feat: add legacy v2-signed keys

proto/mls/message_contents/association.proto

@@ -3,6 +3,8 @@ syntax = "proto3";
 
 package xmtp.mls.message_contents;
 
+import "message_contents/public_key.proto";
+
 option go_package = "github.com/xmtp/proto/v3/go/mls/message_contents";
 option java_package = "org.xmtp.proto.mls.message.contents";
 
@@ -21,6 +23,14 @@ message Eip191Association {
   string iso8601_time = 4;
 }
 
+// LegacyCreateIdentityAssociation is used when a v3 installation key
+// is signed by a v2 identity key, which in turn is signed via a
+// 'CreateIdentity' wallet signature
+message LegacyCreateIdentityAssociation {
+  RecoverableEcdsaSignature signature = 1;
+  xmtp.message_contents.SignedPublicKey signed_legacy_create_identity_key = 2;
+}
+
 // RecoverableEcdsaSignature
 message RecoverableEcdsaSignature {
   // Includes recovery id as the last byte

proto/mls/message_contents/credential.proto

@@ -13,13 +13,17 @@ message MlsCredential {
   bytes installation_public_key = 1;
   oneof association {
     Eip191Association eip_191 = 2;
+    LegacyCreateIdentityAssociation legacy_create_identity = 3;
   }
 }
 
 // A declaration and proof that a credential is no longer valid
 message CredentialRevocation {
-  bytes installation_public_key = 1;
+  oneof public_key {
+    bytes installation_key = 1;
+    bytes unsigned_legacy_create_identity_key = 2;
+  }
   oneof association {
-    Eip191Association eip_191 = 2;
+    Eip191Association eip_191 = 3;
   }
 }