Files
BanGUI/backend/app/models/auth.py
Lukas 32aad186c3 TASK-031: Enforce bcrypt 72-byte password limit
Bcrypt silently truncates passwords at 72 bytes, so passwords longer than 72
characters provide no additional security. This commit enforces the 72-byte
maximum across the authentication and setup flows.

Changes:
- Add max_length=72 to LoginRequest.password and SetupRequest.master_password
- Update field validator in SetupRequest to explicitly check max_length
- Add comprehensive tests for password length validation (6 new test cases)
- Document the 72-byte limitation in Features.md (master password options)
- Add new section 12 'Password Hashing' in Backend-Development.md explaining:
  - The bcrypt truncation behavior
  - Why the limit is enforced
  - The validation flow from frontend to backend
  - What happens when passwords exceed the limit

All existing tests pass, no regressions introduced.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-04-26 15:38:20 +02:00

51 lines
1.5 KiB
Python

"""Authentication Pydantic models.
Request, response, and domain models used by the auth router and service.
"""
from pydantic import BaseModel, ConfigDict, Field
class LoginRequest(BaseModel):
"""Payload for ``POST /api/auth/login``."""
model_config = ConfigDict(strict=True)
password: str = Field(
...,
max_length=72,
description="Master password to authenticate with (max 72 bytes due to bcrypt truncation).",
)
class LoginResponse(BaseModel):
"""Successful login response.
The session token is also set as an ``HttpOnly`` cookie by the router.
This model documents the JSON body for API-first consumers.
"""
model_config = ConfigDict(strict=True)
token: str = Field(..., description="Session token for use in subsequent requests.")
expires_at: str = Field(..., description="ISO 8601 UTC expiry timestamp.")
class LogoutResponse(BaseModel):
"""Response body for ``POST /api/auth/logout``."""
model_config = ConfigDict(strict=True)
message: str = Field(default="Logged out successfully.")
class Session(BaseModel):
"""Internal domain model representing a persisted session record."""
model_config = ConfigDict(strict=True)
id: int = Field(..., description="Auto-incremented row ID.")
token: str = Field(..., description="Opaque session token.")
created_at: str = Field(..., description="ISO 8601 UTC creation timestamp.")
expires_at: str = Field(..., description="ISO 8601 UTC expiry timestamp.")