/*--------------------------------------------------------------------------------
DES.C: DES Algorithm Program from the Book Appliced Cryptography, Bruce Schneier
--------------------------------------------------------------------------------*/
typedef struct {
unsigned long ek[32];
unsigned long dk[32];
} des_ctx;
extern void deskey(unsigned char *, short);
/* hexkey[8] MODE
* Sets the internal key register according to the hexadecimal
* key contained in the 8 bytes of hexkey, according to the DES,
* for encryption or decryption according to MODE.
*/
extern void usekey(unsigned long *);
/* cookedkey[32]
* Loads the internal key register with the data in cookedkey.
*/
extern void cpkey(unsigned long *);
/* cookedkey[32]
* Copies the contents of the internal key register into the storage
* located at &cookedkey[0].
*/
extern void des(unsigned char *, unsigned char *);
/* from[8] to[8]
* Encrypts/Decrypts (according to the key currently loaded in the
* internal key register) one block of eight bytes at address 'from'
* into the block at address 'to'. They can be the same.
*/
static void scrunch(unsigned char *, unsigned long *);
static void unscrun(unsigned long *, unsigned char *);
static void desfunc(unsigned long *, unsigned long *);
static void cookey(unsigned long *);
void deskey(unsigned char *key, short edf) {
/* Thanks to James Gillogly & Phil Karn! */
register int i, j, l, m, n;
unsigned char pc1m[56], pcr[56];
unsigned long kn[32];