OpenSSL中对称加密算法DES常用函数使用举例

#ifndef _CRYPTOTEST_H_
#define _CRYPTOTEST_H_

#include <string>

using namespace std;

typedef enum {
GENERAL = 0,
ECB,
CBC,
CFB,
OFB,
TRIPLE_ECB,
TRIPLE_CBC
}CRYPTO_MODE;

string DES_Encrypt(const string cleartext, const string key, CRYPTO_MODE mode);
string DES_Decrypt(const string ciphertext, const string key, CRYPTO_MODE mode);

#endif //_CRYPTOTEST_H_

#include <iostream>
#include <string>
#include <vector>
#include <openssl/des.h>
#include "cryptotest.h"

using namespace std;

static unsigned char cbc_iv[8] = {'0', '1', 'A', 'B', 'a', 'b', '9', '8'};

string DES_Encrypt(const string cleartext, const string key, CRYPTO_MODE mode)
{
string strCipherText;

switch (mode) {
case GENERAL:
case ECB:
{
DES_cblock keyEncrypt;
memset(keyEncrypt, 0, 8);

if (key.length() <= 8)
memcpy(keyEncrypt, key.c_str(), key.length());
else
memcpy(keyEncrypt, key.c_str(), 8);

DES_key_schedule keySchedule;
DES_set_key_unchecked(&keyEncrypt, &keySchedule);

const_DES_cblock inputText;
DES_cblock outputText;
vector<unsigned char> vecCiphertext;
unsigned char tmp[8];

for (int i = 0; i < cleartext.length() / 8; i ++) {
memcpy(inputText, cleartext.c_str() + i * 8, 8);
DES_ecb_encrypt(&inputText, &outputText, &keySchedule, DES_ENCRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCiphertext.push_back(tmp[j]);
}

if (cleartext.length() % 8 != 0) {
int tmp1 = cleartext.length() / 8 * 8;
int tmp2 = cleartext.length() - tmp1;
memset(inputText, 0, 8);
memcpy(inputText, cleartext.c_str() + tmp1, tmp2);

DES_ecb_encrypt(&inputText, &outputText, &keySchedule, DES_ENCRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCiphertext.push_back(tmp[j]);
}

strCipherText.clear();
strCipherText.assign(vecCiphertext.begin(), vecCiphertext.end());
}
break;
case CBC:
{
DES_cblock keyEncrypt, ivec;
memset(keyEncrypt, 0, 8);

if (key.length() <= 8)
memcpy(keyEncrypt, key.c_str(), key.length());
else
memcpy(keyEncrypt, key.c_str(), 8);

DES_key_schedule keySchedule;
DES_set_key_unchecked(&keyEncrypt, &keySchedule);

memcpy(ivec, cbc_iv, sizeof(cbc_iv));

int iLength = cleartext.length() % 8 ? (cleartext.length() / 8 + 1) * 8 : cleartext.length();
unsigned char* tmp = new unsigned char[iLength + 16];
memset(tmp, 0, iLength);

DES_ncbc_encrypt((const unsigned char*)cleartext.c_str(), tmp, cleartext.length()+1, &keySchedule, &ivec, DES_ENCRYPT);

strCipherText = (char*)tmp;

delete [] tmp;
}
break;
case CFB:
{
DES_cblock keyEncrypt, ivec;
memset(keyEncrypt, 0, 8);

if (key.length() <= 8)
memcpy(keyEncrypt, key.c_str(), key.length());
else
memcpy(keyEncrypt, key.c_str(), 8);

DES_key_schedule keySchedule;
DES_set_key_unchecked(&keyEncrypt, &keySchedule);

memcpy(ivec, cbc_iv, sizeof(cbc_iv));

unsigned char* outputText = new unsigned char[cleartext.length()];
memset(outputText, 0, cleartext.length());

const unsigned char* tmp = (const unsigned char*)cleartext.c_str();

DES_cfb_encrypt(tmp, outputText, 8, cleartext.length(), &keySchedule, &ivec, DES_ENCRYPT);

strCipherText = (char*)outputText;

delete [] outputText;
}
break;
case TRIPLE_ECB:
{
DES_cblock ke1, ke2, ke3;
memset(ke1, 0, 8);
memset(ke2, 0, 8);
memset(ke2, 0, 8);

if (key.length() >= 24) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, 8);
} else if (key.length() >= 16) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, key.length() - 16);
} else if (key.length() >= 8) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, key.length() - 8);
memcpy(ke3, key.c_str(), 8);
} else {
memcpy(ke1, key.c_str(), key.length());
memcpy(ke2, key.c_str(), key.length());
memcpy(ke3, key.c_str(), key.length());
}

