CODEWITHSUNDEEP
javasslcryptographybouncycastletls1.2
KimHansen
KimHansen

Reputation: 377

Use Java Bouncy Castle to list cipher suites supported by server

Is it possible from Java Bouncy Castle to connect to a remote server using SSL/TLS and then get a list of supported cipher suites by the server? I need to receive the HEX value of it and if possible also the 'string-constant' of it (maybe just for the ones that the client knows of it self).

I need to connect to whatever port using whatever protocol (HTTPS, AMQPS, STOMPS, ...).

Upvotes: 2

Views: 1537

Answers (1)

Maarten Bodewes
Maarten Bodewes

Reputation: 94058

What you can do is to write a CipherSuiteFinder class that calls a rewritten TlsClientProtocol that simply offers up a single cipher suite to the server. To do this you create a new class derived from DefaultTlsClient that extends AbstractTlsClient.

After offering up the protocol and receiving the response you close the connection. If the server didn't error out it accepted the single offered cipher suite, which means this cipher suite is present. You then nicely close the connection by following the TLS standard to close the connection, only closing the socket after everything is done.

Now the CipherSuiteFinder just has to iterate through the cipher suites and collect the results.

The top level protocols such as HTTP and STOMP do not matter; they are only invoked after the TLS connection has been established.

Upvotes: 2

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