Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.260
1.260 ! markus 1: /* $OpenBSD: sshconnect2.c,v 1.259 2017/05/30 08:52:20 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:
1.231 markus 282: int input_userauth_service_accept(int, u_int32_t, void *);
283: int input_userauth_ext_info(int, u_int32_t, void *);
1.218 markus 284: int input_userauth_success(int, u_int32_t, void *);
285: int input_userauth_success_unexpected(int, u_int32_t, void *);
286: int input_userauth_failure(int, u_int32_t, void *);
287: int input_userauth_banner(int, u_int32_t, void *);
288: int input_userauth_error(int, u_int32_t, void *);
289: int input_userauth_info_req(int, u_int32_t, void *);
290: int input_userauth_pk_ok(int, u_int32_t, void *);
291: int input_userauth_passwd_changereq(int, u_int32_t, void *);
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);
1.218 markus 301: int input_gssapi_response(int type, u_int32_t, void *);
302: int input_gssapi_token(int type, u_int32_t, void *);
303: int input_gssapi_hash(int type, u_int32_t, void *);
304: int input_gssapi_error(int, u_int32_t, void *);
305: int input_gssapi_errtok(int, u_int32_t, void *);
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
409: input_userauth_service_accept(int type, u_int32_t seqnr, void *ctxt)
410: {
1.260 ! markus 411: struct ssh *ssh = ctxt;
! 412: Authctxt *authctxt = ssh->authctxt;
1.231 markus 413: int r;
414:
415: if (ssh_packet_remaining(ssh) > 0) {
416: char *reply;
417:
418: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
419: goto out;
420: debug2("service_accept: %s", reply);
421: free(reply);
422: } else {
423: debug2("buggy server: service_accept w/o service");
424: }
425: if ((r = sshpkt_get_end(ssh)) != 0)
426: goto out;
427: debug("SSH2_MSG_SERVICE_ACCEPT received");
428:
429: /* initial userauth request */
430: userauth_none(authctxt);
431:
432: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
433: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
434: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
435: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
436: r = 0;
437: out:
438: return r;
439: }
440:
441: /* ARGSUSED */
442: int
443: input_userauth_ext_info(int type, u_int32_t seqnr, void *ctxt)
444: {
1.260 ! markus 445: return kex_input_ext_info(type, seqnr, ctxt);
1.231 markus 446: }
447:
1.20 markus 448: void
1.51 markus 449: userauth(Authctxt *authctxt, char *authlist)
450: {
1.170 djm 451: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
452: authctxt->method->cleanup(authctxt);
453:
1.197 djm 454: free(authctxt->methoddata);
455: authctxt->methoddata = NULL;
1.51 markus 456: if (authlist == NULL) {
457: authlist = authctxt->authlist;
458: } else {
1.197 djm 459: free(authctxt->authlist);
1.51 markus 460: authctxt->authlist = authlist;
461: }
462: for (;;) {
463: Authmethod *method = authmethod_get(authlist);
464: if (method == NULL)
465: fatal("Permission denied (%s).", authlist);
466: authctxt->method = method;
1.119 markus 467:
468: /* reset the per method handler */
469: dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN,
470: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
471:
472: /* and try new method */
1.51 markus 473: if (method->userauth(authctxt) != 0) {
474: debug2("we sent a %s packet, wait for reply", method->name);
475: break;
476: } else {
477: debug2("we did not send a packet, disable method");
478: method->enabled = NULL;
479: }
480: }
481: }
1.105 deraadt 482:
1.169 djm 483: /* ARGSUSED */
1.218 markus 484: int
1.92 markus 485: input_userauth_error(int type, u_int32_t seq, void *ctxt)
1.20 markus 486: {
1.35 markus 487: fatal("input_userauth_error: bad message during authentication: "
1.140 djm 488: "type %d", type);
1.218 markus 489: return 0;
1.35 markus 490: }
1.105 deraadt 491:
1.169 djm 492: /* ARGSUSED */
1.218 markus 493: int
1.92 markus 494: input_userauth_banner(int type, u_int32_t seq, void *ctxt)
1.35 markus 495: {
1.246 djm 496: char *msg, *lang;
1.166 djm 497: u_int len;
1.126 deraadt 498:
1.246 djm 499: debug3("%s", __func__);
500: msg = packet_get_string(&len);
1.35 markus 501: lang = packet_get_string(NULL);
1.246 djm 502: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
503: fmprintf(stderr, "%s", msg);
504: free(msg);
1.197 djm 505: free(lang);
1.218 markus 506: return 0;
1.20 markus 507: }
1.105 deraadt 508:
1.169 djm 509: /* ARGSUSED */
1.218 markus 510: int
1.92 markus 511: input_userauth_success(int type, u_int32_t seq, void *ctxt)
1.20 markus 512: {
1.260 ! markus 513: struct ssh *ssh = ctxt;
! 514: Authctxt *authctxt = ssh->authctxt;
1.172 djm 515:
1.20 markus 516: if (authctxt == NULL)
517: fatal("input_userauth_success: no authentication context");
1.197 djm 518: free(authctxt->authlist);
519: authctxt->authlist = NULL;
1.172 djm 520: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
521: authctxt->method->cleanup(authctxt);
1.197 djm 522: free(authctxt->methoddata);
523: authctxt->methoddata = NULL;
1.20 markus 524: authctxt->success = 1; /* break out */
1.218 markus 525: return 0;
1.20 markus 526: }
1.105 deraadt 527:
1.218 markus 528: int
1.172 djm 529: input_userauth_success_unexpected(int type, u_int32_t seq, void *ctxt)
530: {
1.260 ! markus 531: struct ssh *ssh = ctxt;
! 532: Authctxt *authctxt = ssh->authctxt;
1.172 djm 533:
534: if (authctxt == NULL)
535: fatal("%s: no authentication context", __func__);
536:
537: fatal("Unexpected authentication success during %s.",
538: authctxt->method->name);
1.218 markus 539: return 0;
1.172 djm 540: }
541:
1.169 djm 542: /* ARGSUSED */
1.218 markus 543: int
1.92 markus 544: input_userauth_failure(int type, u_int32_t seq, void *ctxt)
1.20 markus 545: {
1.260 ! markus 546: struct ssh *ssh = ctxt;
! 547: Authctxt *authctxt = ssh->authctxt;
1.20 markus 548: char *authlist = NULL;
549: int partial;
550:
551: if (authctxt == NULL)
552: fatal("input_userauth_failure: no authentication context");
553:
1.23 markus 554: authlist = packet_get_string(NULL);
1.20 markus 555: partial = packet_get_char();
1.90 markus 556: packet_check_eom();
1.20 markus 557:
1.193 markus 558: if (partial != 0) {
1.247 dtucker 559: verbose("Authenticated with partial success.");
1.193 markus 560: /* reset state */
1.251 djm 561: pubkey_reset(authctxt);
1.193 markus 562: }
1.109 markus 563: debug("Authentications that can continue: %s", authlist);
1.20 markus 564:
1.51 markus 565: userauth(authctxt, authlist);
1.218 markus 566: return 0;
1.51 markus 567: }
