code review request: 6894072: always refresh keytab
Valerie (Yu-Ching) Peng
valerie.peng at oracle.com
Sat Apr 9 00:33:53 UTC 2011
*src/share/classes/com/sun/security/auth/module/Krb5LoginModule.java*
*src/share/classes/javax/security/auth/kerberos/KerberosKey.java*
*src/share/classes/sun/misc/SharedSecrets.java*
*src/share/classes/sun/security/jgss/krb5/Krb5AcceptCredential.java
*=> All look fine.*
**src/share/classes/sun/security/jgss/krb5/Krb5Util.java*
=> 1) So, since when do we populate the Subject w/ Krb5AcceptCredential
objects? I thought only Krb5LoginModule would "write" the subject's
private cred set and I didn't find Krb5AcceptCredential objects added there.
224 Krb5AcceptCredential k5ac = SubjectComber.find(
225 subj, serverPrincipal, null, Krb5AcceptCredential.class);
=> 2) Inside the getKKeys() method, you refresh the set of KerberoKey
objects in the subject when the subject isn't read only. However, in
Krb5LoginModule, KerberosKey objects are only stored into the Subject's
private cred set when "storeKey" is true. Seems inconsistent?
271 public KerberosKey[] getKKeys() {
=> 3) I don't quite understand why there is a destroy() method that does
nothing... At a minimum, I'd expect we need to reset the fields, so that
they aren't usable or empty, right? Perhaps, we also need to destroy the
individual KeyTab and KerberosKey objects in the lists?
316 public void destroy() {
317 // Nothing to do now
318 }
||*src/share/classes/sun/security/jgss/krb5/SubjectComber.java
*
=> I wonder why do you add this? The previous impl only search for
publicly defined Kerberos objects, i.e. KerberosKey, KerberosTicket,
etc. I thought you said in previous email that we don't populate
Subject's private credential set w/ Krb5AcceptCredential objects?
100 credClass == Krb5AcceptCredential.class) {
*src/share/classes/sun/security/krb5/Config.java*
***src/share/classes/sun/security/krb5/EncryptionKey.java
**src/share/classes/sun/security/krb5/KrbAsRep.java
*=> All look fine
*
*||*src/share/classes/sun/security/krb5/KrbAsReqBuilder.java*
=> 1) This class does store its own copy of password, so shouldn't you
move the "does not" on line 49 to line 50?*
*
49 * This class *does not:*
50 * 1. Deal with real communications (KdcComm does it, and TGS-REQ)
51 * a. Name of KDCs for a realm
52 * b. Server availability, timeout, UDP or TCP
53 * d. KRB_ERR_RESPONSE_TOO_BIG
54 * 2. Stores its own copy of password, this means:
55 * a. Do not change/wipe it before Builder finish
56 * b. Builder will not wipe it for you
*
*I am still looking at the rest of changes, just want to send what I
have now, so you don't wait too long.
Thanks,
Valerie
*
*On 04/02/11 02:18 AM, Weijun Wang wrote:
> Updated again:
>
> http://cr.openjdk.java.net/~weijun/6894072/webrev.05/
>
> Changes:
>
> 1. New Krb5Util.KeysFromKeyTab as a special kind of KerebrosKey we
> will add to and remove from private credentials set. Add and remove
> are only done when !subject.isReadOnly(). Only remove keys for this
> principal.
>
> 2. Use the class above in KeyTab.getKeys().
>
> 3. Remove a uselss method in KDC.java test.
>
> 4. Update new test KeyTabCompat.java, make sure after keytab refresh,
> the old key in priv cred set is removed.
>
> Thanks
> Max
>
>
>
> On 04/02/2011 03:02 AM, Valerie (Yu-Ching) Peng wrote:
>> I think we need to clean up the old ones if we added it there.
>> Conceptually, this would fit closer w/ the "dynamic key tab" support.
>> One straightforward way for us to do this is to subclass KerberosKey
>> class and then we can remove all KerberosKey objects which are
>> implemented using this class at refresh time.
>> Just an idea.
