md5/redhat-crypt-md5.c

   1 /*
   2 ** Copyright 1998 - 1999 Double Precision, Inc.
   3 ** See COPYING for distribution information.
   4 */
   5
   6 #define MD5_INTERNAL
   7 #include        "md5.h"
   8 #include        <string.h>
   9
  10 static const char rcsid[]="$Id: redhat-crypt-md5.c,v 1.3 1999/12/06 13:22:43 mrsam Exp $";
  11
  12 static char base64[]=
  13         "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
  14
  15 char *md5_crypt_redhat(const char *pw, const char *salt)
  16 {
  17 struct MD5_CONTEXT outer_context, inner_context;
  18 MD5_DIGEST digest;
  19 unsigned pwl=strlen(pw);
  20 unsigned l;
  21 unsigned i, j;
  22 char    *p;
  23 static char buffer[100];
  24
  25         if (*salt == '$' && salt[1] == '1' && salt[2] == '$')
  26                 salt += 3;
  27
  28         for (l=0; l<8 && salt[l] && salt[l] != '$'; l++)
  29                 ;
  30
  31         md5_context_init(&inner_context);
  32         md5_context_hashstream(&inner_context, pw, pwl);
  33         md5_context_hashstream(&inner_context, salt, l);
  34         md5_context_hashstream(&inner_context, pw, pwl);
  35         md5_context_endstream(&inner_context, pwl*2+l);
  36         md5_context_digest(&inner_context, digest);
  37
  38         md5_context_init(&outer_context);
  39         md5_context_hashstream(&outer_context, pw, pwl);
  40         md5_context_hashstream(&outer_context, "$1$", 3);
  41         md5_context_hashstream(&outer_context, salt, l);
  42
  43         for (i=pwl; i; )
  44         {
  45                 j=i;
  46                 if (j > 16)     j=16;
  47                 md5_context_hashstream(&outer_context, digest, j);
  48                 i -= j;
  49         }
  50
  51         j=pwl*2+l+3;
  52
  53         for (i=pwl; i; i >>= 1)
  54         {
  55                 md5_context_hashstream(&outer_context, (i & 1) ? "": pw, 1);
  56                 ++j;
  57         }
  58
  59
  60         md5_context_endstream(&outer_context, j);
  61         md5_context_digest(&outer_context, digest);
  62
  63         for (i=0; i<1000; i++)
  64         {
  65                 j=0;
  66
  67                 md5_context_init(&outer_context);
  68                 if (i & 1)
  69                 {
  70                         md5_context_hashstream(&outer_context, pw, pwl);
  71                         j += pwl;
  72                 }
  73                 else
  74                 {
  75                         md5_context_hashstream(&outer_context, digest, 16);
  76                         j += 16;
  77                 }
  78
  79                 if (i % 3)
  80                 {
  81                         md5_context_hashstream(&outer_context, salt, l);
  82                         j += l;
  83                 }
  84
  85                 if (i % 7)
  86                 {
  87                         md5_context_hashstream(&outer_context, pw, pwl);
  88                         j += pwl;
  89                 }
  90
  91                 if (i & 1)
  92                 {
  93                         md5_context_hashstream(&outer_context, digest, 16);
  94                         j += 16;
  95                 }
  96                 else
  97                 {
  98                         md5_context_hashstream(&outer_context, pw, pwl);
  99                         j += pwl;
 100                 }
 101
 102                 md5_context_endstream(&outer_context, j);
 103                 md5_context_digest(&outer_context, digest);
 104         }
 105
 106         strcpy(buffer, "$1$");
 107         strncat(buffer, salt, l);
 108         strcat(buffer, "$");
 109
 110         p=buffer+strlen(buffer);
 111         for (i=0; i<5; i++)
 112         {
 113         unsigned char *d=digest;
 114
 115                 j= (d[i] << 16) | (d[i+6] << 8) | d[i == 4 ? 5:12+i];
 116                 *p++= base64[j & 63] ; j=j >> 6;
 117                 *p++= base64[j & 63] ; j=j >> 6;
 118                 *p++= base64[j & 63] ; j=j >> 6;
 119                 *p++= base64[j & 63];
 120         }
 121         j=digest[11];
 122         *p++ = base64[j & 63]; j=j >> 6;
 123         *p++ = base64[j & 63];
 124         *p=0;
 125         return (buffer);
 126 }