PHP解析Android APK包的XML文件[转]

2012.07.05更新: 某些系统apk文件的字符串表不是使用双字节,会导致解码越界. 修改了getStringTab()成员函数, 详细请看代码部分.

最近做的一个项目需要用PHP直接读取apk包中的信息,如:包名,入口地址,版本号等信息。这些信息都保存在apk包中的AndroidManifest.xml文件中。但是在编译apk包的过程中,所有XML文件都经过了压缩编码,直接读取xml文件内容是无法解析出需要的信息的。

Google搜索了一下没有找到这个功能的PHP实现,只有找到一个Java工具AXMLPrinter,可以还原经过压缩后的XML文件内容。于是就参考了这个Java工具的源码,按照这个压缩后的XML文件格式写了一个PHP的还原功能类。

类实现了直接读取apk包中指定的XML文件内容(使用PHP的zip功能函数直接解压apk包),无需手动解压apk获取文件。

类功能不多,所有供外部调用的方法都表明了公开,私有函数均是解码函数,不推荐直接调用。

使用例子:

<?php
require('apk_parser.php');
$p = new ApkParser();
$res = $p->open('android_app.apk');
echo $p->getXML();
?>

apk_parser.php源代码:

<?php
/******************************************************
 * Android APK File Parser
 * Author: Katana
 * Version: v0.1
 * Web: http://www.win-ing.cn
 *
 * 功能:解析安卓apk包中的压缩XML文件,还原和读取XML内容
 *
 * 依赖功能:需要PHP的ZIP包函数支持。
 ******************************************************/

class ApkParser{
//----------------------
// 公共函数,供外部调用
//----------------------
	public function open($apk_file, $xml_file='AndroidManifest.xml'){
		$zip = new ZipArchive;
		if ($zip->open($apk_file) === TRUE) {
			$xml = $zip->getFromName($xml_file);
			$zip->close();
			if ($xml){
				try {
					return $this->parseString($xml);
				}catch (Exception $e){
				}
			}
		}
		return false;
	}

	public function parseString($xml){
		$this->xml = $xml;
		$this->length = strlen($xml);

		$this->root = $this->parseBlock(self::AXML_FILE);
		return true;
	}

	public function getXML($node=NULL, $lv=-1){
		if ($lv == -1) $node = $this->root;
		if (!$node) return '';

		if ($node['type'] == self::END_TAG) $lv--;
		$xml = ($node['line'] == 0 || $node['line'] == $this->line) ? '' : "\n".str_repeat('  ', $lv);
		$xml .= $node['tag'];
		$this->line = $node['line'];
		foreach ($node['child'] as $c){
			$xml .= $this->getXML($c, $lv+1);
		}
		return $xml;
	}

	public function getPackage(){
		return $this->getAttribute('manifest', 'package');
	}

	public function getVersionName(){
		return $this->getAttribute('manifest', 'android:versionName');
	}

	public function getVersionCode(){
		return $this->getAttribute('manifest', 'android:versionCode');
	}

	public function getAppName(){
		return $this->getAttribute('manifest/application', 'android:name');
	}

	public function getMainActivity(){
		for ($id=0; true; $id++){
			$act = $this->getAttribute("manifest/application/activity[{$id}]/intent-filter/action", 'android:name');
			if (!$act) break;
			if ($act == 'android.intent.action.MAIN') return $this->getActivity($id);
		}
		return NULL;
	}

	public function getActivity($idx=0){
		$idx = intval($idx);
		return $this->getAttribute("manifest/application/activity[{$idx}]", 'android:name');
	}

	public function getAttribute($path, $name){
		$r = $this->getElement($path);
		if (is_null($r)) return NULL;

		if (isset($r['attrs'])){
			foreach ($r['attrs'] as $a){
				if ($a['ns_name'] == $name) return $this->getAttributeValue($a);
			}
		}
		return NULL;
	}

//----------------------
// 类型常量定义
//----------------------
	const AXML_FILE				= 0x00080003;
	const STRING_BLOCK			= 0x001C0001;
	const RESOURCEIDS			= 0x00080180;
	const START_NAMESPACE		= 0x00100100;
	const END_NAMESPACE			= 0x00100101;
	const START_TAG				= 0x00100102;
	const END_TAG				= 0x00100103;
	const TEXT					= 0x00100104;

    const TYPE_NULL				=0;
    const TYPE_REFERENCE		=1;
    const TYPE_ATTRIBUTE		=2;
    const TYPE_STRING			=3;
    const TYPE_FLOAT			=4;
    const TYPE_DIMENSION		=5;
    const TYPE_FRACTION			=6;
    const TYPE_INT_DEC			=16;
    const TYPE_INT_HEX			=17;
    const TYPE_INT_BOOLEAN		=18;
    const TYPE_INT_COLOR_ARGB8	=28;
    const TYPE_INT_COLOR_RGB8	=29;
    const TYPE_INT_COLOR_ARGB4	=30;
    const TYPE_INT_COLOR_RGB4	=31;

	const UNIT_MASK				= 15;
	private static $RADIX_MULTS = array(0.00390625, 3.051758E-005, 1.192093E-007, 4.656613E-010);
	private static $DIMENSION_UNITS = array("px","dip","sp","pt","in","mm","","");
	private static $FRACTION_UNITS  = array("%","%p","","","","","","");

	private $xml='';
	private $length = 0;
	private $stringCount = 0;
	private $styleCount  = 0;
	private $stringTab = array();
	private $styleTab  = array();
	private $resourceIDs = array();
	private $ns = array();
	private $cur_ns = NULL;
	private $root = NULL;
	private $line = 0;

//----------------------
// 内部私有函数
//----------------------
	private function getElement($path){
		if (!$this->root) return NULL;
		$ps = explode('/', $path);
		$r  = $this->root;
		foreach ($ps as $v){
			if (preg_match('/([^\[]+)\[([0-9]+)\]$/', $v, $ms)){
				$v = $ms[1];
				$off = $ms[2];
			}else {
				$off = 0;
			}
			foreach ($r['child'] as $c){
				if ($c['type'] == self::START_TAG && $c['ns_name'] == $v){
					if ($off == 0){
						$r = $c; continue 2;
					}else {
						$off--;
					}
				}
			}
			// 没有找到节点
			return NULL;
		}
		return $r;
	}

	private function parseBlock($need = 0){
		$o = 0;
		$type = $this->get32($o);
		if ($need && $type != $need) throw new Exception('Block Type Error', 1);
		$size = $this->get32($o);
		if ($size < 8 || $size > $this->length) throw new Exception('Block Size Error', 2);
		$left = $this->length - $size;

		$props = false;
		switch ($type){
			case self::AXML_FILE:
				$props = array(
					'line' => 0,
					'tag' => '<?xml version="1.0" encoding="utf-8"?>'
				);
			break;
			case self::STRING_BLOCK:
				$this->stringCount = $this->get32($o);
				$this->styleCount  = $this->get32($o);
				$o += 4;
				$strOffset = $this->get32($o);
				$styOffset = $this->get32($o);
				$strListOffset = $this->get32array($o, $this->stringCount);
				$styListOffset = $this->get32array($o, $this->styleCount);
				$this->stringTab = $this->stringCount > 0 ? $this->getStringTab($strOffset, $strListOffset) : array();
				$this->styleTab  = $this->styleCount > 0 ? $this->getStringTab($styOffset, $styListOffset) : array();
				$o = $size;
			break;
			case self::RESOURCEIDS:
				$count = $size / 4 - 2;
				$this->resourceIDs = $this->get32array($o, $count);
			break;
			case self::START_NAMESPACE:
				$o += 8;
				$prefix = $this->get32($o);
				$uri = $this->get32($o);

				if (empty($this->cur_ns)){
					$this->cur_ns = array();
					$this->ns[] = &$this->cur_ns;
				}
				$this->cur_ns[$uri] = $prefix;
			break;
			case self::END_NAMESPACE:
				$o += 8;
				$prefix = $this->get32($o);
				$uri = $this->get32($o);

				if (empty($this->cur_ns)) break;
				unset($this->cur_ns[$uri]);
			break;
			case self::START_TAG:
				$line = $this->get32($o);

				$o += 4;
				$attrs = array();
				$props = array(
					'line' => $line,
					'ns' => $this->getNameSpace($this->get32($o)),
					'name' => $this->getString($this->get32($o)),
					'flag' => $this->get32($o),
					'count' => $this->get16($o),
					'id' => $this->get16($o)-1,
					'class' => $this->get16($o)-1,
					'style' => $this->get16($o)-1,
					'attrs' => &$attrs
				);
				$props['ns_name'] = $props['ns'].$props['name'];
				for ($i=0; $i < $props['count']; $i++){
					$a = array(
						'ns' => $this->getNameSpace($this->get32($o)),
						'name' => $this->getString($this->get32($o)),
						'val_str' => $this->get32($o),
						'val_type' => $this->get32($o),
						'val_data' => $this->get32($o)
					);
					$a['ns_name'] = $a['ns'].$a['name'];
					$a['val_type'] >>= 24;
					$attrs[] = $a;
				}
				// 处理TAG字符串
				$tag = "<{$props['ns_name']}";
				foreach ($this->cur_ns as $uri => $prefix){
					$uri = $this->getString($uri);
					$prefix = $this->getString($prefix);
					$tag .= " xmlns:{$prefix}=\"{$uri}\"";
				}
				foreach ($props['attrs'] as $a){
					$tag .= " {$a['ns_name']}=\"".
							$this->getAttributeValue($a).
							'"';
				}
				$tag .= '>';
				$props['tag'] = $tag;

				unset($this->cur_ns);
				$this->cur_ns = array();
				$this->ns[] = &$this->cur_ns;
				$left = -1;
			break;
			case self::END_TAG:
				$line = $this->get32($o);
				$o += 4;
				$props = array(
					'line' => $line,
					'ns' => $this->getNameSpace($this->get32($o)),
					'name' => $this->getString($this->get32($o))
				);
				$props['ns_name'] = $props['ns'].$props['name'];
				$props['tag'] = "</{$props['ns_name']}>";
				if (count($this->ns) > 1){
					array_pop($this->ns);
					unset($this->cur_ns);
					$this->cur_ns = array_pop($this->ns);
					$this->ns[] = &$this->cur_ns;
				}
			break;
			case self::TEXT:
				$o += 8;
				$props = array(
					'tag' => $this->getString($this->get32($o))
				);
				$o += 8;
			break;
			default:
				throw new Exception('Block Type Error', 3);
			break;
		}

		$this->skip($o);
		$child = array();
		while ($this->length > $left){
			$c = $this->parseBlock();
			if ($props && $c) $child[] = $c;
			if ($left == -1 && $c['type'] == self::END_TAG){
				$left = $this->length;
				break;
			}
		}
		if ($this->length != $left) throw new Exception('Block Overflow Error', 4);
		if ($props){
			$props['type'] = $type;
			$props['size'] = $size;
			$props['child'] = $child;
			return $props;
		}else {
			return false;
		}
	}

	private function getAttributeValue($a){
		$type = &$a['val_type'];
		$data = &$a['val_data'];
		switch ($type){
			case self::TYPE_STRING:
				return $this->getString($a['val_str']);
			case self::TYPE_ATTRIBUTE:
				return sprintf('?%s%08X', self::_getPackage($data), $data);
			case self::TYPE_REFERENCE:
				return sprintf('@%s%08X', self::_getPackage($data), $data);
			case self::TYPE_INT_HEX:
				return sprintf('0x%08X', $data);
			case self::TYPE_INT_BOOLEAN:
				return ($data != 0 ? 'true' : 'false');
			case self::TYPE_INT_COLOR_ARGB8:
			case self::TYPE_INT_COLOR_RGB8:
			case self::TYPE_INT_COLOR_ARGB4:
			case self::TYPE_INT_COLOR_RGB4:
				return sprintf('#%08X', $data);
			case self::TYPE_DIMENSION:
				return $this->_complexToFloat($data).self::$DIMENSION_UNITS[$data & self::UNIT_MASK];
			case self::TYPE_FRACTION:
				return $this->_complexToFloat($data).self::$FRACTION_UNITS[$data & self::UNIT_MASK];
			case self::TYPE_FLOAT:
				return $this->_int2float($data);
		}
		if ($type >=self::TYPE_INT_DEC && $type < self::TYPE_INT_COLOR_ARGB8){
			return (string)$data;
		}
		return sprintf('<0x%X, type 0x%02X>', $data, $type);
	}

	private function _complexToFloat($data){
		return (float)($data & 0xFFFFFF00) * self::$RADIX_MULTS[($data>>4) & 3];
	}
	private function _int2float($v) {
		$x = ($v & ((1 << 23) - 1)) + (1 << 23) * ($v >> 31 | 1);
		$exp = ($v >> 23 & 0xFF) - 127;
		return $x * pow(2, $exp - 23);
	}
	private static function _getPackage($data){
		return ($data >> 24 == 1) ? 'android:' : '';
	}

	private function getStringTab($base, $list){
		$tab = array();
		foreach ($list as $off){
			$off += $base;
			$len = $this->get16($off);
			$mask = ($len >> 0x8) & 0xFF;
			$len = $len & 0xFF;
			if ($len == $mask){
				if ($off + $len > $this->length) throw new Exception('String Table Overflow', 11);
				$tab[] = substr($this->xml, $off, $len);
			}else {
				if ($off + $len * 2 > $this->length) throw new Exception('String Table Overflow', 11);
				$str = substr($this->xml, $off, $len * 2);
				$tab[] = mb_convert_encoding($str, 'UTF-8', 'UCS-2LE');
			}
		}
		return $tab;
	}
	private function getString($id){
		if ($id > -1 && $id < $this->stringCount){
			return $this->stringTab[$id];
		}else {
			return '';
		}
	}
	private function getNameSpace($uri){
		for ($i=count($this->ns); $i > 0; ){
			$ns = $this->ns[--$i];
			if (isset($ns[$uri])){
				$ns = $this->getString($ns[$uri]);
				if (!empty($ns)) $ns .= ':';
				return $ns;
			}
		}
		return '';
	}
	private function get32(&$off){
		$int = unpack('V', substr($this->xml, $off, 4));
		$off += 4;
		return array_shift($int);
	}
	private function get32array(&$off, $size){
		if ($size <= 0) return NULL;
		$arr = unpack('V*', substr($this->xml, $off, 4 * $size));
		if (count($arr) != $size) throw new Exception('Array Size Error', 10);
		$off += 4 * $size;
		return $arr;
	}
	private function get16(&$off){
		$int = unpack('v', substr($this->xml, $off, 2));
		$off += 2;
		return array_shift($int);
	}
	private function skip($size){
		$this->xml = substr($this->xml, $size);
		$this->length -= $size;
	}
}
?>

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