From f19b4abfb2c238a98f749812c9ba294dd98d8bd0 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Tue, 17 Feb 2015 13:16:58 +0100 Subject: Include NAR size in fingerprint computation This is not strictly needed for integrity (since we already include the NAR hash in the fingerprint) but it helps against endless data attacks [1]. (However, this will also require download-from-binary-cache.pl to bail out if it receives more than the specified number of bytes.) [1] https://isis.poly.edu/~jcappos/papers/cappos_mirror_ccs_08.pdf --- perl/lib/Nix/Manifest.pm | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'perl') diff --git a/perl/lib/Nix/Manifest.pm b/perl/lib/Nix/Manifest.pm index b82c82fb253c..93c9c261ddc9 100644 --- a/perl/lib/Nix/Manifest.pm +++ b/perl/lib/Nix/Manifest.pm @@ -377,7 +377,6 @@ EOF } - # Delete all old manifests downloaded from a given URL. sub deleteOldManifests { my ($url, $curUrlFile) = @_; @@ -399,14 +398,14 @@ sub deleteOldManifests { # signatures. It contains the store path, the SHA-256 hash of the # contents of the path, and the references. sub fingerprintPath { - my ($storePath, $narHash, $references) = @_; + my ($storePath, $narHash, $narSize, $references) = @_; die if substr($storePath, 0, length($Nix::Config::storeDir)) ne $Nix::Config::storeDir; die if substr($narHash, 0, 7) ne "sha256:"; die if length($narHash) != 59; foreach my $ref (@{$references}) { die if substr($ref, 0, length($Nix::Config::storeDir)) ne $Nix::Config::storeDir; } - return "1;" . $storePath . ";" . $narHash . ";" . join(",", @{$references}); + return "1;" . $storePath . ";" . $narHash . ";" . $narSize . ";" . join(",", @{$references}); } @@ -464,7 +463,7 @@ sub parseNARInfo { } my $fingerprint = fingerprintPath( - $storePath, $narHash, + $storePath, $narHash, $narSize, [ map { "$Nix::Config::storeDir/$_" } @refs ]); if (!checkSignature($publicKey, decode_base64($sig64), $fingerprint)) { -- cgit 1.4.1