src/templates.c - master - githubmirror/xmlsec

src/templates.c
1 817 строк62 KB
Javid Khan
free node on xmlSetProp failure in xmlSecTmplX509DataAddDigest (#1189)
29 май 2026, 19:47
29 май 2026, 19:4706454c5
/**
 * XML Security Library (http://www.aleksey.com/xmlsec).
 *
 * This is free software; see the Copyright file in the source distribution for precise wording.
 *
 * Copyright (C) 2002-2026 Aleksey Sanin <aleksey@aleksey.com>. All Rights Reserved.
 */
/**
 * @addtogroup xmlsec_core_templates
 * @brief XML signature and encryption template functions.
 */
#include "globals.h"

#include <stdlib.h>
#include <string.h>

#include <libxml/tree.h>

#include <xmlsec/xmlsec.h>
#include <xmlsec/xmltree.h>
#include <xmlsec/transforms.h>
#include <xmlsec/strings.h>
#include <xmlsec/base64.h>
#include <xmlsec/templates.h>
#include <xmlsec/parser.h>
#include <xmlsec/errors.h>


static xmlNodePtr       xmlSecTmplAddReference          (xmlNodePtr parentNode,
                                                         xmlSecTransformId digestMethodId,
                                                         const xmlChar *id,
                                                         const xmlChar *uri,
                                                         const xmlChar *type);
static int              xmlSecTmplPrepareEncData        (xmlNodePtr parentNode,
                                                         xmlSecTransformId encMethodId);
static int              xmlSecTmplNodeWriteNsList       (xmlNodePtr parentNode,
                                                         const xmlChar** namespaces);
/******************************************************************************
 *
 * &lt;dsig:Signature/&gt; node
 *
  *****************************************************************************/
/**
 * @brief Creates a new &lt;dsig:Signature/&gt; node with required children.
 * @details Creates new &lt;dsig:Signature/&gt; node with the mandatory &lt;dsig:SignedInfo/&gt;,
 * &lt;dsig:CanonicalizationMethod/&gt;, &lt;dsig:SignatureMethod/&gt; and
 * &lt;dsig:SignatureValue/&gt; children and sub-children.
 * The application is responsible for inserting the returned node
 * in the XML document.
 * @param doc the pointer to signature document or NULL; in the
 *                      second case, application must later call xmlSetTreeDoc
 *                      to ensure that all the children nodes have correct
 *                      pointer to XML document.
 * @param c14nMethodId the signature canonicalization method.
 * @param signMethodId the signature  method.
 * @param id the node id (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:Signature/&gt; node or NULL if an
 * error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureCreate(xmlDocPtr doc, xmlSecTransformId c14nMethodId,
                      xmlSecTransformId signMethodId, const xmlChar *id) {
    return xmlSecTmplSignatureCreateNsPref(doc, c14nMethodId, signMethodId, id, NULL);
}

/**
 * @brief Creates a new &lt;dsig:Signature/&gt; node with a custom namespace prefix.
 * @details Creates new &lt;dsig:Signature/&gt; node with the mandatory
 * &lt;dsig:SignedInfo/&gt;, &lt;dsig:CanonicalizationMethod/&gt;,
 * &lt;dsig:SignatureMethod/&gt; and &lt;dsig:SignatureValue/&gt; children and
 * sub-children. This method differs from xmlSecTmplSignatureCreate in
 * that it will define the http://www.w3.org/2000/09/xmldsig#
 * namespace with the given prefix that will be used for all of the
 * appropriate child nodes.  The application is responsible for
 * inserting the returned node in the XML document.
 * @param doc the pointer to signature document or NULL; in the
 *                      second case, application must later call xmlSetTreeDoc
 *                      to ensure that all the children nodes have correct
 *                      pointer to XML document.
 * @param c14nMethodId the signature canonicalization method.
 * @param signMethodId the signature  method.
 * @param id the node id (may be NULL).
 * @param nsPrefix the namespace prefix for the signature element (e.g. "dsig"), or NULL
 *
 * @return the pointer to newly created &lt;dsig:Signature/&gt; node or NULL if an
 * error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureCreateNsPref(xmlDocPtr doc, xmlSecTransformId c14nMethodId,
                                xmlSecTransformId signMethodId, const xmlChar *id,
                                const xmlChar* nsPrefix) {
    xmlNodePtr signNode;
    xmlNodePtr signedInfoNode;
    xmlNodePtr cur;
    xmlNsPtr ns;

    xmlSecAssert2(c14nMethodId != NULL, NULL);
    xmlSecAssert2(c14nMethodId->href != NULL, NULL);
    xmlSecAssert2(signMethodId != NULL, NULL);
    xmlSecAssert2(signMethodId->href != NULL, NULL);

    /* create Signature node itself */
    signNode = xmlNewDocNode(doc, NULL, xmlSecNodeSignature, NULL);
    if(signNode == NULL) {
        xmlSecXmlError2("xmlNewDocNode", NULL,
                        "node=%s", xmlSecErrorsSafeString(xmlSecNodeSignature));
        return(NULL);
    }

    ns = xmlNewNs(signNode, xmlSecDSigNs, nsPrefix);
    if(ns == NULL) {
        xmlSecXmlError2("xmlNewNs", NULL,
                        "ns=%s", xmlSecErrorsSafeString(xmlSecDSigNs));
        xmlFreeNode(signNode);
        return(NULL);
    }
    xmlSetNs(signNode, ns);

    if(id != NULL) {
        xmlSetProp(signNode, BAD_CAST "Id", id);
    }

    /* add SignedInfo node */
    signedInfoNode = xmlSecAddChild(signNode, xmlSecNodeSignedInfo, xmlSecDSigNs);
    if(signedInfoNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeSignedInfo)", NULL);
        xmlFreeNode(signNode);
        return(NULL);
    }

    /* add SignatureValue node */
    cur = xmlSecAddChild(signNode, xmlSecNodeSignatureValue, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeSignatureValue)", NULL);
        xmlFreeNode(signNode);
        return(NULL);
    }

    /* add CanonicalizationMethod node to SignedInfo */
    cur = xmlSecAddChild(signedInfoNode, xmlSecNodeCanonicalizationMethod, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeCanonicalizationMethod)", NULL);
        xmlFreeNode(signNode);
        return(NULL);
    }
    if(xmlSetProp(cur, xmlSecAttrAlgorithm, c14nMethodId->href) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlFreeNode(signNode);
        return(NULL);
    }

    /* add SignatureMethod node to SignedInfo */
    cur = xmlSecAddChild(signedInfoNode, xmlSecNodeSignatureMethod, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeSignatureMethod)", NULL);
        xmlFreeNode(signNode);
        return(NULL);
    }
    if(xmlSetProp(cur, xmlSecAttrAlgorithm, signMethodId->href) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlFreeNode(signNode);
        return(NULL);
    }

    return(signNode);
}

/**
 * @brief Ensures a &lt;dsig:KeyInfo/&gt; child node in the &lt;dsig:Signature/&gt; node.
 * @details Adds (if necessary) &lt;dsig:KeyInfo/&gt; node to the &lt;dsig:Signature/&gt;
 * node @p signNode.
 * @param signNode the  pointer to &lt;dsig:Signature/&gt; node.
 * @param id the node id (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:KeyInfo/&gt; node or NULL if an
 * error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureEnsureKeyInfo(xmlNodePtr signNode, const xmlChar *id) {
    xmlNodePtr res;

    xmlSecAssert2(signNode != NULL, NULL);

    res = xmlSecFindChild(signNode, xmlSecNodeKeyInfo, xmlSecDSigNs);
    if(res == NULL) {
        xmlNodePtr signValueNode;

        signValueNode = xmlSecFindChild(signNode, xmlSecNodeSignatureValue, xmlSecDSigNs);
        if(signValueNode == NULL) {
            xmlSecNodeNotFoundError("xmlSecFindChild", signNode,
                                    xmlSecNodeSignatureValue, NULL);
            return(NULL);
        }

