(Visual Basic 6.0) Get ETK Public Key (api-acpt.ehealth.fgov.be)

See more Belgian eHealth Platform Examples

The following URL returns JSON, which contains a PKCS7 signed data:

https://api-acpt.ehealth.fgov.be/etee/v1/etks?identifier=12345678901&type=SSIN

This example extracts the signed data, validates it, and then extracts the public key from the certificate (obtained from signed content in the PKCS7)

Note: The URL above uses "12345678901" which is not valid. You should replace it with a valid number.

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

Dim http As New ChilkatHttp

Dim jsonStr As String
jsonStr = http.QuickGetStr("https://api-acpt.ehealth.fgov.be/etee/v1/etks?identifier=12345678901&type=SSIN")
If (http.LastMethodSuccess = 0) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

Debug.Print jsonStr

' The JSON contains something like this:

' [
'     {
'         "key": {
'             "applicationIdentifier": "",
'             "ssin": "12345678901"
'         },
'         "value": "MIAGCSq....AAAAAAAA=="
'     }
' ]

' Note: The above is a JSON array (not a JSON object)
' It should be loaded into a Chilkat JSON array.
Dim jarr As New ChilkatJsonArray
Dim success As Long
success = jarr.Load(jsonStr)
If (success = 0) Then
    Debug.Print "Failed to load JSON."
    Exit Sub
End If

Dim json As ChilkatJsonObject
Set json = jarr.ObjectAt(0)
Dim bdPkcs7 As New ChilkatBinData
success = bdPkcs7.AppendEncoded(json.StringOf("value"),"base64")

' Let's verify the PKCS7, and then examine the signing cert,
' and get the signing cert's public key.
Dim crypt As New ChilkatCrypt2

' Validate the signedData PKCS7, and replace the contents of bdPkcs7 with the extracted signed content.
success = crypt.OpaqueVerifyBd(bdPkcs7)
If (success = 0) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

' The signed content is the DER of a certificate.
' In other words, bdPkcs7 now contains a certificate.
Dim cert As New ChilkatCert
success = cert.LoadFromBd(bdPkcs7)
If (success = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' Show some certificate information:
Debug.Print "Subject: " & cert.SubjectDN
Debug.Print "Serial: " & cert.SerialNumber
Debug.Print "Issuer: " & cert.IssuerDN

' Let's get the cert's public key...
Dim pubKey As PublicKey
Set pubKey = cert.ExportPublicKey()
If (cert.LastMethodSuccess = 0) Then
    Debug.Print cert.LastErrorText
    Exit Sub
End If

' OK, you now have the public key and can do whatever is needed..
Debug.Print pubKey.KeyType
Debug.Print pubKey.KeySize