feat: v6.7.0 — SSO/SAML + OIDC entreprise (SP SAML signé + OIDC PKCE, auto-provisioning, groupes IdP → rôles workspace, SSO only, onglet Settings « SSO / Enterprise », API /api/v2/sso/*, help, migration 23, docs + OpenAPI 439 chemins) · 802 tests verts

2026-09-24 13:32:17 -04:00
parent 9562f30366
commit d074689b18
25 changed files with 4507 additions and 31 deletions
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+"""SAML 2.0 Service Provider — wrapper around python3-saml (OneLogin toolkit).
+
+v6.7.0. Adapts FastAPI's ``Request`` to the toolkit's flat ``request_data``
+dict and builds the SP settings from the ``sso_config`` row.
+
+What the toolkit validates in strict mode (all covered by tests):
+XML schema, signature of the assertion and/or the message against the IdP
+certificate, ``Conditions`` timestamps, ``Audience``, ``Destination``,
+``Issuer``, ``Status``, "exactly one assertion", and ``InResponseTo``
+against the AuthnRequest id we pass to ``process_response()`` — combined
+with the single-use ``sso_requests`` store that makes replay impossible.
+"""
+from __future__ import annotations
+
+import logging
+from dataclasses import dataclass, field
+
+from fastapi import Request
+
+logger = logging.getLogger(__name__)
+
+BINDING_HTTP_REDIRECT = "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect"
+BINDING_HTTP_POST = "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST"
+NAMEID_FORMAT_EMAIL = "urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress"
+
+#: Default attribute mapping (design doc §3.2). ``nameid`` = the assertion's
+#: NameID; every other value is matched against attribute Name / FriendlyName
+#: / URI local part (so ``email`` finds both ``email`` and
+#: ``http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress``).
+DEFAULT_SAML_MAPPING: dict[str, str] = {
+    "login": "nameid",
+    "email": "nameid",
+    "full_name": "displayName",
+    "avatar_url": "avatar",
+    "groups": "groups",
+}
+
+
+class SAMLError(Exception):
+    """SAML processing failure — ``message`` is user-facing, ``reason`` is logged."""
+
+
+@dataclass
+class SAMLIdentity:
+    """What a validated assertion tells us about the user."""
+
+    name_id: str
+    name_id_format: str = ""
+    session_index: str = ""
+    attributes: dict[str, list[str]] = field(default_factory=dict)
+    friendly_attributes: dict[str, list[str]] = field(default_factory=dict)
+
+    def resolve(self, source: str) -> str:
+        """Resolve one mapped source (``nameid`` or an attribute name) → first value."""
+        if not source or source == "nameid":
+            return self.name_id or ""
+        if source in self.attributes and self.attributes[source]:
+            return (self.attributes[source][0] or "").strip()
+        # FriendlyName match (case-insensitive)
+        lower = {k.lower(): v for k, v in self.friendly_attributes.items()}
+        if source.lower() in lower and lower[source.lower()]:
+            return (lower[source.lower()][0] or "").strip()
+        # URI local part match: ".../claims/emailaddress" ~ "emailaddress", and
+        # a mapping of "email" must still find ".../claims/emailaddress".
+        want = source.lower().lstrip("./")
+        for name, values in self.attributes.items():
+            if not values:
+                continue
+            local = name.rsplit("/", 1)[-1].rsplit("}", 1)[-1].lower()
+            if local == want or local.endswith(want) or want.endswith(local):
+                return (values[0] or "").strip()
+        return ""
+
+
+def external_base_url(request: Request) -> str:
+    """Scheme://host the user actually used (proxy-aware, like OAuth redirects)."""
+    proto = request.headers.get("x-forwarded-proto", "")
+    scheme = proto.split(",")[0].strip() or request.url.scheme or "http"
+    fwd_host = request.headers.get("x-forwarded-host", "")
+    host = fwd_host.split(",")[0].strip() or request.headers.get("host", "localhost:8080")
+    return f"{scheme}://{host}"
+
+
+def saml_endpoints(request: Request) -> dict[str, str]:
+    """SP entity id + ACS/SLO/metadata URLs derived from the incoming request."""
+    base = external_base_url(request)
+    return {
+        "entity_id": f"{base}/auth/saml/metadata",
+        "acs": f"{base}/auth/saml/callback",
+        "slo": f"{base}/auth/saml/logout",
+        "metadata": f"{base}/auth/saml/metadata",
+    }
+
+
+def build_settings(cfg: dict, endpoints: dict[str, str]) -> dict:
+    """python3-saml settings dict built from a ``sso_config`` row."""
+    sign_requests = bool(cfg.get("sign_requests"))
+    sp: dict = {
+        "entityId": endpoints["entity_id"],
+        "assertionConsumerService": {
+            "url": endpoints["acs"],
+            "binding": BINDING_HTTP_POST,
+        },
+        "singleLogoutService": {
+            "url": endpoints["slo"],
+            "binding": BINDING_HTTP_REDIRECT,
+        },
+        "NameIDFormat": NAMEID_FORMAT_EMAIL,
+    }
+    if cfg.get("sp_private_key") and cfg.get("sp_certificate"):
+        sp["privateKey"] = cfg["sp_private_key"]
+        sp["x509cert"] = cfg["sp_certificate"]
+
+    idp: dict = {
+        "entityId": cfg.get("entity_id") or "",
+        "singleSignOnService": {
+            "url": cfg.get("sso_url") or "",
+            "binding": BINDING_HTTP_REDIRECT,
+        },
+        "x509cert": cfg.get("x509_certificate") or "",
+    }
+    if cfg.get("slo_url"):
+        idp["singleLogoutService"] = {"url": cfg["slo_url"], "binding": BINDING_HTTP_REDIRECT}
+
+    return {
+        "strict": True,
+        "debug": False,
+        "sp": sp,
+        "idp": idp,
+        "security": {
+            "authnRequestsSigned": sign_requests,
+            "logoutRequestSigned": sign_requests,
+            "logoutResponseSigned": False,
+            "wantMessagesSigned": False,
+            "wantAssertionsSigned": True,
+            "wantNameIdEncrypted": False,
+            "wantAssertionsEncrypted": False,
+            "wantXmlValidation": True,
+            "signatureAlgorithm": "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256",
+            "digestAlgorithm": "http://www.w3.org/2001/04/xmlenc#sha256",
+            "rejectDeprecatedAlgorithm": True,
+            # FlowDeck is self-hosted: LAN/homelab deploys commonly reach the
+            # SP through single-label hosts (http://flowdeck/, docker service
+            # names). python3-saml rejects those URLs unless this is on.
+            "allowSingleLabelDomains": True,
+        },
+    }
+
+
+def _request_data(request: Request, script_name: str, post_data: dict | None = None) -> dict:
+    """Flat request dict expected by ``OneLogin_Saml2_Auth``."""
+    https = "on" if external_base_url(request).startswith("https") else "off"
+    return {
+        "https": https,
+        "http_host": request.headers.get("host", "localhost:8080"),
+        "script_name": script_name,
+        "request_uri": request.url.path,
+        "query_string": str(request.url.query or ""),
+        "get_data": dict(request.query_params),
+        "post_data": post_data or {},
+    }
+
+
+def _auth(request: Request, cfg: dict, script_name: str, post_data: dict | None = None):
+    from onelogin.saml2.auth import OneLogin_Saml2_Auth
+
+    settings = build_settings(cfg, saml_endpoints(request))
+    try:
+        return OneLogin_Saml2_Auth(
+            _request_data(request, script_name, post_data=post_data), old_settings=settings
+        )
+    except Exception as err:  # malformed IdP/SP config (bad cert, missing URL…)
+        raise SAMLError(f"Invalid SAML configuration: {err}") from err
+
+
+def create_login(request: Request, cfg: dict, relay_state: str) -> tuple[str, str]:
+    """Build the AuthnRequest. Returns ``(redirect_url, authn_request_id)``."""
+    auth = _auth(request, cfg, "/auth/saml/login")
+    try:
+        url = auth.login(return_to=relay_state)
+    except Exception as err:
+        raise SAMLError(f"Could not build the SAML AuthnRequest: {err}") from err
+    request_id = auth.get_last_request_id() or ""
+    if not request_id:
+        raise SAMLError("AuthnRequest was built without an id")
+    return url, request_id
+
+
+def process_response(request: Request, cfg: dict, post_data: dict, request_id: str) -> SAMLIdentity:
+    """Validate the IdP's SAMLResponse and extract the identity.
