package noise import ( "errors" ) // encrypt calls the cipher's encryption. It encrypts the provided plaintext, // slice-appending the ciphertext on out. // // Usually you want to pass a 0-len slice to this method, with enough capacity // to accommodate the ciphertext in order to spare allocs. // // encrypt returns a new slice header, whose len is the length of the resulting // ciphertext, including the authentication tag. // // This method will not allocate if the supplied slice is large enough to // accommodate the encrypted data + authentication tag. If so, the returned // slice header should be a view of the original slice. // // With the poly1305 MAC function that noise-libp2p uses, the authentication tag // adds an overhead of 16 bytes. func (s *secureSession) encrypt(out, plaintext []byte) ([]byte, error) { if s.enc == nil { return nil, errors.New("cannot encrypt, handshake incomplete") } return s.enc.Encrypt(out, nil, plaintext) } // decrypt calls the cipher's decryption. It decrypts the provided ciphertext, // slice-appending the plaintext on out. // // Usually you want to pass a 0-len slice to this method, with enough capacity // to accommodate the plaintext in order to spare allocs. // // decrypt returns a new slice header, whose len is the length of the resulting // plaintext, without the authentication tag. // // This method will not allocate if the supplied slice is large enough to // accommodate the plaintext. If so, the returned slice header should be a view // of the original slice. func (s *secureSession) decrypt(out, ciphertext []byte) ([]byte, error) { if s.dec == nil { return nil, errors.New("cannot decrypt, handshake incomplete") } return s.dec.Decrypt(out, nil, ciphertext) }