Minor reorganization of hkdf_expand.hkdf-support

* hkdf.c (hkdf_expand): Eliminate a (signed) ssize_t variable, use
break rather than return at loop termination.

2 files changed, 16 insertions, 14 deletions

diff --git a/ChangeLog b/ChangeLog
index 776597a6..145376c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2017-09-06  Niels Möller  <nisse@lysator.liu.se>
 
+	* hkdf.c (hkdf_expand): Eliminate a (signed) ssize_t variable, use
+	break rather than return at loop termination.
+
+2017-09-06  Niels Möller  <nisse@lysator.liu.se>
+
 	HKDF implementation, contributed by Nikos Mavrogiannopoulos.
 	* hkdf.c (hkdf_extract, hkdf_expand): New file, new functions.
 	* hkdf.h: New file.
diff --git a/hkdf.c b/hkdf.c
index 73b10665..c55c42fd 100644
--- a/hkdf.c
+++ b/hkdf.c
@@ -63,23 +63,20 @@ hkdf_expand(void *mac_ctx,
 	    size_t length, uint8_t *dst)
 {
   uint8_t i = 1;
-  ssize_t left = length;
 
-  if (!left)
+  if (!length)
     return;
 
-  for (;; dst += digest_size, left -= digest_size, i++) {
-    update(mac_ctx, info_size, info);
-    update(mac_ctx, 1, &i);
-    if (left <= digest_size) {
-      if (left > 0)
-	digest(mac_ctx, left, dst);
-      return;
-    }
+  for (;; dst += digest_size, length -= digest_size, i++)
+    {
+      update(mac_ctx, info_size, info);
+      update(mac_ctx, 1, &i);
+      if (length <= digest_size)
+	break;
 
-    digest(mac_ctx, digest_size, dst);
-    update(mac_ctx, digest_size, dst);
-  }
+      digest(mac_ctx, digest_size, dst);
+      update(mac_ctx, digest_size, dst);
+    }
 
-  return;
+  digest(mac_ctx, length, dst);
 }