1.169 djm 568:
569: /* ARGSUSED */
1.218 markus 570: int
1.92 markus 571: input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt)
1.51 markus 572: {
1.260 ! markus 573: struct ssh *ssh = ctxt;
! 574: Authctxt *authctxt = ssh->authctxt;
1.259 markus 575: struct sshkey *key = NULL;
1.117 markus 576: Identity *id = NULL;
1.51 markus 577: Buffer b;
1.96 markus 578: int pktype, sent = 0;
579: u_int alen, blen;
580: char *pkalg, *fp;
581: u_char *pkblob;
1.51 markus 582:
583: if (authctxt == NULL)
584: fatal("input_userauth_pk_ok: no authentication context");
585: if (datafellows & SSH_BUG_PKOK) {
586: /* this is similar to SSH_BUG_PKAUTH */
587: debug2("input_userauth_pk_ok: SSH_BUG_PKOK");
588: pkblob = packet_get_string(&blen);
589: buffer_init(&b);
590: buffer_append(&b, pkblob, blen);
591: pkalg = buffer_get_string(&b, &alen);
592: buffer_free(&b);
593: } else {
594: pkalg = packet_get_string(&alen);
595: pkblob = packet_get_string(&blen);
596: }
1.90 markus 597: packet_check_eom();
1.51 markus 598:
1.117 markus 599: debug("Server accepts key: pkalg %s blen %u", pkalg, blen);
1.51 markus 600:
1.117 markus 601: if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) {
602: debug("unknown pkalg %s", pkalg);
603: goto done;
604: }
605: if ((key = key_from_blob(pkblob, blen)) == NULL) {
606: debug("no key from blob. pkalg %s", pkalg);
607: goto done;
608: }
609: if (key->type != pktype) {
610: error("input_userauth_pk_ok: type mismatch "
611: "for decoded key (received %d, expected %d)",
612: key->type, pktype);
613: goto done;
614: }
1.222 djm 615: if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
616: SSH_FP_DEFAULT)) == NULL)
617: goto done;
1.117 markus 618: debug2("input_userauth_pk_ok: fp %s", fp);
1.197 djm 619: free(fp);
1.117 markus 620:
1.127 markus 621: /*
622: * search keys in the reverse order, because last candidate has been
623: * moved to the end of the queue. this also avoids confusion by
624: * duplicate keys
625: */
1.136 henning 626: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.117 markus 627: if (key_equal(key, id->key)) {
628: sent = sign_and_send_pubkey(authctxt, id);
1.51 markus 629: break;
630: }
1.117 markus 631: }
632: done:
1.51 markus 633: if (key != NULL)
634: key_free(key);
1.197 djm 635: free(pkalg);
636: free(pkblob);
1.51 markus 637:
1.106 deraadt 638: /* try another method if we did not send a packet */
1.51 markus 639: if (sent == 0)
640: userauth(authctxt, NULL);
1.218 markus 641: return 0;
1.20 markus 642: }
1.121 markus 643:
644: #ifdef GSSAPI
1.133 djm 645: int
1.121 markus 646: userauth_gssapi(Authctxt *authctxt)
647: {
648: Gssctxt *gssctxt = NULL;
1.128 avsm 649: static gss_OID_set gss_supported = NULL;
1.139 djm 650: static u_int mech = 0;
1.121 markus 651: OM_uint32 min;
652: int ok = 0;
653:
654: /* Try one GSSAPI method at a time, rather than sending them all at
655: * once. */
656:
1.128 avsm 657: if (gss_supported == NULL)
658: gss_indicate_mechs(&min, &gss_supported);
1.121 markus 659:
660: /* Check to see if the mechanism is usable before we offer it */
1.128 avsm 661: while (mech < gss_supported->count && !ok) {
1.121 markus 662: /* My DER encoding requires length<128 */
1.128 avsm 663: if (gss_supported->elements[mech].length < 128 &&
1.161 djm 664: ssh_gssapi_check_mechanism(&gssctxt,
665: &gss_supported->elements[mech], authctxt->host)) {
1.121 markus 666: ok = 1; /* Mechanism works */
667: } else {
668: mech++;
669: }
670: }
671:
1.161 djm 672: if (!ok)
1.139 djm 673: return 0;
1.121 markus 674:
675: authctxt->methoddata=(void *)gssctxt;
676:
677: packet_start(SSH2_MSG_USERAUTH_REQUEST);
678: packet_put_cstring(authctxt->server_user);
679: packet_put_cstring(authctxt->service);
680: packet_put_cstring(authctxt->method->name);
681:
682: packet_put_int(1);
683:
1.129 markus 684: packet_put_int((gss_supported->elements[mech].length) + 2);
685: packet_put_char(SSH_GSS_OIDTYPE);
686: packet_put_char(gss_supported->elements[mech].length);
687: packet_put_raw(gss_supported->elements[mech].elements,
688: gss_supported->elements[mech].length);
1.121 markus 689:
690: packet_send();
691:
692: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
693: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
694: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
695: dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
696:
697: mech++; /* Move along to next candidate */
698:
699: return 1;
700: }
701:
1.130 markus 702: static OM_uint32
703: process_gssapi_token(void *ctxt, gss_buffer_t recv_tok)
704: {
1.260 ! markus 705: struct ssh *ssh = ctxt;
! 706: Authctxt *authctxt = ssh->authctxt;
1.130 markus 707: Gssctxt *gssctxt = authctxt->methoddata;
708: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 709: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
710: gss_buffer_desc gssbuf;
1.132 markus 711: OM_uint32 status, ms, flags;
712: Buffer b;
1.133 djm 713:
1.130 markus 714: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 715: recv_tok, &send_tok, &flags);
1.130 markus 716:
717: if (send_tok.length > 0) {
718: if (GSS_ERROR(status))
719: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
720: else
721: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 722:
1.130 markus 723: packet_put_string(send_tok.value, send_tok.length);
724: packet_send();
725: gss_release_buffer(&ms, &send_tok);
726: }
1.133 djm 727:
1.130 markus 728: if (status == GSS_S_COMPLETE) {
1.132 markus 729: /* send either complete or MIC, depending on mechanism */
730: if (!(flags & GSS_C_INTEG_FLAG)) {
731: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
732: packet_send();
733: } else {
734: ssh_gssapi_buildmic(&b, authctxt->server_user,
735: authctxt->service, "gssapi-with-mic");
736:
737: gssbuf.value = buffer_ptr(&b);
738: gssbuf.length = buffer_len(&b);
1.133 djm 739:
1.132 markus 740: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 741:
1.132 markus 742: if (!GSS_ERROR(status)) {
743: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
744: packet_put_string(mic.value, mic.length);
1.133 djm 745:
1.132 markus 746: packet_send();
747: }
1.133 djm 748:
1.132 markus 749: buffer_free(&b);
750: gss_release_buffer(&ms, &mic);
1.133 djm 751: }
1.130 markus 752: }
1.133 djm 753:
1.130 markus 754: return status;
755: }
756:
1.169 djm 757: /* ARGSUSED */
1.220 djm 758: int
1.121 markus 759: input_gssapi_response(int type, u_int32_t plen, void *ctxt)
760: {
1.260 ! markus 761: struct ssh *ssh = ctxt;
