BitGo · bhavidhingra · Jul 31, 2026
@@ -0,0 +1,231 @@
+/**
+ * SIMD-525 Verification: Cold + Custodial Durable Nonce Check
+ *
+ * Cold wallets require offline-console-vault for signing — we can't do a
+ * full end-to-end send. But we DON'T need to. The protection claim is:
+ * cold and custodial wallets use durable nonce in prebuild, which bypasses
+ * blockhash expiry entirely. We just verify the prebuild.
+ *
+ * Flow:
+ *   1. Prebuild transfer → deserialize txHex → inspect instructions
+ *   2. Find AdvanceNonceAccount instruction (System program, ix index 4)
+ *   3. Extract nonceAccount + nonceAuthority from instruction accounts
+ *   4. Verify the "recentBlockhash" field is actually a nonce value
+ *
+ * Copyright 2025, BitGo, Inc.  All Rights Reserved.
+ */
+import { BitGoAPI } from '@bitgo/sdk-api';
+import { Tsol } from '@bitgo/sdk-coin-sol';
+import { coins } from '@bitgo/statics';
+import { VersionedTransaction } from '@solana/web3.js';
+import * as bs58 from 'bs58';
+
+const path = require('path');
+const envPath = path.resolve(__dirname, '../../../.env');
+require('dotenv').config({ path: envPath });
+
+// ==================== CONFIG ====================
+const ACCESS_TOKEN = process.env.TESTNET_ACCESS_TOKEN || '';
+const ENV = 'staging';
+
+const COLD_WALLET_ID = ''; // skipped — no cold wallet available
+const CUSTODIAL_WALLET_ID = '69de2c72b12f278ab5d009701b89dc52';
+
+const RECIPIENT_ADDRESS = '2dLaAjaMWTftQrAcAjhPd6k7nJhYgPkWDctWpwYJ8sbv'; // self-transfer to avoid policy denial
+const TRANSFER_AMOUNT = '1000'; // lamports
+// =================================================
+
+// System program instruction indices
+// https://github.com/solana-labs/solana/blob/master/sdk/program/src/system_instruction.rs
+const SYSTEM_PROGRAM_ID = '11111111111111111111111111111111';
+const SYSVAR_RECENT_BLOCKHASHES = 'SysvarRecentB1ockHashes11111111111111111111';
+const ADVANCE_NONCE_ACCOUNT_IX = 4; // NOT 2 (that's Transfer)
+
+interface NonceAnalysis {
+  hasDurableNonce: boolean;
+  nonceAccount?: string;
+  nonceAuthority?: string;
+  nonceValue?: string; // the "recentBlockhash" field is actually the stored nonce
+  instructions: { type: string; program: string; accounts: string[] }[];
+}
+
+function analyzeTxHex(txHex: string): NonceAnalysis {
+  if (!txHex || txHex.length < 20) {
+    return { hasDurableNonce: false, instructions: [] };
+  }
+  try {
+    const buf = Buffer.from(txHex, 'hex');
+    const tx = VersionedTransaction.deserialize(buf);
+    const msg = tx.message as any;
+    const keys = msg.staticAccountKeys;
+
+    // recentBlockhash is raw bytes, not a PublicKey — encode to base58
+    const blockhashBytes = msg.recentBlockhash;
+    let nonceValue: string;
+    if (typeof blockhashBytes === 'string') {
+      nonceValue = blockhashBytes;
+    } else if (blockhashBytes && typeof blockhashBytes.toBase58 === 'function') {
+      nonceValue = blockhashBytes.toBase58();
+    } else {
+      nonceValue = bs58.encode(Buffer.from(blockhashBytes));
+    }
+
+    const systemIxNames: Record<number, string> = {
+      0: 'CreateAccount',
+      1: 'Assign',
+      2: 'Transfer',
+      3: 'CreateAccountWithSeed',
+      4: 'AdvanceNonceAccount',
+      5: 'WithdrawNonceAccount',
+      6: 'InitializeNonceAccount',
+    };
+
+    const instructions = msg.compiledInstructions.map((ix: any) => {
+      const program = keys[ix.programIdIndex]?.toBase58();
+      // NOTE: field is accountKeyIndexes (not accountKeyIndices)
+      const accounts = (ix.accountKeyIndexes || ix.accountKeyIndices || []).map(
+        (idx: number) => keys[idx]?.toBase58()
+      );
+      const ixType = ix.data[0];
+      const typeName = program === SYSTEM_PROGRAM_ID ? (systemIxNames[ixType] || `Unknown(${ixType})`) : `Custom`;
+      return { type: typeName, program, accounts, ixType };
+    });
+
+    // Find AdvanceNonceAccount instruction
+    // Account layout for AdvanceNonceAccount:
+    //   [0] = nonce account (writable, not signer)
+    //   [1] = SysvarRecentB1ockHashes (read-only, not signer)
+    //   [2] = nonce authority (read-only, signer)
+    const nonceIx = msg.compiledInstructions.find((ix: any) => {
+      const program = keys[ix.programIdIndex]?.toBase58();
+      return program === SYSTEM_PROGRAM_ID && ix.data[0] === ADVANCE_NONCE_ACCOUNT_IX;
+    });
+
+    if (nonceIx) {
+      const accountIdxes = nonceIx.accountKeyIndexes || nonceIx.accountKeyIndices;
+      const nonceAccount = keys[accountIdxes[0]]?.toBase58();
