tls: code shrink

function                                             old     new   delta
static.f25519_one                                     32       -     -32
curve25519                                           835     802     -33
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 0/1 up/down: 0/-65)             Total: -65 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 21 insertions, 11 deletions

diff --git a/networking/tls_fe.c b/networking/tls_fe.c
index 37fea34f7..dcb41468a 100644
--- a/networking/tls_fe.c
+++ b/networking/tls_fe.c
@@ -556,19 +556,29 @@ static void xc_double(byte *x3, byte *z3,
 
 void curve25519(byte *result, const byte *e, const byte *q)
 {
-        /* from wolfssl-3.15.3/wolfssl/wolfcrypt/fe_operations.h */
-        static const byte f25519_one[F25519_SIZE] = {1};
-
-        /* Current point: P_m */
-        byte xm[F25519_SIZE];
-        byte zm[F25519_SIZE] = {1};
-
-        /* Predecessor: P_(m-1) */
-        byte xm1[F25519_SIZE] = {1};
-        byte zm1[F25519_SIZE] = {0};
-
         int i;
 
+        struct {
+                /* from wolfssl-3.15.3/wolfssl/wolfcrypt/fe_operations.h */
+                /*static const*/ byte f25519_one[F25519_SIZE]; // = {1};
+
+                /* Current point: P_m */
+                byte xm[F25519_SIZE];
+                byte zm[F25519_SIZE]; // = {1};
+                /* Predecessor: P_(m-1) */
+                byte xm1[F25519_SIZE]; // = {1};
+                byte zm1[F25519_SIZE]; // = {0};
+        } z;
+#define f25519_one z.f25519_one
+#define xm         z.xm
+#define zm         z.zm
+#define xm1        z.xm1
+#define zm1        z.zm1
+        memset(&z, 0, sizeof(z));
+        f25519_one[0] = 1;
+        zm[0] = 1;
+        xm1[0] = 1;
+
         /* Note: bit 254 is assumed to be 1 */
         lm_copy(xm, q);