SM4密碼算法（附源碼）

時間 2019-12-08

標籤 sm4 密碼算法源碼简体版

原文原文鏈接

SM4是咱們本身國家的一個分組密碼算法，是國家密碼管理局於2012年發佈的。網址戳→_→：http://www.cnnic .NET.cn/jscx/mixbz/sm4/php

具體的密碼標準和算法官方有很是詳盡的PDF文檔以供查閱，戳→_→：http://218.241.108.63/wiki/images/2/22/SM4%E5%88%86%E7%BB%84%E5%AF%86%E7%A0%81%E7%AE%97%E6%B3%95.pdfhtml

算法的源碼實現官方也有相應的示例源碼，戳→_→：算法

http://218.241.108.63/wiki/index.PHP/File:Sm2_sm3_sm4_c%E8%AF%AD%E8%A8%80%E5%AE%9E%E7%8E%B0.zip數組

先說說啥是分組密碼算法：函數

分組密碼算法——國際DES、國產SM4測試

分組密碼就是將明文數據按固定長度進行分組，而後在同一密鑰控制下逐組進行加密，從而將各個明文分組變換成一個等長的密文分組的密碼。其中二進制明文分組的長度稱爲該分組密碼的分組規模。加密

SM4密碼算法的總體結構圖以下：spa

在SM4的源代碼中存在以下幾個函數:.net

void sm4_setkey_enc(sm4_context *ctx，unsigned char key[16])3d

void sm4_setkey_dec(sm4_context *ctx，unsigned char key[16])

void sm4_crypt_ecb( sm4_context *ctx,int mode,int length, unsigned char *input,unsigned char *output)

void sm4_crypt_cbc( sm4_context *ctx,int mode,int length,unsigned char iv[16],unsigned char *input,unsigned char *output )

static void sm4_setkey( unsigned long SK[32], unsigned char key[16] )

還有一個很是重要的結構體：sm4_context

typedef struct

{

int mode; /*!< encrypt/decrypt */

unsigned long sk[32]; /*!< SM4 subkeys */

}

sm4_context;

先說結構體：

sm4_context結構體中的Mode控制是加密仍是解密，sk則表示子密鑰，也稱做輪密鑰。

第一個函數： void sm4_setkey_enc(sm4_context *ctx，unsigned char key[16])

這個函數是用來設置加密密鑰的，一個參數分別爲sm4_context *ctx和一個key。

其內部會調用static void sm4_setkey( unsigned long SK[32], unsigned char key[16] )函數

這個函數是用來設置密鑰的，這個函數內部會對當前傳入的主密鑰進行32輪的迭代，每次迭代的輪密鑰都被存放到ctx結構中的sk數組中。

void sm4_setkey_dec(sm4_context *ctx，unsigned char key[16])函數就是解密函數，過程爲上述過程的逆序過程。

第二個函數：void sm4_crypt_ecb( sm4_context *ctx,int mode,int length, unsigned char

這個函數的做用是使用ecb模式（ECB（Electronic Codebook，電碼本）模式是分組密碼的一種最基本的工做模式。一樣，sm4_crypt_cbc函數則是使用的CBC模式，也就是分組連接模式）來對內容進行加密，內部也是一個循環，根據length的長度來進行循環，每次循環都調用sm4_one_round進行加密或者解密，究竟是加密仍是解密，主要是根據第二個參數Mode來進行決定。

以上就是整個SM4算法的函數簡介，運用這些函數接口，咱們不須要知道內部的具體實現，就能夠使用sm4加密算法來對咱們的數據進行加解密，十分的方便。

/*測試代碼
 * SM4/SMS4 algorithm test programme
 * 2012-4-21
 */

#include <string.h>
#include <stdio.h>
#include "sm4.h"

int main()
{
	unsigned char key[16] = {0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef,0xfe,0xdc,0xba,0x98,0x76,0x54,0x32,0x10};
	unsigned char input[16] = {0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef,0xfe,0xdc,0xba,0x98,0x76,0x54,0x32,0x10};
	unsigned char output[16];
	sm4_context ctx;
	unsigned long i;

