hermes-agent/tests/tools/test_url_safety.py
kshitijk4poor d6ed35d047 feat(security): add global toggle to allow private/internal URL resolution
Adds security.allow_private_urls / HERMES_ALLOW_PRIVATE_URLS toggle so
users on OpenWrt routers, TUN-mode proxies (Clash/Mihomo/Sing-box),
corporate split-tunnel VPNs, and Tailscale networks — where DNS resolves
public domains to 198.18.0.0/15 or 100.64.0.0/10 — can use web_extract,
browser, vision URL fetching, and gateway media downloads.

Single toggle in tools/url_safety.py; all 23 is_safe_url() call sites
inherit automatically. Cached for process lifetime.

Cloud metadata endpoints stay ALWAYS blocked regardless of the toggle:
169.254.169.254 (AWS/GCP/Azure/DO/Oracle), 169.254.170.2 (AWS ECS task
IAM creds), 169.254.169.253 (Azure IMDS wire server), 100.100.100.200
(Alibaba), fd00:ec2::254 (AWS IPv6), the entire 169.254.0.0/16
link-local range, and the metadata.google.internal / metadata.goog
hostnames (checked pre-DNS so they can't be bypassed on networks where
those names resolve to local IPs).

Supersedes #3779 (narrower HERMES_ALLOW_RFC2544 for the same class of
users).

Co-authored-by: kshitijk4poor <82637225+kshitijk4poor@users.noreply.github.com>
2026-04-22 14:38:59 -07:00

395 lines
17 KiB
Python

"""Tests for SSRF protection in url_safety module."""
import socket
from unittest.mock import patch
from tools.url_safety import (
is_safe_url,
_is_blocked_ip,
_global_allow_private_urls,
_reset_allow_private_cache,
)
import ipaddress
import pytest
class TestIsSafeUrl:
def test_public_url_allowed(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("93.184.216.34", 0)),
]):
assert is_safe_url("https://example.com/image.png") is True
def test_localhost_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("127.0.0.1", 0)),
]):
assert is_safe_url("http://localhost:8080/secret") is False
def test_loopback_ip_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("127.0.0.1", 0)),
]):
assert is_safe_url("http://127.0.0.1/admin") is False
def test_private_10_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("10.0.0.1", 0)),
]):
assert is_safe_url("http://internal-service.local/api") is False
def test_private_172_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("172.16.0.1", 0)),
]):
assert is_safe_url("http://private.corp/data") is False
def test_private_192_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("192.168.1.1", 0)),
]):
assert is_safe_url("http://router.local") is False
def test_link_local_169_254_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("169.254.169.254", 0)),
]):
assert is_safe_url("http://169.254.169.254/latest/meta-data/") is False
def test_metadata_google_internal_blocked(self):
assert is_safe_url("http://metadata.google.internal/computeMetadata/v1/") is False
def test_ipv6_loopback_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(10, 1, 6, "", ("::1", 0, 0, 0)),
]):
assert is_safe_url("http://[::1]:8080/") is False
def test_dns_failure_blocked(self):
"""DNS failures now fail closed — block the request."""
with patch("socket.getaddrinfo", side_effect=socket.gaierror("Name resolution failed")):
assert is_safe_url("https://nonexistent.example.com") is False
def test_empty_url_blocked(self):
assert is_safe_url("") is False
def test_no_hostname_blocked(self):
assert is_safe_url("http://") is False
def test_public_ip_allowed(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("93.184.216.34", 0)),
]):
assert is_safe_url("https://example.com") is True
# ── New tests for hardened SSRF protection ──
def test_cgnat_100_64_blocked(self):
"""100.64.0.0/10 (CGNAT/Shared Address Space) is NOT covered by
ipaddress.is_private — must be blocked explicitly."""
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("100.64.0.1", 0)),
]):
assert is_safe_url("http://some-cgnat-host.example/") is False
def test_cgnat_100_127_blocked(self):
"""Upper end of CGNAT range (100.127.255.255)."""
