diff --git a/CMakeLists.txt b/CMakeLists.txt
index 717cae73..104aab6b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,8 +4,6 @@ project(GmSSL)
 set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
 set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
 
-option(BUILD_SHARED_LIBS "Build using shared libraries" OFF)
-
 include_directories(include)
 
 set(src
@@ -109,7 +107,6 @@ endif()
 
 
 if (WIN32)
-#	list(APPEND src src/u_time.c)
 	list(APPEND src src/rand_win.c)
 elseif (APPLE)
 	list(APPEND src src/rand_apple.c)
@@ -119,10 +116,18 @@ else()
 	list(APPEND src src/rand_unix.c)
 endif()
 
+
+
+option(BUILD_SHARED_LIBS "Build using shared libraries" ON)
+
+if (CMAKE_C_COMPILER_ID MATCHES "MSVC")
+	set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON) # set before add_library
+endif()
+
 add_library(gmssl ${src})
 
+
 if (WIN32)
-	set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
 elseif (APPLE)
 	target_link_libraries(gmssl dl)
 	target_link_libraries(gmssl "-framework Security")
diff --git a/include/gmssl/sm9.h b/include/gmssl/sm9.h
index 14d875bd..428b4c72 100644
--- a/include/gmssl/sm9.h
+++ b/include/gmssl/sm9.h
@@ -81,18 +81,14 @@ SM9 Public API
 #define SM9_HEX_SEP '\n'
 
 typedef uint64_t sm9_bn_t[8];
-extern const sm9_bn_t SM9_ZERO;
-extern const sm9_bn_t SM9_ONE;
-extern const sm9_bn_t SM9_P;
-extern const sm9_bn_t SM9_N;
 
 #define sm9_bn_init(r)		sm9_bn_set_zero(r)
 #define sm9_bn_clean(r)		sm9_bn_set_zero(r)
-#define sm9_bn_set_zero(r)	sm9_bn_copy((r), SM9_ZERO)
-#define sm9_bn_set_one(r)	sm9_bn_copy((r), SM9_ONE)
-#define sm9_bn_is_zero(a)	(sm9_bn_cmp((a), SM9_ZERO) == 0)
-#define sm9_bn_is_one(a)	(sm9_bn_cmp((a), SM9_ONE) == 0)
 
+void sm9_bn_set_zero(sm9_bn_t r);
+void sm9_bn_set_one(sm9_bn_t r);
+int  sm9_bn_is_zero(const sm9_bn_t a);
+int  sm9_bn_is_one(const sm9_bn_t a);
 void sm9_bn_set_word(sm9_bn_t r, uint32_t a);
 void sm9_bn_copy(sm9_bn_t r, const sm9_bn_t a);
 int  sm9_bn_rand_range(sm9_bn_t r, const sm9_bn_t range);
diff --git a/src/sm9_alg.c b/src/sm9_alg.c
index f732dfa1..d4e32d37 100644
--- a/src/sm9_alg.c
+++ b/src/sm9_alg.c
@@ -77,6 +77,26 @@ const SM9_TWIST_POINT _SM9_Ppubs = {
 const SM9_TWIST_POINT *SM9_Ppubs = &_SM9_Ppubs;
 
 
+void sm9_bn_set_zero(sm9_bn_t r)
+{
+	sm9_bn_copy(r, SM9_ZERO);
+}
+
+void sm9_bn_set_one(sm9_bn_t r)
+{
+	sm9_bn_copy(r, SM9_ONE);
+}
+
+int sm9_bn_is_zero(const sm9_bn_t a)
+{
+	return (sm9_bn_cmp(a, SM9_ZERO) == 0);
+}
+
+int sm9_bn_is_one(const sm9_bn_t a)
+{
+	return (sm9_bn_cmp(a, SM9_ONE) == 0);
+}
+
 void sm9_bn_to_bytes(const sm9_bn_t a, uint8_t out[32])
 {
 	int i;
diff --git a/src/sm9_key.c b/src/sm9_key.c
index 7ce3d3d7..931c30c9 100644
--- a/src/sm9_key.c
+++ b/src/sm9_key.c
@@ -23,6 +23,9 @@
 #include <gmssl/error.h>
 
 
+extern const sm9_bn_t SM9_ZERO;
+extern const sm9_bn_t SM9_N;
+
 // generate h1 in [1, n-1]
 int sm9_hash1(sm9_bn_t h1, const char *id, size_t idlen, uint8_t hid)
 {
diff --git a/src/sm9_lib.c b/src/sm9_lib.c
index 244c7aa2..597368a5 100644
--- a/src/sm9_lib.c
+++ b/src/sm9_lib.c
@@ -18,6 +18,9 @@
 #include <gmssl/asn1.h>
 #include <gmssl/error.h>
 
+
+extern const sm9_bn_t SM9_ZERO;
+extern const sm9_bn_t SM9_N;
 extern const SM9_POINT *SM9_P1;
 extern const SM9_TWIST_POINT *SM9_P2;