Crypt/GPG.php
protected function _decrypt($data, $isFile, $outputFile)
    {
        $input  = $this->_prepareInput($data, $isFile, false);
        $output = $this->_prepareOutput($outputFile, $input);

        $this->engine->reset();
        $this->engine->setPins($this->decryptKeys);
        $this->engine->setOperation('--decrypt --skip-verify');
        $this->engine->setInput($input);
        $this->engine->setOutput($output);
        $this->engine->run();

        if ($outputFile === null) {
            return $output;
        }
    }
protected function _decrypt($data, $isFile, $outputFile)
    {
        $input  = $this->_prepareInput($data, $isFile, false);
        $output = $this->_prepareOutput($outputFile, $input);

        $this->engine->reset();
        $this->engine->setPins($this->decryptKeys);
        $this->engine->setOperation('--decrypt --skip-verify');
        $this->engine->setInput($input);
        $this->engine->setOutput($output);
        $this->engine->run();

        if ($outputFile === null) {
            return $output;
        }
    }
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.