Add SonarQube/Codacy conventions and harden network security

CLAUDE.md

@@ -36,6 +36,7 @@ pybreeze/
     ├── logging/                 # pybreeze_logger
     ├── file_process/            # File/directory utilities
     ├── json_format/             # JSON processing
+    ├── network/                 # URL validation (SSRF prevention)
     └── manager/package_manager/ # PackageManager class
 ```
 
@@ -95,25 +96,135 @@ All code must follow secure-by-default principles. Review every change against t
 - Never use `subprocess.Popen(..., shell=True)` — always pass argument lists
 - Never log or display secrets, tokens, passwords, or API keys
 - Use `json.loads()` / `json.dumps()` for serialisation — never pickle
+- Never use `yaml.load()` — always use `yaml.safe_load()`
 - Validate all user input at system boundaries (file dialogs, URL inputs, network data)
+- Handle exceptions without leaking stack traces, file paths, or internal state to the user
 
 ### Network requests (SSRF prevention)
-- All outbound HTTP requests must go through `diagram_net_utils.safe_download_image()` or equivalent guards
-- Only `http://` and `https://` schemes are allowed — block `file://`, `ftp://`, `data:`, `gopher://`
-- Resolved IP addresses must be checked against private/loopback/link-local ranges (`ipaddress.is_private`, `is_loopback`, `is_link_local`, `is_reserved`)
-- Enforce download size limits (default: 20 MB) and connection timeouts (default: 15s)
-- Never pass user-supplied URLs directly to `urlopen()` without validation
+- **All** outbound HTTP requests to user-specified URLs must validate the target before connecting:
+  1. Only `http://` and `https://` schemes — block `file://`, `ftp://`, `data:`, `gopher://`
+  2. Resolve the hostname and check IPs against private/loopback/link-local/reserved ranges (`ipaddress.is_private`, `is_loopback`, `is_link_local`, `is_reserved`)
+  3. Enforce connection timeouts (default: 15 s for downloads, 30 s for API calls)
+  4. Enforce response size limits where applicable (default: 20 MB for binary downloads)
+- Reference implementation: `diagram_net_utils._validate_url()` and `safe_download_image()`
+- For API-style requests (`requests.get/post`): create or reuse a URL validation helper that performs scheme + IP checks, then call it before every `requests.*` call
+- Disable automatic redirect following (`allow_redirects=False`) or re-validate the redirect target to prevent redirect-based SSRF
+- Never pass user-supplied URLs directly to `urlopen()` or `requests.*` without validation
+
+### Network requests (TLS / SSH)
+- All HTTPS requests must use default TLS verification — never set `verify=False`
+- SSH connections: never use `paramiko.AutoAddPolicy()` or `paramiko.WarningPolicy()` — both silently accept unknown host keys and are vulnerable to MITM. Use `InteractiveHostKeyPolicy` from `pybreeze.pybreeze_ui.connect_gui.ssh.ssh_host_key_policy` (via `apply_host_key_policy(client, parent_widget)`), which prompts the user with the SHA256 fingerprint on first connection and persists confirmed keys to `~/.pybreeze/ssh_known_hosts`
+
+### Subprocess execution
+- Always pass argument lists to `subprocess.Popen` / `subprocess.run` — never `shell=True`
+- Explicitly set `shell=False` for clarity in new code
+- Never interpolate user input into command strings — pass as separate list elements
+- Set `timeout` on all `subprocess.run()` calls to prevent hangs
+- The IDE intentionally runs user-authored scripts; this is trusted local execution, not arbitrary remote code. Subprocess hardening protects against accidental shell injection, not against malicious local files
+
+### JupyterLab integration
+- The embedded JupyterLab server binds to `localhost` only and is intended for local development
+- `--ServerApp.token=` and `--ServerApp.password=` are deliberately empty to enable seamless embedding — this is safe only because the server is localhost-only
+- Do not change `--ServerApp.ip` to `0.0.0.0` or any externally-reachable address
+- `--ServerApp.disable_check_xsrf=True` is required for the embedded QWebEngineView; do not expose the server externally with XSRF disabled
 
 ### File I/O
 - File read/write paths from user dialogs (`QFileDialog`) are trusted (user-initiated)
 - File paths loaded from saved data (`.diagram.json`) must be validated before access:
   - Local paths: check `path.is_file()` and verify extension is in an allowlist
   - URLs: pass through the same SSRF validation as user-entered URLs
 - Never construct file paths by string concatenation with user input — use `pathlib.Path` with validation
+- When writing to data directories (`.pybreeze/`), create the directory with `os.makedirs(exist_ok=True)` and always use `encoding="utf-8"`
+- Never follow symlinks from untrusted sources — use `Path.resolve(strict=True)` and verify the resolved path is still within expected boundaries
 
 ### Qt / UI
 - `QGraphicsTextItem` with `TextEditorInteraction` must not be enabled by default — use double-click-to-edit pattern to prevent unintended text selection issues in themed environments
 - Plugin loading (`jeditor_plugins/`) uses auto-discovery — only load `.py` files, skip files starting with `_` or `.`
+- `QWebEngineView.setUrl()` must only load trusted URLs (localhost or user-confirmed external URLs) — never load untrusted HTML or URLs without user consent
+- Never call `QWebEngineView.setHtml()` with unsanitised content — this enables XSS within the embedded browser
+
+### Secrets and credentials
+- SSH passwords and private key passphrases are held in memory only during the session — never persist to disk or logs
+- Password fields must use `QLineEdit.EchoMode.Password`
+- API endpoint URLs may contain embedded tokens — treat URL strings with the same care as credentials (do not log full URLs)
+- Environment variables (`PYBREEZE_LOG_MAX_BYTES`, etc.) must never contain secrets; use dedicated secure stores for credentials
+
+### Dependency security
+- Pin dependencies to exact versions in `requirements.txt` / `dev_requirements.txt`
+- Do not add new dependencies without reviewing their security posture (maintained? known CVEs?)
