private static KrbApReq CreateApReq(KrbKdcRep kdcRep, KrbEncryptionKey tgtSessionKey)
{
var tgt = kdcRep.Ticket;
KerberosConstants.Now(out DateTimeOffset time, out int usec);
var authenticator = new KrbAuthenticator
{
CName = kdcRep.CName,
CTime = time,
Cusec = usec,
Realm = tgt.Realm,
SequenceNumber = KerberosConstants.GetNonce(),
Subkey = tgtSessionKey,
AuthenticatorVersionNumber = 5
};
var encryptedAuthenticator = KrbEncryptedData.Encrypt(
authenticator.EncodeApplication(),
tgtSessionKey.AsKey(),
KeyUsage.PaTgsReqAuthenticator
);
var apReq = new KrbApReq
{
Ticket = tgt,
Authenticator = encryptedAuthenticator
};
return(apReq);
}
public static T GenerateServiceTicket <T>(ServiceTicketRequest request)
where T : KrbKdcRep, new()
{
if (request.EncryptedPartKey == null)
{
throw new InvalidOperationException("A client key must be provided to encrypt the response");
}
request = GenerateServiceTicket <T>(
request,
out KrbEncTicketPart encTicketPart,
out KrbTicket ticket,
out KrbEncKdcRepPart encKdcRepPart,
out KeyUsage keyUsage,
out MessageType messageType
);
var rep = new T
{
CName = encTicketPart.CName,
CRealm = request.RealmName,
MessageType = messageType,
Ticket = ticket,
EncPart = KrbEncryptedData.Encrypt(
encKdcRepPart.EncodeApplication(),
request.EncryptedPartKey,
keyUsage
)
};
return(rep);
}
private static KrbApReq CreateApReq(KrbKdcRep kdcRep, KrbEncryptionKey tgtSessionKey, KrbChecksum checksum, out KrbEncryptionKey sessionKey)
{
var tgt = kdcRep.Ticket;
var authenticator = new KrbAuthenticator
{
CName = kdcRep.CName,
Realm = kdcRep.CRealm,
SequenceNumber = KerberosConstants.GetNonce(),
Checksum = checksum
};
sessionKey = KrbEncryptionKey.Generate(tgtSessionKey.EType);
sessionKey.Usage = KeyUsage.EncTgsRepPartSubSessionKey;
authenticator.Subkey = sessionKey;
KerberosConstants.Now(out authenticator.CTime, out authenticator.CuSec);
var encryptedAuthenticator = KrbEncryptedData.Encrypt(
authenticator.EncodeApplication(),
tgtSessionKey.AsKey(),
KeyUsage.PaTgsReqAuthenticator
);
var apReq = new KrbApReq
{
Ticket = tgt,
Authenticator = encryptedAuthenticator
};
return(apReq);
}
public static KrbApReq CreateApReq(
KrbKdcRep tgsRep,
KerberosKey authenticatorKey,
ApOptions options,
out KrbAuthenticator authenticator
)
{
var ticket = tgsRep.Ticket;
authenticator = new KrbAuthenticator
{
CName = tgsRep.CName,
Realm = ticket.Realm,
SequenceNumber = KerberosConstants.GetNonce(),
Subkey = KrbEncryptionKey.Generate(authenticatorKey.EncryptionType),
Checksum = KrbChecksum.EncodeDelegationChecksum(new DelegationInfo())
};
KerberosConstants.Now(out authenticator.CTime, out authenticator.CuSec);
var apReq = new KrbApReq
{
Ticket = ticket,
ApOptions = options,
Authenticator = KrbEncryptedData.Encrypt(
authenticator.EncodeApplication(),
authenticatorKey,
KeyUsage.ApReqAuthenticator
)
};
return(apReq);
}
public DateTimeOffset DecryptTimestamp(KerberosKey key, out EncryptionType etype)
{
var timestampPaData = this.PaData.FirstOrDefault(p => p.Type == PaDataType.PA_ENC_TIMESTAMP);
if (timestampPaData == null)
{
etype = EncryptionType.NULL;
return(DateTimeOffset.MinValue);
}
var encryptedTimestamp = KrbEncryptedData.Decode(timestampPaData.Value);
var tsEnc = encryptedTimestamp.Decrypt(key, KeyUsage.PaEncTs, d => KrbPaEncTsEnc.Decode(d));
var timestamp = tsEnc.PaTimestamp;
if (tsEnc.PaUSec > 0)
{
timestamp = timestamp.AddTicks(tsEnc.PaUSec.Value / 10);
}
etype = encryptedTimestamp.EType;
return(timestamp);
}
public static KrbApReq CreateApReq(KrbKdcRep tgsRep, KerberosKey authenticatorKey, ApOptions options)
{
var ticket = tgsRep.Ticket;
KerberosConstants.Now(out DateTimeOffset time, out int usec);
var authenticator = new KrbAuthenticator
{
CName = tgsRep.CName,
CTime = time,
Cusec = usec,
Realm = ticket.Realm,
SequenceNumber = KerberosConstants.GetNonce(),