        res = xmlSecAddNextSibling(signValueNode, xmlSecNodeKeyInfo, xmlSecDSigNs);
        if(res == NULL) {
            xmlSecInternalError("xmlSecAddNextSibling(xmlSecNodeKeyInfo)", NULL);
            return(NULL);
        }
    }
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:Reference/&gt; node to the &lt;dsig:SignedInfo/&gt; child.
 * @details Adds &lt;dsig:Reference/&gt; node with given URI (@p uri), Id (@p id) and
 * Type (@p type) attributes and the required children &lt;dsig:DigestMethod/&gt; and
 * &lt;dsig:DigestValue/&gt; to the &lt;dsig:SignedInfo/&gt; child of @p signNode.
 * @param signNode the pointer to &lt;dsig:Signature/&gt; node.
 * @param digestMethodId the reference digest method.
 * @param id the node id (may be NULL).
 * @param uri the reference node uri (may be NULL).
 * @param type the reference node type (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:Reference/&gt; node or NULL
 * if an error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureAddReference(xmlNodePtr signNode, xmlSecTransformId digestMethodId,
                    const xmlChar *id, const xmlChar *uri, const xmlChar *type) {
    xmlNodePtr signedInfoNode;

    xmlSecAssert2(signNode != NULL, NULL);
    xmlSecAssert2(digestMethodId != NULL, NULL);
    xmlSecAssert2(digestMethodId->href != NULL, NULL);

    signedInfoNode = xmlSecFindChild(signNode, xmlSecNodeSignedInfo, xmlSecDSigNs);
    if(signedInfoNode == NULL) {
        xmlSecNodeNotFoundError("xmlSecFindChild", signNode,
                                xmlSecNodeSignedInfo, NULL);
        return(NULL);
    }

    return(xmlSecTmplAddReference(signedInfoNode, digestMethodId, id, uri, type));
}

static xmlNodePtr
xmlSecTmplAddReference(xmlNodePtr parentNode, xmlSecTransformId digestMethodId,
                    const xmlChar *id, const xmlChar *uri, const xmlChar *type) {
    xmlNodePtr res;
    xmlNodePtr cur;

    xmlSecAssert2(parentNode != NULL, NULL);
    xmlSecAssert2(digestMethodId != NULL, NULL);
    xmlSecAssert2(digestMethodId->href != NULL, NULL);

    /* add Reference node */
    res = xmlSecAddChild(parentNode, xmlSecNodeReference, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeReference)", NULL);
        return(NULL);
    }

    /* set Reference node attributes */
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    if(type != NULL) {
        xmlSetProp(res, xmlSecAttrType, type);
    }
    if(uri != NULL) {
        xmlSetProp(res, xmlSecAttrURI, uri);
    }

    /* add DigestMethod node and set algorithm */
    cur = xmlSecAddChild(res, xmlSecNodeDigestMethod, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeDigestMethod)", NULL);
        xmlUnlinkNode(res);
        xmlFreeNode(res);
        return(NULL);
    }
    if(xmlSetProp(cur, xmlSecAttrAlgorithm, digestMethodId->href) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(res);
        xmlFreeNode(res);
        return(NULL);
    }

    /* add DigestValue node */
    cur = xmlSecAddChild(res, xmlSecNodeDigestValue, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeDigestValue)", NULL);
        xmlUnlinkNode(res);
        xmlFreeNode(res);
        return(NULL);
    }

    return(res);
}

/**
 * @brief Adds a &lt;dsig:Object/&gt; node to the &lt;dsig:Signature/&gt; node.
 * @details Adds &lt;dsig:Object/&gt; node to the &lt;dsig:Signature/&gt; node @p signNode.
 * @param signNode the pointer to &lt;dsig:Signature/&gt; node.
 * @param id the node id (may be NULL).
 * @param mimeType the object mime type (may be NULL).
 * @param encoding the object encoding (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:Object/&gt; node or NULL
 * if an error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureAddObject(xmlNodePtr signNode, const xmlChar *id,
                         const xmlChar *mimeType, const xmlChar *encoding) {
    xmlNodePtr res;

    xmlSecAssert2(signNode != NULL, NULL);

    res = xmlSecAddChild(signNode, xmlSecNodeObject, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeObject)", NULL);
        return(NULL);
    }
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    if(mimeType != NULL) {
        xmlSetProp(res, xmlSecAttrMimeType, mimeType);
    }
    if(encoding != NULL) {
        xmlSetProp(res, xmlSecAttrEncoding, encoding);
    }
    return(res);
}

/**
 * @brief Gets the &lt;dsig:SignatureMethod/&gt; child of &lt;dsig:KeyInfo/&gt; node.
 * @details Gets pointer to &lt;dsig:SignatureMethod/&gt; child of &lt;dsig:KeyInfo/&gt; node.
 * @param signNode the pointer to <dsig:Signature /> node.
 *
 * @return pointer to <dsig:SignatureMethod /> node or NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureGetSignMethodNode(xmlNodePtr signNode) {
    xmlNodePtr signedInfoNode;

    xmlSecAssert2(signNode != NULL, NULL);

    signedInfoNode = xmlSecFindChild(signNode, xmlSecNodeSignedInfo, xmlSecDSigNs);
    if(signedInfoNode == NULL) {
        xmlSecNodeNotFoundError("xmlSecFindChild", signNode,
                                xmlSecNodeSignedInfo, NULL);
        return(NULL);
    }
    return(xmlSecFindChild(signedInfoNode, xmlSecNodeSignatureMethod, xmlSecDSigNs));
}

/**
 * @brief Gets the &lt;dsig:CanonicalizationMethod/&gt; child of &lt;dsig:KeyInfo/&gt; node.
 * @details Gets pointer to &lt;dsig:CanonicalizationMethod/&gt; child of &lt;dsig:KeyInfo/&gt; node.
 * @param signNode the pointer to <dsig:Signature /> node.
 *
 * @return pointer to <dsig:CanonicalizationMethod /> node or NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplSignatureGetC14NMethodNode(xmlNodePtr signNode) {
    xmlNodePtr signedInfoNode;

    xmlSecAssert2(signNode != NULL, NULL);

    signedInfoNode = xmlSecFindChild(signNode, xmlSecNodeSignedInfo, xmlSecDSigNs);
    if(signedInfoNode == NULL) {
        xmlSecNodeNotFoundError("xmlSecFindChild", signNode,
                                xmlSecNodeSignedInfo, NULL);
        return(NULL);
    }
    return(xmlSecFindChild(signedInfoNode, xmlSecNodeCanonicalizationMethod, xmlSecDSigNs));
}

/**
 * @brief Adds a &lt;dsig:Transform/&gt; node to the &lt;dsig:Reference/&gt; node.
 * @details Adds &lt;dsig:Transform/&gt; node to the &lt;dsig:Reference/&gt; node @p referenceNode.
 * @param referenceNode the pointer to &lt;dsig:Reference/&gt; node.
 * @param transformId the transform method id.
 *
 * @return the pointer to newly created &lt;dsig:Transform/&gt; node or NULL if an
 * error occurs.
 */
xmlNodePtr
xmlSecTmplReferenceAddTransform(xmlNodePtr referenceNode, xmlSecTransformId transformId) {
    xmlNodePtr transformsNode;
    xmlNodePtr res;

    xmlSecAssert2(referenceNode != NULL, NULL);
    xmlSecAssert2(transformId != NULL, NULL);
    xmlSecAssert2(transformId->href != NULL, NULL);

    /* do we need to create Transforms node first */
    transformsNode = xmlSecFindChild(referenceNode, xmlSecNodeTransforms, xmlSecDSigNs);
    if(transformsNode == NULL) {
        xmlNodePtr tmp;

        tmp = xmlSecGetNextElementNode(referenceNode->children);
        if(tmp == NULL) {
            transformsNode = xmlSecAddChild(referenceNode, xmlSecNodeTransforms, xmlSecDSigNs);
            if(transformsNode == NULL) {
                xmlSecInternalError("xmlSecAddChild(xmlSecNodeTransforms)", NULL);
                return(NULL);
            }
        } else {
            transformsNode = xmlSecAddPrevSibling(tmp, xmlSecNodeTransforms, xmlSecDSigNs);
            if(transformsNode == NULL) {
                xmlSecInternalError("xmlSecAddPrevSibling(xmlSecNodeTransforms)", NULL);
                return(NULL);
            }
        }
    }

    res = xmlSecAddChild(transformsNode, xmlSecNodeTransform, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeTransform)", NULL);
        return(NULL);
    }

    if(xmlSetProp(res, xmlSecAttrAlgorithm, transformId->href) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(res);
        xmlFreeNode(res);
        return(NULL);
    }

