1295367Sdes/* $OpenBSD: auth.c,v 1.113 2015/08/21 03:42:19 djm Exp $ */ 260573Skris/* 376262Sgreen * Copyright (c) 2000 Markus Friedl. All rights reserved. 465674Skris * 565674Skris * Redistribution and use in source and binary forms, with or without 665674Skris * modification, are permitted provided that the following conditions 765674Skris * are met: 865674Skris * 1. Redistributions of source code must retain the above copyright 965674Skris * notice, this list of conditions and the following disclaimer. 1065674Skris * 2. Redistributions in binary form must reproduce the above copyright 1165674Skris * notice, this list of conditions and the following disclaimer in the 1265674Skris * documentation and/or other materials provided with the distribution. 1365674Skris * 1465674Skris * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1565674Skris * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1665674Skris * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1765674Skris * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1865674Skris * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1965674Skris * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2065674Skris * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2165674Skris * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2265674Skris * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2365674Skris * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2460573Skris */ 2560573Skris 2660573Skris#include "includes.h" 27162856Sdes__RCSID("$FreeBSD: releng/10.3/crypto/openssh/auth.c 295367 2016-02-07 11:38:54Z des $"); 2860573Skris 29162856Sdes#include <sys/types.h> 30162856Sdes#include <sys/stat.h> 31162856Sdes 32162856Sdes#include <netinet/in.h> 33162856Sdes 34162856Sdes#include <errno.h> 35181111Sdes#include <fcntl.h> 36162856Sdes#ifdef HAVE_PATHS_H 37162856Sdes# include <paths.h> 38162856Sdes#endif 39162856Sdes#include <pwd.h> 4098941Sdes#ifdef HAVE_LOGIN_H 4198941Sdes#include <login.h> 4298941Sdes#endif 43126277Sdes#ifdef USE_SHADOW 4498941Sdes#include <shadow.h> 45126277Sdes#endif 4698941Sdes#ifdef HAVE_LIBGEN_H 4792559Sdes#include <libgen.h> 4898941Sdes#endif 49162856Sdes#include <stdarg.h> 50162856Sdes#include <stdio.h> 51162856Sdes#include <string.h> 52181111Sdes#include <unistd.h> 53295367Sdes#include <limits.h> 5492559Sdes 5560573Skris#include "xmalloc.h" 5676262Sgreen#include "match.h" 5776262Sgreen#include "groupaccess.h" 5876262Sgreen#include "log.h" 59162856Sdes#include "buffer.h" 60295367Sdes#include "misc.h" 6160573Skris#include "servconf.h" 62162856Sdes#include "key.h" 63162856Sdes#include "hostfile.h" 6460573Skris#include "auth.h" 6576262Sgreen#include "auth-options.h" 6676262Sgreen#include "canohost.h" 6792559Sdes#include "uidswap.h" 6898684Sdes#include "packet.h" 69147005Sdes#include "loginrec.h" 70162856Sdes#ifdef GSSAPI 71162856Sdes#include "ssh-gss.h" 72162856Sdes#endif 73204917Sdes#include "authfile.h" 74147005Sdes#include "monitor_wrap.h" 75295367Sdes#include "authfile.h" 76295367Sdes#include "ssherr.h" 77255767Sdes#include "compat.h" 7860573Skris 7960573Skris/* import */ 8060573Skrisextern ServerOptions options; 81162856Sdesextern int use_privsep; 82124211Sdesextern Buffer loginmsg; 83162856Sdesextern struct passwd *privsep_pw; 8460573Skris 8598684Sdes/* Debugging messages */ 8698684SdesBuffer auth_debug; 8798684Sdesint auth_debug_init; 8898684Sdes 8960573Skris/* 9076262Sgreen * Check if the user is allowed to log in via ssh. If user is listed 9176262Sgreen * in DenyUsers or one of user's groups is listed in DenyGroups, false 9276262Sgreen * will be returned. If AllowUsers isn't empty and user isn't listed 9376262Sgreen * there, or if AllowGroups isn't empty and one of user's groups isn't 9476262Sgreen * listed there, false will be returned. 