Initializing Secure Random (Reprise)

[Peter Levart]

Hi Roger,

I see the 8060435 bug already talks about that possible solution too.

I agree with Paul that a public static method on SecureRandom would be 
better for JDK9. Or maybe even some new class in java.util, which would 
implement just the interface to native /dev/urandom on Unixes and MSCAPI 
on Windows (without any SHA1 mixing or such) and make java security 
SeedGenerator depend on that rather than the other way around (where 
TLR/SplittableRandom depend on java security). I think this is better 
from modularization standpoint too.

In case of a new java.util class (what about a method on 
java.lang.System?) the code (together with native part on Windows) could 
just be copied from (Native)SeedGenerator where it is already tried and 
tested. Then NativeSeedGenerator would just become a facade for invoking 
java.util/java.lang.System method.

Regards, Peter

On 11/26/2014 12:15 AM, Peter Levart wrote:
>
> On 11/24/2014 09:46 PM, roger riggs wrote:
>> Hi,
>>
>> This topic has languished for a bit and could use a bit of expertise 
>> from
>> Windows developers.
>>
>> The improvements in entropy for initializing Secure Random in JDK 8 have
>> some negative attributes that affect maintainability, robustness and 
>> performance[1].
>> The dependency on networking, can in some OS's and configurations lead
>> to increased startup times and issues with bootstrapping the Java 
>> runtime.
>>
>> Martin has proposed[2] an alternative for Linux based on /dev/urandom
>> with a fallback to a simpler algorithm if /dev/urandom is not available.
>>
>> Since /dev/urandom is not native to Windows, it seems prudent to 
>> identify
>> a corresponding source of entropy data.
>>
>> What are the recommended ways on Windows to get seeds for random?
>> Please suggest one or more ways to initialize SecureRandom
>
> Hi Roger,
>
> Do you mean SecureRandom or ThreadLocalRandom/SplittbleRandom, since 
> the 8060435 talks about the later two ?
>
> As Bernd identified, the Windows equivalent to /dev/urandom is MSCAPI.
>
> 5 months ago I made an attempt to expose a part of contained internal 
> java security API to get access to /dev/urandom based and MSCAPI based 
> seed generators. Here's the thread with the discussion:
>
> http://mail.openjdk.java.net/pipermail/core-libs-dev/2014-June/027256.html
>
> The minimal patch was the following:
>
> http://cr.openjdk.java.net/~plevart/jdk9-dev/TLR_SR_SeedGenerator/webrev.01/
>
> Regards, Peter
>
>>
>> Thanks, Roger
>>
>> p.s. Sorry to be covering old ground but I don't have all the context.
>>
>>
>> [1] 8060435  SecureRandom initialization latency on Windows
>> https://bugs.openjdk.java.net/browse/JDK-8060435
>>
>> [2] 
>> http://cr.openjdk.java.net/~martin/webrevs/openjdk9/ThreadLocalRandom-system-entropy/
>