following::

  gimmecert -h

  gimmecert --help

  gimmecert help

To get more details on specific command, along what mandatory and

positional arguments are available, simply provide the help flag when

running them. For example::

  gimmecert init -h

  gimmecert init --help

Quickstart

----------

Gimmecert stores all of its artefacts within the ``.gimmecert``

sub-directory (relative to where the command is run).

Start off by switching to your project directory::

  cd ~/myproject/

Initialise the necessary directories and CA hierarchy::

  gimmecert init

This will create a single CA, providing the following artifacts:

- ``.gimmecert/ca/level1.key.pem`` (private key)

- ``.gimmecert/ca/level1.cert.pem`` (certificate)

- ``.gimmecert/ca/chain-full.cert.pem`` (full CA chain, in this case

  same as ``level1.cert.pem``)

Issue a server certificate::

  gimmecert server myserver1

This will create the following artifacts for the server:

- ``.gimmecert/server/myserver1.key.pem`` (private key)

- ``.gimmecert/server/myserver1.cert.pem`` (certificate)

Resulting certificate will include its own name as one of the DNS

subject alternative names.

Issue a client certificate::

  gimmecert client myclient1

This will create the following artifacts for the client:

- ``.gimmecert/client/myclient1.key.pem`` (private key)

- ``.gimmecert/client/myclient1.cert.pem`` (certificate)

Issue a server certificate with additional DNS subject alternative

names::

  gimmecert server myserver2 myserver2.local service.example.com

This will create the following artifacts for the server:

- ``.gimmecert/server/myserver2.key.pem`` (private key)

- ``.gimmecert/server/myserver2.cert.pem`` (certificate)

This time around, the ``myserver2`` certificate will include

``myserver2``, ``myserver2.local``, and ``service.example.com`` as DNS

subject alternative names.

Issue a server certificate by passing-in certificate signing request

(CSR) from which the public key should be extracted::

  openssl req -new -newkey rsa:2048 -nodes -keyout "/tmp/myserver3.key.pem" -subj "/CN=ignoredname" -out "/tmp/myserver3.csr.pem"

  gimmecert server --csr /tmp/myserver3.csr.pem myserver3

This will create the following artifacts for the server:

- ``.gimmecert/server/myserver3.csr.pem`` (CSR)

- ``.gimmecert/server/myserver3.cert.pem`` (certificate)

Renew existing certificates, keeping the same private key and naming::

  gimmecert renew server myserver1

  gimmecert renew server myclient1

Show information about CA hierarchy and issued certificates::

  gimmecert status

Initialisation

--------------

Initialisation has to be run one before being being able to issue

server and client certificates. This is done with::

  gimmecert init

Initialisation will:

- Set-up a local directory.

- Initialise the CA hierarchy used for issuing server and client

  certificates. This includes creation of CA private keys (RSA 2048),

  as well as issuance of corresponding certificates.

If you attempt to run initialisation from the same directory twice,

Gimmecert will refuse to do so. Should you need to recreate the

hierarchy, simply remove the ``.gimmcert/`` directory, and start

over. Keep in mind you will need to throw away all of generated key

material and certificates.

The following directories are created as part of initialisation

process:

- ``.gimmecert/``, base directory.

- ``.gimmecert/ca/``, used for storing CA private keys and

  certificates.

- ``.gimmecert/server/``, used for storing server private keys and

  certificates.

- ``.gimmecert/client/``, used for storing client private keys and

  certificates.

Both CA private keys and certificates are stored as OpenSSL-style PEM

files. The naming convention for keys is ``levelN.key.pem``, while for

certificates it is ``levelN.cert.pem``. ``N`` corresponds to CA

level. Level 1 is the root/self-signed CA, level 2 is CA signed by

level 1 CA and so forth.

In addition to individual CA certificates, Gimmecert will also store

the full certificate chain (including the level 1 CA certificate) in

file ``chain-full.cert.pem``.

Subject DN naming convention for all CAs is ``CN=BASENAME Level N

CA``. ``N`` is the CA level, while ``BASENAME`` is by default equal to

current (working) directory name.

By defualt the tool will initialise a one-level CA hierarchy

(i.e. just the root CA).

