Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.369
1.369 ! djm 1: /* $OpenBSD: sshconnect2.c,v 1.368 2023/10/12 02:15:53 djm Exp $ */
1.1 markus 2: /*
3: * Copyright (c) 2000 Markus Friedl. All rights reserved.
1.170 djm 4: * Copyright (c) 2008 Damien Miller. All rights reserved.
1.1 markus 5: *
6: * Redistribution and use in source and binary forms, with or without
7: * modification, are permitted provided that the following conditions
8: * are met:
9: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: *
15: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
1.145 stevesk 27: #include <sys/types.h>
1.160 deraadt 28: #include <sys/socket.h>
1.145 stevesk 29: #include <sys/wait.h>
1.144 stevesk 30: #include <sys/queue.h>
1.146 stevesk 31: #include <sys/stat.h>
1.156 stevesk 32:
33: #include <errno.h>
1.174 dtucker 34: #include <fcntl.h>
1.336 djm 35: #include <limits.h>
1.164 jolan 36: #include <netdb.h>
1.159 stevesk 37: #include <stdio.h>
1.158 stevesk 38: #include <string.h>
1.313 deraadt 39: #include <stdarg.h>
1.160 deraadt 40: #include <signal.h>
41: #include <pwd.h>
1.157 stevesk 42: #include <unistd.h>
1.166 djm 43: #include <vis.h>
1.1 markus 44:
1.160 deraadt 45: #include "xmalloc.h"
1.1 markus 46: #include "ssh.h"
1.37 markus 47: #include "ssh2.h"
1.278 markus 48: #include "sshbuf.h"
1.1 markus 49: #include "packet.h"
50: #include "compat.h"
1.37 markus 51: #include "cipher.h"
1.278 markus 52: #include "sshkey.h"
1.1 markus 53: #include "kex.h"
54: #include "sshconnect.h"
55: #include "authfile.h"
1.57 provos 56: #include "dh.h"
1.17 markus 57: #include "authfd.h"
1.37 markus 58: #include "log.h"
1.210 millert 59: #include "misc.h"
1.37 markus 60: #include "readconf.h"
1.53 markus 61: #include "match.h"
1.61 markus 62: #include "dispatch.h"
1.68 markus 63: #include "canohost.h"
1.100 markus 64: #include "msg.h"
65: #include "pathnames.h"
1.154 markus 66: #include "uidswap.h"
1.186 djm 67: #include "hostfile.h"
1.214 djm 68: #include "ssherr.h"
1.246 djm 69: #include "utf8.h"
1.309 djm 70: #include "ssh-sk.h"
1.312 djm 71: #include "sk-api.h"
1.22 provos 72:
1.121 markus 73: #ifdef GSSAPI
74: #include "ssh-gss.h"
75: #endif
1.293 djm 76:
1.1 markus 77: /* import */
78: extern char *client_version_string;
79: extern char *server_version_string;
80: extern Options options;
81:
82: /*
83: * SSH2 key exchange
84: */
85:
1.338 djm 86: static char *xxx_host;
87: static struct sockaddr *xxx_hostaddr;
88: static const struct ssh_conn_info *xxx_conn_info;
1.61 markus 89:
1.76 itojun 90: static int
1.259 markus 91: verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
1.61 markus 92: {
1.361 djm 93: int r;
94:
95: if ((r = sshkey_check_rsa_length(hostkey,
96: options.required_rsa_size)) != 0)
97: fatal_r(r, "Bad server host key");
1.338 djm 98: if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
99: xxx_conn_info) == -1)
1.83 markus 100: fatal("Host key verification failed.");
1.61 markus 101: return 0;
102: }
103:
1.326 djm 104: /* Returns the first item from a comma-separated algorithm list */
105: static char *
106: first_alg(const char *algs)
107: {
108: char *ret, *cp;
109:
110: ret = xstrdup(algs);
111: if ((cp = strchr(ret, ',')) != NULL)
112: *cp = '\0';
113: return ret;
114: }
115:
1.186 djm 116: static char *
1.338 djm 117: order_hostkeyalgs(char *host, struct sockaddr *hostaddr, u_short port,
118: const struct ssh_conn_info *cinfo)
1.186 djm 119: {
1.326 djm 120: char *oavail = NULL, *avail = NULL, *first = NULL, *last = NULL;
121: char *alg = NULL, *hostname = NULL, *ret = NULL, *best = NULL;
1.186 djm 122: size_t maxlen;
1.326 djm 123: struct hostkeys *hostkeys = NULL;
1.186 djm 124: int ktype;
1.188 djm 125: u_int i;
1.186 djm 126:
127: /* Find all hostkeys for this hostname */
128: get_hostfile_hostname_ipaddr(host, hostaddr, port, &hostname, NULL);
129: hostkeys = init_hostkeys();
1.188 djm 130: for (i = 0; i < options.num_user_hostfiles; i++)
1.337 djm 131: load_hostkeys(hostkeys, hostname, options.user_hostfiles[i], 0);
132: for (i = 0; i < options.num_system_hostfiles; i++) {
133: load_hostkeys(hostkeys, hostname,
134: options.system_hostfiles[i], 0);
135: }
1.339 djm 136: if (options.known_hosts_command != NULL) {
137: load_hostkeys_command(hostkeys, options.known_hosts_command,
1.369 ! djm 138: "ORDER", cinfo, NULL, hostname);
1.339 djm 139: }
1.326 djm 140: /*
141: * If a plain public key exists that matches the type of the best
142: * preference HostkeyAlgorithms, then use the whole list as is.
143: * Note that we ignore whether the best preference algorithm is a
144: * certificate type, as sshconnect.c will downgrade certs to
145: * plain keys if necessary.
146: */
147: best = first_alg(options.hostkeyalgorithms);
148: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.328 djm 149: sshkey_type_plain(sshkey_type_from_name(best)),
150: sshkey_ecdsa_nid_from_name(best), NULL)) {
1.331 djm 151: debug3_f("have matching best-preference key type %s, "
152: "using HostkeyAlgorithms verbatim", best);
1.326 djm 153: ret = xstrdup(options.hostkeyalgorithms);
154: goto out;
155: }
156:
157: /*
158: * Otherwise, prefer the host key algorithms that match known keys
159: * while keeping the ordering of HostkeyAlgorithms as much as possible.
160: */
1.320 djm 161: oavail = avail = xstrdup(options.hostkeyalgorithms);
1.186 djm 162: maxlen = strlen(avail) + 1;
163: first = xmalloc(maxlen);
164: last = xmalloc(maxlen);
165: *first = *last = '\0';
166:
167: #define ALG_APPEND(to, from) \
168: do { \
169: if (*to != '\0') \
170: strlcat(to, ",", maxlen); \
171: strlcat(to, from, maxlen); \
172: } while (0)
173:
174: while ((alg = strsep(&avail, ",")) && *alg != '\0') {
1.214 djm 175: if ((ktype = sshkey_type_from_name(alg)) == KEY_UNSPEC)
1.331 djm 176: fatal_f("unknown alg %s", alg);
1.322 djm 177: /*
178: * If we have a @cert-authority marker in known_hosts then
179: * prefer all certificate algorithms.
180: */
181: if (sshkey_type_is_cert(ktype) &&
182: lookup_marker_in_hostkeys(hostkeys, MRK_CA)) {
183: ALG_APPEND(first, alg);
184: continue;
185: }
186: /* If the key appears in known_hosts then prefer it */
1.186 djm 187: if (lookup_key_in_hostkeys_by_type(hostkeys,
1.328 djm 188: sshkey_type_plain(ktype),
189: sshkey_ecdsa_nid_from_name(alg), NULL)) {
1.186 djm 190: ALG_APPEND(first, alg);
1.322 djm 191: continue;
192: }
193: /* Otherwise, put it last */
194: ALG_APPEND(last, alg);
1.186 djm 195: }
196: #undef ALG_APPEND
1.216 djm 197: xasprintf(&ret, "%s%s%s", first,
198: (*first == '\0' || *last == '\0') ? "" : ",", last);
1.186 djm 199: if (*first != '\0')
1.331 djm 200: debug3_f("prefer hostkeyalgs: %s", first);
1.339 djm 201: else
202: debug3_f("no algorithms matched; accept original");
1.326 djm 203: out:
204: free(best);
1.197 djm 205: free(first);
206: free(last);
207: free(hostname);
208: free(oavail);
1.186 djm 209: free_hostkeys(hostkeys);
210:
211: return ret;
212: }
213:
1.1 markus 214: void
1.338 djm 215: ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port,
216: const struct ssh_conn_info *cinfo)
1.22 provos 217: {
1.364 dtucker 218: char *myproposal[PROPOSAL_MAX];
219: char *s, *all_key, *hkalgs = NULL;
1.366 dtucker 220: int r, use_known_hosts_order = 0;
1.61 markus 221:
222: xxx_host = host;
223: xxx_hostaddr = hostaddr;
1.338 djm 224: xxx_conn_info = cinfo;
1.22 provos 225:
1.364 dtucker 226: if (options.rekey_limit || options.rekey_interval)
227: ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
228: options.rekey_interval);
1.320 djm 229:
1.366 dtucker 230: /*
231: * If the user has not specified HostkeyAlgorithms, or has only
232: * appended or removed algorithms from that list then prefer algorithms
233: * that are in the list that are supported by known_hosts keys.
