ASP.NET Core 中的加密配置

Encrypted configuration in ASP.NET Core

随着 web.config 的消失,在使用 ASP.NET Core 构建的 Web 应用程序的配置中存储敏感信息(密码、令牌)的首选方式是什么?

有没有办法自动获取 appsettings.json 中的加密配置部分?

用户机密看起来是一个很好的存储密码的解决方案,而且通常是应用程序机密,至少在开发期间

检查 official Microsoft documentation. You can also review 其他 SO 问题。

这只是一种在开发过程中“隐藏”您的秘密并避免将它们泄露到源代码树中的方法; Secret Manager 工具不会加密存储的秘密,不应将其视为受信任的存储。

如果您想将加密的 appsettings.json 投入生产,您可以通过构建 custom configuration provider.

例如:

public class CustomConfigProvider : ConfigurationProvider, IConfigurationSource
{
    public CustomConfigProvider()
    {
    }

    public override void Load()
    {
        Data = UnencryptMyConfiguration();
    }

    private IDictionary<string, string> UnencryptMyConfiguration()
    {
        // do whatever you need to do here, for example load the file and unencrypt key by key
        //Like:
       var configValues = new Dictionary<string, string>
       {
            {"key1", "unencryptedValue1"},
            {"key2", "unencryptedValue2"}
       };
       return configValues;
    }

    private IDictionary<string, string> CreateAndSaveDefaultValues(IDictionary<string, string> defaultDictionary)
    {
        var configValues = new Dictionary<string, string>
        {
            {"key1", "encryptedValue1"},
            {"key2", "encryptedValue2"}
        };
        return configValues;                
    }

    public IConfigurationProvider Build(IConfigurationBuilder builder)
    {
       return new CustomConfigProvider();
    }
}

为您的扩展方法定义静态 class:

public static class CustomConfigProviderExtensions
{              
        public static IConfigurationBuilder AddEncryptedProvider(this IConfigurationBuilder builder)
        {
            return builder.Add(new CustomConfigProvider());
        }
}

然后就可以激活了:

// Set up configuration sources.
var builder = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json")
    .AddEncryptedProvider()
    .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true);

我不想编写自定义提供程序 – 工作量太大。我只是想利用 JsonConfigurationProvider,所以我想出了一种适合我的方法,希望它能帮助别人。

public class JsonConfigurationProvider2 : JsonConfigurationProvider
{
    public JsonConfigurationProvider2(JsonConfigurationSource2 source) : base(source)
    {
    }

    public override void Load(Stream stream)
    {
        // Let the base class do the heavy lifting.
        base.Load(stream);

        // Do decryption here, you can tap into the Data property like so:

         Data["abc:password"] = MyEncryptionLibrary.Decrypt(Data["abc:password"]);

        // But you have to make your own MyEncryptionLibrary, not included here
    }
}

public class JsonConfigurationSource2 : JsonConfigurationSource
{
    public override IConfigurationProvider Build(IConfigurationBuilder builder)
    {
        EnsureDefaults(builder);
        return new JsonConfigurationProvider2(this);
    }
}

public static class JsonConfigurationExtensions2
{
    public static IConfigurationBuilder AddJsonFile2(this IConfigurationBuilder builder, string path, bool optional,
        bool reloadOnChange)
    {
        if (builder == null)
        {
            throw new ArgumentNullException(nameof(builder));
        }
        if (string.IsNullOrEmpty(path))
        {
            throw new ArgumentException("File path must be a non-empty string.");
        }

        var source = new JsonConfigurationSource2
        {
            FileProvider = null,
            Path = path,
            Optional = optional,
            ReloadOnChange = reloadOnChange
        };

        source.ResolveFileProvider();
        builder.Add(source);
        return builder;
    }
}

