267 lines
31 KiB
HTML
267 lines
31 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
|
|
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
|
|
<meta name="generator" content="Doxygen 1.8.6"/>
|
|
<title>DASH Media Packaging SDK: media/base/aes_decryptor.cc Source File</title>
|
|
<link href="../../tabs.css" rel="stylesheet" type="text/css"/>
|
|
<script type="text/javascript" src="../../jquery.js"></script>
|
|
<script type="text/javascript" src="../../dynsections.js"></script>
|
|
<link href="../../search/search.css" rel="stylesheet" type="text/css"/>
|
|
<script type="text/javascript" src="../../search/search.js"></script>
|
|
<script type="text/javascript">
|
|
$(document).ready(function() { searchBox.OnSelectItem(0); });
|
|
</script>
|
|
<link href="../../doxygen.css" rel="stylesheet" type="text/css" />
|
|
</head>
|
|
<body>
|
|
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
|
|
<div id="titlearea">
|
|
<table cellspacing="0" cellpadding="0">
|
|
<tbody>
|
|
<tr style="height: 56px;">
|
|
<td style="padding-left: 0.5em;">
|
|
<div id="projectname">DASH Media Packaging SDK
|
|
</div>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
<!-- end header part -->
|
|
<!-- Generated by Doxygen 1.8.6 -->
|
|
<script type="text/javascript">
|
|
var searchBox = new SearchBox("searchBox", "../../search",false,'Search');
|
|
</script>
|
|
<div id="navrow1" class="tabs">
|
|
<ul class="tablist">
|
|
<li><a href="../../index.html"><span>Main Page</span></a></li>
|
|
<li><a href="../../namespaces.html"><span>Namespaces</span></a></li>
|
|
<li><a href="../../annotated.html"><span>Classes</span></a></li>
|
|
<li class="current"><a href="../../files.html"><span>Files</span></a></li>
|
|
<li>
|
|
<div id="MSearchBox" class="MSearchBoxInactive">
|
|
<span class="left">
|
|
<img id="MSearchSelect" src="../../search/mag_sel.png"
|
|
onmouseover="return searchBox.OnSearchSelectShow()"
|
|
onmouseout="return searchBox.OnSearchSelectHide()"
|
|
alt=""/>
|
|
<input type="text" id="MSearchField" value="Search" accesskey="S"
|
|
onfocus="searchBox.OnSearchFieldFocus(true)"
|
|
onblur="searchBox.OnSearchFieldFocus(false)"
|
|
onkeyup="searchBox.OnSearchFieldChange(event)"/>
|
|
</span><span class="right">
|
|
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="../../search/close.png" alt=""/></a>
|
|
</span>
|
|
</div>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div id="navrow2" class="tabs2">
|
|
<ul class="tablist">
|
|
<li><a href="../../files.html"><span>File List</span></a></li>
|
|
</ul>
|
|
</div>
|
|
<!-- window showing the filter options -->
|
|
<div id="MSearchSelectWindow"
|
|
onmouseover="return searchBox.OnSearchSelectShow()"
|
|
onmouseout="return searchBox.OnSearchSelectHide()"
|
|
onkeydown="return searchBox.OnSearchSelectKey(event)">
|
|
<a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark"> </span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark"> </span>Classes</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark"> </span>Namespaces</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark"> </span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark"> </span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark"> </span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark"> </span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark"> </span>Enumerator</a></div>
|
|
|
|
<!-- iframe showing the search results (closed by default) -->
|
|
<div id="MSearchResultsWindow">
|
|
<iframe src="javascript:void(0)" frameborder="0"
|
|
name="MSearchResults" id="MSearchResults">
|
|
</iframe>
|
|
</div>
|
|
|
|
<div id="nav-path" class="navpath">
|
|
<ul>
|
|
<li class="navelem"><a class="el" href="../../dir_39dc0668bd5a501998f94e8b4e546c71.html">media</a></li><li class="navelem"><a class="el" href="../../dir_c6ada2450b25ab5438a4dba6c9b890af.html">base</a></li> </ul>
|
|
</div>
|
|
</div><!-- top -->
|
|
<div class="header">
|
|
<div class="headertitle">
|
|
<div class="title">aes_decryptor.cc</div> </div>
|
|
</div><!--header-->
|
|
<div class="contents">
|
|
<div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">// Copyright 2016 Google Inc. All rights reserved.</span></div>
|
|
<div class="line"><a name="l00002"></a><span class="lineno"> 2</span> <span class="comment">//</span></div>
|
|
<div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment">// Use of this source code is governed by a BSD-style</span></div>
