Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.346
1.346 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.345 2021/01/27 09:26:54 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>
1.336 djm 35: #include <limits.h>
1.164 jolan 36: #include <netdb.h>
1.159 stevesk 37: #include <stdio.h>
1.158 stevesk 38: #include <string.h>
1.313 deraadt 39: #include <stdarg.h>
1.160 deraadt 40: #include <signal.h>
41: #include <pwd.h>
1.157 stevesk 42: #include <unistd.h>
1.166 djm 43: #include <vis.h>
1.1 markus 44:
1.160 deraadt 45: #include "xmalloc.h"
1.1 markus 46: #include "ssh.h"
1.37 markus 47: #include "ssh2.h"
1.278 markus 48: #include "sshbuf.h"
1.1 markus 49: #include "packet.h"
50: #include "compat.h"
1.37 markus 51: #include "cipher.h"
1.278 markus 52: #include "sshkey.h"
1.1 markus 53: #include "kex.h"
54: #include "myproposal.h"
55: #include "sshconnect.h"
56: #include "authfile.h"
1.57 provos 57: #include "dh.h"
1.17 markus 58: #include "authfd.h"
1.37 markus 59: #include "log.h"
1.210 millert 60: #include "misc.h"
1.37 markus 61: #include "readconf.h"
1.53 markus 62: #include "match.h"
1.61 markus 63: #include "dispatch.h"
1.68 markus 64: #include "canohost.h"
1.100 markus 65: #include "msg.h"
66: #include "pathnames.h"
1.154 markus 67: #include "uidswap.h"
1.186 djm 68: #include "hostfile.h"
1.214 djm 69: #include "ssherr.h"
1.246 djm 70: #include "utf8.h"
1.309 djm 71: #include "ssh-sk.h"
1.312 djm 72: #include "sk-api.h"
1.22 provos 73:
1.121 markus 74: #ifdef GSSAPI
75: #include "ssh-gss.h"
76: #endif
1.293 djm 77:
1.1 markus 78: /* import */
79: extern char *client_version_string;
80: extern char *server_version_string;
81: extern Options options;
82:
83: /*
84: * SSH2 key exchange
85: */
86:
1.338 djm 87: static char *xxx_host;
88: static struct sockaddr *xxx_hostaddr;
89: static const struct ssh_conn_info *xxx_conn_info;
1.61 markus 90:
1.76 itojun 91: static int
1.259 markus 92: verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
1.61 markus 93: {
1.338 djm 94: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
95: xxx_conn_info) == -1)
1.83 markus 96: fatal("Host key verification failed.");
1.61 markus 97: return 0;
98: }
99:
1.326 djm 100: /* Returns the first item from a comma-separated algorithm list */
101: static char *
102: first_alg(const char *algs)
103: {
104: char *ret, *cp;
105:
106: ret = xstrdup(algs);
107: if ((cp = strchr(ret, ',')) != NULL)
108: *cp = '\0';
109: return ret;
110: }
111:
1.186 djm 112: static char *
1.338 djm 113: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port,
114: const struct ssh_conn_info *cinfo)
1.186 djm 115: {
1.326 djm 116: char *oavail = NULL, *avail = NULL, *first = NULL, *last = NULL;
117: char *alg = NULL, *hostname = NULL, *ret = NULL, *best = NULL;
1.186 djm 118: size_t maxlen;
1.326 djm 119: struct hostkeys *hostkeys = NULL;
1.186 djm 120: int ktype;
1.188 djm 121: u_int i;
1.186 djm 122:
123: /* Find all hostkeys for this hostname */
124: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
125: hostkeys = init_hostkeys();
1.188 djm 126: for (i = 0; i < options.num_user_hostfiles; i++)
1.337 djm 127: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i], 0);
128: for (i = 0; i < options.num_system_hostfiles; i++) {
129: load_hostkeys(hostkeys, hostname,
130: options.system_hostfiles[i], 0);
131: }
1.339 djm 132: if (options.known_hosts_command != NULL) {
133: load_hostkeys_command(hostkeys, options.known_hosts_command,
134: "ORDER", cinfo, NULL, host);
135: }
1.326 djm 136: /*
137: * If a plain public key exists that matches the type of the best
138: * preference HostkeyAlgorithms, then use the whole list as is.
139: * Note that we ignore whether the best preference algorithm is a
140: * certificate type, as sshconnect.c will downgrade certs to
141: * plain keys if necessary.
142: */
143: best = first_alg(options.hostkeyalgorithms);
144: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.328 djm 145: sshkey_type_plain(sshkey_type_from_name(best)),
146: sshkey_ecdsa_nid_from_name(best), NULL)) {
1.331 djm 147: debug3_f("have matching best-preference key type %s, "
148: "using HostkeyAlgorithms verbatim", best);
1.326 djm 149: ret = xstrdup(options.hostkeyalgorithms);
150: goto out;
151: }
152:
153: /*
154: * Otherwise, prefer the host key algorithms that match known keys
155: * while keeping the ordering of HostkeyAlgorithms as much as possible.
156: */
1.320 djm 157: oavail = avail = xstrdup(options.hostkeyalgorithms);
1.186 djm 158: maxlen = strlen(avail) + 1;
159: first = xmalloc(maxlen);
160: last = xmalloc(maxlen);
161: *first = *last = '\0';
162:
163: #define ALG_APPEND(to, from) \
164: do { \
165: if (*to != '\0') \
166: strlcat(to, ",", maxlen); \
167: strlcat(to, from, maxlen); \
168: } while (0)
169:
170: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 171: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.331 djm 172: fatal_f("unknown alg %s", alg);
1.322 djm 173: /*
174: * If we have a @cert-authority marker in known_hosts then
175: * prefer all certificate algorithms.
176: */
177: if (sshkey_type_is_cert(ktype) &&
178: lookup_marker_in_hostkeys(hostkeys, MRK_CA)) {
179: ALG_APPEND(first, alg);
180: continue;
181: }
182: /* If the key appears in known_hosts then prefer it */
1.186 djm 183: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.328 djm 184: sshkey_type_plain(ktype),
185: sshkey_ecdsa_nid_from_name(alg), NULL)) {
1.186 djm 186: ALG_APPEND(first, alg);
1.322 djm 187: continue;
188: }
189: /* Otherwise, put it last */
190: ALG_APPEND(last, alg);
1.186 djm 191: }
192: #undef ALG_APPEND
1.216 djm 193: xasprintf(&ret, "%s%s%s", first,
194: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 195: if (*first != '\0')
1.331 djm 196: debug3_f("prefer hostkeyalgs: %s", first);
1.339 djm 197: else
198: debug3_f("no algorithms matched; accept original");
1.326 djm 199: out:
200: free(best);
1.197 djm 201: free(first);
202: free(last);
203: free(hostname);
204: free(oavail);
1.186 djm 205: free_hostkeys(hostkeys);
206:
207: return ret;
208: }
209:
1.1 markus 210: void
1.338 djm 211: ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port,
212: const struct ssh_conn_info *cinfo)
1.22 provos 213: {
1.205 markus 214: char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
1.275 djm 215: char *s, *all_key;
1.320 djm 216: int r, use_known_hosts_order = 0;
1.61 markus 217:
218: xxx_host = host;
219: xxx_hostaddr = hostaddr;
1.338 djm 220: xxx_conn_info = cinfo;
1.22 provos 221:
1.320 djm 222: /*
223: * If the user has not specified HostkeyAlgorithms, or has only
224: * appended or removed algorithms from that list then prefer algorithms
225: * that are in the list that are supported by known_hosts keys.
