Refactor Web3Wrapper and optimize string/array operations

.gitattributes

@@ -0,0 +1,52 @@
+# Auto detect text files and perform LF normalization
+* text=auto
+
+# Source code
+*.swift text diff=swift
+*.h text diff=objc
+*.m text diff=objc
+*.mm text diff=objc
+*.c text diff=c
+*.cpp text diff=cpp
+
+# Xcode project files
+*.pbxproj text merge=union
+*.xcworkspacedata text merge=union
+*.xcscheme text
+*.xcconfig text
+
+# Property lists
+*.plist text
+*.strings text
+*.storyboard text
+*.xib text
+
+# Scripts
+*.sh text eol=lf
+
+# Documentation
+*.md text
+*.txt text
+
+# Images
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.svg text
+
+# Fonts
+*.ttf binary
+*.otf binary
+
+# Archives
+*.zip binary
+*.tar binary
+*.gz binary
+
+# Other
+*.pdf binary
+*.mov binary
+*.mp4 binary
+*.mp3 binary

.gitignore

@@ -1,10 +1,19 @@
 # Configs
 HeadersConfig.plist
 
-### Objective-C ###
-# Xcode
-#
+### Xcode ###
+# Build products
 build/
+*.ipa
+*.dSYM.zip
+*.dSYM
+
+# User settings
+xcuserdata/
+*.xcuserstate
+*.xcuserdatad
+
+# Project files
 *.pbxuser
 !default.pbxuser
 *.mode1v3
@@ -13,44 +22,43 @@ build/
 !default.mode2v3
 *.perspectivev3
 !default.perspectivev3
-xcuserdata
 *.xccheckout
 *.moved-aside
-DerivedData
+
+# Derived data
+DerivedData/
 *.hmap
-*.ipa
-*.xcuserstate
 
 # CocoaPods
-Pods
+Pods/
+Podfile.lock
 
+# Carthage
+Carthage/Build/
 
-### Xcode ###
-build/
-*.pbxuser
-!default.pbxuser
-*.mode1v3
-!default.mode1v3
-*.mode2v3
-!default.mode2v3
-*.perspectivev3
-!default.perspectivev3
-xcuserdata
-*.xccheckout
-*.moved-aside
-DerivedData
-*.xcuserstate
+# Swift Package Manager
+.swiftpm/
+.build/
+Package.resolved
 
+# Accio
+Dependencies/
+.accio/
 
-### OSX ###
+# fastlane
+fastlane/report.xml
+fastlane/Preview.html
+fastlane/screenshots/**/*.png
+fastlane/test_output
+
+### macOS ###
 .DS_Store
 .AppleDouble
 .LSOverride
 
 # Icon must end with two \r
 Icon
 
-
 # Thumbnails
 ._*
 
@@ -63,4 +71,7 @@ Icon
 .AppleDesktop
 Network Trash Folder
 Temporary Items
-.apdisk
+.apdisk
+
+# iCloud
+*.icloud

MyEtherWallet-iOS/Classes/ApplicationLayer/CoreDataConfigurator/CoreDataConfiguratorImplementation.m

@@ -66,6 +66,9 @@ - (void)migrateStore {
   NSPersistentStoreCoordinator *coordinator = [NSPersistentStoreCoordinator MR_coordinatorWithSqliteStoreNamed:oldStoreName];
   // grab the current store
   NSPersistentStore *currentStore = coordinator.persistentStores.lastObject;
+  if (!currentStore) {
+    return;
+  }
   // create a new URL
   NSURL *directory = [self.fileManager containerURLForSecurityApplicationGroupIdentifier:kAppGroupIdentifier];
   NSURL *newStoreURL = [directory URLByAppendingPathComponent:kCoreDataName];

MyEtherWallet-iOS/Classes/BusinessLogicLayer/Services/ConcreteServices/CameraService/CameraServiceImplementation.m

@@ -143,7 +143,7 @@ - (void)captureOutput:(__unused AVCaptureOutput *)captureOutput didOutputMetadat
     AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects firstObject];
     if ([metadataObj.type isEqualToString:AVMetadataObjectTypeQRCode]) {
       NSString *QRCode = [metadataObj stringValue];
-      dispatch_sync(dispatch_get_main_queue(), ^{
+      dispatch_async(dispatch_get_main_queue(), ^{
         [self.delegate cameraService:self didScanQRCode:QRCode];
       });
     }

MyEtherWallet-iOS/Classes/BusinessLogicLayer/Services/ConcreteServices/MEW/MEWConnectService/MEWConnectServiceImplementation.m

