my $chpw = Crypt::Perl::PKCS10::Attribute::challengePassword->new($passwd);
This attribute stores a phrase UNENCRYPTED in the CSR. Don’t put anything in here that you consider sensitive!
It’s likely that you don’t need this attribute. Check with your Certificate Authority to find out for sure sure if you need to include this in your CSR.
Instances of this class represent a
challengePassword attribute of a PKCS #10 Certificate Signing Request (CSR).
You probably don’t need to instantiate this class directly; instead, you can instantiate it implicitly by listing out arguments to Crypt::Perl::PKCS10’s constructor. See that module’s SYNOPSIS for an example.