public static KrbCred WrapTicket(KrbTicket ticket, KrbEncTicketPart encTicketPart)
{
if (ticket is null)
{
throw new ArgumentNullException(nameof(ticket));
}
if (encTicketPart is null)
{
throw new ArgumentNullException(nameof(encTicketPart));
}
KerberosConstants.Now(out DateTimeOffset timestamp, out int usec);
var encPart = new KrbEncKrbCredPart
{
Timestamp = timestamp,
USec = usec,
TicketInfo = new[]
{
new KrbCredInfo
{
Key = encTicketPart.Key,
AuthTime = encTicketPart.AuthTime,
EndTime = encTicketPart.EndTime,
Flags = encTicketPart.Flags,
PName = encTicketPart.CName,
Realm = encTicketPart.CRealm,
RenewTill = encTicketPart.RenewTill,
SName = ticket.SName,
SRealm = ticket.Realm,
StartTime = encTicketPart.StartTime,
}
}
};
var cred = new KrbCred
{
EncryptedPart = new KrbEncryptedData {
Cipher = encPart.EncodeApplication()
},
Tickets = new[] { ticket },
};
return(cred);
}
private static KrbEncTicketPart CreateEncTicketPart(
ServiceTicketRequest request,
KrbAuthorizationData[] authorizationDatas,
KrbEncryptionKey sessionKey)
{
var cname = CreateCNameForTicket(request);
var flags = request.Flags;
if (request.PreAuthenticationData?.Any(r => r.Type == PaDataType.PA_REQ_ENC_PA_REP) ?? false)
{
flags |= TicketFlags.EncryptedPreAuthentication;
}
var addresses = request.Addresses;
if (addresses == null)
{
addresses = Array.Empty <KrbHostAddress>();
}
var encTicketPart = new KrbEncTicketPart()
{
CName = cname,
Key = sessionKey,
AuthTime = request.Now,
StartTime = request.StartTime,
EndTime = request.EndTime,
CRealm = request.RealmName,
Flags = flags,
AuthorizationData = authorizationDatas,
CAddr = addresses.ToArray(),
Transited = new KrbTransitedEncoding()
};
if (flags.HasFlag(TicketFlags.Renewable))
{
// RenewTill should never increase if it was set previously even if this is a renewal pass
encTicketPart.RenewTill = request.RenewTill;
}
return(encTicketPart);
}
public static KrbCred WrapTicket(KrbTicket ticket, KrbEncTicketPart encTicketPart)
{
return(WrapTicket(
ticket,
new KrbCredInfo
{
Key = encTicketPart.Key,
AuthTime = encTicketPart.AuthTime,
EndTime = encTicketPart.EndTime,
Flags = encTicketPart.Flags,
PName = encTicketPart.CName,
Realm = encTicketPart.CRealm,
RenewTill = encTicketPart.RenewTill,
SName = ticket.SName,
SRealm = ticket.Realm,
StartTime = encTicketPart.StartTime,
}
));
}
public static async Task <T> GenerateServiceTicket <T>(ServiceTicketRequest request)
where T : KrbKdcRep, new()
{
var sessionKey = KrbEncryptionKey.Generate(request.ServicePrincipalKey.EncryptionType);
var authz = await GenerateAuthorizationData(request.Principal, request.ServicePrincipalKey);
var cname = KrbPrincipalName.FromPrincipal(request.Principal, realm: request.RealmName);
var flags = request.Flags;
if (request.Principal.SupportedPreAuthenticationTypes.Any())
{
// This is not strictly an accurate way of detecting if the user was pre-authenticated.
// If pre-auth handlers are registered and the principal has PA-Types available, a request
// will never make it to this point without getting authenticated.
//
// However if no pre-auth handlers are registered, then the PA check is skipped
// and this isn't technically accurate anymore.
