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+<?php
+
+/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
+
+/**
+ * Crypt_GPG is a package to use GPG from PHP
+ *
+ * This package provides an object oriented interface to GNU Privacy
+ * Guard (GPG). It requires the GPG executable to be on the system.
+ *
+ * Though GPG can support symmetric-key cryptography, this package is intended
+ * only to facilitate public-key cryptography.
+ *
+ * This file contains the main GPG class. The class in this file lets you
+ * encrypt, decrypt, sign and verify data; import and delete keys; and perform
+ * other useful GPG tasks.
+ *
+ * Example usage:
+ * <code>
+ * <?php
+ * // encrypt some data
+ * $gpg = new Crypt_GPG();
+ * $gpg->addEncryptKey($mySecretKeyId);
+ * $encryptedData = $gpg->encrypt($data);
+ * ?>
+ * </code>
+ *
+ * PHP version 5
+ *
+ * LICENSE:
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of the
+ * License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * @category  Encryption
+ * @package   Crypt_GPG
+ * @author    Nathan Fredrickson <nathan@silverorange.com>
+ * @author    Michael Gauthier <mike@silverorange.com>
+ * @copyright 2005-2010 silverorange
+ * @license   http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
+ * @version   CVS: $Id: GPG.php 302814 2010-08-26 15:43:07Z gauthierm $
+ * @link      http://pear.php.net/package/Crypt_GPG
+ * @link      http://pear.php.net/manual/en/package.encryption.crypt-gpg.php
+ * @link      http://www.gnupg.org/
+ */
+
+/**
+ * Signature handler class
+ */
+require_once 'Crypt/GPG/VerifyStatusHandler.php';
+
+/**
+ * Decryption handler class
+ */
+require_once 'Crypt/GPG/DecryptStatusHandler.php';
+
+/**
+ * GPG key class
+ */
+require_once 'Crypt/GPG/Key.php';
+
+/**
+ * GPG sub-key class
+ */
+require_once 'Crypt/GPG/SubKey.php';
+
+/**
+ * GPG user id class
+ */
+require_once 'Crypt/GPG/UserId.php';
+
+/**
+ * GPG process and I/O engine class
+ */
+require_once 'Crypt/GPG/Engine.php';
+
+/**
+ * GPG exception classes
+ */
+require_once 'Crypt/GPG/Exceptions.php';
+
+// {{{ class Crypt_GPG
+
+/**
+ * A class to use GPG from PHP
+ *
+ * This class provides an object oriented interface to GNU Privacy Guard (GPG).
+ *
+ * Though GPG can support symmetric-key cryptography, this class is intended
+ * only to facilitate public-key cryptography.
+ *
+ * @category  Encryption
+ * @package   Crypt_GPG
+ * @author    Nathan Fredrickson <nathan@silverorange.com>
+ * @author    Michael Gauthier <mike@silverorange.com>
+ * @copyright 2005-2010 silverorange
+ * @license   http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
+ * @link      http://pear.php.net/package/Crypt_GPG
+ * @link      http://www.gnupg.org/
+ */
+class Crypt_GPG
+{
+    // {{{ class error constants
+
+    /**
+     * Error code returned when there is no error.
+     */
+    const ERROR_NONE = 0;
+
+    /**
+     * Error code returned when an unknown or unhandled error occurs.
+     */
+    const ERROR_UNKNOWN = 1;
+
+    /**
+     * Error code returned when a bad passphrase is used.
+     */
+    const ERROR_BAD_PASSPHRASE = 2;
+
+    /**
+     * Error code returned when a required passphrase is missing.
+     */
+    const ERROR_MISSING_PASSPHRASE = 3;
+
+    /**
+     * Error code returned when a key that is already in the keyring is
+     * imported.
+     */
+    const ERROR_DUPLICATE_KEY = 4;
+
+    /**
+     * Error code returned the required data is missing for an operation.
+     *
+     * This could be missing key data, missing encrypted data or missing
+     * signature data.
+     */
+    const ERROR_NO_DATA = 5;
+
+    /**
+     * Error code returned when an unsigned key is used.
+     */
+    const ERROR_UNSIGNED_KEY = 6;
+
+    /**
+     * Error code returned when a key that is not self-signed is used.
+     */
+    const ERROR_NOT_SELF_SIGNED = 7;
+
+    /**
+     * Error code returned when a public or private key that is not in the
+     * keyring is used.
+     */
+    const ERROR_KEY_NOT_FOUND = 8;
+
+    /**
+     * Error code returned when an attempt to delete public key having a
+     * private key is made.
+     */
+    const ERROR_DELETE_PRIVATE_KEY = 9;
+
+    /**
+     * Error code returned when one or more bad signatures are detected.
+     */
+    const ERROR_BAD_SIGNATURE = 10;
+
+    /**
+     * Error code returned when there is a problem reading GnuPG data files.
+     */
+    const ERROR_FILE_PERMISSIONS = 11;
+
+    // }}}
+    // {{{ class constants for data signing modes
+
+    /**
+     * Signing mode for normal signing of data. The signed message will not
+     * be readable without special software.
+     *
+     * This is the default signing mode.
+     *
+     * @see Crypt_GPG::sign()
+     * @see Crypt_GPG::signFile()
+     */
+    const SIGN_MODE_NORMAL = 1;
+
+    /**
+     * Signing mode for clearsigning data. Clearsigned signatures are ASCII
+     * armored data and are readable without special software. If the signed
+     * message is unencrypted, the message will still be readable. The message
+     * text will be in the original encoding.
+     *
+     * @see Crypt_GPG::sign()
+     * @see Crypt_GPG::signFile()
+     */
+    const SIGN_MODE_CLEAR = 2;
+
+    /**
+     * Signing mode for creating a detached signature. When using detached
+     * signatures, only the signature data is returned. The original message
+     * text may be distributed separately from the signature data. This is
+     * useful for miltipart/signed email messages as per
+     * {@link http://www.ietf.org/rfc/rfc3156.txt RFC 3156}.
+     *
+     * @see Crypt_GPG::sign()
+     * @see Crypt_GPG::signFile()
+     */
+    const SIGN_MODE_DETACHED = 3;
+
+    // }}}
+    // {{{ class constants for fingerprint formats
+
+    /**
+     * No formatting is performed.
+     *
+     * Example: C3BC615AD9C766E5A85C1F2716D27458B1BBA1C4
+     *
+     * @see Crypt_GPG::getFingerprint()
+     */
+    const FORMAT_NONE = 1;
+
+    /**
+     * Fingerprint is formatted in the format used by the GnuPG gpg command's
+     * default output.
+     *
+     * Example: C3BC 615A D9C7 66E5 A85C  1F27 16D2 7458 B1BB A1C4
+     *
+     * @see Crypt_GPG::getFingerprint()
+     */
+    const FORMAT_CANONICAL = 2;
+
+    /**
+     * Fingerprint is formatted in the format used when displaying X.509
+     * certificates
+     *
+     * Example: C3:BC:61:5A:D9:C7:66:E5:A8:5C:1F:27:16:D2:74:58:B1:BB:A1:C4
+     *
+     * @see Crypt_GPG::getFingerprint()
+     */
+    const FORMAT_X509 = 3;
+
+    // }}}
+    // {{{ other class constants
+
+    /**
+     * URI at which package bugs may be reported.
+     */
+    const BUG_URI = 'http://pear.php.net/bugs/report.php?package=Crypt_GPG';
+
+    // }}}
+    // {{{ protected class properties
+
+    /**
+     * Engine used to control the GPG subprocess
+     *
+     * @var Crypt_GPG_Engine
+     *
+     * @see Crypt_GPG::setEngine()
+     */
+    protected $engine = null;
+
+    /**
+     * Keys used to encrypt
+     *
+     * The array is of the form:
+     * <code>
+     * array(
+     *   $key_id => array(
+     *     'fingerprint' => $fingerprint,
+     *     'passphrase'  => null
+     *   )
+     * );
+     * </code>
+     *
+     * @var array
+     * @see Crypt_GPG::addEncryptKey()
+     * @see Crypt_GPG::clearEncryptKeys()
+     */
+    protected $encryptKeys = array();
+
+    /**
+     * Keys used to decrypt
+     *
+     * The array is of the form:
+     * <code>
+     * array(
+     *   $key_id => array(
+     *     'fingerprint' => $fingerprint,
+     *     'passphrase'  => $passphrase
+     *   )
+     * );
+     * </code>
+     *
+     * @var array
+     * @see Crypt_GPG::addSignKey()
+     * @see Crypt_GPG::clearSignKeys()
+     */
+    protected $signKeys = array();
+
+    /**
+     * Keys used to sign
+     *
+     * The array is of the form:
+     * <code>
+     * array(
+     *   $key_id => array(
+     *     'fingerprint' => $fingerprint,
+     *     'passphrase'  => $passphrase
+     *   )
+     * );
+     * </code>
+     *
+     * @var array
+     * @see Crypt_GPG::addDecryptKey()
+     * @see Crypt_GPG::clearDecryptKeys()
+     */
+    protected $decryptKeys = array();
+
+    // }}}
+    // {{{ __construct()
+
+    /**
+     * Creates a new GPG object
+     *
+     * Available options are:
+     *
+     * - <kbd>string  homedir</kbd>        - the directory where the GPG
+     *                                       keyring files are stored. If not
+     *                                       specified, Crypt_GPG uses the
+     *                                       default of <kbd>~/.gnupg</kbd>.
