Docker image with PPTP server including routing and port forwarding

Description

Access private network from the internet, support port forwarding from private network to outside via cloud.

GitHub Project

Features

• Docker image
• Keycloak authentication and authorization
• Radius client
• support RadSec protocol (Radius over TLS)
• Management routing and portforwarding using json file
• Connect to LAN from the internet
• Port forwarding
• Connect multiple networks
• Automatic installation(Ubuntu)
• Manual Installation steps (Ubuntu)
• Deny user access to VPN

Example

Download

Get the trusted build from the Docker Hub registry:

docker pull vassio/pptp-radius-docker

Installation

create /opt/config.json

sudo apt-get update && sudo apt-get install -y curl
curl -sSL https://raw.githubusercontent.com/vzakharchenko/pptp-radius-docker/main/ubuntu.install -o ubuntu.install
chmod +x ubuntu.install
./ubuntu.install

Installation

• Release Setup
• Docker Setup
• Manual Setup

Configure Keycloak

1. Create Realm with Radius client
2. Create OIDC client to Radius Realm
3. Enable Service Accounts for OIDC client
4. Add role "Radius Session Role" to Service Accounts
5. Download Keycloak.json
6. add keycloak.json to config.json

{
  "radsec": {
    "privateKey": RADSEC_PRIVATE_KEY,
    "certificateFile": RADSEC_CERTIFICATE_FILE,
    "CACertificateFile": RADSEC_CA_CERTIFICATE_FILE,
    "certificateKeyPassword": RADSEC_PRIVATE_KEY_PASSWORD
  },
  "keycloak": {
    "json": {
        "realm": "VPN",
        "auth-server-url": "http://192.168.1.234:8090/auth/",
        "ssl-required": "external",
        "resource": "vpn-client",
        "credentials": {
            "secret": "12747feb-794b-4561-a54f-1f49e9366b21"
         },
        "confidential-port": 0
    }
  },
  "radius": {
    "protocol":"pap"
  }
}

config.json structure

{
  "radsec": {
    "privateKey": RADSEC_PRIVATE_KEY,
    "certificateFile": RADSEC_CERTIFICATE_FILE,
    "CACertificateFile": RADSEC_CA_CERTIFICATE_FILE,
    "certificateKeyPassword": RADSEC_PRIVATE_KEY_PASSWORD
  },
  "keycloak": {
    "json": KEYCLOAK_JSON
  },
  "radius": {
    "protocol":"RADIUS_PROTOCOL"
  },
  "authorizationMap": {
    "roles": {
      "KEYCLOAK_ROLE": {
        "routes": ROUTING_TABLE,
        "forwarding":{
            "sourceIp": APPLICATION_IP,
            "sourcePort": APPLICATION_PORT,
            "externalPort": REMOTE_PORT
        }
      }
    }
  }
}

Where

• RADSEC_PRIVATE_KEY ssl privateKey
• RADSEC_CERTIFICATE_FILE ssl private certificate
• CACertificateFile ssl CA certificate
• certificateKeyPassword privateKey password
• KEYCLOAK_JSON Keycloak.json
• RADIUS_PROTOCOL Radius protocol. Supported pap,chap and mschap-v2. If used RadSec(Radius over TLS) then better to use PAP, otherwise mschap-v2
• APPLICATION_IP service IP behind NAT (port forwarding)
• APPLICATION_PORT service PORT behind NAT (port forwarding)
• REMOTE_PORT port accessible from the internet (port forwarding)
• ROUTING_TABLE ip with subnet for example 192.168.8.0/24
• KEYCLOAK_ROLE Role assigned to user

Examples

Connect to LAN from the internet

user1 - router with subnet 192.168.88.0/24 behind NAT

user2 - user who has access to subnet 192.168.88.0/24 from the Internet

{
   "radsec":{
      "privateKey":"RADSEC_PRIVATE_KEY",
      "certificateFile":"RADSEC_CERTIFICATE_FILE",
      "CACertificateFile":"RADSEC_CA_CERTIFICATE_FILE",
      "certificateKeyPassword":"RADSEC_PRIVATE_KEY_PASSWORD"
   },
   "keycloak":{
      "json":{
         "realm":"VPN",
         "auth-server-url":"http://192.168.1.234:8090/auth/",
         "ssl-required":"external",
         "resource":"vpn-client",
         "credentials":{
            "secret":"12747feb-794b-4561-a54f-1f49e9366b21"
         },
         "confidential-port":0
      }
   },
   "radius":{
      "protocol":"pap"
   },
   "authorizationMap":{
      "roles":{
         "Role1":{
            "routing":[
               {
                  "route":"192.168.88.0/24"
               }
            ]
         }
      }
   }
}

Port forwarding

user - router with subnet 192.168.88.0/24 behind NAT.

