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 <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
diff --git a/security/keys/key.c b/security/keys/key.c
index a819b5c..d331ea9 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -300,6 +300,8 @@
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 @@
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 @@
}
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);