diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index 4ffa26b7a84..dcc8f5bde61 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -565,6 +565,9 @@ Release 2.3.0 - UNRELEASED
     HADOOP-10087. UserGroupInformation.getGroupNames() fails to return primary
     group first when JniBasedUnixGroupsMappingWithFallback is used (cmccabe)
 
+    HADOOP-10175. Har files system authority should preserve userinfo.
+    (Chuan Liu via cnauroth)
+
 Release 2.2.0 - 2013-10-13
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/HarFileSystem.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/HarFileSystem.java
index 091b35a846a..88208da651a 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/HarFileSystem.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/HarFileSystem.java
@@ -294,6 +294,10 @@ public class HarFileSystem extends FileSystem {
   private String getHarAuth(URI underLyingUri) {
     String auth = underLyingUri.getScheme() + "-";
     if (underLyingUri.getHost() != null) {
+      if (underLyingUri.getUserInfo() != null) {
+        auth += underLyingUri.getUserInfo();
+        auth += "@";
+      }
       auth += underLyingUri.getHost();
       if (underLyingUri.getPort() != -1) {
         auth += ":";
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestHarFileSystemBasics.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestHarFileSystemBasics.java
index 237d7161f72..577abfd090e 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestHarFileSystemBasics.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestHarFileSystemBasics.java
@@ -258,6 +258,22 @@ public class TestHarFileSystemBasics {
                  0, expectedFileNames.size());
   }
 
+  @Test
+  public void testMakeQualifiedPath() throws Exception {
+    // Construct a valid har file system path with authority that
+    // contains userinfo and port. The userinfo and port are useless
+    // in local fs uri. They are only used to verify har file system
+    // can correctly preserve the information for the underlying file system.
+    String harPathWithUserinfo = "har://file-user:passwd@localhost:80"
+        + harPath.toUri().getPath().toString();
+    Path path = new Path(harPathWithUserinfo);
+    Path qualifiedPath = path.getFileSystem(conf).makeQualified(path);
+    assertTrue(String.format(
+        "The qualified path (%s) did not match the expected path (%s).",
+        qualifiedPath.toString(), harPathWithUserinfo),
+        qualifiedPath.toString().equals(harPathWithUserinfo));
+  }
+
   // ========== Negative:
 
   @Test