C/C++ Crypto密码库调用的实现方法

Crypto 库是C/C++的加密算法库，这个加密库很流行，基本上涵盖了市面上的各类加密解密算法，以下代码是我在学习是总结的，放到这里用于后期需要时能够快速解决问题。

项目地址：https://www.cryptopp.com/

Sha256加密算法

Sha系列加密算法包括很多，基本上有以下几种格式的加密方式，位数越大加密强度越大，此算法属于单向加密算法与MD5类似但安全性高于MD5。

• SHA-1：生成摘要的性能比MD5略低

• SHA-256：可以生成长度256bit的信息摘要

• SHA-224：可以生成长度224bit的信息摘要

• SHA-384：可以生成长度384bit的信息摘要

• SHA-512：可以生成长度512bit的信息摘要

#include <iostream>
#include <Windows.h>
#include <string>
#include <sha.h>
#include <md5.h>
#include <crc.h>
#include <files.h>
#include <hex.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

// 计算文件的 SHA256 值
string CalSHA256_ByFile(char *pszFileName)
{
string value;
SHA256 sha256;
FileSource(pszFileName, true, new HashFilter(sha256, new HexEncoder(new StringSink(value))));
return value;
}

// 计算数据的 SHA256 值
string CalSHA256_ByMem(PBYTE pData, DWORD dwDataSize)
{
string value;
SHA256 sha256;
StringSource(pData, dwDataSize, true, new HashFilter(sha256, new HexEncoder(new StringSink(value))));
return value;
}

int main(int argc, char * argv[])
{
string src = "hello lyshark";
string dst;

// 单独计算MD5值的使用
MD5 md5;
StringSource(src, true, new HashFilter(md5, new HexEncoder(new StringSink(dst))));
cout << "计算字符串MD5: " << dst << endl;

// 单独计算CRC32值
CRC32 crc32;
StringSource(src, true, new HashFilter(crc32, new HexEncoder(new StringSink(dst))));
cout << "计算字符串CRC32: " << dst << endl;

// 计算一个数组
BYTE pArrayData[] = { 10, 20, 30, 40, 50 };
DWORD dwArraySize = sizeof(pArrayData);

dst.clear();
StringSource(pArrayData, dwArraySize, true, new HashFilter(md5, new HexEncoder(new StringSink(dst))));
cout << "计算数组的MD5: " << dst << endl;

// 直接对文件计算Sha256散列值
string sha = CalSHA256_ByFile("c://BuidIAT.exe");
cout << "文件散列值: " << sha << endl;

// 读入文件到内存后计算
HANDLE hFile = CreateFile(L"c://BuidIAT.exe", GENERIC_READ, FILE_SHARE_READ, NULL,
 OPEN_EXISTING, FILE_ATTRIBUTE_ARCHIVE, NULL);
DWORD dwFileSize = GetFileSize(hFile, NULL);
BYTE *pData = new BYTE[dwFileSize];
ReadFile(hFile, pData, dwFileSize, NULL, NULL);

string sha2 = CalSHA256_ByMem(pData, dwFileSize);
cout << "内存中文件散列值: " << sha2.c_str() << endl;
system("pause");
return 0;
}

AES 加密与解密

AES是对称加密，AES可使用16，24或32字节密钥（分别对应128，192和256位）。 Crypto++ 库缺省的密钥长度是16字节，也就是 AES:: DEFAULT_KEYLENGTH。

对于 ECB 和 CBC 模式，处理的数据必须是块大小的倍数。或者，你可以用 StreamTransformationFilter 围绕这个模式对象，并把它作为一个过滤器对象。StreamTransformationFilter 能够缓存数据到块中并根据需要填充。

#include<cryptlib.h>
#include<osrng.h>
#include<iostream>
#include<files.h>
#include<aes.h>
#include<modes.h>
#include<hex.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

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

cout << "Key 长度: " << AES::DEFAULT_KEYLENGTH << endl;
cout << "最小长度: " << AES::MIN_KEYLENGTH << endl;
cout << "最大长度: " << AES::MAX_KEYLENGTH << endl;
cout << "Block Size: " << AES::BLOCKSIZE << endl;

AutoSeededRandomPool rand;

