Steam authentication with API Gateway and lambda - node.js

Question

I'm trying to create the authentication of my website using
https://github.com/LeeviHalme/node-steam-openid.
Steam OpenID: https://partner.steamgames.com/doc/features/auth
I have an API Gateway with these two endpoints:
/login
// the steamAuth file is the same module as node-steam-openid but for ts
import { SteamAuth } from "../utils/steamAuth";
export const login = async () => {
const client = new SteamAuth(
'http://localhost:3000',
`${process.env.API_URL}/consume`,
process.env.STEAM_API_KEY,
);
try {
const redirectUrl = await client.getRedirectUrl();
return {
statusCode: 302,
headers: { Location: redirectUrl }
};
} catch (e) {
console.log(e);
return {
statusCode: 500,
message: 'Internal server error'
};
}
}
/consume
import { APIGatewayEvent } from 'aws-lambda';
import { SteamAuth } from "../utils/steamAuth";
export const consume = async (event: APIGatewayEvent) => {
const client = new SteamAuth(
'http://localhost:3000',
`${process.env.API_URL}/consume`,
process.env.STEAM_API_KEY,
);
console.log(event);
try {
const user = await client.authenticate(event);
console.log('success', user);
} catch (e) {
console.log('error', e);
}
return {
statusCode: 302,
headers: { Location: 'http://localhost:3000/' },
};
}
The thing is I get this error in /consume endpoint
error TypeError: Cannot read property 'toUpperCase' of undefined
at Object.openid.verifyAssertion (/var/task/node_modules/openid/openid.js:905:28)
at openid.RelyingParty.verifyAssertion (/var/task/node_modules/openid/openid.js:68:10)
at /var/task/src/utils/steamAuth.js:60:31
at new Promise (<anonymous>)
at SteamAuth.authenticate (/var/task/src/utils/steamAuth.js:59:16)
at Runtime.consume [as handler] (/var/task/src/lambda/consume.js:9:35)
at Runtime.handleOnceNonStreaming (/var/runtime/Runtime.js:73:25)
I believe this error occurs because the verifyAssertion is waiting for an express request while it is provided an API Gateway one.
Link to the code with the mentioned function is here
Should I use another module to do the authentication as I don't really want to modify the source code of the module? I didn't find anything at the moment
Thanks!

Answer 1

I found a workaround using express in lambda. As expected, the openid module used by node-steam-openid is expecting an express request and not a lambda event.
import { SteamAuth } from "../utils/steamAuth";
const express = require('express');
const serverless = require('serverless-http');
const app = express();
app.get('/verify', async (req: any, res: any) => {
const client = new SteamAuth(
process.env.HOSTNAME,
`${process.env.API_URL}/verify`,
process.env.STEAM_API_KEY,
);
try {
const user: any = await client.authenticate(req);
} catch (e) {
throw new Error(e.message);
}
});
module.exports.verify = serverless(app);