Files
next.orly.dev/pkg/crypto/ec/secp256k1/field_test.go

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65 KiB
Go

// Copyright (c) 2013-2016 The btcsuite developers
// Copyright (c) 2015-2022 The Decred developers
// Copyright (c) 2013-2022 Dave Collins
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package secp256k1
import (
"fmt"
"math/big"
"math/rand"
"reflect"
"testing"
"time"
"lol.mleku.dev/chk"
"next.orly.dev/pkg/encoders/hex"
"next.orly.dev/pkg/utils"
)
// SetHex decodes the passed big-endian hex string into the internal field value
// representation. Only the first 32-bytes are used.
//
// This is NOT constant time.
//
// The field value is returned to support chaining. This enables syntax like:
// f := new(FieldVal).SetHex("0abc").Add(1) so that f = 0x0abc + 1
func (f *FieldVal) SetHex(hexString string) *FieldVal {
if len(hexString)%2 != 0 {
hexString = "0" + hexString
}
bytes, _ := hex.Dec(hexString)
f.SetByteSlice(bytes)
return f
}
// randFieldVal returns a field value created from a random value generated by
// the passed rng.
func randFieldVal(t *testing.T, rng *rand.Rand) *FieldVal {
t.Helper()
var buf [32]byte
if _, err := rng.Read(buf[:]); chk.T(err) {
t.Fatalf("failed to read random: %v", err)
}
// Create and return a field value.
var fv FieldVal
fv.SetBytes(&buf)
return &fv
}
// randIntAndFieldVal returns a big integer and a field value both created from
// the same random value generated by the passed rng.
func randIntAndFieldVal(t *testing.T, rng *rand.Rand) (*big.Int, *FieldVal) {
t.Helper()
var buf [32]byte
if _, err := rng.Read(buf[:]); chk.T(err) {
t.Fatalf("failed to read random: %v", err)
}
// Create and return both a big integer and a field value.
bigIntVal := new(big.Int).SetBytes(buf[:])
bigIntVal.Mod(bigIntVal, curveParams.N)
var fv FieldVal
fv.SetBytes(&buf)
return bigIntVal, &fv
}
// TestFieldSetInt ensures that setting a field value to various native
// integers works as expected.
func TestFieldSetInt(t *testing.T) {
tests := []struct {
name string // test description
in uint16 // test value
expected [10]uint32 // expected raw ints
}{
{
name: "one",
in: 1,
expected: [10]uint32{1, 0, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "five",
in: 5,
expected: [10]uint32{5, 0, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^16 - 1",
in: 65535,
expected: [10]uint32{65535, 0, 0, 0, 0, 0, 0, 0, 0, 0},
},
}
for _, test := range tests {
f := new(FieldVal).SetInt(test.in)
if !reflect.DeepEqual(f.n, test.expected) {
t.Errorf(
"%s: wrong result\ngot: %v\nwant: %v", test.name, f.n,
test.expected,
)
continue
}
}
}
// TestFieldSetBytes ensures that setting a field value to a 256-bit big-endian
// unsigned integer via both the slice and array methods works as expected for
// edge cases. Random cases are tested via the various other tests.
func TestFieldSetBytes(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded test value
expected [10]uint32 // expected raw ints
overflow bool // expected overflow result
}{
{
name: "zero",
in: "00",
expected: [10]uint32{0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
overflow: false,
}, {
name: "field prime",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x003fffff,
},
overflow: true,
}, {
name: "field prime - 1",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
expected: [10]uint32{
0x03fffc2e, 0x03ffffbf, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x003fffff,
},
overflow: false,
}, {
name: "field prime + 1 (overflow in word zero)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
expected: [10]uint32{
0x03fffc30, 0x03ffffbf, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x003fffff,
},
overflow: true,
}, {
name: "field prime first 32 bits",
in: "fffffc2f",
expected: [10]uint32{
0x03fffc2f, 0x00000003f, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
},
overflow: false,
}, {
name: "field prime word zero",
in: "03fffc2f",
expected: [10]uint32{
0x03fffc2f, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
},
overflow: false,
}, {
name: "field prime first 64 bits",
in: "fffffffefffffc2f",
expected: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x00000fff, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
},
overflow: false,
}, {
name: "field prime word zero and one",
in: "0ffffefffffc2f",
expected: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
},
overflow: false,
}, {
name: "field prime first 96 bits",
in: "fffffffffffffffefffffc2f",
expected: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x0003ffff, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
},
overflow: false,
}, {
name: "field prime word zero, one, and two",
in: "3ffffffffffefffffc2f",
expected: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
},
overflow: false,
}, {
name: "overflow in word one (prime + 1<<26)",
in: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff03fffc2f",
expected: [10]uint32{
0x03fffc2f, 0x03ffffc0, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x003fffff,
},
overflow: true,
}, {
name: "(field prime - 1) * 2 NOT mod P, truncated >32 bytes",
in: "01fffffffffffffffffffffffffffffffffffffffffffffffffffffffdfffff85c",
expected: [10]uint32{
0x01fffff8, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x00007fff,
},
overflow: false,
}, {
name: "2^256 - 1",
in: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
expected: [10]uint32{
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff, 0x003fffff,
},
overflow: true,
}, {
name: "alternating bits",
in: "a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5",
expected: [10]uint32{
0x01a5a5a5, 0x01696969, 0x025a5a5a, 0x02969696, 0x01a5a5a5,
0x01696969, 0x025a5a5a, 0x02969696, 0x01a5a5a5, 0x00296969,
},
overflow: false,
}, {
name: "alternating bits 2",
in: "5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a",
expected: [10]uint32{
0x025a5a5a, 0x02969696, 0x01a5a5a5, 0x01696969, 0x025a5a5a,
0x02969696, 0x01a5a5a5, 0x01696969, 0x025a5a5a, 0x00169696,
},
overflow: false,
},
}
for _, test := range tests {
inBytes := hexToBytes(test.in)
// Ensure setting the bytes via the slice method works as expected.
var f FieldVal
overflow := f.SetByteSlice(inBytes)
if !reflect.DeepEqual(f.n, test.expected) {
t.Errorf(
"%s: unexpected result\ngot: %x\nwant: %x", test.name, f.n,
test.expected,
)
continue
}
// Ensure the setting the bytes via the slice method produces the
// expected overflow result.
if overflow != test.overflow {
t.Errorf(
"%s: unexpected overflow -- got: %v, want: %v", test.name,
overflow, test.overflow,
)
continue
}
// Ensure setting the bytes via the array method works as expected.
var f2 FieldVal
var b32 [32]byte
truncatedInBytes := inBytes
if len(truncatedInBytes) > 32 {
truncatedInBytes = truncatedInBytes[:32]
}
copy(b32[32-len(truncatedInBytes):], truncatedInBytes)
overflow = f2.SetBytes(&b32) != 0
if !reflect.DeepEqual(f2.n, test.expected) {
t.Errorf(
"%s: unexpected result\ngot: %x\nwant: %x", test.name,
f2.n, test.expected,
)
continue
}
// Ensure the setting the bytes via the array method produces the
// expected overflow result.
if overflow != test.overflow {
t.Errorf(
"%s: unexpected overflow -- got: %v, want: %v", test.name,
overflow, test.overflow,
)
continue
}
}
}
// TestFieldBytes ensures that retrieving the bytes for a 256-bit big-endian
// unsigned integer via the various methods works as expected for edge cases.
