Examples with XTEAEngine org.spongycastle.crypto.engines.XTEAEngine used on opensource projects

Example 1 with XTEAEngine

use of org.spongycastle.crypto.engines.XTEAEngine in project fitness-app by seemoo-lab.

the class Firmware method rebootToBSLold.

public static String rebootToBSLold(Activity activity) throws UnsupportedEncodingException {
    /*int headerlength = 14;
        int inlength = 0;
        int plainlength = 0;
        int trailerlenght = 11;*/
    String outStr = "";
    /*File bslupdate = new File("/sdcard/788-bsl-plain.bin");
        byte[] rawInput = {0} ; //ExternalStorage.loadByteArray("/sdcard/788-bsl-plain.bin", activity);

        try {
            rawInput = fullyReadFileToBytes(bslupdate);
            //rawInput = ExternalStorage.loadByteArray("fwup-bsl-plain.bin",activity);
        }catch(IOException e) {

        }

        byte[] header = new byte[headerlength];
        byte[] trailer = new byte[trailerlenght];
        inlength = rawInput.length;
        plainlength = inlength - headerlength-trailerlenght;
        byte[] plain = new byte[plainlength];

        System.arraycopy(rawInput, 0, header, 0, headerlength);
        System.arraycopy(rawInput, headerlength, plain, 0, plainlength);
        System.arraycopy(rawInput, inlength-trailerlenght, trailer,0,trailerlenght);


        // get the nonce from the dump
        byte[] nonce = Arrays.copyOfRange(rawInput, 6, 10);

        //compute the initial counter value using the nonce
        byte[] counter = computeCounter(nonce);

        // use the XTEA block cipher in counter mode (CTR)
        SICBlockCipher cipher = new SICBlockCipher(new XTEAEngine());
        // initialize using the key and the initial counter value.
        cipher.init(true,new ParametersWithIV(new KeyParameter(ConstantValues.FITBIT_KEY), counter));


        byte[] encrypted = new byte[plainlength];


        //decrypt the encrypted part of the megadump, that is starting after byte 16
        cipher.processBytes(plain, 0, plainlength, encrypted, 0);

        //Log.e(TAG, "Decryped Dump");
        String strenc = toHexString(encrypted);
        Log.e(TAG, strenc);

        byte[] out = new byte[inlength];

        System.arraycopy(header, 0, out, 0, headerlength);
        System.arraycopy(encrypted, 0, out, headerlength, encrypted.length);

        byte[] cmac = calculateCMAC(nonce, plain, plainlength);

        System.arraycopy(cmac, 0, out, headerlength + encrypted.length, cmac.length);
        System.arraycopy(header, headerlength - 4, out, headerlength + encrypted.length + cmac.length, 3);*/
    int bslHeaderLength = ConstantValues.REBOOT_TO_BSL_HEADER.length;
    int bslDataLength = ConstantValues.REBOOT_TO_BSL_DATA.length;
    byte[] command = new byte[bslHeaderLength + bslDataLength];
    byte[] nonce = Arrays.copyOfRange(ConstantValues.REBOOT_TO_BSL_HEADER, 6, 10);
    // compute the initial counter value using the nonce
    // Crypto.computeCounter(nonce);
    byte[] counter = { 0 };
    // use the XTEA block cipher in counter mode (CTR)
    SICBlockCipher cipher = new SICBlockCipher(new XTEAEngine());
    // initialize using the key and the initial counter value.
    cipher.init(true, new ParametersWithIV(new KeyParameter(Utilities.hexStringToByteArray(AuthValues.ENCRYPTION_KEY)), counter));
    byte[] encrypted = new byte[bslDataLength];
    // decrypt the encrypted part of the megadump, that is starting after byte 16
    cipher.processBytes(command, 0, bslDataLength, encrypted, 0);
    System.arraycopy(ConstantValues.REBOOT_TO_BSL_HEADER, 0, command, 0, bslHeaderLength);
    System.arraycopy(encrypted, 0, command, bslHeaderLength, bslDataLength);
    outStr = Utilities.byteArrayToHexString(command);
    return outStr.toLowerCase();
}

Example 2 with XTEAEngine

use of org.spongycastle.crypto.engines.XTEAEngine in project fitness-app by seemoo-lab.

the class Crypto method encryptDump.

