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Problem: Multiple Web Browsers do not do not validate CN on certificates.
From: "Simson L. Garfinkel" <simsong () nitroba com>
Date: Wed, 7 May 2003 13:06:56 -0400 (EDT)

Problem: Multiple Web Browsers do not do not validate CN on certificates.

Effected Versons:
         Safari 1.0 Beta (v60)
         Safari 1.0 Beta 2 (v73)
         Konqueror Embedded (unknown version; common browser on Open Zaurus)
         [NOTE: Konquror 3.0.5 does not exhibit the problem.]

Both versions of Safari were tested on MacOS 10.2.5 and 10.2.6.



While doing work for an article on PKI, Jesse Burns and I discovered
that Apple's Safari web browser does not validate the Common Name (CN)
field on X.509 certificates that are downloaded to the client at the
start of SSL/TLS sessions. This bug is particularly annoying because
there is no way that we can find inside Safari to view the contents of
a certificate; double-clicking on the "lock" icon does nothing.

We are divided on whether or not this is a serious bug: Jesse feels
that it is sufficient reason that people should stop using
Safari until it is fixed. Simson feels that PKI has been deployed so poorly and is so
meaningless that it really doesn't matter if Safari validates
certificiates or not. 

Test vectors:
     1. https://www.sandstorm.net/
     2. https://bugreporter.apple.com/


Regarding Test Vector #1: 

Sandstorm's home page is web-hosted at Vineyard.NET, a small ISP on
Martha's Vineyard. Because Vineyard.NET multi-homes its clients, the
IP address 204.17.195.91 is shared by both www.sandstorm.net and
Vineyard.NET's administrative server, www.vineyard.net. However,
because VIneyard.NET has enabled SSL only for its own internal use and
not for its customers, 204.17.195.91:443 points to www.vineyard.net,
and the certficiate at 204.17.195.91:443 is Vineyard.NET's.

Regarding Test Vector #2:

A "GET /" at https://bugreporter.apple.com/ retrieves a JavaScript
document that executes the following:

<!--
 function time() {
 setTimeout("window.location.replace('https://bugreport.apple.com/cgi-bin/WebObjects/RadarWeb.woa&apos;)",10)
 }

This does a second GET at a new domain; the certificate at
https://bugreporter.apple.com/ actually has the common name of
bugreport.apple.com.



Internet Explorer 5.2.2 (5010.1) on MacOS did not exhibit the problem;
it reported that the common name on the certificate did not match the
entered DNS address with both of the two test vectors. The same
behavior was seen with Internet Explorer 5.5 on Windows. The same
behavior was seen with Opera 7.10 on Windows.


Apple Computer has been been notified of this bug.

Simson L. Garfinkel                           Jesse Burns
MIT Laboratory for Computer Science           jesse () ex com
simsong () lcs mit edu



Here is the full www.sandstorm.net certificate:

[simsong () r2 scan] 346 % openssl s_client -connect www.sandstorm.net:443
CONNECTED(00000003)
depth=0 /C=US/ST=Massachusetts/L=Vineyard Haven/O=Vineyard.NET, Inc./OU=Terms of use at www.verisign.com/rpa 
(c)00/CN=www.vineyard.net
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 /C=US/ST=Massachusetts/L=Vineyard Haven/O=Vineyard.NET, Inc./OU=Terms of use at www.verisign.com/rpa 
(c)00/CN=www.vineyard.net
verify error:num=27:certificate not trusted
verify return:1
depth=0 /C=US/ST=Massachusetts/L=Vineyard Haven/O=Vineyard.NET, Inc./OU=Terms of use at www.verisign.com/rpa 
(c)00/CN=www.vineyard.net
verify error:num=21:unable to verify the first certificate
verify return:1
---
Certificate chain
 0 s:/C=US/ST=Massachusetts/L=Vineyard Haven/O=Vineyard.NET, Inc./OU=Terms of use at www.verisign.com/rpa 
(c)00/CN=www.vineyard.net
   i:/C=US/O=RSA Data Security, Inc./OU=Secure Server Certification Authority
---
Server certificate
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
subject=/C=US/ST=Massachusetts/L=Vineyard Haven/O=Vineyard.NET, Inc./OU=Terms of use at www.verisign.com/rpa 
(c)00/CN=www.vineyard.net
issuer=/C=US/O=RSA Data Security, Inc./OU=Secure Server Certification Authority
---
No client certificate CA names sent
---
SSL handshake has read 1454 bytes and written 314 bytes
---
New, TLSv1/SSLv3, Cipher is EDH-RSA-DES-CBC3-SHA
Server public key is 1024 bit
SSL-Session:
    Protocol  : TLSv1
    Cipher    : EDH-RSA-DES-CBC3-SHA
    Session-ID: 
    Session-ID-ctx: 
    Master-Key: 4AD7B59E9D9D3E8953B17B293153A7D104C6CC023E7EC5877FFCAB5D9DD16695F8E867C47D5A656842A352E3EB568F8C
    Key-Arg   : None
    Start Time: 1052273380
    Timeout   : 300 (sec)
    Verify return code: 21 (unable to verify the first certificate)
---
^C


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