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/*
* $Source$
* $Author$
*
* Copyright 1989 by the Massachusetts Institute of Technology.
*
* For copying and distribution information, please see the file
* <mit-copyright.h>.
*
* Under U.S. law, this software may not be exported outside the US
* without license from the U.S. Commerce department.
*
* These routines form the library interface to the DES facilities.
*
* Originally written 8/85 by Steve Miller, MIT Project Athena.
*/
#ifndef lint
static char rcsid_weak_key_c[] =
"$Id$";
#endif
#include <des.h>
/*
* The following are the weak DES keys:
*/
static des_cblock weak[16] = {
/* weak keys */
{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
{0xfe,0xfe,0xfe,0xfe,0xfe,0xfe,0xfe,0xfe},
{0x1f,0x1f,0x1f,0x1f,0x0e,0x0e,0x0e,0x0e},
{0xe0,0xe0,0xe0,0xe0,0xf1,0xf1,0xf1,0xf1},
/* semi-weak */
{0x01,0xfe,0x01,0xfe,0x01,0xfe,0x01,0xfe},
{0xfe,0x01,0xfe,0x01,0xfe,0x01,0xfe,0x01},
{0x1f,0xe0,0x1f,0xe0,0x0e,0xf1,0x0e,0xf1},
{0xe0,0x1f,0xe0,0x1f,0xf1,0x0e,0xf1,0x0e},
{0x01,0xe0,0x01,0xe0,0x01,0xf1,0x01,0xf1},
{0xe0,0x01,0xe0,0x01,0xf1,0x01,0xf1,0x01},
{0x1f,0xfe,0x1f,0xfe,0x0e,0xfe,0x0e,0xfe},
{0xfe,0x1f,0xfe,0x1f,0xfe,0x0e,0xfe,0x0e},
{0x01,0x1f,0x01,0x1f,0x01,0x0e,0x01,0x0e},
{0x1f,0x01,0x1f,0x01,0x0e,0x01,0x0e,0x01},
{0xe0,0xfe,0xe0,0xfe,0xf1,0xfe,0xf1,0xfe},
{0xfe,0xe0,0xfe,0xe0,0xfe,0xf1,0xfe,0xf1}
};
/*
* des_is_weak_key: returns true iff key is a [semi-]weak des key.
*
* Requires: key has correct odd parity.
*/
int
des_is_weak_key(key)
des_cblock key;
{
int i;
des_cblock *weak_p = weak;
for (i = 0; i < (sizeof(weak)/sizeof(des_cblock)); i++) {
if (!memcmp((char *)weak_p++, (char *)key, sizeof(des_cblock)))
return 1;
}
return 0;
}
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