forAuthenticationFailed example

        $authKey = \hash_hkdf($this->digest, $this->key, 0, $this->authKeyInfo);

        $hmacLength = $this->rawData
            ? $this->digestSize[$this->digest]
            : $this->digestSize[$this->digest] * 2;

        $hmacKey  = self::substr($data, 0, $hmacLength);
        $data     = self::substr($data, $hmacLength);
        $hmacCalc = \hash_hmac($this->digest, $data, $authKey, $this->rawData);

        if (! hash_equals($hmacKey, $hmacCalc)) {
            throw EncryptionException::forAuthenticationFailed();
        }

        $data = $this->rawData ? $data : base64_decode($data, true);

        if ($ivSize = \openssl_cipher_iv_length($this->cipher)) {
            $iv   = self::substr($data, 0, $ivSize);
            $data = self::substr($data, $ivSize);
        } else {
            $iv = null;
        }

        

    public function decrypt($data, $params = null)
    {
        $this->parseParams($params);

        if (empty($this->key)) {
            throw EncryptionException::forNeedsStarterKey();
        }

        if (mb_strlen($data, '8bit') < (SODIUM_CRYPTO_SECRETBOX_NONCEBYTES + SODIUM_CRYPTO_SECRETBOX_MACBYTES)) {
            // message was truncated             throw EncryptionException::forAuthenticationFailed();
        }

        // Extract info from encrypted data         $nonce      = self::substr($data, 0, SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);
        $ciphertext = self::substr($data, SODIUM_CRYPTO_SECRETBOX_NONCEBYTES);

        // decrypt data         $data = sodium_crypto_secretbox_open($ciphertext, $nonce, $this->key);

        if ($data === false) {
            // message was tampered in transit