Sure, sounds good. Webrev is updated in place at webrev.01 since the change is just one-line.

Will proceed with integration once the mach5 tests finish.

Thanks!
Valerie
On 6/14/2020 2:21 AM, Weijun Wang wrote:
Looks fine to me. Maybe you can also use "if (this instanceof Cloneable)" in 
Signature$Delegate::clone.

Thanks,
Max

On Jun 11, 2020, at 3:45 AM, Valerie Peng <valerie.p...@oracle.com> wrote:

Webrev updated at: http://cr.openjdk.java.net/~valeriep/8246077/webrev.01/

Key changes in this revision are in the Delegate.of() method in 
java.security.MessageDigest class.

Comments?

Thanks,
Valerie
On 6/8/2020 1:42 PM, Valerie Peng wrote:
"md instanceof Cloneable && md is not from PKCS11" is not entirely precise. 
What I mean is that for MessageDigestSpi impls from PKCS11 provider, we will need to call the 
clone() to know for sure whether cloning is supported. If we decide to employ these extra logic 
for saving clone() call, it's better to do it inside the MessageDigest.of(...) so the callers 
don't have to repeat the same logic. Comments?

Valerie

On 6/8/2020 1:34 PM, Valerie Peng wrote:
Hmm, I checked all MessageDigestSpi impls of JDK providers... The story is more 
complicated than we expect.

For SUN provider which implement the digest spi, implementing Cloneable means 
it supports clone functionality.

However, for SunPKCS11 provider which wraps native PKCS11 library, it always 
implements Cloneable interface, but when clone() is called, it will then 
perform the equivalent PKCS11 calls and throw CNSE if any PKCS11 error is 
observed.

So, there is a possibility that the instanceof check and the clone() check 
leads to different result in this particular scenario.

The chance of 3rd non-PKCS11 party provider whose MessageDigest/MessageDigestSpi impl implements 
Cloneable but throws CNSE when clone() is called should be very low? So, I think it should be 
sufficient to use "md instanceof Cloneable && md is not from PKCS11"?

Valerie

On 6/6/2020 9:10 AM, Xuelei Fan wrote:
As the the Delegate class takes care of the Cloneable SPI implementation, it should be 
sufficient to use "md instanceof Cloneable" only.  It is not a expected 
behavior that a provider implements Cloneable but does not really support it.

Xuelei

On 6/5/2020 10:54 PM, Weijun Wang wrote:
Is it possible to try "md instanceof Cloneable || md.clone() returns"? 
Hopefully this is fast enough in most cases and also has the chance to recognize more 
actually-cloneable ones.

I'm also OK with simply using "md instanceof Cloneable".

--Max

On Jun 6, 2020, at 12:02 PM, Valerie Peng <valerie.p...@oracle.com> wrote:


I am merely following the spec's recommendation of trying the clone() for 
cloneability check.

If you both are ok with it and prefer the instanceof check, I can sure 
reverting back the changes in HmacCore and HandshakeHash classes.

Valerie

On 6/5/2020 2:04 AM, Seán Coffey wrote:
I share the same concern. clone() is a heavy weight operation in constructors 
that can be called alot during intensive crypto operations.

Now that you've done work on Delegate class - why not also keep the (instanceof 
Cloneable) test ? That can serve as your fastpath for the default JDK 
configuration AFAIK.

regards,
Sean.

On 05/06/2020 00:16, Weijun Wang wrote:
在 2020年6月5日,03:19,Valerie Peng <valerie.p...@oracle.com> 写道:

Can you give an example when these 2 rules have different results? Is this only 
true for those implementation that directly subclass MessageDigest?
Before this fix, even the Spi impl implements Cloneable the instanceof check 
will always fail because the wrapper class, i.e. MessageDigest.Delegate does 
not. However, if you call the clone() (made public by the MessageDigest class), 
it will succeed because Delegate.clone() checks to see if the spi object 
implements the Cloneable interface, if yes, it will proceed to call the spi 
clone(). So, for this scenario, the results are different, e.g. instanceof 
returns false, but clone() succeeds. This is just one example. Is this what you 
are asking?
No.

I understand this case, but this has already been fixed. Is there any other 
example? Or are you only follow the words in the spec? i.e. try clone() to see 
if it’s cloneable.

I am worried that try clone() is much heavier than just check instanof 
Cloneable.

Thanks,
Max

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