DES的雪崩效应分析

明文固定，密钥改变一个字节

假定明文为11111111（00000001 00000001 00000001 00000001 00000001 00000001 00000001 00000001）；
密钥为12345678（00000001 00000010 00000011 00000100 00000101 00000110 00000111 00001000）。
密钥变动为10345678（00000001 00000000 00000011 00000100 00000101 00000110 00000111 00001000）仅变动一位。

进行分析：

使用原密钥12345678加密后的最终结果为：
D 6 9 0 F 1 E E 3 4 B C 5 5 4 5
使用变动后密钥10345678加密后的最终结果为：
4 7 B 3 6 1 5 5 A 5 B 3 1 5 2 A
每一轮数出的加密结果详见附录A，通过统计分析，得到每一轮的加密结果差异bit位数如下表所示：

加密轮数	1	2	3	4	5	6	7	8
密文相差bit数	4	18	29	29	30	28	28	28

加密轮数	9	10	11	12	13	14	15	16
密文相差bit数	29	30	27	31	32	29	28	28

密钥固定，明文改变一个字节

假定密钥为11111111（00000001 00000001 00000001 00000001 00000001 00000001 00000001 00000001）；
明文为12345678（00000001 00000010 00000011 00000100 00000101 00000110 00000111 00001000）。
明文变动为10345678（00000001 00000000 00000011 00000100 00000101 00000110 00000111 00001000）仅变动一位。

进行分析：

将原明文12345678加密后的最终结果为：
9 9 F B 3 C A 8 1 4 2 E 8 3 2 1
将变动后的明文10345678加密后的最终结果为：
2 7 8 B F B E 1 9 F 8 D 7 2 3 6
每一轮数出的加密结果详见附录A，通过统计分析，得到每一轮的加密结果差异bit位数如下表所示：
通过统计分析，可以得到

加密轮数	1	2	3	4	5	6	7	8
密文相差bit数	1	4	15	31	33	33	37	34

加密轮数	9	10	11	12	13	14	15	16
密文相差bit数	32	37	37	33	28	30	36	34

由此可以看出，DES加密具有雪崩效应。

设计Feistel结构密码

Feistel密码结构设计思路：

• 令\(F\)为轮函数；
• 令\(K_1,K_2,\cdots,K_i,\cdots,K_n\)分别为第\(1,2,\cdots,i,\cdots,n\)轮的子密钥。
• 在每一轮中，将明文信息均分为两块\((L_0,R_0)\)；
• 加密过程：\(L_i = R_{i-1}; R_i = L_{i-1} \oplus F(R_{i-1},K_i)\)
• 解密过程：\(R_{i-1} = L_i; L_{i-1} = R_i\oplus F(R_{i-1},K_i) = R_i\oplus F(L_i,K_i)\)



与DES不同的设计

密钥设计

密钥总长度为192bit，设置时字符均为标准ASCII字符。密钥前128位和后64位组合，实现CM方式加密。

轮密钥生成

取出密钥前128bit，分为左64bit和右64bit，每一轮加密过程中，左右64bit循环左移4位。将移位后的左右半密钥做模2加运算。同时，在每轮中，密钥的后64bit循环左移4位。将两部分做模2加运算。最终得到64bit密钥。对于得到的64bit密钥，将其分为四段，每段16bit，做模2加运算后得到16bit密钥，扩展三倍，得到每轮所需要的轮密钥。
过程如下图所示



