[C语言]mac下Des CBC加密
加密步骤如下：
1）首先将数据按照8个字节一组进行分组得到D1D2......Dn（若数据不是8的整数倍，用指定的PADDING数据补位）
2）第一组数据D1与初始化向量I异或后的结果进行DES加密得到第一组密文C1（初始化向量I为全零）
3）第二组数据D2与第一组的加密结果C1异或以后的结果进行DES加密，得到第二组密文C2
4）之后的数据以此类推，得到Cn
5）按顺序连为C1C2C3......Cn即为加密结果。
3Des.h文件
#ifndef _3DES
#define _3DES
#include <strings.h>
#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */
unsigned char* GetKey(unsigned char *RandomData);
void DesEncrypt_ECB(unsigned char *key, unsigned char *data);
unsigned char* DesEncrypt_CBC(unsigned char *key, unsigned char *data,int len);
#ifdef __cplusplus
};
#endif /* __cplusplus */
#endif /* defined(_3DES) */
3Des.cpp文件
#include "3DES.h"
#include "DES.h"
#include <iostream>
unsigned char* GetKey(unsigned char *RandomData){
unsigned char* key=(unsigned char*)malloc(16);
for (int i=0; i<16; i++) {
key[i]=0xFF;
}
unsigned char RevertData[8]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
for (int i=0; i<sizeof(RevertData); i++) {
RevertData[i]=~RandomData[i];
}
DesEncrypt_ECB(key, RandomData);
DesEncrypt_ECB(key, RevertData);
for (int i=0; i<16; i++) {
if(i<8)
key[i]=RandomData[i];
else
key[i]=RevertData[i-8];
}
return key;
}
void DesEncrypt_ECB(unsigned char *key, unsigned char *data){
DesEncrypt(key,data);
DesDecrypt(key,data);
DesEncrypt(key,data);
}
unsigned char* DesEncrypt_CBC(unsigned char *key, unsigned char *data, int len){
unsigned char* data2=(unsigned char*)malloc(8);
unsigned char data3[8];
int sum=len/8+1;
int yushu=len%8;
for (int i=0;i<sum;i++) {
for (int j=0; j<8; j++) {
if(i<sum-1){
data2[j]=data[i*8+j];
if(j==7&&i==0){
DesEncrypt(key, data2);
for (int k=0; k<8; k++) {
data3[k]=data2[k];
}
}else if(j==7&&i>0){
for (int k=0; k<8; k++) {
data2[k]^=data3[k];
}
DesEncrypt(key, data2);
for (int k=0; k<8; k++) {
data3[k]=data2[k];
}
}
}else if(yushu==0&&i==sum-1&&j==7){
data2[0]=0x80;
for(int k=1;k<8;k++){
data2[k]=0x00;
}
for (int k=0; k<8; k++) {
data2[k]^=data3[k];
}
DesEncrypt(key, data2);
}else if(yushu>0){
if(j<yushu){
data2[j]=data[i*8+j];
}else if(j==yushu){
data2[j]=0x80;
}else if(j>yushu&&j!=7){
data2[j]=0x00;
}else if(j==7){
data2[j]=0x00;
for (int k=0; k<8; k++) {
data2[k]^=data3[k];
}
DesEncrypt(key, data2);
}
}
}
}
return data2;
}
main函数
unsigned char RandomData[16]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
unsigned char* key=GetKey(RandomData);
unsigned char data[17]={0x14,0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
unsigned char* macdata=DesEncrypt_CBC(key,data,sizeof(data));
for (int i=0; i<8; i++) {
printf("%x\n",macdata[i]);
}
free(macdata);
free(key);