CryptoSwift/Sources/CryptoSwift/Cryptors.swift

//
//  Cryptors.swift
//  CryptoSwift
//
//  Created by Marcin Krzyzanowski on 30/08/14.
//  Copyright (c) 2014 Marcin Krzyzanowski. All rights reserved.
//

#if os(Linux) || os(Android) || os(FreeBSD)
    import Glibc
#else
    import Darwin
#endif

/// Worker cryptor/decryptor of `Updatable` types
public protocol Cryptors: class {
    associatedtype EncryptorType: Updatable
    associatedtype DecryptorType: Updatable

    /// Cryptor suitable for encryption
    func makeEncryptor() -> EncryptorType

    /// Cryptor suitable for decryption
    func makeDecryptor() -> DecryptorType

    /// Generate array of random bytes. Helper function.
    static func randomIV(_ blockSize: Int) -> Array<UInt8>
}

extension Cryptors {

    public static func randomIV(_ blockSize: Int) -> Array<UInt8> {
        var randomIV: Array<UInt8> = Array<UInt8>()
        randomIV.reserveCapacity(blockSize)
        for randomByte in RandomBytesSequence(size: blockSize) {
            randomIV.append(randomByte)
        }
        return randomIV
    }
}