zuc算法代码详解_ZUC算法了解

ZUC算法是一个面向字的流加密算法。它使用一个128位的初始密钥 key 和一个128位的初始向量 iv 来作为输入，可以输出若干个32位字的密钥流，也就就是说每32位字在这里称为一个密钥字。这样产生的密钥流可以用于加密和解密。以下内容参考自 ZUC 标准文档

1. 简介

在ZUC算法中，有两个执行阶段，分别是初始化阶段和工作阶段。在初始化阶段中， key 和 iv 被初始化完成。在工作阶段中，每个时钟脉冲都能产生一个32位字的密钥流输出。

2. 符号与约定

2.1 数制表示

下文使用十进制、十六进制、二进制进行表示例如：

2.2 比特序

在下文中，所有数据变量的左侧是高有效位(字节)，右侧为低有效位(字节)。例如：

，那么它的最高有效位是

(最左侧的)，最低有效位是

(最右侧的)。

2.3 符号约定

3. 算法描述

3.1 算法结构

如下图所示，ZUC 算法有三层结构，第一层是一个16级线性反馈移位寄存器(LSFR，linear feedback shift register)。中间是一个比特重组层(BR，bit-reorganization)。最下层是一个非线性函数

。

3.2 线性反馈移位寄存器(LSFR)

线性反馈移位寄存器(LSFR)有16个31比特的单元(

)，它的运行有两种模式：初始化模式和工作模式。

在初始化阶段，LFSR读入一个31位的输入字 u ，它通过从非线性函数 F 的32位输出 W 中删除最右边的位来获得，例如：u = W >> 1，具体的工作方式如下：

在工作阶段，LSFR不会接收任何输入，并且按照下面方式工作：

**Tips：**在 LFSRWithInitializationMode 函数中的 Step.1 ，可以使用如下操作来实现：

当然，可以类比着对 LFSRWithWordMode() 中的 Step.1 进行实现。

3.3 比特重组(BR)

中间层是一个比特重组算法。它从LFSR中提取出来 128 比特，然后组成 4 个 32 位的字，前三个字是提供给底层非线性 F 函数使用的，最后一个字用来生成密钥流。重组后的

