DES.rar_算法学习

#include <stdio.h> #include <string.h> #include <memory.h> /*密钥置换选择表PC_1*/ const char PC_1[56]={ 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 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 }; /*左移循环表Left_loop*/ const char Left_loop[16]={ 1,1,2,2,2,2,2,2,1, 2, 2, 2, 2, 2, 2,1 }; /*密钥置换选择表PC_2*/ const char PC_2[48]={ 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 }; /*数据初始变换表*/ const char IP[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 }; /*扩展表*/ const char Exp[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 }; /*S_Box*/ const static char S[8][4][16] = { 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, 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, 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, 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, 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, 8, 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 }; /*把从S盒中得到的数据重新排列的表*/ const char PP[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 }; /*逆IP置换*/ const char FP[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 }; /* 密钥定义*/ static unsigned char DesKey[8]; static unsigned char SubKey[16][48]; static unsigned char tmp[128]; void trans_table(char * Out ,char * In , const char * Table , int len) {//按照table表格将输入数据顺序修改 int i; for(i=0;i!=len;i++) tmp[i]=In[Table[i]-1]; memcpy(Out , tmp , len); } void Bytes_to_Bits(unsigned char * Out , const unsigned char * In , int len) { int i; for(i=0;i!=len;i++) { Out[i]=(In[i>>3]>>(i&7)) & 1; } } void Bits_to_Bytes(unsigned char * Out , const unsigned char * In , int len) { int i; memset(Out, 0,len>>3); for(i=0;i!=len;i++) { Out[i>>3] |= (In[i]<<(i&7)); } } void Xor(unsigned char * Out , unsigned char * In , int len) { int i; for(i=0;i!=len;i++) if(Out[i]!=In[i]) Out[i]=1; else Out[i]=0; } void Rotate(unsigned char * In , int len , int loop) { memcpy(tmp,In,loop); memcpy(In,In+loop,loop); memcpy(In+len-loop,tmp,loop); } void Set_Subkey(unsigned char * key) { int i=strlen(key); // char C[2],D[2]; char tk[64]; if(i>8) memcpy(DesKey,key,8); else { memset(DesKey,0,8); memcpy(DesKey,key,i); } Bytes_to_Bits(tk,DesKey,64); trans_table(tk,tk,PC_1,56); for(i=0;i!=16;i++) { Rotate(&tk[0],28,Left_loop[i]); Rotate(&tk[28],28,Left_loop[i]); trans_table(SubKey[i],tk,PC_2,48); } } void S_func(unsigned char E[48],unsigned char B[32]) { int i,j,k; for(i=0;i!=8;i++,E+=6,B+=4) { j=(E[0]<<1)+E[5]; k=(E[1]<<3)+(E[2]<<2)+(E[3]<<1)+E[4]; Bytes_to_Bits(B,&S[i][j][k],4); } } void F_func(unsigned char RL[32], char unsigned key[48] ,unsigned char B[32]) { unsigned char E[48]; trans_table(E,RL,Exp,48); Xor(E,key,48); S_func(E,B); trans_table(B,B,PP,32); } void Des_E(unsigned char In[8] , unsigned char Out[8] ) { unsigned char tt[64],B[32] , * L=&tt[0] , *R=&tt[32] ; int i; Bytes_to_Bits(tt,In,64); trans_table(tt,tt,IP,64); for(i=0;i!=16;i++) { F_func(R,SubKey[i],B); Xor(B,L,32); memcpy(L,R,32); memcpy(R,B,32); } trans_table(tt,tt,FP,64); Bits_to_Bytes(Out,tt,64); } void Des_D(unsigned char In[8] , unsigned char Out[8] ) { unsigned char tt[64],B[32],*L=&tt[0],*R=&tt[32]; int i; Bytes_to_Bits(tt,In,64); trans_table(tt,tt,IP,64); for(i=15;i>=0;i--) { F_func(L,SubKey[i],B); Xor(B,R,32); memcpy(R,L,32); memcpy(L,B,32); } trans_table(tt,tt,FP,64); Bits_to_Bytes(Out,tt,64); } int main() { int i,j,len; unsigned char In[128]; unsigned char Out[128]; unsigned char D_Out[128]; unsigned char key[16]; printf("请输入密钥（8位）:"); scanf("%s",&key); printf("%s\n",key); Set_Subkey(key); memset(In,0,128); memset(Out,0,128); printf("请输入要加密的内容（100位以内）:\n"); scanf("%s",In); len=strlen(In); printf("\n输入字符串长为: %d\n",len); j=len>>3; for(i=0;i!=j+1;i++) { Des_E(In+(i*8),Out+(i*8)); } printf("加密结果用ASCII码形式表示为:\n"); for(i=0;i!=len>>3;i++) { for(j=0;j!=8;j++) printf("%c ",Out[(i<<3)+j]); printf("\n"); } for(i=(len>>3)<<3;i!=len;i++) printf("%c ",Out[i]); printf("\n"); printf("\n"); printf("加密结果用二进制形式表示为:\n"); for(i=0;i!=len>>2;i++) { Bytes_to_Bits(tmp,Out+(i<<2),32); for(j=0;j!=32;j++) { printf("%d ",tmp[j]); } printf("\n"); } for(i=(len>>3)<<3;i!=len;i++) { Bytes_to_Bits(tmp,Out+i,8); for(j=0;j!=8;j++) { printf("%d ",tmp[j]); } } printf("\n"); printf("\n"); printf("加密结果用十六进制形式表示为:\n"); for(i=0;i!=(len>>3);i++) { for(j=0;j!=8;j++) printf("%2x ",Out[(i<<3)+j]); printf("\n"); }