of_key k converts k to storage. The result is key_size bytes long.

to_key s converts s to a secret key.

• raises Size_mismatch

  if s is not key_size bytes long

of_nonce n converts n to storage. The result is nonce_size bytes long.

to_nonce s converts s to a nonce.

• raises Size_mismatch

  if s is not nonce_size bytes long

secret_box k m n encrypts and authenticates a message m using a secret key k and a nonce n, and returns the resulting ciphertext.

secret_box_open k c n verifies and decrypts a ciphertext c using a secret key k and a nonce n, and returns the resulting plaintext m.

• raises Verification_failure

  if authenticity of message cannot be verified