PKCS experiments

pkcs_experiments_1.py

# load OpenSSL.crypto
from OpenSSL import crypto

# open it, using password. Supply/read your own from stdin.
p12 = crypto.load_pkcs12(open("/path/to/cert.p12", 'rb').read(), passwd)

# get various properties of said file.
# note these are PyOpenSSL objects, not strings although you
# can convert them to PEM-encoded strings.
p12.get_certificate()     # (signed) certificate object
p12.get_privatekey()      # private key.
p12.get_ca_certificates() # ca chain.

pkcs_experiments_2.py

def pkcs12_to_pem(pkcs12_data, password):
    # Old versions of OpenSSL.crypto.load_pkcs12() fail if the password is a unicode object
    if isinstance(password, unicode):
        password_bytes = password.encode('utf8')
    else:
        password_bytes = password
    p12 = OpenSSL.crypto.load_pkcs12(pkcs12_data, password_bytes)
    p12_cert = p12.get_certificate()
    p12_key = p12.get_privatekey()
    pem_cert = OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_PEM, p12_cert)
    pem_key = OpenSSL.crypto.dump_privatekey(OpenSSL.crypto.FILETYPE_PEM, p12_key)
    pem = pem_cert + pem_key
    return pem