How to install Mail Service at Ubutu Live Serer (LEMP)

How to install Mail Service at Ubutu Live Serer (LEMP)

Install mailutils by the following command
apt-get install mailutils
apt-get install ssmtp

edit ssmtp.conf under /etc/ssmtp/ssmtp.conf
Remove “#” from “#FromLineOverride=YES” and add the following lines to ssmtp.conf

FromLineOverride=YES
AuthUser=youremail@gmail.com
AuthPass=yourpassword
mailhub=smtp.gmail.com:587
UseSTARTTLS=YES

After that, test email can send it or not with the following command
echo “tesitng” | mail -s “testing” william.aceplus@gmail.com

============================
Checking Error about mail
/var/log/mail.err
============================

if some setting are not and you want to re-configure the setting

Reconfigure / Resetting setting
sudo dpkg-reconfigure postfix
sudo dpkg-reconfigure mailutils
============================

 

Cheers

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Example syntax for Secure Copy (scp)

What is Secure Copy?

scp allows files to be copied to, from, or between different hosts. It uses ssh for data transfer and provides the same authentication and same level of security as ssh.

Examples

Copy the file “foobar.txt” from a remote host to the local host

$ scp your_username@remotehost.edu:foobar.txt /some/local/directory

Copy the file “foobar.txt” from the local host to a remote host

$ scp foobar.txt your_username@remotehost.edu:/some/remote/directory

Copy the directory “foo” from the local host to a remote host’s directory “bar”

$ scp -r foo your_username@remotehost.edu:/some/remote/directory/bar

Copy the file “foobar.txt” from remote host “rh1.edu” to remote host “rh2.edu”

$ scp your_username@rh1.edu:/some/remote/directory/foobar.txt \
your_username@rh2.edu:/some/remote/directory/

Copying the files “foo.txt” and “bar.txt” from the local host to your home directory on the remote host

$ scp foo.txt bar.txt your_username@remotehost.edu:~

Copy the file “foobar.txt” from the local host to a remote host using port 2264

$ scp -P 2264 foobar.txt your_username@remotehost.edu:/some/remote/directory

Copy multiple files from the remote host to your current directory on the local host

$ scp your_username@remotehost.edu:/some/remote/directory/\{a,b,c\} .
$ scp your_username@remotehost.edu:~/\{foo.txt,bar.txt\} .

scp Performance

By default scp uses the Triple-DES cipher to encrypt the data being sent. Using the Blowfish cipher has been shown to increase speed. This can be done by using option -c blowfish in the command line.

$ scp -c blowfish some_file your_username@remotehost.edu:~

It is often suggested that the -C option for compression should also be used to increase speed. The effect of compression, however, will only significantly increase speed if your connection is very slow. Otherwise it may just be adding extra burden to the CPU. An example of using blowfish and compression:

$ scp -c blowfish -C local_file your_username@remotehost.edu:~

Contributions

Thanks Stewart Macleod for port example.

Ref : http://www.hypexr.org/linux_scp_help.php

How to Use SSL Certificate in LEMP Digital Droplet

(1) We need to create two Certificate to give to SSL Certificate Vendor ( Z.com / GMO-ACE )
———————————-
examplesite.csr
examplesite.key
———————————-

=================================
How do I generate a CSR Code
=================================

———————————————————

OS – Ubuntu 14.04
Digital Ocean Droplet with LEMP
———————————————————

cd /etc/ssl
mkdir /etc/ssl/websitessl
openssl req -new -newkey rsa:2048 -nodes -keyout domainname.key -out domainname.csr

rsa:2048
“`means you create a 2048bits csr. I recommend for more security to use “`rsa:4069“`
You also need to change “`domainname.key“`and “`domainname.csr“` into your own domain name
so you can verify the CSR file. After you filled in all the legit information ,
you can open the new file using a client for example WinSCP, copy it, and use it for your SSL.


