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	"encoding/binary"
16	"errors"
17	"hash"
18)
19
20func init() {
21	crypto.RegisterHash(crypto.SHA384, New384)
22	crypto.RegisterHash(crypto.SHA512, New)
23	crypto.RegisterHash(crypto.SHA512_224, New512_224)
24	crypto.RegisterHash(crypto.SHA512_256, New512_256)
25}
26
27const (
28	// Size is the size, in bytes, of a SHA-512 checksum.
29	Size = 64
30
31	// Size224 is the size, in bytes, of a SHA-512/224 checksum.
32	Size224 = 28
33
34	// Size256 is the size, in bytes, of a SHA-512/256 checksum.
35	Size256 = 32
36
37	// Size384 is the size, in bytes, of a SHA-384 checksum.
38	Size384 = 48
39
40	// BlockSize is the block size, in bytes, of the SHA-512/224,
41	// SHA-512/256, SHA-384 and SHA-512 hash functions.
42	BlockSize = 128
43)
44
45const (
46	chunk     = 128
47	init0     = 0x6a09e667f3bcc908
48	init1     = 0xbb67ae8584caa73b
49	init2     = 0x3c6ef372fe94f82b
50	init3     = 0xa54ff53a5f1d36f1
51	init4     = 0x510e527fade682d1
52	init5     = 0x9b05688c2b3e6c1f
53	init6     = 0x1f83d9abfb41bd6b
54	init7     = 0x5be0cd19137e2179
55	init0_224 = 0x8c3d37c819544da2
56	init1_224 = 0x73e1996689dcd4d6
57	init2_224 = 0x1dfab7ae32ff9c82
58	init3_224 = 0x679dd514582f9fcf
59	init4_224 = 0x0f6d2b697bd44da8
60	init5_224 = 0x77e36f7304c48942
61	init6_224 = 0x3f9d85a86a1d36c8
62	init7_224 = 0x1112e6ad91d692a1
63	init0_256 = 0x22312194fc2bf72c
64	init1_256 = 0x9f555fa3c84c64c2
65	init2_256 = 0x2393b86b6f53b151
66	init3_256 = 0x963877195940eabd
67	init4_256 = 0x96283ee2a88effe3
68	init5_256 = 0xbe5e1e2553863992
69	init6_256 = 0x2b0199fc2c85b8aa
70	init7_256 = 0x0eb72ddc81c52ca2
71	init0_384 = 0xcbbb9d5dc1059ed8
72	init1_384 = 0x629a292a367cd507
73	init2_384 = 0x9159015a3070dd17
74	init3_384 = 0x152fecd8f70e5939
75	init4_384 = 0x67332667ffc00b31
76	init5_384 = 0x8eb44a8768581511
77	init6_384 = 0xdb0c2e0d64f98fa7
78	init7_384 = 0x47b5481dbefa4fa4
79)
80
81// digest represents the partial evaluation of a checksum.
82type digest struct {
83	h        [8]uint64
84	x        [chunk]byte
85	nx       int
86	len      uint64
87	function crypto.Hash
88}
89
90func (d *digest) Reset() {
91	switch d.function {
92	case crypto.SHA384:
93		d.h[0] = init0_384
94		d.h[1] = init1_384
95		d.h[2] = init2_384
96		d.h[3] = init3_384
97		d.h[4] = init4_384
98		d.h[5] = init5_384
99		d.h[6] = init6_384
100		d.h[7] = init7_384
101	case crypto.SHA512_224:
102		d.h[0] = init0_224
103		d.h[1] = init1_224
104		d.h[2] = init2_224
105		d.h[3] = init3_224
106		d.h[4] = init4_224
107		d.h[5] = init5_224
108		d.h[6] = init6_224
109		d.h[7] = init7_224
110	case crypto.SHA512_256:
111		d.h[0] = init0_256
112		d.h[1] = init1_256
113		d.h[2] = init2_256
114		d.h[3] = init3_256
115		d.h[4] = init4_256
116		d.h[5] = init5_256
117		d.h[6] = init6_256
118		d.h[7] = init7_256
119	default:
120		d.h[0] = init0
121		d.h[1] = init1
122		d.h[2] = init2
123		d.h[3] = init3
124		d.h[4] = init4
125		d.h[5] = init5
126		d.h[6] = init6
127		d.h[7] = init7
128	}
129	d.nx = 0
130	d.len = 0
131}
132
133const (
134	magic384      = "sha\x04"
135	magic512_224  = "sha\x05"
136	magic512_256  = "sha\x06"
137	magic512      = "sha\x07"
138	marshaledSize = len(magic512) + 8*8 + chunk + 8
139)
140
141func (d *digest) MarshalBinary() ([]byte, error) {
142	b := make([]byte, 0, marshaledSize)
143	switch d.function {
144	case crypto.SHA384:
145		b = append(b, magic384...)
