Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.370
1.370 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.369 2023/12/13 03:28:19 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 "sshconnect.h"
55: #include "authfile.h"
1.57 provos 56: #include "dh.h"
1.17 markus 57: #include "authfd.h"
1.37 markus 58: #include "log.h"
1.210 millert 59: #include "misc.h"
1.37 markus 60: #include "readconf.h"
1.53 markus 61: #include "match.h"
1.61 markus 62: #include "dispatch.h"
1.68 markus 63: #include "canohost.h"
1.100 markus 64: #include "msg.h"
65: #include "pathnames.h"
1.154 markus 66: #include "uidswap.h"
1.186 djm 67: #include "hostfile.h"
1.214 djm 68: #include "ssherr.h"
1.246 djm 69: #include "utf8.h"
1.309 djm 70: #include "ssh-sk.h"
1.312 djm 71: #include "sk-api.h"
1.22 provos 72:
1.121 markus 73: #ifdef GSSAPI
74: #include "ssh-gss.h"
75: #endif
1.293 djm 76:
1.1 markus 77: /* import */
78: extern char *client_version_string;
79: extern char *server_version_string;
80: extern Options options;
81:
82: /*
83: * SSH2 key exchange
84: */
85:
1.338 djm 86: static char *xxx_host;
87: static struct sockaddr *xxx_hostaddr;
88: static const struct ssh_conn_info *xxx_conn_info;
1.61 markus 89:
1.76 itojun 90: static int
1.259 markus 91: verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
1.61 markus 92: {
1.361 djm 93: int r;
94:
95: if ((r = sshkey_check_rsa_length(hostkey,
96: options.required_rsa_size)) != 0)
97: fatal_r(r, "Bad server host key");
1.338 djm 98: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
99: xxx_conn_info) == -1)
1.83 markus 100: fatal("Host key verification failed.");
1.61 markus 101: return 0;
102: }
103:
1.326 djm 104: /* Returns the first item from a comma-separated algorithm list */
105: static char *
106: first_alg(const char *algs)
107: {
108: char *ret, *cp;
109:
110: ret = xstrdup(algs);
111: if ((cp = strchr(ret, ',')) != NULL)
112: *cp = '\0';
113: return ret;
114: }
115:
1.186 djm 116: static char *
1.338 djm 117: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port,
118: const struct ssh_conn_info *cinfo)
1.186 djm 119: {
1.326 djm 120: char *oavail = NULL, *avail = NULL, *first = NULL, *last = NULL;
121: char *alg = NULL, *hostname = NULL, *ret = NULL, *best = NULL;
1.186 djm 122: size_t maxlen;
1.326 djm 123: struct hostkeys *hostkeys = NULL;
1.186 djm 124: int ktype;
1.188 djm 125: u_int i;
1.186 djm 126:
127: /* Find all hostkeys for this hostname */
128: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
129: hostkeys = init_hostkeys();
1.188 djm 130: for (i = 0; i < options.num_user_hostfiles; i++)
1.337 djm 131: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i], 0);
132: for (i = 0; i < options.num_system_hostfiles; i++) {
133: load_hostkeys(hostkeys, hostname,
134: options.system_hostfiles[i], 0);
135: }
1.339 djm 136: if (options.known_hosts_command != NULL) {
137: load_hostkeys_command(hostkeys, options.known_hosts_command,
1.369 djm 138: "ORDER", cinfo, NULL, hostname);
1.339 djm 139: }
1.326 djm 140: /*
141: * If a plain public key exists that matches the type of the best
142: * preference HostkeyAlgorithms, then use the whole list as is.
143: * Note that we ignore whether the best preference algorithm is a
144: * certificate type, as sshconnect.c will downgrade certs to
145: * plain keys if necessary.
146: */
147: best = first_alg(options.hostkeyalgorithms);
148: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.328 djm 149: sshkey_type_plain(sshkey_type_from_name(best)),
150: sshkey_ecdsa_nid_from_name(best), NULL)) {
1.331 djm 151: debug3_f("have matching best-preference key type %s, "
152: "using HostkeyAlgorithms verbatim", best);
1.326 djm 153: ret = xstrdup(options.hostkeyalgorithms);
154: goto out;
155: }
156:
157: /*
158: * Otherwise, prefer the host key algorithms that match known keys
159: * while keeping the ordering of HostkeyAlgorithms as much as possible.
160: */
1.320 djm 161: oavail = avail = xstrdup(options.hostkeyalgorithms);
1.186 djm 162: maxlen = strlen(avail) + 1;
163: first = xmalloc(maxlen);
164: last = xmalloc(maxlen);
165: *first = *last = '\0';
166:
167: #define ALG_APPEND(to, from) \
168: do { \
169: if (*to != '\0') \
170: strlcat(to, ",", maxlen); \
171: strlcat(to, from, maxlen); \
172: } while (0)
173:
174: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 175: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.331 djm 176: fatal_f("unknown alg %s", alg);
1.322 djm 177: /*
178: * If we have a @cert-authority marker in known_hosts then
179: * prefer all certificate algorithms.
180: */
181: if (sshkey_type_is_cert(ktype) &&
182: lookup_marker_in_hostkeys(hostkeys, MRK_CA)) {
183: ALG_APPEND(first, alg);
184: continue;
185: }
186: /* If the key appears in known_hosts then prefer it */
1.186 djm 187: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.328 djm 188: sshkey_type_plain(ktype),
189: sshkey_ecdsa_nid_from_name(alg), NULL)) {
1.186 djm 190: ALG_APPEND(first, alg);
1.322 djm 191: continue;
192: }
193: /* Otherwise, put it last */
194: ALG_APPEND(last, alg);
1.186 djm 195: }
196: #undef ALG_APPEND
1.216 djm 197: xasprintf(&ret, "%s%s%s", first,
198: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 199: if (*first != '\0')
1.331 djm 200: debug3_f("prefer hostkeyalgs: %s", first);
1.339 djm 201: else
202: debug3_f("no algorithms matched; accept original");
1.326 djm 203: out:
204: free(best);
1.197 djm 205: free(first);
206: free(last);
207: free(hostname);
208: free(oavail);
1.186 djm 209: free_hostkeys(hostkeys);
210:
211: return ret;
212: }
213:
1.1 markus 214: void
1.338 djm 215: ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port,
216: const struct ssh_conn_info *cinfo)
1.22 provos 217: {
1.364 dtucker 218: char *myproposal[PROPOSAL_MAX];
219: char *s, *all_key, *hkalgs = NULL;
1.366 dtucker 220: int r, use_known_hosts_order = 0;
1.61 markus 221:
222: xxx_host = host;
223: xxx_hostaddr = hostaddr;
1.338 djm 224: xxx_conn_info = cinfo;
1.22 provos 225:
1.364 dtucker 226: if (options.rekey_limit || options.rekey_interval)
227: ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
228: options.rekey_interval);
1.320 djm 229:
1.366 dtucker 230: /*
231: * If the user has not specified HostkeyAlgorithms, or has only
232: * appended or removed algorithms from that list then prefer algorithms
233: * that are in the list that are supported by known_hosts keys.
