public static IPEndPoint DecodeStunAddress(
this byte[] encoded, byte[] transactionId
)
{
uint cookie = StunMessage.MagicCookie.ToUInt();
bool inTransaction = transactionId != null;
using (var ms = new MemoryStream(encoded))
{
ms.ReadByte();
StunAf family = (StunAf)ms.ReadByte();
var portBytes = new byte[2];
ms.Read(portBytes, 0, 2);
int port = inTransaction
? (int)(portBytes.ToUShort() ^ (cookie >> 16))
: portBytes.ToUShort();
byte[] addrBytes = null;
switch (family)
{
case StunAf.IpV4:
addrBytes = new byte[4];
ms.Read(addrBytes, 0, 4);
uint addr = inTransaction
? addrBytes.ToUInt() ^ cookie
: addrBytes.ToUInt();
addrBytes = addr.ToBytes();
break;
case StunAf.IpV6:
addrBytes = new byte[16];
ms.Read(addrBytes, 0, 16);
foreach (var index in
Enumerable.Range(0, 16))
{
addrBytes[index] ^= index < 4
? StunMessage.MagicCookie[index]
: transactionId[index - 4];
}
break;
default:
throw new InvalidStunAddressException(
$"Unknown address familiy {family}.");
}
return(new IPEndPoint(
new IPAddress(addrBytes),
port));
}
}
public static IPEndPoint DecodeStunAddress(
this byte[] encoded, byte[] transactionId
)
{
uint cookie = StunMessage.MagicCookie.ToUInt();
bool inTransaction = transactionId != null;
using (var ms = new MemoryStream(encoded))
{
ms.ReadByte();
StunAf family = (StunAf)ms.ReadByte();
var portBytes = new byte[2];
ms.Read(portBytes, 0, 2);
int port = inTransaction
? (int)(portBytes.ToUShort() ^ (cookie >> 16))
: portBytes.ToUShort();
switch (family)
{
case StunAf.IpV4:
var addrBytes = new byte[4];
ms.Read(addrBytes, 0, 4);
uint addr = inTransaction
? addrBytes.ToUInt() ^ cookie
: addrBytes.ToUInt();
return(new IPEndPoint(
new IPAddress(addr.ToBytes()),
port));
default:
throw new InvalidStunAddressException(
$"Unknown address familiy {family}.");
}
}
}
