Eric Lee / smarc-ti-linux-kernel

09 Jan, 2006

1 commit

  • b5f545c88   [PATCH] keys: Permit running process to instantiate keys ... Browse Code »

    Make it possible for a running process (such as gssapid) to be able to
    instantiate a key, as was requested by Trond Myklebust for NFS4.

    The patch makes the following changes:

    (1) A new, optional key type method has been added. This permits a key type
    to intercept requests at the point /sbin/request-key is about to be
    spawned and do something else with them - passing them over the
    rpc_pipefs files or netlink sockets for instance.

    The uninstantiated key, the authorisation key and the intended operation
    name are passed to the method.

    (2) The callout_info is no longer passed as an argument to /sbin/request-key
    to prevent unauthorised viewing of this data using ps or by looking in
    /proc/pid/cmdline.

    This means that the old /sbin/request-key program will not work with the
    patched kernel as it will expect to see an extra argument that is no
    longer there.

    A revised keyutils package will be made available tomorrow.

    (3) The callout_info is now attached to the authorisation key. Reading this
    key will retrieve the information.

    (4) A new field has been added to the task_struct. This holds the
    authorisation key currently active for a thread. Searches now look here
    for the caller's set of keys rather than looking for an auth key in the
    lowest level of the session keyring.

    This permits a thread to be servicing multiple requests at once and to
    switch between them. Note that this is per-thread, not per-process, and
    so is usable in multithreaded programs.

    The setting of this field is inherited across fork and exec.

    (5) A new keyctl function (KEYCTL_ASSUME_AUTHORITY) has been added that
    permits a thread to assume the authority to deal with an uninstantiated
    key. Assumption is only permitted if the authorisation key associated
    with the uninstantiated key is somewhere in the thread's keyrings.

    This function can also clear the assumption.

    (6) A new magic key specifier has been added to refer to the currently
    assumed authorisation key (KEY_SPEC_REQKEY_AUTH_KEY).

    (7) Instantiation will only proceed if the appropriate authorisation key is
    assumed first. The assumed authorisation key is discarded if
    instantiation is successful.

    (8) key_validate() is moved from the file of request_key functions to the
    file of permissions functions.

    (9) The documentation is updated.

    From:

    Build fix.

    Signed-off-by: David Howells
    Cc: Trond Myklebust
    Cc: Alexander Zangerl
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Howells
     

09 Oct, 2005

1 commit