HADOOP-16916: ABFS: Delegation SAS generator for integration with Ranger

Contributed by Thomas Marquardt.

DETAILS:

Previously we had a SASGenerator class which generated Service SAS, but we need to add DelegationSASGenerator.
I separated SASGenerator into a base class and two subclasses ServiceSASGenerator and DelegationSASGenreator.  The
code in ServiceSASGenerator is copied from SASGenerator but the DelegationSASGenrator code is new.  The
DelegationSASGenerator code demonstrates how to use Delegation SAS with minimal permissions, as would be used
by an authorization service such as Apache Ranger.  Adding this to the tests helps us lock in this behavior.

Added a MockDelegationSASTokenProvider for testing User Delegation SAS.

Fixed the ITestAzureBlobFileSystemCheckAccess tests to assume oauth client ID so that they are ignored when that
is not configured.

To improve performance, AbfsInputStream/AbfsOutputStream re-use SAS tokens until the expiry is within 120 seconds.
After this a new SAS will be requested.  The default period of 120 seconds can be changed using the configuration
setting "fs.azure.sas.token.renew.period.for.streams".

The SASTokenProvider operation names were updated to correspond better with the ADLS Gen2 REST API, since these
operations must be provided tokens with appropriate SAS parameters to succeed.

Support for the version 2.0 AAD authentication endpoint was added to AzureADAuthenticator.

The getFileStatus method was mistakenly calling the ADLS Gen2 Get Properties API which requires read permission
while the getFileStatus call only requires execute permission.  ADLS Gen2 Get Status API is supposed to be used
for this purpose, so the underlying AbfsClient.getPathStatus API was updated with a includeProperties
parameter which is set to false for getFileStatus and true for getXAttr.

Added SASTokenProvider support for delete recursive.

Fixed bugs in AzureBlobFileSystem where public methods were not validating the Path by calling makeQualified.  This is
necessary to avoid passing null paths and to convert relative paths into absolute paths.

Canonicalized the path used for root path internally so that root path can be used with SAS tokens, which requires
that the path in the URL and the path in the SAS token match.  Internally the code was using
"//" instead of "/" for the root path, sometimes.  Also related to this, the AzureBlobFileSystemStore.getRelativePath
API was updated so that we no longer remove and then add back a preceding forward / to paths.

To run ITestAzureBlobFileSystemDelegationSAS tests follow the instructions in testing_azure.md under the heading
"To run Delegation SAS test cases".  You also need to set "fs.azure.enable.check.access" to true.

TEST RESULTS:

namespace.enabled=true
auth.type=SharedKey
-------------------
$mvn -T 1C -Dparallel-tests=abfs -Dscale -DtestsThreadCount=8 clean verify
Tests run: 63, Failures: 0, Errors: 0, Skipped: 0
Tests run: 432, Failures: 0, Errors: 0, Skipped: 41
Tests run: 206, Failures: 0, Errors: 0, Skipped: 24

namespace.enabled=false
auth.type=SharedKey
-------------------
$mvn -T 1C -Dparallel-tests=abfs -Dscale -DtestsThreadCount=8 clean verify
Tests run: 63, Failures: 0, Errors: 0, Skipped: 0
Tests run: 432, Failures: 0, Errors: 0, Skipped: 244
Tests run: 206, Failures: 0, Errors: 0, Skipped: 24

namespace.enabled=true
auth.type=SharedKey
sas.token.provider.type=MockDelegationSASTokenProvider
enable.check.access=true
-------------------
$mvn -T 1C -Dparallel-tests=abfs -Dscale -DtestsThreadCount=8 clean verify
Tests run: 63, Failures: 0, Errors: 0, Skipped: 0
Tests run: 432, Failures: 0, Errors: 0, Skipped: 33
Tests run: 206, Failures: 0, Errors: 0, Skipped: 24

namespace.enabled=true
auth.type=OAuth
-------------------
$mvn -T 1C -Dparallel-tests=abfs -Dscale -DtestsThreadCount=8 clean verify
Tests run: 63, Failures: 0, Errors: 0, Skipped: 0
Tests run: 432, Failures: 0, Errors: 1, Skipped: 74
Tests run: 206, Failures: 0, Errors: 0, Skipped: 140

hadoop-tools/hadoop-azure/dev-support/findbugs-exclude.xml

@@ -15,6 +15,23 @@
    limitations under the License.
 -->
 <FindBugsFilter>
+     <!-- This reference equality check is an intentional light weight
+          check to avoid re-validating the token when re-used. -->
+     <Match>
+       <Class name="org.apache.hadoop.fs.azurebfs.utils.CachedSASToken" />
+       <Method name="update" />
+       <Bug pattern="ES_COMPARING_PARAMETER_STRING_WITH_EQ" />
+     </Match>
+
+     <!-- This is intentional. The unsynchronized field access is safe
+          and only synchronized access is used when using the sasToken
+          for authorization. -->
+     <Match>
+       <Class name="org.apache.hadoop.fs.azurebfs.utils.CachedSASToken" />
+       <Field name="sasToken" />
+       <Bug pattern="IS2_INCONSISTENT_SYNC" />
+     </Match>
+
      <!-- It is okay to skip up to end of file. No need to check return value. -->
      <Match>
        <Class name="org.apache.hadoop.fs.azure.AzureNativeFileSystemStore" />
@@ -24,7 +41,7 @@
      </Match>
 
      <!-- Returning fully loaded array to iterate through is a convenience
-	  and helps performance. -->
+          and helps performance. -->
      <Match>
        <Class name="org.apache.hadoop.fs.azure.NativeAzureFileSystem$FolderRenamePending" />
        <Method name="getFiles" />
@@ -40,7 +57,7 @@
      </Match>
      
      <!-- Using a key set iterator is fine because this is not a performance-critical
-	  method. -->
+          method. -->
      <Match>
        <Class name="org.apache.hadoop.fs.azure.PageBlobOutputStream" />
        <Method name="logAllStackTraces" />

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/AbfsConfiguration.java

@@ -210,6 +210,11 @@ public class AbfsConfiguration{
           DefaultValue = DEFAULT_ABFS_LATENCY_TRACK)
   private boolean trackLatency;
 
+  @LongConfigurationValidatorAnnotation(ConfigurationKey = FS_AZURE_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS,
+      MinValue = 0,
+      DefaultValue = DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS)
+  private long sasTokenRenewPeriodForStreamsInSeconds;
+
   private Map<String, String> storageAccountKeys;
 
   public AbfsConfiguration(final Configuration rawConfig, String accountName)
@@ -451,6 +456,10 @@ public boolean isCheckAccessEnabled() {
     return this.isCheckAccessEnabled;
   }
 
+  public long getSasTokenRenewPeriodForStreamsInSeconds() {
+    return this.sasTokenRenewPeriodForStreamsInSeconds;
+  }
+
   public String getAzureBlockLocationHost() {
     return this.azureBlockLocationHost;
   }

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/AzureBlobFileSystem.java

@@ -679,15 +679,17 @@ public void setXAttr(final Path path, final String name, final byte[] value, fin
       throw new IllegalArgumentException("A valid name and value must be specified.");
     }
 
+    Path qualifiedPath = makeQualified(path);
+
     try {
-      Hashtable<String, String> properties = abfsStore.getPathStatus(path);
+      Hashtable<String, String> properties = abfsStore.getPathStatus(qualifiedPath);
       String xAttrName = ensureValidAttributeName(name);
       boolean xAttrExists = properties.containsKey(xAttrName);
       XAttrSetFlag.validate(name, xAttrExists, flag);
 
       String xAttrValue = abfsStore.decodeAttribute(value);
       properties.put(xAttrName, xAttrValue);
-      abfsStore.setPathProperties(path, properties);
+      abfsStore.setPathProperties(qualifiedPath, properties);
     } catch (AzureBlobFileSystemException ex) {
       checkException(path, ex);
     }
@@ -712,9 +714,11 @@ public byte[] getXAttr(final Path path, final String name)
       throw new IllegalArgumentException("A valid name must be specified.");
     }
 
+    Path qualifiedPath = makeQualified(path);
+
     byte[] value = null;
     try {
-      Hashtable<String, String> properties = abfsStore.getPathStatus(path);
+      Hashtable<String, String> properties = abfsStore.getPathStatus(qualifiedPath);
       String xAttrName = ensureValidAttributeName(name);
       if (properties.containsKey(xAttrName)) {
         String xAttrValue = properties.get(xAttrName);

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/AzureBlobFileSystemStore.java

@@ -247,8 +247,7 @@ public boolean getIsNamespaceEnabled() throws AzureBlobFileSystemException {
     LOG.debug("Get root ACL status");
     try (AbfsPerfInfo perfInfo = startTracking("getIsNamespaceEnabled",
         "getAclStatus")) {
-      AbfsRestOperation op = client.getAclStatus(
+      AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.ROOT_PATH);
-          AbfsHttpConstants.FORWARD_SLASH + AbfsHttpConstants.ROOT_PATH);
       perfInfo.registerResult(op.getResult());
       isNamespaceEnabled = Trilean.getTrilean(true);
       perfInfo.registerSuccess(true);
@@ -353,7 +352,7 @@ public Hashtable<String, String> getPathStatus(final Path path) throws AzureBlob
               path);
 
       final Hashtable<String, String> parsedXmsProperties;
-      final AbfsRestOperation op = client.getPathStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path));
+      final AbfsRestOperation op = client.getPathStatus(getRelativePath(path), true);
       perfInfo.registerResult(op.getResult());
 
       final String xMsProperties = op.getResult().getResponseHeader(HttpHeaderConfigurations.X_MS_PROPERTIES);
@@ -379,7 +378,7 @@ public void setPathProperties(final Path path, final Hashtable<String, String> p
       } catch (CharacterCodingException ex) {
         throw new InvalidAbfsRestOperationException(ex);
       }
-      final AbfsRestOperation op = client.setPathProperties(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path), commaSeparatedProperties);
+      final AbfsRestOperation op = client.setPathProperties(getRelativePath(path), commaSeparatedProperties);
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
     }
   }
@@ -418,7 +417,9 @@ public OutputStream createFile(final Path path,
               umask.toString(),
               isNamespaceEnabled);
 
-      final AbfsRestOperation op = client.createPath(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path), true, overwrite,
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.createPath(relativePath, true, overwrite,
               isNamespaceEnabled ? getOctalNotation(permission) : null,
               isNamespaceEnabled ? getOctalNotation(umask) : null);
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
@@ -426,14 +427,14 @@ public OutputStream createFile(final Path path,
       return new AbfsOutputStream(
           client,
           statistics,
-          AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path),
+          relativePath,
           0,
           populateAbfsOutputStreamContext());
     }
   }
 
   private AbfsOutputStreamContext populateAbfsOutputStreamContext() {
-    return new AbfsOutputStreamContext()
+    return new AbfsOutputStreamContext(abfsConfiguration.getSasTokenRenewPeriodForStreamsInSeconds())
             .withWriteBufferSize(abfsConfiguration.getWriteBufferSize())
             .enableFlush(abfsConfiguration.isFlushEnabled())
             .disableOutputStreamFlush(abfsConfiguration.isOutputStreamFlushDisabled())
@@ -452,7 +453,7 @@ public void createDirectory(final Path path, final FsPermission permission, fina
               umask,
               isNamespaceEnabled);
 
-      final AbfsRestOperation op = client.createPath(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path), false, true,
+      final AbfsRestOperation op = client.createPath(getRelativePath(path), false, true,
               isNamespaceEnabled ? getOctalNotation(permission) : null,
               isNamespaceEnabled ? getOctalNotation(umask) : null);
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
@@ -466,7 +467,9 @@ public AbfsInputStream openFileForRead(final Path path, final FileSystem.Statist
               client.getFileSystem(),
               path);
 
-      final AbfsRestOperation op = client.getPathStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path));
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getPathStatus(relativePath, false);
       perfInfo.registerResult(op.getResult());
 
       final String resourceType = op.getResult().getResponseHeader(HttpHeaderConfigurations.X_MS_RESOURCE_TYPE);
@@ -485,14 +488,14 @@ public AbfsInputStream openFileForRead(final Path path, final FileSystem.Statist
 
       // Add statistics for InputStream
       return new AbfsInputStream(client, statistics,
-              AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path), contentLength,
+              relativePath, contentLength,
               populateAbfsInputStreamContext(),
               eTag);
     }
   }
 
   private AbfsInputStreamContext populateAbfsInputStreamContext() {
-    return new AbfsInputStreamContext()
+    return new AbfsInputStreamContext(abfsConfiguration.getSasTokenRenewPeriodForStreamsInSeconds())
             .withReadBufferSize(abfsConfiguration.getReadBufferSize())
             .withReadAheadQueueDepth(abfsConfiguration.getReadAheadQueueDepth())
             .withTolerateOobAppends(abfsConfiguration.getTolerateOobAppends())
@@ -507,7 +510,9 @@ public OutputStream openFileForWrite(final Path path, final FileSystem.Statistic
               path,
               overwrite);
 
-      final AbfsRestOperation op = client.getPathStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path));
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getPathStatus(relativePath, false);
       perfInfo.registerResult(op.getResult());
 
       final String resourceType = op.getResult().getResponseHeader(HttpHeaderConfigurations.X_MS_RESOURCE_TYPE);
@@ -528,7 +533,7 @@ public OutputStream openFileForWrite(final Path path, final FileSystem.Statistic
       return new AbfsOutputStream(
           client,
           statistics,
-          AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path),
+          relativePath,
           offset,
           populateAbfsOutputStreamContext());
     }
@@ -552,10 +557,13 @@ public void rename(final Path source, final Path destination) throws
 
     String continuation = null;
 
