I was show casing the SSLStrip tool in my office. Everybody was asking how it works. Security Researcher Moxie had released two tools SSLSniff and SSLStrip during Black Hat 2009. These tools were capable of doing MITM on SSL connection. They exploited a weakness in signing the certificates. SSL heavily rely on X509 certificate structure to prove authenticity. For the SSL it is the 'common name field' of the X509 certificate that is used to identify authentic servers. For example, Paypal will used 'www.paypal.com' in the common name field. The signing process heavily relies on the above convention. The Certificate Authorities will sign 'www.paypal.com', they don't care whether you are requesting for 'anything.paypal.com' or 'anything1.anything.paypal.com'- as long as you prove that you are paypal .com. The Trick: X509 certificates are commonly formatted using ASN .1 notation. ASN .1 supports many string types but all of them are repr...