Messages in this thread | | | Date | Mon, 7 Mar 2022 21:31:21 -0500 | Subject | Re: [PATCH 3/4] KEYS: CA link restriction | From | Stefan Berger <> |
| |
On 3/7/22 18:38, Eric Snowberg wrote: > > >> On Mar 7, 2022, at 4:01 PM, Mimi Zohar <zohar@linux.ibm.com> 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. > Isn't x509_cert_parse() being called as part of parsing the certificate? If so, it seems to check for a self-signed certificate every time. You could add something like the following to x509_check_for_self_signed(cert): pub->x509_self_signed = cert->self_signed = true;
This could then reduce the function in 3/4 to something like:
return payload->data[asym_crypto]->x509_self_signed;
Stefan
| |