It is question if we like:
nsUniqID = 0b0b7e53-957d11e3-a51dc0e5-9a05ecda
nsUniqID = 8ae4190d-957a11e3-a51dc0e5-9a05ecda
more than:
ipk11Label=meaningful_label+ipk11Private=TRUE
ipk11Label=meaningful_label+ipk11Private=FALSE
DNSSEC key metadata
-------------------
- Container (per-zone): cn=keys, idnsname=example.net, cn=dns
- Key metadata can be linked to key material via DN or ipk11Id.
- This allows key sharing between zones.
(DNSSEC-metadata will be specified later. That is not important for key
storage.)
Replica public keys
-------------------
- Container: cn=DNS,cn=<replica
FQDN>,cn=masters,cn=ipa,cn=etc,dc=example
- or it's child object like cn=wrappingKey
Master keys
-----------
- Container: cn=master, cn=keys, cn=sec, cn=dns, dc=example
- Single key = single object.
- We can use ipk11Label or ipk11Id for naming:
ipk11Label=dnssecMaster1, ipk11Label=dnssecMaster2, etc.
Work flows
==========
Read DNSSEC private key
-----------------------
1) read DNSSEC private key from LDAP
2) ipaWrappedKey objectClass is present - key is encrypted
3) read master key denoted by ipaWrappingKey attribute in DNSSEC
key object
4) use local replica key to decrypt master key
5) use decrypted master key to decrypt DNSSEC private key
Add DNSSEC private key
----------------------
1) use local replica key to decrypt master key
2) encrypt DNSSEC private key with master key
3) add ipaWrappingKey attribute pointing to master key
4) store encrypted blob in a new LDAP object
Add a replica
-------------
ipa-replica-prepare:
1) generate a new replica-key pair for the new replica
2) store key pair to replica-file (don't scream yet :-)
4) add public key for the new replica to LDAP
3) fetch master key from LDAP
4) encrypt master key with new replica public key
5) store resulting master key blob to LDAP
ipa-replica-install:
6) generate a new replica-key pair (!)
7) store new public key to LDAP
8) remove old public key (from replica-file) from LDAP
9) fetch master key
10) decrypt master key using old private key (from replica-file)
11) encrypt master key using new private key (generated locally)
12) replace old master key blob in LDAP with new blob (from step 11)
Delete a replica
----------------
This is the tricky part. New master key has to be generated on some
other
replica. What should we do if the ipa-replica-manage command was run on
deleted replica?
I propose to split replica master key roll-over to two phases:
Any machine in IPA domain (including to-be deleted replica):
1) Delete public key associated with replica from LDAP
2) Flip a bit in master key metadata and say "this key needs to be
re-generated"
(Maybe we can disable ipk11Wrap boolean to indicate that this key
should not be used for key wrapping.)
Remaining replicas:
3) Periodically check that master key is obsolete
4) Wait for (random period of time) to limit probability of collision
5) Check that master key is really obsolete and new one is not
present
6) Generate a new master key
7) Encrypt new master key with all replica-public-keys stored in LDAP
8) Store new master key blobs to a new LDAP object
(Conflicts are not a problem up to now because we are not
deleting old
key. In worst case, we will have multiple new master keys.)
*What should we do now?*
9) ??? Re-encrypt all DNSSEC keys with a new master key? (What if
we have
write conflict now?)
??? Let old keys there and wait until key rotation mechanism
replaces
all old DNSSEC keys with new DNSSEC keys encrypted with a new master
key (~
one year)?
10) Old master key can be deleted when no other object is
referencing to it.
Congratulations to people who reached this line and didn't skip
anything :-)
[0] http://www.freeipa.org/page/V4/PKCS11_in_LDAP/Schema
[1]
http://www.freeipa.org/page/V4/PKCS11_in_LDAP/Schema#Encoded_key_data_2
[2]
http://www.freeipa.org/page/V4/PKCS11_in_LDAP/Schema#FreeIPA_specifics_-_key_wrapping
[3]
http://www.freeipa.org/page/V4/PKCS11_in_LDAP/Schema#Storage_objects
