Files
rdpy/rdpy/protocol/rdp/gcc.py

612 lines
22 KiB
Python

#
# Copyright (c) 2014 Sylvain Peyrefitte
#
# This file is part of rdpy.
#
# rdpy is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
#
"""
Implement GCC structure use in RDP protocol
http://msdn.microsoft.com/en-us/library/cc240508.aspx
"""
import md5
from rdpy.core.type import UInt8, UInt16Le, UInt32Le, CompositeType, String, Stream, sizeof, FactoryType, ArrayType
import per, mcs
from rdpy.core.error import InvalidExpectedDataException
from rdpy.core import log
from rdpy.security import x509
import rdpy.security.rsa_wrapper as rsa
t124_02_98_oid = ( 0, 0, 20, 124, 0, 1 )
h221_cs_key = "Duca";
h221_sc_key = "McDn";
class MessageType(object):
"""
@summary: Server to Client block
GCC conference messages
@see: http://msdn.microsoft.com/en-us/library/cc240509.aspx
"""
#server -> client
SC_CORE = 0x0C01
SC_SECURITY = 0x0C02
SC_NET = 0x0C03
#client -> server
CS_CORE = 0xC001
CS_SECURITY = 0xC002
CS_NET = 0xC003
CS_CLUSTER = 0xC004
CS_MONITOR = 0xC005
class ColorDepth(object):
"""
@summary: Depth color
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
RNS_UD_COLOR_8BPP = 0xCA01
RNS_UD_COLOR_16BPP_555 = 0xCA02
RNS_UD_COLOR_16BPP_565 = 0xCA03
RNS_UD_COLOR_24BPP = 0xCA04
class HighColor(object):
"""
@summary: High color of client
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
HIGH_COLOR_4BPP = 0x0004
HIGH_COLOR_8BPP = 0x0008
HIGH_COLOR_15BPP = 0x000f
HIGH_COLOR_16BPP = 0x0010
HIGH_COLOR_24BPP = 0x0018
class Support(object):
"""
@summary: Supported depth flag
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
RNS_UD_24BPP_SUPPORT = 0x0001
RNS_UD_16BPP_SUPPORT = 0x0002
RNS_UD_15BPP_SUPPORT = 0x0004
RNS_UD_32BPP_SUPPORT = 0x0008
class CapabilityFlags(object):
"""
@summary: For more details on each flags click above
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
RNS_UD_CS_SUPPORT_ERRINFO_PDU = 0x0001
RNS_UD_CS_WANT_32BPP_SESSION = 0x0002
RNS_UD_CS_SUPPORT_STATUSINFO_PDU = 0x0004
RNS_UD_CS_STRONG_ASYMMETRIC_KEYS = 0x0008
RNS_UD_CS_UNUSED = 0x0010
RNS_UD_CS_VALID_CONNECTION_TYPE = 0x0020
RNS_UD_CS_SUPPORT_MONITOR_LAYOUT_PDU = 0x0040
RNS_UD_CS_SUPPORT_NETCHAR_AUTODETECT = 0x0080
RNS_UD_CS_SUPPORT_DYNVC_GFX_PROTOCOL = 0x0100
RNS_UD_CS_SUPPORT_DYNAMIC_TIME_ZONE = 0x0200
RNS_UD_CS_SUPPORT_HEARTBEAT_PDU = 0x0400
class ConnectionType(object):
"""
@summary: This information is correct if
RNS_UD_CS_VALID_CONNECTION_TYPE flag is set on capabilityFlag
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
CONNECTION_TYPE_MODEM = 0x01
CONNECTION_TYPE_BROADBAND_LOW = 0x02
CONNECTION_TYPE_SATELLITE = 0x03
CONNECTION_TYPE_BROADBAND_HIGH = 0x04
CONNECTION_TYPE_WAN = 0x05
CONNECTION_TYPE_LAN = 0x06
CONNECTION_TYPE_AUTODETECT = 0x07
class Version(object):
"""
@summary: Supported version of RDP
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
RDP_VERSION_4 = 0x00080001
RDP_VERSION_5_PLUS = 0x00080004
class Sequence(object):
RNS_UD_SAS_DEL = 0xAA03
class EncryptionMethod(object):
"""
@summary: Encryption methods supported
@see: http://msdn.microsoft.com/en-us/library/cc240511.aspx
"""
ENCRYPTION_FLAG_40BIT = 0x00000001
ENCRYPTION_FLAG_128BIT = 0x00000002
ENCRYPTION_FLAG_56BIT = 0x00000008
