1// Copyright 2014 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package sha3
6
7// This file provides functions for creating instances of the SHA-3
8// and SHAKE hash functions, as well as utility functions for hashing
9// bytes.
10
11import (
12	"hash"
13)
14
15// New224 creates a new SHA3-224 hash.
16// Its generic security strength is 224 bits against preimage attacks,
17// and 112 bits against collision attacks.
18func New224() hash.Hash {
19	if h := new224Asm(); h != nil {
20		return h
21	}
22	return &state{rate: 144, outputLen: 28, dsbyte: 0x06}
23}
24
25// New256 creates a new SHA3-256 hash.
26// Its generic security strength is 256 bits against preimage attacks,
27// and 128 bits against collision attacks.
28func New256() hash.Hash {
29	if h := new256Asm(); h != nil {
30		return h
31	}
32	return &state{rate: 136, outputLen: 32, dsbyte: 0x06}
33}
34
35// New384 creates a new SHA3-384 hash.
36// Its generic security strength is 384 bits against preimage attacks,
37// and 192 bits against collision attacks.
38func New384() hash.Hash {
39	if h := new384Asm(); h != nil {
40		return h
41	}
42	return &state{rate: 104, outputLen: 48, dsbyte: 0x06}
43}
44
45// New512 creates a new SHA3-512 hash.
46// Its generic security strength is 512 bits against preimage attacks,
47// and 256 bits against collision attacks.
48func New512() hash.Hash {
49	if h := new512Asm(); h != nil {
50		return h
51	}
52	return &state{rate: 72, outputLen: 64, dsbyte: 0x06}
53}
54
55// NewLegacyKeccak256 creates a new Keccak-256 hash.
56//
57// Only use this function if you require compatibility with an existing cryptosystem
58// that uses non-standard padding. All other users should use New256 instead.
59func NewLegacyKeccak256() hash.Hash { return &state{rate: 136, outputLen: 32, dsbyte: 0x01} }
60
61// NewLegacyKeccak512 creates a new Keccak-512 hash.
62//
63// Only use this function if you require compatibility with an existing cryptosystem
64// that uses non-standard padding. All other users should use New512 instead.
65func NewLegacyKeccak512() hash.Hash { return &state{rate: 72, outputLen: 64, dsbyte: 0x01} }
66
67// Sum224 returns the SHA3-224 digest of the data.
68func Sum224(data []byte) (digest [28]byte) {
69	h := New224()
70	h.Write(data)
71	h.Sum(digest[:0])
72	return
73}
74
75// Sum256 returns the SHA3-256 digest of the data.
76func Sum256(data []byte) (digest [32]byte) {
77	h := New256()
78	h.Write(data)
79	h.Sum(digest[:0])
80	return
81}
82
83// Sum384 returns the SHA3-384 digest of the data.
84func Sum384(data []byte) (digest [48]byte) {
85	h := New384()
86	h.Write(data)
87	h.Sum(digest[:0])
88	return
89}
90
91// Sum512 returns the SHA3-512 digest of the data.
92func Sum512(data []byte) (digest [64]byte) {
93	h := New512()
94	h.Write(data)
95	h.Sum(digest[:0])
96	return
97}
98