ligo/vendors/ocplib-resto/lib_resto-cohttp/cors.ml

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2017-12-07 20:43:21 +04:00
(**************************************************************************)
(* *)
(* Copyright (c) 2014 - 2017. *)
(* Dynamic Ledger Solutions, Inc. <contact@tezos.com> *)
(* *)
(* All rights reserved. No warranty, explicit or implicit, provided. *)
(* *)
(**************************************************************************)
type t = {
allowed_headers : string list ;
allowed_origins : string list ;
}
let default = { allowed_headers = [] ; allowed_origins = [] }
let check_origin_matches origin allowed_origin =
String.equal "*" allowed_origin ||
String.equal allowed_origin origin ||
begin
let allowed_w_slash = allowed_origin ^ "/" in
let len_a_w_s = String.length allowed_w_slash in
let len_o = String.length origin in
(len_o >= len_a_w_s) &&
String.equal allowed_w_slash @@ String.sub origin 0 len_a_w_s
end
let find_matching_origin allowed_origins origin =
let matching_origins =
List.filter (check_origin_matches origin) allowed_origins in
let compare_by_length_neg a b =
~- (compare (String.length a) (String.length b)) in
let matching_origins_sorted =
List.sort compare_by_length_neg matching_origins in
match matching_origins_sorted with
| [] -> None
| x :: _ -> Some x
let add_headers headers cors origin_header =
let cors_headers =
Cohttp.Header.add_multi headers
"Access-Control-Allow-Headers" cors.allowed_headers in
match origin_header with
| None -> cors_headers
| Some origin ->
match find_matching_origin cors.allowed_origins origin with
| None -> cors_headers
| Some allowed_origin ->
Cohttp.Header.add_multi cors_headers
"Access-Control-Allow-Origin" [allowed_origin]