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("100.127.255.254", 0)),
]):
assert is_safe_url("http://tailscale-peer.example/") is False
def test_multicast_blocked(self):
"""Multicast addresses (224.0.0.0/4) not caught by is_private."""
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("224.0.0.251", 0)),
]):
assert is_safe_url("http://mdns-host.local/") is False
def test_multicast_ipv6_blocked(self):
with patch("socket.getaddrinfo", return_value=[
(10, 1, 6, "", ("ff02::1", 0, 0, 0)),
]):
assert is_safe_url("http://[ff02::1]/") is False
def test_ipv4_mapped_ipv6_loopback_blocked(self):
"""::ffff:127.0.0.1 — IPv4-mapped IPv6 loopback."""
with patch("socket.getaddrinfo", return_value=[
(10, 1, 6, "", ("::ffff:127.0.0.1", 0, 0, 0)),
]):
assert is_safe_url("http://[::ffff:127.0.0.1]/") is False
def test_ipv4_mapped_ipv6_metadata_blocked(self):
"""::ffff:169.254.169.254 — IPv4-mapped IPv6 cloud metadata."""
with patch("socket.getaddrinfo", return_value=[
(10, 1, 6, "", ("::ffff:169.254.169.254", 0, 0, 0)),
]):
assert is_safe_url("http://[::ffff:169.254.169.254]/") is False
def test_unspecified_address_blocked(self):
"""0.0.0.0 — unspecified address, can bind to all interfaces."""
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("0.0.0.0", 0)),
]):
assert is_safe_url("http://0.0.0.0/") is False
def test_unexpected_error_fails_closed(self):
"""Unexpected exceptions should block, not allow."""
with patch("tools.url_safety.urlparse", side_effect=ValueError("bad url")):
assert is_safe_url("http://evil.com/") is False
def test_metadata_goog_blocked(self):
assert is_safe_url("http://metadata.goog/computeMetadata/v1/") is False
def test_ipv6_unique_local_blocked(self):
"""fc00::/7 — IPv6 unique local addresses."""
with patch("socket.getaddrinfo", return_value=[
(10, 1, 6, "", ("fd12::1", 0, 0, 0)),
]):
assert is_safe_url("http://[fd12::1]/internal") is False
def test_non_cgnat_100_allowed(self):
"""100.0.0.1 is NOT in CGNAT range (100.64.0.0/10), should be allowed."""
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("100.0.0.1", 0)),
]):
# 100.0.0.1 is a global IP, not in CGNAT range
assert is_safe_url("http://legit-host.example/") is True
def test_benchmark_ip_blocked_for_non_allowlisted_host(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("198.18.0.23", 0)),
]):
assert is_safe_url("https://example.com/file.jpg") is False
def test_qq_multimedia_hostname_allowed_with_benchmark_ip(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("198.18.0.23", 0)),
]):
assert is_safe_url("https://multimedia.nt.qq.com.cn/download?id=123") is True
def test_qq_multimedia_hostname_exception_is_exact_match(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("198.18.0.23", 0)),
]):
assert is_safe_url("https://sub.multimedia.nt.qq.com.cn/download?id=123") is False
def test_qq_multimedia_hostname_exception_requires_https(self):
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("198.18.0.23", 0)),
]):
assert is_safe_url("http://multimedia.nt.qq.com.cn/download?id=123") is False
def test_qq_multimedia_hostname_dns_failure_still_blocked(self):
with patch("socket.getaddrinfo", side_effect=socket.gaierror("Name resolution failed")):
assert is_safe_url("https://multimedia.nt.qq.com.cn/download?id=123") is False
class TestIsBlockedIp:
"""Direct tests for the _is_blocked_ip helper."""
