#include <stdio.h>
#include <dlfcn.h>

typedef int (*functype) (void*, void*, const void*, unsigned int, unsigned);

int main (int argc, char** argv)
{
void* module1 = dlopen("/opt/cprocsp/lib/amd64/libcapi10.so", RTLD_GLOBAL | RTLD_LAZY);
void* module2 = dlopen("/opt/cprocsp/lib/amd64/libcapi20.so", RTLD_GLOBAL | RTLD_LAZY);

printf("module1 = 0x%08x, module2 = 0x%08x\n", module1, module2);

void* func1 = dlsym(module1, "CryptAcquireContextW");
void* func2 = dlsym(module2, "CryptAcquireContextW");

printf ("func1 = 0x%08x, func2 = 0x%08x\n", func1, func2);

functype* f = (functype*)(func1 ? func1 : func2);

char prov[256];
void* container = 0;
const wchar_t* provider = L"Crypto-Pro GOST R 34.10-2001 Cryptographic Service Provider";
unsigned type = 75;
unsigned flags = 4026531840;

int ret = (*f)(&prov[0], container, provider, type, flags);
printf("ret = %d\n", ret);

return 0;
}

/usr/local/lib/64/libcurl.so: cannot open shared object file: No such file or directory
module1 = 0x01f5b040, module2 = 0x01f5d8f0
func1 = 0x00a46a80, func2 = 0x00a46a80
Segmentation fault (core dumped)

g++ -Wall -w -g3 -c -o test.o test.cpp
g++ -ldl -o test test.o

[ruslan@cs-redhat6-satr ~]$ gdb ./test
GNU gdb (GDB) Red Hat Enterprise Linux (7.2-60.el6_4.1)
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /home/ruslan/test...done.
(gdb) r
Starting program: /home/ruslan/test
[Thread debugging using libthread_db enabled]
support_dlopen() = 0x(nil) fail (1)
/usr/local/lib/64/libcurl.so: cannot open shared object file: No such file or directory
module1 = 0x00601040, module2 = 0x006038f0
func1 = 0xf7edea80, func2 = 0xf7edea80

Program received signal SIGSEGV, Segmentation fault.
0x0000000000400759 in main (argc=1, argv=0x7fffffffe5e8) at test.cpp:26
26 int ret = (*f)(&prov[0], container, provider, type, flags);

[ruslan@cs-redhat6-satr ~]$ ldd -r /opt/cprocsp/lib/amd64/libcapi10.so
linux-vdso.so.1 => (0x00007ffffabb3000)
librdrsup.so.3 => /opt/cprocsp/lib/amd64/librdrsup.so.3 (0x00007f86e5b3d000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f86e5939000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f86e571b000)
libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f86e5415000)
libm.so.6 => /lib64/libm.so.6 (0x00007f86e5191000)
libc.so.6 => /lib64/libc.so.6 (0x00007f86e4dfc000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f86e4be6000)
/lib64/ld-linux-x86-64.so.2 (0x000000357f200000)
[ruslan@cs-redhat6-satr ~]$ ldd -r /opt/cprocsp/lib/amd64/libcapi20.so
linux-vdso.so.1 => (0x00007fffcb1ff000)
libcpext.so.3 => /opt/cprocsp/lib/amd64/libcpext.so.3 (0x00007f2d4b0ec000)
libcapi10.so.3 => /opt/cprocsp/lib/amd64/libcapi10.so.3 (0x00007f2d4afd8000)
libasn1data.so.3 => /opt/cprocsp/lib/amd64/libasn1data.so.3 (0x00007f2d4a892000)
librdrsup.so.3 => /opt/cprocsp/lib/amd64/librdrsup.so.3 (0x00007f2d4a77a000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f2d4a576000)
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f2d4a358000)
libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00007f2d4a052000)
libm.so.6 => /lib64/libm.so.6 (0x00007f2d49dce000)
libc.so.6 => /lib64/libc.so.6 (0x00007f2d49a39000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f2d49823000)
/lib64/ld-linux-x86-64.so.2 (0x000000357f200000)