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import { Song } from "../types/song";
const SALT = process.env.HEARDLE_SALT ?? 'changeme';
const API_URL = process.env.HEARDLE_API_URL ?? 'http://localhost:3001';
function hexToBytes(hex: string): Uint8Array {
const bytes = new Uint8Array(hex.length / 2);
for (let i = 0; i < hex.length; i += 2) {
bytes[i / 2] = parseInt(hex.slice(i, i + 2), 16);
}
return bytes;
}
async function getDailyKey(): Promise<CryptoKey> {
const enc = new TextEncoder();
const date = new Date().toISOString().split('T')[0];
const keyMaterial = await crypto.subtle.importKey(
'raw',
enc.encode(date),
'PBKDF2',
false,
['deriveKey'],
);
return crypto.subtle.deriveKey(
{ name: 'PBKDF2', salt: enc.encode(SALT), iterations: 100_000, hash: 'SHA-256' },
keyMaterial,
{ name: 'AES-GCM', length: 256 },
false,
['decrypt'],
);
}
export async function getDailySolution(): Promise<Song> {
const solutionData = await fetch(`${API_URL}/today`);
if (!solutionData.ok) {
throw new Error(`Failed to fetch solution: ${solutionData.statusText}`);
}
const { iv, tag, data } = await solutionData.json();
const key = await getDailyKey();
const ciphertext = hexToBytes(data);
const authTag = hexToBytes(tag);
const combined = new Uint8Array(ciphertext.length + authTag.length);
combined.set(ciphertext);
combined.set(authTag, ciphertext.length);
const decrypted = await crypto.subtle.decrypt(
{ name: 'AES-GCM', iv: hexToBytes(iv) },
key,
combined,
);
return JSON.parse(new TextDecoder().decode(decrypted)) as Song;
}
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