feat(sdk-core): added OFC BitGo signing on trading accounts object

modules/express/src/clientRoutes.ts

@@ -405,6 +405,15 @@ function getWalletPwFromEnv(walletId: string): string {
   return walletPw;
 }
 
+/**
+ * Returns the wallet passphrase from the environment, or undefined if not set.
+ * Unlike getWalletPwFromEnv, this does not throw when the env variable is absent.
+ * Use this when the passphrase is optional (e.g. KMS-backed wallets).
+ */
+function findWalletPwFromEnv(walletId: string): string | undefined {
+  return process.env[`WALLET_${walletId}_PASSPHRASE`];
+}
+
 async function getEncryptedPrivKey(path: string, walletId: string): Promise<string> {
   const privKeyFile = await fs.readFile(path, { encoding: 'utf8' });
   const encryptedPrivKey = JSON.parse(privKeyFile);
@@ -631,7 +640,9 @@ export async function handleV2OFCSignPayload(
     throw new ApiResponseError(`Could not find OFC wallet ${walletId}`, 404);
   }
 
-  const walletPassphrase = bodyWalletPassphrase || getWalletPwFromEnv(wallet.id());
+  // Prefer the passphrase from the request body; fall back to the env var.
+  // If neither is present, pass undefined — signPayload() routes to KMS internally.
+  const walletPassphrase = bodyWalletPassphrase ?? findWalletPwFromEnv(wallet.id());
   const tradingAccount = wallet.toTradingAccount();
   const stringifiedPayload = typeof payload === 'string' ? payload : JSON.stringify(payload);
   const signature = await tradingAccount.signPayload({

modules/express/test/unit/typedRoutes/ofcSignPayload.ts

@@ -223,10 +223,103 @@ describe('OfcSignPayload codec tests', function () {
       const decodedResponse = assertDecode(OfcSignPayloadResponse200, result.body);
       assert.strictEqual(decodedResponse.signature, mockSignPayloadResponse.signature);
 
+      // Verify env passphrase was forwarded to signPayload
+      const signCall = mockTradingAccount.signPayload.getCall(0);
+      assert.ok(signCall, 'tradingAccount.signPayload should have been called');
+      assert.strictEqual(signCall.args[0].walletPassphrase, 'env_passphrase', 'env passphrase should be forwarded');
+
       // Cleanup environment variable
       delete process.env['WALLET_ofc-wallet-id-123_PASSPHRASE'];
     });
 