DES_key_schedule ks1, ks2, ks3;
DES_set_key_unchecked(&ke1, &ks1);
DES_set_key_unchecked(&ke2, &ks2);
DES_set_key_unchecked(&ke3, &ks3);

const_DES_cblock inputText;
DES_cblock outputText;
vector<unsigned char> vecCiphertext;
unsigned char tmp[8];

for (int i = 0; i < cleartext.length() / 8; i ++) {
memcpy(inputText, cleartext.c_str() + i * 8, 8);
DES_ecb3_encrypt(&inputText, &outputText, &ks1, &ks2, &ks3, DES_ENCRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCiphertext.push_back(tmp[j]);
}

if (cleartext.length() % 8 != 0) {
int tmp1 = cleartext.length() / 8 * 8;
int tmp2 = cleartext.length() - tmp1;
memset(inputText, 0, 8);
memcpy(inputText, cleartext.c_str() + tmp1, tmp2);

DES_ecb3_encrypt(&inputText, &outputText, &ks1, &ks2, &ks3, DES_ENCRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCiphertext.push_back(tmp[j]);
}

strCipherText.clear();
strCipherText.assign(vecCiphertext.begin(), vecCiphertext.end());
}
break;
case TRIPLE_CBC:
{
DES_cblock ke1, ke2, ke3, ivec;
memset(ke1, 0, 8);
memset(ke2, 0, 8);
memset(ke2, 0, 8);

if (key.length() >= 24) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, 8);
} else if (key.length() >= 16) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, key.length() - 16);
} else if (key.length() >= 8) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, key.length() - 8);
memcpy(ke3, key.c_str(), 8);
} else {
memcpy(ke1, key.c_str(), key.length());
memcpy(ke2, key.c_str(), key.length());
memcpy(ke3, key.c_str(), key.length());
}

DES_key_schedule ks1, ks2, ks3;
DES_set_key_unchecked(&ke1, &ks1);
DES_set_key_unchecked(&ke2, &ks2);
DES_set_key_unchecked(&ke3, &ks3);

memcpy(ivec, cbc_iv, sizeof(cbc_iv));

int iLength = cleartext.length() % 8 ? (cleartext.length() / 8 + 1) * 8 : cleartext.length();
unsigned char* tmp = new unsigned char[iLength + 16];
memset(tmp, 0, iLength);

DES_ede3_cbc_encrypt((const unsigned char*)cleartext.c_str(), tmp, cleartext.length()+1, &ks1, &ks2, &ks3, &ivec, DES_ENCRYPT);

strCipherText = (char*)tmp;

delete [] tmp;
}
break;
}

return strCipherText;
}

string DES_Decrypt(const string ciphertext, const string key, CRYPTO_MODE mode)
{
string strClearText;

switch (mode) {
case GENERAL:
case ECB:
{
DES_cblock keyEncrypt;
memset(keyEncrypt, 0, 8);

if (key.length() <= 8)
memcpy(keyEncrypt, key.c_str(), key.length());
else
memcpy(keyEncrypt, key.c_str(), 8);

DES_key_schedule keySchedule;
DES_set_key_unchecked(&keyEncrypt, &keySchedule);

const_DES_cblock inputText;
DES_cblock outputText;
vector<unsigned char> vecCleartext;
unsigned char tmp[8];

for (int i = 0; i < ciphertext.length() / 8; i ++) {
memcpy(inputText, ciphertext.c_str() + i * 8, 8);
DES_ecb_encrypt(&inputText, &outputText, &keySchedule, DES_DECRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCleartext.push_back(tmp[j]);
}

if (ciphertext.length() % 8 != 0) {
int tmp1 = ciphertext.length() / 8 * 8;
int tmp2 = ciphertext.length() - tmp1;
memset(inputText, 0, 8);
memcpy(inputText, ciphertext.c_str() + tmp1, tmp2);

DES_ecb_encrypt(&inputText, &outputText, &keySchedule, DES_DECRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCleartext.push_back(tmp[j]);
}

strClearText.clear();
strClearText.assign(vecCleartext.begin(), vecCleartext.end());
}
break;
case CBC:
{
DES_cblock keyEncrypt, ivec;
memset(keyEncrypt, 0, 8);

if (key.length() <= 8)
memcpy(keyEncrypt, key.c_str(), key.length());
else
memcpy(keyEncrypt, key.c_str(), 8);

DES_key_schedule keySchedule;
DES_set_key_unchecked(&keyEncrypt, &keySchedule);

memcpy(ivec, cbc_iv, sizeof(cbc_iv));

int iLength = ciphertext.length() % 8 ? (ciphertext.length() / 8 + 1) * 8 : ciphertext.length();
unsigned char* tmp = new unsigned char[iLength];
memset(tmp, 0, iLength);

DES_ncbc_encrypt((const unsigned char*)ciphertext.c_str(), tmp, ciphertext.length()+1, &keySchedule, &ivec, DES_DECRYPT);

strClearText = (char*)tmp;

delete [] tmp;
}
break;
case CFB:
{
DES_cblock keyEncrypt, ivec;
memset(keyEncrypt, 0, 8);

if (key.length() <= 8)
memcpy(keyEncrypt, key.c_str(), key.length());
else
memcpy(keyEncrypt, key.c_str(), 8);

