#!/usr/bin/env python
#
# This file is part of pyasn1-modules software.
#
# Created by Stanisław Pitucha with asn1ate tool.
# Copyright (c) 2005-2020, Ilya Etingof <etingof@gmail.com>
# License: https://www.pysnmp.com/pyasn1/license.html
#
# Read ASN.1/PEM X.509 certificates on stdin, parse each into plain text,
# then build substrate from it (using RFC5280)
#
import sys

from pyasn1.codec.der import decoder, encoder

from pyasn1_modules import pem, rfc5280

if len(sys.argv) != 1:
    print(
        """Usage:
$ cat CACertificate.pem | %s
$ cat userCertificate.pem | %s"""
        % (sys.argv[0], sys.argv[0])
    )
    sys.exit(-1)

certType = rfc5280.Certificate()

certCnt = 0

while 1:
    idx, substrate = pem.readPemBlocksFromFile(
        sys.stdin, ("-----BEGIN CERTIFICATE-----", "-----END CERTIFICATE-----")
    )
    if not substrate:
        break

    cert, rest = decoder.decode(substrate, asn1Spec=certType)

    if rest:
        substrate = substrate[: -len(rest)]

    print(cert.prettyPrint())

    assert encoder.encode(cert) == substrate, "cert recode fails"

    certCnt += 1

print("*** %s PEM cert(s) de/serialized" % certCnt)