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Chilkat2-Python

Get GMail SMTP OAuth2 Access Token for Desktop App

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This example show how to obtain a Gmail SMTP OAuth2 access token from a desktop application or script, enabling the use of XOAUTH2 authentication.

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Chilkat2-Python
import sys
import chilkat2

success = False

# To further clarify, see OAuth 2.0 Authorization Flow

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"

# To use Gmail's OAuth2 for sending emails via the SMTP protocol, you need to request the https://mail.google.com/ scope. 
# See About GMail SMTP OAuth2 Scopes
oauth2.Scope = "https://mail.google.com/"

# Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
url = oauth2.StartAuth()
if (oauth2.LastMethodSuccess != True):
    print(oauth2.LastErrorText)
    sys.exit()

# Launch the default browser on the system and navigate to the url.
# The LaunchBrowser method was added in Chilkat v10.1.2.
success = oauth2.LaunchBrowser(url)
if (success == False):
    print(oauth2.LastErrorText)
    sys.exit()

# Wait for the user to approve or deny authorization in the browser.
numMsWaited = 0
while (numMsWaited < 90000) and (oauth2.AuthFlowState < 3) :
    oauth2.SleepMs(100)
    numMsWaited = numMsWaited + 100

# If the browser does not respond within the specified time, AuthFlowState will be:
# 
# 1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
# 2: Waiting for Final Response – The thread is awaiting the final access token response.
# In either case, cancel the background task initiated by StartAuth.

if (oauth2.AuthFlowState < 3):
    oauth2.Cancel()
    print("No response from the browser!")
    sys.exit()

# Check AuthFlowState to determine if authorization was granted, denied, or failed:
# 
# 3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
# 4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
# 5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

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/_gmailSmtp.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)