Mapping LDAP group to user roles

Mapping LDAP group to user roles

[Tom Joseph]

Hello,

We have a requirement to assign role to the LDAP users, so certain 
operations can be restricted for users without admin permissions.

The proposal is to assign role for the LDAP groups. The LDAP user will 
inherit the role assigned to the LDAP group.
To start off the plan is to have two roles, the admin role and the user 
role. The role will be consumed by the
phosphor-rest-server and screen the REST api based on HTTP verbs.The 
user role will permit only REST API's with GET verb.
The admin role will permit all the HTTP verbs.

With this in background, i am proposing a D-Bus API to implement the 
LDAP group to role mapping. The CreateGroupRole method
can be used to create a mapping between the LDAP group and the role. 
This will create the object with the group name like
/xyx/openbmc_project/ldap/<group_name> which will implement the 
GroupEntry interface that has the role attribute.

Let me know the thoughts about this proposal.

https://gerrit.openbmc-project.xyz/#/c/openbmc/phosphor-dbus-interfaces/+/12027/

Regards,
Tom

RE: Mapping LDAP group to user roles

[Tanous, Ed]

> 
> We have a requirement to assign role to the LDAP users, so certain
> operations can be restricted for users without admin permissions.
> 

It would be great if you could document your proposal as a patch to the existing user management document here:
https://github.com/openbmc/docs/blob/master/user_management.md

It would make it much easier to see what changes you're proposing.  Given what already exists, your proposal is a little confusing, as there's already a mechanism to get group membership, and defined the user roles.  Are you proposing changing the existing interfaces to the new group collection type interface?  You're proposing two user roles, but we already have documented 4 user roles.  Is your proposal to delete two of them?

I think all of these questions would be answered if you could update the document above with your proposed changes.

Re: Mapping LDAP group to user roles

[Tom Joseph]

On Tuesday 21 August 2018 08:51 PM, Tanous, Ed wrote:
>> We have a requirement to assign role to the LDAP users, so certain
>> operations can be restricted for users without admin permissions.
>>
> It would be great if you could document your proposal as a patch to the existing user management document here:
> https://github.com/openbmc/docs/blob/master/user_management.md
https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>
> It would make it much easier to see what changes you're proposing.  Given what already exists, your proposal is a little confusing, as there's already a mechanism to get group membership, and defined the user roles.  Are you proposing changing the existing interfaces to the new group collection type interface?  You're proposing two user roles, but we already have documented 4 user roles.  Is your proposal to delete two of them?
>
> I think all of these questions would be answered if you could update the document above with your proposed changes.
In phosphor-rest-server the requirement is to add two privilege roles, 
the admin and the user role. So the interface has two roles proposed. 
This can be extended in the future to include other privilege roles.

RE: Mapping LDAP group to user roles

[Tanous, Ed]

> >>
> > It would be great if you could document your proposal as a patch to the
> existing user management document here:
> > https://github.com/openbmc/docs/blob/master/user_management.md
> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
> >

This is a great start, but a lot of detail seems to be missing.  You don't mention anything of the two user roles you mentioned in your original email.  Has that changed?  I don't see any mention of the dbus interface, has that changed?  I don't see that you've modified any of the login flows in the document, but the LDAP section talks about authorizing users via DBus, which certainly should include changes to the flow diagrams.

It would be great if you could take another pass at this, and see if you could add a little more detail to your proposal.

Thanks,

-Ed 

Re: Mapping LDAP group to user roles

[Tom Joseph]

On Thursday 23 August 2018 09:59 PM, Tanous, Ed wrote:
>>> It would be great if you could document your proposal as a patch to the
>> existing user management document here:
>>> https://github.com/openbmc/docs/blob/master/user_management.md
>> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
> This is a great start, but a lot of detail seems to be missing.  You don't mention anything of the two user roles you mentioned in your original email.  Has that changed?  I don't see any mention of the dbus interface, has that changed?  I don't see that you've modified any of the login flows in the document, but the LDAP section talks about authorizing users via DBus, which certainly should include changes to the flow diagrams.
Thanks Ed for the feedback. The D-Bus interface is updated to support 
all the privilege roles supported by OpenBMC. The document ha sonly the 
user creation flows. Richard mentioned he has the login flows updated in 
the downstream and he will upstream it. So I will update the 
authorization flow on top of  that.

