OpenSSL中对称加密算法DES常用函数使用举例

主要包括3个文件：

1. cryptotest.h:

#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_

2. destest.cpp:

#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;
}

3. main.cpp:

#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;elsecout<<"DES crypto error!!!"<<endl;
}int main(int argc, char* argv[])
{test_DES();cout<<"ok!!!"<<endl;return 0;
}

GitHub： https://github.com/fengbingchun/OpenSSL_Test