Annotation of src/usr.bin/ssh/sshconnect2.c, Revision 1.365
1.365 ! guenther 1: /* $OpenBSD: sshconnect2.c,v 1.364 2023/03/06 12:14:48 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:
1.302 djm 485: static int
1.261 markus 486: input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
1.231 markus 487: {
488: int r;
489:
490: if (ssh_packet_remaining(ssh) > 0) {
491: char *reply;
492:
493: if ((r = sshpkt_get_cstring(ssh, &reply, NULL)) != 0)
494: goto out;
495: debug2("service_accept: %s", reply);
496: free(reply);
497: } else {
498: debug2("buggy server: service_accept w/o service");
499: }
500: if ((r = sshpkt_get_end(ssh)) != 0)
501: goto out;
502: debug("SSH2_MSG_SERVICE_ACCEPT received");
503:
504: /* initial userauth request */
1.295 djm 505: userauth_none(ssh);
1.231 markus 506:
507: ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_error);
508: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success);
509: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure);
510: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner);
511: r = 0;
512: out:
513: return r;
514: }
515:
1.302 djm 516: static int
1.261 markus 517: input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
1.231 markus 518: {
1.261 markus 519: return kex_input_ext_info(type, seqnr, ssh);
1.231 markus 520: }
521:
1.20 markus 522: void
1.295 djm 523: userauth(struct ssh *ssh, char *authlist)
1.51 markus 524: {
1.295 djm 525: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 526:
1.170 djm 527: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 528: authctxt->method->cleanup(ssh);
1.170 djm 529:
1.197 djm 530: free(authctxt->methoddata);
531: authctxt->methoddata = NULL;
1.51 markus 532: if (authlist == NULL) {
533: authlist = authctxt->authlist;
534: } else {
1.197 djm 535: free(authctxt->authlist);
1.51 markus 536: authctxt->authlist = authlist;
537: }
538: for (;;) {
539: Authmethod *method = authmethod_get(authlist);
540: if (method == NULL)
1.264 dtucker 541: fatal("%s@%s: Permission denied (%s).",
542: authctxt->server_user, authctxt->host, authlist);
1.51 markus 543: authctxt->method = method;
1.119 markus 544:
545: /* reset the per method handler */
1.278 markus 546: ssh_dispatch_range(ssh, SSH2_MSG_USERAUTH_PER_METHOD_MIN,
1.119 markus 547: SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL);
548:
549: /* and try new method */
1.295 djm 550: if (method->userauth(ssh) != 0) {
1.51 markus 551: debug2("we sent a %s packet, wait for reply", method->name);
552: break;
553: } else {
554: debug2("we did not send a packet, disable method");
555: method->enabled = NULL;
556: }
557: }
558: }
1.105 deraadt 559:
1.302 djm 560: static int
1.261 markus 561: input_userauth_error(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 562: {
1.331 djm 563: fatal_f("bad message during authentication: type %d", type);
1.218 markus 564: return 0;
1.35 markus 565: }
1.105 deraadt 566:
1.302 djm 567: static int
1.261 markus 568: input_userauth_banner(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 569: {
1.295 djm 570: char *msg = NULL;
1.294 djm 571: size_t len;
572: int r;
1.126 deraadt 573:
1.331 djm 574: debug3_f("entering");
1.294 djm 575: if ((r = sshpkt_get_cstring(ssh, &msg, &len)) != 0 ||
1.295 djm 576: (r = sshpkt_get_cstring(ssh, NULL, NULL)) != 0)
1.294 djm 577: goto out;
1.246 djm 578: if (len > 0 && options.log_level >= SYSLOG_LEVEL_INFO)
579: fmprintf(stderr, "%s", msg);
1.294 djm 580: r = 0;
581: out:
1.246 djm 582: free(msg);
1.294 djm 583: return r;
1.20 markus 584: }
1.105 deraadt 585:
1.302 djm 586: static int
1.261 markus 587: input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 588: {
1.260 markus 589: Authctxt *authctxt = ssh->authctxt;
1.172 djm 590:
1.20 markus 591: if (authctxt == NULL)
1.331 djm 592: fatal_f("no authentication context");
1.197 djm 593: free(authctxt->authlist);
594: authctxt->authlist = NULL;
1.172 djm 595: if (authctxt->method != NULL && authctxt->method->cleanup != NULL)
1.295 djm 596: authctxt->method->cleanup(ssh);
1.197 djm 597: free(authctxt->methoddata);
598: authctxt->methoddata = NULL;
1.20 markus 599: authctxt->success = 1; /* break out */
1.218 markus 600: return 0;
1.20 markus 601: }
1.105 deraadt 602:
1.302 djm 603: #if 0
604: static int
1.261 markus 605: input_userauth_success_unexpected(int type, u_int32_t seq, struct ssh *ssh)
1.172 djm 606: {
1.260 markus 607: Authctxt *authctxt = ssh->authctxt;
1.172 djm 608:
609: if (authctxt == NULL)
1.331 djm 610: fatal_f("no authentication context");
1.172 djm 611:
612: fatal("Unexpected authentication success during %s.",
613: authctxt->method->name);
1.218 markus 614: return 0;
1.172 djm 615: }
1.302 djm 616: #endif
1.172 djm 617:
1.302 djm 618: static int
1.261 markus 619: input_userauth_failure(int type, u_int32_t seq, struct ssh *ssh)
1.20 markus 620: {
1.260 markus 621: Authctxt *authctxt = ssh->authctxt;
1.20 markus 622: char *authlist = NULL;
1.278 markus 623: u_char partial;
1.20 markus 624:
625: if (authctxt == NULL)
626: fatal("input_userauth_failure: no authentication context");
627:
1.307 dtucker 628: if (sshpkt_get_cstring(ssh, &authlist, NULL) != 0 ||
629: sshpkt_get_u8(ssh, &partial) != 0 ||
630: sshpkt_get_end(ssh) != 0)
1.278 markus 631: goto out;
1.20 markus 632:
1.193 markus 633: if (partial != 0) {
1.351 djm 634: verbose("Authenticated using \"%s\" with partial success.",
635: authctxt->method->name);
1.193 markus 636: /* reset state */
1.251 djm 637: pubkey_reset(authctxt);
1.193 markus 638: }
1.109 markus 639: debug("Authentications that can continue: %s", authlist);
1.20 markus 640:
1.295 djm 641: userauth(ssh, authlist);
1.278 markus 642: authlist = NULL;
643: out:
644: free(authlist);
1.218 markus 645: return 0;
1.51 markus 646: }
1.169 djm 647:
1.287 djm 648: /*
649: * Format an identity for logging including filename, key type, fingerprint
650: * and location (agent, etc.). Caller must free.
651: */
652: static char *
653: format_identity(Identity *id)
654: {
655: char *fp = NULL, *ret = NULL;
1.309 djm 656: const char *note = "";
1.287 djm 657:
658: if (id->key != NULL) {
1.347 djm 659: fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1.287 djm 660: SSH_FP_DEFAULT);
661: }
1.309 djm 662: if (id->key) {
663: if ((id->key->flags & SSHKEY_FLAG_EXT) != 0)
664: note = " token";
1.311 markus 665: else if (sshkey_is_sk(id->key))
1.319 naddy 666: note = " authenticator";
1.309 djm 667: }
1.287 djm 668: xasprintf(&ret, "%s %s%s%s%s%s%s",
669: id->filename,
670: id->key ? sshkey_type(id->key) : "", id->key ? " " : "",
671: fp ? fp : "",
1.309 djm 672: id->userprovided ? " explicit" : "", note,
1.287 djm 673: id->agent_fd != -1 ? " agent" : "");
674: free(fp);
675: return ret;
676: }
677:
1.302 djm 678: static int
1.261 markus 679: input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
1.51 markus 680: {
1.260 markus 681: Authctxt *authctxt = ssh->authctxt;
1.259 markus 682: struct sshkey *key = NULL;
1.117 markus 683: Identity *id = NULL;
1.287 djm 684: int pktype, found = 0, sent = 0;
1.278 markus 685: size_t blen;
1.287 djm 686: char *pkalg = NULL, *fp = NULL, *ident = NULL;
1.278 markus 687: u_char *pkblob = NULL;
688: int r;
1.51 markus 689:
690: if (authctxt == NULL)
691: fatal("input_userauth_pk_ok: no authentication context");
1.267 djm 692:
1.278 markus 693: if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
694: (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
695: (r = sshpkt_get_end(ssh)) != 0)
696: goto done;
1.51 markus 697:
1.278 markus 698: if ((pktype = sshkey_type_from_name(pkalg)) == KEY_UNSPEC) {
1.331 djm 699: debug_f("server sent unknown pkalg %s", pkalg);
1.117 markus 700: goto done;
701: }
1.278 markus 702: if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
1.331 djm 703: debug_r(r, "no key from blob. pkalg %s", pkalg);
1.117 markus 704: goto done;
705: }
706: if (key->type != pktype) {
707: error("input_userauth_pk_ok: type mismatch "
708: "for decoded key (received %d, expected %d)",
709: key->type, pktype);
710: goto done;
711: }
712:
1.127 markus 713: /*
714: * search keys in the reverse order, because last candidate has been
715: * moved to the end of the queue. this also avoids confusion by
716: * duplicate keys
717: */
1.136 henning 718: TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) {
1.278 markus 719: if (sshkey_equal(key, id->key)) {
1.287 djm 720: found = 1;
1.51 markus 721: break;
722: }
1.117 markus 723: }
1.287 djm 724: if (!found || id == NULL) {
725: fp = sshkey_fingerprint(key, options.fingerprint_hash,
726: SSH_FP_DEFAULT);
1.331 djm 727: error_f("server replied with unknown key: %s %s",
1.287 djm 728: sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
729: goto done;
730: }
731: ident = format_identity(id);
732: debug("Server accepts key: %s", ident);
1.295 djm 733: sent = sign_and_send_pubkey(ssh, id);
1.278 markus 734: r = 0;
735: done:
736: sshkey_free(key);
1.287 djm 737: free(ident);
738: free(fp);
1.197 djm 739: free(pkalg);
740: free(pkblob);
1.51 markus 741:
1.106 deraadt 742: /* try another method if we did not send a packet */
