1、进入微信公众号后台设置微信服务器配置参数（注意：Token和EncodingAESKey必须和微信服务器验证参数保持一致，不然验证不会通过）。
2、设置为安全模式
3、代码实现（主要分为验证接口和消息处理接口）：
/// <summary>
/// 验证接口
/// </summary>
/// <param name="signature">签名</param>
/// <param name="timestamp">时间戳</param>
/// <param name="nonce"></param>
/// <param name="echostr"></param>
/// <returns></returns>
[HttpGet, Route("Message")]
[AllowAnonymous]
public ActionResult MessageGet(string signature, string timestamp, string nonce, string echostr)
{
if (new SecurityHelper().CheckSignature(signature, timestamp, nonce, _settings.Value.Token))
{
return Content(echostr);
}
return Content("");
} /// <summary>
/// 接收消息并处理和返回相应结果
/// </summary>
/// <param name="msg_signature">当加密模式时才会有该变量（消息签名）</param>
/// <param name="signature">签名</param>
/// <param name="timestamp">时间戳</param>
/// <param name="nonce"></param>
/// <returns></returns>
[HttpPost, Route("Message")]
[AllowAnonymous]
public ActionResult MessagePost(string msg_signature, string signature, string timestamp, string nonce)
{
try
{
if (!new SecurityHelper().CheckSignature(signature, timestamp, nonce, _settings.Value.Token))
{
return Content(null);
}
using (Stream stream = HttpContext.Request.Body)
{
byte[] buffer = new byte[HttpContext.Request.ContentLength.Value];
stream.Read(buffer, , buffer.Length);
string content = Encoding.UTF8.GetString(buffer);
if (!string.IsNullOrWhiteSpace(msg_signature)) // 消息加密模式
{
string decryptMsg = string.Empty;
var wxBizMsgCrypt = new WXBizMsgCrypt(_settings.Value.Token, _settings.Value.EncodingAESKey, _settings.Value.AppId);
int decryptResult = wxBizMsgCrypt.DecryptMsg(msg_signature, timestamp, nonce, content, ref decryptMsg);
if (decryptResult == && !string.IsNullOrWhiteSpace(decryptMsg))
{
string resultMsg = new WechatMessageHelper().MessageResult(decryptMsg);
string sEncryptMsg = string.Empty;
if (!string.IsNullOrWhiteSpace(resultMsg))
{
int encryptResult = wxBizMsgCrypt.EncryptMsg(resultMsg, timestamp, nonce, ref sEncryptMsg);
if (encryptResult == && !string.IsNullOrWhiteSpace(sEncryptMsg))
{
return Content(sEncryptMsg);
}
}
}
}
else // 消息未加密码处理
{
string resultMsg = new WechatMessageHelper().MessageResult(content);
return Content(resultMsg);
}
return Content(null);
}
}
catch (Exception ex)
{
_logger.LogError("接收消息并处理和返回相应结果异常：", ex);
return Content(null);
}
}
加解密实现（微信公众号官网有源码）
using System;
using System.Collections;
using System.Security.Cryptography;
using System.Text;
using System.Xml; //-40001 ： 签名验证错误
//-40002 : xml解析失败
//-40003 : sha加密生成签名失败
//-40004 : AESKey 非法
//-40005 : appid 校验错误
//-40006 : AES 加密失败
//-40007 ： AES 解密失败
//-40008 ： 解密后得到的buffer非法
//-40009 : base64加密异常
//-40010 : base64解密异常
namespace Core.Common.Wechat
{
public class WXBizMsgCrypt
{
string m_sToken;
string m_sEncodingAESKey;
string m_sAppID;
enum WXBizMsgCryptErrorCode
{
WXBizMsgCrypt_OK = ,
WXBizMsgCrypt_ValidateSignature_Error = -,
WXBizMsgCrypt_ParseXml_Error = -,
WXBizMsgCrypt_ComputeSignature_Error = -,
WXBizMsgCrypt_IllegalAesKey = -,
WXBizMsgCrypt_ValidateAppid_Error = -,
WXBizMsgCrypt_EncryptAES_Error = -,
WXBizMsgCrypt_DecryptAES_Error = -,
WXBizMsgCrypt_IllegalBuffer = -,
WXBizMsgCrypt_EncodeBase64_Error = -,
WXBizMsgCrypt_DecodeBase64_Error = -
}; //构造函数
// @param sToken: 公众平台上，开发者设置的Token
// @param sEncodingAESKey: 公众平台上，开发者设置的EncodingAESKey
// @param sAppID: 公众帐号的appid
