Please note that the implementation is not 100% conformant to the protocol whitepaper (https://www.wireguard.com/papers/wireguard.pdf).
More specifically: all peers are expected to send a handshake initiation once the current keypair is about to expire or is expired.
I decided not to do that because our implementation is meant to act as a server only. A true WireGuard peer acts, instead, as both a client and a server.
Once the keypair is expired, we immediately delete the session.
The cookie mechanism can be implemented in future.
As for authentication: unfortunately using the already existing methods is not possible due to the protocol not providing a way to send strings to a peer.
That's because WireGuard doesn't have a concept of "users": it identifies a peer through the public key, which is determined using the source address.
As a solution, this commit adds a special authentication method: once we receive the handshake initiation message and decrypt the peer's public key, we check whether it's in the allowed key list.
If it is, we retrieve the associated Virtual Hub and user; if the hub exists and the user is in it, the authentication is successful.
The allowed key list is stored in the configuration file like this:
declare WireGuardKeyList
{
declare 96oA7iMvjn7oXiG3ghBDPaSUytT75uXceLV+Fx3XMlM=
{
string Hub DEFAULT
string User user
}
}
WireGuard does not provide any configuration messages, meaning that we cannot push the IP address we receive from the DHCP server to the client.
In order to overcome the limitation we don't perform any DHCP operations and instead just extract the source IP address from the first IPv4 packet we receive in the tunnel.
The gateway address and the subnet mask can be set using the new "SetStaticNetwork" command. The values can be retrieved using "OptionsGet".
In future we will add a "allowed source IP addresses" function, similar to what the original WireGuard implementation provides.
================================================================================
SetStaticNetwork command - Set Virtual Hub static IPv4 network parameters
Help for command "SetStaticNetwork"
Purpose:
Set Virtual Hub static IPv4 network parameters
Description:
Set the static IPv4 network parameters for the Virtual Hub. They are used when DHCP is not available (e.g. WireGuard sessions).
You can get the current settings by using the OptionsGet command.
Usage:
SetStaticNetwork [/GATEWAY:gateway] [/SUBNET:subnet]
Parameters:
/GATEWAY - Specify the IP address of the gateway that will be used for internet communication.
/SUBNET - Specify the subnet mask, required to determine the size of the local VPN network.
- Fixed the RADIUS PEAP client to use the standard TLS versioning.
- Implementation of a function to fix the MAC address of L3 VPN protocol by entering e.g. "MAC: 112233445566" in the "Notes" field of the user information.
- Implementation of a function to fix the virtual MAC address to be assigned to the L3 VPN client as a string attribute from RADIUS server when authentication.
- Hash() has been removed because it was ambiguous, Md5() and Sha0() are proper replacements.
- HMacMd5() and HMacSha1() now share a common implementation handled by the new Internal_HMac() function.
- NewMd() and MdProcess() now support plain hashing (without the key).
- NewMd(), SetMdKey() and MdProcess() now check the OpenSSL functions' return value and in case of failure a debug message is printed along with the error string, if available.
- SetMdKey()'s return value has been changed from void to bool, so that it's possible to know whether the function succeeded or not.
- MdProcess()' return value has been changed from void to UINT (unsigned int) and the function now returns the number of bytes written by HMAC_Final() or EVP_DigestFinal_ex().
