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Here's a summary from the Docker perspective https://blog.docker.com/2016/04/docker-security/ https://blog.docker.com/2016/04/docker-security/

jsmthrowaway 10y ago
The table from the report and Docker's championing thereof are also (nearly flagrantly) misleading, since Docker only supports image signing if you use the public hub. You cannot (repeat: cannot) sign Docker containers any other way, so it's barely a half feature and does not work for enterprises at all. But it says "strong defaults" in their table when describing this oddly useless feature, since enterprises are the ones most likely to invest in a serious key infrastructure and actually use signing: https://docs.docker.com/engine/security/trust/content_trust/ https://docs.docker.com/engine/security/trust/content_trust/ > Content trust is currently only available for users of the public Docker Hub. It is currently not available for the Docker Trusted Registry or for private registries. > Currently, content trust is disabled by default. You must enable it by setting the DOCKER_CONTENT_TRUST environment variable. How is the complete lack of image verification until explicitly enabled, and only on public images, a "strong default"? I'm also mystified by the row for SELinux, where rkt has Optional in scary yellow for some reason, and the other two do not. I suspect that table was the whole point of the independent review and it is fulfilling its purpose handily for Docker. I haven't even read the report and I can identify four suspicious discrepancies in that table alone. ETA: Compare how the author describes Docker to rkt (it's rkt, not Rkt, too): http://imgur.com/a/D6nEw http://imgur.com/a/D6nEw
- dyn 10y ago
  Hi, author of paper here. Couple things: - I agree the requirement of using Docker hub or their private hub is an unfortunate requirement, but I'm talking purely about the technical implementation. "Does not work for enterprises at all", well, there are a number of large enterprises that would disagree with you ;) - For the table w/ SELinux row, Rkt is optional "scary" yellow because it only supports a single MAC implementation, it isn't very portable, and it's not enabled by default, vs LXC and Docker which both have quite strong MAC policies by default. Trying to parse all the info down into a table was honestly quite difficult (balancing being able to read it without a million footnotes for each point). Hopefully readers don't take all their take-aways from the table, and read the paper in full. - I used Rkt for the name and rkt for the command. Seemed to help consistency. Thanks for your feedback.
  - mjg59 10y ago
    (Disclaimer: I added SELinux support to CoreOS) I'm a little confused around the SELinux issue. SELinux is inherently unportable - each distribution has its own policy (generally based on refpolicy, but sometimes fairly divergent), and it's basically impossible for an application to ship a policy that's compatible with more than one distribution. Rkt's SELinux design inherits from SVirt in such a way that in most cases it'll just work with a distribution's existing SELinux policy. It's fair to say that the number of distributions that ship policy that works with Docker is larger than for rkt, but this is fundamentally about distribution priorities rather than technological choices. On Fedora, rkt should provide identical SELinux confinement to Docker - on CoreOS it'll be better, since we support SELinux on overlayfs as well. Whether SELinux is enabled or not is (again) a distribution choice. Fedora ship with SELinux enabled by default, and both rkt and Docker will use it as a result.
  - jsmthrowaway 10y ago
    Thanks for responding. I'm talking about the technical implementation, too. How is a feature hidden behind an environment variable a "strong default?" And Docker simply screenshot the table, so noble goal, but... I suppose I could remark upon MESOS, Rkt, and so on, and how getting names right is important because it characterizes the rest of your thoughts and analysis of the things you're studying, but I'll stick with the question I started with here.
- bigmac 10y ago
  You cannot (repeat: cannot) sign Docker containers any other way, so it's barely a half feature and does not work for enterprises at all. What makes you think this? It is 100%, patently false. Private notary servers can be deployed alongside private registry servers without problem. See here for docs on how to do it: https://github.com/docker/notary/blob/master/docs/running_a_service.md https://github.com/docker/notary/blob/master/docs/running_a_...
