Merge pull request #833 from JeneaVranceanu/feat/eip712-dynamic-parsing

feat(EIP712): parsing of TypedData payload; encoding + hashing;

Author: yaroslavyaroslav

Sources/Web3Core/EthereumABI/ABIParsing.swift

@@ -7,16 +7,41 @@ import Foundation
 
 extension ABI {
 
-    public enum ParsingError: Swift.Error {
+    public enum ParsingError: LocalizedError {
         case invalidJsonFile
-        case elementTypeInvalid
+        case elementTypeInvalid(_ desc: String? = nil)
         case elementNameInvalid
         case functionInputInvalid
         case functionOutputInvalid
         case eventInputInvalid
         case parameterTypeInvalid
         case parameterTypeNotFound
         case abiInvalid
+
+        public var errorDescription: String? {
+            var errorMessage: [String?]
+            switch self {
+            case .invalidJsonFile:
+                errorMessage = ["invalidJsonFile"]
+            case .elementTypeInvalid(let desc):
+                errorMessage = ["elementTypeInvalid", desc]
+            case .elementNameInvalid:
+                errorMessage = ["elementNameInvalid"]
+            case .functionInputInvalid:
+                errorMessage = ["functionInputInvalid"]
+            case .functionOutputInvalid:
+                errorMessage = ["functionOutputInvalid"]
+            case .eventInputInvalid:
+                errorMessage = ["eventInputInvalid"]
+            case .parameterTypeInvalid:
+                errorMessage = ["parameterTypeInvalid"]
+            case .parameterTypeNotFound:
+                errorMessage = ["parameterTypeNotFound"]
+            case .abiInvalid:
+                errorMessage = ["abiInvalid"]
+            }
+            return errorMessage.compactMap { $0 }.joined(separator: " ")
+        }
     }
 
     enum TypeParsingExpressions {
@@ -39,7 +64,7 @@ extension ABI.Record {
     public func parse() throws -> ABI.Element {
         let typeString = self.type ?? "function"
         guard let type = ABI.ElementType(rawValue: typeString) else {
-            throw ABI.ParsingError.elementTypeInvalid
+            throw ABI.ParsingError.elementTypeInvalid("Invalid ABI type \(typeString).")
         }
         return try parseToElement(from: self, type: type)
     }

Sources/Web3Core/EthereumABI/ABITypeParser.swift

@@ -46,7 +46,7 @@ public struct ABITypeParser {
 
     public static func parseTypeString(_ string: String) throws -> ABI.Element.ParameterType {
         let (type, tail) = recursiveParseType(string)
-        guard let t = type, tail == nil else {throw ABI.ParsingError.elementTypeInvalid}
+        guard let t = type, tail == nil else { throw ABI.ParsingError.elementTypeInvalid("Invalid ABI type \(string).") }
         return t
     }
 

Sources/Web3Core/KeystoreManager/AbstractKeystore.swift

@@ -11,11 +11,30 @@ public protocol AbstractKeystore {
     func UNSAFE_getPrivateKeyData(password: String, account: EthereumAddress) throws -> Data
 }
 
-public enum AbstractKeystoreError: Error {
-    case noEntropyError
-    case keyDerivationError
-    case aesError
-    case invalidAccountError
+public enum AbstractKeystoreError: LocalizedError {
+    case noEntropyError(_ additionalDescription: String? = nil)
+    case keyDerivationError(_ additionalDescription: String? = nil)
+    case aesError(_ additionalDescription: String? = nil)
+    case invalidAccountError(_ additionalDescription: String? = nil)
     case invalidPasswordError
-    case encryptionError(String)
+    case encryptionError(_ additionalDescription: String? = nil)
+
+    public var errorDescription: String? {
+        var errorMessage: [String?]
+        switch self {
+        case .noEntropyError(let additionalDescription):
+            errorMessage = ["Entropy error (e.g. failed to generate a random array of bytes).", additionalDescription]
+        case .keyDerivationError(let additionalDescription):
+            errorMessage = ["Key derivation error.", additionalDescription]
+        case .aesError(let additionalDescription):
+            errorMessage = ["AES error.", additionalDescription]
+        case .invalidAccountError(let additionalDescription):
+            errorMessage = ["Invalid account error.", additionalDescription]
+        case .invalidPasswordError:
+            errorMessage = ["Invalid password error."]
+        case .encryptionError(let additionalDescription):
+            errorMessage = ["Encryption error.", additionalDescription]
+        }
+        return errorMessage.compactMap { $0 }.joined(separator: " ")
+    }
 }

