/// <summary>
/// Constructor for a new JPakeParticipant.
///
/// After construction, the State state will be STATE_INITIALIZED.
///
/// Throws NullReferenceException if any argument is null. Throws
/// ArgumentException if password is empty.
/// </summary>
/// <param name="participantId">Unique identifier of this participant.
/// The two participants in the exchange must NOT share the same id.</param>
/// <param name="password">Shared secret.
/// A defensive copy of this array is made (and cleared once CalculateKeyingMaterial() is called).
/// Caller should clear the input password as soon as possible.</param>
/// <param name="group">Prime order group. See JPakePrimeOrderGroups for standard groups.</param>
/// <param name="digest">Digest to use during zero knowledge proofs and key confirmation
/// (SHA-256 or stronger preferred).</param>
/// <param name="random">Source of secure random data for x1 and x2, and for the zero knowledge proofs.</param>
public JPakeParticipant(string participantId, char[] password, JPakePrimeOrderGroup group, IDigest digest, SecureRandom random)
{
JPakeUtilities.ValidateNotNull(participantId, "participantId");
JPakeUtilities.ValidateNotNull(password, "password");
JPakeUtilities.ValidateNotNull(group, "p");
JPakeUtilities.ValidateNotNull(digest, "digest");
JPakeUtilities.ValidateNotNull(random, "random");
if (password.Length == 0)
{
throw new ArgumentException("Password must not be empty.");
}
this.participantId = participantId;
// Create a defensive copy so as to fully encapsulate the password.
//
// This array will contain the password for the lifetime of this
// participant BEFORE CalculateKeyingMaterial() is called.
//
// i.e. When CalculateKeyingMaterial() is called, the array will be cleared
// in order to remove the password from memory.
//
// The caller is responsible for clearing the original password array
// given as input to this constructor.
this.password = new char[password.Length];
Array.Copy(password, this.password, password.Length);
this.p = group.P;
this.q = group.Q;
this.g = group.G;
this.digest = digest;
this.random = random;
this.state = STATE_INITIALIZED;
}
/// <summary>
/// Convenience constructor for a new JPakeParticipant that uses
/// a SHA-256 digest, and a default SecureRandom implementation.
///
/// After construction, the State state will be STATE_INITIALIZED.
///
/// Throws NullReferenceException if any argument is null. Throws
/// ArgumentException if password is empty.
/// </summary>
/// <param name="participantId">Unique identifier of this participant.
/// The two participants in the exchange must NOT share the same id.</param>
/// <param name="password">Shared secret.
/// A defensive copy of this array is made (and cleared once CalculateKeyingMaterial() is called).
/// Caller should clear the input password as soon as possible.</param>
/// <param name="group">Prime order group. See JPakePrimeOrderGroups for standard groups.</param>
public JPakeParticipant(string participantId, char[] password, JPakePrimeOrderGroup group)
: this(participantId, password, group, new Sha256Digest(), new SecureRandom())
{
}