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STANFORD UNIVERSITY

INFORMATION TECHNOLOGY SERVICES

WebAuth 4.5.0 Announcement

The ITS WebAuth team is pleased to announce Stanford WebAuth 4.5.0. This is a major new feature release, particularly for multifactor support in the WebKDC and WebLogin components.

There is one significant backward-incompatible change in WebLogin that will require either a template or a configuration change when upgrading. WebLogin now allows the user to indicate that they do not want single sign-on cookies stored on their current device. Following the typical user interface of most web sites with this capability, the default way of supporting this is with a checkbox indicating whether to "remember my login on this device." We expect most sites to want this phrasing (since it is what users expect), but possibly with the checkbox checked by default so that the default matches current behavior.

However, due to the way that HTML forms handle checkboxes, the default behavior of the code needs to be the opposite of what the checkbox indicates. Therefore, the new version of WebLogin, if deployed without any changes, will stop setting single sign-on cookies.

During upgrade, sites will want to either add a checkbox to their login page (probably checked by default) saying to create single sign-on cookies, similar to:

    <input type="checkbox" name="remember_login" value="yes"
           checked="checked">

or, if no UI changes are desired, add:

    $REMEMBER_FALLBACK = 'yes';

to /etc/webkdc/webkdc.conf to change the default behavior to be to create single sign-on cookies. This setting is also appropriate if the user interface should have the opposite sense (in other words, a checkbox indicating single sign-on cookies should not be created).

Users of WebAuthForceLogin should be aware that, after further consideration, the behavior has been reverted to the behavior prior to 4.4.0, backing out the behavior change in 4.4.0.

For documentation and downloads of WebAuth 4.5.0, see:

<http://webauth.stanford.edu/>

New Debian packages built against Apache 2.4 have been uploaded to Debian experimental.

Thanks to Benjamin Coddington and William Orr for their contributions to this release.

The user-visible changes in this release are:

  • The change in interpretation of WebAuthForceLogin introduced in 4.4.0 has been reverted, and WebAuthForceLogin once again requires that the user perform an authentication that results in a login token (either password or OTP). This seems more generally useful than making this directive largely redundant with WebAuthRequireSessionFactor. Add a caution in the documentation explaining that this will not work well with authorization identities in most environments.

  • WebLogin now supports login form templates that allow the user (or the template) to indicate whether single sign-on cookies (and any persistent factor cookies) should be retained after authentication. The fallback, if the HTML form doesn't send a value, is controlled by the new $REMEMBER_FALLBACK configuration option. The default is to not do single sign-on, but the default login template sets the form parameter to enable single sign-on. This will require template updates when upgrading. If configured not to set single sign-on cookies, WebLogin will only retain single sign-on cookies and persistent factor cookies long enough to complete the login process and will then discard them, reducing the risk of theft of authentication tokens when someone walks away from an untrusted computer.

  • Fix password change handling in WebLogin, which has been broken since 4.4.0 due to code changes for handling account lockout. Also fix reporting of the reason for a rejected password change, which has been broken since WebAuth 4.3.0.

  • Apache 2.4 error logging has been fixed for all modules to properly indicate the module name originating the message.

  • mod_webauth and mod_webkdc will now produce significantly better Apache error log messages with more context and details about the failure.

  • Initial multifactor no longer satisfies a random session multifactor requirement, correcting a long-standing bug in random multifactor handling.

  • mod_webauthldap supports a new WebAuthLdapOperationalAttribute directive that is the same as WebAuthLdapAttribute but searches the directory for operational attributes and adds them to the environment. Patch from William Orr.

  • WebLogin no longer supports obtaining the password expiration from a kadmin-remctl backend with a direct remctl call. Instead, it uses the password expiration time returned by the WebKDC, which in turn gets it from the user information service.

  • A new WebAuth confirmation page template variable is available, expire_timestamp, which includes the timestamp (in seconds since UNIX epoch) when the password will expire. This should be used instead of the old (and now deprecated) expire_date variable since it allows the time information to be localized. See the example confirm.tmpl file to see how to format this using Perl's Time::Duration module.

