Search Results: "hecker"

15 July 2017

Vasudev Kamath: debcargo: Replacing subprocess crate with git2 crate

In my previous post I talked about using subprocess crate to extract beginning and ending year from git repository for generating debian/copyright file. In this post I'm going to talk on how I replaced subprocess with native git2 crate and achieved the same result in much cleaner and safer way. git2 is a native Rust crate which provides access to Git repository internals. git2 does not involve any unsafe invocation as it is built against libgit2-sys which is actually using Rust FFI to directly bind to underlying libgit library. Below is the new copyright_fromgit function with git2 crate. 
fn copyright_fromgit(repo_url: &str) -> Result<String>  
   let tempdir = TempDir::new_in(".", "debcargo")?;
   let repo = Repository::clone(repo_url, tempdir.path())?;
   let mut revwalker = repo.revwalk()?;
   revwalker.push_head()?;
   // Get the latest and first commit id. This is bit ugly
   let latest_id = revwalker.next().unwrap()?;
   let first_id = revwalker.last().unwrap()?; // revwalker ends here is consumed by last
   let first_commit = repo.find_commit(first_id)?;
   let latest_commit = repo.find_commit(latest_id)?;
   let first_year =
       DateTime::<Utc>::from_utc(
               NaiveDateTime::from_timestamp(first_commit.time().seconds(), 0),
               Utc).year();
   let latest_year =
       DateTime::<Utc>::from_utc(
             NaiveDateTime::from_timestamp(latest_commit.time().seconds(), 0),
             Utc).year();
   let notice = match first_year.cmp(&latest_year)  
       Ordering::Equal => format!(" ", first_year),
       _ => format!(" - ,", first_year, latest_year),
    ;
   Ok(notice)
So here is what I'm doing
  1. Use git2::Repository::clone to clone the given URL. We are thus avoiding exec of git clone command.
  2. Get a revision walker object. git2::RevWalk implements Iterator trait and allows walking through the git history. This is what we are using to avoid exec of git log command.
  3. revwalker.push_head() is important because we want to tell revwalker from where we want to walk the history. In this case we are asking it to walk history from repository HEAD. Without this line next line will not work. (Learned it in hard way :-) ).
  4. Then we extract git2::Oid which is we can say similar to commit hash and can be used to lookup a particular commit. We take latest commit hash using RevWalk::next call and the first commit using Revwalk::last, note the order this is because Revwalk::last consumes the revwalker so doing it in reverse order will make borrow checker unhappy :-). This replaces exec of head -n1 command.
  5. Look up the git2::Commit objects using git2::Repository::find_commit
  6. Then convert the git2::Time to chrono::DateTime and take out the years.
After this change I found an obvious error which went unnoticed in previous version, that is if there was no repository key in Cargo.toml. When there was no repo URL git clone exec did not error out and our shell commands happily extracted year from the debcargo repository!. Well since I was testing code from debcargo repository It never failed, but when I executed from non-git repository folder git threw an error but that was git log and not git clone. This error was spotted right away because git2 threw me an error that I gave it empty URL. When it comes to performance I see that debcargo is faster compared to previous version. This makes sense because previously it was doing 5 fork and exec system calls and now that is avoided.

3 July 2017

Antoine Beaupr : My free software activities, June 2017

Debian Long Term Support (LTS) This is my monthly Debian LTS report. This time I worked on Mercurial, sudo and Puppet.

Mercurial remote code execution I issued DLA-1005-1 to resolve problems with the hg server --stdio command that could be abused by "remote authenticated users to launch the Python debugger, and consequently execute arbitrary code, by using --debugger as a repository name" (CVE-2017-9462). Backporting the patch was already a little tricky because, as is often the case in our line of work, the code had changed significantly in newer version. In particular, the commandline dispatcher had been refactored which made the patch non-trivial to port. On the other hand, mercurial has an extensive test suite which allowed me to make those patches in all confidence. I also backported a part of the test suite to detect certain failures better and to fix the output so that it matches the backported code. The test suite is slow, however, which meant slow progress when working on this package. I also noticed a strange issue with the test suite: all hardlink operations would fail. Somehow it seems that my new sbuild setup doesn't support doing hardlinks. I ended up building a tarball schroot to build those types of packages, as it seems the issue is related to the use of overlayfs in sbuild. The odd part is my tests of overlayfs, following those instructions, show that it does support hardlinks, so there maybe something fishy here that I misunderstand. This, however, allowed me to get a little more familiar with sbuild and the schroots. I also took this opportunity to optimize the builds by installing an apt-cacher-ng proxy to speed up builds, which will also be useful for regular system updates.

Puppet remote code execution I have issued DLA-1012-1 to resolve a remote code execution attack against puppetmaster servers, from authenticated clients. To quote the advisory: "Versions of Puppet prior to 4.10.1 will deserialize data off the wire (from the agent to the server, in this case) with a attacker-specified format. This could be used to force YAML deserialization in an unsafe manner, which would lead to remote code execution." The fix was non-trivial. Normally, this would have involved fixing the YAML parsing, but this was considered problematic because the ruby libraries themselves were vulnerable and it wasn't clear we could fix the problem completely by fixing YAML parsing. The update I proposed took the bold step of switching all clients to PSON and simply deny YAML parsing from the server. This means all clients need to be updated before the server can be updated, but thankfully, updated clients will run against an older server as well. Thanks to LeLutin at Koumbit for helping in testing patches to solve this issue.

Sudo privilege escalation I have issued DLA-1011-1 to resolve an incomplete fix for a privilege escalation issue (CVE-2017-1000368 from CVE-2017-1000367). The backport was not quite trivial as the code had changed quite a lot since wheezy as well. Whereas mercurial's code was more complex, it's nice to see that sudo's code was actually simpler and more straightforward in newer versions, which is reassuring. I uploaded the packages for testing and uploaded them a year later. I also took extra time to share the patch in the Debian bugtracker, so that people working on the issue in stable may benefit from the backported patch, if needed. One issue that came up during that work is that sudo doesn't have a test suite at all, so it is quite difficult to test changes and make sure they do not break anything.

Should we upload on fridays? I brought up a discussion on the mailing list regarding uploads on fridays. With the sudo and puppet uploads pending, it felt really ... daring to upload both packages, on a friday. Years of sysadmin work hardwired me to be careful on fridays; as the saying goes: "don't deploy on a friday if you don't want to work on the weekend!" Feedback was great, but I was surprised to find that most people are not worried worried about those issues. I have tried to counter some of the arguments that were brought up: I wonder if there could be a disconnection here between the package maintainer / programmer work and the sysadmin work that is at the receiving end of that work. Having myself to deal with broken updates in the past, I'm surprised this has never come up in the discussions yet, or that the response is so underwhelming. So far, I'll try to balance the need for prompt security updates and the need for stable infrastructure. One does not, after all, go without the other...

Triage I also did small fry triage: Hopefully some of those will come to fruitition shortly.

Other work My other work this month was a little all over the place.

Stressant Uploaded a new release (0.4.1) of stressant to split up the documentation from the main package, as the main package was taking up too much space according to grml developers. The release also introduces limited anonymity option, by blocking serial numbers display in the smartctl output.

Debiman Also did some small followup on the debiman project to fix the FAQ links.

Local server maintenance I upgraded my main server to Debian stretch. This generally went well, althought the upgrade itself took way more time than I would have liked (4 hours!). This is partly because I have a lot of cruft installed on the server, but also because of what I consider to be issues in the automation of major Debian upgrades. For example, I was prompted for changes in configuration files at seemingly random moments during the upgrade, and got different debconf prompts to answer. This should really be batched together, and unfortunately I had forgotten to use the home-made script I established when i was working at Koumbit which shortens the upgrade a bit. I wish we would improve on our major upgrade mechanism. I documented possible solutions for this in the AutomatedUpgrade wiki page, but I'm not sure I see exactly where to go from here. I had a few regressions after the upgrade:
  • the infrared remote control stopped working: still need to investigate
  • my home-grown full-disk encryption remote unlocking script broke, but upstream has a nice workaround, see Debian bug #866786
  • gdm3 breaks bluetooth support (Debian bug #805414 - to be fair, this is not a regression in stretch, it's just that I switched my workstation from lightdm to gdm3 after learning that the latter can do rootless X11!)

Docker and Subsonic I did my first (and late?) foray into Docker and containers. My rationale was that I wanted to try out Subsonic, an impressive audio server which some friends have shown me. Since Subsonic is proprietary, I didn't want it to contaminate the rest of my server and it seemed like a great occasion to try out containers to keep things tidy. Containers may also allow me to transparently switch to the FLOSS fork LibreSonic once the trial period is over. I have learned a lot and may write more about the details of that experience soon, for now you can look at the contributions I made to the unofficial Subsonic docker image, but also the LibreSonic one. Since Subsonic also promotes album covers as first-class citizens, I used beets to download a lot of album covers, which was really nice. I look forward to using beets more, but first I'll need to implement two plugins.

Wallabako I did a small release of wallabako to fix the build with the latest changes in the underlying wallabago library, which led me to ask upstream to make versionned releases. I also looked into creating a separate documentation site but it looks like mkdocs doesn't like me very much: the table of contents is really ugly...

Small fry That's about it! And that was supposed to be a slow month...

18 June 2017

Vasudev Kamath: Rust - Shell like Process pipelines using subprocess crate

I had to extract copyright information from the git repository of the crate upstream. The need aroused as part of updating debcargo, tool to create Debian package source from the Rust crate. General idea behind taking copyright information from git is to extract starting and latest contribution year for every author/committer. This can be easily achieved using following shell snippet 
for author in $(git log --format="%an"   sort -u); do
   author_email=$(git log --format="%an <%ae>" --author="$author"   head -n1)
   first=$(git \
   log --author="$author" --date=format:%Y --format="%ad" --reverse \
               head -n1)
   latest=$(git log --author="$author" --date=format:%Y --format="%ad" \
               head -n1)
   if [ $first -eq $latest ]; then
       echo "$first, $author_email"
   else
       echo "$first-$latest, $author_email"
   fi
done
Now challenge was to execute these command in Rust and get the required answer. So first step was I looked at std::process, default standard library support for executing shell commands. My idea was to execute first command to extract authors into a Rust vectors or array and then have 2 remaining command to extract years in a loop. (Yes I do not need additional author_email command in Rust as I can easily get both in the first command which is used in for loop of shell snippet and use it inside another loop). So I setup to 3 commands outside the loop with input and output redirected, following is snippet should give you some idea of what I tried to do. 
let authors_command = Command::new("/usr/bin/git")
             .arg("log")
             .arg("--format=\"%an <%ae>\"")
             .spawn()?;
let output = authors_command.wait()?;
let authors: Vec<String> = String::from_utf8(output.stdout).split('\n').collect();
let head_n1 = Command::new("/usr/bin/head")
             .arg("-n1")
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
             .spwn()?;
for author in &authors  
             ...
And inside the loop I would create additional 2 git commands read their output via pipe and feed it to head command. This is where I learned that it is not straight forward as it looks :-). std::process::Command type does not implement Copy nor Clone traits which means one use of it I will give up the ownership!. And here I started fighting with borrow checker. I need to duplicate declarations to make sure I've required commands available all the time. Additionally I needed to handle error output at every point which created too many nested statements there by complicating the program and reducing its readability When all started getting out of control I gave a second thought and wondered if it would be good to write down this in shell script ship it along with debcargo and use the script Rust program. This would satisfy my need but I would need to ship additional script along with debcargo which I was not really happy with. Then a search on crates.io revealed subprocess, a crate designed to be similar with subprocess module from Python!. Though crate is not highly downloaded it still looked promising, especially the trait implements a trait called BitOr which allows use of operator to chain the commands. Additionally it allows executing full shell commands without need of additional chaining of argument which was done above snippet. End result a much simplified easy to read and correct function which does what was needed. Below is the function I wrote to extract copyright information from git repo. 
fn copyright_fromgit(repo: &str) -> Result<Vec<String>>  
    let tempdir = TempDir::new_in(".", "debcargo")?;
    Exec::shell(OsStr::new(format!("git clone --bare    ",
                                repo,
                                tempdir.path().to_str().unwrap())
                              .as_str())).stdout(subprocess::NullFile)
                              .stderr(subprocess::NullFile)
                              .popen()?;
    let author_process =  
         Exec::shell(OsStr::new("git log --format=\"%an <%ae>\"")).cwd(tempdir.path())  
         Exec::shell(OsStr::new("sort -u"))
      .capture()?;
    let authors = author_process.stdout_str().trim().to_string();
    let authors: Vec<&str> = authors.split('\n').collect();
    let mut notices: Vec<String> = Vec::new();
    for author in &authors  
        let reverse_command = format!("git log --author=\" \" --format=%ad --date=format:%Y \
                                    --reverse",
                                   author);
        let command = format!("git log --author=\" \" --format=%ad --date=format:%Y",
                           author);
        let first =  
             Exec::shell(OsStr::new(&reverse_command)).cwd(tempdir.path())  
             Exec::shell(OsStr::new("head -n1"))
          .capture()?;
         let latest =  
             Exec::shell(OsStr::new(&command)).cwd(tempdir.path())   Exec::shell("head -n1")
          .capture()?;
        let start = i32::from_str(first.stdout_str().trim())?;
        let end = i32::from_str(latest.stdout_str().trim())?;
        let cnotice = match start.cmp(&end)  
            Ordering::Equal => format!(" ,  ", start, author),
            _ => format!(" - ,  ", start, end, author),
         ;
        notices.push(cnotice);
     
