Cryptopp进行RSA加密解密

因最近工作需要，要与一个java服务器进行部分数据交互，其中用户名、密码的加密方式为RSA非对称加密，故研究了一下使用Cryptopp库进行RSA的公钥加密。

搜索了很多资料，其中觉得十分有用的一句话是：

客户端使用RSA加密通常要跟服务器端进行交互，服务器端多为java、.net等编写，在java和.net语言中的RSA加密算法通常使用的是PKCS标准进行加密解密，而cryptopp的实例程序中使用的是SHA1标准，所以如果要跟java的RSA加密算法可以互相解密密文，则cryptopp中也需要以PKCS标准进行加密解密，具体方法是将RSAES_OAEP_SHA_Decryptor/RSAES_OAEP_SHA_Encryptor替换为RSAES_PKCS1v15_Decryptor/RSAES_PKCS1v15_Encryptor

废话不多说，下面是我最终使用的代码：

首先需要知道base64的公钥，保存为rsa-base64-public.key放到程序根目录下。

下面就是从.key文件读取公钥，进而对字符串进行RSA加密，以及转base64的过程：

#include <hex.h>
#include <oids.h>
#include <assert.h>
#include <pkcspad.h>
#include <randpool.h>#include <rsa.h>
using CryptoPP::RSA;
using CryptoPP::InvertibleRSAFunction;
using CryptoPP::RSAES_OAEP_SHA_Encryptor;
using CryptoPP::RSAES_PKCS1v15_Encryptor;
using CryptoPP::RSAES_OAEP_SHA_Decryptor;#include "sha.h"
using CryptoPP::SHA1;#include <filters.h>
using CryptoPP::StringSink;
using CryptoPP::StringSource;
using CryptoPP::PK_EncryptorFilter;
using CryptoPP::PK_DecryptorFilter;#include <files.h>
using CryptoPP::FileSink;
using CryptoPP::FileSource;#include <osrng.h>
using CryptoPP::AutoSeededRandomPool;#include "SecBlock.h"
using CryptoPP::SecByteBlock;#include "cryptlib.h"
using CryptoPP::Exception;
using CryptoPP::DecodingResult;
using CryptoPP::PrivateKey;
using CryptoPP::PublicKey;
using CryptoPP::BufferedTransformation;#include <string>
using std::string;#include <stdexcept>
using std::runtime_error;#include <exception>
using std::exception;#include <iostream>
using std::cout;
using std::cerr;
using std::endl;#include <queue.h>
using CryptoPP::ByteQueue;#include <integer.h>
using CryptoPP::Integer;#include <base64.h>
using CryptoPP::Base64Encoder;
using CryptoPP::Base64Decoder;void Load(const string& filename, BufferedTransformation& bt)
{FileSource file(filename.c_str(), true /*pumpAll*/);file.TransferTo(bt);bt.MessageEnd();
}void LoadBase64(const string& filename, BufferedTransformation& bt)
{Base64Decoder decoder;Load(filename,decoder);decoder.CopyTo(bt);bt.MessageEnd();
}void LoadBase64PublicKey(const string& filename, PublicKey& key)
{ByteQueue queue;LoadBase64(filename, queue);key.Load(queue);
}QString LoginDlg::getRSAString(const QString &orgStr)
{RSA::PublicKey  public_Key;LoadBase64PublicKey("rsa-base64-public.key", public_Key);string text = orgStr.toStdString();string encrypted_text;// 创建随机数生成器AutoSeededRandomPool rng;// 创建加密器RSAES_OAEP_SHA_Encryptor                        encryptor1(public_Key);RSAES_PKCS1v15_Encryptor                        encryptor2(public_Key);CryptoPP::RSAES<CryptoPP::PKCS1v15>::Encryptor  encryptor3(public_Key);// 加密文本| 上面有三种，下面使用第二种与java对接OK！std::string cipherText;StringSource ss(text, true,new PK_EncryptorFilter(rng, encryptor2,new StringSink(cipherText)));// 输出加密后的文本（Base64 编码）std::string encoded;StringSource ss2(cipherText, true,new Base64Encoder(new StringSink(encoded)));QString base64Str = QString::fromStdString(encoded).remove("\n");return base64Str;
}