>> Valerie
>>
>> On 04/01/11 02:14 AM, Weijun Wang wrote:
>>> Hi Valerie
>>>
>>> Updated again:
>>>
>>> http://cr.openjdk.java.net/~weijun/6894072/webrev.04/
>>>
>>> 1. KeyTab can be used by anyone
>>> 2. The two compatibility support
>>>
>>> As for adding keys (from keytab) into private credentials set, I
>>> haven't cleaned up old ones. Since it's a set, this means if old keys
>>> are removed from the keytab, they stay in the set. The set is never
>>> really used by our code, so I think it's harmless. I really don't know
>>> how to clean up. Remove all keys for this principal? But we do this
>>> because we want to keep compatibility and worry about people directly
>>> manipulating the set, and I cannot predict what they will do with the
>>> set.
>>>
>>> Thanks
>>> Max
>>>
>>>
>>> On 04/01/2011 10:23 AM, Weijun Wang wrote:
>>>>
>>>>
>>>> On 04/01/2011 10:09 AM, Valerie (Yu-Ching) Peng wrote:
>>>>> Max,
>>>>>
>>>>> I like this new approach of yours better.
>>>>> As for compatibility, you mentioned only one aspect, i.e. apps which
>>>>> put
>>>>> KerberosKeys inside a subject's private cred set.
>>>>> There is also a possibility that apps may read the subject's private
>>>>> credentials set for KerberosKeys that we used to put in and they
>>>>> won't
>>>>> find the keys anymore since it's the KeyTab objects that we put into
>>>>> the
>>>>> private cred set after this dynamic keytab support. Thoughts?
>>>>
>>>> No, I haven't thought about it.
>>>>
>>>> We can put a snapshot of keys there at the beginning and refresh them
>>>> whenever a getKeys() is called. This should be harmless because we
>>>> don't
>>>> really use the keys if keytab objects (not keytab files) exist. I
>>>> can do
>>>> that.
>>>>
>>>> Thanks
>>>> Max
>>>>
>>>>
>>>>>
>>>>> Valerie
>>>>>
>>>>>
>>>>> On 03/31/11 03:41 AM, Weijun Wang wrote:
>>>>>> Hi Valerie
>>>>>>
>>>>>> Sorry for the late reply. I've considered some alternatives.
>>>>>>
>>>>>> A "to-be-resolved" KerberosKey is quite difficult. When it's
>>>>>> resolved,
>>>>>> we have a list of keys with different etypes as the private
>>>>>> credentials. If it's not resolved, we can only create one, whose
>>>>>> encoding and etype are both unresolved, and when it finally gets
>>>>>> resolved, it's resolved into multiple keys. Also, there was a simple
>>>>>> mapping between KerberosKey and EncryptionKey. The resolving process
>>>>>> is not always at the same time as the mapping (converting from
>>>>>> one to
>>>>>> another) time, so it seems EncryptionKey might also needs to be
>>>>>> unresolved.
>>>>>>
>>>>>> Another solution is to revert back to my original KeyTab without an
>>>>>> intended user. This means several changes:
>>>>>>
>>>>>> In my latest version of ServiceCreds, there were multiple keys and
>>>>>> *one* keytab, now we also need multiple keytabs, because there might
>>>>>> be multiple keytabs in the subject's private credentials set and we
>>>>>> cannot tell which is for who. Therefore we collect all of them, when
>>>>>> the keys are needed at AP-REP time, we call getKeys() on all of
>>>>>> them,
>>>>>> and return the combination. Hopefully there won't be two keys for
>>>>>> the
>>>>>> same principal with same kvno and same etype. I regard that as an
>>>>>> abuse.
>>>>>>
>>>>>> Currently when there is no serverPrincipal specified in the
>>>>>> Krb5AcceptCredential construction, we pick a KerberosKey from the
>>>>>> private credentials set and use the KerberosPrincipal info
>>>>>> inside, and
>>>>>> then get all KerberosKeys for the same principal. We have never
>>>>>> really
>>>>>> looked at any KerberosPrincipal objects in the subject's principal
>>>>>> set. I had tried to do the same to KeyTabs in my webrev.02. Now this
>>>>>> will have a big change: the first step is always finding a
>>>>>> KerberosPrincipal in the principal sets first. If serverPrincipal is
>>>>>> specified, we find a matched one, otherwise, we just pick one and
>>>>>> use
>>>>>> it. And then, from the private credentials set, we fetch all
>>>>>> KerberosKeys for this principal and all KeyTabs.
>>>>>>
>>>>>> I think this is the correct way to go. Of course, for compatibility
>>>>>> reason, we assume there are third party codes that put KerberosKeys
>>>>>> inside a subject's private credentials set but hasn't put any
>>>>>> KerberosPrincipal there. Our Krb5LoginModule will never do it,
>>>>>> but we
>>>>>> can accept it.