    Ok(notices)
Of course it is not as short as the shell or probably Python code, but that is fine as Rust is system level programming language (which is intended to replace C/C++) and doing complex Shell code (complex due to need of shell pipelines) in approximately 50 lines of code in safe and secure way is very much acceptable. Besides code is as much readable as a plain shell snippet thanks to the operator implemented by subprocess crate.

1 April 2017

Antoine Beaupr : My free software activities, February and March 2017

Looking into self-financing Before I begin, I should mention that I started tracking my time working on free software more systematically. I spend a lot of time on the computer, as regular readers of this blog might remember so I wanted to know exactly how much time was paid vs free work. I was already using org-mode's time clock system to keep track of my work hours, so I just extended this to my regular free software contributions, which also helps in writing those reports. It turns out that over 60% of my computer time is spent working on free software. That's huge! I was expecting something more along the range of 20 to 40% of my time. So I started thinking about ways of financing this work. I created a Patreon page but I'm hesitant into launching such a campaign: the only thing worse than "no patreon page" is "a patreon page with failed goals and no one financing it". So before starting such an effort, I'd like to get a feeling of what other people's experience with it are. I know that joeyh is close to achieving his goals, but I can't compare with the guy that invented git-annex or debhelper, so I'm concerned I wouldn't be able to raise the same level of funding. So any advice you have, feel free to contact me in private or in the comments. If you would be ready to fund my work, I'd love to know about it, obviously, but I guess I wouldn't get real numbers until I actually open up such a page... Now, onto the regular report.

Wallabako I spent a good chunk of time completing most of the things I had in mind for Wallabako, which I mentioned quickly in the previous report. Wallabako is now much easier to installed, with clearer instructions, an easier to use configuration file, more reliable synchronization and read status propagation. As usual the Wallabako README file has all the details. I've also looked at better integration with Koreader, the free software e-reader that forms the basis of the okreader free software distribution which has been able to port Debian to the Kobo e-readers, a project I am really excited about. This project has the potential of supporting Kobo readers beyond the lifetime that upstream grants it and removes a lot of proprietary software and spyware that ships with the Kobo readers. So I have made a few contributions to okreader and also on koreader, the ebook reader okreader is based on.

Stressant I rewrote stressant, my simple burn-in and stress-testing tool. After struggling in turn with Debirf, live-build, vmdebootstrap and even FAI, I just figured maybe it wasn't the best idea to try and reinvent that particular wheel: instead of reinventing how to build yet another Debian system build tool, maybe I should just reuse what's already there. It turns out there's a well known, succesful and fairly complete recovery system called Grml. It is a Debian Derivative, so all I needed to do was to stop procrastinating and actually write the actual stressant tool instead of just creating a distribution with a bunch of random tools shipped in. This allowed me to focus on which tools were the best to stress test different components. This selection ended up being: fio can also be used to overwrite disk drives with the proper options (--overwrite and --size=100%), although grml also ships with nwipe for wiping old spinning disks and hdparm to do a secure erase of SSD disks (whatever that's worth). Stressant still needs to be shipped with grml for this transition to be complete. In the meantime, I was able to configure the excellent public Gitlab CI service to provide ISO images with Stressant built-in as a stopgap measure. I also need to figure out a way to automate starting stressant from a boot menu to automate deployments on a larger scale, although because I have little need for the feature at this moment in time, this will likely wait for a sponsor to show up for this to be implemented. Still, stressant has useful features like the capability of sending logs by email using a fresh new implementation of the Python SMTPHandler (BufferedSMTPHandler) which waits for logging to complete before sending a single email. Another interesting piece of code in there is the NegateAction argparse handler that enables the use of "toggle flags" (e.g. --flag / --no-flag). I'm so happy with the code that I figure I could just share it here directly: 
class NegateAction(argparse.Action):
    '''add a toggle flag to argparse

    this is similar to 'store_true' or 'store_false', but allows
    arguments prefixed with --no to disable the default. the default
    is set depending on the first argument - if it starts with the
    negative form (define by default as '--no'), the default is False,
    otherwise True.
    '''
    negative = '--no'
    def __init__(self, option_strings, *args, **kwargs):
        '''set default depending on the first argument'''
        default = not option_strings[0].startswith(self.negative)
        super(NegateAction, self).__init__(option_strings, *args,
                                           default=default, nargs=0, **kwargs)
    def __call__(self, parser, ns, values, option):
        '''set the truth value depending on whether
        it starts with the negative form'''
        setattr(ns, self.dest, not option.startswith(self.negative))
Short and sweet. I wonder why stuff like this is not in the standard library yet - maybe just because no one bothered yet? It'd be great to get feedback of more experienced Pythonistas on this one. I hope that my work on Stressant is complete. I get zero funding for this work, and have little use for it myself: I manage only a few machines and such a tool really shines when you regularly put new hardware online, which is (fortunately?) not my case anymore. I'd be happy, of course, to accompany organisations and people that wish to further develop and use such a tool. A short demo of stressant as well as detailed description of how it works is of course available in its README file.

Standard third party repositories After looking at improvements for the grml repository instructions, I realized there was no real "best practices" document on how to configure an Apt repository. Sure, there are tools like reprepro and others, but those hardly qualify as policy: they are very flexible and there are lots of ways to create insecure repositories or curl sh style instructions, which we of course generally want to avoid. While the larger problem of Unstrusted Debian packages remain generally unsolved (e.g. when you install any .deb file, it can get root on your system), it seemed to me one critical part of this problem was how to add a random third-party repository to your machine while limiting, as much as possible, what possible attackers could do with such a repository. In other words, to solve the more general problem of insecure .deb files, we also need to solve the distribution problem, otherwise fixing the .deb files themselves will be useless. This lead to the creation of standardized repository instructions that define:
  1. how to distribute the repository's public signing key (ie. over HTTPS)
  2. how to name suites and components (e.g. use stable and main unless you have a good reason, and explain yourself)
  3. recommend a healthy does of apt preferences pinning
  4. how to distribute keys (e.g. with a derive-archive-keyring package)
I've seen so many third party repositories get this wrong. For example, a lot of repositories recommend this type of command to intialize the OpenPGP trust path: 
curl http://example.com/key.asc   apt-key add -
This has the following problems:
  • the key is transfered in plaintext and can easily be manipulated by an active attacker (e.g. a router on your path to the server or a neighbor in a Wifi cafe)
  • the key is added to the main trust root, which allows the key to authentify as the real Debian archive, therefore giving it all rights over all packages
  • since it's part of the global archive, it's difficult for a package to remove/add the key when a key rollover is necessary (and repositories generally don't provide a deriv-archive-keyring to do that process anyways)
An example of this are the Docker install instructions that, at least, manage to do this over HTTPS. Some other repositories don't even bother teaching people about the proper way of adding those keys. We settled for: 
wget -O /usr/share/keyrings/deriv-archive-keyring.gpg https://deriv.example.net/debian/deriv-archive-keyring.gpg
That location was explicitly chosen to be out of the main trust directory, so that it needs to be explicitly added to the sources.list as well: 
deb [signed-by=/usr/share/keyrings/deriv-archive-keyring.gpg] https://deriv.example.net/debian/ stable main
Similarly, we highly recommend users setup "apt pinning" to restrict what a given repository can do. Since pinning is so confusing, most people don't actually bother even configuring it and I have yet to see a single repo advise its users to configure those preferences, which are essential to limit what a repository can do. To keep configuration simple, we recommend this: 
Package: *
Pin: origin deriv.example.net
Pin-Priority: 100
Obviously, for a single-package repository, the actual package name should be listed, e.g.: 
Package: foo
Pin: origin deriv.example.net
Pin-Priority: 100
And the priority should probably be set to 1 unless you want to allow automatic upgrades. It is my hope that this design will get more traction in the years to come and become a de-facto standard that will be a key part in safely adding third party repositories. There is obviously much more work to be done to improve security when installing untrusted .deb files, and I encourage Debian developers to consider contributing to the UntrustedDebs discussions and particularly to the Teams/Dpkg/Spec/DeclarativePackaging work.

Signal R&D I spent a significant amount of time this month struggling with the Signal project on my phone. I'm still ambivalent on Signal: it's a centralized designed, too dependent on phone numbers, but I must admit they get a lot of things right and it's the only free-software platform that allows for easy-to-use, multi-platform videoconferencing that my family can use. I've been following Signal for a while: up until now, I had been using the LibreSignal rebuild of the official client, as it is distributed on a F-Droid repository. Because I try to avoid Google (proprietary) software on my phone, it's basically the only way I could even install Signal. Unfortunately, the repository is out of date and introduces another point of trust in the distribution model: now you not only need to trust the Signal authors to do the right thing, you also need to trust that F-Droid repo not to inject nasty code on your phone. I've therefore started a discussion about how Signal could be distributed outside of the Google Play Store. I'd like to think it's one of the things that led the Signal people to distribute an official copy of Signal outside of the playstore. After much struggling, I was able to upgrade to this official client and will be able to upgrade easily by just downloading the APK. (Do note that I ended up reinstalling and re-registering Signal, which unfortunately changed my secret keys.) I do hope Signal enters F-Droid one day, but it could take a while because it still doesn't work without Google services and barely works with MicroG, the free software alternative to the Google services clients. Moxie also set a list of requirements like crash reporting and statistics that need to be implemented on F-Droid's side before he agrees to the deployment, so this could take a while. I've also participated in the, ahem, discussion on the JWZ blog regarding a supposed vulnerability in Signal where it would leak previously unknown phone numbers to third parties. I reviewed the way the phone number is uploaded and, while it's possible to create a rainbow table of phone numbers (which are hashed with a truncated SHA-1 checksum), I couldn't verify the claims of other participants in the thread. For me, Signal still does the right thing with contacts, although I do question the way "read status" notifications get transmitted, but that belong in another bug report / blog post.