234: */
235: if (options.hostkeyalgorithms == NULL ||
236: options.hostkeyalgorithms[0] == '-' ||
237: options.hostkeyalgorithms[0] == '+')
238: use_known_hosts_order = 1;
239:
1.320 djm 240: /* Expand or fill in HostkeyAlgorithms */
241: all_key = sshkey_alg_list(0, 0, 1, ',');
1.333 djm 242: if ((r = kex_assemble_names(&options.hostkeyalgorithms,
243: kex_default_pk_alg(), all_key)) != 0)
244: fatal_fr(r, "kex_assemble_namelist");
1.320 djm 245: free(all_key);
246:
1.231 markus 247: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
1.331 djm 248: fatal_f("kex_names_cat");
1.115 markus 249:
1.366 dtucker 250: if (use_known_hosts_order)
1.364 dtucker 251: hkalgs = order_hostkeyalgs(host, hostaddr, port, cinfo);
252:
253: kex_proposal_populate_entries(ssh, myproposal, s, options.ciphers,
254: options.macs, compression_alg_list(options.compression),
255: hkalgs ? hkalgs : options.hostkeyalgorithms);
256:
257: free(hkalgs);
1.22 provos 258:
1.65 markus 259: /* start key exchange */
1.291 djm 260: if ((r = kex_setup(ssh, myproposal)) != 0)
1.331 djm 261: fatal_r(r, "kex_setup");
1.207 markus 262: #ifdef WITH_OPENSSL
1.301 djm 263: ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
264: ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
265: ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
266: ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
267: ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
1.291 djm 268: ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
269: ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.301 djm 270: ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
1.207 markus 271: #endif
1.301 djm 272: ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
1.340 djm 273: ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
1.291 djm 274: ssh->kex->verify_host_key=&verify_host_key_callback;
1.22 provos 275:
1.291 djm 276: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
1.173 andreas 277:
1.231 markus 278: /* remove ext-info from the KEX proposals for rekeying */
1.364 dtucker 279: free(myproposal[PROPOSAL_KEX_ALGS]);
1.231 markus 280: myproposal[PROPOSAL_KEX_ALGS] =
1.345 djm 281: compat_kex_proposal(ssh, options.kex_algorithms);
1.291 djm 282: if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
1.331 djm 283: fatal_r(r, "kex_prop2buf");
1.62 markus 284:
1.22 provos 285: #ifdef DEBUG_KEXDH
286: /* send 1st encrypted/maced/compressed message */
1.278 markus 287: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
288: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
1.280 markus 289: (r = sshpkt_send(ssh)) != 0 ||
290: (r = ssh_packet_write_wait(ssh)) != 0)
1.331 djm 291: fatal_fr(r, "send packet");
1.22 provos 292: #endif
1.364 dtucker 293: kex_proposal_free_entries(myproposal);
1.1 markus 294: }
1.11 markus 295:
1.1 markus 296: /*
297: * Authenticate user
298: */
1.20 markus 299:
1.214 djm 300: typedef struct cauthctxt Authctxt;
301: typedef struct cauthmethod Authmethod;
1.117 markus 302: typedef struct identity Identity;
303: typedef struct idlist Idlist;
1.20 markus 304:
1.117 markus 305: struct identity {
306: TAILQ_ENTRY(identity) next;
1.214 djm 307: int agent_fd; /* >=0 if agent supports key */
308: struct sshkey *key; /* public/private key */
1.117 markus 309: char *filename; /* comment for agent-only keys */
310: int tried;
311: int isprivate; /* key points to the private key */
1.191 dtucker 312: int userprovided;
1.117 markus 313: };
314: TAILQ_HEAD(idlist, identity);
1.20 markus 315:
1.214 djm 316: struct cauthctxt {
1.20 markus 317: const char *server_user;
1.68 markus 318: const char *local_user;
1.20 markus 319: const char *host;
320: const char *service;
1.214 djm 321: struct cauthmethod *method;
1.183 djm 322: sig_atomic_t success;
1.51 markus 323: char *authlist;
1.302 djm 324: #ifdef GSSAPI
325: /* gssapi */
326: gss_OID_set gss_supported_mechs;
327: u_int mech_tried;
328: #endif
1.68 markus 329: /* pubkey */
1.214 djm 330: struct idlist keys;
331: int agent_fd;
1.68 markus 332: /* hostbased */
1.100 markus 333: Sensitive *sensitive;
1.223 djm 334: char *oktypes, *ktypes;
335: const char *active_ktype;
1.82 markus 336: /* kbd-interactive */
337: int info_req_seen;
1.292 djm 338: int attempt_kbdint;
339: /* password */
340: int attempt_passwd;
1.121 markus 341: /* generic */
342: void *methoddata;
1.20 markus 343: };
1.214 djm 344:
345: struct cauthmethod {
1.20 markus 346: char *name; /* string to compare against server's list */
1.295 djm 347: int (*userauth)(struct ssh *ssh);
348: void (*cleanup)(struct ssh *ssh);
1.20 markus 349: int *enabled; /* flag in option struct that enables method */
350: int *batch_flag; /* flag in option struct that disables method */
351: };
352:
1.302 djm 353: static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
354: static int input_userauth_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);
1.368 djm 472: #ifdef GSSAPI
473: if (authctxt.gss_supported_mechs != NULL) {
474: u_int ms;
475:
476: gss_release_oid_set(&ms, &authctxt.gss_supported_mechs);
477: authctxt.gss_supported_mechs = NULL;
478: }
479: #endif
1.260 markus 480: ssh->authctxt = NULL;
1.20 markus 481:
1.231 markus 482: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 483:
1.248 dtucker 484: if (!authctxt.success)
485: fatal("Authentication failed.");
1.351 djm 486: if (ssh_packet_connection_is_on_socket(ssh)) {
487: verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
488: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
489: authctxt.method->name);
490: } else {
491: verbose("Authenticated to %s (via proxy) using \"%s\".", host,
492: authctxt.method->name);
493: }
1.20 markus 494: }
1.119 markus 495:
1.302 djm 496: static int
1.261 markus 497: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 498: {
499: int r;
500:
501: if (ssh_packet_remaining(ssh) > 0) {
502: char *reply;
503:
504: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
505: goto out;
506: debug2("service_accept: %s", reply);
507: free(reply);
508: } else {
509: debug2("buggy server: service_accept w/o service");
510: }
511: if ((r = sshpkt_get_end(ssh)) != 0)
512: goto out;
513: debug("SSH2_MSG_SERVICE_ACCEPT received");
514:
515: /* initial userauth request */
1.295 djm 516: userauth_none(ssh);
1.231 markus 517:
518: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
519: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
520: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
521: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
522: r = 0;
523: out:
524: return r;
525: }
526:
1.302 djm 527: static int
1.261 markus 528: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 529: {
1.261 markus 530: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 531: }
532:
1.20 markus 533: void
1.295 djm 534: userauth(struct ssh *ssh, char *authlist)
1.51 markus 535: {
1.295 djm 536: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 537:
1.170 djm 538: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 539: authctxt->method->cleanup(ssh);
1.170 djm 540:
1.197 djm 541: free(authctxt->methoddata);
542: authctxt->methoddata = NULL;
1.51 markus 543: if (authlist == NULL) {
544: authlist = authctxt->authlist;
545: } else {
1.197 djm 546: free(authctxt->authlist);
1.51 markus 547: authctxt->authlist = authlist;
548: }
549: for (;;) {
550: Authmethod *method = authmethod_get(authlist);
551: if (method == NULL)
1.264 dtucker 552: fatal("%s@%s: Permission denied (%s).",
553: authctxt->server_user, authctxt->host, authlist);
1.51 markus 554: authctxt->method = method;
1.119 markus 555:
556: /* reset the per method handler */
1.278 markus 557: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 558: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
559:
560: /* and try new method */
1.295 djm 561: if (method->userauth(ssh) != 0) {
1.51 markus 562: debug2("we sent a %s packet, wait for reply", method->name);
563: break;
564: } else {
565: debug2("we did not send a packet, disable method");
566: method->enabled = NULL;
567: }
568: }
569: }
1.105 deraadt 570:
1.302 djm 571: static int
1.261 markus 572: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 573: {
1.331 djm 574: fatal_f("bad message during authentication: type %d", type);
1.218 markus 575: return 0;
1.35 markus 576: }
1.105 deraadt 577:
1.302 djm 578: static int
1.261 markus 579: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 580: {
1.295 djm 581: char *msg = NULL;
1.294 djm 582: size_t len;
583: int r;
1.126 deraadt 584:
1.331 djm 585: debug3_f("entering");
1.294 djm 586: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 587: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 588: goto out;
1.246 djm 589: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
590: fmprintf(stderr, "%s", msg);
1.294 djm 591: r = 0;
592: out:
1.246 djm 593: free(msg);
1.294 djm 594: return r;
1.20 markus 595: }
1.105 deraadt 596:
1.302 djm 597: static int
1.261 markus 598: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 599: {
1.260 markus 600: Authctxt *authctxt = ssh->authctxt;
1.172 djm 601:
1.20 markus 602: if (authctxt == NULL)
1.331 djm 603: fatal_f("no authentication context");
1.197 djm 604: free(authctxt->authlist);
605: authctxt->authlist = NULL;
1.172 djm 606: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 607: authctxt->method->cleanup(ssh);
1.197 djm 608: free(authctxt->methoddata);
609: authctxt->methoddata = NULL;
1.20 markus 610: authctxt->success = 1; /* break out */
1.218 markus 611: return 0;
1.20 markus 612: }
1.105 deraadt 613:
1.302 djm 614: #if 0
615: static int
1.261 markus 616: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 617: {
1.260 markus 618: Authctxt *authctxt = ssh->authctxt;
1.172 djm 619:
620: if (authctxt == NULL)
1.331 djm 621: fatal_f("no authentication context");
1.172 djm 622:
623: fatal("Unexpected authentication success during %s.",
624: authctxt->method->name);
1.218 markus 625: return 0;
1.172 djm 626: }
1.302 djm 627: #endif
1.172 djm 628:
1.302 djm 629: static int
1.261 markus 630: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 631: {
1.260 markus 632: Authctxt *authctxt = ssh->authctxt;
1.20 markus 633: char *authlist = NULL;
1.278 markus 634: u_char partial;
1.20 markus 635:
636: if (authctxt == NULL)
637: fatal("input_userauth_failure: no authentication context");
638:
1.307 dtucker 639: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
640: sshpkt_get_u8(ssh, &partial) != 0 ||
641: sshpkt_get_end(ssh) != 0)
1.278 markus 642: goto out;
1.20 markus 643:
1.193 markus 644: if (partial != 0) {
1.351 djm 645: verbose("Authenticated using \"%s\" with partial success.",
646: authctxt->method->name);
1.193 markus 647: /* reset state */
1.251 djm 648: pubkey_reset(authctxt);
1.193 markus 649: }
1.109 markus 650: debug("Authentications that can continue: %s", authlist);
1.20 markus 651:
1.295 djm 652: userauth(ssh, authlist);
1.278 markus 653: authlist = NULL;
654: out:
655: free(authlist);
1.218 markus 656: return 0;
1.51 markus 657: }
1.169 djm 658:
1.287 djm 659: /*
660: * Format an identity for logging including filename, key type, fingerprint
661: * and location (agent, etc.). Caller must free.
