C# SSO SAML的签名XML签名验证（使用sha256）

在windows 2003 server上使用VS 2008和.Net Framework 3.5

为了安全起见，我们使用SAML实现了SSO。我们在服务提供者端工作，验证从客户机系统生成的签名XML SAML Assertuib令牌。 到目前为止，我们遇到的任何签名文档都使用签名算法“rsa-sha1”，但现在我们有了一个新客户，他发送了一个签名算法为“rsa-sha256”的文件，问题开始了

public static string VerifySignature()
{
    if (m_xmlDoc == null)
        return "Could not load XMLDocument ";

    try
    {
        XmlNamespaceManager nsm = new XmlNamespaceManager(new NameTable());
        nsm.AddNamespace("dsig", SignedXml.XmlDsigNamespaceUrl);
        XmlElement sigElt = (XmlElement)m_xmlDoc.SelectSingleNode(
            "//dsig:Signature", nsm);

        // Load the signature for verification
        SignedXml sig = new SignedXml(m_xmlDoc);
        sig.LoadXml(sigElt);

        if (!sig.CheckSignature())
            return "Invalid Signature";
    }
    catch (Exception ex)
    {
        return ex.Message;
    }
    return string.Empty;
}

现在，当我为这个新客户（使用签名算法rsa-sha256h）尝试相同的代码时，这不起作用，我得到错误“无法为提供的签名算法创建SignatureDescription”

在过去的2-3天里，我浏览了很多博客和文章，发现SignedXml不支持sha256。好的但是接下来呢。在提到使用WIF的地方，我也检查并尝试了

我还尝试使用RSAPKCS1 SignatureFormatter的VerifySignature方法。但不确定要传递的两个参数是什么。

这符合“简单”但可能不是“解决方案”：）对于我们遇到的少数客户，我们已要求他们将其IdP更改为使用SHA-1签名。他们能够改变它，当他们这样做的时候，它是有效的

不是一个技术解决方案，但它“在现场”起到了作用，所以我想我应该提到它。

对于.net 4和更早版本， 我发现，一旦添加了安全性，下面的方法就可以工作了

（注意X509CertificateFinder是我自己的，通过指纹在证书存储中查找签名证书）

//
///验证XmlDocuments签名
/// 
///带有要验证的签名元素集的saml响应
///如果可以使用证书验证签名，则为True
public bool ValidateX509CertificateSignature（XmlDocument xnlDoc）
{
XmlNodeList XMLSignatures=xnlDoc.GetElementsByTagName（“签名”）http://www.w3.org/2000/09/xmldsig#");
//检查响应或断言是否已签名一次且仅签名一次。
如果（XMLSignatures.Count！=1）返回false；
var signedXmlDoc=新的SignedXml（xnlDoc）；
signedXmlDoc.LoadXml（（xmlement）XMLSignatures[0]）；
var certFinder=new X509CertificateFinder（）；
var foundCert=certFinder.GetSignatureCertificate（）；
CryptoConfig.AddAlgorithm（类型（RSAPKCS1SHA256SignatureDescription），”http://www.w3.org/2001/04/xmldsig-more#rsa-sha256”）；
返回signedXmlDoc.CheckSignature（foundCert，false）；
}
dotnet4.6.2+内置了较新的
sha
哈希。对于dotnet 4+，要访问rsa-sha512、rsa-sha384和rsa-sha256，您应该在某处包含此代码

/// <summary>Declare the signature type for rsa-sha512</summary>
public class RsaPkCs1Sha512SignatureDescription : SignatureDescription
{
    public RsaPkCs1Sha512SignatureDescription()
    {
        KeyAlgorithm = typeof(RSACryptoServiceProvider).FullName;
        DigestAlgorithm = typeof(SHA512CryptoServiceProvider).FullName;
        FormatterAlgorithm = typeof(RSAPKCS1SignatureFormatter).FullName;
        DeformatterAlgorithm = typeof(RSAPKCS1SignatureDeformatter).FullName;
    }

    public override AsymmetricSignatureDeformatter CreateDeformatter(AsymmetricAlgorithm key)
    {
        var sigProcessor = (AsymmetricSignatureDeformatter)CryptoConfig.CreateFromName(DeformatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA512");
        return sigProcessor;
    }

    public override AsymmetricSignatureFormatter CreateFormatter(AsymmetricAlgorithm key)
    {
        var sigProcessor =
            (AsymmetricSignatureFormatter)CryptoConfig.CreateFromName(FormatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA512");
        return sigProcessor;
    }
}

/// <summary>Declare the signature type for rsa-sha384</summary>
public class RsaPkCs1Sha384SignatureDescription : SignatureDescription {
    public RsaPkCs1Sha384SignatureDescription()
    {
        KeyAlgorithm = typeof(RSACryptoServiceProvider).FullName;
        DigestAlgorithm = typeof(SHA384CryptoServiceProvider).FullName;
        FormatterAlgorithm = typeof(RSAPKCS1SignatureFormatter).FullName;
        DeformatterAlgorithm = typeof(RSAPKCS1SignatureDeformatter).FullName;
    }

    public override AsymmetricSignatureDeformatter CreateDeformatter(AsymmetricAlgorithm key)
    {
        var sigProcessor = (AsymmetricSignatureDeformatter) CryptoConfig.CreateFromName(DeformatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA384");
        return sigProcessor;
    }

    public override AsymmetricSignatureFormatter CreateFormatter(AsymmetricAlgorithm key)
    {
        var sigProcessor =
            (AsymmetricSignatureFormatter)CryptoConfig.CreateFromName(FormatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA384");
        return sigProcessor;
    }
}

