[Bug 1797386] Re: [SRU] OpenSSL 1.1.1 to 18.04 LTS

[Dr. Uwe Meyer-Gruhl]

Hi,

good idea in theory, but I want to add my 2cents: Please coordinate this
update with ALL affected packages, like apache2 and nginx.

My reason is:

I just tried the PPA and found that nginx works with TLS 1.3 after that
right out of the box.

HOWEVER, there is a problem: openssl 1.1.1 has changed the way the
cipher suites are configured - the ones for TLS 1.3 are configured
separately, see here:

https://github.com/openssl/openssl/commit/f865b08143b453962ad4afccd69e698d13c60f77

Nginx on the other hand has chosen to not support that new configuration
at all, see:

https://trac.nginx.org/nginx/ticket/1529

That means that the predefined order of TLS 1.3 is:

TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256

and cannot be changed - it took me hours to find that out since the
Nginx 1.15 documentation does not tell you that the TLS 1.3 ciphers
cannot be changed by ssl_ciphers, but are silently ignored.


The default set and order of ciphersuites may suit your needs or not -
matter-of-fact it makes my SSLLabs score worse because of the AES128
cipher used. I have tried to apply othe defaults in
/etc/ssl/openssl.conf but they do not seem to work for nginx. Neither
could I just disable TLS 1.3 in order to restore the old behaviour other
than to restore OpenSSL 1.1.0 by using "ppa-purge ppa:ci-train-ppa-
service/3473".


King regards,


Uwe


** Bug watch added: trac.nginx.org/nginx/ #1529
   http://trac.nginx.org/nginx/ticket/1529

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https://bugs.launchpad.net/bugs/1797386

Title:
  [SRU] OpenSSL 1.1.1 to 18.04 LTS

Status in openssl package in Ubuntu:
  In Progress
Status in libio-socket-ssl-perl source package in Bionic:
  New
Status in libnet-ssleay-perl source package in Bionic:
  New
Status in nova source package in Bionic:
  New
Status in openssl source package in Bionic:
  New
Status in python-cryptography source package in Bionic:
  New
Status in python2.7 source package in Bionic:
  New
Status in python3.6 source package in Bionic:
  New
Status in python3.7 source package in Bionic:
  New
Status in r-cran-openssl source package in Bionic:
  Fix Committed
Status in ruby-openssl source package in Bionic:
  Fix Committed
Status in ruby2.5 source package in Bionic:
  New

Bug description:
  [Impact]

   * OpenSSL 1.1.1 is an LTS release upstream, which will continue to
  receive security support for much longer than 1.1.0 series will.

   * OpenSSL 1.1.1 comes with support for TLS v1.3 which is expected to
  be rapidly adopted due to increased set of supported hashes & algoes,
  as well as improved handshake [re-]negotiation.

   * OpenSSL 1.1.1 comes with improved hw-acceleration capabilities.

   * OpenSSL 1.1.1 is ABI/API compatible with 1.1.0, however some
  software is sensitive to the negotiation handshake and may either need
  patches/improvements or clamp-down to maximum v1.2.

  [Test Case]

   * Rebuild all reverse dependencies

   * Execute autopkg tests for all of them

   * Clamp down to TLS v1.2 software that does not support TLS v1.3
  (e.g. mongodb)

   * Backport TLS v1.3 support patches, where applicable

  [Regression Potential]

   * Connectivity interop is the biggest issues which will be
  unavoidable with introducing TLS v1.3. However, tests on cosmic
  demonstrate that curl/nginx/google-chrome/mozilla-firefox connect and
  negotiate TLS v1.3 without issues.

   * Mitigation of discovered connectivity issues will be possible by
  clamping down to TLS v1.2 in either server-side or client-side
  software or by backporting relevant support fixes

   * Notable changes are listed here
  https://wiki.openssl.org/index.php/TLS1.3

   * Most common connectivity issues so far:
     - client verifies SNI in TLSv1.3 mode, yet client doesn't set hostname. Solution is client change to set hostname, or to clamp down the client to TLSv1.2.

     - session negotiation is different in TLSv1.3, existing client code
  may fail to create/negotiate/resume session. Clients need to learn how
  to use session callback.

   * This update bundles python 3.6 and 3.7 point releases

  [Other Info]

   * Previous FFe for OpenSSL in 18.10 is at
     https://bugs.launchpad.net/ubuntu/+source/openssl/+bug/1793092

   * TLS v1.3 support in NSS is expected to make it to 18.04 via
  security updates

   * TLS v1.3 support in GnuTLS is expected to be available in 19.04

   * Test OpenSSL is being prepared in
     https://launchpad.net/~ci-train-ppa-service/+archive/ubuntu/3473

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