[PATCH 01 of 20] Tests: separate SSL session reuse tests
Maxim Dounin
mdounin at mdounin.ru
Thu Mar 23 17:24:18 UTC 2023
Hello!
On Thu, Mar 23, 2023 at 07:59:41PM +0400, Sergey Kandaurov wrote:
> > On 23 Mar 2023, at 18:10, Maxim Dounin <mdounin at mdounin.ru> wrote:
> >
> > On Wed, Mar 22, 2023 at 12:57:56PM +0400, Sergey Kandaurov wrote:
> >
> >>> On 18 Mar 2023, at 18:14, Maxim Dounin <mdounin at mdounin.ru> wrote:
> >>>
> >>> # HG changeset patch
> >>> # User Maxim Dounin <mdounin at mdounin.ru>
> >>> # Date 1679105686 -10800
> >>> # Sat Mar 18 05:14:46 2023 +0300
> >>> # Node ID 86c394a226d2a7d463da7a1b7e88375c71c0c69b
> >>> # Parent 3c9aa6c23fc836725b96cf056d218217a5a81603
> >>> Tests: separate SSL session reuse tests.
> >>>
> >>> Instead of being mixed with generic SSL tests, session reuse variants
> >>> are now tested in a separate file.
> >>>
> >>> In the generic SSL tests only basic session reuse is now tested,
> >>> notably with session tickets enabled and a shared SSL session cache.
> >>> This should make it possible to reuse sessions in all cases (except
> >>> when it's not supported, such as with LibreSSL with TLSv1.3).
> >>>
> >>> Note that session reuse with tickets implies that $ssl_session_id
> >>> is selected by the client and therefore is not available on the
> >>> initial connection. Relevant test is modified to handle this.
> >>>
> >>> Further, BoringSSL does not use legacy session ID with TLSv1.3 even
> >>> if it is sent by the client. In contrast, OpenSSL always generates
> >>> an unique legacy session id, so it is available with TLSv1.3 even if
> >>> session resumption does not work (such as with old Net::SSLeay and
> >>> IO::Socket::SSL modules).
> >>
> >> Note that TLSv1.3 has only ticket based session resumption.
> >> BoringSSL has a different notion on using legacy session IDs
> >> in TLSv1.3, see tls13_create_session_with_ticket() in sources:
> >>
> >> // Historically, OpenSSL filled in fake session IDs for ticket-based sessions.
> >> // Envoy's tests depend on this, although perhaps they shouldn't.
> >> SHA256(CBS_data(&ticket), CBS_len(&ticket), session->session_id);
> >>
> >> Later, SSL_SESSION_get_id() was additionally annotated in ssl.h:
> >>
> >> // As a workaround for some broken applications, BoringSSL sometimes synthesizes
> >> // arbitrary session IDs for non-ID-based sessions. This behavior may be
> >> // removed in the future.
> >>
> >> As for TLSv1.3 server context, BoringSSL doesn't seem to use "session ID"
> >> besides echoing the client's legacy_session_id field content in the
> >> legacy_session_id_echo field of ServerHello/HRR during handshake,
> >> as mandated in RFC 8446, 4.1.3. So it doesn't settle in the session.
> >
> > Yes, that's basically what "BoringSSL does not use legacy session
> > ID with TLSv1.3..." sentence describes.
> >
> >>>
> >>> diff --git a/ssl.t b/ssl.t
> >>> --- a/ssl.t
> >>> +++ b/ssl.t
> >>> @@ -31,7 +31,7 @@ eval { IO::Socket::SSL::SSL_VERIFY_NONE(
> >>> plan(skip_all => 'IO::Socket::SSL too old') if $@;
> >>>
> >>> my $t = Test::Nginx->new()->has(qw/http http_ssl rewrite proxy/)
> >>> - ->has_daemon('openssl')->plan(28);
> >>> + ->has_daemon('openssl')->plan(21);
> >>>
> >>> $t->write_file_expand('nginx.conf', <<'EOF');
> >>>
> >>> @@ -47,7 +47,6 @@ http {
> >>>
> >>> ssl_certificate_key localhost.key;
> >>> ssl_certificate localhost.crt;
> >>> - ssl_session_tickets off;
> >>>
> >>> log_format ssl $ssl_protocol;
> >>>
> >>> @@ -59,6 +58,7 @@ http {
> >>> ssl_certificate_key inner.key;
> >>> ssl_certificate inner.crt;
> >>> ssl_session_cache shared:SSL:1m;
> >>> + ssl_session_tickets on;
> >>> ssl_verify_client optional_no_ca;
> >>>
> >>> keepalive_requests 1000;
> >>> @@ -100,57 +100,11 @@ http {
> >>> }
> >>>
> >>> server {
> >>> - listen 127.0.0.1:8081;
> >>> - server_name localhost;
> >>> -
> >>> - # Special case for enabled "ssl" directive.
