[Mono-bugs] [Bug 55445][Wis] Changed - RSACryptoServiceProvider.ExportParameters method takes 35 seconds

bugzilla-daemon@bugzilla.ximian.com bugzilla-daemon@bugzilla.ximian.com
Wed, 10 Mar 2004 19:51:31 -0500 (EST)


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Changed by spouliot@videotron.ca.

http://bugzilla.ximian.com/show_bug.cgi?id=55445

--- shadow/55445	2004-03-10 18:52:40.000000000 -0500
+++ shadow/55445.tmp.25960	2004-03-10 19:51:31.000000000 -0500
@@ -1,14 +1,14 @@
 Bug#: 55445
 Product: Mono: Runtime
 Version: unspecified
 OS: SUSE 9.0
 OS Details: 
-Status: NEW   
-Resolution: 
-Severity: 
+Status: RESOLVED   
+Resolution: NOTABUG
+Severity: Unknown
 Priority: Wishlist
 Component: misc
 AssignedTo: mono-bugs@ximian.com                            
 ReportedBy: jluciani@novell.com               
 QAContact: mono-bugs@ximian.com
 TargetMilestone: ---
@@ -77,6 +77,59 @@
 All of the time.
 
 
 Additional Information:
 
 Running on a build of mono that is about a week old.
+
+------- Additional Comments From spouliot@videotron.ca  2004-03-10 19:51 -------
+BAD NEWS
+This seems (only) a bit long but, I'm sorry to report, normal :-(
+
+Mono use a totally managed implementation for RSA (and DSA, DH ...). 
+This has many advantages (http://pages.infinit.net/ctech/20040309-
+1036.html) but also some inconvenient – mostly performance. Creating 
+a new key pair is a very CPU heavy process so every processor cycle 
+counts. Using a high level language like C# on top of a JIT, even as 
+good as Mono, can hardly compare to hand-tuned assembly language 
+often found for doing the job (or at least "key" part of the job). 
+The result is that it can take much more time to generate similar 
+sized key pairs in managed code.
+
+
+"POTENTIAL" GOOD NEWS
+However it may not be "as bad" as it seems in the sample...
+
+Unlike MS implementation Mono doesn't generate a new key pair in its 
+constructor (when no CspParameter object is specified as a 
+parameter). This is because it's a common (and bad) pattern to 
+create a RSACryptoServiceProvider object then immediately import an 
+existing public key (or key pair) into it. Sadly I've seen this in 
+too many samples on the Internet and this simply kills performance 
+on the Windows platform (in particular for server applications).
+
+In order to avoid this pattern Mono doesn’t generate a new key pair 
+until it is actually required. This is nice most of the time but 
+this also means that, in the case a new key pair is really needed, 
+the delay required generating a new key pair moves until later in an 
+application process (when the UI may not expect this).
+
+But this also means that calling again a method requiring either the 
+public or private key will be much faster because it doesn’t require 
+generating (again) a new key pair (see sample). So this is "only" a 
+one time hit... Hopefully most implementation do not require 
+creating new key pairs very frequently as opposed to 
+signing/verifying or encrypting/decrypting.
+
+
+// wow this is really fast !
+RSACryptoServiceProvider rsa = new RSACryptoServiceProvider (16384);
+// hey what’s going on ??? ... for about 24 hours ...
+string keypair = rsa.ToXmlString (true);
+// we seems awake now!
+string backup = rsa.ToXmlString (true);
+
+
+Another good news is that most optimization made to the JIT will 
+results in improvement in the key generation performance. So it will 
+keep going faster without changing the code ;-)
+