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],