Crypt::GPG - An Object Oriented Interface to GnuPG.


 $Revision: 1.42 $
 $Date: 2002/12/11 03:33:19 $


  use Crypt::GPG;
  my $gpg = new Crypt::GPG;

  $gpg->gpgbin('/usr/bin/gpg');      # The GnuPG executable.
  $gpg->secretkey('0x2B59D29E');     # Set ID of default secret key.
  $gpg->passphrase('just testing');  # Set passphrase.

  # Sign a message:

  my $sign = $gpg->sign('testing again');

  # Encrypt a message:

  my @encrypted = $gpg->encrypt ('top secret', '');

  # Get message info:

  my @recipients = $gpg->msginfo($encrypted);

  # Decrypt / verify signature on a message, 

  my ($plaintext, $signature) = $gpg->verify($encrypted);

  # Key generation:

  $status = $gpg->keygen 
    ('Test', '', 'ELG-E', 2048, 0, 'test passphrase');
  print while (<$status>); close $status;

  # Key database manipulation:

  $gpg->addkey($key, @ids);
  @keys = $gpg->keydb(@ids);

  # Key manipulation:

  $key = $keys[0];
  $gpg->keypass($key, $oldpassphrase, $newpassphrase);
  $keystring = $gpg->export($key);


The Crypt::GPG module provides near complete access to GnuPG functionality through an object oriented interface. It provides methods for encryption, decryption, signing, signature verification, key generation, key export and import, and most other key management functions.

This module works almost identically to its cousin, Crypt::PGP5. The two modules together provide a uniform interface to deal with both PGP and GnuPG. Eventually, these modules will be folded into a single module which will interface with GnuPG as well as all versions of PGP.



Creates and returns a new Crypt::GPG object.



Sets the GPGBIN instance variable which gives the path to the GnuPG binary.


Sets the GPGOPTS instance variable which may be used to pass additional options to the GnuPG binary. For proper functioning of this module, it is advisable to always include '--lock-multiple' in the GPGOPTS string.


Sets the DELAY instance variable. This is the time (in seconds, or fractions of seconds) to wait after receiving a prompt from the GnuPG executable before starting to respond to it. I've noticed on some machines that the executable hangs if it gets input too fast. The delay is off by default.


Sets the SECRETKEY instance variable which may be a KeyID or a username. This is the ID of the default key to use for signing.


Sets the PASSPHRASE instance variable, required for signing and decryption.


Sets the TEXT instance variable. If set true, GnuPG will use network-compatible line endings for proper cross-platform compatibility and the plaintext will gain a newline at the end, if it does not already have one.


Sets the ARMOR instance variable, controlling the ASCII armoring of output. The default is to use ascii-armoring. The module has not been tested with this option turned off, and most likely will not work if you switch this off.


Sets the DETACH instance variable. If set true, the sign method will produce detached signature certificates, else it won't. The default is to produce detached signatures.


Sets the ENCRYPTSAFE instance variable. If set true, encryption will fail if trying to encrypt to a key which is not trusted. This is the default. Turn this off if you want to encrypt to untrusted keys.


Sets the VERSION instance variable which can be used to change the Version: string on the GnuPG output to whatever you like.


Sets the COMMENT instance variable which can be used to change the Comment: string on the GnuPG output to whatever you like.


Sets the DEBUG instance variable which causes the raw output of Crypt::GPG's interaction with the GnuPG binary to be dumped to STDOUT. By default, debugging is off.



Signs @message with the secret key specified with secretkey() and returns the result as a string.

decrypt(\@message, [\@signature])

This is just an alias for verify()

verify(\@message, [\@signature])

Decrypts and/or verifies the message in @message, optionally using the detached signature in @signature, and returns a list whose first element is plaintext message as a string. If the message was signed, a Crypt::GPG::Signature object is returned as the second element of the list.

The Crypt::GPG::Signature object can be queried with the following methods:

   $sig->validity();    # 'Good', 'BAD', or 'Unknown'
   $sig->keyid();       # ID of signing key
   $sig->time();        # Time the signature was made
   $sig->trusted();     # True or false depending on whether 
                          the signing key is trusted

Returns a list of the recipient key IDs that @ciphertext is encrypted to.

encrypt($plaintext, $keylist, [-sign] )

Encrypts $plaintext with the public keys of the recipients listed in $keylist and returns the result in a string, or undef if there was an error while processing. Returns undef if any of the keys are not found.

Either $plaintext or $keylist may be specified as either an arrayref or a simple scalar.

If $plaintext is a an arrayref, it will be join()ed without newlines.

If you want to encrypt to multiple recipients, you must use the arrayref version of $keylist. A scalar $keylist works for only a single key ID.