// Random cases are tested via the various other tests.
func TestFieldBytes(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded test value
expected string // expected hex encoded bytes
}{
{
name: "zero",
in: "0",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
}, {
name: "field prime (aka 0)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
}, {
name: "field prime - 1",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
}, {
name: "field prime + 1 (aka 1, overflow in word zero)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
expected: "0000000000000000000000000000000000000000000000000000000000000001",
}, {
name: "field prime first 32 bits",
in: "fffffc2f",
expected: "00000000000000000000000000000000000000000000000000000000fffffc2f",
}, {
name: "field prime word zero",
in: "03fffc2f",
expected: "0000000000000000000000000000000000000000000000000000000003fffc2f",
}, {
name: "field prime first 64 bits",
in: "fffffffefffffc2f",
expected: "000000000000000000000000000000000000000000000000fffffffefffffc2f",
}, {
name: "field prime word zero and one",
in: "0ffffefffffc2f",
expected: "000000000000000000000000000000000000000000000000000ffffefffffc2f",
}, {
name: "field prime first 96 bits",
in: "fffffffffffffffefffffc2f",
expected: "0000000000000000000000000000000000000000fffffffffffffffefffffc2f",
}, {
name: "field prime word zero, one, and two",
in: "3ffffffffffefffffc2f",
expected: "000000000000000000000000000000000000000000003ffffffffffefffffc2f",
}, {
name: "overflow in word one (prime + 1<<26)",
in: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff03fffc2f",
expected: "0000000000000000000000000000000000000000000000000000000004000000",
}, {
name: "2^256 - 1",
in: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
expected: "00000000000000000000000000000000000000000000000000000001000003d0",
}, {
name: "alternating bits",
in: "a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5",
expected: "a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5",
}, {
name: "alternating bits 2",
in: "5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a",
expected: "5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in).Normalize()
expected := hexToBytes(test.expected)
// Ensure getting the bytes works as expected.
gotBytes := f.Bytes()
if !utils.FastEqual(gotBytes[:], expected) {
t.Errorf(
"%s: unexpected result\ngot: %x\nwant: %x", test.name,
*gotBytes, expected,
)
continue
}
// Ensure getting the bytes directly into an array works as expected.
var b32 [32]byte
f.PutBytes(&b32)
if !utils.FastEqual(b32[:], expected) {
t.Errorf(
"%s: unexpected result\ngot: %x\nwant: %x", test.name,
b32, expected,
)
continue
}
// Ensure getting the bytes directly into a slice works as expected.
var buffer [64]byte
f.PutBytesUnchecked(buffer[:])
if !utils.FastEqual(buffer[:32], expected) {
t.Errorf(
"%s: unexpected result\ngot: %x\nwant: %x", test.name,
buffer[:32], expected,
)
continue
}
}
}
// TestFieldZero ensures that zeroing a field value works as expected.
func TestFieldZero(t *testing.T) {
var f FieldVal
f.SetHex("a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5a5")
f.Zero()
for idx, rawInt := range f.n {
if rawInt != 0 {
t.Errorf(
"internal integer at index #%d is not zero - got %d", idx,
rawInt,
)
}
}
}
// TestFieldIsZero ensures that checking if a field is zero via IsZero and
// IsZeroBit works as expected.
func TestFieldIsZero(t *testing.T) {
f := new(FieldVal)
if !f.IsZero() {
t.Errorf("new field value is not zero - got %v (rawints %x)", f, f.n)
}
if f.IsZeroBit() != 1 {
t.Errorf("new field value is not zero - got %v (rawints %x)", f, f.n)
}
f.SetInt(1)
if f.IsZero() {
t.Errorf("claims zero for nonzero field - got %v (rawints %x)", f, f.n)
}
if f.IsZeroBit() == 1 {
t.Errorf("claims zero for nonzero field - got %v (rawints %x)", f, f.n)
}
f.Zero()
if !f.IsZero() {
t.Errorf("claims nonzero for zero field - got %v (rawints %x)", f, f.n)
}
if f.IsZeroBit() != 1 {
t.Errorf("claims nonzero for zero field - got %v (rawints %x)", f, f.n)
}
f.SetInt(1)
f.Zero()
if !f.IsZero() {
t.Errorf("claims zero for nonzero field - got %v (rawints %x)", f, f.n)
}
if f.IsZeroBit() != 1 {
t.Errorf("claims zero for nonzero field - got %v (rawints %x)", f, f.n)
}
}
// TestFieldIsOne ensures that checking if a field is one via IsOne and IsOneBit
// works as expected.
func TestFieldIsOne(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded test value
normalize bool // whether or not to normalize the test value
expected bool // expected result
}{
{
name: "zero",
in: "0",
normalize: true,
expected: false,
}, {
name: "one",
in: "1",
normalize: true,
expected: true,
}, {
name: "secp256k1 prime NOT normalized (would be 0)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
normalize: false,
expected: false,
}, {
name: "secp256k1 prime normalized (aka 0)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
normalize: true,
expected: false,
}, {
name: "secp256k1 prime + 1 normalized (aka 1)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
normalize: true,
expected: true,
}, {
name: "secp256k1 prime + 1 NOT normalized (would be 1)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
normalize: false,
expected: false,
}, {
name: "2^26 (one bit in second internal field word",
in: "4000000",
normalize: false,
expected: false,
}, {
name: "2^52 (one bit in third internal field word",
in: "10000000000000",
normalize: false,
expected: false,
}, {
name: "2^78 (one bit in fourth internal field word",
in: "40000000000000000000",
normalize: false,
expected: false,
}, {
name: "2^104 (one bit in fifth internal field word",
in: "100000000000000000000000000",
normalize: false,
expected: false,
}, {
name: "2^130 (one bit in sixth internal field word",
in: "400000000000000000000000000000000",
normalize: false,
expected: false,
}, {
name: "2^156 (one bit in seventh internal field word",
in: "1000000000000000000000000000000000000000",
normalize: false,
expected: false,
}, {
name: "2^182 (one bit in eighth internal field word",
in: "4000000000000000000000000000000000000000000000",
normalize: false,
expected: false,
}, {
name: "2^208 (one bit in ninth internal field word",
in: "10000000000000000000000000000000000000000000000000000",
normalize: false,
expected: false,
}, {
name: "2^234 (one bit in tenth internal field word",
in: "40000000000000000000000000000000000000000000000000000000000",
normalize: false,
expected: false,
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in)
if test.normalize {
f.Normalize()
}
result := f.IsOne()
if result != test.expected {
t.Errorf(
"%s: wrong result -- got: %v, want: %v", test.name, result,
test.expected,
)
continue
}
result2 := f.IsOneBit() == 1
if result2 != test.expected {
t.Errorf(
"%s: wrong result -- got: %v, want: %v", test.name,
result2, test.expected,
)
continue
}
}
}
// TestFieldStringer ensures the stringer returns the appropriate hex string.
