/* DESC.C - Data Encryption Standard routines for RSAREF
*/
#include "global.h"
#include "rsaref.h"
#include "des.h"
/* Initial permutation IP.
*/
unsigned char IP[64] = {
58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
};
/* Final permutation FP = IP^{-1}.
*/
unsigned char FP[64] = {
40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25
};
/* Permuted-choice 1.
*/
unsigned char PC1[] = {
57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4
};
/* Left shifts for the key schedule.
*/
unsigned char LS[16] = {
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
/* Permuted-choice 2.
*/
unsigned char PC2[] = {
14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32
};
/* Bit-selection table E.
*/
unsigned char E[] = {
32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9,
8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17,
16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25,
24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1
};
/* Selection functions (S-boxes). [[These are 0-origin indexed.]]
*/
unsigned char S[8][64] = {
14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13,
15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9,
10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12,
7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14,
2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3,
12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13,
4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12,
13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
};
/* Permutation P.
*/
unsigned char P[32] = {
16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25
};
static void Unpack PROTO_LIST
((unsigned char *, unsigned char *, unsigned int));
static void Pack PROTO_LIST
((unsigned char *, unsigned char *, unsigned int));
/* DES-CBC initialization. Begins a DES-CBC operation, writing a new
context.
*/
void DES_CBCInit (context, key, iv, encrypt)
DES_CBC_CTX *context; /* DES-CBC context */
unsigned char key[8]; /* DES key */
unsigned char iv[8]; /* DES initializing vector */
int encrypt; /* encrypt flag (1 = encrypt, 0 = decrypt) */
{
unsigned char CD[56], keyBit[64], t;
unsigned int i, j;
/* Copy encrypt flag to context.
*/
context->encrypt = encrypt;
/* Unpack initializing vector into context.
*/
Unpack (context->ivBit, iv, 8);
/* Unpack key and generate C and D by permuting the key according to PC1.
*/
Unpack (keyBit, key, 8);
for (i = 0; i < 56; i++)
CD[i] = keyBit[PC1[i]-1];
/* Generate subkeys Ki by rotating C and D according to schedule and
permuting C and D according to PC2.
*/
for (i = 0; i < 16; i++) {
for (j = 0; j < LS[i]; j++) {
t = CD[0];
R_memcpy ((POINTER)CD, (POINTER)&CD[1], 27);
CD[27] = t;
t = CD[28];
R_memcpy ((POINTER)&CD[28], (POINTER)&CD[29], 27);
CD[55] = t;
}
for (j = 0; j < 48; j++)
context->subkeyBit[i][j] = CD[PC2[j]-1];
}
/* Zeroize sensitive information.
*/
R_memset ((POINTER)CD, 0, sizeof (CD));
R_memset ((POINTER)keyBit, 0, sizeof (keyBit));
}
/* DES-CBC block update operation. Continues a DES-CBC encryption
operation, processing eight-byte message blocks, and updating
the context.
*/
int DES_CBCUpdate (context, output, input, len)
DES_CBC_CTX *context; /* DES-CBC context */
unsigned char *output; /* output block */
unsigned char *input; /* input block */
unsigned int len; /* length of input and output blocks */
{
unsigned char inputBit[64], LR[64], newL[32], outputBit[64], sInput[48],
sOutput[32], t;
unsigned int i, j, k;
if (len % 8)
return (RE_LEN);
for (i = 0; i < len/8; i++) {
/* Unpack input block and set LR = IP(input ^ iv) (encrypt) or
LR = IP(input) (decrypt).
*/
Unpack (inputBit, &input[8*i], 8);
if (context->encrypt)
for (j = 0; j < 64; j++)
LR[j] = inputBit[IP[j]-1] ^ context->ivBit[IP[j]-1];
else
for (j = 0; j < 64; j++)
LR[j] = inputBit[IP[j]-1];
/* 16 rounds.
*/
for (j = 0; j < 16; j++) {
/* Save R, which will be the new L.
*/
R_memcpy ((POINTER)newL, &LR[32], 32);
/* Compute sInput = E(R) ^ Kj (encrypt) or sInput = E(R) ^ K{15-j}
(decrypt).
