Visual FoxPro

Get Firebase Access Token from JSON Service Account Private Key

See more Firebase Examples

Demonstrates how to get a Firebase access token using a JSON service account private key. Your Firebase service account can be used to authenticate multiple Firebase features, such as Database, Storage and Auth, programmatically.

A Firebase JSON service account private key can be created in the Firebase settings/admin portion of the console.firebase.google.com site as shown here:

Scroll down to see the example code...

Visual FoxPro

LOCAL lnSuccess
LOCAL loFac
LOCAL lcJsonKey
LOCAL loGAuth
LOCAL loTlsSock

lnSuccess = 0

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

*  First load the Firebase JSON private key into a string.
loFac = CreateObject('Chilkat.FileAccess')
lcJsonKey = loFac.ReadEntireTextFile("qa_data/firebase/firebase-chilkat-firebase-adminsdk-n28n4-1b664ee163.json","utf-8")
IF (loFac.LastMethodSuccess <> 1) THEN
    ? loFac.LastErrorText
    RELEASE loFac
    CANCEL
ENDIF

*  A Firebase JSON private key should look something like this:

*  { 
*    "type": "service_account",
*    "project_id": "firebase-chilkat",
*    "private_key_id": "1c664ee164907413c91ddefcf5b765ecba8779e2",
*    "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBA ... Ya2UZii/lXn73/ZOK8=\n-----END PRIVATE KEY-----\n",
*    "client_email": "firebase-adminsdk-n28n4@firebase-chilkat.iam.gserviceaccount.com",
*    "client_id": "134846322329335418431",
*    "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/firebase-adminsdk-n28n4%40firebase-chilkat.iam.gserviceaccount.com"
*  } 
*  

loGAuth = CreateObject('Chilkat.AuthGoogle')
loGAuth.JsonKey = lcJsonKey

*  Choose a scope.
*  The scope could be "https://www.googleapis.com/auth/firebase.database"
*  or a space-delimited list of scopes:
*  "https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email"

loGAuth.Scope = "https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email"

*  Request an access token that is valid for this many seconds.
loGAuth.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.)
loGAuth.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.
loTlsSock = CreateObject('Chilkat.Socket')
lnSuccess = loTlsSock.Connect("www.googleapis.com",443,1,5000)
IF (lnSuccess <> 1) THEN
    ? loTlsSock.LastErrorText
    RELEASE loFac
    RELEASE loGAuth
    RELEASE loTlsSock
    CANCEL
ENDIF

*  Send the request to obtain the access token.
lnSuccess = loGAuth.ObtainAccessToken(loTlsSock)
IF (lnSuccess <> 1) THEN
    ? loGAuth.LastErrorText
    RELEASE loFac
    RELEASE loGAuth
    RELEASE loTlsSock
    CANCEL
ENDIF

*  Examine the access token:
? "Firebase Access Token: " + loGAuth.AccessToken

*  Save the token to a file (or wherever desired).  This token is valid for 1 hour.
loFac.WriteEntireTextFile("qa_data/tokens/firebaseToken.txt",loGAuth.AccessToken,"utf-8",0)

RELEASE loFac
RELEASE loGAuth
RELEASE loTlsSock