certificate problem for *.github.com

certificate problem for *.github.com

[Mattia Tomasoni]

Hello Git community!
Here is my question: until a few days ago I used to be able to point  
to a certain file in my git repository with the following url:
http://github.com/percolator/percolator/raw/xml-1-1/src/xml/percolator_in.xsd
Now this gets redirected to an https address.
No problem opening it with the browser; but I do get an error with,  
for instance, wget (...and, more important, with a program that  
attempts to use that file as a schema against which some xml code is  
validated...)
I get:
certificate common name `*.github.com' doesn't match requested host  
name `github.com'

wget --no-check-certificate works...

Thank you!
Mattia

Re: certificate problem for *.github.com

[Jeff King]

On Thu, Nov 04, 2010 at 04:21:35PM +0100, Mattia Tomasoni wrote:

> I get:
> certificate common name `*.github.com' doesn't match requested host
> name `github.com'
> 
> wget --no-check-certificate works...

The problem is that wildcard names in certificates are not
well-specified. RFC 2818 leaves this particular case (matching
"*.domain" to "domain") ambiguous:

  Names may contain the wildcard character * which is considered to
  match any single domain name component or component fragment. E.g.,
  *.a.com matches foo.a.com but not bar.foo.a.com. f*.com matches
  foo.com but not bar.com.

RFC 2595 specifically outlaws it, but is talking about other non-HTTP
protocols (it is for TLS with IMAP, POP, and ACAP):

  A "*" wildcard character MAY be used as the left-most name component
  in the certificate.  For example, *.example.com would match
  a.example.com, foo.example.com, etc. but would not match example.com.

So you can either send a bug report to wget to handle this case better,
or you can complain to github not to use wildcard certificates in this
way.

-Peff