+    String sourceRelativePath = getRelativePath(source);
+    String destinationRelativePath = getRelativePath(destination);
+
     do {
       try (AbfsPerfInfo perfInfo = startTracking("rename", "renamePath")) {
-        AbfsRestOperation op = client.renamePath(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(source),
+        AbfsRestOperation op = client.renamePath(sourceRelativePath,
-                AbfsHttpConstants.FORWARD_SLASH + getRelativePath(destination), continuation);
+                destinationRelativePath, continuation);
         perfInfo.registerResult(op.getResult());
         continuation = op.getResult().getResponseHeader(HttpHeaderConfigurations.X_MS_CONTINUATION);
         perfInfo.registerSuccess(true);
@@ -582,10 +590,12 @@ public void delete(final Path path, final boolean recursive)
 
     String continuation = null;
 
+    String relativePath = getRelativePath(path);
+
     do {
       try (AbfsPerfInfo perfInfo = startTracking("delete", "deletePath")) {
         AbfsRestOperation op = client.deletePath(
-                AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path), recursive, continuation);
+                relativePath, recursive, continuation);
         perfInfo.registerResult(op.getResult());
         continuation = op.getResult().getResponseHeader(HttpHeaderConfigurations.X_MS_CONTINUATION);
         perfInfo.registerSuccess(true);
@@ -611,14 +621,14 @@ public FileStatus getFileStatus(final Path path) throws IOException {
       if (path.isRoot()) {
         if (isNamespaceEnabled) {
           perfInfo.registerCallee("getAclStatus");
-          op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + AbfsHttpConstants.ROOT_PATH);
+          op = client.getAclStatus(getRelativePath(path));
         } else {
           perfInfo.registerCallee("getFilesystemProperties");
           op = client.getFilesystemProperties();
         }
       } else {
         perfInfo.registerCallee("getPathStatus");
-        op = client.getPathStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path));
+        op = client.getPathStatus(getRelativePath(path), false);
       }
 
       perfInfo.registerResult(op.getResult());
@@ -698,14 +708,14 @@ public FileStatus[] listStatus(final Path path, final String startFrom) throws I
             path,
             startFrom);
 
-    final String relativePath = path.isRoot() ? AbfsHttpConstants.EMPTY_STRING : getRelativePath(path);
+    final String relativePath = getRelativePath(path);
     String continuation = null;
 
     // generate continuation token if a valid startFrom is provided.
     if (startFrom != null && !startFrom.isEmpty()) {
       continuation = getIsNamespaceEnabled()
               ? generateContinuationTokenForXns(startFrom)
-              : generateContinuationTokenForNonXns(path.isRoot() ? ROOT_PATH : relativePath, startFrom);
+              : generateContinuationTokenForNonXns(relativePath, startFrom);
     }
 
     ArrayList<FileStatus> fileStatuses = new ArrayList<>();
@@ -793,12 +803,13 @@ private String generateContinuationTokenForXns(final String firstEntryName) {
   }
 
   // generate continuation token for non-xns account
-  private String generateContinuationTokenForNonXns(final String path, final String firstEntryName) {
+  private String generateContinuationTokenForNonXns(String path, final String firstEntryName) {
     Preconditions.checkArgument(!Strings.isNullOrEmpty(firstEntryName)
             && !firstEntryName.startsWith(AbfsHttpConstants.ROOT_PATH),
             "startFrom must be a dir/file name and it can not be a full path");
 
     // Notice: non-xns continuation token requires full path (first "/" is not included) for startFrom
+    path = AbfsClient.getDirectoryQueryParameter(path);
     final String startFrom = (path.isEmpty() || path.equals(ROOT_PATH))
             ? firstEntryName
             : path + ROOT_PATH + firstEntryName;
@@ -846,8 +857,7 @@ public void setOwner(final Path path, final String owner, final String group) th
       final String transformedOwner = identityTransformer.transformUserOrGroupForSetRequest(owner);
       final String transformedGroup = identityTransformer.transformUserOrGroupForSetRequest(group);
 
-      final AbfsRestOperation op = client.setOwner(
+      final AbfsRestOperation op = client.setOwner(getRelativePath(path),
-              AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
               transformedOwner,
               transformedGroup);
 
@@ -870,8 +880,7 @@ public void setPermission(final Path path, final FsPermission permission) throws
               path.toString(),
               permission.toString());
 
-      final AbfsRestOperation op = client.setPermission(
+      final AbfsRestOperation op = client.setPermission(getRelativePath(path),
-              AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
               String.format(AbfsHttpConstants.PERMISSION_FORMAT, permission.toOctal()));
 
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
@@ -897,7 +906,9 @@ public void modifyAclEntries(final Path path, final List<AclEntry> aclSpec) thro
       final Map<String, String> modifyAclEntries = AbfsAclHelper.deserializeAclSpec(AclEntry.aclSpecToString(aclSpec));
       boolean useUpn = AbfsAclHelper.isUpnFormatAclEntries(modifyAclEntries);
 
-      final AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true), useUpn);
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getAclStatus(relativePath, useUpn);
       perfInfoGet.registerResult(op.getResult());
       final String eTag = op.getResult().getResponseHeader(HttpHeaderConfigurations.ETAG);
 
@@ -909,7 +920,7 @@ public void modifyAclEntries(final Path path, final List<AclEntry> aclSpec) thro
 
       try (AbfsPerfInfo perfInfoSet = startTracking("modifyAclEntries", "setAcl")) {
         final AbfsRestOperation setAclOp
-                = client.setAcl(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
+                = client.setAcl(relativePath,
                 AbfsAclHelper.serializeAclSpec(aclEntries), eTag);
         perfInfoSet.registerResult(setAclOp.getResult())
                 .registerSuccess(true)
@@ -936,7 +947,9 @@ public void removeAclEntries(final Path path, final List<AclEntry> aclSpec) thro
       final Map<String, String> removeAclEntries = AbfsAclHelper.deserializeAclSpec(AclEntry.aclSpecToString(aclSpec));
       boolean isUpnFormat = AbfsAclHelper.isUpnFormatAclEntries(removeAclEntries);
 
-      final AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true), isUpnFormat);
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getAclStatus(relativePath, isUpnFormat);
       perfInfoGet.registerResult(op.getResult());
       final String eTag = op.getResult().getResponseHeader(HttpHeaderConfigurations.ETAG);
 
@@ -948,7 +961,7 @@ public void removeAclEntries(final Path path, final List<AclEntry> aclSpec) thro
 
       try (AbfsPerfInfo perfInfoSet = startTracking("removeAclEntries", "setAcl")) {
         final AbfsRestOperation setAclOp =
-                client.setAcl(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
+                client.setAcl(relativePath,
                 AbfsAclHelper.serializeAclSpec(aclEntries), eTag);
         perfInfoSet.registerResult(setAclOp.getResult())
                 .registerSuccess(true)
@@ -970,7 +983,9 @@ public void removeDefaultAcl(final Path path) throws AzureBlobFileSystemExceptio
               client.getFileSystem(),
               path.toString());
 
-      final AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true));
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getAclStatus(relativePath);
       perfInfoGet.registerResult(op.getResult());
       final String eTag = op.getResult().getResponseHeader(HttpHeaderConfigurations.ETAG);
       final Map<String, String> aclEntries = AbfsAclHelper.deserializeAclSpec(op.getResult().getResponseHeader(HttpHeaderConfigurations.X_MS_ACL));
@@ -988,7 +1003,7 @@ public void removeDefaultAcl(final Path path) throws AzureBlobFileSystemExceptio
 
       try (AbfsPerfInfo perfInfoSet = startTracking("removeDefaultAcl", "setAcl")) {
         final AbfsRestOperation setAclOp =
-                client.setAcl(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
+                client.setAcl(relativePath,
                 AbfsAclHelper.serializeAclSpec(aclEntries), eTag);
         perfInfoSet.registerResult(setAclOp.getResult())
                 .registerSuccess(true)
@@ -1010,7 +1025,9 @@ public void removeAcl(final Path path) throws AzureBlobFileSystemException {
               client.getFileSystem(),
               path.toString());
 
-      final AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true));
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getAclStatus(relativePath);
       perfInfoGet.registerResult(op.getResult());
       final String eTag = op.getResult().getResponseHeader(HttpHeaderConfigurations.ETAG);
 
@@ -1025,7 +1042,7 @@ public void removeAcl(final Path path) throws AzureBlobFileSystemException {
 
       try (AbfsPerfInfo perfInfoSet = startTracking("removeAcl", "setAcl")) {
         final AbfsRestOperation setAclOp =
-                client.setAcl(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
+                client.setAcl(relativePath,
                 AbfsAclHelper.serializeAclSpec(newAclEntries), eTag);
         perfInfoSet.registerResult(setAclOp.getResult())
                 .registerSuccess(true)
@@ -1052,7 +1069,9 @@ public void setAcl(final Path path, final List<AclEntry> aclSpec) throws AzureBl
       final Map<String, String> aclEntries = AbfsAclHelper.deserializeAclSpec(AclEntry.aclSpecToString(aclSpec));
       final boolean isUpnFormat = AbfsAclHelper.isUpnFormatAclEntries(aclEntries);
 
-      final AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true), isUpnFormat);
+      String relativePath = getRelativePath(path);
+
+      final AbfsRestOperation op = client.getAclStatus(relativePath, isUpnFormat);
       perfInfoGet.registerResult(op.getResult());
       final String eTag = op.getResult().getResponseHeader(HttpHeaderConfigurations.ETAG);
 
@@ -1064,7 +1083,7 @@ public void setAcl(final Path path, final List<AclEntry> aclSpec) throws AzureBl
 
       try (AbfsPerfInfo perfInfoSet = startTracking("setAcl", "setAcl")) {
         final AbfsRestOperation setAclOp =
-                client.setAcl(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true),
+                client.setAcl(relativePath,
                 AbfsAclHelper.serializeAclSpec(aclEntries), eTag);
         perfInfoSet.registerResult(setAclOp.getResult())
                 .registerSuccess(true)
@@ -1086,7 +1105,7 @@ public AclStatus getAclStatus(final Path path) throws IOException {
               client.getFileSystem(),
               path.toString());
 
-      AbfsRestOperation op = client.getAclStatus(AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true));
+      AbfsRestOperation op = client.getAclStatus(getRelativePath(path));
       AbfsHttpOperation result = op.getResult();
       perfInfo.registerResult(result);
 
@@ -1130,10 +1149,8 @@ public void access(final Path path, final FsAction mode)
       return;
     }
     try (AbfsPerfInfo perfInfo = startTracking("access", "checkAccess")) {
-      String relativePath =
-          AbfsHttpConstants.FORWARD_SLASH + getRelativePath(path, true);
       final AbfsRestOperation op = this.client
-          .checkAccess(relativePath, mode.SYMBOL);
+          .checkAccess(getRelativePath(path), mode.SYMBOL);
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
     }
   }
@@ -1201,22 +1218,8 @@ private String getOctalNotation(FsPermission fsPermission) {
   }
 
   private String getRelativePath(final Path path) {
-    return getRelativePath(path, false);
-  }
-
-  private String getRelativePath(final Path path, final boolean allowRootPath) {
     Preconditions.checkNotNull(path, "path");
-    final String relativePath = path.toUri().getPath();
+    return path.toUri().getPath();
-
-    if (relativePath.length() == 0 || (relativePath.length() == 1 && relativePath.charAt(0) == Path.SEPARATOR_CHAR)) {
-      return allowRootPath ? AbfsHttpConstants.ROOT_PATH : AbfsHttpConstants.EMPTY_STRING;
-    }
-
-    if (relativePath.charAt(0) == Path.SEPARATOR_CHAR) {
-      return relativePath.substring(1);
-    }
-
-    return relativePath;
   }
 
   private long parseContentLength(final String contentLength) {

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/constants/ConfigurationKeys.java

@@ -142,5 +142,8 @@ public static String accountProperty(String property, String account) {
   /** Key for SAS token provider **/
   public static final String FS_AZURE_SAS_TOKEN_PROVIDER_TYPE = "fs.azure.sas.token.provider.type";
 
+  /** For performance, AbfsInputStream/AbfsOutputStream re-use SAS tokens until the expiry is within this number of seconds. **/
+  public static final String FS_AZURE_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS = "fs.azure.sas.token.renew.period.for.streams";
+
   private ConfigurationKeys() {}
 }

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/constants/FileSystemConfigurations.java

@@ -76,6 +76,7 @@ public final class FileSystemConfigurations {
   public static final boolean DEFAULT_USE_UPN = false;
   public static final boolean DEFAULT_ENABLE_CHECK_ACCESS = false;
   public static final boolean DEFAULT_ABFS_LATENCY_TRACK = false;
+  public static final long DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS = 120;
 
   public static final String DEFAULT_FS_AZURE_USER_AGENT_PREFIX = EMPTY_STRING;
   public static final String DEFAULT_VALUE_UNKNOWN = "UNKNOWN";

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/extensions/SASTokenProvider.java

@@ -32,22 +32,23 @@
 @InterfaceStability.Unstable
 public interface SASTokenProvider {
 
-  String CONCAT_SOURCE_OPERATION = "concat-source";
+  String CHECK_ACCESS_OPERATION = "check-access";
-  String CONCAT_TARGET_OPERATION = "concat-target";
+  String CREATE_FILE_OPERATION = "create-file";
-  String CREATEFILE_OPERATION = "create";
   String DELETE_OPERATION = "delete";
-  String EXECUTE_OPERATION = "execute";
+  String DELETE_RECURSIVE_OPERATION = "delete-recursive";
-  String GETACL_OPERATION = "getaclstatus";
+  String GET_ACL_OPERATION = "get-acl";
-  String GETFILESTATUS_OPERATION = "getfilestatus";
+  String GET_STATUS_OPERATION = "get-status";
-  String LISTSTATUS_OPERATION = "liststatus";
+  String GET_PROPERTIES_OPERATION = "get-properties";
-  String MKDIR_OPERATION = "mkdir";
+  String LIST_OPERATION = "list";
+  String CREATE_DIRECTORY_OPERATION = "create-directory";
   String READ_OPERATION = "read";
   String RENAME_SOURCE_OPERATION = "rename-source";
   String RENAME_DESTINATION_OPERATION = "rename-destination";
-  String SETACL_OPERATION = "setacl";
+  String SET_ACL_OPERATION = "set-acl";
-  String SETOWNER_OPERATION = "setowner";
+  String SET_OWNER_OPERATION = "set-owner";
-  String SETPERMISSION_OPERATION = "setpermission";
+  String SET_PERMISSION_OPERATION = "set-permission";
-  String APPEND_OPERATION = "write";
+  String SET_PROPERTIES_OPERATION = "set-properties";
+  String WRITE_OPERATION = "write";
 
   /**
    * Initialize authorizer for Azure Blob File System.

