != SSH2_CERT_TYPE_USER)
1329: continue;
1330: id = xcalloc(1, sizeof(*id));
1.230 djm 1331: id->agent_fd = -1;
1.227 djm 1332: id->key = key;
1333: id->filename = xstrdup(options.certificate_files[i]);
1334: id->userprovided = options.certificate_file_userprovided[i];
1335: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1336: }
1337: /* list of keys supported by the agent */
1.214 djm 1338: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1339: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1340: debug("%s: ssh_get_authentication_socket: %s",
1341: __func__, ssh_err(r));
1.258 naddy 1342: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1343: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1344: debug("%s: ssh_fetch_identitylist: %s",
1345: __func__, ssh_err(r));
1.237 markus 1346: close(agent_fd);
1.214 djm 1347: } else {
1348: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1349: found = 0;
1350: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1351: /*
1352: * agent keys from the config file are
1353: * preferred
1354: */
1355: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1356: TAILQ_REMOVE(&files, id, next);
1357: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1358: id->agent_fd = agent_fd;
1.117 markus 1359: found = 1;
1360: break;
1361: }
1362: }
1.135 markus 1363: if (!found && !options.identities_only) {
1.150 djm 1364: id = xcalloc(1, sizeof(*id));
1.214 djm 1365: /* XXX "steals" key/comment from idlist */
1366: id->key = idlist->keys[j];
1367: id->filename = idlist->comments[j];
1368: idlist->keys[j] = NULL;
1369: idlist->comments[j] = NULL;
1370: id->agent_fd = agent_fd;
1.117 markus 1371: TAILQ_INSERT_TAIL(&agent, id, next);
1372: }
1373: }
1.214 djm 1374: ssh_free_identitylist(idlist);
1.117 markus 1375: /* append remaining agent keys */
1376: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1377: TAILQ_REMOVE(&agent, id, next);
1378: TAILQ_INSERT_TAIL(preferred, id, next);
1379: }
1.214 djm 1380: authctxt->agent_fd = agent_fd;
1.244 djm 1381: }
1382: /* Prefer PKCS11 keys that are explicitly listed */
1383: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1384: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1385: continue;
1386: found = 0;
1387: TAILQ_FOREACH(id2, &files, next) {
1388: if (id2->key == NULL ||
1389: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1390: continue;
1391: if (sshkey_equal(id->key, id2->key)) {
1392: TAILQ_REMOVE(&files, id, next);
1393: TAILQ_INSERT_TAIL(preferred, id, next);
1394: found = 1;
1395: break;
1396: }
1397: }
1398: /* If IdentitiesOnly set and key not found then don't use it */
1399: if (!found && options.identities_only) {
1400: TAILQ_REMOVE(&files, id, next);
1401: explicit_bzero(id, sizeof(*id));
1402: free(id);
1403: }
1.117 markus 1404: }
1405: /* append remaining keys from the config file */
1406: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1407: TAILQ_REMOVE(&files, id, next);
1408: TAILQ_INSERT_TAIL(preferred, id, next);
1409: }
1.228 djm 1410: /* finally, filter by PubkeyAcceptedKeyTypes */
1411: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1412: if (id->key != NULL &&
1413: match_pattern_list(sshkey_ssh_name(id->key),
1414: options.pubkey_key_types, 0) != 1) {
1415: debug("Skipping %s key %s - "
1416: "not in PubkeyAcceptedKeyTypes",
1417: sshkey_ssh_name(id->key), id->filename);
1418: TAILQ_REMOVE(preferred, id, next);
1419: sshkey_free(id->key);
1420: free(id->filename);
1421: memset(id, 0, sizeof(*id));
1422: continue;
1423: }
1.230 djm 1424: debug2("key: %s (%p)%s%s", id->filename, id->key,
1425: id->userprovided ? ", explicit" : "",
1426: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1427: }
1.17 markus 1428: }
1429:
1.117 markus 1430: static void
1431: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1432: {
1.117 markus 1433: Identity *id;
1.51 markus 1434:
1.214 djm 1435: if (authctxt->agent_fd != -1)
1436: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1437: for (id = TAILQ_FIRST(&authctxt->keys); id;
1438: id = TAILQ_FIRST(&authctxt->keys)) {
1439: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1440: sshkey_free(id->key);
1.197 djm 1441: free(id->filename);
1442: free(id);
1.117 markus 1443: }
1.1 markus 1444: }
1445:
1.251 djm 1446: static void