662: */
663: static char *
664: format_identity(Identity *id)
665: {
666: char *fp = NULL, *ret = NULL;
1.309 djm 667: const char *note = "";
1.287 djm 668:
669: if (id->key != NULL) {
1.347 djm 670: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1.287 djm 671: SSH_FP_DEFAULT);
672: }
1.309 djm 673: if (id->key) {
674: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
675: note = " token";
1.311 markus 676: else if (sshkey_is_sk(id->key))
1.319 naddy 677: note = " authenticator";
1.309 djm 678: }
1.287 djm 679: xasprintf(&ret, "%s %s%s%s%s%s%s",
680: id->filename,
681: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
682: fp ? fp : "",
1.309 djm 683: id->userprovided ? " explicit" : "", note,
1.287 djm 684: id->agent_fd != -1 ? " agent" : "");
685: free(fp);
686: return ret;
687: }
688:
1.302 djm 689: static int
1.261 markus 690: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 691: {
1.260 markus 692: Authctxt *authctxt = ssh->authctxt;
1.259 markus 693: struct sshkey *key = NULL;
1.117 markus 694: Identity *id = NULL;
1.287 djm 695: int pktype, found = 0, sent = 0;
1.278 markus 696: size_t blen;
1.287 djm 697: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 698: u_char *pkblob = NULL;
699: int r;
1.51 markus 700:
701: if (authctxt == NULL)
702: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 703:
1.278 markus 704: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
705: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
706: (r = sshpkt_get_end(ssh)) != 0)
707: goto done;
1.51 markus 708:
1.278 markus 709: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 710: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 711: goto done;
712: }
1.278 markus 713: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 714: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 715: goto done;
716: }
717: if (key->type != pktype) {
718: error("input_userauth_pk_ok: type mismatch "
719: "for decoded key (received %d, expected %d)",
720: key->type, pktype);
721: goto done;
722: }
723:
1.127 markus 724: /*
725: * search keys in the reverse order, because last candidate has been
726: * moved to the end of the queue. this also avoids confusion by
727: * duplicate keys
728: */
1.136 henning 729: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 730: if (sshkey_equal(key, id->key)) {
1.287 djm 731: found = 1;
1.51 markus 732: break;
733: }
1.117 markus 734: }
1.287 djm 735: if (!found || id == NULL) {
736: fp = sshkey_fingerprint(key, options.fingerprint_hash,
737: SSH_FP_DEFAULT);
1.331 djm 738: error_f("server replied with unknown key: %s %s",
1.287 djm 739: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
740: goto done;
741: }
742: ident = format_identity(id);
743: debug("Server accepts key: %s", ident);
1.295 djm 744: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 745: r = 0;
746: done:
747: sshkey_free(key);
1.287 djm 748: free(ident);
749: free(fp);
1.197 djm 750: free(pkalg);
751: free(pkblob);
1.51 markus 752:
1.106 deraadt 753: /* try another method if we did not send a packet */
1.278 markus 754: if (r == 0 && sent == 0)
1.295 djm 755: userauth(ssh, NULL);
1.278 markus 756: return r;
1.20 markus 757: }
1.121 markus 758:
759: #ifdef GSSAPI
1.302 djm 760: static int
1.295 djm 761: userauth_gssapi(struct ssh *ssh)
1.121 markus 762: {
1.295 djm 763: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 764: Gssctxt *gssctxt = NULL;
765: OM_uint32 min;
1.278 markus 766: int r, ok = 0;
1.302 djm 767: gss_OID mech = NULL;
1.121 markus 768:
769: /* Try one GSSAPI method at a time, rather than sending them all at
770: * once. */
771:
1.302 djm 772: if (authctxt->gss_supported_mechs == NULL)
773: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 774:
1.302 djm 775: /* Check to see whether the mechanism is usable before we offer it */
776: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
777: !ok) {
778: mech = &authctxt->gss_supported_mechs->
779: elements[authctxt->mech_tried];
1.121 markus 780: /* My DER encoding requires length<128 */
1.302 djm 781: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
782: mech, authctxt->host)) {
1.121 markus 783: ok = 1; /* Mechanism works */
784: } else {
1.302 djm 785: authctxt->mech_tried++;
1.121 markus 786: }
787: }
788:
1.302 djm 789: if (!ok || mech == NULL)
1.139 djm 790: return 0;
1.121 markus 791:
792: authctxt->methoddata=(void *)gssctxt;
793:
1.278 markus 794: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
795: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
796: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
797: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
798: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 799: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 800: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 801: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
802: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 803: (r = sshpkt_send(ssh)) != 0)
1.331 djm 804: fatal_fr(r, "send packet");
1.278 markus 805:
806: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
807: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
808: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
809: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 810:
1.302 djm 811: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 812:
813: return 1;
814: }
815:
1.302 djm 816: static void
817: userauth_gssapi_cleanup(struct ssh *ssh)
818: {
819: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
820: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
821:
822: ssh_gssapi_delete_ctx(&gssctxt);
823: authctxt->methoddata = NULL;
824: }
825:
1.130 markus 826: static OM_uint32
1.262 djm 827: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 828: {
1.260 markus 829: Authctxt *authctxt = ssh->authctxt;
1.130 markus 830: Gssctxt *gssctxt = authctxt->methoddata;
831: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 832: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
833: gss_buffer_desc gssbuf;
1.132 markus 834: OM_uint32 status, ms, flags;
1.278 markus 835: int r;
1.133 djm 836:
1.130 markus 837: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 838: recv_tok, &send_tok, &flags);
1.130 markus 839:
840: if (send_tok.length > 0) {
1.278 markus 841: u_char type = GSS_ERROR(status) ?
