auth_tag=

        # OpenSSL::Cipher.auth_tag=

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

---

Sets the authentication tag to verify the integrity of the ciphertext.
This can be called only when the cipher supports AE. The tag must be set
after calling Cipher#decrypt, Cipher#key= and Cipher#iv=, but before
calling Cipher#final. After all decryption is performed, the tag is
verified automatically in the call to Cipher#final.

For OCB mode, the tag length must be supplied with #auth_tag_len=
beforehand.