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Tidy up curve25519_ref10, remove comments that are not relevant any more

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This commit is contained in:
Frank Denis 2017-10-31 20:22:48 +01:00
parent a3f96045d4
commit a366ea0839
1 changed files with 93 additions and 167 deletions
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260
src/libsodium/crypto_core/curve25519/ref10/curve25519_ref10.c
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@ -69,38 +69,90 @@ fe_1(fe h)
void void
fe_add(fe h, const fe f, const fe g) fe_add(fe h, const fe f, const fe g)
{ {
int32_t f0 = f[0]; int32_t h0 = f[0] + g[0];
int32_t f1 = f[1]; int32_t h1 = f[1] + g[1];
int32_t f2 = f[2]; int32_t h2 = f[2] + g[2];
int32_t f3 = f[3]; int32_t h3 = f[3] + g[3];
int32_t f4 = f[4]; int32_t h4 = f[4] + g[4];
int32_t f5 = f[5]; int32_t h5 = f[5] + g[5];
int32_t f6 = f[6]; int32_t h6 = f[6] + g[6];
int32_t f7 = f[7]; int32_t h7 = f[7] + g[7];
int32_t f8 = f[8]; int32_t h8 = f[8] + g[8];
int32_t f9 = f[9]; int32_t h9 = f[9] + g[9];
int32_t g0 = g[0]; h[0] = h0;
int32_t g1 = g[1]; h[1] = h1;
int32_t g2 = g[2]; h[2] = h2;
int32_t g3 = g[3]; h[3] = h3;
int32_t g4 = g[4]; h[4] = h4;
int32_t g5 = g[5]; h[5] = h5;
int32_t g6 = g[6]; h[6] = h6;
int32_t g7 = g[7]; h[7] = h7;
int32_t g8 = g[8]; h[8] = h8;
int32_t g9 = g[9]; h[9] = h9;
}
int32_t h0 = f0 + g0; /*
int32_t h1 = f1 + g1; h = f - g
int32_t h2 = f2 + g2; Can overlap h with f or g.
int32_t h3 = f3 + g3; *
int32_t h4 = f4 + g4; Preconditions:
int32_t h5 = f5 + g5; |f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
int32_t h6 = f6 + g6; |g| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
int32_t h7 = f7 + g7; *
int32_t h8 = f8 + g8; Postconditions:
int32_t h9 = f9 + g9; |h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
*/
void
fe_sub(fe h, const fe f, const fe g)
{
int32_t h0 = f[0] - g[0];
int32_t h1 = f[1] - g[1];
int32_t h2 = f[2] - g[2];
int32_t h3 = f[3] - g[3];
int32_t h4 = f[4] - g[4];
int32_t h5 = f[5] - g[5];
int32_t h6 = f[6] - g[6];
int32_t h7 = f[7] - g[7];
int32_t h8 = f[8] - g[8];
int32_t h9 = f[9] - g[9];
h[0] = h0;
h[1] = h1;
h[2] = h2;
h[3] = h3;
h[4] = h4;
h[5] = h5;
h[6] = h6;
h[7] = h7;
h[8] = h8;
h[9] = h9;
}
/*
h = -f
*
Preconditions:
|f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
*
Postconditions:
|h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
*/
static void
fe_neg(fe h, const fe f)
{
int32_t h0 = -f[0];
int32_t h1 = -f[1];
int32_t h2 = -f[2];
int32_t h3 = -f[3];
int32_t h4 = -f[4];
int32_t h5 = -f[5];
int32_t h6 = -f[6];
int32_t h7 = -f[7];
int32_t h8 = -f[8];
int32_t h9 = -f[9];
h[0] = h0; h[0] = h0;
h[1] = h1; h[1] = h1;
@ -135,27 +187,16 @@ fe_cmov(fe f, const fe g, unsigned int b)
int32_t f8 = f[8]; int32_t f8 = f[8];
int32_t f9 = f[9]; int32_t f9 = f[9];
int32_t g0 = g[0]; int32_t x0 = f0 ^ g[0];
int32_t g1 = g[1]; int32_t x1 = f1 ^ g[1];
int32_t g2 = g[2]; int32_t x2 = f2 ^ g[2];
int32_t g3 = g[3]; int32_t x3 = f3 ^ g[3];
int32_t g4 = g[4]; int32_t x4 = f4 ^ g[4];
int32_t g5 = g[5]; int32_t x5 = f5 ^ g[5];
int32_t g6 = g[6]; int32_t x6 = f6 ^ g[6];
int32_t g7 = g[7]; int32_t x7 = f7 ^ g[7];
int32_t g8 = g[8]; int32_t x8 = f8 ^ g[8];
int32_t g9 = g[9]; int32_t x9 = f9 ^ g[9];
int32_t x0 = f0 ^ g0;
int32_t x1 = f1 ^ g1;
int32_t x2 = f2 ^ g2;
