Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.367
1.367 ! dtucker 1: /* $OpenBSD: sshconnect2.c,v 1.366 2023/03/09 07:11:05 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_ext_info(int, u_int32_t, struct ssh *);
355: static int input_userauth_success(int, u_int32_t, struct ssh *);
356: static int input_userauth_failure(int, u_int32_t, struct ssh *);
357: static int input_userauth_banner(int, u_int32_t, struct ssh *);
358: static int input_userauth_error(int, u_int32_t, struct ssh *);
359: static int input_userauth_info_req(int, u_int32_t, struct ssh *);
360: static int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
361: static int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
362:
363: static int userauth_none(struct ssh *);
364: static int userauth_pubkey(struct ssh *);
365: static int userauth_passwd(struct ssh *);
366: static int userauth_kbdint(struct ssh *);
367: static int userauth_hostbased(struct ssh *);
1.20 markus 368:
1.121 markus 369: #ifdef GSSAPI
1.302 djm 370: static int userauth_gssapi(struct ssh *);
371: static void userauth_gssapi_cleanup(struct ssh *);
372: static int input_gssapi_response(int type, u_int32_t, struct ssh *);
373: static int input_gssapi_token(int type, u_int32_t, struct ssh *);
374: static int input_gssapi_error(int, u_int32_t, struct ssh *);
375: static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
1.121 markus 376: #endif
377:
1.295 djm 378: void userauth(struct ssh *, char *);
1.51 markus 379:
1.303 djm 380: static void pubkey_cleanup(struct ssh *);
1.295 djm 381: static int sign_and_send_pubkey(struct ssh *ssh, Identity *);
1.352 djm 382: static void pubkey_prepare(struct ssh *, Authctxt *);
1.251 djm 383: static void pubkey_reset(Authctxt *);
1.259 markus 384: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 385:
386: static Authmethod *authmethod_get(char *authlist);
387: static Authmethod *authmethod_lookup(const char *name);
388: static char *authmethods_get(void);
1.20 markus 389:
390: Authmethod authmethods[] = {
1.121 markus 391: #ifdef GSSAPI
1.132 markus 392: {"gssapi-with-mic",
1.121 markus 393: userauth_gssapi,
1.302 djm 394: userauth_gssapi_cleanup,
1.121 markus 395: &options.gss_authentication,
396: NULL},
397: #endif
1.81 markus 398: {"hostbased",
399: userauth_hostbased,
1.170 djm 400: NULL,
1.81 markus 401: &options.hostbased_authentication,
402: NULL},
1.20 markus 403: {"publickey",
404: userauth_pubkey,
1.303 djm 405: NULL,
1.28 markus 406: &options.pubkey_authentication,
1.20 markus 407: NULL},
1.81 markus 408: {"keyboard-interactive",
409: userauth_kbdint,
1.170 djm 410: NULL,
1.81 markus 411: &options.kbd_interactive_authentication,
412: &options.batch_mode},
1.20 markus 413: {"password",
414: userauth_passwd,
1.170 djm 415: NULL,
1.20 markus 416: &options.password_authentication,
1.23 markus 417: &options.batch_mode},
418: {"none",
419: userauth_none,
420: NULL,
1.170 djm 421: NULL,
1.23 markus 422: NULL},
1.170 djm 423: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 424: };
425:
426: void
1.291 djm 427: ssh_userauth2(struct ssh *ssh, const char *local_user,
428: const char *server_user, char *host, Sensitive *sensitive)
1.20 markus 429: {
430: Authctxt authctxt;
1.231 markus 431: int r;
1.39 markus 432:
1.53 markus 433: if (options.preferred_authentications == NULL)
434: options.preferred_authentications = authmethods_get();
435:
1.20 markus 436: /* setup authentication context */
1.82 markus 437: memset(&authctxt, 0, sizeof(authctxt));
1.20 markus 438: authctxt.server_user = server_user;
1.68 markus 439: authctxt.local_user = local_user;
1.20 markus 440: authctxt.host = host;
441: authctxt.service = "ssh-connection"; /* service name */
442: authctxt.success = 0;
1.23 markus 443: authctxt.method = authmethod_lookup("none");
1.51 markus 444: authctxt.authlist = NULL;
1.121 markus 445: authctxt.methoddata = NULL;
1.100 markus 446: authctxt.sensitive = sensitive;
1.223 djm 447: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 448: authctxt.info_req_seen = 0;
1.292 djm 449: authctxt.attempt_kbdint = 0;
450: authctxt.attempt_passwd = 0;
1.302 djm 451: #if GSSAPI
452: authctxt.gss_supported_mechs = NULL;
453: authctxt.mech_tried = 0;
454: #endif
1.215 djm 455: authctxt.agent_fd = -1;
1.352 djm 456: pubkey_prepare(ssh, &authctxt);
1.291 djm 457: if (authctxt.method == NULL) {
1.331 djm 458: fatal_f("internal error: cannot send userauth none request");
1.291 djm 459: }
1.20 markus 460:
1.231 markus 461: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
462: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
463: (r = sshpkt_send(ssh)) != 0)
1.331 djm 464: fatal_fr(r, "send packet");
1.231 markus 465:
1.260 markus 466: ssh->authctxt = &authctxt;
1.231 markus 467: ssh_dispatch_init(ssh, &input_userauth_error);
468: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
469: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.263 markus 470: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.303 djm 471: pubkey_cleanup(ssh);
1.260 markus 472: ssh->authctxt = NULL;
1.20 markus 473:
1.231 markus 474: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 475:
1.248 dtucker 476: if (!authctxt.success)
477: fatal("Authentication failed.");
1.351 djm 478: if (ssh_packet_connection_is_on_socket(ssh)) {
479: verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
480: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
481: authctxt.method->name);
482: } else {
483: verbose("Authenticated to %s (via proxy) using \"%s\".", host,
484: authctxt.method->name);
485: }
1.20 markus 486: }
1.119 markus 487:
1.302 djm 488: static int
1.261 markus 489: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 490: {
491: int r;
492:
493: if (ssh_packet_remaining(ssh) > 0) {
494: char *reply;
495:
496: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
497: goto out;
498: debug2("service_accept: %s", reply);
499: free(reply);
500: } else {
501: debug2("buggy server: service_accept w/o service");
502: }
503: if ((r = sshpkt_get_end(ssh)) != 0)
504: goto out;
505: debug("SSH2_MSG_SERVICE_ACCEPT received");
506:
507: /* initial userauth request */
1.295 djm 508: userauth_none(ssh);
1.231 markus 509:
510: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
511: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
512: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
513: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
514: r = 0;
515: out:
516: return r;
517: }
518:
1.302 djm 519: static int
1.261 markus 520: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 521: {
1.261 markus 522: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 523: }
524:
1.20 markus 525: void
1.295 djm 526: userauth(struct ssh *ssh, char *authlist)
1.51 markus 527: {
1.295 djm 528: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 529:
1.170 djm 530: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 531: authctxt->method->cleanup(ssh);
1.170 djm 532:
1.197 djm 533: free(authctxt->methoddata);
534: authctxt->methoddata = NULL;
1.51 markus 535: if (authlist == NULL) {
536: authlist = authctxt->authlist;
537: } else {
1.197 djm 538: free(authctxt->authlist);
1.51 markus 539: authctxt->authlist = authlist;
540: }
541: for (;;) {
542: Authmethod *method = authmethod_get(authlist);
543: if (method == NULL)
1.264 dtucker 544: fatal("%s@%s: Permission denied (%s).",
545: authctxt->server_user, authctxt->host, authlist);
1.51 markus 546: authctxt->method = method;
1.119 markus 547:
548: /* reset the per method handler */
1.278 markus 549: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 550: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
551:
552: /* and try new method */
1.295 djm 553: if (method->userauth(ssh) != 0) {
1.51 markus 554: debug2("we sent a %s packet, wait for reply", method->name);
555: break;
556: } else {
557: debug2("we did not send a packet, disable method");
558: method->enabled = NULL;
559: }
560: }
561: }
1.105 deraadt 562:
1.302 djm 563: static int
1.261 markus 564: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 565: {
1.331 djm 566: fatal_f("bad message during authentication: type %d", type);
1.218 markus 567: return 0;
1.35 markus 568: }
1.105 deraadt 569:
1.302 djm 570: static int
1.261 markus 571: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 572: {
1.295 djm 573: char *msg = NULL;
1.294 djm 574: size_t len;
575: int r;
1.126 deraadt 576:
1.331 djm 577: debug3_f("entering");
1.294 djm 578: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 579: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 580: goto out;
1.246 djm 581: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
582: fmprintf(stderr, "%s", msg);
1.294 djm 583: r = 0;
584: out:
1.246 djm 585: free(msg);