9560573Skris * If the user's shell is not executable, false will be returned. 9660573Skris * Otherwise true is returned. 9760573Skris */ 9860573Skrisint 9960573Skrisallowed_user(struct passwd * pw) 10060573Skris{ 10160573Skris struct stat st; 102124211Sdes const char *hostname = NULL, *ipaddr = NULL, *passwd = NULL; 103149753Sdes u_int i; 104126277Sdes#ifdef USE_SHADOW 105124211Sdes struct spwd *spw = NULL; 106113911Sdes#endif 10760573Skris 10860573Skris /* Shouldn't be called if pw is NULL, but better safe than sorry... */ 10976262Sgreen if (!pw || !pw->pw_name) 11060573Skris return 0; 11160573Skris 112126277Sdes#ifdef USE_SHADOW 113124211Sdes if (!options.use_pam) 114124211Sdes spw = getspnam(pw->pw_name); 115124211Sdes#ifdef HAS_SHADOW_EXPIRE 116126277Sdes if (!options.use_pam && spw != NULL && auth_shadow_acctexpired(spw)) 117126277Sdes return 0; 118124211Sdes#endif /* HAS_SHADOW_EXPIRE */ 119126277Sdes#endif /* USE_SHADOW */ 120124211Sdes 121126277Sdes /* grab passwd field for locked account check */ 122181111Sdes passwd = pw->pw_passwd; 123126277Sdes#ifdef USE_SHADOW 124124211Sdes if (spw != NULL) 125181111Sdes#ifdef USE_LIBIAF 126149753Sdes passwd = get_iaf_password(pw); 127149753Sdes#else 128124211Sdes passwd = spw->sp_pwdp; 129181111Sdes#endif /* USE_LIBIAF */ 13098941Sdes#endif 13198941Sdes 132126277Sdes /* check for locked account */ 133124211Sdes if (!options.use_pam && passwd && *passwd) { 134124211Sdes int locked = 0; 135124211Sdes 136124211Sdes#ifdef LOCKED_PASSWD_STRING 137124211Sdes if (strcmp(passwd, LOCKED_PASSWD_STRING) == 0) 138124211Sdes locked = 1; 139124211Sdes#endif 140124211Sdes#ifdef LOCKED_PASSWD_PREFIX 141124211Sdes if (strncmp(passwd, LOCKED_PASSWD_PREFIX, 142124211Sdes strlen(LOCKED_PASSWD_PREFIX)) == 0) 143124211Sdes locked = 1; 144124211Sdes#endif 145124211Sdes#ifdef LOCKED_PASSWD_SUBSTR 146124211Sdes if (strstr(passwd, LOCKED_PASSWD_SUBSTR)) 147124211Sdes locked = 1; 148124211Sdes#endif 149181111Sdes#ifdef USE_LIBIAF 150215116Sdes free((void *) passwd); 151181111Sdes#endif /* USE_LIBIAF */ 152124211Sdes if (locked) { 153124211Sdes logit("User %.100s not allowed because account is locked", 154124211Sdes pw->pw_name); 155124211Sdes return 0; 156124211Sdes } 157124211Sdes } 158124211Sdes 15961212Skris /* 160204917Sdes * Deny if shell does not exist or is not executable unless we 161204917Sdes * are chrooting. 16261212Skris */ 163204917Sdes if (options.chroot_directory == NULL || 164204917Sdes strcasecmp(options.chroot_directory, "none") == 0) { 165204917Sdes char *shell = xstrdup((pw->pw_shell[0] == '\0') ? 166204917Sdes _PATH_BSHELL : pw->pw_shell); /* empty = /bin/sh */ 16761212Skris 168204917Sdes if (stat(shell, &st) != 0) { 169204917Sdes logit("User %.100s not allowed because shell %.100s " 170204917Sdes "does not exist", pw->pw_name, shell); 171255767Sdes free(shell); 172204917Sdes return 0; 173204917Sdes } 174204917Sdes if (S_ISREG(st.st_mode) == 0 || 175204917Sdes (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP)) == 0) { 176204917Sdes logit("User %.100s not allowed because shell %.100s " 177204917Sdes "is not executable", pw->pw_name, shell); 178255767Sdes free(shell); 179204917Sdes return 0; 180204917Sdes } 181255767Sdes free(shell); 18292559Sdes } 18360573Skris 184147005Sdes if (options.num_deny_users > 0 || options.num_allow_users > 0 || 185147005Sdes options.num_deny_groups > 0 || options.num_allow_groups > 0) { 186124211Sdes hostname = get_canonical_hostname(options.use_dns); 18792559Sdes ipaddr = get_remote_ipaddr(); 18892559Sdes } 18992559Sdes 19060573Skris /* Return false if user is listed in DenyUsers */ 19160573Skris if (options.num_deny_users > 0) { 19260573Skris for (i = 0; i < options.num_deny_users; i++) 19398684Sdes if (match_user(pw->pw_name, hostname, ipaddr, 19492559Sdes options.deny_users[i])) { 195147005Sdes logit("User %.100s from %.100s not allowed " 196147005Sdes "because listed in DenyUsers", 197147005Sdes pw->pw_name, hostname); 19860573Skris return 0; 19992559Sdes } 20060573Skris } 20160573Skris /* Return false if AllowUsers isn't empty and user isn't listed there */ 20260573Skris if (options.num_allow_users > 0) { 20360573Skris for (i = 0; i < options.num_allow_users; i++) 20498684Sdes if (match_user(pw->pw_name, hostname, ipaddr, 20592559Sdes options.allow_users[i])) 20660573Skris break; 20760573Skris /* i < options.num_allow_users iff we break for loop */ 20892559Sdes if (i >= options.num_allow_users) { 209147005Sdes logit("User %.100s from %.100s not allowed because " 210147005Sdes "not listed in AllowUsers", pw->pw_name, hostname); 21160573Skris return 0; 21292559Sdes } 21360573Skris } 21460573Skris if (options.num_deny_groups > 0 || options.num_allow_groups > 0) { 21576262Sgreen /* Get the user's group access list (primary and supplementary) */ 21692559Sdes if (ga_init(pw->pw_name, pw->pw_gid) == 0) { 217147005Sdes logit("User %.100s from %.100s not allowed because " 218147005Sdes "not in any group", pw->pw_name, hostname); 21960573Skris return 0; 22092559Sdes } 22160573Skris 22276262Sgreen /* Return false if one of user's groups is listed in DenyGroups */ 22376262Sgreen if (options.num_deny_groups > 0) 22476262Sgreen if (ga_match(options.deny_groups, 22576262Sgreen options.num_deny_groups)) { 22676262Sgreen ga_free(); 227147005Sdes logit("User %.100s from %.100s not allowed " 228147005Sdes "because a group is listed in DenyGroups", 229147005Sdes pw->pw_name, hostname); 23060573Skris return 0; 23176262Sgreen } 23260573Skris /* 23376262Sgreen * Return false if AllowGroups isn't empty and one of user's groups 23460573Skris * isn't listed there 23560573Skris */ 23676262Sgreen if (options.num_allow_groups > 0) 23776262Sgreen if (!ga_match(options.allow_groups, 23876262Sgreen options.num_allow_groups)) { 23976262Sgreen ga_free(); 240147005Sdes logit("User %.100s from %.100s not allowed " 241147005Sdes "because none of user's groups are listed " 242147005Sdes "in AllowGroups", pw->pw_name, hostname); 24360573Skris return 0; 24476262Sgreen } 24576262Sgreen ga_free(); 24660573Skris } 24798941Sdes 248137019Sdes#ifdef CUSTOM_SYS_AUTH_ALLOWED_USER 249147005Sdes if (!sys_auth_allowed_user(pw, &loginmsg)) 250137019Sdes return 0; 251137019Sdes#endif 252113911Sdes 25360573Skris /* We found no reason not to let this user try to log on... */ 25460573Skris return 1; 25560573Skris} 25676262Sgreen 25776262Sgreenvoid 258255767Sdesauth_info(Authctxt *authctxt, const char *fmt, ...) 259255767Sdes{ 260255767Sdes va_list ap; 261255767Sdes int i; 262255767Sdes 263255767Sdes free(authctxt->info); 264255767Sdes authctxt->info = NULL; 265255767Sdes 266255767Sdes va_start(ap, fmt); 267255767Sdes i = vasprintf(&authctxt->info, fmt, ap); 268255767Sdes va_end(ap); 269255767Sdes 270255767Sdes if (i < 0 || authctxt->info == NULL) 271255767Sdes fatal("vasprintf failed"); 272255767Sdes} 273255767Sdes 274255767Sdesvoid 275248619Sdesauth_log(Authctxt *authctxt, int authenticated, int partial, 276255767Sdes const char *method, const char *submethod) 27776262Sgreen{ 27876262Sgreen void (*authlog) (const char *fmt,...) = verbose; 27976262Sgreen char *authmsg; 28076262Sgreen 281162856Sdes if (use_privsep && !mm_is_monitor() && !authctxt->postponed) 282162856Sdes return; 283162856Sdes 28476262Sgreen /* Raise logging level */ 28576262Sgreen if (authenticated == 1 || 28676262Sgreen !authctxt->valid || 287137019Sdes authctxt->failures >= options.max_authtries / 2 || 28876262Sgreen strcmp(method, "password") == 0) 289124211Sdes authlog = logit; 29076262Sgreen 29176262Sgreen if (authctxt->postponed) 29276262Sgreen authmsg = "Postponed"; 293248619Sdes else if (partial) 294248619Sdes authmsg = "Partial"; 29576262Sgreen else 29676262Sgreen authmsg = authenticated ? "Accepted" : "Failed"; 29776262Sgreen 298255767Sdes authlog("%s %s%s%s for %s%.100s from %.200s port %d %s%s%s", 29976262Sgreen authmsg, 30076262Sgreen method, 301248619Sdes submethod != NULL ? "/" : "", submethod == NULL ? "" : submethod, 302137019Sdes authctxt->valid ? "" : "invalid user ", 30392559Sdes authctxt->user, 30476262Sgreen get_remote_ipaddr(), 30576262Sgreen get_remote_port(), 306255767Sdes compat20 ? "ssh2" : "ssh1", 307255767Sdes authctxt->info != NULL ? ": " : "", 308255767Sdes authctxt->info != NULL ? authctxt->info : ""); 309255767Sdes free(authctxt->info); 310255767Sdes authctxt->info = NULL; 311106130Sdes 312124211Sdes#ifdef CUSTOM_FAILED_LOGIN 313147005Sdes if (authenticated == 0 && !authctxt->postponed && 314147005Sdes (strcmp(method, "password") == 0 || 315147005Sdes strncmp(method, "keyboard-interactive", 20) == 0 || 316147005Sdes strcmp(method, "challenge-response") == 0)) 317147005Sdes record_failed_login(authctxt->user, 318147005Sdes get_canonical_hostname(options.use_dns), "ssh"); 319162856Sdes# ifdef WITH_AIXAUTHENTICATE 320162856Sdes if (authenticated) 321162856Sdes sys_auth_record_login(authctxt->user, 322162856Sdes get_canonical_hostname(options.use_dns), "ssh", &loginmsg); 323162856Sdes# endif 324124211Sdes#endif 325147005Sdes#ifdef SSH_AUDIT_EVENTS 326162856Sdes if (authenticated == 0 && !authctxt->postponed) 327162856Sdes audit_event(audit_classify_auth(method)); 328147005Sdes#endif 32976262Sgreen} 33076262Sgreen 331295367Sdes 332295367Sdesvoid 333295367Sdesauth_maxtries_exceeded(Authctxt *authctxt) 334295367Sdes{ 335295367Sdes error("maximum authentication attempts exceeded for " 336295367Sdes "%s%.100s from %.200s port %d %s", 337295367Sdes authctxt->valid ? "" : "invalid user ", 338295367Sdes authctxt->user, 339295367Sdes get_remote_ipaddr(), 340295367Sdes get_remote_port(), 341295367Sdes compat20 ? "ssh2" : "ssh1"); 342295367Sdes packet_disconnect("Too many authentication failures"); 343295367Sdes /* NOTREACHED */ 344295367Sdes} 345295367Sdes 34676262Sgreen/* 34776262Sgreen * Check whether root logins are disallowed. 34876262Sgreen */ 34976262Sgreenint 350248619Sdesauth_root_allowed(const char *method) 35176262Sgreen{ 35276262Sgreen switch (options.permit_root_login) { 35376262Sgreen case PERMIT_YES: 35476262Sgreen return 1; 35576262Sgreen case PERMIT_NO_PASSWD: 356295367Sdes if (strcmp(method, "publickey") == 0 || 357295367Sdes strcmp(method, "hostbased") == 0 || 358295367Sdes strcmp(method, "gssapi-with-mic") == 0) 35976262Sgreen return 1; 36076262Sgreen break; 36176262Sgreen case PERMIT_FORCED_ONLY: 36276262Sgreen if (forced_command) { 363124211Sdes logit("Root login accepted for forced command."); 36476262Sgreen return 1; 36576262Sgreen } 36676262Sgreen break; 36776262Sgreen } 368124211Sdes logit("ROOT LOGIN REFUSED FROM %.200s", get_remote_ipaddr()); 36976262Sgreen return 0; 37076262Sgreen} 37192559Sdes 37292559Sdes 37392559Sdes/* 37492559Sdes * Given a template and a passwd structure, build a filename 37592559Sdes * by substituting % tokenised options. Currently, %% becomes '%', 37692559Sdes * %h becomes the home directory and %u the username. 