Xamarin.iOS密钥链在试图查询存储NSData的密钥时挂起

Question

我有一个现有的企业部署应用程序，它使用OpenID Connect进行身份验证。通过身份验证后，为了安全起见，我将AuthState对象存储在iOS密钥链中，并能够在以后使用Face/Touch ID对用户进行签名(考虑到AuthState中的刷新令牌仍然有效)。AuthState对象如下所示：

namespace OpenId.AppAuth
{
    [Register ("OIDAuthState", true)]
    public class AuthState : NSObject, INSCoding, INativeObject, IDisposable, INSSecureCoding
    {
        [CompilerGenerated]
        private static readonly IntPtr class_ptr = Class.GetHandle ("OIDAuthState");

        [CompilerGenerated]
        private object __mt_ErrorDelegate_var;

        [CompilerGenerated]
        private object __mt_StateChangeDelegate_var;

        public override IntPtr ClassHandle {
            get;
        }

        [CompilerGenerated]
        public virtual NSError AuthorizationError {
            [Export ("authorizationError")]
            get;
        }

        [CompilerGenerated]
        public virtual IAuthStateErrorDelegate ErrorDelegate {
            [Export ("errorDelegate", ArgumentSemantic.Weak)]
            get;
            [Export ("setErrorDelegate:", ArgumentSemantic.Weak)]
            set;
        }

        [CompilerGenerated]
        public virtual bool IsAuthorized {
            [Export ("isAuthorized")]
            get;
        }

        [CompilerGenerated]
        public virtual AuthorizationResponse LastAuthorizationResponse {
            [Export ("lastAuthorizationResponse")]
            get;
        }

        [CompilerGenerated]
        public virtual RegistrationResponse LastRegistrationResponse {
            [Export ("lastRegistrationResponse")]
            get;
        }

        [CompilerGenerated]
        public virtual TokenResponse LastTokenResponse {
            [Export ("lastTokenResponse")]
            get;
        }

        [CompilerGenerated]
        public virtual string RefreshToken {
            [Export ("refreshToken")]
            get;
        }

        [CompilerGenerated]
        public virtual string Scope {
            [Export ("scope")]
            get;
        }

        [CompilerGenerated]
        public virtual IAuthStateChangeDelegate StateChangeDelegate {
            [Export ("stateChangeDelegate", ArgumentSemantic.Weak)]
            get;
            [Export ("setStateChangeDelegate:", ArgumentSemantic.Weak)]
            set;
        }

        public static IAuthorizationFlowSession PresentAuthorizationRequest (AuthorizationRequest authorizationRequest, UIViewController presentingViewController, AuthStateAuthorizationCallback callback);

        [CompilerGenerated]
        [DesignatedInitializer]
        [EditorBrowsable (EditorBrowsableState.Advanced)]
        [Export ("initWithCoder:")]
        public AuthState (NSCoder coder)
            : base (NSObjectFlag.Empty);

        [CompilerGenerated]
        [EditorBrowsable (EditorBrowsableState.Advanced)]
        protected AuthState (NSObjectFlag t)
            : base (t);

        [CompilerGenerated]
        [EditorBrowsable (EditorBrowsableState.Advanced)]
        protected internal AuthState (IntPtr handle)
            : base (handle);

        [Export ("initWithAuthorizationResponse:")]
        [CompilerGenerated]
        public AuthState (AuthorizationResponse authorizationResponse)
            : base (NSObjectFlag.Empty);

        [Export ("initWithAuthorizationResponse:tokenResponse:")]
        [CompilerGenerated]
        public AuthState (AuthorizationResponse authorizationResponse, TokenResponse tokenResponse)
            : base (NSObjectFlag.Empty);

        [Export ("initWithRegistrationResponse:")]
        [CompilerGenerated]
        public AuthState (RegistrationResponse registrationResponse)
            : base (NSObjectFlag.Empty);

        [Export ("initWithAuthorizationResponse:tokenResponse:registrationResponse:")]
        [DesignatedInitializer]
        [CompilerGenerated]
        public AuthState (AuthorizationResponse authorizationResponse, TokenResponse tokenResponse, RegistrationResponse registrationResponse)
            : base (NSObjectFlag.Empty);

        [Export ("encodeWithCoder:")]
        [CompilerGenerated]
        [Preserve (Conditional = true)]
        public virtual void EncodeTo (NSCoder encoder);

        [Export ("performActionWithFreshTokens:")]
        [CompilerGenerated]
        public unsafe virtual void PerformWithFreshTokens ([BlockProxy (typeof(ObjCRuntime.Trampolines.NIDAuthStateAction))] AuthStateAction action);