// 产生一个随机数的密钥
SecByteBlock Key(0x00, AES::DEFAULT_KEYLENGTH);
rand.GenerateBlock(Key, Key.size());

// 产生一个随机的初始向量
SecByteBlock ival(AES::BLOCKSIZE);
rand.GenerateBlock(ival, ival.size());

byte plainText[] = "hello lyshark";
size_t Textlen = std::strlen((char*)plainText) + 1;
cout << "待加密字符串长度: " << Textlen << endl;

// 加密字符串
CFB_Mode<AES>::Encryption cfbEncryption(Key, Key.size(), ival);
cfbEncryption.ProcessData(plainText, plainText, Textlen);

cout << "显示加密后的十六进制数: ";
StringSource strSource1(plainText, Textlen, true, new HexEncoder(new FileSink(cout)));

// 解密字符串 并将数据输出到Cout流上
CFB_Mode<AES>::Decryption cfbDecryption(Key, Key.size(), ival);
cfbDecryption.ProcessData(plainText, plainText, Textlen);
cout << endl << "显示解密后的十六进制数: ";
StringSource strSource2(plainText, Textlen, true, new HexEncoder(new FileSink(cout)));
cout << endl;

system("pause");
return 0;
}

以下代码使用CBC模式加密与解密指定字符串。如果需要针对字符串进行加解密则需要使用以下代码实现.

#include<cryptlib.h>
#include<osrng.h>
#include<iostream>
#include<files.h>
#include<aes.h>
#include<modes.h>
#include<hex.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

int main(int argc, char * argv[])
{
// 开辟空间并将空间赋予初始值0
byte key[CryptoPP::AES::DEFAULT_KEYLENGTH], iv[CryptoPP::AES::BLOCKSIZE];
memset(key, 0x00, CryptoPP::AES::DEFAULT_KEYLENGTH);
memset(iv, 0x00, CryptoPP::AES::BLOCKSIZE);

// 指定需要加密的字符串与
std::string plaintext = "hello lyshark this is palintext";
std::string ciphertext;
std::string decryptedtext;

// 输出加密前字符串长度
std::cout << "加密前字符串长度: " << plaintext.size() << " bytes" << std::endl;
std::cout << plaintext;
std::cout << std::endl << std::endl;

// 创建并开始加密字符串
CryptoPP::AES::Encryption aesEncryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
CryptoPP::CBC_Mode_ExternalCipher::Encryption cbcEncryption(aesEncryption, iv);

CryptoPP::StreamTransformationFilter stfEncryptor(cbcEncryption, new CryptoPP::StringSink(ciphertext));
stfEncryptor.Put(reinterpret_cast<const unsigned char*>(plaintext.c_str()), plaintext.length());
stfEncryptor.MessageEnd();

// 输出密文长度
std::cout << "加密密文长度: " << ciphertext.size() << " bytes" << std::endl;
for (int i = 0; i < ciphertext.size(); i++)
{
 std::cout << "0x" << std::hex << (0xFF & static_cast<byte>(ciphertext[i])) << " ";
}
std::cout << std::endl << std::endl;

// 解密被加密的字符串
CryptoPP::AES::Decryption aesDecryption(key, CryptoPP::AES::DEFAULT_KEYLENGTH);
CryptoPP::CBC_Mode_ExternalCipher::Decryption cbcDecryption(aesDecryption, iv);

CryptoPP::StreamTransformationFilter stfDecryptor(cbcDecryption, new CryptoPP::StringSink(decryptedtext));
stfDecryptor.Put(reinterpret_cast<const unsigned char*>(ciphertext.c_str()), ciphertext.size());
stfDecryptor.MessageEnd();

// 输出解密后的字符串长度
std::cout << "解密后的字符串: " << std::endl;
std::cout << decryptedtext;
std::cout << std::endl << std::endl;

system("pause");
return 0;
}

下面的示例使用CFB模式实现快速对字符串进行加解密,该模式的数据的长度并不需要是AES的块大小的倍数.

