(Visual Basic 6.0) Uni Economy API Client Credentials Flow

Demonstrates how to do OAuth 2.0 using the client credentials flow for the Uni Economy API. (This means that the server can authenticate against the identity server without human interaction.)

For more information, see https://developer.unieconomy.no/wiki/introduction/getting-started/server-application

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

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

' Step 1 ------------------------------------------------------------------------------------------
' First create a client token...

Dim cert As New ChilkatCert
cert.VerboseLogging = 1
' Note: .pfx and .p12 files are identical.  The only difference is the file extension.
' Also, if your .p12 password is longer than 64 chars, you'll need Chilkat v9.5.0.83 or later.
' To shorten the password, import your .p12 onto your Windows computer by double-clicking on the .p12 file,
' make sure when importing that keys are exportable, then re-export with private keys to a .pfx with a new password.
Dim success As Long
success = cert.LoadPfxFile("qa_data/pfx/UniCert_Norge_Test_secret.pfx","secret")
If (success = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

Dim privKey As PrivateKey
Set privKey = cert.ExportPrivateKey()
If (cert.LastMethodSuccess = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

Dim jwt As New ChilkatJwt

' Build the JOSE header
Dim jose As New ChilkatJsonObject
' Use RS256.  Pass the string "RS384" or "RS512" to use RSA with SHA-384 or SHA-512.
success = jose.AppendString("alg","RS256")
success = jose.AppendString("typ","JWT")

' Now build the JWT claims (also known as the payload)

' Our JWT claims will contain members as shown here:
' {
'   "jti": "ad612fce-3e71-4f6a-8af1-7eb0414b4eea",  <-- generated unique global identifier
'   "sub": "99999999-aaaa-bbbb-cccc-ddddeeeeffff",  <-- This is the clientId
'   "iat": 1588102982,  <-- These are date/time values.
'   "nbf": 1588102982,
'   "exp": 1588103042,
'   "iss": " 99999999-aaaa-bbbb-cccc-ddddeeeeffff",
'   "aud": "https://test-login.unieconomy.no/connect/token"
' }

' Use your own client ID.
Dim myClientId As String
myClientId = "99999999-aaaa-bbbb-cccc-ddddeeeeffff"

Dim claims As New ChilkatJsonObject
Dim crypt As New ChilkatCrypt2
success = claims.AppendString("jti",crypt.GenerateUuid())
success = claims.AppendString("sub",myClientId)

' Set the timestamp of when the JWT was created to now minus 60 seconds
Dim curDateTime As Long
curDateTime = jwt.GenNumericDate(-60)
success = claims.AddIntAt(-1,"iat",curDateTime)

' Set the "not process before" timestamp to now minus 60 seconds
success = claims.AddIntAt(-1,"nbf",curDateTime)

' Set the timestamp defining an expiration time (end time) for the token
' to be now + 1 hour (3600 seconds)
success = claims.AddIntAt(-1,"exp",curDateTime + 3600)

success = claims.AppendString("iss",myClientId)
success = claims.AppendString("aud","https://test-login.unieconomy.no/connect/token")

' Produce the smallest possible JWT:
jwt.AutoCompact = 1

' Create the JWT token.  This is where the RSA signature is created.
Dim jwt_token As String
jwt_token = jwt.CreateJwtPk(jose.Emit(),claims.Emit(),privKey)

Debug.Print jwt_token

' Step 2 ------------------------------------------------------------------------------------------
Dim http As New ChilkatHttp

' Fetch the discovery document...
Dim resp As ChilkatHttpResponse
Set resp = http.QuickRequest("GET","https://test-login.unieconomy.no/.well-known/openid-configuration")
If (http.LastMethodSuccess <> 1) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

If (resp.StatusCode <> 200) Then
    Debug.Print "Received response status code " & resp.StatusCode
    Debug.Print "Response body containing error text or JSON:"
    Debug.Print resp.BodyStr

    Exit Sub
End If

Dim json As New ChilkatJsonObject
success = json.Load(resp.BodyStr)

json.EmitCompact = 0
Debug.Print json.Emit()

' We have the discovery document, which contains something like this:

' You can use this online tool to generate parsing code from sample JSON: 
' Generate Parsing Code from JSON

