willjones has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to decrypt an Open PGP message string that was created with the haneWIN Javascript Open PGP encrypter. (http://www.hanewin.net/encrypt)

I have a file at "$BASEDIR/private.pgp" with my private key and a file at "$BASEDIR/public.pgp" with my public key. (I am running this in a CGI page.)

Here's the code I'm trying... 
use Crypt::OpenPGP;
use Crypt::OpenPGP::KeyRing;

my $PGPEncryptedMessage = "-----BEGIN PGP MESSAGE-----Version: haneWIN
+ JavascriptPG v2.0hIwDAAAAAAAAAAABA/4oJfsBR88yts6eY22RJDwEFyhxi2KWIJx
+6BR8fufIDN4j3H79sCTN3UHDYoCV5zluSyhdSmM8beF1+hQ7PvSsonDOXrGfovIb9/cIt
+QQg1CrgI63Xje85qWW3IUpebnt4UlPnXx1sxK46GtJIEckYppWbXubCunAdFhhCyiq4ZB
+qQnZ9EAojfFrI8zkVIC/gq7cMZsu1wgn7/lcUvFewUNWWrU8ykAiC5t=R2eG-----END 
+PGP MESSAGE-----";

my $arg;
my $secring = Crypt::OpenPGP::KeyRing->new(Filename => "$BASEDIR/priva
+te.pgp") or die "Error: ".Crypt::OpenPGP::KeyRing->errstr;
my $pubring = Crypt::OpenPGP::KeyRing->new(Filename => "$BASEDIR/publi
+c.pgp") or die "Error: ".Crypt::OpenPGP::KeyRing->errstr;
$arg{SecRing}    = $secring;
$arg{PubRing}    = $pubring;

my $pgp = Crypt::OpenPGP->new(%arg);
my $message = $pgp->decrypt(Data => $PGPEncryptedMessage) or die "Erro
+r: ".$pgp->errstr;

print $cgi->header();
print "The secret message is: ".$message;

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When I run this it errors out on the $pgp->decrypt call and I get the following error message back...
"Error: Reading data packets failed: Unrecognizable armour"

Any ideas what I am doing wrong here?

Thanks

Replies are listed 'Best First'.
Re: Decrypting a message with Crypt::OpenPGP
by mscharrer (Hermit) on Apr 23, 2008 at 21:25 UTC
    The enc. message lacks the needed newlines. There must be a line break after the ---BEGIN ... --- line and two after the version line. Then one every 65 characters until the --- END .. --- line which has to start with one.

    Change the my $PGPEncryptedMessage line to: 

    my $PGPEncryptedMessage = <<'EOM';
-----BEGIN PGP MESSAGE-----
Version: haneWIN JavascriptPG v2.0

hIwDAAAAAAAAAAABA/4oJfsBR88yts6eY22RJDwEFyhxi2KWIJx6BR8fufIDN4j3
H79sCTN3UHDYoCV5zluSyhdSmM8beF1+hQ7PvSsonDOXrGfovIb9/cItQQg1CrgI
63Xje85qWW3IUpebnt4UlPnXx1sxK46GtJIEckYppWbXubCunAdFhhCyiq4ZBqQn
Z9EAojfFrI8zkVIC/gq7cMZsu1wgn7/lcUvFewUNWWrU8ykAiC5t=R2eG
-----END PGP MESSAGE-----
EOM

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    It's also better to use single quotes for such texts to avoid accidental expansion. Ok, ` $ @ & might not be valid anyway in PGP messages.

    PS: my $arg; should be my %arg;. Just add 

    use strict;
use warnings;

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    at the very start of you script.
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[d/l]
[select]
      Great Thanks. I put in the changes you indicated and now I am getting a different error.
      It says... "Error: Can't find a secret key to decrypt message"
      The private.pgp and public.pgp files are binary and have something like G4... in them
      I think it is finding these files okay because if I change the $secring assignment line to look for private1.pgp which doesn't exist it fails saying it can't find that file on that line.
      Am I missing something?
      Any ideas about what is wrong now?

      Thanks
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        I don't have experience with this particular module only with PGP/GPG in general, so I saw this error. I know however that there are different binary formats for RSA/DSA keys, and PGP/GPG keys are such. E.g. I had to convert an binary RSA key generated under Windows once to a different format to use it under Linux.

        Just try to import the binary key with GPG or the PGP freeware and then to export it again in ASCII format.

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