1. 首先需要在服务中定义一个从 SOAPHeader 派生的类,表示传入 SOAP 标头的数据.
    IssueVision 在中IssueVisionWeb项目(此项目用于发布Web Services)中通过创建CredentialSoapHeader类来实现第一步.

CredentialSoapHeader.cs

using System.Web.Services.Protocols;

namespace IssueVision.Web
{
 public class CredentialSoapHeader : SoapHeader
 {
  private string m_username;
  private string m_password;

  public string Username
  {
   get{ return m_username;}

   set{ m_username = value;}
  }

  public string Password
  {
   get{ return m_password;}

   set{ m_password = value;}
  }
 }
}

   2. 将服务的公共字段声明为该类型,使该SoapHeader在Web Services的公共合同中公开,并在创建代理时可由客户端使用.

    IssueVision的Web Services----IssueVisionServices.asmx如此实现.

IssueVisionServices.asmx代码片断:

public class IssueVisionServices : WebService
 {
  ...
  private CredentialSoapHeader m_credentials;

  // custom SOAP header to pass credentials
  public CredentialSoapHeader Credentials
  {
     get { return m_credentials; }
     set { m_credentials = value; }
  }
  .......
}

    3. 在Web Services使用 SoapHeader 自定义属性定义一组关联的标头,服务中的每个 WebMethod 都可以使用.(默认情况下，标头是必需的，但也可以定义可选标头)

    IssueVisionServices.asmx代码片断:

  ....
  [WebMethod(Description="Returns the lookup tables for IssueVision.")]

[SoapHeader("Credentials")]
  public IVDataSet GetLookupTables()
  {
   SecurityHelper.VerifyCredentials(this);  
   return new IVData().GetLookupTables();
  }

    SecurityHelper类的VerifyCredentials方法用来从Web Services中的SoapHeader类来得到自定义身份验证凭据(如用户名和密码).

  SecurityHelper.cs代码片断如下:

// verifies the clients credentials
  public static void

VerifyCredentials(IssueVisionServices service)
  {
   if (service.Credentials == null || service.Credentials.Username == null || service.Credentials.Password == null )   //如果没有认证信息,返回SoapException,这样就不能匿名调用Web Method了
   {
    EventLogHelper.LogFailureAudit("A login was attempted with missing credential information.");
    throw new SoapException(string.Empty, SoapException.ClientFaultCode, "Security");
   }

    // does the computed hash match the database hash?
    if (string.Compare(dbPasswordHash, passwordHash) != 0)
    {
     EventLogHelper.LogFailureAudit(string.Format("The password for the username {0} was incorrect.", header.Username));
     throw new SoapException(string.Empty, SoapException.ClientFaultCode, "Security");
    }
   }
   
   return dbPasswordHash;
}

  4. 最后客户端在调用要求标头的方法之前，需直接在代理类上设置标头.

  IssueVision 的SmartClient端的WebServicesLayer类来调用此Web Services

  WebServicesLayer.cs程序片断如下:

private static IssueVisionServices GetWebServiceReference(

string username, string password)
  {
   IssueVisionServices dataService = new IssueVisionServices();
   
   //<ReplaceWithWse>
   CredentialSoapHeader header = new CredentialSoapHeader();
   header.Username = username;
   header.Password = password;
   dataService.CredentialSoapHeaderValue = header;
   //</ReplaceWithWse>
   
   InitWebServiceProxy(dataService);
   
   return dataService;
}

   通过以上步骤就可以完成Web Services自定义身份验证了.IssueVision中还有很多相关的操作,因为在这里只是讨论一下SoapHeader的用法,就不在列举了.
   鄙人见识就这么多了,欢迎大家讨论,提出新的看法.

CopyRight © YellowWee 2004. All Right Reserved.