chrome/installer/mac/sign_versioned_dir.sh.in

#!/bin/bash -p

# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# Using codesign, sign the contents of the versioned directory. Namely, this
# includes the framework and helper app. After signing, the signatures are
# verified.

set -eu

# Environment sanitization. Set a known-safe PATH. Clear environment variables
# that might impact the interpreter's operation. The |bash -p| invocation
# on the #! line takes the bite out of BASH_ENV, ENV, and SHELLOPTS (among
# other features), but clearing them here ensures that they won't impact any
# shell scripts used as utility programs. SHELLOPTS is read-only and can't be
# unset, only unexported.
export PATH="/usr/bin:/bin:/usr/sbin:/sbin"
unset BASH_ENV CDPATH ENV GLOBIGNORE IFS POSIXLY_CORRECT
export -n SHELLOPTS

ME="$(basename "${0}")"
readonly ME

script_dir="$(dirname "${0}")"
source "${script_dir}/variables.sh"

codesign_display_and_verify() {
  args=("${@}")
  path=${args[0]}

  # --verbose can go up to 6 for --display, but that just shows the hash of each
  # ordinary page in the executable, which is more noise than anything else.
  codesign --display --verbose=5 -r- "${path}"
  codesign --verify --verbose=6 "${args[@]:1}" "${path}"
}

if [[ ${#} -ne 3 && ${#} -ne 4 ]]; then
  echo "usage: ${ME} app_path codesign_keychain codesign_id \
[--development]" >& 2
  exit 1
fi

app_path="${1}"
codesign_keychain="${2}"
codesign_id="${3}"
is_development=

if [[ ${#} == 4 && ${4} == "--development" ]]; then
  is_development=1
fi

codesign_with_options() {
  path=${1}
  options=${2}
  requirement_identifier=${3}

  codesign_cmd=(
    codesign --sign "${codesign_id}" --keychain "${codesign_keychain}"
    "${path}"
  )

  if [[ "${requirement_identifier}" = "app_mode_loader" ]]; then
    codesign_cmd+=( --identifier "${requirement_identifier}" )
  fi

  if [[ -n "${options}" ]]; then
    codesign_cmd+=( --options "${options}" )
  fi

  if [[ -z "${is_development}" ]]; then
    requirement="designated => identifier \"${requirement_identifier}\" \
${requirement_suffix}"
    codesign_cmd+=( -r="${requirement}" )
  fi
  "${codesign_cmd[@]}"
}

versioned_dir="${app_path}/Contents/Versions/@VERSION@"

# To sign an .app bundle that contains nested code, the nested components
# themselves must be signed. Each of these components is signed below. Note
# that unless a framework has multiple versions (which is discouraged), signing
# the entire framework is equivalent to signing the Current version.
# https://developer.apple.com/library/content/technotes/tn2206/_index.html#//apple_ref/doc/uid/DTS40007919-CH1-TNTAG13

framework="${versioned_dir}/@MAC_PRODUCT_NAME@ Framework.framework"
notification_service="${framework}/XPCServices/AlertNotificationService.xpc"
crashpad_handler="${framework}/Helpers/crashpad_handler"
helper_app="${versioned_dir}/@MAC_PRODUCT_NAME@ Helper.app"
app_mode_loader_app="${framework}/Resources/app_mode_loader.app"
app_mode_loader="${app_mode_loader_app}/Contents/MacOS/app_mode_loader"
widevine_plugin="${framework}/Libraries/WidevineCdm/_platform_specific/mac_x64/widevinecdmadapter.plugin"

codesign_with_options "${crashpad_handler}" \
                      "${enforcement_flags_helpers}" \
                      "crashpad_handler"

# The app mode loader bundle is modified dynamically at runtime. Just sign the
# executable, which shouldn't change. In order to do this, the executable needs
# to be copied out of the bundle, signed, and then copied back in. The resulting
# bundle's signature won't validate normally, but if the executable file is
# verified in isolation or with --ignore-resources, it will.
app_mode_loader_tmp="$(mktemp -t app_mode_loader)"
cp "${app_mode_loader}" "${app_mode_loader_tmp}"

codesign_with_options "${app_mode_loader_tmp}" \
                      "${enforcement_flags_helpers}" \
                      "app_mode_loader"

cp "${app_mode_loader_tmp}" "${app_mode_loader}"
rm -f "${app_mode_loader_tmp}"

xpc_plist="${notification_service}/Contents/Info"
xpc_bundle_id="$(__CFPREFERENCES_AVOID_DAEMON=1 defaults read \
    "${xpc_plist}" "CFBundleIdentifier")"

codesign_with_options "${notification_service}" \
                      "${enforcement_flags_helpers}" \
                      "${xpc_bundle_id}"

# Only sign widevine plugin if it is present in the bundle.
# ${enforcement_flags*} are meaningless for dynamic libraries.
if [[ -f "${widevine_plugin}" ]]; then
  codesign_with_options "${widevine_plugin}" "" "widevinecdmadapter"
fi

# The framework is a dylib, so ${enforcement_flags_helpers} are meaningless.
codesign_with_options "${framework}" "" "com.google.Chrome.framework"

codesign_with_options "${helper_app}" \
                      "${enforcement_flags_app}" \
                      "com.google.Chrome.helper"

if [[ -f "${widevine_plugin}" ]]; then
  codesign_display_and_verify "${widevine_plugin}"
fi

codesign_display_and_verify "${crashpad_handler}" --deep
codesign_display_and_verify "${app_mode_loader}" --ignore-resources
codesign_display_and_verify "${notification_service}" --deep
# The framework contains KeystoneRegistration.framework, which uses
# custom resource rules, so use --no-strict to verify.
codesign_display_and_verify "${framework}" --deep --no-strict
codesign_display_and_verify "${framework}" --strict
codesign_display_and_verify "${helper_app}" --deep