Debian Long Term Support (LTS) It's been more than a year working on Debian LTS, started by Raphael Hertzog at Freexian. I didn't work much in February so I had a lot of hours to catchup with, and was unfortunately unable to do so, partly because I was busy with other projects, and partly because my colleagues are doing a great job at resolving the most important issues. So one my concerns this month was finding work. It seemed that all the hard packages were either taken (e.g. my usual favorites, tiff and imagemagick, we done by others) or just too challenging (e.g. I don't feel quite comfortable tackling the LTS branch of the Linux kernel yet). I spent quite a bit of time trying to figure out what was wrong with pcre3, only to realise the "32" in the report was not about the architecture, but about the character width. Because of thise, I marked 4 CVEs (CVE-2017-7186, CVE-2017-7244, CVE-2017-7245, CVE-2017-7246) as "not-affected", since the 32-bith character support wasn't enabled in wheezy (or jessie, for that matter). I still spent some time trying to reproduce the issues, which require a compiler with an AddressSanitizer, something that was introduced in both Clang and GCC after Wheezy was released, which makes reproducing this fairly complicated... This allowed me to experiment more with Vagrant, however, and I have provided the Debian cloud team with a 32-bit Vagrant box that was merged in shortly after, although it doesn't show up yet in the official list of Debian images. Then I looked at the apparmor situation (CVE-2017-6507), Debian bug #858768). That was one tricky bug as well, since it's not a security issue in apparmor per se, but more an issue with things that assume a certain behavior from apparmor. I have concluded that Wheezy was not affected because there are no assumptions of proper isolation there - which are provided only starting from LXC 1.0 - and Docker is not in Wheezy. I also couldn't reproduce the issue on Jessie, but, as it turns out, the issue was sysvinit-specific, which is why I couldn't reproduce it under the default systemd configuration shipped with Jessie. I also looked at the various binutils security issues: as I reported on the mailing list, I didn't see anything serious enough in there to warrant a a security release and followed the lead of both the stable and Red Hat security teams by marking this "no-dsa". I similiarly reviewed the mp3splt security issues (specifically CVE-2017-5666) and was fairly puzzled by that issue, which seems to be triggered only the same address sanitization extensions than PCRE, although there was some pretty wild interplay with debugging flags in there. All in all, it seems we can't reproduce that issue in wheezy, but I do not feel confident enough in the results to push that issue aside for now. I finally uploaded the pending graphicsmagick issue (DLA-547-2), a regression update to fix a crash that was introduced in the previous release (DLA-547-1, mistakenly named DLA-574-1). Hopefully that release should clear up some of the confusion and fix the regression. I also released DLA-879-1 for the CVE-2017-6369 in firebird2.5 which was an interesting experiment: I couldn't reproduce the issue in a local VM. After following the Ubuntu setup tutorial, as I wasn't too familiar with the Firebird database until now (hint: the default username and password is sysdba/masterkey), I ended up assuming we were vulnerable and just backporting the patch after seeing the jessie folks push out a release just in case. I also looked at updating the ca-certificates package to deal with the pending WoSign/Startcom removal: I made an explicit list of the CAs that need to be removed after reviewing the Mozilla list. I also sent a patch for an unrelated issue where ca-certificates is writing to /usr/local (!!) in Debian bug #843722. I have also done some "meta" work in starting a discussion about fixing the missing DLA links in the tracker, as you will notice all of the above links lead to nowhere. Thanks to pabs, there are now some links but unfortunately there are about 500 DLAs missing from the website. We also discussed ways to Debian bug #859123, something which is currently a manual process. This is now in the hands of the excellent webmaster team. I have also filed a few missing security bugs (Debian bug #859135, Debian bug #859136), partly because I wanted to help the security team. But it turned out that I felt the script needed some improvements, so I submitted a patch to improve the script so it is easier to run.

Other projects As usual, there's the usual mixed bags of chaos: More stuff on Github...

Paul Wise: FLOSS Activities March 2017

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Review

Administration
  • Debian systems: apply a patch to userdir-ldap, ask a local admin to reset a dead powerpc buildd, remove dead SH4 porterboxen from LDAP, fix perms on www.d.o OC static mirror, report false positives in an an automated abuse report, redirect 1 student to FAQs/support/DebianEdu, redirect 1 event organiser to partners/trademark/merchandise/DPL, redirect 1 guest account seeker to NM, redirect 1 @debian.org desirer to NM, redirect 1 email bounce to a changes@db.d.o user, redirect 2 people to the listmasters, redirect 1 person to Debian Pure Blends, redirect 1 user to a service admin and redirect 2 users to support
  • Debian packages site: deploy my ports/cruft changes
  • Debian wiki: poke at HP page history and advise a contributor, whitelist 13 email address, whitelist 1 domain, check out history of a banned IP, direct 1 hoster to DebConf17 sponsors team, direct 1 user to OpenStack packaging, direct 1 user to InstallingDebianOn and h-node.org, direct 2 users to different ways to help Debian and direct 1 emeritus DD on repository wiki page reorganisation
  • Debian QA: fix an issue with the PTS news, remove some debugging cruft I left behind, fix the usertags on a QA bug and deploy some code fixes
  • Debian mentors: security upgrades and service restarts
  • Openmoko: security upgrades and reboots

Communication

Sponsors The valgrind backport, samba and libthrift-perl bug reports were sponsored by my employer. All other work was done on a volunteer basis.

22 March 2017

Dirk Eddelbuettel: Suggests != Depends

A number of packages on CRAN use Suggests: casually. They list other packages as "not required" in Suggests: -- as opposed to absolutely required via Imports: or the older Depends: -- yet do not test for their use in either examples or, more commonly, unit tests. So e.g. the unit tests are bound to fail because, well, Suggests != Depends. This has been accomodated for many years by all parties involved by treating Suggests as a Depends and installing unconditionally. As I understand it, CRAN appears to flip a switch to automatically install all Suggests from major repositories glossing over what I consider to be a packaging shortcoming. (As an aside, treatment of Additonal_repositories: is indeed optional; Brooke Anderson and I have a fine paper under review on this) I spend a fair amount of time with reverse dependency ("revdep") checks of packages I maintain, and I will no longer accomodate these packages. These revdep checks take long enough as it is, so I will now blacklist these packages that are guaranteed to fail when their "optional" dependencies are not present. Writing R Extensions says in Section 1.1.3
All packages that are needed10 to successfully run R CMD check on the package must be listed in one of Depends or Suggests or Imports . Packages used to run examples or tests conditionally (e.g. via if(require(pkgname))) should be listed in Suggests or Enhances . (This allows checkers to ensure that all the packages needed for a complete check are installed.) In particular, packages providing only data for examples or vignettes should be listed in Suggests rather than Depends in order to make lean installations possible. [...] It used to be common practice to use require calls for packages listed in Suggests in functions which used their functionality, but nowadays it is better to access such functionality via :: calls.
and continues in Section 1.1.3.1
Note that someone wanting to run the examples/tests/vignettes may not have a suggested package available (and it may not even be possible to install it for that platform). The recommendation used to be to make their use conditional via if(require("pkgname"))): this is fine if that conditioning is done in examples/tests/vignettes.
I will now exercise my option to use 'lean installations' as discussed here. If you want your package included in tests I run, please make sure it tests successfully when only its required packages are present.

15 February 2017

Daniel Stender: APT programming snippets for Debian system maintenance

The Python API for the Debian package manager APT is useful for writing practical system maintenance scripts, which are going beyond shell scripting capabilities. There are Python2 and Python3 libraries for that available as packages, as well as a documentation in the package python-apt-doc. If that s also installed, the documentation then could be found in /usr/share/doc/python-apt-doc/html/index.html, and there are also a couple of example scripts shipped into /usr/share/doc/python-apt-doc/examples. The libraries mainly consists of Python bindings for the libapt-inst and libapt-pkg C++ core libraries of the APT package manager, which makes it processing very fast. Debugging symbols are also available as packages (python ,3 -apt-dbg). The module apt_inst provides features like reading from binary packages, while apt_pkg resembles the functions of the package manager. There is also the apt abstraction layer which provides more convenient access to the library, like apt.cache.Cache() could be used to behave like apt-get: 
from apt.cache import Cache
mycache = Cache()
mycache.update()                   # apt-get update
mycache.open()                     # re-open
mycache.upgrade(dist_upgrade=True) # apt-get dist-upgrade
mycache.commit()                   # apply

boil out selections As widely known, there is a feature of dpkg which helps to move a package inventory from one installation to another by just using a text file with a list of installed packages. A selections list containing all installed package could be easily generated with $ dpkg --get-selections > selections.txt. The resulting file then looks something similar like this: 
$ cat selections.txt
0ad                                 install
0ad-data                            install
0ad-data-common                     install
a2ps                                install
abi-compliance-checker              install
abi-dumper                          install
abigail-tools                       install
accountsservice                     install
acl                                 install
acpi                                install
The counterpart for this operation (--set-selections) could be used to reinstall (add) the complete package inventory on another installation resp. computer (that needs superuser rights), like that s explained in the manpage dpkg(1). No problem so far. The problem is, if that list contains a package which couldn t be found in any of the package inventories which are set up in /etc/apt/sources.list(.d/) on the target system, dpkg stops the whole process: 
# dpkg --set-selections < selections.txt
dpkg: warning: package not in database at line 524: google-chrome-beta
dpkg: warning: found unknown packages; this might mean the available database
is outdated, and needs to be updated through a frontend method
Thus, manually downloaded and installed wild packages from unofficial package sources are problematic for this approach, because the package installer simply doesn t know where to get them. Luckily, dpkg puts out the relevant package names, but instead of having them removed manually with an editor this little Python script for python3-apt automatically deletes any of these packages from a selections file: 
#!/usr/bin/env python3
import sys
import apt_pkg
apt_pkg.init()
cache = apt_pkg.Cache()
infile = open(sys.argv[1])
outfile_name = sys.argv[1] + '.boiled'
outfile = open(outfile_name, "w")
for line in infile:
    package = line.split()[0]
    if package in cache:
        outfile.write(line)
infile.close()
outfile.close()
sys.exit(0)
The script takes one argument which is the name of the selections file which has been generated by dpkg. The low level module apt_pkg first has to been initialized with apt_pkg.init(). Then apt_pkg.Cache() can be used to instantiate a cache object (here: cache). That object is iterable, thus it s easy to not perform something if a package from that list couldn t be found in the database, like not copying the corresponding line into the outfile (.boiled), while the others are copied. The result then looks something like this: 
$ diff selections.txt selections.txt.boiled 
3780d3779
< python-timemachine   install
4438d4436
< wlan-supercracker    install
That script might be useful also for moving from one distribution resp. derivative to another (like from Ubuntu to Debian). For productive use, open() should be of course secured against FileNotFound and IOError-s to prevent program crashs on such events.

