This topic describes security considerations that are specific to developing, deploying, and running applications that use the Microsoft Drivers for PHP for SQL Server. For more detailed information about SQL Server security, see Data security and compliance.
Connect Using Windows Authentication
Windows Authentication should be used to connect to SQL Server whenever possible for the following reasons:
No credentials are passed over the network during authentication. User names and passwords are not embedded in the database connection string. This means that malicious users or attackers cannot obtain the credentials by monitoring the network or by viewing connection strings inside configuration files.
Users are subject to centralized account management. Security policies such as password expiration periods, minimum password lengths, and account lockout after multiple invalid logon requests are enforced.
For information about how to connect to a server with Windows Authentication, see How to: Connect using Windows Authentication.
When you connect using Windows Authentication, it is recommended that you configure your environment so that SQL Server can use the Kerberos authentication protocol. For more information, see How to make sure that you are using Kerberos authentication when you create a remote connection to an instance of SQL Server 2005 or Kerberos Authentication and SQL Server.
Use Encrypted Connections when Transferring Sensitive Data
Encrypted connections should be used whenever sensitive data is being sent to or retrieved from SQL Server. For information about how to enable encrypted connections, see How to Enable Encrypted Connections to the Database Engine (SQL Server Configuration Manager). To establish a secure connection with the Microsoft Drivers for PHP for SQL Server, use the Encrypt connection attribute when connecting to the server. For more information about connection attributes, see Connection Options.
Use Parameterized Queries
Use parameterized queries to reduce the risk of SQL injection attacks. For examples of executing parameterized queries, see How to: Perform Parameterized Queries.
For more information about SQL injection attacks and related security considerations, see SQL Injection.
Do Not Accept Server or Connection String Information from End Users
Write applications so that end users cannot submit server or connection string information to the application. Maintaining strict control over server and connection string information reduces the surface area for malicious activity.
Turn WarningsAsErrors On During Application Development
Develop applications with the WarningsAsErrors setting set to true so that warnings issued by the driver will be treated as errors. This will allow you to address warnings before you deploy your application. For more information, see Handling Errors and Warnings.
Secure Logs for Deployed Application
For deployed applications, make sure that logs are written to a secure location or that logging is turned off. This helps protect against the possibility of end-users accessing information that has been written to the log files. For more information, see Logging Activity.