CkPython

PKCS11 Find Certificate with Key Usage on Smart Card or USB Token

See more PKCS11 Examples

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.

CkPython

import sys
import chilkat

success = False

# 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 = chilkat.CkPkcs11()

pkcs11.put_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 = chilkat.CkCert()

# 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.")