How do I install a certificate to trusted root certificates using python?

Question

I need to write a python code that installs a certificate into my machine's (windows) or local user's trusted root certificates. I tried the below code. The code runs without error but looks like the store is not windows trusted root. I also read the documentation of wincert and win32crypt python module, nothing seems to do the job.

import OpenSSL.crypto

cert = OpenSSL.crypto.load_certificate(
    OpenSSL.crypto.FILETYPE_PEM, 
    open('certFile.crt').read()
)

store = OpenSSL.crypto.X509Store()
if not store.add_cert(cert):
    print('Success')

Edit : I need to do something similar mentioned here but using python.

Edit 2 : I also tried the below method (not sure if it will do the intended job):

import win32crypt
import sys

CERT_STORE_PROV_SYSTEM = 0x0000000A
CERT_STORE_OPEN_EXISTING_FLAG = 0x00004000
CRYPT_STRING_BASE64HEADER = 0x00000000

def main():

    store = win32crypt.CertOpenStore(CERT_STORE_PROV_SYSTEM, 0, None, CERT_SYSTEM_STORE_LOCAL_MACHINE|CERT_STORE_OPEN_EXISTING_FLAG, "ROOT")
    cert_str = open('D:\\Certificates\\certFile.crt').read()
    cert_byte = win32crypt.CryptStringToBinary(cert_str, CRYPT_STRING_BASE64HEADER)[0]
    win32crypt.CertAddSerializedElementToStore(store,cert_byte,1,2,0)

if __name__ == "__main__":

    main()
    print('done')

but I get the below error :

win32crypt.CertAddSerializedElementToStore(store,cert_byte,1,2,0)
pywintypes.error: (-2146885629, 'CertAddSerializedElementToStore', 'An error occurred while reading or writing to a file.')

prasanth_bazz · Accepted Answer · 2020-08-14T10:16:14.523

This piece of code worked for me. Posting it here just in case it helps someone.

#Flag variables
CERT_STORE_PROV_SYSTEM = 0x0000000A
CERT_STORE_OPEN_EXISTING_FLAG = 0x00004000
CRYPT_STRING_BASE64HEADER = 0x00000000
CERT_SYSTEM_STORE_CURRENT_USER_ACCOUNT = 1<<16
X509_ASN_ENCODING = 0x00000001
CERT_STORE_ADD_REPLACE_EXISTING = 3
CERT_CLOSE_STORE_FORCE_FLAG = 0x00000001

#replace with your certificate file path
crtPath = "D:\\certificates\\cert_file.crt"

with open(crtPath,'r') as f:
        cert_str = f.read()

cert_byte = win32crypt.CryptStringToBinary(cert_str, CRYPT_STRING_BASE64HEADER)[0]
store = win32crypt.CertOpenStore(CERT_STORE_PROV_SYSTEM, 0, None, CERT_SYSTEM_STORE_CURRENT_USER_ACCOUNT|CERT_STORE_OPEN_EXISTING_FLAG, "ROOT")
    
try:
   store.CertAddEncodedCertificateToStore(X509_ASN_ENCODING, cert_byte, CERT_STORE_ADD_REPLACE_EXISTING)
finally:
    store.CertCloseStore(CERT_CLOSE_STORE_FORCE_FLAG)

FYI, win32crypt module is available with pywin32 library. You can install it by running this command.

pip install pywin32

How do I install a certificate to trusted root certificates using python?

1 Answers1