[PATCH 1/3] KEYS: DigitalSignature link restriction

[Eric Snowberg]

> On May 10, 2023, at 4:34 PM, Jarkko Sakkinen <jarkko at kernel.org> wrote:
> 
> On Tue May 9, 2023 at 1:07 AM EEST, Eric Snowberg wrote:
>> Add a new link restriction.  Restrict the addition of keys in a keyring
>> based on the key having digitalSignature usage set. Additionally, verify
>> the new certificate against the ones in the system keyrings.  Add two
>> additional functions to use the new restriction within either the builtin
>> or secondary keyrings.
>> 
>> Signed-off-by: Eric Snowberg <eric.snowberg at oracle.com>
>> ---
>> certs/system_keyring.c            | 52 +++++++++++++++++++++++++++++++
>> crypto/asymmetric_keys/restrict.c | 44 ++++++++++++++++++++++++++
>> include/crypto/public_key.h       | 11 +++++++
>> include/keys/system_keyring.h     | 11 +++++++
>> 4 files changed, 118 insertions(+)
>> 
>> diff --git a/certs/system_keyring.c b/certs/system_keyring.c
>> index a7a49b17ceb1..4249c49bd43b 100644
>> --- a/certs/system_keyring.c
>> +++ b/certs/system_keyring.c
>> @@ -51,6 +51,27 @@ int restrict_link_by_builtin_trusted(struct key *dest_keyring,
>> 					  builtin_trusted_keys);
>> }
>> 
>> +/**
>> + * restrict_link_by_digsig_builtin - Restrict digitalSignature key additions
>> + *   by the built-in keyring.
> 
> BTW, does checkpatch complain if you put that to a single line (I don't
> know this)?
> 
> If not, I would just put "Restrict by digitalSignature”

It looks like check patch will allow up to 100 chars.  I will update it to a single line.
Thanks.