 

(2) And then, we have to buy/generate our SSL certificate at SSL Vendor Site and we will get / SSL vendor will generate the certificate files .
———————————–
samplesite.PEM
samplesite.ICA
samplesite.PKCS7
———————————–

We have to copy generated .PEM files from SSL Certifiate Provider to our host ( Digital Ocean LEMP )
http://www.examplesite.com.PEM.
And then, we have to edit the virtual host setting file at
/etc/nginx/site-available/samplesite

===================================================
Using SSL Certificate at Nginx Virtual Host Setting
===================================================
you have to create tow server blocks for both HTTP and HTTPS request.
And then, redirect to every request to HTTPS.

server {
listen 80;
server_name example.com.mm http://www.example.com.mm;
return 301 https://www.example.com.mm$request_uri;
}

server {
listen 443 ssl;
ssl on;

root /var/www/registrations/public;
index index.php index.html index.htm;

# Make site accessible from http://localhost/
server_name example.com.mm http://www.example.com.mm;
# server_name localhost;

access_log /var/log/nginx/nginx.vhost.access.log;
error_log /var/log/nginx/nginx.vhost.error.log;

ssl_certificate /etc/ssl/websitessl/www.example.com.mm.PEM;
ssl_certificate_key /etc/ssl/websitessl/examplesite.key;
ssl_trusted_certificate /etc/ssl/websitessl/www.example.com.mm.ICA;

ssl_ciphers “HIGH:!aNULL:!MD5 or HIGH:!aNULL:!MD5:3DES”;
ssl_prefer_server_ciphers on;

# to disable SSL3 service – to prevent the POODLE Vulnerablitiy attack
ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
# try_files $uri $uri/ =404;
try_files $uri $uri/ /index.php?$query_string;
# Uncomment to enable naxsi on this location
# include /etc/nginx/naxsi.rules
}

# Only for nginx-naxsi used with nginx-naxsi-ui : process denied requests
#location /RequestDenied {
# proxy_pass http://127.0.0.1:8080;
#}

#error_page 404 /404.html;

# redirect server error pages to the static page /50x.html
#
#error_page 500 502 503 504 /50x.html;
#location = /50x.html {
# root /usr/share/nginx/html;
#}

# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~ \.php$ {
fastcgi_split_path_info ^(.+\.php)(/.+)$;
# # NOTE: You should have “cgi.fix_pathinfo = 0;” in php.ini
#
# # With php5-cgi alone:
# fastcgi_pass 127.0.0.1:9000;
# # With php5-fpm:
fastcgi_pass unix:/var/run/php5-fpm.sock;
fastcgi_index index.php;
include fastcgi_params;
}

# deny access to .htaccess files, if Apache’s document root
# concurs with nginx’s one
#
location ~ /\.ht {
deny all;
}

client_max_body_size 10M;
}

—————————————————————————————

Installing Phpmyadmin at Ubuntu 14.04/16.04 with LEMP

1)  sudo apt-get install phpmyadmin

2) check where is the site
cd /usr/share/nginx/html

3) sudo ln  -s /usr/share/phpmyadmin/ /usr/share/nginx/html
it will create a new link name “phpmyadmin” under /user/share/nginx/html
if you want to create custom phpmyadmin link, you can create by the following command
sudo ln  -s /usr/share/phpmyadmin_mycustom_name/ /usr/share/nginx/html
it will create a new link name “phpmyadmin_mycustom_name” under /user/share/nginx/html
And we can call it from browser by “http://ip_address/phpmyadmin” or “http://ip_address/phpmyadmin_mycustom_name”

4) sudo systemctl restart nginx

5) if there is “root /var/www/html” at /etc/nginx/sites-available/default, comment out it
eg ” # root /var/www/html ” and change server_name to
server_name localhost / ip_address;

6) if “cgi.fix_pathinfo = 0” at /etc/php/7.0/fpm/php.ini, pls change back to original “cgi.fix_pathinfo = 1”
sudo systemctl restart nginx

UFW Essentials: Common Firewall Rules and Commands

Reference
https://www.digitalocean.com/community/tutorials/ufw-essentials-common-firewall-rules-and-commands

 

Introduction

UFW is a ll configuration tool for iptables that is included with Ubuntu by default. This cheat sheet-style guide provides a quick reference to UFW commands that will create iptables firewall rules are useful in common, everyday scenarios. This includes UFW examples of allowing and blocking various services by port, network interface, and source IP address.

