用openssl进行rsa的加密与解密（linux,C++版）

//demo.cpp
// g++ demo.cpp -o demo -lcrypto
#include
#include
#include
#include
#include
#include
#include
using namespace std;
//加密
std::string EncodeRSAKeyFile( const std::string& strPemFileName, const std::string& strData )
{
if (strPemFileName.empty() || strData.empty())
{
assert(false);
return "";
}
FILE* hPubKeyFile = fopen(strPemFileName.c_str(), "rb");
if( hPubKeyFile == NULL )
{
assert(false);
return "";
}
std::string strRet;
RSA* pRSAPublicKey = RSA_new();
if(PEM_read_RSA_PUBKEY(hPubKeyFile, &pRSAPublicKey, 0, 0) == NULL)
{
assert(false);
return "";
}
int nLen = RSA_size(pRSAPublicKey);
char* pEncode = new char[nLen + 1];
int ret = RSA_public_encrypt(strData.length(), (const unsigned char*)strData.c_str(), (unsigned char*)pEncode, pRSAPublicKey, RSA_PKCS1_PADDING);
if (ret >= 0)
{
strRet = std::string(pEncode, ret);
}
delete[] pEncode;
RSA_free(pRSAPublicKey);
fclose(hPubKeyFile);
CRYPTO_cleanup_all_ex_data();
return strRet;
}
//解密
std::string DecodeRSAKeyFile( const std::string& strPemFileName, const std::string& strData )
{
if (strPemFileName.empty() || strData.empty())
{
assert(false);
return "";
}
FILE* hPriKeyFile = fopen(strPemFileName.c_str(),"rb");
if( hPriKeyFile == NULL )
{
assert(false);
return "";
}
std::string strRet;
RSA* pRSAPriKey = RSA_new();
if(PEM_read_RSAPrivateKey(hPriKeyFile, &pRSAPriKey, 0, 0) == NULL)
{
assert(false);
return "";
}
int nLen = RSA_size(pRSAPriKey);
char* pDecode = new char[nLen+1];
int ret = RSA_private_decrypt(strData.length(), (const unsigned char*)strData.c_str(), (unsigned char*)pDecode, pRSAPriKey, RSA_PKCS1_PADDING);
if(ret >= 0)
{
strRet = std::string((char*)pDecode, ret);
}
delete [] pDecode;
RSA_free(pRSAPriKey);
fclose(hPriKeyFile);
CRYPTO_cleanup_all_ex_data();
return strRet;
}
int main()
{
//原文
const string One= "skl;dfhas;lkdfhslk;dfhsidfhoiehrfoishfsidf";
cout <<"one: " < //密文（二进制数据）
string two = EncodeRSAKeyFile("pubkey.pem", one);
cout <<"two: " < //顺利的话，解密后的文字和原文是一致的
string three = DecodeRSAKeyFile("prikey.pem", two);
cout <<"three: " < return 0;
}