feat(enterprise): Phase 14 — API Key Management + SSO/SAML 2.0

- ApiKey model (SHA-256 hash, prefix, scopes, expiry) + Alembic migration (b040ent)
- SsoConfig model for SAML 2.0 IdP settings (attribute mapping, auto-provision)
- API key auth integrated into get_current_user (aegis_ prefix detection)
- Routers: /api/v1/api-keys (full CRUD + revoke) and /api/v1/sso (metadata, login, callback, config)
- python3-saml added to requirements; Dockerfile adds libxmlsec1-dev for SAML XML signing
- QA script: 52 assertions covering key lifecycle, API key auth, SSO config

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/services/sso_service.py

@@ -0,0 +1,281 @@
+"""Phase 14: SSO / SAML 2.0 service."""
+
+from __future__ import annotations
+
+import logging
+from typing import Optional
+from uuid import UUID
+
+from sqlalchemy.orm import Session
+
+from app.domain.errors import EntityNotFoundError
+from app.models.sso_config import SsoConfig
+from app.models.user import User
+
+log = logging.getLogger(__name__)
+
+# ── python3-saml optional import ──────────────────────────────────────────────
+try:
+    from onelogin.saml2.auth import OneLogin_Saml2_Auth
+    from onelogin.saml2.settings import OneLogin_Saml2_Settings
+    from onelogin.saml2.utils import OneLogin_Saml2_Utils
+    _SAML_AVAILABLE = True
+except ImportError:  # pragma: no cover
+    _SAML_AVAILABLE = False
+    log.warning(
+        "python3-saml not installed — SAML login/callback endpoints will return 503. "
+        "Install python3-saml and its system dependencies to enable SSO."
+    )
+
+
+# ── Configuration helpers ─────────────────────────────────────────────────────
+
+def get_config(db: Session) -> Optional[SsoConfig]:
+    """Return the first (and only) SsoConfig row, or None if none exists."""
+    return db.query(SsoConfig).first()
+
+
+def get_or_404(db: Session) -> SsoConfig:
+    cfg = get_config(db)
+    if not cfg:
+        raise EntityNotFoundError("SsoConfig", "singleton")
+    return cfg
+
+
+def upsert_config(db: Session, **kwargs) -> SsoConfig:
+    """Create or update the singleton SSO config."""
+    cfg = get_config(db)
+    if cfg:
+        for k, v in kwargs.items():
+            setattr(cfg, k, v)
+        db.commit()
+        db.refresh(cfg)
+        return cfg
+    cfg = SsoConfig(**kwargs)
+    db.add(cfg)
+    db.commit()
+    db.refresh(cfg)
+    return cfg
+
+
+def is_configured(cfg: SsoConfig) -> bool:
+    """Return True if the minimum IdP settings are present."""
+    return bool(cfg.idp_entity_id and cfg.idp_sso_url and cfg.idp_certificate)
+
+
+# ── python3-saml settings builder ─────────────────────────────────────────────
+
+def _build_saml_settings(cfg: SsoConfig) -> dict:
+    sp: dict = {
+        "entityId": cfg.sp_entity_id or "",
+        "assertionConsumerService": {
+            "url": cfg.sp_acs_url or "",
+            "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST",
+        },
+        "NameIDFormat": "urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress",
+        "x509cert": cfg.sp_certificate or "",
+        "privateKey": cfg.sp_private_key or "",
+    }
+    if cfg.sp_slo_url:
+        sp["singleLogoutService"] = {
+            "url": cfg.sp_slo_url,
+            "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect",
+        }
+
+    idp: dict = {
+        "entityId": cfg.idp_entity_id or "",
+        "singleSignOnService": {
+            "url": cfg.idp_sso_url or "",
+            "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect",
+        },
+        "x509cert": cfg.idp_certificate or "",
+    }
+    if cfg.idp_slo_url:
+        idp["singleLogoutService"] = {
+            "url": cfg.idp_slo_url,
+            "binding": "urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect",
+        }
+
+    return {
+        "strict": True,
+        "debug": False,
+        "sp": sp,
+        "idp": idp,
+    }
+
+
+def _build_saml_request(request_data: dict) -> dict:
+    """Build the request dict expected by python3-saml."""
+    return {
+        "https":        "on" if request_data.get("https") else "off",
+        "http_host":    request_data.get("http_host", ""),
+        "script_name":  request_data.get("path", ""),
+        "server_port":  request_data.get("port", "443"),
+        "get_data":     request_data.get("get_data", {}),
+        "post_data":    request_data.get("post_data", {}),
+        "query_string": request_data.get("query_string", ""),
+    }
+
+
+# ── Login initiation ──────────────────────────────────────────────────────────
+
+def initiate_login(db: Session, request_data: dict) -> dict:
+    """
+    Build a SAML AuthnRequest and return the IdP redirect URL.
+
+    ``request_data`` must contain: https, http_host, path, port.
+    Returns ``{"redirect_url": ..., "request_id": ...}``.
+    Raises RuntimeError if SAML library not available or SSO not configured.
+    """
+    if not _SAML_AVAILABLE:
+        raise RuntimeError("SAML library not available — see server logs")
+
+    cfg = get_or_404(db)
+    if not cfg.is_enabled:
+        raise RuntimeError("SSO is not enabled")
+    if not is_configured(cfg):
+        raise RuntimeError("SSO IdP is not fully configured")
+
+    settings_dict = _build_saml_settings(cfg)
