如何在 C# 中获取 OAuth 2.0 身份验证令牌

在 Postman 中，单击 Generate Code，然后在 Generate Code Snippets 对话框中，您可以选择不同的编码语言，包括 C# (RestSharp)。

此外，您应该只需要访问令牌 URL。那么表单参数是：

grant_type=client_credentials
client_id=abc    
client_secret=123

代码片段：

/* using RestSharp; // https://www.nuget.org/packages/RestSharp/ */

var client = new RestClient("https://service.endpoint.com/api/oauth2/token");
var request = new RestRequest(Method.POST);
request.AddHeader("cache-control", "no-cache");
request.AddHeader("content-type", "application/x-www-form-urlencoded");
request.AddParameter("application/x-www-form-urlencoded", "grant_type=client_credentials&client_id=abc&client_secret=123", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);

然后，您可以从响应正文中获取您的访问令牌。例如，对于 Bearer 令牌类型，您可以将以下标头添加到后续经过身份验证的请求中：

request.AddHeader("authorization", "Bearer <access_token>");

---

休息客户的答案是完美的！ （我赞成）

但是，以防万一你想“生”

…………

我让它与 HttpClient 一起工作。

“抽象地”你正在做的是

创建一个 POST 请求。带有“x-www-form-urlencoded”的有效负载“类型”主体。 （请参阅 FormUrlEncodedContent https://docs.microsoft.com/en-us/dotnet/api/system.net.http.formurlencodedcontent?view=net-5.0 并注意构造函数：https://docs.microsoft.com/en -us/dotnet/api/system.net.http.formurlencodedcontent.-ctor?view=net-5.0) 并在“类型”的有效负载中：x-www-form-urlencoded，您正在输入某些值，例如grant_type 、client_id、client_secret 等。

旁注，尝试让它在 PostMan 中工作，然后使用下面的代码更容易“编码”。

但是我们开始了，使用 HttpClient 的代码。

…………

/*
.nuget\packages\newtonsoft.json\12.0.1
.nuget\packages\system.net.http\4.3.4
*/
        
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using System.Web;
    
    
    private static async Task<Token> GetElibilityToken(HttpClient client)
    {
        string baseAddress = @"https://blah.blah.blah.com/oauth2/token";

        string grant_type = "client_credentials";
        string client_id = "myId";
        string client_secret = "shhhhhhhhhhhhhhItsSecret";

        var form = new Dictionary<string, string>
                {
                    {"grant_type", grant_type},
                    {"client_id", client_id},
                    {"client_secret", client_secret},
                };

        HttpResponseMessage tokenResponse = await client.PostAsync(baseAddress, new FormUrlEncodedContent(form));
        var jsonContent = await tokenResponse.Content.ReadAsStringAsync();
        Token tok = JsonConvert.DeserializeObject<Token>(jsonContent);
        return tok;
    }
    
    
internal class Token
{
    [JsonProperty("access_token")]
    public string AccessToken { get; set; }

    [JsonProperty("token_type")]
    public string TokenType { get; set; }

    [JsonProperty("expires_in")]
    public int ExpiresIn { get; set; }

    [JsonProperty("refresh_token")]
    public string RefreshToken { get; set; }
}       

这是另一个工作示例（基于上面的答案）......还有一些调整。有时令牌服务很挑剔：

    private static async Task<Token> GetATokenToTestMyRestApiUsingHttpClient(HttpClient client)
    {
        /* this code has lots of commented out stuff with different permutations of tweaking the request  */

        /* this is a version of asking for token using HttpClient.  aka, an alternate to using default libraries instead of RestClient */

        OAuthValues oav = GetOAuthValues(); /* object has has simple string properties for TokenUrl, GrantType, ClientId and ClientSecret */

        var form = new Dictionary<string, string>
                {
                    { "grant_type", oav.GrantType },
                    { "client_id", oav.ClientId },
                    { "client_secret", oav.ClientSecret }
                };

        /* now tweak the http client */
        client.DefaultRequestHeaders.Clear();
        client.DefaultRequestHeaders.Add("cache-control", "no-cache");

        /* try 1 */
        ////client.DefaultRequestHeaders.Add("content-type", "application/x-www-form-urlencoded");

