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diff --git a/docs/api/xmlsec-notes-contexts.html b/docs/api/xmlsec-notes-contexts.html new file mode 100644 index 00000000..247f83f6 --- /dev/null +++ b/docs/api/xmlsec-notes-contexts.html @@ -0,0 +1,229 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Using context objects.</title> +<meta name="GENERATOR" content="Modular DocBook HTML Stylesheet Version 1.79"> +<link rel="HOME" title="XML Security Library Reference Manual" href="index.html"> +<link rel="UP" title="XML Security Library Tutorial" href="xmlsec-notes.html"> +<link rel="PREVIOUS" title="Transforms and transforms chain." href="xmlsec-notes-transforms.html"> +<link rel="NEXT" title="Adding support for new cryptographic library." href="xmlsec-notes-new-crypto.html"> +<style type="text/css">.synopsis, .classsynopsis { + background: #eeeeee; + border: solid 1px #aaaaaa; + padding: 0.5em; +} +.programlisting { + background: #eeeeff; + border: solid 1px #aaaaff; + padding: 0.5em; +} +.variablelist { + padding: 4px; + margin-left: 3em; +} +.navigation { + background: #ffeeee; + border: solid 1px #ffaaaa; + margin-top: 0.5em; + margin-bottom: 0.5em; +} +.navigation a { + color: #770000; +} +.navigation a:visited { + color: #550000; +} +.navigation .title { + font-size: 200%; +}</style> +</head> +<body><table witdh="100%" valign="top"><tr valign="top"> +<td valign="top" align="left" width="210"> +<img src="../images/logo.gif" alt="XML Security Library" border="0"><p></p> +<ul> +<li><a href="../index.html">Home</a></li> +<li><a href="../download.html">Download</a></li> +<li><a href="../news.html">News</a></li> +<li><a href="../documentation.html">Documentation</a></li> +<ul> +<li><a href="../faq.html">FAQ</a></li> +<li><a href="../api/xmlsec-notes.html">Tutorial</a></li> +<li><a href="../api/xmlsec-reference.html">API reference</a></li> +<li><a href="../api/xmlsec-examples.html">Examples</a></li> +</ul> +<li><a href="../xmldsig.html">XML Digital Signature</a></li> +<ul><li><a href="http://www.aleksey.com/xmlsec/xmldsig-verifier.html">Online Verifier</a></li></ul> +<li><a href="../xmlenc.html">XML Encryption</a></li> +<li><a href="../c14n.html">XML Canonicalization</a></li> +<li><a href="../bugs.html">Reporting Bugs</a></li> +<li><a href="http://www.aleksey.com/pipermail/xmlsec">Mailing list</a></li> +<li><a href="../related.html">Related</a></li> +<li><a href="../authors.html">Authors</a></li> +</ul> +<table width="100%"> +<tr> +<td width="15"></td> +<td><a href="http://xmlsoft.org/"><img src="../images/libxml2-logo.png" alt="LibXML2" border="0"></a></td> +</tr> +<tr> +<td width="15"></td> +<td><a href="http://xmlsoft.org/XSLT"><img src="../images/libxslt-logo.png" alt="LibXSLT" border="0"></a></td> +</tr> +<tr> +<td width="15"></td> +<td><a href="http://www.openssl.org/"><img src="../images/openssl-logo.png" alt="OpenSSL" border="0"></a></td> +</tr> +<!--Links - start--><!--Links - end--> +</table> +</td> +<td valign="top"><table width="100%" valign="top"><tr><td valign="top" align="left" id="xmlsecContent"> +<table width="100%" class="navigation" summary="Navigation header" cellpadding="2" cellspacing="2"><tr valign="middle"> +<td><a accesskey="p" href="xmlsec-notes-transforms.html"><img src="left.png" width="24" height="24" border="0" alt="Prev"></a></td> +<td><a accesskey="u" href="xmlsec-notes.html"><img src="up.png" width="24" height="24" border="0" alt="Up"></a></td> +<td><a accesskey="h" href="index.html"><img src="home.png" width="24" height="24" border="0" alt="Home"></a></td> +<th width="100%" align="center">XML Security Library Reference Manual</th> +<td><a accesskey="n" href="xmlsec-notes-new-crypto.html"><img src="right.png" width="24" height="24" border="0" alt="Next"></a></td> +</tr></table> +<div class="CHAPTER"> +<h1> +<a name="XMLSEC-NOTES-CONTEXTS"></a>Using context objects.