|
|
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment">// license that can be found in the LICENSE file or at</span></div>
|
|
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment">// https://developers.google.com/open-source/licenses/bsd</span></div>
|
|
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span> </div>
|
|
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="preprocessor">#include "packager/media/base/aes_decryptor.h"</span></div>
|
|
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span> </div>
|
|
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="preprocessor">#include <openssl/aes.h></span></div>
|
|
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="preprocessor">#include <algorithm></span></div>
|
|
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="preprocessor">#include "packager/base/logging.h"</span></div>
|
|
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span> </div>
|
|
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="keyword">namespace </span>{</div>
|
|
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span> </div>
|
|
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="comment">// AES defines three key sizes: 128, 192 and 256 bits.</span></div>
|
|
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="keywordtype">bool</span> IsKeySizeValidForAes(<span class="keywordtype">size_t</span> key_size) {</div>
|
|
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span>  <span class="keywordflow">return</span> key_size == 16 || key_size == 24 || key_size == 32;</div>
|
|
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span> }</div>
|
|
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span> </div>
|
|
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span> } <span class="comment">// namespace</span></div>
|
|
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span> </div>
|
|
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span> <span class="keyword">namespace </span>shaka {</div>
|
|
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="keyword">namespace </span>media {</div>
|
|
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span> </div>
|
|
<div class="line"><a name="l00025"></a><span class="lineno"><a class="line" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a855ab9fa2f350879a7716ec90033f825"> 25</a></span> <a class="code" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a855ab9fa2f350879a7716ec90033f825">AesCbcDecryptor::AesCbcDecryptor</a>(CbcPaddingScheme padding_scheme)</div>
|
|
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span>  : <a class="code" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html">AesCbcDecryptor</a>(padding_scheme, kDontUseConstantIv) {}</div>
|
|
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span> </div>
|
|
<div class="line"><a name="l00028"></a><span class="lineno"><a class="line" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a350d11c34c42ee4d4e62cdd7aebc5fbb"> 28</a></span> <a class="code" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a855ab9fa2f350879a7716ec90033f825">AesCbcDecryptor::AesCbcDecryptor</a>(CbcPaddingScheme padding_scheme,</div>
|
|
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span>  ConstantIvFlag constant_iv_flag)</div>
|
|
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>  : <a class="code" href="../../df/d87/classshaka_1_1media_1_1AesCryptor.html">AesCryptor</a>(constant_iv_flag), padding_scheme_(padding_scheme) {</div>
|
|
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span>  <span class="keywordflow">if</span> (padding_scheme_ != kNoPadding) {</div>
|
|
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span>  CHECK_EQ(constant_iv_flag, kUseConstantIv)</div>
|
|
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span>  << <span class="stringliteral">"non-constant iv (cipher block chain across calls) only makes sense "</span></div>
|
|
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span>  <span class="stringliteral">"if the padding_scheme is kNoPadding."</span>;</div>
|
|
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span>  }</div>
|
|
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span> }</div>
|
|
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span> </div>
|
|
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span> AesCbcDecryptor::~AesCbcDecryptor() {}</div>
|
|
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span> </div>
