feat: plan 16 P2 batch 1 (SEC-13 SSRF, SEC-27 log-escape, SEC-28 path-traversal)

- SEC-13 (M-09): SSRF allowlist on provider-usage-fetch (always block non-http(s)
  schemes; enforced mode blocks internal/link-local IPs + non-allowlisted hosts,
  dev keeps loopback mocks); dashboard refuses non-loopback bind in enforced mode.
- SEC-27 (X-02): casan-log strips ESC/CSI + CR/LF (terminal-escape + fake-log-line
  injection) while keeping tab and visible text.
- SEC-28 (X-04): new path-guard.sh — realpath resolve + reject symlink/.. escapes
  outside the allowed root.

Verify: SEC-13 6/0, SEC-27 3/0, SEC-28 4/0, adversarial 44/44, run-casan4 0-FAIL.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
thanhnv
2026-07-06 22:39:18 +09:00
co-authored by Claude Opus 4.8
parent 3432ae59e1
commit 8c06a55aed
11 changed files with 273 additions and 5 deletions
@@ -24,8 +24,12 @@ casan_log() {
local lvl="$1" comp="$2"
shift 2
[ "$(casan_log_num "$lvl")" -le "$CASAN_LOG_THRESHOLD" ] || return 0
# SEC-27 (X-02): log messages carry attacker-influenced data (action names, tool
# output snippets). Strip control chars — ESC/CSI (terminal-escape injection that
# rewrites a reviewer's screen) and CR/LF (fake-log-line injection) — keeping tab.
local msg; msg="$(printf '%s' "$*" | tr -d '\000-\010\012-\037\177')"
printf '[%s] %s [%s] %s\n' \
"$(printf '%s' "$lvl" | tr '[:lower:]' '[:upper:]')" \
"$(date -u +"%Y-%m-%dT%H:%M:%SZ")" \
"$comp" "$*" >&2
"$comp" "$msg" >&2
}
@@ -104,6 +104,10 @@ run "phase-sec20-toolchain" bash "$TESTS/phase-sec20-tests.sh"
run "phase-sec21-model-budget" bash "$TESTS/phase-sec21-tests.sh"
run "phase-sec07-approval" bash "$TESTS/phase-sec07-tests.sh"
run "phase-sec10-agent-identity" bash "$TESTS/phase-sec10-tests.sh"
# Plan-16 P2 (depth / hardening)
run "phase-sec13-ssrf" bash "$TESTS/phase-sec13-tests.sh"
run "phase-sec27-log-controlchar" bash "$TESTS/phase-sec27-tests.sh"
run "phase-sec28-path-traversal" bash "$TESTS/phase-sec28-tests.sh"
# ARCH-02: coverage cannot silently drop; ARCH-01: harness/policy cannot silently
# drift. Both SKIP cleanly when no manifest is provisioned (non-strict dev/CI).
@@ -77,4 +77,11 @@ BIND = os.environ.get("CASAN_DASHBOARD_BIND", "127.0.0.1")
if __name__ == "__main__":
# SEC-13 (M-09): the dashboard has no auth, so binding to all interfaces exposes
# it to the network. In enforced mode refuse a non-loopback bind (fail-closed);
# a real deployment must front it with TLS + auth (Plan-07 TIER 2), not 0.0.0.0.
_enforced = os.environ.get("CASAN_PROFILE") == "prod" or os.environ.get("CASAN_DASHBOARD_STRICT") == "1"
if _enforced and BIND not in ("127.0.0.1", "::1", "localhost"):
sys.stderr.write(f"DASHBOARD_BIND_REFUSED bind={BIND} (loopback only in enforced mode)\n")
raise SystemExit(1)
HTTPServer((BIND, PORT), Handler).serve_forever()
