HADOOP-11332. KerberosAuthenticator#doSpnegoSequence should check if kerberos TGT is available in the subject. Contributed by Dian Fu.

hadoop-common-project/hadoop-auth/src/main/java/org/apache/hadoop/security/authentication/client/KerberosAuthenticator.java

@@ -23,6 +23,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.security.auth.Subject;
+import javax.security.auth.kerberos.KerberosKey;
+import javax.security.auth.kerberos.KerberosTicket;
 import javax.security.auth.login.AppConfigurationEntry;
 import javax.security.auth.login.Configuration;
 import javax.security.auth.login.LoginContext;
@@ -247,7 +249,9 @@ public class KerberosAuthenticator implements Authenticator {
     try {
       AccessControlContext context = AccessController.getContext();
       Subject subject = Subject.getSubject(context);
-      if (subject == null) {
+      if (subject == null
+          || (subject.getPrivateCredentials(KerberosKey.class).isEmpty()
+              && subject.getPrivateCredentials(KerberosTicket.class).isEmpty())) {
         LOG.debug("No subject in context, logging in");
         subject = new Subject();
         LoginContext login = new LoginContext("", subject,

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -496,6 +496,9 @@ Release 2.7.0 - UNRELEASED
     HADOOP-11342. KMS key ACL should ignore ALL operation for default key ACL
     and whitelist key ACL. (Dian Fu via wang)
 
+    HADOOP-11332. KerberosAuthenticator#doSpnegoSequence should check if
+    kerberos TGT is available in the subject. (Dian Fu via atm)
+
 Release 2.6.0 - 2014-11-18
 
   INCOMPATIBLE CHANGES