842: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
843: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
844:
845: if ((r = sshpkt_start(ssh, type)) != 0 ||
846: (r = sshpkt_put_string(ssh, send_tok.value,
847: send_tok.length)) != 0 ||
848: (r = sshpkt_send(ssh)) != 0)
1.331 djm 849: fatal_fr(r, "send %u packet", type);
1.133 djm 850:
1.130 markus 851: gss_release_buffer(&ms, &send_tok);
852: }
1.133 djm 853:
1.130 markus 854: if (status == GSS_S_COMPLETE) {
1.132 markus 855: /* send either complete or MIC, depending on mechanism */
856: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 857: if ((r = sshpkt_start(ssh,
858: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
859: (r = sshpkt_send(ssh)) != 0)
1.331 djm 860: fatal_fr(r, "send completion");
1.132 markus 861: } else {
1.278 markus 862: struct sshbuf *b;
863:
864: if ((b = sshbuf_new()) == NULL)
1.331 djm 865: fatal_f("sshbuf_new failed");
1.278 markus 866: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 djm 867: authctxt->service, "gssapi-with-mic",
868: ssh->kex->session_id);
1.132 markus 869:
1.278 markus 870: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 871: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 872: gssbuf.length = sshbuf_len(b);
1.133 djm 873:
1.132 markus 874: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 875:
1.132 markus 876: if (!GSS_ERROR(status)) {
1.278 markus 877: if ((r = sshpkt_start(ssh,
878: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
879: (r = sshpkt_put_string(ssh, mic.value,
880: mic.length)) != 0 ||
881: (r = sshpkt_send(ssh)) != 0)
1.331 djm 882: fatal_fr(r, "send MIC");
1.132 markus 883: }
1.133 djm 884:
1.278 markus 885: sshbuf_free(b);
1.132 markus 886: gss_release_buffer(&ms, &mic);
1.133 djm 887: }
1.130 markus 888: }
1.133 djm 889:
1.130 markus 890: return status;
891: }
892:
1.302 djm 893: static int
1.261 markus 894: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 895: {
1.260 markus 896: Authctxt *authctxt = ssh->authctxt;
1.121 markus 897: Gssctxt *gssctxt;
1.278 markus 898: size_t oidlen;
899: u_char *oidv = NULL;
900: int r;
1.121 markus 901:
902: if (authctxt == NULL)
903: fatal("input_gssapi_response: no authentication context");
904: gssctxt = authctxt->methoddata;
905:
906: /* Setup our OID */
1.278 markus 907: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
908: goto done;
1.121 markus 909:
1.129 markus 910: if (oidlen <= 2 ||
911: oidv[0] != SSH_GSS_OIDTYPE ||
912: oidv[1] != oidlen - 2) {
913: debug("Badly encoded mechanism OID received");
1.296 djm 914: userauth(ssh, NULL);
1.278 markus 915: goto ok;
1.121 markus 916: }
1.129 markus 917:
918: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
919: fatal("Server returned different OID than expected");
1.121 markus 920:
1.278 markus 921: if ((r = sshpkt_get_end(ssh)) != 0)
922: goto done;
1.121 markus 923:
1.262 djm 924: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 925: /* Start again with next method on list */
926: debug("Trying to start again");
1.296 djm 927: userauth(ssh, NULL);
1.278 markus 928: goto ok;
1.121 markus 929: }
1.278 markus 930: ok:
931: r = 0;
932: done:
933: free(oidv);
934: return r;
1.121 markus 935: }
936:
1.302 djm 937: static int
1.261 markus 938: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 939: {
1.260 markus 940: Authctxt *authctxt = ssh->authctxt;
1.121 markus 941: gss_buffer_desc recv_tok;
1.278 markus 942: u_char *p = NULL;
943: size_t len;
1.130 markus 944: OM_uint32 status;
1.278 markus 945: int r;
1.121 markus 946:
947: if (authctxt == NULL)
948: fatal("input_gssapi_response: no authentication context");
949:
1.278 markus 950: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
951: (r = sshpkt_get_end(ssh)) != 0)
952: goto out;
1.121 markus 953:
1.278 markus 954: recv_tok.value = p;
955: recv_tok.length = len;
1.262 djm 956: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 957:
1.278 markus 958: /* Start again with the next method in the list */
1.121 markus 959: if (GSS_ERROR(status)) {
1.296 djm 960: userauth(ssh, NULL);
1.278 markus 961: /* ok */
1.121 markus 962: }
1.278 markus 963: r = 0;
964: out:
965: free(p);
966: return r;
1.121 markus 967: }
968:
1.302 djm 969: static int
1.261 markus 970: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 971: {
1.260 markus 972: Authctxt *authctxt = ssh->authctxt;
1.121 markus 973: Gssctxt *gssctxt;
974: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
975: gss_buffer_desc recv_tok;
1.194 djm 976: OM_uint32 ms;
1.278 markus 977: u_char *p = NULL;
978: size_t len;
979: int r;
1.121 markus 980:
981: if (authctxt == NULL)
982: fatal("input_gssapi_response: no authentication context");
983: gssctxt = authctxt->methoddata;
984:
1.278 markus 985: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
986: (r = sshpkt_get_end(ssh)) != 0) {
987: free(p);
988: return r;
989: }
1.121 markus 990:
991: /* Stick it into GSSAPI and see what it says */
1.278 markus 992: recv_tok.value = p;
993: recv_tok.length = len;
1.194 djm 994: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 995: &recv_tok, &send_tok, NULL);
1.278 markus 996: free(p);
1.121 markus 997: gss_release_buffer(&ms, &send_tok);
998:
999: /* Server will be returning a failed packet after this one */
1.220 djm 1000: return 0;
1.121 markus 1001: }
1002:
1.302 djm 1003: static int
1.261 markus 1004: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 1005: {
1.278 markus 1006: char *msg = NULL;
1007: char *lang = NULL;
1008: int r;
1.121 markus 1009:
1.278 markus 1010: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1011: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1012: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1013: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1014: goto out;
1015: r = sshpkt_get_end(ssh);
1.143 stevesk 1016: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1017: out:
1.197 djm 1018: free(msg);
1019: free(lang);
1.278 markus 1020: return r;
1.121 markus 1021: }
1022: #endif /* GSSAPI */
1.20 markus 1023:
1.302 djm 1024: static int
1.295 djm 1025: userauth_none(struct ssh *ssh)
1.23 markus 1026: {
1.295 djm 1027: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1028: int r;
1029:
1.23 markus 1030: /* initial userauth request */
1.278 markus 1031: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1032: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1033: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1034: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1035: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1036: fatal_fr(r, "send packet");
1.23 markus 1037: return 1;
1038: }
1039:
1.302 djm 1040: static int
1.295 djm 1041: userauth_passwd(struct ssh *ssh)
1.1 markus 1042: {
1.295 djm 1043: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1044: char *password, *prompt = NULL;
1.175 dtucker 1045: const char *host = options.host_key_alias ? options.host_key_alias :
1046: authctxt->host;
1.278 markus 1047: int r;
1.6 markus 1048:
1.292 djm 1049: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1050: return 0;
1.13 todd 1051:
1.292 djm 1052: if (authctxt->attempt_passwd != 1)
1.13 todd 1053: error("Permission denied, please try again.");
1.1 markus 1054:
1.290 djm 1055: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1056: password = read_passphrase(prompt, 0);
1.278 markus 1057: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1058: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1059: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1060: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1061: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1062: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1063: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1064: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1065: fatal_fr(r, "send packet");
1.99 markus 1066:
1.290 djm 1067: free(prompt);
1068: if (password != NULL)
1.278 markus 1069: freezero(password, strlen(password));
1070:
1071: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1072: &input_userauth_passwd_changereq);
1073:
1.1 markus 1074: return 1;
1075: }
1.169 djm 1076:
1.99 markus 1077: /*
1078: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1079: */
1.302 djm 1080: static int
1.261 markus 1081: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1082: {
1.260 markus 1083: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1084: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1085: char prompt[256];
1.252 djm 1086: const char *host;
1.278 markus 1087: int r;
1.99 markus 1088:
1089: debug2("input_userauth_passwd_changereq");
1090:
1091: if (authctxt == NULL)
1092: fatal("input_userauth_passwd_changereq: "
1093: "no authentication context");
1.252 djm 1094: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1095:
1.278 markus 1096: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1097: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1098: goto out;
1.99 markus 1099: if (strlen(info) > 0)
1.116 itojun 1100: logit("%s", info);
1.278 markus 1101: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1102: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1103: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1104: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1105: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1106: goto out;
1107:
1.104 deraadt 1108: snprintf(prompt, sizeof(prompt),
1.99 markus 1109: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1110: authctxt->server_user, host);
1.99 markus 1111: password = read_passphrase(prompt, 0);
1.278 markus 1112: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1113: goto out;
1114:
1115: freezero(password, strlen(password));
1.99 markus 1116: password = NULL;
1117: while (password == NULL) {
1.104 deraadt 1118: snprintf(prompt, sizeof(prompt),
1.99 markus 1119: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1120: authctxt->server_user, host);
1.99 markus 1121: password = read_passphrase(prompt, RP_ALLOW_EOF);
1122: if (password == NULL) {
1123: /* bail out */
1.278 markus 1124: r = 0;
1125: goto out;
1.99 markus 1126: }
1.104 deraadt 1127: snprintf(prompt, sizeof(prompt),
1.99 markus 1128: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1129: authctxt->server_user, host);
1.99 markus 1130: retype = read_passphrase(prompt, 0);
1131: if (strcmp(password, retype) != 0) {
1.278 markus 1132: freezero(password, strlen(password));
1.116 itojun 1133: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1134: password = NULL;
1135: }
1.278 markus 1136: freezero(retype, strlen(retype));
1.99 markus 1137: }
1.278 markus 1138: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1139: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1140: (r = sshpkt_send(ssh)) != 0)
1141: goto out;
1.104 deraadt 1142:
1.278 markus 1143: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1144: &input_userauth_passwd_changereq);
1.278 markus 1145: r = 0;
1146: out:
1147: if (password)
1148: freezero(password, strlen(password));
1149: free(info);
1150: free(lang);
1151: return r;
1.117 markus 1152: }
1153:
1.272 djm 1154: /*
1155: * Select an algorithm for publickey signatures.
1156: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1157: *
1158: * Call with ssh==NULL to ignore server-sig-algs extension list and
1159: * only attempt with the key's base signature type.
1160: */
1161: static char *
1162: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1163: {
1.274 djm 1164: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.348 djm 1165: const char *server_sig_algs;
1.231 markus 1166:
1.272 djm 1167: /*
1168: * The signature algorithm will only differ from the key algorithm
1169: * for RSA keys/certs and when the server advertises support for
1170: * newer (SHA2) algorithms.
1171: */
1172: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1173: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1174: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1175: /* Filter base key signature alg against our configuration */
1.279 markus 1176: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1177: options.pubkey_accepted_algos, NULL);
1.231 markus 1178: }
1179:
1.272 djm 1180: /*
1.348 djm 1181: * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1182: * fails to advertise it via SSH2_MSG_EXT_INFO.
1183: */
1184: server_sig_algs = ssh->kex->server_sig_algs;
1185: if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1186: server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1187:
1188: /*
1.272 djm 1189: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1190: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1191: * that also appears in the supported signature algorithms list from
1192: * the server.
1193: */
1.342 dtucker 1194: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1195: while ((cp = strsep(&allowed, ",")) != NULL) {
1196: if (sshkey_type_from_name(cp) != key->type)
1197: continue;
1.323 djm 1198: tmp = match_list(sshkey_sigalg_by_name(cp),
1.348 djm 1199: server_sig_algs, NULL);
1.274 djm 1200: if (tmp != NULL)
1201: alg = xstrdup(cp);
1202: free(tmp);
1.272 djm 1203: if (alg != NULL)
1204: break;
1.269 djm 1205: }
1.272 djm 1206: free(oallowed);
1207: return alg;
1.269 djm 1208: }
1209:
1.117 markus 1210: static int
1.214 djm 1211: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1212: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1213: {
1.309 djm 1214: struct sshkey *sign_key = NULL, *prv = NULL;
1.360 djm 1215: int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1216: struct notifier_ctx *notifier = NULL;
1.325 djm 1217: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1218:
1219: *sigp = NULL;
1220: *lenp = 0;
1.99 markus 1221:
1.272 djm 1222: /* The agent supports this key. */
1.269 djm 1223: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1224: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1225: data, datalen, alg, compat);
1.269 djm 1226: }
1.214 djm 1227:
1.117 markus 1228: /*
1.272 djm 1229: * We have already loaded the private key or the private key is
1230: * stored in external hardware.
