/// <summary>
/// 解析JWT令牌
/// </summary>
/// <param name="token">JWT令牌</param>
/// <param name="claim">Claim名称</param>
/// <returns>返回指定的Claim值，解析失败返回null</returns>
public object Parse(string token, JwtClaimNames claim)
{
if (string.IsNullOrWhiteSpace(token))
{
throw new ArgumentException(nameof(token));
}
// 令牌解密
string jwtStr;
if (_useAes)
{
var jwtBytes = JwtBase64Url.Decode(token); // 解码
jwtStr = Encoding.UTF8.GetString(Aes.Decrypt(jwtBytes)); // 解密
}
else
{
jwtStr = token;
}
var parts = jwtStr.Split('.');
if (parts.Length != 3)
{
throw new ArgumentOutOfRangeException(token, "令牌必须由3个由点分隔的部分组成");
}
// 解码负载
var payloadDecode = JwtBase64Url.Decode(parts[1]);
var json = Encoding.UTF8.GetString(payloadDecode);
var claims = Json.Json.Deserialize <IDictionary <string, object> >(json);
if (claims != null && claims.TryGetValue(claim.ToStr(), out var result))
{
return(result);
}
return(null);
}
/// <summary>
/// 校验JWT令牌是否有效
/// </summary>
/// <param name="token">JWT令牌</param>
/// <returns>有效返回空字符串，无效返回错误</returns>
public string Verify(string token)
{
string errMsg = "";
try
{
if (string.IsNullOrWhiteSpace(token))
{
throw new ArgumentException(nameof(token));
}
// 令牌解密
string jwtStr;
if (_useAes)
{
var jwtBytes = JwtBase64Url.Decode(token); // 解码
jwtStr = Encoding.UTF8.GetString(Aes.Decrypt(jwtBytes)); // 解密
}
else
{
jwtStr = token;
}
var parts = jwtStr.Split('.');
if (parts.Length != 3)
{
throw new ArgumentOutOfRangeException(token, "令牌必须由3个由点分隔的部分组成");
}
// 验证签名
var header = parts[0]; // 头
var payload = parts[1]; // 负载
// 根据密钥和算法生成签名
var key = Encoding.UTF8.GetBytes(_secret);
var signatureData = $"{header}.{payload}"; // 生成签名数据
var signatureBytes = Encoding.UTF8.GetBytes(signatureData); // 编码成UTF8
byte[] signatureSha;
switch (_algorithm) // 进行签名
{
case JwtSecurityAlgorithms.HmacSha256: signatureSha = Hash.HSha256(key, signatureBytes); break;
case JwtSecurityAlgorithms.HmacSha384: signatureSha = Hash.HSha384(key, signatureBytes); break;
case JwtSecurityAlgorithms.HmacSha512: signatureSha = Hash.HSha512(key, signatureBytes); break;
default: throw new InvalidOperationException($"不支持的签名算法[{_algorithm}]");
}
var signatureStr = JwtBase64Url.Encode(signatureSha); // 编码成Base64Url
if (!signatureStr.Equals(parts[2], StringComparison.InvariantCultureIgnoreCase)) // 比对签名
{
throw new Exception("令牌属于伪造");
}
return(errMsg);
}
catch (Exception e)
{
errMsg = e.Message;
}
return(errMsg);
}
/// <summary>
/// 生成JWT令牌
/// </summary>
/// <returns>返回生成的JWT令牌</returns>
public string Build()
{
// JWT令牌
var jwt = new List <string>(3);
// 创建头部
_header["typ"] = "JWT"; // 类型
_header["alg"] = _algorithm.ToStr(); // 算法
var headerJson = Json.Json.Serialize(_header); // 序列化成Json
var headerBytes = Encoding.UTF8.GetBytes(headerJson); // 编码成UTF8
var headerStr = JwtBase64Url.Encode(headerBytes); // 编码成Base64Url
jwt.Add(headerStr);
// 创建负载
if (!_payload.ContainsKey(JwtClaimNames.Issuer.ToStr())) // 签发人
{
_payload[JwtClaimNames.Issuer.ToStr()] = "eLong.Tech";
}
if (!_payload.ContainsKey(JwtClaimNames.IssuedAt.ToStr())) // 颁发时间
{
_payload[JwtClaimNames.IssuedAt.ToStr()] = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture);
}
if (!_payload.ContainsKey(JwtClaimNames.NotBefore.ToStr())) // 生效时间
{
_payload[JwtClaimNames.NotBefore.ToStr()] = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture);
}
if (!_payload.ContainsKey(JwtClaimNames.ExpirationTime.ToStr())) // 过期时间(默认2小时)
{
_payload[JwtClaimNames.ExpirationTime.ToStr()] = DateTime.Now.AddHours(2).ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture);
}
_payload[JwtClaimNames.JwtId.ToStr()] = new GuidCombGenerator().NextId(); // 为Jwt指定一个UID，由于JWT令牌很长，此UID用来在Redis等缓存中标识其唯一性减少空间占用非常有用。
var payloadJson = Json.Json.Serialize(_payload); // 序列化成Json
var payloadBytes = Encoding.UTF8.GetBytes(payloadJson); // 编码成UTF8
var payloadStr = JwtBase64Url.Encode(payloadBytes); // 编码成Base64Url
jwt.Add(payloadStr);
// 根据密钥和算法生成签名
var key = Encoding.UTF8.GetBytes(_secret);
var signatureData = string.Join(".", jwt.ToArray()); // 生成签名数据
var signatureBytes = Encoding.UTF8.GetBytes(signatureData); // 编码成UTF8
byte[] signatureSha;
switch (_algorithm) // 进行签名
{
case JwtSecurityAlgorithms.HmacSha256: signatureSha = Hash.HSha256(key, signatureBytes); break;
case JwtSecurityAlgorithms.HmacSha384: signatureSha = Hash.HSha384(key, signatureBytes); break;
case JwtSecurityAlgorithms.HmacSha512: signatureSha = Hash.HSha512(key, signatureBytes); break;
default: throw new InvalidOperationException($"不支持的签名算法[{_algorithm}]");
}
var signatureStr = JwtBase64Url.Encode(signatureSha); // 编码成Base64Url
jwt.Add(signatureStr);
// 生成令牌
var jwtStr = string.Join(".", jwt.ToArray());
// 返回令牌
if (_useAes)
{
var jwtResult = JwtBase64Url.Encode(Aes.Encrypt(Encoding.UTF8.GetBytes(jwtStr))); // 对JWT令牌进行二次加密，防止恶意解开头和负载部分
return(jwtResult);
}
else
{
return(jwtStr);
}
}
