From: Niels Möller <nisse@lysator.liu.se>
Date: Sat, 6 Sep 2014 15:20:10 +0000 (+0200)
Subject: Output points also for the Ed25519 curve.
X-Git-Tag: nettle_3.1rc1~122
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df7b4aca92b3cdbb324a833e1faaa59f532efb77;p=thirdparty%2Fnettle.git

Output points also for the Ed25519 curve.
---

diff --git a/misc/ecc-ref.gp b/misc/ecc-ref.gp
index 7ef73259..d963e990 100644
--- a/misc/ecc-ref.gp
+++ b/misc/ecc-ref.gp
@@ -118,4 +118,14 @@ if (S != ellpow(curve25519, B, a), error("curve25519 dh error"));
 print("curve25519");
 out(a, A, b, B, S);
 
+/* Convert point on curve25519 to a point on the twisted edwards curve */
+beta = -sqrt(Mod(-486664, p25519));
+ed25519(p) = [p[1] * beta / p[2], (p[1] - 1) / (p[1] + 1)];
+
+Ae = ed25519(A);
+Be = ed25519(B);
+Se = ed25519(S);
+print("ed25519");
+out(a, Ae, b, Be, Se);
+
 quit