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/oauth2/AzureADAuthenticator.java

@@ -52,6 +52,7 @@ public final class AzureADAuthenticator {
 
   private static final Logger LOG = LoggerFactory.getLogger(AzureADAuthenticator.class);
   private static final String RESOURCE_NAME = "https://storage.azure.com/";
+  private static final String SCOPE = "https://storage.azure.com/.default";
   private static final int CONNECT_TIMEOUT = 30 * 1000;
   private static final int READ_TIMEOUT = 30 * 1000;
 
@@ -85,9 +86,14 @@ public static AzureADToken getTokenUsingClientCreds(String authEndpoint,
     Preconditions.checkNotNull(authEndpoint, "authEndpoint");
     Preconditions.checkNotNull(clientId, "clientId");
     Preconditions.checkNotNull(clientSecret, "clientSecret");
+    boolean isVersion2AuthenticationEndpoint = authEndpoint.contains("/oauth2/v2.0/");
 
     QueryParams qp = new QueryParams();
-    qp.add("resource", RESOURCE_NAME);
+    if (isVersion2AuthenticationEndpoint) {
+      qp.add("scope", SCOPE);
+    } else {
+      qp.add("resource", RESOURCE_NAME);
+    }
     qp.add("grant_type", "client_credentials");
     qp.add("client_id", clientId);
     qp.add("client_secret", clientSecret);

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsClient.java

@@ -29,6 +29,7 @@
 import java.util.Locale;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Strings;
 import org.apache.hadoop.security.ssl.DelegatingSSLSocketFactory;
 import org.apache.hadoop.fs.azurebfs.constants.AbfsHttpConstants;
 import org.apache.hadoop.fs.azurebfs.constants.HttpHeaderConfigurations;
@@ -207,13 +208,12 @@ public AbfsRestOperation listPath(final String relativePath, final boolean recur
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_RESOURCE, FILESYSTEM);
-    abfsUriQueryBuilder.addQuery(QUERY_PARAM_DIRECTORY, relativePath == null ? AbfsHttpConstants.EMPTY_STRING
+    abfsUriQueryBuilder.addQuery(QUERY_PARAM_DIRECTORY, getDirectoryQueryParameter(relativePath));
-        : relativePath);
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_RECURSIVE, String.valueOf(recursive));
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_CONTINUATION, continuation);
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_MAXRESULTS, String.valueOf(listMaxResults));
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_UPN, String.valueOf(abfsConfiguration.isUpnUsed()));
-    appendSASTokenToQuery(relativePath, SASTokenProvider.LISTSTATUS_OPERATION, abfsUriQueryBuilder);
+    appendSASTokenToQuery(relativePath, SASTokenProvider.LIST_OPERATION, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -279,8 +279,8 @@ public AbfsRestOperation createPath(final String path, final boolean isFile, fin
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_RESOURCE, isFile ? FILE : DIRECTORY);
 
     String operation = isFile
-        ? SASTokenProvider.CREATEFILE_OPERATION
+        ? SASTokenProvider.CREATE_FILE_OPERATION
-        : SASTokenProvider.MKDIR_OPERATION;
+        : SASTokenProvider.CREATE_DIRECTORY_OPERATION;
     appendSASTokenToQuery(path, operation, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
@@ -325,7 +325,7 @@ public AbfsRestOperation renamePath(String source, final String destination, fin
   }
 
   public AbfsRestOperation append(final String path, final long position, final byte[] buffer, final int offset,
-                                  final int length) throws AzureBlobFileSystemException {
+                                  final int length, final String cachedSasToken) throws AzureBlobFileSystemException {
     final List<AbfsHttpHeader> requestHeaders = createDefaultHeaders();
     // JDK7 does not support PATCH, so to workaround the issue we will use
     // PUT and specify the real method in the X-Http-Method-Override header.
@@ -335,7 +335,9 @@ public AbfsRestOperation append(final String path, final long position, final by
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_ACTION, APPEND_ACTION);
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_POSITION, Long.toString(position));
-    appendSASTokenToQuery(path, SASTokenProvider.APPEND_OPERATION, abfsUriQueryBuilder);
+    // AbfsInputStream/AbfsOutputStream reuse SAS tokens for better performance
+    String sasTokenForReuse = appendSASTokenToQuery(path, SASTokenProvider.WRITE_OPERATION,
+        abfsUriQueryBuilder, cachedSasToken);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -343,12 +345,13 @@ public AbfsRestOperation append(final String path, final long position, final by
             this,
             HTTP_METHOD_PUT,
             url,
-            requestHeaders, buffer, offset, length);
+            requestHeaders, buffer, offset, length, sasTokenForReuse);
     op.execute();
     return op;
   }
 
-  public AbfsRestOperation flush(final String path, final long position, boolean retainUncommittedData, boolean isClose)
+  public AbfsRestOperation flush(final String path, final long position, boolean retainUncommittedData,
+                                 boolean isClose, final String cachedSasToken)
       throws AzureBlobFileSystemException {
     final List<AbfsHttpHeader> requestHeaders = createDefaultHeaders();
     // JDK7 does not support PATCH, so to workaround the issue we will use
@@ -361,7 +364,9 @@ public AbfsRestOperation flush(final String path, final long position, boolean r
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_POSITION, Long.toString(position));
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_RETAIN_UNCOMMITTED_DATA, String.valueOf(retainUncommittedData));
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_CLOSE, String.valueOf(isClose));
-    appendSASTokenToQuery(path, SASTokenProvider.APPEND_OPERATION, abfsUriQueryBuilder);
+    // AbfsInputStream/AbfsOutputStream reuse SAS tokens for better performance
+    String sasTokenForReuse = appendSASTokenToQuery(path, SASTokenProvider.WRITE_OPERATION,
+        abfsUriQueryBuilder, cachedSasToken);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -369,7 +374,7 @@ public AbfsRestOperation flush(final String path, final long position, boolean r
             this,
             HTTP_METHOD_PUT,
             url,
-            requestHeaders);
+            requestHeaders, sasTokenForReuse);
     op.execute();
     return op;
   }
@@ -386,6 +391,7 @@ public AbfsRestOperation setPathProperties(final String path, final String prope
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_ACTION, SET_PROPERTIES_ACTION);
+    appendSASTokenToQuery(path, SASTokenProvider.SET_PROPERTIES_OPERATION, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -398,12 +404,20 @@ public AbfsRestOperation setPathProperties(final String path, final String prope
     return op;
   }
 
-  public AbfsRestOperation getPathStatus(final String path) throws AzureBlobFileSystemException {
+  public AbfsRestOperation getPathStatus(final String path, final boolean includeProperties) throws AzureBlobFileSystemException {
     final List<AbfsHttpHeader> requestHeaders = createDefaultHeaders();
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
+    String operation = SASTokenProvider.GET_PROPERTIES_OPERATION;
+    if (!includeProperties) {
+      // The default action (operation) is implicitly to get properties and this action requires read permission
+      // because it reads user defined properties.  If the action is getStatus or getAclStatus, then
+      // only traversal (execute) permission is required.
+      abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_ACTION, AbfsHttpConstants.GET_STATUS);
+      operation = SASTokenProvider.GET_STATUS_OPERATION;
+    }
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_UPN, String.valueOf(abfsConfiguration.isUpnUsed()));
-    appendSASTokenToQuery(path, SASTokenProvider.GETFILESTATUS_OPERATION, abfsUriQueryBuilder);
+    appendSASTokenToQuery(path, operation, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -417,14 +431,16 @@ public AbfsRestOperation getPathStatus(final String path) throws AzureBlobFileSy
   }
 
   public AbfsRestOperation read(final String path, final long position, final byte[] buffer, final int bufferOffset,
-                                final int bufferLength, final String eTag) throws AzureBlobFileSystemException {
+                                final int bufferLength, final String eTag, String cachedSasToken) throws AzureBlobFileSystemException {
     final List<AbfsHttpHeader> requestHeaders = createDefaultHeaders();
     requestHeaders.add(new AbfsHttpHeader(RANGE,
             String.format("bytes=%d-%d", position, position + bufferLength - 1)));
     requestHeaders.add(new AbfsHttpHeader(IF_MATCH, eTag));
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
-    appendSASTokenToQuery(path, SASTokenProvider.READ_OPERATION, abfsUriQueryBuilder);
+    // AbfsInputStream/AbfsOutputStream reuse SAS tokens for better performance
+    String sasTokenForReuse = appendSASTokenToQuery(path, SASTokenProvider.READ_OPERATION,
+        abfsUriQueryBuilder, cachedSasToken);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
 
@@ -436,7 +452,7 @@ public AbfsRestOperation read(final String path, final long position, final byte
             requestHeaders,
             buffer,
             bufferOffset,
-            bufferLength);
+            bufferLength, sasTokenForReuse);
     op.execute();
 
     return op;
@@ -449,7 +465,8 @@ public AbfsRestOperation deletePath(final String path, final boolean recursive,
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_RECURSIVE, String.valueOf(recursive));
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_CONTINUATION, continuation);
-    appendSASTokenToQuery(path, SASTokenProvider.DELETE_OPERATION, abfsUriQueryBuilder);
+    String operation = recursive ? SASTokenProvider.DELETE_RECURSIVE_OPERATION : SASTokenProvider.DELETE_OPERATION;
+    appendSASTokenToQuery(path, operation, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -479,7 +496,7 @@ public AbfsRestOperation setOwner(final String path, final String owner, final S
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_ACTION, AbfsHttpConstants.SET_ACCESS_CONTROL);
-    appendSASTokenToQuery(path, SASTokenProvider.SETOWNER_OPERATION, abfsUriQueryBuilder);
+    appendSASTokenToQuery(path, SASTokenProvider.SET_OWNER_OPERATION, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -504,7 +521,7 @@ public AbfsRestOperation setPermission(final String path, final String permissio
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_ACTION, AbfsHttpConstants.SET_ACCESS_CONTROL);
-    appendSASTokenToQuery(path, SASTokenProvider.SETPERMISSION_OPERATION, abfsUriQueryBuilder);
+    appendSASTokenToQuery(path, SASTokenProvider.SET_PERMISSION_OPERATION, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -537,7 +554,7 @@ public AbfsRestOperation setAcl(final String path, final String aclSpecString, f
 
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_ACTION, AbfsHttpConstants.SET_ACCESS_CONTROL);
-    appendSASTokenToQuery(path, SASTokenProvider.SETACL_OPERATION, abfsUriQueryBuilder);
+    appendSASTokenToQuery(path, SASTokenProvider.SET_ACL_OPERATION, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -560,7 +577,7 @@ public AbfsRestOperation getAclStatus(final String path, final boolean useUPN) t
     final AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_ACTION, AbfsHttpConstants.GET_ACCESS_CONTROL);
     abfsUriQueryBuilder.addQuery(HttpQueryParams.QUERY_PARAM_UPN, String.valueOf(useUPN));
-    appendSASTokenToQuery(path, SASTokenProvider.GETACL_OPERATION, abfsUriQueryBuilder);
+    appendSASTokenToQuery(path, SASTokenProvider.GET_ACL_OPERATION, abfsUriQueryBuilder);
 
     final URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     final AbfsRestOperation op = new AbfsRestOperation(
@@ -587,6 +604,7 @@ public AbfsRestOperation checkAccess(String path, String rwx)
     AbfsUriQueryBuilder abfsUriQueryBuilder = createDefaultUriQueryBuilder();
     abfsUriQueryBuilder.addQuery(QUERY_PARAM_ACTION, CHECK_ACCESS);
     abfsUriQueryBuilder.addQuery(QUERY_FS_ACTION, rwx);
+    appendSASTokenToQuery(path, SASTokenProvider.CHECK_ACCESS_OPERATION, abfsUriQueryBuilder);
     URL url = createRequestUrl(path, abfsUriQueryBuilder.toString());
     AbfsRestOperation op = new AbfsRestOperation(
         AbfsRestOperationType.CheckAccess, this,
@@ -595,23 +613,65 @@ public AbfsRestOperation checkAccess(String path, String rwx)
     return op;
   }
 
