void tmd_aes_generic_encrypt_xts(aes_block *output, const aes_key *k1, aes_key *k2, aes_block *dataunit,
uint32_t spoint, aes_block *input, uint32_t nb_blocks)
{
aes_block block, tweak;
/* load IV and encrypt it using k2 as the tweak */
block128_copy(&tweak, dataunit);
aes_encrypt_block(&tweak, k2, &tweak);
/* TO OPTIMISE: this is really inefficient way to do that */
while (spoint-- > 0)
tmd_gf_mulx(&tweak);
for ( ; nb_blocks-- > 0; input++, output++, tmd_gf_mulx(&tweak)) {
block128_vxor(&block, input, &tweak);
aes_encrypt_block(&block, k1, &block);
block128_vxor(output, &block, &tweak);
}
}
void aes_decrypt_xts(uint8_t *output, aes_key *k1, aes_key *k2, aes_block *dataunit,
uint32_t spoint, uint8_t *input, uint32_t nb_blocks)
{
aes_block block, tweak;
if (!nb_blocks)
return;
/* load IV and encrypt it using k2 as the tweak */
block128_copy(&tweak, dataunit);
aes_encrypt_block(&tweak, k2, &tweak);
/* TO OPTIMISE: this is really inefficient way to do that */
while (spoint-- > 0)
gf_mulx(&tweak);
for ( ; nb_blocks-- > 0; input += 16, output += 16, gf_mulx(&tweak)) {
block128_vxor(&block, (block128 *) input, &tweak);
aes_decrypt_block(&block, k1, &block);
block128_vxor((block128 *) output, &block, &tweak);
}
}
void tmd_aes_generic_decrypt_cbc(aes_block *output, const aes_key *key, const aes_block *ivini, aes_block *newIV, const aes_block *input, uint32_t nb_blocks)
{
aes_block block, blocko;
aes_block *iv;
iv = newIV;
/* preload IV in block */
block128_copy(iv, ivini);
for ( ; nb_blocks-- > 0; input++, output++) {
block128_copy(&block, (block128 *) input);
tmd_aes_generic_decrypt_block(&blocko, key, &block);
block128_vxor((block128 *) output, &blocko, iv);
block128_copy(iv, &block);
}
}
void aes_encrypt_ctr(uint8_t *output, aes_key *key, aes_block *iv, uint8_t *input, uint32_t len)
{
aes_block block, o;
uint32_t nb_blocks = len / 16;
int i;
/* preload IV in block */
block128_copy(&block, iv);
for ( ; nb_blocks-- > 0; block128_inc_be(&block), output += 16, input += 16) {
aes_encrypt_block(&o, key, &block);
block128_vxor((block128 *) output, &o, (block128 *) input);
}
if ((len % 16) != 0) {
aes_encrypt_block(&o, key, &block);
for (i = 0; i < (len % 16); i++) {
*output = ((uint8_t *) &o)[i] ^ *input;
output += 1;
input += 1;
}
}
}
