Intro to SSL/TLS

1. Intro to SSL/TLS Network Security Gene Itkis

2. Origins • Internet Engineering Task Force (IETF) • www.ietf.org • Documents: RFC 2246 • ANSI • X9.42 • ITU • X.509 • Netscape Gene Itkis: CS558 Network Security

3. History • 1993 – Mosaic (“browser #1”) • 1994 – Netscape Browser released • SSL v1 design complete – never released • SSL v2 released in Navigator 1.1 • Badly broken (bad seeds for PRNG) • 1995 – Explorer released • PCT (MS), SSL v3 (Netscape) • 1996-1999 – TLS 1.0 • 1999 – WTLS Gene Itkis: CS558 Network Security

4. Architecture Application (HTTP) SSL TCP IP Gene Itkis: CS558 Network Security

5. Alternative architectures • Separate Layer • Over TCP: SSL • Over IP: IPSec • Application-Specific • SHTTP • Parallel • Kerberos; Kerberos with TLS? Gene Itkis: CS558 Network Security

6. SSL choices • Connection-oriented • SSL, TLS do not support UDP • But WTLS does • No non-repudiation • But signatures are used for AKE • “Only protects the pipe” • Attacks are mounted on data before and after “the pipe” Gene Itkis: CS558 Network Security

7. SSL security services • Server authentication • Client authentication is optional • Encryption • Message integrity Gene Itkis: CS558 Network Security

8. SSL phases • Handshake • Set protocol details • Authenticate server • Establish keys • Data transfer Gene Itkis: CS558 Network Security

9. Handshake • ClientHello • Supported options • ServerHello • Options to be used • ServerCertificate (ServerKeyExchange) • ServerHelloDone • ClientKeyExchange • Finished (sent by client) Gene Itkis: CS558 Network Security