//
// TODO: this should tie into the make-believe policy check being used in the
// auth handler section
flags |= TicketFlags.EncryptedPreAuthentication | TicketFlags.PreAuthenticated;
}
var addresses = request.Addresses;
if (addresses == null)
{
addresses = new KrbHostAddress[0];
}
var encTicketPart = new KrbEncTicketPart()
{
CName = cname,
Key = sessionKey,
AuthTime = request.Now,
StartTime = request.StartTime,
EndTime = request.EndTime,
CRealm = request.RealmName,
Flags = flags,
AuthorizationData = authz.ToArray(),
CAddr = addresses.ToArray(),
Transited = new KrbTransitedEncoding()
};
if (flags.HasFlag(TicketFlags.Renewable))
{
// RenewTill should never increase if it was set previously even if this is a renewal pass
encTicketPart.RenewTill = request.RenewTill;
}
var ticket = new KrbTicket()
{
Realm = request.RealmName,
SName = KrbPrincipalName.FromPrincipal(
request.ServicePrincipal,
PrincipalNameType.NT_SRV_INST,
request.RealmName
),
EncryptedPart = KrbEncryptedData.Encrypt(
encTicketPart.EncodeApplication(),
request.ServicePrincipalKey,
KeyUsage.Ticket
)
};
KrbEncKdcRepPart encKdcRepPart;
if (typeof(T) == typeof(KrbAsRep))
{
encKdcRepPart = new KrbEncAsRepPart();
}
else if (typeof(T) == typeof(KrbTgsRep))
{
encKdcRepPart = new KrbEncTgsRepPart();
}
else
{
throw new InvalidOperationException($"Requested Service Ticket type is neither KrbAsRep nor KrbTgsRep. Type: {typeof(T)}");
}
encKdcRepPart.AuthTime = encTicketPart.AuthTime;
encKdcRepPart.StartTime = encTicketPart.StartTime;
encKdcRepPart.EndTime = encTicketPart.EndTime;
encKdcRepPart.RenewTill = encTicketPart.RenewTill;
encKdcRepPart.KeyExpiration = request.Principal.Expires;
encKdcRepPart.Realm = request.RealmName;
encKdcRepPart.SName = ticket.SName;
encKdcRepPart.Flags = encTicketPart.Flags;
encKdcRepPart.CAddr = encTicketPart.CAddr;
encKdcRepPart.Key = sessionKey;
encKdcRepPart.Nonce = KerberosConstants.GetNonce();
encKdcRepPart.LastReq = new[] { new KrbLastReq {
Type = 0, Value = request.Now
} };
encKdcRepPart.EncryptedPaData = new KrbMethodData
{
MethodData = new[]
{
new KrbPaData
{
Type = PaDataType.PA_SUPPORTED_ETYPES,
Value = request.Principal.SupportedEncryptionTypes.AsReadOnly(littleEndian: true).AsMemory()
}
}
};
encKdcRepPart.EncodeApplication();
var rep = new T
{
CName = cname,
CRealm = request.RealmName,
MessageType = MessageType.KRB_AS_REP,
Ticket = ticket,
EncPart = KrbEncryptedData.Encrypt(
encKdcRepPart.EncodeApplication(),
request.EncryptedPartKey,
encKdcRepPart.KeyUsage
)
};
return(rep);
}
private static ServiceTicketRequest GenerateServiceTicket <T>(
ServiceTicketRequest request,
out KrbEncTicketPart encTicketPart,
out KrbTicket ticket,
out KrbEncKdcRepPart encKdcRepPart,
out KeyUsage keyUsage,
out MessageType messageType
)
where T : KrbKdcRep, new()
{
if (request.Principal == null)
{
throw new InvalidOperationException("A Principal identity must be provided");
}
if (request.ServicePrincipal == null)
{
throw new InvalidOperationException("A service principal must be provided");
}
if (request.ServicePrincipalKey == null)
{
throw new InvalidOperationException("A service principal key must be provided");
}
var authz = GenerateAuthorizationData(request);
var sessionKey = KrbEncryptionKey.Generate(request.PreferredClientEType ?? request.ServicePrincipalKey.EncryptionType);
encTicketPart = CreateEncTicketPart(request, authz.ToArray(), sessionKey);
bool appendRealm = false;
if (request.ServicePrincipal.PrincipalName.Contains("/"))
{
appendRealm = true;
}
ticket = new KrbTicket()
{
Realm = request.RealmName,
SName = KrbPrincipalName.FromPrincipal(
request.ServicePrincipal,
PrincipalNameType.NT_SRV_INST,
appendRealm ? null : request.RealmName
),
EncryptedPart = KrbEncryptedData.Encrypt(
encTicketPart.EncodeApplication(),
request.ServicePrincipalKey,
KeyUsage.Ticket
)
};
if (typeof(T) == typeof(KrbAsRep))
{
encKdcRepPart = new KrbEncAsRepPart();
keyUsage = KeyUsage.EncAsRepPart;
messageType = MessageType.KRB_AS_REP;
}
else if (typeof(T) == typeof(KrbTgsRep))
{
encKdcRepPart = new KrbEncTgsRepPart();
keyUsage = request.EncryptedPartKey?.Usage ?? KeyUsage.EncTgsRepPartSessionKey;
messageType = MessageType.KRB_TGS_REP;
}
else
{
throw new InvalidOperationException($"Requested Service Ticket type is neither KrbAsRep nor KrbTgsRep. Type: {typeof(T)}");
