github.com/sereiner/library@v0.0.0-20200518095232-1fa3e640cc5f/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  // Decrypt RSA解密
    39  // privateKey 解密时候用到的秘钥
    40  func Decrypt(ciphertext string, privateKey string) (string, error) {
    41  	block, _ := pem.Decode([]byte(privateKey))
    42  	if block == nil {
    43  		return "", errors.New("private key error")
    44  	}
    45  	priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    46  	if err != nil {
    47  		return "", fmt.Errorf("x509 ParsePKCS1PrivateKey err:%v", err)
    48  	}
    49  	input, err := base64.URLEncoding.DecodeString(ciphertext)
    50  	if err != nil {
    51  		return "", fmt.Errorf("base64 URLEncoding DecodeString err:%v", err)
    52  	}
    53  	data, err := rsa.DecryptPKCS1v15(rand.Reader, priv, input)
    54  	if err != nil {
    55  		return "", fmt.Errorf("rsa DecryptPKCS1v15 err:%v", err)
    56  	}
    57  
    58  	return string(data), nil
    59  	/*end*/
    60  }
    61  
    62  // Sign 使用RSA生成签名
    63  // 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]
    64  func Sign(message string, privateKey string, mode string) (string, error) {
    65  	block, _ := pem.Decode([]byte(privateKey))
    66  	if block == nil {
    67  		return "", errors.New("private key error")
    68  	}
    69  	priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
    70  	if err != nil {
    71  		return "", err
    72  	}
    73  
    74  	switch strings.ToLower(mode) {
    75  	case "sha256":
    76  		t := sha256.New()
    77  		io.WriteString(t, message)
    78  		digest := t.Sum(nil)
    79  		data, err := rsa.SignPKCS1v15(rand.Reader, priv, crypto.SHA256, digest)
    80  		if err != nil {
    81  			return "", err
    82  		}
    83  		return base64.StdEncoding.EncodeToString(data), nil
    84  	case "sha1":
    85  		t := sha1.New()
    86  		io.WriteString(t, message)
    87  		digest := t.Sum(nil)
    88  		data, err := rsa.SignPKCS1v15(rand.Reader, priv, crypto.SHA1, digest)
    89  		if err != nil {
    90  			return "", err
    91  		}
    92  		return base64.StdEncoding.EncodeToString(data), nil
    93  
    94  	case "md5":
    95  		t := md5.New()
    96  		io.WriteString(t, message)
    97  		digest := t.Sum(nil)
    98  		data, err := rsa.SignPKCS1v15(rand.Reader, priv, crypto.MD5, digest)
    99  		if err != nil {
   100  			return "", err
   101  		}
   102  		return base64.StdEncoding.EncodeToString(data), nil
   103  	default:
   104  		return "", errors.New("签名模式不支持")
   105  	}
   106  
   107  }
   108  
   109  // Verify 校验签名
   110  // 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]
   111  func Verify(src string, sign string, publicKey string, mode string) (pass bool, err error) {
   112  	//步骤1，加载RSA的公钥
   113  	block, _ := pem.Decode([]byte(publicKey))
   114  	pub, err := x509.ParsePKIXPublicKey(block.Bytes)
   115  	if err != nil {
   116  		return
   117  	}
   118  	rsaPub, _ := pub.(*rsa.PublicKey)
   119  	data, _ := base64.StdEncoding.DecodeString(sign)
   120  	switch strings.ToLower(mode) {
   121  	case "sha256":
   122  		t := sha256.New()
   123  		io.WriteString(t, src)
   124  		digest := t.Sum(nil)
   125  		err = rsa.VerifyPKCS1v15(rsaPub, crypto.SHA256, digest, data)
   126  	case "sha1":
   127  		t := sha1.New()
   128  		io.WriteString(t, src)
   129  		digest := t.Sum(nil)
   130  		err = rsa.VerifyPKCS1v15(rsaPub, crypto.SHA1, digest, data)
   131  	case "md5":
   132  		t := md5.New()
   133  		io.WriteString(t, src)
   134  		digest := t.Sum(nil)
   135  		err = rsa.VerifyPKCS1v15(rsaPub, crypto.MD5, digest, data)
   136  	default:
   137  		err = errors.New("验签模式不支持")
   138  	}
   139  	if err != nil {
   140  		return false, err
   141  	}
   142  	return true, nil
   143  }