refactor(security): extract safe-bin policy and dedupe tests

This commit is contained in:
Peter Steinberger
2026-02-19 14:23:19 +01:00
parent 0e85380e56
commit 2d485cd47a
3 changed files with 365 additions and 406 deletions

View File

@@ -1,4 +1,5 @@
import path from "node:path";
import type { ExecAllowlistEntry } from "./exec-approvals.js";
import {
DEFAULT_SAFE_BINS,
analyzeShellCommand,
@@ -10,26 +11,13 @@ import {
type CommandResolution,
type ExecCommandSegment,
} from "./exec-approvals-analysis.js";
import type { ExecAllowlistEntry } from "./exec-approvals.js";
import {
SAFE_BIN_GENERIC_PROFILE,
SAFE_BIN_PROFILES,
validateSafeBinArgv,
} from "./exec-safe-bin-policy.js";
import { isTrustedSafeBinPath } from "./exec-safe-bin-trust.js";
function isPathLikeToken(value: string): boolean {
const trimmed = value.trim();
if (!trimmed) {
return false;
}
if (trimmed === "-") {
return false;
}
if (trimmed.startsWith("./") || trimmed.startsWith("../") || trimmed.startsWith("~")) {
return true;
}
if (trimmed.startsWith("/")) {
return true;
}
return /^[A-Za-z]:[\\/]/.test(trimmed);
}
export function normalizeSafeBins(entries?: string[]): Set<string> {
if (!Array.isArray(entries)) {
return new Set();
@@ -47,259 +35,6 @@ export function resolveSafeBins(entries?: string[] | null): Set<string> {
return normalizeSafeBins(entries ?? []);
}
function hasGlobToken(value: string): boolean {
// Safe bins are stdin-only; globbing is both surprising and a historical bypass vector.
// Note: we still harden execution-time expansion separately.
return /[*?[\]]/.test(value);
}
type SafeBinProfile = {
minPositional?: number;
maxPositional?: number;
valueFlags?: ReadonlySet<string>;
blockedFlags?: ReadonlySet<string>;
};
const NO_FLAGS = new Set<string>();
const SAFE_BIN_GENERIC_PROFILE: SafeBinProfile = {};
const SAFE_BIN_PROFILES: Record<string, SafeBinProfile> = {
jq: {
maxPositional: 1,
valueFlags: new Set([
"--arg",
"--argjson",
"--argstr",
"--argfile",
"--rawfile",
"--slurpfile",
"--from-file",
"--library-path",
"-L",
"-f",
]),
blockedFlags: new Set([
"--argfile",
"--rawfile",
"--slurpfile",
"--from-file",
"--library-path",
"-L",
"-f",
]),
},
grep: {
maxPositional: 1,
valueFlags: new Set([
"--regexp",
"--file",
"--max-count",
"--after-context",
"--before-context",
"--context",
"--devices",
"--directories",
"--binary-files",
"--exclude",
"--exclude-from",
"--include",
"--label",
"-e",
"-f",
"-m",
"-A",
"-B",
"-C",
"-D",
"-d",
]),
blockedFlags: new Set([
"--file",
"--exclude-from",
"--dereference-recursive",
"--directories",
"--recursive",
"-f",
"-d",
"-r",
"-R",
]),
},
cut: {
maxPositional: 0,
valueFlags: new Set([
"--bytes",
"--characters",
"--fields",
"--delimiter",
"--output-delimiter",
"-b",
"-c",
"-f",
"-d",
]),
},
sort: {
maxPositional: 0,
valueFlags: new Set([
"--key",
"--field-separator",
"--buffer-size",
"--temporary-directory",
"--compress-program",
"--parallel",
"--batch-size",
"--random-source",
"--files0-from",
"--output",
"-k",
"-t",
"-S",
"-T",
"-o",