FIPS_ENCRYPTION_FLAG = 0x00000010
class EncryptionLevel(object):
"""
@summary: level of 'security'
@see: http://msdn.microsoft.com/en-us/library/cc240518.aspx
"""
ENCRYPTION_LEVEL_NONE = 0x00000000
ENCRYPTION_LEVEL_LOW = 0x00000001
ENCRYPTION_LEVEL_CLIENT_COMPATIBLE = 0x00000002
ENCRYPTION_LEVEL_HIGH = 0x00000003
ENCRYPTION_LEVEL_FIPS = 0x00000004
class ChannelOptions(object):
"""
@summary: Channel options
@see: http://msdn.microsoft.com/en-us/library/cc240513.aspx
"""
CHANNEL_OPTION_INITIALIZED = 0x80000000
CHANNEL_OPTION_ENCRYPT_RDP = 0x40000000
CHANNEL_OPTION_ENCRYPT_SC = 0x20000000
CHANNEL_OPTION_ENCRYPT_CS = 0x10000000
CHANNEL_OPTION_PRI_HIGH = 0x08000000
CHANNEL_OPTION_PRI_MED = 0x04000000
CHANNEL_OPTION_PRI_LOW = 0x02000000
CHANNEL_OPTION_COMPRESS_RDP = 0x00800000
CHANNEL_OPTION_COMPRESS = 0x00400000
CHANNEL_OPTION_SHOW_PROTOCOL = 0x00200000
REMOTE_CONTROL_PERSISTENT = 0x00100000
class KeyboardType(object):
"""
@summary: Keyboard type
@see: IBM_101_102_KEYS is the most common keyboard type
"""
IBM_PC_XT_83_KEY = 0x00000001
OLIVETTI = 0x00000002
IBM_PC_AT_84_KEY = 0x00000003
IBM_101_102_KEYS = 0x00000004
NOKIA_1050 = 0x00000005
NOKIA_9140 = 0x00000006
JAPANESE = 0x00000007
class KeyboardLayout(object):
"""
@summary: Keyboard layout definition
@see: http://technet.microsoft.com/en-us/library/cc766503%28WS.10%29.aspx
"""
ARABIC = 0x00000401
BULGARIAN = 0x00000402
CHINESE_US_KEYBOARD = 0x00000404
CZECH = 0x00000405
DANISH = 0x00000406
GERMAN = 0x00000407
GREEK = 0x00000408
US = 0x00000409
SPANISH = 0x0000040a
FINNISH = 0x0000040b
FRENCH = 0x0000040c
HEBREW = 0x0000040d
HUNGARIAN = 0x0000040e
ICELANDIC = 0x0000040f
ITALIAN = 0x00000410
JAPANESE = 0x00000411
KOREAN = 0x00000412
DUTCH = 0x00000413
NORWEGIAN = 0x00000414
class CertificateType(object):
"""
@see: http://msdn.microsoft.com/en-us/library/cc240521.aspx
"""
CERT_CHAIN_VERSION_1 = 0x00000001
CERT_CHAIN_VERSION_2 = 0x00000002
class DataBlock(CompositeType):
"""
@summary: Block settings
"""
def __init__(self, dataBlock = None):
CompositeType.__init__(self)
self.type = UInt16Le(lambda:self.dataBlock.__class__._TYPE_)
self.length = UInt16Le(lambda:sizeof(self))
def DataBlockFactory():
"""
@summary: build settings in accordance of type self.type.value
"""
for c in [ClientCoreData, ClientSecurityData, ClientNetworkData, ServerCoreData, ServerNetworkData, ServerSecurityData]:
if self.type.value == c._TYPE_:
return c(readLen = self.length - 4)
log.debug("unknown GCC block type : %s"%hex(self.type.value))
#read entire packet
return String(readLen = self.length - 4)
if dataBlock is None:
dataBlock = FactoryType(DataBlockFactory)
elif not "_TYPE_" in dataBlock.__class__.__dict__:
raise InvalidExpectedDataException("Try to send an invalid GCC blocks")
self.dataBlock = dataBlock
class ClientCoreData(CompositeType):
"""
@summary: Class that represent core setting of client
@see: http://msdn.microsoft.com/en-us/library/cc240510.aspx
"""
_TYPE_ = MessageType.CS_CORE
def __init__(self, readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.rdpVersion = UInt32Le(Version.RDP_VERSION_5_PLUS)
self.desktopWidth = UInt16Le(1280)
self.desktopHeight = UInt16Le(800)
self.colorDepth = UInt16Le(ColorDepth.RNS_UD_COLOR_8BPP)