! 762: Authctxt *authctxt = ssh->authctxt;
1.121 markus 763: Gssctxt *gssctxt;
764: int oidlen;
765: char *oidv;
766:
767: if (authctxt == NULL)
768: fatal("input_gssapi_response: no authentication context");
769: gssctxt = authctxt->methoddata;
770:
771: /* Setup our OID */
772: oidv = packet_get_string(&oidlen);
773:
1.129 markus 774: if (oidlen <= 2 ||
775: oidv[0] != SSH_GSS_OIDTYPE ||
776: oidv[1] != oidlen - 2) {
1.197 djm 777: free(oidv);
1.129 markus 778: debug("Badly encoded mechanism OID received");
779: userauth(authctxt, NULL);
1.220 djm 780: return 0;
1.121 markus 781: }
1.129 markus 782:
783: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
784: fatal("Server returned different OID than expected");
1.121 markus 785:
786: packet_check_eom();
787:
1.197 djm 788: free(oidv);
1.121 markus 789:
1.130 markus 790: if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) {
1.121 markus 791: /* Start again with next method on list */
792: debug("Trying to start again");
793: userauth(authctxt, NULL);
1.220 djm 794: return 0;
1.121 markus 795: }
1.220 djm 796: return 0;
1.121 markus 797: }
798:
1.169 djm 799: /* ARGSUSED */
1.220 djm 800: int
1.121 markus 801: input_gssapi_token(int type, u_int32_t plen, void *ctxt)
802: {
1.260 ! markus 803: struct ssh *ssh = ctxt;
! 804: Authctxt *authctxt = ssh->authctxt;
1.121 markus 805: gss_buffer_desc recv_tok;
1.130 markus 806: OM_uint32 status;
1.121 markus 807: u_int slen;
808:
809: if (authctxt == NULL)
810: fatal("input_gssapi_response: no authentication context");
811:
812: recv_tok.value = packet_get_string(&slen);
813: recv_tok.length = slen; /* safe typecast */
814:
815: packet_check_eom();
816:
1.130 markus 817: status = process_gssapi_token(ctxt, &recv_tok);
1.121 markus 818:
1.197 djm 819: free(recv_tok.value);
1.121 markus 820:
821: if (GSS_ERROR(status)) {
822: /* Start again with the next method in the list */
823: userauth(authctxt, NULL);
1.220 djm 824: return 0;
1.121 markus 825: }
1.220 djm 826: return 0;
1.121 markus 827: }
828:
1.169 djm 829: /* ARGSUSED */
1.220 djm 830: int
1.121 markus 831: input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
832: {
1.260 ! markus 833: struct ssh *ssh = ctxt;
! 834: Authctxt *authctxt = ssh->authctxt;
1.121 markus 835: Gssctxt *gssctxt;
836: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
837: gss_buffer_desc recv_tok;
1.194 djm 838: OM_uint32 ms;
1.123 deraadt 839: u_int len;
1.121 markus 840:
841: if (authctxt == NULL)
842: fatal("input_gssapi_response: no authentication context");
843: gssctxt = authctxt->methoddata;
844:
1.123 deraadt 845: recv_tok.value = packet_get_string(&len);
846: recv_tok.length = len;
1.121 markus 847:
848: packet_check_eom();
849:
850: /* Stick it into GSSAPI and see what it says */
1.194 djm 851: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 852: &recv_tok, &send_tok, NULL);
1.121 markus 853:
1.197 djm 854: free(recv_tok.value);
1.121 markus 855: gss_release_buffer(&ms, &send_tok);
856:
857: /* Server will be returning a failed packet after this one */
1.220 djm 858: return 0;
1.121 markus 859: }
860:
1.169 djm 861: /* ARGSUSED */
1.220 djm 862: int
1.121 markus 863: input_gssapi_error(int type, u_int32_t plen, void *ctxt)
864: {
865: char *msg;
866: char *lang;
867:
1.194 djm 868: /* maj */(void)packet_get_int();
869: /* min */(void)packet_get_int();
1.121 markus 870: msg=packet_get_string(NULL);
871: lang=packet_get_string(NULL);
872:
873: packet_check_eom();
874:
1.143 stevesk 875: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 876: free(msg);
877: free(lang);
1.220 djm 878: return 0;
1.121 markus 879: }
880: #endif /* GSSAPI */
1.20 markus 881:
1.1 markus 882: int
1.23 markus 883: userauth_none(Authctxt *authctxt)
884: {
885: /* initial userauth request */
886: packet_start(SSH2_MSG_USERAUTH_REQUEST);
887: packet_put_cstring(authctxt->server_user);
888: packet_put_cstring(authctxt->service);
889: packet_put_cstring(authctxt->method->name);
890: packet_send();
891: return 1;
892: }
893:
894: int
1.20 markus 895: userauth_passwd(Authctxt *authctxt)
1.1 markus 896: {
1.6 markus 897: static int attempt = 0;
1.99 markus 898: char prompt[150];
1.1 markus 899: char *password;
1.175 dtucker 900: const char *host = options.host_key_alias ? options.host_key_alias :
901: authctxt->host;
1.6 markus 902:
1.13 todd 903: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 904: return 0;
1.13 todd 905:
1.87 deraadt 906: if (attempt != 1)
1.13 todd 907: error("Permission denied, please try again.");
1.1 markus 908:
1.43 itojun 909: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 910: authctxt->server_user, host);
1.1 markus 911: password = read_passphrase(prompt, 0);
912: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 913: packet_put_cstring(authctxt->server_user);
914: packet_put_cstring(authctxt->service);
1.23 markus 915: packet_put_cstring(authctxt->method->name);
1.1 markus 916: packet_put_char(0);
1.49 markus 917: packet_put_cstring(password);
1.204 djm 918: explicit_bzero(password, strlen(password));
1.197 djm 919: free(password);
1.85 markus 920: packet_add_padding(64);
1.1 markus 921: packet_send();
1.99 markus 922:
1.104 deraadt 923: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 924: &input_userauth_passwd_changereq);
925:
1.1 markus 926: return 1;
927: }
1.169 djm 928:
1.99 markus 929: /*
930: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
931: */
1.169 djm 932: /* ARGSUSED */
1.218 markus 933: int
1.153 djm 934: input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt)
1.99 markus 935: {
1.260 ! markus 936: struct ssh *ssh = ctxt;
! 937: Authctxt *authctxt = ssh->authctxt;
1.99 markus 938: char *info, *lang, *password = NULL, *retype = NULL;
939: char prompt[150];
1.252 djm 940: const char *host;
1.99 markus 941:
942: debug2("input_userauth_passwd_changereq");
943:
944: if (authctxt == NULL)
945: fatal("input_userauth_passwd_changereq: "
946: "no authentication context");
1.252 djm 947: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 948:
949: info = packet_get_string(NULL);
950: lang = packet_get_string(NULL);
951: if (strlen(info) > 0)
1.116 itojun 952: logit("%s", info);
1.197 djm 953: free(info);
954: free(lang);
1.99 markus 955: packet_start(SSH2_MSG_USERAUTH_REQUEST);
956: packet_put_cstring(authctxt->server_user);
957: packet_put_cstring(authctxt->service);
958: packet_put_cstring(authctxt->method->name);
959: packet_put_char(1); /* additional info */
1.104 deraadt 960: snprintf(prompt, sizeof(prompt),
