When debugging an issue where one of our server components was unable to communicate with other components via SSL, we realized that LdapGroupsMapping sets its SSL configurations globally, rather than scoping them to the HTTP clients it creates.
Notice the System.setProperty() calls, which will change settings JVM-wide. This causes issues for other SSL clients, which may rely on the default JVM truststore being used. This behavior was initially introduced by
HADOOP-8121, and extended to include the truststore configurations in HADOOP-12862.
The correct approach is to use a mechanism which is scoped to the LDAP requests only. The right approach appears to be to use the java.naming.ldap.factory.socket parameter to set the socket factory to a custom SSL socket factory which correctly sets the key and trust store parameters. See an example here.