3DES加密算法C语言实现

#include "memory.h" #include "3des.h" #include "stdio.h" #include <stdlib.h> /*********************************************************/ static void F_func(bool In[32], const bool Ki[48]);// f 函数 static void S_func(bool Out[32], const bool In[48]);// S 盒代替 static void Transform(bool *Out, bool *In, const char *Table, int len);// 变换 static void Xor(bool *InA, const bool *InB, int len);// 异或 static void RotateL(bool *In, int len, int loop);// 循环左移 static void ByteToBit(bool *Out, const char *In, int bits);// 字节组转换成位组 static void BitToByte(char *Out, const bool *In, int bits);// 位组转换成字节组 static bool SubKey[16][48];// 16圈子密钥 /*********************************************************/ /************************加密*********************************/ int Encrypt(char *Msg, char *Key, char *Cipher,int length) //如果消息长度不是8的倍数，末位补0凑成8的倍数。 { if(length <=0) { return -1; } char keyarray1[8]; char keyarray2[8]; char keyarray3[8]; memcpy(&keyarray1, &Key[0], 8); memcpy(&keyarray2, &Key[8], 8); memcpy(&keyarray3, &Key[16], 8); if (length%8==0) { int dst = length/8; char out[8]; char in[8]; for (int j=0;j<dst;j++) { memcpy(&in[0], &Msg[8*j], 8); encrypt(in, keyarray1, out);/////////////////// decrypt(out, keyarray2, in);////////////////// encrypt(in, keyarray3, out);////////////////// memcpy(&Cipher[8*j], &out, 8); } return 1; }else { int ext = length/8; int dst = length%8; char * temp_in ; char * temp_add; temp_in = (char *) malloc((ext+1)*8); temp_add = (char *)malloc(8-dst); memcpy(&temp_in[0], &Msg[0], length); memset(temp_add, 0, 8-dst); memcpy(&temp_in[length],&temp_add[0], 8-dst); int round = ext+1; char out [8]; char in[8]; for (int j=0;j<round;j++) { memcpy(&in[0], &temp_in[8*j], 8); encrypt(in, keyarray1, out); decrypt(out, keyarray2, in); encrypt(in, keyarray3, out); memcpy(&Cipher[8*j], &out, 8); } return 1; } } void encrypt(char In[8], const char Key[8], char Out[8]) { Des_SetKey(Key); static bool M[64], Tmp[32], *Li = &M[0], *Ri = &M[32]; ByteToBit(M, In, 64); Transform(M, M, IP_Table, 64); for(int i=0; i<16; i++) { memcpy(Tmp, Ri, 32); F_func(Ri, SubKey[i]); Xor(Ri, Li, 32); memcpy(Li, Tmp, 32); } Transform(M, M, IPR_Table, 64); BitToByte(Out, M, 64); } /************************解密*********************************/ int Decrypt(char *Msg, char *Key, char *Cipher,int length)//如果消息长度不是8的倍数，末位补0凑成8的倍数。 { if(length <=0) { return -1; } char keyarray1[8]; char keyarray2[8]; char keyarray3[8]; memcpy(&keyarray1, &Key[0], 8); memcpy(&keyarray2, &Key[8], 8); memcpy(&keyarray3, &Key[16], 8); if (length%8==0) { int dst = length/8; char out [8]; char in[8]; for (int j=0;j<dst;j++) { memcpy(&in[0], &Msg[8*j], 8); decrypt(in, keyarray3, out); encrypt(out, keyarray2, in); decrypt(in, keyarray1, out); memcpy(&Cipher[8*j], &out, 8); } return 1; }else { int ext = length/8; int dst = length%8; char * temp_in ; char * temp_add; temp_in = (char *) malloc((ext+1)*8); temp_add = (char *)malloc(8-dst); memcpy(&temp_in[0], &Msg[0], length); memset(temp_add, 0, 8-dst); memcpy(&temp_in[length],&temp_add[0], 8-dst); int round = ext+1; char out [8]; char in[8]; for (int j=0;j<round;j++) { memcpy(&in[0], &temp_in[8*j], 8); decrypt(in, keyarray3, out); encrypt(out, keyarray2, in); decrypt(in, keyarray1, out); memcpy(&Cipher[8*j], &out, 8); } return 1; } } void decrypt(char In[8], const char Key[8], char Out[8]) { Des_SetKey(Key); static bool M[64], Tmp[32], *Li = &M[0], *Ri = &M[32]; ByteToBit(M, In, 64); Transform(M, M, IP_Table, 64); for(int i=15; i>=0; i--) { memcpy(Tmp, Li, 32); F_func(Li, SubKey[i]); Xor(Li, Ri, 32); memcpy(Ri, Tmp, 32); } Transform(M, M, IPR_Table, 64); BitToByte(Out, M, 64); } /********************设置密钥*****************************/ void Des_SetKey(const char Key[8]) { static bool K[64], *KL = &K[0], *KR = &K[28]; ByteToBit(K, Key, 64); Transform(K, K, PC1_Table, 56); for(int i=0; i<16; i++) { RotateL(KL, 28, LOOP_Table[i]); RotateL(KR, 28, LOOP_Table[i]); Transform(SubKey[i], K, PC2_Table, 48); } } /*********************************************************/ void F_func(bool In[32], const bool Ki[48]) { static bool MR[48]; Transform(MR, In, E_Table, 48); Xor(MR, Ki, 48); S_func(In, MR); Transform(In, In, P_Table, 32); } void S_func(bool Out[32], const bool In[48]) { for(char i=0,j,k; i<8; i++,In+=6,Out+=4) { j = (In[0]<<1) + In[5]; k = (In[1]<<3) + (In[2]<<2) + (In[3]<<1) + In[4]; ByteToBit(Out, &S_Box[i][j][k], 4); } } void Transform(bool *Out, bool *In, const char *Table, int len) { static bool Tmp[256]; for(int i=0; i<len; i++) Tmp[i] = In[ Table[i]-1 ]; memcpy(Out, Tmp, len); } void Xor(bool *InA, const bool *InB, int len) { for(int i=0; i<len; i++) InA[i] ^= InB[i]; } void RotateL(bool *In, int len, int loop) { static bool Tmp[256]; memcpy(Tmp, In, loop); memcpy(In, In+loop, len-loop); memcpy(In+len-loop, Tmp, loop); } void ByteToBit(bool *Out, const char *In, int bits) { for(int i=0; i<bits; i++) Out[i] = (In[i/8]>>(i%8)) & 1; } void BitToByte(char *Out, const bool *In, int bits) { memset(Out, 0, (bits+7)/8); for(int i=0; i<bits; i++) Out[i/8] |= In[i]<<(i%8); } /********************* end *********************************/