Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.263
1.263 ! markus 1: /* $OpenBSD: sshconnect2.c,v 1.262 2017/05/31 05:08:46 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
1.170 djm 4: * Copyright (c) 2008 Damien Miller. All rights reserved.
1.1 markus 5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.145 stevesk 27: #include <sys/types.h>
1.160 deraadt 28: #include <sys/socket.h>
1.145 stevesk 29: #include <sys/wait.h>
1.144 stevesk 30: #include <sys/queue.h>
1.146 stevesk 31: #include <sys/stat.h>
1.156 stevesk 32:
33: #include <errno.h>
1.174 dtucker 34: #include <fcntl.h>
1.164 jolan 35: #include <netdb.h>
1.159 stevesk 36: #include <stdio.h>
1.158 stevesk 37: #include <string.h>
1.160 deraadt 38: #include <signal.h>
39: #include <pwd.h>
1.157 stevesk 40: #include <unistd.h>
1.166 djm 41: #include <vis.h>
1.1 markus 42:
1.160 deraadt 43: #include "xmalloc.h"
1.1 markus 44: #include "ssh.h"
1.37 markus 45: #include "ssh2.h"
1.1 markus 46: #include "buffer.h"
47: #include "packet.h"
48: #include "compat.h"
1.37 markus 49: #include "cipher.h"
1.160 deraadt 50: #include "key.h"
1.1 markus 51: #include "kex.h"
52: #include "myproposal.h"
53: #include "sshconnect.h"
54: #include "authfile.h"
1.57 provos 55: #include "dh.h"
1.17 markus 56: #include "authfd.h"
1.37 markus 57: #include "log.h"
1.210 millert 58: #include "misc.h"
1.37 markus 59: #include "readconf.h"
1.53 markus 60: #include "match.h"
1.61 markus 61: #include "dispatch.h"
1.68 markus 62: #include "canohost.h"
1.100 markus 63: #include "msg.h"
64: #include "pathnames.h"
1.154 markus 65: #include "uidswap.h"
1.186 djm 66: #include "hostfile.h"
1.214 djm 67: #include "ssherr.h"
1.246 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:
1.263 ! markus 212: ssh_dispatch_run_fatal(active_state, DISPATCH_BLOCK, &kex->done);
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);
1.263 ! markus 396: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.260 markus 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
1.262 djm 698: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 699: {
1.260 markus 700: Authctxt *authctxt = ssh->authctxt;
1.130 markus 701: Gssctxt *gssctxt = authctxt->methoddata;
702: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 703: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
704: gss_buffer_desc gssbuf;
1.132 markus 705: OM_uint32 status, ms, flags;
706: Buffer b;
1.133 djm 707:
1.130 markus 708: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 709: recv_tok, &send_tok, &flags);
1.130 markus 710:
711: if (send_tok.length > 0) {
712: if (GSS_ERROR(status))
713: packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
714: else
715: packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
1.133 djm 716:
1.130 markus 717: packet_put_string(send_tok.value, send_tok.length);
718: packet_send();
719: gss_release_buffer(&ms, &send_tok);
720: }
1.133 djm 721:
1.130 markus 722: if (status == GSS_S_COMPLETE) {
1.132 markus 723: /* send either complete or MIC, depending on mechanism */
724: if (!(flags & GSS_C_INTEG_FLAG)) {
725: packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE);
726: packet_send();
727: } else {
728: ssh_gssapi_buildmic(&b, authctxt->server_user,
729: authctxt->service, "gssapi-with-mic");
730:
731: gssbuf.value = buffer_ptr(&b);
732: gssbuf.length = buffer_len(&b);
1.133 djm 733:
1.132 markus 734: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 735:
1.132 markus 736: if (!GSS_ERROR(status)) {
737: packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC);
738: packet_put_string(mic.value, mic.length);
1.133 djm 739:
1.132 markus 740: packet_send();
741: }
1.133 djm 742:
1.132 markus 743: buffer_free(&b);
744: gss_release_buffer(&ms, &mic);
1.133 djm 745: }
1.130 markus 746: }
1.133 djm 747:
1.130 markus 748: return status;
749: }
750:
1.169 djm 751: /* ARGSUSED */
1.220 djm 752: int
1.261 markus 753: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 754: {
1.260 markus 755: Authctxt *authctxt = ssh->authctxt;
1.121 markus 756: Gssctxt *gssctxt;
757: int oidlen;
758: char *oidv;
759:
760: if (authctxt == NULL)
761: fatal("input_gssapi_response: no authentication context");
762: gssctxt = authctxt->methoddata;
763:
764: /* Setup our OID */
765: oidv = packet_get_string(&oidlen);
766:
1.129 markus 767: if (oidlen <= 2 ||
768: oidv[0] != SSH_GSS_OIDTYPE ||
769: oidv[1] != oidlen - 2) {
1.197 djm 770: free(oidv);
1.129 markus 771: debug("Badly encoded mechanism OID received");
772: userauth(authctxt, NULL);
1.220 djm 773: return 0;
1.121 markus 774: }
1.129 markus 775:
776: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
777: fatal("Server returned different OID than expected");
1.121 markus 778:
779: packet_check_eom();
780:
1.197 djm 781: free(oidv);
1.121 markus 782:
1.262 djm 783: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 784: /* Start again with next method on list */
785: debug("Trying to start again");
786: userauth(authctxt, NULL);
1.220 djm 787: return 0;
1.121 markus 788: }
1.220 djm 789: return 0;
1.121 markus 790: }
791:
1.169 djm 792: /* ARGSUSED */
1.220 djm 793: int
1.261 markus 794: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 795: {
1.260 markus 796: Authctxt *authctxt = ssh->authctxt;
1.121 markus 797: gss_buffer_desc recv_tok;
1.130 markus 798: OM_uint32 status;
1.121 markus 799: u_int slen;
800:
801: if (authctxt == NULL)
802: fatal("input_gssapi_response: no authentication context");
803:
804: recv_tok.value = packet_get_string(&slen);
805: recv_tok.length = slen; /* safe typecast */
806:
807: packet_check_eom();
808:
