feat: commit log secret (#284)

Author: richardhuaaa

proto/mls/api/v1/mls.proto

@@ -4,6 +4,7 @@ package xmtp.mls.api.v1;
 
 import "google/api/annotations.proto";
 import "google/protobuf/empty.proto";
+import "identity/associations/signature.proto";
 import "message_contents/signature.proto";
 import "mls/message_contents/commit_log.proto";
 import "mls/message_contents/wrapper_encryption.proto";
@@ -367,7 +368,8 @@ message BatchPublishCommitLogRequest {
 
 message PublishCommitLogRequest {
   bytes group_id = 1;
-  bytes encrypted_commit_log_entry = 2;
+  bytes serialized_commit_log_entry = 2;
+  xmtp.identity.associations.RecoverableEd25519Signature signature = 3;
 }
 
 message QueryCommitLogRequest {

proto/mls/message_contents/commit_log.proto

@@ -4,6 +4,8 @@ syntax = "proto3";
 
 package xmtp.mls.message_contents;
 
+import "identity/associations/signature.proto";
+
 enum CommitResult {
   COMMIT_RESULT_UNSPECIFIED = 0;
   COMMIT_RESULT_APPLIED = 1;
@@ -31,5 +33,6 @@ message PlaintextCommitLogEntry {
 
 message CommitLogEntry {
   uint64 sequence_id = 1;
-  bytes encrypted_commit_log_entry = 2;
+  bytes serialized_commit_log_entry = 2;
+  xmtp.identity.associations.RecoverableEd25519Signature signature = 3;
 }

proto/mls/message_contents/group_mutable_metadata.proto

@@ -6,15 +6,17 @@ package xmtp.mls.message_contents;
 option go_package = "github.com/xmtp/proto/v3/go/mls/message_contents";
 option java_package = "org.xmtp.proto.mls.message.contents";
 
-
 // Message for group mutable metadata
 message GroupMutableMetadataV1 {
   // Map to store various metadata attributes (Group name, etc.)
-  map<string, string> attributes = 1;  
+  map<string, string> attributes = 1;
   Inboxes admin_list = 2;
   // Creator starts as only super_admin
   // Only super_admin can add/remove other super_admin
   Inboxes super_admin_list = 3;
+  // The ED25519 private key used to sign commit log entries
+  // Must match the first entry in the commit log to be valid
+  optional bytes commit_log_signer = 4;
 }
 
 // Wrapper around a list of repeated Inbox Ids