parse-siwe - a Sign in with Ethereum Parser

ERC-4361: Sign-In with Ethereum establishes a standard for using an Ethereum account to sign into services that support the standard. ERC-4361 defines a message format for this purpose and any application implementing the standard will need to parse that message, validating each of the line items defined in it. parse-siwe is such a parser. It is designed to be simple to use and simple to integrate into either Node.js or web page applications.

Some highlights of its features:

• it is stand alone - it has no external dependencies
• well-tested
• URI validation - includes a complete and well-tested URI parser
• ERC-55 options - includes a keccak-256 hash function
  • validation of Ethereum address ERC-55 encoding
  • convert the Ethereum address to ERC-55 encoding
  • ignore ERC-55 encoding
• date time validation
• correct handling of statement, request ID and resources
  • these optional items can be empty as well as missing or present
• good error reporting (Well, pretty good. Usually, but not always, points out the offending message line.)
• can be used in Node.js or web page application

Installation and Basic Usage

Installation

In your working directory,

npm init
npm install parse-siwe

Sample Usage

import { parseSiweMessage } from 'parse-siwe';

const msg = `example.com:80 wants you to sign in with your Ethereum account:
0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2

Valid statement

URI: https://example.com/login
Version: 1
Chain ID: 2
Nonce: 32891756
Issued At: 2021-09-30T16:25:24Z
Request ID: someRequestId
Resources:
- ftp://myftpsite.com/
- https://example.com/mypage`;

try {
  const obj = parseSiweMessage(msg, 'validate');
  console.log('output message object');
  console.dir(obj);
} catch (e) {
  console.log(`parsing error: ${e.message}`);
}

./examples/node-app.js provides a more complete example of its usage. ./examples/web.html demonstrates its use in a simple web page.

Documentation

The documentation is in the code as JSDoc comments. To generate the documentation use npm run jsdoc

The documentation will be at out/index.html. Or view it online here.

License

2-Clause BSD License