，如下所示：

注意：这里的

是 31 比特的整数类型，所以

表示的是

的 30...15 位而不是 31...16 位。

3.4 非线性函数 F

非线性函数 F 有两个 32 比特的记忆单元

和

，输入为 3 个 32 比特的字：

，输出一个 32 比特的字 W。具体描述如下：

这里的 S 是一个 32*32 大小的 S-Box，而

，

是线性变换。

3.4.1 S-Box

32*32大小的 S-Box(S)，其实是四个大小为 8*8的 S-boxes 并置而成，例如：

，这里的

。那么

和

具体内容如下：

unsigned char S0[256] = {

0x3e,0x72,0x5b,0x47,0xca,0xe0,0x00,0x33,0x04,0xd1,0x54,0x98,0x09,0xb9,0x6d,0xcb,

0x7b,0x1b,0xf9,0x32,0xaf,0x9d,0x6a,0xa5,0xb8,0x2d,0xfc,0x1d,0x08,0x53,0x03,0x90,

0x4d,0x4e,0x84,0x99,0xe4,0xce,0xd9,0x91,0xdd,0xb6,0x85,0x48,0x8b,0x29,0x6e,0xac,

0xcd,0xc1,0xf8,0x1e,0x73,0x43,0x69,0xc6,0xb5,0xbd,0xfd,0x39,0x63,0x20,0xd4,0x38,

0x76,0x7d,0xb2,0xa7,0xcf,0xed,0x57,0xc5,0xf3,0x2c,0xbb,0x14,0x21,0x06,0x55,0x9b,

0xe3,0xef,0x5e,0x31,0x4f,0x7f,0x5a,0xa4,0x0d,0x82,0x51,0x49,0x5f,0xba,0x58,0x1c,

0x4a,0x16,0xd5,0x17,0xa8,0x92,0x24,0x1f,0x8c,0xff,0xd8,0xae,0x2e,0x01,0xd3,0xad,

0x3b,0x4b,0xda,0x46,0xeb,0xc9,0xde,0x9a,0x8f,0x87,0xd7,0x3a,0x80,0x6f,0x2f,0xc8,

0xb1,0xb4,0x37,0xf7,0x0a,0x22,0x13,0x28,0x7c,0xcc,0x3c,0x89,0xc7,0xc3,0x96,0x56,

0x07,0xbf,0x7e,0xf0,0x0b,0x2b,0x97,0x52,0x35,0x41,0x79,0x61,0xa6,0x4c,0x10,0xfe,

0xbc,0x26,0x95,0x88,0x8a,0xb0,0xa3,0xfb,0xc0,0x18,0x94,0xf2,0xe1,0xe5,0xe9,0x5d,

0xd0,0xdc,0x11,0x66,0x64,0x5c,0xec,0x59,0x42,0x75,0x12,0xf5,0x74,0x9c,0xaa,0x23,

0x0e,0x86,0xab,0xbe,0x2a,0x02,0xe7,0x67,0xe6,0x44,0xa2,0x6c,0xc2,0x93,0x9f,0xf1,

0xf6,0xfa,0x36,0xd2,0x50,0x68,0x9e,0x62,0x71,0x15,0x3d,0xd6,0x40,0xc4,0xe2,0x0f,

0x8e,0x83,0x77,0x6b,0x25,0x05,0x3f,0x0c,0x30,0xea,0x70,0xb7,0xa1,0xe8,0xa9,0x65,

0x8d,0x27,0x1a,0xdb,0x81,0xb3,0xa0,0xf4,0x45,0x7a,0x19,0xdf,0xee,0x78,0x34,0x60

};

unsigned char S1[256] = {

0x55,0xc2,0x63,0x71,0x3b,0xc8,0x47,0x86,0x9f,0x3c,0xda,0x5b,0x29,0xaa,0xfd,0x77,

0x8c,0xc5,0x94,0x0c,0xa6,0x1a,0x13,0x00,0xe3,0xa8,0x16,0x72,0x40,0xf9,0xf8,0x42,

0x44,0x26,0x68,0x96,0x81,0xd9,0x45,0x3e,0x10,0x76,0xc6,0xa7,0x8b,0x39,0x43,0xe1,

0x3a,0xb5,0x56,0x2a,0xc0,0x6d,0xb3,0x05,0x22,0x66,0xbf,0xdc,0x0b,0xfa,0x62,0x48,

0xdd,0x20,0x11,0x06,0x36,0xc9,0xc1,0xcf,0xf6,0x27,0x52,0xbb,0x69,0xf5,0xd4,0x87,

0x7f,0x84,0x4c,0xd2,0x9c,0x57,0xa4,0xbc,0x4f,0x9a,0xdf,0xfe,0xd6,0x8d,0x7a,0xeb,

0x2b,0x53,0xd8,0x5c,0xa1,0x14,0x17,0xfb,0x23,0xd5,0x7d,0x30,0x67,0x73,0x08,0x09,

0xee,0xb7,0x70,0x3f,0x61,0xb2,0x19,0x8e,0x4e,0xe5,0x4b,0x93,0x8f,0x5d,0xdb,0xa9,

0xad,0xf1,0xae,0x2e,0xcb,0x0d,0xfc,0xf4,0x2d,0x46,0x6e,0x1d,0x97,0xe8,0xd1,0xe9,

0x4d,0x37,0xa5,0x75,0x5e,0x83,0x9e,0xab,0x82,0x9d,0xb9,0x1c,0xe0,0xcd,0x49,0x89,

0x01,0xb6,0xbd,0x58,0x24,0xa2,0x5f,0x38,0x78,0x99,0x15,0x90,0x50,0xb8,0x95,0xe4,

0xd0,0x91,0xc7,0xce,0xed,0x0f,0xb4,0x6f,0xa0,0xcc,0xf0,0x02,0x4a,0x79,0xc3,0xde,

0xa3,0xef,0xea,0x51,0xe6,0x6b,0x18,0xec,0x1b,0x2c,0x80,0xf7,0x74,0xe7,0xff,0x21,

0x5a,0x6a,0x54,0x1e,0x41,0x31,0x92,0x35,0xc4,0x33,0x07,0x0a,0xba,0x7e,0x0e,0x34,

0x88,0xb1,0x98,0x7c,0xf3,0x3d,0x60,0x6c,0x7b,0xca,0xd3,0x1f,0x32,0x65,0x04,0x28,

0x64,0xbe,0x85,0x9b,0x2f,0x59,0x8a,0xd7,0xb0,0x25,0xac,0xaf,0x12,0x03,0xe2,0xf2

};