func TestFieldStringer(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded test value
expected string // expected result
}{
{
name: "zero",
in: "0",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
}, {
name: "one",
in: "1",
expected: "0000000000000000000000000000000000000000000000000000000000000001",
}, {
name: "ten",
in: "a",
expected: "000000000000000000000000000000000000000000000000000000000000000a",
}, {
name: "eleven",
in: "b",
expected: "000000000000000000000000000000000000000000000000000000000000000b",
}, {
name: "twelve",
in: "c",
expected: "000000000000000000000000000000000000000000000000000000000000000c",
}, {
name: "thirteen",
in: "d",
expected: "000000000000000000000000000000000000000000000000000000000000000d",
}, {
name: "fourteen",
in: "e",
expected: "000000000000000000000000000000000000000000000000000000000000000e",
}, {
name: "fifteen",
in: "f",
expected: "000000000000000000000000000000000000000000000000000000000000000f",
}, {
name: "240",
in: "f0",
expected: "00000000000000000000000000000000000000000000000000000000000000f0",
}, {
name: "2^26 - 1",
in: "3ffffff",
expected: "0000000000000000000000000000000000000000000000000000000003ffffff",
}, {
name: "2^32 - 1",
in: "ffffffff",
expected: "00000000000000000000000000000000000000000000000000000000ffffffff",
}, {
name: "2^64 - 1",
in: "ffffffffffffffff",
expected: "000000000000000000000000000000000000000000000000ffffffffffffffff",
}, {
name: "2^96 - 1",
in: "ffffffffffffffffffffffff",
expected: "0000000000000000000000000000000000000000ffffffffffffffffffffffff",
}, {
name: "2^128 - 1",
in: "ffffffffffffffffffffffffffffffff",
expected: "00000000000000000000000000000000ffffffffffffffffffffffffffffffff",
}, {
name: "2^160 - 1",
in: "ffffffffffffffffffffffffffffffffffffffff",
expected: "000000000000000000000000ffffffffffffffffffffffffffffffffffffffff",
}, {
name: "2^192 - 1",
in: "ffffffffffffffffffffffffffffffffffffffffffffffff",
expected: "0000000000000000ffffffffffffffffffffffffffffffffffffffffffffffff",
}, {
name: "2^224 - 1",
in: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
expected: "00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
}, {
name: "2^256-4294968273 (the secp256k1 prime, so should result in 0)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
}, {
name: "2^256-4294968274 (the secp256k1 prime+1, so should result in 1)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
expected: "0000000000000000000000000000000000000000000000000000000000000001",
}, {
name: "invalid hex g",
in: "g",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
}, {
name: "invalid hex 1h",
in: "1h",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
}, {
name: "invalid hex i1",
in: "i1",
expected: "0000000000000000000000000000000000000000000000000000000000000000",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in)
result := f.String()
if result != test.expected {
t.Errorf(
"%s: wrong result\ngot: %v\nwant: %v", test.name, result,
test.expected,
)
continue
}
}
}
// TestFieldNormalize ensures that normalizing the internal field words works as
// expected.
func TestFieldNormalize(t *testing.T) {
tests := []struct {
name string // test description
raw [10]uint32 // Intentionally denormalized value
normalized [10]uint32 // Normalized form of the raw value
}{
{
name: "5",
raw: [10]uint32{0x00000005, 0, 0, 0, 0, 0, 0, 0, 0, 0},
normalized: [10]uint32{0x00000005, 0, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^26",
raw: [10]uint32{0x04000000, 0x0, 0, 0, 0, 0, 0, 0, 0, 0},
normalized: [10]uint32{0x00000000, 0x1, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^26 + 1",
raw: [10]uint32{0x04000001, 0x0, 0, 0, 0, 0, 0, 0, 0, 0},
normalized: [10]uint32{0x00000001, 0x1, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^32 - 1",
raw: [10]uint32{0xffffffff, 0x00, 0, 0, 0, 0, 0, 0, 0, 0},
normalized: [10]uint32{0x03ffffff, 0x3f, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^32",
raw: [10]uint32{0x04000000, 0x3f, 0, 0, 0, 0, 0, 0, 0, 0},
normalized: [10]uint32{0x00000000, 0x40, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^32 + 1",
raw: [10]uint32{0x04000001, 0x3f, 0, 0, 0, 0, 0, 0, 0, 0},
normalized: [10]uint32{0x00000001, 0x40, 0, 0, 0, 0, 0, 0, 0, 0},
}, {
name: "2^64 - 1",
raw: [10]uint32{
0xffffffff, 0xffffffc0, 0xfc0, 0, 0, 0, 0, 0, 0,
0,
},
normalized: [10]uint32{
0x03ffffff, 0x03ffffff, 0xfff, 0, 0, 0, 0, 0, 0,
0,
},
}, {
name: "2^64",
raw: [10]uint32{
0x04000000, 0x03ffffff, 0x0fff, 0, 0, 0, 0, 0, 0,
0,
},
normalized: [10]uint32{
0x00000000, 0x00000000, 0x1000, 0, 0, 0, 0, 0, 0,
0,
},
}, {
name: "2^64 + 1",
raw: [10]uint32{
0x04000001, 0x03ffffff, 0x0fff, 0, 0, 0, 0, 0, 0,
0,
},
normalized: [10]uint32{
0x00000001, 0x00000000, 0x1000, 0, 0, 0, 0, 0, 0,
0,
},
}, {
name: "2^96 - 1",
raw: [10]uint32{
0xffffffff, 0xffffffc0, 0xffffffc0, 0x3ffc0, 0,
0, 0, 0, 0, 0,
},
normalized: [10]uint32{
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x3ffff, 0,
0, 0, 0, 0, 0,
},
}, {
name: "2^96",
raw: [10]uint32{
0x04000000, 0x03ffffff, 0x03ffffff, 0x3ffff, 0,
0, 0, 0, 0, 0,
},
normalized: [10]uint32{
0x00000000, 0x00000000, 0x00000000, 0x40000, 0,
0, 0, 0, 0, 0,
},
}, {
name: "2^128 - 1",
raw: [10]uint32{
0xffffffff, 0xffffffc0, 0xffffffc0, 0xffffffc0,
0xffffc0, 0, 0, 0, 0, 0,
},
normalized: [10]uint32{
0x03ffffff, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0xffffff, 0, 0, 0, 0, 0,
},
}, {
name: "2^128",
raw: [10]uint32{
0x04000000, 0x03ffffff, 0x03ffffff, 0x03ffffff,
0x0ffffff, 0, 0, 0, 0, 0,
},
normalized: [10]uint32{
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x1000000, 0, 0, 0, 0, 0,
},
}, {
name: "2^256 - 4294968273 (secp256k1 prime)",
raw: [10]uint32{
0xfffffc2f, 0xffffff80, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0x3fffc0,
},
normalized: [10]uint32{
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x000000,
},
}, {
// Value larger than P where both first and second words are larger than
// P's first and second words
name: "Value > P with 1st and 2nd words > P's 1st and 2nd words",
raw: [10]uint32{
0xfffffc30, 0xffffff86, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0x3fffc0,
},
normalized: [10]uint32{
0x00000001, 0x00000006, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x000000,
},
}, {
// Value larger than P where only the second word is larger than P's
// second word.
name: "Value > P with 2nd word > P's 2nd word",
raw: [10]uint32{
0xfffffc2a, 0xffffff87, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0x3fffc0,
},
normalized: [10]uint32{
0x03fffffb, 0x00000006, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x000000,
},
}, {
name: "2^256 - 1",
raw: [10]uint32{
0xffffffff, 0xffffffc0, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0xffffffc0,
0xffffffc0, 0xffffffc0, 0x3fffc0,
},
normalized: [10]uint32{
0x000003d0, 0x00000040, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x000000,
},
}, {
// Prime with field representation such that the initial reduction does
// not result in a carry to bit 256.
