On Thu, 12 Nov 2020 20:17:39 GMT, Valerie Peng <valer...@openjdk.org> wrote:
>> checkOutputCapacity: Yes.. The method includes the offsets for the output
>> buffer, which I believe would verify that the output area in the buffer with
>> offsets is large enough.
>>
>> outWithPadding: I understand the situation and I am assuming there are
>> tests that cover this case. Given it's a generic situation.
>
> Have you tested the outWithPadding situation? Given that the existing impl
> only write out the final result, I don't think you can assume that existing
> tests cover it. I have wrote a simple test to check it if you have not done
> so, can you try it out to be sure?
>
> import java.io.PrintStream;
> import java.util.*;
> import java.security.*;
> import java.security.spec.*;
>
> import javax.crypto.*;
> import javax.crypto.spec.*;
>
> public class TestDoFinal {
>
> private static String ALGO = "AES";
> private static int BLK_SIZE = 16;
>
> public static void main(String args[]) throws Exception {
>
> byte[] in = new byte[32];
> Arrays.fill(in, (byte)8);
> KeyGenerator kg = KeyGenerator.getInstance(ALGO, "SunJCE");
> SecretKey skey = kg.generateKey();
> Cipher ci = Cipher.getInstance(ALGO + "/CBC/PKCS5Padding", "SunJCE");
> ci.init(Cipher.ENCRYPT_MODE, skey);
> int inLen = in.length - BLK_SIZE;
> byte[] out = ci.doFinal(in, 0, inLen);
> System.out.println("=> enc " + inLen + " bytes, ret " +
> (out == null? "null":(out.length + " byte")));
>
> AlgorithmParameters param = ci.getParameters();
> ci.init(Cipher.DECRYPT_MODE, skey, param);
> int rLen = ci.doFinal(out, 0, out.length, in);
> System.out.println("=> dec " + out.length + " bytes, ret " +
> rLen + " byte");
> // check if more than rLen bytes are written into 'in'
> for (int j = rLen; j < in.length; j++) {
> if (in[j] != (byte)8) {
> throw new Exception("Value check failed at index " + j);
> }
> }
> System.out.println("Test Passed");
> }
> }
I tried to fix this, and I did for this test, but there other situations with
update() that weren't working. It would take some reworking of a few common
methods during the doFinal process to handle this right. I'm going to put an
'if()" so non-GCM modes create a new buffer like it did before. It was a "nice
to have' for this rfe that can be done with future work for other mode
optimizations.
-------------
PR: https://git.openjdk.java.net/jdk/pull/411
