hermes-agent/hermes_cli/approvals_suggest.py

482 lines
17 KiB
Python

"""``hermes approvals suggest`` — mine approval history into allowlist proposals.
Hermes has no dedicated approval-decision ledger: ``always`` answers land in
``command_allowlist`` (config.yaml) via :func:`tools.approval.save_permanent_allowlist`,
while ``once``/``session`` approvals are in-memory only. What *does* persist
is the session DB (``~/.hermes/state.db``): every assistant ``terminal`` tool
call is stored with its arguments, and the paired ``role='tool'`` result
records whether the command was blocked/denied ("BLOCKED: User denied …",
"Asking the user for approval") or actually executed.
So this module mines *implied approvals*: a command that matches a
dangerous-command class (the same :func:`tools.approval.detect_dangerous_command`
classifier that triggers the prompt) AND whose tool result is not a
block/denial marker must have been approved by the user (once, session,
always, smart-approve, or yolo) before it ran. Frequently re-approved
patterns are exactly the prompts worth turning into one-time allowlist
policy — the port of Claude Code's ``/fewer-permission-prompts``.
Safety posture:
* **Never auto-applies.** The default run is a dry proposal; only an explicit
``--apply N[,M...]`` merges the chosen patterns into ``command_allowlist``
via the existing :func:`tools.approval.save_permanent_allowlist` path.
* **Hardline commands are never proposed** — anything matched by
:func:`tools.approval.detect_hardline_command` is dropped outright.
* **Destructive / privilege / credential / obfuscation classes are never
proposed**, no matter how often they were approved. ``rm -rf build/``
approved 100 times still never yields an ``rm`` allowlist entry. Only
benign, recoverable classes (container lifecycle, git force push, service
restarts, hermes self-management, …) are eligible.
* **Dangerous root binaries never become globs** (``rm *``, ``sudo *`` …).
"""
from __future__ import annotations
import json
import re
import sqlite3
import time
from dataclasses import dataclass, field
from pathlib import Path
from typing import Iterable, Iterator, Optional
# ---------------------------------------------------------------------------
# Safety exclusions
# ---------------------------------------------------------------------------
# Dangerous-class descriptions matching ANY of these are never proposed,
# regardless of approval frequency. Matched case-insensitively against the
# pattern-key/description strings produced by tools.approval's
# DANGEROUS_PATTERNS / execution-flag findings. Deliberately conservative:
# a benign class accidentally excluded costs the user one manual config edit;
# a destructive class accidentally proposed costs them data.
_UNSAFE_CLASS_PATTERNS = [
r"delete", # recursive delete, find -delete, branch force delete, ...
r"\brm\b", # xargs with rm, find -exec rm
r"destro", # git reset --hard (destroys ...), destructive
r"wipe",
r"format", # format filesystem
r"\bdisk\b",
r"block device",
r"fork bomb",
r"kill (?:all )?process", # force/regex/all process kills
r"kill all",
r"self-termination",
r"\bsudo\b",
r"privilege",
r"credential",
r"\bssh\b",
r"shell.rc",
r"system config",
r"system file",
r"\bsql\b", # SQL DROP / TRUNCATE / DELETE without WHERE
r"\bchown\b",
r"\bchmod\b",
r"writable", # world/other-writable permissions
r"overwrite",
r"in-place edit",
r"pipe", # pipe remote/decoded content to shell
r"obfuscation",
r"remote content",
r"remote script",
r"heredoc",
r"encoded", # PowerShell encoded command execution
r"command substitution",
r"process substitution",
r"\bdd\b",
r"shutdown",
r"reboot",
r"hardline",
]
_UNSAFE_CLASS_RE = re.compile("|".join(_UNSAFE_CLASS_PATTERNS), re.IGNORECASE)
# Root binaries that must never anchor a proposed command glob, even if the
# class survived the description filter. Prefix match for the mkfs family.
_UNSAFE_ROOT_BINARIES = {
"rm", "rmdir", "unlink", "shred", "dd", "fdisk", "parted", "wipefs",
"sudo", "doas", "su", "chmod", "chown", "chgrp",
"kill", "killall", "pkill",
"halt", "shutdown", "reboot", "poweroff", "init",
"del", "format", "truncate", "mkswap",
}
_UNSAFE_ROOT_PREFIXES = ("mkfs",)
# Substrings in a role='tool' result that mean the command did NOT execute
# with user consent (blocked, denied, timed out, or still pending). Kept in
# sync with the message templates in tools/approval.py.
_BLOCK_MARKERS = (
"BLOCKED (hardline)",
"BLOCKED: User denied",
"BLOCKED: Action ",
"BLOCKED: Command flagged as dangerous",
"BLOCKED: approval required",
"BLOCKED: Failed to send approval request",
"The user has NOT consented",
"Asking the user for approval",
"approval_required",
"BLOCKED by user deny rule",
)
@dataclass
class Proposal:
"""One ranked allowlist proposal."""
pattern: str # command glob ("git push *") or class key
kind: str # "glob" | "class"
count: int = 0
classes: set = field(default_factory=set)
examples: list = field(default_factory=list)
def add_example(self, command: str) -> None:
short = command.strip()
if len(short) > 100:
short = short[:97] + "..."
if short not in self.examples and len(self.examples) < 3:
self.examples.append(short)
# ---------------------------------------------------------------------------
# Scan: session DB -> (command, class description) records
# ---------------------------------------------------------------------------
def default_db_path() -> Path:
from hermes_constants import get_hermes_home
return get_hermes_home() / "state.db"
def _connect_readonly(db_path: Path) -> sqlite3.Connection:
uri = f"file:{db_path}?mode=ro"
return sqlite3.connect(uri, uri=True)
def _iter_terminal_calls(
con: sqlite3.Connection, since_ts: float
) -> Iterator[tuple[str, str]]:
"""Yield ``(tool_call_id, command)`` for every terminal tool call."""
cur = con.execute(
"SELECT tool_calls FROM messages "
"WHERE role='assistant' AND tool_calls IS NOT NULL "
"AND tool_calls LIKE '%terminal%' AND timestamp >= ?",
(since_ts,),
)
while True:
rows = cur.fetchmany(2000)
if not rows:
break
for (raw,) in rows:
try:
calls = json.loads(raw)
except (TypeError, ValueError):
continue
if not isinstance(calls, list):
continue
for call in calls:
if not isinstance(call, dict):
continue
fn = call.get("function") or {}
if fn.get("name") != "terminal":
continue
try:
args = json.loads(fn.get("arguments") or "{}")
except (TypeError, ValueError):
continue
command = args.get("command")
if isinstance(command, str) and command.strip():
yield (call.get("id") or "", command)
def _blocked_tool_call_ids(con: sqlite3.Connection, since_ts: float) -> set:
"""Collect tool_call_ids whose result shows the command never ran freely."""
blocked: set = set()
cur = con.execute(
"SELECT tool_call_id, content FROM messages "
"WHERE role='tool' AND tool_call_id IS NOT NULL AND timestamp >= ? "
"AND (content LIKE '%BLOCKED%' OR content LIKE '%approval%')",
(since_ts,),
)
while True:
rows = cur.fetchmany(2000)
if not rows:
break
for tool_call_id, content in rows:
if not content:
continue
if any(marker in content for marker in _BLOCK_MARKERS):
blocked.add(tool_call_id)
return blocked
def scan_approval_history(
db_path: Optional[Path] = None, days: int = 90
) -> list[tuple[str, str]]:
"""Return ``(command, dangerous_class_description)`` records mined from
the session DB — dangerous-classified terminal commands that actually
executed (i.e. carried an implied user approval).