1.99 markus 961: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 962: authctxt->server_user, host);
1.99 markus 963: password = read_passphrase(prompt, 0);
964: packet_put_cstring(password);
1.204 djm 965: explicit_bzero(password, strlen(password));
1.197 djm 966: free(password);
1.99 markus 967: password = NULL;
968: while (password == NULL) {
1.104 deraadt 969: snprintf(prompt, sizeof(prompt),
1.99 markus 970: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 971: authctxt->server_user, host);
1.99 markus 972: password = read_passphrase(prompt, RP_ALLOW_EOF);
973: if (password == NULL) {
974: /* bail out */
1.218 markus 975: return 0;
1.99 markus 976: }
1.104 deraadt 977: snprintf(prompt, sizeof(prompt),
1.99 markus 978: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 979: authctxt->server_user, host);
1.99 markus 980: retype = read_passphrase(prompt, 0);
981: if (strcmp(password, retype) != 0) {
1.204 djm 982: explicit_bzero(password, strlen(password));
1.197 djm 983: free(password);
1.116 itojun 984: logit("Mismatch; try again, EOF to quit.");
1.99 markus 985: password = NULL;
986: }
1.204 djm 987: explicit_bzero(retype, strlen(retype));
1.197 djm 988: free(retype);
1.99 markus 989: }
990: packet_put_cstring(password);
1.204 djm 991: explicit_bzero(password, strlen(password));
1.197 djm 992: free(password);
1.99 markus 993: packet_add_padding(64);
994: packet_send();
1.104 deraadt 995:
996: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 997: &input_userauth_passwd_changereq);
1.218 markus 998: return 0;
1.117 markus 999: }
1000:
1.231 markus 1001: static const char *
1.255 djm 1002: key_sign_encode(const struct sshkey *key)
1.231 markus 1003: {
1004: struct ssh *ssh = active_state;
1005:
1.255 djm 1006: if (key->type == KEY_RSA) {
1.231 markus 1007: switch (ssh->kex->rsa_sha2) {
1008: case 256:
1009: return "rsa-sha2-256";
1010: case 512:
1011: return "rsa-sha2-512";
1012: }
1013: }
1.255 djm 1014: return key_ssh_name(key);
1.231 markus 1015: }
1016:
1.117 markus 1017: static int
1.214 djm 1018: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1019: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1020: {
1.259 markus 1021: struct sshkey *prv;
1.117 markus 1022: int ret;
1.99 markus 1023:
1.117 markus 1024: /* the agent supports this key */
1.255 djm 1025: if (id->key != NULL && id->agent_fd != -1)
1.214 djm 1026: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.255 djm 1027: data, datalen, key_sign_encode(id->key), compat);
1.214 djm 1028:
1.117 markus 1029: /*
1030: * we have already loaded the private key or
1031: * the private key is stored in external hardware
1032: */
1.255 djm 1033: if (id->key != NULL &&
1034: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT)))
1035: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
1036: key_sign_encode(id->key), compat));
1037:
1.117 markus 1038: /* load the private key from the file */
1.229 jcs 1039: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1040: return SSH_ERR_KEY_NOT_FOUND;
1.255 djm 1041: ret = sshkey_sign(prv, sigp, lenp, data, datalen,
1042: key_sign_encode(prv), compat);
1.214 djm 1043: sshkey_free(prv);
1.117 markus 1044: return (ret);
1.51 markus 1045: }
1046:
1.76 itojun 1047: static int
1.255 djm 1048: id_filename_matches(Identity *id, Identity *private_id)
1049: {
1050: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1051: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1052: size_t i, slen;
1053:
1054: if (strcmp(id->filename, private_id->filename) == 0)
1055: return 1;
1056: for (i = 0; suffixes[i]; i++) {
1057: slen = strlen(suffixes[i]);
1058: if (len > slen && plen == len - slen &&
1059: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1060: memcmp(id->filename, private_id->filename, plen) == 0)
1061: return 1;
1062: }
1063: return 0;
1064: }
1065:
1066: static int
1.117 markus 1067: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1068: {
1069: Buffer b;
1.227 djm 1070: Identity *private_id;
1.32 markus 1071: u_char *blob, *signature;
1.214 djm 1072: size_t slen;
1.227 djm 1073: u_int bloblen, skip = 0;
1074: int matched, ret = -1, have_sig = 1;
1.182 djm 1075: char *fp;
1.1 markus 1076:
1.222 djm 1077: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1078: SSH_FP_DEFAULT)) == NULL)
1079: return 0;
1.227 djm 1080: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1081: free(fp);
1.51 markus 1082:
1.117 markus 1083: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1084: /* we cannot handle this key */
1.30 markus 1085: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1086: return 0;
1087: }
1.1 markus 1088: /* data to be signed */
1089: buffer_init(&b);
1.26 markus 1090: if (datafellows & SSH_OLD_SESSIONID) {
1091: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1092: skip = session_id2_len;
1.26 markus 1093: } else {
1.14 markus 1094: buffer_put_string(&b, session_id2, session_id2_len);
1095: skip = buffer_len(&b);
1096: }
1.1 markus 1097: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1098: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1099: buffer_put_cstring(&b,
1.30 markus 1100: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1101: "ssh-userauth" :
1.20 markus 1102: authctxt->service);
1.30 markus 1103: if (datafellows & SSH_BUG_PKAUTH) {
1104: buffer_put_char(&b, have_sig);
1105: } else {
1106: buffer_put_cstring(&b, authctxt->method->name);
1107: buffer_put_char(&b, have_sig);
1.255 djm 1108: buffer_put_cstring(&b, key_sign_encode(id->key));
1.30 markus 1109: }
1.1 markus 1110: buffer_put_string(&b, blob, bloblen);
1111:
1.227 djm 1112: /*
1113: * If the key is an certificate, try to find a matching private key
1114: * and use it to complete the signature.
1.241 djm 1115: * If no such private key exists, fall back to trying the certificate
1116: * key itself in case it has a private half already loaded.
1.227 djm 1117: */
1118: if (key_is_cert(id->key)) {
1119: matched = 0;
1120: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1121: if (sshkey_equal_public(id->key, private_id->key) &&
1122: id->key->type != private_id->key->type) {
1123: id = private_id;
1124: matched = 1;
1125: break;
1126: }
1127: }
1.255 djm 1128: /*
1129: * Exact key matches are preferred, but also allow
1130: * filename matches for non-PKCS#11/agent keys that
1131: * didn't load public keys. This supports the case
1132: * of keeping just a private key file and public
1133: * certificate on disk.
