[openwrt/openwrt] download: handle possibly invalid local tarballs

[LEDE Commits]

ynezz pushed a commit to openwrt/openwrt.git, branch openwrt-19.07:
https://git.openwrt.org/605adb1023efda0c29d160839fccc20801b717cd

commit 605adb1023efda0c29d160839fccc20801b717cd
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Thu Nov 19 16:32:46 2020 +0100

    download: handle possibly invalid local tarballs
    
    Currently it's assumed, that already downloaded tarballs are always
    fine, so no checksum checking is performed and the tarball is used even
    if it might be corrupted.
    
    From now on, we're going to always check the downloaded tarballs before
    considering them valid.
    
    Steps to reproduce:
    
     1. Remove cached tarball
    
       rm dl/libubox-2020-08-06-9e52171d.tar.xz
    
     2. Download valid tarball again
    
       make package/libubox/download
    
     3. Invalidate the tarball
    
       sed -i 's/PKG_MIRROR_HASH:=../PKG_MIRROR_HASH:=ff/' package/libs/libubox/Makefile
    
     4. Now compile with corrupt tarball source
    
       make package/libubox/{clean,compile}
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
    (cherry picked from commit 4e19cbc553350b8146985367ba46514cf50e3393)
---
 include/host-build.mk |  2 ++
 include/package.mk    |  2 ++
 scripts/download.pl   | 18 ++++++++++++++++++
 3 files changed, 22 insertions(+)

diff --git a/include/host-build.mk b/include/host-build.mk
index 827ea6bbfb..79a9b1f8d6 100644
--- a/include/host-build.mk
+++ b/include/host-build.mk
@@ -184,6 +184,8 @@ ifndef DUMP
     clean-build: host-clean-build
   endif
 
+  $(DL_DIR)/$(FILE): FORCE
+
   $(_host_target)host-prepare: $(HOST_STAMP_PREPARED)
   $(_host_target)host-configure: $(HOST_STAMP_CONFIGURED)
   $(_host_target)host-compile: $(HOST_STAMP_BUILT) $(HOST_STAMP_INSTALLED)
diff --git a/include/package.mk b/include/package.mk
index c541f6edf7..f6aa5ea8d0 100644
--- a/include/package.mk
+++ b/include/package.mk
@@ -185,6 +185,8 @@ define Build/CoreTargets
   $(call Build/Autoclean)
   $(call DefaultTargets)
 
+  $(DL_DIR)/$(FILE): FORCE
+
   download:
 	$(foreach hook,$(Hooks/Download),
 		$(call $(hook))$(sep)
diff --git a/scripts/download.pl b/scripts/download.pl
index 5739c20cea..c1623bf91f 100755
--- a/scripts/download.pl
+++ b/scripts/download.pl
@@ -263,6 +263,24 @@ foreach my $mirror (@ARGV) {
 push @mirrors, 'https://sources.openwrt.org';
 push @mirrors, 'https://mirror2.openwrt.org/sources';
 
+if (-f "$target/$filename") {
+	$hash_cmd and do {
+		if (system("cat '$target/$filename' | $hash_cmd > '$target/$filename.hash'")) {
+			die "Failed to generate hash for $filename\n";
+		}
+
+		my $sum = `cat "$target/$filename.hash"`;
+		$sum =~ /^(\w+)\s*/ or die "Could not generate file hash\n";
+		$sum = $1;
+
+		exit 0 if $sum eq $file_hash;
+
+		die "Hash of the local file $filename does not match (file: $sum, requested: $file_hash) - deleting download.\n";
+		unlink "$target/$filename";
+		cleanup();
+	};
+}
+
 while (!-f "$target/$filename") {
 	my $mirror = shift @mirrors;
 	$mirror or die "No more mirrors to try - giving up.\n";