78 lines
1.4 KiB
C
78 lines
1.4 KiB
C
/*
|
|
* This file is part of the UCB release of Plan 9. It is subject to the license
|
|
* terms in the LICENSE file found in the top-level directory of this
|
|
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
|
|
* part of the UCB release of Plan 9, including this file, may be copied,
|
|
* modified, propagated, or distributed except according to the terms contained
|
|
* in the LICENSE file.
|
|
*/
|
|
|
|
/*
|
|
* Data Encryption Standard
|
|
* D.P.Mitchell 83/06/08.
|
|
*
|
|
* block_cipher(key, block, decrypting)
|
|
*
|
|
* these routines use the non-standard 7 byte format
|
|
* for DES keys.
|
|
*/
|
|
#include <u.h>
|
|
#include <libc.h>
|
|
#include <auth.h>
|
|
#include <libsec.h>
|
|
|
|
/*
|
|
* destructively encrypt the buffer, which
|
|
* must be at least 8 characters long.
|
|
*/
|
|
int
|
|
encrypt(void *key, void *vbuf, int n)
|
|
{
|
|
uint32_t ekey[32];
|
|
uint8_t *buf;
|
|
int i, r;
|
|
|
|
if(n < 8)
|
|
return 0;
|
|
key_setup(key, ekey);
|
|
buf = vbuf;
|
|
n--;
|
|
r = n % 7;
|
|
n /= 7;
|
|
for(i = 0; i < n; i++){
|
|
block_cipher(ekey, buf, 0);
|
|
buf += 7;
|
|
}
|
|
if(r)
|
|
block_cipher(ekey, buf - 7 + r, 0);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* destructively decrypt the buffer, which
|
|
* must be at least 8 characters long.
|
|
*/
|
|
int
|
|
decrypt(void *key, void *vbuf, int n)
|
|
{
|
|
uint32_t ekey[128];
|
|
uint8_t *buf;
|
|
int i, r;
|
|
|
|
if(n < 8)
|
|
return 0;
|
|
key_setup(key, ekey);
|
|
buf = vbuf;
|
|
n--;
|
|
r = n % 7;
|
|
n /= 7;
|
|
buf += n * 7;
|
|
if(r)
|
|
block_cipher(ekey, buf - 7 + r, 1);
|
|
for(i = 0; i < n; i++){
|
|
buf -= 7;
|
|
block_cipher(ekey, buf, 1);
|
|
}
|
|
return 1;
|
|
}
|