C#对单个XML元素的RSA SHA 256签名的支持

Question

我遇到了具有的阻止程序。NET Framework 4.5版用于使用数字签名对XML进行签名。

我的问题是，需要使用RSA SHA-256算法使用X.509证书对单个XML元素进行签名。我读过很多书。NET就这个主题发表了文章，似乎有一个最初在CLR安全项目RSAPKCS1SHA256SignatureDescription中开发的解决方案。cs类。RSAPKCS1SHA256SignatureDescription当然已经被纳入了。net运行时和截至。NET 4.5现在在分布式二进制系统下可用。部署。dll。我在中尝试了上述解决方案。NET使用RSA SHA-256对特定XML元素进行签名，但尚未取得任何成功。

我正在尝试使用WSSE令牌签署符合Oasis ebms标准的SOAP消息。请注意，该类是为满足带有附件的Soap（SwA）和签署单个附件而编写的。我的代码如下

我的代码如下：

using System;
using System.Collections.Generic;
using System.IO;
using System.IdentityModel.Tokens;
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Security.Cryptography.Xml;
using System.ServiceModel.Channels;
using System.ServiceModel.Security;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Serialization;
using System.Deployment.Internal.CodeSigning;

namespace TestCSharpX509CertificateRSSHA256
{
    public class SignatureSupportUtility
    {

    private bool IsSignatureContentTransform
    {
        get
        {
          return true;
          //get IsSignatureContentTransform                
        }
    }

       public SignatureSupportUtility()
       {
          Register();
       }


    private static void Register()
    {
        CryptoConfig.AddAlgorithm(typeof(RSAPKCS1SHA256SignatureDescription), "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256");
    }

    private void Sign(Message message, string[] elementIdsToSign, string[] attachmentsToSign, string wssNamespace, X509Certificate2 certificate)
    {
       //Prepare XML to encrypt and sign
       var element = this.PrepareEncyrptSign(message);

            bool signEntireDocument = true;
            string elementToBeSigned = string.Empty;
            var signedMessage = new XmlDocument();
            signedMessage.AppendChild(signedMessage.ImportNode(element, true));

            SignatureType signAs = SignatureType.InternallyDetached;
            signedMessage.PreserveWhitespace = false;

            OverrideSignedXml signedXml = new OverrideSignedXml(signedMessage);
            signedXml.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigExcC14NTransformUrl;

            if (elementIdsToSign != null && elementIdsToSign.Length > 0)
            {
                bool isContentTransform = this.IsSignatureContentTransform;

                foreach (string s in elementIdsToSign)
                {
                    // Create a reference to be signed.
                    Reference reference = new Reference(string.Format("#{0}", s));
                    reference.AddTransform(new XmlDsigExcC14NTransform());
                    reference.DigestMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";


                    // Add the reference to the SignedXml object.
                    signedXml.AddReference(reference);
                }

                signEntireDocument = false;
            }

            // Reference attachments to sign
            if (attachmentsToSign != null && attachmentsToSign.Length > 0)
            {
                bool isContentTransform = this.IsSignatureContentTransform;

                foreach (string attachmentId in attachmentsToSign)
                {
                    // Create a reference to be signed.
                    Reference reference = new Reference(string.Format("{0}{1}", Constants.CidUriScheme, attachmentId));
                    reference.DigestMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";

                    if (isContentTransform)
                    {
                        AttachmentContentSignatureTransform env = new AttachmentContentSignatureTransform();
                        reference.AddTransform(env);
                    }
                    else
                    {
                        AttachmentCompleteSignatureTransform env = new AttachmentCompleteSignatureTransform();
                        reference.AddTransform(env);
                    }

                    // Add the reference to the SignedXml object.
                    signedXml.AddReference(reference);
                }

                signEntireDocument = false;
            }

            if (signEntireDocument)
            {
                Reference reference = new Reference();
                reference.Uri = "";
                reference.DigestMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";

                XmlDsigEnvelopedSignatureTransform env = new XmlDsigEnvelopedSignatureTransform();
                reference.AddTransform(env);
                signedXml.AddReference(reference);
                signAs = SignatureType.Enveloped;
            }

            string x509CertificateReferenceId = string.Format("{0}-{1}", Constants.IdAttributeName, Guid.NewGuid().ToString("N"));
            KeyInfo keyInfo = new KeyInfo();
            keyInfo.AddClause(new KeyInfoX509SecurityTokenReference(string.Format("#{0}", x509CertificateReferenceId), wssNamespace));
            signedXml.KeyInfo = keyInfo;
           signedXml.SignedInfo.SignatureMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";

