SHA家族的五个算法，分别是SHA-1、SHA-224、SHA-256、SHA-384，和SHA-512，由美国国家安全局（NSA）所设计，并由美国国家标准与技术研究院（NIST）发布，是美国的政府标准。
哈希算法使用比较广泛，具体算法原理就不再赘述，这里只是记录一下C语言的源码和使用。
以下先是SHA1的算法
/*
* FIPS-180-1 compliant SHA-1 implementation
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "stdafx.h"
#include "sha1.h"
#include <string.h>
#include <stdio.h>
/* Implementation that should never be optimized out by the compiler */
static void zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char*)v; while( n-- ) *p++ = 0;
}
/*
* 32-bit integer manipulation macros (big endian)
*/
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i) \
{ \
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
| ( (uint32_t) (b)[(i) + 3] ); \
}
#endif
#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i) \
{ \
(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
(b)[(i) + 3] = (unsigned char) ( (n) ); \
}
#endif
void sha1_init( sha1_context *ctx )
{
memset( ctx, 0, sizeof( sha1_context ) );
}
void sha1_free( sha1_context *ctx )
{
if( ctx == NULL )
return;
zeroize( ctx, sizeof( sha1_context ) );
}
void sha1_clone( sha1_context *dst,
const sha1_context *src )
{
*dst = *src;
}
/*
* SHA-1 context setup
*/
void sha1_starts( sha1_context *ctx )
{
ctx->total[0] = 0;
ctx->total[1] = 0;
ctx->state[0] = 0x67452301;
ctx->state[1] = 0xEFCDAB89;
ctx->state[2] = 0x98BADCFE;
ctx->state[3] = 0x10325476;
ctx->state[4] = 0xC3D2E1F0;
}
#if !defined(MBEDTLS_SHA1_PROCESS_ALT)
void sha1_process( sha1_context *ctx, const unsigned char data[64] )
{
uint32_t temp, W[16], A, B, C, D, E;
GET_UINT32_BE( W[ 0], data, 0 );
GET_UINT32_BE( W[ 1], data, 4 );
GET_UINT32_BE( W[ 2], data, 8 );
GET_UINT32_BE( W[ 3], data, 12 );
GET_UINT32_BE( W[ 4], data, 16 );
GET_UINT32_BE( W[ 5], data, 20 );
GET_UINT32_BE( W[ 6], data, 24 );
GET_UINT32_BE( W[ 7], data, 28 );
GET_UINT32_BE( W[ 8], data, 32 );
GET_UINT32_BE( W[ 9], data, 36 );
GET_UINT32_BE( W[10], data, 40 );
GET_UINT32_BE( W[11], data, 44 );
GET_UINT32_BE( W[12], data, 48 );
GET_UINT32_BE( W[13], data, 52 );
GET_UINT32_BE( W[14], data, 56 );
GET_UINT32_BE( W[15], data, 60 );
#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
#define R(t) \
( \
temp = W[( t - 3 ) & 0x0F] ^ W[( t - 8 ) & 0x0F] ^ \
W[( t - 14 ) & 0x0F] ^ W[ t & 0x0F], \
( W[t & 0x0F] = S(temp,1) ) \
)
#define P(a,b,c,d,e,x) \
{ \
e += S(a,5) + F(b,c,d) + K + x; b = S(b,30); \
}
A = ctx->state[0];
B = ctx->state[1];
C = ctx->state[2];
D = ctx->state[3];
E = ctx->state[4];
#define F(x,y,z) (z ^ (x & (y ^ z)))
#define K 0x5A827999
P( A, B, C, D, E, W[0] );
P( E, A, B, C, D, W[1] );
P( D, E, A, B, C, W[2] );
P( C, D, E, A, B, W[3] );
P( B, C, D, E, A, W[4] );
P( A, B, C, D, E, W[5] );
P( E, A, B, C, D, W[6] );
P( D, E, A, B, C, W[7] );
P( C, D, E, A, B, W[8] );
P( B, C, D, E, A, W[9] );
P( A, B, C, D, E, W[10] );
P( E, A, B, C, D, W[11] );
P( D, E, A, B, C, W[12] );
P( C, D, E, A, B, W[13] );
P( B, C, D, E, A, W[14] );
P( A, B, C, D, E, W[15] );
P( E, A, B, C, D, R(16) );
