Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.367.2.1
1.367.2.1! bluhm 1: /* $OpenBSD: sshconnect2.c,v 1.367 2023/08/01 08:15:04 dtucker 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,
138: "ORDER", cinfo, NULL, host);
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);
1.367.2.1! bluhm 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);
1.260 markus 471: ssh->authctxt = NULL;
1.20 markus 472:
1.231 markus 473: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 474:
1.248 dtucker 475: if (!authctxt.success)
476: fatal("Authentication failed.");
1.351 djm 477: if (ssh_packet_connection_is_on_socket(ssh)) {
478: verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
479: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
480: authctxt.method->name);
481: } else {
482: verbose("Authenticated to %s (via proxy) using \"%s\".", host,
483: authctxt.method->name);
484: }
1.20 markus 485: }
1.119 markus 486:
1.302 djm 487: static int
1.261 markus 488: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 489: {
490: int r;
491:
492: if (ssh_packet_remaining(ssh) > 0) {
493: char *reply;
494:
495: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
496: goto out;
497: debug2("service_accept: %s", reply);
498: free(reply);
499: } else {
500: debug2("buggy server: service_accept w/o service");
501: }
502: if ((r = sshpkt_get_end(ssh)) != 0)
503: goto out;
504: debug("SSH2_MSG_SERVICE_ACCEPT received");
505:
506: /* initial userauth request */
1.295 djm 507: userauth_none(ssh);
1.231 markus 508:
509: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
510: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
511: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
512: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
513: r = 0;
514: out:
515: return r;
516: }
517:
1.20 markus 518: void
1.295 djm 519: userauth(struct ssh *ssh, char *authlist)
1.51 markus 520: {
1.295 djm 521: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 522:
1.170 djm 523: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 524: authctxt->method->cleanup(ssh);
1.170 djm 525:
1.197 djm 526: free(authctxt->methoddata);
527: authctxt->methoddata = NULL;
1.51 markus 528: if (authlist == NULL) {
529: authlist = authctxt->authlist;
530: } else {
1.197 djm 531: free(authctxt->authlist);
1.51 markus 532: authctxt->authlist = authlist;
533: }
534: for (;;) {
535: Authmethod *method = authmethod_get(authlist);
536: if (method == NULL)
1.264 dtucker 537: fatal("%s@%s: Permission denied (%s).",
538: authctxt->server_user, authctxt->host, authlist);
1.51 markus 539: authctxt->method = method;
1.119 markus 540:
541: /* reset the per method handler */
1.278 markus 542: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 543: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
544:
545: /* and try new method */
1.295 djm 546: if (method->userauth(ssh) != 0) {
1.51 markus 547: debug2("we sent a %s packet, wait for reply", method->name);
548: break;
549: } else {
550: debug2("we did not send a packet, disable method");
551: method->enabled = NULL;
552: }
553: }
554: }
1.105 deraadt 555:
1.302 djm 556: static int
1.261 markus 557: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 558: {
1.331 djm 559: fatal_f("bad message during authentication: type %d", type);
1.218 markus 560: return 0;
1.35 markus 561: }
1.105 deraadt 562:
1.302 djm 563: static int
1.261 markus 564: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 565: {
1.295 djm 566: char *msg = NULL;
1.294 djm 567: size_t len;
568: int r;
1.126 deraadt 569:
1.331 djm 570: debug3_f("entering");
1.294 djm 571: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 572: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 573: goto out;
1.246 djm 574: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
575: fmprintf(stderr, "%s", msg);
1.294 djm 576: r = 0;
577: out:
1.246 djm 578: free(msg);
1.294 djm 579: return r;
1.20 markus 580: }
1.105 deraadt 581:
1.302 djm 582: static int
1.261 markus 583: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 584: {
1.260 markus 585: Authctxt *authctxt = ssh->authctxt;
1.172 djm 586:
1.20 markus 587: if (authctxt == NULL)
1.331 djm 588: fatal_f("no authentication context");
1.197 djm 589: free(authctxt->authlist);
590: authctxt->authlist = NULL;
1.172 djm 591: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 592: authctxt->method->cleanup(ssh);
1.197 djm 593: free(authctxt->methoddata);
594: authctxt->methoddata = NULL;
1.20 markus 595: authctxt->success = 1; /* break out */
1.367.2.1! bluhm 596: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, dispatch_protocol_error);
1.218 markus 597: return 0;
1.20 markus 598: }
1.105 deraadt 599:
1.302 djm 600: #if 0
601: static int
1.261 markus 602: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 603: {
1.260 markus 604: Authctxt *authctxt = ssh->authctxt;
1.172 djm 605:
606: if (authctxt == NULL)
1.331 djm 607: fatal_f("no authentication context");
1.172 djm 608:
609: fatal("Unexpected authentication success during %s.",
610: authctxt->method->name);
1.218 markus 611: return 0;
1.172 djm 612: }
1.302 djm 613: #endif
1.172 djm 614:
1.302 djm 615: static int
1.261 markus 616: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 617: {
1.260 markus 618: Authctxt *authctxt = ssh->authctxt;
1.20 markus 619: char *authlist = NULL;
1.278 markus 620: u_char partial;
1.20 markus 621:
622: if (authctxt == NULL)
623: fatal("input_userauth_failure: no authentication context");
624:
1.307 dtucker 625: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
626: sshpkt_get_u8(ssh, &partial) != 0 ||
627: sshpkt_get_end(ssh) != 0)
1.278 markus 628: goto out;
1.20 markus 629:
1.193 markus 630: if (partial != 0) {
1.351 djm 631: verbose("Authenticated using \"%s\" with partial success.",
632: authctxt->method->name);
1.193 markus 633: /* reset state */
1.251 djm 634: pubkey_reset(authctxt);
1.193 markus 635: }
1.109 markus 636: debug("Authentications that can continue: %s", authlist);
1.20 markus 637:
1.295 djm 638: userauth(ssh, authlist);
1.278 markus 639: authlist = NULL;
640: out:
641: free(authlist);
1.218 markus 642: return 0;
1.51 markus 643: }
1.169 djm 644:
1.287 djm 645: /*
646: * Format an identity for logging including filename, key type, fingerprint
647: * and location (agent, etc.). Caller must free.
