Mengakses Layanan Mail menggunakan OAuth
Aspose.Email untuk .NET mendukung OAuth 2.0, yang dapat digunakan untuk mengakses server SMTP, POP3, IMAP, dan EWS. Secara umum, server apa pun yang mendukung token bearer OAuth 2.0 dapat digunakan dengan Aspose.Email, namun klien email telah diuji dengan server mail Google dan server Microsoft Office 365.
Akses ke server dari SmtpClient, Pop3Client, ImapClient, dan EWSClient dengan OAuth dapat diimplementasikan dalam dua cara:
- Berikan token akses secara langsung ke konstruktor klien email. Dalam hal ini, Anda harus ingat bahwa masa hidup token akses terbatas. Ketika token kedaluwarsa, klien email tidak dapat lagi digunakan untuk mengakses server.
- Berikan implementasi khusus dari penyedia token berdasarkan ITokenProvider antarmuka ke konstruktor klien email. Dalam hal ini, klien memeriksa waktu kedaluwarsa token dan meminta token akses baru dari ITokenProvider ketika yang sebelumnya telah kedaluwarsa. Dengan cara ini, klien menyegarkan token secara berkala dan dapat bekerja dengan server tanpa batas waktu. Sebagian besar layanan mendukung cara sederhana untuk menyegarkan token akses. Misalnya, token penyegaran di layanan Google, atau alur autentikasi ROPC di platform identitas Microsoft, dapat digunakan untuk mengimplementasikan penyedia token.
Konfigurasikan Akun pada Server yang Tepat
Artikel berikut membantu Anda mengonfigurasi akun untuk mengakses layanan mail:
- Untuk Office 365
- Untuk Gmail
Akses Layanan Mail dengan Token Akses
Contoh kode berikut menunjukkan cara menghubungkan ke layanan mail menggunakan token akses.
// Connecting to SMTP server
using (SmtpClient client = new SmtpClient(
"smtp.gmail.com",
587,
"user1@gmail.com",
"accessToken",
true,
SecurityOptions.SSLExplicit))
{
}
// Connecting to IMAP server
using (ImapClient client = new ImapClient(
"imap.gmail.com",
993,
"user1@gmail.com",
"accessToken",
true,
SecurityOptions.SSLImplicit))
{
}
// Connecting to POP3 server
using (Pop3Client client = new Pop3Client(
"pop.gmail.com",
995,
"user1@gmail.com",
"accessToken",
true,
SecurityOptions.Auto))
{
}
Akses Layanan Mail dengan Penyedia Token
Contoh kode berikut menunjukkan cara menghubungkan ke layanan mail menggunakan token provider. Built-in TokenProvider.Google factory digunakan untuk memperoleh provider yang secara otomatis memperbarui token akses menggunakan token refresh Google.
ITokenProvider tokenProvider = TokenProvider.Google.GetInstance(
"ClientId",
"ClientSecret",
"RefreshToken");
// Connecting to SMTP server
using (SmtpClient client = new SmtpClient(
"smtp.gmail.com",
587,
"user1@gmail.com",
tokenProvider,
SecurityOptions.SSLExplicit))
{
}
// Connecting to IMAP server
using (ImapClient client = new ImapClient(
"imap.gmail.com",
993,
"user1@gmail.com",
tokenProvider,
SecurityOptions.SSLImplicit))
{
}
// Connecting to POP3 server
using (Pop3Client client = new Pop3Client(
"pop.gmail.com",
995,
"user1@gmail.com",
tokenProvider,
SecurityOptions.Auto))
{
}
Implementasikan ITokenProvider Kustom untuk Office 365
Ketika token provider bawaan tidak tersedia untuk skenario Anda, Anda dapat mengimplementasikan ITokenProvider interface Anda sendiri. Contoh di bawah mengimplementasikan alur Azure Resource Owner Password Credential (ROPC) untuk memperoleh dan memperbarui token akses bagi layanan mail Office 365. The GetAccessToken metode menyimpan token dalam cache dan hanya meminta token baru dari server ketika token saat ini telah kedaluwarsa.
using JsonConvert = Newtonsoft.Json.JsonConvert;
using Aspose.Email.Clients;
using Aspose.Email.Common.Utils;
using Newtonsoft.Json;
using System;
using System.IO;
using System.Net;
using System.Text;
namespace TestNS
{
/// <summary>
/// Azure resource owner password credential (ROPC) token provider
/// https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth-ropc
/// https://portal.azure.com
/// https://developer.microsoft.com/en-us/graph/graph-explorer/#
/// token parser https://jwt.io
/// </summary>
internal class AzureROPCTokenProvider : ITokenProvider
{
private const string uriFormat = "https://login.microsoftonline.com/{0}/oauth2/v2.0/token";
private const string bodyFormat =
"client_id={0}" +
"&scope={1}" +
"&username={2}" +
"&password={3}" +
"&grant_type={4}";
private readonly string scope;
private const string grant_type = "password";
private readonly object tokenSyncObj = new object();
private OAuthToken token;
private readonly string tenant;
private readonly string clientId;
private readonly string clientSecret;
private readonly string userName;
private readonly string password;
/// <summary>
/// Initializes a new instance of the <see cref="AzureROPCTokenProvider"/> class
/// </summary>
public AzureROPCTokenProvider(
string tenant,
string clientId,
string clientSecret,
string userName,
string password,
string[] scopeAr)
{
this.tenant = tenant;
this.clientId = clientId;
this.clientSecret = clientSecret;
this.userName = userName;
this.password = password;
this.scope = string.Join(" ", scopeAr);
}
/// <summary>
/// Gets oAuth access token.
