/// <summary>
/// Validates the payload received from the other participant during round 3.
///
/// See JPakeParticipant for more details on round 3.
///
/// After execution, the State state will be STATE_ROUND_3_VALIDATED.
///
/// Throws CryptoException if validation fails. Throws InvalidOperationException if called prior to
/// CalculateKeyingMaterial or multiple times
/// </summary>
/// <param name="round3PayloadReceived">The round 3 payload received from the other participant.</param>
/// <param name="keyingMaterial">The keying material as returned from CalculateKeyingMaterial().</param>
public virtual void ValidateRound3PayloadReceived(JPakeRound3Payload round3PayloadReceived, BigInteger keyingMaterial)
{
if (this.state >= STATE_ROUND_3_VALIDATED)
{
throw new InvalidOperationException("Validation already attempted for round 3 payload for " + this.participantId);
}
if (this.state < STATE_KEY_CALCULATED)
{
throw new InvalidOperationException("Keying material must be calculated prior to validating round 3 payload for " + this.participantId);
}
JPakeUtilities.ValidateParticipantIdsDiffer(participantId, round3PayloadReceived.ParticipantId);
JPakeUtilities.ValidateParticipantIdsEqual(this.partnerParticipantId, round3PayloadReceived.ParticipantId);
JPakeUtilities.ValidateMacTag(
this.participantId,
this.partnerParticipantId,
this.gx1,
this.gx2,
this.gx3,
this.gx4,
keyingMaterial,
this.digest,
round3PayloadReceived.MacTag);
// Clear the rest of the fields.
this.gx1 = null;
this.gx2 = null;
this.gx3 = null;
this.gx4 = null;
this.state = STATE_ROUND_3_VALIDATED;
}
/// <summary>
/// Validates the payload received from the other participant during round 1.
///
/// Must be called prior to CreateRound2PayloadToSend().
///
/// After execution, the State state will be STATE_ROUND_1_VALIDATED.
///
/// Throws CryptoException if validation fails. Throws InvalidOperationException
/// if called multiple times.
/// </summary>
public virtual void ValidateRound1PayloadReceived(JPakeRound1Payload round1PayloadReceived)
{
if (this.state >= STATE_ROUND_1_VALIDATED)
{
throw new InvalidOperationException("Validation already attempted for round 1 payload for " + this.participantId);
}
this.partnerParticipantId = round1PayloadReceived.ParticipantId;
this.gx3 = round1PayloadReceived.Gx1;
this.gx4 = round1PayloadReceived.Gx2;
BigInteger[] knowledgeProofForX3 = round1PayloadReceived.KnowledgeProofForX1;
BigInteger[] knowledgeProofForX4 = round1PayloadReceived.KnowledgeProofForX2;
JPakeUtilities.ValidateParticipantIdsDiffer(participantId, round1PayloadReceived.ParticipantId);
JPakeUtilities.ValidateGx4(gx4);
JPakeUtilities.ValidateZeroKnowledgeProof(p, q, g, gx3, knowledgeProofForX3, round1PayloadReceived.ParticipantId, digest);
JPakeUtilities.ValidateZeroKnowledgeProof(p, q, g, gx4, knowledgeProofForX4, round1PayloadReceived.ParticipantId, digest);
this.state = STATE_ROUND_1_VALIDATED;
}
/// <summary>
/// Validates the payload received from the other participant during round 2.
/// Note that this DOES NOT detect a non-common password.
/// The only indication of a non-common password is through derivation
/// of different keys (which can be detected explicitly by executing round 3 and round 4)
///
/// Must be called prior to CalculateKeyingMaterial().
///
/// After execution, the State state will be STATE_ROUND_2_VALIDATED.
///
/// Throws CryptoException if validation fails. Throws
/// InvalidOperationException if called prior to ValidateRound1PayloadReceived(JPakeRound1Payload), or multiple times
/// </summary>
public virtual void ValidateRound2PayloadReceived(JPakeRound2Payload round2PayloadReceived)
{
if (this.state >= STATE_ROUND_2_VALIDATED)
{
throw new InvalidOperationException("Validation already attempted for round 2 payload for " + this.participantId);
}
if (this.state < STATE_ROUND_1_VALIDATED)
{
throw new InvalidOperationException("Round 1 payload must be validated prior to validation round 2 payload for " + this.participantId);
}
BigInteger gB = JPakeUtilities.CalculateGA(p, gx3, gx1, gx2);
this.b = round2PayloadReceived.A;
BigInteger[] knowledgeProofForX4s = round2PayloadReceived.KnowledgeProofForX2s;
JPakeUtilities.ValidateParticipantIdsDiffer(participantId, round2PayloadReceived.ParticipantId);
JPakeUtilities.ValidateParticipantIdsEqual(this.partnerParticipantId, round2PayloadReceived.ParticipantId);
JPakeUtilities.ValidateGa(gB);
JPakeUtilities.ValidateZeroKnowledgeProof(p, q, gB, b, knowledgeProofForX4s, round2PayloadReceived.ParticipantId, digest);
this.state = STATE_ROUND_2_VALIDATED;
}