1.262 djm 809: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 810:
1.197 djm 811: free(recv_tok.value);
1.121 markus 812:
813: if (GSS_ERROR(status)) {
814: /* Start again with the next method in the list */
815: userauth(authctxt, NULL);
1.220 djm 816: return 0;
1.121 markus 817: }
1.220 djm 818: return 0;
1.121 markus 819: }
820:
1.169 djm 821: /* ARGSUSED */
1.220 djm 822: int
1.261 markus 823: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 824: {
1.260 markus 825: Authctxt *authctxt = ssh->authctxt;
1.121 markus 826: Gssctxt *gssctxt;
827: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
828: gss_buffer_desc recv_tok;
1.194 djm 829: OM_uint32 ms;
1.123 deraadt 830: u_int len;
1.121 markus 831:
832: if (authctxt == NULL)
833: fatal("input_gssapi_response: no authentication context");
834: gssctxt = authctxt->methoddata;
835:
1.123 deraadt 836: recv_tok.value = packet_get_string(&len);
837: recv_tok.length = len;
1.121 markus 838:
839: packet_check_eom();
840:
841: /* Stick it into GSSAPI and see what it says */
1.194 djm 842: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 843: &recv_tok, &send_tok, NULL);
1.121 markus 844:
1.197 djm 845: free(recv_tok.value);
1.121 markus 846: gss_release_buffer(&ms, &send_tok);
847:
848: /* Server will be returning a failed packet after this one */
1.220 djm 849: return 0;
1.121 markus 850: }
851:
1.169 djm 852: /* ARGSUSED */
1.220 djm 853: int
1.261 markus 854: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 855: {
856: char *msg;
857: char *lang;
858:
1.194 djm 859: /* maj */(void)packet_get_int();
860: /* min */(void)packet_get_int();
1.121 markus 861: msg=packet_get_string(NULL);
862: lang=packet_get_string(NULL);
863:
864: packet_check_eom();
865:
1.143 stevesk 866: debug("Server GSSAPI Error:\n%s", msg);
1.197 djm 867: free(msg);
868: free(lang);
1.220 djm 869: return 0;
1.121 markus 870: }
871: #endif /* GSSAPI */
1.20 markus 872:
1.1 markus 873: int
1.23 markus 874: userauth_none(Authctxt *authctxt)
875: {
876: /* initial userauth request */
877: packet_start(SSH2_MSG_USERAUTH_REQUEST);
878: packet_put_cstring(authctxt->server_user);
879: packet_put_cstring(authctxt->service);
880: packet_put_cstring(authctxt->method->name);
881: packet_send();
882: return 1;
883: }
884:
885: int
1.20 markus 886: userauth_passwd(Authctxt *authctxt)
1.1 markus 887: {
1.6 markus 888: static int attempt = 0;
1.99 markus 889: char prompt[150];
1.1 markus 890: char *password;
1.175 dtucker 891: const char *host = options.host_key_alias ? options.host_key_alias :
892: authctxt->host;
1.6 markus 893:
1.13 todd 894: if (attempt++ >= options.number_of_password_prompts)
1.6 markus 895: return 0;
1.13 todd 896:
1.87 deraadt 897: if (attempt != 1)
1.13 todd 898: error("Permission denied, please try again.");
1.1 markus 899:
1.43 itojun 900: snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ",
1.175 dtucker 901: authctxt->server_user, host);
1.1 markus 902: password = read_passphrase(prompt, 0);
903: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 904: packet_put_cstring(authctxt->server_user);
905: packet_put_cstring(authctxt->service);
1.23 markus 906: packet_put_cstring(authctxt->method->name);
1.1 markus 907: packet_put_char(0);
1.49 markus 908: packet_put_cstring(password);
1.204 djm 909: explicit_bzero(password, strlen(password));
1.197 djm 910: free(password);
1.85 markus 911: packet_add_padding(64);
1.1 markus 912: packet_send();
1.99 markus 913:
1.104 deraadt 914: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 915: &input_userauth_passwd_changereq);
916:
1.1 markus 917: return 1;
918: }
1.169 djm 919:
1.99 markus 920: /*
921: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
922: */
1.169 djm 923: /* ARGSUSED */
1.218 markus 924: int
1.261 markus 925: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 926: {
1.260 markus 927: Authctxt *authctxt = ssh->authctxt;
1.99 markus 928: char *info, *lang, *password = NULL, *retype = NULL;
929: char prompt[150];
1.252 djm 930: const char *host;
1.99 markus 931:
932: debug2("input_userauth_passwd_changereq");
933:
934: if (authctxt == NULL)
935: fatal("input_userauth_passwd_changereq: "
936: "no authentication context");
1.252 djm 937: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 938:
939: info = packet_get_string(NULL);
940: lang = packet_get_string(NULL);
941: if (strlen(info) > 0)
1.116 itojun 942: logit("%s", info);
1.197 djm 943: free(info);
944: free(lang);
1.99 markus 945: packet_start(SSH2_MSG_USERAUTH_REQUEST);
946: packet_put_cstring(authctxt->server_user);
947: packet_put_cstring(authctxt->service);
948: packet_put_cstring(authctxt->method->name);
949: packet_put_char(1); /* additional info */
1.104 deraadt 950: snprintf(prompt, sizeof(prompt),
1.99 markus 951: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 952: authctxt->server_user, host);
1.99 markus 953: password = read_passphrase(prompt, 0);
954: packet_put_cstring(password);
1.204 djm 955: explicit_bzero(password, strlen(password));
1.197 djm 956: free(password);
1.99 markus 957: password = NULL;
958: while (password == NULL) {
1.104 deraadt 959: snprintf(prompt, sizeof(prompt),
1.99 markus 960: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 961: authctxt->server_user, host);
1.99 markus 962: password = read_passphrase(prompt, RP_ALLOW_EOF);
963: if (password == NULL) {
964: /* bail out */
1.218 markus 965: return 0;
1.99 markus 966: }
1.104 deraadt 967: snprintf(prompt, sizeof(prompt),
1.99 markus 968: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 969: authctxt->server_user, host);
1.99 markus 970: retype = read_passphrase(prompt, 0);
