fix interactions, apparently cfw doesn't speak Buffer

packages/api/src/routes/interactions/commands/hello-world.ts

@@ -10,10 +10,15 @@ export const helloWorld: InteractionHandler = (
   interaction: InteractionRequest,
   context: Context
 ): InteractionResponse => {
+  console.log({ interaction });
   return {
     type: InteractionCallbackType.CHANNEL_MESSAGE_WITH_SOURCE,
     data: {
-      content: `Hey there, ${interaction.member?.nick || interaction.user?.username}`,
+      content: `Hey there, ${
+        interaction.member?.nick ||
+        interaction.member?.user?.username ||
+        interaction.user?.username
+      }`,
     },
   };
 };

packages/api/src/routes/interactions/helpers.ts

@@ -13,6 +13,7 @@ export const verifyRequest = async (
   request: Request,
   interaction: InteractionRequest
 ): Promise<boolean> => {
+  try {
     const timestamp = request.headers.get('x-signature-timestamp');
     const signature = request.headers.get('x-signature-ed25519');
 
@@ -22,18 +23,40 @@ export const verifyRequest = async (
 
     const key = await crypto.subtle.importKey(
       'raw',
-    Buffer.from(config.publicKey, 'hex'),
+      bufferizeHex(config.publicKey),
       { name: 'NODE-ED25519', namedCurve: 'NODE-ED25519', public: true } as any,
       false,
       ['verify']
     );
 
-  return crypto.subtle.verify(
+    const verified = await crypto.subtle.verify(
       'NODE-ED25519',
       key,
-    Buffer.from(signature, 'hex'),
-    Buffer.from(timestamp + JSON.stringify(interaction))
+      bufferizeHex(signature),
+      bufferizeString(timestamp + JSON.stringify(interaction))
     );
+
+    return verified;
+  } catch (e) {
+    return false;
+  }
+};
+
+// Cloudflare Workers + SubtleCrypto has no idea what a Buffer.from() is.
+// What the fuck?
+const bufferizeHex = (input: string) => {
+  const buffer = new Uint8Array(input.length / 2);
+
+  for (let i = 0; i < input.length; i += 2) {
+    buffer[i / 2] = parseInt(input.substring(i, i + 2), 16);
+  }
+
+  return buffer;
+};
+
+const bufferizeString = (input: string) => {
+  const encoder = new TextEncoder();
+  return encoder.encode(input);
 };
 
 export type InteractionHandler = ((
@@ -59,7 +82,7 @@ export const runAsync = async (
         'Content-Type': 'application/json',
       },
       body: JSON.stringify({
-        type: InteractionCallbackType.DEFERRED_UPDATE_MESSAGE,
+        type: InteractionCallbackType.DEFERRED_CHANNEL_MESSAGE_WITH_SOURCE,
         data: {
           flags: handler.ephemeral ? InteractionFlags.EPHEMERAL : 0,
           ...response.data,
@@ -82,7 +105,7 @@ export const runAsync = async (
           'Content-Type': 'application/json',
         },
         body: JSON.stringify({
-          type: InteractionCallbackType.DEFERRED_UPDATE_MESSAGE,
+          type: InteractionCallbackType.DEFERRED_CHANNEL_MESSAGE_WITH_SOURCE,
           data: {
             content: "I'm sorry, I'm having trouble processing this request.",
             flags: InteractionFlags.EPHEMERAL,

packages/api/src/routes/interactions/interactions.ts

@@ -30,14 +30,17 @@ export const handleInteraction: RoleypolyHandler = async (
   }
 
   if (!(await verifyRequest(context.config, request, interaction))) {
+    console.warn('interactions: invalid signature');
     return new Response('invalid request signature', { status: 401 });
   }
 
   if (interaction.type !== InteractionType.APPLICATION_COMMAND) {
     if (interaction.type === InteractionType.PING) {
+      console.info('interactions: ping');
       return json({ type: InteractionCallbackType.PONG });
     }
 
+    console.warn('interactions: not application command');
     return json({ err: 'not implemented' }, { status: 400 });
   }
 

packages/api/src/utils/response.ts

@@ -17,7 +17,7 @@ export const corsHeaders = {
   'Access-Control-Max-Age': '86400',
 };
 
-export const noContent = () => new Response(null, { status: 204 });
+export const noContent = () => new Response(null, { status: 204, headers: corsHeaders });
 export const seeOther = (url: string) =>
   new Response(
     `<!doctype html>If you are not redirected soon, <a href="${url}">click here.</a>`,

terraform/interactions.tf

@@ -0,0 +1,5 @@
+resource "discord-interactions_guild_command" "hello-world" {
+  name        = "hello-world"
+  description = "Says hello!"
+  guild_id    = "386659935687147521"
+}