How To Use This Guide

  • If you are just getting started with using UFW to configure your firewall, check out our introduction to UFW
  • Most of the rules that are described here assume that you are using the default UFW ruleset. That is, it is set to allow outgoing and deny incoming traffic, through the default policies, so you have to selectively allow traffic in
  • Use whichever subsequent sections are applicable to what you are trying to achieve. Most sections are not predicated on any other, so you can use the examples below independently
  • Use the Contents menu on the right side of this page (at wide page widths) or your browser’s find function to locate the sections you need
  • Copy and paste the command-line examples given, substituting the values in red with your own values

Remember that you can check your current UFW ruleset with sudo ufw status or sudo ufw status verbose.

If “ufw” service is inactive, u can run it by
sudo ufw enable

Block an IP Address

To block all network connections that originate from a specific IP address, 15.15.15.51 for example, run this command:

  • sudo ufw deny from 15.15.15.51

In this example, from 15.15.15.51 specifies a source IP address of “15.15.15.51”. If you wish, a subnet, such as 15.15.15.0/24, may be specified here instead. The source IP address can be specified in any firewall rule, including an allow rule.

Block Connections to a Network Interface

To block connections from a specific IP address, e.g. 15.15.15.51, to a specific network interface, e.g. eth0, use this command:

  • sudo ufw deny in on eth0 from 15.15.15.51

This is the same as the previous example, with the addition of in on eth0. The network interface can be specified in any firewall rule, and is a great way to limit the rule to a particular network.

Service: SSH

If you’re using a cloud server, you will probably want to allow incoming SSH connections (port 22) so you can connect to and manage your server. This section covers how to configure your firewall with various SSH-related rules.

Allow SSH

To allow all incoming SSH connections run this command:

  • sudo ufw allow ssh

An alternative syntax is to specify the port number of the SSH service:

  • sudo ufw allow 22

Allow Incoming SSH from Specific IP Address or Subnet

To allow incoming SSH connections from a specific IP address or subnet, specify the source. For example, if you want to allow the entire 15.15.15.0/24 subnet, run this command:

  • sudo ufw allow from 15.15.15.0/24 to any port 22

Allow Incoming Rsync from Specific IP Address or Subnet

Rsync, which runs on port 873, can be used to transfer files from one computer to another.

To allow incoming rsync connections from a specific IP address or subnet, specify the source IP address and the destination port. For example, if you want to allow the entire 15.15.15.0/24 subnet to be able to rsync to your server, run this command:

  • sudo ufw allow from 15.15.15.0/24 to any port 873

Service: Web Server

Web servers, such as Apache and Nginx, typically listen for requests on port 80 and 443 for HTTP and HTTPS connections, respectively. If your default policy for incoming traffic is set to drop or deny, you will want to create rules that will allow your server to respond to those requests.

Allow All Incoming HTTP

To allow all incoming HTTP (port 80) connections run this command:

  • sudo ufw allow http

An alternative syntax is to specify the port number of the HTTP service:

  • sudo ufw allow 80

Allow All Incoming HTTPS

To allow all incoming HTTPS (port 443) connections run this command:

  • sudo ufw allow https

An alternative syntax is to specify the port number of the HTTPS service:

  • sudo ufw allow 443

Allow All Incoming HTTP and HTTPS

If you want to allow both HTTP and HTTPS traffic, you can create a single rule that allows both ports. To allow all incoming HTTP and HTTPS (port 443) connections run this command:

  • sudo ufw allow proto tcp from any to any port 80,443

Note that you need to specify the protocol, with proto tcp, when specifying multiple ports.

Service: MySQL

MySQL listens for client connections on port 3306. If your MySQL database server is being used by a client on a remote server, you need to be sure to allow that traffic.

Allow MySQL from Specific IP Address or Subnet

To allow incoming MySQL connections from a specific IP address or subnet, specify the source. For example, if you want to allow the entire 15.15.15.0/24 subnet, run this command:

  • sudo ufw allow from 15.15.15.0/24 to any port 3306

Allow MySQL to Specific Network Interface

To allow MySQL connections to a specific network interface—say you have a private network interface eth1, for example—use this command:

  • sudo ufw allow in on eth1 to any port 3306
  • sudo ufw allow 3306/tcp
    sudo service ufw restart

Service: PostgreSQL

PostgreSQL listens for client connections on port 5432. If your PostgreSQL database server is being used by a client on a remote server, you need to be sure to allow that traffic.

