diff --git a/Storage/src/Bucket.php b/Storage/src/Bucket.php
index bf1c44534ca3..887cffd4f84d 100644
--- a/Storage/src/Bucket.php
+++ b/Storage/src/Bucket.php
@@ -247,6 +247,11 @@ public function exists(array $options = [])
      *           validation hash will be sent. Choose either `md5` or `crc32` to
      *           force a hash method regardless of performance implications.
      *           **Defaults to** `true`.
+     *     @type string $crc32c The base64 encoded CRC32C checksum of the object
+     *           data. If provided, this hash will be used for server-side
+     *           validation.
+     *     @type string $md5 The base64 encoded MD5 hash of the object data. If
+     *           provided, this hash will be used for server-side validation.
      *     @type int $chunkSize If provided the upload will be done in chunks.
      *           The size must be in multiples of 262144 bytes. With chunking
      *           you have increased reliability at the risk of higher overhead.
@@ -379,6 +384,11 @@ public function upload($data, array $options = [])
      *           validation hash will be sent. Choose either `md5` or `crc32` to
      *           force a hash method regardless of performance implications.
      *           **Defaults to** `true`.
+     *     @type string $crc32c The base64 encoded CRC32C checksum of the object
+     *           data. If provided, this hash will be used for server-side
+     *           validation.
+     *     @type string $md5 The base64 encoded MD5 hash of the object data. If
+     *           provided, this hash will be used for server-side validation.
      *     @type string $predefinedAcl Predefined ACL to apply to the object.
      *           Acceptable values include, `"authenticatedRead"`,
      *           `"bucketOwnerFullControl"`, `"bucketOwnerRead"`, `"private"`,
diff --git a/Storage/src/Connection/Rest.php b/Storage/src/Connection/Rest.php
index b5049b3c2908..b240f580d941 100644
--- a/Storage/src/Connection/Rest.php
+++ b/Storage/src/Connection/Rest.php
@@ -499,6 +499,36 @@ private function resolveUploadOptions(array $args)
             $args['name'] = basename($args['data']->getMetadata('uri'));
         }
 
+        if (isset($args['crc32c'])) {
+            $args['metadata']['crc32c'] = $args['crc32c'];
+            $userCrc32c = $args['crc32c'];
+            unset($args['crc32c']);
+        }
+        if (isset($args['md5'])) {
+            $args['metadata']['md5Hash'] = $args['md5'];
+            $userMd5 = $args['md5'];
+            unset($args['md5']);
+        }
+        if (isset($userCrc32c) || isset($userMd5)) {
+            // Disable auto-validation to prevent redundant calculations
+            $args['validate'] = false;
+
+            $xGoogHash = [];
+            if (isset($userMd5)) {
+                $xGoogHash[] = 'md5=' . $userMd5;
+            }
+            if (isset($userCrc32c)) {
+                $xGoogHash[] = 'crc32c=' . $userCrc32c;
+            }
+
+            // Append to existing X-Goog-Hash if present
+            if (isset($args['headers']['X-Goog-Hash'])) {
+                $args['headers']['X-Goog-Hash'] .= ',' . implode(',', $xGoogHash);
+            } else {
+                $args['headers']['X-Goog-Hash'] = implode(',', $xGoogHash);
+            }
+        }
+
         $validate = $this->chooseValidationMethod($args);
         $xGoogHashHeader = '';
         if ($validate !== false) {
diff --git a/Storage/tests/System/UploadObjectsTest.php b/Storage/tests/System/UploadObjectsTest.php
index 247724424ce1..745a665ad625 100644
--- a/Storage/tests/System/UploadObjectsTest.php
+++ b/Storage/tests/System/UploadObjectsTest.php
@@ -142,4 +142,57 @@ public function testCrc32cChecksumFails()
             ]
         ]);
     }
+
+    public function testCrc32cChecksumFailsWithTopLevelOption()
+    {
+        $this->expectException(BadRequestException::class);
+
+        $data = 'somedata';
+        $badChecksum = base64_encode(hash('crc32c', 'bad-data', true));
+
+        self::$bucket->upload($data, [
+            'name' => uniqid(self::TESTING_PREFIX),
+            'crc32c' => $badChecksum
+        ]);
+    }
+
+    public function testCrc32cChecksumSucceedsWithTopLevelOption()
+    {
+        $data = 'somedata';
+        $goodChecksum = base64_encode(hash('crc32c', $data, true));
+
+        $object = self::$bucket->upload($data, [
+            'name' => uniqid(self::TESTING_PREFIX),
+            'crc32c' => $goodChecksum
+        ]);
+        $this->assertEquals(strlen($data), $object->info()['size']);
+        $object->delete();
+    }
+
+    public function testMd5ChecksumFailsWithTopLevelOption()
+    {
+        $this->expectException(BadRequestException::class);
+
+        $data = 'somedata';
+        $badChecksum = base64_encode(hash('md5', 'bad-data', true));
+
+        self::$bucket->upload($data, [
+            'name' => uniqid(self::TESTING_PREFIX),
+            'md5' => $badChecksum
+        ]);
+    }
+
+    public function testMd5ChecksumSucceedsWithTopLevelOption()
+    {
+        $data = 'somedata';
+        $goodChecksum = base64_encode(hash('md5', $data, true));
+
+        $object = self::$bucket->upload($data, [
+            'name' => uniqid(self::TESTING_PREFIX),
+            'md5' => $goodChecksum
+        ]);
+
+        $this->assertEquals(strlen($data), $object->info()['size']);
+        $object->delete();
