From ab197b6b34bdb15d809945277e0e4b700db72a68 Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Tue, 30 Oct 2018 10:26:05 +0000
Subject: [PATCH] symm/ecb-def.h: Simplify the discarding-output path.

Because ECB is stateless, there is nothing to do if we discard the
output.
---
 symm/ecb-def.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/symm/ecb-def.h b/symm/ecb-def.h
index 957a16e3..c69790de 100644
--- a/symm/ecb-def.h
+++ b/symm/ecb-def.h
@@ -126,9 +126,9 @@ void pre##_ecbencrypt(pre##_ecbctx *ctx,				\
   octet y;								\
   unsigned i;								\
 									\
-  /* --- Empty blocks are trivial --- */				\
+  /* --- Empty blocks are trivial, and ECB is stateless --- */		\
 									\
-  if (!sz) return;							\
+  if (!sz || !d) return;						\
 									\
   /* --- Short blocks aren't allowed in ECB --- *			\
    *									\
@@ -149,7 +149,7 @@ void pre##_ecbencrypt(pre##_ecbctx *ctx,				\
     if (!s) BLKC_ZERO(PRE, t);						\
     else { BLKC_LOAD(PRE, t, s); s += PRE##_BLKSZ; }			\
     pre##_eblk(&ctx->ctx, t, t);					\
-    if (d) { BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ; }			\
+    BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ;				\
     sz -= PRE##_BLKSZ;							\
   }									\
 									\
@@ -183,11 +183,11 @@ void pre##_ecbencrypt(pre##_ecbctx *ctx,				\
      * ciphertext block.						\
      */									\
 									\
-    if (d) d += PRE##_BLKSZ;						\
-    for (i = 0; i < sz; i++) { y = b[i]; b[i] = s[i]; if (d) d[i] = y; } \
+    d += PRE##_BLKSZ;							\
+    for (i = 0; i < sz; i++) { y = b[i]; b[i] = s[i]; d[i] = y; }	\
     BLKC_LOAD(PRE, t, b);						\
     pre##_eblk(&ctx->ctx, t, t);					\
-    if (d) BLKC_STORE(PRE, d - PRE##_BLKSZ, t);				\
+    BLKC_STORE(PRE, d - PRE##_BLKSZ, t);				\
   }									\
 									\
   /* --- Done --- */							\
-- 
2.11.0