Code review request, 8028518, Increase the priorities of GCM cipher suites

Xuelei Fan Xuelei.Fan at Oracle.COM
Fri Jan 3 18:58:43 PST 2014


On 1/4/2014 10:47 AM, Bradford Wetmore wrote:
>
>
> On 1/3/2014 6:19 PM, Xuelei Fan wrote:
>> On 1/4/2014 6:41 AM, Bradford Wetmore wrote:
>>> Looks ok to me, with the exception as you pointed out that this doesn't
>>> follow section 4 of RFC 6460.
>> Sorry, I did not get it.  Would you mind point out the line number of
>> the concern?
>
> This section in RFC 6460:
>
>     A Suite B TLS client configured at a minimum level of security of 128
>     bits MUST offer the TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 or the
>     TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 cipher suite in the
>     ClientHello message.  The TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
>     cipher suite is preferred; if offered, it MUST appear before the
>     TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 cipher suite.
>
Understand.  Do you note the circumstance of this spec, at the "level of 
security of 128 bits"?  In the next paragraph, it also talks about " 
level of security of 192 bits".

    If configured at a minimum level of security of 192 bits, the client
    MUST offer the TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 cipher suite
    and MUST NOT offer the TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 cipher
    suite.

That's also one point I said that the preference are not RFC 6460 
compliant at present.  We may make improvement in the future.

> You have:
>
> 993  add("TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
> ...
> 995  add("TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
>
>>>  Why was this done, and how did you
>>> originally determine the original ciphersuite ordering for GCMs?
>>>
>> Per RFC 6460, there are two profiles, "Suite B Combination 1" and "Suite
>> B Combination 2".  SunJSSE default cipher suite preference does not
>> compliant to the profiles at present.  That's why it is said,
>> "The preference order of the GCM cipher suites does not follow the spec
>> of RFC 6460."
>>
>> About the ordering, please refer to line 964-977 of CipherSuite.java
>
> My question was, how did you choose the current order (currently lines
> 1080-1110:
>
> TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
> TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
I think except the above two cipher suites, the order of the following 
cipher suites still adhere to the rules described in line 964-977.  Right?

Thanks,
Xuelei

> TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
> TLS_RSA_WITH_AES_256_GCM_SHA384
> TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
> TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
> TLS_DHE_RSA_WITH_AES_256_GCM_SHA384
> TLS_DHE_DSS_WITH_AES_256_GCM_SHA384
> TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
> TLS_RSA_WITH_AES_128_GCM_SHA256
> TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256
> TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256
> TLS_DHE_RSA_WITH_AES_128_GCM_SHA256
> TLS_DHE_DSS_WITH_AES_128_GCM_SHA256
>
> Brad
>
>
>> Thanks,
>> Xuelei
>>
>>> Brad
>>>
>>>
>>> On 12/29/2013 7:56 PM, Xuelei Fan wrote:
>>>> Hi,
>>>>
>>>> Please review this small update.
>>>>
>>>> webrev: http://cr.openjdk.java.net/~xuelei/8028518/webrev.00/
>>>>
>>>> In TLS protocols, cipher suite specifies the crypto algorithms used in
>>>> TLS connections.  The priorities of cipher suites define the preference
>>>> order that a cipher suite may be used in a TLS connection.
>>>>
>>>> When introducing the AEAD/GCM cipher suites in SunJSSE provider (JEP
>>>> 115)[1], for better compatibility and interoperability, we decided to
>>>> decrease the priority of cipher suites in GCM mode for a while before
>>>> GCM technologies mature in the industry.
>>>>
>>>> It's time to consider to increase the priorities of GCM mode cipher
>>>> suite in early stage of JDK 9.
>>>>
>>>> Thanks,
>>>> Xuelei
>>>>
>>>> [1] http://openjdk.java.net/jeps/115
>>



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