如何验证数字XML签名

Question

我想验证文档是否未以任何方式进行修改.

从Java Web服务,我收到以下带有数字XML签名的 Soap响应:

<?xml version="1.0" encoding="UTF-8"?><Envelope xmlns="http://schemas.xmlsoap.org/soap/envelope/"><SOAP-ENV:Header xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">  
<wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" SOAP-ENV:mustUnderstand="1">
<wsse:BinarySecurityToken xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary" ValueType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-x509-token-profile-1.0#X509v3" wsu:Id="CertId-38670273">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</wsse:BinarySecurityToken><ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:SignedInfo>
<ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
<ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1"/>
<ds:Reference URI="#id-32516734">
<ds:Transforms>
<ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
</ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue>Rx5L4j8kF5RVYnC+spUCdvhh5N0=</ds:DigestValue>
</ds:Reference>
<ds:Reference URI="#id-7716709">
<ds:Transforms>
<ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
</ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1"/>
<ds:DigestValue>fFr2j5DoKTgpEvX1Se7gTC55bWM=</ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue>
jG1BaGgNbbk9JCc3R6JsJKY56p++f0+8RM2aL6TGOXS34NAGv48Sp3iAHEAuUt9+JV6w3VDAcFct
no3nCEISa0P4dVWTlPQJue3GVTWnnlcXao95tjukh9o8lIU7vZGgYHBUZLU+jgS6ZcaUlNW4KFUl
AdrPxR5DmJcFyGEtRY2yclqYhnJdnUc+ZBu5eWbRZgbJzR4MgtGsEQcgtftFe2i0CvRbOSe4mt3T
JQzbGY81ssFCnB44vitgjhVLfPd/08amSa5Xn8KRptbNatp2uq1iGXAifJLVup8T0yS0RzaqhCJg
CaHRPFVKFN3WaJcqPZex75KBwSZMZaaJDZW7lQ==
</ds:SignatureValue>
<ds:KeyInfo Id="KeyId-16708261">
<wsse:SecurityTokenReference xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="STRId-32258670"><wsse:Reference URI="#CertId-38670273" ValueType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-x509-token-profile-1.0#X509v3"/></wsse:SecurityTokenReference>
</ds:KeyInfo>
</ds:Signature>
<wsu:Timestamp xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="id-32516734"><wsu:Created>2017-03-31T09:04:40.352Z</wsu:Created><wsu:Expires>2017-03-31T09:09:40.352Z</wsu:Expires></wsu:Timestamp></wsse:Security><wsa:MessageID xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" SOAP-ENV:mustUnderstand="0">uuid:12b93a00-15f1-11e7-af6b-f16d80f418ae</wsa:MessageID><wsa:To xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" SOAP-ENV:mustUnderstand="0">http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous</wsa:To></SOAP-ENV:Header>


<SOAP-ENV:Body xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" wsu:Id="id-7716709">
...
 </SOAP-ENV:Body></Envelope>

我找到了一个有用的示例来验证MSDN上的xml文件:

  ' Verify the signature of an XML file and return the result.
Function VerifyXmlFile(ByVal Name As String) As [Boolean]
    ' Create a new XML document.
    Dim xmlDocument As New XmlDocument()

    ' Format using white spaces.
    xmlDocument.PreserveWhitespace = True

    ' Load the passed XML file into the document. 
    xmlDocument.Load(Name)

    ' Create a new SignedXml object and pass it
    ' the XML document class.
    Dim signedXml As New SignedXml(xmlDocument)

    ' Find the "Signature" node and create a new
    ' XmlNodeList object.
     Dim nodeList As XmlNodeList = xmlDocument.GetElementsByTagName("Signature", "http://www.w3.org/2000/09/xmldsig#")

    ' Load the signature node.
    signedXml.LoadXml(CType(nodeList(0), XmlElement))

    ' Check the signature and return the result.
    Return signedXml.CheckSignature()

End Function

不幸的是,验证总是返回false.我很难理解为什么它不起作用.

---

根据Henk Holterman和Simon Mourier的提议更新1:

 Function VerifyXmlFile(ByVal Name As String) As Boolean

    ' <SOAP-ENV:Envelope ... > ... </SOAP-ENV:Envelope>
    Dim xDoc = XDocument.Load(Name)

    ' <wsse:binarySecurityToken ... > ... </wsse:binarySecurityToken>
    Dim xBinarySecurityToken = xDoc.Root.Descendants().Skip(2).FirstOrDefault

    ' <SOAP-ENV:Body ... > ... </SOAP-ENV:Body>
    Dim xBody = xDoc.Root.Elements().Skip(1).FirstOrDefault
    Dim signedXml = New SignedXml(ToXmlElement(xBody))

    Dim xmlDocument As New XmlDocument()
    xmlDocument.PreserveWhitespace = True
    xmlDocument.Load(Name)

    Dim nodeList = xmlDocument.GetElementsByTagName("Signature", "http://www.w3.org/2000/09/xmldsig#")
    signedXml.LoadXml(CType(nodeList(0), XmlElement))

    Dim byteCert = Encoding.UTF8.GetBytes(xBinarySecurityToken.Value)
    Dim cert = New X509Certificates.X509Certificate2(byteCert)

    Return signedXml.CheckSignature(cert, True)

End Function

Public Shared Function ToXmlElement(xElement As XElement) As XmlElement
    Dim xmlDoc = New XmlDocument() With {.PreserveWhitespace = True}
    xmlDoc.Load(xElement.CreateReader())
    Return xmlDoc.DocumentElement
End Function

通过调用函数CheckSignature()在CryptographicException中导致消息" 格式错误的引用元素 " .