971: if (strcmp(password, retype) != 0) {
1.204 djm 972: explicit_bzero(password, strlen(password));
1.197 djm 973: free(password);
1.116 itojun 974: logit("Mismatch; try again, EOF to quit.");
1.99 markus 975: password = NULL;
976: }
1.204 djm 977: explicit_bzero(retype, strlen(retype));
1.197 djm 978: free(retype);
1.99 markus 979: }
980: packet_put_cstring(password);
1.204 djm 981: explicit_bzero(password, strlen(password));
1.197 djm 982: free(password);
1.99 markus 983: packet_add_padding(64);
984: packet_send();
1.104 deraadt 985:
986: dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 987: &input_userauth_passwd_changereq);
1.218 markus 988: return 0;
1.117 markus 989: }
990:
1.231 markus 991: static const char *
1.255 djm 992: key_sign_encode(const struct sshkey *key)
1.231 markus 993: {
994: struct ssh *ssh = active_state;
995:
1.255 djm 996: if (key->type == KEY_RSA) {
1.231 markus 997: switch (ssh->kex->rsa_sha2) {
998: case 256:
999: return "rsa-sha2-256";
1000: case 512:
1001: return "rsa-sha2-512";
1002: }
1003: }
1.255 djm 1004: return key_ssh_name(key);
1.231 markus 1005: }
1006:
1.117 markus 1007: static int
1.214 djm 1008: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1009: const u_char *data, size_t datalen, u_int compat)
1.117 markus 1010: {
1.259 markus 1011: struct sshkey *prv;
1.117 markus 1012: int ret;
1.99 markus 1013:
1.117 markus 1014: /* the agent supports this key */
1.255 djm 1015: if (id->key != NULL && id->agent_fd != -1)
1.214 djm 1016: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1.255 djm 1017: data, datalen, key_sign_encode(id->key), compat);
1.214 djm 1018:
1.117 markus 1019: /*
1020: * we have already loaded the private key or
1021: * the private key is stored in external hardware
1022: */
1.255 djm 1023: if (id->key != NULL &&
1024: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT)))
1025: return (sshkey_sign(id->key, sigp, lenp, data, datalen,
1026: key_sign_encode(id->key), compat));
1027:
1.117 markus 1028: /* load the private key from the file */
1.229 jcs 1029: if ((prv = load_identity_file(id)) == NULL)
1.239 djm 1030: return SSH_ERR_KEY_NOT_FOUND;
1.255 djm 1031: ret = sshkey_sign(prv, sigp, lenp, data, datalen,
1032: key_sign_encode(prv), compat);
1.214 djm 1033: sshkey_free(prv);
1.117 markus 1034: return (ret);
1.51 markus 1035: }
1036:
1.76 itojun 1037: static int
1.255 djm 1038: id_filename_matches(Identity *id, Identity *private_id)
1039: {
1040: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1041: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1042: size_t i, slen;
1043:
1044: if (strcmp(id->filename, private_id->filename) == 0)
1045: return 1;
1046: for (i = 0; suffixes[i]; i++) {
1047: slen = strlen(suffixes[i]);
1048: if (len > slen && plen == len - slen &&
1049: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1050: memcmp(id->filename, private_id->filename, plen) == 0)
1051: return 1;
1052: }
1053: return 0;
1054: }
1055:
1056: static int
1.117 markus 1057: sign_and_send_pubkey(Authctxt *authctxt, Identity *id)
1.1 markus 1058: {
1059: Buffer b;
1.227 djm 1060: Identity *private_id;
1.32 markus 1061: u_char *blob, *signature;
1.214 djm 1062: size_t slen;
1.227 djm 1063: u_int bloblen, skip = 0;
1064: int matched, ret = -1, have_sig = 1;
1.182 djm 1065: char *fp;
1.1 markus 1066:
1.222 djm 1067: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1068: SSH_FP_DEFAULT)) == NULL)
1069: return 0;
1.227 djm 1070: debug3("%s: %s %s", __func__, key_type(id->key), fp);
1.197 djm 1071: free(fp);
1.51 markus 1072:
1.117 markus 1073: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.28 markus 1074: /* we cannot handle this key */
1.30 markus 1075: debug3("sign_and_send_pubkey: cannot handle key");
1.28 markus 1076: return 0;
1077: }
1.1 markus 1078: /* data to be signed */
1079: buffer_init(&b);
1.26 markus 1080: if (datafellows & SSH_OLD_SESSIONID) {
1081: buffer_append(&b, session_id2, session_id2_len);
1.41 stevesk 1082: skip = session_id2_len;
1.26 markus 1083: } else {
1.14 markus 1084: buffer_put_string(&b, session_id2, session_id2_len);
1085: skip = buffer_len(&b);
1086: }
1.1 markus 1087: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1088: buffer_put_cstring(&b, authctxt->server_user);
1.10 markus 1089: buffer_put_cstring(&b,
1.30 markus 1090: datafellows & SSH_BUG_PKSERVICE ?
1.10 markus 1091: "ssh-userauth" :
1.20 markus 1092: authctxt->service);
1.30 markus 1093: if (datafellows & SSH_BUG_PKAUTH) {
1094: buffer_put_char(&b, have_sig);
1095: } else {
1096: buffer_put_cstring(&b, authctxt->method->name);
1097: buffer_put_char(&b, have_sig);
1.255 djm 1098: buffer_put_cstring(&b, key_sign_encode(id->key));
1.30 markus 1099: }
1.1 markus 1100: buffer_put_string(&b, blob, bloblen);
1101:
1.227 djm 1102: /*
1103: * If the key is an certificate, try to find a matching private key
1104: * and use it to complete the signature.
1.241 djm 1105: * If no such private key exists, fall back to trying the certificate
1106: * key itself in case it has a private half already loaded.
1.227 djm 1107: */
1108: if (key_is_cert(id->key)) {
1109: matched = 0;
1110: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1111: if (sshkey_equal_public(id->key, private_id->key) &&
1112: id->key->type != private_id->key->type) {
1113: id = private_id;
1114: matched = 1;
1115: break;
1116: }
1117: }
1.255 djm 1118: /*
1119: * Exact key matches are preferred, but also allow
1120: * filename matches for non-PKCS#11/agent keys that
1121: * didn't load public keys. This supports the case
1122: * of keeping just a private key file and public
1123: * certificate on disk.
