The detached interface uses 2 separate buffers for the ciphertext and the message authentication tag. This allows users to encrypt and decrypt data in-place, by passing the same buffer for both plaintext and ciphertext.
Buffers have the following size requirements:
tag: 16 bytespk, sk, ck: 32 bytesn: 24 bytesbox pt n pk sk ct tag authenticates and encrypts plaintext pt using public key pk, secret key sk, and nonce n and writes the ciphertext in ct and the message authentication tag in tag. Returns true if successful.
box_open ct tag n pk sk pt attempts to verify and decrypt ciphertext ct and message authentication tag tag using public key pk, secret key sk, and nonce n and if successful writes the plaintext in pt and returns true.
The shared key ck is obtained using NaCl.box_beforenm or NaCl.Noalloc.box_beforenm.
box_afternm pt n ck ct tag authenticates and encrypts pt using shared key ck and nonce n and writes the ciphertext in ct and the message authentication tag in tag. Returns true if successful.
box_open_afternm ct tag n ck pt attempts to verify and decrypt ciphertext ct and message authentication tag tag using shared key ck and nonce n and if successful writes the plaintext in pt and returns true.
secretbox pt n key ct tag authenticates and encrypts plaintext pt using secret key key and nonce n and writes the ciphertext in ct and the message authentication tag in tag. Returns true if successful.