#include<cryptlib.h>
#include<osrng.h>
#include<iostream>
#include<files.h>
#include<aes.h>
#include<modes.h>
#include<hex.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

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

// 生成随机Key
SecByteBlock key(0x00, AES::DEFAULT_KEYLENGTH);
rand.GenerateBlock(key, key.size());

// 生成随机IV值
byte iv[AES::BLOCKSIZE];
rand.GenerateBlock(iv, AES::BLOCKSIZE);

// 需要加密的字符串
char plainText[] = "hello lyshark";
int messageLen = (int)strlen(plainText) + 1;

// 执行快速加密
CFB_Mode<AES>::Encryption cfbEncryption(key, key.size(), iv);
cfbEncryption.ProcessData((byte*)plainText, (byte*)plainText, messageLen);
cout << "加密后的数据: " << plainText << endl;

// 执行快速解密
CFB_Mode<AES>::Decryption cfbDecryption(key, key.size(), iv);
cfbDecryption.ProcessData((byte*)plainText, (byte*)plainText, messageLen);
cout << "解密后的数据: " << plainText << endl;

system("pause");
return 0;
}

AES2 加密:

#include<cryptlib.h>
#include<iostream>
#include <Windows.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

// AES加密
BOOL AesEncrypt(BYTE *pPassword, DWORD dwPasswordLength, BYTE *pData, DWORD &dwDataLength, DWORD dwBufferLength)
{
BOOL bRet = TRUE;
HCRYPTPROV hCryptProv = NULL;
HCRYPTHASH hCryptHash = NULL;
HCRYPTKEY hCryptKey = NULL;
do
{
 // 获取CSP句柄
 bRet = CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT);
 if (FALSE == bRet)
  break;

// 创建HASH对象
 bRet = CryptCreateHash(hCryptProv, CALG_MD5, NULL, 0, &hCryptHash);
 if (FALSE == bRet)
  break;

// 对密钥进行HASH计算
 bRet = CryptHashData(hCryptHash, pPassword, dwPasswordLength, 0);
 if (FALSE == bRet)
  break;

// 使用HASH来生成密钥
 bRet = CryptDeriveKey(hCryptProv, CALG_AES_128, hCryptHash, CRYPT_EXPORTABLE, &hCryptKey);
 if (FALSE == bRet)
  break;

// 加密数据
 bRet = CryptEncrypt(hCryptKey, NULL, TRUE, 0, pData, &dwDataLength, dwBufferLength);
 if (FALSE == bRet)
  break;
} while (FALSE);

// 关闭释放
if (hCryptKey)
 CryptDestroyKey(hCryptKey);
if (hCryptHash)
 CryptDestroyHash(hCryptHash);
if (hCryptProv)
 CryptReleaseContext(hCryptProv, 0);
return bRet;
}

// AES解密
BOOL AesDecrypt(BYTE *pPassword, DWORD dwPasswordLength, BYTE *pData, DWORD &dwDataLength, DWORD dwBufferLength)
{
BOOL bRet = TRUE;
HCRYPTPROV hCryptProv = NULL;
HCRYPTHASH hCryptHash = NULL;
HCRYPTKEY hCryptKey = NULL;

do
{
 // 获取CSP句柄
 bRet = ::CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT);
 if (FALSE == bRet)
  break;

// 创建HASH对象
 bRet = CryptCreateHash(hCryptProv, CALG_MD5, NULL, 0, &hCryptHash);
 if (FALSE == bRet)
  break;

// 对密钥进行HASH计算
 bRet = CryptHashData(hCryptHash, pPassword, dwPasswordLength, 0);
 if (FALSE == bRet)
  break;

// 使用HASH来生成密钥
 bRet = CryptDeriveKey(hCryptProv, CALG_AES_128, hCryptHash, CRYPT_EXPORTABLE, &hCryptKey);
 if (FALSE == bRet)
  break;

// 解密数据
 bRet = CryptDecrypt(hCryptKey, NULL, TRUE, 0, pData, &dwDataLength);
 if (FALSE == bRet)
  break;
} while (FALSE);

// 关闭释放
if (hCryptKey)
 CryptDestroyKey(hCryptKey);
if (hCryptHash)
 CryptDestroyHash(hCryptHash);
if (hCryptProv)
 CryptReleaseContext(hCryptProv, 0);
return bRet;
}

int main(int argc, char * argv[])
{
BYTE pData[MAX_PATH] = { 0 };
DWORD dwDataLength = 0, dwBufferLength = MAX_PATH;

lstrcpy((char *)pData, "hello lyshark");
dwDataLength = 1 + lstrlen((char *)pData);