  - jsmthrowaway 10y ago
    > What makes you think this? The docs I linked and quoted, written by your own organization and helpfully pasted into the point I made? I'm glad to see it's possible (if cumbersome), but I ruled Docker out for this purpose based on the exact link I just pasted. I also followed up and didn't see a "hey, you can sign private registries" bullet in your blog post responding to this paper, or much of anywhere, and Googling "docker sign private registries" doesn't go anywhere. I'm still unsure why I'd stand up several daemons to accomplish signing a file, but that's a side point. ---- ETA: I can no longer reply because I've burned my precious HN comment budget commenting upon this paper (sorry, blame HN), so here's what I would reply to you downthread: > 1. We have to host the signatures somewhere, so we host them in a store we call the notary server. We've had this solved for a long time with .asc files, and Docker is already shipping an HTTP server or six. Shit, extend the Docker format and put the signature on each layer. There's a lot of prior art from RPM and dpkg in particular on how this can be done without writing yet another Docker daemon to run. I'm sorry, I have to call bullshit, here. Docker is a very strong daemon-for-everything engineering culture, and that's the only reason it exists. It's also why folks are competing with you, because there are three or four different daemons in the Docker ecosystem that simply should not exist. Including dockerd. > Think serving an outdated container with known-vulnerable software. Sadly, most artifact signing systems do not mitigate this attack today, Because it's out of scope of a signature. That is conflating a signature with content revocation, which is a different problem altogether. A signature is an attestation of certain properties of data, and "is no longer valid content because circumstances changed after it was signed" is not one of them. The validity of the content is orthogonal to its signature. That known-vulnerable container is still a valid signature, and it's overreaching to expect a signature system to solve that problem. That is solvable in other ways. Known-bad OpenSSL is still signed in repositories. And valid. And that's fine, because it's a separation of concerns; you get non-repudiation, integrity, all that stuff from a signature scheme. Upgrading to gatekeeping content on top of signatures indicates to me a fundamental misunderstanding of the problem ("can I run this?" instead of "this is an authenticated, intact image that came from where I expect"), which concerns me. You can solve the problem you present in other ways. Mixing in the term "replay attack" is extremely confusing and I think diluting your point, because it is baffling me and really does not apply to what you are saying.

jsmthrowaway 10y ago

The table from the report and Docker's championing thereof are also (nearly flagrantly) misleading, since Docker only supports image signing if you use the public hub. You cannot (repeat: cannot) sign Docker containers any other way, so it's barely a half feature and does not work for enterprises at all. But it says "strong defaults" in their table when describing this oddly useless feature, since enterprises are the ones most likely to invest in a serious key infrastructure and actually use signing: https://docs.docker.com/engine/security/trust/content_trust/ https://docs.docker.com/engine/security/trust/content_trust/ > Content trust is currently only available for users of the public Docker Hub. It is currently not available for the Docker Trusted Registry or for private registries. > Currently, content trust is disabled by default. You must enable it by setting the DOCKER_CONTENT_TRUST environment variable. How is the complete lack of image verification until explicitly enabled, and only on public images, a "strong default"? I'm also mystified by the row for SELinux, where rkt has Optional in scary yellow for some reason, and the other two do not. I suspect that table was the whole point of the independent review and it is fulfilling its purpose handily for Docker. I haven't even read the report and I can identify four suspicious discrepancies in that table alone. ETA: Compare how the author describes Docker to rkt (it's rkt, not Rkt, too): http://imgur.com/a/D6nEw http://imgur.com/a/D6nEw

dyn 10y ago
Hi, author of paper here. Couple things: - I agree the requirement of using Docker hub or their private hub is an unfortunate requirement, but I'm talking purely about the technical implementation. "Does not work for enterprises at all", well, there are a number of large enterprises that would disagree with you ;) - For the table w/ SELinux row, Rkt is optional "scary" yellow because it only supports a single MAC implementation, it isn't very portable, and it's not enabled by default, vs LXC and Docker which both have quite strong MAC policies by default. Trying to parse all the info down into a table was honestly quite difficult (balancing being able to read it without a million footnotes for each point). Hopefully readers don't take all their take-aways from the table, and read the paper in full. - I used Rkt for the name and rkt for the command. Seemed to help consistency. Thanks for your feedback.
