diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/bn256/gfp2.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/bn256/gfp2.go | 219 |
1 files changed, 0 insertions, 219 deletions
diff --git a/vendor/golang.org/x/crypto/bn256/gfp2.go b/vendor/golang.org/x/crypto/bn256/gfp2.go deleted file mode 100644 index 97f3f1f3f..000000000 --- a/vendor/golang.org/x/crypto/bn256/gfp2.go +++ /dev/null @@ -1,219 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package bn256 - -// For details of the algorithms used, see "Multiplication and Squaring on -// Pairing-Friendly Fields, Devegili et al. -// http://eprint.iacr.org/2006/471.pdf. - -import ( - "math/big" -) - -// gfP2 implements a field of size p² as a quadratic extension of the base -// field where i²=-1. -type gfP2 struct { - x, y *big.Int // value is xi+y. -} - -func newGFp2(pool *bnPool) *gfP2 { - return &gfP2{pool.Get(), pool.Get()} -} - -func (e *gfP2) String() string { - x := new(big.Int).Mod(e.x, p) - y := new(big.Int).Mod(e.y, p) - return "(" + x.String() + "," + y.String() + ")" -} - -func (e *gfP2) Put(pool *bnPool) { - pool.Put(e.x) - pool.Put(e.y) -} - -func (e *gfP2) Set(a *gfP2) *gfP2 { - e.x.Set(a.x) - e.y.Set(a.y) - return e -} - -func (e *gfP2) SetZero() *gfP2 { - e.x.SetInt64(0) - e.y.SetInt64(0) - return e -} - -func (e *gfP2) SetOne() *gfP2 { - e.x.SetInt64(0) - e.y.SetInt64(1) - return e -} - -func (e *gfP2) Minimal() { - if e.x.Sign() < 0 || e.x.Cmp(p) >= 0 { - e.x.Mod(e.x, p) - } - if e.y.Sign() < 0 || e.y.Cmp(p) >= 0 { - e.y.Mod(e.y, p) - } -} - -func (e *gfP2) IsZero() bool { - return e.x.Sign() == 0 && e.y.Sign() == 0 -} - -func (e *gfP2) IsOne() bool { - if e.x.Sign() != 0 { - return false - } - words := e.y.Bits() - return len(words) == 1 && words[0] == 1 -} - -func (e *gfP2) Conjugate(a *gfP2) *gfP2 { - e.y.Set(a.y) - e.x.Neg(a.x) - return e -} - -func (e *gfP2) Negative(a *gfP2) *gfP2 { - e.x.Neg(a.x) - e.y.Neg(a.y) - return e -} - -func (e *gfP2) Add(a, b *gfP2) *gfP2 { - e.x.Add(a.x, b.x) - e.y.Add(a.y, b.y) - return e -} - -func (e *gfP2) Sub(a, b *gfP2) *gfP2 { - e.x.Sub(a.x, b.x) - e.y.Sub(a.y, b.y) - return e -} - -func (e *gfP2) Double(a *gfP2) *gfP2 { - e.x.Lsh(a.x, 1) - e.y.Lsh(a.y, 1) - return e -} - -func (c *gfP2) Exp(a *gfP2, power *big.Int, pool *bnPool) *gfP2 { - sum := newGFp2(pool) - sum.SetOne() - t := newGFp2(pool) - - for i := power.BitLen() - 1; i >= 0; i-- { - t.Square(sum, pool) - if power.Bit(i) != 0 { - sum.Mul(t, a, pool) - } else { - sum.Set(t) - } - } - - c.Set(sum) - - sum.Put(pool) - t.Put(pool) - - return c -} - -// See "Multiplication and Squaring in Pairing-Friendly Fields", -// http://eprint.iacr.org/2006/471.pdf -func (e *gfP2) Mul(a, b *gfP2, pool *bnPool) *gfP2 { - tx := pool.Get().Mul(a.x, b.y) - t := pool.Get().Mul(b.x, a.y) - tx.Add(tx, t) - tx.Mod(tx, p) - - ty := pool.Get().Mul(a.y, b.y) - t.Mul(a.x, b.x) - ty.Sub(ty, t) - e.y.Mod(ty, p) - e.x.Set(tx) - - pool.Put(tx) - pool.Put(ty) - pool.Put(t) - - return e -} - -func (e *gfP2) MulScalar(a *gfP2, b *big.Int) *gfP2 { - e.x.Mul(a.x, b) - e.y.Mul(a.y, b) - return e -} - -// MulXi sets e=ξa where ξ=i+3 and then returns e. -func (e *gfP2) MulXi(a *gfP2, pool *bnPool) *gfP2 { - // (xi+y)(i+3) = (3x+y)i+(3y-x) - tx := pool.Get().Lsh(a.x, 1) - tx.Add(tx, a.x) - tx.Add(tx, a.y) - - ty := pool.Get().Lsh(a.y, 1) - ty.Add(ty, a.y) - ty.Sub(ty, a.x) - - e.x.Set(tx) - e.y.Set(ty) - - pool.Put(tx) - pool.Put(ty) - - return e -} - -func (e *gfP2) Square(a *gfP2, pool *bnPool) *gfP2 { - // Complex squaring algorithm: - // (xi+b)² = (x+y)(y-x) + 2*i*x*y - t1 := pool.Get().Sub(a.y, a.x) - t2 := pool.Get().Add(a.x, a.y) - ty := pool.Get().Mul(t1, t2) - ty.Mod(ty, p) - - t1.Mul(a.x, a.y) - t1.Lsh(t1, 1) - - e.x.Mod(t1, p) - e.y.Set(ty) - - pool.Put(t1) - pool.Put(t2) - pool.Put(ty) - - return e -} - -func (e *gfP2) Invert(a *gfP2, pool *bnPool) *gfP2 { - // See "Implementing cryptographic pairings", M. Scott, section 3.2. - // ftp://136.206.11.249/pub/crypto/pairings.pdf - t := pool.Get() - t.Mul(a.y, a.y) - t2 := pool.Get() - t2.Mul(a.x, a.x) - t.Add(t, t2) - - inv := pool.Get() - inv.ModInverse(t, p) - - e.x.Neg(a.x) - e.x.Mul(e.x, inv) - e.x.Mod(e.x, p) - - e.y.Mul(a.y, inv) - e.y.Mod(e.y, p) - - pool.Put(t) - pool.Put(t2) - pool.Put(inv) - - return e -} |