使用HCE模式获取静态NFC标签ID [英] Get Static NFC Tag Id with HCE mode

问题描述

我是NFC的新手，所以我在HCE模式下通过调用getTagId()方法测试了几部手机，结果如下:

I'm new in NFC thing, so I tested several phones with calling getTagId() method in HCE mode, and this is the result:

device       | UID
LG G2        | random
LG G3        | static
S4           | random
HTC One Mini | static
Xiaomi mi3   | static

我的问题:

1. 为什么有些电话具有静态UID，而有些却没有?该芯片组相关吗?
2. 是否可以获取固定的UID?我需要它来验证设备.
3. 另一方面，我在Xperia M上使用Kitkat CyanogenMod 11，但是我没有设法将其用于HCE，为什么?

任何可以解释/支持答案的文件吗?

Any documents that can explain/support the answer?

推荐答案

为什么有些电话具有静态UID，而有些却没有静态UID?该芯片组相关吗?

这取决于芯片组和NFC堆栈的实现.据我所知，各种Android NFC设备使用三种不同的场景:

That depends on the chipset and the implementation of the NFC stack. As far as I'm aware of, there are three different scenarios used by various Android NFC devices:

• 该设备具有安全元素，并使用该安全元素的静态UID.
• 该设备在每次打开时都会生成一个新的随机UID.
• 该设备每次由外部读取器设备激活时都会生成一个新的随机UID. IE.每当将外部HF场应用于Android设备的NFC天线时.
• 该设备没有安全元素，但仍使用静态UID(通常不是 unique )，例如0x01020304. [感谢ErikM指出这一点.]

• The device has a secure element and uses the static UID of that secure element.
• The device generates a new random UID whenever it is turned on.
• The device generates a new random UID on every activation by an external reader device. I.e. whenever an external HF field is applied to the NFC antenna of the Android device.
• The device has no secure element but still uses a static UID (typically not unique), e.g. 0x01020304. [Thanks to ErikM for pointing this out.]

是否可以获取固定的UID?

通常，您不能对此产生影响.特别是在不修改Android设备固件(更改为NFC堆栈)的情况下，绝对不可能.有关通过修改libnfc-nci库在Broadcom芯片组上设置UID值的方法，请参见此答案.

Typically, you can't influence this. Specifically without modifying the Android device firmware (changes to the NFC stack) it's definitely not possible. See this answer for a method to set the UID value on Broadcom chipsets through modifying the libnfc-nci library.

我需要它来验证设备的身份.

不要这样做！有关此问题的更多信息，请参见此答案.

Don't do this! See this answer for more information on that.

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