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225 lines
6.4 KiB
225 lines
6.4 KiB
/* $OpenBSD: auth-passwd.c,v 1.45 2016/07/21 01:39:35 dtucker Exp $ */ |
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/* |
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* Author: Tatu Ylonen <ylo@cs.hut.fi> |
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
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* All rights reserved |
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* Password authentication. This file contains the functions to check whether |
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* the password is valid for the user. |
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* |
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* As far as I am concerned, the code I have written for this software |
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* can be used freely for any purpose. Any derived versions of this |
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* software must be clearly marked as such, and if the derived work is |
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* incompatible with the protocol description in the RFC file, it must be |
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* called by a name other than "ssh" or "Secure Shell". |
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* |
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* Copyright (c) 1999 Dug Song. All rights reserved. |
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* Copyright (c) 2000 Markus Friedl. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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#include "includes.h" |
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#include <sys/types.h> |
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#include <pwd.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <stdarg.h> |
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#include "packet.h" |
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#include "buffer.h" |
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#include "log.h" |
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#include "misc.h" |
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#include "servconf.h" |
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#include "key.h" |
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#include "hostfile.h" |
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#include "auth.h" |
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#include "auth-options.h" |
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extern Buffer loginmsg; |
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extern ServerOptions options; |
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#ifdef HAVE_LOGIN_CAP |
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extern login_cap_t *lc; |
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#endif |
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#define DAY (24L * 60 * 60) /* 1 day in seconds */ |
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#define TWO_WEEKS (2L * 7 * DAY) /* 2 weeks in seconds */ |
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#define MAX_PASSWORD_LEN 1024 |
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void |
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disable_forwarding(void) |
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{ |
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no_port_forwarding_flag = 1; |
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no_agent_forwarding_flag = 1; |
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no_x11_forwarding_flag = 1; |
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} |
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/* |
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* Tries to authenticate the user using password. Returns true if |
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* authentication succeeds. |
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*/ |
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int |
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auth_password(Authctxt *authctxt, const char *password) |
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{ |
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struct passwd * pw = authctxt->pw; |
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int result, ok = authctxt->valid; |
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#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) |
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static int expire_checked = 0; |
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#endif |
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if (strlen(password) > MAX_PASSWORD_LEN) |
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return 0; |
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#ifndef HAVE_CYGWIN |
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if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES) |
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ok = 0; |
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#endif |
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if (*password == '\0' && options.permit_empty_passwd == 0) |
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return 0; |
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#ifdef KRB5 |
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if (options.kerberos_authentication == 1) { |
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int ret = auth_krb5_password(authctxt, password); |
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if (ret == 1 || ret == 0) |
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return ret && ok; |
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/* Fall back to ordinary passwd authentication. */ |
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} |
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#endif |
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#ifdef HAVE_CYGWIN |
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{ |
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HANDLE hToken = cygwin_logon_user(pw, password); |
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if (hToken == INVALID_HANDLE_VALUE) |
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return 0; |
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cygwin_set_impersonation_token(hToken); |
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return ok; |
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} |
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#endif |
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#ifdef USE_PAM |
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if (options.use_pam) |
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return (sshpam_auth_passwd(authctxt, password) && ok); |
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#endif |
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#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE) |
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if (!expire_checked) { |
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expire_checked = 1; |
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if (auth_shadow_pwexpired(authctxt)) |
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authctxt->force_pwchange = 1; |
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} |
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#endif |
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result = sys_auth_passwd(authctxt, password); |
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if (authctxt->force_pwchange) |
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disable_forwarding(); |
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return (result && ok); |
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} |
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#ifdef BSD_AUTH |
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static void |
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warn_expiry(Authctxt *authctxt, auth_session_t *as) |
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{ |
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char buf[256]; |
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quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime; |
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pwwarntime = acwarntime = TWO_WEEKS; |
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pwtimeleft = auth_check_change(as); |
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actimeleft = auth_check_expire(as); |
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#ifdef HAVE_LOGIN_CAP |
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if (authctxt->valid) { |
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pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS, |
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TWO_WEEKS); |
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acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS, |
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TWO_WEEKS); |
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} |
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#endif |
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if (pwtimeleft != 0 && pwtimeleft < pwwarntime) { |
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daysleft = pwtimeleft / DAY + 1; |
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snprintf(buf, sizeof(buf), |
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"Your password will expire in %lld day%s.\n", |
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daysleft, daysleft == 1 ? "" : "s"); |
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buffer_append(&loginmsg, buf, strlen(buf)); |
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} |
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if (actimeleft != 0 && actimeleft < acwarntime) { |
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daysleft = actimeleft / DAY + 1; |
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snprintf(buf, sizeof(buf), |
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"Your account will expire in %lld day%s.\n", |
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daysleft, daysleft == 1 ? "" : "s"); |
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buffer_append(&loginmsg, buf, strlen(buf)); |
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} |
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} |
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int |
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sys_auth_passwd(Authctxt *authctxt, const char *password) |
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{ |
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struct passwd *pw = authctxt->pw; |
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auth_session_t *as; |
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static int expire_checked = 0; |
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as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh", |
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(char *)password); |
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if (as == NULL) |
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return (0); |
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if (auth_getstate(as) & AUTH_PWEXPIRED) { |
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auth_close(as); |
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disable_forwarding(); |
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authctxt->force_pwchange = 1; |
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return (1); |
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} else { |
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if (!expire_checked) { |
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expire_checked = 1; |
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warn_expiry(authctxt, as); |
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} |
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return (auth_close(as)); |
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} |
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} |
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#elif !defined(CUSTOM_SYS_AUTH_PASSWD) |
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int |
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sys_auth_passwd(Authctxt *authctxt, const char *password) |
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{ |
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struct passwd *pw = authctxt->pw; |
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char *encrypted_password, *salt = NULL; |
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/* Just use the supplied fake password if authctxt is invalid */ |
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char *pw_password = authctxt->valid ? shadow_pw(pw) : pw->pw_passwd; |
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/* Check for users with no password. */ |
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if (strcmp(pw_password, "") == 0 && strcmp(password, "") == 0) |
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return (1); |
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/* |
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* Encrypt the candidate password using the proper salt, or pass a |
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* NULL and let xcrypt pick one. |
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*/ |
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if (authctxt->valid && pw_password[0] && pw_password[1]) |
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salt = pw_password; |
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encrypted_password = xcrypt(password, salt); |
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/* |
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* Authentication is accepted if the encrypted passwords |
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* are identical. |
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*/ |
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return encrypted_password != NULL && |
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strcmp(encrypted_password, pw_password) == 0; |
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} |
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#endif
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