        /* try 2 */
        ////client.DefaultRequestHeaders            .Accept            .Add(new MediaTypeWithQualityHeaderValue("application/x-www-form-urlencoded"));//ACCEPT header

        /* try 3 */
        ////does not compile */client.Content.Headers.ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded");

        ////application/x-www-form-urlencoded

        HttpRequestMessage req = new HttpRequestMessage(HttpMethod.Post, oav.TokenUrl);
        /////req.RequestUri = new Uri(baseAddress);
        
        req.Content = new FormUrlEncodedContent(form);

        ////string jsonPayload = "{\"grant_type\":\"" + oav.GrantType + "\",\"client_id\":\"" + oav.ClientId + "\",\"client_secret\":\"" + oav.ClientSecret + "\"}";
        ////req.Content = new StringContent(jsonPayload,                                                Encoding.UTF8,                                                "application/json");//CONTENT-TYPE header

        req.Content.Headers.ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded");

        /* now make the request */
        ////HttpResponseMessage tokenResponse = await client.PostAsync(baseAddress, new FormUrlEncodedContent(form));
        HttpResponseMessage tokenResponse = await client.SendAsync(req);
        Console.WriteLine(string.Format("HttpResponseMessage.ReasonPhrase='{0}'", tokenResponse.ReasonPhrase));

        if (!tokenResponse.IsSuccessStatusCode)
        {
            throw new HttpRequestException("Call to get Token with HttpClient failed.");
        }

        var jsonContent = await tokenResponse.Content.ReadAsStringAsync();
        Token tok = JsonConvert.DeserializeObject<Token>(jsonContent);

        return tok;
    }

附加

奖励材料！

如果你得到一个

“根据验证程序，远程证书无效。”

异常......您可以连接处理程序以查看发生了什么（并在必要时进行按摩）

using System;
using System.Collections.Generic;
using System.Text;
using Newtonsoft.Json;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using System.Web;
using System.Net;

namespace MyNamespace
{
    public class MyTokenRetrieverWithExtraStuff
    {
        public static async Task<Token> GetElibilityToken()
        {
            using (HttpClientHandler httpClientHandler = new HttpClientHandler())
            {
                httpClientHandler.ServerCertificateCustomValidationCallback = CertificateValidationCallBack;
                using (HttpClient client = new HttpClient(httpClientHandler))
                {
                    return await GetElibilityToken(client);
                }
            }
        }

        private static async Task<Token> GetElibilityToken(HttpClient client)
        {
            // throws certificate error if your cert is wired to localhost // 
            //string baseAddress = @"https://127.0.0.1/someapp/oauth2/token";

            //string baseAddress = @"https://localhost/someapp/oauth2/token";

        string baseAddress = @"https://blah.blah.blah.com/oauth2/token";

        string grant_type = "client_credentials";
        string client_id = "myId";
        string client_secret = "shhhhhhhhhhhhhhItsSecret";

        var form = new Dictionary<string, string>
                {
                    {"grant_type", grant_type},
                    {"client_id", client_id},
                    {"client_secret", client_secret},
                };

            HttpResponseMessage tokenResponse = await client.PostAsync(baseAddress, new FormUrlEncodedContent(form));
            var jsonContent = await tokenResponse.Content.ReadAsStringAsync();
            Token tok = JsonConvert.DeserializeObject<Token>(jsonContent);
            return tok;
        }

        private static bool CertificateValidationCallBack(
        object sender,
        System.Security.Cryptography.X509Certificates.X509Certificate certificate,
        System.Security.Cryptography.X509Certificates.X509Chain chain,
        System.Net.Security.SslPolicyErrors sslPolicyErrors)
        {
            // If the certificate is a valid, signed certificate, return true.
            if (sslPolicyErrors == System.Net.Security.SslPolicyErrors.None)
            {
                return true;
            }