//
// 2^256 - 4294968273 (secp256k1 prime)
name: "2^256 - 4294968273 (secp256k1 prime)",
raw: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x00000000, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
},
}, {
// Value larger than P that reduces to a value which is still larger
// than P when it has a magnitude of 1 due to its first word and does
// not result in a carry to bit 256.
//
// 2^256 - 4294968272 (secp256k1 prime + 1)
name: "2^256 - 4294968272 (secp256k1 prime + 1)",
raw: [10]uint32{
0x03fffc30, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x00000001, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
},
}, {
// Value larger than P that reduces to a value which is still larger
// than P when it has a magnitude of 1 due to its second word and does
// not result in a carry to bit 256.
//
// 2^256 - 4227859409 (secp256k1 prime + 0x4000000)
name: "2^256 - 4227859409 (secp256k1 prime + 0x4000000)",
raw: [10]uint32{
0x03fffc2f, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x00000000, 0x00000001, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
},
}, {
// Value larger than P that reduces to a value which is still larger
// than P when it has a magnitude of 1 due to a carry to bit 256, but
// would not be without the carry. These values come from the fact that
// P is 2^256 - 4294968273 and 977 is the low order word in the internal
// field representation.
//
// 2^256 * 5 - ((4294968273 - (977+1)) * 4)
name: "2^256 * 5 - ((4294968273 - (977+1)) * 4)",
raw: [10]uint32{
0x03ffffff, 0x03fffeff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x0013fffff,
},
normalized: [10]uint32{
0x00001314, 0x00000040, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x000000000,
},
}, {
// Value larger than P that reduces to a value which is still larger
// than P when it has a magnitude of 1 due to both a carry to bit 256
// and the first word.
name: "Value > P with redux > P at mag 1 due to 1st word and carry to bit 256",
raw: [10]uint32{
0x03fffc30, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x07ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x00000001, 0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000001,
},
}, {
// Value larger than P that reduces to a value which is still larger
// than P when it has a magnitude of 1 due to both a carry to bit 256
// and the second word.
name: "Value > P with redux > P at mag 1 due to 2nd word and carry to bit 256",
raw: [10]uint32{
0x03fffc2f, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x3ffffff, 0x07ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x00000000, 0x00000001, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x0000000, 0x00000000, 0x00000001,
},
}, {
// Value larger than P that reduces to a value which is still larger
// than P when it has a magnitude of 1 due to a carry to bit 256 and the
// first and second words.
name: "Value > P with redux > P at mag 1 due to 1st and 2nd words and carry to bit 256",
raw: [10]uint32{
0x03fffc30, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x07ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x00000001, 0x00000001, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000000,
0x00000000, 0x00000000, 0x00000001,
},
}, {
// ---------------------------------------------------------------------
// There are 3 main conditions that must be true if the final reduction
// is needed after the initial reduction to magnitude 1 when there was
// NOT a carry to bit 256 (in other words when the original value was <
// 2^256):
// 1) The final word of the reduced value is equal to the one of P
// 2) The 3rd through 9th words are equal to those of P
// 3) Either:
// - The 2nd word is greater than the one of P; or
// - The 2nd word is equal to that of P AND the 1st word is greater
//
// Therefore the eight possible combinations of those 3 main conditions
// can be thought of in binary where each bit starting from the left
// corresponds to the aforementioned conditions as such:
// 000, 001, 010, 011, 100, 101, 110, 111
//
// For example, combination 6 is when both conditons 1 and 2 are true,
// but condition 3 is NOT true.
//
// The following tests hit each of these combinations and refer to each
// by its decimal equivalent for ease of reference.
//
// NOTE: The final combination (7) is already tested above since it only
// happens when the original value is already the normalized
// representation of P.
// ---------------------------------------------------------------------
name: "Value < 2^256 final reduction combination 0",
raw: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003ffffe,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003ffffe,
},
}, {
name: "Value < 2^256 final reduction combination 1 via 2nd word",
raw: [10]uint32{
0x03fff85e, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003ffffe,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003ffffe,
},
}, {
name: "Value < 2^256 final reduction combination 1 via 1st word",
raw: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003ffffe,
},
normalized: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003ffffe,
},
}, {
name: "Value < 2^256 final reduction combination 2",
raw: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003ffffe,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003ffffe,
},
}, {
name: "Value < 2^256 final reduction combination 3 via 2nd word",
raw: [10]uint32{
0x03fff85e, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003ffffe,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003ffffe,
},
}, {
name: "Value < 2^256 final reduction combination 3 via 1st word",
raw: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003ffffe,
},
normalized: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003ffffe,
},
}, {
name: "Value < 2^256 final reduction combination 4",
raw: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003fffff,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003fffff,
},
}, {
name: "Value < 2^256 final reduction combination 5 via 2nd word",
raw: [10]uint32{
0x03fff85e, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003fffff,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffc0, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003fffff,
},
}, {
name: "Value < 2^256 final reduction combination 5 via 1st word",
raw: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003fffff,
},
normalized: [10]uint32{
0x03fffc2f, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03fffffe, 0x003fffff,
},
}, {
name: "Value < 2^256 final reduction combination 6",
raw: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003fffff,
},
normalized: [10]uint32{
0x03fff85e, 0x03ffffbf, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x03ffffff,
0x03ffffff, 0x03ffffff, 0x003fffff,
},
},
}
for _, test := range tests {
f := new(FieldVal)
f.n = test.raw
f.Normalize()
if !reflect.DeepEqual(f.n, test.normalized) {
t.Errorf(
"%s: wrong normalized result\ngot: %x\nwant: %x",
test.name, f.n, test.normalized,
)
continue
}
}
}
// TestFieldIsOdd ensures that checking if a field value is odd via IsOdd and
// IsOddBit works as expected.
func TestFieldIsOdd(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded value
expected bool // expected oddness
}{
{
name: "zero",
in: "0",
expected: false,
}, {
name: "one",
in: "1",
expected: true,
}, {
name: "two",
in: "2",
expected: false,
}, {
name: "2^32 - 1",
in: "ffffffff",
expected: true,
}, {
name: "2^64 - 2",
in: "fffffffffffffffe",
expected: false,
}, {
name: "secp256k1 prime (not normalized so should be incorrect result)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: true,
}, {
name: "secp256k1 prime + 1 (not normalized so should be incorrect result)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
expected: false,
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in)
result := f.IsOdd()
if result != test.expected {
t.Errorf(
"%s: wrong result -- got: %v, want: %v", test.name,
result, test.expected,
)
continue
}
result2 := f.IsOddBit() == 1
if result2 != test.expected {
t.Errorf(
"%s: wrong result -- got: %v, want: %v", test.name,
result2, test.expected,
)
continue
}
}
}
// TestFieldEquals ensures that checking two field values for equality via
// Equals works as expected.