648: */
649: static char *
650: format_identity(Identity *id)
651: {
652: char *fp = NULL, *ret = NULL;
1.309 djm 653: const char *note = "";
1.287 djm 654:
655: if (id->key != NULL) {
1.347 djm 656: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1.287 djm 657: SSH_FP_DEFAULT);
658: }
1.309 djm 659: if (id->key) {
660: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
661: note = " token";
1.311 markus 662: else if (sshkey_is_sk(id->key))
1.319 naddy 663: note = " authenticator";
1.309 djm 664: }
1.287 djm 665: xasprintf(&ret, "%s %s%s%s%s%s%s",
666: id->filename,
667: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
668: fp ? fp : "",
1.309 djm 669: id->userprovided ? " explicit" : "", note,
1.287 djm 670: id->agent_fd != -1 ? " agent" : "");
671: free(fp);
672: return ret;
673: }
674:
1.302 djm 675: static int
1.261 markus 676: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 677: {
1.260 markus 678: Authctxt *authctxt = ssh->authctxt;
1.259 markus 679: struct sshkey *key = NULL;
1.117 markus 680: Identity *id = NULL;
1.287 djm 681: int pktype, found = 0, sent = 0;
1.278 markus 682: size_t blen;
1.287 djm 683: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 684: u_char *pkblob = NULL;
685: int r;
1.51 markus 686:
687: if (authctxt == NULL)
688: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 689:
1.278 markus 690: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
691: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
692: (r = sshpkt_get_end(ssh)) != 0)
693: goto done;
1.51 markus 694:
1.278 markus 695: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 696: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 697: goto done;
698: }
1.278 markus 699: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 700: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 701: goto done;
702: }
703: if (key->type != pktype) {
704: error("input_userauth_pk_ok: type mismatch "
705: "for decoded key (received %d, expected %d)",
706: key->type, pktype);
707: goto done;
708: }
709:
1.127 markus 710: /*
711: * search keys in the reverse order, because last candidate has been
712: * moved to the end of the queue. this also avoids confusion by
713: * duplicate keys
714: */
1.136 henning 715: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 716: if (sshkey_equal(key, id->key)) {
1.287 djm 717: found = 1;
1.51 markus 718: break;
719: }
1.117 markus 720: }
1.287 djm 721: if (!found || id == NULL) {
722: fp = sshkey_fingerprint(key, options.fingerprint_hash,
723: SSH_FP_DEFAULT);
1.331 djm 724: error_f("server replied with unknown key: %s %s",
1.287 djm 725: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
726: goto done;
727: }
728: ident = format_identity(id);
729: debug("Server accepts key: %s", ident);
1.295 djm 730: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 731: r = 0;
732: done:
733: sshkey_free(key);
1.287 djm 734: free(ident);
735: free(fp);
1.197 djm 736: free(pkalg);
737: free(pkblob);
1.51 markus 738:
1.106 deraadt 739: /* try another method if we did not send a packet */
1.278 markus 740: if (r == 0 && sent == 0)
1.295 djm 741: userauth(ssh, NULL);
1.278 markus 742: return r;
1.20 markus 743: }
1.121 markus 744:
745: #ifdef GSSAPI
1.302 djm 746: static int
1.295 djm 747: userauth_gssapi(struct ssh *ssh)
1.121 markus 748: {
1.295 djm 749: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 750: Gssctxt *gssctxt = NULL;
751: OM_uint32 min;
1.278 markus 752: int r, ok = 0;
1.302 djm 753: gss_OID mech = NULL;
1.121 markus 754:
755: /* Try one GSSAPI method at a time, rather than sending them all at
756: * once. */
757:
1.302 djm 758: if (authctxt->gss_supported_mechs == NULL)
759: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 760:
1.302 djm 761: /* Check to see whether the mechanism is usable before we offer it */
762: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
763: !ok) {
764: mech = &authctxt->gss_supported_mechs->
765: elements[authctxt->mech_tried];
1.121 markus 766: /* My DER encoding requires length<128 */
1.302 djm 767: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
768: mech, authctxt->host)) {
1.121 markus 769: ok = 1; /* Mechanism works */
770: } else {
1.302 djm 771: authctxt->mech_tried++;
1.121 markus 772: }
773: }
774:
1.302 djm 775: if (!ok || mech == NULL)
1.139 djm 776: return 0;
1.121 markus 777:
778: authctxt->methoddata=(void *)gssctxt;
779:
1.278 markus 780: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
781: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
782: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
783: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
784: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 785: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 786: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 787: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
788: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 789: (r = sshpkt_send(ssh)) != 0)
1.331 djm 790: fatal_fr(r, "send packet");
1.278 markus 791:
792: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
793: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
794: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
795: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 796:
1.302 djm 797: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 798:
799: return 1;
800: }
801:
1.302 djm 802: static void
803: userauth_gssapi_cleanup(struct ssh *ssh)
804: {
805: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
806: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
807:
808: ssh_gssapi_delete_ctx(&gssctxt);
809: authctxt->methoddata = NULL;
810:
811: free(authctxt->gss_supported_mechs);
812: authctxt->gss_supported_mechs = NULL;
813: }
814:
1.130 markus 815: static OM_uint32
1.262 djm 816: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 817: {
1.260 markus 818: Authctxt *authctxt = ssh->authctxt;
1.130 markus 819: Gssctxt *gssctxt = authctxt->methoddata;
820: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 821: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
822: gss_buffer_desc gssbuf;
1.132 markus 823: OM_uint32 status, ms, flags;
1.278 markus 824: int r;
1.133 djm 825:
1.130 markus 826: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 827: recv_tok, &send_tok, &flags);
1.130 markus 828:
829: if (send_tok.length > 0) {
1.278 markus 830: u_char type = GSS_ERROR(status) ?
831: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
832: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
833:
834: if ((r = sshpkt_start(ssh, type)) != 0 ||
835: (r = sshpkt_put_string(ssh, send_tok.value,
836: send_tok.length)) != 0 ||
837: (r = sshpkt_send(ssh)) != 0)
1.331 djm 838: fatal_fr(r, "send %u packet", type);
1.133 djm 839:
1.130 markus 840: gss_release_buffer(&ms, &send_tok);
841: }
1.133 djm 842:
1.130 markus 843: if (status == GSS_S_COMPLETE) {
1.132 markus 844: /* send either complete or MIC, depending on mechanism */
845: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 846: if ((r = sshpkt_start(ssh,
847: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
848: (r = sshpkt_send(ssh)) != 0)
1.331 djm 849: fatal_fr(r, "send completion");
1.132 markus 850: } else {
1.278 markus 851: struct sshbuf *b;
852:
853: if ((b = sshbuf_new()) == NULL)
1.331 djm 854: fatal_f("sshbuf_new failed");
1.278 markus 855: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 djm 856: authctxt->service, "gssapi-with-mic",
857: ssh->kex->session_id);
1.132 markus 858:
1.278 markus 859: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 860: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 861: gssbuf.length = sshbuf_len(b);
1.133 djm 862:
1.132 markus 863: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 864:
1.132 markus 865: if (!GSS_ERROR(status)) {
1.278 markus 866: if ((r = sshpkt_start(ssh,
867: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
868: (r = sshpkt_put_string(ssh, mic.value,
869: mic.length)) != 0 ||
870: (r = sshpkt_send(ssh)) != 0)
1.331 djm 871: fatal_fr(r, "send MIC");
1.132 markus 872: }
1.133 djm 873:
1.278 markus 874: sshbuf_free(b);
1.132 markus 875: gss_release_buffer(&ms, &mic);
1.133 djm 876: }
1.130 markus 877: }
1.133 djm 878:
1.130 markus 879: return status;
880: }
881:
1.302 djm 882: static int
1.261 markus 883: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 884: {
1.260 markus 885: Authctxt *authctxt = ssh->authctxt;
1.121 markus 886: Gssctxt *gssctxt;
1.278 markus 887: size_t oidlen;
888: u_char *oidv = NULL;
889: int r;
1.121 markus 890:
891: if (authctxt == NULL)
892: fatal("input_gssapi_response: no authentication context");
893: gssctxt = authctxt->methoddata;
894:
895: /* Setup our OID */
1.278 markus 896: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
897: goto done;
1.121 markus 898:
1.129 markus 899: if (oidlen <= 2 ||
900: oidv[0] != SSH_GSS_OIDTYPE ||
901: oidv[1] != oidlen - 2) {
902: debug("Badly encoded mechanism OID received");
1.296 djm 903: userauth(ssh, NULL);
1.278 markus 904: goto ok;
1.121 markus 905: }
1.129 markus 906:
907: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
908: fatal("Server returned different OID than expected");
1.121 markus 909:
1.278 markus 910: if ((r = sshpkt_get_end(ssh)) != 0)
911: goto done;
1.121 markus 912:
1.262 djm 913: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 914: /* Start again with next method on list */
915: debug("Trying to start again");
1.296 djm 916: userauth(ssh, NULL);
1.278 markus 917: goto ok;
1.121 markus 918: }
1.278 markus 919: ok:
920: r = 0;
921: done:
922: free(oidv);
