Use SecKeyCreateSignature on macOS 10.12 and later.

net/ssl/ssl_private_key_test_util.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_SSL_SSL_PRIVATE_KEY_TEST_UTIL_H_
+#define NET_SSL_SSL_PRIVATE_KEY_TEST_UTIL_H_
+
+#include <string>
+
+#include "net/ssl/ssl_private_key.h"
+
+namespace net {
+
+const char* SSLPrivateKeyTypeToString(SSLPrivateKey::Type type);

[Ryan Sleevi, 2016/12/13 22:21:08]

const char* const ?

[davidben, 2016/12/14 00:59:43]

Returning const out of a function doesn't actually do anything useful. (In fact,
I believe I've seen MSVC explode if you do it.) The first const says something
about what the pointer is pointing to. The second says you can't modify the
value of the pointer... but the pointer value is an rvalue anyway, so that
doesn't really mean anything.

+
+// Tests that |key| matches the private key serialized in |pkcs8| on all
+// properties and advertised signature algorithms. The caller is responsible for

[Ryan Sleevi, 2016/12/13 22:21:08]

From reading only this header, I'm not sure what "on all properties" means?

[davidben, 2016/12/14 00:59:43]

Rephrased to be more explicit.

+// asserting that |key|'s advertised algorithms are as expected.
+void TestSSLPrivateKeyMatches(SSLPrivateKey* key, const std::string& pkcs8);
+
+}  // namespace net
+
+#endif  // NET_SSL_SSL_PRIVATE_KEY_TEST_UTIL_H_