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pdfex-lib.php
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pdfex-lib.php
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<?PHP
/*
* v3.0 Jun 1 2016
* pdfex-lib.php: tyLabs.com PDFExaminer - PDF processing library
* This file contains the primary library for PDF analysis and is updated often.
*/
ini_set('pcre.backtrack_limit', 10000000);
ini_set('pcre.recursion_limit', 10000000);
ini_set('memory_limit', '256M');
set_time_limit(-1);
$global_test = 0; //debug mode
if (!function_exists('hex2bin')) {
function hex2bin($h) {
if (!is_string($h))
return null;
$r='';
$len = strlen($h);
for ($a=0; $a<$len; $a+=2) {
if ($a+1 < $len)
$r.=chr(hexdec($h[$a].$h[($a+1)]));
}
return $r;
}
}
include_once('pdfex-sig.php');
/*
if (!isset($argv[1])) {
echo "Specify a file or directory.\n";
exit(0);
}
//accept a file as input
if (is_file($argv[1])) {
$result = pdfSlice(file_get_contents($argv[1]));
print_r($result);
}
function logdebug($string) {
echo $string."\n";
}
function logverbose($string) {
//echo $string."\n";
}
*/
$encodingMethods = array('PA' => 'PDF ASCIIHexDecode', 'PL' => 'PDF LZWDecode', 'P8' => 'PDF ASCII85Decode',
'PR' => 'PDF RunLengthDecode', 'PF' => 'PDF FlateDecode', 'pf' => 'PDF FlateDecode2', 'OC' => '',
'ES' => 'JavaScript Escaped', 'JA' => 'JavaScript Ascii codes', 'UC' => 'Unicode',
'RH' => 'JavaScript Hex codes', 'CF' => 'JavaScript fromCharCode', 'OC' => 'PDF Octal codes',
'oc' => 'PDF Octal codes2', 'pa' => 'PDF ASCIIHexDecode2', 'JB' => 'JavaScript in Annotation Block',
'JR' => 'JavaScript in Block', 'CR' => 'PDF Standard Encryption', 'DC' => 'PDF DCTDecode');
function pdfDecrypt($message, $key, $vector) {
return mcrypt_decrypt(
MCRYPT_RIJNDAEL_128,
$key,
$message,
MCRYPT_MODE_CBC,
$vector
);
}
function pdfDecryptRC4($message, $key, $ishex = 0) {
return rc4($key, $message, $ishex);
}
function rc4 ($pwd, $data, $ispwdHex = 0)
{
if ($ispwdHex)
$pwd = @pack('H*', $pwd); // valid input, please!
$key[] = '';
$box[] = '';
$cipher = '';
$pwd_length = strlen($pwd);
$data_length = strlen($data);
for ($i = 0; $i < 256; $i++)
{
$key[$i] = ord($pwd[$i % $pwd_length]);
$box[$i] = $i;
}
for ($j = $i = 0; $i < 256; $i++)
{
$j = ($j + $box[$i] + $key[$i]) % 256;
$tmp = $box[$i];
$box[$i] = $box[$j];
$box[$j] = $tmp;
}
for ($a = $j = $i = 0; $i < $data_length; $i++)
{
$a = ($a + 1) % 256;
$j = ($j + $box[$a]) % 256;
$tmp = $box[$a];
$box[$a] = $box[$j];
$box[$j] = $tmp;
$k = $box[(($box[$a] + $box[$j]) % 256)];
$cipher .= chr(ord($data[$i]) ^ $k);
}
return $cipher;
}
function lowOrder($data) {
$new = '';
for ($i = strlen($data)-2; $i>=0; $i-=2) {
$new .= $data[$i].$data[$i+1];
}
return $new;
}
if (!function_exists('flashExplode')) {
function flashExplode ($stream) {
$magic = substr($stream, 0, 3);
if ($magic == "CWS") {
$header = substr($stream, 4, 5);
$content = substr($stream, 10);
$uncompressed = gzinflate($content);
return "FWS".$header.$uncompressed;
} else
return $stream;
}
}
function asciihexdecode($hex)
{
$bin = '';
for ($i = 0; $i < strlen($hex)-1; $i++) {
if (ctype_alnum($hex[$i]) && ctype_alnum($hex[$i+1])) {
$n = $hex[$i].$hex[$i+1];
$bin .= chr(hexdec($n));
$i++;
} else {
//do nothing
}
}
return $bin;
}
function pdfhex($hex)
{
$str = '';
for ($i = 0; $i < strlen($hex); $i++) {
if ($i+2 <= strlen($hex) && $hex[$i] == '#' && ctype_alnum($hex[$i+1]) && ctype_alnum($hex[$i+2])) {
