Obfuscation required for sensitive objects in logs

[dgroup]

Summary

Key	Value
Rule	ObfuscationRequired
Ruleset	io/github/dgroup/arch4u/pmd/arch4u-template-ruleset.xml
Category	Error Prone
Framework	any java logging framework
Since	0.1.0
Incidents in past at my experience	10+
Template	true

Why?

Quite often developers are using logging statements like

public ... ... (Order order) ... {
   log.debug("Order is processed: {}", order)  // where order.getCustomer() may return sensitive/personal data
}

Template ObfuscationRequired allows to specify what exactly objects are not allowed to be placed as arguments to the logging methods:

<rule name="ObfuscationRequired"
      since="0.1.0"
      language="java"
      externalInfoUrl="https://github.com/dgroup/arch4u-pmd/discussions/64"
      message="Sensitive data might be exposed to the logs: https://github.com/dgroup/arch4u-pmd/discussions/64"
      class="io.github.dgroup.arch4u.pmd.ObfuscationRequired">
    <priority>3</priority>
    <properties>
      <property name="loggerClasses" delimiter="|" value="org.slf4j.Logger|java.util.logging.Logger|org.apache.log4j.Logger|org.apache.logging.log4j.Logger"/>
      <property name="sensitiveClasses" value="io.github.dgroup.Person|io.github.dgroup.justpackage"/>
    </properties>
</rule>

and rule will throw the following violation

public class MyClass {
   private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(MyClass.class);
   
   private Func<Person, String> obfuscation = ... ;

   public ... ...(io.github.dgroup.Person person, io.github.dgroup.justpackage.Credentials credentials) ... {
       log.debug("Got {}", person);                          // violation
       log.debug("Got {}", this.obfuscation.apply(person));  // ok                        
       log.debug("Got person with id {}", person.getId());   // ok
       log.debug("Got creds {}", credentials);                          // violation
       log.debug("Got creds {}", this.obfuscation.apply(credentials));  // ok
   }
}