1134: */
1135: if (!matched && !id->isprivate && id->agent_fd == -1 &&
1136: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1137: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1138: if (private_id->key == NULL &&
1139: id_filename_matches(id, private_id)) {
1140: id = private_id;
1141: matched = 1;
1142: break;
1143: }
1144: }
1145: }
1.227 djm 1146: if (matched) {
1147: debug2("%s: using private key \"%s\"%s for "
1148: "certificate", __func__, id->filename,
1149: id->agent_fd != -1 ? " from agent" : "");
1150: } else {
1.240 djm 1151: debug("%s: no separate private key for certificate "
1.227 djm 1152: "\"%s\"", __func__, id->filename);
1153: }
1154: }
1155:
1.1 markus 1156: /* generate signature */
1.117 markus 1157: ret = identity_sign(id, &signature, &slen,
1.214 djm 1158: buffer_ptr(&b), buffer_len(&b), datafellows);
1159: if (ret != 0) {
1.239 djm 1160: if (ret != SSH_ERR_KEY_NOT_FOUND)
1161: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1162: free(blob);
1.17 markus 1163: buffer_free(&b);
1164: return 0;
1165: }
1.28 markus 1166: #ifdef DEBUG_PK
1.1 markus 1167: buffer_dump(&b);
1168: #endif
1.30 markus 1169: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1170: buffer_clear(&b);
1171: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1172: skip = session_id2_len;
1.10 markus 1173: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1174: buffer_put_cstring(&b, authctxt->server_user);
1175: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1176: buffer_put_cstring(&b, authctxt->method->name);
1177: buffer_put_char(&b, have_sig);
1.30 markus 1178: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1179: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1180: buffer_put_string(&b, blob, bloblen);
1181: }
1.197 djm 1182: free(blob);
1.51 markus 1183:
1.1 markus 1184: /* append signature */
1185: buffer_put_string(&b, signature, slen);
1.197 djm 1186: free(signature);
1.1 markus 1187:
1188: /* skip session id and packet type */
1.14 markus 1189: if (buffer_len(&b) < skip + 1)
1.20 markus 1190: fatal("userauth_pubkey: internal error");
1.14 markus 1191: buffer_consume(&b, skip + 1);
1.1 markus 1192:
1193: /* put remaining data from buffer into packet */
1194: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1195: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1196: buffer_free(&b);
1197: packet_send();
1.17 markus 1198:
1199: return 1;
1.16 markus 1200: }
1201:
1.76 itojun 1202: static int
1.117 markus 1203: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1204: {
1.51 markus 1205: u_char *blob;
1.97 markus 1206: u_int bloblen, have_sig = 0;
1.20 markus 1207:
1.51 markus 1208: debug3("send_pubkey_test");
1.16 markus 1209:
1.117 markus 1210: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1211: /* we cannot handle this key */
1212: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1213: return 0;
1214: }
1.51 markus 1215: /* register callback for USERAUTH_PK_OK message */
1216: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1217:
1218: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1219: packet_put_cstring(authctxt->server_user);
1220: packet_put_cstring(authctxt->service);
1221: packet_put_cstring(authctxt->method->name);
1222: packet_put_char(have_sig);
1223: if (!(datafellows & SSH_BUG_PKAUTH))
1.255 djm 1224: packet_put_cstring(key_sign_encode(id->key));
1.51 markus 1225: packet_put_string(blob, bloblen);
1.197 djm 1226: free(blob);
1.51 markus 1227: packet_send();
1228: return 1;
1229: }
1230:
1.259 markus 1231: static struct sshkey *
1.229 jcs 1232: load_identity_file(Identity *id)
1.51 markus 1233: {
1.259 markus 1234: struct sshkey *private = NULL;
1.229 jcs 1235: char prompt[300], *passphrase, *comment;
1.215 djm 1236: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1237: struct stat st;
1.16 markus 1238:
1.229 jcs 1239: if (stat(id->filename, &st) < 0) {
1240: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1241: id->filename, strerror(errno));
1.52 markus 1242: return NULL;
1243: }
1.214 djm 1244: snprintf(prompt, sizeof prompt,
1.229 jcs 1245: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1246: for (i = 0; i <= options.number_of_password_prompts; i++) {
1247: if (i == 0)
1248: passphrase = "";
1249: else {
1.20 markus 1250: passphrase = read_passphrase(prompt, 0);
1.214 djm 1251: if (*passphrase == '\0') {
1.20 markus 1252: debug2("no passphrase given, try next key");
1.214 djm 1253: free(passphrase);
1254: break;
1255: }
1256: }
1.229 jcs 1257: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1258: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1259: case 0:
1260: break;
1261: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1262: if (options.batch_mode) {
1263: quit = 1;
1264: break;
1265: }
1.215 djm 1266: if (i != 0)
1267: debug2("bad passphrase given, try again...");
1.214 djm 1268: break;
1269: case SSH_ERR_SYSTEM_ERROR:
1270: if (errno == ENOENT) {
1271: debug2("Load key \"%s\": %s",
1.229 jcs 1272: id->filename, ssh_err(r));
1.51 markus 1273: quit = 1;
1.214 djm 1274: break;
1.20 markus 1275: }
1.214 djm 1276: /* FALLTHROUGH */
1277: default:
1.229 jcs 1278: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1279: quit = 1;
1280: break;
1281: }
1.230 djm 1282: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1283: !(id->key && id->isprivate))
1284: maybe_add_key_to_agent(id->filename, private, comment,
1285: passphrase);
1.214 djm 1286: if (i > 0) {
1.204 djm 1287: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1288: free(passphrase);
1.16 markus 1289: }
1.232 mmcc 1290: free(comment);
1.214 djm 1291: if (private != NULL || quit)
1292: break;
1.16 markus 1293: }
1.51 markus 1294: return private;
1295: }
1296:
1.117 markus 1297: /*
1298: * try keys in the following order:
1.227 djm 1299: * 1. certificates listed in the config file
1300: * 2. other input certificates
1301: * 3. agent keys that are found in the config file
1302: * 4. other agent keys
1303: * 5. keys that are only listed in the config file
1.117 markus 1304: */
1305: static void
1306: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1307: {
1.214 djm 1308: struct identity *id, *id2, *tmp;
1309: struct idlist agent, files, *preferred;
1310: struct sshkey *key;
1.230 djm 1311: int agent_fd = -1, i, r, found;
1.214 djm 1312: size_t j;
1313: struct ssh_identitylist *idlist;
1.51 markus 1314:
1.117 markus 1315: TAILQ_INIT(&agent); /* keys from the agent */
1316: TAILQ_INIT(&files); /* keys from the config file */
1317: preferred = &authctxt->keys;
1318: TAILQ_INIT(preferred); /* preferred order of keys */
1319:
1.190 djm 1320: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1321: for (i = 0; i < options.num_identity_files; i++) {
1322: key = options.identity_keys[i];
1.180 djm 1323: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1324: continue;
1325: options.identity_keys[i] = NULL;
1.150 djm 1326: id = xcalloc(1, sizeof(*id));
1.230 djm 1327: id->agent_fd = -1;
1.117 markus 1328: id->key = key;
1329: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1330: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1331: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1332: }
1.227 djm 1333: /* list of certificates specified by user */
1334: for (i = 0; i < options.num_certificate_files; i++) {
1335: key = options.certificates[i];
1336: if (!key_is_cert(key) || key->cert == NULL ||