226: */
227: if (options.hostkeyalgorithms == NULL ||
228: options.hostkeyalgorithms[0] == '-' ||
229: options.hostkeyalgorithms[0] == '+')
230: use_known_hosts_order = 1;
231:
232: /* Expand or fill in HostkeyAlgorithms */
233: all_key = sshkey_alg_list(0, 0, 1, ',');
1.333 djm 234: if ((r = kex_assemble_names(&options.hostkeyalgorithms,
235: kex_default_pk_alg(), all_key)) != 0)
236: fatal_fr(r, "kex_assemble_namelist");
1.320 djm 237: free(all_key);
238:
1.231 markus 239: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
1.331 djm 240: fatal_f("kex_names_cat");
1.345 djm 241: myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(ssh, s);
1.60 stevesk 242: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1.345 djm 243: compat_cipher_proposal(ssh, options.ciphers);
1.60 stevesk 244: myproposal[PROPOSAL_ENC_ALGS_STOC] =
1.345 djm 245: compat_cipher_proposal(ssh, options.ciphers);
1.245 dtucker 246: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.318 dtucker 247: myproposal[PROPOSAL_COMP_ALGS_STOC] =
248: (char *)compression_alg_list(options.compression);
1.226 djm 249: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
250: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1.320 djm 251: if (use_known_hosts_order) {
252: /* Query known_hosts and prefer algorithms that appear there */
1.88 deraadt 253: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.345 djm 254: compat_pkalg_proposal(ssh,
1.338 djm 255: order_hostkeyalgs(host, hostaddr, port, cinfo));
1.226 djm 256: } else {
1.320 djm 257: /* Use specified HostkeyAlgorithms exactly */
1.186 djm 258: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
1.345 djm 259: compat_pkalg_proposal(ssh, options.hostkeyalgorithms);
1.186 djm 260: }
1.115 markus 261:
1.196 dtucker 262: if (options.rekey_limit || options.rekey_interval)
1.294 djm 263: ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
1.254 dtucker 264: options.rekey_interval);
1.22 provos 265:
1.65 markus 266: /* start key exchange */
1.291 djm 267: if ((r = kex_setup(ssh, myproposal)) != 0)
1.331 djm 268: fatal_r(r, "kex_setup");
1.207 markus 269: #ifdef WITH_OPENSSL
1.301 djm 270: ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
271: ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
272: ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
273: ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
274: ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
1.291 djm 275: ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
276: ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.301 djm 277: ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
1.207 markus 278: #endif
1.301 djm 279: ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
1.340 djm 280: ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
1.291 djm 281: ssh->kex->verify_host_key=&verify_host_key_callback;
1.22 provos 282:
1.291 djm 283: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
1.173 andreas 284:
1.231 markus 285: /* remove ext-info from the KEX proposals for rekeying */
286: myproposal[PROPOSAL_KEX_ALGS] =
1.345 djm 287: compat_kex_proposal(ssh, options.kex_algorithms);
1.291 djm 288: if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
1.331 djm 289: fatal_r(r, "kex_prop2buf");
1.62 markus 290:
1.22 provos 291: #ifdef DEBUG_KEXDH
292: /* send 1st encrypted/maced/compressed message */
1.278 markus 293: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
294: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
1.280 markus 295: (r = sshpkt_send(ssh)) != 0 ||
296: (r = ssh_packet_write_wait(ssh)) != 0)
1.331 djm 297: fatal_fr(r, "send packet");
1.22 provos 298: #endif
1.1 markus 299: }
1.11 markus 300:
1.1 markus 301: /*
302: * Authenticate user
303: */
1.20 markus 304:
1.214 djm 305: typedef struct cauthctxt Authctxt;
306: typedef struct cauthmethod Authmethod;
1.117 markus 307: typedef struct identity Identity;
308: typedef struct idlist Idlist;
1.20 markus 309:
1.117 markus 310: struct identity {
311: TAILQ_ENTRY(identity) next;
1.214 djm 312: int agent_fd; /* >=0 if agent supports key */
313: struct sshkey *key; /* public/private key */
1.117 markus 314: char *filename; /* comment for agent-only keys */
315: int tried;
316: int isprivate; /* key points to the private key */
1.191 dtucker 317: int userprovided;
1.117 markus 318: };
319: TAILQ_HEAD(idlist, identity);
1.20 markus 320:
1.214 djm 321: struct cauthctxt {
1.20 markus 322: const char *server_user;
1.68 markus 323: const char *local_user;
1.20 markus 324: const char *host;
325: const char *service;
1.214 djm 326: struct cauthmethod *method;
1.183 djm 327: sig_atomic_t success;
1.51 markus 328: char *authlist;
1.302 djm 329: #ifdef GSSAPI
330: /* gssapi */
331: gss_OID_set gss_supported_mechs;
332: u_int mech_tried;
333: #endif
1.68 markus 334: /* pubkey */
1.214 djm 335: struct idlist keys;
336: int agent_fd;
1.68 markus 337: /* hostbased */
1.100 markus 338: Sensitive *sensitive;
1.223 djm 339: char *oktypes, *ktypes;
340: const char *active_ktype;
1.82 markus 341: /* kbd-interactive */
342: int info_req_seen;
1.292 djm 343: int attempt_kbdint;
344: /* password */
345: int attempt_passwd;
1.121 markus 346: /* generic */
347: void *methoddata;
1.20 markus 348: };
1.214 djm 349:
350: struct cauthmethod {
1.20 markus 351: char *name; /* string to compare against server's list */
1.295 djm 352: int (*userauth)(struct ssh *ssh);
353: void (*cleanup)(struct ssh *ssh);
1.20 markus 354: int *enabled; /* flag in option struct that enables method */
355: int *batch_flag; /* flag in option struct that disables method */
356: };
357:
1.302 djm 358: static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
359: static int input_userauth_ext_info(int, u_int32_t, struct ssh *);
360: static int input_userauth_success(int, u_int32_t, struct ssh *);
361: static int input_userauth_failure(int, u_int32_t, struct ssh *);
362: static int input_userauth_banner(int, u_int32_t, struct ssh *);
363: static int input_userauth_error(int, u_int32_t, struct ssh *);
364: static int input_userauth_info_req(int, u_int32_t, struct ssh *);
365: static int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
366: static int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
367:
368: static int userauth_none(struct ssh *);
369: static int userauth_pubkey(struct ssh *);
370: static int userauth_passwd(struct ssh *);
371: static int userauth_kbdint(struct ssh *);
372: static int userauth_hostbased(struct ssh *);
1.20 markus 373:
1.121 markus 374: #ifdef GSSAPI
1.302 djm 375: static int userauth_gssapi(struct ssh *);
376: static void userauth_gssapi_cleanup(struct ssh *);
377: static int input_gssapi_response(int type, u_int32_t, struct ssh *);
378: static int input_gssapi_token(int type, u_int32_t, struct ssh *);
379: static int input_gssapi_error(int, u_int32_t, struct ssh *);
380: static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
1.121 markus 381: #endif
382:
1.295 djm 383: void userauth(struct ssh *, char *);
1.51 markus 384:
1.303 djm 385: static void pubkey_cleanup(struct ssh *);
1.295 djm 386: static int sign_and_send_pubkey(struct ssh *ssh, Identity *);
1.117 markus 387: static void pubkey_prepare(Authctxt *);
1.251 djm 388: static void pubkey_reset(Authctxt *);
1.259 markus 389: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 390:
391: static Authmethod *authmethod_get(char *authlist);
392: static Authmethod *authmethod_lookup(const char *name);
393: static char *authmethods_get(void);
1.20 markus 394:
395: Authmethod authmethods[] = {
1.121 markus 396: #ifdef GSSAPI
1.132 markus 397: {"gssapi-with-mic",
1.121 markus 398: userauth_gssapi,
1.302 djm 399: userauth_gssapi_cleanup,
1.121 markus 400: &options.gss_authentication,
401: NULL},
402: #endif
1.81 markus 403: {"hostbased",
404: userauth_hostbased,
1.170 djm 405: NULL,
1.81 markus 406: &options.hostbased_authentication,
407: NULL},
1.20 markus 408: {"publickey",
409: userauth_pubkey,
1.303 djm 410: NULL,
1.28 markus 411: &options.pubkey_authentication,
1.20 markus 412: NULL},
1.81 markus 413: {"keyboard-interactive",
414: userauth_kbdint,
1.170 djm 415: NULL,
1.81 markus 416: &options.kbd_interactive_authentication,
417: &options.batch_mode},
1.20 markus 418: {"password",
419: userauth_passwd,
1.170 djm 420: NULL,
1.20 markus 421: &options.password_authentication,
1.23 markus 422: &options.batch_mode},
423: {"none",
424: userauth_none,
425: NULL,
1.170 djm 426: NULL,
1.23 markus 427: NULL},
1.170 djm 428: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 429: };
430:
431: void
1.291 djm 432: ssh_userauth2(struct ssh *ssh, const char *local_user,
433: const char *server_user, char *host, Sensitive *sensitive)
1.20 markus 434: {
435: Authctxt authctxt;
1.231 markus 436: int r;
1.39 markus 437:
1.73 markus 438: if (options.challenge_response_authentication)
1.39 markus 439: options.kbd_interactive_authentication = 1;
1.53 markus 440: if (options.preferred_authentications == NULL)
441: options.preferred_authentications = authmethods_get();
442:
1.20 markus 443: /* setup authentication context */
1.82 markus 444: memset(&authctxt, 0, sizeof(authctxt));
1.20 markus 445: authctxt.server_user = server_user;
1.68 markus 446: authctxt.local_user = local_user;
1.20 markus 447: authctxt.host = host;
448: authctxt.service = "ssh-connection"; /* service name */
449: authctxt.success = 0;
1.23 markus 450: authctxt.method = authmethod_lookup("none");
1.51 markus 451: authctxt.authlist = NULL;
1.121 markus 452: authctxt.methoddata = NULL;
1.100 markus 453: authctxt.sensitive = sensitive;
1.223 djm 454: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 455: authctxt.info_req_seen = 0;
1.292 djm 456: authctxt.attempt_kbdint = 0;
457: authctxt.attempt_passwd = 0;
1.302 djm 458: #if GSSAPI
459: authctxt.gss_supported_mechs = NULL;
460: authctxt.mech_tried = 0;
461: #endif
1.215 djm 462: authctxt.agent_fd = -1;
1.289 djm 463: pubkey_prepare(&authctxt);
1.291 djm 464: if (authctxt.method == NULL) {
1.331 djm 465: fatal_f("internal error: cannot send userauth none request");
1.291 djm 466: }
1.20 markus 467:
1.231 markus 468: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
469: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
470: (r = sshpkt_send(ssh)) != 0)
1.331 djm 471: fatal_fr(r, "send packet");
1.231 markus 472:
1.260 markus 473: ssh->authctxt = &authctxt;
1.231 markus 474: ssh_dispatch_init(ssh, &input_userauth_error);
475: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
476: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.263 markus 477: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.303 djm 478: pubkey_cleanup(ssh);
1.260 markus 479: ssh->authctxt = NULL;
1.20 markus 480:
1.231 markus 481: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 482:
1.248 dtucker 483: if (!authctxt.success)
484: fatal("Authentication failed.");
1.109 markus 485: debug("Authentication succeeded (%s).", authctxt.method->name);
1.20 markus 486: }
1.119 markus 487:
1.231 markus 488: /* ARGSUSED */
1.302 djm 489: static int
1.261 markus 490: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 491: {
492: int r;
493:
494: if (ssh_packet_remaining(ssh) > 0) {
495: char *reply;
496:
497: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
498: goto out;
499: debug2("service_accept: %s", reply);
500: free(reply);
501: } else {
502: debug2("buggy server: service_accept w/o service");
503: }
504: if ((r = sshpkt_get_end(ssh)) != 0)
505: goto out;
506: debug("SSH2_MSG_SERVICE_ACCEPT received");
