// Copyright 2018 Istio Authors
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

syntax = "proto3";

// $title: Authentication Policy
// $description: Authentication policy for Istio services.
// $location: https://istio.io/docs/reference/config/security/istio.authentication.v1alpha1.html
// $weight: 10
// $aliases: [/docs/reference/config/istio.authentication.v1alpha1.html]

// This package defines user-facing authentication policy.
package istio.authentication.v1alpha1;

import "google/api/field_behavior.proto";

option go_package = "istio.io/api/authentication/v1alpha1";

// Describes how to match a given string. Match is case-sensitive.
message StringMatch {
  oneof match_type {
    // exact string match.
    string exact = 1;

    // prefix-based match.
    string prefix = 2;

    // suffix-based match.
    string suffix = 3;

    // ECMAscript style regex-based match as defined by [EDCA-262](http://en.cppreference.com/w/cpp/regex/ecmascript).
    // Example: "^/pets/(.*?)?"
    string regex = 4;
  }
}

// TLS authentication params.
message MutualTls {
  // Defines the acceptable connection TLS mode.
  enum Mode {
    // Client cert must be presented, connection is in TLS.
    STRICT = 0;

    // Connection can be either plaintext or TLS, and client cert can be omitted.
    PERMISSIVE = 1;
  };

  // WILL BE DEPRECATED, if set, will translates to `TLS_PERMISSIVE` mode.
  // Set this flag to true to allow regular TLS (i.e without client x509
  // certificate). If request carries client certificate, identity will be
  // extracted and used (set to peer identity). Otherwise, peer identity will
  // be left unset.
  // When the flag is false (default), request must have client certificate.
  bool allow_tls = 1;

  // Defines the mode of mTLS authentication.
  Mode mode = 2;
}

// JSON Web Token (JWT) token format for authentication as defined by
// [RFC 7519](https://tools.ietf.org/html/rfc7519). See [OAuth 2.0](https://tools.ietf.org/html/rfc6749) and
// [OIDC 1.0](http://openid.net/connect) for how this is used in the whole
// authentication flow.
//
// For example:
//
// A JWT for any requests:
//
// ```yaml
// issuer: https://example.com
// audiences:
// - bookstore_android.apps.googleusercontent.com
//   bookstore_web.apps.googleusercontent.com
// jwksUri: https://example.com/.well-known/jwks.json
// ```
//
// A JWT for all requests except request at path `/health_check` and path with
// prefix `/status/`. This is useful to expose some paths for public access but
// keep others JWT validated.
//
// ```yaml
// issuer: https://example.com
// jwksUri: https://example.com/.well-known/jwks.json
// triggerRules:
// - excludedPaths:
//   - exact: /health_check
//   - prefix: /status/
// ```
//
// A JWT only for requests at path `/admin`. This is useful to only require JWT
// validation on a specific set of paths but keep others public accessible.
//
// ```yaml
// issuer: https://example.com
// jwksUri: https://example.com/.well-known/jwks.json
// triggerRules:
// - includedPaths:
//   - prefix: /admin
// ```
//
// A JWT only for requests at path of prefix `/status/` but except the path of
// `/status/version`. This means for any request path with prefix `/status/` except
// `/status/version` will require a valid JWT to proceed.
//
// ```yaml
// issuer: https://example.com
// jwksUri: https://example.com/.well-known/jwks.json
// triggerRules:
// - excludedPaths:
//   - exact: /status/version
//   includedPaths:
//   - prefix: /status/
// ```
message Jwt {
  // Identifies the issuer that issued the JWT. See
  // [issuer](https://tools.ietf.org/html/rfc7519#section-4.1.1)
  // Usually a URL or an email address.
  //
  // Example: https://securetoken.google.com
  // Example: 1234567-compute@developer.gserviceaccount.com
  string issuer = 1;

  // The list of JWT
  // [audiences](https://tools.ietf.org/html/rfc7519#section-4.1.3).
  // that are allowed to access. A JWT containing any of these
  // audiences will be accepted.
  //
  // The service name will be accepted if audiences is empty.
  //
  // Example:
  //
  // ```yaml
  // audiences:
  // - bookstore_android.apps.googleusercontent.com
  //   bookstore_web.apps.googleusercontent.com
  // ```
  repeated string audiences = 2;

  // URL of the provider's public key set to validate signature of the
  // JWT. See [OpenID Discovery](https://openid.net/specs/openid-connect-discovery-1_0.html#ProviderMetadata).
  //
  // Optional if the key set document can either (a) be retrieved from
  // [OpenID
  // Discovery](https://openid.net/specs/openid-connect-discovery-1_0.html) of
  // the issuer or (b) inferred from the email domain of the issuer (e.g. a
  // Google service account).
  //
  // Example: `https://www.googleapis.com/oauth2/v1/certs`
  //
  // Note: Only one of jwks_uri and jwks should be used.
  string jwks_uri = 3;