public WXBizMsgCrypt(string sToken, string sEncodingAESKey, string sAppID)
{
m_sToken = sToken;
m_sAppID = sAppID;
m_sEncodingAESKey = sEncodingAESKey;
} // 检验消息的真实性，并且获取解密后的明文
// @param sMsgSignature: 签名串，对应URL参数的msg_signature
// @param sTimeStamp: 时间戳，对应URL参数的timestamp
// @param sNonce: 随机串，对应URL参数的nonce
// @param sPostData: 密文，对应POST请求的数据
// @param sMsg: 解密后的原文，当return返回0时有效
// @return: 成功0，失败返回对应的错误码
public int DecryptMsg(string sMsgSignature, string sTimeStamp, string sNonce, string sPostData, ref string sMsg)
{
if (m_sEncodingAESKey.Length != )
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
}
XmlDocument doc = new XmlDocument();
XmlNode root;
string sEncryptMsg;
try
{
doc.LoadXml(sPostData);
root = doc.FirstChild;
sEncryptMsg = root["Encrypt"].InnerText;
}
catch (Exception)
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ParseXml_Error;
}
//verify signature
int ret = ;
ret = VerifySignature(m_sToken, sTimeStamp, sNonce, sEncryptMsg, sMsgSignature);
if (ret != )
return ret;
//decrypt
string cpid = "";
try
{
sMsg = Cryptography.AES_decrypt(sEncryptMsg, m_sEncodingAESKey, ref cpid);
}
catch (FormatException)
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_DecodeBase64_Error;
}
catch (Exception)
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_DecryptAES_Error;
}
if (cpid != m_sAppID)
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ValidateAppid_Error;
return ;
} //将企业号回复用户的消息加密打包
// @param sReplyMsg: 企业号待回复用户的消息，xml格式的字符串
// @param sTimeStamp: 时间戳，可以自己生成，也可以用URL参数的timestamp
// @param sNonce: 随机串，可以自己生成，也可以用URL参数的nonce
// @param sEncryptMsg: 加密后的可以直接回复用户的密文，包括msg_signature, timestamp, nonce, encrypt的xml格式的字符串,
// 当return返回0时有效
// return：成功0，失败返回对应的错误码
public int EncryptMsg(string sReplyMsg, string sTimeStamp, string sNonce, ref string sEncryptMsg)
{
if (m_sEncodingAESKey.Length != )
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
}
string raw = "";
try
{
raw = Cryptography.AES_encrypt(sReplyMsg, m_sEncodingAESKey, m_sAppID);
}
catch (Exception)
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_EncryptAES_Error;
}
string MsgSigature = "";
int ret = ;
ret = GenarateSinature(m_sToken, sTimeStamp, sNonce, raw, ref MsgSigature);
if ( != ret)
return ret;
sEncryptMsg = ""; string EncryptLabelHead = "<Encrypt><![CDATA[";
string EncryptLabelTail = "]]></Encrypt>";
string MsgSigLabelHead = "<MsgSignature><![CDATA[";
string MsgSigLabelTail = "]]></MsgSignature>";
string TimeStampLabelHead = "<TimeStamp><![CDATA[";
string TimeStampLabelTail = "]]></TimeStamp>";
string NonceLabelHead = "<Nonce><![CDATA[";
string NonceLabelTail = "]]></Nonce>";
sEncryptMsg = sEncryptMsg + "<xml>" + EncryptLabelHead + raw + EncryptLabelTail;
sEncryptMsg = sEncryptMsg + MsgSigLabelHead + MsgSigature + MsgSigLabelTail;
sEncryptMsg = sEncryptMsg + TimeStampLabelHead + sTimeStamp + TimeStampLabelTail;
sEncryptMsg = sEncryptMsg + NonceLabelHead + sNonce + NonceLabelTail;
sEncryptMsg += "</xml>";
return ;
} public class DictionarySort : System.Collections.IComparer
{
public int Compare(object oLeft, object oRight)
{
string sLeft = oLeft as string;
string sRight = oRight as string;
int iLeftLength = sLeft.Length;
int iRightLength = sRight.Length;
int index = ;
while (index < iLeftLength && index < iRightLength)
{
if (sLeft[index] < sRight[index])
return -;
else if (sLeft[index] > sRight[index])
return ;
else
index++;
}