507:
508: /* initial userauth request */
1.295 djm 509: userauth_none(ssh);
1.231 markus 510:
511: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
512: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
513: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
514: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
515: r = 0;
516: out:
517: return r;
518: }
519:
520: /* ARGSUSED */
1.302 djm 521: static int
1.261 markus 522: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 523: {
1.261 markus 524: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 525: }
526:
1.20 markus 527: void
1.295 djm 528: userauth(struct ssh *ssh, char *authlist)
1.51 markus 529: {
1.295 djm 530: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 531:
1.170 djm 532: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 533: authctxt->method->cleanup(ssh);
1.170 djm 534:
1.197 djm 535: free(authctxt->methoddata);
536: authctxt->methoddata = NULL;
1.51 markus 537: if (authlist == NULL) {
538: authlist = authctxt->authlist;
539: } else {
1.197 djm 540: free(authctxt->authlist);
1.51 markus 541: authctxt->authlist = authlist;
542: }
543: for (;;) {
544: Authmethod *method = authmethod_get(authlist);
545: if (method == NULL)
1.264 dtucker 546: fatal("%s@%s: Permission denied (%s).",
547: authctxt->server_user, authctxt->host, authlist);
1.51 markus 548: authctxt->method = method;
1.119 markus 549:
550: /* reset the per method handler */
1.278 markus 551: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 552: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
553:
554: /* and try new method */
1.295 djm 555: if (method->userauth(ssh) != 0) {
1.51 markus 556: debug2("we sent a %s packet, wait for reply", method->name);
557: break;
558: } else {
559: debug2("we did not send a packet, disable method");
560: method->enabled = NULL;
561: }
562: }
563: }
1.105 deraadt 564:
1.169 djm 565: /* ARGSUSED */
1.302 djm 566: static int
1.261 markus 567: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 568: {
1.331 djm 569: fatal_f("bad message during authentication: type %d", type);
1.218 markus 570: return 0;
1.35 markus 571: }
1.105 deraadt 572:
1.169 djm 573: /* ARGSUSED */
1.302 djm 574: static int
1.261 markus 575: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 576: {
1.295 djm 577: char *msg = NULL;
1.294 djm 578: size_t len;
579: int r;
1.126 deraadt 580:
1.331 djm 581: debug3_f("entering");
1.294 djm 582: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 583: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 584: goto out;
1.246 djm 585: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
586: fmprintf(stderr, "%s", msg);
1.294 djm 587: r = 0;
588: out:
1.246 djm 589: free(msg);
1.294 djm 590: return r;
1.20 markus 591: }
1.105 deraadt 592:
1.169 djm 593: /* ARGSUSED */
1.302 djm 594: static int
1.261 markus 595: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 596: {
1.260 markus 597: Authctxt *authctxt = ssh->authctxt;
1.172 djm 598:
1.20 markus 599: if (authctxt == NULL)
1.331 djm 600: fatal_f("no authentication context");
1.197 djm 601: free(authctxt->authlist);
602: authctxt->authlist = NULL;
1.172 djm 603: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 604: authctxt->method->cleanup(ssh);
1.197 djm 605: free(authctxt->methoddata);
606: authctxt->methoddata = NULL;
1.20 markus 607: authctxt->success = 1; /* break out */
1.218 markus 608: return 0;
1.20 markus 609: }
1.105 deraadt 610:
1.302 djm 611: #if 0
612: static int
1.261 markus 613: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 614: {
1.260 markus 615: Authctxt *authctxt = ssh->authctxt;
1.172 djm 616:
617: if (authctxt == NULL)
1.331 djm 618: fatal_f("no authentication context");
1.172 djm 619:
620: fatal("Unexpected authentication success during %s.",
621: authctxt->method->name);
1.218 markus 622: return 0;
1.172 djm 623: }
1.302 djm 624: #endif
1.172 djm 625:
1.169 djm 626: /* ARGSUSED */
1.302 djm 627: static int
1.261 markus 628: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 629: {
1.260 markus 630: Authctxt *authctxt = ssh->authctxt;
1.20 markus 631: char *authlist = NULL;
1.278 markus 632: u_char partial;
1.20 markus 633:
634: if (authctxt == NULL)
635: fatal("input_userauth_failure: no authentication context");
636:
1.307 dtucker 637: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
638: sshpkt_get_u8(ssh, &partial) != 0 ||
639: sshpkt_get_end(ssh) != 0)
1.278 markus 640: goto out;
1.20 markus 641:
1.193 markus 642: if (partial != 0) {
1.247 dtucker 643: verbose("Authenticated with partial success.");
1.193 markus 644: /* reset state */
1.251 djm 645: pubkey_reset(authctxt);
1.193 markus 646: }
1.109 markus 647: debug("Authentications that can continue: %s", authlist);
1.20 markus 648:
1.295 djm 649: userauth(ssh, authlist);
1.278 markus 650: authlist = NULL;
651: out:
652: free(authlist);
1.218 markus 653: return 0;
1.51 markus 654: }
1.169 djm 655:
1.287 djm 656: /*
657: * Format an identity for logging including filename, key type, fingerprint
658: * and location (agent, etc.). Caller must free.
659: */
660: static char *
661: format_identity(Identity *id)
662: {
663: char *fp = NULL, *ret = NULL;
1.309 djm 664: const char *note = "";
1.287 djm 665:
666: if (id->key != NULL) {
667: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
668: SSH_FP_DEFAULT);
669: }
1.309 djm 670: if (id->key) {
671: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
672: note = " token";
1.311 markus 673: else if (sshkey_is_sk(id->key))
1.319 naddy 674: note = " authenticator";
1.309 djm 675: }
1.287 djm 676: xasprintf(&ret, "%s %s%s%s%s%s%s",
677: id->filename,
678: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
679: fp ? fp : "",
1.309 djm 680: id->userprovided ? " explicit" : "", note,
1.287 djm 681: id->agent_fd != -1 ? " agent" : "");
682: free(fp);
683: return ret;
684: }
685:
1.169 djm 686: /* ARGSUSED */
1.302 djm 687: static int
1.261 markus 688: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 689: {
1.260 markus 690: Authctxt *authctxt = ssh->authctxt;
1.259 markus 691: struct sshkey *key = NULL;
1.117 markus 692: Identity *id = NULL;
1.287 djm 693: int pktype, found = 0, sent = 0;
1.278 markus 694: size_t blen;
1.287 djm 695: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 696: u_char *pkblob = NULL;
697: int r;
1.51 markus 698:
699: if (authctxt == NULL)
700: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 701:
1.278 markus 702: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
703: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
704: (r = sshpkt_get_end(ssh)) != 0)
705: goto done;
1.51 markus 706:
1.278 markus 707: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 708: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 709: goto done;
710: }
1.278 markus 711: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 712: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 713: goto done;
714: }
715: if (key->type != pktype) {
716: error("input_userauth_pk_ok: type mismatch "
717: "for decoded key (received %d, expected %d)",
718: key->type, pktype);
719: goto done;
720: }
721:
1.127 markus 722: /*
723: * search keys in the reverse order, because last candidate has been
724: * moved to the end of the queue. this also avoids confusion by
725: * duplicate keys
726: */
1.136 henning 727: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 728: if (sshkey_equal(key, id->key)) {
1.287 djm 729: found = 1;
1.51 markus 730: break;
731: }
1.117 markus 732: }
1.287 djm 733: if (!found || id == NULL) {
734: fp = sshkey_fingerprint(key, options.fingerprint_hash,
735: SSH_FP_DEFAULT);
1.331 djm 736: error_f("server replied with unknown key: %s %s",
1.287 djm 737: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
738: goto done;
739: }
740: ident = format_identity(id);
741: debug("Server accepts key: %s", ident);
1.295 djm 742: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 743: r = 0;
744: done:
745: sshkey_free(key);
1.287 djm 746: free(ident);
747: free(fp);
1.197 djm 748: free(pkalg);
749: free(pkblob);
1.51 markus 750:
1.106 deraadt 751: /* try another method if we did not send a packet */
1.278 markus 752: if (r == 0 && sent == 0)
1.295 djm 753: userauth(ssh, NULL);
1.278 markus 754: return r;
1.20 markus 755: }
1.121 markus 756:
757: #ifdef GSSAPI
1.302 djm 758: static int
1.295 djm 759: userauth_gssapi(struct ssh *ssh)
1.121 markus 760: {
1.295 djm 761: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 762: Gssctxt *gssctxt = NULL;
763: OM_uint32 min;
1.278 markus 764: int r, ok = 0;
1.302 djm 765: gss_OID mech = NULL;
1.121 markus 766:
767: /* Try one GSSAPI method at a time, rather than sending them all at
768: * once. */
769:
1.302 djm 770: if (authctxt->gss_supported_mechs == NULL)
771: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 772:
1.302 djm 773: /* Check to see whether the mechanism is usable before we offer it */
774: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
775: !ok) {
776: mech = &authctxt->gss_supported_mechs->
777: elements[authctxt->mech_tried];
1.121 markus 778: /* My DER encoding requires length<128 */
1.302 djm 779: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
780: mech, authctxt->host)) {
1.121 markus 781: ok = 1; /* Mechanism works */
782: } else {
1.302 djm 783: authctxt->mech_tried++;
1.121 markus 784: }
785: }
786:
1.302 djm 787: if (!ok || mech == NULL)
1.139 djm 788: return 0;
1.121 markus 789:
790: authctxt->methoddata=(void *)gssctxt;
791:
1.278 markus 792: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
793: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
794: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
795: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
796: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 797: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 798: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 799: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
800: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 801: (r = sshpkt_send(ssh)) != 0)
1.331 djm 802: fatal_fr(r, "send packet");
1.278 markus 803:
804: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
805: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
806: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
807: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 808:
1.302 djm 809: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 810:
811: return 1;
812: }
813:
1.302 djm 814: static void
815: userauth_gssapi_cleanup(struct ssh *ssh)
816: {
817: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
818: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
819:
820: ssh_gssapi_delete_ctx(&gssctxt);
821: authctxt->methoddata = NULL;
822:
823: free(authctxt->gss_supported_mechs);
824: authctxt->gss_supported_mechs = NULL;
825: }
826:
1.130 markus 827: static OM_uint32
1.262 djm 828: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 829: {
1.260 markus 830: Authctxt *authctxt = ssh->authctxt;
1.130 markus 831: Gssctxt *gssctxt = authctxt->methoddata;
832: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 833: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
834: gss_buffer_desc gssbuf;
1.132 markus 835: OM_uint32 status, ms, flags;
1.278 markus 836: int r;
1.133 djm 837:
1.130 markus 838: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 839: recv_tok, &send_tok, &flags);
1.130 markus 840:
841: if (send_tok.length > 0) {
1.278 markus 842: u_char type = GSS_ERROR(status) ?