Sources/Web3Core/KeystoreManager/BIP32Keystore.swift

@@ -95,11 +95,13 @@ public class BIP39 {
     }
 
     private static func entropyOf(size: Int) throws -> Data {
+        let isCorrectSize = size >= 128 && size <= 256 && size.isMultiple(of: 32)
+        let randomBytesCount = size / 8
         guard
-            size >= 128 && size <= 256 && size.isMultiple(of: 32),
-            let entropy = Data.randomBytes(length: size/8)
+            isCorrectSize,
+            let entropy = Data.randomBytes(length: randomBytesCount)
         else {
-            throw AbstractKeystoreError.noEntropyError
+            throw AbstractKeystoreError.noEntropyError("BIP39. \(!isCorrectSize ? "Requested entropy of wrong bits size: \(size). Expected: 128 <= size <= 256, size % 32 == 0." : "Failed to generate \(randomBytesCount) of random bytes.")")
         }
         return entropy
     }

Sources/Web3Core/KeystoreManager/BIP39.swift

@@ -23,13 +23,13 @@ public class EthereumKeystoreV3: AbstractKeystore {
     }
 
     public func UNSAFE_getPrivateKeyData(password: String, account: EthereumAddress) throws -> Data {
-        if self.addresses?.count == 1 && account == self.addresses?.last {
-            guard let privateKey = try? self.getKeyData(password) else {
+        if account == addresses?.last {
+            guard let privateKey = try? getKeyData(password) else {
                 throw AbstractKeystoreError.invalidPasswordError
             }
             return privateKey
         }
-        throw AbstractKeystoreError.invalidAccountError
+        throw AbstractKeystoreError.invalidAccountError("EthereumKeystoreV3. Cannot get private key: keystore doesn't contain information about given address \(account.address).")
     }
 
     // Class
@@ -77,7 +77,7 @@ public class EthereumKeystoreV3: AbstractKeystore {
         defer {
             Data.zero(&newPrivateKey)
         }
-        try encryptDataToStorage(password, keyData: newPrivateKey, aesMode: aesMode)
+        try encryptDataToStorage(password, privateKey: newPrivateKey, aesMode: aesMode)
     }
 
     public init?(privateKey: Data, password: String, aesMode: String = "aes-128-cbc") throws {
@@ -87,68 +87,60 @@ public class EthereumKeystoreV3: AbstractKeystore {
         guard SECP256K1.verifyPrivateKey(privateKey: privateKey) else {
             return nil
         }
-        try encryptDataToStorage(password, keyData: privateKey, aesMode: aesMode)
+        try encryptDataToStorage(password, privateKey: privateKey, aesMode: aesMode)
     }
 