  // JSON Web Key Set of public keys to validate signature of the JWT.
  // See https://auth0.com/docs/jwks.
  //
  // Note: Only one of jwks_uri and jwks should be used.
  string jwks = 10;

  // Two fields below define where to extract the JWT from an HTTP request.
  //
  // If no explicit location is specified the following default
  // locations are tried in order:
  //
  //     1) The Authorization header using the Bearer schema,
  //        e.g. Authorization: Bearer <token>. (see
  //        [Authorization Request Header
  //        Field](https://tools.ietf.org/html/rfc6750#section-2.1))
  //
  //     2) `access_token` query parameter (see
  //     [URI Query Parameter](https://tools.ietf.org/html/rfc6750#section-2.3))

  // JWT is sent in a request header. `header` represents the
  // header name.
  //
  // For example, if `header=x-goog-iap-jwt-assertion`, the header
  // format will be `x-goog-iap-jwt-assertion: <JWT>`.
  repeated string jwt_headers = 6;

  // JWT is sent in a query parameter. `query` represents the
  // query parameter name.
  //
  // For example, `query=jwt_token`.
  repeated string jwt_params = 7;

  // Trigger rule to match against a request. The trigger rule is satisfied if
  // and only if both rules, excluded_paths and include_paths are satisfied.
  message TriggerRule {
    // List of paths to be excluded from the request. The rule is satisfied if
    // request path does not match to any of the path in this list.
    repeated StringMatch excluded_paths = 1;

    // List of paths that the request must include. If the list is not empty, the
    // rule is satisfied if request path matches at least one of the path in the list.
    // If the list is empty, the rule is ignored, in other words the rule is always satisfied.
    repeated StringMatch included_paths = 2;
  }

  // List of trigger rules to decide if this JWT should be used to validate the
  // request. The JWT validation happens if any one of the rules matched.
  // If the list is not empty and none of the rules matched, authentication will
  // skip the JWT validation.
  // Leave this empty to always trigger the JWT validation.
  repeated TriggerRule trigger_rules = 9;

  // $hide_from_docs
  // Next available field number: 11
}

// PeerAuthenticationMethod defines one particular type of authentication, e.g
// mutual TLS, JWT etc, (no authentication is one type by itself) that can
// be used for peer authentication.
// The type can be progammatically determine by checking the type of the
// "params" field.
message PeerAuthenticationMethod {
  oneof params {
    // Set if mTLS is used.
    MutualTls mtls = 1;

    // $hide_from_docs
    // Set if JWT is used. This option is not yet available.
    Jwt jwt = 2;
  }
}

// OriginAuthenticationMethod defines authentication method/params for origin
// authentication. Origin could be end-user, device, delegate service etc.
// Currently, only JWT is supported for origin authentication.
message OriginAuthenticationMethod {
  // Jwt params for the method.
  Jwt jwt = 1;
}

// Associates authentication with request principal.
enum PrincipalBinding {
  // Principal will be set to the identity from peer authentication.
  USE_PEER = 0;

  // Principal will be set to the identity from origin authentication.
  USE_ORIGIN = 1;
}

// Policy defines what authentication methods can be accepted on workload(s),
// and if authenticated, which method/certificate will set the request principal
// (i.e request.auth.principal attribute).
//
// Authentication policy is composed of 2-part authentication:
// - peer: verify caller service credentials. This part will set source.user
// (peer identity).
// - origin: verify the origin credentials. This part will set request.auth.user
// (origin identity), as well as other attributes like request.auth.presenter,
// request.auth.audiences and raw claims. Note that the identity could be
// end-user, service account, device etc.
//
// Last but not least, the principal binding rule defines which identity (peer
// or origin) should be used as principal. By default, it uses peer.
//
// Examples:
//
// Policy to enable mTLS for all services in namespace frod. The policy name must be
// `default`, and it contains no rule for `targets`.
//
// ```yaml
// apiVersion: authentication.istio.io/v1alpha1
// kind: Policy
// metadata:
//   name: default
//   namespace: frod
// spec:
//   peers:
//   - mtls:
// ```
// Policy to disable mTLS for "productpage" service
//
// ```yaml
// apiVersion: authentication.istio.io/v1alpha1
// kind: Policy
// metadata:
//   name: productpage-mTLS-disable
//   namespace: frod
// spec:
//   targets:
//   - name: productpage
// ```
// Policy to require mTLS for peer authentication, and JWT for origin authentication
// for productpage:9000 except the path '/health_check' . Principal is set from origin identity.
//
// ```yaml
// apiVersion: authentication.istio.io/v1alpha1
// kind: Policy
// metadata:
//   name: productpage-mTLS-with-JWT
//   namespace: frod
// spec:
//   targets:
//   - name: productpage
//     ports:
//     - number: 9000
//   peers:
//   - mtls:
//   origins:
//   - jwt:
//       issuer: "https://securetoken.google.com"
//       audiences:
//       - "productpage"
//       jwksUri: "https://www.googleapis.com/oauth2/v1/certs"
//       jwtHeaders:
//       - "x-goog-iap-jwt-assertion"
//       triggerRules:
//       - excludedPaths:
//         - exact: /health_check
//   principalBinding: USE_ORIGIN
// ```
//
// <!-- go code generation tags
// +kubetype-gen
// +kubetype-gen:groupVersion=authentication.istio.io/v1alpha1
// +kubetype-gen:kubeType=Policy
// +kubetype-gen:kubeType=MeshPolicy
// +kubetype-gen:MeshPolicy:tag=genclient:nonNamespaced
// +genclient
// +k8s:deepcopy-gen=true
// -->
message Policy {
  // List rules to select workloads that the policy should be applied on.
  // If empty, policy will be used on all workloads in the same namespace.
  repeated TargetSelector targets = 1;

  // List of authentication methods that can be used for peer authentication.
  // They will be evaluated in order; the first validate one will be used to
  // set peer identity (source.user) and other peer attributes. If none of
  // these methods pass, request will be rejected with authentication failed error (401).
  // Leave the list empty if peer authentication is not required
  repeated PeerAuthenticationMethod peers = 2;

  // Set this flag to true to accept request (for peer authentication perspective),
  // even when none of the peer authentication methods defined above satisfied.
  // Typically, this is used to delay the rejection decision to next layer (e.g
  // authorization).
  // This flag is ignored if no authentication defined for peer (peers field is empty).
  bool peer_is_optional = 3;

  // List of authentication methods that can be used for origin authentication.
  // Similar to peers, these will be evaluated in order; the first validate one
  // will be used to set origin identity and attributes (i.e request.auth.user,
  // request.auth.issuer etc). If none of these methods pass, request will be
  // rejected with authentication failed error (401).
  // A method may be skipped, depends on its trigger rule. If all of these methods
  // are skipped, origin authentication will be ignored, as if it is not defined.
  // Leave the list empty if origin authentication is not required.
  repeated OriginAuthenticationMethod origins = 4;

  // Set this flag to true to accept request (for origin authentication perspective),
  // even when none of the origin authentication methods defined above satisfied.
  // Typically, this is used to delay the rejection decision to next layer (e.g
  // authorization).
  // This flag is ignored if no authentication defined for origin (origins field is empty).
  bool origin_is_optional = 5;

  // Define whether peer or origin identity should be use for principal. Default
  // value is USE_PEER.
  // If peer (or origin) identity is not available, either because of peer/origin
  // authentication is not defined, or failed, principal will be left unset.
  // In other words, binding rule does not affect the decision to accept or
  // reject request.
  PrincipalBinding principal_binding = 6;
}

// TargetSelector defines a matching rule to a workload. A workload is selected
// if it is associated with the service name and service port(s) specified in the selector rule.
message TargetSelector {
  // The name must be a short name from the service registry. The
  // fully qualified domain name will be resolved in a platform specific manner.
  string name = 1 [(google.api.field_behavior) = REQUIRED];

  // $hide_from_docs
  // $not-implemented-hide
  // Select workload by labels.
  // Once implemented, this is the preferred way rather than using the service name.
  map<string, string> labels = 3;

  // Specifies the ports. Note that this is the port(s) exposed by the service, not workload instance ports.
  // For example, if a service is defined as below, then `8000` should be used, not `9000`.
  // ```yaml
  // kind: Service
  // metadata:
  //   ...
  // spec:
  //   ports:
  //   - name: http
  //     port: 8000
  //     targetPort: 9000
  //   selector:
  //     app: backend
  // ```
  //Leave empty to match all ports that are exposed.
  repeated PortSelector ports = 2;
}

// PortSelector specifies the name or number of a port to be used for
// matching targets for authentication policy. This is copied from
// networking API to avoid dependency.
message PortSelector {
  oneof port {
    // Valid port number
    uint32 number = 1;
    // Port name
    string name = 2;
  }
}