3.4.2 线性变换

对于

和

线性变换而言，都是将 32 位的字转换成另一个 32 位的字，具体转换如下：

3.5 密钥装入

密钥装入过程，将会把初始密钥 k(128 bits) 和 iv(128 bits) 扩展成 16 个 31 位整数，作为 LFSR 的初始状态。

装载过程如下：

和：

这里的

和

均为 8 位的字节，然后构造 D， D 为 240 比特的常量，可以按照如下方式分成 16 个 15 位的子串：

那么

。

对于

，有：

。

3.6 ZUC算法执行过程

两个阶段：初始化阶段和工作阶段。

3.6.1 初始化阶段

在初始化阶段，算法将 128 比特的 key 和 iv 载入并处理，然后装入到 LFSR 中，与此同时，设置 32 比特的记忆单元

和

(初始化为 0)。然后执行下面的操作 31 次。

3.6.2 工作阶段

初始化完成后，算法立刻进入工作阶段。在该阶段，算法执行下面操作一次，并且丢掉 F 的输出 W：

然后算法再进入密钥流产生阶段，在每次迭代时，下面操作执行一次，并输出一次 32 比特的字 Z 作为输出。

附录

A. C语言实现

#include "ZUC.h"

/* ——————————————————————- */

typedef unsigned char u8;

typedef unsigned int u32;

/* ——————————————————————- */

/* the state registers of LFSR */

u32 LFSR_S0;

u32 LFSR_S1;

u32 LFSR_S2;

u32 LFSR_S3;

u32 LFSR_S4;

u32 LFSR_S5;

u32 LFSR_S6;

u32 LFSR_S7;

u32 LFSR_S8;

u32 LFSR_S9;

u32 LFSR_S10;

u32 LFSR_S11;

u32 LFSR_S12;

u32 LFSR_S13;

u32 LFSR_S14;

u32 LFSR_S15;

/* the registers of F */

u32 F_R1;

u32 F_R2;

/* the outputs of BitReorganization */

u32 BRC_X0;

u32 BRC_X1;

u32 BRC_X2;

u32 BRC_X3;

/* the s-boxes */

u8 S0[256] = {

0x3e, 0x72, 0x5b, 0x47, 0xca, 0xe0, 0x00, 0x33, 0x04, 0xd1, 0x54, 0x98, 0x09, 0xb9, 0x6d, 0xcb,

0x7b, 0x1b, 0xf9, 0x32, 0xaf, 0x9d, 0x6a, 0xa5, 0xb8, 0x2d, 0xfc, 0x1d, 0x08, 0x53, 0x03, 0x90,

0x4d, 0x4e, 0x84, 0x99, 0xe4, 0xce, 0xd9, 0x91, 0xdd, 0xb6, 0x85, 0x48, 0x8b, 0x29, 0x6e, 0xac,

0xcd, 0xc1, 0xf8, 0x1e, 0x73, 0x43, 0x69, 0xc6, 0xb5, 0xbd, 0xfd, 0x39, 0x63, 0x20, 0xd4, 0x38,

0x76, 0x7d, 0xb2, 0xa7, 0xcf, 0xed, 0x57, 0xc5, 0xf3, 0x2c, 0xbb, 0x14, 0x21, 0x06, 0x55, 0x9b,

0xe3, 0xef, 0x5e, 0x31, 0x4f, 0x7f, 0x5a, 0xa4, 0x0d, 0x82, 0x51, 0x49, 0x5f, 0xba, 0x58, 0x1c,

0x4a, 0x16, 0xd5, 0x17, 0xa8, 0x92, 0x24, 0x1f, 0x8c, 0xff, 0xd8, 0xae, 0x2e, 0x01, 0xd3, 0xad,

0x3b, 0x4b, 0xda, 0x46, 0xeb, 0xc9, 0xde, 0x9a, 0x8f, 0x87, 0xd7, 0x3a, 0x80, 0x6f, 0x2f, 0xc8,

0xb1, 0xb4, 0x37, 0xf7, 0x0a, 0x22, 0x13, 0x28, 0x7c, 0xcc, 0x3c, 0x89, 0xc7, 0xc3, 0x96, 0x56,

