public static void incrementIv(byte[] iv) {
    incrementIv(iv, 1);
  }
Decrypts a block of ciphertext with the symmetric key resolved for the given subject
@param out     plaintext
@param in      ciphertext
@param outLen  the expected plaintext length
@param subject the subject's key alias
@param conf    configuration
@param cipher  the encryption algorithm
@param iv      the initialization vector, can be null
hbase-common/src/main/java/org/apache/hadoop/hbase/io/crypto/Encryption.java