Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.364
1.364 ! dtucker 1: /* $OpenBSD: sshconnect2.c,v 1.363 2023/03/03 02:34:29 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;
! 220: int r;
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:
230: /* Expand or fill in HostkeyAlgorithms */
231: all_key = sshkey_alg_list(0, 0, 1, ',');
1.333 djm 232: if ((r = kex_assemble_names(&options.hostkeyalgorithms,
233: kex_default_pk_alg(), all_key)) != 0)
234: fatal_fr(r, "kex_assemble_namelist");
1.320 djm 235: free(all_key);
236:
1.231 markus 237: if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
1.331 djm 238: fatal_f("kex_names_cat");
1.115 markus 239:
1.364 ! dtucker 240: /*
! 241: * If the user has not specified HostkeyAlgorithms, or has only
! 242: * appended or removed algorithms from that list then prefer algorithms
! 243: * that are in the list that are supported by known_hosts keys.
! 244: */
! 245: if (options.hostkeyalgorithms == NULL ||
! 246: options.hostkeyalgorithms[0] == '-' ||
! 247: options.hostkeyalgorithms[0] == '+')
! 248: hkalgs = order_hostkeyalgs(host, hostaddr, port, cinfo);
! 249:
! 250: kex_proposal_populate_entries(ssh, myproposal, s, options.ciphers,
! 251: options.macs, compression_alg_list(options.compression),
! 252: hkalgs ? hkalgs : options.hostkeyalgorithms);
! 253:
! 254: free(hkalgs);
1.22 provos 255:
1.65 markus 256: /* start key exchange */
1.291 djm 257: if ((r = kex_setup(ssh, myproposal)) != 0)
1.331 djm 258: fatal_r(r, "kex_setup");
1.207 markus 259: #ifdef WITH_OPENSSL
1.301 djm 260: ssh->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_client;
261: ssh->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_client;
262: ssh->kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_client;
263: ssh->kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_client;
264: ssh->kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_client;
1.291 djm 265: ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
266: ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
1.301 djm 267: ssh->kex->kex[KEX_ECDH_SHA2] = kex_gen_client;
1.207 markus 268: #endif
1.301 djm 269: ssh->kex->kex[KEX_C25519_SHA256] = kex_gen_client;
1.340 djm 270: ssh->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_client;
1.291 djm 271: ssh->kex->verify_host_key=&verify_host_key_callback;
1.22 provos 272:
1.291 djm 273: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done);
1.173 andreas 274:
1.231 markus 275: /* remove ext-info from the KEX proposals for rekeying */
1.364 ! dtucker 276: free(myproposal[PROPOSAL_KEX_ALGS]);
1.231 markus 277: myproposal[PROPOSAL_KEX_ALGS] =
1.345 djm 278: compat_kex_proposal(ssh, options.kex_algorithms);
1.291 djm 279: if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0)
1.331 djm 280: fatal_r(r, "kex_prop2buf");
1.62 markus 281:
1.22 provos 282: #ifdef DEBUG_KEXDH
283: /* send 1st encrypted/maced/compressed message */
1.278 markus 284: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
285: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
1.280 markus 286: (r = sshpkt_send(ssh)) != 0 ||
287: (r = ssh_packet_write_wait(ssh)) != 0)
1.331 djm 288: fatal_fr(r, "send packet");
1.22 provos 289: #endif
1.364 ! dtucker 290: kex_proposal_free_entries(myproposal);
1.1 markus 291: }
1.11 markus 292:
1.1 markus 293: /*
294: * Authenticate user
295: */
1.20 markus 296:
1.214 djm 297: typedef struct cauthctxt Authctxt;
298: typedef struct cauthmethod Authmethod;
1.117 markus 299: typedef struct identity Identity;
300: typedef struct idlist Idlist;
1.20 markus 301:
1.117 markus 302: struct identity {
303: TAILQ_ENTRY(identity) next;
1.214 djm 304: int agent_fd; /* >=0 if agent supports key */
305: struct sshkey *key; /* public/private key */
1.117 markus 306: char *filename; /* comment for agent-only keys */
307: int tried;
308: int isprivate; /* key points to the private key */
1.191 dtucker 309: int userprovided;
1.117 markus 310: };
311: TAILQ_HEAD(idlist, identity);
1.20 markus 312:
1.214 djm 313: struct cauthctxt {
1.20 markus 314: const char *server_user;
1.68 markus 315: const char *local_user;
1.20 markus 316: const char *host;
317: const char *service;
1.214 djm 318: struct cauthmethod *method;
1.183 djm 319: sig_atomic_t success;
1.51 markus 320: char *authlist;
1.302 djm 321: #ifdef GSSAPI
322: /* gssapi */
323: gss_OID_set gss_supported_mechs;
324: u_int mech_tried;
325: #endif
1.68 markus 326: /* pubkey */
1.214 djm 327: struct idlist keys;
328: int agent_fd;
1.68 markus 329: /* hostbased */
1.100 markus 330: Sensitive *sensitive;
1.223 djm 331: char *oktypes, *ktypes;
332: const char *active_ktype;
1.82 markus 333: /* kbd-interactive */
334: int info_req_seen;
1.292 djm 335: int attempt_kbdint;
336: /* password */
337: int attempt_passwd;
1.121 markus 338: /* generic */
339: void *methoddata;
1.20 markus 340: };
1.214 djm 341:
342: struct cauthmethod {
1.20 markus 343: char *name; /* string to compare against server's list */
1.295 djm 344: int (*userauth)(struct ssh *ssh);
345: void (*cleanup)(struct ssh *ssh);
1.20 markus 346: int *enabled; /* flag in option struct that enables method */
347: int *batch_flag; /* flag in option struct that disables method */
348: };
349:
1.302 djm 350: static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
351: static int input_userauth_ext_info(int, u_int32_t, struct ssh *);
352: static int input_userauth_success(int, u_int32_t, struct ssh *);
353: static int input_userauth_failure(int, u_int32_t, struct ssh *);
354: static int input_userauth_banner(int, u_int32_t, struct ssh *);
355: static int input_userauth_error(int, u_int32_t, struct ssh *);
356: static int input_userauth_info_req(int, u_int32_t, struct ssh *);
357: static int input_userauth_pk_ok(int, u_int32_t, struct ssh *);
358: static int input_userauth_passwd_changereq(int, u_int32_t, struct ssh *);
359:
360: static int userauth_none(struct ssh *);
361: static int userauth_pubkey(struct ssh *);
362: static int userauth_passwd(struct ssh *);
363: static int userauth_kbdint(struct ssh *);
364: static int userauth_hostbased(struct ssh *);
1.20 markus 365:
1.121 markus 366: #ifdef GSSAPI
1.302 djm 367: static int userauth_gssapi(struct ssh *);
368: static void userauth_gssapi_cleanup(struct ssh *);
369: static int input_gssapi_response(int type, u_int32_t, struct ssh *);
370: static int input_gssapi_token(int type, u_int32_t, struct ssh *);
371: static int input_gssapi_error(int, u_int32_t, struct ssh *);
372: static int input_gssapi_errtok(int, u_int32_t, struct ssh *);
1.121 markus 373: #endif
374:
1.295 djm 375: void userauth(struct ssh *, char *);
1.51 markus 376:
1.303 djm 377: static void pubkey_cleanup(struct ssh *);
1.295 djm 378: static int sign_and_send_pubkey(struct ssh *ssh, Identity *);
1.352 djm 379: static void pubkey_prepare(struct ssh *, Authctxt *);
1.251 djm 380: static void pubkey_reset(Authctxt *);
1.259 markus 381: static struct sshkey *load_identity_file(Identity *);
1.76 itojun 382:
383: static Authmethod *authmethod_get(char *authlist);
384: static Authmethod *authmethod_lookup(const char *name);
385: static char *authmethods_get(void);
1.20 markus 386:
387: Authmethod authmethods[] = {
1.121 markus 388: #ifdef GSSAPI
1.132 markus 389: {"gssapi-with-mic",
1.121 markus 390: userauth_gssapi,
1.302 djm 391: userauth_gssapi_cleanup,
1.121 markus 392: &options.gss_authentication,
393: NULL},
394: #endif
1.81 markus 395: {"hostbased",
396: userauth_hostbased,
1.170 djm 397: NULL,
1.81 markus 398: &options.hostbased_authentication,
399: NULL},
1.20 markus 400: {"publickey",
401: userauth_pubkey,
1.303 djm 402: NULL,
1.28 markus 403: &options.pubkey_authentication,
1.20 markus 404: NULL},
1.81 markus 405: {"keyboard-interactive",
406: userauth_kbdint,
1.170 djm 407: NULL,
1.81 markus 408: &options.kbd_interactive_authentication,
409: &options.batch_mode},
1.20 markus 410: {"password",
411: userauth_passwd,
1.170 djm 412: NULL,
1.20 markus 413: &options.password_authentication,
1.23 markus 414: &options.batch_mode},
415: {"none",
416: userauth_none,
417: NULL,
1.170 djm 418: NULL,
1.23 markus 419: NULL},
