准备工作

命令行加密解密，用与比对代码中的算法和命令行的算法是否一致

C:\openssl_test>openssl rsautl -encrypt -in data.txt -inkey public.pem -pubin -out data.en

C:\openssl_test>openssl rsautl -decrypt -in data.en -inkey private.pem -out data.de

-pubin表示使用纯公钥加密

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <openssl/bn.h>

#include <openssl/rsa.h>

#include <openssl/pem.h>

#include <openssl/applink.c>

#pragma comment(lib, "libeay32.lib")

#pragma comment(lib, "ssleay32.lib")

int main()

{

	RSA *rsaKey;

	char fData[]="j23ur2jfsf-=20r034ujf";

	char tData[128];

	FILE *fp;

	fp = fopen("C:\\openssl_test\\public.pem", "r");

	int strLen = strlen(fData);

    rsaKey = PEM_read_RSA_PUBKEY(fp, NULL, NULL, NULL);

	int ret = RSA_public_encrypt(strLen, (unsigned char *)fData, (unsigned char*)tData, rsaKey, RSA_PKCS1_PADDING);

	//每次加密出来的tData都不一样，因为填充了随机数

	RSA_free(rsaKey);

	fclose(fp);

	//此段代码用户比对，校验命令行的加密

	//将结果写入文件，生成的文件用命令行解密

	//openssl rsautl -decrypt -in pdata.en -inkey private.pem -out pdata.de

	fp = fopen("C:\\openssl_test\\pdata.en", "wb");

	fwrite(tData , ret, 1 , fp );

	fclose(fp);

	fp = fopen("C:\\openssl_test\\private.pem", "r");

	rsaKey = PEM_read_RSAPrivateKey(fp,NULL,NULL,NULL);

	ret = RSA_private_decrypt(128, (unsigned char *)tData, (unsigned char *)fData, rsaKey, RSA_PKCS1_PADDING);  

	fclose(fp);

	//此段代码用于比对，校验命令行的解密

	//将命令行生成的加密文件读入内存，然后解密

	//openssl rsautl -encrypt -in data.txt -inkey public.pem -pubin -out data.en

	fp = fopen("C:\\openssl_test\\data.en", "rb");

	fread(tData , 128, 1 , fp );

	ret = RSA_private_decrypt(128, (unsigned char *)tData, (unsigned char *)fData, rsaKey, RSA_PKCS1_PADDING);

	fclose(fp);

	RSA_free(rsaKey);

	return 0;

}