P( D, E, A, B, C, R(17) );
P( C, D, E, A, B, R(18) );
P( B, C, D, E, A, R(19) );
#undef K
#undef F
#define F(x,y,z) (x ^ y ^ z)
#define K 0x6ED9EBA1
P( A, B, C, D, E, R(20) );
P( E, A, B, C, D, R(21) );
P( D, E, A, B, C, R(22) );
P( C, D, E, A, B, R(23) );
P( B, C, D, E, A, R(24) );
P( A, B, C, D, E, R(25) );
P( E, A, B, C, D, R(26) );
P( D, E, A, B, C, R(27) );
P( C, D, E, A, B, R(28) );
P( B, C, D, E, A, R(29) );
P( A, B, C, D, E, R(30) );
P( E, A, B, C, D, R(31) );
P( D, E, A, B, C, R(32) );
P( C, D, E, A, B, R(33) );
P( B, C, D, E, A, R(34) );
P( A, B, C, D, E, R(35) );
P( E, A, B, C, D, R(36) );
P( D, E, A, B, C, R(37) );
P( C, D, E, A, B, R(38) );
P( B, C, D, E, A, R(39) );
#undef K
#undef F
#define F(x,y,z) ((x & y) | (z & (x | y)))
#define K 0x8F1BBCDC
P( A, B, C, D, E, R(40) );
P( E, A, B, C, D, R(41) );
P( D, E, A, B, C, R(42) );
P( C, D, E, A, B, R(43) );
P( B, C, D, E, A, R(44) );
P( A, B, C, D, E, R(45) );
P( E, A, B, C, D, R(46) );
P( D, E, A, B, C, R(47) );
P( C, D, E, A, B, R(48) );
P( B, C, D, E, A, R(49) );
P( A, B, C, D, E, R(50) );
P( E, A, B, C, D, R(51) );
P( D, E, A, B, C, R(52) );
P( C, D, E, A, B, R(53) );
P( B, C, D, E, A, R(54) );
P( A, B, C, D, E, R(55) );
P( E, A, B, C, D, R(56) );
P( D, E, A, B, C, R(57) );
P( C, D, E, A, B, R(58) );
P( B, C, D, E, A, R(59) );
#undef K
#undef F
#define F(x,y,z) (x ^ y ^ z)
#define K 0xCA62C1D6
P( A, B, C, D, E, R(60) );
P( E, A, B, C, D, R(61) );
P( D, E, A, B, C, R(62) );
P( C, D, E, A, B, R(63) );
P( B, C, D, E, A, R(64) );
P( A, B, C, D, E, R(65) );
P( E, A, B, C, D, R(66) );
P( D, E, A, B, C, R(67) );
P( C, D, E, A, B, R(68) );
P( B, C, D, E, A, R(69) );
P( A, B, C, D, E, R(70) );
P( E, A, B, C, D, R(71) );
P( D, E, A, B, C, R(72) );
P( C, D, E, A, B, R(73) );
P( B, C, D, E, A, R(74) );
P( A, B, C, D, E, R(75) );
P( E, A, B, C, D, R(76) );
P( D, E, A, B, C, R(77) );
P( C, D, E, A, B, R(78) );
P( B, C, D, E, A, R(79) );
#undef K
#undef F
ctx->state[0] += A;
ctx->state[1] += B;
ctx->state[2] += C;
ctx->state[3] += D;
ctx->state[4] += E;
}
/*
* SHA-1 process buffer
*/
void sha1_update( sha1_context *ctx, const unsigned char *input, size_t ilen )
{
size_t fill;
uint32_t left;
if( ilen == 0 )
return;
left = ctx->total[0] & 0x3F;
fill = 64 - left;
ctx->total[0] += (uint32_t) ilen;
ctx->total[0] &= 0xFFFFFFFF;
if( ctx->total[0] < (uint32_t) ilen )
ctx->total[1]++;
if( left && ilen >= fill )
{
memcpy( (void *) (ctx->buffer + left), input, fill );
sha1_process( ctx, ctx->buffer );
input += fill;
ilen -= fill;
left = 0;
}
while( ilen >= 64 )
{
sha1_process( ctx, input );
input += 64;
ilen -= 64;
}
if( ilen > 0 )
memcpy( (void *) (ctx->buffer + left), input, ilen );
}
static const unsigned char sha1_padding[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
};
/*
* SHA-1 final digest
*/
void sha1_finish( sha1_context *ctx, unsigned char output[20] )
{
uint32_t last, padn;
uint32_t high, low;
unsigned char msglen[8];
high = ( ctx->total[0] >> 29 )
