Commit 4933e83f32 for openssl.org

commit 4933e83f3234f6a54af2f9af16393524f94a087e
Author: Dmitry Belyavskiy <beldmit@gmail.com>
Date:   Sat Jan 17 13:57:34 2026 +0100

    Deprecate support of weak elliptic curves in TLS by default

    See RFC 8422, section 5.1.1

    Reviewed-by: Alicja Kario <hkario@redhat.com>
    Reviewed-by: Eugene Syromiatnikov <esyr@openssl.org>
    Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
    Reviewed-by: Tomas Mraz <tomas@openssl.org>
    Reviewed-by: Paul Dale <paul.dale@oracle.com>
    MergeDate: Thu Jan 22 10:00:08 2026
    (Merged from https://github.com/openssl/openssl/pull/29658)

diff --git a/CHANGES.md b/CHANGES.md
index 5f6a1f947b..757cea73ec 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -37,6 +37,12 @@ OpenSSL 4.0

    *Shane Lontis*

+ * Support of deprecated elliptic curves in TLS according to RFC 8422 was
+   disabled at compile-time by default. To enable it, use the
+   `enable-tls-deprecated-ec` compilation option.
+
+   *Dmitry Belyavskiy*
+
  * Remove support for an SSLv2 Client Hello. When a client wanted to support
    both SSLv2 and higher versions like SSLv3 or even TLSv1, it needed to
    send an SSLv2 Client Hello. SSLv2 support itself was removed in version
diff --git a/Configure b/Configure
index 3e9385ea4e..efded13f3e 100755
--- a/Configure
+++ b/Configure
@@ -628,6 +628,7 @@ our %disabled = ( # "what"         => "comment"
                   "sctp"                => "default",
                   "sslkeylog"           => "default",
                   "tfo"                 => "default",
+                  "tls-deprecated-ec"   => "default",
                   "trace"               => "default",
                   "ubsan"               => "default",
                   "unit-test"           => "default",
diff --git a/INSTALL.md b/INSTALL.md
index c911ab90ea..9a21f72db8 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -757,9 +757,9 @@ Don't build and install documentation, i.e. manual pages in various forms.

 Don't build support for loading Dynamic Shared Objects (DSO)

-### no-tls-deprecated-ec
+### enable-tls-deprecated-ec

-Disable legacy TLS EC groups that were deprecated in RFC8422.  These are the
+Enable legacy TLS EC groups that were deprecated in RFC8422.  These are the
 Koblitz curves, B<secp160r1>, B<secp160r2>, B<secp192r1>, B<secp224r1>, and the
 binary Elliptic curves that would also be disabled by C<no-ec2m>.