|
|
<div class="line"><a name="l00040"></a><span class="lineno"><a class="line" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a71ff0b9654de96f9990b29c35fa9b7bf"> 40</a></span> <span class="keywordtype">bool</span> <a class="code" href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a71ff0b9654de96f9990b29c35fa9b7bf">AesCbcDecryptor::InitializeWithIv</a>(<span class="keyword">const</span> std::vector<uint8_t>& key,</div>
|
|
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span>  <span class="keyword">const</span> std::vector<uint8_t>& iv) {</div>
|
|
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span>  <span class="keywordflow">if</span> (!IsKeySizeValidForAes(key.size())) {</div>
|
|
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span>  LOG(ERROR) << <span class="stringliteral">"Invalid AES key size: "</span> << key.size();</div>
|
|
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span>  }</div>
|
|
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span> </div>
|
|
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span>  CHECK_EQ(AES_set_decrypt_key(key.data(), key.size() * 8, mutable_aes_key()),</div>
|
|
<div class="line"><a name="l00048"></a><span class="lineno"> 48</span>  0);</div>
|
|
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span>  <span class="keywordflow">return</span> <a class="code" href="../../df/d87/classshaka_1_1media_1_1AesCryptor.html#a4875146da4761bb757d6b00132ae6fea">SetIv</a>(iv);</div>
|
|
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span> }</div>
|
|
<div class="line"><a name="l00051"></a><span class="lineno"> 51</span> </div>
|
|
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span> <span class="keywordtype">bool</span> AesCbcDecryptor::CryptInternal(<span class="keyword">const</span> uint8_t* ciphertext,</div>
|
|
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span>  <span class="keywordtype">size_t</span> ciphertext_size,</div>
|
|
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  uint8_t* plaintext,</div>
|
|
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span>  <span class="keywordtype">size_t</span>* plaintext_size) {</div>
|
|
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span>  DCHECK(plaintext_size);</div>
|
|
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span>  DCHECK(aes_key());</div>
|
|
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="comment">// Plaintext size is the same as ciphertext size except for pkcs5 padding.</span></div>
|
|
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  <span class="comment">// Will update later if using pkcs5 padding. For pkcs5 padding, we still</span></div>
|
|
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span>  <span class="comment">// need at least |ciphertext_size| bytes for intermediate operation.</span></div>
|
|
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  <span class="keywordflow">if</span> (*plaintext_size < ciphertext_size) {</div>
|
|
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  LOG(ERROR) << <span class="stringliteral">"Expecting output size of at least "</span> << ciphertext_size</div>
|
|
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span>  << <span class="stringliteral">" bytes."</span>;</div>
|
|
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00065"></a><span class="lineno"> 65</span>  }</div>
|
|
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span>  *plaintext_size = ciphertext_size;</div>
|
|
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span> </div>
|
|
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  <span class="keywordflow">if</span> (ciphertext_size == 0) {</div>
|
|
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span>  <span class="keywordflow">if</span> (padding_scheme_ == kPkcs5Padding) {</div>
|
|
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span>  LOG(ERROR) << <span class="stringliteral">"Expected ciphertext to be at least "</span> << AES_BLOCK_SIZE</div>
|
|
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span>  << <span class="stringliteral">" bytes with Pkcs5 padding."</span>;</div>
|
|
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span>  }</div>
|
|
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00075"></a><span class="lineno"> 75</span>  }</div>
|
|
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  DCHECK(plaintext);</div>
|
|
