[jira] [Created] (HADOOP-11343) Overflow is not properly handled in caclulating final iv for AES CTR

["Jerry Chen (JIRA)" <ji...@apache.org>]

Jerry Chen created HADOOP-11343:
-----------------------------------

             Summary: Overflow is not properly handled in caclulating final iv for AES CTR
                 Key: HADOOP-11343
                 URL: https://issues.apache.org/jira/browse/HADOOP-11343
             Project: Hadoop Common
          Issue Type: Bug
          Components: security
    Affects Versions: trunk-win
            Reporter: Jerry Chen


In the AesCtrCryptoCodec calculateIV, as the init IV is a random generated 16 bytes, 

final byte[] iv = new byte[cc.getCipherSuite().getAlgorithmBlockSize()];
      cc.generateSecureRandom(iv);

Then the following calculation of iv and counter on 8 bytes (64bit) space would easily cause overflow and this overflow gets lost.  The result would be the 128 bit data block was encrypted with a wrong counter and cannot be decrypted by standard aes-ctr.

/**
   * The IV is produced by adding the initial IV to the counter. IV length 
   * should be the same as {@link #AES_BLOCK_SIZE}
   */
  @Override
  public void calculateIV(byte[] initIV, long counter, byte[] IV) {
    Preconditions.checkArgument(initIV.length == AES_BLOCK_SIZE);
    Preconditions.checkArgument(IV.length == AES_BLOCK_SIZE);
    
    System.arraycopy(initIV, 0, IV, 0, CTR_OFFSET);
    long l = 0;
    for (int i = 0; i < 8; i++) {
      l = ((l << 8) | (initIV[CTR_OFFSET + i] & 0xff));
    }
    l += counter;
    IV[CTR_OFFSET + 0] = (byte) (l >>> 56);
    IV[CTR_OFFSET + 1] = (byte) (l >>> 48);
    IV[CTR_OFFSET + 2] = (byte) (l >>> 40);
    IV[CTR_OFFSET + 3] = (byte) (l >>> 32);
    IV[CTR_OFFSET + 4] = (byte) (l >>> 24);
    IV[CTR_OFFSET + 5] = (byte) (l >>> 16);
    IV[CTR_OFFSET + 6] = (byte) (l >>> 8);
    IV[CTR_OFFSET + 7] = (byte) (l);
  }



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