// 原始十六进制数据
printf("AES 原始数据 [％d]: ", dwDataLength);
for (int i = 0; i < dwDataLength; i++)
{
 printf("％02x ", pData[i]);
}
printf("\n\n");

// AES 加密
AesEncrypt((BYTE *)"AAAVCDERFGTYHUJI", 16, pData, dwDataLength, dwBufferLength);
printf("AES 加密后 [％d]: ", dwDataLength);
for (int i = 0; i < dwDataLength; i++)
{
 printf("％02x ", pData[i]);
}
printf("\n\n");

// AES 解密
AesDecrypt((BYTE *)"AAAVCDERFGTYHUJI", 16, pData, dwDataLength, dwBufferLength);
printf("AES 解密后 [％d]: ", dwDataLength);
for (int i = 0; i < dwDataLength; i++)
{
 printf("％02x ", pData[i]);
}
system("pause");
return 0;
}

Base64加解密:

#include<cryptlib.h>
#include<osrng.h>
#include<iostream>
#include <Windows.h>
#include<files.h>
#include<base64.h>
#include<modes.h>
#include<hex.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

void DisplayHex(BYTE *pData, DWORD dwSize)
{
for (int i = 0; i < dwSize; i++)
{
 if ((0 != i) && (0 == i ％ 16))
  printf("\n");
 else if ((0 != i) && (0 == i ％ 8))
  printf(" ");
 printf("％02X ", pData[i]);
}
printf("\n");
}

int main(int argc, char * argv[])
{
unsigned char plainText[] = "hello lyshark";

// 对字符串编码
string encoded;
Base64Encoder encoder;
encoder.Put(plainText, sizeof(plainText));
encoder.MessageEnd();

word64 size = encoder.MaxRetrievable();
if (size)
{
 encoded.resize(size);
 encoder.Get((byte *)&encoded[0], encoded.size());
}
cout << "编码后的数据: " << encoded << endl;

// 对字符串解码
string decoded;
Base64Decoder decoder;
decoder.Put((byte *)encoded.data(), encoded.size());
decoder.MessageEnd();

size = decoder.MaxRetrievable();
if (size && size <= SIZE_MAX)
{
 decoded.resize(size);
 decoder.Get((byte *)&decoded[0], decoded.size());
}
cout << "对字符串解码: " << decoded;

// 输出解码字符串的十六进制格式
char szOriginalData[] = "hello lyshark";

cout << "字符串十六进制格式: ";
DisplayHex((BYTE *)szOriginalData, (1 + lstrlen(szOriginalData)));

system("pause");
return 0;
}

Hash加密算法

使用hash算法计算特定文件的Hash值.

#include<cryptlib.h>
#include<iostream>
#include <Windows.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

BOOL GetFileData(char *pszFilePath, BYTE **ppFileData, DWORD *pdwFileDataLength)
{
BOOL bRet = TRUE;
BYTE *pFileData = NULL;
DWORD dwFileDataLength = 0;
HANDLE hFile = NULL;
DWORD dwTemp = 0;

do
{
 hFile = CreateFile(pszFilePath, GENERIC_READ | GENERIC_WRITE,FILE_SHARE_READ |
  FILE_SHARE_WRITE, NULL, OPEN_EXISTING,FILE_ATTRIBUTE_ARCHIVE, NULL);
 if (INVALID_HANDLE_VALUE == hFile)
 {
  bRet = FALSE;
  break;
 }

dwFileDataLength = ::GetFileSize(hFile, NULL);
 pFileData = new BYTE[dwFileDataLength];
 if (NULL == pFileData)
 {
  bRet = FALSE;
  break;
 }
 RtlZeroMemory(pFileData, dwFileDataLength);
 ReadFile(hFile, pFileData, dwFileDataLength, &dwTemp, NULL);