*/
if (context->encrypt)
for (k = 0; k < 48; k++)
sInput[k] = LR[E[k]+31] ^ context->subkeyBit[j][k];
else
for (k = 0; k < 48; k++)
sInput[k] = LR[E[k]+31] ^ context->subkeyBit[15-j][k];
/* Apply eight S boxes. Index into S box k is formed from these
bits of sInput:
6*k 6*k+5 6*k+1 6*k+2 6*k+3 6*k+4
Value of S box k becomes these bits of sOutput:
4*k 4*k+1 4*k+2 4*k+3
*/
for (k = 0; k < 8; k++) {
t = S[k][(sInput[6*k] << 5) | (sInput[6*k + 5] << 4) |
(sInput[6*k + 1] << 3) | (sInput[6*k + 2] << 2) |
(sInput[6*k + 3] << 1) | (sInput[6*k + 4] << 0)];
sOutput[4*k] = (unsigned char)((t >> 3) & 1);
sOutput[4*k + 1] = (unsigned char)((t >> 2) & 1);
sOutput[4*k + 2] = (unsigned char)((t >> 1) & 1);
sOutput[4*k + 3] = (unsigned char)(t & 1);
}
/* Compute new R = L ^ P(sOutput).
*/
for (k = 0; k < 32; k++)
LR[k+32] = LR[k] ^ sOutput[P[k]-1];
/* Restore new L.
*/
R_memcpy ((POINTER)LR, (POINTER)newL, 32);
}
/* Exchange L and R.
*/
R_memcpy ((POINTER)newL, (POINTER)&LR[32], 32);
R_memcpy ((POINTER)&LR[32], (POINTER)LR, 32);
R_memcpy ((POINTER)LR, (POINTER)newL, 32);
/* Set output = FP(LR) (encrypt) or FP(LR) ^ iv (decrypt), and pack
output block.
*/
if (context->encrypt)
for (j = 0; j < 64; j++)
outputBit[j] = LR[FP[j]-1];
else
for (j = 0; j < 64; j++)
outputBit[j] = LR[FP[j]-1] ^ context->ivBit[j];
Pack (&output[8*i], outputBit, 8);
/* Set iv = output (encrypt) or iv = input (decrypt).
*/
if (context->encrypt)
R_memcpy ((POINTER)context->ivBit, (POINTER)outputBit, 64);
else
R_memcpy ((POINTER)context->ivBit, (POINTER)inputBit, 64);
}
/* Zeroize sensitive information.
*/
R_memset ((POINTER)inputBit, 0, sizeof (inputBit));
R_memset ((POINTER)LR, 0, sizeof (LR));
R_memset ((POINTER)newL, 0, sizeof (newL));
R_memset ((POINTER)outputBit, 0, sizeof (outputBit));
R_memset ((POINTER)sInput, 0, sizeof (sInput));
R_memset ((POINTER)sOutput, 0, sizeof (sOutput));
t = 0;
return (0);
}
/* DES-CBC finalization operation. Ends a DES-CBC encryption operation,
zeroizing the context.
*/
void DES_CBCFinal (context)
DES_CBC_CTX *context;
{
R_memset ((POINTER)context, 0, sizeof (*context));
}
static void Unpack (bit, block, blockLen)
unsigned char *bit; /* bit array */
unsigned char *block; /* byte array */
unsigned int blockLen; /* length of byte array */
{
unsigned int i, j;
unsigned char t;
for (i = 0; i < blockLen; i++) {
t = block[i];
for (j = 0; j < 8; j++)
bit[8*i + j] = (unsigned char)((t >> (7-j)) & 1);
}
}
static void Pack (block, bit, blockLen)
unsigned char *block; /* byte array */
unsigned char *bit; /* bit array */
unsigned int blockLen; /* length of byte array */
{
unsigned int i, j;
unsigned char t;
for (i = 0; i < blockLen; i++) {
t = 0;
for (j = 0; j < 8; j++)
t |= bit[8*i +j] << (7-j);
block[i] = t;
}
}
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