@ -1,15 +1,16 @@
// Package babyjub eddsa implements the EdDSA over the BabyJubJub curve
//nolint:gomnd
package babyjub
import (
"crypto/rand"
"database/sql/driver"
"fmt"
"math/big"
"github.com/iden3/go-iden3-crypto/mimc7"
"github.com/iden3/go-iden3-crypto/poseidon"
"github.com/iden3/go-iden3-crypto/utils"
"math/big"
)
// pruneBuffer prunes the buffer during key generation according to RFC 8032.
@ -55,7 +56,7 @@ func SkToBigInt(k *PrivateKey) *big.Int {
return s
}
// Pub returns the public key corresponding to a private key.
// Public returns the public key corresponding to a private key.
func ( k * PrivateKey ) Public ( ) * PublicKey {
return k . Scalar ( ) . Public ( )
}
@ -69,8 +70,8 @@ func NewPrivKeyScalar(s *big.Int) *PrivKeyScalar {
return & sk
}
// Pub returns the public key corresponding to the scalar value s of a private
// key.
// Public returns the public key corresponding to the scalar value s of a
// private key.
func ( s * PrivKeyScalar ) Public ( ) * PublicKey {
p := NewPoint ( ) . Mul ( ( * big . Int ) ( s ) , B8 )
pk := PublicKey ( * p )
@ -85,16 +86,19 @@ func (s *PrivKeyScalar) BigInt() *big.Int {
// PublicKey represents an EdDSA public key, which is a curve point.
type PublicKey Point
// MarshalText implements the marshaler for PublicKey
func ( pk PublicKey ) MarshalText ( ) ( [ ] byte , error ) {
pkc := pk . Compress ( )
return utils . Hex ( pkc [ : ] ) . MarshalText ( )
}
// String returns the string representation of the PublicKey
func ( pk PublicKey ) String ( ) string {
pkc := pk . Compress ( )
return utils . Hex ( pkc [ : ] ) . String ( )
}
// UnmarshalText implements the unmarshaler for the PublicKey
func ( pk * PublicKey ) UnmarshalText ( h [ ] byte ) error {
var pkc PublicKeyComp
if err := utils . HexDecodeInto ( pkc [ : ] , h ) ; err != nil {
@ -109,24 +113,35 @@ func (pk *PublicKey) UnmarshalText(h []byte) error {
}
// Point returns the Point corresponding to a PublicKey.
func ( p * PublicKey ) Point ( ) * Point {
return ( * Point ) ( p )
func ( pk * PublicKey ) Point ( ) * Point {
return ( * Point ) ( pk )
}
// PublicKeyComp represents a compressed EdDSA Public key; it's a compressed curve
// point.
type PublicKeyComp [ 32 ] byte
func ( buf PublicKeyComp ) MarshalText ( ) ( [ ] byte , error ) { return utils . Hex ( buf [ : ] ) . MarshalText ( ) }
func ( buf PublicKeyComp ) String ( ) string { return utils . Hex ( buf [ : ] ) . String ( ) }
func ( buf * PublicKeyComp ) UnmarshalText ( h [ ] byte ) error { return utils . HexDecodeInto ( buf [ : ] , h ) }
// MarshalText implements the marshaler for the PublicKeyComp
func ( pkComp PublicKeyComp ) MarshalText ( ) ( [ ] byte , error ) {
return utils . Hex ( pkComp [ : ] ) . MarshalText ( )
}
// String returns the string representation of the PublicKeyComp
func ( pkComp PublicKeyComp ) String ( ) string { return utils . Hex ( pkComp [ : ] ) . String ( ) }
func ( p * PublicKey ) Compress ( ) PublicKeyComp {
return PublicKeyComp ( ( * Point ) ( p ) . Compress ( ) )
// UnmarshalText implements the unmarshaler for the PublicKeyComp
func ( pkComp * PublicKeyComp ) UnmarshalText ( h [ ] byte ) error {
return utils . HexDecodeInto ( pkComp [ : ] , h )
}
func ( p * PublicKeyComp ) Decompress ( ) ( * PublicKey , error ) {
point , err := NewPoint ( ) . Decompress ( * p )
// Compress returns the PublicKeyCompr for the given PublicKey
func ( pk * PublicKey ) Compress ( ) PublicKeyComp {
return PublicKeyComp ( ( * Point ) ( pk ) . Compress ( ) )
}
// Decompress returns the PublicKey for the given PublicKeyComp
func ( pkComp * PublicKeyComp ) Decompress ( ) ( * PublicKey , error ) {
point , err := NewPoint ( ) . Decompress ( * pkComp )
if err != nil {
return nil , err
}
@ -143,9 +158,18 @@ type Signature struct {
// SignatureComp represents a compressed EdDSA signature.
type SignatureComp [ 64 ] byte
func ( buf SignatureComp ) MarshalText ( ) ( [ ] byte , error ) { return utils . Hex ( buf [ : ] ) . MarshalText ( ) }
func ( buf SignatureComp ) String ( ) string { return utils . Hex ( buf [ : ] ) . String ( ) }
func ( buf * SignatureComp ) UnmarshalText ( h [ ] byte ) error { return utils . HexDecodeInto ( buf [ : ] , h ) }
// MarshalText implements the marshaler for the SignatureComp
func ( sComp SignatureComp ) MarshalText ( ) ( [ ] byte , error ) {
return utils . Hex ( sComp [ : ] ) . MarshalText ( )
}
// String returns the string representation of the SignatureComp
func ( sComp SignatureComp ) String ( ) string { return utils . Hex ( sComp [ : ] ) . String ( ) }
// UnmarshalText implements the unmarshaler for the SignatureComp
func ( sComp * SignatureComp ) UnmarshalText ( h [ ] byte ) error {
return utils . HexDecodeInto ( sComp [ : ] , h )
}
// Compress an EdDSA signature by concatenating the compression of
// the point R8 and the Little-Endian encoding of S.
