Identifying weak implementations of SSL/TLS

As you learned in the previous section, TLS is a combination of various encryption algorithms packaged into one in order to provide confidentiality, integrity, and authentication. In the first step, when two endpoints negotiate for an SSL connection, they identify the common cipher suites supported by them. This allows SSL to support a wide variety of devices, which may not have the hardware and software to support the newer ciphers. Supporting older encryption algorithms has a major drawback. Most older cipher suites are easily breakable in a reasonable amount of time by cryptanalysts using the computing power available today.

The OpenSSL command-line tool

In order to identify the cipher suites negotiated by the remote web server, you can use the OpenSSL command-line tool that comes preinstalled on all major Linux distributions, and it is also included in Kali Linux. The tool can be used to test the various functions of the OpenSSL library directly...