1447: pubkey_reset(Authctxt *authctxt)
1448: {
1449: Identity *id;
1450:
1451: TAILQ_FOREACH(id, &authctxt->keys, next)
1452: id->tried = 0;
1453: }
1454:
1.225 markus 1455: static int
1456: try_identity(Identity *id)
1457: {
1458: if (!id->key)
1459: return (0);
1460: if (key_type_plain(id->key->type) == KEY_RSA &&
1461: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1462: debug("Skipped %s key %s for RSA/MD5 server",
1463: key_type(id->key), id->filename);
1464: return (0);
1465: }
1.257 djm 1466: return 1;
1.225 markus 1467: }
1468:
1.20 markus 1469: int
1470: userauth_pubkey(Authctxt *authctxt)
1471: {
1.117 markus 1472: Identity *id;
1.20 markus 1473: int sent = 0;
1.256 djm 1474: char *fp;
1.20 markus 1475:
1.117 markus 1476: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1477: if (id->tried++)
1478: return (0);
1.127 markus 1479: /* move key to the end of the queue */
1.117 markus 1480: TAILQ_REMOVE(&authctxt->keys, id, next);
1481: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1482: /*
1483: * send a test message if we have the public key. for
1484: * encrypted keys we cannot do this and have to load the
1485: * private key instead
1486: */
1.200 djm 1487: if (id->key != NULL) {
1.225 markus 1488: if (try_identity(id)) {
1.256 djm 1489: if ((fp = sshkey_fingerprint(id->key,
1490: options.fingerprint_hash,
1491: SSH_FP_DEFAULT)) == NULL) {
1492: error("%s: sshkey_fingerprint failed",
1493: __func__);
1494: return 0;
1495: }
1496: debug("Offering public key: %s %s %s",
1497: sshkey_type(id->key), fp, id->filename);
1498: free(fp);
1.200 djm 1499: sent = send_pubkey_test(authctxt, id);
1500: }
1501: } else {
1.117 markus 1502: debug("Trying private key: %s", id->filename);
1.229 jcs 1503: id->key = load_identity_file(id);
1.117 markus 1504: if (id->key != NULL) {
1.225 markus 1505: if (try_identity(id)) {
1506: id->isprivate = 1;
1.200 djm 1507: sent = sign_and_send_pubkey(
1508: authctxt, id);
1509: }
1.117 markus 1510: key_free(id->key);
1511: id->key = NULL;
1.251 djm 1512: id->isprivate = 0;
1.51 markus 1513: }
1514: }
1.117 markus 1515: if (sent)
1516: return (sent);
1.28 markus 1517: }
1.117 markus 1518: return (0);
1.20 markus 1519: }
1520:
1.23 markus 1521: /*
1522: * Send userauth request message specifying keyboard-interactive method.
1523: */
1524: int
1525: userauth_kbdint(Authctxt *authctxt)
1526: {
1527: static int attempt = 0;
1528:
1529: if (attempt++ >= options.number_of_password_prompts)
1530: return 0;
1.82 markus 1531: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1532: if (attempt > 1 && !authctxt->info_req_seen) {
1533: debug3("userauth_kbdint: disable: no info_req_seen");
1534: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1535: return 0;
1536: }
1.23 markus 1537:
1538: debug2("userauth_kbdint");
1539: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1540: packet_put_cstring(authctxt->server_user);
1541: packet_put_cstring(authctxt->service);
1542: packet_put_cstring(authctxt->method->name);
1543: packet_put_cstring(""); /* lang */
1544: packet_put_cstring(options.kbd_interactive_devices ?
1545: options.kbd_interactive_devices : "");
1546: packet_send();
1547:
1548: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1549: return 1;
1550: }
1551:
1552: /*
1.46 markus 1553: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1554: */
1.218 markus 1555: int
1.261 ! markus 1556: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1557: {
1.260 markus 1558: Authctxt *authctxt = ssh->authctxt;
1.46 markus 1559: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1560: u_int num_prompts, i;
1.23 markus 1561: int echo = 0;
1562:
1563: debug2("input_userauth_info_req");
1564:
1565: if (authctxt == NULL)
1566: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1567:
1568: authctxt->info_req_seen = 1;
1.23 markus 1569:
1570: name = packet_get_string(NULL);
1571: inst = packet_get_string(NULL);
1572: lang = packet_get_string(NULL);
1573: if (strlen(name) > 0)
1.116 itojun 1574: logit("%s", name);
1.23 markus 1575: if (strlen(inst) > 0)
1.116 itojun 1576: logit("%s", inst);
1.197 djm 1577: free(name);
1578: free(inst);
1579: free(lang);
1.23 markus 1580:
1581: num_prompts = packet_get_int();
1582: /*
1583: * Begin to build info response packet based on prompts requested.
