/// <summary>
/// Creates and returns the payload to send to the other participant during round 1.
///
/// After execution, the State state} will be STATE_ROUND_1_CREATED}.
/// </summary>
public virtual JPakeRound1Payload CreateRound1PayloadToSend()
{
if (this.state >= STATE_ROUND_1_CREATED)
{
throw new InvalidOperationException("Round 1 payload already created for " + this.participantId);
}
this.x1 = JPakeUtilities.GenerateX1(q, random);
this.x2 = JPakeUtilities.GenerateX2(q, random);
this.gx1 = JPakeUtilities.CalculateGx(p, g, x1);
this.gx2 = JPakeUtilities.CalculateGx(p, g, x2);
BigInteger[] knowledgeProofForX1 = JPakeUtilities.CalculateZeroKnowledgeProof(p, q, g, gx1, x1, participantId, digest, random);
BigInteger[] knowledgeProofForX2 = JPakeUtilities.CalculateZeroKnowledgeProof(p, q, g, gx2, x2, participantId, digest, random);
this.state = STATE_ROUND_1_CREATED;
return(new JPakeRound1Payload(participantId, gx1, gx2, knowledgeProofForX1, knowledgeProofForX2));
}
/// <summary>
/// Creates and returns the payload to send to the other participant during round 2.
///
/// ValidateRound1PayloadReceived(JPakeRound1Payload) must be called prior to this method.
///
/// After execution, the State state will be STATE_ROUND_2_CREATED.
///
/// Throws InvalidOperationException if called prior to ValidateRound1PayloadReceived(JPakeRound1Payload), or multiple times
/// </summary>
public virtual JPakeRound2Payload CreateRound2PayloadToSend()
{
if (this.state >= STATE_ROUND_2_CREATED)
{
throw new InvalidOperationException("Round 2 payload already created for " + this.participantId);
}
if (this.state < STATE_ROUND_1_VALIDATED)
{
throw new InvalidOperationException("Round 1 payload must be validated prior to creating round 2 payload for " + this.participantId);
}
BigInteger gA = JPakeUtilities.CalculateGA(p, gx1, gx3, gx4);
BigInteger s = JPakeUtilities.CalculateS(password);
BigInteger x2s = JPakeUtilities.CalculateX2s(q, x2, s);
BigInteger A = JPakeUtilities.CalculateA(p, q, gA, x2s);
BigInteger[] knowledgeProofForX2s = JPakeUtilities.CalculateZeroKnowledgeProof(p, q, gA, A, x2s, participantId, digest, random);
this.state = STATE_ROUND_2_CREATED;
return(new JPakeRound2Payload(participantId, A, knowledgeProofForX2s));
}