sebel

sebel is a Go package that provides functionality for checking SSL/TLS certificates against malicious connections, by identifying and blacklisting certificates used by botnet command and control (C&C) servers.

Usage

Setting up Sebel instance:

import "github.com/teler-sh/sebel"

// ...

s := sebel.New(Options{/* ... */})
defer s.Close() // Stop background refresh if enabled

[!NOTE] The Options parameter is optional. See Options for available configuration.

Examples

Next, set the transport for the HTTP client you are using:

// initialize Sebel (fetch SSLBL data)
s := sebel.New()
defer s.Close()

client := &http.Client{
    Transport: s.RoundTripper(http.DefaultTransport),
}

// now, you can use [client.Do], [client.Get], etc. to create requests.

resp, err := client.Get("https://c2.host")
if err != nil && sebel.IsBlacklist(err) {
    // certificate blacklisted
    panic(err)
}
defer resp.Body.Close()

Alternatively, for seamless integration without configuring a new client, replace your current default HTTP client with Sebel's RoundTripper:

http.DefaultClient.Transport = sebel.New().RoundTripper(http.DefaultTransport)

You can also check the certificate later using Sebel's CheckTLS.

r, err := http.Get("https://c2.host")
if err != nil {
	panic(err)
}
defer r.Body.Close()

s := sebel.New()

_, err = s.CheckTLS(r.TLS)
if err != nil && sebel.IsBlacklist(err) {
	// certificate blacklisted
	panic(err)
}

Or check a host directly using CheckHost:

s := sebel.New()

_, err := s.CheckHost("c2.host", "443", nil)
if err != nil && sebel.IsBlacklist(err) {
	// certificate blacklisted
	panic(err)
}

Background Refresh

To keep the SSLBL data up-to-date automatically:

s := sebel.New(sebel.Options{
    DataRefreshInterval: 5 * time.Minute,
})
defer s.Close() // Important: stop the background goroutine

client := &http.Client{
    Transport: s.RoundTripper(http.DefaultTransport),
}

These examples demonstrate various ways to set up Sebel and integrate it with HTTP clients for SSL/TLS certificate checks.

Status

[!CAUTION] Sebel has NOT reached 1.0 yet. Therefore, this library is currently not supported and does not offer a stable API; use at your own risk.

There are no guarantees of stability for the APIs in this library, and while they are not expected to change dramatically. API tweaks and bug fixes may occur.

License

sebel is released by @dwisiswant0 under the Apache 2.0 license. See LICENSE.

The data used in this project are © by abuse.ch under CC0.