public string Encode(Dictionary <string, object> payload, string secretKey)
{
DateTime now = DateTime.Now;
Base64 base64 = new Base64();
string tokenHeader = base64.UrlEncode(JsonConvert.SerializeObject(new { alg = "HS256", typ = "JWT" }));
payload.Add("iat", TimeConverter.ToTimestamp(now)); // 發行時間
if (!payload.ContainsKey("exp"))
{
payload.Add("exp", TimeConverter.ToTimestamp(now.AddHours(3))); // 到期時間
}
string tokenPayload = base64.UrlEncode(JsonConvert.SerializeObject(payload));
string tokenSignature = new JwsAlgorithm().Hash("HS256", tokenHeader, tokenPayload, secretKey);
return($"{tokenHeader}.{tokenPayload}.{tokenSignature}");
}
public bool Validate(string token, string secretKey)
{ // 實作自己的檢查方法
Regex regex = new Regex(@"^[a-zA-Z0-9_\-]+.[a-zA-Z0-9_\-]+.[a-zA-Z0-9_\-]+$");
if (!regex.IsMatch(token))
{
return(false);
}
long now = TimeConverter.ToTimestamp(DateTime.Now);
string tokenHeader = token.Split('.')[0];
string tokenPayload = token.Split('.')[1];
string tokenSignature = token.Split('.')[2];
Dictionary <string, object> dictHeader, dictPayload;
try
{
Base64 base64 = new Base64();
string jsonHeader = base64.UrlDecode(tokenHeader);
string jsonPayload = base64.UrlDecode(tokenPayload);
dictHeader = JsonConvert.DeserializeObject <Dictionary <string, object> >(jsonHeader);
dictPayload = JsonConvert.DeserializeObject <Dictionary <string, object> >(jsonPayload);
}
catch
{
return(false);
}
string type = dictHeader.ContainsKey("typ") ? ((string)dictHeader["typ"]).ToUpper() : null;
string algorithm = dictHeader.ContainsKey("alg") ? ((string)dictHeader["alg"]).ToUpper() : null;
if (type != null && type != "JWT") // 可以沒有 typ 宣告，但若有則必須為 JWT
{
return(false);
}
if (algorithm != "HS256") // alg 為必要欄位。本實作只接受 HS256
{
return(false);
}
/***
* 與開放規範不同的地方，本次實作將 exp 與 iat 視為必要欄位
*/
if (dictPayload.ContainsKey("exp") && dictPayload.ContainsKey("iat"))
{
long exp = (long)dictPayload["exp"];
long iat = (long)dictPayload["iat"];
// 必須滿足 exp > now > nbf > iat
if (!((exp > iat) && (exp > now)))
{
return(false);
}
if (dictPayload.ContainsKey("nbf"))
{
long nbf = (long)dictPayload["nbf"];
if (!((exp > nbf) && (nbf > iat) && (now > nbf)))
{
return(false);
}
}
}
else
{
return(false);
}
string signature = new JwsAlgorithm().Hash("HS256", tokenHeader, tokenPayload, secretKey);
if (signature != tokenSignature)
{
return(false);
}
return(true);
}