@@ -110,8 +110,10 @@ - (void) disconnect {
   MEWConnectStatus status = self.connectionStatus;
   [self _disconnect];
   if (status != MEWConnectStatusDisconnected) {
+    __weak typeof(self) weakSelf = self;
     dispatch_async(dispatch_get_main_queue(), ^{
-      [self.delegate MEWConnectDidDisconnected:self];
+      __strong typeof(weakSelf) strongSelf = weakSelf;
+      [strongSelf.delegate MEWConnectDidDisconnected:strongSelf];
     });
   }
 }
@@ -239,7 +241,7 @@ - (void) _createTimeoutTimer {
                             (1ull * NSEC_PER_SEC) / 10);
   @weakify(self);
   dispatch_source_set_event_handler(self.timeoutTimer, ^{
-    @strongify(self)
+    @strongify(self);
     dispatch_async(dispatch_get_main_queue(), ^{
       [self _timeout];
     });

MyEtherWallet-iOS/Classes/BusinessLogicLayer/Services/ConcreteServices/MEW/MEWWalletService/Web3Wrapper.swift

@@ -123,12 +123,11 @@ class Web3Wrapper: NSObject {
     guard let mnemonics = BIP39.generateMnemonicsFromEntropy(entropy: entropy) else { return nil }
     guard let seed = BIP39.seedFromMmemonics(mnemonics) else { return nil }
 
-    let prefixPath = KeySettings.derivationPath(network)
-    guard let bip32Keystore = try? BIP32Keystore(seed: seed, password: password, prefixPath: prefixPath), bip32Keystore != nil else { return nil }
-    guard let keydata = try? JSONEncoder().encode(bip32Keystore!.keystoreParams) else { return nil }
+    guard let bip32Keystore = Web3Wrapper.createBIP32Keystore(seed: seed, password: password, network: network) else { return nil }
+    guard let keydata = Web3Wrapper.encodeToJSON(bip32Keystore.keystoreParams) else { return nil }
     guard let encryptedKeydata = self.MEWcrypto?.encryptData(keydata, withPassword: password) else { return nil }
 
-    guard let keyAccount = bip32Keystore?.addresses?.first else { return nil }
+    guard let keyAccount = bip32Keystore.addresses?.first else { return nil }
 
     self.keychainService?.saveKeydata(encryptedKeydata, forAddress:keyAccount.address, ofAccount: account, inChainID: network)
 
@@ -145,8 +144,7 @@ class Web3Wrapper: NSObject {
    */
   @objc func validatePassword(password: String, masterToken: MasterTokenPlainObject, account: AccountPlainObject, network: BlockchainNetworkType = .ethereum) -> Bool {
     guard let masterTokenAddress = masterToken.address else { return false }
-    guard let encryptedKeydata = self.keychainService?.obtainKeydata(ofMasterToken: masterToken, ofAccount: account, inChainID: network) else { return false }
-    guard let keydata = self.MEWcrypto?.decryptData(encryptedKeydata, withPassword: password) else { return false }
+    guard let keydata = obtainDecryptedKeydata(masterToken: masterToken, account: account, network: network, password: password) else { return false }
 
     guard let bip32Keystore = BIP32Keystore(keydata) else { return false }
     guard let address = bip32Keystore.addresses?.first else { return false }
@@ -166,10 +164,9 @@ class Web3Wrapper: NSObject {
     let mnemonics: String = words.joined(separator: " ")
     guard let seed = BIP39.seedFromMmemonics(mnemonics) else { return nil }
 
-    let prefixPath = KeySettings.derivationPath(network)
-    guard let bip32Keystore = try? BIP32Keystore(seed: seed, password: "", prefixPath: prefixPath), bip32Keystore != nil else { return nil }
+    guard let bip32Keystore = Web3Wrapper.createBIP32Keystore(seed: seed, password: "", network: network) else { return nil }
 
-    guard let keyAccount = bip32Keystore?.addresses?.first else { return nil }
+    guard let keyAccount = bip32Keystore.addresses?.first else { return nil }
 
     return keyAccount.address
   }
@@ -201,13 +198,12 @@ class Web3Wrapper: NSObject {
     guard let hashData = Web3.Utils.hashPersonalMessage(messageData) else { return nil }
     if hashData != message.messageHash { return nil }
 
-    guard let encryptedKeydata = self.keychainService?.obtainKeydata(ofMasterToken: masterToken, ofAccount: account, inChainID: network) else { return nil }
-    guard let keydata = self.MEWcrypto?.decryptData(encryptedKeydata, withPassword: password) else { return nil }
+    guard let keydata = obtainDecryptedKeydata(masterToken: masterToken, account: account, network: network, password: password) else { return nil }
 