146	case crypto.SHA512_224:
147		b = append(b, magic512_224...)
148	case crypto.SHA512_256:
149		b = append(b, magic512_256...)
150	case crypto.SHA512:
151		b = append(b, magic512...)
152	default:
153		return nil, errors.New("crypto/sha512: invalid hash function")
154	}
155	b = appendUint64(b, d.h[0])
156	b = appendUint64(b, d.h[1])
157	b = appendUint64(b, d.h[2])
158	b = appendUint64(b, d.h[3])
159	b = appendUint64(b, d.h[4])
160	b = appendUint64(b, d.h[5])
161	b = appendUint64(b, d.h[6])
162	b = appendUint64(b, d.h[7])
163	b = append(b, d.x[:d.nx]...)
164	b = b[:len(b)+len(d.x)-int(d.nx)] // already zero
165	b = appendUint64(b, d.len)
166	return b, nil
167}
168
169func (d *digest) UnmarshalBinary(b []byte) error {
170	if len(b) < len(magic512) {
171		return errors.New("crypto/sha512: invalid hash state identifier")
172	}
173	switch {
174	case d.function == crypto.SHA384 && string(b[:len(magic384)]) == magic384:
175	case d.function == crypto.SHA512_224 && string(b[:len(magic512_224)]) == magic512_224:
176	case d.function == crypto.SHA512_256 && string(b[:len(magic512_256)]) == magic512_256:
177	case d.function == crypto.SHA512 && string(b[:len(magic512)]) == magic512:
178	default:
179		return errors.New("crypto/sha512: invalid hash state identifier")
180	}
181	if len(b) != marshaledSize {
182		return errors.New("crypto/sha512: invalid hash state size")
183	}
184	b = b[len(magic512):]
185	b, d.h[0] = consumeUint64(b)
186	b, d.h[1] = consumeUint64(b)
187	b, d.h[2] = consumeUint64(b)
188	b, d.h[3] = consumeUint64(b)
189	b, d.h[4] = consumeUint64(b)
190	b, d.h[5] = consumeUint64(b)
191	b, d.h[6] = consumeUint64(b)
192	b, d.h[7] = consumeUint64(b)
193	b = b[copy(d.x[:], b):]
194	b, d.len = consumeUint64(b)
195	d.nx = int(d.len % chunk)
196	return nil
197}
198
199func appendUint64(b []byte, x uint64) []byte {
200	var a [8]byte
201	binary.BigEndian.PutUint64(a[:], x)
202	return append(b, a[:]...)
203}
204
205func consumeUint64(b []byte) ([]byte, uint64) {
206	_ = b[7]
207	x := uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
208		uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56
209	return b[8:], x
210}
211
212// New returns a new hash.Hash computing the SHA-512 checksum.
213func New() hash.Hash {
214	d := &digest{function: crypto.SHA512}
215	d.Reset()
216	return d
217}
218
219// New512_224 returns a new hash.Hash computing the SHA-512/224 checksum.
220func New512_224() hash.Hash {
221	d := &digest{function: crypto.SHA512_224}
222	d.Reset()
223	return d
224}
225
226// New512_256 returns a new hash.Hash computing the SHA-512/256 checksum.
227func New512_256() hash.Hash {
228	d := &digest{function: crypto.SHA512_256}
229	d.Reset()
230	return d
231}
232
233// New384 returns a new hash.Hash computing the SHA-384 checksum.
