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 `$OPENSSL s_client` call.
This PR adds a new utility that generates the various static cipher lists that appear in testssl.sh.
This utility serves two purposes:
* It can be run whenever new ciphers are added to cipher-mapping.txt to see if any of the lists in testssl.sh need to be updated. (This includes if cipher-mapping.txt is modified to add OpenSSL-style names for ciphers that are currently listed, but that have not yet been assigned such names.)
* It can be used as a reference in order to understand how each of the lists is defined.
Starting with OpenSSL 1.1.0, s_client will not offer TLS compression methods, even if OpenSSL is compiled with zlib support, unless the `-comp` flag is included in the command line.
This PR changes `run_crime()` to use `tls_sockets()` rather than failing if `$OPENSSL` lacks zlib support, unless `$SSL_NATIVE` is `true`.
At the moment, the ClientHello created by `socksend_tls_clienthello()` only specifies the NULL compression method. So, this PR adds a new parameter to `socksend_tls_clienthello()` and `tls_sockets()` to allow to caller to request that additional compression methods (DEFLATE and LZS) be specified in the ClientHello.
This PR makes another change to `run_crime()`. At the moment, if `$OPENSSL s_client` fails to connect to the server, `run_crime()` will report that the server is not vulnerable, since the output from `$OPENSSL s_client` includes the line "Compression: NONE" (see below). This PR changes that by checking whether the connection was successful, and reporting a "test failed (couldn't connect)" warning if it wasn't successful, rather than reporting "not vulnerable (OK)".
```
CONNECTED(00000003)
140338777061024:error:1407742E:SSL routines:SSL23_GET_SERVER_HELLO:tlsv1 alert protocol version:s23_clnt.c:769:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 7 bytes and written 389 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1
Cipher : 0000
Session-ID:
Session-ID-ctx:
Master-Key:
Key-Arg : None
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1483645971
Timeout : 300 (sec)
Verify return code: 0 (ok)
---
```
This PR fixes a few bugs in `sslv2_sockets()`. The main issue is that a server may not send the entire ServerHello in a single packet. If it doesn't and the full response is being parsed (i.e., certificate and list of ciphers), then `parse_sslv2_serverhello()` will encounter errors, since it assumes that it has the entire ServerHello. This PR compares the length of the response to the length of the ServerHello as specified in the first two bytes of the response and requests more data from the server if the response appears incomplete.
This PR also modifies `parse_sslv2_serverhello()` to check for more errors. It compares the length of the response it has been provided to the specified length (`$v2_hello_length`) and returns an error if the response is shorter than `$v2_hello_length` and the full response is supposed to be parsed. It will also check whether there was an error in converting the certificate from DER to PEM format and will return an error if there was (and it will suppress the error message).
Some servers respond to an SSLv2 ClientHello with a list of all SSLv2 ciphers that the server supports rather than just a list of ciphers that it supports in common with the client (i.e., that appear in the ClientHello). This PR changes the sockets version of `std_cipherlists()` so that, if `sslv2_sockets()` is successful, it checks whether there are any ciphers in common between the ClientHello and the ServerHello before declaring that the server supports the specified cipher list.
Some servers respond to an SSLv2 ClientHello with a list of all SSLv2 ciphers that the server supports rather than just a list of ciphers that it supports in common with the client (i.e., that appear in the ClientHello). This PR changes the sockets version of `run_freak()` so that, if `sslv2_sockets()` is successful, it checks whether there are any ciphers in common between the ClientHello and the ServerHello before declaring that the server supports an export RSA cipher.
If `determine_tls_extensions()` does not create a temporary file (`$TEMPDIR/$NODEIP.determine_tls_extensions.txt`) then `run_server_defaults()` will display error messages when an attempt is made to copy this file or to search (grep) it. This may happen if `$OPTIMAL_PROTO` is `-ssl2` or if `determine_tls_extensions()` uses sockets and `parse_tls_serverhello()` encountered an error and did not create a temporary file (`$TEMPDIR/$NODEIP.parse_tls_serverhello.txt`). This PR fixes this by only trying to copy and search `$TEMPDIR/$NODEIP.determine_tls_extensions.txt` is `$OPTIMAL_PROTO` is not `-ssl2` and `determine_tls_extensions()` was successful (return value 0).
In response to your request in #572, this PR provides a starting point for addressing #120. It adds code to `run_logjam()` to try connecting to the server using any cipher that uses an ephemeral DH key. If successful, it gets the server's ephemeral key (in OpenSSL's PEM format) and then extracts the prime from the key and places it in `$dh_p`. So, all that needs to be done at this point is to compare `$dh_p` against a set of "bad" primes. I'm not sure if I'll be able to work on that part soon, so if someone else has the time, that would be great.
I actually found the `-msg` option easy to use. I moved the code in `parse_tls_serverhello()` that extracts the DH ephemeral public key from the ServerKeyExchange message into a separate function. Then, if using OpenSSL with the `-msg` option, I extract the ServerKeyExchange message from `$TMPFILE` and call this new function to extract the key and convert it to PEM format. That way the new code in `run_logjam()` can use either `$OPENSSL` or `tls_sockets()`.
David Cooper
Dirk Wetter
Todd Swatling