923: return r;
1.121 markus 924: }
925:
1.302 djm 926: static int
1.261 markus 927: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 928: {
1.260 markus 929: Authctxt *authctxt = ssh->authctxt;
1.121 markus 930: gss_buffer_desc recv_tok;
1.278 markus 931: u_char *p = NULL;
932: size_t len;
1.130 markus 933: OM_uint32 status;
1.278 markus 934: int r;
1.121 markus 935:
936: if (authctxt == NULL)
937: fatal("input_gssapi_response: no authentication context");
938:
1.278 markus 939: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
940: (r = sshpkt_get_end(ssh)) != 0)
941: goto out;
1.121 markus 942:
1.278 markus 943: recv_tok.value = p;
944: recv_tok.length = len;
1.262 djm 945: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 946:
1.278 markus 947: /* Start again with the next method in the list */
1.121 markus 948: if (GSS_ERROR(status)) {
1.296 djm 949: userauth(ssh, NULL);
1.278 markus 950: /* ok */
1.121 markus 951: }
1.278 markus 952: r = 0;
953: out:
954: free(p);
955: return r;
1.121 markus 956: }
957:
1.302 djm 958: static int
1.261 markus 959: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 960: {
1.260 markus 961: Authctxt *authctxt = ssh->authctxt;
1.121 markus 962: Gssctxt *gssctxt;
963: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
964: gss_buffer_desc recv_tok;
1.194 djm 965: OM_uint32 ms;
1.278 markus 966: u_char *p = NULL;
967: size_t len;
968: int r;
1.121 markus 969:
970: if (authctxt == NULL)
971: fatal("input_gssapi_response: no authentication context");
972: gssctxt = authctxt->methoddata;
973:
1.278 markus 974: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
975: (r = sshpkt_get_end(ssh)) != 0) {
976: free(p);
977: return r;
978: }
1.121 markus 979:
980: /* Stick it into GSSAPI and see what it says */
1.278 markus 981: recv_tok.value = p;
982: recv_tok.length = len;
1.194 djm 983: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 984: &recv_tok, &send_tok, NULL);
1.278 markus 985: free(p);
1.121 markus 986: gss_release_buffer(&ms, &send_tok);
987:
988: /* Server will be returning a failed packet after this one */
1.220 djm 989: return 0;
1.121 markus 990: }
991:
1.302 djm 992: static int
1.261 markus 993: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 994: {
1.278 markus 995: char *msg = NULL;
996: char *lang = NULL;
997: int r;
1.121 markus 998:
1.278 markus 999: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1000: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1001: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1002: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1003: goto out;
1004: r = sshpkt_get_end(ssh);
1.143 stevesk 1005: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1006: out:
1.197 djm 1007: free(msg);
1008: free(lang);
1.278 markus 1009: return r;
1.121 markus 1010: }
1011: #endif /* GSSAPI */
1.20 markus 1012:
1.302 djm 1013: static int
1.295 djm 1014: userauth_none(struct ssh *ssh)
1.23 markus 1015: {
1.295 djm 1016: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1017: int r;
1018:
1.23 markus 1019: /* initial userauth request */
1.278 markus 1020: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1021: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1022: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1023: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1024: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1025: fatal_fr(r, "send packet");
1.23 markus 1026: return 1;
1027: }
1028:
1.302 djm 1029: static int
1.295 djm 1030: userauth_passwd(struct ssh *ssh)
1.1 markus 1031: {
1.295 djm 1032: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1033: char *password, *prompt = NULL;
1.175 dtucker 1034: const char *host = options.host_key_alias ? options.host_key_alias :
1035: authctxt->host;
1.278 markus 1036: int r;
1.6 markus 1037:
1.292 djm 1038: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1039: return 0;
1.13 todd 1040:
1.292 djm 1041: if (authctxt->attempt_passwd != 1)
1.13 todd 1042: error("Permission denied, please try again.");
1.1 markus 1043:
1.290 djm 1044: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1045: password = read_passphrase(prompt, 0);
1.278 markus 1046: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1047: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1048: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1049: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1050: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1051: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1052: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1053: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1054: fatal_fr(r, "send packet");
1.99 markus 1055:
1.290 djm 1056: free(prompt);
1057: if (password != NULL)
1.278 markus 1058: freezero(password, strlen(password));
1059:
1060: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1061: &input_userauth_passwd_changereq);
1062:
1.1 markus 1063: return 1;
1064: }
1.169 djm 1065:
1.99 markus 1066: /*
1067: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1068: */
1.302 djm 1069: static int
1.261 markus 1070: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1071: {
1.260 markus 1072: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1073: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1074: char prompt[256];
1.252 djm 1075: const char *host;
1.278 markus 1076: int r;
1.99 markus 1077:
1078: debug2("input_userauth_passwd_changereq");
1079:
1080: if (authctxt == NULL)
1081: fatal("input_userauth_passwd_changereq: "
1082: "no authentication context");
1.252 djm 1083: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1084:
1.278 markus 1085: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1086: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1087: goto out;
1.99 markus 1088: if (strlen(info) > 0)
1.116 itojun 1089: logit("%s", info);
1.278 markus 1090: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1091: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1092: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1093: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1094: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1095: goto out;
1096:
1.104 deraadt 1097: snprintf(prompt, sizeof(prompt),
1.99 markus 1098: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1099: authctxt->server_user, host);
1.99 markus 1100: password = read_passphrase(prompt, 0);
1.278 markus 1101: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1102: goto out;
1103:
1104: freezero(password, strlen(password));
1.99 markus 1105: password = NULL;
1106: while (password == NULL) {
1.104 deraadt 1107: snprintf(prompt, sizeof(prompt),
1.99 markus 1108: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1109: authctxt->server_user, host);
1.99 markus 1110: password = read_passphrase(prompt, RP_ALLOW_EOF);
1111: if (password == NULL) {
1112: /* bail out */
1.278 markus 1113: r = 0;
1114: goto out;
1.99 markus 1115: }
1.104 deraadt 1116: snprintf(prompt, sizeof(prompt),
1.99 markus 1117: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1118: authctxt->server_user, host);
1.99 markus 1119: retype = read_passphrase(prompt, 0);
1120: if (strcmp(password, retype) != 0) {
1.278 markus 1121: freezero(password, strlen(password));
1.116 itojun 1122: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1123: password = NULL;
1124: }
1.278 markus 1125: freezero(retype, strlen(retype));
1.99 markus 1126: }
1.278 markus 1127: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1128: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1129: (r = sshpkt_send(ssh)) != 0)
1130: goto out;
1.104 deraadt 1131:
1.278 markus 1132: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1133: &input_userauth_passwd_changereq);
1.278 markus 1134: r = 0;
1135: out:
1136: if (password)
1137: freezero(password, strlen(password));
1138: free(info);
1139: free(lang);
1140: return r;
1.117 markus 1141: }
1142:
1.272 djm 1143: /*
1144: * Select an algorithm for publickey signatures.
1145: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1146: *
1147: * Call with ssh==NULL to ignore server-sig-algs extension list and
1148: * only attempt with the key's base signature type.
1149: */
1150: static char *
1151: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1152: {
1.274 djm 1153: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.348 djm 1154: const char *server_sig_algs;
1.231 markus 1155:
1.272 djm 1156: /*
1157: * The signature algorithm will only differ from the key algorithm
1158: * for RSA keys/certs and when the server advertises support for
1159: * newer (SHA2) algorithms.
1160: */
1161: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1162: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1163: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1164: /* Filter base key signature alg against our configuration */
1.279 markus 1165: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1166: options.pubkey_accepted_algos, NULL);
1.231 markus 1167: }
1168:
1.272 djm 1169: /*
1.348 djm 1170: * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1171: * fails to advertise it via SSH2_MSG_EXT_INFO.
1172: */
1173: server_sig_algs = ssh->kex->server_sig_algs;
1174: if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1175: server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1176:
1177: /*
1.272 djm 1178: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1179: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1180: * that also appears in the supported signature algorithms list from
1181: * the server.
