docs/api/chapters/init-and-shutdown.sgml

   1 <chapter id="xmlsec-notes-init-shutdown">
   2     <title>Initialization and shutdown.</title>
   3     <para>XML Security Library initialization/shutdown
   4         process includes initialization and shutdown of the
   5         dependent libraries:
   6         <itemizedlist>
   7             <listitem><para>libxml library;</para></listitem>
   8             <listitem><para>libxslt library;</para></listitem>
   9             <listitem><para>crypto library (OpenSSL, GnuTLS, NSS, ...);</para></listitem>
  10             <listitem><para>xmlsec library
  11                 (<link linkend="xmlSecInit">xmlSecInit</link>
  12                 and <link linkend="xmlSecShutdown">xmlSecShutdown</link>
  13                 functions);
  14             </para></listitem>
  15             <listitem><para>xmlsec-crypto library
  16                 (<link linkend="xmlSecCryptoDLLoadLibrary">xmlSecCryptoDLLoadLibrary</link>
  17                 to load xmlsec-crypto library dynamicaly if needed,
  18                 <link linkend="xmlSecCryptoInit">xmlSecCryptoInit</link>
  19                 and <link linkend="xmlSecCryptoShutdown">xmlSecCryptoShutdown</link>
  20                 functions);
  21             </para></listitem>
  22         </itemizedlist>
  23         xmlsec-crypto library also provides a convinient functions
  24         <link linkend="xmlSecAppCryptoInit">xmlSecAppCryptoInit</link>
  25         and <link linkend="xmlSecAppCryptoShutdown">xmlSecAppCryptoShutdown</link>
  26         to initialize the crypto library itself but application can do it
  27         by itself.
  28         </para>
  29         <para>
  30              <example>
  31                 <title>Initializing application.</title>
  32                 <programlisting><![CDATA[
  33     /* Init libxml and libxslt libraries */
  34     xmlInitParser();
  35     LIBXML_TEST_VERSION
  36     xmlLoadExtDtdDefaultValue = XML_DETECT_IDS | XML_COMPLETE_ATTRS;
  37     xmlSubstituteEntitiesDefault(1);
  38 #ifndef XMLSEC_NO_XSLT
  39     xmlIndentTreeOutput = 1;
  40 #endif /* XMLSEC_NO_XSLT */
  41
  42     /* Init xmlsec library */
  43     if(xmlSecInit() < 0) {
  44         fprintf(stderr, "Error: xmlsec initialization failed.\n");
  45         return(-1);
  46     }
  47
  48     /* Check loaded library version */
  49     if(xmlSecCheckVersion() != 1) {
  50         fprintf(stderr, "Error: loaded xmlsec library version is not compatible.\n");
  51         return(-1);
  52     }
  53
  54     /* Load default crypto engine if we are supporting dynamic
  55      * loading for xmlsec-crypto libraries. Use the crypto library
  56      * name ("openssl", "nss", etc.) to load corresponding
  57      * xmlsec-crypto library.
  58      */
  59 #ifdef XMLSEC_CRYPTO_DYNAMIC_LOADING
  60     if(xmlSecCryptoDLLoadLibrary(BAD_CAST XMLSEC_CRYPTO) < 0) {
  61         fprintf(stderr, "Error: unable to load default xmlsec-crypto library. Make sure\n"
  62                         "that you have it installed and check shared libraries path\n"
  63                         "(LD_LIBRARY_PATH) envornment variable.\n");
  64         return(-1);
  65     }
  66 #endif /* XMLSEC_CRYPTO_DYNAMIC_LOADING */
  67
  68     /* Init crypto library */
  69     if(xmlSecCryptoAppInit(NULL) < 0) {
  70         fprintf(stderr, "Error: crypto initialization failed.\n");
  71         return(-1);
  72     }
  73
  74     /* Init xmlsec-crypto library */
  75     if(xmlSecCryptoInit() < 0) {
  76         fprintf(stderr, "Error: xmlsec-crypto initialization failed.\n");
  77         return(-1);
  78     }
  79                 ]]></programlisting>
  80             </example>
  81         </para>
  82
  83         <para>
  84              <example>
  85                 <title>Shutting down application.</title>
  86                 <programlisting><![CDATA[
  87     /* Shutdown xmlsec-crypto library */
  88     xmlSecCryptoShutdown();
  89
  90     /* Shutdown crypto library */
  91     xmlSecCryptoAppShutdown();
  92
  93     /* Shutdown xmlsec library */
  94     xmlSecShutdown();
  95
  96     /* Shutdown libxslt/libxml */
  97 #ifndef XMLSEC_NO_XSLT
  98     xsltCleanupGlobals();
  99 #endif /* XMLSEC_NO_XSLT */
 100     xmlCleanupParser();
 101                 ]]></programlisting>
 102             </example>
 103     </para>
 104 </chapter>