processBlock method
Implementation
int processBlock(ByteData input, ByteData output) {
if (input.lengthInBytes < blockSize) {
throw ArgumentError("Input buffer too short");
}
if (output.lengthInBytes < blockSize) {
throw ArgumentError("Output buffer too short");
}
_unpackBlock(input);
_encryptBlock(_workingKey);
_packBlock(output);
return blockSize;
}