Req #73432 [NEW]: openssl_error_string() returns empty for authentication error using GCM or CCM

From: enrico at zimuel dot it Operating system: Ubuntu PHP version: 7.1.0RC5 Package: OpenSSL related Bug Type: Feature/Change Request Bug description:openssl_error_string() returns empty for authentication error using GCM or CCM Description: ------------ I'm testing the new features of PHP 7.1 for the support of AEAD using OpenSSL and I noticed that the openssl_error_string() returns an empty string in case of authentication error. It will be nice to have a message here to recognize this new case. Test script: --------------- $iv = random_bytes(openssl_cipher_iv_length('aes-256-gcm')); $key = random_bytes(32); $data = random_bytes(1024); $ciphertext = openssl_encrypt($data, 'aes-256-gcm', $key, OPENSSL_RAW_DATA, $iv, $tag); // Change 1 bit in ciphertext $i = rand(0, mb_strlen($ciphertext, '8bit') - 1); $ciphertext[$i] = $ciphertext[$i] ^ chr(1); $decrypt = openssl_decrypt($ciphertext, 'aes-256-gcm', $key, OPENSSL_RAW_DATA, $iv, $tag); if (false === $decrypt) { printf("OpenSSL message: %s", openssl_error_string()); } Expected result: ---------------- OpenSSL message: authentication error Actual result: -------------- OpenSSL message: -- Edit bug report at https://bugs.php.net/bug.php?id=73432&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=73432&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=73432&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=73432&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=73432&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=73432&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=73432&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=73432&r=needscript Try newer version: https://bugs.php.net/fix.php?id=73432&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=73432&r=support Expected behavior: https://bugs.php.net/fix.php?id=73432&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=73432&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=73432&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=73432&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=73432&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=73432&r=dst IIS Stability: https://bugs.php.net/fix.php?id=73432&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=73432&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=73432&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=73432&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=73432&r=mysqlcfg