Avoid undefined behavior with unaligned accesses

[openssl.git] / crypto / modes / xts128.c

diff --git a/crypto/modes/xts128.c b/crypto/modes/xts128.c
index 9d9b65caa544b2b539afa5fba9da8ff373423aeb..9dbcb5bc9a41a3133fb151149a8a43ef813e4ac3 100644 (file)
--- a/crypto/modes/xts128.c
+++ b/crypto/modes/xts128.c
@@ -11,6 +11,14 @@
 #include <openssl/crypto.h>
 #include "crypto/modes.h"
 
+#ifndef STRICT_ALIGNMENT
+# ifdef __GNUC__
+typedef u64 u64_a1 __attribute((__aligned__(1)));
+# else
+typedef u64 u64_a1;
+# endif
+#endif
+
 int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
                           const unsigned char iv[16],
                           const unsigned char *inp, unsigned char *out,
@@ -45,8 +53,8 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
         scratch.u[0] ^= tweak.u[0];
         scratch.u[1] ^= tweak.u[1];
 #else
-        scratch.u[0] = ((u64 *)inp)[0] ^ tweak.u[0];
-        scratch.u[1] = ((u64 *)inp)[1] ^ tweak.u[1];
+        scratch.u[0] = ((u64_a1 *)inp)[0] ^ tweak.u[0];
+        scratch.u[1] = ((u64_a1 *)inp)[1] ^ tweak.u[1];
 #endif
         (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
 #if defined(STRICT_ALIGNMENT)
@@ -54,8 +62,8 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
         scratch.u[1] ^= tweak.u[1];
         memcpy(out, scratch.c, 16);
 #else
-        ((u64 *)out)[0] = scratch.u[0] ^= tweak.u[0];
-        ((u64 *)out)[1] = scratch.u[1] ^= tweak.u[1];
+        ((u64_a1 *)out)[0] = scratch.u[0] ^= tweak.u[0];
+        ((u64_a1 *)out)[1] = scratch.u[1] ^= tweak.u[1];
 #endif
         inp += 16;
         out += 16;
@@ -128,8 +136,8 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
         scratch.u[0] ^= tweak1.u[0];
         scratch.u[1] ^= tweak1.u[1];
 #else
-        scratch.u[0] = ((u64 *)inp)[0] ^ tweak1.u[0];
-        scratch.u[1] = ((u64 *)inp)[1] ^ tweak1.u[1];
+        scratch.u[0] = ((u64_a1 *)inp)[0] ^ tweak1.u[0];
+        scratch.u[1] = ((u64_a1 *)inp)[1] ^ tweak1.u[1];
 #endif
         (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
         scratch.u[0] ^= tweak1.u[0];
@@ -148,8 +156,8 @@ int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
         scratch.u[1] ^= tweak.u[1];
         memcpy(out, scratch.c, 16);
 #else
-        ((u64 *)out)[0] = scratch.u[0] ^ tweak.u[0];
-        ((u64 *)out)[1] = scratch.u[1] ^ tweak.u[1];
+        ((u64_a1 *)out)[0] = scratch.u[0] ^ tweak.u[0];
+        ((u64_a1 *)out)[1] = scratch.u[1] ^ tweak.u[1];
 #endif
     }