| public ToByteBuffer ( byte buffer, int startIndex ) : int | ||
| buffer | byte | |
| startIndex | int | |
| return | int | |
public byte[] ToByteBuffer(byte[] messageIntegrityKey, bool addFingerprint)
{
UInt16 attributesLength = 0;
foreach (STUNv2Attribute attribute in Attributes)
{
attributesLength += Convert.ToUInt16(STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + attribute.PaddedLength);
}
if (messageIntegrityKey != null)
{
attributesLength += STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + MESSAGE_INTEGRITY_ATTRIBUTE_HMAC_LENGTH;
}
int messageLength = STUNv2Header.STUN_HEADER_LENGTH + attributesLength;
byte[] buffer = new byte[messageLength];
if (BitConverter.IsLittleEndian)
{
Buffer.BlockCopy(BitConverter.GetBytes(Utility.ReverseEndian((UInt16)Header.MessageType)), 0, buffer, 0, 2);
Buffer.BlockCopy(BitConverter.GetBytes(Utility.ReverseEndian(attributesLength)), 0, buffer, 2, 2);
Buffer.BlockCopy(BitConverter.GetBytes(NetConvert.DoReverseEndian(STUNv2Header.MAGIC_COOKIE)), 0, buffer, 4, 4);
}
else
{
Buffer.BlockCopy(BitConverter.GetBytes((UInt16)Header.MessageType), 0, buffer, 0, 2);
Buffer.BlockCopy(BitConverter.GetBytes(attributesLength), 0, buffer, 2, 2);
Buffer.BlockCopy(BitConverter.GetBytes(STUNv2Header.MAGIC_COOKIE), 0, buffer, 4, 4);
}
Buffer.BlockCopy(Header.TransactionId, 0, buffer, 8, STUNv2Header.TRANSACTION_ID_LENGTH);
int attributeIndex = 20;
foreach (STUNv2Attribute attr in Attributes)
{
attributeIndex += attr.ToByteBuffer(buffer, attributeIndex);
}
//logger.LogDebug($"Pre HMAC STUN message: {ByteBufferInfo.HexStr(buffer, attributeIndex)}");
if (messageIntegrityKey != null)
{
var integrityAttibtue = new STUNv2Attribute(STUNv2AttributeTypesEnum.MessageIntegrity, new byte[MESSAGE_INTEGRITY_ATTRIBUTE_HMAC_LENGTH]);
HMACSHA1 hmacSHA = new HMACSHA1(messageIntegrityKey, true);
byte[] hmac = hmacSHA.ComputeHash(buffer, 0, attributeIndex);
integrityAttibtue.Value = hmac;
attributeIndex += integrityAttibtue.ToByteBuffer(buffer, attributeIndex);
}
if (addFingerprint)
{
// The fingerprint attribute length has not been included in the length in the STUN header so adjust it now.