self.sasSequence = UInt16Le(Sequence.RNS_UD_SAS_DEL)
self.kbdLayout = UInt32Le(KeyboardLayout.US)
self.clientBuild = UInt32Le(3790)
self.clientName = String("rdpy" + "\x00"*11, readLen = UInt8(32), unicode = True)
self.keyboardType = UInt32Le(KeyboardType.IBM_101_102_KEYS)
self.keyboardSubType = UInt32Le(0)
self.keyboardFnKeys = UInt32Le(12)
self.imeFileName = String("\x00"*64, readLen = UInt8(64))
self.postBeta2ColorDepth = UInt16Le(ColorDepth.RNS_UD_COLOR_8BPP)
self.clientProductId = UInt16Le(1)
self.serialNumber = UInt32Le(0)
self.highColorDepth = UInt16Le(HighColor.HIGH_COLOR_24BPP)
self.supportedColorDepths = UInt16Le(Support.RNS_UD_15BPP_SUPPORT | Support.RNS_UD_16BPP_SUPPORT | Support.RNS_UD_24BPP_SUPPORT | Support.RNS_UD_32BPP_SUPPORT)
self.earlyCapabilityFlags = UInt16Le(CapabilityFlags.RNS_UD_CS_SUPPORT_ERRINFO_PDU)
self.clientDigProductId = String("\x00"*64, readLen = UInt8(64))
self.connectionType = UInt8()
self.pad1octet = UInt8()
self.serverSelectedProtocol = UInt32Le()
class ServerCoreData(CompositeType):
"""
@summary: Server side core settings structure
@see: http://msdn.microsoft.com/en-us/library/cc240517.aspx
"""
_TYPE_ = MessageType.SC_CORE
def __init__(self, readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.rdpVersion = UInt32Le(Version.RDP_VERSION_5_PLUS)
self.clientRequestedProtocol = UInt32Le()
class ClientSecurityData(CompositeType):
"""
@summary: Client security setting
@see: http://msdn.microsoft.com/en-us/library/cc240511.aspx
"""
_TYPE_ = MessageType.CS_SECURITY
def __init__(self, readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.encryptionMethods = UInt32Le(EncryptionMethod.ENCRYPTION_FLAG_40BIT | EncryptionMethod.ENCRYPTION_FLAG_56BIT | EncryptionMethod.ENCRYPTION_FLAG_128BIT)
self.extEncryptionMethods = UInt32Le()
class ServerSecurityData(CompositeType):
"""
@summary: Server security settings
@see: http://msdn.microsoft.com/en-us/library/cc240518.aspx
"""
_TYPE_ = MessageType.SC_SECURITY
def __init__(self, readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.encryptionMethod = UInt32Le()
self.encryptionLevel = UInt32Le()
self.serverRandomLen = UInt32Le(0x00000020, constant = True, conditional = lambda:not(self.encryptionMethod.value == 0 and self.encryptionLevel == 0))
self.serverCertLen = UInt32Le(lambda:sizeof(self.serverCertificate), conditional = lambda:not(self.encryptionMethod.value == 0 and self.encryptionLevel == 0))
self.serverRandom = String(readLen = self.serverRandomLen, conditional = lambda:not(self.encryptionMethod.value == 0 and self.encryptionLevel == 0))
self.serverCertificate = ServerCertificate(readLen = self.serverCertLen, conditional = lambda:not(self.encryptionMethod.value == 0 and self.encryptionLevel == 0))
class ServerCertificate(CompositeType):
"""
@summary: Server certificate structure
@see: http://msdn.microsoft.com/en-us/library/cc240521.aspx
"""
def __init__(self, certData = None, readLen = None, conditional = lambda:True):
CompositeType.__init__(self, readLen = readLen, conditional = conditional)
self.dwVersion = UInt32Le(lambda:(self.certData.__class__._TYPE_))
def CertificateFactory():
"""
Closure for capability factory
"""
for c in [ProprietaryServerCertificate, X509CertificateChain]:
