Ubuntu
openssl package

  1. Bug #1797386
  2. Comment #13

Comment 13 for bug 1797386

Revision history for this message
Dimitri John Ledkov (xnox) wrote : Re: [Bug 1797386] Re: [SRU] OpenSSL 1.1.1 to 18.04 LTS

On Mon, 11 Mar 2019 at 21:20, Steve Langasek
<email address hidden> wrote:
>
> Acceptance of openssl currently blocked on coverage of the (distro
> patch) OPENSSL_TLS_SECURITY_LEVEL change as part of the SRU template.
>

In Debian (but never ubuntu) they have bumped the default security
level from 1, to 2.

In Ubuntu, we have further decreased security level from 1 to 0, for
connectivity compatibility with openssl 1.0.2. This change was done in
cosmic, and is part of this SRU backport.

The reason for the decreased security level is to aid with
connectivity compatibily with older Ubuntu LTS releases based on
openssl 1.0.2. Such that bionic clients can connect to older servers,
even if the server uses small keys / md5 / etc.

I do not believe it is possible to set higher default security level
"for servers only". Thus we rely on server/daemon apps to have
stronger configuration, large keys, better certs, etc.

There are 1.1.0/1.1.1 APIs available to dynamically set higher
security levels, which highly active servers are using to increase
security levels in servers/daemons.

These changes are documented in the cosmic+ changelog with the
following entries:
- Revert "Enable system default config to enforce TLS1.2 as a
  minimum" & "Increase default security level from 1 to 2".
- Further decrease security level from 1 to 0, for compatibility with
  openssl 1.0.2.

Migration path to stonger defaults is to be done in 2020. This is
inline with major web-browsers too. All of them still support weaker
defaults. And all of them however have committed to drop support for
those in 2020. My expectation is to follow suit, and set default
security level to 2, and require TLS1.2 shortly after 19.10 release.

For the webbrowsers announcements please see these references:
https://blogs.windows.com/msedgedev/2018/10/15/modernizing-tls-edge-ie11/
https://webkit.org/blog/8462/deprecation-of-legacy-tls-1-0-and-1-1-versions/
https://security.googleblog.com/2018/10/modernizing-transport-security.html
https://blog.mozilla.org/security/2018/10/15/removing-old-versions-of-tls/

--
Regards,

Dimitri.