234: */
235: if (options.hostkeyalgorithms == NULL ||
236: options.hostkeyalgorithms[0] == '-' ||
237: options.hostkeyalgorithms[0] == '+')
238: use_known_hosts_order = 1;
239:
1.320 djm 240: /* Expand or fill in HostkeyAlgorithms */
241: all_key = sshkey_alg_list(0, 0, 1, ',');
1.333 djm 242: if ((r = kex_assemble_names(&options.hostkeyalgorithms,
243: kex_default_pk_alg(), all_key)) != 0)
244: fatal_fr(r, "kex_assemble_namelist");
1.320 djm 245: free(all_key);
246:
1.231 markus 247: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
1.331 djm 248: fatal_f("kex_names_cat");
1.115 markus 249:
1.366 dtucker 250: if (use_known_hosts_order)
1.364 dtucker 251: hkalgs = order_hostkeyalgs(host, hostaddr, port, cinfo);
252:
253: kex_proposal_populate_entries(ssh, myproposal, s, options.ciphers,
254: options.macs, compression_alg_list(options.compression),
255: hkalgs ? hkalgs : options.hostkeyalgorithms);
256:
257: free(hkalgs);
1.22 provos 258:
1.65 markus 259: /* start key exchange */
1.291 djm 260: if ((r = kex_setup(ssh, myproposal)) != 0)
1.331 djm 261: fatal_r(r, "kex_setup");
1.207 markus 262: #ifdef WITH_OPENSSL
1.301 djm 263: ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
264: ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
265: ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
266: ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
267: ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
1.291 djm 268: ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
269: ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.301 djm 270: ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
1.207 markus 271: #endif
1.301 djm 272: ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
1.340 djm 273: ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
1.291 djm 274: ssh->kex->verify_host_key=&verify_host_key_callback;
1.22 provos 275:
1.291 djm 276: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
1.173 andreas 277:
1.231 markus 278: /* remove ext-info from the KEX proposals for rekeying */
1.364 dtucker 279: free(myproposal[PROPOSAL_KEX_ALGS]);
1.231 markus 280: myproposal[PROPOSAL_KEX_ALGS] =
1.345 djm 281: compat_kex_proposal(ssh, options.kex_algorithms);
1.291 djm 282: if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
1.331 djm 283: fatal_r(r, "kex_prop2buf");
1.62 markus 284:
1.22 provos 285: #ifdef DEBUG_KEXDH
286: /* send 1st encrypted/maced/compressed message */
1.278 markus 287: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
288: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
1.280 markus 289: (r = sshpkt_send(ssh)) != 0 ||
290: (r = ssh_packet_write_wait(ssh)) != 0)
1.331 djm 291: fatal_fr(r, "send packet");
1.22 provos 292: #endif
1.364 dtucker 293: kex_proposal_free_entries(myproposal);
1.1 markus 294: }
1.11 markus 295:
1.1 markus 296: /*
297: * Authenticate user
298: */
1.20 markus 299:
1.214 djm 300: typedef struct cauthctxt Authctxt;
301: typedef struct cauthmethod Authmethod;
1.117 markus 302: typedef struct identity Identity;
303: typedef struct idlist Idlist;
1.20 markus 304:
1.117 markus 305: struct identity {
306: TAILQ_ENTRY(identity) next;
1.214 djm 307: int agent_fd; /* >=0 if agent supports key */
308: struct sshkey *key; /* public/private key */
1.117 markus 309: char *filename; /* comment for agent-only keys */
310: int tried;
311: int isprivate; /* key points to the private key */
1.191 dtucker 312: int userprovided;
1.117 markus 313: };
314: TAILQ_HEAD(idlist, identity);
1.20 markus 315:
1.214 djm 316: struct cauthctxt {
1.20 markus 317: const char *server_user;
1.68 markus 318: const char *local_user;
1.20 markus 319: const char *host;
320: const char *service;
1.214 djm 321: struct cauthmethod *method;
1.183 djm 322: sig_atomic_t success;
1.51 markus 323: char *authlist;
1.302 djm 324: #ifdef GSSAPI
325: /* gssapi */
326: gss_OID_set gss_supported_mechs;
327: u_int mech_tried;
328: #endif
1.68 markus 329: /* pubkey */
1.214 djm 330: struct idlist keys;
331: int agent_fd;
1.68 markus 332: /* hostbased */
1.100 markus 333: Sensitive *sensitive;
1.223 djm 334: char *oktypes, *ktypes;
335: const char *active_ktype;
1.82 markus 336: /* kbd-interactive */
337: int info_req_seen;
1.292 djm 338: int attempt_kbdint;
339: /* password */
340: int attempt_passwd;
1.121 markus 341: /* generic */
342: void *methoddata;
1.20 markus 343: };
1.214 djm 344:
345: struct cauthmethod {
1.20 markus 346: char *name; /* string to compare against server's list */
1.295 djm 347: int (*userauth)(struct ssh *ssh);
348: void (*cleanup)(struct ssh *ssh);
1.20 markus 349: int *enabled; /* flag in option struct that enables method */
350: int *batch_flag; /* flag in option struct that disables method */
351: };
352:
1.302 djm 353: static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
354: static int input_userauth_success(int, u_int32_t, struct ssh *);
355: static int input_userauth_failure(int, u_int32_t, struct ssh *);
356: static int input_userauth_banner(int, u_int32_t, struct ssh *);
357: static int input_userauth_error(int, u_int32_t, struct ssh *);
358: static int input_userauth_info_req(int, u_int32_t, struct ssh *);
359: static int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
360: static int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
361:
362: static int userauth_none(struct ssh *);
363: static int userauth_pubkey(struct ssh *);
364: static int userauth_passwd(struct ssh *);
365: static int userauth_kbdint(struct ssh *);
366: static int userauth_hostbased(struct ssh *);
1.20 markus 367:
1.121 markus 368: #ifdef GSSAPI
1.302 djm 369: static int userauth_gssapi(struct ssh *);
370: static void userauth_gssapi_cleanup(struct ssh *);
371: static int input_gssapi_response(int type, u_int32_t, struct ssh *);
372: static int input_gssapi_token(int type, u_int32_t, struct ssh *);
373: static int input_gssapi_error(int, u_int32_t, struct ssh *);
374: static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
1.121 markus 375: #endif
376:
1.295 djm 377: void userauth(struct ssh *, char *);
1.51 markus 378:
1.303 djm 379: static void pubkey_cleanup(struct ssh *);
1.295 djm 380: static int sign_and_send_pubkey(struct ssh *ssh, Identity *);
1.352 djm 381: static void pubkey_prepare(struct ssh *, Authctxt *);
1.251 djm 382: static void pubkey_reset(Authctxt *);
1.259 markus 383: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 384:
385: static Authmethod *authmethod_get(char *authlist);
386: static Authmethod *authmethod_lookup(const char *name);
387: static char *authmethods_get(void);
1.20 markus 388:
389: Authmethod authmethods[] = {
1.121 markus 390: #ifdef GSSAPI
1.132 markus 391: {"gssapi-with-mic",
1.121 markus 392: userauth_gssapi,
1.302 djm 393: userauth_gssapi_cleanup,
1.121 markus 394: &options.gss_authentication,
395: NULL},
396: #endif
1.81 markus 397: {"hostbased",
398: userauth_hostbased,
1.170 djm 399: NULL,
1.81 markus 400: &options.hostbased_authentication,
401: NULL},
1.20 markus 402: {"publickey",
403: userauth_pubkey,
1.303 djm 404: NULL,
1.28 markus 405: &options.pubkey_authentication,
1.20 markus 406: NULL},
1.81 markus 407: {"keyboard-interactive",
408: userauth_kbdint,
1.170 djm 409: NULL,
1.81 markus 410: &options.kbd_interactive_authentication,
411: &options.batch_mode},
1.20 markus 412: {"password",
413: userauth_passwd,
1.170 djm 414: NULL,
1.20 markus 415: &options.password_authentication,
1.23 markus 416: &options.batch_mode},
417: {"none",
418: userauth_none,
419: NULL,
1.170 djm 420: NULL,
1.23 markus 421: NULL},
1.170 djm 422: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 423: };
424:
425: void
1.291 djm 426: ssh_userauth2(struct ssh *ssh, const char *local_user,
427: const char *server_user, char *host, Sensitive *sensitive)
1.20 markus 428: {
429: Authctxt authctxt;
1.231 markus 430: int r;
1.39 markus 431:
1.53 markus 432: if (options.preferred_authentications == NULL)
433: options.preferred_authentications = authmethods_get();
434:
1.20 markus 435: /* setup authentication context */
1.82 markus 436: memset(&authctxt, 0, sizeof(authctxt));
1.20 markus 437: authctxt.server_user = server_user;
1.68 markus 438: authctxt.local_user = local_user;
1.20 markus 439: authctxt.host = host;
440: authctxt.service = "ssh-connection"; /* service name */
441: authctxt.success = 0;
1.23 markus 442: authctxt.method = authmethod_lookup("none");
1.51 markus 443: authctxt.authlist = NULL;
1.121 markus 444: authctxt.methoddata = NULL;
1.100 markus 445: authctxt.sensitive = sensitive;
1.223 djm 446: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 447: authctxt.info_req_seen = 0;
1.292 djm 448: authctxt.attempt_kbdint = 0;
449: authctxt.attempt_passwd = 0;
1.302 djm 450: #if GSSAPI
451: authctxt.gss_supported_mechs = NULL;
452: authctxt.mech_tried = 0;
453: #endif
1.215 djm 454: authctxt.agent_fd = -1;
1.352 djm 455: pubkey_prepare(ssh, &authctxt);
1.291 djm 456: if (authctxt.method == NULL) {
1.331 djm 457: fatal_f("internal error: cannot send userauth none request");
1.291 djm 458: }
1.20 markus 459:
1.231 markus 460: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
461: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
462: (r = sshpkt_send(ssh)) != 0)
1.331 djm 463: fatal_fr(r, "send packet");
1.231 markus 464:
1.260 markus 465: ssh->authctxt = &authctxt;
1.231 markus 466: ssh_dispatch_init(ssh, &input_userauth_error);
1.370 ! djm 467: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, kex_input_ext_info);
1.231 markus 468: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.263 markus 469: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.303 djm 470: pubkey_cleanup(ssh);
1.368 djm 471: #ifdef GSSAPI
472: if (authctxt.gss_supported_mechs != NULL) {
473: u_int ms;
474:
475: gss_release_oid_set(&ms, &authctxt.gss_supported_mechs);
476: authctxt.gss_supported_mechs = NULL;
477: }
478: #endif
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.");
1.351 djm 485: if (ssh_packet_connection_is_on_socket(ssh)) {
486: verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
487: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
488: authctxt.method->name);
489: } else {
490: verbose("Authenticated to %s (via proxy) using \"%s\".", host,
491: authctxt.method->name);
492: }
1.20 markus 493: }
1.119 markus 494:
1.302 djm 495: static int
1.261 markus 496: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 497: {
498: int r;
499:
500: if (ssh_packet_remaining(ssh) > 0) {
501: char *reply;
502:
503: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
504: goto out;
505: debug2("service_accept: %s", reply);
506: free(reply);
507: } else {
508: debug2("buggy server: service_accept w/o service");
509: }
510: if ((r = sshpkt_get_end(ssh)) != 0)
511: goto out;
512: debug("SSH2_MSG_SERVICE_ACCEPT received");
513:
514: /* initial userauth request */
1.295 djm 515: userauth_none(ssh);
1.231 markus 516:
517: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
518: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