return iLeftLength - iRightLength; }
}
//Verify Signature
private static int VerifySignature(string sToken, string sTimeStamp, string sNonce, string sMsgEncrypt, string sSigture)
{
string hash = "";
int ret = ;
ret = GenarateSinature(sToken, sTimeStamp, sNonce, sMsgEncrypt, ref hash);
if (ret != )
return ret;
//System.Console.WriteLine(hash);
if (hash == sSigture)
return ;
else
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ValidateSignature_Error;
}
} public static int GenarateSinature(string sToken, string sTimeStamp, string sNonce, string sMsgEncrypt, ref string sMsgSignature)
{
ArrayList AL = new ArrayList();
AL.Add(sToken);
AL.Add(sTimeStamp);
AL.Add(sNonce);
AL.Add(sMsgEncrypt);
AL.Sort(new DictionarySort());
string raw = "";
for (int i = ; i < AL.Count; ++i)
{
raw += AL[i];
} SHA1 sha;
ASCIIEncoding enc;
string hash = "";
try
{
sha = new SHA1CryptoServiceProvider();
enc = new ASCIIEncoding();
byte[] dataToHash = enc.GetBytes(raw);
byte[] dataHashed = sha.ComputeHash(dataToHash);
hash = BitConverter.ToString(dataHashed).Replace("-", "");
hash = hash.ToLower();
}
catch (Exception)
{
return (int)WXBizMsgCryptErrorCode.WXBizMsgCrypt_ComputeSignature_Error;
}
sMsgSignature = hash;
return ;
}
}
}
using System;
using System.IO;
using System.Net;
using System.Security.Cryptography;
using System.Text; namespace Core.Common.Wechat
{
/// <summary>
///
/// </summary>
public class Cryptography
{
public static UInt32 HostToNetworkOrder(UInt32 inval)
{
UInt32 outval = ;
for (int i = ; i < ; i++)
outval = (outval << ) + ((inval >> (i * )) & );
return outval;
} public static Int32 HostToNetworkOrder(Int32 inval)
{
Int32 outval = ;
for (int i = ; i < ; i++)
outval = (outval << ) + ((inval >> (i * )) & );
return outval;
}
/// <summary>
/// 解密方法
/// </summary>
/// <param name="Input">密文</param>
/// <param name="EncodingAESKey"></param>
/// <returns></returns>
///
public static string AES_decrypt(String Input, string EncodingAESKey, ref string appid)
{
byte[] Key;
Key = Convert.FromBase64String(EncodingAESKey + "=");
byte[] Iv = new byte[];
Array.Copy(Key, Iv, );
byte[] btmpMsg = AES_decrypt(Input, Iv, Key); int len = BitConverter.ToInt32(btmpMsg, );
len = IPAddress.NetworkToHostOrder(len); byte[] bMsg = new byte[len];
byte[] bAppid = new byte[btmpMsg.Length - - len];
Array.Copy(btmpMsg, , bMsg, , len);
Array.Copy(btmpMsg, + len, bAppid, , btmpMsg.Length - - len);
string oriMsg = Encoding.UTF8.GetString(bMsg);
appid = Encoding.UTF8.GetString(bAppid); return oriMsg;
} public static String AES_encrypt(String Input, string EncodingAESKey, string appid)
{
byte[] Key;
Key = Convert.FromBase64String(EncodingAESKey + "=");
byte[] Iv = new byte[];
Array.Copy(Key, Iv, );
string Randcode = CreateRandCode();
byte[] bRand = Encoding.UTF8.GetBytes(Randcode);
byte[] bAppid = Encoding.UTF8.GetBytes(appid);
byte[] btmpMsg = Encoding.UTF8.GetBytes(Input);
byte[] bMsgLen = BitConverter.GetBytes(HostToNetworkOrder(btmpMsg.Length));
byte[] bMsg = new byte[bRand.Length + bMsgLen.Length + bAppid.Length + btmpMsg.Length]; Array.Copy(bRand, bMsg, bRand.Length);
Array.Copy(bMsgLen, , bMsg, bRand.Length, bMsgLen.Length);
Array.Copy(btmpMsg, , bMsg, bRand.Length + bMsgLen.Length, btmpMsg.Length);
Array.Copy(bAppid, , bMsg, bRand.Length + bMsgLen.Length + btmpMsg.Length, bAppid.Length); return AES_encrypt(bMsg, Iv, Key); }