+- Avoid transitive dependency bloat — prefer stdlib solutions when the alternative is a single-function dependency
+
+## Code quality (SonarQube / Codacy compliance)
+
+All code must satisfy common static-analysis rules enforced by SonarQube and Codacy. Review each change against the checklist below.
+
+### Complexity & size
+- Cyclomatic complexity per function: ≤ 15 (hard cap 20). Break large branches into helpers
+- Cognitive complexity per function: ≤ 15. Flatten nested `if`/`for`/`try` chains with early returns or guard clauses
+- Function length: ≤ 75 lines of code (excluding docstring / blank lines). Extract helpers past that
+- Parameter count: ≤ 7 per function/method. Use a dataclass or typed dict when more are needed
+- Nesting depth: ≤ 4 levels of `if`/`for`/`while`/`try`. Refactor with early returns instead of pyramids
+- File length: ≤ 1000 lines — split modules past that
+- Class `__init__`: keep attribute count reasonable; if a class has > 15 instance attributes, split responsibilities
+
+### Exception handling
+- Never use bare `except:` — always specify exception types
+- Avoid catching `Exception` or `BaseException` unless immediately re-raising or logging and re-raising with context
+- Never `pass` silently inside `except` — log the error via `pybreeze_logger` (at minimum `.debug()`) with context
+- Do not `return` / `break` / `continue` inside a `finally` block — it swallows exceptions
+- Custom exceptions must inherit from `ITEException`; never `raise Exception(...)` directly
+- Use `raise ... from err` (or `raise ... from None`) when re-raising to preserve / suppress the chain explicitly
+
+### Pythonic correctness
+- Compare with `None` using `is` / `is not`, never `==` / `!=`
+- Type checks use `isinstance(obj, T)`, never `type(obj) == T`
+- Never use mutable default arguments (`def f(x=[])`) — use `None` and initialise inside
+- Prefer f-strings over `%` formatting or `str.format()`
+- Use context managers (`with open(...) as f:`) for every file / socket / lock — never leave resources to GC
+- Use `enumerate()` instead of `range(len(...))` when the index is needed alongside the item
+- Use `dict.get(key, default)` instead of `key in dict and dict[key]` patterns
+- Use set / dict comprehensions when clearer than manual loops; avoid comprehensions with side effects
+
+### Naming & style (PEP 8)
+- `snake_case` for functions, methods, variables, module names
+- `PascalCase` for classes
+- `UPPER_SNAKE_CASE` for module-level constants
+- `_leading_underscore` for protected / internal members; never use `__dunder__` for custom attributes
+- No single-letter names except loop indices (`i`, `j`) or conventional math (`x`, `y`)
+- Do not shadow built-ins (`id`, `type`, `list`, `dict`, `input`, `file`, `open`, etc.) — rename the local variable
+
+### Duplication & dead code
+- String literal used 3+ times in the same module → extract a module-level constant
+- Identical 6+ line blocks in 2+ places → extract a helper function
+- Remove unused imports, unused parameters, unused local variables, unreachable code after `return` / `raise`
+- No commented-out code blocks — delete them (git history is the archive)
+- No `TODO` / `FIXME` / `XXX` without an accompanying issue reference (`# TODO(#123): ...`)
+
+### Logging, printing, assertions
+- Never use `print()` for diagnostics in library / runtime code — use `pybreeze_logger`
+- Use lazy logging (`logger.debug("x=%s", x)`) — avoid eager f-string formatting inside log calls on hot paths
+- Never use `assert` for runtime validation (Python strips assertions with `-O`). Use explicit `if … raise …` instead; `assert` is only for test code
+
+### Hardcoded values & secrets
+- No hardcoded passwords, tokens, API keys, or secrets — use env vars or a config file excluded from VCS
+- No hardcoded IP addresses or hostnames outside of `localhost` / documented loopback — use config
+- Magic numbers (except 0, 1, -1) should be named constants when repeated or non-obvious
+
+### Boolean & return hygiene