+    it('should pass undefined walletPassphrase to signPayload when no passphrase in body or env (KMS path)', async function () {
+      const requestBody = {
+        walletId: 'ofc-wallet-id-no-passphrase',
+        payload: { amount: '1000000', currency: 'USD' },
+        // no walletPassphrase
+      };
+
+      // Ensure no env var is set for this wallet
+      delete process.env['WALLET_ofc-wallet-id-no-passphrase_PASSPHRASE'];
+
+      const mockTradingAccount = {
+        signPayload: sinon.stub().resolves(mockSignPayloadResponse.signature),
+      };
+
+      const mockWallet = {
+        id: () => requestBody.walletId,
+        toTradingAccount: sinon.stub().returns(mockTradingAccount),
+      };
+
+      const walletsGetStub = sinon.stub().resolves(mockWallet);
+      const mockWallets = { get: walletsGetStub };
+      const mockCoin = { wallets: sinon.stub().returns(mockWallets) };
+      sinon.stub(BitGo.prototype, 'coin').returns(mockCoin as any);
+
+      const result = await agent
+        .post('/api/v2/ofc/signPayload')
+        .set('Authorization', 'Bearer test_access_token_12345')
+        .set('Content-Type', 'application/json')
+        .send(requestBody);
+
+      assert.strictEqual(result.status, 200);
+      const decodedResponse = assertDecode(OfcSignPayloadResponse200, result.body);
+      assert.strictEqual(decodedResponse.signature, mockSignPayloadResponse.signature);
+
+      // signPayload must be called with walletPassphrase=undefined so the SDK routes to KMS
+      const signCall = mockTradingAccount.signPayload.getCall(0);
+      assert.ok(signCall, 'tradingAccount.signPayload should have been called');
+      assert.strictEqual(
+        signCall.args[0].walletPassphrase,
+        undefined,
+        'walletPassphrase should be undefined to trigger KMS signing'
+      );
+    });
+
+    it('should prefer body walletPassphrase over env passphrase', async function () {
+      const requestBody = {
+        walletId: 'ofc-wallet-id-123',
+        payload: { amount: '500' },
+        walletPassphrase: 'body_passphrase',
+      };
+
+      // Set a different env passphrase — body should win
+      process.env['WALLET_ofc-wallet-id-123_PASSPHRASE'] = 'env_passphrase';
+
+      const mockTradingAccount = {
+        signPayload: sinon.stub().resolves(mockSignPayloadResponse.signature),
+      };
+
+      const mockWallet = {
+        id: () => requestBody.walletId,
+        toTradingAccount: sinon.stub().returns(mockTradingAccount),
+      };
+
+      const walletsGetStub = sinon.stub().resolves(mockWallet);
+      const mockWallets = { get: walletsGetStub };
+      const mockCoin = { wallets: sinon.stub().returns(mockWallets) };
+      sinon.stub(BitGo.prototype, 'coin').returns(mockCoin as any);
+
+      const result = await agent
+        .post('/api/v2/ofc/signPayload')
+        .set('Authorization', 'Bearer test_access_token_12345')
+        .set('Content-Type', 'application/json')
+        .send(requestBody);
+
+      assert.strictEqual(result.status, 200);
+
+      // body passphrase should take precedence
+      const signCall = mockTradingAccount.signPayload.getCall(0);
+      assert.ok(signCall, 'tradingAccount.signPayload should have been called');
+      assert.strictEqual(
+        signCall.args[0].walletPassphrase,
+        'body_passphrase',
+        'body passphrase should take precedence over env'
+      );
+
+      delete process.env['WALLET_ofc-wallet-id-123_PASSPHRASE'];
+    });
+
     it('should successfully sign complex nested JSON payload', async function () {
       const requestBody = {
         walletId: 'ofc-wallet-id-123',

modules/sdk-core/src/bitgo/trading/iTradingAccount.ts

@@ -1,8 +1,16 @@
 import { ITradingNetwork } from './network';
 
+/**
+ * Parameters for the signing a payload from the trading account.
+ * If both walletPassphrase and prv is not provided the BitGo key will be used
+ * @param payload - The payload to sign
+ * @param walletPassphrase - The passphrase of the wallet that will be used to decrypt the user key and sign the payload.
+ * @param prv - The decrypted user key prv used to sign the payload
+ */
 export interface SignPayloadParameters {
   payload: string | Record<string, unknown>;
-  walletPassphrase: string;
+  walletPassphrase?: string;
+  prv?: string;
 }
 
 export interface ITradingAccount {

modules/sdk-core/src/bitgo/trading/network/network.ts

@@ -109,7 +109,7 @@ export class TradingNetwork implements ITradingNetwork {
 
   /**
    * Prepare an allocation for submission
-   * @param {string} walletPassphrase ofc wallet passphrase
+   * @param {string} walletPassphrase ofc wallet passphrase - required only when signing via user key
    * @param {string} connectionId connection to whom to make the allocation or deallocation
    * @param {string=} clientExternalId one time generated uuid v4
    * @param {string} currency currency for which the allocation should be made. e.g. btc / tbtc
@@ -130,10 +130,7 @@ export class TradingNetwork implements ITradingNetwork {
     }
 
     const payload = JSON.stringify(body);
-
-    const prv = await this.wallet.getPrv({ walletPassphrase });
-    const signedBuffer: Buffer = await this.wallet.baseCoin.signMessage({ prv }, payload);
-    const signature = signedBuffer.toString('hex');
+    const signature = await this.wallet.toTradingAccount().signPayload({ payload, walletPassphrase });
 
     return {
       ...body,

modules/sdk-core/src/bitgo/trading/network/types.ts

@@ -125,7 +125,7 @@ export type GetNetworkAllocationByIdResponse = {
 };
 
 export type PrepareNetworkAllocationParams = Omit<CreateNetworkAllocationParams, 'payload' | 'signature'> & {
-  walletPassphrase: string;
+  walletPassphrase?: string;
   clientExternalId?: string;
   nonce?: string;
 };

modules/sdk-core/src/bitgo/trading/tradingAccount.ts

@@ -23,18 +23,72 @@ export class TradingAccount implements ITradingAccount {
   }
 
