WebServices - Security

 

One of the first questions newcomers to SOAP ask is how does SOAP deal with security. Early in its development, SOAP was seen as an HTTP-based protocol so the assumption was made that HTTP security would be adequate for SOAP. After all, there are thousands of Web applications running today using HTTP security so surely this is adequate for SOAP. For this reason, the current SOAP standard assumes security is a transport issue and is silent on security issues.

 

When SOAP expanded to become a more general-purpose protocol running on top of a number of transports, security became a bigger issue. For example, HTTP provides several ways to authenticate which user is making a SOAP call, but how does that identity get propagated when the message is routed from HTTP to an SMTP transport? SOAP was designed as a building-block protocol, so fortunately, there are already specifications in the works to build on SOAP to provide additional security features for Web services. The WS-Security specification defines a complete encryption system.