Here are some patches to change the permissions model used by keys and
keyrings to be based on an ACL:
(1) Replace the permissions mask internally with an ACL that contains a
list of ACEs, each with a specific subject with a permissions mask.
Potted default ACLs are available for new keys and keyrings.
ACE subjects can be macroised to indicate the UID and GID specified on
the key (which remain). Future commits will be able to add additional
subject types, such as specific UIDs or domain tags/namespaces.
Also split a number of permissions to give finer control. Examples
include splitting the revocation permit from the change-attributes
permit, thereby allowing someone to be granted permission to revoke a
key without allowing them to change the owner; also the ability to
join a keyring is split from the ability to link to it, thereby
stopping a process accessing a keyring by joining it and thus
acquiring use of possessor permits.
(2) Provide a keyctl to allow the granting or denial of one or more
permits to a specific subject. Direct access to the ACL is not
granted, and the ACL cannot be viewed.
The patches can be found on the following branch:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-acl
David
---
David Howells (2):
KEYS: Replace uid/gid/perm permissions checking with an ACL
KEYS: Provide KEYCTL_GRANT_PERMISSION
certs/blacklist.c | 7
certs/system_keyring.c | 12 -
drivers/md/dm-crypt.c | 2
drivers/nvdimm/security.c | 2
fs/afs/security.c | 2
fs/cifs/cifs_spnego.c | 25 +
fs/cifs/cifsacl.c | 28 +-
fs/cifs/connect.c | 4
fs/crypto/keyinfo.c | 2
fs/ecryptfs/ecryptfs_kernel.h | 2
fs/ecryptfs/keystore.c | 2
fs/fscache/object-list.c | 2
fs/nfs/nfs4idmap.c | 30 +-
fs/ubifs/auth.c | 2
include/linux/key.h | 121 ++++---
include/uapi/linux/keyctl.h | 64 ++++
lib/digsig.c | 2
net/ceph/ceph_common.c | 2
net/dns_resolver/dns_key.c | 12 +
net/dns_resolver/dns_query.c | 15 +
net/rxrpc/key.c | 16 +
security/integrity/digsig.c | 31 +-
security/integrity/digsig_asymmetric.c | 2
security/integrity/evm/evm_crypto.c | 2
security/integrity/ima/ima_mok.c | 13 +
security/integrity/integrity.h | 4
.../integrity/platform_certs/platform_keyring.c | 13 +
security/keys/compat.c | 2
security/keys/encrypted-keys/encrypted.c | 2
security/keys/encrypted-keys/masterkey_trusted.c | 2
security/keys/gc.c | 2
security/keys/internal.h | 16 +
security/keys/key.c | 29 +-
security/keys/keyctl.c | 97 ++++-
security/keys/keyring.c | 27 +-
security/keys/permission.c | 356 ++++++++++++++++++--
security/keys/persistent.c | 27 +-
security/keys/proc.c | 20 +
security/keys/process_keys.c | 86 ++++-
security/keys/request_key.c | 34 +-
security/keys/request_key_auth.c | 15 +
security/selinux/hooks.c | 16 +
security/smack/smack_lsm.c | 3
43 files changed, 868 insertions(+), 285 deletions(-)
