sds: support generic type secret (#9858)

Description:
This PR adds support of generic secret type in secret manager. The goal is to enable filters to access generic secret.

Risk Level: Medium
Testing: Unit test, Integration test
Docs Changes: Changed
Release Notes: Changed

Signed-off-by: bennettdong <xiangfeid@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ f64ade1d90d9209982008391f337ed76e7aca3d2

envoy/api/v2/auth/cert.proto

@@ -435,6 +435,11 @@ message DownstreamTlsContext {
   }];
 }
 
+message GenericSecret {
+  // Secret of generic type and is available to filters.
+  core.DataSource secret = 1 [(udpa.annotations.sensitive) = true];
+}
+
 message SdsSecretConfig {
   // Name (FQDN, UUID, SPKI, SHA256, etc.) by which the secret can be uniquely referred to.
   // When both name and config are specified, then secret can be fetched and/or reloaded via
@@ -444,6 +449,7 @@ message SdsSecretConfig {
   core.ConfigSource sds_config = 2;
 }
 
+// [#next-free-field: 6]
 message Secret {
   // Name (FQDN, UUID, SPKI, SHA256, etc.) by which the secret can be uniquely referred to.
   string name = 1;
@@ -454,5 +460,7 @@ message Secret {
     TlsSessionTicketKeys session_ticket_keys = 3;
 
     CertificateValidationContext validation_context = 4;
+
+    GenericSecret generic_secret = 5;
   }
 }

envoy/extensions/transport_sockets/tls/v3/cert.proto

@@ -453,6 +453,13 @@ message DownstreamTlsContext {
   }];
 }
 
+message GenericSecret {
+  option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.auth.GenericSecret";
+
+  // Secret of generic type and is available to filters.
+  config.core.v3.DataSource secret = 1 [(udpa.annotations.sensitive) = true];
+}
+
 message SdsSecretConfig {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.auth.SdsSecretConfig";
 
@@ -464,6 +471,7 @@ message SdsSecretConfig {
   config.core.v3.ConfigSource sds_config = 2;
 }
 
+// [#next-free-field: 6]
 message Secret {
   option (udpa.annotations.versioning).previous_message_type = "envoy.api.v2.auth.Secret";
 
@@ -476,5 +484,7 @@ message Secret {
     TlsSessionTicketKeys session_ticket_keys = 3;
 
     CertificateValidationContext validation_context = 4;
+
+    GenericSecret generic_secret = 5;
   }
 }