1182: */
1.342 dtucker 1183: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1184: while ((cp = strsep(&allowed, ",")) != NULL) {
1185: if (sshkey_type_from_name(cp) != key->type)
1186: continue;
1.323 djm 1187: tmp = match_list(sshkey_sigalg_by_name(cp),
1.348 djm 1188: server_sig_algs, NULL);
1.274 djm 1189: if (tmp != NULL)
1190: alg = xstrdup(cp);
1191: free(tmp);
1.272 djm 1192: if (alg != NULL)
1193: break;
1.269 djm 1194: }
1.272 djm 1195: free(oallowed);
1196: return alg;
1.269 djm 1197: }
1198:
1.117 markus 1199: static int
1.214 djm 1200: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1201: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1202: {
1.309 djm 1203: struct sshkey *sign_key = NULL, *prv = NULL;
1.360 djm 1204: int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1205: struct notifier_ctx *notifier = NULL;
1.325 djm 1206: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1207:
1208: *sigp = NULL;
1209: *lenp = 0;
1.99 markus 1210:
1.272 djm 1211: /* The agent supports this key. */
1.269 djm 1212: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1213: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1214: data, datalen, alg, compat);
1.269 djm 1215: }
1.214 djm 1216:
1.117 markus 1217: /*
1.272 djm 1218: * We have already loaded the private key or the private key is
1219: * stored in external hardware.
1.117 markus 1220: */
1.255 djm 1221: if (id->key != NULL &&
1.272 djm 1222: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1223: sign_key = id->key;
1.360 djm 1224: is_agent = 1;
1.309 djm 1225: } else {
1226: /* Load the private key from the file. */
1227: if ((prv = load_identity_file(id)) == NULL)
1228: return SSH_ERR_KEY_NOT_FOUND;
1229: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1230: error_f("private key %s contents do not match public",
1.347 djm 1231: id->filename);
1.309 djm 1232: r = SSH_ERR_KEY_NOT_FOUND;
1233: goto out;
1234: }
1235: sign_key = prv;
1.360 djm 1236: }
1.341 djm 1237: retry_pin:
1.360 djm 1238: /* Prompt for touch for non-agent FIDO keys that request UP */
1239: if (!is_agent && sshkey_is_sk(sign_key) &&
1240: (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1241: /* XXX should batch mode just skip these? */
1242: if ((fp = sshkey_fingerprint(sign_key,
1243: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1244: fatal_f("fingerprint failed");
1245: notifier = notify_start(options.batch_mode,
1246: "Confirm user presence for key %s %s",
1247: sshkey_type(sign_key), fp);
1248: free(fp);
1.272 djm 1249: }
1.310 djm 1250: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1251: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1252: debug_fr(r, "sshkey_sign");
1.360 djm 1253: if (!retried && pin == NULL && !is_agent &&
1254: sshkey_is_sk(sign_key) &&
1.341 djm 1255: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1256: notify_complete(notifier, NULL);
1257: notifier = NULL;
1.360 djm 1258: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1259: sshkey_type(sign_key), id->filename);
1260: pin = read_passphrase(prompt, 0);
1.341 djm 1261: retried = 1;
1262: goto retry_pin;
1263: }
1.309 djm 1264: goto out;
1265: }
1.341 djm 1266:
1.309 djm 1267: /*
1268: * PKCS#11 tokens may not support all signature algorithms,
1269: * so check what we get back.
1270: */
1271: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1272: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1273: goto out;
1.265 djm 1274: }
1.309 djm 1275: /* success */
1276: r = 0;
1277: out:
1.325 djm 1278: free(prompt);
1279: if (pin != NULL)
1280: freezero(pin, strlen(pin));
1.341 djm 1281: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1282: sshkey_free(prv);
1.269 djm 1283: return r;
1.51 markus 1284: }
1285:
1.76 itojun 1286: static int
1.255 djm 1287: id_filename_matches(Identity *id, Identity *private_id)
1288: {
1.356 djm 1289: static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
1.255 djm 1290: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1291: size_t i, slen;
1292:
1293: if (strcmp(id->filename, private_id->filename) == 0)
1294: return 1;
1295: for (i = 0; suffixes[i]; i++) {
1296: slen = strlen(suffixes[i]);
1297: if (len > slen && plen == len - slen &&
1298: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1299: memcmp(id->filename, private_id->filename, plen) == 0)
1300: return 1;
1301: }
1302: return 0;
1303: }
1304:
1305: static int
1.295 djm 1306: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1307: {
1.295 djm 1308: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1309: struct sshbuf *b = NULL;
1310: Identity *private_id, *sign_id = NULL;
1311: u_char *signature = NULL;
1312: size_t slen = 0, skip = 0;
1313: int r, fallback_sigtype, sent = 0;
1314: char *alg = NULL, *fp = NULL;
1.353 djm 1315: const char *loc = "", *method = "publickey";
1.354 djm 1316: int hostbound = 0;
1.353 djm 1317:
1318: /* prefer host-bound pubkey signatures if supported by server */
1.354 djm 1319: if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
1320: (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
1321: hostbound = 1;
1.353 djm 1322: method = "publickey-hostbound-v00@openssh.com";
1.354 djm 1323: }
1.1 markus 1324:
1.222 djm 1325: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1326: SSH_FP_DEFAULT)) == NULL)
1327: return 0;
1.51 markus 1328:
1.354 djm 1329: debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
1.1 markus 1330:
1.227 djm 1331: /*
1332: * If the key is an certificate, try to find a matching private key
1333: * and use it to complete the signature.
1.241 djm 1334: * If no such private key exists, fall back to trying the certificate
1335: * key itself in case it has a private half already loaded.
1.272 djm 1336: * This will try to set sign_id to the private key that will perform
1337: * the signature.
1.227 djm 1338: */
1.272 djm 1339: if (sshkey_is_cert(id->key)) {
1.227 djm 1340: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1341: if (sshkey_equal_public(id->key, private_id->key) &&
1342: id->key->type != private_id->key->type) {
1.272 djm 1343: sign_id = private_id;
1.227 djm 1344: break;
1345: }
1346: }
1.255 djm 1347: /*
1348: * Exact key matches are preferred, but also allow
1349: * filename matches for non-PKCS#11/agent keys that
1350: * didn't load public keys. This supports the case
1351: * of keeping just a private key file and public
1352: * certificate on disk.
1353: */
1.272 djm 1354: if (sign_id == NULL &&
1355: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1356: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1357: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1358: if (private_id->key == NULL &&
1359: id_filename_matches(id, private_id)) {
1.272 djm 1360: sign_id = private_id;
1.255 djm 1361: break;
1362: }
1363: }
1364: }
1.272 djm 1365: if (sign_id != NULL) {
1.331 djm 1366: debug2_f("using private key \"%s\"%s for "
1.349 djm 1367: "certificate", sign_id->filename,
1368: sign_id->agent_fd != -1 ? " from agent" : "");
1.227 djm 1369: } else {
1.331 djm 1370: debug_f("no separate private key for certificate "
1371: "\"%s\"", id->filename);
1.227 djm 1372: }
1373: }
1374:
1.272 djm 1375: /*
1376: * If the above didn't select another identity to do the signing
1377: * then default to the one we started with.
