/**************************************************************************/
/*  crypto_core.h                                                         */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
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/**************************************************************************/

#pragma once

#include "core/error/error_list.h"

#include <cstddef>
#include <cstdint>

class String;

class CryptoCore {
public:
	class RandomGenerator {
	private:
		void *entropy = nullptr;
		void *ctx = nullptr;

		static int _entropy_poll(void *p_data, unsigned char *r_buffer, size_t p_len, size_t *r_len);

	public:
		RandomGenerator();
		~RandomGenerator();

		Error init();
		Error get_random_bytes(uint8_t *r_buffer, size_t p_bytes);
	};

	class MD5Context {
	private:
		void *ctx = nullptr;

	public:
		MD5Context();
		~MD5Context();

		Error start();
		Error update(const uint8_t *p_src, size_t p_len);
		Error finish(unsigned char r_hash[16]);
	};

	class SHA1Context {
	private:
		void *ctx = nullptr;

	public:
		SHA1Context();
		~SHA1Context();

		Error start();
		Error update(const uint8_t *p_src, size_t p_len);
		Error finish(unsigned char r_hash[20]);
	};

	class SHA256Context {
	private:
		void *ctx = nullptr;

	public:
		SHA256Context();
		~SHA256Context();

		Error start();
		Error update(const uint8_t *p_src, size_t p_len);
		Error finish(unsigned char r_hash[32]);
	};

	class AESContext {
	private:
		void *ctx = nullptr;

	public:
		AESContext();
		~AESContext();

		Error set_encode_key(const uint8_t *p_key, size_t p_bits);
		Error set_decode_key(const uint8_t *p_key, size_t p_bits);
		Error encrypt_ecb(const uint8_t p_src[16], uint8_t r_dst[16]);
		Error decrypt_ecb(const uint8_t p_src[16], uint8_t r_dst[16]);
		Error encrypt_cbc(size_t p_length, uint8_t r_iv[16], const uint8_t *p_src, uint8_t *r_dst);
		Error decrypt_cbc(size_t p_length, uint8_t r_iv[16], const uint8_t *p_src, uint8_t *r_dst);
		Error encrypt_cfb(size_t p_length, uint8_t p_iv[16], const uint8_t *p_src, uint8_t *r_dst);
		Error decrypt_cfb(size_t p_length, uint8_t p_iv[16], const uint8_t *p_src, uint8_t *r_dst);
	};

	static String b64_encode_str(const uint8_t *p_src, size_t p_src_len);
	static Error b64_encode(uint8_t *r_dst, size_t p_dst_len, size_t *r_len, const uint8_t *p_src, size_t p_src_len);
	static Error b64_decode(uint8_t *r_dst, size_t p_dst_len, size_t *r_len, const uint8_t *p_src, size_t p_src_len);

	static Error md5(const uint8_t *p_src, size_t p_src_len, unsigned char r_hash[16]);
	static Error sha1(const uint8_t *p_src, size_t p_src_len, unsigned char r_hash[20]);
	static Error sha256(const uint8_t *p_src, size_t p_src_len, unsigned char r_hash[32]);
};