    return(res);
}

/**
 * @brief Adds a &lt;dsig:SignatureProperties/&gt; node to the &lt;dsig:Object/&gt; node.
 * @details Adds &lt;dsig:SignatureProperties/&gt; node to the &lt;dsig:Object/&gt; node @p objectNode.
 * @param objectNode the  pointer to &lt;dsig:Object/&gt; node.
 * @param id the node id (may be NULL).
 * @param target the Target  (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:SignatureProperties/&gt; node or NULL
 * if an error occurs.
 */
xmlNodePtr
xmlSecTmplObjectAddSignProperties(xmlNodePtr objectNode, const xmlChar *id, const xmlChar *target) {
    xmlNodePtr res;

    xmlSecAssert2(objectNode != NULL, NULL);

    res = xmlSecAddChild(objectNode, xmlSecNodeSignatureProperties, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeSignatureProperties)", NULL);
        return(NULL);
    }
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    if(target != NULL) {
        xmlSetProp(res, xmlSecAttrTarget, target);
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:Manifest/&gt; node to the &lt;dsig:Object/&gt; node.
 * @details Adds &lt;dsig:Manifest/&gt; node to the &lt;dsig:Object/&gt; node @p objectNode.
 * @param objectNode the  pointer to &lt;dsig:Object/&gt; node.
 * @param id the node id (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:Manifest/&gt; node or NULL
 * if an error occurs.
 */
xmlNodePtr
xmlSecTmplObjectAddManifest(xmlNodePtr objectNode,  const xmlChar *id) {
    xmlNodePtr res;

    xmlSecAssert2(objectNode != NULL, NULL);

    res = xmlSecAddChild(objectNode, xmlSecNodeManifest, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeManifest)", NULL);
        return(NULL);
    }
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:Reference/&gt; node to the &lt;dsig:Manifest/&gt; node.
 * @details Adds &lt;dsig:Reference/&gt; node with specified URI (@p uri), Id (@p id) and
 * Type (@p type) attributes and the required children &lt;dsig:DigestMethod/&gt; and
 * &lt;dsig:DigestValue/&gt; to the &lt;dsig:Manifest/&gt; node @p manifestNode.
 * @param manifestNode the pointer to &lt;dsig:Manifest/&gt; node.
 * @param digestMethodId the reference digest method.
 * @param id the node id (may be NULL).
 * @param uri the reference node uri (may be NULL).
 * @param type the reference node type (may be NULL).
 *
 * @return the pointer to newly created &lt;dsig:Reference/&gt; node or NULL
 * if an error occurs.
 */
xmlNodePtr
xmlSecTmplManifestAddReference(xmlNodePtr manifestNode, xmlSecTransformId digestMethodId,
                              const xmlChar *id, const xmlChar *uri, const xmlChar *type) {
    return(xmlSecTmplAddReference(manifestNode, digestMethodId, id, uri, type));
}

/******************************************************************************
 *
 * &lt;enc:EncryptedData/&gt; node
 *
  *****************************************************************************/
/**
 * @brief Creates a new &lt;enc:EncryptedData/&gt; node for encryption template.
 * @details Creates new <enc:EncryptedData /> node for encryption template.
 * @param doc the pointer to signature document or NULL; in the later
 *                      case, application must later call xmlSetTreeDoc to ensure
 *                      that all the children nodes have correct pointer to XML document.
 * @param encMethodId the encryption method (may be NULL).
 * @param id the Id attribute (optional).
 * @param type the Type attribute (optional)
 * @param mimeType the MimeType attribute (optional)
 * @param encoding the Encoding attribute (optional)
 *
 * @return the pointer newly created  &lt;enc:EncryptedData/&gt; node or NULL
 * if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataCreate(xmlDocPtr doc, xmlSecTransformId encMethodId,
                            const xmlChar *id, const xmlChar *type,
                            const xmlChar *mimeType, const xmlChar *encoding) {
    xmlNodePtr encNode;
    xmlNsPtr ns;

    encNode = xmlNewDocNode(doc, NULL, xmlSecNodeEncryptedData, NULL);
    if(encNode == NULL) {
        xmlSecXmlError2("xmlNewDocNode", NULL,
                        "node=%s", xmlSecErrorsSafeString(xmlSecNodeEncryptedData));
        return(NULL);
    }

    ns = xmlNewNs(encNode, xmlSecEncNs, NULL);
    if(ns == NULL) {
        xmlSecXmlError2("xmlNewNs", NULL,
                        "ns=%s", xmlSecErrorsSafeString(xmlSecEncNs));
        return(NULL);
    }
    xmlSetNs(encNode, ns);

    if(id != NULL) {
        xmlSetProp(encNode, xmlSecAttrId, id);
    }
    if(type != NULL) {
        xmlSetProp(encNode, xmlSecAttrType, type);
    }
    if(mimeType != NULL) {
        xmlSetProp(encNode, xmlSecAttrMimeType, mimeType);
    }
    if(encoding != NULL) {
        xmlSetProp(encNode, xmlSecAttrEncoding, encoding);
    }

    if(xmlSecTmplPrepareEncData(encNode, encMethodId) < 0) {
        xmlFreeNode(encNode);
        return(NULL);
    }
    return(encNode);
}

static int
xmlSecTmplPrepareEncData(xmlNodePtr parentNode, xmlSecTransformId encMethodId) {
    xmlNodePtr cur;

    xmlSecAssert2(parentNode != NULL, -1);
    xmlSecAssert2((encMethodId == NULL) || (encMethodId->href != NULL), -1);

    /* add EncryptionMethod node if requested */
    if(encMethodId != NULL) {
        cur = xmlSecAddChild(parentNode, xmlSecNodeEncryptionMethod, xmlSecEncNs);
        if(cur == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeEncryptionMethod)", NULL);
            return(-1);
        }
        if(xmlSetProp(cur, xmlSecAttrAlgorithm, encMethodId->href) == NULL) {
            xmlSecXmlError2("xmlSetProp", NULL,
                            "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
            return(-1);
        }
    }

    /* and CipherData node */
    cur = xmlSecAddChild(parentNode, xmlSecNodeCipherData, xmlSecEncNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeCipherData)", NULL);
        return(-1);
    }

    return(0);
}


/**
 * @brief Ensures a &lt;dsig:KeyInfo/&gt; child in the &lt;enc:EncryptedData/&gt; node.
 * @details Adds &lt;dsig:KeyInfo/&gt; to the  &lt;enc:EncryptedData/&gt; node @p encNode.
 * @param encNode the pointer to &lt;enc:EncryptedData/&gt; node.
 * @param id the Id attrbibute (optional).
 *
 * @return the pointer to newly created &lt;dsig:KeyInfo/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataEnsureKeyInfo(xmlNodePtr encNode, const xmlChar* id) {
    xmlNodePtr res;

    xmlSecAssert2(encNode != NULL, NULL);

    res = xmlSecFindChild(encNode, xmlSecNodeKeyInfo, xmlSecDSigNs);
    if(res == NULL) {
        xmlNodePtr cipherDataNode;

        cipherDataNode = xmlSecFindChild(encNode, xmlSecNodeCipherData, xmlSecEncNs);
        if(cipherDataNode == NULL) {
            xmlSecNodeNotFoundError("xmlSecFindChild", encNode,
                                    xmlSecNodeCipherData, NULL);
            return(NULL);
        }

        res = xmlSecAddPrevSibling(cipherDataNode, xmlSecNodeKeyInfo, xmlSecDSigNs);
        if(res == NULL) {
            xmlSecInternalError("xmlSecAddPrevSibling(xmlSecNodeKeyInfo)", NULL);
            return(NULL);
        }
    }
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    return(res);
}

/**
 * @brief Ensures a &lt;enc:EncryptionProperties/&gt; child in the &lt;enc:EncryptedData/&gt; node.
 * @details Adds &lt;enc:EncryptionProperties/&gt; node to the &lt;enc:EncryptedData/&gt;
 * node @p encNode.
 * @param encNode the pointer to &lt;enc:EncryptedData/&gt; node.
 * @param id the Id attribute (optional).
 *
 * @return the pointer to newly created &lt;enc:EncryptionProperties/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataEnsureEncProperties(xmlNodePtr encNode, const xmlChar *id) {
    xmlNodePtr res;

    xmlSecAssert2(encNode != NULL, NULL);

    res = xmlSecFindChild(encNode, xmlSecNodeEncryptionProperties, xmlSecEncNs);
    if(res == NULL) {
        res = xmlSecAddChild(encNode, xmlSecNodeEncryptionProperties, xmlSecEncNs);
        if(res == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeEncryptionProperties)", NULL);
            return(NULL);
        }
    }

