JavaCard OS

Posted: **Mon Sep 18, 2017 12:36 am**

Hi all,
I have tested with PKI applet from github (https://github.com/JavaCardOS/Java-Card-PKI-Applet), I run samcode to get signature, then i convert signcert.der to create signature with java code (data inputs are one)

But i got result different with PKI applet

Here is my code in java code

Code: Select all

Signature sig = Signature.getInstance("Sha1WithRSA");
            
            sig.initSign(myPrivKey);
            sig.update(data);
            byte [] sign = sig.sign();
            System.out.println("Sign Data Done! \n");

Posted: **Tue Oct 10, 2017 2:11 am**

Signature sig = Signature.getInstance("Sha1WithRSA"); where alg name 'shawithRSA" is ambitious, i 've gone through the java API spec. 'shawithRSA" only indicates that PKCS#1 is used, however, PKCS#1 is comprised of Padding (PSS, Vi5 and OAEP), cipher primitives, but they are described in details in javacard APIs .

So, you modify your applet to try these constants: Signature.ALG_RSA_SHA_PKCS1, Signature.ALG_RSA_SHA_PKCS1_PSS
until you get the same result as your java code.

JavaCard OS

Result signature between signature from Applet and Java code

Result signature between signature from Applet and Java code

Re: Result signature between signature from Applet and Java code