Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Gero Treuner
Hi all, On Mon, Apr 20, 2020 at 09:49:11PM +0100, Ian Collier wrote: > As Arnt has implied, the current method of generating the Message-ID > does not *guarantee* uniqueness; merely makes it highly improbable to > be non-unique. The thing is that we are not just concerned with other > instances o

Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Vincent Lefevre
On 2020-04-20 21:56:43 +0200, Arnt Gulbrandsen wrote: > I chose to hash in a similar situation. Basically I pass the entire message > through MD5 or another hash, then base64. > > A proper hash (even MD5) is indistinguishable from pure randomness if you > have no knowledge of the input, and hashin

Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Vincent Lefevre
On 2020-04-20 19:57:23 +0200, Gero Treuner wrote: > This is necessary to stay on the deterministic track: For this we > require that different Mutt instances use information which differs by > the pid and time/sequence number at some point, which is the data fed to > the hash algorithm. OK, that w

Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Vincent Lefevre
On 2020-04-20 21:49:11 +0100, Ian Collier wrote: > On Mon, Apr 20, 2020 at 07:08:07PM +0200, Gero Treuner wrote: > > The concern is that the inputs based on local and/or private information > > can be leaked. To achieve this the search space must be big enough. > [heavily snipped, of course] > > We

Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Ian Collier
On Tue, Apr 21, 2020 at 11:16:03PM +0200, Vincent Lefevre wrote: > This is a user-side problem. Users should make sure that their > hostname setting is unique (possibly with a very high probability, > assuming no attacks). See below. No. The hostname is what goes after the @ in your default email

Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Gero Treuner
On Tue, Apr 21, 2020 at 10:54:25PM +0200, Vincent Lefevre wrote: > On 2020-04-20 19:57:23 +0200, Gero Treuner wrote: > > This is necessary to stay on the deterministic track: For this we > > require that different Mutt instances use information which differs by > > the pid and time/sequence number

Re: [PATCH] Change Message-ID generation to be more unique and leak less information

2020-04-21 Thread Steffen Nurpmeso
Vincent Lefevre wrote in <20200421205425.gb838...@zira.vinc17.org>: |On 2020-04-20 19:57:23 +0200, Gero Treuner wrote: ... |> If we don't want to be deterministic, then I don't see a major advantage |> of hash functions compared to random data. | |In this case you need to make sure that such