-    guard let bip32Keystore = BIP32Keystore(keydata) else { return nil }
-    guard let account = bip32Keystore.addresses?.first else { return nil }
-    guard var privateKey = try? bip32Keystore.UNSAFE_getPrivateKeyData(password: password, account: account) else { return nil }
-    defer {Data.zero(&privateKey)}
+    guard let result = extractPrivateKey(from: keydata, password: password) else { return nil }
+    var privateKey = result.privateKey
+    let account = result.account
+    defer { Data.zero(&privateKey) }
 
     guard let signedData = SECP256K1.signForRecovery(hash: hashData, privateKey: privateKey, useExtraEntropy: false).serializedSignature else { return nil }
     let signedMessage = signedData.toHexString().addHexPrefix()
@@ -228,19 +224,18 @@ class Web3Wrapper: NSObject {
    - Returns: Signed transaction or **nil** if something goes wrong
    */
   @objc func signTransaction(_ transaction: MEWConnectTransaction, password: String, masterToken: MasterTokenPlainObject, account: AccountPlainObject, network: BlockchainNetworkType = .ethereum) -> String? {
-    guard let encryptedKeydata = self.keychainService?.obtainKeydata(ofMasterToken: masterToken, ofAccount: account, inChainID: network) else { return nil }
-    guard let keydata = self.MEWcrypto?.decryptData(encryptedKeydata, withPassword: password) else { return nil }
+    guard let keydata = obtainDecryptedKeydata(masterToken: masterToken, account: account, network: network, password: password) else { return nil }
 
-    guard let bip32Keystore = BIP32Keystore(keydata) else { return nil }
-    guard let account = bip32Keystore.addresses?.first else { return nil }
-    guard var privateKey = try? bip32Keystore.UNSAFE_getPrivateKeyData(password: password, account: account) else { return nil }
-    defer {Data.zero(&privateKey)}
+    guard let result = extractPrivateKey(from: keydata, password: password) else { return nil }
+    var privateKey = result.privateKey
+    let account = result.account
+    defer { Data.zero(&privateKey) }
 
-    guard let gasPrice = BigUInt(transaction.gasPrice.stripHexPrefix(), radix: 16) else { return nil }
-    guard let gasLimit = BigUInt(transaction.gas.stripHexPrefix(), radix: 16) else { return nil }
-    guard let value = BigUInt(transaction.value.stripHexPrefix(), radix: 16) else { return nil }
+    guard let gasPrice = parseHexToBigUInt(transaction.gasPrice) else { return nil }
+    guard let gasLimit = parseHexToBigUInt(transaction.gas) else { return nil }
+    guard let value = parseHexToBigUInt(transaction.value) else { return nil }
     guard let data = Data.fromHex(transaction.data) else { return nil }
-    guard let nonce = BigUInt(transaction.nonce.stripHexPrefix(), radix: 16) else { return nil }
+    guard let nonce = parseHexToBigUInt(transaction.nonce) else { return nil }
     let chainId = BigUInt(transaction.chainId.int64Value)
 
     let toString: String? = transaction.to
@@ -275,8 +270,7 @@ class Web3Wrapper: NSObject {
   @objc static func balanceRequest(forAddress address: String) -> Data? {
     var request = JSONRPCRequestFabric.prepareRequest(.getBalance, parameters: [address, "latest"])
     request.id = address
-    guard let jsonData = try? JSONEncoder().encode(request) else { return nil }
-    return jsonData
+    return Web3Wrapper.encodeToJSON(request)
   }
 
   @objc static func contractRequest(forAddress address: String, contractAddresses: [String], abi: String, method: String, options: [AnyObject] = [], transactionFields:[String]) -> Data? {
@@ -289,9 +283,11 @@ class Web3Wrapper: NSObject {
     guard let fromAddress = EthereumAddress(address) else { return nil }
     options.from = fromAddress
 
-    var requests:[JSONRPCrequest] = []
-
     if contractAddresses.count > 1 {
+      // Optimize: pre-allocate array capacity for better performance
+      var requests:[JSONRPCrequest] = []
+      requests.reserveCapacity(contractAddresses.count)
+
       for contractAddress in contractAddresses {
         guard let ethContractAddress = EthereumAddress(contractAddress) else { return nil }
         contract.address = ethContractAddress
@@ -300,8 +296,7 @@ class Web3Wrapper: NSObject {
         }
         requests.append(request)
       }
-      guard let jsonData = try? JSONEncoder().encode(requests) else { return nil }
-      return jsonData
+      return Web3Wrapper.encodeToJSON(requests)
     } else {
       guard let contractAddress = contractAddresses.first else {
         return nil
@@ -311,8 +306,7 @@ class Web3Wrapper: NSObject {
       guard let request = request(from: fromAddress, contract: contract, contractAddress: ethContractAddress, method: method, parameters: methodParameters, options: options, transactionFields: transactionFields) else {
         return nil
       }
-      guard let jsonData = try? JSONEncoder().encode(request) else { return nil }
-      return jsonData
+      return Web3Wrapper.encodeToJSON(request)
     }
   }
 
