this-city/engine/core/crypto/aes_context.cpp
2026-07-10 17:04:34 +02:00

113 lines
5.2 KiB
C++

/**************************************************************************/
/* aes_context.cpp */
/**************************************************************************/
/* 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 */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/**************************************************************************/
#include "aes_context.h"
#include "core/object/class_db.h"
using AESMode = CryptoCore::AESContext::Mode;
using AESCipher = CryptoCore::AESContext::Cipher;
Error AESContext::start(Mode p_mode, const PackedByteArray &p_key, const PackedByteArray &p_iv) {
ERR_FAIL_COND_V_MSG(mode != MODE_MAX, ERR_ALREADY_IN_USE, "AESContext already started. Call 'finish' before starting a new one.");
ERR_FAIL_COND_V_MSG(p_mode < 0 || p_mode >= MODE_MAX, ERR_INVALID_PARAMETER, "Invalid mode requested.");
// Key check.
int key_bits = p_key.size() << 3;
ERR_FAIL_COND_V_MSG(key_bits != 128 && key_bits != 256, ERR_INVALID_PARAMETER, "AES key must be either 16 or 32 bytes");
AESMode ctx_mode = AESMode::NONE;
AESCipher ctx_cipher = AESCipher::NONE;
switch (p_mode) {
case MODE_ECB_ENCRYPT:
ctx_mode = AESMode::ENCRYPT;
ctx_cipher = AESCipher::ECB;
break;
case MODE_ECB_DECRYPT:
ctx_mode = AESMode::DECRYPT;
ctx_cipher = AESCipher::ECB;
break;
case MODE_CBC_ENCRYPT:
ctx_mode = AESMode::ENCRYPT;
ctx_cipher = AESCipher::CBC;
break;
case MODE_CBC_DECRYPT:
ctx_mode = AESMode::DECRYPT;
ctx_cipher = AESCipher::CBC;
break;
default:
ERR_FAIL_V(ERR_INVALID_PARAMETER);
}
// Initialization vector.
PackedByteArray iv = p_iv;
ERR_FAIL_COND_V_MSG(ctx_cipher == AESCipher::CBC && iv.size() != 16, ERR_INVALID_PARAMETER, "The initialization vector (IV) must be exactly 16 bytes.");
if (unlikely(ctx_cipher == AESCipher::ECB && iv.size())) {
WARN_PRINT("ECB mode does not require an initialization vector (IV). Pass an empty IV argument when using ECB.");
iv.clear();
}
Error err = ctx.setup(ctx_mode, ctx_cipher, p_key.ptr(), p_key.size(), iv.size() ? iv.ptr() : nullptr, iv.size());
if (err != OK) {
return err;
}
mode = p_mode;
return OK;
}
PackedByteArray AESContext::update(const PackedByteArray &p_src) {
ERR_FAIL_COND_V_MSG(mode < 0 || mode >= MODE_MAX, PackedByteArray(), "AESContext not started. Call 'start' before calling 'update'.");
int len = p_src.size();
ERR_FAIL_COND_V_MSG(len % 16, PackedByteArray(), "The number of bytes to be encrypted must be multiple of 16. Add padding if needed");
PackedByteArray out;
out.resize(len);
Error err = ctx.update(p_src.ptr(), len, out.ptrw(), len);
ERR_FAIL_COND_V(err != OK, PackedByteArray());
return out;
}
PackedByteArray AESContext::get_iv_state() {
ERR_FAIL_V_MSG(PackedByteArray(), "Calling 'get_iv_state' is no longer supported.");
}
void AESContext::finish() {
ctx.finish(nullptr, 0);
mode = MODE_MAX;
}
void AESContext::_bind_methods() {
ClassDB::bind_method(D_METHOD("start", "mode", "key", "iv"), &AESContext::start, DEFVAL(PackedByteArray()));
ClassDB::bind_method(D_METHOD("update", "src"), &AESContext::update);
ClassDB::bind_method(D_METHOD("get_iv_state"), &AESContext::get_iv_state);
ClassDB::bind_method(D_METHOD("finish"), &AESContext::finish);
BIND_ENUM_CONSTANT(MODE_ECB_ENCRYPT);
BIND_ENUM_CONSTANT(MODE_ECB_DECRYPT);
BIND_ENUM_CONSTANT(MODE_CBC_ENCRYPT);
BIND_ENUM_CONSTANT(MODE_CBC_DECRYPT);
BIND_ENUM_CONSTANT(MODE_MAX);
}