[ACCUMULO-4140] SecurityOperation checks for root usernames fail when using Kerberos

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.7.0
• Fix Version/s: 1.7.1, 1.8.0
• Component/s: core
• Assignee: William Slacum
• Reporter: William Slacum
• Created: 11/Feb/16 07:40
• Updated: 17/Feb/16 19:56
• Resolved: 17/Feb/16 19:56

Description

I'm currently extending the KerberosAuthenticator, since SecurityOperation depends on it for a few checks (see uses of SecurityOperation#isKerberos). I relied on KerberosAuthenticator#initializeSecurity to create the root user's ZooKeeper entry for me. When the KerberosAuthenticator creates principals, it base64 encodes them. This causes the root entry under /accumulo/instance/users to also be base64 encoded.

In a few spots, SecurityOperation will try to short circuit things by checking if the user has the root user name. This will fail because the principal will be in plain-form (ie, [e-mail]), and the data from ZooKeeper is base-64 encoded.

This opens up a security hole where the root user can have its permissions altered. I had a small test where I created a new user, gave it SystemPermission.GRANT, then revoked the root user's ability to create a table (this is explicitly disallowed in SecurityOperation#canRevokeSystem).

Test:

  "Accumulo" should "revoke app2's attempt to modify the root user" in {
    val root = UserGroupInformation.loginUserFromKeytabAndReturnUGI("[e-mail]", kdc.getRootUser.getKeytab.getAbsolutePath)
    val con = accumulo.getConnector(root.getUserName, new KerberosToken)
    con.securityOperations.grantSystemPermission(app1.getUserName, SystemPermission.GRANT)
    doAs(app1, () => {
      val con = accumulo.getConnector(app1.getUserName, new KerberosToken)
      con.securityOperations.revokeSystemPermission(root.getUserName, SystemPermission.CREATE_TABLE)
    })
    // this will now throw an error
    con.tableOperations.create("hopefully_I_can_create_ this")
  }

Output:

- should revoke app2's attempt to modify the root user *** FAILED ***
  org.apache.accumulo.core.client.AccumuloSecurityException: Error PERMISSION_DENIED for user [e-mail] on table hopefully_I_can_create_this(?) - User does not have permission to perform this action
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.doFateOperation(TableOperationsImpl.java:285)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.doFateOperation(TableOperationsImpl.java:261)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.doTableFateOperation(TableOperationsImpl.java:1427)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.create(TableOperationsImpl.java:188)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.create(TableOperationsImpl.java:155)
  at KerbSpec$$anonfun$8.apply$mcV$sp(ServerTest.scala:131)
  at KerbSpec$$anonfun$8.apply(ServerTest.scala:122)
  at KerbSpec$$anonfun$8.apply(ServerTest.scala:122)
  at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
  at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
  ...
  Cause: org.apache.accumulo.core.client.impl.thrift.ThriftSecurityException:
  at org.apache.accumulo.core.master.thrift.FateService$executeFateOperation_result$executeFateOperation_resultStandardScheme.read(FateService.java:3129)
  at org.apache.accumulo.core.master.thrift.FateService$executeFateOperation_result$executeFateOperation_resultStandardScheme.read(FateService.java:3115)
  at org.apache.accumulo.core.master.thrift.FateService$executeFateOperation_result.read(FateService.java:3057)
  at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
  at org.apache.accumulo.core.master.thrift.FateService$Client.recv_executeFateOperation(FateService.java:146)
  at org.apache.accumulo.core.master.thrift.FateService$Client.executeFateOperation(FateService.java:127)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.executeFateOperation(TableOperationsImpl.java:217)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.doFateOperation(TableOperationsImpl.java:270)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.doFateOperation(TableOperationsImpl.java:261)
  at org.apache.accumulo.core.client.impl.TableOperationsImpl.doTableFateOperation(TableOperationsImpl.java:1427)
  ...

I'm reasonably certain the that the fix is to just have the KerberosAuthenticator not base64 encode the root principal when initializeSecurity is called.