func TestFieldEquals(t *testing.T) {
tests := []struct {
name string // test description
in1 string // hex encoded value
in2 string // hex encoded value
expected bool // expected equality
}{
{
name: "0 == 0?",
in1: "0",
in2: "0",
expected: true,
}, {
name: "0 == 1?",
in1: "0",
in2: "1",
expected: false,
}, {
name: "1 == 0?",
in1: "1",
in2: "0",
expected: false,
}, {
name: "2^32 - 1 == 2^32 - 1?",
in1: "ffffffff",
in2: "ffffffff",
expected: true,
}, {
name: "2^64 - 1 == 2^64 - 2?",
in1: "ffffffffffffffff",
in2: "fffffffffffffffe",
expected: false,
}, {
name: "0 == prime (mod prime)?",
in1: "0",
in2: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: true,
}, {
name: "1 == prime + 1 (mod prime)?",
in1: "1",
in2: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc30",
expected: true,
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in1).Normalize()
f2 := new(FieldVal).SetHex(test.in2).Normalize()
result := f.Equals(f2)
if result != test.expected {
t.Errorf(
"%s: wrong result -- got: %v, want: %v", test.name, result,
test.expected,
)
continue
}
}
}
// TestFieldNegate ensures that negating field values via Negate works as
// expected.
func TestFieldNegate(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded test value
expected string // hex encoded expected result
}{
{
name: "zero",
in: "0",
expected: "0",
}, {
name: "secp256k1 prime (direct val in with 0 out)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: "0",
}, {
name: "secp256k1 prime (0 in with direct val out)",
in: "0",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
}, {
name: "1 -> secp256k1 prime - 1",
in: "1",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
}, {
name: "secp256k1 prime - 1 -> 1",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
expected: "1",
}, {
name: "2 -> secp256k1 prime - 2",
in: "2",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
}, {
name: "secp256k1 prime - 2 -> 2",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
expected: "2",
}, {
name: "random sampling #1",
in: "b3d9aac9c5e43910b4385b53c7e78c21d4cd5f8e683c633aed04c233efc2e120",
expected: "4c2655363a1bc6ef4bc7a4ac381873de2b32a07197c39cc512fb3dcb103d1b0f",
}, {
name: "random sampling #2",
in: "f8a85984fee5a12a7c8dd08830d83423c937d77c379e4a958e447a25f407733f",
expected: "757a67b011a5ed583722f77cf27cbdc36c82883c861b56a71bb85d90bf888f0",
}, {
name: "random sampling #3",
in: "45ee6142a7fda884211e93352ed6cb2807800e419533be723a9548823ece8312",
expected: "ba119ebd5802577bdee16ccad12934d7f87ff1be6acc418dc56ab77cc131791d",
}, {
name: "random sampling #4",
in: "53c2a668f07e411a2e473e1c3b6dcb495dec1227af27673761d44afe5b43d22b",
expected: "ac3d59970f81bee5d1b8c1e3c49234b6a213edd850d898c89e2bb500a4bc2a04",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
// Ensure negating another value produces the expected result.
result := new(FieldVal).NegateVal(f, 1).Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: unexpected result -- got: %v, want: %v", test.name,
result, expected,
)
continue
}
// Ensure self negating also produces the expected result.
result2 := f.Negate(1).Normalize()
if !result2.Equals(expected) {
t.Errorf(
"%s: unexpected result -- got: %v, want: %v", test.name,
result2, expected,
)
continue
}
}
}
// TestFieldAddInt ensures that adding an integer to field values via AddInt
// works as expected.
func TestFieldAddInt(t *testing.T) {
tests := []struct {
name string // test description
in1 string // hex encoded value
in2 uint16 // unsigned integer to add to the value above
expected string // expected hex encoded value
}{
{
name: "zero + one",
in1: "0",
in2: 1,
expected: "1",
}, {
name: "one + zero",
in1: "1",
in2: 0,
expected: "1",
}, {
name: "one + one",
in1: "1",
in2: 1,
expected: "2",
}, {
name: "secp256k1 prime-1 + 1",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
in2: 1,
expected: "0",
}, {
name: "secp256k1 prime + 1",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
in2: 1,
expected: "1",
}, {
name: "random sampling #1",
in1: "ff95ad9315aff04ab4af0ce673620c7145dc85d03bab5ba4b09ca2c4dec2d6c1",
in2: 0x10f,
expected: "ff95ad9315aff04ab4af0ce673620c7145dc85d03bab5ba4b09ca2c4dec2d7d0",
}, {
name: "random sampling #2",
in1: "44bdae6b772e7987941f1ba314e6a5b7804a4c12c00961b57d20f41deea9cecf",
in2: 0x3196,
expected: "44bdae6b772e7987941f1ba314e6a5b7804a4c12c00961b57d20f41deeaa0065",
}, {
name: "random sampling #3",
in1: "88c3ecae67b591935fb1f6a9499c35315ffad766adca665c50b55f7105122c9c",
in2: 0x966f,
expected: "88c3ecae67b591935fb1f6a9499c35315ffad766adca665c50b55f710512c30b",
}, {
name: "random sampling #4",
in1: "8523e9edf360ca32a95aae4e57fcde5a542b471d08a974d94ea0ee09a015e2a6",
in2: 0xc54,
expected: "8523e9edf360ca32a95aae4e57fcde5a542b471d08a974d94ea0ee09a015eefa",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in1).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
result := f.AddInt(test.in2).Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: wrong result -- got: %v -- want: %v", test.name,
result, expected,
)
continue
}
}
}
// TestFieldAdd ensures that adding two field values together via Add and Add2
// works as expected.