]),
blockedFlags: new Set(["--files0-from", "--output", "-o"]),
},
uniq: {
maxPositional: 0,
valueFlags: new Set([
"--skip-fields",
"--skip-chars",
"--check-chars",
"--group",
"-f",
"-s",
"-w",
]),
},
head: {
maxPositional: 0,
valueFlags: new Set(["--lines", "--bytes", "-n", "-c"]),
},
tail: {
maxPositional: 0,
valueFlags: new Set([
"--lines",
"--bytes",
"--sleep-interval",
"--max-unchanged-stats",
"--pid",
"-n",
"-c",
]),
},
tr: {
minPositional: 1,
maxPositional: 2,
},
wc: {
maxPositional: 0,
valueFlags: new Set(["--files0-from"]),
blockedFlags: new Set(["--files0-from"]),
},
};
function isSafeLiteralToken(value: string): boolean {
if (!value || value === "-") {
return true;
}
return !hasGlobToken(value) && !isPathLikeToken(value);
}
function validateSafeBinArgv(args: string[], profile: SafeBinProfile): boolean {
const valueFlags = profile.valueFlags ?? NO_FLAGS;
const blockedFlags = profile.blockedFlags ?? NO_FLAGS;
const positional: string[] = [];
for (let i = 0; i < args.length; i += 1) {
const token = args[i];
if (!token) {
continue;
}
if (token === "--") {
for (let j = i + 1; j < args.length; j += 1) {
const rest = args[j];
if (!rest || rest === "-") {
continue;
}
if (!isSafeLiteralToken(rest)) {
return false;
}
positional.push(rest);
}
break;
}
if (token === "-") {
continue;
}
if (!token.startsWith("-")) {
if (!isSafeLiteralToken(token)) {
return false;
}
positional.push(token);
continue;
}
if (token.startsWith("--")) {
const eqIndex = token.indexOf("=");
const flag = eqIndex > 0 ? token.slice(0, eqIndex) : token;
if (blockedFlags.has(flag)) {
return false;
}
if (eqIndex > 0) {
if (!isSafeLiteralToken(token.slice(eqIndex + 1))) {
return false;
}
continue;
}
if (!valueFlags.has(flag)) {
continue;
}
const value = args[i + 1];
if (!value || !isSafeLiteralToken(value)) {
return false;
}
i += 1;
continue;
}
let consumedValue = false;
for (let j = 1; j < token.length; j += 1) {
const flag = `-${token[j]}`;
if (blockedFlags.has(flag)) {
return false;
}
if (!valueFlags.has(flag)) {
continue;
}
const inlineValue = token.slice(j + 1);
if (inlineValue) {
if (!isSafeLiteralToken(inlineValue)) {
return false;
}
} else {
const value = args[i + 1];
if (!value || !isSafeLiteralToken(value)) {
return false;
}
i += 1;
}
consumedValue = true;
break;
}
if (!consumedValue && hasGlobToken(token)) {
return false;
}
}
const minPositional = profile.minPositional ?? 0;
if (positional.length < minPositional) {
return false;
}
if (typeof profile.maxPositional === "number" && positional.length > profile.maxPositional) {
return false;
}
return true;
}
export function isSafeBinUsage(params: {
argv: string[];
resolution: CommandResolution | null;
@@ -321,9 +56,7 @@ export function isSafeBinUsage(params: {
if (!execName) {
return false;
}
const matchesSafeBin =
params.safeBins.has(execName) ||
(process.platform === "win32" && params.safeBins.has(path.parse(execName).name));
const matchesSafeBin = params.safeBins.has(execName);
if (!matchesSafeBin) {
return false;
}

