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Dirk Wetter ae21ef7eab
Merge pull request #1987 from drwetter/fix_1982_kali.cnf
6 days ago
.github Typos found by codespell 7 days ago
bin Trim excess whitespace 2 weeks ago
doc Typos found by codespell 7 days ago
etc Fix #1982: Newer openssl.cnf break openssl detection 6 days ago
t Fix GHA (starttls nntp) 2 weeks ago
utils Typos found by codespell 7 days ago
.dockerignore Ignore FreeBSD & macOS OpenSSL binary in Dockerfile 3 months ago
.editorconfig Add a basic .editorconfig into project, close #1901 4 months ago
.gitignore .gitignore: ignore HTML scan results like example.com_p443-20201103-1037.html 11 months ago Typos found by codespell 7 days ago Trim excess whitespace 2 weeks ago Fix spelling 2 weeks ago Trim excess whitespace 2 weeks ago
Dockerfile Trim excess whitespace 2 weeks ago
Dockerfile.git Trim excess whitespace 2 weeks ago Update 10 months ago
LICENSE Use license file from 2 weeks ago Typos found by codespell 7 days ago
openssl-iana.mapping.html whitespace alignment 6 months ago Fix #1982: Newer openssl.cnf break openssl detection 6 days ago


Build Status Gitter License Docker is a free command line tool which checks a server's service on any port for the support of TLS/SSL ciphers, protocols as well as some cryptographic flaws.

Key features

  • Clear output: you can tell easily whether anything is good or bad.
  • Machine readable output (CSV, two JSON formats)
  • No need to install or to configure something. No gems, CPAN, pip or the like.
  • Works out of the box: Linux, OSX/Darwin, FreeBSD, NetBSD, MSYS2/Cygwin, WSL (bash on Windows). Only OpenBSD needs bash.
  • A Dockerfile is provided, there's also an official container build @ dockerhub.
  • Flexibility: You can test any SSL/TLS enabled and STARTTLS service, not only web servers at port 443.
  • Toolbox: Several command line options help you to run your test and configure your output.
  • Reliability: features are tested thoroughly.
  • Privacy: It's only you who sees the result, not a third party.
  • Freedom: It's 100% open source. You can look at the code, see what's going on.
  • The development is open (GitHub) and participation is welcome.


This software is free. You can use it under the terms of GPLv2, see LICENSE.

Attribution is important for the future of this project -- also in the internet. Thus if you're offering a scanner based on as a public and/or paid service in the internet you are strongly encouraged to mention to your audience that you're using this program and where to get this program from. That helps us to get bugfixes, other feedback and more contributions.

Compatibility is working on every Linux/BSD distribution out of the box. Latest by 2.9dev most of the limitations of disabled features from the openssl client are gone due to bash-socket-based checks. As a result you can also use e.g. LibreSSL or OpenSSL >= 1.1.1 . also works on other unixoid systems out of the box, supposed they have /bin/bash >= version 3.2 and standard tools like sed and awk installed. An implicit (silent) check for binaries is done when you start . System V needs probably to have GNU grep installed. MacOS X and Windows (using MSYS2, Cygwin or WSL) work too.

Update notification here or @ twitter.


You can download branch 3.1dev just by cloning this git repository:

git clone --depth 1

Think of 3.1dev like a rolling release, see below. For the stable version help yourself by downloading the ZIP or tar.gz archive. Just cd to the directory created (=INSTALLDIR) and run it off there.

Docker has minimal requirements. As stated you don't have to install or build anything. You can just run it from the pulled/cloned directory. Still if you don't want to pull the GitHub repo to your directory of choice you can pull a container from dockerhub and run it:

docker run --rm -ti  drwetter/ <your_cmd_line>

Or if you have cloned this repo you also can just cd to the INSTALLDIR and run

docker build . -t imagefoo && docker run --rm -t imagefoo

For more please consult


We're currently in the development phase, version 3.1dev. 3.1dev will eventually become 3.2. Bigger features are developed in a separate branch before merged into 3.1dev to avoid hiccups or inconsistencies. Albeit we try to keep 3.1dev as solid as possible things will certainly change in 3.1dev. Think of the 3.1dev branch like a rolling release. So if you need stability the 3.0 branch is better for you.

Version 3.0.X receives bugfixes, labeled as 3.0.1, 3.0.2 and so on. This will happen until 3.2 is released.

Support for 2.9.5 has been dropped. Supported is >= 3.0.x only.


  • .. it is there for reading. Please do so :-) -- at least before asking questions. See man page in groff, html and markdown format in ~/doc/.
  • will help to get you started.
  • For the (older) version 2.8 will Hunt provides a longer, good description, including useful background info.


Contributions are welcome! See for details. Please also have a look at the Coding Convention.

Bug reports

Bug reports are important. It makes this project more robust.

Please file bugs in the issue tracker @ GitHub. Do not forget to provide detailed information, see template for issue, and further details @ Nobody can read your thoughts -- yet. And only agencies your screen ;-)

You can also debug yourself, see here.

Please address questions not specifically to the code of to the respective projects below.

Web frontend

Free to use Web frontend + commercial API

Mass scanner w parallel scans and elastic searching the results

Another ready-to-go docker image is at:

Privacy checker using

Nagios / Icinga Plugins

Brew package

Daemon for batch execution of command files

Daemon for batch processing of JSON result files for sending Slack alerts, reactive copying etc

GitHub Actions