Re: Help verifying RSA PSS signature in Perl with Crypt::RSA and Crypt::RSA::SS::PSS

Hello cryptques, and welcome to the Monastery!

I've tested those two modules and I *am* able to generate and verify a PSS signature in Perl...

Are you sure it’s working correctly? When I run your script with the line:

print ($verify ? 'verified' : 'failed'), "\n";
[download]

added at the end, I get an intermittent error:

13:17 >perl 592_SoPW.pl
verified
13:17 >perl 592_SoPW.pl
verified
13:17 >perl 592_SoPW.pl
verified
13:18 >perl 592_SoPW.pl
PARI:   ***   forbidden division t_INT % t_REAL. at C:/Perl/Strawberry
+/spp-spec-64int-5.16.0.1-beta3-32bit-portable/perl/vendor/lib/Crypt/R
+SA/Key/Private.pm line 127.

13:18 >
[download]

I’m running the latest version (1.99) of Crypt::RSA.

With a little detective work using eval and Carp, it appears the error is generated by the line:

$signature = $pss->sign ( Message => $message,
                          Key => $private ) || die $pss->errstr;
[download]

Maybe some other monk knows of a fix or workaround?

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

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Re^2: Help verifying RSA PSS signature in Perl with Crypt::RSA and Crypt::RSA::SS::PSS by cryptques (Novice) on Mar 31, 2013 at 09:19 UTC
Yikes, you're right, Athanasius! It fails intermittently! When I run the script several times consecutively it sometimes fails with the same PARI "forbidden division" error that you point out. I hadn't seen that before. Sounds like a bug in Math::Pari, which I had to build in order to build Crypt::RSA :-( Thanks for your help and for taking time to try it out. I'll have to figure out some other way of doing this...	[reply]

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Re^2: Help verifying RSA PSS signature in Perl with Crypt::RSA and Crypt::RSA::SS::PSS
by cryptques (Novice) on Mar 31, 2013 at 09:19 UTC

Yikes, you're right, Athanasius! It fails intermittently!

When I run the script several times consecutively it sometimes fails with the same PARI "forbidden division" error that you point out. I hadn't seen that before.

Sounds like a bug in Math::Pari, which I had to build in order to build Crypt::RSA :-(

Thanks for your help and for taking time to try it out. I'll have to figure out some other way of doing this...

[reply]