}
encKdcRepPart.AuthTime = encTicketPart.AuthTime;
encKdcRepPart.StartTime = encTicketPart.StartTime;
encKdcRepPart.EndTime = encTicketPart.EndTime;
encKdcRepPart.RenewTill = encTicketPart.RenewTill;
encKdcRepPart.KeyExpiration = request.Principal.Expires;
encKdcRepPart.Realm = request.RealmName;
encKdcRepPart.SName = ticket.SName;
encKdcRepPart.Flags = encTicketPart.Flags;
encKdcRepPart.CAddr = encTicketPart.CAddr;
encKdcRepPart.Key = sessionKey;
encKdcRepPart.Nonce = request.Nonce;
encKdcRepPart.LastReq = new[] { new KrbLastReq {
Type = 0, Value = request.Now
} };
encKdcRepPart.EncryptedPaData = new KrbMethodData
{
MethodData = new[]
{
new KrbPaData
{
Type = PaDataType.PA_SUPPORTED_ETYPES,
Value = request.Principal.SupportedEncryptionTypes.AsReadOnly(littleEndian: true).AsMemory()
}
}
};
return(request);
}
public static async Task <T> GenerateServiceTicket <T>(ServiceTicketRequest request)
where T : KrbKdcRep, new()
{
if (request.EncryptedPartKey == null)
{
throw new ArgumentException("A session key must be provided to encrypt the response", nameof(request.EncryptedPartKey));
}
if (request.Principal == null)
{
throw new ArgumentException("A Principal identity must be provided", nameof(request.Principal));
}
if (request.ServicePrincipal == null)
{
throw new ArgumentException("A service principal must be provided", nameof(request.ServicePrincipal));
}
if (request.ServicePrincipalKey == null)
{
throw new ArgumentException("A service principal key must be provided", nameof(request.ServicePrincipalKey));
}
var authz = await GenerateAuthorizationData(request.Principal, request);
var cname = KrbPrincipalName.FromPrincipal(request.Principal, realm: request.RealmName);
var sessionKey = KrbEncryptionKey.Generate(request.ServicePrincipalKey.EncryptionType);
var flags = request.Flags;
if (request.PreAuthenticationData?.Any(r => r.Type == PaDataType.PA_REQ_ENC_PA_REP) ?? false)
{
flags |= TicketFlags.EncryptedPreAuthentication;
}
var addresses = request.Addresses;
if (addresses == null)
{
addresses = new KrbHostAddress[0];
}
var encTicketPart = new KrbEncTicketPart()
{
CName = cname,
Key = sessionKey,
AuthTime = request.Now,
StartTime = request.StartTime,
EndTime = request.EndTime,
CRealm = request.RealmName,
Flags = flags,
AuthorizationData = authz.ToArray(),
CAddr = addresses.ToArray(),
Transited = new KrbTransitedEncoding()
};
if (flags.HasFlag(TicketFlags.Renewable))
{
// RenewTill should never increase if it was set previously even if this is a renewal pass
encTicketPart.RenewTill = request.RenewTill;
}
var ticket = new KrbTicket()
{
Realm = request.RealmName,
SName = KrbPrincipalName.FromPrincipal(
request.ServicePrincipal,
PrincipalNameType.NT_SRV_INST,
request.RealmName
),
EncryptedPart = KrbEncryptedData.Encrypt(
encTicketPart.EncodeApplication(),
request.ServicePrincipalKey,
KeyUsage.Ticket
)
};
KrbEncKdcRepPart encKdcRepPart;
if (typeof(T) == typeof(KrbAsRep))
{
encKdcRepPart = new KrbEncAsRepPart();
}
else if (typeof(T) == typeof(KrbTgsRep))
{
encKdcRepPart = new KrbEncTgsRepPart();
}
else
{
throw new InvalidOperationException($"Requested Service Ticket type is neither KrbAsRep nor KrbTgsRep. Type: {typeof(T)}");
}
encKdcRepPart.AuthTime = encTicketPart.AuthTime;
encKdcRepPart.StartTime = encTicketPart.StartTime;
encKdcRepPart.EndTime = encTicketPart.EndTime;
encKdcRepPart.RenewTill = encTicketPart.RenewTill;
encKdcRepPart.KeyExpiration = request.Principal.Expires;
encKdcRepPart.Realm = request.RealmName;
encKdcRepPart.SName = ticket.SName;
encKdcRepPart.Flags = encTicketPart.Flags;
encKdcRepPart.CAddr = encTicketPart.CAddr;
encKdcRepPart.Key = sessionKey;
encKdcRepPart.Nonce = request.Nonce;
encKdcRepPart.LastReq = new[] { new KrbLastReq {
Type = 0, Value = request.Now
} };
encKdcRepPart.EncryptedPaData = new KrbMethodData
{
MethodData = new[]
{
new KrbPaData
{
Type = PaDataType.PA_SUPPORTED_ETYPES,
Value = request.Principal.SupportedEncryptionTypes.AsReadOnly(littleEndian: true).AsMemory()
}
}
};
var rep = new T
{
CName = cname,
CRealm = request.RealmName,
MessageType = MessageType.KRB_AS_REP,
Ticket = ticket,
EncPart = KrbEncryptedData.Encrypt(
encKdcRepPart.EncodeApplication(),
request.EncryptedPartKey,
encKdcRepPart.KeyUsage
)
};
return(rep);
}