+  /**
+   * Get the directory query parameter used by the List Paths REST API and used
+   * as the path in the continuation token.  If the input path is null or the
+   * root path "/", empty string is returned. If the input path begins with '/',
+   * the return value is the substring beginning at offset 1.  Otherwise, the
+   * input path is returned.
+   * @param path the path to be listed.
+   * @return the value of the directory query parameter
+   */
+  public static String getDirectoryQueryParameter(final String path) {
+    String directory = path;
+    if (Strings.isNullOrEmpty(directory)) {
+      directory = AbfsHttpConstants.EMPTY_STRING;
+    } else if (directory.charAt(0) == '/') {
+      directory = directory.substring(1);
+    }
+    return directory;
+  }
+
   /**
    * If configured for SAS AuthType, appends SAS token to queryBuilder
    * @param path
    * @param operation
    * @param queryBuilder
+   * @return sasToken - returned for optional re-use.
    * @throws SASTokenProviderException
    */
-  private void appendSASTokenToQuery(String path, String operation, AbfsUriQueryBuilder queryBuilder) throws SASTokenProviderException {
+  private String appendSASTokenToQuery(String path, String operation, AbfsUriQueryBuilder queryBuilder) throws SASTokenProviderException {
+    return appendSASTokenToQuery(path, operation, queryBuilder, null);
+  }
+
+  /**
+   * If configured for SAS AuthType, appends SAS token to queryBuilder
+   * @param path
+   * @param operation
+   * @param queryBuilder
+   * @param cachedSasToken - previously acquired SAS token to be reused.
+   * @return sasToken - returned for optional re-use.
+   * @throws SASTokenProviderException
+   */
+  private String appendSASTokenToQuery(String path,
+                                       String operation,
+                                       AbfsUriQueryBuilder queryBuilder,
+                                       String cachedSasToken)
+      throws SASTokenProviderException {
+    String sasToken = null;
     if (this.authType == AuthType.SAS) {
       try {
         LOG.trace("Fetch SAS token for {} on {}", operation, path);
-        String sasToken = sasTokenProvider.getSASToken(this.accountName,
+        if (cachedSasToken == null) {
-            this.filesystem, path, operation);
+          sasToken = sasTokenProvider.getSASToken(this.accountName,
-        if ((sasToken == null) || sasToken.isEmpty()) {
+              this.filesystem, path, operation);
-          throw new UnsupportedOperationException("SASToken received is empty or null");
+          if ((sasToken == null) || sasToken.isEmpty()) {
+            throw new UnsupportedOperationException("SASToken received is empty or null");
+          }
+        } else {
+          sasToken = cachedSasToken;
+          LOG.trace("Using cached SAS token.");
         }
-
         queryBuilder.setSASToken(sasToken);
         LOG.trace("SAS token fetch complete for {} on {}", operation, path);
       } catch (Exception ex) {
@@ -621,6 +681,7 @@ private void appendSASTokenToQuery(String path, String operation, AbfsUriQueryBu
             ex.toString()));
       }
     }
+    return sasToken;
   }
 
   private URL createRequestUrl(final String query) throws AzureBlobFileSystemException {

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsInputStream.java

@@ -32,6 +32,7 @@
 import org.apache.hadoop.fs.StreamCapabilities;
 import org.apache.hadoop.fs.azurebfs.contracts.exceptions.AbfsRestOperationException;
 import org.apache.hadoop.fs.azurebfs.contracts.exceptions.AzureBlobFileSystemException;
+import org.apache.hadoop.fs.azurebfs.utils.CachedSASToken;
 
 import static org.apache.hadoop.util.StringUtils.toLowerCase;
 
@@ -51,6 +52,8 @@ public class AbfsInputStream extends FSInputStream implements CanUnbuffer,
   private final boolean tolerateOobAppends; // whether tolerate Oob Appends
   private final boolean readAheadEnabled; // whether enable readAhead;
 
+  // SAS tokens can be re-used until they expire
+  private CachedSASToken cachedSasToken;
   private byte[] buffer = null;            // will be initialized on first use
 
   private long fCursor = 0;  // cursor of buffer within file - offset of next byte to read from remote server
@@ -76,6 +79,8 @@ public AbfsInputStream(
     this.tolerateOobAppends = abfsInputStreamContext.isTolerateOobAppends();
     this.eTag = eTag;
     this.readAheadEnabled = true;
+    this.cachedSasToken = new CachedSASToken(
+        abfsInputStreamContext.getSasTokenRenewPeriodForStreamsInSeconds());
   }
 
   public String getPath() {
@@ -234,7 +239,8 @@ int readRemote(long position, byte[] b, int offset, int length) throws IOExcepti
     final AbfsRestOperation op;
     AbfsPerfTracker tracker = client.getAbfsPerfTracker();
     try (AbfsPerfInfo perfInfo = new AbfsPerfInfo(tracker, "readRemote", "read")) {
-      op = client.read(path, position, b, offset, length, tolerateOobAppends ? "*" : eTag);
+      op = client.read(path, position, b, offset, length, tolerateOobAppends ? "*" : eTag, cachedSasToken.get());
+      cachedSasToken.update(op.getSasToken());
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
       incrementReadOps();
     } catch (AzureBlobFileSystemException ex) {

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsInputStreamContext.java

@@ -29,7 +29,8 @@ public class AbfsInputStreamContext extends AbfsStreamContext {
 
   private boolean tolerateOobAppends;
 
-  public AbfsInputStreamContext() {
+  public AbfsInputStreamContext(final long sasTokenRenewPeriodForStreamsInSeconds) {
+    super(sasTokenRenewPeriodForStreamsInSeconds);
   }
 
   public AbfsInputStreamContext withReadBufferSize(final int readBufferSize) {

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsOutputStream.java

@@ -40,6 +40,7 @@
 
 import org.apache.hadoop.fs.azurebfs.contracts.exceptions.AbfsRestOperationException;
 import org.apache.hadoop.fs.azurebfs.contracts.exceptions.AzureBlobFileSystemException;
+import org.apache.hadoop.fs.azurebfs.utils.CachedSASToken;
 import org.apache.hadoop.io.ElasticByteBufferPool;
 import org.apache.hadoop.fs.FileSystem.Statistics;
 import org.apache.hadoop.fs.FSExceptionMessages;
@@ -73,6 +74,9 @@ public class AbfsOutputStream extends OutputStream implements Syncable, StreamCa
   private final ThreadPoolExecutor threadExecutor;
   private final ExecutorCompletionService<Void> completionService;
 
+  // SAS tokens can be re-used until they expire
+  private CachedSASToken cachedSasToken;
+
   /**
    * Queue storing buffers with the size of the Azure block ready for
    * reuse. The pool allows reusing the blocks instead of allocating new
@@ -119,6 +123,8 @@ public AbfsOutputStream(
         TimeUnit.SECONDS,
         new LinkedBlockingQueue<>());
     this.completionService = new ExecutorCompletionService<>(this.threadExecutor);
+    this.cachedSasToken = new CachedSASToken(
+        abfsOutputStreamContext.getSasTokenRenewPeriodForStreamsInSeconds());
   }
 
   /**
@@ -330,7 +336,8 @@ public Void call() throws Exception {
         try (AbfsPerfInfo perfInfo = new AbfsPerfInfo(tracker,
                 "writeCurrentBufferToService", "append")) {
           AbfsRestOperation op = client.append(path, offset, bytes, 0,
-                  bytesLength);
+                  bytesLength, cachedSasToken.get());
+          cachedSasToken.update(op.getSasToken());
           perfInfo.registerResult(op.getResult());
           byteBufferPool.putBuffer(ByteBuffer.wrap(bytes));
           perfInfo.registerSuccess(true);
@@ -385,7 +392,8 @@ private synchronized void flushWrittenBytesToServiceInternal(final long offset,
     AbfsPerfTracker tracker = client.getAbfsPerfTracker();
     try (AbfsPerfInfo perfInfo = new AbfsPerfInfo(tracker,
             "flushWrittenBytesToServiceInternal", "flush")) {
-      AbfsRestOperation op = client.flush(path, offset, retainUncommitedData, isClose);
+      AbfsRestOperation op = client.flush(path, offset, retainUncommitedData, isClose, cachedSasToken.get());
+      cachedSasToken.update(op.getSasToken());
       perfInfo.registerResult(op.getResult()).registerSuccess(true);
     } catch (AzureBlobFileSystemException ex) {
       if (ex instanceof AbfsRestOperationException) {

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsOutputStreamContext.java

@@ -31,7 +31,8 @@ public class AbfsOutputStreamContext extends AbfsStreamContext {
 
   private AbfsOutputStreamStatistics streamStatistics;
 
-  public AbfsOutputStreamContext() {
+  public AbfsOutputStreamContext(final long sasTokenRenewPeriodForStreamsInSeconds) {
+    super(sasTokenRenewPeriodForStreamsInSeconds);
   }
 
   public AbfsOutputStreamContext withWriteBufferSize(

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsRestOperation.java

@@ -53,6 +53,9 @@ public class AbfsRestOperation {
   // request body and all the download methods have a response body.
   private final boolean hasRequestBody;
 
+  // Used only by AbfsInputStream/AbfsOutputStream to reuse SAS tokens.
+  private final String sasToken;
+
   private static final Logger LOG = LoggerFactory.getLogger(AbfsClient.class);
 
   // For uploads, this is the request entity body.  For downloads,
@@ -67,6 +70,10 @@ public AbfsHttpOperation getResult() {
     return result;
   }
 
+  String getSasToken() {
+    return sasToken;
+  }
+
   /**
    * Initializes a new REST operation.
    *
@@ -80,6 +87,24 @@ public AbfsHttpOperation getResult() {
                     final String method,
                     final URL url,
                     final List<AbfsHttpHeader> requestHeaders) {
+    this(operationType, client, method, url, requestHeaders, null);
+  }
+
+  /**
+   * Initializes a new REST operation.
+   *
+   * @param client The Blob FS client.
+   * @param method The HTTP method (PUT, PATCH, POST, GET, HEAD, or DELETE).
+   * @param url The full URL including query string parameters.
+   * @param requestHeaders The HTTP request headers.
+   * @param sasToken A sasToken for optional re-use by AbfsInputStream/AbfsOutputStream.
+   */
+  AbfsRestOperation(final AbfsRestOperationType operationType,
+                    final AbfsClient client,
+                    final String method,
+                    final URL url,
+                    final List<AbfsHttpHeader> requestHeaders,
+                    final String sasToken) {
     this.operationType = operationType;
     this.client = client;
     this.method = method;
@@ -87,6 +112,7 @@ public AbfsHttpOperation getResult() {
     this.requestHeaders = requestHeaders;
     this.hasRequestBody = (AbfsHttpConstants.HTTP_METHOD_PUT.equals(method)
             || AbfsHttpConstants.HTTP_METHOD_PATCH.equals(method));
+    this.sasToken = sasToken;
   }
 
   /**
@@ -101,6 +127,7 @@ public AbfsHttpOperation getResult() {
    *               this will hold the response entity body.
    * @param bufferOffset An offset into the buffer where the data beings.
    * @param bufferLength The length of the data in the buffer.
+   * @param sasToken A sasToken for optional re-use by AbfsInputStream/AbfsOutputStream.
    */
   AbfsRestOperation(AbfsRestOperationType operationType,
                     AbfsClient client,
@@ -109,8 +136,9 @@ public AbfsHttpOperation getResult() {
                     List<AbfsHttpHeader> requestHeaders,
                     byte[] buffer,
                     int bufferOffset,
-                    int bufferLength) {
+                    int bufferLength,
-    this(operationType, client, method, url, requestHeaders);
+                    String sasToken) {
+    this(operationType, client, method, url, requestHeaders, sasToken);
     this.buffer = buffer;
     this.bufferOffset = bufferOffset;
     this.bufferLength = bufferLength;

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsStreamContext.java

@@ -23,4 +23,17 @@
  * to store common configs among input and output streams.
  */
 public abstract class AbfsStreamContext {
+  private long sasTokenRenewPeriodForStreamsInSeconds;
+
+  // hide default constructor
+  private AbfsStreamContext() {
+  }
+
+  public AbfsStreamContext(final long sasTokenRenewPeriodForStreamsInSeconds) {
+    this.sasTokenRenewPeriodForStreamsInSeconds = sasTokenRenewPeriodForStreamsInSeconds;
+  }
+
+  public long getSasTokenRenewPeriodForStreamsInSeconds() {
+    return sasTokenRenewPeriodForStreamsInSeconds;
+  }
 }

hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/utils/CachedSASToken.java

@@ -0,0 +1,207 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.azurebfs.utils;
+
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+
+import com.google.common.annotations.VisibleForTesting;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS;
+import static java.time.temporal.ChronoUnit.SECONDS;
+
+/**
+ * CachedSASToken provides simple utility for managing renewal
+ * of SAS tokens used by Input/OutputStream.  This enables SAS re-use
+ * and reduces calls to the SASTokenProvider.
+ */
+public final class CachedSASToken {
+  public static final Logger LOG = LoggerFactory.getLogger(CachedSASToken.class);
+  private final long minExpirationInSeconds;
+  private String sasToken;
+  private OffsetDateTime sasExpiry;
+
+  /**
+   * Create instance with default minimum expiration.  SAS tokens are
+   * automatically renewed when their expiration is within this period.
+   */
+  public CachedSASToken() {
+    this(DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS);
+  }
+
+  /**
+   * Create instance with specified minimum expiration.  SAS tokens are
+   * automatically renewed when their expiration is within this period.
+   * @param minExpirationInSeconds
+   */
+  public CachedSASToken(long minExpirationInSeconds) {
+    this.minExpirationInSeconds = minExpirationInSeconds;
+  }
+
+  /**
+   * Checks if the SAS token is expired or near expiration.
+   * @param expiry
+   * @param minExpiryInSeconds
+   * @return true if the SAS is near sasExpiry; otherwise false
+   */
+  private static boolean isNearExpiry(OffsetDateTime expiry, long minExpiryInSeconds) {
+    if (expiry == OffsetDateTime.MIN) {
+      return true;
+    }
+    OffsetDateTime utcNow = OffsetDateTime.now(ZoneOffset.UTC);
+    return utcNow.until(expiry, SECONDS) <= minExpiryInSeconds;
+  }
+
+  /**
+   * Parse the sasExpiry from the SAS token.  The sasExpiry is the minimum
+   * of the ske and se parameters.  The se parameter is required and the
+   * ske parameter is optional.
+   * @param token an Azure Storage SAS token
+   * @return the sasExpiry or OffsetDateTime.MIN if invalid.
+   */
+  private static OffsetDateTime getExpiry(String token) {
+    // return MIN for all invalid input, including a null token
+    if (token == null) {
+      return OffsetDateTime.MIN;
+    }
+
+    String signedExpiry = "se=";
+    int signedExpiryLen = 3;
+
+    int start = token.indexOf(signedExpiry);
+
+    // return MIN if the required se parameter is absent
+    if (start == -1) {
+      return OffsetDateTime.MIN;
+    }
+
+    start += signedExpiryLen;
+
+    // extract the value of se parameter
+    int end = token.indexOf("&", start);
+    String seValue = (end == -1) ? token.substring(start) : token.substring(start, end);
+
+    try {
+      seValue = URLDecoder.decode(seValue, "utf-8");
+    } catch (UnsupportedEncodingException ex) {
+      LOG.error("Error decoding se query parameter ({}) from SAS.", seValue, ex);
+      return OffsetDateTime.MIN;
+    }
+
+    // parse the ISO 8601 date value; return MIN if invalid
+    OffsetDateTime seDate = OffsetDateTime.MIN;
+    try {
+      seDate = OffsetDateTime.parse(seValue, DateTimeFormatter.ISO_DATE_TIME);
+    } catch (DateTimeParseException ex) {
+      LOG.error("Error parsing se query parameter ({}) from SAS.", seValue, ex);
+    }
+
+    String signedKeyExpiry = "ske=";
+    int signedKeyExpiryLen = 4;
+
+    // if ske is present, the sasExpiry is the minimum of ske and se
+    start = token.indexOf(signedKeyExpiry);
+
+    // return seDate if ske is absent
+    if (start == -1) {
+      return seDate;
+    }
+
+    start += signedKeyExpiryLen;
+
+    // extract the value of ske parameter
+    end = token.indexOf("&", start);
+    String skeValue = (end == -1) ? token.substring(start) : token.substring(start, end);
+
+    try {
+      skeValue = URLDecoder.decode(skeValue, "utf-8");
+    } catch (UnsupportedEncodingException ex) {
+      LOG.error("Error decoding ske query parameter ({}) from SAS.", skeValue, ex);
+      return OffsetDateTime.MIN;
+    }
+
+    // parse the ISO 8601 date value; return MIN if invalid
+    OffsetDateTime skeDate = OffsetDateTime.MIN;
+    try {
+      skeDate = OffsetDateTime.parse(skeValue, DateTimeFormatter.ISO_DATE_TIME);
+    } catch (DateTimeParseException ex) {
+      LOG.error("Error parsing ske query parameter ({}) from SAS.", skeValue, ex);
+      return OffsetDateTime.MIN;
+    }
+
+    return skeDate.isBefore(seDate) ? skeDate : seDate;
+  }
+
+  /**
+   * Updates the cached SAS token and expiry.  If the token is invalid, the cached value
+   * is cleared by setting it to null and the expiry to MIN.
+   * @param token an Azure Storage SAS token
+   */
+  public void update(String token) {
+    // quickly return if token and cached sasToken are the same reference
+    // Note: use of operator == is intentional
+    if (token == sasToken) {
+      return;
+    }
+    OffsetDateTime newExpiry = getExpiry(token);
+    boolean isInvalid = isNearExpiry(newExpiry, minExpirationInSeconds);
+    synchronized (this) {
+      if (isInvalid) {
+        sasToken = null;
+        sasExpiry = OffsetDateTime.MIN;
+      } else {
+        sasToken = token;
+        sasExpiry = newExpiry;
+      }
+    }
+  }
+
+  /**
+   * Gets the token if still valid.
+   * @return the token or null if it is expired or near sasExpiry.
+   */
+  public String get() {
+    // quickly return null if not set
+    if (sasToken == null) {
+      return null;
+    }
+    String token;
+    OffsetDateTime exp;
+    synchronized (this) {
+      token = sasToken;
+      exp = sasExpiry;
+    }
+    boolean isInvalid = isNearExpiry(exp, minExpirationInSeconds);
+    return isInvalid ? null : token;
+  }
+
+  @VisibleForTesting
+  void setForTesting(String token, OffsetDateTime expiry) {
+    synchronized (this) {
+      sasToken = token;
+      sasExpiry = expiry;
+    }
+  }
+}

hadoop-tools/hadoop-azure/src/site/markdown/abfs.md

@@ -313,6 +313,7 @@ driven by them.
 1. Using OAuth 2.0 tokens of one form or another.
 1. Deployed in-Azure with the Azure VMs providing OAuth 2.0 tokens to the application,
  "Managed Instance".
+1. Using Shared Access Signature (SAS) tokens provided by a custom implementation of the SASTokenProvider interface.
 
 What can be changed is what secrets/credentials are used to authenticate the caller.
 
@@ -541,6 +542,24 @@ and optionally `org.apache.hadoop.fs.azurebfs.extensions.BoundDTExtension`.
 
 The declared class also holds responsibility to implement retry logic while fetching access tokens.
 
+### Shared Access Signature (SAS) Token Provider
+
+A Shared Access Signature (SAS) token provider supplies the ABFS connector with SAS
+tokens by implementing the SASTokenProvider interface.
+
+```xml
+<property>
+  <name>fs.azure.account.auth.type</name>
+  <value>SAS</value>
+</property>
+<property>
+  <name>fs.azure.sas.token.provider.type</name>
+  <value>{fully-qualified-class-name-for-implementation-of-SASTokenProvider-interface}</value>
+</property>
+```
+
+The declared class must implement `org.apache.hadoop.fs.azurebfs.extensions.SASTokenProvider`.
+
 ## <a name="technical"></a> Technical notes
 
 ### <a name="proxy"></a> Proxy setup

hadoop-tools/hadoop-azure/src/site/markdown/testing_azure.md

@@ -646,7 +646,7 @@ hierarchical namespace enabled, and set the following configuration settings:
 <property>
   <name>fs.azure.account.auth.type.{YOUR_ABFS_ACCOUNT_NAME}</name>
   <value>{AUTH TYPE}</value>
-  <description>The authorization type can be SharedKey, OAuth, or Custom. The
+  <description>The authorization type can be SharedKey, OAuth, Custom or SAS. The
   default is SharedKey.</description>
 </property>
 
@@ -793,6 +793,79 @@ hierarchical namespace enabled, and set the following configuration settings:
     </property>
    -->
 
