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|
//go:build ignore
package main
import (
"bytes"
"fmt"
"go/format"
"math/big"
"os"
"path"
"strings"
"text/template"
)
type Fp struct {
Name string
Bits uint
NumRootsUnity uint
NumInverseInt uint
Modulus string
Generator string
}
func (f Fp) NumUint64() int { return int(f.Bits) / 64 }
func (f Fp) NumUint8() int { return int(f.Bits+7) / 8 }
func (f Fp) NeedsMasking() bool {
p := f.Prime()
return p.BitLen() < 8*f.NumUint8()
}
func (f Fp) OrderConst() (s string) {
d := baseTwo64(f.Prime())
for i := f.NumUint64() - 1; i >= 0; i-- {
s += fmt.Sprintf("orderP%v = uint64(0x%v)\n", i, d[i].Text(16))
}
return
}
func (f Fp) OrderVar() string {
var s []string
for i := f.NumUint64() - 1; i >= 0; i-- {
s = append(s, fmt.Sprintf("orderP%v", i))
}
return strings.Join(s, ",")
}
func (f Fp) Prime() *big.Int {
p, _ := new(big.Int).SetString(f.Modulus, 16)
return p
}
func (f Fp) Half() string {
p := f.Prime()
half := big.NewInt(2)
half.ModInverse(half, p)
f.toMont(half, p)
return printDigits(half)
}
func (f Fp) RSquare() string {
p := f.Prime()
R2 := big.NewInt(1)
R2.Lsh(R2, f.Bits)
R2.Mul(R2, R2).Mod(R2, p)
return printDigits(R2)
}
func (f Fp) RootsOfUnity() (s string) {
p := f.Prime()
g, _ := new(big.Int).SetString(f.Generator, 16)
for i := range f.NumRootsUnity + 1 {
twoI := big.NewInt(1)
twoI.Lsh(twoI, f.NumRootsUnity-i)
gi := new(big.Int).Exp(g, twoI, p)
f.toMont(gi, p)
s += "{" + printDigits(gi) + "},\n"
}
return
}
func (f Fp) InverseInt() (s string) {
p := f.Prime()
for i := range f.NumInverseInt {
invI := new(big.Int).ModInverse(big.NewInt(int64(i+1)), p)
f.toMont(invI, p)
s += "{" + printDigits(invI) + "},\n"
}
return
}
func (f Fp) toMont(x, p *big.Int) {
R := big.NewInt(1)
R.Lsh(R, f.Bits)
x.Mul(x, R).Mod(x, p)
}
func baseTwo64(v *big.Int) (d []*big.Int) {
n := new(big.Int).Set(v)
two64 := new(big.Int).Lsh(big.NewInt(1), 64)
for n.Sign() > 0 {
x := new(big.Int).Mod(n, two64)
n.Rsh(n, 64)
d = append(d, x)
}
return
}
func printDigits(n *big.Int) (s string) {
for _, d := range baseTwo64(n) {
s += fmt.Sprintf("0x%016x,", d)
}
return
}
func main() {
const TemplateWarning = "// Code generated from"
fields := []Fp{
{
Name: "Fp64",
Bits: 64,
NumRootsUnity: 32,
NumInverseInt: 8,
// Modulus: 2^32 * 4294967295 + 1
Modulus: "ffffffff00000001",
// Generator: 7^4294967295
Generator: "185629dcda58878c",
},
{
Name: "Fp128",
Bits: 128,
NumRootsUnity: 66,
NumInverseInt: 8,
// Modulus: 2^66 * 4611686018427387897 + 1
Modulus: "ffffffffffffffe40000000000000001",
// Generator: 7^4611686018427387897
Generator: "6d278fbf4f60228b1f9b2759c5109f06",
},
}
for _, file := range []string{"fp_test", "fp", "vector", "poly"} {
tName := "templates/" + file + ".go.tmpl"
tl, err := template.
New(path.Base(tName)).
Funcs(template.FuncMap{"ToLower": strings.ToLower}).
ParseFiles(tName)
if err != nil {
panic(err)
}
for _, f := range fields {
buf := new(bytes.Buffer)
err := tl.Execute(buf, f)
if err != nil {
panic(err)
}
code := buf.Bytes()
code, err = format.Source(code)
if err != nil {
panic("error formating code")
}
res := string(code)
offset := strings.Index(res, TemplateWarning)
if offset == -1 {
panic("Missing template warning")
}
folder := strings.ToLower(f.Name)
fileName := file
if file == "fp_test" {
folder = "."
fileName = strings.ToLower(f.Name) + "_test"
}
path := fmt.Sprintf("%v/%v.go", folder, fileName)
err = os.WriteFile(path, []byte(res[offset:]), 0o600)
if err != nil {
panic(err)
}
}
}
}
|
