IBM openblockchain学习(四)--crypto源码分析

crypto是blockchain中加密技术功能的实现，其中包括了椭圆曲线加密和SHA256等加密算法等，接下来将对其核心部分进行解析。

elliptic

返回加密层中使用的默认椭圆曲线

func GetDefaultCurve() elliptic.Curve {
return defaultCurve
}

hash

返回加密层中使用的默认哈希值

func GetDefaultHash() func() hash.Hash {
return defaultHash
}

init

在给定的安全级别内初始化密码层

func InitSecurityLevel(level int) (err error) {
initOnce.Do(func() {
switch level {
case 256:
defaultCurve = elliptic.P256()
defaultHash = sha3.New256
case 384:
defaultCurve = elliptic.P384()
defaultHash = sha3.New384
default:
err = fmt.Errorf("Security level not supported [%d]", level)
}
})

return
}

generic

generic位于ecies包下

engine

aesEncrypt

ase加密

func aesEncrypt(key, plain []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}

text := make([]byte, aes.BlockSize+len(plain))
iv := text[:aes.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
return nil, err
}

cfb := cipher.NewCFBEncrypter(block, iv)
cfb.XORKeyStream(text[aes.BlockSize:], plain)

return text, nil
}

aesDecrypt

aes解密

func aesDecrypt(key, text []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}

if len(text) < aes.BlockSize {
return nil, errors.New("cipher text too short")
}

cfb := cipher.NewCFBDecrypter(block, text[:aes.BlockSize])
plain := make([]byte, len(text)-aes.BlockSize)
cfb.XORKeyStream(plain, text[aes.BlockSize:])

return plain, nil
}

eciesGenerateKey

ECIES生成密钥

func eciesGenerateKey(rand io.Reader, curve elliptic.Curve, params *Params) (*ecdsa.PrivateKey, error) {
return ecdsa.GenerateKey(curve, rand)
}

eciesEncrypt

func eciesEncrypt(rand io.Reader, pub *ecdsa.PublicKey, s1, s2 []byte, plain []byte) ([]byte, error) {
params := pub.Curve.Params()

//选择带有椭圆曲线域参数相关的临时椭圆曲线密钥对
priv, Rx, Ry, err := elliptic.GenerateKey(pub.Curve, rand)
//fmt.Printf("Rx %s\n", utils.EncodeBase64(Rx.Bytes()))
//fmt.Printf("Ry %s\n", utils.EncodeBase64(Ry.Bytes()))

// 转换 R=(Rx,Ry) 为R字节串
// 这是未压缩的
Rb := elliptic.Marshal(pub.Curve, Rx, Ry)

// 从暂时的私钥k得出一个公钥元素z，并且将字节串z转化为Z
z, _ := params.ScalarMult(pub.X, pub.Y, priv)
Z := z.Bytes()
//fmt.Printf("Z %s\n", utils.EncodeBase64(Z))

//借助Z中生成长度为ecnKeyLen+macKeyLen的公钥数据K

// ans s1
kE := make([]byte, 32)
kM := make([]byte, 32)
hkdf := hkdf.New(conf.GetDefaultHash(), Z, s1, nil)
_, err = hkdf.Read(kE)
if err != nil {
return nil, err
}
_, err = hkdf.Read(kM)
if err != nil {
return nil, err
}

//使用对称加密方案的加密运算加密m在EK中的密文EM
EM, err := aesEncrypt(kE, plain)

//使用MAC方案的标签操作来计算EM上的标签D||S2
mac := hmac.New(conf.GetDefaultHash(), kM)
mac.Write(EM)
if len(s2) > 0 {
mac.Write(s2)
}
D := mac.Sum(nil)

// Output R,EM,D
ciphertext := make([]byte, len(Rb)+len(EM)+len(D))
//fmt.Printf("Rb %s\n", utils.EncodeBase64(Rb))
//fmt.Printf("EM %s\n", utils.EncodeBase64(EM))
//fmt.Printf("D %s\n", utils.EncodeBase64(D))
copy(ciphertext, Rb)
copy(ciphertext[len(Rb):], EM)
copy(ciphertext[len(Rb)+len(EM):], D)

return ciphertext, nil
}

eciesDecrypt

func eciesDecrypt(priv *ecdsa.PrivateKey, s1, s2 []byte, ciphertext []byte) ([]byte, error) {
params := priv.Curve.Params()

var (
rLen   int
hLen   int = conf.GetDefaultHash()().Size()
mStart int
mEnd   int
)

