openpgp-php/lib/OpenPGP.php
2020-06-17 22:44:51 +10:00

133 lines
3.0 KiB
PHP

<?php
// This is free and unencumbered software released into the public domain.
/**
* OpenPGP.php is a pure-PHP implementation of the OpenPGP Message Format
* (RFC 4880).
*
* @package OpenPGP
* @author Arto Bendiken <arto.bendiken@gmail.com>
* @author Stephen Paul Weber <singpolyma@singpolyma.net>
* @author Deon George <deon@leenooks.net>
* @see http://github.com/bendiken/openpgp-php
*/
namespace Leenooks;
use Leenooks\OpenPGP\Exceptions\PacketTagException;
/**
* @see http://tools.ietf.org/html/rfc4880
*/
class OpenPGP
{
const VERSION = [0,5,0];
/**
* @see http://tools.ietf.org/html/rfc4880#section-6
* @see http://tools.ietf.org/html/rfc4880#section-6.2
* @see http://tools.ietf.org/html/rfc2045
*/
static function enarmor($data,$marker='MESSAGE',array $headers=[])
{
$text = self::header($marker)."\n";
foreach ($headers as $key => $value) {
$text .= $key.': '.(string)$value."\n";
}
$text .= "\n".wordwrap(base64_encode($data),76,"\n",true);
$text .= "\n".'='.base64_encode(substr(pack('N',self::crc24($data)),1))."\n";
$text .= self::footer($marker)."\n";
return $text;
}
/**
* @see http://tools.ietf.org/html/rfc4880#section-6
* @see http://tools.ietf.org/html/rfc2045
*/
static function unarmor($text,$header='PGP PUBLIC KEY BLOCK')
{
$header = self::header($header);
$text = str_replace(["\r\n","\r"],["\n",''],$text);
if (($pos1=strpos($text,$header)) !== FALSE
&& ($pos1=strpos($text,"\n\n",$pos1+=strlen($header))) !== FALSE
&& ($pos2=strpos($text,"\n=",$pos1+=2)) !== FALSE)
{
return base64_decode($text=substr($text,$pos1,$pos2-$pos1));
}
}
/**
* @see http://tools.ietf.org/html/rfc4880#section-6.2
*/
static protected function header($marker): string
{
return '-----BEGIN '.strtoupper((string)$marker).'-----';
}
/**
* @see http://tools.ietf.org/html/rfc4880#section-6.2
*/
static protected function footer($marker): string
{
return'-----END '.strtoupper((string)$marker).'-----';
}
/**
* @see http://tools.ietf.org/html/rfc4880#section-6
* @see http://tools.ietf.org/html/rfc4880#section-6.1
*/
static function crc24($data): int
{
$crc = 0x00b704ce;
for ($i = 0; $i < strlen($data); $i++) {
$crc ^= (ord($data[$i]) & 255) << 16;
for ($j = 0; $j < 8; $j++) {
$crc <<= 1;
if ($crc & 0x01000000) {
$crc ^= 0x01864cfb;
}
}
}
return $crc & 0x00ffffff;
}
/**
* @see http://tools.ietf.org/html/rfc4880#section-12.2
*/
static function bitlength($data)
{
return (strlen($data) - 1) * 8 + (int)floor(log(ord($data[0]), 2)) + 1;
}
static function decode_s2k_count($c)
{
return ((int)16 + ($c & 15)) << (($c >> 4) + 6);
}
static function encode_s2k_count($iterations)
{
if($iterations >= 65011712) return 255;
$count = $iterations >> 6;
$c = 0;
while($count >= 32) {
$count = $count >> 1;
$c++;
}
$result = ($c << 4) | ($count - 16);
if (OpenPGP::decode_s2k_count($result) < $iterations) {
return $result + 1;
}
return $result;
}
}