Subkey = null,
AuthenticatorVersionNumber = 5
};
var apReq = new KrbApReq
{
Ticket = ticket,
ApOptions = options,
Authenticator = KrbEncryptedData.Encrypt(
authenticator.EncodeApplication(),
authenticatorKey,
KeyUsage.ApReqAuthenticator
)
};
return(apReq);
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbApReq, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
if (!explicitReader.TryReadInt32(out decoded.ProtocolVersionNumber))
{
explicitReader.ThrowIfNotEmpty();
}
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
if (!explicitReader.TryReadInt32(out decoded.MessageType))
{
explicitReader.ThrowIfNotEmpty();
}
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
if (explicitReader.TryReadPrimitiveBitStringValue(out _, out ReadOnlyMemory <byte> tmpApOptions))
{
decoded.ApOptions = (ApOptions)tmpApOptions.AsLong();
}
else
{
decoded.ApOptions = (ApOptions)explicitReader.ReadBitString(out _).AsLong();
}
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
KrbTicket.Decode <KrbTicket>(explicitReader, out decoded.Ticket);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out decoded.Authenticator);
explicitReader.ThrowIfNotEmpty();
sequenceReader.ThrowIfNotEmpty();
}
public static KrbApReq CreateApReq(
KrbKdcRep tgsRep,
KerberosKey authenticatorKey,
RequestServiceTicket rst,
out KrbAuthenticator authenticator
)
{
if (tgsRep == null)
{
throw new ArgumentNullException(nameof(tgsRep));
}
if (authenticatorKey == null)
{
throw new ArgumentNullException(nameof(authenticatorKey));
}
var ticket = tgsRep.Ticket;
authenticator = new KrbAuthenticator
{
CName = tgsRep.CName,
Realm = ticket.Realm,
SequenceNumber = KerberosConstants.GetNonce(),
Subkey = KrbEncryptionKey.Generate(authenticatorKey.EncryptionType),
Checksum = KrbChecksum.EncodeDelegationChecksum(new DelegationInfo(rst))
};
KerberosConstants.Now(out DateTimeOffset ctime, out int usec);
authenticator.CTime = ctime;
authenticator.CuSec = usec;
var apReq = new KrbApReq
{
Ticket = ticket,
ApOptions = rst.ApOptions,
Authenticator = KrbEncryptedData.Encrypt(
authenticator.EncodeApplication(),
authenticatorKey,
KeyUsage.ApReqAuthenticator
)
};
return(apReq);
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbTicket, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
if (!explicitReader.TryReadInt32(out int tmpTicketNumber))
{
explicitReader.ThrowIfNotEmpty();
}
decoded.TicketNumber = tmpTicketNumber;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
decoded.Realm = explicitReader.ReadCharacterString(UniversalTagNumber.GeneralString);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
KrbPrincipalName.Decode <KrbPrincipalName>(explicitReader, out KrbPrincipalName tmpSName);
decoded.SName = tmpSName;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out KrbEncryptedData tmpEncryptedPart);
decoded.EncryptedPart = tmpEncryptedPart;
explicitReader.ThrowIfNotEmpty();
sequenceReader.ThrowIfNotEmpty();
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbApRep, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
if (!explicitReader.TryReadInt32(out int tmpProtocolVersionNumber))
{
explicitReader.ThrowIfNotEmpty();
}
decoded.ProtocolVersionNumber = tmpProtocolVersionNumber;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
if (!explicitReader.TryReadInt32(out MessageType tmpMessageType))
{
explicitReader.ThrowIfNotEmpty();
}
decoded.MessageType = tmpMessageType;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out KrbEncryptedData tmpEncryptedPart);
decoded.EncryptedPart = tmpEncryptedPart;
explicitReader.ThrowIfNotEmpty();
sequenceReader.ThrowIfNotEmpty();
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbFastArmoredRep, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out KrbEncryptedData tmpEncFastRep);
decoded.EncFastRep = tmpEncFastRep;