1.117 markus 1231: */
1.255 djm 1232: if (id->key != NULL &&
1.272 djm 1233: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1234: sign_key = id->key;
1.360 djm 1235: is_agent = 1;
1.309 djm 1236: } else {
1237: /* Load the private key from the file. */
1238: if ((prv = load_identity_file(id)) == NULL)
1239: return SSH_ERR_KEY_NOT_FOUND;
1240: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1241: error_f("private key %s contents do not match public",
1.347 djm 1242: id->filename);
1.309 djm 1243: r = SSH_ERR_KEY_NOT_FOUND;
1244: goto out;
1245: }
1246: sign_key = prv;
1.360 djm 1247: }
1.341 djm 1248: retry_pin:
1.360 djm 1249: /* Prompt for touch for non-agent FIDO keys that request UP */
1250: if (!is_agent && sshkey_is_sk(sign_key) &&
1251: (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1252: /* XXX should batch mode just skip these? */
1253: if ((fp = sshkey_fingerprint(sign_key,
1254: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1255: fatal_f("fingerprint failed");
1256: notifier = notify_start(options.batch_mode,
1257: "Confirm user presence for key %s %s",
1258: sshkey_type(sign_key), fp);
1259: free(fp);
1.272 djm 1260: }
1.310 djm 1261: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1262: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1263: debug_fr(r, "sshkey_sign");
1.360 djm 1264: if (!retried && pin == NULL && !is_agent &&
1265: sshkey_is_sk(sign_key) &&
1.341 djm 1266: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1267: notify_complete(notifier, NULL);
1268: notifier = NULL;
1.360 djm 1269: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1270: sshkey_type(sign_key), id->filename);
1271: pin = read_passphrase(prompt, 0);
1.341 djm 1272: retried = 1;
1273: goto retry_pin;
1274: }
1.309 djm 1275: goto out;
1276: }
1.341 djm 1277:
1.309 djm 1278: /*
1279: * PKCS#11 tokens may not support all signature algorithms,
1280: * so check what we get back.
1281: */
1282: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1283: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1284: goto out;
1.265 djm 1285: }
1.309 djm 1286: /* success */
1287: r = 0;
1288: out:
1.325 djm 1289: free(prompt);
1290: if (pin != NULL)
1291: freezero(pin, strlen(pin));
1.341 djm 1292: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1293: sshkey_free(prv);
1.269 djm 1294: return r;
1.51 markus 1295: }
1296:
1.76 itojun 1297: static int
1.255 djm 1298: id_filename_matches(Identity *id, Identity *private_id)
1299: {
1.356 djm 1300: static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
1.255 djm 1301: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1302: size_t i, slen;
1303:
1304: if (strcmp(id->filename, private_id->filename) == 0)
1305: return 1;
1306: for (i = 0; suffixes[i]; i++) {
1307: slen = strlen(suffixes[i]);
1308: if (len > slen && plen == len - slen &&
1309: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1310: memcmp(id->filename, private_id->filename, plen) == 0)
1311: return 1;
1312: }
1313: return 0;
1314: }
1315:
1316: static int
1.295 djm 1317: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1318: {
1.295 djm 1319: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1320: struct sshbuf *b = NULL;
1321: Identity *private_id, *sign_id = NULL;
1322: u_char *signature = NULL;
1323: size_t slen = 0, skip = 0;
1324: int r, fallback_sigtype, sent = 0;
1325: char *alg = NULL, *fp = NULL;
1.353 djm 1326: const char *loc = "", *method = "publickey";
1.354 djm 1327: int hostbound = 0;
1.353 djm 1328:
1329: /* prefer host-bound pubkey signatures if supported by server */
1.354 djm 1330: if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
1331: (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
1332: hostbound = 1;
1.353 djm 1333: method = "publickey-hostbound-v00@openssh.com";
1.354 djm 1334: }
1.1 markus 1335:
1.222 djm 1336: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1337: SSH_FP_DEFAULT)) == NULL)
1338: return 0;
1.51 markus 1339:
1.354 djm 1340: debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
1.1 markus 1341:
1.227 djm 1342: /*
1343: * If the key is an certificate, try to find a matching private key
1344: * and use it to complete the signature.
1.241 djm 1345: * If no such private key exists, fall back to trying the certificate
1346: * key itself in case it has a private half already loaded.
1.272 djm 1347: * This will try to set sign_id to the private key that will perform
1348: * the signature.
1.227 djm 1349: */
1.272 djm 1350: if (sshkey_is_cert(id->key)) {
1.227 djm 1351: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1352: if (sshkey_equal_public(id->key, private_id->key) &&
1353: id->key->type != private_id->key->type) {
1.272 djm 1354: sign_id = private_id;
1.227 djm 1355: break;
1356: }
1357: }
1.255 djm 1358: /*
1359: * Exact key matches are preferred, but also allow
1360: * filename matches for non-PKCS#11/agent keys that
1361: * didn't load public keys. This supports the case
1362: * of keeping just a private key file and public
1363: * certificate on disk.
1364: */
1.272 djm 1365: if (sign_id == NULL &&
1366: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1367: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1368: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1369: if (private_id->key == NULL &&
1370: id_filename_matches(id, private_id)) {
1.272 djm 1371: sign_id = private_id;
1.255 djm 1372: break;
1373: }
1374: }
1375: }
1.272 djm 1376: if (sign_id != NULL) {
1.331 djm 1377: debug2_f("using private key \"%s\"%s for "
1.349 djm 1378: "certificate", sign_id->filename,
1379: sign_id->agent_fd != -1 ? " from agent" : "");
1.227 djm 1380: } else {
1.331 djm 1381: debug_f("no separate private key for certificate "
1382: "\"%s\"", id->filename);
1.227 djm 1383: }
1384: }
1385:
1.272 djm 1386: /*
1387: * If the above didn't select another identity to do the signing
1388: * then default to the one we started with.
1389: */
1390: if (sign_id == NULL)
1391: sign_id = id;
1392:
1393: /* assemble and sign data */
1394: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1395: free(alg);
1396: slen = 0;
1397: signature = NULL;
1398: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1399: id->key)) == NULL) {
1.331 djm 1400: error_f("no mutual signature supported");
1.272 djm 1401: goto out;
1402: }
1.331 djm 1403: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1404:
1405: sshbuf_free(b);
1406: if ((b = sshbuf_new()) == NULL)
1.331 djm 1407: fatal_f("sshbuf_new failed");
1.345 djm 1408: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 djm 1409: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1410: fatal_fr(r, "sshbuf_putb");
1.272 djm 1411: } else {
1.346 djm 1412: if ((r = sshbuf_put_stringb(b,
1413: ssh->kex->session_id)) != 0)
1414: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1415: }
1.278 markus 1416: skip = sshbuf_len(b);
1.272 djm 1417: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1418: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1419: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.353 djm 1420: (r = sshbuf_put_cstring(b, method)) != 0 ||
1.272 djm 1421: (r = sshbuf_put_u8(b, 1)) != 0 ||
1422: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1423: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1424: fatal_fr(r, "assemble signed data");
1.272 djm 1425: }
1.354 djm 1426: if (hostbound) {
1.353 djm 1427: if (ssh->kex->initial_hostkey == NULL) {
1428: fatal_f("internal error: initial hostkey "
1429: "not recorded");
1430: }
1431: if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
1432: fatal_fr(r, "assemble %s hostkey", method);
1433: }
1.272 djm 1434: /* generate signature */
1435: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1436: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1437: if (r == 0)
1438: break;
1439: else if (r == SSH_ERR_KEY_NOT_FOUND)
1440: goto out; /* soft failure */
1441: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1442: !fallback_sigtype) {
1443: if (sign_id->agent_fd != -1)
1444: loc = "agent ";
1445: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1446: loc = "token ";
1447: logit("%skey %s %s returned incorrect signature type",
1448: loc, sshkey_type(id->key), fp);
1449: continue;
1450: }
1.331 djm 1451: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1452: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1453: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1454: goto out;
1.17 markus 1455: }
1.272 djm 1456: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1457: fatal_f("no signature");
1.51 markus 1458:
1.1 markus 1459: /* append signature */
1.272 djm 1460: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1461: fatal_fr(r, "append signature");
1.1 markus 1462:
1.272 djm 1463: #ifdef DEBUG_PK
1464: sshbuf_dump(b, stderr);
1465: #endif
1.1 markus 1466: /* skip session id and packet type */
1.272 djm 1467: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1468: fatal_fr(r, "consume");
1.1 markus 1469:
1470: /* put remaining data from buffer into packet */
1.272 djm 1471: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1472: (r = sshpkt_putb(ssh, b)) != 0 ||
1473: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1474: fatal_fr(r, "enqueue request");
1.272 djm 1475:
1476: /* success */
1477: sent = 1;
1.17 markus 1478:
1.272 djm 1479: out:
1480: free(fp);
1481: free(alg);
1482: sshbuf_free(b);
1483: freezero(signature, slen);
1484: return sent;
1.16 markus 1485: }
1486:
1.76 itojun 1487: static int
1.295 djm 1488: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1489: {
1.295 djm 1490: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1491: u_char *blob = NULL;
1492: char *alg = NULL;
1.278 markus 1493: size_t bloblen;
1494: u_int have_sig = 0;
1495: int sent = 0, r;
1.20 markus 1496:
1.272 djm 1497: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1498: debug_f("no mutual signature algorithm");
1.272 djm 1499: goto out;
1500: }
1.16 markus 1501:
1.278 markus 1502: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1503: /* we cannot handle this key */
1.331 djm 1504: debug3_f("cannot handle key");
1.272 djm 1505: goto out;
1.16 markus 1506: }
1.51 markus 1507: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1508: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1509:
1.278 markus 1510: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1511: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1512: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1513: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1514: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1515: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1516: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1517: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1518: fatal_fr(r, "send packet");
1.272 djm 1519: sent = 1;
1.278 markus 1520:
1521: out:
1.272 djm 1522: free(alg);
1.197 djm 1523: free(blob);
1.272 djm 1524: return sent;
1.51 markus 1525: }
1526:
1.259 markus 1527: static struct sshkey *
1.229 jcs 1528: load_identity_file(Identity *id)
1.51 markus 1529: {
1.259 markus 1530: struct sshkey *private = NULL;
1.229 jcs 1531: char prompt[300], *passphrase, *comment;
1.308 dtucker 1532: int r, quit = 0, i;
1.52 markus 1533: struct stat st;
1.16 markus 1534:
1.306 deraadt 1535: if (stat(id->filename, &st) == -1) {
1.330 djm 1536: do_log2(id->userprovided ?
