关于c＃：如何在.NET中验证RSA-SHA512 XML签名？

How to Verify a RSA-SHA512 XML Signature in .NET?

在有关signedxml的msdn站点的帮助下，我可以轻松地验证XML DSIG是否正确。如果使用签名方法sha1，它就可以完美地工作。

但是，当我收到signaturemethod rsa-sha512(http://www.w3.org/2001/04/xmldsig more rsa-sha512)时，checkSignature()中断，出现一个加密异常：无法为提供的签名算法创建signatureDescription。

似乎checkSignature()无法验证RSA-SHA512签名。

有人知道如何检查这些签名吗？

代码取自msdn站点，是：

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public static bool VerifyXml(XmlDocument doc, bool removeSignatureElement = false)
{
// Check arguments.
if (doc == null)
throw new ArgumentException("doc");

// Create a new SignedXml object and pass it the XML document class.
SignedXml signedXml = new SignedXml(doc);

// Find the"Signature" node and create a new XmlNodeList object.
XmlNodeList nodeList = doc.GetElementsByTagName("Signature", Constants.NamespaceDSig);

// Throw an exception if no signature was found.
if (nodeList.Count < 1)
{
throw new CryptographicException("Verification failed: No Signature was found in the document.");
}

// This example only supports one signature for the entire XML document. Throw an exception if more than one signature was found.
if (nodeList.Count > 1)
{
throw new CryptographicException("Verification failed: More that one signature was found for the document.");
}

// Load the first <signature> node.
signedXml.LoadXml((XmlElement)nodeList[0]);

// Check the signature and return the result.
bool signedCorrectly = signedXml.CheckSignature(); // throws the Exception!!!

return signedCorrectly;
}

签名的XML是：

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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Notification xmlns="http://www.xxxxxxxxxxx.xx/xxxxx">
<xenc:EncryptedData xmlns:xenc="http://www.w3.org/2001/04/xmlenc#" Type="http://www.w3.org/2001/04/xmlenc#Content"> ... </xenc:EncryptedData>
<ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:SignedInfo>
<ds:CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/>
<ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha512"/>
<ds:Reference URI="">
<ds:Transforms>
<ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
<ds:Transform Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments"/>
</ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue>WsHcyNL7Jh8HSzR9ArzTqomBkHs=</ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue>
pWDatSEbypIUVQR9NFmLkB9kKWjMb6rKWGFFvGqT5tOUILeDhMHUqjCRB9v/g6yYdogC9TRWouhz
...VoZAIBs7EqCbLt7RgpB4GHWc9E3qp65NaCgluw==
</ds:SignatureValue>
<ds:KeyInfo>
<ds:X509Data>
<ds:X509Certificate>
MIIG+zCCBOOgAwIBAgIHAe2+sRfTfDANBgkqhkiG9w0BAQUFADCBkTELMAkGA1UEBhMCQVQxDTAL
...tvawqBjOfkw1yeDzsDMJHfMuAcpYfrEL
</ds:X509Certificate>
</ds:X509Data>
</ds:KeyInfo>
</ds:Signature>
</Notification>

相关讨论

您可以验证RSA SHA512签名，但是您必须自己实现和注册签名描述。

签名说明：

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public sealed class RSAPKCS1SHA512SignatureDescription : SignatureDescription
{
public RSAPKCS1SHA512SignatureDescription()
{
KeyAlgorithm = typeof( RSACryptoServiceProvider ).FullName;
DigestAlgorithm = typeof( SHA512Managed ).FullName;
FormatterAlgorithm = typeof( RSAPKCS1SignatureFormatter ).FullName;
DeformatterAlgorithm = typeof( RSAPKCS1SignatureDeformatter ).FullName;
}

public override AsymmetricSignatureDeformatter CreateDeformatter( AsymmetricAlgorithm key )
{
if( key == null )
{
throw new ArgumentNullException("key" );
}

var deformatter = new RSAPKCS1SignatureDeformatter( key );
deformatter.SetHashAlgorithm("SHA512" );
return deformatter;
}

public override AsymmetricSignatureFormatter CreateFormatter( AsymmetricAlgorithm key )
{
if( key == null )
{
throw new ArgumentNullException("key" );
}

var formatter = new RSAPKCS1SignatureFormatter( key );
formatter.SetHashAlgorithm("SHA512" );
return formatter;
}
}

在代码中，您必须用cryptoconfig注册此描述：

1 2	const string XmlDsigRsaSha512 ="http://www.w3.org/2001/04/xmldsig-more#rsa-sha512"; CryptoConfig.AddAlgorithm( typeof( RSAPKCS1SHA512SignatureDescription ), XmlDsigRsaSha512 );

我在Windows7 64位上用.NET 4.0测试了它。

根据我的研究，SignedXml实现只支持以下签名方法：

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http://www.w3.org/2000/09/xmldsig#hmac-sha1
http://www.w3.org/2001/04/xmldsig-more#hmac-sha256
http://www.w3.org/2001/04/xmldsig-more#hmac-sha384
http://www.w3.org/2001/04/xmldsig-more#hmac-sha512
http://www.w3.org/2001/04/xmldsig-more#hmac-md5
http://www.w3.org/2001/04/xmldsig-more#hmac-ripemd160

这些可用于签名和验证。不幸的是，

1	http://www.w3.org/2001/04/xmldsig-more#rsa-sha512

不支持用作签名算法。

最终，所有的加密方法都会下降到CryptoConfig.CreateFromName，其中rsa-sha512返回空值。

编辑：我可能刚刚找到了一个让它工作的方法。以下代码段对我有用：

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Dictionary<string, object> ht =
(Dictionary<string, object>)typeof( CryptoConfig ).InvokeMember(
"DefaultNameHT", System.Reflection.BindingFlags.GetProperty |
System.Reflection.BindingFlags.Static |
System.Reflection.BindingFlags.NonPublic, null, typeof( CryptoConfig ),
null );

var o = ht["http://www.w3.org/2000/09/xmldsig#rsa-sha1"];
ht["http://www.w3.org/2001/04/xmldsig-more#rsa-sha512"] = o;

这应该在您签名/验证之前调用。

这是基于观察到实际散列验证来自证书，算法名称仅用作保护。如果您欺骗配置认为RSA-SHA512是受支持的(通过指向同一个未使用的RSA-SHA1格式化程序)，事情就会开始工作。

编辑2：在进一步调查涉及咨询来源后

http://www.dotnetframework.org/default.aspx/4@0/4@0/untmp/devdiv_tfs/dev10/releases/rtmrel/ndp/clr/src/managedlibraries/security/system/security/cryptography/xml/signedxml@cs/1305376/signedxml@cs

我认为上述解决方案行不通。它所做的只是更改已签名文档中的签名名，但是不幸的是，仍然使用RSA-SHA1计算签名。

唯一可行的方法是将RSA-SHA512作为KeyedHashAlgoritm来实现，因为签名和验证似乎都支持重载版本：

1 2	signedXml.ComputeSignature( KeyedHashAlgorithm hash ); signedXml.CheckSignature( KeyedHashAlgorithm hash );