<?php
$xml = new XMLWriter();

//$xml->openUri("php://output");
$xml->openURI('test.xml');

$xml->setIndentString('  ');
$xml->setIndent(true);

$xml->startDocument('1.0', 'utf-8');

$xml->startElement("RootInfo");
$xml->startElementNS("NS","Item",'http://www.woojean.com/');
//添加属性
$xml->writeAttribute("type", "1");

$xml->startElementNS("NS","id",null);
$xml->text("01");
$xml->endElement();

$xml->startElement("name");
$xml->text("woojean");
$xml->endElement();

$xml->endElement();
$xml->endElement();
$xml->endDocument();

//header("Content-type: text/xml");
//echo $xml->outputMemory();

<?php
require_once '/Users/wujian/projects/demo/xmlseclibs/src/XMLSecEnc.php';
require_once '/Users/wujian/projects/demo/xmlseclibs/src/XMLSecurityDSig.php';
require_once '/Users/wujian/projects/demo/xmlseclibs/src/XMLSecurityKey.php';

use RobRichards\XMLSecLibs\XMLSecEnc;
use RobRichards\XMLSecLibs\XMLSecurityDSig;
use RobRichards\XMLSecLibs\XMLSecurityKey;

$privateKey = '/Users/wujian/projects/demo/test/app_private.pem';
$publicKey = '/Users/wujian/projects/demo/test/app_public.pem';
$dumpPath = '/Users/wujian/projects/demo/dump3.xml';

$xmlStr = '<?xml version="1.0" encoding="UTF-8"?>
<RootInfo>
  <NS:Item type="3" xmlns:NS="http://www.woojean.com/">
    <NS:id>021</NS:id>
    <name>woojean</name>
  </NS:Item>
</RootInfo>';

<?php
$doc = new DOMDocument();
$doc->loadXML($xmlStr);

$objDSig = new XMLSecurityDSig();
$objDSig->setCanonicalMethod(XMLSecurityDSig::EXC_C14N);
$objDSig->addReference(
    $doc,
    XMLSecurityDSig::SHA256,
    ['http://www.w3.org/2000/09/xmldsig#enveloped-signature']
);

$objKey = new XMLSecurityKey(XMLSecurityKey::RSA_SHA256, ['type' => 'private']);
$objKey->loadKey($privateKey, TRUE);
// $objKey->passphrase = '<passphrase>';  // 密码

$objDSig->sign($objKey);
$keyNameNode = $objDSig->sigNode->ownerDocument->createElementNS('http://www.w3.org/2000/09/xmldsig#', 'ds:KeyName','my_public_key');
$objDSig->appendToKeyInfo($keyNameNode);
$objDSig->add509Cert(file_get_contents($publicKey));
$objDSig->appendSignature($doc->documentElement);

$doc->save($dumpPath);

<?php
$doc = new DOMDocument();
$doc->load($dumpPath);

$objXMLSecDSig = new XMLSecurityDSig();
$objDSig = $objXMLSecDSig->locateSignature($doc);
$objXMLSecDSig->canonicalizeSignedInfo();
$objKey = $objXMLSecDSig->locateKey();

XMLSecEnc::staticLocateKeyInfo($objKey, $objDSig);
$publicKey = $objKey->getX509Certificate();

$keyAlgorithm = $objKey->getAlgorith();

// Check signature
$ret = $objXMLSecDSig->verify($objKey);
if (1 !== $ret) {
    var_dump('wrong!');
    return FALSE;
}
else{
    var_dump('ok!');
}

// Check references (data)
try {
    $objXMLSecDSig->validateReference();
} catch (\Exception $e) {
    return FALSE;
}