External Authorization (proto)

This extension has the qualified name envoy.filters.http.ext_authz

Note

This extension is intended to be robust against untrusted downstream traffic. It assumes that the upstream is trusted.

Tip

This extension extends and can be used with the following extension category:

This extension must be configured with one of the following type URLs:

External Authorization configuration overview.

extensions.filters.http.ext_authz.v3.ExtAuthz

[extensions.filters.http.ext_authz.v3.ExtAuthz proto]

{
  "grpc_service": {...},
  "http_service": {...},
  "transport_api_version": ...,
  "failure_mode_allow": ...,
  "failure_mode_allow_header_add": ...,
  "with_request_body": {...},
  "clear_route_cache": ...,
  "status_on_error": {...},
  "validate_mutations": ...,
  "metadata_context_namespaces": [],
  "typed_metadata_context_namespaces": [],
  "route_metadata_context_namespaces": [],
  "route_typed_metadata_context_namespaces": [],
  "filter_enabled": {...},
  "filter_enabled_metadata": {...},
  "deny_at_disable": {...},
  "include_peer_certificate": ...,
  "stat_prefix": ...,
  "bootstrap_metadata_labels_key": ...,
  "allowed_headers": {...},
  "disallowed_headers": {...},
  "include_tls_session": ...,
  "charge_cluster_response_stats": {...},
  "encode_raw_headers": ...,
  "decoder_header_mutation_rules": {...}
}
grpc_service

(config.core.v3.GrpcService) gRPC service configuration (default timeout: 200ms).

External authorization service configuration.

Only one of grpc_service, http_service may be set.

http_service

(extensions.filters.http.ext_authz.v3.HttpService) HTTP service configuration (default timeout: 200ms).

External authorization service configuration.

Only one of grpc_service, http_service may be set.

transport_api_version

(config.core.v3.ApiVersion) API version for ext_authz transport protocol. This describes the ext_authz gRPC endpoint and version of messages used on the wire.

failure_mode_allow

(bool) Changes filter’s behaviour on errors:

1. When set to true, the filter will accept client request even if the communication with the authorization service has failed, or if the authorization service has returned a HTTP 5xx error.

2. When set to false, ext-authz will reject client requests and return a Forbidden response if the communication with the authorization service has failed, or if the authorization service has returned a HTTP 5xx error.

Note that errors can be always tracked in the stats.

failure_mode_allow_header_add

(bool) When failure_mode_allow and failure_mode_allow_header_add are both set to true, x-envoy-auth-failure-mode-allowed: true will be added to request headers if the communication with the authorization service has failed, or if the authorization service has returned a HTTP 5xx error.

with_request_body

(extensions.filters.http.ext_authz.v3.BufferSettings) Enables filter to buffer the client request body and send it within the authorization request. A x-envoy-auth-partial-body: false|true metadata header will be added to the authorization request message indicating if the body data is partial.

clear_route_cache

(bool) Clears route cache in order to allow the external authorization service to correctly affect routing decisions. Filter clears all cached routes when:

  1. The field is set to true.

  2. The status returned from the authorization service is a HTTP 200 or gRPC 0.

3. At least one authorization response header is added to the client request, or is used for altering another client request header.

status_on_error

(type.v3.HttpStatus) Sets the HTTP status that is returned to the client when the authorization server returns an error or cannot be reached. The default status is HTTP 403 Forbidden.

validate_mutations

(bool) When this is set to true, the filter will check the ext_authz response for invalid header & query parameter mutations. If the side stream response is invalid, it will send a local reply to the downstream request with status HTTP 500 Internal Server Error.

Note that headers_to_remove & query_parameters_to_remove are validated, but invalid elements in those fields should not affect any headers & thus will not cause the filter to send a local reply.

When set to false, any invalid mutations will be visible to the rest of envoy and may cause unexpected behavior.

If you are using ext_authz with an untrusted ext_authz server, you should set this to true.

metadata_context_namespaces

(repeated string) Specifies a list of metadata namespaces whose values, if present, will be passed to the ext_authz service. The filter_metadata is passed as an opaque protobuf::Struct.

Please note that this field exclusively applies to the gRPC ext_authz service and has no effect on the HTTP service.

