sign-in-with-ethereum-parser/lib/abnf.ts

Parse Messages that conform to EIP-4361: Sign In with Ethereum (SIWE)

import { grammar } from "./siwe-grammar";
import { cb } from "./callbacks";
import apgLib from "apg-js/src/apg-lib/node-exports";
const grammarObj = new grammar();

export class ParsedMessage {
  scheme: string | undefined;
  domain: string;
  address: string;
  statement: string | undefined;
  uri: string;
  version: string;
  chainId: number;
  nonce: string;
  issuedAt: string;
  expirationTime: string | undefined;
  notBefore: string | undefined;
  requestId: string | undefined;
  resources: Array<string> | undefined;
  uriElements: {
    scheme: string;
    userinfo: string | undefined;
    host: string | undefined;
    port: string | undefined;
    path: string;
    query: string | undefined;
    fragment: string | undefined;
  };

  // and display it on an HTML page.
  constructor(msg: string) {
    const parser = new apgLib.parser();
    parser.callbacks["sign-in-with-ethereum"] = cb.signInWithEtherium;
    parser.callbacks["oscheme"] = cb.oscheme;
    parser.callbacks["domain"] = cb.domain;
    parser.callbacks["LF"] = cb.lineno;
    parser.callbacks["ex-title"] = cb.exTitle;
    parser.callbacks["nb-title"] = cb.nbTitle;
    parser.callbacks["ri-title"] = cb.riTitle;
    parser.callbacks["re-title"] = cb.reTitle;
    parser.callbacks["address"] = cb.address;
    parser.callbacks["statement"] = cb.statement;
    parser.callbacks["empty-statement"] = cb.emptyStatement;
    parser.callbacks["version"] = cb.version;
    parser.callbacks["chain-id"] = cb.chainId;
    parser.callbacks["nonce"] = cb.nonce;
    parser.callbacks["issued-at"] = cb.issuedAt;
    parser.callbacks["expiration-time"] = cb.expirationTime;
    parser.callbacks["not-before"] = cb.notBefore;
    parser.callbacks["request-id"] = cb.requestId;
    parser.callbacks["uri"] = cb.uri;
    parser.callbacks["uri-r"] = cb.uriR;
    parser.callbacks["resource"] = cb.resource;
    parser.callbacks["scheme"] = cb.scheme;
    parser.callbacks["userinfo-at"] = cb.userinfo;
    parser.callbacks["host"] = cb.host;
    parser.callbacks["IP-literal"] = cb.ipLiteral;
    parser.callbacks["port"] = cb.port;
    parser.callbacks["path-abempty"] = cb.pathAbempty;
    parser.callbacks["path-absolute"] = cb.pathAbsolute;
    parser.callbacks["path-rootless"] = cb.pathRootless;
    parser.callbacks["path-empty"] = cb.pathEmpty;
    parser.callbacks["query"] = cb.query;
    parser.callbacks["fragment"] = cb.fragment;
    parser.callbacks["IPv4address"] = cb.ipv4;
    parser.callbacks["nodcolon"] = cb.nodcolon;
    parser.callbacks["dcolon"] = cb.dcolon;
    parser.callbacks["h16"] = cb.h16;
    parser.callbacks["h16c"] = cb.h16;
    parser.callbacks["h16n"] = cb.h16;
    parser.callbacks["h16cn"] = cb.h16;
    parser.callbacks["dec-octet"] = cb.decOctet;
    parser.callbacks["dec-digit"] = cb.decDigit;

    // initialize parsed elements
    const elements = {
      errors: [],
      lineno: 1,
      scheme: undefined,
      domain: undefined,
      address: undefined,
      statement: undefined,
      uri: undefined,
      version: undefined,
      chainId: undefined,
      nonce: undefined,
      issuedAt: undefined,
      expirationTime: undefined,
      notBefore: undefined,
      requestId: undefined,
      resources: undefined,
      uriElements: {
        scheme: undefined,
        userinfo: undefined,
        host: undefined,
        port: undefined,
        path: undefined,
        query: undefined,
        fragment: undefined,
      },
    };

    const result = parser.parse(grammarObj, 0, msg, elements);
    let throwMsg = "";
    for (let i = 0; i < elements.errors.length; i += 1) {
      throwMsg += elements.errors[i] + "\n";
    }
    if (!result.success) {
      throwMsg += `Invalid message: ${JSON.stringify(result)}`;
    }
    if (throwMsg !== "") {
      throw new Error(throwMsg);
    }

    this.scheme = elements.scheme;
    this.domain = elements.domain;
    this.address = elements.address;
    this.statement = elements.statement;
    this.uri = elements.uri;
    this.version = elements.version;
    this.chainId = elements.chainId;
    this.nonce = elements.nonce;
    this.issuedAt = elements.issuedAt;
    this.expirationTime = elements.expirationTime;
    this.notBefore = elements.notBefore;
    this.requestId = elements.requestId;
    this.resources = elements.resources;
    this.uriElements = elements.uriElements;
  }
}

export const isUri = (uri: string) => {
  const parser = new apgLib.parser();
  parser.callbacks["IP-literal"] = cb.ipLiteral;
  parser.callbacks["IPv4address"] = cb.ipv4;
  parser.callbacks["nodcolon"] = cb.nodcolon;
  parser.callbacks["dcolon"] = cb.dcolon;
  parser.callbacks["h16"] = cb.h16;
  parser.callbacks["h16c"] = cb.h16;
  parser.callbacks["h16n"] = cb.h16;
  parser.callbacks["h16cn"] = cb.h16;
  parser.callbacks["dec-octet"] = cb.decOctet;
  parser.callbacks["dec-digit"] = cb.decDigit;

  const data = { errors: [] };
  const result = parser.parse(grammarObj, "uri-r", uri, data);

  return result.success;
};