Gentoo Archives: gentoo-dev

From: Anton Molyboha <anton.stay.connected@×××××.com>
To: gentoo-dev@l.g.o
Subject: Re: [gentoo-dev] Manifest2 hashes, take n+1-th
Date: Fri, 20 Oct 2017 22:43:03
Message-Id: CA+QdaqxG9f2q_C0WtesJxpj6snSkVLq0gWHxp8JjrG3etncfgQ@mail.gmail.com
In Reply to: Re: [gentoo-dev] Manifest2 hashes, take n+1-th by Gordon Pettey
1 On Thu, Oct 19, 2017 at 6:49 PM, Gordon Pettey <petteyg359@×××××.com> wrote:
2
3 > On Thu, Oct 19, 2017 at 5:32 PM, Hanno Böck <hanno@g.o> wrote:
4 >
5 >> On Thu, 19 Oct 2017 21:08:40 +0200
6 >> Michał Górny <mgorny@g.o> wrote:
7 >>
8 >> > manifest-hashes = SHA512 SHA3_512
9 >>
10 >> Counterproposal: Just use SHA512.
11 >>
12 >> There isn't any evidence that any SHA2-based hash algorithm is going to
13 >> be broken any time soon. If that changes there will very likely be
14 >> decades of warning before a break becomes practical.
15 >>
16 >> Having just one hash is simpler and using a well supported one like
17 >> SHA512 may make things easier than using something that's still not
18 >> very widely supported.
19 >
20 >
21 > Yet having more than one lets you match make sure nobody hijacked your
22 > manifest file when an attack vector is inevitably discovered for the old
23 > new algorithm (whether SHA2, SHA3, or BLAKE2), because you'll be able to
24 > confirm the file is the same one that matched the old checksum in addition
25 > to the new one.
26 >
27
28 Would it make sense then to support several hashes but let the user
29 optionally turn off the verification of some of them, depending on the
30 user's security vs performance requirements?
31
32 --
33 Anton

Replies

Subject Author
Re: [gentoo-dev] Manifest2 hashes, take n+1-th Gordon Pettey <petteyg359@×××××.com>
Re: [gentoo-dev] Manifest2 hashes, take n+1-th "Michał Górny" <mgorny@g.o>