PostgreSQL from Specific IP Address or Subnet

To allow incoming PostgreSQL connections from a specific IP address or subnet, specify the source. For example, if you want to allow the entire 15.15.15.0/24 subnet, run this command:

  • sudo ufw allow from 15.15.15.0/24 to any port 5432

The second command, which allows the outgoing traffic of established PostgreSQL connections, is only necessary if the OUTPUT policy is not set to ACCEPT.

Allow PostgreSQL to Specific Network Interface

To allow PostgreSQL connections to a specific network interface—say you have a private network interface eth1, for example—use this command:

  • sudo ufw allow in on eth1 to any port 5432

The second command, which allows the outgoing traffic of established PostgreSQL connections, is only necessary if the OUTPUT policy is not set to ACCEPT.

Service: Mail

Mail servers, such as Sendmail and Postfix, listen on a variety of ports depending on the protocols being used for mail delivery. If you are running a mail server, determine which protocols you are using and allow the appropriate types of traffic. We will also show you how to create a rule to block outgoing SMTP mail.

Block Outgoing SMTP Mail

If your server shouldn’t be sending outgoing mail, you may want to block that kind of traffic. To block outgoing SMTP mail, which uses port 25, run this command:

  • sudo ufw deny out 25

This configures your firewall to drop all outgoing traffic on port 25. If you need to reject a different service by its port number, instead of port 25, simply replace it.

Allow All Incoming SMTP

To allow your server to respond to SMTP connections, port 25, run this command:

  • sudo ufw allow 25

Note: It is common for SMTP servers to use port 587 for outbound mail.

Allow All Incoming IMAP

To allow your server to respond to IMAP connections, port 143, run this command:

  • sudo ufw allow 143

Allow All Incoming IMAPS

To allow your server to respond to IMAPS connections, port 993, run this command:

  • sudo ufw allow 993

Allow All Incoming POP3

To allow your server to respond to POP3 connections, port 110, run this command:

  • sudo ufw allow 110

Allow All Incoming POP3S

To allow your server to respond to POP3S connections, port 995, run this command:

  • sudo ufw allow 995
  • sudo apt-get install ufw

=========================================================================

Reference

https://www.digitalocean.com/community/tutorials/how-to-set-up-a-firewall-with-ufw-on-ubuntu-14-04

Using IPv6 with UFW

If your Ubuntu server has IPv6 enabled, ensure that UFW is configured to support IPv6 so that it will manage firewall rules for IPv6 in addition to IPv4. To do this, open the UFW configuration with your favorite editor. We’ll use nano:

  • sudo nano /etc/default/ufw

Then make sure the value of “IPV6” is to equal “yes”. It should look like this:

/etc/default/ufw excerpt
...
IPV6=yes
...

Save and quit. Hit Ctrl-X to exit the file, then Y to save the changes that you made, then ENTER to confirm the file name.

When UFW is enabled, it will be configured to write both IPv4 and IPv6 firewall rules.

This tutorial is written with IPv4 in mind, but will work fine for IPv6 as long as you enable it.

Check UFW Status and Rules

At any time, you can check the status of UFW with this command:

  • sudo ufw status verbose

By default, UFW is disabled so you should see something like this:

Output:
Status: inactive

If UFW is active, the output will say that it’s active, and it will list any rules that are set. For example, if the firewall is set to allow SSH (port 22) connections from anywhere, the output might look something like this:

Output:
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip

To                         Action      From
--                         ------      ----
22/tcp                     ALLOW IN    Anywhere

As such, use the status command if you ever need to check how UFW has configured the firewall.

Before enabling UFW, we will want to ensure that your firewall is configured to allow you to connect via SSH. Let’s start with setting the default policies.

