Decode an input String using Base64.
Base64.decode64(str)
str - The String to be decoded
Returns the Base64-decoded version of str. This method complies with RFC 2045. Characters outside the base alphabet are ignored.
require "base64"
encoded_string = 'YmFzZTY0IGVuY29kZWQgc3RyaW5n'
decoded_string = Base64.decode64(encoded_string)