tree ce773e00a921e4fbe391b3b866318f25851e89b5
parent 0d94caa0a1be8b49be3662555725e91b47f5e5ba
author Elly <ellyjones@chromium.org> 1733859271 +0000
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> 1733859271 +0000

oscrypt: refactor linux sync crypto

OSCryptLinux supports two different password derivation schemes: "1.0",
which uses an encryption key of:

    PBKDF2-HMAC-SHA1("peanuts", "saltysalt", iterations = 1)

and "1.1", which uses an encryption key of:

    PBKDF2-HMAC-SHA1(k, "saltysalt", iterations = 1)

where k is a random string stored by the system's secret store. There is
also a fallback mode to work around https://crbug.com/1195256 which uses
the key:

    PBKDF2-HMAC-SHA1("", "saltysalt", iterations = 1)

The eagle-eyed reader will notice that both the v1.0 key and the
fallback empty key are actually constant values, since PBKDF2-HMAC-SHA1
is a deterministic function.

Therefore, this change:
* Removes v1.0 key derivation, replacing it with a hardcoded constant
  equal to the output of that PBKDF2-HMAC-SHA1 call
* Removes the empty key derivation, also replacing it with a hardcoded
  constant
* Simplifies the OSCryptLinux code as a result by removing some error
  paths & places where keys were regenerated
* Reworks the "raw key" mode used in the network service sandbox,
  replacing it with a mode that disables v1.1 key generation and
  prefills the cached v1.1 key - this is used to have the network
  service's key match the browser process's key.
* Drops dependencies on the deprecated Encryptor and SymmetricKey APIs
  for OSCryptLinux

Change-Id: I8060a170d457370e104fdfd89005ccfc0ee562da
Bug: 375425829
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6064465
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Elly FJ <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1394452}