+++ /dev/null
-/* sha256.h
- *
- * The sha256 hash function.
- */
-
-/* nettle, low-level cryptographics library
- *
- * Copyright (C) 2001 Niels Möller
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * The nettle library is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- * License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with the nettle library; see the file COPYING.LIB. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/* Modelled after the sha1.c code by Peter Gutmann. */
-
-#include "mhash_sha256.h"
-#include <stdlib.h>
-#include <string.h>
-
-
-#ifndef EXTRACT_UCHAR
-#define EXTRACT_UCHAR(p) (*(unsigned char *)(p))
-#endif
-
-#define STRING2INT(s) ((((((EXTRACT_UCHAR(s) << 8) \
- | EXTRACT_UCHAR(s+1)) << 8) \
- | EXTRACT_UCHAR(s+2)) << 8) \
- | EXTRACT_UCHAR(s+3))
-
-/* This has been modified in order to fit in mhash.
- * --nmav.
- */
-
-/* A block, treated as a sequence of 32-bit words. */
-#define SHA256_DATA_LENGTH 16
-
-#define ROTR(n,x) ((x)>>(n) | ((x)<<(32-(n))))
-#define SHR(n,x) ((x)>>(n))
-
-/* The SHA256 functions. The Choice function is the same as the SHA1
- function f1, and the majority function is the same as the SHA1 f3
- function. They can be optimized to save one boolean operation each
- - thanks to Rich Schroeppel, rcs@cs.arizona.edu for discovering
- this */
-
-/* #define Choice(x,y,z) ( ( (x) & (y) ) | ( ~(x) & (z) ) ) */
-#define Choice(x,y,z) ( (z) ^ ( (x) & ( (y) ^ (z) ) ) )
-/* #define Majority(x,y,z) ( ((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)) ) */
-#define Majority(x,y,z) ( ((x) & (y)) ^ ((z) & ((x) ^ (y))) )
-
-#define S0(x) (ROTR(2,(x)) ^ ROTR(13,(x)) ^ ROTR(22,(x)))
-#define S1(x) (ROTR(6,(x)) ^ ROTR(11,(x)) ^ ROTR(25,(x)))
-
-#define s0(x) (ROTR(7,(x)) ^ ROTR(18,(x)) ^ SHR(3,(x)))
-#define s1(x) (ROTR(17,(x)) ^ ROTR(19,(x)) ^ SHR(10,(x)))
-
-/* Generated by the shadata program. */
-static const word32 K[64] = {
- 0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
- 0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
- 0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,
- 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,
- 0xe49b69c1UL, 0xefbe4786UL, 0xfc19dc6UL, 0x240ca1ccUL,
- 0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,
- 0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,
- 0xc6e00bf3UL, 0xd5a79147UL, 0x6ca6351UL, 0x14292967UL,
- 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,
- 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
- 0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,
- 0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,
- 0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,
- 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,
- 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
- 0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL,
-};
-
-/* The initial expanding function. The hash function is defined over an
- 64-word expanded input array W, where the first 16 are copies of the input
- data, and the remaining 64 are defined by
-
- W[ t ] = s1(W[t-2] + W[t-7] + s0(W[i-15] + W[i-16]
-
- This implementation generates these values on the fly in a circular
- buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
- optimization.
