CryptoSwift/Sources/CryptoSwift/CBCMAC.swift

//
//  CryptoSwift
//
//  Copyright (C) 2014-2017 Marcin Krzyżanowski <marcin@krzyzanowskim.com>
//  This software is provided 'as-is', without any express or implied warranty.
//
//  In no event will the authors be held liable for any damages arising from the use of this software.
//
//  Permission is granted to anyone to use this software for any purpose,including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
//
//  - The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation is required.
//  - Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
//  - This notice may not be removed or altered from any source or binary distribution.
//

public final class CBCMAC: CMAC {
  public override func authenticate(_ bytes: Array<UInt8>) throws -> Array<UInt8> {
    var inBytes = bytes
    bitPadding(to: &inBytes, blockSize: CMAC.BlockSize)
    let blocks = inBytes.batched(by: CMAC.BlockSize)

    var lastBlockEncryptionResult: [UInt8] = CBCMAC.Zero
    try blocks.forEach { block in
      let aes = try AES(key: Array(key), blockMode: CBC(iv: lastBlockEncryptionResult), padding: .noPadding)
      lastBlockEncryptionResult = try aes.encrypt(block)
    }

    return lastBlockEncryptionResult
  }
}