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Posted to user@shiro.apache.org by Maciej Pigulski <ma...@gmail.com> on 2009/04/01 08:33:20 UTC
Re: Reading user roles from Active Directory
Thanks Les, I'll try to put your advices into use.
Jeremy, I have no problem with creating a user with the read access,
but my client has:) As I mentioned in the first post JAAS configured
in jBoss doesn't require any additional users to perform such simple
task like checking users own groups so I was looking for same solution
in jSecurity.
>From my point of view (maybe this is a lazy developer point of view)
creating a separate user to only read permissions (groups) is a bit an
overkill. I understand when I need to edit LDAP tree or create users
for instance, but separate user to read for some other user that he has
a group X looks odd to me. What if I would like to have two users, one
with read access and one with write access? Create a user that can do
both as a system user and then I'd have to put those two users in
groups (such as 'read', 'write') and then check if they can read or write?
Maybe I'm exaggerating here, but my knowledge of security is not as
good as yours for sure.
Regards,
Maciej
Maciej, I'm curious - what is the difficulty in creating a system
user account that can be used to simply check authorization
information. This account could be granted read-only access that lets
it check on the roles and permissions that individual users have.
This is the way most of our LDAP/Active Directory users do this. You
mentioned wanting to avoid this because you created a powerful user,
but what if you only gave that user read only access and a secure
password that is only stored on your server (presumably in a secured
file)?
Jeremy
On Mar 31, 2009, at 2:37 AM, Maciej Pigulski wrote:
>
> Jeremy,
>
> you are absolutely right and I'm not proud at all from this
> solution, but it is the fastest implementation I've managed to get
> to work. I treat this as a temporary solution until jSecurity 1.0.
>
> Anyway, obviously I was doing something wrong while trying to make
> your solution working.
>
> I had problems with getting to Subjects session to store the
> authorization info - SecurityUtils.getSubject() was returning a null
> value. I guess the issue is that this object does not exist in this
> stage, but I couldn't get any other idea how to get into the Session
> object.
>
> Another issue was getting the AuthorizationInfo to work. Without
> setting systemUsername and systemPassword AuthorizationInfo was
> trying to obtain data from Active Directory with a null user and
> this failed. I think I should get this information using LdapContext
> (a new object, not the default one) with credentials passed by this
> user, but the queryForAuthorizationInfo uses
> getRoleNamesForUser(...) private method so I'd have to copy paste
> this method with LdapContext ldapContext =
> ldapContextFactory.getLdapContext(username, password); used instead
> the LdapContext ldapContext =
> ldapContextFactory.getSystemLdapContext(); one. This bugs me because
> when I'm copy-pasting then I'm doing something obviously wrong so I
> guess this way is not the correct way.
>
> Thanks for pointing me out possible issues with this solution. Now
> I'm getting worried ;)
>
> Maciej
>
>
>
> Marciej,
>
> This approach isn't the most secure since each time a new user
> authenticates, the system username and password will be updated to
> store their username and password.
>
> For example:
> 1) Bob logs in. His username/password are set as the system username/
> password
> 2) Bob does a permission check and it uses bob's account to access
> LDAP
> 3) Sue logs in. Her username/password are set as the system username/
> password
> 4) Bob does another permission check. this time Sue's credentials are
> used to access LDAP
>
> In this scenario, it's impossible to predict which user and password
> will be used to authenticate.
>
> Even neglecting the security implications, there is a possible race
> condition that could result in errors obtaining authorization
> information. Since DefaultLdapContextFactory is a singleton and is
> not synchronized in any way, it's possible that an authorization check
> will occur in one thread while in another thread the system username
> and password are being updated due to another user authenticating.
> This means that username could be set to "Sue" while the password is
> still set to Bob's password. This would result in an LDAP error since
> Bob's password is invalid for Sue's account.
>
> If you really want to just store the user's credentials, I would
> suggest storing them in the user's principal and pulling them out of
> the Principal object when you need to check for authorization info.
> That being said, holding onto a user's credentials in memory is
> considered a bad security practice, since if anyone hacks your machine
> or gets access to RAM, they could grab all of your user's
> credentials. Also, since the credentials would be stored in a
> session, and sessions are sometimes serialized to disk, a hacker could
> possible just get access to the serialized sessions file and obtain
> their credentials from the file.
