pqc/crypto_kem/mceliece348864f/sse/encrypt.c
Thom Wiggers b3f9d4f8d6
Classic McEliece (#259)
* Add McEliece reference implementations

* Add Vec implementations of McEliece

* Add sse implementations

* Add AVX2 implementations

* Get rid of stuff not supported by Mac ABI

* restrict to two cores

* Ditch .data files

* Remove .hidden from all .S files

* speed up duplicate consistency tests by batching

* make cpuinfo more robust

* Hope to stabilize macos cpuinfo without ccache

* Revert "Hope to stabilize macos cpuinfo without ccache"

This reverts commit 6129c3cabe1abbc8b956bc87e902a698e32bf322.

* Just hardcode what's available at travis

* Fixed-size types in api.h

* namespace all header files in mceliece

* Ditch operations.h

* Get rid of static inline functions

* fixup! Ditch operations.h
2020-02-05 13:09:56 +01:00

100 lines
2.1 KiB
C

/*
This file is for Niederreiter encryption
*/
#include "encrypt.h"
#include "gf.h"
#include "params.h"
#include "randombytes.h"
#include "util.h"
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
/* input: public key pk, error vector e */
/* output: syndrome s */
extern void PQCLEAN_MCELIECE348864F_SSE_syndrome_asm(unsigned char *s, const unsigned char *pk, unsigned char *e);
/* output: e, an error vector of weight t */
static void gen_e(unsigned char *e) {
size_t i, j;
int eq, count;
uint16_t ind_[ SYS_T * 2 ];
uint16_t ind[ SYS_T * 2 ];
uint64_t e_int[ (SYS_N + 63) / 64 ];
uint64_t one = 1;
uint64_t mask;
uint64_t val[ SYS_T ];
while (1) {
randombytes((uint8_t *)ind_, sizeof(ind_));
for (i = 0; i < SYS_T * 2; i++) {
ind_[i] &= GFMASK;
}
count = 0;
for (i = 0; i < SYS_T * 2; i++) {
if (ind_[i] < SYS_N) {
ind[ count++ ] = ind_[i];
}
}
if (count < SYS_T) {
continue;
}
// check for repetition
eq = 0;
for (i = 1; i < SYS_T; i++) {
for (j = 0; j < i; j++) {
if (ind[i] == ind[j]) {
eq = 1;
}
}
}
if (eq == 0) {
break;
}
}
for (j = 0; j < SYS_T; j++) {
val[j] = one << (ind[j] & 63);
}
for (i = 0; i < (SYS_N + 63) / 64; i++) {
e_int[i] = 0;
for (j = 0; j < SYS_T; j++) {
mask = i ^ (ind[j] >> 6);
mask -= 1;
mask >>= 63;
mask = -mask;
e_int[i] |= val[j] & mask;
}
}
for (i = 0; i < (SYS_N + 63) / 64 - 1; i++) {
PQCLEAN_MCELIECE348864F_SSE_store8(e, e_int[i]);
e += 8;
}
for (j = 0; j < (SYS_N % 64); j += 8) {
e[ j / 8 ] = (e_int[i] >> j) & 0xFF;
}
}
void PQCLEAN_MCELIECE348864F_SSE_encrypt(unsigned char *s, unsigned char *e, const unsigned char *pk) {
gen_e(e);
PQCLEAN_MCELIECE348864F_SSE_syndrome_asm(s, pk, e);
}