From f9871e32622786e24bd5ad32f6849e6e6235b323 Mon Sep 17 00:00:00 2001
From: David Bremner <bremner@unb.ca>
Date: Thu, 28 Apr 2011 08:50:52 -0300
Subject: [PATCH] Add GnuPGKey_to_OpenSSH_fpr

This copies sshfpr from monkeysphere, and pastes it into the skeleton of
OpenPGKey_to_OpenSSH_pub. Monkeyprogramming at its finest.
---
 Crypt/Monkeysphere/Keytrans.pm     | 37 ++++++++++++++++++++-
 unit-tests/40.keytrans/20.sshfpr.t | 52 ++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 unit-tests/40.keytrans/20.sshfpr.t

diff --git a/Crypt/Monkeysphere/Keytrans.pm b/Crypt/Monkeysphere/Keytrans.pm
index 1754a76..16542c1 100644
--- a/Crypt/Monkeysphere/Keytrans.pm
+++ b/Crypt/Monkeysphere/Keytrans.pm
@@ -7,7 +7,7 @@ use Carp;
 use MIME::Base64;
 
 use Exporter qw(import);
-our @EXPORT_OK=qw(GnuPGKey_to_OpenSSH_pub);
+our @EXPORT_OK=qw(GnuPGKey_to_OpenSSH_pub GnuPGKey_to_OpenSSH_fpr);
 
 
 # takes a Math::BigInt and returns it properly packed for openssh output.
@@ -47,6 +47,41 @@ sub openssh_rsa_pubkey_pack {
 	openssh_mpi_pack($modulus);
 }
 
+# calculate/print the fingerprint of an openssh-style keyblob:
+
+sub sshfpr {
+  my $keyblob = shift;
+  use Digest::MD5;
+  return join(':', map({unpack("H*", $_)} split(//, Digest::MD5::md5($keyblob))));
+}
+
+=pod
+
+=head2 GnuPGKey_to_OpenSSH_fpr
+
+Find the openssh compatible fingerprint of an (RSA) GnuPG::Key
+
+B<Note> you will need to add add bits and (RSA) to the string to
+exactly match the output of ssh-keygen -l.
+
+=head3 Arguments
+
+key - GnuPG::Key object
+
+=cut
+
+sub GnuPGKey_to_OpenSSH_fpr {
+  my $key = shift;
+
+  croak("not a GnuPG::Key!")
+    unless($key->isa('GnuPG::Key'));
+
+  croak("Not an RSA key!")
+    unless $key->algo_num == 1;
+
+  return sshfpr(openssh_rsa_pubkey_pack(@{$key->pubkey_data}), '');
+}
+
 =pod
 
 =head2 GnuPGKey_to_OpenSSH_pub
diff --git a/unit-tests/40.keytrans/20.sshfpr.t b/unit-tests/40.keytrans/20.sshfpr.t
new file mode 100644
index 0000000..d00a4b6
--- /dev/null
+++ b/unit-tests/40.keytrans/20.sshfpr.t
@@ -0,0 +1,52 @@
+# -*- perl -*-
+use Test::More;
+
+use Crypt::Monkeysphere::Keytrans qw(GnuPGKey_to_OpenSSH_fpr);
+use GnuPG::Interface;
+use File::Temp qw(tempdir);
+
+plan tests => 1;
+
+my $tempdir = tempdir("unitXXXXX", CLEANUP => 1);
+my $gnupg = new GnuPG::Interface();
+$gnupg->options->hash_init(homedir=>$tempdir);
+
+my $openpgpdata = "
+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: GnuPG v1.4.11 (GNU/Linux)
+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+=MxOB
+-----END PGP PUBLIC KEY BLOCK-----
+";
+
+
+my $sshdata = "e6:b3:db:be:c6:5d:f7:65:f2:bb:6e:06:69:36:f5:e5";
+
+
+my $input = IO::Handle->new();
+my $output = IO::Handle->new();
+my $handles = GnuPG::Handles->new(stdin => $input,
+                                  stdout => $output,
+                                  stderr => $output);
+
+my $pid = $gnupg->import_keys(handles => $handles);
+
+$input->write($openpgpdata);
+$input->close();
+waitpid($pid, 0);
+
+my @keys = $gnupg->get_public_keys();
+
+foreach $key (@keys) {
+  my $output = GnuPGKey_to_OpenSSH_fpr($key);
+  is($sshdata, $output);
+}
-- 
2.26.2