This change integrates the FrameEncryptorInterface and the

FrameDecryptorInterface into the public WebRTC API surface.

This change just addresses the headers and not the internal changes.

Bug: webrtc:9681
Change-Id: I1db0172fe55ba378f62e7781c2b7dcdb93d63239
Reviewed-on: https://webrtc-review.googlesource.com/96622
Commit-Queue: Benjamin Wright <benwright@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24488}

api/crypto/frameencryptorinterface.h

@@ -0,0 +1,50 @@
+/*
+ *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef API_CRYPTO_FRAMEENCRYPTORINTERFACE_H_
+#define API_CRYPTO_FRAMEENCRYPTORINTERFACE_H_
+
+#include "api/array_view.h"
+#include "api/mediatypes.h"
+#include "rtc_base/refcount.h"
+
+namespace webrtc {
+
+// FrameEncryptorInterface allows users to provide a custom encryption
+// implementation to encrypt all outgoing audio and video frames. The user must
+// also provide a FrameDecryptorInterface to be able to decrypt the frames on
+// the receiving device. Note this is an additional layer of encryption in
+// addition to the standard SRTP mechanism and is not intended to be used
+// without it. Implementations of this interface will have the same lifetime as
+// the RTPSenders it is attached to.
+// This interface is not ready for production use.
+class FrameEncryptorInterface : public rtc::RefCountInterface {
+ public:
+  virtual ~FrameEncryptorInterface() {}
+
+  // Attempts to encrypt the provided frame. You may assume the encrypted_frame
+  // will match the size returned by GetOutputSize for a give frame. You may
+  // assume that the frames will arrive in order if SRTP is enabled. The ssrc
+  // will simply identify which stream the frame is travelling on.
+  // TODO(benwright) integrate error codes.
+  virtual bool Encrypt(cricket::MediaType media_type,
+                       uint32_t ssrc,
+                       rtc::ArrayView<const uint8_t> frame,
+                       rtc::ArrayView<uint8_t> encrypted_frame) = 0;
+
+  // Returns the total required length in bytes for the output of the
+  // encryption.
+  virtual size_t GetOutputSize(cricket::MediaType media_type,
+                               size_t frame_size) = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // API_CRYPTO_FRAMEENCRYPTORINTERFACE_H_