0x07, 0xbf, 0x7e, 0xf0, 0x0b, 0x2b, 0x97, 0x52, 0x35, 0x41, 0x79, 0x61, 0xa6, 0x4c, 0x10, 0xfe,

0xbc, 0x26, 0x95, 0x88, 0x8a, 0xb0, 0xa3, 0xfb, 0xc0, 0x18, 0x94, 0xf2, 0xe1, 0xe5, 0xe9, 0x5d,

0xd0, 0xdc, 0x11, 0x66, 0x64, 0x5c, 0xec, 0x59, 0x42, 0x75, 0x12, 0xf5, 0x74, 0x9c, 0xaa, 0x23,

0x0e, 0x86, 0xab, 0xbe, 0x2a, 0x02, 0xe7, 0x67, 0xe6, 0x44, 0xa2, 0x6c, 0xc2, 0x93, 0x9f, 0xf1,

0xf6, 0xfa, 0x36, 0xd2, 0x50, 0x68, 0x9e, 0x62, 0x71, 0x15, 0x3d, 0xd6, 0x40, 0xc4, 0xe2, 0x0f,

0x8e, 0x83, 0x77, 0x6b, 0x25, 0x05, 0x3f, 0x0c, 0x30, 0xea, 0x70, 0xb7, 0xa1, 0xe8, 0xa9, 0x65,

0x8d, 0x27, 0x1a, 0xdb, 0x81, 0xb3, 0xa0, 0xf4, 0x45, 0x7a, 0x19, 0xdf, 0xee, 0x78, 0x34, 0x60

};

u8 S1[256] = {

0x55, 0xc2, 0x63, 0x71, 0x3b, 0xc8, 0x47, 0x86, 0x9f, 0x3c, 0xda, 0x5b, 0x29, 0xaa, 0xfd, 0x77,

0x8c, 0xc5, 0x94, 0x0c, 0xa6, 0x1a, 0x13, 0x00, 0xe3, 0xa8, 0x16, 0x72, 0x40, 0xf9, 0xf8, 0x42,

0x44, 0x26, 0x68, 0x96, 0x81, 0xd9, 0x45, 0x3e, 0x10, 0x76, 0xc6, 0xa7, 0x8b, 0x39, 0x43, 0xe1,

0x3a, 0xb5, 0x56, 0x2a, 0xc0, 0x6d, 0xb3, 0x05, 0x22, 0x66, 0xbf, 0xdc, 0x0b, 0xfa, 0x62, 0x48,

0xdd, 0x20, 0x11, 0x06, 0x36, 0xc9, 0xc1, 0xcf, 0xf6, 0x27, 0x52, 0xbb, 0x69, 0xf5, 0xd4, 0x87,

0x7f, 0x84, 0x4c, 0xd2, 0x9c, 0x57, 0xa4, 0xbc, 0x4f, 0x9a, 0xdf, 0xfe, 0xd6, 0x8d, 0x7a, 0xeb,

0x2b, 0x53, 0xd8, 0x5c, 0xa1, 0x14, 0x17, 0xfb, 0x23, 0xd5, 0x7d, 0x30, 0x67, 0x73, 0x08, 0x09,

0xee, 0xb7, 0x70, 0x3f, 0x61, 0xb2, 0x19, 0x8e, 0x4e, 0xe5, 0x4b, 0x93, 0x8f, 0x5d, 0xdb, 0xa9,

0xad, 0xf1, 0xae, 0x2e, 0xcb, 0x0d, 0xfc, 0xf4, 0x2d, 0x46, 0x6e, 0x1d, 0x97, 0xe8, 0xd1, 0xe9,

0x4d, 0x37, 0xa5, 0x75, 0x5e, 0x83, 0x9e, 0xab, 0x82, 0x9d, 0xb9, 0x1c, 0xe0, 0xcd, 0x49, 0x89,

0x01, 0xb6, 0xbd, 0x58, 0x24, 0xa2, 0x5f, 0x38, 0x78, 0x99, 0x15, 0x90, 0x50, 0xb8, 0x95, 0xe4,

0xd0, 0x91, 0xc7, 0xce, 0xed, 0x0f, 0xb4, 0x6f, 0xa0, 0xcc, 0xf0, 0x02, 0x4a, 0x79, 0xc3, 0xde,

