https://issues.apache.org/jira/browse/CODEC-188
http://commons.apache.org/proper/commons-codec/archives/1.10/apidocs/org/apache/commons/codec/digest/HmacUtils.html
http://commons.apache.org/proper/commons-codec/archives/1.10/apidocs/src-html/org/apache/commons/codec/digest/HmacUtils.html#line.419
public static Mac getHmacSha256(final byte[] key) {
public static Mac getInitializedMac(final String algorithm, final byte[] key) {
javax.crypto.spec.SecretKeySpec
javax.crypto.Mac
https://github.com/apache/commons-codec/blob/trunk/src/main/java/org/apache/commons/codec/digest/HmacAlgorithms.java