+```
+To run Delegation SAS test cases you must use a storage account with the
+hierarchical namespace enabled and set the following configuration settings:
+
+```xml
+<!--=========================== AUTHENTICATION  OPTIONS ===================-->
+<!--=============================   FOR SAS   ===========================-->
+<!-- To run ABFS Delegation SAS tests, you must register an app, create the
+     necessary role assignments, and set the configuration discussed below:
+
+    1) Register an app:
+      a) Login to https://portal.azure.com, select your AAD directory and search for app registrations.
+      b) Click "New registration".
+      c) Provide a display name, such as "abfs-app".
+      d) Set the account type to "Accounts in this organizational directory only ({YOUR_Tenant} only - Single tenant)".
+      e) For Redirect URI select Web and enter "http://localhost".
+      f) Click Register.
+
+    2)  Create necessary role assignments:
+      a) Login to https://portal.azure.com and find the Storage account with hierarchical namespace enabled
+         that you plan to run the tests against.
+      b) Select "Access Control (IAM)".
+      c) Select Role Assignments
+      d) Click Add and select "Add role assignments"
+      e) For Role and enter "Storage Blob Data Owner".
+      f) Under Select enter the name of the app you registered in step 1 and select it.
+      g) Click Save.
+      h) Repeat above steps to create a second role assignment for the app but this time for
+         the "Storage Blob Delegator" role.
+
+    3) Generate a new client secret for the application:
+      a) Login to https://portal.azure.com and find the app registered in step 1.
+      b) Select "Certificates and secrets".
+      c) Click "New client secret".
+      d) Enter a description (eg. Secret1)
+      e) Set expiration period.  Expires in 1 year is good.
+      f) Click Add
+      g) Copy the secret and expiration to a safe location.
+
+    4) Set the following configuration values:
+-->
+
+  <property>
+    <name>fs.azure.sas.token.provider.type</name>
+    <value>org.apache.hadoop.fs.azurebfs.extensions.MockDelegationSASTokenProvider</value>
+    <description>The fully qualified class name of the SAS token provider implementation.</description>
+  </property>
+
+  <property>
+    <name>fs.azure.test.app.service.principal.tenant.id</name>
+    <value>{TID}</value>
+    <description>Tenant ID for the application's service principal.</description>
+  </property>
+
+  <property>
+    <name>fs.azure.test.app.service.principal.object.id</name>
+    <value>{OID}</value>
+    <description>Object ID for the application's service principal.</description>
+  </property>
+
+  <property>
+    <name>fs.azure.test.app.id</name>
+    <value>{app id}</value>
+    <description>The application's ID, also known as the client id.</description>
+  </property>
+
+   <property>
+     <name>fs.azure.test.app.secret</name>
+     <value>{client secret}</value>
+     <description>The application's secret, also known as the client secret.</description>
+   </property>
+
+
 ```
 
 If running tests against an endpoint that uses the URL format

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/AbstractAbfsIntegrationTest.java

@@ -26,6 +26,7 @@
 import java.util.concurrent.Callable;
 
 import org.junit.After;
+import org.junit.Assert;
 import org.junit.Before;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -79,6 +80,7 @@ public abstract class AbstractAbfsIntegrationTest extends
   private String testUrl;
   private AuthType authType;
   private boolean useConfiguredFileSystem = false;
+  private boolean usingFilesystemForSASTests = false;
 
   protected AbstractAbfsIntegrationTest() throws Exception {
     fileSystemName = TEST_CONTAINER_PREFIX + UUID.randomUUID().toString();
@@ -175,8 +177,13 @@ public void teardown() throws Exception {
         return;
       }
 
-      // Delete all uniquely created filesystem from the account
+      if (usingFilesystemForSASTests) {
-      if (!useConfiguredFileSystem) {
+        abfsConfig.set(FS_AZURE_ACCOUNT_AUTH_TYPE_PROPERTY_NAME, AuthType.SharedKey.name());
+        AzureBlobFileSystem tempFs = (AzureBlobFileSystem) FileSystem.newInstance(rawConfig);
+        tempFs.getAbfsStore().deleteFilesystem();
+      }
+      else if (!useConfiguredFileSystem) {
+        // Delete all uniquely created filesystem from the account
         final AzureBlobFileSystemStore abfsStore = abfs.getAbfsStore();
         abfsStore.deleteFilesystem();
 
@@ -225,6 +232,16 @@ public void loadConfiguredFileSystem() throws Exception {
     useConfiguredFileSystem = true;
   }
 
+  protected void createFilesystemForSASTests() throws Exception {
+    // The SAS tests do not have permission to create a filesystem
+    // so first create temporary instance of the filesystem using SharedKey
+    // then re-use the filesystem it creates with SAS auth instead of SharedKey.
+    AzureBlobFileSystem tempFs = (AzureBlobFileSystem) FileSystem.newInstance(rawConfig);
+    Assert.assertTrue(tempFs.exists(new Path("/")));
+    abfsConfig.set(FS_AZURE_ACCOUNT_AUTH_TYPE_PROPERTY_NAME, AuthType.SAS.name());
+    usingFilesystemForSASTests = true;
+  }
+
   public AzureBlobFileSystem getFileSystem() throws IOException {
     return abfs;
   }

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/ITestAzureBlobFileSystemAuthorization.java

@@ -209,46 +209,55 @@ public void testGetFileStatusUnauthorized() throws Exception {
 
   @Test
   public void testSetOwnerUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.SetOwner, true);
   }
 
   @Test
   public void testSetPermissionUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.SetPermissions, true);
   }
 
   @Test
   public void testModifyAclEntriesUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.ModifyAclEntries, true);
   }
 
   @Test
   public void testRemoveAclEntriesUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.RemoveAclEntries, true);
   }
 
   @Test
   public void testRemoveDefaultAclUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.RemoveDefaultAcl, true);
   }
 
   @Test
   public void testRemoveAclUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.RemoveAcl, true);
   }
 
   @Test
   public void testSetAclUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.SetAcl, true);
   }
 
   @Test
   public void testGetAclStatusAuthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.GetAcl, false);
   }
 
   @Test
   public void testGetAclStatusUnauthorized() throws Exception {
+    Assume.assumeTrue(this.getFileSystem().getIsNamespaceEnabled());
     runTest(FileSystemOperations.GetAcl, true);
   }
 

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/ITestAzureBlobFileSystemCheckAccess.java

@@ -273,6 +273,8 @@ private void assumeHNSAndCheckAccessEnabled() {
         isHNSEnabled);
     Assume.assumeTrue(FS_AZURE_ENABLE_CHECK_ACCESS + " is false",
         isCheckAccessEnabled);
+
+    Assume.assumeNotNull(getRawConfiguration().get(FS_AZURE_BLOB_FS_CLIENT_ID));
   }
 
   private void assertAccessible(Path testFilePath, FsAction fsAction)

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/ITestAzureBlobFileSystemDelegationSAS.java

@@ -0,0 +1,368 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.azurebfs;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.UUID;
+
+import org.junit.Assume;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.azurebfs.constants.AbfsHttpConstants;
+import org.apache.hadoop.fs.azurebfs.constants.TestConfigurationKeys;
+import org.apache.hadoop.fs.azurebfs.extensions.MockDelegationSASTokenProvider;
+import org.apache.hadoop.fs.azurebfs.services.AuthType;
+import org.apache.hadoop.fs.permission.AclEntry;
+import org.apache.hadoop.fs.permission.AclEntryScope;
+import org.apache.hadoop.fs.permission.AclStatus;
+import org.apache.hadoop.fs.permission.FsAction;
+import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.security.AccessControlException;
+
+import static org.apache.hadoop.fs.azurebfs.constants.ConfigurationKeys.FS_AZURE_SAS_TOKEN_PROVIDER_TYPE;
+import static org.apache.hadoop.fs.azurebfs.utils.AclTestHelpers.aclEntry;
+import static org.apache.hadoop.fs.permission.AclEntryScope.ACCESS;
+import static org.apache.hadoop.fs.permission.AclEntryScope.DEFAULT;
+import static org.apache.hadoop.fs.permission.AclEntryType.GROUP;
+import static org.apache.hadoop.fs.permission.AclEntryType.USER;
+
+/**
+ * Test Perform Authorization Check operation
+ */
+public class ITestAzureBlobFileSystemDelegationSAS extends AbstractAbfsIntegrationTest {
+  private static final String TEST_GROUP = UUID.randomUUID().toString();
+
+  private static final Logger LOG =
+      LoggerFactory.getLogger(ITestAzureBlobFileSystemDelegationSAS.class);
+
+  public ITestAzureBlobFileSystemDelegationSAS() throws Exception {
+    // These tests rely on specific settings in azure-auth-keys.xml:
+    String sasProvider = getRawConfiguration().get(FS_AZURE_SAS_TOKEN_PROVIDER_TYPE);
+    Assume.assumeTrue(MockDelegationSASTokenProvider.class.getCanonicalName().equals(sasProvider));
+    Assume.assumeNotNull(getRawConfiguration().get(TestConfigurationKeys.FS_AZURE_TEST_APP_ID));
+    Assume.assumeNotNull(getRawConfiguration().get(TestConfigurationKeys.FS_AZURE_TEST_APP_SECRET));
+    Assume.assumeNotNull(getRawConfiguration().get(TestConfigurationKeys.FS_AZURE_TEST_APP_SERVICE_PRINCIPAL_TENANT_ID));
+    Assume.assumeNotNull(getRawConfiguration().get(TestConfigurationKeys.FS_AZURE_TEST_APP_SERVICE_PRINCIPAL_OBJECT_ID));
+    // The test uses shared key to create a random filesystem and then creates another
+    // instance of this filesystem using SAS authorization.
+    Assume.assumeTrue(this.getAuthType() == AuthType.SharedKey);
+  }
+
+  @Override
+  public void setup() throws Exception {
+    boolean isHNSEnabled = this.getConfiguration().getBoolean(
+        TestConfigurationKeys.FS_AZURE_TEST_NAMESPACE_ENABLED_ACCOUNT, false);
+    Assume.assumeTrue(isHNSEnabled);
+    createFilesystemForSASTests();
+    super.setup();
+  }
+
+  @Test
+  // Test filesystem operations access, create, mkdirs, setOwner, getFileStatus
+  public void testCheckAccess() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+
+    Path rootPath = new Path("/");
+    fs.setPermission(rootPath, new FsPermission(FsAction.ALL, FsAction.READ_EXECUTE, FsAction.EXECUTE));
+    FileStatus rootStatus = fs.getFileStatus(rootPath);
+    assertEquals("The directory permissions are not expected.", "rwxr-x--x", rootStatus.getPermission().toString());
+
+    Path dirPath = new Path(UUID.randomUUID().toString());
+    fs.mkdirs(dirPath);
+    fs.setOwner(dirPath, MockDelegationSASTokenProvider.TEST_OWNER, null);
+
+    Path filePath = new Path(dirPath, "file1");
+    fs.create(filePath).close();
+    fs.setPermission(filePath, new FsPermission(FsAction.READ, FsAction.READ, FsAction.NONE));
+
+    FileStatus dirStatus = fs.getFileStatus(dirPath);
+    FileStatus fileStatus = fs.getFileStatus(filePath);
+
+    assertEquals("The owner is not expected.", MockDelegationSASTokenProvider.TEST_OWNER, dirStatus.getOwner());
+    assertEquals("The owner is not expected.", MockDelegationSASTokenProvider.TEST_OWNER, fileStatus.getOwner());
+    assertEquals("The directory permissions are not expected.", "rwxr-xr-x", dirStatus.getPermission().toString());
+    assertEquals("The file permissions are not expected.", "r--r-----", fileStatus.getPermission().toString());
+
+    assertTrue(isAccessible(fs, dirPath, FsAction.READ_WRITE));
+    assertFalse(isAccessible(fs, filePath, FsAction.READ_WRITE));
+
+    fs.setPermission(filePath, new FsPermission(FsAction.READ_WRITE, FsAction.READ, FsAction.NONE));
+    fileStatus = fs.getFileStatus(filePath);
+    assertEquals("The file permissions are not expected.", "rw-r-----", fileStatus.getPermission().toString());
+    assertTrue(isAccessible(fs, filePath, FsAction.READ_WRITE));
+
+    fs.setPermission(dirPath, new FsPermission(FsAction.EXECUTE, FsAction.NONE, FsAction.NONE));
+    dirStatus = fs.getFileStatus(dirPath);
+    assertEquals("The file permissions are not expected.", "--x------", dirStatus.getPermission().toString());
+    assertFalse(isAccessible(fs, dirPath, FsAction.READ_WRITE));
+    assertTrue(isAccessible(fs, dirPath, FsAction.EXECUTE));
+
+    fs.setPermission(dirPath, new FsPermission(FsAction.NONE, FsAction.NONE, FsAction.NONE));
+    dirStatus = fs.getFileStatus(dirPath);
+    assertEquals("The file permissions are not expected.", "---------", dirStatus.getPermission().toString());
+    assertFalse(isAccessible(fs, filePath, FsAction.READ_WRITE));
+  }
+
+  private boolean isAccessible(FileSystem fs, Path path, FsAction fsAction)
+      throws IOException {
+    try {
+      fs.access(path, fsAction);
+    } catch (AccessControlException ace) {
+      return false;
+    }
+    return true;
+  }
+
+  @Test
+  // Test filesystem operations create, create with overwrite, append and open.
+  // Test output stream operation write, flush and close
+  // Test input stream operation, read
+  public void testReadAndWrite() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path reqPath = new Path(UUID.randomUUID().toString());
+
+    final String msg1 = "purple";
+    final String msg2 = "yellow";
+    int expectedFileLength = msg1.length() * 2;
+
+    byte[] readBuffer = new byte[1024];
+
+    // create file with content "purplepurple"
+    try (FSDataOutputStream stream = fs.create(reqPath)) {
+      stream.writeBytes(msg1);
+      stream.hflush();
+      stream.writeBytes(msg1);
+    }
+
+    // open file and verify content is "purplepurple"
+    try (FSDataInputStream stream = fs.open(reqPath)) {
+      int bytesRead = stream.read(readBuffer, 0, readBuffer.length);
+      assertEquals(expectedFileLength, bytesRead);
+      String fileContent = new String(readBuffer, 0, bytesRead, StandardCharsets.UTF_8);
+      assertEquals(msg1 + msg1, fileContent);
+    }
+
+    // overwrite file with content "yellowyellow"
+    try (FSDataOutputStream stream = fs.create(reqPath)) {
+      stream.writeBytes(msg2);
+      stream.hflush();
+      stream.writeBytes(msg2);
+    }
+
+    // open file and verify content is "yellowyellow"
+    try (FSDataInputStream stream = fs.open(reqPath)) {
+      int bytesRead = stream.read(readBuffer, 0, readBuffer.length);
+      assertEquals(expectedFileLength, bytesRead);
+      String fileContent = new String(readBuffer, 0, bytesRead, StandardCharsets.UTF_8);
+      assertEquals(msg2 + msg2, fileContent);
+    }
+
+    // append to file so final content is "yellowyellowpurplepurple"
+    try (FSDataOutputStream stream = fs.append(reqPath)) {
+      stream.writeBytes(msg1);
+      stream.hflush();
+      stream.writeBytes(msg1);
+    }
+
+    // open file and verify content is "yellowyellowpurplepurple"
+    try (FSDataInputStream stream = fs.open(reqPath)) {
+      int bytesRead = stream.read(readBuffer, 0, readBuffer.length);
+      assertEquals(2 * expectedFileLength, bytesRead);
+      String fileContent = new String(readBuffer, 0, bytesRead, StandardCharsets.UTF_8);
+      assertEquals(msg2 + msg2 + msg1 + msg1, fileContent);
+    }
+  }
+
+  @Test
+  // Test rename file and rename folder
+  public void testRename() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path sourceDir = new Path(UUID.randomUUID().toString());