程序测试：



相关代码详见附录B

附录A

原密钥加密各轮产生的密文bit

1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 0 0 1 0 0 1 1 1 0 1 1 1 1 1 1 0 1 1 0 0 0 0 0 1 0 0 0 1 1
1 1 1 0 0 1 0 0 1 1 1 0 1 1 1 1 1 1 0 1 1 0 0 0 0 0 1 0 0 0 1 1 0 1 0 1 0 0 0 1 0 0 1 0 1 0 1 0 0 0 1 1 1 1 1 0 0 0 0 1 0 1 0 1
0 1 0 1 0 0 0 1 0 0 1 0 1 0 1 0 0 0 1 1 1 1 1 0 0 0 0 1 0 1 0 1 1 0 0 1 1 0 1 1 1 1 0 0 1 0 0 0 0 0 0 1 1 1 0 0 0 0 0 1 0 0 0 1
1 0 0 1 1 0 1 1 1 1 0 0 1 0 0 0 0 0 0 1 1 1 0 0 0 0 0 1 0 0 0 1 0 1 1 0 0 1 1 0 0 1 1 0 1 0 0 0 0 0 1 0 0 0 0 1 1 1 1 0 1 1 1 1
0 1 1 0 0 1 1 0 0 1 1 0 1 0 0 0 0 0 1 0 0 0 0 1 1 1 1 0 1 1 1 1 0 0 1 0 1 1 0 1 0 1 0 0 1 1 0 0 1 0 0 1 0 0 1 1 0 0 1 1 0 0 1 1
0 0 1 0 1 1 0 1 0 1 0 0 1 1 0 0 1 0 0 1 0 0 1 1 0 0 1 1 0 0 1 1 1 0 1 0 1 1 0 1 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1
1 0 1 0 1 1 0 1 0 0 1 0 0 1 1 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 0 1 1 1 0 1 1 0 1 1 1 0 0 1 1 0 1 1 0 0 0 0 0 1 1 0 1 0 1 0 1 1
0 1 1 1 0 1 1 0 1 1 1 0 0 1 1 0 1 1 0 0 0 0 0 1 1 0 1 0 1 0 1 1 0 0 1 1 1 0 1 1 1 1 0 1 0 0 0 1 0 1 0 1 0 0 0 0 1 1 0 0 0 1 0 0
0 0 1 1 1 0 1 1 1 1 0 1 0 0 0 1 0 1 0 1 0 0 0 0 1 1 0 0 0 1 0 0 1 0 0 0 0 1 1 1 1 1 0 1 0 1 1 0 0 1 0 1 1 1 0 0 1 1 1 1 1 1 0 1
1 0 0 0 0 1 1 1 1 1 0 1 0 1 1 0 0 1 0 1 1 1 0 0 1 1 1 1 1 1 0 1 1 0 1 1 1 1 0 0 0 1 1 0 0 0 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 1 0 1
1 0 1 1 1 1 0 0 0 1 1 0 0 0 0 1 0 0 0 1 0 1 0 0 0 1 0 1 0 1 0 1 1 1 1 1 1 0 1 1 1 1 1 0 1 0 0 1 0 1 1 1 0 0 1 0 1 1 1 0 0 0 0 1
1 1 1 1 1 0 1 1 1 1 1 0 1 0 0 1 0 1 1 1 0 0 1 0 1 1 1 0 0 0 0 1 0 1 1 1 1 1 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 1 0 0 0 1 1 0 0 0
0 1 1 1 1 1 0 0 0 1 0 0 0 0 1 1 1 0 0 0 0 1 0 1 0 0 0 1 1 0 0 0 0 0 0 0 0 1 1 1 0 0 0 1 0 0 1 0 1 1 0 0 1 1 0 0 1 0 0 0 1 0 1 0
0 0 0 0 0 1 1 1 0 0 0 1 0 0 1 0 1 1 0 0 1 1 0 0 1 0 0 0 1 0 1 0 1 0 0 1 1 1 0 1 0 1 1 0 1 0 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 1
1 0 0 1 1 1 0 1 0 1 1 0 1 0 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 0 0 1 0 0 1 1 1 1 0 0 0 0 1 0 1 1 1 1 0 0 0 0 1 0 0 1 0 0 1 0 1 0 0 0
0 0 1 1 1 1 0 0 0 0 1 0 1 1 1 1 0 0 0 0 1 0 0 1 0 0 1 0 1 0 0 0 0 1 1 1 0 1 1 1 1 1 0 0 1 1 0 1 1 1 0 0 0 1 0 0 1 1 1 1 1 0 0 1