For example, if the jwt_authn filter is used and payload_in_metadata is set, then the following will pass the jwt payload to the authorization server.

metadata_context_namespaces:
- envoy.filters.http.jwt_authn
typed_metadata_context_namespaces

(repeated string) Specifies a list of metadata namespaces whose values, if present, will be passed to the ext_authz service. typed_filter_metadata is passed as a protobuf::Any.

Please note that this field exclusively applies to the gRPC ext_authz service and has no effect on the HTTP service.

It works in a way similar to metadata_context_namespaces but allows Envoy and ext_authz server to share the protobuf message definition in order to do a safe parsing.

route_metadata_context_namespaces

(repeated string) Specifies a list of route metadata namespaces whose values, if present, will be passed to the ext_authz service at route_metadata_context in CheckRequest. filter_metadata is passed as an opaque protobuf::Struct.

route_typed_metadata_context_namespaces

(repeated string) Specifies a list of route metadata namespaces whose values, if present, will be passed to the ext_authz service at route_metadata_context in CheckRequest. typed_filter_metadata is passed as an protobuf::Any.

filter_enabled

(config.core.v3.RuntimeFractionalPercent) Specifies if the filter is enabled.

If runtime_key is specified, Envoy will lookup the runtime key to get the percentage of requests to filter.

If this field is not specified, the filter will be enabled for all requests.

filter_enabled_metadata

(type.matcher.v3.MetadataMatcher) Specifies if the filter is enabled with metadata matcher. If this field is not specified, the filter will be enabled for all requests.

deny_at_disable

(config.core.v3.RuntimeFeatureFlag) Specifies whether to deny the requests, when the filter is disabled. If runtime_key is specified, Envoy will lookup the runtime key to determine whether to deny request for filter protected path at filter disabling. If filter is disabled in typed_per_filter_config for the path, requests will not be denied.

If this field is not specified, all requests will be allowed when disabled.

If a request is denied due to this setting, the response code in status_on_error will be returned.

include_peer_certificate

(bool) Specifies if the peer certificate is sent to the external service.

When this field is true, Envoy will include the peer X.509 certificate, if available, in the certificate.

stat_prefix

(string) Optional additional prefix to use when emitting statistics. This allows to distinguish emitted statistics between configured ext_authz filters in an HTTP filter chain. For example:

http_filters:
  - name: envoy.filters.http.ext_authz
    typed_config:
      "@type": type.googleapis.com/envoy.extensions.filters.http.ext_authz.v3.ExtAuthz
      stat_prefix: waf # This emits ext_authz.waf.ok, ext_authz.waf.denied, etc.
  - name: envoy.filters.http.ext_authz
    typed_config:
      "@type": type.googleapis.com/envoy.extensions.filters.http.ext_authz.v3.ExtAuthz
      stat_prefix: blocker # This emits ext_authz.blocker.ok, ext_authz.blocker.denied, etc.
bootstrap_metadata_labels_key

(string) Optional labels that will be passed to labels in destination. The labels will be read from metadata with the specified key.

allowed_headers

(type.matcher.v3.ListStringMatcher) Check request to authorization server will include the client request headers that have a correspondent match in the list. If this option isn’t specified, then all client request headers are included in the check request to a gRPC authorization server, whereas no client request headers (besides the ones allowed by default - see note below) are included in the check request to an HTTP authorization server. This inconsistency between gRPC and HTTP servers is to maintain backwards compatibility with legacy behavior.

Note

  1. For requests to an HTTP authorization server: in addition to the the user’s supplied matchers, Host, Method, Path, Content-Length, and Authorization are additionally included in the list.

Note

2. For requests to an HTTP authorization server: Content-Length will be set to 0 and the request to the authorization server will not have a message body. However, the check request can include the buffered client request body (controlled by with_request_body setting), consequently the value of Content-Length of the authorization request reflects the size of its payload size.

Note

3. This can be overridden by the field disallowed_headers below. That is, if a header matches for both allowed_headers and disallowed_headers, the header will NOT be sent.

disallowed_headers

(type.matcher.v3.ListStringMatcher) If set, specifically disallow any header in this list to be forwarded to the external authentication server. This overrides the above allowed_headers if a header matches both.

include_tls_session

(bool) Specifies if the TLS session level details like SNI are sent to the external service.