1584: * We commit to providing the correct number of responses, so if
1585: * further on we run into a problem that prevents this, we have to
1586: * be sure and clean this up and send a correct error response.
1587: */
1588: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1589: packet_put_int(num_prompts);
1590:
1.73 markus 1591: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1592: for (i = 0; i < num_prompts; i++) {
1593: prompt = packet_get_string(NULL);
1594: echo = packet_get_char();
1595:
1.77 markus 1596: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1597:
1.49 markus 1598: packet_put_cstring(response);
1.204 djm 1599: explicit_bzero(response, strlen(response));
1.197 djm 1600: free(response);
1601: free(prompt);
1.23 markus 1602: }
1.90 markus 1603: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1604:
1.85 markus 1605: packet_add_padding(64);
1.23 markus 1606: packet_send();
1.218 markus 1607: return 0;
1.68 markus 1608: }
1609:
1.100 markus 1610: static int
1.223 djm 1611: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1612: const u_char *data, size_t datalen)
1.100 markus 1613: {
1.223 djm 1614: struct sshbuf *b;
1.101 markus 1615: struct stat st;
1.100 markus 1616: pid_t pid;
1.223 djm 1617: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1618: u_char rversion = 0, version = 2;
1619: void (*osigchld)(int);
1.100 markus 1620:
1.223 djm 1621: *sigp = NULL;
1622: *lenp = 0;
1.100 markus 1623:
1.101 markus 1624: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1625: error("%s: not installed: %s", __func__, strerror(errno));
1626: return -1;
1627: }
1628: if (fflush(stdout) != 0) {
1629: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1630: return -1;
1631: }
1.100 markus 1632: if (pipe(to) < 0) {
1.223 djm 1633: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1634: return -1;
1635: }
1636: if (pipe(from) < 0) {
1.223 djm 1637: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1638: return -1;
1639: }
1640: if ((pid = fork()) < 0) {
1.223 djm 1641: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1642: return -1;
1643: }
1.223 djm 1644: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1645: if (pid == 0) {
1.174 dtucker 1646: /* keep the socket on exec */
1.223 djm 1647: fcntl(sock, F_SETFD, 0);
1.155 markus 1648: permanently_drop_suid(getuid());
1.100 markus 1649: close(from[0]);
1650: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1651: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1652: close(to[1]);
1653: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1654: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1655: close(from[1]);
1656: close(to[0]);
1.223 djm 1657: /* Close everything but stdio and the socket */
1658: for (i = STDERR_FILENO + 1; i < sock; i++)
1659: close(i);
1660: closefrom(sock + 1);
1661: debug3("%s: [child] pid=%ld, exec %s",
1662: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1663: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1664: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1665: strerror(errno));
1666: }
1667: close(from[1]);
1668: close(to[0]);
1669:
1.223 djm 1670: if ((b = sshbuf_new()) == NULL)
1671: fatal("%s: sshbuf_new failed", __func__);
1672: /* send # of sock, data to be signed */
1.253 djm 1673: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 1674: (r = sshbuf_put_string(b, data, datalen)) != 0)
1675: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1676: if (ssh_msg_send(to[1], version, b) == -1)
1677: fatal("%s: couldn't send request", __func__);
1678: sshbuf_reset(b);
1679: r = ssh_msg_recv(from[0], b);
1.101 markus 1680: close(from[0]);
1681: close(to[1]);
1.223 djm 1682: if (r < 0) {
1683: error("%s: no reply", __func__);
1684: goto fail;
1685: }
1.101 markus 1686:
1.223 djm 1687: errno = 0;
1688: while (waitpid(pid, &status, 0) < 0) {
1689: if (errno != EINTR) {
1690: error("%s: waitpid %ld: %s",
1691: __func__, (long)pid, strerror(errno));
1692: goto fail;
1693: }
1694: }
1695: if (!WIFEXITED(status)) {
1696: error("%s: exited abnormally", __func__);
1697: goto fail;
1698: }
1699: if (WEXITSTATUS(status) != 0) {
1700: error("%s: exited with status %d",
1701: __func__, WEXITSTATUS(status));
1702: goto fail;
1703: }
1704: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1705: error("%s: buffer error: %s", __func__, ssh_err(r));
1706: goto fail;
1707: }
1708: if (rversion != version) {
1709: error("%s: bad version", __func__);
1710: goto fail;
1711: }
1712: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1713: error("%s: buffer error: %s", __func__, ssh_err(r));
1714: fail:
1715: signal(SIGCHLD, osigchld);
1716: sshbuf_free(b);
1.100 markus 1717: return -1;
1718: }
1.223 djm 1719: signal(SIGCHLD, osigchld);
1720: sshbuf_free(b);
1.100 markus 1721:
1722: return 0;
1723: }
1724:
1.68 markus 1725: int
1726: userauth_hostbased(Authctxt *authctxt)
1727: {
1.223 djm 1728: struct ssh *ssh = active_state;
1729: struct sshkey *private = NULL;
1730: struct sshbuf *b = NULL;
1.72 markus 1731: const char *service;
1.223 djm 1732: u_char *sig = NULL, *keyblob = NULL;
1733: char *fp = NULL, *chost = NULL, *lname = NULL;
1734: size_t siglen = 0, keylen = 0;
1735: int i, r, success = 0;
1736:
1737: if (authctxt->ktypes == NULL) {
1738: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1739: authctxt->ktypes = authctxt->oktypes;
1740: }
1.213 djm 1741:
1.223 djm 1742: /*
1743: * Work through each listed type pattern in HostbasedKeyTypes,
1744: * trying each hostkey that matches the type in turn.
