<divclass="fragment"><divclass="line"><aname="l00001"></a><spanclass="lineno"> 1</span> <spanclass="comment">// Copyright 2014 The Chromium Authors. All rights reserved.</span></div><divclass="line"><aname="l00002"></a><spanclass="lineno"> 2</span> <spanclass="comment">// Use of this source code is governed by a BSD-style license that can be</span></div><divclass="line"><aname="l00003"></a><spanclass="lineno"> 3</span> <spanclass="comment">// found in the LICENSE file.</span></div><divclass="line"><aname="l00004"></a><spanclass="lineno"> 4</span> </div><divclass="line"><aname="l00005"></a><spanclass="lineno"> 5</span> <spanclass="preprocessor">#include "packager/media/formats/webm/webm_crypto_helpers.h"</span></div><divclass="line"><aname="l00006"></a><spanclass="lineno"> 6</span> </div><divclass="line"><aname="l00007"></a><spanclass="lineno"> 7</span> <spanclass="preprocessor">#include "packager/base/logging.h"</span></div><divclass="line"><aname="l00008"></a><spanclass="lineno"> 8</span> <spanclass="preprocessor">#include "packager/base/sys_byteorder.h"</span></div><divclass="line"><aname="l00009"></a><spanclass="lineno"> 9</span> <spanclass="preprocessor">#include "packager/media/base/buffer_reader.h"</span></div><divclass="line"><aname="l00010"></a><spanclass="lineno"> 10</span> <spanclass="preprocessor">#include "packager/media/formats/webm/webm_constants.h"</span></div><divclass="line"><aname="l00011"></a><spanclass="lineno"> 11</span> </div><divclass="line"><aname="l00012"></a><spanclass="lineno"> 12</span> <spanclass="keyword">namespace </span><aclass="code"href="../../d8/daf/namespaceshaka.html">shaka</a> {</div><divclass="line"><aname="l00013"></a><spanclass="lineno"> 13</span> <spanclass="keyword">namespace </span>media {</div><divclass="line"><aname="l00014"></a><spanclass="lineno"> 14</span> <spanclass="keyword">namespace </span>{</div><divclass="line"><aname="l00015"></a><spanclass="lineno"> 15</span> </div><divclass="line"><aname="l00016"></a><spanclass="lineno"> 16</span> <spanclass="comment">// Generates a 16 byte CTR counter block. The CTR counter block format is a</span></div><divclass="line"><aname="l00017"></a><spanclass="lineno"> 17</span> <spanclass="comment">// CTR IV appended with a CTR block counter. |iv| is an 8 byte CTR IV.</span></div><divclass="line"><aname="l00018"></a><spanclass="lineno"> 18</span> <spanclass="comment">// |iv_size| is the size of |iv| in btyes. Returns a string of</span></div><divclass="line"><aname="l00019"></a><spanclass="lineno"> 19</span> <spanclass="comment">// kDecryptionKeySize bytes.</span></div><divclass="line"><aname="l00020"></a><spanclass="lineno"> 20</span> std::vector<uint8_t> GenerateWebMCounterBlock(<spanclass="keyword">const</span> uint8_t* iv, <spanclass="keywordtype">int</span> iv_size) {</div><divclass="line"><aname="l00021"></a><spanclass="lineno"> 21</span>  std::vector<uint8_t> counter_block(iv, iv + iv_size);</div><divclass="line"><aname="l00022"></a><spanclass="lineno"> 22</span>  counter_block.insert(counter_block.end(),</div><divclass="line"><aname="l00023"></a><spanclass="lineno"> 23</span> <aclass="code"href="../../de/d49/classshaka_1_1media_1_1DecryptConfig.html#afa140203b87d3e46d5fd94b231734f53">DecryptConfig::kDecryptionKeySize</a> - iv_size, 0);</div><divclass="line"><aname="l00024"></a><spanclass="lineno"> 24</span> <spanclass="keywordflow">return</span> counter_block;</div><divclass="line"><aname="l00025"></a><spanclass="lineno"> 25</span> }</div><divclass="line"><aname="l00026"></a><spanclass="lineno"> 26</span> </div><divclass="line"><aname="l00027"></a><spanclass="lineno"> 27</span> } <spanclass="comment">// namespace anonymous</span></div><divclas