xref: /aosp_15_r20/external/tink/go/hybrid/internal/hpke/aead.go (revision e7b1675dde1b92d52ec075b0a92829627f2c52a5)
1// Copyright 2022 Google LLC
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14//
15////////////////////////////////////////////////////////////////////////////////
16
17package hpke
18
19// aead is a package-internal interface for the Hybrid Public Key Encryption
20// (HPKE) authenticated encryption with associated data (AEAD).
21//
22// The HPKE RFC is available at
23// https://www.rfc-editor.org/rfc/rfc9180.html.
24type aead interface {
25	// seal performs authenticated encryption of plaintext and associatedData
26	// using key and nonce.
27	//
28	// https://www.rfc-editor.org/rfc/rfc9180.html#section-5.2
29	seal(key, nonce, plaintext, associatedData []byte) ([]byte, error)
30
31	// open performs authenticated decryption of ciphertext and associatedData
32	// using key and nonce.
33	//
34	// https://www.rfc-editor.org/rfc/rfc9180.html#section-5.2
35	open(key, nonce, ciphertext, associatedData []byte) ([]byte, error)
36
37	// id returns the HPKE AEAD algorithm identifier for the underlying AEAD
38	// implementation.
39	//
40	// https://www.rfc-editor.org/rfc/rfc9180.html#section-7.3
41	id() uint16
42
43	// keyLength returns the length of the key.
44	keyLength() int
45
46	// nonceLength returns the length of the nonce.
47	nonceLength() int
48}
49