Configure exposed credentials checks using Terraform

The following Terraform configuration example addresses a common use case of exposed credentials checks.

For more information, refer to the Terraform Cloudflare provider documentation ↗︎.

If you are using the Cloudflare API, refer to Configure exposed credentials checks via API.

Add a custom rule to check for exposed credentials

The following configuration creates a custom ruleset with a single rule that checks for exposed credentials.

You can only add exposed credential checks to rules in a custom ruleset (that is, a ruleset with kind = "custom").

resource "cloudflare_ruleset" "account_firewall_custom_ruleset_exposed_creds" {
  account_id  = "<ACCOUNT_ID>"
  name        = "Custom ruleset checking for exposed credentials"
  description = ""
  kind        = "custom"
  phase       = "http_request_firewall_custom"

  rules {
    ref         = "check_for_exposed_creds_add_header"
    description = "Add header when there is a rule match and exposed credentials are detected"
    expression  = "http.request.method == \"POST\" && http.request.uri == \"/login.php\""
    action      = "rewrite"
    action_parameters {
      headers {
        name      = "Exposed-Credential-Check"
        operation = "set"
        value     = "1"
      }
    }
    exposed_credential_check {
      username_expression = "url_decode(http.request.body.form[\"username\"][0])"
      password_expression = "url_decode(http.request.body.form[\"password\"][0])"
    }
  }
}

To create another rule, add a new rules object to the same cloudflare_ruleset resource.

The following configuration deploys the custom ruleset. It defines a dependency on the account_firewall_custom_ruleset_exposed_creds resource and obtains the ID of the created custom ruleset:

resource "cloudflare_ruleset" "account_firewall_custom_entrypoint" {
  account_id  = "<ACCOUNT_ID>"
  name        = "Account-level entry point ruleset for the http_request_firewall_custom phase deploying a custom ruleset checking for exposed credentials"
  description = ""
  kind        = "root"
  phase       = "http_request_firewall_custom"

  depends_on = [cloudflare_ruleset.account_firewall_custom_ruleset_exposed_creds]

  rules {
    ref         = "deploy_custom_ruleset_example_com"
    description = "Deploy custom ruleset for example.com"
    expression  = "(cf.zone.name eq \"example.com\")"
    action      = "execute"
    action_parameters {
      id = cloudflare_ruleset.account_firewall_custom_ruleset_exposed_creds.id
    }
  }
}

More resources

For additional Terraform configuration examples, refer to WAF custom rules configuration using Terraform.