    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }

    return(res);
}

/**
 * @brief Adds a &lt;enc:EncryptionProperty/&gt; node to the &lt;enc:EncryptedData/&gt; node.
 * @details Adds &lt;enc:EncryptionProperty/&gt; node (and the parent
 * &lt;enc:EncryptionProperties/&gt; node if required) to the
 * &lt;enc:EncryptedData/&gt; node @p encNode.
 * @param encNode the pointer to &lt;enc:EncryptedData/&gt; node.
 * @param id the Id attribute (optional).
 * @param target the Target attribute (optional).
 *
 * @return the pointer to newly created &lt;enc:EncryptionProperty/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataAddEncProperty(xmlNodePtr encNode, const xmlChar *id, const xmlChar *target) {
    xmlNodePtr encProps;
    xmlNodePtr res;

    xmlSecAssert2(encNode != NULL, NULL);

    encProps = xmlSecTmplEncDataEnsureEncProperties(encNode, NULL);
    if(encProps == NULL) {
        xmlSecInternalError("xmlSecTmplEncDataEnsureEncProperties", NULL);
        return(NULL);
    }

    res = xmlSecAddChild(encProps, xmlSecNodeEncryptionProperty, xmlSecEncNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeEncryptionProperty)", NULL);
        return(NULL);
    }
    if(id != NULL) {
        xmlSetProp(res, xmlSecAttrId, id);
    }
    if(target != NULL) {
        xmlSetProp(res, xmlSecAttrTarget, target);
    }

    return(res);
}

/**
 * @brief Ensures a &lt;enc:CipherValue/&gt; child in the &lt;enc:EncryptedData/&gt; node.
 * @details Adds &lt;enc:CipherValue/&gt; to the &lt;enc:EncryptedData/&gt; node @p encNode.
 * @param encNode the pointer to &lt;enc:EncryptedData/&gt; node.
 *
 * @return the pointer to newly created &lt;enc:CipherValue/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataEnsureCipherValue(xmlNodePtr encNode) {
    xmlNodePtr cipherDataNode;
    xmlNodePtr res, tmp;

    xmlSecAssert2(encNode != NULL, NULL);

    cipherDataNode = xmlSecFindChild(encNode, xmlSecNodeCipherData, xmlSecEncNs);
    if(cipherDataNode == NULL) {
        xmlSecNodeNotFoundError("xmlSecFindChild", encNode,
                                xmlSecNodeCipherData, NULL);
        return(NULL);
    }

    /* check that we don;t have CipherReference node */
    tmp = xmlSecFindChild(cipherDataNode, xmlSecNodeCipherReference, xmlSecEncNs);
    if(tmp != NULL) {
        xmlSecNodeAlreadyPresentError(cipherDataNode, xmlSecNodeCipherReference, NULL);
        return(NULL);
    }

    res = xmlSecFindChild(cipherDataNode, xmlSecNodeCipherValue, xmlSecEncNs);
    if(res == NULL) {
        res = xmlSecAddChild(cipherDataNode, xmlSecNodeCipherValue, xmlSecEncNs);
        if(res == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeCipherValue)", NULL);
            return(NULL);
        }
    }

    return(res);
}

/**
 * @brief Ensures a &lt;enc:CipherReference/&gt; child in the &lt;enc:EncryptedData/&gt; node.
 * @details Adds &lt;enc:CipherReference/&gt; node with specified URI attribute @p uri
 * to the &lt;enc:EncryptedData/&gt; node @p encNode.
 * @param encNode the pointer to &lt;enc:EncryptedData/&gt; node.
 * @param uri the URI attribute (may be NULL).
 *
 * @return the pointer to newly created &lt;enc:CipherReference/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataEnsureCipherReference(xmlNodePtr encNode, const xmlChar *uri) {
    xmlNodePtr cipherDataNode;
    xmlNodePtr res, tmp;

    xmlSecAssert2(encNode != NULL, NULL);

    cipherDataNode = xmlSecFindChild(encNode, xmlSecNodeCipherData, xmlSecEncNs);
    if(cipherDataNode == NULL) {
        xmlSecNodeNotFoundError("xmlSecFindChild", encNode,
                                xmlSecNodeCipherData, NULL);
        return(NULL);
    }

    /* check that we don;t have CipherValue node */
    tmp = xmlSecFindChild(cipherDataNode, xmlSecNodeCipherValue, xmlSecEncNs);
    if(tmp != NULL) {
        xmlSecNodeAlreadyPresentError(cipherDataNode, xmlSecNodeCipherValue, NULL);
        return(NULL);
    }

    res = xmlSecFindChild(cipherDataNode, xmlSecNodeCipherReference, xmlSecEncNs);
    if(res == NULL) {
        res = xmlSecAddChild(cipherDataNode, xmlSecNodeCipherReference, xmlSecEncNs);
        if(res == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeCipherReference)", NULL);
            return(NULL);
        }
    }

    if(uri != NULL) {
        xmlSetProp(res, xmlSecAttrURI, uri);
    }

    return(res);
}

/**
 * @brief Gets pointer to &lt;enc:EncryptionMethod/&gt; node.
 * @param encNode the pointer to <enc:EcnryptedData /> node.
 *
 * @return pointer to <enc:EncryptionMethod /> node or NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplEncDataGetEncMethodNode(xmlNodePtr encNode) {
    xmlSecAssert2(encNode != NULL, NULL);

    return(xmlSecFindChild(encNode, xmlSecNodeEncryptionMethod, xmlSecEncNs));
}

/**
 * @brief Adds a &lt;dsig:Transform/&gt; node to the &lt;enc:CipherReference/&gt; node.
 * @details Adds &lt;dsig:Transform/&gt; node (and the parent &lt;dsig:Transforms/&gt; node)
 * with specified transform methods @p transform to the &lt;enc:CipherReference/&gt;
 * child node of the &lt;enc:EncryptedData/&gt; node @p encNode.
 * @param cipherReferenceNode the pointer to &lt;enc:CipherReference/&gt; node.
 * @param transformId the transform id.
 *
 * @return the pointer to newly created &lt;dsig:Transform/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplCipherReferenceAddTransform(xmlNodePtr cipherReferenceNode,
                                  xmlSecTransformId transformId) {
    xmlNodePtr transformsNode;
    xmlNodePtr res;

    xmlSecAssert2(cipherReferenceNode != NULL, NULL);
    xmlSecAssert2(transformId != NULL, NULL);
    xmlSecAssert2(transformId->href != NULL, NULL);

    transformsNode = xmlSecFindChild(cipherReferenceNode, xmlSecNodeTransforms, xmlSecEncNs);
    if(transformsNode == NULL) {
        transformsNode = xmlSecAddChild(cipherReferenceNode, xmlSecNodeTransforms, xmlSecEncNs);
        if(transformsNode == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeTransforms)", NULL);
            return(NULL);
        }
    }

    res = xmlSecAddChild(transformsNode,  xmlSecNodeTransform, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeTransform)", NULL);
        return(NULL);
    }

    if(xmlSetProp(res, xmlSecAttrAlgorithm, transformId->href) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(res);
        xmlFreeNode(res);
        return(NULL);
    }

    return(res);
}


/******************************************************************************
 *
 * &lt;enc:EncryptedKey/&gt; node
 *
  *****************************************************************************/

