使用 AccountManagement 扩展类时如何设置二进制属性-C#/.NET问题

How to set a binary attribute when using a AccountManagement Extension Class?(使用 AccountManagement 扩展类时如何设置二进制属性?)

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问题描述

我正在使用自定义类以在 Active Directory 中公开一些自定义架构.我正在存储一个二进制 blob，根据项目要求，此数据必须存储在 AD 中，我不能使用外部存储(如果可以的话，我会这样做).

当我创建用户时，它会很好地存储 blob.我也可以很好地检索 blob 并获取我的所有数据.问题是我是否需要更新值并且出现错误

小示例程序:

使用系统；使用 System.DirectoryServices.AccountManagement;命名空间 SandboxConsole40{课程计划{静态无效主(字符串 [] args){使用(var context = new PrincipalContext(ContextType.Domain)){使用 (var clear = ExamplePrincipal.FindByIdentity(context, "example")){如果(清除！= null)清除.删除()；}使用 (var create = new ExamplePrincipal(context, "example", "Password1", false)){创建.保存();}使用 (var set = ExamplePrincipal.FindByIdentity(context, "example")){set.BlobData = 新字节 [] { 0xDE, 0xAD, 0xBE, 0xEF };//这与方法2失败.设置.保存();}使用 (var lookup = ExamplePrincipal.FindByIdentity(context, "example")){Console.WriteLine(BitConverter.ToString(lookup.BlobData));}使用 (var update = ExamplePrincipal.FindByIdentity(context, "example")){update.BlobData = 新字节[] { 0x12, 0x34, 0x56, 0x67 };更新.保存();//此保存失败，方法 1.}}Console.WriteLine("完成");Console.ReadLine();}[目录对象类(用户")][DirectoryRdnPrefix("CN")]类 ExamplePrincipal : UserPrincipal{public ExamplePrincipal(PrincipalContext context) : base(context) { }公共 ExamplePrincipal(PrincipalContext 上下文，字符串 samAccountName，字符串密码，启用 bool):基础(上下文，samAccountName，密码，启用){}public static new ExamplePrincipal FindByIdentity(PrincipalContext context, string identityValue){return (ExamplePrincipal)FindByIdentityWithType(context, typeof(ExamplePrincipal), identityValue);}[DirectoryProperty("vwBlobData")]公共字节[] BlobData{得到{如果(ExtensionGet(vwBlobData").长度！= 1)返回空；return (byte[])ExtensionGet("vwBlobData")[0];}放{//方法一this.ExtensionSet("vwBlobData", value );//方法二//this.ExtensionSet("vwBlobData", new object[] { value});}}}}}如果我使用方法 1，我会在 update.Save() 操作中得到以下异常
<前>System.DirectoryServices.AccountManagement.PrincipalOperationException 未处理HResult=-2146233087Message=指定的目录服务属性或值已经存在.来源=System.DirectoryServices.AccountManagement错误代码=-2147016691堆栈跟踪://剪断内部异常:System.DirectoryServices.DirectoryServicesCOMExceptionHResult=-2147016691Message=指定的目录服务属性或值已经存在.源 = System.DirectoryServices错误代码=-2147016691扩展错误=8321ExtendedErrorMessage=00002081:AtrErr:DSID-030F154F，#1:0: 00002081: DSID-030F154F，问题 1006 (ATT_OR_VALUE_EXISTS)，数据 0，Att 82818fec (vwBlobData)堆栈跟踪://剪断内部异常:如果我使用方法 2，我会从 set.BlobData 调用的 this.ExtensionSet 调用中得到一个异常.
<前>System.ArgumentException 未处理HResult=-2147024809Message=其元素是另一个集合的集合不能由 ExtensionClasses 设置.来源=System.DirectoryServices.AccountManagement堆栈跟踪://剪断内部异常:

<小时>

总结:如果当前未设置该值，我可以设置该值，但如果我想覆盖现有值，则会出现错误.

解决方案

我找到了一个解决方法，首先将值设置为 null，它不再抛出异常.

using (var update = ExamplePrincipal.FindByIdentity(context, "example")){更新.BlobData = null;更新.保存();update.BlobData = 新字节[] { 0x12, 0x34, 0x56, 0x67 };更新.保存();//方法 1 不再失败.}

我将这个问题留待一段时间，看看是否有其他人可以回答是否有适当"的方法来做到这一点.

<小时>

找到了不需要强制保存的第二个解决方法.

[DirectoryProperty("vwBlobData")]公共字节[] BlobData{得到{如果(ExtensionGet(vwBlobData").长度！= 1)返回空；return (byte[])ExtensionGet("vwBlobData")[0];}放{((DirectoryEntry)this.GetUnderlyingObject()).Properties["vwBlobData"].Value = value;}}

通过直接转换到底层对象，您可以直接设置值.我使用 ILSpy 检查并处理 AccountManagement 包装器处理底层对象，因此 GetUnderlyingObject() 调用不需要 Dispose().

<小时>

最佳解决方案

我发现第 2 个解决方法要求对象持续工作，因此我采用了两全其美的方法.这适用于尚未持久化对象、对象为 null 以及对象已有值的情况.

[DirectoryProperty("vwBlobData")]公共字节[] BlobData{得到{如果(ExtensionGet(vwBlobData").长度！= 1)返回空；return (byte[])ExtensionGet("vwBlobData")[0];}放{if(ExtensionGet("vwBlobData").Length == 0)this.ExtensionSet("vwBlobData", 数据);别的((DirectoryEntry)this.GetUnderlyingObject()).Properties["vwBlobData"].Value = 数据；}}

I am using a custom class to expose some custom schema in Active Directory. I am storing a binary blob, per the project requirements this data must be stored in the AD, I can not use a external store (I would if I could).