改变密钥后各轮得到的密文bit

1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 0 0 1 0 0 0 1 1 0 1 1 1 1 0 1 0 1 1 0 1 0 0 0 1 0 0 0 0 1
1 1 1 0 0 1 0 0 0 1 1 0 1 1 1 1 0 1 0 1 1 0 1 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 0 1 0 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 1 0 1 0 0 1
0 0 0 1 0 0 0 0 0 1 0 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 1 0 1 0 0 1 0 1 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1 1 0 0 1 1 0 1 0 1 1
0 1 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1 1 0 0 1 1 0 1 0 1 1 0 1 0 1 1 0 1 1 0 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 0 1 1 0 0 0 1 1
0 1 0 1 1 0 1 1 0 1 0 0 0 0 0 1 0 0 1 1 0 1 1 1 0 1 1 0 0 0 1 1 1 0 1 1 1 0 0 0 0 1 1 1 1 1 0 1 0 1 1 0 0 0 0 0 0 0 1 0 0 1 0 1
1 0 1 1 1 0 0 0 0 1 1 1 1 1 0 1 0 1 1 0 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 1 1 0 1 1 0 0 0 0 1 1 1 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 0 1
0 1 1 1 1 0 1 1 0 0 0 0 1 1 1 0 1 0 0 1 1 1 1 1 1 1 1 1 1 1 0 1 0 0 0 0 1 0 1 1 1 0 0 0 1 1 1 0 0 0 1 0 0 0 0 0 0 1 0 0 1 0 1 1
0 0 0 0 1 0 1 1 1 0 0 0 1 1 1 0 0 0 1 0 0 0 0 0 0 1 0 0 1 0 1 1 1 0 1 0 1 1 0 0 0 1 0 0 0 0 0 1 0 1 0 1 0 0 1 1 1 1 1 1 0 0 0 0
1 0 1 0 1 1 0 0 0 1 0 0 0 0 0 1 0 1 0 1 0 0 1 1 1 1 1 1 0 0 0 0 0 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 0 0 1 1 0 0 1 0 1
0 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 1 1 0 1 1 0 0 1 1 0 0 1 0 1 0 0 1 1 0 1 1 1 0 1 1 1 0 1 0 0 1 1 1 1 0 1 0 0 0 1 1 1 1 0 0 1
0 0 1 1 0 1 1 1 0 1 1 1 0 1 0 0 1 1 1 1 0 1 0 0 0 1 1 1 1 0 0 1 0 1 1 0 1 0 1 0 0 1 0 0 1 0 1 1 1 0 0 1 0 1 0 0 0 1 1 0 1 1 0 1
0 1 1 0 1 0 1 0 0 1 0 0 1 0 1 1 1 0 0 1 0 1 0 0 0 1 1 0 1 1 0 1 1 1 1 1 0 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 0 1 0 0 0 1 1 1 0 0 0 1
1 1 1 1 0 0 1 0 1 0 1 1 0 1 0 1 0 1 0 0 0 1 0 0 0 1 1 1 0 0 0 1 0 0 1 0 1 0 1 0 0 1 0 1 1 0 1 1 1 0 1 1 0 1 1 0 1 0 1 0 0 0 1 1
0 0 1 0 1 0 1 0 0 1 0 1 1 0 1 1 1 0 1 1 0 1 1 0 1 0 1 0 0 0 1 1 1 0 1 1 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0 1 0 1 1 0 1 1 0 0 0 0 0
1 0 1 1 0 1 0 0 0 0 0 1 0 0 0 1 0 0 0 0 1 0 1 1 0 1 1 0 0 0 0 0 1 0 1 1 0 1 1 0 0 0 1 1 0 0 1 0 1 0 1 0 0 0 1 1 1 0 0 0 0 0 0 0
1 0 1 1 0 1 1 0 0 0 1 1 0 0 1 0 1 0 1 0 0 0 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 0 1 0 0 0 0 0 1 1 0 1 0 1 1 1 1 1 1 1 0 1 0 1 1 0 0 1

