text: /*
   * Convenience pkcs11 library that can be linked into an application,
   * and will bind to a specific pkcs11 module.
   *
   * Copyright (C) 2002  Olaf Kirch <okir@lst.de>
   */
  
  #include "pkcs11.h"
  #include <stdlib.h>
  #include <stdio.h>
  #include <string.h>
  #ifdef __APPLE__
  #include <Carbon/Carbon.h>
  #endif
  
  #ifndef _WIN32
  #ifdef _WINDOWS
  #define _WIN32
  #endif
  #endif
  
  #define MAGIC			0xd00bed00
  
  struct sc_pkcs11_module {
  	unsigned int		_magic;
  #if defined(linux) || defined(_WIN32)
  	void *			_dl_handle;
  #endif
  #ifdef __APPLE__
  	struct mach_header	*_dl_handle;
  	CFBundleRef		bundleRef;  
  #endif
  };
  
  static int	sys_dlopen(sc_pkcs11_module_t *, const char *);
  static int	sys_dlclose(sc_pkcs11_module_t *);
  static void *	sys_dlsym(sc_pkcs11_module_t *, const char *);
  
  /*
   * Load a module - this will load the shared object, call
   * C_Initialize, and get the list of function pointers
   */
  sc_pkcs11_module_t *
  C_LoadModule(const char *mspec, CK_FUNCTION_LIST_PTR_PTR funcs)
  {
  	sc_pkcs11_module_t *mod;
  	CK_RV (*c_get_function_list)(CK_FUNCTION_LIST_PTR_PTR);
  	int rv;
  
  	mod = (sc_pkcs11_module_t *) calloc(1, sizeof(*mod));
  	mod->_magic = MAGIC;
      rv=sys_dlopen(mod,mspec);
  	if (rv < 0) {
    //      fprintf(stderr, "failed to sys_dlopen - returned %i", rv)
  		goto failed; 
      }
  
  	/* Get the list of function pointers */
  	c_get_function_list = (CK_RV (*)(CK_FUNCTION_LIST_PTR_PTR))
  				sys_dlsym(mod, "C_GetFunctionList");
  	if (!c_get_function_list) {
      //    fprintf(stderr, "failed to get function list");
  		goto failed;
      }
  	rv = c_get_function_list(funcs);
  	if (rv == CKR_OK)
  		return mod;
  
  failed:	C_UnloadModule(mod);
  	return NULL;
  }
  
  /*
   * Unload a pkcs11 module.
   * The calling application is responsible for cleaning up
   * and calling C_Finalize
   */
  CK_RV
  C_UnloadModule(sc_pkcs11_module_t *mod)
  {
  	if (!mod || mod->_magic != MAGIC)
  		return CKR_ARGUMENTS_BAD;
  
  	if (sys_dlclose(mod) < 0)
  		return CKR_FUNCTION_FAILED;
  
  	memset(mod, 0, sizeof(*mod));
  	free(mod);
  	return CKR_OK;
  }
  
  #ifdef linux
  #include <dlfcn.h>
  
  /*
   * Module loader for platforms that have dlopen
   *
   * This is intentionally primitive; we may want a more
   * elaborate loader in libopensc one day
   */
  int
  sys_dlopen(struct sc_pkcs11_module *mod, const char *name)
  {
  	const char	**dir, *ldlist[64];
  	char		pathbuf[4096], *ldenv;
  	unsigned int	n = 0;
  
  	if ((ldenv = getenv("LD_LIBRARY_PATH")) 
  	 && (ldenv = strdup(ldenv))) {
  		ldlist[n] = strtok(ldenv, ":");
  		while (ldlist[n] != NULL && ++n < 63)
  			ldlist[n] = strtok(NULL, ":");
  	}
  	ldlist[n] = NULL;
  
  	if (name == NULL)
  		name = "opensc-pkcs11.so";
  
  	for (dir = ldlist; *dir; dir++) {
  		snprintf(pathbuf, sizeof(pathbuf), "%s/%s", *dir, name);
  		mod->_dl_handle = dlopen(pathbuf, RTLD_NOW);
  		if (mod->_dl_handle != NULL)
  			break;
  	}
  