//fmt.Printf("Decrypt\n")
switch ciphertext[0] {
case 2, 3:
rLen = ((priv.PublicKey.Curve.Params().BitSize + 7) / 8) + 1
if len(ciphertext) < (rLen + hLen + 1) {
return nil, errors.New("Invalid ciphertext")
}
break
case 4:
rLen = 2*((priv.PublicKey.Curve.Params().BitSize+7)/8) + 1
if len(ciphertext) < (rLen + hLen + 1) {
return nil, errors.New("Invalid ciphertext")
}
break

default:
return nil, errors.New("Invalid ciphertext")
}

mStart = rLen
mEnd = len(ciphertext) - hLen
//fmt.Printf("Rb %s\n", utils.EncodeBase64(ciphertext[:rLen]))

Rx, Ry := elliptic.Unmarshal(priv.Curve, ciphertext[:rLen])
if Rx == nil {
return nil, errors.New("Invalid ephemeral PK")
}
if !priv.Curve.IsOnCurve(Rx, Ry) {
return nil, errors.New("Invalid point on curve")
}
//fmt.Printf("Rx %s\n", utils.EncodeBase64(Rx.Bytes()))
//fmt.Printf("Ry %s\n", utils.EncodeBase64(Ry.Bytes()))

// 从暂时的私钥k得出一个公钥z，并转换z到字节串Z
z, _ := params.ScalarMult(Rx, Ry, priv.D.Bytes())
Z := z.Bytes()
//fmt.Printf("Z %s\n", utils.EncodeBase64(Z))

kE := make([]byte, 32)
kM := make([]byte, 32)
hkdf := hkdf.New(conf.GetDefaultHash(), Z, s1, nil)
_, err := hkdf.Read(kE)
if err != nil {
return nil, err
}
_, err = hkdf.Read(kM)
if err != nil {
return nil, err
}

// 使用MAC方案的标签操作来计算EM上的标签,再对比D||S2
mac := hmac.New(conf.GetDefaultHash(), kM)
mac.Write(ciphertext[mStart:mEnd])
if len(s2) > 0 {
mac.Write(s2)
}
D := mac.Sum(nil)

//fmt.Printf("EM %s\n", utils.EncodeBase64(ciphertext[mStart:mEnd]))
//fmt.Printf("D' %s\n", utils.EncodeBase64(D))
//fmt.Printf("D %s\n", utils.EncodeBase64(ciphertext[mEnd:]))
if subtle.ConstantTimeCompare(ciphertext[mEnd:], D) != 1 {
return nil, errors.New("Tag check failed")
}

// 使用对称加密方案的解密操作使用明文EK解密EM

plaintext, err := aesDecrypt(kE, ciphertext[mStart:mEnd])

return plaintext, err
}

es

func (es *encryptionSchemeImpl) Init(params ecies.AsymmetricCipherParameters) error {
if params == nil {
return ecies.ErrInvalidKeyParameter
}
es.isForEncryption = params.IsPublic()
es.params = params

if es.isForEncryption {
switch pk := params.(type) {
case *publicKeyImpl:
es.pub = pk
default:
return ecies.ErrInvalidKeyParameter
}
} else {
switch sk := params.(type) {
case *secretKeyImpl:
es.priv = sk
default:
return ecies.ErrInvalidKeyParameter
}
}

return nil
}

func (es *encryptionSchemeImpl) Process(msg []byte) ([]byte, error) {
if es.isForEncryption {
// 加密
return eciesEncrypt(es.params.GetRand(), es.pub.pub, nil, nil, msg)
} else {
// 解密
return eciesDecrypt(es.priv.priv, nil, nil, msg)
}

return nil, nil
}

kg

生成密钥

func (kg *keyGeneratorImpl) GenerateKey() (ecies.PrivateKey, error) {

privKey, err := eciesGenerateKey(
kg.params.rand,
kg.params.curve,
kg.params.params,
)
if err != nil {
return nil, err
}

return &secretKeyImpl{privKey, nil, kg.params.params, kg.params.rand}, nil
}

params

type Params struct {
Hash      func() hash.Hash
hashAlgo  crypto.Hash //哈希加密
Cipher    func([]byte) (cipher.Block, error) //暗号
BlockSize int //块大小
KeyLen    int //密钥长度
}

pk

//获取随机密钥
func (pk *publicKeyImpl) GetRand() io.Reader {
return pk.rand
}
//判断是否为公钥
func (pk *publicKeyImpl) IsPublic() bool {
return true
}

sk

func (sk *secretKeyImpl) IsPublic() bool {
return false
}

func (sk *secretKeyImpl) GetRand() io.Reader {
return sk.rand
}

func (sk *secretKeyImpl) GetPublicKey() ecies.PublicKey {
if sk.pub == nil {
sk.pub = &publicKeyImpl{&sk.priv.PublicKey, sk.rand, sk.params}
}
return sk.pub
}
//转换为字节
func (sks *secretKeySerializerImpl) ToBytes(key interface{}) ([]byte, error) {
switch sk := key.(type) {
case *secretKeyImpl:
return x509.MarshalECPrivateKey(sk.priv)
default:
return nil, ecies.ErrInvalidKeyParameter
}

return nil, ecies.ErrInvalidKeyParameter
}
//从字节中转换私钥
func (sks *secretKeySerializerImpl) FromBytes(bytes []byte) (interface{}, error) {
key, err := x509.ParseECPrivateKey(bytes)
if err != nil {
return nil, err
}