> >>> -
> >>> - ssl on;
> >>
> >> Removing tests for the "ssl" legacy directive doesn't feel right
> >> now and is out of scope of this change. Please put this back.
> >> Not being able to test it is fragile and can be left silently
> >> broken, especially with the upcoming quic merge.
> >
> > It used to be tested as a side effect of session reuse tests, and
> > hence it is now gone.
>
> You are correct, yet it's useful to have it in some sort.
>
> > It is also tested at least in
> > ssl_reject_handshake.t, so I tend to think it is enough.
> >
>
> It is, though not very useful, at least now.
> Currently the tested configuration in ssl_reject_handshake.t is
> supplemented with "listen .. ssl" in adjacent virtual servers.
> If the "ssl" directive gets broken and e.g. will stop doing its work,
> the SSL mode will remain enabled across servers of the listening socket,
> so this may be left unnoticed.
> To make it more useful, we can remove "listen .. ssl" on virtual servers.
>
> # HG changeset patch
> # User Sergey Kandaurov <pluknet at nginx.com>
> # Date 1679586784 -14400
> # Thu Mar 23 19:53:04 2023 +0400
> # Node ID 938f2657257c24ac2ceb8df39536d330bcc03930
> # Parent 5abbc8e2d39dfda3913939a6ae293744f5f80933
> Tests: removed ssl from virtual servers in ssl_reject_handshake.t.
>
> In particular, this allows to test that the "ssl" directive actually works.
>
> diff --git a/ssl_reject_handshake.t b/ssl_reject_handshake.t
> --- a/ssl_reject_handshake.t
> +++ b/ssl_reject_handshake.t
> @@ -59,8 +59,8 @@ http {
> }
>
> server {
> - listen 127.0.0.1:8080 ssl;
> - listen 127.0.0.1:8081 ssl;
> + listen 127.0.0.1:8080;
> + listen 127.0.0.1:8081;
> server_name virtual;
>
> ssl_certificate localhost.crt;
> @@ -76,12 +76,12 @@ http {
> }
>
> server {
> - listen 127.0.0.1:8082 ssl;
> + listen 127.0.0.1:8082;
> server_name virtual1;
> }
>
> server {
> - listen 127.0.0.1:8082 ssl;
> + listen 127.0.0.1:8082;
> server_name virtual2;
>
> ssl_reject_handshake on;
Looks good (except the "virtual servers" term, see below).
> BTW, the old documentation on the "ssl" directive stated that it
> "Enables the HTTPS protocol for the given *virtual* server", though
> it appears to be rather opposite (i.e. for the default one).
The term "virtual server" includes everything virtual being run on
a given physical server, including IP-based, port-based, and
name-based virtual servers. The default server (for a listening
socket) is still a virtual server. See, for example, description
of the "server" directive:
http://nginx.org/en/docs/http/ngx_http_core_module.html#server
So, basically, the description of the "ssl" directive you are
referring to is perfectly correct. Except the fact that it might
additionally state that the directive only works if the server is
the default virtual server for the listening socket in question,
and does nothing in non-default virtual servers.
So a better commit log for the above patch should say that it
removes the "ssl" option from listening sockets in non-default
[virtual] servers. Something like this should be good enough:
: Tests: improved "ssl" directive test in ssl_reject_handshake.t.
:
: The "ssl" option was removed from listening sockets in non-default
: servers. In particular, this allows to test that the "ssl" directive
: actually works.
[...]
--
Maxim Dounin
http://mdounin.ru/
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