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certbot/letsencrypt/client/client.py
2015-04-13 17:33:11 -07:00

500 lines
17 KiB
Python

"""ACME protocol client class and helper functions."""
import logging
import os
import sys
import M2Crypto
from letsencrypt.acme import jose
from letsencrypt.acme.jose import jwk
from letsencrypt.client import auth_handler
from letsencrypt.client import continuity_auth
from letsencrypt.client import crypto_util
from letsencrypt.client import errors
from letsencrypt.client import le_util
from letsencrypt.client import network2
from letsencrypt.client import reverter
from letsencrypt.client import revoker
from letsencrypt.client.plugins.apache import configurator
from letsencrypt.client.display import ops as display_ops
from letsencrypt.client.display import enhancements
class Client(object):
"""ACME protocol client.
:ivar network: Network object for sending and receiving messages
:type network: :class:`letsencrypt.client.network2.Network`
:ivar authkey: Authorization Key
:type authkey: :class:`letsencrypt.client.le_util.Key`
:ivar reg: Registration Resource
:type reg: :class:`letsencrypt.acme.messages2.RegistrationResource`
:ivar auth_handler: Object that supports the IAuthenticator interface.
auth_handler contains both a dv_authenticator and a
continuity_authenticator
:type auth_handler: :class:`letsencrypt.client.auth_handler.AuthHandler`
:ivar installer: Object supporting the IInstaller interface.
:type installer: :class:`letsencrypt.client.interfaces.IInstaller`
:ivar config: Configuration.
:type config: :class:`~letsencrypt.client.interfaces.IConfig`
"""
def __init__(self, config, authkey, dv_auth, installer):
"""Initialize a client.
:param dv_auth: IAuthenticator that can solve the
:const:`letsencrypt.client.constants.DV_CHALLENGES`.
The :meth:`~letsencrypt.client.interfaces.IAuthenticator.prepare`
must have already been run.
:type dv_auth: :class:`letsencrypt.client.interfaces.IAuthenticator`
"""
self.authkey = authkey
self.regr = None
self.installer = installer
# TODO: Allow for other alg types besides RS256
self.network = network2.Network(
"https://%s/acme/new-reg" % config.server,
jwk.JWKRSA.load(authkey.pem))
self.config = config
if dv_auth is not None:
cont_auth = continuity_auth.ContinuityAuthenticator(config)
self.auth_handler = auth_handler.AuthHandler(
dv_auth, cont_auth, self.network, self.authkey)
else:
self.auth_handler = None
def register(self, email=None, phone=None):
"""New Registration with the ACME server.
:param str email: User's email address
:param str phone: User's phone number
"""
# TODO: properly format/scrub phone number
details = (
"mailto:" + email if email is not None else None,
"tel:" + phone if phone is not None else None
)
contact_tuple = tuple(detail for detail in details if detail is not None)
# TODO: Replace with real info once through testing.
if not contact_tuple:
contact_tuple = ("mailto:letsencrypt-client@letsencrypt.org",
"tel:+12025551212")
self.regr = self.network.register(contact=contact_tuple)
# If terms of service exist... we need to sign it.
# TODO: Replace the `preview EULA` with this...
if self.regr.terms_of_service:
self.network.agree_to_tos(self.regr)
def set_regr(self, regr):
"""Set a preexisting registration resource."""
self.regr = regr
def obtain_certificate(self, domains, csr=None):
"""Obtains a certificate from the ACME server.
:meth:`.register` must be called before :meth:`.obtain_certificate`
:param set domains: domains to get a certificate
:param csr: CSR must contain requested domains, the key used to generate
this CSR can be different than self.authkey
:type csr: :class:`CSR`
:returns: cert_file, chain_file (paths to respective files)
:rtype: `tuple` of `str`
"""
if self.auth_handler is None:
msg = ("Unable to obtain certificate because authenticator is "
"not set.")
logging.warning(msg)
raise errors.LetsEncryptClientError(msg)
if self.regr is None:
raise errors.LetsEncryptClientError(
"Please register with the ACME server first.")
# Perform Challenges/Get Authorizations
if self.regr.new_authzr_uri:
authzr = self.auth_handler.get_authorizations(
domains, self.regr.new_authzr_uri)
# This isn't required to be in the registration resource...
# and it isn't standardized... ugh - acme-spec #93
else:
authzr = self.auth_handler.get_authorizations(
domains,
"https://%s/acme/new-authz" % self.config.server)
# Create CSR from names
if csr is None:
csr = init_csr(self.authkey, domains, self.config.cert_dir)
# Retrieve certificate
certr = self.network.request_issuance(
jose.ComparableX509(
M2Crypto.X509.load_request_der_string(csr.data)),
authzr)
# Save Certificate
cert_file, chain_file = self.save_certificate(
certr, self.config.cert_path, self.config.chain_path)
revoker.Revoker.store_cert_key(
cert_file, self.authkey.file, self.config)
return cert_file, chain_file
def save_certificate(self, certr, cert_path, chain_path):
# pylint: disable=no-self-use
"""Saves the certificate received from the ACME server.
