cryptopp des加密文件_Crypto++入门学习笔记(DES、AES、RSA、SHA-256)
Crypto++是个免费的C++加解密类库,由于资格太老、持续更新,最新版本到了CryptoPP 5.6,对天缘而言,第一眼看到CryptoPP就感觉头大,根目录下放置大量单源文件、编译文件、项目文件,再加上多平台和多编译器支持,文件几乎又多了一倍,而且还是都混到一起,直接就让人望而却步。毕竟Crypto是个功能完整,且经过大量用户使用考验的开源库。所以,皱眉学习汇总一下,遂成此文。
本文测试环境:Windows7 SP1+VC6,测试工程名为Test。用VC打开CryptoPP工程文件,会发现有四个子工程:
cryptdll - 生成cryptopp.dll动态库
dlltest - 用来测试cryptopp.dll,依赖cryptdll工程
cryptlib - 生成cryptlib.lib静态库
cryptest - 用来测试cryptopp,依赖cryptlib工程
所以,我们有两种使用CryptoPP方法,一种是静态链接,还有一种是动态链接,使用对应的工程编译即可,区别就不说了,我们下文以静态链接为例,介绍几种常用加解密算法使用。
一、编译cryptlib
首先需要编译cryptlib,最后得到cryptlib.lib文件。
先在测试工程Test下创建目录cryptopp\lib和cryptopp\include,并把Project Settings-C/C++-Processor下Include目录增加“cryptopp\include”。
把cryptlib.lib拷贝到Test\cryptopp\lib下。
把cryptoPP根目录下所有的*.h文件都拷贝到Test\cryptopp\include下。当然实际上用不了那么多,后续用到哪个include哪个。
下文开始测试使用CryptoPP,实际使用中,如果功能上逻辑上需要修改,可以参考上文测试工程中的示例程序,以及官方文档。下文编译如果报告XX重复定义等错误,请检查LIB库工程和本测试工程的:Project Setting-C/C++-Code Generation User run-time library是否统一。
二、测试cryptlib
1、测试MD5
#define CRYPTOPP_ENABLE_NAMESPACE_WEAK 1
#include "md5.h"
using namespace CryptoPP;
#pragma comment(lib, "cryptopp\\lib\\cryptlib.lib")
using namespace std;
void main() {
byte message[]="HelloWorld!";
byte mres[16];//MD5 128 bits=16bytes
Weak::MD5 md5;
md5.Update(message,11);//strlen=11
md5.Final(mres);
for(int i=0;i<16;i++)
printf("%02X",mres[i]);
printf("\n");
}
2、测试AES
//For AES encrypt
#include "default.h"
#include "cryptlib.h"
#include "filters.h"
#include "bench.h"
#include "osrng.h"
#include "hex.h"
#include "modes.h"
#include "files.h"
using namespace CryptoPP;
#pragma comment(lib, "cryptopp\\lib\\cryptlib.lib")
using namespace std;
void main() {
unsigned char key[]= {0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x01,0x02, 0x03,0x04,0x05,0x06,0x07,0x08};//AES::DEFAULT_KEYLENGTH
unsigned char iv[]= {0x01,0x02,0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x03, 0x01,0x02,0x03,0x03,0x03,0x03};
int keysize = 16;
stringmessage = "Hello World!";
stringstrEncTxt;
stringstrDecTxt;
//CBC - PADDING
//AES-CBC Encrypt(ONE_AND_ZEROS_PADDING)
CBC_Mode::Encryption Encryptor1(key,keysize,iv);
StringSource(message,
true,
new StreamTransformationFilter(Encryptor1,
new StringSink( strEncTxt ),
BlockPaddingSchemeDef::BlockPaddingScheme::ONE_AND_ZEROS_PADDING,
true)
);
//AES-CBC Decrypt
CBC_Mode::Decryption Decryptor1(key,keysize,iv);
StringSource(strEncTxt,
true,
new StreamTransformationFilter( Decryptor1,
new StringSink( strDecTxt ),
BlockPaddingSchemeDef::BlockPaddingScheme::ONE_AND_ZEROS_PADDING,
true)
);
//CTR - NO_PADDING
//AES-CTR Encrypt
CTR_Mode::Encryption Encryptor2(key,keysize,iv);
StringSource(message,
true,
new StreamTransformationFilter( Encryptor2,
new StringSink( strEncTxt ),
BlockPaddingSchemeDef::BlockPaddingScheme::NO_PADDING,
true)
);
//AES-CTR Decrypt
CTR_Mode::Decryption Decryptor2(key,keysize,iv);
StringSource(strEncTxt,
true,
new StreamTransformationFilter( Decryptor2,
new StringSink( strDecTxt ),
BlockPaddingSchemeDef::BlockPaddingScheme::NO_PADDING,
true)
);
}
上文是使用StringSource方式加密字符串,还可以使用FileSource方式直接对文件进行加解密操作。示例如下:
SecByteBlock HexDecodeString(const char *hex) {
StringSource ss(hex, true, new HexDecoder);
SecByteBlock result((size_t)ss.MaxRetrievable());
ss.Get(result, result.size());
return result;
}
void AES_CTR_Encrypt(const char *hexKey, const char *hexIV, const char *infile, const char *outfile) {
SecByteBlock key = HexDecodeString(hexKey);
SecByteBlock iv = HexDecodeString(hexIV);
CTR_Mode::Encryption aes(key, key.size(), iv);
FileSource(infile, true, new StreamTransformationFilter(aes, new FileSink(outfile)));
}
直接调用AES_CTR_Encrypt函数即可,CBC函数需对应修改。
四、使用提示
1、StringSource类定义filters.h
//! zero terminated string as source
StringSource(const char *string, bool pumpAll, BufferedTransformation *attachment = NULL)
: SourceTemplate(attachment) {SourceInitialize(pumpAll, MakeParameters("InputBuffer", ConstByteArrayParameter(string)));}
//! binary byte array as source
StringSource(const byte *string, size_t length, bool pumpAll, BufferedTransformation *attachment = NULL)
: SourceTemplate(attachment) {SourceInitialize(pumpAll, MakeParameters("InputBuffer", ConstByteArrayParameter(string, length)));}
//! std::string as source
StringSource(const std::string &string, bool pumpAll, BufferedTransformation *attachment = NULL)
: SourceTemplate(attachment) {SourceInitialize(pumpAll, MakeParameters("InputBuffer", ConstByteArrayParameter(string)));}
2、RSA有关的加解密、签名函数
更多请参考工程cryptest工程下test.cpp文件内函数
void GenerateRSAKey(unsigned int keyLength, const char *privFilename, const char *pubFilename, const char *seed);
string RSAEncryptString(const char *pubFilename, const char *seed, const char *message);
string RSADecryptString(const char *privFilename, const char *ciphertext);
void RSASignFile(const char *privFilename, const char *messageFilename, const char *signatureFilename);
bool RSAVerifyFile(const char *pubFilename, const char *messageFilename, const char *signatureFilename);