View File

@@ -0,0 +1,272 @@
function isPathLikeToken(value: string): boolean {
const trimmed = value.trim();
if (!trimmed) {
return false;
}
if (trimmed === "-") {
return false;
}
if (trimmed.startsWith("./") || trimmed.startsWith("../") || trimmed.startsWith("~")) {
return true;
}
if (trimmed.startsWith("/")) {
return true;
}
return /^[A-Za-z]:[\\/]/.test(trimmed);
}
function hasGlobToken(value: string): boolean {
// Safe bins are stdin-only; globbing is both surprising and a historical bypass vector.
// Note: we still harden execution-time expansion separately.
return /[*?[\]]/.test(value);
}
export type SafeBinProfile = {
minPositional?: number;
maxPositional?: number;
valueFlags?: ReadonlySet<string>;
blockedFlags?: ReadonlySet<string>;
};
const NO_FLAGS = new Set<string>();
export const SAFE_BIN_GENERIC_PROFILE: SafeBinProfile = {};
export const SAFE_BIN_PROFILES: Record<string, SafeBinProfile> = {
jq: {
maxPositional: 1,
valueFlags: new Set([
"--arg",
"--argjson",
"--argstr",
"--argfile",
"--rawfile",
"--slurpfile",
"--from-file",
"--library-path",
"-L",
"-f",
]),
blockedFlags: new Set([
"--argfile",
"--rawfile",
"--slurpfile",
"--from-file",
"--library-path",
"-L",
"-f",
]),
},
grep: {
maxPositional: 1,
valueFlags: new Set([
"--regexp",
"--file",
"--max-count",
"--after-context",
"--before-context",
"--context",
"--devices",
"--directories",
"--binary-files",
"--exclude",
"--exclude-from",
"--include",
"--label",
"-e",
"-f",
"-m",
"-A",
"-B",
"-C",
"-D",
"-d",
]),
blockedFlags: new Set([
"--file",
"--exclude-from",
"--dereference-recursive",
"--directories",
"--recursive",
"-f",
"-d",
"-r",
"-R",
]),
},
cut: {
maxPositional: 0,
valueFlags: new Set([
"--bytes",
"--characters",
"--fields",
"--delimiter",
"--output-delimiter",
"-b",
"-c",
"-f",
"-d",
]),
},
sort: {
maxPositional: 0,
valueFlags: new Set([
"--key",
"--field-separator",
"--buffer-size",
"--temporary-directory",
"--compress-program",
"--parallel",
"--batch-size",
"--random-source",
"--files0-from",
"--output",
"-k",
"-t",
"-S",
"-T",
"-o",
]),
blockedFlags: new Set(["--files0-from", "--output", "-o"]),
},
uniq: {
maxPositional: 0,
valueFlags: new Set([
"--skip-fields",
"--skip-chars",
"--check-chars",
"--group",
"-f",
"-s",
"-w",
]),
},
head: {
maxPositional: 0,
valueFlags: new Set(["--lines", "--bytes", "-n", "-c"]),
},
tail: {
maxPositional: 0,
valueFlags: new Set([
"--lines",
"--bytes",
"--sleep-interval",
"--max-unchanged-stats",
"--pid",
"-n",
"-c",
]),
},
tr: {
minPositional: 1,
maxPositional: 2,
},
wc: {
maxPositional: 0,
valueFlags: new Set(["--files0-from"]),
blockedFlags: new Set(["--files0-from"]),
},
};
function isSafeLiteralToken(value: string): boolean {
if (!value || value === "-") {
return true;
}
return !hasGlobToken(value) && !isPathLikeToken(value);
}
export function validateSafeBinArgv(args: string[], profile: SafeBinProfile): boolean {
const valueFlags = profile.valueFlags ?? NO_FLAGS;
const blockedFlags = profile.blockedFlags ?? NO_FLAGS;
const positional: string[] = [];
for (let i = 0; i < args.length; i += 1) {
const token = args[i];
if (!token) {
continue;
}
if (token === "--") {
for (let j = i + 1; j < args.length; j += 1) {
const rest = args[j];
if (!rest || rest === "-") {
continue;
}
if (!isSafeLiteralToken(rest)) {
return false;
}
positional.push(rest);
}
break;
}
if (token === "-") {
continue;
}
if (!token.startsWith("-")) {
if (!isSafeLiteralToken(token)) {
return false;
}
positional.push(token);
continue;
}
if (token.startsWith("--")) {
const eqIndex = token.indexOf("=");
const flag = eqIndex > 0 ? token.slice(0, eqIndex) : token;
if (blockedFlags.has(flag)) {
return false;
}
if (eqIndex > 0) {
if (!isSafeLiteralToken(token.slice(eqIndex + 1))) {
return false;
}
continue;
}
if (!valueFlags.has(flag)) {
continue;
}
const value = args[i + 1];
if (!value || !isSafeLiteralToken(value)) {
return false;
}
i += 1;
continue;
}
let consumedValue = false;
for (let j = 1; j < token.length; j += 1) {
const flag = `-${token[j]}`;
if (blockedFlags.has(flag)) {
return false;
}
if (!valueFlags.has(flag)) {
continue;
}
const inlineValue = token.slice(j + 1);
if (inlineValue) {
if (!isSafeLiteralToken(inlineValue)) {
return false;
}
} else {
const value = args[i + 1];
if (!value || !isSafeLiteralToken(value)) {
return false;
}
i += 1;
}
consumedValue = true;
break;
}
if (!consumedValue && hasGlobToken(token)) {
return false;
}
}
const minPositional = profile.minPositional ?? 0;
if (positional.length < minPositional) {
return false;
}
if (typeof profile.maxPositional === "number" && positional.length > profile.maxPositional) {
return false;
}
return true;
}