Oracle recently announced a new authentication plugin: caching_sha2_password . This was added in 8.0.4 , the second release candidate for MySQL 8.0. The new plugin is also made the default (can be configured by changing default_authentication_plugin . Why? Phasing out SHA1 As Oracle said in the blog post to annouce this change they want to move to a more secure hashing algorithm ( SHA256 ). Which I think is a good reason to do this. Adding salt Adding a salt makes hashes for identical passwords, but different users different. Again a good reason to do this. Performance Their earlier attempt at this resulted in sha256_password . But this resulted in slower authentication. Without using persistent connections this is a serious limitation. So again a good reason. What's wrong? If you don't use SSL/TLS it gives your password away. To protect against sending the password in cleartext over an insecure connection it encrypts the password before sending it. It does this by ...

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 into improving TLS performance. This includes browser vendors, hardware vendors and much more. But instead of just hopi...

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 password and username from the loginpath from the encrypted ~/.mylogin.cnf file. ...

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: The client connects The server changes authentication to sha256 password (or default?) The server sends the RSA public key. The client encrypts the password with the RSA public key and sends it to the server. 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 server and then have the proxy sent its own public key... then we can decrypt it and reencode it with the real public key and send it to the server. Also the decrypted password is the password, not a hash. So we then know the real password. And if SSL is used it doesn't do the RSA encryption....

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: Checks if SSL is uses ( --ssl-mode=REQUIRED ) 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. Browsers by default verify hostnames, MySQL does not. Turning on hostname validation So use --ssl-mode=VERIFY_IDENTITY and everything should be fine? Well that might ...

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 MySQL connections if ok, adding a CA for groups of web...

Intro In my previous blog post I told you to use SSL/TLS to secure your MySQL network connections. So I followed my advice and did enable SSL. Great! So first let's quickly verify that everything is working. So you enabled SSL with mysql_ssl_rsa_setup , used a OpenSSL based build or put ssl-cert , ssl-key and ssl-ca in the mysqld section of your /etc/my.cnf and now show global variables like 'have_SSL'; returns 'YES'. And you have configured the client with --ssl-mode=PREFERRED . Now show global status like 'Ssl_cipher'; indicates the session is indeed secured. You could also dump traffic and it looks 'encrypted' (i.e. not readable)... With SSL enabled everything should be safe isn't it? The handshake which MySQL uses always starts unsecured and is upgraded to secured if both the client and server have the SSL flag set. This is very similar to STARTTLS as used in the SMTP protocol. To attach this we need an active attack; we need ...