When this field is true, Envoy will include the SNI name used for TLSClientHello, if available, in the tls_session.

charge_cluster_response_stats

(BoolValue) Whether to increment cluster statistics (e.g. cluster.<cluster_name>.upstream_rq_*) on authorization failure. Defaults to true.

encode_raw_headers

(bool) Whether to encode the raw headers (i.e. unsanitized values & unconcatenated multi-line headers) in authentication request. Works with both HTTP and GRPC clients.

When this is set to true, header values are not sanitized. Headers with the same key will also not be combined into a single, comma-separated header. Requests to GRPC services will populate the field header_map. Requests to HTTP services will be constructed with the unsanitized header values and preserved multi-line headers with the same key.

If this field is set to false, header values will be sanitized, with any non-UTF-8-compliant bytes replaced with ‘!’. Headers with the same key will have their values concatenated into a single comma-separated header value. Requests to GRPC services will populate the field headers. Requests to HTTP services will have their header values sanitized and will not preserve multi-line headers with the same key.

It’s recommended you set this to true unless you already rely on the old behavior. False is the default only for backwards compatibility.

decoder_header_mutation_rules

(config.common.mutation_rules.v3.HeaderMutationRules) Rules for what modifications an ext_authz server may make to the request headers before continuing decoding / forwarding upstream.

If set to anything, enables header mutation checking against configured rules. Note that HeaderMutationRules has defaults that change ext_authz behavior. Also note that if this field is set to anything, ext_authz can no longer append to :-prefixed headers.

If empty, header mutation rule checking is completely disabled.

Regardless of what is configured here, ext_authz cannot remove :-prefixed headers.

This field and validate_mutations have different use cases. validate_mutations enables correctness checks for all header / query parameter mutations (e.g. for invalid characters). This field allows the filter to reject mutations to specific headers.

extensions.filters.http.ext_authz.v3.BufferSettings

[extensions.filters.http.ext_authz.v3.BufferSettings proto]

Configuration for buffering the request data.

{
  "max_request_bytes": ...,
  "allow_partial_message": ...,
  "pack_as_bytes": ...
}
max_request_bytes

(uint32) Sets the maximum size of a message body that the filter will hold in memory. Envoy will return HTTP 413 and will not initiate the authorization process when buffer reaches the number set in this field. Note that this setting will have precedence over failure_mode_allow.

allow_partial_message

(bool) When this field is true, Envoy will buffer the message until max_request_bytes is reached. The authorization request will be dispatched and no 413 HTTP error will be returned by the filter.

pack_as_bytes

(bool) If true, the body sent to the external authorization service is set with raw bytes, it sets the raw_body field of HTTP request attribute context. Otherwise, body will be filled with UTF-8 string request body.

This field only affects configurations using a grpc_service. In configurations that use an http_service, this has no effect.

extensions.filters.http.ext_authz.v3.HttpService

[extensions.filters.http.ext_authz.v3.HttpService proto]

HttpService is used for raw HTTP communication between the filter and the authorization service. When configured, the filter will parse the client request and use these attributes to call the authorization server. Depending on the response, the filter may reject or accept the client request. Note that in any of these events, metadata can be added, removed or overridden by the filter:

On authorization request, a list of allowed request headers may be supplied. See allowed_headers for details. Additional headers metadata may be added to the authorization request. See headers_to_add for details.

On authorization response status HTTP 200 OK, the filter will allow traffic to the upstream and additional headers metadata may be added to the original client request. See allowed_upstream_headers for details. Additionally, the filter may add additional headers to the client’s response. See allowed_client_headers_on_success for details.

On other authorization response statuses, the filter will not allow traffic. Additional headers metadata as well as body may be added to the client’s response. See allowed_client_headers for details.

{
  "server_uri": {...},
  "path_prefix": ...,
  "authorization_request": {...},
  "authorization_response": {...}
}
server_uri

(config.core.v3.HttpUri) Sets the HTTP server URI which the authorization requests must be sent to.

path_prefix

(string) Sets a prefix to the value of authorization request header Path.

authorization_request

(extensions.filters.http.ext_authz.v3.AuthorizationRequest) Settings used for controlling authorization request metadata.

authorization_response

(extensions.filters.http.ext_authz.v3.AuthorizationResponse) Settings used for controlling authorization response metadata.

extensions.filters.http.ext_authz.v3.AuthorizationRequest

[extensions.filters.http.ext_authz.v3.AuthorizationRequest proto]

{
  "allowed_headers": {...},
  "headers_to_add": []
}
allowed_headers

(type.matcher.v3.ListStringMatcher) Authorization request includes the client request headers that have a correspondent match in the list. This field has been deprecated in favor of allowed_headers.

