XML Security Library initialization/shutdown process includes initialization and shutdown of the dependent libraries:
libxml library;
libxslt library;
crypto library (OpenSSL, GnuTLS, GCrypt, NSS, ...);
xmlsec library (xmlSecInit and xmlSecShutdown functions);
xmlsec-crypto library (xmlSecCryptoDLLoadLibrary to load xmlsec-crypto library dynamicaly if needed, xmlSecCryptoInit and xmlSecCryptoShutdown functions);
xmlsec-crypto library also provides a convinient functions xmlSecAppCryptoInit and xmlSecAppCryptoShutdown to initialize the crypto library itself but application can do it by itself.
Example 8. Initializing application.
/* Init libxml and libxslt libraries */
xmlInitParser();
LIBXML_TEST_VERSION
xmlLoadExtDtdDefaultValue = XML_DETECT_IDS | XML_COMPLETE_ATTRS;
xmlSubstituteEntitiesDefault(1);
#ifndef XMLSEC_NO_XSLT
xmlIndentTreeOutput = 1;
#endif /* XMLSEC_NO_XSLT */
/* Init xmlsec library */
if(xmlSecInit() < 0) {
fprintf(stderr, "Error: xmlsec initialization failed.\n");
return(-1);
}
/* Check loaded library version */
if(xmlSecCheckVersion() != 1) {
fprintf(stderr, "Error: loaded xmlsec library version is not compatible.\n");
return(-1);
}
/* Load default crypto engine if we are supporting dynamic
* loading for xmlsec-crypto libraries. Use the crypto library
* name ("openssl", "nss", etc.) to load corresponding
* xmlsec-crypto library.
*/
#ifdef XMLSEC_CRYPTO_DYNAMIC_LOADING
if(xmlSecCryptoDLLoadLibrary(NULL) < 0) {
fprintf(stderr, "Error: unable to load default xmlsec-crypto library. Make sure\n"
"that you have it installed and check shared libraries path\n"
"(LD_LIBRARY_PATH) envornment variable.\n");
return(-1);
}
#endif /* XMLSEC_CRYPTO_DYNAMIC_LOADING */
/* Init crypto library */
if(xmlSecCryptoAppInit(NULL) < 0) {
fprintf(stderr, "Error: crypto initialization failed.\n");
return(-1);
}
/* Init xmlsec-crypto library */
if(xmlSecCryptoInit() < 0) {
fprintf(stderr, "Error: xmlsec-crypto initialization failed.\n");
return(-1);
}
Example 9. Shutting down application.
/* Shutdown xmlsec-crypto library */
xmlSecCryptoShutdown();
/* Shutdown crypto library */
xmlSecCryptoAppShutdown();
/* Shutdown xmlsec library */
xmlSecShutdown();
/* Shutdown libxslt/libxml */
#ifndef XMLSEC_NO_XSLT
xsltCleanupGlobals();
#endif /* XMLSEC_NO_XSLT */
xmlCleanupParser();