/// <summary>
/// Determines whether a named Diffie-Hellman session type and association type can be used together.
/// </summary>
/// <param name="protocol">The protocol carrying the names of the session and association types.</param>
/// <param name="associationType">The value of the openid.assoc_type parameter.</param>
/// <param name="sessionType">The value of the openid.session_type parameter.</param>
/// <returns>
/// <c>true</c> if the named association and session types are compatible; otherwise, <c>false</c>.
/// </returns>
internal static bool IsDHSessionCompatible(Protocol protocol, string associationType, string sessionType)
{
ErrorUtilities.VerifyArgumentNotNull(protocol, "protocol");
ErrorUtilities.VerifyNonZeroLength(associationType, "associationType");
ErrorUtilities.VerifyArgumentNotNull(sessionType, "sessionType");
// All association types can work when no DH session is used at all.
if (string.Equals(sessionType, protocol.Args.SessionType.NoEncryption, StringComparison.Ordinal))
{
return(true);
}
// When there _is_ a DH session, it must match in hash length with the association type.
int associationSecretLengthInBytes = GetSecretLength(protocol, associationType);
int sessionHashLengthInBytes = DiffieHellmanUtilities.Lookup(protocol, sessionType).HashSize / 8;
return(associationSecretLengthInBytes == sessionHashLengthInBytes);
}
/// <summary>
/// Determines whether a named Diffie-Hellman session type and association type can be used together.
/// </summary>
/// <param name="protocol">The protocol carrying the names of the session and association types.</param>
/// <param name="associationType">The value of the openid.assoc_type parameter.</param>
/// <param name="sessionType">The value of the openid.session_type parameter.</param>
/// <returns>
/// <c>true</c> if the named association and session types are compatible; otherwise, <c>false</c>.
/// </returns>
internal static bool IsDHSessionCompatible(Protocol protocol, string associationType, string sessionType)
{
Contract.Requires <ArgumentNullException>(protocol != null);
Contract.Requires <ArgumentException>(!String.IsNullOrEmpty(associationType));
Contract.Requires <ArgumentNullException>(sessionType != null);
// All association types can work when no DH session is used at all.
if (string.Equals(sessionType, protocol.Args.SessionType.NoEncryption, StringComparison.Ordinal))
{
return(true);
}
// When there _is_ a DH session, it must match in hash length with the association type.
int associationSecretLengthInBytes = GetSecretLength(protocol, associationType);
int sessionHashLengthInBytes = DiffieHellmanUtilities.Lookup(protocol, sessionType).HashSize / 8;
return(associationSecretLengthInBytes == sessionHashLengthInBytes);
}
/// <summary>
/// Determines whether a named Diffie-Hellman session type and association type can be used together.
/// </summary>
/// <param name="protocol">The protocol carrying the names of the session and association types.</param>
/// <param name="associationType">The value of the openid.assoc_type parameter.</param>
/// <param name="sessionType">The value of the openid.session_type parameter.</param>
/// <returns>
/// <c>true</c> if the named association and session types are compatible; otherwise, <c>false</c>.
/// </returns>
internal static bool IsDHSessionCompatible(Protocol protocol, string associationType, string sessionType)
{
Requires.NotNull(protocol, "protocol");
Requires.NotNullOrEmpty(associationType, "associationType");
Requires.NotNull(sessionType, "sessionType");
// All association types can work when no DH session is used at all.
if (string.Equals(sessionType, protocol.Args.SessionType.NoEncryption, StringComparison.Ordinal))
{
return(true);
}
if (OpenIdUtilities.IsDiffieHellmanPresent)
{
// When there _is_ a DH session, it must match in hash length with the association type.
int associationSecretLengthInBytes = GetSecretLength(protocol, associationType);
int sessionHashLengthInBytes = DiffieHellmanUtilities.Lookup(protocol, sessionType).HashSize / 8;
return(associationSecretLengthInBytes == sessionHashLengthInBytes);
}
else
{
return(false);
}
}