843: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
844: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
845:
846: if ((r = sshpkt_start(ssh, type)) != 0 ||
847: (r = sshpkt_put_string(ssh, send_tok.value,
848: send_tok.length)) != 0 ||
849: (r = sshpkt_send(ssh)) != 0)
1.331 djm 850: fatal_fr(r, "send %u packet", type);
1.133 djm 851:
1.130 markus 852: gss_release_buffer(&ms, &send_tok);
853: }
1.133 djm 854:
1.130 markus 855: if (status == GSS_S_COMPLETE) {
1.132 markus 856: /* send either complete or MIC, depending on mechanism */
857: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 858: if ((r = sshpkt_start(ssh,
859: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
860: (r = sshpkt_send(ssh)) != 0)
1.331 djm 861: fatal_fr(r, "send completion");
1.132 markus 862: } else {
1.278 markus 863: struct sshbuf *b;
864:
865: if ((b = sshbuf_new()) == NULL)
1.331 djm 866: fatal_f("sshbuf_new failed");
1.278 markus 867: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 ! djm 868: authctxt->service, "gssapi-with-mic",
! 869: ssh->kex->session_id);
1.132 markus 870:
1.278 markus 871: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 872: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 873: gssbuf.length = sshbuf_len(b);
1.133 djm 874:
1.132 markus 875: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 876:
1.132 markus 877: if (!GSS_ERROR(status)) {
1.278 markus 878: if ((r = sshpkt_start(ssh,
879: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
880: (r = sshpkt_put_string(ssh, mic.value,
881: mic.length)) != 0 ||
882: (r = sshpkt_send(ssh)) != 0)
1.331 djm 883: fatal_fr(r, "send MIC");
1.132 markus 884: }
1.133 djm 885:
1.278 markus 886: sshbuf_free(b);
1.132 markus 887: gss_release_buffer(&ms, &mic);
1.133 djm 888: }
1.130 markus 889: }
1.133 djm 890:
1.130 markus 891: return status;
892: }
893:
1.169 djm 894: /* ARGSUSED */
1.302 djm 895: static int
1.261 markus 896: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 897: {
1.260 markus 898: Authctxt *authctxt = ssh->authctxt;
1.121 markus 899: Gssctxt *gssctxt;
1.278 markus 900: size_t oidlen;
901: u_char *oidv = NULL;
902: int r;
1.121 markus 903:
904: if (authctxt == NULL)
905: fatal("input_gssapi_response: no authentication context");
906: gssctxt = authctxt->methoddata;
907:
908: /* Setup our OID */
1.278 markus 909: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
910: goto done;
1.121 markus 911:
1.129 markus 912: if (oidlen <= 2 ||
913: oidv[0] != SSH_GSS_OIDTYPE ||
914: oidv[1] != oidlen - 2) {
915: debug("Badly encoded mechanism OID received");
1.296 djm 916: userauth(ssh, NULL);
1.278 markus 917: goto ok;
1.121 markus 918: }
1.129 markus 919:
920: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
921: fatal("Server returned different OID than expected");
1.121 markus 922:
1.278 markus 923: if ((r = sshpkt_get_end(ssh)) != 0)
924: goto done;
1.121 markus 925:
1.262 djm 926: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 927: /* Start again with next method on list */
928: debug("Trying to start again");
1.296 djm 929: userauth(ssh, NULL);
1.278 markus 930: goto ok;
1.121 markus 931: }
1.278 markus 932: ok:
933: r = 0;
934: done:
935: free(oidv);
936: return r;
1.121 markus 937: }
938:
1.169 djm 939: /* ARGSUSED */
1.302 djm 940: static int
1.261 markus 941: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 942: {
1.260 markus 943: Authctxt *authctxt = ssh->authctxt;
1.121 markus 944: gss_buffer_desc recv_tok;
1.278 markus 945: u_char *p = NULL;
946: size_t len;
1.130 markus 947: OM_uint32 status;
1.278 markus 948: int r;
1.121 markus 949:
950: if (authctxt == NULL)
951: fatal("input_gssapi_response: no authentication context");
952:
1.278 markus 953: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
954: (r = sshpkt_get_end(ssh)) != 0)
955: goto out;
1.121 markus 956:
1.278 markus 957: recv_tok.value = p;
958: recv_tok.length = len;
1.262 djm 959: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 960:
1.278 markus 961: /* Start again with the next method in the list */
1.121 markus 962: if (GSS_ERROR(status)) {
1.296 djm 963: userauth(ssh, NULL);
1.278 markus 964: /* ok */
1.121 markus 965: }
1.278 markus 966: r = 0;
967: out:
968: free(p);
969: return r;
1.121 markus 970: }
971:
1.169 djm 972: /* ARGSUSED */
1.302 djm 973: static int
1.261 markus 974: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 975: {
1.260 markus 976: Authctxt *authctxt = ssh->authctxt;
1.121 markus 977: Gssctxt *gssctxt;
978: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
979: gss_buffer_desc recv_tok;
1.194 djm 980: OM_uint32 ms;
1.278 markus 981: u_char *p = NULL;
982: size_t len;
983: int r;
1.121 markus 984:
985: if (authctxt == NULL)
986: fatal("input_gssapi_response: no authentication context");
987: gssctxt = authctxt->methoddata;
988:
1.278 markus 989: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
990: (r = sshpkt_get_end(ssh)) != 0) {
991: free(p);
992: return r;
993: }
1.121 markus 994:
995: /* Stick it into GSSAPI and see what it says */
1.278 markus 996: recv_tok.value = p;
997: recv_tok.length = len;
1.194 djm 998: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 999: &recv_tok, &send_tok, NULL);
1.278 markus 1000: free(p);
1.121 markus 1001: gss_release_buffer(&ms, &send_tok);
1002:
1003: /* Server will be returning a failed packet after this one */
1.220 djm 1004: return 0;
1.121 markus 1005: }
1006:
1.169 djm 1007: /* ARGSUSED */
1.302 djm 1008: static int
1.261 markus 1009: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 1010: {
1.278 markus 1011: char *msg = NULL;
1012: char *lang = NULL;
1013: int r;
1.121 markus 1014:
1.278 markus 1015: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1016: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1017: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1018: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1019: goto out;
1020: r = sshpkt_get_end(ssh);
1.143 stevesk 1021: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1022: out:
1.197 djm 1023: free(msg);
1024: free(lang);
1.278 markus 1025: return r;
1.121 markus 1026: }
1027: #endif /* GSSAPI */
1.20 markus 1028:
1.302 djm 1029: static int
1.295 djm 1030: userauth_none(struct ssh *ssh)
1.23 markus 1031: {
1.295 djm 1032: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1033: int r;
1034:
1.23 markus 1035: /* initial userauth request */
1.278 markus 1036: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1037: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1038: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1039: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1040: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1041: fatal_fr(r, "send packet");
1.23 markus 1042: return 1;
1043: }
1044:
1.302 djm 1045: static int
1.295 djm 1046: userauth_passwd(struct ssh *ssh)
1.1 markus 1047: {
1.295 djm 1048: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1049: char *password, *prompt = NULL;
1.175 dtucker 1050: const char *host = options.host_key_alias ? options.host_key_alias :
1051: authctxt->host;
1.278 markus 1052: int r;
1.6 markus 1053:
1.292 djm 1054: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1055: return 0;
1.13 todd 1056:
1.292 djm 1057: if (authctxt->attempt_passwd != 1)
1.13 todd 1058: error("Permission denied, please try again.");
1.1 markus 1059:
1.290 djm 1060: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1061: password = read_passphrase(prompt, 0);
1.278 markus 1062: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1063: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1064: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1065: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1066: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1067: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1068: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1069: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1070: fatal_fr(r, "send packet");
1.99 markus 1071:
1.290 djm 1072: free(prompt);
1073: if (password != NULL)
1.278 markus 1074: freezero(password, strlen(password));
1075:
1076: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1077: &input_userauth_passwd_changereq);
1078:
1.1 markus 1079: return 1;
1080: }
1.169 djm 1081:
1.99 markus 1082: /*
1083: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1084: */
1.169 djm 1085: /* ARGSUSED */
1.302 djm 1086: static int
1.261 markus 1087: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1088: {
1.260 markus 1089: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1090: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1091: char prompt[256];
1.252 djm 1092: const char *host;
1.278 markus 1093: int r;
1.99 markus 1094:
1095: debug2("input_userauth_passwd_changereq");
1096:
1097: if (authctxt == NULL)
1098: fatal("input_userauth_passwd_changereq: "
1099: "no authentication context");
1.252 djm 1100: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1101:
1.278 markus 1102: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1103: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1104: goto out;
1.99 markus 1105: if (strlen(info) > 0)
1.116 itojun 1106: logit("%s", info);
1.278 markus 1107: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1108: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1109: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1110: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1111: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1112: goto out;
1113:
1.104 deraadt 1114: snprintf(prompt, sizeof(prompt),
1.99 markus 1115: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1116: authctxt->server_user, host);
1.99 markus 1117: password = read_passphrase(prompt, 0);
1.278 markus 1118: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1119: goto out;
1120:
1121: freezero(password, strlen(password));
1.99 markus 1122: password = NULL;
1123: while (password == NULL) {
1.104 deraadt 1124: snprintf(prompt, sizeof(prompt),
1.99 markus 1125: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1126: authctxt->server_user, host);
1.99 markus 1127: password = read_passphrase(prompt, RP_ALLOW_EOF);
1128: if (password == NULL) {
1129: /* bail out */
1.278 markus 1130: r = 0;
1131: goto out;
1.99 markus 1132: }
1.104 deraadt 1133: snprintf(prompt, sizeof(prompt),
1.99 markus 1134: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1135: authctxt->server_user, host);
1.99 markus 1136: retype = read_passphrase(prompt, 0);
1137: if (strcmp(password, retype) != 0) {
1.278 markus 1138: freezero(password, strlen(password));
1.116 itojun 1139: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1140: password = NULL;
1141: }
1.278 markus 1142: freezero(retype, strlen(retype));
1.99 markus 1143: }
1.278 markus 1144: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1145: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1146: (r = sshpkt_send(ssh)) != 0)
1147: goto out;
1.104 deraadt 1148:
1.278 markus 1149: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1150: &input_userauth_passwd_changereq);
1.278 markus 1151: r = 0;
1152: out:
1153: if (password)
1154: freezero(password, strlen(password));
1155: free(info);
1156: free(lang);
1157: return r;
1.117 markus 1158: }
1159:
1.272 djm 1160: /*
1161: * Select an algorithm for publickey signatures.
