c#/JS RSA 非对称加密

可以用到 前端加密，后端解密，或者后端加解密

首先要知道这这个rsa是需要一个公钥一个私钥进行加解密的，公钥加密，私钥解密。可以去百度在线生成。

脚本或者页面中先引用jsencrypt.js

document.write("<script src= '../jsencrypt.js'></script>");

var publicKey="公钥";
//这个sign就是加密后的字符串
var sign = encryptRequest("123456", publicKey);

用jsencrypt类库加密js方法

function encryptRequest(str, publicKey) {
    var encrypt = new JSEncrypt();
    encrypt.setPublicKey(publicKey);
    // ajax请求发送的数据对象
    // 将data数组赋给ajax对象
    return encrypt.encrypt(str);

}

下面是c# 后端的加解密

public class RSAHelper
    {

        /// <summary>
        /// RSA加密
        /// </summary>
        /// <param name="publickey">公钥</param>
        /// <param name="content"></param>
        /// <returns></returns>
        public static string RSAEncrypt(string publickey, string content)
        {
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            byte[] cipherbytes;
            rsa.FromXmlString(publickey);
            cipherbytes = rsa.Encrypt(Encoding.UTF8.GetBytes(content), false);

            return Convert.ToBase64String(cipherbytes);
        }

        /// <summary>
        /// RSA解密
        /// </summary>
        /// <param name="privatekey">私钥</param>
        /// <param name="content"></param>
        /// <returns></returns>
        public static string RSADecrypt(string privatekey, string content)
        {
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
            byte[] cipherbytes;
            rsa.FromXmlString(privatekey);
            cipherbytes = rsa.Decrypt(Convert.FromBase64String(content), false);

            return Encoding.UTF8.GetString(cipherbytes);
        }


        /// <summary>  
        /// PEM格式私钥转换成XML格式私钥
        /// </summary>  
        /// <param name="privateKey">PEM格式私钥，（纯文字字符，注意不带-----BEGIN PRIVATE KEY-----和-----END PRIVATE KEY-----）</param>  
        /// <returns></returns>  
        public static string RSAPrivateKeyToXml(string privateKey)
        {
            RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey));

            return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>",
                Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()),
                Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned()));
        }

        /// <summary>    
        /// PEM格式公钥转换成XML格式公钥
        /// </summary>    
        /// <param name="publicKey">PEM格式公钥，（纯文字字符，注意不带-----BEGIN PUBLIC KEY-----和-----END PUBLIC KEY-----）</param>
        /// <returns>转换后的XML格式公钥</returns>    
        public static string RSAPublicKeyXML(string publicKey)
        {
            RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey));

            return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>",
                    Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
                    Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned()));
        }

    }

使用实例：

 var privateKey ="私钥"
 var RSAKey = RSAHelper.RSAPrivateKeyToXml(privateKey);//把私钥转换成xml格式
 var RSADecrypt = RSAHelper.RSADecrypt(RSAKey, Sign);//解密