secp256k1/src/hash_impl.h

298 lines
13 KiB
C

/***********************************************************************
* Copyright (c) 2014 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or https://www.opensource.org/licenses/mit-license.php.*
***********************************************************************/
#ifndef SECP256K1_HASH_IMPL_H
#define SECP256K1_HASH_IMPL_H
#include "hash.h"
#include "util.h"
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#define Ch(x,y,z) ((z) ^ ((x) & ((y) ^ (z))))
#define Maj(x,y,z) (((x) & (y)) | ((z) & ((x) | (y))))
#define Sigma0(x) (((x) >> 2 | (x) << 30) ^ ((x) >> 13 | (x) << 19) ^ ((x) >> 22 | (x) << 10))
#define Sigma1(x) (((x) >> 6 | (x) << 26) ^ ((x) >> 11 | (x) << 21) ^ ((x) >> 25 | (x) << 7))
#define sigma0(x) (((x) >> 7 | (x) << 25) ^ ((x) >> 18 | (x) << 14) ^ ((x) >> 3))
#define sigma1(x) (((x) >> 17 | (x) << 15) ^ ((x) >> 19 | (x) << 13) ^ ((x) >> 10))
#define Round(a,b,c,d,e,f,g,h,k,w) do { \
uint32_t t1 = (h) + Sigma1(e) + Ch((e), (f), (g)) + (k) + (w); \
uint32_t t2 = Sigma0(a) + Maj((a), (b), (c)); \
(d) += t1; \
(h) = t1 + t2; \
} while(0)
#if defined(SECP256K1_BIG_ENDIAN)
#define BE32(x) (x)
#elif defined(SECP256K1_LITTLE_ENDIAN)
#define BE32(p) ((((p) & 0xFF) << 24) | (((p) & 0xFF00) << 8) | (((p) & 0xFF0000) >> 8) | (((p) & 0xFF000000) >> 24))
#endif
static void secp256k1_sha256_initialize(secp256k1_sha256 *hash) {
hash->s[0] = 0x6a09e667ul;
hash->s[1] = 0xbb67ae85ul;
hash->s[2] = 0x3c6ef372ul;
hash->s[3] = 0xa54ff53aul;
hash->s[4] = 0x510e527ful;
hash->s[5] = 0x9b05688cul;
hash->s[6] = 0x1f83d9abul;
hash->s[7] = 0x5be0cd19ul;
hash->bytes = 0;
}
/** Perform one SHA-256 transformation, processing 16 big endian 32-bit words. */
static void secp256k1_sha256_transform(uint32_t* s, const uint32_t* chunk) {
uint32_t a = s[0], b = s[1], c = s[2], d = s[3], e = s[4], f = s[5], g = s[6], h = s[7];
uint32_t w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15;
Round(a, b, c, d, e, f, g, h, 0x428a2f98, w0 = BE32(chunk[0]));
Round(h, a, b, c, d, e, f, g, 0x71374491, w1 = BE32(chunk[1]));
Round(g, h, a, b, c, d, e, f, 0xb5c0fbcf, w2 = BE32(chunk[2]));
Round(f, g, h, a, b, c, d, e, 0xe9b5dba5, w3 = BE32(chunk[3]));
Round(e, f, g, h, a, b, c, d, 0x3956c25b, w4 = BE32(chunk[4]));
Round(d, e, f, g, h, a, b, c, 0x59f111f1, w5 = BE32(chunk[5]));
Round(c, d, e, f, g, h, a, b, 0x923f82a4, w6 = BE32(chunk[6]));
Round(b, c, d, e, f, g, h, a, 0xab1c5ed5, w7 = BE32(chunk[7]));
Round(a, b, c, d, e, f, g, h, 0xd807aa98, w8 = BE32(chunk[8]));
Round(h, a, b, c, d, e, f, g, 0x12835b01, w9 = BE32(chunk[9]));
Round(g, h, a, b, c, d, e, f, 0x243185be, w10 = BE32(chunk[10]));
Round(f, g, h, a, b, c, d, e, 0x550c7dc3, w11 = BE32(chunk[11]));
Round(e, f, g, h, a, b, c, d, 0x72be5d74, w12 = BE32(chunk[12]));
Round(d, e, f, g, h, a, b, c, 0x80deb1fe, w13 = BE32(chunk[13]));