---

根据@SimonMourier和@ lax1089的提议更新2和解决方案

Private Function VerifyXmlfile(Name As String) As Boolean
    CryptoConfig.AddAlgorithm(GetType(MyXmlDsigC14NTransform), "http://www.w3.org/TR/2001/REC-xml-c14n-20010315")

    Dim xmlDocument As New XmlDocument()
    xmlDocument.PreserveWhitespace = True
    xmlDocument.Load(Name)
    MyXmlDsigC14NTransform.document = xmlDocument

    Dim soapBody As XmlElement = xmlDocument.GetElementsByTagName("SOAP-ENV:Body")(0)
    Dim securityToken = xmlDocument.GetElementsByTagName("SOAP-ENV:Header")(0).FirstChild.NextSibling.FirstChild.NextSibling.InnerText

    Dim signedXml = New SignedXmlWithId(soapBody)

    Dim nodeList = xmlDocument.GetElementsByTagName("Signature", "http://www.w3.org/2000/09/xmldsig#")
    signedXml.LoadXml(CType(nodeList(0), XmlElement))

    Dim byteCert = Convert.FromBase64String(securityToken)
    Dim cert = New X509Certificates.X509Certificate2(byteCert)

    Return signedXml.CheckSignature(cert, True)

End Function

从狗耳朵偷来的助手类

Public Class SignedXmlWithId
Inherits SignedXml

Public Sub New(xml As XmlDocument)
    MyBase.New(xml)
End Sub

Public Sub New(xmlElement As XmlElement)
    MyBase.New(xmlElement)
End Sub

Public Overrides Function GetIdElement(doc As XmlDocument, id As String) As XmlElement
    ' check to see if it's a standard ID reference
    Dim idElem As XmlElement = MyBase.GetIdElement(doc, id)

    If idElem Is Nothing Then
        Dim nsManager As New XmlNamespaceManager(doc.NameTable)
        nsManager.AddNamespace("wsu", "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd")

        idElem = TryCast(doc.SelectSingleNode((Convert.ToString("//*[@wsu:Id=""") & id) + """]", nsManager), XmlElement)
    End If

    Return idElem
End Function

End Class

积分给@SimonMourier和@ CarlosLopez-MSFT

Answer 1

实际上这是一个已知且有记录的问题：

.NET 3.5 和 .NET 4.0 之间的规范化实现已更改。

我不知道这是否适用于所有 XML 签名，但根据我所做的测试，它是有效的。

将以下 C14N Transform 类添加到您的项目中：

public class MyXmlDsigC14NTransform: XmlDsigC14NTransform {
  static XmlDocument _document;
  public static XmlDocument document {
    set {
      _document = value;
    }
  }

  public MyXmlDsigC14NTransform() {}

  public override Object GetOutput() {
    return base.GetOutput();
  }

  public override void LoadInnerXml(XmlNodeList nodeList) {
    base.LoadInnerXml(nodeList);
  }

  protected override XmlNodeList GetInnerXml() {
    XmlNodeList nodeList = base.GetInnerXml();
    return nodeList;
  }

  public XmlElement GetXml() {
    return base.GetXml();
  }

  public override void LoadInput(Object obj) {
    int n;
    bool fDefaultNS = true;

    XmlElement element = ((XmlDocument) obj).DocumentElement;

    if (element.Name.Contains("SignedInfo")) {
      XmlNodeList DigestValue = element.GetElementsByTagName("DigestValue", element.NamespaceURI);
      string strHash = DigestValue[0].InnerText;
      XmlNodeList nodeList = _document.GetElementsByTagName(element.Name);

      for (n = 0; n < nodeList.Count; n++) {
        XmlNodeList DigestValue2 = ((XmlElement) nodeList[n]).GetElementsByTagName("DigestValue", ((XmlElement) nodeList[n]).NamespaceURI);
        string strHash2 = DigestValue2[0].InnerText;
        if (strHash == strHash2) break;
      }

      XmlNode node = nodeList[n];

      while (node.ParentNode != null) {
        XmlAttributeCollection attrColl = node.ParentNode.Attributes;
        if (attrColl != null) {
          for (n = 0; n < attrColl.Count; n++) {
            XmlAttribute attr = attrColl[n];
            if (attr.Prefix == "xmlns") {
              element.SetAttribute(attr.Name, attr.Value);
            } else if (attr.Name == "xmlns") {
              if (fDefaultNS) {
                element.SetAttribute(attr.Name, attr.Value);
                fDefaultNS = false;
              }
            }
          }
        }

        node = node.ParentNode;
      }
    }

    base.LoadInput(obj);
  }
}

并使用 CryptoConfig.AddAlgorithm 方法注册该类，如下所示：

CryptoConfig.AddAlgorithm(typeof(MyXmlDsigC14NTransform), "http://www.w3.org/TR/2001/REC-xml-c14n-20010315"); 

var message = new XmlDocument();
message.PreserveWhitespace = true;
message.Load("XmlSig.xml");

MyXmlDsigC14NTransform.document = message; // The transform class needs the xml document

// Validate signature as normal.  

这应该允许您正确验证 XML 签名并解决您的问题。