import CommonCrypto
import Foundation

func pbkdf2(hash: CCPBKDFAlgorithm, password: String, salt: Data, keyByteCount: Int, rounds: Int) -> Data? {
    let passwordData = password.data(using: String.Encoding.utf8)!
    var derivedKeyData = Data(repeating: 0, count: keyByteCount)
    let derivedKeyDataCount = derivedKeyData.count
    let derivationStatus = derivedKeyData.withUnsafeMutableBytes { derivedKeyBytes in
        salt.withUnsafeBytes { saltBytes in
            CCKeyDerivationPBKDF(
                CCPBKDFAlgorithm(kCCPBKDF2),
                password, passwordData.count,
                saltBytes, salt.count,
                hash,
                UInt32(rounds),
                derivedKeyBytes, derivedKeyDataCount
            )
        }
    }

    if derivationStatus != 0 {
        print("Error: \(derivationStatus)")
        return nil
    }

    return derivedKeyData
}