使用独立存储和受保护的数据保存用户凭据

Question

我想以安全的方式保存用户详细信息，所以我的目的是采用一个包含凭据的类，对其进行序列化，使用protectedData对其进行加密，然后将这些新的加密数据保存在独立存储中。我有以下保存方法

    public bool SaveCredentials(ILoginCredentials credentials)
    {
        try
        {
            //CredentialStorage implements ILoginCredentials 
            CredentialStorage storage = new CredentialStorage(credentials);
            byte[] lastEncryptedData = ToByteArray(storage);
            lastEncryptedData = ProtectedData.Protect(lastEncryptedData, AditionalEntropy, DataProtectionScope.CurrentUser);
            IsolatedStorageFile isoStore = IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null);
            IsolatedStorageFileStream isoStream = new IsolatedStorageFileStream("ExternalSSOProvider", FileMode.Create,
                                                                                 FileAccess.Write, isoStore);
            isoStream.Write(lastEncryptedData, 0, lastEncryptedData.Length);
            isoStream.Close();
            return true;
        }
        catch (Exception)
        {
            return false;
        }
    }
    private static byte[] ToByteArray(object source)
    {
        var formatter = new BinaryFormatter();
        using (var stream = new MemoryStream())
        {
            formatter.Serialize(stream, source);
            return stream.ToArray();
        }
    }

这段代码似乎没有问题

然后我有恢复到对象的代码

    private CredentialStorage GetCredentials()
    {
        try
        {
            IsolatedStorageFile isoStore = IsolatedStorageFile.GetStore(IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null);
            if (isoStore.FileExists("ExternalSSOProvider"))
            {
                using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream("ExternalSSOProvider", FileMode.Open, isoStore))
                {
                    using (StreamReader reader = new StreamReader(stream))
                    {
                       using(MemoryStream ms = new MemoryStream())
                       {
                           reader.BaseStream.CopyTo(ms);
                           byte[] protectedMemory = ms.ToArray();
                           ms.Close();
                           ProtectedData.Unprotect(protectedMemory, AditionalEntropy, DataProtectionScope.CurrentUser);
                           return ToCredentials(protectedMemory);
                       }
                    }
                }
            }
        }
        catch (Exception)
        {
            return null;
        }
        return null;
    }
    private static CredentialStorage ToCredentials(byte[] source)
    {
        var formatter = new BinaryFormatter();
        using (var stream = new MemoryStream(source))
        {
            var x = formatter.Deserialize(stream); //My exception occurs here
            return x as CredentialStorage;
        }
    }

当我尝试在 ToCredentials 方法中反序列化对象时，出现以下错误

二进制流 'n' 不包含有效的 BinaryHeader。可能的原因是序列化和反序列化之间的流或对象版本更改无效。

任何帮助将不胜感激！

仅供参考，这是 ILoginCredentials 接口

 public interface ILoginCredentials
 {
     string Username { get; }
     string Password { get; }
 }

Answer 1

好的，

我发现了问题。在 GetCredentials 方法中，我有以下行

    ProtectedData.Unprotect(protectedMemory, AditionalEntropy, DataProtectionScope.CurrentUser); 

我已将其更改为

    protectedMemory = ProtectedData.Unprotect(protectedMemory, AditionalEntropy, DataProtectionScope.CurrentUser); 

因为我从未使用我试图从仍然加密的数据中反序列化的返回值更新受保护的内存变量