Qortal/pirate-librustzcash
3
0
Fork 0
mirror of https://github.com/Qortal/pirate-librustzcash.git synced 2025-02-14 10:45:47 +00:00
Code Issues Projects Releases Wiki Activity

Add 'group/' from commit 'ef56fabf7ba3ed990a7886836c855298c9c5eefa'

Browse Source 
git-subtree-dir: group
git-subtree-mainline: af9f9c17ee6179ff9cc71cfb125a2b3c9f190e48
git-subtree-split: ef56fabf7ba3ed990a7886836c855298c9c5eefa
This commit is contained in:
Jack Grigg 2019-01-06 09:38:21 +00:00
commit b1ce3905d6
9 changed files with 1073 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
group/.gitignore vendored Normal file
View File

@ -0,0 +1,3 @@
/target
**/*.rs.bk
Cargo.lock

14
group/COPYRIGHT Normal file
View File

@ -0,0 +1,14 @@
Copyrights in the "group" library are retained by their contributors. No
copyright assignment is required to contribute to the "group" library.
The "group" library is licensed under either of
* Apache License, Version 2.0, (see ./LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license (see ./LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.

17
group/Cargo.toml Normal file
View File

@ -0,0 +1,17 @@
[package]
name = "group"
version = "0.1.0"
authors = [
"Sean Bowe <ewillbefull@gmail.com>",
"Jack Grigg <jack@z.cash>",
]
license = "MIT/Apache-2.0"
description = "Elliptic curve group traits and utilities"
documentation = "https://docs.rs/group/"
homepage = "https://github.com/ebfull/group"
repository = "https://github.com/ebfull/group"
[dependencies]
ff = "0.4"
rand = "0.4"

201
group/LICENSE-APACHE Normal file
View File

@ -0,0 +1,201 @@
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright [yyyy] [name of copyright owner]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

23
group/LICENSE-MIT Normal file
View File

@ -0,0 +1,23 @@
Permission is hereby granted, free of charge, to any
person obtaining a copy of this software and associated
documentation files (the "Software"), to deal in the
Software without restriction, including without
limitation the rights to use, copy, modify, merge,
publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software
is furnished to do so, subject to the following
conditions:
The above copyright notice and this permission notice
shall be included in all copies or substantial portions
of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.

17
group/README.md Normal file
View File

@ -0,0 +1,17 @@
# group [![Crates.io](https://img.shields.io/crates/v/group.svg)](https://crates.io/crates/group) #
## License
Licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.

