Sophie: xmlsec1-devel-1.2.16-3.fc14 x86

xmlsec1-devel-1.2.16-3.fc14.x86_64.rpm

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<br clear="all"><div class="SECT1">
<h1 class="SECT1"><a name="XMLSEC-NOTES-DECRYPT">Decrypting an encrypted document</a></h1>
<p>The typical decryption process includes following steps:
	  </p>
<p></p>
<ul>
<li><p>		Load keys, X509 certificates, etc. in the <a href="xmlsec-keysmngr.html#XMLSECKEYSMNGR">keys manager</a> .
	    </p></li>
<li><p>		Create encryption context <a href="xmlsec-xmlenc.html#XMLSECENCCTX">xmlSecEncCtx</a>
		using <a href="xmlsec-xmlenc.html#XMLSECENCCTXCREATE">xmlSecEncCtxCreate</a> or
		<a href="xmlsec-xmlenc.html#XMLSECENCCTXINITIALIZE">xmlSecEncCtxInitialize</a>
		functions.
	    </p></li>
<li><p>		Select start decryption &lt;enc:EncryptedData&gt; node.
	    </p></li>
<li><p>		Decrypt by calling <a href="xmlsec-xmlenc.html#XMLSECENCCTXDECRYPT">xmlSecencCtxDecrypt</a> 
		function.
	    </p></li>
<li><p>		Check returned value and if necessary consume encrypted data.
	    </p></li>
<li><p>		Destroy encryption context <a href="xmlsec-xmlenc.html#XMLSECENCCTX">xmlSecEncCtx</a>
		using <a href="xmlsec-xmlenc.html#XMLSECENCCTXDESTROY">xmlSecEncCtxDestroy</a> or
		<a href="xmlsec-xmlenc.html#XMLSECENCCTXFINALIZE">xmlSecEncCtxFinalize</a>
		functions.
	    </p></li>
</ul>
<p>	     </p>
<div class="EXAMPLE">
<a name="AEN333"></a><p><b>Example 2. Decrypting a document.</b></p>
<pre class="PROGRAMLISTING">int 
decrypt_file(const char* enc_file, const char* key_file) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    xmlSecEncCtxPtr encCtx = NULL;
    int res = -1;
    
    assert(enc_file);
    assert(key_file);

    /* load template */
    doc = xmlParseFile(enc_file);
    if ((doc == NULL) || (xmlDocGetRootElement(doc) == NULL)){
	fprintf(stderr, "Error: unable to parse file \"%s\"\n", enc_file);
	goto done;	
    }
    
    /* find start node */
    node = xmlSecFindNode(xmlDocGetRootElement(doc), xmlSecNodeEncryptedData, xmlSecEncNs);
    if(node == NULL) {
	fprintf(stderr, "Error: start node not found in \"%s\"\n", enc_file);
	goto done;	
    }

    /* create encryption context, we don't need keys manager in this example */
    encCtx = xmlSecEncCtxCreate(NULL);
    if(encCtx == NULL) {
        fprintf(stderr,"Error: failed to create encryption context\n");
	goto done;
    }

    /* load DES key */
    encCtx-&gt;encKey = xmlSecKeyReadBinaryFile(xmlSecKeyDataDesId, key_file);
    if(encCtx-&gt;encKey == NULL) {
        fprintf(stderr,"Error: failed to load des key from binary file \"%s\"\n", key_file);
	goto done;
    }

    /* set key name to the file name, this is just an example! */
    if(xmlSecKeySetName(encCtx-&gt;encKey, key_file) &lt; 0) {
    	fprintf(stderr,"Error: failed to set key name for key from \"%s\"\n", key_file);
	goto done;
    }

    /* decrypt the data */
    if((xmlSecEncCtxDecrypt(encCtx, node) &lt; 0) || (encCtx-&gt;result == NULL)) {
        fprintf(stderr,"Error: decryption failed\n");
	goto done;
    }
        
    /* print decrypted data to stdout */
    if(encCtx-&gt;resultReplaced != 0) {
	fprintf(stdout, "Decrypted XML data:\n");
	xmlDocDump(stdout, doc);
    } else {
	fprintf(stdout, "Decrypted binary data (%d bytes):\n", xmlSecBufferGetSize(encCtx-&gt;result));
	if(xmlSecBufferGetData(encCtx-&gt;result) != NULL) {
	    fwrite(xmlSecBufferGetData(encCtx-&gt;result), 
	          1, 
	          xmlSecBufferGetSize(encCtx-&gt;result),
	          stdout);
	}
    }
    fprintf(stdout, "\n");
        
    /* success */
    res = 0;

done:    
    /* cleanup */
    if(encCtx != NULL) {
	xmlSecEncCtxDestroy(encCtx);
    }
    
    if(doc != NULL) {
	xmlFreeDoc(doc); 
    }
    return(res);
}
		</pre>
<p><a href="xmlsec-decrypt-with-signle-key.html#XMLSEC-EXAMPLE-DECRYPT1">Full Program Listing</a></p>
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