1dbf389ceb
This change removes the internal pad function in favor a more opimized paddedAppend function. Unlike pad, which would always alloate a new slice of the desired size and copy the bytes into it, paddedAppend only appends the leading padding when necesary, and uses the builtin append to copy the remaining source bytes. pad was also used in combination with another call to the builtin copy func to copy into a zeroed byte slice. As the slice is now created using make with an initial length of zero, this copy can also be removed. As confirmed by poking the bytes with the unsafe package, gc does not zero array elements between the len and cap when allocating slices with make(). In combination with the paddedAppend func, this results in only a single copy of each byte, with no unnecssary zeroing, when creating the serialized pubkeys. This has not been tested with other Go compilers (namely, gccgo and llgo), but the new behavior is still functionally correct regardless of compiler optimizations. The TestPad function has been removed as the pad func it tested has likewise been removed. ok @davecgh
72 lines
2.2 KiB
Go
72 lines
2.2 KiB
Go
// Copyright (c) 2013-2014 Conformal Systems LLC.
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package btcec
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import (
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"math/big"
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)
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const (
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TstPubkeyUncompressed = pubkeyUncompressed
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TstPubkeyCompressed = pubkeyCompressed
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TstPubkeyHybrid = pubkeyHybrid
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)
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// TstRawInts allows the test package to get the integers from the internal
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// field representation for ensuring correctness. It is only available during
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// the tests.
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func (f *fieldVal) TstRawInts() [10]uint32 {
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return f.n
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}
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// TstSetRawInts allows the test package to directly set the integers used by
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// the internal field representation. It is only available during the tests.
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func (f *fieldVal) TstSetRawInts(raw [10]uint32) *fieldVal {
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for i := 0; i < len(raw); i++ {
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f.n[i] = raw[i]
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}
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return f
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}
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// TstFieldJacobianToBigAffine makes the internal fieldJacobianToBigAffine
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// function available to the test package.
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func (curve *KoblitzCurve) TstFieldJacobianToBigAffine(x, y, z *fieldVal) (*big.Int, *big.Int) {
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return curve.fieldJacobianToBigAffine(x, y, z)
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}
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// TstIsJacobianOnCurve returns boolean if the point (x,y,z) is on the curve.
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func (curve *KoblitzCurve) TstIsJacobianOnCurve(x, y, z *fieldVal) bool {
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// Elliptic curve equation for secp256k1 is: y^2 = x^3 + 7
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// In Jacobian coordinates, Y = y/z^3 and X = x/z^2
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// Thus:
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// (y/z^3)^2 = (x/z^2)^3 + 7
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// y^2/z^6 = x^3/z^6 + 7
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// y^2 = x^3 + 7*z^6
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var y2, z2, x3, result fieldVal
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y2.SquareVal(y).Normalize()
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z2.SquareVal(z)
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x3.SquareVal(x).Mul(x)
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result.SquareVal(&z2).Mul(&z2).MulInt(7).Add(&x3).Normalize()
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return y2.Equals(&result)
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}
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// TstAddJacobian makes the internal addJacobian function available to the test
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// package.
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func (curve *KoblitzCurve) TstAddJacobian(x1, y1, z1, x2, y2, z2, x3, y3, z3 *fieldVal) {
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curve.addJacobian(x1, y1, z1, x2, y2, z2, x3, y3, z3)
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}
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// TstDoubleJacobian makes the internal doubleJacobian function available to the test
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// package.
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func (curve *KoblitzCurve) TstDoubleJacobian(x1, y1, z1, x3, y3, z3 *fieldVal) {
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curve.doubleJacobian(x1, y1, z1, x3, y3, z3)
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}
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// NewFieldVal returns a new field value set to 0. This is only available to
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// the test package.
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func NewFieldVal() *fieldVal {
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return new(fieldVal)
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}
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