  	if (mod->_dl_handle == NULL)
  		mod->_dl_handle = dlopen(name, RTLD_NOW);
  
  	if (ldenv)
  		free(ldenv);
  
  	return (mod->_dl_handle? 0 : -1);
  }
  
  int
  sys_dlclose(struct sc_pkcs11_module *mod)
  {
  	if (mod->_dl_handle)
  		dlclose(mod->_dl_handle);
  	mod->_dl_handle = NULL;
  	return 0;
  }
  
  
  void *
  sys_dlsym(sc_pkcs11_module_t *mod, const char *name)
  {
  	if (!mod->_dl_handle)
  		return NULL;
  	return dlsym(mod->_dl_handle, name);
  }
  
  #endif
  
  #ifdef _WIN32
  #include <windows.h>
  
  /*
   * Module loader for the Windows platform.
   */
  int
  sys_dlopen(struct sc_pkcs11_module *mod, const char *name)
  {
  	if (name == NULL)
  		name = "opensc-pkcs11";
  
  	mod->_dl_handle = LoadLibrary(name);
  
  	return (mod->_dl_handle? 0 : GetLastError());
  }
  
  int
  sys_dlclose(struct sc_pkcs11_module *mod)
  {
  	if (mod->_dl_handle) {
  		if (FreeLibrary(mod->_dl_handle)) {
  			mod->_dl_handle = NULL;
  			return 0;
  		}
  		else
  			return -1;
  	}
  
  	return 0;
  }
  
  void *
  sys_dlsym(sc_pkcs11_module_t *mod, const char *name)
  {
  	if (!mod->_dl_handle)
  		return NULL;
  	return GetProcAddress(mod->_dl_handle, name);
  }
  
  #endif
  
  #ifdef __APPLE__
  #include <mach-o/dyld.h>
  
  /*
   * Module loader for MacOSX 10
   */
  int
  sys_dlopen(struct sc_pkcs11_module *mod, const char *name)
  {
  	int name_len;
  
  	if (name == NULL)
  		name = "libopensc-pkcs11.dylib";
  
  	name_len = strlen(name);
  	if (name_len > 7 && strcmp(name +  name_len - 7, ".bundle") != 0) {
  		mod->_dl_handle = NSAddImage(name,
  			NSADDIMAGE_OPTION_WITH_SEARCHING);
  	mod->bundleRef = NULL;
  	}
  	else {
  		CFStringRef text = CFStringCreateWithFormat(
  			NULL, NULL, CFSTR("%s"), name);
  		CFURLRef urlRef = CFURLCreateWithFileSystemPath(
  			kCFAllocatorDefault, text, kCFURLPOSIXPathStyle, 1);
  		mod->bundleRef = CFBundleCreate(kCFAllocatorDefault, urlRef);
  		CFRelease(urlRef);
  		CFRelease(text);
  		mod->_dl_handle = NULL;
  	}
  
  	return (mod->_dl_handle == NULL && mod->bundleRef == NULL ? -1 : 0);
  }
  
  int
  sys_dlclose(struct sc_pkcs11_module *mod)
  {
  	if (mod->bundleRef != NULL) {
  		CFBundleUnloadExecutable(mod->bundleRef);
  		CFRelease(mod->bundleRef);
  	}
  
  	return CKR_OK;
  }
  
  void *
  sys_dlsym(sc_pkcs11_module_t *mod, const char *name)
  {
  	NSSymbol symbol = NULL;
  	
  	if (mod->_dl_handle != NULL) {
  		char u_name[4096];
  
  		if (strlen(name) > 4094)
  			return NULL;
  		sprintf(u_name, "_%s", name);
  		symbol = NSLookupSymbolInImage(mod->_dl_handle, u_name,
  			NSLOOKUPSYMBOLINIMAGE_OPTION_BIND_NOW);
  		if (symbol==NULL)
  			return NULL;
  		return NSAddressOfSymbol(symbol);
  	}
  	else {
  		CFStringRef text = CFStringCreateWithFormat(
  			NULL, NULL, CFSTR("%s"), name);
  		symbol = CFBundleGetFunctionPointerForName(
  			mod->bundleRef, text);
  		CFRelease(text);
  		return symbol;
  	}
  }
  #endif
  