关于图片解码

[laomms]

下载图片附件返回这种格式的该如何用aeskey和cdnthumburl解码？

<?xml version="1.0"?>
<msg>
  <img aeskey="d7621106ee9741a4144afbe06404068c" encryver="1" cdnthumbaeskey="d7621106ee9741a4144afbe06404068c" cdnthumburl="3057020100044b30490201000204c1473b4002032f56c30204e5540d70020466b42776042430383532626330392d366239642d343636312d386135322d353936376462353066316232020405250a020201000405004c53db00" cdnthumblength="3915" cdnthumbheight="68" cdnthumbwidth="120" cdnmidheight="0" cdnmidwidth="0" cdnhdheight="0" cdnhdwidth="0" cdnmidimgurl="3057020100044b30490201000204c1473b4002032f56c30204e5540d70020466b42776042430383532626330392d366239642d343636312d386135322d353936376462353066316232020405250a020201000405004c53db00" length="49905" md5="3ca7d6b7478792dee92e1bb1b32fcde1" originsourcemd5="5f486ddff7f9aa38103862b89f1e8be3" ></img>
  <platform_signature></platform_signature>
  <imgdatahash></imgdatahash>
  <ImgSourceInfo>
    <ImgSourceUrl>
      <BizType>0</BizType>
    </ImgSourceInfo>
  </msg>