原明文加密各轮产生的密文bit

0 1 0 1 0 1 0 1 0 1 1 1 1 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 0 0 1 0 1 0 1 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 1
1 1 0 0 1 0 1 0 1 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 1 1 0 0 1 0 1 0 0 0 1 1 1 0 1 1 0 0 0 0 0 0 0 1 0 1 1 1 0 1 0 1 1
1 0 0 1 0 1 0 0 0 1 1 1 0 1 1 0 0 0 0 0 0 0 1 0 1 1 1 0 1 0 1 1 1 0 1 1 0 0 0 1 0 0 0 1 0 0 1 1 1 1 1 0 1 1 1 0 0 0 0 1 0 1 0 0
1 0 1 1 0 0 0 1 0 0 0 1 0 0 1 1 1 1 1 0 1 1 1 0 0 0 0 1 0 1 0 0 0 0 0 1 0 0 1 1 1 0 1 1 0 1 0 1 1 1 0 0 1 1 1 0 0 0 1 0 0 0 1 1
0 0 0 1 0 0 1 1 1 0 1 1 0 1 0 1 1 1 0 0 1 1 1 0 0 0 1 0 0 0 1 1 0 1 0 1 0 1 1 0 0 1 0 0 1 1 0 1 1 1 0 1 0 0 1 0 1 1 0 0 0 0 1 0
0 1 0 1 0 1 1 0 0 1 0 0 1 1 0 1 1 1 0 1 0 0 1 0 1 1 0 0 0 0 1 0 1 0 1 0 1 0 1 1 1 0 1 0 1 0 1 1 1 1 0 0 1 0 1 1 0 1 1 0 0 1 0 0
1 0 1 0 1 0 1 1 1 0 1 0 1 0 1 1 1 1 0 0 1 0 1 1 0 1 1 0 0 1 0 0 0 1 1 0 1 1 0 0 0 0 0 1 0 1 0 1 1 1 1 0 0 0 1 0 0 0 0 0 0 0 1 1
0 1 1 0 1 1 0 0 0 0 0 1 0 1 0 1 1 1 1 0 0 0 1 0 0 0 0 0 0 0 1 1 1 1 0 0 0 1 1 0 1 0 1 1 0 1 1 1 0 1 1 1 1 1 0 0 0 0 1 1 0 0 0 1
1 1 0 0 0 1 1 0 1 0 1 1 0 1 1 1 0 1 1 1 1 1 0 0 0 0 1 1 0 0 0 1 0 0 0 0 1 0 1 1 0 1 1 1 1 1 1 0 0 1 1 1 1 1 1 0 0 0 1 1 0 1 1 0
0 0 0 0 1 0 1 1 0 1 1 1 1 1 1 0 0 1 1 1 1 1 1 0 0 0 1 1 0 1 1 0 0 1 1 1 1 1 0 1 0 1 1 0 0 0 0 0 0 0 1 0 1 0 1 1 1 1 0 0 0 0 0 1
0 1 1 1 1 1 0 1 0 1 1 0 0 0 0 0 0 0 1 0 1 0 1 1 1 1 0 0 0 0 0 1 0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 0 1 1 0 0 1 1 1 0 0 0 1 0 1 0 0 0
0 1 1 1 1 0 0 0 1 0 1 0 1 1 0 0 1 1 0 0 1 1 1 0 0 0 1 0 1 0 0 0 1 1 0 0 0 1 1 1 0 1 1 1 1 0 0 1 1 1 1 1 1 0 1 1 0 1 1 0 0 0 0 1
1 1 0 0 0 1 1 1 0 1 1 1 1 0 0 1 1 1 1 1 1 0 1 1 0 1 1 0 0 0 0 1 0 1 1 0 0 1 0 1 0 0 0 1 1 0 0 0 0 1 1 1 1 1 0 1 1 1 0 1 1 0 1 0
0 1 1 0 0 1 0 1 0 0 0 1 1 0 0 0 0 1 1 1 1 1 0 1 1 1 0 1 1 0 1 0 0 0 0 0 1 0 1 1 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 1 0 0 1
0 0 0 0 1 0 1 1 1 1 0 1 1 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 1 0 0 1 1 0 1 0 1 1 1 0 0 1 0 0 1 0 1 1 0 1 1 0 0 0 1 0 0 0 1 0 1 1 1 1
1 0 1 0 1 1 1 0 0 1 0 0 1 0 1 1 0 1 1 0 0 0 1 0 0 0 1 0 1 1 1 1 0 0 0 1 0 1 1 1 0 0 0 0 0 0 1 0 1 1 0 0 0 0 1 1 0 0 1 1 0 1 0 0