1.170 djm 420: {NULL, NULL, NULL, NULL, NULL}
1.20 markus 421: };
422:
423: void
1.291 djm 424: ssh_userauth2(struct ssh *ssh, const char *local_user,
425: const char *server_user, char *host, Sensitive *sensitive)
1.20 markus 426: {
427: Authctxt authctxt;
1.231 markus 428: int r;
1.39 markus 429:
1.53 markus 430: if (options.preferred_authentications == NULL)
431: options.preferred_authentications = authmethods_get();
432:
1.20 markus 433: /* setup authentication context */
1.82 markus 434: memset(&authctxt, 0, sizeof(authctxt));
1.20 markus 435: authctxt.server_user = server_user;
1.68 markus 436: authctxt.local_user = local_user;
1.20 markus 437: authctxt.host = host;
438: authctxt.service = "ssh-connection"; /* service name */
439: authctxt.success = 0;
1.23 markus 440: authctxt.method = authmethod_lookup("none");
1.51 markus 441: authctxt.authlist = NULL;
1.121 markus 442: authctxt.methoddata = NULL;
1.100 markus 443: authctxt.sensitive = sensitive;
1.223 djm 444: authctxt.active_ktype = authctxt.oktypes = authctxt.ktypes = NULL;
1.82 markus 445: authctxt.info_req_seen = 0;
1.292 djm 446: authctxt.attempt_kbdint = 0;
447: authctxt.attempt_passwd = 0;
1.302 djm 448: #if GSSAPI
449: authctxt.gss_supported_mechs = NULL;
450: authctxt.mech_tried = 0;
451: #endif
1.215 djm 452: authctxt.agent_fd = -1;
1.352 djm 453: pubkey_prepare(ssh, &authctxt);
1.291 djm 454: if (authctxt.method == NULL) {
1.331 djm 455: fatal_f("internal error: cannot send userauth none request");
1.291 djm 456: }
1.20 markus 457:
1.231 markus 458: if ((r = sshpkt_start(ssh, SSH2_MSG_SERVICE_REQUEST)) != 0 ||
459: (r = sshpkt_put_cstring(ssh, "ssh-userauth")) != 0 ||
460: (r = sshpkt_send(ssh)) != 0)
1.331 djm 461: fatal_fr(r, "send packet");
1.231 markus 462:
1.260 markus 463: ssh->authctxt = &authctxt;
1.231 markus 464: ssh_dispatch_init(ssh, &input_userauth_error);
465: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
466: ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
1.263 markus 467: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
1.303 djm 468: pubkey_cleanup(ssh);
1.260 markus 469: ssh->authctxt = NULL;
1.20 markus 470:
1.231 markus 471: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL);
1.119 markus 472:
1.248 dtucker 473: if (!authctxt.success)
474: fatal("Authentication failed.");
1.351 djm 475: if (ssh_packet_connection_is_on_socket(ssh)) {
476: verbose("Authenticated to %s ([%s]:%d) using \"%s\".", host,
477: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
478: authctxt.method->name);
479: } else {
480: verbose("Authenticated to %s (via proxy) using \"%s\".", host,
481: authctxt.method->name);
482: }
1.20 markus 483: }
1.119 markus 484:
1.231 markus 485: /* ARGSUSED */
1.302 djm 486: static int
1.261 markus 487: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 488: {
489: int r;
490:
491: if (ssh_packet_remaining(ssh) > 0) {
492: char *reply;
493:
494: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
495: goto out;
496: debug2("service_accept: %s", reply);
497: free(reply);
498: } else {
499: debug2("buggy server: service_accept w/o service");
500: }
501: if ((r = sshpkt_get_end(ssh)) != 0)
502: goto out;
503: debug("SSH2_MSG_SERVICE_ACCEPT received");
504:
505: /* initial userauth request */
1.295 djm 506: userauth_none(ssh);
1.231 markus 507:
508: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
509: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
510: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
511: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
512: r = 0;
513: out:
514: return r;
515: }
516:
517: /* ARGSUSED */
1.302 djm 518: static int
1.261 markus 519: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 520: {
1.261 markus 521: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 522: }
523:
1.20 markus 524: void
1.295 djm 525: userauth(struct ssh *ssh, char *authlist)
1.51 markus 526: {
1.295 djm 527: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 528:
1.170 djm 529: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 530: authctxt->method->cleanup(ssh);
1.170 djm 531:
1.197 djm 532: free(authctxt->methoddata);
533: authctxt->methoddata = NULL;
1.51 markus 534: if (authlist == NULL) {
535: authlist = authctxt->authlist;
536: } else {
1.197 djm 537: free(authctxt->authlist);
1.51 markus 538: authctxt->authlist = authlist;
539: }
540: for (;;) {
541: Authmethod *method = authmethod_get(authlist);
542: if (method == NULL)
1.264 dtucker 543: fatal("%s@%s: Permission denied (%s).",
544: authctxt->server_user, authctxt->host, authlist);
1.51 markus 545: authctxt->method = method;
1.119 markus 546:
547: /* reset the per method handler */
1.278 markus 548: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 549: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
550:
551: /* and try new method */
1.295 djm 552: if (method->userauth(ssh) != 0) {
1.51 markus 553: debug2("we sent a %s packet, wait for reply", method->name);
554: break;
555: } else {
556: debug2("we did not send a packet, disable method");
557: method->enabled = NULL;
558: }
559: }
560: }
1.105 deraadt 561:
1.169 djm 562: /* ARGSUSED */
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:
1.169 djm 570: /* ARGSUSED */
1.302 djm 571: static int
1.261 markus 572: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 573: {
1.295 djm 574: char *msg = NULL;
1.294 djm 575: size_t len;
576: int r;
1.126 deraadt 577:
1.331 djm 578: debug3_f("entering");
1.294 djm 579: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 580: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 581: goto out;
1.246 djm 582: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
583: fmprintf(stderr, "%s", msg);
1.294 djm 584: r = 0;
585: out:
1.246 djm 586: free(msg);
1.294 djm 587: return r;
1.20 markus 588: }
1.105 deraadt 589:
1.169 djm 590: /* ARGSUSED */
1.302 djm 591: static int
1.261 markus 592: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 593: {
1.260 markus 594: Authctxt *authctxt = ssh->authctxt;
1.172 djm 595:
1.20 markus 596: if (authctxt == NULL)
1.331 djm 597: fatal_f("no authentication context");
1.197 djm 598: free(authctxt->authlist);
599: authctxt->authlist = NULL;
1.172 djm 600: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 601: authctxt->method->cleanup(ssh);
1.197 djm 602: free(authctxt->methoddata);
603: authctxt->methoddata = NULL;
1.20 markus 604: authctxt->success = 1; /* break out */
1.218 markus 605: return 0;
1.20 markus 606: }
1.105 deraadt 607:
1.302 djm 608: #if 0
609: static int
1.261 markus 610: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 611: {
1.260 markus 612: Authctxt *authctxt = ssh->authctxt;
1.172 djm 613:
614: if (authctxt == NULL)
1.331 djm 615: fatal_f("no authentication context");
1.172 djm 616:
617: fatal("Unexpected authentication success during %s.",
618: authctxt->method->name);
1.218 markus 619: return 0;
1.172 djm 620: }
1.302 djm 621: #endif
1.172 djm 622:
1.169 djm 623: /* ARGSUSED */
1.302 djm 624: static int
1.261 markus 625: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 626: {
1.260 markus 627: Authctxt *authctxt = ssh->authctxt;
1.20 markus 628: char *authlist = NULL;
1.278 markus 629: u_char partial;
1.20 markus 630:
631: if (authctxt == NULL)
632: fatal("input_userauth_failure: no authentication context");
633:
1.307 dtucker 634: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
635: sshpkt_get_u8(ssh, &partial) != 0 ||
636: sshpkt_get_end(ssh) != 0)
1.278 markus 637: goto out;
1.20 markus 638:
1.193 markus 639: if (partial != 0) {
1.351 djm 640: verbose("Authenticated using \"%s\" with partial success.",
641: authctxt->method->name);
1.193 markus 642: /* reset state */
1.251 djm 643: pubkey_reset(authctxt);
1.193 markus 644: }
1.109 markus 645: debug("Authentications that can continue: %s", authlist);
1.20 markus 646:
1.295 djm 647: userauth(ssh, authlist);
1.278 markus 648: authlist = NULL;
649: out:
650: free(authlist);
1.218 markus 651: return 0;
1.51 markus 652: }
1.169 djm 653:
1.287 djm 654: /*
655: * Format an identity for logging including filename, key type, fingerprint
656: * and location (agent, etc.). Caller must free.
