20 messages in ru.sysoev.nginxRe: New SSL features for Nginx.
FromSent OnAttachments
Brice FigureauJul 21, 2009 11:01 am 
Igor SysoevJul 22, 2009 1:43 am 
Brice FigureauJul 22, 2009 3:21 am 
Brice FigureauJul 22, 2009 4:39 am 
Igor SysoevJul 22, 2009 5:15 am 
Igor SysoevJul 22, 2009 7:52 am.optional
Brice FigureauJul 22, 2009 10:15 am 
Brice FigureauJul 22, 2009 10:20 am 
Igor SysoevJul 22, 2009 11:38 am 
Igor SysoevJul 22, 2009 11:42 am 
Brice FigureauJul 22, 2009 12:13 pm 
Igor SysoevJul 22, 2009 12:23 pm 
Brice FigureauJul 22, 2009 2:17 pm 
Tom KeyserJul 22, 2009 5:50 pm 
Glen LumanauJul 22, 2009 5:59 pm 
Edward MiddletonJul 22, 2009 7:26 pm 
Cliff WellsJul 22, 2009 8:22 pm 
Igor SysoevJul 23, 2009 12:08 am 
Igor SysoevJul 23, 2009 12:56 am.crl
Brice FigureauJul 23, 2009 4:32 am 
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Subject:Re: New SSL features for Nginx.Actions...
From:Brice Figureau (bric@daysofwonder.com)
Date:Jul 22, 2009 10:20:16 am
List:ru.sysoev.nginx

On 22/07/09 14:16, Igor Sysoev wrote:

On Wed, Jul 22, 2009 at 12:21:23PM +0200, Brice Figureau wrote:

Hi Igor,

On Wed, 2009-07-22 at 12:44 +0400, Igor Sysoev wrote:

On Tue, Jul 21, 2009 at 08:02:05PM +0200, Brice Figureau wrote:

Hi,

For Puppet[1] Nginx deployement (that is using Nginx as a front-end load-balancers to puppetmasters[2]), I had to create the following two patches, to match Apache behaviour:

* The first patch allows: + a new variant of ssl_client_verify: optional. In this mode, if the client sends a certificate it is verified, but if the client doesn't send a certificate, the connection is authorized too.

+ a new variable: $ssl_client_verify which contains, either NONE, SUCCESS or FAILURE depending on the verification status. It can be used to send information to the upstream about the client verification.

* The second patch adds CRL support to the client certificate verification:

ssl_crl /path/to/crl.pem;

Nginx then verifies the client certificate hasn't been revoked in the given CRL before allowing the connection to proceed.

For access to the patches, please see my last blog article: http://www.masterzen.fr/2009/07/21/new-ssl-features-for-nginx/

It would be great if those patches could be merged in the official Nginx source tree.

Thank you, I have looked the patches, it was really surpise for me that OpenSSL 0.9.7 supports CRL. I read in old enough book "Network Security with OpenSSL" written when 0.9.7 was being developed, that OpenSSL has no built-in CRL support.

Ah, ok. I based all my development on OpenSSL 0.9.8, since that's what I'm building Nginx againt. And definitely there is CRL support. Is OpenSSL 0.9.7 a strict dependency for Nginx?

No. I think this code should be just "#ifdef'ed X509_V_FLAG_CRL_CHECK".

I'm OK with this. BTW, I checked and CRL support was added in 0.9.7.

Then I have looked in Apache's mod_ssl sources and its CRL support seemed to me very heavy: mod_ssl does a lot of useless operations.

Which ones? What I don't get is why they're doing the CRL verification themselves.

Because mod_ssl were developed before 0.9.7.

Yes, I do think so. But it's error-prone and certainly less efficient.

I found this comment in the code: * OpenSSL provides the general mechanism to deal with CRLs but does not * use them automatically when verifying certificates, so we do it * explicitly here. We will check the CRL for the currently checked * certificate, if there is such a CRL in the store.

This seems wrong to me, as I already tested, and it works fine at least in version 0.9.8.

Yes, this implementation. However, I made mistake: it's not too heavy as it seemed to me first time I have looked.

I think that it's enough to store hash of only public key of all CRL certificates (including intermediate ones).

Why reinvent the wheel? The CRL is a standard thing (see RFC 3280), and basically this is a DER encoded ASN1 structure containing the list of the revoked certificates serial number, signed by the CA cert.

Have you looked how CRL is implemented in OpenSSL ?

Yes, I did. It is pretty extensive, and matches RFC3280.

I'll fetch OpenSSL 0.9.7 to see if it supports or not CRL, but I'd be suprised it wouldn't.

0.9.7 definitely supports CRL verification.

Thanks for reviewing the patch (at least the first one could be merged, isn't it?).

Probabaly, I will commit the patches in next 0.8.7.

Will you merge the CRL one (feel free to rewrite it if you prefer), too ?

Thanks,

-- Brice Figureau My Blog: http://www.masterzen.fr/