Documentation:
https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/

D-Bus Interface:
https://gerrit.openbmc-project.xyz/#/c/openbmc/phosphor-dbus-interfaces/+/12027/
> It would be great if you could take another pass at this, and see if you could add a little more detail to your proposal.
>
> Thanks,
>
> -Ed

Re: Mapping LDAP group to user roles

[Thomaiyar, Richard Marian]

Ed / Brad / Tom / Ratan,

1. REDFISH can't manage LDAP user accounts. i.e. It will be beyond the 
scope of REDFISH and won't list any LDAP user accounts (REDFISH can 
implement LDAP privilege mapping configuration though)  --> Agree?

2. Authentication must happen only using pam_authenticate (For security 
purpose), and for authorization can use

                 a). getgrnam_r to get the group & privilege

                 b). use D-Bus API get property to get the group & 
privilege role of the user

                 c). Maintain 1:1 mapping with application through 
signal handler to do user sync, which can be used directly (IPMI Code 
under review does this logic).

     Problem with option #a is it requires individual way to map group & 
privilege, hence it was not recommended, and suggestion was to use #b or 
#c. But with ldap user accounts #b & #c can't be used as there is no 
local user object and hence thinking about introducing a generic D-Bus 
API (under Manager) to return user Info say GetUserInfo --> which 
accepts user name as argument, and returns back groups & privilege of 
the user (irrespective of whether the user is local / ldap), in this way 
applications doesn't need to use different flow to query ldap / local 
user account information and can use one single flow?

Note: This method must be implemented, so that it can internally use the 
LDAP privilege mapper config to determine the privilege that has to be 
applied to user, and can pass supported groups as ssh, redfish & web (or 
can implement ldapGroupMapper too if needed).

Any thoughts about this flow?

Regards,

Richard


On 8/28/2018 8:25 PM, Tom Joseph wrote:
>
> On Thursday 23 August 2018 09:59 PM, Tanous, Ed wrote:
>>>> It would be great if you could document your proposal as a patch to 
>>>> the
>>> existing user management document here:
>>>> https://github.com/openbmc/docs/blob/master/user_management.md
>>> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>> This is a great start, but a lot of detail seems to be missing. You 
>> don't mention anything of the two user roles you mentioned in your 
>> original email.  Has that changed?  I don't see any mention of the 
>> dbus interface, has that changed?  I don't see that you've modified 
>> any of the login flows in the document, but the LDAP section talks 
>> about authorizing users via DBus, which certainly should include 
>> changes to the flow diagrams.
> Thanks Ed for the feedback. The D-Bus interface is updated to support 
> all the privilege roles supported by OpenBMC. The document ha sonly 
> the user creation flows. Richard mentioned he has the login flows 
> updated in the downstream and he will upstream it. So I will update 
> the authorization flow on top of  that.
>
> Documentation:
> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>
> D-Bus Interface:
> https://gerrit.openbmc-project.xyz/#/c/openbmc/phosphor-dbus-interfaces/+/12027/ 
>
>> It would be great if you could take another pass at this, and see if 
>> you could add a little more detail to your proposal.
>>
>> Thanks,
>>
>> -Ed
>

Re: Mapping LDAP group to user roles

[Ratan Gupta]

Hi Richard,

On Tuesday 28 August 2018 09:12 PM, Thomaiyar, Richard Marian wrote:
> Ed / Brad / Tom / Ratan,
>
> 1. REDFISH can't manage LDAP user accounts. i.e. It will be beyond the 
> scope of REDFISH and won't list any LDAP user accounts (REDFISH can 
> implement LDAP privilege mapping configuration though)  --> Agree?
I agree on it.
>
> 2. Authentication must happen only using pam_authenticate (For 
> security purpose), and for authorization can use
>
>                 a). getgrnam_r to get the group & privilege
>
>                 b). use D-Bus API get property to get the group & 
> privilege role of the user
>
>                 c). Maintain 1:1 mapping with application through 
> signal handler to do user sync, which can be used directly (IPMI Code 
> under review does this logic).
>
>     Problem with option #a is it requires individual way to map group 
> & privilege, hence it was not recommended, and suggestion was to use 
> #b or #c. But with ldap user accounts #b & #c can't be used as there 
> is no local user object and hence thinking about introducing a generic 
> D-Bus API (under Manager) to return user Info say GetUserInfo --> 
> which accepts user name as argument, and returns back groups & 
> privilege of the user (irrespective of whether the user is local / 
> ldap), in this way applications doesn't need to use different flow to 
> query ldap / local user account information and can use one single flow?
If I am getting it correctly that you proposed that implementation logic 
of getting the roles of user in the user manager interface by 
introducing the D-bus Method getUserInfo().