// TODO: add params here
return &secretKeyImpl{key, nil, nil, rand.Reader}, nil
}

spi

//序列化私钥
func serializePrivateKey(priv ecies.PrivateKey) ([]byte, error) {
serializer := secretKeySerializerImpl{}
return serializer.ToBytes(priv)
}
//反序列化私钥
func deserializePrivateKey(bytes []byte) (ecies.PrivateKey, error) {
serializer := secretKeySerializerImpl{}
priv, err := serializer.FromBytes(bytes)
if err != nil {
return nil, err
}

return priv.(ecies.PrivateKey), nil
}
//生成非对称密码
func newAsymmetricCipher() (ecies.AsymmetricCipher, error) {
return &encryptionSchemeImpl{}, nil
}
//生成私钥
func newPrivateKey(rand io.Reader, curve elliptic.Curve) (ecies.PrivateKey, error) {
kg, err := newKeyGeneratorFromCurve(rand, curve)
if err != nil {
return nil, err
}
return kg.GenerateKey()
}
//从私钥创建非对称密码
func newAsymmetricCipherFromPrivateKey(priv ecies.PrivateKey) (ecies.AsymmetricCipher, error) {
es, err := newAsymmetricCipher()
if err != nil {
return nil, err
}

err = es.Init(priv)
if err != nil {
return nil, err
}

return es, nil
}
//从公钥创建非对称密码
func newAsymmetricCipherFromPublicKey(pub ecies.PublicKey) (ecies.AsymmetricCipher, error) {
es, err := newAsymmetricCipher()
if err != nil {
return nil, err
}

err = es.Init(pub)
if err != nil {
return nil, err
}

return es, nil
}

crypto

cypto实现了和密钥有关的接口

var (
// 无效的密钥参数
ErrInvalidKeyParameter = errors.New("Invalid Key Parameter.")

//无效的密钥生成器参数
ErrInvalidKeyGeneratorParameter = errors.New("Invalid Key Generator Parameter.")
)

// 对于所有参数的通用接口
type Parameters interface {

// 随机生成关联参数
GetRand() io.Reader
}

// 通用接口来表示密码参数
type CipherParameters interface {
Parameters
}

// 通用接口来表示非对称密码参数
type AsymmetricCipherParameters interface {
Parameters

// 如果参数是公开的返回true，否则为false。
IsPublic() bool
}

//通用接口代表非对称公钥参数
type PublicKey interface {
AsymmetricCipherParameters
}

//通用接口代表非对称私钥参数
type PrivateKey interface {
AsymmetricCipherParameters

// 返回关联公钥
GetPublicKey() PublicKey
}

// 通用接口来表示密钥生成参数
type KeyGeneratorParameters interface {
Parameters
}

// 定义密钥生成器
type KeyGenerator interface {
//初始化生成使用传递的参数
Init(params KeyGeneratorParameters) error

// 生成一个新的私钥
GenerateKey() (PrivateKey, error)
}

//定义了一个非对称密码
type AsymmetricCipher interface {
// 使用传递的参数初始化
Init(params AsymmetricCipherParameters) error

// 处理输入给出的字节数组的过程
Process(msg []byte) ([]byte, error)
}

// 密钥序列化/反序列化
type KeySerializer interface {
// 转换密钥为字节
ToBytes(key interface{}) ([]byte, error)

// 转换字节为密钥
FromBytes([]byte) (interface{}, error)
}

// ECIES服务提供接口
type SPI interface {

//从秘钥创建解密一个新的非对称密码
NewAsymmetricCipherFromPrivateKey(priv PrivateKey) (AsymmetricCipher, error)

//从公钥创建解密一个新的非对称密码
NewAsymmetricCipherFromPublicKey(pub PublicKey) (AsymmetricCipher, error)

// 从(rand, params)创建一个新的私钥
NewPrivateKey(rand io.Reader, params interface{}) (PrivateKey, error)

//从(rand, params)创建一个新的公钥
NewPublicKey(rand io.Reader, params interface{}) (PublicKey, error)

// 序列化私钥
SerializePrivateKey(priv PrivateKey) ([]byte, error)