657: */
658: static char *
659: format_identity(Identity *id)
660: {
661: char *fp = NULL, *ret = NULL;
1.309 djm 662: const char *note = "";
1.287 djm 663:
664: if (id->key != NULL) {
1.347 djm 665: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1.287 djm 666: SSH_FP_DEFAULT);
667: }
1.309 djm 668: if (id->key) {
669: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
670: note = " token";
1.311 markus 671: else if (sshkey_is_sk(id->key))
1.319 naddy 672: note = " authenticator";
1.309 djm 673: }
1.287 djm 674: xasprintf(&ret, "%s %s%s%s%s%s%s",
675: id->filename,
676: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
677: fp ? fp : "",
1.309 djm 678: id->userprovided ? " explicit" : "", note,
1.287 djm 679: id->agent_fd != -1 ? " agent" : "");
680: free(fp);
681: return ret;
682: }
683:
1.169 djm 684: /* ARGSUSED */
1.302 djm 685: static int
1.261 markus 686: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 687: {
1.260 markus 688: Authctxt *authctxt = ssh->authctxt;
1.259 markus 689: struct sshkey *key = NULL;
1.117 markus 690: Identity *id = NULL;
1.287 djm 691: int pktype, found = 0, sent = 0;
1.278 markus 692: size_t blen;
1.287 djm 693: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 694: u_char *pkblob = NULL;
695: int r;
1.51 markus 696:
697: if (authctxt == NULL)
698: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 699:
1.278 markus 700: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
701: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
702: (r = sshpkt_get_end(ssh)) != 0)
703: goto done;
1.51 markus 704:
1.278 markus 705: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 706: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 707: goto done;
708: }
1.278 markus 709: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 710: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 711: goto done;
712: }
713: if (key->type != pktype) {
714: error("input_userauth_pk_ok: type mismatch "
715: "for decoded key (received %d, expected %d)",
716: key->type, pktype);
717: goto done;
718: }
719:
1.127 markus 720: /*
721: * search keys in the reverse order, because last candidate has been
722: * moved to the end of the queue. this also avoids confusion by
723: * duplicate keys
724: */
1.136 henning 725: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 726: if (sshkey_equal(key, id->key)) {
1.287 djm 727: found = 1;
1.51 markus 728: break;
729: }
1.117 markus 730: }
1.287 djm 731: if (!found || id == NULL) {
732: fp = sshkey_fingerprint(key, options.fingerprint_hash,
733: SSH_FP_DEFAULT);
1.331 djm 734: error_f("server replied with unknown key: %s %s",
1.287 djm 735: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
736: goto done;
737: }
738: ident = format_identity(id);
739: debug("Server accepts key: %s", ident);
1.295 djm 740: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 741: r = 0;
742: done:
743: sshkey_free(key);
1.287 djm 744: free(ident);
745: free(fp);
1.197 djm 746: free(pkalg);
747: free(pkblob);
1.51 markus 748:
1.106 deraadt 749: /* try another method if we did not send a packet */
1.278 markus 750: if (r == 0 && sent == 0)
1.295 djm 751: userauth(ssh, NULL);
1.278 markus 752: return r;
1.20 markus 753: }
1.121 markus 754:
755: #ifdef GSSAPI
1.302 djm 756: static int
1.295 djm 757: userauth_gssapi(struct ssh *ssh)
1.121 markus 758: {
1.295 djm 759: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 760: Gssctxt *gssctxt = NULL;
761: OM_uint32 min;
1.278 markus 762: int r, ok = 0;
1.302 djm 763: gss_OID mech = NULL;
1.121 markus 764:
765: /* Try one GSSAPI method at a time, rather than sending them all at
766: * once. */
767:
1.302 djm 768: if (authctxt->gss_supported_mechs == NULL)
769: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 770:
1.302 djm 771: /* Check to see whether the mechanism is usable before we offer it */
772: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
773: !ok) {
774: mech = &authctxt->gss_supported_mechs->
775: elements[authctxt->mech_tried];
1.121 markus 776: /* My DER encoding requires length<128 */
1.302 djm 777: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
778: mech, authctxt->host)) {
1.121 markus 779: ok = 1; /* Mechanism works */
780: } else {
1.302 djm 781: authctxt->mech_tried++;
1.121 markus 782: }
783: }
784:
1.302 djm 785: if (!ok || mech == NULL)
1.139 djm 786: return 0;
1.121 markus 787:
788: authctxt->methoddata=(void *)gssctxt;
789:
1.278 markus 790: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
791: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
792: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
793: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
794: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 795: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 796: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 797: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
798: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 799: (r = sshpkt_send(ssh)) != 0)
1.331 djm 800: fatal_fr(r, "send packet");
1.278 markus 801:
802: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
803: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
804: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
805: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 806:
1.302 djm 807: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 808:
809: return 1;
810: }
811:
1.302 djm 812: static void
813: userauth_gssapi_cleanup(struct ssh *ssh)
814: {
815: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
816: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
817:
818: ssh_gssapi_delete_ctx(&gssctxt);
819: authctxt->methoddata = NULL;
820:
821: free(authctxt->gss_supported_mechs);
822: authctxt->gss_supported_mechs = NULL;
823: }
824:
1.130 markus 825: static OM_uint32
1.262 djm 826: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 827: {
1.260 markus 828: Authctxt *authctxt = ssh->authctxt;
1.130 markus 829: Gssctxt *gssctxt = authctxt->methoddata;
830: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 831: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
832: gss_buffer_desc gssbuf;
1.132 markus 833: OM_uint32 status, ms, flags;
1.278 markus 834: int r;
1.133 djm 835:
1.130 markus 836: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 837: recv_tok, &send_tok, &flags);
1.130 markus 838:
839: if (send_tok.length > 0) {
1.278 markus 840: u_char type = GSS_ERROR(status) ?
841: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
842: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
843:
844: if ((r = sshpkt_start(ssh, type)) != 0 ||
845: (r = sshpkt_put_string(ssh, send_tok.value,
846: send_tok.length)) != 0 ||
847: (r = sshpkt_send(ssh)) != 0)
1.331 djm 848: fatal_fr(r, "send %u packet", type);
1.133 djm 849:
1.130 markus 850: gss_release_buffer(&ms, &send_tok);
851: }
1.133 djm 852:
1.130 markus 853: if (status == GSS_S_COMPLETE) {
1.132 markus 854: /* send either complete or MIC, depending on mechanism */
855: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 856: if ((r = sshpkt_start(ssh,
857: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
858: (r = sshpkt_send(ssh)) != 0)
1.331 djm 859: fatal_fr(r, "send completion");
1.132 markus 860: } else {
1.278 markus 861: struct sshbuf *b;
862:
863: if ((b = sshbuf_new()) == NULL)
1.331 djm 864: fatal_f("sshbuf_new failed");
1.278 markus 865: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 djm 866: authctxt->service, "gssapi-with-mic",
867: ssh->kex->session_id);
1.132 markus 868:
1.278 markus 869: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 870: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 871: gssbuf.length = sshbuf_len(b);
1.133 djm 872:
1.132 markus 873: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 874:
1.132 markus 875: if (!GSS_ERROR(status)) {
1.278 markus 876: if ((r = sshpkt_start(ssh,
877: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
878: (r = sshpkt_put_string(ssh, mic.value,
879: mic.length)) != 0 ||
880: (r = sshpkt_send(ssh)) != 0)
1.331 djm 881: fatal_fr(r, "send MIC");
1.132 markus 882: }
1.133 djm 883:
1.278 markus 884: sshbuf_free(b);
1.132 markus 885: gss_release_buffer(&ms, &mic);
1.133 djm 886: }
1.130 markus 887: }
1.133 djm 888:
1.130 markus 889: return status;
890: }
891:
1.169 djm 892: /* ARGSUSED */
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:
1.169 djm 937: /* ARGSUSED */
1.302 djm 938: static int
1.261 markus 939: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 940: {
1.260 markus 941: Authctxt *authctxt = ssh->authctxt;
1.121 markus 942: gss_buffer_desc recv_tok;
1.278 markus 943: u_char *p = NULL;
944: size_t len;
1.130 markus 945: OM_uint32 status;
1.278 markus 946: int r;
1.121 markus 947:
948: if (authctxt == NULL)
949: fatal("input_gssapi_response: no authentication context");
950:
1.278 markus 951: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
952: (r = sshpkt_get_end(ssh)) != 0)
953: goto out;
1.121 markus 954:
1.278 markus 955: recv_tok.value = p;
956: recv_tok.length = len;
1.262 djm 957: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 958:
1.278 markus 959: /* Start again with the next method in the list */
1.121 markus 960: if (GSS_ERROR(status)) {
1.296 djm 961: userauth(ssh, NULL);
1.278 markus 962: /* ok */
1.121 markus 963: }
1.278 markus 964: r = 0;
965: out:
966: free(p);
967: return r;
1.121 markus 968: }
969:
1.169 djm 970: /* ARGSUSED */
1.302 djm 971: static int
1.261 markus 972: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 973: {
1.260 markus 974: Authctxt *authctxt = ssh->authctxt;
1.121 markus 975: Gssctxt *gssctxt;
976: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
977: gss_buffer_desc recv_tok;
1.194 djm 978: OM_uint32 ms;
1.278 markus 979: u_char *p = NULL;
980: size_t len;
981: int r;
1.121 markus 982:
983: if (authctxt == NULL)
984: fatal("input_gssapi_response: no authentication context");
985: gssctxt = authctxt->methoddata;
986:
1.278 markus 987: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
988: (r = sshpkt_get_end(ssh)) != 0) {
989: free(p);
990: return r;
991: }
1.121 markus 992:
993: /* Stick it into GSSAPI and see what it says */
1.278 markus 994: recv_tok.value = p;
995: recv_tok.length = len;
1.194 djm 996: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 997: &recv_tok, &send_tok, NULL);
1.278 markus 998: free(p);
1.121 markus 999: gss_release_buffer(&ms, &send_tok);
1000:
1001: /* Server will be returning a failed packet after this one */
1.220 djm 1002: return 0;
1.121 markus 1003: }
1004:
1.169 djm 1005: /* ARGSUSED */
1.302 djm 1006: static int
1.261 markus 1007: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 1008: {