-*/
-
-#define EXPAND(W,i) \
-( W[(i) & 15 ] += (s1(W[((i)-2) & 15]) + W[((i)-7) & 15] + s0(W[((i)-15) & 15])) )
-
-/* The prototype SHA sub-round. The fundamental sub-round is:
-
- T1 = h + S1(e) + Choice(e,f,g) + K[t] + W[t]
- T2 = S0(a) + Majority(a,b,c)
- a' = T1+T2
- b' = a
- c' = b
- d' = c
- e' = d + T1
- f' = e
- g' = f
- h' = g
-
- but this is implemented by unrolling the loop 8 times and renaming
- the variables
- ( h, a, b, c, d, e, f, g ) = ( a, b, c, d, e, f, g, h ) each
- iteration. This code is then replicated 8, using the next 8 values
- from the W[] array each time */
-
-/* FIXME: We can probably reorder this to optimize away at least one
- * of T1 and T2. It's crucial that DATA is only used once, as that
- * argument will have side effects. */
-#define ROUND(a,b,c,d,e,f,g,h,k,data) do { \
- word32 T1 = h + S1(e) + Choice(e,f,g) + k + data; \
- word32 T2 = S0(a) + Majority(a,b,c); \
- d += T1; \
- h = T1 + T2; \
-} while (0)
-
-/* Initialize the SHA values */
-
-void sha256_init(struct sha256_ctx *ctx)
-{
- /* Initial values, also generated by the shadata program. */
- static const word32 H0[_SHA256_DIGEST_LENGTH] = {
- 0x6a09e667UL, 0xbb67ae85UL, 0x3c6ef372UL, 0xa54ff53aUL,
- 0x510e527fUL, 0x9b05688cUL, 0x1f83d9abUL, 0x5be0cd19UL,
- };
-
- memcpy(ctx->state, H0, sizeof(H0));
-
- /* Initialize bit count */
- ctx->count_low = ctx->count_high = 0;
-
- /* Initialize buffer */
- ctx->index = 0;
-}
-
-/* Perform the SHA transformation. Note that this code, like MD5, seems to
- break some optimizing compilers due to the complexity of the expressions
- and the size of the basic block. It may be necessary to split it into
- sections, e.g. based on the four subrounds
-
- Note that this function destroys the data area */
-
-static void sha256_transform(word32 * state, word32 * data)
-{
- word32 A, B, C, D, E, F, G, H; /* Local vars */
- unsigned i;
- const word32 *k;
- word32 *d;
-
- /* Set up first buffer and local data buffer */
- A = state[0];
- B = state[1];
- C = state[2];
- D = state[3];
- E = state[4];
- F = state[5];
- G = state[6];
- H = state[7];
-
- /* Heavy mangling */
- /* First 16 subrounds that act on the original data */
-
- for (i = 0, k = K, d = data; i < 16; i += 8, k += 8, d += 8) {
- ROUND(A, B, C, D, E, F, G, H, k[0], d[0]);
- ROUND(H, A, B, C, D, E, F, G, k[1], d[1]);
- ROUND(G, H, A, B, C, D, E, F, k[2], d[2]);
- ROUND(F, G, H, A, B, C, D, E, k[3], d[3]);
- ROUND(E, F, G, H, A, B, C, D, k[4], d[4]);
- ROUND(D, E, F, G, H, A, B, C, k[5], d[5]);
- ROUND(C, D, E, F, G, H, A, B, k[6], d[6]);
- ROUND(B, C, D, E, F, G, H, A, k[7], d[7]);
- }
-
- for (; i < 64; i += 16, k += 16) {
- ROUND(A, B, C, D, E, F, G, H, k[0], EXPAND(data, 0));
- ROUND(H, A, B, C, D, E, F, G, k[1], EXPAND(data, 1));
- ROUND(G, H, A, B, C, D, E, F, k[2], EXPAND(data, 2));
- ROUND(F, G, H, A, B, C, D, E, k[3], EXPAND(data, 3));
- ROUND(E, F, G, H, A, B, C, D, k[4], EXPAND(data, 4));
- ROUND(D, E, F, G, H, A, B, C, k[5], EXPAND(data, 5));
- ROUND(C, D, E, F, G, H, A, B, k[6], EXPAND(data, 6));
- ROUND(B, C, D, E, F, G, H, A, k[7], EXPAND(data, 7));
- ROUND(A, B, C, D, E, F, G, H, k[8], EXPAND(data, 8));
- ROUND(H, A, B, C, D, E, F, G, k[9], EXPAND(data, 9));