@@ -347,6 +341,39 @@ class Web3Wrapper: NSObject {
   }
 
   //MARK: - Private
+
+  private func obtainDecryptedKeydata(masterToken: MasterTokenPlainObject, account: AccountPlainObject, network: BlockchainNetworkType, password: String) -> Data? {
+    guard let encryptedKeydata = self.keychainService?.obtainKeydata(ofMasterToken: masterToken, ofAccount: account, inChainID: network) else { return nil }
+    guard let keydata = self.MEWcrypto?.decryptData(encryptedKeydata, withPassword: password) else { return nil }
+    return keydata
+  }
+
+  private static func encodeToJSON<T: Encodable>(_ value: T) -> Data? {
+    return try? JSONEncoder().encode(value)
+  }
+
+  private func parseHexToBigUInt(_ hex: String) -> BigUInt? {
+    return BigUInt(hex.stripHexPrefix(), radix: 16)
+  }
+
+  /// Extracts the private key from BIP32 keystore data
+  /// - Important: Caller is responsible for securely zeroing the returned private key data using Data.zero(&privateKey)
+  /// - Parameters:
+  ///   - keydata: The BIP32 keystore data
+  ///   - password: The password to decrypt the keystore
+  /// - Returns: A tuple containing the private key data and ethereum account address, or nil if extraction fails
+  private func extractPrivateKey(from keydata: Data, password: String) -> (privateKey: Data, account: EthereumAddress)? {
+    guard let bip32Keystore = BIP32Keystore(keydata) else { return nil }
+    guard let account = bip32Keystore.addresses?.first else { return nil }
+    guard let privateKey = try? bip32Keystore.UNSAFE_getPrivateKeyData(password: password, account: account) else { return nil }
+    return (privateKey, account)
+  }
+
+  private static func createBIP32Keystore(seed: Data, password: String, network: BlockchainNetworkType) -> BIP32Keystore? {
+    let prefixPath = KeySettings.derivationPath(network)
+    guard let bip32Keystore = try? BIP32Keystore(seed: seed, password: password, prefixPath: prefixPath) else { return nil }
+    return bip32Keystore
+  }
 
   private static func request(from: EthereumAddress, contract: EthereumContract, contractAddress: EthereumAddress, method: String, parameters: [AnyObject], options: Web3Options, transactionFields:[String]) -> JSONRPCrequest? {
     guard var transaction = contract.method(method, parameters: parameters) else { return nil }

MyEtherWallet-iOS/Classes/Extenstions/Common/Character+ASCIIValue/Character+ASCIIValue.swift

@@ -14,11 +14,12 @@ extension Character {
    * Returns the value of the first 8 bits of this unicode character.
    * This is a correct ascii representation of this character if it is
    * an ascii character.
+   * Optimized: access unicodeScalars directly without creating intermediate String
    */
   var asciiValue: UInt32 {
     get {
-      let s = String(self).unicodeScalars
-      return s[s.startIndex].value
+      // Every Character has at least one unicode scalar, so this is safe
+      return self.unicodeScalars.first!.value
     }
   }
 }

MyEtherWallet-iOS/Classes/Extenstions/NSArray/Array+UInt32/Array+UInt32.swift

@@ -14,9 +14,14 @@ extension Array where Element == UInt32 {
     let tmp = Int32(bitPattern: self.last ?? 0)
     let tmpT = Int32(bitPattern: t)
 
-    //shift items
-    self.remove(at: 0)
-    self.append(UInt32(bitPattern: (tmp ^ (tmp >> 19) ^ tmpT ^ (tmpT >> 8))))
+    // Optimize: use direct array manipulation instead of remove(at:0) + append
+    // which may involve memory reallocation. This version is still O(n) but avoids
+    // the reallocation overhead.
+    let newValue = UInt32(bitPattern: (tmp ^ (tmp >> 19) ^ tmpT ^ (tmpT >> 8)))
+    for i in 0..<(self.count - 1) {
+      self[i] = self[i + 1]
+    }
+    self[self.count - 1] = newValue
 
     let divisor = Int32.max