GnuPG（隐私保护）

GnuPG，简称 GPG，来自 http://www.gnupg.org，是 GPG 标准的一个免费实现。不管是 Linux 还是 Windows 平台，都可以使用。GPGneng 可以为文件生成签名、管理密匙以及验证签名。

此 PECL 扩展未与 PHP 捆绑。

Here are instructions for how to resolve the issue where you encounter this error:
/usr/include/gpgme.h:80:2: error: #error GPGME was compiled with _FILE_OFFSET_BITS = 64, please see the section "Largefile support (LFS)" in the GPGME manual.
This is a result of the gnupg extension currently lacking largefile support. The solution is fairly simple.
pecl download gnupg
tar -zxf gnupg-1.3.2.tgz
cd gnupg-1.3.2
Open the file config.m4 in an editor, and add "AC_SYS_LARGEFILE" to a new line at the very end of the file, then save.
phpize
./configure
make
make install
Now simply add extension=gnupg.so to your php.ini, and the extension should work.

I tried followings on Debian Squeeze and it worked fine
apt-get install libgpgme11-dev
pecl install gnupg
create a new file under conf.d folder and add following lines
; configuration for gnupg module
extension=gnupg.so
Reload apache configuration
/etc/init.d/apache2 reload
Check PHP Info and you should see gnupg
Hope this helps.

Example #1 gnupg clearsign example (procedural)

<?php
// init gnupg
$res = gnupg_init();
// not really needed. Clearsign is default
gnupg_setsignmode($res,GNUPG_SIG_MODE_CLEAR);
// add key with passphrase 'test' for signing
gnupg_addsignkey($res,"8660281B6051D071D94B5B230549F9DC851566DC","test");
// sign
$signed = gnupg_sign($res,"just a test");
echo $signed;
?>

Example #2 gnupg clearsign example (OO)

<?php
// new class
$gnupg = new gnupg();
// not really needed. Clearsign is default
$gnupg->setsignmode(gnupg::SIG_MODE_CLEAR);
// add key with passphrase 'test' for signing
$gnupg->addsignkey("8660281B6051D071D94B5B230549F9DC851566DC","test");
// sign
$signed = $gnupg->sign("just a test");
echo $signed;
?>

Example #3 keylistiterator

This extension also comes with an Iterator for your keyring.

<?php
// create a new iterator for listing all public keys that matches 'example'
$iterator = new gnupg_keylistiterator("example");
foreach($iterator as $fingerprint => $userid){
    echo $fingerprint." -> ".$userid."\n";
}
?>