1.294 djm 586: return r;
1.20 markus 587: }
1.105 deraadt 588:
1.302 djm 589: static int
1.261 markus 590: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 591: {
1.260 markus 592: Authctxt *authctxt = ssh->authctxt;
1.172 djm 593:
1.20 markus 594: if (authctxt == NULL)
1.331 djm 595: fatal_f("no authentication context");
1.197 djm 596: free(authctxt->authlist);
597: authctxt->authlist = NULL;
1.172 djm 598: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 599: authctxt->method->cleanup(ssh);
1.197 djm 600: free(authctxt->methoddata);
601: authctxt->methoddata = NULL;
1.20 markus 602: authctxt->success = 1; /* break out */
1.218 markus 603: return 0;
1.20 markus 604: }
1.105 deraadt 605:
1.302 djm 606: #if 0
607: static int
1.261 markus 608: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 609: {
1.260 markus 610: Authctxt *authctxt = ssh->authctxt;
1.172 djm 611:
612: if (authctxt == NULL)
1.331 djm 613: fatal_f("no authentication context");
1.172 djm 614:
615: fatal("Unexpected authentication success during %s.",
616: authctxt->method->name);
1.218 markus 617: return 0;
1.172 djm 618: }
1.302 djm 619: #endif
1.172 djm 620:
1.302 djm 621: static int
1.261 markus 622: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 623: {
1.260 markus 624: Authctxt *authctxt = ssh->authctxt;
1.20 markus 625: char *authlist = NULL;
1.278 markus 626: u_char partial;
1.20 markus 627:
628: if (authctxt == NULL)
629: fatal("input_userauth_failure: no authentication context");
630:
1.307 dtucker 631: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
632: sshpkt_get_u8(ssh, &partial) != 0 ||
633: sshpkt_get_end(ssh) != 0)
1.278 markus 634: goto out;
1.20 markus 635:
1.193 markus 636: if (partial != 0) {
1.351 djm 637: verbose("Authenticated using \"%s\" with partial success.",
638: authctxt->method->name);
1.193 markus 639: /* reset state */
1.251 djm 640: pubkey_reset(authctxt);
1.193 markus 641: }
1.109 markus 642: debug("Authentications that can continue: %s", authlist);
1.20 markus 643:
1.295 djm 644: userauth(ssh, authlist);
1.278 markus 645: authlist = NULL;
646: out:
647: free(authlist);
1.218 markus 648: return 0;
1.51 markus 649: }
1.169 djm 650:
1.287 djm 651: /*
652: * Format an identity for logging including filename, key type, fingerprint
653: * and location (agent, etc.). Caller must free.
654: */
655: static char *
656: format_identity(Identity *id)
657: {
658: char *fp = NULL, *ret = NULL;
1.309 djm 659: const char *note = "";
1.287 djm 660:
661: if (id->key != NULL) {
1.347 djm 662: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1.287 djm 663: SSH_FP_DEFAULT);
664: }
1.309 djm 665: if (id->key) {
666: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
667: note = " token";
1.311 markus 668: else if (sshkey_is_sk(id->key))
1.319 naddy 669: note = " authenticator";
1.309 djm 670: }
1.287 djm 671: xasprintf(&ret, "%s %s%s%s%s%s%s",
672: id->filename,
673: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
674: fp ? fp : "",
1.309 djm 675: id->userprovided ? " explicit" : "", note,
1.287 djm 676: id->agent_fd != -1 ? " agent" : "");
677: free(fp);
678: return ret;
679: }
680:
1.302 djm 681: static int
1.261 markus 682: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 683: {
1.260 markus 684: Authctxt *authctxt = ssh->authctxt;
1.259 markus 685: struct sshkey *key = NULL;
1.117 markus 686: Identity *id = NULL;
1.287 djm 687: int pktype, found = 0, sent = 0;
1.278 markus 688: size_t blen;
1.287 djm 689: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 690: u_char *pkblob = NULL;
691: int r;
1.51 markus 692:
693: if (authctxt == NULL)
694: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 695:
1.278 markus 696: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
697: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
698: (r = sshpkt_get_end(ssh)) != 0)
699: goto done;
1.51 markus 700:
1.278 markus 701: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 702: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 703: goto done;
704: }
1.278 markus 705: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 706: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 707: goto done;
708: }
709: if (key->type != pktype) {
710: error("input_userauth_pk_ok: type mismatch "
711: "for decoded key (received %d, expected %d)",
712: key->type, pktype);
713: goto done;
714: }
715:
1.127 markus 716: /*
717: * search keys in the reverse order, because last candidate has been
718: * moved to the end of the queue. this also avoids confusion by
719: * duplicate keys
720: */
1.136 henning 721: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 722: if (sshkey_equal(key, id->key)) {
1.287 djm 723: found = 1;
1.51 markus 724: break;
725: }
1.117 markus 726: }
1.287 djm 727: if (!found || id == NULL) {
728: fp = sshkey_fingerprint(key, options.fingerprint_hash,
729: SSH_FP_DEFAULT);
1.331 djm 730: error_f("server replied with unknown key: %s %s",
1.287 djm 731: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
732: goto done;
733: }
734: ident = format_identity(id);
735: debug("Server accepts key: %s", ident);
1.295 djm 736: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 737: r = 0;
738: done:
739: sshkey_free(key);
1.287 djm 740: free(ident);
741: free(fp);
1.197 djm 742: free(pkalg);
743: free(pkblob);
1.51 markus 744:
1.106 deraadt 745: /* try another method if we did not send a packet */
1.278 markus 746: if (r == 0 && sent == 0)
1.295 djm 747: userauth(ssh, NULL);
1.278 markus 748: return r;
1.20 markus 749: }
1.121 markus 750:
751: #ifdef GSSAPI
1.302 djm 752: static int
1.295 djm 753: userauth_gssapi(struct ssh *ssh)
1.121 markus 754: {
1.295 djm 755: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 756: Gssctxt *gssctxt = NULL;
757: OM_uint32 min;
1.278 markus 758: int r, ok = 0;
1.302 djm 759: gss_OID mech = NULL;
1.121 markus 760:
761: /* Try one GSSAPI method at a time, rather than sending them all at
762: * once. */
763:
1.302 djm 764: if (authctxt->gss_supported_mechs == NULL)
765: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 766:
1.302 djm 767: /* Check to see whether the mechanism is usable before we offer it */
768: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
769: !ok) {
770: mech = &authctxt->gss_supported_mechs->
771: elements[authctxt->mech_tried];
1.121 markus 772: /* My DER encoding requires length<128 */
1.302 djm 773: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
774: mech, authctxt->host)) {
1.121 markus 775: ok = 1; /* Mechanism works */
776: } else {
1.302 djm 777: authctxt->mech_tried++;
1.121 markus 778: }
779: }
780:
1.302 djm 781: if (!ok || mech == NULL)
1.139 djm 782: return 0;
1.121 markus 783:
784: authctxt->methoddata=(void *)gssctxt;
785:
1.278 markus 786: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
787: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
788: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
789: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
790: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 791: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 792: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 793: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
794: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 795: (r = sshpkt_send(ssh)) != 0)
1.331 djm 796: fatal_fr(r, "send packet");
1.278 markus 797:
798: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
799: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
800: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
801: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 802:
1.302 djm 803: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 804:
805: return 1;
806: }
807:
1.302 djm 808: static void
809: userauth_gssapi_cleanup(struct ssh *ssh)
810: {
811: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
812: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
813:
814: ssh_gssapi_delete_ctx(&gssctxt);
815: authctxt->methoddata = NULL;
816:
817: free(authctxt->gss_supported_mechs);
818: authctxt->gss_supported_mechs = NULL;
819: }
820:
1.130 markus 821: static OM_uint32
1.262 djm 822: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 823: {
1.260 markus 824: Authctxt *authctxt = ssh->authctxt;
1.130 markus 825: Gssctxt *gssctxt = authctxt->methoddata;
826: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 827: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
828: gss_buffer_desc gssbuf;
1.132 markus 829: OM_uint32 status, ms, flags;
1.278 markus 830: int r;
1.133 djm 831:
1.130 markus 832: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 833: recv_tok, &send_tok, &flags);
1.130 markus 834:
835: if (send_tok.length > 0) {
1.278 markus 836: u_char type = GSS_ERROR(status) ?
