private static SecretKeySpec keySpecFromSecretKey(String secretKey) {
        if (!keySpecs.containsKey(secretKey)) {
            byte[] ivraw = secretKey.getBytes();
            SecretKeySpec skeySpec = new SecretKeySpec(ivraw, "AES"); //$NON-NLS-1$
            keySpecs.put(secretKey, skeySpec);
        }
        return keySpecs.get(secretKey);
    }
Returns a {@link SecretKeySpec} given a secret key.
@param secretKey
common/util/src/main/java/io/apiman/common/util/AesEncrypter.java