add frontend error pages

server/server.ts

@@ -28,7 +28,7 @@ app.listen(process.env.PORT, () => {
 app.post("/note/", async (req: Request<{}, {}, EncryptedNote>, res) => {
   const note = req.body;
   const savedNote = await prisma.encryptedNote.create({
-    data: { ...note, expire_time: addDays(new Date(), 14) },
+    data: { ...note, expire_time: addDays(new Date(), 30) },
   });
   res.json({
     view_url: `${process.env.FRONTEND_URL}/note/${savedNote.id}`,

webapp/src/lib/crypto/decrypt.ts

@@ -1,16 +1,16 @@
 import { AES, enc, HmacSHA256 } from 'crypto-js';
 
 // TODO: should be same source code as used in the plugin!!
-export default function decrypt(cryptData: {
+export default async function decrypt(cryptData: {
 	ciphertext: string;
 	hmac: string;
 	key: string;
-}): string {
+}): Promise<string> {
 	const hmac_calculated = HmacSHA256(cryptData.ciphertext, cryptData.key).toString();
 	const is_authentic = hmac_calculated == cryptData.hmac;
 
 	if (!is_authentic) {
-		throw Error('Cannot decrypt ciphertext with this key.');
+		throw Error('Failed HMAC check');
 	}
 	const md = AES.decrypt(cryptData.ciphertext, cryptData.key).toString(enc.Utf8);
 	return md;

webapp/src/routes/__error.svelte

@@ -2,9 +2,16 @@
 	import type { Load } from '@sveltejs/kit';
 
 	export const load: Load = ({ error, status }) => {
+		let explainText = '';
+
+		if (status == 404) {
+			explainText = `No note was found for this link. It may be that the note that was once connected to this link has expired.`;
+		}
+
 		return {
 			props: {
-				title: `${status}: ${error?.message}`
+				title: `${status}: ${error?.message}`,
+				explainText: explainText
 			}
 		};
 	};
@@ -12,8 +19,10 @@
 
 <script lang="ts">
 	export let title: string;
+	export let explainText: string;
 </script>
 
 <div class="prose max-w-2xl">
 	<h1>{title}</h1>
+	<p class="prose-xl">{explainText}</p>
 </div>

webapp/src/routes/note/[id].svelte

@@ -41,13 +41,15 @@
 	export let note: EncryptedNote;
 	let plaintext: string;
 	let timeString: string;
+	let decryptFailed = false;
 
 	onMount(() => {
 		if (browser) {
 			// Decrypt note
-			console.log(note);
 			const key = location.hash.slice(1);
-			plaintext = decrypt({ ...note, key });
+			decrypt({ ...note, key })
+				.then((value) => (plaintext = value))
+				.catch(() => (decryptFailed = true));
 		}
 	});
 
@@ -74,19 +76,28 @@
 	}
 </script>
 
-<div class="max-w-2xl mx-auto">
-	<p class="mb-4 text-sm flex justify-between text-neutral-500">
-		<span class="flex gap-1.5 items-center uppercase">
-			<span class="h-5"><IconEncrypted /></span>
-			<span>e2e encrypted | <span>Shared {timeString} ago</span></span>
-		</span>
-		<button class="flex gap-1.5 uppercase items-center">
-			<span>Raw Markdown</span>
-			<span class="h-6"><LogoMarkdown /></span>
-		</button>
-	</p>
-
-	{#if plaintext}
+{#if plaintext}
+	<div class="max-w-2xl mx-auto">
+		<p class="mb-4 text-sm flex justify-between text-neutral-500">
+			<span class="flex gap-1.5 items-center uppercase">
+				<span class="h-5"><IconEncrypted /></span>
+				<span>e2e encrypted | <span>Shared {timeString} ago</span></span>
+			</span>
+			<button class="flex gap-1.5 uppercase items-center">
+				<span>Raw Markdown</span>
+				<span class="h-6"><LogoMarkdown /></span>
+			</button>
+		</p>
 		<MarkdownRenderer {plaintext} />
-	{/if}
-</div>
+	</div>
+{/if}
+
+{#if decryptFailed}
+	<div class="prose max-w-2xl">
+		<h1>Error: Cannot decrypt file</h1>
+		<p class="prose-xl">This note could not be decrypted with this link.</p>
+		<p class="prose-xl">
+			If you think this is an error, please double check that you copied the entire URL.
+		</p>
+	</div>
+{/if}