+     * - <kbd>string  publicKeyring</kbd>  - the file path of the public
+     *                                       keyring. Use this if the public
+     *                                       keyring is not in the homedir, or
+     *                                       if the keyring is in a directory
+     *                                       not writable by the process
+     *                                       invoking GPG (like Apache). Then
+     *                                       you can specify the path to the
+     *                                       keyring with this option
+     *                                       (/foo/bar/pubring.gpg), and specify
+     *                                       a writable directory (like /tmp)
+     *                                       using the <i>homedir</i> option.
+     * - <kbd>string  privateKeyring</kbd> - the file path of the private
+     *                                       keyring. Use this if the private
+     *                                       keyring is not in the homedir, or
+     *                                       if the keyring is in a directory
+     *                                       not writable by the process
+     *                                       invoking GPG (like Apache). Then
+     *                                       you can specify the path to the
+     *                                       keyring with this option
+     *                                       (/foo/bar/secring.gpg), and specify
+     *                                       a writable directory (like /tmp)
+     *                                       using the <i>homedir</i> option.
+     * - <kbd>string  trustDb</kbd>        - the file path of the web-of-trust
+     *                                       database. Use this if the trust
+     *                                       database is not in the homedir, or
+     *                                       if the database is in a directory
+     *                                       not writable by the process
+     *                                       invoking GPG (like Apache). Then
+     *                                       you can specify the path to the
+     *                                       trust database with this option
+     *                                       (/foo/bar/trustdb.gpg), and specify
+     *                                       a writable directory (like /tmp)
+     *                                       using the <i>homedir</i> option.
+     * - <kbd>string  binary</kbd>         - the location of the GPG binary. If
+     *                                       not specified, the driver attempts
+     *                                       to auto-detect the GPG binary
+     *                                       location using a list of known
+     *                                       default locations for the current
+     *                                       operating system. The option
+     *                                       <kbd>gpgBinary</kbd> is a
+     *                                       deprecated alias for this option.
+     * - <kbd>boolean debug</kbd>          - whether or not to use debug mode.
+     *                                       When debug mode is on, all
+     *                                       communication to and from the GPG
+     *                                       subprocess is logged. This can be
+     *
+     * @param array $options optional. An array of options used to create the
+     *                       GPG object. All options are optional and are
+     *                       represented as key-value pairs.
+     *
+     * @throws Crypt_GPG_FileException if the <kbd>homedir</kbd> does not exist
+     *         and cannot be created. This can happen if <kbd>homedir</kbd> is
+     *         not specified, Crypt_GPG is run as the web user, and the web
+     *         user has no home directory. This exception is also thrown if any
+     *         of the options <kbd>publicKeyring</kbd>,
+     *         <kbd>privateKeyring</kbd> or <kbd>trustDb</kbd> options are
+     *         specified but the files do not exist or are are not readable.
+     *         This can happen if the user running the Crypt_GPG process (for
+     *         example, the Apache user) does not have permission to read the
+     *         files.
+     *
+     * @throws PEAR_Exception if the provided <kbd>binary</kbd> is invalid, or
+     *         if no <kbd>binary</kbd> is provided and no suitable binary could
+     *         be found.
+     */
+    public function __construct(array $options = array())
+    {
+        $this->setEngine(new Crypt_GPG_Engine($options));
+    }
+
+    // }}}
+    // {{{ importKey()
+
+    /**
+     * Imports a public or private key into the keyring
+     *
+     * Keys may be removed from the keyring using
+     * {@link Crypt_GPG::deletePublicKey()} or
+     * {@link Crypt_GPG::deletePrivateKey()}.
+     *
+     * @param string $data the key data to be imported.
+     *
+     * @return array an associative array containing the following elements:
+     *               - <kbd>fingerprint</kbd>       - the fingerprint of the
+     *                                                imported key,
+     *               - <kbd>public_imported</kbd>   - the number of public
+     *                                                keys imported,
+     *               - <kbd>public_unchanged</kbd>  - the number of unchanged
+     *                                                public keys,
+     *               - <kbd>private_imported</kbd>  - the number of private
+     *                                                keys imported,
+     *               - <kbd>private_unchanged</kbd> - the number of unchanged
+     *                                                private keys.
+     *
+     * @throws Crypt_GPG_NoDataException if the key data is missing or if the
+     *         data is is not valid key data.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function importKey($data)
+    {
+        return $this->_importKey($data, false);
+    }
+
+    // }}}
+    // {{{ importKeyFile()
+
+    /**
+     * Imports a public or private key file into the keyring
+     *
+     * Keys may be removed from the keyring using
+     * {@link Crypt_GPG::deletePublicKey()} or
+     * {@link Crypt_GPG::deletePrivateKey()}.
+     *
+     * @param string $filename the key file to be imported.
+     *
+     * @return array an associative array containing the following elements:
+     *               - <kbd>fingerprint</kbd>       - the fingerprint of the
+     *                                                imported key,
+     *               - <kbd>public_imported</kbd>   - the number of public
+     *                                                keys imported,
+     *               - <kbd>public_unchanged</kbd>  - the number of unchanged
+     *                                                public keys,
+     *               - <kbd>private_imported</kbd>  - the number of private
+     *                                                keys imported,
+     *               - <kbd>private_unchanged</kbd> - the number of unchanged
+     *                                                private keys.
+     *                                                  private keys.
+     *
+     * @throws Crypt_GPG_NoDataException if the key data is missing or if the
+     *         data is is not valid key data.
+     *
+     * @throws Crypt_GPG_FileException if the key file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function importKeyFile($filename)
+    {
+        return $this->_importKey($filename, true);
+    }
+
+    // }}}
+    // {{{ exportPublicKey()
+
+    /**
+     * Exports a public key from the keyring
+     *
+     * The exported key remains on the keyring. To delete the public key, use
+     * {@link Crypt_GPG::deletePublicKey()}.
+     *
+     * If more than one key fingerprint is available for the specified
+     * <kbd>$keyId</kbd> (for example, if you use a non-unique uid) only the
+     * first public key is exported.
+     *
+     * @param string  $keyId either the full uid of the public key, the email
+     *                       part of the uid of the public key or the key id of
+     *                       the public key. For example,
+     *                       "Test User (example) <test@example.com>",
+     *                       "test@example.com" or a hexadecimal string.
+     * @param boolean $armor optional. If true, ASCII armored data is returned;
+     *                       otherwise, binary data is returned. Defaults to
+     *                       true.
+     *
+     * @return string the public key data.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if a public key with the given
+     *         <kbd>$keyId</kbd> is not found.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function exportPublicKey($keyId, $armor = true)
+    {
+        $fingerprint = $this->getFingerprint($keyId);
+
+        if ($fingerprint === null) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Public key not found: ' . $keyId,
+                Crypt_GPG::ERROR_KEY_NOT_FOUND, $keyId);
+        }
+
+        $keyData   = '';
+        $operation = '--export ' . escapeshellarg($fingerprint);
+        $arguments = ($armor) ? array('--armor') : array();
+
+        $this->engine->reset();
+        $this->engine->setOutput($keyData);
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        $code = $this->engine->getErrorCode();
+
+        if ($code !== Crypt_GPG::ERROR_NONE) {
+            throw new Crypt_GPG_Exception(
+                'Unknown error exporting public key. Please use the ' .
+                '\'debug\' option when creating the Crypt_GPG object, and ' .
+                'file a bug report at ' . self::BUG_URI, $code);
+        }
+
+        return $keyData;
+    }
+
+    // }}}
+    // {{{ deletePublicKey()
+
+    /**
+     * Deletes a public key from the keyring
+     *
+     * If more than one key fingerprint is available for the specified
+     * <kbd>$keyId</kbd> (for example, if you use a non-unique uid) only the
+     * first public key is deleted.
+     *
+     * The private key must be deleted first or an exception will be thrown.
+     * See {@link Crypt_GPG::deletePrivateKey()}.
+     *
+     * @param string $keyId either the full uid of the public key, the email
+     *                      part of the uid of the public key or the key id of
+     *                      the public key. For example,
+     *                      "Test User (example) <test@example.com>",
+     *                      "test@example.com" or a hexadecimal string.
+     *
+     * @return void
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if a public key with the given
+     *         <kbd>$keyId</kbd> is not found.
+     *
+     * @throws Crypt_GPG_DeletePrivateKeyException if the specified public key
+     *         has an associated private key on the keyring. The private key
+     *         must be deleted first.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function deletePublicKey($keyId)
+    {
+        $fingerprint = $this->getFingerprint($keyId);
+
+        if ($fingerprint === null) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Public key not found: ' . $keyId,
+                Crypt_GPG::ERROR_KEY_NOT_FOUND, $keyId);
+        }
+
+        $operation = '--delete-key ' . escapeshellarg($fingerprint);
+        $arguments = array(
+            '--batch',
+            '--yes'
+        );
+
+        $this->engine->reset();
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+            break;
+        case Crypt_GPG::ERROR_DELETE_PRIVATE_KEY:
+            throw new Crypt_GPG_DeletePrivateKeyException(
+                'Private key must be deleted before public key can be ' .
+                'deleted.', $code, $keyId);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error deleting public key. Please use the ' .
+                '\'debug\' option when creating the Crypt_GPG object, and ' .
+                'file a bug report at ' . self::BUG_URI, $code);
+        }
+    }
+
+    // }}}
+    // {{{ deletePrivateKey()
+
+    /**
+     * Deletes a private key from the keyring
+     *
+     * If more than one key fingerprint is available for the specified
+     * <kbd>$keyId</kbd> (for example, if you use a non-unique uid) only the
+     * first private key is deleted.