	//encrypt standard testing vector
	sm4_setkey_enc(&ctx,key);
	sm4_crypt_ecb(&ctx,1,16,input,output);
	for(i=0;i<16;i++)
		printf("%02x ", output[i]);
	printf("\n");

	//decrypt testing
	sm4_setkey_dec(&ctx,key);
	sm4_crypt_ecb(&ctx,0,16,output,output);
	for(i=0;i<16;i++)
		printf("%02x ", output[i]);
	printf("\n");

	
    return 0;
}

/**
 * \file sm4.h
 */
#ifndef XYSSL_SM4_H
#define XYSSL_SM4_H

#define SM4_ENCRYPT     1
#define SM4_DECRYPT     0

/**
 * \brief          SM4 context structure
 */
typedef struct
{
    int mode;                   /*!<  encrypt/decrypt   */
    unsigned long sk[32];       /*!<  SM4 subkeys       */
}
sm4_context;


#ifdef __cplusplus
extern "C" {
#endif

/**
 * \brief          SM4 key schedule (128-bit, encryption)
 *
 * \param ctx      SM4 context to be initialized
 * \param key      16-byte secret key
 */
void sm4_setkey_enc( sm4_context *ctx, unsigned char key[16] );

/**
 * \brief          SM4 key schedule (128-bit, decryption)
 *
 * \param ctx      SM4 context to be initialized
 * \param key      16-byte secret key
 */
void sm4_setkey_dec( sm4_context *ctx, unsigned char key[16] );

/**
 * \brief          SM4-ECB block encryption/decryption
 * \param ctx      SM4 context
 * \param mode     SM4_ENCRYPT or SM4_DECRYPT
 * \param length   length of the input data
 * \param input    input block
 * \param output   output block
 */
void sm4_crypt_ecb( sm4_context *ctx,
				     int mode,
					 int length,
                     unsigned char *input,
                     unsigned char *output);

#ifdef __cplusplus
}
#endif

#endif /* sm4.h */

/*
 * SM4 Encryption alogrithm (SMS4 algorithm)
 * GM/T 0002-2012 Chinese National Standard ref:http://www.oscca.gov.cn/ 
 * thanks to Xyssl
 * thnaks and refers to http://hi.baidu.com/numax/blog/item/80addfefddfb93e4cf1b3e61.html
 * author:goldboar
 * email:goldboar@163.com
 * 2012-4-20
 */


// Test vector 1
// plain: 01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// key:   01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
//    round key and temp computing result:
//    rk[ 0] = f12186f9 X[ 0] = 27fad345
//    rk[ 1] = 41662b61 X[ 1] = a18b4cb2
//    rk[ 2] = 5a6ab19a X[ 2] = 11c1e22a
//    rk[ 3] = 7ba92077 X[ 3] = cc13e2ee
//    rk[ 4] = 367360f4 X[ 4] = f87c5bd5
//    rk[ 5] = 776a0c61 X[ 5] = 33220757
//    rk[ 6] = b6bb89b3 X[ 6] = 77f4c297
//    rk[ 7] = 24763151 X[ 7] = 7a96f2eb
//    rk[ 8] = a520307c X[ 8] = 27dac07f
//    rk[ 9] = b7584dbd X[ 9] = 42dd0f19
//    rk[10] = c30753ed X[10] = b8a5da02
//    rk[11] = 7ee55b57 X[11] = 907127fa
//    rk[12] = 6988608c X[12] = 8b952b83
//    rk[13] = 30d895b7 X[13] = d42b7c59
//    rk[14] = 44ba14af X[14] = 2ffc5831
//    rk[15] = 104495a1 X[15] = f69e6888
//    rk[16] = d120b428 X[16] = af2432c4
//    rk[17] = 73b55fa3 X[17] = ed1ec85e
//    rk[18] = cc874966 X[18] = 55a3ba22
//    rk[19] = 92244439 X[19] = 124b18aa
//    rk[20] = e89e641f X[20] = 6ae7725f
//    rk[21] = 98ca015a X[21] = f4cba1f9
//    rk[22] = c7159060 X[22] = 1dcdfa10
//    rk[23] = 99e1fd2e X[23] = 2ff60603
//    rk[24] = b79bd80c X[24] = eff24fdc
//    rk[25] = 1d2115b0 X[25] = 6fe46b75
//    rk[26] = 0e228aeb X[26] = 893450ad
//    rk[27] = f1780c81 X[27] = 7b938f4c
//    rk[28] = 428d3654 X[28] = 536e4246
//    rk[29] = 62293496 X[29] = 86b3e94f
//    rk[30] = 01cf72e5 X[30] = d206965e
//    rk[31] = 9124a012 X[31] = 681edf34
// cypher: 68 1e df 34 d2 06 96 5e 86 b3 e9 4f 53 6e 42 46
// 
// test vector 2
// the same key and plain 1000000 times coumpting 
// plain:  01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// key:    01 23 45 67 89 ab cd ef fe dc ba 98 76 54 32 10
// cypher: 59 52 98 c7 c6 fd 27 1f 04 02 f8 04 c3 3d 3f 66