1.278 markus 1009: char *msg = NULL;
1010: char *lang = NULL;
1011: int r;
1.121 markus 1012:
1.278 markus 1013: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1014: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1015: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1016: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1017: goto out;
1018: r = sshpkt_get_end(ssh);
1.143 stevesk 1019: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1020: out:
1.197 djm 1021: free(msg);
1022: free(lang);
1.278 markus 1023: return r;
1.121 markus 1024: }
1025: #endif /* GSSAPI */
1.20 markus 1026:
1.302 djm 1027: static int
1.295 djm 1028: userauth_none(struct ssh *ssh)
1.23 markus 1029: {
1.295 djm 1030: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1031: int r;
1032:
1.23 markus 1033: /* initial userauth request */
1.278 markus 1034: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1035: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1036: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1037: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1038: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1039: fatal_fr(r, "send packet");
1.23 markus 1040: return 1;
1041: }
1042:
1.302 djm 1043: static int
1.295 djm 1044: userauth_passwd(struct ssh *ssh)
1.1 markus 1045: {
1.295 djm 1046: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1047: char *password, *prompt = NULL;
1.175 dtucker 1048: const char *host = options.host_key_alias ? options.host_key_alias :
1049: authctxt->host;
1.278 markus 1050: int r;
1.6 markus 1051:
1.292 djm 1052: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1053: return 0;
1.13 todd 1054:
1.292 djm 1055: if (authctxt->attempt_passwd != 1)
1.13 todd 1056: error("Permission denied, please try again.");
1.1 markus 1057:
1.290 djm 1058: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1059: password = read_passphrase(prompt, 0);
1.278 markus 1060: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1061: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1062: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1063: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1064: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1065: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1066: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1067: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1068: fatal_fr(r, "send packet");
1.99 markus 1069:
1.290 djm 1070: free(prompt);
1071: if (password != NULL)
1.278 markus 1072: freezero(password, strlen(password));
1073:
1074: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1075: &input_userauth_passwd_changereq);
1076:
1.1 markus 1077: return 1;
1078: }
1.169 djm 1079:
1.99 markus 1080: /*
1081: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1082: */
1.169 djm 1083: /* ARGSUSED */
1.302 djm 1084: static int
1.261 markus 1085: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1086: {
1.260 markus 1087: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1088: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1089: char prompt[256];
1.252 djm 1090: const char *host;
1.278 markus 1091: int r;
1.99 markus 1092:
1093: debug2("input_userauth_passwd_changereq");
1094:
1095: if (authctxt == NULL)
1096: fatal("input_userauth_passwd_changereq: "
1097: "no authentication context");
1.252 djm 1098: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1099:
1.278 markus 1100: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1101: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1102: goto out;
1.99 markus 1103: if (strlen(info) > 0)
1.116 itojun 1104: logit("%s", info);
1.278 markus 1105: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1106: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1107: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1108: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1109: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1110: goto out;
1111:
1.104 deraadt 1112: snprintf(prompt, sizeof(prompt),
1.99 markus 1113: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1114: authctxt->server_user, host);
1.99 markus 1115: password = read_passphrase(prompt, 0);
1.278 markus 1116: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1117: goto out;
1118:
1119: freezero(password, strlen(password));
1.99 markus 1120: password = NULL;
1121: while (password == NULL) {
1.104 deraadt 1122: snprintf(prompt, sizeof(prompt),
1.99 markus 1123: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1124: authctxt->server_user, host);
1.99 markus 1125: password = read_passphrase(prompt, RP_ALLOW_EOF);
1126: if (password == NULL) {
1127: /* bail out */
1.278 markus 1128: r = 0;
1129: goto out;
1.99 markus 1130: }
1.104 deraadt 1131: snprintf(prompt, sizeof(prompt),
1.99 markus 1132: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1133: authctxt->server_user, host);
1.99 markus 1134: retype = read_passphrase(prompt, 0);
1135: if (strcmp(password, retype) != 0) {
1.278 markus 1136: freezero(password, strlen(password));
1.116 itojun 1137: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1138: password = NULL;
1139: }
1.278 markus 1140: freezero(retype, strlen(retype));
1.99 markus 1141: }
1.278 markus 1142: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1143: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1144: (r = sshpkt_send(ssh)) != 0)
1145: goto out;
1.104 deraadt 1146:
1.278 markus 1147: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1148: &input_userauth_passwd_changereq);
1.278 markus 1149: r = 0;
1150: out:
1151: if (password)
1152: freezero(password, strlen(password));
1153: free(info);
1154: free(lang);
1155: return r;
1.117 markus 1156: }
1157:
1.272 djm 1158: /*
1159: * Select an algorithm for publickey signatures.
1160: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1161: *
1162: * Call with ssh==NULL to ignore server-sig-algs extension list and
1163: * only attempt with the key's base signature type.
1164: */
1165: static char *
1166: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1167: {
1.274 djm 1168: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.348 djm 1169: const char *server_sig_algs;
1.231 markus 1170:
1.272 djm 1171: /*
1172: * The signature algorithm will only differ from the key algorithm
1173: * for RSA keys/certs and when the server advertises support for
1174: * newer (SHA2) algorithms.
1175: */
1176: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1177: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1178: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1179: /* Filter base key signature alg against our configuration */
1.279 markus 1180: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1181: options.pubkey_accepted_algos, NULL);
1.231 markus 1182: }
1183:
1.272 djm 1184: /*
1.348 djm 1185: * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1186: * fails to advertise it via SSH2_MSG_EXT_INFO.
1187: */
1188: server_sig_algs = ssh->kex->server_sig_algs;
1189: if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1190: server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1191:
1192: /*
1.272 djm 1193: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1194: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1195: * that also appears in the supported signature algorithms list from
1196: * the server.
1197: */
1.342 dtucker 1198: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1199: while ((cp = strsep(&allowed, ",")) != NULL) {
1200: if (sshkey_type_from_name(cp) != key->type)
1201: continue;
1.323 djm 1202: tmp = match_list(sshkey_sigalg_by_name(cp),
1.348 djm 1203: server_sig_algs, NULL);
1.274 djm 1204: if (tmp != NULL)
1205: alg = xstrdup(cp);
1206: free(tmp);
1.272 djm 1207: if (alg != NULL)
1208: break;
1.269 djm 1209: }
1.272 djm 1210: free(oallowed);
1211: return alg;
1.269 djm 1212: }
1213:
1.117 markus 1214: static int
1.214 djm 1215: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1216: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1217: {
1.309 djm 1218: struct sshkey *sign_key = NULL, *prv = NULL;
1.360 djm 1219: int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1220: struct notifier_ctx *notifier = NULL;
1.325 djm 1221: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1222:
1223: *sigp = NULL;
1224: *lenp = 0;
1.99 markus 1225:
1.272 djm 1226: /* The agent supports this key. */
1.269 djm 1227: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1228: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1229: data, datalen, alg, compat);
1.269 djm 1230: }
1.214 djm 1231:
1.117 markus 1232: /*
1.272 djm 1233: * We have already loaded the private key or the private key is
1234: * stored in external hardware.
1.117 markus 1235: */
1.255 djm 1236: if (id->key != NULL &&
1.272 djm 1237: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1238: sign_key = id->key;
1.360 djm 1239: is_agent = 1;
1.309 djm 1240: } else {
1241: /* Load the private key from the file. */
1242: if ((prv = load_identity_file(id)) == NULL)
1243: return SSH_ERR_KEY_NOT_FOUND;
1244: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1245: error_f("private key %s contents do not match public",
1.347 djm 1246: id->filename);
1.309 djm 1247: r = SSH_ERR_KEY_NOT_FOUND;
1248: goto out;
1249: }
1250: sign_key = prv;
1.360 djm 1251: }
1.341 djm 1252: retry_pin:
1.360 djm 1253: /* Prompt for touch for non-agent FIDO keys that request UP */
1254: if (!is_agent && sshkey_is_sk(sign_key) &&
1255: (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1256: /* XXX should batch mode just skip these? */
1257: if ((fp = sshkey_fingerprint(sign_key,
1258: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1259: fatal_f("fingerprint failed");
1260: notifier = notify_start(options.batch_mode,
1261: "Confirm user presence for key %s %s",
1262: sshkey_type(sign_key), fp);
1263: free(fp);
1.272 djm 1264: }
1.310 djm 1265: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1266: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1267: debug_fr(r, "sshkey_sign");
1.360 djm 1268: if (!retried && pin == NULL && !is_agent &&
1269: sshkey_is_sk(sign_key) &&
1.341 djm 1270: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1271: notify_complete(notifier, NULL);
1272: notifier = NULL;
1.360 djm 1273: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1274: sshkey_type(sign_key), id->filename);
1275: pin = read_passphrase(prompt, 0);
1.341 djm 1276: retried = 1;
1277: goto retry_pin;
1278: }
1.309 djm 1279: goto out;
1280: }
1.341 djm 1281:
1.309 djm 1282: /*
1283: * PKCS#11 tokens may not support all signature algorithms,
1284: * so check what we get back.