1378: */
1379: if (sign_id == NULL)
1380: sign_id = id;
1381:
1382: /* assemble and sign data */
1383: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1384: free(alg);
1385: slen = 0;
1386: signature = NULL;
1387: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1388: id->key)) == NULL) {
1.331 djm 1389: error_f("no mutual signature supported");
1.272 djm 1390: goto out;
1391: }
1.331 djm 1392: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1393:
1394: sshbuf_free(b);
1395: if ((b = sshbuf_new()) == NULL)
1.331 djm 1396: fatal_f("sshbuf_new failed");
1.345 djm 1397: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 djm 1398: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1399: fatal_fr(r, "sshbuf_putb");
1.272 djm 1400: } else {
1.346 djm 1401: if ((r = sshbuf_put_stringb(b,
1402: ssh->kex->session_id)) != 0)
1403: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1404: }
1.278 markus 1405: skip = sshbuf_len(b);
1.272 djm 1406: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1407: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1408: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.353 djm 1409: (r = sshbuf_put_cstring(b, method)) != 0 ||
1.272 djm 1410: (r = sshbuf_put_u8(b, 1)) != 0 ||
1411: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1412: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1413: fatal_fr(r, "assemble signed data");
1.272 djm 1414: }
1.354 djm 1415: if (hostbound) {
1.353 djm 1416: if (ssh->kex->initial_hostkey == NULL) {
1417: fatal_f("internal error: initial hostkey "
1418: "not recorded");
1419: }
1420: if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
1421: fatal_fr(r, "assemble %s hostkey", method);
1422: }
1.272 djm 1423: /* generate signature */
1424: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1425: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1426: if (r == 0)
1427: break;
1428: else if (r == SSH_ERR_KEY_NOT_FOUND)
1429: goto out; /* soft failure */
1430: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1431: !fallback_sigtype) {
1432: if (sign_id->agent_fd != -1)
1433: loc = "agent ";
1434: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1435: loc = "token ";
1436: logit("%skey %s %s returned incorrect signature type",
1437: loc, sshkey_type(id->key), fp);
1438: continue;
1439: }
1.331 djm 1440: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1441: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1442: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1443: goto out;
1.17 markus 1444: }
1.272 djm 1445: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1446: fatal_f("no signature");
1.51 markus 1447:
1.1 markus 1448: /* append signature */
1.272 djm 1449: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1450: fatal_fr(r, "append signature");
1.1 markus 1451:
1.272 djm 1452: #ifdef DEBUG_PK
1453: sshbuf_dump(b, stderr);
1454: #endif
1.1 markus 1455: /* skip session id and packet type */
1.272 djm 1456: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1457: fatal_fr(r, "consume");
1.1 markus 1458:
1459: /* put remaining data from buffer into packet */
1.272 djm 1460: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1461: (r = sshpkt_putb(ssh, b)) != 0 ||
1462: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1463: fatal_fr(r, "enqueue request");
1.272 djm 1464:
1465: /* success */
1466: sent = 1;
1.17 markus 1467:
1.272 djm 1468: out:
1469: free(fp);
1470: free(alg);
1471: sshbuf_free(b);
1472: freezero(signature, slen);
1473: return sent;
1.16 markus 1474: }
1475:
1.76 itojun 1476: static int
1.295 djm 1477: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1478: {
1.295 djm 1479: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1480: u_char *blob = NULL;
1481: char *alg = NULL;
1.278 markus 1482: size_t bloblen;
1483: u_int have_sig = 0;
1484: int sent = 0, r;
1.20 markus 1485:
1.272 djm 1486: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1487: debug_f("no mutual signature algorithm");
1.272 djm 1488: goto out;
1489: }
1.16 markus 1490:
1.278 markus 1491: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1492: /* we cannot handle this key */
1.331 djm 1493: debug3_f("cannot handle key");
1.272 djm 1494: goto out;
1.16 markus 1495: }
1.51 markus 1496: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1497: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1498:
1.278 markus 1499: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1500: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1501: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1502: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1503: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1504: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1505: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1506: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1507: fatal_fr(r, "send packet");
1.272 djm 1508: sent = 1;
1.278 markus 1509:
1510: out:
1.272 djm 1511: free(alg);
1.197 djm 1512: free(blob);
1.272 djm 1513: return sent;
1.51 markus 1514: }
1515:
1.259 markus 1516: static struct sshkey *
1.229 jcs 1517: load_identity_file(Identity *id)
1.51 markus 1518: {
1.259 markus 1519: struct sshkey *private = NULL;
1.229 jcs 1520: char prompt[300], *passphrase, *comment;
1.308 dtucker 1521: int r, quit = 0, i;
1.52 markus 1522: struct stat st;
1.16 markus 1523:
1.306 deraadt 1524: if (stat(id->filename, &st) == -1) {
1.330 djm 1525: do_log2(id->userprovided ?
1526: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1527: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1528: return NULL;
1529: }
1.214 djm 1530: snprintf(prompt, sizeof prompt,
1.229 jcs 1531: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1532: for (i = 0; i <= options.number_of_password_prompts; i++) {
1533: if (i == 0)
1534: passphrase = "";
1535: else {
1.20 markus 1536: passphrase = read_passphrase(prompt, 0);
1.214 djm 1537: if (*passphrase == '\0') {
1.20 markus 1538: debug2("no passphrase given, try next key");
1.214 djm 1539: free(passphrase);
1540: break;
1541: }
1542: }
1.229 jcs 1543: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1544: passphrase, &private, &comment))) {
1.214 djm 1545: case 0:
1546: break;
1547: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1548: if (options.batch_mode) {
1549: quit = 1;
1550: break;
1551: }
1.215 djm 1552: if (i != 0)
1553: debug2("bad passphrase given, try again...");
1.214 djm 1554: break;
1555: case SSH_ERR_SYSTEM_ERROR:
1556: if (errno == ENOENT) {
1.331 djm 1557: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1558: quit = 1;
1.214 djm 1559: break;
1.20 markus 1560: }
1.214 djm 1561: /* FALLTHROUGH */
1562: default:
1.331 djm 1563: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1564: quit = 1;
1565: break;
1566: }
1.311 markus 1567: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1568: options.sk_provider == NULL) {
1.319 naddy 1569: debug("key \"%s\" is an authenticator-hosted key, "
1570: "but no provider specified", id->filename);
1.309 djm 1571: sshkey_free(private);
1572: private = NULL;
1573: quit = 1;
1574: }
1.361 djm 1575: if (!quit && (r = sshkey_check_rsa_length(private,
1576: options.required_rsa_size)) != 0) {
1577: debug_fr(r, "Skipping key %s", id->filename);
1578: sshkey_free(private);
1579: private = NULL;
1580: quit = 1;
1581: }
1.230 djm 1582: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1583: !(id->key && id->isprivate))
1584: maybe_add_key_to_agent(id->filename, private, comment,
1585: passphrase);
1.278 markus 1586: if (i > 0)
1587: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1588: free(comment);
1.214 djm 1589: if (private != NULL || quit)
1590: break;
1.16 markus 1591: }
1.51 markus 1592: return private;
1593: }
1594:
1.272 djm 1595: static int
1596: key_type_allowed_by_config(struct sshkey *key)
1597: {
1598: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1599: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1600: return 1;
1601:
1602: /* RSA keys/certs might be allowed by alternate signature types */
1603: switch (key->type) {
1604: case KEY_RSA:
1605: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1606: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1607: return 1;
1608: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1609: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1610: return 1;
1611: break;
1612: case KEY_RSA_CERT:
1613: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1614: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1615: return 1;
1616: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1617: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1618: return 1;
1619: break;
1620: }
1621: return 0;
1622: }
1623:
1.352 djm 1624: /* obtain a list of keys from the agent */
1625: static int
1626: get_agent_identities(struct ssh *ssh, int *agent_fdp,
1627: struct ssh_identitylist **idlistp)
1628: {
1629: int r, agent_fd;
1630: struct ssh_identitylist *idlist;
1631:
1632: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1633: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1634: debug_fr(r, "ssh_get_authentication_socket");
