Re: [openssl-dev] [openssl.org #4612] Appcrash on SSL_CTX_new(SSLv2_server_method()) on windows 7 x64 with OpenSSL-1.0.1t

[Viktor Kolodrevskiy]

Hi,

If I want to enable ssl2 under windows build, will need to pass parameters:

    no-asm enable-ssl2 -DOPENSSL_USE_IPV6=0 VC-WIN32

So if I will need to build openssl under linux, parameters should be:

    no-asm enable-ssl2 -DOPENSSL_USE_IPV6=0

Is that right?

On Jul 11, 2016, at 20:20, Kurt Cancemi via RT <r...@openssl.org> wrote:

Hello,

In 1.0.1s OpenSSL disabled SSLv2 by default in the build. So use perl Configure no-asm enable-ssl2 -DOPENSSL_USE_IPV6=0 VC-WIN32

Excerpt from CHANGES

"Changes between 1.0.1r and 1.0.1s [1 Mar 2016]"
“
Disable SSLv2 default build, default negotiation and weak ciphers.  SSLv2
   is by default disabled at build-time.  Builds that are not configured with
   "enable-ssl2" will not support SSLv2.  Even if "enable-ssl2" is used,
   users who want to negotiate SSLv2 via the version-flexible SSLv23_method()
   will need to explicitly call either of:

       SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2);
   or
       SSL_clear_options(ssl, SSL_OP_NO_SSLv2);

   as appropriate.  Even if either of those is used, or the application
   explicitly uses the version-specific SSLv2_method() or its client and
   server variants, SSLv2 ciphers vulnerable to exhaustive search key
   recovery have been removed.  Specifically, the SSLv2 40-bit EXPORT
   ciphers, and SSLv2 56-bit DES are no longer available.
   (CVE-2016-0800)”

I highly advise you to stay clear of SSLv2 as it has numerous flaws. You are receiving crashes because SSLv2_server_method() returns NULL and SSL_CTX_new() returns NULL because the input argument (the server method) is NULL. You should check the return value of SSL_CTX_new() no matter what because it can fail.

Kurt Cancemi
ku...@x64architecture.com

On Jul 11, 2016, at 08:10, Dmytro Shamatrin via RT <r...@openssl.org> wrote:

Appcrash on SSL_CTX_new(SSLv2_server_method()) on windows 7 x64 with OpenSSL-1.0.1t

After upgrade from OpenSSL-1.0.1L version to 1.0.1t we got Appcrash on windows machine. After investigation I found that it started to happen after R version. 

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[Viktor Kolodrevskiy via RT]

Hi,

Is that right?

> Ticket here: http://rt.openssl.org/Ticket/Display.html?id=4612 <http://rt.openssl.org/Ticket/Display.html?id=4612>

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[Kaduk, Ben via RT]

On 08/03/2016 10:12 AM, Viktor Kolodrevskiy wrote:
> Hi,
>
> If I want to enable ssl2 under windows build, will need to pass
> parameters:
> no-asm enable-ssl2 -DOPENSSL_USE_IPV6=0 VC-WIN32
>
> So if I will need to build openssl under linux, parameters should be:
> no-asm enable-ssl2 -DOPENSSL_USE_IPV6=0
>
> Is that right?
>

You still need to pass an os/compiler argument to Configure for linux,
something like linux-x86_64 or linux-elf, presumably.

If you use config instead of Configure, there is autodetection of which
os/compiler to use, so no os/compiler argument is needed.

-Ben