diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/keys-request-key.txt | 9 | ||||
| -rw-r--r-- | Documentation/keys.txt | 28 |
2 files changed, 29 insertions, 8 deletions
diff --git a/Documentation/keys-request-key.txt b/Documentation/keys-request-key.txt index 09b55e461740..69686ad12c66 100644 --- a/Documentation/keys-request-key.txt +++ b/Documentation/keys-request-key.txt @@ -127,14 +127,15 @@ This is because process A's keyrings can't simply be attached to of them, and (b) it requires the same UID/GID/Groups all the way through. -====================== -NEGATIVE INSTANTIATION -====================== +==================================== +NEGATIVE INSTANTIATION AND REJECTION +==================================== Rather than instantiating a key, it is possible for the possessor of an authorisation key to negatively instantiate a key that's under construction. This is a short duration placeholder that causes any attempt at re-requesting -the key whilst it exists to fail with error ENOKEY. +the key whilst it exists to fail with error ENOKEY if negated or the specified +error if rejected. This is provided to prevent excessive repeated spawning of /sbin/request-key processes for a key that will never be obtainable. diff --git a/Documentation/keys.txt b/Documentation/keys.txt index e4dbbdb1bd96..6523a9e6f293 100644 --- a/Documentation/keys.txt +++ b/Documentation/keys.txt @@ -637,6 +637,9 @@ The keyctl syscall functions are: long keyctl(KEYCTL_INSTANTIATE, key_serial_t key, const void *payload, size_t plen, key_serial_t keyring); + long keyctl(KEYCTL_INSTANTIATE_IOV, key_serial_t key, + const struct iovec *payload_iov, unsigned ioc, + key_serial_t keyring); If the kernel calls back to userspace to complete the instantiation of a key, userspace should use this call to supply data for the key before the @@ -652,11 +655,16 @@ The keyctl syscall functions are: The payload and plen arguments describe the payload data as for add_key(). + The payload_iov and ioc arguments describe the payload data in an iovec + array instead of a single buffer. + (*) Negatively instantiate a partially constructed key. long keyctl(KEYCTL_NEGATE, key_serial_t key, unsigned timeout, key_serial_t keyring); + long keyctl(KEYCTL_REJECT, key_serial_t key, + unsigned timeout, unsigned error, key_serial_t keyring); If the kernel calls back to userspace to complete the instantiation of a key, userspace should use this call mark the key as negative before the @@ -669,6 +677,10 @@ The keyctl syscall functions are: that keyring, however all the constraints applying in KEYCTL_LINK apply in this case too. + If the key is rejected, future searches for it will return the specified + error code until the rejected key expires. Negating the key is the same + as rejecting the key with ENOKEY as the error code. + (*) Set the default request-key destination keyring. @@ -1062,6 +1074,13 @@ The structure has a number of fields, some of which are mandatory: viable. + (*) int (*vet_description)(const char *description); + + This optional method is called to vet a key description. If the key type + doesn't approve of the key description, it may return an error, otherwise + it should return 0. + + (*) int (*instantiate)(struct key *key, const void *data, size_t datalen); This method is called to attach a payload to a key during construction. @@ -1231,10 +1250,11 @@ hand the request off to (perhaps a path held in placed in another key by, for example, the KDE desktop manager). The program (or whatever it calls) should finish construction of the key by -calling KEYCTL_INSTANTIATE, which also permits it to cache the key in one of -the keyrings (probably the session ring) before returning. Alternatively, the -key can be marked as negative with KEYCTL_NEGATE; this also permits the key to -be cached in one of the keyrings. +calling KEYCTL_INSTANTIATE or KEYCTL_INSTANTIATE_IOV, which also permits it to +cache the key in one of the keyrings (probably the session ring) before +returning. Alternatively, the key can be marked as negative with KEYCTL_NEGATE +or KEYCTL_REJECT; this also permits the key to be cached in one of the +keyrings. If it returns with the key remaining in the unconstructed state, the key will be marked as being negative, it will be added to the session keyring, and an |