改变明文后各轮得到的密文bit

0 1 0 1 0 1 0 1 0 1 1 1 1 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 0 0 1 0 0 0 1 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 1
1 1 0 0 1 0 0 0 1 0 1 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 1 1 1 1 0 1 0 1 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 1 0 1 1 1 1 1 0 1 1
1 1 0 1 0 1 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 1 0 1 1 1 1 1 0 1 1 1 0 1 1 0 0 0 1 0 1 0 0 0 0 0 1 1 1 1 0 0 0 0 1 0 1 1 1 0 0 1 1
1 0 1 1 0 0 0 1 0 1 0 0 0 0 0 1 1 1 1 0 0 0 0 1 0 1 1 1 0 0 1 1 1 1 1 0 1 1 0 0 1 0 1 0 1 1 1 1 1 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1
1 1 1 0 1 1 0 0 1 0 1 0 1 1 1 1 1 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 0 0 0 1 0 0 1 1 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 0 0 1 0 0 0 0 0 0
0 0 0 1 0 0 1 1 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 1 0 1 1 0 1 1 0 1 0 1 0 0 0 0 0 0 0 1 0 1
0 0 1 1 0 1 1 0 0 0 0 1 0 1 1 0 1 1 0 1 0 1 0 0 0 0 0 0 0 1 0 1 1 0 1 0 1 0 0 1 0 0 1 1 1 0 1 0 0 1 0 1 1 0 1 1 0 1 1 0 1 0 1 0
1 0 1 0 1 0 0 1 0 0 1 1 1 0 1 0 0 1 0 1 1 0 1 1 0 1 1 0 1 0 1 0 0 1 0 1 1 1 1 1 1 0 1 0 0 0 1 1 0 0 1 1 1 1 1 1 1 1 0 0 1 1 0 0
0 1 0 1 1 1 1 1 1 0 1 0 0 0 1 1 0 0 1 1 1 1 1 1 1 1 0 0 1 1 0 0 1 1 1 0 0 0 0 0 0 1 0 0 0 1 1 0 0 1 0 0 0 0 1 1 0 1 0 1 0 1 1 0
1 1 1 0 0 0 0 0 0 1 0 0 0 1 1 0 0 1 0 0 0 0 1 1 0 1 0 1 0 1 1 0 1 0 0 0 0 1 1 0 1 1 1 1 0 0 1 1 1 0 0 1 1 1 1 0 0 0 0 1 1 1 0 1
1 0 0 0 0 1 1 0 1 1 1 1 0 0 1 1 1 0 0 1 1 1 1 0 0 0 0 1 1 1 0 1 0 1 0 0 0 0 0 0 0 1 1 1 0 0 1 1 1 0 1 1 1 1 1 0 0 0 1 1 1 0 1 1
0 1 0 0 0 0 0 0 0 1 1 1 0 0 1 1 1 0 1 1 1 1 1 0 0 0 1 1 1 0 1 1 1 1 0 1 0 0 0 1 1 1 0 0 1 1 0 1 0 1 1 1 0 0 0 1 1 0 0 0 1 1 1 0
1 1 0 1 0 0 0 1 1 1 0 0 1 1 0 1 0 1 1 1 0 0 0 1 1 0 0 0 1 1 1 0 0 1 0 0 1 1 0 1 0 1 1 0 1 0 0 0 0 1 0 1 1 1 1 1 1 0 0 0 1 0 0 1
0 1 0 0 1 1 0 1 0 1 1 0 1 0 0 0 0 1 0 1 1 1 1 1 1 0 0 0 1 0 0 1 1 0 0 0 0 1 0 1 1 0 1 0 0 0 1 1 0 1 1 0 1 1 1 1 0 1 0 0 1 1 1 0
1 0 0 0 0 1 0 1 1 0 1 0 0 0 1 1 0 1 1 0 1 1 1 1 0 1 0 0 1 1 1 0 1 1 0 0 1 1 0 1 0 0 1 1 1 1 1 0 1 1 0 1 0 1 1 1 0 0 1 1 0 1 1 0
1 1 0 0 1 1 0 1 0 0 1 1 1 1 1 0 1 1 0 1 0 1 1 1 0 0 1 1 0 1 1 0 1 1 0 1 0 1 0 0 0 1 0 0 1 1 0 0 0 0 1 1 1 1 1 1 1 0 1 1 0 0 0 1

