@didtools/pkh-ethereum/dist/authmethod.js

Implements support to authenticate, authorize and verify with Ethereum accounts as a did:pkh with SIWE(X) and CACAO. Primarly used with `did-session` and `@didtools/cacao`.

import { Cacao, SiweMessage } from '@didtools/cacao';
import { randomString } from '@stablelib/random';
import { AccountId } from 'caip';
import { safeSend, normalizeAccountId } from './utils.js';
import { bytesToHex, utf8ToBytes } from '@noble/hashes/utils';
/**
 * SIWX Version
 */ export const VERSION = '1';
/**
 * CAIP2 for ethereum, used in CAIP10 (acountId)
 */ export const CHAIN_NAMESPACE = 'eip155';
function encodeHexStr(str) {
    return `0x${bytesToHex(utf8ToBytes(str))}`;
}
export var EthereumWebAuth;
(function(EthereumWebAuth) {
    async function getAuthMethod(ethProvider, account) {
        if (typeof window === 'undefined') throw new Error('Web Auth method requires browser environment');
        const domain = window.location.hostname;
        return async (opts)=>{
            opts.domain = domain;
            return createCACAO(opts, ethProvider, account);
        };
    }
    /**
   * Get a configured authMethod for an Ethereum account in a web based environment
   */ // eslint-disable-next-line @typescript-eslint/require-await
    EthereumWebAuth.getAuthMethod = getAuthMethod;
})(EthereumWebAuth || (EthereumWebAuth = {}));
export var EthereumNodeAuth;
(function(EthereumNodeAuth) {
    async function getAuthMethod(ethProvider, account, appName) {
        if (!appName) throw new Error('Node Auth method requires an application name gethAuthMethod(ethProvider, account, appName)');
        return async (opts)=>{
            opts.domain = appName;
            return createCACAO(opts, ethProvider, account);
        };
    }
    /**
   * Get a configured authMethod for an Ethereum account in a Node based environment
   */ // eslint-disable-next-line @typescript-eslint/require-await
    EthereumNodeAuth.getAuthMethod = getAuthMethod;
})(EthereumNodeAuth || (EthereumNodeAuth = {}));
async function createCACAO(opts, ethProvider, account) {
    const now = new Date();
    const oneWeekLater = new Date(now.getTime() + 7 * 24 * 60 * 60 * 1000);
    const normAccount = normalizeAccountId(account);
    const siweMessage = new SiweMessage({
        domain: opts.domain,
        address: normAccount.address,
        statement: opts.statement ?? 'Give this application access to some of your data on Ceramic',
        uri: opts.uri,
        version: VERSION,
        nonce: opts.nonce ?? randomString(10),
        issuedAt: now.toISOString(),
        expirationTime: opts.expirationTime ?? oneWeekLater.toISOString(),
        chainId: normAccount.chainId.reference,
        resources: opts.resources
    });
    const signature = await safeSend(ethProvider, 'personal_sign', [
        encodeHexStr(siweMessage.signMessage({
            eip55: true
        })),
        normAccount.address
    ]);
    siweMessage.signature = signature;
    return Cacao.fromSiweMessage(siweMessage);
}
async function requestChainId(provider) {
    const chainIdHex = await safeSend(provider, 'eth_chainId', []);
    return parseInt(chainIdHex, 16);
}
/**
 * Helper function to get an accountId (CAIP10) for an Ethereum account, uses ethProvider to get chainId/network
 */ export async function getAccountId(ethProvider, address) {
    const ethChainId = await requestChainId(ethProvider);
    const chainId = `${CHAIN_NAMESPACE}:${ethChainId}`;
    return new AccountId({
        address: address.toLowerCase(),
        chainId
    });
}