Fallback on 32bit implementation when on BigEndian hardware.

keccak-64-be.diff

diff --git a/ext/hash/config.m4 b/ext/hash/config.m4
index 66cc7ca810..1f3fd576ab 100644
--- a/ext/hash/config.m4
+++ b/ext/hash/config.m4
@@ -29,8 +29,15 @@ if test "$PHP_HASH" != "no"; then
     SHA3_DIR="sha3/generic32lc"
     SHA3_OPT_SRC="$SHA3_DIR/KeccakP-1600-inplace32BI.c"
   ],[
-    SHA3_DIR="sha3/generic64lc"
-    SHA3_OPT_SRC="$SHA3_DIR/KeccakP-1600-opt64.c"
+    if test $ac_cv_c_bigendian_php = yes; then
+      dnl Keccak library does not yet support BE-64
+      SHA3_DIR="sha3/generic32lc"
+      SHA3_OPT_SRC="$SHA3_DIR/KeccakP-1600-inplace32BI.c"
+      AC_MSG_NOTICE([Falling back on 32bit SHA3 for BigEndian platform])
+    else
+      SHA3_DIR="sha3/generic64lc"
+      SHA3_OPT_SRC="$SHA3_DIR/KeccakP-1600-opt64.c"
+    fi
   ])
   EXT_HASH_SHA3_SOURCES="$SHA3_OPT_SRC $SHA3_DIR/KeccakHash.c $SHA3_DIR/KeccakSponge.c"
   PHP_HASH_CFLAGS="-I@ext_srcdir@/$SHA3_DIR -DKeccakP200_excluded -DKeccakP400_excluded -DKeccakP800_excluded"