home *** CD-ROM | disk | FTP | other *** search
/ InfoMagic Source Code 1993 July / THE_SOURCE_CODE_CD_ROM.iso / bsd_srcs / kerberosIV / des / weak_key.c < prev    next >
Encoding:
C/C++ Source or Header  |  1989-01-22  |  1.9 KB  |  75 lines
  1. /*
  2.  * $Source: /mit/kerberos/src/lib/des/RCS/weak_key.c,v $
  3.  * $Author: jtkohl $
  4.  *
  5.  * Copyright 1989 by the Massachusetts Institute of Technology.
  6.  *
  7.  * For copying and distribution information, please see the file
  8.  * <mit-copyright.h>.
  9.  *
  10.  * Under U.S. law, this software may not be exported outside the US
  11.  * without license from the U.S. Commerce department.
  12.  *
  13.  * These routines form the library interface to the DES facilities.
  14.  *
  15.  * Originally written 8/85 by Steve Miller, MIT Project Athena.
  16.  */
  17.  
  18. #ifndef    lint
  19. static char rcsid_weak_key_c[] =
  20. "$Header: weak_key.c,v 4.3 89/01/22 12:16:41 jtkohl Exp $";
  21. #endif    lint
  22.  
  23. #include <des.h>
  24. #include "des_internal.h"
  25.  
  26. /*
  27.  * The following are the weak DES keys:
  28.  */
  29. static des_cblock weak[16] = {
  30.     /* weak keys */
  31.     {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
  32.     {0xfe,0xfe,0xfe,0xfe,0xfe,0xfe,0xfe,0xfe},
  33.     {0x1f,0x1f,0x1f,0x1f,0x0e,0x0e,0x0e,0x0e},
  34.     {0xe0,0xe0,0xe0,0xe0,0xf1,0xf1,0xf1,0xf1},
  35.  
  36.     /* semi-weak */
  37.     {0x01,0xfe,0x01,0xfe,0x01,0xfe,0x01,0xfe},
  38.     {0xfe,0x01,0xfe,0x01,0xfe,0x01,0xfe,0x01},
  39.  
  40.     {0x1f,0xe0,0x1f,0xe0,0x0e,0xf1,0x0e,0xf1},
  41.     {0xe0,0x1f,0xe0,0x1f,0xf1,0x0e,0xf1,0x0e},
  42.  
  43.     {0x01,0xe0,0x01,0xe0,0x01,0xf1,0x01,0xf1},
  44.     {0xe0,0x01,0xe0,0x01,0xf1,0x01,0xf1,0x01},
  45.  
  46.     {0x1f,0xfe,0x1f,0xfe,0x0e,0xfe,0x0e,0xfe},
  47.     {0xfe,0x1f,0xfe,0x1f,0xfe,0x0e,0xfe,0x0e},
  48.  
  49.     {0x01,0x1f,0x01,0x1f,0x01,0x0e,0x01,0x0e},
  50.     {0x1f,0x01,0x1f,0x01,0x0e,0x01,0x0e,0x01},
  51.  
  52.     {0xe0,0xfe,0xe0,0xfe,0xf1,0xfe,0xf1,0xfe},
  53.     {0xfe,0xe0,0xfe,0xe0,0xfe,0xf1,0xfe,0xf1}
  54. };
  55.  
  56. /*
  57.  * des_is_weak_key: returns true iff key is a [semi-]weak des key.
  58.  *
  59.  * Requires: key has correct odd parity.
  60.  */
  61. int
  62. des_is_weak_key(key)
  63.      des_cblock key;
  64. {
  65.     int i;
  66.     des_cblock *weak_p = weak;
  67.  
  68.     for (i = 0; i < (sizeof(weak)/sizeof(des_cblock)); i++) {
  69.     if (!bcmp((char *)weak_p++,(char *)key,sizeof(des_cblock)))
  70.         return 1;
  71.     }
  72.  
  73.     return 0;
  74. }
  75.