我同意@CoderSteve 的观点,即编写一个全新的提供程序工作量太大。它也不建立在现有标准 JSON 架构之上。这是我在标准 JSON 架构之上构建的解决方案,使用首选的 .Net Core 加密库,并且非常 DI 友好。

public static class IServiceCollectionExtensions
{
    public static IServiceCollection AddProtectedConfiguration(this IServiceCollection services)
    {
        services
            .AddDataProtection()
            .PersistKeysToFileSystem(new DirectoryInfo(@"c:\keys"))
            .ProtectKeysWithDpapi();

        return services;
    }

    public static IServiceCollection ConfigureProtected<TOptions>(this IServiceCollection services, IConfigurationSection section) where TOptions: class, new()
    {
        return services.AddSingleton(provider =>
        {
            var dataProtectionProvider = provider.GetRequiredService<IDataProtectionProvider>();
            section = new ProtectedConfigurationSection(dataProtectionProvider, section);

            var options = section.Get<TOptions>();
            return Options.Create(options);
        });
    }

    private class ProtectedConfigurationSection : IConfigurationSection
    {
        private readonly IDataProtectionProvider _dataProtectionProvider;
        private readonly IConfigurationSection _section;
        private readonly Lazy<IDataProtector> _protector;

        public ProtectedConfigurationSection(
            IDataProtectionProvider dataProtectionProvider,
            IConfigurationSection section)
        {
            _dataProtectionProvider = dataProtectionProvider;
            _section = section;

            _protector = new Lazy<IDataProtector>(() => dataProtectionProvider.CreateProtector(section.Path));
        }

        public IConfigurationSection GetSection(string key)
        {
            return new ProtectedConfigurationSection(_dataProtectionProvider, _section.GetSection(key));
        }

        public IEnumerable<IConfigurationSection> GetChildren()
        {
            return _section.GetChildren()
                .Select(x => new ProtectedConfigurationSection(_dataProtectionProvider, x));
        }

        public IChangeToken GetReloadToken()
        {
            return _section.GetReloadToken();
        }

        public string this[string key]
        {
            get => GetProtectedValue(_section[key]);
            set => _section[key] = _protector.Value.Protect(value);
        }

        public string Key => _section.Key;
        public string Path => _section.Path;

        public string Value
        {
            get => GetProtectedValue(_section.Value);
            set => _section.Value = _protector.Value.Protect(value);
        }

        private string GetProtectedValue(string value)
        {
            if (value == null)
                return null;

            return _protector.Value.Unprotect(value);
        }
    }
}

像这样连接受保护的配置部分:

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

    // Configure normal config settings
    services.Configure<MySettings>(Configuration.GetSection("MySettings"));

    // Configure protected config settings
    services.AddProtectedConfiguration();
    services.ConfigureProtected<MyProtectedSettings>(Configuration.GetSection("MyProtectedSettings"));
}

您可以使用这样的控制器轻松地为您的配置文件创建加密值:

[Route("encrypt"), HttpGet, HttpPost]
public string Encrypt(string section, string value)
{
    var protector = _dataProtectionProvider.CreateProtector(section);
    return protector.Protect(value);
}

用法: http://localhost/cryptography/encrypt?section=SectionName:KeyName&value=PlainTextValue

public static IServiceCollection ConfigureProtected<TOptions>(this IServiceCollection services, IConfigurationSection section) where TOptions: class, new()
{
    return services.AddSingleton(provider =>
    {
        var dataProtectionProvider = provider.GetRequiredService<IDataProtectionProvider>();
        var protectedSection = new ProtectedConfigurationSection(dataProtectionProvider, section);

        var options = protectedSection.Get<TOptions>();
        return Options.Create(options);
    });
}

这个方法是正确的

只是一些有助于避免问题的说明。当你加密一个值时,它使用的部分是 'Purpose' (https://docs.microsoft.com/en-us/aspnet/core/security/data-protection/consumer-apis/purpose-strings?view=aspnetcore-2.2) 当你得到 'Payload not valid' 或类似的东西时,你加密它的目的可能与目的用于解密它。因此,假设我的 appsettings.json 中有一个名为 'SecureSettings' 的第一级部分,其中有一个连接字符串:

{
"SecureSettings": 
  {
    "ConnectionString":"MyClearTextConnectionString"
  }
}

要加密值,我会调用:http://localhost/cryptography/encrypt?section=SecureSettings:ConnectionString&value=MyClearTextConnectionString

顺便说一句,您可能不想在应用程序本身中保留加密控制器。

我设法创建了一个自定义 JSON 配置提供程序,它使用 DPAPI 来加密和解密机密。它基本上使用您可以定义的简单正则表达式来指定 JSON 的哪些部分需要加密。