/// </summary>
/// <param name="ignoreExistingToken">
/// If ignoreExistingToken is true, requests a new token from the server. Otherwise the behaviour depends on whether the token exists or not.
/// If the token exists and its expiration date is not expired, returns the current token, otherwise requests a new token from the server.
/// </param>
/// <returns>Returns oAuth access token</returns>
public virtual OAuthToken GetAccessToken(bool ignoreExistingToken)
{
lock (tokenSyncObj)
{
if (this.token != null && !this.token.Expired && !ignoreExistingToken)
return this.token;
token = null;
string uri = string.Format(uriFormat, string.IsNullOrWhiteSpace(tenant) ? "common" : tenant);
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uri);
string body = string.Format(bodyFormat,
HttpUtility.UrlEncode(clientId),
HttpUtility.UrlEncode(scope),
HttpUtility.UrlEncode(userName),
HttpUtility.UrlEncode(password),
HttpUtility.UrlEncode(grant_type));
byte[] bytes = Encoding.ASCII.GetBytes(body);
request.Method = "POST";
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = bytes.Length;
using (Stream requestStream = request.GetRequestStream())
requestStream.Write(bytes, 0, bytes.Length);
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
StringBuilder responseText = new StringBuilder();
bytes = new byte[1024];
int read = 0;
using (Stream stream = response.GetResponseStream())
{
while ((read = stream.Read(bytes, 0, bytes.Length)) > 0)
responseText.Append(Encoding.ASCII.GetString(bytes, 0, read));
}
string jsonString = responseText.ToString();
AzureTokenResponse t = JsonConvert.DeserializeObject<AzureTokenResponse>(jsonString);
token = new OAuthToken(
t.access_token,
TokenType.AccessToken,
DateTime.Now.AddSeconds(t.expires_in));
return token;
}
}
/// <summary>
/// Gets oAuth access token.
/// If the token exists and its expiration date is not expired, returns the current token, otherwise requests a new token from the server.
/// </summary>
/// <returns>Returns oAuth access token</returns>
public OAuthToken GetAccessToken()
{
return GetAccessToken(false);
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public virtual void Dispose()
{
}
}
/// <summary>
/// A success response contains a JSON OAuth 2.0 response with the following parameters.
/// </summary>
public class AzureTokenResponse
{
/// <summary>
/// The requested access token. The calling web service can use this token to authenticate to the receiving web service.
/// </summary>
public string access_token { get; set; }
/// <summary>
/// Indicates the token type value. The only type that Azure AD supports is Bearer. For more information about bearer tokens,
/// see The OAuth 2.0 Authorization Framework: Bearer Token Usage (RFC 6750).
/// </summary>
public string token_type { get; set; }
/// <summary>
/// How long the access token is valid (in seconds).
/// </summary>
public int expires_in { get; set; }
/// <summary>
/// How long the access token is valid (in seconds).
/// </summary>
public int ext_expires_in { get; set; }
/// <summary>
/// The time when the access token expires.
/// The date is represented as the number of seconds from 1970-01-01T00:00:00Z UTC until the expiration time.
/// This value is used to determine the lifetime of cached tokens.
/// </summary>
public int expires_on { get; set; }
/// <summary>
/// The App ID URI of the receiving web service.
/// </summary>
public string resource { get; set; }
/// <summary>
/// If an access token was returned, this parameter lists the scopes the access token is valid for.
/// </summary>
public string scope { get; set; }
/// <summary>
/// Issued if the original scope parameter included the openid scope.
/// </summary>
public string id_token { get; set; }
/// <summary>
/// Issued if the original scope parameter included offline_access.
/// </summary>
public string refresh_token { get; set; }
}
}
Contoh kode berikut menunjukkan cara menghubungkan ke layanan Office 365 menggunakan token provider khusus yang diimplementasikan di atas. Instance provider yang sama dapat diteruskan ke klien SMTP, IMAP, POP3, dan EWS.
ITokenProvider tokenProvider = new AzureROPCTokenProvider(
"Tenant",
"ClientId",
"ClientSecret",
"EMail",
"Password",
scopes);
// Connecting to SMTP server
using (SmtpClient client = new SmtpClient(
"smtp.office365.com",
587,
"Test1@test.onmicrosoft.com",
tokenProvider,
SecurityOptions.SSLExplicit))
{
}
// Connecting to IMAP server
using (ImapClient client = new ImapClient(
"outlook.office365.com",
993,
"Test1@test.onmicrosoft.com",
tokenProvider,
SecurityOptions.SSLImplicit))
{
}
// Connecting to POP3 server
using (Pop3Client client = new Pop3Client(
"outlook.office365.com",
995,
"Test1@test.onmicrosoft.com",
tokenProvider,
SecurityOptions.Auto))
{
}
// Connecting to EWS server
const string mailboxUri = "https://outlook.office365.com/ews/exchange.asmx";
ICredentials credentials = new OAuthNetworkCredential(tokenProvider);
using (IEWSClient ewsClient = EWSClient.GetEWSClient(mailboxUri, credentials))
{
}