From: Chris Duncan <chris@zoso.dev>
Date: Sat, 7 Dec 2024 21:32:48 +0000 (-0800)
Subject: Extend bip44ckd to support any specified coin as an argument. nanoCKD remains as... 
X-Git-Url: https://zoso.dev/?a=commitdiff_plain;h=1d00af326555ae94d420013581f6e90a6301c023;p=libnemo.git

Extend bip44ckd to support any specified coin as an argument. nanoCKD remains as a dedicated function for this wallet library.
---

diff --git a/src/lib/bip32-key-derivation.ts b/src/lib/bip32-key-derivation.ts
index f9014f9..886b623 100644
--- a/src/lib/bip32-key-derivation.ts
+++ b/src/lib/bip32-key-derivation.ts
@@ -18,12 +18,29 @@ type ExtendedKey = {
 * @returns {Promise<string>} Private child key for the account
 */
 export async function nanoCKD (seed: string, index: number): Promise<string> {
+	if (!Number.isSafeInteger(index) || index < 0 || index > 0x7fffffff) {
+		throw new RangeError(`Invalid child key index 0x${index.toString(16)}`)
+	}
+	return await ckd(seed, BIP44_COIN_NANO, index)
+}
+
+/**
+* Derives a private child key for a coin by following the specified BIP-32 and
+* BIP-44 derivation path. Purpose is always 44'. Only hardened child keys are
+* defined.
+*
+* @param {string} seed - Hexadecimal seed derived from mnemonic phrase
+* @param {number} coin - Number registered to a specific coin in SLIP-044
+* @param {number} index - Account number between 0 and 2^31-1
+* @returns {Promise<string>} Private child key for the account
+*/
+export async function ckd (seed: string, coin: number, index: number): Promise<string> {
 	if (!Number.isSafeInteger(index) || index < 0 || index > 0x7fffffff) {
 		throw new RangeError(`Invalid child key index 0x${index.toString(16)}`)
 	}
 	const masterKey = await slip10(SLIP10_ED25519, seed)
 	const purposeKey = await CKDpriv(masterKey, BIP44_PURPOSE + HARDENED_OFFSET)
-	const coinKey = await CKDpriv(purposeKey, BIP44_COIN_NANO + HARDENED_OFFSET)
+	const coinKey = await CKDpriv(purposeKey, coin + HARDENED_OFFSET)
 	const accountKey = await CKDpriv(coinKey, index + HARDENED_OFFSET)
 	return accountKey.privateKey
 }
diff --git a/src/lib/bip44-ckd.ts b/src/lib/bip44-ckd.ts
index c768e8b..ab1fdca 100644
--- a/src/lib/bip44-ckd.ts
+++ b/src/lib/bip44-ckd.ts
@@ -40,9 +40,26 @@ const b = () => {
 	*
 	* @param {string} seed - Hexadecimal seed derived from mnemonic phrase
 	* @param {number} index - Account number between 0 and 2^31-1
-	* @returns Private child key for the account
+	* @returns {Promise<string>} Private child key for the account
 	*/
 	async function nanoCKD (seed: string, index: number): Promise<string> {
+		if (!Number.isSafeInteger(index) || index < 0 || index > 0x7fffffff) {
+			throw new RangeError(`Invalid child key index 0x${index.toString(16)}`)
+		}
+		return await ckd(seed, BIP44_COIN_NANO, index)
+	}
+
+	/**
+	* Derives a private child key for a coin by following the specified BIP-32 and
+	* BIP-44 derivation path. Purpose is always 44'. Only hardened child keys are
+	* defined.
+	*
+	* @param {string} seed - Hexadecimal seed derived from mnemonic phrase
+	* @param {number} coin - Number registered to a specific coin in SLIP-044
+	* @param {number} index - Account number between 0 and 2^31-1
+	* @returns {Promise<string>} Private child key for the account
+	*/
+	async function ckd (seed: string, coin: number, index: number): Promise<string> {
 		if (seed.length < 32 || seed.length > 128) {
 			throw new RangeError(`Invalid seed length`)
 		}
@@ -51,7 +68,7 @@ const b = () => {
 		}
 		const masterKey = await slip10(SLIP10_ED25519, seed)
 		const purposeKey = await CKDpriv(masterKey, BIP44_PURPOSE + HARDENED_OFFSET)
-		const coinKey = await CKDpriv(purposeKey, BIP44_COIN_NANO + HARDENED_OFFSET)
+		const coinKey = await CKDpriv(purposeKey, coin + HARDENED_OFFSET)
 		const accountKey = await CKDpriv(coinKey, index + HARDENED_OFFSET)
 		const privateKey = new Uint8Array(accountKey.privateKey.buffer)
 		let hex = ''