crypto: fixed incremental keccak API on big-endian platforms

src/crypto/keccak.c

@@ -145,7 +145,7 @@ void keccak1600(const uint8_t *in, size_t inlen, uint8_t *md)
 #define IS_ALIGNED_64(p) (0 == (7 & ((const char*)(p) - (const char*)0)))
 #define KECCAK_PROCESS_BLOCK(st, block) { \
     for (int i_ = 0; i_ < KECCAK_WORDS; i_++){ \
-        ((st))[i_] ^= ((block))[i_]; \
+        ((st))[i_] ^= swap64le(((block))[i_]); \
     }; \
     keccakf(st, KECCAK_ROUNDS); }
 
@@ -207,7 +207,8 @@ void keccak_finish(KECCAK_CTX * ctx, uint8_t *md){
     }
 
     static_assert(KECCAK_BLOCKLEN > KECCAK_DIGESTSIZE, "");
+    static_assert(KECCAK_DIGESTSIZE % sizeof(uint64_t) == 0, "");
     if (md) {
-        memcpy(md, ctx->hash, KECCAK_DIGESTSIZE);
+        memcpy_swap64le(md, ctx->hash, KECCAK_DIGESTSIZE / sizeof(uint64_t));
     }
 }