To answer my own question, I just noticed that GnuPG::Tie.pm does what I want. There is example code here:

http://search.cpan.org/doc/FRAJULAC/GnuPG-0.07/GnuPG/Tie.pm

In reply to GnuPG::Tie.pm does this by markjugg
in thread Favorite PGP module for web-to-email forms? by markjugg

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