+    Path sourcePath = new Path(sourceDir, UUID.randomUUID().toString());
+    Path destinationPath = new Path(sourceDir, UUID.randomUUID().toString());
+    Path destinationDir = new Path(UUID.randomUUID().toString());
+
+    // create file with content "hello"
+    try (FSDataOutputStream stream = fs.create(sourcePath)) {
+      stream.writeBytes("hello");
+    }
+
+    assertFalse(fs.exists(destinationPath));
+    fs.rename(sourcePath, destinationPath);
+    assertFalse(fs.exists(sourcePath));
+    assertTrue(fs.exists(destinationPath));
+
+    assertFalse(fs.exists(destinationDir));
+    fs.rename(sourceDir, destinationDir);
+    assertFalse(fs.exists(sourceDir));
+    assertTrue(fs.exists(destinationDir));
+  }
+
+  @Test
+  // Test delete file and delete folder
+  public void testDelete() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path dirPath = new Path(UUID.randomUUID().toString());
+    Path filePath = new Path(dirPath, UUID.randomUUID().toString());
+
+    // create file with content "hello"
+    try (FSDataOutputStream stream = fs.create(filePath)) {
+      stream.writeBytes("hello");
+    }
+
+    assertTrue(fs.exists(filePath));
+    fs.delete(filePath, false);
+    assertFalse(fs.exists(filePath));
+
+    assertTrue(fs.exists(dirPath));
+    fs.delete(dirPath, false);
+    assertFalse(fs.exists(dirPath));
+  }
+
+  @Test
+  // Test delete folder recursive
+  public void testDeleteRecursive() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path dirPath = new Path(UUID.randomUUID().toString());
+    Path filePath = new Path(dirPath, UUID.randomUUID().toString());
+
+    // create file with content "hello"
+    try (FSDataOutputStream stream = fs.create(filePath)) {
+      stream.writeBytes("hello");
+    }
+
+    assertTrue(fs.exists(dirPath));
+    assertTrue(fs.exists(filePath));
+    fs.delete(dirPath, true);
+    assertFalse(fs.exists(filePath));
+    assertFalse(fs.exists(dirPath));
+  }
+
+  @Test
+  // Test list on file, directory and root path
+  public void testList() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path dirPath = new Path(UUID.randomUUID().toString());
+    Path filePath = new Path(dirPath, UUID.randomUUID().toString());
+
+    fs.mkdirs(dirPath);
+
+    // create file with content "hello"
+    try (FSDataOutputStream stream = fs.create(filePath)) {
+      stream.writeBytes("hello");
+    }
+
+    fs.listStatus(filePath);
+    fs.listStatus(dirPath);
+    fs.listStatus(new Path("/"));
+  }
+
+  @Test
+  // Test filesystem operations setAcl, getAclStatus, removeAcl
+  // setPermissions and getFileStatus
+  public void testAcl() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path reqPath = new Path(UUID.randomUUID().toString());
+
+    fs.create(reqPath).close();
+
+    fs.setAcl(reqPath, Arrays
+        .asList(aclEntry(ACCESS, GROUP, TEST_GROUP, FsAction.ALL)));
+
+    AclStatus acl = fs.getAclStatus(reqPath);
+    assertEquals(MockDelegationSASTokenProvider.TEST_OWNER, acl.getOwner());
+    assertEquals("[group::r--, group:" + TEST_GROUP + ":rwx]", acl.getEntries().toString());
+
+    fs.removeAcl(reqPath);
+    acl = fs.getAclStatus(reqPath);
+    assertEquals("[]", acl.getEntries().toString());
+
+    fs.setPermission(reqPath,
+        new FsPermission(FsAction.ALL, FsAction.NONE, FsAction.NONE));
+
+    FileStatus status = fs.getFileStatus(reqPath);
+    assertEquals("rwx------", status.getPermission().toString());
+
+    acl = fs.getAclStatus(reqPath);
+    assertEquals("rwx------", acl.getPermission().toString());
+  }
+
+  @Test
+  // Test getFileStatus and getAclStatus operations on root path
+  public void testRootPath() throws Exception {
+    final AzureBlobFileSystem fs = getFileSystem();
+    Path rootPath = new Path(AbfsHttpConstants.ROOT_PATH);
+
+    FileStatus status = fs.getFileStatus(rootPath);
+    assertEquals("rwxr-x---", status.getPermission().toString());
+    assertTrue(status.isDirectory());
+
+    AclStatus acl = fs.getAclStatus(rootPath);
+    assertEquals("rwxr-x---", acl.getPermission().toString());
+
+    List<AclEntry> aclSpec = new ArrayList<>();
+    int count = 0;
+    for (AclEntry entry: acl.getEntries()) {
+      aclSpec.add(entry);
+       if (entry.getScope() == AclEntryScope.DEFAULT) {
+         count++;
+       }
+    }
+    assertEquals(0, count);
+
+    aclSpec.add(aclEntry(DEFAULT, USER, "cd548981-afec-4ab9-9d39-f6f2add2fd9b", FsAction.EXECUTE));
+
+    fs.modifyAclEntries(rootPath, aclSpec);
+
+    acl = fs.getAclStatus(rootPath);
+
+    count = 0;
+    for (AclEntry entry: acl.getEntries()) {
+      aclSpec.add(entry);
+      if (entry.getScope() == AclEntryScope.DEFAULT) {
+        count++;
+      }
+    }
+    assertEquals(5, count);
+
+    fs.removeDefaultAcl(rootPath);
+
+    acl = fs.getAclStatus(rootPath);
+
+    count = 0;
+    for (AclEntry entry: acl.getEntries()) {
+      aclSpec.add(entry);
+      if (entry.getScope() == AclEntryScope.DEFAULT) {
+        count++;
+      }
+    }
+    assertEquals(0, count);
+  }
+}

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/constants/TestConfigurationKeys.java

@@ -45,6 +45,14 @@ public final class TestConfigurationKeys {
   public static final String MOCK_SASTOKENPROVIDER_FAIL_INIT = "mock.sastokenprovider.fail.init";
   public static final String MOCK_SASTOKENPROVIDER_RETURN_EMPTY_SAS_TOKEN = "mock.sastokenprovider.return.empty.sasToken";
 
+  public static final String FS_AZURE_TEST_APP_SERVICE_PRINCIPAL_TENANT_ID = "fs.azure.test.app.service.principal.tenant.id";
+
+  public static final String FS_AZURE_TEST_APP_SERVICE_PRINCIPAL_OBJECT_ID = "fs.azure.test.app.service.principal.object.id";
+
+  public static final String FS_AZURE_TEST_APP_ID = "fs.azure.test.app.id";
+
+  public static final String FS_AZURE_TEST_APP_SECRET = "fs.azure.test.app.secret";
+
   public static final String TEST_CONFIGURATION_FILE_NAME = "azure-test.xml";
   public static final String TEST_CONTAINER_PREFIX = "abfs-testcontainer-";
   public static final int TEST_TIMEOUT = 15 * 60 * 1000;

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/extensions/MockDelegationSASTokenProvider.java

@@ -0,0 +1,142 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.azurebfs.extensions;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.azurebfs.constants.AbfsHttpConstants;
+import org.apache.hadoop.fs.azurebfs.constants.TestConfigurationKeys;
+import org.apache.hadoop.fs.azurebfs.constants.HttpHeaderConfigurations;
+import org.apache.hadoop.fs.azurebfs.contracts.exceptions.InvalidUriException;
+import org.apache.hadoop.fs.azurebfs.oauth2.ClientCredsTokenProvider;
+import org.apache.hadoop.fs.azurebfs.services.AbfsHttpHeader;
+import org.apache.hadoop.fs.azurebfs.services.AbfsHttpOperation;
+import org.apache.hadoop.fs.azurebfs.utils.Base64;
+import org.apache.hadoop.fs.azurebfs.utils.DelegationSASGenerator;
+import org.apache.hadoop.fs.azurebfs.utils.SASGenerator;
+import org.apache.hadoop.security.AccessControlException;
+
+/**
+ * A mock SAS token provider implementation
+ */
+public class MockDelegationSASTokenProvider implements SASTokenProvider {
+
+  private DelegationSASGenerator generator;
+
+  public static final String TEST_OWNER = "325f1619-4205-432f-9fce-3fd594325ce5";
+  public static final String CORRELATION_ID = "66ff4ffc-ff17-417e-a2a9-45db8c5b0b5c";
+
+  @Override
+  public void initialize(Configuration configuration, String accountName) throws IOException {
+    String appID = configuration.get(TestConfigurationKeys.FS_AZURE_TEST_APP_ID);
+    String appSecret = configuration.get(TestConfigurationKeys.FS_AZURE_TEST_APP_SECRET);
+    String sktid = configuration.get(TestConfigurationKeys.FS_AZURE_TEST_APP_SERVICE_PRINCIPAL_TENANT_ID);
+    String skoid = configuration.get(TestConfigurationKeys.FS_AZURE_TEST_APP_SERVICE_PRINCIPAL_OBJECT_ID);
+    String skt = SASGenerator.ISO_8601_FORMATTER.format(Instant.now().minusSeconds(SASGenerator.FIVE_MINUTES));
+    String ske = SASGenerator.ISO_8601_FORMATTER.format(Instant.now().plusSeconds(SASGenerator.ONE_DAY));
+    String skv = SASGenerator.AuthenticationVersion.Dec19.toString();
+
+    byte[] key = getUserDelegationKey(accountName, appID, appSecret, sktid, skt, ske, skv);
+
+    generator = new DelegationSASGenerator(key, skoid, sktid, skt, ske, skv);
+  }
+
+  // Invokes the AAD v2.0 authentication endpoint with a client credentials grant to get an
+  // access token.  See https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow.
+  private String getAuthorizationHeader(String accountName, String appID, String appSecret, String sktid) throws IOException {
+    String authEndPoint = String.format("https://login.microsoftonline.com/%s/oauth2/v2.0/token", sktid);
+    ClientCredsTokenProvider provider = new ClientCredsTokenProvider(authEndPoint, appID, appSecret);
+    return "Bearer " + provider.getToken().getAccessToken();
+  }
+
+  private byte[] getUserDelegationKey(String accountName, String appID, String appSecret,
+      String sktid, String skt, String ske, String skv) throws IOException {
+
+    String method = "POST";
+    String account = accountName.substring(0, accountName.indexOf(AbfsHttpConstants.DOT));
+
+    final StringBuilder sb = new StringBuilder(128);
+    sb.append("https://");
+    sb.append(account);
+    sb.append(".blob.core.windows.net/?restype=service&comp=userdelegationkey");
+
+    URL url;
+    try {
+      url = new URL(sb.toString());
+    } catch (MalformedURLException ex) {
+      throw new InvalidUriException(sb.toString());
+    }
+
+    List<AbfsHttpHeader> requestHeaders = new ArrayList<AbfsHttpHeader>();
+    requestHeaders.add(new AbfsHttpHeader(HttpHeaderConfigurations.X_MS_VERSION, skv));
+    requestHeaders.add(new AbfsHttpHeader(HttpHeaderConfigurations.CONTENT_TYPE, "application/x-www-form-urlencoded"));
+    requestHeaders.add(new AbfsHttpHeader(HttpHeaderConfigurations.AUTHORIZATION, getAuthorizationHeader(account, appID, appSecret, sktid)));
+
+    final StringBuilder requestBody = new StringBuilder(512);
+    requestBody.append("<?xml version=\"1.0\" encoding=\"utf-8\"?><KeyInfo><Start>");
+    requestBody.append(skt);
+    requestBody.append("</Start><Expiry>");
+    requestBody.append(ske);
+    requestBody.append("</Expiry></KeyInfo>");
+
+    AbfsHttpOperation op = new AbfsHttpOperation(url, method, requestHeaders);
+
+    byte[] requestBuffer = requestBody.toString().getBytes(StandardCharsets.UTF_8.toString());
+    op.sendRequest(requestBuffer, 0, requestBuffer.length);
+
+    byte[] responseBuffer = new byte[4 * 1024];
+    op.processResponse(responseBuffer, 0, responseBuffer.length);
+
+    String responseBody = new String(responseBuffer, 0, (int) op.getBytesReceived(), StandardCharsets.UTF_8);
+    int beginIndex = responseBody.indexOf("<Value>") + "<Value>".length();
+    int endIndex = responseBody.indexOf("</Value>");
+    String value = responseBody.substring(beginIndex, endIndex);
+    return Base64.decode(value);
+  }
+
+  /**
+   * Invokes the authorizer to obtain a SAS token.
+   *
+   * @param accountName the name of the storage account.
+   * @param fileSystem the name of the fileSystem.
+   * @param path the file or directory path.
+   * @param operation the operation to be performed on the path.
+   * @return a SAS token to perform the request operation.
+   * @throws IOException if there is a network error.
+   * @throws AccessControlException if access is denied.
+   */
+  @Override
+  public String getSASToken(String accountName, String fileSystem, String path,
+                     String operation) throws IOException, AccessControlException {
+    // The user for these tests is always TEST_OWNER.  The check access operation
+    // requires suoid to check permissions for the user and will throw if the
+    // user does not have access and otherwise succeed.
+    String saoid = (operation == SASTokenProvider.CHECK_ACCESS_OPERATION) ? null : TEST_OWNER;
+    String suoid = (operation == SASTokenProvider.CHECK_ACCESS_OPERATION) ? TEST_OWNER : null;
+    return generator.getDelegationSAS(accountName, fileSystem, path, operation,
+        saoid, suoid, CORRELATION_ID);
+  }
+}

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/extensions/MockSASTokenProvider.java

@@ -25,7 +25,7 @@
 
 import org.apache.hadoop.fs.azurebfs.AbfsConfiguration;
 import org.apache.hadoop.fs.azurebfs.utils.Base64;
-import org.apache.hadoop.fs.azurebfs.utils.SASGenerator;
+import org.apache.hadoop.fs.azurebfs.utils.ServiceSASGenerator;
 
 /**
  * A mock SAS token provider implementation
@@ -33,7 +33,7 @@
 public class MockSASTokenProvider implements SASTokenProvider {
 
   private byte[] accountKey;
-  private SASGenerator generator;
+  private ServiceSASGenerator generator;
   private boolean skipAuthorizationForTestSetup = false;
 
   // For testing we use a container SAS for all operations.
@@ -49,7 +49,7 @@ public void initialize(Configuration configuration, String accountName) throws I
     } catch (Exception ex) {
       throw new IOException(ex);
     }
-    generator = new SASGenerator(accountKey);
+    generator = new ServiceSASGenerator(accountKey);
   }
 
   /**

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/utils/DelegationSASGenerator.java

@@ -0,0 +1,194 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.azurebfs.utils;
+
+import java.time.Instant;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.hadoop.fs.azurebfs.extensions.SASTokenProvider;
+import org.apache.hadoop.fs.azurebfs.services.AbfsUriQueryBuilder;
+
+
+/**
+ * Test Delegation SAS generator.
+ */
+public class DelegationSASGenerator extends SASGenerator {
+  private String skoid;
+  private String sktid;
+  private String skt;
+  private String ske;
+  private final String sks = "b";
+  private String skv;
+
+  public DelegationSASGenerator(byte[] userDelegationKey, String skoid, String sktid, String skt, String ske, String skv) {
+    super(userDelegationKey);
+    this.skoid = skoid;
+    this.sktid = sktid;
+    this.skt = skt;
+    this.ske = ske;
+    this.skv = skv;
+  }
+
+  public String getDelegationSAS(String accountName, String containerName, String path, String operation,
+                                 String saoid, String suoid, String scid) {
+
+    final String sv = AuthenticationVersion.Dec19.toString();
+    final String st = ISO_8601_FORMATTER.format(Instant.now().minusSeconds(FIVE_MINUTES));
+    final String se = ISO_8601_FORMATTER.format(Instant.now().plusSeconds(ONE_DAY));
+    String sr = "b";
+    String sdd = null;
+    String sp = null;
+
+    switch (operation) {
+      case SASTokenProvider.CHECK_ACCESS_OPERATION:
+        sp = "e";
+        break;
+      case SASTokenProvider.WRITE_OPERATION:
+      case SASTokenProvider.CREATE_FILE_OPERATION:
+      case SASTokenProvider.CREATE_DIRECTORY_OPERATION:
+        sp = "w";
+        break;
+      case SASTokenProvider.DELETE_OPERATION:
+        sp = "d";
+        break;
+      case SASTokenProvider.DELETE_RECURSIVE_OPERATION:
+        sp = "d";
+        sr = "d";
+        sdd = Integer.toString(StringUtils.countMatches(path, "/"));
+        break;
+      case SASTokenProvider.GET_ACL_OPERATION:
+      case SASTokenProvider.GET_STATUS_OPERATION:
+        sp = "e";
+        break;
+      case SASTokenProvider.LIST_OPERATION:
+        sp = "l";
+        break;
+      case SASTokenProvider.READ_OPERATION:
+        sp = "r";
+        break;
+      case SASTokenProvider.RENAME_DESTINATION_OPERATION:
