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Yi Liu commented on HADOOP-11343: --------------------------------- Andrew, I agree with you and [~yoderme] about the likelihood analysis. I think we just need to fix the overflow without other changes. > 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: 2.6.0 > Reporter: Jerry Chen > Assignee: Jerry Chen > Priority: Blocker > Attachments: HADOOP-11343.patch > > > 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. > {code} > /** > * 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); > } > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)