explicitReader.ThrowIfNotEmpty();
sequenceReader.ThrowIfNotEmpty();
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbFastArmoredReq, new()
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
decoded = new T();
AsnReader sequenceReader = reader.ReadSequence(expectedTag);
AsnReader explicitReader;
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 0)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 0));
KrbFastArmor.Decode <KrbFastArmor>(explicitReader, out KrbFastArmor tmpArmor);
decoded.Armor = tmpArmor;
explicitReader.ThrowIfNotEmpty();
}
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
KrbChecksum.Decode <KrbChecksum>(explicitReader, out KrbChecksum tmpRequestChecksum);
decoded.RequestChecksum = tmpRequestChecksum;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out KrbEncryptedData tmpEncryptedFastRequest);
decoded.EncryptedFastRequest = tmpEncryptedFastRequest;
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 sessionKey = KrbEncryptionKey.Generate(request.ServicePrincipalKey.EncryptionType);
var encTicketPart = CreateEncTicketPart(request, authz.ToArray(), sessionKey);
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;
KeyUsage keyUsage;
if (typeof(T) == typeof(KrbAsRep))
{
encKdcRepPart = new KrbEncAsRepPart();
keyUsage = KeyUsage.EncAsRepPart;
}
else if (typeof(T) == typeof(KrbTgsRep))
{
encKdcRepPart = new KrbEncTgsRepPart();
keyUsage = request.EncryptedPartKey.Usage ?? KeyUsage.EncTgsRepPartSessionKey;
}
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 cname = KrbPrincipalName.FromPrincipal(request.Principal, realm: request.RealmName);
var rep = new T
{
CName = cname,
CRealm = request.RealmName,
MessageType = MessageType.KRB_AS_REP,
Ticket = ticket,
EncPart = KrbEncryptedData.Encrypt(
encKdcRepPart.EncodeApplication(),
request.EncryptedPartKey,
keyUsage
)
};
return(rep);
}
public static KrbAsReq CreateAsReq(KerberosCredential credential, AuthenticationOptions options)
{
var kdcOptions = (KdcOptions)(options & ~AuthenticationOptions.AllAuthentication);
var hostAddress = Environment.MachineName;
var padata = new List <KrbPaData>()
{
new KrbPaData
{
Type = PaDataType.PA_PAC_REQUEST,
Value = new KrbPaPacRequest
{
IncludePac = options.HasFlag(AuthenticationOptions.IncludePacRequest)
}.Encode().AsMemory()
}
};
if (options.HasFlag(AuthenticationOptions.PreAuthenticate))
{
KerberosConstants.Now(out DateTimeOffset timestamp, out int usec);
var ts = new KrbPaEncTsEnc
{
PaTimestamp = timestamp,
PaUSec = usec
};
var tsEncoded = ts.Encode().AsMemory();
KrbEncryptedData encData = KrbEncryptedData.Encrypt(
tsEncoded,
credential.CreateKey(),
KeyUsage.PaEncTs
);
padata.Add(new KrbPaData
{
Type = PaDataType.PA_ENC_TIMESTAMP,
Value = encData.Encode().AsMemory()
});
}
var asreq = new KrbAsReq()
{
MessageType = MessageType.KRB_AS_REQ,
Body = new KrbKdcReqBody
{
Addresses = new[] {
new KrbHostAddress {
AddressType = AddressType.NetBios,
Address = Encoding.ASCII.GetBytes(hostAddress.PadRight(16, ' '))
}
},
CName = new KrbPrincipalName
{
Name = new[] { $"{credential.UserName}@{credential.Domain}" },
Type = PrincipalNameType.NT_ENTERPRISE
},
EType = KerberosConstants.ETypes.ToArray(),
KdcOptions = kdcOptions,
Nonce = KerberosConstants.GetNonce(),
RTime = KerberosConstants.EndOfTime,
Realm = credential.Domain,
SName = new KrbPrincipalName
{
Type = PrincipalNameType.NT_SRV_INST,
Name = new[] { "krbtgt", credential.Domain }
},
Till = KerberosConstants.EndOfTime
},
PaData = padata.ToArray()
};
return(asreq);
}
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);
}
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);
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbKdcRep, 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.TryReadInt32(out decoded.ProtocolVersionNumber))
{
explicitReader.ThrowIfNotEmpty();
}
