mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-25 11:37:56 +00:00
0278f1c0a3
but gcc's optimizer isn't smart enough to see that. Pre-initializing seems harmless enough. Approved by: re (rwatson)
245 lines
7.8 KiB
C
245 lines
7.8 KiB
C
/* $OpenBSD: cast.c,v 1.2 2000/06/06 06:49:47 deraadt Exp $ */
|
|
/*-
|
|
* CAST-128 in C
|
|
* Written by Steve Reid <sreid@sea-to-sky.net>
|
|
* 100% Public Domain - no warranty
|
|
* Released 1997.10.11
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/types.h>
|
|
#include <opencrypto/cast.h>
|
|
#include <opencrypto/castsb.h>
|
|
|
|
/* Macros to access 8-bit bytes out of a 32-bit word */
|
|
#define U_INT8_Ta(x) ( (u_int8_t) (x>>24) )
|
|
#define U_INT8_Tb(x) ( (u_int8_t) ((x>>16)&255) )
|
|
#define U_INT8_Tc(x) ( (u_int8_t) ((x>>8)&255) )
|
|
#define U_INT8_Td(x) ( (u_int8_t) ((x)&255) )
|
|
|
|
/* Circular left shift */
|
|
#define ROL(x, n) ( ((x)<<(n)) | ((x)>>(32-(n))) )
|
|
|
|
/* CAST-128 uses three different round functions */
|
|
#define F1(l, r, i) \
|
|
t = ROL(key->xkey[i] + r, key->xkey[i+16]); \
|
|
l ^= ((cast_sbox1[U_INT8_Ta(t)] ^ cast_sbox2[U_INT8_Tb(t)]) - \
|
|
cast_sbox3[U_INT8_Tc(t)]) + cast_sbox4[U_INT8_Td(t)];
|
|
#define F2(l, r, i) \
|
|
t = ROL(key->xkey[i] ^ r, key->xkey[i+16]); \
|
|
l ^= ((cast_sbox1[U_INT8_Ta(t)] - cast_sbox2[U_INT8_Tb(t)]) + \
|
|
cast_sbox3[U_INT8_Tc(t)]) ^ cast_sbox4[U_INT8_Td(t)];
|
|
#define F3(l, r, i) \
|
|
t = ROL(key->xkey[i] - r, key->xkey[i+16]); \
|
|
l ^= ((cast_sbox1[U_INT8_Ta(t)] + cast_sbox2[U_INT8_Tb(t)]) ^ \
|
|
cast_sbox3[U_INT8_Tc(t)]) - cast_sbox4[U_INT8_Td(t)];
|
|
|
|
|
|
/***** Encryption Function *****/
|
|
|
|
void cast_encrypt(cast_key* key, u_int8_t* inblock, u_int8_t* outblock)
|
|
{
|
|
u_int32_t t, l, r;
|
|
|
|
/* Get inblock into l,r */
|
|
l = ((u_int32_t)inblock[0] << 24) | ((u_int32_t)inblock[1] << 16) |
|
|
((u_int32_t)inblock[2] << 8) | (u_int32_t)inblock[3];
|
|
r = ((u_int32_t)inblock[4] << 24) | ((u_int32_t)inblock[5] << 16) |
|
|
((u_int32_t)inblock[6] << 8) | (u_int32_t)inblock[7];
|
|
/* Do the work */
|
|
F1(l, r, 0);
|
|
F2(r, l, 1);
|
|
F3(l, r, 2);
|
|
F1(r, l, 3);
|
|
F2(l, r, 4);
|
|