DES_key_schedule keySchedule;
DES_set_key_unchecked(&keyEncrypt, &keySchedule);

memcpy(ivec, cbc_iv, sizeof(cbc_iv));

unsigned char* outputText = new unsigned char[ciphertext.length()];
memset(outputText, 0, ciphertext.length());

const unsigned char* tmp = (const unsigned char*)ciphertext.c_str();

DES_cfb_encrypt(tmp, outputText, 8, 32/*ciphertext.length() - 16*/, &keySchedule, &ivec, DES_DECRYPT);

strClearText = (char*)outputText;

delete [] outputText;
}
break;
case TRIPLE_ECB:
{
DES_cblock ke1, ke2, ke3;
memset(ke1, 0, 8);
memset(ke2, 0, 8);
memset(ke2, 0, 8);

if (key.length() >= 24) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, 8);
} else if (key.length() >= 16) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, key.length() - 16);
} else if (key.length() >= 8) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, key.length() - 8);
memcpy(ke3, key.c_str(), 8);
} else {
memcpy(ke1, key.c_str(), key.length());
memcpy(ke2, key.c_str(), key.length());
memcpy(ke3, key.c_str(), key.length());
}

DES_key_schedule ks1, ks2, ks3;
DES_set_key_unchecked(&ke1, &ks1);
DES_set_key_unchecked(&ke2, &ks2);
DES_set_key_unchecked(&ke3, &ks3);

const_DES_cblock inputText;
DES_cblock outputText;
vector<unsigned char> vecCleartext;
unsigned char tmp[8];

for (int i = 0; i < ciphertext.length() / 8; i ++) {
memcpy(inputText, ciphertext.c_str() + i * 8, 8);
DES_ecb3_encrypt(&inputText, &outputText, &ks1, &ks2, &ks3, DES_DECRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCleartext.push_back(tmp[j]);
}

if (ciphertext.length() % 8 != 0) {
int tmp1 = ciphertext.length() / 8 * 8;
int tmp2 = ciphertext.length() - tmp1;
memset(inputText, 0, 8);
memcpy(inputText, ciphertext.c_str() + tmp1, tmp2);

DES_ecb3_encrypt(&inputText, &outputText, &ks1, &ks2, &ks3, DES_DECRYPT);
memcpy(tmp, outputText, 8);

for (int j = 0; j < 8; j++)
vecCleartext.push_back(tmp[j]);
}

strClearText.clear();
strClearText.assign(vecCleartext.begin(), vecCleartext.end());
}
break;
case TRIPLE_CBC:
{
DES_cblock ke1, ke2, ke3, ivec;
memset(ke1, 0, 8);
memset(ke2, 0, 8);
memset(ke2, 0, 8);

if (key.length() >= 24) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, 8);
} else if (key.length() >= 16) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, 8);
memcpy(ke3, key.c_str() + 16, key.length() - 16);
} else if (key.length() >= 8) {
memcpy(ke1, key.c_str(), 8);
memcpy(ke2, key.c_str() + 8, key.length() - 8);
memcpy(ke3, key.c_str(), 8);
} else {
memcpy(ke1, key.c_str(), key.length());
memcpy(ke2, key.c_str(), key.length());
memcpy(ke3, key.c_str(), key.length());
}

DES_key_schedule ks1, ks2, ks3;
DES_set_key_unchecked(&ke1, &ks1);
DES_set_key_unchecked(&ke2, &ks2);
DES_set_key_unchecked(&ke3, &ks3);

memcpy(ivec, cbc_iv, sizeof(cbc_iv));

int iLength = ciphertext.length() % 8 ? (ciphertext.length() / 8 + 1) * 8 : ciphertext.length();
unsigned char* tmp = new unsigned char[iLength];
memset(tmp, 0, iLength);

DES_ede3_cbc_encrypt((const unsigned char*)ciphertext.c_str(), tmp, ciphertext.length()+1, &ks1, &ks2, &ks3, &ivec, DES_DECRYPT);

strClearText = (char*)tmp;

delete [] tmp;
}
break;
}

return strClearText;
}

#include "stdafx.h"
#include "cryptotest.h"
#include <iostream>
#include <string>

using namespace std;

void test_DES()
{
string cleartext = "中国北京12345$abcde%ABCDE@！！！!";
string ciphertext = "";
string key = "beijingchina1234567890ABCDEFGH!!!";

CRYPTO_MODE mode = TRIPLE_CBC;

ciphertext = DES_Encrypt(cleartext, key, mode);
string decrypt = DES_Decrypt(ciphertext, key, mode);

cout<<"src cleartext: "<<cleartext<<endl;
cout<<"genarate ciphertext: "<<ciphertext<<endl;
cout<<"src ciphertext: "<<ciphertext<<endl;
cout<<"genarate cleartext: "<<decrypt<<endl;

if (strcmp(cleartext.c_str(), decrypt.c_str()) == 0)
cout<<"DES crypto ok!!!"<<endl;
else
cout<<"DES crypto error!!!"<<endl;
}

int main(int argc, char* argv[])
{
test_DES();

cout<<"ok!!!"<<endl;

return 0;
}