The help file below displays asnodeadmin options, which can be used to configure node users.
# /opt/aspera/bin/asnodeadmin -h

Usage: asnodeadmin [options]

Options:
  -h,--help                       Display usage
  -A,--version                    Display version
  -f <conf_file>                  Conf file pathname (default: aspera.conf)
  -a,--add                        Add
  -d,--del[ete]                   Delete
  -m,--mod[ify]                   Modify
  -l,--list                       List user(s)
  -u,--user=<username>            Specify username
  -p,--{pwd|password}=<password>  Specify password
  -x,--xuser=<xfer_username>      Specify system transfer user
  -b,--backup=<filename>          Back-up user data to a file
  -r,--restore=<filename>         Restore user data from a file; however, it does NOT remove current users.
  --reload                        Indicates to the node daemon that it should reload the configuration      
  -P                              Display hashed password(s) as well upon listing user(s)
  -L <local_log_dir>              Local logging directory (default: no logging)
  -D...                           Debug level (default: no debug output)