*/saml: start implementing unittests, fix signing

This commit is contained in:
Jens Langhammer 2020-07-11 19:57:27 +02:00
parent 2056b86ce7
commit a393097504
4 changed files with 64 additions and 16 deletions

View file

@ -1,7 +1,6 @@
"""SAML Assertion generator"""
from types import GeneratorType
from defusedxml import ElementTree
from django.http import HttpRequest
from lxml import etree # nosec
from lxml.etree import Element, SubElement # nosec
@ -212,4 +211,4 @@ class AssertionProcessor:
signed, x509_cert=self.provider.signing_kp.certificate_data
)
return etree.tostring(signed).decode("utf-8") # nosec
return ElementTree.tostring(root_response).decode()
return etree.tostring(root_response).decode("utf-8") # nosec

View file

@ -1,6 +1,6 @@
"""SAML AuthNRequest Parser and dataclass"""
from typing import Optional
from dataclasses import dataclass
from typing import Optional
from cryptography.exceptions import InvalidSignature
from defusedxml import ElementTree
@ -9,7 +9,6 @@ from structlog import get_logger
from passbook.providers.saml.exceptions import CannotHandleAssertion
from passbook.providers.saml.models import SAMLProvider
from passbook.providers.saml.utils import get_random_id
from passbook.providers.saml.utils.encoding import decode_base64_and_inflate
LOGGER = get_logger()

View file

@ -1,15 +1,20 @@
"""SAML AuthnRequest Processor"""
from defusedxml import ElementTree
from typing import Dict
from django.http import HttpRequest
from lxml import etree # nosec
from lxml.etree import Element # nosec
from signxml import XMLSigner, methods
from passbook.providers.saml.utils import get_random_id
from passbook.providers.saml.utils.encoding import deflate_and_base64_encode
from passbook.providers.saml.utils.time import get_time_string
from passbook.sources.saml.models import SAMLSource
from passbook.sources.saml.processors.constants import (
NS_MAP,
NS_SAML_ASSERTION,
NS_SAML_PROTOCOL,
NS_SIGNATURE,
)
@ -19,9 +24,14 @@ class RequestProcessor:
source: SAMLSource
http_request: HttpRequest
request_id: str
issue_instant: str
def __init__(self, source: SAMLSource, request: HttpRequest):
self.source = source
self.http_request = request
self.request_id = get_random_id()
self.issue_instant = get_time_string()
def get_issuer(self) -> Element:
"""Get Issuer Element"""
@ -35,19 +45,60 @@ class RequestProcessor:
name_id_policy.text = self.source.name_id_policy
return name_id_policy
def build_auth_n(self) -> str:
def get_auth_n(self) -> Element:
"""Get full AuthnRequest"""
auth_n_request = Element(f"{{{NS_SAML_PROTOCOL}}}AuthnRequest", nsmap=NS_MAP)
auth_n_request.attrib[
"AssertionConsumerServiceURL"
] = self.source.build_full_url(self.http_request)
auth_n_request.attrib["Destination"] = self.source.sso_url
auth_n_request.attrib["ID"] = get_random_id()
auth_n_request.attrib["IssueInstant"] = get_time_string()
auth_n_request.attrib["ID"] = self.request_id
auth_n_request.attrib["IssueInstant"] = self.issue_instant
auth_n_request.attrib["ProtocolBinding"] = self.source.binding_type
auth_n_request.attrib["Version"] = "2.0"
# Create issuer object
auth_n_request.append(self.get_issuer())
# Create NameID Policy Object
auth_n_request.append(self.get_name_id_policy())
return ElementTree.tostring(auth_n_request).decode()
return auth_n_request
def build_auth_n(self) -> str:
"""Get Signed string representation of AuthN Request
(used for POST Bindings)"""
auth_n_request = self.get_auth_n()
if self.source.signing_kp:
signed_request = XMLSigner().sign(
auth_n_request,
cert=self.source.signing_kp.certificate_data,
key=self.source.signing_kp.key_data,
)
return etree.tostring(signed_request).decode()
return etree.tostring(auth_n_request).decode()
def build_auth_n_detached(self) -> Dict[str, str]:
"""Get Dict AuthN Request for Redirect bindings, with detached
Signature"""
auth_n_request = self.get_auth_n()
response_dict = {
"SAMLRequest": deflate_and_base64_encode(
etree.tostring(auth_n_request).decode()
),
}
if self.source.signing_kp:
signer = XMLSigner(methods.detached)
signature = signer.sign(
auth_n_request,
cert=self.source.signing_kp.certificate_data,
key=self.source.signing_kp.key_data,
)
signature_value = signature.find(
f".//{{{NS_SIGNATURE}}}SignatureValue"
).text
response_dict["Signature"] = signature_value
response_dict["SigAlg"] = signer.sign_alg
return response_dict

View file

@ -11,7 +11,7 @@ from django.views.decorators.csrf import csrf_exempt
from signxml import InvalidSignature
from passbook.lib.views import bad_request_message
from passbook.providers.saml.utils.encoding import deflate_and_base64_encode, nice64
from passbook.providers.saml.utils.encoding import nice64
from passbook.sources.saml.exceptions import (
MissingSAMLResponse,
UnsupportedNameIDFormat,
@ -32,16 +32,15 @@ class InitiateView(View):
raise Http404
relay_state = request.GET.get("next", "")
request.session["sso_destination"] = relay_state
auth_n_req = RequestProcessor(source, request).build_auth_n()
auth_n_req = RequestProcessor(source, request)
# If the source is configured for Redirect bindings, we can just redirect there
if source.binding_type == SAMLBindingTypes.Redirect:
saml_request = deflate_and_base64_encode(auth_n_req)
url_args = urlencode(
{"SAMLRequest": saml_request, "RelayState": relay_state}
)
url_params = auth_n_req.build_auth_n_detached()
url_params["RelayState"] = relay_state
url_args = urlencode(url_params)
return redirect(f"{source.sso_url}?{url_args}")
# As POST Binding we show a form
saml_request = nice64(auth_n_req)
saml_request = nice64(auth_n_req.build_auth_n())
if source.binding_type == SAMLBindingTypes.POST:
return render(
request,