Req #76935 [NEW]: "chacha20-poly1305" is an AEAD but does not work like AEAD

From: patrakov at gmail dot com Operating system: Linux PHP version: 7.2.10 Package: OpenSSL related Bug Type: Feature/Change Request Bug description:"chacha20-poly1305" is an AEAD but does not work like AEAD Description: ------------ "chacha20-poly1305" is listed in the result of openssl_get_cipher_methods(). Wikipedia says it is an AEAD. I.e., if I call openssl_encrypt and provide a reference to a variable that is supposed to get the authentication tag, I expect it to get the tag. Instead, I get this warning: PHP Warning: openssl_encrypt(): The authenticated tag cannot be provided for cipher that doesn not support AEAD in /home/aep/aead-test/index.php on line 17 There is a pure PHP implementation of chacha20-poly1305, and it does support the AEAD mode (i.e. gets a tag). It is available as "leigh/aead-chacha20-poly1305" via composer, and the test script below uses it for reference. Test script: --------------- <?php # make sure that you used Composer to get "leigh/aead-chacha20-poly1305" require __DIR__ . '/vendor/autoload.php'; $key = str_repeat('k', 32); $nonce = str_repeat('n', 12); $plaintext = '12345678'; $aad = ''; list($ciphertext, $tag) = \ChaCha20Poly1305\encrypt($key, $nonce, $aad, $plaintext); $cl = implode(unpack("H*", $ciphertext)); $tl = implode(unpack("H*", $tag)); print("Pure PHP\n"); print("Ciphertext: $cl, tag: $tl\n"); $openssl_ct = openssl_encrypt($plaintext, "chacha20-poly1305", $key, OPENSSL_RAW_DATA, $nonce, $openssl_tag, $aad); $ocl = implode(unpack("H*", $openssl_ct)); $otl = implode(unpack("H*", $openssl_tag)); print("OpenSSL\n"); print("Ciphertext: $ocl, tag: $otl\n"); Expected result: ---------------- Pure PHP Ciphertext: bfcd0d66f7e49c21, tag: e48864c53c4deb83bcee96add54ef851 OpenSSL Ciphertext: bfcd0d66f7e49c21, tag: e48864c53c4deb83bcee96add54ef851 Actual result: -------------- Pure PHP Ciphertext: bfcd0d66f7e49c21, tag: e48864c53c4deb83bcee96add54ef851 PHP Warning: openssl_encrypt(): The authenticated tag cannot be provided for cipher that doesn not support AEAD in /home/aep/aead-test/index.php on line 17 OpenSSL Ciphertext: bfcd0d66f7e49c21, tag: -- Edit bug report at https://bugs.php.net/bug.php?id=76935&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=76935&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=76935&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=76935&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=76935&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=76935&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=76935&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=76935&r=needscript Try newer version: https://bugs.php.net/fix.php?id=76935&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=76935&r=support Expected behavior: https://bugs.php.net/fix.php?id=76935&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=76935&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=76935&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=76935&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=76935&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=76935&r=dst IIS Stability: https://bugs.php.net/fix.php?id=76935&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=76935&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=76935&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=76935&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=76935&r=mysqlcfg