附录B

#ifndef _TABLES_H_
#define _TABLES_H_  

const char IP_Table[64]={             
    58,50,42,34,26,18,10, 2,60,52,44,36,28,20,12, 4,
    62,54,46,38,30,22,14, 6,64,56,48,40,32,24,16, 8,
    57,49,41,33,25,17, 9, 1,59,51,43,35,27,19,11, 3,
    61,53,45,37,29,21,13, 5,63,55,47,39,31,23,15, 7 
};

const char IPR_Table[64]={              
    40, 8,48,16,56,24,64,32,39, 7,47,15,55,23,63,31,
    38, 6,46,14,54,22,62,30,37, 5,45,13,53,21,61,29,
    36, 4,44,12,52,20,60,28,35, 3,43,11,51,19,59,27,
    34, 2,42,10,50,18,58,26,33, 1,41, 9,49,17,57,25 
};

static char E_Table[48]={
    32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9,
     8, 9,10,11,12,13,12,13,14,15,16,17,
    16,17,18,19,20,21,20,21,22,23,24,25,
    24,25,26,27,28,29,28,29,30,31,32, 1
};

static char S_Box[8][4][16]={
    //S1
    14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
     0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
     4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
    15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,
    //S2
    15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
     3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
     0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
    13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,
    //S3
    10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
    13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
    13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
     1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,
    //S4
     7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
    13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
    10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
     3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,
    //S5
     2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
    14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
     4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
    11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,
    //S6
    12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
    10,15, 4, 2, 7,12, 0, 5, 6, 1,13,14, 0,11, 3, 8,
     9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
     4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,
    //S7
     4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
    13, 0,11, 7, 4, 0, 1,10,14, 3, 5,12, 2,15, 8, 6,
     1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
     6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,
    //S8
    13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
     1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
     7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
     2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11
};

static char P_Table[32]={
    16, 7,20,21,29,12,28,17, 1,15,23,26, 5,18,31,10,
     2, 8,24,14,32,27, 3, 9,19,13,30, 6,22,11, 4,25
};

static bool SubKey[16][48]={0};

#endif

//
//  main.cpp
//  DES
//
//  Created by tinoryj on 2017/3/26.
//  Copyright © 2017年 tinoryj. All rights reserved.
//

#include <stdlib.h>
#include <stdio.h>
#include "tables.h"
#include <iostream>
using namespace std;

void BitsCopy(bool *DatOut,bool *DatIn,int Len);  // 数组复制
void ByteToBit(bool *DatOut,char *DatIn,int Num); // 字节到位
void BitToByte(char *DatOut,bool *DatIn,int Num); // 位到字节
void BitToHex(char *DatOut,bool *DatIn,int Num);  // 二进制到十六进制 64位 to 4*16字符
void HexToBit(bool *DatOut,char *DatIn,int Num);  // 十六进制到二进制
void TablePermute(bool *DatOut,bool *DatIn,const char *Table,int Num); // 位表置换函数
void LoopMove(bool *DatIn,int Len,int Num);     // 循环左移 Len长度 Num移动位数
void Xor(bool *DatA,bool *DatB,int Num);         // 异或函数
void S_Change(bool DatOut[32],bool DatIn[48]);   // S盒变换
void F_Change(bool DatIn[32],bool DatKi[48]);    // F函数
void SetKey(char KeyIn[24]);                         // 设置密钥
void PlayDes(char MesOut[8],char MesIn[8]);       // 执行DES加密
void KickDes(char MesOut[8],char MesIn[8]);             // 执行DES解密