519: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
520: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
521: r = 0;
522: out:
523: return r;
524: }
525:
1.20 markus 526: void
1.295 djm 527: userauth(struct ssh *ssh, char *authlist)
1.51 markus 528: {
1.295 djm 529: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 530:
1.170 djm 531: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 532: authctxt->method->cleanup(ssh);
1.170 djm 533:
1.197 djm 534: free(authctxt->methoddata);
535: authctxt->methoddata = NULL;
1.51 markus 536: if (authlist == NULL) {
537: authlist = authctxt->authlist;
538: } else {
1.197 djm 539: free(authctxt->authlist);
1.51 markus 540: authctxt->authlist = authlist;
541: }
542: for (;;) {
543: Authmethod *method = authmethod_get(authlist);
544: if (method == NULL)
1.264 dtucker 545: fatal("%s@%s: Permission denied (%s).",
546: authctxt->server_user, authctxt->host, authlist);
1.51 markus 547: authctxt->method = method;
1.119 markus 548:
549: /* reset the per method handler */
1.278 markus 550: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 551: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
552:
553: /* and try new method */
1.295 djm 554: if (method->userauth(ssh) != 0) {
1.51 markus 555: debug2("we sent a %s packet, wait for reply", method->name);
556: break;
557: } else {
558: debug2("we did not send a packet, disable method");
559: method->enabled = NULL;
560: }
561: }
562: }
1.105 deraadt 563:
1.302 djm 564: static int
1.261 markus 565: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 566: {
1.331 djm 567: fatal_f("bad message during authentication: type %d", type);
1.218 markus 568: return 0;
1.35 markus 569: }
1.105 deraadt 570:
1.302 djm 571: static int
1.261 markus 572: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 573: {
1.295 djm 574: char *msg = NULL;
1.294 djm 575: size_t len;
576: int r;
1.126 deraadt 577:
1.331 djm 578: debug3_f("entering");
1.294 djm 579: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 580: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 581: goto out;
1.246 djm 582: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
583: fmprintf(stderr, "%s", msg);
1.294 djm 584: r = 0;
585: out:
1.246 djm 586: free(msg);
1.294 djm 587: return r;
1.20 markus 588: }
1.105 deraadt 589:
1.302 djm 590: static int
1.261 markus 591: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 592: {
1.260 markus 593: Authctxt *authctxt = ssh->authctxt;
1.172 djm 594:
1.20 markus 595: if (authctxt == NULL)
1.331 djm 596: fatal_f("no authentication context");
1.197 djm 597: free(authctxt->authlist);
598: authctxt->authlist = NULL;
1.172 djm 599: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 600: authctxt->method->cleanup(ssh);
1.197 djm 601: free(authctxt->methoddata);
602: authctxt->methoddata = NULL;
1.20 markus 603: authctxt->success = 1; /* break out */
1.370 ! djm 604: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, dispatch_protocol_error);
1.218 markus 605: return 0;
1.20 markus 606: }
1.105 deraadt 607:
1.302 djm 608: #if 0
609: static int
1.261 markus 610: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 611: {
1.260 markus 612: Authctxt *authctxt = ssh->authctxt;
1.172 djm 613:
614: if (authctxt == NULL)
1.331 djm 615: fatal_f("no authentication context");
1.172 djm 616:
617: fatal("Unexpected authentication success during %s.",
618: authctxt->method->name);
1.218 markus 619: return 0;
1.172 djm 620: }
1.302 djm 621: #endif
1.172 djm 622:
1.302 djm 623: static int
1.261 markus 624: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 625: {
1.260 markus 626: Authctxt *authctxt = ssh->authctxt;
1.20 markus 627: char *authlist = NULL;
1.278 markus 628: u_char partial;
1.20 markus 629:
630: if (authctxt == NULL)
631: fatal("input_userauth_failure: no authentication context");
632:
1.307 dtucker 633: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
634: sshpkt_get_u8(ssh, &partial) != 0 ||
635: sshpkt_get_end(ssh) != 0)
1.278 markus 636: goto out;
1.20 markus 637:
1.193 markus 638: if (partial != 0) {
1.351 djm 639: verbose("Authenticated using \"%s\" with partial success.",
640: authctxt->method->name);
1.193 markus 641: /* reset state */
1.251 djm 642: pubkey_reset(authctxt);
1.193 markus 643: }
1.109 markus 644: debug("Authentications that can continue: %s", authlist);
1.20 markus 645:
1.295 djm 646: userauth(ssh, authlist);
1.278 markus 647: authlist = NULL;
648: out:
649: free(authlist);
1.218 markus 650: return 0;
1.51 markus 651: }
1.169 djm 652:
1.287 djm 653: /*
654: * Format an identity for logging including filename, key type, fingerprint
655: * and location (agent, etc.). Caller must free.
656: */
657: static char *
658: format_identity(Identity *id)
659: {
660: char *fp = NULL, *ret = NULL;
1.309 djm 661: const char *note = "";
1.287 djm 662:
663: if (id->key != NULL) {
1.347 djm 664: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1.287 djm 665: SSH_FP_DEFAULT);
666: }
1.309 djm 667: if (id->key) {
668: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
669: note = " token";
1.311 markus 670: else if (sshkey_is_sk(id->key))
1.319 naddy 671: note = " authenticator";
1.309 djm 672: }
1.287 djm 673: xasprintf(&ret, "%s %s%s%s%s%s%s",
674: id->filename,
675: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
676: fp ? fp : "",
1.309 djm 677: id->userprovided ? " explicit" : "", note,
1.287 djm 678: id->agent_fd != -1 ? " agent" : "");
679: free(fp);
680: return ret;
681: }
682:
1.302 djm 683: static int
1.261 markus 684: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 685: {
1.260 markus 686: Authctxt *authctxt = ssh->authctxt;
1.259 markus 687: struct sshkey *key = NULL;
1.117 markus 688: Identity *id = NULL;
1.287 djm 689: int pktype, found = 0, sent = 0;
1.278 markus 690: size_t blen;
1.287 djm 691: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 692: u_char *pkblob = NULL;
693: int r;
1.51 markus 694:
695: if (authctxt == NULL)
696: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 697:
1.278 markus 698: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
699: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
700: (r = sshpkt_get_end(ssh)) != 0)
701: goto done;
1.51 markus 702:
1.278 markus 703: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 704: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 705: goto done;
706: }
1.278 markus 707: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 708: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 709: goto done;
710: }
711: if (key->type != pktype) {
712: error("input_userauth_pk_ok: type mismatch "
713: "for decoded key (received %d, expected %d)",
714: key->type, pktype);
715: goto done;
716: }
717:
1.127 markus 718: /*
719: * search keys in the reverse order, because last candidate has been
720: * moved to the end of the queue. this also avoids confusion by
721: * duplicate keys
722: */
1.136 henning 723: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 724: if (sshkey_equal(key, id->key)) {
1.287 djm 725: found = 1;
1.51 markus 726: break;
727: }
1.117 markus 728: }
1.287 djm 729: if (!found || id == NULL) {
730: fp = sshkey_fingerprint(key, options.fingerprint_hash,
731: SSH_FP_DEFAULT);
1.331 djm 732: error_f("server replied with unknown key: %s %s",
1.287 djm 733: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
734: goto done;
735: }
736: ident = format_identity(id);
737: debug("Server accepts key: %s", ident);
1.295 djm 738: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 739: r = 0;
740: done:
741: sshkey_free(key);
1.287 djm 742: free(ident);
743: free(fp);
1.197 djm 744: free(pkalg);
745: free(pkblob);
1.51 markus 746:
1.106 deraadt 747: /* try another method if we did not send a packet */
1.278 markus 748: if (r == 0 && sent == 0)
1.295 djm 749: userauth(ssh, NULL);
1.278 markus 750: return r;
1.20 markus 751: }
1.121 markus 752:
753: #ifdef GSSAPI
1.302 djm 754: static int
1.295 djm 755: userauth_gssapi(struct ssh *ssh)
1.121 markus 756: {
1.295 djm 757: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 758: Gssctxt *gssctxt = NULL;
759: OM_uint32 min;
1.278 markus 760: int r, ok = 0;
1.302 djm 761: gss_OID mech = NULL;
1.121 markus 762:
763: /* Try one GSSAPI method at a time, rather than sending them all at
764: * once. */
765:
1.302 djm 766: if (authctxt->gss_supported_mechs == NULL)
767: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 768:
1.302 djm 769: /* Check to see whether the mechanism is usable before we offer it */
770: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
771: !ok) {
772: mech = &authctxt->gss_supported_mechs->
773: elements[authctxt->mech_tried];
1.121 markus 774: /* My DER encoding requires length<128 */
1.302 djm 775: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
776: mech, authctxt->host)) {
1.121 markus 777: ok = 1; /* Mechanism works */
778: } else {
1.302 djm 779: authctxt->mech_tried++;
1.121 markus 780: }
781: }
782:
1.302 djm 783: if (!ok || mech == NULL)
1.139 djm 784: return 0;
1.121 markus 785:
786: authctxt->methoddata=(void *)gssctxt;
787:
1.278 markus 788: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
789: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
790: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
791: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
792: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 793: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 794: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 795: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
796: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 797: (r = sshpkt_send(ssh)) != 0)
1.331 djm 798: fatal_fr(r, "send packet");
1.278 markus 799:
800: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
801: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
802: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
803: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 804:
1.302 djm 805: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 806:
807: return 1;
808: }
809:
1.302 djm 810: static void
811: userauth_gssapi_cleanup(struct ssh *ssh)
812: {
813: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
814: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
815:
816: ssh_gssapi_delete_ctx(&gssctxt);
817: authctxt->methoddata = NULL;
818: }
819:
1.130 markus 820: static OM_uint32
1.262 djm 821: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 822: {
1.260 markus 823: Authctxt *authctxt = ssh->authctxt;
1.130 markus 824: Gssctxt *gssctxt = authctxt->methoddata;
825: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 826: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
827: gss_buffer_desc gssbuf;
1.132 markus 828: OM_uint32 status, ms, flags;
1.278 markus 829: int r;
1.133 djm 830:
1.130 markus 831: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 832: recv_tok, &send_tok, &flags);
1.130 markus 833:
834: if (send_tok.length > 0) {
1.278 markus 835: u_char type = GSS_ERROR(status) ?
