tomcrypt/rc6.c
2010-06-16 12:37:49 +02:00

254 lines
6.8 KiB
C

#include "mycrypt.h"
#ifdef RC6
const struct _cipher_descriptor rc6_desc =
{
"rc6",
3,
8, 128, 16, 20,
&rc6_setup,
&rc6_ecb_encrypt,
&rc6_ecb_decrypt,
&rc6_test,
&rc6_keysize
};
#ifdef CLEAN_STACK
static int _rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
#else
int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
#endif
{
unsigned long L[64], S[50], A, B, i, j, v, s, t, l;
_ARGCHK(key != NULL);
_ARGCHK(skey != NULL);
/* test parameters */
if (num_rounds != 0 && num_rounds != 20) {
return CRYPT_INVALID_ROUNDS;
}
/* key must be between 64 and 1024 bits */
if (keylen < 8 || keylen > 128) {
return CRYPT_INVALID_KEYSIZE;
}
/* copy the key into the L array */
for (A = i = j = 0; i < (unsigned long)keylen; ) {
A = (A << 8) | ((unsigned long)(key[i++] & 255));
if (!(i & 3)) {
L[j++] = BSWAP(A);
A = 0;
}
}
/* handle odd sized keys */
if (keylen & 3) {
A <<= (8 * (4 - (keylen&3)));
L[j++] = BSWAP(A);
}
/* setup the S array */
t = 44; /* fixed at 20 rounds */
S[0] = 0xB7E15163UL;
for (i = 1; i < t; i++)
S[i] = S[i - 1] + 0x9E3779B9UL;
/* mix buffer */
s = 3 * MAX(t, j);
l = j;
for (A = B = i = j = v = 0; v < s; v++) {
A = S[i] = ROL(S[i] + A + B, 3);
B = L[j] = ROL(L[j] + A + B, (A+B));
i = (i + 1) % t;
j = (j + 1) % l;
}
/* copy to key */
for (i = 0; i < t; i++) {
skey->rc6.K[i] = S[i];
}
return CRYPT_OK;
}
#ifdef CLEAN_STACK
int rc6_setup(const unsigned char *key, int keylen, int num_rounds, symmetric_key *skey)
{
int x;
x = _rc6_setup(key, keylen, num_rounds, skey);
burn_stack(sizeof(unsigned long) * 122);
return x;
}
#endif
#ifdef CLEAN_STACK
static void _rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
#else
void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
#endif
{
unsigned long a,b,c,d,t,u;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(a,&pt[0]);LOAD32L(b,&pt[4]);LOAD32L(c,&pt[8]);LOAD32L(d,&pt[12]);
b += key->rc6.K[0];
d += key->rc6.K[1];
for (r = 0; r < 20; r++) {
t = (b * (b + b + 1)); t = ROL(t, 5);
u = (d * (d + d + 1)); u = ROL(u, 5);
a = ROL(a^t,u) + key->rc6.K[r+r+2];
c = ROL(c^u,t) + key->rc6.K[r+r+3];
t = a; a = b; b = c; c = d; d = t;
}
a += key->rc6.K[42];
c += key->rc6.K[43];
STORE32L(a,&ct[0]);STORE32L(b,&ct[4]);STORE32L(c,&ct[8]);STORE32L(d,&ct[12]);
}
#ifdef CLEAN_STACK
void rc6_ecb_encrypt(const unsigned char *pt, unsigned char *ct, symmetric_key *key)
{
_rc6_ecb_encrypt(pt, ct, key);
burn_stack(sizeof(unsigned long) * 6 + sizeof(int));
}
#endif
#ifdef CLEAN_STACK
static void _rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
#else
void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
#endif
{
unsigned long a,b,c,d,t,u;
int r;
_ARGCHK(key != NULL);
