1 package x448
2
3 import (
4 "encoding/binary"
5 "math/bits"
6
7 "github.com/cloudflare/circl/math/fp448"
8 )
9
10 func doubleGeneric(x, z *fp448.Elt) {
11 t0, t1 := &fp448.Elt{}, &fp448.Elt{}
12 fp448.AddSub(x, z)
13 fp448.Sqr(x, x)
14 fp448.Sqr(z, z)
15 fp448.Sub(t0, x, z)
16 mulA24Generic(t1, t0)
17 fp448.Add(t1, t1, z)
18 fp448.Mul(x, x, z)
19 fp448.Mul(z, t0, t1)
20 }
21
22 func diffAddGeneric(w *[5]fp448.Elt, b uint) {
23 mu, x1, z1, x2, z2 := &w[0], &w[1], &w[2], &w[3], &w[4]
24 fp448.Cswap(x1, x2, b)
25 fp448.Cswap(z1, z2, b)
26 fp448.AddSub(x1, z1)
27 fp448.Mul(z1, z1, mu)
28 fp448.AddSub(x1, z1)
29 fp448.Sqr(x1, x1)
30 fp448.Sqr(z1, z1)
31 fp448.Mul(x1, x1, z2)
32 fp448.Mul(z1, z1, x2)
33 }
34
35 func ladderStepGeneric(w *[5]fp448.Elt, b uint) {
36 x1, x2, z2, x3, z3 := &w[0], &w[1], &w[2], &w[3], &w[4]
37 t0 := &fp448.Elt{}
38 t1 := &fp448.Elt{}
39 fp448.AddSub(x2, z2)
40 fp448.AddSub(x3, z3)
41 fp448.Mul(t0, x2, z3)
42 fp448.Mul(t1, x3, z2)
43 fp448.AddSub(t0, t1)
44 fp448.Cmov(x2, x3, b)
45 fp448.Cmov(z2, z3, b)
46 fp448.Sqr(x3, t0)
47 fp448.Sqr(z3, t1)
48 fp448.Mul(z3, x1, z3)
49 fp448.Sqr(x2, x2)
50 fp448.Sqr(z2, z2)
51 fp448.Sub(t0, x2, z2)
52 mulA24Generic(t1, t0)
53 fp448.Add(t1, t1, z2)
54 fp448.Mul(x2, x2, z2)
55 fp448.Mul(z2, t0, t1)
56 }
57
58 func mulA24Generic(z, x *fp448.Elt) {
59 const A24 = 39082
60 const n = 8
61 var xx [7]uint64
62 for i := range xx {
63 xx[i] = binary.LittleEndian.Uint64(x[i*n : (i+1)*n])
64 }
65 h0, l0 := bits.Mul64(xx[0], A24)
66 h1, l1 := bits.Mul64(xx[1], A24)
67 h2, l2 := bits.Mul64(xx[2], A24)
68 h3, l3 := bits.Mul64(xx[3], A24)
69 h4, l4 := bits.Mul64(xx[4], A24)
70 h5, l5 := bits.Mul64(xx[5], A24)
71 h6, l6 := bits.Mul64(xx[6], A24)
72
73 l1, c0 := bits.Add64(h0, l1, 0)
74 l2, c1 := bits.Add64(h1, l2, c0)
75 l3, c2 := bits.Add64(h2, l3, c1)
76 l4, c3 := bits.Add64(h3, l4, c2)
77 l5, c4 := bits.Add64(h4, l5, c3)
78 l6, c5 := bits.Add64(h5, l6, c4)
79 l7, _ := bits.Add64(h6, 0, c5)
80
81 l0, c0 = bits.Add64(l0, l7, 0)
82 l1, c1 = bits.Add64(l1, 0, c0)
83 l2, c2 = bits.Add64(l2, 0, c1)
84 l3, c3 = bits.Add64(l3, l7<<32, c2)
85 l4, c4 = bits.Add64(l4, 0, c3)
86 l5, c5 = bits.Add64(l5, 0, c4)
87 l6, l7 = bits.Add64(l6, 0, c5)
88
89 xx[0], c0 = bits.Add64(l0, l7, 0)
90 xx[1], c1 = bits.Add64(l1, 0, c0)
91 xx[2], c2 = bits.Add64(l2, 0, c1)
92 xx[3], c3 = bits.Add64(l3, l7<<32, c2)
93 xx[4], c4 = bits.Add64(l4, 0, c3)
94 xx[5], c5 = bits.Add64(l5, 0, c4)
95 xx[6], _ = bits.Add64(l6, 0, c5)
96
97 for i := range xx {
98 binary.LittleEndian.PutUint64(z[i*n:(i+1)*n], xx[i])
99 }
100 }
101
View as plain text