0xa3, 0xef, 0xea, 0x51, 0xe6, 0x6b, 0x18, 0xec, 0x1b, 0x2c, 0x80, 0xf7, 0x74, 0xe7, 0xff, 0x21,

0x5a, 0x6a, 0x54, 0x1e, 0x41, 0x31, 0x92, 0x35, 0xc4, 0x33, 0x07, 0x0a, 0xba, 0x7e, 0x0e, 0x34,

0x88, 0xb1, 0x98, 0x7c, 0xf3, 0x3d, 0x60, 0x6c, 0x7b, 0xca, 0xd3, 0x1f, 0x32, 0x65, 0x04, 0x28,

0x64, 0xbe, 0x85, 0x9b, 0x2f, 0x59, 0x8a, 0xd7, 0xb0, 0x25, 0xac, 0xaf, 0x12, 0x03, 0xe2, 0xf2

};

/* the constants D */

u32 EK_d[16] = {

0x44D7, 0x26BC, 0x626B, 0x135E, 0x5789, 0x35E2, 0x7135, 0x09AF,

0x4D78, 0x2F13, 0x6BC4, 0x1AF1, 0x5E26, 0x3C4D, 0x789A, 0x47AC

};

/* ——————————————————————- */

/* c = a + b mod (2^31 – 1) */

u32 AddM(u32 a, u32 b) {

u32 c = a + b;

return (c & 0x7FFFFFFF) + (c >> 31);

}

/* LFSR with initialization mode */

#define MulByPow2(x, k) ((((x) << k) | ((x) >> (31 - k))) & 0x7FFFFFFF)

void LFSRWithInitialisationMode(u32 u) {

u32 f, v;

f = LFSR_S0;

v = MulByPow2(LFSR_S0, 8);

f = AddM(f, v);

v = MulByPow2(LFSR_S4, 20);

f = AddM(f, v);

v = MulByPow2(LFSR_S10, 21);

f = AddM(f, v);

v = MulByPow2(LFSR_S13, 17);

f = AddM(f, v);

v = MulByPow2(LFSR_S15, 15);

f = AddM(f, v);

f = AddM(f, u);

/* update the state */

LFSR_S0 = LFSR_S1;

LFSR_S1 = LFSR_S2;

LFSR_S2 = LFSR_S3;

LFSR_S3 = LFSR_S4;

LFSR_S4 = LFSR_S5;

LFSR_S5 = LFSR_S6;

LFSR_S6 = LFSR_S7;

LFSR_S7 = LFSR_S8;

LFSR_S8 = LFSR_S9;

LFSR_S9 = LFSR_S10;

LFSR_S10 = LFSR_S11;

LFSR_S11 = LFSR_S12;

LFSR_S12 = LFSR_S13;

LFSR_S13 = LFSR_S14;

LFSR_S14 = LFSR_S15;

LFSR_S15 = f;

}

/* LFSR with work mode */

void LFSRWithWorkMode() {

u32 f, v;

f = LFSR_S0;

v = MulByPow2(LFSR_S0, 8);

f = AddM(f, v);

v = MulByPow2(LFSR_S4, 20);

f = AddM(f, v);

v = MulByPow2(LFSR_S10, 21);

f = AddM(f, v);

v = MulByPow2(LFSR_S13, 17);

f = AddM(f, v);

v = MulByPow2(LFSR_S15, 15);

f = AddM(f, v);

/* update the state */

LFSR_S0 = LFSR_S1;

LFSR_S1 = LFSR_S2;

LFSR_S2 = LFSR_S3;

LFSR_S3 = LFSR_S4;

LFSR_S4 = LFSR_S5;

LFSR_S5 = LFSR_S6;

LFSR_S6 = LFSR_S7;

LFSR_S7 = LFSR_S8;

LFSR_S8 = LFSR_S9;

LFSR_S9 = LFSR_S10;

LFSR_S10 = LFSR_S11;

LFSR_S11 = LFSR_S12;

LFSR_S12 = LFSR_S13;

LFSR_S13 = LFSR_S14;

LFSR_S14 = LFSR_S15;

LFSR_S15 = f;

}

/* BitReorganization */

void BitReorganization() {

BRC_X0 = ((LFSR_S15 & 0x7FFF8000) << 1) | (LFSR_S14 & 0xFFFF);