if self.dwVersion.value & 0x7fffffff == c._TYPE_:
return c()
raise InvalidExpectedDataException("unknown certificate type : %s "%hex(self.dwVersion.value))
if certData is None:
certData = FactoryType(CertificateFactory)
elif not "_TYPE_" in certData.__class__.__dict__:
raise InvalidExpectedDataException("Try to send an invalid Certificate")
self.certData = certData
class ProprietaryServerCertificate(CompositeType):
"""
@summary: microsoft proprietary certificate
@see: http://msdn.microsoft.com/en-us/library/cc240519.aspx
"""
_TYPE_ = CertificateType.CERT_CHAIN_VERSION_1
#http://msdn.microsoft.com/en-us/library/cc240776.aspx
_TERMINAL_SERVICES_MODULUS_ = "\x3d\x3a\x5e\xbd\x72\x43\x3e\xc9\x4d\xbb\xc1\x1e\x4a\xba\x5f\xcb\x3e\x88\x20\x87\xef\xf5\xc1\xe2\xd7\xb7\x6b\x9a\xf2\x52\x45\x95\xce\x63\x65\x6b\x58\x3a\xfe\xef\x7c\xe7\xbf\xfe\x3d\xf6\x5c\x7d\x6c\x5e\x06\x09\x1a\xf5\x61\xbb\x20\x93\x09\x5f\x05\x6d\xea\x87"
_TERMINAL_SERVICES_PRIVATE_EXPONENT_ = "\x87\xa7\x19\x32\xda\x11\x87\x55\x58\x00\x16\x16\x25\x65\x68\xf8\x24\x3e\xe6\xfa\xe9\x67\x49\x94\xcf\x92\xcc\x33\x99\xe8\x08\x60\x17\x9a\x12\x9f\x24\xdd\xb1\x24\x99\xc7\x3a\xb8\x0a\x7b\x0d\xdd\x35\x07\x79\x17\x0b\x51\x9b\xb3\xc7\x10\x01\x13\xe7\x3f\xf3\x5f"
_TERMINAL_SERVICES_PUBLIC_EXPONENT_ = "\x5b\x7b\x88\xc0"
def __init__(self):
CompositeType.__init__(self)
self.dwSigAlgId = UInt32Le(0x00000001, constant = True)
self.dwKeyAlgId = UInt32Le(0x00000001, constant = True)
self.wPublicKeyBlobType = UInt16Le(0x0006, constant = True)
self.wPublicKeyBlobLen = UInt16Le(lambda:sizeof(self.PublicKeyBlob))
self.PublicKeyBlob = RSAPublicKey(readLen = self.wPublicKeyBlobLen)
self.wSignatureBlobType = UInt16Le(0x0008, constant = True)
self.wSignatureBlobLen = UInt16Le(lambda:(sizeof(self.SignatureBlob) - 8))
self.SignatureBlob = String(readLen = self.wSignatureBlobLen)
self.padding = String(b"\x00" * 8, readLen = UInt8(8))
def getPublicKey(self):
"""
@return: {Tuple} (modulus, publicExponent)
"""
log.debug("read RSA public key from proprietary certificate")
#reverse because bignum in little endian
return rsa.PublicKey(self.PublicKeyBlob.pubExp.value, self.PublicKeyBlob.modulus.value[::-1])
def computeSignatureHash(self):
"""
@summary: compute hash
"""
s = Stream()
s.writeType(UInt32Le(self.__class__._TYPE_))
s.writeType(self.dwSigAlgId)
s.writeType(self.dwKeyAlgId)
s.writeType(self.wPublicKeyBlobType)
s.writeType(self.wPublicKeyBlobLen)
s.writeType(self.PublicKeyBlob)
md5Digest = md5.new()
md5Digest.update(s.getvalue())
return md5Digest.digest() + "\x00" + "\xff" * 46 + "\x01"
def sign(self):
"""
@summary: sign proprietary certificate
@see: http://msdn.microsoft.com/en-us/library/cc240778.aspx
"""
self.SignatureBlob.value = rsa.sign(self.computeSignatureHash()[::-1], rsa.PrivateKey(d = ProprietaryServerCertificate._TERMINAL_SERVICES_PRIVATE_EXPONENT_[::-1], n = ProprietaryServerCertificate._TERMINAL_SERVICES_MODULUS_[::-1]))[::-1]
def verify(self):
"""
@summary: verify certificate signature
"""
return rsa.verify(self.SignatureBlob.value[::-1], rsa.PublicKey(e = ProprietaryServerCertificate._TERMINAL_SERVICES_PUBLIC_EXPONENT_[::-1], n = ProprietaryServerCertificate._TERMINAL_SERVICES_MODULUS_[::-1]))[::-1] == self.computeSignatureHash()