234func New384() hash.Hash {
235	d := &digest{function: crypto.SHA384}
236	d.Reset()
237	return d
238}
239
240func (d *digest) Size() int {
241	switch d.function {
242	case crypto.SHA512_224:
243		return Size224
244	case crypto.SHA512_256:
245		return Size256
246	case crypto.SHA384:
247		return Size384
248	default:
249		return Size
250	}
251}
252
253func (d *digest) BlockSize() int { return BlockSize }
254
255func (d *digest) Write(p []byte) (nn int, err error) {
256	nn = len(p)
257	d.len += uint64(nn)
258	if d.nx > 0 {
259		n := copy(d.x[d.nx:], p)
260		d.nx += n
261		if d.nx == chunk {
262			block(d, d.x[:])
263			d.nx = 0
264		}
265		p = p[n:]
266	}
267	if len(p) >= chunk {
268		n := len(p) &^ (chunk - 1)
269		block(d, p[:n])
270		p = p[n:]
271	}
272	if len(p) > 0 {
273		d.nx = copy(d.x[:], p)
274	}
275	return
276}
277
278func (d *digest) Sum(in []byte) []byte {
279	// Make a copy of d so that caller can keep writing and summing.
280	d0 := new(digest)
281	*d0 = *d
282	hash := d0.checkSum()
283	switch d0.function {
284	case crypto.SHA384:
285		return append(in, hash[:Size384]...)
286	case crypto.SHA512_224:
287		return append(in, hash[:Size224]...)
288	case crypto.SHA512_256:
289		return append(in, hash[:Size256]...)
290	default:
291		return append(in, hash[:]...)
292	}
293}
294
295func (d *digest) checkSum() [Size]byte {
296	// Padding. Add a 1 bit and 0 bits until 112 bytes mod 128.
297	len := d.len
298	var tmp [128]byte
299	tmp[0] = 0x80
300	if len%128 < 112 {
301		d.Write(tmp[0 : 112-len%128])
302	} else {
303		d.Write(tmp[0 : 128+112-len%128])
304	}
305
306	// Length in bits.
307	len <<= 3
308	binary.BigEndian.PutUint64(tmp[0:], 0) // upper 64 bits are always zero, because len variable has type uint64
309	binary.BigEndian.PutUint64(tmp[8:], len)
310	d.Write(tmp[0:16])
311
312	if d.nx != 0 {
313		panic("d.nx != 0")
314	}
315
316	var digest [Size]byte
317	binary.BigEndian.PutUint64(digest[0:], d.h[0])
318	binary.BigEndian.PutUint64(digest[8:], d.h[1])
319	binary.BigEndian.PutUint64(digest[16:], d.h[2])
320	binary.BigEndian.PutUint64(digest[24:], d.h[3])
321	binary.BigEndian.PutUint64(digest[32:], d.h[4])
322	binary.BigEndian.PutUint64(digest[40:], d.h[5])
323	if d.function != crypto.SHA384 {
324		binary.BigEndian.PutUint64(digest[48:], d.h[6])
325		binary.BigEndian.PutUint64(digest[56:], d.h[7])
326	}
327
328	return digest
329}
330
331// Sum512 returns the SHA512 checksum of the data.
332func Sum512(data []byte) [Size]byte {
333	d := digest{function: crypto.SHA512}
334	d.Reset()
335	d.Write(data)
336	return d.checkSum()
337}
338
339// Sum384 returns the SHA384 checksum of the data.
340func Sum384(data []byte) (sum384 [Size384]byte) {
341	d := digest{function: crypto.SHA384}
342	d.Reset()
343	d.Write(data)
344	sum := d.checkSum()
345	copy(sum384[:], sum[:Size384])
346	return
347}
348
349// Sum512_224 returns the Sum512/224 checksum of the data.
350func Sum512_224(data []byte) (sum224 [Size224]byte) {
351	d := digest{function: crypto.SHA512_224}
352	d.Reset()
353	d.Write(data)
354	sum := d.checkSum()
355	copy(sum224[:], sum[:Size224])
356	return
357}
358
359// Sum512_256 returns the Sum512/256 checksum of the data.
360func Sum512_256(data []byte) (sum256 [Size256]byte) {
361	d := digest{function: crypto.SHA512_256}
362	d.Reset()
363	d.Write(data)
364	sum := d.checkSum()
365	copy(sum256[:], sum[:Size256])
366	return
367}
368