diff --git a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
index 680486f..27afd47 100644
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -293,8 +293,12 @@
       getPathObjectId(git, path, revCommit).map { objectId =>
         if(raw){
           // Download
-          JGitUtil.getContentFromId(git, objectId, true).map { bytes =>
-            RawData("application/octet-stream", bytes)
+          JGitUtil.getObjectLoaderFromId(git, objectId){ loader =>
+            //RawData("application/octet-stream", bytes)
+            contentType = "application/octet-stream"
+            response.setContentLength(loader.getSize.toInt)
+            loader.copyTo(response.getOutputStream)
+            ()
           } getOrElse NotFound
         } else {
           html.blob(id, repository, path.split("/").toList,
diff --git a/src/main/scala/gitbucket/core/ssh/SshServerListener.scala b/src/main/scala/gitbucket/core/ssh/SshServerListener.scala
index 1288eb1..27f46ac 100644
--- a/src/main/scala/gitbucket/core/ssh/SshServerListener.scala
+++ b/src/main/scala/gitbucket/core/ssh/SshServerListener.scala
@@ -14,7 +14,7 @@
 
   private def configure(port: Int, baseUrl: String) = {
     server.setPort(port)
-    server.setKeyPairProvider(new SimpleGeneratorHostKeyProvider(s"${Directory.GitBucketHome}/gitbucket.ser"))
+    server.setKeyPairProvider(new SimpleGeneratorHostKeyProvider(s"${Directory.GitBucketHome}/gitbucket.ser", "RSA"))
     server.setPublickeyAuthenticator(new PublicKeyAuthenticator)
     server.setCommandFactory(new GitCommandFactory(baseUrl))
     server.setShellFactory(new NoShell)
diff --git a/src/main/scala/gitbucket/core/util/JGitUtil.scala b/src/main/scala/gitbucket/core/util/JGitUtil.scala
index 7ef25a7..7c77835 100644
--- a/src/main/scala/gitbucket/core/util/JGitUtil.scala
+++ b/src/main/scala/gitbucket/core/util/JGitUtil.scala
@@ -779,7 +779,7 @@
   def getContentFromId(git: Git, id: ObjectId, fetchLargeFile: Boolean): Option[Array[Byte]] = try {
     using(git.getRepository.getObjectDatabase){ db =>
       val loader = db.open(id)
-      if(fetchLargeFile == false && FileUtil.isLarge(loader.getSize)){
+      if(loader.isLarge || (fetchLargeFile == false && FileUtil.isLarge(loader.getSize))){
         None
       } else {
         Some(loader.getBytes)
@@ -790,6 +790,22 @@
   }
 
   /**
+   * Get objectLoader of the given object id from the Git repository.
+   *
+   * @param git the Git object
+   * @param id the object id
+   * @param f the function process ObjectLoader
+   * @return None if object does not exist
+   */
+  def getObjectLoaderFromId[A](git: Git, id: ObjectId)(f: ObjectLoader => A):Option[A] = try {
+    using(git.getRepository.getObjectDatabase){ db =>
+      Some(f(db.open(id)))
+    }
+  } catch {
+    case e: MissingObjectException => None
+  }
+
+  /**
    * Returns all commit id in the specified repository.
    */
   def getAllCommitIds(git: Git): Seq[String] = if(isEmpty(git)) {
diff --git a/src/main/twirl/gitbucket/core/helper/preview.scala.html b/src/main/twirl/gitbucket/core/helper/preview.scala.html
index 7f8e5c4..7402c85 100644
--- a/src/main/twirl/gitbucket/core/helper/preview.scala.html
+++ b/src/main/twirl/gitbucket/core/helper/preview.scala.html
@@ -8,6 +8,7 @@
   styleClass: String = "",
   placeholder: String = "Leave a comment",
   elastic: Boolean = false,
+  tabIndex: Int = -2,
   uid: Long = new java.util.Date().getTime())(implicit context: gitbucket.core.controller.Context)
 @import context._
 @import gitbucket.core._
@@ -22,6 +23,7 @@
       <span id="error-content" class="error"></span>
       @textarea = {
         <textarea id="content@uid" name="content" placeholder="@placeholder"
+          @if(tabIndex > -2){ tabindex="@tabIndex"}
           @if(style.nonEmpty){ style="@style"}
           @if(styleClass.nonEmpty){ class="@styleClass" }>@content</textarea>
       }
diff --git a/src/main/twirl/gitbucket/core/issues/commentform.scala.html b/src/main/twirl/gitbucket/core/issues/commentform.scala.html
index 511fe47..040b9e0 100644
--- a/src/main/twirl/gitbucket/core/issues/commentform.scala.html
+++ b/src/main/twirl/gitbucket/core/issues/commentform.scala.html
@@ -18,14 +18,15 @@
           enableTaskList     = true,
           hasWritePermission = hasWritePermission,
           style              = "",
-          elastic            = true
+          elastic            = true,
+          tabIndex           = 1
         )
         <div style="text-align: right;">
           <input type="hidden" name="issueId" value="@issue.issueId"/>
-          <input type="submit" class="btn btn-success" formaction="@url(repository)/issue_comments/new" value="Comment"/>
           @if((reopenable || !issue.closed) && (hasWritePermission || issue.openedUserName == loginAccount.get.userName)){
-            <input type="submit" class="btn" formaction="@url(repository)/issue_comments/state" value="@{if(issue.closed) "Reopen" else "Close"}" id="action"/>
+            <input type="submit" class="btn" tabindex="3" formaction="@url(repository)/issue_comments/state" value="@{if(issue.closed) "Reopen" else "Close"}" id="action"/>
           }
+          <input type="submit" class="btn btn-success" tabindex="2" formaction="@url(repository)/issue_comments/new" value="Comment"/>
         </div>
       </div>
     </div>