feat: modify proof of reserve calculation (#15)

* feat: modify por calculation, add tests

* feat: add unit tests for bitcoin functions related to por calculations

src/functions/bitcoin/bitcoin-functions.ts

@@ -1,3 +1,4 @@
+import { hexToBytes } from '@noble/hashes/utils';
 import {
   Address,
   OutScript,
@@ -420,17 +421,20 @@ export function getInputByPaymentTypeArray(
   });
 }
 
-export function getValueMatchingOutputFromTransaction(
+export function getScriptMatchingOutputFromTransaction(
   bitcoinTransaction: BitcoinTransaction,
-  bitcoinValue: number
-): BitcoinTransactionVectorOutput {
-  const valueMatchingTransactionOutput = bitcoinTransaction.vout.find(
-    output => output.value === bitcoinValue
+  script: Uint8Array
+): BitcoinTransactionVectorOutput | undefined {
+  return bitcoinTransaction.vout.find(output =>
+    validateScript(script, hexToBytes(output.scriptpubkey))
+  );
+}
+
+export function validateScript(script: Uint8Array, outputScript: Uint8Array): boolean {
+  return (
+    outputScript.length === script.length &&
+    outputScript.every((value, index) => value === script[index])
   );
-  if (!valueMatchingTransactionOutput) {
-    throw new Error('Could not find Value matching Input in Transaction');
-  }
-  return valueMatchingTransactionOutput;
 }
 
 export function getInputIndicesByScript(script: Uint8Array, transaction: Transaction): number[] {

src/functions/proof-of-reserve/proof-of-reserve-functions.ts

@@ -0,0 +1,67 @@
+import { Network } from 'bitcoinjs-lib';
+import { RawVault } from 'src/models/ethereum-models.js';
+
+import {
+  createTaprootMultisigPayment,
+  deriveUnhardenedPublicKey,
+  getScriptMatchingOutputFromTransaction,
+  getUnspendableKeyCommittedToUUID,
+} from '../bitcoin/bitcoin-functions.js';
+import {
+  checkBitcoinTransactionConfirmations,
+  fetchBitcoinTransaction,
+} from '../bitcoin/bitcoin-request-functions.js';
+
+export async function verifyVaultDeposit(
+  vault: RawVault,
+  attestorGroupPublicKey: Buffer,
+  bitcoinBlockchainBlockHeight: number,
+  bitcoinBlockchainAPI: string,
+  bitcoinNetwork: Network
+): Promise<boolean> {
+  try {
+    const fundingTransaction = await fetchBitcoinTransaction(
+      vault.fundingTxId,
+      bitcoinBlockchainAPI
+    );
+
+    const isFundingTransactionConfirmed = await checkBitcoinTransactionConfirmations(
+      fundingTransaction,
+      bitcoinBlockchainBlockHeight
+    );
+
+    if (!isFundingTransactionConfirmed) {
+      return false;
+    }
+
+    const unspendableKeyCommittedToUUID = deriveUnhardenedPublicKey(
+      getUnspendableKeyCommittedToUUID(vault.uuid, bitcoinNetwork),
+      bitcoinNetwork
+    );
+
+    const taprootMultisigPayment = createTaprootMultisigPayment(
+      unspendableKeyCommittedToUUID,
+      attestorGroupPublicKey,
+      Buffer.from(vault.taprootPubKey, 'hex'),
+      bitcoinNetwork
+    );
+
+    const vaultTransactionOutput = getScriptMatchingOutputFromTransaction(
+      fundingTransaction,
+      taprootMultisigPayment.script
+    );
+
+    if (!vaultTransactionOutput) {
+      return false;
+    }
+
+    if (vaultTransactionOutput.value !== vault.valueLocked.toNumber()) {
+      return false;
+    }
+
+    return true;
+  } catch (error) {
+    console.log(`Error verifying Vault Deposit: ${error}`);
+    return false;
+  }
+}

src/proof-of-reserve-handlers/proof-of-reserve-handler.ts

@@ -1,19 +1,9 @@
-import { hex } from '@scure/base';
 import { Network } from 'bitcoinjs-lib';
 
-import {
-  createTaprootMultisigPayment,
-  deriveUnhardenedPublicKey,
-  getUnspendableKeyCommittedToUUID,
-  getValueMatchingOutputFromTransaction,
-} from '../functions/bitcoin/bitcoin-functions.js';
-import {
-  checkBitcoinTransactionConfirmations,
-  fetchBitcoinBlockchainBlockHeight,
-  fetchBitcoinTransaction,
-} from '../functions/bitcoin/bitcoin-request-functions.js';
+import { deriveUnhardenedPublicKey } from '../functions/bitcoin/bitcoin-functions.js';
+import { fetchBitcoinBlockchainBlockHeight } from '../functions/bitcoin/bitcoin-request-functions.js';
+import { verifyVaultDeposit } from '../functions/proof-of-reserve/proof-of-reserve-functions.js';
 import { RawVault } from '../models/ethereum-models.js';
-import { compareUint8Arrays } from '../utilities/index.js';
 
 export class ProofOfReserveHandler {
   private bitcoinBlockchainAPI: string;
@@ -30,51 +20,6 @@ export class ProofOfReserveHandler {
     this.attestorGroupPublicKey = attestorGroupPublicKey;
   }
 