</h1> +<p>The great flexibility of XML Digital Signature and XML Encryption + specification is one of the most interesting and in the same time, + most dangerouse feature for an application developer. + For example, XPath and XSLT transform can make it very difficult + to find out what exactly was signed by just looking at the + transforms and the input data. Many protocols based on + XML Digital Signature and XML Encryption restrict allowed + key data types, allowed transforms or possible input data. + For example, signature in a simple SAML Response should have only + one <dsig:Reference/> element with an empty or NULL + URI attribute and only one enveloped transform. + XML Security Library uses "context" objects to let application + enable or disable particular features, return the result + data and the information collected during the processing. + Also all the context objects defined in XML Security library have + a special <code class="STRUCTFIELD">userData</code> member which could + be used by application to pass application specific data around. + XML Security Library never use this field. + The application creates a new + <a href="xmlsec-xmldsig.html#XMLSECDSIGCTX">xmlSecDSigCtx</a> + or <a href="xmlsec-xmlenc.html#XMLSECENCCTX">xmlSecEncCtx</a> object for each + operation, sets necessary options and consumes result returned + in the context after signature, verification, encryption or decryption. + </p> +<p> </p> +<div class="EXAMPLE"> +<a name="AEN489"></a><p><b>Example 1. SAML signature validation.</b></p> +<pre class="PROGRAMLISTING">/** + * verify_file: + * @mngr: the pointer to keys manager. + * @xml_file: the signed XML file name. + * + * Verifies XML signature in #xml_file. + * + * Returns 0 on success or a negative value if an error occurs. + */ +int +verify_file(xmlSecKeysMngrPtr mngr, const char* xml_file) { + xmlDocPtr doc = NULL; + xmlNodePtr node = NULL; + xmlSecDSigCtxPtr dsigCtx = NULL; + int res = -1; + + assert(mngr); + assert(xml_file); + + /* load file */ + doc = xmlParseFile(xml_file); + if ((doc == NULL) || (xmlDocGetRootElement(doc) == NULL)){ + fprintf(stderr, "Error: unable to parse file \"%s\"\n", xml_file); + goto done; + } + + /* find start node */ + node = xmlSecFindNode(xmlDocGetRootElement(doc), xmlSecNodeSignature, xmlSecDSigNs); + if(node == NULL) { + fprintf(stderr, "Error: start node not found in \"%s\"\n", xml_file); + goto done; + } + + /* create signature context */ + dsigCtx = xmlSecDSigCtxCreate(mngr); + if(dsigCtx == NULL) { + fprintf(stderr,"Error: failed to create signature context\n"); + goto done; + } + + /* limit the Reference URI attributes to empty or NULL */ + dsigCtx->enabledReferenceUris = xmlSecTransformUriTypeEmpty; + + /* limit allowed transforms for siganture and reference processing */ + if((xmlSecDSigCtxEnableSignatureTransform(dsigCtx, xmlSecTransformInclC14NId) < 0) || + (xmlSecDSigCtxEnableSignatureTransform(dsigCtx, xmlSecTransformExclC14NId) < 0) || + (xmlSecDSigCtxEnableSignatureTransform(dsigCtx, xmlSecTransformSha1Id) < 0) || + (xmlSecDSigCtxEnableSignatureTransform(dsigCtx, xmlSecTransformRsaSha1Id) < 0)) { + + fprintf(stderr,"Error: failed to limit allowed siganture transforms\n"); + goto done; + } + if((xmlSecDSigCtxEnableReferenceTransform(dsigCtx, xmlSecTransformInclC14NId) < 0) || + (xmlSecDSigCtxEnableReferenceTransform(dsigCtx, xmlSecTransformExclC14NId) < 0) || + (xmlSecDSigCtxEnableReferenceTransform(dsigCtx, xmlSecTransformSha1Id) < 0) || + (xmlSecDSigCtxEnableReferenceTransform(dsigCtx, xmlSecTransformEnvelopedId) < 0)) { + + fprintf(stderr,"Error: failed to limit allowed reference transforms\n"); + goto done; + } + + /* in addition, limit possible key data to valid X509 certificates only */ + if(xmlSecPtrListAdd(&(dsigCtx->keyInfoReadCtx.enabledKeyData), BAD_CAST xmlSecKeyDataX509Id) < 0) { + fprintf(stderr,"Error: failed to limit allowed key data\n"); + goto done; + } + + /* Verify signature */ + if(xmlSecDSigCtxVerify(dsigCtx, node) < 0) { + fprintf(stderr,"Error: signature verify\n"); + goto done; + } + + /* check that we have only one Reference */ + if((dsigCtx->status == xmlSecDSigStatusSucceeded) && + (xmlSecPtrListGetSize(&(dsigCtx->signedInfoReferences)) != 1)) { + + fprintf(stderr,"Error: only one reference is allowed\n"); + goto done; + } + + /* print verification result to stdout */ + if(dsigCtx->status == xmlSecDSigStatusSucceeded) { + fprintf(stdout, "Signature is OK\n"); + } else { + fprintf(stdout, "Signature is INVALID\n"); + } + + /* success */ + res = 0; + +done: + /* cleanup */ + if(dsigCtx != NULL) { + xmlSecDSigCtxDestroy(dsigCtx); + } + + if(doc != NULL) { + xmlFreeDoc(doc); + } + return(res); +} + + </pre> +</div> + </div> +<table class="navigation" width="100%" summary="Navigation footer" cellpadding="2" cellspacing="2"><tr valign="middle"> +<td align="left"><a accesskey="p" href="xmlsec-notes-transforms.html"><b><<< Transforms and transforms chain.</b></a></td> +<td align="right"><a accesskey="n" href="xmlsec-notes-new-crypto.html"><b>Adding support for new cryptographic library. >>></b></a></td> +</tr></table> +</td></tr></table></td> +</tr></table></body> +</html> |