ADDED common/helpers/download Index: common/helpers/download ================================================================== --- /dev/null +++ common/helpers/download @@ -0,0 +1,120 @@ +#! /usr/bin/env bash + +url="$1" +file="$2" +hash="$3" + +if [ "${#}" != '3' ]; then + echo 'Usage: download ' >&2 + + exit 1 +fi + +for tryDownloadProgram in wget curl; do + tryDownloadProgramPath="$(which "${tryDownloadProgram}" 2>/dev/null)" + + if [ -z "${tryDownloadProgramPath}" ]; then + continue + fi + + if [ -x "${tryDownloadProgramPath}" ]; then + downloadProgram="${tryDownloadProgram}" + downloadProgramPath="${tryDownloadProgramPath}" + + break + fi +done + +case "${hash}" in + ????????????????????????????????????????) + hashMethod='sha1' + ;; + ????????????????????????????????????????????????????????????????) + hashMethod='sha256' + ;; + -) + hashMethod='null' + ;; + *) + echo "Unknown hash method for hash ${hash}" >&2 + + exit 1 + ;; +esac + +function downloadFile() { + local file urls + local downloadProgramArgs + local url + local finalURL + + file="$1" + shift + + urls=("$@") + + finalURL="${urls[-1]}" + + case "${downloadProgram}" in + curl) + downloadProgramArgs=(--header "X-Cache-URL: ${finalURL}" --location --insecure --fail --output "${file}") + ;; + wget) + downloadProgramArgs=(--header="X-Cache-URL: ${finalURL}" --no-check-certificate --output-document="${file}") + ;; + esac + + for url in "${urls[@]}" __fail__; do + rm -f "${file}" + + if [ "${url}" = '__fail__' ]; then + return 1 + fi + + "${downloadProgram}" "${downloadProgramArgs[@]}" "${url}" && break + done + + return 0 +} + +function verifyHash() { + local file hash hashMethod + local checkHash + + file="$1" + hash="$2" + hashMethod="$3" + + if [ "${hashMethod}" = 'null' ]; then + return 0 + fi + + checkHash="$(openssl "${hashMethod}" "${file}" | sed 's@.*= *@@')" + + if [ "${checkHash}" = "${hash}" ]; then + return 0 + fi + + echo "Hash (${hashMethod}) mismatch: Got: ${checkHash}; Expected: ${hash}" >&2 + + return 1 +} + +rm -f "${file}.new" || exit 1 + +urls=("${url}") + +if [ "${hashMethod}" != 'null' ]; then + urls=( + "http://hashcache.rkeene.org/${hashMethod}/${hash}" + "${urls[@]}" + ) +fi + +downloadFile "${file}.new" "${urls[@]}" || exit 1 + +verifyHash "${file}.new" "${hash}" "${hashMethod}" || exit 1 + +mv "${file}.new" "${file}" || exit 1 + +exit 0