(Visual Basic 6.0) RSAP Union API - Get OAuth2 Access Token

Demonstrates how to get an OAuth2 access token for the RSAP Union API. Note: This uses the client credentials flow, which does NOT require an interactive engagement using a browser.

For more information, see https://app.swaggerhub.com/apis-docs/pderas/RSAP/2.0.1#/Authentication/getOauthToken

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

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

Dim http As New ChilkatHttp
Dim success As Long

' The following JSON is sent in the request body.

' {
'   "grant_type": "client_credentials",
'   "client_id": 1234,
'   "client_secret": "23456abcde"
' }

Dim json As New ChilkatJsonObject
success = json.UpdateString("grant_type","client_credentials")
success = json.UpdateInt("client_id",1234)
success = json.UpdateString("client_secret","23456abcde")

http.SetRequestHeader "Content-type","application/json"

' Add the client certificate TLS authentication.
Dim cert As New ChilkatCert
success = cert.LoadFromFile("qa_data/certs_and_keys/union_client_certificate.crt")
If (success = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

Dim privKey As New PrivateKey
success = privKey.LoadAnyFormatFile("qa_data/certs_and_keys/union_client_certificate.nopass.key","")
If (success = 0) Then
    Debug.Print privKey.LastErrorText
    Exit Sub
End If

' Associate the private key with the cert.
' This will fail if the private key is not actually the correct one that corresponds to the public key stored within the cert.
success = cert.SetPrivateKey(privKey)
If (success = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Tell HTTP to use the cert for client TLS certificate authentication.
success = http.SetSslClientCert(cert)
If (success = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

Dim resp As ChilkatHttpResponse
Set resp = http.PostJson3("https://api-test.rsap.ca/oauth/token","application/json",json)
If (http.LastMethodSuccess = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

Dim sbResponseBody As New ChilkatStringBuilder
success = resp.GetBodySb(sbResponseBody)
Dim jResp As New ChilkatJsonObject
success = jResp.LoadSb(sbResponseBody)
jResp.EmitCompact = 0

Debug.Print "Response Body:"
Debug.Print jResp.Emit()

Dim respStatusCode As Long
respStatusCode = resp.StatusCode
Debug.Print "Response Status Code = " & respStatusCode
If (respStatusCode >= 400) Then
    Debug.Print "Response Header:"
    Debug.Print resp.Header
    Debug.Print "Failed."

    Exit Sub
End If

' Sample JSON response:
' (Sample code for parsing the JSON response is shown below)

' {
'   "token_type": "Bearer",
'   "expires_in": 3600,
'   "access_token": "eyJ0eXAi...LnE"
' }

' This token expires in 1 hour.  Your application could re-use the same token for up to an hour,
' or it can simply get a new access token before each request (if you're not doing too many requests).
success = jResp.WriteFile("qa_data/tokens/rsapToken.json")