| ( ctx->total[1] << 3 );
low = ( ctx->total[0] << 3 );
PUT_UINT32_BE( high, msglen, 0 );
PUT_UINT32_BE( low, msglen, 4 );
last = ctx->total[0] & 0x3F;
padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
sha1_update( ctx, sha1_padding, padn );
sha1_update( ctx, msglen, 8 );
PUT_UINT32_BE( ctx->state[0], output, 0 );
PUT_UINT32_BE( ctx->state[1], output, 4 );
PUT_UINT32_BE( ctx->state[2], output, 8 );
PUT_UINT32_BE( ctx->state[3], output, 12 );
PUT_UINT32_BE( ctx->state[4], output, 16 );
}
/*
* output = SHA-1( input buffer )
*/
int sha1( const unsigned char *input, size_t ilen, unsigned char output[20] )
{
sha1_context ctx;
sha1_init( &ctx );
sha1_starts( &ctx );
sha1_update( &ctx, input, ilen );
sha1_finish( &ctx, output );
sha1_free( &ctx );
return 0;
}
数据通过SHA1计算得到20字节长度的哈希值，sha1() 封装用来一次性计算一段字符串的哈希值，如果要采用多步计算的方式，就直接使用该函数内部的这几个接口，如下的一个函数示例：
//test
int sha1_test(unsigned char *hash)
{
int result;
int fd;
unsigned char hashBuf[32];
unsigned char vDecompCache[512]={0};
sha1_context sha1ctx;
sha1_init( &sha1ctx);
sha1_starts( &sha1ctx);
fd = open("/data/test.data",O_RDONLY);
if(fd < 0)
{
perror("open error");
return -1;
}
do
{
result = read(fd, vDecompCache, sizeof(vDecompCache));
sha1_update( &sha1ctx, vDecompCache, result);
}while(result > 0);
sha1_finish(&sha1ctx, hashBuf);
memcpy(hash, hashBuf, 20);
sha1_free( &sha1ctx );
DebugmyAsciiToHex("SHA1:",hashBuf,20);
return 0;
}下边的是SHA256和SHA224的源码：
/*
* FIPS-180-2 compliant SHA-256 implementation
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: GPL-2.0
*
* 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.
*
* This program 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 General Public License for more details.
*
*/
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "stdafx.h"
#include "sha256.h"
/* Implementation that should never be optimized out by the compiler */
static void zeroize( void *v, size_t n ) {
volatile unsigned char *p = (unsigned char *)v; while( n-- ) *p++ = 0;
}
/*
* 32-bit integer manipulation macros (big endian)
*/
#ifndef GET_UINT32_BE
#define GET_UINT32_BE(n,b,i) \
do { \
(n) = ( (uint32_t) (b)[(i) ] << 24 ) \
| ( (uint32_t) (b)[(i) + 1] << 16 ) \
| ( (uint32_t) (b)[(i) + 2] << 8 ) \
| ( (uint32_t) (b)[(i) + 3] ); \
} while( 0 )
#endif
#ifndef PUT_UINT32_BE
#define PUT_UINT32_BE(n,b,i) \
do { \
(b)[(i) ] = (unsigned char) ( (n) >> 24 ); \
(b)[(i) + 1] = (unsigned char) ( (n) >> 16 ); \
(b)[(i) + 2] = (unsigned char) ( (n) >> 8 ); \
(b)[(i) + 3] = (unsigned char) ( (n) ); \
} while( 0 )
#endif
void sha256_init( sha256_context *ctx )
{
memset( ctx, 0, sizeof( sha256_context ) );
}
void sha256_free( sha256_context *ctx )
{
if( ctx == NULL )
return;
zeroize( ctx, sizeof( sha256_context ) );
}
void sha256_clone( sha256_context *dst,
const sha256_context *src )
{
*dst = *src;
}
/*
* SHA-256 context setup
*/
void sha256_starts( sha256_context *ctx, int is224 )
{
ctx->total[0] = 0;
ctx->total[1] = 0;
if( is224 == 0 )