// 返回
 *ppFileData = pFileData;
 *pdwFileDataLength = dwFileDataLength;
} while (FALSE);

if (hFile)
 CloseHandle(hFile);
return bRet;
}

BOOL CalculateHash(BYTE *pData, DWORD dwDataLength, ALG_ID algHashType,
BYTE **ppHashData, DWORD *pdwHashDataLength)
{
HCRYPTPROV hCryptProv = NULL;
HCRYPTHASH hCryptHash = NULL;
BYTE *pHashData = NULL;
DWORD dwHashDataLength = 0;
DWORD dwTemp = 0;
BOOL bRet = FALSE;

do
{
 // 获得指定CSP的密钥容器的句柄
 bRet = CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT);
 if (FALSE == bRet)
  break;

// 创建一个HASH对象, 指定HASH算法
 bRet = CryptCreateHash(hCryptProv, algHashType, NULL, NULL, &hCryptHash);
 if (FALSE == bRet)
  break;

// 计算HASH数据
 bRet = ::CryptHashData(hCryptHash, pData, dwDataLength, 0);
 if (FALSE == bRet)
  break;

// 获取HASH结果的大小
 dwTemp = sizeof(dwHashDataLength);
 bRet = ::CryptGetHashParam(hCryptHash, HP_HASHSIZE, (BYTE *)(&dwHashDataLength), &dwTemp, 0);
 if (FALSE == bRet)
  break;

// 申请内存
 pHashData = new BYTE[dwHashDataLength];
 if (NULL == pHashData)
 {
  bRet = FALSE;
  break;
 }
 RtlZeroMemory(pHashData, dwHashDataLength);

// 获取HASH结果数据
 bRet = CryptGetHashParam(hCryptHash, HP_HASHVAL, pHashData, &dwHashDataLength, 0);
 if (FALSE == bRet)
  break;

// 返回数据
 *ppHashData = pHashData;
 *pdwHashDataLength = dwHashDataLength;

} while (FALSE);

// 释放关闭
if (FALSE == bRet)
{
 if (pHashData)
 {
  delete[]pHashData;
  pHashData = NULL;
 }
}
if (hCryptHash)
 CryptDestroyHash(hCryptHash);
if (hCryptProv)
 CryptReleaseContext(hCryptProv, 0);
return bRet;
}

int main(int argc, char * argv[])
{
BYTE *pData = NULL;
DWORD dwDataLength = 0;
BYTE *pHashData = NULL;
DWORD dwHashDataLength = 0;

// 获取文件流数据
GetFileData("c://BuidIAT.exe", &pData, &dwDataLength);

// 计算 MD5
CalculateHash(pData, dwDataLength, CALG_MD5, &pHashData, &dwHashDataLength);
printf("MD5 Hash -> ");
for (int i = 0; i < dwHashDataLength; i++)
 printf("％x", pHashData[i]);
printf("\n\n", dwHashDataLength);
if (pHashData)
{
 delete[]pHashData;
 pHashData = NULL;
}

// 计算 SHA1
CalculateHash(pData, dwDataLength, CALG_SHA1, &pHashData, &dwHashDataLength);
printf("SHA1 -> ");
for (int i = 0; i < dwHashDataLength; i++)
 printf("％x", pHashData[i]);
printf("\n\n", dwHashDataLength);
if (pHashData)
{
 delete[]pHashData;
 pHashData = NULL;
}

// 计算 SHA256
CalculateHash(pData, dwDataLength, CALG_SHA_256, &pHashData, &dwHashDataLength);
printf("SHA256 -> ");
for (int i = 0; i < dwHashDataLength; i++)
 printf("％x", pHashData[i]);
printf("\n\n", dwHashDataLength);
if (pHashData)
{
 delete[]pHashData;
 pHashData = NULL;
}
system("pause");
return 0;
}

RSA加密算法

RSA算法包括公钥与私钥两部,加密时会先使用RSA生成公钥与私钥,然后在进行加密.

