haven-core-js/monero_utils/monero_keyImage_cache_utils.js

The JS library containing the Haven crypto plus lightweight wallet functions

// Copyright (c) 2014-2019, MyMonero.com
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//	conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//	of conditions and the following disclaimer in the documentation and/or other
//	materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//	used to endorse or promote products derived from this software without specific
//	prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
"use strict";
//
const Lazy_KeyImage = function(
	mutable_keyImagesByCacheKey, // pass a mutable JS dictionary
	tx_pub_key,
	out_index,
	public_address,
	view_key__private,
	spend_key__public,
	spend_key__private,
	coreBridge_instance // must pass this so this fn can remain synchronous
) {
	var cache_index = tx_pub_key + ":" + public_address + ":" + out_index;
	const cached__key_image = mutable_keyImagesByCacheKey[cache_index];
	if (
		typeof cached__key_image !== "undefined" &&
		cached__key_image !== null
	) {
		return cached__key_image;
	}
	var key_image = coreBridge_instance.generate_key_image(
		tx_pub_key,
		view_key__private,
		spend_key__public,
		spend_key__private,
		out_index,
	);
	// cache:
	mutable_keyImagesByCacheKey[cache_index] = key_image;
	//
	return key_image;
};
exports.Lazy_KeyImage = Lazy_KeyImage;
//
//
// Managed caches - Can be used by apps which can't send a mutable_keyImagesByCacheKey
const __global_managed_keyImageCaches_by_walletId = {};
function _managedKeyImageCacheWalletIdForWalletWith(public_address) {
	// NOTE: making the assumption that public_address is unique enough to identify a wallet for caching....
	// FIXME: with subaddresses, is that still the case? would we need to split them up by subaddr anyway?
	if (
		public_address == "" ||
		!public_address ||
		typeof public_address == "undefined"
	) {
		throw "managedKeyImageCacheIdentifierForWalletWith: Illegal public_address";
	}
	return "" + public_address;
}
const Lazy_KeyImageCacheForWalletWith = function(public_address) {
	var cacheId = _managedKeyImageCacheWalletIdForWalletWith(public_address);
	var cache = __global_managed_keyImageCaches_by_walletId[cacheId];
	if (typeof cache === "undefined" || !cache) {
		cache = {};
		__global_managed_keyImageCaches_by_walletId[cacheId] = cache;
	}
	return cache;
};
exports.Lazy_KeyImageCacheForWalletWith = Lazy_KeyImageCacheForWalletWith;
//
const DeleteManagedKeyImagesForWalletWith = function(public_address) {
	// IMPORTANT: Ensure you call this method when you want to clear your wallet from
	// memory or delete it, or else you could leak key images and public addresses.
	const cacheId = _managedKeyImageCacheWalletIdForWalletWith(public_address);
	delete __global_managed_keyImageCaches_by_walletId[cacheId];
	//
	const cache = __global_managed_keyImageCaches_by_walletId[cacheId];
	if (typeof cache !== "undefined") {
		throw "Key image cache still exists after deletion";
	}
};
exports.DeleteManagedKeyImagesForWalletWith = DeleteManagedKeyImagesForWalletWith;