GO加密函数封装

.idea/workspace.xml

@@ -2,10 +2,7 @@
 <project version="4">
   <component name="ChangeListManager">
     <list default="true" id="879b126a-5488-4e29-a4e1-3a8936e89a2d" name="默认的" comment="">
-      <change afterPath="$PROJECT_DIR$/.idea/vcs.xml" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/AES_CBC.go" beforeDir="false" afterPath="$PROJECT_DIR$/AES_CBC.go" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/DES_CBC.go" beforeDir="false" afterPath="$PROJECT_DIR$/DES_CBC.go" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/RsaCrypt.go" beforeDir="false" afterPath="$PROJECT_DIR$/RsaCrypt.go" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/GetECCKey.go" beforeDir="false" afterPath="$PROJECT_DIR$/GetECCKey.go" afterDir="false" />
     </list>
     <option name="EXCLUDED_CONVERTED_TO_IGNORED" value="true" />
     <option name="TRACKING_ENABLED" value="true" />
@@ -15,12 +12,24 @@
     <option name="LAST_RESOLUTION" value="IGNORE" />
   </component>
   <component name="FileEditorManager">
-    <leaf>
-      <file leaf-file-name="EccSign.go" pinned="false" current-in-tab="true">
-        <entry file="file://$PROJECT_DIR$/EccSign.go">
+    <leaf SIDE_TABS_SIZE_LIMIT_KEY="375">
+      <file leaf-file-name="ecies.go" pinned="false" current-in-tab="true">
+        <entry file="file://$PROJECT_DIR$/ecies.go">
           <provider selected="true" editor-type-id="text-editor">
-            <state relative-caret-position="837">
-              <caret line="82" lean-forward="true" selection-start-line="82" selection-end-line="82" />
+            <state relative-caret-position="7506">
+              <caret line="391" column="5" selection-start-line="391" selection-start-column="5" selection-end-line="391" selection-end-column="5" />
+            </state>
+          </provider>
+        </entry>
+      </file>
+      <file leaf-file-name="EccCrypt.go" pinned="false" current-in-tab="false">
+        <entry file="file://$PROJECT_DIR$/EccCrypt.go">
+          <provider selected="true" editor-type-id="text-editor">
+            <state relative-caret-position="-891">
+              <caret line="39" column="35" selection-start-line="39" selection-start-column="35" selection-end-line="39" selection-end-column="35" />
+              <folding>
+                <element signature="e#15#153#0" expanded="true" />
+              </folding>
             </state>
           </provider>
         </entry>
@@ -40,6 +49,8 @@
         <option value="$PROJECT_DIR$/DES_CBC.go" />
         <option value="$PROJECT_DIR$/GetECCKey.go" />
         <option value="$PROJECT_DIR$/EccSign.go" />
+        <option value="$PROJECT_DIR$/ecies.go" />
+        <option value="$PROJECT_DIR$/EccCrypt.go" />
       </list>
     </option>
   </component>
@@ -66,7 +77,6 @@
       <foldersAlwaysOnTop value="true" />
     </navigator>
     <panes>
-      <pane id="Scope" />
       <pane id="ProjectPane">
         <subPane>
           <expand>
@@ -78,6 +88,7 @@
           <select />
         </subPane>
       </pane>
+      <pane id="Scope" />
     </panes>
   </component>
   <component name="PropertiesComponent">
@@ -103,7 +114,7 @@
     <frame x="-8" y="-8" width="1456" height="886" extended-state="6" />
     <editor active="true" />
     <layout>
-      <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.21748555" />
+      <window_info active="true" content_ui="combo" id="Project" order="0" visible="true" weight="0.22182082" />
       <window_info anchor="bottom" id="TODO" order="6" />
       <window_info anchor="bottom" id="调试" order="7" />
       <window_info anchor="bottom" id="Event Log" order="7" side_tool="true" />
@@ -111,8 +122,8 @@
       <window_info anchor="bottom" id="Database Changes" order="7" show_stripe_button="false" />
       <window_info anchor="bottom" id="Version Control" order="7" show_stripe_button="false" />
       <window_info id="Structure" order="1" side_tool="true" weight="0.25" />
-      <window_info anchor="bottom" id="Terminal" order="7" />
       <window_info anchor="bottom" id="运行" order="7" />
+      <window_info anchor="bottom" id="Terminal" order="7" />
       <window_info id="Favorites" order="2" side_tool="true" />
       <window_info anchor="right" content_ui="combo" id="Hierarchy" order="2" weight="0.25" />
       <window_info anchor="bottom" id="Inspection" order="5" weight="0.4" />
@@ -132,6 +143,13 @@
     <option name="myLimit" value="2678400000" />
   </component>
   <component name="editorHistoryManager">
+    <entry file="file://$PROJECT_DIR$/EccSign.go">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="1971">
+          <caret line="82" lean-forward="true" selection-start-line="82" selection-end-line="82" />
+        </state>
+      </provider>
+    </entry>
     <entry file="file://$PROJECT_DIR$/GetRsakey.go">
       <provider selected="true" editor-type-id="text-editor" />
     </entry>
@@ -160,16 +178,6 @@
         </state>
       </provider>
     </entry>
-    <entry file="file://$PROJECT_DIR$/AES_CBC.go">
-      <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="1807">
-          <caret line="83" column="9" lean-forward="true" selection-start-line="83" selection-start-column="9" selection-end-line="83" selection-end-column="9" />
-          <folding>
-            <element signature="e#19#87#0" expanded="true" />
-          </folding>
-        </state>
-      </provider>
-    </entry>
     <entry file="file://$PROJECT_DIR$/RsaCrypt.go">
       <provider selected="true" editor-type-id="text-editor">
         <state relative-caret-position="-162">
@@ -199,8 +207,35 @@
     </entry>
     <entry file="file://$PROJECT_DIR$/EccSign.go">
       <provider selected="true" editor-type-id="text-editor">
-        <state relative-caret-position="837">
-          <caret line="82" lean-forward="true" selection-start-line="82" selection-end-line="82" />
+        <state relative-caret-position="1566">
+          <caret line="67" column="18" selection-start-line="67" selection-start-column="18" selection-end-line="67" selection-end-column="18" />
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/AES_CBC.go">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="592">
+          <caret line="83" column="9" lean-forward="true" selection-start-line="83" selection-start-column="9" selection-end-line="83" selection-end-column="9" />
+          <folding>
+            <element signature="e#19#87#0" expanded="true" />
+          </folding>
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/EccCrypt.go">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="-891">
+          <caret line="39" column="35" selection-start-line="39" selection-start-column="35" selection-end-line="39" selection-end-column="35" />
+          <folding>
+            <element signature="e#15#153#0" expanded="true" />
+          </folding>
+        </state>
+      </provider>
+    </entry>
+    <entry file="file://$PROJECT_DIR$/ecies.go">
+      <provider selected="true" editor-type-id="text-editor">
+        <state relative-caret-position="7506">
+          <caret line="391" column="5" selection-start-line="391" selection-start-column="5" selection-end-line="391" selection-end-column="5" />
         </state>
       </provider>
     </entry>

EccCrypt.go

@@ -0,0 +1,92 @@
+package wmgocrypt
+
+import (
+	"log"
+	"crypto/rand"
+	"encoding/pem"
+	"runtime"
+	"crypto/x509"
+	"crypto/ecdsa"
+)
+
+/*
+@Time : 2018/11/4 16:43 
+@Author : wuman
+@File : EccCrypt
+@Software: GoLand
+*/
+func init(){
+	log.SetFlags(log.Ldate|log.Lshortfile)
+}   //处理日志的格式
+//Ecc椭圆曲线的公钥加密，如果要解密对应着私钥解密
+/*func EccEnCrypt(plainText []byte,prv2 *ecies.PrivateKey)(crypText []byte,err error){
+
+	ct, err := ecies.Encrypt(rand.Reader, &prv2.PublicKey, plainText, nil, nil)
+	return ct, err
+}
+//直接解密
+func EccDeCrypt(cryptText []byte,prv2 *ecies.PrivateKey) ([]byte, error) {
+	pt, err := prv2.Decrypt(cryptText, nil, nil)
+	return pt, err
+}*/
+
+//传入公钥和明文用来加密
+func EccPublicEncrypt(plainText []byte,key []byte)( cryptText []byte,err error){  //用私钥解密
+	//1. pem 解码
+	block, _:= pem.Decode(key)
+
+	//防止用户传的密钥不正确导致panic,这里恢复程序并打印错误
+	defer func(){
+		if err:=recover();err!=nil{
+			switch err.(type){
+			case runtime.Error:
+				log.Println("runtime err:",err,"请检查密钥是否正确")
+			default:
+				log.Println("error:",err)
+			}
+		}
+	}()
+	//2. block中的Bytes是x509编码的内容, x509解码
+	tempPublicKey, _ := x509.ParsePKIXPublicKey(block.Bytes)
+	//解码得到ecdsa包中的私钥
+	//类型断言
+	publicKey1:=tempPublicKey.(*ecdsa.PublicKey)
+	//转换为以太坊包中的ecies包中的私钥
+	publicKey:=ImportECDSAPublic(publicKey1)
+	//用私钥来解密密文
+	crypttext,err:=Encrypt(rand.Reader, publicKey, plainText, nil, nil)
+
+	return  crypttext,err
+
+
+}
+
+//传入私钥和明文用来解密
+func EccPrivateDeCrypt(cryptText []byte,key []byte)( msg []byte,err error){  //用私钥解密
+	//1. pem 解码
+	block, _:= pem.Decode(key)
+
+	//防止用户传的密钥不正确导致panic,这里恢复程序并打印错误
+	defer func(){
+		if err:=recover();err!=nil{
+			switch err.(type){
+			case runtime.Error:
+				log.Println("runtime err:",err,"请检查密钥是否正确")
+			default:
+				log.Println("error:",err)
+			}
+		}
+	}()
+	//2. block中的Bytes是x509编码的内容, x509解码
+	tempPrivateKey, _ := x509.ParseECPrivateKey(block.Bytes)
+	//解码得到ecdsa包中的私钥
+	//转换为以太坊包中的ecies包中的私钥
+	privateKey:=ImportECDSA(tempPrivateKey)
+
+	//用私钥来解密密文
+	plainText,err:=privateKey.Decrypt(cryptText,nil,nil)
+
+	return plainText,err
+
+
+}

GetECCKey.go

@@ -22,7 +22,7 @@ func init(){
 //ECC椭圆曲线密钥对生成
 func GetEccKey(){
 	//1.生成密钥对
-	privateKey, _ := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
+	privateKey, _ := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 
 	//2.将密钥保存到相关的文件中
 	// x509标准编码

README.md

@@ -297,6 +297,52 @@ W/fnOWXyXQ7DB16jMSQ=
 
 > ECC椭圆曲线技术应用广泛，目前我国居民身份证数字签名技术就是使用的ECC，虚拟货币比特币和以太坊中也使用了ECC技术，后面我们会把ECC加密的方法也实现好。
 
+#### 4.3 ECC用作加密十用（非对称加密是用公钥来加密，私钥来解密的，由于GO标准包中没有实现ECC加密的接口，只实现了ECC数字签名的接口，我们找了以太坊源码中的ECC加密的使用方法，稍加改造了一下，拿过来用了，在这里调用了以太坊加密包里面的接口来实现ECC加密的方法，我们把加密的东西二次封装了一下，下载包后就可以直接使用）
+
+首先还是先得到公钥和私钥
+
+```
+func main(){
+    wmgocrypt.GetEccKey()
+}     //这里我们得到的密钥是通过P256曲线得到的，由于之前验证用别的曲线调用以太坊接口会报错
+```
+
+然后就可以快速使用了
+
+```
+func main(){
+	plainText:=[]byte("窗前明月光，疑是地上霜,ECC加密解密")
+
+	//这里传入的私钥和公钥是要用GetECCKey里面得到的私钥和公钥，如果自己封装的话，
+	// 获取密钥时传入的第一个参数是要用这条曲线elliptic.P256()，如果用别的会报无效公钥错误，
+	// 例如用P521()这条曲线
+	privateKey:=[]byte(`-----BEGIN WUMAN ECC PRIVATE KEY-----
+MHcCAQEEIKozbXD9G6bGPJ26cCAfEdLrqAe697F8SiLRMdqxzNQ5oAoGCCqGSM49
+AwEHoUQDQgAEk3/hltyR0r0J2Wkkhi4HaREJXS1vFooGpsKCbLvrdUW4peVIwKEW
++yC3/g2X7Q2A8ftJlYv2X4kDU180GhIQpA==
+-----END WUMAN ECC PRIVATE KEY-----
+`)
+	publicKey:=[]byte(`-----BEGIN WUMAN ECC PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEk3/hltyR0r0J2Wkkhi4HaREJXS1v
+FooGpsKCbLvrdUW4peVIwKEW+yC3/g2X7Q2A8ftJlYv2X4kDU180GhIQpA==
+-----END WUMAN ECC PUBLIC KEY-----
+`)
+
+	cryptText,_:=wmgocrypt.EccPublicEncrypt(plainText,publicKey)
+	fmt.Println("ECC传入公钥加密的密文为：",hex.EncodeToString(cryptText))
+
+	msg,err:=wmgocrypt.EccPrivateDeCrypt(cryptText,privateKey)
+	if err!=nil{
+		fmt.Println(err)
+	}
+	fmt.Println("ECC传入私钥解密后的明文为：",string(msg))
+
+
+}
+```
+
+![](image/16.png)
+
 ## 5.附带的哈希函数sha256和sha512使用非常简单
 
 #### 5.1 sh256的快速使用

ecies.go

@@ -0,0 +1,424 @@
+// Copyright (c) 2013 Kyle Isom <kyle@tyrfingr.is>
+// Copyright (c) 2012 The Go Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package wmgocrypt
+
+import (
+	"crypto/cipher"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/hmac"
+	"crypto/subtle"
+	"fmt"
+	"hash"
+	"io"
+	"math/big"
+	"crypto"
+	"crypto/sha256"
+	"crypto/aes"
+	"crypto/sha512"
+)
+
+var (
+	ErrImport                     = fmt.Errorf("ecies: failed to import key")
+	ErrInvalidCurve               = fmt.Errorf("ecies: invalid elliptic curve")
+	ErrInvalidParams              = fmt.Errorf("ecies: invalid ECIES parameters")
+	ErrInvalidPublicKey           = fmt.Errorf("ecies: invalid public key")
+	ErrSharedKeyIsPointAtInfinity = fmt.Errorf("ecies: shared key is point at infinity")
+	ErrSharedKeyTooBig            = fmt.Errorf("ecies: shared key params are too big")
+	ErrUnsupportedECIESParameters = fmt.Errorf("ecies: unsupported ECIES parameters")
+
+)
+
+// PublicKey is a representation of an elliptic curve public key.
+type PublicKey struct {
+	X *big.Int
+	Y *big.Int
+	elliptic.Curve
+	Params *ECIESParams
+}
+
+// Export an ECIES public key as an ECDSA public key.
+func (pub *PublicKey) ExportECDSA() *ecdsa.PublicKey {
+	return &ecdsa.PublicKey{Curve: pub.Curve, X: pub.X, Y: pub.Y}
+}
+
+// Import an ECDSA public key as an ECIES public key.
+func ImportECDSAPublic(pub *ecdsa.PublicKey) *PublicKey {
+	return &PublicKey{
+		X:      pub.X,
+		Y:      pub.Y,
+		Curve:  pub.Curve,
+		Params: ParamsFromCurve(pub.Curve),
+	}
+}
+
+// PrivateKey is a representation of an elliptic curve private key.
+type PrivateKey struct {
+	PublicKey
+	D *big.Int
+}
+
+// Export an ECIES private key as an ECDSA private key.
+func (prv *PrivateKey) ExportECDSA() *ecdsa.PrivateKey {
+	pub := &prv.PublicKey
+	pubECDSA := pub.ExportECDSA()
+	return &ecdsa.PrivateKey{PublicKey: *pubECDSA, D: prv.D}
+}
+
+// Import an ECDSA private key as an ECIES private key.
+func ImportECDSA(prv *ecdsa.PrivateKey) *PrivateKey {
+	pub := ImportECDSAPublic(&prv.PublicKey)
+	return &PrivateKey{*pub, prv.D}
+}
+
+// Generate an elliptic curve public / private keypair. If params is nil,
+// the recommended default parameters for the key will be chosen.
+func GenerateKey(rand io.Reader, curve elliptic.Curve, params *ECIESParams) (prv *PrivateKey, err error) {
+	pb, x, y, err := elliptic.GenerateKey(curve, rand)
+	if err != nil {
+		return
+	}
+	prv = new(PrivateKey)
+	prv.PublicKey.X = x
+	prv.PublicKey.Y = y
+	prv.PublicKey.Curve = curve
+	prv.D = new(big.Int).SetBytes(pb)
+	if params == nil {
+		params = ParamsFromCurve(curve)
+	}
+	prv.PublicKey.Params = params
+	return
+}
+
+// MaxSharedKeyLength returns the maximum length of the shared key the
+// public key can produce.
+func MaxSharedKeyLength(pub *PublicKey) int {
+	return (pub.Curve.Params().BitSize + 7) / 8
+}
+
+// ECDH key agreement method used to establish secret keys for encryption.
+func (prv *PrivateKey) GenerateShared(pub *PublicKey, skLen, macLen int) (sk []byte, err error) {
+	if prv.PublicKey.Curve != pub.Curve {
+		return nil, ErrInvalidCurve
+	}
+	if skLen+macLen > MaxSharedKeyLength(pub) {
+		return nil, ErrSharedKeyTooBig
+	}
+
+	x, _ := pub.Curve.ScalarMult(pub.X, pub.Y, prv.D.Bytes())
+	if x == nil {
+		return nil, ErrSharedKeyIsPointAtInfinity
+	}
+
+	sk = make([]byte, skLen+macLen)
+	skBytes := x.Bytes()