           RSA  key = (RSACryptoServiceProvider)certificate.PrivateKey;
           signedXML.SigningKey = key;
            CidWebRequest.Message = message;

            signedXml.ComputeSignature();
            var xmlSignature = signedXml.GetXml();
            XmlDocument unsignedEnvelopeDoc = new XmlDocument();
            unsignedEnvelopeDoc.LoadXml(message.MessageAsString); }}} 

using System;
using System.Collections.Generic;
using System.IO;
using System.IdentityModel.Tokens;
using System.Security;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Security.Cryptography.Xml;
using System.ServiceModel.Channels;
using System.ServiceModel.Security;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Xml.Serialization;
using System.Deployment.Internal.CodeSigning;


namespace TestCSharpX509CertificateRSSHA256
{
public sealed class OverrideSignedXml : SignedXml
{
    public OverrideSignedXml()
        : base()
    {
    }

    public OverrideSignedXml(XmlDocument doc)
        : base(doc)
    {
    }

    public override XmlElement GetIdElement(XmlDocument document, string idValue)
    {
        XmlElement element = base.GetIdElement(document, idValue);

        if (element == null)
        {
            XmlNamespaceManager nsmgr = new XmlNamespaceManager(document.NameTable);
            nsmgr.AddNamespace("wsu", ="http://docs.oasis-open. org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd");

            element = document.SelectSingleNode("//*[@wsu:Id=\"" + idValue + "\"]", nsmgr) as XmlElement;
        }

        return element;
    }
}

}

我的SignatureSupportUtility类中的Sign方法应该足以对单个XML元素或整个消息进行签名，但是我一直收到一个加密异常，声称不支持SHA-256。我认为，从RSAPKCS1SHA256SignatureDescription来看，这个异常应该是无效的。cs已注册。然而，注意到SignedXML类不包括SHA-256的名称空间，只有SHA-128，我开始怀疑无论注册如何，是否支持SHA 256。

请有人告诉我如何最好地解决我的问题，并能够通过RSA SHA 256算法使用X.509证书对XML进行签名？

Answer 1

不幸的是，当无法导出私钥时，Andrew的答案不适用。

我正在使用智能卡，到目前为止，我还没有找到将SignedXML与SHA-256一起使用的方法。此功能似乎在RSACryptoServiceProvider的当前实现中被破坏了。

在我看来，唯一的解决方案是从CSP切换到PKCS#11，然后使用BouncyCastle。网。重写一切。

Answer 2

我也在看绿洲ebms的东西。

我找不到这篇文章，但我使用了4.5中的类：

public class RsaPkCs1Sha256SignatureDescription : SignatureDescription
{
    public RsaPkCs1Sha256SignatureDescription()
    {
        KeyAlgorithm = "System.Security.Cryptography.RSACryptoServiceProvider";
        DigestAlgorithm = "System.Security.Cryptography.SHA256Managed";
        FormatterAlgorithm = "System.Security.Cryptography.RSAPKCS1SignatureFormatter";
        DeformatterAlgorithm = "System.Security.Cryptography.RSAPKCS1SignatureDeformatter";
    }

    public override AsymmetricSignatureDeformatter CreateDeformatter(AsymmetricAlgorithm key)
    {
        var asymmetricSignatureDeformatter = (AsymmetricSignatureDeformatter) CryptoConfig.CreateFromName(DeformatterAlgorithm);
        asymmetricSignatureDeformatter.SetKey(key);
        asymmetricSignatureDeformatter.SetHashAlgorithm("SHA256");
        return asymmetricSignatureDeformatter;
    }

然后用这样的东西签名（已经编辑了一些不相关的部分）：

    public XmlElement SignDocument(XmlDocument doc, List<string> idsToSign)
    {
        CryptoConfig.AddAlgorithm(typeof(RsaPkCs1Sha256SignatureDescription), @"http://www.w3.org/2001/04/xmldsig-more#rsa-sha256");

        var cspParams = new CspParameters(24) { KeyContainerName = "XML_DISG_RSA_KEY" };
        var key = new RSACryptoServiceProvider(cspParams);
        key.FromXmlString(_x509SecurityToken.Certificate.PrivateKey.ToXmlString(true));

        var signer = new SoapSignedXml(doc) { SigningKey = key };

        signer.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigExcC14NTransformUrl;

        var keyInfo = new KeyInfo();
        keyInfo.AddClause(new SecurityTokenReference(_x509SecurityToken, SecurityTokenReference.SerializationOptions.Embedded));

        signer.KeyInfo = keyInfo;
        signer.SignedInfo.SignatureMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";

        var cn14Transform = new XmlDsigExcC14NTransform();
        string referenceDigestMethod = "http://www.w3.org/2001/04/xmlenc#sha256";

        foreach (string id in idsToSign)
        {
            var reference = new Reference("#" + id);
            reference.AddTransform(cn14Transform);
            reference.DigestMethod = referenceDigestMethod;
            signer.AddReference(reference);
        }

        signer.ComputeSignature();

        return signer.GetXml();
    }

似乎工作正常，并在另一端验证OK。前几天用Holodeck进行了测试，我认为它在签名元素中丢失的时间戳上失败了。

然而，附件的签署似乎是中的一个真正问题。NET-我认为根本不支持相关的转换。