pqc/crypto_sign/sphincs-shake256-256f-robust/clean/thash_shake256_robust.c
Thom Wiggers aa4611a4d1 Eliminate the global state
This PR sacrifices passing some extra arguments to get rid of the global
state.

* Haraka needs state in all hash calls, this results in changes to the
  hash functions specified in `hash.h`.  The extra pointers passed would
  not be necessary for SHA256 or SHAKE256.
* SHAKE256 did not have global state, but uniformity in the implementations
  requires us to pass  around the new state context anyway. Otherwise,
  @joostrijneveld's SPHINCS+ generator doesn't really work anymore).

We introduce a new header file called `primitive.h` which defines the
required state type for the generic functions. I did not go into
replacing _all_ occurrences of state variables by the new `hash_state`
macro.
2019-07-16 15:46:27 -04:00

79 lines
2.4 KiB
C

#include <stdint.h>
#include <string.h>
#include "address.h"
#include "params.h"
#include "thash.h"
#include "fips202.h"
/**
* Takes an array of inblocks concatenated arrays of SPX_N bytes.
*/
static void PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash(
unsigned char *out, unsigned char *buf,
const unsigned char *in, unsigned int inblocks,
const unsigned char *pub_seed, uint32_t addr[8]) {
unsigned char *bitmask = buf + SPX_N + SPX_ADDR_BYTES;
unsigned int i;
memcpy(buf, pub_seed, SPX_N);
PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_addr_to_bytes(buf + SPX_N, addr);
shake256(bitmask, inblocks * SPX_N, buf, SPX_N + SPX_ADDR_BYTES);
for (i = 0; i < inblocks * SPX_N; i++) {
buf[SPX_N + SPX_ADDR_BYTES + i] = in[i] ^ bitmask[i];
}
shake256(out, SPX_N, buf, SPX_N + SPX_ADDR_BYTES + inblocks * SPX_N);
}
/* The wrappers below ensure that we use fixed-size buffers on the stack */
void PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash_1(
unsigned char *out, const unsigned char *in,
const unsigned char *pub_seed, uint32_t addr[8],
hash_state *state_seeded) {
unsigned char buf[SPX_N + SPX_ADDR_BYTES + 1 * SPX_N];
PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash(
out, buf, in, 1, pub_seed, addr);
(void)state_seeded;
}
void PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash_2(
unsigned char *out, const unsigned char *in,
const unsigned char *pub_seed, uint32_t addr[8],
hash_state *state_seeded) {
unsigned char buf[SPX_N + SPX_ADDR_BYTES + 2 * SPX_N];
PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash(
out, buf, in, 2, pub_seed, addr);
(void)state_seeded;
}
void PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash_WOTS_LEN(
unsigned char *out, const unsigned char *in,
const unsigned char *pub_seed, uint32_t addr[8],
hash_state *state_seeded) {
unsigned char buf[SPX_N + SPX_ADDR_BYTES + SPX_WOTS_LEN * SPX_N];
PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash(
out, buf, in, SPX_WOTS_LEN, pub_seed, addr);
(void)state_seeded;
}
void PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash_FORS_TREES(
unsigned char *out, const unsigned char *in,
const unsigned char *pub_seed, uint32_t addr[8],
hash_state *state_seeded) {
unsigned char buf[SPX_N + SPX_ADDR_BYTES + SPX_FORS_TREES * SPX_N];
PQCLEAN_SPHINCSSHAKE256256FROBUST_CLEAN_thash(
out, buf, in, SPX_FORS_TREES, pub_seed, addr);
(void)state_seeded;
}