Comparing with the call:
MessageDigest md = MessageDigest.getInstance("SHA-1");
What's the benefit of the following call?
MessageDigest md = StandardMessageDigests.newSHA1();
What's the context that this new class is supposed to use?
Thanks & Regards,
Xuelei
On 5/5/2014 7:51 PM, Florian Weimer wrote:
> On 03/24/2014 05:30 PM, Florian Weimer wrote:
>> This CR adds a new class java.security.StandardMessageDigests:
>>
>> <http://fweimer.fedorapeople.org/openjdk/standard-message-digests/>
>>
>> Could I get a bug number if this change is fine in principle?
>>
>> Cryptographic hash functions are frequently used directly, often for
>> non-cryptographic purposes, so I think it makes sense to provide a
>> convenient way to access implementations for the most common hashes. The
>> new class follows the java.nio.charset.StandardCharsets precedent
>> (separate class, "Standard" in the name).
>>
>> I deliberately did not include support for MD5. It would be nice if we
>> could drop the NoSuchAlgorithmException, but this would be problematic
>> once there are providers that do not support SHA-1.
>>
>> Instantiating digest objects through cloning should be quite a bit
>> faster than the provider route (but I measured this some time ago only,
>> so these results could be outdated by now).
>
> Ping? This change proposal is in response to an earlier discussion:
>
> <http://mail.openjdk.java.net/pipermail/security-dev/2010-December/002531.html>
>
>
> I fixed the webrev so that the fast path actually runs, and now JMH
> reports a speedup:
>
> Benchmark Mode Samples Mean
> Mean error Units
> o.o.j.b.StandardMessageDigestsBenchmark.get thrpt 200
> 1650.350 53.388 ops/ms
> o.o.j.b.StandardMessageDigestsBenchmark.smd thrpt 200
> 1814.137 59.414 ops/ms
>
