/*
* Copyright (C) 2012 Vincent Hanquez <vincent@snarc.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdint.h>
#include <string.h>
#include "cryptonite_bitfn.h"
#include "cryptonite_align.h"
#include "cryptonite_sha3.h"
#define KECCAK_NB_ROUNDS 24
/* rounds constants */
static const uint64_t keccak_rndc[24] =
{
0x0000000000000001ULL, 0x0000000000008082ULL, 0x800000000000808aULL,
0x8000000080008000ULL, 0x000000000000808bULL, 0x0000000080000001ULL,
0x8000000080008081ULL, 0x8000000000008009ULL, 0x000000000000008aULL,
0x0000000000000088ULL, 0x0000000080008009ULL, 0x000000008000000aULL,
0x000000008000808bULL, 0x800000000000008bULL, 0x8000000000008089ULL,
0x8000000000008003ULL, 0x8000000000008002ULL, 0x8000000000000080ULL,
0x000000000000800aULL, 0x800000008000000aULL, 0x8000000080008081ULL,
0x8000000000008080ULL, 0x0000000080000001ULL, 0x8000000080008008ULL,
};
/* triangular numbers constants */
static const int keccak_rotc[24] =
{ 1,3,6,10,15,21,28,36,45,55,2,14,27,41,56,8,25,43,62,18,39,61,20,44 };
static const int keccak_piln[24] =
{ 10,7,11,17,18,3,5,16,8,21,24,4,15,23,19,13,12,2,20,14,22,9,6,1 };
static inline void sha3_do_chunk(uint64_t state[25], uint64_t buf[], int bufsz)
{
int i, j, r;
uint64_t tmp, bc[5];
/* merge buf with state */
for (i = 0; i < bufsz; i++)
state[i] ^= le64_to_cpu(buf[i]);
/* run keccak rounds */
for (r = 0; r < KECCAK_NB_ROUNDS; r++) {
/* compute the parity of each columns */
for (i = 0; i < 5; i++)
bc[i] = state[i] ^ state[i+5] ^ state[i+10] ^ state[i+15] ^ state[i+20];
for (i = 0; i < 5; i++) {
tmp = bc[(i + 4) % 5] ^ rol64(bc[(i + 1) % 5], 1);
for (j = 0; j < 25; j += 5)
state[j + i] ^= tmp;
}
/* rho pi */
tmp = state[1];
for (i = 0; i < 24; i++) {
j = keccak_piln[i];
bc[0] = state[j];
state[j] = rol64(tmp, keccak_rotc[i]);
tmp = bc[0];
}
/* bitwise combine along rows using a = a xor (not b and c) */
for (j = 0; j < 25; j += 5) {
for (i = 0; i < 5; i++)
bc[i] = state[j + i];
#define andn(b,c) (~(b) & (c))
state[j + 0] ^= andn(bc[1], bc[2]);
state[j + 1] ^= andn(bc[2], bc[3]);
state[j + 2] ^= andn(bc[3], bc[4]);
state[j + 3] ^= andn(bc[4], bc[0]);
state[j + 4] ^= andn(bc[0], bc[1]);
#undef andn
}
/* xor the round constant */
state[0] ^= keccak_rndc[r];
}
}
/*
* Initialize a SHA-3 / SHAKE context: hashlen is the security level (and
* half the capacity) in bits
*/
void cryptonite_sha3_init(struct sha3_ctx *ctx, uint32_t hashlen)
{
/* assert(hashlen >= SHA3_BITSIZE_MIN && hashlen <= SHA3_BITSIZE_MAX) */
int bufsz = SHA3_BUF_SIZE(hashlen);
memset(ctx, 0, sizeof(*ctx) + bufsz);
ctx->bufsz = bufsz;
}
/* Update a SHA-3 / SHAKE context */
void cryptonite_sha3_update(struct sha3_ctx *ctx, const uint8_t *data, uint32_t len)
{
uint32_t to_fill;
to_fill = ctx->bufsz - ctx->bufindex;
if (ctx->bufindex == ctx->bufsz) {
sha3_do_chunk(ctx->state, (uint64_t *) ctx->buf, ctx->bufsz / 8);
ctx->bufindex = 0;
}
/* process partial buffer if there's enough data to make a block */
if (ctx->bufindex && len >= to_fill) {
memcpy(ctx->buf + ctx->bufindex, data, to_fill);
