github.com/igggame/nebulas-go@v2.1.0+incompatible/crypto/keystore/secp256k1/signature.go (about)

     1  // Copyright (C) 2017 go-nebulas authors
     2  //
     3  // This file is part of the go-nebulas library.
     4  //
     5  // the go-nebulas library is free software: you can redistribute it and/or modify
     6  // it under the terms of the GNU General Public License as published by
     7  // the Free Software Foundation, either version 3 of the License, or
     8  // (at your option) any later version.
     9  //
    10  // the go-nebulas library is distributed in the hope that it will be useful,
    11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13  // GNU General Public License for more details.
    14  //
    15  // You should have received a copy of the GNU General Public License
    16  // along with the go-nebulas library.  If not, see <http://www.gnu.org/licenses/>.
    17  //
    18  
    19  package secp256k1
    20  
    21  import (
    22  	"errors"
    23  
    24  	"github.com/nebulasio/go-nebulas/crypto/keystore"
    25  )
    26  
    27  // Signature signature ecdsa
    28  type Signature struct {
    29  	privateKey *PrivateKey
    30  
    31  	publicKey *PublicKey
    32  }
    33  
    34  // Algorithm secp256k1 algorithm
    35  func (s *Signature) Algorithm() keystore.Algorithm {
    36  	return keystore.SECP256K1
    37  }
    38  
    39  // InitSign ecdsa init sign
    40  func (s *Signature) InitSign(priv keystore.PrivateKey) error {
    41  	s.privateKey = priv.(*PrivateKey)
    42  	return nil
    43  }
    44  
    45  // Sign ecdsa sign
    46  func (s *Signature) Sign(data []byte) (out []byte, err error) {
    47  	if s.privateKey == nil {
    48  		return nil, errors.New("please get private key first")
    49  	}
    50  	signature, err := s.privateKey.Sign(data)
    51  	if err != nil {
    52  		return nil, err
    53  	}
    54  	return signature, nil
    55  }
    56  
    57  // RecoverPublic returns a public key
    58  func (s *Signature) RecoverPublic(data []byte, signature []byte) (keystore.PublicKey, error) {
    59  	pub, err := RecoverECDSAPublicKey(data, signature)
    60  	if err != nil {
    61  		return nil, err
    62  	}
    63  	s.publicKey = NewPublicKey(pub)
    64  	return s.publicKey, nil
    65  }
    66  
    67  // InitVerify ecdsa verify init
    68  func (s *Signature) InitVerify(pub keystore.PublicKey) error {
    69  	s.publicKey = pub.(*PublicKey)
    70  	return nil
    71  }
    72  
    73  // Verify ecdsa verify
    74  func (s *Signature) Verify(data []byte, signature []byte) (bool, error) {
    75  	if s.publicKey == nil {
    76  		return false, errors.New("please give public key first")
    77  	}
    78  	return s.publicKey.Verify(data, signature)
    79  }