1337: key->cert->type != SSH2_CERT_TYPE_USER)
1338: continue;
1339: id = xcalloc(1, sizeof(*id));
1.230 djm 1340: id->agent_fd = -1;
1.227 djm 1341: id->key = key;
1342: id->filename = xstrdup(options.certificate_files[i]);
1343: id->userprovided = options.certificate_file_userprovided[i];
1344: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1345: }
1346: /* list of keys supported by the agent */
1.214 djm 1347: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1348: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1349: debug("%s: ssh_get_authentication_socket: %s",
1350: __func__, ssh_err(r));
1.258 naddy 1351: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1352: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1353: debug("%s: ssh_fetch_identitylist: %s",
1354: __func__, ssh_err(r));
1.237 markus 1355: close(agent_fd);
1.214 djm 1356: } else {
1357: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1358: found = 0;
1359: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1360: /*
1361: * agent keys from the config file are
1362: * preferred
1363: */
1364: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1365: TAILQ_REMOVE(&files, id, next);
1366: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1367: id->agent_fd = agent_fd;
1.117 markus 1368: found = 1;
1369: break;
1370: }
1371: }
1.135 markus 1372: if (!found && !options.identities_only) {
1.150 djm 1373: id = xcalloc(1, sizeof(*id));
1.214 djm 1374: /* XXX "steals" key/comment from idlist */
1375: id->key = idlist->keys[j];
1376: id->filename = idlist->comments[j];
1377: idlist->keys[j] = NULL;
1378: idlist->comments[j] = NULL;
1379: id->agent_fd = agent_fd;
1.117 markus 1380: TAILQ_INSERT_TAIL(&agent, id, next);
1381: }
1382: }
1.214 djm 1383: ssh_free_identitylist(idlist);
1.117 markus 1384: /* append remaining agent keys */
1385: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1386: TAILQ_REMOVE(&agent, id, next);
1387: TAILQ_INSERT_TAIL(preferred, id, next);
1388: }
1.214 djm 1389: authctxt->agent_fd = agent_fd;
1.244 djm 1390: }
1391: /* Prefer PKCS11 keys that are explicitly listed */
1392: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1393: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1394: continue;
1395: found = 0;
1396: TAILQ_FOREACH(id2, &files, next) {
1397: if (id2->key == NULL ||
1398: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1399: continue;
1400: if (sshkey_equal(id->key, id2->key)) {
1401: TAILQ_REMOVE(&files, id, next);
1402: TAILQ_INSERT_TAIL(preferred, id, next);
1403: found = 1;
1404: break;
1405: }
1406: }
1407: /* If IdentitiesOnly set and key not found then don't use it */
1408: if (!found && options.identities_only) {
1409: TAILQ_REMOVE(&files, id, next);
1410: explicit_bzero(id, sizeof(*id));
1411: free(id);
1412: }
1.117 markus 1413: }
1414: /* append remaining keys from the config file */
1415: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1416: TAILQ_REMOVE(&files, id, next);
1417: TAILQ_INSERT_TAIL(preferred, id, next);
1418: }
1.228 djm 1419: /* finally, filter by PubkeyAcceptedKeyTypes */
1420: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1421: if (id->key != NULL &&
1422: match_pattern_list(sshkey_ssh_name(id->key),
1423: options.pubkey_key_types, 0) != 1) {
1424: debug("Skipping %s key %s - "
1425: "not in PubkeyAcceptedKeyTypes",
1426: sshkey_ssh_name(id->key), id->filename);
1427: TAILQ_REMOVE(preferred, id, next);
1428: sshkey_free(id->key);
1429: free(id->filename);
1430: memset(id, 0, sizeof(*id));
1431: continue;
1432: }
1.230 djm 1433: debug2("key: %s (%p)%s%s", id->filename, id->key,
1434: id->userprovided ? ", explicit" : "",
1435: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1436: }
1.17 markus 1437: }
1438:
1.117 markus 1439: static void
1440: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1441: {
1.117 markus 1442: Identity *id;
1.51 markus 1443:
1.214 djm 1444: if (authctxt->agent_fd != -1)
1445: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1446: for (id = TAILQ_FIRST(&authctxt->keys); id;
1447: id = TAILQ_FIRST(&authctxt->keys)) {
1448: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1449: sshkey_free(id->key);
1.197 djm 1450: free(id->filename);
1451: free(id);
1.117 markus 1452: }
1.1 markus 1453: }
1454:
1.251 djm 1455: static void
1456: pubkey_reset(Authctxt *authctxt)
1457: {
1458: Identity *id;
1459:
1460: TAILQ_FOREACH(id, &authctxt->keys, next)
1461: id->tried = 0;
1462: }
1463:
1.225 markus 1464: static int
1465: try_identity(Identity *id)
1466: {
1467: if (!id->key)
1468: return (0);
1469: if (key_type_plain(id->key->type) == KEY_RSA &&
1470: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1471: debug("Skipped %s key %s for RSA/MD5 server",
1472: key_type(id->key), id->filename);
1473: return (0);
1474: }
1.257 djm 1475: return 1;
1.225 markus 1476: }
1477:
1.20 markus 1478: int
1479: userauth_pubkey(Authctxt *authctxt)
1480: {
1.117 markus 1481: Identity *id;
1.20 markus 1482: int sent = 0;
1.256 djm 1483: char *fp;
1.20 markus 1484:
1.117 markus 1485: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1486: if (id->tried++)
1487: return (0);
1.127 markus 1488: /* move key to the end of the queue */
1.117 markus 1489: TAILQ_REMOVE(&authctxt->keys, id, next);
1490: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1491: /*
1492: * send a test message if we have the public key. for
1493: * encrypted keys we cannot do this and have to load the
1494: * private key instead
1495: */
1.200 djm 1496: if (id->key != NULL) {
1.225 markus 1497: if (try_identity(id)) {
1.256 djm 1498: if ((fp = sshkey_fingerprint(id->key,
1499: options.fingerprint_hash,
1500: SSH_FP_DEFAULT)) == NULL) {
1501: error("%s: sshkey_fingerprint failed",
1502: __func__);
1503: return 0;
1504: }
1505: debug("Offering public key: %s %s %s",
1506: sshkey_type(id->key), fp, id->filename);
1507: free(fp);
1.200 djm 1508: sent = send_pubkey_test(authctxt, id);
1509: }
1510: } else {
1.117 markus 1511: debug("Trying private key: %s", id->filename);
1.229 jcs 1512: id->key = load_identity_file(id);
1.117 markus 1513: if (id->key != NULL) {
1.225 markus 1514: if (try_identity(id)) {
1515: id->isprivate = 1;
1.200 djm 1516: sent = sign_and_send_pubkey(
1517: authctxt, id);
1518: }
1.117 markus 1519: key_free(id->key);
1520: id->key = NULL;
1.251 djm 1521: id->isprivate = 0;
1.51 markus 1522: }
1523: }
1.117 markus 1524: if (sent)
1525: return (sent);
1.28 markus 1526: }
1.117 markus 1527: return (0);
1.20 markus 1528: }
1529:
1.23 markus 1530: /*
1531: * Send userauth request message specifying keyboard-interactive method.
1532: */
1533: int
1534: userauth_kbdint(Authctxt *authctxt)
1535: {
1536: static int attempt = 0;
1537:
1538: if (attempt++ >= options.number_of_password_prompts)
1539: return 0;
1.82 markus 1540: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1541: if (attempt > 1 && !authctxt->info_req_seen) {
1542: debug3("userauth_kbdint: disable: no info_req_seen");
1543: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1544: return 0;
1545: }
1.23 markus 1546:
1547: debug2("userauth_kbdint");
1548: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1549: packet_put_cstring(authctxt->server_user);
1550: packet_put_cstring(authctxt->service);
1551: packet_put_cstring(authctxt->method->name);
1552: packet_put_cstring(""); /* lang */
1553: packet_put_cstring(options.kbd_interactive_devices ?
