This commit fixes#1433 by adding "@SECLEVEL=0" to the "$OPENSSL s_client" and "$OPENSSL ciphers" command lines if that option is supported. Adding this option configures OpenSSL to support some weak ciphers that it would not use in the default configuration.
There is one place in parse_tls_serverhello() that returns 8 if the server's response is not well-formed TLS. However, there is no code in testssl.sh that is prepared to handle this return value. Every function except run_protocols() only distinguishes between 0, 2, and everything else. run_protocols(), however, gets confused if tls_sockets() returns a value that it is not expecting. So, this commit changes parse_tls_serverhello() to return 1 whenever the server's response can not be parsed.
There was a empty variable in determine_optimal_proto() which prevented to save
STARTTLS_OPTIMAL_PROTO. This is fixed.
The buffers and return codes for XMPP in starttls_io() were under not every
circumstances correct. This fixes those cases and making that in general more
robust (hopefully). (There's still code commented out which I'll leave it for
now).
When openssl did not support -starttls xmpp-server there was a copy
and paste error saying that -xmpphost option was not supported.
There is code at the beginning of parse_tls_serverhello() that checks whether the server's response appears to consist of a sequence of messages of the form <protocol><content type><content>. However, at the moment the check is only performed if "$do_starttls" is false. This commit changes parse_tls_serverhello() so that the check is always performed.
XMPP client-to-server and server-to-server links historically use
different XML namespaces. Some server implementations are strict
about this and will not proceed with the connection attempt when
the client namespace (`jabber:client`) is used on a
server-to-server link.
openssl s_client also supports `xmpp-server`.
This commit addresses two compatibility issues with LibreSSL 3.1.0, which has added client support for TLS 1.3.
The first issue is that LibreSSL has named the TLS 1.3 ciphers that it supports AEAD-AES256-GCM-SHA384, AEAD-CHACHA20-POLY1305-SHA256, and AEAD-AES128-GCM-SHA256, rather than using the OpenSSL names, which are TLS_AES_256_GCM_SHA384, TLS_CHACHA20_POLY1305_SHA256, and TLS_AES_128_GCM_SHA256. (Draft versions of OpenSSL 1.1.1 names these ciphers TLS13-AES-256-GCM-SHA384, TLS13-CHACHA20-POLY1305-SHA256, TLS13-AES-128-GCM-SHA256.) There are several places where testssl.sh checks whether a cipher suite is a TLS 1.3 cipher by checking whether its OpenSSL name begins with "TLS_" (or "TLS13"). In order to work with LibreSSL 3.1.0, these checks also need to consider names that begin with "AEAD-" to be TLS 1.3 ciphers.
Second, in sub_session_resumption() there is code that adds "-no_ssl2" to the "$OPENSSL s_client" command line if that option is supported. If "-no_ssl2" is not supported, then other protocol information is added to the command line. I believe this code was written with the assumption that any version of OpenSSL that supports "-no_ssl2" does not support TLS 1.3. However, LibreSSL 3.1.0 supports both. So, this commit changes the code to add the "-no_ssl2" option only if TLS 1.3 is not supported.
This commit addresses two compatibility issues with LibreSSL.
First, with LibreSSL, "$OPENSSL s_client" does not support the "-curves" option, so the "-groups" option needs to be used instead. Note that with LibreSSL, the command line "$OPENSSL s_client -groups $curve -connect invalid." will not work, as it will complain "no port defined," but will not indicate whether the specified curve is supported. Adding a port number fixes that problem. (There does not seem to be a need to include a port number for other tests, such as whether the "-curves" option itself is supported.)
Second, including "-out -" in the command line for "$OPENSSL genpkey" causes LibreSSL to create a file with the name "-" if the algorithm is supported. This is not an issue at the moment, since LibreSSL's genpkey does not support X25519 or X448. However, both genpkey with both OpenSSL and LibreSSL uses stdout as the default output if no "-out" is specified, so the "-out -" is not necessary.
generate_key_share_extension() and prepare_tls_clienthello() currently check the $OPENSSL version number to determine whether X25519 and X448 are supported. The commit changes these functions to use $HAS_X25519 and $HAS_X448.
run_ticketbleed() and sub_session_ticket_tls() each include one call to "$OPENSSL s_client". For each of these calls the expected response is a TLS 1.2 or earlier ServerHello. However, if $OPENSSL supports TLS 1.3, then a TLS 1.3 ClientHello will be sent.
This commit fixes this problem in two ways. For the call in run_ticketbleed(), "-no_tls1_3" is added to the command line if "$OPENSSL" supports TLS 1.3. For the call in sub_session_ticket_tls(), this commit changes the function so that the same ClientHello version is sent as will sent by run_ticketbleed() via sockets.
Dirk Wetter
David Cooper
Jonas Schäfer