836: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
837: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
838:
839: if ((r = sshpkt_start(ssh, type)) != 0 ||
840: (r = sshpkt_put_string(ssh, send_tok.value,
841: send_tok.length)) != 0 ||
842: (r = sshpkt_send(ssh)) != 0)
1.331 djm 843: fatal_fr(r, "send %u packet", type);
1.133 djm 844:
1.130 markus 845: gss_release_buffer(&ms, &send_tok);
846: }
1.133 djm 847:
1.130 markus 848: if (status == GSS_S_COMPLETE) {
1.132 markus 849: /* send either complete or MIC, depending on mechanism */
850: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 851: if ((r = sshpkt_start(ssh,
852: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
853: (r = sshpkt_send(ssh)) != 0)
1.331 djm 854: fatal_fr(r, "send completion");
1.132 markus 855: } else {
1.278 markus 856: struct sshbuf *b;
857:
858: if ((b = sshbuf_new()) == NULL)
1.331 djm 859: fatal_f("sshbuf_new failed");
1.278 markus 860: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 djm 861: authctxt->service, "gssapi-with-mic",
862: ssh->kex->session_id);
1.132 markus 863:
1.278 markus 864: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 865: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 866: gssbuf.length = sshbuf_len(b);
1.133 djm 867:
1.132 markus 868: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 869:
1.132 markus 870: if (!GSS_ERROR(status)) {
1.278 markus 871: if ((r = sshpkt_start(ssh,
872: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
873: (r = sshpkt_put_string(ssh, mic.value,
874: mic.length)) != 0 ||
875: (r = sshpkt_send(ssh)) != 0)
1.331 djm 876: fatal_fr(r, "send MIC");
1.132 markus 877: }
1.133 djm 878:
1.278 markus 879: sshbuf_free(b);
1.132 markus 880: gss_release_buffer(&ms, &mic);
1.133 djm 881: }
1.130 markus 882: }
1.133 djm 883:
1.130 markus 884: return status;
885: }
886:
1.302 djm 887: static int
1.261 markus 888: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 889: {
1.260 markus 890: Authctxt *authctxt = ssh->authctxt;
1.121 markus 891: Gssctxt *gssctxt;
1.278 markus 892: size_t oidlen;
893: u_char *oidv = NULL;
894: int r;
1.121 markus 895:
896: if (authctxt == NULL)
897: fatal("input_gssapi_response: no authentication context");
898: gssctxt = authctxt->methoddata;
899:
900: /* Setup our OID */
1.278 markus 901: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
902: goto done;
1.121 markus 903:
1.129 markus 904: if (oidlen <= 2 ||
905: oidv[0] != SSH_GSS_OIDTYPE ||
906: oidv[1] != oidlen - 2) {
907: debug("Badly encoded mechanism OID received");
1.296 djm 908: userauth(ssh, NULL);
1.278 markus 909: goto ok;
1.121 markus 910: }
1.129 markus 911:
912: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
913: fatal("Server returned different OID than expected");
1.121 markus 914:
1.278 markus 915: if ((r = sshpkt_get_end(ssh)) != 0)
916: goto done;
1.121 markus 917:
1.262 djm 918: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 919: /* Start again with next method on list */
920: debug("Trying to start again");
1.296 djm 921: userauth(ssh, NULL);
1.278 markus 922: goto ok;
1.121 markus 923: }
1.278 markus 924: ok:
925: r = 0;
926: done:
927: free(oidv);
928: return r;
1.121 markus 929: }
930:
1.302 djm 931: static int
1.261 markus 932: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 933: {
1.260 markus 934: Authctxt *authctxt = ssh->authctxt;
1.121 markus 935: gss_buffer_desc recv_tok;
1.278 markus 936: u_char *p = NULL;
937: size_t len;
1.130 markus 938: OM_uint32 status;
1.278 markus 939: int r;
1.121 markus 940:
941: if (authctxt == NULL)
942: fatal("input_gssapi_response: no authentication context");
943:
1.278 markus 944: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
945: (r = sshpkt_get_end(ssh)) != 0)
946: goto out;
1.121 markus 947:
1.278 markus 948: recv_tok.value = p;
949: recv_tok.length = len;
1.262 djm 950: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 951:
1.278 markus 952: /* Start again with the next method in the list */
1.121 markus 953: if (GSS_ERROR(status)) {
1.296 djm 954: userauth(ssh, NULL);
1.278 markus 955: /* ok */
1.121 markus 956: }
1.278 markus 957: r = 0;
958: out:
959: free(p);
960: return r;
1.121 markus 961: }
962:
1.302 djm 963: static int
1.261 markus 964: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 965: {
1.260 markus 966: Authctxt *authctxt = ssh->authctxt;
1.121 markus 967: Gssctxt *gssctxt;
968: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
969: gss_buffer_desc recv_tok;
1.194 djm 970: OM_uint32 ms;
1.278 markus 971: u_char *p = NULL;
972: size_t len;
973: int r;
1.121 markus 974:
975: if (authctxt == NULL)
976: fatal("input_gssapi_response: no authentication context");
977: gssctxt = authctxt->methoddata;
978:
1.278 markus 979: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
980: (r = sshpkt_get_end(ssh)) != 0) {
981: free(p);
982: return r;
983: }
1.121 markus 984:
985: /* Stick it into GSSAPI and see what it says */
1.278 markus 986: recv_tok.value = p;
987: recv_tok.length = len;
1.194 djm 988: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 989: &recv_tok, &send_tok, NULL);
1.278 markus 990: free(p);
1.121 markus 991: gss_release_buffer(&ms, &send_tok);
992:
993: /* Server will be returning a failed packet after this one */
1.220 djm 994: return 0;
1.121 markus 995: }
996:
1.302 djm 997: static int
1.261 markus 998: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 999: {
1.278 markus 1000: char *msg = NULL;
1001: char *lang = NULL;
1002: int r;
1.121 markus 1003:
1.278 markus 1004: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1005: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1006: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1007: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1008: goto out;
1009: r = sshpkt_get_end(ssh);
1.143 stevesk 1010: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1011: out:
1.197 djm 1012: free(msg);
1013: free(lang);
1.278 markus 1014: return r;
1.121 markus 1015: }
1016: #endif /* GSSAPI */
1.20 markus 1017:
1.302 djm 1018: static int
1.295 djm 1019: userauth_none(struct ssh *ssh)
1.23 markus 1020: {
1.295 djm 1021: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1022: int r;
1023:
1.23 markus 1024: /* initial userauth request */
1.278 markus 1025: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1026: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1027: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1028: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1029: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1030: fatal_fr(r, "send packet");
1.23 markus 1031: return 1;
1032: }
1033:
1.302 djm 1034: static int
1.295 djm 1035: userauth_passwd(struct ssh *ssh)
1.1 markus 1036: {
1.295 djm 1037: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1038: char *password, *prompt = NULL;
1.175 dtucker 1039: const char *host = options.host_key_alias ? options.host_key_alias :
1040: authctxt->host;
1.278 markus 1041: int r;
1.6 markus 1042:
1.292 djm 1043: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1044: return 0;
1.13 todd 1045:
1.292 djm 1046: if (authctxt->attempt_passwd != 1)
1.13 todd 1047: error("Permission denied, please try again.");
1.1 markus 1048:
1.290 djm 1049: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1050: password = read_passphrase(prompt, 0);
1.278 markus 1051: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1052: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1053: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1054: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1055: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1056: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1057: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1058: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1059: fatal_fr(r, "send packet");
1.99 markus 1060:
1.290 djm 1061: free(prompt);
1062: if (password != NULL)
1.278 markus 1063: freezero(password, strlen(password));
1064:
1065: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1066: &input_userauth_passwd_changereq);
1067:
1.1 markus 1068: return 1;
1069: }
1.169 djm 1070:
1.99 markus 1071: /*
1072: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1073: */
1.302 djm 1074: static int
1.261 markus 1075: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1076: {
1.260 markus 1077: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1078: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1079: char prompt[256];
1.252 djm 1080: const char *host;
1.278 markus 1081: int r;
1.99 markus 1082:
1083: debug2("input_userauth_passwd_changereq");
1084:
1085: if (authctxt == NULL)
1086: fatal("input_userauth_passwd_changereq: "
1087: "no authentication context");
1.252 djm 1088: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1089:
1.278 markus 1090: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1091: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1092: goto out;
1.99 markus 1093: if (strlen(info) > 0)
1.116 itojun 1094: logit("%s", info);
1.278 markus 1095: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1096: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1097: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1098: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1099: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1100: goto out;
1101:
1.104 deraadt 1102: snprintf(prompt, sizeof(prompt),
1.99 markus 1103: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1104: authctxt->server_user, host);
1.99 markus 1105: password = read_passphrase(prompt, 0);
1.278 markus 1106: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1107: goto out;
1108:
1109: freezero(password, strlen(password));
1.99 markus 1110: password = NULL;
1111: while (password == NULL) {
1.104 deraadt 1112: snprintf(prompt, sizeof(prompt),
1.99 markus 1113: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1114: authctxt->server_user, host);
1.99 markus 1115: password = read_passphrase(prompt, RP_ALLOW_EOF);
1116: if (password == NULL) {
1117: /* bail out */
1.278 markus 1118: r = 0;
1119: goto out;
1.99 markus 1120: }
1.104 deraadt 1121: snprintf(prompt, sizeof(prompt),
1.99 markus 1122: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1123: authctxt->server_user, host);
1.99 markus 1124: retype = read_passphrase(prompt, 0);
1125: if (strcmp(password, retype) != 0) {
1.278 markus 1126: freezero(password, strlen(password));
1.116 itojun 1127: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1128: password = NULL;
1129: }
1.278 markus 1130: freezero(retype, strlen(retype));
1.99 markus 1131: }
1.278 markus 1132: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1133: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1134: (r = sshpkt_send(ssh)) != 0)
1135: goto out;
1.104 deraadt 1136:
1.278 markus 1137: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1138: &input_userauth_passwd_changereq);
1.278 markus 1139: r = 0;
1140: out:
1141: if (password)
1142: freezero(password, strlen(password));
1143: free(info);
1144: free(lang);
1145: return r;
1.117 markus 1146: }
1147:
1.272 djm 1148: /*
1149: * Select an algorithm for publickey signatures.
1150: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1151: *
1152: * Call with ssh==NULL to ignore server-sig-algs extension list and
1153: * only attempt with the key's base signature type.
1154: */
1155: static char *
1156: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1157: {
1.274 djm 1158: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.348 djm 1159: const char *server_sig_algs;
1.231 markus 1160:
1.272 djm 1161: /*
1162: * The signature algorithm will only differ from the key algorithm
1163: * for RSA keys/certs and when the server advertises support for
1164: * newer (SHA2) algorithms.
1165: */
1166: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1167: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1168: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1169: /* Filter base key signature alg against our configuration */
1.279 markus 1170: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1171: options.pubkey_accepted_algos, NULL);
1.231 markus 1172: }
1173:
1.272 djm 1174: /*
1.348 djm 1175: * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1176: * fails to advertise it via SSH2_MSG_EXT_INFO.
1177: */
1178: server_sig_algs = ssh->kex->server_sig_algs;
1179: if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1180: server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1181:
1182: /*
1.272 djm 1183: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1184: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1185: * that also appears in the supported signature algorithms list from
1186: * the server.
