Java Security

Hello

I�m trying to encrypt and decrypt a PKCS7 XML message. I successfully encrypt it , but when I run the decrypt method with the encrypted result, I receive a java.lang.NegativeArraySizeException at org.bouncycastle.asn1.DERInputStream.readObject(DERInputStream.java:266) when I try to read the DERObject with the readObject() method of the DERInputStream.

I�m doing the right thing? Is my decode method ok?

Thanks a lot

Fabi�n


public String encode(String certificateFile, String xmlFile )throws Exception{

Security.addProvider(new BouncyCastleProvider());

FileInputStream fis = new FileInputStream(certificateFile);
CertificateFactory cf = CertificateFactory.getInstance("X509", "BC");
X509Certificate cert = (X509Certificate) cf.generateCertificate(fis);
fis.close();

File f = new File(xmlFile) ;
int sizecontent = ((int) f.length());
byte[] contentbytes = new byte[sizecontent];

FileInputStream freader = new FileInputStream(f);
freader.close();

String algorithm = CMSEnvelopedDataGenerator.DES_EDE3_CBC;
CMSEnvelopedDataGenerator fact = new CMSEnvelopedDataGenerator();
fact.addKeyTransRecipient(cert);
CMSProcessableByteArray content = new CMSProcessableByteArray(contentbytes);

CMSEnvelopedData envdata = fact.generate(content, algorithm, "BC");
byte[] enveloped = envdata.getEncoded();

enveloped = Base64.encode(enveloped);

return new String(enveloped);
}



public String decode(String dataEnc)throws Exception{

Security.addProvider(new BouncyCastleProvider());

byte[] data = Base64.decode(dataEnc);

DERInputStream din = new DERInputStream(new ByteArrayInputStream(data));
DERObject pkcs;
pkcs = din.readObject();
if (!(pkcs instanceof DERConstructedSequence))
throw new SecurityException("Not a valid PKCS#7 object - not a sequence");
ContentInfo content = ContentInfo.getInstance(pkcs);
if(!content.getContentType().equals(PKCSObjectIdentifiers.signedData))
throw new SecurityException("Not a valid PKCS#7 signed-data object - wrong header " + content.getContentType().getId());
SignedData sdata = SignedData.getInstance(content.getContent());
content = sdata.getEncapContentInfo();
if(!content.getContentType().equals(PKCSObjectIdentifiers.data))
throw new SecurityException("Not a valid PKCS#7 data object - not an attached signature");
byte[] dataresp = ((ASN1OctetString)content.getContent()).getOctets();

return new String (dataresp);
}