Files
kite/backend/api/documents/content.py
T

104 lines
3.7 KiB
Python

"""Document content streaming endpoint.
Endpoints:
GET /{doc_id}/content — stream document bytes from any backend (MinIO or cloud)
Sub-router carries NO prefix — prefix="/api/documents" lives in __init__.py (D-04).
Security:
T-04-05-01: uses get_regular_user — admin role → 403 (critical security invariant).
T-04-05-02: bytes fetched via get_object() ONLY — presigned_get_url() never called.
T-04-05-03: Range header validated via _parse_range(); invalid range → 416.
T-04-05-04: access gated on ownership OR active Share.recipient_id.
DOC-04 / SEC-04: ownership assertion before serving bytes.
"""
from __future__ import annotations
import urllib.parse
from fastapi import APIRouter, Depends, HTTPException, Request, status
from fastapi.responses import StreamingResponse
from sqlalchemy.ext.asyncio import AsyncSession
from db.models import User
from api.documents.shared import get_accessible_document
from deps.auth import get_regular_user
from deps.db import get_db
from services.rate_limiting import account_limiter
from storage.exceptions import CloudConnectionError
router = APIRouter()
def _parse_range(range_header: str, file_size: int) -> tuple:
"""Parse a 'bytes=X-Y' Range header and return (start, end).
Returns (start, end) where both are inclusive byte offsets.
Raises HTTP 416 on any invalid or out-of-bounds range.
"""
try:
h = range_header.replace("bytes=", "").split("-")
start = int(h[0]) if h[0] != "" else 0
end = int(h[1]) if h[1] != "" else file_size - 1
except (ValueError, IndexError):
raise HTTPException(status.HTTP_416_RANGE_NOT_SATISFIABLE)
if start > end or start < 0 or end >= file_size:
raise HTTPException(status.HTTP_416_RANGE_NOT_SATISFIABLE)
return start, end
@router.get("/{doc_id}/content")
@account_limiter.limit("100/minute")
async def stream_document_content(
doc_id: str,
request: Request,
session: AsyncSession = Depends(get_db),
current_user: User = Depends(get_regular_user),
):
request.state.current_user = current_user
doc, _is_recipient = await get_accessible_document(session, doc_id, current_user.id)
try:
import api.documents as _doc_pkg # late import allows test monkeypatching via api.documents
storage_backend = await _doc_pkg.get_storage_backend_for_document(doc, current_user, session)
file_bytes = await storage_backend.get_object(doc.object_key)
except CloudConnectionError as exc:
raise HTTPException(
status_code=503,
detail="Cloud connection requires re-authentication. Please reconnect in Settings.",
) from exc
except HTTPException:
raise
except Exception as exc:
raise HTTPException(
status_code=502,
detail="Cloud backend unreachable. Please try again or reconnect in Settings.",
) from exc
file_size = len(file_bytes)
safe_name = urllib.parse.quote(doc.filename, safe='')
headers = {
"content-type": doc.content_type,
"content-disposition": f"inline; filename*=UTF-8''{safe_name}",
"accept-ranges": "bytes",
"content-length": str(file_size),
}
range_header = request.headers.get("range")
if range_header:
start, end = _parse_range(range_header, file_size)
chunk = file_bytes[start : end + 1]
headers["content-range"] = f"bytes {start}-{end}/{file_size}"
headers["content-length"] = str(len(chunk))
return StreamingResponse(
iter([chunk]),
status_code=206,
headers=headers,
)
return StreamingResponse(
iter([file_bytes]),
status_code=200,
headers=headers,
)