github.com/turingchain2020/turingchain@v1.1.21/wallet/bipwallet/btcutilecc/arith.go (about)

     1  // Copyright Turing Corp. 2018 All Rights Reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Package btcutil Utility functions for Bitcoin elliptic curve cryptography.
     6  package btcutil
     7  
     8  import (
     9  	"crypto/ecdsa"
    10  	"math/big"
    11  )
    12  
    13  // ScalarBaseMult Multiplies the base G by a large integer.  The resulting
    14  // point is represented as an ECDSA public key since that's
    15  // typically how they're used.
    16  func ScalarBaseMult(k *big.Int) *ecdsa.PublicKey {
    17  	key := new(ecdsa.PublicKey)
    18  	key.Curve = Secp256k1()
    19  	key.X, key.Y = Secp256k1().ScalarBaseMult(k.Bytes())
    20  	return key
    21  }
    22  
    23  // ScalarMult Multiply a large integer and a point.  The resulting point
    24  // is represented as an ECDSA public key.
    25  func ScalarMult(k *big.Int, B *ecdsa.PublicKey) *ecdsa.PublicKey {
    26  	key := new(ecdsa.PublicKey)
    27  	key.Curve = Secp256k1()
    28  	key.X, key.Y = Secp256k1().ScalarMult(B.X, B.Y, k.Bytes())
    29  	return key
    30  }
    31  
    32  // Add Adds two points to create a third.  Points are represented as
    33  // ECDSA public keys.
    34  func Add(a, b *ecdsa.PublicKey) *ecdsa.PublicKey {
    35  	key := new(ecdsa.PublicKey)
    36  	key.Curve = Secp256k1()
    37  	key.X, key.Y = Secp256k1().Add(a.X, a.Y, b.X, b.Y)
    38  	return key
    39  }