feat: added OIDC discovery

src/core/server/app/middleware/passport/strategies/oidc/discover.ts

@@ -0,0 +1,47 @@
+import fetch from "node-fetch";
+import { URL } from "url";
+
+/**
+ * Configuration that Talk is expecting.
+ */
+export interface DiscoveryConfiguration {
+  authorizationURL?: string;
+  tokenURL?: string;
+  jwksURI?: string;
+}
+
+/**
+ * Subset of configuration as defined in the set of Provider Metadata:
+ *
+ * https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata
+ */
+interface DiscoveryRawConfiguration {
+  authorization_endpoint?: string;
+  token_endpoint?: string;
+  jwks_uri?: string;
+}
+
+/**
+ * discover will discover the configuration for the issuer.
+ *
+ * @param issuer the Issuer URL that should be used to determine the
+ *               configuration
+ */
+export async function discover(issuer: URL): Promise<DiscoveryConfiguration> {
+  // Any provider MUST provide a .well-known url that is JSON parsable based
+  // on the issuer: https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderConfig
+  const configurationURL =
+    issuer.origin +
+    issuer.pathname.replace(/\/$/, "") +
+    "/.well-known/openid-configuration";
+  const res = await fetch(configurationURL);
+
+  // Parse the configuration
+  const meta: DiscoveryRawConfiguration = await res.json();
+
+  return {
+    authorizationURL: meta.authorization_endpoint,
+    tokenURL: meta.token_endpoint,
+    jwksURI: meta.jwks_uri,
+  };
+}