From 66287d37ee996d7ee8e067ff649720cbbab9bae2 Mon Sep 17 00:00:00 2001
From: Kévin Le Gouguec <kevin.legouguec@airbus.com>
Date: Fri, 22 Mar 2019 08:41:23 +0100
Subject: Simplification et documentation de pad10*

Pas besoin de la condition. Ajout d'un exemple.
---
 src/ref/lilliput-ae-utils.h | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

(limited to 'src/ref')

diff --git a/src/ref/lilliput-ae-utils.h b/src/ref/lilliput-ae-utils.h
index 41acaf6..ce3f154 100644
--- a/src/ref/lilliput-ae-utils.h
+++ b/src/ref/lilliput-ae-utils.h
@@ -70,18 +70,24 @@ static inline void pad10(size_t X_len, const uint8_t X[X_len], uint8_t padded[BL
 {
     /* pad10*(X) = X || 1 || 0^{n-|X|-1} */
 
+    /* For example, with uint8_t X[3] = { [0]=0x01, [1]=0x02, [2]=0x03 }
+     *
+     * pad10*(X) =
+     *       X[2]     X[1]     X[0]   1 0*
+     *     00000011 00000010 00000001 1 0000000 00000000...
+     *
+     * - padded[0, 11]:  zeroes
+     * - padded[12]:     10000000
+     * - padded[13, 15]: X[0, 2]
+     */
+
     /* Assume that X_len<BLOCK_BYTES. */
 
     size_t pad_len = BLOCK_BYTES-X_len;
 
-    memcpy(padded+pad_len, X, X_len);
-
+    memset(padded, 0, pad_len-1);
     padded[pad_len-1] = 0x80;
-
-    if (pad_len > 1)
-    {
-        memset(padded, 0, pad_len-1);
-    }
+    memcpy(padded+pad_len, X, X_len);
 }
 
 static inline void fill_index_tweak(
-- 
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