1162: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1163: *
1164: * Call with ssh==NULL to ignore server-sig-algs extension list and
1165: * only attempt with the key's base signature type.
1166: */
1167: static char *
1168: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1169: {
1.274 djm 1170: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.231 markus 1171:
1.272 djm 1172: /*
1173: * The signature algorithm will only differ from the key algorithm
1174: * for RSA keys/certs and when the server advertises support for
1175: * newer (SHA2) algorithms.
1176: */
1177: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1178: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1179: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1180: /* Filter base key signature alg against our configuration */
1.279 markus 1181: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1182: options.pubkey_accepted_algos, NULL);
1.231 markus 1183: }
1184:
1.272 djm 1185: /*
1186: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1187: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1188: * that also appears in the supported signature algorithms list from
1189: * the server.
1190: */
1.342 dtucker 1191: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1192: while ((cp = strsep(&allowed, ",")) != NULL) {
1193: if (sshkey_type_from_name(cp) != key->type)
1194: continue;
1.323 djm 1195: tmp = match_list(sshkey_sigalg_by_name(cp),
1196: ssh->kex->server_sig_algs, NULL);
1.274 djm 1197: if (tmp != NULL)
1198: alg = xstrdup(cp);
1199: free(tmp);
1.272 djm 1200: if (alg != NULL)
1201: break;
1.269 djm 1202: }
1.272 djm 1203: free(oallowed);
1204: return alg;
1.269 djm 1205: }
1206:
1.117 markus 1207: static int
1.214 djm 1208: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1209: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1210: {
1.309 djm 1211: struct sshkey *sign_key = NULL, *prv = NULL;
1.341 djm 1212: int retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1213: struct notifier_ctx *notifier = NULL;
1.325 djm 1214: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1215:
1216: *sigp = NULL;
1217: *lenp = 0;
1.99 markus 1218:
1.272 djm 1219: /* The agent supports this key. */
1.269 djm 1220: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1221: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1222: data, datalen, alg, compat);
1.269 djm 1223: }
1.214 djm 1224:
1.117 markus 1225: /*
1.272 djm 1226: * We have already loaded the private key or the private key is
1227: * stored in external hardware.
1.117 markus 1228: */
1.255 djm 1229: if (id->key != NULL &&
1.272 djm 1230: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1231: sign_key = id->key;
1232: } else {
1233: /* Load the private key from the file. */
1234: if ((prv = load_identity_file(id)) == NULL)
1235: return SSH_ERR_KEY_NOT_FOUND;
1236: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1237: error_f("private key %s contents do not match public",
1238: id->filename);
1.309 djm 1239: r = SSH_ERR_KEY_NOT_FOUND;
1240: goto out;
1241: }
1242: sign_key = prv;
1.325 djm 1243: if (sshkey_is_sk(sign_key)) {
1244: if ((sign_key->sk_flags &
1245: SSH_SK_USER_VERIFICATION_REQD)) {
1.341 djm 1246: retry_pin:
1.325 djm 1247: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1248: sshkey_type(sign_key), id->filename);
1249: pin = read_passphrase(prompt, 0);
1250: }
1251: if ((sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1252: /* XXX should batch mode just skip these? */
1253: if ((fp = sshkey_fingerprint(sign_key,
1254: options.fingerprint_hash,
1255: SSH_FP_DEFAULT)) == NULL)
1.331 djm 1256: fatal_f("fingerprint failed");
1.325 djm 1257: notifier = notify_start(options.batch_mode,
1258: "Confirm user presence for key %s %s",
1259: sshkey_type(sign_key), fp);
1260: free(fp);
1261: }
1.312 djm 1262: }
1.272 djm 1263: }
1.310 djm 1264: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1265: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1266: debug_fr(r, "sshkey_sign");
1.341 djm 1267: if (pin == NULL && !retried && sshkey_is_sk(sign_key) &&
1268: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1269: notify_complete(notifier, NULL);
1270: notifier = NULL;
1271: retried = 1;
1272: goto retry_pin;
1273: }
1.309 djm 1274: goto out;
1275: }
1.341 djm 1276:
1.309 djm 1277: /*
1278: * PKCS#11 tokens may not support all signature algorithms,
1279: * so check what we get back.
1280: */
1281: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1282: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1283: goto out;
1.265 djm 1284: }
1.309 djm 1285: /* success */
1286: r = 0;
1287: out:
1.325 djm 1288: free(prompt);
1289: if (pin != NULL)
1290: freezero(pin, strlen(pin));
1.341 djm 1291: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1292: sshkey_free(prv);
1.269 djm 1293: return r;
1.51 markus 1294: }
1295:
1.76 itojun 1296: static int
1.255 djm 1297: id_filename_matches(Identity *id, Identity *private_id)
1298: {
1299: const char *suffixes[] = { ".pub", "-cert.pub", NULL };
1300: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1301: size_t i, slen;
1302:
1303: if (strcmp(id->filename, private_id->filename) == 0)
1304: return 1;
1305: for (i = 0; suffixes[i]; i++) {
1306: slen = strlen(suffixes[i]);
1307: if (len > slen && plen == len - slen &&
1308: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1309: memcmp(id->filename, private_id->filename, plen) == 0)
1310: return 1;
1311: }
1312: return 0;
1313: }
1314:
1315: static int
1.295 djm 1316: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1317: {
1.295 djm 1318: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1319: struct sshbuf *b = NULL;
1320: Identity *private_id, *sign_id = NULL;
1321: u_char *signature = NULL;
1322: size_t slen = 0, skip = 0;
1323: int r, fallback_sigtype, sent = 0;
1324: char *alg = NULL, *fp = NULL;
1325: const char *loc = "";
1.1 markus 1326:
1.222 djm 1327: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1328: SSH_FP_DEFAULT)) == NULL)
1329: return 0;
1.51 markus 1330:
1.331 djm 1331: debug3_f("%s %s", sshkey_type(id->key), fp);
1.1 markus 1332:
1.227 djm 1333: /*
1334: * If the key is an certificate, try to find a matching private key
1335: * and use it to complete the signature.
1.241 djm 1336: * If no such private key exists, fall back to trying the certificate
1337: * key itself in case it has a private half already loaded.
1.272 djm 1338: * This will try to set sign_id to the private key that will perform
1339: * the signature.
1.227 djm 1340: */
1.272 djm 1341: if (sshkey_is_cert(id->key)) {
1.227 djm 1342: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1343: if (sshkey_equal_public(id->key, private_id->key) &&
1344: id->key->type != private_id->key->type) {
1.272 djm 1345: sign_id = private_id;
1.227 djm 1346: break;
1347: }
1348: }
1.255 djm 1349: /*
1350: * Exact key matches are preferred, but also allow
1351: * filename matches for non-PKCS#11/agent keys that
1352: * didn't load public keys. This supports the case
1353: * of keeping just a private key file and public
1354: * certificate on disk.
1355: */
1.272 djm 1356: if (sign_id == NULL &&
1357: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1358: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1359: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1360: if (private_id->key == NULL &&
1361: id_filename_matches(id, private_id)) {
1.272 djm 1362: sign_id = private_id;
1.255 djm 1363: break;
1364: }
1365: }
1366: }
1.272 djm 1367: if (sign_id != NULL) {
1.331 djm 1368: debug2_f("using private key \"%s\"%s for "
1369: "certificate", id->filename,
1.227 djm 1370: id->agent_fd != -1 ? " from agent" : "");
1371: } else {
1.331 djm 1372: debug_f("no separate private key for certificate "
1373: "\"%s\"", id->filename);
1.227 djm 1374: }
1375: }
1376:
1.272 djm 1377: /*
1378: * If the above didn't select another identity to do the signing
1379: * then default to the one we started with.
