SimulatedTlsSrpIdentityManager
An implementation of TlsSrpIdentityManager that simulates the existence of "unknown"
identities to obscure the fact that there is no verifier for them.
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Tls.Crypto;
using Org.BouncyCastle.Utilities;
namespace Org.BouncyCastle.Tls
{
public class SimulatedTlsSrpIdentityManager : TlsSrpIdentityManager
{
private static readonly byte[] PrefixPassword = Strings.ToByteArray("password");
private static readonly byte[] PrefixSalt = Strings.ToByteArray("salt");
protected readonly Srp6Group m_group;
protected readonly TlsSrp6VerifierGenerator m_verifierGenerator;
protected readonly TlsMac m_mac;
public static SimulatedTlsSrpIdentityManager GetRfc5054Default(TlsCrypto crypto, Srp6Group group, byte[] seedKey)
{
TlsMac tlsMac = crypto.CreateHmac(2);
tlsMac.SetKey(seedKey, 0, seedKey.Length);
TlsSrpConfig tlsSrpConfig = new TlsSrpConfig();
tlsSrpConfig.SetExplicitNG(new BigInteger[2] {
group.N,
group.G
});
return new SimulatedTlsSrpIdentityManager(group, crypto.CreateSrp6VerifierGenerator(tlsSrpConfig), tlsMac);
}
public SimulatedTlsSrpIdentityManager(Srp6Group group, TlsSrp6VerifierGenerator verifierGenerator, TlsMac mac)
{
m_group = group;
m_verifierGenerator = verifierGenerator;
m_mac = mac;
}
public virtual TlsSrpLoginParameters GetLoginParameters(byte[] identity)
{
m_mac.Update(PrefixSalt, 0, PrefixSalt.Length);
m_mac.Update(identity, 0, identity.Length);
byte[] salt = m_mac.CalculateMac();
m_mac.Update(PrefixPassword, 0, PrefixPassword.Length);
m_mac.Update(identity, 0, identity.Length);
byte[] password = m_mac.CalculateMac();
BigInteger verifier = m_verifierGenerator.GenerateVerifier(salt, identity, password);
TlsSrpConfig tlsSrpConfig = new TlsSrpConfig();
tlsSrpConfig.SetExplicitNG(new BigInteger[2] {
m_group.N,
m_group.G
});
return new TlsSrpLoginParameters(identity, tlsSrpConfig, verifier, salt);
}
}
}