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tls: shrink p256_base

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function                                             old     new   delta
curve_P256_compute_pubkey_and_premaster              196     291     +95
static.base_y                                          -      40     +40
static.base_x                                          -      40     +40
p256_base                                            244       -    -244
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 1/0 up/down: 175/-244)          Total: -69 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2021-04-27 01:31:51 +02:00
parent a2bc52dd44
commit 39a3ef51b5
1 changed files with 18 additions and 12 deletions
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30
networking/tls_sp_c32.c
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@ -72,18 +72,6 @@ static const sp_digit p256_mod[10] = {
#define p256_mp_mod ((sp_digit)0x000001)
/* The base point of curve P256. */
static const sp_point p256_base = {
/* X ordinate */
{ 0x098c296,0x04e5176,0x33a0f4a,0x204b7ac,0x277037d,0x0e9103c,0x3ce6e56,0x1091fe2,0x1f2e12c,0x01ac5f4 },
/* Y ordinate */
{ 0x3bf51f5,0x1901a0d,0x1ececbb,0x15dacc5,0x22bce33,0x303e785,0x27eb4a7,0x1fe6e3b,0x2e2fe1a,0x013f8d0 },
/* Z ordinate */
{ 0x0000001,0x0000000,0x0000000,0x0000000,0x0000000,0x0000000,0x0000000,0x0000000,0x0000000,0x0000000 },
/* infinity */
0
};
/* Write r as big endian to byte aray.
* Fixed length number of bytes written: 32
*
@ -798,6 +786,24 @@ static void sp_256_ecc_mulmod_10(sp_point* r, const sp_point* g, const sp_digit*
*/
static void sp_256_ecc_mulmod_base_10(sp_point* r, sp_digit* k /*, int map*/)
{
/* Since this function is called only once, save space:
* don't have "static const sp_point p256_base = {...}",
* it would have more zeros than data.
*/
static const sp_digit base_x[] = {
0x098c296,0x04e5176,0x33a0f4a,0x204b7ac,0x277037d,0x0e9103c,0x3ce6e56,0x1091fe2,0x1f2e12c,0x01ac5f4
};
static const sp_digit base_y[] = {
0x3bf51f5,0x1901a0d,0x1ececbb,0x15dacc5,0x22bce33,0x303e785,0x27eb4a7,0x1fe6e3b,0x2e2fe1a,0x013f8d0
};
sp_point p256_base;
memset(&p256_base, 0, sizeof(p256_base));
memcpy(p256_base.x, base_x, sizeof(base_x));
memcpy(p256_base.y, base_y, sizeof(base_y));
p256_base.z[0] = 1;
/*p256_base.infinity = 0;*/
sp_256_ecc_mulmod_10(r, &p256_base, k /*, map*/);
}