func TestFieldAdd(t *testing.T) {
tests := []struct {
name string // test description
in1 string // first hex encoded value
in2 string // second hex encoded value to add
expected string // expected hex encoded value
}{
{
name: "zero + one",
in1: "0",
in2: "1",
expected: "1",
}, {
name: "one + zero",
in1: "1",
in2: "0",
expected: "1",
}, {
name: "secp256k1 prime-1 + 1",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
in2: "1",
expected: "0",
}, {
name: "secp256k1 prime + 1",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
in2: "1",
expected: "1",
}, {
name: "random sampling #1",
in1: "2b2012f975404e5065b4292fb8bed0a5d315eacf24c74d8b27e73bcc5430edcc",
in2: "2c3cefa4e4753e8aeec6ac4c12d99da4d78accefda3b7885d4c6bab46c86db92",
expected: "575d029e59b58cdb547ad57bcb986e4aaaa0b7beff02c610fcadf680c0b7c95e",
}, {
name: "random sampling #2",
in1: "8131e8722fe59bb189692b96c9f38de92885730f1dd39ab025daffb94c97f79c",
in2: "ff5454b765f0aab5f0977dcc629becc84cabeb9def48e79c6aadb2622c490fa9",
expected: "80863d2995d646677a00a9632c8f7ab175315ead0d1c824c9088b21c78e10b16",
}, {
name: "random sampling #3",
in1: "c7c95e93d0892b2b2cdd77e80eb646ea61be7a30ac7e097e9f843af73fad5c22",
in2: "3afe6f91a74dfc1c7f15c34907ee981656c37236d946767dd53ccad9190e437c",
expected: "2c7ce2577d72747abf33b3116a4df00b881ec6785c47ffc74c105d158bba36f",
}, {
name: "random sampling #4",
in1: "fd1c26f6a23381e5d785ba889494ec059369b888ad8431cd67d8c934b580dbe1",
in2: "a475aa5a31dcca90ef5b53c097d9133d6b7117474b41e7877bb199590fc0489c",
expected: "a191d150d4104c76c6e10e492c6dff42fedacfcff8c61954e38a628ec541284e",
}, {
name: "random sampling #5",
in1: "ad82b8d1cc136e23e9fd77fe2c7db1fe5a2ecbfcbde59ab3529758334f862d28",
in2: "4d6a4e95d6d61f4f46b528bebe152d408fd741157a28f415639347a84f6f574b",
expected: "faed0767a2e98d7330b2a0bcea92df3eea060d12380e8ec8b62a9fdb9ef58473",
}, {
name: "random sampling #6",
in1: "f3f43a2540054a86e1df98547ec1c0e157b193e5350fb4a3c3ea214b228ac5e7",
in2: "25706572592690ea3ddc951a1b48b504a4c83dc253756e1b96d56fdfb3199522",
expected: "19649f97992bdb711fbc2d6e9a0a75e5fc79d1a7888522bf5abf912bd5a45eda",
}, {
name: "random sampling #7",
in1: "6915bb94eef13ff1bb9b2633d997e13b9b1157c713363cc0e891416d6734f5b8",
in2: "11f90d6ac6fe1c4e8900b1c85fb575c251ec31b9bc34b35ada0aea1c21eded22",
expected: "7b0ec8ffb5ef5c40449bd7fc394d56fdecfd8980cf6af01bc29c2b898922e2da",
}, {
name: "random sampling #8",
in1: "48b0c9eae622eed9335b747968544eb3e75cb2dc8128388f948aa30f88cabde4",
in2: "0989882b52f85f9d524a3a3061a0e01f46d597839d2ba637320f4b9510c8d2d5",
expected: "523a5216391b4e7685a5aea9c9f52ed32e324a601e53dec6c699eea4999390b9",
},
}
for _, test := range tests {
// Parse test hex.
f1 := new(FieldVal).SetHex(test.in1).Normalize()
f2 := new(FieldVal).SetHex(test.in2).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
// Ensure adding the two values with the result going to another
// variable produces the expected result.
result := new(FieldVal).Add2(f1, f2).Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: unexpected result\ngot: %v\nwant: %v", test.name,
result, expected,
)
continue
}
// Ensure adding the value to an existing field value produces the
// expected result.
f1.Add(f2).Normalize()
if !f1.Equals(expected) {
t.Errorf(
"%s: unexpected result\ngot: %v\nwant: %v", test.name,
f1, expected,
)
continue
}
}
}
// TestFieldMulInt ensures that multiplying an integer to field values via
// MulInt works as expected.
func TestFieldMulInt(t *testing.T) {
tests := []struct {
name string // test description
in1 string // hex encoded value
in2 uint8 // unsigned integer to multiply with value above
expected string // expected hex encoded value
}{
{
name: "zero * zero",
in1: "0",
in2: 0,
expected: "0",
}, {
name: "one * zero",
in1: "1",
in2: 0,
expected: "0",
}, {
name: "zero * one",
in1: "0",
in2: 1,
expected: "0",
}, {
name: "one * one",
in1: "1",
in2: 1,
expected: "1",
}, {
name: "secp256k1 prime-1 * 2",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
in2: 2,
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
}, {
name: "secp256k1 prime * 3",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
in2: 3,
expected: "0",
}, {
name: "secp256k1 prime-1 * 8",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
in2: 8,
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc27",
}, {
// Random samples for first value. The second value is limited
// to 8 since that is the maximum int used in the elliptic curve
// calculations.
name: "random sampling #1",
in1: "b75674dc9180d306c692163ac5e089f7cef166af99645c0c23568ab6d967288a",
in2: 6,
expected: "4c06bd2b6904f228a76c8560a3433bced9a8681d985a2848d407404d186b0280",
}, {
name: "random sampling #2",
in1: "54873298ac2b5ba8591c125ae54931f5ea72040aee07b208d6135476fb5b9c0e",
in2: 3,
expected: "fd9597ca048212f90b543710afdb95e1bf560c20ca17161a8239fd64f212d42a",
}, {
name: "random sampling #3",
in1: "7c30fbd363a74c17e1198f56b090b59bbb6c8755a74927a6cba7a54843506401",
in2: 5,
expected: "6cf4eb20f2447c77657fccb172d38c0aa91ea4ac446dc641fa463a6b5091fba7",
}, {
name: "random sampling #3",
in1: "fb4529be3e027a3d1587d8a500b72f2d312e3577340ef5175f96d113be4c2ceb",
in2: 8,
expected: "da294df1f013d1e8ac3ec52805b979698971abb9a077a8bafcb688a4f261820f",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in1).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
result := f.MulInt(test.in2).Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: wrong result -- got: %v -- want: %v", test.name,
result, expected,
)
continue
}
}
}
// TestFieldMul ensures that multiplying two field values via Mul and Mul2 works
// as expected.
func TestFieldMul(t *testing.T) {
tests := []struct {
name string // test description
in1 string // first hex encoded value
in2 string // second hex encoded value to multiply with
expected string // expected hex encoded value
}{
{
name: "zero * zero",
in1: "0",
in2: "0",
expected: "0",
}, {
name: "one * zero",
in1: "1",
in2: "0",
expected: "0",
}, {
name: "zero * one",
in1: "0",
in2: "1",
expected: "0",
}, {
name: "one * one",
in1: "1",
in2: "1",
expected: "1",
}, {
name: "slightly over prime",
in1: "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff1ffff",
in2: "1000",
expected: "1ffff3d1",
}, {
name: "secp256k1 prime-1 * 2",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
in2: "2",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
}, {
name: "secp256k1 prime * 3",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
in2: "3",
expected: "0",
}, {
name: "secp256k1 prime * 3",
in1: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
in2: "8",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc27",
}, {
name: "random sampling #1",
in1: "cfb81753d5ef499a98ecc04c62cb7768c2e4f1740032946db1c12e405248137e",
in2: "58f355ad27b4d75fb7db0442452e732c436c1f7c5a7c4e214fa9cc031426a7d3",
expected: "1018cd2d7c2535235b71e18db9cd98027386328d2fa6a14b36ec663c4c87282b",
}, {
name: "random sampling #2",
in1: "26e9d61d1cdf3920e9928e85fa3df3e7556ef9ab1d14ec56d8b4fc8ed37235bf",
in2: "2dfc4bbe537afee979c644f8c97b31e58be5296d6dbc460091eae630c98511cf",
expected: "da85f48da2dc371e223a1ae63bd30b7e7ee45ae9b189ac43ff357e9ef8cf107a",
}, {
name: "random sampling #3",
in1: "5db64ed5afb71646c8b231585d5b2bf7e628590154e0854c4c29920b999ff351",
in2: "279cfae5eea5d09ade8e6a7409182f9de40981bc31c84c3d3dfe1d933f152e9a",
expected: "2c78fbae91792dd0b157abe3054920049b1879a7cc9d98cfda927d83be411b37",
}, {
name: "random sampling #4",
in1: "b66dfc1f96820b07d2bdbd559c19319a3a73c97ceb7b3d662f4fe75ecb6819e6",
in2: "bf774aba43e3e49eb63a6e18037d1118152568f1a3ac4ec8b89aeb6ff8008ae1",
expected: "c4f016558ca8e950c21c3f7fc15f640293a979c7b01754ee7f8b3340d4902ebb",
},
}
for _, test := range tests {
f1 := new(FieldVal).SetHex(test.in1).Normalize()
f2 := new(FieldVal).SetHex(test.in2).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
// Ensure multiplying the two values with the result going to another
// variable produces the expected result.
