From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 1 Aug 2021 00:12:35 +0000 (+0100)
Subject: own hmac, tests, pass
X-Git-Tag: hippotat/1.0.0~406
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?a=commitdiff_plain;h=4c9be85e2dc8338d6cb046c0e0b2fbc00f4ccb5d;p=hippotat.git

own hmac, tests, pass

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/src/utils.rs b/src/utils.rs
index a47b848..868dd11 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -19,13 +19,15 @@ impl<T,E> Result<T,E> where AE: From<E> {
 use sha2::Digest as _;
 
 type HmacH = sha2::Sha256;
+const HMAC_B: usize = 64;
 const HMAC_L: usize = 32;
 
-fn token_hmac(key: &[u8], message: &[u8]) -> [u8; HMAC_L] {
+pub fn token_hmac(key: &[u8], message: &[u8]) -> [u8; HMAC_L] {
   let key = {
-    let mut padded = [0; HMAC_L];
-    if key.len() > HMAC_L {
-      padded = HmacH::digest(key).into();
+    let mut padded = [0; HMAC_B];
+    if key.len() > padded.len() {
+      let digest: [u8; HMAC_L] = HmacH::digest(key).into();
+      padded[0..HMAC_L].copy_from_slice(&digest);
     } else {
       padded[0.. key.len()].copy_from_slice(key);
     }
@@ -34,6 +36,8 @@ fn token_hmac(key: &[u8], message: &[u8]) -> [u8; HMAC_L] {
   let mut ikey = key;  for k in &mut ikey { *k ^= 0x36; }
   let mut okey = key;  for k in &mut okey { *k ^= 0x5C; }
 
+//dbg!(&key, &ikey, &okey);
+
   let h1 = HmacH::new()
     .chain(&ikey)
     .chain(message)
@@ -129,7 +133,7 @@ fn hmac_test_vectors(){
 "#;
   let vectors = regex_replace_all!{
     r#"\(.*\)"#,
-    vectors,
+    vectors.trim_end(),
     |_| "",
   };
   let vectors = regex_replace_all!{