It seems like the default packages locations are nto added in the ppm perl module manager. All you have to do it to launch it by "ppm" and under preference add these repositories :
http://www.bribes.org/perl/ppm, for the www.bribes.org Perl 5.10 repository
http://trouchelle.com/ppm10/, for the trouchelle Perl 5.10 repository
http://cpan.uwinnipeg.ca/PPMPackages/10xx/, for the uwinnipeg Perl 5.10 repository
And there you go. You can now download SSLeay and other modules for Perl 5.10.