Add x.509 certificate subject as an authorized user. To authenticate with a client certificate, first add the value of the subject from the client certificate as a MongoDB user. Each unique x.509 client certificate corresponds to a single MongoDB user; meaning a single client certificate cannot authenticate more than one MongoDB user. Note: The RDNs in the subject string must be compatible with the RFC2253 standard. Retrieve the RFC2253 formatted subject from the client certificate with the following command: $ openssl x509 -in <pathToClient PEM> -inform PEM -subject -nameopt RFC2253 The command returns the subject string as well as certificate: subject= CN=myName,OU=myOrgUnit,O=myOrg,L=myLocality,ST=myState,C=myCountry -----BEGIN CERTIFICATE----- # ... -----END CERTIFICATE----- Add the RFC2253 compliant value of the subject as a user. Omit spaces as needed. For example, in the mongo shell, to add the user with both the "readWrite" role in the test database and the "userAdminAnyDatabase" role, which is defined only in the admin database: > db.getSiblingDB("$external").runCommand( { createUser: "CN=myName,OU=myOrgUnit,O=myOrg,L=myLocality,ST=myState,C=myCountry", roles: [ { role: 'readWrite', db: 'test' }, { role: 'userAdminAnyDatabase', db: 'admin' } ], writeConcern: { w: "majority" , wtimeout: 5000 } } ) In the above example, to add the user with the "readWrite" role in the test database, the role specification document specified "test" in the "db" field. To add "userAdminAnyDatabase" role for the user, the above example specified "admin" in the "db" field. Note: Some roles are defined only in the admin database, including clusterAdmin, readAnyDatabase, readWriteAnyDatabase, dbAdminAnyDatabase, and userAdminAnyDatabase. To add a user with these roles, specify "admin" in the "db" field. Refer to Manage Users and Roles for details on adding a user with roles. To remove a user that is not authorized, run the following command: > use $external > db.dropUser("<RDN of user>")