From d1e3a6e91694659be34f4ffb82e5978893aa668c Mon Sep 17 00:00:00 2001
From: Gabriel Moise <gabriel.moise@trili.tech>
Date: Tue, 29 Oct 2024 14:13:11 +0000
Subject: [PATCH] Chore: fix CI for v5-backports

---
 cohttp-async.opam       |  2 +-
 examples/async/dune     |  2 +-
 examples/async/s3_cp.ml | 29 +++++------------------------
 3 files changed, 7 insertions(+), 26 deletions(-)

diff --git a/cohttp-async.opam b/cohttp-async.opam
index 99e950b4e..1f0d88e1a 100644
--- a/cohttp-async.opam
+++ b/cohttp-async.opam
@@ -34,7 +34,7 @@ depends: [
   "cohttp" {= version}
   "conduit-async" {>= "1.2.0"}
   "magic-mime"
-  "mirage-crypto" {with-test}
+  "digestif" {with-test}
   "logs"
   "fmt" {>= "0.8.2"}
   "sexplib0"
diff --git a/examples/async/dune b/examples/async/dune
index 8d875ddcb..9bda6f013 100644
--- a/examples/async/dune
+++ b/examples/async/dune
@@ -1,6 +1,6 @@
 (executables
  (names hello_world receive_post s3_cp)
- (libraries mirage-crypto cohttp-async base async_kernel core_unix.command_unix))
+ (libraries digestif.c cohttp-async base async_kernel core_unix.command_unix))
 
 (alias
  (name runtest)
diff --git a/examples/async/s3_cp.ml b/examples/async/s3_cp.ml
index 48a6f6482..74a1ae13e 100644
--- a/examples/async/s3_cp.ml
+++ b/examples/async/s3_cp.ml
@@ -83,18 +83,6 @@ module Compat = struct
     let x = Char.to_int c in
     (hexa.[x lsr 4], hexa.[x land 0xf])
 
-  let cstruct_to_hex_string cs =
-    let open Cstruct in
-    let n = cs.len in
-    let buf = Buffer.create (n * 2) in
-    for i = 0 to n - 1 do
-      let c = cs.buffer.{cs.off + i} in
-      let x, y = of_char c in
-      Buffer.add_char buf x;
-      Buffer.add_char buf y
-    done;
-    Buffer.contents buf
-
   let encode_query_string uri =
     (* Sort and encode query string.
        Note that AWS wants null keys to have '=' for all keys.
@@ -170,8 +158,7 @@ module Auth = struct
 
   let digest s =
     (* string -> sha256 as a hex string *)
-    Mirage_crypto.Hash.(digest `SHA256 (Cstruct.of_string s))
-    |> Compat.cstruct_to_hex_string
+    Digestif.SHA256.(digest_string s |> to_hex)
 
   let make_amz_headers ?body time =
     (* Return x-amz-date and x-amz-sha256 headers *)
@@ -239,16 +226,12 @@ module Auth = struct
     Printf.sprintf "AWS4-HMAC-SHA256\n%s\n%s\n%s" time_str scope_str hashed_req
 
   let make_signing_key ?date ~region ~service ~secret_access_key () =
-    let mac k v =
-      Mirage_crypto.Hash.(mac `SHA256 ~key:k (Cstruct.of_string v))
-    in
+    let mac k v = Digestif.SHA256.(hmac_string ~key:k v |> to_raw_string) in
     let date' =
       match date with None -> Date.today ~zone:Time.Zone.utc | Some d -> d
     in
     let date_str = Date.to_string_iso8601_basic date' in
-    let date_key =
-      mac (Cstruct.of_string ("AWS4" ^ secret_access_key)) date_str
-    in
+    let date_key = mac ("AWS4" ^ secret_access_key) date_str in
     let date_region_key = mac date_key (string_of_region region) in
     let date_region_service_key =
       mac date_region_key (string_of_service service)
@@ -278,14 +261,12 @@ module Auth = struct
         (string_of_service service)
     in
     let signature =
-      Mirage_crypto.Hash.(
-        mac `SHA256 ~key:signing_key (Cstruct.of_string string_to_sign))
+      Digestif.SHA256.(hmac_string ~key:signing_key string_to_sign |> to_hex)
     in
     let auth_header =
       Printf.sprintf
         "AWS4-HMAC-SHA256 Credential=%s,SignedHeaders=%s,Signature=%s" creds
-        signed_headers
-        (Compat.cstruct_to_hex_string signature)
+        signed_headers signature
     in
     [ ("Authorization", auth_header) ]
 end