Rework argument processing

And also README.
This commit is contained in:
Timotej Lazar 2024-01-16 21:51:47 +01:00
parent 5f0ceead24
commit 79958bb100
2 changed files with 98 additions and 81 deletions

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@ -4,40 +4,43 @@ Python script to replace [MargTools](https://businessconnect.margis.si/output/#o
## Usage
Create the configuration file `~/.margfools`. The contents are described in the sections below.
Run `margfools -h` for a synopsis of command‐line arguments. Allowed arguments are
### Certificates in files
margfools [-h] [-e {file,pkcs11}] [-k KEYFILE] [-c CERTFILE] [-i <KEY ID>] URL
If you are using certificate files, add the paths to your TLS private key and certificate in PEM format:
To use a signing key and certificate stored in PEM files, install `openssl` and run
[https://gcsign.example.com/BCSign/]
key = <path/to/key.pem>
cert = <path/to/cert.pem>
margfools -e file -k KEYFILE -c CERTFILE bc-digsign://sign?…
### Certificates on smartcards
To sign using a PIV-II smartcard such as the Yubikey, install `pkcs11-tool` from [OpenSC](https://github.com/OpenSC/OpenSC) and run
If you have your certificate on a PIV-II smart card (e.g. Yubikey), first determine the slot on your card which contains the certificate you wish to use:
margfools -e pkcs11 -i <KEY ID> bc-digsign://sign?…
The script will prompt for the PIN to unlock the smartcard. To find the key ID, run
pkcs11-tool -O
Look for "ID:" in the output.
Assuming the ID of your certificate was 07, specify the engine and certificate slot in your config file:
[https://gcsign.example.com/BCSign/]
engine = pkcs11
key = 07
You will be asked for your pin during signing.
### Add URL schema
Section name is the percent-decoded value of `baseURL` in
bc-digsign://sign?accessToken=…&baseUrl=https%3a%2f%2fgcsign.example.com%2fBCSign%2f&…'
You can set `margfools` as the default program for `bc-digsign` URLs by copying the `margfools.desktop` file to `~/.local/share/applications/` and running
To use `margfools` from the web app, set it as the default program for `x-scheme-handler/bc-digsign` URLs, or copy the `margfools.desktop` file to `~/.local/share/applications/` and run
xdg-mime default margfools.desktop x-scheme-handler/bc-digsign
or by setting the default application in your browser.
For this to work, the script must be configured as described below.
## Configuration
Settings can be saved on a per‐site basis in `~/.margfools` using the [configparser](https://docs.python.org/3/library/configparser.html) format.
[DEFAULT]
engine = pkcs11
[https://gcsign.example.org/BCSign/]
id = 02
[https://gcsign.example.com/BCSign/]
engine = file
keyfile = <path/to/key.pem>
certfile = <path/to/cert.pem>
All settings can be specified for all sites in the default section, or for individual sites. The section name should match the percent-decoded value of `baseURL` in
bc-digsign://sign?…&baseUrl=https%3a%2f%2fgcsign.example.com%2fBCSign%2f&

