From 76f367b957cacbbae679e77eac86c593ac5cb514 Mon Sep 17 00:00:00 2001
From: Justin Spahr-Summers <justin@anthropic.com>
Date: Mon, 17 Feb 2025 12:17:00 +0000
Subject: [PATCH] WIP client registration handler for Express

---
 .../auth/handlers/clientRegistration.ts       | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 src/server/auth/handlers/clientRegistration.ts

diff --git a/src/server/auth/handlers/clientRegistration.ts b/src/server/auth/handlers/clientRegistration.ts
new file mode 100644
index 00000000..cdbe35aa
--- /dev/null
+++ b/src/server/auth/handlers/clientRegistration.ts
@@ -0,0 +1,47 @@
+import { Request, Response } from "express";
+import { OAuthClientInformationFull, OAuthClientMetadataSchema, OAuthClientRegistrationError } from "../../../shared/auth.js";
+import crypto from 'node:crypto';
+import bodyParser from 'body-parser';
+
+async function handler(requestBody: unknown): Promise<OAuthClientInformationFull | OAuthClientRegistrationError> {
+  let clientMetadata;
+  try {
+    clientMetadata = OAuthClientMetadataSchema.parse(requestBody);
+  } catch (error) {
+    return { error: "invalid_client_metadata", error_description: String(error) };
+  }
+
+  // Implement RFC 7591 dynamic client registration
+  const clientId = crypto.randomUUID();
+  const clientSecret = clientMetadata.token_endpoint_auth_method !== 'none'
+    ? crypto.randomBytes(32).toString('hex')
+    : undefined;
+  const clientIdIssuedAt = Math.floor(Date.now() / 1000);
+
+  const clientInfo: OAuthClientInformationFull = {
+    ...clientMetadata,
+    client_id: clientId,
+    client_secret: clientSecret,
+    client_id_issued_at: clientIdIssuedAt,
+    client_secret_expires_at: 0 // Set to 0 for non-expiring secret
+  };
+
+  // TODO: Store client information securely
+
+  return clientInfo;
+}
+
+export const clientRegistrationHandler = (req: Request, res: Response) => bodyParser.json()(req, res, (err) => {
+  if (err === undefined) {
+    handler(req.body).then((result) => {
+      if ("error" in result) {
+        res.status(400).json(result);
+      } else {
+        res.status(201).json(result);
+      }
+    }, (error) => {
+      console.error("Uncaught error in client registration handler:", error);
+      res.status(500).end("Internal Server Error");
+    });
+  }
+});
\ No newline at end of file