#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <openssl/evp.h>
#include <openssl/x509.h>

//Base64編碼
void tEVP_Encode()
{
	EVP_ENCODE_CTX ctx;				//EVP編碼結(jié)構(gòu)體
	unsigned char in[1024];			//輸入數(shù)據(jù)緩沖區(qū)
	int inl;						//輸入數(shù)據(jù)長度
	char out[2048]={0};				//輸出數(shù)據(jù)緩沖區(qū)
	int outl;						//輸出數(shù)據(jù)長度
	FILE *infp;						//輸入文件句柄
	FILE *outfp;					//輸出文件句柄

	infp = fopen("test.dat","rb");//打開待編碼的文件
	if(infp == NULL)
	{
		printf("Open File \"Test.dat\"  for Read Err.\n");
		return;
	}
	
	outfp = fopen("test.txt","w");//打開編碼后保存的文件
	if(outfp == NULL)
	{
		printf("Open File \"test.txt\" For Write Err.\n");
		return;
	}
	EVP_EncodeInit(&ctx);//Base64編碼初始化
	printf("文件\"Test.dat\" Base64編碼后為：\n");
	//循環(huán)讀取原文，并調(diào)用EVP_EncodeUpdate計算Base64編碼
	while(1)
	{
		inl = fread(in,1,1024,infp);
		if(inl <= 0)
			break;
		EVP_EncodeUpdate(&ctx,out,&outl,in,inl);//編碼
		fwrite(out,1,outl,outfp);//輸出編碼結(jié)果到文件
		printf("%s",out);
	} 
	EVP_EncodeFinal(&ctx,out,&outl);//完成編碼，輸出最后的數(shù)據(jù)。
	fwrite(out,1,outl,outfp);
	printf("%s",out);
	fclose(infp);
	fclose(outfp);	
	printf("對文件\"Test.dat\" Base64編碼完成，保存到\"test.txt\"文件.\n\n\n");
}

//Base64解碼
void tEVP_Decode()
{
	EVP_ENCODE_CTX ctx;				//EVP編碼結(jié)構(gòu)體
	char in[1024];					//輸入數(shù)據(jù)緩沖區(qū)
	int inl;						//輸入數(shù)據(jù)長度
	unsigned char out[1024];		//輸出數(shù)據(jù)緩沖區(qū)
	int outl;						//輸出數(shù)據(jù)長度
	FILE *infp;						//輸入文件句柄
	FILE *outfp;					//輸出文件句柄
	
	infp = fopen("test.txt","r");//打開待解碼的文件
	if(infp == NULL)
	{
		printf("Open File \"Test.txt\"  for Read Err.\n");
		return;
	}
	outfp = fopen("test-1.dat","wb");//打開解碼后保存的文件
	if(outfp == NULL)
	{
		printf("Open File \"test-1.txt\" For Write Err.\n");
		return;
	}
	EVP_DecodeInit(&ctx);//Base64解碼初始化
	printf("開始對文件\"Test.txt\" Base64解碼...\n\n");
	//循環(huán)讀取原文，并調(diào)用EVP_DecodeUpdate進行Base64解碼
	while(1)
	{
		inl = fread(in,1,1024,infp);
		if(inl <= 0)
			break;
		EVP_DecodeUpdate(&ctx,out,&outl,in,inl);//Base64解碼
		fwrite(out,1,outl,outfp);//輸出到文件
	} 
	EVP_DecodeFinal(&ctx,out,&outl);//完成解碼，輸出最后的數(shù)據(jù)。
	fwrite(out,1,outl,outfp);
	fclose(infp);
	fclose(outfp);	
	printf("對文件\"Test.txt\" Base64解碼完成，保存為\"test-1.dat\"\n\n\n");
	
}
 
int main()
{
 
	tEVP_Encode();
	tEVP_Decode();
	
	return 0;
}