1124: */
1125: if (!matched && !id->isprivate && id->agent_fd == -1 &&
1126: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1127: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1128: if (private_id->key == NULL &&
1129: id_filename_matches(id, private_id)) {
1130: id = private_id;
1131: matched = 1;
1132: break;
1133: }
1134: }
1135: }
1.227 djm 1136: if (matched) {
1137: debug2("%s: using private key \"%s\"%s for "
1138: "certificate", __func__, id->filename,
1139: id->agent_fd != -1 ? " from agent" : "");
1140: } else {
1.240 djm 1141: debug("%s: no separate private key for certificate "
1.227 djm 1142: "\"%s\"", __func__, id->filename);
1143: }
1144: }
1145:
1.1 markus 1146: /* generate signature */
1.117 markus 1147: ret = identity_sign(id, &signature, &slen,
1.214 djm 1148: buffer_ptr(&b), buffer_len(&b), datafellows);
1149: if (ret != 0) {
1.239 djm 1150: if (ret != SSH_ERR_KEY_NOT_FOUND)
1151: error("%s: signing failed: %s", __func__, ssh_err(ret));
1.197 djm 1152: free(blob);
1.17 markus 1153: buffer_free(&b);
1154: return 0;
1155: }
1.28 markus 1156: #ifdef DEBUG_PK
1.1 markus 1157: buffer_dump(&b);
1158: #endif
1.30 markus 1159: if (datafellows & SSH_BUG_PKSERVICE) {
1.10 markus 1160: buffer_clear(&b);
1161: buffer_append(&b, session_id2, session_id2_len);
1.51 markus 1162: skip = session_id2_len;
1.10 markus 1163: buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
1.20 markus 1164: buffer_put_cstring(&b, authctxt->server_user);
1165: buffer_put_cstring(&b, authctxt->service);
1.23 markus 1166: buffer_put_cstring(&b, authctxt->method->name);
1167: buffer_put_char(&b, have_sig);
1.30 markus 1168: if (!(datafellows & SSH_BUG_PKAUTH))
1.117 markus 1169: buffer_put_cstring(&b, key_ssh_name(id->key));
1.10 markus 1170: buffer_put_string(&b, blob, bloblen);
1171: }
1.197 djm 1172: free(blob);
1.51 markus 1173:
1.1 markus 1174: /* append signature */
1175: buffer_put_string(&b, signature, slen);
1.197 djm 1176: free(signature);
1.1 markus 1177:
1178: /* skip session id and packet type */
1.14 markus 1179: if (buffer_len(&b) < skip + 1)
1.20 markus 1180: fatal("userauth_pubkey: internal error");
1.14 markus 1181: buffer_consume(&b, skip + 1);
1.1 markus 1182:
1183: /* put remaining data from buffer into packet */
1184: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1185: packet_put_raw(buffer_ptr(&b), buffer_len(&b));
1186: buffer_free(&b);
1187: packet_send();
1.17 markus 1188:
1189: return 1;
1.16 markus 1190: }
1191:
1.76 itojun 1192: static int
1.117 markus 1193: send_pubkey_test(Authctxt *authctxt, Identity *id)
1.20 markus 1194: {
1.51 markus 1195: u_char *blob;
1.97 markus 1196: u_int bloblen, have_sig = 0;
1.20 markus 1197:
1.51 markus 1198: debug3("send_pubkey_test");
1.16 markus 1199:
1.117 markus 1200: if (key_to_blob(id->key, &blob, &bloblen) == 0) {
1.51 markus 1201: /* we cannot handle this key */
1202: debug3("send_pubkey_test: cannot handle key");
1.16 markus 1203: return 0;
1204: }
1.51 markus 1205: /* register callback for USERAUTH_PK_OK message */
1206: dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1207:
1208: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1209: packet_put_cstring(authctxt->server_user);
1210: packet_put_cstring(authctxt->service);
1211: packet_put_cstring(authctxt->method->name);
1212: packet_put_char(have_sig);
1213: if (!(datafellows & SSH_BUG_PKAUTH))
1.255 djm 1214: packet_put_cstring(key_sign_encode(id->key));
1.51 markus 1215: packet_put_string(blob, bloblen);
1.197 djm 1216: free(blob);
1.51 markus 1217: packet_send();
1218: return 1;
1219: }
1220:
1.259 markus 1221: static struct sshkey *
1.229 jcs 1222: load_identity_file(Identity *id)
1.51 markus 1223: {
1.259 markus 1224: struct sshkey *private = NULL;
1.229 jcs 1225: char prompt[300], *passphrase, *comment;
1.215 djm 1226: int r, perm_ok = 0, quit = 0, i;
1.52 markus 1227: struct stat st;
1.16 markus 1228:
1.229 jcs 1229: if (stat(id->filename, &st) < 0) {
1230: (id->userprovided ? logit : debug3)("no such identity: %s: %s",
1231: id->filename, strerror(errno));
1.52 markus 1232: return NULL;
1233: }
1.214 djm 1234: snprintf(prompt, sizeof prompt,
1.229 jcs 1235: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1236: for (i = 0; i <= options.number_of_password_prompts; i++) {
1237: if (i == 0)
1238: passphrase = "";
1239: else {
1.20 markus 1240: passphrase = read_passphrase(prompt, 0);
1.214 djm 1241: if (*passphrase == '\0') {
1.20 markus 1242: debug2("no passphrase given, try next key");
1.214 djm 1243: free(passphrase);
1244: break;
1245: }
1246: }
1.229 jcs 1247: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1248: passphrase, &private, &comment, &perm_ok))) {
1.214 djm 1249: case 0:
1250: break;
1251: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1252: if (options.batch_mode) {
1253: quit = 1;
1254: break;
1255: }
1.215 djm 1256: if (i != 0)
1257: debug2("bad passphrase given, try again...");
1.214 djm 1258: break;
1259: case SSH_ERR_SYSTEM_ERROR:
1260: if (errno == ENOENT) {
1261: debug2("Load key \"%s\": %s",
1.229 jcs 1262: id->filename, ssh_err(r));
1.51 markus 1263: quit = 1;
1.214 djm 1264: break;
1.20 markus 1265: }
1.214 djm 1266: /* FALLTHROUGH */
1267: default:
1.229 jcs 1268: error("Load key \"%s\": %s", id->filename, ssh_err(r));
1.214 djm 1269: quit = 1;
1270: break;
1271: }
1.230 djm 1272: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1273: !(id->key && id->isprivate))
1274: maybe_add_key_to_agent(id->filename, private, comment,
1275: passphrase);
1.214 djm 1276: if (i > 0) {
1.204 djm 1277: explicit_bzero(passphrase, strlen(passphrase));
1.197 djm 1278: free(passphrase);
1.16 markus 1279: }
1.232 mmcc 1280: free(comment);
1.214 djm 1281: if (private != NULL || quit)
1282: break;
1.16 markus 1283: }
1.51 markus 1284: return private;
1285: }
1286:
1.117 markus 1287: /*
1288: * try keys in the following order:
1.227 djm 1289: * 1. certificates listed in the config file
1290: * 2. other input certificates
1291: * 3. agent keys that are found in the config file
1292: * 4. other agent keys
1293: * 5. keys that are only listed in the config file
1.117 markus 1294: */
1295: static void
1296: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1297: {
1.214 djm 1298: struct identity *id, *id2, *tmp;
1299: struct idlist agent, files, *preferred;
1300: struct sshkey *key;
1.230 djm 1301: int agent_fd = -1, i, r, found;
1.214 djm 1302: size_t j;
1303: struct ssh_identitylist *idlist;
1.51 markus 1304:
1.117 markus 1305: TAILQ_INIT(&agent); /* keys from the agent */
1306: TAILQ_INIT(&files); /* keys from the config file */
1307: preferred = &authctxt->keys;
1308: TAILQ_INIT(preferred); /* preferred order of keys */
1309:
1.190 djm 1310: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1311: for (i = 0; i < options.num_identity_files; i++) {
1312: key = options.identity_keys[i];
1.180 djm 1313: if (key && key->cert && key->cert->type != SSH2_CERT_TYPE_USER)
1.117 markus 1314: continue;
1315: options.identity_keys[i] = NULL;
1.150 djm 1316: id = xcalloc(1, sizeof(*id));