F3(r, l, 5);
|
|
F1(l, r, 6);
|
|
F2(r, l, 7);
|
|
F3(l, r, 8);
|
|
F1(r, l, 9);
|
|
F2(l, r, 10);
|
|
F3(r, l, 11);
|
|
/* Only do full 16 rounds if key length > 80 bits */
|
|
if (key->rounds > 12) {
|
|
F1(l, r, 12);
|
|
F2(r, l, 13);
|
|
F3(l, r, 14);
|
|
F1(r, l, 15);
|
|
}
|
|
/* Put l,r into outblock */
|
|
outblock[0] = U_INT8_Ta(r);
|
|
outblock[1] = U_INT8_Tb(r);
|
|
outblock[2] = U_INT8_Tc(r);
|
|
outblock[3] = U_INT8_Td(r);
|
|
outblock[4] = U_INT8_Ta(l);
|
|
outblock[5] = U_INT8_Tb(l);
|
|
outblock[6] = U_INT8_Tc(l);
|
|
outblock[7] = U_INT8_Td(l);
|
|
/* Wipe clean */
|
|
t = l = r = 0;
|
|
}
|
|
|
|
|
|
/***** Decryption Function *****/
|
|
|
|
void cast_decrypt(cast_key* key, u_int8_t* inblock, u_int8_t* outblock)
|
|
{
|
|
u_int32_t t, l, r;
|
|
|
|
/* Get inblock into l,r */
|
|
r = ((u_int32_t)inblock[0] << 24) | ((u_int32_t)inblock[1] << 16) |
|
|
((u_int32_t)inblock[2] << 8) | (u_int32_t)inblock[3];
|
|
l = ((u_int32_t)inblock[4] << 24) | ((u_int32_t)inblock[5] << 16) |
|
|
((u_int32_t)inblock[6] << 8) | (u_int32_t)inblock[7];
|
|
/* Do the work */
|
|
/* Only do full 16 rounds if key length > 80 bits */
|
|
if (key->rounds > 12) {
|
|
F1(r, l, 15);
|
|
F3(l, r, 14);
|
|
F2(r, l, 13);
|
|
F1(l, r, 12);
|
|
}
|
|
F3(r, l, 11);
|
|
F2(l, r, 10);
|
|
F1(r, l, 9);
|
|
F3(l, r, 8);
|
|
F2(r, l, 7);
|
|
F1(l, r, 6);
|
|
F3(r, l, 5);
|
|
F2(l, r, 4);
|
|
F1(r, l, 3);
|
|
F3(l, r, 2);
|
|
F2(r, l, 1);
|
|
F1(l, r, 0);
|
|
/* Put l,r into outblock */
|
|
outblock[0] = U_INT8_Ta(l);
|
|
outblock[1] = U_INT8_Tb(l);
|
|
outblock[2] = U_INT8_Tc(l);
|
|
outblock[3] = U_INT8_Td(l);
|
|
outblock[4] = U_INT8_Ta(r);
|
|
outblock[5] = U_INT8_Tb(r);
|
|
outblock[6] = U_INT8_Tc(r);
|
|
outblock[7] = U_INT8_Td(r);
|
|
/* Wipe clean */
|
|
t = l = r = 0;
|
|
}
|
|
|
|
|
|
/***** Key Schedual *****/
|
|
|
|
void cast_setkey(cast_key* key, u_int8_t* rawkey, int keybytes)
|
|
{
|
|
u_int32_t t[4] = {0, 0, 0, 0}, z[4] = {0, 0, 0, 0}, x[4];
|
|
int i;
|
|
|
|
/* Set number of rounds to 12 or 16, depending on key length */
|
|
key->rounds = (keybytes <= 10 ? 12 : 16);
|
|
|
|
/* Copy key to workspace x */
|
|
for (i = 0; i < 4; i++) {
|
|
