4aae026615
$ARCH-repodata is currently not protected by a signature. While most of the package metadata is also embedded into the .xbps files, which are protected by a signature, xbps-install ignores it (https://github.com/voidlinux/xbps/blob/1670ff000d1cc8b073dd93542e16b9c1c496bb9a/lib/package_unpack.c#L123) and relies entirely on $ARCH-repodata. This enables anyone who is able to modify the $ARCH-repodata to substitute packages. This patch adds a check that verifies the signed pkgver matches the one in the repodata, so at least downgrades posing as updates are detected. This is an incomplete fix as the whole transaction is still set up with the unsigned repodata and other issues surely exist. The real fix is signing $ARCH-repodata.