下面是更多封装的版本：

#include <hex.h>
#include <oids.h>
#include <assert.h>
#include <pkcspad.h>
#include <randpool.h>#include <rsa.h>
using CryptoPP::RSA;
using CryptoPP::InvertibleRSAFunction;
using CryptoPP::RSAES_OAEP_SHA_Encryptor;
using CryptoPP::RSAES_PKCS1v15_Encryptor;
using CryptoPP::RSAES_OAEP_SHA_Decryptor;#include "sha.h"
using CryptoPP::SHA1;#include <filters.h>
using CryptoPP::StringSink;
using CryptoPP::StringSource;
using CryptoPP::PK_EncryptorFilter;
using CryptoPP::PK_DecryptorFilter;#include <files.h>
using CryptoPP::FileSink;
using CryptoPP::FileSource;#include <osrng.h>
using CryptoPP::AutoSeededRandomPool;#include "SecBlock.h"
using CryptoPP::SecByteBlock;#include "cryptlib.h"
using CryptoPP::Exception;
using CryptoPP::DecodingResult;
using CryptoPP::PrivateKey;
using CryptoPP::PublicKey;
using CryptoPP::BufferedTransformation;#include <string>
using std::string;#include <stdexcept>
using std::runtime_error;#include <exception>
using std::exception;#include <iostream>
using std::cout;
using std::cerr;
using std::endl;#include <queue.h>
using CryptoPP::ByteQueue;#include <integer.h>
using CryptoPP::Integer;#include <base64.h>
using CryptoPP::Base64Encoder;
using CryptoPP::Base64Decoder;//保存公钥和私钥
void SavePrivateKey(const string& filename, const PrivateKey& key);
void SavePublicKey(const string& filename, const PublicKey& key);//base64编码
void SaveBase64PrivateKey(const string& filename, const PrivateKey& key);
void SaveBase64PublicKey(const string& filename, const PublicKey& key);//保存
void Save(const string& filename, const BufferedTransformation& bt);
void SaveBase64(const string& filename, const BufferedTransformation& bt);//读取key
void LoadPrivateKey(const string& filename, PrivateKey& key);
void LoadPublicKey(const string& filename, PublicKey& key);void LoadBase64PrivateKey(const string& filename, PrivateKey& key);
void LoadBase64PublicKey(const string& filename, PublicKey& key);void LoadBase64(const string& filename, BufferedTransformation& bt);
void Load(const string& filename, BufferedTransformation& bt);int main(int argc, char* argv[])
{try{// 生成私钥和公钥 AutoSeededRandomPool rng;InvertibleRSAFunction parameters;parameters.GenerateRandomWithKeySize( rng, 1024 ); //生成1024bit密钥，即n=128byteconst Integer& n = parameters.GetModulus();const Integer& p = parameters.GetPrime1();const Integer& q = parameters.GetPrime2();const Integer& d = parameters.GetPrivateExponent();const Integer& e = parameters.GetPublicExponent();cout << "RSA Parameters:" << endl;cout << " n: " << std::hex << n << endl;    //n=p*qcout << " p: " << std::hex << p << endl;    //pcout << " q: " << std::hex << q << endl;    //qcout << " d: " << std::hex << d << endl;    cout << " e: " << std::hex << e << endl;    //e默认是17,原因不明cout << endl; //生成公钥和私钥RSA::PrivateKey privateKey( parameters );//私钥用于加密(n,d)RSA::PublicKey  publicKey( parameters ); //公钥用于解密(n,e)//默认使用ASN.1 DER编码//SavePrivateKey("rsa-private.key", privateKey);//SavePublicKey("rsa-public.key", publicKey);//输出privateKey//ByteQueue queue;//privateKey.Save(queue);//保存private_key到char[]中，//注意char[]长度要足够//注意这里privateKey不仅包括n和d//是使用ASN.1 DER编码的字符数组//char private_key_der_string[1024];//size_t size = queue.MaxRetrievable();//queue.Get((byte*)private_key_der_string,size);//for(int i=0;i<1024;i++)//  cout << std::hex << ((int)private_key_der_string[i]&0xff) << " ";//保存private_key到string中，//注意要预留string size//string private_key_der_string;//size_t size = queue.MaxRetrievable();//if(size)//{//  private_key_der_string.resize(size);        //  queue.Get((byte*)private_key_der_string.data(), //              private_key_der_string.size());//} //for(auto it = private_key_der_string.begin();//      it!