In some cases, the "TLS extensions" line output for the "--server-defaults" option will not show `"encrypt-then-mac/#22"` even if the server supports this extension. The reason is that a server will only include this extension in the ServerHello message if it supports the extension and the selected cipher is a CBC cipher. So, if `determine_tls_extensions()` connects to the server with a non-CBC cipher, then it will not detect if the server supports the encrypt-then-mac extension.
It is possible that support for the extension will be detected by `get_server_certificate()`, but only if one of the calls to that function results in a CBC cipher being selected and OpenSSL 1.1.0 is being used (as prior versions did not support the encrypt-then-mac extension).
In this PR, if `determine_tls_extensions()` is called and `$TLS_EXTENSIONS` does not already contain `"encrypt-then-mac/#22"`, then an attempt will be made to connect to the server with only CBC ciphers specified in the ClientHello. If the connection is not successful (presumably because the server does not support any CBC ciphers), then a second connection attempt will be made with the "default" ciphers being specified in the ClientHello.
en.wikipedia.org is an example of a server that supports the encrypt-then-mac extension, but for which the support is not currently detected (unless OpenSSL 1.1.0 is used) since in the call to `determine_tls_extension()` a non-CBC cipher is selected.
This PR changes `read_dhbits_from_file()` so that, when the "quiet" parameter is absent, the selected curve is shown in addition to the number of bits. This PR only affects the output of `run_client_simulation()` and the `Negotiated cipher` in `run_server_preference()`.
There are two places in `run_client_simulation()` in which `$OPENSSL s_client` is called, after which there is a `debugme echo` line to display the `$OPENSSL s_client` command line when testssl.sh is being run in debug mode, and then `sclient_connect_successful $? $TMPFILE` is called to determine whether `$OPENSSL s_client` successfully established a connection.
So, `sclient_connect_successful()` is being passed the result of the `debugme()` call, which always returns 0, rather than the result of the `$OPENSSL s_client` call.
This PR fixes the problem by moving the `debugme()` line to before the call to `$OPENSSL s_client`, so that `sclient_connect_successful()` is passed the results of the `$OPENSSL s_client` call.
This PR adds a new utility that generates the various static cipher lists that appear in testssl.sh.
This utility serves two purposes:
* It can be run whenever new ciphers are added to cipher-mapping.txt to see if any of the lists in testssl.sh need to be updated. (This includes if cipher-mapping.txt is modified to add OpenSSL-style names for ciphers that are currently listed, but that have not yet been assigned such names.)
* It can be used as a reference in order to understand how each of the lists is defined.
Starting with OpenSSL 1.1.0, s_client will not offer TLS compression methods, even if OpenSSL is compiled with zlib support, unless the `-comp` flag is included in the command line.
David Cooper
Dirk