d4af9e693f
I have worked hard to reduce diffs against the vendor branch. One notable change in that respect is that we no longer prefer DSA over RSA - the reasons for doing so went away years ago. This may cause some surprises, as ssh will warn about unknown host keys even for hosts whose keys haven't changed. MFC after: 6 weeks
215 lines
6.2 KiB
C
215 lines
6.2 KiB
C
/* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm 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 "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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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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#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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if (is_winnt) {
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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;
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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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/* Encrypt the candidate password using the proper salt. */
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encrypted_password = xcrypt(password,
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(pw_password[0] && pw_password[1]) ? pw_password : "xx");
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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 (strcmp(encrypted_password, pw_password) == 0);
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}
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#endif
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