Extentions of the explanations to the linking problem on Win32. Provided by...

* I've compiled a program under Windows and it crashes: why?

This is usually because you've missed the comment in INSTALL.W32. You

must link with the multithreaded DLL version of the VC++ runtime library

otherwise the conflict will cause a program to crash: typically on the

first BIO related read or write operation.

This is usually because you've missed the comment in INSTALL.W32.

Your application must link against the same version of the Win32

C-Runtime against which your openssl libraries were linked.  The

default version for OpenSSL is /MD - "Multithreaded DLL".

If you are using Microsoft Visual C++'s IDE (Visual Studio), in

many cases, your new project most likely defaulted to "Debug

Singlethreaded" - /ML.  This is NOT interchangeable with /MD and your

program will crash, typically on the first BIO related read or write

operation.

For each of the six possible link stage configurations within Win32,

your application must link  against the same by which OpenSSL was

built.  If you are using MS Visual C++ (Studio) this can be changed

by:

1.  Select Settings... from the Project Menu.

2.  Select the C/C++ Tab.

3.  Select "Code Generation from the "Category" drop down list box

4.  Select the Appropriate library (see table below) from the "Use

    run-time library" drop down list box.  Perform this step for both

    your debug and release versions of your application (look at the

    top left of the settings panel to change between the two)

    Single Threaded           /ML        -  MS VC++ often defaults to

                                            this for the release

                                            version of a new project.

    Debug Single Threaded     /MLd       -  MS VC++ often defaults to

                                            this for the debug version

                                            of a new project.

    Multithreaded             /MT

    Debug Multithreaded       /MTd

    Multithreaded DLL         /MD        -  OpenSSL defaults to this.

    Debug Multithreaded DLL   /MDd

Note that debug and release libraries are NOT interchangeable.  If you

built OpenSSL with /MD your application must use /MD and cannot use /MDd.

* How do I read or write a DER encoded buffer using the ASN1 functions?