HADOOP-10791. AuthenticationFilter should support externalizing the secret for signing and provide rotation support. (rkanter via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1616006 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10933. FileBasedKeyStoresFactory Should use Configuration.getPassword for SSL Passwords. (lmccay via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1616009 13f79535-47bb-0310-9956-ffa450edef68