The flow for the getUserInfo() would be as follows

1) Check that the user is local and if local then get the role from the 
local user D-bus object.

2) if user is not local user(ldap user) then get the role through the 
group -- Role mapping.
        a) getgrnam_r will get the ldap user group name as the libc 
would be using the libnss_ldap
        b) once we have the group name then we can get the priviledge 
role for that ldap user via the D-bus API.

I agree with this proposal to put this logic inside the app which 
implements the manager interface.

I am wondering what the getUserInfo API would return as part of user 
info, Would it be

1) Group Name
2) Privilege

Should we include the UserEnabled and the UserAccountLockedState as part 
of user info? would it be useful?
I am asking as if user password has been expired or account locked or 
new password required would have been handled through pam account
management which is part of authentication.

What is your view on this?


Are you planning to implement the above D-bus api(GetUserInfo) or can we 
help here?
>
> Note: This method must be implemented, so that it can internally use 
> the LDAP privilege mapper config to determine the privilege that has 
> to be applied to user, and can pass supported groups as ssh, redfish & 
> web (or can implement ldapGroupMapper too if needed).
>
> Any thoughts about this flow?
>
> Regards,
>
> Richard
>
>
> On 8/28/2018 8:25 PM, Tom Joseph wrote:
>>
>> On Thursday 23 August 2018 09:59 PM, Tanous, Ed wrote:
>>>>> It would be great if you could document your proposal as a patch 
>>>>> to the
>>>> existing user management document here:
>>>>> https://github.com/openbmc/docs/blob/master/user_management.md
>>>> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>>> This is a great start, but a lot of detail seems to be missing. You 
>>> don't mention anything of the two user roles you mentioned in your 
>>> original email.  Has that changed?  I don't see any mention of the 
>>> dbus interface, has that changed?  I don't see that you've modified 
>>> any of the login flows in the document, but the LDAP section talks 
>>> about authorizing users via DBus, which certainly should include 
>>> changes to the flow diagrams.
>> Thanks Ed for the feedback. The D-Bus interface is updated to support 
>> all the privilege roles supported by OpenBMC. The document ha sonly 
>> the user creation flows. Richard mentioned he has the login flows 
>> updated in the downstream and he will upstream it. So I will update 
>> the authorization flow on top of that.
>>
>> Documentation:
>> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>>
>> D-Bus Interface:
>> https://gerrit.openbmc-project.xyz/#/c/openbmc/phosphor-dbus-interfaces/+/12027/ 
>>
>>> It would be great if you could take another pass at this, and see if 
>>> you could add a little more detail to your proposal.
>>>
>>> Thanks,
>>>
>>> -Ed
>>
>

Re: Mapping LDAP group to user roles

[Thomaiyar, Richard Marian]

