crypto/external/bsd/openssh/dist/auth-passwd.c

   1 /*      $NetBSD$        */
   2 /* $OpenBSD: auth-passwd.c,v 1.43 2007/09/21 08:15:29 djm Exp $ */
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * Password authentication.  This file contains the functions to check whether
   8  * the password is valid for the user.
   9  *
  10  * As far as I am concerned, the code I have written for this software
  11  * can be used freely for any purpose.  Any derived versions of this
  12  * software must be clearly marked as such, and if the derived work is
  13  * incompatible with the protocol description in the RFC file, it must be
  14  * called by a name other than "ssh" or "Secure Shell".
  15  *
  16  * Copyright (c) 1999 Dug Song.  All rights reserved.
  17  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  18  *
  19  * Redistribution and use in source and binary forms, with or without
  20  * modification, are permitted provided that the following conditions
  21  * are met:
  22  * 1. Redistributions of source code must retain the above copyright
  23  *    notice, this list of conditions and the following disclaimer.
  24  * 2. Redistributions in binary form must reproduce the above copyright
  25  *    notice, this list of conditions and the following disclaimer in the
  26  *    documentation and/or other materials provided with the distribution.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  29  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  30  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  31  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  32  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  33  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  37  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  */
  39
  40 #include "includes.h"
  41 __RCSID("$NetBSD: auth-passwd.c,v 1.17 2008/04/06 23:38:19 christos Exp $");
  42 #include <sys/types.h>
  43
  44 #include <login_cap.h>
  45 #include <pwd.h>
  46 #include <stdio.h>
  47 #include <string.h>
  48 #include <stdarg.h>
  49 #include <unistd.h>
  50
  51 #include "packet.h"
  52 #include "buffer.h"
  53 #include "log.h"
  54 #include "servconf.h"
  55 #include "key.h"
  56 #include "hostfile.h"
  57 #include "auth.h"
  58 #include "auth-options.h"
  59
  60 extern Buffer loginmsg;
  61 extern ServerOptions options;
  62 int sys_auth_passwd(Authctxt *, const char *);
  63
  64 #ifdef HAVE_LOGIN_CAP
  65 extern login_cap_t *lc;
  66 #endif
  67
  68 #define DAY             (24L * 60 * 60) /* 1 day in seconds */
  69 #define TWO_WEEKS       (2L * 7 * DAY)  /* 2 weeks in seconds */
  70
  71 #if defined(BSD_AUTH) || defined(USE_PAM)
  72 void
  73 disable_forwarding(void)
  74 {
  75         no_port_forwarding_flag = 1;
  76         no_agent_forwarding_flag = 1;
  77         no_x11_forwarding_flag = 1;
  78 }
  79 #endif
  80
  81 /*
  82  * Tries to authenticate the user using password.  Returns true if
  83  * authentication succeeds.
  84  */
  85 int
  86 auth_password(Authctxt *authctxt, const char *password)
  87 {
  88         struct passwd * pw = authctxt->pw;
  89         int ok = authctxt->valid;
  90
  91         if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
  92                 ok = 0;
  93         if (*password == '\0' && options.permit_empty_passwd == 0)
  94                 return 0;
  95 #ifdef USE_PAM
  96         if (options.use_pam)
  97                 return (sshpam_auth_passwd(authctxt, password) && ok);
  98 #endif
  99 #ifdef KRB5
 100         if (options.kerberos_authentication == 1) {
 101                 int ret = auth_krb5_password(authctxt, password);
 102                 if (ret == 1 || ret == 0)
 103                         return ret && ok;
 104                 /* Fall back to ordinary passwd authentication. */
 105         }
 106 #endif
 107         return (sys_auth_passwd(authctxt, password) && ok);
 108 }
 109
 110 #ifdef BSD_AUTH
 111 static void
 112 warn_expiry(Authctxt *authctxt, auth_session_t *as)
 113 {
 114         char buf[256];
 115         quad_t pwtimeleft, actimeleft, daysleft, pwwarntime, acwarntime;
 116
 117         pwwarntime = acwarntime = TWO_WEEKS;
 118
 119         pwtimeleft = auth_check_change(as);
 120         actimeleft = auth_check_expire(as);
 121 #ifdef HAVE_LOGIN_CAP
 122         if (authctxt->valid) {
 123                 pwwarntime = login_getcaptime(lc, "password-warn", TWO_WEEKS,
 124                     TWO_WEEKS);
 125                 acwarntime = login_getcaptime(lc, "expire-warn", TWO_WEEKS,
 126                     TWO_WEEKS);
 127         }
 128 #endif
 129         if (pwtimeleft != 0 && pwtimeleft < pwwarntime) {
 130                 daysleft = pwtimeleft / DAY + 1;
 131                 snprintf(buf, sizeof(buf),
 132                     "Your password will expire in %lld day%s.\n",
 133                     daysleft, daysleft == 1 ? "" : "s");
 134                 buffer_append(&loginmsg, buf, strlen(buf));
 135         }
 136         if (actimeleft != 0 && actimeleft < acwarntime) {
 137                 daysleft = actimeleft / DAY + 1;
 138                 snprintf(buf, sizeof(buf),
 139                     "Your account will expire in %lld day%s.\n",
 140                     daysleft, daysleft == 1 ? "" : "s");
 141                 buffer_append(&loginmsg, buf, strlen(buf));
 142         }
 143 }
 144
 145 int
 146 sys_auth_passwd(Authctxt *authctxt, const char *password)
 147 {
 148         struct passwd *pw = authctxt->pw;
 149         auth_session_t *as;
 150         static int expire_checked = 0;
 151
 152         as = auth_usercheck(pw->pw_name, authctxt->style, "auth-ssh",
 153             (char *)password);
 154         if (as == NULL)
 155                 return (0);
 156         if (auth_getstate(as) & AUTH_PWEXPIRED) {
 157                 auth_close(as);
 158                 disable_forwarding();
 159                 authctxt->force_pwchange = 1;
 160                 return (1);
 161         } else {
 162                 if (!expire_checked) {
 163                         expire_checked = 1;
 164                         warn_expiry(authctxt, as);
 165                 }
 166                 return (auth_close(as));
 167         }
 168 }
 169 #else
 170 int
 171 sys_auth_passwd(Authctxt *authctxt, const char *password)
 172 {
 173         struct passwd *pw = authctxt->pw;
 174         char *encrypted_password;
 175
 176         /* Check for users with no password. */
 177         if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0)
 178                 return (1);
 179
 180         /* Encrypt the candidate password using the proper salt. */
 181         encrypted_password = crypt(password,
 182             (pw->pw_passwd[0] && pw->pw_passwd[1]) ?
 183             pw->pw_passwd : "xx");
 184
 185         /*
 186          * Authentication is accepted if the encrypted passwords
 187          * are identical.
 188          */
 189         return (strcmp(encrypted_password, pw->pw_passwd) == 0);
 190 }
 191 #endif