void * for sha3()

sha3.h

@@ -30,7 +30,7 @@ int sha3_update(sha3_ctx_t *c, const void *data, size_t len);
 int sha3_final(void *md, sha3_ctx_t *c);    // digest goes to md
 
 // compute a sha3 hash (md) of given byte length from "in"
-unsigned char *sha3(const uint8_t *in, size_t inlen, uint8_t *md, int mdlen);
+void *sha3(const uint8_t *in, size_t inlen, void *md, int mdlen);
 
 #endif