837: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
838: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
839:
840: if ((r = sshpkt_start(ssh, type)) != 0 ||
841: (r = sshpkt_put_string(ssh, send_tok.value,
842: send_tok.length)) != 0 ||
843: (r = sshpkt_send(ssh)) != 0)
1.331 djm 844: fatal_fr(r, "send %u packet", type);
1.133 djm 845:
1.130 markus 846: gss_release_buffer(&ms, &send_tok);
847: }
1.133 djm 848:
1.130 markus 849: if (status == GSS_S_COMPLETE) {
1.132 markus 850: /* send either complete or MIC, depending on mechanism */
851: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 852: if ((r = sshpkt_start(ssh,
853: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
854: (r = sshpkt_send(ssh)) != 0)
1.331 djm 855: fatal_fr(r, "send completion");
1.132 markus 856: } else {
1.278 markus 857: struct sshbuf *b;
858:
859: if ((b = sshbuf_new()) == NULL)
1.331 djm 860: fatal_f("sshbuf_new failed");
1.278 markus 861: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 djm 862: authctxt->service, "gssapi-with-mic",
863: ssh->kex->session_id);
1.132 markus 864:
1.278 markus 865: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 866: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 867: gssbuf.length = sshbuf_len(b);
1.133 djm 868:
1.132 markus 869: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 870:
1.132 markus 871: if (!GSS_ERROR(status)) {
1.278 markus 872: if ((r = sshpkt_start(ssh,
873: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
874: (r = sshpkt_put_string(ssh, mic.value,
875: mic.length)) != 0 ||
876: (r = sshpkt_send(ssh)) != 0)
1.331 djm 877: fatal_fr(r, "send MIC");
1.132 markus 878: }
1.133 djm 879:
1.278 markus 880: sshbuf_free(b);
1.132 markus 881: gss_release_buffer(&ms, &mic);
1.133 djm 882: }
1.130 markus 883: }
1.133 djm 884:
1.130 markus 885: return status;
886: }
887:
1.302 djm 888: static int
1.261 markus 889: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 890: {
1.260 markus 891: Authctxt *authctxt = ssh->authctxt;
1.121 markus 892: Gssctxt *gssctxt;
1.278 markus 893: size_t oidlen;
894: u_char *oidv = NULL;
895: int r;
1.121 markus 896:
897: if (authctxt == NULL)
898: fatal("input_gssapi_response: no authentication context");
899: gssctxt = authctxt->methoddata;
900:
901: /* Setup our OID */
1.278 markus 902: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
903: goto done;
1.121 markus 904:
1.129 markus 905: if (oidlen <= 2 ||
906: oidv[0] != SSH_GSS_OIDTYPE ||
907: oidv[1] != oidlen - 2) {
908: debug("Badly encoded mechanism OID received");
1.296 djm 909: userauth(ssh, NULL);
1.278 markus 910: goto ok;
1.121 markus 911: }
1.129 markus 912:
913: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
914: fatal("Server returned different OID than expected");
1.121 markus 915:
1.278 markus 916: if ((r = sshpkt_get_end(ssh)) != 0)
917: goto done;
1.121 markus 918:
1.262 djm 919: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 920: /* Start again with next method on list */
921: debug("Trying to start again");
1.296 djm 922: userauth(ssh, NULL);
1.278 markus 923: goto ok;
1.121 markus 924: }
1.278 markus 925: ok:
926: r = 0;
927: done:
928: free(oidv);
929: return r;
1.121 markus 930: }
931:
1.302 djm 932: static int
1.261 markus 933: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 934: {
1.260 markus 935: Authctxt *authctxt = ssh->authctxt;
1.121 markus 936: gss_buffer_desc recv_tok;
1.278 markus 937: u_char *p = NULL;
938: size_t len;
1.130 markus 939: OM_uint32 status;
1.278 markus 940: int r;
1.121 markus 941:
942: if (authctxt == NULL)
943: fatal("input_gssapi_response: no authentication context");
944:
1.278 markus 945: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
946: (r = sshpkt_get_end(ssh)) != 0)
947: goto out;
1.121 markus 948:
1.278 markus 949: recv_tok.value = p;
950: recv_tok.length = len;
1.262 djm 951: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 952:
1.278 markus 953: /* Start again with the next method in the list */
1.121 markus 954: if (GSS_ERROR(status)) {
1.296 djm 955: userauth(ssh, NULL);
1.278 markus 956: /* ok */
1.121 markus 957: }
1.278 markus 958: r = 0;
959: out:
960: free(p);
961: return r;
1.121 markus 962: }
963:
1.302 djm 964: static int
1.261 markus 965: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 966: {
1.260 markus 967: Authctxt *authctxt = ssh->authctxt;
1.121 markus 968: Gssctxt *gssctxt;
969: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
970: gss_buffer_desc recv_tok;
1.194 djm 971: OM_uint32 ms;
1.278 markus 972: u_char *p = NULL;
973: size_t len;
974: int r;
1.121 markus 975:
976: if (authctxt == NULL)
977: fatal("input_gssapi_response: no authentication context");
978: gssctxt = authctxt->methoddata;
979:
1.278 markus 980: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
981: (r = sshpkt_get_end(ssh)) != 0) {
982: free(p);
983: return r;
984: }
1.121 markus 985:
986: /* Stick it into GSSAPI and see what it says */
1.278 markus 987: recv_tok.value = p;
988: recv_tok.length = len;
1.194 djm 989: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 990: &recv_tok, &send_tok, NULL);
1.278 markus 991: free(p);
1.121 markus 992: gss_release_buffer(&ms, &send_tok);
993:
994: /* Server will be returning a failed packet after this one */
1.220 djm 995: return 0;
1.121 markus 996: }
997:
1.302 djm 998: static int
1.261 markus 999: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 1000: {
1.278 markus 1001: char *msg = NULL;
1002: char *lang = NULL;
1003: int r;
1.121 markus 1004:
1.278 markus 1005: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1006: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1007: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1008: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1009: goto out;
1010: r = sshpkt_get_end(ssh);
1.143 stevesk 1011: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1012: out:
1.197 djm 1013: free(msg);
1014: free(lang);
1.278 markus 1015: return r;
1.121 markus 1016: }
1017: #endif /* GSSAPI */
1.20 markus 1018:
1.302 djm 1019: static int
1.295 djm 1020: userauth_none(struct ssh *ssh)
1.23 markus 1021: {
1.295 djm 1022: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1023: int r;
1024:
1.23 markus 1025: /* initial userauth request */
1.278 markus 1026: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1027: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1028: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1029: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1030: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1031: fatal_fr(r, "send packet");
1.23 markus 1032: return 1;
1033: }
1034:
1.302 djm 1035: static int
1.295 djm 1036: userauth_passwd(struct ssh *ssh)
1.1 markus 1037: {
1.295 djm 1038: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1039: char *password, *prompt = NULL;
1.175 dtucker 1040: const char *host = options.host_key_alias ? options.host_key_alias :
1041: authctxt->host;
1.278 markus 1042: int r;
1.6 markus 1043:
1.292 djm 1044: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1045: return 0;
1.13 todd 1046:
1.292 djm 1047: if (authctxt->attempt_passwd != 1)
1.13 todd 1048: error("Permission denied, please try again.");
1.1 markus 1049:
1.290 djm 1050: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1051: password = read_passphrase(prompt, 0);
1.278 markus 1052: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1053: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1054: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1055: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1056: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1057: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1058: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1059: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1060: fatal_fr(r, "send packet");
1.99 markus 1061:
1.290 djm 1062: free(prompt);
1063: if (password != NULL)
1.278 markus 1064: freezero(password, strlen(password));
1065:
1066: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1067: &input_userauth_passwd_changereq);
1068:
1.1 markus 1069: return 1;
1070: }
1.169 djm 1071:
1.99 markus 1072: /*
1073: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1074: */
1.302 djm 1075: static int
1.261 markus 1076: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1077: {
1.260 markus 1078: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1079: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1080: char prompt[256];
1.252 djm 1081: const char *host;
1.278 markus 1082: int r;
1.99 markus 1083:
1084: debug2("input_userauth_passwd_changereq");
1085:
1086: if (authctxt == NULL)
1087: fatal("input_userauth_passwd_changereq: "
1088: "no authentication context");
1.252 djm 1089: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1090:
1.278 markus 1091: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1092: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1093: goto out;
1.99 markus 1094: if (strlen(info) > 0)
1.116 itojun 1095: logit("%s", info);
1.278 markus 1096: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1097: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1098: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1099: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1100: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1101: goto out;
1102:
1.104 deraadt 1103: snprintf(prompt, sizeof(prompt),
1.99 markus 1104: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1105: authctxt->server_user, host);
1.99 markus 1106: password = read_passphrase(prompt, 0);
1.278 markus 1107: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1108: goto out;
1109:
1110: freezero(password, strlen(password));
1.99 markus 1111: password = NULL;
1112: while (password == NULL) {
1.104 deraadt 1113: snprintf(prompt, sizeof(prompt),
1.99 markus 1114: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1115: authctxt->server_user, host);
1.99 markus 1116: password = read_passphrase(prompt, RP_ALLOW_EOF);
1117: if (password == NULL) {
1118: /* bail out */
1.278 markus 1119: r = 0;
1120: goto out;
1.99 markus 1121: }
1.104 deraadt 1122: snprintf(prompt, sizeof(prompt),
1.99 markus 1123: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1124: authctxt->server_user, host);
1.99 markus 1125: retype = read_passphrase(prompt, 0);
1126: if (strcmp(password, retype) != 0) {
1.278 markus 1127: freezero(password, strlen(password));
1.116 itojun 1128: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1129: password = NULL;
1130: }
1.278 markus 1131: freezero(retype, strlen(retype));
1.99 markus 1132: }
1.278 markus 1133: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1134: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1135: (r = sshpkt_send(ssh)) != 0)
1136: goto out;
1.104 deraadt 1137:
1.278 markus 1138: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1139: &input_userauth_passwd_changereq);
1.278 markus 1140: r = 0;
1141: out:
1142: if (password)
1143: freezero(password, strlen(password));
1144: free(info);
1145: free(lang);
1146: return r;
1.117 markus 1147: }
1148:
1.272 djm 1149: /*
1150: * Select an algorithm for publickey signatures.
