def get_cipher():
 from libnacl import crypto_secretbox_KEYBYTES as KEYLEN
 from libnacl.secret import SecretBox
 def decrypt(ciphertext, key):
  'Decrypt ciphertext using key.'
  return SecretBox(key).decrypt(ciphertext)
 return (KEYLEN, decrypt)

def get_cipher ( ) : from libnacl import crypto_secretbox_KEYBYTES as KEYLEN from libnacl . secret import SecretBox def decrypt ( ciphertext , key ) : return SecretBox ( key ) . decrypt ( ciphertext ) return ( KEYLEN , decrypt )
return decryption function and length of key .