{
/* SHA-256 */
ctx->state[0] = 0x6A09E667;
ctx->state[1] = 0xBB67AE85;
ctx->state[2] = 0x3C6EF372;
ctx->state[3] = 0xA54FF53A;
ctx->state[4] = 0x510E527F;
ctx->state[5] = 0x9B05688C;
ctx->state[6] = 0x1F83D9AB;
ctx->state[7] = 0x5BE0CD19;
}
else
{
/* SHA-224 */
ctx->state[0] = 0xC1059ED8;
ctx->state[1] = 0x367CD507;
ctx->state[2] = 0x3070DD17;
ctx->state[3] = 0xF70E5939;
ctx->state[4] = 0xFFC00B31;
ctx->state[5] = 0x68581511;
ctx->state[6] = 0x64F98FA7;
ctx->state[7] = 0xBEFA4FA4;
}
ctx->is224 = is224;
}
#if !defined(SHA256_PROCESS_ALT)
static const uint32_t K[] =
{
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 SHR(x,n) ((x & 0xFFFFFFFF) >> n)
#define ROTR(x,n) (SHR(x,n) | (x << (32 - n)))
#define S0(x) (ROTR(x, 7) ^ ROTR(x,18) ^ SHR(x, 3))
#define S1(x) (ROTR(x,17) ^ ROTR(x,19) ^ SHR(x,10))
#define S2(x) (ROTR(x, 2) ^ ROTR(x,13) ^ ROTR(x,22))
#define S3(x) (ROTR(x, 6) ^ ROTR(x,11) ^ ROTR(x,25))
#define F0(x,y,z) ((x & y) | (z & (x | y)))
#define F1(x,y,z) (z ^ (x & (y ^ z)))
#define R(t) \
( \
W[t] = S1(W[t - 2]) + W[t - 7] + \
S0(W[t - 15]) + W[t - 16] \
)
#define P(a,b,c,d,e,f,g,h,x,K) \
{ \
temp1 = h + S3(e) + F1(e,f,g) + K + x; \
temp2 = S2(a) + F0(a,b,c); \
d += temp1; h = temp1 + temp2; \
}
void sha256_process( sha256_context *ctx, const unsigned char data[64] )
{
uint32_t temp1, temp2, W[64];
uint32_t A[8];
unsigned int i;
for( i = 0; i < 8; i++ )
A[i] = ctx->state[i];
#if defined(SHA256_SMALLER)
for( i = 0; i < 64; i++ )
{
if( i < 16 )
GET_UINT32_BE( W[i], data, 4 * i );
else
R( i );
P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i], K[i] );
temp1 = A[7]; A[7] = A[6]; A[6] = A[5]; A[5] = A[4]; A[4] = A[3];
A[3] = A[2]; A[2] = A[1]; A[1] = A[0]; A[0] = temp1;
}
#else /* SHA256_SMALLER */
for( i = 0; i < 16; i++ )
GET_UINT32_BE( W[i], data, 4 * i );
for( i = 0; i < 16; i += 8 )
{
P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], W[i+0], K[i+0] );
P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], W[i+1], K[i+1] );
P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], W[i+2], K[i+2] );
P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], W[i+3], K[i+3] );
P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], W[i+4], K[i+4] );
P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], W[i+5], K[i+5] );
P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], W[i+6], K[i+6] );
P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], W[i+7], K[i+7] );
}
for( i = 16; i < 64; i += 8 )
{
P( A[0], A[1], A[2], A[3], A[4], A[5], A[6], A[7], R(i+0), K[i+0] );
P( A[7], A[0], A[1], A[2], A[3], A[4], A[5], A[6], R(i+1), K[i+1] );
P( A[6], A[7], A[0], A[1], A[2], A[3], A[4], A[5], R(i+2), K[i+2] );
P( A[5], A[6], A[7], A[0], A[1], A[2], A[3], A[4], R(i+3), K[i+3] );
P( A[4], A[5], A[6], A[7], A[0], A[1], A[2], A[3], R(i+4), K[i+4] );
P( A[3], A[4], A[5], A[6], A[7], A[0], A[1], A[2], R(i+5), K[i+5] );
P( A[2], A[3], A[4], A[5], A[6], A[7], A[0], A[1], R(i+6), K[i+6] );
