providers/saml: fix string being passed to lxml

authentik/providers/saml/processors/metadata_parser.py

@@ -5,10 +5,12 @@ from typing import Optional
 import xmlsec
 from cryptography.hazmat.backends import default_backend
 from cryptography.x509 import load_pem_x509_certificate
+from defusedxml.lxml import fromstring
 from lxml import etree  # nosec
 from structlog import get_logger
 
 from authentik.crypto.models import CertificateKeyPair
+from authentik.flows.models import Flow, FlowDesignation
 from authentik.providers.saml.models import SAMLBindings, SAMLProvider
 from authentik.providers.saml.utils.encoding import PEM_FOOTER, PEM_HEADER
 from authentik.sources.saml.processors.constants import (
@@ -23,6 +25,8 @@ LOGGER = get_logger()
 
 def format_pem_certificate(unformatted_cert: str) -> str:
     """Format single, inline certificate into PEM Format"""
+    # Ensure that all linebreaks are gone
+    unformatted_cert = unformatted_cert.replace("\n", "")
     chunks, chunk_size = len(unformatted_cert), 64
     lines = [PEM_HEADER]
     for i in range(0, chunks, chunk_size):
@@ -104,7 +108,7 @@ class ServiceProviderMetadataParser:
 
     def parse(self, raw_xml: str) -> ServiceProviderMetadata:
         """Parse raw XML to ServiceProviderMetadata"""
-        root = etree.fromstring(raw_xml)  # nosec
+        root = fromstring(raw_xml.encode())
 
         entity_id = root.attrib["entityID"]
         sp_sso_descriptors = root.findall(f"{{{NS_SAML_METADATA}}}SPSSODescriptor")