syntax = "proto3";

import "validate/validate.proto";
import "envoy/api/v2/core/address.proto";
import "envoy/api/v2/route/route.proto";
import "envoy/type/matcher/metadata.proto";

package envoy.config.rbac.v2alpha;
option go_package = "v2alpha";

// [#protodoc-title: Role Based Access Control (RBAC)]

// Role Based Access Control (RBAC) provides service-level and method-level access control for a
// service. RBAC policies are additive. The policies are examined in order. A request is allowed
// once a matching policy is found (suppose the `action` is ALLOW).
//
// Here is an example of RBAC configuration. It has two policies:
//
// * Service account "cluster.local/ns/default/sa/admin" has full access (empty permission entry
//   means full access) to the service.
//
// * Any user (empty principal entry means any user) can read ("GET") the service at paths with
//   prefix "/products" or suffix "/reviews" when request header "version" set to either "v1" or
//   "v2".
//
//  .. code-block:: yaml
//
//   action: ALLOW
//   policies:
//     "service-admin":
//       permissions:
//         - any: true
//       principals:
//         - authenticated: { name: "cluster.local/ns/default/sa/admin" }
//         - authenticated: { name: "cluster.local/ns/default/sa/superuser" }
//     "product-viewer":
//       permissions:
//           - and_rules:
//               rules:
//                 - header: { name: ":method", exact_match: "GET" }
//                 - header: { name: ":path", regex_match: "/products(/.*)?" }
//                 - or_rules:
//                     rules:
//                       - destination_port: 80
//                       - destination_port: 443
//       principals:
//         - any: true
//
message RBAC {
  // Should we do safe-list or block-list style access control?
  enum Action {
    // The policies grant access to principals. The rest is denied. This is safe-list style
    // access control. This is the default type.
    ALLOW = 0;

    // The policies deny access to principals. The rest is allowed. This is block-list style
    // access control.
    DENY = 1;
  }

  // The action to take if a policy matches. The request is allowed if and only if:
  //
  //   * `action` is "ALLOWED" and at least one policy matches
  //   * `action` is "DENY" and none of the policies match
  Action action = 1;

  // Maps from policy name to policy. A match occurs when at least one policy matches the request.
  map<string, Policy> policies = 2;
}

// Policy specifies a role and the principals that are assigned/denied the role. A policy matches if
// and only if at least one of its permissions match the action taking place AND at least one of its
// principals match the downstream.
message Policy {
  // Required. The set of permissions that define a role. Each permission is matched with OR
  // semantics. To match all actions for this policy, a single Permission with the `any` field set
  // to true should be used.
  repeated Permission permissions = 1 [(validate.rules).repeated .min_items = 1];

  // Required. The set of principals that are assigned/denied the role based on “action”. Each
  // principal is matched with OR semantics. To match all downstreams for this policy, a single
  // Principal with the `any` field set to true should be used.
  repeated Principal principals = 2 [(validate.rules).repeated .min_items = 1];
}

// Permission defines an action (or actions) that a principal can take.
message Permission {

  // Used in the `and_rules` and `or_rules` fields in the `rule` oneof. Depending on the context,
  // each are applied with the associated behavior.
  message Set {
    repeated Permission rules = 1 [(validate.rules).repeated .min_items = 1];
  }

  oneof rule {
    option (validate.required) = true;

    // A set of rules that all must match in order to define the action.
    Set and_rules = 1;

    // A set of rules where at least one must match in order to define the action.
    Set or_rules = 2;

    // When any is set, it matches any action.
    bool any = 3 [(validate.rules).bool.const = true];

    // A header (or psuedo-header such as :path or :method) on the incoming HTTP request.
    envoy.api.v2.route.HeaderMatcher header = 4;

    // A CIDR block that describes the destination IP.
    envoy.api.v2.core.CidrRange destination_ip = 5;

    // A port number that describes the destination port connecting to.
    uint32 destination_port = 6 [(validate.rules).uint32.lte = 65535];

    // Metadata that describes additional information about the action.
    envoy.type.matcher.MetadataMatcher metadata = 7;
  }
}

// Principal defines an identity or a group of identities for a downstream subject.
message Principal {

  // Used in the `and_ids` and `or_ids` fields in the `identifier` oneof. Depending on the context,
  // each are applied with the associated behavior.
  message Set {
    repeated Principal ids = 1 [(validate.rules).repeated .min_items = 1];
  }

  // Authentication attributes for a downstream.
  message Authenticated {
    // The name of the principal. If set, the URI SAN is used from the certificate, otherwise the
    // subject field is used. If unset, it applies to any user that is authenticated.
    string name = 1;
  }

  oneof identifier {
    option (validate.required) = true;

    // A set of identifiers that all must match in order to define the downstream.
    Set and_ids = 1;

    // A set of identifiers at least one must match in order to define the downstream.
    Set or_ids = 2;

    // When any is set, it matches any downstream.
    bool any = 3 [(validate.rules).bool.const = true];

    // Authenticated attributes that identify the downstream.
    Authenticated authenticated = 4;

    // A CIDR block that describes the downstream IP.
    envoy.api.v2.core.CidrRange source_ip = 5;

    // A header (or psuedo-header such as :path or :method) on the incoming HTTP request.
    envoy.api.v2.route.HeaderMatcher header = 6;

    // Metadata that describes additional information about the principal.
    envoy.type.matcher.MetadataMatcher metadata = 7;
  }
}