Public bug reported:

[Description]

Since OpenSSL 1.1.1 was backported to Bionic, some (all?) applications
gained access to TLS 1.3 by default. The applications that were not
rebuilt against OpenSSL 1.1.1 can't tune the TLS 1.3 settings (protocol,
ciphersuites selection, ciphersuites order) like it's possible with 1.2
and below. As such, one should turn to configuring /etc/ssl/openssl.cnf
to alter TLS 1.3 settings.

Here is how I'd expect to be able to turn off TLS 1.3:

# diff -Naur /etc/ssl/openssl.cnf{.orig,}
--- /etc/ssl/openssl.cnf.orig   2019-06-11 10:33:02.330143086 -0400
+++ /etc/ssl/openssl.cnf        2019-06-11 11:15:23.805113804 -0400
@@ -12,6 +12,16 @@
 HOME                   = .
 RANDFILE               = $ENV::HOME/.rnd
 
+ssl_conf = ssl_sect
+
+[ssl_sect]
+
+system_default = system_default_sect
+
+[system_default_sect]
+
+MaxProtocol = TLSv1.2
+
 # Extra OBJECT IDENTIFIER info:
 #oid_file              = $ENV::HOME/.oid
 oid_section            = new_oids

This doesn't work as 'openssl s_client -connect rproxy.sdeziel.info:443'
negotiates TLS 1.3 with TLS_AES_256_GCM_SHA384.


Similarly, trying to change the 'Ciphers' or the 'Ciphersuites' list with:

# diff -Naur /etc/ssl/openssl.cnf{.orig,}
--- /etc/ssl/openssl.cnf.orig   2019-06-11 10:33:02.330143086 -0400
+++ /etc/ssl/openssl.cnf        2019-06-11 11:37:23.362889367 -0400
@@ -12,6 +12,17 @@
 HOME                   = .
 RANDFILE               = $ENV::HOME/.rnd
 
+ssl_conf = ssl_sect
+
+[ssl_sect]
+
+system_default = system_default_sect
+
+[system_default_sect]
+
+Ciphers = TLS_AES_128_GCM_SHA256
+Ciphersuites = TLS_AES_128_GCM_SHA256
+
 # Extra OBJECT IDENTIFIER info:
 #oid_file              = $ENV::HOME/.oid
 oid_section            = new_oids

Doesn't work as s_client keeps negotiating TLS 1.3 with
TLS_AES_256_GCM_SHA384 (!= 128)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: openssl 1.1.1-1ubuntu2.1~18.04.1
ProcVersionSignature: Ubuntu 4.15.0-51.55-generic 4.15.18
Uname: Linux 4.15.0-51-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.9-0ubuntu7.6
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Tue Jun 11 11:22:47 2019
InstallationDate: Installed on 2018-07-15 (331 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180714)
ProcEnviron:
 LANG=en_CA.UTF-8
 TERM=xterm-256color
 SHELL=/bin/bash
 XDG_RUNTIME_DIR=<set>
 PATH=(custom, no user)
SourcePackage: openssl
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: openssl (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug bionic rls-ee-incoming

** Attachment added: "openssl.cnf trying to disable TLS 1.3"
   
https://bugs.launchpad.net/bugs/1832370/+attachment/5270156/+files/openssl.cnf

** Attachment removed: "ProcCpuinfoMinimal.txt"
   
https://bugs.launchpad.net/ubuntu/+source/openssl/+bug/1832370/+attachment/5270158/+files/ProcCpuinfoMinimal.txt

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to openssl in Ubuntu.
https://bugs.launchpad.net/bugs/1832370

Title:
  Unable to configure or disable TLS 1.3 via openssl.cnf

Status in openssl package in Ubuntu:
  New

Bug description:
  [Description]

  Since OpenSSL 1.1.1 was backported to Bionic, some (all?) applications
  gained access to TLS 1.3 by default. The applications that were not
  rebuilt against OpenSSL 1.1.1 can't tune the TLS 1.3 settings
  (protocol, ciphersuites selection, ciphersuites order) like it's
  possible with 1.2 and below. As such, one should turn to configuring
  /etc/ssl/openssl.cnf to alter TLS 1.3 settings.

  Here is how I'd expect to be able to turn off TLS 1.3:

  # diff -Naur /etc/ssl/openssl.cnf{.orig,}
  --- /etc/ssl/openssl.cnf.orig 2019-06-11 10:33:02.330143086 -0400
  +++ /etc/ssl/openssl.cnf      2019-06-11 11:15:23.805113804 -0400
  @@ -12,6 +12,16 @@
   HOME                 = .
   RANDFILE             = $ENV::HOME/.rnd
   
  +ssl_conf = ssl_sect
  +
  +[ssl_sect]
  +
  +system_default = system_default_sect
  +
  +[system_default_sect]
  +
  +MaxProtocol = TLSv1.2
  +
   # Extra OBJECT IDENTIFIER info:
   #oid_file            = $ENV::HOME/.oid
   oid_section          = new_oids

  This doesn't work as 'openssl s_client -connect
  rproxy.sdeziel.info:443' negotiates TLS 1.3 with
  TLS_AES_256_GCM_SHA384.

  
  Similarly, trying to change the 'Ciphers' or the 'Ciphersuites' list with:

  # diff -Naur /etc/ssl/openssl.cnf{.orig,}
  --- /etc/ssl/openssl.cnf.orig 2019-06-11 10:33:02.330143086 -0400
  +++ /etc/ssl/openssl.cnf      2019-06-11 11:37:23.362889367 -0400
  @@ -12,6 +12,17 @@
   HOME                 = .
   RANDFILE             = $ENV::HOME/.rnd
   
  +ssl_conf = ssl_sect
  +
  +[ssl_sect]
  +
  +system_default = system_default_sect
  +
  +[system_default_sect]
  +
  +Ciphers = TLS_AES_128_GCM_SHA256
  +Ciphersuites = TLS_AES_128_GCM_SHA256
  +
   # Extra OBJECT IDENTIFIER info:
   #oid_file            = $ENV::HOME/.oid
   oid_section          = new_oids

  Doesn't work as s_client keeps negotiating TLS 1.3 with
  TLS_AES_256_GCM_SHA384 (!= 128)

  ProblemType: Bug
  DistroRelease: Ubuntu 18.04
  Package: openssl 1.1.1-1ubuntu2.1~18.04.1
  ProcVersionSignature: Ubuntu 4.15.0-51.55-generic 4.15.18
  Uname: Linux 4.15.0-51-generic x86_64
  NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
  ApportVersion: 2.20.9-0ubuntu7.6
  Architecture: amd64
  CurrentDesktop: ubuntu:GNOME
  Date: Tue Jun 11 11:22:47 2019
  InstallationDate: Installed on 2018-07-15 (331 days ago)
  InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180714)
  ProcEnviron:
   LANG=en_CA.UTF-8
   TERM=xterm-256color
   SHELL=/bin/bash
   XDG_RUNTIME_DIR=<set>
   PATH=(custom, no user)
  SourcePackage: openssl
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/openssl/+bug/1832370/+subscriptions

-- 
Mailing list: https://launchpad.net/~touch-packages
Post to     : touch-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~touch-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to