linux/include/keys
David Howells a511e1af8b KEYS: Move the point of trust determination to __key_link()
Move the point at which a key is determined to be trustworthy to
__key_link() so that we use the contents of the keyring being linked in to
to determine whether the key being linked in is trusted or not.

What is 'trusted' then becomes a matter of what's in the keyring.

Currently, the test is done when the key is parsed, but given that at that
point we can only sensibly refer to the contents of the system trusted
keyring, we can only use that as the basis for working out the
trustworthiness of a new key.

With this change, a trusted keyring is a set of keys that once the
trusted-only flag is set cannot be added to except by verification through
one of the contained keys.

Further, adding a key into a trusted keyring, whilst it might grant
trustworthiness in the context of that keyring, does not automatically
grant trustworthiness in the context of a second keyring to which it could
be secondarily linked.

To accomplish this, the authentication data associated with the key source
must now be retained.  For an X.509 cert, this means the contents of the
AuthorityKeyIdentifier and the signature data.


If system keyrings are disabled then restrict_link_by_builtin_trusted()
resolves to restrict_link_reject().  The integrity digital signature code
still works correctly with this as it was previously using
KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there
is no system keyring against which trust can be determined.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:43:43 +01:00
..
asymmetric-parser.h KEYS: Asymmetric key pluggable data parsers 2012-10-08 13:50:13 +10:30
asymmetric-subtype.h KEYS: Allow authentication data to be stored in an asymmetric key 2016-04-06 16:13:33 +01:00
asymmetric-type.h KEYS: Generalise x509_request_asymmetric_key() 2016-04-11 22:41:56 +01:00
big_key-type.h KEYS: big_key: Use key preparsing 2014-07-22 21:46:47 +01:00
ceph-type.h libceph: Create a new key type "ceph". 2011-03-29 12:11:24 -07:00
dns_resolver-type.h DNS: Separate out CIFS DNS Resolver code 2010-08-05 17:17:51 +00:00
encrypted-type.h encrypted-keys: add key format support 2011-06-27 09:10:45 -04:00
keyring-type.h KEYS: Expand the capacity of a keyring 2013-09-24 10:35:18 +01:00
rxrpc-type.h RxRPC: Fix v1 keys 2011-03-02 22:18:53 -08:00
system_keyring.h KEYS: Move the point of trust determination to __key_link() 2016-04-11 22:43:43 +01:00
trusted-type.h tpm: fix checks for policy digest existence in tpm2_seal_trusted() 2016-02-10 04:10:55 +02:00
user-type.h KEYS: Merge the type-specific data with the payload data 2015-10-21 15:18:36 +01:00