class CertBlob(CompositeType):
"""
@summary: certificate blob, contain x509 data
@see: http://msdn.microsoft.com/en-us/library/cc241911.aspx
"""
def __init__(self):
CompositeType.__init__(self)
self.cbCert = UInt32Le(lambda:sizeof(self.abCert))
self.abCert = String(readLen = self.cbCert)
class X509CertificateChain(CompositeType):
"""
@summary: X509 certificate chain
@see: http://msdn.microsoft.com/en-us/library/cc241910.aspx
"""
_TYPE_ = CertificateType.CERT_CHAIN_VERSION_2
def __init__(self):
CompositeType.__init__(self)
self.NumCertBlobs = UInt32Le()
self.CertBlobArray = ArrayType(CertBlob, readLen = self.NumCertBlobs)
self.padding = String(readLen = UInt8(lambda:(8 + 4 * self.NumCertBlobs.value)))
def getPublicKey(self):
"""
@return: {Tuple} (modulus, publicExponent)
"""
log.debug("read RSA public key from x509 certificate")
#last certifcate contain public key
n, e = x509.extractRSAKey(x509.load(self.CertBlobArray[-1].abCert.value))
return rsa.PublicKey(e, n)
def verify(self):
"""
@todo: verify x509 signature
"""
return True
class RSAPublicKey(CompositeType):
"""
@see: http://msdn.microsoft.com/en-us/library/cc240520.aspx
"""
def __init__(self, readLen):
CompositeType.__init__(self, readLen = readLen)
#magic is RSA1(0x31415352)
self.magic = UInt32Le(0x31415352, constant = True)
self.keylen = UInt32Le(lambda:(sizeof(self.modulus) + sizeof(self.padding)))
self.bitlen = UInt32Le(lambda:((self.keylen.value - 8) * 8))
self.datalen = UInt32Le(lambda:((self.bitlen.value / 8) - 1))
self.pubExp = UInt32Le()
self.modulus = String(readLen = UInt16Le(lambda:(self.keylen.value - 8)))
self.padding = String("\x00" * 8, readLen = UInt8(8))
class ChannelDef(CompositeType):
"""
Channels structure share between client and server
@see: http://msdn.microsoft.com/en-us/library/cc240513.aspx
"""
def __init__(self, name = "", options = 0):
CompositeType.__init__(self)
#name of channel
self.name = String(name[0:8] + "\x00" * (8 - len(name)), readLen = UInt8(8))
#unknown
self.options = UInt32Le()
class ClientNetworkData(CompositeType):
"""
GCC client network block
All channels asked by client are listed here
@see: http://msdn.microsoft.com/en-us/library/cc240512.aspx
"""
_TYPE_ = MessageType.CS_NET
def __init__(self, readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.channelCount = UInt32Le(lambda:len(self.channelDefArray._array))
self.channelDefArray = ArrayType(ChannelDef, readLen = self.channelCount)
class ServerNetworkData(CompositeType):
"""
GCC server network block
All channels asked by client are listed here
@see: All channels asked by client are listed here
"""
_TYPE_ = MessageType.SC_NET
def __init__(self, readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.MCSChannelId = UInt16Le(mcs.Channel.MCS_GLOBAL_CHANNEL)
self.channelCount = UInt16Le(lambda:len(self.channelIdArray._array))
self.channelIdArray = ArrayType(UInt16Le, readLen = self.channelCount)
self.pad = UInt16Le(conditional = lambda:((self.channelCount.value % 2) == 1))
class Settings(CompositeType):
"""
Class which group all clients settings supported by RDPY
"""
def __init__(self, init = [], readLen = None):
CompositeType.__init__(self, readLen = readLen)
self.settings = ArrayType(DataBlock, [DataBlock(i) for i in init])
