n8n/packages/@n8n/nodes-langchain/nodes/trigger/ChatTrigger/GenericFunctions.ts

import type { ICredentialDataDecryptedObject, IWebhookFunctions } from 'n8n-workflow';
import basicAuth from 'basic-auth';
import { ChatTriggerAuthorizationError } from './error';
import type { AuthenticationChatOption } from './types';

export async function validateAuth(context: IWebhookFunctions) {
	const authentication = context.getNodeParameter('authentication') as AuthenticationChatOption;
	const req = context.getRequestObject();
	const headers = context.getHeaderData();

	if (authentication === 'none') {
		return;
	} else if (authentication === 'basicAuth') {
		// Basic authorization is needed to call webhook
		let expectedAuth: ICredentialDataDecryptedObject | undefined;
		try {
			expectedAuth = await context.getCredentials<ICredentialDataDecryptedObject>('httpBasicAuth');
		} catch {}

		if (expectedAuth === undefined || !expectedAuth.user || !expectedAuth.password) {
			// Data is not defined on node so can not authenticate
			throw new ChatTriggerAuthorizationError(500, 'No authentication data defined on node!');
		}

		const providedAuth = basicAuth(req);
		// Authorization data is missing
		if (!providedAuth) throw new ChatTriggerAuthorizationError(401);

		if (providedAuth.name !== expectedAuth.user || providedAuth.pass !== expectedAuth.password) {
			// Provided authentication data is wrong
			throw new ChatTriggerAuthorizationError(403);
		}
	} else if (authentication === 'n8nUserAuth') {
		const webhookName = context.getWebhookName();

		function getCookie(name: string) {
			const value = `; ${headers.cookie}`;
			const parts = value.split(`; ${name}=`);

			if (parts.length === 2) {
				return parts.pop()?.split(';').shift();
			}
			return '';
		}

		const authCookie = getCookie('n8n-auth');
		if (!authCookie && webhookName !== 'setup') {
			// Data is not defined on node so can not authenticate
			throw new ChatTriggerAuthorizationError(500, 'User not authenticated!');
		}
	}

	return;
}