I have seperate classes which encrypt and decrypt input stream which is XML
contents.
I am testing decryption using XmlCipher.
Encryption worked OK. However, in the decryptionOnly, I am getting the
encrypted xml contents as an input and trying to convert its contents back to
the original XML input. I am getting the error below
java.lang.ArrayIndexOutOfBoundsException: -1 < 0
at java.util.Vector.elementAt(Vector.java:437)
at org.apache.xerces.dom.DeepNodeListImpl.item(Unknown Source)
at org.apache.xml.security.encryption.XMLCipher$Factory.newEncryptedData
(XMLCipher.java:2182)
at org.apache.xml.security.encryption.XMLCipher.decryptToByteArray
(XMLCipher.java:1367)
at org.apache.xml.security.encryption.XMLCipher.decryptElement
(XMLCipher.java:1299)
at org.apache.xml.security.encryption.XMLCipher.doFinal
(XMLCipher.java:748)
at XmlEncryptionTester.testDecryptOnly(XmlEncryptionTester.java:659)
---------------------------------------------------
My encrypted xml contents
<?xml version="1.0" encoding="UTF-8"?>
<xenc:EncryptedData Type="http://www.w3.org/2001/04/xmlenc#Element";
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#";>
<xenc:EncryptionMethod
Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc";
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#"/>
<xenc:CipherData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#";>
<xenc:CipherValue
xmlns:xenc="http://www.w3.org/2001/04/xmlenc#";>ECG7APZegNRhwInDUboc3Ret/T/wcGTaN
AillgDt8pyD8VLZSDntd+7u2jNkrjsT</xenc:CipherValue>
</xenc:CipherData>
</xenc:EncryptedData>
----------------------------------------------------
Here is my codes.
If I used the document which parse a file when Document is created, the
Decryption works OK. When documentbyParsingInputStream is called to get the
Document in testDecryptionOnly method, the prefix value of the ee element
ee = (Element) ed.getElementsByTagName("xenc:EncryptedData").item(0); is null.
private Document documentbyParsingInputStream(String inputFile) {
Document d = null;
try {
File f = new File(inputFile);
FileInputStream input = new FileInputStream(f);
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
dbf.setValidating(true);
dbf.setNamespaceAware(true);
d= db.parse(input);
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}
return (d);
}
private Document documentbyParsingInputStream(String inputFile) {
Document d = null;
try {
File f = new File(inputFile);
FileInputStream input = new FileInputStream(f);
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
dbf.setValidating(true);
dbf.setNamespaceAware(true);
d= db.parse(input);
} catch (Exception e) {
e.printStackTrace();
System.exit(-1);
}
return (d);
}
public void testDecryptOnly() throws Exception{
// if I call document method instread
// the documentbyParsingInputStream method , the deryption works fine.
Document ed = document("encrypted_TrippleDes.xml"); // source
// If documentbyParsingInputStream is called, then getting the
// exception above
//Document ed = documentbyParsingInputStream("e_TrippleDes.xml");// source
Document dd = null; // target
Element e = ed.getDocumentElement();
Element ee = null;
try {
// prepare for encryption
byte[] passPhrase = "24 Bytes per DESede key!".getBytes();
DESedeKeySpec keySpec = new DESedeKeySpec(passPhrase);
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DESede");
SecretKey key = keyFactory.generateSecret(keySpec);
//decrypt
cipher = XMLCipher.getInstance(XMLCipher.TRIPLEDES);
cipher.init(XMLCipher.DECRYPT_MODE, key);
ee = (Element) ed.getElementsByTagName("xenc:EncryptedData").item(0);
System.out.println(" ee.getPrefix() :"+ee.getPrefix());
// ee.getPrefix() is xenc when document is called.
// ee.getPrefix() is null when documentbyParsingInputStream is called.
dd = cipher.doFinal(ed, ee);
target = toString(dd);
} catch (Exception ex) {
ex.printStackTrace();
}
Assert.assertEquals( toString(document().getDocumentElement()), target);
}
I need to use an input as a stream when Document is created, I can't work out
why prefix is null if the inputStream is passed to the parse method when
creating the Document object. contents of the ed is same regardless of a method
I call. What am I doing wrong ? Any ideas will be appreciated
Thanks
hyejung
