Changed to only include the signature algorithms extension for TLSv1.2, since RFC 5246 says:
Note: this extension is not meaningful for TLS versions prior to 1.2.
Clients MUST NOT offer it if they are offering prior versions.
However, even if clients do offer it, the rules specified in [TLSEXT]
require servers to ignore extensions they do not understand.
Inclusion of the extension for TLS 1.1 didn't seem to cause any harm, but it seems better to follow the RFC and not include it for TLSv1.0 or TLSv1.1.
RFC 7685 notes that there is at least one TLS implementation that hangs if the client sends a ClientHello with a TLSCiphertext.length between 256 and 511 bytes, and so the padding extension was defined in order to get around this bug. (OpenSSL s_client includes this extension when the -bugs option is used.) So, I changed socksend_tls_clienthello() to include the padding extension if the CLientHello would have a length between 256 and 511 bytes, making the padding extension just large enough to make the ClientHello 512 bytes.
I also fixed a typo (a missing "0x") in the check for whether any ECC ciphers are included in the Client Hello.
This PR adds the signature algorithms, heartbeat, session ticket, and next protocol extensions to the client hello message created by socksend_tls_clienthello() for TLS 1.0 and above. It also adds the supported elliptic curves and ec points format extensions if the client hello message includes any ECC cipher suites.
I tested this version against several servers with $EXPERIMENTAL set to true and get the same results as with the current code with $EXPERIMENTAL set to false.
The last line of neat_list currently uses $HEXC as the parameter to show_rfc_style(), but it should use $hexcode. At the moment using $HEXC instead of $hexcode makes no difference, since hexcode="$1" and in all calls to neat_list() the first parameter is $HEXC. However, this bug could create problems in the future since neat_list() will misbehave if the value of the first parameter (hexcode) isn't the same as $HEXC.
This PR makes basically the same changes to run_cipher_per_proto() as I previously made to run_allciphers(). The main difference is that in this function, round 0 consists of a single call to "$OPENSSL s_client" with "-cipher" including all of the locally supported ciphers. The reason for the difference is that in run_allciphers() its saves time to assume the server supports at least one cipher suite. In the case of run_cipher_per_proto(), however, it is likely that the server will not support some protocols at all, so its usually faster to start with a single call to "$OPENSSL s_client" that tests whether the server supports the protocol at all.
There is a tab on the line for SSL_CK_RC2_128_CBC_WITH_MD5. When testssl.sh is called with "-E" and "--show-each," this causes the string "not a/v" to be printed two characters to the right of the same string on every other line (at least on Linux systems). This PR just deletes the tab character.
The run_allciphers() function currently works by calling "$OPENSSL s_client" once for each cipher suite supported by $OPENSSL. In the case of "OpenSSL 1.0.2-chacha (1.0.2e-dev)" that means 195 calls to "$OPENSSL s_client" even though servers tend to only support a small fraction of these cipher suites.
This PR produces the same output as the current run_allciphers() with fewer calls to "$OPENSSL s_client", which results in the function running faster (usually much faster). The basic idea behind the revised function is to test cipher suites in blocks. If $OPENSSL supports 195 cipher suites, then it group these cipher suites into 4 blocks of 64 (with the final block being smaller). It makes one call to "$OPENSSL s_client" with cipher suites 1-64, and if it fails, then it knows that none of these 64 cipher suites are supported by the server and it doesn't need to perform any more tests on these 64 cipher suites. If it succeeds, then it breaks the 64 cipher suites into 4 blocks of 16 and calls "$OPENSSL s_client" with each of those blocks. The blocks of 16 that are successful are broken into blocks of 4, and for each of the successful blocks of 4 the individual cipher suites are tested.
For testssl.sh and www.google.com the number of calls to "$OPENSSL s_client" is reduced from 195 to 88. For github.com the number of calls is reduced to 56!
I haven't made any changes to run_cipher_per_proto yet, but if this PR is accepted I can make the same changes in that function.
Thanks,
David
* SHOW_EACH_C has now the correct logic
* pr_litemagenta ==> pr_warning
* fileout WARN according to pr_warning then changed appropiately
* some global vars in "" to avoid unneccessary shell expansion
* HAS_SSL2/HAS_SSL3 now works more reliably
* warning added in cipher order if ssl2/ssl3 is not supported by openssl
Dirk Wetter
David Cooper
Niko78
Thomas Patzke
Florian Baumann
Dave Cottlehuber