purge rc-s Like also widely known, deinstalled packages leave stuff like configuration files, maintainer scripts and logs on the computer, to save that if the package gets reinstalled at some point in the future. That happens if dpkg has been used with -r/--remove instead of -P/--purge, which also removes these files which are left otherwise. These packages are then marked as rc in the package archive, like: 
$ dpkg -l   grep ^rc
rc  firebird2.5-common          2.5.6.27020.ds4-3   amd64   common files for firebird 2.5 servers and clients
rc  firebird2.5-server-common   2.5.6.27020.ds4-3   amd64   common files for firebird 2.5 servers
rc  firebird3.0-common          3.0.1.32609.ds4-8   all     common files for firebird 3.0 server, client and utilities
rc  imagemagick-common          8:6.9.6.2+dfsg-2    all     image manipulation programs -- infrastructure dummy package
It could be purged over them afterwards to completely remove them from the system. There are several shell coding snippets to be found on the net for completing this job automatically, like this one here: 
dpkg -l   grep "^rc"   sed  e "s/^rc //"  e "s/ .*$//"   \
xargs dpkg  purge
The first thing which is needed to handle this by a Python script is the information that in apt_pkg, the package state rc per default is represented by the code 5: 
>>> testpackage = cache['firebird2.5-common']
>>> testpackage.current_state
5
For changing things in the database apt_pkg.DepCache() could be docked onto an cache object to manipulate the installation state of a package within, like marking it to be removed resp. purged: 
>>> mydepcache = apt_pkg.DepCache(mycache)
>>> mydepcache.mark_delete(testpackage, True) # True = purge
>>> mydepcache.marked_delete(testpackage)
True
That s basically all which is needed for an old package purging maintenance script in Python 3, another iterator as package filter and there you go: 
#!/usr/bin/env python3
import sys
import apt_pkg
from apt.progress.text import AcquireProgress
from apt.progress.base import InstallProgress
acquire = AcquireProgress()
install = InstallProgress()
apt_pkg.init()
cache = apt_pkg.Cache()
depcache = apt_pkg.DepCache(cache)
for paket in cache.packages:
    if paket.current_state == 5:
        depcache.mark_delete(paket, True)
depcache.commit(acquire, install)
The method DepCache.commit() applies the changes to the package archive at the end, and it needs apt_progress to perform. Of course this script needs superuser rights to run. It then returns something like this: 
$ sudo ./rc-purge 
Reading package lists... Done
Building dependency tree
Reading state information... Done
Fetched 0 B in 0s (0 B/s)
custom fork found
got pid: 17984
got pid: 0
got fd: 4
(Reading database ... 701434 files and directories currently installed.)
Purging configuration files for libmimic0:amd64 (1.0.4-2.3) ...
Purging configuration files for libadns1 (1.5.0~rc1-1) ...
Purging configuration files for libreoffice-sdbc-firebird (1:5.2.2~rc2-2) ...
Purging configuration files for vlc-nox (2.2.4-7) ...
Purging configuration files for librlog5v5 (1.4-4) ...
Purging configuration files for firebird3.0-common (3.0.1.32609.ds4-8) ...
Purging configuration files for imagemagick-common (8:6.9.6.2+dfsg-2) ...
Purging configuration files for firebird2.5-server-common (2.5.6.27020.ds4-3)
It s not yet production ready (like there s an infinite loop if dpkg returns error code 1 like from can t remove non empty folder ). But generally, ATTENTION: be very careful with typos and other mistakes if you want to use that code snippet, a false script performing changes on the package database might destroy the integrity of your system, and you don t want that to happen.

detect wild packages Like said above, installed Debian packages might be called wild if they have been downloaded from somewhere on the net and installed manually, like that is done from time to time on many systems. If you want to remove that whole class of packages again for any reason, the question would be how to detect them. A characteristic element is that there is no source connected to such a package, and that could be detected by Python scripting using again the bindings for the APT libraries. The package object doesn t have an associated method to query its source, because the origin is always connected to a specific package version, like some specific version might have come from security updates for example. The current version of a package can be queried with DepCache.get_candidate_ver() which returns a complex apt_pkg.Version object: 
>>> import apt_pkg
>>> apt_pkg.init()
>>> mycache = apt_pkg.Cache()
Reading package lists... Done
Building dependency tree
Reading state information... Done
>>> mydepcache = apt_pkg.DepCache(mycache)
>>> testpackage = mydepcache.get_candidate_ver(mycache['nano'])
>>> testpackage
<apt_pkg.Version object: Pkg:'nano' Ver:'2.7.4-1' Section:'editors'  Arch:'amd64' Size:484790 ISize:2092032 Hash:33578 ID:31706 Priority:2>
For version objects there is the method file_list available, which returns a list containing PackageFile() objects: 
>>> testpackage.file_list
[(<apt_pkg.PackageFile object: filename:'/var/lib/apt/lists/httpredir.debian.org_debian_dists_testing_main_binary-amd64_Packages'  a=testing,c=main,v=,o=Debian,l=Debian arch='amd64' site='httpredir.debian.org' IndexType='Debian Package Index' Size=38943764 ID:0>, 669901L)]
These file objects contain the index files which are associated with a specific package source (a downloaded package index), which could be read out easily (using a for-loop because there could be multiple file objects): 
>>> for files in testpackage.file_list:
...     print(files[0].filename)
/var/lib/apt/lists/httpredir.debian.org_debian_dists_testing_main_binary-amd64_Packages
That explains itself: the nano binary package on this amd64 computer comes from httpredir.debian.org/debian testing main. If a package is wild that means it was installed manually, so there is no associated index file to be found, but only /var/lib/dpkg/status (libcudnn5 is not in the official package archives but distributed by Nvidia as a .deb package): 
>>> testpackage2 = mydepcache.get_candidate_ver(mycache['libcudnn5'])
>>> for files in testpackage2.file_list:
...     print(files[0].filename)
/var/lib/dpkg/status
The simple trick now is to find all packages which have only /var/lib/dpkg/status as associated system file (that doesn t refer to what packages contain), an not an index file representing a package source. There s a little pitfall: that s truth also for virtual packages. But virtual packages commonly don t have an associated version (python-apt docs: to check whether a package is virtual; that is, it has no versions and is provided at least once ), and that can be queried by Package.has_versions. A filter to find out any packages that aren t virtual packages, are solely associated to one system file, and that file is /var/lib/dpkg/status, then goes like this: 
for package in cache.packages:
    if package.has_versions:
        version = mydepcache.get_candidate_ver(package)
        if len(version.file_list) == 1:
            if 'dpkg/status' in version.file_list[0][0].filename:
                print(package.name)
On my Debian testing system this puts out a quite interesting list. It lists all the wild packages like libcudnn5, but also packages which are recently not in testing because they have been temporarily removed by AUTORM due to release critical bugs. Then there s all the obsolete stuff which have been installed from the package archives once and then being forgotten like old kernel header packages ( obsolete packages in dselect). So this snippet brings up other stuff, too. Thus, this might be more experimental stuff so far, though.

7 February 2017

Carl Chenet: The Gitlab database incident and the Backup Checker project

The Gitlab.com database incident of 2017/01/31 and the resulting data loss reminded everyone (at least for the next days) how it s easy to lose data, even when you think all your systems are safe. Being really interested by the process of backing up data, I read with interest the report (kudos to the Gitlab company for being so transparent about it) and I was soooo excited to find the following sentence:
Regular backups seem to also only be taken once per 24 hours, though team-member-1 has not yet been able to figure out where they are stored. According to team-member-2 these don t appear to be working, producing files only a few bytes in size.
Whoa, guys! I m so sorry for you about the data loss, but from my point of view I was so excited to find a big FOSS company publicly admitting and communicating about a perfect use case for the Backup Checker project, a Free Software I ve been writing these last years. Data loss: nobody cares before, everybody cries after Usually people don t care about the backups. It s a serious business for web hosters and the backup team from big companies but otherwise and in other places, nobody cares. Usually everybody agrees about how backups are important but few people make them or install an automatized system to create backups and the day before, nobody verifies they are usable. The reason is obvious: it s totally boring, and in some cases e.g for large archives, difficult. Because verifying backups is boring for humans, I launched the Backup Checker project in order to automatize this task. Backup Checker offers a wide range of features, checking lots of different archives (tar. gz,bz2,xz , zip, tree of files and offer lots of different tests (hash sum, size equal, smaller/greater than , unix rights, ,). Have a look at the official documentation for a exhaustive list of features and possible tests. Automatize the controls of your backups with Backup Checker Checking your backups means to describe in a configuration file how a backup should be, e.g a gzipped database dump. You usually know about what size the archive is going to be, what the owner and the group owner should be. Even easier, with Backup Checker you can generate this list of criterias from an actual archive, and remove uneeded criterias to create a template you can re-use for different kind of archives. Ok, 2 minutes of your time for a real word example, I use an existing database sql dump in an tar.gz archive to automatically create the list describing this backup: 
$ backupchecker -G database-dump.tar.gz
$ cat database-dump.list
[archive]
mtime  1486480274.2923253
[files]
database.sql  =7854803 uid 1000 gid 1000 owner chaica group chaica mode 644 type f mtime 1486480253.0
Now, just remove parameters too precise from this list to get a backup template. Here is a possible result: 
[files]
database.sql  >6m uid 1000 gid 1000 mode 644 type f
We define here a template for the archive, meaning that the database.sql file in the archive should have a size greater than 6 megabytes, be owned by the user with the uid of 1000 and the group with a gid of 1000, this file should have the mode 644 and be a regular file. In order to use a template instead of the complete list, you also need to remove the sha512 from the .conf file. Pretty easy hmm? Ok, just for fun, lets replicate the part of the Gitlab.com database incident mentioned above and write an archive with an empty sql dump inside an archive: 
$ touch /tmp/database.sql && \
tar zcvf /tmp/database-dump.tar.gz /tmp/database.sql && \
cp /tmp/database-dump.tar.gz .
Now we launch Backup Checker with the previously created template. If you didn t change the name of database-dump.list file, the command should only be: 
$ backupchecker -C database-dump.conf
$ cat a.out 
WARNING:root:1 file smaller than expected while checking /tmp/article-backup-checker/database-dump.tar.gz: 
WARNING:root:database.sql size is 0. Should have been bigger than 6291456.
The automatized controls of Backup Checker trigger a warning in the log file. The empty sql dump has been identified inside the archive. A step further As you could read in this article, verifying some of your backups is not a time consuming task, given the fact you have a FOSS project dedicated to this task, with an easy way to realize a template of your backups and to use it. This article provided a really simple example of such a use case, the Backup Checker has lots of features to offer when verifying your backups. Read the official documentation for more complete descriptions of the available possibilities. Data loss, especially for projets storing user data is always a terrible event in the life of an organization. Lets try to learn from mistakes which could happen to anyone and build better backup systems. More information about the Backup Checker project

2 February 2017

Paul Wise: FLOSS Activities January 2017

Changes

Issues

Review

Administration
  • Debian: reboot 1 non-responsive VM, redirect 2 users to support channels, redirect 1 contributor to xkb upstream, redirect 1 potential contributor, redirect 1 bug reporter to mirror team, ping 7 folks about restarting processes with upgraded libs, manually restart the sectracker process due to upgraded libs, restart the package tracker process due to upgraded libs, investigate failures connecting to the XMPP service, investigate /dev/shm issue on abel.d.o, clean up after rename of the fedmsg group.
  • Debian mentors: lintian/security updates & reboot
  • Debian packages: deploy 2 contributions to the live server
  • Debian wiki: unblacklist 1 IP address, whitelist 10 email addresses, disable 18 accounts with bouncing email, update email for 2 accounts with bouncing email, reported 1 Debian member as MIA, redirect 1 user to support channels, add 4 domains to the whitelist.
  • Reproducible builds: rescheduled Debian pyxplot:amd64/unstable for themill.
  • Openmoko: security updates & reboots.

Debian derivatives
  • Send the annual activity ping mail.
  • Happy new year messages on IRC, forward to the list.
  • Note that SerbianLinux does not provide source packages.
  • Expand URL shortener on SerbianLinux page.
  • Invite PelicanHPC, Netrunner, DietPi, Hamara Linux (on IRC), BitKey to the census.
  • Add research publications link to the census template
  • Fix Symbiosis sources.list
  • Enquired about SalentOS downtime
  • Fixed and removed some 404 BlankOn links (blog, English homepage)
  • Fixed changes to AstraLinux sources.list
  • Welcome Netrunner to the census

Sponsors I renewed my support of Software Freedom Conservancy. The openchange 1:2.2-6+deb8u1 upload was sponsored by my employer. All other work was done on a volunteer basis.

1 February 2017

Antoine Beaupr : My free software activities, January 2017

manpages.debian.org launched The debmans package I had so lovingly worked on last month is now officially abandoned. It turns out that another developer, Michael Stapelberg wrote his own implementation from scratch, called debiman. Both software share a similar design: they are both static site generators that parse an existing archive and call another tool to convert manpages into HTML. We even both settled on the same converter (mdoc). But while I wrote debmans in Python, debiman is written in Go. debiman also seems much faster, being written with concurrency in mind from the start. Finally, debiman is more feature complete: it properly deals with conflicting packages, localization and all sorts redirections. Heck, it even has a pretty logo, how can I compete? While debmans was written first and was in the process of being deployed, I had to give it up. It was a frustrating experience because I felt I wasted a lot of time working on software that ended up being discarded, especially because I put so much work on it, creating extensive documentation, an almost complete test suite and even filing a detailed core infrastructure best practices report In the end, I think that was the right choice: debiman seemed clearly superior and the best tool should win. Plus, it meant less work for me: Michael and Javier (the previous manpages.debian.org maintainer) did all the work of putting the site online. I also learned a lot about the CII best practices program, flask, click and, ultimately, the Go programming language itself, which I'll refer to as Golang for brievity. debiman definitely brought Golang into the spotlight for me. I had looked at Go before, but it seemed to be yet another language. But seeing Michael beat me to rebuilding the service really made me look at it again more seriously. While I really appreciate Python and I will probably still use it as my language of choice for GUI work and smaller scripts, but for daemons, network programs and servers, I will seriously consider Golang in the future. The site is now online at https://manpages.debian.org/. I even got credited in the about page which makes up for the disappointment.