Both the base name and CA hierarchy depth can be easily overridden by

providing options (both long and short forms are available)::

  gimmecert init --ca-base-name "My Project" --ca-hierarchy-depth 3

  gimmecert init -b "My Project" -d 3

The above examples would both result in creation of the following CA

artifacts:

- ``.gimmecert/ca/level1.key.pem``

- ``.gimmecert/ca/level1.cert.pem`` (subject DN ``My Project Level 1 CA``)

- ``.gimmecert/ca/level2.key.pem``

- ``.gimmecert/ca/level2.cert.pem`` (subject DN ``My Project Level 2 CA``)

- ``.gimmecert/ca/level3.key.pem``

- ``.gimmecert/ca/level3.cert.pem`` (subject DN ``My Project Level 3 CA``)

- ``.gimmecert/ca/chain-full.cert.pem``

Issuing server certificates

---------------------------

Server certificates can be issued once the initialisation is

complete. Command supports passing-in additional DNS subject

alternative names as additional positional arguments::

  gimmecert server NAME [DNS_NAME [DNS_NAME ...]]

The command will:

- Generate a 2048-bit RSA private key.

- Issue a certificate associated with the generated private key using

  the leaf CA (the one deepest in hierachy).

Resulting private keys and certificates are stored within directory

``.gimmecert/server/``. Private key naming convention is

``NAME.key.pem``, while certificates are stored as

``NAME.cert.pem``. In both cases the OpenSSL-style PEM format is used

for storage.

Subject DN naming convention for server certificates is ``CN=NAME``,

where ``NAME`` is passed-in via positional argument.

By default the certificate will include the passed-in server name as

one of its DNS subject alternative names, but additional DNS names can

be passed-in as well. For example::

  gimmecert server myserver myserver.local service.example.com

Key usage and extended key usage in certificate are set typical TLS

server use (e.g. *digital signature* + *key encipherment* for KU, and

*TLS WWW server authentication* for EKU).

In addition to generating a private key, it is also possible to

pass-in a certificate signing request (CSR). If specified path is a

dash (``-``), CSR is read from standard input. The resulting

certificate will contain public key from the CSR. All other

information stored in the CSR (naming, extensions) is ignored. For

example::

  # Issue server certificate by passing-in path to a generated CSR.

  gimmecert server --csr /tmp/myown.csr.pem myserver

  # Issue server certificate by reading the CSR from standard input.

  gimmecert server --csr - myserver

  # Issue server certificate by reading the CSR from standard input,

  # using redirection.

  gimmecert server --csr - myserver < /tmp/myown.csr.pem

The passed-in CSR will be stored alongside certificate, under

``.gimmecert/server/NAME.csr.pem``.

Issuing client certificates

---------------------------

Client certificates can be issued once the initialisation is

complete. Command accepts a single positional argument::

  gimmecert client NAME

The command will:

- Generate a 2048-bit RSA private key.

- Issue a certificate associated with the generated private key using

  the leaf CA (the one deepest in hierachy).

Rerunning the command will not overwrite existing data.

Resulting private keys and certificates are stored within directory

``.gimmecert/client/``. Private key naming convention is

``NAME.key.pem``, while certificates are stored as

``NAME.cert.pem``. In both cases the OpenSSL-style PEM format is used

for storage.

Subject DN naming convention for client certificates is ``CN=NAME``,

where ``NAME`` is passed-in via positional argument.

Key usage and extended key usage in certificate are set typical TLS

client use (e.g. *digital signature* + *key encipherment* for KU, and

*TLS WWW client authentication* for EKU).

In addition to generating a private key, it is also possible to

pass-in a certificate signing request (CSR). If specified path is a

dash (``-``), CSR is read from standard input. The resulting

certificate will contain public key from the CSR. All other

information stored in the CSR (naming, extensions) is ignored. For

example::

  # Issue client certificate by passing-in path to a generated CSR.

  gimmecert client --csr /tmp/myown.csr.pem myclient

  # Issue client certificate by reading the CSR from standard input.

  gimmecert client --csr - myclient

  # Issue client certificate by reading the CSR from standard input,

  # using redirection.

  gimmecert client --csr - myclient < /tmp/myown.csr.pem

The passed-in CSR will be stored alongside certificate, under

``.gimmecert/client/NAME.csr.pem``.

Renewing certificates

---------------------

Both client and server certificates can be renewed by simply providing

the type and name. This is useful when a certificate has expired, and

it should be renewed with identical naming and private key. Command

requires two positional argumensts::

  gimmecert renew (server|client) NAME

The command will:

- By default keep the existing private key generated for end entity

  (new one can be requested as well).

- Re-use naming and any extensions stored in existing certificate.

- Overwrite the existing certificate with a new one.

- Show information where the artifacts can be grabbed from.

