From: Richard Weinberger <richard@nod.at>
Subject: Re: Idea behind EXT4_IOC_GET_ENCRYPTION_PWSALT?
Date: Wed, 30 Nov 2016 09:29:40 +0100
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Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Ext4 Developers List <linux-ext4@vger.kernel.org>,
        Michael Halcrow <mhalcrow@google.com>,
        Theodore Ts'o <tytso@mit.edu>, muslukhovi@gmail.com,
        David Gstir <david@sigma-star.at>
To: Joe Richey <joerichey@google.com>
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Joe,

On 30.11.2016 01:44, Joe Richey wrote:
> Richard,
> 
> Our current design for fscrypt (tentative name for the userspace
> filesystem encryption manager) does not use the global filesystem salt
> (EXT4_IOC_GET_ENCRYPTION_PWSALT), we are planning on having a
> different salt for each password used in the system. We are using
> planning on using Argon2id as the password stretching algorithm, so
> we'll have costs for memory, time, and parallelism stored for each
> password as well as a salt.


Makes sense.
So, for now I'll not implement this ioctl command in UBIFS.

Thanks,
//richard