#include "sm4.h"
#include <string.h>
#include <stdio.h>


/*
 * 32-bit integer manipulation macros (big endian)
 */
#ifndef GET_ULONG_BE
#define GET_ULONG_BE(n,b,i)                             \
{                                                       \
    (n) = ( (unsigned long) (b)[(i)    ] << 24 )        \
        | ( (unsigned long) (b)[(i) + 1] << 16 )        \
        | ( (unsigned long) (b)[(i) + 2] <<  8 )        \
        | ( (unsigned long) (b)[(i) + 3]       );       \
}
#endif


#ifndef PUT_ULONG_BE
#define PUT_ULONG_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


/*
 *rotate shift left marco definition
 *
 */
#define  SHL(x,n) (((x) & 0xFFFFFFFF) << n)
#define ROTL(x,n) (SHL((x),n) | ((x) >> (32 - n)))


#define SWAP(a,b) { unsigned long t = a; a = b; b = t; t = 0; }


/*
 * Expanded SM4 S-boxes
 /* Sbox table: 8bits input convert to 8 bits output*/
 
static const unsigned char SboxTable[16][16] = 
{
{0xd6,0x90,0xe9,0xfe,0xcc,0xe1,0x3d,0xb7,0x16,0xb6,0x14,0xc2,0x28,0xfb,0x2c,0x05},
{0x2b,0x67,0x9a,0x76,0x2a,0xbe,0x04,0xc3,0xaa,0x44,0x13,0x26,0x49,0x86,0x06,0x99},
{0x9c,0x42,0x50,0xf4,0x91,0xef,0x98,0x7a,0x33,0x54,0x0b,0x43,0xed,0xcf,0xac,0x62},
{0xe4,0xb3,0x1c,0xa9,0xc9,0x08,0xe8,0x95,0x80,0xdf,0x94,0xfa,0x75,0x8f,0x3f,0xa6},
{0x47,0x07,0xa7,0xfc,0xf3,0x73,0x17,0xba,0x83,0x59,0x3c,0x19,0xe6,0x85,0x4f,0xa8},
{0x68,0x6b,0x81,0xb2,0x71,0x64,0xda,0x8b,0xf8,0xeb,0x0f,0x4b,0x70,0x56,0x9d,0x35},
{0x1e,0x24,0x0e,0x5e,0x63,0x58,0xd1,0xa2,0x25,0x22,0x7c,0x3b,0x01,0x21,0x78,0x87},
{0xd4,0x00,0x46,0x57,0x9f,0xd3,0x27,0x52,0x4c,0x36,0x02,0xe7,0xa0,0xc4,0xc8,0x9e},
{0xea,0xbf,0x8a,0xd2,0x40,0xc7,0x38,0xb5,0xa3,0xf7,0xf2,0xce,0xf9,0x61,0x15,0xa1},
{0xe0,0xae,0x5d,0xa4,0x9b,0x34,0x1a,0x55,0xad,0x93,0x32,0x30,0xf5,0x8c,0xb1,0xe3},
{0x1d,0xf6,0xe2,0x2e,0x82,0x66,0xca,0x60,0xc0,0x29,0x23,0xab,0x0d,0x53,0x4e,0x6f},
{0xd5,0xdb,0x37,0x45,0xde,0xfd,0x8e,0x2f,0x03,0xff,0x6a,0x72,0x6d,0x6c,0x5b,0x51},
{0x8d,0x1b,0xaf,0x92,0xbb,0xdd,0xbc,0x7f,0x11,0xd9,0x5c,0x41,0x1f,0x10,0x5a,0xd8},
{0x0a,0xc1,0x31,0x88,0xa5,0xcd,0x7b,0xbd,0x2d,0x74,0xd0,0x12,0xb8,0xe5,0xb4,0xb0},
{0x89,0x69,0x97,0x4a,0x0c,0x96,0x77,0x7e,0x65,0xb9,0xf1,0x09,0xc5,0x6e,0xc6,0x84},
{0x18,0xf0,0x7d,0xec,0x3a,0xdc,0x4d,0x20,0x79,0xee,0x5f,0x3e,0xd7,0xcb,0x39,0x48}
};