            // If there are errors in the certificate chain, look at each error to determine the cause.
            if ((sslPolicyErrors & System.Net.Security.SslPolicyErrors.RemoteCertificateChainErrors) != 0)
            {
                if (chain != null && chain.ChainStatus != null)
                {
                    foreach (System.Security.Cryptography.X509Certificates.X509ChainStatus status in chain.ChainStatus)
                    {
                        if ((certificate.Subject == certificate.Issuer) &&
                           (status.Status == System.Security.Cryptography.X509Certificates.X509ChainStatusFlags.UntrustedRoot))
                        {
                            // Self-signed certificates with an untrusted root are valid. 
                            continue;
                        }
                        else
                        {
                            if (status.Status != System.Security.Cryptography.X509Certificates.X509ChainStatusFlags.NoError)
                            {
                                // If there are any other errors in the certificate chain, the certificate is invalid,
                                // so the method returns false.
                                return false;
                            }
                        }
                    }
                }

                // When processing reaches this line, the only errors in the certificate chain are 
                // untrusted root errors for self-signed certificates. These certificates are valid
                // for default Exchange server installations, so return true.
                return true;
            }


            /* overcome localhost and 127.0.0.1 issue */
            if ((sslPolicyErrors & System.Net.Security.SslPolicyErrors.RemoteCertificateNameMismatch) != 0)
            {
                if (certificate.Subject.Contains("localhost"))
                {
                    HttpRequestMessage castSender = sender as HttpRequestMessage;
                    if (null != castSender)
                    {
                        if (castSender.RequestUri.Host.Contains("127.0.0.1"))
                        {
                            return true;
                        }
                    }
                }
            }

            return false;

        }


        public class Token
        {
            [JsonProperty("access_token")]
            public string AccessToken { get; set; }

            [JsonProperty("token_type")]
            public string TokenType { get; set; }

            [JsonProperty("expires_in")]
            public int ExpiresIn { get; set; }

            [JsonProperty("refresh_token")]
            public string RefreshToken { get; set; }
        }

    }
}

………………………………………………………………………………

我最近发现（2020 年 1 月）一篇关于这一切的文章。我会在这里添加一个链接....有时有 2 个不同的人展示/解释它可以帮助尝试学习它的人。

http://luisquintanilla.me/2017/12/25/client-credentials-authentication-csharp/

---

这是一个完整的例子。右键管理nuget包的解决方案，获取Newtonsoft和RestSharp：

using Newtonsoft.Json.Linq;
using RestSharp;
using System;


namespace TestAPI
{
    class Program
    {
        static void Main(string[] args)
        {
            String id = "xxx";
            String secret = "xxx";

            var client = new RestClient("https://xxx.xxx.com/services/api/oauth2/token");
            var request = new RestRequest(Method.POST);
            request.AddHeader("cache-control", "no-cache");
            request.AddHeader("content-type", "application/x-www-form-urlencoded");
            request.AddParameter("application/x-www-form-urlencoded", "grant_type=client_credentials&scope=all&client_id=" + id + "&client_secret=" + secret, ParameterType.RequestBody);
            IRestResponse response = client.Execute(request);

            dynamic resp = JObject.Parse(response.Content);
            String token = resp.access_token;            

            client = new RestClient("https://xxx.xxx.com/services/api/x/users/v1/employees");
            request = new RestRequest(Method.GET);
            request.AddHeader("authorization", "Bearer " + token);
            request.AddHeader("cache-control", "no-cache");
            response = client.Execute(request);
        }        
    }
}

---

我使用 ADAL.NET/Microsoft Identity Platform 来实现这一点。使用它的好处是我们获得了一个很好的代码包装器来获取 AccessToken，并且我们获得了开箱即用的 Token Cache 等附加功能。从 documentation：

为什么使用 ADAL.NET？ ADAL.NET V3（.NET 的 Active Directory 身份验证库）使 .NET 应用程序的开发人员能够获取令牌，以便调用安全的 Web API。这些 Web API 可以是 Microsoft Graph 或第 3 方 Web API。

这是代码片段：

    // Import Nuget package: Microsoft.Identity.Client
    public class AuthenticationService
    {
         private readonly List<string> _scopes;
         private readonly IConfidentialClientApplication _app;

        public AuthenticationService(AuthenticationConfiguration authentication)
        {

             _app = ConfidentialClientApplicationBuilder
                         .Create(authentication.ClientId)
                         .WithClientSecret(authentication.ClientSecret)
                         .WithAuthority(authentication.Authority)
                         .Build();