1554: options.kbd_interactive_devices : "");
1555: packet_send();
1556:
1557: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1558: return 1;
1559: }
1560:
1561: /*
1.46 markus 1562: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1563: */
1.218 markus 1564: int
1.92 markus 1565: input_userauth_info_req(int type, u_int32_t seq, void *ctxt)
1.23 markus 1566: {
1.260 ! markus 1567: struct ssh *ssh = ctxt;
! 1568: Authctxt *authctxt = ssh->authctxt;
1.46 markus 1569: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1570: u_int num_prompts, i;
1.23 markus 1571: int echo = 0;
1572:
1573: debug2("input_userauth_info_req");
1574:
1575: if (authctxt == NULL)
1576: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1577:
1578: authctxt->info_req_seen = 1;
1.23 markus 1579:
1580: name = packet_get_string(NULL);
1581: inst = packet_get_string(NULL);
1582: lang = packet_get_string(NULL);
1583: if (strlen(name) > 0)
1.116 itojun 1584: logit("%s", name);
1.23 markus 1585: if (strlen(inst) > 0)
1.116 itojun 1586: logit("%s", inst);
1.197 djm 1587: free(name);
1588: free(inst);
1589: free(lang);
1.23 markus 1590:
1591: num_prompts = packet_get_int();
1592: /*
1593: * Begin to build info response packet based on prompts requested.
1594: * We commit to providing the correct number of responses, so if
1595: * further on we run into a problem that prevents this, we have to
1596: * be sure and clean this up and send a correct error response.
1597: */
1598: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1599: packet_put_int(num_prompts);
1600:
1.73 markus 1601: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1602: for (i = 0; i < num_prompts; i++) {
1603: prompt = packet_get_string(NULL);
1604: echo = packet_get_char();
1605:
1.77 markus 1606: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1607:
1.49 markus 1608: packet_put_cstring(response);
1.204 djm 1609: explicit_bzero(response, strlen(response));
1.197 djm 1610: free(response);
1611: free(prompt);
1.23 markus 1612: }
1.90 markus 1613: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1614:
1.85 markus 1615: packet_add_padding(64);
1.23 markus 1616: packet_send();
1.218 markus 1617: return 0;
1.68 markus 1618: }
1619:
1.100 markus 1620: static int
1.223 djm 1621: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1622: const u_char *data, size_t datalen)
1.100 markus 1623: {
1.223 djm 1624: struct sshbuf *b;
1.101 markus 1625: struct stat st;
1.100 markus 1626: pid_t pid;
1.223 djm 1627: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1628: u_char rversion = 0, version = 2;
1629: void (*osigchld)(int);
1.100 markus 1630:
1.223 djm 1631: *sigp = NULL;
1632: *lenp = 0;
1.100 markus 1633:
1.101 markus 1634: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1635: error("%s: not installed: %s", __func__, strerror(errno));
1636: return -1;
1637: }
1638: if (fflush(stdout) != 0) {
1639: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1640: return -1;
1641: }
1.100 markus 1642: if (pipe(to) < 0) {
1.223 djm 1643: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1644: return -1;
1645: }
1646: if (pipe(from) < 0) {
1.223 djm 1647: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1648: return -1;
1649: }
1650: if ((pid = fork()) < 0) {
1.223 djm 1651: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1652: return -1;
1653: }
1.223 djm 1654: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1655: if (pid == 0) {
1.174 dtucker 1656: /* keep the socket on exec */
1.223 djm 1657: fcntl(sock, F_SETFD, 0);
1.155 markus 1658: permanently_drop_suid(getuid());
1.100 markus 1659: close(from[0]);
1660: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1661: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1662: close(to[1]);
1663: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1664: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1665: close(from[1]);
1666: close(to[0]);
1.223 djm 1667: /* Close everything but stdio and the socket */
1668: for (i = STDERR_FILENO + 1; i < sock; i++)
1669: close(i);
1670: closefrom(sock + 1);
1671: debug3("%s: [child] pid=%ld, exec %s",
1672: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1673: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1674: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1675: strerror(errno));
1676: }
1677: close(from[1]);
1678: close(to[0]);
1679:
1.223 djm 1680: if ((b = sshbuf_new()) == NULL)
1681: fatal("%s: sshbuf_new failed", __func__);
1682: /* send # of sock, data to be signed */
1.253 djm 1683: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 1684: (r = sshbuf_put_string(b, data, datalen)) != 0)
1685: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1686: if (ssh_msg_send(to[1], version, b) == -1)
1687: fatal("%s: couldn't send request", __func__);
1688: sshbuf_reset(b);
1689: r = ssh_msg_recv(from[0], b);
1.101 markus 1690: close(from[0]);
1691: close(to[1]);
1.223 djm 1692: if (r < 0) {
1693: error("%s: no reply", __func__);
1694: goto fail;
1695: }
1.101 markus 1696:
1.223 djm 1697: errno = 0;
1698: while (waitpid(pid, &status, 0) < 0) {
1699: if (errno != EINTR) {
1700: error("%s: waitpid %ld: %s",
1701: __func__, (long)pid, strerror(errno));
1702: goto fail;
1703: }
1704: }
1705: if (!WIFEXITED(status)) {
1706: error("%s: exited abnormally", __func__);
1707: goto fail;
1708: }
1709: if (WEXITSTATUS(status) != 0) {
1710: error("%s: exited with status %d",
1711: __func__, WEXITSTATUS(status));
1712: goto fail;
1713: }
1714: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1715: error("%s: buffer error: %s", __func__, ssh_err(r));
1716: goto fail;
1717: }
1718: if (rversion != version) {
1719: error("%s: bad version", __func__);
1720: goto fail;
1721: }
1722: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1723: error("%s: buffer error: %s", __func__, ssh_err(r));
1724: fail:
1725: signal(SIGCHLD, osigchld);
1726: sshbuf_free(b);
1.100 markus 1727: return -1;
1728: }
1.223 djm 1729: signal(SIGCHLD, osigchld);
1730: sshbuf_free(b);
1.100 markus 1731:
1732: return 0;
1733: }
1734:
1.68 markus 1735: int
1736: userauth_hostbased(Authctxt *authctxt)
1737: {
1.223 djm 1738: struct ssh *ssh = active_state;
1739: struct sshkey *private = NULL;
1740: struct sshbuf *b = NULL;
1.72 markus 1741: const char *service;
1.223 djm 1742: u_char *sig = NULL, *keyblob = NULL;
1743: char *fp = NULL, *chost = NULL, *lname = NULL;
1744: size_t siglen = 0, keylen = 0;
1745: int i, r, success = 0;
1746:
1747: if (authctxt->ktypes == NULL) {
1748: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1749: authctxt->ktypes = authctxt->oktypes;
1750: }
1.213 djm 1751:
1.223 djm 1752: /*
1753: * Work through each listed type pattern in HostbasedKeyTypes,
1754: * trying each hostkey that matches the type in turn.