/**
 * @brief Adds a &lt;enc:DataReference/&gt; node to the &lt;enc:EncryptedKey/&gt; node.
 * @details Adds &lt;enc:DataReference/&gt; and the parent &lt;enc:ReferenceList/&gt; node (if needed).
 * @param encNode the pointer to &lt;enc:EncryptedKey/&gt; node.
 * @param uri uri to reference (optional)
 *
 * @return the pointer to newly created &lt;enc:DataReference/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplReferenceListAddDataReference(xmlNodePtr encNode, const xmlChar *uri) {
    xmlNodePtr refListNode, res;

    xmlSecAssert2(encNode != NULL, NULL);

    refListNode = xmlSecFindChild(encNode, xmlSecNodeReferenceList, xmlSecEncNs);
    if(refListNode == NULL) {
        refListNode = xmlSecAddChild(encNode, xmlSecNodeReferenceList, xmlSecEncNs);
        if(refListNode == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeReferenceList)", NULL);
            return(NULL);
        }
    }

    res = xmlSecAddChild(refListNode,  xmlSecNodeDataReference, xmlSecEncNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeDataReference)", NULL);
        return(NULL);
    }

    if(uri != NULL) {
        if(xmlSetProp(res, xmlSecAttrURI, uri) == NULL) {
            xmlSecXmlError2("xmlSetProp", NULL,
                            "name=%s", xmlSecErrorsSafeString(xmlSecAttrURI));
            xmlUnlinkNode(res);
            xmlFreeNode(res);
            return(NULL);
        }
    }

    return(res);
}

/**
 * @brief Adds a &lt;enc:KeyReference/&gt; node to the &lt;enc:EncryptedKey/&gt; node.
 * @details Adds &lt;enc:KeyReference/&gt; and the parent &lt;enc:ReferenceList/&gt; node (if needed).
 * @param encNode the pointer to &lt;enc:EncryptedKey/&gt; node.
 * @param uri uri to reference (optional)
 *
 * @return the pointer to newly created &lt;enc:KeyReference/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplReferenceListAddKeyReference(xmlNodePtr encNode, const xmlChar *uri) {
    xmlNodePtr refListNode, res;

    xmlSecAssert2(encNode != NULL, NULL);

    refListNode = xmlSecFindChild(encNode, xmlSecNodeReferenceList, xmlSecEncNs);
    if(refListNode == NULL) {
        refListNode = xmlSecAddChild(encNode, xmlSecNodeReferenceList, xmlSecEncNs);
        if(refListNode == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeReferenceList)", NULL);
            return(NULL);
        }
    }

    res = xmlSecAddChild(refListNode,  xmlSecNodeKeyReference, xmlSecEncNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeKeyReference)", NULL);
        return(NULL);
    }

    if(uri != NULL) {
        if(xmlSetProp(res, xmlSecAttrURI, uri) == NULL) {
            xmlSecXmlError2("xmlSetProp", NULL,
                            "name=%s", xmlSecErrorsSafeString(xmlSecAttrURI));
            xmlUnlinkNode(res);
            xmlFreeNode(res);
            return(NULL);
        }
    }

    return(res);
}


/******************************************************************************
 *
 * &lt;dsig:KeyInfo/&gt; node
 *
  *****************************************************************************/

/**
 * @brief Adds a &lt;dsig:KeyName/&gt; node to the &lt;dsig:KeyInfo/&gt; node.
 * @details Adds &lt;dsig:KeyName/&gt; node to the &lt;dsig:KeyInfo/&gt; node @p keyInfoNode.
 * @param keyInfoNode the pointer to &lt;dsig:KeyInfo/&gt; node.
 * @param name the key name (optional).
 *
 * @return the pointer to the newly created &lt;dsig:KeyName/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplKeyInfoAddKeyName(xmlNodePtr keyInfoNode, const xmlChar* name) {
    xmlNodePtr res;
    int ret;

    xmlSecAssert2(keyInfoNode != NULL, NULL);

    res = xmlSecAddChild(keyInfoNode, xmlSecNodeKeyName, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeKeyName)", NULL);
        return(NULL);
    }
    if(name != NULL) {
        ret = xmlSecNodeEncodeAndSetContent(res, name);
        if(ret < 0) {
            xmlSecInternalError("xmlSecNodeEncodeAndSetContent", NULL);
            return(NULL);
        }
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:KeyValue/&gt; node to the &lt;dsig:KeyInfo/&gt; node.
 * @details Adds &lt;dsig:KeyValue/&gt; node to the &lt;dsig:KeyInfo/&gt; node @p keyInfoNode.
 * @param keyInfoNode the pointer to &lt;dsig:KeyInfo/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:KeyValue/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplKeyInfoAddKeyValue(xmlNodePtr keyInfoNode) {
    xmlNodePtr res;

    xmlSecAssert2(keyInfoNode != NULL, NULL);

    res = xmlSecAddChild(keyInfoNode, xmlSecNodeKeyValue, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeKeyValue)", NULL);
        return(NULL);
    }

    return(res);
}

/**
 * @brief Adds a &lt;dsig:X509Data/&gt; node to the &lt;dsig:KeyInfo/&gt; node.
 * @details Adds &lt;dsig:X509Data/&gt; node to the &lt;dsig:KeyInfo/&gt; node @p keyInfoNode.
 * @param keyInfoNode the pointer to &lt;dsig:KeyInfo/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:X509Data/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplKeyInfoAddX509Data(xmlNodePtr keyInfoNode) {
    xmlNodePtr res;

    xmlSecAssert2(keyInfoNode != NULL, NULL);

    res = xmlSecAddChild(keyInfoNode, xmlSecNodeX509Data, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509Data)", NULL);
        return(NULL);
    }

    return(res);
}

/**
 * @brief Adds a &lt;dsig:RetrievalMethod/&gt; node to the &lt;dsig:KeyInfo/&gt; node.
 * @details Adds &lt;dsig:RetrievalMethod/&gt; node to the &lt;dsig:KeyInfo/&gt; node @p keyInfoNode.
 * @param keyInfoNode the pointer to &lt;dsig:KeyInfo/&gt; node.
 * @param uri the URI attribute (optional).
 * @param type the Type attribute(optional).
 *
 * @return the pointer to the newly created &lt;dsig:RetrievalMethod/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplKeyInfoAddRetrievalMethod(xmlNodePtr keyInfoNode, const xmlChar *uri,
                             const xmlChar *type) {
    xmlNodePtr res;

    xmlSecAssert2(keyInfoNode != NULL, NULL);

    res = xmlSecAddChild(keyInfoNode, xmlSecNodeRetrievalMethod, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeRetrievalMethod)", NULL);
        return(NULL);
    }

    if(uri != NULL) {
        xmlSetProp(res, xmlSecAttrURI, uri);
    }
    if(type != NULL) {
        xmlSetProp(res, xmlSecAttrType, type);
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:Transform/&gt; node to the &lt;dsig:RetrievalMethod/&gt; node.
 * @details Adds &lt;dsig:Transform/&gt; node (and the parent &lt;dsig:Transforms/&gt; node
 * if required) to the &lt;dsig:RetrievalMethod/&gt; node @p retrMethod.
 * @param retrMethodNode the pointer to &lt;dsig:RetrievalMethod/&gt; node.
 * @param transformId the transform id.
 *
 * @return the pointer to the newly created &lt;dsig:Transforms/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplRetrievalMethodAddTransform(xmlNodePtr retrMethodNode, xmlSecTransformId transformId) {
    xmlNodePtr transformsNode;
    xmlNodePtr res;

    xmlSecAssert2(retrMethodNode != NULL, NULL);
    xmlSecAssert2(transformId != NULL, NULL);
    xmlSecAssert2(transformId->href != NULL, NULL);

    transformsNode = xmlSecFindChild(retrMethodNode, xmlSecNodeTransforms, xmlSecDSigNs);
    if(transformsNode == NULL) {
        transformsNode = xmlSecAddChild(retrMethodNode, xmlSecNodeTransforms, xmlSecDSigNs);
        if(transformsNode == NULL) {
            xmlSecInternalError("xmlSecAddChild(xmlSecNodeTransforms)", NULL);
            return(NULL);
        }
    }

    res = xmlSecAddChild(transformsNode,  xmlSecNodeTransform, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeTransform)", NULL);
        return(NULL);
    }

    if(xmlSetProp(res, xmlSecAttrAlgorithm, transformId->href) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(res);
        xmlFreeNode(res);
        return(NULL);
    }

    return(res);
}


/**
 * @brief Adds a &lt;enc:EncryptedKey/&gt; node to the &lt;dsig:KeyInfo/&gt; node.
 * @details Adds &lt;enc:EncryptedKey/&gt; node with given attributes to
 * the &lt;dsig:KeyInfo/&gt; node @p keyInfoNode.
 * @param keyInfoNode the pointer to &lt;dsig:KeyInfo/&gt; node.
 * @param encMethodId the encryption method (optional).
 * @param id the Id attribute (optional).
 * @param type the Type attribute (optional).
 * @param recipient the Recipient attribute (optional).
 *
 * @return the pointer to the newly created &lt;enc:EncryptedKey/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplKeyInfoAddEncryptedKey(xmlNodePtr keyInfoNode, xmlSecTransformId encMethodId,
                         const xmlChar* id, const xmlChar* type, const xmlChar* recipient) {
    xmlNodePtr encKeyNode;

    xmlSecAssert2(keyInfoNode != NULL, NULL);

