lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 13 May 2019 14:11:45 +0200
From:   Michal Kubecek <>
Cc:     Weilong Chen <>,,,
Subject: Re: [PATCH net-next] ipv4: Add support to disable icmp timestamp

On Mon, May 13, 2019 at 08:06:37PM +0800, Weilong Chen wrote:
> On 2019/5/13 19:49, Michal Kubecek wrote:
> > One idea is that there may be applications using current time as a seed
> > for random number generator - but then such application is the real
> > problem, not having correct time.
> > 
> Yes, the target computer responded to an ICMP timestamp request. By
> accurately determining the target's clock state, an attacker can more
> effectively attack certain time-based pseudorandom number generators (PRNGs)
> and the authentication systems that rely on them.
> So, the 'time' may become sensitive information. The OS should not leak it
> out.

So you are effectively saying that having correct time is a security

I'm sorry but I cannot agree with that. Seeding PRNG with current time
is known to be a bad practice and if some application does it, the
solution is to fix the application, not obfuscating system time.

Michal Kubecek

Powered by blists - more mailing lists