执行以下步骤:

  1. Json 文件已加载
  2. 确定匹配给定正则表达式的 JSON 部分是否已经加密(或未加密)。这是通过对 JSON 部分进行 base-64 解码并验证它是否以预期前缀 !ENC!)
  3. 开头来完成的
  4. 如果没有加密,那么先用DPAPI加密JSON部分,然后加上前缀!ENC!编码成base-64
  5. 用 Json 文件中的加密(base-64)值覆盖未加密的 JSON 部分

Note that the base-64 does not bring better security, but only hides the prefix !ENC! for cosmetic reasons. This is just a matter of taste of course ;)

此解决方案包含以下 classes:

  1. 受保护JsonConfigurationProvider class(=自定义JsonConfigurationProvider)
  2. 受保护JsonConfigurationSource class(=自定义JsonConfigurationSource)
  3. AddProtectedJsonFile() IConfigurationBuilder 上的扩展方法,以便简单地添加受保护的配置

假设以下初始 authentication.json 文件:

{
    "authentication": {
        "credentials": [
            {
                user: "john",
                password: "just a password"
            },
            {
                user: "jane",
                password: "just a password"
            }
        ]
    }
}

加载后变成(某种)以下内容

{
    "authentication": {
        "credentials": [
            {
                "user": "john",
                "password": "IUVOQyEBAAAA0Iyd3wEV0R=="
            },
            {
                "user": "jane",
                "password": "IUVOQyEBAAAA0Iyd3wEV0R=="
            }
        ]
    }
}

并假设以下配置class基于json格式

public class AuthenticationConfiguration
{
    [JsonProperty("credentials")]
    public Collection<CredentialConfiguration> Credentials { get; set; }
}

public class CredentialConfiguration
{
    [JsonProperty("user")]
    public string User { get; set; }
    [JsonProperty("password")]
    public string Password { get; set; }
}

示例代码如下:

//Note that the regular expression will cause the authentication.credentials.password path to be encrypted.
//Also note that the byte[] contains the entropy to increase security
var configurationBuilder = new ConfigurationBuilder()
    .AddProtectedJsonFile("authentication.json", true, new byte[] { 9, 4, 5, 6, 2, 8, 1 },
        new Regex("authentication:credentials:[0-9]*:password"));

var configuration = configurationBuilder.Build();
var authenticationConfiguration = configuration.GetSection("authentication").Get<AuthenticationConfiguration>();

//Get the decrypted password from the encrypted JSON file.
//Note that the ProtectedJsonConfigurationProvider.TryGet() method is called (I didn't expect that :D!)
var password = authenticationConfiguration.Credentials.First().Password

Install the Microsoft.Extensions.Configuration.Binder package in order to get the configuration.GetSection("authentication").Get<T>() implementation

最后是魔法发生的 classes :)

/// <summary>Represents a <see cref="ProtectedJsonConfigurationProvider"/> source</summary>
public class ProtectedJsonConfigurationSource : JsonConfigurationSource
{
    /// <summary>Gets the byte array to increse protection</summary>
    internal byte[] Entropy { get; private set; }

    /// <summary>Represents a <see cref="ProtectedJsonConfigurationProvider"/> source</summary>
    /// <param name="entropy">Byte array to increase protection</param>
    /// <exception cref="ArgumentNullException"/>
    public ProtectedJsonConfigurationSource(byte[] entropy)
    {
        this.Entropy = entropy ?? throw new ArgumentNullException(Localization.EntropyNotSpecifiedError);
    }

    /// <summary>Builds the configuration provider</summary>
    /// <param name="builder">Builder to build in</param>
    /// <returns>Returns the configuration provider</returns>
    public override IConfigurationProvider Build(IConfigurationBuilder builder)
    {
        EnsureDefaults(builder);
        return new ProtectedJsonConfigurationProvider(this);
    }

    /// <summary>Gets or sets the protection scope of the configuration provider. Default value is <see cref="DataProtectionScope.CurrentUser"/></summary>
    public DataProtectionScope Scope { get; set; }
    /// <summary>Gets or sets the regular expressions that must match the keys to encrypt</summary>
    public IEnumerable<Regex> EncryptedKeyExpressions { get; set; }
}

