'[stunnel-users] public domain [PATCH] to stunnel v456 to clear SSL_OP_LEGACY_SERVER_CONNECT'

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List: stunnel-users
Subject: [stunnel-users] public domain [PATCH] to stunnel v456 to clear SSL_OP_LEGACY_SERVER_CONNECT
From: "Simner, John" <john.simner () unify ! com>
Date: 2014-06-25 13:34:31
Message-ID: 5B74BA474FDDA4418CCD02CA71FBCA8A44EEC8AC () MCHP03MSX ! global-ad ! net
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Dear Michal, Dear All,
Please find attached a patch to stunnel 4.56 to clear SSL_OP_LEGACY_SERVER_=
CONNECT.

There was a security requirement to ensure that the stunnel client could no=
t connect to unpatched servers.

I am aware from OpenSSL (https://www.openssl.org/docs/ssl/SSL_CTX_set_optio=
ns.html ) that this parameter is currently set by default and has to be man=
ually cleared by calling SSL_CTX_clear_options() or SSL_clear_options()if a=
n OpenSSL client applications wants to ensure they can not connect to unpat=
ched servers (and thus avoid any security issues).

The attached patch achieves this.

OpenSSL also state "As more servers become patched the option SSL_OP_LEGACY=
_SERVER_CONNECT will not be set by default in a future version of OpenSSL" =
so this patch is only required until OpenSSL change the default value.

Thanks..
John



[Unify: Harmonize your enterprise]

John Simner BSc(Hons) MSc CEng. MIET
Software Engineer, Devices Development

Unify Enterprise Communications Ltd.

Tel.: +44 (1908) 817378 (One Number Service)
Email: john.simner@unify.com <mailto:vorname.name@unify.com>

www.unify.co.uk<http://www.unify.co.uk/>

Follow us: [Social_media_icons] <http://www.unify.com/social-media>

Unify Enterprise Communications Limited. Registered Office: Brickhill Stree=
t, Willen Lake, Milton Keynes, MK15 0DJ
Registered No: 5903714, England.

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f the addressee.
If you are not the addressee then any distribution, copying, or use of this=
 email is prohibited.
If received in error, please advise the sender and delete immediately. We a=
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Dear Michal, Dear All,<o:p></o:p>
Please find attached a patch to stunnel 4.56 to clear \
SSL_OP_LEGACY_SERVER_CONNECT.<o:p></o:p> <o:p>&nbsp;</o:p> There was a security \
requirement to ensure that the stunnel client could not connect to unpatched \
servers.<o:p></o:p> <o:p>&nbsp;</o:p>
I am aware from OpenSSL (<a \
href="https://www.openssl.org/docs/ssl/SSL_CTX_set_options.html">https://www.openssl.org/docs/ssl/SSL_CTX_set_options.html</a> \
) that this parameter is currently set by default and has to be manually cleared by \
calling <code>SSL_CTX_clear_options()</code> or \
<code>SSL_clear_options()</code>if an OpenSSL \
client applications wants to ensure they can not \
connect to unpatched servers (and thus avoid any security issues).<code><o:p></o:p></code> <code><o:p>&nbsp;</o:p></code> The \
attached patch achieves this.<o:p></o:p> <o:p>&nbsp;</o:p> OpenSSL also state \
&#8220;As more servers become patched the option SSL_OP_LEGACY_SERVER_CONNECT \
will not \
be set by default in a future version of OpenSSL&#8221; so this patch is only \
required until OpenSSL change the default value.<o:p></o:p> <o:p>&nbsp;</o:p> Thanks..<o:p></o:p>
John<o:p></o:p>
<code><o:p>&nbsp;</o:p></code> <o:p>&nbsp;</o:p> <o:p>&nbsp;</o:p>
<img \
border="0" width="172" height="22" id="Picture_x0020_1" \
src="cid:image001.gif@01CF9081.B548ECF0" alt="Unify: Harmonize your \
enterprise"><o:p></o:p>
 <o:p>&nbsp;</o:p>
 John \
Simner BSc(Hons) MSc CEng. MIET<o:p></o:p>
 Software \
Engineer, Devices Development<o:p></o:p> <o:p>&nbsp;</o:p>
 Unify \
Enterprise Communications Ltd.<o:p></o:p> <o:p>&nbsp;</o:p>
 Tel.: \
&#43;44 (1908) 817378 (One Number Service)<o:p></o:p> Email: \
<a href="mailto:vorname.name@unify.com">john.simner@unify.com </a><o:p></o:p> <o:p>&nbsp;</o:p> <a \
href="http://www.unify.co.uk/">www.unify.co.uk</a><o:p></o:p>
 <o:p>&nbsp;</o:p>
 Follow \
us:&nbsp;<a href="http://www.unify.com/social-media"><img \
border="0" width="132" height="14" id="Bild_x0020_1" \
src="cid:image002.png@01CF9081.B548ECF0" alt="Social_media_icons"></a>&nbsp;
 <o:p></o:p>
<o:p>&nbsp;</o:p>
 Unify \
Enterprise Communications Limited. Registered&nbsp;Office:&nbsp;Brickhill Street, \
Willen Lake, Milton Keynes, MK15 0DJ<o:p></o:p> Registered \
No: 5903714, England. <o:p></o:p>
&nbsp;<o:p></o:p>
 This \
email contains confidential information and is for the exclusive use of the \
addressee. <o:p></o:p>
If \
you are not the addressee then any distribution, copying, or use of this email is \
prohibited.<o:p></o:p> If \
received in error, please advise the sender and delete immediately. We accept no \
liability for any loss or damage suffered by any person arising from use of this \
email.<o:p></o:p>
 <o:p>&nbsp;</o:p>
<o:p>&nbsp;</o:p>
</div>
</body>
</html>


["image001.gif" (image/gif)]
["image002.png" (image/png)]
["noconnectunpatchedservers.patch" (application/octet-stream)]

--- stunnel-4.56/src/ctx.c	2013-03-19 16:27:09.000000000 +0000
+++ stunnel_patch-4.56/src/ctx.c	2014-06-24 15:49:46.000000000 +0100
@@ -146,6 +146,8 @@
         }
     s_log(LOG_DEBUG, "SSL options set: 0x%08lX",
         SSL_CTX_set_options(section->ctx, section->ssl_options));
+    s_log(LOG_DEBUG, "SSL options reset: 0x%08lX",
+        SSL_CTX_clear_options(section->ctx, SSL_OP_LEGACY_SERVER_CONNECT)); 
 #ifdef SSL_MODE_RELEASE_BUFFERS
     SSL_CTX_set_mode(section->ctx,
         SSL_MODE_ENABLE_PARTIAL_WRITE |


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