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// SHA512 block step.
6// In its own file so that a faster assembly or C version
7// can be substituted easily.
8
9package sha512
10
11import "math/bits"
12
13var _K = []uint64{
14	0x428a2f98d728ae22,
15	0x7137449123ef65cd,
16	0xb5c0fbcfec4d3b2f,
17	0xe9b5dba58189dbbc,
18	0x3956c25bf348b538,
19	0x59f111f1b605d019,
20	0x923f82a4af194f9b,
21	0xab1c5ed5da6d8118,
22	0xd807aa98a3030242,
23	0x12835b0145706fbe,
24	0x243185be4ee4b28c,
25	0x550c7dc3d5ffb4e2,
26	0x72be5d74f27b896f,
27	0x80deb1fe3b1696b1,
28	0x9bdc06a725c71235,
29	0xc19bf174cf692694,
30	0xe49b69c19ef14ad2,
31	0xefbe4786384f25e3,
32	0x0fc19dc68b8cd5b5,
33	0x240ca1cc77ac9c65,
34	0x2de92c6f592b0275,
35	0x4a7484aa6ea6e483,
36	0x5cb0a9dcbd41fbd4,
37	0x76f988da831153b5,
38	0x983e5152ee66dfab,
39	0xa831c66d2db43210,
40	0xb00327c898fb213f,
41	0xbf597fc7beef0ee4,
42	0xc6e00bf33da88fc2,
43	0xd5a79147930aa725,
44	0x06ca6351e003826f,
45	0x142929670a0e6e70,
46	0x27b70a8546d22ffc,
47	0x2e1b21385c26c926,
48	0x4d2c6dfc5ac42aed,
49	0x53380d139d95b3df,
50	0x650a73548baf63de,
51	0x766a0abb3c77b2a8,
52	0x81c2c92e47edaee6,
53	0x92722c851482353b,
54	0xa2bfe8a14cf10364,
55	0xa81a664bbc423001,
56	0xc24b8b70d0f89791,
57	0xc76c51a30654be30,
58	0xd192e819d6ef5218,
59	0xd69906245565a910,
60	0xf40e35855771202a,
61	0x106aa07032bbd1b8,
62	0x19a4c116b8d2d0c8,
63	0x1e376c085141ab53,
64	0x2748774cdf8eeb99,
65	0x34b0bcb5e19b48a8,
66	0x391c0cb3c5c95a63,
67	0x4ed8aa4ae3418acb,
68	0x5b9cca4f7763e373,
69	0x682e6ff3d6b2b8a3,
70	0x748f82ee5defb2fc,
71	0x78a5636f43172f60,
72	0x84c87814a1f0ab72,
73	0x8cc702081a6439ec,
74	0x90befffa23631e28,
75	0xa4506cebde82bde9,
76	0xbef9a3f7b2c67915,
77	0xc67178f2e372532b,
78	0xca273eceea26619c,
79	0xd186b8c721c0c207,
80	0xeada7dd6cde0eb1e,
81	0xf57d4f7fee6ed178,
82	0x06f067aa72176fba,
83	0x0a637dc5a2c898a6,
84	0x113f9804bef90dae,
85	0x1b710b35131c471b,
86	0x28db77f523047d84,
87	0x32caab7b40c72493,
88	0x3c9ebe0a15c9bebc,
89	0x431d67c49c100d4c,
90	0x4cc5d4becb3e42b6,
91	0x597f299cfc657e2a,
92	0x5fcb6fab3ad6faec,
93	0x6c44198c4a475817,
94}
95
96func blockGeneric(dig *digest, p []byte) {
97	var w [80]uint64
98	h0, h1, h2, h3, h4, h5, h6, h7 := dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7]
99	for len(p) >= chunk {
100		for i := 0; i < 16; i++ {
101			j := i * 8
102			w[i] = uint64(p[j])<<56 | uint64(p[j+1])<<48 | uint64(p[j+2])<<40 | uint64(p[j+3])<<32 |
103				uint64(p[j+4])<<24 | uint64(p[j+5])<<16 | uint64(p[j+6])<<8 | uint64(p[j+7])
104		}
105		for i := 16; i < 80; i++ {
106			v1 := w[i-2]
107			t1 := bits.RotateLeft64(v1, -19) ^ bits.RotateLeft64(v1, -61) ^ (v1 >> 6)
108			v2 := w[i-15]
109			t2 := bits.RotateLeft64(v2, -1) ^ bits.RotateLeft64(v2, -8) ^ (v2 >> 7)
110
111			w[i] = t1 + w[i-7] + t2 + w[i-16]
112		}
113
114		a, b, c, d, e, f, g, h := h0, h1, h2, h3, h4, h5, h6, h7
115
116		for i := 0; i < 80; i++ {
117			t1 := h + (bits.RotateLeft64(e, -14) ^ bits.RotateLeft64(e, -18) ^ bits.RotateLeft64(e, -41)) + ((e & f) ^ (^e & g)) + _K[i] + w[i]
118
119			t2 := (bits.RotateLeft64(a, -28) ^ bits.RotateLeft64(a, -34) ^ bits.RotateLeft64(a, -39)) + ((a & b) ^ (a & c) ^ (b & c))
120
121			h = g
122			g = f
123			f = e
124			e = d + t1
125			d = c
126			c = b
127			b = a
128			a = t1 + t2
129		}
130
131		h0 += a
132		h1 += b
133		h2 += c
134		h3 += d
135		h4 += e
136		h5 += f
137		h6 += g
138		h7 += h
139
140		p = p[chunk:]
141	}
142
143	dig.h[0], dig.h[1], dig.h[2], dig.h[3], dig.h[4], dig.h[5], dig.h[6], dig.h[7] = h0, h1, h2, h3, h4, h5, h6, h7
144}
145