feat: add support for zcash NU6_1 branch

Add support for Zcash NU6_1 branch as specified in ZIP-0255. Update
default transaction version to use NU6_1 for both mainnet and testnet.

Co-authored-by: llm-git <[email protected]>

Ticket: BTC-2374

TICKET: BTC-2374

Author: lcovar

modules/utxo-lib/src/bitgo/transaction.ts

@@ -154,10 +154,10 @@ export function createPsbtFromTransaction(tx: UtxoTransaction<bigint>, prevOuts:
 }
 
 export function getDefaultTransactionVersion(network: Network): number {
-  // Use NU6 version for testnet, activated on mainnet in block 2726400
-  // https://zips.z.cash/zip-0253
-  if (network === networks.zcashTest) {
-    return ZcashTransaction.VERSION4_BRANCH_NU6;
+  // Use NU6_1 version for both mainnet and testnet
+  // https://zips.z.cash/zip-0255
+  if (network === networks.zcash || network === networks.zcashTest) {
+    return ZcashTransaction.VERSION4_BRANCH_NU6_1;
   }
 
   switch (getMainnet(network)) {
@@ -166,8 +166,6 @@ export function getDefaultTransactionVersion(network: Network): number {
     case networks.bitcoingold:
     case networks.ecash:
       return 2;
-    case networks.zcash:
-      return ZcashTransaction.VERSION4_BRANCH_NU6;
     default:
       return 1;
   }
@@ -218,8 +216,10 @@ export function setPsbtDefaults(
           ZcashTransaction.VERSION4_BRANCH_CANOPY,
           ZcashTransaction.VERSION4_BRANCH_NU5,
           ZcashTransaction.VERSION4_BRANCH_NU6,
+          ZcashTransaction.VERSION4_BRANCH_NU6_1,
           ZcashTransaction.VERSION5_BRANCH_NU5,
           ZcashTransaction.VERSION5_BRANCH_NU6,
+          ZcashTransaction.VERSION5_BRANCH_NU6_1,
         ].includes(version)
       ) {
         throw new Error(`invalid version`);

modules/utxo-lib/src/bitgo/zcash/ZcashPsbt.ts

@@ -108,11 +108,13 @@ export class ZcashPsbt extends UtxoPsbt<ZcashTransaction<bigint>> {
       case ZcashTransaction.VERSION4_BRANCH_CANOPY:
       case ZcashTransaction.VERSION4_BRANCH_NU5:
       case ZcashTransaction.VERSION4_BRANCH_NU6:
+      case ZcashTransaction.VERSION4_BRANCH_NU6_1:
         this.setVersion(4);
         break;
       case 5:
       case ZcashTransaction.VERSION5_BRANCH_NU5:
       case ZcashTransaction.VERSION5_BRANCH_NU6:
+      case ZcashTransaction.VERSION5_BRANCH_NU6_1:
         this.setVersion(5);
         break;
       default:

modules/utxo-lib/src/bitgo/zcash/ZcashTransaction.ts

@@ -24,6 +24,7 @@ const OVERWINTER_BRANCH_ID = 0x5ba81b19;
 const CANOPY_BRANCH_ID = 0xe9ff75a6;
 const NU5_BRANCH_ID = 0xc2d6d0b4;
 const NU6_BRANCH_ID = 0xc8e71055;
+const NU6_1_BRANCH_ID = 0x4dec4df0; // https://zips.z.cash/zip-0255
 
 export class UnsupportedTransactionError extends Error {
   constructor(message: string) {
@@ -36,15 +37,25 @@ export function getDefaultVersionGroupIdForVersion(version: number): number {
     case 400:
     case 450:
     case 455:
+    case 456:
       return SAPLING_VERSION_GROUP_ID;
     case 500:
     case 550:
+    case 551:
       return ZIP225_VERSION_GROUP_ID;
   }
   throw new Error(`no value for version ${version}`);
 }
 
