Code Review Request for 7146728 and 7130959

Brad Wetmore bradford.wetmore at
Fri Mar 2 17:31:51 PST 2012
Mainly just a request for some additional commenting so the reader 
doesn't have to have a good understanding of the BigInteger logic to 
understand the assumptions being made here:

     For example, if the expected bits of the modulus is
     1024 bits (128 bytes exactly)

     secret-magnitude     secret.length           action
     ================     =============           ======
     1024                 1025 bits (129 bytes)   trim front byte
     1023                 1024 bits (128 bytes)   return
                                                  (sign bit (always 0)
                                                   becomes leading 0)
     1015                 1016 bits (127 bytes)   shift to end of array
                                                  (implied leading 0's)

In the second bit of code, you have the new ProviderException that you 
don't have in the first.  I'm not sure how you could get into this case, 
if you're % by modulus, but I guess it's good to be careful.  That said, 
you should either make consistent with the above or remove.  You might 
also combine the actual copy logic into a single function called from both.

     // Solaris

Shouldn't this be "// Solaris/NSS", for the case in which there isn't a 
leading zero?

For performance, it's a shame that engineGenerateSecret(byte[] 
sharedSecret, int offset) is doing a second copy here.  Not a request to 
do anything, just an observation.
 >    Security.addProvider(jce)

Good grief!  ;)  Still finding these!

I think you should include the new bugid.

      @bug 7146728
New bugid

     @bug 4942494 7146728

Indention problem around the try.

Was the change at 69 because the leading zeros were being trimmed?


On 3/1/2012 2:03 PM, Valerie (Yu-Ching) Peng wrote:
> Yes, that's the section that mentioned the generated secret having the
> same length as p.
> I guess it depends on how it's interpreted. The way I look at it is that
> if the generated secrets aren't of the same length, then whoever using
> this variant for deriving the keying material will need to do the extra
> work of checking the size of generated secret assuming that they know
> the size of p to add back the leading 0s if needed.
> I can't find any specification dictating trimming off the leading 0s for
> the generated secret. Considering both models, preserving vs trimming, I
> feel the former makes more sense since it is simpler to use and provides
> more flexibility than the later. RFC 2631 has not be crystal clear on
> this I am afraid, that's why there has been some inconsistency in
> different vendors implementation since people interpret what they read
> differently.
> Valerie
> On 02/29/12 23:00, Brad Wetmore wrote:
>> On 2/21/2012 5:33 PM, Valerie (Yu-Ching) Peng wrote:
>>> Brad,
>>> Can you please review the fixes for the following 2 bugs:
>>> * 7146728: Inconsistent length for the generated secret using DH key
>>> agreement impl from SunJCE and PKCS11
>>> o
>>> This impacts both SunJCE provider and SunPKCS11 provider. The
>>> implementations are inconsistent within SunJCE provider itself
>>> between the engineGenerateSecret() and
>>> engineGenerateSecret(byte[], int). Given that RFC 2631 specifies
>>> the leading 0s must be preserved so the generated secret has as
>>> many octets as the prime P,
>> Just to be clear here, you're referring to Section 2.1.2 of 2631,
>> which is just one of the DH Key agreement variants (based on X9.42)
>> for generating Keying Material from secret keys obtained from a "raw"
>> DH calculations, and is then subject later SHA1 manipulations, right?
>> This method provides motivation/incentive to output our secret keys
>> with the same lengths, but I don't think this RFC makes any claims
>> that the general output of "raw" DH key agreement operation must be
>> the same length.
>> I'll take another look over the code tomorrow.
>> Thanks,
>> Brad
>> I have changed both SunJCE and
>>> SunPKCS11 provider to do so. When testing against Solaris and
>>> NSS libraries, Solaris preserves the leading 0s while NSS trims
>>> it off, thus similar handling is also needed in SunPKCS11 provider.
>>> * 7130959: Tweak 7058133 fix for JDK 8 (javah makefile changes)
>>> o
>>> Instead of using the -Xbootclasspath, switching over to use
>>> -boothclasspath for consistency with the backported changes in
>>> the update releases for earlier JDK, e.g. 7u.
>>> Thanks,
>>> Valerie

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