+    req           = _build_saml_request(request_data)
+    auth          = OneLogin_Saml2_Auth(req, old_settings=settings_dict)
+    redirect_url, request_id = auth.login(return_to=None, force_authn=False,
+                                          is_passive=False, set_nameid_policy=True,
+                                          name_id_value_req=None), auth.get_last_request_id()
+    return {"redirect_url": redirect_url, "request_id": request_id}
+
+
+# ── ACS (callback) ────────────────────────────────────────────────────────────
+
+def process_callback(db: Session, request_data: dict) -> User:
+    """
+    Process the SAML Response POSTed by the IdP.
+
+    Returns the authenticated User (creating if auto_provision is True).
+    Raises ValueError on assertion errors.
+    """
+    if not _SAML_AVAILABLE:
+        raise RuntimeError("SAML library not available — see server logs")
+
+    cfg = get_or_404(db)
+    if not cfg.is_enabled:
+        raise RuntimeError("SSO is not enabled")
+
+    settings_dict = _build_saml_settings(cfg)
+    req           = _build_saml_request(request_data)
+    auth          = OneLogin_Saml2_Auth(req, old_settings=settings_dict)
+    auth.process_response()
+
+    errors = auth.get_errors()
+    if errors:
+        raise ValueError(f"SAML assertion errors: {errors}. {auth.get_last_error_reason()}")
+
+    if not auth.is_authenticated():
+        raise ValueError("SAML authentication failed — not authenticated")
+
+    # Extract attributes
+    attrs     = auth.get_attributes()
+    name_id   = auth.get_nameid()
+    email_attr    = cfg.attr_email    or "email"
+    username_attr = cfg.attr_username or "username"
+    role_attr     = cfg.attr_role     or "role"
+
+    email    = _first_attr(attrs, email_attr)    or name_id or ""
+    username = _first_attr(attrs, username_attr) or email.split("@")[0] or name_id
+    role     = _first_attr(attrs, role_attr)     or cfg.default_role or "viewer"
+
+    # Validate role
+    valid_roles = {"admin", "red_lead", "blue_lead", "red_tech", "blue_tech", "viewer"}
+    if role not in valid_roles:
+        role = cfg.default_role or "viewer"
+
+    # Look up or provision user
+    user = db.query(User).filter(User.username == username).first()
+    if user:
+        # Refresh role from IdP on every login
+        user.role = role
+        db.commit()
+        return user
+
+    if not cfg.auto_provision:
+        raise ValueError(f"User '{username}' not found and auto-provisioning is disabled")
+
+    # Create new user (no password — SSO-only)
+    import secrets as _secrets
+    from passlib.context import CryptContext
+    _pwd_ctx = CryptContext(schemes=["bcrypt"], deprecated="auto")
+    dummy_hash = _pwd_ctx.hash(_secrets.token_hex(32))
+
+    user = User(
+        username          = username,
+        email             = email,
+        hashed_password   = dummy_hash,
+        role              = role,
+        is_active         = True,
+        must_change_password = False,
+    )
+    db.add(user)
+    db.commit()
+    db.refresh(user)
+    return user
+
+
+def _first_attr(attrs: dict, name: str) -> Optional[str]:
+    """Return the first value of a SAML attribute, or None."""
+    v = attrs.get(name)
+    if isinstance(v, list) and v:
+        return str(v[0])
+    if isinstance(v, str):
+        return v
+    return None
+
+
+# ── SP Metadata ───────────────────────────────────────────────────────────────
+
+def get_sp_metadata(db: Session) -> str:
+    """
+    Generate SP SAML metadata XML.
+
+    Uses python3-saml if available; falls back to a minimal hand-built XML
+    so the endpoint is always functional for configuration purposes.
+    """
+    cfg = get_or_404(db)
+    settings_dict = _build_saml_settings(cfg)
+
+    if _SAML_AVAILABLE:
+        saml_settings = OneLogin_Saml2_Settings(settings=settings_dict, sp_validation_only=True)
+        metadata = saml_settings.get_sp_metadata()
+        errors   = saml_settings.validate_metadata(metadata)
+        if errors:
+            log.warning("SP metadata validation warnings: %s", errors)
+        return metadata.decode() if isinstance(metadata, bytes) else metadata
+
+    # Fallback: minimal XML without signing (useful for dev/testing)
+    sp = settings_dict["sp"]
+    acs = sp.get("assertionConsumerService", {})
+    return f"""<?xml version="1.0"?>
+<md:EntityDescriptor xmlns:md="urn:oasis:names:tc:SAML:2.0:metadata"
+    entityID="{sp.get('entityId', '')}">
+  <md:SPSSODescriptor
+      AuthnRequestsSigned="false"
+      WantAssertionsSigned="true"
+      protocolSupportEnumeration="urn:oasis:names:tc:SAML:2.0:protocol">
+    <md:AssertionConsumerService
+        Binding="{acs.get('binding', '')}"
+        Location="{acs.get('url', '')}"
+        index="1"/>
+  </md:SPSSODescriptor>
+</md:EntityDescriptor>"""
+
+
+def get_status(db: Session) -> dict:
+    """Return SSO status summary."""
+    cfg = get_config(db)
+    if not cfg:
+        return {"enabled": False, "provider_name": None, "configured": False, "login_url": None}
+    return {
+        "enabled":       cfg.is_enabled,
+        "provider_name": cfg.provider_name,
+        "configured":    is_configured(cfg),
+        "login_url":     "/api/v1/sso/login" if cfg.is_enabled and is_configured(cfg) else None,
+    }