Bug #71506 [NEW]: inflate_add() does not detect corrupted compressed data

From: salsi at icosaedro dot it Operating system: Slackware 14.1 PHP version: Irrelevant Package: Zlib related Bug Type: Bug Bug description:inflate_add() does not detect corrupted compressed data Description: ------------ The inflate_add() function is available as of PHP 7.0.0 and it incrementally decompresses DEFLATE, ZLIB and GZIP compressed data passed chunk by chunk. When GZIP compressed data are feed to this function, it succeeds detecting corrupted data, but it fails to detect trunked data, as the following test script proves. Test script: --------------- <?php error_reporting(-1); // $deflateContext = deflate_init(ZLIB_ENCODING_GZIP); // $compressed = deflate_add($deflateContext, "Data to compress", ZLIB_NO_FLUSH); // $compressed .= deflate_add($deflateContext, ", more data", ZLIB_NO_FLUSH); // $compressed .= deflate_add($deflateContext, ", and even more data!", ZLIB_FINISH); // Creates GZIP compressed data: $plain = "Data to compress, more data, and even more data!"; $compressed = gzencode($plain); echo "Compressed: ", wordwrap(bin2hex($compressed), 2, " ", TRUE), "\n"; // These tests succeeded with error, as expected: // Invalid checksum: // $compressed[strlen($compressed)-5] = 'x'; // --> E_WARNING: inflate_add(): data error // Invalid length: // $compressed[strlen($compressed)-2] = 'x'; // --> E_WARNING: inflate_add(): data error // Corrupted compressed data: // $compressed[strlen($compressed)/2] = 'x'; // --> E_WARNING: inflate_add(): data error // Following test FAILED to detect corrupted data: // Trunked lenght field: // $compressed = substr($compressed, 0, strlen($compressed)-4); // --> Data to compress, more data, and even more data! // NO ERROR SIGNALED // Trunked Adler32 and lenght fields: // $compressed = substr($compressed, 0, strlen($compressed)-8); // --> Data to compress, more data, and even more data! // NO ERROR SIGNALED // Trunked some data, Adler32 and lenght fields: $compressed = substr($compressed, 0, strlen($compressed)-12); // --> Data to compress, more data, and eve // TRUNKED RESULTING DATA, NO ERROR SIGNALED echo "Corrupted : ", wordwrap(bin2hex($compressed), 2, " ", TRUE), "\n"; $inflateContext = inflate_init(ZLIB_ENCODING_GZIP); $uncompressed = inflate_add($inflateContext, $compressed, ZLIB_NO_FLUSH); $uncompressed .= inflate_add($inflateContext, NULL, ZLIB_FINISH); echo $uncompressed; ?> Expected result: ---------------- E_WARNING: inflate_add(): data error Actual result: -------------- Data to compress, more data, and eve (note how the original plain string has been trunked, but no error is detected). -- Edit bug report at https://bugs.php.net/bug.php?id=71506&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=71506&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=71506&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=71506&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=71506&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=71506&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=71506&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=71506&r=needscript Try newer version: https://bugs.php.net/fix.php?id=71506&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=71506&r=support Expected behavior: https://bugs.php.net/fix.php?id=71506&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=71506&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=71506&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=71506&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=71506&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=71506&r=dst IIS Stability: https://bugs.php.net/fix.php?id=71506&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=71506&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=71506&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=71506&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=71506&r=mysqlcfg