[ovs-dev] [PATCH v2 2/2] stream-ssl: Update default protocols, enable TLSv1.3
Flavio Leitner
fbl at sysclose.org
Thu Sep 9 20:05:26 UTC 2021
Hi Frode,
On Wed, Aug 25, 2021 at 01:05:14PM +0200, Frode Nordahl wrote:
> RFC 8996 [0] deprecates the use of TLSv1 and TLSv1.1 for security
> reasons. Update our default list of protcols to be in compliance.
>
> Also add TLSv1.3 to the default list of supported protocols.
>
> 0: https://datatracker.ietf.org/doc/html/rfc8996
> Signed-off-by: Frode Nordahl <frode.nordahl at canonical.com>
This patch does two things:
Deprecate TLSv1 and TLSv1.2
Add support for TLSv1.3
Can we split them into separate logical patches?
Also, shouldn't we first warn the users about deprecating
TLSv1 and TLSv1.1 for a release period, and then remove from
the default list in the next release? I mean, this is an user
visible change, so users might need some time to adapt.
What do you think?
fbl
> ---
> NEWS | 7 +++++++
> lib/ssl-connect.man | 6 ++++--
> lib/stream-ssl.c | 35 +++++++++++++++++++++++++++++------
> m4/openvswitch.m4 | 16 ++++++++++++++++
> tests/ovsdb-server.at | 6 ++----
> 5 files changed, 58 insertions(+), 12 deletions(-)
>
> diff --git a/NEWS b/NEWS
> index 1f2adf718..502e6693a 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -8,6 +8,13 @@ Post-v2.16.0
> by default. 'other_config:dpdk-socket-limit' can be set equal to
> the 'other_config:dpdk-socket-mem' to preserve the legacy memory
> limiting behavior.
> + - Update default configuration for enabled TLS protocols:
> + * RFC 8996 deprecates the use of TLSv1 and TLSv1.1 for security reasons.
> + * Add TLSv1.3 to the default list of enabled protocols when the built with
> + OpenSSL v1.1.1 and newer.
> + * The new default is as such: TLSv1.2,TLSv1.3
> + * As a consequence we no longer support building Open vSwitch with OpenSSL
> + versions without TLSv1.2 support.
>
>
> v2.16.0 - 16 Aug 2021
> diff --git a/lib/ssl-connect.man b/lib/ssl-connect.man
> index 6e54f77ef..0dd5a29be 100644
> --- a/lib/ssl-connect.man
> +++ b/lib/ssl-connect.man
> @@ -1,10 +1,12 @@
> .IP "\fB\-\-ssl\-protocols=\fIprotocols\fR"
> Specifies, in a comma- or space-delimited list, the SSL protocols
> \fB\*(PN\fR will enable for SSL connections. Supported
> -\fIprotocols\fR include \fBTLSv1\fR, \fBTLSv1.1\fR, and \fBTLSv1.2\fR.
> +\fIprotocols\fR include \fBTLSv1.2\fR and \fBTLSv1.3\fR depending on
> +which version of OpenSSL Open vSwitch is built with.
> Regardless of order, the highest protocol supported by both sides will
> be chosen when making the connection. The default when this option is
> -omitted is \fBTLSv1,TLSv1.1,TLSv1.2\fR.
> +omitted is \fBTLSv1.2,TLSv1.3\fR if built with a version of OpenSSL that
> +supports \fBTLSv1.3\fR.
> .
> .IP "\fB\-\-ssl\-ciphers=\fIciphers\fR"
> Specifies, in OpenSSL cipher string format, the ciphers \fB\*(PN\fR will
> diff --git a/lib/stream-ssl.c b/lib/stream-ssl.c
> index 6b4cf6970..954067787 100644
> --- a/lib/stream-ssl.c
> +++ b/lib/stream-ssl.c
> @@ -162,7 +162,13 @@ struct ssl_config_file {
> static struct ssl_config_file private_key;
> static struct ssl_config_file certificate;
> static struct ssl_config_file ca_cert;
> -static char *default_ssl_protocols = "TLSv1,TLSv1.1,TLSv1.2";
> +/* RFC 8996 deprecates the use of TLSv1 and TLSv1.1, users may still specify
> + * them in their configuration, but our defaults are in compliance. */
> +#if OPENSSL_VERSION_NUMBER < 0x10101000L
> +static char *default_ssl_protocols = "TLSv1.2";
> +#else
> +static char *default_ssl_protocols = "TLSv1.2,TLSv1.3";
> +#endif /* OPENSSL_VERSION_NUMBER < 0x10101000L */
> static char *default_ssl_ciphers = "HIGH:!aNULL:!MD5";
> static char *ssl_protocols = NULL;
> static char *ssl_ciphers = NULL;
> @@ -1255,9 +1261,18 @@ stream_ssl_set_protocols(const char *arg)
> return;
> }
>
> + /* TODO: Using SSL_CTX_set_options to enable individual protocol versions
> + * is deprecated as of OpenSSL v1.1.0. Once we can drop support for builds
> + * with OpenSSL pre v1.1.0 we should use SSL_CTX_set_min_proto_version and
> + * SSL_CTX_set_max_proto_version instead. */
> +
> /* Start with all the flags off and turn them on as requested. */
> #ifndef SSL_OP_NO_SSL_MASK
> - /* For old OpenSSL without this macro, this is the correct value. */
> + /* For old OpenSSL without this macro, this is the correct value.
