OAuth2 with gmail account using MailKit do not work on Azure WebJobs

Question

The code works fine on my local machine, but I get an "Access Denied" running it on Azure WebJobs

const string GMailAccount = "[email protected]";

var clientSecrets = new ClientSecrets
{
    ClientId = "XXX.apps.googleusercontent.com",
    ClientSecret = "XXX"
};

var codeFlow = new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer
{
    DataStore = new FileDataStore("CredentialCacheFolder", false),
    Scopes = new[] { "https://mail.google.com/" },
    ClientSecrets = clientSecrets
});

var codeReceiver = new LocalServerCodeReceiver();
var authCode = new AuthorizationCodeInstalledApp(codeFlow, codeReceiver);

var credential = await authCode.AuthorizeAsync(GMailAccount, System.Threading.CancellationToken.None);

if (credential.Token.IsExpired(Google.Apis.Util.SystemClock.Default)) await credential.RefreshTokenAsync(System.Threading.CancellationToken.None);

var oauth2 = new MailKit.Security.SaslMechanismOAuth2(credential.UserId, credential.Token.AccessToken);

using (var mailClient = new ImapClient())
{
    await mailClient.ConnectAsync("imap.gmail.com", 993, MailKit.Security.SecureSocketOptions.SslOnConnect);
    await mailClient.AuthenticateAsync(oauth2);
    var inbox = mailClient.Inbox;
    inbox.Open(FolderAccess.ReadWrite);
    var items = inbox.Fetch(0, -1, MessageSummaryItems.UniqueId | MessageSummaryItems.Size | MessageSummaryItems.Flags);
    // iterate over all of the messages and fetch them by UID

    foreach (var item in items)
    {
        var uid = item.UniqueId;
        var myMessage = inbox.GetMessage(uid);
        Console.WriteLine(uid);
    }
        await mailClient.DisconnectAsync(true);
}

Azure WebJob log :

exception.System.Net.HttpListenerException (5
 ): Access is denied
at Google.Apis.Auth.OAuth2.AuthorizationCodeInstalledApp.AuthorizeAsync(String userId, CancellationToken taskCancellationToken)

Answer 1

The problem is that you are using the code for desktop apps instead of web apps (see your call to AuthorizationInstalledApp).

That call expects to be able to spawn a desktop browser window which obviously won’t work for a web app running on a headless server.

If you are using ASP.NET, someone just recently sent me a sample to include in MailKit’s GMailOAuth2.md file.

Answer 2

I'm not sure about your overall algorithm. But you can filter out the None values simply by assigning the result of freq to a variable before printing it. Then you can check if it's not None.

for a in var1_bin:
    for key in range(256):
        decoded = ''.join(chr(b ^ key) for b in a)
        decoded_freq = freq(decoded, ascii_letters)
        if decoded_freq:
            print(key, decoded_freq)