1.278 markus 743: if (r == 0 && sent == 0)
1.295 djm 744: userauth(ssh, NULL);
1.278 markus 745: return r;
1.20 markus 746: }
1.121 markus 747:
748: #ifdef GSSAPI
1.302 djm 749: static int
1.295 djm 750: userauth_gssapi(struct ssh *ssh)
1.121 markus 751: {
1.295 djm 752: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.121 markus 753: Gssctxt *gssctxt = NULL;
754: OM_uint32 min;
1.278 markus 755: int r, ok = 0;
1.302 djm 756: gss_OID mech = NULL;
1.121 markus 757:
758: /* Try one GSSAPI method at a time, rather than sending them all at
759: * once. */
760:
1.302 djm 761: if (authctxt->gss_supported_mechs == NULL)
762: gss_indicate_mechs(&min, &authctxt->gss_supported_mechs);
1.121 markus 763:
1.302 djm 764: /* Check to see whether the mechanism is usable before we offer it */
765: while (authctxt->mech_tried < authctxt->gss_supported_mechs->count &&
766: !ok) {
767: mech = &authctxt->gss_supported_mechs->
768: elements[authctxt->mech_tried];
1.121 markus 769: /* My DER encoding requires length<128 */
1.302 djm 770: if (mech->length < 128 && ssh_gssapi_check_mechanism(&gssctxt,
771: mech, authctxt->host)) {
1.121 markus 772: ok = 1; /* Mechanism works */
773: } else {
1.302 djm 774: authctxt->mech_tried++;
1.121 markus 775: }
776: }
777:
1.302 djm 778: if (!ok || mech == NULL)
1.139 djm 779: return 0;
1.121 markus 780:
781: authctxt->methoddata=(void *)gssctxt;
782:
1.278 markus 783: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
784: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
785: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
786: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
787: (r = sshpkt_put_u32(ssh, 1)) != 0 ||
1.302 djm 788: (r = sshpkt_put_u32(ssh, (mech->length) + 2)) != 0 ||
1.278 markus 789: (r = sshpkt_put_u8(ssh, SSH_GSS_OIDTYPE)) != 0 ||
1.302 djm 790: (r = sshpkt_put_u8(ssh, mech->length)) != 0 ||
791: (r = sshpkt_put(ssh, mech->elements, mech->length)) != 0 ||
1.278 markus 792: (r = sshpkt_send(ssh)) != 0)
1.331 djm 793: fatal_fr(r, "send packet");
1.278 markus 794:
795: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response);
796: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
797: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error);
798: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
1.121 markus 799:
1.302 djm 800: authctxt->mech_tried++; /* Move along to next candidate */
1.121 markus 801:
802: return 1;
803: }
804:
1.302 djm 805: static void
806: userauth_gssapi_cleanup(struct ssh *ssh)
807: {
808: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
809: Gssctxt *gssctxt = (Gssctxt *)authctxt->methoddata;
810:
811: ssh_gssapi_delete_ctx(&gssctxt);
812: authctxt->methoddata = NULL;
813:
814: free(authctxt->gss_supported_mechs);
815: authctxt->gss_supported_mechs = NULL;
816: }
817:
1.130 markus 818: static OM_uint32
1.262 djm 819: process_gssapi_token(struct ssh *ssh, gss_buffer_t recv_tok)
1.130 markus 820: {
1.260 markus 821: Authctxt *authctxt = ssh->authctxt;
1.130 markus 822: Gssctxt *gssctxt = authctxt->methoddata;
823: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
1.142 djm 824: gss_buffer_desc mic = GSS_C_EMPTY_BUFFER;
825: gss_buffer_desc gssbuf;
1.132 markus 826: OM_uint32 status, ms, flags;
1.278 markus 827: int r;
1.133 djm 828:
1.130 markus 829: status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.132 markus 830: recv_tok, &send_tok, &flags);
1.130 markus 831:
832: if (send_tok.length > 0) {
1.278 markus 833: u_char type = GSS_ERROR(status) ?
834: SSH2_MSG_USERAUTH_GSSAPI_ERRTOK :
835: SSH2_MSG_USERAUTH_GSSAPI_TOKEN;
836:
837: if ((r = sshpkt_start(ssh, type)) != 0 ||
838: (r = sshpkt_put_string(ssh, send_tok.value,
839: send_tok.length)) != 0 ||
840: (r = sshpkt_send(ssh)) != 0)
1.331 djm 841: fatal_fr(r, "send %u packet", type);
1.133 djm 842:
1.130 markus 843: gss_release_buffer(&ms, &send_tok);
844: }
1.133 djm 845:
1.130 markus 846: if (status == GSS_S_COMPLETE) {
1.132 markus 847: /* send either complete or MIC, depending on mechanism */
848: if (!(flags & GSS_C_INTEG_FLAG)) {
1.278 markus 849: if ((r = sshpkt_start(ssh,
850: SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE)) != 0 ||
851: (r = sshpkt_send(ssh)) != 0)
1.331 djm 852: fatal_fr(r, "send completion");
1.132 markus 853: } else {
1.278 markus 854: struct sshbuf *b;
855:
856: if ((b = sshbuf_new()) == NULL)
1.331 djm 857: fatal_f("sshbuf_new failed");
1.278 markus 858: ssh_gssapi_buildmic(b, authctxt->server_user,
1.346 djm 859: authctxt->service, "gssapi-with-mic",
860: ssh->kex->session_id);
1.132 markus 861:
1.278 markus 862: if ((gssbuf.value = sshbuf_mutable_ptr(b)) == NULL)
1.331 djm 863: fatal_f("sshbuf_mutable_ptr failed");
1.278 markus 864: gssbuf.length = sshbuf_len(b);
1.133 djm 865:
1.132 markus 866: status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic);
1.133 djm 867:
1.132 markus 868: if (!GSS_ERROR(status)) {
1.278 markus 869: if ((r = sshpkt_start(ssh,
870: SSH2_MSG_USERAUTH_GSSAPI_MIC)) != 0 ||
871: (r = sshpkt_put_string(ssh, mic.value,
872: mic.length)) != 0 ||
873: (r = sshpkt_send(ssh)) != 0)
1.331 djm 874: fatal_fr(r, "send MIC");
1.132 markus 875: }
1.133 djm 876:
1.278 markus 877: sshbuf_free(b);
1.132 markus 878: gss_release_buffer(&ms, &mic);
1.133 djm 879: }
1.130 markus 880: }
1.133 djm 881:
1.130 markus 882: return status;
883: }
884:
1.302 djm 885: static int
1.261 markus 886: input_gssapi_response(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 887: {
1.260 markus 888: Authctxt *authctxt = ssh->authctxt;
1.121 markus 889: Gssctxt *gssctxt;
1.278 markus 890: size_t oidlen;
891: u_char *oidv = NULL;
892: int r;
1.121 markus 893:
894: if (authctxt == NULL)
895: fatal("input_gssapi_response: no authentication context");
896: gssctxt = authctxt->methoddata;
897:
898: /* Setup our OID */
1.278 markus 899: if ((r = sshpkt_get_string(ssh, &oidv, &oidlen)) != 0)
900: goto done;
1.121 markus 901:
1.129 markus 902: if (oidlen <= 2 ||
903: oidv[0] != SSH_GSS_OIDTYPE ||
904: oidv[1] != oidlen - 2) {
905: debug("Badly encoded mechanism OID received");
1.296 djm 906: userauth(ssh, NULL);
1.278 markus 907: goto ok;
1.121 markus 908: }
1.129 markus 909:
910: if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2))
911: fatal("Server returned different OID than expected");
1.121 markus 912:
1.278 markus 913: if ((r = sshpkt_get_end(ssh)) != 0)
914: goto done;
1.121 markus 915:
1.262 djm 916: if (GSS_ERROR(process_gssapi_token(ssh, GSS_C_NO_BUFFER))) {
1.121 markus 917: /* Start again with next method on list */
918: debug("Trying to start again");
1.296 djm 919: userauth(ssh, NULL);
1.278 markus 920: goto ok;
1.121 markus 921: }
1.278 markus 922: ok:
923: r = 0;
924: done:
925: free(oidv);
926: return r;
1.121 markus 927: }
928:
1.302 djm 929: static int
1.261 markus 930: input_gssapi_token(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 931: {
1.260 markus 932: Authctxt *authctxt = ssh->authctxt;
1.121 markus 933: gss_buffer_desc recv_tok;
1.278 markus 934: u_char *p = NULL;
935: size_t len;
1.130 markus 936: OM_uint32 status;
1.278 markus 937: int r;
1.121 markus 938:
939: if (authctxt == NULL)
940: fatal("input_gssapi_response: no authentication context");
941:
1.278 markus 942: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
943: (r = sshpkt_get_end(ssh)) != 0)
944: goto out;
1.121 markus 945:
1.278 markus 946: recv_tok.value = p;
947: recv_tok.length = len;
1.262 djm 948: status = process_gssapi_token(ssh, &recv_tok);
1.121 markus 949:
1.278 markus 950: /* Start again with the next method in the list */
1.121 markus 951: if (GSS_ERROR(status)) {
1.296 djm 952: userauth(ssh, NULL);
1.278 markus 953: /* ok */
1.121 markus 954: }
1.278 markus 955: r = 0;
956: out:
957: free(p);
958: return r;
1.121 markus 959: }
960:
1.302 djm 961: static int
1.261 markus 962: input_gssapi_errtok(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 963: {
1.260 markus 964: Authctxt *authctxt = ssh->authctxt;
1.121 markus 965: Gssctxt *gssctxt;
966: gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
967: gss_buffer_desc recv_tok;
1.194 djm 968: OM_uint32 ms;
1.278 markus 969: u_char *p = NULL;
970: size_t len;
971: int r;
1.121 markus 972:
973: if (authctxt == NULL)
974: fatal("input_gssapi_response: no authentication context");
975: gssctxt = authctxt->methoddata;
976:
1.278 markus 977: if ((r = sshpkt_get_string(ssh, &p, &len)) != 0 ||
978: (r = sshpkt_get_end(ssh)) != 0) {
979: free(p);
980: return r;
981: }
1.121 markus 982:
983: /* Stick it into GSSAPI and see what it says */
1.278 markus 984: recv_tok.value = p;
985: recv_tok.length = len;
1.194 djm 986: (void)ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds,
1.140 djm 987: &recv_tok, &send_tok, NULL);
1.278 markus 988: free(p);
1.121 markus 989: gss_release_buffer(&ms, &send_tok);
990:
991: /* Server will be returning a failed packet after this one */
1.220 djm 992: return 0;
1.121 markus 993: }
994:
1.302 djm 995: static int
1.261 markus 996: input_gssapi_error(int type, u_int32_t plen, struct ssh *ssh)
1.121 markus 997: {
1.278 markus 998: char *msg = NULL;
999: char *lang = NULL;
1000: int r;
1.121 markus 1001:
1.278 markus 1002: if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* maj */
1003: (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* min */
1004: (r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1005: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1006: goto out;
1007: r = sshpkt_get_end(ssh);
1.143 stevesk 1008: debug("Server GSSAPI Error:\n%s", msg);
1.278 markus 1009: out:
1.197 djm 1010: free(msg);
1011: free(lang);
1.278 markus 1012: return r;
1.121 markus 1013: }
1014: #endif /* GSSAPI */
1.20 markus 1015:
1.302 djm 1016: static int
1.295 djm 1017: userauth_none(struct ssh *ssh)
1.23 markus 1018: {
1.295 djm 1019: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1020: int r;
1021:
1.23 markus 1022: /* initial userauth request */
1.278 markus 1023: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1024: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1025: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1026: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1027: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1028: fatal_fr(r, "send packet");
1.23 markus 1029: return 1;
1030: }
1031:
1.302 djm 1032: static int
1.295 djm 1033: userauth_passwd(struct ssh *ssh)
1.1 markus 1034: {
1.295 djm 1035: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.290 djm 1036: char *password, *prompt = NULL;
1.175 dtucker 1037: const char *host = options.host_key_alias ? options.host_key_alias :
1038: authctxt->host;
1.278 markus 1039: int r;
1.6 markus 1040:
1.292 djm 1041: if (authctxt->attempt_passwd++ >= options.number_of_password_prompts)
1.6 markus 1042: return 0;
1.13 todd 1043:
1.292 djm 1044: if (authctxt->attempt_passwd != 1)
1.13 todd 1045: error("Permission denied, please try again.");
1.1 markus 1046:
1.290 djm 1047: xasprintf(&prompt, "%s@%s's password: ", authctxt->server_user, host);
1.1 markus 1048: password = read_passphrase(prompt, 0);
1.278 markus 1049: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1050: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1051: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1052: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1053: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1054: (r = sshpkt_put_cstring(ssh, password)) != 0 ||
1055: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1056: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1057: fatal_fr(r, "send packet");
1.99 markus 1058:
1.290 djm 1059: free(prompt);
1060: if (password != NULL)
1.278 markus 1061: freezero(password, strlen(password));
1062:
1063: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1064: &input_userauth_passwd_changereq);
1065:
1.1 markus 1066: return 1;
1067: }
1.169 djm 1068:
1.99 markus 1069: /*
1070: * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST
1071: */
1.302 djm 1072: static int
1.261 markus 1073: input_userauth_passwd_changereq(int type, u_int32_t seqnr, struct ssh *ssh)
1.99 markus 1074: {
1.260 markus 1075: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1076: char *info = NULL, *lang = NULL, *password = NULL, *retype = NULL;
1.266 dtucker 1077: char prompt[256];
1.252 djm 1078: const char *host;
1.278 markus 1079: int r;
1.99 markus 1080:
1081: debug2("input_userauth_passwd_changereq");
1082:
1083: if (authctxt == NULL)
1084: fatal("input_userauth_passwd_changereq: "
1085: "no authentication context");
1.252 djm 1086: host = options.host_key_alias ? options.host_key_alias : authctxt->host;
1.99 markus 1087:
1.278 markus 1088: if ((r = sshpkt_get_cstring(ssh, &info, NULL)) != 0 ||
1089: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1090: goto out;
1.99 markus 1091: if (strlen(info) > 0)
1.116 itojun 1092: logit("%s", info);
1.278 markus 1093: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1094: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1095: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1096: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1097: (r = sshpkt_put_u8(ssh, 1)) != 0) /* additional info */
1098: goto out;
1099:
1.104 deraadt 1100: snprintf(prompt, sizeof(prompt),
1.99 markus 1101: "Enter %.30s@%.128s's old password: ",
1.175 dtucker 1102: authctxt->server_user, host);
1.99 markus 1103: password = read_passphrase(prompt, 0);
1.278 markus 1104: if ((r = sshpkt_put_cstring(ssh, password)) != 0)
1105: goto out;
1106:
1107: freezero(password, strlen(password));
1.99 markus 1108: password = NULL;
1109: while (password == NULL) {
1.104 deraadt 1110: snprintf(prompt, sizeof(prompt),
1.99 markus 1111: "Enter %.30s@%.128s's new password: ",
1.175 dtucker 1112: authctxt->server_user, host);
1.99 markus 1113: password = read_passphrase(prompt, RP_ALLOW_EOF);
1114: if (password == NULL) {
1115: /* bail out */
1.278 markus 1116: r = 0;
1117: goto out;
1.99 markus 1118: }
1.104 deraadt 1119: snprintf(prompt, sizeof(prompt),
1.99 markus 1120: "Retype %.30s@%.128s's new password: ",
1.175 dtucker 1121: authctxt->server_user, host);
1.99 markus 1122: retype = read_passphrase(prompt, 0);
1123: if (strcmp(password, retype) != 0) {
1.278 markus 1124: freezero(password, strlen(password));
1.116 itojun 1125: logit("Mismatch; try again, EOF to quit.");
1.99 markus 1126: password = NULL;
1127: }
1.278 markus 1128: freezero(retype, strlen(retype));
1.99 markus 1129: }
1.278 markus 1130: if ((r = sshpkt_put_cstring(ssh, password)) != 0 ||
1131: (r = sshpkt_add_padding(ssh, 64)) != 0 ||
1132: (r = sshpkt_send(ssh)) != 0)
1133: goto out;
1.104 deraadt 1134:
1.278 markus 1135: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ,
1.99 markus 1136: &input_userauth_passwd_changereq);
1.278 markus 1137: r = 0;
1138: out:
1139: if (password)
1140: freezero(password, strlen(password));
1141: free(info);
1142: free(lang);
1143: return r;
1.117 markus 1144: }
1145:
1.272 djm 1146: /*
1147: * Select an algorithm for publickey signatures.
1148: * Returns algorithm (caller must free) or NULL if no mutual algorithm found.
1149: *
1150: * Call with ssh==NULL to ignore server-sig-algs extension list and
1151: * only attempt with the key's base signature type.
1152: */
1153: static char *
1154: key_sig_algorithm(struct ssh *ssh, const struct sshkey *key)
1.231 markus 1155: {
1.274 djm 1156: char *allowed, *oallowed, *cp, *tmp, *alg = NULL;
1.348 djm 1157: const char *server_sig_algs;
1.231 markus 1158:
1.272 djm 1159: /*
1160: * The signature algorithm will only differ from the key algorithm
1161: * for RSA keys/certs and when the server advertises support for
1162: * newer (SHA2) algorithms.
1163: */
1164: if (ssh == NULL || ssh->kex->server_sig_algs == NULL ||
1.288 djm 1165: (key->type != KEY_RSA && key->type != KEY_RSA_CERT) ||
1.345 djm 1166: (key->type == KEY_RSA_CERT && (ssh->compat & SSH_BUG_SIGTYPE))) {
1.272 djm 1167: /* Filter base key signature alg against our configuration */
1.279 markus 1168: return match_list(sshkey_ssh_name(key),
1.342 dtucker 1169: options.pubkey_accepted_algos, NULL);
1.231 markus 1170: }
1171:
1.272 djm 1172: /*
1.348 djm 1173: * Workaround OpenSSH 7.4 bug: this version supports RSA/SHA-2 but
1174: * fails to advertise it via SSH2_MSG_EXT_INFO.
1175: */
1176: server_sig_algs = ssh->kex->server_sig_algs;
1177: if (key->type == KEY_RSA && (ssh->compat & SSH_BUG_SIGTYPE74))
1178: server_sig_algs = "rsa-sha2-256,rsa-sha2-512";
1179:
1180: /*
1.272 djm 1181: * For RSA keys/certs, since these might have a different sig type:
1.342 dtucker 1182: * find the first entry in PubkeyAcceptedAlgorithms of the right type
1.272 djm 1183: * that also appears in the supported signature algorithms list from
1184: * the server.
1185: */
1.342 dtucker 1186: oallowed = allowed = xstrdup(options.pubkey_accepted_algos);
1.272 djm 1187: while ((cp = strsep(&allowed, ",")) != NULL) {
1188: if (sshkey_type_from_name(cp) != key->type)
1189: continue;
1.323 djm 1190: tmp = match_list(sshkey_sigalg_by_name(cp),
1.348 djm 1191: server_sig_algs, NULL);
1.274 djm 1192: if (tmp != NULL)
1193: alg = xstrdup(cp);
1194: free(tmp);
1.272 djm 1195: if (alg != NULL)
1196: break;
1.269 djm 1197: }
1.272 djm 1198: free(oallowed);
1199: return alg;
1.269 djm 1200: }
1201:
1.117 markus 1202: static int
1.214 djm 1203: identity_sign(struct identity *id, u_char **sigp, size_t *lenp,
1.272 djm 1204: const u_char *data, size_t datalen, u_int compat, const char *alg)
1.117 markus 1205: {
1.309 djm 1206: struct sshkey *sign_key = NULL, *prv = NULL;
1.360 djm 1207: int is_agent = 0, retried = 0, r = SSH_ERR_INTERNAL_ERROR;
1.312 djm 1208: struct notifier_ctx *notifier = NULL;
1.325 djm 1209: char *fp = NULL, *pin = NULL, *prompt = NULL;
1.309 djm 1210:
1211: *sigp = NULL;
1212: *lenp = 0;
1.99 markus 1213:
1.272 djm 1214: /* The agent supports this key. */
1.269 djm 1215: if (id->key != NULL && id->agent_fd != -1) {
1.272 djm 1216: return ssh_agent_sign(id->agent_fd, id->key, sigp, lenp,
1217: data, datalen, alg, compat);
1.269 djm 1218: }
1.214 djm 1219:
1.117 markus 1220: /*
1.272 djm 1221: * We have already loaded the private key or the private key is
1222: * stored in external hardware.
1.117 markus 1223: */
1.255 djm 1224: if (id->key != NULL &&
1.272 djm 1225: (id->isprivate || (id->key->flags & SSHKEY_FLAG_EXT))) {
1.309 djm 1226: sign_key = id->key;
1.360 djm 1227: is_agent = 1;
1.309 djm 1228: } else {
1229: /* Load the private key from the file. */
1230: if ((prv = load_identity_file(id)) == NULL)
1231: return SSH_ERR_KEY_NOT_FOUND;
1232: if (id->key != NULL && !sshkey_equal_public(prv, id->key)) {
1.331 djm 1233: error_f("private key %s contents do not match public",
1.347 djm 1234: id->filename);
1.309 djm 1235: r = SSH_ERR_KEY_NOT_FOUND;
1236: goto out;
1237: }
1238: sign_key = prv;
1.360 djm 1239: }
1.341 djm 1240: retry_pin:
1.360 djm 1241: /* Prompt for touch for non-agent FIDO keys that request UP */
1242: if (!is_agent && sshkey_is_sk(sign_key) &&
1243: (sign_key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
1244: /* XXX should batch mode just skip these? */
1245: if ((fp = sshkey_fingerprint(sign_key,
1246: options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1247: fatal_f("fingerprint failed");
1248: notifier = notify_start(options.batch_mode,
1249: "Confirm user presence for key %s %s",
1250: sshkey_type(sign_key), fp);
1251: free(fp);
1.272 djm 1252: }
1.310 djm 1253: if ((r = sshkey_sign(sign_key, sigp, lenp, data, datalen,
1.325 djm 1254: alg, options.sk_provider, pin, compat)) != 0) {
1.331 djm 1255: debug_fr(r, "sshkey_sign");
1.360 djm 1256: if (!retried && pin == NULL && !is_agent &&
1257: sshkey_is_sk(sign_key) &&
1.341 djm 1258: r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
1259: notify_complete(notifier, NULL);
1260: notifier = NULL;
1.360 djm 1261: xasprintf(&prompt, "Enter PIN for %s key %s: ",
1262: sshkey_type(sign_key), id->filename);
1263: pin = read_passphrase(prompt, 0);
1.341 djm 1264: retried = 1;
1265: goto retry_pin;
1266: }
1.309 djm 1267: goto out;
1268: }
1.341 djm 1269:
1.309 djm 1270: /*
1271: * PKCS#11 tokens may not support all signature algorithms,
1272: * so check what we get back.
1273: */
1274: if ((r = sshkey_check_sigtype(*sigp, *lenp, alg)) != 0) {
1.331 djm 1275: debug_fr(r, "sshkey_check_sigtype");
1.309 djm 1276: goto out;
1.265 djm 1277: }
1.309 djm 1278: /* success */
1279: r = 0;
1280: out:
1.325 djm 1281: free(prompt);
1282: if (pin != NULL)
1283: freezero(pin, strlen(pin));
1.341 djm 1284: notify_complete(notifier, r == 0 ? "User presence confirmed" : NULL);
1.214 djm 1285: sshkey_free(prv);
1.269 djm 1286: return r;
1.51 markus 1287: }
1288:
1.76 itojun 1289: static int
1.255 djm 1290: id_filename_matches(Identity *id, Identity *private_id)
1291: {
1.356 djm 1292: static const char * const suffixes[] = { ".pub", "-cert.pub", NULL };
1.255 djm 1293: size_t len = strlen(id->filename), plen = strlen(private_id->filename);
1294: size_t i, slen;
1295:
1296: if (strcmp(id->filename, private_id->filename) == 0)
1297: return 1;
1298: for (i = 0; suffixes[i]; i++) {
1299: slen = strlen(suffixes[i]);
1300: if (len > slen && plen == len - slen &&
1301: strcmp(id->filename + (len - slen), suffixes[i]) == 0 &&
1302: memcmp(id->filename, private_id->filename, plen) == 0)
1303: return 1;
1304: }
1305: return 0;
1306: }
1307:
1308: static int
1.295 djm 1309: sign_and_send_pubkey(struct ssh *ssh, Identity *id)
1.1 markus 1310: {
1.295 djm 1311: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1312: struct sshbuf *b = NULL;
1313: Identity *private_id, *sign_id = NULL;
1314: u_char *signature = NULL;
1315: size_t slen = 0, skip = 0;
1316: int r, fallback_sigtype, sent = 0;
1317: char *alg = NULL, *fp = NULL;
1.353 djm 1318: const char *loc = "", *method = "publickey";
1.354 djm 1319: int hostbound = 0;
1.353 djm 1320:
1321: /* prefer host-bound pubkey signatures if supported by server */
1.354 djm 1322: if ((ssh->kex->flags & KEX_HAS_PUBKEY_HOSTBOUND) != 0 &&
1323: (options.pubkey_authentication & SSH_PUBKEY_AUTH_HBOUND) != 0) {
1324: hostbound = 1;
1.353 djm 1325: method = "publickey-hostbound-v00@openssh.com";
1.354 djm 1326: }
1.1 markus 1327:
1.222 djm 1328: if ((fp = sshkey_fingerprint(id->key, options.fingerprint_hash,
1329: SSH_FP_DEFAULT)) == NULL)
1330: return 0;
1.51 markus 1331:
1.354 djm 1332: debug3_f("using %s with %s %s", method, sshkey_type(id->key), fp);
1.1 markus 1333:
1.227 djm 1334: /*
1335: * If the key is an certificate, try to find a matching private key
1336: * and use it to complete the signature.
1.241 djm 1337: * If no such private key exists, fall back to trying the certificate
1338: * key itself in case it has a private half already loaded.
1.272 djm 1339: * This will try to set sign_id to the private key that will perform
1340: * the signature.
1.227 djm 1341: */
1.272 djm 1342: if (sshkey_is_cert(id->key)) {
1.227 djm 1343: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1344: if (sshkey_equal_public(id->key, private_id->key) &&
1345: id->key->type != private_id->key->type) {
1.272 djm 1346: sign_id = private_id;
1.227 djm 1347: break;
1348: }
1349: }
1.255 djm 1350: /*
1351: * Exact key matches are preferred, but also allow
1352: * filename matches for non-PKCS#11/agent keys that
1353: * didn't load public keys. This supports the case
1354: * of keeping just a private key file and public
1355: * certificate on disk.
1356: */
1.272 djm 1357: if (sign_id == NULL &&
1358: !id->isprivate && id->agent_fd == -1 &&
1.255 djm 1359: (id->key->flags & SSHKEY_FLAG_EXT) == 0) {
1360: TAILQ_FOREACH(private_id, &authctxt->keys, next) {
1361: if (private_id->key == NULL &&
1362: id_filename_matches(id, private_id)) {
1.272 djm 1363: sign_id = private_id;
1.255 djm 1364: break;
1365: }
1366: }
1367: }
1.272 djm 1368: if (sign_id != NULL) {
1.331 djm 1369: debug2_f("using private key \"%s\"%s for "
1.349 djm 1370: "certificate", sign_id->filename,
1371: sign_id->agent_fd != -1 ? " from agent" : "");
1.227 djm 1372: } else {
1.331 djm 1373: debug_f("no separate private key for certificate "
1374: "\"%s\"", id->filename);
1.227 djm 1375: }
1376: }
1377:
1.272 djm 1378: /*
1379: * If the above didn't select another identity to do the signing
1380: * then default to the one we started with.
1381: */
1382: if (sign_id == NULL)
1383: sign_id = id;
1384:
1385: /* assemble and sign data */
1386: for (fallback_sigtype = 0; fallback_sigtype <= 1; fallback_sigtype++) {
1387: free(alg);
1388: slen = 0;
1389: signature = NULL;
1390: if ((alg = key_sig_algorithm(fallback_sigtype ? NULL : ssh,
1391: id->key)) == NULL) {
1.331 djm 1392: error_f("no mutual signature supported");
1.272 djm 1393: goto out;
1394: }
1.331 djm 1395: debug3_f("signing using %s %s", alg, fp);
1.272 djm 1396:
1397: sshbuf_free(b);
1398: if ((b = sshbuf_new()) == NULL)
1.331 djm 1399: fatal_f("sshbuf_new failed");
1.345 djm 1400: if (ssh->compat & SSH_OLD_SESSIONID) {
1.346 djm 1401: if ((r = sshbuf_putb(b, ssh->kex->session_id)) != 0)
1402: fatal_fr(r, "sshbuf_putb");
1.272 djm 1403: } else {
1.346 djm 1404: if ((r = sshbuf_put_stringb(b,
1405: ssh->kex->session_id)) != 0)
1406: fatal_fr(r, "sshbuf_put_stringb");
1.272 djm 1407: }
1.278 markus 1408: skip = sshbuf_len(b);
1.272 djm 1409: if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1410: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1411: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.353 djm 1412: (r = sshbuf_put_cstring(b, method)) != 0 ||
1.272 djm 1413: (r = sshbuf_put_u8(b, 1)) != 0 ||
1414: (r = sshbuf_put_cstring(b, alg)) != 0 ||
1415: (r = sshkey_puts(id->key, b)) != 0) {
1.331 djm 1416: fatal_fr(r, "assemble signed data");
1.272 djm 1417: }
1.354 djm 1418: if (hostbound) {
1.353 djm 1419: if (ssh->kex->initial_hostkey == NULL) {
1420: fatal_f("internal error: initial hostkey "
1421: "not recorded");
1422: }
1423: if ((r = sshkey_puts(ssh->kex->initial_hostkey, b)) != 0)
1424: fatal_fr(r, "assemble %s hostkey", method);
1425: }
1.272 djm 1426: /* generate signature */
1427: r = identity_sign(sign_id, &signature, &slen,
1.345 djm 1428: sshbuf_ptr(b), sshbuf_len(b), ssh->compat, alg);
1.272 djm 1429: if (r == 0)
1430: break;
1431: else if (r == SSH_ERR_KEY_NOT_FOUND)
1432: goto out; /* soft failure */
1433: else if (r == SSH_ERR_SIGN_ALG_UNSUPPORTED &&
1434: !fallback_sigtype) {
1435: if (sign_id->agent_fd != -1)
1436: loc = "agent ";
1437: else if ((sign_id->key->flags & SSHKEY_FLAG_EXT) != 0)
1438: loc = "token ";
1439: logit("%skey %s %s returned incorrect signature type",
1440: loc, sshkey_type(id->key), fp);
1441: continue;
1442: }
1.331 djm 1443: error_fr(r, "signing failed for %s \"%s\"%s",
1.315 djm 1444: sshkey_type(sign_id->key), sign_id->filename,
1.331 djm 1445: id->agent_fd != -1 ? " from agent" : "");
1.272 djm 1446: goto out;
1.17 markus 1447: }
1.272 djm 1448: if (slen == 0 || signature == NULL) /* shouldn't happen */
1.331 djm 1449: fatal_f("no signature");
1.51 markus 1450:
1.1 markus 1451: /* append signature */
1.272 djm 1452: if ((r = sshbuf_put_string(b, signature, slen)) != 0)
1.331 djm 1453: fatal_fr(r, "append signature");
1.1 markus 1454:
1.272 djm 1455: #ifdef DEBUG_PK
1456: sshbuf_dump(b, stderr);
1457: #endif
1.1 markus 1458: /* skip session id and packet type */
1.272 djm 1459: if ((r = sshbuf_consume(b, skip + 1)) != 0)
1.331 djm 1460: fatal_fr(r, "consume");
1.1 markus 1461:
1462: /* put remaining data from buffer into packet */
1.272 djm 1463: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1464: (r = sshpkt_putb(ssh, b)) != 0 ||
1465: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1466: fatal_fr(r, "enqueue request");
1.272 djm 1467:
1468: /* success */
1469: sent = 1;
1.17 markus 1470:
1.272 djm 1471: out:
1472: free(fp);
1473: free(alg);
1474: sshbuf_free(b);
1475: freezero(signature, slen);
1476: return sent;
1.16 markus 1477: }
1478:
1.76 itojun 1479: static int
1.295 djm 1480: send_pubkey_test(struct ssh *ssh, Identity *id)
1.20 markus 1481: {
1.295 djm 1482: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.272 djm 1483: u_char *blob = NULL;
1484: char *alg = NULL;
1.278 markus 1485: size_t bloblen;
1486: u_int have_sig = 0;
1487: int sent = 0, r;
1.20 markus 1488:
1.272 djm 1489: if ((alg = key_sig_algorithm(ssh, id->key)) == NULL) {
1.331 djm 1490: debug_f("no mutual signature algorithm");
1.272 djm 1491: goto out;
1492: }
1.16 markus 1493:
1.278 markus 1494: if ((r = sshkey_to_blob(id->key, &blob, &bloblen)) != 0) {
1.51 markus 1495: /* we cannot handle this key */
1.331 djm 1496: debug3_f("cannot handle key");
1.272 djm 1497: goto out;
1.16 markus 1498: }
1.51 markus 1499: /* register callback for USERAUTH_PK_OK message */
1.278 markus 1500: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok);
1.51 markus 1501:
1.278 markus 1502: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1503: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1504: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1505: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1506: (r = sshpkt_put_u8(ssh, have_sig)) != 0 ||
1507: (r = sshpkt_put_cstring(ssh, alg)) != 0 ||
1508: (r = sshpkt_put_string(ssh, blob, bloblen)) != 0 ||
1509: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1510: fatal_fr(r, "send packet");
1.272 djm 1511: sent = 1;
1.278 markus 1512:
1513: out:
1.272 djm 1514: free(alg);
1.197 djm 1515: free(blob);
1.272 djm 1516: return sent;
1.51 markus 1517: }
1518:
1.259 markus 1519: static struct sshkey *
1.229 jcs 1520: load_identity_file(Identity *id)
1.51 markus 1521: {
1.259 markus 1522: struct sshkey *private = NULL;
1.229 jcs 1523: char prompt[300], *passphrase, *comment;
1.308 dtucker 1524: int r, quit = 0, i;
1.52 markus 1525: struct stat st;
1.16 markus 1526:
1.306 deraadt 1527: if (stat(id->filename, &st) == -1) {
1.330 djm 1528: do_log2(id->userprovided ?
1529: SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_DEBUG3,
1530: "no such identity: %s: %s", id->filename, strerror(errno));
1.52 markus 1531: return NULL;
1532: }
1.214 djm 1533: snprintf(prompt, sizeof prompt,
1.229 jcs 1534: "Enter passphrase for key '%.100s': ", id->filename);
1.214 djm 1535: for (i = 0; i <= options.number_of_password_prompts; i++) {
1536: if (i == 0)
1537: passphrase = "";
1538: else {
1.20 markus 1539: passphrase = read_passphrase(prompt, 0);
1.214 djm 1540: if (*passphrase == '\0') {
1.20 markus 1541: debug2("no passphrase given, try next key");
1.214 djm 1542: free(passphrase);
1543: break;
1544: }
1545: }
1.229 jcs 1546: switch ((r = sshkey_load_private_type(KEY_UNSPEC, id->filename,
1.308 dtucker 1547: passphrase, &private, &comment))) {
1.214 djm 1548: case 0:
1549: break;
1550: case SSH_ERR_KEY_WRONG_PASSPHRASE:
1551: if (options.batch_mode) {
1552: quit = 1;
1553: break;
1554: }
1.215 djm 1555: if (i != 0)
1556: debug2("bad passphrase given, try again...");
1.214 djm 1557: break;
1558: case SSH_ERR_SYSTEM_ERROR:
1559: if (errno == ENOENT) {
1.331 djm 1560: debug2_r(r, "Load key \"%s\"", id->filename);
1.51 markus 1561: quit = 1;
1.214 djm 1562: break;
1.20 markus 1563: }
1.214 djm 1564: /* FALLTHROUGH */
1565: default:
1.331 djm 1566: error_r(r, "Load key \"%s\"", id->filename);
1.214 djm 1567: quit = 1;
1568: break;
1569: }
1.311 markus 1570: if (private != NULL && sshkey_is_sk(private) &&
1.309 djm 1571: options.sk_provider == NULL) {
1.319 naddy 1572: debug("key \"%s\" is an authenticator-hosted key, "
1573: "but no provider specified", id->filename);
1.309 djm 1574: sshkey_free(private);
1575: private = NULL;
1576: quit = 1;
1577: }
1.361 djm 1578: if (!quit && (r = sshkey_check_rsa_length(private,
1579: options.required_rsa_size)) != 0) {
1580: debug_fr(r, "Skipping key %s", id->filename);
1581: sshkey_free(private);
1582: private = NULL;
1583: quit = 1;
1584: }
1.230 djm 1585: if (!quit && private != NULL && id->agent_fd == -1 &&
1.229 jcs 1586: !(id->key && id->isprivate))
1587: maybe_add_key_to_agent(id->filename, private, comment,
1588: passphrase);
1.278 markus 1589: if (i > 0)
1590: freezero(passphrase, strlen(passphrase));
1.232 mmcc 1591: free(comment);
1.214 djm 1592: if (private != NULL || quit)
1593: break;
1.16 markus 1594: }
1.51 markus 1595: return private;
1596: }
1597:
1.272 djm 1598: static int
1599: key_type_allowed_by_config(struct sshkey *key)
1600: {
1601: if (match_pattern_list(sshkey_ssh_name(key),
1.342 dtucker 1602: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1603: return 1;
1604:
1605: /* RSA keys/certs might be allowed by alternate signature types */
1606: switch (key->type) {
1607: case KEY_RSA:
1608: if (match_pattern_list("rsa-sha2-512",
1.342 dtucker 1609: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1610: return 1;
1611: if (match_pattern_list("rsa-sha2-256",
1.342 dtucker 1612: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1613: return 1;
1614: break;
1615: case KEY_RSA_CERT:
1616: if (match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
1.342 dtucker 1617: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1618: return 1;
1619: if (match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
1.342 dtucker 1620: options.pubkey_accepted_algos, 0) == 1)
1.272 djm 1621: return 1;
1622: break;
1623: }
1624: return 0;
1625: }
1626:
1.352 djm 1627: /* obtain a list of keys from the agent */
1628: static int
1629: get_agent_identities(struct ssh *ssh, int *agent_fdp,
1630: struct ssh_identitylist **idlistp)
1631: {
1632: int r, agent_fd;
1633: struct ssh_identitylist *idlist;
1634:
1635: if ((r = ssh_get_authentication_socket(&agent_fd)) != 0) {
1636: if (r != SSH_ERR_AGENT_NOT_PRESENT)
1637: debug_fr(r, "ssh_get_authentication_socket");
1638: return r;
1639: }
1640: if ((r = ssh_agent_bind_hostkey(agent_fd, ssh->kex->initial_hostkey,
1641: ssh->kex->session_id, ssh->kex->initial_sig, 0)) == 0)
1642: debug_f("bound agent to hostkey");
1643: else
1644: debug2_fr(r, "ssh_agent_bind_hostkey");
1645:
1646: if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
1647: debug_fr(r, "ssh_fetch_identitylist");
1648: close(agent_fd);
1649: return r;
1650: }
1651: /* success */
1652: *agent_fdp = agent_fd;
1653: *idlistp = idlist;
1654: debug_f("agent returned %zu keys", idlist->nkeys);
1655: return 0;
1656: }
1.272 djm 1657:
1.117 markus 1658: /*
1659: * try keys in the following order:
1.332 djm 1660: * 1. certificates listed in the config file
1661: * 2. other input certificates
1.227 djm 1662: * 3. agent keys that are found in the config file
1663: * 4. other agent keys
1664: * 5. keys that are only listed in the config file
1.117 markus 1665: */
1666: static void
1.352 djm 1667: pubkey_prepare(struct ssh *ssh, Authctxt *authctxt)
1.51 markus 1668: {
1.214 djm 1669: struct identity *id, *id2, *tmp;
1670: struct idlist agent, files, *preferred;
1671: struct sshkey *key;
1.230 djm 1672: int agent_fd = -1, i, r, found;
1.214 djm 1673: size_t j;
1674: struct ssh_identitylist *idlist;
1.287 djm 1675: char *ident;
1.51 markus 1676:
1.117 markus 1677: TAILQ_INIT(&agent); /* keys from the agent */
1678: TAILQ_INIT(&files); /* keys from the config file */
1679: preferred = &authctxt->keys;
1680: TAILQ_INIT(preferred); /* preferred order of keys */
1681:
1.190 djm 1682: /* list of keys stored in the filesystem and PKCS#11 */
1.117 markus 1683: for (i = 0; i < options.num_identity_files; i++) {
1684: key = options.identity_keys[i];
1.309 djm 1685: if (key && key->cert &&
1686: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1687: debug_f("ignoring certificate %s: not a user "
1688: "certificate", options.identity_files[i]);
1.309 djm 1689: continue;
1690: }
1.311 markus 1691: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1692: debug_f("ignoring authenticator-hosted key %s as no "
1.309 djm 1693: "SecurityKeyProvider has been specified",
1.331 djm 1694: options.identity_files[i]);
1.117 markus 1695: continue;
1.309 djm 1696: }
1.117 markus 1697: options.identity_keys[i] = NULL;
1.150 djm 1698: id = xcalloc(1, sizeof(*id));
1.230 djm 1699: id->agent_fd = -1;
1.117 markus 1700: id->key = key;
1701: id->filename = xstrdup(options.identity_files[i]);
1.192 dtucker 1702: id->userprovided = options.identity_file_userprovided[i];
1.117 markus 1703: TAILQ_INSERT_TAIL(&files, id, next);
1.190 djm 1704: }
1.227 djm 1705: /* list of certificates specified by user */
1706: for (i = 0; i < options.num_certificate_files; i++) {
1707: key = options.certificates[i];
1.278 markus 1708: if (!sshkey_is_cert(key) || key->cert == NULL ||
1.309 djm 1709: key->cert->type != SSH2_CERT_TYPE_USER) {
1.331 djm 1710: debug_f("ignoring certificate %s: not a user "
1711: "certificate", options.identity_files[i]);
1.227 djm 1712: continue;
1.309 djm 1713: }
1.311 markus 1714: if (key && sshkey_is_sk(key) && options.sk_provider == NULL) {
1.331 djm 1715: debug_f("ignoring authenticator-hosted key "
1.319 naddy 1716: "certificate %s as no "
1.309 djm 1717: "SecurityKeyProvider has been specified",
1.331 djm 1718: options.identity_files[i]);
1.309 djm 1719: continue;
1720: }
1.227 djm 1721: id = xcalloc(1, sizeof(*id));
1.230 djm 1722: id->agent_fd = -1;
1.227 djm 1723: id->key = key;
1724: id->filename = xstrdup(options.certificate_files[i]);
1725: id->userprovided = options.certificate_file_userprovided[i];
1726: TAILQ_INSERT_TAIL(preferred, id, next);
1.117 markus 1727: }
1728: /* list of keys supported by the agent */
1.352 djm 1729: if ((r = get_agent_identities(ssh, &agent_fd, &idlist)) == 0) {
1.214 djm 1730: for (j = 0; j < idlist->nkeys; j++) {
1.361 djm 1731: if ((r = sshkey_check_rsa_length(idlist->keys[j],
1732: options.required_rsa_size)) != 0) {
1733: debug_fr(r, "ignoring %s agent key",
1734: sshkey_ssh_name(idlist->keys[j]));
1735: continue;
1736: }
1.117 markus 1737: found = 0;
1738: TAILQ_FOREACH(id, &files, next) {
1.214 djm 1739: /*
1740: * agent keys from the config file are
1741: * preferred
1742: */
1743: if (sshkey_equal(idlist->keys[j], id->key)) {
1.117 markus 1744: TAILQ_REMOVE(&files, id, next);
1745: TAILQ_INSERT_TAIL(preferred, id, next);
1.214 djm 1746: id->agent_fd = agent_fd;
1.117 markus 1747: found = 1;
1748: break;
1749: }
1750: }
1.135 markus 1751: if (!found && !options.identities_only) {
1.150 djm 1752: id = xcalloc(1, sizeof(*id));
1.214 djm 1753: /* XXX "steals" key/comment from idlist */
1754: id->key = idlist->keys[j];
1755: id->filename = idlist->comments[j];
1756: idlist->keys[j] = NULL;
1757: idlist->comments[j] = NULL;
1758: id->agent_fd = agent_fd;
1.117 markus 1759: TAILQ_INSERT_TAIL(&agent, id, next);
1760: }
1761: }
1.214 djm 1762: ssh_free_identitylist(idlist);
1.117 markus 1763: /* append remaining agent keys */
1.324 bket 1764: TAILQ_CONCAT(preferred, &agent, next);
1.214 djm 1765: authctxt->agent_fd = agent_fd;
1.244 djm 1766: }
1767: /* Prefer PKCS11 keys that are explicitly listed */
1768: TAILQ_FOREACH_SAFE(id, &files, next, tmp) {
1769: if (id->key == NULL || (id->key->flags & SSHKEY_FLAG_EXT) == 0)
1770: continue;
1771: found = 0;
1772: TAILQ_FOREACH(id2, &files, next) {
1773: if (id2->key == NULL ||
1.321 djm 1774: (id2->key->flags & SSHKEY_FLAG_EXT) != 0)
1.244 djm 1775: continue;
1776: if (sshkey_equal(id->key, id2->key)) {
1777: TAILQ_REMOVE(&files, id, next);
1778: TAILQ_INSERT_TAIL(preferred, id, next);
1779: found = 1;
1780: break;
1781: }
1782: }
1783: /* If IdentitiesOnly set and key not found then don't use it */
1784: if (!found && options.identities_only) {
1785: TAILQ_REMOVE(&files, id, next);
1.278 markus 1786: freezero(id, sizeof(*id));
1.244 djm 1787: }
1.117 markus 1788: }
1789: /* append remaining keys from the config file */
1.324 bket 1790: TAILQ_CONCAT(preferred, &files, next);
1.342 dtucker 1791: /* finally, filter by PubkeyAcceptedAlgorithms */
1.228 djm 1792: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1.273 djm 1793: if (id->key != NULL && !key_type_allowed_by_config(id->key)) {
1.228 djm 1794: debug("Skipping %s key %s - "
1.342 dtucker 1795: "corresponding algo not in PubkeyAcceptedAlgorithms",
1.228 djm 1796: sshkey_ssh_name(id->key), id->filename);
1797: TAILQ_REMOVE(preferred, id, next);
1798: sshkey_free(id->key);
1799: free(id->filename);
1800: memset(id, 0, sizeof(*id));
1801: continue;
1802: }
1.117 markus 1803: }
1.287 djm 1804: /* List the keys we plan on using */
1805: TAILQ_FOREACH_SAFE(id, preferred, next, id2) {
1806: ident = format_identity(id);
1807: debug("Will attempt key: %s", ident);
1808: free(ident);
1809: }
1.331 djm 1810: debug2_f("done");
1.17 markus 1811: }
1812:
1.117 markus 1813: static void
1.303 djm 1814: pubkey_cleanup(struct ssh *ssh)
1.51 markus 1815: {
1.302 djm 1816: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1817: Identity *id;
1.51 markus 1818:
1.289 djm 1819: if (authctxt->agent_fd != -1) {
1.214 djm 1820: ssh_close_authentication_socket(authctxt->agent_fd);
1.289 djm 1821: authctxt->agent_fd = -1;
1822: }
1.117 markus 1823: for (id = TAILQ_FIRST(&authctxt->keys); id;
1824: id = TAILQ_FIRST(&authctxt->keys)) {
1825: TAILQ_REMOVE(&authctxt->keys, id, next);
1.235 mmcc 1826: sshkey_free(id->key);
1.197 djm 1827: free(id->filename);
1828: free(id);
1.117 markus 1829: }
1.1 markus 1830: }
1831:
1.251 djm 1832: static void
1833: pubkey_reset(Authctxt *authctxt)
1834: {
1835: Identity *id;
1836:
1837: TAILQ_FOREACH(id, &authctxt->keys, next)
1838: id->tried = 0;
1839: }
1840:
1.225 markus 1841: static int
1.295 djm 1842: userauth_pubkey(struct ssh *ssh)
1.20 markus 1843: {
1.295 djm 1844: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.117 markus 1845: Identity *id;
1.20 markus 1846: int sent = 0;
1.287 djm 1847: char *ident;
1.20 markus 1848:
1.117 markus 1849: while ((id = TAILQ_FIRST(&authctxt->keys))) {
1850: if (id->tried++)
1851: return (0);
1.127 markus 1852: /* move key to the end of the queue */
1.117 markus 1853: TAILQ_REMOVE(&authctxt->keys, id, next);
1854: TAILQ_INSERT_TAIL(&authctxt->keys, id, next);
1855: /*
1856: * send a test message if we have the public key. for
1857: * encrypted keys we cannot do this and have to load the
1858: * private key instead
1859: */
1.200 djm 1860: if (id->key != NULL) {
1.362 dtucker 1861: if (id->key != NULL) {
1.287 djm 1862: ident = format_identity(id);
1863: debug("Offering public key: %s", ident);
1864: free(ident);
1.295 djm 1865: sent = send_pubkey_test(ssh, id);
1.200 djm 1866: }
1867: } else {
1.117 markus 1868: debug("Trying private key: %s", id->filename);
1.229 jcs 1869: id->key = load_identity_file(id);
1.117 markus 1870: if (id->key != NULL) {
1.362 dtucker 1871: if (id->key != NULL) {
1.225 markus 1872: id->isprivate = 1;
1.295 djm 1873: sent = sign_and_send_pubkey(ssh, id);
1.200 djm 1874: }
1.278 markus 1875: sshkey_free(id->key);
1.117 markus 1876: id->key = NULL;
1.251 djm 1877: id->isprivate = 0;
1.51 markus 1878: }
1879: }
1.117 markus 1880: if (sent)
1881: return (sent);
1.28 markus 1882: }
1.117 markus 1883: return (0);
1.20 markus 1884: }
1885:
1.23 markus 1886: /*
1887: * Send userauth request message specifying keyboard-interactive method.
1888: */
1.302 djm 1889: static int
1.295 djm 1890: userauth_kbdint(struct ssh *ssh)
1.23 markus 1891: {
1.295 djm 1892: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.278 markus 1893: int r;
1.23 markus 1894:
1.292 djm 1895: if (authctxt->attempt_kbdint++ >= options.number_of_password_prompts)
1.23 markus 1896: return 0;
1.82 markus 1897: /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */
1.292 djm 1898: if (authctxt->attempt_kbdint > 1 && !authctxt->info_req_seen) {
1.82 markus 1899: debug3("userauth_kbdint: disable: no info_req_seen");
1.278 markus 1900: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, NULL);
1.82 markus 1901: return 0;
1902: }
1.23 markus 1903:
1904: debug2("userauth_kbdint");
1.278 markus 1905: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
1906: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
1907: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
1908: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1909: (r = sshpkt_put_cstring(ssh, "")) != 0 || /* lang */
1910: (r = sshpkt_put_cstring(ssh, options.kbd_interactive_devices ?