+     *
+     * Calls GPG with the <kbd>--delete-secret-key</kbd> command.
+     *
+     * @param string $keyId either the full uid of the private key, the email
+     *                      part of the uid of the private key or the key id of
+     *                      the private key. For example,
+     *                      "Test User (example) <test@example.com>",
+     *                      "test@example.com" or a hexadecimal string.
+     *
+     * @return void
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if a private key with the given
+     *         <kbd>$keyId</kbd> is not found.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function deletePrivateKey($keyId)
+    {
+        $fingerprint = $this->getFingerprint($keyId);
+
+        if ($fingerprint === null) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Private key not found: ' . $keyId,
+                Crypt_GPG::ERROR_KEY_NOT_FOUND, $keyId);
+        }
+
+        $operation = '--delete-secret-key ' . escapeshellarg($fingerprint);
+        $arguments = array(
+            '--batch',
+            '--yes'
+        );
+
+        $this->engine->reset();
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+            break;
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Private key not found: ' . $keyId,
+                $code, $keyId);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error deleting private key. Please use the ' .
+                '\'debug\' option when creating the Crypt_GPG object, and ' .
+                'file a bug report at ' . self::BUG_URI, $code);
+        }
+    }
+
+    // }}}
+    // {{{ getKeys()
+
+    /**
+     * Gets the available keys in the keyring
+     *
+     * Calls GPG with the <kbd>--list-keys</kbd> command and grabs keys. See
+     * the first section of <b>doc/DETAILS</b> in the
+     * {@link http://www.gnupg.org/download/ GPG package} for a detailed
+     * description of how the GPG command output is parsed.
+     *
+     * @param string $keyId optional. Only keys with that match the specified
+     *                      pattern are returned. The pattern may be part of
+     *                      a user id, a key id or a key fingerprint. If not
+     *                      specified, all keys are returned.
+     *
+     * @return array an array of {@link Crypt_GPG_Key} objects. If no keys
+     *               match the specified <kbd>$keyId</kbd> an empty array is
+     *               returned.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG_Key
+     */
+    public function getKeys($keyId = '')
+    {
+        // get private key fingerprints
+        if ($keyId == '') {
+            $operation = '--list-secret-keys';
+        } else {
+            $operation = '--list-secret-keys ' . escapeshellarg($keyId);
+        }
+
+        // According to The file 'doc/DETAILS' in the GnuPG distribution, using
+        // double '--with-fingerprint' also prints the fingerprint for subkeys.
+        $arguments = array(
+            '--with-colons',
+            '--with-fingerprint',
+            '--with-fingerprint',
+            '--fixed-list-mode'
+        );
+
+        $output = '';
+
+        $this->engine->reset();
+        $this->engine->setOutput($output);
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            // ignore not found key errors
+            break;
+        case Crypt_GPG::ERROR_FILE_PERMISSIONS:
+            $filename = $this->engine->getErrorFilename();
+            if ($filename) {
+                throw new Crypt_GPG_FileException(sprintf(
+                    'Error reading GnuPG data file \'%s\'. Check to make ' .
+                    'sure it is readable by the current user.', $filename),
+                    $code, $filename);
+            }
+            throw new Crypt_GPG_FileException(
+                'Error reading GnuPG data file. Check to make GnuPG data ' .
+                'files are readable by the current user.', $code);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error getting keys. Please use the \'debug\' option ' .
+                'when creating the Crypt_GPG object, and file a bug report ' .
+                'at ' . self::BUG_URI, $code);
+        }
+
+        $privateKeyFingerprints = array();
+
+        $lines = explode(PHP_EOL, $output);
+        foreach ($lines as $line) {
+            $lineExp = explode(':', $line);
+            if ($lineExp[0] == 'fpr') {
+                $privateKeyFingerprints[] = $lineExp[9];
+            }
+        }
+
+        // get public keys
+        if ($keyId == '') {
+            $operation = '--list-public-keys';
+        } else {
+            $operation = '--list-public-keys ' . escapeshellarg($keyId);
+        }
+
+        $output = '';
+
+        $this->engine->reset();
+        $this->engine->setOutput($output);
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            // ignore not found key errors
+            break;
+        case Crypt_GPG::ERROR_FILE_PERMISSIONS:
+            $filename = $this->engine->getErrorFilename();
+            if ($filename) {
+                throw new Crypt_GPG_FileException(sprintf(
+                    'Error reading GnuPG data file \'%s\'. Check to make ' .
+                    'sure it is readable by the current user.', $filename),
+                    $code, $filename);
+            }
+            throw new Crypt_GPG_FileException(
+                'Error reading GnuPG data file. Check to make GnuPG data ' .
+                'files are readable by the current user.', $code);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error getting keys. Please use the \'debug\' option ' .
+                'when creating the Crypt_GPG object, and file a bug report ' .
+                'at ' . self::BUG_URI, $code);
+        }
+
+        $keys = array();
+
+        $key    = null; // current key
+        $subKey = null; // current sub-key
+
+        $lines = explode(PHP_EOL, $output);
+        foreach ($lines as $line) {
+            $lineExp = explode(':', $line);
+
+            if ($lineExp[0] == 'pub') {
+
+                // new primary key means last key should be added to the array
+                if ($key !== null) {
+                    $keys[] = $key;
+                }
+
+                $key = new Crypt_GPG_Key();
+
+                $subKey = Crypt_GPG_SubKey::parse($line);
+                $key->addSubKey($subKey);
+
+            } elseif ($lineExp[0] == 'sub') {
+
+                $subKey = Crypt_GPG_SubKey::parse($line);
+                $key->addSubKey($subKey);
+
+            } elseif ($lineExp[0] == 'fpr') {
+
+                $fingerprint = $lineExp[9];
+
+                // set current sub-key fingerprint
+                $subKey->setFingerprint($fingerprint);
+
+                // if private key exists, set has private to true
+                if (in_array($fingerprint, $privateKeyFingerprints)) {
+                    $subKey->setHasPrivate(true);
+                }
+
+            } elseif ($lineExp[0] == 'uid') {
+
+                $string = stripcslashes($lineExp[9]); // as per documentation
+                $userId = new Crypt_GPG_UserId($string);
+
+                if ($lineExp[1] == 'r') {
+                    $userId->setRevoked(true);
+                }
+
+                $key->addUserId($userId);
+
+            }
+        }
+
+        // add last key
+        if ($key !== null) {
+            $keys[] = $key;
+        }
+
+        return $keys;
+    }
+
+    // }}}
+    // {{{ getFingerprint()
+
+    /**
+     * Gets a key fingerprint from the keyring
+     *
+     * If more than one key fingerprint is available (for example, if you use
+     * a non-unique user id) only the first key fingerprint is returned.
+     *
+     * Calls the GPG <kbd>--list-keys</kbd> command with the
+     * <kbd>--with-fingerprint</kbd> option to retrieve a public key
+     * fingerprint.
+     *
+     * @param string  $keyId  either the full user id of the key, the email
+     *                        part of the user id of the key, or the key id of
+     *                        the key. For example,
+     *                        "Test User (example) <test@example.com>",
+     *                        "test@example.com" or a hexadecimal string.
+     * @param integer $format optional. How the fingerprint should be formatted.
+     *                        Use {@link Crypt_GPG::FORMAT_X509} for X.509
+     *                        certificate format,
+     *                        {@link Crypt_GPG::FORMAT_CANONICAL} for the format
+     *                        used by GnuPG output and
+     *                        {@link Crypt_GPG::FORMAT_NONE} for no formatting.
+     *                        Defaults to <code>Crypt_GPG::FORMAT_NONE</code>.
+     *
+     * @return string the fingerprint of the key, or null if no fingerprint
+     *                is found for the given <kbd>$keyId</kbd>.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function getFingerprint($keyId, $format = Crypt_GPG::FORMAT_NONE)
+    {
+        $output    = '';
+        $operation = '--list-keys ' . escapeshellarg($keyId);
+        $arguments = array(
+            '--with-colons',
+            '--with-fingerprint'
+        );
+
+        $this->engine->reset();
+        $this->engine->setOutput($output);
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            // ignore not found key errors
+            break;
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error getting key fingerprint. Please use the ' .
+                '\'debug\' option when creating the Crypt_GPG object, and ' .
+                'file a bug report at ' . self::BUG_URI, $code);
+        }
+
+        $fingerprint = null;
+
+        $lines = explode(PHP_EOL, $output);
+        foreach ($lines as $line) {
+            if (substr($line, 0, 3) == 'fpr') {
+                $lineExp     = explode(':', $line);
+                $fingerprint = $lineExp[9];
+
+                switch ($format) {
+                case Crypt_GPG::FORMAT_CANONICAL:
+                    $fingerprintExp = str_split($fingerprint, 4);
+                    $format         = '%s %s %s %s %s  %s %s %s %s %s';
+                    $fingerprint    = vsprintf($format, $fingerprintExp);
+                    break;
+
+                case Crypt_GPG::FORMAT_X509:
+                    $fingerprintExp = str_split($fingerprint, 2);
+                    $fingerprint    = implode(':', $fingerprintExp);
+                    break;
+                }
+
+                break;
+            }
+        }
+
+        return $fingerprint;
+    }
+
+    // }}}
+    // {{{ encrypt()
+
+    /**
+     * Encrypts string data
+     *
+     * Data is ASCII armored by default but may optionally be returned as
+     * binary.
