Brad,
Thanks for the review.
Please find the update webrev at:
http://cr.openjdk.java.net/~valeriep/7146728/webrev.01/
On 03/02/12 17:31, Brad Wetmore wrote:
DHKeyAGreement.java
===================
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)
...
I added more comments to both code blocks to explain what's going on.
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.
Good point, I modified the engineGenerateSecret() to leverage
engineGenerateSecret(byte[], int) method.
P11KeyAgreement.java
====================
// Solaris
Shouldn't this be "// Solaris/NSS", for the case in which there isn't
a leading zero?
Well, I think putting NSS in both places seems somewhat confusing. What
I tried to point out is that NSS (at least in the older versions, I have
not tried the newer version to see if they switched behavior) trims off
the leading 0s whenever possible. I've made some modification hoping to
make it clearer.
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.
Well, that's just how it is written from the very beginning. The current
impl is more optimized for engineGenerateSecret().
Probably not worthwhile to re-write the code to get rid of the extra
copying.
DHKeyAgreement2.java
====================
> Security.addProvider(jce)
Good grief! ;) Still finding these!
I think you should include the new bugid.
@bug 7146728
Done.
TestShort.java
==============
New bugid
@bug 4942494 7146728
Done.
Indention problem around the try.
Fixed.
Was the change at 69 because the leading zeros were being trimmed?
Yes, SunPKCS11 provider was explicitly trimming off the leading 0s
before this 7146728 fix.
Now that we decide to preserve the leading 0s, this test vector has to
be updated.
Thanks,
Valerie
Brad
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 http://cr.openjdk.java.net/~valeriep/7146728/webrev.00/
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 http://cr.openjdk.java.net/~valeriep/7130959/webrev.00/
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