def getBlock(self, messageType):
"""
@param messageType: type of block
@return: specific block of type messageType
"""
for i in self.settings._array:
if i.type.value == messageType:
return i.dataBlock
return None
def __getattr__(self, name):
"""
@summary: Magic function for better access
@return: _value parameter
"""
if not name in MessageType.__dict__:
return None
return self.getBlock(MessageType.__dict__[name])
def clientSettings():
"""
Build settings for client
@return: Settings
"""
return Settings([ClientCoreData(), ClientNetworkData(), ClientSecurityData()])
def serverSettings():
"""
Build settings for server
@return Settings
"""
return Settings([ServerCoreData(), ServerSecurityData(), ServerNetworkData()])
def readConferenceCreateRequest(s):
"""
Read a response from client
GCC create request
@param s: Stream
@param client settings (Settings)
"""
per.readChoice(s)
per.readObjectIdentifier(s, t124_02_98_oid)
per.readLength(s)
per.readChoice(s)
per.readSelection(s)
per.readNumericString(s, 1)
per.readPadding(s, 1)
if per.readNumberOfSet(s) != 1:
raise InvalidExpectedDataException("Invalid number of set in readConferenceCreateRequest")
if per.readChoice(s) != 0xc0:
raise InvalidExpectedDataException("Invalid choice in readConferenceCreateRequest")
per.readOctetStream(s, h221_cs_key, 4)
length = per.readLength(s)
clientSettings = Settings(readLen = UInt32Le(length))
s.readType(clientSettings)
return clientSettings
def readConferenceCreateResponse(s):
"""
Read response from server
and return server settings read from this response
@param s: Stream
@return: ServerSettings
"""
per.readChoice(s)
per.readObjectIdentifier(s, t124_02_98_oid)
per.readLength(s)
per.readChoice(s)
per.readInteger16(s, 1001)
per.readInteger(s)
per.readEnumerates(s)
per.readNumberOfSet(s)
per.readChoice(s)
if not per.readOctetStream(s, h221_sc_key, 4):
raise InvalidExpectedDataException("cannot read h221_sc_key")
length = per.readLength(s)
serverSettings = Settings(readLen = UInt32Le(length))
s.readType(serverSettings)
return serverSettings
def writeConferenceCreateRequest(userData):
"""
Write conference create request structure
@param userData: Settings for client
@return: GCC packet
"""
userDataStream = Stream()
userDataStream.writeType(userData)
return (per.writeChoice(0), per.writeObjectIdentifier(t124_02_98_oid),
per.writeLength(len(userDataStream.getvalue()) + 14), per.writeChoice(0),
per.writeSelection(0x08), per.writeNumericString("1", 1), per.writePadding(1),
per.writeNumberOfSet(1), per.writeChoice(0xc0),
per.writeOctetStream(h221_cs_key, 4), per.writeOctetStream(userDataStream.getvalue()))
def writeConferenceCreateResponse(serverData):
"""
Write a conference create response packet
@param serverData: Settings for server
@return: gcc packet
"""
serverDataStream = Stream()
serverDataStream.writeType(serverData)
return (per.writeChoice(0), per.writeObjectIdentifier(t124_02_98_oid),
per.writeLength(len(serverDataStream.getvalue()) + 14), per.writeChoice(0x14),
per.writeInteger16(0x79F3, 1001), per.writeInteger(1), per.writeEnumerates(16),
per.writeNumberOfSet(1), per.writeChoice(0xc0),
per.writeOctetStream(h221_sc_key, 4), per.writeOctetStream(serverDataStream.getvalue()))