SSL Trust Pitfalls

Prof. Ravi Sandhu

2© Ravi Sandhu 2006

SERVER-SIDE SSL (OR 1-WAY) HANDSHAKE WITH RSA

Client Server ClientHello --------> ServerHello Certificate <-------- ServerHelloDone ClientKeyExchange [ChangeCipherSpec] Finished --------> [ChangeCipherSpec] <-------- Finished Application Data <-------> Application Data

RecordProtocol

HandshakeProtocol

3© Ravi Sandhu 2006

CLIENT-SIDE SSL (OR 2-WAY) HANDSHAKE WITH RSA

Client Server ClientHello --------> ServerHello Certificate CertificateRequest <-------- ServerHelloDone Certificate ClientKeyExchange CertificateVerify [ChangeCipherSpec] Finished --------> [ChangeCipherSpec] <-------- Finished Application Data <-------> Application Data

RecordProtocol

HandshakeProtocol

4© Ravi Sandhu 2006

MULTIPLE ROOT CA’s PLUS INTERMEDIATE CA’s MODEL

X

Q

A

R

S T

C E G I K M O

a b c d e f g h i j k l m n o p

5© Ravi Sandhu 2006

MULTIPLE ROOT CA’s PLUS INTERMEDIATE CA’s MODEL

Essentially the model on the web today

Deployed in server-side SSL mode Client-side SSL mode yet to happen

6© Ravi Sandhu 2006

SERVER-SIDE MASQUARADING

BobWeb browser

www.host.comWeb serverServer-side SSL

UltratrustSecurityServices

www.host.com

7© Ravi Sandhu 2006

SERVER-SIDE MASQUARADING

BobWeb browser

www.host.comWeb server

Server-side SSL UltratrustSecurityServices

www.host.comMallory’sWeb server

BIMMCorporation

www.host.com

Server-side SSL

8© Ravi Sandhu 2006

SERVER-SIDE MASQUARADING

BobWeb browser

www.host.comWeb server

Server-side SSL UltratrustSecurityServices

www.host.comMallory’sWeb server

Server-side SSL

BIMMCorporation

UltratrustSecurityServices

www.host.com

9© Ravi Sandhu 2006

REFERENCES

"The problem with multiple roots in Web browsers-certificate masquerading" by Hayes, J.M. Proceedings Seventh IEEE International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises, IEEE 1998. (WET ICE '98) 17-19 June 1998 Page(s): 306 -311.