1.230 djm 1317: id->agent_fd = -1;
1.117 markus 1318: id->key = key;
1319: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1320: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1321: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1322: }
1.227 djm 1323: /* list of certificates specified by user */
1324: for (i = 0; i < options.num_certificate_files; i++) {
1325: key = options.certificates[i];
1326: if (!key_is_cert(key) || key->cert == NULL ||
1327: key->cert->type != SSH2_CERT_TYPE_USER)
1328: continue;
1329: id = xcalloc(1, sizeof(*id));
1.230 djm 1330: id->agent_fd = -1;
1.227 djm 1331: id->key = key;
1332: id->filename = xstrdup(options.certificate_files[i]);
1333: id->userprovided = options.certificate_file_userprovided[i];
1334: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1335: }
1336: /* list of keys supported by the agent */
1.214 djm 1337: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1338: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1339: debug("%s: ssh_get_authentication_socket: %s",
1340: __func__, ssh_err(r));
1.258 naddy 1341: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1342: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1343: debug("%s: ssh_fetch_identitylist: %s",
1344: __func__, ssh_err(r));
1.237 markus 1345: close(agent_fd);
1.214 djm 1346: } else {
1347: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1348: found = 0;
1349: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1350: /*
1351: * agent keys from the config file are
1352: * preferred
1353: */
1354: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1355: TAILQ_REMOVE(&files, id, next);
1356: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1357: id->agent_fd = agent_fd;
1.117 markus 1358: found = 1;
1359: break;
1360: }
1361: }
1.135 markus 1362: if (!found && !options.identities_only) {
1.150 djm 1363: id = xcalloc(1, sizeof(*id));
1.214 djm 1364: /* XXX "steals" key/comment from idlist */
1365: id->key = idlist->keys[j];
1366: id->filename = idlist->comments[j];
1367: idlist->keys[j] = NULL;
1368: idlist->comments[j] = NULL;
1369: id->agent_fd = agent_fd;
1.117 markus 1370: TAILQ_INSERT_TAIL(&agent, id, next);
1371: }
1372: }
1.214 djm 1373: ssh_free_identitylist(idlist);
1.117 markus 1374: /* append remaining agent keys */
1375: for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) {
1376: TAILQ_REMOVE(&agent, id, next);
1377: TAILQ_INSERT_TAIL(preferred, id, next);
1378: }
1.214 djm 1379: authctxt->agent_fd = agent_fd;
1.244 djm 1380: }
1381: /* Prefer PKCS11 keys that are explicitly listed */
1382: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1383: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1384: continue;
1385: found = 0;
1386: TAILQ_FOREACH(id2, &files, next) {
1387: if (id2->key == NULL ||
1388: (id2->key->flags & SSHKEY_FLAG_EXT) == 0)
1389: continue;
1390: if (sshkey_equal(id->key, id2->key)) {
1391: TAILQ_REMOVE(&files, id, next);
1392: TAILQ_INSERT_TAIL(preferred, id, next);
1393: found = 1;
1394: break;
1395: }
1396: }
1397: /* If IdentitiesOnly set and key not found then don't use it */
1398: if (!found && options.identities_only) {
1399: TAILQ_REMOVE(&files, id, next);
1400: explicit_bzero(id, sizeof(*id));
1401: free(id);
1402: }
1.117 markus 1403: }
1404: /* append remaining keys from the config file */
1405: for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) {
1406: TAILQ_REMOVE(&files, id, next);
1407: TAILQ_INSERT_TAIL(preferred, id, next);
1408: }
1.228 djm 1409: /* finally, filter by PubkeyAcceptedKeyTypes */
1410: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1411: if (id->key != NULL &&
1412: match_pattern_list(sshkey_ssh_name(id->key),
1413: options.pubkey_key_types, 0) != 1) {
1414: debug("Skipping %s key %s - "
1415: "not in PubkeyAcceptedKeyTypes",
1416: sshkey_ssh_name(id->key), id->filename);
1417: TAILQ_REMOVE(preferred, id, next);
1418: sshkey_free(id->key);
1419: free(id->filename);
1420: memset(id, 0, sizeof(*id));
1421: continue;
1422: }
1.230 djm 1423: debug2("key: %s (%p)%s%s", id->filename, id->key,
1424: id->userprovided ? ", explicit" : "",
1425: id->agent_fd != -1 ? ", agent" : "");
1.117 markus 1426: }
1.17 markus 1427: }
1428:
1.117 markus 1429: static void
1430: pubkey_cleanup(Authctxt *authctxt)
1.51 markus 1431: {
1.117 markus 1432: Identity *id;
1.51 markus 1433:
1.214 djm 1434: if (authctxt->agent_fd != -1)
1435: ssh_close_authentication_socket(authctxt->agent_fd);
1.117 markus 1436: for (id = TAILQ_FIRST(&authctxt->keys); id;
1437: id = TAILQ_FIRST(&authctxt->keys)) {
1438: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1439: sshkey_free(id->key);
1.197 djm 1440: free(id->filename);
1441: free(id);
1.117 markus 1442: }
1.1 markus 1443: }
1444:
1.251 djm 1445: static void
1446: pubkey_reset(Authctxt *authctxt)
1447: {
1448: Identity *id;
1449:
1450: TAILQ_FOREACH(id, &authctxt->keys, next)
1451: id->tried = 0;
1452: }
1453:
1.225 markus 1454: static int
1455: try_identity(Identity *id)
1456: {
1457: if (!id->key)
1458: return (0);
1459: if (key_type_plain(id->key->type) == KEY_RSA &&
1460: (datafellows & SSH_BUG_RSASIGMD5) != 0) {
1461: debug("Skipped %s key %s for RSA/MD5 server",
1462: key_type(id->key), id->filename);
1463: return (0);
1464: }
1.257 djm 1465: return 1;
1.225 markus 1466: }
1467:
1.20 markus 1468: int
1469: userauth_pubkey(Authctxt *authctxt)
1470: {
1.117 markus 1471: Identity *id;
1.20 markus 1472: int sent = 0;
1.256 djm 1473: char *fp;
1.20 markus 1474:
1.117 markus 1475: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1476: if (id->tried++)
1477: return (0);
1.127 markus 1478: /* move key to the end of the queue */
1.117 markus 1479: TAILQ_REMOVE(&authctxt->keys, id, next);
1480: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1481: /*
1482: * send a test message if we have the public key. for
1483: * encrypted keys we cannot do this and have to load the
1484: * private key instead
1485: */
1.200 djm 1486: if (id->key != NULL) {
1.225 markus 1487: if (try_identity(id)) {
1.256 djm 1488: if ((fp = sshkey_fingerprint(id->key,
1489: options.fingerprint_hash,
1490: SSH_FP_DEFAULT)) == NULL) {
1491: error("%s: sshkey_fingerprint failed",
1492: __func__);
1493: return 0;
1494: }
1495: debug("Offering public key: %s %s %s",
1496: sshkey_type(id->key), fp, id->filename);
1497: free(fp);
1.200 djm 1498: sent = send_pubkey_test(authctxt, id);
1499: }
1500: } else {
1.117 markus 1501: debug("Trying private key: %s", id->filename);
1.229 jcs 1502: id->key = load_identity_file(id);
1.117 markus 1503: if (id->key != NULL) {
1.225 markus 1504: if (try_identity(id)) {
1505: id->isprivate = 1;
1.200 djm 1506: sent = sign_and_send_pubkey(
1507: authctxt, id);
1508: }
1.117 markus 1509: key_free(id->key);
1510: id->key = NULL;
1.251 djm 1511: id->isprivate = 0;
1.51 markus 1512: }
1513: }
1.117 markus 1514: if (sent)
1515: return (sent);
1.28 markus 1516: }
1.117 markus 1517: return (0);
1.20 markus 1518: }
1519:
1.23 markus 1520: /*
1521: * Send userauth request message specifying keyboard-interactive method.