1151: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1152: *
1153: * Call with ssh==NULL to ignore server-sig-algs extension list and
1154: * only attempt with the key's base signature type.
1155: */
1156: static char *
1157: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1158: {
1.274 djm 1159: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.348 djm 1160: const char *server_sig_algs;
1.231 markus 1161:
1.272 djm 1162: /*
1163: * The signature algorithm will only differ from the key algorithm
1164: * for RSA keys/certs and when the server advertises support for
1165: * newer (SHA2) algorithms.
1166: */
1167: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1168: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1169: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1170: /* Filter base key signature alg against our configuration */
1.279 markus 1171: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1172: options.pubkey_accepted_algos, NULL);
1.231 markus 1173: }
1174:
1.272 djm 1175: /*
1.348 djm 1176: * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1177: * fails to advertise it via SSH2_MSG_EXT_INFO.
1178: */
1179: server_sig_algs = ssh->kex->server_sig_algs;
1180: if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1181: server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1182:
1183: /*
1.272 djm 1184: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1185: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1186: * that also appears in the supported signature algorithms list from
1187: * the server.
1188: */
1.342 dtucker 1189: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1190: while ((cp = strsep(&allowed, ",")) != NULL) {
1191: if (sshkey_type_from_name(cp) != key->type)
1192: continue;
1.323 djm 1193: tmp = match_list(sshkey_sigalg_by_name(cp),
1.348 djm 1194: server_sig_algs, NULL);
1.274 djm 1195: if (tmp != NULL)
1196: alg = xstrdup(cp);
1197: free(tmp);
1.272 djm 1198: if (alg != NULL)
1199: break;
1.269 djm 1200: }
1.272 djm 1201: free(oallowed);
1202: return alg;
1.269 djm 1203: }
1204:
1.117 markus 1205: static int
1.214 djm 1206: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1207: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1208: {
1.309 djm 1209: struct sshkey *sign_key = NULL, *prv = NULL;
1.360 djm 1210: int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1211: struct notifier_ctx *notifier = NULL;
1.325 djm 1212: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1213:
1214: *sigp = NULL;
1215: *lenp = 0;
1.99 markus 1216:
1.272 djm 1217: /* The agent supports this key. */
1.269 djm 1218: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1219: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1220: data, datalen, alg, compat);
1.269 djm 1221: }
1.214 djm 1222:
1.117 markus 1223: /*
1.272 djm 1224: * We have already loaded the private key or the private key is
1225: * stored in external hardware.
1.117 markus 1226: */
1.255 djm 1227: if (id->key != NULL &&
1.272 djm 1228: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1229: sign_key = id->key;
1.360 djm 1230: is_agent = 1;
1.309 djm 1231: } else {
1232: /* Load the private key from the file. */
1233: if ((prv = load_identity_file(id)) == NULL)
1234: return SSH_ERR_KEY_NOT_FOUND;
1235: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1236: error_f("private key %s contents do not match public",
1.347 djm 1237: id->filename);
1.309 djm 1238: r = SSH_ERR_KEY_NOT_FOUND;
1239: goto out;
1240: }
1241: sign_key = prv;
1.360 djm 1242: }
1.341 djm 1243: retry_pin:
1.360 djm 1244: /* Prompt for touch for non-agent FIDO keys that request UP */
1245: if (!is_agent && sshkey_is_sk(sign_key) &&
1246: (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1247: /* XXX should batch mode just skip these? */
1248: if ((fp = sshkey_fingerprint(sign_key,
1249: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1250: fatal_f("fingerprint failed");
1251: notifier = notify_start(options.batch_mode,
1252: "Confirm user presence for key %s %s",
1253: sshkey_type(sign_key), fp);
1254: free(fp);
1.272 djm 1255: }
1.310 djm 1256: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1257: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1258: debug_fr(r, "sshkey_sign");
1.360 djm 1259: if (!retried && pin == NULL && !is_agent &&
1260: sshkey_is_sk(sign_key) &&
1.341 djm 1261: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1262: notify_complete(notifier, NULL);
1263: notifier = NULL;
1.360 djm 1264: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1265: sshkey_type(sign_key), id->filename);
1266: pin = read_passphrase(prompt, 0);
1.341 djm 1267: retried = 1;
1268: goto retry_pin;
1269: }
1.309 djm 1270: goto out;
1271: }
1.341 djm 1272:
1.309 djm 1273: /*
1274: * PKCS#11 tokens may not support all signature algorithms,
1275: * so check what we get back.
1276: */
1277: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1278: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1279: goto out;
1.265 djm 1280: }
1.309 djm 1281: /* success */
1282: r = 0;
1283: out:
1.325 djm 1284: free(prompt);
1285: if (pin != NULL)
1286: freezero(pin, strlen(pin));
1.341 djm 1287: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1288: sshkey_free(prv);
1.269 djm 1289: return r;
1.51 markus 1290: }
1291:
1.76 itojun 1292: static int
1.255 djm 1293: id_filename_matches(Identity *id, Identity *private_id)
1294: {
1.356 djm 1295: static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
1.255 djm 1296: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1297: size_t i, slen;
1298:
1299: if (strcmp(id->filename, private_id->filename) == 0)
1300: return 1;
1301: for (i = 0; suffixes[i]; i++) {
1302: slen = strlen(suffixes[i]);
1303: if (len > slen && plen == len - slen &&
1304: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1305: memcmp(id->filename, private_id->filename, plen) == 0)
1306: return 1;
1307: }
1308: return 0;
1309: }
1310:
1311: static int
1.295 djm 1312: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1313: {
1.295 djm 1314: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1315: struct sshbuf *b = NULL;
1316: Identity *private_id, *sign_id = NULL;
1317: u_char *signature = NULL;
1318: size_t slen = 0, skip = 0;
1319: int r, fallback_sigtype, sent = 0;
1320: char *alg = NULL, *fp = NULL;
1.353 djm 1321: const char *loc = "", *method = "publickey";
1.354 djm 1322: int hostbound = 0;
1.353 djm 1323:
1324: /* prefer host-bound pubkey signatures if supported by server */
1.354 djm 1325: if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
1326: (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
1327: hostbound = 1;
1.353 djm 1328: method = "publickey-hostbound-v00@openssh.com";
1.354 djm 1329: }
1.1 markus 1330:
1.222 djm 1331: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1332: SSH_FP_DEFAULT)) == NULL)
1333: return 0;
1.51 markus 1334:
1.354 djm 1335: debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
1.1 markus 1336:
1.227 djm 1337: /*
1338: * If the key is an certificate, try to find a matching private key
1339: * and use it to complete the signature.
1.241 djm 1340: * If no such private key exists, fall back to trying the certificate
1341: * key itself in case it has a private half already loaded.
1.272 djm 1342: * This will try to set sign_id to the private key that will perform
1343: * the signature.