/// <summary>Represents a provider that protects a JSON configuration file</summary>
public partial class ProtectedJsonConfigurationProvider : JsonConfigurationProvider
{
    private readonly ProtectedJsonConfigurationSource protectedSource;
    private readonly HashSet<string> encryptedKeys = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
    private static readonly byte[] encryptedPrefixBytes = Encoding.UTF8.GetBytes("!ENC!");

    /// <summary>Checks whether the given text is encrypted</summary>
    /// <param name="text">Text to check</param>
    /// <returns>Returns true in case the text is encrypted</returns>
    private bool isEncrypted(string text)
    {
        if (text == null) { return false; }

        //Decode the data in order to verify whether the decoded data starts with the expected prefix
        byte[] decodedBytes;
        try { decodedBytes = Convert.FromBase64String(text); }
        catch (FormatException) { return false; }

        return decodedBytes.Length >= encryptedPrefixBytes.Length
            && decodedBytes.AsSpan(0, encryptedPrefixBytes.Length).SequenceEqual(encryptedPrefixBytes);
    }

    /// <summary>Converts the given key to the JSON token path equivalent</summary>
    /// <param name="key">Key to convert</param>
    /// <returns>Returns the JSON token path equivalent</returns>
    private string convertToTokenPath(string key)
    {
        var jsonStringBuilder = new StringBuilder();

        //Split the key by ':'
        var keyParts = key.Split(':');
        for (var keyPartIndex = 0; keyPartIndex < keyParts.Length; keyPartIndex++)
        {
            var keyPart = keyParts[keyPartIndex];

            if (keyPart.All(char.IsDigit)) { jsonStringBuilder.Append('[').Append(keyPart).Append(']'); }
            else if (keyPartIndex > 0) { jsonStringBuilder.Append('.').Append(keyPart); }
            else { jsonStringBuilder.Append(keyPart); }
        }

        return jsonStringBuilder.ToString();
    }

    /// <summary>Writes the given encrypted key/values to the JSON oconfiguration file</summary>
    /// <param name="encryptedKeyValues">Encrypted key/values to write</param>
    private void writeValues(IDictionary<string, string> encryptedKeyValues)
    {
        try
        {
            if (encryptedKeyValues == null || encryptedKeyValues.Count == 0) { return; }

            using (var stream = new FileStream(this.protectedSource.Path, FileMode.Open, FileAccess.ReadWrite))
            {
                JObject json;

                using (var streamReader = new StreamReader(stream, Encoding.UTF8, true, 4096, true))
                {
                    using (var jsonTextReader = new JsonTextReader(streamReader))
                    {
                        json = JObject.Load(jsonTextReader);

                        foreach (var encryptedKeyValue in encryptedKeyValues)
                        {
                            var tokenPath = this.convertToTokenPath(encryptedKeyValue.Key);
                            var value = json.SelectToken(tokenPath) as JValue;
                            if (value.Value != null) { value.Value = encryptedKeyValue.Value; }
                        }
                    }
                }

                stream.Seek(0, SeekOrigin.Begin);
                using (var streamWriter = new StreamWriter(stream))
                {
                    using (var jsonTextWriter = new JsonTextWriter(streamWriter) { Formatting = Formatting.Indented })
                    {
                        json.WriteTo(jsonTextWriter);
                    }
                }
            }
        }
        catch (Exception exception)
        {
            throw new Exception(string.Format(Localization.ProtectedJsonConfigurationWriteEncryptedValues, this.protectedSource.Path), exception);
        }
    }

    /// <summary>Represents a provider that protects a JSON configuration file</summary>
    /// <param name="source">Settings of the source</param>
    /// <see cref="ArgumentNullException"/>
    public ProtectedJsonConfigurationProvider(ProtectedJsonConfigurationSource source) : base(source)
    {
        this.protectedSource = source as ProtectedJsonConfigurationSource;
    }

