From a16623df2148e59e1b7dcf98939b03cb7440d143 Mon Sep 17 00:00:00 2001
From: Xiao Chen <xiao@apache.org>
Date: Tue, 12 Jun 2018 11:14:33 -0700
Subject: [PATCH] HADOOP-15307. NFS: flavor AUTH_SYS should use VerifierNone.
 Contributed by Gabor Bota.

---
 .../org/apache/hadoop/oncrpc/security/Verifier.java  | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/security/Verifier.java b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/security/Verifier.java
index f3202a1d33c..3c0e5fe36e2 100644
--- a/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/security/Verifier.java
+++ b/hadoop-common-project/hadoop-nfs/src/main/java/org/apache/hadoop/oncrpc/security/Verifier.java
@@ -41,12 +41,18 @@ public abstract class Verifier extends RpcAuthInfo {
   public static Verifier readFlavorAndVerifier(XDR xdr) {
     AuthFlavor flavor = AuthFlavor.fromValue(xdr.readInt());
     final Verifier verifer;
-    if(flavor == AuthFlavor.AUTH_NONE) {
+    if (flavor == AuthFlavor.AUTH_NONE) {
       verifer = new VerifierNone();
-    } else if(flavor == AuthFlavor.RPCSEC_GSS) {
+    } else if (flavor == AuthFlavor.AUTH_SYS) {
+      // Added in HADOOP-15307 based on HDFS-5085:
+      // When the auth flavor is AUTH_SYS, the corresponding verifier is
+      // AUTH_NONE. I.e., it is impossible to have a verifier with auth
+      // flavor AUTH_SYS.
+      verifer = new VerifierNone();
+    } else if (flavor == AuthFlavor.RPCSEC_GSS) {
       verifer = new VerifierGSS();
     } else {
-      throw new UnsupportedOperationException("Unsupported verifier flavor"
+      throw new UnsupportedOperationException("Unsupported verifier flavor: "
           + flavor);
     }
     verifer.read(xdr);