def store_request(buf, overwrite=False, address="", user=""):
"""
Store CSR for later processing
"""
if not buf:
raise ValueError("No signing request supplied")
if pem.detect(buf):
header, _, der_bytes = pem.unarmor(buf)
csr = CertificationRequest.load(der_bytes)
else:
csr = CertificationRequest.load(buf)
buf = pem_armor_csr(csr)
common_name = csr["certification_request_info"]["subject"].native[
"common_name"]
if not re.match(const.RE_COMMON_NAME, common_name):
raise ValueError("Invalid common name %s" % repr(common_name))
request_path = os.path.join(config.REQUESTS_DIR, common_name + ".pem")
# If there is cert, check if it's the same
if os.path.exists(request_path) and not overwrite:
if open(request_path, "rb").read() == buf:
raise errors.RequestExists("Request already exists")
else:
raise errors.DuplicateCommonNameError(
"Another request with same common name already exists")
else:
with open(request_path + ".part", "wb") as fh:
fh.write(buf)
os.rename(request_path + ".part", request_path)
attach_csr = buf, "application/x-pem-file", common_name + ".csr"
mailer.send("request-stored.md",
attachments=(attach_csr, ),
common_name=common_name)
setxattr(request_path, "user.request.address", address)
setxattr(request_path, "user.request.user", user)
try:
hostname, aliaslist, ipaddrlist = socket.gethostbyaddr(address)
except (socket.herror,
OSError): # Failed to resolve hostname or resolved to multiple
pass
else:
setxattr(request_path, "user.request.hostname", hostname)
return request_path, csr, common_name
def on_put(self, req, resp):
# Consume token
now = time()
timestamp = req.get_param_as_int("t", required=True)
username = req.get_param("u", required=True)
user = User.objects.get(username)
csum = hashlib.sha256()
csum.update(config.TOKEN_SECRET)
csum.update(username.encode("ascii"))
csum.update(str(timestamp).encode("ascii"))
margin = 300 # Tolerate 5 minute clock skew as Kerberos does
if csum.hexdigest() != req.get_param("c", required=True):
raise falcon.HTTPForbidden("Forbidden", "Invalid token supplied, did you copy-paste link correctly?")
if now < timestamp - margin:
raise falcon.HTTPForbidden("Forbidden", "Token not valid yet, are you sure server clock is correct?")
if now > timestamp + margin + config.TOKEN_LIFETIME:
raise falcon.HTTPForbidden("Forbidden", "Token expired")
# At this point consider token to be legitimate
body = req.stream.read(req.content_length)
header, _, der_bytes = pem.unarmor(body)
csr = CertificationRequest.load(der_bytes)
common_name = csr["certification_request_info"]["subject"].native["common_name"]
assert common_name == username or common_name.startswith(username + "@"), "Invalid common name %s" % common_name
try:
_, resp.body = self.authority._sign(csr, body, profile="default",
overwrite=config.TOKEN_OVERWRITE_PERMITTED)
resp.set_header("Content-Type", "application/x-pem-file")
logger.info("Autosigned %s as proven by token ownership", common_name)
except FileExistsError:
logger.info("Won't autosign duplicate %s", common_name)
raise falcon.HTTPConflict(
"Certificate with such common name (CN) already exists",
"Will not overwrite existing certificate signing request, explicitly delete existing one and try again")
def get_request(common_name):
if not re.match(const.RE_COMMON_NAME, common_name):
raise ValueError("Invalid common name %s" % repr(common_name))
path = os.path.join(config.REQUESTS_DIR, common_name + ".pem")
try:
with open(path, "rb") as fh:
buf = fh.read()
header, _, der_bytes = pem.unarmor(buf)
return path, buf, CertificationRequest.load(der_bytes), \
datetime.utcfromtimestamp(os.stat(path).st_ctime)
except EnvironmentError:
raise errors.RequestDoesNotExist("Certificate signing request file %s does not exist" % path)