- ROUND(G, H, A, B, C, D, E, F, k[10], EXPAND(data, 10));
- ROUND(F, G, H, A, B, C, D, E, k[11], EXPAND(data, 11));
- ROUND(E, F, G, H, A, B, C, D, k[12], EXPAND(data, 12));
- ROUND(D, E, F, G, H, A, B, C, k[13], EXPAND(data, 13));
- ROUND(C, D, E, F, G, H, A, B, k[14], EXPAND(data, 14));
- ROUND(B, C, D, E, F, G, H, A, k[15], EXPAND(data, 15));
- }
-
- /* Update state */
- state[0] += A;
- state[1] += B;
- state[2] += C;
- state[3] += D;
- state[4] += E;
- state[5] += F;
- state[6] += G;
- state[7] += H;
-}
-
-static void sha256_block(struct sha256_ctx *ctx, const byte * block)
-{
- word32 data[SHA256_DATA_LENGTH];
- int i;
-
- /* Update block count */
- if (!++ctx->count_low)
- ++ctx->count_high;
-
- /* Endian independent conversion */
- for (i = 0; i < SHA256_DATA_LENGTH; i++, block += 4)
- data[i] = STRING2INT(block);
-
- sha256_transform(ctx->state, data);
-}
-
-void
-sha256_update(struct sha256_ctx *ctx, const byte * buffer, unsigned length)
-{
- if (ctx->index) { /* Try to fill partial block */
- unsigned left = SHA256_DATA_SIZE - ctx->index;
- if (length < left) {
- memcpy(ctx->block + ctx->index, buffer, length);
- ctx->index += length;
- return; /* Finished */
- } else {
- memcpy(ctx->block + ctx->index, buffer, left);
- sha256_block(ctx, ctx->block);
- buffer += left;
- length -= left;
- }
- }
- while (length >= SHA256_DATA_SIZE) {
- sha256_block(ctx, buffer);
- buffer += SHA256_DATA_SIZE;
- length -= SHA256_DATA_SIZE;
- }
- /* Buffer leftovers */
- /* NOTE: The corresponding sha1 code checks for the special case length == 0.
- * That seems supoptimal, as I suspect it increases the number of branches. */
-
- memcpy(ctx->block, buffer, length);
- ctx->index = length;
-}
-
-/* Final wrapup - pad to SHA1_DATA_SIZE-byte boundary with the bit pattern
- 1 0* (64-bit count of bits processed, MSB-first) */
-
-void sha256_final(struct sha256_ctx *ctx)
-{
- word32 data[SHA256_DATA_LENGTH];
- int i;
- int words;
-
- i = ctx->index;
-
- /* Set the first char of padding to 0x80. This is safe since there is
- always at least one byte free */
-
-/* assert(i < SHA256_DATA_SIZE);
- */
- ctx->block[i++] = 0x80;
-
- /* Fill rest of word */
- for (; i & 3; i++)
- ctx->block[i] = 0;
-
- /* i is now a multiple of the word size 4 */
- words = i >> 2;
- for (i = 0; i < words; i++)
- data[i] = STRING2INT(ctx->block + 4 * i);
-
- if (words > (SHA256_DATA_LENGTH - 2)) { /* No room for length in this block. Process it and
- * pad with another one */
- for (i = words; i < SHA256_DATA_LENGTH; i++)
- data[i] = 0;
- sha256_transform(ctx->state, data);
- for (i = 0; i < (SHA256_DATA_LENGTH - 2); i++)
- data[i] = 0;
- } else
- for (i = words; i < SHA256_DATA_LENGTH - 2; i++)
- data[i] = 0;
-
- /* There are 512 = 2^9 bits in one block */
- data[SHA256_DATA_LENGTH - 2] =
- (ctx->count_high << 9) | (ctx->count_low >> 23);
- data[SHA256_DATA_LENGTH - 1] =
- (ctx->count_low << 9) | (ctx->index << 3);
- sha256_transform(ctx->state, data);
-}
-
-void sha256_digest(const struct sha256_ctx *ctx, byte * s)
-{
- int i;
-
- if (s!=NULL)
- for (i = 0; i < _SHA256_DIGEST_LENGTH; i++) {
- *s++ = ctx->state[i] >> 24;
- *s++ = 0xff & (ctx->state[i] >> 16);
- *s++ = 0xff & (ctx->state[i] >> 8);
- *s++ = 0xff & ctx->state[i];
- }
-}
-
