Commit eaca8626b270b5c17d686c77220e2aacb5fd908f | zig

author	Frank Denis <124872+jedisct1@users.noreply.github.com> 2024-03-11 09:00:15+01:00
committer	GitHub <noreply@github.com> 2024-03-11 09:00:15+01:00
log	eaca8626b270b5c17d686c77220e2aacb5fd908f
tree	11195fb7cb36c4bf648eff2737a42aad4161118d
parent	40e64245fc5555f29bbb5bb37e3b78d64f9b3c9b
signature	Signed by PGP key B5690EEEBB952194

std.crypto.pcurves fixes (#19245)

Fixes compilation errors in functions that are syntaxic sugar
to operate on serialized scalars.

Also make it explicit that square roots in fields whose size is
not congruent to 3 modulo 4 are not an error, they are just
not implemented yet.

Reported by @vitalonodo - Thanks!

5 files changed, 8 insertions(+), 8 deletions(-)

lib
- std
  - crypto
    pcurves
    common.zig
    p256
    scalar.zig
    p384
    scalar.zig
    secp256k1.zig
    secp256k1
    scalar.zig

lib/std/crypto/pcurves/common.zig+1-1

...	...	@@ -277,7 +277,7 @@ pub fn Field(comptime params: FieldParams) type {
277	277
278	278	// x=x2^((field_order+1)/4) w/ field order=3 (mod 4).
279	279	fn uncheckedSqrt(x2: Fe) Fe {
280		comptime debug.assert(field_order % 4 == 3);
	280	if (field_order % 4 != 3) @compileError("unimplemented");
281	281	if (field_order == 115792089210356248762697446949407573530086143415290314195533631308867097853951) {
282	282	const t11 = x2.mul(x2.sq());
283	283	const t1111 = t11.mul(t11.sqn(2));

lib/std/crypto/pcurves/p256/scalar.zig+2-2

...	...	@@ -39,7 +39,7 @@ pub fn reduce48(s: [48]u8, endian: std.builtin.Endian) CompressedScalar {
39	39
40	40	/// Reduce a 64-bytes scalar to the field size.
41	41	pub fn reduce64(s: [64]u8, endian: std.builtin.Endian) CompressedScalar {
42		return ScalarDouble.fromBytes64(s, endian).toBytes(endian);
	42	return Scalar.fromBytes64(s, endian).toBytes(endian);
43	43	}
44	44
45	45	/// Return a*b (mod L)
...	...	@@ -160,7 +160,7 @@ pub const Scalar = struct {
160	160	}
161	161
162	162	/// Return true if n is a quadratic residue mod L.
163		pub fn isSquare(n: Scalar) Scalar {
	163	pub fn isSquare(n: Scalar) bool {
164	164	return n.fe.isSquare();
165	165	}
166	166

lib/std/crypto/pcurves/p384/scalar.zig+2-2

...	...	@@ -34,7 +34,7 @@ pub fn rejectNonCanonical(s: CompressedScalar, endian: std.builtin.Endian) NonCa
34	34
35	35	/// Reduce a 64-bytes scalar to the field size.
36	36	pub fn reduce64(s: [64]u8, endian: std.builtin.Endian) CompressedScalar {
37		return ScalarDouble.fromBytes64(s, endian).toBytes(endian);
	37	return Scalar.fromBytes64(s, endian).toBytes(endian);
38	38	}
39	39
40	40	/// Return a*b (mod L)
...	...	@@ -149,7 +149,7 @@ pub const Scalar = struct {
149	149	}
150	150
151	151	/// Return true if n is a quadratic residue mod L.
152		pub fn isSquare(n: Scalar) Scalar {
	152	pub fn isSquare(n: Scalar) bool {
153	153	return n.fe.isSquare();
154	154	}
155	155

lib/std/crypto/pcurves/secp256k1.zig+1-1

...	...	@@ -221,7 +221,7 @@ pub const Secp256k1 = struct {
221	221	var t0 = p.x.mul(q.x);
222	222	var t1 = p.y.mul(q.y);
223	223	var t3 = q.x.add(q.y);
224		var t4 = p.x.add(p.y1);
	224	var t4 = p.x.add(p.y);
225	225	t3 = t3.mul(t4);
226	226	t4 = t0.add(t1);
227	227	t3 = t3.sub(t4);

lib/std/crypto/pcurves/secp256k1/scalar.zig+2-2

...	...	@@ -39,7 +39,7 @@ pub fn reduce48(s: [48]u8, endian: std.builtin.Endian) CompressedScalar {
39	39
40	40	/// Reduce a 64-bytes scalar to the field size.
41	41	pub fn reduce64(s: [64]u8, endian: std.builtin.Endian) CompressedScalar {
42		return ScalarDouble.fromBytes64(s, endian).toBytes(endian);
	42	return Scalar.fromBytes64(s, endian).toBytes(endian);
43	43	}
44	44
45	45	/// Return a*b (mod L)
...	...	@@ -160,7 +160,7 @@ pub const Scalar = struct {
160	160	}
161	161
162	162	/// Return true if n is a quadratic residue mod L.
163		pub fn isSquare(n: Scalar) Scalar {
	163	pub fn isSquare(n: Scalar) bool {
164	164	return n.fe.isSquare();
165	165	}
166	166