If the -sign option is provided, the message will be signed before encryption. The secret key and passphrase must be set for signing to work. They can be set with the secretkey() and passphrase() methods.

addkey($key, $pretend, @keyids)

Adds the keys given in $key to the user's key ring and returns a list of Crypt::GPG::Key objects corresponding to the keys that were added. $key may be a string or an array reference.

If $pretend is true, it pretends to add the key and creates the key object, but doesn't actually perform the key addition.

Optionally, a list of key IDs may be specified. If a list of key IDs is specified, only keys that match those IDs will be imported. The rest will be ignored.


Exports the key specified by the Crypt::GPG::Key object $key and returns the result as a string.

keygen($name, $email, $keytype, $keysize, $expire, $passphrase)

Creates a new keypair with the parameters specified. The only supported $keytype currently is 'ELG-E'. $keysize can be any of 768, 1024, 2048, 3072 or 4096. Returns undef if there was an error, otherwise returns a filehandle that reports the progress of the key generation process similar to the way GnuPG does. The key generation is not complete till you read an EOF from the returned filehandle.

certify($keyid, $local, @uids)

Certifies to the authenticity of UIDs of the key with ID $keyid. If $local is true, the certification will be non-exportable. The @uids parameter should contain the list of UIDs to certify (the first UID of a key is 0).


Returns an array of Crypt::GPG::Key objects corresponding to the Key IDs listed in @keyids. This method used to be called keyinfo and that is still an alias to this method.


Parses a raw GnuPG formatted key listing in @keylist and returns an array of Crypt::GPG::Key objects.

keypass($key, $oldpass, $newpass)

Change the passphrase for a key. Returns true if the passphrase change succeeded, false if not, or undef if there was an error.


Deletes the key specified by the Crypt::GPG::Key object $key from the user's key ring. Returns undef if there was an error, or 1 if the key was successfully deleted.


Disables the key specified by the Crypt::GPG::Key object $key.


Enables the key specified by the Crypt::GPG::Key object $key.


      Documentation coming soon.


      Documentation coming soon.


  • Error checking needs work.

  • Some key manipulation functions are missing.

  • The method call interface is subject to change in future versions. Key manipulation methods will be encapsulated into the Crypt::GPG::Key class.

  • The current implementation will probably eat up all your RAM if you try to operate on huge messages. In future versions, this will be addressed by reading from and returning filehandles, rather than using in-core data.

  • Methods may break if you don't use ASCII armoring.


    $Log:,v $ Revision 1.42 2002/12/11 03:33:19 cvs

     - Fixed bug in certify() when trying to certify revoked a key.
     - Applied dharris\'s patch to allow for varying date formats
       between gpg versions, and fix time parsing and the
       Crypt::GPG::Signature autoloaded accessor functions.

    Revision 1.40 2002/09/23 23:01:53 cvs

     - Fixed a bug in keypass()
     - Documentation fixes.

    Revision 1.37 2002/09/21 02:37:49 cvs

     - Fixed signing option in encrypt.

    Revision 1.36 2002/09/21 00:03:29 cvs

     - Added many tests and fixed a bunch of bugs.

    Revision 1.34 2002/09/20 19:07:11 cvs

     - Extensively modified formatting to make the code easier to
       read. All lines are now < 80 chars.
     - Removed all instances of invoking a shell.
     - Misc. other stuff.

    Revision 1.31 2002/09/20 16:38:45 cvs

     - Cleaned up export and addkey. Fixed(?) addkey clobbering trustdb
       problem (thanks to jrray\ for the patch). Added
       support for signature verification on addkey pretend.
     - No calls to POSIX::tmpnam remain (thanks to radek\ and
       jrray\ for suggesting File::Temp).

    Revision 1.30 2002/09/20 15:25:47 cvs

     - Fixed up tempfile handling and eliminated calls to the shell in
       encrypt(), sign() and msginfo(). Passing all currently defined
     - Hopefully also fixed signing during encryption and verification of
       detached signatures. Not tested this yet.

    Revision 1.29 2002/09/20 11:19:02 cvs

     - Removed hack to Version: string. Only the Comment: string in GPG
       output is now modified by Crypt::GPG. (Thanks to
       eisen\ for pointing out the bug here)
     - Removed code that incorrectly replaced 'PGP MESSAGE' with 'PGP
       SIGNATURE' on detached signatures. (Thanks to ddcc\ for
       pointing this out).
     - Fixed up addkey() to properly handle pretend mode and to
       selectively import only requested key IDs from a key block.
     - parsekeys() now also figures out which keyring a key belongs to.
     - Added certify() method, to enable certifying keys.
     - Added Crypt::GPG::Signature methods - validity(), keyid(), time()
       and trusted().


Crypt::GPG is Copyright (c) 2000-2001 Ashish Gulhati <>. All Rights Reserved.


Thanks to Barkha for inspiration and lots of laughs, and to the GnuPG team.


This code is free software; you can redistribute it and/or modify it under the same terms as Perl itself.