1745: */
1746: for (;;) {
1747: if (authctxt->active_ktype == NULL)
1748: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1749: if (authctxt->active_ktype == NULL ||
1750: *authctxt->active_ktype == '\0')
1751: break;
1752: debug3("%s: trying key type %s", __func__,
1753: authctxt->active_ktype);
1.68 markus 1754:
1.223 djm 1755: /* check for a useful key */
1756: private = NULL;
1757: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1758: if (authctxt->sensitive->keys[i] == NULL ||
1759: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1760: continue;
1761: if (match_pattern_list(
1762: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1763: authctxt->active_ktype, 0) != 1)
1.223 djm 1764: continue;
1.68 markus 1765: /* we take and free the key */
1.223 djm 1766: private = authctxt->sensitive->keys[i];
1767: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1768: break;
1769: }
1.223 djm 1770: /* Found one */
1771: if (private != NULL)
1772: break;
1773: /* No more keys of this type; advance */
1774: authctxt->active_ktype = NULL;
1.68 markus 1775: }
1.223 djm 1776: if (private == NULL) {
1777: free(authctxt->oktypes);
1778: authctxt->oktypes = authctxt->ktypes = NULL;
1779: authctxt->active_ktype = NULL;
1.109 markus 1780: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1781: goto out;
1.68 markus 1782: }
1.211 djm 1783:
1.223 djm 1784: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1785: SSH_FP_DEFAULT)) == NULL) {
1786: error("%s: sshkey_fingerprint failed", __func__);
1787: goto out;
1.68 markus 1788: }
1.223 djm 1789: debug("%s: trying hostkey %s %s",
1790: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1791:
1.84 markus 1792: /* figure out a name for the client host */
1.223 djm 1793: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1794: error("%s: cannot get local ipaddr/name", __func__);
1795: goto out;
1.84 markus 1796: }
1.223 djm 1797:
1798: /* XXX sshbuf_put_stringf? */
1799: xasprintf(&chost, "%s.", lname);
1800: debug2("%s: chost %s", __func__, chost);
1.84 markus 1801:
1.72 markus 1802: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1803: authctxt->service;
1.223 djm 1804:
1.68 markus 1805: /* construct data */
1.223 djm 1806: if ((b = sshbuf_new()) == NULL) {
1807: error("%s: sshbuf_new failed", __func__);
1808: goto out;
1809: }
1810: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1811: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1812: goto out;
1813: }
1814: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1815: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1816: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1817: (r = sshbuf_put_cstring(b, service)) != 0 ||
1818: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1819: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1820: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1821: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1822: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1823: error("%s: buffer error: %s", __func__, ssh_err(r));
1824: goto out;
1825: }
1826:
1.68 markus 1827: #ifdef DEBUG_PK
1.223 djm 1828: sshbuf_dump(b, stderr);
1.68 markus 1829: #endif
1.223 djm 1830: if (authctxt->sensitive->external_keysign)
1831: r = ssh_keysign(private, &sig, &siglen,
1832: sshbuf_ptr(b), sshbuf_len(b));
1833: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1834: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1835: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1836: if (r != 0) {
1837: error("sign using hostkey %s %s failed",
1838: sshkey_ssh_name(private), fp);
1839: goto out;
1840: }
1841: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1842: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1843: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1844: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1845: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1846: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1847: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1848: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1849: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1850: (r = sshpkt_send(ssh)) != 0) {
1851: error("%s: packet error: %s", __func__, ssh_err(r));
1852: goto out;
1853: }
1854: success = 1;
1855:
1856: out:
1857: if (sig != NULL) {
1858: explicit_bzero(sig, siglen);
1859: free(sig);
1.68 markus 1860: }
1.223 djm 1861: free(keyblob);
1862: free(lname);
1863: free(fp);
1.197 djm 1864: free(chost);
1.223 djm 1865: sshkey_free(private);
1866: sshbuf_free(b);
1.68 markus 1867:
1.223 djm 1868: return success;
1.23 markus 1869: }
1.170 djm 1870:
1.20 markus 1871: /* find auth method */
1872:
1873: /*
1874: * given auth method name, if configurable options permit this method fill
1875: * in auth_ident field and return true, otherwise return false.
