天理密码学实验2.docx

1、天理密码学实验2实验报告学院（系）名称：计算机与通信工程学院姓名吴晋昌学号 20125879专业网络工程班级1班实验项目实验二 DES密码编程课程名称密码学实验课程代码实验时间2014.6.4 10：1011：30实验地点计算机软件实验室7-215批改意见成绩教师签字： 一、 实验目的掌握DES加密算法，学会用DES对明文进行加密。二、 实验内容使用VC+6.0编译器，运用DES对明文进行加密编程。三、 DES简介1977年1月15日美国正式公布实施的数据加密标准DES（data encryption standard）是一个众所周知的分组密码，其分组长度为64比特（bit）,密钥长度也为64

2、比特。密钥中有8比特奇偶校验位，实际密钥长度只有56比特，尽管DES目前已被高级加密标准AES所取代，但其设计思想仍然值得借鉴。四、 程序代码#include#include#include/初始置换IPconst int IP64 = 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,

3、15,7 ;/初始逆置换IP_1const int IP_164 = 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 ;/选择置换PC_1const int PC_156 = 57,49,41,33,25,17,9,1,58,50,42,34,26,18, 10,2,59,5

4、1,43,35,27,19,11,3,60,52,44,36, 63,55,47,39,31,23,15,7,62,54,46,38,30,22, 14,6,61,53,45,37,29,21,13,5,28,20,12,4 ;/选择置换PC_2const int PC_248 = 14,17,11,24,1,5,3,28,15,6 ,21,10, 23,19,12,4,26,8,16,7 ,27,20,13,2 , 41,52,31,37,47,55,30,40,51,45,33,48, 44,49,39,56,34,53,46,42,50,36,29,32 ;/位选择函数Econst in

5、t E48 = 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 ;/置换函数Pconst int P32=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 ;/S盒const int S3216 = 14,4,

6、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, 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

7、,14,9, 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, 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

8、,4,5,11,12,7,2,14, 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, 12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11, 10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8, 9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6, 4,3,2,12

9、,9,5,15,10,11,14,1,7,6,0,8,13, 4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1, 13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6, 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, 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

10、,8, 2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11 ;/循环左移位数表const int circulate16 = 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 ;/字符串转变成二进制int *CharToBit(char *s) int *bit ; int i,j,mask ; bit = (int *)malloc(64*sizeof(int) ; for(i=0;i8;i+) mask = 1 ; for(j=0;j=1 ; return bit ;/二进制转字符char *BitToChar(int *bit) int i,j,k

11、; char *s ; s = (char *)malloc(9*sizeof(char) ; for(i=0;i8;i+) k = 0 ; for(j=0;j8;j+) k = k + pow(2,7-j)*bit8*i+j ; si = k ; s8 = 0 ; return s ;/初始置换int *InitPermutation(int *bit) int *IP_bit ; int i ; IP_bit = (int *)malloc(64*sizeof(int) ; for(i=0;i64;i+) IP_biti = bitIPi-1 ; return IP_bit ;/初始逆置换

12、int *InverseInitPermutation(int *bit) int *IP_1_bit ; int i ; IP_1_bit = (int *)malloc(64*sizeof(int) ; for(i=0;i64;i+) IP_1_biti = bitIP_1i-1 ; return IP_1_bit ;/选择置换pc_1int *PC_1Permutation(int *key) int *keyPC_1 ; int i ; keyPC_1 = (int *)malloc(56*sizeof(int) ; for(i=0;i56;i+) keyPC_1i = keyPC_1

13、i-1 ; /printf(%dt,keyPC_1i) ; return keyPC_1 ;/选择置换pc_2int *PC_2Permutation(int *key) int *keyPC_2 ; int i ; keyPC_2 = (int *)malloc(48*sizeof(int) ; for(i=0;i48;i+) keyPC_2i = keyPC_2i-1 ; return keyPC_2 ;/循环移位操作int *CircuTransposition(int *keyPC_1,int cir) int *LS ; int i,k,j2 ; LS = (int *)malloc

14、(56*sizeof(int) ; for(i=0;i56;i+) LSi = keyPC_1i ; /循环位移操作 for(k=0;kcir;k+) j0 = LS0 ; j1 = LS28 ; for(i=0;i27;i+) LSi = LSi+1 ; LSi+28 = LSi+29 ; LSi = j0 ; LSi+28 = j1 ; return LS ;/位选择函数Eint *BitSelect(int *bit_1) int *bit_E ; int i ; bit_E = (int *)malloc(48*sizeof(int) ; for(i=0;i48;i+) bit_Ei

