Commit 6af9bc8c686c5eeaff274fa7ebb96b1ead3212ce | zig

author	Frank Denis <124872+jedisct1@users.noreply.github.com> 2020-08-14 16:33:37+02:00
committer	Andrew Kelley <andrew@ziglang.org> 2020-08-16 22:35:27-07:00
log	6af9bc8c686c5eeaff274fa7ebb96b1ead3212ce
tree	511f9171ac6d965329e316275b43c4f58ab1bb32
parent	5f9953f41ff7761cdf86c211c91de7470425771c

Initialize structures directly

Suggested by @kubkon, thanks!

3 files changed, 7 insertions(+), 13 deletions(-)

lib
- std
  - crypto
    25519
    curve25519.zig
    edwards25519.zig
    ristretto255.zig

lib/std/crypto/25519/curve25519.zig+1-1

...	...	@@ -76,7 +76,7 @@ pub const Curve25519 = struct {
76	76	if (x2.isZero()) {
77	77	return error.IdentityElement;
78	78	}
79		return @as(Curve25519, .{ .x = x2 });
	79	return Curve25519 { .x = x2 };
80	80	}
81	81
82	82	/// Multiply a Curve25519 point by a scalar after "clamping" it.

lib/std/crypto/25519/edwards25519.zig+1-1

...	...	@@ -34,7 +34,7 @@ pub const Edwards25519 = struct {
34	34	x.cMov(x.mul(Fe.sqrtm1()), 1 - @boolToInt(has_m_root));
35	35	x.cMov(x.neg(), @boolToInt(x.isNegative()) ^ (s[31] >> 7));
36	36	const t = x.mul(y);
37		return @as(Edwards25519, .{ .x = x, .y = y, .z = z, .t = t });
	37	return Edwards25519 { .x = x, .y = y, .z = z, .t = t };
38	38	}
39	39
40	40	/// Encode an Edwards25519 point.

lib/std/crypto/25519/ristretto255.zig+5-11

...	...	@@ -13,9 +13,8 @@ pub const Ristretto255 = struct {
13	13	p: Curve = undefined,
14	14
15	15	fn sqrtRatioM1(u: Fe, v: Fe) !Fe {
16		const v3 = v.sq().mul(v); // v3 = v^3
17		var x = v3.sq().mul(u).mul(v). // x = uv^7
18		pow2523().mul(v3).mul(u); // x = uv^3(uv^7)^((q-5)/8)
	16	const v3 = v.sq().mul(v); // v^3
	17	var x = v3.sq().mul(u).mul(v).pow2523().mul(v3).mul(u); // uv^3(uv^7)^((q-5)/8)
19	18	const vxx = x.sq().mul(v); // vx^2
20	19	const m_root_check = vxx.sub(u); // vx^2-u
21	20	const p_root_check = vxx.add(u); // vx^2+u
...	...	@@ -77,7 +76,7 @@ pub const Ristretto255 = struct {
77	76	.z = Fe.one(),
78	77	.t = t,
79	78	};
80		return @as(Ristretto255, .{ .p = p });
	79	return Ristretto255 { .p = p };
81	80	}
82	81
83	82	/// Encode to a Ristretto255 representative.
...	...	@@ -87,25 +86,20 @@ pub const Ristretto255 = struct {
87	86	const zmy = p.z.sub(p.y); // Z-Y
88	87	u1_ = u1_.mul(zmy); // (Z+Y)*(Z-Y)
89	88	const u2_ = p.x.mul(p.y); // X*Y
90
91	89	const u1_u2u2 = u2_.sq().mul(u1_); // u1*u2^2
92
93	90	const inv_sqrt = sqrtRatioM1(Fe.one(), u1_u2u2) catch unreachable;
94	91	const den1 = inv_sqrt.mul(u1_);
95	92	const den2 = inv_sqrt.mul(u2_);
96	93	const z_inv = den1.mul(den2).mul(p.t); // den1den2T
97
98	94	const ix = p.x.mul(Fe.sqrtm1()); // X*sqrt(-1)
99	95	const iy = p.y.mul(Fe.sqrtm1()); // Y*sqrt(-1)
100	96	const eden = den1.mul(Fe.edwards25519sqrtamd()); // den1/sqrt(a-d)
101
102	97	const t_z_inv = p.t.mul(z_inv); // T*z_inv
103		const rotate = @boolToInt(t_z_inv.isNegative());
104	98
	99	const rotate = @boolToInt(t_z_inv.isNegative());
105	100	var x = p.x;
106	101	var y = p.y;
107	102	var den_inv = den2;
108
109	103	x.cMov(iy, rotate);
110	104	y.cMov(ix, rotate);
111	105	den_inv.cMov(eden, rotate);
...	...	@@ -131,7 +125,7 @@ pub const Ristretto255 = struct {
131	125	/// Return error.WeakPublicKey if the resulting element is
132	126	/// the identity element.
133	127	pub inline fn mul(p: Ristretto255, s: [32]u8) !Ristretto255 {
134		return @as(Ristretto255, .{ .p = try p.p.mul(s) });
	128	return Ristretto255 { .p = try p.p.mul(s) };
135	129	}
136	130	};
137	131