 export function getDefaultConsensusBranchIdForVersion(network: ZcashNetwork, version: number): number {
+  // Use NU6.1 version for testnet, activated on mainnet in block 2726400
+  // https://zips.z.cash/zip-0255
+  if (network === networks.zcashTest) {
+    if (version === 4 || version === 5) {
+      return NU6_1_BRANCH_ID;
+    }
+  }
+
   switch (version) {
     case 1:
     case 2:
@@ -59,12 +70,16 @@ export function getDefaultConsensusBranchIdForVersion(network: ZcashNetwork, ver
       // https://zips.z.cash/zip-0252
       // NU5 is deprecated on mainnet on block 2726400
       return NU5_BRANCH_ID;
-    case 4:
-    case 5:
     case ZcashTransaction.VERSION4_BRANCH_NU6:
     case ZcashTransaction.VERSION5_BRANCH_NU6:
+    case 4:
+    case 5:
       // https://zips.z.cash/zip-0253
       return NU6_BRANCH_ID;
+    case ZcashTransaction.VERSION4_BRANCH_NU6_1:
+    case ZcashTransaction.VERSION5_BRANCH_NU6_1:
+      // https://zips.z.cash/zip-0255
+      return NU6_1_BRANCH_ID;
   }
   throw new Error(`no value for version ${version}`);
 }
@@ -77,8 +92,10 @@ export class ZcashTransaction<TNumber extends number | bigint = number> extends
   static VERSION4_BRANCH_CANOPY = 400;
   static VERSION4_BRANCH_NU5 = 450;
   static VERSION4_BRANCH_NU6 = 455;
+  static VERSION4_BRANCH_NU6_1 = 456;
   static VERSION5_BRANCH_NU5 = 500;
   static VERSION5_BRANCH_NU6 = 550;
+  static VERSION5_BRANCH_NU6_1 = 551;
 
   // 1 if the transaction is post overwinter upgrade, 0 otherwise
   overwintered = 0;

modules/utxo-lib/src/bitgo/zcash/ZcashTransactionBuilder.ts

@@ -73,11 +73,13 @@ export class ZcashTransactionBuilder<TNumber extends number | bigint = number> e
       case ZcashTransaction.VERSION4_BRANCH_CANOPY:
       case ZcashTransaction.VERSION4_BRANCH_NU5:
       case ZcashTransaction.VERSION4_BRANCH_NU6:
+      case ZcashTransaction.VERSION4_BRANCH_NU6_1:
         this.setVersion(4);
         break;
       case 5:
       case ZcashTransaction.VERSION5_BRANCH_NU5:
       case ZcashTransaction.VERSION5_BRANCH_NU6:
+      case ZcashTransaction.VERSION5_BRANCH_NU6_1:
         this.setVersion(5);
         break;
       default:

modules/utxo-lib/test/bitgo/psbt/ZcashPsbt.ts

@@ -29,7 +29,7 @@ describe('Zcash PSBT', function () {
         assert.deepStrictEqual(psbt.toHex(), psbt.toBuffer().toString('hex'));
       });
     }
-    [400, 450, 455, 500, 550].forEach((version) => testToHexForVersion(version));
+    [400, 450, 455, 456, 500, 550, 551].forEach((version) => testToHexForVersion(version));
 
     function testFromHexForVersion(version: number) {
       it(`version ${version} should deserialize from toHex`, async function () {
@@ -39,7 +39,7 @@ describe('Zcash PSBT', function () {
         assert.deepStrictEqual(psbt2Hex, psbtHex);
       });
     }
-    [400, 450, 455, 500, 550].forEach((version) => testFromHexForVersion(version));
+    [400, 450, 455, 456, 500, 550, 551].forEach((version) => testFromHexForVersion(version));
   });
 
   describe('should be able to sign the transaction', function () {

modules/utxo-lib/test/integration_local_rpc/parse.ts

@@ -302,7 +302,7 @@ describe(`regtest fixtures`, function () {
     it('tests default version', function () {
       // FIXME(BTC-1633): fix generating fixtures for version 455 NU6
       if (networks.zcashTest === network) {
-        assert.strictEqual(getDefaultTransactionVersion(network), 455);
+        assert.strictEqual(getDefaultTransactionVersion(network), 456);
       } else {
         assert.strictEqual(allVersions.filter((v) => v === getDefaultTransactionVersion(network)).length, 1);
       }