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Re: [TLS] Deprecate SHA1 for signatures in TLS 1.3 (was Re: TLS 1.3 draft-07 sneak peek)

Henrik Grubbström <grubba@gmail.com> Thu, 09 July 2015 14:14 UTC

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Date: Thu, 09 Jul 2015 16:14:42 +0200
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From: Henrik Grubbström <grubba@gmail.com>
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Subject: Re: [TLS] Deprecate SHA1 for signatures in TLS 1.3 (was Re: TLS 1.3 draft-07 sneak peek)
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On Wed, Jul 8, 2015 at 8:07 PM, Martin Rex <mrex@sap.com> wrote:
> The issue here is the (lack of the) TLSv1.2 signature_algorithms extension.
>
> Windows SChannel appears to treat the absence of this extension
> the same as the presence of an extension with (md5,rsa) (sha1,rsa) (sha1,dsa)
>
> If you send the TLSv1.2 signature_algorithms extension with the
> algorithm matching the signature of the server certificate,
> e.g. (sha256,rsa) in the above example, then a TLSv1.2 handshake will succeed.

Sounds like it is complying with the TLS v1.2 RFC. Fix your client.

-- 
Henrik Grubbström                                       grubba@grubba.org
Roxen Internet Software AB                              grubba@roxen.com

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