From f4e46b23f64f7b1eb7d16abcc7e9ad90445bfa59 Mon Sep 17 00:00:00 2001
From: Paul Steckler <steck@stecksoft.com>
Date: Thu, 8 Dec 2022 16:48:51 -0800
Subject: [PATCH] Limit length of zkapp URIs

---
 .../lib/genesis_ledger_helper_lib.ml          |  9 +++-
 src/lib/mina_base/zkapp_account.ml            | 54 +++++++++++++++++--
 2 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/src/lib/genesis_ledger_helper/lib/genesis_ledger_helper_lib.ml b/src/lib/genesis_ledger_helper/lib/genesis_ledger_helper_lib.ml
index b428434b2fd..a1bc49493aa 100644
--- a/src/lib/genesis_ledger_helper/lib/genesis_ledger_helper_lib.ml
+++ b/src/lib/genesis_ledger_helper/lib/genesis_ledger_helper_lib.ml
@@ -121,6 +121,13 @@ module Accounts = struct
             ; proved_state
             ; zkapp_uri
             } ->
+            let%bind () =
+              let zkapp_uri_length = String.length zkapp_uri in
+              if zkapp_uri_length > Zkapp_account.Zkapp_uri.max_length then
+                Or_error.errorf "zkApp URI \"%s\" exceeds max length: %d > %d"
+                  zkapp_uri zkapp_uri_length Zkapp_account.Zkapp_uri.max_length
+              else Or_error.return ()
+            in
             let%bind app_state =
               if
                 Mina_stdlib.List.Length.Compare.(
@@ -145,7 +152,7 @@ module Accounts = struct
               then Ok (Pickles_types.Vector.Vector_5.of_list_exn sequence_state)
               else
                 Or_error.errorf
-                  !"Snap account sequence_state has invalid length %{sexp: \
+                  !"zkApp account sequence_state has invalid length %{sexp: \
                     Runtime_config.Accounts.Single.t} length: %d"
                   t
                   (List.length sequence_state)
diff --git a/src/lib/mina_base/zkapp_account.ml b/src/lib/mina_base/zkapp_account.ml
index 817b2e909a1..41acea7bbfe 100644
--- a/src/lib/mina_base/zkapp_account.ml
+++ b/src/lib/mina_base/zkapp_account.ml
@@ -181,6 +181,52 @@ module Sequence_events = struct
   [%%endif]
 end
 
+module Zkapp_uri = struct
+  [%%versioned_binable
+  module Stable = struct
+    module V1 = struct
+      module T = struct
+        type t = string [@@deriving sexp, equal, compare, hash, yojson]
+
+        let to_latest = Fn.id
+
+        let max_length = 255
+
+        let check (x : t) = assert (String.length x <= max_length)
+
+        let t_of_sexp sexp =
+          let res = t_of_sexp sexp in
+          check res ; res
+
+        let of_yojson json =
+          let res = of_yojson json in
+          Result.bind res ~f:(fun res ->
+              Result.try_with (fun () -> check res)
+              |> Result.map ~f:(Fn.const res)
+              |> Result.map_error
+                   ~f:(Fn.const "Zkapp_uri.of_yojson: symbol is too long") )
+      end
+
+      include T
+
+      include
+        Binable.Of_binable_without_uuid
+          (Core_kernel.String.Stable.V1)
+          (struct
+            type t = string
+
+            let to_binable = Fn.id
+
+            let of_binable x = check x ; x
+          end)
+    end
+  end]
+
+  [%%define_locally
+  Stable.Latest.
+    (sexp_of_t, t_of_sexp, equal, to_yojson, of_yojson, max_length, check)]
+end
+
 module Poly = struct
   [%%versioned
   module Stable = struct
@@ -222,7 +268,7 @@ module Stable = struct
       , F.Stable.V1.t
       , Mina_numbers.Global_slot.Stable.V1.t
       , bool
-      , string )
+      , Zkapp_uri.Stable.V1.t )
       Poly.Stable.V2.t
     [@@deriving sexp, equal, compare, hash, yojson]
 
@@ -237,13 +283,11 @@ type t =
   , F.t
   , Mina_numbers.Global_slot.t
   , bool
-  , string )
+  , Zkapp_uri.t )
   Poly.t
 [@@deriving sexp, equal, compare, hash, yojson]
 
-let () =
-  let _f : unit -> (t, Stable.Latest.t) Type_equal.t = fun () -> Type_equal.T in
-  ()
+let (_ : (t, Stable.Latest.t) Type_equal.t) = Type_equal.T
 
 [%%ifdef consensus_mechanism]