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fix: ignore all NODE_ envs from foreign parent in node process
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zcbenz committed Jan 5, 2024
1 parent 783f23b commit 74a1350
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Showing 8 changed files with 115 additions and 17 deletions.
1 change: 1 addition & 0 deletions filenames.gni
Expand Up @@ -643,6 +643,7 @@ filenames = {
"shell/common/node_includes.h",
"shell/common/node_util.cc",
"shell/common/node_util.h",
"shell/common/node_util_mac.mm",
"shell/common/options_switches.cc",
"shell/common/options_switches.h",
"shell/common/platform_util.cc",
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21 changes: 11 additions & 10 deletions shell/app/node_main.cc
Expand Up @@ -31,6 +31,7 @@
#include "shell/common/gin_helper/dictionary.h"
#include "shell/common/node_bindings.h"
#include "shell/common/node_includes.h"
#include "shell/common/node_util.h"

#if BUILDFLAG(IS_WIN)
#include "chrome/child/v8_crashpad_support_win.h"
Expand Down Expand Up @@ -107,8 +108,12 @@ int NodeMain(int argc, char* argv[]) {

auto os_env = base::Environment::Create();
bool node_options_enabled = electron::fuses::IsNodeOptionsEnabled();
if (!node_options_enabled) {
os_env->UnSetVar("NODE_OPTIONS");
}

#if BUILDFLAG(IS_MAC)
if (node_options_enabled && os_env->HasVar("NODE_OPTIONS")) {
if (!ProcessSignatureIsSameWithCurrentApp(getppid())) {
// On macOS, it is forbidden to run sandboxed app with custom arguments
// from another app, i.e. args are discarded in following call:
// exec("Sandboxed.app", ["--custom-args-will-be-discarded"])
Expand All @@ -117,18 +122,14 @@ int NodeMain(int argc, char* argv[]) {
// exec("Electron.app", {env: {ELECTRON_RUN_AS_NODE: "1",
// NODE_OPTIONS: "--require 'bad.js'"}})
// To prevent Electron apps from being used to work around macOS security
// restrictions, when NODE_OPTIONS is passed it will be checked whether
// this process is invoked by its own app.
if (!ProcessBelongToCurrentApp(getppid())) {
LOG(ERROR) << "NODE_OPTIONS is disabled because this process is invoked "
"by other apps.";
node_options_enabled = false;
// restrictions, when the parent process is not part of the app bundle, all
// environment variables starting with NODE_ will be removed.
if (util::UnsetAllNodeEnvs()) {
LOG(ERROR) << "Node.js environment variables are disabled because this "
"process is invoked by other apps.";
}
}
#endif // BUILDFLAG(IS_MAC)
if (!node_options_enabled) {
os_env->UnSetVar("NODE_OPTIONS");
}

#if BUILDFLAG(IS_WIN)
v8_crashpad_support::SetUp();
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62 changes: 60 additions & 2 deletions shell/common/mac/codesign_util.cc
Expand Up @@ -5,15 +5,59 @@

#include "shell/common/mac/codesign_util.h"

#include "base/mac/foundation_util.h"
#include "base/mac/mac_logging.h"
#include "base/mac/scoped_cftyperef.h"
#include "third_party/abseil-cpp/absl/types/optional.h"

#include <CoreFoundation/CoreFoundation.h>
#include <Security/Security.h>

namespace electron {

bool ProcessBelongToCurrentApp(pid_t pid) {
absl::optional<bool> IsUnsignedOrAdHocSigned(SecCodeRef code) {
base::ScopedCFTypeRef<SecStaticCodeRef> static_code;
OSStatus status = SecCodeCopyStaticCode(code, kSecCSDefaultFlags,
static_code.InitializeInto());
if (status == errSecCSUnsigned) {
return true;
}
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyStaticCode";
return absl::optional<bool>();
}
// Copy the signing info from the SecStaticCodeRef.
base::ScopedCFTypeRef<CFDictionaryRef> signing_info;
status =
SecCodeCopySigningInformation(static_code.get(), kSecCSSigningInformation,
signing_info.InitializeInto());
if (status != errSecSuccess) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopySigningInformation";
return absl::optional<bool>();
}
// Look up the code signing flags. If the flags are absent treat this as
// unsigned. This decision is consistent with the StaticCode source:
// https://github.com/apple-oss-distributions/Security/blob/Security-60157.40.30.0.1/OSX/libsecurity_codesigning/lib/StaticCode.cpp#L2270
CFNumberRef signing_info_flags =
base::mac::GetValueFromDictionary<CFNumberRef>(signing_info.get(),
kSecCodeInfoFlags);
if (!signing_info_flags) {
return true;
}
// Using a long long to extract the value from the CFNumberRef to be
// consistent with how it was packed by Security.framework.
// https://github.com/apple-oss-distributions/Security/blob/Security-60157.40.30.0.1/OSX/libsecurity_utilities/lib/cfutilities.h#L262
long long flags;
if (!CFNumberGetValue(signing_info_flags, kCFNumberLongLongType, &flags)) {
LOG(ERROR) << "CFNumberGetValue";
return absl::optional<bool>();
}
if (static_cast<uint32_t>(flags) & kSecCodeSignatureAdhoc) {
return true;
}
return false;
}

