[PATCH] sha1dc: fix issues with a big endian platform

[Junio C Hamano <gitster@pobox.com>]

From: Marc Stevens <marc@marc-stevens.nl>

Some big-endian platforms define _BIG_ENDIAN, which the test at the
beginning of file has missed.  Also, when the input is not aligned,
some platforms trigger SIGBUS.

This change corresponds to 33a694a9 ("Fix issues with a big endian
platform", 2017-05-15) in the history of the upstream repository
https://github.com/cr-marcstevens/sha1collisiondetection

---

 * So here is my attempt to clarify the log message (I left the
   title as-is, but this change deals both with endianness and
   alignment requirement).

   Please look it over, and then sign-off your patch ;-)

   Thanks.

   P.S. I wonder how often "buf" is not aligned---could we somehow
   optimize out memcpy when it is not necessary, or is it not worth
   it?

 sha1dc/sha1.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sha1dc/sha1.c b/sha1dc/sha1.c
index 35e9dd5bf4..ae25318c47 100644
--- a/sha1dc/sha1.c
+++ b/sha1dc/sha1.c
@@ -20,7 +20,7 @@
  */
 #if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || \
     (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __BIG_ENDIAN__)) || \
-    defined(__BIG_ENDIAN__) || defined(__ARMEB__) || defined(__THUMBEB__) ||  defined(__AARCH64EB__) || \
+    defined(_BIG_ENDIAN) || defined(__BIG_ENDIAN__) || defined(__ARMEB__) || defined(__THUMBEB__) ||  defined(__AARCH64EB__) || \
     defined(_MIPSEB) || defined(__MIPSEB) || defined(__MIPSEB__)
 
 #define SHA1DC_BIGENDIAN	1
@@ -1728,7 +1728,8 @@ void SHA1DCUpdate(SHA1_CTX* ctx, const char* buf, size_t len)
 	while (len >= 64)
 	{
 		ctx->total += 64;
-		sha1_process(ctx, (uint32_t*)(buf));
+		memcpy(ctx->buffer, buf, 64);
+		sha1_process(ctx, (uint32_t*)(ctx->buffer));
 		buf += 64;
 		len -= 64;
 	}
-- 
2.13.0-416-g4c6b804423