Note

In addition to the the user’s supplied matchers, Host, Method, Path, Content-Length, and Authorization are automatically included to the list.

Note

By default, Content-Length header is set to 0 and the request to the authorization service has no message body. However, the authorization request may include the buffered client request body (controlled by with_request_body setting) hence the value of its Content-Length reflects the size of its payload size.

headers_to_add

(repeated config.core.v3.HeaderValue) Sets a list of headers that will be included to the request to authorization service. Note that client request of the same key will be overridden.

extensions.filters.http.ext_authz.v3.AuthorizationResponse

[extensions.filters.http.ext_authz.v3.AuthorizationResponse proto]

{
  "allowed_upstream_headers": {...},
  "allowed_upstream_headers_to_append": {...},
  "allowed_client_headers": {...},
  "allowed_client_headers_on_success": {...},
  "dynamic_metadata_from_headers": {...}
}
allowed_upstream_headers

(type.matcher.v3.ListStringMatcher) When this list is set, authorization response headers that have a correspondent match will be added to the original client request. Note that coexistent headers will be overridden.

allowed_upstream_headers_to_append

(type.matcher.v3.ListStringMatcher) When this list is set, authorization response headers that have a correspondent match will be added to the original client request. Note that coexistent headers will be appended.

allowed_client_headers

(type.matcher.v3.ListStringMatcher) When this list is set, authorization response headers that have a correspondent match will be added to the client’s response. Note that when this list is not set, all the authorization response headers, except Authority (Host) will be in the response to the client. When a header is included in this list, Path, Status, Content-Length, WWWAuthenticate and Location are automatically added.

allowed_client_headers_on_success

(type.matcher.v3.ListStringMatcher) When this list is set, authorization response headers that have a correspondent match will be added to the client’s response when the authorization response itself is successful, i.e. not failed or denied. When this list is not set, no additional headers will be added to the client’s response on success.

dynamic_metadata_from_headers

(type.matcher.v3.ListStringMatcher) When this list is set, authorization response headers that have a correspondent match will be emitted as dynamic metadata to be consumed by the next filter. This metadata lives in a namespace specified by the canonical name of extension filter that requires it:

extensions.filters.http.ext_authz.v3.ExtAuthzPerRoute

[extensions.filters.http.ext_authz.v3.ExtAuthzPerRoute proto]

Extra settings on a per virtualhost/route/weighted-cluster level.

{
  "disabled": ...,
  "check_settings": {...}
}
disabled

(bool) Disable the ext auth filter for this particular vhost or route. If disabled is specified in multiple per-filter-configs, the most specific one will be used.

Precisely one of disabled, check_settings must be set.

check_settings

(extensions.filters.http.ext_authz.v3.CheckSettings) Check request settings for this route.

Precisely one of disabled, check_settings must be set.

extensions.filters.http.ext_authz.v3.CheckSettings

[extensions.filters.http.ext_authz.v3.CheckSettings proto]

Extra settings for the check request.

{
  "context_extensions": {...},
  "disable_request_body_buffering": ...,
  "with_request_body": {...}
}
context_extensions

(repeated map<string, string>) Context extensions to set on the CheckRequest’s AttributeContext.context_extensions

You can use this to provide extra context for the external authorization server on specific virtual hosts/routes. For example, adding a context extension on the virtual host level can give the ext-authz server information on what virtual host is used without needing to parse the host header. If CheckSettings is specified in multiple per-filter-configs, they will be merged in order, and the result will be used.

Merge semantics for this field are such that keys from more specific configs override.

Note

These settings are only applied to a filter configured with a grpc_service.

disable_request_body_buffering

(bool) When set to true, disable the configured with_request_body for a specific route.

Please note that only one of disable_request_body_buffering or with_request_body may be specified.

with_request_body

(extensions.filters.http.ext_authz.v3.BufferSettings) Enable or override request body buffering, which is configured using the with_request_body option for a specific route.

Please note that only only one of with_request_body or disable_request_body_buffering may be specified.