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https://issues.apache.org/jira/browse/HADOOP-8803?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13459825#comment-13459825
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Luke Lu commented on HADOOP-8803:
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bq. as long as the hacker can get root privilege, she or he always can get the
new key from the namenode and generate arbitrary Block Token to access other
datanodes, in the end, the whole HDFS is exposed to attacker.
Since block id generation is currently random (see also HDFS-898), there is no
practical way to generate correct block tokens to access "the whole" HDFS.
Monitoring system will immediately notice a spike of failed block requests if
brutal force is used and blacklist the node. You should be more concerned about
the delegation tokens stored locally on that node. Even more so, if the hacker
can root one DN/TT node, it can probably root the rest of the nodes given all
the nodes are uniformly configured in typical clusters.
bq. NameNode has to generate token for each replica and that indeed degrade the
performance...I can test how much of this overhead...
Make sure you test cases, where number of replicas is way over 3. 10 is common
for distributed cache files. 100 is not uncommon on large clusters.
I've been fortunate to have on and off in depth discussions with Kan (Zhang,
the original Hadoop security architect) about an alternative block token design
with unique DN key for over a year now. IMO, the original hadoop security team
made the right trade off on "perceived" security vs performance.
I'm not saying that the current Hadoop security design/implementation is
perfect. But I think more elaborate authorization scheme a la. POSIX.1e ACLs is
probably more useful than futzing with block tokens.
> Make Hadoop running more secure public cloud envrionment
> --------------------------------------------------------
>
> Key: HADOOP-8803
> URL: https://issues.apache.org/jira/browse/HADOOP-8803
> Project: Hadoop Common
> Issue Type: New Feature
> Components: fs, ipc, security
> Affects Versions: 0.20.204.0
> Reporter: Xianqing Yu
> Labels: hadoop
> Original Estimate: 2m
> Remaining Estimate: 2m
>
> I am a Ph.D student in North Carolina State University. I am modifying the
> Hadoop's code (which including most parts of Hadoop, e.g. JobTracker,
> TaskTracker, NameNode, DataNode) to achieve better security.
>
> My major goal is that make Hadoop running more secure in the Cloud
> environment, especially for public Cloud environment. In order to achieve
> that, I redesign the currently security mechanism and achieve following
> proprieties:
> 1. Bring byte-level access control to Hadoop HDFS. Based on 0.20.204, HDFS
> access control is based on user or block granularity, e.g. HDFS Delegation
> Token only check if the file can be accessed by certain user or not, Block
> Token only proof which block or blocks can be accessed. I make Hadoop can do
> byte-granularity access control, each access party, user or task process can
> only access the bytes she or he least needed.
> 2. I assume that in the public Cloud environment, only Namenode, secondary
> Namenode, JobTracker can be trusted. A large number of Datanode and
> TaskTracker may be compromised due to some of them may be running under less
> secure environment. So I re-design the secure mechanism to make the damage
> the hacker can do to be minimized.
>
> a. Re-design the Block Access Token to solve wildly shared-key problem of
> HDFS. In original Block Access Token design, all HDFS (Namenode and Datanode)
> share one master key to generate Block Access Token, if one DataNode is
> compromised by hacker, the hacker can get the key and generate any Block
> Access Token he or she want.
>
> b. Re-design the HDFS Delegation Token to do fine-grain access control for
> TaskTracker and Map-Reduce Task process on HDFS.
>
> In the Hadoop 0.20.204, all TaskTrackers can use their kerberos credentials
> to access any files for MapReduce on HDFS. So they have the same privilege as
> JobTracker to do read or write tokens, copy job file, etc.. However, if one
> of them is compromised, every critical thing in MapReduce directory (job
> file, Delegation Token) is exposed to attacker. I solve the problem by making
> JobTracker to decide which TaskTracker can access which file in MapReduce
> Directory on HDFS.
>
> For Task process, once it get HDFS Delegation Token, it can access everything
> belong to this job or user on HDFS. By my design, it can only access the
> bytes it needed from HDFS.
>
> There are some other improvement in the security, such as TaskTracker can not
> know some information like blockID from the Block Token (because it is
> encrypted by my way), and HDFS can set up secure channel to send data as a
> option.
>
> By those features, Hadoop can run much securely under uncertain environment
> such as Public Cloud. I already start to test my prototype. I want to know
> that whether community is interesting about my work? Is that a value work to
> contribute to production Hadoop?
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