Updated on 2024-02-18 GMT+08:00

C#

This section uses Visual Studio as an example to describe how to integrate the C# SDK for API request signing. You can import the sample project in the code package, and integrate the signing SDK into your application by referring to the API calling example.

Preparing the Environment

Download Visual Studio from the Visual Studio official website and install it.

Obtaining the SDK

Download the SDK and demo.

The following table shows the directory structure of the downloaded package.

Name

Description

apigateway-signature\Signer.cs

SDK code

apigateway-signature\HttpEncoder.cs

sdk-request\Program.cs

Sample code for signing requests

csharp.sln

Project file

licenses\license-referencesource

Third-party license

Opening the Sample Project

Double-click csharp.sln in the SDK package to open the project. apigateway-signature is a shared library that implements the signature algorithm. It can be used in .Net Framework and .Net Core projects. The sdk-request project is used as an example.

Request Signing and API Calling

  1. Import the SDK to the project.

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    using System;
    using System.Net;
    using System.IO;
    using System.Net.Http;
    using System.Threading;
    using APIGATEWAY_SDK;
    

  2. Generate a new signer and enter the AK and SK.

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    Signer signer = new Signer();
    // Directly writing AK/SK in code is risky. For security, encrypt your AK/SK and store them in the configuration file or environment variables.
    // In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, set environment variables HUAWEICLOUD_SDK_AK and HUAWEICLOUD_SDK_SK.
    signer.Key = Environment.GetEnvironmentVariable("HUAWEICLOUD_SDK_AK");
    signer.Secret = Environment.GetEnvironmentVariable("HUAWEICLOUD_SDK_SK");
    

  3. Generate a new request, and specify the domain name, method, request URI, and body.

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    //The following example shows how to set the request URL and parameters to query a VPC list.
    HttpRequest r = new HttpRequest("GET", new Uri("https://{service}.region.example.com/v1/77b6a44cba5**********9a8ff44fd/vpcs?limit=1"));
    //Add a body if you have specified the PUT or POST method. Special characters, such as the double quotation mark ("), contained in the body must be escaped.
    r.body = "";
    

  4. Add other headers required for request signing or other purposes. For example, add the X-Project-Id header in multi-project scenarios or the X-Domain-Id header for a global service.

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    //Add header parameters, for example, X-Domain-Id for invoking a global service and X-Project-Id for invoking a project-level service.
    r.headers.Add("X-Project-Id", "xxx");
    

  5. Execute the following function to generate HttpWebRequest, and add the X-Sdk-Date and Authorization headers for signing the request:

    If you use HttpClient, you can obtain header information from the request. For details about headers, see AK/SK Signing and Authentication Algorithm.
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    HttpWebRequest req = signer.Sign(r);
    

  6. Access the API and view the access result.

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    try
    {
        var writer = new StreamWriter(req.GetRequestStream());
        writer.Write(r.body);
        writer.Flush();
        HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
        var reader = new StreamReader(resp.GetResponseStream());
        Console.WriteLine(reader.ReadToEnd());
    }
    catch (WebException e)
    {
        HttpWebResponse resp = (HttpWebResponse)e.Response;
        if (resp != null)
        {
            Console.WriteLine((int)resp.StatusCode + " " + resp.StatusDescription);
            var reader = new StreamReader(resp.GetResponseStream());
            Console.WriteLine(reader.ReadToEnd());
        }
        else
        {
            Console.WriteLine(e.Message);
        }
    }
    Console.WriteLine("----------------");