Robert Levas created AMBARI-18938:
-------------------------------------
Summary: NPE when authenticating via a Centrify LDAP proxy
Key: AMBARI-18938
URL: https://issues.apache.org/jira/browse/AMBARI-18938
Project: Ambari
Issue Type: Bug
Components: ambari-server
Affects Versions: 2.4.0
Reporter: Robert Levas
Assignee: Robert Levas
Fix For: 2.5.0
When authenticating using LDAP where the LDAP server is a Centrify LDAP proxy,
a {{NullPointerException}} is being thrown due to unexpected missing LDAP user
object attributes.
{noformat}
10 Nov 2016 08:23:38,789 ERROR [ambari-client-thread-25]
AmbariLdapBindAuthenticator:95 - Caught exception
java.lang.NullPointerException
at
org.apache.ambari.server.security.authorization.AmbariLdapBindAuthenticator.authenticate(AmbariLdapBindAuthenticator.java:83)
at
org.springframework.security.ldap.authentication.LdapAuthenticationProvider.doAuthentication(LdapAuthenticationProvider.java:178)
at
org.springframework.security.ldap.authentication.AbstractLdapAuthenticationProvider.authenticate(AbstractLdapAuthenticationProvider.java:61)
at
org.apache.ambari.server.security.authorization.AmbariLdapAuthenticationProvider.authenticate(AmbariLdapAuthenticationProvider.java:73)
at
org.springframework.security.authentication.ProviderManager.authenticate(ProviderManager.java:156)
at
org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:168)
at
org.apache.ambari.server.security.authentication.AmbariAuthenticationFilter.doFilter(AmbariAuthenticationFilter.java:88)
at
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at
org.apache.ambari.server.security.authorization.AmbariUserAuthorizationFilter.doFilter(AmbariUserAuthorizationFilter.java:91)
at
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at
org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
at
org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at
org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
at
org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
at
org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:237)
at
org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:167)
at
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1478)
at
org.apache.ambari.server.api.MethodOverrideFilter.doFilter(MethodOverrideFilter.java:72)
at
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1478)
at
org.apache.ambari.server.api.AmbariPersistFilter.doFilter(AmbariPersistFilter.java:47)
at
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1478)
at
org.apache.ambari.server.security.AbstractSecurityHeaderFilter.doFilter(AbstractSecurityHeaderFilter.java:109)
at
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1478)
at
org.eclipse.jetty.servlets.UserAgentFilter.doFilter(UserAgentFilter.java:82)
at org.eclipse.jetty.servlets.GzipFilter.doFilter(GzipFilter.java:294)
at
org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1478)
at
org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:499)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:137)
at
org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:557)
at
org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:231)
at
org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1086)
at
org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:427)
at
org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:193)
at
org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1020)
at
org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:135)
at
org.apache.ambari.server.controller.AmbariHandlerList.processHandlers(AmbariHandlerList.java:212)
at
org.apache.ambari.server.controller.AmbariHandlerList.processHandlers(AmbariHandlerList.java:201)
at
org.apache.ambari.server.controller.AmbariHandlerList.handle(AmbariHandlerList.java:139)
at
org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
at org.eclipse.jetty.server.Server.handle(Server.java:370)
at
org.eclipse.jetty.server.AbstractHttpConnection.handleRequest(AbstractHttpConnection.java:494)
at
org.eclipse.jetty.server.AbstractHttpConnection.headerComplete(AbstractHttpConnection.java:973)
at
org.eclipse.jetty.server.AbstractHttpConnection$RequestHandler.headerComplete(AbstractHttpConnection.java:1035)
at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:641)
at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:231)
at
org.eclipse.jetty.server.AsyncHttpConnection.handle(AsyncHttpConnection.java:82)
at
org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:696)
at
org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:53)
at
org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:608)
at
org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:543)
at java.lang.Thread.run(Thread.java:745)
{noformat}
*Cause*
The cause for this {{NPE}} is related to missing data from the attribute search
request made to a Centrify LDAP proxy after a bind has occurred. Since the
query filter at this point is "{(objectClass=*}}", the Centrify LDAP proxy does
not have enough data to determine what information to return to the caller.
However, the filter was something like "{(objectClass=posixAccount}}", it will
be able to build a set of attributes to return to the caller since it would
determine that the call wants data for a specific _profile_.
This can be seen by the following {{tcpdump}} entry:
{code}
LDAPMessage searchRequest(2) "uid=user1,ou=people,ou=dev,dc=apache,dc=org"
baseObject
messageID: 2
protocolOp: searchRequest (3)
searchRequest
baseObject: uid=user1,ou=people,ou=dev,dc=apache,dc=org
scope: baseObject (0)
derefAliases: derefAlways (3)
sizeLimit: 0
timeLimit: 0
typesOnly: False
Filter: (objectClass=*)
attributes: 0 items
[Response In: 2]
controls: 1 item
{code}
Note the filter line above: *{{Filter: (objectClass=*)}}*
>From the Centrify LDAP proxy logs, the following lines can be seen showing
>that no mapping is avaialbe:
{noformat}
Nov 8 12:13:45 host1 slapd: cdc search start with filterstr: (objectClass=*)
Nov 8 12:13:45 host1 slapd: cdc search: objectType = ( is mapped to NONE)
Nov 8 12:13:45 host1 slapd: cdc search after translation filter =
(objectClass=*)
{noformat}
This search filter is hardcoded in {{com.sun.jndi.ldap.LdapCtx}} as seen in
http://grepcode.com/file/repository.grepcode.com/java/root/jdk/openjdk/6-b14/com/sun/jndi/ldap/LdapCtx.java#1308.
This code is invoked from the Spring LDAP library after attempting to
authenticate using the Spring
org.springframework.security.ldap.authentication.BindAuthenticator class.
*Solution*
To solve this, Ambari should avoid using
{{org.springframework.security.ldap.authentication.BindAuthenticator}} to
authenticate users via LDAP so that more control can be had over when and how
user attributes are obtained.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
