On Wed, Jan 26, 2022 at 03:56:44PM -0500, Yael Tiomkin wrote: > On Wed, Jan 26, 2022 at 9:51 AM Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote: > > > > On Wed, Jan 26, 2022 at 04:47:22PM +0200, Jarkko Sakkinen wrote: > > > On Tue, Jan 18, 2022 at 01:26:05PM -0500, Martin Ross wrote: > > > > Hi Jarkko, > > > > > > > > I have been working with Yael on this project so I thought I might add > > > > a bit of background here around the use case that this series of > > > > patches is trying to address. > > > > > > > > At a high level we are trying to provide users of encryption that have > > > > key management hierarchies a better tradeoff between security and > > > > availability. For available and performance reasons master keys often > > > > need to be released (or derived/wrapped keys created) outside of a KMS > > > > to clients (which may in turn further wrap those keys in a series of > > > > levels). What we are trying to do is provide a mechanism where the > > > > wrapping/unwrapping of these keys is not dependent on a remote call at > > > > runtime. e.g. To unwrap a key if you are using AWS KMS or Google > > > > Service you need to make an RPC. In practice to defend against > > > > availability or performance issues, designers end up building their > > > > own kms and effectively encrypting everything with a DEK. The DEK > > > > encrypts same set as the master key thereby eliminating the security > > > > benefit of keeping the master key segregated in the first place. > > > > Mainly this part (would be enough to explain why it is there). > > > > BR, Jarkko > > Hi Jarkko, > > As for the commit message, WDYT about the following: > > KEYS: encrypted: Instantiate key with user-provided decrypted data > > For availability and performance reasons master keys often need to be > released outside of a KMS to clients. It would be beneficial to provide a > mechanism where the wrapping/unwrapping of DEKs is not dependent > on a remote call at runtime yet security is not (or only minimally) compromised. > Master keys could be securely stored in the Kernel and be used to wrap/unwrap > keys from userspace. > > The encrypted.c class supports instantiation of encrypted keys with > either an already-encrypted key material, or by generating new key > material based on random numbers. This patch defines a new datablob > format: [<format>] <master-key name> <decrypted data length> > <decrypted data> that allows to inject and encrypt user-provided > decrypted data. > > > I want to make sure we're on the same page before publishing a new version. > > Thanks, > Yael It looks really good. /Jarkko
