feat(security): URL query param + userinfo + form body redaction

Port from nearai/ironclaw#2529.

Hermes already has broad value-shape coverage in agent/redact.py
(30+ vendor prefixes, JWTs, DB connstrs, etc.) but missed three
key-name-based patterns that catch opaque tokens without recognizable
prefixes:

1. URL query params - OAuth callback codes (?code=...),
   access_token, refresh_token, signature, etc. These are opaque and
   won't match any prefix regex. Now redacted by parameter NAME.

2. URL userinfo (https://user:pass@host) - for non-DB schemes. DB
   schemes were already handled by _DB_CONNSTR_RE.

3. Form-urlencoded body (k=v pairs joined by ampersands) -
   conservative, only triggers on clean pure-form inputs with no
   other text.

Sensitive key allowlist matches ironclaw's (exact case-insensitive,
NOT substring - so token_count and session_id pass through).

Tests: +20 new test cases across 3 test classes. All 75 redact tests
pass; gateway/test_pii_redaction and tools/test_browser_secret_exfil
also green.

Known pre-existing limitation: _ENV_ASSIGN_RE greedy match swallows
whole all-caps ENV-style names + trailing text when followed by
another assignment. Left untouched here (out of scope); URL query
redaction handles the lowercase case.

agent/redact.py

@@ -13,6 +13,48 @@ import re
 
 logger = logging.getLogger(__name__)
 
+# Sensitive query-string parameter names (case-insensitive exact match).
+# Ported from nearai/ironclaw#2529 — catches tokens whose values don't match
+# any known vendor prefix regex (e.g. opaque tokens, short OAuth codes).
+_SENSITIVE_QUERY_PARAMS = frozenset({
+    "access_token",
+    "refresh_token",
+    "id_token",
+    "token",
+    "api_key",
+    "apikey",
+    "client_secret",
+    "password",
+    "auth",
+    "jwt",
+    "session",
+    "secret",
+    "key",
+    "code",           # OAuth authorization codes
+    "signature",      # pre-signed URL signatures
+    "x-amz-signature",
+})
+
+# Sensitive form-urlencoded / JSON body key names (case-insensitive exact match).
+# Exact match, NOT substring — "token_count" and "session_id" must NOT match.
+# Ported from nearai/ironclaw#2529.
+_SENSITIVE_BODY_KEYS = frozenset({
+    "access_token",
+    "refresh_token",
+    "id_token",
+    "token",
+    "api_key",
+    "apikey",
+    "client_secret",
+    "password",
+    "auth",
+    "jwt",
+    "secret",
+    "private_key",
+    "authorization",
+    "key",
+})
+
 # Snapshot at import time so runtime env mutations (e.g. LLM-generated
 # `export HERMES_REDACT_SECRETS=false`) cannot disable redaction mid-session.
 _REDACT_ENABLED = os.getenv("HERMES_REDACT_SECRETS", "").lower() not in ("0", "false", "no", "off")
@@ -108,6 +150,30 @@ _DISCORD_MENTION_RE = re.compile(r"<@!?(\d{17,20})>")
 # Negative lookahead prevents matching hex strings or identifiers
 _SIGNAL_PHONE_RE = re.compile(r"(\+[1-9]\d{6,14})(?![A-Za-z0-9])")
 
+# URLs containing query strings — matches `scheme://...?...[# or end]`.
+# Used to scan text for URLs whose query params may contain secrets.
+# Ported from nearai/ironclaw#2529.
+_URL_WITH_QUERY_RE = re.compile(
+    r"(https?|wss?|ftp)://"          # scheme
+    r"([^\s/?#]+)"                    # authority (may include userinfo)
+    r"([^\s?#]*)"                     # path
+    r"\?([^\s#]+)"                    # query (required)
+    r"(#\S*)?",                       # optional fragment
+)
+
+# URLs containing userinfo — `scheme://user:password@host` for ANY scheme
+# (not just DB protocols already covered by _DB_CONNSTR_RE above).
+# Catches things like `https://user:token@api.example.com/v1/foo`.
+_URL_USERINFO_RE = re.compile(
+    r"(https?|wss?|ftp)://([^/\s:@]+):([^/\s@]+)@",
+)
+
+# Form-urlencoded body detection: conservative — only applies when the entire
+# text looks like a query string (k=v&k=v pattern with no newlines).
+_FORM_BODY_RE = re.compile(
+    r"^[A-Za-z_][A-Za-z0-9_.-]*=[^&\s]*(?:&[A-Za-z_][A-Za-z0-9_.-]*=[^&\s]*)+$"
+)
+
 # Compile known prefix patterns into one alternation
 _PREFIX_RE = re.compile(
     r"(?<![A-Za-z0-9_-])(" + "|".join(_PREFIX_PATTERNS) + r")(?![A-Za-z0-9_-])"
@@ -121,6 +187,72 @@ def _mask_token(token: str) -> str:
     return f"{token[:6]}...{token[-4:]}"
 