Round(c, d, e, f, g, h, a, b, 0x9bdc06a7, w14 = BE32(chunk[14]));
Round(b, c, d, e, f, g, h, a, 0xc19bf174, w15 = BE32(chunk[15]));
Round(a, b, c, d, e, f, g, h, 0xe49b69c1, w0 += sigma1(w14) + w9 + sigma0(w1));
Round(h, a, b, c, d, e, f, g, 0xefbe4786, w1 += sigma1(w15) + w10 + sigma0(w2));
Round(g, h, a, b, c, d, e, f, 0x0fc19dc6, w2 += sigma1(w0) + w11 + sigma0(w3));
Round(f, g, h, a, b, c, d, e, 0x240ca1cc, w3 += sigma1(w1) + w12 + sigma0(w4));
Round(e, f, g, h, a, b, c, d, 0x2de92c6f, w4 += sigma1(w2) + w13 + sigma0(w5));
Round(d, e, f, g, h, a, b, c, 0x4a7484aa, w5 += sigma1(w3) + w14 + sigma0(w6));
Round(c, d, e, f, g, h, a, b, 0x5cb0a9dc, w6 += sigma1(w4) + w15 + sigma0(w7));
Round(b, c, d, e, f, g, h, a, 0x76f988da, w7 += sigma1(w5) + w0 + sigma0(w8));
Round(a, b, c, d, e, f, g, h, 0x983e5152, w8 += sigma1(w6) + w1 + sigma0(w9));
Round(h, a, b, c, d, e, f, g, 0xa831c66d, w9 += sigma1(w7) + w2 + sigma0(w10));
Round(g, h, a, b, c, d, e, f, 0xb00327c8, w10 += sigma1(w8) + w3 + sigma0(w11));
Round(f, g, h, a, b, c, d, e, 0xbf597fc7, w11 += sigma1(w9) + w4 + sigma0(w12));
Round(e, f, g, h, a, b, c, d, 0xc6e00bf3, w12 += sigma1(w10) + w5 + sigma0(w13));
Round(d, e, f, g, h, a, b, c, 0xd5a79147, w13 += sigma1(w11) + w6 + sigma0(w14));
Round(c, d, e, f, g, h, a, b, 0x06ca6351, w14 += sigma1(w12) + w7 + sigma0(w15));
Round(b, c, d, e, f, g, h, a, 0x14292967, w15 += sigma1(w13) + w8 + sigma0(w0));
Round(a, b, c, d, e, f, g, h, 0x27b70a85, w0 += sigma1(w14) + w9 + sigma0(w1));
Round(h, a, b, c, d, e, f, g, 0x2e1b2138, w1 += sigma1(w15) + w10 + sigma0(w2));
Round(g, h, a, b, c, d, e, f, 0x4d2c6dfc, w2 += sigma1(w0) + w11 + sigma0(w3));
Round(f, g, h, a, b, c, d, e, 0x53380d13, w3 += sigma1(w1) + w12 + sigma0(w4));
Round(e, f, g, h, a, b, c, d, 0x650a7354, w4 += sigma1(w2) + w13 + sigma0(w5));
Round(d, e, f, g, h, a, b, c, 0x766a0abb, w5 += sigma1(w3) + w14 + sigma0(w6));
Round(c, d, e, f, g, h, a, b, 0x81c2c92e, w6 += sigma1(w4) + w15 + sigma0(w7));
Round(b, c, d, e, f, g, h, a, 0x92722c85, w7 += sigma1(w5) + w0 + sigma0(w8));
Round(a, b, c, d, e, f, g, h, 0xa2bfe8a1, w8 += sigma1(w6) + w1 + sigma0(w9));
Round(h, a, b, c, d, e, f, g, 0xa81a664b, w9 += sigma1(w7) + w2 + sigma0(w10));
Round(g, h, a, b, c, d, e, f, 0xc24b8b70, w10 += sigma1(w8) + w3 + sigma0(w11));
Round(f, g, h, a, b, c, d, e, 0xc76c51a3, w11 += sigma1(w9) + w4 + sigma0(w12));
Round(e, f, g, h, a, b, c, d, 0xd192e819, w12 += sigma1(w10) + w5 + sigma0(w13));
Round(d, e, f, g, h, a, b, c, 0xd6990624, w13 += sigma1(w11) + w6 + sigma0(w14));
Round(c, d, e, f, g, h, a, b, 0xf40e3585, w14 += sigma1(w12) + w7 + sigma0(w15));
Round(b, c, d, e, f, g, h, a, 0x106aa070, w15 += sigma1(w13) + w8 + sigma0(w0));
Round(a, b, c, d, e, f, g, h, 0x19a4c116, w0 += sigma1(w14) + w9 + sigma0(w1));
Round(h, a, b, c, d, e, f, g, 0x1e376c08, w1 += sigma1(w15) + w10 + sigma0(w2));