1876: */
1.76 itojun 1877: static int
1.20 markus 1878: authmethod_is_enabled(Authmethod *method)
1879: {
1880: if (method == NULL)
1881: return 0;
1882: /* return false if options indicate this method is disabled */
1883: if (method->enabled == NULL || *method->enabled == 0)
1884: return 0;
1885: /* return false if batch mode is enabled but method needs interactive mode */
1886: if (method->batch_flag != NULL && *method->batch_flag != 0)
1887: return 0;
1888: return 1;
1889: }
1890:
1.76 itojun 1891: static Authmethod *
1.20 markus 1892: authmethod_lookup(const char *name)
1.1 markus 1893: {
1.20 markus 1894: Authmethod *method = NULL;
1895: if (name != NULL)
1896: for (method = authmethods; method->name != NULL; method++)
1897: if (strcmp(name, method->name) == 0)
1898: return method;
1899: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1900: return NULL;
1901: }
1.1 markus 1902:
1.53 markus 1903: /* XXX internal state */
1904: static Authmethod *current = NULL;
1905: static char *supported = NULL;
1906: static char *preferred = NULL;
1.105 deraadt 1907:
1.20 markus 1908: /*
1909: * Given the authentication method list sent by the server, return the
1910: * next method we should try. If the server initially sends a nil list,
1.67 markus 1911: * use a built-in default list.
1.41 stevesk 1912: */
1.76 itojun 1913: static Authmethod *
1.20 markus 1914: authmethod_get(char *authlist)
1915: {
1.53 markus 1916: char *name = NULL;
1.97 markus 1917: u_int next;
1.41 stevesk 1918:
1.20 markus 1919: /* Use a suitable default if we're passed a nil list. */
1920: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1921: authlist = options.preferred_authentications;
1.20 markus 1922:
1.53 markus 1923: if (supported == NULL || strcmp(authlist, supported) != 0) {
1924: debug3("start over, passed a different list %s", authlist);
1.197 djm 1925: free(supported);
1.53 markus 1926: supported = xstrdup(authlist);
1927: preferred = options.preferred_authentications;
1928: debug3("preferred %s", preferred);
1929: current = NULL;
1930: } else if (current != NULL && authmethod_is_enabled(current))
1931: return current;
1.20 markus 1932:
1.53 markus 1933: for (;;) {
1934: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1935: debug("No more authentication methods to try.");
1.53 markus 1936: current = NULL;
1937: return NULL;
1938: }
1939: preferred += next;
1.23 markus 1940: debug3("authmethod_lookup %s", name);
1.53 markus 1941: debug3("remaining preferred: %s", preferred);
1942: if ((current = authmethod_lookup(name)) != NULL &&
1943: authmethod_is_enabled(current)) {
1.23 markus 1944: debug3("authmethod_is_enabled %s", name);
1.109 markus 1945: debug("Next authentication method: %s", name);
1.197 djm 1946: free(name);
1.53 markus 1947: return current;
1.23 markus 1948: }
1.198 dtucker 1949: free(name);
1.1 markus 1950: }
1.53 markus 1951: }
1.1 markus 1952:
1.79 stevesk 1953: static char *
1.53 markus 1954: authmethods_get(void)
1955: {
1956: Authmethod *method = NULL;
1.93 markus 1957: Buffer b;
1958: char *list;
1.27 provos 1959:
1.93 markus 1960: buffer_init(&b);
1.53 markus 1961: for (method = authmethods; method->name != NULL; method++) {
1962: if (authmethod_is_enabled(method)) {
1.93 markus 1963: if (buffer_len(&b) > 0)
1964: buffer_append(&b, ",", 1);
1965: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1966: }
1967: }
1.242 djm 1968: if ((list = sshbuf_dup_string(&b)) == NULL)
1969: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1970: buffer_free(&b);
1971: return list;
1.1 markus 1972: }
1.170 djm 1973: