1296781Sdes/* $OpenBSD: auth2-pubkey.c,v 1.55 2016/01/27 00:53:12 djm Exp $ */ 298675Sdes/* 398675Sdes * Copyright (c) 2000 Markus Friedl. All rights reserved. 498675Sdes * 598675Sdes * Redistribution and use in source and binary forms, with or without 698675Sdes * modification, are permitted provided that the following conditions 798675Sdes * are met: 898675Sdes * 1. Redistributions of source code must retain the above copyright 998675Sdes * notice, this list of conditions and the following disclaimer. 1098675Sdes * 2. Redistributions in binary form must reproduce the above copyright 1198675Sdes * notice, this list of conditions and the following disclaimer in the 1298675Sdes * documentation and/or other materials provided with the distribution. 1398675Sdes * 1498675Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1598675Sdes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1698675Sdes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1798675Sdes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1898675Sdes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1998675Sdes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2098675Sdes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2198675Sdes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2298675Sdes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2398675Sdes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2498675Sdes */ 2598675Sdes 2698675Sdes#include "includes.h" 2798675Sdes 28162852Sdes#include <sys/types.h> 29162852Sdes#include <sys/stat.h> 30248619Sdes#include <sys/wait.h> 31162852Sdes 32248619Sdes#include <errno.h> 33181111Sdes#include <fcntl.h> 34248619Sdes#ifdef HAVE_PATHS_H 35248619Sdes# include <paths.h> 36248619Sdes#endif 37162852Sdes#include <pwd.h> 38248619Sdes#include <signal.h> 39162852Sdes#include <stdio.h> 40162852Sdes#include <stdarg.h> 41204917Sdes#include <string.h> 42204917Sdes#include <time.h> 43181111Sdes#include <unistd.h> 44295367Sdes#include <limits.h> 45162852Sdes 46162852Sdes#include "xmalloc.h" 47146998Sdes#include "ssh.h" 4898675Sdes#include "ssh2.h" 4998675Sdes#include "packet.h" 5098675Sdes#include "buffer.h" 5198675Sdes#include "log.h" 52295367Sdes#include "misc.h" 5398675Sdes#include "servconf.h" 5498675Sdes#include "compat.h" 55162852Sdes#include "key.h" 56162852Sdes#include "hostfile.h" 5798675Sdes#include "auth.h" 5898675Sdes#include "pathnames.h" 5998675Sdes#include "uidswap.h" 6098675Sdes#include "auth-options.h" 6198675Sdes#include "canohost.h" 62162852Sdes#ifdef GSSAPI 63162852Sdes#include "ssh-gss.h" 64162852Sdes#endif 6598675Sdes#include "monitor_wrap.h" 66204917Sdes#include "authfile.h" 67215116Sdes#include "match.h" 68295367Sdes#include "ssherr.h" 69295367Sdes#include "channels.h" /* XXX for session.h */ 70295367Sdes#include "session.h" /* XXX for child_set_env(); refactor? */ 7198675Sdes 7298675Sdes/* import */ 7398675Sdesextern ServerOptions options; 7498675Sdesextern u_char *session_id2; 75124208Sdesextern u_int session_id2_len; 7698675Sdes 7798675Sdesstatic int 7898675Sdesuserauth_pubkey(Authctxt *authctxt) 7998675Sdes{ 8098675Sdes Buffer b; 8198675Sdes Key *key = NULL; 82296781Sdes char *pkalg, *userstyle, *fp = NULL; 8398675Sdes u_char *pkblob, *sig; 8498675Sdes u_int alen, blen, slen; 8598675Sdes int have_sig, pktype; 8698675Sdes int authenticated = 0; 8798675Sdes 8898675Sdes if (!authctxt->valid) { 89296781Sdes debug2("%s: disabled because of invalid user", __func__); 9098675Sdes return 0; 9198675Sdes } 9298675Sdes have_sig = packet_get_char(); 9398675Sdes if (datafellows & SSH_BUG_PKAUTH) { 94296781Sdes debug2("%s: SSH_BUG_PKAUTH", __func__); 9598675Sdes /* no explicit pkalg given */ 9698675Sdes pkblob = packet_get_string(&blen); 9798675Sdes buffer_init(&b); 9898675Sdes buffer_append(&b, pkblob, blen); 9998675Sdes /* so we have to extract the pkalg from the pkblob */ 10098675Sdes pkalg = buffer_get_string(&b, &alen); 10198675Sdes buffer_free(&b); 10298675Sdes } else { 10398675Sdes pkalg = packet_get_string(&alen); 10498675Sdes pkblob = packet_get_string(&blen); 10598675Sdes } 10698675Sdes pktype = key_type_from_name(pkalg); 10798675Sdes if (pktype == KEY_UNSPEC) { 10898675Sdes /* this is perfectly legal */ 109296781Sdes logit("%s: unsupported public key algorithm: %s", 110296781Sdes __func__, pkalg); 11198675Sdes goto done; 11298675Sdes } 11398675Sdes key = key_from_blob(pkblob, blen); 11498675Sdes if (key == NULL) { 115296781Sdes error("%s: cannot decode key: %s", __func__, pkalg); 11698675Sdes goto done; 11798675Sdes } 11898675Sdes if (key->type != pktype) { 119296781Sdes error("%s: type mismatch for decoded key " 120296781Sdes "(received %d, expected %d)", __func__, key->type, pktype); 12198675Sdes goto done; 12298675Sdes } 123262566Sdes if (key_type_plain(key->type) == KEY_RSA && 124262566Sdes (datafellows & SSH_BUG_RSASIGMD5) != 0) { 125262566Sdes logit("Refusing RSA key because client uses unsafe " 126262566Sdes "signature scheme"); 127262566Sdes goto done; 128262566Sdes } 129296781Sdes fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_DEFAULT); 130295367Sdes if (auth2_userkey_already_used(authctxt, key)) { 131295367Sdes logit("refusing previously-used %s key", key_type(key)); 132295367Sdes goto done; 133295367Sdes } 134295367Sdes if (match_pattern_list(sshkey_ssh_name(key), 135295367Sdes options.pubkey_key_types, 0) != 1) { 136295367Sdes logit("%s: key type %s not in PubkeyAcceptedKeyTypes", 137295367Sdes __func__, sshkey_ssh_name(key)); 138295367Sdes goto done; 139295367Sdes } 140295367Sdes 14198675Sdes if (have_sig) { 142296781Sdes debug3("%s: have signature for %s %s", 143296781Sdes __func__, sshkey_type(key), fp); 14498675Sdes sig = packet_get_string(&slen); 14598675Sdes packet_check_eom(); 14698675Sdes buffer_init(&b); 14798675Sdes if (datafellows & SSH_OLD_SESSIONID) { 14898675Sdes buffer_append(&b, session_id2, session_id2_len); 14998675Sdes } else { 15098675Sdes buffer_put_string(&b, session_id2, session_id2_len); 15198675Sdes } 15298675Sdes /* reconstruct packet */ 15398675Sdes buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); 154255767Sdes xasprintf(&userstyle, "%s%s%s", authctxt->user, 155255767Sdes authctxt->style ? ":" : "", 156255767Sdes authctxt->style ? authctxt->style : ""); 157255767Sdes buffer_put_cstring(&b, userstyle); 158255767Sdes free(userstyle); 15998675Sdes buffer_put_cstring(&b, 16098675Sdes datafellows & SSH_BUG_PKSERVICE ? 16198675Sdes "ssh-userauth" : 16298675Sdes authctxt->service); 16398675Sdes if (datafellows & SSH_BUG_PKAUTH) { 16498675Sdes buffer_put_char(&b, have_sig); 16598675Sdes } else { 16698675Sdes buffer_put_cstring(&b, "publickey"); 16798675Sdes buffer_put_char(&b, have_sig); 16898675Sdes buffer_put_cstring(&b, pkalg); 16998675Sdes } 17098675Sdes buffer_put_string(&b, pkblob, blen); 17198675Sdes#ifdef DEBUG_PK 17298675Sdes buffer_dump(&b); 17398675Sdes#endif 174255767Sdes pubkey_auth_info(authctxt, key, NULL); 175255767Sdes 17698675Sdes /* test for correct signature */ 17798675Sdes authenticated = 0; 178295367Sdes if (PRIVSEP(user_key_allowed(authctxt->pw, key, 1)) && 17998675Sdes PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b), 180295367Sdes buffer_len(&b))) == 1) { 18198675Sdes authenticated = 1; 182295367Sdes /* Record the successful key to prevent reuse */ 183295367Sdes auth2_record_userkey(authctxt, key); 184295367Sdes key = NULL; /* Don't free below */ 185295367Sdes } 186126274Sdes buffer_free(&b); 187255767Sdes free(sig); 18898675Sdes } else { 189296781Sdes debug("%s: test whether pkalg/pkblob are acceptable for %s %s", 190296781Sdes __func__, sshkey_type(key), fp); 19198675Sdes packet_check_eom(); 19298675Sdes 19398675Sdes /* XXX fake reply and always send PK_OK ? */ 19498675Sdes /* 19598675Sdes * XXX this allows testing whether a user is allowed 19698675Sdes * to login: if you happen to have a valid pubkey this 19798675Sdes * message is sent. the message is NEVER sent at all 19898675Sdes * if a user is not allowed to login. is this an 19998675Sdes * issue? -markus 20098675Sdes */ 201295367Sdes if (PRIVSEP(user_key_allowed(authctxt->pw, key, 0))) { 20298675Sdes packet_start(SSH2_MSG_USERAUTH_PK_OK); 20398675Sdes packet_put_string(pkalg, alen); 20498675Sdes packet_put_string(pkblob, blen); 20598675Sdes packet_send(); 20698675Sdes packet_write_wait(); 20798675Sdes authctxt->postponed = 1; 20898675Sdes } 20998675Sdes } 21098675Sdes if (authenticated != 1) 21198675Sdes auth_clear_options(); 21298675Sdesdone: 213296781Sdes debug2("%s: authenticated %d pkalg %s", __func__, authenticated, pkalg); 21498675Sdes if (key != NULL) 21598675Sdes key_free(key); 216255767Sdes free(pkalg); 217255767Sdes free(pkblob); 218296781Sdes free(fp); 21998675Sdes return authenticated; 22098675Sdes} 22198675Sdes 222255767Sdesvoid 223255767Sdespubkey_auth_info(Authctxt *authctxt, const Key *key, const char *fmt, ...) 224255767Sdes{ 225255767Sdes char *fp, *extra; 226255767Sdes va_list ap; 227255767Sdes int i; 228255767Sdes 229255767Sdes extra = NULL; 230255767Sdes if (fmt != NULL) { 231255767Sdes va_start(ap, fmt); 232255767Sdes i = vasprintf(&extra, fmt, ap); 233255767Sdes va_end(ap); 234255767Sdes if (i < 0 || extra == NULL) 235255767Sdes fatal("%s: vasprintf failed", __func__); 236255767Sdes } 237255767Sdes 238255767Sdes if (key_is_cert(key)) { 239295367Sdes fp = sshkey_fingerprint(key->cert->signature_key, 240295367Sdes options.fingerprint_hash, SSH_FP_DEFAULT); 241255767Sdes auth_info(authctxt, "%s ID %s (serial %llu) CA %s %s%s%s", 242255767Sdes key_type(key), key->cert->key_id, 243255767Sdes (unsigned long long)key->cert->serial, 244295367Sdes key_type(key->cert->signature_key), 245295367Sdes fp == NULL ? "(null)" : fp, 246255767Sdes extra == NULL ? "" : ", ", extra == NULL ? "" : extra); 247255767Sdes free(fp); 248255767Sdes } else { 249295367Sdes fp = sshkey_fingerprint(key, options.fingerprint_hash, 250295367Sdes SSH_FP_DEFAULT); 251295367Sdes auth_info(authctxt, "%s %s%s%s", key_type(key), 252295367Sdes fp == NULL ? "(null)" : fp, 253255767Sdes extra == NULL ? "" : ", ", extra == NULL ? "" : extra); 254255767Sdes free(fp); 255255767Sdes } 256255767Sdes free(extra); 257255767Sdes} 258255767Sdes 259295367Sdes/* 260295367Sdes * Splits 's' into an argument vector. Handles quoted string and basic 261295367Sdes * escape characters (\\, \", \'). Caller must free the argument vector 262295367Sdes * and its members. 263295367Sdes */ 264215116Sdesstatic int 265295367Sdessplit_argv(const char *s, int *argcp, char ***argvp) 266215116Sdes{ 267295367Sdes int r = SSH_ERR_INTERNAL_ERROR; 268295367Sdes int argc = 0, quote, i, j; 269295367Sdes char *arg, **argv = xcalloc(1, sizeof(*argv)); 270295367Sdes 271295367Sdes *argvp = NULL; 272295367Sdes *argcp = 0; 273295367Sdes 274295367Sdes for (i = 0; s[i] != '\0'; i++) { 275295367Sdes /* Skip leading whitespace */ 276295367Sdes if (s[i] == ' ' || s[i] == '\t') 277295367Sdes continue; 278295367Sdes 279295367Sdes /* Start of a token */ 280295367Sdes quote = 0; 281295367Sdes if (s[i] == '\\' && 282295367Sdes (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\')) 283295367Sdes i++; 284295367Sdes else if (s[i] == '\'' || s[i] == '"') 285295367Sdes quote = s[i++]; 286295367Sdes 287295367Sdes argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 288295367Sdes arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 289295367Sdes argv[argc] = NULL; 290295367Sdes 291295367Sdes /* Copy the token in, removing escapes */ 292295367Sdes for (j = 0; s[i] != '\0'; i++) { 293295367Sdes if (s[i] == '\\') { 294295367Sdes if (s[i + 1] == '\'' || 295295367Sdes s[i + 1] == '\"' || 296295367Sdes s[i + 1] == '\\') { 297295367Sdes i++; /* Skip '\' */ 298295367Sdes arg[j++] = s[i]; 299295367Sdes } else { 300295367Sdes /* Unrecognised escape */ 301295367Sdes arg[j++] = s[i]; 302295367Sdes } 303295367Sdes } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 304295367Sdes break; /* done */ 305295367Sdes else if (quote != 0 && s[i] == quote) 306295367Sdes break; /* done */ 307295367Sdes else 308295367Sdes arg[j++] = s[i]; 309295367Sdes } 310295367Sdes if (s[i] == '\0') { 311295367Sdes if (quote != 0) { 312295367Sdes /* Ran out of string looking for close quote */ 313295367Sdes r = SSH_ERR_INVALID_FORMAT; 314295367Sdes goto out; 315295367Sdes } 316295367Sdes break; 317295367Sdes } 318295367Sdes } 319295367Sdes /* Success */ 320295367Sdes *argcp = argc; 321295367Sdes *argvp = argv; 322295367Sdes argc = 0; 323295367Sdes argv = NULL; 324295367Sdes r = 0; 325295367Sdes out: 326295367Sdes if (argc != 0 && argv != NULL) { 327295367Sdes for (i = 0; i < argc; i++) 328295367Sdes free(argv[i]); 329295367Sdes free(argv); 330295367Sdes } 331295367Sdes return r; 332295367Sdes} 333295367Sdes 334295367Sdes/* 335295367Sdes * Reassemble an argument vector into a string, quoting and escaping as 336295367Sdes * necessary. Caller must free returned string. 337295367Sdes */ 338295367Sdesstatic char * 339295367Sdesassemble_argv(int argc, char **argv) 340295367Sdes{ 341295367Sdes int i, j, ws, r; 342295367Sdes char c, *ret; 343295367Sdes struct sshbuf *buf, *arg; 344295367Sdes 345295367Sdes if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 346295367Sdes fatal("%s: sshbuf_new failed", __func__); 347295367Sdes 348295367Sdes for (i = 0; i < argc; i++) { 349295367Sdes ws = 0; 350295367Sdes sshbuf_reset(arg); 351295367Sdes for (j = 0; argv[i][j] != '\0'; j++) { 352295367Sdes r = 0; 353295367Sdes c = argv[i][j]; 354295367Sdes switch (c) { 355295367Sdes case ' ': 356295367Sdes case '\t': 357295367Sdes ws = 1; 358295367Sdes r = sshbuf_put_u8(arg, c); 359295367Sdes break; 360295367Sdes case '\\': 361295367Sdes case '\'': 362295367Sdes case '"': 363295367Sdes if ((r = sshbuf_put_u8(arg, '\\')) != 0) 364295367Sdes break; 365295367Sdes /* FALLTHROUGH */ 366295367Sdes default: 367295367Sdes r = sshbuf_put_u8(arg, c); 368295367Sdes break; 369295367Sdes } 370295367Sdes if (r != 0) 371295367Sdes fatal("%s: sshbuf_put_u8: %s", 372295367Sdes __func__, ssh_err(r)); 373295367Sdes } 374295367Sdes if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 375295367Sdes (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 376295367Sdes (r = sshbuf_putb(buf, arg)) != 0 || 377295367Sdes (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 378295367Sdes fatal("%s: buffer error: %s", __func__, ssh_err(r)); 379295367Sdes } 380295367Sdes if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 381295367Sdes fatal("%s: malloc failed", __func__); 382295367Sdes memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 383295367Sdes ret[sshbuf_len(buf)] = '\0'; 384295367Sdes sshbuf_free(buf); 385295367Sdes sshbuf_free(arg); 386295367Sdes return ret; 387295367Sdes} 388295367Sdes 389295367Sdes/* 390295367Sdes * Runs command in a subprocess. Returns pid on success and a FILE* to the 391295367Sdes * subprocess' stdout or 0 on failure. 392295367Sdes * NB. "command" is only used for logging. 393295367Sdes */ 394295367Sdesstatic pid_t 395295367Sdessubprocess(const char *tag, struct passwd *pw, const char *command, 396295367Sdes int ac, char **av, FILE **child) 397295367Sdes{ 398295367Sdes FILE *f; 399295367Sdes struct stat st; 400295367Sdes int devnull, p[2], i; 401295367Sdes pid_t pid; 402295367Sdes char *cp, errmsg[512]; 403295367Sdes u_int envsize; 404295367Sdes char **child_env; 405295367Sdes 406295367Sdes *child = NULL; 407295367Sdes 408295367Sdes debug3("%s: %s command \"%s\" running as %s", __func__, 409295367Sdes tag, command, pw->pw_name); 410295367Sdes 411295367Sdes /* Verify the path exists and is safe-ish to execute */ 412295367Sdes if (*av[0] != '/') { 413295367Sdes error("%s path is not absolute", tag); 414295367Sdes return 0; 415295367Sdes } 416295367Sdes temporarily_use_uid(pw); 417295367Sdes if (stat(av[0], &st) < 0) { 418295367Sdes error("Could not stat %s \"%s\": %s", tag, 419295367Sdes av[0], strerror(errno)); 420295367Sdes restore_uid(); 421295367Sdes return 0; 422295367Sdes } 423295367Sdes if (auth_secure_path(av[0], &st, NULL, 0, 424295367Sdes errmsg, sizeof(errmsg)) != 0) { 425295367Sdes error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 426295367Sdes restore_uid(); 427295367Sdes return 0; 428295367Sdes } 429295367Sdes 430295367Sdes /* 431295367Sdes * Run the command; stderr is left in place, stdout is the 432295367Sdes * authorized_keys output. 433295367Sdes */ 434295367Sdes if (pipe(p) != 0) { 435295367Sdes error("%s: pipe: %s", tag, strerror(errno)); 436295367Sdes restore_uid(); 437295367Sdes return 0; 438295367Sdes } 439295367Sdes 440295367Sdes /* 441295367Sdes * Don't want to call this in the child, where it can fatal() and 442295367Sdes * run cleanup_exit() code. 443295367Sdes */ 444295367Sdes restore_uid(); 445295367Sdes 446295367Sdes switch ((pid = fork())) { 447295367Sdes case -1: /* error */ 448295367Sdes error("%s: fork: %s", tag, strerror(errno)); 449295367Sdes close(p[0]); 450295367Sdes close(p[1]); 451295367Sdes return 0; 452295367Sdes case 0: /* child */ 453295367Sdes /* Prepare a minimal environment for the child. */ 454295367Sdes envsize = 5; 455295367Sdes child_env = xcalloc(sizeof(*child_env), envsize); 456295367Sdes child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH); 457295367Sdes child_set_env(&child_env, &envsize, "USER", pw->pw_name); 458295367Sdes child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name); 459295367Sdes child_set_env(&child_env, &envsize, "HOME", pw->pw_dir); 460295367Sdes if ((cp = getenv("LANG")) != NULL) 461295367Sdes child_set_env(&child_env, &envsize, "LANG", cp); 462295367Sdes 463295367Sdes for (i = 0; i < NSIG; i++) 464295367Sdes signal(i, SIG_DFL); 465295367Sdes 466295367Sdes if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 467295367Sdes error("%s: open %s: %s", tag, _PATH_DEVNULL, 468295367Sdes strerror(errno)); 469295367Sdes _exit(1); 470295367Sdes } 471295367Sdes /* Keep stderr around a while longer to catch errors */ 472295367Sdes if (dup2(devnull, STDIN_FILENO) == -1 || 473295367Sdes dup2(p[1], STDOUT_FILENO) == -1) { 474295367Sdes error("%s: dup2: %s", tag, strerror(errno)); 475295367Sdes _exit(1); 476295367Sdes } 477295367Sdes closefrom(STDERR_FILENO + 1); 478295367Sdes 479295367Sdes /* Don't use permanently_set_uid() here to avoid fatal() */ 480295367Sdes if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) { 481295367Sdes error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 482295367Sdes strerror(errno)); 483295367Sdes _exit(1); 484295367Sdes } 485295367Sdes if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) { 486295367Sdes error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 487295367Sdes strerror(errno)); 488295367Sdes _exit(1); 489295367Sdes } 490295367Sdes /* stdin is pointed to /dev/null at this point */ 491295367Sdes if (dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 492295367Sdes error("%s: dup2: %s", tag, strerror(errno)); 493295367Sdes _exit(1); 494295367Sdes } 495295367Sdes 496295367Sdes execve(av[0], av, child_env); 497295367Sdes error("%s exec \"%s\": %s", tag, command, strerror(errno)); 498295367Sdes _exit(127); 499295367Sdes default: /* parent */ 500295367Sdes break; 501295367Sdes } 502295367Sdes 503295367Sdes close(p[1]); 504295367Sdes if ((f = fdopen(p[0], "r")) == NULL) { 505295367Sdes error("%s: fdopen: %s", tag, strerror(errno)); 506295367Sdes close(p[0]); 507295367Sdes /* Don't leave zombie child */ 508295367Sdes kill(pid, SIGTERM); 509295367Sdes while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 510295367Sdes ; 511295367Sdes return 0; 512295367Sdes } 513295367Sdes /* Success */ 514295367Sdes debug3("%s: %s pid %ld", __func__, tag, (long)pid); 515295367Sdes *child = f; 516295367Sdes return pid; 517295367Sdes} 518295367Sdes 519295367Sdes/* Returns 0 if pid exited cleanly, non-zero otherwise */ 520295367Sdesstatic int 521295367Sdesexited_cleanly(pid_t pid, const char *tag, const char *cmd) 522295367Sdes{ 523295367Sdes int status; 524295367Sdes 525295367Sdes while (waitpid(pid, &status, 0) == -1) { 526295367Sdes if (errno != EINTR) { 527295367Sdes error("%s: waitpid: %s", tag, strerror(errno)); 528295367Sdes return -1; 529295367Sdes } 530295367Sdes } 531295367Sdes if (WIFSIGNALED(status)) { 532295367Sdes error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 533295367Sdes return -1; 534295367Sdes } else if (WEXITSTATUS(status) != 0) { 535295367Sdes error("%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 536295367Sdes return -1; 537295367Sdes } 538295367Sdes return 0; 539295367Sdes} 540295367Sdes 541295367Sdesstatic int 542295367Sdesmatch_principals_option(const char *principal_list, struct sshkey_cert *cert) 543295367Sdes{ 544215116Sdes char *result; 545215116Sdes u_int i; 546215116Sdes 547215116Sdes /* XXX percent_expand() sequences for authorized_principals? */ 548215116Sdes 549215116Sdes for (i = 0; i < cert->nprincipals; i++) { 550215116Sdes if ((result = match_list(cert->principals[i], 551215116Sdes principal_list, NULL)) != NULL) { 552215116Sdes debug3("matched principal from key options \"%.100s\"", 553215116Sdes result); 554255767Sdes free(result); 555215116Sdes return 1; 556215116Sdes } 557215116Sdes } 558215116Sdes return 0; 559215116Sdes} 560215116Sdes 561215116Sdesstatic int 562295367Sdesprocess_principals(FILE *f, char *file, struct passwd *pw, 563295367Sdes struct sshkey_cert *cert) 564215116Sdes{ 565215116Sdes char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts; 566215116Sdes u_long linenum = 0; 567215116Sdes u_int i; 568215116Sdes 569215116Sdes while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) { 570215116Sdes /* Skip leading whitespace. */ 571215116Sdes for (cp = line; *cp == ' ' || *cp == '\t'; cp++) 572215116Sdes ; 573215116Sdes /* Skip blank and comment lines. */ 574215116Sdes if ((ep = strchr(cp, '#')) != NULL) 575215116Sdes *ep = '\0'; 576215116Sdes if (!*cp || *cp == '\n') 577215116Sdes continue; 578215116Sdes /* Trim trailing whitespace. */ 579215116Sdes ep = cp + strlen(cp) - 1; 580215116Sdes while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t')) 581215116Sdes *ep-- = '\0'; 582215116Sdes /* 583215116Sdes * If the line has internal whitespace then assume it has 584215116Sdes * key options. 585215116Sdes */ 586215116Sdes line_opts = NULL; 587215116Sdes if ((ep = strrchr(cp, ' ')) != NULL || 588215116Sdes (ep = strrchr(cp, '\t')) != NULL) { 589215116Sdes for (; *ep == ' ' || *ep == '\t'; ep++) 590221420Sdes ; 591215116Sdes line_opts = cp; 592215116Sdes cp = ep; 593215116Sdes } 594215116Sdes for (i = 0; i < cert->nprincipals; i++) { 595215116Sdes if (strcmp(cp, cert->principals[i]) == 0) { 596295367Sdes debug3("%s:%lu: matched principal \"%.100s\"", 597295367Sdes file == NULL ? "(command)" : file, 598295367Sdes linenum, cert->principals[i]); 599215116Sdes if (auth_parse_options(pw, line_opts, 600215116Sdes file, linenum) != 1) 601215116Sdes continue; 602215116Sdes return 1; 603215116Sdes } 604215116Sdes } 605215116Sdes } 606295367Sdes return 0; 607295367Sdes} 608295367Sdes 609295367Sdesstatic int 610295367Sdesmatch_principals_file(char *file, struct passwd *pw, struct sshkey_cert *cert) 611295367Sdes{ 612295367Sdes FILE *f; 613295367Sdes int success; 614295367Sdes 615295367Sdes temporarily_use_uid(pw); 616295367Sdes debug("trying authorized principals file %s", file); 617295367Sdes if ((f = auth_openprincipals(file, pw, options.strict_modes)) == NULL) { 618295367Sdes restore_uid(); 619295367Sdes return 0; 620295367Sdes } 621295367Sdes success = process_principals(f, file, pw, cert); 622215116Sdes fclose(f); 623215116Sdes restore_uid(); 624295367Sdes return success; 625248619Sdes} 626215116Sdes 627248619Sdes/* 628295367Sdes * Checks whether principal is allowed in output of command. 629295367Sdes * returns 1 if the principal is allowed or 0 otherwise. 630295367Sdes */ 631295367Sdesstatic int 632295367Sdesmatch_principals_command(struct passwd *user_pw, struct sshkey_cert *cert) 633295367Sdes{ 634295367Sdes FILE *f = NULL; 635295367Sdes int ok, found_principal = 0; 636295367Sdes struct passwd *pw; 637295367Sdes int i, ac = 0, uid_swapped = 0; 638295367Sdes pid_t pid; 639295367Sdes char *tmp, *username = NULL, *command = NULL, **av = NULL; 640295367Sdes void (*osigchld)(int); 641295367Sdes 642295367Sdes if (options.authorized_principals_command == NULL) 643295367Sdes return 0; 644295367Sdes if (options.authorized_principals_command_user == NULL) { 645295367Sdes error("No user for AuthorizedPrincipalsCommand specified, " 646295367Sdes "skipping"); 647295367Sdes return 0; 648295367Sdes } 649295367Sdes 650295367Sdes /* 651295367Sdes * NB. all returns later this function should go via "out" to 652295367Sdes * ensure the original SIGCHLD handler is restored properly. 653295367Sdes */ 654295367Sdes osigchld = signal(SIGCHLD, SIG_DFL); 655295367Sdes 656295367Sdes /* Prepare and verify the user for the command */ 657295367Sdes username = percent_expand(options.authorized_principals_command_user, 658295367Sdes "u", user_pw->pw_name, (char *)NULL); 659295367Sdes pw = getpwnam(username); 660295367Sdes if (pw == NULL) { 661295367Sdes error("AuthorizedPrincipalsCommandUser \"%s\" not found: %s", 662295367Sdes username, strerror(errno)); 663295367Sdes goto out; 664295367Sdes } 665295367Sdes 666295367Sdes /* Turn the command into an argument vector */ 667295367Sdes if (split_argv(options.authorized_principals_command, &ac, &av) != 0) { 668295367Sdes error("AuthorizedPrincipalsCommand \"%s\" contains " 669295367Sdes "invalid quotes", command); 670295367Sdes goto out; 671295367Sdes } 672295367Sdes if (ac == 0) { 673295367Sdes error("AuthorizedPrincipalsCommand \"%s\" yielded no arguments", 674295367Sdes command); 675295367Sdes goto out; 676295367Sdes } 677295367Sdes for (i = 1; i < ac; i++) { 678295367Sdes tmp = percent_expand(av[i], 679295367Sdes "u", user_pw->pw_name, 680295367Sdes "h", user_pw->pw_dir, 681295367Sdes (char *)NULL); 682295367Sdes if (tmp == NULL) 683295367Sdes fatal("%s: percent_expand failed", __func__); 684295367Sdes free(av[i]); 685295367Sdes av[i] = tmp; 686295367Sdes } 687295367Sdes /* Prepare a printable command for logs, etc. */ 688295367Sdes command = assemble_argv(ac, av); 689295367Sdes 690295367Sdes if ((pid = subprocess("AuthorizedPrincipalsCommand", pw, command, 691295367Sdes ac, av, &f)) == 0) 692295367Sdes goto out; 693295367Sdes 694295367Sdes uid_swapped = 1; 695295367Sdes temporarily_use_uid(pw); 696295367Sdes 697295367Sdes ok = process_principals(f, NULL, pw, cert); 698295367Sdes 699295367Sdes if (exited_cleanly(pid, "AuthorizedPrincipalsCommand", command) != 0) 700295367Sdes goto out; 701295367Sdes 702295367Sdes /* Read completed successfully */ 703295367Sdes found_principal = ok; 704295367Sdes out: 705295367Sdes if (f != NULL) 706295367Sdes fclose(f); 707295367Sdes signal(SIGCHLD, osigchld); 708295367Sdes for (i = 0; i < ac; i++) 709295367Sdes free(av[i]); 710295367Sdes free(av); 711295367Sdes if (uid_swapped) 712295367Sdes restore_uid(); 713295367Sdes free(command); 714295367Sdes free(username); 715295367Sdes return found_principal; 716295367Sdes} 717295367Sdes/* 718248619Sdes * Checks whether key is allowed in authorized_keys-format file, 719248619Sdes * returns 1 if the key is allowed or 0 otherwise. 720248619Sdes */ 72198675Sdesstatic int 722248619Sdescheck_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw) 72398675Sdes{ 724146998Sdes char line[SSH_MAX_PUBKEY_BYTES]; 725204917Sdes const char *reason; 72698675Sdes int found_key = 0; 72798675Sdes u_long linenum = 0; 72898675Sdes Key *found; 72998675Sdes char *fp; 73098675Sdes 73198675Sdes found_key = 0; 73298675Sdes 733255767Sdes found = NULL; 734146998Sdes while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) { 735137015Sdes char *cp, *key_options = NULL; 736255767Sdes if (found != NULL) 737255767Sdes key_free(found); 738255767Sdes found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type); 739204917Sdes auth_clear_options(); 740204917Sdes 74198675Sdes /* Skip leading whitespace, empty and comment lines. */ 74298675Sdes for (cp = line; *cp == ' ' || *cp == '\t'; cp++) 74398675Sdes ; 74498675Sdes if (!*cp || *cp == '\n' || *cp == '#') 74598675Sdes continue; 74698675Sdes 74798675Sdes if (key_read(found, &cp) != 1) { 74898675Sdes /* no key? check if there are options for this key */ 74998675Sdes int quoted = 0; 75098675Sdes debug2("user_key_allowed: check options: '%s'", cp); 751137015Sdes key_options = cp; 75298675Sdes for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { 75398675Sdes if (*cp == '\\' && cp[1] == '"') 75498675Sdes cp++; /* Skip both */ 75598675Sdes else if (*cp == '"') 75698675Sdes quoted = !quoted; 75798675Sdes } 75898675Sdes /* Skip remaining whitespace. */ 75998675Sdes for (; *cp == ' ' || *cp == '\t'; cp++) 76098675Sdes ; 76198675Sdes if (key_read(found, &cp) != 1) { 76298675Sdes debug2("user_key_allowed: advance: '%s'", cp); 76398675Sdes /* still no key? advance to next line*/ 76498675Sdes continue; 76598675Sdes } 76698675Sdes } 767215116Sdes if (key_is_cert(key)) { 768215116Sdes if (!key_equal(found, key->cert->signature_key)) 769215116Sdes continue; 770215116Sdes if (auth_parse_options(pw, key_options, file, 771215116Sdes linenum) != 1) 772215116Sdes continue; 773204917Sdes if (!key_is_cert_authority) 774204917Sdes continue; 775295367Sdes if ((fp = sshkey_fingerprint(found, 776295367Sdes options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 777295367Sdes continue; 778207319Sdes debug("matching CA found: file %s, line %lu, %s %s", 779207319Sdes file, linenum, key_type(found), fp); 780215116Sdes /* 781215116Sdes * If the user has specified a list of principals as 782215116Sdes * a key option, then prefer that list to matching 783215116Sdes * their username in the certificate principals list. 784215116Sdes */ 785215116Sdes if (authorized_principals != NULL && 786215116Sdes !match_principals_option(authorized_principals, 787215116Sdes key->cert)) { 788215116Sdes reason = "Certificate does not contain an " 789215116Sdes "authorized principal"; 790215116Sdes fail_reason: 791255767Sdes free(fp); 792204917Sdes error("%s", reason); 793204917Sdes auth_debug_add("%s", reason); 794204917Sdes continue; 795204917Sdes } 796215116Sdes if (key_cert_check_authority(key, 0, 0, 797215116Sdes authorized_principals == NULL ? pw->pw_name : NULL, 798215116Sdes &reason) != 0) 799215116Sdes goto fail_reason; 800215116Sdes if (auth_cert_options(key, pw) != 0) { 801255767Sdes free(fp); 802204917Sdes continue; 803207319Sdes } 804296781Sdes verbose("Accepted certificate ID \"%s\" (serial %llu) " 805207319Sdes "signed by %s CA %s via %s", key->cert->key_id, 806296781Sdes (unsigned long long)key->cert->serial, 807207319Sdes key_type(found), fp, file); 808255767Sdes free(fp); 80998675Sdes found_key = 1; 810204917Sdes break; 811215116Sdes } else if (key_equal(found, key)) { 812215116Sdes if (auth_parse_options(pw, key_options, file, 813215116Sdes linenum) != 1) 814215116Sdes continue; 815215116Sdes if (key_is_cert_authority) 816215116Sdes continue; 817295367Sdes if ((fp = sshkey_fingerprint(found, 818295367Sdes options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 819295367Sdes continue; 820255767Sdes debug("matching key found: file %s, line %lu %s %s", 821255767Sdes file, linenum, key_type(found), fp); 822255767Sdes free(fp); 823295367Sdes found_key = 1; 82498675Sdes break; 82598675Sdes } 82698675Sdes } 827255767Sdes if (found != NULL) 828255767Sdes key_free(found); 82998675Sdes if (!found_key) 83098675Sdes debug2("key not found"); 83198675Sdes return found_key; 83298675Sdes} 83398675Sdes 834204917Sdes/* Authenticate a certificate key against TrustedUserCAKeys */ 835204917Sdesstatic int 836204917Sdesuser_cert_trusted_ca(struct passwd *pw, Key *key) 837204917Sdes{ 838215116Sdes char *ca_fp, *principals_file = NULL; 839204917Sdes const char *reason; 840295367Sdes int ret = 0, found_principal = 0, use_authorized_principals; 841204917Sdes 842204917Sdes if (!key_is_cert(key) || options.trusted_user_ca_keys == NULL) 843204917Sdes return 0; 844204917Sdes 845295367Sdes if ((ca_fp = sshkey_fingerprint(key->cert->signature_key, 846295367Sdes options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) 847295367Sdes return 0; 848204917Sdes 849295367Sdes if (sshkey_in_file(key->cert->signature_key, 850295367Sdes options.trusted_user_ca_keys, 1, 0) != 0) { 851204917Sdes debug2("%s: CA %s %s is not listed in %s", __func__, 852204917Sdes key_type(key->cert->signature_key), ca_fp, 853204917Sdes options.trusted_user_ca_keys); 854204917Sdes goto out; 855204917Sdes } 856215116Sdes /* 857215116Sdes * If AuthorizedPrincipals is in use, then compare the certificate 858215116Sdes * principals against the names in that file rather than matching 859215116Sdes * against the username. 860215116Sdes */ 861215116Sdes if ((principals_file = authorized_principals_file(pw)) != NULL) { 862295367Sdes if (match_principals_file(principals_file, pw, key->cert)) 863295367Sdes found_principal = 1; 864295367Sdes } 865295367Sdes /* Try querying command if specified */ 866295367Sdes if (!found_principal && match_principals_command(pw, key->cert)) 867295367Sdes found_principal = 1; 868295367Sdes /* If principals file or command is specified, then require a match */ 869295367Sdes use_authorized_principals = principals_file != NULL || 870295367Sdes options.authorized_principals_command != NULL; 871295367Sdes if (!found_principal && use_authorized_principals) { 872295367Sdes reason = "Certificate does not contain an authorized principal"; 873215116Sdes fail_reason: 874295367Sdes error("%s", reason); 875295367Sdes auth_debug_add("%s", reason); 876295367Sdes goto out; 877204917Sdes } 878215116Sdes if (key_cert_check_authority(key, 0, 1, 879295367Sdes use_authorized_principals ? NULL : pw->pw_name, &reason) != 0) 880215116Sdes goto fail_reason; 881215116Sdes if (auth_cert_options(key, pw) != 0) 882204917Sdes goto out; 883204917Sdes 884296781Sdes verbose("Accepted certificate ID \"%s\" (serial %llu) signed by " 885296781Sdes "%s CA %s via %s", key->cert->key_id, 886296781Sdes (unsigned long long)key->cert->serial, 887296781Sdes key_type(key->cert->signature_key), ca_fp, 888207319Sdes options.trusted_user_ca_keys); 889204917Sdes ret = 1; 890204917Sdes 891204917Sdes out: 892255767Sdes free(principals_file); 893255767Sdes free(ca_fp); 894204917Sdes return ret; 895204917Sdes} 896204917Sdes 897248619Sdes/* 898248619Sdes * Checks whether key is allowed in file. 899248619Sdes * returns 1 if the key is allowed or 0 otherwise. 900248619Sdes */ 901248619Sdesstatic int 902248619Sdesuser_key_allowed2(struct passwd *pw, Key *key, char *file) 903248619Sdes{ 904248619Sdes FILE *f; 905248619Sdes int found_key = 0; 906248619Sdes 907248619Sdes /* Temporarily use the user's uid. */ 908248619Sdes temporarily_use_uid(pw); 909248619Sdes 910248619Sdes debug("trying public key file %s", file); 911248619Sdes if ((f = auth_openkeyfile(file, pw, options.strict_modes)) != NULL) { 912248619Sdes found_key = check_authkeys_file(f, file, key, pw); 913248619Sdes fclose(f); 914248619Sdes } 915248619Sdes 916248619Sdes restore_uid(); 917248619Sdes return found_key; 918248619Sdes} 919248619Sdes 920248619Sdes/* 921248619Sdes * Checks whether key is allowed in output of command. 922248619Sdes * returns 1 if the key is allowed or 0 otherwise. 923248619Sdes */ 924248619Sdesstatic int 925248619Sdesuser_key_command_allowed2(struct passwd *user_pw, Key *key) 926248619Sdes{ 927295367Sdes FILE *f = NULL; 928295367Sdes int r, ok, found_key = 0; 929248619Sdes struct passwd *pw; 930295367Sdes int i, uid_swapped = 0, ac = 0; 931248619Sdes pid_t pid; 932295367Sdes char *username = NULL, *key_fp = NULL, *keytext = NULL; 933295367Sdes char *tmp, *command = NULL, **av = NULL; 934295367Sdes void (*osigchld)(int); 935248619Sdes 936295367Sdes if (options.authorized_keys_command == NULL) 937248619Sdes return 0; 938248619Sdes if (options.authorized_keys_command_user == NULL) { 939248619Sdes error("No user for AuthorizedKeysCommand specified, skipping"); 940248619Sdes return 0; 941248619Sdes } 942248619Sdes 943295367Sdes /* 944295367Sdes * NB. all returns later this function should go via "out" to 945295367Sdes * ensure the original SIGCHLD handler is restored properly. 946295367Sdes */ 947295367Sdes osigchld = signal(SIGCHLD, SIG_DFL); 948295367Sdes 949295367Sdes /* Prepare and verify the user for the command */ 950248619Sdes username = percent_expand(options.authorized_keys_command_user, 951248619Sdes "u", user_pw->pw_name, (char *)NULL); 952248619Sdes pw = getpwnam(username); 953248619Sdes if (pw == NULL) { 954248619Sdes error("AuthorizedKeysCommandUser \"%s\" not found: %s", 955248619Sdes username, strerror(errno)); 956295367Sdes goto out; 957248619Sdes } 958248619Sdes 959295367Sdes /* Prepare AuthorizedKeysCommand */ 960295367Sdes if ((key_fp = sshkey_fingerprint(key, options.fingerprint_hash, 961295367Sdes SSH_FP_DEFAULT)) == NULL) { 962295367Sdes error("%s: sshkey_fingerprint failed", __func__); 963248619Sdes goto out; 964248619Sdes } 965295367Sdes if ((r = sshkey_to_base64(key, &keytext)) != 0) { 966295367Sdes error("%s: sshkey_to_base64 failed: %s", __func__, ssh_err(r)); 967248619Sdes goto out; 968248619Sdes } 969248619Sdes 970295367Sdes /* Turn the command into an argument vector */ 971295367Sdes if (split_argv(options.authorized_keys_command, &ac, &av) != 0) { 972295367Sdes error("AuthorizedKeysCommand \"%s\" contains invalid quotes", 973295367Sdes command); 974248619Sdes goto out; 975248619Sdes } 976295367Sdes if (ac == 0) { 977295367Sdes error("AuthorizedKeysCommand \"%s\" yielded no arguments", 978295367Sdes command); 979295367Sdes goto out; 980295367Sdes } 981295367Sdes for (i = 1; i < ac; i++) { 982295367Sdes tmp = percent_expand(av[i], 983295367Sdes "u", user_pw->pw_name, 984295367Sdes "h", user_pw->pw_dir, 985295367Sdes "t", sshkey_ssh_name(key), 986295367Sdes "f", key_fp, 987295367Sdes "k", keytext, 988295367Sdes (char *)NULL); 989295367Sdes if (tmp == NULL) 990295367Sdes fatal("%s: percent_expand failed", __func__); 991295367Sdes free(av[i]); 992295367Sdes av[i] = tmp; 993295367Sdes } 994295367Sdes /* Prepare a printable command for logs, etc. */ 995295367Sdes command = assemble_argv(ac, av); 996248619Sdes 997248619Sdes /* 998295367Sdes * If AuthorizedKeysCommand was run without arguments 999295367Sdes * then fall back to the old behaviour of passing the 1000295367Sdes * target username as a single argument. 1001248619Sdes */ 1002295367Sdes if (ac == 1) { 1003295367Sdes av = xreallocarray(av, ac + 2, sizeof(*av)); 1004295367Sdes av[1] = xstrdup(user_pw->pw_name); 1005295367Sdes av[2] = NULL; 1006295367Sdes /* Fix up command too, since it is used in log messages */ 1007295367Sdes free(command); 1008295367Sdes xasprintf(&command, "%s %s", av[0], av[1]); 1009295367Sdes } 1010248619Sdes 1011295367Sdes if ((pid = subprocess("AuthorizedKeysCommand", pw, command, 1012295367Sdes ac, av, &f)) == 0) 1013295367Sdes goto out; 1014248619Sdes 1015295367Sdes uid_swapped = 1; 1016248619Sdes temporarily_use_uid(pw); 1017248619Sdes 1018248619Sdes ok = check_authkeys_file(f, options.authorized_keys_command, key, pw); 1019248619Sdes 1020295367Sdes if (exited_cleanly(pid, "AuthorizedKeysCommand", command) != 0) 1021248619Sdes goto out; 1022295367Sdes 1023295367Sdes /* Read completed successfully */ 1024248619Sdes found_key = ok; 1025248619Sdes out: 1026295367Sdes if (f != NULL) 1027295367Sdes fclose(f); 1028295367Sdes signal(SIGCHLD, osigchld); 1029295367Sdes for (i = 0; i < ac; i++) 1030295367Sdes free(av[i]); 1031295367Sdes free(av); 1032295367Sdes if (uid_swapped) 1033295367Sdes restore_uid(); 1034295367Sdes free(command); 1035295367Sdes free(username); 1036295367Sdes free(key_fp); 1037295367Sdes free(keytext); 1038248619Sdes return found_key; 1039248619Sdes} 1040248619Sdes 1041248619Sdes/* 1042248619Sdes * Check whether key authenticates and authorises the user. 1043248619Sdes */ 104498675Sdesint 1045295367Sdesuser_key_allowed(struct passwd *pw, Key *key, int auth_attempt) 104698675Sdes{ 1047226046Sdes u_int success, i; 104898675Sdes char *file; 104998675Sdes 1050204917Sdes if (auth_key_is_revoked(key)) 1051204917Sdes return 0; 1052204917Sdes if (key_is_cert(key) && auth_key_is_revoked(key->cert->signature_key)) 1053204917Sdes return 0; 1054204917Sdes 1055204917Sdes success = user_cert_trusted_ca(pw, key); 1056204917Sdes if (success) 1057204917Sdes return success; 1058204917Sdes 1059248619Sdes success = user_key_command_allowed2(pw, key); 1060248619Sdes if (success > 0) 1061248619Sdes return success; 1062248619Sdes 1063226046Sdes for (i = 0; !success && i < options.num_authkeys_files; i++) { 1064248619Sdes 1065248619Sdes if (strcasecmp(options.authorized_keys_files[i], "none") == 0) 1066248619Sdes continue; 1067226046Sdes file = expand_authorized_keys( 1068226046Sdes options.authorized_keys_files[i], pw); 1069248619Sdes 1070226046Sdes success = user_key_allowed2(pw, key, file); 1071255767Sdes free(file); 1072226046Sdes } 107398675Sdes 107498675Sdes return success; 107598675Sdes} 107698675Sdes 1077295367Sdes/* Records a public key in the list of previously-successful keys */ 1078295367Sdesvoid 1079295367Sdesauth2_record_userkey(Authctxt *authctxt, struct sshkey *key) 1080295367Sdes{ 1081295367Sdes struct sshkey **tmp; 1082295367Sdes 1083295367Sdes if (authctxt->nprev_userkeys >= INT_MAX || 1084295367Sdes (tmp = reallocarray(authctxt->prev_userkeys, 1085295367Sdes authctxt->nprev_userkeys + 1, sizeof(*tmp))) == NULL) 1086295367Sdes fatal("%s: reallocarray failed", __func__); 1087295367Sdes authctxt->prev_userkeys = tmp; 1088295367Sdes authctxt->prev_userkeys[authctxt->nprev_userkeys] = key; 1089295367Sdes authctxt->nprev_userkeys++; 1090295367Sdes} 1091295367Sdes 1092295367Sdes/* Checks whether a key has already been used successfully for authentication */ 1093295367Sdesint 1094295367Sdesauth2_userkey_already_used(Authctxt *authctxt, struct sshkey *key) 1095295367Sdes{ 1096295367Sdes u_int i; 1097295367Sdes 1098295367Sdes for (i = 0; i < authctxt->nprev_userkeys; i++) { 1099295367Sdes if (sshkey_equal_public(key, authctxt->prev_userkeys[i])) { 1100295367Sdes return 1; 1101295367Sdes } 1102295367Sdes } 1103295367Sdes return 0; 1104295367Sdes} 1105295367Sdes 110698675SdesAuthmethod method_pubkey = { 110798675Sdes "publickey", 110898675Sdes userauth_pubkey, 110998675Sdes &options.pubkey_authentication 111098675Sdes}; 1111