1// Copyright 2009 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
5// Package sha512 implements the SHA-384, SHA-512, SHA-512/224, and SHA-512/256
6// hash algorithms as defined in FIPS 180-4.
7//
8// All the hash.Hash implementations returned by this package also
9// implement encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to
10// marshal and unmarshal the internal state of the hash.
11package sha512
12
13import (
14	"crypto"
15	"errors"
16	"hash"
17)
18
19func init() {
20	crypto.RegisterHash(crypto.SHA384, New384)
21	crypto.RegisterHash(crypto.SHA512, New)
22	crypto.RegisterHash(crypto.SHA512_224, New512_224)
23	crypto.RegisterHash(crypto.SHA512_256, New512_256)
24}
25
26const (
27	// Size is the size, in bytes, of a SHA-512 checksum.
28	Size = 64
29
30	// Size224 is the size, in bytes, of a SHA-512/224 checksum.
31	Size224 = 28
32
33	// Size256 is the size, in bytes, of a SHA-512/256 checksum.
34	Size256 = 32
35
36	// Size384 is the size, in bytes, of a SHA-384 checksum.
37	Size384 = 48
38
39	// BlockSize is the block size, in bytes, of the SHA-512/224,
40	// SHA-512/256, SHA-384 and SHA-512 hash functions.
41	BlockSize = 128
42)
43
44const (
45	chunk     = 128
46	init0     = 0x6a09e667f3bcc908
47	init1     = 0xbb67ae8584caa73b
48	init2     = 0x3c6ef372fe94f82b
49	init3     = 0xa54ff53a5f1d36f1
50	init4     = 0x510e527fade682d1
51	init5     = 0x9b05688c2b3e6c1f
52	init6     = 0x1f83d9abfb41bd6b
53	init7     = 0x5be0cd19137e2179
54	init0_224 = 0x8c3d37c819544da2
55	init1_224 = 0x73e1996689dcd4d6
56	init2_224 = 0x1dfab7ae32ff9c82
57	init3_224 = 0x679dd514582f9fcf
58	init4_224 = 0x0f6d2b697bd44da8
59	init5_224 = 0x77e36f7304c48942
60	init6_224 = 0x3f9d85a86a1d36c8
61	init7_224 = 0x1112e6ad91d692a1
62	init0_256 = 0x22312194fc2bf72c
63	init1_256 = 0x9f555fa3c84c64c2
64	init2_256 = 0x2393b86b6f53b151
65	init3_256 = 0x963877195940eabd
66	init4_256 = 0x96283ee2a88effe3
67	init5_256 = 0xbe5e1e2553863992
68	init6_256 = 0x2b0199fc2c85b8aa
69	init7_256 = 0x0eb72ddc81c52ca2
70	init0_384 = 0xcbbb9d5dc1059ed8
71	init1_384 = 0x629a292a367cd507
72	init2_384 = 0x9159015a3070dd17
73	init3_384 = 0x152fecd8f70e5939
74	init4_384 = 0x67332667ffc00b31
75	init5_384 = 0x8eb44a8768581511
76	init6_384 = 0xdb0c2e0d64f98fa7
77	init7_384 = 0x47b5481dbefa4fa4
78)
79
80// digest represents the partial evaluation of a checksum.
81type digest struct {
82	h        [8]uint64
83	x        [chunk]byte
84	nx       int
85	len      uint64
86	function crypto.Hash
87}
88
89func (d *digest) Reset() {
90	switch d.function {
91	case crypto.SHA384:
92		d.h[0] = init0_384
93		d.h[1] = init1_384
94		d.h[2] = init2_384
95		d.h[3] = init3_384
96		d.h[4] = init4_384
97		d.h[5] = init5_384
98		d.h[6] = init6_384
99		d.h[7] = init7_384
100	case crypto.SHA512_224:
101		d.h[0] = init0_224
102		d.h[1] = init1_224
103		d.h[2] = init2_224
104		d.h[3] = init3_224
105		d.h[4] = init4_224
106		d.h[5] = init5_224
107		d.h[6] = init6_224
108		d.h[7] = init7_224
109	case crypto.SHA512_256:
110		d.h[0] = init0_256
111		d.h[1] = init1_256
112		d.h[2] = init2_256
113		d.h[3] = init3_256
114		d.h[4] = init4_256
115		d.h[5] = init5_256
116		d.h[6] = init6_256
117		d.h[7] = init7_256
118	default:
119		d.h[0] = init0
120		d.h[1] = init1
121		d.h[2] = init2
122		d.h[3] = init3
123		d.h[4] = init4
124		d.h[5] = init5
125		d.h[6] = init6
126		d.h[7] = init7
127	}
128	d.nx = 0
129	d.len = 0
130}
131
132const (
133	magic384      = "sha\x04"
134	magic512_224  = "sha\x05"
135	magic512_256  = "sha\x06"
136	magic512      = "sha\x07"
137	marshaledSize = len(magic512) + 8*8 + chunk + 8
138)
139
140func (d *digest) MarshalBinary() ([]byte, error) {
141	b := make([]byte, 0, marshaledSize)
142	switch d.function {
143	case crypto.SHA384:
144		b = append(b, magic384...)
