(Tcl) 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.

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

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

set http [new_CkHttp]

set jsonStr [CkHttp_quickGetStr $http "https://api-acpt.ehealth.fgov.be/etee/v1/etks?identifier=12345678901&type=SSIN"]
if {[CkHttp_get_LastMethodSuccess $http] == 0} then {
    puts [CkHttp_lastErrorText $http]
    delete_CkHttp $http
    exit
}

puts "$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.
set jarr [new_CkJsonArray]

set success [CkJsonArray_Load $jarr $jsonStr]
if {$success == 0} then {
    puts "Failed to load JSON."
    delete_CkHttp $http
    delete_CkJsonArray $jarr
    exit
}

# json is a CkJsonObject
set json [CkJsonArray_ObjectAt $jarr 0]
set bdPkcs7 [new_CkBinData]

CkBinData_AppendEncoded $bdPkcs7 [CkJsonObject_stringOf $json "value"] "base64"
delete_CkJsonObject $json

# Let's verify the PKCS7, and then examine the signing cert,
# and get the signing cert's public key.
set crypt [new_CkCrypt2]

# Validate the signedData PKCS7, and replace the contents of bdPkcs7 with the extracted signed content.
set success [CkCrypt2_OpaqueVerifyBd $crypt $bdPkcs7]
if {$success == 0} then {
    puts [CkCrypt2_lastErrorText $crypt]
    delete_CkHttp $http
    delete_CkJsonArray $jarr
    delete_CkBinData $bdPkcs7
    delete_CkCrypt2 $crypt
    exit
}

# The signed content is the DER of a certificate.
# In other words, bdPkcs7 now contains a certificate.
set cert [new_CkCert]

set success [CkCert_LoadFromBd $cert $bdPkcs7]
if {$success == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkHttp $http
    delete_CkJsonArray $jarr
    delete_CkBinData $bdPkcs7
    delete_CkCrypt2 $crypt
    delete_CkCert $cert
    exit
}

# Show some certificate information:
puts "Subject: [CkCert_subjectDN $cert]"
puts "Serial: [CkCert_serialNumber $cert]"
puts "Issuer: [CkCert_issuerDN $cert]"

# Let's get the cert's public key...
# pubKey is a CkPublicKey
set pubKey [CkCert_ExportPublicKey $cert]
if {[CkCert_get_LastMethodSuccess $cert] == 0} then {
    puts [CkCert_lastErrorText $cert]
    delete_CkHttp $http
    delete_CkJsonArray $jarr
    delete_CkBinData $bdPkcs7
    delete_CkCrypt2 $crypt
    delete_CkCert $cert
    exit
}

# OK, you now have the public key and can do whatever is needed..
puts [CkPublicKey_keyType $pubKey]
puts [CkPublicKey_get_KeySize $pubKey]

delete_CkPublicKey $pubKey


delete_CkHttp $http
delete_CkJsonArray $jarr
delete_CkBinData $bdPkcs7
delete_CkCrypt2 $crypt
delete_CkCert $cert