Re: [TLS] Verifying X.509 Certificate Chains out of order

Martin Rex <> Tue, 07 October 2008 11:43 UTC

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From: Martin Rex <>
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Date: Tue, 7 Oct 2008 13:43:53 +0200 (MEST)
In-Reply-To: <> from "Martin Rex" at Oct 7, 8 01:09:57 pm
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Subject: Re: [TLS] Verifying X.509 Certificate Chains out of order
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Martin Rex wrote:
> Stefan Santesson wrote:
> > 
> > Just agreeing on the principle that implementers should be forced to
> > send the certificates in order but it definitely must be allowed
> > to accept out of order chains.
> I have absolutely no problem with implementations that accept an
> unordered list.

Thinking about it, what exactly do you mean with unordered?

Since there isn't any additional information in the protocol to
identity the end-entity cert in the certificate_list, that certificate
will have to be the first.  Or does your code really apply heuristics
in locating the end entity cert?

In PKCS#7 there is the the signerinfos (issuer&serial) that make the
search in the unordered and only loosely related CertificateAndCertificates
bag at least deterministic (not purely heuristic).

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