result := new(FieldVal).Mul2(f1, f2).Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: unexpected result\ngot: %v\nwant: %v", test.name,
result, expected,
)
continue
}
// Ensure multiplying the value to an existing field value produces the
// expected result.
f1.Mul(f2).Normalize()
if !f1.Equals(expected) {
t.Errorf(
"%s: unexpected result\ngot: %v\nwant: %v", test.name,
f1, expected,
)
continue
}
}
}
// TestFieldSquare ensures that squaring field values via Square and SqualVal
// works as expected.
func TestFieldSquare(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded value
expected string // expected hex encoded value
}{
{
name: "zero",
in: "0",
expected: "0",
}, {
name: "secp256k1 prime (direct val in with 0 out)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: "0",
}, {
name: "secp256k1 prime (0 in with direct val out)",
in: "0",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
}, {
name: "secp256k1 prime - 1",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
expected: "1",
}, {
name: "secp256k1 prime - 2",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
expected: "4",
}, {
name: "random sampling #1",
in: "b0ba920360ea8436a216128047aab9766d8faf468895eb5090fc8241ec758896",
expected: "133896b0b69fda8ce9f648b9a3af38f345290c9eea3cbd35bafcadf7c34653d3",
}, {
name: "random sampling #2",
in: "c55d0d730b1d0285a1599995938b042a756e6e8857d390165ffab480af61cbd5",
expected: "cd81758b3f5877cbe7e5b0a10cebfa73bcbf0957ca6453e63ee8954ab7780bee",
}, {
name: "random sampling #3",
in: "e89c1f9a70d93651a1ba4bca5b78658f00de65a66014a25544d3365b0ab82324",
expected: "39ffc7a43e5dbef78fd5d0354fb82c6d34f5a08735e34df29da14665b43aa1f",
}, {
name: "random sampling #4",
in: "7dc26186079d22bcbe1614aa20ae627e62d72f9be7ad1e99cac0feb438956f05",
expected: "bf86bcfc4edb3d81f916853adfda80c07c57745b008b60f560b1912f95bce8ae",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
// Ensure squaring the value with the result going to another variable
// produces the expected result.
result := new(FieldVal).SquareVal(f).Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: unexpected result\ngot: %v\nwant: %v", test.name,
result, expected,
)
continue
}
// Ensure self squaring an existing field value produces the expected
// result.
f.Square().Normalize()
if !f.Equals(expected) {
t.Errorf(
"%s: unexpected result\ngot: %v\nwant: %v", test.name,
f, expected,
)
continue
}
}
}
// TestFieldSquareRoot ensures that calculating the square root of field values
// via SquareRootVal works as expected for edge cases.
func TestFieldSquareRoot(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded value
valid bool // whether the value has a square root
want string // expected hex encoded value
}{
{
name: "secp256k1 prime (as 0 in and out)",
in: "0",
valid: true,
want: "0",
}, {
name: "secp256k1 prime (direct val with 0 out)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
valid: true,
want: "0",
}, {
name: "secp256k1 prime (as 0 in direct val out)",
in: "0",
valid: true,
want: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
}, {
name: "secp256k1 prime-1",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
valid: false,
want: "0000000000000000000000000000000000000000000000000000000000000001",
}, {
name: "secp256k1 prime-2",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
valid: false,
want: "210c790573632359b1edb4302c117d8a132654692c3feeb7de3a86ac3f3b53f7",
}, {
name: "(secp256k1 prime-2)^2",
in: "0000000000000000000000000000000000000000000000000000000000000004",
valid: true,
want: "0000000000000000000000000000000000000000000000000000000000000002",
}, {
name: "value 1",
in: "0000000000000000000000000000000000000000000000000000000000000001",
valid: true,
want: "0000000000000000000000000000000000000000000000000000000000000001",
}, {
name: "value 2",
in: "0000000000000000000000000000000000000000000000000000000000000002",
valid: true,
want: "210c790573632359b1edb4302c117d8a132654692c3feeb7de3a86ac3f3b53f7",
}, {
name: "random sampling 1",
in: "16fb970147a9acc73654d4be233cc48b875ce20a2122d24f073d29bd28805aca",
valid: false,
want: "6a27dcfca440cf7930a967be533b9620e397f122787c53958aaa7da7ad3d89a4",
}, {
name: "square of random sampling 1",
in: "f4a8c3738ace0a1c3abf77737ae737f07687b5e24c07a643398298bd96893a18",
valid: true,
want: "e90468feb8565338c9ab2b41dcc33b7478a31df5dedd2db0f8c2d641d77fa165",
}, {
name: "random sampling 2",
in: "69d1323ce9f1f7b3bd3c7320b0d6311408e30281e273e39a0d8c7ee1c8257919",
valid: true,
want: "61f4a7348274a52d75dfe176b8e3aaff61c1c833b6678260ba73def0fb2ad148",
}, {
name: "random sampling 3",
in: "e0debf988ae098ecda07d0b57713e97c6d213db19753e8c95aa12a2fc1cc5272",
valid: false,
want: "6e1cc9c311d33d901670135244f994b1ea39501f38002269b34ce231750cfbac",
}, {
name: "random sampling 4",
in: "dcd394f91f74c2ba16aad74a22bb0ed47fe857774b8f2d6c09e28bfb14642878",
valid: true,
want: "72b22fe6f173f8bcb21898806142ed4c05428601256eafce5d36c1b08fb82bab",
},
}
for _, test := range tests {
input := new(FieldVal).SetHex(test.in).Normalize()
want := new(FieldVal).SetHex(test.want).Normalize()
// Calculate the square root and enusre the validity flag matches the
// expected value.
var result FieldVal
isValid := result.SquareRootVal(input)
if isValid != test.valid {
t.Errorf(
"%s: mismatched validity -- got %v, want %v", test.name,
isValid, test.valid,
)
continue
}
// Ensure the calculated result matches the expected value.
result.Normalize()
if !result.Equals(want) {
t.Errorf(
"%s: d wrong result\ngot: %v\nwant: %v", test.name, result,
want,
)
continue
}
}
}
// TestFieldSquareRootRandom ensures that calculating the square root for random
// field values works as expected by also performing the same operation with big
// ints and comparing the results.