Subnet contains service http://192.168.8.254:80 which is available at from http://195.138.164.211:9000

{
   "radsec":{
      "privateKey":"RADSEC_PRIVATE_KEY",
      "certificateFile":"RADSEC_CERTIFICATE_FILE",
      "CACertificateFile":"RADSEC_CA_CERTIFICATE_FILE",
      "certificateKeyPassword":"RADSEC_PRIVATE_KEY_PASSWORD"
   },
   "keycloak":{
      "json":{
         "realm":"VPN",
         "auth-server-url":"http://192.168.1.234:8090/auth/",
         "ssl-required":"external",
         "resource":"vpn-client",
         "credentials":{
            "secret":"12747feb-794b-4561-a54f-1f49e9366b21"
         },
         "confidential-port":0
      }
   },
   "radius":{
      "protocol":"pap"
   },
   "authorizationMap":{
      "roles":{
         "Role1":{
            "forwarding":[
               {
                  "sourceIp":"192.168.88.1",
                  "sourcePort":"80",
                  "destinationPort":9000
               }
            ]
         }
      }
   }
}

connect multiple networks

user1 - router with subnet 192.168.88.0/24 behind NAT. Subnet contains service http://192.168.88.254:80 which is available at from http://195.138.164.211:9000

user2 - router with subnet 192.168.89.0/24 behind NAT.

user3 - user who has access to subnets 192.168.88.0/24 and 192.168.89.0/24 from the Internet

{
   "radsec":{
      "privateKey":"RADSEC_PRIVATE_KEY",
      "certificateFile":"RADSEC_CERTIFICATE_FILE",
      "CACertificateFile":"RADSEC_CA_CERTIFICATE_FILE",
      "certificateKeyPassword":"RADSEC_PRIVATE_KEY_PASSWORD"
   },
   "keycloak":{
      "json":{
         "realm":"VPN",
         "auth-server-url":"http://192.168.1.234:8090/auth/",
         "ssl-required":"external",
         "resource":"vpn-client",
         "credentials":{
            "secret":"12747feb-794b-4561-a54f-1f49e9366b21"
         },
         "confidential-port":0
      }
   },
   "radius":{
      "protocol":"pap"
   },
   "authorizationMap":{
      "roles":{
         "Role1":{
            "forwarding":[
               {
                  "sourceIp":"192.168.88.254",
                  "sourcePort":"80",
                  "destinationPort":9000
               }
            ],
            "routing":[
               {
                  "route":"192.168.88.0/24"
               }
            ]
         },
         "Role2":{
            "routing":[
               {
                  "route":"192.168.89.0/24"
               }
            ]
         }
      }
   }
}

Troubleshooting

1. Viewing logs in docker container:

docker logs pptp-radius-docker -f

2. print routing tables

docker exec pptp-radius-docker bash -c "ip route"

3. print iptable rules

docker exec pptp-radius-docker bash -c "iptables -S"

Cloud Installation

Automatic cloud installation

create /opt/config.json

sudo apt-get update && sudo apt-get install -y curl
curl -sSL https://raw.githubusercontent.com/vzakharchenko/pptp-radius-docker/main/ubuntu.install -o ubuntu.install
chmod +x ubuntu.install
./ubuntu.install

Deny user access to VPN

• create client/realm role and add attribute:

REJECT_Connect-Info=L2TP

• assign a role to a user and after that the user will always be rejected

Manual Cloud Installation(Ubuntu)

1. install all dependencies

sudo apt-get update && sudo apt-get install -y iptables git iptables-persistent node

2. install docker

sudo apt-get remove docker docker.io containerd runc
sudo curl -sSL https://get.docker.com | bash
sudo groupadd docker
sudo usermod -aG docker $USER
newgrp docker

3. Configure host machine

echo "nf_nat_pptp" >> /etc/modules
echo "ip_gre" >> /etc/modules
iptables -I FORWARD -p gre -j ACCEPT
sudo iptables-save > /etc/iptables/rules.v4
sysctl -w net.ipv4.ip_forward=1
sysctl -w net.netfilter.nf_conntrack_helper=1
sudo echo "net.ipv4.ip_forward=1">/etc/sysctl.conf
sudo echo "net.netfilter.nf_conntrack_helper=1">/etc/sysctl.conf

4. create /opt/config.json

5. start docker image

export CONFIG_PATH=/opt/config.json
curl -sSL https://raw.githubusercontent.com/vzakharchenko/pptp-radius-docker/main/pptp-js/generateDockerCommands.js -o generateDockerCommands.js
`node generateDockerCommands.js`

6. reboot machine