37792559Sdes * 37892559Sdes * This returns a buffer allocated by xmalloc. 37992559Sdes */ 380226046Sdeschar * 381149753Sdesexpand_authorized_keys(const char *filename, struct passwd *pw) 38292559Sdes{ 383295367Sdes char *file, ret[PATH_MAX]; 384162856Sdes int i; 38592559Sdes 386149753Sdes file = percent_expand(filename, "h", pw->pw_dir, 387149753Sdes "u", pw->pw_name, (char *)NULL); 38892559Sdes 38992559Sdes /* 39092559Sdes * Ensure that filename starts anchored. If not, be backward 39192559Sdes * compatible and prepend the '%h/' 39292559Sdes */ 393149753Sdes if (*file == '/') 394149753Sdes return (file); 39592559Sdes 396162856Sdes i = snprintf(ret, sizeof(ret), "%s/%s", pw->pw_dir, file); 397162856Sdes if (i < 0 || (size_t)i >= sizeof(ret)) 398149753Sdes fatal("expand_authorized_keys: path too long"); 399255767Sdes free(file); 400162856Sdes return (xstrdup(ret)); 40192559Sdes} 40292559Sdes 40392559Sdeschar * 404215116Sdesauthorized_principals_file(struct passwd *pw) 405215116Sdes{ 406295367Sdes if (options.authorized_principals_file == NULL) 407215116Sdes return NULL; 408215116Sdes return expand_authorized_keys(options.authorized_principals_file, pw); 409215116Sdes} 410215116Sdes 41192559Sdes/* return ok if key exists in sysfile or userfile */ 41292559SdesHostStatus 41392559Sdescheck_key_in_hostfiles(struct passwd *pw, Key *key, const char *host, 41492559Sdes const char *sysfile, const char *userfile) 41592559Sdes{ 41692559Sdes char *user_hostfile; 41792559Sdes struct stat st; 41892559Sdes HostStatus host_status; 419221420Sdes struct hostkeys *hostkeys; 420221420Sdes const struct hostkey_entry *found; 42192559Sdes 422221420Sdes hostkeys = init_hostkeys(); 423221420Sdes load_hostkeys(hostkeys, host, sysfile); 424221420Sdes if (userfile != NULL) { 42592559Sdes user_hostfile = tilde_expand_filename(userfile, pw->pw_uid); 42692559Sdes if (options.strict_modes && 42792559Sdes (stat(user_hostfile, &st) == 0) && 42892559Sdes ((st.st_uid != 0 && st.st_uid != pw->pw_uid) || 42992559Sdes (st.st_mode & 022) != 0)) { 430124211Sdes logit("Authentication refused for %.100s: " 43192559Sdes "bad owner or modes for %.200s", 43292559Sdes pw->pw_name, user_hostfile); 433215116Sdes auth_debug_add("Ignored %.200s: bad ownership or modes", 434215116Sdes user_hostfile); 43592559Sdes } else { 43692559Sdes temporarily_use_uid(pw); 437221420Sdes load_hostkeys(hostkeys, host, user_hostfile); 43892559Sdes restore_uid(); 43992559Sdes } 440255767Sdes free(user_hostfile); 44192559Sdes } 442221420Sdes host_status = check_key_in_hostkeys(hostkeys, key, &found); 443221420Sdes if (host_status == HOST_REVOKED) 444221420Sdes error("WARNING: revoked key for %s attempted authentication", 445221420Sdes found->host); 446221420Sdes else if (host_status == HOST_OK) 447221420Sdes debug("%s: key for %s found at %s:%ld", __func__, 448221420Sdes found->host, found->file, found->line); 449221420Sdes else 450221420Sdes debug("%s: key for host %s not found", __func__, host); 45192559Sdes 452221420Sdes free_hostkeys(hostkeys); 453221420Sdes 45492559Sdes return host_status; 45592559Sdes} 45692559Sdes 45792559Sdes/* 458248619Sdes * Check a given path for security. This is defined as all components 459106130Sdes * of the path to the file must be owned by either the owner of 46092559Sdes * of the file or root and no directories must be group or world writable. 46192559Sdes * 46292559Sdes * XXX Should any specific check be done for sym links ? 