1635: return r;
1636: }
1637: if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
1638: ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
1639: debug_f("bound agent to hostkey");
1640: else
1641: debug2_fr(r, "ssh_agent_bind_hostkey");
1642:
1643: if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1644: debug_fr(r, "ssh_fetch_identitylist");
1645: close(agent_fd);
1646: return r;
1647: }
1648: /* success */
1649: *agent_fdp = agent_fd;
1650: *idlistp = idlist;
1651: debug_f("agent returned %zu keys", idlist->nkeys);
1652: return 0;
1653: }
1.272 djm 1654:
1.117 markus 1655: /*
1656: * try keys in the following order:
1.332 djm 1657: * 1. certificates listed in the config file
1658: * 2. other input certificates
1.227 djm 1659: * 3. agent keys that are found in the config file
1660: * 4. other agent keys
1661: * 5. keys that are only listed in the config file
1.117 markus 1662: */
1663: static void
1.352 djm 1664: pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
1.51 markus 1665: {
1.214 djm 1666: struct identity *id, *id2, *tmp;
1667: struct idlist agent, files, *preferred;
1668: struct sshkey *key;
1.230 djm 1669: int agent_fd = -1, i, r, found;
1.214 djm 1670: size_t j;
1671: struct ssh_identitylist *idlist;
1.287 djm 1672: char *ident;
1.51 markus 1673:
1.117 markus 1674: TAILQ_INIT(&agent); /* keys from the agent */
1675: TAILQ_INIT(&files); /* keys from the config file */
1676: preferred = &authctxt->keys;
1677: TAILQ_INIT(preferred); /* preferred order of keys */
1678:
1.190 djm 1679: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1680: for (i = 0; i < options.num_identity_files; i++) {
1681: key = options.identity_keys[i];
1.309 djm 1682: if (key && key->cert &&
1683: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1684: debug_f("ignoring certificate %s: not a user "
1685: "certificate", options.identity_files[i]);
1.309 djm 1686: continue;
1687: }
1.311 markus 1688: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1689: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1690: "SecurityKeyProvider has been specified",
1.331 djm 1691: options.identity_files[i]);
1.117 markus 1692: continue;
1.309 djm 1693: }
1.117 markus 1694: options.identity_keys[i] = NULL;
1.150 djm 1695: id = xcalloc(1, sizeof(*id));
1.230 djm 1696: id->agent_fd = -1;
1.117 markus 1697: id->key = key;
1698: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1699: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1700: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1701: }
1.227 djm 1702: /* list of certificates specified by user */
1703: for (i = 0; i < options.num_certificate_files; i++) {
1704: key = options.certificates[i];
1.278 markus 1705: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1706: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1707: debug_f("ignoring certificate %s: not a user "
1708: "certificate", options.identity_files[i]);
1.227 djm 1709: continue;
1.309 djm 1710: }
1.311 markus 1711: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1712: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1713: "certificate %s as no "
1.309 djm 1714: "SecurityKeyProvider has been specified",
1.331 djm 1715: options.identity_files[i]);
1.309 djm 1716: continue;
1717: }
1.227 djm 1718: id = xcalloc(1, sizeof(*id));
1.230 djm 1719: id->agent_fd = -1;
1.227 djm 1720: id->key = key;
1721: id->filename = xstrdup(options.certificate_files[i]);
1722: id->userprovided = options.certificate_file_userprovided[i];
1723: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1724: }
1725: /* list of keys supported by the agent */
1.352 djm 1726: if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
1.214 djm 1727: for (j = 0; j < idlist->nkeys; j++) {
1.361 djm 1728: if ((r = sshkey_check_rsa_length(idlist->keys[j],
1729: options.required_rsa_size)) != 0) {
1730: debug_fr(r, "ignoring %s agent key",
1731: sshkey_ssh_name(idlist->keys[j]));
1732: continue;
1733: }
1.117 markus 1734: found = 0;
1735: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1736: /*
1737: * agent keys from the config file are
1738: * preferred
1739: */
1740: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1741: TAILQ_REMOVE(&files, id, next);
1742: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1743: id->agent_fd = agent_fd;
1.117 markus 1744: found = 1;
1745: break;
1746: }
1747: }
1.135 markus 1748: if (!found && !options.identities_only) {
1.150 djm 1749: id = xcalloc(1, sizeof(*id));
1.214 djm 1750: /* XXX "steals" key/comment from idlist */
1751: id->key = idlist->keys[j];
1752: id->filename = idlist->comments[j];
1753: idlist->keys[j] = NULL;
1754: idlist->comments[j] = NULL;
1755: id->agent_fd = agent_fd;
1.117 markus 1756: TAILQ_INSERT_TAIL(&agent, id, next);
1757: }
1758: }
1.214 djm 1759: ssh_free_identitylist(idlist);
1.117 markus 1760: /* append remaining agent keys */
1.324 bket 1761: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1762: authctxt->agent_fd = agent_fd;
1.244 djm 1763: }
1764: /* Prefer PKCS11 keys that are explicitly listed */
1765: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1766: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1767: continue;
1768: found = 0;
1769: TAILQ_FOREACH(id2, &files, next) {
1770: if (id2->key == NULL ||
1.321 djm 1771: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1772: continue;
1773: if (sshkey_equal(id->key, id2->key)) {
1774: TAILQ_REMOVE(&files, id, next);
1775: TAILQ_INSERT_TAIL(preferred, id, next);
1776: found = 1;
1777: break;
1778: }
1779: }
1780: /* If IdentitiesOnly set and key not found then don't use it */
1781: if (!found && options.identities_only) {
1782: TAILQ_REMOVE(&files, id, next);
1.278 markus 1783: freezero(id, sizeof(*id));
1.244 djm 1784: }
1.117 markus 1785: }
1786: /* append remaining keys from the config file */
1.324 bket 1787: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1788: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1789: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1790: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1791: debug("Skipping %s key %s - "
1.342 dtucker 1792: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1793: sshkey_ssh_name(id->key), id->filename);
1794: TAILQ_REMOVE(preferred, id, next);
1795: sshkey_free(id->key);
1796: free(id->filename);
1797: memset(id, 0, sizeof(*id));
1798: continue;
1799: }
1.117 markus 1800: }
1.287 djm 1801: /* List the keys we plan on using */
1802: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1803: ident = format_identity(id);
1804: debug("Will attempt key: %s", ident);
1805: free(ident);
1806: }
1.331 djm 1807: debug2_f("done");
1.17 markus 1808: }
1809:
1.117 markus 1810: static void
1.303 djm 1811: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1812: {
1.302 djm 1813: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1814: Identity *id;
1.51 markus 1815:
1.289 djm 1816: if (authctxt->agent_fd != -1) {
1.214 djm 1817: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1818: authctxt->agent_fd = -1;
1819: }
1.117 markus 1820: for (id = TAILQ_FIRST(&authctxt->keys); id;
1821: id = TAILQ_FIRST(&authctxt->keys)) {
1822: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1823: sshkey_free(id->key);
1.197 djm 1824: free(id->filename);
1825: free(id);
1.117 markus 1826: }
1.1 markus 1827: }
1828:
1.251 djm 1829: static void
1830: pubkey_reset(Authctxt *authctxt)
1831: {
1832: Identity *id;
1833:
1834: TAILQ_FOREACH(id, &authctxt->keys, next)
1835: id->tried = 0;
1836: }
1837:
1.225 markus 1838: static int
1.295 djm 1839: userauth_pubkey(struct ssh *ssh)
1.20 markus 1840: {
1.295 djm 1841: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1842: Identity *id;
1.20 markus 1843: int sent = 0;
1.287 djm 1844: char *ident;
1.20 markus 1845:
1.117 markus 1846: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1847: if (id->tried++)
1848: return (0);
1.127 markus 1849: /* move key to the end of the queue */
1.117 markus 1850: TAILQ_REMOVE(&authctxt->keys, id, next);
1851: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1852: /*
1853: * send a test message if we have the public key. for
1854: * encrypted keys we cannot do this and have to load the
1855: * private key instead
1856: */
1.200 djm 1857: if (id->key != NULL) {
1.367 dtucker 1858: ident = format_identity(id);
1859: debug("Offering public key: %s", ident);
1860: free(ident);
1861: sent = send_pubkey_test(ssh, id);
1.200 djm 1862: } else {
1.117 markus 1863: debug("Trying private key: %s", id->filename);
1.229 jcs 1864: id->key = load_identity_file(id);
1.117 markus 1865: if (id->key != NULL) {
1.362 dtucker 1866: if (id->key != NULL) {
1.225 markus 1867: id->isprivate = 1;
1.295 djm 1868: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1869: }
1.278 markus 1870: sshkey_free(id->key);
1.117 markus 1871: id->key = NULL;
1.251 djm 1872: id->isprivate = 0;
1.51 markus 1873: }
1874: }
1.117 markus 1875: if (sent)
1876: return (sent);
1.28 markus 1877: }
1.117 markus 1878: return (0);
1.20 markus 1879: }
1880:
1.23 markus 1881: /*
1882: * Send userauth request message specifying keyboard-interactive method.