@@ -0,0 +1,39 @@
#!/usr/bin/env bash
set -uo pipefail
# CASAN Plan-16 SEC-28 (X-04) — path-traversal / symlink guard.
#
# A tool that takes a file path as input/output can be pointed at an arbitrary
# location via `..` or a symlink (e.g. a symlink named "input.txt" -> /etc/passwd),
# reading or writing outside the workspace. This resolves the REAL path (following
# every symlink) and refuses anything that escapes the allowed root.
#
# Usage: path-guard.sh <path> [allowed-root] (default root: repo workspace)
# Exit: 0 inside the root, 1 outside / unresolvable.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
TARGET="${1:-}"
ROOT="${2:-$PROJECT_ROOT}"
if [[ -z "$TARGET" ]]; then
echo "Usage: path-guard.sh <path> [allowed-root]" >&2
exit 64
fi
python3 - "$TARGET" "$ROOT" <<'PY'
import os
import sys
target, root = sys.argv[1], sys.argv[2]
# realpath resolves symlinks in every existing path component and normalizes "..";
# for a not-yet-created leaf it resolves the existing parent chain.
real_target = os.path.realpath(target)
real_root = os.path.realpath(root)
if real_target == real_root or real_target.startswith(real_root + os.sep):
print(f"PATH_OK {real_target}")
sys.exit(0)
sys.stderr.write(f"PATH_ESCAPES_ROOT target={target} real={real_target} root={real_root}\n")
sys.exit(1)
PY
@@ -24,6 +24,52 @@ PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
OUT="${2:-$PROJECT_ROOT/.specify/logs/level5/provider-usage.jsonl}"
mkdir -p "$(dirname "$OUT")"
# SEC-13 (M-09): SSRF guard on the fetch URL. ALWAYS reject non-http(s) schemes
# (file://, gopher://, dict://, … metadata exfil). In enforced mode additionally
# require the host to be in the provider allowlist and block internal/link-local
# IPs — dev keeps loopback mocks working (http://127.0.0.1 test servers).
if ! python3 - "$API_URL" <<'PY'
import ipaddress, os, sys
from urllib.parse import urlparse
url = sys.argv[1]
u = urlparse(url)
scheme = (u.scheme or "").lower()
host = (u.hostname or "").lower()
enforced = os.environ.get("CASAN_PROFILE") == "prod" or os.environ.get("CASAN_SSRF_STRICT") == "1"
allow = [h.strip().lower() for h in os.environ.get(
"CASAN_PROVIDER_HOST_ALLOWLIST", "api.openai.com,api.anthropic.com").split(",") if h.strip()]
def die(reason):
sys.stderr.write(f"PROVIDER_URL_REJECTED {reason} url={url}\n")
sys.exit(1)
if scheme not in ("http", "https"):
die(f"scheme_not_allowed:{scheme or 'none'}") # blocks file:// et al (all modes)
if not host:
die("no_host")
if enforced:
if scheme != "https":
die("plaintext_http_not_allowed_in_prod")
if host in ("localhost",) or host.endswith(".internal") or host.endswith(".local"):
die(f"internal_host:{host}")
try:
ip = ipaddress.ip_address(host)
if (ip.is_private or ip.is_loopback or ip.is_link_local or ip.is_reserved
or ip.is_multicast or ip.is_unspecified):
die(f"internal_ip:{host}")
except ValueError:
pass # a hostname, not a literal IP
if allow and host not in allow:
die(f"host_not_in_allowlist:{host}")
sys.exit(0)
PY
then
echo "PROVIDER_API_SSRF_BLOCKED url=$API_URL (telemetry NOT imported)" >&2
exit 1
fi
BODY="$(mktemp)"