+	copy(sk[len(sk)-len(skBytes):], skBytes)
+	return sk, nil
+}
+
+var (
+	ErrKeyDataTooLong = fmt.Errorf("ecies: can't supply requested key data")
+	ErrSharedTooLong  = fmt.Errorf("ecies: shared secret is too long")
+	ErrInvalidMessage = fmt.Errorf("ecies: invalid message")
+)
+
+var (
+	big2To32   = new(big.Int).Exp(big.NewInt(2), big.NewInt(32), nil)
+	big2To32M1 = new(big.Int).Sub(big2To32, big.NewInt(1))
+)
+
+func incCounter(ctr []byte) {
+	if ctr[3]++; ctr[3] != 0 {
+		return
+	}
+	if ctr[2]++; ctr[2] != 0 {
+		return
+	}
+	if ctr[1]++; ctr[1] != 0 {
+		return
+	}
+	if ctr[0]++; ctr[0] != 0 {
+		return
+	}
+}
+
+// NIST SP 800-56 Concatenation Key Derivation Function (see section 5.8.1).
+func concatKDF(hash hash.Hash, z, s1 []byte, kdLen int) (k []byte, err error) {
+	if s1 == nil {
+		s1 = make([]byte, 0)
+	}
+
+	reps := ((kdLen + 7) * 8) / (hash.BlockSize() * 8)
+	if big.NewInt(int64(reps)).Cmp(big2To32M1) > 0 {
+		fmt.Println(big2To32M1)
+		return nil, ErrKeyDataTooLong
+	}
+
+	counter := []byte{0, 0, 0, 1}
+	k = make([]byte, 0)
+
+	for i := 0; i <= reps; i++ {
+		hash.Write(counter)
+		hash.Write(z)
+		hash.Write(s1)
+		k = append(k, hash.Sum(nil)...)
+		hash.Reset()
+		incCounter(counter)
+	}
+
+	k = k[:kdLen]
+	return
+}
+
+// messageTag computes the MAC of a message (called the tag) as per
+// SEC 1, 3.5.
+func messageTag(hash func() hash.Hash, km, msg, shared []byte) []byte {
+	mac := hmac.New(hash, km)
+	mac.Write(msg)
+	mac.Write(shared)
+	tag := mac.Sum(nil)
+	return tag
+}
+
+// Generate an initialisation vector for CTR mode.
+func generateIV(params *ECIESParams, rand io.Reader) (iv []byte, err error) {
+	iv = make([]byte, params.BlockSize)
+	_, err = io.ReadFull(rand, iv)
+	return
+}
+
+// symEncrypt carries out CTR encryption using the block cipher specified in the
+// parameters.
+func symEncrypt(rand io.Reader, params *ECIESParams, key, m []byte) (ct []byte, err error) {
+	c, err := params.Cipher(key)
+	if err != nil {
+		return
+	}
+
+	iv, err := generateIV(params, rand)
+	if err != nil {
+		return
+	}
+	ctr := cipher.NewCTR(c, iv)
+
+	ct = make([]byte, len(m)+params.BlockSize)
+	copy(ct, iv)
+	ctr.XORKeyStream(ct[params.BlockSize:], m)
+	return
+}
+
+// symDecrypt carries out CTR decryption using the block cipher specified in
+// the parameters
+func symDecrypt(params *ECIESParams, key, ct []byte) (m []byte, err error) {
+	c, err := params.Cipher(key)
+	if err != nil {
+		return
+	}
+
+	ctr := cipher.NewCTR(c, ct[:params.BlockSize])
+
+	m = make([]byte, len(ct)-params.BlockSize)
+	ctr.XORKeyStream(m, ct[params.BlockSize:])
+	return
+}
+
+// Encrypt encrypts a message using ECIES as specified in SEC 1, 5.1.
+//
+// s1 and s2 contain shared information that is not part of the resulting
+// ciphertext. s1 is fed into key derivation, s2 is fed into the MAC. If the
+// shared information parameters aren't being used, they should be nil.
+func Encrypt(rand io.Reader, pub *PublicKey, m, s1, s2 []byte) (ct []byte, err error) {
+	params := pub.Params
+	if params == nil {
+		if params = ParamsFromCurve(pub.Curve); params == nil {
+			err = ErrUnsupportedECIESParameters
+			return
+		}
+	}
+	R, err := GenerateKey(rand, pub.Curve, params)
+	if err != nil {
+		return
+	}
+
+	hash := params.Hash()
+	z, err := R.GenerateShared(pub, params.KeyLen, params.KeyLen)
+	if err != nil {
+		return
+	}
+	K, err := concatKDF(hash, z, s1, params.KeyLen+params.KeyLen)