+- Replace `if cond: return True else: return False` with `return bool(cond)` or `return cond`
+- Replace `if x == True` / `if x == False` with `if x` / `if not x`
+- A function should have a consistent return type — never mix `return value` and bare `return` (returns `None`) on meaningful paths unless explicitly documented
+- Do not return inside a generator function (`yield` + `return value` is a syntax pitfall)
+
+### Imports
+- One import per line for `import` statements; grouped `from x import a, b` is fine
+- Order: stdlib → third-party → first-party (`pybreeze.*`) — separated by blank lines
+- No wildcard imports (`from x import *`) outside of `__init__.py` re-exports
+- No relative imports beyond one level (`from ..pkg import x` OK, `from ...pkg import x` avoid)
+
+### Running the linters
+- Before committing any non-trivial change, run `ruff check pybreeze/` locally to catch these rules — `ruff` covers the majority of SonarQube/Codacy Python rules
+- When adding a new rule exception, justify it in a `# noqa: RULE` comment with a short reason — never blanket-disable
 
 ## Commit & PR rules
 

pybreeze/__main__.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from pybreeze import start_editor
 
 start_editor()

pybreeze/extend/process_executor/python_task_process_manager.py

@@ -5,7 +5,7 @@
 import subprocess
 import sys
 import threading
-import typing
+from typing import Callable
 from pathlib import Path
 from queue import Queue
 from threading import Thread
@@ -42,8 +42,8 @@ class TaskProcessManager:
     def __init__(
             self,
             main_window: CodeWindow,
-            task_done_trigger_function: typing.Callable | None = None,
-            error_trigger_function: typing.Callable | None = None,
+            task_done_trigger_function: Callable | None = None,
+            error_trigger_function: Callable | None = None,
             program_buffer_size: int = 1024,
             program_encoding: str = "utf-8"
     ):
@@ -60,8 +60,8 @@ def __init__(
         self.run_error_queue: Queue = Queue()
         self.process: subprocess.Popen | None = None
 
-        self.task_done_trigger_function: typing.Callable = task_done_trigger_function
-        self.error_trigger_function: typing.Callable = error_trigger_function
+        self.task_done_trigger_function: Callable = task_done_trigger_function
+        self.error_trigger_function: Callable = error_trigger_function
         self.program_buffer_size = program_buffer_size
 
     def renew_path(self) -> None:

pybreeze/extend/process_executor/test_pioneer/test_pioneer_process_manager.py

@@ -10,7 +10,6 @@
 
 from PySide6.QtCore import QTimer
 from PySide6.QtGui import QTextCharFormat
-from PySide6.QtWidgets import QWidget
 from je_editor.pyside_ui.main_ui.save_settings.user_color_setting_file import actually_color_dict
 from je_editor.utils.venv_check.check_venv import check_and_choose_venv
 
@@ -31,7 +30,6 @@ def __init__(
             encoding: str = "utf-8",
     ):
         self._main_window: PyBreezeMainWindow = main_window
-        self._widget: QWidget = main_window.tab_widget.currentWidget()
         # Code window init
         self._code_window = CodeWindow()
         self._main_window.current_run_code_window.append(self._code_window)

pybreeze/extend_multi_language/extend_english.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from je_editor import english_word_dict
 
 # PyBreeze-specific English translations
@@ -99,6 +101,13 @@
     "test_pioneer_create_template_label": "Create TestPioneer Yaml template",
     "test_pioneer_run_yaml": "Execute Test Pioneer Yaml",
     "test_pioneer_not_choose_yaml": "Please choose a Yaml file",
+    # SSH host key verification
+    "ssh_host_key_policy_dialog_title_verify_host": "Verify SSH host key",
+    "ssh_host_key_policy_dialog_message_verify_host": (
+        "The authenticity of host '{host}' cannot be established.\n"
+        "{key_type} key fingerprint is {fingerprint}.\n\n"
+        "Do you want to trust this host and continue connecting?"
