openwrtv4/scripts/download.pl
Baptiste Jonglez b30ba14e2a scripts/download.pl: fail loudly if provided hash is unsupported
Currently, if the provided hash is unsupported (length different from 32
or 64 bytes), we happily download the requested file without any kind of
checksum verification.

This is quite dangerous and may provide a false sense of security, because
a single typo in the hash (e.g. one character deleted by mistake) may skip
checksum verification entirely.

Instead, fail immediately if we don't support the provided hash.
In particular, if an external package repository decides to change the
hash algorithm one day, we will now fail loudly instead of skipping
checksum verification without complaints.

Note: if some users of scripts/download.pl knowingly provide an empty hash
because they don't need checksum verification, this change will break
them.  This does not seem to be the case currently, but if this feature is
ever needed, an option should be added to download.pl instead of relying
on the hash being empty.

Fixes: eaa4eba10a ("scripts/download.pl: add SHA-256 support")

Signed-off-by: Baptiste Jonglez <git@bitsofnetworks.org>
2017-09-11 17:13:02 +02:00

273 lines
8 KiB
Perl
Executable file

#!/usr/bin/env perl
#
# Copyright (C) 2006 OpenWrt.org
# Copyright (C) 2016 LEDE project
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#
use strict;
use warnings;
use File::Basename;
use File::Copy;
use Text::ParseWords;
@ARGV > 2 or die "Syntax: $0 <target dir> <filename> <hash> <url filename> [<mirror> ...]\n";
my $url_filename;
my $target = glob(shift @ARGV);
my $filename = shift @ARGV;
my $file_hash = shift @ARGV;
$url_filename = shift @ARGV unless $ARGV[0] =~ /:\/\//;
my $scriptdir = dirname($0);
my @mirrors;
my $ok;
$url_filename or $url_filename = $filename;
sub localmirrors {
my @mlist;
open LM, "$scriptdir/localmirrors" and do {
while (<LM>) {
chomp $_;
push @mlist, $_ if $_;
}
close LM;
};
open CONFIG, "<".$ENV{'TOPDIR'}."/.config" and do {
while (<CONFIG>) {
/^CONFIG_LOCALMIRROR="(.+)"/ and do {
chomp;
my @local_mirrors = split(/;/, $1);
push @mlist, @local_mirrors;
};
}
close CONFIG;
};
my $mirror = $ENV{'DOWNLOAD_MIRROR'};
$mirror and push @mlist, split(/;/, $mirror);
return @mlist;
}
sub which($) {
my $prog = shift;
my $res = `which $prog`;
$res or return undef;
$res =~ /^no / and return undef;
$res =~ /not found/ and return undef;
return $res;
}
sub hash_cmd() {
my $len = length($file_hash);
my $cmd;
$len == 64 and return "mkhash sha256";
$len == 32 and return "mkhash md5";
return undef;
}
sub download_cmd($) {
my $url = shift;
my $have_curl = 0;
if (open CURL, '-|', 'curl', '--version') {
if (defined(my $line = readline CURL)) {
$have_curl = 1 if $line =~ /^curl /;
}
close CURL;
}
return $have_curl
? (qw(curl -f --connect-timeout 20 --retry 5 --location --insecure), shellwords($ENV{CURL_OPTIONS} || ''), $url)
: (qw(wget --tries=5 --timeout=20 --no-check-certificate --output-document=-), shellwords($ENV{WGET_OPTIONS} || ''), $url)
;
}
my $hash_cmd = hash_cmd();
$hash_cmd or die "Cannot find appropriate hash command, ensure the provided hash is either a MD5 or SHA256 checksum.\n";
sub download
{
my $mirror = shift;
$mirror =~ s!/$!!;
if ($mirror =~ s!^file://!!) {
if (! -d "$mirror") {
print STDERR "Wrong local cache directory -$mirror-.\n";
cleanup();
return;
}
if (! -d "$target") {
system("mkdir", "-p", "$target/");
}
if (! open TMPDLS, "find $mirror -follow -name $filename 2>/dev/null |") {
print("Failed to search for $filename in $mirror\n");
return;
}
my $link;
while (defined(my $line = readline TMPDLS)) {
chomp ($link = $line);
if ($. > 1) {
print("$. or more instances of $filename in $mirror found . Only one instance allowed.\n");
return;
}
}
close TMPDLS;
if (! $link) {
print("No instances of $filename found in $mirror.\n");
return;
}
print("Copying $filename from $link\n");
copy($link, "$target/$filename.dl");
$hash_cmd and do {
if (system("cat '$target/$filename.dl' | $hash_cmd > '$target/$filename.hash'")) {
print("Failed to generate hash for $filename\n");
return;
}
};
} else {
my @cmd = download_cmd("$mirror/$url_filename");
print STDERR "+ ".join(" ",@cmd)."\n";
open(FETCH_FD, '-|', @cmd) or die "Cannot launch curl or wget.\n";
$hash_cmd and do {
open MD5SUM, "| $hash_cmd > '$target/$filename.hash'" or die "Cannot launch $hash_cmd.\n";
};
open OUTPUT, "> $target/$filename.dl" or die "Cannot create file $target/$filename.dl: $!\n";