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span> </div>
|
|
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> residual_block_size = ciphertext_size % AES_BLOCK_SIZE;</div>
|
|
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  <span class="keyword">const</span> <span class="keywordtype">size_t</span> cbc_size = ciphertext_size - residual_block_size;</div>
|
|
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>  <span class="keywordflow">if</span> (residual_block_size == 0) {</div>
|
|
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  AES_cbc_encrypt(ciphertext, plaintext, ciphertext_size, aes_key(),</div>
|
|
<div class="line"><a name="l00082"></a><span class="lineno"> 82</span>  internal_iv_.data(), AES_DECRYPT);</div>
|
|
<div class="line"><a name="l00083"></a><span class="lineno"> 83</span>  <span class="keywordflow">if</span> (padding_scheme_ != kPkcs5Padding)</div>
|
|
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span> </div>
|
|
<div class="line"><a name="l00086"></a><span class="lineno"> 86</span>  <span class="comment">// Strip off PKCS5 padding bytes.</span></div>
|
|
<div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  <span class="keyword">const</span> uint8_t num_padding_bytes = plaintext[ciphertext_size - 1];</div>
|
|
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span>  <span class="keywordflow">if</span> (num_padding_bytes > AES_BLOCK_SIZE) {</div>
|
|
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  LOG(ERROR) << <span class="stringliteral">"Padding length is too large : "</span></div>
|
|
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  << <span class="keyword">static_cast<</span><span class="keywordtype">int</span><span class="keyword">></span>(num_padding_bytes);</div>
|
|
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span>  }</div>
|
|
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  *plaintext_size -= num_padding_bytes;</div>
|
|
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (padding_scheme_ == kNoPadding) {</div>
|
|
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span>  AES_cbc_encrypt(ciphertext, plaintext, cbc_size, aes_key(),</div>
|
|
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span>  internal_iv_.data(), AES_DECRYPT);</div>
|
|
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span> </div>
|
|
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span>  <span class="comment">// The residual block is not encrypted.</span></div>
|
|
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  memcpy(plaintext + cbc_size, ciphertext + cbc_size, residual_block_size);</div>
|
|
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  } <span class="keywordflow">else</span> <span class="keywordflow">if</span> (padding_scheme_ != kCtsPadding) {</div>
|
|
<div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  LOG(ERROR) << <span class="stringliteral">"Expecting cipher text size to be multiple of "</span></div>
|
|
<div class="line"><a name="l00104"></a><span class="lineno"> 104</span>  << AES_BLOCK_SIZE << <span class="stringliteral">", got "</span> << ciphertext_size;</div>
|
|
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  <span class="keywordflow">return</span> <span class="keyword">false</span>;</div>
|
|
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  }</div>
|
|
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span> </div>
|
|
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span>  DCHECK_EQ(padding_scheme_, kCtsPadding);</div>
|
|
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span>  <span class="keywordflow">if</span> (ciphertext_size < AES_BLOCK_SIZE) {</div>
|
|
<div class="line"><a name="l00110"></a><span class="lineno"> 110</span>  <span class="comment">// Don't have a full block, leave unencrypted.</span></div>
|
|
<div class="line"><a name="l00111"></a><span class="lineno"> 111</span>  memcpy(plaintext, ciphertext, ciphertext_size);</div>
|
|
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span>  }</div>
|
|
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span> </div>
|
|
<div class="line"><a name="l00115"></a><span class="lineno"> 115</span>  <span class="comment">// AES-CBC decrypt everything up to the next-to-last full block.</span></div>
|
|
<div class="line"><a name="l00116"></a><span class="lineno"> 116</span>  <span class="keywordflow">if</span> (cbc_size > AES_BLOCK_SIZE) {</div>
|
|
