[openssl-users] Getting error 'SSLv2_client_method': identifier not found

[Tony Girgenti]

Michael,

 

Thank you for your explanation of where my program is and what I should do
to continue using some kind of SSL.

 

I first need to figure out how this program uses SSL.  Then I can go ahead
and try to use TLSv1.2.

 

I did try to use "SSLv23_client_method" and got the same compile error
"LNK2026          module unsafe for SAFESEH image.".

 

Thanks,
Tony

 

From: openssl-users [mailto:openssl-users-bounces at openssl.org] On Behalf Of
Michael Wojcik
Sent: Monday, June 27, 2016 3:50 PM
To: openssl-users at openssl.org
Subject: Re: [openssl-users] Getting error 'SSLv2_client_method': identifier
not found

 

SSLv2 is no longer supported, and neither are the SSLv2_*_method calls. (And
yes, this causes build problems when updating to newer OpenSSL builds; and
while that causes some pain, it was the Right Thing to do.)

 

As Rich said, don't use SSLv2. Don't use SSLv3. If you can help it, don't
use anything older than TLSv1.2.

 

The simplest fix is to change "SSLv2_client_method" to
"SSLv23_client_method". (Inserting a single character; can't get much
simpler than that.) But since you really don't want to talk to a server that
only supports SSLv3, you might as well use TLSv1_client_method instead, or
even better TLSv1_2_client_method. Since we have no idea what your program
does, or what it has to interoperate with, we can't offer any more-specific
advice.

 

SSLv23_client_method will use the old SSL-format ClientHello, but will
(barring more-restrictive options set using SSL_CTX_set_options or similar)
use later protocol versions for the actual conversation if the server
supports them.

 

All that said, by far the best approach is to learn how TLS and OpenSSL
work, so you can make an informed decision. TLS is agonizingly complicated
and a minefield of security holes, and TLS applications maintained by people
who don't have the necessary specialized knowledge are very likely to be
severely insecure. For example, they may try to use SSLv2, which has been
broken for a couple of decades. (That is, it's been broken for as long as it
existed, but it's been widely known to be broken since the mid-1990s.)

 

Feistyduck.com has a free "OpenSSL cookbook" ebook which is a decent
introduction.

 

Michael Wojcik 
Technology Specialist, Micro Focus 

 

 

From: openssl-users [mailto:openssl-users-bounces at openssl.org] On Behalf Of
Tony Girgenti
Sent: Monday, June 27, 2016 13:09
To: openssl-users at openssl.org <mailto:openssl-users at openssl.org> 
Subject: [openssl-users] Getting error 'SSLv2_client_method': identifier not
found

 

Hello,

 

I migrated a Visual Studio 6.0 C++ program to Visual Studio 2015 C++.  The
program uses OpenSSL.  I have downloaded and installed OpenSSL-Win32 version
1.0.2g.

 

I'm trying to figure what I need to do to fix the error I am getting on this
line: m_pSSLctx = SSL_CTX_new(SSLv2_client_method());

 

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