>
> My 2 cents,
> Jeremy
>
> On Mar 30, 2009, at 10:43 AM, Maciej Pigulski wrote:
>
>>
>> Hello,
>>
>> thanks for the clarification. I've done it in a 3rd way by
>> overriding DefaultLdapContextFactory settings in
>> queryForAuthenticationInfo:
>>
>>
>> /* (non-Javadoc)
>> * @see
>> org
>> .jsecurity
>> .realm
>> .activedirectory
>> .ActiveDirectoryRealm
>> #queryForAuthenticationInfo(org.jsecurity.authc.AuthenticationToken,
>> org.jsecurity.realm.ldap.LdapContextFactory)
>> */
>> @Override
>> protected AuthenticationInfo
>> queryForAuthenticationInfo(AuthenticationToken token,
>> LdapContextFactory ldapContextFactory) throws NamingException {
>>
>> UsernamePasswordToken upToken = (UsernamePasswordToken) token;
>> DefaultLdapContextFactory defaultLdapContextFactory =
>> (DefaultLdapContextFactory) ldapContextFactory;
>> defaultLdapContextFactory.setSystemUsername(upToken.getUsername());
>>
>> defaultLdapContextFactory
>> .setSystemPassword(upToken.getPassword().toString());
>>
>> return super.queryForAuthenticationInfo(token, ldapContextFactory);
>> }
>>
>>
>> Maybe it is not the best workaround but I had no time to do it like
>> you suggested. Looking forward for jSecurity 1.0, keep up the good
>> work!
>>
>> Greetings,
>> Maciej
>>
>>
>> Maciej,
>>
>> The problem is that if the LDAP server requires credentials to login
>> (as they typically do), there is no way to obtain authorization
>> information at a later point without having a username/password to
>> login to the LDAP server. Due to the way JSecurity works,
>> authentication and authorization happen independently of each other,
>> and so when authorization occurs we do not have the username/password
>> that was originally used to authenticate (as we shouldn't).
>>
>> I think this brings to light an option that JSecurity should offer -
>> which is to allow authorization information to be obtained at login
>> and cached for the duration of a user's session. This is the way
>> many
>> security frameworks operate, and usually we tout the fact that
>> JSecurity doesn't work this way as an advantage (i.e. dynamic
>> security
>> updates, flexible caching, etc.)
>>
>> However - in this case it's a disadvantage because login is the only
>> time when we have the information we need to obtain the authorization
>> information (since the authentication info is needed to obtain
>> it). I
>> think there will be other scenarios where this is the case (external
>> authorization systems, SSO systems, etc.) so I do think JSecurity
>> should offer this mechanism as an option. I'll open a JIRA issue to
>> address this for the 1.0 release.
>>
>> As far as a short-term workaround, you could either:
>> 1) configure the system username and password for now (as I think
>> you've already done)
>> or
>> 2) extend the Active Directory realm, and override
>> queryForAuthenticationInfo to grab the AuthorizationInfo (similar to
>> how queryForAuthorizationInfo does) at login. You could then cache
>> the AuthorizationInfo in the subject's session and override
>> queryForAuthorizationInfo to return the session-cached authorization
>> information. This is similar to how JSecurity would probably do this
>> in the future, but obviously you'd have to manually implement it.
>>
>> Please let me know if you have any further questions or ideas!
>>
>> Jeremy
>>
>> On Mar 25, 2009, at 12:24 PM, Maciej Pigulski wrote:
>>
>>>
>>> Unfortunately this is still an issue to me.
>>>
>>>
>>> Jeremy or Tim, do you know if you'd be able to help out Maciej? I
>>> don't
>>> have any experience with the LDAP/AD stuff you guys wrote. Maciej,
>>> have
>>> you been able to work through this issue?
>>>
>>> On Thu, Mar 19, 2009 at 9:46 AM, Maciej Pigulski
>>> <ma...@gmail.com>wrote:
>>>
>>>>
>>>> Hello,
>>>>
>>>> I have a following problem with jSecurity, ActiveDirectoryRealm and
>>>> Groups
>>>> mappings.
>>>>
>>>> I have an AD setup on one server (WHEEL) with a simple user called
>>>> user1.
>>>> This user is in ldap group called
>>>> "login" (CN=login,OU=Groups,DC=WHEEL).
>>>>
>>>> Next I'm trying to login and retrieve roles for this user. Login
>>>> works fine
>>>> but when it comes to user roles I have to additionally provide
>>>> username
>>>> and
>>>> password in activeDirectoryRealm.setSystemUsername/Password. I've
>>>> found in
>>>> the API that it is a pretty normal behaviour (but IMHO very
>>>> inconvenient)
>>>> (
>>>> http://www.jsecurity.org/releases/0.9.0-beta2/docs/api/org/jsecurity/realm/ldap/DefaultLdapContextFactory.html#setSystemUsername(java.lang.String)
>>>> <http://www.jsecurity.org/releases/0.9.0-beta2/docs/api/org/jsecurity/realm/ldap/DefaultLdapContextFactory.html#setSystemUsername%28java.lang.String%29
>>>>>
>>>> :
>>>> <cite>
>>>> systemUsername - the username to use when logging into the LDAP
>>>> server for
>>>> authorization.
