1. Security in WAP Sanket Naik, Ameya Varde CS590F Fall 2000

2. Motivation and Goals To study the security issues in WAP To analyze an existing implementation and implement enhancements To investigate security holes in the implementation and WAP in general To suggest improvements for both

3. Implementation WAP stack from Kannel (www.kannel.org)www.kannel.org An on-going open source project implementing the WAP stack No WTLS support WTLS layer from 3ui.com (www.3ui.com)www.3ui.com We identified 2 security enhancements: SSL connection between WAP gateway and Content (HTML) server Authentication of the WAP gateway by the WAP client Both missing in WTLS patch from 3ui

4. Kannel architecture

5. Security Enhancements

6. Development tools Platform – Linux OpenSSL crypto library (http://www.openssl.org)http://www.openssl.org NOKIA WAP Toolkit (http://www.forum.nokia.com)http://www.forum.nokia.com Simulates a web-enabled NOKIA 7110 phone

7. WTLS optimizations Why optimize? Low bandwidth Less processing power Less memory Weaker power supply The optimizations Abbreviated handshake – using pre-master secret from previous session Optional steps – Client can send NULL reply to Certificate request, Anonymous key exchange etc.

8. The flaws Encryption not truly end-to-end Abbreviated handshake susceptible to replay attack Chosen plain-text attack: IV for each packet = Sequence number XOR Original IV DOS attack: Alerts are unauthenticated Man-in-the-middle attack: 40 bit XOR MAC allows even bit changes Impersonation: Anonymous key exchange methods allow key generation w/o Authentication (Kannel WTLS has only anonymous key exchange methods!) Weaker encryption mechanisms due to export regulations

9. Suggestions WAP specifications Enforce Client authentication rather than keep it optional Make WTLS layer mandatory whether people use it or not. Implementation Provide Gateway authentication in WAP clients Add stronger algorithms, keys and key exchange methods to the cipher suites

10. Conclusions WTLS Specs propose weak security Developers and Manufacturers are deploying WAP stacks which do not meet even these weak security requirements Mostly due to lack of security expertise Open source exposing these weaknesses Yet additional code review required Our 2 bits should be checked in soon…