"""
from tools.approval import detect_dangerous_command, detect_hardline_command
path = Path(db_path) if db_path else default_db_path()
if not path.exists():
return []
since_ts = 0.0 if days <= 0 else time.time() - days * 86400
records: list[tuple[str, str]] = []
con = _connect_readonly(path)
try:
blocked = _blocked_tool_call_ids(con, since_ts)
for tool_call_id, command in _iter_terminal_calls(con, since_ts):
if tool_call_id in blocked:
continue
is_hardline, _desc = detect_hardline_command(command)
if is_hardline:
# Hardline commands are unconditionally blocked at runtime;
# never mine them (defense in depth against stale DB rows).
continue
is_dangerous, _key, description = detect_dangerous_command(command)
if not is_dangerous:
continue
records.append((command, description))
finally:
con.close()
return records
# ---------------------------------------------------------------------------
# Normalize -> aggregate -> rank -> exclude
# ---------------------------------------------------------------------------
def normalize_command(command: str) -> str:
"""Fold user/hermes home prefixes and collapse whitespace.
Reuses tools.approval's home-folding machinery so proposals are portable
across machines/users (``/home/alice/x`` -> ``~/x``).
"""
from tools.approval import (
_rewrite_resolved_hermes_home,
_rewrite_resolved_user_home,
)
folded = _rewrite_resolved_user_home(_rewrite_resolved_hermes_home(command))
return " ".join(folded.split())
def is_unsafe_class(description: str) -> bool:
"""True when a dangerous-class description must never be proposed."""
return bool(_UNSAFE_CLASS_RE.search(description or ""))
def _unsafe_root_binary(token: str) -> bool:
tok = token.lower().rsplit("/", 1)[-1]
if tok in _UNSAFE_ROOT_BINARIES:
return True
return any(tok.startswith(p) for p in _UNSAFE_ROOT_PREFIXES)
def derive_glob(normalized: str) -> Optional[str]:
"""Derive a narrow command glob (``git push *``) from a simple command.
Returns None for compound commands (shell operators — the runtime
allowlist matcher refuses those anyway) and for commands anchored on an
unsafe root binary.
"""
from tools.approval import _has_allowlist_shell_operator
if _has_allowlist_shell_operator(normalized):
return None
tokens = normalized.split()
if not tokens:
return None
if _unsafe_root_binary(tokens[0]):
return None
if len(tokens) == 1:
return tokens[0]
second = tokens[1]
if second.startswith("-") or any(ch in second for ch in "*?[$"):
return f"{tokens[0]} *"
return f"{tokens[0]} {second} *"
def build_proposals(
records: Iterable[tuple[str, str]],
existing: Optional[set] = None,
min_count: int = 2,
limit: int = 20,
) -> list[Proposal]:
"""Aggregate scan records into a ranked, safety-filtered proposal list.
Grain: a command glob (``git push *``) for simple commands; the
dangerous-class description itself (the same key an interactive
``[a]lways`` answer persists) for compound commands where no safe glob
can be derived.
"""
existing = existing or set()
by_pattern: dict[tuple[str, str], Proposal] = {}
for command, description in records:
if is_unsafe_class(description):
continue
normalized = normalize_command(command)
glob = derive_glob(normalized)
if glob is not None:
key = (glob, "glob")
else:
key = (description, "class")
pattern, kind = key
if pattern in existing:
continue
proposal = by_pattern.get(key)
if proposal is None:
proposal = by_pattern[key] = Proposal(pattern=pattern, kind=kind)
proposal.count += 1
proposal.classes.add(description)
proposal.add_example(normalized)
ranked = [p for p in by_pattern.values() if p.count >= max(min_count, 1)]
ranked.sort(key=lambda p: (-p.count, p.pattern))
return ranked[: max(limit, 1)]
# ---------------------------------------------------------------------------
# Apply / render
# ---------------------------------------------------------------------------
def parse_apply_indices(spec: str, total: int) -> list[int]:
"""Parse ``"1,3"`` into validated zero-based indices."""
