Name: bsC130419 Date: 09/05/2001


java version "1.4.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta2-b77)
Java HotSpot(TM) Client VM (build 1.4.0-beta2-b77, mixed mode)

http://java.sun.com/j2se/1.4/docs/api/javax/crypto/CipherSpi.html#engineUpdate(byte[],int, int) says:
Returns: the new buffer with the result, or null if the underlying cipher is a
block cipher and the input data is too short to result in a new block.

But if I return null in engineUpdate(byte[], int, int) in my subclass (DES
algorithm implementation) that inherits from javax.crypto.CipherSpi if there no
data to return, the JCE, especialy javax.crypto.Cipher#update(byte[], int, int)
throws a java.lang.NullPointerException.

I think there is a lack in the javadoc
http://java.sun.com/j2se/1.4/docs/api/javax/crypto/CipherSpi.html#engineUpdate(byte[],int, int).

The techwriters should write better:

Returns: the new buffer with the result, or new byte[0] if the underlying cipher
is a block cipher and the input data is too short to result in a new block.

All in all it will be a good thing if Sun make the several checks that are done
in JCE more public, because it is very bad to do reverse engineering to learn
the behaivior of JCE-API. I think that are not so secret things that no one
should know.
(Review ID: 131420)
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