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Merge pull request #16 from iden3/feature/mimc7-goff
Feature/mimc7 gofffeature/bbjj-goff v0.0.3
Eduard S
4 years ago
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GitHub
GitHub
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GPG Key ID: 4AEE18F83AFDEB23
5 changed files with 55 additions and 245 deletions
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+0 -152field/field.go
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+0 -39field/field_test.go
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+51 -44mimc7/mimc7.go
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+2 -7mimc7/mimc7_test.go
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+2 -3poseidon/poseidon.go
@ -1,152 +0,0 @@ |
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// code originally taken from https://github.com/arnaucube/go-snark (https://github.com/arnaucube/go-snark/blob/master/fields/fq.go), pasted here to ensure compatibility among future changes
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package field |
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import ( |
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"bytes" |
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"crypto/rand" |
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"math/big" |
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) |
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// Fq is the Z field over modulus Q
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type Fq struct { |
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Q *big.Int // Q
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} |
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// NewFq generates a new Fq
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func NewFq(q *big.Int) Fq { |
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return Fq{ |
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q, |
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} |
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} |
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// Zero returns a Zero value on the Fq
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func (fq Fq) Zero() *big.Int { |
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return big.NewInt(int64(0)) |
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} |
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// One returns a One value on the Fq
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func (fq Fq) One() *big.Int { |
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return big.NewInt(int64(1)) |
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} |
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// Add performs an addition on the Fq
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func (fq Fq) Add(a, b *big.Int) *big.Int { |
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r := new(big.Int).Add(a, b) |
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return new(big.Int).Mod(r, fq.Q) |
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} |
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// Double performs a doubling on the Fq
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func (fq Fq) Double(a *big.Int) *big.Int { |
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r := new(big.Int).Add(a, a) |
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return new(big.Int).Mod(r, fq.Q) |
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} |
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// Sub performs a subtraction on the Fq
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func (fq Fq) Sub(a, b *big.Int) *big.Int { |
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r := new(big.Int).Sub(a, b) |
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return new(big.Int).Mod(r, fq.Q) |
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} |
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// Neg performs a negation on the Fq
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func (fq Fq) Neg(a *big.Int) *big.Int { |
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m := new(big.Int).Neg(a) |
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return new(big.Int).Mod(m, fq.Q) |
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} |
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// Mul performs a multiplication on the Fq
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func (fq Fq) Mul(a, b *big.Int) *big.Int { |
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m := new(big.Int).Mul(a, b) |
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return new(big.Int).Mod(m, fq.Q) |
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} |
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func (fq Fq) MulScalar(base, e *big.Int) *big.Int { |
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return fq.Mul(base, e) |
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} |
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// Inverse returns the inverse on the Fq
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func (fq Fq) Inverse(a *big.Int) *big.Int { |
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return new(big.Int).ModInverse(a, fq.Q) |
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} |
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// Div performs the division over the finite field
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func (fq Fq) Div(a, b *big.Int) *big.Int { |
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d := fq.Mul(a, fq.Inverse(b)) |
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return new(big.Int).Mod(d, fq.Q) |
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} |
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// Square performs a square operation on the Fq
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func (fq Fq) Square(a *big.Int) *big.Int { |
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m := new(big.Int).Mul(a, a) |
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return new(big.Int).Mod(m, fq.Q) |
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} |
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// Exp performs the exponential over Fq
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func (fq Fq) Exp(base *big.Int, e *big.Int) *big.Int { |
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res := fq.One() |
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rem := fq.Copy(e) |
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exp := base |
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for !bytes.Equal(rem.Bytes(), big.NewInt(int64(0)).Bytes()) { |
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if BigIsOdd(rem) { |
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res = fq.Mul(res, exp) |
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} |
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exp = fq.Square(exp) |
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rem = new(big.Int).Rsh(rem, 1) |
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} |
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return res |
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} |
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func (fq Fq) Rand() (*big.Int, error) { |
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maxbits := fq.Q.BitLen() |
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b := make([]byte, (maxbits/8)-1) |
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_, err := rand.Read(b) |
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if err != nil { |
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return nil, err |
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} |
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r := new(big.Int).SetBytes(b) |
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rq := new(big.Int).Mod(r, fq.Q) |
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// r over q, nil
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return rq, nil |
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} |
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func (fq Fq) IsZero(a *big.Int) bool { |
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return bytes.Equal(a.Bytes(), fq.Zero().Bytes()) |
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} |
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func (fq Fq) Copy(a *big.Int) *big.Int { |
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return new(big.Int).SetBytes(a.Bytes()) |
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} |
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func (fq Fq) Affine(a *big.Int) *big.Int { |
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nq := fq.Neg(fq.Q) |
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aux := a |
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if aux.Cmp(big.NewInt(int64(0))) == -1 { // negative value
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if aux.Cmp(nq) != 1 { // aux less or equal nq
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aux = new(big.Int).Mod(aux, fq.Q) |
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} |
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if aux.Cmp(big.NewInt(int64(0))) == -1 { // negative value
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aux = new(big.Int).Add(aux, fq.Q) |
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} |
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} else { |
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if aux.Cmp(fq.Q) != -1 { // aux greater or equal nq
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aux = new(big.Int).Mod(aux, fq.Q) |
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} |
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} |
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return aux |
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} |
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func (fq Fq) Equal(a, b *big.Int) bool { |
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aAff := fq.Affine(a) |
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bAff := fq.Affine(b) |
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return bytes.Equal(aAff.Bytes(), bAff.Bytes()) |
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} |
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func BigIsOdd(n *big.Int) bool { |
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one := big.NewInt(int64(1)) |
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and := new(big.Int).And(n, one) |
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return bytes.Equal(and.Bytes(), big.NewInt(int64(1)).Bytes()) |
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} |
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@ -1,39 +0,0 @@ |
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// code originally taken from https://github.com/arnaucube/go-snark (https://github.com/arnaucube/go-snark/blob/master/fields/fq.go), pasted here to ensure compatibility among future changes
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package field |
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import ( |
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"math/big" |
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"testing" |
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"github.com/stretchr/testify/assert" |
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) |
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func iToBig(a int) *big.Int { |
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return big.NewInt(int64(a)) |
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} |
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func TestFq1(t *testing.T) { |
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fq1 := NewFq(iToBig(7)) |
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res := fq1.Add(iToBig(4), iToBig(4)) |
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assert.Equal(t, iToBig(1), fq1.Affine(res)) |
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res = fq1.Double(iToBig(5)) |
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assert.Equal(t, iToBig(3), fq1.Affine(res)) |
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res = fq1.Sub(iToBig(5), iToBig(7)) |
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assert.Equal(t, iToBig(5), fq1.Affine(res)) |
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res = fq1.Neg(iToBig(5)) |
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assert.Equal(t, iToBig(2), fq1.Affine(res)) |
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res = fq1.Mul(iToBig(5), iToBig(11)) |
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assert.Equal(t, iToBig(6), fq1.Affine(res)) |
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res = fq1.Inverse(iToBig(4)) |
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assert.Equal(t, iToBig(2), res) |
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res = fq1.Square(iToBig(5)) |
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assert.Equal(t, iToBig(4), res) |
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} |
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