int main(){
    char MesHex[16];         // 16个字符数组用于存放 64位16进制的密文
    char MyKey[25];           // 初始密钥 8字节*8
    char MyMessage[8];       // 初始明文
    cout<<"Input Message:64bit:"<<endl;
    cin>>MyMessage;            // 明文
    cout<<"Input Secret Key:192bit"<<endl;
    cin>>MyKey;                  // 密钥
    int len = 0;
    while(MyKey[len]!='\0')
        len++;
    while(len!=24){
        cout<<"Input Correct Secret Key!"<<endl;
        cin>>MyKey;
        len = 0;
        while(MyKey[len]!='\0')
            len++;
    }
    SetKey(MyKey);               // 设置密钥 得到子密钥Ki
    PlayDes(MesHex,MyMessage);   // 执行DES加密
    cout<<"Encrypting:"<<endl;  // 信息已加密
    for(int i = 0; i < 16; i++)
        cout<<MesHex[i];
    cout<<endl;
    KickDes(MyMessage,MesHex);                     // 解密输出到MyMessage
    cout<<"Deciphering:"<<endl;
    for(int i = 0; i < 8; i++)
        cout<<MyMessage[i];
    cout<<endl;
}
//位移动
void BitsCopy(bool *DatOut,bool *DatIn,int Len){
    for(int i = 0; i < Len; i++)
        DatOut[i] = DatIn[i];
}
//字节转换成位
void ByteToBit(bool *DatOut,char *DatIn,int Num){
    for(int i = 0; i < Num; i++)
        DatOut[i] = (DatIn[i / 8] >> (i % 8)) & 0x01;
}
//位转换成字节
void BitToByte(char *DatOut,bool *DatIn,int Num){
    for(int i = 0; i < (Num / 8); i++)
        DatOut[i] = 0;
    for(int i = 0; i < Num; i++)
        DatOut[i / 8] |= DatIn[i] << (i % 8);
}
//二进制密文转换为十六进制
void BitToHex(char *DatOut,bool *DatIn,int Num){
    for(int i = 0; i < Num / 4; i++)
        DatOut[i] = 0;
    for(int i = 0; i < Num / 4; i++){
        DatOut[i] = DatIn[i * 4] + (DatIn[i * 4 + 1] << 1) + (DatIn[i * 4 + 2] << 2) + (DatIn[i * 4 + 3] << 3);
        if((DatOut[i] % 16) > 9)
            DatOut[i] = DatOut[i] % 16 + '7';       //  余数大于9时处理 10-15 to A-F
        else
            DatOut[i] = DatOut[i] % 16 + '0';
    }
}
//十六进制字符转二进制
void HexToBit(bool *DatOut,char *DatIn,int Num){
    for(int i = 0; i < Num; i++){
        if((DatIn[i / 4]) > '9')         //  大于9
            DatOut[i] = ((DatIn[i / 4] - '7') >> (i % 4)) & 0x01;
        else
            DatOut[i] = ((DatIn[i / 4] - '0') >> (i % 4)) & 0x01;
    }
}
//表置换函数
void TablePermute(bool *DatOut,bool *DatIn,const char *Table,int Num){
    static bool Temp[256]={0};
    for(int i = 0; i < Num; i++)                // Num为置换的长度
        Temp[i] = DatIn[Table[i] - 1];  // 原来的数据按对应的表上的位置排列
    BitsCopy(DatOut,Temp,Num);       // 把缓存Temp的值输出
}
// 子密钥的移位
void LoopMove(bool *DatIn,int Len,int Num){
    
