DerivationTool.deriveUnifiedAddressFrom(ufvk)

- a new public API for DerivationTool to derive UA from the UFVK added

CHANGELOG.md

@@ -9,6 +9,7 @@ and this library adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Added
 - `DerivationTool.deriveArbitraryWalletKey`
 - `DerivationTool.deriveArbitraryAccountKey`
+- `DerivationTool.deriveUnifiedAddressFrom(ufvk)`
 - `SDKSynchronizer.listAccounts` Returns a list of the accounts in the wallet.
 - `SDKSynchronizer.importAccount` Imports a new account for unified full viewing key.
 

Sources/ZcashLightClientKit/Error/ZcashError.swift

@@ -368,6 +368,10 @@ public enum ZcashError: Equatable, Error {
     /// - `rustError` contains error generated by the rust layer.
     /// ZRUST0067
     case rustImportAccountUfvk(_ rustError: String)
+    /// Error from rust layer when calling ZcashRustBackend.deriveAddressFromUfvk
+    /// - `rustError` contains error generated by the rust layer.
+    /// ZRUST0068
+    case rustDeriveAddressFromUfvk(_ rustError: String)
     /// SQLite query failed when fetching all accounts from the database.
     /// - `sqliteError` is error produced by SQLite library.
     /// ZADAO0001
@@ -737,6 +741,7 @@ public enum ZcashError: Equatable, Error {
         case .rustDeriveArbitraryWalletKey: return "Error from rust layer when calling ZcashRustBackend.deriveArbitraryWalletKey"
         case .rustDeriveArbitraryAccountKey: return "Error from rust layer when calling ZcashRustBackend.deriveArbitraryAccountKey"
         case .rustImportAccountUfvk: return "Error from rust layer when calling ZcashRustBackend.importAccountUfvk"
+        case .rustDeriveAddressFromUfvk: return "Error from rust layer when calling ZcashRustBackend.deriveAddressFromUfvk"
         case .accountDAOGetAll: return "SQLite query failed when fetching all accounts from the database."
         case .accountDAOGetAllCantDecode: return "Fetched accounts from SQLite but can't decode them."
         case .accountDAOFindBy: return "SQLite query failed when seaching for accounts in the database."
@@ -923,6 +928,7 @@ public enum ZcashError: Equatable, Error {
         case .rustDeriveArbitraryWalletKey: return .rustDeriveArbitraryWalletKey
         case .rustDeriveArbitraryAccountKey: return .rustDeriveArbitraryAccountKey
         case .rustImportAccountUfvk: return .rustImportAccountUfvk
+        case .rustDeriveAddressFromUfvk: return .rustDeriveAddressFromUfvk
         case .accountDAOGetAll: return .accountDAOGetAll
         case .accountDAOGetAllCantDecode: return .accountDAOGetAllCantDecode
         case .accountDAOFindBy: return .accountDAOFindBy

Sources/ZcashLightClientKit/Error/ZcashErrorCode.swift

@@ -197,6 +197,8 @@ public enum ZcashErrorCode: String {
     case rustDeriveArbitraryAccountKey = "ZRUST0066"
     /// Error from rust layer when calling ZcashRustBackend.importAccountUfvk
     case rustImportAccountUfvk = "ZRUST0067"
+    /// Error from rust layer when calling ZcashRustBackend.deriveAddressFromUfvk
+    case rustDeriveAddressFromUfvk = "ZRUST0068"
     /// SQLite query failed when fetching all accounts from the database.
     case accountDAOGetAll = "ZADAO0001"
     /// Fetched accounts from SQLite but can't decode them.

Sources/ZcashLightClientKit/Error/ZcashErrorCodeDefinition.swift

@@ -390,6 +390,10 @@ enum ZcashErrorDefinition {
     /// - `rustError` contains error generated by the rust layer.
     // sourcery: code="ZRUST0067"
     case rustImportAccountUfvk(_ rustError: String)
+    /// Error from rust layer when calling ZcashRustBackend.deriveAddressFromUfvk
+    /// - `rustError` contains error generated by the rust layer.
+    // sourcery: code="ZRUST0068"
+    case rustDeriveAddressFromUfvk(_ rustError: String)
 
     // MARK: - Account DAO
 

Sources/ZcashLightClientKit/Rust/ZcashKeyDerivationBackend.swift

@@ -93,6 +93,22 @@ struct ZcashKeyDerivationBackend: ZcashKeyDerivationBackendWelding {
 
