1 files changed, 13 insertions, 0 deletions
diff --git a/ext/ed25519-amd64-asm/ge25519_pack.c b/ext/ed25519-amd64-asm/ge25519_pack.c
new file mode 100644
index 00000000..f289fe57
--- /dev/null
+++ b/ext/ed25519-amd64-asm/ge25519_pack.c
@@ -0,0 +1,13 @@
+#include "fe25519.h"
+#include "sc25519.h"
+#include "ge25519.h"
+
+void ge25519_pack(unsigned char r[32], const ge25519_p3 *p)
+{
+  fe25519 tx, ty, zi;
+  fe25519_invert(&zi, &p->z); 
+  fe25519_mul(&tx, &p->x, &zi);
+  fe25519_mul(&ty, &p->y, &zi);
+  fe25519_pack(r, &ty);
+  r[31] ^= fe25519_getparity(&tx) << 7;
+}