196
group/src/lib.rs Normal file
View File

@ -0,0 +1,196 @@
extern crate ff;
extern crate rand;
use ff::{PrimeField, PrimeFieldDecodingError, ScalarEngine, SqrtField};
use std::error::Error;
use std::fmt;
pub mod tests;
mod wnaf;
pub use self::wnaf::Wnaf;
/// Projective representation of an elliptic curve point guaranteed to be
/// in the correct prime order subgroup.
pub trait CurveProjective:
PartialEq
+ Eq
+ Sized
+ Copy
+ Clone
+ Send
+ Sync
+ fmt::Debug
+ fmt::Display
+ rand::Rand
+ 'static
{
type Engine: ScalarEngine<Fr = Self::Scalar>;
type Scalar: PrimeField + SqrtField;
type Base: SqrtField;
type Affine: CurveAffine<Projective = Self, Scalar = Self::Scalar>;
/// Returns the additive identity.
fn zero() -> Self;
/// Returns a fixed generator of unknown exponent.
fn one() -> Self;
/// Determines if this point is the point at infinity.
fn is_zero(&self) -> bool;
/// Normalizes a slice of projective elements so that
/// conversion to affine is cheap.
fn batch_normalization(v: &mut [Self]);
/// Checks if the point is already "normalized" so that
/// cheap affine conversion is possible.
fn is_normalized(&self) -> bool;
/// Doubles this element.
fn double(&mut self);
/// Adds another element to this element.
fn add_assign(&mut self, other: &Self);
/// Subtracts another element from this element.
fn sub_assign(&mut self, other: &Self) {
let mut tmp = *other;
tmp.negate();
self.add_assign(&tmp);
}
/// Adds an affine element to this element.
fn add_assign_mixed(&mut self, other: &Self::Affine);
/// Negates this element.
fn negate(&mut self);
/// Performs scalar multiplication of this element.
fn mul_assign<S: Into<<Self::Scalar as PrimeField>::Repr>>(&mut self, other: S);
/// Converts this element into its affine representation.
fn into_affine(&self) -> Self::Affine;
/// Recommends a wNAF window table size given a scalar. Always returns a number
/// between 2 and 22, inclusive.
fn recommended_wnaf_for_scalar(scalar: <Self::Scalar as PrimeField>::Repr) -> usize;
/// Recommends a wNAF window size given the number of scalars you intend to multiply
/// a base by. Always returns a number between 2 and 22, inclusive.
fn recommended_wnaf_for_num_scalars(num_scalars: usize) -> usize;
}
/// Affine representation of an elliptic curve point guaranteed to be
/// in the correct prime order subgroup.
pub trait CurveAffine:
Copy + Clone + Sized + Send + Sync + fmt::Debug + fmt::Display + PartialEq + Eq + 'static
{
type Engine: ScalarEngine<Fr = Self::Scalar>;
type Scalar: PrimeField + SqrtField;
type Base: SqrtField;
type Projective: CurveProjective<Affine = Self, Scalar = Self::Scalar>;
type Uncompressed: EncodedPoint<Affine = Self>;
type Compressed: EncodedPoint<Affine = Self>;
/// Returns the additive identity.
fn zero() -> Self;
/// Returns a fixed generator of unknown exponent.
fn one() -> Self;
/// Determines if this point represents the point at infinity; the
/// additive identity.
fn is_zero(&self) -> bool;
/// Negates this element.
fn negate(&mut self);
/// Performs scalar multiplication of this element with mixed addition.