    /* we allow multiple encrypted key elements */
    encKeyNode = xmlSecAddChild(keyInfoNode, xmlSecNodeEncryptedKey, xmlSecEncNs);
    if(encKeyNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeEncryptedKey)", NULL);
        return(NULL);
    }

    if(id != NULL) {
        xmlSetProp(encKeyNode, xmlSecAttrId, id);
    }
    if(type != NULL) {
        xmlSetProp(encKeyNode, xmlSecAttrType, type);
    }
    if(recipient != NULL) {
        xmlSetProp(encKeyNode, xmlSecAttrRecipient, recipient);
    }

    if(xmlSecTmplPrepareEncData(encKeyNode, encMethodId) < 0) {
        xmlUnlinkNode(encKeyNode);
        xmlFreeNode(encKeyNode);
        return(NULL);
    }
    return(encKeyNode);
}

/******************************************************************************
 *
 * &lt;dsig:X509Data/&gt; node
 *
  *****************************************************************************/
/**
 * @brief Adds a &lt;dsig:X509IssuerSerial/&gt; node to the &lt;dsig:X509Data/&gt; node.
 * @details Adds &lt;dsig:X509IssuerSerial/&gt; node to the given &lt;dsig:X509Data/&gt; node.
 * @param x509DataNode the pointer to &lt;dsig:X509Data/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:X509IssuerSerial/&gt; node or
 * NULL if an error occurs.
 */

xmlNodePtr
xmlSecTmplX509DataAddIssuerSerial(xmlNodePtr x509DataNode) {
    xmlNodePtr cur;

    xmlSecAssert2(x509DataNode != NULL, NULL);

    cur = xmlSecFindChild(x509DataNode, xmlSecNodeX509IssuerSerial, xmlSecDSigNs);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(x509DataNode, xmlSecNodeX509IssuerSerial, NULL);
        return(NULL);
    }

    cur = xmlSecAddChild(x509DataNode, xmlSecNodeX509IssuerSerial, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509IssuerSerial)", NULL);
        return(NULL);
    }

    return (cur);
}

/**
 * @brief Adds a &lt;dsig:X509IssuerName/&gt; node to the &lt;dsig:X509IssuerSerial/&gt; node.
 * @details Adds &lt;dsig:X509IssuerName/&gt; node to the &lt;dsig:X509IssuerSerial/&gt; node @p x509IssuerSerialNode.
 * @param x509IssuerSerialNode the pointer to &lt;dsig:X509IssuerSerial/&gt; node.
 * @param issuerName the issuer name (optional).
 *
 * @return the pointer to the newly created &lt;dsig:X509IssuerName/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplX509IssuerSerialAddIssuerName(xmlNodePtr x509IssuerSerialNode, const xmlChar* issuerName) {
    xmlNodePtr res;
    int ret;

    xmlSecAssert2(x509IssuerSerialNode != NULL, NULL);
    if(xmlSecFindChild(x509IssuerSerialNode, xmlSecNodeX509IssuerName, xmlSecDSigNs) != NULL) {
        xmlSecNodeAlreadyPresentError(x509IssuerSerialNode, xmlSecNodeX509IssuerName, NULL);
        return(NULL);
    }

    res = xmlSecAddChild(x509IssuerSerialNode, xmlSecNodeX509IssuerName, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509IssuerName)", NULL);
        return(NULL);
    }

    if (issuerName != NULL) {
        ret = xmlSecNodeEncodeAndSetContent(res, issuerName);
        if(ret < 0) {
            xmlSecInternalError("xmlSecNodeEncodeAndSetContent", NULL);
            return(NULL);
        }
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:X509SerialNumber/&gt; node to the &lt;dsig:X509IssuerSerial/&gt; node.
 * @details Adds &lt;dsig:X509SerialNumber/&gt; node to the &lt;dsig:X509IssuerSerial/&gt; node @p x509IssuerSerialNode.
 * @param x509IssuerSerialNode the pointer to &lt;dsig:X509IssuerSerial/&gt; node.
 * @param serial the serial number (optional).
 *
 * @return the pointer to the newly created &lt;dsig:X509SerialNumber/&gt; node or
 * NULL if an error occurs.
 */
xmlNodePtr
xmlSecTmplX509IssuerSerialAddSerialNumber(xmlNodePtr x509IssuerSerialNode, const xmlChar* serial) {
    xmlNodePtr res;
    int ret;

    xmlSecAssert2(x509IssuerSerialNode != NULL, NULL);

    if(xmlSecFindChild(x509IssuerSerialNode, xmlSecNodeX509SerialNumber, xmlSecDSigNs) != NULL) {
        xmlSecNodeAlreadyPresentError(x509IssuerSerialNode, xmlSecNodeX509SerialNumber, NULL);
        return(NULL);
    }

    res = xmlSecAddChild(x509IssuerSerialNode, xmlSecNodeX509SerialNumber, xmlSecDSigNs);
    if(res == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509SerialNumber)", NULL);
        return(NULL);
    }

    if (serial != NULL) {
        ret = xmlSecNodeEncodeAndSetContent(res, serial);
        if(ret < 0) {
            xmlSecInternalError("xmlSecNodeEncodeAndSetContent", NULL);
            return(NULL);
        }
    }
    return(res);
}

/**
 * @brief Adds a &lt;dsig:X509SubjectName/&gt; node to the &lt;dsig:X509Data/&gt; node.
 * @details Adds &lt;dsig:X509SubjectName/&gt; node to the given &lt;dsig:X509Data/&gt; node.
 * @param x509DataNode the pointer to &lt;dsig:X509Data/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:X509SubjectName/&gt; node or
 * NULL if an error occurs.
 */

xmlNodePtr
xmlSecTmplX509DataAddSubjectName(xmlNodePtr x509DataNode) {
    xmlNodePtr cur;

    xmlSecAssert2(x509DataNode != NULL, NULL);

    cur = xmlSecFindChild(x509DataNode, xmlSecNodeX509SubjectName, xmlSecDSigNs);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(x509DataNode, xmlSecNodeX509SubjectName, NULL);
        return(NULL);
    }

    cur = xmlSecAddChild(x509DataNode, xmlSecNodeX509SubjectName, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509SubjectName)", NULL);
        return(NULL);
    }

    return (cur);
}

/**
 * @brief Adds a &lt;dsig:X509SKI/&gt; node to the &lt;dsig:X509Data/&gt; node.
 * @details Adds &lt;dsig:X509SKI/&gt; node to the given &lt;dsig:X509Data/&gt; node.
 * @param x509DataNode the pointer to &lt;dsig:X509Data/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:X509SKI/&gt; node or
 * NULL if an error occurs.
 */

xmlNodePtr
xmlSecTmplX509DataAddSKI(xmlNodePtr x509DataNode) {
    xmlNodePtr cur;

    xmlSecAssert2(x509DataNode != NULL, NULL);

    cur = xmlSecFindChild(x509DataNode, xmlSecNodeX509SKI, xmlSecDSigNs);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(x509DataNode, xmlSecNodeX509SKI, NULL);
        return(NULL);
    }

    cur = xmlSecAddChild(x509DataNode, xmlSecNodeX509SKI, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509SKI)", NULL);
        return(NULL);
    }

    return (cur);
}

/**
 * @brief Adds a &lt;dsig11:X509Digest/&gt; node to the &lt;dsig:X509Data/&gt; node.
 * @details Adds &lt;dsig11:X509Digest/&gt; node to the given &lt;dsig:X509Data/&gt; node.
 * @param x509DataNode the pointer to &lt;dsig:X509Data/&gt; node.
 * @param digestAlgorithm the digest algorithm URL.
 *
 * @return the pointer to the newly created &lt;dsig11:X509Digest/&gt; node or
 * NULL if an error occurs.
 */

xmlNodePtr
xmlSecTmplX509DataAddDigest(xmlNodePtr x509DataNode, const xmlChar* digestAlgorithm) {
    xmlNodePtr cur;

    xmlSecAssert2(x509DataNode != NULL, NULL);
    xmlSecAssert2(digestAlgorithm != NULL, NULL);

    cur = xmlSecFindChild(x509DataNode, xmlSecNodeX509Digest, xmlSecDSig11Ns);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(x509DataNode, xmlSecNodeX509Digest, NULL);
        return(NULL);
    }