-  async verifyVaultDeposit(
-    vault: RawVault,
-    attestorGroupPublicKey: Buffer,
-    bitcoinBlockchainBlockHeight: number
-  ): Promise<boolean> {
-    try {
-      const fundingTransaction = await fetchBitcoinTransaction(
-        vault.fundingTxId,
-        this.bitcoinBlockchainAPI
-      );
-      const isFundingTransactionConfirmed = await checkBitcoinTransactionConfirmations(
-        fundingTransaction,
-        bitcoinBlockchainBlockHeight
-      );
-
-      if (!isFundingTransactionConfirmed) {
-        return false;
-      }
-
-      const vaultTransactionOutput = getValueMatchingOutputFromTransaction(
-        fundingTransaction,
-        vault.valueLocked.toNumber()
-      );
-
-      const unspendableKeyCommittedToUUID = deriveUnhardenedPublicKey(
-        getUnspendableKeyCommittedToUUID(vault.uuid, this.bitcoinNetwork),
-        this.bitcoinNetwork
-      );
-      const taprootMultisigPayment = createTaprootMultisigPayment(
-        unspendableKeyCommittedToUUID,
-        attestorGroupPublicKey,
-        Buffer.from(vault.taprootPubKey, 'hex'),
-        this.bitcoinNetwork
-      );
-
-      return compareUint8Arrays(
-        taprootMultisigPayment.script,
-        hex.decode(vaultTransactionOutput.scriptpubkey)
-      );
-    } catch (error) {
-      console.error(`Error verifying Vault Deposit: ${error}`);
-      return false;
-    }
-  }
-
   async calculateProofOfReserve(vaults: RawVault[]): Promise<number> {
     const bitcoinBlockchainBlockHeight = await fetchBitcoinBlockchainBlockHeight(
       this.bitcoinBlockchainAPI
@@ -84,12 +29,15 @@ export class ProofOfReserveHandler {
       this.attestorGroupPublicKey,
       this.bitcoinNetwork
     );
+
     const verifiedDeposits = await Promise.all(
       vaults.map(async vault => {
-        return (await this.verifyVaultDeposit(
+        return (await verifyVaultDeposit(
           vault,
           derivedAttestorGroupPublicKey,
-          bitcoinBlockchainBlockHeight
+          bitcoinBlockchainBlockHeight,
+          this.bitcoinBlockchainAPI,
+          this.bitcoinNetwork
         )) === true
           ? vault.valueLocked.toNumber()
           : 0;

tests/mocks/api.test.constants.ts

@@ -0,0 +1,17 @@
+export const TEST_REGTEST_BITCOIN_BLOCKCHAIN_API = 'https://devnet.dlc.link/electrs';
+export const TEST_TESTNET_BITCOIN_BLOCKCHAIN_API = 'https://testnet.dlc.link/electrs';
+
+export const TEST_BITCOIN_BLOCKCHAIN_FEE_RECOMMENDATION_API =
+  'https://devnet.dlc.link/electrs/fee-estimates';
+
+export const TEST_REGTEST_ATTESTOR_APIS = [
+  'https://devnet.dlc.link/attestor-1',
+  'https://devnet.dlc.link/attestor-2',
+  'https://devnet.dlc.link/attestor-3',
+];
+
+export const TEST_ETHEREUM_NODE_API = 'https://sepolia-rollup.arbitrum.io/rpc';
+export const TEST_ETHEREUM_READ_ONLY_NODE_API = 'https://sepolia-rollup.arbitrum.io/rpc';
+
+export const TEST_ETHEREUM_GITHUB_DEPLOYMENT_PLAN_ROOT_URL =
+  'https://raw.githubusercontent.com/DLC-link/dlc-solidity';

tests/mocks/attestor.test.constants.ts

@@ -0,0 +1,8 @@
+export const TEST_REGTEST_ATTESTOR_EXTENDED_GROUP_PUBLIC_KEY_1 =
+  'tpubDDqN2CmTDKaGeqXMayfCZEvjZqntifi4r1ztmRWsGuE1VE4bosR3mBKQwVaCxZcmg8R1nHDMDzDmzjoccBMgwZV1hhz51tAXVnhjABCQcwA';
+
+export const TEST_TESTNET_ATTESTOR_EXTENDED_GROUP_PUBLIC_KEY_1 =
+  'tpubDDRekL64eJJav32TLhNhG59qra7wAMaei8YMGXNiJE8ksdYrKgvaFM1XG6JrSt31W97XryScrX37RUEujjZT4qScNf8Zu1JxWj4VYkwz4rU';
+
+export const TEST_TESTNET_ATTESTOR_UNHARDENED_DERIVED_PUBLIC_KEY_1 =
+  '027eda4d625f781dcc98bf68901360fdaaacce8ed466096c1dfe4865209b28c058';