158 lines
4.5 KiB
C
158 lines
4.5 KiB
C
/*
|
|
* cifra - embedded cryptography library
|
|
* Written in 2014 by Joseph Birr-Pixton <jpixton@gmail.com>
|
|
*
|
|
* To the extent possible under law, the author(s) have dedicated all
|
|
* copyright and related and neighboring rights to this software to the
|
|
* public domain worldwide. This software is distributed without any
|
|
* warranty.
|
|
*
|
|
* You should have received a copy of the CC0 Public Domain Dedication
|
|
* along with this software. If not, see
|
|
* <http://creativecommons.org/publicdomain/zero/1.0/>.
|
|
*/
|
|
|
|
#include "sha256.h"
|
|
#include <string.h>
|
|
|
|
#include "blockwise.h"
|
|
#include "bitops.h"
|
|
|
|
static const uint32_t K[64] = {
|
|
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
|
|
0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
|
|
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
|
|
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
|
|
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
|
|
0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
|
|
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
|
|
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
|
|
0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
|
|
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
|
|
0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
|
|
0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
|
|
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
|
|
0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
|
|
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
|
|
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
|
|
};
|
|
|
|
# define CH(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
|
|
# define MAJ(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
|
|
# define BSIG0(x) (rotr32((x), 2) ^ rotr32((x), 13) ^ rotr32((x), 22))
|
|
# define BSIG1(x) (rotr32((x), 6) ^ rotr32((x), 11) ^ rotr32((x), 25))
|
|
# define SSIG0(x) (rotr32((x), 7) ^ rotr32((x), 18) ^ ((x) >> 3))
|
|
# define SSIG1(x) (rotr32((x), 17) ^ rotr32((x), 19) ^ ((x) >> 10))
|
|
|
|
void cf_sha256_init(cf_sha256_context *ctx)
|
|
{
|
|
memset(ctx, 0, sizeof *ctx);
|
|
ctx->H[0] = 0x6a09e667;
|
|
ctx->H[1] = 0xbb67ae85;
|
|
ctx->H[2] = 0x3c6ef372;
|
|
ctx->H[3] = 0xa54ff53a;
|
|
ctx->H[4] = 0x510e527f;
|
|
ctx->H[5] = 0x9b05688c;
|
|
ctx->H[6] = 0x1f83d9ab;
|
|
ctx->H[7] = 0x5be0cd19;
|
|
}
|
|
|
|
static void sha256_update_block(void *vctx, const uint8_t *inp)
|
|
{
|
|
cf_sha256_context *ctx = vctx;
|
|
|
|
/* This is a 16-word window into the whole W array. */
|
|
uint32_t W[16];
|
|
|
|
uint32_t a = ctx->H[0],
|
|
b = ctx->H[1],
|
|
c = ctx->H[2],
|
|
d = ctx->H[3],
|
|
e = ctx->H[4],
|
|
f = ctx->H[5],
|
|
g = ctx->H[6],
|
|
h = ctx->H[7],
|
|
Wt;
|
|
|
|
for (size_t t = 0; t < 64; t++)
|
|
{
|
|
/* For W[0..16] we process the input into W.
|
|
* For W[16..64] we compute the next W value:
|
|
*
|
|
* W[t] = SSIG1(W[t - 2]) + W[t - 7] + SSIG0(W[t - 15]) + W[t - 16];
|
|
*
|
|
* But all W indices are reduced mod 16 into our window.
|
|
*/
|
|
if (t < 16)
|
|
{
|
|
W[t] = Wt = read32_be(inp);
|
|
inp += 4;
|
|
} else {
|
|
Wt = SSIG1(W[(t - 2) % 16]) +
|
|
W[(t - 7) % 16] +
|
|
SSIG0(W[(t - 15) % 16]) +
|
|
W[(t - 16) % 16];
|
|
W[t % 16] = Wt;
|
|
}
|
|
|
|
uint32_t T1 = h + BSIG1(e) + CH(e, f, g) + K[t] + Wt;
|
|
uint32_t T2 = BSIG0(a) + MAJ(a, b, c);
|
|
h = g;
|
|
g = f;
|
|
f = e;
|
|
e = d + T1;
|
|
d = c;
|
|
c = b;
|
|
b = a;
|
|
a = T1 + T2;
|
|
}
|
|
|
|
ctx->H[0] += a;
|
|
ctx->H[1] += b;
|
|
ctx->H[2] += c;
|
|
ctx->H[3] += d;
|
|
ctx->H[4] += e;
|
|
ctx->H[5] += f;
|
|
ctx->H[6] += g;
|
|
ctx->H[7] += h;
|
|
|
|
ctx->blocks++;
|
|
}
|
|
|
|
void cf_sha256_update(cf_sha256_context *ctx, const void *data, size_t nbytes)
|
|
{
|
|
cf_blockwise_accumulate(ctx->partial, &ctx->npartial, sizeof ctx->partial,
|
|
data, nbytes,
|
|
sha256_update_block, ctx);
|
|
}
|
|
|
|
void cf_sha256_digest(cf_sha256_context *ctx, uint8_t hash[CF_SHA256_HASHSZ])
|
|
{
|
|
uint64_t digested_bytes = ctx->blocks;
|
|
digested_bytes = digested_bytes * CF_SHA256_BLOCKSZ + ctx->npartial;
|
|
uint64_t digested_bits = digested_bytes * 8;
|
|
|
|
size_t padbytes = CF_SHA256_BLOCKSZ - ((digested_bytes + 8) % CF_SHA256_BLOCKSZ);
|
|
|
|
/* Hash 0x80 00 ... block first. */
|
|
cf_blockwise_acc_pad(ctx->partial, &ctx->npartial, sizeof ctx->partial,
|
|
0x80, 0x00, 0x00, padbytes,
|
|
sha256_update_block, ctx);
|
|
|
|
/* Now hash length. */
|
|
uint8_t buf[8];
|
|
write64_be(digested_bits, buf);
|
|
cf_sha256_update(ctx, buf, 8);
|
|
|
|
write32_be(ctx->H[0], hash + 0);
|
|
write32_be(ctx->H[1], hash + 4);
|
|
write32_be(ctx->H[2], hash + 8);
|
|
write32_be(ctx->H[3], hash + 12);
|
|
write32_be(ctx->H[4], hash + 16);
|
|
write32_be(ctx->H[5], hash + 20);
|
|
write32_be(ctx->H[6], hash + 24);
|
|
write32_be(ctx->H[7], hash + 28);
|
|
|
|
memset(ctx, 0, sizeof *ctx);
|
|
}
|