Java Security

Hello!

I have an signed file xxx.p7m

When I try to create a CMSSignedData object, I get the following error:
org.bouncycastle.cms.CMSException: Malformed content.
at org.bouncycastle.cms.CMSUtils.readContentInfo(Unknown Source)
at org.bouncycastle.cms.CMSUtils.readContentInfo(Unknown Source)
at org.bouncycastle.cms.CMSSignedData.<init>(Unknown Source)
at ro.sdc.main.BouncyCastleVerify.main(BouncyCastleVerify.java:42)
Caused by: java.lang.IllegalArgumentException: unknown object in factory: org.bouncycastle.asn1.DERApplicationSpecific
at org.bouncycastle.asn1.cms.ContentInfo.getInstance(Unknown Source)
... 4 more


what i want to do i sto extract the content from the signed file

here is my code to accomplish this:

try {
//load signed file
File f = new File(INPUT_FILENAME);
byte[] buffer = new byte[(int)f.length()];
DataInputStream in = new DataInputStream(new FileInputStream(f));
in.readFully(buffer);
in.close();


CMSSignedData signature = new CMSSignedData(buffer);
SignerInformation signer = (SignerInformation)signature
.getSignerInfos().getSigners().iterator().next();
CertStore cs = signature
.getCertificatesAndCRLs("Collection", "BC");
Iterator iter = cs.getCertificates(signer.getSID()).iterator();
X509Certificate certificate = (X509Certificate) iter.next();
CMSProcessable sc = signature.getSignedContent();
byte[] data = (byte[]) sc.getContent();

//verify signature
System.out.println(signer.verify(certificate, "BC"));

//extract data from signed file
FileOutputStream envfos = new FileOutputStream(OUTPUT_FILENAME);
envfos.write(data);
envfos.close();
} catch (Exception e) {
e.printStackTrace();
return ;
}


any ideas why this error occurs?

thank you!