private DiffieHellmanGroup(DiffieHellmanGroupType group, int keySize, BigInteger p, BigInteger g)
{
_group = group;
_keySize = keySize;
_p = p;
_g = g;
}
public DiffieHellman(DiffieHellmanPublicKey publicKey, KeyAgreementKeyDerivationFunction kdFunc, KeyAgreementKeyDerivationHashAlgorithm kdHashAlgo)
: base(kdFunc, kdHashAlgo)
{
_group = DiffieHellmanGroupType.None;
_keySize = publicKey.KeySize;
_p = publicKey.P;
_g = publicKey.G;
_privateKey = GeneratePrivateKey(_p);
}
public DiffieHellmanPublicKey(int keySize, BigInteger p, BigInteger g, BigInteger x)
{
_group = DiffieHellmanGroupType.None;
_keySize = keySize;
_p = p;
_g = g;
_x = x;
VerifyPublicKey(_keySize, _p, _g, _x);
}
public DiffieHellmanPublicKey(DiffieHellmanGroupType group, int keySize, BigInteger x)
{
_group = group;
_keySize = keySize;
_x = x;
DiffieHellmanGroup dhg = DiffieHellmanGroup.GetGroup(group, keySize);
VerifyPublicKey(_keySize, dhg.P, dhg.G, x);
}
public DiffieHellman(DiffieHellmanGroupType group, KeyAgreementKeyDerivationFunction kdFunc, KeyAgreementKeyDerivationHashAlgorithm kdHashAlgo)
: base(kdFunc, kdHashAlgo)
{
_group = group;
DiffieHellmanGroup dhg = DiffieHellmanGroup.GetGroup(_group);
_keySize = dhg.KeySize;
_p = dhg.P;
_g = dhg.G;
_privateKey = GeneratePrivateKey(_p);
}
public static DiffieHellmanGroup GetGroup(DiffieHellmanGroupType group)
{
switch (group)
{
case DiffieHellmanGroupType.RFC3526_GROUP14_2048BIT:
return(new DiffieHellmanGroup(group, 2048, new BigInteger(p2048), new BigInteger(2)));
case DiffieHellmanGroupType.RFC3526_GROUP15_3072BIT:
return(new DiffieHellmanGroup(group, 3072, new BigInteger(p3072), new BigInteger(2)));
case DiffieHellmanGroupType.RFC3526_GROUP16_4096BIT:
return(new DiffieHellmanGroup(group, 4096, new BigInteger(p4096), new BigInteger(2)));
default:
throw new CryptoException("DiffieHellman group not supported.");
}
}
public DiffieHellmanPublicKey(byte[] publicKey)
{
using (MemoryStream mS = new MemoryStream(publicKey, false))
{
BinaryReader bR = new BinaryReader(mS);
if (Encoding.ASCII.GetString(bR.ReadBytes(2)) != "DH")
{
throw new InvalidDataException("Invalid DiffieHellmanPublicKey data format.");
}
switch (bR.ReadByte()) //version
{
case 2:
_keySize = bR.ReadInt32();
_group = (DiffieHellmanGroupType)bR.ReadByte();
switch (_group)
{
case DiffieHellmanGroupType.RFC3526:
DiffieHellmanGroup dhg = DiffieHellmanGroup.GetGroup(_group, _keySize);
_p = dhg.P;
_g = dhg.G;
_x = ReadPositiveNumber(bR.ReadBuffer());
break;
case DiffieHellmanGroupType.None:
_p = ReadPositiveNumber(bR.ReadBuffer());
_g = ReadPositiveNumber(bR.ReadBuffer());
_x = ReadPositiveNumber(bR.ReadBuffer());
break;
default:
throw new NotSupportedException("DiffieHellmanGroup type not supported.");
}
break;
default:
throw new InvalidDataException("DiffieHellmanPublicKey data format version not supported.");
}
}
VerifyPublicKey(_keySize, _p, _g, _x);
}
public DiffieHellmanPublicKey(byte[] publicKey)
{
using (MemoryStream mS = new MemoryStream(publicKey, false))
{
BincodingDecoder decoder = new BincodingDecoder(mS, "DH");
switch (decoder.Version)
{
case 1:
_keySize = decoder.DecodeNext().GetIntegerValue();
_group = (DiffieHellmanGroupType)decoder.DecodeNext().GetByteValue();
switch (_group)
{
case DiffieHellmanGroupType.RFC3526:
DiffieHellmanGroup dhg = DiffieHellmanGroup.GetGroup(_group, _keySize);
_p = dhg.P;
_g = dhg.G;
_x = ReadPositiveNumber(decoder.DecodeNext().Value);
break;
case DiffieHellmanGroupType.None:
_p = ReadPositiveNumber(decoder.DecodeNext().Value);
_g = ReadPositiveNumber(decoder.DecodeNext().Value);
_x = ReadPositiveNumber(decoder.DecodeNext().Value);
break;
default:
throw new NotSupportedException("DiffieHellmanGroup type not supported.");
}
break;
default:
throw new InvalidDataException("DiffieHellmanPublicKey data format version not supported.");
}
}
VerifyPublicKey(_keySize, _p, _g, _x);
}
public static DiffieHellmanGroup GetGroup(DiffieHellmanGroupType group, int keySize)
{
switch (group)
{
case DiffieHellmanGroupType.RFC3526:
switch (keySize)
{
case 2048:
return(new DiffieHellmanGroup(group, keySize, new BigInteger(p2048), new BigInteger(2)));
case 3072:
return(new DiffieHellmanGroup(group, keySize, new BigInteger(p3072), new BigInteger(2)));
case 4096:
return(new DiffieHellmanGroup(group, keySize, new BigInteger(p4096), new BigInteger(2)));
default:
throw new CryptoException("DiffieHellman key size not supported.");
}
default:
throw new CryptoException("DiffieHellman group not supported.");
}
}