def sign(common_name, overwrite=False):
"""
Sign certificate signing request by it's common name
"""
req_path = os.path.join(config.REQUESTS_DIR, common_name + ".pem")
with open(req_path) as fh:
csr_buf = fh.read()
header, _, der_bytes = pem.unarmor(csr_buf)
csr = CertificationRequest.load(der_bytes)
# Sign with function below
cert, buf = _sign(csr, csr_buf, overwrite)
os.unlink(req_path)
return cert, buf
def on_put(self, req, resp):
try:
username, mail, created, expires, profile = self.manager.consume(req.get_param("token", required=True))
except RelationalMixin.DoesNotExist:
raise falcon.HTTPForbidden("Forbidden", "No such token or token expired")
body = req.stream.read(req.content_length)
header, _, der_bytes = pem.unarmor(body)
csr = CertificationRequest.load(der_bytes)
common_name = csr["certification_request_info"]["subject"].native["common_name"]
if not common_name.startswith(username + "@"):
raise falcon.HTTPBadRequest("Bad requst", "Invalid common name %s" % common_name)
try:
_, resp.body = self.authority._sign(csr, body, profile=config.PROFILES.get(profile),
overwrite=config.TOKEN_OVERWRITE_PERMITTED)
resp.set_header("Content-Type", "application/x-pem-file")
logger.info("Autosigned %s as proven by token ownership", common_name)
except FileExistsError:
logger.info("Won't autosign duplicate %s", common_name)
raise falcon.HTTPConflict(
"Certificate with such common name (CN) already exists",
"Will not overwrite existing certificate signing request, explicitly delete existing one and try again")
def sign(common_name,
skip_notify=False,
skip_push=False,
overwrite=False,
profile="default",
signer=None):
"""
Sign certificate signing request by it's common name
"""
req_path = os.path.join(config.REQUESTS_DIR, common_name + ".pem")
with open(req_path, "rb") as fh:
csr_buf = fh.read()
header, _, der_bytes = pem.unarmor(csr_buf)
csr = CertificationRequest.load(der_bytes)
# Sign with function below
cert, buf = _sign(csr, csr_buf, skip_notify, skip_push, overwrite, profile,
signer)
os.unlink(req_path)
return cert, buf
def on_post(self, req, resp):
"""
Validate and parse certificate signing request, the RESTful way
"""
reasons = []
body = req.stream.read(req.content_length)
try:
header, _, der_bytes = pem.unarmor(body)
csr = CertificationRequest.load(der_bytes)
except ValueError:
logger.info(
"Malformed certificate signing request submission from %s blocked",
req.context.get("remote_addr"))
raise falcon.HTTPBadRequest(
"Bad request", "Malformed certificate signing request")
else:
req_public_key = asymmetric.load_public_key(
csr["certification_request_info"]["subject_pk_info"])
if self.authority.public_key.algorithm != req_public_key.algorithm:
logger.info(
"Attempt to submit %s based request from %s blocked, only %s allowed"
% (req_public_key.algorithm.upper(),
req.context.get("remote_addr"),
self.authority.public_key.algorithm.upper()))
raise falcon.HTTPBadRequest(
"Bad request", "Incompatible asymmetric key algorithms")
common_name = csr["certification_request_info"]["subject"].native[
"common_name"]
"""
Determine whether autosign is allowed to overwrite already issued
certificates automatically
"""
overwrite_allowed = False
for subnet in config.OVERWRITE_SUBNETS:
if req.context.get("remote_addr") in subnet:
overwrite_allowed = True
break
"""
Handle domain computer automatic enrollment
"""
machine = req.context.get("machine")
if machine:
reasons.append("machine enrollment not allowed from %s" %
req.context.get("remote_addr"))
for subnet in config.MACHINE_ENROLLMENT_SUBNETS:
if req.context.get("remote_addr") in subnet:
if common_name != machine:
raise falcon.HTTPBadRequest(
"Bad request",
"Common name %s differs from Kerberos credential %s!"