1.227 djm 1344: */
1.272 djm 1345: if (sshkey_is_cert(id->key)) {
1.227 djm 1346: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1347: if (sshkey_equal_public(id->key, private_id->key) &&
1348: id->key->type != private_id->key->type) {
1.272 djm 1349: sign_id = private_id;
1.227 djm 1350: break;
1351: }
1352: }
1.255 djm 1353: /*
1354: * Exact key matches are preferred, but also allow
1355: * filename matches for non-PKCS#11/agent keys that
1356: * didn't load public keys. This supports the case
1357: * of keeping just a private key file and public
1358: * certificate on disk.
1359: */
1.272 djm 1360: if (sign_id == NULL &&
1361: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1362: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1363: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1364: if (private_id->key == NULL &&
1365: id_filename_matches(id, private_id)) {
1.272 djm 1366: sign_id = private_id;
1.255 djm 1367: break;
1368: }
1369: }
1370: }
1.272 djm 1371: if (sign_id != NULL) {
1.331 djm 1372: debug2_f("using private key \"%s\"%s for "
1.349 djm 1373: "certificate", sign_id->filename,
1374: sign_id->agent_fd != -1 ? " from agent" : "");
1.227 djm 1375: } else {
1.331 djm 1376: debug_f("no separate private key for certificate "
1377: "\"%s\"", id->filename);
1.227 djm 1378: }
1379: }
1380:
1.272 djm 1381: /*
1382: * If the above didn't select another identity to do the signing
1383: * then default to the one we started with.
1384: */
1385: if (sign_id == NULL)
1386: sign_id = id;
1387:
1388: /* assemble and sign data */
1389: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1390: free(alg);
1391: slen = 0;
1392: signature = NULL;
1393: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1394: id->key)) == NULL) {
1.331 djm 1395: error_f("no mutual signature supported");
1.272 djm 1396: goto out;
1397: }
1.331 djm 1398: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1399:
1400: sshbuf_free(b);
1401: if ((b = sshbuf_new()) == NULL)
1.331 djm 1402: fatal_f("sshbuf_new failed");
1.345 djm 1403: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 djm 1404: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1405: fatal_fr(r, "sshbuf_putb");
1.272 djm 1406: } else {
1.346 djm 1407: if ((r = sshbuf_put_stringb(b,
1408: ssh->kex->session_id)) != 0)
1409: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1410: }
1.278 markus 1411: skip = sshbuf_len(b);
1.272 djm 1412: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1413: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1414: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.353 djm 1415: (r = sshbuf_put_cstring(b, method)) != 0 ||
1.272 djm 1416: (r = sshbuf_put_u8(b, 1)) != 0 ||
1417: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1418: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1419: fatal_fr(r, "assemble signed data");
1.272 djm 1420: }
1.354 djm 1421: if (hostbound) {
1.353 djm 1422: if (ssh->kex->initial_hostkey == NULL) {
1423: fatal_f("internal error: initial hostkey "
1424: "not recorded");
1425: }
1426: if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
1427: fatal_fr(r, "assemble %s hostkey", method);
1428: }
1.272 djm 1429: /* generate signature */
1430: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1431: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1432: if (r == 0)
1433: break;
1434: else if (r == SSH_ERR_KEY_NOT_FOUND)
1435: goto out; /* soft failure */
1436: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1437: !fallback_sigtype) {
1438: if (sign_id->agent_fd != -1)
1439: loc = "agent ";
1440: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1441: loc = "token ";
1442: logit("%skey %s %s returned incorrect signature type",
1443: loc, sshkey_type(id->key), fp);
1444: continue;
1445: }
1.331 djm 1446: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1447: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1448: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1449: goto out;
1.17 markus 1450: }
1.272 djm 1451: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1452: fatal_f("no signature");
1.51 markus 1453:
1.1 markus 1454: /* append signature */
1.272 djm 1455: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1456: fatal_fr(r, "append signature");
1.1 markus 1457:
1.272 djm 1458: #ifdef DEBUG_PK
1459: sshbuf_dump(b, stderr);
1460: #endif
1.1 markus 1461: /* skip session id and packet type */
1.272 djm 1462: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1463: fatal_fr(r, "consume");
1.1 markus 1464:
1465: /* put remaining data from buffer into packet */
1.272 djm 1466: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1467: (r = sshpkt_putb(ssh, b)) != 0 ||
1468: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1469: fatal_fr(r, "enqueue request");
1.272 djm 1470:
1471: /* success */
1472: sent = 1;
1.17 markus 1473:
1.272 djm 1474: out:
1475: free(fp);
1476: free(alg);
1477: sshbuf_free(b);
1478: freezero(signature, slen);
1479: return sent;
1.16 markus 1480: }
1481:
1.76 itojun 1482: static int
1.295 djm 1483: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1484: {
1.295 djm 1485: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1486: u_char *blob = NULL;
1487: char *alg = NULL;
1.278 markus 1488: size_t bloblen;
1489: u_int have_sig = 0;
1490: int sent = 0, r;
1.20 markus 1491:
1.272 djm 1492: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1493: debug_f("no mutual signature algorithm");
1.272 djm 1494: goto out;
1495: }
1.16 markus 1496:
1.278 markus 1497: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1498: /* we cannot handle this key */
1.331 djm 1499: debug3_f("cannot handle key");
1.272 djm 1500: goto out;
1.16 markus 1501: }
1.51 markus 1502: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1503: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1504:
1.278 markus 1505: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1506: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1507: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1508: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1509: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1510: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1511: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1512: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1513: fatal_fr(r, "send packet");
1.272 djm 1514: sent = 1;
1.278 markus 1515:
1516: out:
1.272 djm 1517: free(alg);
1.197 djm 1518: free(blob);
1.272 djm 1519: return sent;
1.51 markus 1520: }
1521:
1.259 markus 1522: static struct sshkey *
1.229 jcs 1523: load_identity_file(Identity *id)
1.51 markus 1524: {
1.259 markus 1525: struct sshkey *private = NULL;
1.229 jcs 1526: char prompt[300], *passphrase, *comment;
1.308 dtucker 1527: int r, quit = 0, i;
1.52 markus 1528: struct stat st;
1.16 markus 1529:
1.306 deraadt 1530: if (stat(id->filename, &st) == -1) {
1.330 djm 1531: do_log2(id->userprovided ?
