2023-06-21 12:46:23 -04:00

179 lines
3.5 KiB
C#

using System;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Utilities;
namespace Org.BouncyCastle.Crypto.Parameters
{
public class DHParameters
: ICipherParameters
{
private const int DefaultMinimumLength = 160;
private readonly BigInteger p, g, q, j;
private readonly int m, l;
private readonly DHValidationParameters validation;
private static int GetDefaultM(
BigInteger p,
int l)
{
int effectiveL = l != 0 ? l : p.BitLength - 1;
return System.Math.Min(DefaultMinimumLength, effectiveL);
// return DefaultMinimumLength;
}
public DHParameters(
BigInteger p,
BigInteger g)
: this(p, g, null, GetDefaultM(p, 0), 0, null, null)
{
}
public DHParameters(
BigInteger p,
BigInteger g,
BigInteger q)
: this(p, g, q, GetDefaultM(p, 0), 0, null, null)
{
}
public DHParameters(
BigInteger p,
BigInteger g,
BigInteger q,
int l)
: this(p, g, q, GetDefaultM(p, l), l, null, null)
{
}
public DHParameters(
BigInteger p,
BigInteger g,
BigInteger q,
int m,
int l)
: this(p, g, q, m, l, null, null)
{
}
public DHParameters(
BigInteger p,
BigInteger g,
BigInteger q,
BigInteger j,
DHValidationParameters validation)
: this(p, g, q, GetDefaultM(p, 0), 0, j, validation)
{
}
public DHParameters(
BigInteger p,
BigInteger g,
BigInteger q,
int m,
int l,
BigInteger j,
DHValidationParameters validation)
{
if (p == null)
throw new ArgumentNullException("p");
if (g == null)
throw new ArgumentNullException("g");
if (!p.TestBit(0))
throw new ArgumentException("field must be an odd prime", "p");
if (g.CompareTo(BigInteger.Two) < 0
|| g.CompareTo(p.Subtract(BigInteger.Two)) > 0)
throw new ArgumentException("generator must in the range [2, p - 2]", "g");
if (m >= p.BitLength)
throw new ArgumentException("m value must be < bitlength of p", "m");
if (l != 0 && l < m)
throw new ArgumentException("l value must be >= m, or zero", "l");
if (j != null && j.CompareTo(BigInteger.Two) < 0)
throw new ArgumentException("subgroup factor must be >= 2", "j");
this.p = p;
this.g = g;
this.q = q;
this.m = m;
this.l = l;
this.j = j;
this.validation = validation;
}
public BigInteger P
{
get { return p; }
}
public BigInteger G
{
get { return g; }
}
public BigInteger Q
{
get { return q; }
}
public BigInteger J
{
get { return j; }
}
/// <summary>The minimum bitlength of the private value.</summary>
public int M
{
get { return m; }
}
/// <summary>The bitlength of the private value.</summary>
/// <remarks>If zero, bitLength(p) - 1 will be used.</remarks>
public int L
{
get { return l; }
}
public DHValidationParameters ValidationParameters
{
get { return validation; }
}
public override bool Equals(
object obj)
{
if (obj == this)
return true;
DHParameters other = obj as DHParameters;
if (other == null)
return false;
return Equals(other);
}
protected bool Equals(
DHParameters other)
{
return p.Equals(other.p)
&& g.Equals(other.g)
&& Platform.Equals(q, other.q);
}
public override int GetHashCode()
{
int hc = p.GetHashCode() ^ g.GetHashCode();
if (q != null)
{
hc ^= q.GetHashCode();
}
return hc;
}
}
}