比特币地址生成算法之公钥和私钥（下）区块链maxdaic的专栏-

话不多说，公钥也分为压缩公钥和非压缩公钥。

 非压缩公钥： 0x04 + X + Y 压缩公钥： 如果Y是奇数，压缩公钥为0x03+X；如果Y为偶数，压缩公钥为0x02+X

功能代码如下：

 func NewCompressPubKey(X []byte, Y []byte) string {  //前缀03+x(如果y是奇数)，前缀02+x(如果y是偶数)  var prefix byte  if Y[len(Y)-1] %2 != 0 {   prefix = 0x3  } else {   prefix = 0x2  }  var pubKeyInBytes []byte  pubKeyInBytes = append([]byte{prefix}, X...)  return hex.EncodeToString(pubKeyInBytes) }  func NewUncompressPubKey(X []byte, Y []byte) string {  //0X04 + X + Y  var pubKeyInBytes []byte  pubKeyInBytes = append([]byte{0x04}, X...)  pubKeyInBytes = append(pubKeyInBytes, Y...)  return hex.EncodeToString(pubKeyInBytes) }

测试代码如下：

 import (  "encoding/hex"  "github.com/decred/dcrd/dcrec/secp256k1"  "testing" )  func TestNewUncompressPubKey(t *testing.T) {  var testcases = []struct{   originalPrivKey string   compressedPubKey string  } {   {    "5a2d2535d6f40cb64bc76c33551b2a1d7b4c5222893d2dc93590c55128f788b2",    "02e92a351210716373fc214b8320c04a50e35f64eba23b92a812c8e52777ae79c5",   },  }   for _,oneCase := range testcases {   privKeyInBytes, _ := hex.DecodeString(oneCase.originalPrivKey)   privKey := secp256k1.PrivKeyFromBytes(privKeyInBytes)   compressedPubKey := NewCompressPubKey(privKey.PubKey().X().Bytes(), privKey.PubKey().Y().Bytes())    if compressedPubKey != oneCase.compressedPubKey {    t.Error("compressed public key error")    t.Error("want: ", oneCase.compressedPubKey)    t.Error("got:  ", compressedPubKey)   }  } }  func TestNewCompressPubKey(t *testing.T) {  var testcases = []struct{   originalPrivKey string   uncompressedPubKey string  } {   {    "5a2d2535d6f40cb64bc76c33551b2a1d7b4c5222893d2dc93590c55128f788b2",    "04e92a351210716373fc214b8320c04a50e35f64eba23b92a812c8e52777ae79c53cc2bec2369a33918f2ae6680ef0ff03056cae8849466556959c8784b07fdc0a",   },  }   for _,oneCase := range testcases {   privKeyInBytes, _ := hex.DecodeString(oneCase.originalPrivKey)   privKey := secp256k1.PrivKeyFromBytes(privKeyInBytes)   uncompressedPubKey := NewUncompressPubKey(privKey.PubKey().X().Bytes(), privKey.PubKey().Y().Bytes())    if uncompressedPubKey != oneCase.uncompressedPubKey {    t.Error("uncompressed public key error")    t.Error("want: ", oneCase.uncompressedPubKey)    t.Error("got:  ", uncompressedPubKey)   }  } }  

 如果想增加更多的测试用例，可以访问一下下面这个网址：

https://learnmeabitcoin.com/guide/public-key

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