feat(sdk-coin-zec): support redpallas mpc algorithm and reorder shiel…

modules/abstract-utxo/src/impl/zec/zec.ts

@@ -1,7 +1,7 @@
 /**
  * @prettier
  */
-import { BitGoBase } from '@bitgo/sdk-core';
+import { BitGoBase, MPCAlgorithm } from '@bitgo/sdk-core';
 import { zcashAddress } from '@bitgo/wasm-utxo';
 
 import { AbstractUtxoCoin } from '../../abstractUtxoCoin';
@@ -14,6 +14,16 @@ export class Zec extends AbstractUtxoCoin {
     super(bitgo);
   }
 
+  /**
+   * ZEC shielded (Orchard/Ironwood) custodial wallets use RedPallas threshold keys.
+   * Transparent (secp256k1 multisig) flows are unaffected: MPCAlgorithm is only
+   * consulted on the TSS custodial wallet-creation path.
+   * @inheritdoc
+   */
+  getMPCAlgorithm(): MPCAlgorithm {
+    return 'redpallas';
+  }
+
   static createInstance(bitgo: BitGoBase): Zec {
     return new Zec(bitgo);
   }

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

@@ -435,6 +435,25 @@ export class Wallets implements IWallets {
       throw new Error('EVM TSS wallets are only supported for wallet version 3, 5 and 6');
     }
 
+    // Transparent zcash wallets are multisig and isTSS is not set inherently.
+    // Shielded zcash wallets are MPC
+    if (params.isShielded) {
+      assert(enterprise, 'enterprise is required for shielded wallet');
+      if (type !== 'custodial') {
+        throw new Error('shielded wallets can only be created as custodial wallets');
+      }
+      if (params.multisigType !== 'tss') {
+        throw new Error('shielded wallets must set/use multisigType tss');
+      }
+      return this.generateCustodialMpcWallet({
+        multisigType: 'tss',
+        isShielded: true,
+        label,
+        enterprise,
+        walletVersion: params.walletVersion,
+      });
+    }
+
     if (isTss) {
       if (!this.baseCoin.supportsTss()) {
         throw new Error(`coin ${this.baseCoin.getFamily()} does not support TSS at this time`);
@@ -491,22 +510,6 @@ export class Wallets implements IWallets {
       return walletData;
     }
 
-    // Transparent zcash wallets are multisig and isTSS is not set inherently.
-    // Shielded zcash wallets are MPC
-    if (params.isShielded) {
-      assert(enterprise, 'enterprise is required for shielded wallet');
-      if (type !== 'custodial') {
-        throw new Error('shielded wallets can only be created as custodial wallets');
-      }
-      return this.generateCustodialMpcWallet({
-        multisigType: 'tss',
-        isShielded: true,
-        label,
-        enterprise,
-        walletVersion: params.walletVersion,
-      });
-    }
-
     // Handle distributed custody
     if (isDistributedCustody) {
       if (!enterprise) {