    cur = xmlSecAddChild(x509DataNode, xmlSecNodeX509Digest, xmlSecDSig11Ns);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509Digest)", NULL);
        return(NULL);
    }

    if(xmlSetProp(cur, xmlSecAttrAlgorithm, digestAlgorithm) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL, "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(cur);
        xmlFreeNode(cur);
        return(NULL);
    }

    return (cur);
}


/**
 * @brief Adds a &lt;dsig:X509Certificate/&gt; node to the &lt;dsig:X509Data/&gt; node.
 * @details Adds &lt;dsig:X509Certificate/&gt; node to the given &lt;dsig:X509Data/&gt; node.
 * @param x509DataNode the pointer to &lt;dsig:X509Data/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:X509Certificate/&gt; node or
 * NULL if an error occurs.
 */

xmlNodePtr
xmlSecTmplX509DataAddCertificate(xmlNodePtr x509DataNode) {
    xmlNodePtr cur;

    xmlSecAssert2(x509DataNode != NULL, NULL);

    cur = xmlSecFindChild(x509DataNode, xmlSecNodeX509Certificate, xmlSecDSigNs);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(x509DataNode, xmlSecNodeX509Certificate, NULL);
        return(NULL);
    }

    cur = xmlSecAddChild(x509DataNode, xmlSecNodeX509Certificate, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509Certificate)", NULL);
        return(NULL);
    }

    return (cur);
}

/**
 * @brief Adds a &lt;dsig:X509CRL/&gt; node to the &lt;dsig:X509Data/&gt; node.
 * @details Adds &lt;dsig:X509CRL/&gt; node to the given &lt;dsig:X509Data/&gt; node.
 * @param x509DataNode the pointer to &lt;dsig:X509Data/&gt; node.
 *
 * @return the pointer to the newly created &lt;dsig:X509CRL/&gt; node or
 * NULL if an error occurs.
 */

xmlNodePtr
xmlSecTmplX509DataAddCRL(xmlNodePtr x509DataNode) {
    xmlNodePtr cur;

    xmlSecAssert2(x509DataNode != NULL, NULL);

    cur = xmlSecFindChild(x509DataNode, xmlSecNodeX509CRL, xmlSecDSigNs);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(x509DataNode, xmlSecNodeX509CRL, NULL);
        return(NULL);
    }

    cur = xmlSecAddChild(x509DataNode, xmlSecNodeX509CRL, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeX509CRL)", NULL);
        return(NULL);
    }

    return (cur);
}

/******************************************************************************
 *
 * &lt;dsig:Transform/&gt; node
 *
  *****************************************************************************/

/**
 * @brief Creates a &lt;dsig:HMACOutputLength/&gt; child for the HMAC transform node.
 * @details Creates &lt;dsig:HMACOutputLength/&gt; child for the HMAC transform
 * node @p node.
 * @param transformNode the pointer to &lt;dsig:Transform/&gt; node
 * @param bitsLen the required length in bits
 *
 * @return 0 on success and a negative value otherwise.
 */
int
xmlSecTmplTransformAddHmacOutputLength(xmlNodePtr transformNode, xmlSecSize bitsLen) {
    xmlNodePtr cur;
    char buf[64];

    xmlSecAssert2(transformNode != NULL, -1);
    xmlSecAssert2(bitsLen > 0, -1);

    cur = xmlSecFindChild(transformNode, xmlSecNodeHMACOutputLength, xmlSecDSigNs);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeHMACOutputLength, NULL);
        return(-1);
    }

    cur = xmlSecAddChild(transformNode, xmlSecNodeHMACOutputLength, xmlSecDSigNs);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeHMACOutputLength)", NULL);
        return(-1);
    }

#if defined(_MSC_VER)
    sprintf_s(buf, sizeof(buf), XMLSEC_SIZE_FMT, bitsLen);
#else  /* defined(_MSC_VER) */
    sprintf(buf, XMLSEC_SIZE_FMT, bitsLen);
#endif /* defined(_MSC_VER) */

    xmlNodeSetContent(cur, BAD_CAST buf);
    return(0);
}

/**
 * @brief Creates a &lt;enc:OAEPParam/&gt; child node in the @p node.
 * @details Creates &lt;enc:OAEPParam/&gt; child node in the @p node.
 * @param transformNode the pointer to &lt;dsig:Transform/&gt; node.
 * @param buf the OAEP param buffer.
 * @param size the OAEP param buffer size.
 *
 * @return 0 on success or a negative value if an error occurs.
 */
int
xmlSecTmplTransformAddRsaOaepParam(xmlNodePtr transformNode, const xmlSecByte *buf, xmlSecSize size) {
    xmlNodePtr oaepParamNode;
    xmlChar *base64;

    xmlSecAssert2(transformNode != NULL, -1);
    xmlSecAssert2(buf != NULL, -1);
    xmlSecAssert2(size > 0, -1);

    oaepParamNode = xmlSecFindChild(transformNode, xmlSecNodeRsaOAEPparams, xmlSecEncNs);
    if(oaepParamNode != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeRsaOAEPparams, NULL);
        return(-1);
    }

    oaepParamNode = xmlSecAddChild(transformNode, xmlSecNodeRsaOAEPparams, xmlSecEncNs);
    if(oaepParamNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeRsaOAEPparams)", NULL);
        return(-1);
    }

    base64 = xmlSecBase64Encode(buf, size, 0);
    if(base64 == NULL) {
        xmlSecInternalError2("xmlSecBase64Encode", NULL, "size=" XMLSEC_SIZE_FMT, size);
        return(-1);
    }

    xmlNodeSetContent(oaepParamNode, base64);
    xmlFree(base64);
    return(0);
}

/**
 * @brief Creates &lt;enc:MGF/&gt; child node in the @p node.
 * @param transformNode the pointer to &lt;dsig:Transform/&gt; node.
 * @param algorithm MGF1 algorithm href.
 *
 * @return 0 on success or a negative value if an error occurs.
 */
int
xmlSecTmplTransformAddRsaMgf(xmlNodePtr transformNode,
                        const xmlChar *algorithm) {
    xmlNodePtr mgfNode;

    xmlSecAssert2(transformNode != NULL, -1);

    mgfNode = xmlSecFindChild(transformNode, xmlSecNodeRsaMGF, xmlSecEnc11Ns);
    if(mgfNode != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeRsaMGF, NULL);
        return(-1);
    }

    mgfNode = xmlSecAddChild(transformNode, xmlSecNodeRsaMGF, xmlSecEnc11Ns);
    if(mgfNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeRsaMgf)", NULL);
        return(-1);
    }

    if(xmlSetProp(mgfNode, xmlSecAttrAlgorithm, algorithm) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(mgfNode);
        xmlFreeNode(mgfNode);
        return(-1);
    }

    return(0);
}

/**
 * @brief Creates a &lt;dsig:DigestMethod/&gt; child node in the @p node.
 * @details Creates &lt;dsig:DigestMethod/&gt; child node in the @p node.
 * @param transformNode the pointer to &lt;dsig:Transform/&gt; node.
 * @param algorithm digest algorithm href.
 *
 * @return 0 on success or a negative value if an error occurs.
 */
int
xmlSecTmplTransformAddRsaDigest(xmlNodePtr transformNode,
                        const xmlChar *algorithm) {
    xmlNodePtr digestNode;

    xmlSecAssert2(transformNode != NULL, -1);

    digestNode = xmlSecFindChild(transformNode, xmlSecNodeDigestMethod, xmlSecDSigNs);
    if(digestNode != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeDigestMethod, NULL);
        return(-1);
    }

    digestNode = xmlSecAddChild(transformNode, xmlSecNodeDigestMethod, xmlSecDSigNs);
    if(digestNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeDigestMethod)", NULL);
        return(-1);
    }

    if(xmlSetProp(digestNode, xmlSecAttrAlgorithm, algorithm) == NULL) {
        xmlSecXmlError2("xmlSetProp", NULL,
                        "name=%s", xmlSecErrorsSafeString(xmlSecAttrAlgorithm));
        xmlUnlinkNode(digestNode);
        xmlFreeNode(digestNode);
        return(-1);
    }