1883: */
1.302 djm 1884: static int
1.295 djm 1885: userauth_kbdint(struct ssh *ssh)
1.23 markus 1886: {
1.295 djm 1887: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1888: int r;
1.23 markus 1889:
1.292 djm 1890: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1891: return 0;
1.82 markus 1892: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1893: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1894: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1895: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1896: return 0;
1897: }
1.23 markus 1898:
1899: debug2("userauth_kbdint");
1.278 markus 1900: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1901: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1902: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1903: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1904: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1905: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1906: options.kbd_interactive_devices : "")) != 0 ||
1907: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1908: fatal_fr(r, "send packet");
1.23 markus 1909:
1.278 markus 1910: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1911: return 1;
1912: }
1913:
1914: /*
1.46 markus 1915: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1916: */
1.302 djm 1917: static int
1.261 markus 1918: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1919: {
1.260 markus 1920: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1921: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1922: char *display_prompt = NULL, *response = NULL;
1.278 markus 1923: u_char echo = 0;
1.32 markus 1924: u_int num_prompts, i;
1.278 markus 1925: int r;
1.23 markus 1926:
1.335 djm 1927: debug2_f("entering");
1.23 markus 1928:
1929: if (authctxt == NULL)
1.335 djm 1930: fatal_f("no authentication context");
1.82 markus 1931:
1932: authctxt->info_req_seen = 1;
1.23 markus 1933:
1.278 markus 1934: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1935: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1936: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1937: goto out;
1.23 markus 1938: if (strlen(name) > 0)
1.116 itojun 1939: logit("%s", name);
1.23 markus 1940: if (strlen(inst) > 0)
1.116 itojun 1941: logit("%s", inst);
1.23 markus 1942:
1.278 markus 1943: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1944: goto out;
1.23 markus 1945: /*
1946: * Begin to build info response packet based on prompts requested.
1947: * We commit to providing the correct number of responses, so if
1948: * further on we run into a problem that prevents this, we have to
1949: * be sure and clean this up and send a correct error response.
1950: */
1.278 markus 1951: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1952: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1953: goto out;
1.23 markus 1954:
1.335 djm 1955: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1956: for (i = 0; i < num_prompts; i++) {
1.278 markus 1957: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1958: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1959: goto out;
1.336 djm 1960: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1961: authctxt->server_user, options.host_key_alias ?
1.336 djm 1962: options.host_key_alias : authctxt->host, prompt) == -1)
1963: fatal_f("asmprintf failed");
1.335 djm 1964: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1965: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1966: goto out;
1967: freezero(response, strlen(response));
1.197 djm 1968: free(prompt);
1.335 djm 1969: free(display_prompt);
1970: display_prompt = response = prompt = NULL;
1.23 markus 1971: }
1.278 markus 1972: /* done with parsing incoming message. */
1973: if ((r = sshpkt_get_end(ssh)) != 0 ||
1974: (r = sshpkt_add_padding(ssh, 64)) != 0)
1975: goto out;
1976: r = sshpkt_send(ssh);
1977: out:
1978: if (response)
1979: freezero(response, strlen(response));
1980: free(prompt);
1.335 djm 1981: free(display_prompt);
1.278 markus 1982: free(name);
1983: free(inst);
1984: free(lang);
1985: return r;
1.68 markus 1986: }
1987:
1.100 markus 1988: static int
1.294 djm 1989: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 1990: const u_char *data, size_t datalen)
1.100 markus 1991: {
1.223 djm 1992: struct sshbuf *b;
1.101 markus 1993: struct stat st;
1.100 markus 1994: pid_t pid;
1.304 deraadt 1995: int r, to[2], from[2], status;
1.295 djm 1996: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 1997: u_char rversion = 0, version = 2;
1998: void (*osigchld)(int);
1.100 markus 1999:
1.223 djm 2000: *sigp = NULL;
2001: *lenp = 0;
1.100 markus 2002:
1.306 deraadt 2003: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 2004: error_f("not installed: %s", strerror(errno));
1.223 djm 2005: return -1;
2006: }
2007: if (fflush(stdout) != 0) {
1.331 djm 2008: error_f("fflush: %s", strerror(errno));
1.101 markus 2009: return -1;
2010: }
1.306 deraadt 2011: if (pipe(to) == -1) {
1.331 djm 2012: error_f("pipe: %s", strerror(errno));
1.100 markus 2013: return -1;
2014: }
1.306 deraadt 2015: if (pipe(from) == -1) {
1.331 djm 2016: error_f("pipe: %s", strerror(errno));
1.100 markus 2017: return -1;
2018: }
1.306 deraadt 2019: if ((pid = fork()) == -1) {
1.331 djm 2020: error_f("fork: %s", strerror(errno));
1.100 markus 2021: return -1;
2022: }
1.317 dtucker 2023: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 2024: if (pid == 0) {
2025: close(from[0]);
1.306 deraadt 2026: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2027: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2028: close(to[1]);
1.306 deraadt 2029: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2030: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2031: close(from[1]);
2032: close(to[0]);
1.304 deraadt 2033:
1.306 deraadt 2034: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2035: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2036: sock = STDERR_FILENO + 1;
1.363 dtucker 2037: if (fcntl(sock, F_SETFD, 0) == -1) /* keep the socket on exec */
2038: debug3_f("fcntl F_SETFD: %s", strerror(errno));
1.223 djm 2039: closefrom(sock + 1);
1.304 deraadt 2040:
1.331 djm 2041: debug3_f("[child] pid=%ld, exec %s",
2042: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2043: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2044: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2045: strerror(errno));
2046: }
2047: close(from[1]);
2048: close(to[0]);
1.305 djm 2049: sock = STDERR_FILENO + 1;
1.100 markus 2050:
1.223 djm 2051: if ((b = sshbuf_new()) == NULL)
1.331 djm 2052: fatal_f("sshbuf_new failed");
1.223 djm 2053: /* send # of sock, data to be signed */
1.253 djm 2054: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2055: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2056: fatal_fr(r, "buffer error");
1.223 djm 2057: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2058: fatal_f("couldn't send request");
1.223 djm 2059: sshbuf_reset(b);
2060: r = ssh_msg_recv(from[0], b);
1.101 markus 2061: close(from[0]);
2062: close(to[1]);
1.223 djm 2063: if (r < 0) {
1.331 djm 2064: error_f("no reply");
1.223 djm 2065: goto fail;
2066: }
1.101 markus 2067:
1.223 djm 2068: errno = 0;
1.306 deraadt 2069: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2070: if (errno != EINTR) {
1.331 djm 2071: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2072: goto fail;
2073: }
2074: }
2075: if (!WIFEXITED(status)) {
1.331 djm 2076: error_f("exited abnormally");
1.223 djm 2077: goto fail;
2078: }
2079: if (WEXITSTATUS(status) != 0) {
1.331 djm 2080: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2081: goto fail;
2082: }
2083: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2084: error_fr(r, "buffer error");
1.223 djm 2085: goto fail;
2086: }
2087: if (rversion != version) {
1.331 djm 2088: error_f("bad version");
1.223 djm 2089: goto fail;
2090: }
2091: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2092: error_fr(r, "buffer error");
1.223 djm 2093: fail:
1.317 dtucker 2094: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2095: sshbuf_free(b);
1.100 markus 2096: return -1;
2097: }
1.317 dtucker 2098: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2099: sshbuf_free(b);
1.100 markus 2100:
2101: return 0;
2102: }
2103:
1.302 djm 2104: static int
1.295 djm 2105: userauth_hostbased(struct ssh *ssh)
1.68 markus 2106: {
1.295 djm 2107: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2108: struct sshkey *private = NULL;
2109: struct sshbuf *b = NULL;
2110: u_char *sig = NULL, *keyblob = NULL;
2111: char *fp = NULL, *chost = NULL, *lname = NULL;
2112: size_t siglen = 0, keylen = 0;
2113: int i, r, success = 0;
2114:
2115: if (authctxt->ktypes == NULL) {
1.344 dtucker 2116: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2117: authctxt->ktypes = authctxt->oktypes;
2118: }
1.213 djm 2119:
1.223 djm 2120: /*
1.344 dtucker 2121: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2122: * trying each hostkey that matches the type in turn.