145	case crypto.SHA512_224:
146		b = append(b, magic512_224...)
147	case crypto.SHA512_256:
148		b = append(b, magic512_256...)
149	case crypto.SHA512:
150		b = append(b, magic512...)
151	default:
152		return nil, errors.New("crypto/sha512: invalid hash function")
153	}
154	b = appendUint64(b, d.h[0])
155	b = appendUint64(b, d.h[1])
156	b = appendUint64(b, d.h[2])
157	b = appendUint64(b, d.h[3])
158	b = appendUint64(b, d.h[4])
159	b = appendUint64(b, d.h[5])
160	b = appendUint64(b, d.h[6])
161	b = appendUint64(b, d.h[7])
162	b = append(b, d.x[:d.nx]...)
163	b = b[:len(b)+len(d.x)-int(d.nx)] // already zero
164	b = appendUint64(b, d.len)
165	return b, nil
166}
167
168func (d *digest) UnmarshalBinary(b []byte) error {
169	if len(b) < len(magic512) {
170		return errors.New("crypto/sha512: invalid hash state identifier")
171	}
172	switch {
173	case d.function == crypto.SHA384 && string(b[:len(magic384)]) == magic384:
174	case d.function == crypto.SHA512_224 && string(b[:len(magic512_224)]) == magic512_224:
175	case d.function == crypto.SHA512_256 && string(b[:len(magic512_256)]) == magic512_256:
176	case d.function == crypto.SHA512 && string(b[:len(magic512)]) == magic512:
177	default:
178		return errors.New("crypto/sha512: invalid hash state identifier")
179	}
180	if len(b) != marshaledSize {
181		return errors.New("crypto/sha512: invalid hash state size")
182	}
183	b = b[len(magic512):]
184	b, d.h[0] = consumeUint64(b)
185	b, d.h[1] = consumeUint64(b)
186	b, d.h[2] = consumeUint64(b)
187	b, d.h[3] = consumeUint64(b)
188	b, d.h[4] = consumeUint64(b)
189	b, d.h[5] = consumeUint64(b)
190	b, d.h[6] = consumeUint64(b)
191	b, d.h[7] = consumeUint64(b)
192	b = b[copy(d.x[:], b):]
193	b, d.len = consumeUint64(b)
194	d.nx = int(d.len) % chunk
195	return nil
196}
197
198func appendUint64(b []byte, x uint64) []byte {
199	a := [8]byte{
200		byte(x >> 56),
201		byte(x >> 48),
202		byte(x >> 40),
203		byte(x >> 32),
204		byte(x >> 24),
205		byte(x >> 16),
206		byte(x >> 8),
207		byte(x),
208	}
209	return append(b, a[:]...)
210}
211
212func consumeUint64(b []byte) ([]byte, uint64) {
213	_ = b[7]
214	x := uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
215		uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
216	return b[8:], x
217}
218
219// New returns a new hash.Hash computing the SHA-512 checksum.
220func New() hash.Hash {
221	d := &digest{function: crypto.SHA512}
222	d.Reset()
223	return d
224}
225
226// New512_224 returns a new hash.Hash computing the SHA-512/224 checksum.
227func New512_224() hash.Hash {
228	d := &digest{function: crypto.SHA512_224}
229	d.Reset()
230	return d
231}
232
233// New512_256 returns a new hash.Hash computing the SHA-512/256 checksum.
234func New512_256() hash.Hash {
235	d := &digest{function: crypto.SHA512_256}
236	d.Reset()
237	return d
238}
239
240// New384 returns a new hash.Hash computing the SHA-384 checksum.
