/* hmac */
static void
scrypt_hmac_init(scrypt_hmac_state *st, const uint8_t *key, size_t keylen) {
uint8_t pad[SCRYPT_HASH_BLOCK_SIZE] = {0};
size_t i;
scrypt_hash_init(&st->inner);
scrypt_hash_init(&st->outer);
if (keylen <= SCRYPT_HASH_BLOCK_SIZE) {
/* use the key directly if it's <= blocksize bytes */
memcpy(pad, key, keylen);
} else {
/* if it's > blocksize bytes, hash it */
scrypt_hash(pad, key, keylen);
}
/* inner = (key ^ 0x36) */
/* h(inner || ...) */
for (i = 0; i < SCRYPT_HASH_BLOCK_SIZE; i++)
pad[i] ^= 0x36;
scrypt_hash_update(&st->inner, pad, SCRYPT_HASH_BLOCK_SIZE);
/* outer = (key ^ 0x5c) */
/* h(outer || ...) */
for (i = 0; i < SCRYPT_HASH_BLOCK_SIZE; i++)
pad[i] ^= (0x5c ^ 0x36);
scrypt_hash_update(&st->outer, pad, SCRYPT_HASH_BLOCK_SIZE);
}
static PyObject *scrypt_getpowhash(PyObject *self, PyObject *args)
{
char *output;
int timestamp;
PyObject *value;
PyStringObject *input;
if (!PyArg_ParseTuple(args, "Si", &input, ×tamp))
return NULL;
Py_INCREF(input);
output = (char *)PyMem_Malloc(32);
memset(output, 0, 32);
scrypt_hash((char *)PyString_AsString((PyObject*) input), 80, (uint32_t *)output, GetNfactor(timestamp));
Py_DECREF(input);
value = Py_BuildValue("s#", output, 32);
PyMem_Free(output);
return value;
}