对于相当冗长的代码块,我提前表示歉意,但它是我可以生成的最小的可编译示例。我已经省略了原始代码中的所有错误检查。我使用的是Visual Studio 2012和.NET 4.5,虽然这对于4.5来说并不是什么新东西,但它应该适用于任何版本。XmlElement的Xml签名无法验证
我试图签署一份XML文档的元素来保护它们免遭篡改。我不想保护整个文件,但只保留某些元素。也许甚至有不同的键的不同元素。
但是,当我签署三个示例元素并尝试验证它们时,第一个元素总是验证,另外两个元素失败。更糟糕的是,如果我在签名后修改它,第一个甚至会成功。我搜索了很多,阅读了很多教程,甚至asked a theoretical question here,但我没有任何线索我做错了什么。任何人都可以发现我的错误吗?
注意:我很乐意提供与周五的问题相同的赏金给任何解决此问题的人。
的证书是由执行创建:
“C:\ Program Files文件(x86)的\微软的SDK \的Windows \ v7.1A \ BIN \ makecert” -r -pe -n“CN = XMLDSIG_Test “-b 2013年1月1日-e 2014年1月1日签署-sky我-sS
测试XML文件:
<?xml version="1.0" encoding="utf-8" ?>
<PackageRoot>
<Package>
<Changes >
<Change/>
</Changes>
</Package>
<Package>
<Changes>
<Change/>
<Change/>
</Changes>
</Package>
<Package>
<Changes>
<Change/>
<Change/>
<Change/>
</Changes>
</Package>
</PackageRoot>
的代码签名和验证:
namespace SOExample
{
using System;
using System.Security.Cryptography.X509Certificates;
using System.Security.Cryptography.Xml;
using System.Xml;
public static class Program
{
public static void Sign(this XmlElement element, X509Certificate2 certificate)
{
var identifier = Guid.NewGuid().ToString();
element.SetAttribute("Id", identifier);
var signedXml = new SignedXml(element) { SigningKey = certificate.PrivateKey };
var reference = new Reference("#" + identifier);
reference.AddTransform(new XmlDsigEnvelopedSignatureTransform());
signedXml.AddReference(reference);
signedXml.ComputeSignature();
var xmlDigitalSignature = signedXml.GetXml();
element.AppendChild(element.OwnerDocument.ImportNode(xmlDigitalSignature, true));
}
public static bool VerifySignature(this XmlElement element, X509Certificate2 certificate)
{
var signedXml = new SignedXml(element);
XmlNodeList nodeList = element.GetElementsByTagName("Signature");
if (nodeList.Count != 1) return false;
signedXml.LoadXml((XmlElement)nodeList[0]);
return signedXml.CheckSignature(certificate, true);
}
public static void Main()
{
var xmlDoc = new XmlDocument { PreserveWhitespace = true };
xmlDoc.Load("ExamplePackage.xml");
var certificate = GetCertificateBySubject("CN=XMLDSIG_Test");
foreach (XmlElement root in xmlDoc.GetElementsByTagName("PackageRoot"))
{
foreach (XmlElement package in root.GetElementsByTagName("Package"))
{
package.Sign(certificate);
}
}
xmlDoc.Save("test_signed.xml");
Console.WriteLine("XML file signed.");
Console.WriteLine("Press any key to verify");
Console.ReadLine();
var signedDoc = new XmlDocument();
signedDoc.Load("test_signed.xml");
foreach (XmlElement root in xmlDoc.GetElementsByTagName("PackageRoot"))
{
foreach (XmlElement package in root.GetElementsByTagName("Package"))
{
Console.Write("Verifying Package " + package.GetAttribute("Id"));
var success = package.VerifySignature(certificate);
Console.WriteLine(success ? " successful!" : " failed!");
}
}
Console.WriteLine("Done.");
Console.ReadLine();
}
private static X509Certificate2 GetCertificateBySubject(string certificateSubject)
{
var store = new X509Store("My", StoreLocation.CurrentUser);
store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
foreach (X509Certificate2 c in store.Certificates)
{
if (c.Subject == certificateSubject)
{
store.Close();
return c;
}
}
store.Close();
return null;
}
}
}
如果你下了一些东西,请留下评论,这样海报可以改进。 – nvoigt 2013-05-23 18:44:04