1 files changed, 68 insertions, 0 deletions
diff --git a/ext/ed25519-amd64-asm/ge25519_scalarmult_base.c b/ext/ed25519-amd64-asm/ge25519_scalarmult_base.c
new file mode 100644
index 00000000..986abaf6
--- /dev/null
+++ b/ext/ed25519-amd64-asm/ge25519_scalarmult_base.c
@@ -0,0 +1,68 @@
+#include "fe25519.h"
+#include "sc25519.h"
+#include "ge25519.h"
+
+/* Multiples of the base point in Niels' representation */
+static const ge25519_niels ge25519_base_multiples_niels[] = {
+#ifdef SMALLTABLES
+#include "ge25519_base_niels_smalltables.data"
+#else
+#include "ge25519_base_niels.data"
+#endif
+};
+
+/* d */
+static const fe25519 ecd = {{0x75EB4DCA135978A3, 0x00700A4D4141D8AB, 0x8CC740797779E898, 0x52036CEE2B6FFE73}};
+
+void ge25519_scalarmult_base(ge25519_p3 *r, const sc25519 *s)
+{
+  signed char b[64];
+  int i;
+  ge25519_niels t;
+  fe25519 d;
+
+  sc25519_window4(b,s);
+
+#ifdef SMALLTABLES
+  ge25519_p1p1 tp1p1;
+  choose_t((ge25519_niels *)r, 0, (signed long long) b[1], ge25519_base_multiples_niels);
+  fe25519_sub(&d, &r->y, &r->x);
+  fe25519_add(&r->y, &r->y, &r->x);
+  r->x = d;
+  r->t = r->z;
+  fe25519_setint(&r->z,2);
+  for(i=3;i<64;i+=2)
+  {
+    choose_t(&t, (unsigned long long) i/2, (signed long long) b[i], ge25519_base_multiples_niels);
+    ge25519_nielsadd2(r, &t);
+  }
+  ge25519_dbl_p1p1(&tp1p1,(ge25519_p2 *)r);
+  ge25519_p1p1_to_p2((ge25519_p2 *)r, &tp1p1);
+  ge25519_dbl_p1p1(&tp1p1,(ge25519_p2 *)r);
+  ge25519_p1p1_to_p2((ge25519_p2 *)r, &tp1p1);
+  ge25519_dbl_p1p1(&tp1p1,(ge25519_p2 *)r);
+  ge25519_p1p1_to_p2((ge25519_p2 *)r, &tp1p1);
+  ge25519_dbl_p1p1(&tp1p1,(ge25519_p2 *)r);
+  ge25519_p1p1_to_p3(r, &tp1p1);
+  choose_t(&t, (unsigned long long) 0, (signed long long) b[0], ge25519_base_multiples_niels);
+  fe25519_mul(&t.t2d, &t.t2d, &ecd);
+  ge25519_nielsadd2(r, &t);
+  for(i=2;i<64;i+=2)
+  {
+    choose_t(&t, (unsigned long long) i/2, (signed long long) b[i], ge25519_base_multiples_niels);
+    ge25519_nielsadd2(r, &t);
+  }
+#else 
+  choose_t((ge25519_niels *)r, 0, (signed long long) b[0], ge25519_base_multiples_niels);
+  fe25519_sub(&d, &r->y, &r->x);
+  fe25519_add(&r->y, &r->y, &r->x);
+  r->x = d;
+  r->t = r->z;
+  fe25519_setint(&r->z,2);
+  for(i=1;i<64;i++)
+  {
+    choose_t(&t, (unsigned long long) i, (signed long long) b[i], ge25519_base_multiples_niels);
+    ge25519_nielsadd2(r, &t);
+  }
+#endif 
+}