+     *
+     * @param string  $data  the data to be encrypted.
+     * @param boolean $armor optional. If true, ASCII armored data is returned;
+     *                       otherwise, binary data is returned. Defaults to
+     *                       true.
+     *
+     * @return string the encrypted data.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no encryption key is specified.
+     *         See {@link Crypt_GPG::addEncryptKey()}.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @sensitive $data
+     */
+    public function encrypt($data, $armor = true)
+    {
+        return $this->_encrypt($data, false, null, $armor);
+    }
+
+    // }}}
+    // {{{ encryptFile()
+
+    /**
+     * Encrypts a file
+     *
+     * Encrypted data is ASCII armored by default but may optionally be saved
+     * as binary.
+     *
+     * @param string  $filename      the filename of the file to encrypt.
+     * @param string  $encryptedFile optional. The filename of the file in
+     *                               which to store the encrypted data. If null
+     *                               or unspecified, the encrypted data is
+     *                               returned as a string.
+     * @param boolean $armor         optional. If true, ASCII armored data is
+     *                               returned; otherwise, binary data is
+     *                               returned. Defaults to true.
+     *
+     * @return void|string if the <kbd>$encryptedFile</kbd> parameter is null,
+     *                     a string containing the encrypted data is returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no encryption key is specified.
+     *         See {@link Crypt_GPG::addEncryptKey()}.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function encryptFile($filename, $encryptedFile = null, $armor = true)
+    {
+        return $this->_encrypt($filename, true, $encryptedFile, $armor);
+    }
+
+    // }}}
+    // {{{ encryptAndSign()
+
+    /**
+     * Encrypts and signs data
+     *
+     * Data is encrypted and signed in a single pass.
+     *
+     * NOTE: Until GnuPG version 1.4.10, it was not possible to verify
+     * encrypted-signed data without decrypting it at the same time. If you try
+     * to use {@link Crypt_GPG::verify()} method on encrypted-signed data with
+     * earlier GnuPG versions, you will get an error. Please use
+     * {@link Crypt_GPG::decryptAndVerify()} to verify encrypted-signed data.
+     *
+     * @param string  $data  the data to be encrypted and signed.
+     * @param boolean $armor optional. If true, ASCII armored data is returned;
+     *                       otherwise, binary data is returned. Defaults to
+     *                       true.
+     *
+     * @return string the encrypted signed data.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no encryption key is specified
+     *         or if no signing key is specified. See
+     *         {@link Crypt_GPG::addEncryptKey()} and
+     *         {@link Crypt_GPG::addSignKey()}.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a specified passphrase is
+     *         incorrect or if a required passphrase is not specified.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG::decryptAndVerify()
+     */
+    public function encryptAndSign($data, $armor = true)
+    {
+        return $this->_encryptAndSign($data, false, null, $armor);
+    }
+
+    // }}}
+    // {{{ encryptAndSignFile()
+
+    /**
+     * Encrypts and signs a file
+     *
+     * The file is encrypted and signed in a single pass.
+     *
+     * NOTE: Until GnuPG version 1.4.10, it was not possible to verify
+     * encrypted-signed files without decrypting them at the same time. If you
+     * try to use {@link Crypt_GPG::verify()} method on encrypted-signed files
+     * with earlier GnuPG versions, you will get an error. Please use
+     * {@link Crypt_GPG::decryptAndVerifyFile()} to verify encrypted-signed
+     * files.
+     *
+     * @param string  $filename   the name of the file containing the data to
+     *                            be encrypted and signed.
+     * @param string  $signedFile optional. The name of the file in which the
+     *                            encrypted, signed data should be stored. If
+     *                            null or unspecified, the encrypted, signed
+     *                            data is returned as a string.
+     * @param boolean $armor      optional. If true, ASCII armored data is
+     *                            returned; otherwise, binary data is returned.
+     *                            Defaults to true.
+     *
+     * @return void|string if the <kbd>$signedFile</kbd> parameter is null, a
+     *                     string containing the encrypted, signed data is
+     *                     returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no encryption key is specified
+     *         or if no signing key is specified. See
+     *         {@link Crypt_GPG::addEncryptKey()} and
+     *         {@link Crypt_GPG::addSignKey()}.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a specified passphrase is
+     *         incorrect or if a required passphrase is not specified.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG::decryptAndVerifyFile()
+     */
+    public function encryptAndSignFile($filename, $signedFile = null,
+        $armor = true
+    ) {
+        return $this->_encryptAndSign($filename, true, $signedFile, $armor);
+    }
+
+    // }}}
+    // {{{ decrypt()
+
+    /**
+     * Decrypts string data
+     *
+     * This method assumes the required private key is available in the keyring
+     * and throws an exception if the private key is not available. To add a
+     * private key to the keyring, use the {@link Crypt_GPG::importKey()} or
+     * {@link Crypt_GPG::importKeyFile()} methods.
+     *
+     * @param string $encryptedData the data to be decrypted.
+     *
+     * @return string the decrypted data.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if the private key needed to
+     *         decrypt the data is not in the user's keyring.
+     *
+     * @throws Crypt_GPG_NoDataException if specified data does not contain
+     *         GPG encrypted data.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a required passphrase is
+     *         incorrect or if a required passphrase is not specified. See
+     *         {@link Crypt_GPG::addDecryptKey()}.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function decrypt($encryptedData)
+    {
+        return $this->_decrypt($encryptedData, false, null);
+    }
+
+    // }}}
+    // {{{ decryptFile()
+
+    /**
+     * Decrypts a file
+     *
+     * This method assumes the required private key is available in the keyring
+     * and throws an exception if the private key is not available. To add a
+     * private key to the keyring, use the {@link Crypt_GPG::importKey()} or
+     * {@link Crypt_GPG::importKeyFile()} methods.
+     *
+     * @param string $encryptedFile the name of the encrypted file data to
+     *                              decrypt.
+     * @param string $decryptedFile optional. The name of the file to which the
+     *                              decrypted data should be written. If null
+     *                              or unspecified, the decrypted data is
+     *                              returned as a string.
+     *
+     * @return void|string if the <kbd>$decryptedFile</kbd> parameter is null,
+     *                     a string containing the decrypted data is returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if the private key needed to
+     *         decrypt the data is not in the user's keyring.
+     *
+     * @throws Crypt_GPG_NoDataException if specified data does not contain
+     *         GPG encrypted data.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a required passphrase is
+     *         incorrect or if a required passphrase is not specified. See
+     *         {@link Crypt_GPG::addDecryptKey()}.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function decryptFile($encryptedFile, $decryptedFile = null)
+    {
+        return $this->_decrypt($encryptedFile, true, $decryptedFile);
+    }
+
+    // }}}
+    // {{{ decryptAndVerify()
+
+    /**
+     * Decrypts and verifies string data
+     *
+     * This method assumes the required private key is available in the keyring
+     * and throws an exception if the private key is not available. To add a
+     * private key to the keyring, use the {@link Crypt_GPG::importKey()} or
+     * {@link Crypt_GPG::importKeyFile()} methods.
+     *
+     * @param string $encryptedData the encrypted, signed data to be decrypted
+     *                              and verified.
+     *
+     * @return array two element array. The array has an element 'data'
+     *               containing the decrypted data and an element
+     *               'signatures' containing an array of
+     *               {@link Crypt_GPG_Signature} objects for the signed data.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if the private key needed to
+     *         decrypt the data is not in the user's keyring.
+     *
+     * @throws Crypt_GPG_NoDataException if specified data does not contain
+     *         GPG encrypted data.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a required passphrase is
+     *         incorrect or if a required passphrase is not specified. See
+     *         {@link Crypt_GPG::addDecryptKey()}.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function decryptAndVerify($encryptedData)
+    {
+        return $this->_decryptAndVerify($encryptedData, false, null);
+    }
+
+    // }}}
+    // {{{ decryptAndVerifyFile()
+
+    /**
+     * Decrypts and verifies a signed, encrypted file
+     *
+     * This method assumes the required private key is available in the keyring
+     * and throws an exception if the private key is not available. To add a
+     * private key to the keyring, use the {@link Crypt_GPG::importKey()} or
+     * {@link Crypt_GPG::importKeyFile()} methods.
+     *
+     * @param string $encryptedFile the name of the signed, encrypted file to
+     *                              to decrypt and verify.
+     * @param string $decryptedFile optional. The name of the file to which the
+     *                              decrypted data should be written. If null
+     *                              or unspecified, the decrypted data is
+     *                              returned in the results array.
+     *
+     * @return array two element array. The array has an element 'data'
+     *               containing the decrypted data and an element
+     *               'signatures' containing an array of
+     *               {@link Crypt_GPG_Signature} objects for the signed data.
+     *               If the decrypted data is written to a file, the 'data'
+     *               element is null.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if the private key needed to
+     *         decrypt the data is not in the user's keyring.
+     *
+     * @throws Crypt_GPG_NoDataException if specified data does not contain
+     *         GPG encrypted data.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a required passphrase is
+     *         incorrect or if a required passphrase is not specified. See
+     *         {@link Crypt_GPG::addDecryptKey()}.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function decryptAndVerifyFile($encryptedFile, $decryptedFile = null)
+    {
+        return $this->_decryptAndVerify($encryptedFile, true, $decryptedFile);
+    }
+
+    // }}}
+    // {{{ sign()
+
+    /**
+     * Signs data
+     *
+     * Data may be signed using any one of the three available signing modes:
+     * - {@link Crypt_GPG::SIGN_MODE_NORMAL}
+     * - {@link Crypt_GPG::SIGN_MODE_CLEAR}
+     * - {@link Crypt_GPG::SIGN_MODE_DETACHED}
+     *
+     * @param string  $data     the data to be signed.