_ARGCHK(pt != NULL);
_ARGCHK(ct != NULL);
LOAD32L(a,&ct[0]);LOAD32L(b,&ct[4]);LOAD32L(c,&ct[8]);LOAD32L(d,&ct[12]);
a -= key->rc6.K[42];
c -= key->rc6.K[43];
for (r = 19; r >= 0; r--) {
t = d; d = c; c = b; b = a; a = t;
t = (b * (b + b + 1)); t = ROL(t, 5);
u = (d * (d + d + 1)); u = ROL(u, 5);
c = ROR(c - key->rc6.K[r+r+3], t) ^ u;
a = ROR(a - key->rc6.K[r+r+2], u) ^ t;
}
b -= key->rc6.K[0];
d -= key->rc6.K[1];
STORE32L(a,&pt[0]);STORE32L(b,&pt[4]);STORE32L(c,&pt[8]);STORE32L(d,&pt[12]);
}
#ifdef CLEAN_STACK
void rc6_ecb_decrypt(const unsigned char *ct, unsigned char *pt, symmetric_key *key)
{
_rc6_ecb_decrypt(ct, pt, key);
burn_stack(sizeof(unsigned long) * 6 + sizeof(int));
}
#endif
int rc6_test(void)
{
static const struct {
int keylen;
unsigned char key[32], pt[16], ct[16];
} tests[] = {
{
16,
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
{ 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
{ 0x52, 0x4e, 0x19, 0x2f, 0x47, 0x15, 0xc6, 0x23,
0x1f, 0x51, 0xf6, 0x36, 0x7e, 0xa4, 0x3f, 0x18 }
},
{
24,
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
{ 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
{ 0x68, 0x83, 0x29, 0xd0, 0x19, 0xe5, 0x05, 0x04,
0x1e, 0x52, 0xe9, 0x2a, 0xf9, 0x52, 0x91, 0xd4 }
},
{
32,
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef,
0x01, 0x12, 0x23, 0x34, 0x45, 0x56, 0x67, 0x78,
0x89, 0x9a, 0xab, 0xbc, 0xcd, 0xde, 0xef, 0xf0,
0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe },
{ 0x02, 0x13, 0x24, 0x35, 0x46, 0x57, 0x68, 0x79,
0x8a, 0x9b, 0xac, 0xbd, 0xce, 0xdf, 0xe0, 0xf1 },
{ 0xc8, 0x24, 0x18, 0x16, 0xf0, 0xd7, 0xe4, 0x89,
0x20, 0xad, 0x16, 0xa1, 0x67, 0x4e, 0x5d, 0x48 }
}
};
unsigned char buf[2][16];
int x, failed, errno;
symmetric_key key;
for (x = failed = 0; x < (int)(sizeof(tests) / sizeof(tests[0])); x++) {
/* setup key */
if ((errno = rc6_setup(tests[x].key, tests[x].keylen, 0, &key)) != CRYPT_OK) {
return errno;
}
/* encrypt and decrypt */
rc6_ecb_encrypt(tests[x].pt, buf[0], &key);
rc6_ecb_decrypt(buf[0], buf[1], &key);
/* compare */
if (memcmp(buf[0], tests[x].ct, 16)) {
#if 0
int y;
printf("\nEncrypt test %d failed\n", x);
for (y = 0; y < 16; y++) printf("%02x ", buf[0][y]);
printf("\n");
#endif
failed = 1;
}
if (memcmp(buf[1], tests[x].pt, 16)) {
#if 0
int y;
printf("\nDecrypt test %d failed\n", x);
for (y = 0; y < 16; y++) printf("%02x ", buf[1][y]);
printf("\n");
#endif
failed = 1;
}
}
if (failed == 1) {
return CRYPT_FAIL_TESTVECTOR;
} else {
return CRYPT_OK;
}
}
int rc6_keysize(int *desired_keysize)
{
_ARGCHK(desired_keysize != NULL);
if (*desired_keysize < 8) {
return CRYPT_INVALID_KEYSIZE;
} else if (*desired_keysize > 128) {
*desired_keysize = 128;
}
return CRYPT_OK;
}
#endif /*RC6*/