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Have you reasons to believe the existing x509 certificates handling code handles properly an extension that is seldom used, and will do it in all cases? Valida

• brohee 12y ago
  I wonder about the downvotes, with the long documented history of software failing to properly validate certificate chains (or worse, trees). See for example http://blog.codekills.net/2012/04/08/adventures-in-x509-the-utterly-ignored-nameconstraints/ http://blog.codekills.net/2012/04/08/adventures-in-x509-the-... about what really happens when one steps outside the well traveled path of certificate attributes...
• briansmith 12y ago
  Some implementations--most unfortunately, Apple's--do not implement name constraints. Speaking from personal experience, writing code to correctly validate x509 certificates isn't as hard as it looks.
  • brohee 12y ago
    Then you're likely in the top 10 experts of the field ;) The fact that OpenSSL did it wrong for 15 years doesn't bode well for the myriads of TLS implementations that are around. My experience with the x509 part of SSL/TLS stacks is really not good when you start to use something else than OpenSSL/NSS (well PolarSSL is pretty good too). Quite often there is enough implemented to interoperate in the common use cases, but you're on your own if you need a complete standard support... Then it has been a while, maybe it's a lot better now.