In this blog post, we’ll look at how to set up Percona PAM with Active Directory for external authentication.

In my previous article on Percona PAM, I demonstrated how to use Samba as a domain, and how easy it is to create domain users and groups via the samba-tool. Then we configured nss-pam-ldapd and nscd to enumerate user and group information via LDAP calls, and authenticate users from this source.

This time around, I will demonstrate two other ways of using Active Directory for external authentication by joining the domain via SSSD or Winbind. System Security Services Daemon (SSSD) allows you to configure …

Join Percona’s Chief Evangelist, Colin Charles as he presents Securing Your MySQL/MariaDB Data on Tuesday, July 11, 2017 at 7:00 am PDT / 10:00 am EDT (UTC-7).

Register Now

This webinar will discuss the features of MySQL/MariaDB that when enabled and used improve the default usage of MySQL. Many cloud-based applications fail to:

• Use appropriate filesystem permissions
• Employ TLS/SSL for connections
• Require TLS/SSL with MySQL replication
• Use external authentication plugins (LDAP, PAM, Kerberos)
• Encrypt all your data at rest …

This blog post looks at SSL connections and how they work in MySQL 5.7.

Recently I was working on an SSL implementation with MySQL 5.7, and I made some interesting discoveries. I realized I could connect to the MySQL server without specifying the SSL keys on the client side, and the connection is still secured by SSL. I was confused and I did not understand what was happening.

In this blog post, I am going to show you why SSL works in MySQL 5.7, and it worked previously in MySQL 5.6.

Let’s start with an introduction of how SSL worked in 5.6.

SSL in MySQL 5.6

The documentation for SSL in MySQL 5.6 is quite detailed, and it explains how SSL works. But first let’s make one thing …

Often databases contain data that needs to be proven as valid and authentic. We want to ensure that a known person or other sender (e.g. a trusted app) of the information can’t deny content, nor that the content can change without that person (senders) consent.…

In conversations about SSL/TLS people often say that they either don't need TLS because they trust their network or they say it is too slow to be used in production.

With TLS the client and server has to do additional work, so some overhead is expected. But the price of this overhead also gives you something in return: more secure communication and more authentication options (client certificates).

SSL and TLS have existed for quite a long time. First they were only used for online banking and during authentication on web sites. But slowly many websites went to full-on SSL/TLS. And with the introduction of Let's encrypt many small websites are now using SSL/TLS. And many non-HTTP protocols either add encryption or move to a HTTP based protocol.

So TLS performance is very important for day-to-day usage. Many people and companies have put a lot of effort …

In this blog post, we’ll look at a feature that recently added to Percona XtraDB Cluster 5.7.16, that makes it easier to configure Percona XtraDB Cluster SSL for all related communications. It uses mode “encrypt=4”, and configures SSL for both IST/Galera communications and SST communications using the same SSL files. “encrypt=4” is a new encryption mode added in Percona XtraDB Cluster 5.7.16 (we’ll cover it in a later blog post).

If this option is used, this will override all other Galera/SST SSL-related file options. This is to ensure that a consistent configuration is applied. Using this option also means that the Galera/SST communications are …

Backup traffic

After securing application-to-database and replication traffic, you should also do the same for backup traffic.

If you use Percona XtraBackup with streaming than you should use SSH to send your backup to a secure location. The same is true for MySQL Enterprise Backup. Also both have options to encrypt the backup itself. If you send your backup to a cloud service this is something you should really do, especially if it is not sent via SSH or HTTPS.

And mysqldump and mysqlbinlog both support SSL. And you could use GnuPG, OpenSSL, WinZIP or any other tool to encrypt it.

Sending credentials

You could try to force the client to send credentials elsewhere. This can be done if you can control the parameters to the mysql client. It reads the config from /etc/my.cnf, ~/.my.cnf and ~/.mylogin.conf but if you for example specify a login-path and a hostname.. it connects to that host, but with the …

The mysql_sha256_password doesn't use the nonce system which is used for mysql_new_password, but instead forces the use of RSA or SSL.

This is how that works:

1. The client connects
2. The server changes authentication to sha256 password (or default?)
3. The server sends the RSA public key.
4. The client encrypts the password with the RSA public key and sends it to the server.
5. The server decrypts the password with the private key and validates it.

The problem is that the client trusts public key of the server. It is possible to use --server-public-key-path=file_name. But then you need to take care of secure public key distribution yourself.

So if we put a proxy between the client and the …

In my previous blogs I told you to enable SSL/TLS and configure it to check the CA. So I followed my advice and did all that. Great!

So the --ssl-mode setting was used a few times as a solution. And it has a setting we didn't use yet: VERIFY_IDENTITY. In older MySQL versions you can use --ssl-verify-server-cert. Both turn on hostname verification.

The attack

Get any certificate which is trusted by the configured CA, this can for example be a certificate from a development machine. And use that with a man-in-the-middle proxy.

Then the client:

1. Checks if SSL is uses (--ssl-mode=REQUIRED)
2. Verify if the certificate is signed by a trusted CA (--ssl-mode=VERIFY_CA)

Both checks succeed. But the certificate might be for testhost01.example.com and the database server might be prod-websitedb-123.example.com. …

In my previous blogs I told you to enable SSL/TLS and force the connection to be secured. So I followed my advice and did forced SSL. Great!

So now everything is 100% secure isn't it?

No it isn't and I would never claim anything to be 100% secure.

There are important differences in the SSL/TLS implementations of browers and the implementation in MySQL. One of these differences is that your browser has a trust store with a large set of trusted certificate authorities. If the website you visit has SSL enabled then your browser will check if the certificate it presents is signed by a trusted CA. MySQL doesn't use a list of trusted CA's, and this makes sense for many setups.

The key difference is that a website has clients (browsers) which are not managed by the same organization. And for MySQL connections the set of clients is often much smaller are more or less managed by one organization. Adding a CA for a set of …