[openssl-dev] [openssl.org #4612] Appcrash on SSL_CTX_new(SSLv2_server_method()) on windows 7 x64 with OpenSSL-1.0.1t
Viktor Kolodrevskiy
viktor.kolodrevskiy at gmail.com
Wed Aug 3 15:12:07 UTC 2016
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 <rt at 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
> kurt at x64architecture.com
>
>> On Jul 11, 2016, at 08:10, Dmytro Shamatrin via RT <rt at 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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