1532: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1533: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1534: return NULL;
1535: }
1.214 djm 1536: snprintf(prompt, sizeof prompt,
1.229 jcs 1537: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1538: for (i = 0; i <= options.number_of_password_prompts; i++) {
1539: if (i == 0)
1540: passphrase = "";
1541: else {
1.20 markus 1542: passphrase = read_passphrase(prompt, 0);
1.214 djm 1543: if (*passphrase == '\0') {
1.20 markus 1544: debug2("no passphrase given, try next key");
1.214 djm 1545: free(passphrase);
1546: break;
1547: }
1548: }
1.229 jcs 1549: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1550: passphrase, &private, &comment))) {
1.214 djm 1551: case 0:
1552: break;
1553: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1554: if (options.batch_mode) {
1555: quit = 1;
1556: break;
1557: }
1.215 djm 1558: if (i != 0)
1559: debug2("bad passphrase given, try again...");
1.214 djm 1560: break;
1561: case SSH_ERR_SYSTEM_ERROR:
1562: if (errno == ENOENT) {
1.331 djm 1563: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1564: quit = 1;
1.214 djm 1565: break;
1.20 markus 1566: }
1.214 djm 1567: /* FALLTHROUGH */
1568: default:
1.331 djm 1569: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1570: quit = 1;
1571: break;
1572: }
1.311 markus 1573: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1574: options.sk_provider == NULL) {
1.319 naddy 1575: debug("key \"%s\" is an authenticator-hosted key, "
1576: "but no provider specified", id->filename);
1.309 djm 1577: sshkey_free(private);
1578: private = NULL;
1579: quit = 1;
1580: }
1.361 djm 1581: if (!quit && (r = sshkey_check_rsa_length(private,
1582: options.required_rsa_size)) != 0) {
1583: debug_fr(r, "Skipping key %s", id->filename);
1584: sshkey_free(private);
1585: private = NULL;
1586: quit = 1;
1587: }
1.230 djm 1588: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1589: !(id->key && id->isprivate))
1590: maybe_add_key_to_agent(id->filename, private, comment,
1591: passphrase);
1.278 markus 1592: if (i > 0)
1593: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1594: free(comment);
1.214 djm 1595: if (private != NULL || quit)
1596: break;
1.16 markus 1597: }
1.51 markus 1598: return private;
1599: }
1600:
1.272 djm 1601: static int
1602: key_type_allowed_by_config(struct sshkey *key)
1603: {
1604: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1605: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1606: return 1;
1607:
1608: /* RSA keys/certs might be allowed by alternate signature types */
1609: switch (key->type) {
1610: case KEY_RSA:
1611: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1612: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1613: return 1;
1614: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1615: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1616: return 1;
1617: break;
1618: case KEY_RSA_CERT:
1619: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1620: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1621: return 1;
1622: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1623: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1624: return 1;
1625: break;
1626: }
1627: return 0;
1628: }
1629:
1.352 djm 1630: /* obtain a list of keys from the agent */
1631: static int
1632: get_agent_identities(struct ssh *ssh, int *agent_fdp,
1633: struct ssh_identitylist **idlistp)
1634: {
1635: int r, agent_fd;
1636: struct ssh_identitylist *idlist;
1637:
1638: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1639: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1640: debug_fr(r, "ssh_get_authentication_socket");
1641: return r;
1642: }
1643: if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
1644: ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
1645: debug_f("bound agent to hostkey");
1646: else
1647: debug2_fr(r, "ssh_agent_bind_hostkey");
1648:
1649: if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1650: debug_fr(r, "ssh_fetch_identitylist");
1651: close(agent_fd);
1652: return r;
1653: }
1654: /* success */
1655: *agent_fdp = agent_fd;
1656: *idlistp = idlist;
1657: debug_f("agent returned %zu keys", idlist->nkeys);
1658: return 0;
1659: }
1.272 djm 1660:
1.117 markus 1661: /*
1662: * try keys in the following order:
1.332 djm 1663: * 1. certificates listed in the config file
1664: * 2. other input certificates
1.227 djm 1665: * 3. agent keys that are found in the config file
1666: * 4. other agent keys
1667: * 5. keys that are only listed in the config file
1.117 markus 1668: */
1669: static void
1.352 djm 1670: pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
1.51 markus 1671: {
1.214 djm 1672: struct identity *id, *id2, *tmp;
1673: struct idlist agent, files, *preferred;
1674: struct sshkey *key;
1.230 djm 1675: int agent_fd = -1, i, r, found;
1.214 djm 1676: size_t j;
1677: struct ssh_identitylist *idlist;
1.287 djm 1678: char *ident;
1.51 markus 1679:
1.117 markus 1680: TAILQ_INIT(&agent); /* keys from the agent */
1681: TAILQ_INIT(&files); /* keys from the config file */
1682: preferred = &authctxt->keys;
1683: TAILQ_INIT(preferred); /* preferred order of keys */
1684:
1.190 djm 1685: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1686: for (i = 0; i < options.num_identity_files; i++) {
1687: key = options.identity_keys[i];
1.309 djm 1688: if (key && key->cert &&
1689: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1690: debug_f("ignoring certificate %s: not a user "
1691: "certificate", options.identity_files[i]);
1.309 djm 1692: continue;
1693: }
1.311 markus 1694: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1695: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1696: "SecurityKeyProvider has been specified",
1.331 djm 1697: options.identity_files[i]);
1.117 markus 1698: continue;
1.309 djm 1699: }
1.117 markus 1700: options.identity_keys[i] = NULL;
1.150 djm 1701: id = xcalloc(1, sizeof(*id));
1.230 djm 1702: id->agent_fd = -1;
1.117 markus 1703: id->key = key;
1704: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1705: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1706: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1707: }
1.227 djm 1708: /* list of certificates specified by user */
1709: for (i = 0; i < options.num_certificate_files; i++) {
1710: key = options.certificates[i];
1.278 markus 1711: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1712: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1713: debug_f("ignoring certificate %s: not a user "
1714: "certificate", options.identity_files[i]);
1.227 djm 1715: continue;
1.309 djm 1716: }
1.311 markus 1717: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1718: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1719: "certificate %s as no "
1.309 djm 1720: "SecurityKeyProvider has been specified",
1.331 djm 1721: options.identity_files[i]);
1.309 djm 1722: continue;
1723: }
1.227 djm 1724: id = xcalloc(1, sizeof(*id));
1.230 djm 1725: id->agent_fd = -1;
1.227 djm 1726: id->key = key;
1727: id->filename = xstrdup(options.certificate_files[i]);
1728: id->userprovided = options.certificate_file_userprovided[i];
1729: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1730: }
1731: /* list of keys supported by the agent */
1.352 djm 1732: if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
1.214 djm 1733: for (j = 0; j < idlist->nkeys; j++) {
1.361 djm 1734: if ((r = sshkey_check_rsa_length(idlist->keys[j],
1735: options.required_rsa_size)) != 0) {
1736: debug_fr(r, "ignoring %s agent key",
1737: sshkey_ssh_name(idlist->keys[j]));
1738: continue;
1739: }
1.117 markus 1740: found = 0;
1741: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1742: /*
1743: * agent keys from the config file are
1744: * preferred
1745: */
1746: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1747: TAILQ_REMOVE(&files, id, next);
1748: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1749: id->agent_fd = agent_fd;
1.117 markus 1750: found = 1;
1751: break;
1752: }
1753: }
1.135 markus 1754: if (!found && !options.identities_only) {
1.150 djm 1755: id = xcalloc(1, sizeof(*id));
1.214 djm 1756: /* XXX "steals" key/comment from idlist */
1757: id->key = idlist->keys[j];
1758: id->filename = idlist->comments[j];
1759: idlist->keys[j] = NULL;
1760: idlist->comments[j] = NULL;
1761: id->agent_fd = agent_fd;
1.117 markus 1762: TAILQ_INSERT_TAIL(&agent, id, next);
1763: }
1764: }
1.214 djm 1765: ssh_free_identitylist(idlist);
1.117 markus 1766: /* append remaining agent keys */
1.324 bket 1767: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1768: authctxt->agent_fd = agent_fd;
1.244 djm 1769: }
1770: /* Prefer PKCS11 keys that are explicitly listed */
1771: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1772: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1773: continue;
1774: found = 0;
1775: TAILQ_FOREACH(id2, &files, next) {
1776: if (id2->key == NULL ||
1.321 djm 1777: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1778: continue;
1779: if (sshkey_equal(id->key, id2->key)) {
1780: TAILQ_REMOVE(&files, id, next);
1781: TAILQ_INSERT_TAIL(preferred, id, next);
1782: found = 1;
1783: break;
1784: }
1785: }
1786: /* If IdentitiesOnly set and key not found then don't use it */
1787: if (!found && options.identities_only) {
1788: TAILQ_REMOVE(&files, id, next);
1.278 markus 1789: freezero(id, sizeof(*id));
1.244 djm 1790: }
1.117 markus 1791: }
1792: /* append remaining keys from the config file */
1.324 bket 1793: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1794: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1795: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1796: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1797: debug("Skipping %s key %s - "
1.342 dtucker 1798: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1799: sshkey_ssh_name(id->key), id->filename);
1800: TAILQ_REMOVE(preferred, id, next);
1801: sshkey_free(id->key);
1802: free(id->filename);
1803: memset(id, 0, sizeof(*id));
1804: continue;
1805: }
1.117 markus 1806: }
1.287 djm 1807: /* List the keys we plan on using */
1808: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1809: ident = format_identity(id);
1810: debug("Will attempt key: %s", ident);
1811: free(ident);
1812: }
1.331 djm 1813: debug2_f("done");
1.17 markus 1814: }
1815:
1.117 markus 1816: static void
1.303 djm 1817: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1818: {
1.302 djm 1819: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1820: Identity *id;
1.51 markus 1821:
1.289 djm 1822: if (authctxt->agent_fd != -1) {
1.214 djm 1823: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1824: authctxt->agent_fd = -1;
1825: }
1.117 markus 1826: for (id = TAILQ_FIRST(&authctxt->keys); id;
1827: id = TAILQ_FIRST(&authctxt->keys)) {
1828: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1829: sshkey_free(id->key);
1.197 djm 1830: free(id->filename);
1831: free(id);
1.117 markus 1832: }
1.1 markus 1833: }
1834:
1.251 djm 1835: static void
1836: pubkey_reset(Authctxt *authctxt)
1837: {
1838: Identity *id;
1839:
1840: TAILQ_FOREACH(id, &authctxt->keys, next)
1841: id->tried = 0;
1842: }
1843:
1.225 markus 1844: static int
1.295 djm 1845: userauth_pubkey(struct ssh *ssh)
1.20 markus 1846: {
1.295 djm 1847: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1848: Identity *id;
1.20 markus 1849: int sent = 0;
1.287 djm 1850: char *ident;
1.20 markus 1851:
1.117 markus 1852: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1853: if (id->tried++)
1854: return (0);
1.127 markus 1855: /* move key to the end of the queue */
1.117 markus 1856: TAILQ_REMOVE(&authctxt->keys, id, next);
1857: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1858: /*
1859: * send a test message if we have the public key. for
1860: * encrypted keys we cannot do this and have to load the
1861: * private key instead
1862: */
1.200 djm 1863: if (id->key != NULL) {
1.367 ! dtucker 1864: ident = format_identity(id);
! 1865: debug("Offering public key: %s", ident);
! 1866: free(ident);
! 1867: sent = send_pubkey_test(ssh, id);
1.200 djm 1868: } else {
1.117 markus 1869: debug("Trying private key: %s", id->filename);
1.229 jcs 1870: id->key = load_identity_file(id);
1.117 markus 1871: if (id->key != NULL) {
1.362 dtucker 1872: if (id->key != NULL) {
1.225 markus 1873: id->isprivate = 1;
1.295 djm 1874: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1875: }
1.278 markus 1876: sshkey_free(id->key);
1.117 markus 1877: id->key = NULL;
1.251 djm 1878: id->isprivate = 0;
1.51 markus 1879: }
1880: }
1.117 markus 1881: if (sent)
1882: return (sent);
1.28 markus 1883: }
1.117 markus 1884: return (0);
1.20 markus 1885: }
1886:
1.23 markus 1887: /*
1888: * Send userauth request message specifying keyboard-interactive method.
