CBCBlockCipherMac.fromCipher constructor
      
      CBCBlockCipherMac.fromCipher(
    
- BlockCipher cipher
create a standard MAC based on a CBC block cipher. This will produce an authentication code half the length of the block size of the cipher.
- cipherthe cipher to be used as the basis of the MAC generation.
Implementation
CBCBlockCipherMac.fromCipher(BlockCipher cipher)
    : this(cipher, (cipher.blockSize * 8) ~/ 2, null);