#include<iostream>
#include <Windows.h>

using namespace std;

// 生成公钥和私钥
BOOL GenerateKey(BYTE **ppPublicKey, DWORD *pdwPublicKeyLength, BYTE **ppPrivateKey, DWORD *pdwPrivateKeyLength)
{
BOOL bRet = TRUE;
HCRYPTPROV hCryptProv = NULL;
HCRYPTKEY hCryptKey = NULL;
BYTE *pPublicKey = NULL;
DWORD dwPublicKeyLength = 0;
BYTE *pPrivateKey = NULL;
DWORD dwPrivateKeyLength = 0;

do
{
 // 获取CSP句柄
 bRet = CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, 0);
 if (FALSE == bRet)
  break;

// 生成公私密钥对
 bRet = CryptGenKey(hCryptProv, AT_KEYEXCHANGE, CRYPT_EXPORTABLE, &hCryptKey);
 if (FALSE == bRet)
  break;

// 获取公钥密钥的长度和内容
 bRet = CryptExportKey(hCryptKey, NULL, PUBLICKEYBLOB, 0, NULL, &dwPublicKeyLength);
 if (FALSE == bRet)
  break;

pPublicKey = new BYTE[dwPublicKeyLength];
 RtlZeroMemory(pPublicKey, dwPublicKeyLength);
 bRet = CryptExportKey(hCryptKey, NULL, PUBLICKEYBLOB, 0, pPublicKey, &dwPublicKeyLength);
 if (FALSE == bRet)
  break;

// 获取私钥密钥的长度和内容
 bRet = CryptExportKey(hCryptKey, NULL, PRIVATEKEYBLOB, 0, NULL, &dwPrivateKeyLength);
 if (FALSE == bRet)
  break;

pPrivateKey = new BYTE[dwPrivateKeyLength];
 RtlZeroMemory(pPrivateKey, dwPrivateKeyLength);
 bRet = CryptExportKey(hCryptKey, NULL, PRIVATEKEYBLOB, 0, pPrivateKey, &dwPrivateKeyLength);
 if (FALSE == bRet)
  break;

// 返回数据
 *ppPublicKey = pPublicKey;
 *pdwPublicKeyLength = dwPublicKeyLength;
 *ppPrivateKey = pPrivateKey;
 *pdwPrivateKeyLength = dwPrivateKeyLength;

} while (FALSE);

// 释放关闭
if (hCryptKey)
 CryptDestroyKey(hCryptKey);
if (hCryptProv)
 CryptReleaseContext(hCryptProv, 0);
return bRet;
}

// 公钥加密数据
BOOL RsaEncrypt(BYTE *pPublicKey, DWORD dwPublicKeyLength, BYTE *pData, DWORD &dwDataLength, DWORD dwBufferLength)
{
BOOL bRet = TRUE;
HCRYPTPROV hCryptProv = NULL;
HCRYPTKEY hCryptKey = NULL;

do
{
 // 获取CSP句柄
 bRet = CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, 0);
 if (FALSE == bRet)
  break;

// 导入公钥
 bRet = CryptImportKey(hCryptProv, pPublicKey, dwPublicKeyLength, NULL, 0, &hCryptKey);
 if (FALSE == bRet)
  break;

// 加密数据
 bRet = CryptEncrypt(hCryptKey, NULL, TRUE, 0, pData, &dwDataLength, dwBufferLength);
 if (FALSE == bRet)
  break;
} while (FALSE);

// 释放并关闭
if (hCryptKey)
 CryptDestroyKey(hCryptKey);
if (hCryptProv)
 CryptReleaseContext(hCryptProv, 0);
return bRet;
}

// 私钥解密数据
BOOL RsaDecrypt(BYTE *pPrivateKey, DWORD dwProvateKeyLength, BYTE *pData, DWORD &dwDataLength)
{
BOOL bRet = TRUE;
HCRYPTPROV hCryptProv = NULL;
HCRYPTKEY hCryptKey = NULL;

do
{
 // 获取CSP句柄
 bRet = CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, 0);
 if (FALSE == bRet)
  break;

// 导入私钥
 bRet = CryptImportKey(hCryptProv, pPrivateKey, dwProvateKeyLength, NULL, 0, &hCryptKey);
 if (FALSE == bRet)
  break;

// 解密数据
 bRet = CryptDecrypt(hCryptKey, NULL, TRUE, 0, pData, &dwDataLength);
 if (FALSE == bRet)
  break;
} while (FALSE);