$n = $hex[$i+1].$hex[$i+2];
$str .= chr(hexdec($n));
$i+=2;
} else {
$str .= $hex[$i];
}
}
return $str;
}
function octal_decode($oct) {
$dec = '';
for ($i = 0; $i < strlen($oct); $i++) {
if ($oct[$i] == '\\') {
$n = '';
$i++;
for (; $i < strlen($oct); $i++) {
if (is_numeric($oct[$i]))
$n .= $oct[$i];
else {
$i--;
break;
}
}
$dec .= chr(octdec($n));
} else {
$dec .= $oct[$i];
}
}
return $dec;
}
function flatedecode($data) {
$errlev = error_reporting();
error_reporting(0);
$out = gzinflate($data);
error_reporting($errlev);
return $out;
}
function lzw_decode($data) {
$lz = new LZW();
$d = $lz->decode($data);
return $d;
}
function ascii85_decode($data) {
$output = '';
//get rid of the whitespaces
$whiteSpace = array("\x00", "\x09", "\x0A", "\x0C", "\x0D", "\x20");
$data = str_replace($whiteSpace, '', $data);
$data = substr($data, 0, (strlen($data) - 2));
$dataLength = strlen($data);
for ($i = 0; $i < $dataLength; $i += 5) {
$b = 0;
if (substr($data, $i, 1) == "z") {
$i -= 4;
$output .= pack("N", 0);
continue;
}
$c = substr($data, $i, 5);
if(strlen($c) < 5) {
//partial chunk
break;
}
$c = unpack('C5', $c);
$value = 0;
for ($j = 1; $j <= 5; $j++) {
$value += (($c[$j] - 33) * pow(85, (5 - $j)));
}
$output .= pack("N", $value);
}
//decode partial
if ($i < $dataLength) {
$value = 0;
$chunk = substr($data, $i);
$partialLength = strlen($chunk);
//pad the rest of the chunk with u's
//until the lenght of the chunk is 5
for ($j = 0; $j < (5 - $partialLength); $j++) {
$chunk .= 'u';
}
$c = unpack('C5', $chunk);
for ($j = 1; $j <= 5; $j++) {
$value += (($c[$j] - 33) * pow(85, (5 - $j)));
}
$foo = pack("N", $value);
$output .= substr($foo, 0, ($partialLength - 1));
}
return $output;
}
function runlengthdecode($data) {
$dataLength = strlen($data);
$output = '';
$i = 0;
while($i < $dataLength) {
$byteValue = ord($data[$i]);
//EOD byte
if ($byteValue == 128) {
break;
}
if ($byteValue < 128) {
$output .= substr($data, $i + 1, ($byteValue + 1));
$i += $byteValue + 2;
}
if ($byteValue > 128) {
$numOfTimesToCopy = 257 - $byteValue;
$copyValue = $data[$i + 1];
for($j = 0; $j < $numOfTimesToCopy; $j++) {
$output .= $copyValue;
}
$i += 2;
}
}
return $output;
}
if (!function_exists('strhex')) {
function strhex($string) {
$hex = '';
$len = strlen($string);
for ($i = 0; $i < $len; $i++) {
$hex .= str_pad(dechex(ord($string[$i])), 2, 0, STR_PAD_LEFT);
}
return $hex;
}
}
function decryptObj($document, $object, $key, $stream) {
if ($key != '') {
$object['key_long'] = $key.$object['decrypt_part'];
$object['key'] = md5(hex2bin($object['key_long']));
if ($document['r'] == 5) {
$t = pdfDecrypt(
substr($stream, 16),
hex2bin($key),
substr($stream, 0, 16));
//remove padding - aes
//echo "result=$t==\n";
$last = ord(substr($t, -1));
//echo "checking for padding of $last\n";
$padding = substr($t, -$last);
//echo "padding is ".strhex($padding)."\n";
$pad_fail = 0;
for($i = 0; $i < $last; $i++) {
if ($padding[$i] != chr($last)) {
$pad_fail = 1;
break;
}
}
if ($pad_fail == 0) {
//echo "trimming padding\n";
$t = substr($t, 0, (strlen($t)-$last) );
}
} else if ($document['r'] == 4) {
$t = pdfDecrypt(
substr($stream, 16),
hex2bin($object['key']),
substr($stream, 0, 16));
//remove padding - aes
$last = ord(substr($t, -1));
//echo "checking for padding of $last\n";
$padding = substr($t, -$last);
