libsignal/swift/Sources/LibSignalClient/PrivateKey.swift

//
// Copyright 2020-2022 Signal Messenger, LLC.
// SPDX-License-Identifier: AGPL-3.0-only
//

import Foundation
import SignalFfi

public class PrivateKey: ClonableHandleOwner<SignalMutPointerPrivateKey>, @unchecked Sendable {
    public convenience init<Bytes: ContiguousBytes>(_ bytes: Bytes) throws {
        let handle = try bytes.withUnsafeBorrowedBuffer {
            var result = SignalMutPointerPrivateKey()
            try checkError(signal_privatekey_deserialize(&result, $0))
            return result
        }
        self.init(owned: NonNull(handle)!)
    }

    public static func generate() -> PrivateKey {
        return failOnError {
            try invokeFnReturningNativeHandle {
                signal_privatekey_generate($0)
            }
        }
    }

    override internal class func cloneNativeHandle(
        _ newHandle: inout SignalMutPointerPrivateKey,
        currentHandle: SignalConstPointerPrivateKey
    ) -> SignalFfiErrorRef? {
        return signal_privatekey_clone(&newHandle, currentHandle)
    }

    override internal class func destroyNativeHandle(
        _ handle: NonNull<SignalMutPointerPrivateKey>
    ) -> SignalFfiErrorRef? {
        return signal_privatekey_destroy(handle.pointer)
    }

    public func serialize() -> Data {
        return withNativeHandle { nativeHandle in
            failOnError {
                try invokeFnReturningData {
                    signal_privatekey_serialize($0, nativeHandle.const())
                }
            }
        }
    }

    public func generateSignature<Bytes: ContiguousBytes>(message: Bytes) -> Data {
        return withNativeHandle { nativeHandle in
            message.withUnsafeBorrowedBuffer { messageBuffer in
                failOnError {
                    try invokeFnReturningData {
                        signal_privatekey_sign($0, nativeHandle.const(), messageBuffer)
                    }
                }
            }
        }
    }

    public func keyAgreement(with other: PublicKey) -> Data {
        return failOnError {
            try withAllBorrowed(self, other) { nativeHandle, otherHandle in
                try invokeFnReturningData {
                    signal_privatekey_agree($0, nativeHandle.const(), otherHandle.const())
                }
            }
        }
    }

    public var publicKey: PublicKey {
        return withNativeHandle { nativeHandle in
            failOnError {
                try invokeFnReturningNativeHandle {
                    signal_privatekey_get_public_key($0, nativeHandle.const())
                }
            }
        }
    }
}

extension SignalMutPointerPrivateKey: SignalMutPointer {
    public typealias ConstPointer = SignalConstPointerPrivateKey

    public init(untyped: OpaquePointer?) {
        self.init(raw: untyped)
    }

    public func toOpaque() -> OpaquePointer? {
        self.raw
    }

    public func const() -> SignalConstPointerPrivateKey {
        SignalConstPointerPrivateKey(raw: self.raw)
    }
}

extension SignalConstPointerPrivateKey: SignalConstPointer {
    public func toOpaque() -> OpaquePointer? {
        self.raw
    }
}