124
margfools
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@ -14,25 +14,61 @@ import getpass
# use requests instead of urllib.request for keep-alive connection
import requests
def sign(b64data, key, pin=None, engine=None):
if engine is None:
# key in file
cmd = ['openssl', 'pkeyutl', '-sign', '-inkey', key, '-pkeyopt', 'digest:sha256']
env = None
data = base64.b64decode(b64data)
elif engine == 'pkcs11':
# key on smartcard
digest_info = { # from RFC 3447
'MD2': '3020300c06082a864886f70d020205000410',
'MD5': '3020300c06082a864886f70d020505000410',
'SHA-1': '3021300906052b0e03021a05000414',
'SHA-256': '3031300d060960864801650304020105000420',
'SHA-384': '3041300d060960864801650304020205000430',
'SHA-512': '3051300d060960864801650304020305000440'
}
cmd = ['pkcs11-tool', '--id', key, '-s', '-m', 'RSA-PKCS', '-p', 'env:PIN']
env = {'PIN': pin}
data = bytes.fromhex(digest_info['SHA-256']) + base64.b64decode(b64data)
def init(args):
args.params = urllib.parse.parse_qs(args.url.query)
args.access_token = args.params["accessToken"][0]
args.start_token = args.params["startSigningToken"][0]
args.url = args.params['baseUrl'][0]
# if missing, get options from section [url] in ~/.margfools
config = configparser.ConfigParser()
config.read(os.path.expanduser('~') + '/.margfools')
if not args.engine:
args.engine = config.get(args.url, 'engine', fallback='file')
match args.engine:
case 'file':
if not args.keyfile:
args.keyfile = config.get(args.url, 'keyfile', fallback=None)
if not args.certfile:
args.certfile = config.get(args.url, 'certfile', fallback=None)
if not args.keyfile or not args.certfile:
raise Exception('key or certificate file not specified')
args.cert = ''.join(line.strip() for line in open(args.certfile) if not line.startswith('-----'))
case 'pkcs11':
if not args.id:
args.id = config.get(args.url, 'id', fallback=None)
if not args.id:
raise Exception('key ID not specified')
args.cert = base64.b64encode(subprocess.run(['pkcs11-tool', '--read-object', '--type', 'cert', '--id', args.id], capture_output=True).stdout).decode()
args.pin = getpass.getpass('PIN: ')
case '_':
raise Exception(f'invalid engine {args.engine}')
def sign(b64data, args):
match args.engine:
case 'file':
if not args.keyfile:
raise Exception('keyfile not specified')
cmd = ['openssl', 'pkeyutl', '-sign', '-inkey', args.keyfile, '-pkeyopt', 'digest:sha256']
env = None
data = base64.b64decode(b64data)
case 'pkcs11':
if not args.id:
raise Exception('key ID not specified')
digest_info = { # from RFC 3447
'MD2': '3020300c06082a864886f70d020205000410',
'MD5': '3020300c06082a864886f70d020505000410',
'SHA-1': '3021300906052b0e03021a05000414',
'SHA-256': '3031300d060960864801650304020105000420',
'SHA-384': '3041300d060960864801650304020205000430',
'SHA-512': '3051300d060960864801650304020305000440'
}
cmd = ['pkcs11-tool', '--id', args.id, '-s', '-m', 'RSA-PKCS', '-p', 'env:PIN']
env = {'PIN': args.pin}
data = bytes.fromhex(digest_info['SHA-256']) + base64.b64decode(b64data)
case '_':
raise Exception(f'invalid engine {args.engine}')
p = subprocess.run(cmd, env=env, input=data, capture_output=True)
if p.returncode != 0:
@ -43,64 +79,42 @@ def sign(b64data, key, pin=None, engine=None):
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='Fake the MargTools application.')
parser.add_argument('url', type=urllib.parse.urlparse, help='bc-digsign:// url')
parser.add_argument('-e', '--engine', type=str, help='"pkcs11" for smart card')
parser.add_argument('-k', '--key', type=pathlib.Path, help='key file')
parser.add_argument('-c', '--cert', type=pathlib.Path, help='certificate file')
parser.add_argument('-e', '--engine', choices=('file', 'pkcs11'), help='use key file or PKCS11 token?')
parser.add_argument('-k', '--keyfile', type=pathlib.Path, help='key file')
parser.add_argument('-c', '--certfile', type=pathlib.Path, help='certificate file')
parser.add_argument('-i', '--id', type=int, metavar='<KEY ID>', help='key ID on PKCS11 token')
args = parser.parse_args()
try:
# parse query string
params = urllib.parse.parse_qs(args.url.query)
url = params['baseUrl'][0]
token = params['accessToken'][0]
# parse query string and load certificates
init(args)
# if missing, get options from section [url] in ~/.margfools
config = configparser.ConfigParser()
config.read(os.path.expanduser('~') + '/.margfools')
if not args.engine:
args.engine = config.get(url, 'engine', fallback=None)
if not args.key:
args.key = config.get(url, 'key')
if not args.cert:
args.cert = config.get(url, 'cert', fallback=None)
if not args.key:
raise Exception('key not specified')
pin = None
if args.engine is None:
if not args.cert:
raise Exception('certificate not specified')
args.cert = ''.join(line.strip() for line in open(args.cert) if not line.startswith('-----'))
elif args.engine == 'pkcs11':
args.cert = base64.b64encode(subprocess.run(['pkcs11-tool', '--read-object', '--type', 'cert', '--id', args.key], capture_output=True).stdout).decode()
pin = getpass.getpass('PIN: ')
session = requests.Session()
headers = {'Authorization': f'Bearer {token}'}
headers = {'Authorization': f'Bearer {args.access_token}'}
# delete old signing session
r = session.delete(f'{url}/signatures/{params["startSigningToken"][0]}', headers=headers)
r = session.delete(f'{args.url}/signatures/{args.params["startSigningToken"][0]}', headers=headers)
# register a certificate or sign a document, makes no difference to us
if params.get('registerCertificate'):
if args.params.get('registerCertificate'):
q = {'registerCertificate': 1}
else:
q = {'documentId': [i for i in params['documentId'][0].split(',')]}
q = {'documentId': [i for i in args.params['documentId'][0].split(',')]}
qs = urllib.parse.urlencode(q, doseq=True)
r = session.post(f'{url}/signatures?{qs}', headers=headers)
r = session.post(f'{args.url}/signatures?{qs}', headers=headers)
# get signature request and mix in my secrets and publics
request = json.loads(r.text)
request['AuthenticationToken'] = token
request['AuthenticationToken'] = args.access_token
request['CertificatePublicKey'] = args.cert
# keep signing whatever they send us
while True:
for name in ('AttachmentHashes', 'XmlHashes'):
if values := request.get(name, []):
request[f'Signed{name}'] = [sign(v, args.key, pin, engine=args.engine) for v in values]
request[f'Signed{name}'] = [sign(v, args) for v in values]
r = session.put(f'{url}signatures/{request["SignatureRequestId"]}',
r = session.put(f'{args.url}signatures/{request["SignatureRequestId"]}',
headers=headers | {'Content-Type': 'application/json; charset=utf-8'},
data=json.dumps(request).encode())
if not r.text: