Re: Segmentation fault in s23_clnt.c when used in a library

[Tobias Ljunggren <tljunggren@gmail.com>]

Hello,

I just found what's causing the crash. The application that loads my library already have some of the openSSL functions. Either 
they have copied the source code or statically linked to openSSL. Because of this openLDAP sometimes uses the wrong functions 
(SSL_new is one of them).

I guess my only option is to build openLDAP with a static linkage to openSSL?

Best regards,
Tobias

On 2014-10-07 17:06, Tobias Ljunggren wrote:
> Hello,
>
> I've been trying to track a segmentation fault for a couple of days but I'm running out of ideas and need some help or 
> suggestion on how to proceed.
>
> Perhaps this is the wrong forum and if so I apologize. It's also worth mentioning that I don't have any knowledge about the 
> openSSL library source code but I've been working with ldap libraries for quite some time (about 10 years).
>
> What I have is shared object (.so) that is loaded from another program (nothing I have control of) using a public API. My 
> library loads openLDAP (libldap_r and liblber) using dlopen/dlsym. After some initialization code I try to bind to a ldap 
> source (ldaps://ldaphost:636)  but I get a segmentation fault in s23_clnt.c at line 159:
> else if (s->ctx->info_callback != NULL)
>
> For some reason s->ctx is a null pointer. My first thoughts was that I do something I shouldn't prior to ldap_sasl_bind_s 
> which corrupts the LDAP handle but after days with gdb and valgrind I still can't find anything.
>
> openLDAP version used is 2.4.40 built with openSSL 1.0.1i.
>
> If I copy the ldap code to a test executable it works fine.
>
> Is there anything special to consider when loading the libraries from a shared object?
>
> I understand that it is almost impossible to give me any good answers but since I'm a bit frustrated I hope someone can give 
> me some hints.
>
> Best regards,
> Tobias