feat: nip19/21 links

packages/app/src/nip6.ts

@@ -0,0 +1,39 @@
+import * as secp from "@noble/secp256k1";
+import * as bip39 from "@scure/bip39";
+import { wordlist } from "@scure/bip39/wordlists/english";
+import { HDKey } from "@scure/bip32";
+
+import { DerivationPath } from "Const";
+
+export function generateBip39Entropy(mnemonic?: string): Uint8Array {
+  try {
+    const mn = mnemonic ?? bip39.generateMnemonic(wordlist, 256);
+    return bip39.mnemonicToEntropy(mn, wordlist);
+  } catch (e) {
+    throw new Error("INVALID MNEMONIC PHRASE");
+  }
+}
+
+/**
+ * Convert hex-encoded entropy into mnemonic phrase
+ */
+export function hexToMnemonic(hex: string): string {
+  const bytes = secp.utils.hexToBytes(hex);
+  return bip39.entropyToMnemonic(bytes, wordlist);
+}
+
+/**
+ * Convert mnemonic phrase into hex-encoded private key
+ * using the derivation path specified in NIP06
+ * @param mnemonic the mnemonic-encoded entropy
+ */
+export function entropyToDerivedKey(entropy: Uint8Array): string {
+  const masterKey = HDKey.fromMasterSeed(entropy);
+  const newKey = masterKey.derive(DerivationPath);
+
+  if (!newKey.privateKey) {
+    throw new Error("INVALID KEY DERIVATION");
+  }
+
+  return secp.utils.bytesToHex(newKey.privateKey);
+}