chore: checkpoint before Python removal

vendor/ring/crypto/mem.c

@@ -0,0 +1,28 @@
+// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <ring-core/mem.h>
+#include "internal.h"
+
+int CRYPTO_memcmp(const void *in_a, const void *in_b, size_t len) {
+  const aliasing_uint8_t *a = in_a;
+  const aliasing_uint8_t *b = in_b;
+  uint8_t x = 0;
+
+  for (size_t i = 0; i < len; i++) {
+    x |= a[i] ^ b[i];
+  }
+
+  return x;
+}