Commit Graph

5 Commits

Author SHA1 Message Date
David Howells
5d135440fa KEYS: Add garbage collection for dead, revoked and expired keys. [try #6]
Add garbage collection for dead, revoked and expired keys.  This involved
erasing all links to such keys from keyrings that point to them.  At that
point, the key will be deleted in the normal manner.

Keyrings from which garbage collection occurs are shrunk and their quota
consumption reduced as appropriate.

Dead keys (for which the key type has been removed) will be garbage collected
immediately.

Revoked and expired keys will hang around for a number of seconds, as set in
/proc/sys/kernel/keys/gc_delay before being automatically removed.  The default
is 5 minutes.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 21:29:11 +10:00
David Howells
0b77f5bfb4 keys: make the keyring quotas controllable through /proc/sys
Make the keyring quotas controllable through /proc/sys files:

 (*) /proc/sys/kernel/keys/root_maxkeys
     /proc/sys/kernel/keys/root_maxbytes

     Maximum number of keys that root may have and the maximum total number of
     bytes of data that root may have stored in those keys.

 (*) /proc/sys/kernel/keys/maxkeys
     /proc/sys/kernel/keys/maxbytes

     Maximum number of keys that each non-root user may have and the maximum
     total number of bytes of data that each of those users may have stored in
     their keys.

Also increase the quotas as a number of people have been complaining that it's
not big enough.  I'm not sure that it's big enough now either, but on the
other hand, it can now be set in /etc/sysctl.conf.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
David Howells
468ed2b0c8 [PATCH] Keys: Split key permissions checking into a .c file
The attached patch splits key permissions checking out of key-ui.h and
moves it into a .c file.  It's quite large and called quite a lot, and
it's about to get bigger with the addition of LSM support for keys...

key_any_permission() is also discarded as it's no longer used.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 14:53:31 -07:00
David Howells
3e30148c3d [PATCH] Keys: Make request-key create an authorisation key
The attached patch makes the following changes:

 (1) There's a new special key type called ".request_key_auth".

     This is an authorisation key for when one process requests a key and
     another process is started to construct it. This type of key cannot be
     created by the user; nor can it be requested by kernel services.

     Authorisation keys hold two references:

     (a) Each refers to a key being constructed. When the key being
     	 constructed is instantiated the authorisation key is revoked,
     	 rendering it of no further use.

     (b) The "authorising process". This is either:

     	 (i) the process that called request_key(), or:

     	 (ii) if the process that called request_key() itself had an
     	      authorisation key in its session keyring, then the authorising
     	      process referred to by that authorisation key will also be
     	      referred to by the new authorisation key.

	 This means that the process that initiated a chain of key requests
	 will authorise the lot of them, and will, by default, wind up with
	 the keys obtained from them in its keyrings.

 (2) request_key() creates an authorisation key which is then passed to
     /sbin/request-key in as part of a new session keyring.

 (3) When request_key() is searching for a key to hand back to the caller, if
     it comes across an authorisation key in the session keyring of the
     calling process, it will also search the keyrings of the process
     specified therein and it will use the specified process's credentials
     (fsuid, fsgid, groups) to do that rather than the calling process's
     credentials.

     This allows a process started by /sbin/request-key to find keys belonging
     to the authorising process.

 (4) A key can be read, even if the process executing KEYCTL_READ doesn't have
     direct read or search permission if that key is contained within the
     keyrings of a process specified by an authorisation key found within the
     calling process's session keyring, and is searchable using the
     credentials of the authorising process.

     This allows a process started by /sbin/request-key to read keys belonging
     to the authorising process.

 (5) The magic KEY_SPEC_*_KEYRING key IDs when passed to KEYCTL_INSTANTIATE or
     KEYCTL_NEGATE will specify a keyring of the authorising process, rather
     than the process doing the instantiation.

 (6) One of the process keyrings can be nominated as the default to which
     request_key() should attach new keys if not otherwise specified. This is
     done with KEYCTL_SET_REQKEY_KEYRING and one of the KEY_REQKEY_DEFL_*
     constants. The current setting can also be read using this call.

 (7) request_key() is partially interruptible. If it is waiting for another
     process to finish constructing a key, it can be interrupted. This permits
     a request-key cycle to be broken without recourse to rebooting.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-Off-By: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-24 00:05:19 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00