Add a ClientKeyStore to allow injection of non-platform keys for TLS client auth.

net/ssl/client_key_store.h

+// Copyright 2015 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_CLIENT_KEY_STORE_H_
+#define NET_SSL_CLIENT_KEY_STORE_H_
+
+#include <map>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "net/base/net_export.h"
+
+namespace net {
+
+class SSLPrivateKey;
+class X509Certificate;
+
+// TODO(rsleevi, davidben): Remove this once https://crbug.com/394131 is fixed.
+// A certificate and key store that allows several external certificate
+// providers to push certificates and keys into this store. All currently
+// provided certificates will be exposed through |FetchClientCertPrivateKey|.
+// Methods of this singleton can be called from any thread.
+class NET_EXPORT ClientKeyStore {
+ public:
+  class CertKeyProvider {
+   public:
+    // This can be called from any thread.
+    virtual ~CertKeyProvider() {}
+
+    // Obtains a handle to the certificate private key for |cert| and stores it
+    // in |private_key|.
+    // If the CertKeyProvider does not know about the |cert|, returns false. If
+    // it knows about the certificate, but is unable to return the private key,
+    // returns true and sets |*private_key| to nullptr.
+    // This can be called from any thread.
+    virtual bool GetCertificateKey(const X509Certificate& cert,
+                                   scoped_ptr<SSLPrivateKey>* private_key) = 0;
+  };
+
+  static ClientKeyStore* GetInstance();
+
+  // The |provider| will be accessed and destroyed on any thread but no

[mattm, 2015/08/21 23:18:17]

Comment about what thread |provider| will be destroyed on should be removed too.

[pneubeck (no reviews), 2015/08/24 10:08:06]

Done.

+  // concurrent method invocations will happen.
+  // |provider| must be valid until it is removed using |RemoveProvider| or the
+  // store is destroyed.
+  void AddProvider(CertKeyProvider* provider);
+
+  void RemoveProvider(const CertKeyProvider* provider);
+
+  // Given a |certificate|'s public key, return the corresponding private
+  // key if any of the registered providers has a matching key.
+  // Returns its matching private key on success, nullptr otherwise.
+  scoped_ptr<SSLPrivateKey> FetchClientCertPrivateKey(
+      const X509Certificate& certificate);
+
+ private:
+  friend struct base::DefaultLazyInstanceTraits<ClientKeyStore>;
+
+  ClientKeyStore();
+  ~ClientKeyStore();
+
+  base::Lock lock_;
+  std::vector<CertKeyProvider*> providers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ClientKeyStore);
+};
+
+}  // namespace net
+
+#endif  // NET_SSL_CLIENT_KEY_STORE_H_