final

        # OpenSSL::Cipher.final

(from ruby core)
### Implementation from Cipher
---
    cipher.final -> string

---

Returns the remaining data held in the cipher object. Further calls to
Cipher#update or Cipher#final will return garbage. This call should
always be made as the last call of an encryption or decryption
operation, after having fed the entire plaintext or ciphertext to the
Cipher instance.

If an authenticated cipher was used, a CipherError is raised if the tag
could not be authenticated successfully. Only call this method after
setting the authentication tag and passing the entire contents of the
ciphertext into the cipher.