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Adapt babyjub/eddsa to new Poseidon methods

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This commit is contained in:
arnaucube
2020-03-03 16:32:49 +01:00
parent b45d8a582b
commit 2a3f0d9ed5
5 changed files with 79 additions and 63 deletions
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47
poseidon/poseidon.go
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@@ -5,6 +5,7 @@ import (
"math/big"
"strconv"
"github.com/iden3/go-iden3-crypto/constants"
"github.com/iden3/go-iden3-crypto/ff"
"github.com/iden3/go-iden3-crypto/utils"
"golang.org/x/crypto/blake2b"
@@ -19,7 +20,11 @@ var constC []*ff.Element
var constM [T][T]*ff.Element
func Zero() *ff.Element {
return utils.NewElement().SetZero()
return ff.NewElement().SetZero()
}
func modQ(v *big.Int) {
v.Mod(v, constants.Q)
}
func init() {
@@ -32,7 +37,7 @@ func getPseudoRandom(seed string, n int) []*ff.Element {
hash := blake2b.Sum256([]byte(seed))
for i := 0; i < n; i++ {
hashBigInt := big.NewInt(int64(0))
res[i] = utils.NewElement().SetBigInt(utils.SetBigIntFromLEBytes(hashBigInt, hash[:]))
res[i] = ff.NewElement().SetBigInt(utils.SetBigIntFromLEBytes(hashBigInt, hash[:]))
hash = blake2b.Sum256(hash[:])
}
return res
@@ -57,7 +62,7 @@ func getMDS() [T][T]*ff.Element {
var m [T][T]*ff.Element
for i := 0; i < T; i++ {
for j := 0; j < T; j++ {
m[i][j] = utils.NewElement().Sub(cauchyMatrix[i], cauchyMatrix[T+j])
m[i][j] = ff.NewElement().Sub(cauchyMatrix[i], cauchyMatrix[T+j])
m[i][j].Inverse(m[i][j])
}
}
@@ -66,7 +71,7 @@ func getMDS() [T][T]*ff.Element {
func checkAllDifferent(v []*ff.Element) bool {
for i := 0; i < len(v); i++ {
if v[i].Equal(utils.NewElement().SetZero()) {
if v[i].Equal(ff.NewElement().SetZero()) {
return false
}
for j := i + 1; j < len(v); j++ {
@@ -117,13 +122,14 @@ func mix(state [T]*ff.Element, newState [T]*ff.Element, m [T][T]*ff.Element) {
}
// PoseidonHash computes the Poseidon hash for the given inputs
func PoseidonHash(inp [T]*ff.Element) (*ff.Element, error) {
if !utils.CheckElementArrayInField(inp[:]) {
func PoseidonHash(inpBI [T]*big.Int) (*big.Int, error) {
if !utils.CheckBigIntArrayInField(inpBI[:]) {
return nil, errors.New("inputs values not inside Finite Field")
}
inp := utils.BigIntArrayToElementArray(inpBI[:])
state := [T]*ff.Element{}
for i := 0; i < T; i++ {
state[i] = utils.NewElement().Set(inp[i])
state[i] = ff.NewElement().Set(inp[i])
}
// ARK --> SBox --> M, https://eprint.iacr.org/2019/458.pdf pag.5
@@ -137,19 +143,18 @@ func PoseidonHash(inp [T]*ff.Element) (*ff.Element, error) {
mix(state, newState, constM)
state, newState = newState, state
}
return state[0], nil
rE := state[0]
r := big.NewInt(0)
rE.ToBigIntRegular(r)
return r, nil
}
// Hash performs the Poseidon hash over a ff.Element array
// in chunks of 5 elements
func Hash(arr []*ff.Element) (*ff.Element, error) {
if !utils.CheckElementArrayInField(arr) {
return nil, errors.New("inputs values not inside Finite Field")
}
r := utils.NewElement().SetOne()
func Hash(arr []*big.Int) (*big.Int, error) {
r := big.NewInt(int64(1))
for i := 0; i < len(arr); i = i + T - 1 {
var toHash [T]*ff.Element
var toHash [T]*big.Int
j := 0
for ; j < T-1; j++ {
if i+j >= len(arr) {
@@ -160,14 +165,14 @@ func Hash(arr []*ff.Element) (*ff.Element, error) {
toHash[j] = r
j++
for ; j < T; j++ {
toHash[j] = Zero()
toHash[j] = big.NewInt(0)
}
ph, err := PoseidonHash(toHash)
if err != nil {
return nil, err
}
r.Add(r, ph)
modQ(r.Add(r, ph))
}
return r, nil
@@ -175,19 +180,19 @@ func Hash(arr []*ff.Element) (*ff.Element, error) {
// HashBytes hashes a msg byte slice by blocks of 31 bytes encoded as
// little-endian
func HashBytes(b []byte) (*ff.Element, error) {
func HashBytes(b []byte) (*big.Int, error) {
n := 31
bElems := make([]*ff.Element, 0, len(b)/n+1)
bElems := make([]*big.Int, 0, len(b)/n+1)
for i := 0; i < len(b)/n; i++ {
v := big.NewInt(int64(0))
utils.SetBigIntFromLEBytes(v, b[n*i:n*(i+1)])
bElems = append(bElems, utils.NewElement().SetBigInt(v))
bElems = append(bElems, v)
}
if len(b)%n != 0 {
v := big.NewInt(int64(0))
utils.SetBigIntFromLEBytes(v, b[(len(b)/n)*n:])
bElems = append(bElems, utils.NewElement().SetBigInt(v))
bElems = append(bElems, v)
}
return Hash(bElems)
}