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Date:   Sat, 22 Apr 2023 00:12:00 +0300
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Mimi Zohar <zohar@linux.ibm.com>
Cc:     Eric Snowberg <eric.snowberg@oracle.com>,
        David Howells <dhowells@redhat.com>,
        David Woodhouse <dwmw2@infradead.org>,
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        Kanth Ghatraju <kanth.ghatraju@oracle.com>,
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Subject: Re: [PATCH v5 5/6] KEYS: CA link restriction
Message-ID: <ZEL8IKYhMdOvpWa1@kernel.org>
References: <20230302164652.83571-1-eric.snowberg@oracle.com>
 <20230302164652.83571-6-eric.snowberg@oracle.com>
 <ZAz8QlynTSMD7kuE@kernel.org>
 <07FFED83-501D-418C-A4BB-862A547DD7B0@oracle.com>
 <20230320182822.6xyh6ibatrz5yrhb@kernel.org>
 <84d46fb108f6ce2a322b6486529fc6dd0f8deea5.camel@linux.ibm.com>
 <20230329232735.dvmxvwis2psbvyw5@kernel.org>
 <55b5c21ee1cf47aff0b2e5a94ec65fe326c8d6ba.camel@linux.ibm.com>
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On Thu, Mar 30, 2023 at 02:01:52AM -0400, Mimi Zohar wrote:
> On Thu, 2023-03-30 at 02:27 +0300, Jarkko Sakkinen wrote:
> > On Mon, Mar 20, 2023 at 04:35:33PM -0400, Mimi Zohar wrote:
> > > On Mon, 2023-03-20 at 20:28 +0200, Jarkko Sakkinen wrote:
> > > > On Mon, Mar 20, 2023 at 05:35:05PM +0000, Eric Snowberg wrote:
> > > > > 
> > > > > 
> > > > > > On Mar 11, 2023, at 3:10 PM, Jarkko Sakkinen <jarkko@kernel.org> wrote:
> > > > > > 
> > > > > > On Thu, Mar 02, 2023 at 11:46:51AM -0500, Eric Snowberg wrote:
> > > > > >> Add a new link restriction.  Restrict the addition of keys in a keyring
> > > > > >> based on the key to be added being a CA.
> > > > > >> 
> > > > > >> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
> > > > > >> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
> > > > > >> ---
> > > > > >> crypto/asymmetric_keys/restrict.c | 38 +++++++++++++++++++++++++++++++
> > > > > >> include/crypto/public_key.h       | 15 ++++++++++++
> > > > > >> 2 files changed, 53 insertions(+)
> > > > > >> 
> > > > > >> diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c
> > > > > >> index 6b1ac5f5896a..48457c6f33f9 100644
> > > > > >> --- a/crypto/asymmetric_keys/restrict.c
> > > > > >> +++ b/crypto/asymmetric_keys/restrict.c
> > > > > >> @@ -108,6 +108,44 @@ 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.
> > > > > >> + *
> > > > > >> + * Returns 0 if the new certificate was accepted, -ENOKEY if the
> > > > > >> + * certificate is not a CA. -ENOPKG if the signature uses unsupported
> > > > > >> + * crypto, or some other error if there is a matching certificate but
> > > > > >> + * the signature check cannot be performed.
> > > > > >> + */
> > > > > >> +int restrict_link_by_ca(struct key *dest_keyring,
> > > > > >> +			const struct key_type *type,
> > > > > >> +			const union key_payload *payload,
> > > > > >> +			struct key *trust_keyring)
> > > > > >> +{
> > > > > >> +	const struct public_key *pkey;
> > > > > >> +
> > > > > >> +	if (type != &key_type_asymmetric)
> > > > > >> +		return -EOPNOTSUPP;
> > > > > >> +
> > > > > >> +	pkey = payload->data[asym_crypto];
> > > > > >> +	if (!pkey)
> > > > > >> +		return -ENOPKG;
> > > > > >> +	if (!test_bit(KEY_EFLAG_CA, &pkey->key_eflags))
> > > > > >> +		return -ENOKEY;
> > > > > >> +	if (!test_bit(KEY_EFLAG_KEYCERTSIGN, &pkey->key_eflags))
> > > > > >> +		return -ENOKEY;
> > > > > >> +	if (test_bit(KEY_EFLAG_DIGITALSIG, &pkey->key_eflags))
> > > > > >> +		return -ENOKEY;
> > > > > > 
> > > > > > nit: would be more readable, if conditions were separated by
> > > > > > empty lines.
> > > > > 
> > > > > Ok, I will make this change in the next round.  Thanks.
> > > > 
> > > > Cool! Mimi have you tested these patches with IMA applied?
> > > 
> > > Yes, it's working as expected.
> > 
> > Thank you. Please check that I filled additional tags correctly:
> > 
> > https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/log/
> > 
> > I will then put these also to my 'next' branch and they will get mirrored
> > to linux-next.
> 
> Thanks, Jarkko.  The tags look good.

Hi, sorry for radio silence. I've been transitioning to a new job.

Commits are in my next branch, and I will include them to my PR.

BR, Jarkko