About testssl.sh
testssl.sh is a free command line tool for checking how a server handles TLS and SSL encryption. It runs from a Unix-style shell and tests a server's service on any port.
What it does
The tool connects to a server and reports which TLS and SSL protocol versions and cipher suites it accepts. It also checks for known cryptographic flaws and weak settings, so administrators can see what needs fixing. Because it works on any port, it is not limited to websites.
Key features
- Checks which TLS and SSL protocols a server accepts
- Lists supported cipher suites
- Looks for known TLS and cryptographic flaws
- Tests services on any port, not only HTTPS
- Runs as a shell script from the command line
Who it's for
testssl.sh suits system administrators, security engineers and developers who need to audit how a server handles encryption. It is useful for checking websites and other TLS services.
Pricing and good to know
The tool is free and open source under the GPL-2.0 license, and its source is on GitHub. It needs a Unix-style shell and standard tools, so it runs best on Linux or macOS. Only test servers you have permission to test.
Highlights
- Checks which TLS and SSL protocols a server accepts
- Lists supported cipher suites
- Looks for known TLS and cryptographic flaws
- Tests services on any port, not only HTTPS
- Runs as a shell script from the command line
