There are a lot of subtleties to encryption/decryption having to do
with block size, pre-priming the buffers, and padding at the end.
It's more than just getting the algorithm and key right.
On Sep 24, 4:44 am, "draf...@gmail.com" <draf...@gmail.com> wrote:
> 0 down vote favorite
>
> I am trying to to download and decrypt an encrypted XML file.
>
> I have implemented the download part and have tested with an
> unencrypted file and it works fine.
>
> However I now need to be able to download an XML file that has been
> encrypted using AES and the key "XXXX"
>
> So I am only concerned with decryption as the encryption on the XML
> file is already done.
>
> Here is my code so far:
>
> public NodeList getXMLDoc(){
> URL url;
> NodeList nl = null;
>
> try{
> String xmlFeed = context.getString(R.string.xml_feed);
> try {
> url = new URL(xmlFeed);
> URLConnection urlConnection;
> urlConnection = url.openConnection();
> HttpURLConnection httpConnection = (HttpURLConnection)
> urlConnection;
> int responseCode = httpConnection.getResponseCode();
>
> if(responseCode == HttpURLConnection.HTTP_OK){
>
> String bytes = toHex("XXXX");
> SecretKeySpec skeySpec = new
> SecretKeySpec(toByte(bytes), "AES");
> try {
> c.init(Cipher.DECRYPT_MODE, skeySpec);
> //c.doFinal();
> } catch (InvalidKeyException e) {
> e.printStackTrace();
> }
> InputStream in = httpConnection.getInputStream();
> CipherInputStream cis = new CipherInputStream(in,
> c);
> DocumentBuilderFactory dbf;
> dbf = DocumentBuilderFactory.newInstance();
> DocumentBuilder db = dbf.newDocumentBuilder();
>
> Document dom = db.parse(cis);
>
> Element docEle = dom.getDocumentElement();
>
> nl = docEle.getElementsByTagName(TAG_CHAR);
>
> }
> }
> catch (MalformedURLException e) {
>
> e.printStackTrace();
> }
> catch (IOException e) {
>
> e.printStackTrace();
> } catch (ParserConfigurationException e) {
>
> e.printStackTrace();
> } catch (SAXException e) {
>
> e.printStackTrace();
> }
> }
> finally{
>
> }
> return nl;
> }
>
> At the minute I am trying to decrypt the whole file using
> CipherInputStream is this the correct approach?
>
> My code above gives me the following exception:
>
> WARN/System.err(5274): java.io.IOException: last block incomplete in
> decryption
>
> Is this a setup error or what might be causing this error?
>
> Are there any tutorials on how to decrypt an XML file in Android/Java?
>
> Am I going in the right direction as to how to decrypt the file or is
> my code completely wrong?
--
You received this message because you are subscribed to the Google
Groups "Android Developers" group.
To post to this group, send email to android-developers@googlegroups.com
To unsubscribe from this group, send email to
android-developers+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/android-developers?hl=en