% (common_name, machine))
# Automatic enroll with Kerberos machine cerdentials
resp.set_header("Content-Type", "application/x-pem-file")
cert, resp.body = self.authority._sign(
csr,
body,
profile=config.PROFILES["rw"],
overwrite=overwrite_allowed)
logger.info(
"Automatically enrolled Kerberos authenticated machine %s from %s",
machine, req.context.get("remote_addr"))
return
"""
Attempt to renew certificate using currently valid key pair
"""
try:
path, buf, cert, signed, expires = self.authority.get_signed(
common_name)
except EnvironmentError:
pass # No currently valid certificate for this common name
else:
cert_pk = cert["tbs_certificate"]["subject_public_key_info"].native
csr_pk = csr["certification_request_info"][
"subject_pk_info"].native
# Same public key
if cert_pk == csr_pk:
buf = req.get_header("X-SSL-CERT")
if buf:
# Used mutually authenticated TLS handshake, assume renewal
header, _, der_bytes = pem.unarmor(
buf.replace("\t", "\n").replace("\n\n",
"\n").encode("ascii"))
handshake_cert = x509.Certificate.load(der_bytes)
if handshake_cert.native == cert.native:
for subnet in config.RENEWAL_SUBNETS:
if req.context.get("remote_addr") in subnet:
resp.set_header(
"Content-Type",
"application/x-x509-user-cert")
setxattr(path, "user.revocation.reason",
"superseded")
_, resp.body = self.authority._sign(
csr,
body,
overwrite=True,
profile=SignatureProfile.from_cert(cert))
logger.info(
"Renewing certificate for %s as %s is whitelisted",
common_name,
req.context.get("remote_addr"))
return
reasons.append("renewal failed")
else:
# No renewal requested, redirect to signed API call
resp.status = falcon.HTTP_SEE_OTHER
resp.location = os.path.join(
os.path.dirname(req.relative_uri), "signed",
common_name)
return
"""
Process automatic signing if the IP address is whitelisted,
autosigning was requested and certificate can be automatically signed
"""
if req.get_param_as_bool("autosign"):
for subnet in config.AUTOSIGN_SUBNETS:
if req.context.get("remote_addr") in subnet:
try:
resp.set_header("Content-Type",
"application/x-pem-file")
_, resp.body = self.authority._sign(
csr,
body,
overwrite=overwrite_allowed,
profile=config.PROFILES["rw"])
logger.info(
"Signed %s as %s is whitelisted for autosign",
common_name, req.context.get("remote_addr"))
return
except EnvironmentError:
logger.info(
"Autosign for %s from %s failed, signed certificate already exists",
common_name, req.context.get("remote_addr"))
reasons.append(
"autosign failed, signed certificate already exists"
)
break
else:
reasons.append("IP address not whitelisted for autosign")
else:
reasons.append("autosign not requested")
# Attempt to save the request otherwise
try:
request_path, _, _ = self.authority.store_request(
body, address=str(req.context.get("remote_addr")))
except errors.RequestExists:
reasons.append("same request already uploaded exists")
# We should still redirect client to long poll URL below
except errors.DuplicateCommonNameError:
# TODO: Certificate renewal
logger.warning(
"rejected signing request with overlapping common name from %s",
req.context.get("remote_addr"))
raise falcon.HTTPConflict(
"CSR with such CN already exists",
"Will not overwrite existing certificate signing request, explicitly delete CSR and try again"
)
else:
push.publish("request-submitted", common_name)
# Wait the certificate to be signed if waiting is requested
logger.info("Signing request %s from %s put on hold, %s", common_name,
req.context.get("remote_addr"), ", ".join(reasons))
if req.get_param("wait"):
# Redirect to nginx pub/sub
url = config.LONG_POLL_SUBSCRIBE % hashlib.sha256(body).hexdigest()
click.echo("Redirecting to: %s" % url)
resp.status = falcon.HTTP_SEE_OTHER
resp.set_header("Location", url)
else:
# Request was accepted, but not processed
resp.status = falcon.HTTP_202
resp.body = ". ".join(reasons)
if req.client_accepts("application/json"):
resp.body = json.dumps(
{
"title": "Accepted",
"description": resp.body
},
cls=MyEncoder)
def on_post(self, req, resp):
"""
Validate and parse certificate signing request, the RESTful way
"""
reasons = []
body = req.stream.read(req.content_length).encode("ascii")
header, _, der_bytes = pem.unarmor(body)
csr = CertificationRequest.load(der_bytes)
common_name = csr["certification_request_info"]["subject"].native["common_name"]
"""
Handle domain computer automatic enrollment
"""
machine = req.context.get("machine")
if machine:
if config.MACHINE_ENROLLMENT_ALLOWED:
if common_name != machine:
raise falcon.HTTPBadRequest(
"Bad request",
"Common name %s differs from Kerberos credential %s!" % (common_name, machine))
# Automatic enroll with Kerberos machine cerdentials
resp.set_header("Content-Type", "application/x-pem-file")
cert, resp.body = authority._sign(csr, body, overwrite=True)
logger.info(u"Automatically enrolled Kerberos authenticated machine %s from %s",
machine, req.context.get("remote_addr"))
return
else:
reasons.append("Machine enrollment not allowed")
"""
Attempt to renew certificate using currently valid key pair
"""
try:
path, buf, cert = authority.get_signed(common_name)
except EnvironmentError:
pass # No currently valid certificate for this common name
else:
cert_pk = cert["tbs_certificate"]["subject_public_key_info"].native
csr_pk = csr["certification_request_info"]["subject_pk_info"].native
if cert_pk == csr_pk: # Same public key, assume renewal
expires = cert["tbs_certificate"]["validity"]["not_after"].native.replace(tzinfo=None)
renewal_header = req.get_header("X-Renewal-Signature")
if not renewal_header:
# No header supplied, redirect to signed API call
resp.status = falcon.HTTP_SEE_OTHER
resp.location = os.path.join(os.path.dirname(req.relative_uri), "signed", common_name)
return
try:
renewal_signature = b64decode(renewal_header)
except TypeError, ValueError:
logger.error(u"Renewal failed, bad signature supplied for %s", common_name)
reasons.append("Renewal failed, bad signature supplied")
else:
try:
asymmetric.rsa_pss_verify(
asymmetric.load_certificate(cert),
renewal_signature, buf + body, "sha512")
except SignatureError:
logger.error(u"Renewal failed, invalid signature supplied for %s", common_name)
reasons.append("Renewal failed, invalid signature supplied")
else:
# At this point renewal signature was valid but we need to perform some extra checks
if datetime.utcnow() > expires:
logger.error(u"Renewal failed, current certificate for %s has expired", common_name)
reasons.append("Renewal failed, current certificate expired")
elif not config.CERTIFICATE_RENEWAL_ALLOWED:
logger.error(u"Renewal requested for %s, but not allowed by authority settings", common_name)
reasons.append("Renewal requested, but not allowed by authority settings")
else:
resp.set_header("Content-Type", "application/x-x509-user-cert")
_, resp.body = authority._sign(csr, body, overwrite=True)
logger.info(u"Renewed certificate for %s", common_name)
return
def on_post(self, req, resp):
"""
Validate and parse certificate signing request, the RESTful way
"""
reasons = []
body = req.stream.read(req.content_length)
try:
header, _, der_bytes = pem.unarmor(body)
csr = CertificationRequest.load(der_bytes)
except ValueError:
raise falcon.HTTPBadRequest(
"Bad request", "Malformed certificate signing request")
common_name = csr["certification_request_info"]["subject"].native[
"common_name"]
"""
Handle domain computer automatic enrollment
"""
machine = req.context.get("machine")
if machine:
if config.MACHINE_ENROLLMENT_ALLOWED:
if common_name != machine:
raise falcon.HTTPBadRequest(
"Bad request",
"Common name %s differs from Kerberos credential %s!" %
(common_name, machine))
# Automatic enroll with Kerberos machine cerdentials
resp.set_header("Content-Type", "application/x-pem-file")
cert, resp.body = self.authority._sign(csr,
body,
overwrite=True)
logger.info(
"Automatically enrolled Kerberos authenticated machine %s from %s",
machine, req.context.get("remote_addr"))
return
else:
reasons.append("Machine enrollment not allowed")
"""
Attempt to renew certificate using currently valid key pair
"""
try:
path, buf, cert, signed, expires = self.authority.get_signed(
common_name)
except EnvironmentError:
pass # No currently valid certificate for this common name
