(CkPython) Get ETK Public Key (api-acpt.ehealth.fgov.be)

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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 Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

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

http = chilkat.CkHttp()

jsonStr = http.quickGetStr("https://api-acpt.ehealth.fgov.be/etee/v1/etks?identifier=12345678901&type=SSIN")
if (http.get_LastMethodSuccess() == False):
    print(http.lastErrorText())
    sys.exit()

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.
jarr = chilkat.CkJsonArray()
success = jarr.Load(jsonStr)
if (success == False):
    print("Failed to load JSON.")
    sys.exit()

# json is a CkJsonObject
json = jarr.ObjectAt(0)
bdPkcs7 = chilkat.CkBinData()
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.
crypt = chilkat.CkCrypt2()

# Validate the signedData PKCS7, and replace the contents of bdPkcs7 with the extracted signed content.
success = crypt.OpaqueVerifyBd(bdPkcs7)
if (success == False):
    print(crypt.lastErrorText())
    sys.exit()

# The signed content is the DER of a certificate.
# In other words, bdPkcs7 now contains a certificate.
cert = chilkat.CkCert()
success = cert.LoadFromBd(bdPkcs7)
if (success == False):
    print(cert.lastErrorText())
    sys.exit()

# Show some certificate information:
print("Subject: " + cert.subjectDN())
print("Serial: " + cert.serialNumber())
print("Issuer: " + cert.issuerDN())

# Let's get the cert's public key...
# pubKey is a CkPublicKey
pubKey = cert.ExportPublicKey()
if (cert.get_LastMethodSuccess() == False):
    print(cert.lastErrorText())
    sys.exit()

# OK, you now have the public key and can do whatever is needed..
print(pubKey.keyType())
print(str(pubKey.get_KeySize()))