Clean up alignment handling for SHA-512.

This recommits r1.37 of sha512.c, however uses uint8_t * instead of void *
for the crypto_load_* functions and primarily uses const uint8_t * to track
input, only casting to const SHA_LONG64 * once we know that it is suitably
aligned. This prevents the compiler from implying alignment based on type.

Tested by tb@ and deraadt@ on platforms with gcc and strict alignment.

ok tb@

1 files changed, 44 insertions, 7 deletions

diff --git a/src/lib/libcrypto/crypto_internal.h b/src/lib/libcrypto/crypto_internal.h
index db3e99510b..4fe868e9a1 100644
--- a/src/lib/libcrypto/crypto_internal.h
+++ b/src/lib/libcrypto/crypto_internal.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: crypto_internal.h,v 1.5 2023/05/19 00:54:27 deraadt Exp $ */
+/*      $OpenBSD: crypto_internal.h,v 1.6 2023/05/27 09:18:17 jsing Exp $ */
 /*
  * Copyright (c) 2023 Joel Sing <jsing@openbsd.org>
  *
@@ -22,10 +22,30 @@
 #ifndef HEADER_CRYPTO_INTERNAL_H
 #define HEADER_CRYPTO_INTERNAL_H
 
+#define CTASSERT(x) \
+    extern char _ctassert[(x) ? 1 : -1] __attribute__((__unused__))
+
+/*
+ * crypto_load_be32toh() loads a 32 bit unsigned big endian value as a 32 bit
+ * unsigned host endian value, from the specified address in memory. The memory
+ * address may have any alignment.
+ */
+#ifndef HAVE_CRYPTO_LOAD_BE32TOH
+static inline uint32_t
+crypto_load_be32toh(const uint8_t *src)
+{
+        uint32_t v;
+
+        memcpy(&v, src, sizeof(v));
+
+        return be32toh(v);
+}
+#endif
+
 /*
- * crypto_store_htobe32() stores a 32 bit unsigned host endian value
- * as a 32 bit unsigned big endian value, at the specified location in
- * memory. The memory location may have any alignment.
+ * crypto_store_htobe32() stores a 32 bit unsigned host endian value as a 32 bit
+ * unsigned big endian value, at the specified address in memory. The memory
+ * address may have any alignment.
  */
 #ifndef HAVE_CRYPTO_STORE_HTOBE32
 static inline void
@@ -37,9 +57,26 @@ crypto_store_htobe32(uint8_t *dst, uint32_t v)
 #endif
 
 /*
- * crypto_store_htobe64() stores a 64 bit unsigned host endian value
- * as a 64 bit unsigned big endian value, at the specified location in
- * memory. The memory location may have any alignment.
+ * crypto_load_be64toh() loads a 64 bit unsigned big endian value as a 64 bit
+ * unsigned host endian value, from the specified address in memory. The memory
+ * address may have any alignment.
+ */
+#ifndef HAVE_CRYPTO_LOAD_BE64TOH
+static inline uint64_t
+crypto_load_be64toh(const uint8_t *src)
+{
+        uint64_t v;
+
+        memcpy(&v, src, sizeof(v));
+
+        return be64toh(v);
+}
+#endif
+
+/*
+ * crypto_store_htobe64() stores a 64 bit unsigned host endian value as a 64 bit
+ * unsigned big endian value, at the specified address in memory. The memory
+ * address may have any alignment.
  */
 #ifndef HAVE_CRYPTO_STORE_HTOBE64
 static inline void