   /**
-   * Signs an arbitrary payload with the user key on this trading account
+   * Signs an arbitrary payload. Use the user key if passphrase/prv is provided, or the BitGo key if not.
    * @param params
    * @param params.payload arbitrary payload object (string | Record<string, unknown>)
    * @param params.walletPassphrase passphrase on this trading account, used to unlock the account user key
+   * @param params.prv user private key, used to sign the payload locally
    * @returns hex-encoded signature of the payload
    */
   async signPayload(params: SignPayloadParameters): Promise<string> {
-    const key = (await this.wallet.baseCoin.keychains().get({ id: this.wallet.keyIds()[0] })) as any;
-    const prv = this.wallet.bitgo.decrypt({
-      input: key.encryptedPrv,
-      password: params.walletPassphrase,
-    });
+    // if no passphrase is provided, attempt to sign using the wallet's bitgo key remotely
+    if (!params.walletPassphrase && !params.prv) {
+      return this.signPayloadByBitGoKey(params);
+    }
+    // if a passphrase is provided, we must be trying to sign using the user private key - decrypt and sign locally
+    return this.signPayloadByUserKey(params);
+  }
+
+  /**
+   * Signs the payload of a trading account via the trading account BitGo key
+   * @param params
+   * @private
+   */
+  private async signPayloadByBitGoKey(
+    params: Omit<SignPayloadParameters, 'walletPassphrase' | 'prv'>
+  ): Promise<string> {
+    const walletData = this.wallet.toJSON();
+    if (walletData.userKeySigningRequired) {
+      throw new Error(
+        'Wallet must use user key to sign ofc transaction, please provide the wallet passphrase or visit your wallet settings page to configure one.'
+      );
+    }
+    if (walletData.keys.length < 2) {
+      throw new Error(
+        'Wallet does not support BitGo signing. Please reach out to support@bitgo.com to resolve this issue.'
+      );
+    }
+
+    // we do not parse the payload here, we instead sends the payload as a stringified JSON to be signed, just like how we process it locally
+    const url = this.wallet.url('/tx/sign');
+    const payload = typeof params.payload !== 'string' ? JSON.stringify(params.payload) : params.payload;
+    const { signature } = await this.wallet.bitgo.post(url).send({ payload }).result();
+
+    return signature;
+  }
+
+  /**
+   * Signs the payload of a trading account locally by fetching the user's encrypted private key and decrypt using passphrase
+   * @param params
+   * @private
+   */
+  private async signPayloadByUserKey(params: SignPayloadParameters): Promise<string> {
+    if (!params.prv && !params.walletPassphrase) {
+      throw new Error(
+        'Must provide either prv or walletPassphrase to sign payload using user key. Please provide the wallet passphrase or visit your wallet settings page to configure one.'
+      );
+    }
+
+    let prv: string;
+    if (params.prv) {
+      prv = params.prv;
+    } else {
+      const key = (await this.wallet.baseCoin.keychains().get({ id: this.wallet.keyIds()[0] })) as any;
+      prv = this.wallet.bitgo.decrypt({
+        input: key.encryptedPrv,
+        password: params.walletPassphrase,
+      });
+    }
     const payload = typeof params.payload === 'string' ? params.payload : JSON.stringify(params.payload);
     return ((await this.wallet.baseCoin.signMessage({ prv }, payload)) as any).toString('hex');
   }

modules/sdk-core/src/bitgo/wallet/iWallet.ts

@@ -909,6 +909,7 @@ export interface WalletData {
   evmKeyRingReferenceWalletId?: string;
   isParent?: boolean;
   enabledChildChains?: string[];
+  userKeySigningRequired?: boolean;
 }
 
 export interface RecoverTokenOptions {