2123: */
2124: for (;;) {
2125: if (authctxt->active_ktype == NULL)
2126: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2127: if (authctxt->active_ktype == NULL ||
2128: *authctxt->active_ktype == '\0')
2129: break;
1.331 djm 2130: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2131:
1.223 djm 2132: /* check for a useful key */
2133: private = NULL;
2134: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2135: if (authctxt->sensitive->keys[i] == NULL ||
2136: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2137: continue;
1.355 djm 2138: if (!sshkey_match_keyname_to_sigalgs(
1.223 djm 2139: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.355 djm 2140: authctxt->active_ktype))
1.223 djm 2141: continue;
1.68 markus 2142: /* we take and free the key */
1.223 djm 2143: private = authctxt->sensitive->keys[i];
2144: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2145: break;
2146: }
1.223 djm 2147: /* Found one */
2148: if (private != NULL)
2149: break;
2150: /* No more keys of this type; advance */
2151: authctxt->active_ktype = NULL;
1.68 markus 2152: }
1.223 djm 2153: if (private == NULL) {
2154: free(authctxt->oktypes);
2155: authctxt->oktypes = authctxt->ktypes = NULL;
2156: authctxt->active_ktype = NULL;
1.109 markus 2157: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2158: goto out;
1.68 markus 2159: }
1.211 djm 2160:
1.223 djm 2161: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2162: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2163: error_f("sshkey_fingerprint failed");
1.223 djm 2164: goto out;
1.68 markus 2165: }
1.355 djm 2166: debug_f("trying hostkey %s %s using sigalg %s",
2167: sshkey_ssh_name(private), fp, authctxt->active_ktype);
1.211 djm 2168:
1.84 markus 2169: /* figure out a name for the client host */
1.295 djm 2170: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2171: if (lname == NULL) {
1.331 djm 2172: error_f("cannot get local ipaddr/name");
1.223 djm 2173: goto out;
1.84 markus 2174: }
1.223 djm 2175:
2176: /* XXX sshbuf_put_stringf? */
2177: xasprintf(&chost, "%s.", lname);
1.331 djm 2178: debug2_f("chost %s", chost);
1.84 markus 2179:
1.68 markus 2180: /* construct data */
1.223 djm 2181: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2182: error_f("sshbuf_new failed");
1.223 djm 2183: goto out;
2184: }
2185: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2186: error_fr(r, "sshkey_to_blob");
1.223 djm 2187: goto out;
2188: }
1.346 djm 2189: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2190: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2191: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2192: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2193: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2194: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2195: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2196: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2197: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2198: error_fr(r, "buffer error");
1.223 djm 2199: goto out;
2200: }
2201:
1.68 markus 2202: #ifdef DEBUG_PK
1.223 djm 2203: sshbuf_dump(b, stderr);
1.68 markus 2204: #endif
1.294 djm 2205: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2206: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2207: error("sign using hostkey %s %s failed",
2208: sshkey_ssh_name(private), fp);
2209: goto out;
2210: }
2211: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2212: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2213: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2214: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2215: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2216: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2217: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2218: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2219: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2220: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2221: error_fr(r, "packet error");
1.223 djm 2222: goto out;
2223: }
2224: success = 1;
2225:
2226: out:
1.278 markus 2227: if (sig != NULL)
2228: freezero(sig, siglen);
1.223 djm 2229: free(keyblob);
2230: free(lname);
2231: free(fp);
1.197 djm 2232: free(chost);
1.223 djm 2233: sshkey_free(private);
2234: sshbuf_free(b);
1.68 markus 2235:
1.223 djm 2236: return success;
1.23 markus 2237: }
1.170 djm 2238:
1.20 markus 2239: /* find auth method */
2240:
2241: /*
2242: * given auth method name, if configurable options permit this method fill
2243: * in auth_ident field and return true, otherwise return false.
2244: */
1.76 itojun 2245: static int
1.20 markus 2246: authmethod_is_enabled(Authmethod *method)
2247: {
2248: if (method == NULL)
2249: return 0;
2250: /* return false if options indicate this method is disabled */
2251: if (method->enabled == NULL || *method->enabled == 0)
2252: return 0;
2253: /* return false if batch mode is enabled but method needs interactive mode */
2254: if (method->batch_flag != NULL && *method->batch_flag != 0)
2255: return 0;
2256: return 1;
2257: }
2258:
1.76 itojun 2259: static Authmethod *
1.20 markus 2260: authmethod_lookup(const char *name)
1.1 markus 2261: {
1.20 markus 2262: Authmethod *method = NULL;
2263: if (name != NULL)
2264: for (method = authmethods; method->name != NULL; method++)
2265: if (strcmp(name, method->name) == 0)
2266: return method;
2267: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2268: return NULL;
2269: }
1.1 markus 2270:
1.53 markus 2271: /* XXX internal state */
2272: static Authmethod *current = NULL;
2273: static char *supported = NULL;
2274: static char *preferred = NULL;
1.105 deraadt 2275:
1.20 markus 2276: /*
2277: * Given the authentication method list sent by the server, return the
2278: * next method we should try. If the server initially sends a nil list,
1.67 markus 2279: * use a built-in default list.
1.41 stevesk 2280: */
1.76 itojun 2281: static Authmethod *
1.20 markus 2282: authmethod_get(char *authlist)
2283: {
1.53 markus 2284: char *name = NULL;
1.97 markus 2285: u_int next;
1.41 stevesk 2286:
1.20 markus 2287: /* Use a suitable default if we're passed a nil list. */
2288: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2289: authlist = options.preferred_authentications;
1.20 markus 2290:
1.53 markus 2291: if (supported == NULL || strcmp(authlist, supported) != 0) {
2292: debug3("start over, passed a different list %s", authlist);
1.197 djm 2293: free(supported);
1.53 markus 2294: supported = xstrdup(authlist);
2295: preferred = options.preferred_authentications;
2296: debug3("preferred %s", preferred);
2297: current = NULL;
2298: } else if (current != NULL && authmethod_is_enabled(current))
2299: return current;
1.20 markus 2300:
1.53 markus 2301: for (;;) {
2302: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2303: debug("No more authentication methods to try.");
1.53 markus 2304: current = NULL;
2305: return NULL;
2306: }
2307: preferred += next;
1.23 markus 2308: debug3("authmethod_lookup %s", name);
1.53 markus 2309: debug3("remaining preferred: %s", preferred);
2310: if ((current = authmethod_lookup(name)) != NULL &&
2311: authmethod_is_enabled(current)) {
1.23 markus 2312: debug3("authmethod_is_enabled %s", name);
1.109 markus 2313: debug("Next authentication method: %s", name);
1.197 djm 2314: free(name);
1.53 markus 2315: return current;
1.23 markus 2316: }
1.198 dtucker 2317: free(name);
1.1 markus 2318: }
1.53 markus 2319: }
1.1 markus 2320:
1.79 stevesk 2321: static char *
1.53 markus 2322: authmethods_get(void)
2323: {
2324: Authmethod *method = NULL;
1.278 markus 2325: struct sshbuf *b;
1.93 markus 2326: char *list;
1.278 markus 2327: int r;
1.27 provos 2328:
1.278 markus 2329: if ((b = sshbuf_new()) == NULL)
1.331 djm 2330: fatal_f("sshbuf_new failed");
1.53 markus 2331: for (method = authmethods; method->name != NULL; method++) {
2332: if (authmethod_is_enabled(method)) {
1.278 markus 2333: if ((r = sshbuf_putf(b, "%s%s",
2334: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2335: fatal_fr(r, "buffer error");
1.53 markus 2336: }
2337: }
1.278 markus 2338: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2339: fatal_f("sshbuf_dup_string failed");
1.278 markus 2340: sshbuf_free(b);
1.93 markus 2341: return list;
1.1 markus 2342: }
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