/// <summary>Declare the signature type for rsa-sha256</summary>
public class RsaPkCs1Sha256SignatureDescription : SignatureDescription
{
    public RsaPkCs1Sha256SignatureDescription()
    {
        KeyAlgorithm = typeof(RSACryptoServiceProvider).FullName;
        DigestAlgorithm = typeof(SHA256CryptoServiceProvider).FullName;
        FormatterAlgorithm = typeof(RSAPKCS1SignatureFormatter).FullName;
        DeformatterAlgorithm = typeof(RSAPKCS1SignatureDeformatter).FullName;
    }

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

    public override AsymmetricSignatureFormatter CreateFormatter(AsymmetricAlgorithm key)
    {
        var sigProcessor =
            (AsymmetricSignatureFormatter)CryptoConfig.CreateFromName(FormatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA256");
        return sigProcessor;
    }
}

提示：等等。
只需将其更新到.NET framework 4.6.01590或更高版本，它将支持多达SHA-512而无需任何代码更改。
我的印象是，加密算法是受支持的，因为它支持X509Certificate2对象。sig.CheckSignature（…）方法有一个重载，它接受两个参数，X509Certificate2和bool。您是否尝试过使用它并传递证书和true？请注意，从.NET 4.5开始，您不需要安装任何与.NET 4.0和更早版本不同的第三方库。您只需添加对System.Deployment的引用，并调用
System.Security.Cryptography.CryptoConfig.AddAlgorithm（typeof（RSAPKCS1SHA256SignatureDescription），RsaSha256Namespace）在流程中执行一次，之后原始问题中的代码将使用SHA256哈希。另请参见'const string RsaSha256Namespace=“”；`。。。。及。。。。。框架4.6.2解决了这个问题，不需要任何额外的代码。@OllieJones-您是否知道您的代码是否会在以后和以后迁移到目标4.6.2时中断？@StephanG我已顺利迁移到4.6.1。我知道4.6.2不再需要这段代码，因为他们添加了新的哈希。请参阅的X509部分。我还没有证实这一事实。我已经有客户拒绝做出改变，叹息。
/// <summary>Declare the signature type for rsa-sha512</summary>
public class RsaPkCs1Sha512SignatureDescription : SignatureDescription
{
    public RsaPkCs1Sha512SignatureDescription()
    {
        KeyAlgorithm = typeof(RSACryptoServiceProvider).FullName;
        DigestAlgorithm = typeof(SHA512CryptoServiceProvider).FullName;
        FormatterAlgorithm = typeof(RSAPKCS1SignatureFormatter).FullName;
        DeformatterAlgorithm = typeof(RSAPKCS1SignatureDeformatter).FullName;
    }

    public override AsymmetricSignatureDeformatter CreateDeformatter(AsymmetricAlgorithm key)
    {
        var sigProcessor = (AsymmetricSignatureDeformatter)CryptoConfig.CreateFromName(DeformatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA512");
        return sigProcessor;
    }

    public override AsymmetricSignatureFormatter CreateFormatter(AsymmetricAlgorithm key)
    {
        var sigProcessor =
            (AsymmetricSignatureFormatter)CryptoConfig.CreateFromName(FormatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA512");
        return sigProcessor;
    }
}

/// <summary>Declare the signature type for rsa-sha384</summary>
public class RsaPkCs1Sha384SignatureDescription : SignatureDescription {
    public RsaPkCs1Sha384SignatureDescription()
    {
        KeyAlgorithm = typeof(RSACryptoServiceProvider).FullName;
        DigestAlgorithm = typeof(SHA384CryptoServiceProvider).FullName;
        FormatterAlgorithm = typeof(RSAPKCS1SignatureFormatter).FullName;
        DeformatterAlgorithm = typeof(RSAPKCS1SignatureDeformatter).FullName;
    }

    public override AsymmetricSignatureDeformatter CreateDeformatter(AsymmetricAlgorithm key)
    {
        var sigProcessor = (AsymmetricSignatureDeformatter) CryptoConfig.CreateFromName(DeformatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA384");
        return sigProcessor;
    }

    public override AsymmetricSignatureFormatter CreateFormatter(AsymmetricAlgorithm key)
    {
        var sigProcessor =
            (AsymmetricSignatureFormatter)CryptoConfig.CreateFromName(FormatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA384");
        return sigProcessor;
    }
}

/// <summary>Declare the signature type for rsa-sha256</summary>
public class RsaPkCs1Sha256SignatureDescription : SignatureDescription
{
    public RsaPkCs1Sha256SignatureDescription()
    {
        KeyAlgorithm = typeof(RSACryptoServiceProvider).FullName;
        DigestAlgorithm = typeof(SHA256CryptoServiceProvider).FullName;
        FormatterAlgorithm = typeof(RSAPKCS1SignatureFormatter).FullName;
        DeformatterAlgorithm = typeof(RSAPKCS1SignatureDeformatter).FullName;
    }

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

    public override AsymmetricSignatureFormatter CreateFormatter(AsymmetricAlgorithm key)
    {
        var sigProcessor =
            (AsymmetricSignatureFormatter)CryptoConfig.CreateFromName(FormatterAlgorithm);
        sigProcessor.SetKey(key);
        sigProcessor.SetHashAlgorithm("SHA256");
        return sigProcessor;
    }
}

    CryptoConfig.AddAlgorithm(typeof(RsaPkCs1Sha512SignatureDescription),
        "http://www.w3.org/2001/04/xmldsig-more#rsa-sha512");
    CryptoConfig.AddAlgorithm(typeof(RsaPkCs1Sha384SignatureDescription),
        "http://www.w3.org/2001/04/xmldsig-more#rsa-sha384");
    CryptoConfig.AddAlgorithm(typeof(RsaPkCs1Sha256SignatureDescription),
        "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256");