bool ProcessSignatureIsSameWithCurrentApp(pid_t pid) {
// Get and check the code signature of current app.
base::ScopedCFTypeRef<SecCodeRef> self_code;
OSStatus status =
Expand All @@ -22,6 +66,15 @@ bool ProcessBelongToCurrentApp(pid_t pid) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyGuestWithAttributes";
return false;
}
absl::optional<bool> not_signed = IsUnsignedOrAdHocSigned(self_code.get());
if (!not_signed.has_value()) {
// Error happened.
return false;
}
if (not_signed.value()) {
// Current app is not signed.
return true;
}
// Get the code signature of process.
base::ScopedCFTypeRef<CFNumberRef> process_cf(
CFNumberCreate(nullptr, kCFNumberIntType, &pid));
Expand All @@ -46,9 +99,14 @@ bool ProcessBelongToCurrentApp(pid_t pid) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCopyDesignatedRequirement";
return false;
}
DCHECK(self_requirement.get());
// Check whether the process meets the signature requirement of current app.
status = SecCodeCheckValidity(process_code.get(), kSecCSDefaultFlags,
self_requirement.get());
if (status != errSecSuccess && status != errSecCSReqFailed) {
OSSTATUS_LOG(ERROR, status) << "SecCodeCheckValidity";
return false;
}
return status == errSecSuccess;
}

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11 changes: 8 additions & 3 deletions shell/common/mac/codesign_util.h
Expand Up @@ -10,9 +10,14 @@

namespace electron {

// Given a pid, check if the process belongs to current app by comparing its
// code signature with current app.
bool ProcessBelongToCurrentApp(pid_t pid);
// Given a pid, return true if the process has the same code signature with
// with current app.
// This API returns true if current app is not signed or ad-hoc signed, because
// checking code signature is meaningless in this case, and failing the
// signature check would break some features with unsigned binary (for example,
// process.send stops working in processes created by child_process.fork, due
// to the NODE_CHANNEL_ID env getting removed).
bool ProcessSignatureIsSameWithCurrentApp(pid_t pid);

} // namespace electron

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7 changes: 7 additions & 0 deletions shell/common/node_util.h
Expand Up @@ -7,6 +7,7 @@

#include <vector>

#include "build/build_config.h"
#include "v8/include/v8.h"

namespace node {
Expand All @@ -27,6 +28,12 @@ v8::MaybeLocal<v8::Value> CompileAndCall(
std::vector<v8::Local<v8::Value>>* arguments,
node::Environment* optional_env);

#if BUILDFLAG(IS_MAC)
// Unset all environment variables that start with NODE_. Return false if there
// is no node env at all.
bool UnsetAllNodeEnvs();
#endif

} // namespace electron::util

#endif // ELECTRON_SHELL_COMMON_NODE_UTIL_H_
23 changes: 23 additions & 0 deletions shell/common/node_util_mac.mm
@@ -0,0 +1,23 @@
// Copyright (c) 2023 Microsoft, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.

#include "shell/common/node_util.h"

#include <Foundation/Foundation.h>

namespace electron::util {

bool UnsetAllNodeEnvs() {
bool has_unset = false;
for (NSString* env in NSProcessInfo.processInfo.environment) {
if (![env hasPrefix:@"NODE_"])
continue;
const char* name = [[env componentsSeparatedByString:@"="][0] UTF8String];
unsetenv(name);
has_unset = true;
}
return has_unset;
}

} // namespace electron::util
5 changes: 4 additions & 1 deletion spec/fixtures/api/fork-with-node-options.js
Expand Up @@ -2,11 +2,14 @@ const { execFileSync } = require('node:child_process');
const path = require('node:path');

const fixtures = path.resolve(__dirname, '..');
const failJs = path.join(fixtures, 'module', 'fail.js');

const env = {
ELECTRON_RUN_AS_NODE: 'true',
// Process will exit with 1 if NODE_OPTIONS is accepted.
NODE_OPTIONS: `--require "${path.join(fixtures, 'module', 'fail.js')}"`
NODE_OPTIONS: `--require "${failJs}"`,
// Try bypassing the check with NODE_REPL_EXTERNAL_MODULE.
NODE_REPL_EXTERNAL_MODULE: failJs
};
// Provide a lower cased NODE_OPTIONS in case some code ignores case sensitivity
// when reading NODE_OPTIONS.
Expand Down
2 changes: 1 addition & 1 deletion spec/node-spec.ts
Expand Up @@ -674,7 +674,7 @@ describe('node feature', () => {
});

const script = path.join(fixtures, 'api', 'fork-with-node-options.js');
const nodeOptionsWarning = 'NODE_OPTIONS is disabled because this process is invoked by other apps';
const nodeOptionsWarning = 'Node.js environment variables are disabled because this process is invoked by other apps';

it('is disabled when invoked by other apps in ELECTRON_RUN_AS_NODE mode', async () => {
await withTempDirectory(async (dir) => {
Expand Down

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