private static KrbHostAddress[] IncludeAddresses(Krb5Config config)
{
if (config.Defaults.NoAddresses)
{
return(null);
}
var addresses = new List <KrbHostAddress>
{
KrbHostAddress.ParseAddress(Environment.MachineName.PadRight(16, ' '))
};
if (config.Defaults?.ExtraAddresses?.Any() ?? false)
{
addresses.AddRange(config.Defaults.ExtraAddresses.Select(a => KrbHostAddress.ParseAddress(a)));
}
return(addresses.ToArray());
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbEncTicketPart, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
AsnReader collectionReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
if (explicitReader.TryReadPrimitiveBitStringValue(out _, out ReadOnlyMemory <byte> tmpFlags))
{
decoded.Flags = (TicketFlags)tmpFlags.AsLong();
}
else
{
decoded.Flags = (TicketFlags)explicitReader.ReadBitString(out _).AsLong();
}
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
KrbEncryptionKey.Decode <KrbEncryptionKey>(explicitReader, out decoded.Key);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
decoded.CRealm = explicitReader.ReadCharacterString(UniversalTagNumber.GeneralString);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
KrbPrincipalName.Decode <KrbPrincipalName>(explicitReader, out decoded.CName);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
KrbTransitedEncoding.Decode <KrbTransitedEncoding>(explicitReader, out decoded.Transited);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 5));
decoded.AuthTime = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 6)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 6));
decoded.StartTime = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
}
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 7));
decoded.EndTime = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 8)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 8));
decoded.RenewTill = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 9)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 9));
// Decode SEQUENCE OF for CAddr
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <KrbHostAddress>();
KrbHostAddress tmpItem;
while (collectionReader.HasData)
{
KrbHostAddress.Decode <KrbHostAddress>(collectionReader, out tmpItem);
tmpList.Add(tmpItem);
}
decoded.CAddr = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 10)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 10));
// Decode SEQUENCE OF for AuthorizationData
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <KrbAuthorizationData>();
KrbAuthorizationData tmpItem;
while (collectionReader.HasData)
{
KrbAuthorizationData.Decode <KrbAuthorizationData>(collectionReader, out tmpItem);
tmpList.Add(tmpItem);
}
decoded.AuthorizationData = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
}
sequenceReader.ThrowIfNotEmpty();
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbEncKrbCredPart, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
AsnReader collectionReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
// Decode SEQUENCE OF for TicketInfo
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <KrbCredInfo>();
KrbCredInfo tmpItem;
while (collectionReader.HasData)
{
KrbCredInfo.Decode <KrbCredInfo>(collectionReader, out KrbCredInfo tmp);
tmpItem = tmp;
tmpList.Add(tmpItem);
}
decoded.TicketInfo = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 1)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
if (explicitReader.TryReadInt32(out int tmpNonce))
{
decoded.Nonce = tmpNonce;
}
else
{
explicitReader.ThrowIfNotEmpty();
}
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 2)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
decoded.Timestamp = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 3)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
if (explicitReader.TryReadInt32(out int tmpUSec))
{
decoded.USec = tmpUSec;
}
else
{
explicitReader.ThrowIfNotEmpty();
}
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 4)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
KrbHostAddress.Decode <KrbHostAddress>(explicitReader, out KrbHostAddress tmpSAddress);
decoded.SAddress = tmpSAddress;
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 5)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 5));
KrbHostAddress.Decode <KrbHostAddress>(explicitReader, out KrbHostAddress tmpRAddress);
decoded.RAddress = tmpRAddress;
explicitReader.ThrowIfNotEmpty();
}
sequenceReader.ThrowIfNotEmpty();
}
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);
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbKdcReqBody, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
AsnReader collectionReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
if (explicitReader.TryReadPrimitiveBitStringValue(out _, out ReadOnlyMemory <byte> tmpKdcOptions))
{
decoded.KdcOptions = (KdcOptions)tmpKdcOptions.AsLong();
}
else
{
decoded.KdcOptions = (KdcOptions)explicitReader.ReadBitString(out _).AsLong();
}
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 1)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
KrbPrincipalName.Decode <KrbPrincipalName>(explicitReader, out KrbPrincipalName tmpCName);
decoded.CName = tmpCName;
explicitReader.ThrowIfNotEmpty();
}
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
decoded.Realm = explicitReader.ReadCharacterString(UniversalTagNumber.GeneralString);
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 3)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
KrbPrincipalName.Decode <KrbPrincipalName>(explicitReader, out KrbPrincipalName tmpSName);
decoded.SName = tmpSName;
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 4)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
decoded.From = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
}
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 5));
decoded.Till = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 6)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 6));
decoded.RTime = explicitReader.ReadGeneralizedTime();
explicitReader.ThrowIfNotEmpty();
}
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 7));
if (!explicitReader.TryReadInt32(out int tmpNonce))
{
explicitReader.ThrowIfNotEmpty();
}
decoded.Nonce = tmpNonce;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 8));
// Decode SEQUENCE OF for EType
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <EncryptionType>();
EncryptionType tmpItem;
while (collectionReader.HasData)
{
if (!collectionReader.TryReadInt32(out EncryptionType tmp))
{
collectionReader.ThrowIfNotEmpty();
}
tmpItem = tmp;
tmpList.Add(tmpItem);
}
decoded.EType = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 9)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 9));
// Decode SEQUENCE OF for Addresses
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <KrbHostAddress>();
KrbHostAddress tmpItem;
while (collectionReader.HasData)
{
KrbHostAddress.Decode <KrbHostAddress>(collectionReader, out KrbHostAddress tmp);
tmpItem = tmp;
tmpList.Add(tmpItem);
}
decoded.Addresses = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 10)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 10));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out KrbEncryptedData tmpEncAuthorizationData);
decoded.EncAuthorizationData = tmpEncAuthorizationData;
explicitReader.ThrowIfNotEmpty();
}
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 11)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 11));
// Decode SEQUENCE OF for AdditionalTickets
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <KrbTicket>();
KrbTicket tmpItem;
while (collectionReader.HasData)
{
KrbTicket.Decode <KrbTicket>(collectionReader, out KrbTicket tmp);
tmpItem = tmp;
tmpList.Add(tmpItem);
}
decoded.AdditionalTickets = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
}
sequenceReader.ThrowIfNotEmpty();
}
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);
}