1537: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1538: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1539: return NULL;
1540: }
1.214 djm 1541: snprintf(prompt, sizeof prompt,
1.229 jcs 1542: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1543: for (i = 0; i <= options.number_of_password_prompts; i++) {
1544: if (i == 0)
1545: passphrase = "";
1546: else {
1.20 markus 1547: passphrase = read_passphrase(prompt, 0);
1.214 djm 1548: if (*passphrase == '\0') {
1.20 markus 1549: debug2("no passphrase given, try next key");
1.214 djm 1550: free(passphrase);
1551: break;
1552: }
1553: }
1.229 jcs 1554: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1555: passphrase, &private, &comment))) {
1.214 djm 1556: case 0:
1557: break;
1558: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1559: if (options.batch_mode) {
1560: quit = 1;
1561: break;
1562: }
1.215 djm 1563: if (i != 0)
1564: debug2("bad passphrase given, try again...");
1.214 djm 1565: break;
1566: case SSH_ERR_SYSTEM_ERROR:
1567: if (errno == ENOENT) {
1.331 djm 1568: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1569: quit = 1;
1.214 djm 1570: break;
1.20 markus 1571: }
1.214 djm 1572: /* FALLTHROUGH */
1573: default:
1.331 djm 1574: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1575: quit = 1;
1576: break;
1577: }
1.311 markus 1578: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1579: options.sk_provider == NULL) {
1.319 naddy 1580: debug("key \"%s\" is an authenticator-hosted key, "
1581: "but no provider specified", id->filename);
1.309 djm 1582: sshkey_free(private);
1583: private = NULL;
1584: quit = 1;
1585: }
1.361 djm 1586: if (!quit && (r = sshkey_check_rsa_length(private,
1587: options.required_rsa_size)) != 0) {
1588: debug_fr(r, "Skipping key %s", id->filename);
1589: sshkey_free(private);
1590: private = NULL;
1591: quit = 1;
1592: }
1.230 djm 1593: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1594: !(id->key && id->isprivate))
1595: maybe_add_key_to_agent(id->filename, private, comment,
1596: passphrase);
1.278 markus 1597: if (i > 0)
1598: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1599: free(comment);
1.214 djm 1600: if (private != NULL || quit)
1601: break;
1.16 markus 1602: }
1.51 markus 1603: return private;
1604: }
1605:
1.272 djm 1606: static int
1607: key_type_allowed_by_config(struct sshkey *key)
1608: {
1609: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1610: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1611: return 1;
1612:
1613: /* RSA keys/certs might be allowed by alternate signature types */
1614: switch (key->type) {
1615: case KEY_RSA:
1616: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1617: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1618: return 1;
1619: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1620: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1621: return 1;
1622: break;
1623: case KEY_RSA_CERT:
1624: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1625: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1626: return 1;
1627: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1628: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1629: return 1;
1630: break;
1631: }
1632: return 0;
1633: }
1634:
1.352 djm 1635: /* obtain a list of keys from the agent */
1636: static int
1637: get_agent_identities(struct ssh *ssh, int *agent_fdp,
1638: struct ssh_identitylist **idlistp)
1639: {
1640: int r, agent_fd;
1641: struct ssh_identitylist *idlist;
1642:
1643: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1644: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1645: debug_fr(r, "ssh_get_authentication_socket");
1646: return r;
1647: }
1648: if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
1649: ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
1650: debug_f("bound agent to hostkey");
1651: else
1652: debug2_fr(r, "ssh_agent_bind_hostkey");
1653:
1654: if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1655: debug_fr(r, "ssh_fetch_identitylist");
1656: close(agent_fd);
1657: return r;
1658: }
1659: /* success */
1660: *agent_fdp = agent_fd;
1661: *idlistp = idlist;
1662: debug_f("agent returned %zu keys", idlist->nkeys);
1663: return 0;
1664: }
1.272 djm 1665:
1.117 markus 1666: /*
1667: * try keys in the following order:
1.332 djm 1668: * 1. certificates listed in the config file
1669: * 2. other input certificates
1.227 djm 1670: * 3. agent keys that are found in the config file
1671: * 4. other agent keys
1672: * 5. keys that are only listed in the config file
1.117 markus 1673: */
1674: static void
1.352 djm 1675: pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
1.51 markus 1676: {
1.214 djm 1677: struct identity *id, *id2, *tmp;
1678: struct idlist agent, files, *preferred;
1679: struct sshkey *key;
1.230 djm 1680: int agent_fd = -1, i, r, found;
1.214 djm 1681: size_t j;
1682: struct ssh_identitylist *idlist;
1.287 djm 1683: char *ident;
1.51 markus 1684:
1.117 markus 1685: TAILQ_INIT(&agent); /* keys from the agent */
1686: TAILQ_INIT(&files); /* keys from the config file */
1687: preferred = &authctxt->keys;
1688: TAILQ_INIT(preferred); /* preferred order of keys */
1689:
1.190 djm 1690: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1691: for (i = 0; i < options.num_identity_files; i++) {
1692: key = options.identity_keys[i];
1.309 djm 1693: if (key && key->cert &&
1694: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1695: debug_f("ignoring certificate %s: not a user "
1696: "certificate", options.identity_files[i]);
1.309 djm 1697: continue;
1698: }
1.311 markus 1699: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1700: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1701: "SecurityKeyProvider has been specified",
1.331 djm 1702: options.identity_files[i]);
1.117 markus 1703: continue;
1.309 djm 1704: }
1.117 markus 1705: options.identity_keys[i] = NULL;
1.150 djm 1706: id = xcalloc(1, sizeof(*id));
1.230 djm 1707: id->agent_fd = -1;
1.117 markus 1708: id->key = key;
1709: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1710: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1711: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1712: }
1.227 djm 1713: /* list of certificates specified by user */
1714: for (i = 0; i < options.num_certificate_files; i++) {
1715: key = options.certificates[i];
1.278 markus 1716: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1717: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1718: debug_f("ignoring certificate %s: not a user "
1719: "certificate", options.identity_files[i]);
1.227 djm 1720: continue;
1.309 djm 1721: }
1.311 markus 1722: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1723: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1724: "certificate %s as no "
1.309 djm 1725: "SecurityKeyProvider has been specified",
1.331 djm 1726: options.identity_files[i]);
1.309 djm 1727: continue;
1728: }
1.227 djm 1729: id = xcalloc(1, sizeof(*id));
1.230 djm 1730: id->agent_fd = -1;
1.227 djm 1731: id->key = key;
1732: id->filename = xstrdup(options.certificate_files[i]);
1733: id->userprovided = options.certificate_file_userprovided[i];
1734: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1735: }
1736: /* list of keys supported by the agent */
1.352 djm 1737: if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
1.214 djm 1738: for (j = 0; j < idlist->nkeys; j++) {
1.361 djm 1739: if ((r = sshkey_check_rsa_length(idlist->keys[j],
1740: options.required_rsa_size)) != 0) {
1741: debug_fr(r, "ignoring %s agent key",
1742: sshkey_ssh_name(idlist->keys[j]));
1743: continue;
1744: }
1.117 markus 1745: found = 0;
1746: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1747: /*
1748: * agent keys from the config file are
1749: * preferred
1750: */
1751: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1752: TAILQ_REMOVE(&files, id, next);
1753: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1754: id->agent_fd = agent_fd;
1.117 markus 1755: found = 1;
1756: break;
1757: }
1758: }
1.135 markus 1759: if (!found && !options.identities_only) {
1.150 djm 1760: id = xcalloc(1, sizeof(*id));
1.214 djm 1761: /* XXX "steals" key/comment from idlist */
1762: id->key = idlist->keys[j];
1763: id->filename = idlist->comments[j];
1764: idlist->keys[j] = NULL;
1765: idlist->comments[j] = NULL;
1766: id->agent_fd = agent_fd;
1.117 markus 1767: TAILQ_INSERT_TAIL(&agent, id, next);
1768: }
1769: }
1.214 djm 1770: ssh_free_identitylist(idlist);
1.117 markus 1771: /* append remaining agent keys */
1.324 bket 1772: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1773: authctxt->agent_fd = agent_fd;
1.244 djm 1774: }
1775: /* Prefer PKCS11 keys that are explicitly listed */
1776: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1777: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1778: continue;
1779: found = 0;
1780: TAILQ_FOREACH(id2, &files, next) {
1781: if (id2->key == NULL ||
1.321 djm 1782: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1783: continue;
1784: if (sshkey_equal(id->key, id2->key)) {
1785: TAILQ_REMOVE(&files, id, next);
1786: TAILQ_INSERT_TAIL(preferred, id, next);
1787: found = 1;
1788: break;
1789: }
1790: }
1791: /* If IdentitiesOnly set and key not found then don't use it */
1792: if (!found && options.identities_only) {
1793: TAILQ_REMOVE(&files, id, next);
1.278 markus 1794: freezero(id, sizeof(*id));
1.244 djm 1795: }
1.117 markus 1796: }
1797: /* append remaining keys from the config file */
1.324 bket 1798: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1799: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1800: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1801: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1802: debug("Skipping %s key %s - "
1.342 dtucker 1803: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1804: sshkey_ssh_name(id->key), id->filename);
1805: TAILQ_REMOVE(preferred, id, next);
1806: sshkey_free(id->key);
1807: free(id->filename);
1808: memset(id, 0, sizeof(*id));
1809: continue;
1810: }
1.117 markus 1811: }
1.287 djm 1812: /* List the keys we plan on using */
1813: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1814: ident = format_identity(id);
1815: debug("Will attempt key: %s", ident);
1816: free(ident);
1817: }
1.331 djm 1818: debug2_f("done");
1.17 markus 1819: }
1820:
1.117 markus 1821: static void
1.303 djm 1822: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1823: {
1.302 djm 1824: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1825: Identity *id;
1.51 markus 1826:
1.289 djm 1827: if (authctxt->agent_fd != -1) {
1.214 djm 1828: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1829: authctxt->agent_fd = -1;
1830: }
1.117 markus 1831: for (id = TAILQ_FIRST(&authctxt->keys); id;
1832: id = TAILQ_FIRST(&authctxt->keys)) {
1833: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1834: sshkey_free(id->key);
