feat(crypto): Sanitize undefined behavior.

crypto/Makefile

@@ -3,7 +3,7 @@ CC       ?= clang
 LD       ?= $(CC)
 SANFLAGS += -fsanitize=fuzzer
 else ifeq ($(ADDRESS_SANITIZER),1)
-SANFLAGS += -fsanitize=address
+SANFLAGS += -fsanitize=address,undefined
 endif
 
 CC       ?= gcc

crypto/groestl.c

@@ -688,6 +688,10 @@ groestl_big_init(sph_groestl_big_context *sc, unsigned out_size)
 static void
 groestl_big_core(sph_groestl_big_context *sc, const void *data, size_t len)
 {
+  if (len == 0) {
+    return;
+  }
+
 	unsigned char *buf = NULL;
 	size_t ptr = 0;
 	DECL_STATE_BIG

crypto/sha3.c

@@ -283,6 +283,8 @@ static void sha3_process_block(uint64_t hash[25], const uint64_t *block, size_t
  */
 void sha3_Update(SHA3_CTX *ctx, const unsigned char *msg, size_t size)
 {
+  if (size == 0) return;
+
 	size_t idx = (size_t)ctx->rest;
 	size_t block_size = (size_t)ctx->block_size;
 

storage/tests/c/Makefile

@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS = -Wall -Wshadow -Wextra -Wpedantic -Werror -Wno-missing-braces -fPIC -fsanitize=address
+CFLAGS = -Wall -Wshadow -Wextra -Wpedantic -Werror -Wno-missing-braces -fPIC -fsanitize=address,undefined
 LIBS =
 INC = -I ../../../crypto -I ../.. -I .
 BASE = ../../../