1187: */
1.342 dtucker 1188: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1189: while ((cp = strsep(&allowed, ",")) != NULL) {
1190: if (sshkey_type_from_name(cp) != key->type)
1191: continue;
1.323 djm 1192: tmp = match_list(sshkey_sigalg_by_name(cp),
1.348 djm 1193: server_sig_algs, NULL);
1.274 djm 1194: if (tmp != NULL)
1195: alg = xstrdup(cp);
1196: free(tmp);
1.272 djm 1197: if (alg != NULL)
1198: break;
1.269 djm 1199: }
1.272 djm 1200: free(oallowed);
1201: return alg;
1.269 djm 1202: }
1203:
1.117 markus 1204: static int
1.214 djm 1205: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1206: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1207: {
1.309 djm 1208: struct sshkey *sign_key = NULL, *prv = NULL;
1.360 djm 1209: int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1210: struct notifier_ctx *notifier = NULL;
1.325 djm 1211: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1212:
1213: *sigp = NULL;
1214: *lenp = 0;
1.99 markus 1215:
1.272 djm 1216: /* The agent supports this key. */
1.269 djm 1217: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1218: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1219: data, datalen, alg, compat);
1.269 djm 1220: }
1.214 djm 1221:
1.117 markus 1222: /*
1.272 djm 1223: * We have already loaded the private key or the private key is
1224: * stored in external hardware.
1.117 markus 1225: */
1.255 djm 1226: if (id->key != NULL &&
1.272 djm 1227: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1228: sign_key = id->key;
1.360 djm 1229: is_agent = 1;
1.309 djm 1230: } else {
1231: /* Load the private key from the file. */
1232: if ((prv = load_identity_file(id)) == NULL)
1233: return SSH_ERR_KEY_NOT_FOUND;
1234: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1235: error_f("private key %s contents do not match public",
1.347 djm 1236: id->filename);
1.309 djm 1237: r = SSH_ERR_KEY_NOT_FOUND;
1238: goto out;
1239: }
1240: sign_key = prv;
1.360 djm 1241: }
1.341 djm 1242: retry_pin:
1.360 djm 1243: /* Prompt for touch for non-agent FIDO keys that request UP */
1244: if (!is_agent && sshkey_is_sk(sign_key) &&
1245: (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1246: /* XXX should batch mode just skip these? */
1247: if ((fp = sshkey_fingerprint(sign_key,
1248: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1249: fatal_f("fingerprint failed");
1250: notifier = notify_start(options.batch_mode,
1251: "Confirm user presence for key %s %s",
1252: sshkey_type(sign_key), fp);
1253: free(fp);
1.272 djm 1254: }
1.310 djm 1255: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1256: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1257: debug_fr(r, "sshkey_sign");
1.360 djm 1258: if (!retried && pin == NULL && !is_agent &&
1259: sshkey_is_sk(sign_key) &&
1.341 djm 1260: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1261: notify_complete(notifier, NULL);
1262: notifier = NULL;
1.360 djm 1263: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1264: sshkey_type(sign_key), id->filename);
1265: pin = read_passphrase(prompt, 0);
1.341 djm 1266: retried = 1;
1267: goto retry_pin;
1268: }
1.309 djm 1269: goto out;
1270: }
1.341 djm 1271:
1.309 djm 1272: /*
1273: * PKCS#11 tokens may not support all signature algorithms,
1274: * so check what we get back.
1275: */
1276: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1277: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1278: goto out;
1.265 djm 1279: }
1.309 djm 1280: /* success */
1281: r = 0;
1282: out:
1.325 djm 1283: free(prompt);
1284: if (pin != NULL)
1285: freezero(pin, strlen(pin));
1.341 djm 1286: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1287: sshkey_free(prv);
1.269 djm 1288: return r;
1.51 markus 1289: }
1290:
1.76 itojun 1291: static int
1.255 djm 1292: id_filename_matches(Identity *id, Identity *private_id)
1293: {
1.356 djm 1294: static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
1.255 djm 1295: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1296: size_t i, slen;
1297:
1298: if (strcmp(id->filename, private_id->filename) == 0)
1299: return 1;
1300: for (i = 0; suffixes[i]; i++) {
1301: slen = strlen(suffixes[i]);
1302: if (len > slen && plen == len - slen &&
1303: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1304: memcmp(id->filename, private_id->filename, plen) == 0)
1305: return 1;
1306: }
1307: return 0;
1308: }
1309:
1310: static int
1.295 djm 1311: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1312: {
1.295 djm 1313: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1314: struct sshbuf *b = NULL;
1315: Identity *private_id, *sign_id = NULL;
1316: u_char *signature = NULL;
1317: size_t slen = 0, skip = 0;
1318: int r, fallback_sigtype, sent = 0;
1319: char *alg = NULL, *fp = NULL;
1.353 djm 1320: const char *loc = "", *method = "publickey";
1.354 djm 1321: int hostbound = 0;
1.353 djm 1322:
1323: /* prefer host-bound pubkey signatures if supported by server */
1.354 djm 1324: if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
1325: (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
1326: hostbound = 1;
1.353 djm 1327: method = "publickey-hostbound-v00@openssh.com";
1.354 djm 1328: }
1.1 markus 1329:
1.222 djm 1330: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1331: SSH_FP_DEFAULT)) == NULL)
1332: return 0;
1.51 markus 1333:
1.354 djm 1334: debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
1.1 markus 1335:
1.227 djm 1336: /*
1337: * If the key is an certificate, try to find a matching private key
1338: * and use it to complete the signature.
1.241 djm 1339: * If no such private key exists, fall back to trying the certificate
1340: * key itself in case it has a private half already loaded.
1.272 djm 1341: * This will try to set sign_id to the private key that will perform
1342: * the signature.
1.227 djm 1343: */
1.272 djm 1344: if (sshkey_is_cert(id->key)) {
1.227 djm 1345: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1346: if (sshkey_equal_public(id->key, private_id->key) &&
1347: id->key->type != private_id->key->type) {
1.272 djm 1348: sign_id = private_id;
1.227 djm 1349: break;
1350: }
1351: }
1.255 djm 1352: /*
1353: * Exact key matches are preferred, but also allow
1354: * filename matches for non-PKCS#11/agent keys that
1355: * didn't load public keys. This supports the case
1356: * of keeping just a private key file and public
1357: * certificate on disk.
1358: */
1.272 djm 1359: if (sign_id == NULL &&
1360: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1361: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1362: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1363: if (private_id->key == NULL &&
1364: id_filename_matches(id, private_id)) {
1.272 djm 1365: sign_id = private_id;
1.255 djm 1366: break;
1367: }
1368: }
1369: }
1.272 djm 1370: if (sign_id != NULL) {
1.331 djm 1371: debug2_f("using private key \"%s\"%s for "
1.349 djm 1372: "certificate", sign_id->filename,
1373: sign_id->agent_fd != -1 ? " from agent" : "");
1.227 djm 1374: } else {
1.331 djm 1375: debug_f("no separate private key for certificate "
1376: "\"%s\"", id->filename);
1.227 djm 1377: }
1378: }
1379:
1.272 djm 1380: /*
1381: * If the above didn't select another identity to do the signing
1382: * then default to the one we started with.
1383: */
1384: if (sign_id == NULL)
1385: sign_id = id;
1386:
1387: /* assemble and sign data */
1388: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1389: free(alg);
1390: slen = 0;
1391: signature = NULL;
1392: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1393: id->key)) == NULL) {
1.331 djm 1394: error_f("no mutual signature supported");
1.272 djm 1395: goto out;
1396: }
1.331 djm 1397: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1398:
1399: sshbuf_free(b);
1400: if ((b = sshbuf_new()) == NULL)
1.331 djm 1401: fatal_f("sshbuf_new failed");
1.345 djm 1402: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 djm 1403: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1404: fatal_fr(r, "sshbuf_putb");
1.272 djm 1405: } else {
1.346 djm 1406: if ((r = sshbuf_put_stringb(b,
1407: ssh->kex->session_id)) != 0)
1408: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1409: }
1.278 markus 1410: skip = sshbuf_len(b);
1.272 djm 1411: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1412: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1413: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.353 djm 1414: (r = sshbuf_put_cstring(b, method)) != 0 ||
1.272 djm 1415: (r = sshbuf_put_u8(b, 1)) != 0 ||
1416: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1417: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1418: fatal_fr(r, "assemble signed data");
1.272 djm 1419: }
1.354 djm 1420: if (hostbound) {
1.353 djm 1421: if (ssh->kex->initial_hostkey == NULL) {
1422: fatal_f("internal error: initial hostkey "
1423: "not recorded");
1424: }
1425: if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
1426: fatal_fr(r, "assemble %s hostkey", method);
1427: }
1.272 djm 1428: /* generate signature */
1429: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1430: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1431: if (r == 0)
1432: break;
1433: else if (r == SSH_ERR_KEY_NOT_FOUND)
1434: goto out; /* soft failure */
1435: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1436: !fallback_sigtype) {
1437: if (sign_id->agent_fd != -1)
1438: loc = "agent ";
1439: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1440: loc = "token ";
1441: logit("%skey %s %s returned incorrect signature type",
1442: loc, sshkey_type(id->key), fp);
1443: continue;
1444: }
1.331 djm 1445: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1446: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1447: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1448: goto out;
1.17 markus 1449: }
1.272 djm 1450: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1451: fatal_f("no signature");
1.51 markus 1452:
1.1 markus 1453: /* append signature */
1.272 djm 1454: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1455: fatal_fr(r, "append signature");
1.1 markus 1456:
1.272 djm 1457: #ifdef DEBUG_PK
1458: sshbuf_dump(b, stderr);
1459: #endif
1.1 markus 1460: /* skip session id and packet type */
1.272 djm 1461: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1462: fatal_fr(r, "consume");
1.1 markus 1463:
1464: /* put remaining data from buffer into packet */
1.272 djm 1465: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1466: (r = sshpkt_putb(ssh, b)) != 0 ||
1467: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1468: fatal_fr(r, "enqueue request");
1.272 djm 1469:
1470: /* success */
1471: sent = 1;
1.17 markus 1472:
1.272 djm 1473: out:
1474: free(fp);
1475: free(alg);
1476: sshbuf_free(b);
1477: freezero(signature, slen);
1478: return sent;
1.16 markus 1479: }
1480:
1.76 itojun 1481: static int
1.295 djm 1482: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1483: {
1.295 djm 1484: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1485: u_char *blob = NULL;
1486: char *alg = NULL;
1.278 markus 1487: size_t bloblen;
1488: u_int have_sig = 0;
1489: int sent = 0, r;
1.20 markus 1490:
1.272 djm 1491: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1492: debug_f("no mutual signature algorithm");
1.272 djm 1493: goto out;
1494: }
1.16 markus 1495:
1.278 markus 1496: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1497: /* we cannot handle this key */
1.331 djm 1498: debug3_f("cannot handle key");
1.272 djm 1499: goto out;
1.16 markus 1500: }
1.51 markus 1501: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1502: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1503:
1.278 markus 1504: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1505: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1506: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1507: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1508: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1509: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1510: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1511: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1512: fatal_fr(r, "send packet");
1.272 djm 1513: sent = 1;
1.278 markus 1514:
1515: out:
1.272 djm 1516: free(alg);
1.197 djm 1517: free(blob);
1.272 djm 1518: return sent;
1.51 markus 1519: }
1520:
1.259 markus 1521: static struct sshkey *
1.229 jcs 1522: load_identity_file(Identity *id)
1.51 markus 1523: {
1.259 markus 1524: struct sshkey *private = NULL;
1.229 jcs 1525: char prompt[300], *passphrase, *comment;
1.308 dtucker 1526: int r, quit = 0, i;
1.52 markus 1527: struct stat st;
1.16 markus 1528:
1.306 deraadt 1529: if (stat(id->filename, &st) == -1) {
1.330 djm 1530: do_log2(id->userprovided ?
