The RFC defines a mechanism for securely identifying originators of SIP messages, a transitive authentication system, building signature over SIP message body and relevant headers, like From, To, Date, Call-Id, CSeq, Contact.
Among immediate benefits are protection again man-in-the-middle attacks, registration hijacking or Caller ID spoofing.
The module offers two main services:
- authorizer - authorizes a message and adds Identity and Identity-Info headers
- verifier - verifies an authorized message
The series continues with: secure and scalable XMLRPC control interface.