确定Touch ID保护的钥匙串项是否存在？

Question

有没有办法确定是否已使用Touch ID访问控制在iOS钥匙串中设置了项目(密码,令牌等)而没有提示用户输入Touch ID？在执行操作之前,我们需要确定凭证是否已保存到钥匙串(带有Touch ID保护),但我们不希望使用Touch ID提示中断用户.

我试过以下......

NSMutableDictionary *query = ...
query[(__bridge id)kSecUseNoAuthenticationUI] = (__bridge id)kCFBooleanTrue;

OSStatus opStatus = SecItemCopyMatching((__bridge CFDictionaryRef)query, NULL);

...

但是,当调用此代码时,用户仍会看到Touch ID提示.我们不希望任何东西在UI上进行显示,而只是想在返回一个错误OSStatus,如果触摸ID 会被需要.

有什么想法吗？

Answer 1

基于neoneye的代码和Swift 3.我添加了errSecAuthFailed.

    query[kSecClass as String] : kSecClassGenericPassword,
    query[kSecAttrService as String] : "serviceName"    
    query[kSecUseAuthenticationUI as String] = kSecUseAuthenticationUIFail

    DispatchQueue.global().async {

        var result : AnyObject?
        let status = SecItemCopyMatching(query as CFDictionary, &result)

        if status == errSecInteractionNotAllowed {

            DispatchQueue.main.async {

                // item exists
            }
        } else if status == errSecAuthFailed {

            DispatchQueue.main.async {

                // item exists but someone removed the touch id or passcode
            }
        } else if status == errSecItemNotFound {

            DispatchQueue.main.async {

                // it does not exist
            }
        } else {

            DispatchQueue.main.async {

                // another OSStatus
            }
        }
    }

Answer 2

NSDictionary *query = @{
                        (__bridge id)kSecClass: (__bridge id)kSecClassGenericPassword,
                        (__bridge id)kSecAttrService: @"SampleService",
                        (__bridge id)kSecUseNoAuthenticationUI: @YES
                        };

dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    CFTypeRef dataTypeRef = NULL;
    OSStatus status = SecItemCopyMatching((__bridge CFDictionaryRef)(query), &dataTypeRef);
    if (status == errSecInteractionNotAllowed) {
        NSLog(@"ITEM EXIST");
    } else if (status == errSecItemNotFound) {
        NSLog(@"ITEM DOES NOT EXIST");
    } else {
        NSLog(@"status: %@", @(status));
    }
});