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  PHC 
Open Source and information security mailing list archives
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Thu, 24 Mar 2016 15:47:41 +0300
From: Solar Designer <>
Subject: Re: [PHC] hash encryption

On Thu, Mar 24, 2016 at 03:29:34PM +0300, Solar Designer wrote:
> encoding the full length or full round+keylen as a 64-bit number.

... which has another drawback, besides code complexity: we'd be
exceeding one SHA-256 block with a likely typical key size of 32 bytes.
A maximum of 55 bytes fits in one SHA-256 block (if it's the only one,
so needs padding).  Currently, we have:

16+1+32 = 49

If encoding round+keylen as 64 bits:

16+8+32 = 56

This is one byte too much, resulting in a 2x slowdown.

So maybe we shouldn't encode the full keylen for that reason.  Maybe
encode round+keylen as 32-bit, or use the approach I had suggested (with
round number hashed in last).


Powered by blists - more mailing lists