    return(0);
}

/**
 * @brief Writes an XSLT transform expression to the &lt;dsig:Transform/&gt; node.
 * @details Writes the XSLT transform expression to the @p node.
 * @param transformNode the pointer to &lt;dsig:Transform/&gt; node.
 * @param xslt the XSLT transform expression.
 *
 * @return 0 on success or a negative value otherwise.
 */
int
xmlSecTmplTransformAddXsltStylesheet(xmlNodePtr transformNode, const xmlChar *xslt) {
    xmlDocPtr xsltDoc;
    int ret;

    xmlSecAssert2(transformNode != NULL, -1);
    xmlSecAssert2(xslt != NULL, -1);

    xsltDoc = xmlReadMemory((const char*)xslt, xmlStrlen(xslt), NULL, NULL, xmlSecParserGetDefaultOptions() | XML_PARSE_PEDANTIC);
    if(xsltDoc == NULL) {
        xmlSecXmlError("xmlReadMemory", NULL);
        return(-1);
    }

    ret = xmlSecReplaceContent(transformNode, xmlDocGetRootElement(xsltDoc));
    if(ret < 0) {
        xmlSecInternalError("xmlSecReplaceContent", NULL);
        xmlFreeDoc(xsltDoc);
        return(-1);
    }

    xmlFreeDoc(xsltDoc);
    return(0);
}

/**
 * @brief Adds inclusive namespaces to the ExcC14N transform node.
 * @details Adds "inclusive" namespaces to the ExcC14N transform node @p node.
 * @param transformNode the pointer to &lt;dsig:Transform/&gt; node.
 * @param prefixList the white space delimited  list of namespace prefixes,
 *                      where "#default" indicates the default namespace
 *                      (optional).
 *
 * @return 0 if success or a negative value otherwise.
 */
int
xmlSecTmplTransformAddC14NInclNamespaces(xmlNodePtr transformNode,
                                         const xmlChar *prefixList) {
    xmlNodePtr cur;

    xmlSecAssert2(transformNode != NULL, -1);
    xmlSecAssert2(prefixList != NULL, -1);

    cur = xmlSecFindChild(transformNode, xmlSecNodeInclusiveNamespaces, xmlSecNsExcC14N);
    if(cur != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeInclusiveNamespaces, NULL);
        return(-1);
    }

    cur = xmlSecAddChild(transformNode, xmlSecNodeInclusiveNamespaces, xmlSecNsExcC14N);
    if(cur == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeInclusiveNamespaces)",
                            xmlSecNodeGetName(transformNode));
        return(-1);
    }

    xmlSetProp(cur, xmlSecAttrPrefixList, prefixList);
    return(0);
}

/**
 * @brief Writes XPath transform information to the &lt;dsig:Transform/&gt; node.
 * @details Writes XPath transform information to the &lt;dsig:Transform/&gt; node
 * @p node.
 * @param transformNode the pointer to the &lt;dsig:Transform/&gt; node.
 * @param expression the XPath expression.
 * @param nsList the NULL terminated list of namespace prefix/href pairs
 *                      (optional).
 *
 * @return 0 for success or a negative value otherwise.
 */
int
xmlSecTmplTransformAddXPath(xmlNodePtr transformNode, const xmlChar *expression,
                         const xmlChar **nsList) {
    xmlNodePtr xpathNode;
    int ret;

    xmlSecAssert2(transformNode != NULL, -1);
    xmlSecAssert2(expression != NULL, -1);

    xpathNode = xmlSecFindChild(transformNode, xmlSecNodeXPath, xmlSecDSigNs);
    if(xpathNode != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeXPath, NULL);
        return(-1);
    }

    xpathNode = xmlSecAddChild(transformNode, xmlSecNodeXPath, xmlSecDSigNs);
    if(xpathNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeXPath)", NULL);
        return(-1);
    }

    ret = xmlSecNodeEncodeAndSetContent(xpathNode, expression);
    if(ret < 0) {
        xmlSecInternalError("xmlSecNodeEncodeAndSetContent", NULL);
        return(-1);
    }

    return((nsList != NULL) ? xmlSecTmplNodeWriteNsList(xpathNode, nsList) : 0);
}

/**
 * @brief Writes XPath2 transform information to the &lt;dsig:Transform/&gt; node.
 * @details Writes XPath2 transform information to the &lt;dsig:Transform/&gt; node
 * @p node.
 * @param transformNode the pointer to the &lt;dsig:Transform/&gt; node.
 * @param type the XPath2 transform type ("union", "intersect" or "subtract").
 * @param expression the XPath expression.
 * @param nsList the NULL terminated list of namespace prefix/href pairs.
 *                      (optional).
 *
 * @return 0 for success or a negative value otherwise.
 */
int
xmlSecTmplTransformAddXPath2(xmlNodePtr transformNode, const xmlChar* type,
                        const xmlChar *expression, const xmlChar **nsList) {
    xmlNodePtr xpathNode;
    int ret;

    xmlSecAssert2(transformNode != NULL, -1);
    xmlSecAssert2(type != NULL, -1);
    xmlSecAssert2(expression != NULL, -1);

    xpathNode = xmlSecAddChild(transformNode, xmlSecNodeXPath, xmlSecXPath2Ns);
    if(xpathNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeXPath)", NULL);
        return(-1);
    }
    xmlSetProp(xpathNode, xmlSecAttrFilter, type);

    ret = xmlSecNodeEncodeAndSetContent(xpathNode, expression);
    if(ret < 0) {
        xmlSecInternalError("xmlSecNodeEncodeAndSetContent", NULL);
        return(-1);
    }

    return((nsList != NULL) ? xmlSecTmplNodeWriteNsList(xpathNode, nsList) : 0);
}

/**
 * @brief Writes XPointer transform information to the &lt;dsig:Transform/&gt; node.
 * @details Writes XPointer transform information to the &lt;dsig:Transform/&gt; node
 * @p node.
 * @param transformNode the pointer to the &lt;dsig:Transform/&gt; node.
 * @param expression the XPath expression.
 * @param nsList the NULL terminated list of namespace prefix/href pairs.
 *                      (optional).
 *
 * @return 0 for success or a negative value otherwise.
 */
int
xmlSecTmplTransformAddXPointer(xmlNodePtr transformNode, const xmlChar *expression,
                         const xmlChar **nsList) {
    xmlNodePtr xpointerNode;
    int ret;

    xmlSecAssert2(expression != NULL, -1);
    xmlSecAssert2(transformNode != NULL, -1);

    xpointerNode = xmlSecFindChild(transformNode, xmlSecNodeXPointer, xmlSecXPointerNs);
    if(xpointerNode != NULL) {
        xmlSecNodeAlreadyPresentError(transformNode, xmlSecNodeXPointer, NULL);
        return(-1);
    }

    xpointerNode = xmlSecAddChild(transformNode, xmlSecNodeXPointer, xmlSecXPointerNs);
    if(xpointerNode == NULL) {
        xmlSecInternalError("xmlSecAddChild(xmlSecNodeXPointer)", NULL);
        return(-1);
    }

    ret = xmlSecNodeEncodeAndSetContent(xpointerNode, expression);
    if(ret < 0) {
        xmlSecInternalError("xmlSecNodeEncodeAndSetContent", NULL);
        return(-1);
    }

    return((nsList != NULL) ? xmlSecTmplNodeWriteNsList(xpointerNode, nsList) : 0);
}

static int
xmlSecTmplNodeWriteNsList(xmlNodePtr parentNode, const xmlChar** nsList) {
    xmlNsPtr ns;
    const xmlChar *prefix;
    const xmlChar *href;
    const xmlChar **ptr;

    xmlSecAssert2(parentNode != NULL, -1);
    xmlSecAssert2(nsList != NULL, -1);

    /* nsList contains pairs of prefix/href with NULL at the end. We use special
    "#default" prefix instead of NULL prefix */
    ptr = nsList;
    while((*ptr) != NULL) {
        /* get next prefix/href pair */
        if(xmlStrEqual(BAD_CAST "#default", (*ptr))) {
            prefix = NULL;
        } else {
            prefix = (*ptr);
        }
        href = *(++ptr);
        if(href == NULL) {
            xmlSecInvalidDataError("unexpected end of ns list", NULL);
            return(-1);
        }

        /* create namespace node */
        ns = xmlNewNs(parentNode, href, prefix);
        if(ns == NULL) {
            xmlSecXmlError2("xmlNewNs", NULL,
                            "prefix=%s", xmlSecErrorsSafeString(prefix));
            return(-1);
        }

        /* next pair */
        ++ptr;
    }
    return(0);
}