-    fileprivate func encryptDataToStorage(_ password: String, keyData: Data?, dkLen: Int = 32, N: Int = 4096, R: Int = 6, P: Int = 1, aesMode: String = "aes-128-cbc") throws {
-        if keyData == nil {
-            throw AbstractKeystoreError.encryptionError("Encryption without key data")
+    fileprivate func encryptDataToStorage(_ password: String, privateKey: Data, dkLen: Int = 32, N: Int = 4096, R: Int = 6, P: Int = 1, aesMode: String = "aes-128-cbc") throws {
+        if privateKey.count != 32 {
+            throw AbstractKeystoreError.encryptionError("EthereumKeystoreV3. Attempted encryption with private key of length != 32. Given private key length is \(privateKey.count).")
         }
         let saltLen = 32
         guard let saltData = Data.randomBytes(length: saltLen) else {
-            throw AbstractKeystoreError.noEntropyError
+            throw AbstractKeystoreError.noEntropyError("EthereumKeystoreV3. Failed to generate random bytes: `Data.randomBytes(length: \(saltLen))`.")
         }
         guard let derivedKey = scrypt(password: password, salt: saltData, length: dkLen, N: N, R: R, P: P) else {
-            throw AbstractKeystoreError.keyDerivationError
+            throw AbstractKeystoreError.keyDerivationError("EthereumKeystoreV3. Scrypt function failed.")
         }
         let last16bytes = Data(derivedKey[(derivedKey.count - 16)...(derivedKey.count - 1)])
         let encryptionKey = Data(derivedKey[0...15])
         guard let IV = Data.randomBytes(length: 16) else {
-            throw AbstractKeystoreError.noEntropyError
+            throw AbstractKeystoreError.noEntropyError("EthereumKeystoreV3. Failed to generate random bytes: `Data.randomBytes(length: 16)`.")
         }
-        var aesCipher: AES?
-        switch aesMode {
+        var aesCipher: AES
+        switch aesMode.lowercased() {
         case "aes-128-cbc":
-            aesCipher = try? AES(key: encryptionKey.bytes, blockMode: CBC(iv: IV.bytes), padding: .noPadding)
+            aesCipher = try AES(key: encryptionKey.bytes, blockMode: CBC(iv: IV.bytes), padding: .noPadding)
         case "aes-128-ctr":
-            aesCipher = try? AES(key: encryptionKey.bytes, blockMode: CTR(iv: IV.bytes), padding: .noPadding)
+            aesCipher = try AES(key: encryptionKey.bytes, blockMode: CTR(iv: IV.bytes), padding: .noPadding)
         default:
-            aesCipher = nil
+            throw AbstractKeystoreError.aesError("EthereumKeystoreV3. AES error: given AES mode can be one of 'aes-128-cbc' or 'aes-128-ctr'. Instead '\(aesMode)' was given.")
         }
-        if aesCipher == nil {
-            throw AbstractKeystoreError.aesError
-        }
-        guard let encryptedKey = try aesCipher?.encrypt(keyData!.bytes) else {
-            throw AbstractKeystoreError.aesError
-        }
-        let encryptedKeyData = Data(encryptedKey)
-        var dataForMAC = Data()
-        dataForMAC.append(last16bytes)
-        dataForMAC.append(encryptedKeyData)
+
+        let encryptedKeyData = Data(try aesCipher.encrypt(privateKey.bytes))
+        let dataForMAC = last16bytes + encryptedKeyData
         let mac = dataForMAC.sha3(.keccak256)
         let kdfparams = KdfParamsV3(salt: saltData.toHexString(), dklen: dkLen, n: N, p: P, r: R, c: nil, prf: nil)
         let cipherparams = CipherParamsV3(iv: IV.toHexString())
         let crypto = CryptoParamsV3(ciphertext: encryptedKeyData.toHexString(), cipher: aesMode, cipherparams: cipherparams, kdf: "scrypt", kdfparams: kdfparams, mac: mac.toHexString(), version: nil)
-        guard let pubKey = Utilities.privateToPublic(keyData!) else {
-            throw AbstractKeystoreError.keyDerivationError
+        guard let publicKey = Utilities.privateToPublic(privateKey) else {
+            throw AbstractKeystoreError.keyDerivationError("EthereumKeystoreV3. Failed to derive public key from given private key. `Utilities.privateToPublic(privateKey)` returned `nil`.")
         }
-        guard let addr = Utilities.publicToAddress(pubKey) else {
-            throw AbstractKeystoreError.keyDerivationError
+        guard let addr = Utilities.publicToAddress(publicKey) else {
+            throw AbstractKeystoreError.keyDerivationError("EthereumKeystoreV3. Failed to derive address from derived public key. `Utilities.publicToAddress(publicKey)` returned `nil`.")
         }
         self.address = addr
         let keystoreparams = KeystoreParamsV3(address: addr.address.lowercased(), crypto: crypto, id: UUID().uuidString.lowercased(), version: 3)
         self.keystoreParams = keystoreparams
     }
 
     public func regenerate(oldPassword: String, newPassword: String, dkLen: Int = 32, N: Int = 4096, R: Int = 6, P: Int = 1) throws {
-        var keyData = try self.getKeyData(oldPassword)
-        if keyData == nil {
-            throw AbstractKeystoreError.encryptionError("Failed to decrypt a keystore")
+        guard var privateKey = try getKeyData(oldPassword) else {
+            throw AbstractKeystoreError.encryptionError("EthereumKeystoreV3. Failed to decrypt a keystore")
         }
         defer {
-            Data.zero(&keyData!)
+            Data.zero(&privateKey)
         }
-        try self.encryptDataToStorage(newPassword, keyData: keyData!, aesMode: self.keystoreParams!.crypto.cipher)
+        try self.encryptDataToStorage(newPassword, privateKey: privateKey, aesMode: self.keystoreParams!.crypto.cipher)
     }
 