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span>  AES_cbc_encrypt(ciphertext, plaintext, cbc_size - AES_BLOCK_SIZE, aes_key(),</div>
|
|
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span>  internal_iv_.data(), AES_DECRYPT);</div>
|
|
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span>  }</div>
|
|
<div class="line"><a name="l00120"></a><span class="lineno"> 120</span> </div>
|
|
<div class="line"><a name="l00121"></a><span class="lineno"> 121</span>  <span class="keyword">const</span> uint8_t* next_to_last_ciphertext_block =</div>
|
|
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span>  ciphertext + ciphertext_size - residual_block_size - AES_BLOCK_SIZE;</div>
|
|
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span>  uint8_t* next_to_last_plaintext_block =</div>
|
|
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span>  plaintext + ciphertext_size - residual_block_size - AES_BLOCK_SIZE;</div>
|
|
<div class="line"><a name="l00125"></a><span class="lineno"> 125</span> </div>
|
|
<div class="line"><a name="l00126"></a><span class="lineno"> 126</span>  <span class="comment">// Determine what the last IV should be so that we can "skip ahead" in the</span></div>
|
|
<div class="line"><a name="l00127"></a><span class="lineno"> 127</span>  <span class="comment">// CBC decryption.</span></div>
|
|
<div class="line"><a name="l00128"></a><span class="lineno"> 128</span>  std::vector<uint8_t> last_iv(</div>
|
|
<div class="line"><a name="l00129"></a><span class="lineno"> 129</span>  ciphertext + ciphertext_size - residual_block_size,</div>
|
|
<div class="line"><a name="l00130"></a><span class="lineno"> 130</span>  ciphertext + ciphertext_size);</div>
|
|
<div class="line"><a name="l00131"></a><span class="lineno"> 131</span>  last_iv.resize(AES_BLOCK_SIZE, 0);</div>
|
|
<div class="line"><a name="l00132"></a><span class="lineno"> 132</span> </div>
|
|
<div class="line"><a name="l00133"></a><span class="lineno"> 133</span>  <span class="comment">// Decrypt the next-to-last block using the IV determined above. This decrypts</span></div>
|
|
<div class="line"><a name="l00134"></a><span class="lineno"> 134</span>  <span class="comment">// the residual block bits.</span></div>
|
|
<div class="line"><a name="l00135"></a><span class="lineno"> 135</span>  AES_cbc_encrypt(next_to_last_ciphertext_block, next_to_last_plaintext_block,</div>
|
|
<div class="line"><a name="l00136"></a><span class="lineno"> 136</span>  AES_BLOCK_SIZE, aes_key(), last_iv.data(), AES_DECRYPT);</div>
|
|
<div class="line"><a name="l00137"></a><span class="lineno"> 137</span> </div>
|
|
<div class="line"><a name="l00138"></a><span class="lineno"> 138</span>  <span class="comment">// Swap back the residual block bits and the next-to-last block.</span></div>
|
|
<div class="line"><a name="l00139"></a><span class="lineno"> 139</span>  <span class="keywordflow">if</span> (plaintext == ciphertext) {</div>
|
|
<div class="line"><a name="l00140"></a><span class="lineno"> 140</span>  std::swap_ranges(next_to_last_plaintext_block,</div>
|
|
<div class="line"><a name="l00141"></a><span class="lineno"> 141</span>  next_to_last_plaintext_block + residual_block_size,</div>
|
|
<div class="line"><a name="l00142"></a><span class="lineno"> 142</span>  next_to_last_plaintext_block + AES_BLOCK_SIZE);</div>
|
|
<div class="line"><a name="l00143"></a><span class="lineno"> 143</span>  } <span class="keywordflow">else</span> {</div>
|
|
<div class="line"><a name="l00144"></a><span class="lineno"> 144</span>  memcpy(next_to_last_plaintext_block + AES_BLOCK_SIZE,</div>
|
|
<div class="line"><a name="l00145"></a><span class="lineno"> 145</span>  next_to_last_plaintext_block, residual_block_size);</div>
|
|
<div class="line"><a name="l00146"></a><span class="lineno"> 146</span>  memcpy(next_to_last_plaintext_block,</div>
|
|
<div class="line"><a name="l00147"></a><span class="lineno"> 147</span>  next_to_last_ciphertext_block + AES_BLOCK_SIZE, residual_block_size);</div>
|
|
<div class="line"><a name="l00148"></a><span class="lineno"> 148</span>  }</div>
|
|
<div class="line"><a name="l00149"></a><span class="lineno"> 149</span> </div>
|
|
<div class="line"><a name="l00150"></a><span class="lineno"> 150</span>  <span class="comment">// Decrypt the next-to-last full block.</span></div>
|
|
<div class="line"><a name="l00151"></a><span class="lineno"> 151</span>  AES_cbc_encrypt(next_to_last_plaintext_block, next_to_last_plaintext_block,</div>