On 8/29/2018 5:21 PM, Ratan Gupta wrote:
> Hi Richard,
>
> On Tuesday 28 August 2018 09:12 PM, Thomaiyar, Richard Marian wrote:
>> Ed / Brad / Tom / Ratan,
>>
>> 1. REDFISH can't manage LDAP user accounts. i.e. It will be beyond 
>> the scope of REDFISH and won't list any LDAP user accounts (REDFISH 
>> can implement LDAP privilege mapping configuration though)  --> Agree?
> I agree on it.
Had a discussion with Ed, and Ed agrees about the problem of listing all 
the LDAP user accounts. At the same time, he is thinking about listing 
out the Logged in LDAP user accounts?
Another interesting question which he raised was, how we are going to 
track this user in the security login logs, so that we will be able to 
trace back on which user performed what action?
(I have not yet investigated how to do this, but thought to share, so 
that you can also think about this).
>>
>> 2. Authentication must happen only using pam_authenticate (For 
>> security purpose), and for authorization can use
>>
>>                 a). getgrnam_r to get the group & privilege
>>
>>                 b). use D-Bus API get property to get the group & 
>> privilege role of the user
>>
>>                 c). Maintain 1:1 mapping with application through 
>> signal handler to do user sync, which can be used directly (IPMI Code 
>> under review does this logic).
>>
>>     Problem with option #a is it requires individual way to map group 
>> & privilege, hence it was not recommended, and suggestion was to use 
>> #b or #c. But with ldap user accounts #b & #c can't be used as there 
>> is no local user object and hence thinking about introducing a 
>> generic D-Bus API (under Manager) to return user Info say GetUserInfo 
>> --> which accepts user name as argument, and returns back groups & 
>> privilege of the user (irrespective of whether the user is local / 
>> ldap), in this way applications doesn't need to use different flow to 
>> query ldap / local user account information and can use one single flow?
> If I am getting it correctly that you proposed that implementation 
> logic of getting the roles of user in the user manager interface by 
> introducing the D-bus Method getUserInfo().
>
> The flow for the getUserInfo() would be as follows
>
> 1) Check that the user is local and if local then get the role from 
> the local user D-bus object.
>
> 2) if user is not local user(ldap user) then get the role through the 
> group -- Role mapping.
>        a) getgrnam_r will get the ldap user group name as the libc 
> would be using the libnss_ldap
>        b) once we have the group name then we can get the priviledge 
> role for that ldap user via the D-bus API.
>
> I agree with this proposal to put this logic inside the app which 
> implements the manager interface.
>
> I am wondering what the getUserInfo API would return as part of user 
> info, Would it be
>
> 1) Group Name
> 2) Privilege
>
> Should we include the UserEnabled and the UserAccountLockedState as 
> part of user info? would it be useful?
> I am asking as if user password has been expired or account locked or 
> new password required would have been handled through pam account
> management which is part of authentication.
>
I am not sure, whether we will be able to get the userEnabled and 
UserAccountLockedState from LDAP server, but if we are able to then i 
think we can list down those too. (along with one more param, as ldap / 
local user).
Also, Do you thought about how to determine whether the user is ldap / 
local ?  1. Are we going to check the <domain>/<username> as ldap ? 2. 
Any account which succeeds in pam_authenticate, and not in local user 
database is ldap user?
> What is your view on this?
>
>
> Are you planning to implement the above D-bus api(GetUserInfo) or can 
> we help here?
I am fine with either way, but my first priority is to merge existing 
code (clear out the backlog).

Regards,
Richard
>>
>> Note: This method must be implemented, so that it can internally use 
>> the LDAP privilege mapper config to determine the privilege that has 
>> to be applied to user, and can pass supported groups as ssh, redfish 
>> & web (or can implement ldapGroupMapper too if needed).
>>
>> Any thoughts about this flow?
>>
>> Regards,
>>
>> Richard
>>
>>
>> On 8/28/2018 8:25 PM, Tom Joseph wrote:
>>>
>>> On Thursday 23 August 2018 09:59 PM, Tanous, Ed wrote:
>>>>>> It would be great if you could document your proposal as a patch 
>>>>>> to the
>>>>> existing user management document here:
>>>>>> https://github.com/openbmc/docs/blob/master/user_management.md
>>>>> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>>>> This is a great start, but a lot of detail seems to be missing. You 
>>>> don't mention anything of the two user roles you mentioned in your 
>>>> original email.  Has that changed?  I don't see any mention of the 
>>>> dbus interface, has that changed?  I don't see that you've modified 
>>>> any of the login flows in the document, but the LDAP section talks 
>>>> about authorizing users via DBus, which certainly should include 
>>>> changes to the flow diagrams.
>>> Thanks Ed for the feedback. The D-Bus interface is updated to 
>>> support all the privilege roles supported by OpenBMC. The document 
>>> ha sonly the user creation flows. Richard mentioned he has the login 
>>> flows updated in the downstream and he will upstream it. So I will 
>>> update the authorization flow on top of that.
>>>
>>> Documentation:
>>> https://gerrit.openbmc-project.xyz/#/c/openbmc/docs/+/12091/
>>>
>>> D-Bus Interface:
>>> https://gerrit.openbmc-project.xyz/#/c/openbmc/phosphor-dbus-interfaces/+/12027/ 
>>>
>>>> It would be great if you could take another pass at this, and see 
>>>> if you could add a little more detail to your proposal.
>>>>
>>>> Thanks,
>>>>
>>>> -Ed
>>>
>>
>