# Copyright (c) 2014-2016 Hewlett Packard Enterprise Development LP
#
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import hashlib
import subprocess

from requestbuilder import Arg
from requestbuilder.command import BaseCommand

from euca2ools.commands import Euca2ools


class GenerateKeyFingerprint(BaseCommand):
    DESCRIPTION = ('Show the fingerprint of a private key as it would appear '
                   'in the output of euca-describe-keypairs.\n\nNote that '
                   "this will differ from the key's SSH key fingerprint.")
    SUITE = Euca2ools
    ARGS = [Arg('privkey_filename', metavar='FILE',
                help='file containing the private key (required)')]

    def main(self):
        pkcs8 = subprocess.Popen(
            ('openssl', 'pkcs8', '-in', self.args['privkey_filename'],
             '-nocrypt', '-topk8', '-outform', 'DER'), stdout=subprocess.PIPE)
        privkey = pkcs8.communicate()[0]
        if pkcs8.returncode:
            raise subprocess.CalledProcessError(pkcs8.returncode, 'openssl')
        fprint = hashlib.sha1(privkey).hexdigest()
        return ':'.join(fprint[i:i+2] for i in range(0, len(fprint), 2))

    # pylint: disable=no-self-use
    def print_result(self, fprint):
        print fprint
    # pylint: enable=no-self-use