>>>>>>
>>>>>> Here is a partial webrev:
>>>>>>
>>>>>> http://cr.openjdk.java.net/~weijun/6894072/webrev.03
>>>>>>
>>>>>> It only contains changes for Krb5Util.java, and hasn't included the
>>>>>> compatibility codes I mentioned above. As you can see, the KeyTab
>>>>>> objects are now retrieved by
>>>>>>
>>>>>> + sc.ktabs = SubjectComber.findMany(
>>>>>> + subj, null, null, KeyTab.class);
>>>>>>
>>>>>> so no principal name is used, and we retrive "many".
>>>>>>
>>>>>> If you think this is OK, I'll clean up other codes. One benefit is
>>>>>> that we don't need to update CCC with this solution. Yes we do
>>>>>> introduce new hashCode/equals/toString methods, but I think they do
>>>>>> not deserve a CCC.
>>>>>>
>>>>>> Thanks
>>>>>> Max
>>>>>>
>>>>>>
>>>>>> On 03/26/2011 08:20 AM, Valerie (Yu-Ching) Peng wrote:
>>>>>>> Max,
>>>>>>>
>>>>>>> Well, I find it a bit awkward that the KeyTab class has to have the
>>>>>>> KerberosPrincipal info which "intends" to use it.
>>>>>>> Have you considered a different approach like:
>>>>>>> Instead of adding the whole KeyTab object into the Subject's
>>>>>>> private
>>>>>>> credential set, we add a "to-be-resolved" KerberosKey object.
>>>>>>> When we
>>>>>>> need to use this kind of key, we'd check the associated KeyTab
>>>>>>> object to
>>>>>>> re-fresh its value if needed. This approach is conceptually
>>>>>>> closer to
>>>>>>> what we had and the changes aren't as dramatic and seems to meet
>>>>>>> the
>>>>>>> need required by 6894072.
>>>>>>>
>>>>>>> I'll continue to review your webrev, but just want to kick this
>>>>>>> idea
>>>>>>> off
>>>>>>> w/ you and see if it may work.
>>>>>>> Valerie
>>>>>>>
>>>>>>> On 03/23/11 02:00 AM, Weijun Wang wrote:
>>>>>>>> Hi Valerie
>>>>>>>>
>>>>>>>> Updated webrev:
>>>>>>>>
>>>>>>>> http://cr.openjdk.java.net/~weijun/6894072/webrev.02
>>>>>>>>
>>>>>>>> Changes since last version:
>>>>>>>>
>>>>>>>> 1. A KerberosPrincipal inside javax..KeyTab class. New
>>>>>>>> getInstance()
>>>>>>>> arguments, new getPrincipal() method.
>>>>>>>>
>>>>>>>> It can only be non-null now, but I didn't say anything in the
>>>>>>>> spec.
>>>>>>>> I'm hoping it can be null in the future to support multiple
>>>>>>>> service
>>>>>>>> principal in a single service.
>>>>>>>>
>>>>>>>> 2. toString(), hashCode(), equals() for KeyTab, since it will
>>>>>>>> be put
>>>>>>>> inside private credentials set.
>>>>>>>>
>>>>>>>> 3. Enhancement to SubjectComber:
>>>>>>>> a) Generics for find() and findMany()
>>>>>>>> b) findAux() now support Krb5AcceptCredential
>>>>>>>>
>>>>>>>> 4. Krb5Util.ServiceCreds: since principal is already inside both
>>>>>>>> KeyTab and KerberosKey, no more KerberosPrincipal argument in
>>>>>>>> getInstance(), there is still a field inside to save the value.
>>>>>>>>
>>>>>>>> 5. sun..KeyTab and javax..KeyTab: isMissing==true is now valid.
>>>>>>>> Changes to the javadoc of javax..KeyTab.getKeys().
>>>>>>>>
>>>>>>>> 6. New TwoPrinces.java test, a subject with 2 KerberosPrincipal
>>>>>>>> after
>>>>>>>> JAAS commit.
>>>>>>>>
>>>>>>>> This time I'd like to first make sure implementation is
>>>>>>>> correct, and
>>>>>>>> then I'll update the CCC. Is this OK?
>>>>>>>>
>>>>>>>> Thanks
>>>>>>>> Max
>>>>>>>
>>>>>
>>
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