From 7d7dd2400c2a7c83273e14efe3c8d3bb61ac4d91 Mon Sep 17 00:00:00 2001
From: swrup <swrup@protonmail.com>
Date: Tue, 10 Feb 2026 16:47:08 +0100
Subject: [PATCH] hash: use of_raw_string_opt

---
 src/b32.ml     |  4 ++++
 src/hash.ml    | 20 ++++++++------------
 test/b32.ml    | 15 ---------------
 test/crypto.ml | 28 ++++++++++++++++++++++++++++
 test/dune      |  6 +++---
 5 files changed, 43 insertions(+), 30 deletions(-)
 delete mode 100644 test/b32.ml
 create mode 100644 test/crypto.ml

diff --git a/src/b32.ml b/src/b32.ml
index 12ef4294..6bd06400 100644
--- a/src/b32.ml
+++ b/src/b32.ml
@@ -29,6 +29,10 @@ let decode s =
         | c -> c)
       s
   in
+  (* restore padding for base32 lib *)
+  let n = 8 - (String.length s mod 8) in
+  let pad = String.make n '=' in
+  let s = s ^ pad in
   match Base32.decode ~alphabet ~off:0 ~len:(String.length s) s with
   | Error (`Msg e) -> Error e
   | Ok v -> Ok v
diff --git a/src/hash.ml b/src/hash.ml
index ca32519f..0da809df 100644
--- a/src/hash.ml
+++ b/src/hash.ml
@@ -1,3 +1,4 @@
+(* TODO use SHA512.of_raw_string_opt *)
 open Digestif
 
 module type S = sig
@@ -18,9 +19,9 @@ module H32 = struct
   let hash s = SHA256.(digest_string s)
 
   let of_octets s =
-    match String.length s = 32 with
-    | false -> Fmt.failwith "Hash.of_octets failure: data is not 32 bytes"
-    | true -> SHA256.of_raw_string s
+    match SHA256.of_raw_string_opt s with
+    | None -> Fmt.failwith "H32.of_octets failure: data is not 32 bytes"
+    | Some t -> t
 
   let to_octets = SHA256.to_raw_string
   let of_b32 s = Result.map of_octets (B32.decode s)
@@ -48,16 +49,11 @@ module H64 = struct
   let hash s = SHA512.(digest_string s)
 
   let of_octets s =
-    match String.length s = 64 with
-    | false -> Fmt.failwith "Hash.of_octets failure: data is not 64 bytes"
-    | true -> SHA512.of_raw_string s
-
-  let to_octets v =
-    let s = SHA512.to_raw_string v in
-    match String.length s = 64 with
-    | false -> Fmt.failwith "Hash.to_octets failure: data is not 64 bytes"
-    | true -> s
+    match SHA512.of_raw_string_opt s with
+    | None -> Fmt.failwith "H64.of_octets failure: data is not 64 bytes"
+    | Some t -> t
 
+  let to_octets = SHA512.to_raw_string
   let of_b32 s = Result.map of_octets (B32.decode s)
 
   let bin =
diff --git a/test/b32.ml b/test/b32.ml
deleted file mode 100644
index c6986084..00000000
--- a/test/b32.ml
+++ /dev/null
@@ -1,15 +0,0 @@
-let () =
-  let id s = s |> B32.encode |> B32.decode |> Result.get_ok in
-  let f s =
-    let s' = id s in
-    match s' = s with
-    | false ->
-        Fmt.failwith "b32 round trip failure: @\nin :`%S`@\nout:`%S`" s' s
-    | true -> ()
-  in
-  let s = String.init 0xff Char.chr in
-  let s_l = List.init 0x0f (fun i -> String.init i Char.chr) in
-  f s;
-  List.iter f s_l;
-
-  ()
diff --git a/test/crypto.ml b/test/crypto.ml
new file mode 100644
index 00000000..e2d007c9
--- /dev/null
+++ b/test/crypto.ml
@@ -0,0 +1,28 @@
+let round_trip s =
+  let s' = s |> B32.encode |> B32.decode |> Result.get_ok in
+  match s' = s with
+  | false -> Fmt.failwith "b32 round trip failure: @\nin :`%S`@\nout:`%S`" s' s
+  | true -> ()
+
+let () =
+  let s = String.init 0xff Char.chr in
+  round_trip s;
+  let s_l = List.init 0x0f (fun i -> String.init i Char.chr) in
+  List.iter round_trip s_l; ()
+
+let () =
+  let input = "91JPRV3F5GG4EKJNDSJQ8" in
+  let expected =
+    "D0R24RZ1TPASVQ2NY56CT8AJDYZE9ZGDB0GVZ05E9D4YGZQW2RC5YFPQ0Q86EPW836DY7VYQTNFFJT3ZR2K508F4JVS5JNJKYN2MMFR"
+  in
+  let output =
+    input
+    |> B32.decode
+    |> Result.get_ok
+    |> Hash.H64.hash
+    |> Hash.H64.to_octets
+    |> B32.encode
+  in
+  assert (output = expected);
+
+  ()
diff --git a/test/dune b/test/dune
index bec41ef4..1aa7506a 100644
--- a/test/dune
+++ b/test/dune
@@ -4,9 +4,9 @@
  (libraries mte fmt))
 
 (test
- (name b32)
- (modules b32)
- (libraries b32 fmt))
+ (name crypto)
+ (modules crypto)
+ (libraries mte fmt))
 
 ; TODO
 ; cram test?