Round(g, h, a, b, c, d, e, f, 0x2748774c, w2 += sigma1(w0) + w11 + sigma0(w3));
Round(f, g, h, a, b, c, d, e, 0x34b0bcb5, w3 += sigma1(w1) + w12 + sigma0(w4));
Round(e, f, g, h, a, b, c, d, 0x391c0cb3, w4 += sigma1(w2) + w13 + sigma0(w5));
Round(d, e, f, g, h, a, b, c, 0x4ed8aa4a, w5 += sigma1(w3) + w14 + sigma0(w6));
Round(c, d, e, f, g, h, a, b, 0x5b9cca4f, w6 += sigma1(w4) + w15 + sigma0(w7));
Round(b, c, d, e, f, g, h, a, 0x682e6ff3, w7 += sigma1(w5) + w0 + sigma0(w8));
Round(a, b, c, d, e, f, g, h, 0x748f82ee, w8 += sigma1(w6) + w1 + sigma0(w9));
Round(h, a, b, c, d, e, f, g, 0x78a5636f, w9 += sigma1(w7) + w2 + sigma0(w10));
Round(g, h, a, b, c, d, e, f, 0x84c87814, w10 += sigma1(w8) + w3 + sigma0(w11));
Round(f, g, h, a, b, c, d, e, 0x8cc70208, w11 += sigma1(w9) + w4 + sigma0(w12));
Round(e, f, g, h, a, b, c, d, 0x90befffa, w12 += sigma1(w10) + w5 + sigma0(w13));
Round(d, e, f, g, h, a, b, c, 0xa4506ceb, w13 += sigma1(w11) + w6 + sigma0(w14));
Round(c, d, e, f, g, h, a, b, 0xbef9a3f7, w14 + sigma1(w12) + w7 + sigma0(w15));
Round(b, c, d, e, f, g, h, a, 0xc67178f2, w15 + sigma1(w13) + w8 + sigma0(w0));
s[0] += a;
s[1] += b;
s[2] += c;
s[3] += d;
s[4] += e;
s[5] += f;
s[6] += g;
s[7] += h;
}
static void secp256k1_sha256_write(secp256k1_sha256 *hash, const unsigned char *data, size_t len) {
size_t bufsize = hash->bytes & 0x3F;
hash->bytes += len;
VERIFY_CHECK(hash->bytes >= len);
while (len >= 64 - bufsize) {
/* Fill the buffer, and process it. */
size_t chunk_len = 64 - bufsize;
memcpy(((unsigned char*)hash->buf) + bufsize, data, chunk_len);
data += chunk_len;
len -= chunk_len;
secp256k1_sha256_transform(hash->s, hash->buf);
bufsize = 0;
}
if (len) {
/* Fill the buffer with what remains. */
memcpy(((unsigned char*)hash->buf) + bufsize, data, len);
}
}
static void secp256k1_sha256_finalize(secp256k1_sha256 *hash, unsigned char *out32) {
static const unsigned char pad[64] = {0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
uint32_t sizedesc[2];
uint32_t out[8];
int i = 0;
sizedesc[0] = BE32(hash->bytes >> 29);
sizedesc[1] = BE32(hash->bytes << 3);
secp256k1_sha256_write(hash, pad, 1 + ((119 - (hash->bytes % 64)) % 64));
secp256k1_sha256_write(hash, (const unsigned char*)sizedesc, 8);
for (i = 0; i < 8; i++) {
out[i] = BE32(hash->s[i]);
hash->s[i] = 0;
}
memcpy(out32, (const unsigned char*)out, 32);
}
/* Initializes a sha256 struct and writes the 64 byte string
* SHA256(tag)||SHA256(tag) into it. */
static void secp256k1_sha256_initialize_tagged(secp256k1_sha256 *hash, const unsigned char *tag, size_t taglen) {
unsigned char buf[32];
secp256k1_sha256_initialize(hash);
secp256k1_sha256_write(hash, tag, taglen);
secp256k1_sha256_finalize(hash, buf);
secp256k1_sha256_initialize(hash);
secp256k1_sha256_write(hash, buf, 32);
secp256k1_sha256_write(hash, buf, 32);
}
static void secp256k1_hmac_sha256_initialize(secp256k1_hmac_sha256 *hash, const unsigned char *key, size_t keylen) {