Set Up Default Policies

If you’re just getting started with your firewall, the first rules to define are your default policies. These rules control how to handle traffic that does not explicitly match any other rules. By default, UFW is set to deny all incoming connections and allow all outgoing connections. This means anyone trying to reach your cloud server would not be able to connect, while any application within the server would be able to reach the outside world.

Let’s set your UFW rules back to the defaults so we can be sure that you’ll be able to follow along with this tutorial. To set the defaults used by UFW, use these commands:

  • sudo ufw default deny incoming
  • sudo ufw default allow outgoing

As you might have guessed, these commands set the defaults to deny incoming and allow outgoing connections. These firewall defaults, by themselves, might suffice for a personal computer but servers typically need to respond to incoming requests from outside users. We’ll look into that next.

Allow SSH Connections

If we enabled our UFW firewall now, it would deny all incoming connections. This means that we will need to create rules that explicitly allow legitimate incoming connections—SSH or HTTP connections, for example—if we want our server to respond to those types of requests. If you’re using a cloud server, you will probably want to allow incoming SSH connections so you can connect to and manage your server.

To configure your server to allow incoming SSH connections, you can use this UFW command:

  • sudo ufw allow ssh

This will create firewall rules that will allow all connections on port 22, which is the port that the SSH daemon listens on. UFW knows what “ssh”, and a bunch of other service names, means because it’s listed as a service that uses port 22 in the /etc/services file.

We can actually write the equivalent rule by specifying the port instead of the service name. For example, this command works the same as the one above:

  • sudo ufw allow 22

If you configured your SSH daemon to use a different port, you will have to specify the appropriate port. For example, if your SSH server is listening on port 2222, you can use this command to allow connections on that port:

  • sudo ufw allow 2222

Now that your firewall is configured to allow incoming SSH connections, we can enable it.

Enable UFW

To enable UFW, use this command:

  • sudo ufw enable

You will receive a warning that says the “command may disrupt existing ssh connections.” We already set up a firewall rule that allows SSH connections so it should be fine to continue. Respond to the prompt with y.

The firewall is now active. Feel free to run the sudo ufw status verbose command to see the rules that are set.

Allow Other Connections

Now you should allow all of the other connections that your server needs to respond to. The connections that you should allow depends your specific needs. Luckily, you already know how to write rules that allow connections based on a service name or port—we already did this for SSH on port 22.

We will show a few examples of very common services that you may need to allow. If you have any other services for which you want to allow all incoming connections, follow this format.

HTTP—port 80

HTTP connections, which is what unencrypted web servers use, can be allowed with this command:

  • sudo ufw allow http

If you’d rather use the port number, 80, use this command:

  • sudo ufw allow 80

HTTPS—port 443

HTTPS connections, which is what encrypted web servers use, can be allowed with this command:

  • sudo ufw allow https

If you’d rather use the port number, 443, use this command:

  • sudo ufw allow 443

FTP—port 21

FTP connections, which is used for unencrypted file transfers (which you probably shouldn’t use anyway), can be allowed with this command:

  • sudo ufw allow ftp

If you’d rather use the port number, 21, use this command:

  • sudo ufw allow 21/tcp

Allow Specific Port Ranges

You can specify port ranges with UFW. Some applications use multiple ports, instead of a single port.

For example, to allow X11 connections, which use ports 6000-6007, use these commands:

  • sudo ufw allow 6000:6007/tcp
  • sudo ufw allow 6000:6007/udp

When specifying port ranges with UFW, you must specify the protocol (tcp or udp) that the rules should apply to. We haven’t mentioned this before because not specifying the protocol simply allows both protocols, which is OK in most cases.