 
+def _redact_query_string(query: str) -> str:
+    """Redact sensitive parameter values in a URL query string.
+
+    Handles `k=v&k=v` format. Sensitive keys (case-insensitive) have values
+    replaced with `***`. Non-sensitive keys pass through unchanged.
+    Empty or malformed pairs are preserved as-is.
+    """
+    if not query:
+        return query
+    parts = []
+    for pair in query.split("&"):
+        if "=" not in pair:
+            parts.append(pair)
+            continue
+        key, _, value = pair.partition("=")
+        if key.lower() in _SENSITIVE_QUERY_PARAMS:
+            parts.append(f"{key}=***")
+        else:
+            parts.append(pair)
+    return "&".join(parts)
+
+
+def _redact_url_query_params(text: str) -> str:
+    """Scan text for URLs with query strings and redact sensitive params.
+
+    Catches opaque tokens that don't match vendor prefix regexes, e.g.
+    `https://example.com/cb?code=ABC123&state=xyz` → `...?code=***&state=xyz`.
+    """
+    def _sub(m: re.Match) -> str:
+        scheme = m.group(1)
+        authority = m.group(2)
+        path = m.group(3)
+        query = _redact_query_string(m.group(4))
+        fragment = m.group(5) or ""
+        return f"{scheme}://{authority}{path}?{query}{fragment}"
+    return _URL_WITH_QUERY_RE.sub(_sub, text)
+
+
+def _redact_url_userinfo(text: str) -> str:
+    """Strip `user:password@` from HTTP/WS/FTP URLs.
+
+    DB protocols (postgres, mysql, mongodb, redis, amqp) are handled
+    separately by `_DB_CONNSTR_RE`.
+    """
+    return _URL_USERINFO_RE.sub(
+        lambda m: f"{m.group(1)}://{m.group(2)}:***@",
+        text,
+    )
+
+
+def _redact_form_body(text: str) -> str:
+    """Redact sensitive values in a form-urlencoded body.
+
+    Only applies when the entire input looks like a pure form body
+    (k=v&k=v with no newlines, no other text). Single-line non-form
+    text passes through unchanged. This is a conservative pass — the
+    `_redact_url_query_params` function handles embedded query strings.
+    """
+    if not text or "\n" in text or "&" not in text:
+        return text
+    # The body-body form check is strict: only trigger on clean k=v&k=v.
+    if not _FORM_BODY_RE.match(text.strip()):
+        return text
+    return _redact_query_string(text.strip())
+
+
 def redact_sensitive_text(text: str) -> str:
     """Apply all redaction patterns to a block of text.
 
@@ -173,6 +305,16 @@ def redact_sensitive_text(text: str) -> str:
     # JWT tokens (eyJ... — base64-encoded JSON headers)
     text = _JWT_RE.sub(lambda m: _mask_token(m.group(0)), text)
 
+    # URL userinfo (http(s)://user:pass@host) — redact for non-DB schemes.
+    # DB schemes are handled above by _DB_CONNSTR_RE.
+    text = _redact_url_userinfo(text)
+
+    # URL query params containing opaque tokens (?access_token=…&code=…)
+    text = _redact_url_query_params(text)
+
+    # Form-urlencoded bodies (only triggers on clean k=v&k=v inputs).
+    text = _redact_form_body(text)
+
     # Discord user/role mentions (<@snowflake_id>)
     text = _DISCORD_MENTION_RE.sub(lambda m: f"<@{'!' if '!' in m.group(0) else ''}***>", text)