+     * @param boolean $mode     optional. The data signing mode to use. Should
+     *                          be one of {@link Crypt_GPG::SIGN_MODE_NORMAL},
+     *                          {@link Crypt_GPG::SIGN_MODE_CLEAR} or
+     *                          {@link Crypt_GPG::SIGN_MODE_DETACHED}. If not
+     *                          specified, defaults to
+     *                          <kbd>Crypt_GPG::SIGN_MODE_NORMAL</kbd>.
+     * @param boolean $armor    optional. If true, ASCII armored data is
+     *                          returned; otherwise, binary data is returned.
+     *                          Defaults to true. This has no effect if the
+     *                          mode <kbd>Crypt_GPG::SIGN_MODE_CLEAR</kbd> is
+     *                          used.
+     * @param boolean $textmode optional. If true, line-breaks in signed data
+     *                          are normalized. Use this option when signing
+     *                          e-mail, or for greater compatibility between
+     *                          systems with different line-break formats.
+     *                          Defaults to false. This has no effect if the
+     *                          mode <kbd>Crypt_GPG::SIGN_MODE_CLEAR</kbd> is
+     *                          used as clear-signing always uses textmode.
+     *
+     * @return string the signed data, or the signature data if a detached
+     *                signature is requested.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no signing key is specified.
+     *         See {@link Crypt_GPG::addSignKey()}.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a specified passphrase is
+     *         incorrect or if a required passphrase is not specified.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function sign($data, $mode = Crypt_GPG::SIGN_MODE_NORMAL,
+        $armor = true, $textmode = false
+    ) {
+        return $this->_sign($data, false, null, $mode, $armor, $textmode);
+    }
+
+    // }}}
+    // {{{ signFile()
+
+    /**
+     * Signs a file
+     *
+     * The file may be signed using any one of the three available signing
+     * modes:
+     * - {@link Crypt_GPG::SIGN_MODE_NORMAL}
+     * - {@link Crypt_GPG::SIGN_MODE_CLEAR}
+     * - {@link Crypt_GPG::SIGN_MODE_DETACHED}
+     *
+     * @param string  $filename   the name of the file containing the data to
+     *                            be signed.
+     * @param string  $signedFile optional. The name of the file in which the
+     *                            signed data should be stored. If null or
+     *                            unspecified, the signed data is returned as a
+     *                            string.
+     * @param boolean $mode       optional. The data signing mode to use. Should
+     *                            be one of {@link Crypt_GPG::SIGN_MODE_NORMAL},
+     *                            {@link Crypt_GPG::SIGN_MODE_CLEAR} or
+     *                            {@link Crypt_GPG::SIGN_MODE_DETACHED}. If not
+     *                            specified, defaults to
+     *                            <kbd>Crypt_GPG::SIGN_MODE_NORMAL</kbd>.
+     * @param boolean $armor      optional. If true, ASCII armored data is
+     *                            returned; otherwise, binary data is returned.
+     *                            Defaults to true. This has no effect if the
+     *                            mode <kbd>Crypt_GPG::SIGN_MODE_CLEAR</kbd> is
+     *                            used.
+     * @param boolean $textmode   optional. If true, line-breaks in signed data
+     *                            are normalized. Use this option when signing
+     *                            e-mail, or for greater compatibility between
+     *                            systems with different line-break formats.
+     *                            Defaults to false. This has no effect if the
+     *                            mode <kbd>Crypt_GPG::SIGN_MODE_CLEAR</kbd> is
+     *                            used as clear-signing always uses textmode.
+     *
+     * @return void|string if the <kbd>$signedFile</kbd> parameter is null, a
+     *                     string containing the signed data (or the signature
+     *                     data if a detached signature is requested) is
+     *                     returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no signing key is specified.
+     *         See {@link Crypt_GPG::addSignKey()}.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a specified passphrase is
+     *         incorrect or if a required passphrase is not specified.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    public function signFile($filename, $signedFile = null,
+        $mode = Crypt_GPG::SIGN_MODE_NORMAL, $armor = true, $textmode = false
+    ) {
+        return $this->_sign(
+            $filename,
+            true,
+            $signedFile,
+            $mode,
+            $armor,
+            $textmode
+        );
+    }
+
+    // }}}
+    // {{{ verify()
+
+    /**
+     * Verifies signed data
+     *
+     * The {@link Crypt_GPG::decrypt()} method may be used to get the original
+     * message if the signed data is not clearsigned and does not use a
+     * detached signature.
+     *
+     * @param string $signedData the signed data to be verified.
+     * @param string $signature  optional. If verifying data signed using a
+     *                           detached signature, this must be the detached
+     *                           signature data. The data that was signed is
+     *                           specified in <kbd>$signedData</kbd>.
+     *
+     * @return array an array of {@link Crypt_GPG_Signature} objects for the
+     *               signed data. For each signature that is valid, the
+     *               {@link Crypt_GPG_Signature::isValid()} will return true.
+     *
+     * @throws Crypt_GPG_NoDataException if the provided data is not signed
+     *         data.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG_Signature
+     */
+    public function verify($signedData, $signature = '')
+    {
+        return $this->_verify($signedData, false, $signature);
+    }
+
+    // }}}
+    // {{{ verifyFile()
+
+    /**
+     * Verifies a signed file
+     *
+     * The {@link Crypt_GPG::decryptFile()} method may be used to get the
+     * original message if the signed data is not clearsigned and does not use
+     * a detached signature.
+     *
+     * @param string $filename  the signed file to be verified.
+     * @param string $signature optional. If verifying a file signed using a
+     *                          detached signature, this must be the detached
+     *                          signature data. The file that was signed is
+     *                          specified in <kbd>$filename</kbd>.
+     *
+     * @return array an array of {@link Crypt_GPG_Signature} objects for the
+     *               signed data. For each signature that is valid, the
+     *               {@link Crypt_GPG_Signature::isValid()} will return true.
+     *
+     * @throws Crypt_GPG_NoDataException if the provided data is not signed
+     *         data.
+     *
+     * @throws Crypt_GPG_FileException if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG_Signature
+     */
+    public function verifyFile($filename, $signature = '')
+    {
+        return $this->_verify($filename, true, $signature);
+    }
+
+    // }}}
+    // {{{ addDecryptKey()
+
+    /**
+     * Adds a key to use for decryption
+     *
+     * @param mixed  $key        the key to use. This may be a key identifier,
+     *                           user id, fingerprint, {@link Crypt_GPG_Key} or
+     *                           {@link Crypt_GPG_SubKey}. The key must be able
+     *                           to encrypt.
+     * @param string $passphrase optional. The passphrase of the key required
+     *                           for decryption.
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::decrypt()
+     * @see Crypt_GPG::decryptFile()
+     * @see Crypt_GPG::clearDecryptKeys()
+     * @see Crypt_GPG::_addKey()
+     * @see Crypt_GPG_DecryptStatusHandler
+     *
+     * @sensitive $passphrase
+     */
+    public function addDecryptKey($key, $passphrase = null)
+    {
+        $this->_addKey($this->decryptKeys, true, false, $key, $passphrase);
+    }
+
+    // }}}
+    // {{{ addEncryptKey()
+
+    /**
+     * Adds a key to use for encryption
+     *
+     * @param mixed $key the key to use. This may be a key identifier, user id
+     *                   user id, fingerprint, {@link Crypt_GPG_Key} or
+     *                   {@link Crypt_GPG_SubKey}. The key must be able to
+     *                   encrypt.
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::encrypt()
+     * @see Crypt_GPG::encryptFile()
+     * @see Crypt_GPG::clearEncryptKeys()
+     * @see Crypt_GPG::_addKey()
+     */
+    public function addEncryptKey($key)
+    {
+        $this->_addKey($this->encryptKeys, true, false, $key);
+    }
+
+    // }}}
+    // {{{ addSignKey()
+
+    /**
+     * Adds a key to use for signing
+     *
+     * @param mixed  $key        the key to use. This may be a key identifier,
+     *                           user id, fingerprint, {@link Crypt_GPG_Key} or
+     *                           {@link Crypt_GPG_SubKey}. The key must be able
+     *                           to sign.
+     * @param string $passphrase optional. The passphrase of the key required
+     *                           for signing.
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::sign()
+     * @see Crypt_GPG::signFile()
+     * @see Crypt_GPG::clearSignKeys()
+     * @see Crypt_GPG::handleSignStatus()
+     * @see Crypt_GPG::_addKey()
+     *
+     * @sensitive $passphrase
+     */
+    public function addSignKey($key, $passphrase = null)
+    {
+        $this->_addKey($this->signKeys, false, true, $key, $passphrase);
+    }
+
+    // }}}
+    // {{{ clearDecryptKeys()
+
+    /**
+     * Clears all decryption keys
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::decrypt()
+     * @see Crypt_GPG::addDecryptKey()
+     */
+    public function clearDecryptKeys()
+    {
+        $this->decryptKeys = array();
+    }
+
+    // }}}
+    // {{{ clearEncryptKeys()
+
+    /**
+     * Clears all encryption keys
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::encrypt()
+     * @see Crypt_GPG::addEncryptKey()
+     */
+    public function clearEncryptKeys()
+    {
+        $this->encryptKeys = array();
+    }
+
+    // }}}
+    // {{{ clearSignKeys()
+
+    /**
+     * Clears all signing keys
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::sign()
+     * @see Crypt_GPG::addSignKey()
+     */
+    public function clearSignKeys()
+    {
+        $this->signKeys = array();
+    }
+
+    // }}}
+    // {{{ handleSignStatus()
+
+    /**
+     * Handles the status output from GPG for the sign operation
+     *
+     * This method is responsible for sending the passphrase commands when
+     * required by the {@link Crypt_GPG::sign()} method. See <b>doc/DETAILS</b>
+     * in the {@link http://www.gnupg.org/download/ GPG distribution} for
+     * detailed information on GPG's status output.