        [Export ("performActionWithFreshTokens:additionalRefreshParameters:")]
        [CompilerGenerated]
        public unsafe virtual void PerformWithFreshTokens ([BlockProxy (typeof(ObjCRuntime.Trampolines.NIDAuthStateAction))] AuthStateAction action, NSDictionary<NSString, NSString> additionalParameters);

        [Export ("authStateByPresentingAuthorizationRequest:UICoordinator:callback:")]
        [CompilerGenerated]
        public unsafe static IAuthorizationFlowSession PresentAuthorizationRequest (AuthorizationRequest authorizationRequest, IAuthorizationUICoordinator UICoordinator, [BlockProxy (typeof(ObjCRuntime.Trampolines.NIDAuthStateAuthorizationCallback))] AuthStateAuthorizationCallback callback);

        [Export ("setNeedsTokenRefresh")]
        [CompilerGenerated]
        public virtual void SetNeedsTokenRefresh ();

        [Export ("tokenRefreshRequest")]
        [CompilerGenerated]
        public virtual TokenRequest TokenRefreshRequest ();

        [Export ("tokenRefreshRequestWithAdditionalParameters:")]
        [CompilerGenerated]
        public virtual TokenRequest TokenRefreshRequest (NSDictionary<NSString, NSString> additionalParameters);

        [Export ("updateWithAuthorizationResponse:error:")]
        [CompilerGenerated]
        public virtual void Update (AuthorizationResponse authorizationResponse, NSError error);

        [Export ("updateWithTokenResponse:error:")]
        [CompilerGenerated]
        public virtual void Update (TokenResponse tokenResponse, NSError error);

        [Export ("updateWithAuthorizationError:")]
        [CompilerGenerated]
        public virtual void Update (NSError authorizationError);

        [Export ("updateWithRegistrationResponse:")]
        [CompilerGenerated]
        public virtual void UpdateWithRegistrationResponse (RegistrationResponse registrationResponse);

        [CompilerGenerated]
        protected override void Dispose (bool disposing);
    }
}

在iOS 12.1更新之前，一切都很好

问题:安装ios 12.1更新后的，只有在以发布模式运行(在连接到VS for Mac调试器时以开发模式进行调试时工作)查询密钥链中存储此AuthState对象的二进制NSData表示形式的现有密钥时，才会挂起该应用程序，最终该应用程序因响应时间超过10秒而终止。

有人遇到过类似的问题吗？如果有人能揭示这里可能发生的事情，或者指出我的正确方向，那将是令人惊奇的。

其他信息：

如何获得NSData二进制表示AppAuth对象：

NSData authStateData = NSKeyedArchiver.ArchivedDataWithRootObject(authState);

如何将这个NSData保存到密钥链中：

    var secAccess = new SecAccessControl(SecAccessible.WhenUnlockedThisDeviceOnly, SecAccessControlCreateFlags.UserPresence);
    var secRecord = new SecRecord(SecKind.GenericPassword)
    {
        Account = "keystring",
        Service = "ServiceNameString",
        Label = "keystring",
        ValueData = authStateData,
        AccessControl = secAccess
    };
    var result = SecKeyChain.Add(secRecord);

如何查询keychain中的现有数据

var searchRecord = new SecRecord(SecKind.GenericPassword)
{
    Service = ServiceName,
    Label = key,
};
var match = SecKeyChain.QueryAsRecord(searchRecord, out SecStatusCode resultCode);

我检查了一下，设备日志中没有明显的错误。我错过了iOS 12.1中的一个变化，它对此有很大影响吗？

更新:我重构了代码，使其只在密钥链中存储加密密钥密码，而不是存储整个AuthState对象，并将加密的序列化AuthState存储到本地文件中。仍然可以看到相同的问题，在设备上的调试模式中，所有操作、写入和从密钥链的读取都很好，当没有在同一设备上附加调试器的情况下运行时，相同的构建、写入，当成功验证TouchID/FaceID后读取挂起时，Xamarin.iOS SDK中是否有一个bug没有赶上最新的iOS中引起这一问题的一些变化？

Answer 1

我已经解决了我的问题，这似乎是某种种族条件锁定了应用程序，因为调用保存到关键链是在主线程上完成的。通常情况下，这个调用是非常快速的，并且在过去锁定任何东西都没有问题，但是iOS 12.1更新中的一些东西改变了这一点。无论如何，我只是显式地运行代码，将加密密码保存到后台线程中的密钥链中，解决了这个问题：

Task.Run(() =>
{
    var keychain = new KeyChain();
    keychain.SetValueForKey("securedvalue", "securedvaluekey");
}).ConfigureAwait(false);

Answer 2

您应该启用密钥链共享权限。

在Entitlements.plist中

​

这是一个你可以参考的similar case。