Firewall-Blocker

About

This program is meant to automate configuration of a SonicWall firewall via the SonicOS TI API. Currently this program is just meant to insert IP's from our Azure Sentinel TI pool. The program triggers by listening to a toppic on a message provider. (Currently only Azure Service Bus)

Instalation

Currently the app is bundled with the runtime environment and does not need any installation. However if you want to install it as a service/daemon follow the instructions in the next sections.

Usage

Windows

• Grab the latest windows release and place it in a folder together with the appsettings.json.
• Configure the appsettings to your liking.
• Run the FirewallBlocker.exe

Setup service

• Use the sc.exe (Windows Service Control Manager) to create a windows service: sc.exe create "Firewall Blocker" binpath="C:\Path\To\FirewallBlocker.exe --contentRoot C:\Path\To\appsettings.json"
• More info can be found here.

Linux

• Grab the latest windows release and place it in a folder together with the appsettings.json.
• Configure the appsettings to your liking.
• Make the FirewallBlocker file executable with chmod +x FirewallBlocker.
• Run the executable.

Setup daemon

• After downloading the file create a user to run the service
• Finaly create a the fw_blocker.service file inside /etc/systemd/system/
• Use the following template as input for your fw_blocker.service file.

[Unit]
Description=ingest_threat_intel
After=network.target

[Service]
User=USER_ID
Group=GROUP_ID
ExecStart=/Location/Of/Executable/FirewallBlocker
Type=notify
AmbientCapabilities=CAP_NET_BIND_SERVICE

[Install]
WantedBy=multi-user.target

Configuration

{
    "Logging": 
    {
        "LogLevel": 
        {
            "Default": "Information",
            "Microsoft": "Warning",
            "Microsoft.Hosting.Lifetime": "Information"
        },
        //Only needed if running on Windows
        "EventLog": {
            "SourceName": "Firewall Blocker",
            "LogName": "Application",
            "LogLevel": {
                "Default": "Information",
                "Microsoft": "Information",
                "Microsoft.Hosting.Lifetime": "Information"
            }
        }
    },
    "FirewallConfig":
    {
        "SonicWalls":
        [
            {
                "FireWallEndpoint": "https://firewall:8443",
                "Username": "USERNAME",
                "Password": "PASSWORD",
                "ValidateSSL": true
            }
        ]
    },
    //SourceConfig is used to specify where your TI comes from.
    "SourceConfig": {
        //CSVConfig is used to ingest a CSV file
        "CSVConfig": {
            "URI": "",
            "AuthValue": "",
            "AuthSchema": "Bearer",
            "ValidateSSL": true,
            "MaxCount": 100,
            "SortBy": [
                "SCORE",
                "TIME"
            ],
            //The Schema of the CSV.
            //WARNING: It is currently not supported to use a CSV file with no headers!
            "Schema": [
                {
                    "Name": "IP",
                    "CSVType": "IP"
                },
                {
                    "Name": "Score",
                    "CSVType": "SCORE"
                },
                {
                    "Name": "Time",
                    "CSVType": "TIME"
                }
            ]
        },
        "ThreatIntelApiConfig": {
            "ClientId": "",
            "TenantId": "",
            "ClientSecret": "",
            "WorkspaceId": "",
            "MinConfidence": 25,
            "ExclusionListAlias": "",
            "IPv4CollumName": ""
        }
    },
    "AppConfig": {
        "SiteName": "TestSite"
    },
    "ServiceBusConfig":
    {
        "ConnectionString": "CONNECTION_STRING"
    },
    "AllowedHosts": "*",
    "Kestrel": {
        "Endpoints": {
            "Http":{
                "Url": "http://0.0.0.0:80"
            },
            "HttpsDefaultCert":{
                "Url": "https://0.0.0.0:443"
            }
        },
        "Certificates": {
            "Default": {
                "Path": "cert.pem",
                "KeyPath": "key.pem"
            }
        }
    }
}

Sonicwall configuration

To see the confiugration for the sonicwall you can look at this link: SonicOS TI API

Kestrel

Kestrel is a basic HTTP server used in ASP.NET. You can change the given configuration to limit it to a specific interface or add custom Certificates. Full configuration documentation can be found here. To access the list of IP addresses you can go to the interface & Port specified in the URL configuration.

Notes

A few things you should know.

• At the moment collecting the TI from the Graph API does not work.
• It is not reccomended to set the MinConfidence at 0. (A lot of IPs will be given.)
• The CSV Source must have headers and need to be defined in the Schema section.

Future

• RabbitMQ
• Other TI Sources
• Docker image
• Install script
• Fix Graph API
• Support other Firewalls