<?php
// ASN.1 parsing library
// Attribution: http://www.krisbailey.com
// license: unknown
// modified: Mike Macgrivin mike@macgirvin.com 6-oct-2010 to support Salmon auto-discovery
// from openssl public keys
class ASN_BASE {
public $asnData = null;
private $cursor = 0;
private $parent = null;
public static $ASN_MARKERS = array(
'ASN_UNIVERSAL' => 0x00,
'ASN_APPLICATION' => 0x40,
'ASN_CONTEXT' => 0x80,
'ASN_PRIVATE' => 0xC0,
'ASN_PRIMITIVE' => 0x00,
'ASN_CONSTRUCTOR' => 0x20,
'ASN_LONG_LEN' => 0x80,
'ASN_EXTENSION_ID' => 0x1F,
'ASN_BIT' => 0x80,
);
public static $ASN_TYPES = array(
1 => 'ASN_BOOLEAN',
2 => 'ASN_INTEGER',
3 => 'ASN_BIT_STR',
4 => 'ASN_OCTET_STR',
5 => 'ASN_NULL',
6 => 'ASN_OBJECT_ID',
9 => 'ASN_REAL',
10 => 'ASN_ENUMERATED',
13 => 'ASN_RELATIVE_OID',
48 => 'ASN_SEQUENCE',
49 => 'ASN_SET',
19 => 'ASN_PRINT_STR',
22 => 'ASN_IA5_STR',
23 => 'ASN_UTC_TIME',
24 => 'ASN_GENERAL_TIME',
);
function __construct($v = false)
{
if (false !== $v) {
$this->asnData = $v;
if (is_array($this->asnData)) {
foreach ($this->asnData as $key => $value) {
if (is_object($value)) {
$this->asnData[$key]->setParent($this);
}
}
} else {
if (is_object($this->asnData)) {
$this->asnData->setParent($this);
}
}
}
}
public function setParent($parent)
{
if (false !== $parent) {
$this->parent = $parent;
}
}
/**
* This function will take the markers and types arrays and
* dynamically generate classes that extend this class for each one,
* and also define constants for them.
*/
public static function generateSubclasses()
{
define('ASN_BASE', 0);
foreach (self::$ASN_MARKERS as $name => $bit)
self::makeSubclass($name, $bit);
foreach (self::$ASN_TYPES as $bit => $name)
self::makeSubclass($name, $bit);
}
/**
* Helper function for generateSubclasses()
*/
public static function makeSubclass($name, $bit)
{
define($name, $bit);
eval("class ".$name." extends ASN_BASE {}");
}
/**
* This function reset's the internal cursor used for value iteration.
*/
public function reset()
{
$this->cursor = 0;
}
/**
* This function catches calls to get the value for the type, typeName, value, values, and data
* from the object. For type calls we just return the class name or the value of the constant that
* is named the same as the class.
*/
public function __get($name)
{
if ('type' == $name) {
// int flag of the data type
return constant(get_class($this));
} elseif ('typeName' == $name) {
// name of the data type
return get_class($this);
} elseif ('value' == $name) {
// will always return one value and can be iterated over with:
// while ($v = $obj->value) { ...
// because $this->asnData["invalid key"] will return false
return is_array($this->asnData) ? $this->asnData[$this->cursor++] : $this->asnData;
} elseif ('values' == $name) {
// will always return an array
return is_array($this->asnData) ? $this->asnData : array($this->asnData);
} elseif ('data' == $name) {
// will always return the raw data
return $this->asnData;
}
}
/**
* Parse an ASN.1 binary string.
*
* This function takes a binary ASN.1 string and parses it into it's respective
* pieces and returns it. It can optionally stop at any depth.
*
* @param string $string The binary ASN.1 String
* @param int $level The current parsing depth level
* @param int $maxLevel The max parsing depth level
* @return ASN_BASE The array representation of the ASN.1 data contained in $string
*/
public static function parseASNString($string=false, $level=1, $maxLevels=false){
if (!class_exists('ASN_UNIVERSAL'))
self::generateSubclasses();
if ($level>$maxLevels && $maxLevels)
return array(new ASN_BASE($string));
$parsed = array();
$endLength = strlen($string);
$bigLength = $length = $type = $dtype = $p = 0;
while ($p<$endLength){
$type = ord($string[$p++]);
$dtype = ($type & 192) >> 6;
if ($type==0){ // if we are type 0, just continue
} else {
$length = ord($string[$p++]);
if (($length & ASN_LONG_LEN)==ASN_LONG_LEN){
$tempLength = 0;
for ($x=0; $x<($length & (ASN_LONG_LEN-1)); $x++){
$tempLength = ord($string[$p++]) + ($tempLength * 256);
}
$length = $tempLength;
}
$data = substr($string, $p, intval($length));
$parsed[] = self::parseASNData($type, $data, $level, $maxLevels);
$p = $p + $length;
}
}
return $parsed;
}
/**
* Parse an ASN.1 field value.
*
* This function takes a binary ASN.1 value and parses it according to it's specified type
*
* @param int $type The type of data being provided
* @param string $data The raw binary data string
* @param int $level The current parsing depth
* @param int $maxLevels The max parsing depth
* @return mixed The data that was parsed from the raw binary data string
*/
public static function parseASNData($type, $data, $level, $maxLevels){
$type = $type%50; // strip out context
switch ($type){
default:
return new ASN_BASE($data);
case ASN_BOOLEAN:
return new ASN_BOOLEAN((bool)$data);
case ASN_INTEGER:
return new ASN_INTEGER(strtr(base64_encode($data),'+/','-_'));
case ASN_BIT_STR:
return new ASN_BIT_STR(self::parseASNString($data, $level+1, $maxLevels));
case ASN_OCTET_STR:
return new ASN_OCTET_STR($data);
case ASN_NULL:
return new ASN_NULL(null);
case ASN_REAL:
return new ASN_REAL($data);
case ASN_ENUMERATED:
return new ASN_ENUMERATED(self::parseASNString($data, $level+1, $maxLevels));
case ASN_RELATIVE_OID: // I don't really know how this works and don't have an example :-)
// so, lets just return it ...
return new ASN_RELATIVE_OID($data);
case ASN_SEQUENCE:
return new ASN_SEQUENCE(self::parseASNString($data, $level+1, $maxLevels));
case ASN_SET:
return new ASN_SET(self::parseASNString($data, $level+1, $maxLevels));
case ASN_PRINT_STR:
return new ASN_PRINT_STR($data);
case ASN_IA5_STR:
return new ASN_IA5_STR($data);
case ASN_UTC_TIME:
return new ASN_UTC_TIME($data);
case ASN_GENERAL_TIME:
return new ASN_GENERAL_TIME($data);
case ASN_OBJECT_ID:
return new ASN_OBJECT_ID(self::parseOID($data));
}
}
/**
* Parse an ASN.1 OID value.
*
* This takes the raw binary string that represents an OID value and parses it into its
* dot notation form. example - 1.2.840.113549.1.1.5
* look up OID's here: http://www.oid-info.com/
* (the multi-byte OID section can be done in a more efficient way, I will fix it later)
*
* @param string $data The raw binary data string
* @return string The OID contained in $data
*/
public static function parseOID($string){
$ret = floor(ord($string[0])/40).".";
$ret .= (ord($string[0]) % 40);
$build = array();
$cs = 0;
for ($i=1; $i<strlen($string); $i++){
$v = ord($string[$i]);
if ($v>127){
$build[] = ord($string[$i])-ASN_BIT;
} elseif ($build){
// do the build here for multibyte values
$build[] = ord($string[$i])-ASN_BIT;
// you know, it seems there should be a better way to do this...
$build = array_reverse($build);
$num = 0;
for ($x=0; $x<count($build); $x++){
$mult = $x==0?1:pow(256, $x);
if ($x+1==count($build)){
$value = ((($build[$x] & (ASN_BIT-1)) >> $x)) * $mult;
} else {
$value = ((($build[$x] & (ASN_BIT-1)) >> $x) ^ ($build[$x+1] << (7 - $x) & 255)) * $mult;
}
$num += $value;
}
$ret .= ".".$num;
$build = array(); // start over
} else {
$ret .= ".".$v;
$build = array();
}
}
return $ret;
}
public static function printASN($x, $indent=''){
if (is_object($x)) {
echo $indent.$x->typeName."\n";
if (ASN_NULL == $x->type) return;
if (is_array($x->data)) {
while ($d = $x->value) {
echo self::printASN($d, $indent.'. ');
}
$x->reset();
} else {
echo self::printASN($x->data, $indent.'. ');
}
} elseif (is_array($x)) {
foreach ($x as $d) {
echo self::printASN($d, $indent);
}
} else {
if (preg_match('/[^[:print:]]/', $x)) // if we have non-printable characters that would
$x = base64_encode($x); // mess up the console, then print the base64 of them...
echo $indent.$x."\n";
}
}
}