trap 'rm -f "$BODY"' EXIT
@@ -0,0 +1,61 @@
#!/usr/bin/env bash
set -uo pipefail
# CASAN Plan-16 SEC-13 (M-09) — SSRF allowlist on outbound fetch + dashboard bind.
#
# provider-usage-fetch curled an arbitrary URL (SSRF: internal/link-local/file://),
# and the no-auth dashboard could bind 0.0.0.0. Proves:
# * file:// (and other non-http schemes) are ALWAYS rejected,
# * dev keeps loopback mocks working (http://127.0.0.1 → unreachable, not blocked),
# * enforced mode blocks loopback, metadata IPs, and non-allowlisted hosts,
# * the dashboard refuses a non-loopback bind in enforced mode.
#
# Deterministic; hermetic; no real network egress.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
S="$PROJECT_ROOT/.specify/scripts/bash"
FETCH="$S/provider-usage-fetch.sh"
WORK="$(mktemp -d)"
trap 'rm -rf "$WORK"' EXIT
OUT="$WORK/o.jsonl"
PASS=0; FAIL=0
pass() { echo "PASS: $1"; PASS=$((PASS + 1)); }
fail() { echo "FAIL: $1"; FAIL=$((FAIL + 1)); }
out_of() { set +e; "$@" 2>&1 >/dev/null; set -e 2>/dev/null || true; }
echo "===== Plan-16 SEC-13: SSRF allowlist + dashboard bind ====="
# 1) file:// always rejected (any mode).
out_of bash "$FETCH" "file:///etc/passwd" "$OUT" | grep -q "PROVIDER_API_SSRF_BLOCKED\|scheme_not_allowed" \
&& pass "file:// scheme rejected (all modes)" || fail "file:// not rejected"
# 2) dev + loopback mock: NOT ssrf-blocked (reaches curl → unreachable).
O="$(out_of bash "$FETCH" "http://127.0.0.1:59991/usage" "$OUT")"
if echo "$O" | grep -q "PROVIDER_API_SSRF_BLOCKED"; then
fail "dev loopback mock wrongly SSRF-blocked (breaks provider telemetry test)"
else
pass "dev loopback mock allowed to reach fetch (backward compatible)"
fi
# 3) enforced + loopback → blocked.
out_of env CASAN_SSRF_STRICT=1 bash "$FETCH" "https://127.0.0.1/usage" "$OUT" | grep -q "SSRF_BLOCKED\|internal_ip" \
&& pass "enforced: loopback blocked" || fail "enforced loopback not blocked"
# 4) enforced + cloud metadata IP → blocked.
out_of env CASAN_SSRF_STRICT=1 bash "$FETCH" "https://169.254.169.254/latest/meta-data" "$OUT" | grep -q "SSRF_BLOCKED\|internal_ip" \
&& pass "enforced: link-local metadata IP blocked" || fail "metadata IP not blocked"
# 5) enforced + non-allowlisted host → blocked.
out_of env CASAN_SSRF_STRICT=1 bash "$FETCH" "https://evil.example.com/usage" "$OUT" | grep -q "SSRF_BLOCKED\|host_not_in_allowlist" \
&& pass "enforced: non-allowlisted host blocked" || fail "non-allowlisted host not blocked"
# 6) dashboard refuses non-loopback bind in enforced mode.
out_of env CASAN_DASHBOARD_STRICT=1 CASAN_DASHBOARD_BIND=0.0.0.0 CASAN_DASHBOARD_PORT=0 \
python3 "$S/dashboard-server.py" | grep -q "DASHBOARD_BIND_REFUSED" \
&& pass "enforced: dashboard refuses 0.0.0.0 bind" || fail "dashboard allowed 0.0.0.0 in enforced mode"
echo ""
echo "===== SEC-13 SUMMARY: PASS=$PASS FAIL=$FAIL ====="
[[ "$FAIL" -eq 0 ]] || exit 1
@@ -0,0 +1,45 @@
#!/usr/bin/env bash
set -uo pipefail
# CASAN Plan-16 SEC-27 (X-02) — strip control/ANSI chars from log output.
#
# Log messages carry attacker-influenced data (action names, tool-output snippets).
# A raw ESC/CSI sequence can rewrite a reviewer's terminal; a raw CR/LF can inject a
# fake log line. casan_log now strips control chars (keeping tab). Proves the ESC
# byte and embedded newlines are removed while the visible text survives.
#
# Deterministic; no model/network.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
PASS=0; FAIL=0
pass() { echo "PASS: $1"; PASS=$((PASS + 1)); }
fail() { echo "FAIL: $1"; FAIL=$((FAIL + 1)); }
echo "===== Plan-16 SEC-27: log control-char stripping ====="
# shellcheck source=/dev/null
source "$PROJECT_ROOT/.specify/scripts/bash/casan-log.sh"
PAYLOAD="$(printf 'start\033[31mRED\033[0m\nFAKE [ERROR] injected-audit-line')"
OUT="$(casan_log error test "$PAYLOAD" 2>&1)"
if printf '%s' "$OUT" | od -An -c | grep -q '033'; then
fail "ESC byte survived into the log (terminal-escape injection)"
else
pass "ESC byte stripped from log output"
fi
LINES="$(printf '%s\n' "$OUT" | grep -c .)"