:param certr: ACME "certificate" resource.
:type certr: :class:`letsencrypt.acme.messages.Certificate`
:param str cert_path: Path to attempt to save the cert file
:param str chain_path: Path to attempt to save the chain file
:returns: cert_file, chain_file (absolute paths to the actual files)
:rtype: `tuple` of `str`
:raises IOError: If unable to find room to write the cert files
"""
# try finally close
cert_chain_abspath = None
cert_file, act_cert_path = le_util.unique_file(cert_path, 0o644)
# TODO: Except
try:
cert_file.write(certr.body.as_pem())
finally:
cert_file.close()
logging.info(
"Server issued certificate; certificate written to %s", cert_path)
if certr.cert_chain_uri:
# TODO: Except
chain_cert = self.network.fetch_chain(certr.cert_chain_uri)
chain_file, act_chain_path = le_util.unique_file(chain_path, 0o644)
try:
chain_file.write(chain_cert.to_pem())
finally:
chain_file.close()
logging.info("Cert chain written to %s", act_chain_path)
# This expects a valid chain file
cert_chain_abspath = os.path.abspath(act_chain_path)
return os.path.abspath(act_cert_path), cert_chain_abspath
def deploy_certificate(self, domains, privkey, cert_file, chain_file=None):
"""Install certificate
:param list domains: list of domains to install the certificate
:param privkey: private key for certificate
:type privkey: :class:`letsencrypt.client.le_util.Key`
:param str cert_file: certificate file path
:param str chain_file: chain file path
"""
if self.installer is None:
logging.warning("No installer specified, client is unable to deploy"
"the certificate")
raise errors.LetsEncryptClientError("No installer available")
chain = None if chain_file is None else os.path.abspath(chain_file)
for dom in domains:
self.installer.deploy_cert(dom,
os.path.abspath(cert_file),
os.path.abspath(privkey.file),
chain)
self.installer.save("Deployed Let's Encrypt Certificate")
# sites may have been enabled / final cleanup
self.installer.restart()
display_ops.success_installation(domains)
def enhance_config(self, domains, redirect=None):
"""Enhance the configuration.
.. todo:: This needs to handle the specific enhancements offered by the
installer. We will also have to find a method to pass in the chosen
values efficiently.
:param list domains: list of domains to configure
:param redirect: If traffic should be forwarded from HTTP to HTTPS.
:type redirect: bool or None
:raises letsencrypt.client.errors.LetsEncryptClientError: if
no installer is specified in the client.
"""
if self.installer is None:
logging.warning("No installer is specified, there isn't any "
"configuration to enhance.")
raise errors.LetsEncryptClientError("No installer available")
if redirect is None:
redirect = enhancements.ask("redirect")
if redirect:
self.redirect_to_ssl(domains)
def redirect_to_ssl(self, domains):
"""Redirect all traffic from HTTP to HTTPS
:param vhost: list of ssl_vhosts
:type vhost: :class:`letsencrypt.client.interfaces.IInstaller`
"""
for dom in domains:
try:
self.installer.enhance(dom, "redirect")
except errors.LetsEncryptConfiguratorError:
logging.warn("Unable to perform redirect for %s", dom)
self.installer.save("Add Redirects")
self.installer.restart()
def validate_key_csr(privkey, csr=None):
"""Validate Key and CSR files.
Verifies that the client key and csr arguments are valid and correspond to
one another. This does not currently check the names in the CSR due to
the inability to read SANs from CSRs in python crypto libraries.
If csr is left as None, only the key will be validated.
:param privkey: Key associated with CSR
:type privkey: :class:`letsencrypt.client.le_util.Key`
:param csr: CSR
:type csr: :class:`letsencrypt.client.le_util.CSR`
:raises letsencrypt.client.errors.LetsEncryptClientError: when
validation fails
"""
# TODO: Handle all of these problems appropriately
# The client can eventually do things like prompt the user
# and allow the user to take more appropriate actions
# Key must be readable and valid.
if privkey.pem and not crypto_util.valid_privkey(privkey.pem):
raise errors.LetsEncryptClientError(
"The provided key is not a valid key")
if csr:
if csr.form == "der":
csr_obj = M2Crypto.X509.load_request_der_string(csr.data)
csr = le_util.CSR(csr.file, csr_obj.as_pem(), "der")
# If CSR is provided, it must be readable and valid.
if csr.data and not crypto_util.valid_csr(csr.data):
raise errors.LetsEncryptClientError(
"The provided CSR is not a valid CSR")
# If both CSR and key are provided, the key must be the same key used
# in the CSR.
if csr.data and privkey.pem:
if not crypto_util.csr_matches_pubkey(
csr.data, privkey.pem):
raise errors.LetsEncryptClientError(
"The key and CSR do not match")
def init_key(key_size, key_dir):
"""Initializes privkey.