+    ),
     # SSH command widget
     "ssh_command_widget_window_title_ssh_command_widget": "SSH Command Widget",
     "ssh_command_widget_button_label_send_command": "Send",

pybreeze/extend_multi_language/extend_traditional_chinese.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from je_editor import traditional_chinese_word_dict
 
 # PyBreeze-specific Traditional Chinese translations
@@ -99,6 +101,13 @@
     "test_pioneer_create_template_label": "建立 TestPioneer Yaml 模板",
     "test_pioneer_run_yaml": "執行 Test Pioneer Yaml",
     "test_pioneer_not_choose_yaml": "請選擇 Yaml 檔案",
+    # SSH host key verification
+    "ssh_host_key_policy_dialog_title_verify_host": "驗證 SSH 主機金鑰",
+    "ssh_host_key_policy_dialog_message_verify_host": (
+        "無法驗證主機 '{host}' 的真實性。\n"
+        "{key_type} 金鑰指紋為 {fingerprint}。\n\n"
+        "是否信任此主機並繼續連線？"
+    ),
     # SSH command widget
     "ssh_command_widget_window_title_ssh_command_widget": "SSH 指令介面",
     "ssh_command_widget_button_label_send_command": "送出",

pybreeze/extend_multi_language/update_language_dict.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from pybreeze.extend_multi_language.extend_english import update_english_word_dict
 from pybreeze.extend_multi_language.extend_traditional_chinese import \
     update_traditional_chinese_word_dict

pybreeze/pybreeze_ui/connect_gui/ssh/ssh_command_widget.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import os
 import re
 
@@ -10,6 +12,7 @@
 )
 from je_editor import language_wrapper
 
+from pybreeze.pybreeze_ui.connect_gui.ssh.ssh_host_key_policy import apply_host_key_policy
 from pybreeze.pybreeze_ui.connect_gui.ssh.ssh_login_widget import LoginWidget
 from pybreeze.utils.logging.logger import pybreeze_logger
 
@@ -137,7 +140,8 @@
 
         try:
             self.ssh_client = paramiko.SSHClient()
-            self.ssh_client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+            apply_host_key_policy(self.ssh_client, self)
+            pybreeze_logger.info("SSH connecting to %s:%s", host, port)
 
             if use_key:
                 if not os.path.exists(key_path):

pybreeze/pybreeze_ui/connect_gui/ssh/ssh_file_viewer_widget.py

@@ -1,4 +1,7 @@
+from __future__ import annotations
+
 import os
+import stat
 from pathlib import Path
 
 import paramiko
@@ -9,7 +12,9 @@
 )
 from je_editor import language_wrapper
 
+from pybreeze.pybreeze_ui.connect_gui.ssh.ssh_host_key_policy import apply_host_key_policy
 from pybreeze.pybreeze_ui.connect_gui.ssh.ssh_login_widget import LoginWidget
+from pybreeze.utils.logging.logger import pybreeze_logger
 
 
 class SFTPClientWrapper:
@@ -25,14 +30,16 @@ def __init__(self):
         self.root_path: str = "/"
 
     def connect(self, host: str, port: int, username: str, password: str,
-                use_key: bool = False, key_path: str = ""):
+                use_key: bool = False, key_path: str = "",
+                parent_widget: QWidget | None = None):
         """
         Establish SSH + SFTP connection.
         建立 SSH + SFTP 連線。
         """
         self.close()
         self._ssh = paramiko.SSHClient()
-        self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+        apply_host_key_policy(self._ssh, parent_widget)
+        pybreeze_logger.info("SFTP connecting to %s:%s", host, port)
         if use_key and key_path:
             pkey = None
             for KeyType in (paramiko.RSAKey, paramiko.Ed25519Key, paramiko.ECDSAKey):
@@ -96,8 +103,6 @@ def is_dir(self, path: str) -> bool:
             ))
         try:
             st = self._sftp.stat(path)
-            # S_ISDIR check via stat.S_ISDIR
-            import stat
             return stat.S_ISDIR(st.st_mode)
         except OSError:
             return False
@@ -210,7 +215,7 @@ def _connect(self):
                 self.word_dict.get("ssh_file_viewer_dialog_message_missing_input"))
             return
         try:
-            self.client.connect(host, port, user, pwd, use_key, key_path)
+            self.client.connect(host, port, user, pwd, use_key, key_path, parent_widget=self)
             self.load_root("/")
         except Exception as e:
             QMessageBox.critical(
@@ -294,7 +299,6 @@ def populate_children(self, parent_item: QTreeWidgetItem):
         try:
             entries = self.client.list_dir(path)
             # Sort: dirs first, then files
-            import stat
             dirs = []
             files = []
             for e in entries:
@@ -307,10 +311,9 @@ def populate_children(self, parent_item: QTreeWidgetItem):
                 else:
                     files.append((name, e))
             for name, e in dirs + files:
-                import stat as _stat
                 full_path = os.path.join(path if path != "/" else "", name)
                 full_path = full_path if full_path.startswith("/") else f"/{full_path}"
-                typ = "dir" if _stat.S_ISDIR(e.st_mode) else "file"
+                typ = "dir" if stat.S_ISDIR(e.st_mode) else "file"
                 size = e.st_size if typ == "file" else 0
                 child = self.make_item(name, typ, size, full_path)
                 parent_item.addChild(child)