1.197 djm 1835: free(id->filename);
1836: free(id);
1.117 markus 1837: }
1.1 markus 1838: }
1839:
1.251 djm 1840: static void
1841: pubkey_reset(Authctxt *authctxt)
1842: {
1843: Identity *id;
1844:
1845: TAILQ_FOREACH(id, &authctxt->keys, next)
1846: id->tried = 0;
1847: }
1848:
1.225 markus 1849: static int
1.295 djm 1850: userauth_pubkey(struct ssh *ssh)
1.20 markus 1851: {
1.295 djm 1852: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1853: Identity *id;
1.20 markus 1854: int sent = 0;
1.287 djm 1855: char *ident;
1.20 markus 1856:
1.117 markus 1857: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1858: if (id->tried++)
1859: return (0);
1.127 markus 1860: /* move key to the end of the queue */
1.117 markus 1861: TAILQ_REMOVE(&authctxt->keys, id, next);
1862: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1863: /*
1864: * send a test message if we have the public key. for
1865: * encrypted keys we cannot do this and have to load the
1866: * private key instead
1867: */
1.200 djm 1868: if (id->key != NULL) {
1.367 dtucker 1869: ident = format_identity(id);
1870: debug("Offering public key: %s", ident);
1871: free(ident);
1872: sent = send_pubkey_test(ssh, id);
1.200 djm 1873: } else {
1.117 markus 1874: debug("Trying private key: %s", id->filename);
1.229 jcs 1875: id->key = load_identity_file(id);
1.117 markus 1876: if (id->key != NULL) {
1.362 dtucker 1877: if (id->key != NULL) {
1.225 markus 1878: id->isprivate = 1;
1.295 djm 1879: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1880: }
1.278 markus 1881: sshkey_free(id->key);
1.117 markus 1882: id->key = NULL;
1.251 djm 1883: id->isprivate = 0;
1.51 markus 1884: }
1885: }
1.117 markus 1886: if (sent)
1887: return (sent);
1.28 markus 1888: }
1.117 markus 1889: return (0);
1.20 markus 1890: }
1891:
1.23 markus 1892: /*
1893: * Send userauth request message specifying keyboard-interactive method.
1894: */
1.302 djm 1895: static int
1.295 djm 1896: userauth_kbdint(struct ssh *ssh)
1.23 markus 1897: {
1.295 djm 1898: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1899: int r;
1.23 markus 1900:
1.292 djm 1901: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1902: return 0;
1.82 markus 1903: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1904: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1905: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1906: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1907: return 0;
1908: }
1.23 markus 1909:
1910: debug2("userauth_kbdint");
1.278 markus 1911: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1912: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1913: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1914: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1915: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1916: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1917: options.kbd_interactive_devices : "")) != 0 ||
1918: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1919: fatal_fr(r, "send packet");
1.23 markus 1920:
1.278 markus 1921: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1922: return 1;
1923: }
1924:
1925: /*
1.46 markus 1926: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1927: */
1.302 djm 1928: static int
1.261 markus 1929: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1930: {
1.260 markus 1931: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1932: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1933: char *display_prompt = NULL, *response = NULL;
1.278 markus 1934: u_char echo = 0;
1.32 markus 1935: u_int num_prompts, i;
1.278 markus 1936: int r;
1.23 markus 1937:
1.335 djm 1938: debug2_f("entering");
1.23 markus 1939:
1940: if (authctxt == NULL)
1.335 djm 1941: fatal_f("no authentication context");
1.82 markus 1942:
1943: authctxt->info_req_seen = 1;
1.23 markus 1944:
1.278 markus 1945: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1946: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1947: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1948: goto out;
1.23 markus 1949: if (strlen(name) > 0)
1.116 itojun 1950: logit("%s", name);
1.23 markus 1951: if (strlen(inst) > 0)
1.116 itojun 1952: logit("%s", inst);
1.23 markus 1953:
1.278 markus 1954: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1955: goto out;
1.23 markus 1956: /*
1957: * Begin to build info response packet based on prompts requested.
1958: * We commit to providing the correct number of responses, so if
1959: * further on we run into a problem that prevents this, we have to
1960: * be sure and clean this up and send a correct error response.
1961: */
1.278 markus 1962: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1963: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1964: goto out;
1.23 markus 1965:
1.335 djm 1966: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1967: for (i = 0; i < num_prompts; i++) {
1.278 markus 1968: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1969: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1970: goto out;
1.336 djm 1971: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1972: authctxt->server_user, options.host_key_alias ?
1.336 djm 1973: options.host_key_alias : authctxt->host, prompt) == -1)
1974: fatal_f("asmprintf failed");
1.335 djm 1975: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1976: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1977: goto out;
1978: freezero(response, strlen(response));
1.197 djm 1979: free(prompt);
1.335 djm 1980: free(display_prompt);
1981: display_prompt = response = prompt = NULL;
1.23 markus 1982: }
1.278 markus 1983: /* done with parsing incoming message. */
1984: if ((r = sshpkt_get_end(ssh)) != 0 ||
1985: (r = sshpkt_add_padding(ssh, 64)) != 0)
1986: goto out;
1987: r = sshpkt_send(ssh);
1988: out:
1989: if (response)
1990: freezero(response, strlen(response));
1991: free(prompt);
1.335 djm 1992: free(display_prompt);
1.278 markus 1993: free(name);
1994: free(inst);
1995: free(lang);
1996: return r;
1.68 markus 1997: }
1998:
1.100 markus 1999: static int
1.294 djm 2000: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 2001: const u_char *data, size_t datalen)
1.100 markus 2002: {
1.223 djm 2003: struct sshbuf *b;
1.101 markus 2004: struct stat st;
1.100 markus 2005: pid_t pid;
1.304 deraadt 2006: int r, to[2], from[2], status;
1.295 djm 2007: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 2008: u_char rversion = 0, version = 2;
2009: void (*osigchld)(int);
1.100 markus 2010:
1.223 djm 2011: *sigp = NULL;
2012: *lenp = 0;
1.100 markus 2013:
1.306 deraadt 2014: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 2015: error_f("not installed: %s", strerror(errno));
1.223 djm 2016: return -1;
2017: }
2018: if (fflush(stdout) != 0) {
1.331 djm 2019: error_f("fflush: %s", strerror(errno));
1.101 markus 2020: return -1;
2021: }
1.306 deraadt 2022: if (pipe(to) == -1) {
1.331 djm 2023: error_f("pipe: %s", strerror(errno));
1.100 markus 2024: return -1;
2025: }
1.306 deraadt 2026: if (pipe(from) == -1) {
1.331 djm 2027: error_f("pipe: %s", strerror(errno));
1.100 markus 2028: return -1;
2029: }
1.306 deraadt 2030: if ((pid = fork()) == -1) {
1.331 djm 2031: error_f("fork: %s", strerror(errno));
1.100 markus 2032: return -1;
2033: }
1.317 dtucker 2034: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 2035: if (pid == 0) {
2036: close(from[0]);
1.306 deraadt 2037: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2038: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2039: close(to[1]);
1.306 deraadt 2040: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2041: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2042: close(from[1]);
2043: close(to[0]);
1.304 deraadt 2044:
1.306 deraadt 2045: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2046: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2047: sock = STDERR_FILENO + 1;
1.363 dtucker 2048: if (fcntl(sock, F_SETFD, 0) == -1) /* keep the socket on exec */
2049: debug3_f("fcntl F_SETFD: %s", strerror(errno));
1.223 djm 2050: closefrom(sock + 1);
1.304 deraadt 2051:
1.331 djm 2052: debug3_f("[child] pid=%ld, exec %s",
2053: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2054: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2055: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2056: strerror(errno));
2057: }
2058: close(from[1]);
2059: close(to[0]);
1.305 djm 2060: sock = STDERR_FILENO + 1;
1.100 markus 2061:
1.223 djm 2062: if ((b = sshbuf_new()) == NULL)
1.331 djm 2063: fatal_f("sshbuf_new failed");
1.223 djm 2064: /* send # of sock, data to be signed */
1.253 djm 2065: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2066: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2067: fatal_fr(r, "buffer error");
1.223 djm 2068: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2069: fatal_f("couldn't send request");
1.223 djm 2070: sshbuf_reset(b);
2071: r = ssh_msg_recv(from[0], b);
1.101 markus 2072: close(from[0]);
2073: close(to[1]);
1.223 djm 2074: if (r < 0) {
1.331 djm 2075: error_f("no reply");
1.223 djm 2076: goto fail;
2077: }
1.101 markus 2078:
1.223 djm 2079: errno = 0;
1.306 deraadt 2080: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2081: if (errno != EINTR) {
1.331 djm 2082: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2083: goto fail;
2084: }
2085: }
2086: if (!WIFEXITED(status)) {
1.331 djm 2087: error_f("exited abnormally");
1.223 djm 2088: goto fail;
2089: }
2090: if (WEXITSTATUS(status) != 0) {
1.331 djm 2091: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2092: goto fail;
2093: }
2094: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2095: error_fr(r, "buffer error");
1.223 djm 2096: goto fail;
2097: }
2098: if (rversion != version) {
1.331 djm 2099: error_f("bad version");
1.223 djm 2100: goto fail;
2101: }
2102: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2103: error_fr(r, "buffer error");
1.223 djm 2104: fail:
1.317 dtucker 2105: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2106: sshbuf_free(b);
1.100 markus 2107: return -1;
2108: }
1.317 dtucker 2109: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2110: sshbuf_free(b);
1.100 markus 2111:
2112: return 0;
2113: }
2114:
1.302 djm 2115: static int
1.295 djm 2116: userauth_hostbased(struct ssh *ssh)
1.68 markus 2117: {
1.295 djm 2118: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2119: struct sshkey *private = NULL;
2120: struct sshbuf *b = NULL;
2121: u_char *sig = NULL, *keyblob = NULL;
2122: char *fp = NULL, *chost = NULL, *lname = NULL;
2123: size_t siglen = 0, keylen = 0;
2124: int i, r, success = 0;
2125:
2126: if (authctxt->ktypes == NULL) {
1.344 dtucker 2127: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2128: authctxt->ktypes = authctxt->oktypes;
2129: }
1.213 djm 2130:
1.223 djm 2131: /*
1.344 dtucker 2132: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2133: * trying each hostkey that matches the type in turn.
