fix(sdk-core): throw NeedUserSignupError when recipient has no ECDH pubkey

modules/bitgo/test/v2/unit/wallet.ts

@@ -21,6 +21,7 @@ import {
   ManageUnspentsOptions,
   MessageStandardType,
   MessageTypes,
+  NeedUserSignupError,
   PopulatedIntent,
   PrebuildTransactionOptions,
   PrebuildTransactionWithIntentOptions,
@@ -2144,6 +2145,85 @@ describe('V2 Wallet:', function () {
       getKeyNock.isDone().should.be.True();
     });
 
+    it('should throw NeedUserSignupError when recipient has no ECDH pubkey (spend permission)', async function () {
+      const userId = '456';
+      const email = 'nopubkey@sdktest.com';
+      const permissions = 'view,spend';
+      const walletPassphrase = 'bitgo1234';
+      const pub = 'Zo1ggzTUKMY5bYnDvT5mtVeZxzf2FaLTbKkmvGUhUQk';
+      const encXprv = await bitgo.encrypt({ input: 'xprv1', password: walletPassphrase });
+
+      // Server returns empty pubkey — user has not completed ECDH keychain setup
+      const getSharingKeyNock = nock(bgUrl)
+        .post('/api/v1/user/sharingkey', { email })
+        .reply(200, { userId, pubkey: '', path: 'm/999999/1/1' });
+
+      // Key fetch must succeed so decryption can proceed before the pubkey check
+      const getKeyNock = nock(bgUrl).get(`/api/v2/tbtc/key/${wallet.keyIds()[0]}`).reply(200, {
+        id: wallet.keyIds()[0],
+        pub,
+        source: 'user',
+        encryptedPrv: encXprv,
+        coinSpecific: {},
+      });
+
+      await wallet
+        .shareWallet({ email, permissions, walletPassphrase })
+        .should.be.rejectedWith(NeedUserSignupError);
+
+      getSharingKeyNock.isDone().should.be.True();
+      getKeyNock.isDone().should.be.True();
+    });
+
+    it('should throw NeedUserSignupError when recipient pubkey is missing (spend permission)', async function () {
+      const userId = '456';
+      const email = 'nopubkey@sdktest.com';
+      const permissions = 'view,spend';
+      const walletPassphrase = 'bitgo1234';
+      const pub = 'Zo1ggzTUKMY5bYnDvT5mtVeZxzf2FaLTbKkmvGUhUQk';
+      const encXprv = await bitgo.encrypt({ input: 'xprv1', password: walletPassphrase });
+
+      // Server returns no pubkey field at all
+      const getSharingKeyNock = nock(bgUrl)
+        .post('/api/v1/user/sharingkey', { email })
+        .reply(200, { userId, path: 'm/999999/1/1' });
+
+      const getKeyNock = nock(bgUrl).get(`/api/v2/tbtc/key/${wallet.keyIds()[0]}`).reply(200, {
+        id: wallet.keyIds()[0],
+        pub,
+        source: 'user',
+        encryptedPrv: encXprv,
+        coinSpecific: {},
+      });
+
+      await wallet
+        .shareWallet({ email, permissions, walletPassphrase })
+        .should.be.rejectedWith(NeedUserSignupError);
+
+      getSharingKeyNock.isDone().should.be.True();
+      getKeyNock.isDone().should.be.True();
+    });
+
+    it('should not throw NeedUserSignupError when recipient has no pubkey but permission is view-only', async function () {
+      const userId = '456';
+      const email = 'nopubkey@sdktest.com';
+      const permissions = 'view';
+
+      // No pubkey — but view-only shares do not need keychain, so should succeed
+      const getSharingKeyNock = nock(bgUrl)
+        .post('/api/v1/user/sharingkey', { email })
+        .reply(200, { userId, pubkey: '', path: 'm/999999/1/1' });
+
+      const createShareNock = nock(bgUrl)
+        .post(`/api/v2/tbtc/wallet/${wallet.id()}/share`)
+        .reply(200, {});
+
+      await wallet.shareWallet({ email, permissions });
+
+      getSharingKeyNock.isDone().should.be.True();
+      createShareNock.isDone().should.be.True();
+    });
+
     describe('OFC multi-key-user-Key Wallet Sharing', function () {
       const userId = '123';
       const email = 'shareto@sdktest.com';

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

@@ -2005,13 +2005,21 @@ export class Wallet implements IWallet {
     walletPassphrase: string | undefined,
     pubkey: string,
     path: string,
-    encryptionVersion?: EncryptionVersion
+    encryptionVersion?: EncryptionVersion,
+    recipientEmail?: string
   ): Promise<SharedKeyChain> {
     try {
       const decryptedKeychain = await this.getDecryptedKeychainForSharing(walletPassphrase);
       if (!decryptedKeychain) {
         return {};
       }
+      if (!pubkey) {
+        const recipient = recipientEmail ?? 'The recipient';
+        throw new NeedUserSignupError(
+          `${recipient} does not have an ECDH keychain set up. ` +
+            `They must log into the BitGo web application at least once before receiving a wallet share.`
+        );
+      }
       return await this.encryptPrvForUser(
         decryptedKeychain.prv,
         decryptedKeychain.pub,
@@ -2068,7 +2076,8 @@ export class Wallet implements IWallet {
         params.walletPassphrase,
         sharing.pubkey,
         sharing.path,
-        params.encryptionVersion
+        params.encryptionVersion,
+        params.email
       );
     }