Oracle DB unix/linux autostart - oracle user no login shell
The init.d script has to be modified by adding "-s /bin/bash" to the start and stop case. This should allow the oracle user to be login without the password.

#!/bin/bash
# chkconfig: 35 99 10
# description: Starts and stops Oracle processes

ORA_HOME=/opt/oracle/product/12cR1/db
ORA_OWNER=oracle

PATH=${PATH}:$ORACLE_HOME/bin
HOST=`hostname`
PLATFORM=`uname`
export ORACLE_HOME PATH
case $1 in
'start')
        su - $ORA_OWNER -s /bin/bash -c "$ORA_HOME/bin/lsnrctl start"
        su - $ORA_OWNER -s /bin/bash -c "$ORA_HOME/bin/dbstart"
        ;;
'stop')
        su - $ORA_OWNER -s /bin/bash -c "$ORA_HOME/bin/lsnrctl stop"
        su - $ORA_OWNER -s /bin/bash -c "$ORA_HOME/bin/dbshut"
        ;;
*)
        echo "usage: $0 {start|stop}"
        exit 1
esac
#
exit