  • The WebKDC and WebLogin now support persistent cookies that add additional authentication factors to a successful authentication. This can be used to require multifactor authentication only from browsers that have not previously completed a multifactor authentication (similar to "remember this device" in various web services). The additional factors are stored in a new webkdc-factor token type and a new webauth_wft cookie. A persistent factor cookie is created when the user information service validation call for an OTP authentication returns a list of persistent factors. The validation service can indicate the lifetime of the cookie. The cookies will be re-encrypted in the current WebKDC private key on each interaction with WebLogin to prevent them from becoming invalid due to key rotation (although this does mean that they will become invalid over long periods of inactivity).

  • The user information service can invalidate all persistent factor tokens created before a particular timestamp by including an <valid-threshold> element in the userinfo reply.

  • WebLogin supports optionally warning the user when persistent factor tokens are about to expire. See the generic confirmation page template for an example of how to do this. The warning threshold can be configured in /etc/webkdc/webkdc.conf.

  • When the WebKDC calls the user information service, it now provides, as an additional parameter, the current initial authentication factors for the user. This can be used by the user information service to decide whether or not to require a multifactor authentication. This is most useful in combination with persistent factors; for example, the user information service can require multifactor authentication if the user didn't present a persistent factor token for the "d" (device) factor, indicating that device had previously authenticated with multifactor.

  • In addition to requiring a multifactor authentication, the user information service can now add a specific list of factors that will be required for this authentication. The user will be required to provide the union of this list and the list of factors requested by the WebAuth Application Server. Contributed by Benjamin Coddington.

  • The user information service can return a message to WebLogin for display in the multifactor authentication page. One possible use is for the user information service to tell the user why a multifactor authentication is required. Contributed by Benjamin Coddington.

  • The user information service (with both the userinfo and validate calls) can return an opaque login state string, which is passed to WebLogin and from there to the multifactor login template. The template can set the login state as a form variable and pass it back to the user information service validate function. This allows for multistep multifactor authentication using serialized data, allowing implementation of (for example) resynchronization of a hardware token. Contributed by Benjamin Coddington.

  • The user information service can now add factors to the user's authentication if the user successfully completed an interactive authentication (defined as one that involved WebLogin sending a login token, which in practice means an OTP or password authentication). The new "h" (human verification) factor has been added to the factor list for this purpose and counts as an additional factor for the purposes of satisfying multifactor. The intended use of this feature is to allow a local support desk to verify someone's identity out of band and then bless their authentications for a certain length of time as satisfying multifactor even if they've forgotten their second factor.

  • WebLogin and the multifactor authentication template now receive a list of which factors the user must provide but has not already provided, rather than a complete list of required factors. This is used to provide a better value for the factor_type template parameter for the multifactor login template. Contributed by Benjamin Coddington.

  • WebLogin can now tell the WebKDC what type of OTP was used for a multifactor authentication, if it knows, and the WebKDC will pass that information to the user information service validate call. Contributed by Benjamin Coddington.

  • The user information service can now indicate the expiration time of a webkdc-proxy token created via an OTP authentication by including an <expiration> element in its reply.

  • Errors contacting the user information service are now logged to the Apache error log by mod_webkdc even if it is configured to ignore those errors and continue as if no user information service is availabe.

  • webauth_factors is now a private data structure with a much richer C API for manipulating sets of factors. Several other internal APIs, particularly the ones related to the WebKDC login process or the user information service, take opaque webauth_factors structs instead of APR lists of factors.

  • mod_webkdc no longer supports obtaining proxy tokens with <getTokenRequest>. This was never used by WebAuth code and is conceptually useless.

  • The WebKDC login API now expects encrypted token strings rather than decrypted token structs as input and returns the error code, whether a protocol error or an internal error, rather than using a separate field in the response struct.

  • Diagnose undef arguments to various Perl WebAuth module functions implemented in XS and throw exceptions rather than segfaulting from a NULL pointer dereference.

  • Fix compilation error with Heimdal Kerberos libraries, introduced in WebAuth 4.4.0.

  • Update to C TAP Harness 2.1:

    • runtests now treats the command line as a list of tests by default.
    • The full test executable path can now be passed to runtests -o.
    • Improved harness output for tests with lazy plans.
    • Improved harness output to a terminal for some abort cases.
    • Flush harness output after each test even when not on a terminal.
Last modified Friday, 12-Dec-2014 02:31:13 PM

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