Client Security:
Erlang

This tutorial shows you how to set up a Riak Erlang client to authenticate itself when connecting to Riak.

If you are using trust, PAM-, you can use the security setup described below. Password-based authentication is covered in a later section. If you are using certificate-based authentication, follow the instructions in the section below.

Note on certificate generation
This tutorial does not cover certificate generation. It assumes that all necessary certificates have already been created and are stored in a directory called `/ssl_dir`. This directory name is used only for example purposes.

Erlang Client Basics

When connecting to Riak using an Erlang-based client, you typically use a process identifier to refer to the client connection. The following example creates a process identifier (we’ll call it Pid) for a connection to localhost on port 8087:

{ok, Pid} = riakc_pb_socket:start("127.0.0.1", 8087).

If you are using Riak security, all connecting clients should have access to the same Certificate Authority (CA) used on the server side, regardless of which security source you choose. In addition, all clients should provide a username. The example above created a connection to Riak without specifying a username or CA. That information is specified as a list of options passed to the start function. We’ll specify those options in a list called SecurityOptions.

CertDir = "/ssl_dir",
SecurityOptions = [
                   {credentials, "riakuser", ""},
                   {cacertfile, filename:join([CertDir, "cacertfile.pem"])}
                  ],
{ok, Pid} = riakc_pb_socket:start("127.0.0.1", 8087, SecurityOptions).

Please note that you do not need to specify a password if you are not using password-based authentication. If you are using a different security source, Riak will ignore the password. You can enter an empty string (as in the example above) or anything you’d like.

This client is not currently set up to use any of the available security sources, with the exception of trust-based authentication, provided that the CIDR from which the client is connecting has been specified as trusted. More on specifying trusted CIDRs can be found in Trust-based Authentication.

Password-based Authentication

To enable our client to use password-based auth, we can use most of the information from the example above, with the exception that we’ll also specify a password for the client in the SecurityOptions list from above. We’ll use the password rosebud here and in the rest of the examples.

CertDir = "/ssl_dir",
SecurityOptions = [
                   {credentials, "riakuser", "rosebud"},
                   {cacertfile, filename:join([CertDir, "cacertfile.pem"])}
                  ],
{ok, Pid} = riakc_pb_socket:start("127.0.0.1", 8087, SecurityOptions).

PAM-based Authentication

If you have specified that a specific client be authenticated using PAM, you will need to provide a CA as well as the username and password that you specified when creating the user in Riak. For more, see our documentation on User Management.

Certificate-based Authentication

Using certificate-based authentication requires us to specify the location of a general CA (as with all security sources), a username, a CA-generated cert, and a private key. We’ll assume that all certs are stored in /ssl_dir, as in the previous examples.

CertDir = "/ssl_dir",
SecurityOptions = [
                   {credentials, "riakuser", "rosebud"},
                   {cacertfile, filename:join([CertDir, "cacertfile.pem"])},
                   {certfile, filename:join([CertDir, "cert.pem"])},
                   {keyfile, filename:join([CertDir, "key.pem"])}
                  ],
{ok, Pid} = riakc_pb_socket:start("127.0.0.1", 8087, SecurityOptions).