// 反序列化私钥
DeserializePrivateKey(bytes []byte) (PrivateKey, error)
}

aes

const (
// AES 秘钥的默认长度
AESKeyLength = 32

// 默认nonce大小
NonceSize    = 24
)

// 返回一个长度AESKeyLength为随机 AES 密钥
func GenAESKey() ([]byte, error) {
return GetRandomBytes(AESKeyLength)
}

//基于PKCS7标准填充
func PKCS7Padding(src []byte) []byte {
padding := aes.BlockSize - len(src)%aes.BlockSize
padtext := bytes.Repeat([]byte{byte(padding)}, padding)
return append(src, padtext...)
}

//基于PKCS7标准反填充
func PKCS7UnPadding(src []byte) ([]byte, error) {
length := len(src)
unpadding := int(src[length-1])

if unpadding > aes.BlockSize || unpadding == 0 {
return nil, fmt.Errorf("invalid padding")
}

pad := src[len(src)-unpadding:]
for i := 0; i < unpadding; i++ {
if pad[i] != byte(unpadding) {
return nil, fmt.Errorf("invalid padding")
}
}

return src[:(length - unpadding)], nil
}

//使用CBC模式加密
func CBCEncrypt(key, s []byte) ([]byte, error) {
// CBC模式适用于块，这样的明文可能需要填充到下一个整块。对于这种填充的一个实例，参见
// https://tools.ietf.org/html/rfc5246#section-6.2.3.2. Here we'll
// 假定所述明文已确定长度。
if len(s)%aes.BlockSize != 0 {
return nil, errors.New("plaintext is not a multiple of the block size")
}

block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}

// 需要唯一，但并不安全。因此它是常见的包括其在密文的开始。
ciphertext := make([]byte, aes.BlockSize+len(s))
iv := ciphertext[:aes.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
return nil, err
}

mode := cipher.NewCBCEncrypter(block, iv)
mode.CryptBlocks(ciphertext[aes.BlockSize:], s)

// 要记住，密文必须经过验证是非常重要的（即，通过使用加密/ HMAC）以及为了被加密是安全的。
return ciphertext, nil
}

// 使用CBC模式解密
func CBCDecrypt(key, src []byte) ([]byte, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}

// 需要唯一，但并不安全。因此它是常见的包括其在密文的开始。
if len(src) < aes.BlockSize {
return nil, errors.New("ciphertext too short")
}
iv := src[:aes.BlockSize]
src = src[aes.BlockSize:]

//CBC模式往往工作于整个块中
if len(src)%aes.BlockSize != 0 {
return nil, errors.New("ciphertext is not a multiple of the block size")
}

mode := cipher.NewCBCDecrypter(block, iv)

//可以就地工作，如果两个参数是相同的。
mode.CryptBlocks(src, src)

// 如果原来的明文的长度不是块大小的倍数，加密填充时，这将在这一点被移除被添加

return src, nil
}

// 结合CBC加密填充PKCS7
func CBCPKCS7Encrypt(key, src []byte) ([]byte, error) {
return CBCEncrypt(key, PKCS7Padding(src))
}

//结合CBC加密反填充填充PKCS7
func CBCPKCS7Decrypt(key, src []byte) ([]byte, error) {
pt, err := CBCDecrypt(key, src)
if err != nil {
return nil, err
}

original, err := PKCS7UnPadding(pt)
if err != nil {
return nil, err
}

return original, nil
}

cert

var (
// TCertEncTCertIndex为TCertIndex的对象标识符
TCertEncTCertIndex = asn1.ObjectIdentifier{1, 2, 3, 4, 5, 6, 7}
)

// 将der转换为X509
func DERToX509Certificate(asn1Data []byte) (*x509.Certificate, error) {
return x509.ParseCertificate(asn1Data)
}

//  将pem转换为X509
func PEMtoCertificate(raw []byte) (*x509.Certificate, error) {
block, _ := pem.Decode(raw)
if block == nil {
return nil, errors.New("No PEM block available")
}

if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
return nil, errors.New("Not a valid CERTIFICATE PEM block")
}

cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return nil, err
}

return cert, nil
}

// 将 pem 转换为der
func PEMtoDER(raw []byte) ([]byte, error) {
block, _ := pem.Decode(raw)
if block == nil {
return nil, errors.New("No PEM block available")
}

if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
return nil, errors.New("Not a valid CERTIFICATE PEM block")
}

return block.Bytes, nil
}

// 将 pem 转换为x509和der
func PEMtoCertificateAndDER(raw []byte) (*x509.Certificate, []byte, error) {
block, _ := pem.Decode(raw)
if block == nil {
return nil, nil, errors.New("No PEM block available")
}

if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
return nil, nil, errors.New("Not a valid CERTIFICATE PEM block")
}

cert, err := x509.ParseCertificate(block.Bytes)
if err != nil {
return nil, nil, err
}

return cert, block.Bytes, nil
}

// 将der转换为pem
func DERCertToPEM(der []byte) []byte {
return pem.EncodeToMemory(
&pem.Block{
Type:  "CERTIFICATE",
Bytes: der,
},
)
}

// 返回请求的关键扩展。这也从未处理的关键扩展的列表中移除
func GetCriticalExtension(cert *x509.Certificate, oid asn1.ObjectIdentifier) ([]byte, error) {
for i, ext := range cert.UnhandledCriticalExtensions {
if IntArrayEquals(ext, oid) {
cert.UnhandledCriticalExtensions = append(cert.UnhandledCriticalExtensions[:i], cert.UnhandledCriticalExtensions[i+1:]...)

break
}
}

for _, ext := range cert.Extensions {
if IntArrayEquals(ext.Id, oid) {
return ext.Value, nil
}
}

return nil, errors.New("Failed retrieving extension.")
}

// 创建一个自签名证书
func NewSelfSignedCert() ([]byte, interface{}, error) {
privKey, err := NewECDSAKey()
if err != nil {
return nil, nil, err
}

testExtKeyUsage := []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth}
testUnknownExtKeyUsage := []asn1.ObjectIdentifier{[]int{1, 2, 3}, []int{2, 59, 1}}
extraExtensionData := []byte("extra extension")
commonName := "test.example.com"
template := x509.Certificate{
SerialNumber: big.NewInt(1),
Subject: pkix.Name{
CommonName:   commonName,
Organization: []string{"Σ Acme Co"},
Country:      []string{"US"},
ExtraNames: []pkix.AttributeTypeAndValue{
{
Type:  []int{2, 5, 4, 42},
Value: "Gopher",
},
// 应该全部覆盖Country.
{
Type:  []int{2, 5, 4, 6},
Value: "NL",
},
},
},
NotBefore: time.Unix(1000, 0),
NotAfter:  time.Unix(100000, 0),

SignatureAlgorithm: x509.ECDSAWithSHA384,

SubjectKeyId: []byte{1, 2, 3, 4},
KeyUsage:     x509.KeyUsageCertSign,

ExtKeyUsage:        testExtKeyUsage,
UnknownExtKeyUsage: testUnknownExtKeyUsage,

BasicConstraintsValid: true,
IsCA: true,

OCSPServer:            []string{"http://ocsp.example.com"},
IssuingCertificateURL: []string{"http://crt.example.com/ca1.crt"},

DNSNames:       []string{"test.example.com"},
EmailAddresses: []string{"gopher@golang.org"},
IPAddresses:    []net.IP{net.IPv4(127, 0, 0, 1).To4(), net.ParseIP("2001:4860:0:2001::68")},

PolicyIdentifiers:   []asn1.ObjectIdentifier{[]int{1, 2, 3}},
PermittedDNSDomains: []string{".example.com", "example.com"},

CRLDistributionPoints: []string{"http://crl1.example.com/ca1.crl", "http://crl2.example.com/ca1.crl"},

ExtraExtensions: []pkix.Extension{
{
Id:    []int{1, 2, 3, 4},
Value: extraExtensionData,
},
},
}

cert, err := x509.CreateCertificate(rand.Reader, &template, &template, &privKey.PublicKey, privKey)
if err != nil {
return nil, nil, err
}

return cert, privKey, nil
}

//通过密钥检查证书的公钥
func CheckCertPKAgainstSK(x509Cert *x509.Certificate, privateKey interface{}) error {
switch pub := x509Cert.PublicKey.(type) {
case *rsa.PublicKey:
priv, ok := privateKey.(*rsa.PrivateKey)
if !ok {
return errors.New("Private key type does not match public key type")
}
if pub.N.Cmp(priv.N) != 0 {
return errors.New("Private key does not match public key")
}
case *ecdsa.PublicKey:
priv, ok := privateKey.(*ecdsa.PrivateKey)
if !ok {
return errors.New("Private key type does not match public key type")