fn mul<S: Into<<Self::Scalar as PrimeField>::Repr>>(&self, other: S) -> Self::Projective;
/// Converts this element into its affine representation.
fn into_projective(&self) -> Self::Projective;
/// Converts this element into its compressed encoding, so long as it's not
/// the point at infinity.
fn into_compressed(&self) -> Self::Compressed {
<Self::Compressed as EncodedPoint>::from_affine(*self)
}
/// Converts this element into its uncompressed encoding, so long as it's not
/// the point at infinity.
fn into_uncompressed(&self) -> Self::Uncompressed {
<Self::Uncompressed as EncodedPoint>::from_affine(*self)
}
}
/// An encoded elliptic curve point, which should essentially wrap a `[u8; N]`.
pub trait EncodedPoint:
Sized + Send + Sync + AsRef<[u8]> + AsMut<[u8]> + Clone + Copy + 'static
{
type Affine: CurveAffine;
/// Creates an empty representation.
fn empty() -> Self;
/// Returns the number of bytes consumed by this representation.
fn size() -> usize;
/// Converts an `EncodedPoint` into a `CurveAffine` element,
/// if the encoding represents a valid element.
fn into_affine(&self) -> Result<Self::Affine, GroupDecodingError>;
/// Converts an `EncodedPoint` into a `CurveAffine` element,
/// without guaranteeing that the encoding represents a valid
/// element. This is useful when the caller knows the encoding is
/// valid already.
///
/// If the encoding is invalid, this can break API invariants,
/// so caution is strongly encouraged.
fn into_affine_unchecked(&self) -> Result<Self::Affine, GroupDecodingError>;
/// Creates an `EncodedPoint` from an affine point, as long as the
/// point is not the point at infinity.
fn from_affine(affine: Self::Affine) -> Self;
}
/// An error that may occur when trying to decode an `EncodedPoint`.
#[derive(Debug)]
pub enum GroupDecodingError {
/// The coordinate(s) do not lie on the curve.
NotOnCurve,
/// The element is not part of the r-order subgroup.
NotInSubgroup,
/// One of the coordinates could not be decoded
CoordinateDecodingError(&'static str, PrimeFieldDecodingError),
/// The compression mode of the encoded element was not as expected
UnexpectedCompressionMode,
/// The encoding contained bits that should not have been set
UnexpectedInformation,
}
impl Error for GroupDecodingError {
fn description(&self) -> &str {
match *self {
GroupDecodingError::NotOnCurve => "coordinate(s) do not lie on the curve",
GroupDecodingError::NotInSubgroup => "the element is not part of an r-order subgroup",
GroupDecodingError::CoordinateDecodingError(..) => "coordinate(s) could not be decoded",
GroupDecodingError::UnexpectedCompressionMode => {
"encoding has unexpected compression mode"
}
GroupDecodingError::UnexpectedInformation => "encoding has unexpected information",
}
}
}
impl fmt::Display for GroupDecodingError {
fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
match *self {
GroupDecodingError::CoordinateDecodingError(description, ref err) => {
write!(f, "{} decoding error: {}", description, err)
}
_ => write!(f, "{}", self.description()),
}
}
}