Wallabako downloads Wallabag articles on my Kobo e-reader This obviously brings me to the latest project I worked on, Wallabako, my first Golang program ever. Wallabako is basically a client for the Wallabag application, which is a free software "read it later" service, an alternative to the likes of Pocket, Pinboard or Evernote. Back in April, I had looked downloading my "unread articles" into my new ebook reader, going through convoluted ways like implementing OPDS support into Wallabag, which turned out to be too difficult. Instead, I used this as an opportunity to learn Golang. After reading the quite readable golang specification over the weekend, I found the language to be quite elegant and simple, yet very powerful. Golang feels like C, but built with concurrency and memory (and to a certain extent, type) safety in mind, along with a novel approach to OO programming. The fact that everything can be compiled in one neat little static binary was also a key feature in selecting golang for this project, as I do not have much control over the platform my E-Reader is running: it is a Linux machine running under the ARM architecture, but beyond that, there isn't much available. I couldn't afford to ship a Python interpreter in there and while there are solutions there like pyinstaller, I felt that it may be so easy to deploy on ARM. The borg team had trouble building a ARM binary, restoring to tricks like building on a Raspberry PI or inside an emulator. In comparison, the native go compiler supports cross-compilation out of the box through a simple environment variable. So far Wallabako works amazingly well: when I "bag" a new article in Wallabag, either from my phone or my web browser, it will show up on my ebook reader then next time I open the wifi. I still need to "tap" the screen to fake the insertion of the USB cable, but we're working on automating that. I also need to make the installation of the software much easier and improve the documentation, because so far it's unlikely that someone unfamiliar with Kobo hardware hacking will be able to install it.

Other work According to Github, I filed a bunch of bugs all over the place (25 issues in 16 repositories), sent patches everywhere (13 pull requests in 6 repositories), and tried to fix everythin (created 38 commits in 7 repositories). Note that excludes most of my work, which happens on Gitlab. January was still a very busy month, especially considering I had an accident which kept me mostly offline for about a week. Here are some details on specific projects.

Stressant and a new computer I revived the stressant project and got a new computer. This is be covered in a separate article.

Linkchecker forked After much discussions, it was decided to fork the linkchecker project, which now lives in its own organization. I still have to write community guidelines and figure out the best way to maintain a stable branch, but I am hopeful that the community will pick up the project as multiple people volunteer to co-maintain the project. There has already been pull requests and issues reported, so that's a good sign.

Feed2tweet refresh I re-rolled my pull requests to the feed2tweet project: last time they were closed before I had time to rebase them. The author was okay with me re-submitting them, but he hasn't commented, reviewed or merged the patches yet so I am worried they will be dropped again. At that point, I would more likely rewrite this from scratch than try to collaborate with someone that is clearly not interested in doing so...

Debian uploads

Debian Long Term Support (LTS) This is my 10th month working on Debian LTS, started by Raphael Hertzog at Freexian. I took two months off last summer, which means it's actually been a year of work on the LTS project. This month I worked on a few issues, but they were big issues, so they took a lot of time. I have done a lot of work trying to backport the heading sanitization patches for CVE-2016-8743. The full report explain all the gritty details, but I ran out of time and couldn't upload the final version either. The issue mostly affects Apache servers in proxy configurations so it's not so severe as to warrant an immediate upload anyways. A lot of my time was spent battling the tiff package. The report mentions fixes for 15 CVEs and I uploaded the result in the DLA-795-1 advisory. I also worked on a small update to graphics magic for CVE-2016-9830 that is still pending because the issue is minor and we're waiting for more to pile up. See the full report for details. Finally, there was a small discussion surrounding tools to use when building and testing update to LTS packages. The resulting conversation was interesting, but it showed that we have a big documentation problem in the Debian project. There are a lot of tools, and the documentation is old and distributed everywhere. Every time I want to contribute something to the documentation, I never know where to start or go. This is why I wrote a separate debian development guide instead of contributing to existing documentation...

18 January 2017

Jonathan Dowland: RetroPie, NES Classic and Bluetooth peripherals

I wanted to write a more in-depth post about RetroPie the Retro Gaming Appliance OS for Raspberry Pis, either technically or more positively, but unfortunately I don't have much positive to write. What I hoped for was a nice appliance that I could use to play old games from the comfort of my sofa. Unfortunately, nine times out of ten, I had a malfunctioning Linux machine and the time I'd set aside for jumping on goombas was being spent trying to figure out why bluetooth wasn't working. I have enough opportunities for that already, both at work and at home. I feel a little bad complaining about an open source, volunteer project: in its defence I can say that it is iterating fast and the two versions I tried in a relatively short time span were rapidly different. So hopefully a lot of my woes will eventually be fixed. I've also read a lot of other people get on with it just fine. Instead, I decided the Nintendo Classic NES Mini was the plug-and-play appliance for me. Alas, it became the "must have" Christmas toy for 2016 and impossible to obtain for the recommended retail price. I did succeed in finding one in stock at Toys R Us online at one point, only to have the checkout process break and my order not go through. Checking Stock Informer afterwards, that particular window of opportunity was only 5 minutes wide. So no NES classic for me! My adventures in RetroPie weren't entirely fruitless, thankfully: I discovered two really nice pieces of hardware.
ThinkPad Keyboard ThinkPad Keyboard
The first is Lenovo's ThinkPad Compact Bluetooth Keyboard with TrackPoint, a very compact but pleasant to use Bluetooth keyboard including a trackpoint. I miss the trackpoint from my days as a Thinkpad laptop user. Having a keyboard and mouse combo in such a small package is excellent. My only two complaints would be the price (I was lucky to get one cheaper on eBay) and the fact it's bluetooth only: there's a micro-USB port for charging, but it would be nice if it could be used as a USB keyboard too. There's a separate, cheaper USB model.
8bitdo SFC30 8bitdo SFC30
The second neat device is a clone of the SNES gamepad by HK company 8bitdo called the SFC30. This looks and feels very much like the classic Nintendo SNES controller, albeit slightly thicker from front to back. It can be used in a whole range of different modes, including attached USB; Bluetooth pretending to be a keyboard; Bluetooth pretending to be a controller; and a bunch of other special modes designed to work with iOS or Android devices in various configurations. The manufacturer seem to be actively working on firmware updates to further enhance the controller. The firmware is presently closed source, but it would not be impossible to write an open source firmware for it (some people have figured out the basis for the official firmware). I like the SFC30 enough that I spent some time trying to get it working for various versions of Doom. There are just enough buttons to control a 2.5D game like Doom, whereas something like Quake or a more modern shooter would not work so well. I added support for several 8bitdo controllers directly into Chocolate Doom (available from 2.3.0 onwards) and into SDL2, a popular library for game development, which I think is used by Steam, so Steam games may all gain SFC30 support in the future too.

30 December 2016

Antoine Beaupr : My free software activities, November and December 2016

Debian Long Term Support (LTS) Those were 8th and 9th months working on Debian LTS started by Raphael Hertzog at Freexian. I had trouble resuming work in November as I had taken a long break during the month and started looking at issues only during the last week of November.

Imagemagick, again I have, again, spent a significant amount of time fighting the ImageMagick (IM) codebase. About 15 more vulnerabilities were found since the last upload, which resulted in DLA-756-1. In the advisory, I unfortunately forgot to mention CVE-2016-8677 and CVE-2016-9559, something that was noticed by my colleague Roberto after the upload... More details about the upload are available in the announcement. When you consider that I worked on IM back in october, which lead to an upload near the end of November covering around 80 more vulnerabilities, it doesn't look good for the project at all. Of the 15 vulnerabilities I worked on, only 6 had CVEs assigned and I had to request CVEs for the other 9 vulnerabilities plus 11 more that were still unassigned. This lead to the assignment of 25 distinct CVE identifiers as a lot of issues were found to be distinct enough to warrant their own CVEs. One could also question how many of those issues affect the fork, Graphicsmagick. A lot of the vulnerabilities were found through fuzzing searches that may not have been tested on Graphicsmagick. It seems clear to me that a public corpus of test data should be available to test regressions and cross-project vulnerabilities. It's already hard enough to track issues withing IM itself, I can't imagine what it would be for the fork to keep track of those issues, especially since upstream doesn't systematically request CVEs for issues that they find, a questionable practice considering the number of issues we all need to keep track of.

Nagios I have also worked on the Nagios package and produced DLA 751-1 which fixed two fairly major issues (CVE-2016-9565 and CVE-2016-9566) that could allow remote root access under certain conditions. Fortunately, the restricted permissions setup by default in the Debian package made both exploits limited to information disclosure and privilege escalation if the debug log is enabled. This says a lot about how proper Debian packaging can help in limiting the attack surface of certain vulnerabilities. It was also "interesting" to have to re-learn dpatch to add patches to the package: I regret not converting it to quilt, as the operation is simple and quilt is so much easier to use. People new to Debian packaging may be curious to learn about the staggering number of patching systems historically used in Debian. On that topic, I started a conversation about how much we want to reuse existing frameworks when we work on those odd packages, and the feedback was interesting. Basically, the answer is "it depends"...

NSS I had already worked on the package in November and continued the work in December. Most of the work was done by Raphael, which fixed a lot of issues with the test suite. I tried to wrap this up by fixing CVE-2016-9074, the build on armel and the test suite. Unfortunately, I had to stop again because I ran out of hours and the fips test suite was still failing, but fortunately Raphael was able to complete the work with DLA-759-1. As things stand now, the package is in better shape than in other suites as tests (Debian bug #806639) and autopkgtest (Debian bug #806207) are still not shipped in the sid or stable releases.

Other work For the second time, I forgot to formally assign myself a package before working on it, which meant that I wasted part of my hours working on the monit package. Those hours, of course, were not counted in my regular hours. I still spent some time reviewing mejo's patch to ensure it was done properly and it turned out we both made similar patches working independently, always a good sign. As I reported in my preliminary November report, I have also triaged issues in libxml2, ntp, openssl and tiff. Finally, I should mention my short review of the phpMyAdmin upload, among the many posts i sent to the LTS mailing list.

Other free software work One reason why I had so much trouble getting paid work done in November is that I was busy with unpaid work...

manpages.debian.org A major time hole for me was trying to tackle the manpages.debian.org service, which had been offline since August. After a thorough evaluation of the available codebases, I figured the problem space wasn't so hard and it was worth trying to do an implementation from scratch. The result is a tool called debmans. It took, obviously, way longer than I expected, as I experimented with Python libraries I had been keeping an eye on for a while. For the commanline interface, I used the click library, which is really a breeze to use, but a bit heavy for smaller scripts. For a web search service prototype, I looked at flask, which was also very interesting, as it is light and simple enough to use that I could get started quickly. It also, surprisingly, fares pretty well in the global TechEmpower benchmarking tests. Those interested in those tools may want to look at the source code, in particular the main command (using an interesting pattern itself, __main__.py) and the search prototype. Debmans is the first project for which I have tried the CII Best Practices Badge program, an interesting questionnaire to review best practices in software engineering. It is an excellent checklist I recommend every project manager and programmer to get familiar with. I still need to complete my work on Debmans: as I write this, I couldn't get access to the new server the DSA team setup for this purpose. It was a bit of a frustrating experience to wait for all the bits to get into place while I had a product ready to test. In the end, the existing manpages.d.o maintainer decided to deploy the existing codebase on the new server while the necessary dependencies are installed and accesses are granted. There's obviously still a bunch of work to be done for this to be running in production so I have postponed all this work to January. My hope is that this tool can be reused by other distributions, but after talking with Ubuntu folks, I am not holding my breath: it seems everyone has something that is "good enough" and that they don't want to break it...

