Add a CHANGES entry for CVE-2019-1551
Changes between 1.1.1 and 3.0.0 [xx XXX xxxx]
+ *) Fixed an an overflow bug in the x64_64 Montgomery squaring procedure
+ used in exponentiation with 512-bit moduli. No EC algorithms are
+ affected. Analysis suggests that attacks against 2-prime RSA1024,
+ 3-prime RSA1536, and DSA1024 as a result of this defect would be very
+ difficult to perform and are not believed likely. Attacks against DH512
+ are considered just feasible. However, for an attack the target would
+ have to re-use the DH512 private key, which is not recommended anyway.
+ Also applications directly using the low level API BN_mod_exp may be
+ affected if they use BN_FLG_CONSTTIME.
+ (CVE-2019-1551)
+ [Andy Polyakov]
+
*) Introduced a new method type and API, OSSL_SERIALIZER, to
represent generic serializers. An implementation is expected to
be able to serialize an object associated with a given name (such