2134: */
2135: for (;;) {
2136: if (authctxt->active_ktype == NULL)
2137: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2138: if (authctxt->active_ktype == NULL ||
2139: *authctxt->active_ktype == '\0')
2140: break;
1.331 djm 2141: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2142:
1.223 djm 2143: /* check for a useful key */
2144: private = NULL;
2145: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2146: if (authctxt->sensitive->keys[i] == NULL ||
2147: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2148: continue;
1.355 djm 2149: if (!sshkey_match_keyname_to_sigalgs(
1.223 djm 2150: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.355 djm 2151: authctxt->active_ktype))
1.223 djm 2152: continue;
1.68 markus 2153: /* we take and free the key */
1.223 djm 2154: private = authctxt->sensitive->keys[i];
2155: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2156: break;
2157: }
1.223 djm 2158: /* Found one */
2159: if (private != NULL)
2160: break;
2161: /* No more keys of this type; advance */
2162: authctxt->active_ktype = NULL;
1.68 markus 2163: }
1.223 djm 2164: if (private == NULL) {
2165: free(authctxt->oktypes);
2166: authctxt->oktypes = authctxt->ktypes = NULL;
2167: authctxt->active_ktype = NULL;
1.109 markus 2168: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2169: goto out;
1.68 markus 2170: }
1.211 djm 2171:
1.223 djm 2172: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2173: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2174: error_f("sshkey_fingerprint failed");
1.223 djm 2175: goto out;
1.68 markus 2176: }
1.355 djm 2177: debug_f("trying hostkey %s %s using sigalg %s",
2178: sshkey_ssh_name(private), fp, authctxt->active_ktype);
1.211 djm 2179:
1.84 markus 2180: /* figure out a name for the client host */
1.295 djm 2181: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2182: if (lname == NULL) {
1.331 djm 2183: error_f("cannot get local ipaddr/name");
1.223 djm 2184: goto out;
1.84 markus 2185: }
1.223 djm 2186:
2187: /* XXX sshbuf_put_stringf? */
2188: xasprintf(&chost, "%s.", lname);
1.331 djm 2189: debug2_f("chost %s", chost);
1.84 markus 2190:
1.68 markus 2191: /* construct data */
1.223 djm 2192: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2193: error_f("sshbuf_new failed");
1.223 djm 2194: goto out;
2195: }
2196: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2197: error_fr(r, "sshkey_to_blob");
1.223 djm 2198: goto out;
2199: }
1.346 djm 2200: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2201: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2202: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2203: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2204: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2205: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2206: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2207: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2208: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2209: error_fr(r, "buffer error");
1.223 djm 2210: goto out;
2211: }
2212:
1.68 markus 2213: #ifdef DEBUG_PK
1.223 djm 2214: sshbuf_dump(b, stderr);
1.68 markus 2215: #endif
1.294 djm 2216: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2217: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2218: error("sign using hostkey %s %s failed",
2219: sshkey_ssh_name(private), fp);
2220: goto out;
2221: }
2222: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2223: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2224: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2225: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2226: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2227: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2228: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2229: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2230: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2231: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2232: error_fr(r, "packet error");
1.223 djm 2233: goto out;
2234: }
2235: success = 1;
2236:
2237: out:
1.278 markus 2238: if (sig != NULL)
2239: freezero(sig, siglen);
1.223 djm 2240: free(keyblob);
2241: free(lname);
2242: free(fp);
1.197 djm 2243: free(chost);
1.223 djm 2244: sshkey_free(private);
2245: sshbuf_free(b);
1.68 markus 2246:
1.223 djm 2247: return success;
1.23 markus 2248: }
1.170 djm 2249:
1.20 markus 2250: /* find auth method */
2251:
2252: /*
2253: * given auth method name, if configurable options permit this method fill
2254: * in auth_ident field and return true, otherwise return false.
2255: */
1.76 itojun 2256: static int
1.20 markus 2257: authmethod_is_enabled(Authmethod *method)
2258: {
2259: if (method == NULL)
2260: return 0;
2261: /* return false if options indicate this method is disabled */
2262: if (method->enabled == NULL || *method->enabled == 0)
2263: return 0;
2264: /* return false if batch mode is enabled but method needs interactive mode */
2265: if (method->batch_flag != NULL && *method->batch_flag != 0)
2266: return 0;
2267: return 1;
2268: }
2269:
1.76 itojun 2270: static Authmethod *
1.20 markus 2271: authmethod_lookup(const char *name)
1.1 markus 2272: {
1.20 markus 2273: Authmethod *method = NULL;
2274: if (name != NULL)
2275: for (method = authmethods; method->name != NULL; method++)
2276: if (strcmp(name, method->name) == 0)
2277: return method;
2278: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2279: return NULL;
2280: }
1.1 markus 2281:
1.53 markus 2282: /* XXX internal state */
2283: static Authmethod *current = NULL;
2284: static char *supported = NULL;
2285: static char *preferred = NULL;
1.105 deraadt 2286:
1.20 markus 2287: /*
2288: * Given the authentication method list sent by the server, return the
2289: * next method we should try. If the server initially sends a nil list,
1.67 markus 2290: * use a built-in default list.
1.41 stevesk 2291: */
1.76 itojun 2292: static Authmethod *
1.20 markus 2293: authmethod_get(char *authlist)
2294: {
1.53 markus 2295: char *name = NULL;
1.97 markus 2296: u_int next;
1.41 stevesk 2297:
1.20 markus 2298: /* Use a suitable default if we're passed a nil list. */
2299: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2300: authlist = options.preferred_authentications;
1.20 markus 2301:
1.53 markus 2302: if (supported == NULL || strcmp(authlist, supported) != 0) {
2303: debug3("start over, passed a different list %s", authlist);
1.197 djm 2304: free(supported);
1.53 markus 2305: supported = xstrdup(authlist);
2306: preferred = options.preferred_authentications;
2307: debug3("preferred %s", preferred);
2308: current = NULL;
2309: } else if (current != NULL && authmethod_is_enabled(current))
2310: return current;
1.20 markus 2311:
1.53 markus 2312: for (;;) {
2313: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2314: debug("No more authentication methods to try.");
1.53 markus 2315: current = NULL;
2316: return NULL;
2317: }
2318: preferred += next;
1.23 markus 2319: debug3("authmethod_lookup %s", name);
1.53 markus 2320: debug3("remaining preferred: %s", preferred);
2321: if ((current = authmethod_lookup(name)) != NULL &&
2322: authmethod_is_enabled(current)) {
1.23 markus 2323: debug3("authmethod_is_enabled %s", name);
1.109 markus 2324: debug("Next authentication method: %s", name);
1.197 djm 2325: free(name);
1.53 markus 2326: return current;
1.23 markus 2327: }
1.198 dtucker 2328: free(name);
1.1 markus 2329: }
1.53 markus 2330: }
1.1 markus 2331:
1.79 stevesk 2332: static char *
1.53 markus 2333: authmethods_get(void)
2334: {
2335: Authmethod *method = NULL;
1.278 markus 2336: struct sshbuf *b;
1.93 markus 2337: char *list;
1.278 markus 2338: int r;
1.27 provos 2339:
1.278 markus 2340: if ((b = sshbuf_new()) == NULL)
1.331 djm 2341: fatal_f("sshbuf_new failed");
1.53 markus 2342: for (method = authmethods; method->name != NULL; method++) {
2343: if (authmethod_is_enabled(method)) {
1.278 markus 2344: if ((r = sshbuf_putf(b, "%s%s",
2345: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2346: fatal_fr(r, "buffer error");
1.53 markus 2347: }
2348: }
1.278 markus 2349: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2350: fatal_f("sshbuf_dup_string failed");
1.278 markus 2351: sshbuf_free(b);
1.93 markus 2352: return list;
1.1 markus 2353: }
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