> On Mar 7, 2022, at 4:01 PM, Mimi Zohar <zohar@xxxxxxxxxxxxx> wrote: > > On Mon, 2022-03-07 at 18:06 +0000, Eric Snowberg wrote: >> >>>> diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c >>>> index 6b1ac5f5896a..49bb2ea7f609 100644 >>>> --- a/crypto/asymmetric_keys/restrict.c >>>> +++ b/crypto/asymmetric_keys/restrict.c >>>> @@ -108,6 +108,49 @@ int restrict_link_by_signature(struct key *dest_keyring, >>>> return ret; >>>> } >>>> +/** >>>> + * restrict_link_by_ca - Restrict additions to a ring of CA keys >>>> + * @dest_keyring: Keyring being linked to. >>>> + * @type: The type of key being added. >>>> + * @payload: The payload of the new key. >>>> + * @trust_keyring: Unused. >>>> + * >>>> + * Check if the new certificate is a CA. If it is a CA, then mark the new >>>> + * certificate as being ok to link. >>> >>> CA = root CA here, right? >> >> Yes, I’ll update the comment > > Updating the comment is not enough. There's an existing function named > "x509_check_for_self_signed()" which determines whether the certificate > is self-signed. Originally I tried using that function. However when the restrict link code is called, all the necessary x509 information is no longer available. The code in restrict_link_by_ca is basically doing the equivalent to x509_check_for_self_signed. After verifying the cert has the CA flag set, the call to public_key_verify_signature validates the cert is self signed.
