使用MifareUltralight.transceive崩溃在Android中设置NTAG213密码,没有异常抛出

时间:2017-08-03 07:15:54

标签: java android nfc password-protection mifare

我试图在空的NTAG213标签上设置密码,但是当我编写PACK和PWD时,我的应用程序只是崩溃,没有异常抛出。我确实得到我的应用程序远远足以编写有效的NDEF消息并读取它们,似乎我也可以写入其他配置页面(2Ah和29h用于配置密码保护)。当我开始编写PACK时,我的应用程序崩溃但没有抛出我期望的MifareUltralight.transceive(byte []数据)的IOException。

这是我的writeAndProtect方法的源代码:

private void writeAndProtectTag(final Intent intent, final String message) {
    // Run the entire process in its own thread as MifareUltralight.transceive(byte[] data);
    // Should not be run in main thread according to <https://developer.android.com/reference/android/nfc/tech/MifareUltralight.html#transceive(byte[])>
    (new Thread(new Runnable() {
        // Password has to be 4 characters
        // Password Acknowledge has to be 2 characters
        byte[] pwd      = "-_bA".getBytes();
        byte[] pack     = "cC".getBytes();

        @Override
        public void run() {
            // Store tag object for use in MifareUltralight and Ndef
            Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
            MifareUltralight mifare = null;
            int debugCounter = 0;

            // Whole process is put into a big try-catch trying to catch the transceive's IOException
            try {
                mifare = MifareUltralight.get(tag);

                mifare.connect();
                while(!mifare.isConnected());
                byte[] response;

                // Authenticate with the tag first
                // In case it's already been locked
                try {
                    response = mifare.transceive(new byte[]{
                            (byte) 0x1B, // PWD_AUTH
                            pwd[0], pwd[1], pwd[2], pwd[3]
                    });
                    // Check if PACK is matching expected PACK
                    // This is a (not that) secure method to check if tag is genuine
                    if ((response != null) && (response.length >= 2)) {
                        byte[] packResponse = Arrays.copyOf(response, 2);
                        if (!(pack[0] == packResponse[0] && pack[1] == packResponse[1])) {
                            Toast.makeText(ctx, "Tag could not be authenticated:\n" + packResponse.toString() + "≠" + pack.toString(), Toast.LENGTH_LONG).show();
                        }
                    }
                }catch(IOException e){
                    e.printStackTrace();
                }

                // Get Page 2Ah
                response = mifare.transceive(new byte[] {
                        (byte) 0x30, // READ
                        (byte) 0x2A  // page address
                });
                // configure tag as write-protected with unlimited authentication tries
                if ((response != null) && (response.length >= 16)) {    // read always returns 4 pages
                    boolean prot = false;                               // false = PWD_AUTH for write only, true = PWD_AUTH for read and write
                    int authlim = 0;                                    // 0 = unlimited tries
                    mifare.transceive(new byte[] {
                            (byte) 0xA2, // WRITE
                            (byte) 0x2A, // page address
                            (byte) ((response[0] & 0x078) | (prot ? 0x080 : 0x000) | (authlim & 0x007)),    // set ACCESS byte according to our settings
                            0, 0, 0                                                                         // fill rest as zeros as stated in datasheet (RFUI must be set as 0b)
                    });
                }
                // Get page 29h
                response = mifare.transceive(new byte[] {
                        (byte) 0x30, // READ
                        (byte) 0x29  // page address
                });
                // Configure tag to protect entire storage (page 0 and above)
                if ((response != null) && (response.length >= 16)) {  // read always returns 4 pages
                    int auth0 = 0;                                    // first page to be protected
                    mifare.transceive(new byte[] {
                            (byte) 0xA2, // WRITE
                            (byte) 0x29, // page address
                            response[0], 0, response[2],              // Keep old mirror values and write 0 in RFUI byte as stated in datasheet
                            (byte) (auth0 & 0x0ff)
                    });
                }

