crypt/crypt-entry.c

   1 /*
   2  * UFC-crypt: ultra fast crypt(3) implementation
   3  *
   4  * Copyright (C) 1991-2015 Free Software Foundation, Inc.
   5  *
   6  * The GNU C Library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * The GNU C Library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with the GNU C Library; if not, see
  18  * <http://www.gnu.org/licenses/>.
  19  *
  20  * crypt entry points
  21  *
  22  * @(#)crypt-entry.c    1.2 12/20/96
  23  *
  24  */
  25
  26 #ifdef DEBUG
  27 #include <stdio.h>
  28 #endif
  29 #include <string.h>
  30 #include <errno.h>
  31 #include <fips-private.h>
  32
  33 #ifndef STATIC
  34 #define STATIC static
  35 #endif
  36
  37 #include "crypt-private.h"
  38
  39 /* Prototypes for local functions.  */
  40 #ifndef __GNU_LIBRARY__
  41 void _ufc_clearmem (char *start, int cnt);
  42 #else
  43 #define _ufc_clearmem(start, cnt)   memset(start, 0, cnt)
  44 #endif
  45 extern char *__md5_crypt_r (const char *key, const char *salt, char *buffer,
  46                             int buflen);
  47 extern char *__md5_crypt (const char *key, const char *salt);
  48 extern char *__sha256_crypt_r (const char *key, const char *salt,
  49                                char *buffer, int buflen);
  50 extern char *__sha256_crypt (const char *key, const char *salt);
  51 extern char *__sha512_crypt_r (const char *key, const char *salt,
  52                                char *buffer, int buflen);
  53 extern char *__sha512_crypt (const char *key, const char *salt);
  54
  55 /* Define our magic string to mark salt for MD5 encryption
  56    replacement.  This is meant to be the same as for other MD5 based
  57    encryption implementations.  */
  58 static const char md5_salt_prefix[] = "$1$";
  59
  60 /* Magic string for SHA256 encryption.  */
  61 static const char sha256_salt_prefix[] = "$5$";
  62
  63 /* Magic string for SHA512 encryption.  */
  64 static const char sha512_salt_prefix[] = "$6$";
  65
  66 /* For use by the old, non-reentrant routines (crypt/encrypt/setkey)  */
  67 extern struct crypt_data _ufc_foobar;
  68
  69 /*
  70  * UNIX crypt function
  71  */
  72
  73 char *
  74 __crypt_r (key, salt, data)
  75      const char *key;
  76      const char *salt;
  77      struct crypt_data * __restrict data;
  78 {
  79   ufc_long res[4];
  80   char ktab[9];
  81   ufc_long xx = 25; /* to cope with GCC long long compiler bugs */
  82
  83 #ifdef _LIBC
  84   /* Try to find out whether we have to use MD5 encryption replacement.  */
  85   if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0)
  86     {
  87       /* FIPS rules out MD5 password encryption.  */
  88       if (fips_enabled_p ())
  89         {
  90           __set_errno (EPERM);
  91           return NULL;
  92         }
  93       return __md5_crypt_r (key, salt, (char *) data,
  94                             sizeof (struct crypt_data));
  95     }
  96
  97   /* Try to find out whether we have to use SHA256 encryption replacement.  */
  98   if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
  99     return __sha256_crypt_r (key, salt, (char *) data,
 100                              sizeof (struct crypt_data));
 101
 102   /* Try to find out whether we have to use SHA512 encryption replacement.  */
 103   if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
 104     return __sha512_crypt_r (key, salt, (char *) data,
 105                              sizeof (struct crypt_data));
 106 #endif
 107
 108   /*
 109    * Hack DES tables according to salt
 110    */
 111   if (!_ufc_setup_salt_r (salt, data))
 112     {
 113       __set_errno (EINVAL);
 114       return NULL;
 115     }
 116
 117   /* FIPS rules out DES password encryption.  */
 118   if (fips_enabled_p ())
 119     {
 120       __set_errno (EPERM);
 121       return NULL;
 122     }
 123
 124   /*
 125    * Setup key schedule
 126    */
 127   _ufc_clearmem (ktab, (int) sizeof (ktab));
 128   (void) strncpy (ktab, key, 8);
 129   _ufc_mk_keytab_r (ktab, data);
 130
 131   /*
 132    * Go for the 25 DES encryptions
 133    */
 134   _ufc_clearmem ((char*) res, (int) sizeof (res));
 135   _ufc_doit_r (xx,  data, &res[0]);
 136
 137   /*
 138    * Do final permutations
 139    */
 140   _ufc_dofinalperm_r (res, data);
 141
 142   /*
 143    * And convert back to 6 bit ASCII
 144    */
 145   _ufc_output_conversion_r (res[0], res[1], salt, data);
 146   return data->crypt_3_buf;
 147 }
 148 weak_alias (__crypt_r, crypt_r)
 149
 150 char *
 151 crypt (key, salt)
 152      const char *key;
 153      const char *salt;
 154 {
 155 #ifdef _LIBC
 156   /* Try to find out whether we have to use MD5 encryption replacement.  */
 157   if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0
 158       /* Let __crypt_r deal with the error code if FIPS is enabled.  */
 159       && !fips_enabled_p ())
 160     return __md5_crypt (key, salt);
 161
 162   /* Try to find out whether we have to use SHA256 encryption replacement.  */
 163   if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
 164     return __sha256_crypt (key, salt);
 165
 166   /* Try to find out whether we have to use SHA512 encryption replacement.  */
 167   if (strncmp (sha512_salt_prefix, salt, sizeof (sha512_salt_prefix) - 1) == 0)
 168     return __sha512_crypt (key, salt);
 169 #endif
 170
 171   return __crypt_r (key, salt, &_ufc_foobar);
 172 }
 173
 174
 175 /*
 176  * To make fcrypt users happy.
 177  * They don't need to call init_des.
 178  */
 179 #ifdef _LIBC
 180 weak_alias (crypt, fcrypt)
 181 #else
 182 char *
 183 __fcrypt (key, salt)
 184      const char *key;
 185      const char *salt;
 186 {
 187   return crypt (key, salt);
 188 }
 189 #endif