=private_key_der_string.end(); it++)//  cout<< std::hex << (*it & 0xff);     //16进制输出char自动转int，需要截断字节//cout << endl << endl;//StringSource参数：(原始字符串, 长度, 变换方式filter)//使用filter将char[]转存为base64编码//string bs64_private_key;//StringSource ss(private_key_der_string, true,//  new Base64Encoder(  //base64编码器//      new StringSink(bs64_private_key)    //保存到bs64_private_key//      ) //  ); //cout << bs64_private_key << endl;//保存base64 key到文件SaveBase64PrivateKey("rsa-base64-private.key", privateKey);SaveBase64PublicKey("rsa-base64-public.key", publicKey);////=================分割线=======================//////读取bs64保存的privateKey和publicKey//RSA::PrivateKey private_Key;RSA::PublicKey  public_Key;//LoadBase64PrivateKey("rsa-base64-private.key", private_Key);LoadBase64PublicKey("rsa-base64-public.key", public_Key);string text= "你好世界", encrypted_text, decrypted_text; // 公钥加密 // 这里为了验证有效性// 直接使用生成的publicKeyRSAES_OAEP_SHA_Encryptor encryptor( public_Key );StringSource( text, true,new PK_EncryptorFilter( rng, encryptor,new StringSink( encrypted_text )) ); // 私钥解密 RSAES_OAEP_SHA_Decryptor decryptor( privateKey );StringSource( encrypted_text, true,new PK_DecryptorFilter( rng, decryptor,new StringSink( decrypted_text ))); cout << decrypted_text << endl;//assert( text == decrypted_text );}catch( CryptoPP::Exception& e ){cerr << "Caught Exception..." << endl;cerr << e.what() << endl;}system("pause");return 0;
}void Save(const string& filename, const BufferedTransformation& bt)
{FileSink file(filename.c_str());bt.CopyTo(file);file.MessageEnd();
}void SaveBase64(const string& filename, const BufferedTransformation& bt)
{Base64Encoder encoder;bt.CopyTo(encoder);encoder.MessageEnd();Save(filename, encoder);
}void SavePrivateKey(const string& filename, const PrivateKey& key)
{ByteQueue queue;key.Save(queue);Save(filename, queue);
}void SavePublicKey(const string& filename, const PublicKey& key)
{ByteQueue queue;key.Save(queue);Save(filename, queue);
}void SaveBase64PrivateKey(const string& filename, const PrivateKey& key)
{ByteQueue queue;key.Save(queue);SaveBase64(filename, queue);
}void SaveBase64PublicKey(const string& filename, const PublicKey& key)
{ByteQueue queue;key.Save(queue);SaveBase64(filename, queue);
}void LoadPrivateKey(const string& filename, PrivateKey& key)
{ByteQueue queue;Load(filename, queue);key.Load(queue);    
}void LoadPublicKey(const string& filename, PublicKey& key)
{ByteQueue queue;Load(filename, queue);key.Load(queue);    
}void Load(const string& filename, BufferedTransformation& bt)
{FileSource file(filename.c_str(), true /*pumpAll*/);file.TransferTo(bt);bt.MessageEnd();
}void LoadBase64(const string& filename, BufferedTransformation& bt)
{Base64Decoder decoder;Load(filename,decoder);decoder.CopyTo(bt);bt.MessageEnd();
}void LoadBase64PrivateKey(const string& filename, PrivateKey& key)
{ByteQueue queue;LoadBase64(filename, queue);key.Load(queue);    
}void LoadBase64PublicKey(const string& filename, PublicKey& key)
{ByteQueue queue;LoadBase64(filename, queue);key.Load(queue);    
}

在此做一个记录，方便日后自己查找，以及希望能够帮助大家！

Cryptopp库可以通过我的CSDN下载进行下载，同时也有另一篇文章介绍MD5的相关操作！

Qt使用Cryptopp生成HMAC-MD5_cryptopp md5-CSDN博客