x[i] = 0;
|
|
if ((i*4+0) < keybytes) x[i] = (u_int32_t)rawkey[i*4+0] << 24;
|
|
if ((i*4+1) < keybytes) x[i] |= (u_int32_t)rawkey[i*4+1] << 16;
|
|
if ((i*4+2) < keybytes) x[i] |= (u_int32_t)rawkey[i*4+2] << 8;
|
|
if ((i*4+3) < keybytes) x[i] |= (u_int32_t)rawkey[i*4+3];
|
|
}
|
|
/* Generate 32 subkeys, four at a time */
|
|
for (i = 0; i < 32; i+=4) {
|
|
switch (i & 4) {
|
|
case 0:
|
|
t[0] = z[0] = x[0] ^ cast_sbox5[U_INT8_Tb(x[3])] ^
|
|
cast_sbox6[U_INT8_Td(x[3])] ^ cast_sbox7[U_INT8_Ta(x[3])] ^
|
|
cast_sbox8[U_INT8_Tc(x[3])] ^ cast_sbox7[U_INT8_Ta(x[2])];
|
|
t[1] = z[1] = x[2] ^ cast_sbox5[U_INT8_Ta(z[0])] ^
|
|
cast_sbox6[U_INT8_Tc(z[0])] ^ cast_sbox7[U_INT8_Tb(z[0])] ^
|
|
cast_sbox8[U_INT8_Td(z[0])] ^ cast_sbox8[U_INT8_Tc(x[2])];
|
|
t[2] = z[2] = x[3] ^ cast_sbox5[U_INT8_Td(z[1])] ^
|
|
cast_sbox6[U_INT8_Tc(z[1])] ^ cast_sbox7[U_INT8_Tb(z[1])] ^
|
|
cast_sbox8[U_INT8_Ta(z[1])] ^ cast_sbox5[U_INT8_Tb(x[2])];
|
|
t[3] = z[3] = x[1] ^ cast_sbox5[U_INT8_Tc(z[2])] ^
|
|
cast_sbox6[U_INT8_Tb(z[2])] ^ cast_sbox7[U_INT8_Td(z[2])] ^
|
|
cast_sbox8[U_INT8_Ta(z[2])] ^ cast_sbox6[U_INT8_Td(x[2])];
|
|
break;
|
|
case 4:
|
|
t[0] = x[0] = z[2] ^ cast_sbox5[U_INT8_Tb(z[1])] ^
|
|
cast_sbox6[U_INT8_Td(z[1])] ^ cast_sbox7[U_INT8_Ta(z[1])] ^
|
|
cast_sbox8[U_INT8_Tc(z[1])] ^ cast_sbox7[U_INT8_Ta(z[0])];
|
|
t[1] = x[1] = z[0] ^ cast_sbox5[U_INT8_Ta(x[0])] ^
|
|
cast_sbox6[U_INT8_Tc(x[0])] ^ cast_sbox7[U_INT8_Tb(x[0])] ^
|
|
cast_sbox8[U_INT8_Td(x[0])] ^ cast_sbox8[U_INT8_Tc(z[0])];
|
|
t[2] = x[2] = z[1] ^ cast_sbox5[U_INT8_Td(x[1])] ^
|
|
cast_sbox6[U_INT8_Tc(x[1])] ^ cast_sbox7[U_INT8_Tb(x[1])] ^
|
|
cast_sbox8[U_INT8_Ta(x[1])] ^ cast_sbox5[U_INT8_Tb(z[0])];
|
|
t[3] = x[3] = z[3] ^ cast_sbox5[U_INT8_Tc(x[2])] ^
|
|
cast_sbox6[U_INT8_Tb(x[2])] ^ cast_sbox7[U_INT8_Td(x[2])] ^
|
|
cast_sbox8[U_INT8_Ta(x[2])] ^ cast_sbox6[U_INT8_Td(z[0])];
|
|
break;
|
|
}
|
|
switch (i & 12) {
|
|
case 0:
|
|
case 12:
|
|
key->xkey[i+0] = cast_sbox5[U_INT8_Ta(t[2])] ^ cast_sbox6[U_INT8_Tb(t[2])] ^
|
|
cast_sbox7[U_INT8_Td(t[1])] ^ cast_sbox8[U_INT8_Tc(t[1])];
|
|
key->xkey[i+1] = cast_sbox5[U_INT8_Tc(t[2])] ^ cast_sbox6[U_INT8_Td(t[2])] ^
|
|
