Base64解码，编码

//
//
//  CrossAppx
//
//  Created by kevin on 15-1-29.
//  Copyright (c) 2014 http://9miao.com All rights reserved.
//
#pragma once
#include "CrossApp.h"
#include <iostream>
#include <stdio.h>
#include <string>

using namespace std;

class MyBase64
{
public:
	MyBase64(void);
	~MyBase64(void);

	static inline bool is_Base64(unsigned char c) {
		return (isalnum(c) || (c == '+') || (c == '/'));
	}

	static std::string Base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len);

	static std::string Base64_decode(std::string const& encoded_string);
};

//
//
//  CrossAppx
//
//  Created by kevin on 15-1-29.
//  Copyright (c) 2014 http://9miao.com All rights reserved.
//

#include "MyBase64.h"

MyBase64::MyBase64(void)
{
}

MyBase64::~MyBase64(void) 
{
}

std::string MyBase64::Base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
	std::string MyBase64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	std::string ret;
	int i = 0;
	int j = 0;
	unsigned char char_array_3[3];
	unsigned char char_array_4[4];
	while (in_len--) {
		char_array_3[i++] = *(bytes_to_encode++);
		if (i == 3) {
			char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
			char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
			char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
			char_array_4[3] = char_array_3[2] & 0x3f;
			for (i = 0; (i < 4); i++)
				ret += MyBase64_chars[char_array_4[i]];
			i = 0;
		}
	}
	if (i) {
		for (j = i; j < 3; j++)
			char_array_3[j] = '\0';
		char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
		char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
		char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
		char_array_4[3] = char_array_3[2] & 0x3f;
		for (j = 0; (j < i + 1); j++)
			ret += MyBase64_chars[char_array_4[j]];
		while ((i++ < 3))
			ret += '=';
	}
	return ret;
}

std::string MyBase64::Base64_decode(std::string const& encoded_string) {
	std::string MyBase64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	int in_len = encoded_string.size();
	int i = 0;
	int j = 0;
	int in_ = 0;
	unsigned char char_array_4[4], char_array_3[3];
	std::string ret;
	while (in_len-- && (encoded_string[in_] != '=') && is_Base64(encoded_string[in_])) {
		char_array_4[i++] = encoded_string[in_]; in_++;
		if (i == 4) {
			for (i = 0; i < 4; i++)
				char_array_4[i] = MyBase64_chars.find(char_array_4[i]);
			char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
			char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
			char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
			for (i = 0; (i < 3); i++)
				ret += char_array_3[i];
			i = 0;
		}
	}
	if (i) {
		for (j = i; j < 4; j++)
			char_array_4[j] = 0;
		for (j = 0; j < 4; j++)
			char_array_4[j] = MyBase64_chars.find(char_array_4[j]);
		char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
		char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
		char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
		for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
	}
	return ret;
}