(Chilkat2-Python) PKCS11 Find Certificate with Key Usage on Smart Card or USB Token

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Demonstrates how to find and return the 1st certificate on a smart card or USB token with a desired intended key usage.

Note: This example requires Chilkat v9.5.0.91 or later.

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

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

# Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

pkcs11 = chilkat2.Pkcs11()

pkcs11.SharedLibPath = "aetpkss1.dll"

success = pkcs11.Initialize()
if (success == False):
    print(pkcs11.LastErrorText)
    sys.exit()

# Pass -1 for the slotID to open a session on the first non-empty slot.
slotID = -1

# Open a session.
readWrite = True
success = pkcs11.OpenSession(slotID,readWrite)
if (success == False):
    print(pkcs11.LastErrorText)
    sys.exit()

# Make it an authenticated session by calling Login.
# 
# If we don't authenticate, then we won't be able to see the private keys, and thus
# we won't know which certificates have an associated private key stored on the smart card.

# The smart card PIN is passed to the Login method.
# userType 1 indicates a "Normal User".
userType = 1
pin = "0000"
success = pkcs11.Login(userType,pin)
if (success == False):
    print(pkcs11.LastErrorText)
    success = pkcs11.CloseSession()
    sys.exit()

# --------------------------------------------------------------------------

cert = chilkat2.Cert()

# Find a certificate with an intended key usage.
# Possible key usages to find are:
# 
# DigitalSignature
# NonRepudiation
# KeyEncipherment
# DataEncipherment
# CertificateSigning
# CrlSigning
# 
# To find a cert having any one of several usages, pass a comma-separated list of usages:
success = pkcs11.FindCert("keyUsage","NonRepudiation,DigitalSignature",cert)
if (success == True):
    print("Cert with private key: " + cert.SubjectCN)
else:
    print("No certificates having the intended key usage were found.")

# --------------------------------------------------------------------------

# Revert to an unauthenticated session by calling Logout.
success = pkcs11.Logout()
if (success == False):
    print(pkcs11.LastErrorText)
    success = pkcs11.CloseSession()
    sys.exit()

# When finished, close the session.
# It is important to close the session (memory leaks will occur if the session is not properly closed).
success = pkcs11.CloseSession()
if (success == False):
    print(pkcs11.LastErrorText)
    sys.exit()

print("Success.")