Login usecase

Aneela Saleem aneela at platalytics.com
Mon Jul 18 16:46:23 EDT 2016


Thanks Brandon and Todd,

I still have some confusions. Please guide me I'm just a beginner.

At the current stage I'm not implementing single-sign on. Here is the flow
of our application

Screenshotfrom2016-07-12171018.jpg
<https://drive.google.com/a/platalytics.com/file/d/0BytQ11DT_A8HUjhIcUU2bm1PSlU/view?usp=drivesdk>


User1 logged into our application through password based authentication.
After that when the user tries to access the Kerberized Hadoop cluster
it gets the authentication token from KDC, and the credential cache for
this user is stored on the client machine where the application is
running and user1 accesses the cluster.  Meanwhile another user (I.e.,
user2 ) logs into the application and tries to accesses the kerberized
cluster. Now when it gets the token from KDC, will the credentials of user1
be override by the user2's credentials? If so, then how to solve this
particular scenario? I'm not getting the clear idea

Thanks

On Monday, 18 July 2016, Todd Grayson <tgrayson at cloudera.com> wrote:

> (and I realize kerberos doesn't do groups)
>
> On Mon, Jul 18, 2016 at 12:05 PM, Todd Grayson <tgrayson at cloudera.com
> <javascript:_e(%7B%7D,'cvml','tgrayson at cloudera.com');>> wrote:
>
>> Aneela,
>>
>> HDFS supports the use of the \L lowercase "macro".  This is implemented
>> through the HDFS auth_to_local rules, it can be applied using the
>> additional rules if within the CDH.   The relationship for kebreros from
>> hadoop (for a major portion of the platform) traverses the java JGSS
>> implementation + hadoop security core classes. (Might be the better thread
>> to shift to if you need deeper discussion?)
>>
>> This is described in the apache hadoop upstream Jira HADOOP-10556
>>
>> But I agree discussion the approach on getting agreement on the structure
>> of username, uppercase/lowercase and group name in general is something to
>> be having.
>>
>>
>> On Mon, Jul 18, 2016 at 9:41 AM, Brandon Allbery <ballbery at sinenomine.net
>> <javascript:_e(%7B%7D,'cvml','ballbery at sinenomine.net');>> wrote:
>>
>>> While I can’t give you details, it sounds like you want to change the
>>> web application to use SPNEGO to do Kerberos authentication with a user;
>>> this gives you a credential that you can then use to authenticate to Hadoop.
>>>
>>> From: Aneela Saleem <aneela at platalytics.com
>>> <javascript:_e(%7B%7D,'cvml','aneela at platalytics.com');>>
>>> Date: Monday, July 18, 2016 at 11:13
>>> To: Brandon Allbery <ballbery at sinenomine.net
>>> <javascript:_e(%7B%7D,'cvml','ballbery at sinenomine.net');>>
>>> Cc: "kerberos at mit.edu <javascript:_e(%7B%7D,'cvml','kerberos at mit.edu');>"
>>> <kerberos at mit.edu <javascript:_e(%7B%7D,'cvml','kerberos at mit.edu');>>
>>> Subject: Re: Login usecase
>>>
>>> Thanks Brandon for your response.
>>>
>>> Actually, My use-case is that I have a web application that
>>> authenticates a user. Then user calls my backend services written in java
>>> to interact with hadoop cluster. My hadoop cluster is kerberos-enabled. I
>>> need to authenticate this user using my java code. I am able to login using
>>> keytab files, but i did not get someway to login using password. For
>>> logging in using keytab files, we need to place keytab files for all the
>>> system users on all the hosts from where we can access our hadoop cluster.
>>> So this is the main drawback. And as you say logging using keytab files is
>>> not appropriate then how can we achieve this objective?
>>>
>>> Thanks
>>>
>>> On Mon, Jul 18, 2016 at 7:45 PM, Brandon Allbery <
>>> ballbery at sinenomine.net
>>> <javascript:_e(%7B%7D,'cvml','ballbery at sinenomine.net');><mailto:
>>> ballbery at sinenomine.net
>>> <javascript:_e(%7B%7D,'cvml','ballbery at sinenomine.net');>>> wrote:
>>> You are going to have to describe what you are trying to do in more
>>> detail. Keytabs are not normally used for this purpose, except in the case
>>> of automated procedures (e.g. cron) that need to log in to a service as if
>>> they are a user. Perhaps you have confused keytabs (“passwords” on disk)
>>> with ccaches (ephemeral service credentials, which may or may not be on
>>> disk and typically expire in a relatively short time)?
>>>
>>> On 7/17/16, 16:04, "kerberos-bounces at mit.edu
>>> <javascript:_e(%7B%7D,'cvml','kerberos-bounces at mit.edu');><mailto:
>>> kerberos-bounces at mit.edu
>>> <javascript:_e(%7B%7D,'cvml','kerberos-bounces at mit.edu');>> on behalf
>>> of Aneela Saleem" <kerberos-bounces at mit.edu
>>> <javascript:_e(%7B%7D,'cvml','kerberos-bounces at mit.edu');><mailto:
>>> kerberos-bounces at mit.edu
>>> <javascript:_e(%7B%7D,'cvml','kerberos-bounces at mit.edu');>> on behalf
>>> of aneela at platalytics.com
>>> <javascript:_e(%7B%7D,'cvml','aneela at platalytics.com');><mailto:
>>> aneela at platalytics.com
>>> <javascript:_e(%7B%7D,'cvml','aneela at platalytics.com');>>> wrote:
>>>
>>>     Hi all,
>>>
>>>     If a user logs into any kerberized Application, using
>>> Krb5LoginModule,
>>>     there is a function loginFromKeyTab. Client should have the key tab
>>> file to
>>>     login to application. But I think this is very insecure way of login.
>>>     Anyone who cloud access your key tab file then login to application.
>>> Is
>>>     there any appropriate way to login to system. I don't understand How
>>> to do
>>>     this. I'm stuck
>>>
>>>     Thanks
>>>     ________________________________________________
>>>     Kerberos mailing list           Kerberos at mit.edu
>>> <javascript:_e(%7B%7D,'cvml','Kerberos at mit.edu');><mailto:
>>> Kerberos at mit.edu <javascript:_e(%7B%7D,'cvml','Kerberos at mit.edu');>>
>>>     https://mailman.mit.edu/mailman/listinfo/kerberos
>>>
>>>
>>> ________________________________________________
>>> Kerberos mailing list           Kerberos at mit.edu
>>> <javascript:_e(%7B%7D,'cvml','Kerberos at mit.edu');>
>>> https://mailman.mit.edu/mailman/listinfo/kerberos
>>>
>>
>>
>>
>> --
>> Todd Grayson
>> Business Operations Manager
>> Customer Operations Engineering
>> Security SME
>>
>>
>
>
> --
> Todd Grayson
> Business Operations Manager
> Customer Operations Engineering
> Security SME
>
>


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