Monkeysign I spent a good chunk of time giving a kick in the Monkeysign project, with the 2.2.2 release, which features contributions from two other developers, which may be a record for a single release. I am especially happy to have adopted a new code of conduct - it has been an interesting process to adapt the code of conduct for such a relatively small project. Monkeysign is becoming a bit of a template on how to do things properly for my Python projects: documentation on readthedocs.org including a code of conduct, support and contribution information, and so on. Even though the code now looks a bit old to me and I am embarrassed to read certain parts, I still think it is a solid project that is useful for a lot of people. I would love to have more time to spend on it.

LWN publishing As you may have noticed if you follow this blog, I have started publishing articles for the LWN magazine, filed here under the lwn tag. It is a way for me to actually get paid for some of my blogging work that used to be done for free. Reports like this one, for example, take up a significant amount of my time and are done without being paid. Converting parts of this work into paid work is part of my recent effort to reduce the amount of time I spend on the computer. An funny note: I always found the layout of the site to be a bit odd, until I looked at my articles posted there in a different web browser, which didn't have my normal ad blocker configuration. It turns out LWN uses ads, and Google ones too, which surprised me. I definitely didn't want to publish my work under banner ads, and will never do so on this blog. But it seems fair that, since I get paid for this work, there is some sort of revenue stream associated with it. If you prefer to see my work without ads, you can wait for it to be published here or become a subscriber which allows you to get rid of the ads on the site. My experience with LWN is great: they're great folks, and very supportive. It's my first experience with a real editor and it really pushed me in improving my writing to make better articles that I normally would here. Thanks to the LWN folks for their support! Expect more of those quality articles in 2017.

Debian packaging I have added a few packages to the Debian archive:
  • magic-wormhole: easy file-transfer tool, co-maintained with Jamie Rollins
  • slop: screenshot tool
  • xininfo: utility used by teiler
  • teiler (currently in NEW): GUI for screenshot and screencast tools
I have also updated sopel and atheme-services.

Other work Against my better judgment, I worked again on the borg project. This time I tried to improve the documentation, after a friend asked me for help on "how to make a quick backup". I realized I didn't have any good primer to send regular, non-sysadmin users to and figured that, instead of writing a new one, I could improve the upstream documentation instead. I generated a surprising 18 commits of documentation during that time, mainly to fix display issues and streamline the documentation. My final attempt at refactoring the docs eventually failed, unfortunately, again reminding me of the difficulty I have in collaborating on that project. I am not sure I succeeded in making the project more attractive to non-technical users, but maybe that's okay too: borg is a fairly advanced project and not currently aimed at such a public. This is yet another project I am thinking of creating: a metabackup program like backupninja that would implement the vision created by liw in his A vision for backups in Debian post, which was discarded by the Borg project. Github also tells me that I have opened 19 issues in 14 different repositories in November. I would like to particularly bring your attention to the linkchecker project which seems to be dead upstream and for which I am looking for collaborators in order to create a healthy fork. Finally, I started on reviving the stressant project and changing all my passwords, stay tuned for more!

26 December 2016

Russ Allbery: Apologies for RSS feed duplicates

Sorry about the duplicates showing up in your feed or in e-mail, for those who saw them. I changed the canonical URLs of my journal entries to use https instead of http and forgot that would confuse a lot of RSS readers. Didn't mean to suddenly give you all a replay of the last 15 entries! This should be a one-time change and not happen again. (Although I need to find or fix a good broken link checker and then track down the rest of the URLs in my web site that aren't using https.)

31 October 2016

Chris Lamb: Free software activities in October 2016

Here is my monthly update covering what I have been doing in the free software world (previously):

Debian & Reproducible builds

Whilst anyone can inspect the source code of free software for malicious flaws, most GNU/Linux distributions provide binary (or "compiled") packages to end users. The motivation behind the Reproducible Builds effort is to allow verification that no flaws have been introduced either maliciously and accidentally during this compilation process by promising identical binary packages are always generated from a given source.

  • Presented a talk entitled "Reproducible Builds" talk at Software Freedom Kosova, in Prishtina, Republic of Kosovo.

  • I filed my 2,500th bug in the Debian BTS: #840972: golang-google-appengine: accesses the internet during build.

  • In order to build packages reproducibly, one not only needs identical sources but also some external and sharable definition of the environment used for a particular build, stipulating such things such as the version numbers of the required build-dependencies. It is not currently clear how to handle these .buildinfo files after the archive software has processed them and how to make them available to the world so I started development on a proof-of-concept server to see what issues arise in practice. It is available at buildinfo.debian.net.

  • Chaired an IRC meeting and ran a poll to determine a regular time .

  • Submitted two design proposals to our wiki page.

  • Improvements to our tests.reproducible-builds.org testing framework:

    • Move regular "Scheduled in..." messages to the #debian-reproducible-changes IRC channel.
    • Use our log_info method instead of manual echo calls.
    • Correct an "all sources packages" "all source packages" typo.
    • Submit .buildinfo files to buildinfo.debian.net.
    • Create GPG key on nodes for buildinfo.debian.net at deploy time, not "lazily".

My work in the Reproducible Builds project was also covered in our weekly reports. (#75, #76, #77 & #78).

I also submitted 14 patches to fix specific reproducibility issues in bio-eagle, cf-python, fastx-toolkit, fpga-icestorm, http-icons, lambda-align, mypy, playitslowly, seabios, stumpwm, sympa, tj3, wims-help & xotcl.
Debian LTS

This month I have been paid to work 13 hours on Debian Long Term Support (LTS). In that time I did the following:
  • Seven days of "frontdesk" duties, triaging CVEs, etc.
  • Issued DLA 647-1 for freeimage correcting an out-of-bounds write vulnerability in the XMP image handling functionality.
  • Issued DLA 649-1 for python-django fixing a possible CSRF protection bypass on sites that use Google Analytics.
  • Issued DLA 654-1 for libxfixes preventing an integer overflow when a malicious client sent INT_MAX as a "length".
  • Issued DLA 662-1 for quagga correcting a programming error where two constants were confused that could cause stack overrun in IPv6 routing code.
  • Issued DLA 688-1 for cairo to prevent a DoS attack where a malicious SVG could generate invalid pointers.
Uploads
  • gunicorn:
    • 19.6.0-7 Set supplementary groups when changing uid, add an example systemd .service file to gunicorn-examples, and expand README.Debian to make it clearer what to do now that /etc/gunicorn.d has been removed.
    • 19.6.0-8 Correct previous supplementary groups patch to be compatible with Python 3.
  • redis:
    • 3:3.2.4-2 Ensure that sentinel's configuration actually writes to a pidfile location so that systemd can detect that the daemon has started.
    • 3:3.2.5-1 New upstream release.
  • libfiu:
    • 0.94-8 Fix FTBFS under Bash due to lack of && in debian/rules.
    • 0.94-9 Ensure the build is reproducible by sorting injected modules.
  • aptfs (2:0.8-2) Minor cosmetic changes.

NMUs
  • libxml-dumper-perl (0.81-1.2) Move away from a unsupported debhelper compat level 4.
  • netatalk (2.2.5-1.1) Drop build-dependency on hardening-includes.

QA uploads
  • anon-proxy (00.05.38+20081230-4) Move to a supported debhelper compatibility level 9.
  • ara (1.0.32) Make the build reproducible.
  • binutils-m68hc1x (1:2.18-8) Make the build reproducible & move to a supported debhelper compatibility level.
  • fracplanet (0.4.0-5) Make the build reproducible.
  • libnss-ldap (265-5) Make the build reproducible.
  • python-uniconvertor (1.1.5-3) Fix an "option release requires an argument" FTBFS. (#839375)
  • ripole (0.2.0+20081101.0215-3) Actually include the ripole binary in package. (#839919) & enable hardening flags.
  • twitter-bootstrap (2.0.2+dfsg-10) Fix incorrect copyright formatting when building under Bash. (#824592)
  • zpaq (1.10-3) Make the build reproducible.
Debian FTP Team

As a Debian FTP assistant I ACCEPTed 147 packages: ace-link, amazon-s2n, avy, basez, bootstrap-vz, bucklespring, camitk, carettah, cf-python, debian-reference, dfcgen-gtk, efivar, entropybroker, fakesleep, gall, game-data-packager, gitano, glare, gnome-panel, gnome-shell-extension-dashtodock, gnome-shell-extension-refreshwifi, gnome-shell-extension-remove-dropdown-arrows, golang-github-gogits-go-gogs-client, golang-github-gucumber-gucumber, golang-github-hlandau-buildinfo, golang-github-hlandau-dexlogconfig, golang-github-hlandau-goutils, golang-github-influxdata-toml, golang-github-jacobsa-crypto, golang-github-kjk-lzma, golang-github-miekg-dns, golang-github-minio-sha256-simd, golang-github-nfnt-resize, golang-github-nicksnyder-go-i18n, golang-github-pointlander-compress, golang-github-pointlander-jetset, golang-github-pointlander-peg, golang-github-rfjakob-eme, golang-github-thecreeper-go-notify, golang-github-twstrike-gotk3adapter, golang-github-unknwon-goconfig, golang-gopkg-dancannon-gorethink.v1, golang-petname, haskell-argon2, haskell-binary-parsers, haskell-bindings-dsl, haskell-deriving-compat, haskell-hackage-security, haskell-hcwiid, haskell-hsopenssl-x509-system, haskell-megaparsec, haskell-mono-traversable-instances, haskell-prim-uniq, haskell-raaz, haskell-readable, haskell-readline, haskell-relational-record, haskell-safe-exceptions, haskell-servant-client, haskell-token-bucket, haskell-zxcvbn-c, irclog2html, ironic-ui, lace, ledger, libdancer2-plugin-passphrase-perl, libdatetime-calendar-julian-perl, libdbix-class-optimisticlocking-perl, libdbix-class-schema-config-perl, libgeo-constants-perl, libgeo-ellipsoids-perl, libgeo-functions-perl, libgeo-inverse-perl, libio-async-loop-mojo-perl, libmojolicious-plugin-assetpack-perl, libmojolicious-plugin-renderfile-perl, libparams-validationcompiler-perl, libspecio-perl, libtest-time-perl, libtest2-plugin-nowarnings-perl, linux, lua-scrypt, mono, mutt-vc-query, neutron, node-ansi-font, node-buffer-equal, node-defaults, node-formatio, node-fs-exists-sync, node-fs.realpath, node-is-buffer, node-jison-lex, node-jju, node-jsonstream, node-kind-of, node-lex-parser, node-lolex, node-loud-rejection, node-random-bytes, node-randombytes, node-regex-not, node-repeat-string, node-samsam, node-set-value, node-source-map-support, node-spdx-correct, node-static-extend, node-test, node-to-object-path, node-type-check, node-typescript, node-unset-value, nutsqlite, opencv, openssl1.0, panoramisk, perl6, pg-rage-terminator, pg8000, plv8, puppet-module-oslo, pymoc, pyramid-jinja2, python-bitbucket-api, python-ceilometermiddleware, python-configshell-fb, python-ewmh, python-gimmik, python-jsbeautifier, python-opcua, python-pyldap, python-s3transfer, python-testing.common.database, python-testing.mysqld, python-testing.postgresql, python-wheezy.template, qspeakers, r-cran-nleqslv, recommonmark, rolo, shim, swift-im, tendermint-go-clist, tongue, uftrace & zaqar-ui.

