AUTOLOGIN(8)						     DACS Web Services Manual						      AUTOLOGIN(8)

NAME

       autologin - Convert an Apache identity to a DACS identity

SYNOPSIS

       autologin [dacsoptions[1]]

DESCRIPTION

       This program is part of the DACS suite.

       The autologin CGI program, in conjunction with appropriate Apache and DACS configuration, is used to automatically convert an identity
       already established by Apache into a DACS identity. After standard HTTP Basic or Digest Authentication (RFC 2617[2]) has been performed
       successfully, autologin causes DACS credentials to be generated and returned. This capability lets DACS leverage any of Apache's existing
       authentication methods through simple configuration.

       A user that has completed Basic or Digest Authentication (following a 401 Authorization Required response from the web server) accesses
       autologin.  autologin generates credentials by constructing a request to dacs_authenticate(8)[3]. The value of the REMOTE_USER environment
       variable, as set by Apache, is used by dacs_authenticate to derive the DACS username.

	   Note
	   autologin is not installed by default when DACS is built, in part because it can be a bit tricky to configure correctly and securely.
	   The more recent RFC 2617[2] capability built-in to DACS is recommended instead. Please refer to the section on HTTP Authentication[4].

	   Security
	   Because this program is run during authentication processing, its file permissions must be set to prevent replacement or alteration by
	   users other than a DACS administrator.

OPTIONS

       Only the standard dacsoptions[1] command line arguments are recognized.

   Web Service Arguments
       autologin understands the following CGI arguments. All arguments are required unless otherwise indicated.

       DACS_CONF
	   The path to the DACS configuration file that should be used to locate jurisdiction configuration information needed by
	   dacs_authenticate.

       DACS_ERROR_URL
	   When autologin is invoked as a result of DACS event handling, DACS_ERROR_URL is automatically passed by dacs_acs(8)[5] and represents
	   the original URL to which access was denied. In typical use, autologin is configured as the handler for a dacs_acs 902 error code
	   (NO_AUTH, "Authentication by DACS is required").  autologin then invokes dacs_authenticate. If DACS authentication is successful,
	   dacs_authenticate ordinarily issues a browser redirect to the value of DACS_ERROR_URL and a cookie bearing the credentials are set in
	   the browser (but see the NOREDIRECT argument).

       NOREDIRECT
	   If this optional argument is present (its value is immaterial), autologin instructs dacs_authenticate to not issue a browser redirect
	   to the value of DACS_ERROR_URL.

       DACS_JURISDICTION
	   When autologin is invoked as a result of DACS event handling, DACS_JURISDICTION is set by DACS to the name of the jurisdiction that
	   received the request. By default, autologin generates credentials for the jurisdiction at which dacs_authenticate is invoked
	   (specifically, DACS_JURISDICTION). This can be overridden by the DACS_SET_JURISDICTION parameter.

       DACS_SET_JURISDICTION
	   This optional argument explicitly names the jurisdiction in which autologin should generate credentials.  DACS_SET_JURISDICTION
	   overrides the value, if any, of DACS_JURISDICTION and must be the same as the jurisdiction in which autologin is deployed.

       JURISDICTION_URI
	   This is the URI identifying the jurisdiction in the DACS configuration file corresponding to the value specified in a DACS_JURISDICTION
	   or DACS_SET_JURISDICTION argument. This argument is optional since the jurisdiction name can be used for this purpose.

       just_dump_stdin
	   This optional argument is useful for debugging. If the value of QUERY_STRING is exactly jump_dump_stdin, then the program will simply
	   copy its standard input to the standard output as text/plain.

EXAMPLE

       A typical use of autologin is to support coexistence on the same Web site of DACS-wrapped content, services. legacy applications, or
       content deployed under HTTP Basic or Digest authentication. The following example illustrates configuration of Apache and DACS for the
       deployment under HTTP Basic authentication of a Web log application, Blogo.  Blogo will be deployed within a DACS jurisdiction METALOGIC.
       The URI space of interest will be example.com/metalogic/*.

       In the Apache configuration file httpd.conf, a Location is defined for the Blogo application under Basic authentication:

	   <Location /metalogic/blogo>
	     AuthType Basic
	     AuthName "FedDev"
	     AuthUserFile /local/etc/auth-file
	     Require valid-user
	   </Location>

       A Location under Basic authentication also is defined where the autologin utility is deployed:

	   <Location /metalogic/dacs-native>
	     AuthType Basic
	     AuthName "FedDev"
	     AuthUserFile /local/etc/auth-file
	     Require valid-user
	   </Location>

       At the same time, other content in METALOGIC is protected by DACS:

	   <Location /metalogic/dev>
	     Allow from all
	     AuthType DACS
	     AuthDACS dacs-acs
	     Require valid-user
	   </Location>

	   Note
	   Basic authentication cannot be specified in a subdirectory of a directory or location that has been configured for DACS access control.
	   As above, DACS and Basic authentication must be configured in separate locations.