cast_sbox7[U_INT8_Tb(t[1])] ^ cast_sbox8[U_INT8_Ta(t[1])];
|
|
key->xkey[i+2] = cast_sbox5[U_INT8_Ta(t[3])] ^ cast_sbox6[U_INT8_Tb(t[3])] ^
|
|
cast_sbox7[U_INT8_Td(t[0])] ^ cast_sbox8[U_INT8_Tc(t[0])];
|
|
key->xkey[i+3] = cast_sbox5[U_INT8_Tc(t[3])] ^ cast_sbox6[U_INT8_Td(t[3])] ^
|
|
cast_sbox7[U_INT8_Tb(t[0])] ^ cast_sbox8[U_INT8_Ta(t[0])];
|
|
break;
|
|
case 4:
|
|
case 8:
|
|
key->xkey[i+0] = cast_sbox5[U_INT8_Td(t[0])] ^ cast_sbox6[U_INT8_Tc(t[0])] ^
|
|
cast_sbox7[U_INT8_Ta(t[3])] ^ cast_sbox8[U_INT8_Tb(t[3])];
|
|
key->xkey[i+1] = cast_sbox5[U_INT8_Tb(t[0])] ^ cast_sbox6[U_INT8_Ta(t[0])] ^
|
|
cast_sbox7[U_INT8_Tc(t[3])] ^ cast_sbox8[U_INT8_Td(t[3])];
|
|
key->xkey[i+2] = cast_sbox5[U_INT8_Td(t[1])] ^ cast_sbox6[U_INT8_Tc(t[1])] ^
|
|
cast_sbox7[U_INT8_Ta(t[2])] ^ cast_sbox8[U_INT8_Tb(t[2])];
|
|
key->xkey[i+3] = cast_sbox5[U_INT8_Tb(t[1])] ^ cast_sbox6[U_INT8_Ta(t[1])] ^
|
|
cast_sbox7[U_INT8_Tc(t[2])] ^ cast_sbox8[U_INT8_Td(t[2])];
|
|
break;
|
|
}
|
|
switch (i & 12) {
|
|
case 0:
|
|
key->xkey[i+0] ^= cast_sbox5[U_INT8_Tc(z[0])];
|
|
key->xkey[i+1] ^= cast_sbox6[U_INT8_Tc(z[1])];
|
|
key->xkey[i+2] ^= cast_sbox7[U_INT8_Tb(z[2])];
|
|
key->xkey[i+3] ^= cast_sbox8[U_INT8_Ta(z[3])];
|
|
break;
|
|
case 4:
|
|
key->xkey[i+0] ^= cast_sbox5[U_INT8_Ta(x[2])];
|
|
key->xkey[i+1] ^= cast_sbox6[U_INT8_Tb(x[3])];
|
|
key->xkey[i+2] ^= cast_sbox7[U_INT8_Td(x[0])];
|
|
key->xkey[i+3] ^= cast_sbox8[U_INT8_Td(x[1])];
|
|
break;
|
|
case 8:
|
|
key->xkey[i+0] ^= cast_sbox5[U_INT8_Tb(z[2])];
|
|
key->xkey[i+1] ^= cast_sbox6[U_INT8_Ta(z[3])];
|
|
key->xkey[i+2] ^= cast_sbox7[U_INT8_Tc(z[0])];
|
|
key->xkey[i+3] ^= cast_sbox8[U_INT8_Tc(z[1])];
|
|
break;
|
|
case 12:
|
|
key->xkey[i+0] ^= cast_sbox5[U_INT8_Td(x[0])];
|
|
key->xkey[i+1] ^= cast_sbox6[U_INT8_Td(x[1])];
|
|
key->xkey[i+2] ^= cast_sbox7[U_INT8_Ta(x[2])];
|
|
key->xkey[i+3] ^= cast_sbox8[U_INT8_Tb(x[3])];
|
|
break;
|
|
}
|
|
if (i >= 16) {
|
|
key->xkey[i+0] &= 31;
|
|
key->xkey[i+1] &= 31;
|
|
key->xkey[i+2] &= 31;
|
|
key->xkey[i+3] &= 31;
|
|
}
|
|
}
|
|
/* Wipe clean */
|
|
for (i = 0; i < 4; i++) {
|
|
t[i] = x[i] = z[i] = 0;
|
|
}
|
|
}
|
|
|
|
/* Made in Canada */
|
|
|