}
if pub.X.Cmp(priv.X) != 0 || pub.Y.Cmp(priv.Y) != 0 {
return errors.New("Private key does not match public key")
}
default:
return errors.New("Unknown public key algorithm")
}

return nil
}

// 检查证书的有效性通过certPool
func CheckCertAgainRoot(x509Cert *x509.Certificate, certPool *x509.CertPool) ([][]*x509.Certificate, error) {
opts := x509.VerifyOptions{
// TODO     DNSName: "test.example.com",
Roots: certPool,
}

return x509Cert.Verify(opts)
}

// 对检查合格的密钥和CertPool传递证书
func CheckCertAgainstSKAndRoot(x509Cert *x509.Certificate, privateKey interface{}, certPool *x509.CertPool) error {
if err := CheckCertPKAgainstSK(x509Cert, privateKey); err != nil {
return err
}

if _, err := CheckCertAgainRoot(x509Cert, certPool); err != nil {
return err
}

return nil
}

conf

// 返回注册ID
func (conf *NodeConfiguration) GetEnrollmentID() string {
key := "tests.crypto.users." + conf.Name + ".enrollid"
value := viper.GetString(key)
if value == "" {
panic(fmt.Errorf("Enrollment id not specified in configuration file. Please check that property '%s' is set", key))
}
return value
}

//返回注册密码
func (conf *NodeConfiguration) GetEnrollmentPWD() string {
key := "tests.crypto.users." + conf.Name + ".enrollpw"
value := viper.GetString(key)
if value == "" {
panic(fmt.Errorf("Enrollment id not specified in configuration file. Please check that property '%s' is set", key))
}
return value
}

ecdsa

// 表示ECDSA签名
type ECDSASignature struct {
R, S *big.Int
}

//生成一个新的ECDSA密钥
func NewECDSAKey() (*ecdsa.PrivateKey, error) {
return ecdsa.GenerateKey(conf.GetDefaultCurve(), rand.Reader)
}

// ECDSASignDirect 符号
func ECDSASignDirect(signKey interface{}, msg []byte) (*big.Int, *big.Int, error) {
temp := signKey.(*ecdsa.PrivateKey)
h := Hash(msg)
r, s, err := ecdsa.Sign(rand.Reader, temp, h)
if err != nil {
return nil, nil, err
}

return r, s, nil
}

// ECDSASign 符号
func ECDSASign(signKey interface{}, msg []byte) ([]byte, error) {
temp := signKey.(*ecdsa.PrivateKey)
h := Hash(msg)
r, s, err := ecdsa.Sign(rand.Reader, temp, h)
if err != nil {
return nil, err
}

//  R, _ := r.MarshalText()
//  S, _ := s.MarshalText()
//
//  fmt.Printf("r [%s], s [%s]\n", R, S)

raw, err := asn1.Marshal(ECDSASignature{r, s})
if err != nil {
return nil, err
}

return raw, nil
}

//校验
func ECDSAVerify(verKey interface{}, msg, signature []byte) (bool, error) {
ecdsaSignature := new(ECDSASignature)
_, err := asn1.Unmarshal(signature, ecdsaSignature)
if err != nil {
return false, nil
}

//  R, _ := ecdsaSignature.R.MarshalText()
//  S, _ := ecdsaSignature.S.MarshalText()
//  fmt.Printf("r [%s], s [%s]\n", R, S)

temp := verKey.(*ecdsa.PublicKey)
h := Hash(msg)
return ecdsa.Verify(temp, h, ecdsaSignature.R, ecdsaSignature.S), nil
}

// 测试签名功能
func VerifySignCapability(tempSK interface{}, certPK interface{}) error {
/* TODO: reactive or remove
msg := []byte("This is a message to be signed and verified by ECDSA!")

sigma, err := ECDSASign(tempSK, msg)
if err != nil {
//      log.Error("Error signing [%s].", err.Error())

return err
}

ok, err := ECDSAVerify(certPK, msg, sigma)
if err != nil {
//      log.Error("Error verifying [%s].", err.Error())

return err
}

if !ok {
//      log.Error("Signature not valid.")

return errors.New("Signature not valid.")
}

//  log.Info("Verifing signature capability...done")
*/
return nil
}

hash

// 返回一个新的散列函数
func NewHash() hash.Hash {
return conf.GetDefaultHash()()
}

// 散列使用预定义散列函数的MSH
func Hash(msg []byte) []byte {
hash := NewHash()
hash.Write(msg)
return hash.Sum(nil)
}

// hmacs x 使用密钥的密钥
func HMAC(key, x []byte) []byte {
mac := hmac.New(conf.GetDefaultHash(), key)
mac.Write(x)

return mac.Sum(nil)
}

// hmacs x 使用密钥的密钥，并截断
func HMACTruncated(key, x []byte, truncation int) []byte {
mac := hmac.New(conf.GetDefaultHash(), key)
mac.Write(x)

return mac.Sum(nil)[:truncation]
}

io

// 检查一个目录是否丢失或为空
func DirMissingOrEmpty(path string) (bool, error) {
dirExists, err := DirExists(path)
if err != nil {
return false, err
}
if !dirExists {
return true, nil
}

dirEmpty, err := DirEmpty(path)
if err != nil {
return false, err
}
if dirEmpty {
return true, nil
}
return false, nil
}

