General Information

The Java Card IsoApplet (e.g. for use with OpenSC). The Applet is capable of saving a PKCS#15 file structure and performing PKI related operations using the private key, such as signing or decrypting. Private keys can be generated directly on the smart card or imported from the host computer. The import of private keys is disabled in the default security configuration. The applet targets modern smartcards with Java Card 3.0.4 or above.

IsoApplet Version and Smartcard requirements

IsoApplet is maintained in two different versions: one for newer smartcards and a legacy version for older smartcards. If your smartcard supports the newer version of IsoApplet, you should prefer it. For both versions, the support of the "requestObjectDeletion()"-mechanism of the Java Card API is recommended to be able to properly delete files. Also, the javacardx.crypto.Cipher-package needs to be supported by your smart card. This is very common among Java Card smartcards.

New version of IsoApplet (v1)

This version is found on the main branch. It targets smartcards with Java Card version >= 3.0.4. This version requires extended APDUs the be used and supported by your reader and smartcard (javacardx.apdu.ExtendedLength). If supported by your smart card, the newer version of IsoApplet supports the following additional features:

RSA keys of 4096 bit length
RSA PSS signatures
ECDSA with off-card hashing, which makes ECC actually usable in practice

Legacy Version of IsoApplet (v0)

The legacy version is found on the main-javacard-v2.2.2 branch branch. It targets smartcards with Java Card version >= 2.2.2. The ECDSA implementation with Java Card version 2.2.2 is hardly usable in practice because it requires on-card hash generation. If your smartcard implements javacardx.apdu.ExtendedLength and IsoApplet is configured with DEF_EXT_APDU in IsoApplet.java, you can use extended APDUs.

Build process

This project uses ant-javacard to build cap-files. After cloning the IsoApplet repository, all you have to do is:

Perform git submodule init && git submodule update to retrieve the Java Card SDKs, in case you did not git clone --recursive to clone this repository.
Install Apache ant, openjdk-17-jdk-headless
Invoke ant to produce the cap file. If you have build errors on an existing repository, try deleting the ant-javacard.jar file so that the newest version is downloaded.

Installation

Install the CAP-file (IsoApplet.cap) to your Java Card smart card (e.g. with GlobalPlatformPro).

Have a look at the wiki for more information: https://github.com/philipWendland/IsoApplet/wiki