Browse Source

Add GHA (tests & lint), add descr, update readme

pull/1/head
arnaucube 3 years ago
parent
commit
c7b358b28c
5 changed files with 110 additions and 28 deletions
  1. +16
    -0
      .github/workflows/lint.yml
  2. +19
    -0
      .github/workflows/test.yml
  3. +17
    -0
      .golangci.yml
  4. +3
    -2
      README.md
  5. +55
    -26
      blindsecp256k1.go

+ 16
- 0
.github/workflows/lint.yml

@ -0,0 +1,16 @@
name: Lint
on: [ push, pull_request ]
jobs:
lint:
runs-on: ubuntu-latest
steps:
- name: Install Go
uses: actions/setup-go@v1
with:
go-version: 1.14.x
- name: Checkout code
uses: actions/checkout@v2
- name: Lint
run: |
curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.30.0
$(go env GOPATH)/bin/golangci-lint run --timeout=5m -c .golangci.yml

+ 19
- 0
.github/workflows/test.yml

@ -0,0 +1,19 @@
name: Test
on: [push, pull_request]
jobs:
test:
# matrix strategy from: https://github.com/mvdan/github-actions-golang/blob/master/.github/workflows/test.yml
strategy:
matrix:
go-version: [1.13.x, 1.14.x]
platform: [ubuntu-latest]
runs-on: ${{ matrix.platform }}
steps:
- name: Install Go
uses: actions/setup-go@v1
with:
go-version: ${{ matrix.go-version }}
- name: Checkout code
uses: actions/checkout@v2
- name: Run tests
run: go test ./...

+ 17
- 0
.golangci.yml

@ -0,0 +1,17 @@
issues:
max-same-issues: 0
exclude-use-default: false
linters:
enable:
- whitespace
- gosec
- gci
- misspell
- gomnd
- gofmt
- goimports
- lll
- golint
linters-settings:
lll:
line-length: 100

+ 3
- 2
README.md

@ -1,5 +1,6 @@
# go-blindsecp256k1
Blind signature over [secp256k1](https://en.bitcoin.it/wiki/Secp256k1), based on *"[An Efficient Blind Signature Scheme Based on the Elliptic CurveDiscrete Logarithm Problem](http://www.isecure-journal.com/article_39171_47f9ec605dd3918c2793565ec21fcd7a.pdf)"* paper.
# go-blindsecp256k1 [![GoDoc](https://godoc.org/github.com/arnaucube/go-blindsecp256k1?status.svg)](https://godoc.org/github.com/arnaucube/go-blindsecp256k1) [![Go Report Card](https://goreportcard.com/badge/github.com/arnaucube/go-blindsecp256k1)](https://goreportcard.com/report/github.com/arnaucube/go-blindsecp256k1) [![Test](https://github.com/arnaucube/go-blindsecp256k1/workflows/Test/badge.svg)](https://github.com/arnaucube/go-blindsecp256k1/actions?query=workflow%3ATest)
Blind signature over [secp256k1](https://en.bitcoin.it/wiki/Secp256k1), based on *"[An Efficient Blind Signature Scheme Based on the Elliptic Curve Discrete Logarithm Problem](http://www.isecure-journal.com/article_39171_47f9ec605dd3918c2793565ec21fcd7a.pdf)"* paper.
**WARNING**: this repo is experimental, do not use in production.

