Re: [PATCH RFC] kernel build: enable use of password-protected signing keys

Michal Marek
2014-02-13T10:21:57Z

On 2014-02-12 23:41, Emily Maier wrote:
> On 02/10/2014 08:51 AM, Michal Marek wrote:
>> On 9.2.2014 23:38, Emily Maier wrote:
>>> Currently, the module signing script assumes that the private key is
>>> not password-protected. This patch makes it slightly more secure by
>>> allowing it to be passed in on the command line as "make
>>> modules_install MOD_PASSWORD=abc". It's vulnerable to snooping during
>>> the build of course, but so is an unprotected signing key.
>>
>> The key's permissions can be set to 0600, while the make commandline is
>> visible in ps.
>
> Ok, I'll change it to that and look into other options as well. I think
> there may be a way to pass it to OpenSSL off disk and the command line
> entirely.
>
> Would it be appropriate to add Kconfig options for this or try to
> autodetect the password file?

What some vendors do is that they have the modules signed by a signing
machine that is separated from the build farm. So they typically unset
MODULE_SIG_ALL and handle the signing outside kbuild. The other option
is to have a wrapper for the openssl command, not sure if anybody is
doing that.

Michal