1889: */
1.302 djm 1890: static int
1.295 djm 1891: userauth_kbdint(struct ssh *ssh)
1.23 markus 1892: {
1.295 djm 1893: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1894: int r;
1.23 markus 1895:
1.292 djm 1896: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1897: return 0;
1.82 markus 1898: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1899: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1900: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1901: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1902: return 0;
1903: }
1.23 markus 1904:
1905: debug2("userauth_kbdint");
1.278 markus 1906: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1907: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1908: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1909: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1910: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1911: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1912: options.kbd_interactive_devices : "")) != 0 ||
1913: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1914: fatal_fr(r, "send packet");
1.23 markus 1915:
1.278 markus 1916: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1917: return 1;
1918: }
1919:
1920: /*
1.46 markus 1921: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1922: */
1.302 djm 1923: static int
1.261 markus 1924: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1925: {
1.260 markus 1926: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1927: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1928: char *display_prompt = NULL, *response = NULL;
1.278 markus 1929: u_char echo = 0;
1.32 markus 1930: u_int num_prompts, i;
1.278 markus 1931: int r;
1.23 markus 1932:
1.335 djm 1933: debug2_f("entering");
1.23 markus 1934:
1935: if (authctxt == NULL)
1.335 djm 1936: fatal_f("no authentication context");
1.82 markus 1937:
1938: authctxt->info_req_seen = 1;
1.23 markus 1939:
1.278 markus 1940: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1941: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1942: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1943: goto out;
1.23 markus 1944: if (strlen(name) > 0)
1.116 itojun 1945: logit("%s", name);
1.23 markus 1946: if (strlen(inst) > 0)
1.116 itojun 1947: logit("%s", inst);
1.23 markus 1948:
1.278 markus 1949: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1950: goto out;
1.23 markus 1951: /*
1952: * Begin to build info response packet based on prompts requested.
1953: * We commit to providing the correct number of responses, so if
1954: * further on we run into a problem that prevents this, we have to
1955: * be sure and clean this up and send a correct error response.
1956: */
1.278 markus 1957: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1958: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1959: goto out;
1.23 markus 1960:
1.335 djm 1961: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1962: for (i = 0; i < num_prompts; i++) {
1.278 markus 1963: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1964: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1965: goto out;
1.336 djm 1966: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1967: authctxt->server_user, options.host_key_alias ?
1.336 djm 1968: options.host_key_alias : authctxt->host, prompt) == -1)
1969: fatal_f("asmprintf failed");
1.335 djm 1970: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1971: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1972: goto out;
1973: freezero(response, strlen(response));
1.197 djm 1974: free(prompt);
1.335 djm 1975: free(display_prompt);
1976: display_prompt = response = prompt = NULL;
1.23 markus 1977: }
1.278 markus 1978: /* done with parsing incoming message. */
1979: if ((r = sshpkt_get_end(ssh)) != 0 ||
1980: (r = sshpkt_add_padding(ssh, 64)) != 0)
1981: goto out;
1982: r = sshpkt_send(ssh);
1983: out:
1984: if (response)
1985: freezero(response, strlen(response));
1986: free(prompt);
1.335 djm 1987: free(display_prompt);
1.278 markus 1988: free(name);
1989: free(inst);
1990: free(lang);
1991: return r;
1.68 markus 1992: }
1993:
1.100 markus 1994: static int
1.294 djm 1995: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 1996: const u_char *data, size_t datalen)
1.100 markus 1997: {
1.223 djm 1998: struct sshbuf *b;
1.101 markus 1999: struct stat st;
1.100 markus 2000: pid_t pid;
1.304 deraadt 2001: int r, to[2], from[2], status;
1.295 djm 2002: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 2003: u_char rversion = 0, version = 2;
2004: void (*osigchld)(int);
1.100 markus 2005:
1.223 djm 2006: *sigp = NULL;
2007: *lenp = 0;
1.100 markus 2008:
1.306 deraadt 2009: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 2010: error_f("not installed: %s", strerror(errno));
1.223 djm 2011: return -1;
2012: }
2013: if (fflush(stdout) != 0) {
1.331 djm 2014: error_f("fflush: %s", strerror(errno));
1.101 markus 2015: return -1;
2016: }
1.306 deraadt 2017: if (pipe(to) == -1) {
1.331 djm 2018: error_f("pipe: %s", strerror(errno));
1.100 markus 2019: return -1;
2020: }
1.306 deraadt 2021: if (pipe(from) == -1) {
1.331 djm 2022: error_f("pipe: %s", strerror(errno));
1.100 markus 2023: return -1;
2024: }
1.306 deraadt 2025: if ((pid = fork()) == -1) {
1.331 djm 2026: error_f("fork: %s", strerror(errno));
1.100 markus 2027: return -1;
2028: }
1.317 dtucker 2029: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 2030: if (pid == 0) {
2031: close(from[0]);
1.306 deraadt 2032: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2033: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2034: close(to[1]);
1.306 deraadt 2035: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2036: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2037: close(from[1]);
2038: close(to[0]);
1.304 deraadt 2039:
1.306 deraadt 2040: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2041: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2042: sock = STDERR_FILENO + 1;
1.363 dtucker 2043: if (fcntl(sock, F_SETFD, 0) == -1) /* keep the socket on exec */
2044: debug3_f("fcntl F_SETFD: %s", strerror(errno));
1.223 djm 2045: closefrom(sock + 1);
1.304 deraadt 2046:
1.331 djm 2047: debug3_f("[child] pid=%ld, exec %s",
2048: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2049: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2050: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2051: strerror(errno));
2052: }
2053: close(from[1]);
2054: close(to[0]);
1.305 djm 2055: sock = STDERR_FILENO + 1;
1.100 markus 2056:
1.223 djm 2057: if ((b = sshbuf_new()) == NULL)
1.331 djm 2058: fatal_f("sshbuf_new failed");
1.223 djm 2059: /* send # of sock, data to be signed */
1.253 djm 2060: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2061: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2062: fatal_fr(r, "buffer error");
1.223 djm 2063: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2064: fatal_f("couldn't send request");
1.223 djm 2065: sshbuf_reset(b);
2066: r = ssh_msg_recv(from[0], b);
1.101 markus 2067: close(from[0]);
2068: close(to[1]);
1.223 djm 2069: if (r < 0) {
1.331 djm 2070: error_f("no reply");
1.223 djm 2071: goto fail;
2072: }
1.101 markus 2073:
1.223 djm 2074: errno = 0;
1.306 deraadt 2075: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2076: if (errno != EINTR) {
1.331 djm 2077: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2078: goto fail;
2079: }
2080: }
2081: if (!WIFEXITED(status)) {
1.331 djm 2082: error_f("exited abnormally");
1.223 djm 2083: goto fail;
2084: }
2085: if (WEXITSTATUS(status) != 0) {
1.331 djm 2086: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2087: goto fail;
2088: }
2089: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2090: error_fr(r, "buffer error");
1.223 djm 2091: goto fail;
2092: }
2093: if (rversion != version) {
1.331 djm 2094: error_f("bad version");
1.223 djm 2095: goto fail;
2096: }
2097: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2098: error_fr(r, "buffer error");
1.223 djm 2099: fail:
1.317 dtucker 2100: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2101: sshbuf_free(b);
1.100 markus 2102: return -1;
2103: }
1.317 dtucker 2104: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2105: sshbuf_free(b);
1.100 markus 2106:
2107: return 0;
2108: }
2109:
1.302 djm 2110: static int
1.295 djm 2111: userauth_hostbased(struct ssh *ssh)
1.68 markus 2112: {
1.295 djm 2113: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2114: struct sshkey *private = NULL;
2115: struct sshbuf *b = NULL;
2116: u_char *sig = NULL, *keyblob = NULL;
2117: char *fp = NULL, *chost = NULL, *lname = NULL;
2118: size_t siglen = 0, keylen = 0;
2119: int i, r, success = 0;
2120:
2121: if (authctxt->ktypes == NULL) {
1.344 dtucker 2122: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2123: authctxt->ktypes = authctxt->oktypes;
2124: }
1.213 djm 2125:
1.223 djm 2126: /*
1.344 dtucker 2127: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2128: * trying each hostkey that matches the type in turn.