else:
cert_pk = cert["tbs_certificate"]["subject_public_key_info"].native
csr_pk = csr["certification_request_info"][
"subject_pk_info"].native
if cert_pk == csr_pk: # Same public key, assume renewal
expires = cert["tbs_certificate"]["validity"][
"not_after"].native.replace(tzinfo=None)
renewal_header = req.get_header("X-Renewal-Signature")
if not renewal_header:
# No header supplied, redirect to signed API call
resp.status = falcon.HTTP_SEE_OTHER
resp.location = os.path.join(
os.path.dirname(req.relative_uri), "signed",
common_name)
return
try:
renewal_signature = b64decode(renewal_header)
except (TypeError, ValueError):
logger.error(
"Renewal failed, bad signature supplied for %s",
common_name)
reasons.append("Renewal failed, bad signature supplied")
else:
try:
asymmetric.rsa_pss_verify(
asymmetric.load_certificate(cert),
renewal_signature, buf + body, "sha512")
except SignatureError:
logger.error(
"Renewal failed, invalid signature supplied for %s",
common_name)
reasons.append(
"Renewal failed, invalid signature supplied")
else:
# At this point renewal signature was valid but we need to perform some extra checks
if datetime.utcnow() > expires:
logger.error(
"Renewal failed, current certificate for %s has expired",
common_name)
reasons.append(
"Renewal failed, current certificate expired")
elif not config.CERTIFICATE_RENEWAL_ALLOWED:
logger.error(
"Renewal requested for %s, but not allowed by authority settings",
common_name)
reasons.append(
"Renewal requested, but not allowed by authority settings"
)
else:
resp.set_header("Content-Type",
"application/x-x509-user-cert")
_, resp.body = self.authority._sign(csr,
body,
overwrite=True)
logger.info("Renewed certificate for %s",
common_name)
return
"""
Process automatic signing if the IP address is whitelisted,
autosigning was requested and certificate can be automatically signed
"""
if req.get_param_as_bool("autosign"):
if not self.authority.server_flags(common_name):
for subnet in config.AUTOSIGN_SUBNETS:
if req.context.get("remote_addr") in subnet:
try:
resp.set_header("Content-Type",
"application/x-pem-file")
_, resp.body = self.authority._sign(csr, body)
logger.info("Autosigned %s as %s is whitelisted",
common_name,
req.context.get("remote_addr"))
return
except EnvironmentError:
logger.info(
"Autosign for %s from %s failed, signed certificate already exists",
common_name, req.context.get("remote_addr"))
reasons.append(
"Autosign failed, signed certificate already exists"
)
break
else:
reasons.append(
"Autosign failed, IP address not whitelisted")
else:
reasons.append(
"Autosign failed, only client certificates allowed to be signed automatically"
)
# Attempt to save the request otherwise
try:
request_path, _, _ = self.authority.store_request(
body, address=str(req.context.get("remote_addr")))
except errors.RequestExists:
reasons.append("Same request already uploaded exists")
# We should still redirect client to long poll URL below
except errors.DuplicateCommonNameError:
# TODO: Certificate renewal
logger.warning(
"Rejected signing request with overlapping common name from %s",
req.context.get("remote_addr"))
raise falcon.HTTPConflict(
"CSR with such CN already exists",
"Will not overwrite existing certificate signing request, explicitly delete CSR and try again"
)
else:
push.publish("request-submitted", common_name)
# Wait the certificate to be signed if waiting is requested
logger.info("Stored signing request %s from %s", common_name,
req.context.get("remote_addr"))
if req.get_param("wait"):
# Redirect to nginx pub/sub
url = config.LONG_POLL_SUBSCRIBE % hashlib.sha256(body).hexdigest()
click.echo("Redirecting to: %s" % url)
resp.status = falcon.HTTP_SEE_OTHER
resp.set_header("Location", url)
logger.debug("Redirecting signing request from %s to %s",
req.context.get("remote_addr"), url)
else:
# Request was accepted, but not processed
resp.status = falcon.HTTP_202
resp.body = ". ".join(reasons)
if req.client_accepts("application/json"):
resp.body = json.dumps(
{
"title": "Accepted",
"description": resp.body
},
cls=MyEncoder)