void EncryptCBC::encrypt_block(const uint8_t src[16], uint8_t dst[16])
{
if (src != dst) cbc_copy(src, dst);
cbc_xor(l_cbciv, dst);
serpent_encrypt((const uint32_t*)dst, (uint32_t*)dst, l_key);
cbc_copy(dst, l_cbciv);
}
void DecryptCBC::decrypt_block(const uint8_t src[16], uint8_t dst[16])
{
cbc_copy(src, l_cbcivsave); // this is needed if (src == dst)
serpent_decrypt((const uint32_t*)src, (uint32_t*)dst, l_key);
cbc_xor(l_cbciv, dst);
cbc_copy(l_cbcivsave, l_cbciv);
}
static size_t
cbc_encrypt(crypt_mode_t *mode, const void *indata, void *outdata, size_t n, int eof)
{
crypt_cipher_t *cipher = mode->cipher;
size_t blksz = mode->cipher->blockSize;
const uint8_t *src = indata;
uint8_t *dst = outdata;
uint8_t *prev = mode->em_buf;
if (n == 0)
return 0;
if (mode->direction != KCL_DIRECTION_ENCRYPTION) {
(*cipher->keysched)(cipher->ctx, KCL_DIRECTION_ENCRYPTION);
mode->direction = KCL_DIRECTION_ENCRYPTION;
}
while (n >= blksz) {
cbc_xor(prev, src, blksz);
(*cipher->process)(cipher->ctx, prev, dst);
memcpy(prev, dst, blksz);
n -= blksz;
src += blksz;
dst += blksz;
}
if (eof && mode->padding) {
/* process the padding method defined in RFC2630 */
uint8_t pad[CRYPT_MAX_BLOCKSIZE];
uint8_t padbyte = blksz - n;
unsigned int i;
for (i = 0; i < n; i++)
pad[i] = src[i];
for (; i < blksz; i++)
pad[i] = padbyte;
cbc_xor(prev, pad, blksz);
(*cipher->process)(cipher->ctx, prev, dst);
dst += blksz;
}
return dst - (uint8_t *)outdata;
}
