October 1, 2014

Setting up MySQL SSL and secure connections

There are different articles on how to setup MySQL with SSL but it’s sometimes difficult to end up with a good simple one. Usually, setting up MySQL SSL is not really a smooth process due to such factors like “it’s not your day”, something is broken apparently or the documentation lies :) I am going to provide the brief instructions on how to setup MySQL with SSL, SSL replication and how to establish secure connections from the console and scripts showing the working examples.

SSLQuick links:

 

Setup SSL on MySQL

1. Generate SSL certificates according to the example 1. Use the different Common Name for server and client certificates.

2. For the reference, I store the generated files under /etc/mysql-ssl/

3. Add the following lines to /etc/my.cnf under [mysqld] section:

# SSL
ssl-ca=/etc/mysql-ssl/ca-cert.pem
ssl-cert=/etc/mysql-ssl/server-cert.pem
ssl-key=/etc/mysql-ssl/server-key.pem

4. Restart MySQL.

5. Create an user to permit only SSL-encrypted connection:

GRANT ALL PRIVILEGES ON *.* TO ‘ssluser’@’%’ IDENTIFIED BY ‘pass’ REQUIRE SSL;

Establish secure connection from console

1. If the client is on a different node, copy /etc/mysql-ssl/ from the server to that node.

2. Add the following lines to /etc/my.cnf under [client]:

# SSL
ssl-cert=/etc/mysql-ssl/client-cert.pem
ssl-key=/etc/mysql-ssl/client-key.pem

3. Test a secure connection:

[root@centos6 ~]# mysql -u ssluser -p -sss -e ‘\s’ | grep SSL
SSL: Cipher in use is DHE-RSA-AES256-SHA

Setup SSL replication

1. Establish a secure connection from the console on slave like described above, to make sure SSL works fine.

2. On Master add “REQUIRE SSL” to the replication user:

GRANT REPLICATION SLAVE ON *.* to ‘repl’@’%’ REQUIRE SSL;

3. Change master options and restart slave:

STOP SLAVE;
CHANGE MASTER MASTER_SSL=1,
MASTER_SSL_CA=’/etc/mysql-ssl/ca-cert.pem’,
MASTER_SSL_CERT=’/etc/mysql-ssl/client-cert.pem’,
MASTER_SSL_KEY=’/etc/mysql-ssl/client-key.pem';

SHOW SLAVE STATUSG
START SLAVE;
SHOW SLAVE STATUSG

Establish secure connection from PHP

1. Install php and php-mysql packages. I use the version >=5.3.3, otherwise, it may not work.

2. Create the script:

[root@centos6 ~]# cat mysqli-ssl.php
$conn=mysqli_init();
mysqli_ssl_set($conn, ‘/etc/mysql-ssl/client-key.pem’, ‘/etc/mysql-ssl/client-cert.pem’, NULL, NULL, NULL);
if (!mysqli_real_connect($conn, ‘127.0.0.1’, ‘ssluser’, ‘pass’)) { die(); }
$res = mysqli_query($conn, ‘SHOW STATUS like “Ssl_cipher”‘);
print_r(mysqli_fetch_row($res));
mysqli_close($conn);

3. Test it:

[root@centos6 ~]# php mysqli-ssl.php
Array
(
[0] => Ssl_cipher
[1] => DHE-RSA-AES256-SHA
)

Establish secure connection from Python

1. Install MySQL-python package.

2. Create the script:

[root@centos6 ~]# cat mysql-ssl.py
#!/usr/bin/env python
import MySQLdb
ssl = {‘cert': ‘/etc/mysql-ssl/client-cert.pem’, ‘key': ‘/etc/mysql-ssl/client-key.pem’}
conn = MySQLdb.connect(host=’127.0.0.1′, user=’ssluser’, passwd=’pass’, ssl=ssl)
cursor = conn.cursor()
cursor.execute(‘SHOW STATUS like “Ssl_cipher”‘)
print cursor.fetchone()

3. Test it:

[root@centos6 ~]# python mysql-ssl.py
(‘Ssl_cipher’, ‘DHE-RSA-AES256-SHA’)

Notes

Alternative local SSL connection setup
If you connect locally to the server enabled for SSL you can also establish a secure connection this way:
1. Create ca.pem:

cd /etc/mysql-ssl/
cat server-cert.pem client-cert.pem > ca.pem

2. Have only the following ssl- lines in /etc/my.cnf under [client]:

# SSL
ssl-ca=/etc/mysql-ssl/ca.pem

Error with “ssl-ca” on local connections
If you left the line “ssl-ca=/etc/mysql-ssl/ca-cert.pem” under [client] section in /etc/my.cnf on the server enabled for SSL and try to establish local SSL connection, you will get “ERROR 2026 (HY000): SSL connection error: error:00000001:lib(0):func(0):reason(1)”.

Discrepancy in documentation
http://dev.mysql.com/doc/refman/5.5/en/using-ssl-connections.html says “A client can connect securely like this: shell> mysql –ssl-ca=ca-cert.pem” which does not work with “REQUIRE SSL”. You still have to supply the client cert and key for any or a combined client+server cert for a local secure connection.

About Roman Vynar

Roman is a Remote DBA in Percona. His duties include handling remote DBA ops, developing and improving of monitoring tools. He also maintains Percona Monitoring Plugins project.

Comments

  1. Did you file a bug about the documentation discrepancy?

  2. Roman Vynar says:

    Daniel, no I didn’t. May be under some unknown circumstances it can work somehow but it’s not the purpose of this article.

  3. Chris says:

    So how do you resolve “ERROR 2026″? Removing ssl-ca isn’t an option…

  4. Roman Vynar says:

    Chris, what’s your MySQL distribution/version if it’s not an option?

  5. Reinard Dolleschel says:

    Thanks for the post. One note though: I think you should discourage people from using the -p[pass] option on the command line. It shows up in the history and in the process list with the password exposed in plain text and is a horrible idea from a security standpoint. Especially when you’re just testing, just use -p and wait for it to prompt you for the password.

  6. Miklos Szel says:

    Hi Roman,

    First of all, good post, thanks!

    I know that this is not the point of this whole article but maybe it would be better to change the:
    GRANT USAGE ON *.* to ‘repl’@’%’ REQUIRE SSL;
    to
    GRANT REPLICATION SLAVE ON *.* to ‘repl’@’%’ REQUIRE SSL;
    as we speak about a replication and this could be a bit confusing.

  7. Roman Vynar says:

    Reinard, Miklos, thanks, I have made your notes.

  8. QS says:

    Looks like your escape character got lost in translation:

    [root@centos6 ~]# mysql -u ssluser -p -sss -e ‘s’ | grep SSL

    should be

    [root@centos6 ~]# mysql -u ssluser -p -sss -e ‘\s’ | grep SSL

  9. Roman Vynar says:

    Thanks QS. I had to put html backslash code \ instead.

  10. CHRIS says:

    I believe in step #3, “CHANGE MASTER MASTER_SSL=1″ should read “CHANGE MASTER TO MASTER_SSL=1″

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