Hi Jason, On Tue, Jun 06, 2017 at 05:23:04PM +0200, Jason A. Donenfeld wrote: > Hey again Eric, > > One thing led to another and I wound up just rewriting all the crypto > in big_keys.c. I'll include this for v4: > > https://git.zx2c4.com/linux-dev/commit/?h=jd/rng-blocker&id=886ff283b9808aecb14aa8e397da8496a9635aed > > Not only was the use of crypto/rng inappropriate, but the decision to > go with aes-ecb is shocking. Seeing that this author had no other > commits in the tree, and that all subsequent commits that mentioned > his name were cleaning up his mess, I just went ahead and removed both > the crypto/rng misusage and changed from aes-ecb to aes-gcm. > > Anyway, I'll wait for some more reviews on v3, and then this can be > reviewed for v4. > > Regards, > Jason
I agree that the use of ECB mode in big_key is broken, and thanks for trying to fix it! I think using GCM is good, but please leave a very conspicuous comment where the nonce is being set to 0, noting that it's safe only because a unique key is used to encrypt every big_key *and* the big_keys are not updatable (via an .update method in the key_type), resulting in each GCM key being used for only a single encryption. Also, I think you should send this to the keyrings mailing list and maintainer so it can be discussed and merged separately from your RNG changes. Eric
