Web Services Security: SOAP Message Security (WS-Security) is an international standard for interoperable Web Services Security that was collaboratively developed in OASIS by all the major providers of web services technology (including Sun Microsystems). WS-Security is a message security mechanism that uses XML Encryption and XML Digital Signature to secure web services messages sent over SOAP. The WS-Security specification defines the use of various security tokens including X.509 certificates, SAML assertions, and username/password tokens to authenticate and encrypt SOAP web services messages. The WS-Security specification can be viewed at http://www.oasis-open.org/committees/download.php/3281/WSS-SOAPMessageSecurity-17-082703-merged.pdf
WS-Security incorporates security features in the header of a SOAP message, working in the application layer. Message security differs from transport layer security (which is what is discussed in this chapter) in that message security can be used to decouple message protection from message transport so that messages remain protected after transmission, ensuring end-to-end security.
Sun's implementation of WS-Security is part of Metro, a web service stack. In the past, web services have relied on transport-based security such as SSL to provide point-to-point security. Metro implements the WS-Security specification to provide interoperable message content integrity and confidentiality, even in the presence of intermediaries. Metro also provides an implementation of the WS-Trust specification as a means for issuing, renewing, and validating security tokens used by WS-Security, and to establish and broker trust relationships. That portion of Metro is known as WSIT (Web Services Interoperability Technologies). Metro's WSIT subsystem is an implementation of a number of open web services specifications to support enterprise features. In addition to security, reliable messaging, and atomic transactions, Metro includes a bootstrapping and configuration technology.
Message security is not part of the Java EE 6 platform, but can be used with and by Java EE 6 applications by following the instructions from the Metro User's Guide at https://metro.dev.java.net/guide/.