SignedXml.CheckSignatureReturningKey(AsymmetricAlgorithm) 方法
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
确定属性是否 Signature 使用签名中的公钥进行验证。
public:
bool CheckSignatureReturningKey([Runtime::InteropServices::Out] System::Security::Cryptography::AsymmetricAlgorithm ^ % signingKey);public bool CheckSignatureReturningKey(out System.Security.Cryptography.AsymmetricAlgorithm? signingKey);public bool CheckSignatureReturningKey(out System.Security.Cryptography.AsymmetricAlgorithm signingKey);member this.CheckSignatureReturningKey : AsymmetricAlgorithm -> boolPublic Function CheckSignatureReturningKey (ByRef signingKey As AsymmetricAlgorithm) As Boolean参数
- signingKey
- AsymmetricAlgorithm
此方法返回时，包含该实现 AsymmetricAlgorithm 将公钥保存在签名中。 此参数未初始化传递。
返回
true 如果属性使用签名中的公钥进行验证，则为 Signature ;否则为 false。
例外
参数 signingKey 为 null。
示例
下面的代码示例演示如何对 XML 文档进行签名、使用 CheckSignatureReturningKey验证签名，然后确认返回的密钥是否与应用程序已信任的密钥匹配。
//
// This example signs an XML file using an
// envelope signature. It then verifies the
// signed XML.
//
using System;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;
using System.Text;
using System.Xml;
public class SignVerifyEnvelope
{
public static void Main(String[] args)
{
try
{
// Generate a RSA signing key.
RSA RSAKey = RSA.Create();
// Create an XML file to sign.
CreateSomeXml("Example.xml");
Console.WriteLine("New XML file created.");
// Sign the XML that was just created and save it in a
// new file.
SignXmlFile("Example.xml", "SignedExample.xml", RSAKey);
Console.WriteLine("XML file signed.");
// Verify the signature of the signed XML.
Console.WriteLine("Verifying signature...");
bool result = VerifyXmlFile("SignedExample.xml");
// Display the results of the signature verification to \
// the console.
if(result)
{
Console.WriteLine("The XML signature is valid.");
}
else
{
Console.WriteLine("The XML signature is not valid.");
}
}
catch(CryptographicException e)
{
Console.WriteLine(e.Message);
}
}
// Sign an XML file and save the signature in a new file.
public static void SignXmlFile(string FileName, string SignedFileName, RSA RSAKey)
{
// Create a new XML document.
XmlDocument doc = new XmlDocument();
// Format the document to ignore white spaces.
doc.PreserveWhitespace = false;
// Load the passed XML file using it's name.
doc.Load(new XmlTextReader(FileName));
// Create a SignedXml object.
SignedXml signedXml = new SignedXml(doc);
// Add the RSA key to the SignedXml document.
signedXml.SigningKey = RSAKey;
// Create a reference to be signed.
Reference reference = new Reference();
reference.Uri = "";
// Add an enveloped transformation to the reference.
XmlDsigEnvelopedSignatureTransform env = new XmlDsigEnvelopedSignatureTransform();
reference.AddTransform(env);
// Add the reference to the SignedXml object.
signedXml.AddReference(reference);
// Add a RSAKeyValue to the KeyInfo (optional; helps recipient find key to validate).
KeyInfo keyInfo = new KeyInfo();
keyInfo.AddClause(new RSAKeyValue((RSA)RSAKey));
signedXml.KeyInfo = keyInfo;
// Compute the signature.
signedXml.ComputeSignature();
// Get the XML representation of the signature and save
// it to an XmlElement object.
XmlElement xmlDigitalSignature = signedXml.GetXml();
// Append the element to the XML document.
doc.DocumentElement.AppendChild(doc.ImportNode(xmlDigitalSignature, true));
if (doc.FirstChild is XmlDeclaration)
{
doc.RemoveChild(doc.FirstChild);
}
// Save the signed XML document to a file specified
// using the passed string.
XmlTextWriter xmltw = new XmlTextWriter(SignedFileName, new UTF8Encoding(false));
doc.WriteTo(xmltw);
xmltw.Close();
}
// Verify the signature of an XML file and return the result.
public static Boolean VerifyXmlFile(String Name)
{
// Create a new XML document.
XmlDocument xmlDocument = 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.
SignedXml signedXml = new SignedXml(xmlDocument);
// Find the "Signature" node and create a new
// XmlNodeList object.
XmlNodeList nodeList = xmlDocument.GetElementsByTagName("Signature");
// Load the signature node.
signedXml.LoadXml((XmlElement)nodeList[0]);
// Check the signature and return the result.
return signedXml.CheckSignature();
}
// Create example data to sign.
public static void CreateSomeXml(string FileName)
{
// Create a new XmlDocument object.
XmlDocument document = new XmlDocument();
// Create a new XmlNode object.