+     *
+     * @param string $line the status line to handle.
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::sign()
+     */
+    public function handleSignStatus($line)
+    {
+        $tokens = explode(' ', $line);
+        switch ($tokens[0]) {
+        case 'NEED_PASSPHRASE':
+            $subKeyId = $tokens[1];
+            if (array_key_exists($subKeyId, $this->signKeys)) {
+                $passphrase = $this->signKeys[$subKeyId]['passphrase'];
+                $this->engine->sendCommand($passphrase);
+            } else {
+                $this->engine->sendCommand('');
+            }
+            break;
+        }
+    }
+
+    // }}}
+    // {{{ handleImportKeyStatus()
+
+    /**
+     * Handles the status output from GPG for the import operation
+     *
+     * This method is responsible for building the result array that is
+     * returned from the {@link Crypt_GPG::importKey()} method. See
+     * <b>doc/DETAILS</b> in the
+     * {@link http://www.gnupg.org/download/ GPG distribution} for detailed
+     * information on GPG's status output.
+     *
+     * @param string $line    the status line to handle.
+     * @param array  &$result the current result array being processed.
+     *
+     * @return void
+     *
+     * @see Crypt_GPG::importKey()
+     * @see Crypt_GPG::importKeyFile()
+     * @see Crypt_GPG_Engine::addStatusHandler()
+     */
+    public function handleImportKeyStatus($line, array &$result)
+    {
+        $tokens = explode(' ', $line);
+        switch ($tokens[0]) {
+        case 'IMPORT_OK':
+            $result['fingerprint'] = $tokens[2];
+            break;
+
+        case 'IMPORT_RES':
+            $result['public_imported']   = intval($tokens[3]);
+            $result['public_unchanged']  = intval($tokens[5]);
+            $result['private_imported']  = intval($tokens[11]);
+            $result['private_unchanged'] = intval($tokens[12]);
+            break;
+        }
+    }
+
+    // }}}
+    // {{{ setEngine()
+
+    /**
+     * Sets the I/O engine to use for GnuPG operations
+     *
+     * Normally this method does not need to be used. It provides a means for
+     * dependency injection.
+     *
+     * @param Crypt_GPG_Engine $engine the engine to use.
+     *
+     * @return void
+     */
+    public function setEngine(Crypt_GPG_Engine $engine)
+    {
+        $this->engine = $engine;
+    }
+
+    // }}}
+    // {{{ _addKey()
+
+    /**
+     * Adds a key to one of the internal key arrays
+     *
+     * This handles resolving full key objects from the provided
+     * <kbd>$key</kbd> value.
+     *
+     * @param array   &$array     the array to which the key should be added.
+     * @param boolean $encrypt    whether or not the key must be able to
+     *                            encrypt.
+     * @param boolean $sign       whether or not the key must be able to sign.
+     * @param mixed   $key        the key to add. This may be a key identifier,
+     *                            user id, fingerprint, {@link Crypt_GPG_Key} or
+     *                            {@link Crypt_GPG_SubKey}.
+     * @param string  $passphrase optional. The passphrase associated with the
+     *                            key.
+     *
+     * @return void
+     *
+     * @sensitive $passphrase
+     */
+    private function _addKey(array &$array, $encrypt, $sign, $key,
+        $passphrase = null
+    ) {
+        $subKeys = array();
+
+        if (is_scalar($key)) {
+            $keys = $this->getKeys($key);
+            if (count($keys) == 0) {
+                throw new Crypt_GPG_KeyNotFoundException(
+                    'Key "' . $key . '" not found.', 0, $key);
+            }
+            $key = $keys[0];
+        }
+
+        if ($key instanceof Crypt_GPG_Key) {
+            if ($encrypt && !$key->canEncrypt()) {
+                throw new InvalidArgumentException(
+                    'Key "' . $key . '" cannot encrypt.');
+            }
+
+            if ($sign && !$key->canSign()) {
+                throw new InvalidArgumentException(
+                    'Key "' . $key . '" cannot sign.');
+            }
+
+            foreach ($key->getSubKeys() as $subKey) {
+                $canEncrypt = $subKey->canEncrypt();
+                $canSign    = $subKey->canSign();
+                if (   ($encrypt && $sign && $canEncrypt && $canSign)
+                    || ($encrypt && !$sign && $canEncrypt)
+                    || (!$encrypt && $sign && $canSign)
+                ) {
+                    // We add all subkeys that meet the requirements because we
+                    // were not told which subkey is required.
+                    $subKeys[] = $subKey;
+                }
+            }
+        } elseif ($key instanceof Crypt_GPG_SubKey) {
+            $subKeys[] = $key;
+        }
+
+        if (count($subKeys) === 0) {
+            throw new InvalidArgumentException(
+                'Key "' . $key . '" is not in a recognized format.');
+        }
+
+        foreach ($subKeys as $subKey) {
+            if ($encrypt && !$subKey->canEncrypt()) {
+                throw new InvalidArgumentException(
+                    'Key "' . $key . '" cannot encrypt.');
+            }
+
+            if ($sign && !$subKey->canSign()) {
+                throw new InvalidArgumentException(
+                    'Key "' . $key . '" cannot sign.');
+            }
+
+            $array[$subKey->getId()] = array(
+                'fingerprint' => $subKey->getFingerprint(),
+                'passphrase'  => $passphrase
+            );
+        }
+    }
+
+    // }}}
+    // {{{ _importKey()
+
+    /**
+     * Imports a public or private key into the keyring
+     *
+     * @param string  $key    the key to be imported.
+     * @param boolean $isFile whether or not the input is a filename.
+     *
+     * @return array an associative array containing the following elements:
+     *               - <kbd>fingerprint</kbd>       - the fingerprint of the
+     *                                                imported key,
+     *               - <kbd>public_imported</kbd>   - the number of public
+     *                                                keys imported,
+     *               - <kbd>public_unchanged</kbd>  - the number of unchanged
+     *                                                public keys,
+     *               - <kbd>private_imported</kbd>  - the number of private
+     *                                                keys imported,
+     *               - <kbd>private_unchanged</kbd> - the number of unchanged
+     *                                                private keys.
+     *
+     * @throws Crypt_GPG_NoDataException if the key data is missing or if the
+     *         data is is not valid key data.
+     *
+     * @throws Crypt_GPG_FileException if the key file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    private function _importKey($key, $isFile)
+    {
+        $result = array();
+
+        if ($isFile) {
+            $input = @fopen($key, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open key file "' .
+                    $key . '" for importing.', 0, $key);
+            }
+        } else {
+            $input = strval($key);
+            if ($input == '') {
+                throw new Crypt_GPG_NoDataException(
+                    'No valid GPG key data found.', Crypt_GPG::ERROR_NO_DATA);
+            }
+        }
+
+        $arguments = array();
+        $version   = $this->engine->getVersion();
+
+        if (   version_compare($version, '1.0.5', 'ge')
+            && version_compare($version, '1.0.7', 'lt')
+        ) {
+            $arguments[] = '--allow-secret-key-import';
+        }
+
+        $this->engine->reset();
+        $this->engine->addStatusHandler(
+            array($this, 'handleImportKeyStatus'),
+            array(&$result)
+        );
+
+        $this->engine->setOperation('--import', $arguments);
+        $this->engine->setInput($input);
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_DUPLICATE_KEY:
+        case Crypt_GPG::ERROR_NONE:
+            // ignore duplicate key import errors
+            break;
+        case Crypt_GPG::ERROR_NO_DATA:
+            throw new Crypt_GPG_NoDataException(
+                'No valid GPG key data found.', $code);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error importing GPG key. Please use the \'debug\' ' .
+                'option when creating the Crypt_GPG object, and file a bug ' .
+                'report at ' . self::BUG_URI, $code);
+        }
+
+        return $result;
+    }
+
+    // }}}
+    // {{{ _encrypt()
+
+    /**
+     * Encrypts data
+     *
+     * @param string  $data       the data to encrypt.
+     * @param boolean $isFile     whether or not the data is a filename.
+     * @param string  $outputFile the filename of the file in which to store
+     *                            the encrypted data. If null, the encrypted
+     *                            data is returned as a string.
+     * @param boolean $armor      if true, ASCII armored data is returned;
+     *                            otherwise, binary data is returned.
+     *
+     * @return void|string if the <kbd>$outputFile</kbd> parameter is null, a
+     *                     string containing the encrypted data is returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no encryption key is specified.
+     *         See {@link Crypt_GPG::addEncryptKey()}.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    private function _encrypt($data, $isFile, $outputFile, $armor)
+    {
+        if (count($this->encryptKeys) === 0) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'No encryption keys specified.');
+        }
+
+        if ($isFile) {
+            $input = @fopen($data, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open input file "' .
+                    $data . '" for encryption.', 0, $data);
+            }
+        } else {
+            $input = strval($data);
+        }
+
+        if ($outputFile === null) {
+            $output = '';
+        } else {
+            $output = @fopen($outputFile, 'wb');
+            if ($output === false) {
+                if ($isFile) {
+                    fclose($input);
+                }
+                throw new Crypt_GPG_FileException('Could not open output ' .
+                    'file "' . $outputFile . '" for storing encrypted data.',
+                    0, $outputFile);
+            }
+        }
+
+        $arguments = ($armor) ? array('--armor') : array();
+        foreach ($this->encryptKeys as $key) {
+            $arguments[] = '--recipient ' . escapeshellarg($key['fingerprint']);
+        }
+
+        $this->engine->reset();
+        $this->engine->setInput($input);
+        $this->engine->setOutput($output);
+        $this->engine->setOperation('--encrypt', $arguments);
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        if ($outputFile !== null) {
+            fclose($output);
+        }
+
+        $code = $this->engine->getErrorCode();
+
+        if ($code !== Crypt_GPG::ERROR_NONE) {
+            throw new Crypt_GPG_Exception(
+                'Unknown error encrypting data. Please use the \'debug\' ' .
+                'option when creating the Crypt_GPG object, and file a bug ' .
+                'report at ' . self::BUG_URI, $code);
+        }
+
+        if ($outputFile === null) {
+            return $output;
+        }
+    }
+
+    // }}}
+    // {{{ _decrypt()
+
+    /**
+     * Decrypts data
+     *
+     * @param string  $data       the data to be decrypted.
+     * @param boolean $isFile     whether or not the data is a filename.
+     * @param string  $outputFile the name of the file to which the decrypted
+     *                            data should be written. If null, the decrypted
+     *                            data is returned as a string.
+     *
+     * @return void|string if the <kbd>$outputFile</kbd> parameter is null, a
+     *                     string containing the decrypted data is returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if the private key needed to
+     *         decrypt the data is not in the user's keyring.
+     *
+     * @throws Crypt_GPG_NoDataException if specified data does not contain
+     *         GPG encrypted data.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a required passphrase is
+     *         incorrect or if a required passphrase is not specified. See
+     *         {@link Crypt_GPG::addDecryptKey()}.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    private function _decrypt($data, $isFile, $outputFile)
+    {
+        if ($isFile) {
+            $input = @fopen($data, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open input file "' .
+                    $data . '" for decryption.', 0, $data);
+            }
+        } else {
+            $input = strval($data);
+            if ($input == '') {
+                throw new Crypt_GPG_NoDataException(
+                    'Cannot decrypt data. No PGP encrypted data was found in '.
+                    'the provided data.', Crypt_GPG::ERROR_NO_DATA);
+            }
+        }
+
+        if ($outputFile === null) {
+            $output = '';
+        } else {
+            $output = @fopen($outputFile, 'wb');
+            if ($output === false) {
+                if ($isFile) {
+                    fclose($input);
+                }
+                throw new Crypt_GPG_FileException('Could not open output ' .
+                    'file "' . $outputFile . '" for storing decrypted data.',
+                    0, $outputFile);
+            }
+        }
+
+        $handler = new Crypt_GPG_DecryptStatusHandler($this->engine,
+            $this->decryptKeys);
+
+        $this->engine->reset();
+        $this->engine->addStatusHandler(array($handler, 'handle'));
+        $this->engine->setOperation('--decrypt');
+        $this->engine->setInput($input);
+        $this->engine->setOutput($output);
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        if ($outputFile !== null) {
+            fclose($output);
+        }
+
+        // if there was any problem decrypting the data, the handler will
+        // deal with it here.
+        $handler->throwException();
+
+        if ($outputFile === null) {
+            return $output;
+        }
+    }
+
+    // }}}
+    // {{{ _sign()
+
+    /**
+     * Signs data
+     *
+     * @param string  $data       the data to be signed.
+     * @param boolean $isFile     whether or not the data is a filename.
+     * @param string  $outputFile the name of the file in which the signed data
+     *                            should be stored. If null, the signed data is
+     *                            returned as a string.
+     * @param boolean $mode       the data signing mode to use. Should be one of
+     *                            {@link Crypt_GPG::SIGN_MODE_NORMAL},
+     *                            {@link Crypt_GPG::SIGN_MODE_CLEAR} or
+     *                            {@link Crypt_GPG::SIGN_MODE_DETACHED}.
+     * @param boolean $armor      if true, ASCII armored data is returned;
+     *                            otherwise, binary data is returned. This has
+     *                            no effect if the mode
+     *                            <kbd>Crypt_GPG::SIGN_MODE_CLEAR</kbd> is
+     *                            used.
+     * @param boolean $textmode   if true, line-breaks in signed data be
+     *                            normalized. Use this option when signing
+     *                            e-mail, or for greater compatibility between
+     *                            systems with different line-break formats.
+     *                            Defaults to false. This has no effect if the
+     *                            mode <kbd>Crypt_GPG::SIGN_MODE_CLEAR</kbd> is
+     *                            used as clear-signing always uses textmode.
+     *
+     * @return void|string if the <kbd>$outputFile</kbd> parameter is null, a
+     *                     string containing the signed data (or the signature
+     *                     data if a detached signature is requested) is
+     *                     returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no signing key is specified.
+     *         See {@link Crypt_GPG::addSignKey()}.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a specified passphrase is
+     *         incorrect or if a required passphrase is not specified.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    private function _sign($data, $isFile, $outputFile, $mode, $armor,
+        $textmode
+    ) {
+        if (count($this->signKeys) === 0) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'No signing keys specified.');
+        }
+
+        if ($isFile) {
+            $input = @fopen($data, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open input ' .
+                    'file "' . $data . '" for signing.', 0, $data);
+            }
+        } else {
+            $input = strval($data);
+        }
+
+        if ($outputFile === null) {
+            $output = '';
+        } else {
+            $output = @fopen($outputFile, 'wb');
+            if ($output === false) {
+                if ($isFile) {
+                    fclose($input);
+                }
+                throw new Crypt_GPG_FileException('Could not open output ' .
+                    'file "' . $outputFile . '" for storing signed ' .
+                    'data.', 0, $outputFile);
+            }
+        }
+
+        switch ($mode) {
+        case Crypt_GPG::SIGN_MODE_DETACHED:
+            $operation = '--detach-sign';
+            break;
+        case Crypt_GPG::SIGN_MODE_CLEAR:
+            $operation = '--clearsign';
+            break;
+        case Crypt_GPG::SIGN_MODE_NORMAL:
+        default:
+            $operation = '--sign';
+            break;
+        }
+
+        $arguments  = array();
+
+        if ($armor) {
+            $arguments[] = '--armor';
+        }
+        if ($textmode) {
+            $arguments[] = '--textmode';
+        }
+
+        foreach ($this->signKeys as $key) {
+            $arguments[] = '--local-user ' .
+                escapeshellarg($key['fingerprint']);
+        }
+
+        $this->engine->reset();
+        $this->engine->addStatusHandler(array($this, 'handleSignStatus'));
+        $this->engine->setInput($input);
+        $this->engine->setOutput($output);
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        if ($outputFile !== null) {
+            fclose($output);
+        }
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+            break;
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Cannot sign data. Private key not found. Import the '.
+                'private key before trying to sign data.', $code,
+                $this->engine->getErrorKeyId());
+        case Crypt_GPG::ERROR_BAD_PASSPHRASE:
+            throw new Crypt_GPG_BadPassphraseException(
+                'Cannot sign data. Incorrect passphrase provided.', $code);
+        case Crypt_GPG::ERROR_MISSING_PASSPHRASE:
+            throw new Crypt_GPG_BadPassphraseException(
+                'Cannot sign data. No passphrase provided.', $code);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error signing data. Please use the \'debug\' option ' .
+                'when creating the Crypt_GPG object, and file a bug report ' .
+                'at ' . self::BUG_URI, $code);
+        }
+
+        if ($outputFile === null) {
+            return $output;
+        }
+    }
+
+    // }}}
+    // {{{ _encryptAndSign()
+
+    /**
+     * Encrypts and signs data
+     *
+     * @param string  $data       the data to be encrypted and signed.
+     * @param boolean $isFile     whether or not the data is a filename.
+     * @param string  $outputFile the name of the file in which the encrypted,
+     *                            signed data should be stored. If null, the
+     *                            encrypted, signed data is returned as a
+     *                            string.
+     * @param boolean $armor      if true, ASCII armored data is returned;
+     *                            otherwise, binary data is returned.
+     *
+     * @return void|string if the <kbd>$outputFile</kbd> parameter is null, a
+     *                     string containing the encrypted, signed data is
+     *                     returned.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if no encryption key is specified
+     *         or if no signing key is specified. See
+     *         {@link Crypt_GPG::addEncryptKey()} and
+     *         {@link Crypt_GPG::addSignKey()}.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a specified passphrase is
+     *         incorrect or if a required passphrase is not specified.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     */
+    private function _encryptAndSign($data, $isFile, $outputFile, $armor)
+    {
+        if (count($this->signKeys) === 0) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'No signing keys specified.');
+        }
+
+        if (count($this->encryptKeys) === 0) {
+            throw new Crypt_GPG_KeyNotFoundException(
+                'No encryption keys specified.');
+        }
+
+
+        if ($isFile) {
+            $input = @fopen($data, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open input ' .