> + *
> + * NOTE: We deliberately did not extend this compatibility macro to
> + * include SSL_OP_NO_TLSv1_3 because if you do have a version of OpenSSL
> + * with TLSv1.3 support this macro would be defined by OpenSSL. */
> #define SSL_OP_NO_SSL_MASK (SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | \
> SSL_OP_NO_TLSv1 | SSL_OP_NO_TLSv1_1 | \
> SSL_OP_NO_TLSv1_2)
> @@ -1272,12 +1287,20 @@ stream_ssl_set_protocols(const char *arg)
> goto exit;
> }
> while (word != NULL) {
> - long on_flag;
> - if (!strcasecmp(word, "TLSv1.2")){
> + long on_flag = 0;
> + if (!strcasecmp(word, "TLSv1.3")) {
> +#if OPENSSL_VERSION_NUMBER < 0x10101000L
> + /* OpenSSL versions prior to 1.1.1 do not have TLSv1.3 */
> + VLOG_ERR("%s: SSL protocol not recognized", word);
> + goto exit;
> +#else
> + on_flag = SSL_OP_NO_TLSv1_3;
> +#endif /* OPENSSL_VERSION_NUMBER < 0x10101000 */
> + } else if (!strcasecmp(word, "TLSv1.2")) {
> on_flag = SSL_OP_NO_TLSv1_2;
> - } else if (!strcasecmp(word, "TLSv1.1")){
> + } else if (!strcasecmp(word, "TLSv1.1")) {
> on_flag = SSL_OP_NO_TLSv1_1;
> - } else if (!strcasecmp(word, "TLSv1")){
> + } else if (!strcasecmp(word, "TLSv1")) {
> on_flag = SSL_OP_NO_TLSv1;
> } else {
> VLOG_ERR("%s: SSL protocol not recognized", word);
> diff --git a/m4/openvswitch.m4 b/m4/openvswitch.m4
> index 772825a71..429aacd11 100644
> --- a/m4/openvswitch.m4
> +++ b/m4/openvswitch.m4
> @@ -257,6 +257,22 @@ OpenFlow connections over SSL will not be supported.
> else
> AC_MSG_ERROR([Cannot find openssl (use --disable-ssl to configure without SSL support)])
> fi])
> + OPENSSL_SUPPORTS_TLS1_2=no
> + if test $HAVE_OPENSSL = yes; then
> + save_CPPFLAGS=$CPPFLAGS
> + CPPFLAGS="$CPPFLAGS $SSL_INCLUDES"
> + AC_CHECK_DECL([TLS1_2_VERSION], [OPENSSL_SUPPORTS_TLS1_2=yes],
> + [], [#include <openssl/ssl.h>])
> + if test $OPENSSL_SUPPORTS_TLS1_2 = no; then
> + if test "$ssl" = check; then
> + AC_MSG_WARN([Cannot find openssl with TLSv1.2 support. OpenFlow connections over SSL will not be supported. (You may use --disable-ssl to suppress this warning.)])
> + HAVE_OPENSSL=no
> + else
> + AC_MSG_ERROR([Cannot find openssl with TLSv1.2 support. (use --disable-ssl to configure without SSL support)])
> + fi
> + fi
> + CPPFLAGS=$save_CPPFLAGS
> + fi
> else
> HAVE_OPENSSL=no
> fi
> diff --git a/tests/ovsdb-server.at b/tests/ovsdb-server.at
> index ac243d6a7..b52ca150c 100644
> --- a/tests/ovsdb-server.at
> +++ b/tests/ovsdb-server.at
> @@ -575,7 +575,6 @@ AT_CHECK(
> "row": {"private_key": "'"$PKIDIR/testpki-privkey2.pem"'",
> "certificate": "'"$PKIDIR/testpki-cert2.pem"'",
> "ca_cert": "'"$PKIDIR/testpki-cacert.pem"'",
> - "ssl_protocols": "'"TLSv1.2,TLSv1.1"'",
> "ssl_ciphers": "'"HIGH:!aNULL:!MD5:!ECDHE-ECDSA-AES256-GCM-SHA384"'"}}]']],
> [0], [ignore], [ignore])
> on_exit 'kill `cat *.pid`'
> @@ -594,7 +593,6 @@ AT_CHECK(
> --private-key=$PKIDIR/testpki-privkey.pem \
> --certificate=$PKIDIR/testpki-cert.pem \
> --ca-cert=$PKIDIR/testpki-cacert.pem \
> - --ssl-protocols=TLSv1.2,TLSv1.1 \
> --ssl-ciphers=HIGH:!aNULL:!MD5 \
> transact ssl:127.0.0.1:$SSL_PORT \
> '["mydb",
> @@ -608,7 +606,7 @@ AT_CHECK_UNQUOTED(
> [cat output], [0],
> [[@<:@{"rows":@<:@{"private_key":"$PKIDIR/testpki-privkey2.pem"}@:>@}@:>@
> ]], [ignore])
> -# Check that when the server has TLSv1.1+ and the client has
> +# Check that when the server has TLSv1.2+ and the client has
> # TLSv1 that the connection fails.
> AT_CHECK(
> [[ovsdb-client \
> @@ -638,7 +636,7 @@ AT_CHECK(
> --private-key=$PKIDIR/testpki-privkey.pem \
> --certificate=$PKIDIR/testpki-cert.pem \
> --ca-cert=$PKIDIR/testpki-cacert.pem \
> - --ssl-protocols=TLSv1.2,TLSv1.1 \
> + --ssl-protocols=TLSv1.2 \
> --ssl-ciphers=ECDHE-ECDSA-AES256-GCM-SHA384 \
> transact ssl:127.0.0.1:$SSL_PORT \
> '["mydb",
> --
> 2.32.0
>
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
--
fbl
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