1911: options.kbd_interactive_devices : "")) != 0 ||
1912: (r = sshpkt_send(ssh)) != 0)
1.331 djm 1913: fatal_fr(r, "send packet");
1.23 markus 1914:
1.278 markus 1915: ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req);
1.23 markus 1916: return 1;
1917: }
1918:
1919: /*
1.46 markus 1920: * parse INFO_REQUEST, prompt user and send INFO_RESPONSE
1.23 markus 1921: */
1.302 djm 1922: static int
1.261 markus 1923: input_userauth_info_req(int type, u_int32_t seq, struct ssh *ssh)
1.23 markus 1924: {
1.260 markus 1925: Authctxt *authctxt = ssh->authctxt;
1.278 markus 1926: char *name = NULL, *inst = NULL, *lang = NULL, *prompt = NULL;
1.335 djm 1927: char *display_prompt = NULL, *response = NULL;
1.278 markus 1928: u_char echo = 0;
1.32 markus 1929: u_int num_prompts, i;
1.278 markus 1930: int r;
1.23 markus 1931:
1.335 djm 1932: debug2_f("entering");
1.23 markus 1933:
1934: if (authctxt == NULL)
1.335 djm 1935: fatal_f("no authentication context");
1.82 markus 1936:
1937: authctxt->info_req_seen = 1;
1.23 markus 1938:
1.278 markus 1939: if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
1940: (r = sshpkt_get_cstring(ssh, &inst, NULL)) != 0 ||
1941: (r = sshpkt_get_cstring(ssh, &lang, NULL)) != 0)
1942: goto out;
1.23 markus 1943: if (strlen(name) > 0)
1.116 itojun 1944: logit("%s", name);
1.23 markus 1945: if (strlen(inst) > 0)
1.116 itojun 1946: logit("%s", inst);
1.23 markus 1947:
1.278 markus 1948: if ((r = sshpkt_get_u32(ssh, &num_prompts)) != 0)
1949: goto out;
1.23 markus 1950: /*
1951: * Begin to build info response packet based on prompts requested.
1952: * We commit to providing the correct number of responses, so if
1953: * further on we run into a problem that prevents this, we have to
1954: * be sure and clean this up and send a correct error response.
1955: */
1.278 markus 1956: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_INFO_RESPONSE)) != 0 ||
1957: (r = sshpkt_put_u32(ssh, num_prompts)) != 0)
1958: goto out;
1.23 markus 1959:
1.335 djm 1960: debug2_f("num_prompts %d", num_prompts);
1.23 markus 1961: for (i = 0; i < num_prompts; i++) {
1.278 markus 1962: if ((r = sshpkt_get_cstring(ssh, &prompt, NULL)) != 0 ||
1963: (r = sshpkt_get_u8(ssh, &echo)) != 0)
1964: goto out;
1.336 djm 1965: if (asmprintf(&display_prompt, INT_MAX, NULL, "(%s@%s) %s",
1.335 djm 1966: authctxt->server_user, options.host_key_alias ?
1.336 djm 1967: options.host_key_alias : authctxt->host, prompt) == -1)
1968: fatal_f("asmprintf failed");
1.335 djm 1969: response = read_passphrase(display_prompt, echo ? RP_ECHO : 0);
1.278 markus 1970: if ((r = sshpkt_put_cstring(ssh, response)) != 0)
1971: goto out;
1972: freezero(response, strlen(response));
1.197 djm 1973: free(prompt);
1.335 djm 1974: free(display_prompt);
1975: display_prompt = response = prompt = NULL;
1.23 markus 1976: }
1.278 markus 1977: /* done with parsing incoming message. */
1978: if ((r = sshpkt_get_end(ssh)) != 0 ||
1979: (r = sshpkt_add_padding(ssh, 64)) != 0)
1980: goto out;
1981: r = sshpkt_send(ssh);
1982: out:
1983: if (response)
1984: freezero(response, strlen(response));
1985: free(prompt);
1.335 djm 1986: free(display_prompt);
1.278 markus 1987: free(name);
1988: free(inst);
1989: free(lang);
1990: return r;
1.68 markus 1991: }
1992:
1.100 markus 1993: static int
1.294 djm 1994: ssh_keysign(struct ssh *ssh, struct sshkey *key, u_char **sigp, size_t *lenp,
1.223 djm 1995: const u_char *data, size_t datalen)
1.100 markus 1996: {
1.223 djm 1997: struct sshbuf *b;
1.101 markus 1998: struct stat st;
1.100 markus 1999: pid_t pid;
1.304 deraadt 2000: int r, to[2], from[2], status;
1.295 djm 2001: int sock = ssh_packet_get_connection_in(ssh);
1.223 djm 2002: u_char rversion = 0, version = 2;
2003: void (*osigchld)(int);
1.100 markus 2004:
1.223 djm 2005: *sigp = NULL;
2006: *lenp = 0;
1.100 markus 2007:
1.306 deraadt 2008: if (stat(_PATH_SSH_KEY_SIGN, &st) == -1) {
1.331 djm 2009: error_f("not installed: %s", strerror(errno));
1.223 djm 2010: return -1;
2011: }
2012: if (fflush(stdout) != 0) {
1.331 djm 2013: error_f("fflush: %s", strerror(errno));
1.101 markus 2014: return -1;
2015: }
1.306 deraadt 2016: if (pipe(to) == -1) {
1.331 djm 2017: error_f("pipe: %s", strerror(errno));
1.100 markus 2018: return -1;
2019: }
1.306 deraadt 2020: if (pipe(from) == -1) {
1.331 djm 2021: error_f("pipe: %s", strerror(errno));
1.100 markus 2022: return -1;
2023: }
1.306 deraadt 2024: if ((pid = fork()) == -1) {
1.331 djm 2025: error_f("fork: %s", strerror(errno));
1.100 markus 2026: return -1;
2027: }
1.317 dtucker 2028: osigchld = ssh_signal(SIGCHLD, SIG_DFL);
1.100 markus 2029: if (pid == 0) {
2030: close(from[0]);
1.306 deraadt 2031: if (dup2(from[1], STDOUT_FILENO) == -1)
1.331 djm 2032: fatal_f("dup2: %s", strerror(errno));
1.100 markus 2033: close(to[1]);
1.306 deraadt 2034: if (dup2(to[0], STDIN_FILENO) == -1)
1.331 djm 2035: fatal_f("dup2: %s", strerror(errno));
1.103 markus 2036: close(from[1]);
2037: close(to[0]);
1.304 deraadt 2038:
1.306 deraadt 2039: if (dup2(sock, STDERR_FILENO + 1) == -1)
1.331 djm 2040: fatal_f("dup2: %s", strerror(errno));
1.304 deraadt 2041: sock = STDERR_FILENO + 1;
1.363 dtucker 2042: if (fcntl(sock, F_SETFD, 0) == -1) /* keep the socket on exec */
2043: debug3_f("fcntl F_SETFD: %s", strerror(errno));
1.223 djm 2044: closefrom(sock + 1);
1.304 deraadt 2045:
1.331 djm 2046: debug3_f("[child] pid=%ld, exec %s",
2047: (long)getpid(), _PATH_SSH_KEY_SIGN);
1.233 mmcc 2048: execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *)NULL);
1.331 djm 2049: fatal_f("exec(%s): %s", _PATH_SSH_KEY_SIGN,
1.100 markus 2050: strerror(errno));
2051: }
2052: close(from[1]);
2053: close(to[0]);
1.305 djm 2054: sock = STDERR_FILENO + 1;
1.100 markus 2055:
1.223 djm 2056: if ((b = sshbuf_new()) == NULL)
1.331 djm 2057: fatal_f("sshbuf_new failed");
1.223 djm 2058: /* send # of sock, data to be signed */
1.253 djm 2059: if ((r = sshbuf_put_u32(b, sock)) != 0 ||
1.223 djm 2060: (r = sshbuf_put_string(b, data, datalen)) != 0)
1.331 djm 2061: fatal_fr(r, "buffer error");
1.223 djm 2062: if (ssh_msg_send(to[1], version, b) == -1)
1.331 djm 2063: fatal_f("couldn't send request");
1.223 djm 2064: sshbuf_reset(b);
2065: r = ssh_msg_recv(from[0], b);
1.101 markus 2066: close(from[0]);
2067: close(to[1]);
1.223 djm 2068: if (r < 0) {
1.331 djm 2069: error_f("no reply");
1.223 djm 2070: goto fail;
2071: }
1.101 markus 2072:
1.223 djm 2073: errno = 0;
1.306 deraadt 2074: while (waitpid(pid, &status, 0) == -1) {
1.223 djm 2075: if (errno != EINTR) {
1.331 djm 2076: error_f("waitpid %ld: %s", (long)pid, strerror(errno));
1.223 djm 2077: goto fail;
2078: }
2079: }
2080: if (!WIFEXITED(status)) {
1.331 djm 2081: error_f("exited abnormally");
1.223 djm 2082: goto fail;
2083: }
2084: if (WEXITSTATUS(status) != 0) {
1.331 djm 2085: error_f("exited with status %d", WEXITSTATUS(status));
1.223 djm 2086: goto fail;
2087: }
2088: if ((r = sshbuf_get_u8(b, &rversion)) != 0) {
1.331 djm 2089: error_fr(r, "buffer error");
1.223 djm 2090: goto fail;
2091: }
2092: if (rversion != version) {
1.331 djm 2093: error_f("bad version");
1.223 djm 2094: goto fail;
2095: }
2096: if ((r = sshbuf_get_string(b, sigp, lenp)) != 0) {
1.331 djm 2097: error_fr(r, "buffer error");
1.223 djm 2098: fail:
1.317 dtucker 2099: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2100: sshbuf_free(b);
1.100 markus 2101: return -1;
2102: }
1.317 dtucker 2103: ssh_signal(SIGCHLD, osigchld);
1.223 djm 2104: sshbuf_free(b);
1.100 markus 2105:
2106: return 0;
2107: }
2108:
1.302 djm 2109: static int
1.295 djm 2110: userauth_hostbased(struct ssh *ssh)
1.68 markus 2111: {
1.295 djm 2112: Authctxt *authctxt = (Authctxt *)ssh->authctxt;
1.223 djm 2113: struct sshkey *private = NULL;
2114: struct sshbuf *b = NULL;
2115: u_char *sig = NULL, *keyblob = NULL;
2116: char *fp = NULL, *chost = NULL, *lname = NULL;
2117: size_t siglen = 0, keylen = 0;
2118: int i, r, success = 0;
2119:
2120: if (authctxt->ktypes == NULL) {
1.344 dtucker 2121: authctxt->oktypes = xstrdup(options.hostbased_accepted_algos);
1.223 djm 2122: authctxt->ktypes = authctxt->oktypes;
2123: }
1.213 djm 2124:
1.223 djm 2125: /*
1.344 dtucker 2126: * Work through each listed type pattern in HostbasedAcceptedAlgorithms,
1.223 djm 2127: * trying each hostkey that matches the type in turn.