6 September 2016

Markus Koschany: My Free Software Activities in August 2016

Welcome to gambaru.de. Here is my monthly report that covers what I have been doing for Debian. If you re interested in Android, Java, Games and LTS topics, this might be interesting for you. Debian Android Debian Games Debian Java Debian LTS This was my seventh month as a paid contributor and I have been paid to work 14,75 hours on Debian LTS, a project started by Rapha l Hertzog. In that time I did the following: Non-maintainer uploads QA

5 September 2016

Chris Lamb: How to write your first Lintian check

Lintian's humble description of "Debian package checker" belies its importance within the Debian GNU/Linux project. An extensive static analysis tool, it's not only used by the vast majority of developers, falling foul of some of its checks even cause uploads to be automatically rejected by the archive maintenance software. As you may have read in my recent monthly report, I've recently been hacking on Lintian itself. In particular:

However, this rest of this post will go through the steps needed to start contributing yourself. To demonstrate this I will be walking through submitting a patch for bug #831864 which warns about Python packages that ship .coverage files generated by Coverage.py.
Getting started First, let's obtain the Lintian sources and create a branch for our work: 
$ git clone https://anonscm.debian.org/git/lintian/lintian.git
[ ]
$ cd lintian
$ git checkout -b warn-about-dotcoverage-files
Switched to a new branch 'warn-about-dotcoverage-files'
The most interesting files are under checks/*: 
$ ls -l checks/   head -n 9
total 1356
-rw-r--r-- 1 lamby lamby  6393 Jul 29 14:19 apache2.desc
-rw-r--r-- 1 lamby lamby  8619 Jul 29 14:19 apache2.pm
-rw-r--r-- 1 lamby lamby  1956 Jul 29 14:19 application-not-library.desc
-rw-r--r-- 1 lamby lamby  3285 Jul 29 14:19 application-not-library.pm
-rw-r--r-- 1 lamby lamby   544 Jul 29 14:19 automake.desc
-rw-r--r-- 1 lamby lamby  1354 Jul 29 14:19 automake.pm
-rw-r--r-- 1 lamby lamby 19506 Jul 29 14:19 binaries.desc
-rw-r--r-- 1 lamby lamby 25204 Jul 29 14:19 binaries.pm
-rw-r--r-- 1 lamby lamby 15641 Aug 24 21:42 changelog-file.desc
-rw-r--r-- 1 lamby lamby 19606 Jul 29 14:19 changelog-file.pm
Note that the files are in pairs; a foo.desc file that contains description of the tags and a sibling foo.pm Perl module that actually performs the checks.

Let's add our new tag before we go any further. After poking around, it looks like files. pm,desc would be most appropriate, so we'll add our new tag definition to files.desc: 
Tag: package-contains-python-coverage-file
Severity: normal
Certainty: certain
Info: The package contains a file that looks like output from the Python
 coverage.py tool.  These are generated by python ,3 -coverage during a test
 run, noting which parts of the code have been executed.  They can then be
 subsequently analyzed to identify code that could have been executed but was
 not.
 .
 As they are are unlikely to be of utility to end-users, these files should
 be removed from the package.
The Severity and Certainty fields are documented in the manual. Note the convention of using double spaces after full stops in the Info section.
Extending the testsuite Lintian has many moving parts based on regular expressions and other subtle logic, so it's especially important to provide tests in order to handle edge cases and to catch any regressions in the future. We create tests by combining a tiny Debian package that will deliberately violate our check, along with some metadata and the expected output of running Lintian against this package. The tests themselves are stored under t/tests. There may be an existing test that it would be more appropriate to extend, but I've gone with creating a new directory called files-python-coverage: 
$ mkdir -p t/tests/files-python-coverage
$ cd t/tests/files-python-coverage
First, we create a simple package, installing dummy file to trigger the check: 
$ mkdir -p debian/debian
$ touch debian/.coverage
$ echo ".coverage /usr/share/files-python-coverage" > debian/debian/install
Note that we do not need a debian/rules file as long as we do not deviate from a "skeleton" debhelper style. We then add the aforementioned metadata to t/tests/files-python-coverage/desc: 
Testname: files-python-coverage
Sequence: 6000
Version: 1.0
Description: Check for Python .coverage files
Test-For:
 package-contains-python-coverage-file
and the expected warning to t/tests/files-python-coverage/tags: 
$ echo "W: files-python-coverage: package-contains-python-coverage-file" \
      "usr/share/files-python-coverage/.coverage" > tags

When we run the testsuite, it should fail because we don't emit the check yet: 
$ cd $(git rev-parse --show-toplevel)
$ debian/rules runtests onlyrun=tag:package-contains-python-coverage-file
[ ]
--- t/tests/files-python-coverage/tags
+++ debian/test-out/tests/files-python-coverage/tags.files-python-coverage
@@ -1 +0,0 @@
-W: files-python-coverage: package-contains-python-coverage-file usr/share/files-python-coverage/.coverage
fail tests::files-python-coverage: output differs!
Failed tests (1)
    tests::files-python-coverage
debian/rules:48: recipe for target 'runtests' failed
make: *** [runtests] Error 1
$ echo $?
1
Specifying onlyrun= means we only run the tests that are designed to trigger this tag rather than the whole testsuite. This is controlled by the Test-For key in our desc file, not by scanning the tags files. This recipe for creating a testcase could be used when submitting a regular bug against Lintian providing a failing testcase not only clarifies misunderstandings resulting from the use of natural language, it also makes it easier, quicker and safer to correct the offending code itself.
Emitting the tag Now, let's actually implement the check: 
             tag 'package-installs-python-egg', $file;
          
+        # ---------------- .coverage (coverage.py output)
+        if ($file->basename eq ".coverage")  
+            tag 'package-contains-python-coverage-file', $file;
+         
         # ---------------- /usr/lib/site-python
Our testsuite now passes: 
$ debian/rules runtests onlyrun=tag:package-contains-python-coverage-file
private/generate-profiles.pl
.... running tests ....
mkdir -p "debian/test-out"
t/runtests -k -j 9 t "debian/test-out" tag:package-contains-python-coverage-file
ENV[PATH]=[..]
pass tests::files-python-coverage
if [ "tag:package-contains-python-coverage-file" = "" ]; then touch runtests; fi
$ echo $?
0
Submitting the patch Lastly, we create a patch for submission to the bug tracking system: 
$ git commit -a -m "c/files: Warn about Python packages which ship" \
      "coverage.py information. (Closes: #831864)"
$ git format-patch HEAD~
0001-c-files-Warn-about-Python-packages-which-ship-covera.patch
and we finally attach it to the existing bug: 
To: 831864@bugs.debian.org
Cc: 831864-submitter@bugs.debian.org
Bcc: control@bugs.debian.org
tags 831864 + patch
thanks
Patch attached.
/lamby

Summary I hope this post will encourage at some extra contributions towards this important tool. (Be aware that I'm not a Lintian maintainer, so not only should you not treat anything here as gospel and expect this post may be edited over time if clarifications arise.)

31 August 2016

Chris Lamb: Free software activities in August 2016

Here is my monthly update covering what I have been doing in the free software world (previously):

Reproducible builds

Whilst anyone can inspect the source code of free software for malicious flaws, most Linux distributions provide binary (or "compiled") packages to end users. The motivation behind the Reproducible Builds effort is to allow verification that no flaws have been introduced either maliciously and accidentally during this compilation process by promising identical binary packages are always generated from a given source.

Diffoscope diffoscope is our "diff on steroids" that will not only recursively unpack archives but will transform binary formats into human-readable forms in order to compare them:
  • Added a command-line interface to the try.diffoscope.org web service.
  • Added a JSON comparator.
  • In the HTML output, highlight lines when hovering to make it easier to visually track.
  • Ensure that we pass str types to our Difference class, otherwise we can't be sure we can render them later.
  • Testsuite improvements:
    • Generate test coverage reports.
    • Add tests for Haskell and GitIndex comparators.
    • Completely refactored all of the comparator tests, extracting out commonly-used routines.
    • Confirm rendering of text and HTML presenters when checking non-existing files.
    • Dropped a squashfs test as it was simply too unreliable and/or has too many requirements to satisfy.
  • A large number of miscellaneous cleanups, including:
    • Reworking the comparator setup/preference internals by dynamically importing classes via a single list.
    • Split exceptions out into dedicated diffoscope.exc module.
    • Tidying the PROVIDERS dict in diffoscope/__init__.py.
    • Use html.escape over xml.sax.saxutils.escape, cgi.escape, etc.
    • Removing hard-coding of manual page targets names in debian/rules.
    • Specify all string format arguments as logging function parameters, not using interpolation.
    • Tidying imports, correcting indentation levels and drop unnecessary whitespace.

disorderfs disorderfs is our FUSE filesystem that deliberately introduces nondeterminism in system calls such as readdir(3).
  • Added a testsuite to prevent regressions. (f124965)
  • Added a --sort-dirents=yes no option for forcing deterministic ordering. (2aae325)

Other
  • Improved strip-nondeterminism, our tool to remove specific nondeterministic information after a build:
    • Match more styles of Java .properties files.
    • Remove hyphen from "non-determinism" and "non-deterministic" throughout package for consistency.
  • Improvements to our testing infrastucture:
    • Improve the top-level navigation so that we can always get back to "home" of a package.
    • Give expandable elements cursor: pointer CSS styling to highlight they are clickable.
    • Drop various trailing underlined whitespaces after links.
    • Explicitly log that build was successful or not.
    • Various code-quality improvements, including prefering str.format over concatentation.
  • Miscellaneous updates to our filter-packages internal tool:
    • Add --random=N and --url options.
    • Add support for --show=comments.
    • Correct ordering so that --show-version runs after --filter-ftbfs.
    • Rename --show-ftbfs to --filter-ftbfs and --show-version to --show=version.
  • Created a proof-of-concept reproducible-utils package to contain commonly-used snippets aimed at developers wishing to make their packages reproducible.


I also submitted 92 patches to fix specific reproducibility issues in advi, amora-server, apt-cacher-ng, ara, argyll, audiotools, bam, bedtools, binutils-m68hc1x, botan1.10, broccoli, congress, cookiecutter, dacs, dapl, dateutils, ddd, dicom3tools, dispcalgui, dnssec-trigger, echoping, eekboek, emacspeak, eyed3, fdroidserver, flashrom, fntsample, forkstat, gkrellm, gkrellm, gnunet-gtk, handbrake, hardinfo, ircd-irc2, ircd-ircu, jack-audio-connection-kit, jpy, kxmlgui, libbson, libdc0, libdevel-cover-perl, libfm, libpam-ldap, libquvi, librep, lilyterm, mozvoikko, mp4h, mp4v2, myghty, n2n, nagios-nrpe, nikwi, nmh, nsnake, openhackware, pd-pdstring, phpab, phpdox, phpldapadmin, pixelmed-codec, pleiades, pybit, pygtksourceview, pyicu, python-attrs, python-gflags, quvi, radare2, rc, rest2web, roaraudio, rt-extension-customfieldsonupdate, ruby-compass, ruby-pg, sheepdog, tf5, ttf-tiresias, ttf-tiresias, tuxpaint, tuxpaint-config, twitter-bootstrap3, udpcast, uhub, valknut, varnish, vips, vit, wims, winswitch, wmweather+ & xshisen.

Debian GNU/Linux
Debian LTS

This month I have been paid to work 15 hours on Debian Long Term Support (LTS). In that time I did the following:
  • "Frontdesk" duties, triaging CVEs, etc.
  • Authored the patch & issued DLA 596-1 for extplorer, a web-based file manager, fixing an archive traversal exploit.
  • Issued DLA 598-1 for suckless-tools, fixing a segmentation fault in the slock screen locking tool.
  • Issued DLA 599-1 for cracklib2, a pro-active password checker library, fixing a stack-based buffer overflow when parsing large GECOS fields.
  • Improved the find-work internal tool adding optional colour highlighting and migrating it to Python 3.
  • Wrote an lts-missing-uploads tool to find mistakes where there was no correponding package in the archive after an announcement.
  • Added optional colour highlighting to the lts-cve-triage tool.
Uploads
  • redis 2:3.2.3-1 New upstream release, move to the DEP-5 debian/copyright format, ensure that we are running as root in LSB initscripts and add a README.Source regarding our local copies of redis.conf and sentinel.conf.
  • python-django:
    • 1:1.10-1 New upstream release.
    • 1:1.10-2 Fix test failures due to mishandled upstream translation updates.