/* System parameter */
static const unsigned long FK[4] = {0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc};


/* fixed parameter */
static const unsigned long CK[32] =
{
0x00070e15,0x1c232a31,0x383f464d,0x545b6269,
0x70777e85,0x8c939aa1,0xa8afb6bd,0xc4cbd2d9,
0xe0e7eef5,0xfc030a11,0x181f262d,0x343b4249,
0x50575e65,0x6c737a81,0x888f969d,0xa4abb2b9,
0xc0c7ced5,0xdce3eaf1,0xf8ff060d,0x141b2229,
0x30373e45,0x4c535a61,0x686f767d,0x848b9299,
0xa0a7aeb5,0xbcc3cad1,0xd8dfe6ed,0xf4fb0209,
0x10171e25,0x2c333a41,0x484f565d,0x646b7279
};




/*
 * private function:
 * look up in SboxTable and get the related value.
 * args:    [in] inch: 0x00~0xFF (8 bits unsigned value).
 */
static unsigned char sm4Sbox(unsigned char inch)
{
    unsigned char *pTable = (unsigned char *)SboxTable;
    unsigned char retVal = (unsigned char)(pTable[inch]);
    return retVal;
}


/*
 * private F(Lt) function:
 * "T algorithm" == "L algorithm" + "t algorithm".
 * args:    [in] a: a is a 32 bits unsigned value;
 * return: c: c is calculated with line algorithm "L" and nonline algorithm "t"
 */
static unsigned long sm4Lt(unsigned long ka)
{
    unsigned long bb = 0;
    unsigned long c = 0;
    unsigned char a[4];
unsigned char b[4];
    PUT_ULONG_BE(ka,a,0)
    b[0] = sm4Sbox(a[0]);
    b[1] = sm4Sbox(a[1]);
    b[2] = sm4Sbox(a[2]);
    b[3] = sm4Sbox(a[3]);
GET_ULONG_BE(bb,b,0)
    c =bb^(ROTL(bb, 2))^(ROTL(bb, 10))^(ROTL(bb, 18))^(ROTL(bb, 24));
    return c;
}


/*
 * private F function:
 * Calculating and getting encryption/decryption contents.
 * args:    [in] x0: original contents;
 * args:    [in] x1: original contents;
 * args:    [in] x2: original contents;
 * args:    [in] x3: original contents;
 * args:    [in] rk: encryption/decryption key;
 * return the contents of encryption/decryption contents.
 */
static unsigned long sm4F(unsigned long x0, unsigned long x1, unsigned long x2, unsigned long x3, unsigned long rk)
{
    return (x0^sm4Lt(x1^x2^x3^rk));
}




