Fast Server Configuration¶

Server configuration is stored inside a YAML file named server.yaml. Fast looks for the configuration file within the current working directory. This allows having multiple separate configurations and environments for different competitions.

The server.yaml file is composed of multiple sections, each used for configuring different aspects of the tool. These sections are described in detail below.

Game Settings required¶

The game section includes game-related settings that should match the competition's requirements and your team's properties within the competition. This configuration is retrieved by the clients, allowing them to extract flags based on the flag format and synchronize the attacks with the server's tick timing. This way you have to configure only the server, while the clients will automatically configure themselves upon connecting.

Examples¶

a. Complete configuration

game:
  tick_duration: 80
  flag_format: ENO[A-Za-z0-9+\/=]{48}
  team_ip: 10.1.26.1

About the Example

Exploits will reload and rerun every 80 seconds, flags will be collected using the given regex, and alerts will appear on the dashboard each time an exploit retrieves a flag from your own service (target 10.1.26.1).

Options¶

The section starts with the keyword game: placed anywhere at the root level of the file.

tick_duration required

Tick duration in seconds. The duration is given by the competition organizers.

flag_format required

Regex pattern for flag matching. The pattern is given by the competition organizers. Knowing the pattern allows the clients to extract flags from exploit scripts' return values.

team_ip required

Your team's IP address. Fast will not submit flags originating from this IP. Instead, it will trigger an alert on the dashboard indicating that your exploit affects your own service and immediate patching is required.

To specify multiple IP addresses (e.g. for Ubuntu, Fedora and Windows machines), use a list like [10.1.26.1, 10.1.26.2, 10.1.26.3].

Submitter required¶

The submitter section is used for configuring the delay and optionally the module used for flag submission. The submitter module (default submitter.py) must be placed in the current working directory. For more details on writing this module, read the Submitter Guideline.

Examples¶

a. Minimal

submitter:
  delay: 20

About the Example

Flags will be submitted 20 seconds after the beginning of each tick using the submitter.py script placed in the same directory.

b. Setting a custom module name

submitter:
  delay: 20
  module: ecsc_submitter_v2

About the Example

Flags will be submitted 20 seconds after the beginning of each tick using the ecsc_submitter_v2.py script placed in the same directory.

Options¶

The section starts with the keyword submitter: placed anywhere at the root level of the file.

delay required: Number of seconds to wait before submitting the flags. The time is relative to the beginning of the tick.

Hint

Choose a value based on the estimated time it takes for all your exploits to complete. Try not to submit too early or too late.
module default = submitter: Custom name of your submitter module. Omit this field if your submitter module is named submitter.py; otherwise, name it to match its module name (without .py extension).

Server¶

The server section is used for configuring the gevent server Fast runs on. That includes configuring the host, port, and the password.

These settings must be shared with everyone on the team running Fast clients, allowing them to configure the necessary connection parameters.

Omitting this section results in using the default settings, making the server available on port 2023 with no password required.

Examples¶

a. Running on a custom port and setting the HTTP Basic Auth password

server:
  port: 80
  password: Noflags4you!

About the Example

Fast server will run on the port 80 and will require a password for connecting and accessing the web dashboard.

Options¶

The section starts with the keyword server: placed anywhere at the root level of the file.

host default = 0.0.0.0: Host address on which the server will run. By default, it will listen on all available network interfaces.
port default = 2023: Port number on which the server will accept connections. Default is 2023.
password default = None: Enables HTTP Basic Authentication and sets the password for Fast clients and web dashboard. Omit this field to disable password authentication. It's highly recommended to set a password to deter unauthorized access, especially if your server is publicly accessible (e.g. running on a VPS).

Database Connection¶

The database section is used for configuring the parameters for connecting to the Postgres database used for storing flags. This includes the database name, user, password, host, and port.

Omitting this section results in using the default values, making Fast connect to a database named fast on localhost:5432 with the credentials admin:admin.

You can execute the following command to spin up a "default" database locally using Docker:

docker pull postgres:alpine && docker run --name "fast_database_container" -e POSTGRES_DB="fast" -e POSTGRES_USER="admin" -e POSTGRES_PASSWORD="admin" -p 5432:5432 -d postgres

You can use the same command to run Postgres Docker image with different variables. The database may be hosted on the same machine or on a separate server, depending on your preference and setup requirements.

Examples¶

a. Setting database name and credentials

database:
  name: fast_db_2023
  user: cyberhero
  password: zU189&63!Ixq

About the Example

Fast server will connect to a database named fast_db_2023 running on localhost at port 5432, with the credentials cyberhero:zU189&63!Ixq.

Options¶

The section starts with the keyword database: placed anywhere at the root level of the file.

name default = fast: Name of the database.
user default = admin: Username for authenticating with the database.
password default = admin: Password for authenticating with the database.
host default = localhost: Host address of the database server. By default, Fast will connect to a database running on localhost.
port default = 5432: Port number on which the database server is listening. Default is 5432, same as the Postgres default.