From 91275ac998c439420da747fc047379a6547f7c1c Mon Sep 17 00:00:00 2001 From: Silvio Rhatto Date: Sat, 24 Feb 2024 14:20:19 -0300 Subject: Feat: convert docs from Ikiwiki to MkDocs --- docs/checking.md | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 docs/checking.md (limited to 'docs/checking.md') diff --git a/docs/checking.md b/docs/checking.md new file mode 100644 index 0000000..ee3f32c --- /dev/null +++ b/docs/checking.md @@ -0,0 +1,124 @@ +# Integrity checking + +## Debian Images + +See [Verifying authenticity of Debian CDs](https://www.debian.org/CD/verify). + +## Source packages + +This is the trick part. In theory, you could run just + + dscverify *.dsc + +Which would check if the signature was made for a key included in the `debian-keyring` package or if you +have a verification path with the signing key. + +In practice, it should always work for sources you download from the **same** Debian version you're running. +But sources you download from newer versions might not work, depending basically if the maintainer's key is +already on the `debian-keyring` you installed. + +### Using a newer debian-keyring package + +You might want to try a newer `debian-keyring` package (for testing or unstable), which we haven't tested +yet but can reduce a lot of complexity that follows. + +### Install manually debian-keyring somewhere + +If not, you might try to have a newer copy of the `debian-keyring` somewhere. We already provide one in the +a way for you to get the keyring directly from https://keyring.debian.org: + + make keyring + +We use `--no-default-keyring` to make sure `gpg` just looks for the key in the `debian-maintainers` keyring: + + gpg --no-default-keyring --keyring /path/to/debian/keyring/keyrings/debian-keyring.gpg --verify *.dsc + +You might also want to have the following on your `~/.devscripts` (line break just to keep formatting here): + + DSCVERIFY_KEYRINGS="/usr/share/keyrings/debian-keyring.gpg:/usr/share/keyrings/debian-maintainers.gpg: + /path/to/debian/keyring/keyrings/debian-keyring.gpg:/path/to/debian/keyring/keyrings/debian-maintainers.gpg" + +Or you can use the following alias: + + alias dscverify='dscverify --keyring /path/to/debian/keyring/keyrings/debian-keyring.gpg --keyring /path/to/debian/keyring/keyrings/debian-maintainers.gpg' + +### Manually getting the key + +Another option is to get the specific key: + + gpg --recv-keys 12345678 + +Either way, you have to have a criteria about how much trust you should give to the keyring or the pubkey +you just downloaded. The same goes for software you're porting to Debian and that you can't actually check +it's signature against `debian-keyring`. + +### Issues with dpkg-source + +Things get even trickier when you try to use `dpkg-source`. See [Debian Bug report logs - #852019 gpgv: unknown +type of key resource 'trustedkeys.kbx'](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=852019) +for details. + +Even if you merge both `keyring/keyrings/debian-keyring.gpg` `keyring/keyrings/debian-maintainers.gpg` +into some file like `keyring/keyrings/pubring.kbx`, symlink it as `keyring/keyrings/trustedkeys.gpg` +and point `GNUPGHOME` to this folder you'll still get a weird behavior: + + 0 $ dget http://ftp.de.debian.org/debian/pool/main/r/ruby-childprocess/ruby-childprocess_0.5.2-1.dsc + dget: retrieving http://ftp.de.debian.org/debian/pool/main/r/ruby-childprocess/ruby-childprocess_0.5.2-1.dsc + % Total % Received % Xferd Average Speed Time Time Time Current + Dload Upload Total Spent Left Speed + 100 1827 100 1827 0 0 2626 0 --:--:-- --:--:-- --:--:-- 4911 + dget: retrieving http://ftp.de.debian.org/debian/pool/main/r/ruby-childprocess/ruby-childprocess_0.5.2.orig.tar.gz + % Total % Received % Xferd Average Speed Time Time Time Current + Dload Upload Total Spent Left Speed + 100 26055 100 26055 0 0 20738 0 0:00:01 0:00:01 --:--:-- 27455 + dget: retrieving http://ftp.de.debian.org/debian/pool/main/r/ruby-childprocess/ruby-childprocess_0.5.2-1.debian.tar.xz + % Total % Received % Xferd Average Speed Time Time Time Current + Dload Upload Total Spent Left Speed + 100 2892 100 2892 0 0 4183 0 --:--:-- --:--:-- --:--:-- 8078 + ruby-childprocess_0.5.2-1.dsc: + Good signature found + validating ruby-childprocess_0.5.2.orig.tar.gz + validating ruby-childprocess_0.5.2-1.debian.tar.xz + All files validated successfully. + gpgv: Signature made Seg 28 Abr 2014 18:03:27 BRT using RSA key ID 39CD217A + gpgv: Impossível verificar assinatura: chave pública não encontrada + dpkg-source: warning: failed to verify signature on ./ruby-childprocess_0.5.2-1.dsc + dpkg-source: info: extracting ruby-childprocess in ruby-childprocess-0.5.2 + dpkg-source: info: unpacking ruby-childprocess_0.5.2.orig.tar.gz + dpkg-source: info: unpacking ruby-childprocess_0.5.2-1.debian.tar.xz + 0 $ + +What happened here is that `dscverify` honoured our custom configuration above while `dpkg-source` is still relying on +the one available in the `debian-keyring` package. + +Even if you remove the `debian-keyring` package, it will still fallback to your `$HOME/.gnupg/trustedkeys.gpg` which +you don't really want to fill with keys you actually haven't stablished a proper trust relationship. + +As currently `dpkg-source` doesn't honour `GNUPGHOME` (see TODO for bugreport), all we can do currently is call `dget` +and `dpkg-source` with + + HOME=/path/to/debian/keyring/ dpkg-source -x $package*dsc + HOME=/path/to/debian/keyring/ dget + +For this trick to work, you'll need to run + + make keyring + +Again, you might set two handy aliases for your shell: + + alias dpkg-source='HOME=/path/to/debian/keyring/keyrings/ dpkg-source' + alias dget='HOME=/path/to/debian/keyring/keyrings/ dget' + +Optionally, as a last touch, import your own key into this keyring: + + gpg --armor --export $KEYID | \ + gpg --no-default-keyring --keyring /path/to/debian/keyring/keyrings/.gnupg/trustedkeys.gpg --import + +Then you might be happy... for a while :P + +See also: + +* `dscverify(1)` manpage. +* [Debian Public Key Server](http://keyring.debian.org/) and it's [workflow](https://keyring.debian.org/keyring-workflow.html). +* [apt get - How to get apt-get source verification working? - Super User](https://superuser.com/questions/626810/how-to-get-apt-get-source-verification-working). +* [Debian. How can I securely get debian-archive-keyring, so that I can do an apt-get update? NO_PUBKEY - Server Fault](http://serverfault.com/questions/337278/debian-how-can-i-securely-get-debian-archive-keyring-so-that-i-can-do-an-apt-g/337283#337283). -- cgit v1.2.3