46392559Sdes * 464248619Sdes * Takes a file name, its stat information (preferably from fstat() to 465248619Sdes * avoid races), the uid of the expected owner, their home directory and an 46692559Sdes * error buffer plus max size as arguments. 46792559Sdes * 46892559Sdes * Returns 0 on success and -1 on failure 46992559Sdes */ 470248619Sdesint 471248619Sdesauth_secure_path(const char *name, struct stat *stp, const char *pw_dir, 472248619Sdes uid_t uid, char *err, size_t errlen) 47392559Sdes{ 474295367Sdes char buf[PATH_MAX], homedir[PATH_MAX]; 47592559Sdes char *cp; 476113911Sdes int comparehome = 0; 47792559Sdes struct stat st; 47892559Sdes 479248619Sdes if (realpath(name, buf) == NULL) { 480248619Sdes snprintf(err, errlen, "realpath %s failed: %s", name, 48192559Sdes strerror(errno)); 48292559Sdes return -1; 48392559Sdes } 484248619Sdes if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 485113911Sdes comparehome = 1; 48692559Sdes 487248619Sdes if (!S_ISREG(stp->st_mode)) { 488248619Sdes snprintf(err, errlen, "%s is not a regular file", buf); 489248619Sdes return -1; 490248619Sdes } 491248619Sdes if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || 492248619Sdes (stp->st_mode & 022) != 0) { 49392559Sdes snprintf(err, errlen, "bad ownership or modes for file %s", 49492559Sdes buf); 49592559Sdes return -1; 49692559Sdes } 49792559Sdes 49892559Sdes /* for each component of the canonical path, walking upwards */ 49992559Sdes for (;;) { 50092559Sdes if ((cp = dirname(buf)) == NULL) { 50192559Sdes snprintf(err, errlen, "dirname() failed"); 50292559Sdes return -1; 50392559Sdes } 50492559Sdes strlcpy(buf, cp, sizeof(buf)); 50592559Sdes 50692559Sdes if (stat(buf, &st) < 0 || 507248619Sdes (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || 50892559Sdes (st.st_mode & 022) != 0) { 50992559Sdes snprintf(err, errlen, 51092559Sdes "bad ownership or modes for directory %s", buf); 51192559Sdes return -1; 51292559Sdes } 51392559Sdes 514204917Sdes /* If are past the homedir then we can stop */ 515226046Sdes if (comparehome && strcmp(homedir, buf) == 0) 51692559Sdes break; 517226046Sdes 51892559Sdes /* 51992559Sdes * dirname should always complete with a "/" path, 52092559Sdes * but we can be paranoid and check for "." too 52192559Sdes */ 52292559Sdes if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 52392559Sdes break; 52492559Sdes } 52592559Sdes return 0; 52692559Sdes} 52798684Sdes 528248619Sdes/* 529248619Sdes * Version of secure_path() that accepts an open file descriptor to 530248619Sdes * avoid races. 531248619Sdes * 532248619Sdes * Returns 0 on success and -1 on failure 533248619Sdes */ 534248619Sdesstatic int 535248619Sdessecure_filename(FILE *f, const char *file, struct passwd *pw, 536248619Sdes char *err, size_t errlen) 537248619Sdes{ 538248619Sdes struct stat st; 539248619Sdes 540248619Sdes /* check the open file to avoid races */ 541248619Sdes if (fstat(fileno(f), &st) < 0) { 542248619Sdes snprintf(err, errlen, "cannot stat file %s: %s", 543248619Sdes file, strerror(errno)); 544248619Sdes return -1; 545248619Sdes } 546248619Sdes return auth_secure_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 547248619Sdes} 548248619Sdes 549215116Sdesstatic FILE * 550215116Sdesauth_openfile(const char *file, struct passwd *pw, int strict_modes, 551215116Sdes int log_missing, char *file_type) 552181111Sdes{ 553181111Sdes char line[1024]; 554181111Sdes struct stat st; 555181111Sdes int fd; 556181111Sdes FILE *f; 557181111Sdes 558204917Sdes if ((fd = open(file, O_RDONLY|O_NONBLOCK)) == -1) { 559215116Sdes if (log_missing || errno != ENOENT) 560215116Sdes debug("Could not