MyMonero Core JS

Info

1. Legal
2. What's in This Repo?
3. Usage

Contributing

1. QA
2. Pull Requests
3. Building MyMoneroCoreCpp from Scratch
4. Contributors

Info

Legal

See LICENSE.txt for license.

All source code copyright © 2014-2018 by MyMonero. All rights reserved.

What's in This Repo?

This repository holds the Javascript source code for the Monero/CryptoNote cryptography and protocols, plus lightwallet functions which power the official MyMonero apps.

There is also a chain of build scripts which is capable of building a JS module by transpiling a subset of Monero source code via emscripten, which relies upon static boost libs, for which there is also a script for building from source.

It's possible to run your own lightweight (hosted) wallet server by using either OpenMonero or the lightweight wallet server which MyMonero has developed specially to be open-sourced for the Monero community (PR is in the process of being merged). However, MyMonero also offers highly optimized, high throughput, secure hosting for a nominal, scaling fee per active wallet per month to wallet app makers who would like to use this library, mymonero-core-js, to add hosted Monero wallets to their app.

The benefit of offering a hosted wallet rather than requiring users to use a remote node is that scanning doesn't have to take place on the mobile device, so the user doesn't have to download the blockchain and scan on their device, or wait when they switch to a new device or come back to the app after a period of time. For more information, please reach out to Paul at [e-mail]. We work hard to support the growth of the Monero ecosystem, and will be happy to work with integrators on flexible pricing.

Contents

monero_utils contains Monero- and MyMonero-specific implementations, wrappers, and declarations, and the MyMonero JS and wasm (and asm.js fallback/polyfill) implementations for the underlying cryptography behind Monero.

monero_utils/MyMoneroCoreCpp* are produced by transpiling Monero core C++ code to JS via Emscripten (See Building MyMoneroCoreCpp). A Module instance is managed by monero_utils/MyMoneroCoreBridge.js.

Library integrators may use MyMoneroCoreBridge by require("./monero_utils/MyMoneroCoreBridge")({}).then(function(coreBridge_instance) { }). (This was formerly accessed via the now-deprecated monero_utils/monero_utils). You may also access this MyMoneroCoreBridge promise via the existing index.js property monero_utils_promise (the name has been kept the same for API stability).

Many related utility functions and data structures are located throughout monero_utils/, cryptonote_utils, and hostAPI. Usage below.

Various convenience scripts are provided in ./bin.

This readme is located at README.md, and the license is located at LICENSE.txt.

Usage

If you would like to package this library to run in a standalone manner within, e.g. a webpage, similarly to how the old mymonero.com used this library, a script is provided to bundle everything for you. It's located at bin/package_browser_js. If you package the library in this manner, the resulting mymonero-core.js file can be included via a script tag. The index.js of the library will then be available as the global variable mymonero_core_js.

Alternatively you can bundle the contents in any other manner you prefer, including directly accessing them via your favorite module system.

hostAPI

Use the functions in the modules in hostAPI for convenience implementations of (a) networking to a MyMonero-API-compatible server, (b) constructing common request bodies, and (c) parsing responses.

For a working example usage of hostAPI, see mymonero-app-js/HostedMoneroAPIClient. However, there's no need to conform to this example's implementation, especially for sending transactions, as the response parsing and request construction for transactions is now handled within the implementation.

Examples

const endpointPath = "get_address_info"
const parameters = net_service_utils.New_ParametersForWalletRequest(address, view_key__private)

monero_utils_promise.then(function(monero_utils) {
    response_parser_utils.Parsed_AddressTransactions__keyImageManaged(
        data,
        address, view_key__private, spend_key__public, spend_key__private,
        monero_utils,
        function(err, returnValuesByKey) {
            …
        }
    )
})

where data is the JSON response. Note you must pass in a resolved monero_utils instance (see below for usage) so that such functions can remain synchronous without having to wait for the promise.

__keyImageManaged means that key images will be generated and then cached for a large performance boost for you. The caveat of this convenience is that you should make sure to call DeleteManagedKeyImagesForWalletWith on monero_utils/monero_keyImage_cache_utils (below) when you're done with them, such as on the teardown of a related wallet instance.

---

cryptonote_utils/mnemonic_languages

It's not generally at all necessary to interact with this module unless you want to, e.g., construct a GUI that needs a list of support mnemonics.

In other words, if your app only needs to generate a mnemonic, you can avoid using this code module entirely by simply passing a language code (of "en", "en-US", "ja", "zh" etc) to the below monero_utils function which generates wallets.

---

cryptonote_utils/nettype

You'll need this module to construct the nettype argument for passing to various other functions.

Examples

const nettype = require('cryptonote_utils/nettype').network_type.MAINNET

---

cryptonote_utils/biginteger

Used extensively for managing Monero amounts in atomic units to ensure precision.

Examples

const JSBigInt = require('../mymonero_core_js/cryptonote_utils/biginteger').BigInteger
const amount = new JSBigInt('12300000')
const amount_str = monero_amount_format_utils.formatMoney(amount)

---

cryptonote_utils/money_format_utils

It's not necessary to use this module directly. See monero_utils/monero_amount_format_utils.

---

monero_utils/monero_amount_format_utils

const monero_amount_format_utils = require("monero_utils/monero_amount_format_utils");
const formatted_string = monero_amount_format_utils.formatMoney(a JSBigInt)

Functions: formatMoneyFull, formatMoneyFullSymbol, formatMoney, formatMoneySymbol, parseMoney(str) -> JSBigInt

---

monero_utils/monero_txParsing_utils

Use these functions to derive additional state from transaction rows which were returned by a server and then parsed by hostAPI.

