On Sat, Sep 06, 2014 at 01:30:54AM +0800, lolilolicon wrote:
> Something like `source=('$pkgname-$pkgver.tar.gz')` in the PKGBUILD
> would "just work" with this eval. This could be a security issue since
> URLs are arbitrary external data.
Sounds somewhat contrived. External data, yes, but then you might
consider that the *entire* PKGBUILD is external data which is fed to
makepkg. What makes this particular case special? Is there an immediate
problem that this fixes?
> Instead, expand the dlagent command line into an array, replace the %o,
> %u place holders, and run the resultant command line as is.
>
> A shortcoming of this is the dlagent command line cannot have embedded
> spaces. If this turns out to be a problem, we can do an early eval
> before substituting %o and %u.
> ---
> scripts/makepkg.sh.in | 30 ++++++++++++++----------------
> 1 file changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/scripts/makepkg.sh.in b/scripts/makepkg.sh.in
> index 8e8a64c..a134453 100644
> --- a/scripts/makepkg.sh.in
> +++ b/scripts/makepkg.sh.in
> @@ -288,12 +288,12 @@ get_protocol() {
> get_downloadclient() {
> local proto=$1
>
> - # loop through DOWNLOAD_AGENTS variable looking for protocol
> + # loop through DLAGENTS variable looking for protocol
> local i
> for i in "${DLAGENTS[@]}"; do
> local handler="${i%%::*}"
> if [[ $proto = "$handler" ]]; then
> - local agent="${i##*::}"
> + local agent="${i#*::}"
While I agree with this change (and other similar fixups), it seems
unrelated to the rest of the commit...
> break
> fi
> done
> @@ -308,8 +308,7 @@ get_downloadclient() {
> # ensure specified program is installed
> local program="${agent%% *}"
> if [[ ! -x $program ]]; then
> - local baseprog="${program##*/}"
> - error "$(gettext "The download program %s is not installed.")"
> "$baseprog"
> + error "$(gettext "The download program '%s' is not
> installed.")" "$program"
> plain "$(gettext "Aborting...")"
> exit 1 # $E_MISSING_PROGRAM
> fi
> @@ -342,15 +341,16 @@ download_file() {
> local proto=$(get_protocol "$netfile")
>
> # find the client we should use for this URL
> - local dlcmd
> - dlcmd=$(get_downloadclient "$proto") || exit $?
> + local -a cmdline
> + local IFS=' '
How sure are you that this won't affect some later operation in the
function?
> + cmdline=($(get_downloadclient "$proto")) || exit
Why not use read to split the result?
IFS=' ' read -a cmdline < <(get_downloadclient "$proto")
[[ $cmdline ]] || exit
> local filename=$(get_filename "$netfile")
> local url=$(get_url "$netfile")
>
> if [[ $proto = "scp" ]]; then
> # scp downloads should not pass the protocol in the url
> - url="${url##*://}"
> + url="${url#*://}"
> fi
>
> msg2 "$(gettext "Downloading %s...")" "$filename"
> @@ -359,20 +359,18 @@ download_file() {
> local dlfile="${url##*/}"
>
> # replace %o by the temporary dlfile if it exists
> - if [[ $dlcmd = *%o* ]]; then
> - dlcmd=${dlcmd//\%o/\"$filename.part\"}
> - dlfile="$filename.part"
> + if [[ ${cmdline[*]} = *%o* ]]; then
> + dlfile=$filename.part
> + cmdline=("${cmdline[@]//%o/"$dlfile"}")
> fi
> # add the URL, either in place of %u or at the end
> - if [[ $dlcmd = *%u* ]]; then
> - dlcmd=${dlcmd//\%u/\"$url\"}
> + if [[ ${cmdline[*]} = *%u* ]]; then
> + cmdline=("${cmdline[@]//%u/"$url"}")
> else
> - dlcmd="$dlcmd \"$url\""
> + cmdline+=("$url")
> fi
>
> - local ret=0
> - eval "$dlcmd >&2 || ret=\$?"
> - if (( ret )); then
> + if ! command -- "${cmdline[@]}" >&2; then
> [[ ! -s $dlfile ]] && rm -f -- "$dlfile"
> error "$(gettext "Failure while downloading %s")" "$filename"
> plain "$(gettext "Aborting...")"
> --
> 2.1.0
>