P( A[1], A[2], A[3], A[4], A[5], A[6], A[7], A[0], R(i+7), K[i+7] );
}
#endif /* SHA256_SMALLER */
for( i = 0; i < 8; i++ )
ctx->state[i] += A[i];
}
#endif /* !SHA256_PROCESS_ALT */
/*
* SHA-256 process buffer
*/
void sha256_update( sha256_context *ctx, const unsigned char *input,
size_t ilen )
{
size_t fill;
uint32_t left;
if( ilen == 0 )
return;
left = ctx->total[0] & 0x3F;
fill = 64 - left;
ctx->total[0] += (uint32_t) ilen;
ctx->total[0] &= 0xFFFFFFFF;
if( ctx->total[0] < (uint32_t) ilen )
ctx->total[1]++;
if( left && ilen >= fill )
{
memcpy( (void *) (ctx->buffer + left), input, fill );
sha256_process( ctx, ctx->buffer );
input += fill;
ilen -= fill;
left = 0;
}
while( ilen >= 64 )
{
sha256_process( ctx, input );
input += 64;
ilen -= 64;
}
if( ilen > 0 )
memcpy( (void *) (ctx->buffer + left), input, ilen );
}
static const unsigned char sha256_padding[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
};
/*
* SHA-256 final digest
*/
void sha256_finish( sha256_context *ctx, unsigned char output[32] )
{
uint32_t last, padn;
uint32_t high, low;
unsigned char msglen[8];
high = ( ctx->total[0] >> 29 )
| ( ctx->total[1] << 3 );
low = ( ctx->total[0] << 3 );
PUT_UINT32_BE( high, msglen, 0 );
PUT_UINT32_BE( low, msglen, 4 );
last = ctx->total[0] & 0x3F;
padn = ( last < 56 ) ? ( 56 - last ) : ( 120 - last );
sha256_update( ctx, sha256_padding, padn );
sha256_update( ctx, msglen, 8 );
PUT_UINT32_BE( ctx->state[0], output, 0 );
PUT_UINT32_BE( ctx->state[1], output, 4 );
PUT_UINT32_BE( ctx->state[2], output, 8 );
PUT_UINT32_BE( ctx->state[3], output, 12 );
PUT_UINT32_BE( ctx->state[4], output, 16 );
PUT_UINT32_BE( ctx->state[5], output, 20 );
PUT_UINT32_BE( ctx->state[6], output, 24 );
if( ctx->is224 == 0 )
PUT_UINT32_BE( ctx->state[7], output, 28 );
}
/*
* output = SHA-256( input buffer )
*/
void sha256( const unsigned char *input, size_t ilen,
unsigned char output[32], int is224 )
{
sha256_context ctx;
sha256_init( &ctx );
sha256_starts( &ctx, is224 );
sha256_update( &ctx, input, ilen );
sha256_finish( &ctx, output );
sha256_free( &ctx );
}
//test
void sha256_test_self()
{
char *data = "a761350e210c0f30ad5b93e3584f543a";
unsigned char buff[32] = {0};
printf("%s\n",data);
sha256((unsigned char *)data,strlen((char*)data),buff,0);
for(int i = 0;i < 32;i++)
{
printf("%02X",buff[i]);
}
printf("\r\n");
}这个接口同SHA1，SHA256生成32字节，也可以使用多步生成一个文件的哈希256值，如下测试示例：
//test
int sha256_test(unsigned char *hash)
{
int result;
int fd;
unsigned char hashBuf[32];
unsigned char vDecompCache[512]={0};
sha256_context sha256ctx;
sha256_init( &sha256ctx);
sha256_starts( &sha256ctx, 0);
fd = open("/data/test.data",O_RDONLY);
if(fd < 0)
{
perror("open error");
return -1;
}
do
{
result = read(fd, vDecompCache, sizeof(vDecompCache));
sha256_update( &sha1ctx, vDecompCache, result);
}while(result > 0);
sha256_finish(&sha1ctx, hashBuf);
memcpy(hash, hashBuf, 20);
sha256_free( &sha256ctx );
DebugmyAsciiToHex("SHA256:",hashBuf,32);
return 0;
}