@pytest.mark.parametrize("ip_str", [
"127.0.0.1", "10.0.0.1", "172.16.0.1", "192.168.1.1",
"169.254.169.254", "0.0.0.0", "224.0.0.1", "255.255.255.255",
"100.64.0.1", "100.100.100.100", "100.127.255.254", "198.18.0.23",
"::1", "fe80::1", "fc00::1", "fd12::1", "ff02::1",
"::ffff:127.0.0.1", "::ffff:169.254.169.254",
])
def test_blocked_ips(self, ip_str):
ip = ipaddress.ip_address(ip_str)
assert _is_blocked_ip(ip) is True, f"{ip_str} should be blocked"
@pytest.mark.parametrize("ip_str", [
"8.8.8.8", "93.184.216.34", "1.1.1.1", "100.0.0.1",
"2606:4700::1", "2001:4860:4860::8888",
])
def test_allowed_ips(self, ip_str):
ip = ipaddress.ip_address(ip_str)
assert _is_blocked_ip(ip) is False, f"{ip_str} should be allowed"
class TestGlobalAllowPrivateUrls:
"""Tests for the security.allow_private_urls config toggle."""
@pytest.fixture(autouse=True)
def _reset_cache(self):
"""Reset the module-level toggle cache before and after each test."""
_reset_allow_private_cache()
yield
_reset_allow_private_cache()
def test_default_is_false(self, monkeypatch):
"""Toggle defaults to False when no env var or config is set."""
monkeypatch.delenv("HERMES_ALLOW_PRIVATE_URLS", raising=False)
with patch("hermes_cli.config.read_raw_config", side_effect=Exception("no config")):
assert _global_allow_private_urls() is False
def test_env_var_true(self, monkeypatch):
"""HERMES_ALLOW_PRIVATE_URLS=true enables the toggle."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
assert _global_allow_private_urls() is True
def test_env_var_1(self, monkeypatch):
"""HERMES_ALLOW_PRIVATE_URLS=1 enables the toggle."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "1")
assert _global_allow_private_urls() is True
def test_env_var_yes(self, monkeypatch):
"""HERMES_ALLOW_PRIVATE_URLS=yes enables the toggle."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "yes")
assert _global_allow_private_urls() is True
def test_env_var_false(self, monkeypatch):
"""HERMES_ALLOW_PRIVATE_URLS=false keeps it disabled."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "false")
assert _global_allow_private_urls() is False
def test_config_security_section(self, monkeypatch):
"""security.allow_private_urls in config enables the toggle."""
monkeypatch.delenv("HERMES_ALLOW_PRIVATE_URLS", raising=False)
cfg = {"security": {"allow_private_urls": True}}
with patch("hermes_cli.config.read_raw_config", return_value=cfg):
assert _global_allow_private_urls() is True
def test_config_browser_fallback(self, monkeypatch):
"""browser.allow_private_urls works as legacy fallback."""
monkeypatch.delenv("HERMES_ALLOW_PRIVATE_URLS", raising=False)
cfg = {"browser": {"allow_private_urls": True}}
with patch("hermes_cli.config.read_raw_config", return_value=cfg):
assert _global_allow_private_urls() is True
def test_config_security_takes_precedence_over_browser(self, monkeypatch):
"""security section is checked before browser section."""
monkeypatch.delenv("HERMES_ALLOW_PRIVATE_URLS", raising=False)
cfg = {"security": {"allow_private_urls": True}, "browser": {"allow_private_urls": False}}
with patch("hermes_cli.config.read_raw_config", return_value=cfg):
assert _global_allow_private_urls() is True
def test_env_var_overrides_config(self, monkeypatch):
"""Env var takes priority over config."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "false")
cfg = {"security": {"allow_private_urls": True}}
with patch("hermes_cli.config.read_raw_config", return_value=cfg):
assert _global_allow_private_urls() is False
def test_result_is_cached(self, monkeypatch):
"""Second call uses cached result, doesn't re-read config."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
assert _global_allow_private_urls() is True
# Change env after first call — should still be True (cached)
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "false")
assert _global_allow_private_urls() is True
class TestAllowPrivateUrlsIntegration:
"""Integration tests: is_safe_url respects the global toggle."""
