Fixed static buffer allocation for ECC signature verification

Author: danielinux

Makefile

@@ -54,7 +54,8 @@ ifeq ($(CORTEX_M0),1)
   MATH_OBJS += ./lib/wolfssl/wolfcrypt/src/sp_c32.o
 else
   CFLAGS:=-mcpu=cortex-m3
-  MATH_OBJS += ./lib/wolfssl/wolfcrypt/src/sp_cortexm.o
+  #MATH_OBJS += ./lib/wolfssl/wolfcrypt/src/sp_cortexm.o
+  MATH_OBJS += ./lib/wolfssl/wolfcrypt/src/sp_c32.o
 endif
 
 ifeq ($(FASTMATH),1)

src/xmalloc.c

@@ -5,16 +5,27 @@
 
 #define SP_POINT_SIZE (244)
 #define MAX_POINTS 2
-
 #define SCRATCHBOARD_SIZE (640)
+#define TMP_BUFFER_SIZE (124)
+#define SP_DIGITS_SIZE (400)
+#define SP_NORMALIZER_SIZE (128)
+
 static uint8_t sp_scratchboard[SCRATCHBOARD_SIZE];
 static int sp_scratchboard_in_use = 0;
 
 static uint8_t sp_point_buffer0[SP_POINT_SIZE];
 static uint8_t sp_point_buffer1[SP_POINT_SIZE];
+static uint8_t tmp_buffer[TMP_BUFFER_SIZE];
+static uint8_t sp_three_points[SP_POINT_SIZE * 3];
+static uint8_t sp_digits[SP_DIGITS_SIZE];
+static uint8_t sp_normalizer[SP_NORMALIZER_SIZE];
 
 static int point_0_in_use = 0;
 static int point_1_in_use = 0;
+static int tmp_buffer_in_use = 0;
+static int sp_three_points_in_use = 0;
+static int sp_digits_in_use = 0;
+static int sp_normalizer_in_use = 0;
 
 static void* xmalloc_sp_point(void)
 {
@@ -36,12 +47,53 @@ static void* xmalloc_sp_scratchboard(void)
     return sp_scratchboard;
 }
 
+static void* xmalloc_sp_tmpbuffer(void)
+{
+    if (tmp_buffer_in_use)
+            return NULL;
+    tmp_buffer_in_use++;
+    return tmp_buffer;
+}
+
+static void* xmalloc_sp_three_points(void)
+{
+    if (sp_three_points_in_use)
+            return NULL;
+    sp_three_points_in_use++;
+    return sp_three_points;
+}
+
+static void* xmalloc_sp_digits(void)
+{
+    if (sp_digits_in_use)
+            return NULL;
+    sp_digits_in_use++;
+    return sp_digits;
+}
+
+static void* xmalloc_sp_normalizer(void)
+{
+    if (sp_normalizer_in_use)
+            return NULL;
+    sp_normalizer_in_use++;
+    return sp_normalizer;
+}
+
+
 void* XMALLOC(size_t n, void* heap, int type)
 {
     if (n == SP_POINT_SIZE)
         return xmalloc_sp_point();
     if (n == SCRATCHBOARD_SIZE)
         return xmalloc_sp_scratchboard();
+    if (n == TMP_BUFFER_SIZE)
+        return xmalloc_sp_tmpbuffer();
+    if (n == 3 * SP_POINT_SIZE)
+        return xmalloc_sp_three_points();
+    if (n == SP_DIGITS_SIZE)
+        return xmalloc_sp_digits();
+    if (n == SP_NORMALIZER_SIZE)
+        return xmalloc_sp_normalizer();
     return NULL;
 }
 
@@ -53,4 +105,12 @@ void XFREE(void *ptr)
         point_1_in_use = 0;
     if (ptr == sp_scratchboard)
         sp_scratchboard_in_use = 0;
+    if (ptr == tmp_buffer)
+        tmp_buffer_in_use = 0;
+    if (ptr == sp_three_points)
+        sp_three_points_in_use = 0;
+    if (ptr == sp_digits)
+        sp_digits_in_use = 0;
+    if (ptr == sp_normalizer)
+        sp_normalizer_in_use = 0;
 }