[PATCH 07/10] password: add pbkdf2 support

[Jan Lübbe]

On Mo, 2015-03-16 at 11:15 +0100, Jean-Christophe PLAGNIOL-VILLARD wrote:
> We will use "barebox_password" as salt and 10000 round to generate a
> 64 bytes key.

The purpose of a salt is to protect a against dictionary or
rainbow-table (precomputed) attacks. That means that the Salt must be
randomly generated and saved with the password.

For setting a new password in barebox, even a low entropy salt will make
attacks significantly more expensive. So we should add some entropy from
user interaction timing in that case.

For hashing a password at compile time, we should get the salt from the
host system.

Regards,
Jan
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