Implement multipliers.

1 files changed, 37 insertions, 0 deletions

diff --git a/pyecsca/codegen/templates/mult_rtl.c b/pyecsca/codegen/templates/mult_rtl.c
new file mode 100644
index 0000000..af437e0
--- /dev/null
+++ b/pyecsca/codegen/templates/mult_rtl.c
@@ -0,0 +1,37 @@
+#include "mult.h"
+#include "point.h"
+
+void scalar_mult(bn_t *scalar, point_t *point, curve_t *curve, point_t *out) {
+	point_t *q = point_copy(point);
+	point_t *r = point_copy(curve->neutral);
+
+	{%- if scalarmult.always %}
+		point_t *dummy = point_new();
+	{%- endif %}
+	bn_t copy;
+	bn_init(&copy);
+	bn_copy(scalar, &copy);
+
+    while (!bn_is_0(&copy)) {
+        if (bn_get_bit(&copy, i) == 1) {
+            point_add(q, r, curve, r);
+        } else {
+        	{%- if scalarmult.always %}
+			point_add(q, r, curve, dummy);
+			{%- endif %}
+        }
+        point_dbl(q, curve, q);
+        bn_rsh(&copy, 1, &copy);
+    }
+    {%- if "scl" in scalarmult.formulas %}
+    	point_scl(r, curve, r);
+    {%- endif %}
+
+    point_set(r, out);
+    point_free(q);
+    point_free(r);
+    bn_clear(&copy);
+	{%- if scalarmult.always %}
+		point_free(dummy);
+	{%- endif %}
+}
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