public sealed class XmlKeyManager : IKeyManager, IInternalXmlKeyManager
{
 public XmlKeyManager(IXmlRepository repository, IAuthenticatedEncryptorConfiguration configuration, IServiceProvider services);

 public IKey CreateNewKey(DateTimeOffset activationDate, DateTimeOffset expirationDate);
 public IReadOnlyCollection<IKey> GetAllKeys();
 public CancellationToken GetCacheExpirationToken();
 public void RevokeAllKeys(DateTimeOffset revocationDate, string reason = null);
 public void RevokeKey(Guid keyId, string reason = null);
} 

 public void ConfigureServices(IServiceCollection services) 
{
 services.AddDataProtection();

 services.AddDataProtection(DataProtectionOptions option);
}

//===========擴展方法如下：

public static class DataProtectionServiceCollectionExtensions
{
 public static IDataProtectionBuilder AddDataProtection(this IServiceCollection services);
 
 //具有可傳遞參數(shù)的重載，在集群環(huán)境中需要使用此項配置
 public static IDataProtectionBuilder AddDataProtection(this IServiceCollection services, Action<DataProtectionOptions> setupAction);
}

// DataProtectionOptions 屬性：
public class DataProtectionOptions
{
 public string ApplicationDiscriminator { get; set; }
} 

 public void ConfigureServices(IServiceCollection services) 
{
 services.AddDataProtection()
 
 //windows dpaip 作為主加密鍵
 .ProtectKeysWithDpapi()
 
 //如果是 windows 8+ 或者windows server2012+ 可以使用此選項（基于Windows DPAPI-NG）
 .ProtectKeysWithDpapiNG("SID={current account SID}", DpapiNGProtectionDescriptorFlags.None)
 
 //如果是 windows 8+ 或者windows server2012+ 可以使用此選項（基于證書）
 .ProtectKeysWithDpapiNG("CERTIFICATE=HashId:3BCE558E2AD3E0E34A7743EAB5AEA2A9BD2575A0", DpapiNGProtectionDescriptorFlags.None)
 
 //使用證書作為主加密鍵，目前只有widnows支持，linux還不支持。
 .ProtectKeysWithCertificate();
} 

 public void ConfigureServices(IServiceCollection services) 
{
 services.AddDataProtection()
 //windows、Linux、macOS 下可以使用此種方式 保存到文件系統(tǒng)
 .PersistKeysToFileSystem(new System.IO.DirectoryInfo("C:\\share_keys\\"))
 //windows 下可以使用此種方式 保存到注冊表
 .PersistKeysToRegistry(Microsoft.Win32.RegistryKey.FromHandle(null)) 
} 

 public class RedisXmlRepository : IXmlRepository, IDisposable
{

 public static readonly string RedisHashKey = "DataProtectionXmlRepository";
 
 private IConnectionMultiplexer _connection;
 
 private bool _disposed = false;
 
 public RedisXmlRepository(string connectionString, ILogger<RedisXmlRepository> logger)
  : this(ConnectionMultiplexer.Connect(connectionString), logger)
 {
 }
 
 public RedisXmlRepository(IConnectionMultiplexer connection, ILogger<RedisXmlRepository> logger)
 {
  if (connection == null)
  {
   throw new ArgumentNullException(nameof(connection));
  }
 
  if (logger == null)
  {
   throw new ArgumentNullException(nameof(logger));
  }
 
  this._connection = connection;
  this.Logger = logger;
 
  var configuration = Regex.Replace(this._connection.Configuration, @"password\s*=\s*[^,]*", "password=****", RegexOptions.IgnoreCase);
  this.Logger.LogDebug("Storing data protection keys in Redis: {RedisConfiguration}", configuration);
 }
 
 public ILogger<RedisXmlRepository> Logger { get; private set; }
 
 public void Dispose()
 {
  this.Dispose(true);
 }
 public IReadOnlyCollection<XElement> GetAllElements()
 {
  var database = this._connection.GetDatabase();
  var hash = database.HashGetAll(RedisHashKey);
  var elements = new List<XElement>();
 