1380: */
1381: if (sign_id == NULL)
1382: sign_id = id;
1383:
1384: /* assemble and sign data */
1385: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1386: free(alg);
1387: slen = 0;
1388: signature = NULL;
1389: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1390: id->key)) == NULL) {
1.331 djm 1391: error_f("no mutual signature supported");
1.272 djm 1392: goto out;
1393: }
1.331 djm 1394: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1395:
1396: sshbuf_free(b);
1397: if ((b = sshbuf_new()) == NULL)
1.331 djm 1398: fatal_f("sshbuf_new failed");
1.345 djm 1399: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 ! djm 1400: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
! 1401: fatal_fr(r, "sshbuf_putb");
1.272 djm 1402: } else {
1.346 ! djm 1403: if ((r = sshbuf_put_stringb(b,
! 1404: ssh->kex->session_id)) != 0)
! 1405: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1406: }
1.278 markus 1407: skip = sshbuf_len(b);
1.272 djm 1408: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1409: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1410: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1411: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1412: (r = sshbuf_put_u8(b, 1)) != 0 ||
1413: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1414: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1415: fatal_fr(r, "assemble signed data");
1.272 djm 1416: }
1417:
1418: /* generate signature */
1419: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1420: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1421: if (r == 0)
1422: break;
1423: else if (r == SSH_ERR_KEY_NOT_FOUND)
1424: goto out; /* soft failure */
1425: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1426: !fallback_sigtype) {
1427: if (sign_id->agent_fd != -1)
1428: loc = "agent ";
1429: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1430: loc = "token ";
1431: logit("%skey %s %s returned incorrect signature type",
1432: loc, sshkey_type(id->key), fp);
1433: continue;
1434: }
1.331 djm 1435: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1436: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1437: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1438: goto out;
1.17 markus 1439: }
1.272 djm 1440: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1441: fatal_f("no signature");
1.51 markus 1442:
1.1 markus 1443: /* append signature */
1.272 djm 1444: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1445: fatal_fr(r, "append signature");
1.1 markus 1446:
1.272 djm 1447: #ifdef DEBUG_PK
1448: sshbuf_dump(b, stderr);
1449: #endif
1.1 markus 1450: /* skip session id and packet type */
1.272 djm 1451: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1452: fatal_fr(r, "consume");
1.1 markus 1453:
1454: /* put remaining data from buffer into packet */
1.272 djm 1455: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1456: (r = sshpkt_putb(ssh, b)) != 0 ||
1457: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1458: fatal_fr(r, "enqueue request");
1.272 djm 1459:
1460: /* success */
1461: sent = 1;
1.17 markus 1462:
1.272 djm 1463: out:
1464: free(fp);
1465: free(alg);
1466: sshbuf_free(b);
1467: freezero(signature, slen);
1468: return sent;
1.16 markus 1469: }
1470:
1.76 itojun 1471: static int
1.295 djm 1472: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1473: {
1.295 djm 1474: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1475: u_char *blob = NULL;
1476: char *alg = NULL;
1.278 markus 1477: size_t bloblen;
1478: u_int have_sig = 0;
1479: int sent = 0, r;
1.20 markus 1480:
1.272 djm 1481: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1482: debug_f("no mutual signature algorithm");
1.272 djm 1483: goto out;
1484: }
1.16 markus 1485:
1.278 markus 1486: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1487: /* we cannot handle this key */
1.331 djm 1488: debug3_f("cannot handle key");
1.272 djm 1489: goto out;
1.16 markus 1490: }
1.51 markus 1491: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1492: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1493:
1.278 markus 1494: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1495: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1496: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1497: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1498: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1499: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1500: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1501: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1502: fatal_fr(r, "send packet");
1.272 djm 1503: sent = 1;
1.278 markus 1504:
1505: out:
1.272 djm 1506: free(alg);
1.197 djm 1507: free(blob);
1.272 djm 1508: return sent;
1.51 markus 1509: }
1510:
1.259 markus 1511: static struct sshkey *
1.229 jcs 1512: load_identity_file(Identity *id)
1.51 markus 1513: {
1.259 markus 1514: struct sshkey *private = NULL;
1.229 jcs 1515: char prompt[300], *passphrase, *comment;
1.308 dtucker 1516: int r, quit = 0, i;
1.52 markus 1517: struct stat st;
1.16 markus 1518:
1.306 deraadt 1519: if (stat(id->filename, &st) == -1) {
1.330 djm 1520: do_log2(id->userprovided ?
1521: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1522: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1523: return NULL;
1524: }
1.214 djm 1525: snprintf(prompt, sizeof prompt,
1.229 jcs 1526: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1527: for (i = 0; i <= options.number_of_password_prompts; i++) {
1528: if (i == 0)
1529: passphrase = "";
1530: else {
1.20 markus 1531: passphrase = read_passphrase(prompt, 0);
1.214 djm 1532: if (*passphrase == '\0') {
1.20 markus 1533: debug2("no passphrase given, try next key");
1.214 djm 1534: free(passphrase);
1535: break;
1536: }
1537: }
1.229 jcs 1538: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1539: passphrase, &private, &comment))) {
1.214 djm 1540: case 0:
1541: break;
1542: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1543: if (options.batch_mode) {
1544: quit = 1;
1545: break;
1546: }
1.215 djm 1547: if (i != 0)
1548: debug2("bad passphrase given, try again...");
1.214 djm 1549: break;
1550: case SSH_ERR_SYSTEM_ERROR:
1551: if (errno == ENOENT) {
1.331 djm 1552: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1553: quit = 1;
1.214 djm 1554: break;
1.20 markus 1555: }
1.214 djm 1556: /* FALLTHROUGH */
1557: default:
1.331 djm 1558: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1559: quit = 1;
1560: break;
1561: }
1.311 markus 1562: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1563: options.sk_provider == NULL) {
1.319 naddy 1564: debug("key \"%s\" is an authenticator-hosted key, "
1565: "but no provider specified", id->filename);
1.309 djm 1566: sshkey_free(private);
1567: private = NULL;
1568: quit = 1;
1569: }
1.230 djm 1570: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1571: !(id->key && id->isprivate))
1572: maybe_add_key_to_agent(id->filename, private, comment,
1573: passphrase);
1.278 markus 1574: if (i > 0)
1575: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1576: free(comment);
1.214 djm 1577: if (private != NULL || quit)
1578: break;
1.16 markus 1579: }
1.51 markus 1580: return private;
1581: }
1582:
1.272 djm 1583: static int
1584: key_type_allowed_by_config(struct sshkey *key)
1585: {
1586: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1587: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1588: return 1;
1589:
1590: /* RSA keys/certs might be allowed by alternate signature types */
1591: switch (key->type) {
1592: case KEY_RSA:
1593: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1594: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1595: return 1;
1596: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1597: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1598: return 1;
1599: break;
1600: case KEY_RSA_CERT:
1601: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1602: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1603: return 1;
1604: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1605: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1606: return 1;
1607: break;
1608: }
1609: return 0;
1610: }
1611:
1612:
1.117 markus 1613: /*
1614: * try keys in the following order:
1.332 djm 1615: * 1. certificates listed in the config file
1616: * 2. other input certificates
1.227 djm 1617: * 3. agent keys that are found in the config file
1618: * 4. other agent keys
1619: * 5. keys that are only listed in the config file
1.117 markus 1620: */
1621: static void
1622: pubkey_prepare(Authctxt *authctxt)
1.51 markus 1623: {
1.214 djm 1624: struct identity *id, *id2, *tmp;
1625: struct idlist agent, files, *preferred;
1626: struct sshkey *key;
1.230 djm 1627: int agent_fd = -1, i, r, found;
1.214 djm 1628: size_t j;
1629: struct ssh_identitylist *idlist;
1.287 djm 1630: char *ident;
1.51 markus 1631:
1.117 markus 1632: TAILQ_INIT(&agent); /* keys from the agent */
1633: TAILQ_INIT(&files); /* keys from the config file */
1634: preferred = &authctxt->keys;
1635: TAILQ_INIT(preferred); /* preferred order of keys */
1636:
1.190 djm 1637: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1638: for (i = 0; i < options.num_identity_files; i++) {
1639: key = options.identity_keys[i];
1.309 djm 1640: if (key && key->cert &&
1641: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1642: debug_f("ignoring certificate %s: not a user "
1643: "certificate", options.identity_files[i]);
1.309 djm 1644: continue;
1645: }
1.311 markus 1646: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1647: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1648: "SecurityKeyProvider has been specified",
1.331 djm 1649: options.identity_files[i]);
1.117 markus 1650: continue;
1.309 djm 1651: }
1.117 markus 1652: options.identity_keys[i] = NULL;
1.150 djm 1653: id = xcalloc(1, sizeof(*id));
1.230 djm 1654: id->agent_fd = -1;
1.117 markus 1655: id->key = key;
1656: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1657: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1658: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1659: }
1.227 djm 1660: /* list of certificates specified by user */
1661: for (i = 0; i < options.num_certificate_files; i++) {
1662: key = options.certificates[i];
1.278 markus 1663: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1664: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1665: debug_f("ignoring certificate %s: not a user "
1666: "certificate", options.identity_files[i]);
1.227 djm 1667: continue;
1.309 djm 1668: }
1.311 markus 1669: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1670: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1671: "certificate %s as no "
1.309 djm 1672: "SecurityKeyProvider has been specified",
1.331 djm 1673: options.identity_files[i]);
1.309 djm 1674: continue;
1675: }
1.227 djm 1676: id = xcalloc(1, sizeof(*id));
1.230 djm 1677: id->agent_fd = -1;
1.227 djm 1678: id->key = key;
1679: id->filename = xstrdup(options.certificate_files[i]);
1680: id->userprovided = options.certificate_file_userprovided[i];
1681: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1682: }
1683: /* list of keys supported by the agent */
1.214 djm 1684: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1685: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1.331 djm 1686: debug_fr(r, "ssh_get_authentication_socket");
1.258 naddy 1687: } else if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1.214 djm 1688: if (r != SSH_ERR_AGENT_NO_IDENTITIES)
1.331 djm 1689: debug_fr(r, "ssh_fetch_identitylist");
1.237 markus 1690: close(agent_fd);
1.214 djm 1691: } else {
1692: for (j = 0; j < idlist->nkeys; j++) {
1.117 markus 1693: found = 0;
1694: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1695: /*
1696: * agent keys from the config file are
1697: * preferred
1698: */
1699: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1700: TAILQ_REMOVE(&files, id, next);
1701: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1702: id->agent_fd = agent_fd;
1.117 markus 1703: found = 1;
1704: break;
1705: }
1706: }
1.135 markus 1707: if (!found && !options.identities_only) {
1.150 djm 1708: id = xcalloc(1, sizeof(*id));
1.214 djm 1709: /* XXX "steals" key/comment from idlist */
1710: id->key = idlist->keys[j];
1711: id->filename = idlist->comments[j];
1712: idlist->keys[j] = NULL;
1713: idlist->comments[j] = NULL;
1714: id->agent_fd = agent_fd;
1.117 markus 1715: TAILQ_INSERT_TAIL(&agent, id, next);
1716: }
1717: }
1.214 djm 1718: ssh_free_identitylist(idlist);
1.117 markus 1719: /* append remaining agent keys */
1.324 bket 1720: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1721: authctxt->agent_fd = agent_fd;
1.244 djm 1722: }
1723: /* Prefer PKCS11 keys that are explicitly listed */
1724: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1725: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1726: continue;
1727: found = 0;
1728: TAILQ_FOREACH(id2, &files, next) {
1729: if (id2->key == NULL ||
1.321 djm 1730: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1731: continue;
1732: if (sshkey_equal(id->key, id2->key)) {
1733: TAILQ_REMOVE(&files, id, next);