open %s '%s': %s", file_type, file, 561204917Sdes strerror(errno)); 562181111Sdes return NULL; 563204917Sdes } 564181111Sdes 565181111Sdes if (fstat(fd, &st) < 0) { 566181111Sdes close(fd); 567181111Sdes return NULL; 568181111Sdes } 569181111Sdes if (!S_ISREG(st.st_mode)) { 570215116Sdes logit("User %s %s %s is not a regular file", 571215116Sdes pw->pw_name, file_type, file); 572181111Sdes close(fd); 573181111Sdes return NULL; 574181111Sdes } 575181111Sdes unset_nonblock(fd); 576181111Sdes if ((f = fdopen(fd, "r")) == NULL) { 577181111Sdes close(fd); 578181111Sdes return NULL; 579181111Sdes } 580221420Sdes if (strict_modes && 581181111Sdes secure_filename(f, file, pw, line, sizeof(line)) != 0) { 582181111Sdes fclose(f); 583181111Sdes logit("Authentication refused: %s", line); 584215116Sdes auth_debug_add("Ignored %s: %s", file_type, line); 585181111Sdes return NULL; 586181111Sdes } 587181111Sdes 588181111Sdes return f; 589181111Sdes} 590181111Sdes 591215116Sdes 592215116SdesFILE * 593215116Sdesauth_openkeyfile(const char *file, struct passwd *pw, int strict_modes) 594215116Sdes{ 595215116Sdes return auth_openfile(file, pw, strict_modes, 1, "authorized keys"); 596215116Sdes} 597215116Sdes 598215116SdesFILE * 599215116Sdesauth_openprincipals(const char *file, struct passwd *pw, int strict_modes) 600215116Sdes{ 601215116Sdes return auth_openfile(file, pw, strict_modes, 0, 602215116Sdes "authorized principals"); 603215116Sdes} 604215116Sdes 60598684Sdesstruct passwd * 60698684Sdesgetpwnamallow(const char *user) 60798684Sdes{ 60898684Sdes#ifdef HAVE_LOGIN_CAP 60998684Sdes extern login_cap_t *lc; 61098684Sdes#ifdef BSD_AUTH 61198684Sdes auth_session_t *as; 61298684Sdes#endif 61398684Sdes#endif 61498684Sdes struct passwd *pw; 615240075Sdes struct connection_info *ci = get_connection_info(1, options.use_dns); 61698684Sdes 617240075Sdes ci->user = user; 618240075Sdes parse_server_match_config(&options, ci); 619162856Sdes 620204917Sdes#if defined(_AIX) && defined(HAVE_SETAUTHDB) 621204917Sdes aix_setauthdb(user); 622204917Sdes#endif 623204917Sdes 62498684Sdes pw = getpwnam(user); 625204917Sdes 626204917Sdes#if defined(_AIX) && defined(HAVE_SETAUTHDB) 627204917Sdes aix_restoreauthdb(); 628204917Sdes#endif 629204917Sdes#ifdef HAVE_CYGWIN 630204917Sdes /* 631204917Sdes * Windows usernames are case-insensitive. To avoid later problems 632204917Sdes * when trying to match the username, the user is only allowed to 633204917Sdes * login if the username is given in the same case as stored in the 634204917Sdes * user database. 635204917Sdes */ 636204917Sdes if (pw != NULL && strcmp(user, pw->pw_name) != 0) { 637204917Sdes logit("Login name %.100s does not match stored username %.100s", 638204917Sdes user, pw->pw_name); 639204917Sdes pw = NULL; 640204917Sdes } 641204917Sdes#endif 642106130Sdes if (pw == NULL) { 643137019Sdes logit("Invalid user %.100s from %.100s", 644106130Sdes user, get_remote_ipaddr()); 645124211Sdes#ifdef CUSTOM_FAILED_LOGIN 646147005Sdes record_failed_login(user, 647147005Sdes get_canonical_hostname(options.use_dns), "ssh"); 648113911Sdes#endif 649147005Sdes#ifdef SSH_AUDIT_EVENTS 650147005Sdes audit_event(SSH_INVALID_USER); 651147005Sdes#endif /* SSH_AUDIT_EVENTS */ 65298684Sdes return (NULL); 653106130Sdes } 654106130Sdes if (!allowed_user(pw)) 655106130Sdes return (NULL); 65698684Sdes#ifdef HAVE_LOGIN_CAP 657100838Sfanf if ((lc = login_getpwclass(pw)) == NULL) { 65898684Sdes debug("unable to get login class: %s", user); 65998684Sdes return (NULL); 66098684Sdes } 66198684Sdes#ifdef BSD_AUTH 66298684Sdes if ((as = auth_open()) == NULL || auth_setpwd(as, pw) != 0 || 66398684Sdes auth_approval(as, lc, pw->pw_name, "ssh") <= 0) { 66498684Sdes debug("Approval failure for %s", user); 66598684Sdes pw = NULL; 66698684Sdes } 66798684Sdes if (as != NULL) 66898684Sdes auth_close(as); 66998684Sdes#endif 67098684Sdes#endif 67198684Sdes if (pw != NULL) 67298684Sdes return (pwcopy(pw)); 67398684Sdes return (NULL); 67498684Sdes} 67598684Sdes 676204917Sdes/* Returns 1 if key is revoked by revoked_keys_file, 0 otherwise */ 677204917Sdesint 678204917Sdesauth_key_is_revoked(Key *key) 679204917Sdes{ 680295367Sdes char *fp = NULL; 681295367Sdes int r; 682204917Sdes 683204917Sdes if (options.revoked_keys_file == NULL) 684204917Sdes return 0; 685295367Sdes if ((fp = sshkey_fingerprint(key, options.fingerprint_hash, 686295367Sdes SSH_FP_DEFAULT)) == NULL) { 687295367Sdes r = SSH_ERR_ALLOC_FAIL; 688295367Sdes error("%s: fingerprint key: %s", __func__, ssh_err(r)); 689295367Sdes goto out; 690295367Sdes } 691295367Sdes 692295367Sdes r = sshkey_check_revoked(key, options.revoked_keys_file); 693295367Sdes switch (r) { 694248619Sdes case 0: 695295367Sdes break; /* not revoked */ 696295367Sdes case SSH_ERR_KEY_REVOKED: 697295367Sdes error("Authentication key %s %s revoked by file %s", 698295367Sdes sshkey_type(key), fp, options.revoked_keys_file); 699295367Sdes goto out; 700248619Sdes default: 701295367Sdes error("Error checking authentication key %s %s in " 702295367Sdes "revoked keys file %s: %s", sshkey_type(key), fp, 703295367Sdes options.revoked_keys_file, ssh_err(r)); 704295367Sdes goto out; 705248619Sdes } 706295367Sdes 707295367Sdes /* Success */ 708295367Sdes r = 0; 709295367Sdes 710295367Sdes out: 711295367Sdes free(fp); 712295367Sdes return r == 0 ? 0 : 1; 713204917Sdes} 714204917Sdes 71598684Sdesvoid 71698684Sdesauth_debug_add(const char *fmt,...) 71798684Sdes{ 71898684Sdes char buf[1024]; 71998684Sdes va_list args; 72098684Sdes 72198684Sdes if (!auth_debug_init) 72298684Sdes return; 72398684Sdes 72498684Sdes va_start(args, fmt); 72598684Sdes vsnprintf(buf, sizeof(buf), fmt, args); 72698684Sdes va_end(args); 72798684Sdes buffer_put_cstring(&auth_debug, buf); 72898684Sdes} 72998684Sdes 73098684Sdesvoid 73198684Sdesauth_debug_send(void) 73298684Sdes{ 73398684Sdes char *msg; 73498684Sdes 73598684Sdes if (!auth_debug_init) 73698684Sdes return; 73798684Sdes while (buffer_len(&auth_debug)) { 73898684Sdes msg = buffer_get_string(&auth_debug, NULL); 73998684Sdes packet_send_debug("%s", msg); 740255767Sdes free(msg); 74198684Sdes } 74298684Sdes} 74398684Sdes 74498684Sdesvoid 74598684Sdesauth_debug_reset(void) 74698684Sdes{ 74798684Sdes if (auth_debug_init) 74898684Sdes buffer_clear(&auth_debug); 74998684Sdes else { 75098684Sdes buffer_init(&auth_debug); 75198684Sdes auth_debug_init = 1; 75298684Sdes } 75398684Sdes} 754124211Sdes 755124211Sdesstruct passwd * 756124211Sdesfakepw(void) 757124211Sdes{ 758124211Sdes static struct passwd fake; 759124211Sdes 760124211Sdes memset(&fake, 0, sizeof(fake)); 761124211Sdes fake.pw_name = "NOUSER"; 762124211Sdes fake.pw_passwd = 763126277Sdes "$2a$06$r3.juUaHZDlIbQaO2dS9FuYxL1W9M81R1Tc92PoSNmzvpEqLkLGrK"; 764255767Sdes#ifdef HAVE_STRUCT_PASSWD_PW_GECOS 765124211Sdes fake.pw_gecos = "NOUSER"; 766255767Sdes#endif 767181111Sdes fake.pw_uid = privsep_pw == NULL ? (uid_t)-1 : privsep_pw->pw_uid; 768181111Sdes fake.pw_gid = privsep_pw == NULL ? (gid_t)-1 : privsep_pw->pw_gid; 769255767Sdes#ifdef HAVE_STRUCT_PASSWD_PW_CLASS 770124211Sdes fake.pw_class = ""; 771124211Sdes#endif 772124211Sdes fake.pw_dir = "/nonexist"; 773124211Sdes fake.pw_shell = "/nonexist"; 774124211Sdes 775124211Sdes return (&fake); 776124211Sdes} 777