Re: agent-based framework for httpd private keys

[Kaspar Brand <ht...@velox.ch>]

On 07.02.2014 01:58, Daniel Kahn Gillmor wrote:
> As part of the goal of dropping encrypted private key support, have you
> considered using an agent-based framework for private keys?

I haven't, no, since an important aspect of that goal is to reduce
complexity in code. Dropping ssl_load_encrypted_pkey and friends from
trunk amounts to a reduction of about 5% of mod_ssl's ~15,000 LoC right now.

> Anyway, with some sort of agent-based approach, you could preserve
> encrypted keys-on-disk (for Joe Orton's examples of admins with access
> to full-machine backups, or secret-keys-on-NFS) while leaving apache
> agnostic about the way the keys get *into* the agent.

Putting the decrypted keys on a RAM disk (tmpfs etc.) is a much more
straightforward way to achieve this, IMO, with the benefit of being able
to rely on a well-established method for configuring private keys (and
not having to introduce another non-standard layer for performing
private key operations).

Kaspar

Re: agent-based framework for httpd private keys

[Reindl Harald <h....@thelounge.net>]

Am 09.02.2014 08:15, schrieb Kaspar Brand:
> On 07.02.2014 01:58, Daniel Kahn Gillmor wrote:
>> As part of the goal of dropping encrypted private key support, have you
>> considered using an agent-based framework for private keys?
> 
> I haven't, no, since an important aspect of that goal is to reduce
> complexity in code. Dropping ssl_load_encrypted_pkey and friends from
> trunk amounts to a reduction of about 5% of mod_ssl's ~15,000 LoC right now

may i notice as server-admin that i am not willing to run whatever agent
additional on headless machines and most admins out there do the same

first rule:  stop and disable anything
second rule: now enable the things you really need
third rule:  consider to replace software which pulls to much here

Re: agent-based framework for httpd private keys

[Daniel Kahn Gillmor <dk...@fifthhorseman.net>]

On Sun 2014-02-09 02:15:37 -0500, Kaspar Brand wrote:
> On 07.02.2014 01:58, Daniel Kahn Gillmor wrote:
>> As part of the goal of dropping encrypted private key support, have you
>> considered using an agent-based framework for private keys?
>
> I haven't, no, since an important aspect of that goal is to reduce
> complexity in code. Dropping ssl_load_encrypted_pkey and friends from
> trunk amounts to a reduction of about 5% of mod_ssl's ~15,000 LoC right now.
>
>> Anyway, with some sort of agent-based approach, you could preserve
>> encrypted keys-on-disk (for Joe Orton's examples of admins with access
>> to full-machine backups, or secret-keys-on-NFS) while leaving apache
>> agnostic about the way the keys get *into* the agent.
>
> Putting the decrypted keys on a RAM disk (tmpfs etc.) is a much more
> straightforward way to achieve this, IMO, with the benefit of being able
> to rely on a well-established method for configuring private keys (and
> not having to introduce another non-standard layer for performing
> private key operations).

i think an agent-based approach (using a secret-key-holding agent in a
separate memory space) would have prevented the exposure of long-term
secret keys in the recent heartbleed attack [0].

While i appreciate that enabling an agent would probably lead to some
code complexity, an agent-based approach does achieve stronger
protection in some contexts than decrypted keys on a RAM disk.

I don't have time to write a patch any time soon for this, but i just
wanted to highlight that i think the idea still has merit.

Regards,

      --dkg

[0] http://heartbleed.com/