Split sign.sh into two pieces

chrome/installer/mac/sign_app.sh.in

-#!/bin/sh
+#!/bin/bash -p
 
 # Copyright (c) 2009 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 application.  Inner components are signed as needed,
-# then the outermost bundle is signed, and everything is verified.
+# Using codesign, sign the application. After signing, the signatures on the
+# inner bundle components are verified, and the application's own signature is
+# verified. Inner bundle components are expected to be signed before this
+# script is called. See sign_versioned_dir.sh.
 
-set -e
+set -eu
 
-if [ $# -ne 3 ] ; then
-  echo "usage: ${0} APP_PATH CODESIGN_KEYCHAIN CODESIGN_ID" >& 2
+# Environment sanitization. Set a known-safe PATH. Clear environment variables
+# that might impact the interpreter's operation. The |bash -p| invocation
+# on the #! line takes the bite out of BASH_ENV, ENV, and SHELLOPTS (among
+# other features), but clearing them here ensures that they won't impact any
+# shell scripts used as utility programs. SHELLOPTS is read-only and can't be
+# unset, only unexported.
+export PATH="/usr/bin:/bin:/usr/sbin:/sbin"
+unset BASH_ENV CDPATH ENV GLOBIGNORE IFS POSIXLY_CORRECT
+export -n SHELLOPTS
+
+ME="$(basename "${0}")"
+readonly ME
+
+if [[ ${#} -ne 3 ]]; then
+  echo "usage: ${ME} app_path codesign_keychain codesign_id" >& 2
   exit 1
 fi
 
-APP_PATH="${1}"
-CODESIGN_KEYCHAIN="${2}"
-CODESIGN_ID="${3}"
+app_path="${1}"
+codesign_keychain="${2}"
+codesign_id="${3}"
 
 # Use custom resource rules for the browser application.
-BROWSER_APP_RULES="$(dirname "${0}")/app_resource_rules.plist"
+script_dir="$(dirname "${0}")"
+browser_app_rules="${script_dir}/app_resource_rules.plist"
 
-# An .app bundle to be signed can be signed directly.  Normally, signging a
-# framework bundle requires that each version within be signed individually.
-# http://developer.apple.com/mac/library/technotes/tn2007/tn2206.html#TNTAG13
-# In Chrome's case, the framework bundle is unversioned, so it too can be
-# signed directly.  See copy_framework_unversioned.
+versioned_dir="${app_path}/Contents/Versions/@VERSION@"
 
-BROWSER_APP="${APP_PATH}"
-FRAMEWORK="${BROWSER_APP}/Contents/Versions/@VERSION@/@MAC_PRODUCT_NAME@ Framework.framework"
-HELPER_APP="${BROWSER_APP}/Contents/Versions/@VERSION@/@MAC_PRODUCT_NAME@ Helper.app"
+browser_app="${app_path}"
+framework="${versioned_dir}/@MAC_PRODUCT_NAME@ Framework.framework"
+helper_app="${versioned_dir}/@MAC_PRODUCT_NAME@ Helper.app"
 
-echo "${0}: signing..."
+codesign -s "${codesign_id}" --keychain "${codesign_keychain}" \
+    "${browser_app}" --resource-rules "${browser_app_rules}"
 
-# Sign the outer .app last so that its seal includes the signed inner
-# components.
-
-codesign -s "${CODESIGN_ID}" --keychain "${CODESIGN_KEYCHAIN}" "${FRAMEWORK}"
-codesign -s "${CODESIGN_ID}" --keychain "${CODESIGN_KEYCHAIN}" "${HELPER_APP}"
-codesign -s "${CODESIGN_ID}" --keychain "${CODESIGN_KEYCHAIN}" \
-    "${BROWSER_APP}" --resource-rules "${BROWSER_APP_RULES}"
-
-# Verify everything to ensure that signing the outer bundle didn't break an
-# inner bundle.
-
-echo "${0}: verifying..."
-
-codesign -v "${FRAMEWORK}"
-codesign -v "${HELPER_APP}"
-codesign -v "${BROWSER_APP}"
+# Verify everything. Check the framework and helper app to make sure that the
+# signatures are present and weren't altered by the signing process.
+codesign -v "${framework}"
+codesign -v "${helper_app}"
+codesign -v "${browser_app}"