When I create the user it stores the blob fine. I also can retrieve the blob back out fine too and get all my data. The issue is if I need to update the value and I am getting errors

Small example program:

using System;
using System.DirectoryServices.AccountManagement;

namespace SandboxConsole40
{
    class Program
    {
        static void Main(string[] args)
        {
            using(var context = new PrincipalContext(ContextType.Domain))
            {
                using (var clear = ExamplePrincipal.FindByIdentity(context, "example"))
                {
                    if (clear != null)
                        clear.Delete();
                }

                using (var create = new ExamplePrincipal(context, "example", "Password1", false))
                {
                    create.Save();
                }

                using (var set = ExamplePrincipal.FindByIdentity(context, "example"))
                {
                    set.BlobData = new byte[] { 0xDE, 0xAD, 0xBE, 0xEF }; //This fails with method 2.
                    set.Save();
                }

                using (var lookup = ExamplePrincipal.FindByIdentity(context, "example"))
                {
                    Console.WriteLine(BitConverter.ToString(lookup.BlobData));
                }

                using (var update = ExamplePrincipal.FindByIdentity(context, "example"))
                {
                    update.BlobData = new byte[] { 0x12, 0x34, 0x56, 0x67 };
                    update.Save(); //This save fails with method 1.
                }
            }

            Console.WriteLine("Done");
            Console.ReadLine();
        }

        [DirectoryObjectClass("user")]
        [DirectoryRdnPrefix("CN")]
        class ExamplePrincipal : UserPrincipal
        {
            public ExamplePrincipal(PrincipalContext context) : base(context) { }

            public ExamplePrincipal(PrincipalContext context, string samAccountName, string password, bool enabled)
                : base(context, samAccountName, password, enabled) { }

            public static new ExamplePrincipal FindByIdentity(PrincipalContext context, string identityValue)
            {
                return (ExamplePrincipal)FindByIdentityWithType(context, typeof(ExamplePrincipal), identityValue);
            }

            [DirectoryProperty("vwBlobData")]
            public byte[] BlobData
            {
                get
                {
                    if (ExtensionGet("vwBlobData").Length != 1)
                        return null;

                    return (byte[])ExtensionGet("vwBlobData")[0];
                }
                set
                {
                    //method 1
                    this.ExtensionSet("vwBlobData",  value );

                    //method 2
                    //this.ExtensionSet("vwBlobData", new object[] { value});
                }
            }
        }
    }
}

If I use method 1 I get the following exception on the update.Save() operation

System.DirectoryServices.AccountManagement.PrincipalOperationException was unhandled
  HResult=-2146233087
  Message=The specified directory service attribute or value already exists.

  Source=System.DirectoryServices.AccountManagement
  ErrorCode=-2147016691
  StackTrace:
       //Snip
  InnerException: System.DirectoryServices.DirectoryServicesCOMException
       HResult=-2147016691
       Message=The specified directory service attribute or value already exists.

       Source=System.DirectoryServices
       ErrorCode=-2147016691
       ExtendedError=8321
       ExtendedErrorMessage=00002081: AtrErr: DSID-030F154F, #1:
    0: 00002081: DSID-030F154F, problem 1006 (ATT_OR_VALUE_EXISTS), data 0, Att 82818fec (vwBlobData)

       StackTrace:
            //Snip
       InnerException:

If I use method 2 I get a exception on from the this.ExtensionSet call from the set.BlobData call.

System.ArgumentException was unhandled
  HResult=-2147024809
  Message=Collections whose elements are another collection cannot be set by ExtensionClasses.
  Source=System.DirectoryServices.AccountManagement
  StackTrace:
      //Snip
  InnerException:

In summary: I can set the value if it is currently not set, but if I want to overwrite a existing value I am getting a error.

解决方案

I found a work around, by setting the value to null first it no-longer throws the exception.

using (var update = ExamplePrincipal.FindByIdentity(context, "example"))
{
    update.BlobData = null;
    update.Save();
    update.BlobData = new byte[] { 0x12, 0x34, 0x56, 0x67 };
    update.Save(); //No longer fails with method 1.
}

I am leaving the question open for a bit to see if anyone else can answer if there is a "proper" way to do this.

Found a 2nd work around that does not require forcing a save.

[DirectoryProperty("vwBlobData")]
public byte[] BlobData
{
    get
    {
        if (ExtensionGet("vwBlobData").Length != 1)
            return null;

        return (byte[])ExtensionGet("vwBlobData")[0];
    }
    set
    {
        ((DirectoryEntry)this.GetUnderlyingObject())
                             .Properties["vwBlobData"].Value = value;
    }
}

By casting directly to the underlying object you can set the value directly. I checked using ILSpy and disposing the AccountManagement wrapper disposes the underlying object, so no Dispose() is required for the GetUnderlyingObject() call.

BEST SOLUTION

I found out the 2nd work around required the object to be persisted to work, so I made a best of both worlds approach. This works when you have not yet persisted the object, when the object is null, and when the object has a value already.

[DirectoryProperty("vwBlobData")]
public byte[] BlobData
{
    get
    {
        if (ExtensionGet("vwBlobData").Length != 1)
            return null;

        return (byte[])ExtensionGet("vwBlobData")[0];
    }
    set
    {
        if(ExtensionGet("vwBlobData").Length == 0)
            this.ExtensionSet("vwBlobData", data); 
        else
            ((DirectoryEntry)this.GetUnderlyingObject())
                                 .Properties["vwBlobData"].Value = data;
    }
}

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