1531: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1532: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1533: return NULL;
1534: }
1.214 djm 1535: snprintf(prompt, sizeof prompt,
1.229 jcs 1536: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1537: for (i = 0; i <= options.number_of_password_prompts; i++) {
1538: if (i == 0)
1539: passphrase = "";
1540: else {
1.20 markus 1541: passphrase = read_passphrase(prompt, 0);
1.214 djm 1542: if (*passphrase == '\0') {
1.20 markus 1543: debug2("no passphrase given, try next key");
1.214 djm 1544: free(passphrase);
1545: break;
1546: }
1547: }
1.229 jcs 1548: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1549: passphrase, &private, &comment))) {
1.214 djm 1550: case 0:
1551: break;
1552: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1553: if (options.batch_mode) {
1554: quit = 1;
1555: break;
1556: }
1.215 djm 1557: if (i != 0)
1558: debug2("bad passphrase given, try again...");
1.214 djm 1559: break;
1560: case SSH_ERR_SYSTEM_ERROR:
1561: if (errno == ENOENT) {
1.331 djm 1562: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1563: quit = 1;
1.214 djm 1564: break;
1.20 markus 1565: }
1.214 djm 1566: /* FALLTHROUGH */
1567: default:
1.331 djm 1568: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1569: quit = 1;
1570: break;
1571: }
1.311 markus 1572: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1573: options.sk_provider == NULL) {
1.319 naddy 1574: debug("key \"%s\" is an authenticator-hosted key, "
1575: "but no provider specified", id->filename);
1.309 djm 1576: sshkey_free(private);
1577: private = NULL;
1578: quit = 1;
1579: }
1.361 djm 1580: if (!quit && (r = sshkey_check_rsa_length(private,
1581: options.required_rsa_size)) != 0) {
1582: debug_fr(r, "Skipping key %s", id->filename);
1583: sshkey_free(private);
1584: private = NULL;
1585: quit = 1;
1586: }
1.230 djm 1587: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1588: !(id->key && id->isprivate))
1589: maybe_add_key_to_agent(id->filename, private, comment,
1590: passphrase);
1.278 markus 1591: if (i > 0)
1592: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1593: free(comment);
1.214 djm 1594: if (private != NULL || quit)
1595: break;
1.16 markus 1596: }
1.51 markus 1597: return private;
1598: }
1599:
1.272 djm 1600: static int
1601: key_type_allowed_by_config(struct sshkey *key)
1602: {
1603: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1604: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1605: return 1;
1606:
1607: /* RSA keys/certs might be allowed by alternate signature types */
1608: switch (key->type) {
1609: case KEY_RSA:
1610: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1611: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1612: return 1;
1613: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1614: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1615: return 1;
1616: break;
1617: case KEY_RSA_CERT:
1618: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1619: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1620: return 1;
1621: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1622: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1623: return 1;
1624: break;
1625: }
1626: return 0;
1627: }
1628:
1.352 djm 1629: /* obtain a list of keys from the agent */
1630: static int
1631: get_agent_identities(struct ssh *ssh, int *agent_fdp,
1632: struct ssh_identitylist **idlistp)
1633: {
1634: int r, agent_fd;
1635: struct ssh_identitylist *idlist;
1636:
1637: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1638: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1639: debug_fr(r, "ssh_get_authentication_socket");
1640: return r;
1641: }
1642: if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
1643: ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
1644: debug_f("bound agent to hostkey");
1645: else
1646: debug2_fr(r, "ssh_agent_bind_hostkey");
1647:
1648: if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1649: debug_fr(r, "ssh_fetch_identitylist");
1650: close(agent_fd);
1651: return r;
1652: }
1653: /* success */
1654: *agent_fdp = agent_fd;
1655: *idlistp = idlist;
1656: debug_f("agent returned %zu keys", idlist->nkeys);
1657: return 0;
1658: }
1.272 djm 1659:
1.117 markus 1660: /*
1661: * try keys in the following order:
1.332 djm 1662: * 1. certificates listed in the config file
1663: * 2. other input certificates
1.227 djm 1664: * 3. agent keys that are found in the config file
1665: * 4. other agent keys
1666: * 5. keys that are only listed in the config file
1.117 markus 1667: */
1668: static void
1.352 djm 1669: pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
1.51 markus 1670: {
1.214 djm 1671: struct identity *id, *id2, *tmp;
1672: struct idlist agent, files, *preferred;
1673: struct sshkey *key;
1.230 djm 1674: int agent_fd = -1, i, r, found;
1.214 djm 1675: size_t j;
1676: struct ssh_identitylist *idlist;
1.287 djm 1677: char *ident;
1.51 markus 1678:
1.117 markus 1679: TAILQ_INIT(&agent); /* keys from the agent */
1680: TAILQ_INIT(&files); /* keys from the config file */
1681: preferred = &authctxt->keys;
1682: TAILQ_INIT(preferred); /* preferred order of keys */
1683:
1.190 djm 1684: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1685: for (i = 0; i < options.num_identity_files; i++) {
1686: key = options.identity_keys[i];
1.309 djm 1687: if (key && key->cert &&
1688: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1689: debug_f("ignoring certificate %s: not a user "
1690: "certificate", options.identity_files[i]);
1.309 djm 1691: continue;
1692: }
1.311 markus 1693: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1694: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1695: "SecurityKeyProvider has been specified",
1.331 djm 1696: options.identity_files[i]);
1.117 markus 1697: continue;
1.309 djm 1698: }
1.117 markus 1699: options.identity_keys[i] = NULL;
1.150 djm 1700: id = xcalloc(1, sizeof(*id));
1.230 djm 1701: id->agent_fd = -1;
1.117 markus 1702: id->key = key;
1703: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1704: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1705: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1706: }
1.227 djm 1707: /* list of certificates specified by user */
1708: for (i = 0; i < options.num_certificate_files; i++) {
1709: key = options.certificates[i];
1.278 markus 1710: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1711: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1712: debug_f("ignoring certificate %s: not a user "
1713: "certificate", options.identity_files[i]);
1.227 djm 1714: continue;
1.309 djm 1715: }
1.311 markus 1716: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1717: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1718: "certificate %s as no "
1.309 djm 1719: "SecurityKeyProvider has been specified",
1.331 djm 1720: options.identity_files[i]);
1.309 djm 1721: continue;
1722: }
1.227 djm 1723: id = xcalloc(1, sizeof(*id));
1.230 djm 1724: id->agent_fd = -1;
1.227 djm 1725: id->key = key;
1726: id->filename = xstrdup(options.certificate_files[i]);
1727: id->userprovided = options.certificate_file_userprovided[i];
1728: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1729: }
1730: /* list of keys supported by the agent */
1.352 djm 1731: if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
1.214 djm 1732: for (j = 0; j < idlist->nkeys; j++) {
1.361 djm 1733: if ((r = sshkey_check_rsa_length(idlist->keys[j],
1734: options.required_rsa_size)) != 0) {
1735: debug_fr(r, "ignoring %s agent key",
1736: sshkey_ssh_name(idlist->keys[j]));
1737: continue;
1738: }
1.117 markus 1739: found = 0;
1740: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1741: /*
1742: * agent keys from the config file are
1743: * preferred
1744: */
1745: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1746: TAILQ_REMOVE(&files, id, next);
1747: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1748: id->agent_fd = agent_fd;
1.117 markus 1749: found = 1;
1750: break;
1751: }
1752: }
1.135 markus 1753: if (!found && !options.identities_only) {
1.150 djm 1754: id = xcalloc(1, sizeof(*id));
1.214 djm 1755: /* XXX "steals" key/comment from idlist */
1756: id->key = idlist->keys[j];
1757: id->filename = idlist->comments[j];
1758: idlist->keys[j] = NULL;
1759: idlist->comments[j] = NULL;
1760: id->agent_fd = agent_fd;
1.117 markus 1761: TAILQ_INSERT_TAIL(&agent, id, next);
1762: }
1763: }
1.214 djm 1764: ssh_free_identitylist(idlist);
1.117 markus 1765: /* append remaining agent keys */
1.324 bket 1766: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1767: authctxt->agent_fd = agent_fd;
1.244 djm 1768: }
1769: /* Prefer PKCS11 keys that are explicitly listed */
1770: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1771: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1772: continue;
1773: found = 0;
1774: TAILQ_FOREACH(id2, &files, next) {
1775: if (id2->key == NULL ||
1.321 djm 1776: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1777: continue;
1778: if (sshkey_equal(id->key, id2->key)) {
1779: TAILQ_REMOVE(&files, id, next);
1780: TAILQ_INSERT_TAIL(preferred, id, next);
1781: found = 1;
1782: break;
1783: }
1784: }
1785: /* If IdentitiesOnly set and key not found then don't use it */
1786: if (!found && options.identities_only) {
1787: TAILQ_REMOVE(&files, id, next);
1.278 markus 1788: freezero(id, sizeof(*id));
1.244 djm 1789: }
1.117 markus 1790: }
1791: /* append remaining keys from the config file */
1.324 bket 1792: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1793: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1794: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1795: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1796: debug("Skipping %s key %s - "
1.342 dtucker 1797: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1798: sshkey_ssh_name(id->key), id->filename);
1799: TAILQ_REMOVE(preferred, id, next);
1800: sshkey_free(id->key);
1801: free(id->filename);
1802: memset(id, 0, sizeof(*id));
1803: continue;
1804: }
1.117 markus 1805: }
1.287 djm 1806: /* List the keys we plan on using */
1807: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1808: ident = format_identity(id);
1809: debug("Will attempt key: %s", ident);
1810: free(ident);
1811: }
1.331 djm 1812: debug2_f("done");
1.17 markus 1813: }
1814:
1.117 markus 1815: static void
1.303 djm 1816: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1817: {
1.302 djm 1818: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1819: Identity *id;
1.51 markus 1820:
1.289 djm 1821: if (authctxt->agent_fd != -1) {
1.214 djm 1822: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1823: authctxt->agent_fd = -1;
1824: }
1.117 markus 1825: for (id = TAILQ_FIRST(&authctxt->keys); id;
1826: id = TAILQ_FIRST(&authctxt->keys)) {
1827: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1828: sshkey_free(id->key);
