Category Archives: MySQL

Thoughts about MySQL.

Simplified SSL/TLS Setup for MySQL Community

Transport Layer Security (TLS, also often referred to as SSL) is an important component of a secure MySQL deployment, but the complexities of properly generating the necessary key material and configuring the server dissuaded many users from completing this task.  MySQL Server 5.7 simplifies this task for both Enterprise and Community users.  Previous blog posts have detailed the changes supporting Enterprise builds; this blog post will focus on parallel improvements made to MySQL Community builds.

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Which accounts can access this data?

Knowing which privileges a given account has is easy – just issue SHOW GRANTS FOR user@host.  But what about when you need visibility into privileges from the other direction – which accounts can access specific data?  If you’re a DBA – or perform DBA duties, regardless of your title – you may have been asked this question.  It’s an important question to ask in an audit or compliance review – but it can be a difficult question to answer.    This post will walk through how to assess this, but if you’re impatient and need answers to this question immediately, jump to the end – there’s a simple shortcut. Continue reading Which accounts can access this data?

Secure Java Connections by Default

MySQL Connector/Java 5.1.38 was released earlier this week, and it includes a notable improvement related to secure connections.  Here’s how the change log describes it:

When connecting to a MySQL server 5.7 instance that supports TLS, Connector/J now prefers a TLS over a plain TCP connection.

This mirrors changes made in 5.7 to the behavior of MySQL command-line clients and libmysql client library.  Coupled with the streamlined/automatic generation of TLS key material to ensure TLS availability in MySQL Server 5.7 deployments, this is an important step towards providing secure communication in default deployments. Continue reading Secure Java Connections by Default

Practical P_S: Find Client JRE Version Using SQL

MySQL Connector/Java supports connection attributes since version 5.1.25.  This projects useful metadata about the client environment into the database, where MySQL administrators can query PERFORMANCE_SCHEMA tables to remotely survey application deployment environments.  One useful piece of information exposed is the version and vendor of the JVM in use by the client.  This very short blog demonstrates how to get this information from PERFORMANCE_SCHEMA.

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SSL/TLS Improvements in MySQL 5.7.10

Secure communications is a core component of a robust security policy, and MySQL Server 5.7.10 – the first maintenance release of MySQL Server 5.7 – introduces needed improvements in this area.  Support for TLS has been expanded from TLSv1.0 to include TLSv1.1 and TLSv1.2, default ciphers have been updated, and controls have been implemented allowing both server and client-side configuration of acceptable TLS protocol versions.  This blog post will describe the changes, the context in which these changes were made, note important differences in capabilities between Community and Enterprise versions, and outline future plans. Continue reading SSL/TLS Improvements in MySQL 5.7.10

Protecting MySQL passwords with sha256_password plugin

Over the years, MySQL has used three different mechanisms for securing passwords both for storage and for transmission across networks.  This blog post aims to provide a brief history of the various mechanisms and highlight reasons to migrate accounts to use the sha256_password mechanism introduced in MySQL Server 5.6. Continue reading Protecting MySQL passwords with sha256_password plugin

SSL/TLS Connections to Recent MySQL Servers in Java

Recent changes to support better security by increasing strength of Diffie-Hellman cipher suites from 512-bit to 2048-bit were introduced to MySQL Server 5.7. While this change enhances security, it is an aggressive change in that 2048-bit DH ciphers are not universally supported. This has become a problem specifically for Java users, as only Java 8 JRE (currently) supports DH ciphers greater than 1024 bits. Making the problem more acute, this change was back-ported from MySQL Server 5.7 to the recent 5.6.26 and 5.5.45 releases in response to a community bug report. This blog post will identify affected applications, existing workarounds, and our plans to provide a more permanent solution in upcoming maintenance releases.
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Proposal: Adding consistency to protocol selection

If you run multiple MySQL instances on a Linux machine, chances are good that at one time or another, you’ve ended up connected to an instance other than what you had intended. It’s certainly happened to me, and I submitted Bug#76512 to deal with the cause which affects me most commonly – that the mysql client will silently ignore the –port option and connect using the default Unix socket instead when the host is “localhost” (default).  We’ve recently discussed ways we can make this behavior less surprising to users, and though we’re now past the second RC of MySQL Server 5.7, we’re contemplating making these changes in future 5.7 releases.  Please let us know your thoughts!

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Identifying which connections are secure

A key theme of the MySQL Server 5.7 release is much improved security.  Earlier releases of MySQL 5.7 have introduced features supporting this initiative including automatic generation and detection of TLS key material and client-side preference for TLS connections.  The recent MySQL 5.7.8 release builds upon this and provides additional monitoring and audit capabilities that make it easy to answer the question, “How secure are my client connections?”

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SSL/TLS in 5.6 and 5.5 – oCERT Advisory

Today, oCERT published advisory 2015-003 describing a TLS vulnerability in MySQL and derivative products.  The content isn’t exactly news – it is documented legacy behavior and the subject of an earlier blog post describing how MySQL Server 5.7 solves the problem.  That said, the efforts of Duo Security are certainly appreciated and welcomed – it provides a meaningful context to discuss how to properly harden existing MySQL 5.5 and 5.6 deployments, as well as frame a discussion on potential changes in these versions to increase security.

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