github.com/qxnw/lib4go@v0.0.0-20180426074627-c80c7e84b925/security/rsa/rsa.go (about)

     1  package rsa
     2  
     3  import (
     4  	"crypto"
     5  	"crypto/md5"
     6  	"crypto/rand"
     7  	"crypto/rsa"
     8  	"crypto/sha1"
     9  	"crypto/sha256"
    10  	"crypto/x509"
    11  	"encoding/base64"
    12  	"encoding/pem"
    13  	"errors"
    14  	"fmt"
    15  	"io"
    16  	"strings"
    17  )
    18  
    19  // Encrypt RSA加密
    20  // publicKey 加密时候用到的公钥
    21  func Encrypt(origData string, publicKey string) (string, error) {
    22  	block, _ := pem.Decode([]byte(publicKey))
    23  	if block == nil {
    24  		return "", errors.New("public key error")
    25  	}
    26  	pubInterface, err := x509.ParsePKIXPublicKey(block.Bytes)
    27  	if err != nil {
    28  		return "", fmt.Errorf("x509 ParsePKIXPublicKey err:%v", err)
    29  	}
    30  	pub := pubInterface.(*rsa.PublicKey)
    31  	data, err := rsa.EncryptPKCS1v15(rand.Reader, pub, []byte(origData))
    32  	if err != nil {
    33  		return "", fmt.Errorf("rsa EncryptPKCS1v15 err:%v", err)
    34  	}
    35  	return base64.URLEncoding.EncodeToString(data), nil
    36  
    37  }
    38  
    39  // Decrypt RSA解密
    40  // privateKey 解密时候用到的秘钥
    41  func Decrypt(ciphertext string, privateKey string) (string, error) {
    42  	block, _ := pem.Decode([]byte(privateKey))
    43  	if block == nil {
    44  		return "", errors.New("private key error")
    45  	}
    46  	priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    47  	if err != nil {
    48  		return "", fmt.Errorf("x509 ParsePKCS1PrivateKey err:%v", err)
    49  	}
    50  	input, err := base64.URLEncoding.DecodeString(ciphertext)
    51  	if err != nil {
    52  		return "", fmt.Errorf("base64 URLEncoding DecodeString err:%v", err)
    53  	}
    54  	data, err := rsa.DecryptPKCS1v15(rand.Reader, priv, input)
    55  	if err != nil {
    56  		return "", fmt.Errorf("rsa DecryptPKCS1v15 err:%v", err)
    57  	}
    58  
    59  	return string(data), nil
    60  	/*end*/
    61  }
    62  
    63  // Sign 使用RSA生成签名
    64  // privateKey 加密时使用的秘钥	mode 加密的模式[目前只支持MD5，SHA1，不区分大小写]
    65  func Sign(message string, privateKey string, mode string) (string, error) {
    66  	block, _ := pem.Decode([]byte(privateKey))
    67  	if block == nil {
    68  		return "", errors.New("private key error")
    69  	}
    70  	priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    71  	if err != nil {
    72  		return "", err
    73  	}
    74  
    75  	switch strings.ToLower(mode) {
    76  	case "sha256":
    77  		t := sha256.New()
    78  		io.WriteString(t, message)
    79  		digest := t.Sum(nil)
    80  		data, err := rsa.SignPKCS1v15(rand.Reader, priv, crypto.SHA256, digest)
    81  		if err != nil {
    82  			return "", err
    83  		}
    84  		return base64.StdEncoding.EncodeToString(data), nil
    85  	case "sha1":
    86  		t := sha1.New()
    87  		io.WriteString(t, message)
    88  		digest := t.Sum(nil)
    89  		data, err := rsa.SignPKCS1v15(rand.Reader, priv, crypto.SHA1, digest)
    90  		if err != nil {
    91  			return "", err
    92  		}
    93  		return base64.StdEncoding.EncodeToString(data), nil
    94  
    95  	case "md5":
    96  		t := md5.New()
    97  		io.WriteString(t, message)
    98  		digest := t.Sum(nil)
    99  		data, err := rsa.SignPKCS1v15(rand.Reader, priv, crypto.MD5, digest)
   100  		if err != nil {
   101  			return "", err
   102  		}
   103  		return base64.StdEncoding.EncodeToString(data), nil
   104  	default:
   105  		return "", errors.New("签名模式不支持")
   106  	}
   107  
   108  }
   109  
   110  // Verify 校验签名
   111  // publicKey 验证签名的公钥	mode 加密的模式[目前只支持MD5，SHA1，不区分大小写]
   112  func Verify(src string, sign string, publicKey string, mode string) (pass bool, err error) {
   113  	//步骤1，加载RSA的公钥
   114  	block, _ := pem.Decode([]byte(publicKey))
   115  	pub, err := x509.ParsePKIXPublicKey(block.Bytes)
   116  	if err != nil {
   117  		return
   118  	}
   119  	rsaPub, _ := pub.(*rsa.PublicKey)
   120  	data, _ := base64.StdEncoding.DecodeString(sign)
   121  	switch strings.ToLower(mode) {
   122  	case "sha256":
   123  		t := sha256.New()
   124  		io.WriteString(t, src)
   125  		digest := t.Sum(nil)
   126  		err = rsa.VerifyPKCS1v15(rsaPub, crypto.SHA256, digest, data)
   127  	case "sha1":
   128  		t := sha1.New()
   129  		io.WriteString(t, src)
   130  		digest := t.Sum(nil)
   131  		err = rsa.VerifyPKCS1v15(rsaPub, crypto.SHA1, digest, data)
   132  	case "md5":
   133  		t := md5.New()
   134  		io.WriteString(t, src)
   135  		digest := t.Sum(nil)
   136  		err = rsa.VerifyPKCS1v15(rsaPub, crypto.MD5, digest, data)
   137  	default:
   138  		err = errors.New("验签模式不支持")
   139  	}
   140  	if err != nil {
   141  		return false, err
   142  	}
   143  	return true, nil
   144  }