1.197 djm 1829: free(id->filename);
1830: free(id);
1.117 markus 1831: }
1.1 markus 1832: }
1833:
1.251 djm 1834: static void
1835: pubkey_reset(Authctxt *authctxt)
1836: {
1837: Identity *id;
1838:
1839: TAILQ_FOREACH(id, &authctxt->keys, next)
1840: id->tried = 0;
1841: }
1842:
1.225 markus 1843: static int
1.295 djm 1844: userauth_pubkey(struct ssh *ssh)
1.20 markus 1845: {
1.295 djm 1846: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1847: Identity *id;
1.20 markus 1848: int sent = 0;
1.287 djm 1849: char *ident;
1.20 markus 1850:
1.117 markus 1851: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1852: if (id->tried++)
1853: return (0);
1.127 markus 1854: /* move key to the end of the queue */
1.117 markus 1855: TAILQ_REMOVE(&authctxt->keys, id, next);
1856: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1857: /*
1858: * send a test message if we have the public key. for
1859: * encrypted keys we cannot do this and have to load the
1860: * private key instead
1861: */
1.200 djm 1862: if (id->key != NULL) {
1.367 dtucker 1863: ident = format_identity(id);
1864: debug("Offering public key: %s", ident);
1865: free(ident);
1866: sent = send_pubkey_test(ssh, id);
1.200 djm 1867: } else {
1.117 markus 1868: debug("Trying private key: %s", id->filename);
1.229 jcs 1869: id->key = load_identity_file(id);
1.117 markus 1870: if (id->key != NULL) {
1.362 dtucker 1871: if (id->key != NULL) {
1.225 markus 1872: id->isprivate = 1;
1.295 djm 1873: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1874: }
1.278 markus 1875: sshkey_free(id->key);
1.117 markus 1876: id->key = NULL;
1.251 djm 1877: id->isprivate = 0;
1.51 markus 1878: }
1879: }
1.117 markus 1880: if (sent)
1881: return (sent);
1.28 markus 1882: }
1.117 markus 1883: return (0);
1.20 markus 1884: }
1885:
1.23 markus 1886: /*
1887: * Send userauth request message specifying keyboard-interactive method.
1888: */
1.302 djm 1889: static int
1.295 djm 1890: userauth_kbdint(struct ssh *ssh)
1.23 markus 1891: {
1.295 djm 1892: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1893: int r;
1.23 markus 1894:
1.292 djm 1895: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1896: return 0;
1.82 markus 1897: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1898: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1899: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1900: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1901: return 0;
1902: }
1.23 markus 1903:
1904: debug2("userauth_kbdint");
1.278 markus 1905: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1906: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1907: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1908: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1909: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1910: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1911: options.kbd_interactive_devices : "")) != 0 ||
1912: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1913: fatal_fr(r, "send packet");
1.23 markus 1914:
1.278 markus 1915: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1916: return 1;
1917: }
1918:
1919: /*
1.46 markus 1920: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1921: */
1.302 djm 1922: static int
1.261 markus 1923: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1924: {
1.260 markus 1925: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1926: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1927: char *display_prompt = NULL, *response = NULL;
1.278 markus 1928: u_char echo = 0;
1.32 markus 1929: u_int num_prompts, i;
1.278 markus 1930: int r;
1.23 markus 1931:
1.335 djm 1932: debug2_f("entering");
1.23 markus 1933:
1934: if (authctxt == NULL)
1.335 djm 1935: fatal_f("no authentication context");
1.82 markus 1936:
1937: authctxt->info_req_seen = 1;
1.23 markus 1938:
1.278 markus 1939: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1940: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1941: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1942: goto out;
1.23 markus 1943: if (strlen(name) > 0)
1.116 itojun 1944: logit("%s", name);
1.23 markus 1945: if (strlen(inst) > 0)
1.116 itojun 1946: logit("%s", inst);
1.23 markus 1947:
1.278 markus 1948: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1949: goto out;
1.23 markus 1950: /*
1951: * Begin to build info response packet based on prompts requested.
1952: * We commit to providing the correct number of responses, so if
1953: * further on we run into a problem that prevents this, we have to
1954: * be sure and clean this up and send a correct error response.
1955: */
1.278 markus 1956: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1957: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1958: goto out;
1.23 markus 1959:
1.335 djm 1960: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1961: for (i = 0; i < num_prompts; i++) {
1.278 markus 1962: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1963: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1964: goto out;
1.336 djm 1965: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1966: authctxt->server_user, options.host_key_alias ?
1.336 djm 1967: options.host_key_alias : authctxt->host, prompt) == -1)
1968: fatal_f("asmprintf failed");
1.335 djm 1969: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1970: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1971: goto out;
1972: freezero(response, strlen(response));
1.197 djm 1973: free(prompt);
1.335 djm 1974: free(display_prompt);
1975: display_prompt = response = prompt = NULL;
1.23 markus 1976: }
1.278 markus 1977: /* done with parsing incoming message. */
1978: if ((r = sshpkt_get_end(ssh)) != 0 ||
1979: (r = sshpkt_add_padding(ssh, 64)) != 0)
1980: goto out;
1981: r = sshpkt_send(ssh);
1982: out:
1983: if (response)
1984: freezero(response, strlen(response));
1985: free(prompt);
1.335 djm 1986: free(display_prompt);
1.278 markus 1987: free(name);
1988: free(inst);
1989: free(lang);
1990: return r;
1.68 markus 1991: }
1992:
1.100 markus 1993: static int
1.294 djm 1994: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 1995: const u_char *data, size_t datalen)
1.100 markus 1996: {
1.223 djm 1997: struct sshbuf *b;
1.101 markus 1998: struct stat st;
1.100 markus 1999: pid_t pid;
1.304 deraadt 2000: int r, to[2], from[2], status;
1.295 djm 2001: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 2002: u_char rversion = 0, version = 2;
2003: void (*osigchld)(int);
1.100 markus 2004:
1.223 djm 2005: *sigp = NULL;
2006: *lenp = 0;
1.100 markus 2007:
1.306 deraadt 2008: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 2009: error_f("not installed: %s", strerror(errno));
1.223 djm 2010: return -1;
2011: }
2012: if (fflush(stdout) != 0) {
1.331 djm 2013: error_f("fflush: %s", strerror(errno));
1.101 markus 2014: return -1;
2015: }
1.306 deraadt 2016: if (pipe(to) == -1) {
1.331 djm 2017: error_f("pipe: %s", strerror(errno));
1.100 markus 2018: return -1;
2019: }
1.306 deraadt 2020: if (pipe(from) == -1) {
1.331 djm 2021: error_f("pipe: %s", strerror(errno));
1.100 markus 2022: return -1;
2023: }
1.306 deraadt 2024: if ((pid = fork()) == -1) {
1.331 djm 2025: error_f("fork: %s", strerror(errno));
1.100 markus 2026: return -1;
2027: }
1.317 dtucker 2028: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 2029: if (pid == 0) {
2030: close(from[0]);
1.306 deraadt 2031: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2032: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2033: close(to[1]);
1.306 deraadt 2034: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2035: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2036: close(from[1]);
2037: close(to[0]);
1.304 deraadt 2038:
1.306 deraadt 2039: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2040: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2041: sock = STDERR_FILENO + 1;
1.363 dtucker 2042: if (fcntl(sock, F_SETFD, 0) == -1) /* keep the socket on exec */
2043: debug3_f("fcntl F_SETFD: %s", strerror(errno));
1.223 djm 2044: closefrom(sock + 1);
1.304 deraadt 2045:
1.331 djm 2046: debug3_f("[child] pid=%ld, exec %s",
2047: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2048: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2049: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2050: strerror(errno));
2051: }
2052: close(from[1]);
2053: close(to[0]);
1.305 djm 2054: sock = STDERR_FILENO + 1;
1.100 markus 2055:
1.223 djm 2056: if ((b = sshbuf_new()) == NULL)
1.331 djm 2057: fatal_f("sshbuf_new failed");
1.223 djm 2058: /* send # of sock, data to be signed */
1.253 djm 2059: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2060: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2061: fatal_fr(r, "buffer error");
1.223 djm 2062: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2063: fatal_f("couldn't send request");
1.223 djm 2064: sshbuf_reset(b);
2065: r = ssh_msg_recv(from[0], b);
1.101 markus 2066: close(from[0]);
2067: close(to[1]);
1.223 djm 2068: if (r < 0) {
1.331 djm 2069: error_f("no reply");
1.223 djm 2070: goto fail;
2071: }
1.101 markus 2072:
1.223 djm 2073: errno = 0;
1.306 deraadt 2074: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2075: if (errno != EINTR) {
1.331 djm 2076: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2077: goto fail;
2078: }
2079: }
2080: if (!WIFEXITED(status)) {
1.331 djm 2081: error_f("exited abnormally");
1.223 djm 2082: goto fail;
2083: }
2084: if (WEXITSTATUS(status) != 0) {
1.331 djm 2085: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2086: goto fail;
2087: }
2088: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2089: error_fr(r, "buffer error");
1.223 djm 2090: goto fail;
2091: }
2092: if (rversion != version) {
1.331 djm 2093: error_f("bad version");
1.223 djm 2094: goto fail;
2095: }
2096: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2097: error_fr(r, "buffer error");
1.223 djm 2098: fail:
1.317 dtucker 2099: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2100: sshbuf_free(b);
1.100 markus 2101: return -1;
2102: }
1.317 dtucker 2103: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2104: sshbuf_free(b);
1.100 markus 2105:
2106: return 0;
2107: }
2108:
1.302 djm 2109: static int
1.295 djm 2110: userauth_hostbased(struct ssh *ssh)
1.68 markus 2111: {
1.295 djm 2112: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2113: struct sshkey *private = NULL;
2114: struct sshbuf *b = NULL;
2115: u_char *sig = NULL, *keyblob = NULL;
2116: char *fp = NULL, *chost = NULL, *lname = NULL;
2117: size_t siglen = 0, keylen = 0;
2118: int i, r, success = 0;
2119:
2120: if (authctxt->ktypes == NULL) {
1.344 dtucker 2121: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2122: authctxt->ktypes = authctxt->oktypes;
2123: }
1.213 djm 2124:
1.223 djm 2125: /*
1.344 dtucker 2126: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2127: * trying each hostkey that matches the type in turn.