- mjg59 10y ago
  (Disclaimer: I added SELinux support to CoreOS) I'm a little confused around the SELinux issue. SELinux is inherently unportable - each distribution has its own policy (generally based on refpolicy, but sometimes fairly divergent), and it's basically impossible for an application to ship a policy that's compatible with more than one distribution. Rkt's SELinux design inherits from SVirt in such a way that in most cases it'll just work with a distribution's existing SELinux policy. It's fair to say that the number of distributions that ship policy that works with Docker is larger than for rkt, but this is fundamentally about distribution priorities rather than technological choices. On Fedora, rkt should provide identical SELinux confinement to Docker - on CoreOS it'll be better, since we support SELinux on overlayfs as well. Whether SELinux is enabled or not is (again) a distribution choice. Fedora ship with SELinux enabled by default, and both rkt and Docker will use it as a result.
- jsmthrowaway 10y ago
  Thanks for responding. I'm talking about the technical implementation, too. How is a feature hidden behind an environment variable a "strong default?" And Docker simply screenshot the table, so noble goal, but... I suppose I could remark upon MESOS, Rkt, and so on, and how getting names right is important because it characterizes the rest of your thoughts and analysis of the things you're studying, but I'll stick with the question I started with here.
bigmac 10y ago
You cannot (repeat: cannot) sign Docker containers any other way, so it's barely a half feature and does not work for enterprises at all. What makes you think this? It is 100%, patently false. Private notary servers can be deployed alongside private registry servers without problem. See here for docs on how to do it: https://github.com/docker/notary/blob/master/docs/running_a_service.md https://github.com/docker/notary/blob/master/docs/running_a_...
- jsmthrowaway 10y ago
  > What makes you think this? The docs I linked and quoted, written by your own organization and helpfully pasted into the point I made? I'm glad to see it's possible (if cumbersome), but I ruled Docker out for this purpose based on the exact link I just pasted. I also followed up and didn't see a "hey, you can sign private registries" bullet in your blog post responding to this paper, or much of anywhere, and Googling "docker sign private registries" doesn't go anywhere. I'm still unsure why I'd stand up several daemons to accomplish signing a file, but that's a side point. ---- ETA: I can no longer reply because I've burned my precious HN comment budget commenting upon this paper (sorry, blame HN), so here's what I would reply to you downthread: > 1. We have to host the signatures somewhere, so we host them in a store we call the notary server. We've had this solved for a long time with .asc files, and Docker is already shipping an HTTP server or six. Shit, extend the Docker format and put the signature on each layer. There's a lot of prior art from RPM and dpkg in particular on how this can be done without writing yet another Docker daemon to run. I'm sorry, I have to call bullshit, here. Docker is a very strong daemon-for-everything engineering culture, and that's the only reason it exists. It's also why folks are competing with you, because there are three or four different daemons in the Docker ecosystem that simply should not exist. Including dockerd. > Think serving an outdated container with known-vulnerable software. Sadly, most artifact signing systems do not mitigate this attack today, Because it's out of scope of a signature. That is conflating a signature with content revocation, which is a different problem altogether. A signature is an attestation of certain properties of data, and "is no longer valid content because circumstances changed after it was signed" is not one of them. The validity of the content is orthogonal to its signature. That known-vulnerable container is still a valid signature, and it's overreaching to expect a signature system to solve that problem. That is solvable in other ways. Known-bad OpenSSL is still signed in repositories. And valid. And that's fine, because it's a separation of concerns; you get non-repudiation, integrity, all that stuff from a signature scheme. Upgrading to gatekeeping content on top of signatures indicates to me a fundamental misunderstanding of the problem ("can I run this?" instead of "this is an authenticated, intact image that came from where I expect"), which concerns me. You can solve the problem you present in other ways. Mixing in the term "replay attack" is extremely confusing and I think diluting your point, because it is baffling me and really does not apply to what you are saying.