  if (hash == null || hash.Length == 0)
  {
   return elements.AsReadOnly();
  }
 
  foreach (var item in hash.ToStringDictionary())
  {
   elements.Add(XElement.Parse(item.Value));
  }
 
  this.Logger.LogDebug("Read {XmlElementCount} XML elements from Redis.", elements.Count);
  return elements.AsReadOnly();
 }
 
 public void StoreElement(XElement element, string friendlyName)
 {
  if (element == null)
  {
   throw new ArgumentNullException(nameof(element));
  }
 
  if (string.IsNullOrEmpty(friendlyName))
  {
   friendlyName = Guid.NewGuid().ToString();
  }
 
  this.Logger.LogDebug("Storing XML element with friendly name {XmlElementFriendlyName}.", friendlyName);
 
  this._connection.GetDatabase().HashSet(RedisHashKey, friendlyName, element.ToString());
 }
 protected virtual void Dispose(bool disposing)
 {
  if (!this._disposed)
  {
   if (disposing)
   {
    if (this._connection != null)
    {
     this._connection.Close();
     this._connection.Dispose();
    }
   }
 
   this._connection = null;
   this._disposed = true;
  }
 }
} 

 public static IDataProtectionBuilder PersistKeysToRedis(this IDataProtectionBuilder builder, string redisConnectionString)
{
 if (builder == null)
 {
  throw new ArgumentNullException(nameof(builder));
 }

 if (redisConnectionString == null)
 {
  throw new ArgumentNullException(nameof(redisConnectionString));
 }

 if (redisConnectionString.Length == 0)
 {
  throw new ArgumentException("Redis connection string may not be empty.", nameof(redisConnectionString));
 }
 
 //因為在services.AddDataProtection()的時候，已經(jīng)注入了IXmlRepository，所以應該先移除掉
 //此處應該封裝成為一個方法來調(diào)用，為了讀者好理解，我就直接寫了
 for (int i = builder.Services.Count - 1; i >= 0; i--)
 {
  if (builder.Services[i]?.ServiceType == descriptor.ServiceType)
  {
   builder.Services.RemoveAt(i);
  }
 }

  var descriptor = ServiceDescriptor.Singleton<IXmlRepository>(services => new RedisXmlRepository(redisConnectionString, services.GetRequiredService<ILogger<RedisXmlRepository>>()))
  
  builder.Services.Add(descriptor);
  
  return builder.Use();
} 

 public void ConfigureServices(IServiceCollection services) 
{
 services.AddDataProtection()
 
 // ================以下是唯一標識==============
 
 //設置應用程序唯一標識
 .SetApplicationName("my_app_sample_identity");
 
 
 // =============以下是主加密鍵===============
 
 //windows dpaip 作為主加密鍵
 .ProtectKeysWithDpapi()
 
 //如果是 windows 8+ 或者windows server2012+ 可以使用此選項（基于Windows DPAPI-NG）
 .ProtectKeysWithDpapiNG("SID={current account SID}", DpapiNGProtectionDescriptorFlags.None)
 
 //如果是 windows 8+ 或者windows server2012+ 可以使用此選項（基于證書）
 .ProtectKeysWithDpapiNG("CERTIFICATE=HashId:3BCE558E2AD3E0E34A7743EAB5AEA2A9BD2575A0", DpapiNGProtectionDescriptorFlags.None)
 
 //使用證書作為主加密鍵，目前只有widnows支持，linux還不支持。
 .ProtectKeysWithCertificate();
 
 
 // ==============以下是存儲位置=================
 
 //windows、Linux、macOS 下可以使用此種方式 保存到文件系統(tǒng)
 .PersistKeysToFileSystem(new System.IO.DirectoryInfo("C:\\share_keys\\"))
 
 //windows 下可以使用此種方式 保存到注冊表
 .PersistKeysToRegistry(Microsoft.Win32.RegistryKey.FromHandle(null)) 
 
  // 存儲到redis
 .PersistKeysToRedis(Configuration.Section["RedisConnection"])
}