421
group/src/tests/mod.rs Normal file
View File

@ -0,0 +1,421 @@
use rand::{Rand, Rng, SeedableRng, XorShiftRng};
use {CurveAffine, CurveProjective, EncodedPoint};
pub fn curve_tests<G: CurveProjective>() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
// Negation edge case with zero.
{
let mut z = G::zero();
z.negate();
assert!(z.is_zero());
}
// Doubling edge case with zero.
{
let mut z = G::zero();
z.double();
assert!(z.is_zero());
}
// Addition edge cases with zero
{
let mut r = G::rand(&mut rng);
let rcopy = r;
r.add_assign(&G::zero());
assert_eq!(r, rcopy);
r.add_assign_mixed(&G::Affine::zero());
assert_eq!(r, rcopy);
let mut z = G::zero();
z.add_assign(&G::zero());
assert!(z.is_zero());
z.add_assign_mixed(&G::Affine::zero());
assert!(z.is_zero());
let mut z2 = z;
z2.add_assign(&r);
z.add_assign_mixed(&r.into_affine());
assert_eq!(z, z2);
assert_eq!(z, r);
}
// Transformations
{
let a = G::rand(&mut rng);
let b = a.into_affine().into_projective();
let c = a.into_affine()
.into_projective()
.into_affine()
.into_projective();
assert_eq!(a, b);
assert_eq!(b, c);
}
random_addition_tests::<G>();
random_multiplication_tests::<G>();
random_doubling_tests::<G>();
random_negation_tests::<G>();
random_transformation_tests::<G>();
random_wnaf_tests::<G>();
random_encoding_tests::<G::Affine>();
}
fn random_wnaf_tests<G: CurveProjective>() {
use ff::PrimeField;
use wnaf::*;
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
{
let mut table = vec![];
let mut wnaf = vec![];
for w in 2..14 {
for _ in 0..100 {
let g = G::rand(&mut rng);
let s = G::Scalar::rand(&mut rng).into_repr();
let mut g1 = g;
g1.mul_assign(s);
wnaf_table(&mut table, g, w);
wnaf_form(&mut wnaf, s, w);
let g2 = wnaf_exp(&table, &wnaf);
assert_eq!(g1, g2);
}
}
}
{
fn only_compiles_if_send<S: Send>(_: &S) {}
for _ in 0..100 {
let g = G::rand(&mut rng);
let s = G::Scalar::rand(&mut rng).into_repr();
let mut g1 = g;
g1.mul_assign(s);
let g2 = {
let mut wnaf = Wnaf::new();
wnaf.base(g, 1).scalar(s)
};
let g3 = {
let mut wnaf = Wnaf::new();
wnaf.scalar(s).base(g)
};
let g4 = {
let mut wnaf = Wnaf::new();
let mut shared = wnaf.base(g, 1).shared();
only_compiles_if_send(&shared);
shared.scalar(s)
};
let g5 = {
let mut wnaf = Wnaf::new();
let mut shared = wnaf.scalar(s).shared();
only_compiles_if_send(&shared);
shared.base(g)
};
let g6 = {
let mut wnaf = Wnaf::new();
{
// Populate the vectors.
wnaf.base(rng.gen(), 1).scalar(rng.gen());
}
wnaf.base(g, 1).scalar(s)
};
let g7 = {
let mut wnaf = Wnaf::new();
{
// Populate the vectors.
wnaf.base(rng.gen(), 1).scalar(rng.gen());
}
wnaf.scalar(s).base(g)
};
let g8 = {
let mut wnaf = Wnaf::new();
{
// Populate the vectors.
wnaf.base(rng.gen(), 1).scalar(rng.gen());
}
let mut shared = wnaf.base(g, 1).shared();
only_compiles_if_send(&shared);
shared.scalar(s)
};
let g9 = {
let mut wnaf = Wnaf::new();
{
// Populate the vectors.
wnaf.base(rng.gen(), 1).scalar(rng.gen());
}
let mut shared = wnaf.scalar(s).shared();
only_compiles_if_send(&shared);
shared.base(g)
};
assert_eq!(g1, g2);
assert_eq!(g1, g3);
assert_eq!(g1, g4);
assert_eq!(g1, g5);
assert_eq!(g1, g6);
assert_eq!(g1, g7);
assert_eq!(g1, g8);
assert_eq!(g1, g9);
}
}
}
fn random_negation_tests<G: CurveProjective>() {
use ff::Field;
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
for _ in 0..1000 {
let r = G::rand(&mut rng);
let s = G::Scalar::rand(&mut rng);
let mut sneg = s;
sneg.negate();
let mut t1 = r;
t1.mul_assign(s);
let mut t2 = r;
t2.mul_assign(sneg);
let mut t3 = t1;
t3.add_assign(&t2);
assert!(t3.is_zero());
let mut t4 = t1;
t4.add_assign_mixed(&t2.into_affine());
assert!(t4.is_zero());
t1.negate();
assert_eq!(t1, t2);
}
}
fn random_doubling_tests<G: CurveProjective>() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
for _ in 0..1000 {
let mut a = G::rand(&mut rng);
let mut b = G::rand(&mut rng);
// 2(a + b)
let mut tmp1 = a;
tmp1.add_assign(&b);