     fileprivate func getKeyData(_ password: String) throws -> Data? {

Sources/Web3Core/KeystoreManager/EthereumKeystoreV3.swift

@@ -43,7 +43,7 @@ public class KeystoreManager: AbstractKeystore {
 
     public func UNSAFE_getPrivateKeyData(password: String, account: EthereumAddress) throws -> Data {
         guard let keystore = walletForAddress(account) else {
-            throw AbstractKeystoreError.invalidAccountError
+            throw AbstractKeystoreError.invalidAccountError("KeystoreManager: no keystore/wallet found for given address. Address `\(account.address)`.")
         }
         return try keystore.UNSAFE_getPrivateKeyData(password: password, account: account)
     }

Sources/Web3Core/KeystoreManager/KeystoreManager.swift

@@ -156,7 +156,7 @@ public struct CodableTransaction {
             let result = self.attemptSignature(privateKey: privateKey, useExtraEntropy: useExtraEntropy)
             if result { return }
         }
-        throw AbstractKeystoreError.invalidAccountError
+        throw AbstractKeystoreError.invalidAccountError("Failed to sign transaction with given private key.")
     }
 
     // actual signing algorithm implementation

Sources/Web3Core/Transaction/CodableTransaction.swift

@@ -16,6 +16,12 @@ public class EIP712 {
     public typealias Bytes = Data
 }
 
+// FIXME: this type is wrong - The minimum number of optional fields is 5, and those are
+// string name the user readable name of signing domain, i.e. the name of the DApp or the protocol.
+// string version the current major version of the signing domain. Signatures from different versions are not compatible.
+// uint256 chainId the EIP-155 chain id. The user-agent should refuse signing if it does not match the currently active chain.
+// address verifyingContract the address of the contract that will verify the signature. The user-agent may do contract specific phishing prevention.
+// bytes32 salt an disambiguating salt for the protocol. This can be used as a domain separator of last resort.
 public struct EIP712Domain: EIP712Hashable {
     public let chainId: EIP712.UInt256?
     public let verifyingContract: EIP712.Address
@@ -54,6 +60,8 @@ public extension EIP712Hashable {
                 result = ABIEncoder.encodeSingleType(type: .uint(bits: 256), value: field)!
             case is EIP712.Address:
                 result = ABIEncoder.encodeSingleType(type: .address, value: field)!
+            case let boolean as Bool:
+                result = ABIEncoder.encodeSingleType(type: .uint(bits: 8), value: boolean ? 1 : 0)!
             case let hashable as EIP712Hashable:
                 result = try hashable.hash()
             default:
@@ -64,16 +72,19 @@ public extension EIP712Hashable {
                     preconditionFailure("Not solidity type")
                 }
             }
-            guard result.count == 32 else { preconditionFailure("ABI encode error") }
+            guard result.count % 32 == 0 else { preconditionFailure("ABI encode error") }
             parameters.append(result)
         }
         return Data(parameters.flatMap { $0.bytes }).sha3(.keccak256)
     }
 }
 
-public func eip712encode(domainSeparator: EIP712Hashable, message: EIP712Hashable) throws -> Data {
-    let data = try Data([UInt8(0x19), UInt8(0x01)]) + domainSeparator.hash() + message.hash()
-    return data.sha3(.keccak256)
+public func eip712hash(domainSeparator: EIP712Hashable, message: EIP712Hashable) throws -> Data {
+    try eip712hash(domainSeparatorHash: domainSeparator.hash(), messageHash: message.hash())
+}
+
+public func eip712hash(domainSeparatorHash: Data, messageHash: Data) -> Data {
+    (Data([UInt8(0x19), UInt8(0x01)]) + domainSeparatorHash + messageHash).sha3(.keccak256)
 }
 
 // MARK: - Additional private and public extensions with support members