241func New384() hash.Hash {
242	d := &digest{function: crypto.SHA384}
243	d.Reset()
244	return d
245}
246
247func (d *digest) Size() int {
248	switch d.function {
249	case crypto.SHA512_224:
250		return Size224
251	case crypto.SHA512_256:
252		return Size256
253	case crypto.SHA384:
254		return Size384
255	default:
256		return Size
257	}
258}
259
260func (d *digest) BlockSize() int { return BlockSize }
261
262func (d *digest) Write(p []byte) (nn int, err error) {
263	nn = len(p)
264	d.len += uint64(nn)
265	if d.nx > 0 {
266		n := copy(d.x[d.nx:], p)
267		d.nx += n
268		if d.nx == chunk {
269			block(d, d.x[:])
270			d.nx = 0
271		}
272		p = p[n:]
273	}
274	if len(p) >= chunk {
275		n := len(p) &^ (chunk - 1)
276		block(d, p[:n])
277		p = p[n:]
278	}
279	if len(p) > 0 {
280		d.nx = copy(d.x[:], p)
281	}
282	return
283}
284
285func (d0 *digest) Sum(in []byte) []byte {
286	// Make a copy of d0 so that caller can keep writing and summing.
287	d := new(digest)
288	*d = *d0
289	hash := d.checkSum()
290	switch d.function {
291	case crypto.SHA384:
292		return append(in, hash[:Size384]...)
293	case crypto.SHA512_224:
294		return append(in, hash[:Size224]...)
295	case crypto.SHA512_256:
296		return append(in, hash[:Size256]...)
297	default:
298		return append(in, hash[:]...)
299	}
300}
301
302func (d *digest) checkSum() [Size]byte {
303	// Padding. Add a 1 bit and 0 bits until 112 bytes mod 128.
304	len := d.len
305	var tmp [128]byte
306	tmp[0] = 0x80
307	if len%128 < 112 {
308		d.Write(tmp[0 : 112-len%128])
309	} else {
310		d.Write(tmp[0 : 128+112-len%128])
311	}
312
313	// Length in bits.
314	len <<= 3
315	for i := uint(0); i < 16; i++ {
316		tmp[i] = byte(len >> (120 - 8*i))
317	}
318	d.Write(tmp[0:16])
319
320	if d.nx != 0 {
321		panic("d.nx != 0")
322	}
323
324	h := d.h[:]
325	if d.function == crypto.SHA384 {
326		h = d.h[:6]
327	}
328
329	var digest [Size]byte
330	for i, s := range h {
331		digest[i*8] = byte(s >> 56)
332		digest[i*8+1] = byte(s >> 48)
333		digest[i*8+2] = byte(s >> 40)
334		digest[i*8+3] = byte(s >> 32)
335		digest[i*8+4] = byte(s >> 24)
336		digest[i*8+5] = byte(s >> 16)
337		digest[i*8+6] = byte(s >> 8)
338		digest[i*8+7] = byte(s)
339	}
340
341	return digest
342}
343
344// Sum512 returns the SHA512 checksum of the data.
345func Sum512(data []byte) [Size]byte {
346	d := digest{function: crypto.SHA512}
347	d.Reset()
348	d.Write(data)
349	return d.checkSum()
350}
351
352// Sum384 returns the SHA384 checksum of the data.
353func Sum384(data []byte) (sum384 [Size384]byte) {
354	d := digest{function: crypto.SHA384}
355	d.Reset()
356	d.Write(data)
357	sum := d.checkSum()
358	copy(sum384[:], sum[:Size384])
359	return
360}
361
362// Sum512_224 returns the Sum512/224 checksum of the data.
363func Sum512_224(data []byte) (sum224 [Size224]byte) {
364	d := digest{function: crypto.SHA512_224}
365	d.Reset()
366	d.Write(data)
367	sum := d.checkSum()
368	copy(sum224[:], sum[:Size224])
369	return
370}
371
372// Sum512_256 returns the Sum512/256 checksum of the data.
373func Sum512_256(data []byte) (sum256 [Size256]byte) {
374	d := digest{function: crypto.SHA512_256}
375	d.Reset()
376	d.Write(data)
377	sum := d.checkSum()
378	copy(sum256[:], sum[:Size256])
379	return
380}
381