Merge pull request #46 from Faithful-Resource-Pack/discord-auth-provider

[Webapp Vue App] Added Discord auth provider

.env.example

@@ -1,22 +1,38 @@
 PORT=8000
 DEV=true
+VERBOSE=false
 
 FIRESTORM_URL=https://url-to-firesto.rm
 FIRESTORM_TOKEN=abcdefghijklmnopqrstuvwxyz
-
 DB_IMAGE_ROOT=https://database.faithfulpack.net
 
-VERBOSE=false
-PURGE_PASSWORD=password123
-
 # disable cache for dev
 NO_CACHE=true
 
+# ====================
+#     INTEGRATIONS
+# ====================
+
+# cloudflare
 CLOUDFLARE_EMAIL=""
 CLOUDFLARE_KEY=""
 CLOUDFLARE_PASSWORD=""
+PURGE_PASSWORD=password123
 
+# curseforge
 CURSEFORGE_API_KEY=""
 
+# discord
 BOT_PASSWORD=test
 WEBHOOK_URL=https://discord.com/api/webhooks/123456789123456789/a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0
+
+# ====================
+#    AUTH PROVIDERS
+# ====================
+
+# needs quotes because dotenv limitations
+AUTH_URLS={"webapp": "http://localhost/"}
+
+# discord
+DISCORD_CLIENT_ID=abcdef123456789
+DISCORD_CLIENT_SECRET=veryveryverysecret

src/v2/controller/auth.controller.ts

@@ -0,0 +1,92 @@
+import { Request as ExRequest, Response as ExResponse } from "express";
+import { Body, Controller, Get, Path, Post, Query, Request, Route, Tags } from "tsoa";
+import AuthService from "../service/auth.service";
+
+@Route("auth")
+@Tags("Auth")
+export class AuthController extends Controller {
+	private readonly service = new AuthService();
+
+	/**
+	 * Redirects to Discord oauth2 authorization page
+	 * @param target Redirect target app
+	 */
+	@Get("discord/{target}")
+	public discordAuthGrant(@Path() target: string, @Request() request: ExRequest) {
+		const redirectURI = this.service.getRedirectURI(request, target);
+
+		const response = (<any>request).res as ExResponse;
+		const params = new URLSearchParams();
+		params.append("client_id", process.env.DISCORD_CLIENT_ID);
+		params.append("response_type", "code");
+		params.append("scope", "identify");
+		params.append("redirect_uri", redirectURI);
+
+		response.redirect(`https://discord.com/api/oauth2/authorize?${params.toString()}`);
+	}
+
+	/**
+	 * Handles Discord authorization page redirect
+	 * @param target Where to post the auth (provided in /auth/discord/{target})
+	 */
+	@Get("discord/callback/{target}")
+	public async discordAuthCallback(
+		@Path() target: string,
+		@Query() code: string,
+		@Request() request: ExRequest,
+	) {
+		const params = new URLSearchParams();
+		params.append("client_id", process.env.DISCORD_CLIENT_ID);
+		params.append("client_secret", process.env.DISCORD_CLIENT_SECRET);
+		params.append("grant_type", "authorization_code");
+		params.append("code", code);
+		params.append("redirect_uri", `${this.service.getApiUrl(request)}${request.path}`);
+		params.append("scope", "identify");
+
+		const res = (<any>request).res as ExResponse;
+		const tokenResponse = await fetch("https://discord.com/api/oauth2/token", {
+			method: "POST",
+			body: params,
+		});
+
+		const json: any = await tokenResponse.json();
+
+		if ("error" in json) {
+			res.status(500).json(json).end();
+			return;
+		}
+
+		const redirect = new URLSearchParams();
+		redirect.append("access_token", json.access_token);
+		redirect.append("refresh_token", json.refresh_token);
+		redirect.append("expires_in", json.expires_in);
+		res.redirect(`${this.service.targetToURL(target)}?${redirect.toString()}`);
+	}
+
+	/**
+	 * Handles Discord refresh for new sessions
+	 */
+	@Post("discord/refresh")
+	public async discordAuthRefresh(@Body() refresh_token: string, @Request() request: ExRequest) {
+		const params = new URLSearchParams();
+		params.append("client_id", process.env.DISCORD_CLIENT_ID);
+		params.append("client_secret", process.env.DISCORD_CLIENT_SECRET);
+		params.append("grant_type", "refresh_token");
+		params.append("refresh_token", refresh_token);
+
+		const res = (<any>request).res as ExResponse;
+		const tokenResponse = await fetch("https://discord.com/api/oauth2/token", {
+			method: "POST",
+			body: params,
+		});
+
+		const json: any = await tokenResponse.json();
+
+		if ("error" in json) {
+			res.status(500).json(json).end();
+			return;
+		}
+
+		res.json(json).end();
+	}
+}

src/v2/service/auth.service.ts

@@ -0,0 +1,31 @@
+import { Request as ExRequest } from "express";
+import { NotFoundError } from "../tools/ApiError";
+
+// REDIRECT URL IS '<origin>/auth/<provider>/callback/<target>'
+const REDIRECT_URI_PATHNAME = "/callback/";
+// example with discord provider:
+// REDIRECT URL IS '<origin>/auth/discord/callback'
+
+export default class AuthService {
+	getApiUrl(request: ExRequest): string {
+		return `${request.protocol}://${request.headers.host}`;
+	}
+
+	rawTargetToURL(target: string): string {
+		const url = JSON.parse(process.env.AUTH_URLS)[target];
+		if (!url) throw new NotFoundError("Target not found!");
+		return url;
+	}
+
+	targetToURL(target: string): string {
+		return this.rawTargetToURL(target).replace(/\/$/, "");
+	}
+
+	getRedirectURI(request: ExRequest, target: string): string {
+		const apiOrigin = this.getApiUrl(request);
+		const requestPath = request.path;
+		const pathSplit = requestPath.split("/");
+		pathSplit.pop(); // remove target
+		return `${apiOrigin.replace(/\/$/, "")}${pathSplit.join("/")}${REDIRECT_URI_PATHNAME}${target}`;
+	}
+}