           _scopes = new List<string> {$"{authentication.Audience}/.default"};
       }

       public async Task<string> GetAccessToken()
       {
           var authenticationResult = await _app.AcquireTokenForClient(_scopes) 
                                                .ExecuteAsync();
           return authenticationResult.AccessToken;
       }
   }

---

您可以使用以下代码获取不记名令牌。

private string GetBearerToken()
{
    var client = new RestClient("https://service.endpoint.com");
    client.Authenticator = new HttpBasicAuthenticator("abc", "123");
    var request = new RestRequest("api/oauth2/token", Method.POST);
    request.AddHeader("content-type", "application/json");
    request.AddParameter("application/json", "{ \"grant_type\":\"client_credentials\" }", 
    ParameterType.RequestBody);
    var responseJson = _client.Execute(request).Content;
    var token = JsonConvert.DeserializeObject<Dictionary<string, object>>(responseJson)["access_token"].ToString();
    if(token.Length == 0)
    {
        throw new AuthenticationException("API authentication failed.");
    }
    return token;
}

---

这个例子得到令牌thouth HttpWebRequest

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(pathapi);
        request.Method = "POST";
        string postData = "grant_type=password";
        ASCIIEncoding encoding = new ASCIIEncoding();
        byte[] byte1 = encoding.GetBytes(postData);

        request.ContentType = "application/x-www-form-urlencoded";

        request.ContentLength = byte1.Length;
        Stream newStream = request.GetRequestStream();
        newStream.Write(byte1, 0, byte1.Length);

        HttpWebResponse response = request.GetResponse() as HttpWebResponse;            
        using (Stream responseStream = response.GetResponseStream())
        {
            StreamReader reader = new StreamReader(responseStream, Encoding.UTF8);
            getreaderjson = reader.ReadToEnd();
        }

---

清楚地：

服务器端生成令牌示例

private string GenerateToken(string userName)
{
    var someClaims = new Claim[]{
        new Claim(JwtRegisteredClaimNames.UniqueName, userName),
        new Claim(JwtRegisteredClaimNames.Email, GetEmail(userName)),
        new Claim(JwtRegisteredClaimNames.NameId,Guid.NewGuid().ToString())
    };

    SecurityKey securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_settings.Tokenizer.Key));
    var token = new JwtSecurityToken(
        issuer: _settings.Tokenizer.Issuer,
        audience: _settings.Tokenizer.Audience,
        claims: someClaims,
        expires: DateTime.Now.AddHours(_settings.Tokenizer.ExpiryHours),
        signingCredentials: new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256)
    );

    return new JwtSecurityTokenHandler().WriteToken(token);
}

（注意：Tokenizer 是我的助手类，其中包含 Issuer Audience 等。）

确实：

客户端获取令牌进行身份验证

    public async Task<string> GetToken()
    {
        string token = "";
        var siteSettings = DependencyResolver.Current.GetService<SiteSettings>();

        var client = new HttpClient();
        client.BaseAddress = new Uri(siteSettings.PopularSearchRequest.StaticApiUrl);
        client.DefaultRequestHeaders.Accept.Clear();
        //client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        StatisticUserModel user = new StatisticUserModel()
        {
            Password = siteSettings.PopularSearchRequest.Password,
            Username = siteSettings.PopularSearchRequest.Username
        };

        string jsonUser = JsonConvert.SerializeObject(user, Formatting.Indented);
        var stringContent = new StringContent(jsonUser, Encoding.UTF8, "application/json");
        var response = await client.PostAsync(siteSettings.PopularSearchRequest.StaticApiUrl + "/api/token/new", stringContent);
        token = await response.Content.ReadAsStringAsync();

        return token;
    }

您可以使用此令牌进行授权（即在后续请求中）

---

https://github.com/IdentityModel/IdentityModel 为 HttpClient 添加了扩展以使用不同的流程获取令牌，并且文档也很棒。它非常方便，因为您不必自己考虑如何实现它。我不知道是否存在任何官方的 MS 实现。

