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gerrit.openbmc.org / openbmc / bmcweb / 51dae67d0069281593a76e4ceb5f8ede1bc4abdc
commit51dae67d0069281593a76e4ceb5f8ede1bc4abdc[log] [tgz]
authorEd Tanous <ed.tanous@intel.com>Wed Sep 05 16:07:32 2018 -0700
committerJames Feist <james.feist@linux.intel.com>Mon Nov 18 21:27:43 2019 +0000
tree1c731844a72da20749d609503e616d52560b8910
parentd500549b209761e46791458b49ce2fee5c8b682b [diff]
Implement constant time string compare for token

The sessions implementation previously used operator== for session
comparisons.  While unlikely to be attackable in the current
implementation, due to the time smearing in a number of cases, modern
security practices recommend using constant time comparison.

Tested By:
Logged into the webui, and observed no change to login flows.  Logged
into redfish using Token Auth, and observed no changes.  Closed a
previous session, then reopened with the new session information to
verify user sessions are restored properly and still work.

Change-Id: Ie759e4da67ba004fd8c327f177951ac756ea6799
Signed-off-by: Ed Tanous <ed.tanous@intel.com>
Signed-off-by: James Feist <james.feist@linux.intel.com>
3 files changed
tree: 1c731844a72da20749d609503e616d52560b8910
  1. cmake/
  2. http/
  3. include/
  4. redfish-core/
  5. scripts/
  6. src/
  7. static/
  8. .clang-format
  9. .gitignore
  10. bmcweb.service.in
  11. bmcweb.socket
  12. build_x86.sh
  13. cmake-format.json
  14. CMakeLists.txt
  15. CMakeLists.txt.in
  16. DEVELOPING.md
  17. JenkinsFile
  18. LICENCE
  19. MAINTAINERS
  20. pam-webserver
  21. README.md
  22. 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/CMakeLists.txt and then compiling. For example, cmake -DBMCWEB_ENABLE_KVM=NO ... followed by make. The option names become C++ preprocessor symbols that control which code is compiled into the program.

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 prime256v1 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.