+      case SASTokenProvider.RENAME_SOURCE_OPERATION:
+        sp = "m";
+        break;
+      case SASTokenProvider.SET_ACL_OPERATION:
+        sp = "p";
+        break;
+      case SASTokenProvider.SET_OWNER_OPERATION:
+        sp = "o";
+        break;
+      case SASTokenProvider.SET_PERMISSION_OPERATION:
+        sp = "p";
+        break;
+      default:
+        throw new IllegalArgumentException(operation);
+    }
+
+    String signature = computeSignatureForSAS(sp, st, se, sv, sr, accountName, containerName,
+        path, saoid, suoid, scid);
+
+    AbfsUriQueryBuilder qb = new AbfsUriQueryBuilder();
+    qb.addQuery("skoid", skoid);
+    qb.addQuery("sktid", sktid);
+    qb.addQuery("skt", skt);
+    qb.addQuery("ske", ske);
+    qb.addQuery("sks", sks);
+    qb.addQuery("skv", skv);
+    if (saoid != null) {
+      qb.addQuery("saoid", saoid);
+    }
+    if (suoid != null) {
+      qb.addQuery("suoid", suoid);
+    }
+    if (scid != null) {
+      qb.addQuery("scid", scid);
+    }
+    qb.addQuery("sp", sp);
+    qb.addQuery("st", st);
+    qb.addQuery("se", se);
+    qb.addQuery("sv", sv);
+    qb.addQuery("sr", sr);
+    if (sdd != null) {
+      qb.addQuery("sdd", sdd);
+    }
+    qb.addQuery("sig", signature);
+    return qb.toString().substring(1);
+  }
+
+  private String computeSignatureForSAS(String sp, String st, String se, String sv,
+      String sr, String accountName, String containerName,
+      String path, String saoid, String suoid, String scid) {
+
+    StringBuilder sb = new StringBuilder();
+    sb.append(sp);
+    sb.append("\n");
+    sb.append(st);
+    sb.append("\n");
+    sb.append(se);
+    sb.append("\n");
+    // canonicalized resource
+    sb.append("/blob/");
+    sb.append(accountName);
+    sb.append("/");
+    sb.append(containerName);
+    if (path != null && sr != "c") {
+      sb.append(path);
+    }
+    sb.append("\n");
+    sb.append(skoid);
+    sb.append("\n");
+    sb.append(sktid);
+    sb.append("\n");
+    sb.append(skt);
+    sb.append("\n");
+    sb.append(ske);
+    sb.append("\n");
+    sb.append(sks);
+    sb.append("\n");
+    sb.append(skv);
+    sb.append("\n");
+    if (saoid != null) {
+      sb.append(saoid);
+    }
+    sb.append("\n");
+    if (suoid != null) {
+      sb.append(suoid);
+    }
+    sb.append("\n");
+    if (scid != null) {
+      sb.append(scid);
+    }
+    sb.append("\n");
+
+    sb.append("\n"); // sip
+    sb.append("\n"); // spr
+    sb.append(sv);
+    sb.append("\n");
+    sb.append(sr);
+    sb.append("\n");
+    sb.append("\n"); // - For optional : rscc - ResponseCacheControl
+    sb.append("\n"); // - For optional : rscd - ResponseContentDisposition
+    sb.append("\n"); // - For optional : rsce - ResponseContentEncoding
+    sb.append("\n"); // - For optional : rscl - ResponseContentLanguage
+    sb.append("\n"); // - For optional : rsct - ResponseContentType
+
+    String stringToSign = sb.toString();
+    LOG.debug("Delegation SAS stringToSign: " + stringToSign.replace("\n", "."));
+    return computeHmac256(stringToSign);
+  }
+}

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/utils/SASGenerator.java

@@ -19,104 +19,74 @@
 package org.apache.hadoop.fs.azurebfs.utils;
 
 import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.time.format.DateTimeFormatter;
-import java.time.Instant;
 import java.time.ZoneId;
 import java.util.Locale;
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
 
-import org.apache.hadoop.fs.azurebfs.constants.AbfsHttpConstants;
+import org.slf4j.Logger;
-import org.apache.hadoop.fs.azurebfs.services.AbfsUriQueryBuilder;
+import org.slf4j.LoggerFactory;
-
 /**
- * Test container SAS generator.
+ * Test SAS generator.
  */
-public class SASGenerator {
+public abstract class SASGenerator {
 
-  private static final String HMAC_SHA256 = "HmacSHA256";
+  public enum AuthenticationVersion {
-  private static final int TOKEN_START_PERIOD_IN_SECONDS = 5 * 60;
+    Nov18("2018-11-09"),
-  private static final int TOKEN_EXPIRY_PERIOD_IN_SECONDS = 24 * 60 * 60;
+    Dec19("2019-12-12");
-  public static final DateTimeFormatter ISO_8601_UTC_DATE_FORMATTER =
+
+    private final String ver;
+
+    AuthenticationVersion(String version) {
+      this.ver = version;
+    }
+
+    @Override
+    public String toString() {
+      return ver;
+    }
+  }
+
+  protected static final Logger LOG = LoggerFactory.getLogger(SASGenerator.class);
+  public static final int FIVE_MINUTES = 5 * 60;
+  public static final int ONE_DAY = 24 * 60 * 60;
+  public static final DateTimeFormatter ISO_8601_FORMATTER =
       DateTimeFormatter
           .ofPattern("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ROOT)
           .withZone(ZoneId.of("UTC"));
+
   private Mac hmacSha256;
   private byte[] key;
 
-  public SASGenerator(byte[] key) {
+  // hide default constructor
+  private SASGenerator() {
+  }
+
+  /**
+   * Called by subclasses to initialize the cryptographic SHA-256 HMAC provider.
+   * @param key - a 256-bit secret key
+   */
+  protected SASGenerator(byte[] key) {
     this.key = key;
     initializeMac();
   }
 
-  public String getContainerSASWithFullControl(String accountName, String containerName) {
-    String sp = "rcwdl";
-    String sv = "2018-11-09";
-    String sr = "c";
-    String st = ISO_8601_UTC_DATE_FORMATTER.format(Instant.now().minusSeconds(TOKEN_START_PERIOD_IN_SECONDS));
-    String se =
-        ISO_8601_UTC_DATE_FORMATTER.format(Instant.now().plusSeconds(TOKEN_EXPIRY_PERIOD_IN_SECONDS));
-
-    String signature = computeSignatureForSAS(sp, st, se, sv, "c",
-        accountName, containerName);
-
-    AbfsUriQueryBuilder qb = new AbfsUriQueryBuilder();
-    qb.addQuery("sp", sp);
-    qb.addQuery("st", st);
-    qb.addQuery("se", se);
-    qb.addQuery("sv", sv);
-    qb.addQuery("sr", sr);
-    qb.addQuery("sig", signature);
-    return qb.toString().substring(1);
-  }
-
-  private String computeSignatureForSAS(String sp, String st,
-      String se, String sv, String sr, String accountName, String containerName) {
-
-    StringBuilder sb = new StringBuilder();
-    sb.append(sp);
-    sb.append("\n");
-    sb.append(st);
-    sb.append("\n");
-    sb.append(se);
-    sb.append("\n");
-    // canonicalized resource
-    sb.append("/blob/");
-    sb.append(accountName);
-    sb.append("/");
-    sb.append(containerName);
-    sb.append("\n");
-    sb.append("\n"); // si
-    sb.append("\n"); // sip
-    sb.append("\n"); // spr
-    sb.append(sv);
-    sb.append("\n");
-    sb.append(sr);
-    sb.append("\n");
-    sb.append("\n"); // - For optional : rscc - ResponseCacheControl
-    sb.append("\n"); // - For optional : rscd - ResponseContentDisposition
-    sb.append("\n"); // - For optional : rsce - ResponseContentEncoding
-    sb.append("\n"); // - For optional : rscl - ResponseContentLanguage
-    sb.append("\n"); // - For optional : rsct - ResponseContentType
-
-    String stringToSign = sb.toString();
-    return computeHmac256(stringToSign);
-  }
-
   private void initializeMac() {
     // Initializes the HMAC-SHA256 Mac and SecretKey.
     try {
-      hmacSha256 = Mac.getInstance(HMAC_SHA256);
+      hmacSha256 = Mac.getInstance("HmacSHA256");
-      hmacSha256.init(new SecretKeySpec(key, HMAC_SHA256));
+      hmacSha256.init(new SecretKeySpec(key, "HmacSHA256"));
     } catch (final Exception e) {
       throw new IllegalArgumentException(e);
     }
   }
 
-  private String computeHmac256(final String stringToSign) {
+  protected String computeHmac256(final String stringToSign) {
     byte[] utf8Bytes;
     try {
-      utf8Bytes = stringToSign.getBytes(AbfsHttpConstants.UTF_8);
+      utf8Bytes = stringToSign.getBytes(StandardCharsets.UTF_8.toString());
     } catch (final UnsupportedEncodingException e) {
       throw new IllegalArgumentException(e);
     }
@@ -126,4 +96,4 @@ private String computeHmac256(final String stringToSign) {
     }
     return Base64.encode(hmac);
   }
-}
+}

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/utils/ServiceSASGenerator.java

@@ -0,0 +1,96 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.azurebfs.utils;
+
+import java.time.Instant;
+
+import org.apache.hadoop.fs.azurebfs.services.AbfsUriQueryBuilder;
+
+/**
+ * Test Service SAS generator.
+ */
+public class ServiceSASGenerator extends SASGenerator {
+
+  /**
+   * Creates a SAS Generator for Service SAS
+   * (https://docs.microsoft.com/en-us/rest/api/storageservices/create-service-sas).
+   * @param accountKey - the storage account key
+   */
+  public ServiceSASGenerator(byte[] accountKey) {
+    super(accountKey);
+  }
+
+  public String getContainerSASWithFullControl(String accountName, String containerName) {
+    String sp = "rcwdl";
+    String sv = AuthenticationVersion.Nov18.toString();
+    String sr = "c";
+    String st = ISO_8601_FORMATTER.format(Instant.now().minusSeconds(FIVE_MINUTES));
+    String se = ISO_8601_FORMATTER.format(Instant.now().plusSeconds(ONE_DAY));
+
+    String signature = computeSignatureForSAS(sp, st, se, sv, "c",
+        accountName, containerName, null);
+
+    AbfsUriQueryBuilder qb = new AbfsUriQueryBuilder();
+    qb.addQuery("sp", sp);
+    qb.addQuery("st", st);
+    qb.addQuery("se", se);
+    qb.addQuery("sv", sv);
+    qb.addQuery("sr", sr);
+    qb.addQuery("sig", signature);
+    return qb.toString().substring(1);
+  }
+
+  private String computeSignatureForSAS(String sp, String st, String se, String sv,
+      String sr, String accountName, String containerName, String path) {
+
+    StringBuilder sb = new StringBuilder();
+    sb.append(sp);
+    sb.append("\n");
+    sb.append(st);
+    sb.append("\n");
+    sb.append(se);
+    sb.append("\n");
+    // canonicalized resource
+    sb.append("/blob/");
+    sb.append(accountName);
+    sb.append("/");
+    sb.append(containerName);
+    if (path != null && sr != "c") {
+      //sb.append("/");
+      sb.append(path);
+    }
+    sb.append("\n");
+    sb.append("\n"); // si
+    sb.append("\n"); // sip
+    sb.append("\n"); // spr
+    sb.append(sv);
+    sb.append("\n");
+    sb.append(sr);
+    sb.append("\n");
+    sb.append("\n"); // - For optional : rscc - ResponseCacheControl
+    sb.append("\n"); // - For optional : rscd - ResponseContentDisposition
+    sb.append("\n"); // - For optional : rsce - ResponseContentEncoding
+    sb.append("\n"); // - For optional : rscl - ResponseContentLanguage
+    sb.append("\n"); // - For optional : rsct - ResponseContentType
+
+    String stringToSign = sb.toString();
+    LOG.debug("Service SAS stringToSign: " + stringToSign.replace("\n", "."));
+    return computeHmac256(stringToSign);
+  }
+}

hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/utils/TestCachedSASToken.java

@@ -0,0 +1,162 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.fs.azurebfs.utils;
+
+import java.io.IOException;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS;
+import static java.time.temporal.ChronoUnit.SECONDS;
+
+/**
+ * Test CachedSASToken.
+ */
+public final class TestCachedSASToken {
+
+  @Test
+  public void testUpdateAndGet() throws IOException {
+    CachedSASToken cachedSasToken = new CachedSASToken();
+
+    String se1 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS * 2,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+    String token1 = "se=" + se1;
+
+    // set first time and ensure reference equality
+    cachedSasToken.update(token1);
+    String cachedToken = cachedSasToken.get();
+    Assert.assertTrue(token1 == cachedToken);
+
+    // update with same token and ensure reference equality
+    cachedSasToken.update(token1);
+    cachedToken = cachedSasToken.get();
+    Assert.assertTrue(token1 == cachedToken);
+
+    // renew and ensure reference equality
+    String se2 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS * 2,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+    String token2 = "se=" + se2;
+    cachedSasToken.update(token2);
+    cachedToken = cachedSasToken.get();
+    Assert.assertTrue(token2 == cachedToken);
+
+    // renew and ensure reference equality with ske
+    String se3 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS * 4,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+
+    String ske3 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS * 2,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+    String token3 = "se=" + se3 + "&ske=" + ske3;
+    cachedSasToken.update(token3);
+    cachedToken = cachedSasToken.get();
+    Assert.assertTrue(token3 == cachedToken);
+  }
+
+  @Test
+  public void testGetExpiration() throws IOException {
+    CachedSASToken cachedSasToken = new CachedSASToken();
+
+    String se = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS - 1,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+    OffsetDateTime seDate = OffsetDateTime.parse(se, DateTimeFormatter.ISO_DATE_TIME);
+    String token = "se=" + se;
+
+    // By-pass the normal validation provided by update method
+    // by callng set with expired SAS, then ensure the get
+    // method returns null (auto expiration as next REST operation will use
+    // SASTokenProvider to get a new SAS).
+    cachedSasToken.setForTesting(token, seDate);
+    String cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+  }
+
+  @Test
+  public void testUpdateAndGetWithExpiredToken() throws IOException {
+    CachedSASToken cachedSasToken = new CachedSASToken();
+
+    String se1 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS - 1,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+    String token1 = "se=" + se1;
+
+    // set expired token and ensure not cached
+    cachedSasToken.update(token1);
+    String cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+
+    String se2 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS * 2,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+
+    String ske2 = OffsetDateTime.now(ZoneOffset.UTC).plus(
+        DEFAULT_SAS_TOKEN_RENEW_PERIOD_FOR_STREAMS_IN_SECONDS - 1,
+        SECONDS).format(DateTimeFormatter.ISO_DATE_TIME);
+    String token2 = "se=" + se2 + "&ske=" + ske2;
+
+    // set with expired ske and ensure not cached
+    cachedSasToken.update(token2);
+    cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+
+  }
+
+  @Test
+  public void testUpdateAndGetWithInvalidToken() throws IOException {
+    CachedSASToken cachedSasToken = new CachedSASToken();
+
+    // set and ensure reference that it is not cached
+    String token1 = "se=";
+    cachedSasToken.update(token1);
+    String cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+
+    // set and ensure reference that it is not cached
+    String token2 = "se=xyz";
+    cachedSasToken.update(token2);
+    cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+
+    // set and ensure reference that it is not cached
+    String token3 = "se=2100-01-01T00:00:00Z&ske=";
+    cachedSasToken.update(token3);
+    cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+
+    // set and ensure reference that it is not cached
+    String token4 = "se=2100-01-01T00:00:00Z&ske=xyz&";
+    cachedSasToken.update(token4);
+    cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+
+    // set and ensure reference that it is not cached
+    String token5 = "se=abc&ske=xyz&";
+    cachedSasToken.update(token5);
+    cachedToken = cachedSasToken.get();
+    Assert.assertNull(cachedToken);
+  }
+}