XmlNode node = document.CreateNode(XmlNodeType.Element, "", "MyElement", "samples");
// Add some text to the node.
node.InnerText = "Example text to be signed.";
// Append the node to the document.
document.AppendChild(node);
// Save the XML document to the file name specified.
XmlTextWriter xmltw = new XmlTextWriter(FileName, new UTF8Encoding(false));
document.WriteTo(xmltw);
xmltw.Close();
}
}
'
' This example signs an XML file using an
' envelope signature. It then verifies the
' signed XML.
'
Imports System.Security.Cryptography
Imports System.Security.Cryptography.Xml
Imports System.Text
Imports System.Xml
Public Class SignVerifyEnvelope
Overloads Public Shared Sub Main(args() As [String])
Try
' Generate a RSA signing key.
Dim RSAKey As RSA = RSA.Create()
' Create an XML file to sign.
CreateSomeXml("Example.xml")
Console.WriteLine("New XML file created.")
' Sign the XML that was just created and save it in a
' new file.
SignXmlFile("Example.xml", "SignedExample.xml", RSAKey)
Console.WriteLine("XML file signed.")
' Verify the signature of the signed XML.
Console.WriteLine("Verifying signature...")
Dim result As Boolean = VerifyXmlFile("SignedExample.xml")
' Display the results of the signature verification to \
' the console.
If result Then
Console.WriteLine("The XML signature is valid.")
Else
Console.WriteLine("The XML signature is not valid.")
End If
Catch e As CryptographicException
Console.WriteLine(e.Message)
End Try
End Sub
' Sign an XML file and save the signature in a new file.
Public Shared Sub SignXmlFile(FileName As String, SignedFileName As String, RSAKey As RSA)
' Create a new XML document.
Dim doc As New XmlDocument()
' Format the document to ignore white spaces.
doc.PreserveWhitespace = False
' Load the passed XML file using it's name.
doc.Load(New XmlTextReader(FileName))
' Create a SignedXml object.
Dim signedXml As New SignedXml(doc)
' Add the RSA key to the SignedXml document.
signedXml.SigningKey = RSAKey
' Create a reference to be signed.
Dim reference As New Reference()
reference.Uri = ""
' Add an enveloped transformation to the reference.
Dim env As New XmlDsigEnvelopedSignatureTransform()
reference.AddTransform(env)
' Add the reference to the SignedXml object.
signedXml.AddReference(reference)
' Add a RSAKeyValue to the KeyInfo (optional; helps recipient find key to validate).
Dim keyInfo As New KeyInfo()
keyInfo.AddClause(New RSAKeyValue(CType(RSAKey, RSA)))
signedXml.KeyInfo = keyInfo
' Compute the signature.
signedXml.ComputeSignature()
' Get the XML representation of the signature and save
' it to an XmlElement object.
Dim xmlDigitalSignature As XmlElement = signedXml.GetXml()
' Append the element to the XML document.
doc.DocumentElement.AppendChild(doc.ImportNode(xmlDigitalSignature, True))
If TypeOf doc.FirstChild Is XmlDeclaration Then
doc.RemoveChild(doc.FirstChild)
End If
' Save the signed XML document to a file specified
' using the passed string.
Dim xmltw As New XmlTextWriter(SignedFileName, New UTF8Encoding(False))
doc.WriteTo(xmltw)
xmltw.Close()
End Sub
' Verify the signature of an XML file and return the result.
Public Shared Function VerifyXmlFile(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")
' Load the signature node.
signedXml.LoadXml(CType(nodeList(0), XmlElement))
' Check the signature and return the result.
Return signedXml.CheckSignature()
End Function
' Create example data to sign.
Public Shared Sub CreateSomeXml(FileName As String)
' Create a new XmlDocument object.
Dim document As New XmlDocument()
' Create a new XmlNode object.
Dim node As XmlNode = document.CreateNode(XmlNodeType.Element, "", "MyElement", "samples")
' Add some text to the node.
node.InnerText = "Example text to be signed."
' Append the node to the document.
document.AppendChild(node)
' Save the XML document to the file name specified.
Dim xmltw As New XmlTextWriter(FileName, New UTF8Encoding(False))
document.WriteTo(xmltw)
xmltw.Close()
End Sub
End Class
注解
Important
返回 signingKey 的键基于 KeyInfo 已签名文档的元素进行选择，该元素由生成文档的人员控制。 结果 true 仅证明文档的已签名部分与返回的密钥计算的签名匹配，而不是密钥属于受信任的签名者。 此重载不适用于从不受信任的源对文档进行身份验证，除非调用方将应用程序在将文档视为真实之前已信任的键进行比较 signingKey 。
对于大多数方案，首选先获取验证密钥的重载，以便在验证之前建立信任：
有关其他指南，请参阅课堂页上的 “备注 ”部分。