@pytest.fixture(autouse=True)
def _reset_cache(self):
_reset_allow_private_cache()
yield
_reset_allow_private_cache()
def test_private_ip_allowed_when_toggle_on(self, monkeypatch):
"""Private IPs pass is_safe_url when toggle is enabled."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("192.168.1.1", 0)),
]):
assert is_safe_url("http://router.local") is True
def test_benchmark_ip_allowed_when_toggle_on(self, monkeypatch):
"""198.18.x.x (benchmark/OpenWrt proxy range) passes when toggle is on."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("198.18.23.183", 0)),
]):
assert is_safe_url("https://nousresearch.com") is True
def test_cgnat_allowed_when_toggle_on(self, monkeypatch):
"""CGNAT range (100.64.0.0/10) passes when toggle is on."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("100.100.100.100", 0)),
]):
assert is_safe_url("http://tailscale-peer.example/") is True
def test_localhost_allowed_when_toggle_on(self, monkeypatch):
"""Even localhost passes when toggle is on."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("127.0.0.1", 0)),
]):
assert is_safe_url("http://localhost:8080/api") is True
# --- Cloud metadata always blocked regardless of toggle ---
def test_metadata_hostname_blocked_even_with_toggle(self, monkeypatch):
"""metadata.google.internal is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
assert is_safe_url("http://metadata.google.internal/computeMetadata/v1/") is False
def test_metadata_goog_blocked_even_with_toggle(self, monkeypatch):
"""metadata.goog is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
assert is_safe_url("http://metadata.goog/computeMetadata/v1/") is False
def test_metadata_ip_blocked_even_with_toggle(self, monkeypatch):
"""169.254.169.254 (AWS/GCP metadata IP) is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("169.254.169.254", 0)),
]):
assert is_safe_url("http://169.254.169.254/latest/meta-data/") is False
def test_metadata_ipv6_blocked_even_with_toggle(self, monkeypatch):
"""fd00:ec2::254 (AWS IPv6 metadata) is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(10, 1, 6, "", ("fd00:ec2::254", 0, 0, 0)),
]):
assert is_safe_url("http://[fd00:ec2::254]/latest/") is False
def test_ecs_metadata_blocked_even_with_toggle(self, monkeypatch):
"""169.254.170.2 (AWS ECS task metadata) is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("169.254.170.2", 0)),
]):
assert is_safe_url("http://169.254.170.2/v2/credentials") is False
def test_alibaba_metadata_blocked_even_with_toggle(self, monkeypatch):
"""100.100.100.200 (Alibaba Cloud metadata) is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("100.100.100.200", 0)),
]):
assert is_safe_url("http://100.100.100.200/latest/meta-data/") is False
def test_azure_wire_server_blocked_even_with_toggle(self, monkeypatch):
"""169.254.169.253 (Azure IMDS wire server) is ALWAYS blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("169.254.169.253", 0)),
]):
assert is_safe_url("http://169.254.169.253/") is False
def test_entire_link_local_blocked_even_with_toggle(self, monkeypatch):
"""Any 169.254.x.x address is ALWAYS blocked (entire link-local range)."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", return_value=[
(2, 1, 6, "", ("169.254.42.99", 0)),
]):
assert is_safe_url("http://169.254.42.99/anything") is False
def test_dns_failure_still_blocked_with_toggle(self, monkeypatch):
"""DNS failures are still blocked even with toggle on."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
with patch("socket.getaddrinfo", side_effect=socket.gaierror("fail")):
assert is_safe_url("https://nonexistent.example.com") is False
def test_empty_url_still_blocked_with_toggle(self, monkeypatch):
"""Empty URLs are still blocked."""
monkeypatch.setenv("HERMES_ALLOW_PRIVATE_URLS", "true")
assert is_safe_url("") is False