比特幣地址生成全步驟(golang實現)

比特幣地址生成全過程

1. 通過橢圓曲線算法生成公鑰
2. 對公鑰進行sha256散列和ripemd160散列,獲得publickeyHash
3. 在publickeyHash前面加上version(版本)字節數組獲得versionPublickeyHash
4. 對versionPublickeyHash進行兩次sha256散列並取前４位字節，獲得tailfHash
5. 將tailfHash拼接到versionPublickeyHash後面，獲得公鑰的最終Hash即finalHash
6. 最後將finalHash進行Base58編碼(一種可視化工具)得到比特幣地址

曾經有個疑問，爲何比特幣生成地址要這麼麻煩，既然非對稱加密只擁有公鑰是無法倒推出私鑰的，爲何不直接使用公鑰當地址，而是對公鑰進行hash多次來取得地址，直到最近看了篇文章才明白，該文章提到量子計算機是可以破解橢圓曲線加密的，他可以通過公鑰快速尋找到私鑰信息。但是量子計算機很難逆轉Hash算法(或者說需要2的80次方個步驟來破解Hash)，所以你的比特幣放在一個未支付過的地址中(根據UTXO交易模型，輸出存的是公鑰Hash而不是公鑰,這同樣解釋了爲何UTXO輸入存的是公鑰而輸出存的是公鑰Hash)是相當安全的。也就是說已有花費的地址在面對量子計算機面前是不安全的，沒有花費的地址有較強的抗量子性。

代碼實現：

package main

import (
	"bytes"
	"math/big"
)

var b58Alphabet = []byte("123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz")

func Base58Encode(input []byte) []byte {
	var result []byte

	x := big.NewInt(0).SetBytes(input)

	base := big.NewInt(int64(len(b58Alphabet)))
	zero := big.NewInt(0)
	mod := &big.Int{}

	for x.Cmp(zero) != 0 {
		x.DivMod(x, base, mod)
		result = append(result, b58Alphabet[mod.Int64()])
	}

	ReverseBytes(result)

	for _, b := range input {
		if b == 0x00 {
			result = append([]byte{b58Alphabet[0]}, result...)
		} else {
			break
		}
	}
	return result

}

func Base58Decode(input []byte) []byte {
	result := big.NewInt(0)
	zeroBytes := 0
	for _, b := range input {
		if b != b58Alphabet[0] {
			break
		}
		zeroBytes++
	}
	payload := input[zeroBytes:]
	for _, b := range payload {
		charIndex := bytes.IndexByte(b58Alphabet, b)
		result.Mul(result, big.NewInt(int64(len(b58Alphabet))))
		result.Add(result, big.NewInt(int64(charIndex)))
	}

	decoded := result.Bytes()
	decoded = append(bytes.Repeat([]byte{byte(0x00)}, zeroBytes), decoded...)

	return decoded
}

func ReverseBytes(data []byte) {
	for i, j := 0, len(data)-1; i < j; i, j = i+1, j-1 {
		data[i], data[j] = data[j], data[i]
	}
}

package main

import (
	"bytes"
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"crypto/sha256"
	"fmt"
	"golang.org/x/crypto/ripemd160"
	"log"
)

const VERSION = byte(0x00)
const CHECKSUM_LENGTH = 4

type BitcoinKeys struct {
	PrivateKey *ecdsa.PrivateKey
	PublicKey  []byte
}

func GetBitcoinKeys() *BitcoinKeys {
	b := &BitcoinKeys{nil, nil}
	b.newKeyPair()
	return b
}

func (b *BitcoinKeys) newKeyPair() {
	curve := elliptic.P256()
	var err error
	b.PrivateKey, err = ecdsa.GenerateKey(curve, rand.Reader)
	if err != nil {
		log.Panic(err)
	}
	b.PublicKey = append(b.PrivateKey.PublicKey.X.Bytes(), b.PrivateKey.PublicKey.Y.Bytes()...)
}

//獲取地址
func (b *BitcoinKeys) GetAddress() []byte {
	//1.ripemd160(sha256(publickey))
	ripPubKey := GeneratePublicKeyHash(b.PublicKey)
	//2.最前面添加一個字節的版本信息獲得 versionPublickeyHash
	versionPublickeyHash := append([]byte{VERSION}, ripPubKey[:]...)
	//3.sha256(sha256(versionPublickeyHash))  取最後四個字節的值
	tailHash := CheckSumHash(versionPublickeyHash)
	//4.拼接最終hash versionPublickeyHash + checksumHash
	finalHash := append(versionPublickeyHash, tailHash...)
	//進行base58加密
	address := Base58Encode(finalHash)
	return address
}

func GeneratePublicKeyHash(publicKey []byte) []byte {
	sha256PubKey := sha256.Sum256(publicKey)
	r := ripemd160.New()
	r.Write(sha256PubKey[:])
	ripPubKey := r.Sum(nil)
	return ripPubKey
}

//通過地址獲得公鑰
func GetPublicKeyHashFromAddress(address string) []byte {
	addressBytes := []byte(address)
	fullHash := Base58Decode(addressBytes)
	publicKeyHash := fullHash[1 : len(fullHash)-CHECKSUM_LENGTH]
	return publicKeyHash
}

func CheckSumHash(versionPublickeyHash []byte) []byte {
	versionPublickeyHashSha1 := sha256.Sum256(versionPublickeyHash)
	versionPublickeyHashSha2 := sha256.Sum256(versionPublickeyHashSha1[:])
	tailHash := versionPublickeyHashSha2[:CHECKSUM_LENGTH]
	return tailHash
}

//檢測比特幣地址是否有效
func IsVaildBitcoinAddress(address string) bool {
	adddressByte := []byte(address)
	fullHash := Base58Decode(adddressByte)
	if len(fullHash) != 25 {
		return false
	}
	prefixHash := fullHash[:len(fullHash)-CHECKSUM_LENGTH]
	tailHash := fullHash[len(fullHash)-CHECKSUM_LENGTH:]
	tailHash2 := CheckSumHash(prefixHash)
	if bytes.Compare(tailHash, tailHash2[:]) == 0 {
		return true
	} else {
		return false
	}
}

func main() {
	keys := GetBitcoinKeys()
	bitcoinAddress := keys.GetAddress()
	fmt.Println("比特幣地址:", string(bitcoinAddress))
	fmt.Printf("比特幣地址是否有效:%v\n：", IsVaildBitcoinAddress(string(bitcoinAddress)))
}

運行結果：

比特幣地址: 1BeDkWNHxvVc8DmpLVpFRPUngPmG7uCRHJ
比特幣地址是否有效:true