Zig

IMAP Auto-Refresh Office365 Access Token

See more Office365 Examples

Demonstrates how to automatically recover from an expired access token when OAuth2 authentication fails in the IMAP protocol. If the server responds with "NO AUTHENTICATE failed.", then we refresh the access token and retry. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    var success: bool = false;

    // An Office365 OAuth2 access token must first be obtained prior
    // to running this code.

    // Getting the OAuth2 access token for the 1st time requires the O365 account owner's
    // interactive authorizaition via a web browser.  Afterwards, the access token
    // can be repeatedly refreshed automatically.

    // See the following examples for getting and refreshing an OAuth2 access token

    // Get Office365 SMTP/IMAP/POP3 OAuth2 Access Token
    // Refresh Office365 SMTP/IMAP/POP3 OAuth2 Access Token

    // First get our previously obtained OAuth2 access token.
    const json_token = try chilkat.JsonObject.init();
    defer json_token.deinit();
    success = if (json_token.loadFile("qa_data/tokens/office365.json")) true else |_| false;
    if (!success) {
        std.debug.print("Failed to open the office365 OAuth JSON file.\n", .{});
        return;
    }

    const imap = try chilkat.Imap.init();
    defer imap.deinit();

    imap.setSsl(true);
    imap.setPort(993);

    // Connect to the Office365 IMAP server.
    success = if (imap.connect("outlook.office365.com")) true else |_| false;
    if (!success) {
        std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
        return;
    }

    // Use OAuth2 authentication.
    imap.setAuthMethod("XOAUTH2");

    // Login using our username (i.e. email address) and the access token for the password.
    success = if (imap.login("OFFICE365_EMAIL_ADDRESS", try json_token.stringOf(alloc, "access_token"))) true else |_| false;
    if (!success) {
        const login_last_error_text = try imap.getLastErrorText(alloc);

        // If we're still connected to the mail server, then it means the server sent a non-success response,
        // Such as:  NO AUTHENTICATE failed.
        if (imap.isConnected()) {
            // Refresh the OAuth2 access token, and if successful, save the new (refreshed) access token and try authenticating again.
            const oauth2 = try chilkat.OAuth2.init();
            defer oauth2.deinit();

            // Use your actual Directory (tenant) ID instead of "112d7ed6-71bf-4eba-a866-738364321bfc"
            oauth2.setTokenEndpoint("https://login.microsoftonline.com/112d7ed6-71bf-4eba-a866-738364321bfc/oauth2/v2.0/token");

            // Replace these with your Azure App Registration's actual values.
            oauth2.setClientId("CLIENT_ID");
            oauth2.setClientSecret("CLIENT_SECRET");

            // Get the "refresh_token"
            oauth2.setRefreshToken(try json_token.stringOf(alloc, "refresh_token"));

            // Send the HTTP POST to refresh the access token..
            oauth2.refreshAccessToken() catch {
                std.debug.print("{s}\n", .{try oauth2.getLastErrorText(alloc)});
                return;
            };

            std.debug.print("New access token: {s}\n", .{try oauth2.getAccessToken(alloc)});
            std.debug.print("New refresh token: {s}\n", .{try oauth2.getRefreshToken(alloc)});

            // Update the JSON with the new tokens.
            json_token.updateString("access_token", try oauth2.getAccessToken(alloc)) catch {};
            json_token.updateString("refresh_token", try oauth2.getRefreshToken(alloc)) catch {};

            // Save the new JSON access token response to a file.
            const sb_json = try chilkat.StringBuilder.init();
            defer sb_json.deinit();
            json_token.setEmitCompact(false);
            json_token.emitSb(sb_json) catch {};
            sb_json.writeFile("qa_data/tokens/office365.json", "utf-8", false) catch {};

            std.debug.print("New Access Token = {s}\n", .{try oauth2.getAccessToken(alloc)});

            // Retry the login.
            imap.login("OFFICE365_EMAIL_ADDRESS", try json_token.stringOf(alloc, "access_token")) catch {
                std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
                return;
            };
        } else {
            // Show the last error text for the call to Login
            std.debug.print("{s}\n", .{login_last_error_text});
            return;
        }
    } else {
        std.debug.print("O365 OAuth authentication is successful.\n", .{});
    }

    // Do something...
    imap.selectMailbox("Inbox") catch {
        std.debug.print("{s}\n", .{try imap.getLastErrorText(alloc)});
        return;
    };

    // Your application can continue to do other things in the IMAP session....

    // When finished, logout and close the connection.
    success = if (imap.logout()) true else |_| false;
    success = if (imap.disconnect()) true else |_| false;

    std.debug.print("Finished.\n", .{});
}