From 008643b86c5f33c115c84ccdda1725cac3ad50ad Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:07:37 +0100 Subject: KEYS: Add a 'trusted' flag and a 'trusted only' flag Add KEY_FLAG_TRUSTED to indicate that a key either comes from a trusted source or had a cryptographic signature chain that led back to a trusted key the kernel already possessed. Add KEY_FLAGS_TRUSTED_ONLY to indicate that a keyring will only accept links to keys marked with KEY_FLAGS_TRUSTED. Signed-off-by: David Howells Reviewed-by: Kees Cook --- security/keys/key.c | 8 ++++++++ security/keys/keyring.c | 4 ++++ 2 files changed, 12 insertions(+) (limited to 'security/keys') diff --git a/security/keys/key.c b/security/keys/key.c index a819b5c7d4ec..d331ea9ef380 100644 --- a/security/keys/key.c +++ b/security/keys/key.c @@ -300,6 +300,8 @@ struct key *key_alloc(struct key_type *type, const char *desc, if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) key->flags |= 1 << KEY_FLAG_IN_QUOTA; + if (flags & KEY_ALLOC_TRUSTED) + key->flags |= 1 << KEY_FLAG_TRUSTED; memset(&key->type_data, 0, sizeof(key->type_data)); @@ -813,6 +815,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, prep.data = payload; prep.datalen = plen; prep.quotalen = index_key.type->def_datalen; + prep.trusted = flags & KEY_ALLOC_TRUSTED; if (index_key.type->preparse) { ret = index_key.type->preparse(&prep); if (ret < 0) { @@ -827,6 +830,11 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref, } index_key.desc_len = strlen(index_key.description); + key_ref = ERR_PTR(-EPERM); + if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags)) + goto error_free_prep; + flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0; + ret = __key_link_begin(keyring, &index_key, &edit); if (ret < 0) { key_ref = ERR_PTR(ret); diff --git a/security/keys/keyring.c b/security/keys/keyring.c index f7cdea22214f..9b6f6e09b50c 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1183,6 +1183,10 @@ int key_link(struct key *keyring, struct key *key) key_check(keyring); key_check(key); + if (test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags) && + !test_bit(KEY_FLAG_TRUSTED, &key->flags)) + return -EPERM; + ret = __key_link_begin(keyring, &key->index_key, &edit); if (ret == 0) { kdebug("begun {%d,%d}", keyring->serial, atomic_read(&keyring->usage)); -- cgit v1.2.1