1522: */
1523: int
1524: userauth_kbdint(Authctxt *authctxt)
1525: {
1526: static int attempt = 0;
1527:
1528: if (attempt++ >= options.number_of_password_prompts)
1529: return 0;
1.82 markus 1530: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1531: if (attempt > 1 && !authctxt->info_req_seen) {
1532: debug3("userauth_kbdint: disable: no info_req_seen");
1533: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1534: return 0;
1535: }
1.23 markus 1536:
1537: debug2("userauth_kbdint");
1538: packet_start(SSH2_MSG_USERAUTH_REQUEST);
1539: packet_put_cstring(authctxt->server_user);
1540: packet_put_cstring(authctxt->service);
1541: packet_put_cstring(authctxt->method->name);
1542: packet_put_cstring(""); /* lang */
1543: packet_put_cstring(options.kbd_interactive_devices ?
1544: options.kbd_interactive_devices : "");
1545: packet_send();
1546:
1547: dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1548: return 1;
1549: }
1550:
1551: /*
1.46 markus 1552: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1553: */
1.218 markus 1554: int
1.261 markus 1555: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1556: {
1.260 markus 1557: Authctxt *authctxt = ssh->authctxt;
1.46 markus 1558: char *name, *inst, *lang, *prompt, *response;
1.32 markus 1559: u_int num_prompts, i;
1.23 markus 1560: int echo = 0;
1561:
1562: debug2("input_userauth_info_req");
1563:
1564: if (authctxt == NULL)
1565: fatal("input_userauth_info_req: no authentication context");
1.82 markus 1566:
1567: authctxt->info_req_seen = 1;
1.23 markus 1568:
1569: name = packet_get_string(NULL);
1570: inst = packet_get_string(NULL);
1571: lang = packet_get_string(NULL);
1572: if (strlen(name) > 0)
1.116 itojun 1573: logit("%s", name);
1.23 markus 1574: if (strlen(inst) > 0)
1.116 itojun 1575: logit("%s", inst);
1.197 djm 1576: free(name);
1577: free(inst);
1578: free(lang);
1.23 markus 1579:
1580: num_prompts = packet_get_int();
1581: /*
1582: * Begin to build info response packet based on prompts requested.
1583: * We commit to providing the correct number of responses, so if
1584: * further on we run into a problem that prevents this, we have to
1585: * be sure and clean this up and send a correct error response.
1586: */
1587: packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE);
1588: packet_put_int(num_prompts);
1589:
1.73 markus 1590: debug2("input_userauth_info_req: num_prompts %d", num_prompts);
1.23 markus 1591: for (i = 0; i < num_prompts; i++) {
1592: prompt = packet_get_string(NULL);
1593: echo = packet_get_char();
1594:
1.77 markus 1595: response = read_passphrase(prompt, echo ? RP_ECHO : 0);
1.23 markus 1596:
1.49 markus 1597: packet_put_cstring(response);
1.204 djm 1598: explicit_bzero(response, strlen(response));
1.197 djm 1599: free(response);
1600: free(prompt);
1.23 markus 1601: }
1.90 markus 1602: packet_check_eom(); /* done with parsing incoming message. */
1.23 markus 1603:
1.85 markus 1604: packet_add_padding(64);
1.23 markus 1605: packet_send();
1.218 markus 1606: return 0;
1.68 markus 1607: }
1608:
1.100 markus 1609: static int
1.223 djm 1610: ssh_keysign(struct sshkey *key, u_char **sigp, size_t *lenp,
1611: const u_char *data, size_t datalen)
1.100 markus 1612: {
1.223 djm 1613: struct sshbuf *b;
1.101 markus 1614: struct stat st;
1.100 markus 1615: pid_t pid;
1.223 djm 1616: int i, r, to[2], from[2], status, sock = packet_get_connection_in();
1617: u_char rversion = 0, version = 2;
1618: void (*osigchld)(int);
1.100 markus 1619:
1.223 djm 1620: *sigp = NULL;
1621: *lenp = 0;
1.100 markus 1622:
1.101 markus 1623: if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) {
1.223 djm 1624: error("%s: not installed: %s", __func__, strerror(errno));
1625: return -1;
1626: }
1627: if (fflush(stdout) != 0) {
1628: error("%s: fflush: %s", __func__, strerror(errno));
1.101 markus 1629: return -1;
1630: }
1.100 markus 1631: if (pipe(to) < 0) {
1.223 djm 1632: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1633: return -1;
1634: }
1635: if (pipe(from) < 0) {
1.223 djm 1636: error("%s: pipe: %s", __func__, strerror(errno));
1.100 markus 1637: return -1;
1638: }
1639: if ((pid = fork()) < 0) {
1.223 djm 1640: error("%s: fork: %s", __func__, strerror(errno));
1.100 markus 1641: return -1;
1642: }
1.223 djm 1643: osigchld = signal(SIGCHLD, SIG_DFL);
1.100 markus 1644: if (pid == 0) {
1.174 dtucker 1645: /* keep the socket on exec */
1.223 djm 1646: fcntl(sock, F_SETFD, 0);
1.155 markus 1647: permanently_drop_suid(getuid());
1.100 markus 1648: close(from[0]);
1649: if (dup2(from[1], STDOUT_FILENO) < 0)
1.223 djm 1650: fatal("%s: dup2: %s", __func__, strerror(errno));
1.100 markus 1651: close(to[1]);
1652: if (dup2(to[0], STDIN_FILENO) < 0)
1.223 djm 1653: fatal("%s: dup2: %s", __func__, strerror(errno));
1.103 markus 1654: close(from[1]);
1655: close(to[0]);
1.223 djm 1656: /* Close everything but stdio and the socket */
1657: for (i = STDERR_FILENO + 1; i < sock; i++)
1658: close(i);
1659: closefrom(sock + 1);
1660: debug3("%s: [child] pid=%ld, exec %s",
1661: __func__, (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 1662: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.223 djm 1663: fatal("%s: exec(%s): %s", __func__, _PATH_SSH_KEY_SIGN,
1.100 markus 1664: strerror(errno));
1665: }
1666: close(from[1]);
1667: close(to[0]);
1668:
1.223 djm 1669: if ((b = sshbuf_new()) == NULL)
1670: fatal("%s: sshbuf_new failed", __func__);