1285: */
1286: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1287: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1288: goto out;
1.265 djm 1289: }
1.309 djm 1290: /* success */
1291: r = 0;
1292: out:
1.325 djm 1293: free(prompt);
1294: if (pin != NULL)
1295: freezero(pin, strlen(pin));
1.341 djm 1296: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1297: sshkey_free(prv);
1.269 djm 1298: return r;
1.51 markus 1299: }
1300:
1.76 itojun 1301: static int
1.255 djm 1302: id_filename_matches(Identity *id, Identity *private_id)
1303: {
1.356 djm 1304: static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
1.255 djm 1305: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1306: size_t i, slen;
1307:
1308: if (strcmp(id->filename, private_id->filename) == 0)
1309: return 1;
1310: for (i = 0; suffixes[i]; i++) {
1311: slen = strlen(suffixes[i]);
1312: if (len > slen && plen == len - slen &&
1313: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1314: memcmp(id->filename, private_id->filename, plen) == 0)
1315: return 1;
1316: }
1317: return 0;
1318: }
1319:
1320: static int
1.295 djm 1321: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1322: {
1.295 djm 1323: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1324: struct sshbuf *b = NULL;
1325: Identity *private_id, *sign_id = NULL;
1326: u_char *signature = NULL;
1327: size_t slen = 0, skip = 0;
1328: int r, fallback_sigtype, sent = 0;
1329: char *alg = NULL, *fp = NULL;
1.353 djm 1330: const char *loc = "", *method = "publickey";
1.354 djm 1331: int hostbound = 0;
1.353 djm 1332:
1333: /* prefer host-bound pubkey signatures if supported by server */
1.354 djm 1334: if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
1335: (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
1336: hostbound = 1;
1.353 djm 1337: method = "publickey-hostbound-v00@openssh.com";
1.354 djm 1338: }
1.1 markus 1339:
1.222 djm 1340: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1341: SSH_FP_DEFAULT)) == NULL)
1342: return 0;
1.51 markus 1343:
1.354 djm 1344: debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
1.1 markus 1345:
1.227 djm 1346: /*
1347: * If the key is an certificate, try to find a matching private key
1348: * and use it to complete the signature.
1.241 djm 1349: * If no such private key exists, fall back to trying the certificate
1350: * key itself in case it has a private half already loaded.
1.272 djm 1351: * This will try to set sign_id to the private key that will perform
1352: * the signature.
1.227 djm 1353: */
1.272 djm 1354: if (sshkey_is_cert(id->key)) {
1.227 djm 1355: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1356: if (sshkey_equal_public(id->key, private_id->key) &&
1357: id->key->type != private_id->key->type) {
1.272 djm 1358: sign_id = private_id;
1.227 djm 1359: break;
1360: }
1361: }
1.255 djm 1362: /*
1363: * Exact key matches are preferred, but also allow
1364: * filename matches for non-PKCS#11/agent keys that
1365: * didn't load public keys. This supports the case
1366: * of keeping just a private key file and public
1367: * certificate on disk.
1368: */
1.272 djm 1369: if (sign_id == NULL &&
1370: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1371: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1372: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1373: if (private_id->key == NULL &&
1374: id_filename_matches(id, private_id)) {
1.272 djm 1375: sign_id = private_id;
1.255 djm 1376: break;
1377: }
1378: }
1379: }
1.272 djm 1380: if (sign_id != NULL) {
1.331 djm 1381: debug2_f("using private key \"%s\"%s for "
1.349 djm 1382: "certificate", sign_id->filename,
1383: sign_id->agent_fd != -1 ? " from agent" : "");
1.227 djm 1384: } else {
1.331 djm 1385: debug_f("no separate private key for certificate "
1386: "\"%s\"", id->filename);
1.227 djm 1387: }
1388: }
1389:
1.272 djm 1390: /*
1391: * If the above didn't select another identity to do the signing
1392: * then default to the one we started with.
1393: */
1394: if (sign_id == NULL)
1395: sign_id = id;
1396:
1397: /* assemble and sign data */
1398: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1399: free(alg);
1400: slen = 0;
1401: signature = NULL;
1402: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1403: id->key)) == NULL) {
1.331 djm 1404: error_f("no mutual signature supported");
1.272 djm 1405: goto out;
1406: }
1.331 djm 1407: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1408:
1409: sshbuf_free(b);
1410: if ((b = sshbuf_new()) == NULL)
1.331 djm 1411: fatal_f("sshbuf_new failed");
1.345 djm 1412: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 djm 1413: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1414: fatal_fr(r, "sshbuf_putb");
1.272 djm 1415: } else {
1.346 djm 1416: if ((r = sshbuf_put_stringb(b,
1417: ssh->kex->session_id)) != 0)
1418: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1419: }
1.278 markus 1420: skip = sshbuf_len(b);
1.272 djm 1421: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1422: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1423: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.353 djm 1424: (r = sshbuf_put_cstring(b, method)) != 0 ||
1.272 djm 1425: (r = sshbuf_put_u8(b, 1)) != 0 ||
1426: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1427: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1428: fatal_fr(r, "assemble signed data");
1.272 djm 1429: }
1.354 djm 1430: if (hostbound) {
1.353 djm 1431: if (ssh->kex->initial_hostkey == NULL) {
1432: fatal_f("internal error: initial hostkey "
1433: "not recorded");
1434: }
1435: if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
1436: fatal_fr(r, "assemble %s hostkey", method);
1437: }
1.272 djm 1438: /* generate signature */
1439: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1440: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1441: if (r == 0)
1442: break;
1443: else if (r == SSH_ERR_KEY_NOT_FOUND)
1444: goto out; /* soft failure */
1445: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1446: !fallback_sigtype) {
1447: if (sign_id->agent_fd != -1)
1448: loc = "agent ";
1449: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1450: loc = "token ";
1451: logit("%skey %s %s returned incorrect signature type",
1452: loc, sshkey_type(id->key), fp);
1453: continue;
1454: }
1.331 djm 1455: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1456: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1457: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1458: goto out;
1.17 markus 1459: }
1.272 djm 1460: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1461: fatal_f("no signature");
1.51 markus 1462:
1.1 markus 1463: /* append signature */
1.272 djm 1464: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1465: fatal_fr(r, "append signature");
1.1 markus 1466:
1.272 djm 1467: #ifdef DEBUG_PK
1468: sshbuf_dump(b, stderr);
1469: #endif
1.1 markus 1470: /* skip session id and packet type */
1.272 djm 1471: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1472: fatal_fr(r, "consume");
1.1 markus 1473:
1474: /* put remaining data from buffer into packet */
1.272 djm 1475: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1476: (r = sshpkt_putb(ssh, b)) != 0 ||
1477: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1478: fatal_fr(r, "enqueue request");
1.272 djm 1479:
1480: /* success */
1481: sent = 1;
1.17 markus 1482:
1.272 djm 1483: out:
1484: free(fp);
1485: free(alg);
1486: sshbuf_free(b);
1487: freezero(signature, slen);
1488: return sent;
1.16 markus 1489: }
1490:
1.76 itojun 1491: static int
1.295 djm 1492: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1493: {
1.295 djm 1494: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1495: u_char *blob = NULL;
1496: char *alg = NULL;
1.278 markus 1497: size_t bloblen;
1498: u_int have_sig = 0;
1499: int sent = 0, r;
1.20 markus 1500:
1.272 djm 1501: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1502: debug_f("no mutual signature algorithm");
1.272 djm 1503: goto out;
1504: }
1.16 markus 1505:
1.278 markus 1506: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1507: /* we cannot handle this key */
1.331 djm 1508: debug3_f("cannot handle key");
1.272 djm 1509: goto out;
1.16 markus 1510: }
1.51 markus 1511: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1512: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1513:
1.278 markus 1514: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1515: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1516: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1517: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1518: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1519: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1520: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1521: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1522: fatal_fr(r, "send packet");
1.272 djm 1523: sent = 1;
1.278 markus 1524:
1525: out:
1.272 djm 1526: free(alg);
1.197 djm 1527: free(blob);
1.272 djm 1528: return sent;
1.51 markus 1529: }
1530:
1.259 markus 1531: static struct sshkey *
1.229 jcs 1532: load_identity_file(Identity *id)
1.51 markus 1533: {
1.259 markus 1534: struct sshkey *private = NULL;
1.229 jcs 1535: char prompt[300], *passphrase, *comment;
1.308 dtucker 1536: int r, quit = 0, i;
1.52 markus 1537: struct stat st;
1.16 markus 1538:
1.306 deraadt 1539: if (stat(id->filename, &st) == -1) {
1.330 djm 1540: do_log2(id->userprovided ?