' {
'   "issuer": "https://test-login.unieconomy.no",
'   "jwks_uri": "https://test-login.unieconomy.no/.well-known/openid-configuration/jwks",
'   "authorization_endpoint": "https://test-login.unieconomy.no/connect/authorize",
'   "token_endpoint": "https://test-login.unieconomy.no/connect/token",
'   "userinfo_endpoint": "https://test-login.unieconomy.no/connect/userinfo",
'   "end_session_endpoint": "https://test-login.unieconomy.no/connect/endsession",
'   "check_session_iframe": "https://test-login.unieconomy.no/connect/checksession",
'   "revocation_endpoint": "https://test-login.unieconomy.no/connect/revocation",
'   "introspection_endpoint": "https://test-login.unieconomy.no/connect/introspect",
'   "device_authorization_endpoint": "https://test-login.unieconomy.no/connect/deviceauthorization",
'   "frontchannel_logout_supported": true,
'   "frontchannel_logout_session_supported": true,
'   "backchannel_logout_supported": true,
'   "backchannel_logout_session_supported": true,
'   "scopes_supported": [
'     "openid",
'     "profile",
'     "email",
'     "offline_access",
'     "AppFramework.All",
'     "AppFramework",
'     "AppFramework.Sales",
'     "IdentityAPI",
'     "widgetApi",
'     "TestScope.test",
'     "TestScope.Cars",
'     "HaglandAPI",
'     "LicenseAdmin",
'     "LicenseAdmin.Product.Read",
'     "SoftRig.Product.Write",
'     "TestAPI.test",
'     "offline_access"
'   ],
'   "claims_supported": [
'     "sub",
'     "updated_at",
'     "name",
'     "family_name",
'     "given_name",
'     "middle_name",
'     "nickname",
'     "preferred_username",
'     "picture",
'     "website",
'     "gender",
'     "birthdate",
'     "zoneinfo",
'     "locale",
'     "profile",
'     "email",
'     "email_verified"
'   ],
'   "grant_types_supported": [
'     "authorization_code",
'     "client_credentials",
'     "refresh_token",
'     "implicit",
'     "password",
'     "urn:ietf:params:oauth:grant-type:device_code",
'     "delegation"
'   ],
'   "response_types_supported": [
'     "code",
'     "token",
'     "id_token",
'     "id_token token",
'     "code id_token",
'     "code token",
'     "code id_token token"
'   ],
'   "response_modes_supported": [
'     "form_post",
'     "query",
'     "fragment"
'   ],
'   "token_endpoint_auth_methods_supported": [
'     "client_secret_basic",
'     "client_secret_post",
'     "private_key_jwt",
'     "private_key_jwt"
'   ],
'   "id_token_signing_alg_values_supported": [
'     "RS256"
'   ],
'   "subject_types_supported": [
'     "public"
'   ],
'   "code_challenge_methods_supported": [
'     "plain",
'     "S256"
'   ],
'   "request_parameter_supported": true
' }

' ------------------------------------------------------
' The next steps are to (1) get the token_endpoint,
' and (2) verify that the client_credentials grant type is supported.

Dim tokenEndpoint As String
tokenEndpoint = json.StringOf("token_endpoint")

Dim grantTypes As ChilkatJsonArray
Set grantTypes = json.ArrayOf("grant_types_supported")
Dim clientCredentialsIdx As Long
clientCredentialsIdx = grantTypes.FindString("client_credentials",1)

' If clientCredentialsIdx is less then zero (-1) then the "client_credentials" string was not found.
If (clientCredentialsIdx < 0) Then
    Debug.Print "The client credentials grant type is not supported."
    Exit Sub
End If

' ------------------------------------------------------
' Request the access token using our Client ID and JWT

Dim req As New ChilkatHttpRequest
req.HttpVerb = "POST"
req.AddParam "client_id",myClientId
req.AddParam "scope","AppFramework.Sales"
req.AddParam "grant_type","client_credentials"
req.AddParam "client_assertion_type","urn:ietf:params:oauth:client-assertion-type:jwt-bearer"
req.AddParam "client_assertion",jwt_token

Set resp = http.PostUrlEncoded(tokenEndpoint,req)
If (http.LastMethodSuccess = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

' Make sure we got a 200 response status code, otherwise it's an error.
If (resp.StatusCode <> 200) Then
    Debug.Print "POST to token endpoint failed."
    Debug.Print "Received response status code " & resp.StatusCode
    Debug.Print "Response body containing error text or JSON:"
    Debug.Print resp.BodyStr

    Exit Sub
End If

success = json.Load(resp.BodyStr)

Debug.Print json.Emit()

' The JSON response will look like this:

' {
'   "access_token": "...",
'   "expires_in": 3600,
'   "token_type": "Bearer",
'   "scope": "AppFramework.Sales"
' }

' Get the access token:
Dim accessToken As String
accessToken = json.StringOf("access_token")
Debug.Print "accessToken = " & accessToken

' ------------------------------------------------------
' Use the access token in a request.
' We'll just send a GET request to  https://test.unieconomy.no/api/init/companies

' Tell the http object to use the OAuth2 access token in the "Authorization: Bearer ..." header.
http.AuthToken = accessToken

Dim sbResponse As New ChilkatStringBuilder
success = http.QuickGetSb("https://test.unieconomy.no/api/init/companies",sbResponse)
If (success = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

' Examine the response status code.
If (http.LastStatus <> 200) Then
    Debug.Print sbResponse.GetAsString()
    Debug.Print "response status: " & http.LastStatus
    Debug.Print "Received error response."
    Exit Sub
End If

success = json.LoadSb(sbResponse)
Debug.Print json.Emit()

Debug.Print "Success."