1755: */
1756: for (;;) {
1757: if (authctxt->active_ktype == NULL)
1758: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1759: if (authctxt->active_ktype == NULL ||
1760: *authctxt->active_ktype == '\0')
1761: break;
1762: debug3("%s: trying key type %s", __func__,
1763: authctxt->active_ktype);
1.68 markus 1764:
1.223 djm 1765: /* check for a useful key */
1766: private = NULL;
1767: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1768: if (authctxt->sensitive->keys[i] == NULL ||
1769: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1770: continue;
1771: if (match_pattern_list(
1772: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1773: authctxt->active_ktype, 0) != 1)
1.223 djm 1774: continue;
1.68 markus 1775: /* we take and free the key */
1.223 djm 1776: private = authctxt->sensitive->keys[i];
1777: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1778: break;
1779: }
1.223 djm 1780: /* Found one */
1781: if (private != NULL)
1782: break;
1783: /* No more keys of this type; advance */
1784: authctxt->active_ktype = NULL;
1.68 markus 1785: }
1.223 djm 1786: if (private == NULL) {
1787: free(authctxt->oktypes);
1788: authctxt->oktypes = authctxt->ktypes = NULL;
1789: authctxt->active_ktype = NULL;
1.109 markus 1790: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1791: goto out;
1.68 markus 1792: }
1.211 djm 1793:
1.223 djm 1794: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1795: SSH_FP_DEFAULT)) == NULL) {
1796: error("%s: sshkey_fingerprint failed", __func__);
1797: goto out;
1.68 markus 1798: }
1.223 djm 1799: debug("%s: trying hostkey %s %s",
1800: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1801:
1.84 markus 1802: /* figure out a name for the client host */
1.223 djm 1803: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1804: error("%s: cannot get local ipaddr/name", __func__);
1805: goto out;
1.84 markus 1806: }
1.223 djm 1807:
1808: /* XXX sshbuf_put_stringf? */
1809: xasprintf(&chost, "%s.", lname);
1810: debug2("%s: chost %s", __func__, chost);
1.84 markus 1811:
1.72 markus 1812: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1813: authctxt->service;
1.223 djm 1814:
1.68 markus 1815: /* construct data */
1.223 djm 1816: if ((b = sshbuf_new()) == NULL) {
1817: error("%s: sshbuf_new failed", __func__);
1818: goto out;
1819: }
1820: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1821: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1822: goto out;
1823: }
1824: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1825: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1826: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1827: (r = sshbuf_put_cstring(b, service)) != 0 ||
1828: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1829: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1830: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1831: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1832: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1833: error("%s: buffer error: %s", __func__, ssh_err(r));
1834: goto out;
1835: }
1836:
1.68 markus 1837: #ifdef DEBUG_PK
1.223 djm 1838: sshbuf_dump(b, stderr);
1.68 markus 1839: #endif
1.223 djm 1840: if (authctxt->sensitive->external_keysign)
1841: r = ssh_keysign(private, &sig, &siglen,
1842: sshbuf_ptr(b), sshbuf_len(b));
1843: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1844: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1845: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1846: if (r != 0) {
1847: error("sign using hostkey %s %s failed",
1848: sshkey_ssh_name(private), fp);
1849: goto out;
1850: }
1851: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1852: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1853: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1854: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1855: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1856: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1857: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1858: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1859: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1860: (r = sshpkt_send(ssh)) != 0) {
1861: error("%s: packet error: %s", __func__, ssh_err(r));
1862: goto out;
1863: }
1864: success = 1;
1865:
1866: out:
1867: if (sig != NULL) {
1868: explicit_bzero(sig, siglen);
1869: free(sig);
1.68 markus 1870: }
1.223 djm 1871: free(keyblob);
1872: free(lname);
1873: free(fp);
1.197 djm 1874: free(chost);
1.223 djm 1875: sshkey_free(private);
1876: sshbuf_free(b);
1.68 markus 1877:
1.223 djm 1878: return success;
1.23 markus 1879: }
1.170 djm 1880:
1.20 markus 1881: /* find auth method */
1882:
1883: /*
1884: * given auth method name, if configurable options permit this method fill
1885: * in auth_ident field and return true, otherwise return false.
1886: */
1.76 itojun 1887: static int
1.20 markus 1888: authmethod_is_enabled(Authmethod *method)
1889: {
1890: if (method == NULL)
1891: return 0;
1892: /* return false if options indicate this method is disabled */
1893: if (method->enabled == NULL || *method->enabled == 0)
1894: return 0;
1895: /* return false if batch mode is enabled but method needs interactive mode */
1896: if (method->batch_flag != NULL && *method->batch_flag != 0)
1897: return 0;
1898: return 1;
1899: }
1900:
1.76 itojun 1901: static Authmethod *
1.20 markus 1902: authmethod_lookup(const char *name)
1.1 markus 1903: {
1.20 markus 1904: Authmethod *method = NULL;
1905: if (name != NULL)
1906: for (method = authmethods; method->name != NULL; method++)
1907: if (strcmp(name, method->name) == 0)
1908: return method;
1909: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1910: return NULL;
1911: }
1.1 markus 1912:
1.53 markus 1913: /* XXX internal state */
1914: static Authmethod *current = NULL;
1915: static char *supported = NULL;
1916: static char *preferred = NULL;
1.105 deraadt 1917:
1.20 markus 1918: /*
1919: * Given the authentication method list sent by the server, return the
1920: * next method we should try. If the server initially sends a nil list,
1.67 markus 1921: * use a built-in default list.
1.41 stevesk 1922: */
1.76 itojun 1923: static Authmethod *
1.20 markus 1924: authmethod_get(char *authlist)
1925: {
1.53 markus 1926: char *name = NULL;
1.97 markus 1927: u_int next;
1.41 stevesk 1928:
1.20 markus 1929: /* Use a suitable default if we're passed a nil list. */
1930: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1931: authlist = options.preferred_authentications;
1.20 markus 1932:
1.53 markus 1933: if (supported == NULL || strcmp(authlist, supported) != 0) {
1934: debug3("start over, passed a different list %s", authlist);
1.197 djm 1935: free(supported);
1.53 markus 1936: supported = xstrdup(authlist);
1937: preferred = options.preferred_authentications;
1938: debug3("preferred %s", preferred);
1939: current = NULL;
1940: } else if (current != NULL && authmethod_is_enabled(current))
1941: return current;
1.20 markus 1942:
1.53 markus 1943: for (;;) {
1944: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1945: debug("No more authentication methods to try.");
1.53 markus 1946: current = NULL;
1947: return NULL;
1948: }
1949: preferred += next;
1.23 markus 1950: debug3("authmethod_lookup %s", name);
1.53 markus 1951: debug3("remaining preferred: %s", preferred);
1952: if ((current = authmethod_lookup(name)) != NULL &&
1953: authmethod_is_enabled(current)) {
1.23 markus 1954: debug3("authmethod_is_enabled %s", name);
1.109 markus 1955: debug("Next authentication method: %s", name);
1.197 djm 1956: free(name);
1.53 markus 1957: return current;
1.23 markus 1958: }
1.198 dtucker 1959: free(name);
1.1 markus 1960: }
1.53 markus 1961: }
1.1 markus 1962:
1.79 stevesk 1963: static char *
1.53 markus 1964: authmethods_get(void)
1965: {
1966: Authmethod *method = NULL;
1.93 markus 1967: Buffer b;
1968: char *list;
1.27 provos 1969:
1.93 markus 1970: buffer_init(&b);
1.53 markus 1971: for (method = authmethods; method->name != NULL; method++) {
1972: if (authmethod_is_enabled(method)) {
1.93 markus 1973: if (buffer_len(&b) > 0)
1974: buffer_append(&b, ",", 1);
1975: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1976: }
1977: }
1.242 djm 1978: if ((list = sshbuf_dup_string(&b)) == NULL)
1979: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1980: buffer_free(&b);
1981: return list;
1.1 markus 1982: }
1.170 djm 1983:
![[BACK]](/icons/back.gif){kind=icon}
Return to sshconnect2.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh