Defuse\Crypto\RuntimeTests::HKDFTestVector PHP Method

    private static function HKDFTestVector()
    {
        // HKDF test vectors from RFC 5869
        // Test Case 1
        $ikm = \str_repeat("\v", 22);
        $salt = Encoding::hexToBin('000102030405060708090a0b0c');
        $info = Encoding::hexToBin('f0f1f2f3f4f5f6f7f8f9');
        $length = 42;
        $okm = Encoding::hexToBin('3cb25f25faacd57a90434f64d0362f2a' . '2d2d0a90cf1a5a4c5db02d56ecc4c5bf' . '34007208d5b887185865');
        $computed_okm = Core::HKDF('sha256', $ikm, $length, $info, $salt);
        if ($computed_okm !== $okm) {
            throw new Ex\EnvironmentIsBrokenException();
        }
        // Test Case 7
        $ikm = \str_repeat("\f", 22);
        $length = 42;
        $okm = Encoding::hexToBin('2c91117204d745f3500d636a62f64f0a' . 'b3bae548aa53d423b0d1f27ebba6f5e5' . '673a081d70cce7acfc48');
        $computed_okm = Core::HKDF('sha1', $ikm, $length, '', null);
        if ($computed_okm !== $okm) {
            throw new Ex\EnvironmentIsBrokenException();
        }
    }

 /**
  * Runs the runtime tests.
  *
  * @throws Ex\EnvironmentIsBrokenException
  */
 public static function runtimeTest()
 {
     // 0: Tests haven't been run yet.
     // 1: Tests have passed.
     // 2: Tests are running right now.
     // 3: Tests have failed.
     static $test_state = 0;
     if ($test_state === 1 || $test_state === 2) {
         return;
     }
     if ($test_state === 3) {
         /* If an intermittent problem caused a test to fail previously, we
          * want that to be indicated to the user with every call to this
          * library. This way, if the user first does something they really
          * don't care about, and just ignores all exceptions, they won't get
          * screwed when they then start to use the library for something
          * they do care about. */
         throw new Ex\EnvironmentIsBrokenException('Tests failed previously.');
     }
     try {
         $test_state = 2;
         Core::ensureFunctionExists('openssl_get_cipher_methods');
         if (\in_array(Core::CIPHER_METHOD, \openssl_get_cipher_methods()) === false) {
             throw new Ex\EnvironmentIsBrokenException('Cipher method not supported. This is normally caused by an outdated ' . 'version of OpenSSL (and/or OpenSSL compiled for FIPS compliance). ' . 'Please upgrade to a newer version of OpenSSL that supports ' . Core::CIPHER_METHOD . ' to use this library.');
         }
         RuntimeTests::AESTestVector();
         RuntimeTests::HMACTestVector();
         RuntimeTests::HKDFTestVector();
         RuntimeTests::testEncryptDecrypt();
         if (Core::ourStrlen(Key::createNewRandomKey()->getRawBytes()) != Core::KEY_BYTE_SIZE) {
             throw new Ex\EnvironmentIsBrokenException();
         }
         if (Core::ENCRYPTION_INFO_STRING == Core::AUTHENTICATION_INFO_STRING) {
             throw new Ex\EnvironmentIsBrokenException();
         }
     } catch (Ex\EnvironmentIsBrokenException $ex) {
         // Do this, otherwise it will stay in the "tests are running" state.
         $test_state = 3;
         throw $ex;
     }
     // Change this to '0' make the tests always re-run (for benchmarking).
     $test_state = 1;
 }