B4X Requires Chilkat v11.0.0+

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.

B4X

Dim success As Boolean = False

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

Dim http As ChilkatHttp
http.Initialize("http")

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


Log(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 ChilkatJsonArray
jarr.Initialize
success = jarr.Load(jsonStr)
If success = False Then
    Log("Failed to load JSON.")
    Return
End If


Dim json As ChilkatJsonObject = jarr.ObjectAt(0)
Dim bdPkcs7 As ChilkatBinData
bdPkcs7.Initialize
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 ChilkatCrypt2
crypt.Initialize("crypt")

'  Validate the signedData PKCS7, and replace the contents of bdPkcs7 with the extracted signed content.
success = crypt.OpaqueVerifyBd(bdPkcs7)
If success = False Then
    Log(crypt.LastErrorText)
    Return
End If


'  The signed content is the DER of a certificate.
'  In other words, bdPkcs7 now contains a certificate.
Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadFromBd(bdPkcs7)
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


'  Show some certificate information:
Log("Subject: " & cert.SubjectDN)
Log("Serial: " & cert.SerialNumber)
Log("Issuer: " & cert.IssuerDN)

'  Let's get the cert's public key...
Dim pubKey As ChilkatPublicKey
pubKey.Initialize
cert.GetPublicKey(pubKey)

'  OK, you now have the public key and can do whatever is needed..
Log(pubKey.KeyType)
Log(pubKey.KeySize)