BRC_X1 = ((LFSR_S11 & 0xFFFF) << 16) | (LFSR_S9 >> 15);

BRC_X2 = ((LFSR_S7 & 0xFFFF) << 16) | (LFSR_S5 >> 15);

BRC_X3 = ((LFSR_S2 & 0xFFFF) << 16) | (LFSR_S0 >> 15);

}

#define ROT(a, k) (((a) << k) | ((a) >> (32 - k)))

/* L1 */

u32 L1(u32 X) {

return (X ^ ROT(X, 2) ^ ROT(X, 10) ^ ROT(X, 18) ^ ROT(X, 24));

}

/* L2 */

u32 L2(u32 X) {

return (X ^ ROT(X, 8) ^ ROT(X, 14) ^ ROT(X, 22) ^ ROT(X, 30));

}

#define MAKEU32(a, b, c, d) (((u32)(a) << 24) | ((u32)(b) << 16)| ((u32)(c) << 8) | ((u32)(d)))

/* F */

u32 F() {

u32 W, W1, W2, u, v;

W = (BRC_X0 ^ F_R1) + F_R2;

W1 = F_R1 + BRC_X1;

W2 = F_R2 ^ BRC_X2;

u = L1((W1 << 16) | (W2 >> 16));

v = L2((W2 << 16) | (W1 >> 16));

F_R1 = MAKEU32(S0[u >> 24], S1[(u >> 16) & 0xFF],

S0[(u >> 8) & 0xFF], S1[u & 0xFF]);

F_R2 = MAKEU32(S0[v >> 24], S1[(v >> 16) & 0xFF],

S0[(v >> 8) & 0xFF], S1[v & 0xFF]);

return W;

}

#define MAKEU31(a, b, c) (((u32)(a) << 23) | ((u32)(b) << 8) | (u32)(c))

/* initialize */

void Initialization(unsigned char *k, unsigned char *iv) {

u32 w, nCount;

/* expand key */

LFSR_S0 = MAKEU31(k[0], EK_d[0], iv[0]);

LFSR_S1 = MAKEU31(k[1], EK_d[1], iv[1]);

LFSR_S2 = MAKEU31(k[2], EK_d[2], iv[2]);

LFSR_S3 = MAKEU31(k[3], EK_d[3], iv[3]);

LFSR_S4 = MAKEU31(k[4], EK_d[4], iv[4]);

LFSR_S5 = MAKEU31(k[5], EK_d[5], iv[5]);

LFSR_S6 = MAKEU31(k[6], EK_d[6], iv[6]);

LFSR_S7 = MAKEU31(k[7], EK_d[7], iv[7]);

LFSR_S8 = MAKEU31(k[8], EK_d[8], iv[8]);

LFSR_S9 = MAKEU31(k[9], EK_d[9], iv[9]);

LFSR_S10 = MAKEU31(k[10], EK_d[10], iv[10]);

LFSR_S11 = MAKEU31(k[11], EK_d[11], iv[11]);

LFSR_S12 = MAKEU31(k[12], EK_d[12], iv[12]);

LFSR_S13 = MAKEU31(k[13], EK_d[13], iv[13]);

LFSR_S14 = MAKEU31(k[14], EK_d[14], iv[14]);

LFSR_S15 = MAKEU31(k[15], EK_d[15], iv[15]);

/* set F_R1 and F_R2 to zero */

F_R1 = 0;

F_R2 = 0;

nCount = 32;

while (nCount > 0) {

BitReorganization();

w = F();

LFSRWithInitialisationMode(w >> 1);

nCount--;

}

void GenerateKeyStream(unsigned int *pKeyStream, unsigned int KeyStreamLen){

int i;

{

BitReorganization();

F(); /* discard the output of F */

LFSRWithWorkMode();

}

for (i = 0; i < KeyStreamLen; i++) {

BitReorganization();

pKeyStream[i] = F() ^ BRC_X3;

LFSRWithWorkMode();

}

B. C++实现(和C基本一样)

#include "ZUC.h"

/* state registers LFSR */

unsigned int LFSR_S[16] ;

/* F registers */

unsigned int F_R1 ;

unsigned int F_R2 ;

/* output of BR procedure */

unsigned int BRC_X[4] ;

/* S-boxes */