//echo "padding is ".strhex($padding)."\n";
$pad_fail = 0;
for($i = 0; $i < $last; $i++) {
if ($padding[$i] != chr($last)) {
$pad_fail = 1;
break;
}
}
if ($pad_fail == 0) {
//echo "trimming padding\n";
$t = substr($t, 0, (strlen($t)-$last) );
}
} else {
if ($document['v'] == 1){
//$object['decrypt_part'] = "0a00000000";
//$object['key_long'] = $key.$object['decrypt_part'];
//$object['key'] = md5(hex2bin($object['key_long']));
$object['key'] = substr($object['key'], 0, 20);
}
if ($document['v'] == 3) {
$object['obj_hex'] = pdfxor(pdfhex2str($object['obj_hex']), pdfhex2str('3569AC'));
$object['gen_hex'] = pdfxor(pdfhex2str($object['gen_hex']), pdfhex2str('CA96'));
//echo "tyler ".$object['obj_hex']." ".$object['gen_hex']."\n";
$object['decrypt_part'] = lowOrder($object['obj_hex']).lowOrder($object['gen_hex']);
if ($document['v'] >= 3) {
$object['decrypt_part'] .= "73416C54";
}
$object['key_long'] = $key.$object['decrypt_part'];
$object['key'] = md5(hex2bin($object['key_long']));
}
//echo $object['object']." using key ".$object['key']."\n";
$t = pdfDecryptRC4($stream,$object['key'], 1);
//echo "rc4 ".strlen($t)." ".$t."\n";
}
} else
$t = $stream;
return $t;
}
function pdfhex2str($hex)
{
$str = '';
for($i=0;$i<strlen($hex);$i+=2)
{
$str.=chr(hexdec(substr($hex,$i,2)));
}
return $str;
}
function pdfxor($InputString, $KeyPhrase){
$KeyPhraseLength = strlen($KeyPhrase);
// Loop trough input string
for ($i = 0; $i < strlen($InputString); $i++){
// Get key phrase character position
$rPos = $i % $KeyPhraseLength;
// Magic happens here:
$r = ord($InputString[$i]) ^ ord($KeyPhrase[$rPos]);
// Replace characters
$InputString[$i] = chr($r);
}
return $InputString;
}
function unliteral($oct) {
$dec = '';
for ($i = 0; $i < strlen($oct); $i++) {
if ($oct[$i] == '\\') {
if ($oct[$i+1] == 'n') {
$dec .= chr(hexdec("0a"));
$i+= 1;
} else if ($oct[$i+1] == 'r') {
$dec .= chr(hexdec("0d"));
$i+= 1;
} else if ($oct[$i+1] == 't') {
$dec .= chr(hexdec("09"));
$i+= 1;
} else if ($oct[$i+1] == 'b') {
$dec .= chr(hexdec("08"));
$i+= 1;
} else if ($oct[$i+1] == 'f') {
$dec .= chr(hexdec("0c"));
$i+= 1;
} else if ($oct[$i+1] == '(') {
$dec .= chr(hexdec("28"));
$i+= 1;
} else if ($oct[$i+1] == ')') {
$dec .= chr(hexdec("29"));
$i+= 1;
} else if ($oct[$i+1] == '\\') {
$dec .= chr(hexdec("5c"));
$i+= 1;
} else if (isset($oct[$i+3]) && preg_match('/^[0-7]$/', $oct[$i+1].$oct[$i+2].$oct[$i+3]) === true ) {
$dec .= chr(octdec($oct[$i+1].$oct[$i+2].$oct[$i+3]));
$i+= 3;
} else if (isset($oct[$i+2]) && preg_match('/^[0-7]$/', $oct[$i+1].$oct[$i+2]) === true ) {
$dec .= chr(octdec($oct[$i+1].$oct[$i+2]));
$i+= 2;
} else if (isset($oct[$i+1]) && preg_match('/^[0-7]$/', $oct[$i+1]) === true ) {
$dec .= chr(octdec($oct[$i+1]));
$i+= 1;
} else {
$dec .= $oct[$i];
}
} else {
$dec .= $oct[$i];
}
}
return $dec;
}
function pdfSlice($data) {
global $global_test, $literalEncodings, $global_userpass;
$key = '';
$master_block_encoding = '';
$block_encoding = '';
$result = array('document' => array());
$result['document']['v'] = "0";
logDebug("crypto check");
if (preg_match("/\/AuthEvent\/DocOpen\/CFM\/AESV2/si", $data) || preg_match("/\/Encrypt\s+/s", $data)) {
//find Encryption defns
if (preg_match("/\/Encrypt (\d+)\D+(\d+)\D+R/si", $data,$matches)) {
$result['document']['encrypt_obj'] = $matches[1];
$result['document']['encrypt_gen'] = $matches[2];
//echo "Looking for encryption obj ".$result['document']['encrypt_obj']." ".$result['document']['encrypt_gen']."\n";
preg_match_all("/(\x0a|\x0d|\x20)".$result['document']['encrypt_obj']."[^\d]{1,3}".$result['document']['encrypt_gen']."[^\d]{1,3}obj(.+?)endobj/si", $data, $matches0, PREG_OFFSET_CAPTURE);
//print_r($matches0);
if (isset($matches0[0])) {
$ordered = array();
for($j = 0; $j< count($matches0[0]); $j++) {
$ordered[$matches0[2][$j][1]] = array();
for($i = 1; $i< count($matches0); $i++) {
$ordered[$matches0[2][$j][1]][$i] = $matches0[$i][$j][0];
}
}
}
//print_r($ordered);
$encrypt_block = end($ordered);
$encrypt_block = $encrypt_block[2];
//print_r($encrypt_block);
}
if ( !isset($encrypt_block) ) {
preg_match("/\/Encrypt(.*?)(endobj|$)/si", $data,$matches);
if (isset($matches[1]))
$encrypt_block = $matches[1];
}
if ( !isset($encrypt_block) )
$encrypt_block = $data;
$encrypted = 1;
$result['document']['encrypted'] = 1;
$result['document']['padding'] = '28BF4E5E4E758A4164004E56FFFA01082E2E00B6D0683E802F0CA9FE6453697A'; //standard padding
$result['document']['u'] = "00000000000000000000000000000000";
if (isset ($global_userpass) && $global_userpass != '')
$result['document']['u'] = strhex($global_userpass);
$result['document']['o'] = "";
$result['document']['id'] = "";
if (preg_match_all("/\/ID[^\[]{0,5}\[\s*<(.*?)>/si", $data, $matchi)) {
//print_r($matchi);
$last = count($matchi[1])-1;
if ($last < 0) $last = 0;
$result['document']['id'] = $matchi[1][$last];
} else if (preg_match_all("/\/ID[^\[]{0,5}\[\s*\((.*?)\)/si", $data, $matchi)) {
//print_r($matchi);
$last = count($matchi[1])-1;
if ($last < 0) $last = 0;
$result['document']['id'] = strhex(unliteral($matchi[1][$last]));
}
if (preg_match("/\/O[^\(]{0,5}\((.{32,64}?)\)/si", $encrypt_block, $matcho))
$result['document']['o'] = strhex($matcho[1]);
else if (preg_match("/\/O[^\<]{0,5}\<(.{64}?)\>/si", $encrypt_block, $matcho))
$result['document']['o'] = $matcho[1];
if ($result['document']['o'] == "" && preg_match("/trailer.{1,400}\/O[^\<]{0,5}\<(.{32,64}?)\>/si", $data, $matcho))
$result['document']['o'] = $matcho[1];
$result['document']['o_orig'] = $result['document']['o'];
if (strlen($result['document']['o']) > 64) { //fix escaped things
$result['document']['o'] = strhex(unliteral(hex2str($result['document']['o'])));
//$result['document']['o'] = str_replace("5c72", "0d", $result['document']['o']);
//$result['document']['o'] = str_replace("5c5c", "[block]", $result['document']['o']);
//$result['document']['o'] = str_replace("5c", "", $result['document']['o']);
//$result['document']['o'] = str_replace("[block]", "5c", $result['document']['o']);
}
$result['document']['key_length'] = 128;
if (preg_match("/\/Length\s+(\d{1,4})\D/si",$encrypt_block, $matchl))
$result['document']['key_length'] = $matchl[1];
if ($result['document']['key_length'] <= 16)
$result['document']['key_length'] *= 8;
$result['document']['r'] = 1; //version
if (preg_match("/\/R (\d{1})\D/si",$encrypt_block, $matchr))
$result['document']['r'] = $matchr[1]; //version 1-4
$result['document']['v'] = 4; //version
if (preg_match("/\/V (\d{1})\D/si", $encrypt_block, $matchv))
$result['document']['v'] = $matchv[1]; //version 1-4
if (preg_match("/\/P ([0-9-]*)/si", $encrypt_block, $matchp))
$result['document']['p'] = $matchp[1]; //permission - 32 bit