attributesLength += STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + FINGERPRINT_ATTRIBUTE_CRC32_LENGTH;
messageLength += STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + FINGERPRINT_ATTRIBUTE_CRC32_LENGTH;
if (BitConverter.IsLittleEndian)
{
Buffer.BlockCopy(BitConverter.GetBytes(Utility.ReverseEndian(attributesLength)), 0, buffer, 2, 2);
}
else
{
Buffer.BlockCopy(BitConverter.GetBytes(attributesLength), 0, buffer, 2, 2);
}
var fingerprintAttribute = new STUNv2Attribute(STUNv2AttributeTypesEnum.FingerPrint, new byte[FINGERPRINT_ATTRIBUTE_CRC32_LENGTH]);
uint crc = Crc32.Compute(buffer) ^ FINGERPRINT_XOR;
byte[] fingerPrint = (BitConverter.IsLittleEndian) ? BitConverter.GetBytes(NetConvert.DoReverseEndian(crc)) : BitConverter.GetBytes(crc);
fingerprintAttribute.Value = fingerPrint;
Array.Resize(ref buffer, messageLength);
fingerprintAttribute.ToByteBuffer(buffer, attributeIndex);
}
return(buffer);
}
public byte[] ToByteBuffer(string messageIntegrityKey, bool addFingerprint)
{
UInt16 attributesLength = 0;
foreach (STUNv2Attribute attribute in Attributes)
{
attributesLength += Convert.ToUInt16(STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + attribute.PaddedLength);
}
if(messageIntegrityKey.NotNullOrBlank())
{
attributesLength += STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + MESSAGE_INTEGRITY_ATTRIBUTE_HMAC_LENGTH;
}
int messageLength = STUNv2Header.STUN_HEADER_LENGTH + attributesLength;
byte[] buffer = new byte[messageLength];
if (BitConverter.IsLittleEndian)
{
Buffer.BlockCopy(BitConverter.GetBytes(Utility.ReverseEndian((UInt16)Header.MessageType)), 0, buffer, 0, 2);
Buffer.BlockCopy(BitConverter.GetBytes(Utility.ReverseEndian(attributesLength)), 0, buffer, 2, 2);
Buffer.BlockCopy(BitConverter.GetBytes(NetConvert.DoReverseEndian(STUNv2Header.MAGIC_COOKIE)), 0, buffer, 4, 4);
}
else
{
Buffer.BlockCopy(BitConverter.GetBytes((UInt16)Header.MessageType), 0, buffer, 0, 2);
Buffer.BlockCopy(BitConverter.GetBytes(attributesLength), 0, buffer, 2, 2);
Buffer.BlockCopy(BitConverter.GetBytes(STUNv2Header.MAGIC_COOKIE), 0, buffer, 4, 4);
}
Buffer.BlockCopy(Header.TransactionId, 0, buffer, 8, STUNv2Header.TRANSACTION_ID_LENGTH);
int attributeIndex = 20;
foreach (STUNv2Attribute attr in Attributes)
{
attributeIndex += attr.ToByteBuffer(buffer, attributeIndex);
}
if (messageIntegrityKey.NotNullOrBlank())
{
var integrityAttibtue = new STUNv2Attribute(STUNv2AttributeTypesEnum.MessageIntegrity, new byte[MESSAGE_INTEGRITY_ATTRIBUTE_HMAC_LENGTH]);
HMACSHA1 hmacSHA = new HMACSHA1(System.Text.Encoding.UTF8.GetBytes(messageIntegrityKey), true);
byte[] hmac = hmacSHA.ComputeHash(buffer, 0, attributeIndex);
integrityAttibtue.Value = hmac;
attributeIndex += integrityAttibtue.ToByteBuffer(buffer, attributeIndex);
}
if (addFingerprint)
{
// The fingerprint attribute length has not been included in the length in the STUN header so adjust it now.
attributesLength += STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + FINGERPRINT_ATTRIBUTE_CRC32_LENGTH;
messageLength += STUNv2Attribute.STUNATTRIBUTE_HEADER_LENGTH + FINGERPRINT_ATTRIBUTE_CRC32_LENGTH;
if (BitConverter.IsLittleEndian)
{
Buffer.BlockCopy(BitConverter.GetBytes(Utility.ReverseEndian(attributesLength)), 0, buffer, 2, 2);
}
else
{
Buffer.BlockCopy(BitConverter.GetBytes(attributesLength), 0, buffer, 2, 2);
}
var fingerprintAttribute = new STUNv2Attribute(STUNv2AttributeTypesEnum.FingerPrint, new byte[FINGERPRINT_ATTRIBUTE_CRC32_LENGTH]);
uint crc = Crc32.Compute(buffer) ^ FINGERPRINT_XOR;
byte[] fingerPrint = (BitConverter.IsLittleEndian) ? BitConverter.GetBytes(NetConvert.DoReverseEndian(crc)) : BitConverter.GetBytes(crc);
fingerprintAttribute.Value = fingerPrint;
Array.Resize(ref buffer, messageLength);
fingerprintAttribute.ToByteBuffer(buffer, attributeIndex);
}
return buffer;
}
