That was my first thought as well, but Crypt::RSA stores the file in its own format that OpenSSL does not handle. If I can get it into a format that OpenSSL can convert, then I am all set. For example, the public key file format looks like this: $VAR1 = bless( { 'e' => 12345, 'n' => '70417859230752389054237849012374890235682758947589662343757682936589068473829473285793281610859206247239036189012957380568307162358317503', 'Version' => '1.0', 'Identity' => 'myname <myname@example.com>' }, 'Crypt::RSA::Key::Public' );