@ -173,12 +197,12 @@ func (s *Signature) Decompress(buf [64]byte) (*Signature, error) {
// Decompress a compressed signature. Returns error if the Point decompression
// fails.
func ( s * SignatureComp ) Decompress ( ) ( * Signature , error ) {
return new ( Signature ) . Decompress ( * s )
func ( sComp * SignatureComp ) Decompress ( ) ( * Signature , error ) {
return new ( Signature ) . Decompress ( * sComp )
}
// Scan implements Scanner for database/sql.
func ( s * SignatureComp ) Scan ( src interface { } ) error {
func ( sComp * SignatureComp ) Scan ( src interface { } ) error {
srcB , ok := src . ( [ ] byte )
if ! ok {
return fmt . Errorf ( "can't scan %T into Signature" , src )
@ -186,13 +210,13 @@ func (s *SignatureComp) Scan(src interface{}) error {
if len ( srcB ) != 64 {
return fmt . Errorf ( "can't scan []byte of len %d into Signature, want %d" , len ( srcB ) , 64 )
}
copy ( s [ : ] , srcB [ : ] )
copy ( sComp [ : ] , srcB [ : ] )
return nil
}
// Value implements valuer for database/sql.
func ( s SignatureComp ) Value ( ) ( driver . Value , error ) {
return s [ : ] , nil
func ( sComp SignatureComp ) Value ( ) ( driver . Value , error ) {
return sComp [ : ] , nil
}
// Scan implements Scanner for database/sql.
@ -243,8 +267,8 @@ func (k *PrivateKey) SignMimc7(msg *big.Int) *Signature {
// VerifyMimc7 verifies the signature of a message encoded as a big.Int in Zq
// using blake-512 hash for buffer hashing and mimc7 for big.Int hashing.
func ( p * PublicKey ) VerifyMimc7 ( msg * big . Int , sig * Signature ) bool {
hmInput := [ ] * big . Int { sig . R8 . X , sig . R8 . Y , p . X , p . Y , msg }
func ( pk * PublicKey ) VerifyMimc7 ( msg * big . Int , sig * Signature ) bool {
hmInput := [ ] * big . Int { sig . R8 . X , sig . R8 . Y , pk . X , pk . Y , msg }
hm , err := mimc7 . Hash ( hmInput , nil ) // hm = H1(8*R.x, 8*R.y, A.x, A.y, msg)
if err != nil {
return false
@ -253,7 +277,7 @@ func (p *PublicKey) VerifyMimc7(msg *big.Int, sig *Signature) bool {
left := NewPoint ( ) . Mul ( sig . S , B8 ) // left = s * 8 * B
r1 := big . NewInt ( 8 )
r1 . Mul ( r1 , hm )
right := NewPoint ( ) . Mul ( r1 , p . Point ( ) )
right := NewPoint ( ) . Mul ( r1 , pk . Point ( ) )
rightProj := right . Projective ( )
rightProj . Add ( sig . R8 . Projective ( ) , rightProj ) // right = 8 * R + 8 * hm * A
right = rightProj . Affine ( )
@ -289,8 +313,8 @@ func (k *PrivateKey) SignPoseidon(msg *big.Int) *Signature {
// VerifyPoseidon verifies the signature of a message encoded as a big.Int in Zq
// using blake-512 hash for buffer hashing and Poseidon for big.Int hashing.
func ( p * PublicKey ) VerifyPoseidon ( msg * big . Int , sig * Signature ) bool {
hmInput := [ ] * big . Int { sig . R8 . X , sig . R8 . Y , p . X , p . Y , msg }
func ( pk * PublicKey ) VerifyPoseidon ( msg * big . Int , sig * Signature ) bool {
hmInput := [ ] * big . Int { sig . R8 . X , sig . R8 . Y , pk . X , pk . Y , msg }
hm , err := poseidon . Hash ( hmInput ) // hm = H1(8*R.x, 8*R.y, A.x, A.y, msg)
if err != nil {
return false
@ -299,7 +323,7 @@ func (p *PublicKey) VerifyPoseidon(msg *big.Int, sig *Signature) bool {
left := NewPoint ( ) . Mul ( sig . S , B8 ) // left = s * 8 * B
r1 := big . NewInt ( 8 )
r1 . Mul ( r1 , hm )
right := NewPoint ( ) . Mul ( r1 , p . Point ( ) )
right := NewPoint ( ) . Mul ( r1 , pk . Point ( ) )
rightProj := right . Projective ( )
rightProj . Add ( sig . R8 . Projective ( ) , rightProj ) // right = 8 * R + 8 * hm * A
right = rightProj . Affine ( )
@ -307,7 +331,7 @@ func (p *PublicKey) VerifyPoseidon(msg *big.Int, sig *Signature) bool {
}
// Scan implements Scanner for database/sql.
func ( p * PublicKey ) Scan ( src interface { } ) error {
func ( pk * PublicKey ) Scan ( src interface { } ) error {
srcB , ok := src . ( [ ] byte )
if ! ok {
return fmt . Errorf ( "can't scan %T into PublicKey" , src )
@ -321,12 +345,12 @@ func (p *PublicKey) Scan(src interface{}) error {
if err != nil {
return err
}
* p = * decomp
* pk = * decomp
return nil
}
// Value implements valuer for database/sql.
func ( p PublicKey ) Value ( ) ( driver . Value , error ) {
comp := p . Compress ( )
func ( pk PublicKey ) Value ( ) ( driver . Value , error ) {
comp := pk . Compress ( )
return comp [ : ] , nil
}