|
|
<div class="line"><a name="l00152"></a><span class="lineno"> 152</span>  AES_BLOCK_SIZE, aes_key(), internal_iv_.data(), AES_DECRYPT);</div>
|
|
<div class="line"><a name="l00153"></a><span class="lineno"> 153</span>  <span class="keywordflow">return</span> <span class="keyword">true</span>;</div>
|
|
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span> }</div>
|
|
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span> </div>
|
|
<div class="line"><a name="l00156"></a><span class="lineno"> 156</span> <span class="keywordtype">void</span> AesCbcDecryptor::SetIvInternal() {</div>
|
|
<div class="line"><a name="l00157"></a><span class="lineno"> 157</span>  internal_iv_ = <a class="code" href="../../df/d87/classshaka_1_1media_1_1AesCryptor.html#a96dde16f12a82a563c77f6d5522571f3">iv</a>();</div>
|
|
<div class="line"><a name="l00158"></a><span class="lineno"> 158</span>  internal_iv_.resize(AES_BLOCK_SIZE, 0);</div>
|
|
<div class="line"><a name="l00159"></a><span class="lineno"> 159</span> }</div>
|
|
<div class="line"><a name="l00160"></a><span class="lineno"> 160</span> </div>
|
|
<div class="line"><a name="l00161"></a><span class="lineno"> 161</span> } <span class="comment">// namespace media</span></div>
|
|
<div class="line"><a name="l00162"></a><span class="lineno"> 162</span> } <span class="comment">// namespace shaka</span></div>
|
|
<div class="ttc" id="classshaka_1_1media_1_1AesCryptor_html"><div class="ttname"><a href="../../df/d87/classshaka_1_1media_1_1AesCryptor.html">shaka::media::AesCryptor</a></div><div class="ttdef"><b>Definition:</b> <a href="../../d0/d42/aes__cryptor_8h_source.html#l00025">aes_cryptor.h:25</a></div></div>
|
|
<div class="ttc" id="classshaka_1_1media_1_1AesCbcDecryptor_html"><div class="ttname"><a href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html">shaka::media::AesCbcDecryptor</a></div><div class="ttdoc">Class which implements AES-CBC (Cipher block chaining) decryption. </div><div class="ttdef"><b>Definition:</b> <a href="../../d8/d4d/aes__decryptor_8h_source.html#l00025">aes_decryptor.h:25</a></div></div>
|
|
<div class="ttc" id="classshaka_1_1media_1_1AesCbcDecryptor_html_a855ab9fa2f350879a7716ec90033f825"><div class="ttname"><a href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a855ab9fa2f350879a7716ec90033f825">shaka::media::AesCbcDecryptor::AesCbcDecryptor</a></div><div class="ttdeci">AesCbcDecryptor(CbcPaddingScheme padding_scheme)</div><div class="ttdef"><b>Definition:</b> <a href="../../da/df4/aes__decryptor_8cc_source.html#l00025">aes_decryptor.cc:25</a></div></div>
|
|
<div class="ttc" id="classshaka_1_1media_1_1AesCryptor_html_a96dde16f12a82a563c77f6d5522571f3"><div class="ttname"><a href="../../df/d87/classshaka_1_1media_1_1AesCryptor.html#a96dde16f12a82a563c77f6d5522571f3">shaka::media::AesCryptor::iv</a></div><div class="ttdeci">const std::vector< uint8_t > & iv() const </div><div class="ttdef"><b>Definition:</b> <a href="../../d0/d42/aes__cryptor_8h_source.html#l00081">aes_cryptor.h:81</a></div></div>
|
|
<div class="ttc" id="classshaka_1_1media_1_1AesCbcDecryptor_html_a71ff0b9654de96f9990b29c35fa9b7bf"><div class="ttname"><a href="../../df/d2d/classshaka_1_1media_1_1AesCbcDecryptor.html#a71ff0b9654de96f9990b29c35fa9b7bf">shaka::media::AesCbcDecryptor::InitializeWithIv</a></div><div class="ttdeci">bool InitializeWithIv(const std::vector< uint8_t > &key, const std::vector< uint8_t > &iv) override</div><div class="ttdef"><b>Definition:</b> <a href="../../da/df4/aes__decryptor_8cc_source.html#l00040">aes_decryptor.cc:40</a></div></div>
|
|
<div class="ttc" id="classshaka_1_1media_1_1AesCryptor_html_a4875146da4761bb757d6b00132ae6fea"><div class="ttname"><a href="../../df/d87/classshaka_1_1media_1_1AesCryptor.html#a4875146da4761bb757d6b00132ae6fea">shaka::media::AesCryptor::SetIv</a></div><div class="ttdeci">bool SetIv(const std::vector< uint8_t > &iv)</div><div class="ttdef"><b>Definition:</b> <a href="../../d6/d55/aes__cryptor_8cc_source.html#l00067">aes_cryptor.cc:67</a></div></div>
|
|
</div><!-- fragment --></div><!-- contents -->
|
|
<!-- start footer part -->
|
|
<hr class="footer"/><address class="footer"><small>
|
|
Generated on Sat Feb 11 2017 01:23:51 for DASH Media Packaging SDK by  <a href="http://www.doxygen.org/index.html">
|
|
<img class="footer" src="../../doxygen.png" alt="doxygen"/>
|
|
</a> 1.8.6
|
|
</small></address>
|
|
</body>
|
|
</html>
|