1541: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1542: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1543: return NULL;
1544: }
1.214 djm 1545: snprintf(prompt, sizeof prompt,
1.229 jcs 1546: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1547: for (i = 0; i <= options.number_of_password_prompts; i++) {
1548: if (i == 0)
1549: passphrase = "";
1550: else {
1.20 markus 1551: passphrase = read_passphrase(prompt, 0);
1.214 djm 1552: if (*passphrase == '\0') {
1.20 markus 1553: debug2("no passphrase given, try next key");
1.214 djm 1554: free(passphrase);
1555: break;
1556: }
1557: }
1.229 jcs 1558: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1559: passphrase, &private, &comment))) {
1.214 djm 1560: case 0:
1561: break;
1562: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1563: if (options.batch_mode) {
1564: quit = 1;
1565: break;
1566: }
1.215 djm 1567: if (i != 0)
1568: debug2("bad passphrase given, try again...");
1.214 djm 1569: break;
1570: case SSH_ERR_SYSTEM_ERROR:
1571: if (errno == ENOENT) {
1.331 djm 1572: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1573: quit = 1;
1.214 djm 1574: break;
1.20 markus 1575: }
1.214 djm 1576: /* FALLTHROUGH */
1577: default:
1.331 djm 1578: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1579: quit = 1;
1580: break;
1581: }
1.311 markus 1582: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1583: options.sk_provider == NULL) {
1.319 naddy 1584: debug("key \"%s\" is an authenticator-hosted key, "
1585: "but no provider specified", id->filename);
1.309 djm 1586: sshkey_free(private);
1587: private = NULL;
1588: quit = 1;
1589: }
1.361 djm 1590: if (!quit && (r = sshkey_check_rsa_length(private,
1591: options.required_rsa_size)) != 0) {
1592: debug_fr(r, "Skipping key %s", id->filename);
1593: sshkey_free(private);
1594: private = NULL;
1595: quit = 1;
1596: }
1.230 djm 1597: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1598: !(id->key && id->isprivate))
1599: maybe_add_key_to_agent(id->filename, private, comment,
1600: passphrase);
1.278 markus 1601: if (i > 0)
1602: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1603: free(comment);
1.214 djm 1604: if (private != NULL || quit)
1605: break;
1.16 markus 1606: }
1.51 markus 1607: return private;
1608: }
1609:
1.272 djm 1610: static int
1611: key_type_allowed_by_config(struct sshkey *key)
1612: {
1613: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1614: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1615: return 1;
1616:
1617: /* RSA keys/certs might be allowed by alternate signature types */
1618: switch (key->type) {
1619: case KEY_RSA:
1620: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1621: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1622: return 1;
1623: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1624: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1625: return 1;
1626: break;
1627: case KEY_RSA_CERT:
1628: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1629: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1630: return 1;
1631: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1632: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1633: return 1;
1634: break;
1635: }
1636: return 0;
1637: }
1638:
1.352 djm 1639: /* obtain a list of keys from the agent */
1640: static int
1641: get_agent_identities(struct ssh *ssh, int *agent_fdp,
1642: struct ssh_identitylist **idlistp)
1643: {
1644: int r, agent_fd;
1645: struct ssh_identitylist *idlist;
1646:
1647: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1648: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1649: debug_fr(r, "ssh_get_authentication_socket");
1650: return r;
1651: }
1652: if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
1653: ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
1654: debug_f("bound agent to hostkey");
1655: else
1656: debug2_fr(r, "ssh_agent_bind_hostkey");
1657:
1658: if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1659: debug_fr(r, "ssh_fetch_identitylist");
1660: close(agent_fd);
1661: return r;
1662: }
1663: /* success */
1664: *agent_fdp = agent_fd;
1665: *idlistp = idlist;
1666: debug_f("agent returned %zu keys", idlist->nkeys);
1667: return 0;
1668: }
1.272 djm 1669:
1.117 markus 1670: /*
1671: * try keys in the following order:
1.332 djm 1672: * 1. certificates listed in the config file
1673: * 2. other input certificates
1.227 djm 1674: * 3. agent keys that are found in the config file
1675: * 4. other agent keys
1676: * 5. keys that are only listed in the config file
1.117 markus 1677: */
1678: static void
1.352 djm 1679: pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
1.51 markus 1680: {
1.214 djm 1681: struct identity *id, *id2, *tmp;
1682: struct idlist agent, files, *preferred;
1683: struct sshkey *key;
1.230 djm 1684: int agent_fd = -1, i, r, found;
1.214 djm 1685: size_t j;
1686: struct ssh_identitylist *idlist;
1.287 djm 1687: char *ident;
1.51 markus 1688:
1.117 markus 1689: TAILQ_INIT(&agent); /* keys from the agent */
1690: TAILQ_INIT(&files); /* keys from the config file */
1691: preferred = &authctxt->keys;
1692: TAILQ_INIT(preferred); /* preferred order of keys */
1693:
1.190 djm 1694: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1695: for (i = 0; i < options.num_identity_files; i++) {
1696: key = options.identity_keys[i];
1.309 djm 1697: if (key && key->cert &&
1698: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1699: debug_f("ignoring certificate %s: not a user "
1700: "certificate", options.identity_files[i]);
1.309 djm 1701: continue;
1702: }
1.311 markus 1703: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1704: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1705: "SecurityKeyProvider has been specified",
1.331 djm 1706: options.identity_files[i]);
1.117 markus 1707: continue;
1.309 djm 1708: }
1.117 markus 1709: options.identity_keys[i] = NULL;
1.150 djm 1710: id = xcalloc(1, sizeof(*id));
1.230 djm 1711: id->agent_fd = -1;
1.117 markus 1712: id->key = key;
1713: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1714: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1715: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1716: }
1.227 djm 1717: /* list of certificates specified by user */
1718: for (i = 0; i < options.num_certificate_files; i++) {
1719: key = options.certificates[i];
1.278 markus 1720: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1721: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1722: debug_f("ignoring certificate %s: not a user "
1723: "certificate", options.identity_files[i]);
1.227 djm 1724: continue;
1.309 djm 1725: }
1.311 markus 1726: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1727: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1728: "certificate %s as no "
1.309 djm 1729: "SecurityKeyProvider has been specified",
1.331 djm 1730: options.identity_files[i]);
1.309 djm 1731: continue;
1732: }
1.227 djm 1733: id = xcalloc(1, sizeof(*id));
1.230 djm 1734: id->agent_fd = -1;
1.227 djm 1735: id->key = key;
1736: id->filename = xstrdup(options.certificate_files[i]);
1737: id->userprovided = options.certificate_file_userprovided[i];
1738: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1739: }
1740: /* list of keys supported by the agent */
1.352 djm 1741: if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
1.214 djm 1742: for (j = 0; j < idlist->nkeys; j++) {
1.361 djm 1743: if ((r = sshkey_check_rsa_length(idlist->keys[j],
1744: options.required_rsa_size)) != 0) {
1745: debug_fr(r, "ignoring %s agent key",
1746: sshkey_ssh_name(idlist->keys[j]));
1747: continue;
1748: }
1.117 markus 1749: found = 0;
1750: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1751: /*
1752: * agent keys from the config file are
1753: * preferred
1754: */
1755: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1756: TAILQ_REMOVE(&files, id, next);
1757: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1758: id->agent_fd = agent_fd;
1.117 markus 1759: found = 1;
1760: break;
1761: }
1762: }
1.135 markus 1763: if (!found && !options.identities_only) {
1.150 djm 1764: id = xcalloc(1, sizeof(*id));
1.214 djm 1765: /* XXX "steals" key/comment from idlist */
1766: id->key = idlist->keys[j];
1767: id->filename = idlist->comments[j];
1768: idlist->keys[j] = NULL;
1769: idlist->comments[j] = NULL;
1770: id->agent_fd = agent_fd;
1.117 markus 1771: TAILQ_INSERT_TAIL(&agent, id, next);
1772: }
1773: }
1.214 djm 1774: ssh_free_identitylist(idlist);
1.117 markus 1775: /* append remaining agent keys */
1.324 bket 1776: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1777: authctxt->agent_fd = agent_fd;
1.244 djm 1778: }
1779: /* Prefer PKCS11 keys that are explicitly listed */
1780: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1781: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1782: continue;
1783: found = 0;
1784: TAILQ_FOREACH(id2, &files, next) {
1785: if (id2->key == NULL ||
1.321 djm 1786: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1787: continue;
1788: if (sshkey_equal(id->key, id2->key)) {
1789: TAILQ_REMOVE(&files, id, next);
1790: TAILQ_INSERT_TAIL(preferred, id, next);
1791: found = 1;
1792: break;
1793: }
1794: }
1795: /* If IdentitiesOnly set and key not found then don't use it */
1796: if (!found && options.identities_only) {
1797: TAILQ_REMOVE(&files, id, next);
1.278 markus 1798: freezero(id, sizeof(*id));
1.244 djm 1799: }
1.117 markus 1800: }
1801: /* append remaining keys from the config file */
1.324 bket 1802: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1803: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1804: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1805: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1806: debug("Skipping %s key %s - "
1.342 dtucker 1807: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1808: sshkey_ssh_name(id->key), id->filename);
1809: TAILQ_REMOVE(preferred, id, next);
1810: sshkey_free(id->key);
1811: free(id->filename);
1812: memset(id, 0, sizeof(*id));
1813: continue;
1814: }
1.117 markus 1815: }
1.287 djm 1816: /* List the keys we plan on using */
1817: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1818: ident = format_identity(id);
1819: debug("Will attempt key: %s", ident);
1820: free(ident);
1821: }
1.331 djm 1822: debug2_f("done");
1.17 markus 1823: }
1824:
1.117 markus 1825: static void
1.303 djm 1826: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1827: {
1.302 djm 1828: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1829: Identity *id;
1.51 markus 1830:
1.289 djm 1831: if (authctxt->agent_fd != -1) {
1.214 djm 1832: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1833: authctxt->agent_fd = -1;
1834: }
1.117 markus 1835: for (id = TAILQ_FIRST(&authctxt->keys); id;
1836: id = TAILQ_FIRST(&authctxt->keys)) {
1837: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1838: sshkey_free(id->key);
1.197 djm 1839: free(id->filename);
1840: free(id);
1.117 markus 1841: }
1.1 markus 1842: }
1843:
1.251 djm 1844: static void
1845: pubkey_reset(Authctxt *authctxt)
1846: {
1847: Identity *id;
1848:
1849: TAILQ_FOREACH(id, &authctxt->keys, next)
1850: id->tried = 0;
1851: }
1852:
1.225 markus 1853: static int
1.295 djm 1854: userauth_pubkey(struct ssh *ssh)
1.20 markus 1855: {
1.295 djm 1856: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1857: Identity *id;
1.20 markus 1858: int sent = 0;
1.287 djm 1859: char *ident;
1.20 markus 1860:
1.117 markus 1861: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1862: if (id->tried++)
1863: return (0);
1.127 markus 1864: /* move key to the end of the queue */
1.117 markus 1865: TAILQ_REMOVE(&authctxt->keys, id, next);
1866: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1867: /*
1868: * send a test message if we have the public key. for
1869: * encrypted keys we cannot do this and have to load the
1870: * private key instead
1871: */
1.200 djm 1872: if (id->key != NULL) {
1.362 dtucker 1873: if (id->key != NULL) {
1.287 djm 1874: ident = format_identity(id);
1875: debug("Offering public key: %s", ident);
1876: free(ident);
1.295 djm 1877: sent = send_pubkey_test(ssh, id);
1.200 djm 1878: }
1879: } else {
1.117 markus 1880: debug("Trying private key: %s", id->filename);
1.229 jcs 1881: id->key = load_identity_file(id);
1.117 markus 1882: if (id->key != NULL) {
1.362 dtucker 1883: if (id->key != NULL) {
1.225 markus 1884: id->isprivate = 1;
1.295 djm 1885: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1886: }
1.278 markus 1887: sshkey_free(id->key);
1.117 markus 1888: id->key = NULL;
1.251 djm 1889: id->isprivate = 0;
1.51 markus 1890: }
1891: }
1.117 markus 1892: if (sent)
1893: return (sent);
1.28 markus 1894: }
1.117 markus 1895: return (0);
1.20 markus 1896: }
1897:
1.23 markus 1898: /*
1899: * Send userauth request message specifying keyboard-interactive method.
