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.

Contents

monero_utils contains Monero- and MyMonero-specific implementations, wrappers, and declarations, and the MyMonero JS and wasm 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.

A ready-made entrypoint for interacting with MyMoneroCoreBridge is located at monero_utils/monero_utils.js with usage require("./monero_utils/monero_utils")({}).then(function(monero_utils) { }).

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

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

Usage

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.

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_requestURI_utils

Functions for generating and parsing monero request URIs. Supports multiple currencies and formats.

---

monero_utils/monero_sendingFunds_utils

Contains convenience implementations such as SendFunds(…) for constructing arguments to monero_utils/monero_utils:create_transaction.

This function will likely make it into mymonero-core-cpp in the future.

One of the arguments to SendFunds, preSuccess_nonTerminal_statusUpdate_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.

---

monero_utils/monero_utils

Examples

const mymonero = require("mymonero_core_js/index");
// or just "mymonero_core_js/monero_utils/monero_utils"
async function foo()
{
    const monero_utils = await mymonero.monero_utils;
    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, which you access through monero_utils/monero_utils.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 when functions are called via monero_utils.

^{* 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.}

^{** for proper exception handling given that MyMoneroCoreBridge functions return { err_msg: } rather than throwing}

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

derive_public_key

derive_subaddress_public_key

decodeRct

estimate_rct_tx_size

calculate_fee

estimated_tx_network_fee

Creating Transactions

These functions support Bulletproofs under the hood but don't take bulletproof as a parameter because that behavior is controlled by a hardcoded use_fork_rules function. Bulletproofs is not currently enabled.

create_signed_transaction

• Safe to call over IPC as it takes string rather than native JS objects as args.

create_signed_transaction__nonIPCsafe

• Takes JSBigInt rather than string args.

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

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).

Contributors

• 💿 endogenic (Paul Shapiro) Maintainer

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

• 🏄‍♂️ paullinator (Paul Puey) API design

• 🔒 cryptochangement Subaddress send & decode support; Initial tests

• 💩 henrynguyen5 Tests; Ledger support research