diff --git a/src/mask.c b/src/mask.c
index 3648e3b490..52f118c527 100644
--- a/src/mask.c
+++ b/src/mask.c
@@ -1737,6 +1737,8 @@ void mask_done()
 	MEM_FREE(template_key_offsets);
 	if (!mask_skip_ranges)
 		MEM_FREE(mask_skip_ranges);
+	if (!mask_int_cand.int_cand)
+		MEM_FREE(mask_int_cand.int_cand);
 
 	if (!(options.flags & FLG_MASK_STACKED)) {
 		if (parsed_mask.parse_ok &&
diff --git a/src/mask_ext.c b/src/mask_ext.c
index 0b59217cc3..f756806c1b 100644
--- a/src/mask_ext.c
+++ b/src/mask_ext.c
@@ -13,30 +13,8 @@
 
 int *mask_skip_ranges = NULL;
 int mask_max_skip_loc = -1;
-int mask_int_cand_target = 0;
-
-static void combination_util(int *, int, int, int, int,
-			     cpu_mask_context *, int *);
-
-void mask_calc_combination(cpu_mask_context *ptr) {
-	int *data, i, n;
-	int delta_to_target = 0x7fffffff;
-	if (!mask_int_cand_target) return;
-
-	n = ptr->count;
-	data = (int*) malloc(n * sizeof(int));
-	mask_skip_ranges = (int*) malloc (MASK_FMT_INT_PLHDR * sizeof(int));
-
-	for (i = 0; i < MASK_FMT_INT_PLHDR; i++)
-		mask_skip_ranges[i] = -1;
-
-	/* Fix the maximum number of ranges that can be calculated on GPU to 3 */
-	for (i = 1; i <= MASK_FMT_INT_PLHDR; i++)
-		combination_util(data, 0, n - 1, 0, i, ptr,
-				 &delta_to_target);
-
-	MEM_FREE(data);
-}
+int mask_int_cand_target = 100;
+mask_int_cand_ctx mask_int_cand;
 
 static void combination_util(int *data, int start, int end, int index,
                              int r, cpu_mask_context *ptr, int *delta) {
@@ -67,3 +45,83 @@ static void combination_util(int *data, int start, int end, int index,
 				 r, ptr, delta);
 	}
 }
+
+static void generate_int_keys(cpu_mask_context *ptr) {
+	int i, repeat = 1, modulo;
+
+#define fill_cand(t) \
+	for (i = 0; i < mask_int_cand.num_int_cand; i++) \
+		mask_int_cand.int_cand[i].x[t] =	 \
+			ptr->ranges[mask_skip_ranges[t]].chars \
+			[(i/repeat) % modulo];
+#define cond(t) t < MASK_FMT_INT_PLHDR && mask_skip_ranges[t] != -1
+
+	for (i = 1; i < MASK_FMT_INT_PLHDR && mask_skip_ranges[i] != -1; i++)
+		repeat *= ptr->ranges[mask_skip_ranges[i]].count;
+	modulo = ptr->ranges[mask_skip_ranges[0]].count;
+	fill_cand(0);
+
+	if (cond(1)) {
+		modulo = ptr->ranges[mask_skip_ranges[1]].count;
+		repeat /= modulo;
+		fill_cand(1);
+	}
+	if (cond(2)) {
+		modulo = ptr->ranges[mask_skip_ranges[2]].count;
+		repeat /= modulo;
+		fill_cand(2);
+	}
+	if (cond(3)) {
+		repeat = 1;
+		modulo = ptr->ranges[mask_skip_ranges[3]].count;
+		fill_cand(3);
+	}
+#undef fill_cand
+#undef cond
+}
+
+void mask_calc_combination(cpu_mask_context *ptr) {
+	int *data, i, n;
+	int delta_to_target = 0x7fffffff;
+
+	mask_int_cand.num_int_cand = 0;
+	mask_int_cand.int_cpu_mask_ctx = NULL;
+	mask_int_cand.int_cand = NULL;
+
+	if (!mask_int_cand_target) return;
+	if (MASK_FMT_INT_PLHDR > 4) {
+		fprintf(stderr, "MASK_FMT_INT_PLHDR value must not exceed 4.\n");
+		error();
+	}
+
+	n = ptr->count;
+	data = (int*) malloc(n * sizeof(int));
+	mask_skip_ranges = (int*) malloc (MASK_FMT_INT_PLHDR * sizeof(int));
+
+	for (i = 0; i < MASK_FMT_INT_PLHDR; i++)
+		mask_skip_ranges[i] = -1;
+
+	/* Fix the maximum number of ranges that can be calculated on GPU to 3 */
+	for (i = 1; i <= MASK_FMT_INT_PLHDR; i++)
+		combination_util(data, 0, n - 1, 0, i, ptr,
+				 &delta_to_target);
+
+	if (mask_skip_ranges[0] != -1) {
+		mask_int_cand.num_int_cand = 1;
+		for (i = 0; i < MASK_FMT_INT_PLHDR &&
+		     mask_skip_ranges[i] != -1; i++)
+			mask_int_cand.num_int_cand *= ptr->
+				ranges[mask_skip_ranges[i]].count;
+	}
+
+	if (mask_int_cand.num_int_cand) {
+		mask_int_cand.int_cpu_mask_ctx = ptr;
+		mask_int_cand.int_cand = (mask_char4*)
+			malloc(mask_int_cand.num_int_cand * sizeof(mask_char4));
+		generate_int_keys(ptr);
+	}
+
+	for (i = 0; i < mask_int_cand.num_int_cand; i++)
+		fprintf(stderr, "%c%c%c%c\n", mask_int_cand.int_cand[i].x[0], mask_int_cand.int_cand[i].x[1], mask_int_cand.int_cand[i].x[2], mask_int_cand.int_cand[i].x[3]);
+	MEM_FREE(data);
+}
\ No newline at end of file
diff --git a/src/mask_ext.h b/src/mask_ext.h
index 17dd8119a7..98181ce4de 100644
--- a/src/mask_ext.h
+++ b/src/mask_ext.h
@@ -13,11 +13,22 @@
 
 #include "mask.h"
 
-#define MASK_FMT_INT_PLHDR 		3
+#define MASK_FMT_INT_PLHDR 		4
+
+typedef struct {
+	char x[4];
+} mask_char4;
+
+typedef struct {
+	mask_char4 *int_cand;
+	cpu_mask_context *int_cpu_mask_ctx;
+	int num_int_cand;
+} mask_int_cand_ctx;
 
 extern void mask_calc_combination(cpu_mask_context *);
 extern int *mask_skip_ranges;
 extern int mask_max_skip_loc;
 extern int mask_int_cand_target;
+extern mask_int_cand_ctx mask_int_cand;
 
 #endif
\ No newline at end of file