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AW: [iaik-jce] Applet Edition JCE: DEREncoder exception



Hello,
 
PKCS#7 is not suitable for DSA because the hash value (together with the digest algorithm identifier) is packed into a DigestInfo sequence (to work against attacks due to digest algorithm compromise)  which subsequently is encoded and encrypted with the signer´s private key. DSA, however, needs the 160 bit SHA hash (not wrapped into a DigestInfo). PKCS#7 successor CMS (we work on it) does not do the DigestInfo wrapping and so also may be used for DSA. (when using CMS with RSA, the DigestInfo wrapping is performed "inside" the RSA signature process and no more longer "outside" for any algorithm used).
 
Regards,
Dieter Bratko
-----Ursprüngliche Nachricht-----
Von: iaik-jce-owner@iaik.tu-graz.ac.at [mailto:iaik-jce-owner@iaik.tu-graz.ac.at]Im Auftrag von Kevin Crosbie
Gesendet: Sonntag, 10. September 2000 23:16
An: Greg Stark
Cc: iaik-jce@iaik.at
Betreff: RE: [iaik-jce] Applet Edition JCE: DEREncoder exception

Hi Greg,
 
That's right, I did use that constructor:
 
     SignerInfo signerInfo = new SignerInfo(new IssuerAndSerialNumber(X509cert), AlgorithmID.sha, privateK);
 
So is the problem to do with my using a DSA certificate?   I tried setting the AlgorithmID to dsaWithSha(there are three different algorithmID's for this listed)
 
Is there a solution for this using the DSA cert, or do I need to use an RSA cert, or is there a solution at all?  It seems like a bit of a catch22 if there is no solution, the Applet Edition JCE only allows you to create a DSA certificate, yet doesn't support signing with this cert...
 
Any ideas?
 
Cheers,
 
Kevin
-----Original Message-----
From: Greg Stark [mailto:gstark@ethentica.com]
Sent: Saturday, September 09, 2000 5:10 PM
To: Kevin Crosbie
Subject: Re: [iaik-jce] Applet Edition JCE: DEREncoder exception

The signing algorithm is also described as the "digest encryption algorithm" in the JCE documentation and various standards such as PKCS#7 and, unfortunately, JCE2.6 claims to only support RSA for this. The algorithm is set in the SignerInfo structure of the SignedData object, see the iaik.pkcs.pkcs7.SignerInfo class. I am curious which constructor you used for this class. I'll bet it was the
 
public SignerInfo(IssuerAndSerialNumber issuerAndSerialNumber,  AlgorithmID digestAlgorithm,   PrivateKey privateKey)
 
constructor. I think these constructors should throw an UnsupportedAlgorithm exception in cases like yours, but they don't.
 
 
Greg Stark, gstark@ethentica.com
Chief Security Architect
Ethentica, Inc.
www.ethentica.com
 
 
----- Original Message -----
From: Kevin Crosbie
 
To: iaik-jce@iaik.at
Sent: Friday, September 08, 2000 10:16 PM
Subject: [iaik-jce] Applet Edition JCE: DEREncoder exception

Hi,
 
I have written a signed applet which creates a DSA certificate, stores it on disk, and signs data with it.
 
When I call the SignedData.getEncoded(), I get the following exception:
 
java.lang.RuntimeException: Error from EncodeListener: Unable to encrypt digest: Cipher::getInstance(String) - no Cipher could be found for this algorithm - RSA/ECB/PKCS1Padding - amongst any of the providers.
 at iaik/asn1/DerCoder.encode
 at iaik/asn1/DerCoder.encodeTo
 at iaik/asn1/ConstructedType.encode
 at iaik/asn1/ASN1Object.encodeObject
 at iaik/asn1/DerCoder.encodeTo
 at iaik/asn1/DerCoder.encodeTo
 at iaik/pkcs/pkcs7/SignedData.getEncoded
 at IaikApplet.engineSignData
 at IaikApplet.signData
 at IaikApplet$HandleButton.actionPerformed
 at java/awt/Button.processActionEvent
 at java/awt/Button.processEvent
 at java/awt/Component.dispatchEventImpl
 at java/awt/Component.dispatchEvent
 at java/awt/EventDispatchThread.run
 
 
I don't know where you can set the encryption type, I figured if the cert was DSA it should sign using DSA.   Is this exception there because this is the Applet edition, as I know that it does not implement everything, and I know it does not implement RSA(does it??)
 
Can anyone tell me a workaround?
 
Thanks,
 
Kevin
 

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