    static bool Temp[256]={0};
    BitsCopy(Temp,DatIn,Num);       // 将数据最左边的Num位(被移出去的)存入Temp
    BitsCopy(DatIn,DatIn+Num,Len-Num); // 将数据左边开始的第Num移入原来的空间
    BitsCopy(DatIn+Len-Num,Temp,Num);  // 将缓存中移出去的数据加到最右边
}
// 按位异或
void Xor(bool *DatA,bool *DatB,int Num){
    for(int i = 0; i < Num; i++)
        DatA[i] = DatA[i] ^ DatB[i];
}
// S盒
void S_Change(bool DatOut[32],bool DatIn[48]){
    for(int i = 0,Y = 0,X = 0; i < 8; i++,DatIn += 6,DatOut += 4){   // 每执行一次,输入数据偏移6位,输出数据偏移4位
        Y = (DatIn[0] << 1) + DatIn[5];                          //af代表第几行
        X = (DatIn[1] << 3) + (DatIn[2] << 2) + (DatIn[3] << 1) + DatIn[4]; // bcde代表第几列
        ByteToBit(DatOut,&S_Box[i][Y][X],4);      // 把找到的点数据换为二进制
    }
}
// F函数
void F_Change(bool DatIn[32],bool DatKi[48]){
    bool MiR[48] = {0};             // 输入32位通过E选位变为48位
    TablePermute(MiR,DatIn,E_Table,48);
    Xor(MiR,DatKi,48);                   // 和子密钥异或
    S_Change(DatIn,MiR);                 // S盒变换
    TablePermute(DatIn,DatIn,P_Table,32);   // P置换后输出
}

void SetKey(char KeyIn[8]){      // 设置密钥 获取子密钥Ki
    static bool KeyBit[192]={0};                // 密钥二进制存储空间
    static bool *KiL =&KeyBit[0],*KiR =&KeyBit[64],*KiB =&KeyBit[128];
    ByteToBit(KeyBit,KeyIn,192);                    // 把密钥转为二进制存入KeyBit
    for(int i = 0; i < 16; i++){
        LoopMove(KiL,64,4);
        LoopMove(KiR,64,4);
        LoopMove(KiB,64,4);
        bool temp[64] = {0};
        for(int j = 0; j < 64; j++){
            temp[j] = KeyBit[i] ^ KeyBit[i + 64];
            temp[j] = temp[j] ^ KeyBit[i + 128];
        }
        bool tep[48] = {0};
        for(int j = 0; j < 16; j++){
            tep[j] = (temp[j]^temp[j+16])^(temp[j+32]^temp[j+48]);
            tep[j+16] = tep[j];
            tep[j+32] = tep[j];
        }
        for(int j = 0; j < 16; j++)
            SubKey[i][j] = tep[j];
    }
}
// 执行DES加密
void PlayDes(char MesOut[8],char MesIn[8]){
    static bool MesBit[64]={0};        // 明文二进制存储空间 64位
    static bool Temp[32]={0};
    static bool *MiL=&MesBit[0],*MiR=&MesBit[32]; // 前32位 后32位
    ByteToBit(MesBit,MesIn,64);                 // 把明文换成二进制存入MesBit
    TablePermute(MesBit,MesBit,IP_Table,64);    // IP置换
    for(int i = 0; i < 16; i++){
        BitsCopy(Temp,MiR,32);            // 临时存储
        F_Change(MiR,SubKey[i]);          // F函数变换
        Xor(MiR,MiL,32);                  // 得到Ri
        BitsCopy(MiL,Temp,32);            // 得到Li
    }
    TablePermute(MesBit,MesBit,IPR_Table,64);
    BitToHex(MesOut,MesBit,64);
}
// 执行DES解密
void KickDes(char MesOut[8],char MesIn[8]){
    static bool MesBit[64]={0};        // 密文二进制存储空间 64位
    static bool Temp[32]={0};
    static bool *MiL=&MesBit[0],*MiR=&MesBit[32]; // 前32位 后32位
    HexToBit(MesBit,MesIn,64);                 // 把密文换成二进制存入MesBit
    TablePermute(MesBit,MesBit,IP_Table,64);    // IP置换
    for(int i = 15; i >= 0; i--){
        BitsCopy(Temp,MiL,32);
        F_Change(MiL,SubKey[i]);
        Xor(MiL,MiR,32);
        BitsCopy(MiR,Temp,32);
    }
    TablePermute(MesBit,MesBit,IPR_Table,64);
    BitToByte(MesOut,MesBit,64);
}