How to reverse the b64 format(encoded b64(b64(md5($pass)))) into md5 hash format?

Shell Programming and Scripting
1

I have about 1500 rows (encoded b64(b64(md5($pass))) algorythm) in a file.

I would like reverse the b64 into md5 hash format.
How could I do that from command line? So I need only the correct md5 hash formats.

These row format:

4G5qc2WQzGES6QkWAUgl5w
P9tKxonBOg3ymr8vOBLnDA
Lk7X7MxDgnJB8Q2Ara4wgQ
FLTI8uRiXQ8WsmrsY5I2Kg
9x1MIvDOyQnfusEShe4Mow
FUoZYzDwD6kEWxWMIsvxbg
5Z9LKc013FROw4qKh+32cQ
2

/tmp/base64.txt if you base64 values file

#!/bin/bash

input_file="/tmp/base64.txt"
ouput_file="/tmp/out.txt"


while read base_value
do
    echo "${base_value}" | base64 --decode >> ${ouput_file}
done < "${input_file}"