Gitiles
Code Review Sign In
gerrit.openbmc.org / openbmc / bmcweb / 636be396e4f3ecc09e446ca76db380fc0c5b57f9
commit636be396e4f3ecc09e446ca76db380fc0c5b57f9[log] [tgz]
authorGunnar Mills <gmills@us.ibm.com>Mon Mar 15 12:47:07 2021 -0500
committerEd Tanous <ed@tanous.net>Thu Mar 18 22:00:03 2021 +0000
tree2791df9c2adb3f91c2a9904bdfb801e77b8dead8
parentfbcc252da12a6e614588426d5e61f0b1948859b4 [diff]
Add SameSite=Strict on Set-Cookie

Set SameSite to Strict since OpenBMC does not have functionality
that requires Lax or None.

SameSite Strict provides a little protection against CSRF attacks
by ensuring the cookie is only sent to requests originating from
the same site that set the cookie.

This came from some discussion on discord.

From https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie

SameSite=<samesite-value> Optional
  Controls whether a cookie is sent with cross-origin requests,
providing some protection against cross-site request forgery attacks

Inline options are:

  Strict: The browser sends the cookie only for same-site requests
(that is, requests originating from the same site that set the
cookie). If the request originated from a different URL than the
current one, no cookies with the SameSite=Strict attribute are sent.

  Lax: The cookie is not sent on cross-site requests, such as calls
to load images or frames, but is sent when a user is navigating to
the origin site from an external site (e.g. if following a link).
  This is the default behavior if the SameSite attribute is not
specified.

  None: The browser sends the cookie with both cross-site and
same-site requests. The Secure attribute must also be set when
SameSite=None!

Note: On Firefox 85, FireFox still doesn't have the Default set
to SameSite=Lax. This can be changed via "about:config" and
"network.cookie.sameSite.laxByDefault".

Tested: Webui-vue works. Redfish GUI browser works.
        Websockets work on the GUI.
        Tested GUI functions that call POST and PATCH.
        Can see the XSRF-TOKEN and SESSION cookies are SameSite
        Strict with this build. Before were SameSite None.
        Browser DevTools -> Storage on Firefox to view cookies.
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>

Change-Id: I4402f2930847c1d47b22696631be26d33c78b6f9
2 files changed
tree: 2791df9c2adb3f91c2a9904bdfb801e77b8dead8
  1. .github/
  2. http/
  3. include/
  4. redfish-core/
  5. scripts/
  6. src/
  7. static/
  8. subprojects/
  9. .clang-format
  10. .clang-ignore
  11. .clang-tidy
  12. .dockerignore
  13. .gitignore
  14. .shellcheck
  15. bmcweb.service.in
  16. bmcweb.socket
  17. bmcweb_config.h.in
  18. build_x86.sh
  19. build_x86_docker.sh
  20. COMMON_ERRORS.md
  21. DEVELOPING.md
  22. Dockerfile
  23. Dockerfile.base
  24. LICENCE
  25. MAINTAINERS
  26. meson.build
  27. meson_options.txt
  28. OEM_SCHEMAS.md
  29. OWNERS
  30. pam-webserver
  31. README.md
  32. Redfish.md
README.md

OpenBMC webserver

This component attempts to be a "do everything" embedded webserver for openbmc.

Capabilities

At this time, the webserver implements a few interfaces:

  • Authentication middleware that supports cookie and token based authentication, as well as CSRF prevention backed by linux PAM authentication credentials.
  • An (incomplete) attempt at replicating phosphor-dbus-rest interfaces in C++. Right now, a few of the endpoint definitions work as expected, but there is still a lot of work to be done. The portions of the interface that are functional are designed to work correctly for phosphor-webui, but may not yet be complete.
  • Replication of the rest-dbus backend interfaces to allow bmc debug to logged in users.
  • An initial attempt at a read-only redfish interface. Currently the redfish interface targets ServiceRoot, SessionService, AccountService, Roles, and ManagersService. Some functionality here has been shimmed to make development possible. For example, there exists only a single user role.
  • SSL key generation at runtime. See the configuration section for details.
  • Static file hosting. Currently, static files are hosted from the fixed location at /usr/share/www. This is intended to allow loose coupling with yocto projects, and allow overriding static files at build time.
  • Dbus-monitor over websocket. A generic endpoint that allows UIs to open a websocket and register for notification of events to avoid polling in single page applications. (this interface may be modified in the future due to security concerns.

Configuration

BMCWeb is configured by setting -D flags that correspond to options in bmcweb/meson_options.txt and then compiling. For example, meson <builddir> -Dkvm=disabled ... followed by ninja in build directory. The option names become C++ preprocessor symbols that control which code is compiled into the program.

Compile bmcweb with default options:

meson builddir
ninja -C builddir

Compile bmcweb with yocto defaults:

meson builddir -Dbuildtype=minsize -Db_lto=true -Dtests=disabled
ninja -C buildir

If any of the dependencies are not found on the host system during configuration, meson automatically gets them via its wrap dependencies mentioned in bmcweb/subprojects.

Enable/Disable meson wrap feature

meson builddir -Dwrap_mode=nofallback
ninja -C builddir

Generate test coverage report:

meson builddir -Db_coverage=true -Dtests=enabled
ninja coverage -C builddir test

When BMCWeb starts running, it reads persistent configuration data (such as UUID and session data) from a local file. If this is not usable, it generates a new configuration.

When BMCWeb SSL support is enabled and a usable certificate is not found, it will generate a self-sign a certificate before launching the server. The keys are generated by the secp384r1 algorithm. The certificate

  • is issued by C=US, O=OpenBMC, CN=testhost,
  • is valid for 10 years,
  • has a random serial number, and
  • is signed using the SHA-256 algorithm.