Class Base64

KBotExt/base64.h:5–108

#include <string>

class Base64
{
	std::string base64_chars =
		"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
		"abcdefghijklmnopqrstuvwxyz"
		"0123456789+/";

public:
	static bool is_base64(const unsigned char c)
	{
		return isalnum(c) || c == '+' || c == '/';
	}

	std::string Encode(const unsigned char* bytes_to_encode, unsigned int in_len)
	{
		std::string ret;
		int i = 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 += base64_chars[char_array_4[i]];
				i = 0;
			}
		}

		if (i)
		{
			int j;
			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 += base64_chars[char_array_4[j]];

			while (i++ < 3)
				ret += '=';
		}

		return ret;
	}

	std::string Decode(const std::string& encoded_string)