    /// <summary>Loads the JSON data from the given <see cref="Stream"/></summary>
    /// <param name="stream"><see cref="Stream"/> to load</param>
    public override void Load(Stream stream)
    {
        //Call the base method first to ensure the data to be available
        base.Load(stream);

        var expressions = protectedSource.EncryptedKeyExpressions;
        if (expressions != null)
        {
            //Dictionary that contains the keys (and their encrypted value) that must be written to the JSON file
            var encryptedKeyValuesToWrite = new Dictionary<string, string>();

            //Iterate through the data in order to verify whether the keys that require to be encrypted, as indeed encrypted.
            //Copy the keys to a new string array in order to avoid a collection modified exception
            var keys = new string[this.Data.Keys.Count];
            this.Data.Keys.CopyTo(keys, 0);

            foreach (var key in keys)
            {
                //Iterate through each expression in order to check whether the current key must be encrypted and is encrypted.
                //If not then encrypt the value and overwrite the key
                var value = this.Data[key];
                if (!string.IsNullOrEmpty(value) && expressions.Any(e => e.IsMatch(key)))
                {
                    this.encryptedKeys.Add(key);

                    //Verify whether the value is encrypted
                    if (!this.isEncrypted(value))
                    {
                        var protectedValue = ProtectedData.Protect(Encoding.UTF8.GetBytes(value), protectedSource.Entropy, protectedSource.Scope);
                        var protectedValueWithPrefix = new List<byte>(encryptedPrefixBytes);
                        protectedValueWithPrefix.AddRange(protectedValue);

                        //Convert the protected value to a base-64 string in order to mask the prefix (for cosmetic purposes)
                        //and overwrite the key with the encrypted value
                        var protectedBase64Value = Convert.ToBase64String(protectedValueWithPrefix.ToArray());
                        encryptedKeyValuesToWrite.Add(key, protectedBase64Value);
                        this.Data[key] = protectedBase64Value;
                    }
                }
            }

            //Write the encrypted key/values to the JSON configuration file
            this.writeValues(encryptedKeyValuesToWrite);
        }
    }

    /// <summary>Attempts to get the value of the given key</summary>
    /// <param name="key">Key to get</param>
    /// <param name="value">Value of the key</param>
    /// <returns>Returns true in case the key has been found</returns>
    public override bool TryGet(string key, out string value)
    {
        if (!base.TryGet(key, out value)) { return false; }
        else if (!this.encryptedKeys.Contains(key)) { return true; }

        //Key is encrypted and must therefore be decrypted in order to return.
        //Note that the decoded base-64 bytes contains the encrypted prefix which must be excluded when unprotection
        var protectedValueWithPrefix = Convert.FromBase64String(value);
        var protectedValue = new byte[protectedValueWithPrefix.Length - encryptedPrefixBytes.Length];
        Buffer.BlockCopy(protectedValueWithPrefix, encryptedPrefixBytes.Length, protectedValue, 0, protectedValue.Length);

        var unprotectedValue = ProtectedData.Unprotect(protectedValue, this.protectedSource.Entropy, this.protectedSource.Scope);
        value = Encoding.UTF8.GetString(unprotectedValue);
        return true;
    }

/// <summary>Provides extensions concerning <see cref="ProtectedJsonConfigurationProvider"/></summary>
public static class ProtectedJsonConfigurationProviderExtensions
{
    /// <summary>Adds a protected JSON file</summary>
    /// <param name="configurationBuilder"><see cref="IConfigurationBuilder"/> in which to apply the JSON file</param>
    /// <param name="path">Path to the JSON file</param>
    /// <param name="optional">Specifies whether the JSON file is optional</param>
    /// <param name="entropy">Byte array to increase protection</param>
    /// <returns>Returns the <see cref="IConfigurationBuilder"/></returns>
    /// <exception cref="ArgumentNullException"/>
    public static IConfigurationBuilder AddProtectedJsonFile(this IConfigurationBuilder configurationBuilder, string path, bool optional, byte[] entropy, params Regex[] encryptedKeyExpressions)
    {
        var source = new ProtectedJsonConfigurationSource(entropy)
        {
            Path = path,
            Optional = optional,
            EncryptedKeyExpressions = encryptedKeyExpressions
        };

        return configurationBuilder.Add(source);
    }
}