/* private function:
 * Calculating round encryption key.
 * args:    [in] a: a is a 32 bits unsigned value;
 * return: sk[i]: i{0,1,2,3,...31}.
 */
static unsigned long sm4CalciRK(unsigned long ka)
{
    unsigned long bb = 0;
    unsigned long rk = 0;
    unsigned char a[4];
    unsigned char b[4];
    PUT_ULONG_BE(ka,a,0)
    b[0] = sm4Sbox(a[0]);
    b[1] = sm4Sbox(a[1]);
    b[2] = sm4Sbox(a[2]);
    b[3] = sm4Sbox(a[3]);
GET_ULONG_BE(bb,b,0)
    rk = bb^(ROTL(bb, 13))^(ROTL(bb, 23));
    return rk;
}


static void sm4_setkey( unsigned long SK[32], unsigned char key[16] )
{
    unsigned long MK[4];
    unsigned long k[36];
    unsigned long i = 0;


    GET_ULONG_BE( MK[0], key, 0 );
    GET_ULONG_BE( MK[1], key, 4 );
    GET_ULONG_BE( MK[2], key, 8 );
    GET_ULONG_BE( MK[3], key, 12 );
    k[0] = MK[0]^FK[0];
    k[1] = MK[1]^FK[1];
    k[2] = MK[2]^FK[2];
    k[3] = MK[3]^FK[3];
    for(; i<32; i++)
    {
        k[i+4] = k[i] ^ (sm4CalciRK(k[i+1]^k[i+2]^k[i+3]^CK[i]));
        SK[i] = k[i+4];
}


}


/*
 * SM4 standard one round processing
 *
 */
static void sm4_one_round( unsigned long sk[32],
                    unsigned char input[16],
                    unsigned char output[16] )
{
    unsigned long i = 0;
    unsigned long ulbuf[36];


    memset(ulbuf, 0, sizeof(ulbuf));
    GET_ULONG_BE( ulbuf[0], input, 0 )
    GET_ULONG_BE( ulbuf[1], input, 4 )
    GET_ULONG_BE( ulbuf[2], input, 8 )
    GET_ULONG_BE( ulbuf[3], input, 12 )
    while(i<32)
    {
        ulbuf[i+4] = sm4F(ulbuf[i], ulbuf[i+1], ulbuf[i+2], ulbuf[i+3], sk[i]);
// #ifdef _DEBUG
//        printf("rk(%02d) = 0x%08x,  X(%02d) = 0x%08x \n",i,sk[i], i, ulbuf[i+4] );
// #endif
    i++;
    }
PUT_ULONG_BE(ulbuf[35],output,0);
PUT_ULONG_BE(ulbuf[34],output,4);
PUT_ULONG_BE(ulbuf[33],output,8);
PUT_ULONG_BE(ulbuf[32],output,12);
}


/*
 * SM4 key schedule (128-bit, encryption)
 */
void sm4_setkey_enc( sm4_context *ctx, unsigned char key[16] )
{
    ctx->mode = SM4_ENCRYPT;
sm4_setkey( ctx->sk, key );
}


/*
 * SM4 key schedule (128-bit, decryption)
 */
void sm4_setkey_dec( sm4_context *ctx, unsigned char key[16] )
{
    int i;
ctx->mode = SM4_ENCRYPT;
    sm4_setkey( ctx->sk, key );
    for( i = 0; i < 16; i ++ )
    {
        SWAP( ctx->sk[ i ], ctx->sk[ 31-i] );
    }
}




/*
 * SM4-ECB block encryption/decryption
 */


void sm4_crypt_ecb( sm4_context *ctx,
   int mode,
   int length,
   unsigned char *input,
                   unsigned char *output)
{
    while( length > 0 )
    {
        sm4_one_round( ctx->sk, input, output );
        input  += 16;
        output += 16;
        length -= 16;
    }


}