  • gunicorn:
    • 19.6.0-2 Reload logrotate in the postrotate action to avoid processes writing to the old files and move to DEP-5 debian/copyright format.
    • 19.6.0-3 Drop our /usr/sbin/gunicorn ,3 -debian and related Debian-specific machinery to be more like upstream.
    • 19.6.0-4 Drop "template" systemd .service files and point towards examples and documentation instead.

  • adminer:
    • 4.2.5-1 Take over package maintenance, completely overhauling the packaging with a new upstream version, move to virtual-mysql-server to support MariaDB, updating package names of dependencies and fix the outdated Apache configuration.
    • 4.2.5-2 Correct the php5 package names.

FTP Team As a Debian FTP assistant I ACCEPTed 90 packages: android-platform-external-jsilver, android-platform-frameworks-data-binding, camlpdf, consolation, dfwinreg, diffoscope, django-restricted-resource, django-testproject, django-testscenarios, gitlab-ci-multi-runner, gnome-shell-extension-taskbar, golang-github-flynn-archive-go-shlex, golang-github-jamesclonk-vultr, golang-github-weppos-dnsimple-go, golang-golang-x-time, google-android-ndk-installer, haskell-expiring-cache-map, haskell-hclip, haskell-hdbc-session, haskell-microlens-ghc, haskell-names-th, haskell-persistable-record, haskell-should-not-typecheck, haskell-soap, haskell-soap-tls, haskell-th-reify-compat, haskell-with-location, haskell-wreq, kbtin, libclipboard-perl, libgtk3-simplelist-perl, libjs-jquery-selectize.js, liblemon, libplack-middleware-header-perl, libreoffice, libreswan, libtest-deep-json-perl, libtest-timer-perl, linux, linux-signed, live-tasks, llvm-toolchain-3.8, llvm-toolchain-snapshot, lua-luv, lua-torch-image, lua-torch-nn, magic-wormhole, mini-buildd, ncbi-vdb, node-ast-util, node-es6-module-transpiler, node-es6-promise, node-inline-source-map, node-number-is-nan, node-object-assign, nvidia-graphics-drivers, openhft-chronicle-bytes, openhft-chronicle-core, openhft-chronicle-network, openhft-chronicle-threads, openhft-chronicle-wire, pycodestyle, python-aptly, python-atomicwrites, python-click-log, python-django-casclient, python-git-os-job, python-hypothesis, python-nosehtmloutput, python-overpy, python-parsel, python-prov, python-py, python-schema, python-tackerclient, python-tornado, pyvo, r-cran-cairo, r-cran-mi, r-cran-rcppgsl, r-cran-sem, ruby-curses, ruby-fog-rackspace, ruby-mixlib-archive, ruby-tzinfo-data, salt-formula-swift, scapy3k, self-destructing-cookies, trollius-redis & websploit.

7 July 2016

Joey Hess: twenty years of free software -- part 10 shell-monad

shell-monad is a small project, done over a couple days and not needing many changes since, but I'm covering it separately because it was a bit of a milestone for me. As I learned Haskell, I noticed that the libraries were excellent and did things to guide their users that libraries in other languages don't do. Starting with using types and EDSLs and carefully constrained interfaces, but going well beyond that, as far as applying category theory. Using these libraries push you toward good solutions. shell-monad was a first attempt at building such a library. The shell script it generates should always be syntactically valid, and never forgets to quote a shell variable. That's only the basics. It goes further by making it impossible to typo the name of a shell variable or shell function. And it uses phantom types so that the Haskell type checker can check the types of shell variables and functions match up. So I think shell-monad is pretty neat, and I certianly learned a lot about writing Haskell libraries making it. Including how much I still have to learn! I have not used shell-monad much, but keep meaning to make propellor and git-annex use it for some of their shell script needs. And ponder porting etckeeper to generate its shell scripts using it. Next: twenty years of free software -- part 11 concurrent-output

19 May 2016

Antoine Beaupr : My free software activities, May 2016

Debian Long Term Support (LTS) This is my 6th month working on Debian LTS, started by Raphael Hertzog at Freexian. This is my largest month so far, for which I had requested 20 hours of work.

Xen work I spent the largest amount of time working on the Xen packages. We had to re-roll the patches because it turned out we originally just imported the package from Ubuntu as-is. This was a mistake because that package forked off the Debian packaging a while ago and included regressions in the packaging itself, not just security fixes. So I went ahead and rerolled the whole patchset and tested it on Koumbit's test server. Brian May then completed the uploaded, which included about 40 new patches, mostly from Ubuntu.

Frontdesk duties Next up was the frontdesk duties I had taken this week. This was mostly uneventful, although I had forgotten how to do some of the work and thus ended up doing extensive work on the contributor's documentation. This is especially important since new contributors joined the team! I also did a lot of Debian documentation work in my non-sponsored work below. The triage work involved chasing around missing DLAs, triaging away OpenJDK-6 (for which, let me remind you, security support has ended in LTS), raised the question of Mediawiki maintenance.

Other LTS work I also did a bunch of smaller stuff. Of importance, I can note that I uploaded two advisories that were pending from April: NSS and phpMyAdmin. I also reviewed the patches for the ICU update, since I built the one for squeeze (but didn't have time to upload before squeeze hit end-of-life). I have tried to contribute to the NTP security support but that was way too confusing to me, and I have left it to the package maintainer which seemed to be on top of things, even if things mean complete chaos and confusion in the world of NTP. I somehow thought that situation had improved with the recent investments in ntpsec and ntimed, but unfortunately Debian has not switched to the ntpsec codebase, so it seems that the NTP efforts have diverged in three different projects instead of closing into a single, better codebase.

Future LTS work This is likely to be my last month of work on LTS until September. I will try to contribute a few hours in June, but July and August will be very busy for me outside of Debian, so it's unlikely that I contribute much to the project during the summer. My backlog included those packages which might be of interest to other LTS contributors:
  • libxml2: no upstream fix, but needs fixing!
  • tiff ,3 : same mess
  • libgd2: maintainer contacted
  • samba regression: mailed bug #821811 to try to revive the effort
  • policykit-1: to be investigated
  • p7zip: same

Other free software work

Debian documentation I wrote an detailed short guide to Debian package development, something I felt was missing from the existing corpus, which seems to be too focus in covering all alternatives. My guide is opinionated: I believe there is a right and wrong way of doing things, or at least, there are best practices, especially when just patching packages. I ended up retroactively publishing that as a blog post - now I can simply tag an item with blog and it shows up in the blog. (Of course, because of a mis-configuration on my side, I have suffered from long delays publishing to Debian planet, so all the posts dates are off in the Planet RSS feed. This will hopefully be resolved around the time this post is published, but this allowed me to get more familiar with the Planet Venus software, as detailed in that other article.) Apart from the guide, I have also done extensive research to collate information that allowed me to create workflow graphs of the various Debian repositories, which I have published in the Debian Release section of the Debian wiki. Here is the graph: It helps me understand how packages flow between different suites and who uploads what where. This emerged after I realized I didn't really understand how "proposed updates" worked. Since we are looking at implementing a similar process for the security queue, I figured it was useful to show what changes would happen, graphically. I have also published a graph that describes the relations between different software that make up the Debian archive. The idea behind this is also to provide an overview of what happens when you upload a package in the Debian archive, but it is more aimed at Debian developers trying to figure out why things are not working as expected. The graphs were done with Graphviz, which allowed me to link to various components in the graph easily, which is neat. I also prefered Graphviz over Dia or other tools because it is easier to version and I don't have to bother (too much) about the layout and tweaking the looks. The downside is, of course, that when Graphviz makes the wrong decision, it's actually pretty hard to make it do the right thing, but there are various workarounds that I have found that made the graphs look pretty good. The source is of course available in git but I feel all this documentation (including the guide) should go in a more official document somewhere. I couldn't quite figure out where. Advice on this would be of course welcome.

Ikiwiki I have made yet another plugin for Ikiwiki, called irker, which enables wikis to send notifications to IRC channels, thanks to the simple irker bot. I had trouble with Irker in the past, since it was not quite reliable: it would disappear from channels and not return when we'd send it a notification. Unfortunately, the alternative, the KGB bot is much heavier: each repository needs a server-side, centralized configuration to operate properly. Irker's design is simpler and more adapted to a simple plugin like this. Let's hope it will work reliably enough for my needs. I have also suggested improvements to the footnotes styles, since they looked like hell in my Debian guide. It turns out this was an issue with the multimarkdown plugin that doesn't use proper semantic markup to identify footnotes. The proper fix is to enable footnotes in the default Discount plugin, which will require another, separate patch. Finally, I have done some improvements (I hope!) on the layout of this theme. I made the top header much lighter and transparent to work around an issue where followed anchors would be hidden under the top header. I have also removed the top menu made out of the sidebar plugin because it was cluttering the display too much. Those links are all on the frontpage anyways and I suspect people were not using them so much. The code is, as before, available in this git repository although you may want to start from the new ikistrap theme that is based on Bootstrap 4 and that may eventually be merged in ikiwiki directly.

DNS diagnostics Through this interesting overview of various *ping tools, I got found out about the dnsdiag tool which currently allows users to do DNS traces, tampering detection and ping over DNS. In the hope of packaging it into Debian, I have requested clarifications regarding a modification to the DNSpython library the tool uses. But I went even further and boldly opened a discussion about replacing DNSstuff, the venerable DNS diagnostic tools that is now commercial. It is somewhat surprising that there is no software that has even been publicly released that does those sanity checks for DNS, given how old DNS is. Incidentally, I have also requested smtpping to be packaged in Debian as well but httping is already packaged.

Link checking In the process of writing this article, I suddenly remembered that I constantly make mistakes in the various links I post on my site. So I started looking at a link checker, another tool that should be well established but that, surprisingly, is not quite there yet. I have found this neat software written in Python called LinkChecker. Unfortunately, it is basically broken in Debian, so I had to do a non-maintainer upload to fix that old bug. I managed to force myself to not take over maintainership of this orphaned package but I may end up doing just that if no one steps up the next time I find issues in the package. One of the problems I had checking links in my blog is that I constantly refer to sites that are hostile to bots, like the Debian bugtracker and MoinMoin wikis. So I published a patch that adds a --no-robots flag to be able to crawl those sites effectively. I know there is the W3C tool but it's written in Perl, and there's probably zero chance for me to convince those guys to bypass robots exclusion rules, so I am sticking to Linkchecker.

Other Debian packaging work At my request, Drush has finally been removed from Debian. Hopefully someone else will pick up that work, but since it basically needs to be redone from scratch, there was no sense in keeping it in the next release of Debian. Similarly, Semanticscuttle was removed from Debian as well. I have uploaded new versions of tuptime, sopel and smokeping. I have also file a Request For Help for Smokeping. I am happy to report there was a quick response and people will be stepping up to help with the maintenance of that venerable monitoring software.

Background radiation Finally, here's the generic background noise of me running around like a chicken with his head cut off: Finally, I should mention that I will be less active in the coming months, as I will be heading outside as the summer finally came! I somewhat feel uncomfortable documenting publicly my summer here, as I am more protective of my privacy than I was before on this blog. But we'll see how it goes, maybe you'll hear non-technical articles here again soon!

4 May 2016

Debian Java Packaging Team: What's new since Jessie?

Jessie was released one year ago now and the Java Team has been busy preparing the next release. Here is a quick summary of the current state of the Java packages: Outlook, goals and request for help Java and Friends Package updates The packages listed below detail the changes in jessie-backports and testing. Libraries and Debian specific tools have been excluded. Packages added to jessie-backports: Packages removed from testing: Packages added to testing: Packages upgraded in testing:

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