sid: sid_test: validate identifier authority on create()

Reject ia’s greater than six bytes can encompass.

3 files changed, 22 insertions, 4 deletions

diff --git a/sid.ml b/sid.ml
index 0d5c89b..2cced76 100644
--- a/sid.ml
+++ b/sid.ml
@@ -22,6 +22,7 @@ let create_unsafe sa ia =
    the number of subauths. *)
 let create ?(sa=[||]) ia =
   if Array.length sa > max_subauth_count then None else
+  if U64.compare ia max_ident_auth > 0 then None else
   Some (create_unsafe sa ia)
 
 let get_ident_auth s = s.sid_ident_auth
diff --git a/sid.mli b/sid.mli
index 0a9fbd8..8c3a5fa 100644
--- a/sid.mli
+++ b/sid.mli
@@ -6,7 +6,8 @@ type sub_auths = Stdint.Uint32.t array
 val create : ?sa:Stdint.Uint32.t array -> Stdint.Uint64.t -> t option
 (** [create sas ia] constructs a SID with the identifier authority [ia]
     and, optionally, the subauthorities [sas]. The operation will return
-    [None] if [sa] contains more than fifteen subauthorities. *)
+    [None] if [sa] contains more than fifteen subauthorities, or if [ia]
+    exceeds 48 bits. *)
 
 val create_unsafe : Stdint.Uint32.t array -> Stdint.Uint64.t -> t
 (** [create_unsafe sas ia] constructs a SID with the identifier authority [ia]
@@ -60,7 +61,7 @@ module PacketRep :
         to channel [oc] with endianness [endian]. *)
   end
 
-(** Pre-defined SID constansts and constructors with fixed identifier
+(** Pre-defined SID constants and constructors with fixed identifier
     authority (MS-DTYP 2.4.2.4). *)
 module WellKnown :
   sig
diff --git a/sid_test.ml b/sid_test.ml
index 97af2a3..9b61b40 100644
--- a/sid_test.ml
+++ b/sid_test.ml
@@ -31,12 +31,21 @@ let create_ok () =
     (Printf.sprintf "[%s] ≠ [%s]" (Sid.to_string s) (Sid.to_string w))
     (Sid.equal s w)
 
-let create_fail () =
+let create_etoomany_fail () =
   let sas = Array.make 16 U32.one in
   match Sid.create ~sa:sas U64.zero with
     | None -> ()
     | Some s -> assert_failure ("Sid.create succeeded on invalid sa array")
 
+let max_ident_auth = U64.of_string "0x0000_ffff_ffff_ffff"
+
+let create_iatoobig_fail () =
+  let sas = Array.make 2 U32.one in
+  let ia = U64.add max_ident_auth U64.one in
+  match Sid.create ~sa:sas ia with
+    | None -> ()
+    | Some s -> assert_failure ("Sid.create succeeded on invalid ident auth")
+
 let unwrap_of_string s =
   match Sid.of_string s with
     | Error e ->
@@ -345,7 +354,14 @@ let packet_rep_test = "packet-rep" >:::
   ; "decode-odd-fail"       >:: pr_decode_odd_fail
   ]
 
+let toplevel_test = "toplevel" >:::
+  [ "create-ok"             >:: create_ok
+  ; "create-etoomany-fail"  >:: create_etoomany_fail
+  ; "create-iatoobig-fail"  >:: create_iatoobig_fail
+  ]
+
 let () =
   ignore (run_test_tt_main string_format_test);
-  ignore (run_test_tt_main packet_rep_test   )
+  ignore (run_test_tt_main packet_rep_test   );
+  ignore (run_test_tt_main toplevel_test   )