Network Security Services for Java (JSS) is a Java interface to NSS. JSS supports most of the security standards and encryption technologies supported by NSS. JSS also provides a pure Java interface for ASN.1 types and BER/DER encoding.

JSS offers a implementation of Java SSL sockets that uses NSS's SSL/TLS implementation rather than Sun's JSSE implementation. You might want to use JSS's own SSL classes if you want to use some of the capabilities found in NSS's SSL/TLS library but not found in JSSE.

NSS is the cryptographic module where all cryptographic operations are performed. JSS essentially provides a Java JNI bridge to NSS C shared libraries. When NSS is put in FIPS mode, JSS ensures FIPS compliance by ensuring that all cryptographic operations are performed by the NSS cryptographic module.

JSS offers a JCE provider, "Mozilla-JSS" JCA Provider notes.

JSS, jss4.jar, is still built with JDK 1.4.2. While JDK 1.4.2 is EOL'd and all new product development should be using the latest JavaSE, legacy business products that must use JDK 1.4 or 1.5 can continue to add NSS/JSS security fixes/enhancements.

JSS is used by Red Hat and Sun products that do crypto in Java. JSS is available under the Mozilla Public License, the GNU General Public License, and the GNU Lesser General Public License. JSS requires NSPR and NSS.

Java provides a JCE provider called SunPKCS11 (see Java PKCS#11 Reference Guide.) SunPKCS11 can be configured to use the NSS module as the crytographic provider. If you are planning to just use JSS JCE provider as a bridge to NSS's FIPS validated PKCS#11 module, then the SunPKCS11 JCE provider may do all that you need. Note that Java 1.5 claimed no FIPS compliance, and Java 1.6 or higher needs to be used. A current limitation to the configured SunPKCS11-NSS bridge configuration is if you add a PKCS#11 module to the NSS database such as for a smartcard, you won't be able to access that smartcard through the SunPKCS11-NSS bridge. If you use JSS, you can easily get lists of modules and tokens that are configured in the NSS DB and freely access all of it.