Inits key and CSR using provided files or generating new files
if necessary. Both will be saved in PEM format on the
filesystem. The CSR is placed into DER format to allow
the namedtuple to easily work with the protocol.
:param str key_dir: Key save directory.
"""
try:
key_pem = crypto_util.make_key(key_size)
except ValueError as err:
logging.fatal(str(err))
sys.exit(1)
# Save file
le_util.make_or_verify_dir(key_dir, 0o700)
key_f, key_filename = le_util.unique_file(
os.path.join(key_dir, "key-letsencrypt.pem"), 0o600)
key_f.write(key_pem)
key_f.close()
logging.info("Generating key (%d bits): %s", key_size, key_filename)
return le_util.Key(key_filename, key_pem)
def init_csr(privkey, names, cert_dir):
"""Initialize a CSR with the given private key.
:param privkey: Key to include in the CSR
:type privkey: :class:`letsencrypt.client.le_util.Key`
:param set names: `str` names to include in the CSR
:param str cert_dir: Certificate save directory.
"""
csr_pem, csr_der = crypto_util.make_csr(privkey.pem, names)
# Save CSR
le_util.make_or_verify_dir(cert_dir, 0o755)
csr_f, csr_filename = le_util.unique_file(
os.path.join(cert_dir, "csr-letsencrypt.pem"), 0o644)
csr_f.write(csr_pem)
csr_f.close()
logging.info("Creating CSR: %s", csr_filename)
return le_util.CSR(csr_filename, csr_der, "der")
# This should be controlled by commandline parameters
def determine_authenticator(all_auths):
"""Returns a valid IAuthenticator.
:param list all_auths: Where each is a
:class:`letsencrypt.client.interfaces.IAuthenticator` object
:returns: Valid Authenticator object or None
:raises letsencrypt.client.errors.LetsEncryptClientError: If no
authenticator is available.
"""
# Available Authenticator objects
avail_auths = []
# Error messages for misconfigured authenticators
errs = {}
for pot_auth in all_auths:
try:
pot_auth.prepare()
except errors.LetsEncryptMisconfigurationError as err:
errs[pot_auth] = err
except errors.LetsEncryptNoInstallationError:
continue
avail_auths.append(pot_auth)
if len(avail_auths) > 1:
auth = display_ops.choose_authenticator(avail_auths, errs)
elif len(avail_auths) == 1:
auth = avail_auths[0]
else:
raise errors.LetsEncryptClientError("No Authenticators available.")
if auth is not None and auth in errs:
logging.error("Please fix the configuration for the Authenticator. "
"The following error message was received: "
"%s", errs[auth])
return
return auth
def determine_installer(config):
"""Returns a valid installer if one exists.
:param config: Configuration.
:type config: :class:`letsencrypt.client.interfaces.IConfig`
:returns: IInstaller or `None`
:rtype: :class:`~letsencrypt.client.interfaces.IInstaller` or `None`
"""
installer = configurator.ApacheConfigurator(config)
try:
installer.prepare()
return installer
except errors.LetsEncryptNoInstallationError:
logging.info("Unable to find a way to install the certificate.")
return
except errors.LetsEncryptMisconfigurationError:
# This will have to be changed in the future...
return installer
def rollback(checkpoints, config):
"""Revert configuration the specified number of checkpoints.
:param int checkpoints: Number of checkpoints to revert.
:param config: Configuration.
:type config: :class:`letsencrypt.client.interfaces.IConfig`
"""
# Misconfigurations are only a slight problems... allow the user to rollback
installer = determine_installer(config)
# No Errors occurred during init... proceed normally
# If installer is None... couldn't find an installer... there shouldn't be
# anything to rollback
if installer is not None:
installer.rollback_checkpoints(checkpoints)
installer.restart()
def revoke(config, no_confirm, cert, authkey):
"""Revoke certificates.
:param config: Configuration.
:type config: :class:`letsencrypt.client.interfaces.IConfig`
"""
# Misconfigurations don't really matter. Determine installer better choose
# correctly though.
# This will need some better prepared or properly configured parameter...
# I will figure it out later...
installer = determine_installer(config)
revoc = revoker.Revoker(installer, config, no_confirm)
# Cert is most selective, so it is chosen first.
if cert is not None:
revoc.revoke_from_cert(cert[0])
elif authkey is not None:
revoc.revoke_from_key(le_util.Key(authkey[0], authkey[1]))
else:
revoc.revoke_from_menu()
def view_config_changes(config):
"""View checkpoints and associated configuration changes.
.. note:: This assumes that the installation is using a Reverter object.
:param config: Configuration.
:type config: :class:`letsencrypt.client.interfaces.IConfig`
"""
rev = reverter.Reverter(config)
rev.recovery_routine()
rev.view_config_changes()