doFinal abstract method
Process the last block of data given by inp and starting at offset inpOff and pad it as
explained in this interface's description.
For encryption, the resulting cipher text is put in out beginning at position outOff and
the method returns the total bytes put in out, including the padding. Note that, if inp
length is equal to the cipher's block size, out will need to be twice the cipher's block size
to allow place for the padding.
For decryption, the resulting plain text is put in out beginning at position outOff and the
method returns the total bytes put in out, excluding the padding. Note that the method may
return 0 if the last block was all padding.
Implementation
int doFinal(Uint8List inp, int inpOff, Uint8List out, int outOff);