1900: */
1.302 djm 1901: static int
1.295 djm 1902: userauth_kbdint(struct ssh *ssh)
1.23 markus 1903: {
1.295 djm 1904: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1905: int r;
1.23 markus 1906:
1.292 djm 1907: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1908: return 0;
1.82 markus 1909: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1910: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1911: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1912: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1913: return 0;
1914: }
1.23 markus 1915:
1916: debug2("userauth_kbdint");
1.278 markus 1917: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1918: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1919: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1920: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1921: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1922: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1923: options.kbd_interactive_devices : "")) != 0 ||
1924: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1925: fatal_fr(r, "send packet");
1.23 markus 1926:
1.278 markus 1927: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1928: return 1;
1929: }
1930:
1931: /*
1.46 markus 1932: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1933: */
1.302 djm 1934: static int
1.261 markus 1935: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1936: {
1.260 markus 1937: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1938: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1939: char *display_prompt = NULL, *response = NULL;
1.278 markus 1940: u_char echo = 0;
1.32 markus 1941: u_int num_prompts, i;
1.278 markus 1942: int r;
1.23 markus 1943:
1.335 djm 1944: debug2_f("entering");
1.23 markus 1945:
1946: if (authctxt == NULL)
1.335 djm 1947: fatal_f("no authentication context");
1.82 markus 1948:
1949: authctxt->info_req_seen = 1;
1.23 markus 1950:
1.278 markus 1951: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1952: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1953: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1954: goto out;
1.23 markus 1955: if (strlen(name) > 0)
1.116 itojun 1956: logit("%s", name);
1.23 markus 1957: if (strlen(inst) > 0)
1.116 itojun 1958: logit("%s", inst);
1.23 markus 1959:
1.278 markus 1960: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1961: goto out;
1.23 markus 1962: /*
1963: * Begin to build info response packet based on prompts requested.
1964: * We commit to providing the correct number of responses, so if
1965: * further on we run into a problem that prevents this, we have to
1966: * be sure and clean this up and send a correct error response.
1967: */
1.278 markus 1968: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1969: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1970: goto out;
1.23 markus 1971:
1.335 djm 1972: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1973: for (i = 0; i < num_prompts; i++) {
1.278 markus 1974: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1975: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1976: goto out;
1.336 djm 1977: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1978: authctxt->server_user, options.host_key_alias ?
1.336 djm 1979: options.host_key_alias : authctxt->host, prompt) == -1)
1980: fatal_f("asmprintf failed");
1.335 djm 1981: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1982: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1983: goto out;
1984: freezero(response, strlen(response));
1.197 djm 1985: free(prompt);
1.335 djm 1986: free(display_prompt);
1987: display_prompt = response = prompt = NULL;
1.23 markus 1988: }
1.278 markus 1989: /* done with parsing incoming message. */
1990: if ((r = sshpkt_get_end(ssh)) != 0 ||
1991: (r = sshpkt_add_padding(ssh, 64)) != 0)
1992: goto out;
1993: r = sshpkt_send(ssh);
1994: out:
1995: if (response)
1996: freezero(response, strlen(response));
1997: free(prompt);
1.335 djm 1998: free(display_prompt);
1.278 markus 1999: free(name);
2000: free(inst);
2001: free(lang);
2002: return r;
1.68 markus 2003: }
2004:
1.100 markus 2005: static int
1.294 djm 2006: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 2007: const u_char *data, size_t datalen)
1.100 markus 2008: {
1.223 djm 2009: struct sshbuf *b;
1.101 markus 2010: struct stat st;
1.100 markus 2011: pid_t pid;
1.304 deraadt 2012: int r, to[2], from[2], status;
1.295 djm 2013: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 2014: u_char rversion = 0, version = 2;
2015: void (*osigchld)(int);
1.100 markus 2016:
1.223 djm 2017: *sigp = NULL;
2018: *lenp = 0;
1.100 markus 2019:
1.306 deraadt 2020: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 2021: error_f("not installed: %s", strerror(errno));
1.223 djm 2022: return -1;
2023: }
2024: if (fflush(stdout) != 0) {
1.331 djm 2025: error_f("fflush: %s", strerror(errno));
1.101 markus 2026: return -1;
2027: }
1.306 deraadt 2028: if (pipe(to) == -1) {
1.331 djm 2029: error_f("pipe: %s", strerror(errno));
1.100 markus 2030: return -1;
2031: }
1.306 deraadt 2032: if (pipe(from) == -1) {
1.331 djm 2033: error_f("pipe: %s", strerror(errno));
1.100 markus 2034: return -1;
2035: }
1.306 deraadt 2036: if ((pid = fork()) == -1) {
1.331 djm 2037: error_f("fork: %s", strerror(errno));
1.100 markus 2038: return -1;
2039: }
1.317 dtucker 2040: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 2041: if (pid == 0) {
2042: close(from[0]);
1.306 deraadt 2043: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2044: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2045: close(to[1]);
1.306 deraadt 2046: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2047: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2048: close(from[1]);
2049: close(to[0]);
1.304 deraadt 2050:
1.306 deraadt 2051: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2052: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2053: sock = STDERR_FILENO + 1;
1.363 dtucker 2054: if (fcntl(sock, F_SETFD, 0) == -1) /* keep the socket on exec */
2055: debug3_f("fcntl F_SETFD: %s", strerror(errno));
1.223 djm 2056: closefrom(sock + 1);
1.304 deraadt 2057:
1.331 djm 2058: debug3_f("[child] pid=%ld, exec %s",
2059: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2060: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2061: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2062: strerror(errno));
2063: }
2064: close(from[1]);
2065: close(to[0]);
1.305 djm 2066: sock = STDERR_FILENO + 1;
1.100 markus 2067:
1.223 djm 2068: if ((b = sshbuf_new()) == NULL)
1.331 djm 2069: fatal_f("sshbuf_new failed");
1.223 djm 2070: /* send # of sock, data to be signed */
1.253 djm 2071: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2072: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2073: fatal_fr(r, "buffer error");
1.223 djm 2074: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2075: fatal_f("couldn't send request");
1.223 djm 2076: sshbuf_reset(b);
2077: r = ssh_msg_recv(from[0], b);
1.101 markus 2078: close(from[0]);
2079: close(to[1]);
1.223 djm 2080: if (r < 0) {
1.331 djm 2081: error_f("no reply");
1.223 djm 2082: goto fail;
2083: }
1.101 markus 2084:
1.223 djm 2085: errno = 0;
1.306 deraadt 2086: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2087: if (errno != EINTR) {
1.331 djm 2088: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2089: goto fail;
2090: }
2091: }
2092: if (!WIFEXITED(status)) {
1.331 djm 2093: error_f("exited abnormally");
1.223 djm 2094: goto fail;
2095: }
2096: if (WEXITSTATUS(status) != 0) {
1.331 djm 2097: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2098: goto fail;
2099: }
2100: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2101: error_fr(r, "buffer error");
1.223 djm 2102: goto fail;
2103: }
2104: if (rversion != version) {
1.331 djm 2105: error_f("bad version");
1.223 djm 2106: goto fail;
2107: }
2108: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2109: error_fr(r, "buffer error");
1.223 djm 2110: fail:
1.317 dtucker 2111: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2112: sshbuf_free(b);
1.100 markus 2113: return -1;
2114: }
1.317 dtucker 2115: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2116: sshbuf_free(b);
1.100 markus 2117:
2118: return 0;
2119: }
2120:
1.302 djm 2121: static int
1.295 djm 2122: userauth_hostbased(struct ssh *ssh)
1.68 markus 2123: {
1.295 djm 2124: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2125: struct sshkey *private = NULL;
2126: struct sshbuf *b = NULL;
2127: u_char *sig = NULL, *keyblob = NULL;
2128: char *fp = NULL, *chost = NULL, *lname = NULL;
2129: size_t siglen = 0, keylen = 0;
2130: int i, r, success = 0;
2131:
2132: if (authctxt->ktypes == NULL) {
1.344 dtucker 2133: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2134: authctxt->ktypes = authctxt->oktypes;
2135: }
1.213 djm 2136:
1.223 djm 2137: /*
1.344 dtucker 2138: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2139: * trying each hostkey that matches the type in turn.