1671: /* send # of sock, data to be signed */
1.253 djm 1672: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 1673: (r = sshbuf_put_string(b, data, datalen)) != 0)
1674: fatal("%s: buffer error: %s", __func__, ssh_err(r));
1675: if (ssh_msg_send(to[1], version, b) == -1)
1676: fatal("%s: couldn't send request", __func__);
1677: sshbuf_reset(b);
1678: r = ssh_msg_recv(from[0], b);
1.101 markus 1679: close(from[0]);
1680: close(to[1]);
1.223 djm 1681: if (r < 0) {
1682: error("%s: no reply", __func__);
1683: goto fail;
1684: }
1.101 markus 1685:
1.223 djm 1686: errno = 0;
1687: while (waitpid(pid, &status, 0) < 0) {
1688: if (errno != EINTR) {
1689: error("%s: waitpid %ld: %s",
1690: __func__, (long)pid, strerror(errno));
1691: goto fail;
1692: }
1693: }
1694: if (!WIFEXITED(status)) {
1695: error("%s: exited abnormally", __func__);
1696: goto fail;
1697: }
1698: if (WEXITSTATUS(status) != 0) {
1699: error("%s: exited with status %d",
1700: __func__, WEXITSTATUS(status));
1701: goto fail;
1702: }
1703: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1704: error("%s: buffer error: %s", __func__, ssh_err(r));
1705: goto fail;
1706: }
1707: if (rversion != version) {
1708: error("%s: bad version", __func__);
1709: goto fail;
1710: }
1711: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1712: error("%s: buffer error: %s", __func__, ssh_err(r));
1713: fail:
1714: signal(SIGCHLD, osigchld);
1715: sshbuf_free(b);
1.100 markus 1716: return -1;
1717: }
1.223 djm 1718: signal(SIGCHLD, osigchld);
1719: sshbuf_free(b);
1.100 markus 1720:
1721: return 0;
1722: }
1723:
1.68 markus 1724: int
1725: userauth_hostbased(Authctxt *authctxt)
1726: {
1.223 djm 1727: struct ssh *ssh = active_state;
1728: struct sshkey *private = NULL;
1729: struct sshbuf *b = NULL;
1.72 markus 1730: const char *service;
1.223 djm 1731: u_char *sig = NULL, *keyblob = NULL;
1732: char *fp = NULL, *chost = NULL, *lname = NULL;
1733: size_t siglen = 0, keylen = 0;
1734: int i, r, success = 0;
1735:
1736: if (authctxt->ktypes == NULL) {
1737: authctxt->oktypes = xstrdup(options.hostbased_key_types);
1738: authctxt->ktypes = authctxt->oktypes;
1739: }
1.213 djm 1740:
1.223 djm 1741: /*
1742: * Work through each listed type pattern in HostbasedKeyTypes,
1743: * trying each hostkey that matches the type in turn.
1744: */
1745: for (;;) {
1746: if (authctxt->active_ktype == NULL)
1747: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
1748: if (authctxt->active_ktype == NULL ||
1749: *authctxt->active_ktype == '\0')
1750: break;
1751: debug3("%s: trying key type %s", __func__,
1752: authctxt->active_ktype);
1.68 markus 1753:
1.223 djm 1754: /* check for a useful key */
1755: private = NULL;
1756: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
1757: if (authctxt->sensitive->keys[i] == NULL ||
1758: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
1759: continue;
1760: if (match_pattern_list(
1761: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 1762: authctxt->active_ktype, 0) != 1)
1.223 djm 1763: continue;
1.68 markus 1764: /* we take and free the key */
1.223 djm 1765: private = authctxt->sensitive->keys[i];
1766: authctxt->sensitive->keys[i] = NULL;
1.68 markus 1767: break;
1768: }
1.223 djm 1769: /* Found one */
1770: if (private != NULL)
1771: break;
1772: /* No more keys of this type; advance */
1773: authctxt->active_ktype = NULL;
1.68 markus 1774: }
1.223 djm 1775: if (private == NULL) {
1776: free(authctxt->oktypes);
1777: authctxt->oktypes = authctxt->ktypes = NULL;
1778: authctxt->active_ktype = NULL;
1.109 markus 1779: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 1780: goto out;
1.68 markus 1781: }
1.211 djm 1782:
1.223 djm 1783: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
1784: SSH_FP_DEFAULT)) == NULL) {
1785: error("%s: sshkey_fingerprint failed", __func__);
1786: goto out;
1.68 markus 1787: }
1.223 djm 1788: debug("%s: trying hostkey %s %s",
1789: __func__, sshkey_ssh_name(private), fp);
1.211 djm 1790:
1.84 markus 1791: /* figure out a name for the client host */
1.223 djm 1792: if ((lname = get_local_name(packet_get_connection_in())) == NULL) {
1793: error("%s: cannot get local ipaddr/name", __func__);
1794: goto out;
1.84 markus 1795: }
1.223 djm 1796:
1797: /* XXX sshbuf_put_stringf? */
1798: xasprintf(&chost, "%s.", lname);
1799: debug2("%s: chost %s", __func__, chost);
1.84 markus 1800:
1.72 markus 1801: service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" :
1802: authctxt->service;
1.223 djm 1803:
1.68 markus 1804: /* construct data */
1.223 djm 1805: if ((b = sshbuf_new()) == NULL) {
1806: error("%s: sshbuf_new failed", __func__);
1807: goto out;
1808: }
1809: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1810: error("%s: sshkey_to_blob: %s", __func__, ssh_err(r));
1811: goto out;
1812: }
1813: if ((r = sshbuf_put_string(b, session_id2, session_id2_len)) != 0 ||
1814: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1815: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1816: (r = sshbuf_put_cstring(b, service)) != 0 ||
1817: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1818: (r = sshbuf_put_cstring(b, key_ssh_name(private))) != 0 ||
1819: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
1820: (r = sshbuf_put_cstring(b, chost)) != 0 ||
1821: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1822: error("%s: buffer error: %s", __func__, ssh_err(r));
1823: goto out;
1824: }
1825:
1.68 markus 1826: #ifdef DEBUG_PK