/*
    Fitbit Flex/One/Charge firmware uses XTEA in EAX mode, we encrypt according to this.
     TODO: if we find a vulnerability for AES trackers, this method should also be able to use AES/EAX...
     Length fields must match, otherwise result can become null ...
     */
public static String encryptDump(byte[] dump, Activity activity) throws InvalidCipherTextException {
    int headerlength = 14;
    int inlength = 0;
    int plainlength = 0;
    int trailerlenght = 11;
    String outStr = "";
    byte[] header = new byte[headerlength];
    byte[] trailer = new byte[trailerlenght];
    inlength = dump.length;
    plainlength = inlength - headerlength - trailerlenght;
    byte[] plain = new byte[plainlength];
    System.arraycopy(dump, 0, header, 0, headerlength);
    System.arraycopy(dump, headerlength, plain, 0, plainlength);
    System.arraycopy(dump, inlength - trailerlenght, trailer, 0, trailerlenght);
    // Set Crypt-Byte in header
    header[4] = (byte) 0x01;
    // Nonce should not be zero... //TODO make nonce random
    // header[6] = (byte) 0xab;
    // header[7] = (byte) 0xcd;
    // get the nonce from the dump
    byte[] nonce = Arrays.copyOfRange(header, 6, 10);
    // cmac (tag) length in bytes
    int mac_len = 8 * 8;
    XTEAEngine engine = new XTEAEngine();
    EAXBlockCipher eax = new EAXBlockCipher(engine);
    Log.e(TAG, "key: " + getKey());
    Log.e(TAG, "nonce: " + Utilities.byteArrayToHexString(nonce));
    AEADParameters params = new AEADParameters(new KeyParameter(getKey()), mac_len, nonce, null);
    // TODO switch true to false here to implement a decryption method, apply it to microdumps/megadumps
    eax.init(true, params);
    byte[] result = new byte[eax.getOutputSize(plainlength)];
    int resultlength = eax.processBytes(plain, 0, plainlength, result, 0);
    eax.doFinal(result, resultlength);
    byte[] out = new byte[inlength];
    System.arraycopy(header, 0, out, 0, headerlength);
    System.arraycopy(result, 0, out, headerlength, result.length);
    System.arraycopy(header, headerlength - 4, out, headerlength + result.length, 3);
    outStr = Utilities.byteArrayToHexString(out);
    return outStr;
}

Example 3 with XTEAEngine

use of org.spongycastle.crypto.engines.XTEAEngine in project fitness-app by seemoo-lab.

the class AuthenticationInteraction method generateCMAC.

/**
 * Calculates the cmac.
 *
 * @param sequenceNumber    The sequence number to calculate the cmac with.
 * @param authenticationKey The authentication key to calculate the cmac with.
 * @return The calculated cmac.
 */
private String generateCMAC(byte[] sequenceNumber, String authenticationKey) {
    String seqNum = Utilities.byteArrayToHexString(sequenceNumber);
    if (seqNum.length() > 4 && seqNum.substring(0, 4).equals(ConstantValues.AUTHENTICATION_CHALLENGE)) {
        seqNum = seqNum.substring(20);
        seqNum = Utilities.rotateBytes(seqNum);
        byte[] authKey = Utilities.hexStringToByteArray(authenticationKey);
        BlockCipher cypher;
        switch(deviceType) {
            case 1:
                cypher = new XTEAEngine();
                break;
            case 2:
                cypher = new AESEngine();
                break;
            default:
                cypher = null;
                Log.e(TAG, "Error: AuthenticationInteraction key not available!");
        }
        if (cypher != null && authKey != null) {
            CMac mac = new CMac(cypher, 64);
            mac.init(new KeyParameter(authKey));
            byte[] counter = Utilities.intToByteArray(Integer.parseInt(seqNum, 16));
            mac.update(counter, 0, 4);
            byte[] bArr = new byte[8];
            mac.doFinal(bArr, 0);
            return Utilities.byteArrayToHexString(bArr);
        }
    }
    return null;
}