tmp1.double();
// 2a + 2b
a.double();
b.double();
let mut tmp2 = a;
tmp2.add_assign(&b);
let mut tmp3 = a;
tmp3.add_assign_mixed(&b.into_affine());
assert_eq!(tmp1, tmp2);
assert_eq!(tmp1, tmp3);
}
}
fn random_multiplication_tests<G: CurveProjective>() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
for _ in 0..1000 {
let mut a = G::rand(&mut rng);
let mut b = G::rand(&mut rng);
let a_affine = a.into_affine();
let b_affine = b.into_affine();
let s = G::Scalar::rand(&mut rng);
// s ( a + b )
let mut tmp1 = a;
tmp1.add_assign(&b);
tmp1.mul_assign(s);
// sa + sb
a.mul_assign(s);
b.mul_assign(s);
let mut tmp2 = a;
tmp2.add_assign(&b);
// Affine multiplication
let mut tmp3 = a_affine.mul(s);
tmp3.add_assign(&b_affine.mul(s));
assert_eq!(tmp1, tmp2);
assert_eq!(tmp1, tmp3);
}
}
fn random_addition_tests<G: CurveProjective>() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
for _ in 0..1000 {
let a = G::rand(&mut rng);
let b = G::rand(&mut rng);
let c = G::rand(&mut rng);
let a_affine = a.into_affine();
let b_affine = b.into_affine();
let c_affine = c.into_affine();
// a + a should equal the doubling
{
let mut aplusa = a;
aplusa.add_assign(&a);
let mut aplusamixed = a;
aplusamixed.add_assign_mixed(&a.into_affine());
let mut adouble = a;
adouble.double();
assert_eq!(aplusa, adouble);
assert_eq!(aplusa, aplusamixed);
}
let mut tmp = vec![G::zero(); 6];
// (a + b) + c
tmp[0] = a;
tmp[0].add_assign(&b);
tmp[0].add_assign(&c);
// a + (b + c)
tmp[1] = b;
tmp[1].add_assign(&c);
tmp[1].add_assign(&a);
// (a + c) + b
tmp[2] = a;
tmp[2].add_assign(&c);
tmp[2].add_assign(&b);
// Mixed addition
// (a + b) + c
tmp[3] = a_affine.into_projective();
tmp[3].add_assign_mixed(&b_affine);
tmp[3].add_assign_mixed(&c_affine);
// a + (b + c)
tmp[4] = b_affine.into_projective();
tmp[4].add_assign_mixed(&c_affine);
tmp[4].add_assign_mixed(&a_affine);
// (a + c) + b
tmp[5] = a_affine.into_projective();
tmp[5].add_assign_mixed(&c_affine);
tmp[5].add_assign_mixed(&b_affine);
// Comparisons
for i in 0..6 {
for j in 0..6 {
assert_eq!(tmp[i], tmp[j]);
assert_eq!(tmp[i].into_affine(), tmp[j].into_affine());
}
assert!(tmp[i] != a);
assert!(tmp[i] != b);
assert!(tmp[i] != c);
assert!(a != tmp[i]);
assert!(b != tmp[i]);
assert!(c != tmp[i]);
}
}
}
fn random_transformation_tests<G: CurveProjective>() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
for _ in 0..1000 {
let g = G::rand(&mut rng);
let g_affine = g.into_affine();
let g_projective = g_affine.into_projective();
assert_eq!(g, g_projective);
}
// Batch normalization
for _ in 0..10 {
let mut v = (0..1000).map(|_| G::rand(&mut rng)).collect::<Vec<_>>();
for i in &v {
assert!(!i.is_normalized());
}
use rand::distributions::{IndependentSample, Range};
let between = Range::new(0, 1000);
// Sprinkle in some normalized points
for _ in 0..5 {
v[between.ind_sample(&mut rng)] = G::zero();
}
for _ in 0..5 {
let s = between.ind_sample(&mut rng);
v[s] = v[s].into_affine().into_projective();
}
let expected_v = v.iter()
.map(|v| v.into_affine().into_projective())
.collect::<Vec<_>>();
G::batch_normalization(&mut v);
for i in &v {
assert!(i.is_normalized());
}
assert_eq!(v, expected_v);
}
}
fn random_encoding_tests<G: CurveAffine>() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
assert_eq!(
G::zero().into_uncompressed().into_affine().unwrap(),
G::zero()
);
assert_eq!(
G::zero().into_compressed().into_affine().unwrap(),
G::zero()
);
for _ in 0..1000 {
let mut r = G::Projective::rand(&mut rng).into_affine();
let uncompressed = r.into_uncompressed();
let de_uncompressed = uncompressed.into_affine().unwrap();
assert_eq!(de_uncompressed, r);
let compressed = r.into_compressed();
let de_compressed = compressed.into_affine().unwrap();
assert_eq!(de_compressed, r);
r.negate();
let compressed = r.into_compressed();
let de_compressed = compressed.into_affine().unwrap();
assert_eq!(de_compressed, r);
}
}

