public void TestValidateMacTag()
{
JPakePrimeOrderGroup pg1 = JPakePrimeOrderGroups.SUN_JCE_1024;
SecureRandom random = new SecureRandom();
IDigest digest = new Sha256Digest();
BigInteger x1 = JPakeUtilities.GenerateX1(pg1.Q, random);
BigInteger x2 = JPakeUtilities.GenerateX2(pg1.Q, random);
BigInteger x3 = JPakeUtilities.GenerateX1(pg1.Q, random);
BigInteger x4 = JPakeUtilities.GenerateX2(pg1.Q, random);
BigInteger gx1 = JPakeUtilities.CalculateGx(pg1.P, pg1.G, x1);
BigInteger gx2 = JPakeUtilities.CalculateGx(pg1.P, pg1.G, x2);
BigInteger gx3 = JPakeUtilities.CalculateGx(pg1.P, pg1.G, x3);
BigInteger gx4 = JPakeUtilities.CalculateGx(pg1.P, pg1.G, x4);
BigInteger gB = JPakeUtilities.CalculateGA(pg1.P, gx3, gx1, gx2);
BigInteger s = JPakeUtilities.CalculateS("password".ToCharArray());
BigInteger xs = JPakeUtilities.CalculateX2s(pg1.Q, x4, s);
BigInteger B = JPakeUtilities.CalculateA(pg1.P, pg1.Q, gB, xs);
BigInteger keyingMaterial = JPakeUtilities.CalculateKeyingMaterial(pg1.P, pg1.Q, gx4, x2, s, B);
BigInteger macTag = JPakeUtilities.CalculateMacTag("participantId", "partnerParticipantId", gx1, gx2, gx3, gx4, keyingMaterial, digest);
// should succeed
JPakeUtilities.ValidateMacTag("partnerParticipantId", "participantId", gx3, gx4, gx1, gx2, keyingMaterial, digest, macTag);
// validating own macTag (as opposed to the other party's mactag)
try
{
JPakeUtilities.ValidateMacTag("participantId", "partnerParticipantId", gx1, gx2, gx3, gx4, keyingMaterial, digest, macTag);
Fail("failed to throw exception on validating own macTag (calculated partner macTag)");
}
catch (CryptoException)
{
// expected
}
// participant ids switched
try
{
JPakeUtilities.ValidateMacTag("participantId", "partnerParticipantId", gx3, gx4, gx1, gx2, keyingMaterial, digest, macTag);
Fail("failed to throw exception on validating own macTag (calculated partner macTag");
}
catch (CryptoException)
{
// expected
}
}
public virtual JPakeRound3Payload CreateRound3PayloadToSend(BigInteger keyingMaterial)
{
if (state >= STATE_ROUND_3_CREATED)
{
throw new InvalidOperationException("Round 3 payload already created for " + participantId);
}
if (state < STATE_KEY_CALCULATED)
{
throw new InvalidOperationException("Keying material must be calculated prior to creating round 3 payload for " + participantId);
}
BigInteger magTag = JPakeUtilities.CalculateMacTag(participantId, partnerParticipantId, gx1, gx2, gx3, gx4, keyingMaterial, digest);
state = STATE_ROUND_3_CREATED;
return(new JPakeRound3Payload(participantId, magTag));
}