+    }
 }
diff --git a/Storage/tests/Unit/Connection/RestTest.php b/Storage/tests/Unit/Connection/RestTest.php
index 4960da408392..7fc4198ffe5c 100644
--- a/Storage/tests/Unit/Connection/RestTest.php
+++ b/Storage/tests/Unit/Connection/RestTest.php
@@ -581,6 +581,140 @@ function ($args) use (&$actualRequest, $response) {
         $this->assertArrayNotHasKey('crc32c', $metadata);
     }
 
+    public function testInsertObjectWithUserProvidedHashes()
+    {
+        $rest = new Rest();
+        $testData = 'some test data';
+        $testStream = Utils::streamFor($testData);
+        $userCrc32c = 'user-crc';
+        $userMd5 = 'user-md5';
+        $expectedHashHeader = 'md5=' . $userMd5 . ',crc32c=' . $userCrc32c;
+
+        $actualRequest = null;
+        $response = new Response(200, ['Location' => 'http://www.mordor.com'], $this->successBody);
+
+        $this->requestWrapper->send(
+            Argument::type(RequestInterface::class),
+            Argument::type('array')
+        )->will(
+            function ($args) use (&$actualRequest, $response) {
+                $actualRequest = $args[0];
+                return $response;
+            }
+        );
+
+        $rest->setRequestWrapper($this->requestWrapper->reveal());
+
+        $options = [
+            'bucket' => 'my-test-bucket',
+            'name' => 'test-user-hash-file.txt',
+            'data' => $testStream,
+            'crc32c' => $userCrc32c,
+            'md5' => $userMd5,
+            'validate' => true
+        ];
+
+        $uploader = $rest->insertObject($options);
+        $this->assertInstanceOf(MultipartUploader::class, $uploader);
+        $uploader->upload();
+
+        $this->assertNotNull($actualRequest);
+        $this->assertTrue($actualRequest->hasHeader('X-Goog-Hash'));
+        $this->assertEquals([$expectedHashHeader], $actualRequest->getHeader('X-Goog-Hash'));
+
+        list($contentType, $metadata) = $this->getContentTypeAndMetadata($actualRequest);
+        $this->assertEquals($userMd5, $metadata['md5Hash']);
+        $this->assertEquals($userCrc32c, $metadata['crc32c']);
+    }
+
+    public function testInsertObjectWithUserProvidedCrc32cOnly()
+    {
+        $rest = new Rest();
+        $testData = 'some test data';
+        $testStream = Utils::streamFor($testData);
+        $userCrc32c = 'user-crc';
+        $expectedHashHeader = 'crc32c=' . $userCrc32c;
+
+        $actualRequest = null;
+        $response = new Response(200, ['Location' => 'http://www.mordor.com'], $this->successBody);
+
+        $this->requestWrapper->send(
+            Argument::type(RequestInterface::class),
+            Argument::type('array')
+        )->will(
+            function ($args) use (&$actualRequest, $response) {
+                $actualRequest = $args[0];
+                return $response;
+            }
+        );
+
+        $rest->setRequestWrapper($this->requestWrapper->reveal());
+
+        $options = [
+            'bucket' => 'my-test-bucket',
+            'name' => 'test-user-hash-file.txt',
+            'data' => $testStream,
+            'crc32c' => $userCrc32c,
+            'validate' => true
+        ];
+
+        $uploader = $rest->insertObject($options);
+        $this->assertInstanceOf(MultipartUploader::class, $uploader);
+        $uploader->upload();
+
+        $this->assertNotNull($actualRequest);
+        $this->assertTrue($actualRequest->hasHeader('X-Goog-Hash'));
+        $this->assertEquals([$expectedHashHeader], $actualRequest->getHeader('X-Goog-Hash'));
+
+        list($contentType, $metadata) = $this->getContentTypeAndMetadata($actualRequest);
+        $this->assertEquals($userCrc32c, $metadata['crc32c']);
+        $this->assertArrayNotHasKey('md5Hash', $metadata);
+    }
+
+    public function testInsertObjectWithUserProvidedMd5Only()
+    {
+        $rest = new Rest();
+        $testData = 'some test data';
+        $testStream = Utils::streamFor($testData);
+        $userMd5 = 'user-md5';
+        $expectedHashHeader = 'md5=' . $userMd5;
+
+        $actualRequest = null;
+        $response = new Response(200, ['Location' => 'http://www.mordor.com'], $this->successBody);
+
+        $this->requestWrapper->send(
+            Argument::type(RequestInterface::class),
+            Argument::type('array')
+        )->will(
+            function ($args) use (&$actualRequest, $response) {
+                $actualRequest = $args[0];
+                return $response;
+            }
+        );
+
+        $rest->setRequestWrapper($this->requestWrapper->reveal());
+
+        $options = [
+            'bucket' => 'my-test-bucket',
+            'name' => 'test-user-hash-file.txt',
+            'data' => $testStream,
+            'md5' => $userMd5,
+            'validate' => true
+        ];
+
+        $uploader = $rest->insertObject($options);
+        $this->assertInstanceOf(MultipartUploader::class, $uploader);
+        $uploader->upload();
+
+        $this->assertNotNull($actualRequest);
+        $this->assertTrue($actualRequest->hasHeader('X-Goog-Hash'));
+        $this->assertEquals([$expectedHashHeader], $actualRequest->getHeader('X-Goog-Hash'));
+
+        list($contentType, $metadata) = $this->getContentTypeAndMetadata($actualRequest);
+        $this->assertEquals($userMd5, $metadata['md5Hash']);
+        $this->assertArrayNotHasKey('crc32c', $metadata);
+    }
+
     /**
      * @dataProvider validationMethod
      */