SM4加解密

SM4加解密

sm4是一种分组密码,分组长度和密钥长度都为128比特

相关算法

  • s盒代换:以字节为单位进行非线性替换,输入字节的前四位和后四位确定s盒中替换的字节。
    如:若输入e2则代换为f2
--- 2 3
e f2 a3
6 71 32
  • 线性变化:主要是移位运算和异或运算,输入输出都为32位。例如B为32位,则运算为B⊕(B<<<2) ⊕(B<<<10) ⊕(B<<<18) ⊕(B<<<24)
  • 密钥扩展算法:输入128位的密钥,进行32轮迭代,每一轮产生一个32位的轮密钥,共产生32个轮密钥。先进行(k0,k1,k2,k3)=(mk0⊕fk0,mk1⊕fk1,mk2⊕fk2, mk3⊕fk3),然后进行32轮迭代,每一轮为rki=ki+4=ki⊕t’(ki+1⊕ki+2⊕ki+3⊕cki)
    其中rki为i轮的密钥,cki与fki都为常数,t’运算为先进行s盒代换,然后进行线性变化,只不过这里的线性变化为B⊕(B<<<13) ⊕(B<<<23)。
  • 加密算法:输入为128位,即4个32位的字,输出也为128位。共有32轮迭代,每一轮使用一个32位的轮密钥。每一轮的运算为x0⊕t(x1⊕x2⊕x3⊕rk)。之后将得到的x35,x34,x33,x32再进行一个反序处理,作为密文。
    其中rk为该轮轮密钥,x0,x1,x2,x3为4个32位的字,t运算包含s盒代换和线性变换,即每一轮的运算为x0⊕[s(B)] ⊕[s(B)<<<2] ⊕[s(B)<<<10] ⊕[s(B)<<<18] ⊕ [s(B)<<<24] ,B为x1⊕x2⊕x3⊕rk
  • 解密算法:与加密算法相同。只是轮密钥的使用顺序相反。

实现说明

  • 密钥生成采用java中内置的能生成强伪随机数的函数
    SecureRandom random = new SecureRandom(); random.nextBytes(key_byte);
    需要导入import java.security.SecureRandom;
  • 生成的密钥及密文都以整数的形式输出,因为Java的int等数据类型都为无符号的,所以可能有负值
  • 程序只是对一个分组进行加解密,不涉及cbc等分组模式

源代码

加密

package sm4;

import java.security.SecureRandom;
import java.util.Scanner;

public class sm4 {

	public static void main(String[] args) {
		int strint[]=new int[36];
		int m=0;
		int n=0;	
		int s=0;
		int key_int[]=new int[4];
		byte key_byte[]=new byte [16];
		int key_kozhan[]=new int[32];
		char miwen[]=new char[16];
		
		//输入16个字符
		System.out.println("请输入16个字符 ");
		Scanner in = new Scanner(System.in);
		String str = in.next();//获得输入的字符串
		byte strbyte[] = str.getBytes();//将字符串转换为Byte数组
		//将8位的Byte数组,4个4个合并,合并为4个32位的字
		while(m<4) {
			strint[m]=kozhan(strbyte[4*m],strbyte[4*m+1],strbyte[4*m+2],strbyte[4*m+3]);
			m++;
		}
		
		//用java自带的函数生成强伪随机数
		SecureRandom random = new SecureRandom();
		random.nextBytes(key_byte);
		//将8位的密钥Byte数组,4个4个合并,合并为4个32位的字
		while(n<4) {
			key_int[n]=kozhan(key_byte[4*n],key_byte[4*n+1],key_byte[4*n+2],key_byte[4*n+3]);
			n++;
		}
		System.out.print("密钥为");
		for(int i=0;i<4;i++) {
			System.out.print(key_int[i]+" ");
		}
		//密钥扩展
		key_kozhan=key_kozhan(key_int);
	
		//对明文进行加密
		for(int i=0; i<32;i++) {
			s=s_he((strint[i+1]^strint[i+2]^strint[i+3]^key_kozhan[i]));
			strint[i+4]=strint[i]^s^yiwei(s,2)^yiwei(s,10)^yiwei(s,18)^yiwei(s,24);
		}
		//倒序输出密文
		System.out.println('\n'+"密文为 ");
		for(int i=35;i>=32;i--) {
			System.out.print(strint[i]+" ");
		}
	}
	//将4个8位的Byte合并为一个32位的
	static int kozhan(byte a,byte b,byte c,byte d) {
		int e=0;
		e=(a<<24|b<<16|c<<8|d);
		return e;
	}
	//密钥扩展
	static int[] key_kozhan(int a[]) {
		int key_rk[]=new int[32];//存放的32轮密钥
		//4个常数
		int fk[]= {0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc};
		//32个固定参数
		int ck[]= {
				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
				};
		int s=0;
		int b[]=new int[36];
		for(int q=0;q<4;q++) {
			b[q]=a[q]^fk[q];
		}
		for(int i=0;i<32;i++) {
			s=s_he((b[i+1]^b[i+2]^b[i+3]^ck[i]));
			key_rk[i]=b[i]^s^yiwei(s,13)^yiwei(s,23);
			b[i+4]=key_rk[i];
		}
		return  key_rk;
		};
	//移位操作,b为移动的位数
	static int yiwei(int a,int b) {
		a=(byte)((a>>32-b)|(a<<b));
		return a;
	}
	//s盒变换
	static int s_he(int a) {
		//s盒的参数
		int s[][]={
				{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}
	};
		byte b[]=new byte [4];
		int c[]=new int[8];
		//将32位分成8个4位的数
		c[0]=(a&0xf0000000)>>28;
	    c[1]=(a&0x0f000000)>>24;
		c[2]=(a&0x00f00000)>>20;
	    c[3]=(a&0x000f0000)>>16;
		c[4]=(a&0x0000f000)>>12;
		c[5]=(a&0x00000f00)>>8;
		c[6]=(a&0x000000f0)>>4;
		c[7]=a&0x0000000f;
		//java中Int为带符号的32位,可能为负,将负值转换为正值
		for(int i=0;i<8;i++) {
			if(c[i]<0) {
				c[i]=(int) Math.sqrt(c[i]*c[i]);
				}
		}
		//变换操作
		b[0]=(byte)s[c[0]][c[1]];
		b[1]=(byte)s[c[2]][c[3]];
		b[2]=(byte)s[c[4]][c[5]];
		b[3]=(byte)s[c[6]][c[7]];
		//将4个8位字节合并为一个字
		a=(b[0]<<24|b[1]<<16|b[2]<<8|b[3]);
		return a;
	}
}

