[cap-talk] RFC 2818 and Petname

Bill Frantz frantz at pwpconsult.com
Fri Dec 5 00:57:13 EST 2008


RFC 2818 says:

   In general, HTTP/TLS requests are generated by dereferencing a URI.
   As a consequence, the hostname for the server is known to the client.
   If the hostname is available, the client MUST check it against the
   server's identity as presented in the server's Certificate message,
   in order to prevent man-in-the-middle attacks.

   ...

   Note that in many cases the URI itself comes from an untrusted
   source. The above-described check provides no protection against
   attacks where this source is compromised. For example, if the URI was
   obtained by clicking on an HTML page which was itself obtained
   without using HTTP/TLS, a man in the middle could have replaced the
   URI.  In order to prevent this form of attack, users should carefully
   examine the certificate presented by the server to determine if it
   meets their expectations.

And the Petname tool is one way of carefully examining the certificate. :-)

Cheers - Bill

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