+                    'file "' . $data . '" for encrypting and signing.', 0,
+                    $data);
+            }
+        } else {
+            $input = strval($data);
+        }
+
+        if ($outputFile === null) {
+            $output = '';
+        } else {
+            $output = @fopen($outputFile, 'wb');
+            if ($output === false) {
+                if ($isFile) {
+                    fclose($input);
+                }
+                throw new Crypt_GPG_FileException('Could not open output ' .
+                    'file "' . $outputFile . '" for storing encrypted, ' .
+                    'signed data.', 0, $outputFile);
+            }
+        }
+
+        $arguments  = ($armor) ? array('--armor') : array();
+
+        foreach ($this->signKeys as $key) {
+            $arguments[] = '--local-user ' .
+                escapeshellarg($key['fingerprint']);
+        }
+
+        foreach ($this->encryptKeys as $key) {
+            $arguments[] = '--recipient ' . escapeshellarg($key['fingerprint']);
+        }
+
+        $this->engine->reset();
+        $this->engine->addStatusHandler(array($this, 'handleSignStatus'));
+        $this->engine->setInput($input);
+        $this->engine->setOutput($output);
+        $this->engine->setOperation('--encrypt --sign', $arguments);
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        if ($outputFile !== null) {
+            fclose($output);
+        }
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+            break;
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Cannot sign encrypted data. Private key not found. Import '.
+                'the private key before trying to sign the encrypted data.',
+                $code, $this->engine->getErrorKeyId());
+        case Crypt_GPG::ERROR_BAD_PASSPHRASE:
+            throw new Crypt_GPG_BadPassphraseException(
+                'Cannot sign encrypted data. Incorrect passphrase provided.',
+                $code);
+        case Crypt_GPG::ERROR_MISSING_PASSPHRASE:
+            throw new Crypt_GPG_BadPassphraseException(
+                'Cannot sign encrypted data. No passphrase provided.', $code);
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error encrypting and signing data. Please use the ' .
+                '\'debug\' option when creating the Crypt_GPG object, and ' .
+                'file a bug report at ' . self::BUG_URI, $code);
+        }
+
+        if ($outputFile === null) {
+            return $output;
+        }
+    }
+
+    // }}}
+    // {{{ _verify()
+
+    /**
+     * Verifies data
+     *
+     * @param string  $data      the signed data to be verified.
+     * @param boolean $isFile    whether or not the data is a filename.
+     * @param string  $signature if verifying a file signed using a detached
+     *                           signature, this must be the detached signature
+     *                           data. Otherwise, specify ''.
+     *
+     * @return array an array of {@link Crypt_GPG_Signature} objects for the
+     *               signed data.
+     *
+     * @throws Crypt_GPG_NoDataException if the provided data is not signed
+     *         data.
+     *
+     * @throws Crypt_GPG_FileException if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG_Signature
+     */
+    private function _verify($data, $isFile, $signature)
+    {
+        if ($signature == '') {
+            $operation = '--verify';
+            $arguments = array();
+        } else {
+            // Signed data goes in FD_MESSAGE, detached signature data goes in
+            // FD_INPUT.
+            $operation = '--verify - "-&' . Crypt_GPG_Engine::FD_MESSAGE. '"';
+            $arguments = array('--enable-special-filenames');
+        }
+
+        $handler = new Crypt_GPG_VerifyStatusHandler();
+
+        if ($isFile) {
+            $input = @fopen($data, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open input ' .
+                    'file "' . $data . '" for verifying.', 0, $data);
+            }
+        } else {
+            $input = strval($data);
+            if ($input == '') {
+                throw new Crypt_GPG_NoDataException(
+                    'No valid signature data found.', Crypt_GPG::ERROR_NO_DATA);
+            }
+        }
+
+        $this->engine->reset();
+        $this->engine->addStatusHandler(array($handler, 'handle'));
+
+        if ($signature == '') {
+            // signed or clearsigned data
+            $this->engine->setInput($input);
+        } else {
+            // detached signature
+            $this->engine->setInput($signature);
+            $this->engine->setMessage($input);
+        }
+
+        $this->engine->setOperation($operation, $arguments);
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        $code = $this->engine->getErrorCode();
+
+        switch ($code) {
+        case Crypt_GPG::ERROR_NONE:
+        case Crypt_GPG::ERROR_BAD_SIGNATURE:
+            break;
+        case Crypt_GPG::ERROR_NO_DATA:
+            throw new Crypt_GPG_NoDataException(
+                'No valid signature data found.', $code);
+        case Crypt_GPG::ERROR_KEY_NOT_FOUND:
+            throw new Crypt_GPG_KeyNotFoundException(
+                'Public key required for data verification not in keyring.',
+                $code, $this->engine->getErrorKeyId());
+        default:
+            throw new Crypt_GPG_Exception(
+                'Unknown error validating signature details. Please use the ' .
+                '\'debug\' option when creating the Crypt_GPG object, and ' .
+                'file a bug report at ' . self::BUG_URI, $code);
+        }
+
+        return $handler->getSignatures();
+    }
+
+    // }}}
+    // {{{ _decryptAndVerify()
+
+    /**
+     * Decrypts and verifies encrypted, signed data
+     *
+     * @param string  $data       the encrypted signed data to be decrypted and
+     *                            verified.
+     * @param boolean $isFile     whether or not the data is a filename.
+     * @param string  $outputFile the name of the file to which the decrypted
+     *                            data should be written. If null, the decrypted
+     *                            data is returned in the results array.
+     *
+     * @return array two element array. The array has an element 'data'
+     *               containing the decrypted data and an element
+     *               'signatures' containing an array of
+     *               {@link Crypt_GPG_Signature} objects for the signed data.
+     *               If the decrypted data is written to a file, the 'data'
+     *               element is null.
+     *
+     * @throws Crypt_GPG_KeyNotFoundException if the private key needed to
+     *         decrypt the data is not in the user's keyring or it the public
+     *         key needed for verification is not in the user's keyring.
+     *
+     * @throws Crypt_GPG_NoDataException if specified data does not contain
+     *         GPG signed, encrypted data.
+     *
+     * @throws Crypt_GPG_BadPassphraseException if a required passphrase is
+     *         incorrect or if a required passphrase is not specified. See
+     *         {@link Crypt_GPG::addDecryptKey()}.
+     *
+     * @throws Crypt_GPG_FileException if the output file is not writeable or
+     *         if the input file is not readable.
+     *
+     * @throws Crypt_GPG_Exception if an unknown or unexpected error occurs.
+     *         Use the <kbd>debug</kbd> option and file a bug report if these
+     *         exceptions occur.
+     *
+     * @see Crypt_GPG_Signature
+     */
+    private function _decryptAndVerify($data, $isFile, $outputFile)
+    {
+        if ($isFile) {
+            $input = @fopen($data, 'rb');
+            if ($input === false) {
+                throw new Crypt_GPG_FileException('Could not open input ' .
+                    'file "' . $data . '" for decrypting and verifying.', 0,
+                    $data);
+            }
+        } else {
+            $input = strval($data);
+            if ($input == '') {
+                throw new Crypt_GPG_NoDataException(
+                    'No valid encrypted signed data found.',
+                    Crypt_GPG::ERROR_NO_DATA);
+            }
+        }
+
+        if ($outputFile === null) {
+            $output = '';
+        } else {
+            $output = @fopen($outputFile, 'wb');
+            if ($output === false) {
+                if ($isFile) {
+                    fclose($input);
+                }
+                throw new Crypt_GPG_FileException('Could not open output ' .
+                    'file "' . $outputFile . '" for storing decrypted data.',
+                    0, $outputFile);
+            }
+        }
+
+        $verifyHandler = new Crypt_GPG_VerifyStatusHandler();
+
+        $decryptHandler = new Crypt_GPG_DecryptStatusHandler($this->engine,
+            $this->decryptKeys);
+
+        $this->engine->reset();
+        $this->engine->addStatusHandler(array($verifyHandler, 'handle'));
+        $this->engine->addStatusHandler(array($decryptHandler, 'handle'));
+        $this->engine->setInput($input);
+        $this->engine->setOutput($output);
+        $this->engine->setOperation('--decrypt');
+        $this->engine->run();
+
+        if ($isFile) {
+            fclose($input);
+        }
+
+        if ($outputFile !== null) {
+            fclose($output);
+        }
+
+        $return = array(
+            'data'       => null,
+            'signatures' => $verifyHandler->getSignatures()
+        );
+
+        // if there was any problem decrypting the data, the handler will
+        // deal with it here.
+        try {
+            $decryptHandler->throwException();
+        } catch (Exception $e) {
+            if ($e instanceof Crypt_GPG_KeyNotFoundException) {
+                throw new Crypt_GPG_KeyNotFoundException(
+                    'Public key required for data verification not in ',
+                    'the keyring. Either no suitable private decryption key ' .
+                    'is in the keyring or the public key required for data ' .
+                    'verification is not in the keyring. Import a suitable ' .
+                    'key before trying to decrypt and verify this data.',
+                    self::ERROR_KEY_NOT_FOUND, $this->engine->getErrorKeyId());
+            }
+
+            if ($e instanceof Crypt_GPG_NoDataException) {
+                throw new Crypt_GPG_NoDataException(
+                    'Cannot decrypt and verify data. No PGP encrypted data ' .
+                    'was found in the provided data.', self::ERROR_NO_DATA);
+            }
+
+            throw $e;
+        }
+
+        if ($outputFile === null) {
+            $return['data'] = $output;
+        }
+
+        return $return;
+    }
+
+    // }}}
+}
+
+// }}}
+
+?>