                // Send PACK and PWD
                // set PACK:
                mifare.transceive(new byte[] {
                        (byte)0xA2,
                        (byte)0x2C,
                        pack[0], pack[1], 0, 0  // Write PACK into first 2 Bytes and 0 in RFUI bytes
                });
                // set PWD:
                mifare.transceive(new byte[] {
                        (byte)0xA2,
                        (byte)0x2B,
                        pwd[0], pwd[1], pwd[2], pwd[3] // Write all 4 PWD bytes into Page 43
                });

            } catch (IOException e) {
                //Trying to catch any exception that may be thrown
                e.printStackTrace();
            } catch (Exception e) {
                //Trying to catch any exception that may be thrown
                e.printStackTrace();
            }
            try {
                mifare.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

            // Generate NdefMessage to be written onto the tag
            NdefMessage msg = null;
            try {
                NdefRecord r1 = NdefRecord.createMime("text/plain", message.getBytes("UTF-8"));
                NdefRecord r2 = NdefRecord.createApplicationRecord("com.example.myname.myapplication");
                msg = new NdefMessage(r1, r2);
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }

            // Generate Ndef object from tag object
            Ndef ndef = Ndef.get(tag);

            // Connect NDEF, write message and close connection
            try {
                ndef.connect();
                ndef.writeNdefMessage(msg);
                ndef.close();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (FormatException e) {
                e.printStackTrace();
            } catch (Exception e) {
                //Trying to catch any exception that may be thrown
                e.printStackTrace();
            }
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    btn.setImageResource(R.drawable.arrow_red);
                    tv.setText("");
                }
            });
            curAction = "handle";
        }
    })).start();
}

编辑:我不知道昨天Android Studio是否出现问题,或者您的解决方案是否真的改变了这种情况,但我更新了代码,现在得到以下异常:

E/AndroidRuntime: FATAL EXCEPTION: Thread-4
                       Process: com.example.alex.nfcapppce, PID: 25918
                       java.lang.IllegalStateException: Close other technology first!
                           at android.nfc.Tag.setConnectedTechnology(Tag.java:458)
                           at android.nfc.tech.BasicTagTechnology.connect(BasicTagTechnology.java:78)
                           at android.nfc.tech.Ndef.connect(Ndef.java)
                           at com.example.alex.nfcapppce.MainActivity$2.run(MainActivity.java:194) //The line saying ndef.connect()
                           at java.lang.Thread.run(Thread.java:761)

我不太明白为什么会这样开心,因为首先我连接mifare,等到它连接,进行收发,关闭我的mifare然后用ndef.connect()阻止调用。这是否意味着在我的收发块中的某个地方我得到了一个例外,因此我没有正确关闭mifare并且无法打开ndef?这很奇怪,因为我没有得到异常,即使我只用Exception换掉了IOException,所以无论确切的类型如何,我都会捕获每个异常。

编辑2 :我现在知道应用程序在此异常中结束的原因。代码实际上工作,我的标签现在用密码保护,当我再次尝试使用相同的标签时,我首先不进行身份验证,因此收发失败,导致try-catch块的中断,该块也包含close函数。我通过在整个线程中使用MifareUltralight对象并在运行ndef.connect()部分之前关闭它来解决这个问题。

现在我的(希望)最后一个问题是:我可以使用Ndef类进行身份验证吗?我的Ndef对象似乎没有一个验证方法,所以我必须再次使用MifareUltralight。但是当我关闭MifareUltralight连接以打开Ndef连接时,身份验证不会丢失?或者是我唯一可能使用密码保护标记写Ndef消息 使用MifareUltralight.writepage(byte [] addr,byte []数据)将字符串切割成4字节页并一个接一个地写入?当我使用上面更新时,我从ndef.writeNdefMessage()得到一个IOException,我想这意味着关闭mifare连接也是unauth&#39; d。

提前致谢。

1 个答案:

答案 0 :(得分:1)

使用MifareUltralight技术时,您永远不会连接到标签。因此,调用mifare.transceive()将导致异常。您的应用程序崩溃,因为此异常可能不是IOException的实例(您将在代码中捕获该实例)。

因此,请务必致电

mifare.connect();
在收发任何命令之前

,并确保在此之后再次关闭实例:

try {
    mifare.close();
} catch (Exception ignored) {}