+
+    ``request_id`` is the id of the AuthnRequest we issued (from the
+    single-use ``sso_requests`` row): the toolkit rejects any response whose
+    ``InResponseTo`` does not match it.
+    """
+    auth = _auth(request, cfg, "/auth/saml/callback", post_data=post_data)
+    try:
+        auth.process_response(request_id=request_id or None)
+    except Exception as err:
+        raise SAMLError(f"SAML response could not be processed: {err}") from err
+
+    errors = auth.get_errors()
+    if errors:
+        raise SAMLError(auth.get_last_error_reason() or f"SAML errors: {', '.join(errors)}")
+    if not auth.is_authenticated():
+        raise SAMLError("SAML response did not authenticate the user")
+
+    name_id = auth.get_nameid() or ""
+    if not name_id:
+        raise SAMLError("SAML assertion carries no NameID")
+    return SAMLIdentity(
+        name_id=name_id,
+        name_id_format=auth.get_nameid_format() or "",
+        session_index=auth.get_session_index() or "",
+        attributes=auth.get_attributes() or {},
+        friendly_attributes=auth.get_friendlyname_attributes() or {},
+    )
+
+
+def metadata_xml(request: Request, cfg: dict) -> str:
+    """SP metadata XML (for the IdP configuration screen)."""
+    from onelogin.saml2.settings import OneLogin_Saml2_Settings
+
+    settings = OneLogin_Saml2_Settings(
+        build_settings(cfg, saml_endpoints(request)), custom_base_path=None
+    )
+    try:
+        xml = settings.get_sp_metadata()
+    except Exception as err:
+        raise SAMLError(f"Could not build the SP metadata: {err}") from err
+    if isinstance(xml, bytes):
+        xml = xml.decode("utf-8")
+    return xml
+
+
+def build_logout_url(request: Request, cfg: dict, return_to: str, name_id: str, session_index: str) -> str:
+    """SP-initiated Single Logout (HTTP-Redirect LogoutRequest to the IdP)."""
+    auth = _auth(request, cfg, "/auth/saml/logout")
+    if not cfg.get("slo_url"):
+        raise SAMLError("The IdP has no Single Logout URL configured")
+    try:
+        return auth.logout(
+            return_to=return_to,
+            name_id=name_id or None,
+            session_index=session_index or None,
+        )
+    except Exception as err:
+        raise SAMLError(f"Could not build the SAML LogoutRequest: {err}") from err
+
+
+def process_slo_form(request: Request, cfg: dict, form: dict, query: dict) -> tuple[str | None, list[str]]:
+    """Process a LogoutRequest / LogoutResponse received from the IdP.
+
+    ``form`` holds the POSTed fields, ``query`` the GET parameters (the
+    HTTP-Redirect binding delivers LogoutRequest/LogoutResponse there).
+    Returns ``(redirect_url, errors)``.
+    """
+    from onelogin.saml2.auth import OneLogin_Saml2_Auth
+
+    settings = build_settings(cfg, saml_endpoints(request))
+    https = "on" if external_base_url(request).startswith("https") else "off"
+    post_data = {k: v for k, v in form.items() if k in ("SAMLRequest", "SAMLResponse", "RelayState")}
+    if not post_data:
+        post_data = {"SAMLResponse": query["SAMLResponse"]} if "SAMLResponse" in query else {}
+    req_data = {
+        "https": https,
+        "http_host": request.headers.get("host", "localhost:8080"),
+        "script_name": "/auth/saml/logout",
+        "request_uri": request.url.path,
+        "query_string": str(request.url.query or ""),
+        "get_data": dict(query),
+        "post_data": post_data,
+    }
+    auth = OneLogin_Saml2_Auth(req_data, old_settings=settings)
+    try:
+        url = auth.process_slo(keep_local_session=True)
+    except Exception as err:
+        raise SAMLError(f"SAML logout could not be processed: {err}") from err
+    return url, auth.get_errors()