TLS-Scanner

TLS-Scanner is a tool to assist pentesters and security researchers in the evaluation of TLS server and client configurations.

Please note: TLS-Scanner is a research tool intended for TLS developers, pentesters, administrators and researchers. There is no GUI. It is in the first version and may contain some bugs.

Compiling

In order to compile and use TLS-Scanner, you need to run:

$ cd TLS-Scanner
$ git submodule update --init --recursive
$ mvn clean package

Alternatively, if you are in a hurry, you can skip the tests by using:

$ mvn clean package -DskipTests=true

If you want to use TLS-Scanner as a library you need to install it with the following command:

$ mvn clean install

Running

In order to run TLS-Scanner you need to run the jar file in the apps/ folder.

$ java -jar apps/TLS-Server-Scanner.jar -connect localhost:4433

You can specify a host you want to scan with the -connect parameter. If you want to improve the performance of the scan you can use the -threads parameter (default=1).

In order to see more details about the Guidelines, use "-reportDetail ALL".

Docker

We provide you with a Dockerfile, which lets you run the scanner directly:

$ docker build . -t tlsscanner
$ docker run -t tlsscanner

Please note: I am by no means familiar with Docker best practices. If you know how to improve the Dockerfile feel free to issue a pull request

Requirement System

(TLS) probes sometimes have prerequisites that are required to execute this specific probe. The requirement system allows you to define sets of such requirements that must be met in order for the probe to be executed.

Each requirement offers an evaluate function which returns a boolean value indicating whether the requirement has been fulfilled. Requirements can be concatenated in several ways using well-known logical operations. Each requirement offers and, or, not, and xor instance methods to chain multiple requirements. The following probes are currently implemented and can be used off the shelf:

• FulfilledRequirement - Always evalutes to true, useful to indicate no requirement.
• UnfulfillableRequirement - Always evalutes to false, prevents execution of probes.
• ProbeRequirement - Evaluates to true if the specified probe(s) has been executed.
• PropertyRequirement - Evaluates to true if the specified analyzed properties have a predefined value. The value may either be provided as a constructor parameter or one may use PropertyTrueRequirement and PropertyFalseRequirement as a shorthand for TestResults.TRUE and TestResults.FALSE.
• PropertyComparatorRequirement - Evaluates to true if the collection result of an analyzed property is smaller, equal, or greater than a constant value.
• ProtocolRequirement - Evaluates to true if certain protocol versions are supported.
• ExtensionRequirement - Evaluates to true if certain extensions are supported by the remote peer.
• OptionsRequirement - Evaluates to true if additional cli flags are set. Currently used in some client probes (ALPN, SNI, session resumption).
• WorkingConfigRequirement - Evaluates to true if a working configuration has been found.

Aside from these predefined requirements one may also extend the Requirement class anonymously within the getRequirements method. If nothing is required, you can use may return a FulfilledRequirement which always evaluates to true.

Examples on how to use requirements can be found in the probe packages of the tls-client-scanner and tls-server-scanner.

@Override
public Requirement<ClientReport> getRequirements() {
    return new ProbeRequirement<ClientReport>(TlsProbeType.CIPHER_SUITE)
            .and(new PropertyTrueRequirement<>(TlsAnalyzedProperty.SUPPORTS_DHE));
}