my $buffer;
while (read FETCH_FD, $buffer, 1048576) {
$hash_cmd and print MD5SUM $buffer;
print OUTPUT $buffer;
}
$hash_cmd and close MD5SUM;
close FETCH_FD;
close OUTPUT;
if ($? >> 8) {
print STDERR "Download failed.\n";
cleanup();
return;
}
}
$hash_cmd and do {
my $sum = `cat "$target/$filename.hash"`;
$sum =~ /^(\w+)\s*/ or die "Could not generate file hash\n";
$sum = $1;
if ($sum ne $file_hash) {
print STDERR "Hash of the downloaded file does not match (file: $sum, requested: $file_hash) - deleting download.\n";
cleanup();
return;
}
};
unlink "$target/$filename";
system("mv", "$target/$filename.dl", "$target/$filename");
cleanup();
}
sub cleanup
{
unlink "$target/$filename.dl";
unlink "$target/$filename.hash";
}
@mirrors = localmirrors();
foreach my $mirror (@ARGV) {
if ($mirror =~ /^\@SF\/(.+)$/) {
# give sourceforge a few more tries, because it redirects to different mirrors
for (1 .. 5) {
push @mirrors, "http://downloads.sourceforge.net/$1";
}
} elsif ($mirror =~ /^\@APACHE\/(.+)$/) {
push @mirrors, "https://mirror.netcologne.de/apache.org/$1";
push @mirrors, "https://mirror.aarnet.edu.au/pub/apache/$1";
push @mirrors, "https://mirror.csclub.uwaterloo.ca/apache/$1";
push @mirrors, "http://mirror.cogentco.com/pub/apache/$1";
push @mirrors, "http://mirror.navercorp.com/apache/$1";
push @mirrors, "http://ftp.jaist.ac.jp/pub/apache/$1";
push @mirrors, "ftp://apache.cs.utah.edu/apache.org/$1";
push @mirrors, "ftp://apache.mirrors.ovh.net/ftp.apache.org/dist/$1";
} elsif ($mirror =~ /^\@GITHUB\/(.+)$/) {
# give github a few more tries (different mirrors)
for (1 .. 5) {
push @mirrors, "https://raw.githubusercontent.com/$1";
}
} elsif ($mirror =~ /^\@GNU\/(.+)$/) {
push @mirrors, "https://mirror.csclub.uwaterloo.ca/gnu/$1";
push @mirrors, "https://mirror.netcologne.de/gnu/$1";
push @mirrors, "http://ftp.kddilabs.jp/GNU/gnu/$1";
push @mirrors, "http://www.nic.funet.fi/pub/gnu/gnu/$1";
push @mirrors, "http://mirror.internode.on.net/pub/gnu/$1";
push @mirrors, "http://mirror.navercorp.com/gnu/$1";
push @mirrors, "ftp://mirrors.rit.edu/gnu/$1";
push @mirrors, "ftp://download.xs4all.nl/pub/gnu/";
} elsif ($mirror =~ /^\@SAVANNAH\/(.+)$/) {
push @mirrors, "https://mirror.netcologne.de/savannah/$1";
push @mirrors, "https://mirror.csclub.uwaterloo.ca/nongnu/$1";
push @mirrors, "http://ftp.acc.umu.se/mirror/gnu.org/savannah/$1";
push @mirrors, "http://nongnu.uib.no/$1";
push @mirrors, "http://ftp.igh.cnrs.fr/pub/nongnu/$1";
push @mirrors, "http://public.p-knowledge.co.jp/Savannah-nongnu-mirror/$1";
push @mirrors, "ftp://cdimage.debian.org/mirror/gnu.org/savannah/$1";
push @mirrors, "ftp://ftp.acc.umu.se/mirror/gnu.org/savannah/$1";
} elsif ($mirror =~ /^\@KERNEL\/(.+)$/) {
my @extra = ( $1 );
if ($filename =~ /linux-\d+\.\d+(?:\.\d+)?-rc/) {
push @extra, "$extra[0]/testing";
} elsif ($filename =~ /linux-(\d+\.\d+(?:\.\d+)?)/) {
push @extra, "$extra[0]/longterm/v$1";
}
foreach my $dir (@extra) {
push @mirrors, "https://cdn.kernel.org/pub/$dir";
push @mirrors, "https://mirror.rackspace.com/kernel.org/$dir";
push @mirrors, "http://download.xs4all.nl/ftp.kernel.org/pub/$dir";
push @mirrors, "http://mirrors.mit.edu/kernel/$dir";
push @mirrors, "http://ftp.nara.wide.ad.jp/pub/kernel.org/$dir";
push @mirrors, "http://www.ring.gr.jp/archives/linux/kernel.org/$dir";
push @mirrors, "ftp://ftp.riken.jp/Linux/kernel.org/$dir";
push @mirrors, "ftp://www.mirrorservice.org/sites/ftp.kernel.org/pub/$dir";
}
} elsif ($mirror =~ /^\@GNOME\/(.+)$/) {
push @mirrors, "https://mirror.csclub.uwaterloo.ca/gnome/sources/$1";
push @mirrors, "http://ftp.acc.umu.se/pub/GNOME/sources/$1";
push @mirrors, "http://ftp.kaist.ac.kr/gnome/sources/$1";
push @mirrors, "http://www.mirrorservice.org/sites/ftp.gnome.org/pub/GNOME/sources/$1";
push @mirrors, "http://mirror.internode.on.net/pub/gnome/sources/$1";
push @mirrors, "http://ftp.belnet.be/ftp.gnome.org/sources/$1";
push @mirrors, "ftp://ftp.cse.buffalo.edu/pub/Gnome/sources/$1";
push @mirrors, "ftp://ftp.nara.wide.ad.jp/pub/X11/GNOME/sources/$1";
}
else {
push @mirrors, $mirror;
}
}
#push @mirrors, 'http://mirror1.openwrt.org';
push @mirrors, 'http://sources.lede-project.org';
push @mirrors, 'http://mirror2.openwrt.org/sources';
push @mirrors, 'http://downloads.openwrt.org/sources';
while (!-f "$target/$filename") {
my $mirror = shift @mirrors;
$mirror or die "No more mirrors to try - giving up.\n";
download($mirror);
}
$SIG{INT} = \&cleanup;