Fortran can call managed code only if assembly was compiled with "ComVisible(true)" attribute and with "Register for COM interop" build setting. "ComputeHash" is not COM-visible. In this case it's possible to create new "wrapper" .net assembly with COM-visible "SHA256_ComputeHash" method and build it with "Register for COM interop". After that "SHA256_ComputeHash" will we accesible from Fortran via code generated by "Intel(R) Visual Fortran Module Wizard".