sha3_do_chunk(ctx->state, (uint64_t *) ctx->buf, ctx->bufsz / 8);
len -= to_fill;
data += to_fill;
ctx->bufindex = 0;
}
if (need_alignment(data, 8)) {
uint64_t tramp[SHA3_BUF_SIZE_MAX/8];
ASSERT_ALIGNMENT(tramp, 8);
for (; len >= ctx->bufsz; len -= ctx->bufsz, data += ctx->bufsz) {
memcpy(tramp, data, ctx->bufsz);
sha3_do_chunk(ctx->state, tramp, ctx->bufsz / 8);
}
} else {
/* process as much ctx->bufsz-block */
for (; len >= ctx->bufsz; len -= ctx->bufsz, data += ctx->bufsz)
sha3_do_chunk(ctx->state, (uint64_t *) data, ctx->bufsz / 8);
}
/* append data into buf */
if (len) {
memcpy(ctx->buf + ctx->bufindex, data, len);
ctx->bufindex += len;
}
}
void cryptonite_sha3_finalize_with_pad_byte(struct sha3_ctx *ctx, uint8_t pad_byte)
{
/* process full buffer if needed */
if (ctx->bufindex == ctx->bufsz) {
sha3_do_chunk(ctx->state, (uint64_t *) ctx->buf, ctx->bufsz / 8);
ctx->bufindex = 0;
}
/* add the 10*1 padding */
ctx->buf[ctx->bufindex++] = pad_byte;
memset(ctx->buf + ctx->bufindex, 0, ctx->bufsz - ctx->bufindex);
ctx->buf[ctx->bufsz - 1] |= 0x80;
/* process */
sha3_do_chunk(ctx->state, (uint64_t *) ctx->buf, ctx->bufsz / 8);
ctx->bufindex = 0;
}
/*
* Extract some bytes from a finalized SHA-3 / SHAKE context.
* May be called multiple times.
*/
void cryptonite_sha3_output(struct sha3_ctx *ctx, uint8_t *out, uint32_t len)
{
uint64_t w[25];
uint8_t *wptr = (uint8_t *) w;
uint32_t still_avail;
still_avail = ctx->bufsz - ctx->bufindex;
if (ctx->bufindex == ctx->bufsz) {
/* squeeze the sponge again, without any input */
sha3_do_chunk(ctx->state, NULL, 0);
ctx->bufindex = 0;
}
/* use bytes already available if this block is fully consumed */
if (ctx->bufindex && len >= still_avail) {
cpu_to_le64_array(w, ctx->state, 25);
memcpy(out, wptr + ctx->bufindex, still_avail);
sha3_do_chunk(ctx->state, NULL, 0);
len -= still_avail;
out += still_avail;
ctx->bufindex = 0;
}
/* output as much ctx->bufsz-block */
for (; len > ctx->bufsz; len -= ctx->bufsz, out += ctx->bufsz) {
cpu_to_le64_array(w, ctx->state, 25);
memcpy(out, w, ctx->bufsz);
sha3_do_chunk(ctx->state, NULL, 0);
}
/* output from partial buffer */
if (len) {
cpu_to_le64_array(w, ctx->state, 25);
memcpy(out, wptr + ctx->bufindex, len);
ctx->bufindex += len;
}
}
/* Finalize a SHA-3 context and return the digest value */
void cryptonite_sha3_finalize(struct sha3_ctx *ctx, uint32_t hashlen, uint8_t *out)
{
cryptonite_sha3_finalize_with_pad_byte(ctx, 0x06);
cryptonite_sha3_output(ctx, out, hashlen / 8);
}
/* Finalize a SHAKE context. Output is read using cryptonite_sha3_output. */
void cryptonite_sha3_finalize_shake(struct sha3_ctx *ctx)
{
cryptonite_sha3_finalize_with_pad_byte(ctx, 0x1F);
}
void cryptonite_keccak_init(struct sha3_ctx *ctx, uint32_t hashlen)
{
cryptonite_sha3_init(ctx, hashlen);
}
void cryptonite_keccak_update(struct sha3_ctx *ctx, uint8_t *data, uint32_t len)
{
cryptonite_sha3_update(ctx, data, len);
}
void cryptonite_keccak_finalize(struct sha3_ctx *ctx, uint32_t hashlen, uint8_t *out)
{
cryptonite_sha3_finalize_with_pad_byte(ctx, 1);
cryptonite_sha3_output(ctx, out, hashlen / 8);
}