     // MARK: Address Derivation
 
+    func deriveUnifiedAddressFrom(ufvk: String) throws -> UnifiedAddress {
+        let ffiAddressPtr = zcashlc_derive_address_ufvk(
+            networkType.networkId,
+            [CChar](ufvk.utf8CString),
+            nil
+        )
+
+        guard let ffiAddressPtr else {
+            throw ZcashError.rustDeriveAddressFromUfvk(ZcashKeyDerivationBackend.lastErrorMessage(fallback: "`deriveAddressFromUfvk` failed with unknown error"))
+        }
+
+        defer { zcashlc_free_ffi_address(ffiAddressPtr) }
+
+        return ffiAddressPtr.pointee.unsafeToUnifiedAddress(networkType)
+    }
+
     func deriveUnifiedSpendingKey(
         from seed: [UInt8],
         accountIndex: Zip32AccountIndex

Sources/ZcashLightClientKit/Rust/ZcashKeyDerivationBackendWelding.swift

@@ -40,6 +40,11 @@ protocol ZcashKeyDerivationBackendWelding {
     /// - Returns: true when the encoded string is a valid UFVK. false in any other case
     func isValidUnifiedFullViewingKey(_ ufvk: String) -> Bool
 
+    /// Derives and returns a UnifiedAddress from a UnifiedFullViewingKey
+    /// - Parameter ufvk: UTF-8 encoded String to validate
+    /// - Returns: true `UnifiedAddress`
+    func deriveUnifiedAddressFrom(ufvk: String) throws -> UnifiedAddress
+
     /// Derives and returns a unified spending key from the given seed and ZIP 32 account index.
     /// Returns the binary encoding of the spending key. The caller should manage the memory of (and store, if necessary) the returned spending key in a secure fashion.
     /// - Parameter seed: a Byte Array with the seed

Sources/ZcashLightClientKit/Rust/ZcashRustBackend.swift

@@ -187,7 +187,7 @@ struct ZcashRustBackend: ZcashRustBackendWelding {
 
         let treeStateBytes = try treeState.serializedData(partial: false).bytes
 
-        var kSource: [CChar]? = nil
+        var kSource: [CChar]?
 
         if let keySource {
             kSource = [CChar](keySource.utf8CString)
@@ -1036,6 +1036,14 @@ extension String {
     }
 }
 
+extension FfiAddress {
+    /// converts an [`FfiAddress`] into a [`UnifiedAddress`]
+    /// - Note: This does not check that the converted value actually holds a valid UnifiedAddress
+    func unsafeToUnifiedAddress(_ networkType: NetworkType) -> UnifiedAddress {
+        .init(validatedEncoding: String(cString: address), networkType: networkType)
+    }
+}
+
 extension FfiAccount {
     var uuidArray: [UInt8] {
         withUnsafeBytes(of: uuid_bytes) { buf in

Sources/ZcashLightClientKit/Tool/DerivationTool.swift

@@ -17,6 +17,11 @@ public protocol KeyValidation {
 }
 
 public protocol KeyDeriving {
+    /// Derives and returns a UnifiedAddress from a UnifiedFullViewingKey
+    /// - Parameter ufvk: UTF-8 encoded String to validate
+    /// - Returns: true `UnifiedAddress`
+    func deriveUnifiedAddressFrom(ufvk: String) throws -> UnifiedAddress
+
     /// Given the seed bytes and ZIP 32 account index, return the corresponding UnifiedSpendingKey.
     /// - Parameter seed: `[Uint8]` seed bytes
     /// - Parameter accountIndex: the ZIP 32 index of the account
@@ -92,6 +97,10 @@ public class DerivationTool: KeyDeriving {
         ZcashKeyDerivationBackend.getAddressMetadata(addr)
     }
 
+    public func deriveUnifiedAddressFrom(ufvk: String) throws -> UnifiedAddress {
+        try backend.deriveUnifiedAddressFrom(ufvk: ufvk)
+    }
+
     /// Given a spending key, return the associated viewing key.
     /// - Parameter spendingKey: the `UnifiedSpendingKey` from which to derive the `UnifiedFullViewingKey` from.
     /// - Returns: the viewing key that corresponds to the spending key.