181
group/src/wnaf.rs Normal file
View File

@ -0,0 +1,181 @@
use ff::{PrimeField, PrimeFieldRepr};
use super::CurveProjective;
/// Replaces the contents of `table` with a w-NAF window table for the given window size.
pub(crate) fn wnaf_table<G: CurveProjective>(table: &mut Vec<G>, mut base: G, window: usize) {
table.truncate(0);
table.reserve(1 << (window - 1));
let mut dbl = base;
dbl.double();
for _ in 0..(1 << (window - 1)) {
table.push(base);
base.add_assign(&dbl);
}
}
/// Replaces the contents of `wnaf` with the w-NAF representation of a scalar.
pub(crate) fn wnaf_form<S: PrimeFieldRepr>(wnaf: &mut Vec<i64>, mut c: S, window: usize) {
wnaf.truncate(0);
while !c.is_zero() {
let mut u;
if c.is_odd() {
u = (c.as_ref()[0] % (1 << (window + 1))) as i64;
if u > (1 << window) {
u -= 1 << (window + 1);
}
if u > 0 {
c.sub_noborrow(&S::from(u as u64));
} else {
c.add_nocarry(&S::from((-u) as u64));
}
} else {
u = 0;
}
wnaf.push(u);
c.div2();
}
}
/// Performs w-NAF exponentiation with the provided window table and w-NAF form scalar.
///
/// This function must be provided a `table` and `wnaf` that were constructed with
/// the same window size; otherwise, it may panic or produce invalid results.
pub(crate) fn wnaf_exp<G: CurveProjective>(table: &[G], wnaf: &[i64]) -> G {
let mut result = G::zero();
let mut found_one = false;
for n in wnaf.iter().rev() {
if found_one {
result.double();
}
if *n != 0 {
found_one = true;
if *n > 0 {
result.add_assign(&table[(n / 2) as usize]);
} else {
result.sub_assign(&table[((-n) / 2) as usize]);
}
}
}
result
}
/// A "w-ary non-adjacent form" exponentiation context.
#[derive(Debug)]
pub struct Wnaf<W, B, S> {
base: B,
scalar: S,
window_size: W,
}
impl<G: CurveProjective> Wnaf<(), Vec<G>, Vec<i64>> {
/// Construct a new wNAF context without allocating.
pub fn new() -> Self {
Wnaf {
base: vec![],
scalar: vec![],
window_size: (),
}
}
/// Given a base and a number of scalars, compute a window table and return a `Wnaf` object that
/// can perform exponentiations with `.scalar(..)`.
pub fn base(&mut self, base: G, num_scalars: usize) -> Wnaf<usize, &[G], &mut Vec<i64>> {
// Compute the appropriate window size based on the number of scalars.
let window_size = G::recommended_wnaf_for_num_scalars(num_scalars);
// Compute a wNAF table for the provided base and window size.
wnaf_table(&mut self.base, base, window_size);
// Return a Wnaf object that immutably borrows the computed base storage location,
// but mutably borrows the scalar storage location.
Wnaf {
base: &self.base[..],
scalar: &mut self.scalar,
window_size,
}
}
/// Given a scalar, compute its wNAF representation and return a `Wnaf` object that can perform
/// exponentiations with `.base(..)`.
pub fn scalar(
&mut self,
scalar: <<G as CurveProjective>::Scalar as PrimeField>::Repr,
) -> Wnaf<usize, &mut Vec<G>, &[i64]> {
// Compute the appropriate window size for the scalar.
let window_size = G::recommended_wnaf_for_scalar(scalar);
// Compute the wNAF form of the scalar.
wnaf_form(&mut self.scalar, scalar, window_size);
// Return a Wnaf object that mutably borrows the base storage location, but
// immutably borrows the computed wNAF form scalar location.
Wnaf {
base: &mut self.base,
scalar: &self.scalar[..],
window_size,
}
}
}
impl<'a, G: CurveProjective> Wnaf<usize, &'a [G], &'a mut Vec<i64>> {
/// Constructs new space for the scalar representation while borrowing
/// the computed window table, for sending the window table across threads.
pub fn shared(&self) -> Wnaf<usize, &'a [G], Vec<i64>> {
Wnaf {
base: self.base,
scalar: vec![],
window_size: self.window_size,
}
}
}
impl<'a, G: CurveProjective> Wnaf<usize, &'a mut Vec<G>, &'a [i64]> {
/// Constructs new space for the window table while borrowing
/// the computed scalar representation, for sending the scalar representation
/// across threads.
pub fn shared(&self) -> Wnaf<usize, Vec<G>, &'a [i64]> {
Wnaf {
base: vec![],
scalar: self.scalar,
window_size: self.window_size,
}
}
}
impl<B, S: AsRef<[i64]>> Wnaf<usize, B, S> {
/// Performs exponentiation given a base.
pub fn base<G: CurveProjective>(&mut self, base: G) -> G
where
B: AsMut<Vec<G>>,
{
wnaf_table(self.base.as_mut(), base, self.window_size);
wnaf_exp(self.base.as_mut(), self.scalar.as_ref())
}
}
impl<B, S: AsMut<Vec<i64>>> Wnaf<usize, B, S> {
/// Performs exponentiation given a scalar.
pub fn scalar<G: CurveProjective>(
&mut self,
scalar: <<G as CurveProjective>::Scalar as PrimeField>::Repr,
) -> G
where
B: AsRef<[G]>,
{
wnaf_form(self.scalar.as_mut(), scalar, self.window_size);
wnaf_exp(self.base.as_ref(), self.scalar.as_mut())
}
}