// 检查一个目录是否存在
func DirExists(path string) (bool, error) {
_, err := os.Stat(path)
if err == nil {
return true, nil
}
if os.IsNotExist(err) {
return false, nil
}
return false, err
}

// 检查一个目录是否为空
func DirEmpty(path string) (bool, error) {
f, err := os.Open(path)
if err != nil {
return false, err
}
defer f.Close()

_, err = f.Readdir(1)
if err == io.EOF {
return true, nil
}
return false, err
}

// 检查一个文件是否丢失
func FileMissing(path string, name string) (bool, error) {
_, err := os.Stat(filepath.Join(path, name))
if err != nil {
return true, err
}
return false, nil
}

// 如果路径丢失返回true，否则返回false
func FilePathMissing(path string) (bool, error) {
_, err := os.Stat(path)
if err != nil {
return true, err
}
return false, nil
}

// Base64解码
func DecodeBase64(in string) ([]byte, error) {
return base64.StdEncoding.DecodeString(in)
}

// Base64编码
func EncodeBase64(in []byte) string {
return base64.StdEncoding.EncodeToString(in)
}

//检查整数的阵列是否相同
func IntArrayEquals(a []int, b []int) bool {
if len(a) != len(b) {
return false
}
for i, v := range a {
if v != b[i] {
return false
}
}
return true
}

// 检查 tcp端口是否打开
func IsTCPPortOpen(laddr string) error {
lis, err := net.Listen("tcp", laddr)
if err != nil {
return err
}
lis.Close()
return nil
}

var seed uint32
var randmu sync.Mutex

func reseed() uint32 {
return uint32(time.Now().UnixNano() + int64(os.Getpid()))
}

func nextSuffix() string {
randmu.Lock()
r := seed
if r == 0 {
r = reseed()
}
r = r*1664525 + 1013904223 // constants from Numerical Recipes
seed = r
randmu.Unlock()
return strconv.Itoa(int(1e9 + r%1e9))[1:]
}

// 返回一个临时文件的路径与关于系统的临时目录.
func TempFile(dir, prefix string) (name string, err error) {
if dir == "" {
dir = os.TempDir()
}

nconflict := 0
for i := 0; i < 10000; i++ {
name = filepath.Join(dir, prefix+nextSuffix())
f, err := os.Stat(name)
if f != nil || os.IsExist(err) {
if nconflict++; nconflict > 10 {
randmu.Lock()
seed = reseed()
randmu.Unlock()
}
continue
}
break
}
return
}

math

// 返回x的绝对值
func Abs(x int) int {
if x < 0 {
return -x
}
return x
}

random

返回随机寻找的字节的长度

func GetRandomBytes(len int) ([]byte, error) {
key := make([]byte, len)

_, err := rand.Read(key)
if err != nil {
return nil, err
}

return key, nil
}

slice

// 通过切片克隆
func Clone(src []byte) []byte {
clone := make([]byte, len(src))
copy(clone, src)

return clone
}

keys

// 为der反串行化为私钥
func PrivateKeyToDER(privateKey *ecdsa.PrivateKey) ([]byte, error) {
return x509.MarshalECPrivateKey(privateKey)
}

// 将私钥转换为PEM
func PrivateKeyToPEM(privateKey interface{}, pwd []byte) ([]byte, error) {
if len(pwd) != 0 {
return PrivateKeyToEncryptedPEM(privateKey, pwd)
}

switch x := privateKey.(type) {
case *ecdsa.PrivateKey:
raw, err := x509.MarshalECPrivateKey(x)

if err != nil {
return nil, err
}

return pem.EncodeToMemory(
&pem.Block{
Type:  "ECDSA PRIVATE KEY",
Bytes: raw,
},
), nil
default:
return nil, ErrInvalidKey
}
}

// 将私钥转换为加密PEM
func PrivateKeyToEncryptedPEM(privateKey interface{}, pwd []byte) ([]byte, error) {
switch x := privateKey.(type) {
case *ecdsa.PrivateKey:
raw, err := x509.MarshalECPrivateKey(x)

if err != nil {
return nil, err
}

block, err := x509.EncryptPEMBlock(
rand.Reader,
"ECDSA PRIVATE KEY",
raw,
pwd,
x509.PEMCipherAES256)

if err != nil {
return nil, err
}

return pem.EncodeToMemory(block), nil

default:
return nil, ErrInvalidKey
}
}

// 将der串行化为私钥
func DERToPrivateKey(der []byte) (key interface{}, err error) {
//fmt.Printf("DER [%s]\n", EncodeBase64(der))