int32_t x3 = f3 ^ g3;
int32_t x4 = f4 ^ g4;
int32_t x5 = f5 ^ g5;
int32_t x6 = f6 ^ g6;
int32_t x7 = f7 ^ g7;
int32_t x8 = f8 ^ g8;
int32_t x9 = f9 ^ g9;
b = (unsigned int) (-(int) b); b = (unsigned int) (-(int) b);
x0 &= b; x0 &= b;
@ -749,53 +790,6 @@ fe_mul(fe h, const fe f, const fe g)
h[9] = (int32_t) h9; h[9] = (int32_t) h9;
} }
/*
h = -f
*
Preconditions:
|f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
*
Postconditions:
|h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
*/
static void
fe_neg(fe h, const fe f)
{
int32_t f0 = f[0];
int32_t f1 = f[1];
int32_t f2 = f[2];
int32_t f3 = f[3];
int32_t f4 = f[4];
int32_t f5 = f[5];
int32_t f6 = f[6];
int32_t f7 = f[7];
int32_t f8 = f[8];
int32_t f9 = f[9];
int32_t h0 = -f0;
int32_t h1 = -f1;
int32_t h2 = -f2;
int32_t h3 = -f3;
int32_t h4 = -f4;
int32_t h5 = -f5;
int32_t h6 = -f6;
int32_t h7 = -f7;
int32_t h8 = -f8;
int32_t h9 = -f9;
h[0] = h0;
h[1] = h1;
h[2] = h2;
h[3] = h3;
h[4] = h4;
h[5] = h5;
h[6] = h6;
h[7] = h7;
h[8] = h8;
h[9] = h9;
}
/* /*
h = f * f h = f * f
Can overlap h with f. Can overlap h with f.
@ -807,10 +801,6 @@ fe_neg(fe h, const fe f)
|h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc. |h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
*/ */
/*
See fe_mul.c for discussion of implementation strategy.
*/
void void
fe_sq(fe h, const fe f) fe_sq(fe h, const fe f)
{ {
@ -983,10 +973,6 @@ fe_sq(fe h, const fe f)
|h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc. |h| bounded by 1.01*2^25,1.01*2^24,1.01*2^25,1.01*2^24,etc.
*/ */
/*
See fe_mul.c for discussion of implementation strategy.
*/
static void static void
fe_sq2(fe h, const fe f) fe_sq2(fe h, const fe f)
{ {
@ -1272,65 +1258,6 @@ fe_pow22523(fe out, const fe z)
fe_mul(out, t0, z); fe_mul(out, t0, z);
} }
/*
h = f - g
Can overlap h with f or g.
*
Preconditions:
|f| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
|g| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
*
Postconditions:
|h| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
*/
void
fe_sub(fe h, const fe f, const fe g)
{
int32_t f0 = f[0];
int32_t f1 = f[1];
int32_t f2 = f[2];
int32_t f3 = f[3];
int32_t f4 = f[4];
int32_t f5 = f[5];
int32_t f6 = f[6];
int32_t f7 = f[7];
int32_t f8 = f[8];
int32_t f9 = f[9];
int32_t g0 = g[0];
int32_t g1 = g[1];
int32_t g2 = g[2];
int32_t g3 = g[3];
int32_t g4 = g[4];
int32_t g5 = g[5];
int32_t g6 = g[6];
int32_t g7 = g[7];
int32_t g8 = g[8];
int32_t g9 = g[9];
int32_t h0 = f0 - g0;
int32_t h1 = f1 - g1;
int32_t h2 = f2 - g2;
int32_t h3 = f3 - g3;
int32_t h4 = f4 - g4;
int32_t h5 = f5 - g5;
int32_t h6 = f6 - g6;
int32_t h7 = f7 - g7;
int32_t h8 = f8 - g8;
int32_t h9 = f9 - g9;
h[0] = h0;
h[1] = h1;
h[2] = h2;
h[3] = h3;
h[4] = h4;
h[5] = h5;
h[6] = h6;
h[7] = h7;
h[8] = h8;
h[9] = h9;
}
/* /*
r = p + q r = p + q
*/ */
@ -1395,8 +1322,7 @@ slide_vartime(signed char *r, const unsigned char *a)
} }
} }
/* 37095705934669439343138083508754565189542113879843219016388785533085940283555 /* 37095705934669439343138083508754565189542113879843219016388785533085940283555 */
*/
static const fe d = { -10913610, 13857413, -15372611, 6949391, 114729, static const fe d = { -10913610, 13857413, -15372611, 6949391, 114729,
-8787816, -6275908, -3247719, -18696448, -12055116 }; -8787816, -6275908, -3247719, -18696448, -12055116 };