개발생각

string __niceClientID = 사이트에서 제공해주는 값;
string __niceClientSecret = 사이트에서 제공해주는 값;

#region [ 최초 50년(반영구적) Token 생성 / 토큰 만료 시 처리 ]

public string GetNiceApiAccessToken()
{
    string hostName = "https://svc.niceapi.co.kr:22001";
    string requestUrl = "/digital/niceid/oauth/oauth/token";

    string postData = "grant_type=client_credentials&scope=default";
    byte[] sendData = UTF8Encoding.UTF8.GetBytes(postData);

    string url = hostName + requestUrl;

    HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
    request.ContentType = "application/x-www-form-urlencoded";
    request.Method = "POST";
    request.ContentLength = sendData.Length;

    string text = __niceClientID + ":" + __niceClientSecret;

    byte[] byteUTF8 = Encoding.UTF8.GetBytes(text);
    string base64UTF8 = Convert.ToBase64String(byteUTF8);

    request.Headers.Add("Authorization", "Basic " + base64UTF8);

    try
    {
        Stream requestStream = request.GetRequestStream();
        requestStream.Write(sendData, 0, sendData.Length);
        requestStream.Close();

        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader responseStream = new StreamReader(response.GetResponseStream());
        string rawData = responseStream.ReadToEnd();
        parser = new JsonTextParser();
        JObject obj = JObject.Parse(rawData);

        JToken jToken = obj["dataBody"];
        accessToken = jToken.SelectToken("access_token").ToString();

        message = rawData;

        return "OK";
    }
    catch (System.Exception ex)
    {
        message = ex.Message.ToString();
        return ex.Message.ToString();
    }
}

#endregion

string __accessToken = 인증 기관 토큰 (위 소스에서 부여받은 값);
string __productID = 사이트에서 제공해주는 값;

#region [ 암호화 토큰 발급 ]

private string GetNiceApiEncryptToken()
{
    string hostName = "https://svc.niceapi.co.kr:22001";
    string requestUrl = "/digital/niceid/api/v1.0/common/crypto/token";
    
    string url = hostName + requestUrl;

    req_dtim = DateTime.Now.ToString("yyyyMMddHHmmss");
    req_no = Convert.ToBase64String(Guid.NewGuid().ToByteArray());

    HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);

    double unixTimeStamp = DateTime.Now.Subtract(new DateTime(1970, 1, 1)).TotalSeconds;
    string text = __accessToken + ":" + (int)unixTimeStamp + ":" + __niceClientID;
    byte[] byteUTF8 = Encoding.UTF8.GetBytes(text);
    string base64UTF8 = Convert.ToBase64String(byteUTF8);

    request.Headers.Add("Authorization", "bearer " + base64UTF8);
    request.Headers.Add("client_id", client_id);
    request.Headers.Add("productID", productID);
    request.ContentType = "application/json";
    request.Method = "POST";

    var streamWriter = new StreamWriter(request.GetRequestStream());

    try
    {
        string strData = "{\"dataHeader\": {\"CNTY_CD\":\"ko\"}, \"dataBody\":{\"req_dtim\":\"" + req_dtim + "\",\"req_no\":\"" + req_no + "\",\"enc_mode\":\"1\"}}";
        JObject jsonData = JObject.Parse(strData);

        streamWriter.Write(strData);
        streamWriter.Flush();
        streamWriter.Close();

        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader responseStream = new StreamReader(response.GetResponseStream());
        string rawData = responseStream.ReadToEnd();

        JsonTextParser parser = new JsonTextParser();
        JObject obj = JObject.Parse(rawData);
        
        JToken jToken = obj["databody"];
        string token_val = jToken.SelectToken("token_val").ToString();
        string token_version_id = jToken.SelectToken("token_version_id").ToString();
        string siteCode = jToken.SelectToken("site_code").ToString();

        JToken jTokenHeader = obj["dataHeader"];
        resultCode = jTokenHeader.SelectToken("GW_RSLT_CD").ToString();

        // 성공시 키 발급 처리
        if (resultCode 성공시)
        {
            // 대칭키
            string strValue = req_dtim.Trim() + req_no.Trim() + token_val.Trim();

            SHA256Managed sha256 = new SHA256Managed();
            byte[] encryptBytes = sha256.ComputeHash(Encoding.ASCII.GetBytes(strValue));

            string strKeyValue = Convert.ToBase64String(encryptBytes);

            // 대칭키(Symmetric Key, IV), 무결성 키 생성
            string sKey = strKeyValue.Substring(0, 16);
            string IV = strKeyValue.Substring(strKeyValue.Length - 16);
            string encryptedHMacKey = strKeyValue.Substring(0, 32);

            string strRequestNo = Convert.ToBase64String(Guid.NewGuid().ToByteArray());

            string strRequestData = "{\"requestno\":\"" + strRequestNo + "\",\"returnurl\":\"" + HttpContext.Current.Request.Url.AbsoluteUri + "\",\"sitecode\":\"" + siteCode + "\",\"methodtype\":\"post\",\"popupyn\":\"Y\"}";

            try
            {
                RijndaelManaged rijndaeManaged = new RijndaelManaged();
                rijndaeManaged.Mode = CipherMode.CBC;
                rijndaeManaged.Padding = PaddingMode.PKCS7;
                rijndaeManaged.Key = Encoding.ASCII.GetBytes(sKey);
                rijndaeManaged.IV = Encoding.ASCII.GetBytes(IV);

                byte[] encDataByte = EncryptStringToBytes(strRequestData, rijndaeManaged.Key, rijndaeManaged.IV);
                enc_data = Convert.ToBase64String(encDataByte);

                byte[] hmacKeyByte = Encoding.UTF8.GetBytes(encryptedHMacKey);
                HMACSHA256 sha = new HMACSHA256(hmacKeyByte);
                byte[] integrityValueByte = sha.ComputeHash(Encoding.ASCII.GetBytes(enc_data));

                integrity_value = Convert.ToBase64String(integrityValueByte);

            }
            catch (System.Exception ex)
            {
                message = ex.Message.ToString();
                return ex.Message.ToString();
            }
        }

        return "";

    }
    catch (System.Exception ex)
    {
        message = ex.Message.ToString();
        return ex.Message.ToString();
    }
}

#endregion

#region [ Byte를 EncryptString으로 변환 ]

protected byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
{
    // Check arguments. 
    if (plainText == null || plainText.Length <= 0)
        throw new ArgumentNullException("plainText");
    if (Key == null || Key.Length <= 0)
        throw new ArgumentNullException("Key");
    if (IV == null || IV.Length <= 0)
        throw new ArgumentNullException("Key");
    byte[] encrypted;

    using (RijndaelManaged rijAlg = new RijndaelManaged())
    {
        rijAlg.Key = Key;
        rijAlg.IV = IV;

        // Create a decrytor to perform the stream transform.
        ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

        // Create the streams used for encryption. 
        using (MemoryStream msEncrypt = new MemoryStream())
        {
            using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
            {
                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                {

                    //Write all data to the stream.
                    swEncrypt.Write(plainText);
                }
                encrypted = msEncrypt.ToArray();
            }
        }
    }

    // Return the encrypted bytes from the memory stream. 
    return encrypted;

}

#endregion