Allow Specific IP Addresses

When working with UFW, you can also specify IP addresses. For example, if you want to allow connections from a specific IP address, such as a work or home IP address of 15.15.15.51, you need to specify “from” then the IP address:

  • sudo ufw allow from 15.15.15.51

You can also specify a specific port that the IP address is allowed to connect to by adding “to any port” followed by the port number. For example, If you want to allow 15.15.15.51 to connect to port 22 (SSH), use this command:

sudo ufw allow from 15.15.15.51 to any port 22

Allow Subnets

If you want to allow a subnet of IP addresses, you can do so using CIDR notation to specify a netmask. For example, if you want to allow all of the IP addresses ranging from 15.15.15.1 to 15.15.15.254 you could use this command:

  • sudo ufw allow from 15.15.15.0/24

Likewise, you may also specify the destination port that the subnet 15.15.15.0/24 is allowed to connect to. Again, we’ll use port 22 (SSH) as an example:

sudo ufw allow from 15.15.15.0/24 to any port 22

Allow Connections to a Specific Network Interface

If you want to create a firewall rule that only applies to a specific network interface, you can do so by specifying “allow in on” followed by the name of the network interface.

You may want to look up your network interfaces before continuing. To do so, use this command:

  • ip addr
Output Excerpt:
...
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
...
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default 
...

The highlighted output indicates the network interface names. They are typically named something like “eth0” or “eth1”.

So, if your server has a public network interface called eth0, you could allow HTTP traffic (port 80) to it with this command:

  • sudo ufw allow in on eth0 to any port 80

Doing so would allow your server to receive HTTP requests from the public Internet.

Or, if you want your MySQL database server (port 3306) to listen for connections on the private network interface eth1, for example, you could use this command:

  • sudo ufw allow in on eth1 to any port 3306

This would allow other servers on your private network to connect to your MySQL database.

Deny Connections

If you haven’t changed the default policy for incoming connections, UFW is configured to deny all incoming connections. Generally, this simplifies the process of creating a secure firewall policy by requiring you to create rules that explicitly allow specific ports and IP addresses through. However, sometimes you will want to deny specific connections based on the source IP address or subnet, perhaps because you know that your server is being attacked from there. Also, if you want change your default incoming policy to allow (which isn’t recommended in the interest of security), you would need to create deny rules for any services or IP addresses that you don’t want to allow connections for.

To write deny rules, you can use the commands that we described above except you need to replace “allow” with “deny”.

For example to deny HTTP connections, you could use this command:

  • sudo ufw deny http

Or if you want to deny all connections from 15.15.15.51 you could use this command:

sudo ufw deny from 15.15.15.51

If you need help writing any other deny rules, just look at the previous allow rules and update them accordingly.

Now let’s take a look at how to delete rules.

Delete Rules

Knowing how to delete firewall rules is just as important as knowing how to create them. There are two different ways specify which rules to delete: by rule number or by the actual rule (similar to how the rules were specified when they were created). We’ll start with the delete by rule number method because it is easier, compared to writing the actual rules to delete, if you’re new to UFW.

By Rule Number

If you’re using the rule number to delete firewall rules, the first thing you’ll want to do is get a list of your firewall rules. The UFW status command has an option to display numbers next to each rule, as demonstrated here:

  • sudo ufw status numbered
Numbered Output:
Status: active

     To                         Action      From
     --                         ------      ----
[ 1] 22                         ALLOW IN    15.15.15.0/24
[ 2] 80                         ALLOW IN    Anywhere

If we decide that we want to delete rule 2, the one that allows port 80 (HTTP) connections, we can specify it in a UFW delete command like this:

  • sudo ufw delete 2

This would show a confirmation prompt then delete rule 2, which allows HTTP connections. Note that if you have IPv6 enabled, you would want to delete the corresponding IPv6 rule as well.

By Actual Rule

The alternative to rule numbers is to specify the actual rule to delete. For example, if you want to remove the “allow http” rule, you could write it like this:

  • sudo ufw delete allow http

You could also specify the rule by “allow 80”, instead of by service name:

  • sudo ufw delete allow 80

This method will delete both IPv4 and IPv6 rules, if they exist.

How To Disable UFW (optional)

If you decide you don’t want to use UFW for whatever reason, you can disable it with this command:

  • sudo ufw disable

Any rules that you created with UFW will no longer be active. You can always run sudo ufw enable if you need to activate it later.

Reset UFW Rules (optional)

If you already have UFW rules configured but you decide that you want to start over, you can use the reset command:

  • sudo ufw reset

This will disable UFW and delete any rules that were previously defined. Keep in mind that the default policies won’t change to their original settings, if you modified them at any point. This should give you a fresh start with UFW.