Add support for encrypted WebM files as defined in the RFC.

media/webm/webm_content_encodings_client.cc

 // Copyright (c) 2012 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.
 
 #include "media/webm/webm_content_encodings_client.h"
 
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "media/webm/webm_constants.h"
 
@@ skipping 32 matching lines @@
   if (id == kWebMIdContentEncryption) {
     DCHECK(cur_content_encoding_.get());
     if (content_encryption_encountered_) {
       DVLOG(1) << "Unexpected multiple ContentEncryption.";
       return NULL;
     }
     content_encryption_encountered_ = true;
     return this;
   }
 
+  if (id == kWebMIdContentEncAESSettings) {
+    DCHECK(cur_content_encoding_.get());
+    return this;
+  }
+
   // This should not happen if WebMListParser is working properly.
   DCHECK(false);
   return NULL;
 }
 
 // Mandatory occurrence restriction is checked in this function. Multiple
 // occurrence restriction is checked in OnUInt and OnBinary.
 bool WebMContentEncodingsClient::OnListEnd(int id) {
   if (id == kWebMIdContentEncodings) {
     // ContentEncoding element is mandatory. Check this!
@@ skipping 51 matching lines @@
     DCHECK(cur_content_encoding_.get());
     // Specify default value for elements that are not present.
     if (cur_content_encoding_->encryption_algo() ==
         ContentEncoding::kEncAlgoInvalid) {
       cur_content_encoding_->set_encryption_algo(
           ContentEncoding::kEncAlgoNotEncrypted);
     }
     return true;
   }
 
+  if (id == kWebMIdContentEncAESSettings) {
+    if (cur_content_encoding_->cipher_mode() ==
+        ContentEncoding::kCipherModeInvalid)
+      cur_content_encoding_->set_cipher_mode(ContentEncoding::kCipherModeCtr);
+    return true;
+  }
+
   // This should not happen if WebMListParser is working properly.
   DCHECK(false);
   return false;
 }
 
 // Multiple occurrence restriction and range are checked in this function.
 // Mandatory occurrence restriction is checked in OnListEnd.
 bool WebMContentEncodingsClient::OnUInt(int id, int64 val) {
   DCHECK(cur_content_encoding_.get());
 
@@ skipping 65 matching lines @@
         val > ContentEncoding::kEncAlgoAes) {
       DVLOG(1) << "Unexpected ContentEncAlgo " << val << ".";
       return false;
     }
 
     cur_content_encoding_->set_encryption_algo(
         static_cast<ContentEncoding::EncryptionAlgo>(val));
     return true;
   }
 
+  if (id == kWebMIdAESSettingsCipherMode) {
+    if (cur_content_encoding_->cipher_mode() !=
+        ContentEncoding::kCipherModeInvalid) {
+      DVLOG(1) << "Unexpected multiple AESSettingsCipherMode.";
+      return false;
+    }
+
+    if (val != ContentEncoding::kCipherModeCtr) {
+      DVLOG(1) << "Unexpected AESSettingsCipherMode " << val << ".";
+      return false;
+    }
+
+    cur_content_encoding_->set_cipher_mode(
+        static_cast<ContentEncoding::CipherMode>(val));
+    return true;
+  }
+
   // This should not happen if WebMListParser is working properly.
   DCHECK(false);
   return false;
 }
 
 // Multiple occurrence restriction is checked in this function.  Mandatory
 // restriction is checked in OnListEnd.
 bool WebMContentEncodingsClient::OnBinary(int id, const uint8* data, int size) {
   DCHECK(cur_content_encoding_.get());
   DCHECK(data);
   DCHECK_GT(size, 0);
 
   if (id == kWebMIdContentEncKeyID) {
     if (cur_content_encoding_->encryption_key_id() ||
         cur_content_encoding_->encryption_key_id_size()) {
       DVLOG(1) << "Unexpected multiple ContentEncKeyID";
       return false;
     }
     cur_content_encoding_->SetEncryptionKeyId(data, size);
     return true;
   }
 
   // This should not happen if WebMListParser is working properly.
   DCHECK(false);
   return false;
 }
 
 }  // namespace media