private static string CreateRandCode(int codeLen)
{
string codeSerial = "2,3,4,5,6,7,a,c,d,e,f,h,i,j,k,m,n,p,r,s,t,A,C,D,E,F,G,H,J,K,M,N,P,Q,R,S,U,V,W,X,Y,Z";
if (codeLen == )
{
codeLen = ;
}
string[] arr = codeSerial.Split(',');
string code = "";
int randValue = -;
Random rand = new Random(unchecked((int)DateTime.Now.Ticks));
for (int i = ; i < codeLen; i++)
{
randValue = rand.Next(, arr.Length - );
code += arr[randValue];
}
return code;
} private static String AES_encrypt(String Input, byte[] Iv, byte[] Key)
{
var aes = new RijndaelManaged();
//秘钥的大小，以位为单位
aes.KeySize = ;
//支持的块大小
aes.BlockSize = ;
//填充模式
aes.Padding = PaddingMode.PKCS7;
aes.Mode = CipherMode.CBC;
aes.Key = Key;
aes.IV = Iv;
var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
byte[] xBuff = null; using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
{
byte[] xXml = Encoding.UTF8.GetBytes(Input);
cs.Write(xXml, , xXml.Length);
}
xBuff = ms.ToArray();
}
String Output = Convert.ToBase64String(xBuff);
return Output;
} private static String AES_encrypt(byte[] Input, byte[] Iv, byte[] Key)
{
var aes = new RijndaelManaged();
//秘钥的大小，以位为单位
aes.KeySize = ;
//支持的块大小
aes.BlockSize = ;
//填充模式
//aes.Padding = PaddingMode.PKCS7;
aes.Padding = PaddingMode.None;
aes.Mode = CipherMode.CBC;
aes.Key = Key;
aes.IV = Iv;
var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);
byte[] xBuff = null; #region 自己进行PKCS7补位，用系统自己带的不行
byte[] msg = new byte[Input.Length + - Input.Length % ];
Array.Copy(Input, msg, Input.Length);
byte[] pad = KCS7Encoder(Input.Length);
Array.Copy(pad, , msg, Input.Length, pad.Length);
#endregion #region 注释的也是一种方法，效果一样
//ICryptoTransform transform = aes.CreateEncryptor();
//byte[] xBuff = transform.TransformFinalBlock(msg, 0, msg.Length);
#endregion using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))
{
cs.Write(msg, , msg.Length);
}
xBuff = ms.ToArray();
} String Output = Convert.ToBase64String(xBuff);
return Output;
} private static byte[] KCS7Encoder(int text_length)
{
int block_size = ;
// 计算需要填充的位数
int amount_to_pad = block_size - (text_length % block_size);
if (amount_to_pad == )
{
amount_to_pad = block_size;
}
// 获得补位所用的字符
char pad_chr = chr(amount_to_pad);
string tmp = "";
for (int index = ; index < amount_to_pad; index++)
{
tmp += pad_chr;
}
return Encoding.UTF8.GetBytes(tmp);
}
/**
* 将数字转化成ASCII码对应的字符，用于对明文进行补码
*
* @param a 需要转化的数字
* @return 转化得到的字符
*/
static char chr(int a)
{ byte target = (byte)(a & 0xFF);
return (char)target;
}
private static byte[] AES_decrypt(String Input, byte[] Iv, byte[] Key)
{
RijndaelManaged aes = new RijndaelManaged();
aes.KeySize = ;
aes.BlockSize = ;
aes.Mode = CipherMode.CBC;
aes.Padding = PaddingMode.None;
aes.Key = Key;
aes.IV = Iv;
var decrypt = aes.CreateDecryptor(aes.Key, aes.IV);
byte[] xBuff = null;
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, decrypt, CryptoStreamMode.Write))
{
byte[] xXml = Convert.FromBase64String(Input);
byte[] msg = new byte[xXml.Length + - xXml.Length % ];
Array.Copy(xXml, msg, xXml.Length);
cs.Write(xXml, , xXml.Length);
}
xBuff = decode2(ms.ToArray());
}
return xBuff;
}
private static byte[] decode2(byte[] decrypted)
{
int pad = (int)decrypted[decrypted.Length - ];
if (pad < || pad > )
{
pad = ;
}
byte[] res = new byte[decrypted.Length - pad];
Array.Copy(decrypted, , res, , decrypted.Length - pad);
return res;
}
}
}