RFR JDK-8206925,,Support the certificate_authorities extension

[Xuelei Fan]

On 5/22/2020 11:17 AM, Sean Mullan wrote:
> On 5/22/20 1:55 PM, Xuelei Fan wrote:
>>> * test/jdk/sun/security/ssl/X509TrustManagerImpl/TooMuchCAs.java
>>>
>>> Will this test FAIL if we ever exceed the maximum number of CAs? I 
>>> think it is important that it does FAIL, as the extension is 
>>> effectively not working anymore and could cause compatibility issues. 
>>> I even think we would need to try to think of some way to fix it, 
>>> either by seeing if some CAs could be excluded - not really sure, 
>>> hopefully it won't ever happen but we would want to know about it in 
>>> advance.
>>>
>> Alexey (from azul) and I discussed the idea to control the number of 
>> CAs.  However, there are still some issues in practice.
>>
>> "If the certificate authorities can not be fully listed, it cannot be 
>> used to indicate the peer certificate selection accuracy.  For 
>> example, client support A, B and C, and is only able to indicate A and 
>> B.  If the server supports C, the connection cannot be established 
>> with this extension. This is not the expected behavior.  Maybe, it is 
>> no worse than without this extension. "
>>
>> It looks like safer that the extension is not used if the size exceed 
>> the limit, at least there ARE less compatibility issues.  I have a 
>> note in the CSR and release note for the behaviors.
>>
>> The test case, TooMuchCAs, is used to make sure the connection can be 
>> established when the CAs size exceed the limit (no extension used).
> 
> Sure, I agree that is the best behavior. I guess my point is that if we 
> ever really exceed the maximum number of CAs in the cacerts keystore, it 
> would be good to have a test that will fail because of that. Minimally, 
> this would allow us to publish a release note warning users that the CA 
> extension will no longer work unless some roots are removed.
> 
Good point.  It is useful to have a test case to check the size limit of 
the cacert keystore.  A new test case, CacertsLimit.java, is added.  The 
same webrev URL is used:
    http://cr.openjdk.java.net/~xuelei/8206925/webrev.05/

> Would the other test fail 
> (test/jdk/sun/security/ssl/X509KeyManager/CertificateAuthorities.java) 
> if that happens?
> 
No, it should pass.

Xuelei