加密字符串

#include <stdio.h>

/// <summary>
/// 两次异或法加密字符串，缺陷是ch变量的字符不能出现在key中，不然计算成0，无法还原
/// </summary>
/// <param name="ch"></param>
/// <param name="key"></param>
void EncryptAndDecode(char ch[], char key[])
{
	for (int i = 0; ch[i]; ++i)
		ch[i] ^= key[i % 7];
}

/// <summary>
/// 四位前后两位相互交换法，加密字符串
/// </summary>
/// <param name="ch"></param>
void EncryptAndDecode2(unsigned char ch[])
{
	for (int i = 0; ch[i]; ++i)
		ch[i] = (ch[i] << 4) | (ch[i] >> 4);
}

/// <summary>
/// 转化成16进制加密法
/// </summary>
void EncryptAndDecode3()
{
	unsigned char ch[] = "原始字符串";
	for (int i = 0; ch[i]; ++i)
		printf("0x%x,", ch[i]);//转化成16进制
	printf("\n");
	//unsigned char 保证输出的16进制数是两位的，不然就是8位的
	char chr[] = { 0xce,0xd2,0xb0,0xae,0xc4,0xe3,0xd6,0xd0,0xb9,0xfa,00 };//这里存放上面的16进制
	printf("%s", chr);//这里又还原成原字符串
}

void test1()
{
	char key[] = { '[',']','{','}','<','>','|' };
	char ch[] = "我爱你中国";
	printf("%s\n", ch);
	EncryptAndDecode(ch, key);
	printf("%s\n", ch);
	EncryptAndDecode(ch, key);
	printf("%s\n", ch);
}

void test2()
{
	unsigned char ch[] = "我爱你中国";
	EncryptAndDecode2(ch);
	printf("%s\n\n", ch);
	EncryptAndDecode2(ch);
	printf("%s\n\n", ch);
}

int main()
{
	//test1();
	//test2();
	EncryptAndDecode3();
	getchar();
	return 0;
}