auth-passwd.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Created: Sat Mar 18 05:11:38 1995 ylo
   6  * Password authentication.  This file contains the functions to check whether
   7  * the password is valid for the user.
   8  */
   9
  10 #include "includes.h"
  11
  12 #ifndef USE_PAM
  13
  14 RCSID("$Id$");
  15
  16 #include "packet.h"
  17 #include "ssh.h"
  18 #include "servconf.h"
  19 #include "xmalloc.h"
  20
  21 #ifdef WITH_AIXAUTHENTICATE
  22 # include <login.h>
  23 #endif
  24 #ifdef HAVE_HPUX_TRUSTED_SYSTEM_PW
  25 # include <hpsecurity.h>
  26 # include <prot.h>
  27 #endif
  28 #ifdef HAVE_SHADOW_H
  29 # include <shadow.h>
  30 #endif
  31 #if defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT)
  32 # include "md5crypt.h"
  33 #endif /* defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT) */
  34
  35 /*
  36  * Tries to authenticate the user using password.  Returns true if
  37  * authentication succeeds.
  38  */
  39 int
  40 auth_password(struct passwd * pw, const char *password)
  41 {
  42         extern ServerOptions options;
  43         char *encrypted_password;
  44         char *pw_password;
  45         char *salt;
  46 #ifdef HAVE_SHADOW_H
  47         struct spwd *spw;
  48 #endif
  49 #ifdef WITH_AIXAUTHENTICATE
  50         char *authmsg;
  51         char *loginmsg;
  52         int reenter = 1;
  53 #endif
  54
  55         /* deny if no user. */
  56         if (pw == NULL)
  57                 return 0;
  58         if (pw->pw_uid == 0 && options.permit_root_login == 2)
  59                 return 0;
  60         if (*password == '\0' && options.permit_empty_passwd == 0)
  61                 return 0;
  62
  63 #ifdef SKEY
  64         if (options.skey_authentication == 1) {
  65                 int ret = auth_skey_password(pw, password);
  66                 if (ret == 1 || ret == 0)
  67                         return ret;
  68                 /* Fall back to ordinary passwd authentication. */
  69         }
  70 #endif
  71
  72 #ifdef WITH_AIXAUTHENTICATE
  73         return (authenticate(pw->pw_name,password,&reenter,&authmsg) == 0);
  74 #endif
  75
  76 #ifdef KRB4
  77         if (options.kerberos_authentication == 1) {
  78                 int ret = auth_krb4_password(pw, password);
  79                 if (ret == 1 || ret == 0)
  80                         return ret;
  81                 /* Fall back to ordinary passwd authentication. */
  82         }
  83 #endif
  84
  85         /* Check for users with no password. */
  86         if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0)
  87                 return 1;
  88
  89         pw_password = pw->pw_passwd;
  90
  91 #if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
  92         spw = getspnam(pw->pw_name);
  93         if (spw != NULL)
  94         {
  95                 /* Check for users with no password. */
  96                 if (strcmp(password, "") == 0 && strcmp(spw->sp_pwdp, "") == 0)
  97                         return 1;
  98
  99                 pw_password = spw->sp_pwdp;
 100         }
 101 #endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */
 102
 103         if (pw_password[0] != '\0')
 104                 salt = pw_password;
 105         else
 106                 salt = "xx";
 107
 108 #ifdef HAVE_MD5_PASSWORDS
 109         if (is_md5_salt(salt))
 110                 encrypted_password = md5_crypt(password, salt);
 111         else
 112                 encrypted_password = crypt(password, salt);
 113 #else /* HAVE_MD5_PASSWORDS */
 114 # ifdef HAVE_HPUX_TRUSTED_SYSTEM_PW
 115         encrypted_password = bigcrypt(password, salt);
 116 # else
 117         encrypted_password = crypt(password, salt);
 118 # endif /* HAVE_HPUX_TRUSTED_SYSTEM_PW */
 119 #endif /* HAVE_MD5_PASSWORDS */
 120
 121         /* Authentication is accepted if the encrypted passwords are identical. */
 122         return (strcmp(encrypted_password, pw_password) == 0);
 123 }
 124 #endif /* !USE_PAM */