+	if err != nil {
+		return
+	}
+	Ke := K[:params.KeyLen]
+	Km := K[params.KeyLen:]
+	hash.Write(Km)
+	Km = hash.Sum(nil)
+	hash.Reset()
+
+	em, err := symEncrypt(rand, params, Ke, m)
+	if err != nil || len(em) <= params.BlockSize {
+		return
+	}
+
+	d := messageTag(params.Hash, Km, em, s2)
+
+	Rb := elliptic.Marshal(pub.Curve, R.PublicKey.X, R.PublicKey.Y)
+	ct = make([]byte, len(Rb)+len(em)+len(d))
+	copy(ct, Rb)
+	copy(ct[len(Rb):], em)
+	copy(ct[len(Rb)+len(em):], d)
+	return
+}
+
+// Decrypt decrypts an ECIES ciphertext.
+func (prv *PrivateKey) Decrypt(c, s1, s2 []byte) (m []byte, err error) {
+	if len(c) == 0 {
+		return nil, ErrInvalidMessage
+	}
+	params := prv.PublicKey.Params
+	if params == nil {
+		if params = ParamsFromCurve(prv.PublicKey.Curve); params == nil {
+			err = ErrUnsupportedECIESParameters
+			return
+		}
+	}
+	hash := params.Hash()
+
+	var (
+		rLen   int
+		hLen   int = hash.Size()
+		mStart int
+		mEnd   int
+	)
+
+	switch c[0] {
+	case 2, 3, 4:
+		rLen = (prv.PublicKey.Curve.Params().BitSize + 7) / 4
+		if len(c) < (rLen + hLen + 1) {
+			err = ErrInvalidMessage
+			return
+		}
+	default:
+		err = ErrInvalidPublicKey
+		return
+	}
+
+	mStart = rLen
+	mEnd = len(c) - hLen
+
+	R := new(PublicKey)
+	R.Curve = prv.PublicKey.Curve
+	R.X, R.Y = elliptic.Unmarshal(R.Curve, c[:rLen])
+	if R.X == nil {
+		err = ErrInvalidPublicKey
+		return
+	}
+	if !R.Curve.IsOnCurve(R.X, R.Y) {
+		err = ErrInvalidCurve
+		return
+	}
+
+	z, err := prv.GenerateShared(R, params.KeyLen, params.KeyLen)
+	if err != nil {
+		return
+	}
+
+	K, err := concatKDF(hash, z, s1, params.KeyLen+params.KeyLen)
+	if err != nil {
+		return
+	}
+
+	Ke := K[:params.KeyLen]
+	Km := K[params.KeyLen:]
+	hash.Write(Km)
+	Km = hash.Sum(nil)
+	hash.Reset()
+
+	d := messageTag(params.Hash, Km, c[mStart:mEnd], s2)
+	if subtle.ConstantTimeCompare(c[mEnd:], d) != 1 {
+		err = ErrInvalidMessage
+		return
+	}
+
+	m, err = symDecrypt(params, Ke, c[mStart:mEnd])
+	return
+}
+
+
+//以下为从以太坊源码/crypt/ecies/params.go中截取过来
+func ParamsFromCurve(curve elliptic.Curve) (params *ECIESParams) {
+	return paramsFromCurve[curve]
+}
+var paramsFromCurve = map[elliptic.Curve]*ECIESParams{
+	//ethcrypto.S256(): ECIES_AES128_SHA256,
+	elliptic.P256():  ECIES_AES128_SHA256,
+	elliptic.P384():  ECIES_AES256_SHA384,
+	elliptic.P521():  ECIES_AES256_SHA512,
+}
+var (
+	ECIES_AES128_SHA256 = &ECIESParams{
+		Hash:      sha256.New,
+		hashAlgo:  crypto.SHA256,
+		Cipher:    aes.NewCipher,
+		BlockSize: aes.BlockSize,
+		KeyLen:    16,
+	}
+
+	ECIES_AES256_SHA256 = &ECIESParams{
+		Hash:      sha256.New,
+		hashAlgo:  crypto.SHA256,
+		Cipher:    aes.NewCipher,
+		BlockSize: aes.BlockSize,
+		KeyLen:    32,
+	}
+
+	ECIES_AES256_SHA384 = &ECIESParams{
+		Hash:      sha512.New384,
+		hashAlgo:  crypto.SHA384,
+		Cipher:    aes.NewCipher,
+		BlockSize: aes.BlockSize,
+		KeyLen:    32,
+	}
+
+	ECIES_AES256_SHA512 = &ECIESParams{
+		Hash:      sha512.New,
+		hashAlgo:  crypto.SHA512,
+		Cipher:    aes.NewCipher,
+		BlockSize: aes.BlockSize,
+		KeyLen:    32,
+	}
+)
+type ECIESParams struct {
+	Hash      func() hash.Hash // hash function
+	hashAlgo  crypto.Hash
+	Cipher    func([]byte) (cipher.Block, error) // symmetric cipher
+	BlockSize int                                // block size of symmetric cipher
+	KeyLen    int                                // length of symmetric key
+}