• IsTransactionConfirmed(tx, blockchain_height)
• IsTransactionUnlocked(tx, blockchain_height)
• TransactionLockedReason(tx, blockchain_height)

---

monero_utils/monero_keyImage_cache_utils

Use these functions to directly interact with the key image cache.

• Lazy_KeyImage(…) Generate a key image directly and cache it. Returns cached values.
• DeleteManagedKeyImagesForWalletWith(address) Call this to avoid leaking keys if you use any of the response parsing methods (above) which are suffixed with __keyImageManaged.

---

monero_utils/monero_paymentID_utils

Contains functions to validating payment ID formats. To generate payment IDs, see monero_utils.

---

monero_utils/monero_sendingFunds_utils

Used to contain a convenience implementation of SendFunds(…) for constructing arguments to create_transaction-type functions. However that's been moved to C++ and exposed via a single function on MyMoneroCoreBridge called async__send_funds.

One of the callbacks to this function, status_update_fn, supplies status updates via codes that can be translated into messages. Codes are located on SendFunds_ProcessStep_Code and messages are located at SendFunds_ProcessStep_MessageSuffix within this file, monero_sendingFunds_utils. This lookup will probably make it into MyMoneroCoreBridge for concision.

---

monero_utils/MyMoneroCoreBridge

Examples

const mymonero = require("mymonero_core_js/index");
// or just "mymonero_core_js/monero_utils/MyMoneroCoreBridge"
async function foo()
{
    const monero_utils = await mymonero.monero_utils_promise;
    const nettype = mymonero.nettype_utils.network_type.MAINNET;
    const decoded = monero_utils.address_and_keys_from_seed("…", nettype);
    // read decoded.address_string
    //
}
foo()

var decoded = monero_utils.decode_address("…", nettype);

Available functions

Each of these functions is implemented^* in monero_utils/MyMoneroCoreBridge.js.

The arguments and return values for these functions are explicitly called out by MyMoneroCoreBridge.js, so that will be the most complete documentation for the moment. Return values are all embedded within a JS dictionary unless they're singular values. Errors are thrown as exceptions.

^{* The functions' actual implementations are in WebAssembly which is produced via emscripten from exactly matching C++ functions in mymonero-core-cpp. This allows core implementation to be shared across all platforms.}

is_subaddress

is_integrated_address

new_payment_id

new__int_addr_from_addr_and_short_pid

decode_address

newly_created_wallet

are_equal_mnemonics

mnemonic_from_seed

seed_and_keys_from_mnemonic

validate_components_for_login

address_and_keys_from_seed

• This function was known as create_address in the previous mymonero-core-js API.

generate_key_image

generate_key_derivation

derivation_to_scalar

derive_public_key

derive_subaddress_public_key

decodeRct

decodeRctSimple

estimated_tx_network_fee

estimate_rct_tx_size

async__send_funds

• This method takes simple, familiar parameters in the form of a keyed dictionary, and has a handful of callbacks which supply pre-formed request parameters for sending directly to a MyMonero or lightweight wallet-compatible API server. Responses may be sent directly back to the callbacks' callbacks, as they are now parsed and handled entirely within the implementation. This function's interface used to reside in monero_sendingFunds_utils. See tests/sendingFunds.spec.js for example usage.

Contributing

QA

Please submit any bugs as Issues unless they have already been reported.

Suggestions and feedback are very welcome!

Pull Requests

We'll merge nearly anything constructive. Contributors welcome and credited in releases.

We often collaborate over IRC in #mymonero on Freenode.

All development happens off the develop branch like the Gitflow Workflow.

Building MyMoneroCoreCpp from Scratch

There's no need to build monero_utils/MyMoneroCoreCpp as a build is provided, but if you were for example interested in adding a C++ function, you could use the information in this section to transpile it to JS.

Repository Setup

• Execute bin/update_submodules

Install Emscripten SDK

A version of emscripten of at least 1.38.13 with these updates is required so that random bit generation safety can be ensured.

Ensure you've properly installed Emscripten and exposed the Emscripten executables in your PATH, e.g.:

source ./emsdk_env.sh

Boost for Emscripten

Depends upon: Emscripten SDK

Download a copy of the contents of the Boost source into ./contrib/boost-sdk/.

• Execute bin/build-boost-emscripten.sh

Emscripten Module

Depends upon: Repository Setup, Emscripten SDK, Boost for Emscripten

• Execute bin/build-emcpp.sh

Or if you want to copy the build products to their distribution locations,

• Execute bin/archive-emcpp.sh

NOTE If you want to build for asmjs instead of wasm, edit CMakeLists.txt to turn the MM_EM_ASMJS option to ON before you run either the build or archive script. Finally, at every place you instantiate a MyMoneroCoreBridge instance, ensure that the asmjs flag passed as an init argument is set to true (If not, loading will not work).

Maintainers and Advisors

• 💿 endogenic (Paul Shapiro) Maintainer

• 🍄 luigi Major contiributor of original JS core crypto and Monero-specific routines; Advisor

Authors

• Paul Shapiro

• luigi1111

• Lucas Jones

• gutenye

• HenryNguyen5

• cryptochangements34

• bradoyler

• rex4539

• paullinator