src/TortoiseMerge/libsvn_diff/md5.c

   1 /*
   2  * md5.c:   checksum routines
   3  *
   4  * ====================================================================
   5  * Copyright (c) 2000-2004, 2008 CollabNet.  All rights reserved.
   6  *
   7  * This software is licensed as described in the file COPYING, which
   8  * you should have received as part of this distribution.  The terms
   9  * are also available at http://subversion.tigris.org/license-1.html.
  10  * If newer versions of this license are posted there, you may use a
  11  * newer version instead, at your option.
  12  *
  13  * This software consists of voluntary contributions made by many
  14  * individuals.  For exact contribution history, see the revision
  15  * history and logs, available at http://subversion.tigris.org/.
  16  * ====================================================================
  17  */
  18
  19
  20 #include <apr_md5.h>
  21 #include "md5.h"
  22 #include "svn_md5.h"
  23
  24 \f
  25
  26 /* The MD5 digest for the empty string. */
  27 static const unsigned char svn_md5__empty_string_digest_array[] = {
  28   212, 29, 140, 217, 143, 0, 178, 4, 233, 128, 9, 152, 236, 248, 66, 126
  29 };
  30
  31 const unsigned char *
  32 svn_md5__empty_string_digest(void)
  33 {
  34   return svn_md5__empty_string_digest_array;
  35 }
  36
  37
  38 const char *
  39 svn_md5__digest_to_cstring_display(const unsigned char digest[],
  40                                    apr_pool_t *pool)
  41 {
  42   static const char *hex = "0123456789abcdef";
  43   char *str = apr_palloc(pool, (APR_MD5_DIGESTSIZE * 2) + 1);
  44   int i;
  45
  46   for (i = 0; i < APR_MD5_DIGESTSIZE; i++)
  47     {
  48       str[i*2]   = hex[digest[i] >> 4];
  49       str[i*2+1] = hex[digest[i] & 0x0f];
  50     }
  51   str[i*2] = '\0';
  52
  53   return str;
  54 }
  55
  56
  57 const char *
  58 svn_md5__digest_to_cstring(const unsigned char digest[], apr_pool_t *pool)
  59 {
  60   static const unsigned char zeros_digest[APR_MD5_DIGESTSIZE] = { 0 };
  61
  62   if (memcmp(digest, zeros_digest, APR_MD5_DIGESTSIZE) != 0)
  63     return svn_md5__digest_to_cstring_display(digest, pool);
  64   else
  65     return NULL;
  66 }
  67
  68
  69 svn_boolean_t
  70 svn_md5__digests_match(const unsigned char d1[], const unsigned char d2[])
  71 {
  72   static const unsigned char zeros[APR_MD5_DIGESTSIZE] = { 0 };
  73
  74   return ((memcmp(d1, zeros, APR_MD5_DIGESTSIZE) == 0)
  75           || (memcmp(d2, zeros, APR_MD5_DIGESTSIZE) == 0)
  76           || (memcmp(d1, d2, APR_MD5_DIGESTSIZE) == 0));
  77 }
  78
  79 /* These are all deprecated, and just wrap the internal functions defined
  80    above. */
  81 const unsigned char *
  82 svn_md5_empty_string_digest(void)
  83 {
  84   return svn_md5__empty_string_digest();
  85 }
  86
  87 const char *
  88 svn_md5_digest_to_cstring_display(const unsigned char digest[],
  89                                   apr_pool_t *pool)
  90 {
  91   return svn_md5__digest_to_cstring_display(digest, pool);
  92 }
  93
  94 const char *
  95 svn_md5_digest_to_cstring(const unsigned char digest[], apr_pool_t *pool)
  96 {
  97   return svn_md5__digest_to_cstring(digest, pool);
  98 }
  99
 100 svn_boolean_t
 101 svn_md5_digests_match(const unsigned char d1[], const unsigned char d2[])
 102 {
 103   return svn_md5__digests_match(d1, d2);
 104 }