解密

package sm4;

import java.util.Scanner;

public class sm4de {
	public static void main(String[] args) {
		int strint[]=new int[36];
		int s=0;
		int key_int[]=new int[16];
		int key_kozhan[]=new int[32];
		char mingwen[]=new char[16];
		
		Scanner in = new Scanner(System.in);
		System.out.println("请输入密文 ");
		for(int i=0;i<4;i++) {
			strint[i] = in.nextInt();//获得输入的密文
		}
		System.out.println("请输入密钥 ");
		for(int i=0;i<4;i++) {
			key_int[i] = in.nextInt();//获得输入的密钥
		}
		//密钥扩展
		key_kozhan=key_kozhan(key_int);
		
		//对明文进行解密
		for(int i=0; i<32;i++) {
			s=s_he((strint[i+1]^strint[i+2]^strint[i+3]^key_kozhan[31-i]));
			strint[i+4]=strint[i]^s^yiwei(s,2)^yiwei(s,10)^yiwei(s,18)^yiwei(s,24);
		}
		//倒序输出明文
		System.out.println("明文为 ");
		for(int i=35;i>=32;i--) {
			mingwen=shuchu(strint[i]);
			for(int j=0;j<4;j++) {
				System.out.print(mingwen[j]);
			}
		}
	}
	//将4个8位的Byte合并为一个32位的
	static int kozhan(byte a,byte b,byte c,byte d) {
		int e=0;
		e=(a<<24|b<<16|c<<8|d);
		return e;
	}
	//密钥扩展
	static int[] key_kozhan(int a[]) {
		int key_rk[]=new int[32];//存放的32轮密钥
		//4个常数
		int fk[]= {0xa3b1bac6,0x56aa3350,0x677d9197,0xb27022dc};
		//32个固定参数
		int ck[]= {
				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
				};
		int s=0;
		int b[]=new int[36];
		for(int q=0;q<4;q++) {
			b[q]=a[q]^fk[q];
		}
		for(int i=0;i<32;i++) {
			s=s_he((b[i+1]^b[i+2]^b[i+3]^ck[i]));
			key_rk[i]=b[i]^s^yiwei(s,13)^yiwei(s,23);
			b[i+4]=key_rk[i];
		}
		return  key_rk;
		};
	//移位操作,b为移动的位数
	static int yiwei(int a,int b) {
		a=(byte)((a>>32-b)|(a<<b));
		return a;
	}
	//s盒变换
	static int s_he(int a) {
		//s盒的参数
		int s[][]={
				{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}
	};
		byte b[]=new byte [4];
		int c[]=new int[8];
		//将32位分成8个4位的数
		c[0]=(a&0xf0000000)>>28;
	    c[1]=(a&0x0f000000)>>24;
		c[2]=(a&0x00f00000)>>20;
	    c[3]=(a&0x000f0000)>>16;
		c[4]=(a&0x0000f000)>>12;
		c[5]=(a&0x00000f00)>>8;
		c[6]=(a&0x000000f0)>>4;
		c[7]=a&0x0000000f;
		//java中Int为带符号的32位,可能为负,将负值转换为正值
		for(int i=0;i<8;i++) {
			if(c[i]<0) {
				c[i]=(int) Math.sqrt(c[i]*c[i]);
				}
		}
		//变换操作
		b[0]=(byte)s[c[0]][c[1]];
		b[1]=(byte)s[c[2]][c[3]];
		b[2]=(byte)s[c[4]][c[5]];
		b[3]=(byte)s[c[6]][c[7]];
		//将4个8位字节合并为一个字
		a=(b[0]<<24|b[1]<<16|b[2]<<8|b[3]);
		return a;
	}
	static char[] shuchu(int a){
		char b[]=new char[4];
		b[0]=(char) ((a&0xff000000)>>24);
		b[1]=(char) ((a&0x00ff0000)>>16);
		b[2]=(char) ((a&0x0000ff00)>>8);
		b[3]=(char)(a&0x000000ff);
		return b;
	}
}

运行效果

posted @ 2019-07-20 19:07  启林O_o  阅读(5078)  评论(0编辑  收藏  举报