(Tcl) OAuth2 using an HTTP Proxy (for a Desktop Application)

Demonstrates how to send OAuth2 communications through an HTTP proxy for a desktop application. The technique is the same for all OAuth2 applications. This one happens to demonstrate for Microsoft Graph.

Note: This example requires Chilkat v10.1.2 or greater.

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load ./chilkat.dll

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

# To use an HTTP proxy with OAuth2, create a Chilkat socket object and specify the details.
set socket [new_CkSocket]

# Use your HTTP proxy server domain or IP address.
CkSocket_put_HttpProxyHostname $socket "myproxyserver.com"
# Change this to the listening port of your HTTP proxy server (if necessary)
CkSocket_put_HttpProxyPort $socket 808
# Specify login/password if needed.
CkSocket_put_HttpProxyUsername $socket "myProxyLogin"
CkSocket_put_HttpProxyPassword $socket "myProxyPassword"
CkSocket_put_HttpProxyForHttp $socket 1

set oauth2 [new_CkOAuth2]

# We don't need to connect the socket beforehand.
# Just tell oauth2 to use the socket which has the HTTP proxy properties.
set success [CkOAuth2_UseConnection $oauth2 $socket]

# This should be the port in the localhost callback URL for your app.  
# The callback URL would look like "http://localhost:3017/" if the port number is 3017.
CkOAuth2_put_ListenPort $oauth2 3017

CkOAuth2_put_AuthorizationEndpoint $oauth2 "https://login.microsoftonline.com/common/oauth2/v2.0/authorize"
CkOAuth2_put_TokenEndpoint $oauth2 "https://login.microsoftonline.com/common/oauth2/v2.0/token"

# Replace these with actual values.
CkOAuth2_put_ClientId $oauth2 "MICROSOFT-GRAPH-CLIENT-ID"
# This is your app password:
CkOAuth2_put_ClientSecret $oauth2 "MICROSOFT-GRAPH-CLIENT-SECRET"

CkOAuth2_put_CodeChallenge $oauth2 0
# Provide a SPACE separated list of scopes.
# See https://developer.microsoft.com/en-us/graph/docs/authorization/permission_scopes 

# Important: To get a refresh token in the final response, you have to ask for "offline_access" scope
CkOAuth2_put_Scope $oauth2 "openid profile offline_access user.readwrite mail.readwrite mail.send files.readwrite"

# Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
set url [CkOAuth2_startAuth $oauth2]
if {[CkOAuth2_get_LastMethodSuccess $oauth2] != 1} then {
    puts [CkOAuth2_lastErrorText $oauth2]
    delete_CkSocket $socket
    delete_CkOAuth2 $oauth2
    exit
}

puts "url = $url"

# Launch the default browser on the system and navigate to the url.
# The LaunchBrowser method was added in Chilkat v10.1.2.
set success [CkOAuth2_LaunchBrowser $oauth2 $url]
if {$success == 0} then {
    puts [CkOAuth2_lastErrorText $oauth2]
    delete_CkSocket $socket
    delete_CkOAuth2 $oauth2
    exit
}

# Wait for the user to approve or deny authorization in the browser.
set numMsWaited 0
while {expr [$numMsWaited < 90000]  &&  [[CkOAuth2_get_AuthFlowState $oauth2] < 3]} {
    CkOAuth2_SleepMs $oauth2 100
    set numMsWaited [expr $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 {[CkOAuth2_get_AuthFlowState $oauth2] < 3} then {
    CkOAuth2_Cancel $oauth2
    puts "No response from the browser!"
    delete_CkSocket $socket
    delete_CkOAuth2 $oauth2
    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 {[CkOAuth2_get_AuthFlowState $oauth2] == 5} then {
    puts "OAuth2 failed to complete."
    puts [CkOAuth2_failureInfo $oauth2]
    delete_CkSocket $socket
    delete_CkOAuth2 $oauth2
    exit
}

if {[CkOAuth2_get_AuthFlowState $oauth2] == 4} then {
    puts "OAuth2 authorization was denied."
    puts [CkOAuth2_accessTokenResponse $oauth2]
    delete_CkSocket $socket
    delete_CkOAuth2 $oauth2
    exit
}

if {[CkOAuth2_get_AuthFlowState $oauth2] != 3} then {
    puts "Unexpected AuthFlowState:[CkOAuth2_get_AuthFlowState $oauth2]"
    delete_CkSocket $socket
    delete_CkOAuth2 $oauth2
    exit
}

puts "OAuth2 authorization granted!"
puts "Access Token = [CkOAuth2_accessToken $oauth2]"

# Get the full JSON response:
set json [new_CkJsonObject]

CkJsonObject_Load $json [CkOAuth2_accessTokenResponse $oauth2]
CkJsonObject_put_EmitCompact $json 0

# The JSON response looks like this:

# {
#   "token_type": "Bearer",
#   "scope": "User.Read Mail.ReadWrite Mail.Send",
#   "expires_in": 3600,
#   "ext_expires_in": 0,
#   "access_token": "EwBAA8l6B...",
#   "refresh_token": "MCRMdbe...",
#   "id_token": "eyJ0eXA..."
# }

# If an "expires_on" member does not exist, then add the JSON member by
# getting the current system date/time and adding the "expires_in" seconds.
# This way we'll know when the token expires.
if {[CkJsonObject_HasMember $json "expires_on"] != 1} then {
    set dtExpire [new_CkDateTime]

    CkDateTime_SetFromCurrentSystemTime $dtExpire
    CkDateTime_AddSeconds $dtExpire [CkJsonObject_IntOf $json "expires_in"]
    CkJsonObject_AppendString $json "expires_on" [CkDateTime_getAsUnixTimeStr $dtExpire 0]
}

puts [CkJsonObject_emit $json]

# Save the JSON to a file for future requests.
set fac [new_CkFileAccess]

CkFileAccess_WriteEntireTextFile $fac "qa_data/tokens/microsoftGraph.json" [CkJsonObject_emit $json] "utf-8" 0

delete_CkSocket $socket
delete_CkOAuth2 $oauth2
delete_CkJsonObject $json
delete_CkDateTime $dtExpire
delete_CkFileAccess $fac