+
+ private byte[] createIV(long machineId, long localSequenceNumber) {
+ ByteBuffer buffer = ByteBuffer.allocate(IV_SIZE);
+ buffer.putLong(machineId);
+ long localSequenceNumberShifted = localSequenceNumber << 16;
+ buffer.putLong(localSequenceNumberShifted);
+ return buffer.array();
+
+ }
+
+ private byte[] encryptSlotAndPrependIV(byte[] rawData, byte[] ivBytes) {
+ try {
+ ivBytes = new byte[IV_SIZE];
+ IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
+ //Cipher cipher = Cipher.getInstance("AES/CTR/PKCS5Padding");
+ // We no longer need PKCS5Padding for CTR mode
+ // There was a bug that the crypto library for Android that adds 16 more bytes into
+ // the existing 2048 bytes after HMAC is calculated so that this causes HMAC mismatch
+ // on the Java side that is expecting exactly 2048 bytes of padding.
+ Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
+ cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
+
+ byte[] encryptedBytes = cipher.doFinal(rawData);
+ byte[] bytes = new byte[encryptedBytes.length + IV_SIZE];
+ System.arraycopy(ivBytes, 0, bytes, 0, ivBytes.length);
+ System.arraycopy(encryptedBytes, 0, bytes, IV_SIZE, encryptedBytes.length);
+
+ return bytes;
+
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Failed To Encrypt");
+ }
+ }
+
+
+ private byte[] stripIVAndDecryptSlot(byte[] rawData) {
+ try {
+ byte[] ivBytes = new byte[IV_SIZE];
+ byte[] encryptedBytes = new byte[rawData.length - IV_SIZE];
+ System.arraycopy(rawData, 0, ivBytes, 0, IV_SIZE);
+ System.arraycopy(rawData, IV_SIZE, encryptedBytes, 0 , encryptedBytes.length);
+
+ IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
+
+ //Cipher cipher = Cipher.getInstance("AES/CTR/PKCS5Padding");
+ // We no longer need PKCS5Padding for CTR mode
+ // There was a bug that the crypto library for Android that adds 16 more bytes into
+ // the existing 2048 bytes after HMAC is calculated so that this causes HMAC mismatch
+ // on the Java side that is expecting exactly 2048 bytes of padding.
+ Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
+ cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
+
+ return cipher.doFinal(encryptedBytes);
+
+ } catch (Exception e) {
+ e.printStackTrace();
+ throw new Error("Failed To Decrypt");
+ }
+ }
+
projects / iot2.git / commitdiff