(PowerBuilder) Get Google Cloud Storage Access Token using Service Account JSON Private Key

Demonstrates how to get a Google Cloud Storage access token using a JSON service account private key. Obtaining an access token for a service account requires no user interaction (it does not require a browser, nor callback URI's, etc.).

When an access token expires, an application can be (and should be) designed to automatically fetch a new access token.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Fac
string ls_JsonKey
oleobject loo_GAuth
oleobject loo_TlsSock
integer li_Success
oleobject loo_SbToken

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

// First load the JSON key into a string.
loo_Fac = create oleobject
// Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")
if li_rc < 0 then
    destroy loo_Fac
    MessageBox("Error","Connecting to COM object failed")
    return
end if
ls_JsonKey = loo_Fac.ReadEntireTextFile("qa_data/googleApi/ChilkatCloud-13a07a2e8b3f.json","utf-8")
if loo_Fac.LastMethodSuccess <> 1 then
    Write-Debug loo_Fac.LastErrorText
    destroy loo_Fac
    return
end if

// A JSON private key should look something like this:

// 	{
// 	  "type": "service_account",
// 	  "project_id": "chilkattest-1350",
// 	  "private_key_id": "fa2e36ee26986eab628b59868af8bec1d1c64c38",
// 	  "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvgIjFa...28N64N2n1E4FYzBZjSdy\n-----END PRIVATE KEY-----\n",
// 	  "client_email": "598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a@developer.gserviceaccount.com",
// 	  "client_id": "598922945226-00rb0ppfg0snd9jo7bhvd4v17jtj2d3a.apps.googleusercontent.com",
// 	  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
// 	  "token_uri": "https://accounts.google.com/o/oauth2/token",
// 	  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
// 	  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/598922945226-00rb0ppfg0sndajo6bhvd4v17jtj2d3a%40developer.gserviceaccount.com"
// 	}

loo_GAuth = create oleobject
// Use "Chilkat_9_5_0.AuthGoogle" for versions of Chilkat < 10.0.0
li_rc = loo_GAuth.ConnectToNewObject("Chilkat.AuthGoogle")

loo_GAuth.JsonKey = ls_JsonKey

// Choose a scope.
loo_GAuth.Scope = "https://www.googleapis.com/auth/cloud-platform"

// Request an access token that is valid for this many seconds.
loo_GAuth.ExpireNumSeconds = 3600

// If the application is requesting delegated access:
// The email address of the user for which the application is requesting delegated access,
// then set the email address here. (Otherwise leave it empty.)
loo_GAuth.SubEmailAddress = ""

// Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
// The Chilkat socket object is used so that the connection can be established
// through proxies or an SSH tunnel if desired.
loo_TlsSock = create oleobject
// Use "Chilkat_9_5_0.Socket" for versions of Chilkat < 10.0.0
li_rc = loo_TlsSock.ConnectToNewObject("Chilkat.Socket")

li_Success = loo_TlsSock.Connect("www.googleapis.com",443,1,5000)
if li_Success <> 1 then
    Write-Debug loo_TlsSock.LastErrorText
    destroy loo_Fac
    destroy loo_GAuth
    destroy loo_TlsSock
    return
end if

// Send the request to obtain the access token.
li_Success = loo_GAuth.ObtainAccessToken(loo_TlsSock)
if li_Success <> 1 then
    Write-Debug loo_GAuth.LastErrorText
    destroy loo_Fac
    destroy loo_GAuth
    destroy loo_TlsSock
    return
end if

// Examine the access token:
Write-Debug "Access Token: " + loo_GAuth.AccessToken

// We're going to save this access token to a file to be used
// by other examples.
loo_SbToken = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbToken.ConnectToNewObject("Chilkat.StringBuilder")

loo_SbToken.Append(loo_GAuth.AccessToken)
loo_SbToken.WriteFile("qa_data/tokens/googleCloudStorageAccessToken.txt","utf-8",0)


destroy loo_Fac
destroy loo_GAuth
destroy loo_TlsSock
destroy loo_SbToken