Add CHANGES/NEWS for CVE-2023-3817

Reviewed-by: NPaul Dale <pauli@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21551)
Signed-off-by: Ncode4lala <fengziteng2@huawei.com>

CHANGES

@@ -6,6 +6,22 @@
  For a full list of changes, see the git commit log; for example,
  https://github.com/openssl/openssl/commits/ and pick the appropriate
  release branch.
+ *) Fix excessive time spent checking DH q parameter value.
+
+    The function DH_check() performs various checks on DH parameters. After
+    fixing CVE-2023-3446 it was discovered that a large q parameter value can
+    also trigger an overly long computation during some of these checks.
+    A correct q value, if present, cannot be larger than the modulus p
+    parameter, thus it is unnecessary to perform these checks if q is larger
+    than p.
+
+    If DH_check() is called with such q parameter value,
+    DH_CHECK_INVALID_Q_VALUE return flag is set and the computationally
+    intensive checks are skipped.
+
+    (CVE-2023-3817)
+    [Tomáš Mráz]
+
  *) Fix DH_check() excessive time with over sized modulus
 
     The function DH_check() performs various checks on DH parameters. One of

NEWS

@@ -4,6 +4,7 @@
 
   This file gives a brief overview of the major changes between each OpenSSL
   release. For more details please read the CHANGES file.
+      o Fix excessive time spent checking DH q parameter value (CVE-2023-3817)
       o Fix DH_check() excessive time with over sized modulus (CVE-2023-3446)
       o Fixed documentation of X509_VERIFY_PARAM_add0_policy() (CVE-2023-0466)
       o Mitigate for very slow `OBJ_obj2txt()` performance with gigantic