bpo-33164: update blake2 implementation (GH-6286)

Author: David Carlier

Misc/NEWS.d/next/Security/2018-03-30-12-26-47.bpo-33164.aO29Cx.rst

@@ -0,0 +1 @@
+Updated blake2 implementation which uses secure memset implementation provided by platform.

Modules/_blake2/impl/blake2-config.h

@@ -1,23 +1,20 @@
 /*
    BLAKE2 reference source code package - optimized C implementations
 
-   Copyright 2012, Samuel Neves <[email protected]>.  You may use this under the
-   terms of the CC0, the OpenSSL Licence, or the Apache Public License 2.0, at
-   your option.  The terms of these licenses can be found at:
+   Written in 2012 by Samuel Neves <[email protected]>
 
-   - CC0 1.0 Universal : http://creativecommons.org/publicdomain/zero/1.0
-   - OpenSSL license   : https://www.openssl.org/source/license.html
-   - Apache 2.0        : http://www.apache.org/licenses/LICENSE-2.0
+   To the extent possible under law, the author(s) have dedicated all copyright
+   and related and neighboring rights to this software to the public domain
+   worldwide. This software is distributed without any warranty.
 
-   More information about the BLAKE2 hash function can be found at
-   https://blake2.net.
+   You should have received a copy of the CC0 Public Domain Dedication along with
+   this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
 */
 #pragma once
 #ifndef __BLAKE2_CONFIG_H__
 #define __BLAKE2_CONFIG_H__
 
-/* These don't work everywhere */
-#if defined(__SSE2__) || defined(__x86_64__) || defined(__amd64__)
+#if defined(__SSE2__)
 #define HAVE_SSE2
 #endif
 
@@ -26,7 +23,7 @@
 #endif
 
 #if defined(__SSE4_1__)
-#define HAVE_SSE41
+#define HAVE_SSE4_1
 #endif
 
 #if defined(__AVX__)
@@ -51,8 +48,8 @@
 #endif
 
 #ifdef HAVE_AVX
-#ifndef HAVE_SSE41
-#define HAVE_SSE41
+#ifndef HAVE_SSE4_1
+#define HAVE_SSE4_1
 #endif
 #endif