libavutil/des.c File Reference

#include <inttypes.h>
#include "avutil.h"
#include "common.h"
#include "intreadwrite.h"
#include "des.h"

Go to the source code of this file.

Defines

#define T(a, b, c, d, e, f, g, h)   64-a,64-b,64-c,64-d,64-e,64-f,64-g,64-h
#define T(a, b, c, d)   32-a,32-b,32-c,32-d
#define T(a, b, c, d, e, f, g)   64-a,64-b,64-c,64-d,64-e,64-f,64-g
#define T(a, b, c, d, e, f)   56-a,56-b,56-c,56-d,56-e,56-f

Typedefs

typedef struct AVDES AVDES

Functions

static uint64_t shuffle (uint64_t in, const uint8_t *shuffle, int shuffle_len)
static uint64_t shuffle_inv (uint64_t in, const uint8_t *shuffle, int shuffle_len)
static uint32_t f_func (uint32_t r, uint64_t k)
static uint64_t key_shift_left (uint64_t CDn)
 rotate the two halves of the expanded 56 bit key each 1 bit left
static void gen_roundkeys (uint64_t K[16], uint64_t key)
static uint64_t des_encdec (uint64_t in, uint64_t K[16], int decrypt)
int av_des_init (AVDES *d, const uint8_t *key, int key_bits, int decrypt)
 Initializes an AVDES context.
void av_des_crypt (AVDES *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt)
 Encrypts / decrypts using the DES algorithm.

Variables

static const uint8_t IP_shuffle []
static const uint8_t P_shuffle []
static const uint8_t PC1_shuffle []
static const uint8_t PC2_shuffle []
static const uint32_t S_boxes_P_shuffle [8][64]
 This table contains the results of applying both the S-box and P-shuffle.


Define Documentation

#define T ( a,
b,
c,
d,
e,
 )     56-a,56-b,56-c,56-d,56-e,56-f

Definition at line 68 of file des.c.

#define T ( a,
b,
c,
d,
e,
f,
g   )     64-a,64-b,64-c,64-d,64-e,64-f,64-g

Definition at line 68 of file des.c.

#define T ( a,
b,
c,
 )     32-a,32-b,32-c,32-d

Definition at line 68 of file des.c.

#define T ( a,
b,
c,
d,
e,
f,
g,
 )     64-a,64-b,64-c,64-d,64-e,64-f,64-g,64-h

Definition at line 68 of file des.c.


Typedef Documentation

typedef struct AVDES AVDES

Definition at line 27 of file des.c.


Function Documentation

void av_des_crypt ( struct AVDES d,
uint8_t *  dst,
const uint8_t *  src,
int  count,
uint8_t *  iv,
int  decrypt 
)

Encrypts / decrypts using the DES algorithm.

Parameters:
count number of 8 byte blocks
dst destination array, can be equal to src, must be 8-byte aligned
src source array, can be equal to dst, must be 8-byte aligned, may be NULL
iv initialization vector for CBC mode, if NULL then ECB will be used, must be 8-byte aligned
decrypt 0 for encryption, 1 for decryption

Definition at line 299 of file des.c.

Referenced by ff_asfcrypt_dec().

int av_des_init ( struct AVDES d,
const uint8_t *  key,
int  key_bits,
int  decrypt 
)

Initializes an AVDES context.

Parameters:
key_bits must be 64 or 192
decrypt 0 for encryption, 1 for decryption

Definition at line 287 of file des.c.

Referenced by ff_asfcrypt_dec().

static uint64_t des_encdec ( uint64_t  in,
uint64_t  K[16],
int  decrypt 
) [static]

Definition at line 269 of file des.c.

Referenced by av_des_crypt().

static uint32_t f_func ( uint32_t  r,
uint64_t  k 
) [static]

Definition at line 217 of file des.c.

Referenced by des_encdec().

static void gen_roundkeys ( uint64_t  K[16],
uint64_t  key 
) [static]

Definition at line 256 of file des.c.

Referenced by av_des_init().

static uint64_t key_shift_left ( uint64_t  CDn  )  [static]

rotate the two halves of the expanded 56 bit key each 1 bit left

Note: the specification calls this "shift", so I kept it although it is confusing.

Definition at line 248 of file des.c.

Referenced by gen_roundkeys().

static uint64_t shuffle ( uint64_t  in,
const uint8_t *  shuffle,
int  shuffle_len 
) [static]

Definition at line 198 of file des.c.

Referenced by des_encdec(), f_func(), and gen_roundkeys().

static uint64_t shuffle_inv ( uint64_t  in,
const uint8_t *  shuffle,
int  shuffle_len 
) [static]

Definition at line 206 of file des.c.

Referenced by des_encdec().


Variable Documentation

const uint8_t IP_shuffle[] [static]

Initial value:

 {
    T(58, 50, 42, 34, 26, 18, 10, 2),
    T(60, 52, 44, 36, 28, 20, 12, 4),
    T(62, 54, 46, 38, 30, 22, 14, 6),
    T(64, 56, 48, 40, 32, 24, 16, 8),
    T(57, 49, 41, 33, 25, 17,  9, 1),
    T(59, 51, 43, 35, 27, 19, 11, 3),
    T(61, 53, 45, 37, 29, 21, 13, 5),

}

Definition at line 30 of file des.c.

Referenced by des_encdec().

const uint8_t P_shuffle[] [static]

Initial value:

 {
    T(16,  7, 20, 21),
    T(29, 12, 28, 17),
    T( 1, 15, 23, 26),
    T( 5, 18, 31, 10),
    T( 2,  8, 24, 14),
    T(32, 27,  3,  9),
    T(19, 13, 30,  6),

}

Definition at line 43 of file des.c.

Referenced by f_func().

const uint8_t PC1_shuffle[] [static]

Initial value:

 {
    T(57, 49, 41, 33, 25, 17,  9),
    T( 1, 58, 50, 42, 34, 26, 18),
    T(10,  2, 59, 51, 43, 35, 27),
    T(19, 11,  3, 60, 52, 44, 36),
    T(63, 55, 47, 39, 31, 23, 15),
    T( 7, 62, 54, 46, 38, 30, 22),
    T(14,  6, 61, 53, 45, 37, 29),

}

Definition at line 56 of file des.c.

Referenced by gen_roundkeys().

const uint8_t PC2_shuffle[] [static]

Initial value:

 {
    T(14, 17, 11, 24,  1,  5),
    T( 3, 28, 15,  6, 21, 10),
    T(23, 19, 12,  4, 26,  8),
    T(16,  7, 27, 20, 13,  2),
    T(41, 52, 31, 37, 47, 55),
    T(30, 40, 51, 45, 33, 48),
    T(44, 49, 39, 56, 34, 53),

}

Definition at line 69 of file des.c.

Referenced by gen_roundkeys().

const uint32_t S_boxes_P_shuffle[8][64] [static]

This table contains the results of applying both the S-box and P-shuffle.

It can be regenerated by compiling this file with -DCONFIG_SMALL -DTEST -DGENTABLES

Definition at line 114 of file des.c.

Referenced by f_func().


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