Chilkat2-Python

Get POP3 GMail OAuth2 Access Token for Desktop App

See more GMail SMTP/IMAP/POP Examples

Demonstrates how to get a POP3 GMail OAuth2 access token from a desktop application or script.

This example requires a browser window to be displayed to allow the GMail account owner to authorize the access. The code for displaying the web browser is omitted. Suggestions for a few programming languages are provided in code comments. To complete this example, you will need to find out how to display a web browser and navigate to the URL returned by the call to oauth2.StartAuth.

Chilkat2-Python

import sys
import chilkat2

success = False

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

oauth2 = chilkat2.OAuth2()

# For Google OAuth2, set the listen port equal to the port used
# in the Authorized Redirect URL for the Client ID.
# For example, in this case the Authorized Redirect URL would be http://localhost:55568/
# Your app should choose a port not likely not used by any other application.
oauth2.ListenPort = 55568

oauth2.AuthorizationEndpoint = "https://accounts.google.com/o/oauth2/v2/auth"
oauth2.TokenEndpoint = "https://www.googleapis.com/oauth2/v4/token"

# Replace these with actual values.
oauth2.ClientId = "GOOGLE-CLIENT-ID"
oauth2.ClientSecret = "GOOGLE-CLIENT-SECRET"

oauth2.CodeChallenge = True
oauth2.CodeChallengeMethod = "S256"

# See https://developers.google.com/gmail/api/auth/scopes for a list of GMail scopes.
# This is the full-permissions scope for GMail, which is sufficient for all POP3 operations to pop.gmail.com
oauth2.Scope = "https://mail.google.com/"

# Important note about GMail scope for sending email:
# If the SMTP protocol is used for sending, then the full GMail scope is required: "https://mail.google.com/"
# Here is an example that sends GMail via the SMTP protocol:  Send GMail using SMTP
# If the GMail REST API is used, then the more restrictive Gmail scope can be used:  "https://www.googleapis.com/auth/gmail.send"
# Here is an example that sends GMail using the GMail REST API: Send GMail using REST API

# Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
url = oauth2.StartAuth()
if (oauth2.LastMethodSuccess == False):
    print(oauth2.LastErrorText)
    sys.exit()

# Launch the system's default browser navigated to the URL.
success = oauth2.LaunchBrowser(url)
if (success == False):
    print(oauth2.LastErrorText)
    sys.exit()

# Now wait for the authorization.
# We'll wait for a max of 30 seconds.
numMsWaited = 0
while (numMsWaited < 30000) and (oauth2.AuthFlowState < 3) :
    oauth2.SleepMs(100)
    numMsWaited = numMsWaited + 100

# If there was no response from the browser within 30 seconds, then 
# the AuthFlowState will be equal to 1 or 2.
# 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
# 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
# In that case, cancel the background task started in the call to StartAuth.
if (oauth2.AuthFlowState < 3):
    oauth2.Cancel()
    print("No response from the browser!")
    sys.exit()

# Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
# The possible AuthFlowState values are:
# 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
# 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
# 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
if (oauth2.AuthFlowState == 5):
    print("OAuth2 failed to complete.")
    print(oauth2.FailureInfo)
    sys.exit()

if (oauth2.AuthFlowState == 4):
    print("OAuth2 authorization was denied.")
    print(oauth2.AccessTokenResponse)
    sys.exit()

if (oauth2.AuthFlowState != 3):
    print("Unexpected AuthFlowState:" + str(oauth2.AuthFlowState))
    sys.exit()

# Save the full JSON access token response to a file.
sbJson = chilkat2.StringBuilder()
sbJson.Append(oauth2.AccessTokenResponse)
sbJson.WriteFile("qa_data/tokens/gmail_pop3.json","utf-8",False)

# The saved JSON response looks like this:

# 	{
# 	 "access_token": "ya39.Ci-XA_C5bGgRDC3UaD-h0_NeL-DVIQnI2gHtBBBHkZzrwlARkwX6R3O0PCDEzRlfaQ",
# 	 "token_type": "Bearer",
# 	 "expires_in": 3600,
# 	 "refresh_token": "1/r_2c_7jddspcdfesrrfKqfXtqo08D6Q-gUU0DsdfVMsx0c"
# 	}
# 
print("OAuth2 authorization granted!")
print("Access Token = " + oauth2.AccessToken)