To also generate a new private key during renewal, use the

``--new-private-key`` or ``-p`` option. For example::

  gimmecert renew --new-private-key server myserver

  gimmecert renew -p server my server

To replace the existing private key or CSR during renewal with a new

CSR, use the ``--csr`` option and pass along path to the file. If

specified path is a dash (``-``), CSR is read from standard input. For

example::

  gimmecert renew --csr /tmp/myserver.csr.pem server myserver

  gimmecert renew --csr - server myserver < /tmp/myserver.csr.pem

  gimmecert renew --csr - client myclient

Getting information about CA hierarchy and issued certificates

--------------------------------------------------------------

In order to show information about the CA hierarchy and issued

certificates simply run the status command::

  gimmecert status

The command will:

- Show information about every CA in generated hierarchy (subject DN,

  validity, certificate paths, whether the CA is used for issuing end

  entity certificates).

- Show information about all issued server certificates (subject DN,

  DNS subject alternative names, validity, private key or CSR path,

  certificate path).

- Show information about all issued client certificates (subject DN,

  validity, private key or CSR path, certificate path).

Validity of all certificates is shown in UTC.

Command can also be used for checking if Gimmecert has been

initialised in local directory or not.

# -*- coding: utf-8 -*-

#

# Copyright (C) 2018 Branko Majic

#

# This file is part of Gimmecert.

#

# Gimmecert is free software: you can redistribute it and/or modify it

# under the terms of the GNU General Public License as published by the Free

# Software Foundation, either version 3 of the License, or (at your option) any

# later version.

#

# Gimmecert is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

# details.

#

# You should have received a copy of the GNU General Public License along with

# Gimmecert.  If not, see <http://www.gnu.org/licenses/>.

#

import argparse

import os

import sys

from .decorators import subcommand_parser, get_subcommand_parser_setup_functions

from .commands import client, help_, init, renew, server, status, usage, ExitCode

ERROR_GENERIC = 10

DESCRIPTION = """\

Issues server and client X.509 certificates using a local CA hierarchy.

Examples:

    # Set-up and switch to directory - you can switch to existing directory too.

    mkdir myproject/

    cd myproject/

    # Initialise the local CA hierarchy and all the necessary directories.

    gimmecert init

    # Issue a TLS server certificate with only the server name in DNS subject alternative name.

    gimmecert server myserver

    # Issue a TLS server certificate with additional DNS subject alternative names.

    gimmecert server myserver extradns1.local extradns2.example.com

    # Issue a TLS server certificate by using public key from the CSR (naming/extensions are ignored).

    gimmecert server myserver --csr /tmp/myserver.csr.pem

    # Issue a TLS client certificate.

    gimmecert client myclient

    # Issue a TLS client certificate by using public key from the CSR (naming/extensions are ignored).

    gimmecert client myclient --csr /tmp/myclient.csr.pem

    gimmecert server myserver wrongdns.local

    gimmecert server myserver dontneedthisname.local

    # Renew a TLS client certificate, preserving naming and private key.

    gimmecert renew client myclient

    # Show information about CA hierarchy and issued certificates.

    gimmecert status

"""

@subcommand_parser

def setup_init_subcommand_parser(parser, subparsers):

    subparser = subparsers.add_parser('init', description='Initialise CA hierarchy.')

    subparser.add_argument('--ca-base-name', '-b', help="Base name to use for CA naming. Default is to use the working directory base name.")

    subparser.add_argument('--ca-hierarchy-depth', '-d', type=int, help="Depth of CA hierarchy to generate. Default is 1", default=1)

    def init_wrapper(args):

        project_directory = os.getcwd()

        if args.ca_base_name is None:

            args.ca_base_name = os.path.basename(project_directory)

        return init(sys.stdout, sys.stderr, project_directory, args.ca_base_name, args.ca_hierarchy_depth)

    subparser.set_defaults(func=init_wrapper)

    return subparser

@subcommand_parser

def setup_help_subcommand_parser(parser, subparsers):

    subparser = subparsers.add_parser('help', description='shows help')

    def help_wrapper(args):

        return help_(sys.stdout, sys.stderr, parser)

    subparser.set_defaults(func=help_wrapper)

    return subparser

@subcommand_parser

def setup_server_subcommand_parser(parser, subparsers):

    subparser = subparsers.add_parser('server', description='Issues server certificate.')

    subparser.add_argument('entity_name', help='Name of the server entity.')

    subparser.add_argument('dns_name', nargs='*', help='Additional DNS names to include in subject alternative name.')

