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