2128: */
2129: for (;;) {
2130: if (authctxt->active_ktype == NULL)
2131: authctxt->active_ktype = strsep(&authctxt->ktypes, ",");
2132: if (authctxt->active_ktype == NULL ||
2133: *authctxt->active_ktype == '\0')
2134: break;
1.331 djm 2135: debug3_f("trying key type %s", authctxt->active_ktype);
1.68 markus 2136:
1.223 djm 2137: /* check for a useful key */
2138: private = NULL;
2139: for (i = 0; i < authctxt->sensitive->nkeys; i++) {
2140: if (authctxt->sensitive->keys[i] == NULL ||
2141: authctxt->sensitive->keys[i]->type == KEY_UNSPEC)
2142: continue;
1.355 djm 2143: if (!sshkey_match_keyname_to_sigalgs(
1.223 djm 2144: sshkey_ssh_name(authctxt->sensitive->keys[i]),
1.355 djm 2145: authctxt->active_ktype))
1.223 djm 2146: continue;
1.68 markus 2147: /* we take and free the key */
1.223 djm 2148: private = authctxt->sensitive->keys[i];
2149: authctxt->sensitive->keys[i] = NULL;
1.68 markus 2150: break;
2151: }
1.223 djm 2152: /* Found one */
2153: if (private != NULL)
2154: break;
2155: /* No more keys of this type; advance */
2156: authctxt->active_ktype = NULL;
1.68 markus 2157: }
1.223 djm 2158: if (private == NULL) {
2159: free(authctxt->oktypes);
2160: authctxt->oktypes = authctxt->ktypes = NULL;
2161: authctxt->active_ktype = NULL;
1.109 markus 2162: debug("No more client hostkeys for hostbased authentication.");
1.223 djm 2163: goto out;
1.68 markus 2164: }
1.211 djm 2165:
1.223 djm 2166: if ((fp = sshkey_fingerprint(private, options.fingerprint_hash,
2167: SSH_FP_DEFAULT)) == NULL) {
1.331 djm 2168: error_f("sshkey_fingerprint failed");
1.223 djm 2169: goto out;
1.68 markus 2170: }
1.355 djm 2171: debug_f("trying hostkey %s %s using sigalg %s",
2172: sshkey_ssh_name(private), fp, authctxt->active_ktype);
1.211 djm 2173:
1.84 markus 2174: /* figure out a name for the client host */
1.295 djm 2175: lname = get_local_name(ssh_packet_get_connection_in(ssh));
2176: if (lname == NULL) {
1.331 djm 2177: error_f("cannot get local ipaddr/name");
1.223 djm 2178: goto out;
1.84 markus 2179: }
1.223 djm 2180:
2181: /* XXX sshbuf_put_stringf? */
2182: xasprintf(&chost, "%s.", lname);
1.331 djm 2183: debug2_f("chost %s", chost);
1.84 markus 2184:
1.68 markus 2185: /* construct data */
1.223 djm 2186: if ((b = sshbuf_new()) == NULL) {
1.331 djm 2187: error_f("sshbuf_new failed");
1.223 djm 2188: goto out;
2189: }
2190: if ((r = sshkey_to_blob(private, &keyblob, &keylen)) != 0) {
1.331 djm 2191: error_fr(r, "sshkey_to_blob");
1.223 djm 2192: goto out;
2193: }
1.346 djm 2194: if ((r = sshbuf_put_stringb(b, ssh->kex->session_id)) != 0 ||
1.223 djm 2195: (r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2196: (r = sshbuf_put_cstring(b, authctxt->server_user)) != 0 ||
1.267 djm 2197: (r = sshbuf_put_cstring(b, authctxt->service)) != 0 ||
1.223 djm 2198: (r = sshbuf_put_cstring(b, authctxt->method->name)) != 0 ||
1.343 djm 2199: (r = sshbuf_put_cstring(b, authctxt->active_ktype)) != 0 ||
1.223 djm 2200: (r = sshbuf_put_string(b, keyblob, keylen)) != 0 ||
2201: (r = sshbuf_put_cstring(b, chost)) != 0 ||
2202: (r = sshbuf_put_cstring(b, authctxt->local_user)) != 0) {
1.331 djm 2203: error_fr(r, "buffer error");
1.223 djm 2204: goto out;
2205: }
2206:
1.68 markus 2207: #ifdef DEBUG_PK
1.223 djm 2208: sshbuf_dump(b, stderr);
1.68 markus 2209: #endif
1.294 djm 2210: if ((r = ssh_keysign(ssh, private, &sig, &siglen,
2211: sshbuf_ptr(b), sshbuf_len(b))) != 0) {
1.223 djm 2212: error("sign using hostkey %s %s failed",
2213: sshkey_ssh_name(private), fp);
2214: goto out;
2215: }
2216: if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
2217: (r = sshpkt_put_cstring(ssh, authctxt->server_user)) != 0 ||
2218: (r = sshpkt_put_cstring(ssh, authctxt->service)) != 0 ||
2219: (r = sshpkt_put_cstring(ssh, authctxt->method->name)) != 0 ||
1.343 djm 2220: (r = sshpkt_put_cstring(ssh, authctxt->active_ktype)) != 0 ||
1.223 djm 2221: (r = sshpkt_put_string(ssh, keyblob, keylen)) != 0 ||
2222: (r = sshpkt_put_cstring(ssh, chost)) != 0 ||
2223: (r = sshpkt_put_cstring(ssh, authctxt->local_user)) != 0 ||
2224: (r = sshpkt_put_string(ssh, sig, siglen)) != 0 ||
2225: (r = sshpkt_send(ssh)) != 0) {
1.331 djm 2226: error_fr(r, "packet error");
1.223 djm 2227: goto out;
2228: }
2229: success = 1;
2230:
2231: out:
1.278 markus 2232: if (sig != NULL)
2233: freezero(sig, siglen);
1.223 djm 2234: free(keyblob);
2235: free(lname);
2236: free(fp);
1.197 djm 2237: free(chost);
1.223 djm 2238: sshkey_free(private);
2239: sshbuf_free(b);
1.68 markus 2240:
1.223 djm 2241: return success;
1.23 markus 2242: }
1.170 djm 2243:
1.20 markus 2244: /* find auth method */
2245:
2246: /*
2247: * given auth method name, if configurable options permit this method fill
2248: * in auth_ident field and return true, otherwise return false.
2249: */
1.76 itojun 2250: static int
1.20 markus 2251: authmethod_is_enabled(Authmethod *method)
2252: {
2253: if (method == NULL)
2254: return 0;
2255: /* return false if options indicate this method is disabled */
2256: if (method->enabled == NULL || *method->enabled == 0)
2257: return 0;
2258: /* return false if batch mode is enabled but method needs interactive mode */
2259: if (method->batch_flag != NULL && *method->batch_flag != 0)
2260: return 0;
2261: return 1;
2262: }
2263:
1.76 itojun 2264: static Authmethod *
1.20 markus 2265: authmethod_lookup(const char *name)
1.1 markus 2266: {
1.20 markus 2267: Authmethod *method = NULL;
2268: if (name != NULL)
2269: for (method = authmethods; method->name != NULL; method++)
2270: if (strcmp(name, method->name) == 0)
2271: return method;
2272: debug2("Unrecognized authentication method name: %s", name ? name : "NULL");
2273: return NULL;
2274: }
1.1 markus 2275:
1.53 markus 2276: /* XXX internal state */
2277: static Authmethod *current = NULL;
2278: static char *supported = NULL;
2279: static char *preferred = NULL;
1.105 deraadt 2280:
1.20 markus 2281: /*
2282: * Given the authentication method list sent by the server, return the
2283: * next method we should try. If the server initially sends a nil list,
1.67 markus 2284: * use a built-in default list.
1.41 stevesk 2285: */
1.76 itojun 2286: static Authmethod *
1.20 markus 2287: authmethod_get(char *authlist)
2288: {
1.53 markus 2289: char *name = NULL;
1.97 markus 2290: u_int next;
1.41 stevesk 2291:
1.20 markus 2292: /* Use a suitable default if we're passed a nil list. */
2293: if (authlist == NULL || strlen(authlist) == 0)
1.53 markus 2294: authlist = options.preferred_authentications;
1.20 markus 2295:
1.53 markus 2296: if (supported == NULL || strcmp(authlist, supported) != 0) {
2297: debug3("start over, passed a different list %s", authlist);
1.197 djm 2298: free(supported);
1.53 markus 2299: supported = xstrdup(authlist);
2300: preferred = options.preferred_authentications;
2301: debug3("preferred %s", preferred);
2302: current = NULL;
2303: } else if (current != NULL && authmethod_is_enabled(current))
2304: return current;
1.20 markus 2305:
1.53 markus 2306: for (;;) {
2307: if ((name = match_list(preferred, supported, &next)) == NULL) {
1.109 markus 2308: debug("No more authentication methods to try.");
1.53 markus 2309: current = NULL;
2310: return NULL;
2311: }
2312: preferred += next;
1.23 markus 2313: debug3("authmethod_lookup %s", name);
1.53 markus 2314: debug3("remaining preferred: %s", preferred);
2315: if ((current = authmethod_lookup(name)) != NULL &&
2316: authmethod_is_enabled(current)) {
1.23 markus 2317: debug3("authmethod_is_enabled %s", name);
1.109 markus 2318: debug("Next authentication method: %s", name);
1.197 djm 2319: free(name);
1.53 markus 2320: return current;
1.23 markus 2321: }
1.198 dtucker 2322: free(name);
1.1 markus 2323: }
1.53 markus 2324: }
1.1 markus 2325:
1.79 stevesk 2326: static char *
1.53 markus 2327: authmethods_get(void)
2328: {
2329: Authmethod *method = NULL;
1.278 markus 2330: struct sshbuf *b;
1.93 markus 2331: char *list;
1.278 markus 2332: int r;
1.27 provos 2333:
1.278 markus 2334: if ((b = sshbuf_new()) == NULL)
1.331 djm 2335: fatal_f("sshbuf_new failed");
1.53 markus 2336: for (method = authmethods; method->name != NULL; method++) {
2337: if (authmethod_is_enabled(method)) {
1.278 markus 2338: if ((r = sshbuf_putf(b, "%s%s",
2339: sshbuf_len(b) ? "," : "", method->name)) != 0)
1.331 djm 2340: fatal_fr(r, "buffer error");
1.53 markus 2341: }
2342: }
1.278 markus 2343: if ((list = sshbuf_dup_string(b)) == NULL)
1.331 djm 2344: fatal_f("sshbuf_dup_string failed");
1.278 markus 2345: sshbuf_free(b);
1.93 markus 2346: return list;
1.1 markus 2347: }
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