From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sun, 7 May 2017 13:29:22 +0000 (+0200)
Subject: Remove unused add_scalar function.
X-Git-Tag: release-1.1pre15~15
X-Git-Url: https://git.tinc-vpn.org/git/browse?a=commitdiff_plain;h=3d8a8363544bfcf75a9124251eff0caae3a8f1a2;p=tinc

Remove unused add_scalar function.
---

diff --git a/src/Makefile.am b/src/Makefile.am
index 8e2aa038..a98c0337 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -24,7 +24,6 @@ EXTRA_PROGRAMS += sptps_speed
 endif
 
 ed25519_SOURCES = \
-	ed25519/add_scalar.c \
 	ed25519/ed25519.h \
 	ed25519/fe.c ed25519/fe.h \
 	ed25519/fixedint.h \
diff --git a/src/ed25519/add_scalar.c b/src/ed25519/add_scalar.c
deleted file mode 100644
index 262ec725..00000000
--- a/src/ed25519/add_scalar.c
+++ /dev/null
@@ -1,56 +0,0 @@
-#include "ed25519.h"
-#include "ge.h"
-#include "sc.h"
-
-
-/* see http://crypto.stackexchange.com/a/6215/4697 */
-void ed25519_add_scalar(unsigned char *public_key, unsigned char *private_key, const unsigned char *scalar) {
-    const unsigned char SC_1[32] = {1}; /* scalar with value 1 */
-    
-    unsigned char n[32]; 
-    ge_p3 nB;
-    ge_p1p1 A_p1p1;
-    ge_p3 A;
-    ge_p3 public_key_unpacked;
-    ge_cached T;
-
-    int i;
-
-    /* copy the scalar and clear highest bit */
-    for (i = 0; i < 31; ++i) {
-        n[i] = scalar[i];
-    }
-    n[31] = scalar[31] & 127;
-
-    /* private key: a = n + t */
-    if (private_key) {
-        sc_muladd(private_key, SC_1, n, private_key);
-    }
-
-    /* public key: A = nB + T */
-    if (public_key) {
-        /* if we know the private key we don't need a point addition, which is faster */
-        /* using a "timing attack" you could find out wether or not we know the private
-           key, but this information seems rather useless - if this is important pass
-           public_key and private_key seperately in 2 function calls */
-        if (private_key) {
-            ge_scalarmult_base(&A, private_key);
-        } else {
-            /* unpack public key into T */
-            ge_frombytes_negate_vartime(&public_key_unpacked, public_key);
-            fe_neg(public_key_unpacked.X, public_key_unpacked.X); // undo negate
-            fe_neg(public_key_unpacked.T, public_key_unpacked.T); // undo negate
-            ge_p3_to_cached(&T, &public_key_unpacked);
-
-            /* calculate n*B */
-            ge_scalarmult_base(&nB, n);
-
-            /* A = n*B + T */
-            ge_add(&A_p1p1, &nB, &T);
-            ge_p1p1_to_p3(&A, &A_p1p1);
-        }
-            
-        /* pack public key */
-        ge_p3_tobytes(public_key, &A);
-    }
-}
diff --git a/src/ed25519/ed25519.h b/src/ed25519/ed25519.h
index bb34f893..5cb82d5d 100644
--- a/src/ed25519/ed25519.h
+++ b/src/ed25519/ed25519.h
@@ -27,7 +27,6 @@ int ED25519_DECLSPEC ed25519_create_seed(unsigned char *seed);
 void ED25519_DECLSPEC ed25519_create_keypair(unsigned char *public_key, unsigned char *private_key, const unsigned char *seed);
 void ED25519_DECLSPEC ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *public_key, const unsigned char *private_key);
 int ED25519_DECLSPEC ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *private_key);
-void ED25519_DECLSPEC ed25519_add_scalar(unsigned char *public_key, unsigned char *private_key, const unsigned char *scalar);
 void ED25519_DECLSPEC ed25519_key_exchange(unsigned char *shared_secret, const unsigned char *public_key, const unsigned char *private_key);