Error while connecting MySQL Workbench SSH tunnelling with AWS EC2 (Linux -Free tier)

Question

First what I have done so far

In AWS

1. In Security group given 3306 port access for all MySQL/Aurora:
   

2. Created a .pem key and saved it.

PuTTY

I am able to connect to MySQL (5.7) using PuTTY

1. Created new user: create user 'admin'@'localhost' identified by 'xxxxxxx';

2. Granted all the permission for DB: grant all privileges ON db.* to 'admin'@'localhost';

3. I am able to login using new user admin and new pass mysql -u admin -p

4. Changed /etc/my.cnf; added bind-address=0.0.0.0 (tried with and without):
   

MySQL Workbench

1. Tried SSH hostname:

   • a. x.x.x.x:22
   • b. x.x.x.x
   • c. DNS endpoint :22
   • d. DNS endpoint
2. Tried SSH Username:
   • a. ec2-user (as suggested by AWS)
   • b. ubuntu
3. MySQL host name:
   • a. Port no 127.0.0.1
   • b. localhost Workbench setting:
     
     I have mixed all the possible combination of above. but still getting this error:
     

Please resolve the issue.