RC4算法c/c++语言实现-Toy模板网

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一.RC4算法

参考RC4加密算法的过程代入例子计算

二.c语言实现

#include <stdio.h>
#include <string.h>
unsigned char sbox[256] = { 0 };
void swap(unsigned char* a, unsigned char* b)
{
	unsigned char tmp = *a;
	*a = *b;
	*b = tmp;
}
void init_sbox( unsigned char key[]) {
	for (unsigned int i = 0; i < 256; i++)//赋值
		sbox[i] = i;
	unsigned int keyLen = strlen((char*)key);
	unsigned char Ttable[256] = { 0 };
	for (int i = 0; i < 256; i++)
		Ttable[i] = key[i % keyLen];//根据初始化t表
	for (int j = 0, i = 0; i < 256; i++)
	{
		j = (j + sbox[i] + Ttable[i]) % 256;	//打乱s盒
		swap(sbox[i], sbox[j]);
	}
}
void RC4_enc_dec(unsigned char data[],unsigned char key[]){
	unsigned char k, i = 0, j = 0, t;
	init_sbox(key);
	unsigned int dataLen = strlen((char*)data);
	for (unsigned h = 0; h < dataLen; h++)
	{
		i = (i + 1) % 256;
		j = (j + sbox[i]) % 256;
		swap(sbox[i], sbox[j]);
		t = (sbox[i] + sbox[j]) % 256;
		k = sbox[t];	//求密钥流,并对明文加密
		data[h] ^= k;	
	}
}

int main()
{
	unsigned char data[1000] = { 0 };
	unsigned char key[100] = { 0 };
	printf("请输入需要加密的明文:\n");
	scanf("%s", data);
	printf("请输入密钥key:\n");
	scanf("%s", key);
	RC4_enc_dec(data, key);
	printf("加密后的密文是:\n,%s",data);
	RC4_enc_dec(data, key);
	printf("解密后的明文是:\n%s", data);
	return 0;
}

运行效果:

c++ rc4,Crypto,c++,c语言,算法,学习,经验分享

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三.c++实现

#include <iostream>
#include <string>
using namespace std;
class RC4 {
private:
	unsigned char s[256];
	void swap(unsigned char& a, unsigned char& b)
	{
		unsigned char tmp = a;
		a = b;
		b = tmp;
	}
	void init_sbox(string key)
	{
		for (unsigned int i = 0; i < 256; i++)	//初始化s盒
			s[i] = i;
		unsigned char T[256] = { 0 };
		unsigned keylen = key.length();
		for (int i = 0; i < 256; i++)
			T[i] = key[i % keylen];				//根据密钥初始化t表
		for (int j = 0, i = 0; i < 256; i++)
		{
			j = (j + s[i] + T[i]) % 256;		//打乱s盒
			swap(s[i], s[j]);
		}
	}
public :
	void enc_dec(string& data,string key) {
		init_sbox(key);
		unsigned int datalen = data.length();
		unsigned char k, i = 0, j = 0, t;
		for (unsigned int h = 0; h < datalen; h++)
		{
			i = (i + 1) % 256;
			j = (j + s[i]) % 256;
			swap(s[i], s[j]);
			t = (s[i] + s[j]) % 256;
			k = s[t];
			data[h] ^= k;
		}

	}
};

int main()
{
	RC4 rc4 ;
	string data, key;
	cout << "请输入需要加密的明文:" << endl;
	cin >> data;
	cout << "请输入密钥key:" << endl;
	cin >> key;
	rc4.enc_dec(data, key);
	cout << "加密后的内容是:\n" << data << endl;
	rc4.enc_dec(data, key);
	cout << "解密后的内容是:\n" << data << endl;
	return 0;
}

运行效果:

c++ rc4,Crypto,c++,c语言,算法,学习,经验分享