[科普中国]-SM4.0- · 科普中国网

SM4.0（原名SMS4.0）是中华人民共和国政府采用的一种分组密码标准，由国家密码管理局于2012年3月21日发布。相关标准为“GM/T 0002-2012《SM4分组密码算法》（原SMS4分组密码算法）”。1

介绍

SM4.0（原名SMS4.0）是中华人民共和国政府采用的一种分组密码标准，由国家密码管理局于2012年3月21日发布。相关标准为“GM/T 0002-2012《SM4分组密码算法》（原SMS4分组密码算法）”。

在商用密码体系中，SM4主要用于数据加密，其算法公开，分组长度与密钥长度均为128bit，加密算法与密钥扩展算法都采用32轮非线性迭代结构，S盒为固定的8比特输入8比特输出。

SM4.0中的指令长度被提升到大于64K（即64×1024）的水平，这是SM 3.0规格（渲染指令长度允许大于512）的128倍。

相关概念

在密码学中，分组加密（英语：Block cipher），又称分块加密或块密码，是一种对称密钥算法。它将明文分成多个等长的模块（block），使用确定的算法和对称密钥对每组分别加密解密。分组加密是极其重要的加密协议组成，其中典型的如DES和AES作为美国政府核定的标准加密算法，应用领域从电子邮件加密到银行交易转帐，非常广泛。

国密即国家密码局认定的国产密码算法。主要有SM1，SM2，SM3，SM4。密钥长度和分组长度均为128位。

SM1为对称加密。其加密强度与AES相当。该算法不公开，调用该算法时，需要通过加密芯片的接口进行调用。

SM2为非对称加密，基于ECC。该算法已公开。由于该算法基于ECC，故其签名速度与秘钥生成速度都快于RSA。ECC 256位（SM2采用的就是ECC 256位的一种）安全强度比RSA 2048位高，但运算速度快于RSA。

SM3消息摘要。可以用MD5作为对比理解。该算法已公开。校验结果为256位。

SM4无线局域网标准的分组数据算法。对称加密，密钥长度和分组长度均为128位。

源代码C/C++#define HEADER_SM4_H#define HEADER_SM4_H#ifdef __cplusplusextern "C" {#endiftypedef unsigned char muint8;typedef unsigned long muint32;#define LITTLE_ENDIAN //定义小端字节序//#define BIG_ENDIAN //定义大端字节序#define SM4_ENCRYPT 1 //定义加密标志#define SM4_DECRYPT 0 //定义解密标志#define SM4_BLOCK_LEN 16#define SM4_KEY_LEN 16#define SM4_IV_LEN SM4_BLOCK_LEN// SM4的密钥扩展算法// 参数说明：Key为加密密钥，rk为子密钥，CryptFlag为加解密标志int SM4KeyExt(const muint8 *Key, muint32 *rk, muint32 CryptFlag);// SM4的加解密函数// 参数说明：Input为输入信息分组，Output为输出分组，rk为轮密钥int SM4Crypt(const muint8 *Input, muint8 *Output, const muint32 *rk);//For EVPvoid sm4_set_key(muint32 *rk, const unsigned char *data, int enc);void sm4_ecb_encrypt(char *in, char *out, const muint32 *rk,int enc);void sm4_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,const muint32 *rk, unsigned char *iv, int enc);void sm4_cfb64_encrypt(const unsigned char *in, unsigned char *out,long length, const muint32 *rk, unsigned char *ivec,int *num, int enc);void sm4_ofb64_encrypt(const unsigned char *in, unsigned char *out,long length, const muint32 *rk, unsigned char *ivec,int *num);#ifdef __cplusplus}#endif#endif#include "sm4.h"#include//muint32 rk[32];//作为加解密上下文const muint8 Sbox[256] = {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};const muint32 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 };#define Rotl(_x, _y) (((_x) (32 - (_y))))#define ByteSub(_A) (Sbox[(_A) >> 24 & 0xFF] 16 & 0xFF] 8 & 0xFF]