    subparser.add_argument('--csr', '-c', type=str, default=None, help='''Do not generate server private key locally, and use the passed-in \

    certificate signing request (CSR) instead. Use dash (-) to read from standard input. Only the public key is taken from the CSR.''')

    def server_wrapper(args):

        project_directory = os.getcwd()

        return server(sys.stdout, sys.stderr, project_directory, args.entity_name, args.dns_name, args.csr)

    subparser.set_defaults(func=server_wrapper)

    return subparser

@subcommand_parser

def setup_client_subcommand_parser(parser, subparsers):

    subparser = subparsers.add_parser('client', description='Issue client certificate.')

    subparser.add_argument('entity_name', help='Name of the client entity.')

    subparser.add_argument('--csr', '-c', type=str, default=None, help='''Do not generate client private key locally, and use the passed-in \

    certificate signing request (CSR) instead. Use dash (-) to read from standard input. Only the public key is taken from the CSR.''')

    def client_wrapper(args):

        project_directory = os.getcwd()

        return client(sys.stdout, sys.stderr, project_directory, args.entity_name, args.csr)

    subparser.set_defaults(func=client_wrapper)

    return subparser

@subcommand_parser

def setup_renew_subcommand_parser(parser, subparsers):

    subparser = subparsers.add_parser('renew', description='Renews existing certificates.')

    subparser.add_argument('entity_type', help='Type of entity to renew.', choices=['server', 'client'])

    subparser.add_argument('entity_name', help='Name of the entity')

    def csv_list(csv):

        """

        Small helper that converts CSV string into a list.

        """

        if csv:

            return csv.split(",")

        return []

    subparser.add_argument('--update-dns-names', '-u', dest="dns_names", default=None, type=csv_list,

                           help='''Replace the DNS subject alternative names with new values. \

    Valid only for server certificate renewals. Multiple DNS names can be passed-in as comma-separated list. \

    Passing-in an empty string will result in all additional DNS subject alternative names being removed. \

    The entity name is kept as DNS subject alternative name in either case.''')

    new_private_key_or_csr_group = subparser.add_mutually_exclusive_group()

    new_private_key_or_csr_group.add_argument('--new-private-key', '-p', action='store_true', help='''Generate new private key for renewal. \

    Default is to keep the existing key. Mutually exclusive with the --csr option.''')

    new_private_key_or_csr_group.add_argument('--csr', '-c', type=str, default=None, help='''Do not use local private key and public key information from \

    existing certificate, and use the passed-in certificate signing request (CSR) instead. Use dash (-) to read from standard input. \

    If private key exists, it will be removed. Mutually exclusive with the --new-private-key option. Only the public key is taken from the CSR.''')

    def renew_wrapper(args):

        project_directory = os.getcwd()

        return renew(sys.stdout, sys.stderr, project_directory, args.entity_type, args.entity_name, args.new_private_key, args.csr, args.dns_names)

    subparser.set_defaults(func=renew_wrapper)

    return subparser

@subcommand_parser

def setup_status_subcommand_parser(parser, subparsers):

    subparser = subparsers.add_parser(name="status", description="Shows status information about issued certificates.")

    def status_wrapper(args):

        project_directory = os.getcwd()

        status(sys.stdout, sys.stderr, project_directory)

        return ExitCode.SUCCESS

    subparser.set_defaults(func=status_wrapper)

    return subparser

def get_parser():

    """

    Sets-up and returns a CLI argument parser.

    :returns: argparse.ArgumentParser -- argument parser for CLI.

    """

    parser = argparse.ArgumentParser(description=DESCRIPTION, formatter_class=argparse.RawDescriptionHelpFormatter)

    def usage_wrapper(args):

        return usage(sys.stdout, sys.stderr, parser)

    parser.set_defaults(func=usage_wrapper)

    subparsers = parser.add_subparsers()

    for setup_subcommad_parser in get_subcommand_parser_setup_functions():

        setup_subcommad_parser(parser, subparsers)

    return parser

def main():

    """

    This function is a CLI entry point for the tool. It is a thin

    wrapper around the argument parser, and underlying command

    implementation.

    In order for this to work, the parser needs to register the

    callback function as a default parameter for attribute

    'func'. This attribute is then invoked by the main function,

    passing-in all the parsed arguments while at it.

    """

    parser = get_parser()

    args = parser.parse_args()

    status_code = args.func(args)

    if status_code != ExitCode.SUCCESS:

        exit(status_code)