1.223 djm 1827: sshbuf_dump(b, stderr);
1.68 markus 1828: #endif
1.223 djm 1829: if (authctxt->sensitive->external_keysign)
1830: r = ssh_keysign(private, &sig, &siglen,
1831: sshbuf_ptr(b), sshbuf_len(b));
1832: else if ((r = sshkey_sign(private, &sig, &siglen,
1.231 markus 1833: sshbuf_ptr(b), sshbuf_len(b), NULL, datafellows)) != 0)
1.223 djm 1834: debug("%s: sshkey_sign: %s", __func__, ssh_err(r));
1835: if (r != 0) {
1836: error("sign using hostkey %s %s failed",
1837: sshkey_ssh_name(private), fp);
1838: goto out;
1839: }
1840: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1841: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1842: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1843: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1844: (r = sshpkt_put_cstring(ssh, key_ssh_name(private))) != 0 ||
1845: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
1846: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
1847: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
1848: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
1849: (r = sshpkt_send(ssh)) != 0) {
1850: error("%s: packet error: %s", __func__, ssh_err(r));
1851: goto out;
1852: }
1853: success = 1;
1854:
1855: out:
1856: if (sig != NULL) {
1857: explicit_bzero(sig, siglen);
1858: free(sig);
1.68 markus 1859: }
1.223 djm 1860: free(keyblob);
1861: free(lname);
1862: free(fp);
1.197 djm 1863: free(chost);
1.223 djm 1864: sshkey_free(private);
1865: sshbuf_free(b);
1.68 markus 1866:
1.223 djm 1867: return success;
1.23 markus 1868: }
1.170 djm 1869:
1.20 markus 1870: /* find auth method */
1871:
1872: /*
1873: * given auth method name, if configurable options permit this method fill
1874: * in auth_ident field and return true, otherwise return false.
1875: */
1.76 itojun 1876: static int
1.20 markus 1877: authmethod_is_enabled(Authmethod *method)
1878: {
1879: if (method == NULL)
1880: return 0;
1881: /* return false if options indicate this method is disabled */
1882: if (method->enabled == NULL || *method->enabled == 0)
1883: return 0;
1884: /* return false if batch mode is enabled but method needs interactive mode */
1885: if (method->batch_flag != NULL && *method->batch_flag != 0)
1886: return 0;
1887: return 1;
1888: }
1889:
1.76 itojun 1890: static Authmethod *
1.20 markus 1891: authmethod_lookup(const char *name)
1.1 markus 1892: {
1.20 markus 1893: Authmethod *method = NULL;
1894: if (name != NULL)
1895: for (method = authmethods; method->name != NULL; method++)
1896: if (strcmp(name, method->name) == 0)
1897: return method;
1898: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
1899: return NULL;
1900: }
1.1 markus 1901:
1.53 markus 1902: /* XXX internal state */
1903: static Authmethod *current = NULL;
1904: static char *supported = NULL;
1905: static char *preferred = NULL;
1.105 deraadt 1906:
1.20 markus 1907: /*
1908: * Given the authentication method list sent by the server, return the
1909: * next method we should try. If the server initially sends a nil list,
1.67 markus 1910: * use a built-in default list.
1.41 stevesk 1911: */
1.76 itojun 1912: static Authmethod *
1.20 markus 1913: authmethod_get(char *authlist)
1914: {
1.53 markus 1915: char *name = NULL;
1.97 markus 1916: u_int next;
1.41 stevesk 1917:
1.20 markus 1918: /* Use a suitable default if we're passed a nil list. */
1919: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 1920: authlist = options.preferred_authentications;
1.20 markus 1921:
1.53 markus 1922: if (supported == NULL || strcmp(authlist, supported) != 0) {
1923: debug3("start over, passed a different list %s", authlist);
1.197 djm 1924: free(supported);
1.53 markus 1925: supported = xstrdup(authlist);
1926: preferred = options.preferred_authentications;
1927: debug3("preferred %s", preferred);
1928: current = NULL;
1929: } else if (current != NULL && authmethod_is_enabled(current))
1930: return current;
1.20 markus 1931:
1.53 markus 1932: for (;;) {
1933: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 1934: debug("No more authentication methods to try.");
1.53 markus 1935: current = NULL;
1936: return NULL;
1937: }
1938: preferred += next;
1.23 markus 1939: debug3("authmethod_lookup %s", name);
1.53 markus 1940: debug3("remaining preferred: %s", preferred);
1941: if ((current = authmethod_lookup(name)) != NULL &&
1942: authmethod_is_enabled(current)) {
1.23 markus 1943: debug3("authmethod_is_enabled %s", name);
1.109 markus 1944: debug("Next authentication method: %s", name);
1.197 djm 1945: free(name);
1.53 markus 1946: return current;
1.23 markus 1947: }
1.198 dtucker 1948: free(name);
1.1 markus 1949: }
1.53 markus 1950: }
1.1 markus 1951:
1.79 stevesk 1952: static char *
1.53 markus 1953: authmethods_get(void)
1954: {
1955: Authmethod *method = NULL;
1.93 markus 1956: Buffer b;
1957: char *list;
1.27 provos 1958:
1.93 markus 1959: buffer_init(&b);
1.53 markus 1960: for (method = authmethods; method->name != NULL; method++) {
1961: if (authmethod_is_enabled(method)) {
1.93 markus 1962: if (buffer_len(&b) > 0)
1963: buffer_append(&b, ",", 1);
1964: buffer_append(&b, method->name, strlen(method->name));
1.53 markus 1965: }
1966: }
1.242 djm 1967: if ((list = sshbuf_dup_string(&b)) == NULL)
1968: fatal("%s: sshbuf_dup_string failed", __func__);
1.93 markus 1969: buffer_free(&b);
1970: return list;
1.1 markus 1971: }
1.170 djm 1972:
![[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