[[ "$LINES" -eq 1 ]] \
&& pass "embedded newline stripped — no injected second log line" \
|| fail "log emitted $LINES lines (newline injection)"
printf '%s' "$OUT" | grep -q "start" && printf '%s' "$OUT" | grep -q "RED" \
&& pass "visible text preserved (only control bytes removed)" \
|| fail "visible text lost"
echo ""
echo "===== SEC-27 SUMMARY: PASS=$PASS FAIL=$FAIL ====="
[[ "$FAIL" -eq 0 ]] || exit 1
@@ -0,0 +1,47 @@
#!/usr/bin/env bash
set -uo pipefail
# CASAN Plan-16 SEC-28 (X-04) — path-traversal / symlink guard.
#
# path-guard.sh resolves the REAL path (following symlinks, normalizing "..") and
# refuses anything that escapes the allowed root — so a tool file argument cannot be
# a symlink to /etc/passwd or a ../.. escape. Proves in-root paths pass and escapes
# (via .. and via symlink) are rejected.
#
# Deterministic; hermetic.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"
PG="$PROJECT_ROOT/.specify/scripts/bash/path-guard.sh"
WORK="$(mktemp -d)"
trap 'rm -rf "$WORK"' EXIT
PASS=0; FAIL=0
pass() { echo "PASS: $1"; PASS=$((PASS + 1)); }
fail() { echo "FAIL: $1"; FAIL=$((FAIL + 1)); }
rc_of() { set +e; "$@" >/dev/null 2>&1; echo $?; set -e 2>/dev/null || true; }
echo "===== Plan-16 SEC-28: path-traversal / symlink guard ====="
mkdir -p "$WORK/root/sub"
[[ "$(rc_of bash "$PG" "$WORK/root/sub/out.txt" "$WORK/root")" -eq 0 ]] \
&& pass "in-root path accepted" || fail "in-root path rejected"
[[ "$(rc_of bash "$PG" "$WORK/root/../../etc/passwd" "$WORK/root")" -ne 0 ]] \
&& pass "'..' escape rejected" || fail "'..' escape accepted"
# A symlink inside the root that points OUTSIDE it must be rejected.
ln -s /etc/passwd "$WORK/root/evil-link"
[[ "$(rc_of bash "$PG" "$WORK/root/evil-link" "$WORK/root")" -ne 0 ]] \
&& pass "symlink escaping root rejected (realpath resolves the target)" \
|| fail "symlink escape accepted"
# A symlink that stays inside the root is fine.
echo hi > "$WORK/root/sub/real.txt"
ln -s "$WORK/root/sub/real.txt" "$WORK/root/ok-link"
[[ "$(rc_of bash "$PG" "$WORK/root/ok-link" "$WORK/root")" -eq 0 ]] \
&& pass "in-root symlink accepted" || fail "in-root symlink rejected"
echo ""
echo "===== SEC-28 SUMMARY: PASS=$PASS FAIL=$FAIL ====="
[[ "$FAIL" -eq 0 ]] || exit 1
@@ -96,6 +96,10 @@
"sha256": "099c81a0a37b51137dbf328dbe2ef778226d0716b97660d083c1fcc6a4aecd19",
"checks": 5
},
"phase-sec13-tests.sh": {
"sha256": "64d67fa0ccf9c199848323e8fb6207f0cbc9608f6e256a0a7337b371c0451b43",
"checks": 6
},
"phase-sec16-tests.sh": {
"sha256": "3d826ca4f5c8f98837cc70846b8e2f2f83d5a598c2a5907795e8b9cc9db448c2",
"checks": 6
@@ -116,6 +120,14 @@
"sha256": "303503fb3670be7d1b3c2737451eff64e7f140e940d2ae16188f686af0992dfa",
"checks": 4
},
"phase-sec27-tests.sh": {
"sha256": "1096f622ef010aecd44b9545c72f32a3b31009c3b250f4424d92018d74830e87",
"checks": 3
},
"phase-sec28-tests.sh": {
"sha256": "8f082c85b80bf899ea1911e8165e28c14f691e1ac3605953cd1b968ee295e556",
"checks": 4
},
"phase-selfimprove-tests.sh": {
"sha256": "e91db1af16e30b18def130553f27f05691ff5540eca0593ca5e07f624c0ef938",
"checks": 7
@@ -161,6 +173,6 @@
"checks": 10
}
},
"total_checks": 343,
"suite_count": 40
"total_checks": 356,
"suite_count": 43
}
@@ -1 +1 @@
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