if key, err = x509.ParsePKCS1PrivateKey(der); err == nil {
return key, nil
}
//fmt.Printf("DERToPrivateKey Err [%s]\n", err)
if key, err = x509.ParsePKCS8PrivateKey(der); err == nil {
switch key.(type) {
case *rsa.PrivateKey, *ecdsa.PrivateKey:
return
default:
return nil, errors.New("Found unknown private key type in PKCS#8 wrapping")
}
}
//fmt.Printf("DERToPrivateKey Err [%s]\n", err)
if key, err = x509.ParseECPrivateKey(der); err == nil {
return
}
//fmt.Printf("DERToPrivateKey Err [%s]\n", err)

return nil, errors.New("Failed to parse private key")
}

// 将pem串行化为私钥
func PEMtoPrivateKey(raw []byte, pwd []byte) (interface{}, error) {
block, _ := pem.Decode(raw)

// 从头部导出密钥的类型

if x509.IsEncryptedPEMBlock(block) {
if pwd == nil {
return nil, errors.New("Encrypted Key. Need a password!!!")
}

decrypted, err := x509.DecryptPEMBlock(block, pwd)
if err != nil {
return nil, errors.New("Failed decryption!!!")
}

key, err := DERToPrivateKey(decrypted)
if err != nil {
return nil, err
}
return key, err
}

cert, err := DERToPrivateKey(block.Bytes)
if err != nil {
return nil, err
}
return cert, err
}

// 从PEM提取一个AES密钥
func PEMtoAES(raw []byte, pwd []byte) ([]byte, error) {
block, _ := pem.Decode(raw)

if x509.IsEncryptedPEMBlock(block) {
if pwd == nil {
return nil, errors.New("Encrypted Key. Need a password!!!")
}

decrypted, err := x509.DecryptPEMBlock(block, pwd)
if err != nil {
return nil, err
}
return decrypted, nil
}

return block.Bytes, nil
}

// 将AES封装为PEM格式
func AEStoPEM(raw []byte) []byte {
return pem.EncodeToMemory(&pem.Block{Type: "AES PRIVATE KEY", Bytes: raw})
}

//将AES封装为加密PEM格式
func AEStoEncryptedPEM(raw []byte, pwd []byte) ([]byte, error) {
if len(pwd) == 0 {
return AEStoPEM(raw), nil
}

block, err := x509.EncryptPEMBlock(
rand.Reader,
"AES PRIVATE KEY",
raw,
pwd,
x509.PEMCipherAES256)

if err != nil {
return nil, err
}

return pem.EncodeToMemory(block), nil
}

// 将公钥反串行化为pem格式
func PublicKeyToPEM(publicKey interface{}, pwd []byte) ([]byte, error) {
if len(pwd) != 0 {
return PublicKeyToEncryptedPEM(publicKey, pwd)
}

switch x := publicKey.(type) {
case *ecdsa.PublicKey:
PubASN1, err := x509.MarshalPKIXPublicKey(x)
if err != nil {
return nil, err
}

return pem.EncodeToMemory(
&pem.Block{
Type:  "ECDSA PUBLIC KEY",
Bytes: PubASN1,
},
), nil

default:
return nil, ErrInvalidKey
}
}

// 将公钥转换为加密pem
func PublicKeyToEncryptedPEM(publicKey interface{}, pwd []byte) ([]byte, error) {
switch x := publicKey.(type) {
case *ecdsa.PublicKey:
raw, err := x509.MarshalPKIXPublicKey(x)

if err != nil {
return nil, err
}

block, err := x509.EncryptPEMBlock(
rand.Reader,
"ECDSA PUBLIC KEY",
raw,
pwd,
x509.PEMCipherAES256)

if err != nil {
return nil, err
}

return pem.EncodeToMemory(block), nil

default:
return nil, ErrInvalidKey
}
}

// 将pem串行化为公钥
func PEMtoPublicKey(raw []byte, pwd []byte) (interface{}, error) {
block, _ := pem.Decode(raw)
fmt.Printf("block % x\n", raw)

if x509.IsEncryptedPEMBlock(block) {
if pwd == nil {
return nil, errors.New("Encrypted Key. Need a password!!!")
}

decrypted, err := x509.DecryptPEMBlock(block, pwd)
if err != nil {
return nil, errors.New("Failed decryption!!!")
}

key, err := DERToPublicKey(decrypted)
if err != nil {
return nil, err
}
return key, err
}

cert, err := DERToPublicKey(block.Bytes)
if err != nil {
return nil, err
}
return cert, err
}

//将der串行化为公钥
func DERToPublicKey(derBytes []byte) (pub interface{}, err error) {
key, err := x509.ParsePKIXPublicKey(derBytes)

return key, err
}