---

我尝试通过这种方式使用 c# 获取 OAuth 2.0 身份验证令牌

namespace ConsoleApp2
{

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(GetToken());
            Console.Read();
        }

        /// <summary>
        /// Get access token from api
        /// </summary>
        /// <returns></returns>
        private static string GetToken()
        {
            string wClientId = "#######";
            string wClientSecretKey = "*********************";
            string wAccessToken;

//--------------------------- Approch-1 to get token using HttpClient -------------------------------------------------------------------------------------
            HttpResponseMessage responseMessage;
            using (HttpClient client = new HttpClient())
            {
                HttpRequestMessage tokenRequest = new HttpRequestMessage(HttpMethod.Post, "https://localhost:1001/oauth/token");
                HttpContent httpContent = new FormUrlEncodedContent(
                        new[]
                        {
                                        new KeyValuePair<string, string>("grant_type", "client_credentials"),
                        });
                tokenRequest.Content = httpContent;
                tokenRequest.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.Default.GetBytes(wClientId + ":" + wClientSecretKey)));
                responseMessage =  client.SendAsync(tokenRequest).Result;
            }
            string ResponseJSON=   responseMessage.Content.ReadAsStringAsync().Result;


//--------------------------- Approch-2 to get token using HttpWebRequest and deserialize json object into ResponseModel class -------------------------------------------------------------------------------------


            byte[] byte1 = Encoding.ASCII.GetBytes("grant_type=client_credentials");

            HttpWebRequest oRequest = WebRequest.Create("https://localhost:1001/oauth/token") as HttpWebRequest;
            oRequest.Accept = "application/json";
            oRequest.Method = "POST";
            oRequest.ContentType = "application/x-www-form-urlencoded";
            oRequest.ContentLength = byte1.Length;
            oRequest.KeepAlive = false;
            oRequest.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(Encoding.Default.GetBytes(wClientId + ":" + wClientSecretKey)));
            Stream newStream = oRequest.GetRequestStream();
            newStream.Write(byte1, 0, byte1.Length);

            WebResponse oResponse = oRequest.GetResponse();

            using (var reader = new StreamReader(oResponse.GetResponseStream(), Encoding.UTF8))
            {
                var oJsonReponse = reader.ReadToEnd();
                ResponseModel oModel = JsonConvert.DeserializeObject<ResponseModel>(oJsonReponse);
                wAccessToken = oModel.access_token;
            }

            return wAccessToken;
        }
    }
  
  //----------------------------------------------------------------------------------------------------------------------------------------------------
  //---------------------------------- Response Class---------------------------------------------------------------------------------------
  //----------------------------------------------------------------------------------------------------------------------------------------------------

    /// <summary>
    /// De-serialize Web response Object into model class to read  
    /// </summary>
    public class ResponseModel
    {
        public string scope { get; set; }
        public string token_type { get; set; }
        public string expires_in { get; set; }
        public string refresh_token { get; set; }
        public string access_token { get; set; }
    }
}

---

我的客户正在使用 grant_type=Authorization_code 工作流程。

我有以下设置：

Auth URL（恰好是“https://login.microsoftonline.com/...”）如果有帮助的话。

访问令牌 URL：“https://service.endpoint.com/api/oauth2/token” ClientId：“xyz” Clientsecret：“123dfsdf”

然后，我需要使用标头中的不记名令牌进行 get 调用。我尝试了上述所有代码示例，但无论我将登陆 Microsoft - 登录到您的帐户”页面为

"\r\n\r\n<!-- Copyright (C) Microsoft Corporation. All rights reserved. -->\r\n<!DOCTYPE html>\r\n<html dir=\"ltr\" class=\"\" lang=\"en\">\r\n<head>\r\n    <title>Sign in to your account</title>\r\n "

我能够在 Postman 上执行，我观察到控制台中有 2 个调用。

GET 调用授权代码 POST 调用，上面的授权代码附加在对访问令牌的调用中。

我尝试在 POSTMAN 中单独执行上述 GET 调用，当我这样做时，我会收到 microsoftonline 登录页面的提示，当我输入我的凭据时，我会收到 salesforce 错误。

如果有人可以提供 Authorization_code grand_type 工作流程的示例代码或示例，那将非常有帮助...

---