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
if (!explicitReader.TryReadInt32(out decoded.MessageType))
{
explicitReader.ThrowIfNotEmpty();
}
explicitReader.ThrowIfNotEmpty();
if (sequenceReader.HasData && sequenceReader.PeekTag().HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 2)))
{
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
// Decode SEQUENCE OF for PaData
{
collectionReader = explicitReader.ReadSequence();
var tmpList = new List <KrbPaData>();
KrbPaData tmpItem;
while (collectionReader.HasData)
{
KrbPaData.Decode <KrbPaData>(collectionReader, out tmpItem);
tmpList.Add(tmpItem);
}
decoded.PaData = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
}
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
decoded.CRealm = explicitReader.ReadCharacterString(UniversalTagNumber.GeneralString);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 4));
KrbPrincipalName.Decode <KrbPrincipalName>(explicitReader, out decoded.CName);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 5));
KrbTicket.Decode <KrbTicket>(explicitReader, out decoded.Ticket);
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 6));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out decoded.EncPart);
explicitReader.ThrowIfNotEmpty();
sequenceReader.ThrowIfNotEmpty();
}
internal static void Decode <T>(AsnReader reader, Asn1Tag expectedTag, out T decoded)
where T : KrbCred, 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.TryReadInt32(out int tmpProtocolVersionNumber))
{
explicitReader.ThrowIfNotEmpty();
}
decoded.ProtocolVersionNumber = tmpProtocolVersionNumber;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 1));
if (!explicitReader.TryReadInt32(out MessageType tmpMessageType))
{
explicitReader.ThrowIfNotEmpty();
}
decoded.MessageType = tmpMessageType;
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 2));
// Decode SEQUENCE OF for Tickets
{
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.Tickets = tmpList.ToArray();
}
explicitReader.ThrowIfNotEmpty();
explicitReader = sequenceReader.ReadSequence(new Asn1Tag(TagClass.ContextSpecific, 3));
KrbEncryptedData.Decode <KrbEncryptedData>(explicitReader, out KrbEncryptedData tmpEncryptedPart);
decoded.EncryptedPart = tmpEncryptedPart;
explicitReader.ThrowIfNotEmpty();
sequenceReader.ThrowIfNotEmpty();
}
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();
}
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 KrbApReq CreateApReq(
KrbKdcRep tgsRep,
KerberosKey authenticatorKey,
RequestServiceTicket rst,
out KrbAuthenticator authenticator
)
{
if (tgsRep == null)
{
throw new ArgumentNullException(nameof(tgsRep));
}
if (authenticatorKey == null)
{
throw new ArgumentNullException(nameof(authenticatorKey));
}
authenticator = new KrbAuthenticator
{
CName = tgsRep.CName,
Realm = tgsRep.CRealm
};
if (rst.AuthenticatorChecksum != null)
{
authenticator.Checksum = rst.AuthenticatorChecksum;
}
else if (!rst.AuthenticatorChecksumSource.IsEmpty)
{
authenticator.Checksum = KrbChecksum.Create(
rst.AuthenticatorChecksumSource,
authenticatorKey,
KeyUsage.AuthenticatorChecksum
);
}
else if (rst.GssContextFlags != GssContextEstablishmentFlag.GSS_C_NONE)
{
authenticator.Checksum = KrbChecksum.EncodeDelegationChecksum(new DelegationInfo(rst));
}
if (rst.IncludeSequenceNumber ?? true)
{
authenticator.SequenceNumber = GetNonce();
}
if (rst.ApOptions.HasFlag(ApOptions.MutualRequired))
{
authenticator.Subkey = KrbEncryptionKey.Generate(authenticatorKey.EncryptionType);
}
Now(out DateTimeOffset ctime, out int usec);
authenticator.CTime = ctime;
authenticator.CuSec = usec;
var apReq = new KrbApReq
{
Ticket = tgsRep.Ticket,
ApOptions = rst.ApOptions,
Authenticator = KrbEncryptedData.Encrypt(
authenticator.EncodeApplication(),
authenticatorKey,
KeyUsage.ApReqAuthenticator
)
};
return(apReq);
}