// 释放并关闭
if (hCryptKey)
 CryptDestroyKey(hCryptKey);
if (hCryptProv)
 CryptReleaseContext(hCryptProv, 0);
return bRet;
}

int main(int argc, char * argv[])
{
BYTE *pPublicKey = NULL;
DWORD dwPublicKeyLength = 0;
BYTE *pPrivateKey = NULL;
DWORD dwPrivateKeyLength = 0;
BYTE *pData = NULL;
DWORD dwDataLength = 0;
DWORD dwBufferLength = 4096;

pData = new BYTE[dwBufferLength];

RtlZeroMemory(pData, dwBufferLength);
lstrcpy((char *)pData, "hello lyshark");
dwDataLength = 1 + lstrlen((char *)pData);

// 输出加密前原始数据
printf("加密前原始数据: ");
for (int i = 0; i < dwDataLength; i++)
 printf("％x", pData[i]);
printf("\n\n");

// 生成公钥和私钥
GenerateKey(&pPublicKey, &dwPublicKeyLength, &pPrivateKey, &dwPrivateKeyLength);
printf("公钥: ");
for (int i = 0; i < dwPublicKeyLength; i++)
 printf("％.2x", pPublicKey[i]);
printf("\n\n");

printf("私钥: ");
for (int i = 0; i < dwPrivateKeyLength; i++)
 printf("％.2x", pPrivateKey[i]);
printf("\n\n");

// 使用公钥加密
RsaEncrypt(pPublicKey, dwPublicKeyLength, pData, dwDataLength, dwBufferLength);
printf("公钥加密: ");
for (int i = 0; i < dwDataLength; i++)
 printf("％x", pData[i]);
printf("\n\n");

// 使用私钥解密
RsaDecrypt(pPrivateKey, dwPrivateKeyLength, pData, dwDataLength);
printf("私钥解密: ");
for (int i = 0; i < dwDataLength; i++)
 printf("％x", pData[i]);
printf("\n\n");

delete[]pData;
delete[]pPrivateKey;
delete[]pPublicKey;

system("pause");
return 0;
}

Crypt库实现RSA加密

RSA加密一般使用公钥加密私钥解密,先生成公钥与私钥,然后使用这两份密钥对字符串等数据进行操作.

#include<cryptlib.h>
#include<osrng.h>
#include<iostream>
#include<files.h>
#include <Windows.h>
#include <rsa.h>
#include <hex.h>
#include<modes.h>

#pragma comment(lib, "cryptlib.lib")
using namespace std;
using namespace CryptoPP;

// 定义全局随机数池
RandomPool & GlobalRNG();
RandomPool & GlobalRNG()
{
static RandomPool randomPool;
return randomPool;
}

// 生成RSA密钥对
BOOL GenerateRSAKey(DWORD dwRSAKeyLength, char *pszPrivateKeyFileName, char *pszPublicKeyFileName, BYTE *pSeed, DWORD dwSeedLength)
{
RandomPool randPool;
randPool.Put(pSeed, dwSeedLength);

// 生成RSA私钥
RSAES_OAEP_SHA_Decryptor priv(randPool, dwRSAKeyLength);
HexEncoder privFile(new FileSink(pszPrivateKeyFileName)); // 打开文件实行序列化操作

priv.DEREncode(privFile);
privFile.MessageEnd();

// 生成RSA公钥
RSAES_OAEP_SHA_Encryptor pub(priv);
HexEncoder pubFile(new FileSink(pszPublicKeyFileName));  // 打开文件实行序列化操作

pub.DEREncode(pubFile);          // 写密码对象pub到文件对象pubFile里
pubFile.MessageEnd();
return TRUE;
}

/* 此处的加密算法是通过文件中的公钥与私钥进行加密的*/
// RSA加密字符串
string RSA_Encrypt_ByFile(char *pszOriginaString, char *pszPublicKeyFileName, BYTE *pSeed, DWORD dwSeedLength)
{
RandomPool randPool;
randPool.Put(pSeed, dwSeedLength);

FileSource pubFile(pszPublicKeyFileName, TRUE, new HexDecoder);
RSAES_OAEP_SHA_Encryptor pub(pubFile);

