Messages in this thread | | | Date | Mon, 9 Jun 2014 17:06:02 +0300 | Subject | Re: [RFC PATCH v5 4/4] KEYS: define an owner trusted keyring | From | Dmitry Kasatkin <> |
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On 9 June 2014 16:58, Dmitry Kasatkin <dmitry.kasatkin@gmail.com> wrote: > On 9 June 2014 16:48, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote: >> On Mon, 2014-06-09 at 16:05 +0300, Dmitry Kasatkin wrote: >>> On 09/06/14 15:51, Mimi Zohar wrote: >>> > On Mon, 2014-06-09 at 15:13 +0300, Dmitry Kasatkin wrote: >>> >> On 03/06/14 20:58, Mimi Zohar wrote: >>> >>> Instead of allowing public keys, with certificates signed by any >>> >>> key on the system trusted keyring, to be added to a trusted >>> >>> keyring, this patch further restricts the certificates to those >>> >>> signed by a particular key on the system keyring. >>> >>> >>> >>> When the UEFI secure boot keys are added to the system keyring, the >>> >>> platform owner will be able to load their key in one of the UEFI DBs >>> >>> (eg. Machine Owner Key(MOK) list) and select their key, without >>> >>> having to rebuild the kernel. >>> >>> >>> >>> This patch defines an owner trusted keyring, a new boot command >>> >>> line option 'keys_ownerid=', and defines a new function >>> >>> get_system_or_owner_trusted_keyring(). >>> >> Hello, >>> >> >>> >> The functionality of this entire patch can be replaced by only ~2 lines >>> >> of code in x509_request_asymmetric_key() >>> >> >>> >> if (keys_ownerid || strcmp(keys_ownerid, id)) >>> >> return -EPERM; >>> >> >>> >> Right? >>> > Are you suggesting only add the one matching key to the system keyring? >>> >>> No. I am not suggesting this. >>> >>> All built in keys are allocated with KEY_ALLOC_TRUSTED flag and >>> prep.trusted is set to "true". >>> >>> So the following statement has no effect. >> >> Ok, so it has no affect on adding builtin keys to the system keyring. >> >>> >>> #ifdef CONFIG_SYSTEM_TRUSTED_KEYRING >>> ret = x509_validate_trust(cert, system_trusted_keyring); >>> if (!ret) >>> prep->trusted = 1; >>> #endif >> >> The last patch set changes the test to: >> ret = x509_validate_trust(cert, get_system_or_owner_trusted_keyring()); >> > > It does not really mater. I just copied original code to my response. > >>> Keys which come from user-space will check for >>> >>> if (keys_ownerid && strcmp(keys_ownerid, id)) >>> return -EPERM; >>> >>> >>> So 2 lines patch works fine.. >> >> It works based on the assumption, that you would ever only want a single >> key on the 'owner' keyring, which is probably not the case. >> > > There is no any assumption here. I am discussing functionality of this patch. > That is exactly what this patch does - loads single key on the owners keyring. > > There is no need for additional keyring for a single key. That is just > enough to limit verification to the owners key id. > > - Dmitry > >
There is no reason to have advanced bloated implementation for unsure, may be never coming use-cases.
It is always very easy to make new patches for the future cases.
- Dmitry
>> Mimi >>
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