#!/usr/bin/perl -w
use Crypt::OpenPGP;
use Crypt::OpenPGP::KeyRing;

my($keyfile, $email) = @ARGV;
my $ring = Crypt::OpenPGP::KeyRing->new(Filename => $keyfile);
my $pgp = Crypt::OpenPGP->new(PubRing => $ring);
my $kb = $ring->find_keyblock_by_uid($email);
my $alg = $kb->preferred_sk_alg;
my $crypt = $pgp->encrypt(
    Data => 'squeamish ossifrage',
    Recipients => [ $email ],
    Armour => 1,
    ($alg ? (Cipher => $alg) : ()), # use default if no preference loc
+ated
);
print $crypt;
exit 0;

{
    package Crypt::OpenPGP::KeyBlock;
    sub preferred_sk_alg {
        my $self = shift;
        use Crypt::OpenPGP::Cipher;
        my $supported = Crypt::OpenPGP::Cipher->supported;
        my @prefs;
        for my $sig (@{ $self->get('Crypt::OpenPGP::Signature') }) {
            if ($sig->is_primary) {
                unshift @prefs, @{ $sig->preferred_sk_alg };
            } else {
                push @prefs, @{ $sig->preferred_sk_alg };
            }
        }
        for (@prefs) {
            return $_ if $supported->{$_};
        }
        return;
    }
}
{
    package Crypt::OpenPGP::Signature;
    sub is_primary {
        my $self = shift;
        my $packet = $self->find_subpacket(25); # primary user id
        ($packet && $packet->{data}) || 0;
    }
    sub preferred_sk_alg {
        my $self = shift;
        my $packet = $self->find_subpacket(11); # preferred SK algorit
+hms
        $packet ? $packet->{data} : [];
    }
}

[download]

In reply to Crypt::OpenPGP - finding and using preferred SK algorithm by hv

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.