       In the DACS configuration file, dacs.conf, jurisdiction METALOGIC is configured as follows:

	   <Jurisdiction uri="example.com/metalogic">

	   JURISDICTION_NAME "METALOGIC"

	   ACS_ERROR_HANDLER "902 https://example.com/metalogic/dacs-native/autologin
	   ?DACS_CONF=${Conf::DACS_CONF}&amp;JURISDICTION_URI=example.com/metalogic"

	   <!-- Authenticate using Apache Basic/Digest Auth. -->
	   <Auth id="native">
	   URL "https://example.com/metalogic/dacs/local_native_authenticate"
	   STYLE "native"
	   CONTROL "sufficient"
	   </Auth>

	   </Jurisdiction>

	   Note
	   The native style of authentication must be configured when autologin is being used as described. See dacs_authenticate(8)[6].

       The preceding configuration results in the following behaviour. A user accessing Blogo directly (https://example.com/metalogic/blogo) is
       challenged to enter a valid username and password (with respect to the Apache accounts in /local/etc/auth-file). If the user subsequently
       accesses DACS content requiring DACS authentication but no DACS credentials are present:

       o   The 902 event handler is invoked, resulting in a browser redirect to autologin.

       o   The REMOTE_USER environment variable is present in the environment as a result of successful Basic authentication.

       o   autologin runs dacs_authenticate (as a command, not as a web service).

       o   dacs_authenticate then invokes local_native_authenticate, which uses the value of REMOTE_USER as the USERNAME argument.

       o   If authentication succeeds, DACS credentials for REMOTE_USER in jurisdiction METALOGIC are generated. These credentials are returned to
	   the browser within a cookie and the browser is redirected to the value of DACS_ERROR_URL (recall that DACS_ERROR_URL was passed to
	   autologin by dacs_acs when the 902 handler was invoked and is forwarded to dacs_authenticate).

       If the user accesses DACS content without first visiting the Blogo application, the 902 event handler fires, resulting in a browser
       redirect to autologin. Since autologin is itself behind Basic authentication, the user will be prompted for a username and password. Once
       Basic authentication succeeds, autologin is invoked with REMOTE_USER set (and therefore so is dacs_authenticate) and the process described
       above is repeated.

       autologin may also be used as the target of an explicit authentication link. For example:

	   <a href="https://example.com/metalogic/dacs-native/autologin?
	   DACS_CONF=/local/dacs/federations/example.com/dacs.conf&
	   DACS_SET_JURISDICTION=METALOGIC&
	   JURISDICTION_URI=example.com/metalogic&
	   DACS_ERROR_URL=https://example.com">Login</a>

       Following the link above results first in a Basic authentication challenge and then sets DACS credentials in jurisdiction METALOGIC.

NOTES

       autologin cannot generate credentials in a jurisdiction other than the one in which autologin is deployed.

       The behaviour of browsers with respect to the HTTP 401 Authorization status code may have undesired consequences. For example, browsers
       continually send username and password in any matching request. If a user does not exit the browser, this can result in DACS credentials
       automatically being regenerated long after their configured lifetime has expired.  RFC 2617[2] provides no way for the server to "signout"
       a user, and neither do many browsers (Firefox[7] is an exception), other than by ending the browser session. This makes it inconvenient for
       a user to reauthenticate with respect to DACS using this technique.

DIAGNOSTICS

       The program exits 0 if everything was fine, 1 if an error occurred.

SEE ALSO

       dacs_authenticate(8)[3] (in particular, the native authentication style), dacs_autologin_ssl(8)[8], dacs_acs(8)[5], dacs.conf(5)[9]

AUTHOR

       Metalogic Software Corp.[10] and Distributed Systems Software (www.dss.ca[11])

COPYING

       Copyright2003-2012 Distributed Systems Software. See the LICENSE[12] file that accompanies the distribution for licensing information.

NOTES

	1. dacsoptions
	   http://dacs.dss.ca/man/dacs.1.html#dacsoptions

	2. RFC 2617
	   http://www.rfc-editor.org/rfc/rfc2617.txt

	3. dacs_authenticate(8)
	   http://dacs.dss.ca/man/dacs_authenticate.8.html

	4. HTTP Authentication
	   http://dacs.dss.ca/man/dacs_acs.8.html#http_authentication

	5. dacs_acs(8)
	   http://dacs.dss.ca/man/dacs_acs.8.html

	6. dacs_authenticate(8)
	   http://dacs.dss.ca/man/dacs_authenticate.8.html#local_native_authenticate

	7. Firefox
	   http://www.mozilla.com/firefox

	8. dacs_autologin_ssl(8)
	   http://dacs.dss.ca/man/dacs_autologin_ssl.8.html

	9. dacs.conf(5)
	   http://dacs.dss.ca/man/dacs.conf.5.html

       10. Metalogic Software Corp.
	   http://fedroot.com/admin/about-metalogic.shtml

       11. www.dss.ca
	   http://www.dss.ca

       12. LICENSE
	   http://dacs.dss.ca/man/../misc/LICENSE

DACS 1.4.27b							    10/22/2012							      AUTOLOGIN(8)