15、= bit_1Ei-1 ; return bit_E ;/模2加运算int *Xor(int *k,int *bit_E) int *B ; int i ; B = (int *)malloc(48*sizeof(int) ; for(i=0;i48;i+) if(ki=bit_Ei) Bi = 0 ; else Bi = 1 ; return B ;/十进制转二进制int *DecimalToBinary(int dec) int *bin ; int i=0 ; int k = dec ; bin = (int *)malloc(4*sizeof(int) ; while(i=8) bin

16、0 = 1 ; k = k-8 ; if(k=4) bin1 = 1 ; k = k-4 ; if(k=2) bin2 = 1 ; k = k-2 ; if(k=1) bin3 = 1 ; return bin ;/s盒int *SSelect(int *B) int *s ; int *bin ; int i,j,k ; s = (int *)malloc(32*sizeof(int) ; for(i=0;i8;i+) /找到对应的s盒数值 bin = DecimalToBinary(SBi*6*2+Bi*6+1*1Bi*6+2*8+Bi*6+3*4+Bi*6+4*2+Bi*6+5*1) ;

17、 si*4 = bin0 ; si*4+1 = bin1 ; si*4+2 = bin2 ; si*4+3 = bin3 ; return s ;/置换函数Pint *PPermutation(int *s) int *p ; int i ; p = (int *)malloc(32*sizeof(int) ; for(i=0;i32;i+) pi = sPi-1 ; return p ;/K的产生int *GenerateK(char *key) int *k ; /二维数组保存16次迭代的k int *k_binary ; /保存二进制的密钥 int *pc_1_k ; /经过pc_1置换

18、后的密钥 int *pc_2_k ; /保存经过pc_2置换后密钥 int *ls,*ls_new ; /保存经过循环移位操作的值 int i,j ; k = (int *)malloc(16*sizeof(int *) ; for(i=0;i16;i+) ki = (int *)malloc(48*sizeof(int) ; k_binary = CharToBit(key) ; /密钥字符转二进制 pc_1_k = PC_1Permutation(k_binary) ; /密钥二进制进行pc_1置换 ls_new = pc_1_k ; for(i=0;i16;i+) ls = CircuT

19、ransposition(ls_new,circulatei-1) ; /取得相应移位后结果 pc_2_k = PC_2Permutation(ls) ; for(j=0;j48;j+) kij = pc_2_kj ; /保存到ki表中 ls_new = ls ; return k ;/DES加密int *DES(char *s,char *key) int *s_binary ; /保存要加密内容的二进制值 int *IP_s ; /初始置换后的值 int *IP_1_s ; /初始逆置换的值 int *k ; /保存ki int *E_R ; /保存R经过E置换的值 int *Xor_E_

20、R_K ; /保存ki和R（i-1）置换后经过异或运算的值 int *s_select ; /保存经过s盒选择的值 int *f_R_K ; /保存f函数的值 int i,j ; int L32,R32 ; /保存明文或者加密i次的明文的左边一半和右边一半 int temp32 ; int *new_r ; /保存和f函数异或运算的值 int *Ciphertext_binary ; Ciphertext_binary = (int *)malloc(64*sizeof(int) ; /char *Ciphertext ; s_binary = CharToBit(s) ; IP_s = In

21、itPermutation(s_binary) ; /for(i=0;i64;i+) / printf(%d,IP_si) ; /printf(n) ; k = GenerateK(key) ; for(i=0;i32;i+) /将初始置换IP后的值保存为左右两部分 Li = IP_si ; Ri = IP_si+32 ; for(i=0;i16;i+) for(j=0;j32;j+) tempj = Lj ; /保存原先左边值，用于计算 Lj = Rj ; /右半边值给左边 E_R = BitSelect(R) ; Xor_E_R_K = Xor(E_R,ki) ; s_select = S

22、Select(Xor_E_R_K) ; f_R_K = PPermutation(s_select) ; new_r = Xor(f_R_K,temp) ; for(j=0;j32;j+) Rj = new_rj ; for(i=0;i32;i+) Ciphertext_binaryi = Li ; Ciphertext_binaryi+32 = Ri ; /*加密后由于可能出现超出ascii表的值，所以在这里重新转化 *为字符会出问题，这里就不将加密后的结果转化为字符 *Ciphertext = BitToChar(Ciphertext_binary) ; */ return Ciphert

23、ext_binary ;int main() char *s ; /保存明文 char *key ; /保存密钥 int *Ciphertext ; /保存密文的二进制值 int i=0 ; s = (char *)malloc(8*sizeof(char) ; key = (char *)malloc(9*sizeof(char) ; printf(*DES加密算法*nn) ; printf(请输入明文(8 字节):) ; gets(s) ; printf(n) ; getchar ; printf(请输入密钥(8 字节):) ; gets(key) ; Ciphertext = DES(s,key) ; printf(n) ; printf(密文:) ; i = 0 ; while(i64) printf(%d,Ciphertexti) ; i+ ; printf(n); return ;五、 实验结果