size_t n;
unsigned char rkey[64];
if (keylen <= sizeof(rkey)) {
memcpy(rkey, key, keylen);
memset(rkey + keylen, 0, sizeof(rkey) - keylen);
} else {
secp256k1_sha256 sha256;
secp256k1_sha256_initialize(&sha256);
secp256k1_sha256_write(&sha256, key, keylen);
secp256k1_sha256_finalize(&sha256, rkey);
memset(rkey + 32, 0, 32);
}
secp256k1_sha256_initialize(&hash->outer);
for (n = 0; n < sizeof(rkey); n++) {
rkey[n] ^= 0x5c;
}
secp256k1_sha256_write(&hash->outer, rkey, sizeof(rkey));
secp256k1_sha256_initialize(&hash->inner);
for (n = 0; n < sizeof(rkey); n++) {
rkey[n] ^= 0x5c ^ 0x36;
}
secp256k1_sha256_write(&hash->inner, rkey, sizeof(rkey));
memset(rkey, 0, sizeof(rkey));
}
static void secp256k1_hmac_sha256_write(secp256k1_hmac_sha256 *hash, const unsigned char *data, size_t size) {
secp256k1_sha256_write(&hash->inner, data, size);
}
static void secp256k1_hmac_sha256_finalize(secp256k1_hmac_sha256 *hash, unsigned char *out32) {
unsigned char temp[32];
secp256k1_sha256_finalize(&hash->inner, temp);
secp256k1_sha256_write(&hash->outer, temp, 32);
memset(temp, 0, 32);
secp256k1_sha256_finalize(&hash->outer, out32);
}
static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha256 *rng, const unsigned char *key, size_t keylen) {
secp256k1_hmac_sha256 hmac;
static const unsigned char zero[1] = {0x00};
static const unsigned char one[1] = {0x01};
memset(rng->v, 0x01, 32); /* RFC6979 3.2.b. */
memset(rng->k, 0x00, 32); /* RFC6979 3.2.c. */
/* RFC6979 3.2.d. */
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, zero, 1);
secp256k1_hmac_sha256_write(&hmac, key, keylen);
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_finalize(&hmac, rng->v);
/* RFC6979 3.2.f. */
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, one, 1);
secp256k1_hmac_sha256_write(&hmac, key, keylen);
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_finalize(&hmac, rng->v);
rng->retry = 0;
}
static void secp256k1_rfc6979_hmac_sha256_generate(secp256k1_rfc6979_hmac_sha256 *rng, unsigned char *out, size_t outlen) {
/* RFC6979 3.2.h. */
static const unsigned char zero[1] = {0x00};
if (rng->retry) {
secp256k1_hmac_sha256 hmac;
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, zero, 1);
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_finalize(&hmac, rng->v);
}
while (outlen > 0) {
secp256k1_hmac_sha256 hmac;
int now = outlen;
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_finalize(&hmac, rng->v);
if (now > 32) {
now = 32;
}
memcpy(out, rng->v, now);
out += now;
outlen -= now;
}
rng->retry = 1;
}
static void secp256k1_rfc6979_hmac_sha256_finalize(secp256k1_rfc6979_hmac_sha256 *rng) {
memset(rng->k, 0, 32);
memset(rng->v, 0, 32);
rng->retry = 0;
}
#undef BE32
#undef Round
#undef sigma1
#undef sigma0
#undef Sigma1
#undef Sigma0
#undef Maj
#undef Ch
#endif /* SECP256K1_HASH_IMPL_H */