move endian/word size checks from runtime to compile time

ok guenther@

1 files changed, 34 insertions, 36 deletions

diff --git a/src/lib/libcrypto/modes/xts128.c b/src/lib/libcrypto/modes/xts128.c
index 3e2378379e..0be23d4ea9 100644
--- a/src/lib/libcrypto/modes/xts128.c
+++ b/src/lib/libcrypto/modes/xts128.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: xts128.c,v 1.6 2015/02/10 09:46:30 miod Exp $ */
+/* $OpenBSD: xts128.c,v 1.7 2017/08/13 17:46:24 bcook Exp $ */
 /* ====================================================================
  * Copyright (c) 2011 The OpenSSL Project.  All rights reserved.
  *
@@ -98,25 +98,24 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char iv[16],
 
                 if (len==0)     return 0;
 
-                if (BYTE_ORDER == LITTLE_ENDIAN) {
-                        unsigned int carry,res;
-                        
-                        res = 0x87&(((int)tweak.d[3])>>31);
-                        carry = (unsigned int)(tweak.u[0]>>63);
-                        tweak.u[0] = (tweak.u[0]<<1)^res;
-                        tweak.u[1] = (tweak.u[1]<<1)|carry;
-                }
-                else {
-                        size_t c;
-
-                        for (c=0,i=0;i<16;++i) {
-                                /*+ substitutes for |, because c is 1 bit */ 
-                                c += ((size_t)tweak.c[i])<<1;
-                                tweak.c[i] = (u8)c;
-                                c = c>>8;
-                        }
-                        tweak.c[0] ^= (u8)(0x87&(0-c));
+#if BYTE_ORDER == LITTLE_ENDIAN
+                unsigned int carry,res;
+
+                res = 0x87&(((int)tweak.d[3])>>31);
+                carry = (unsigned int)(tweak.u[0]>>63);
+                tweak.u[0] = (tweak.u[0]<<1)^res;
+                tweak.u[1] = (tweak.u[1]<<1)|carry;
+#else /* BIG_ENDIAN */
+                size_t c;
+
+                for (c=0,i=0;i<16;++i) {
+                        /*+ substitutes for |, because c is 1 bit */
+                        c += ((size_t)tweak.c[i])<<1;
+                        tweak.c[i] = (u8)c;
+                        c = c>>8;
                 }
+                tweak.c[0] ^= (u8)(0x87&(0-c));
+#endif
         }
         if (enc) {
                 for (i=0;i<len;++i) {
@@ -134,25 +133,24 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char iv[16],
         else {
                 union { u64 u[2]; u8 c[16]; } tweak1;
 
-                if (BYTE_ORDER == LITTLE_ENDIAN) {
-                        unsigned int carry,res;
+#if BYTE_ORDER == LITTLE_ENDIAN
+                unsigned int carry,res;
 
-                        res = 0x87&(((int)tweak.d[3])>>31);
-                        carry = (unsigned int)(tweak.u[0]>>63);
-                        tweak1.u[0] = (tweak.u[0]<<1)^res;
-                        tweak1.u[1] = (tweak.u[1]<<1)|carry;
-                }
-                else {
-                        size_t c;
-
-                        for (c=0,i=0;i<16;++i) {
-                                /*+ substitutes for |, because c is 1 bit */ 
-                                c += ((size_t)tweak.c[i])<<1;
-                                tweak1.c[i] = (u8)c;
-                                c = c>>8;
-                        }
-                        tweak1.c[0] ^= (u8)(0x87&(0-c));
+                res = 0x87&(((int)tweak.d[3])>>31);
+                carry = (unsigned int)(tweak.u[0]>>63);
+                tweak1.u[0] = (tweak.u[0]<<1)^res;
+                tweak1.u[1] = (tweak.u[1]<<1)|carry;
+#else
+                size_t c;
+
+                for (c=0,i=0;i<16;++i) {
+                        /*+ substitutes for |, because c is 1 bit */
+                        c += ((size_t)tweak.c[i])<<1;
+                        tweak1.c[i] = (u8)c;
+                        c = c>>8;
                 }
+                tweak1.c[0] ^= (u8)(0x87&(0-c));
+#endif
 #ifdef __STRICT_ALIGNMENT
                 memcpy(scratch.c,inp,16);
                 scratch.u[0] ^= tweak1.u[0];