indices: list[int] = []
for part in (spec or "").split(","):
part = part.strip()
if not part:
continue
try:
n = int(part)
except ValueError:
raise ValueError(f"invalid selection {part!r} — expected numbers like 1,3")
if n < 1 or n > total:
raise ValueError(f"selection {n} out of range (1..{total})")
if (n - 1) not in indices:
indices.append(n - 1)
if not indices:
raise ValueError("no valid selections in --apply")
return indices
def apply_proposals(proposals: list[Proposal], indices: list[int]) -> set:
"""Merge chosen proposal patterns into command_allowlist and persist."""
import tools.approval as approval_module
merged = set(approval_module.load_permanent_allowlist())
for idx in indices:
merged.add(proposals[idx].pattern)
approval_module.save_permanent_allowlist(merged)
# Keep the in-process allowlist consistent so a long-lived process sees
# the new entries immediately (mirrors the interactive 'always' path).
approval_module.load_permanent(merged)
return merged
def _render_text(proposals: list[Proposal], days: int) -> None:
window = "all history" if days <= 0 else f"last {days} days"
if not proposals:
print(
f"No allowlist candidates found in approval history ({window}).\n"
"Either nothing dangerous was approved often enough "
"(see --min-count/--days), or the approved classes are "
"excluded for safety."
)
return
print(f"Proposed command_allowlist additions (from approval history, {window}):\n")
for i, p in enumerate(proposals, 1):
kind = " (class key)" if p.kind == "class" else ""
print(f" {i}. {p.pattern} — approved {p.count}x{kind}")
for cls in sorted(p.classes):
print(f" class: {cls}")
for ex in p.examples:
print(f" e.g. {ex}")
print(
"\nNothing has been changed. Apply selected entries with:\n"
" hermes approvals suggest --apply 1,3\n"
"Entries are merged into command_allowlist in ~/.hermes/config.yaml."
)
def suggest_command(args) -> int:
"""Entry point for ``hermes approvals suggest``."""
db_path = Path(args.db) if getattr(args, "db", None) else default_db_path()
days = getattr(args, "days", 90)
if not db_path.exists():
print(f"Session database not found: {db_path}")
return 1
import tools.approval as approval_module
existing = set(approval_module.load_permanent_allowlist())
records = scan_approval_history(db_path, days=days)
proposals = build_proposals(
records,
existing=existing,
min_count=getattr(args, "min_count", 2),
limit=getattr(args, "limit", 20),
)
apply_spec = getattr(args, "apply_indices", None)
if apply_spec:
try:
indices = parse_apply_indices(apply_spec, len(proposals))
except ValueError as exc:
print(f"--apply error: {exc}")
return 1
merged = apply_proposals(proposals, indices)
applied = [proposals[i].pattern for i in indices]
if getattr(args, "json", False):
print(json.dumps({"applied": applied, "allowlist_size": len(merged)}))
else:
print("Added to command_allowlist:")
for pattern in applied:
print(f" + {pattern}")
print(f"\ncommand_allowlist now has {len(merged)} entries "
"(~/.hermes/config.yaml).")
return 0
if getattr(args, "json", False):
payload = {
"db": str(db_path),
"days": days,
"proposals": [
{
"n": i,
"pattern": p.pattern,
"kind": p.kind,
"count": p.count,
"classes": sorted(p.classes),
"examples": p.examples,
}
for i, p in enumerate(proposals, 1)
],
}
print(json.dumps(payload, indent=2))
return 0
_render_text(proposals, days)
return 0
def approvals_command(args) -> int:
"""Dispatch ``hermes approvals <subcommand>``."""
sub = getattr(args, "approvals_command", None)
if sub == "suggest":
return suggest_command(args)
print(
"usage: hermes approvals <subcommand>\n"
"\n"
"subcommands:\n"
" suggest Mine past approval decisions into a proposed\n"
" command_allowlist (dry by default; --apply N,M to merge)\n"
"\n"
"Run `hermes approvals suggest -h` for details."
)
return 1