Root Public Key as SetupConfig (#148)

BitteProtocol · Nov 15, 2024 · 23b3ce3 · 23b3ce3
1 parent 6e8f6c0
commit 23b3ce3
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Showing 3 changed files with 13 additions and 7 deletions.
diff --git a/src/index.ts b/src/index.ts
@@ -27,13 +27,15 @@ type KeyPairString = `ed25519:${string}` | `secp256k1:${string}`;
  * @property {NearConfig} [network] - (Optional) The NEAR network configuration.
  * @property {string} [privateKey] - (Optional) The private key for the account.
  * @property {string} [derivationPath] - (Optional) The derivation path for the Ethereum account. Defaults to "ethereum,1".
+ * @property {string} [rootPublicKey] - (Optional) The root public key for the account. If not available it will be fetched from the MPC contract.
  */
 export interface SetupConfig {
   accountId: string;
   mpcContractId: string;
   network?: NearConfig;
   privateKey?: string;
   derivationPath?: string;
+  rootPublicKey?: string;
 }
 
 /**
@@ -79,7 +81,7 @@ export async function setupAdapter(args: SetupConfig): Promise<NearEthAdapter> {
     throw error;
   }
   return NearEthAdapter.fromConfig({
-    mpcContract: new MpcContract(account, mpcContractId),
+    mpcContract: new MpcContract(account, mpcContractId, args.rootPublicKey),
     derivationPath: derivationPath,
   });
 }
diff --git a/src/mpcContract.ts b/src/mpcContract.ts
@@ -44,11 +44,13 @@ interface MpcContractInterface extends Contract {
  * located in: https://github.com/near/mpc-recovery
  */
 export class MpcContract implements IMpcContract {
+  rootPublicKey: string | undefined;
   contract: MpcContractInterface;
   connectedAccount: Account;
 
-  constructor(account: Account, contractId: string) {
+  constructor(account: Account, contractId: string, rootPublicKey?: string) {
     this.connectedAccount = account;
+    this.rootPublicKey = rootPublicKey;
 
     this.contract = new Contract(account.connection, contractId, {
       changeMethods: ["sign"],
@@ -66,10 +68,12 @@ export class MpcContract implements IMpcContract {
   }
 
   deriveEthAddress = async (derivationPath: string): Promise<Address> => {
-    const rootPublicKey = await this.contract.public_key();
+    if (!this.rootPublicKey) {
+      this.rootPublicKey = await this.contract.public_key();
+    }
 
-    const publicKey = await deriveChildPublicKey(
-      najPublicKeyStrToUncompressedHexPoint(rootPublicKey),
+    const publicKey = deriveChildPublicKey(
+      najPublicKeyStrToUncompressedHexPoint(this.rootPublicKey),
       this.connectedAccount.accountId,
       derivationPath
     );

diff --git a/src/utils/kdf.ts b/src/utils/kdf.ts
@@ -10,11 +10,11 @@ export function najPublicKeyStrToUncompressedHexPoint(
   return "04" + Buffer.from(decodedKey).toString("hex");
 }
 
-export async function deriveChildPublicKey(
+export function deriveChildPublicKey(
   parentUncompressedPublicKeyHex: string,
   signerId: string,
   path: string = ""
-): Promise<string> {
+): string {
   const ec = new EC("secp256k1");
   const scalarHex = sha3_256(
     `near-mpc-recovery v0.1.0 epsilon derivation:${signerId},${path}`