feat: Sync to OSS repo

packages/auth/src/provider/steam.ts

@@ -0,0 +1,52 @@
+import { getRelativeUrl } from '../util.js';
+import { Provider } from './provider.js';
+
+const STEAM_OPENID_URL = 'https://steamcommunity.com/openid/login';
+
+export function SteamProvider(): Provider<{ steamid: string }> {
+	return {
+		type: 'steam',
+		init(routes, ctx) {
+			routes.get('/authorize', async (c) => {
+				const returnUrl = getRelativeUrl(c, './callback');
+				const openidURL =
+					`${STEAM_OPENID_URL}?` +
+					`openid.ns=${encodeURIComponent('http://specs.openid.net/auth/2.0')}&` +
+					`openid.mode=checkid_setup&` +
+					`openid.return_to=${encodeURIComponent(returnUrl)}&` +
+					`openid.realm=${encodeURIComponent(new URL(c.req.url).origin)}&` +
+					`openid.identity=${encodeURIComponent('http://specs.openid.net/auth/2.0/identifier_select')}&` +
+					`openid.claimed_id=${encodeURIComponent('http://specs.openid.net/auth/2.0/identifier_select')}`;
+				return c.redirect(openidURL);
+			});
+
+			routes.get('/callback', async (c) => {
+				const url = new URL(c.req.url);
+				const params = Object.fromEntries(url.searchParams.entries());
+
+				const verifyRes = await fetch(STEAM_OPENID_URL, {
+					method: 'POST',
+					body: new URLSearchParams({
+						...params,
+						'openid.mode': 'check_authentication'
+					}),
+					headers: {
+						'Content-Type': 'application/x-www-form-urlencoded'
+					}
+				});
+
+				const verifyText = await verifyRes.text();
+				if (!verifyText.includes('is_valid:true')) {
+					throw new Error('Steam OpenID validation failed');
+				}
+
+				const steamid = params['openid.claimed_id']?.split('/').pop();
+				if (!steamid) {
+					throw new Error('Steam ID not found');
+				}
+
+				return ctx.success(c, { steamid });
+			});
+		}
+	};
+}