if ($result['document']['r'] <= 2) $result['document']['key_length'] = 40;
//r=5 AESV3 (AES-256) 2011 12 15
if ($result['document']['r'] == 5) {
$result['document']['key_length'] = 256;
//StrF-EFF
//O is 48 bytes
if (preg_match("/\/O[^\(]{0,5}\((.{48,132}?)\)/si", $encrypt_block, $matcho))
$result['document']['o'] = strhex($matcho[1]);
else if (preg_match("/\/O[^\<]{0,5}\<(.{96,164}?)\>/si", $encrypt_block, $matcho))
$result['document']['o'] = $matcho[1];
if (strlen($result['document']['o']) > 96) //fix escaped things
$result['document']['o'] = strhex(unliteral(hex2str($result['document']['o'])));
if (strlen($result['document']['o']) > 96)
$result['document']['o'] = substr($result['document']['o'], 0, 96);
if (preg_match("/\/U[\s]{0,5}\((.{48,132}?)\)/si", $encrypt_block, $matcho))
$result['document']['u'] = strhex($matcho[1]);
else if (preg_match("/\/U[\s]{0,5}\<(.{96,164}?)\>/si", $encrypt_block, $matcho))
$result['document']['u'] = $matcho[1];
if (strlen($result['document']['u']) > 96) //fix escaped things
$result['document']['u'] = strhex(unliteral(hex2str($result['document']['u'])));
if (strlen($result['document']['u']) > 96)
$result['document']['u'] = substr($result['document']['u'], 0, 96);
$result['document']['oe'] = "";
$result['document']['ue'] = "";
$result['document']['perms'] = "";
if (preg_match("/\/OE[^\(]{0,5}\((.{32,64}?)\)/si", $encrypt_block, $matcho))
$result['document']['oe'] = strhex($matcho[1]);
else if (preg_match("/\/OE[^\<]{0,5}\<(.{64}?)\>/si", $encrypt_block, $matcho))
$result['document']['oe'] = $matcho[1];
if (strlen($result['document']['oe']) > 64) //fix escaped things
$result['document']['oe'] = strhex(unliteral(hex2str($result['document']['oe'])));
if (preg_match("/\/UE[^\(]{0,5}\((.{32,64}?)\)/si", $encrypt_block, $matcho))
$result['document']['ue'] = strhex($matcho[1]);
else if (preg_match("/\/UE[^\<]{0,5}\<(.{64}?)\>/si", $encrypt_block, $matcho))
$result['document']['ue'] = $matcho[1];
if (strlen($result['document']['ue']) > 64) //fix escaped things
$result['document']['ue'] = strhex(unliteral(hex2str($result['document']['ue'])));
if (preg_match("/\/Perms[^\(]{0,5}\((.{16,32}?)\)/si", $encrypt_block, $matcho))
$result['document']['perms'] = strhex($matcho[1]);
else if (preg_match("/\/Perms[^\<]{0,5}\<(.{32}?)\>/si", $encrypt_block, $matcho))
$result['document']['perms'] = $matcho[1];
if (strlen($result['document']['perms']) > 32) //fix escaped things
$result['document']['perms'] = strhex(unliteral(hex2str($result['document']['perms'])));
//Algorithm 3.2a proposed ISO 32000-2
/*To understand the algorithm below, it is necessary to treat the O and U strings in the Encrypt dictionary as made up of three sections. The first 32 bytes are a hash value (explained below). The next 8 bytes are called the Validation Salt. The final 8 bytes are called the Key Salt.*/
$result['document']['password'] = '';
/*Compute an intermediate user key by computing the SHA-256 hash of the UTF-8 password concatenated with the 8 bytes of user Key Salt. The 32-byte result is the key used to decrypt the 32-byte UE string using AES-256 in CBC mode with no padding and an initialization vector of zero. The 32-byte result is the file encryption key.*/
//echo "UE: ".$result['document']['ue']."\n";
//echo "user key salt:".substr($result['document']['u'], 80, 16)."\n";
$result['document']['ue_key']= hash('sha256', hex2bin($result['document']['password'].substr($result['document']['u'], 80, 16)));
$result['document']['key'] = strhex(mcrypt_decrypt(MCRYPT_RIJNDAEL_128,hex2bin($result['document']['ue_key']), hex2bin($result['document']['ue']), MCRYPT_MODE_CBC), ''); //AES256
//echo "ukey: ".$result['document']['key']."\n";
/*
Decrypt the 16-byte Perms string using AES-256 in ECB mode with an initialization vector of zero and the file encryption key as the key. Verify that bytes 9-11 of the result are the characters 'a', 'd', 'b'. Bytes 0-3 of the decrypted Perms entry, treated as a little-endian integer, are the user permissions. They should match the value in the P key.*/
//echo "check perms: ".$result['document']['perms']."\n";
$result['document']['test2'] = strhex(mcrypt_decrypt(MCRYPT_RIJNDAEL_128, hex2bin($result['document']['key']), hex2bin(substr($result['document']['perms'], 0, 32)), MCRYPT_MODE_ECB, ''));
if (substr(hex2bin($result['document']['test2']), 9,3) == "abd")
$result['document']['aesv3'] = 1;
else
$result['document']['aesv3'] = 0;
$key = $result['document']['key'];
} else {
//Algorithm 3.2
//ISO 32000-1 2008 7.6.3.3 Encryption Key Algorithm 2, step a:
$trimmed = rtrim($result['document']['u'], "0");
//echo "trimmed ".strlen($trimmed)."\n";
if (strlen($trimmed) % 2 == 1)
$trimmed .= "0";
//echo "trimmed ".strlen($trimmed)."\n";
$result['document']['password'] = str_pad($trimmed, 64, $result['document']['padding'], STR_PAD_RIGHT);
//checks
//echo "O check ".strlen($result['document']['o'])."\n";
//echo "u check ".strlen($result['document']['u'])."\n";
//echo "p check ".strlen($result['document']['password'])."\n";
//step b
//echo "step b ".$result['document']['password']."\n";
$hashbuilder = $result['document']['password'];
//step c
$hashbuilder .= $result['document']['o'];
//echo "step c ".$result['document']['o']."\n";
//step d Convert the integer value of the P entry to a 32-bit unsigned binary number
//and pass these bytes to the MD5 hash function, low-order byte first
if ($result['document']['p'] < 0)
$permissions = pow(2, 32) + ($result['document']['p']);
else
$permissions = $result['document']['p'];
$result['document']['p_hexh'] = str_pad(dechex( pow(2, 32)- pow(2, 32)+$permissions), 8, 0, STR_PAD_LEFT);
$result['document']['p_hex'] = lowOrder($result['document']['p_hexh']);
$result['document']['p_raw'] = $permissions;
$result['document']['p_max'] = pow(2, 32);
$result['document']['p_check'] = hexdec($result['document']['p_hexh']);
$hashbuilder .= $result['document']['p_hex'];
//echo "step c ".lowOrder(dechex($permissions))."\n";
//step e add id
//echo "step e ".$result['document']['id']."\n";
$hashbuilder .= $result['document']['id'];
//step f revision 4 or greater) If document metadata is not being encrypted,
//pass 4 bytes with the value 0xFFFFFFFF
//if ($result['document']['v'] == 4 && $result['document']['EncryptMetadata'] == 'false') {
//$hashbuilder .= 'FFFFFFFF';
//echo "step f FFFFFFFF\n";
//}
//echo "hashbuilder final [".strlen($hashbuilder)."] $hashbuilder\n";
//step g Finish the hash
$result['document']['hashbuilder'] = $hashbuilder;
$hash = md5(hex2bin($hashbuilder));
//echo "step g hash $hash\n";
//step h
if ($result['document']['r'] > 2) {
for ($i = 0; $i < 50; $i++) {
$partial = substr($hash,0,$result['document']['key_length']/4);
$hash = md5(hex2bin($partial));
//echo "step h $i md5($partial) = $hash\n";
}
}
//echo "step h final hash $hash\n";
//step i
if ($result['document']['r'] > 2)
$key = substr($hash,0,$result['document']['key_length']/4);
else
$key = substr($hash,0,10);
//echo "step i key $key\n";
$result['document']['key'] = $key;
logDebug("PDF Encrypted - general key is $key");
}
}
//$block_no = 0;
logDebug("all obj slicing");
//all objects n
unset($matches0);
//preg_match_all("/(\x0a|\x0d|\x20)(\d{1,4})[^\d]{1,3}(\d{1,2})\sobj/si", $data, $matches0, PREG_OFFSET_CAPTURE);
preg_match_all("/((\x0a|\x0d|\x20)(\d{1,4})[^\d]{1,3}(\d{1,2})\sobj|(\x0a|\x0d)(xref|trailer)(\x0a|\x0d))/si", $data, $matches0, PREG_OFFSET_CAPTURE);
//print_r($matches0);
$ordered = array();
if (isset($matches0[1])) {
for($j = 0; $j< count($matches0[0]); $j++) {
$end = '';
if (isset($matches0[0][$j+1][1]))
$end = $matches0[0][$j+1][1]+1;
else
$end = strlen($data);
$dup_id = $matches0[0][$j][1]+1;
if (isset($matches0[6][$j][0]) && ($matches0[6][$j][0] == 'xref' || $matches0[6][$j][0] == 'trailer' )) {
$start = $matches0[0][$j][1]+1;
$len = ($end-$start);
$ordered[$dup_id] = array('otype' => $matches0[6][$j][0], 'obj_id' => '0', 'gen_id' => '0', 'start' => $start,
'end' => $end, 'len' => $len, 'dup_id' => $dup_id, 'parameters' => substr($data ,$start, $len) );
//print_r($ordered[$dup_id]);
} else {
$start = $matches0[4][$j][1]+strlen($matches0[4][$j][0])+4;
$len = ($end-$start);
$ordered[$dup_id] = array('obj_id' => $matches0[3][$j][0], 'gen_id' => $matches0[4][$j][0], 'start' => $start,
'end' => $end, 'len' => $len, 'dup_id' => $dup_id, 'parameters' => substr($data ,$start, $len) );
}
//$ordered[$matches0[0][$j][1]] = array();
}
}
//print_r($ordered);
foreach ($ordered as $dup_id => $vals){
$index = $vals['obj_id'].".".$vals['gen_id'].".".$dup_id;
$result[$index] = array('object' => $vals['obj_id'], 'generation' => $vals['gen_id'],
'obj_hex' => str_pad(dechex($vals['obj_id']), 6, 0, STR_PAD_LEFT),
'gen_hex' => str_pad(dechex($vals['gen_id']), 4, 0, STR_PAD_LEFT), 'dup_id' => $dup_id,
'parameters' => $vals['parameters'], 'atype' => 'sas');
if (isset($vals['otype']))
$result[$index]['otype'] = $vals['otype'];
$result[$index]['decrypt_part'] = lowOrder($result[$index]['obj_hex']).lowOrder($result[$index]['gen_hex']);
if ($result['document']['v'] >= 3) {
$result[$index]['decrypt_part'] .= "73416C54";
}
//handle encrypted strings
if (isset($result['document']['key']) && $result['document']['key'] != '' && !isset($vals['otype']) ) {
preg_match_all("/\((.*?)\)(\x0a|\x0d)/s", $result[$index]['parameters'], $param1);
//var_dump($param1);
for($j = 0; $j< count($param1[1]); $j++) {
//echo "test=".$param1[1][$j]."=endtest\n";
$p = unliteral($param1[1][$j]);
//echo "test1=".$p."=endtest1\n";
$newParams = decryptObj($result['document'], $result[$index], $key, $p);
if ($newParams != '') {
//echo $newParams;
$result[$index]['parameters'] = $newParams."\n[encrypted params:]".$result[$index]['parameters'];
}
}
}
}
//print_r($result);
//$block_no = 0;
logDebug("no stream objects");
//all objects n
unset($matches0);
preg_match_all("/(\x0a|\x0d|\x20)(\d{1,4})[^\d]{1,3}(\d{1,2})\sobj(.*?)endobj/si", $data, $matches0, PREG_OFFSET_CAPTURE);
//logDebug("1");
if (isset($matches0[1])) {
$ordered = array();
for($j = 0; $j< count($matches0[0]); $j++) {
$ordered[$matches0[2][$j][1]] = array();
for($i = 1; $i< count($matches0); $i++) {
$ordered[$matches0[2][$j][1]][$i] = $matches0[$i][$j][0];
}
}
}
foreach ($ordered as $dup_id => $val) {
//$block_no++;
if (!isset($result[$val[2].".".$val[3].".".$dup_id])) {
//logDebug("2 - ".$val[2]);
$result[$val[2].".".$val[3].".".$dup_id] = array('object' => $val[2], 'generation' => $val[3],
'obj_hex' => str_pad(dechex($val[2]), 6, 0, STR_PAD_LEFT),
'gen_hex' => str_pad(dechex($val[3]), 4, 0, STR_PAD_LEFT), 'dup_id' => $dup_id,
'parameters' => $val[4], 'atype' => 'nos');
$result[$val[2].".".$val[3].".".$dup_id]['decrypt_part'] = lowOrder($result[$val[2].".".$val[3].".".$dup_id]['obj_hex']).lowOrder($result[$val[2].".".$val[3].".".$dup_id]['gen_hex']);
if ($result['document']['v'] >= 3) {
$result[$val[2].".".$val[3].".".$dup_id]['decrypt_part'] .= "73416C54";
}
//handle encrypted strings
if (isset($result['document']['key']) && $result['document']['key'] != '') {
preg_match_all("/\((.*?)\)(\x0a|\x0d)/s", $result[$val[2].".".$val[3].".".$dup_id]['parameters'], $param1);
//var_dump($param1);
for($j = 0; $j< count($param1[1]); $j++) {
//echo "test=".$param1[1][$j]."=endtest\n";
$p = unliteral($param1[1][$j]);
//echo "test1=".$p."=endtest1\n";
$newParams = decryptObj($result['document'], $result[$val[2].".".$val[3].".".$dup_id], $key, $p);
if ($newParams != '') {
//echo $newParams;
$result[$val[2].".".$val[3].".".$dup_id]['parameters'] = $newParams."\n[encrypted params:]".$result[$val[2].".".$val[3].".".$dup_id]['parameters'];
}
}
}
}
}
//$block_no = 0;
logDebug("scan all streams");
unset($matches0);
//all streams o
preg_match_all("/(\x0a|\x0d|\x20)(\d{1,4})[^\d]{1,3}(\d{1,2})\s+obj((?:(?! obj).){1,350}?)(s|#73)(t|#74)(r|#72)(e|#65)(a|#61)(m|#6d)(.*?)(e|#65)(n|#6e)(d|#64)(s|#73|o|#6f)/si", $data, $matches0, PREG_OFFSET_CAPTURE);
if (isset($matches0[0])) {
$ordered = array();
for($j = 0; $j< count($matches0[0]); $j++) {
$ordered[$matches0[2][$j][1]] = array();
for($i = 1; $i< count($matches0); $i++) {
$ordered[$matches0[2][$j][1]][$i] = $matches0[$i][$j][0];
}
}
}
foreach ($ordered as $dup_id => $val) {
//$block_no++;
$result[$val[2].".".$val[3].".".$dup_id] = array('object' => $val[2], 'generation' => $val[3],
'obj_hex' => str_pad(dechex($val[2]), 6, 0, STR_PAD_LEFT),
'gen_hex' => str_pad(dechex($val[3]), 4, 0, STR_PAD_LEFT), 'dup_id' => $dup_id,
'parameters' => $val[4], 'atype' => 'alls');
$result[$val[2].".".$val[3].".".$dup_id]['decrypt_part'] = lowOrder($result[$val[2].".".$val[3].".".$dup_id]['obj_hex']).lowOrder($result[$val[2].".".$val[3].".".$dup_id]['gen_hex']);
if ($result['document']['v'] >= 3) {
$result[$val[2].".".$val[3].".".$dup_id]['decrypt_part'] .= "73416C54";
}
$d = trim($val[11], "\x0A\x0D");
$result[$val[2].".".$val[3].".".$dup_id]['md5_raw'] = md5(trim($d, "\x0A\x0D"));
$result[$val[2].".".$val[3].".".$dup_id]['stream'] = trim($d, "\x0A\x0D");
$t = decryptObj($result['document'], $result[$val[2].".".$val[3].".".$dup_id], $key, $d);
$result[$val[2].".".$val[3].".".$dup_id]['md5'] = md5(trim($t, "\x0A\x0D"));
$result[$val[2].".".$val[3].".".$dup_id]['decoded'] = trim($t, "\x0A\x0D");
$result[$val[2].".".$val[3].".".$dup_id]['text'] = getPDFText($t);
//handle encrypted strings
if (isset($result['document']['key']) && $result['document']['key'] != '') {
preg_match_all("/\((.*?)\)(\x0a|\x0d)/s", $result[$val[2].".".$val[3].".".$dup_id]['parameters'], $param1);
//var_dump($param1);