Initial Version (Working relay implementing basic functionality)

utils.ts

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+import { exists } from "jsr:@std/fs";
+import * as nostrTools from "@nostr/tools";
+import * as nip06 from "@nostr/tools/nip06";
+import { decodeBase64, encodeBase64 } from "jsr:@std/encoding@0.224/base64";
+import { getEveFilePath } from "./utils/files.ts";
+import {
+  decryptUint8Array,
+  encryptionKey,
+  encryptUint8Array,
+} from "./utils/encryption.ts";
+
+export function isLocalhost(req: Request): boolean {
+  const url = new URL(req.url);
+  const hostname = url.hostname;
+  return (
+    hostname === "127.0.0.1" || hostname === "::1" || hostname === "localhost"
+  );
+}
+
+export function isValidJSON(str: string) {
+  try {
+    JSON.parse(str);
+  } catch {
+    return false;
+  }
+  return true;
+}
+
+export function isArray<T>(obj: unknown): obj is T[] {
+  return Array.isArray(obj);
+}
+
+export function randomTimeUpTo2DaysInThePast() {
+  const now = Date.now();
+  const twoDaysAgo = now - 2 * 24 * 60 * 60 * 1000 - 3600 * 1000; // 1 hour buffer in case of clock skew
+  return Math.floor(
+    (Math.floor(Math.random() * (now - twoDaysAgo)) + twoDaysAgo) / 1000,
+  );
+}
+
+export async function getCCNPubkey(): Promise<string> {
+  const ccnPubPath = await getEveFilePath("ccn.pub");
+  const doWeHaveKey = await exists(ccnPubPath);
+  if (doWeHaveKey) return Deno.readTextFileSync(ccnPubPath);
+  const ccnSeed = Deno.env.get("CCN_SEED") || nip06.generateSeedWords();
+  const ccnPrivateKey = nip06.privateKeyFromSeedWords(ccnSeed);
+  const ccnPublicKey = nostrTools.getPublicKey(ccnPrivateKey);
+  const encryptedPrivateKey = encryptUint8Array(ccnPrivateKey, encryptionKey);
+
+  Deno.writeTextFileSync(ccnPubPath, ccnPublicKey);
+  Deno.writeTextFileSync(
+    await getEveFilePath("ccn.priv"),
+    encodeBase64(encryptedPrivateKey),
+  );
+  Deno.writeTextFileSync(await getEveFilePath("ccn.seed"), ccnSeed);
+
+  return ccnPublicKey;
+}
+
+export async function getCCNPrivateKey(): Promise<Uint8Array> {
+  const encryptedPrivateKey = Deno.readTextFileSync(
+    await getEveFilePath("ccn.priv"),
+  );
+  return decryptUint8Array(decodeBase64(encryptedPrivateKey), encryptionKey);
+}