+ 55
- 26
blindsecp256k1.go

@ -2,6 +2,7 @@
// http://www.isecure-journal.com/article_39171_47f9ec605dd3918c2793565ec21fcd7a.pdf
//
// LICENSE can be found at https://github.com/arnaucube/go-blindsecp256k1/blob/master/LICENSE
//
package blindsecp256k1
// WARNING: WIP code
@ -14,20 +15,24 @@ import (
"github.com/ethereum/go-ethereum/crypto/secp256k1"
)
type Point struct {
X *big.Int
Y *big.Int
}
var (
// G represents the base point of secp256k1
G *Point = &Point{
X: secp256k1.S256().Gx,
Y: secp256k1.S256().Gy,
}
// N represents the order of G of secp256k1
N *big.Int = secp256k1.S256().N
)
// Point represents a point on the secp256k1 curve
type Point struct {
X *big.Int
Y *big.Int
}
// Add performs the Point addition
func (p *Point) Add(q *Point) *Point {
x, y := secp256k1.S256().Add(p.X, p.Y, q.X, q.Y)
return &Point{
@ -36,6 +41,7 @@ func (p *Point) Add(q *Point) *Point {
}
}
// Mul performs the Point scalar multiplication
func (p *Point) Mul(scalar *big.Int) *Point {
x, y := secp256k1.S256().ScalarMult(p.X, p.Y, scalar.Bytes())
return &Point{
@ -44,6 +50,7 @@ func (p *Point) Mul(scalar *big.Int) *Point {
}
}
// WIP
func newRand() *big.Int {
var b [32]byte
_, err := rand.Read(b[:])
@ -54,108 +61,129 @@ func newRand() *big.Int {
return new(big.Int).Mod(bi, N)
}
// PrivateKey represents the signer's private key
type PrivateKey big.Int
// PublicKey represents the signer's public key
type PublicKey Point
// NewPrivateKey returns a new random private key
func NewPrivateKey() *PrivateKey {
k := newRand()
sk := PrivateKey(*k)
return &sk
}
// BigInt returns a *big.Int representation of the PrivateKey
func (sk *PrivateKey) BigInt() *big.Int {
return (*big.Int)(sk)
}
// Public returns the PublicKey from the PrivateKey
func (sk *PrivateKey) Public() *PublicKey {
Q := G.Mul(sk.BigInt())
pk := PublicKey(*Q)
return &pk
}
// Point returns a *Point representation of the PublicKey
func (pk *PublicKey) Point() *Point {
return (*Point)(pk)
}
// SignerPrivateData contains the secret values from the Signer
type SignerPrivateData struct {
d *PrivateKey
k *big.Int
D *PrivateKey
K *big.Int
}
// SignerPublicData contains the public values from the Signer (generated from
// its SignerPrivateData)
type SignerPublicData struct {
// Q is the Signer Public Key
Q *PublicKey // = skG
R *Point // = kG
}
// NewSigner returns a new SignerPrivateData with random D & K
func NewSigner() *SignerPrivateData {
sk := NewPrivateKey()
k := newRand()
return &SignerPrivateData{
d: sk,
k: k,
D: sk,
K: k,
}
}
// PublicData returns the SignerPublicData from the SignerPrivateData
func (signer *SignerPrivateData) PublicData() *SignerPublicData {
return &SignerPublicData{
Q: signer.d.Public(), // Q = dG
R: G.Mul(signer.k), // R = kG
Q: signer.D.Public(), // Q = dG
R: G.Mul(signer.K), // R = kG
}
}
// BlindSign performs the blind signature on the given mBlinded using
// SignerPrivateData values
func (signer *SignerPrivateData) BlindSign(mBlinded *big.Int) *big.Int {
// TODO add pending checks
// s' = d(m') + k
sBlind := new(big.Int).Add(
new(big.Int).Mul(signer.d.BigInt(), mBlinded),
signer.k)
new(big.Int).Mul(signer.D.BigInt(), mBlinded),
signer.K)
return sBlind
}
// UserSecretData contains the secret values from the User (a, b, c) and the
// public F
type UserSecretData struct {
a *big.Int
b *big.Int
c *big.Int
A *big.Int
B *big.Int
C *big.Int
F *Point // public
}
// Blind performs the blinding operation on m using SignerPublicData parameters
func Blind(m *big.Int, signer *SignerPublicData) (*big.Int, *UserSecretData) {
u := &UserSecretData{}
u.a = newRand()
u.b = newRand()
u.c = newRand()
binv := new(big.Int).ModInverse(u.b, N)
u.A = newRand()
u.B = newRand()
u.C = newRand()
binv := new(big.Int).ModInverse(u.B, N)
// F = b^-1 R + a b^-1 Q + c G
bR := signer.R.Mul(binv)
abinv := new(big.Int).Mul(u.a, binv)
abinv := new(big.Int).Mul(u.A, binv)
abinv = new(big.Int).Mod(abinv, N)
abQ := signer.Q.Point().Mul(abinv)
cG := G.Mul(u.c)
cG := G.Mul(u.C)
u.F = bR.Add(abQ).Add(cG)
// TODO check F==O
r := new(big.Int).Mod(u.F.X, N)
// m' = br(m)+a
br := new(big.Int).Mul(u.b, r)
br := new(big.Int).Mul(u.B, r)
brm := new(big.Int).Mul(br, m)
mBlinded := new(big.Int).Add(brm, u.a)
mBlinded := new(big.Int).Add(brm, u.A)
mBlinded = new(big.Int).Mod(mBlinded, N)
return mBlinded, u
}
// Signature contains the signature values S & F
type Signature struct {
S *big.Int
F *Point
}
// Unblind performs the unblinding operation of the blinded signature for the
// given message m and the UserSecretData
func Unblind(sBlind, m *big.Int, u *UserSecretData) *Signature {
// s = b^-1 s' + c
binv := new(big.Int).ModInverse(u.b, N)
binv := new(big.Int).ModInverse(u.B, N)
bs := new(big.Int).Mul(binv, sBlind)
s := new(big.Int).Add(bs, u.c)
s := new(big.Int).Add(bs, u.C)
s = new(big.Int).Mod(s, N)
return &Signature{
@ -164,6 +192,7 @@ func Unblind(sBlind, m *big.Int, u *UserSecretData) *Signature {
}
}
// Verify checks the signature of the message m for the given PublicKey
func Verify(m *big.Int, signature *Signature, q *PublicKey) bool {
// TODO add pending checks
sG := G.Mul(signature.S) // sG

Loading…
Cancel
Save