#!/usr/bin/python
# Read ASN.1/PEM CMP message on stdin, parse into
# plain text, then build substrate from it
from pyasn1.codec.der import decoder, encoder
from pyasn1_modules import rfc4210, pem
from pyasn1 import debug
import sys

if len(sys.argv) == 2 and sys.argv[1] == '-d':
    debug.setLogger(debug.Debug('all'))
elif len(sys.argv) != 1:
    print("""Usage:
$ cat cmp.pem | %s [-d]""" % sys.argv[0])
    sys.exit(-1)
    
pkiMessage = rfc4210.PKIMessage()

substrate = pem.readBase64FromFile(sys.stdin)
if not substrate:
    sys.exit(0)
        
pkiMsg, rest = decoder.decode(substrate, asn1Spec=pkiMessage)

print(pkiMsg.prettyPrint())

assert encoder.encode(pkiMsg, defMode=False) == substrate or \
       encoder.encode(pkiMsg, defMode=True) == substrate, \
       'CMP message recode fails'