lib: fix byte order test in libsha1.c

Previously PLATFORM_BYTE_ORDER and IS_LITTLE_ENDIAN were not defined,
so the little endian code was always compiled in.

This will have the effect that the "SHA1s" on big endian architectures
will change (i.e. become actual sha1s). So someone re-indexing their
database could conceivable lose tags on messages without a message-id
header.

diff --git a/lib/libsha1.c b/lib/libsha1.c
index 5d16f6ab1a61363dbbcec827496842ba113338fd..87c7c52889d2944f50b59c8ad616b51b37cc3a83 100644 (file)
--- a/lib/libsha1.c
+++ b/lib/libsha1.c
@@ -49,11 +49,20 @@ extern "C"
 
 #define bswap_32(x) ((rotr32((x), 24) & 0x00ff00ff) | (rotr32((x), 8) & 0xff00ff00))
 
-#if (PLATFORM_BYTE_ORDER == IS_LITTLE_ENDIAN)
-#define bsw_32(p,n) \
-    { int _i = (n); while(_i--) ((uint32_t*)p)[_i] = bswap_32(((uint32_t*)p)[_i]); }
+/* The macros __BYTE_ORDER__ and __ORDER_*_ENDIAN__ are GNU C
+ * extensions. They are also supported by clang as of v3.2 */
+
+#ifdef __BYTE_ORDER__
+#  if (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+#    define bsw_32(p,n) \
+       { int _i = (n); while(_i--) ((uint32_t*)p)[_i] = bswap_32(((uint32_t*)p)[_i]); }
+#  elif (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
+#    define bsw_32(p,n)
+#  else
+#    error "unknown byte order"
+#  endif
 #else
-#define bsw_32(p,n)
+#    error "macro __BYTE_ORDER__ is not defined"
 #endif
 
 #define SHA1_MASK   (SHA1_BLOCK_SIZE - 1)