2140: */
2141: for (;;) {
2142: if (authctxt->active_ktype == NULL)
2143: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2144: if (authctxt->active_ktype == NULL ||
2145: *authctxt->active_ktype == '\0')
2146: break;
1.331 djm 2147: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2148:
1.223 djm 2149: /* check for a useful key */
2150: private = NULL;
2151: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2152: if (authctxt->sensitive->keys[i] == NULL ||
2153: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2154: continue;
1.355 djm 2155: if (!sshkey_match_keyname_to_sigalgs(
1.223 djm 2156: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.355 djm 2157: authctxt->active_ktype))
1.223 djm 2158: continue;
1.68 markus 2159: /* we take and free the key */
1.223 djm 2160: private = authctxt->sensitive->keys[i];
2161: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2162: break;
2163: }
1.223 djm 2164: /* Found one */
2165: if (private != NULL)
2166: break;
2167: /* No more keys of this type; advance */
2168: authctxt->active_ktype = NULL;
1.68 markus 2169: }
1.223 djm 2170: if (private == NULL) {
2171: free(authctxt->oktypes);
2172: authctxt->oktypes = authctxt->ktypes = NULL;
2173: authctxt->active_ktype = NULL;
1.109 markus 2174: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2175: goto out;
1.68 markus 2176: }
1.211 djm 2177:
1.223 djm 2178: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2179: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2180: error_f("sshkey_fingerprint failed");
1.223 djm 2181: goto out;
1.68 markus 2182: }
1.355 djm 2183: debug_f("trying hostkey %s %s using sigalg %s",
2184: sshkey_ssh_name(private), fp, authctxt->active_ktype);
1.211 djm 2185:
1.84 markus 2186: /* figure out a name for the client host */
1.295 djm 2187: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2188: if (lname == NULL) {
1.331 djm 2189: error_f("cannot get local ipaddr/name");
1.223 djm 2190: goto out;
1.84 markus 2191: }
1.223 djm 2192:
2193: /* XXX sshbuf_put_stringf? */
2194: xasprintf(&chost, "%s.", lname);
1.331 djm 2195: debug2_f("chost %s", chost);
1.84 markus 2196:
1.68 markus 2197: /* construct data */
1.223 djm 2198: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2199: error_f("sshbuf_new failed");
1.223 djm 2200: goto out;
2201: }
2202: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2203: error_fr(r, "sshkey_to_blob");
1.223 djm 2204: goto out;
2205: }
1.346 djm 2206: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2207: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2208: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2209: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2210: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2211: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2212: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2213: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2214: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2215: error_fr(r, "buffer error");
1.223 djm 2216: goto out;
2217: }
2218:
1.68 markus 2219: #ifdef DEBUG_PK
1.223 djm 2220: sshbuf_dump(b, stderr);
1.68 markus 2221: #endif
1.294 djm 2222: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2223: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2224: error("sign using hostkey %s %s failed",
2225: sshkey_ssh_name(private), fp);
2226: goto out;
2227: }
2228: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2229: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2230: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2231: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2232: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2233: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2234: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2235: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2236: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2237: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2238: error_fr(r, "packet error");
1.223 djm 2239: goto out;
2240: }
2241: success = 1;
2242:
2243: out:
1.278 markus 2244: if (sig != NULL)
2245: freezero(sig, siglen);
1.223 djm 2246: free(keyblob);
2247: free(lname);
2248: free(fp);
1.197 djm 2249: free(chost);
1.223 djm 2250: sshkey_free(private);
2251: sshbuf_free(b);
1.68 markus 2252:
1.223 djm 2253: return success;
1.23 markus 2254: }
1.170 djm 2255:
1.20 markus 2256: /* find auth method */
2257:
2258: /*
2259: * given auth method name, if configurable options permit this method fill
2260: * in auth_ident field and return true, otherwise return false.
2261: */
1.76 itojun 2262: static int
1.20 markus 2263: authmethod_is_enabled(Authmethod *method)
2264: {
2265: if (method == NULL)
2266: return 0;
2267: /* return false if options indicate this method is disabled */
2268: if (method->enabled == NULL || *method->enabled == 0)
2269: return 0;
2270: /* return false if batch mode is enabled but method needs interactive mode */
2271: if (method->batch_flag != NULL && *method->batch_flag != 0)
2272: return 0;
2273: return 1;
2274: }
2275:
1.76 itojun 2276: static Authmethod *
1.20 markus 2277: authmethod_lookup(const char *name)
1.1 markus 2278: {
1.20 markus 2279: Authmethod *method = NULL;
2280: if (name != NULL)
2281: for (method = authmethods; method->name != NULL; method++)
2282: if (strcmp(name, method->name) == 0)
2283: return method;
2284: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2285: return NULL;
2286: }
1.1 markus 2287:
1.53 markus 2288: /* XXX internal state */
2289: static Authmethod *current = NULL;
2290: static char *supported = NULL;
2291: static char *preferred = NULL;
1.105 deraadt 2292:
1.20 markus 2293: /*
2294: * Given the authentication method list sent by the server, return the
2295: * next method we should try. If the server initially sends a nil list,
1.67 markus 2296: * use a built-in default list.
1.41 stevesk 2297: */
1.76 itojun 2298: static Authmethod *
1.20 markus 2299: authmethod_get(char *authlist)
2300: {
1.53 markus 2301: char *name = NULL;
1.97 markus 2302: u_int next;
1.41 stevesk 2303:
1.20 markus 2304: /* Use a suitable default if we're passed a nil list. */
2305: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2306: authlist = options.preferred_authentications;
1.20 markus 2307:
1.53 markus 2308: if (supported == NULL || strcmp(authlist, supported) != 0) {
2309: debug3("start over, passed a different list %s", authlist);
1.197 djm 2310: free(supported);
1.53 markus 2311: supported = xstrdup(authlist);
2312: preferred = options.preferred_authentications;
2313: debug3("preferred %s", preferred);
2314: current = NULL;
2315: } else if (current != NULL && authmethod_is_enabled(current))
2316: return current;
1.20 markus 2317:
1.53 markus 2318: for (;;) {
2319: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2320: debug("No more authentication methods to try.");
1.53 markus 2321: current = NULL;
2322: return NULL;
2323: }
2324: preferred += next;
1.23 markus 2325: debug3("authmethod_lookup %s", name);
1.53 markus 2326: debug3("remaining preferred: %s", preferred);
2327: if ((current = authmethod_lookup(name)) != NULL &&
2328: authmethod_is_enabled(current)) {
1.23 markus 2329: debug3("authmethod_is_enabled %s", name);
1.109 markus 2330: debug("Next authentication method: %s", name);
1.197 djm 2331: free(name);
1.53 markus 2332: return current;
1.23 markus 2333: }
1.198 dtucker 2334: free(name);
1.1 markus 2335: }
1.53 markus 2336: }
1.1 markus 2337:
1.79 stevesk 2338: static char *
1.53 markus 2339: authmethods_get(void)
2340: {
2341: Authmethod *method = NULL;
1.278 markus 2342: struct sshbuf *b;
1.93 markus 2343: char *list;
1.278 markus 2344: int r;
1.27 provos 2345:
1.278 markus 2346: if ((b = sshbuf_new()) == NULL)
1.331 djm 2347: fatal_f("sshbuf_new failed");
1.53 markus 2348: for (method = authmethods; method->name != NULL; method++) {
2349: if (authmethod_is_enabled(method)) {
1.278 markus 2350: if ((r = sshbuf_putf(b, "%s%s",
2351: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2352: fatal_fr(r, "buffer error");
1.53 markus 2353: }
2354: }
1.278 markus 2355: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2356: fatal_f("sshbuf_dup_string failed");
1.278 markus 2357: sshbuf_free(b);
1.93 markus 2358: return list;
1.1 markus 2359: }
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