学步园

// OpensslTest2.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <string>
#include <openssl/pem.h>
#include <openssl/rsa.h>
//解决错误：OPENSSL_Uplink(0098E000,07): no OPENSSL_Applink 错误分析
//有兴趣的可以去此blog看下：http://blog.csdn.net/ecjtuync/article/details/3278995
extern "C"
{
#include <openssl/applink.c>
}

typedef unsigned char BYTE;
const int RSA_LEN			= 2048;
const int DATA_LEN			= 128;
/*加密最大长度为加密长度-41*/
bool GetPubKey(RSA * pRsa);
bool GetPrivKey(RSA * pRsa);

bool CreateKeys();
bool SavePubKey(RSA *rsaKey);
bool SavePrivKey(RSA *rsaKey);

int RsaEncrypt(int nLen,BYTE * pData,BYTE *pEncrypt,RSA *rsa,int padding = RSA_PKCS1_PADDING);
int RsaDecrypt(int nLen,BYTE * pData,BYTE *pDecrypt,RSA *rsa,int padding = RSA_PKCS1_PADDING);

//加密文件
const char pub_key[]	= "pub.key";
const char priv_key[]	= "priv.key";
RSA* pubRsa = NULL;
RSA *privRsa = NULL;


int _tmain(int argc, _TCHAR* argv[])
{
    // 原始明文
    char plain[256]="测试测试,hello123";
	
    // 用来存放密文
	char encrypted[RSA_LEN] = {0};
	
    // 用来存放解密后的明文
    char decrypted[RSA_LEN] = {0};
	
    // -------------------------------------------------------
    // 利用公钥加密明文的过程
    // -------------------------------------------------------
	//创建keys
	if(!CreateKeys())
	{
		printf("CreateKeys false\n");
		return -1;
	}
	//保存keys
	if(!SavePubKey(pubRsa))
	{
		printf("GetPubKey false\n");
		return -1;
	}
	if(!SavePrivKey(privRsa))
	{
		printf("SavePrivKey false\n");
		return -1;
	}

	//解析keys
	if(!GetPubKey(pubRsa))
	{
		printf("GetPubKey false\n");
		return -1;
	}
	if(!GetPrivKey(privRsa))
	{
		printf("GetPrivKey false\n");
		return -1;
	}
	
	//检测需要加密的数据的长度
    if(strlen(plain)>=RSA_size(pubRsa)-41){
        printf("check input len false\n");
        return -1;
    }

	//加密
	if(RsaEncrypt(DATA_LEN,(BYTE *)plain,(BYTE *)encrypted,pubRsa) < 0)
	{
        printf("RsaEncrypt false\n");
        return -1;
	}
	printf("RsaEncrypt:\n%s\n",encrypted);
	
	//解密
	if(RsaDecrypt(RSA_size(privRsa),(BYTE *)encrypted,(BYTE *)decrypted,privRsa) < 0)
	{
        printf("RsaDecrypt false\n");
        return -1;
	}
	printf("RsaDecrypt:%s\n",decrypted);
	getchar();
	return 0;
}

/*加密最大长度为加密长度-41*/
bool GetPubKey(RSA * pRsa)
{
    // 打开公钥文件
    FILE* pub_fp=fopen(pub_key,"r");
    if(pub_fp==NULL){
        printf("failed to open pub_key file %s!\n", pub_key);
        return false;
    }
	
    // 从文件中读取公钥
	pRsa=PEM_read_RSA_PUBKEY(pub_fp, NULL, NULL, NULL);
	
    fclose(pub_fp);
    if(pubRsa==NULL){
        printf("unable to read public key!\n");
        return false; 
    }

	return true;
}

bool GetPrivKey(RSA * pRsa)
{
	// 打开私钥文件
    FILE* priv_fp=fopen(priv_key,"r");
    if(priv_fp==NULL){
        printf("failed to open priv_key file %s!\n", priv_key);
        return false;
    }
	    // 从文件中读取私钥
	pRsa = PEM_read_RSAPrivateKey(priv_fp, NULL, NULL, NULL);
    fclose(priv_fp);
    if(pRsa==NULL){
        printf("unable to read private key!\n");
        return false; 
    }
	return true;
}
//RSA_public_encrypt(strlen(plain), (unsigned char *)plain, (unsigned char *)encrypted, rsa1, RSA_PKCS1_PADDING);
int RsaEncrypt(int nLen,BYTE * pData,BYTE *pEncrypt,RSA *rsa,int padding)
{
	return RSA_public_encrypt(nLen, pData, pEncrypt, rsa, padding);
}
//RSA_public_encrypt(strlen(plain), (unsigned char *)plain, (unsigned char *)encrypted, rsa1, RSA_PKCS1_PADDING);
int RsaDecrypt(int nLen,BYTE * pData,BYTE *pDecrypt,RSA *rsa,int padding)
{
	return RSA_private_decrypt(nLen, pData, pDecrypt, rsa, padding);
}

bool CreateKeys()
{
	RSA* pRsa = RSA_generate_key( RSA_LEN ,RSA_F4,NULL,NULL);                      //生成RSA密钥
	pubRsa = RSAPublicKey_dup(pRsa);
	privRsa = RSAPrivateKey_dup(pRsa);

	if(pRsa == NULL)
	{
		printf("RSA_generate_key false\n");
		return false;
	}
	if(pubRsa == NULL)
	{
		printf("RSAPublicKey_dup false\n");
		return false;
	}
	if(privRsa == NULL)
	{
		printf("RSAPrivateKey_dup false\n");
		return false;
	}
	return true;
}

bool SavePrivKey(RSA *rsaKey)
{
	FILE *file = NULL;
	file = fopen(priv_key,"wb");
	if(file == NULL)
		return false;
	if(rsaKey == NULL)
		return false;
	
	PEM_write_RSAPrivateKey(file, rsaKey, NULL, NULL, RSA_LEN, NULL, NULL);
	fclose(file);
	return true;
}

bool SavePubKey(RSA *rsaKey)
{
	FILE *file = NULL;
	file = fopen(pub_key,"wb");
	if(file == NULL)
		return false;
	if(rsaKey == NULL)
		return false;
	
	PEM_write_RSAPublicKey(file, rsaKey);
	fclose(file);
	return true;
}