+      const sysvarSlot = keys[accountIdxes[1]]?.toBase58();
+      const nonceAuthority = keys[accountIdxes[2]]?.toBase58();
+
+      // Verify the sysvar account is the recent blockhashes sysvar
+      const isSysvarCorrect = sysvarSlot === SYSVAR_RECENT_BLOCKHASHES;
+
+      return {
+        hasDurableNonce: true,
+        nonceAccount,
+        nonceAuthority,
+        nonceValue,
+        instructions: instructions.map((ix: any) => ({ type: ix.type, program: ix.program, accounts: ix.accounts })),
+      };
+    }
+
+    return {
+      hasDurableNonce: false,
+      nonceValue,
+      instructions: instructions.map((ix: any) => ({ type: ix.type, program: ix.program, accounts: ix.accounts })),
+    };
+  } catch (e: any) {
+    console.log('  [analyzeTxHex] failed:', e.message);
+    return { hasDurableNonce: false, instructions: [] };
+  }
+}
+
+async function checkDurableNonce(
+  bitgo: BitGoAPI,
+  walletId: string,
+  label: string
+): Promise<{ hasDurableNonce: boolean; details?: NonceAnalysis }> {
+  console.log(`\n--- ${label} (wallet: ${walletId}) ---`);
+
+  const sol = bitgo.coin('tsol');
+  const wallet = await sol.wallets().get({ id: walletId });
+  console.log('  Type:', wallet.type());
+
+  try { await bitgo.lock(); } catch {}
+  await bitgo.unlock({ otp: '000000' });
+
+  const prebuild = await wallet.prebuildTransaction({
+    type: 'transfer',
+    recipients: [{ address: RECIPIENT_ADDRESS, amount: TRANSFER_AMOUNT }],
+  } as any);
+
+  const txHex = (prebuild as any).txHex || '';
+  const txRequestId = (prebuild as any).txRequestId;
+  console.log('  txRequestId:', txRequestId);
+  console.log('  txHex length:', txHex.length);
+
+  const analysis = analyzeTxHex(txHex);
+
+  console.log('\n  Instructions:');
+  analysis.instructions.forEach((ix, i) => {
+    console.log(`    [${i}] ${ix.type} (program: ${ix.program.slice(0, 12)}...)`);
+    ix.accounts.forEach((addr, j) => {
+      console.log(`        account[${j}]: ${addr}`);
+    });
+  });
+
+  console.log('');
+  console.log('  Nonce value (recentBlockhash field):', analysis.nonceValue || '(not extracted)');
+  console.log('  nonceAccount:', analysis.nonceAccount || '(not found)');
+  console.log('  nonceAuthority:', analysis.nonceAuthority || '(not found)');
+
+  if (analysis.hasDurableNonce) {
+    console.log('\n  ✅ USES DURABLE NONCE — protected from SIMD-525 blockhash expiry');
+    console.log('     AdvanceNonceAccount instruction found in prebuild');
+    console.log('     Tx uses nonce value instead of blockhash → bypasses expiry window');
+  } else {
+    console.log('\n  ⚠️  No AdvanceNonceAccount instruction found');
+    console.log('     This wallet type may NOT use durable nonce');
+  }
+
+  return { hasDurableNonce: analysis.hasDurableNonce, details: analysis };
+}
+
+async function main() {
+  console.log('=== SIMD-525: Durable Nonce Verification (Cold + Custodial) ===\n');
+
+  if (!ACCESS_TOKEN) {
+    console.error('No access token found. Set TESTNET_ACCESS_TOKEN in .env');
+    process.exit(1);
+  }
+
+  const bitgo = new BitGoAPI({
+    accessToken: ACCESS_TOKEN,
+    env: ENV,
+  });
+  const coin = coins.get('tsol');
+  bitgo.register(coin.name, Tsol.createInstance);
+
+  let coldResult: { hasDurableNonce: boolean } | null = null;
+  let custodialResult: { hasDurableNonce: boolean } | null = null;
+
+  // --- Check 1: Cold wallet ---
+  if (COLD_WALLET_ID) {
+    coldResult = await checkDurableNonce(bitgo, COLD_WALLET_ID, 'Cold Wallet');
+  } else {
+    console.log('\n--- Cold Wallet: SKIPPED (no cold wallet available) ---');
+  }
+
+  // --- Check 2: Custodial hot wallet ---
+  if (CUSTODIAL_WALLET_ID) {
+    custodialResult = await checkDurableNonce(bitgo, CUSTODIAL_WALLET_ID, 'Custodial Hot Wallet');
+  } else {
+    console.log('\n--- Custodial Hot Wallet: SKIPPED (set CUSTODIAL_WALLET_ID in CONFIG) ---');
+  }
+
+  // --- Summary ---
+  console.log('\n=== Summary ===');
+  if (coldResult) {
+    console.log(`  Cold wallet: ${coldResult.hasDurableNonce ? '✅ durable nonce → PROTECTED' : '⚠️ no durable nonce'}`);
+  }
+  if (custodialResult) {
+    console.log(`  Custodial hot: ${custodialResult.hasDurableNonce ? '✅ durable nonce → PROTECTED' : '⚠️ no durable nonce'}`);
+  }
+  if (!coldResult && !custodialResult) {
+    console.log('  No wallets checked — fill in wallet IDs');
+  }
+
+  console.log('\n=== Test Complete ===');
+}
+
+main().catch((e) => console.log(e));