1734: TAILQ_INSERT_TAIL(preferred, id, next);
1735: found = 1;
1736: break;
1737: }
1738: }
1739: /* If IdentitiesOnly set and key not found then don't use it */
1740: if (!found && options.identities_only) {
1741: TAILQ_REMOVE(&files, id, next);
1.278 markus 1742: freezero(id, sizeof(*id));
1.244 djm 1743: }
1.117 markus 1744: }
1745: /* append remaining keys from the config file */
1.324 bket 1746: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1747: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1748: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1749: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1750: debug("Skipping %s key %s - "
1.342 dtucker 1751: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1752: sshkey_ssh_name(id->key), id->filename);
1753: TAILQ_REMOVE(preferred, id, next);
1754: sshkey_free(id->key);
1755: free(id->filename);
1756: memset(id, 0, sizeof(*id));
1757: continue;
1758: }
1.117 markus 1759: }
1.287 djm 1760: /* List the keys we plan on using */
1761: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1762: ident = format_identity(id);
1763: debug("Will attempt key: %s", ident);
1764: free(ident);
1765: }
1.331 djm 1766: debug2_f("done");
1.17 markus 1767: }
1768:
1.117 markus 1769: static void
1.303 djm 1770: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1771: {
1.302 djm 1772: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1773: Identity *id;
1.51 markus 1774:
1.289 djm 1775: if (authctxt->agent_fd != -1) {
1.214 djm 1776: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1777: authctxt->agent_fd = -1;
1778: }
1.117 markus 1779: for (id = TAILQ_FIRST(&authctxt->keys); id;
1780: id = TAILQ_FIRST(&authctxt->keys)) {
1781: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1782: sshkey_free(id->key);
1.197 djm 1783: free(id->filename);
1784: free(id);
1.117 markus 1785: }
1.1 markus 1786: }
1787:
1.251 djm 1788: static void
1789: pubkey_reset(Authctxt *authctxt)
1790: {
1791: Identity *id;
1792:
1793: TAILQ_FOREACH(id, &authctxt->keys, next)
1794: id->tried = 0;
1795: }
1796:
1.225 markus 1797: static int
1.345 djm 1798: try_identity(struct ssh *ssh, Identity *id)
1.225 markus 1799: {
1800: if (!id->key)
1801: return (0);
1.279 markus 1802: if (sshkey_type_plain(id->key->type) == KEY_RSA &&
1.345 djm 1803: (ssh->compat & SSH_BUG_RSASIGMD5) != 0) {
1.225 markus 1804: debug("Skipped %s key %s for RSA/MD5 server",
1.279 markus 1805: sshkey_type(id->key), id->filename);
1.225 markus 1806: return (0);
1807: }
1.257 djm 1808: return 1;
1.225 markus 1809: }
1810:
1.302 djm 1811: static int
1.295 djm 1812: userauth_pubkey(struct ssh *ssh)
1.20 markus 1813: {
1.295 djm 1814: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1815: Identity *id;
1.20 markus 1816: int sent = 0;
1.287 djm 1817: char *ident;
1.20 markus 1818:
1.117 markus 1819: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1820: if (id->tried++)
1821: return (0);
1.127 markus 1822: /* move key to the end of the queue */
1.117 markus 1823: TAILQ_REMOVE(&authctxt->keys, id, next);
1824: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1825: /*
1826: * send a test message if we have the public key. for
1827: * encrypted keys we cannot do this and have to load the
1828: * private key instead
1829: */
1.200 djm 1830: if (id->key != NULL) {
1.345 djm 1831: if (try_identity(ssh, id)) {
1.287 djm 1832: ident = format_identity(id);
1833: debug("Offering public key: %s", ident);
1834: free(ident);
1.295 djm 1835: sent = send_pubkey_test(ssh, id);
1.200 djm 1836: }
1837: } else {
1.117 markus 1838: debug("Trying private key: %s", id->filename);
1.229 jcs 1839: id->key = load_identity_file(id);
1.117 markus 1840: if (id->key != NULL) {
1.345 djm 1841: if (try_identity(ssh, id)) {
1.225 markus 1842: id->isprivate = 1;
1.295 djm 1843: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1844: }
1.278 markus 1845: sshkey_free(id->key);
1.117 markus 1846: id->key = NULL;
1.251 djm 1847: id->isprivate = 0;
1.51 markus 1848: }
1849: }
1.117 markus 1850: if (sent)
1851: return (sent);
1.28 markus 1852: }
1.117 markus 1853: return (0);
1.20 markus 1854: }
1855:
1.23 markus 1856: /*
1857: * Send userauth request message specifying keyboard-interactive method.
1858: */
1.302 djm 1859: static int
1.295 djm 1860: userauth_kbdint(struct ssh *ssh)
1.23 markus 1861: {
1.295 djm 1862: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1863: int r;
1.23 markus 1864:
1.292 djm 1865: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1866: return 0;
1.82 markus 1867: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1868: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1869: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1870: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1871: return 0;
1872: }
1.23 markus 1873:
1874: debug2("userauth_kbdint");
1.278 markus 1875: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1876: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1877: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1878: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1879: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1880: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1881: options.kbd_interactive_devices : "")) != 0 ||
1882: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1883: fatal_fr(r, "send packet");
1.23 markus 1884:
1.278 markus 1885: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1886: return 1;
1887: }
1888:
1889: /*
1.46 markus 1890: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1891: */
1.302 djm 1892: static int
1.261 markus 1893: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1894: {
1.260 markus 1895: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1896: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1897: char *display_prompt = NULL, *response = NULL;
1.278 markus 1898: u_char echo = 0;
1.32 markus 1899: u_int num_prompts, i;
1.278 markus 1900: int r;
1.23 markus 1901:
1.335 djm 1902: debug2_f("entering");
1.23 markus 1903:
1904: if (authctxt == NULL)
1.335 djm 1905: fatal_f("no authentication context");
1.82 markus 1906:
1907: authctxt->info_req_seen = 1;
1.23 markus 1908:
1.278 markus 1909: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1910: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1911: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1912: goto out;
1.23 markus 1913: if (strlen(name) > 0)
1.116 itojun 1914: logit("%s", name);
1.23 markus 1915: if (strlen(inst) > 0)
1.116 itojun 1916: logit("%s", inst);
1.23 markus 1917:
1.278 markus 1918: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1919: goto out;
1.23 markus 1920: /*
1921: * Begin to build info response packet based on prompts requested.
1922: * We commit to providing the correct number of responses, so if
1923: * further on we run into a problem that prevents this, we have to
1924: * be sure and clean this up and send a correct error response.
1925: */
1.278 markus 1926: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1927: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1928: goto out;
1.23 markus 1929:
1.335 djm 1930: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1931: for (i = 0; i < num_prompts; i++) {
1.278 markus 1932: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1933: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1934: goto out;
1.336 djm 1935: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1936: authctxt->server_user, options.host_key_alias ?
1.336 djm 1937: options.host_key_alias : authctxt->host, prompt) == -1)
1938: fatal_f("asmprintf failed");
1.335 djm 1939: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1940: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1941: goto out;
1942: freezero(response, strlen(response));
1.197 djm 1943: free(prompt);
1.335 djm 1944: free(display_prompt);
1945: display_prompt = response = prompt = NULL;
1.23 markus 1946: }
1.278 markus 1947: /* done with parsing incoming message. */
1948: if ((r = sshpkt_get_end(ssh)) != 0 ||
1949: (r = sshpkt_add_padding(ssh, 64)) != 0)
1950: goto out;
1951: r = sshpkt_send(ssh);
1952: out:
1953: if (response)
1954: freezero(response, strlen(response));
1955: free(prompt);
1.335 djm 1956: free(display_prompt);
1.278 markus 1957: free(name);
1958: free(inst);
1959: free(lang);
1960: return r;
1.68 markus 1961: }
1962:
1.100 markus 1963: static int
1.294 djm 1964: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 1965: const u_char *data, size_t datalen)
1.100 markus 1966: {
1.223 djm 1967: struct sshbuf *b;
1.101 markus 1968: struct stat st;
1.100 markus 1969: pid_t pid;
1.304 deraadt 1970: int r, to[2], from[2], status;
1.295 djm 1971: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 1972: u_char rversion = 0, version = 2;
1973: void (*osigchld)(int);
1.100 markus 1974:
1.223 djm 1975: *sigp = NULL;
1976: *lenp = 0;
1.100 markus 1977:
1.306 deraadt 1978: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 1979: error_f("not installed: %s", strerror(errno));
1.223 djm 1980: return -1;
1981: }
1982: if (fflush(stdout) != 0) {
1.331 djm 1983: error_f("fflush: %s", strerror(errno));
1.101 markus 1984: return -1;
1985: }
1.306 deraadt 1986: if (pipe(to) == -1) {
1.331 djm 1987: error_f("pipe: %s", strerror(errno));
1.100 markus 1988: return -1;
1989: }
1.306 deraadt 1990: if (pipe(from) == -1) {
1.331 djm 1991: error_f("pipe: %s", strerror(errno));
1.100 markus 1992: return -1;
1993: }
1.306 deraadt 1994: if ((pid = fork()) == -1) {
1.331 djm 1995: error_f("fork: %s", strerror(errno));
1.100 markus 1996: return -1;
1997: }
1.317 dtucker 1998: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 1999: if (pid == 0) {
2000: close(from[0]);
1.306 deraadt 2001: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2002: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2003: close(to[1]);
1.306 deraadt 2004: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2005: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2006: close(from[1]);
2007: close(to[0]);
1.304 deraadt 2008:
1.306 deraadt 2009: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2010: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2011: sock = STDERR_FILENO + 1;
2012: fcntl(sock, F_SETFD, 0); /* keep the socket on exec */
1.223 djm 2013: closefrom(sock + 1);
1.304 deraadt 2014:
1.331 djm 2015: debug3_f("[child] pid=%ld, exec %s",
2016: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2017: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2018: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2019: strerror(errno));
2020: }
2021: close(from[1]);
2022: close(to[0]);
1.305 djm 2023: sock = STDERR_FILENO + 1;
1.100 markus 2024:
1.223 djm 2025: if ((b = sshbuf_new()) == NULL)
1.331 djm 2026: fatal_f("sshbuf_new failed");
1.223 djm 2027: /* send # of sock, data to be signed */
1.253 djm 2028: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2029: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2030: fatal_fr(r, "buffer error");
1.223 djm 2031: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2032: fatal_f("couldn't send request");
1.223 djm 2033: sshbuf_reset(b);
2034: r = ssh_msg_recv(from[0], b);
1.101 markus 2035: close(from[0]);
2036: close(to[1]);
1.223 djm 2037: if (r < 0) {
1.331 djm 2038: error_f("no reply");
1.223 djm 2039: goto fail;
2040: }
1.101 markus 2041:
1.223 djm 2042: errno = 0;
1.306 deraadt 2043: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2044: if (errno != EINTR) {
1.331 djm 2045: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2046: goto fail;
2047: }
2048: }
2049: if (!WIFEXITED(status)) {
1.331 djm 2050: error_f("exited abnormally");
1.223 djm 2051: goto fail;
2052: }
2053: if (WEXITSTATUS(status) != 0) {
1.331 djm 2054: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2055: goto fail;
2056: }
2057: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2058: error_fr(r, "buffer error");
1.223 djm 2059: goto fail;
2060: }
2061: if (rversion != version) {
1.331 djm 2062: error_f("bad version");
1.223 djm 2063: goto fail;
2064: }
2065: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2066: error_fr(r, "buffer error");
1.223 djm 2067: fail:
1.317 dtucker 2068: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2069: sshbuf_free(b);
1.100 markus 2070: return -1;
2071: }
1.317 dtucker 2072: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2073: sshbuf_free(b);
1.100 markus 2074:
2075: return 0;
2076: }
2077:
1.302 djm 2078: static int
1.295 djm 2079: userauth_hostbased(struct ssh *ssh)
1.68 markus 2080: {
1.295 djm 2081: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2082: struct sshkey *private = NULL;
2083: struct sshbuf *b = NULL;
2084: u_char *sig = NULL, *keyblob = NULL;
2085: char *fp = NULL, *chost = NULL, *lname = NULL;
2086: size_t siglen = 0, keylen = 0;
2087: int i, r, success = 0;
2088:
2089: if (authctxt->ktypes == NULL) {
1.344 dtucker 2090: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2091: authctxt->ktypes = authctxt->oktypes;
2092: }
1.213 djm 2093:
1.223 djm 2094: /*
1.344 dtucker 2095: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2096: * trying each hostkey that matches the type in turn.