>>>> </cite>
>>>>
>>>> Is there any tricky way to bypass this? Setting same credentials on
>>>> two
>>>> objects to authorize and authenticate one user seems to be quite
>>>> wrong.
>>>>
>>>> I've managed to obtain this by creating a super user (with
>>>> enterprise
>>>> administrator rights) that has hardcoded username and password in
>>>> application (systemUsername and systemPassword) and this works for
>>>> authenticating other users but I'd like to avoid using such
>>>> powerfull user
>>>> just for groups fetching as it seems to be an huge overkill for me.
>>>>
>>>> Here is a class I'm using to test with AD:
>>>>
>>>> import java.util.HashMap;
>>>> import java.util.Map;
>>>>
>>>> import org.jsecurity.authc.UsernamePasswordToken;
>>>> import org.jsecurity.mgt.DefaultSecurityManager;
>>>> import org.jsecurity.realm.activedirectory.ActiveDirectoryRealm;
>>>> import org.jsecurity.subject.Subject;
>>>>
>>>> public class TestJSec {
>>>>
>>>> private DefaultSecurityManager securityManager = new
>>>> DefaultSecurityManager();
>>>> private ActiveDirectoryRealm activeDirectoryRealm = new
>>>> ActiveDirectoryRealm();
>>>>
>>>> public TestJSec() {
>>>> activeDirectoryRealm.setSearchBase("DC=WHEEL");
>>>> activeDirectoryRealm.setUrl("ldap://ldap-host:389");
>>>>
>>>> activeDirectoryRealm.setSystemUsername("user1@wheel"); //
>>>> if this is
>>>> missing user wont fetch his roles
>>>> activeDirectoryRealm.setSystemPassword("user1");
>>>> // if this
>>>> is missing user wont fetch his roles
>>>> Map<String, String> map = new HashMap<String,
>>>> String>();
>>>> map.put("CN=login,OU=Groups,DC=WHEEL", "login");
>>>> activeDirectoryRealm.setGroupRolesMap(map);
>>>>
>>>> securityManager.setRealm(activeDirectoryRealm);
>>>> }
>>>>
>>>> private void testLogin() {
>>>> UsernamePasswordToken userToken = new
>>>> UsernamePasswordToken("user1@wheel",
>>>> "user1");
>>>>
>>>> Subject subject = securityManager.login(userToken);
>>>> if (subject.hasRole("login")) {
>>>> System.out.println("User in role");
>>>> } else {
>>>> System.out.println("User has no role");
>>>> }
>>>> }
>>>>
>>>> public static void main(String[] args) {
>>>> TestJSec tjs = new TestJSec();
>>>> tjs.testLogin();
>>>> }
>>>> }
>>>>
>>>>
>>>> For example in jBoss this config works without a super user:
>>>>
>>>>
>>>> <application-policy name="DLG_REGW_POLICY">
>>>> <authentication>
>>>> <login-module
>>>> code="org.jboss.security.auth.spi.LdapLoginModule"
>>>> flag="required" >
>>>> <module-option
>>>> name="java.naming.provider.url">ldap://ldap-host:389/</module-
>>>> option>
>>>> <module-option
>>>> name="rolesCtxDN">OU=Groups,DC=WHEEL</module-option>
>>>> <module-option
>>>> name="matchOnUserDN">false</module-option>
>>>> <module-option
>>>> name="uidAttributeID">sAMAccountName</module-option>
>>>> <module-option
>>>> name="roleAttributeID">memberOf</module-option>
>>>> <module-option
>>>> name="roleAttributeIsDN">true</module-option>
>>>> <module-option
>>>> name="roleNameAttributeID">name</module-option>
>>>> <module-option
>>>> name="searchTimeLimit">5000</module-option>
>>>> <module-option
>>>> name="allowEmptyPasswords">false</module-option>
>>>> <module-option
>>>> name="searchScope">SUBTREE_SCOPE</module-option>
>>>> </login-module>
>>>> </authentication>
>>>> </application-policy>
>>>>
>>>> --
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>>>> Sent from the JSecurity User mailing list archive at Nabble.com.
>>>>
>>>>
>>>
>>>
>>>
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>>> Sent from the JSecurity User mailing list archive at Nabble.com.
>>>
>>
>>
>>
>>
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>>
>
>
>
>
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>
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