[Pki-devel] [PATCH] 4 Replaced byte-to-char & char-to-byte converters.

[Matthew Harmsen]

On 12/16/11 17:24, Endi Sukma Dewata wrote:
> On 12/13/2011 4:25 PM, Adam Young wrote:
>> On 12/13/2011 02:03 PM, Andrew Wnuk wrote:
>>> Hopefully this patch was extremely well tested since it touches ASN.1
>>> encoding.
>> Do you have a specific set of tests that we should be running?
>
> I just posted patch #5 which contains some unit tests for the 
> converters. I've also updated and split patch #4 into #4-2a (renaming 
> the files) and #4-2b (replacing the implementation).
>
> Patch #5 should be applied before #4-2a/b to make sure there's no 
> regression.
>
> Mozilla JSS library also has some ASN.1 code, should we use them to 
> implement the converters?
>
> http://mxr.mozilla.org/mozilla/source/security/jss/org/mozilla/jss/asn1/
>
>
>
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Endi,

Andrew and I have been looking at these changes, and we have the 
following concerns:

(1) First of all, we looked up the bug where some of the sun.io.* 
classes were deprecated (which mentions java.nio.charset and sun.nio.cs):

  * http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4948149

(2) There appears to be considerable concern on performance degradation 
when using "Charset":

  * http://stackoverflow.com/questions/2098137/fast-alternative-to-java-nio-charset-charset-decode-encode
  * http://www.theserverside.com/discussions/thread.tss?thread_id=61270

(3) Additionally, there have been alterations in the CS code in the past 
to fix problems encountered with the sun.io.* classes:

  * pki/base/util/src/netscape/security/util/ByteToCharPrintable.java

Although we have not gotten to the unit tests, we suspect that these 
will be great to have regardless of the direction that is decided upon.  
However, due to our concerns regarding performance, could we have some 
tests added (unit or a test tool) which obtain performance results for 
the existing methods versus the proposed newer methods?

If no discernable performance issues are encountered, most of these 
changes appear to be acceptable -- the questionable one being the 
replacing of the code that addressed issue (3) above.

If there is an unacceptable degradation in performance, perhaps we could 
utilize some customized Java classes to perform these functions. As an 
alternative approach, as Endi alluded to, there is some ASN.1 code in 
Mozilla JSS, and speaking with Bob Relyea, we have been postulating on 
how much work would be involved to write JNI bindings via JSS to the 
ASN.1 encoders/decoders contained in NSS instead of moving this code to 
use java.nio.* classes.  Theoretically, we may limit our performance 
issues in exchange for the extra work involved in making the effort to 
standardize on the NSS ASN.1 engine (although I don't know if this will 
resolve issues such as (3) noted above).

-- Matt
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