// 加密
string strEncryptString;
StringSource(pszOriginaString, TRUE, new PK_EncryptorFilter(randPool, pub, new HexEncoder(new StringSink(strEncryptString))));
return strEncryptString;
}
// RSA解密字符串
string RSA_Decrypt_ByFile(char *pszEncryptString, char *pszPrivateKeyFileName)
{
FileSource privFile(pszPrivateKeyFileName, TRUE, new HexDecoder);
RSAES_OAEP_SHA_Decryptor priv(privFile);

string strDecryptString;
StringSource(pszEncryptString, TRUE, new HexDecoder(new PK_DecryptorFilter(GlobalRNG(), priv, new StringSink(strDecryptString))));
return strDecryptString;
}

/* 通过在内存中的密钥对进行加密与解密 */
// RSA加密字符串
string RSA_Encrypt_ByMem(char *pszOriginaString, char *pszMemPublicKey, BYTE *pSeed, DWORD dwSeedLength)
{
RandomPool randPool;
randPool.Put(pSeed, dwSeedLength);

StringSource pubStr(pszMemPublicKey, TRUE, new HexDecoder);
RSAES_OAEP_SHA_Encryptor pub(pubStr);

// 加密
string strEncryptString;
StringSource(pszOriginaString, TRUE, new PK_EncryptorFilter(randPool, pub, new HexEncoder(new StringSink(strEncryptString))));
return strEncryptString;
}
// RSA解密字符串
string RSA_Decrypt_ByMem(char *pszEncryptString, char *pszMemPrivateKey)
{
StringSource privStr(pszMemPrivateKey, TRUE, new HexDecoder);
RSAES_OAEP_SHA_Decryptor priv(privStr);

string strDecryptString;
StringSource(pszEncryptString, TRUE, new HexDecoder(new PK_DecryptorFilter(GlobalRNG(), priv, new StringSink(strDecryptString))));
return strDecryptString;
}

int main(int argc, char * argv[])
{
// 指定公钥与私钥所在文件目录
char szPrivateFile[] = "c://private.key";
char szPublicFile[] = "c://public.key";

// 指定一串随机数种子
char szSeed[] = "ABCDESGHETYSQDGH";

// 以下就是待加密的字符串
char szOriginalString[] = "hello lyshark";

/* 此处是从文件中读取出公钥与私钥对特定字符串进行加密与解密 */
// 生成RSA公私密钥对
GenerateRSAKey(1024, szPrivateFile, szPublicFile, (BYTE *)szSeed, lstrlen(szSeed));

// RSA公钥加密字符串
string strEncryptString = RSA_Encrypt_ByFile(szOriginalString, szPublicFile, (BYTE *)szSeed, lstrlen(szSeed));

// RSA私钥解密字符串
string strDecryptString = RSA_Decrypt_ByFile((char *)strEncryptString.c_str(), szPrivateFile);

// 显示
printf("原文字符串:\t[％d]％s\n", lstrlen(szOriginalString), szOriginalString);
printf("密文字符串:\t[％d]％s\n", strEncryptString.length(), strEncryptString.c_str());
printf("明文字符串:\t[％d]％s\n", strDecryptString.length(), strDecryptString.c_str());
printf("\n\n");

// --------------------------------------------------------------------------------------------------------------
/* 此处是在内存中对指定字符串进行解密*/
char g_szPubKey[] = "填充公钥";
char g_szPrivKey[] = "填充私钥";

// RSA公钥加密字符串
string strEncryptString_Mem = RSA_Encrypt_ByMem(szOriginalString, g_szPubKey, (BYTE *)szSeed, ::lstrlen(szSeed));
// RSA私钥解密字符串
string strDecryptString_Mem = RSA_Decrypt_ByMem((char *)strEncryptString_Mem.c_str(), g_szPrivKey);
// 显示
printf("原文字符串:\n[％d]％s\n", ::lstrlen(szOriginalString), szOriginalString);
printf("密文字符串:\n[％d]％s\n", strEncryptString_Mem.length(), strEncryptString_Mem.c_str());
printf("明文字符串:\n[％d]％s\n", strDecryptString_Mem.length(), strDecryptString_Mem.c_str());
system("pause");
return 0;

来源：https://blog.csdn.net/qq_29186859/article/details/118345549