2128: */
2129: for (;;) {
2130: if (authctxt->active_ktype == NULL)
2131: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2132: if (authctxt->active_ktype == NULL ||
2133: *authctxt->active_ktype == '\0')
2134: break;
1.331 djm 2135: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2136:
1.223 djm 2137: /* check for a useful key */
2138: private = NULL;
2139: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2140: if (authctxt->sensitive->keys[i] == NULL ||
2141: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2142: continue;
1.355 djm 2143: if (!sshkey_match_keyname_to_sigalgs(
1.223 djm 2144: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.355 djm 2145: authctxt->active_ktype))
1.223 djm 2146: continue;
1.68 markus 2147: /* we take and free the key */
1.223 djm 2148: private = authctxt->sensitive->keys[i];
2149: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2150: break;
2151: }
1.223 djm 2152: /* Found one */
2153: if (private != NULL)
2154: break;
2155: /* No more keys of this type; advance */
2156: authctxt->active_ktype = NULL;
1.68 markus 2157: }
1.223 djm 2158: if (private == NULL) {
2159: free(authctxt->oktypes);
2160: authctxt->oktypes = authctxt->ktypes = NULL;
2161: authctxt->active_ktype = NULL;
1.109 markus 2162: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2163: goto out;
1.68 markus 2164: }
1.211 djm 2165:
1.223 djm 2166: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2167: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2168: error_f("sshkey_fingerprint failed");
1.223 djm 2169: goto out;
1.68 markus 2170: }
1.355 djm 2171: debug_f("trying hostkey %s %s using sigalg %s",
2172: sshkey_ssh_name(private), fp, authctxt->active_ktype);
1.211 djm 2173:
1.84 markus 2174: /* figure out a name for the client host */
1.295 djm 2175: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2176: if (lname == NULL) {
1.331 djm 2177: error_f("cannot get local ipaddr/name");
1.223 djm 2178: goto out;
1.84 markus 2179: }
1.223 djm 2180:
2181: /* XXX sshbuf_put_stringf? */
2182: xasprintf(&chost, "%s.", lname);
1.331 djm 2183: debug2_f("chost %s", chost);
1.84 markus 2184:
1.68 markus 2185: /* construct data */
1.223 djm 2186: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2187: error_f("sshbuf_new failed");
1.223 djm 2188: goto out;
2189: }
2190: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2191: error_fr(r, "sshkey_to_blob");
1.223 djm 2192: goto out;
2193: }
1.346 djm 2194: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2195: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2196: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2197: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2198: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2199: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2200: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2201: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2202: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2203: error_fr(r, "buffer error");
1.223 djm 2204: goto out;
2205: }
2206:
1.68 markus 2207: #ifdef DEBUG_PK
1.223 djm 2208: sshbuf_dump(b, stderr);
1.68 markus 2209: #endif
1.294 djm 2210: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2211: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2212: error("sign using hostkey %s %s failed",
2213: sshkey_ssh_name(private), fp);
2214: goto out;
2215: }
2216: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2217: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2218: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2219: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2220: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2221: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2222: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2223: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2224: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2225: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2226: error_fr(r, "packet error");
1.223 djm 2227: goto out;
2228: }
2229: success = 1;
2230:
2231: out:
1.278 markus 2232: if (sig != NULL)
2233: freezero(sig, siglen);
1.223 djm 2234: free(keyblob);
2235: free(lname);
2236: free(fp);
1.197 djm 2237: free(chost);
1.223 djm 2238: sshkey_free(private);
2239: sshbuf_free(b);
1.68 markus 2240:
1.223 djm 2241: return success;
1.23 markus 2242: }
1.170 djm 2243:
1.20 markus 2244: /* find auth method */
2245:
2246: /*
2247: * given auth method name, if configurable options permit this method fill
2248: * in auth_ident field and return true, otherwise return false.
2249: */
1.76 itojun 2250: static int
1.20 markus 2251: authmethod_is_enabled(Authmethod *method)
2252: {
2253: if (method == NULL)
2254: return 0;
2255: /* return false if options indicate this method is disabled */
2256: if (method->enabled == NULL || *method->enabled == 0)
2257: return 0;
2258: /* return false if batch mode is enabled but method needs interactive mode */
2259: if (method->batch_flag != NULL && *method->batch_flag != 0)
2260: return 0;
2261: return 1;
2262: }
2263:
1.76 itojun 2264: static Authmethod *
1.20 markus 2265: authmethod_lookup(const char *name)
1.1 markus 2266: {
1.20 markus 2267: Authmethod *method = NULL;
2268: if (name != NULL)
2269: for (method = authmethods; method->name != NULL; method++)
2270: if (strcmp(name, method->name) == 0)
2271: return method;
2272: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2273: return NULL;
2274: }
1.1 markus 2275:
1.53 markus 2276: /* XXX internal state */
2277: static Authmethod *current = NULL;
2278: static char *supported = NULL;
2279: static char *preferred = NULL;
1.105 deraadt 2280:
1.20 markus 2281: /*
2282: * Given the authentication method list sent by the server, return the
2283: * next method we should try. If the server initially sends a nil list,
1.67 markus 2284: * use a built-in default list.
1.41 stevesk 2285: */
1.76 itojun 2286: static Authmethod *
1.20 markus 2287: authmethod_get(char *authlist)
2288: {
1.53 markus 2289: char *name = NULL;
1.97 markus 2290: u_int next;
1.41 stevesk 2291:
1.20 markus 2292: /* Use a suitable default if we're passed a nil list. */
2293: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2294: authlist = options.preferred_authentications;
1.20 markus 2295:
1.53 markus 2296: if (supported == NULL || strcmp(authlist, supported) != 0) {
2297: debug3("start over, passed a different list %s", authlist);
1.197 djm 2298: free(supported);
1.53 markus 2299: supported = xstrdup(authlist);
2300: preferred = options.preferred_authentications;
2301: debug3("preferred %s", preferred);
2302: current = NULL;
2303: } else if (current != NULL && authmethod_is_enabled(current))
2304: return current;
1.20 markus 2305:
1.53 markus 2306: for (;;) {
2307: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2308: debug("No more authentication methods to try.");
1.53 markus 2309: current = NULL;
2310: return NULL;
2311: }
2312: preferred += next;
1.23 markus 2313: debug3("authmethod_lookup %s", name);
1.53 markus 2314: debug3("remaining preferred: %s", preferred);
2315: if ((current = authmethod_lookup(name)) != NULL &&
2316: authmethod_is_enabled(current)) {
1.23 markus 2317: debug3("authmethod_is_enabled %s", name);
1.109 markus 2318: debug("Next authentication method: %s", name);
1.197 djm 2319: free(name);
1.53 markus 2320: return current;
1.23 markus 2321: }
1.198 dtucker 2322: free(name);
1.1 markus 2323: }
1.53 markus 2324: }
1.1 markus 2325:
1.79 stevesk 2326: static char *
1.53 markus 2327: authmethods_get(void)
2328: {
2329: Authmethod *method = NULL;
1.278 markus 2330: struct sshbuf *b;
1.93 markus 2331: char *list;
1.278 markus 2332: int r;
1.27 provos 2333:
1.278 markus 2334: if ((b = sshbuf_new()) == NULL)
1.331 djm 2335: fatal_f("sshbuf_new failed");
1.53 markus 2336: for (method = authmethods; method->name != NULL; method++) {
2337: if (authmethod_is_enabled(method)) {
1.278 markus 2338: if ((r = sshbuf_putf(b, "%s%s",
2339: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2340: fatal_fr(r, "buffer error");
1.53 markus 2341: }
2342: }
1.278 markus 2343: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2344: fatal_f("sshbuf_dup_string failed");
1.278 markus 2345: sshbuf_free(b);
1.93 markus 2346: return list;
1.1 markus 2347: }
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