Download CRX file from Chrome Web Store

crx_download.sh

#!/usr/bin/env bash
#
# Download a Chrome extension from the webstore.
# Extract it to a specified path.
#
# Author: Werner Robitza

set -e

CHROME_VERSION="101.0.4951.57"

# ==============================================================================

usage() {
  echo "Usage: $0 [-h|--help] <extensionId> <outputPath>"
  echo
  echo "Download and extract a Chrome extension,"
  echo "creating a file with the extension ID and a .crx suffix."
  echo
  echo "Options:"
  echo "  -h, --help    Show this help message and exit"
}

# If there are no options, exit:
if [ $# -lt 1 ]; then
  usage
  exit 1
fi

if [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
  usage
  exit 0
fi

extensionId="$1"
outputPath="$2"

if [ -z "$extensionId" ]; then
  echo "Error: Chrome extension ID not specified."
  exit 1
fi

if [ -z "$outputPath" ]; then
  outputPath="$(pwd)"
fi

[ -n "$platformOs" ] || case "$OSTYPE" in
  *darwin*) platformOs="mac" ;;
  *openbsd*) platformOs="openbsd" ;;
  *linux* | *hurd* | *sua* | *interix* | *bsd* | *sunos* | *solaris* | *indiana* | *illumos* | *smartos*) platformOs="Linux" ;;
  *) echo "Platform unsupported!"; exit 1;;
esac

# if platform is Linux and we do not have the 7z binary, we need to install it
if [ "$platformOs" = "Linux" ] && ! [ -x "$(command -v 7z)" ]; then
  echo "Error: 7z binary not found. Please install 7z first via:"
  echo
  echo "  sudo apt-get install p7zip-full"
  exit 1
fi

arch="x86-64"
ARCH="$(uname -m)"
[ -n "$arch" ] || case "$ARCH" in
  *arm*) arch="arm" ;;
  "x86_64") arch="x86-64" ;;
esac

# ==============================================================================

crxDownloadUrl='https://clients2.google.com/service/update2/crx?response=redirect'
crxDownloadUrl="${crxDownloadUrl}&os=${platformOs}"
crxDownloadUrl="${crxDownloadUrl}&arch=${arch}"
crxDownloadUrl="${crxDownloadUrl}&os_arch=${arch}"
#crxDownloadUrl="${crxDownloadUrl}&nacl_arch=${arch}"
crxDownloadUrl="${crxDownloadUrl}&prod=chromecrx"
crxDownloadUrl="${crxDownloadUrl}&prodchannel=unknown"
crxDownloadUrl="${crxDownloadUrl}&prodversion=${CHROME_VERSION}"
crxDownloadUrl="${crxDownloadUrl}&acceptformat=crx3"
crxDownloadUrl="${crxDownloadUrl}&x=id%3D${extensionId}%26uc"

downloadFilePath="$outputPath/$extensionId.crx"
mkdir -p "$outputPath"
unzipFolderPath="${downloadFilePath%.*}"

wget \
  --quiet \
  --referer="https://chrome.google.com/webstore/detail/${extensionId}?hl=en" \
  --user-agent="Mozilla/5.0 Chrome/$CHROME_VERSION" \
  -O "$downloadFilePath" "$crxDownloadUrl"

if [ ! -s "$downloadFilePath" ]; then
  echo "Error: Downloaded file has 0 bytes."
  exit 1
fi

unzipExitCode=0

if [ "$platformOs" = "Linux" ]; then
  7z x -aoa -o"$unzipFolderPath" "$downloadFilePath" || true
else
  unzip -o "$downloadFilePath" -d "$unzipFolderPath" || true
fi
unzipExitCode=$?

if [ $unzipExitCode -eq 1 ]; then
  echo "Warning during unzip, but continuing"
fi

# if output folder does not exist
if [ ! -d "$unzipFolderPath" ]; then
  echo "Error: Unzipped folder does not exist. Check the output of the unzip command."
  exit 1
fi

echo "Extension downloaded to $downloadFilePath"
echo "Extension extracted to $unzipFolderPath"