cipher.update and cipher.final can output in 'hex' encoding, this add a lot ease when convert encryption results into buffer.
But decipher.update and decipher.final don't support 'hex' encoding. When use decipher to decrypt a buffer into a result buffer. The currently way is use its default 'binary' output, and convert the output string into buffer by the Buffer's 'binary' encoding.
But 'binary' encoding of Buffer is deprecated, and should avoid use as possible.
Thus, I suggest to add 'hex' output encoding option into decipher.update and decipher.final
Because of backward compatibility, there should be a new pseudo-encoding "buffer" for methods like hash#digest(), hmac#digest(), hmac#digest(), cipher#final() which should output real Buffer object.
hex is now supported.