1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
using System;
using Org.BouncyCastle.Math.Raw;
using Org.BouncyCastle.Utilities.Encoders;
namespace Org.BouncyCastle.Math.EC.Custom.Sec
{
internal class SecP160R2Curve
: AbstractFpCurve
{
public static readonly BigInteger q = new BigInteger(1,
Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFAC73"));
private const int SECP160R2_DEFAULT_COORDS = COORD_JACOBIAN;
private const int SECP160R2_FE_INTS = 5;
protected readonly SecP160R2Point m_infinity;
public SecP160R2Curve()
: base(q)
{
this.m_infinity = new SecP160R2Point(this, null, null);
this.m_a = FromBigInteger(new BigInteger(1,
Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFAC70")));
this.m_b = FromBigInteger(new BigInteger(1,
Hex.Decode("B4E134D3FB59EB8BAB57274904664D5AF50388BA")));
this.m_order = new BigInteger(1, Hex.Decode("0100000000000000000000351EE786A818F3A1A16B"));
this.m_cofactor = BigInteger.One;
this.m_coord = SECP160R2_DEFAULT_COORDS;
}
protected override ECCurve CloneCurve()
{
return new SecP160R2Curve();
}
public override bool SupportsCoordinateSystem(int coord)
{
switch (coord)
{
case COORD_JACOBIAN:
return true;
default:
return false;
}
}
public virtual BigInteger Q
{
get { return q; }
}
public override ECPoint Infinity
{
get { return m_infinity; }
}
public override int FieldSize
{
get { return q.BitLength; }
}
public override ECFieldElement FromBigInteger(BigInteger x)
{
return new SecP160R2FieldElement(x);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, bool withCompression)
{
return new SecP160R2Point(this, x, y, withCompression);
}
protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, bool withCompression)
{
return new SecP160R2Point(this, x, y, zs, withCompression);
}
public override ECLookupTable CreateCacheSafeLookupTable(ECPoint[] points, int off, int len)
{
uint[] table = new uint[len * SECP160R2_FE_INTS * 2];
{
int pos = 0;
for (int i = 0; i < len; ++i)
{
ECPoint p = points[off + i];
Nat160.Copy(((SecP160R2FieldElement)p.RawXCoord).x, 0, table, pos); pos += SECP160R2_FE_INTS;
Nat160.Copy(((SecP160R2FieldElement)p.RawYCoord).x, 0, table, pos); pos += SECP160R2_FE_INTS;
}
}
return new SecP160R2LookupTable(this, table, len);
}
private class SecP160R2LookupTable
: ECLookupTable
{
private readonly SecP160R2Curve m_outer;
private readonly uint[] m_table;
private readonly int m_size;
internal SecP160R2LookupTable(SecP160R2Curve outer, uint[] table, int size)
{
this.m_outer = outer;
this.m_table = table;
this.m_size = size;
}
public virtual int Size
{
get { return m_size; }
}
public virtual ECPoint Lookup(int index)
{
uint[] x = Nat160.Create(), y = Nat160.Create();
int pos = 0;
for (int i = 0; i < m_size; ++i)
{
uint MASK = (uint)(((i ^ index) - 1) >> 31);
for (int j = 0; j < SECP160R2_FE_INTS; ++j)
{
x[j] ^= m_table[pos + j] & MASK;
y[j] ^= m_table[pos + SECP160R2_FE_INTS + j] & MASK;
}
pos += (SECP160R2_FE_INTS * 2);
}
return m_outer.CreateRawPoint(new SecP160R2FieldElement(x), new SecP160R2FieldElement(y), false);
}
}
}
}
|