func TestFieldSquareRootRandom(t *testing.T) {
// Use a unique random seed each test instance and log it if the tests fail.
seed := time.Now().Unix()
rng := rand.New(rand.NewSource(seed))
defer func(t *testing.T, seed int64) {
if t.Failed() {
t.Logf("random seed: %d", seed)
}
}(t, seed)
for i := 0; i < 100; i++ {
// Generate big integer and field value with the same random value.
bigIntVal, fVal := randIntAndFieldVal(t, rng)
// Calculate the square root of the value using big ints.
bigIntResult := new(big.Int).ModSqrt(bigIntVal, curveParams.P)
bigIntHasSqrt := bigIntResult != nil
// Calculate the square root of the value using a field value.
var fValResult FieldVal
fValHasSqrt := fValResult.SquareRootVal(fVal)
// Ensure they match.
if bigIntHasSqrt != fValHasSqrt {
t.Fatalf(
"mismatched square root existence\nbig int in: %x\nfield "+
"in: %v\nbig int result: %v\nfield result %v", bigIntVal,
fVal,
bigIntHasSqrt, fValHasSqrt,
)
}
if !fValHasSqrt {
continue
}
bigIntResultHex := fmt.Sprintf("%064x", bigIntResult)
fieldValResultHex := fmt.Sprintf("%v", fValResult)
if bigIntResultHex != fieldValResultHex {
t.Fatalf(
"mismatched square root\nbig int in: %x\nfield in: %v\n"+
"big int result: %x\nfield result %v", bigIntVal, fVal,
bigIntResult, fValResult,
)
}
}
}
// TestFieldInverse ensures that finding the multiplicative inverse via Inverse
// works as expected.
func TestFieldInverse(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded value
expected string // expected hex encoded value
}{
{
name: "zero",
in: "0",
expected: "0",
}, {
name: "secp256k1 prime (direct val in with 0 out)",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
expected: "0",
}, {
name: "secp256k1 prime (0 in with direct val out)",
in: "0",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f",
}, {
name: "secp256k1 prime - 1",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
expected: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2e",
}, {
name: "secp256k1 prime - 2",
in: "fffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2d",
expected: "7fffffffffffffffffffffffffffffffffffffffffffffffffffffff7ffffe17",
}, {
name: "random sampling #1",
in: "16fb970147a9acc73654d4be233cc48b875ce20a2122d24f073d29bd28805aca",
expected: "987aeb257b063df0c6d1334051c47092b6d8766c4bf10c463786d93f5bc54354",
}, {
name: "random sampling #2",
in: "69d1323ce9f1f7b3bd3c7320b0d6311408e30281e273e39a0d8c7ee1c8257919",
expected: "49340981fa9b8d3dad72de470b34f547ed9179c3953797d0943af67806f4bb6",
}, {
name: "random sampling #3",
in: "e0debf988ae098ecda07d0b57713e97c6d213db19753e8c95aa12a2fc1cc5272",
expected: "64f58077b68af5b656b413ea366863f7b2819f8d27375d9c4d9804135ca220c2",
}, {
name: "random sampling #4",
in: "dcd394f91f74c2ba16aad74a22bb0ed47fe857774b8f2d6c09e28bfb14642878",
expected: "fb848ec64d0be572a63c38fe83df5e7f3d032f60bf8c969ef67d36bf4ada22a9",
},
}
for _, test := range tests {
f := new(FieldVal).SetHex(test.in).Normalize()
expected := new(FieldVal).SetHex(test.expected).Normalize()
result := f.Inverse().Normalize()
if !result.Equals(expected) {
t.Errorf(
"%s: d wrong result\ngot: %v\nwant: %v", test.name, result,
expected,
)
continue
}
}
}
// TestFieldIsGtOrEqPrimeMinusOrder ensures that field values report whether or
// not they are greater than or equal to the field prime minus the group order
// as expected for edge cases.
func TestFieldIsGtOrEqPrimeMinusOrder(t *testing.T) {
tests := []struct {
name string // test description
in string // hex encoded test value
expected bool // expected result
}{
{
name: "zero",
in: "0",
expected: false,
}, {
name: "one",
in: "1",
expected: false,
}, {
name: "p - n - 1",
in: "14551231950b75fc4402da1722fc9baed",
expected: false,
}, {
name: "p - n",
in: "14551231950b75fc4402da1722fc9baee",
expected: true,
}, {
name: "p - n + 1",
in: "14551231950b75fc4402da1722fc9baef",
expected: true,
}, {
name: "over p - n word one",
in: "14551231950b75fc4402da17233c9baee",
expected: true,
}, {
name: "over p - n word two",
in: "14551231950b75fc4403da1722fc9baee",
expected: true,
}, {
name: "over p - n word three",
in: "14551231950b79fc4402da1722fc9baee",
expected: true,
}, {
name: "over p - n word four",
in: "14551241950b75fc4402da1722fc9baee",
expected: true,
}, {
name: "over p - n word five",
in: "54551231950b75fc4402da1722fc9baee",
expected: true,
}, {
name: "over p - n word six",
in: "100000014551231950b75fc4402da1722fc9baee",
expected: true,
}, {
name: "over p - n word seven",
in: "000000000000000000400000000000014551231950b75fc4402da1722fc9baee",
expected: true,
}, {
name: "over p - n word eight",
in: "000000000001000000000000000000014551231950b75fc4402da1722fc9baee",
expected: true,
}, {
name: "over p - n word nine",
in: "000004000000000000000000000000014551231950b75fc4402da1722fc9baee",
expected: true,
},
}
for _, test := range tests {
result := new(FieldVal).SetHex(test.in).IsGtOrEqPrimeMinusOrder()
if result != test.expected {
t.Errorf(
"%s: unexpected result -- got: %v, want: %v", test.name,
result, test.expected,
)
continue
}
}
}
// TestFieldIsGtOrEqPrimeMinusOrderRandom ensures that field values report
// whether or not they are greater than or equal to the field prime minus the
// group order as expected by also performing the same operation with big ints
// and comparing the results.
func TestFieldIsGtOrEqPrimeMinusOrderRandom(t *testing.T) {
// Use a unique random seed each test instance and log it if the tests fail.
seed := time.Now().Unix()
rng := rand.New(rand.NewSource(seed))
defer func(t *testing.T, seed int64) {
if t.Failed() {
t.Logf("random seed: %d", seed)
}
}(t, seed)
bigPMinusN := new(big.Int).Sub(curveParams.P, curveParams.N)
for i := 0; i < 100; i++ {
// Generate big integer and field value with the same random value.
bigIntVal, fVal := randIntAndFieldVal(t, rng)
// Determine the value is greater than or equal to the prime minus the
// order using big ints.
bigIntResult := bigIntVal.Cmp(bigPMinusN) >= 0
// Determine the value is greater than or equal to the prime minus the
// order using a field value.
fValResult := fVal.IsGtOrEqPrimeMinusOrder()
// Ensure they match.
if bigIntResult != fValResult {
t.Fatalf(
"mismatched is gt or eq prime minus order\nbig int in: "+
"%x\nscalar in: %v\nbig int result: %v\nscalar result %v",
bigIntVal, fVal, bigIntResult, fValResult,
)
}
}
}