crypto: explicitly check for byte read/write functions

Don't depend on hard-coded platform lists

configure.ac

@@ -368,7 +368,12 @@ if test x$TARGET_OS = xdarwin; then
   AX_CHECK_LINK_FLAG([[-Wl,-dead_strip]], [LDFLAGS="$LDFLAGS -Wl,-dead_strip"])
 fi
 
-AC_CHECK_HEADERS([stdio.h stdlib.h unistd.h strings.h sys/types.h sys/stat.h sys/select.h])
+AC_CHECK_HEADERS([endian.h stdio.h stdlib.h unistd.h strings.h sys/types.h sys/stat.h sys/select.h])
+
+AC_CHECK_DECLS([le32toh, le64toh, htole32, htole64, be32toh, be64toh, htobe32, htobe64],,,
+		[#if HAVE_ENDIAN_H
+                 #include <endian.h>
+                 #endif])
 
 dnl Check for MSG_NOSIGNAL
 AC_MSG_CHECKING(for MSG_NOSIGNAL)

src/crypto/common.h

@@ -5,42 +5,89 @@
 #ifndef BITCOIN_CRYPTO_COMMON_H
 #define BITCOIN_CRYPTO_COMMON_H
 
+#if defined(HAVE_CONFIG_H)
+#include "bitcoin-config.h"
+#endif
 #include <stdint.h>
+#if defined(HAVE_ENDIAN_H)
+#include <endian.h>
+#endif
+
+uint32_t static inline ReadLE32(const unsigned char *ptr) {
+#if HAVE_DECL_LE32TOH == 1
+    return le32toh(*((uint32_t*)ptr));
+#elif !defined(WORDS_BIGENDIAN)
+    return *((uint32_t*)ptr);
+#else
+    return ((uint32_t)ptr[3] << 24 | (uint32_t)ptr[2] << 16 | (uint32_t)ptr[1] << 8 | (uint32_t)ptr[0]);
+#endif
+}
+
+uint64_t static inline ReadLE64(const unsigned char *ptr) {
 
-#ifdef WIN32
-uint32_t static inline ReadLE32(const unsigned char *ptr) { return *((uint32_t*)ptr); }
-uint64_t static inline ReadLE64(const unsigned char *ptr) { return *((uint64_t*)ptr); }
+#if HAVE_DECL_LE64TOH == 1
+    return le64toh(*((uint64_t*)ptr));
+#elif !defined(WORDS_BIGENDIAN)
+    return *((uint64_t*)ptr);
+#else
+    return ((uint64_t)ptr[7] << 56 | (uint64_t)ptr[6] << 48 | (uint64_t)ptr[5] << 40 | (uint64_t)ptr[4] << 32 |
+            (uint64_t)ptr[3] << 24 | (uint64_t)ptr[2] << 16 | (uint64_t)ptr[1] << 8 | (uint64_t)ptr[0]);
+#endif
+}
 
-void static inline WriteLE32(unsigned char *ptr, uint32_t x) { *((uint32_t*)ptr) = x; }
-void static inline WriteLE64(unsigned char *ptr, uint64_t x) { *((uint64_t*)ptr) = x; }
+void static inline WriteLE32(unsigned char *ptr, uint32_t x) {
+#if HAVE_DECL_HTOLE32 == 1
+    *((uint32_t*)ptr) = htole32(x);
+#elif !defined(WORDS_BIGENDIAN)
+    *((uint32_t*)ptr) = x;
+#else
+    ptr[3] = x >> 24; ptr[2] = x >> 16; ptr[1] = x >> 8; ptr[0] = x;
+#endif
+}
+
+void static inline WriteLE64(unsigned char *ptr, uint64_t x) {
+#if HAVE_DECL_HTOLE64 == 1
+    *((uint64_t*)ptr) = htole64(x);
+#elif !defined(WORDS_BIGENDIAN)
+    *((uint64_t*)ptr) = x;
+#else
+    ptr[7] = x >> 56; ptr[6] = x >> 48; ptr[5] = x >> 40; ptr[4] = x >> 32;
+    ptr[3] = x >> 24; ptr[2] = x >> 16; ptr[1] = x >> 8; ptr[0] = x;
+#endif
+}
 
 uint32_t static inline ReadBE32(const unsigned char *ptr) {
+#if HAVE_DECL_BE32TOH == 1
+    return be32toh(*((uint32_t*)ptr));
+#else
     return ((uint32_t)ptr[0] << 24 | (uint32_t)ptr[1] << 16 | (uint32_t)ptr[2] << 8 | (uint32_t)ptr[3]);
+#endif
 }
 
 uint64_t static inline ReadBE64(const unsigned char *ptr) {
+#if HAVE_DECL_BE64TOH == 1
+    return be64toh(*((uint64_t*)ptr));
+#else
     return ((uint64_t)ptr[0] << 56 | (uint64_t)ptr[1] << 48 | (uint64_t)ptr[2] << 40 | (uint64_t)ptr[3] << 32 |
             (uint64_t)ptr[4] << 24 | (uint64_t)ptr[5] << 16 | (uint64_t)ptr[6] << 8 | (uint64_t)ptr[7]);
+#endif
 }
 
 void static inline WriteBE32(unsigned char *ptr, uint32_t x) {
+#if HAVE_DECL_HTOBE32 == 1
+    *((uint32_t*)ptr) = htobe32(x);
+#else
     ptr[0] = x >> 24; ptr[1] = x >> 16; ptr[2] = x >> 8; ptr[3] = x;
+#endif
 }
 
 void static inline WriteBE64(unsigned char *ptr, uint64_t x) {
+#if HAVE_DECL_HTOBE64 == 1
+    *((uint64_t*)ptr) = htobe64(x);
+#else
     ptr[0] = x >> 56; ptr[1] = x >> 48; ptr[2] = x >> 40; ptr[3] = x >> 32;
     ptr[4] = x >> 24; ptr[5] = x >> 16; ptr[6] = x >> 8; ptr[7] = x;
+#endif
 }
-#else
-#  include <endian.h>
-uint32_t static inline ReadLE32(const unsigned char *ptr) { return le32toh(*((uint32_t*)ptr)); }
-uint64_t static inline ReadLE64(const unsigned char *ptr) { return le64toh(*((uint64_t*)ptr)); }
-void static inline WriteLE32(unsigned char *ptr, uint32_t x) { *((uint32_t*)ptr) = htole32(x); }
-void static inline WriteLE64(unsigned char *ptr, uint64_t x) { *((uint64_t*)ptr) = htole64(x); }
 
-uint32_t static inline ReadBE32(const unsigned char *ptr) { return be32toh(*((uint32_t*)ptr)); }
-uint64_t static inline ReadBE64(const unsigned char *ptr) { return be64toh(*((uint64_t*)ptr)); }
-void static inline WriteBE32(unsigned char *ptr, uint32_t x) { *((uint32_t*)ptr) = htobe32(x); }
-void static inline WriteBE64(unsigned char *ptr, uint64_t x) { *((uint64_t*)ptr) = htobe64(x); }
-#endif
 #endif