2097: */
2098: for (;;) {
2099: if (authctxt->active_ktype == NULL)
2100: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2101: if (authctxt->active_ktype == NULL ||
2102: *authctxt->active_ktype == '\0')
2103: break;
1.331 djm 2104: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2105:
1.223 djm 2106: /* check for a useful key */
2107: private = NULL;
2108: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2109: if (authctxt->sensitive->keys[i] == NULL ||
2110: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2111: continue;
2112: if (match_pattern_list(
2113: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.224 djm 2114: authctxt->active_ktype, 0) != 1)
1.223 djm 2115: continue;
1.68 markus 2116: /* we take and free the key */
1.223 djm 2117: private = authctxt->sensitive->keys[i];
2118: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2119: break;
2120: }
1.223 djm 2121: /* Found one */
2122: if (private != NULL)
2123: break;
2124: /* No more keys of this type; advance */
2125: authctxt->active_ktype = NULL;
1.68 markus 2126: }
1.223 djm 2127: if (private == NULL) {
2128: free(authctxt->oktypes);
2129: authctxt->oktypes = authctxt->ktypes = NULL;
2130: authctxt->active_ktype = NULL;
1.109 markus 2131: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2132: goto out;
1.68 markus 2133: }
1.211 djm 2134:
1.223 djm 2135: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2136: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2137: error_f("sshkey_fingerprint failed");
1.223 djm 2138: goto out;
1.68 markus 2139: }
1.331 djm 2140: debug_f("trying hostkey %s %s", sshkey_ssh_name(private), fp);
1.211 djm 2141:
1.84 markus 2142: /* figure out a name for the client host */
1.295 djm 2143: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2144: if (lname == NULL) {
1.331 djm 2145: error_f("cannot get local ipaddr/name");
1.223 djm 2146: goto out;
1.84 markus 2147: }
1.223 djm 2148:
2149: /* XXX sshbuf_put_stringf? */
2150: xasprintf(&chost, "%s.", lname);
1.331 djm 2151: debug2_f("chost %s", chost);
1.84 markus 2152:
1.68 markus 2153: /* construct data */
1.223 djm 2154: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2155: error_f("sshbuf_new failed");
1.223 djm 2156: goto out;
2157: }
2158: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2159: error_fr(r, "sshkey_to_blob");
1.223 djm 2160: goto out;
2161: }
1.346 ! djm 2162: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2163: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2164: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2165: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2166: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2167: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2168: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2169: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2170: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2171: error_fr(r, "buffer error");
1.223 djm 2172: goto out;
2173: }
2174:
1.68 markus 2175: #ifdef DEBUG_PK
1.223 djm 2176: sshbuf_dump(b, stderr);
1.68 markus 2177: #endif
1.294 djm 2178: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2179: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2180: error("sign using hostkey %s %s failed",
2181: sshkey_ssh_name(private), fp);
2182: goto out;
2183: }
2184: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2185: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2186: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2187: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2188: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2189: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2190: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2191: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2192: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2193: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2194: error_fr(r, "packet error");
1.223 djm 2195: goto out;
2196: }
2197: success = 1;
2198:
2199: out:
1.278 markus 2200: if (sig != NULL)
2201: freezero(sig, siglen);
1.223 djm 2202: free(keyblob);
2203: free(lname);
2204: free(fp);
1.197 djm 2205: free(chost);
1.223 djm 2206: sshkey_free(private);
2207: sshbuf_free(b);
1.68 markus 2208:
1.223 djm 2209: return success;
1.23 markus 2210: }
1.170 djm 2211:
1.20 markus 2212: /* find auth method */
2213:
2214: /*
2215: * given auth method name, if configurable options permit this method fill
2216: * in auth_ident field and return true, otherwise return false.
2217: */
1.76 itojun 2218: static int
1.20 markus 2219: authmethod_is_enabled(Authmethod *method)
2220: {
2221: if (method == NULL)
2222: return 0;
2223: /* return false if options indicate this method is disabled */
2224: if (method->enabled == NULL || *method->enabled == 0)
2225: return 0;
2226: /* return false if batch mode is enabled but method needs interactive mode */
2227: if (method->batch_flag != NULL && *method->batch_flag != 0)
2228: return 0;
2229: return 1;
2230: }
2231:
1.76 itojun 2232: static Authmethod *
1.20 markus 2233: authmethod_lookup(const char *name)
1.1 markus 2234: {
1.20 markus 2235: Authmethod *method = NULL;
2236: if (name != NULL)
2237: for (method = authmethods; method->name != NULL; method++)
2238: if (strcmp(name, method->name) == 0)
2239: return method;
2240: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2241: return NULL;
2242: }
1.1 markus 2243:
1.53 markus 2244: /* XXX internal state */
2245: static Authmethod *current = NULL;
2246: static char *supported = NULL;
2247: static char *preferred = NULL;
1.105 deraadt 2248:
1.20 markus 2249: /*
2250: * Given the authentication method list sent by the server, return the
2251: * next method we should try. If the server initially sends a nil list,
1.67 markus 2252: * use a built-in default list.
1.41 stevesk 2253: */
1.76 itojun 2254: static Authmethod *
1.20 markus 2255: authmethod_get(char *authlist)
2256: {
1.53 markus 2257: char *name = NULL;
1.97 markus 2258: u_int next;
1.41 stevesk 2259:
1.20 markus 2260: /* Use a suitable default if we're passed a nil list. */
2261: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2262: authlist = options.preferred_authentications;
1.20 markus 2263:
1.53 markus 2264: if (supported == NULL || strcmp(authlist, supported) != 0) {
2265: debug3("start over, passed a different list %s", authlist);
1.197 djm 2266: free(supported);
1.53 markus 2267: supported = xstrdup(authlist);
2268: preferred = options.preferred_authentications;
2269: debug3("preferred %s", preferred);
2270: current = NULL;
2271: } else if (current != NULL && authmethod_is_enabled(current))
2272: return current;
1.20 markus 2273:
1.53 markus 2274: for (;;) {
2275: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2276: debug("No more authentication methods to try.");
1.53 markus 2277: current = NULL;
2278: return NULL;
2279: }
2280: preferred += next;
1.23 markus 2281: debug3("authmethod_lookup %s", name);
1.53 markus 2282: debug3("remaining preferred: %s", preferred);
2283: if ((current = authmethod_lookup(name)) != NULL &&
2284: authmethod_is_enabled(current)) {
1.23 markus 2285: debug3("authmethod_is_enabled %s", name);
1.109 markus 2286: debug("Next authentication method: %s", name);
1.197 djm 2287: free(name);
1.53 markus 2288: return current;
1.23 markus 2289: }
1.198 dtucker 2290: free(name);
1.1 markus 2291: }
1.53 markus 2292: }
1.1 markus 2293:
1.79 stevesk 2294: static char *
1.53 markus 2295: authmethods_get(void)
2296: {
2297: Authmethod *method = NULL;
1.278 markus 2298: struct sshbuf *b;
1.93 markus 2299: char *list;
1.278 markus 2300: int r;
1.27 provos 2301:
1.278 markus 2302: if ((b = sshbuf_new()) == NULL)
1.331 djm 2303: fatal_f("sshbuf_new failed");
1.53 markus 2304: for (method = authmethods; method->name != NULL; method++) {
2305: if (authmethod_is_enabled(method)) {
1.278 markus 2306: if ((r = sshbuf_putf(b, "%s%s",
2307: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2308: fatal_fr(r, "buffer error");
1.53 markus 2309: }
2310: }
1.278 markus 2311: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2312: fatal_f("sshbuf_dup_string failed");
1.278 markus 2313: sshbuf_free(b);
1.93 markus 2314: return list;
1.1 markus 2315: }
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