2129: */
2130: for (;;) {
2131: if (authctxt->active_ktype == NULL)
2132: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2133: if (authctxt->active_ktype == NULL ||
2134: *authctxt->active_ktype == '\0')
2135: break;
1.331 djm 2136: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2137:
1.223 djm 2138: /* check for a useful key */
2139: private = NULL;
2140: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2141: if (authctxt->sensitive->keys[i] == NULL ||
2142: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2143: continue;
1.355 djm 2144: if (!sshkey_match_keyname_to_sigalgs(
1.223 djm 2145: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.355 djm 2146: authctxt->active_ktype))
1.223 djm 2147: continue;
1.68 markus 2148: /* we take and free the key */
1.223 djm 2149: private = authctxt->sensitive->keys[i];
2150: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2151: break;
2152: }
1.223 djm 2153: /* Found one */
2154: if (private != NULL)
2155: break;
2156: /* No more keys of this type; advance */
2157: authctxt->active_ktype = NULL;
1.68 markus 2158: }
1.223 djm 2159: if (private == NULL) {
2160: free(authctxt->oktypes);
2161: authctxt->oktypes = authctxt->ktypes = NULL;
2162: authctxt->active_ktype = NULL;
1.109 markus 2163: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2164: goto out;
1.68 markus 2165: }
1.211 djm 2166:
1.223 djm 2167: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2168: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2169: error_f("sshkey_fingerprint failed");
1.223 djm 2170: goto out;
1.68 markus 2171: }
1.355 djm 2172: debug_f("trying hostkey %s %s using sigalg %s",
2173: sshkey_ssh_name(private), fp, authctxt->active_ktype);
1.211 djm 2174:
1.84 markus 2175: /* figure out a name for the client host */
1.295 djm 2176: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2177: if (lname == NULL) {
1.331 djm 2178: error_f("cannot get local ipaddr/name");
1.223 djm 2179: goto out;
1.84 markus 2180: }
1.223 djm 2181:
2182: /* XXX sshbuf_put_stringf? */
2183: xasprintf(&chost, "%s.", lname);
1.331 djm 2184: debug2_f("chost %s", chost);
1.84 markus 2185:
1.68 markus 2186: /* construct data */
1.223 djm 2187: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2188: error_f("sshbuf_new failed");
1.223 djm 2189: goto out;
2190: }
2191: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2192: error_fr(r, "sshkey_to_blob");
1.223 djm 2193: goto out;
2194: }
1.346 djm 2195: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2196: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2197: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2198: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2199: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2200: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2201: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2202: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2203: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2204: error_fr(r, "buffer error");
1.223 djm 2205: goto out;
2206: }
2207:
1.68 markus 2208: #ifdef DEBUG_PK
1.223 djm 2209: sshbuf_dump(b, stderr);
1.68 markus 2210: #endif
1.294 djm 2211: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2212: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2213: error("sign using hostkey %s %s failed",
2214: sshkey_ssh_name(private), fp);
2215: goto out;
2216: }
2217: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2218: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2219: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2220: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2221: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2222: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2223: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2224: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2225: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2226: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2227: error_fr(r, "packet error");
1.223 djm 2228: goto out;
2229: }
2230: success = 1;
2231:
2232: out:
1.278 markus 2233: if (sig != NULL)
2234: freezero(sig, siglen);
1.223 djm 2235: free(keyblob);
2236: free(lname);
2237: free(fp);
1.197 djm 2238: free(chost);
1.223 djm 2239: sshkey_free(private);
2240: sshbuf_free(b);
1.68 markus 2241:
1.223 djm 2242: return success;
1.23 markus 2243: }
1.170 djm 2244:
1.20 markus 2245: /* find auth method */
2246:
2247: /*
2248: * given auth method name, if configurable options permit this method fill
2249: * in auth_ident field and return true, otherwise return false.
2250: */
1.76 itojun 2251: static int
1.20 markus 2252: authmethod_is_enabled(Authmethod *method)
2253: {
2254: if (method == NULL)
2255: return 0;
2256: /* return false if options indicate this method is disabled */
2257: if (method->enabled == NULL || *method->enabled == 0)
2258: return 0;
2259: /* return false if batch mode is enabled but method needs interactive mode */
2260: if (method->batch_flag != NULL && *method->batch_flag != 0)
2261: return 0;
2262: return 1;
2263: }
2264:
1.76 itojun 2265: static Authmethod *
1.20 markus 2266: authmethod_lookup(const char *name)
1.1 markus 2267: {
1.20 markus 2268: Authmethod *method = NULL;
2269: if (name != NULL)
2270: for (method = authmethods; method->name != NULL; method++)
2271: if (strcmp(name, method->name) == 0)
2272: return method;
2273: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2274: return NULL;
2275: }
1.1 markus 2276:
1.53 markus 2277: /* XXX internal state */
2278: static Authmethod *current = NULL;
2279: static char *supported = NULL;
2280: static char *preferred = NULL;
1.105 deraadt 2281:
1.20 markus 2282: /*
2283: * Given the authentication method list sent by the server, return the
2284: * next method we should try. If the server initially sends a nil list,
1.67 markus 2285: * use a built-in default list.
1.41 stevesk 2286: */
1.76 itojun 2287: static Authmethod *
1.20 markus 2288: authmethod_get(char *authlist)
2289: {
1.53 markus 2290: char *name = NULL;
1.97 markus 2291: u_int next;
1.41 stevesk 2292:
1.20 markus 2293: /* Use a suitable default if we're passed a nil list. */
2294: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2295: authlist = options.preferred_authentications;
1.20 markus 2296:
1.53 markus 2297: if (supported == NULL || strcmp(authlist, supported) != 0) {
2298: debug3("start over, passed a different list %s", authlist);
1.197 djm 2299: free(supported);
1.53 markus 2300: supported = xstrdup(authlist);
2301: preferred = options.preferred_authentications;
2302: debug3("preferred %s", preferred);
2303: current = NULL;
2304: } else if (current != NULL && authmethod_is_enabled(current))
2305: return current;
1.20 markus 2306:
1.53 markus 2307: for (;;) {
2308: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2309: debug("No more authentication methods to try.");
1.53 markus 2310: current = NULL;
2311: return NULL;
2312: }
2313: preferred += next;
1.23 markus 2314: debug3("authmethod_lookup %s", name);
1.53 markus 2315: debug3("remaining preferred: %s", preferred);
2316: if ((current = authmethod_lookup(name)) != NULL &&
2317: authmethod_is_enabled(current)) {
1.23 markus 2318: debug3("authmethod_is_enabled %s", name);
1.109 markus 2319: debug("Next authentication method: %s", name);
1.197 djm 2320: free(name);
1.53 markus 2321: return current;
1.23 markus 2322: }
1.198 dtucker 2323: free(name);
1.1 markus 2324: }
1.53 markus 2325: }
1.1 markus 2326:
1.79 stevesk 2327: static char *
1.53 markus 2328: authmethods_get(void)
2329: {
2330: Authmethod *method = NULL;
1.278 markus 2331: struct sshbuf *b;
1.93 markus 2332: char *list;
1.278 markus 2333: int r;
1.27 provos 2334:
1.278 markus 2335: if ((b = sshbuf_new()) == NULL)
1.331 djm 2336: fatal_f("sshbuf_new failed");
1.53 markus 2337: for (method = authmethods; method->name != NULL; method++) {
2338: if (authmethod_is_enabled(method)) {
1.278 markus 2339: if ((r = sshbuf_putf(b, "%s%s",
2340: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2341: fatal_fr(r, "buffer error");
1.53 markus 2342: }
2343: }
1.278 markus 2344: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2345: fatal_f("sshbuf_dup_string failed");
1.278 markus 2346: sshbuf_free(b);
1.93 markus 2347: return list;
1.1 markus 2348: }
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