From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Wed, 20 Mar 2013 18:29:33 +0000 (+0000)
Subject: docs: more work
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=cgi-auth-flexible.git;a=commitdiff_plain;h=1a701618a0a38468ed193dd5fbb0f275994bb1f4;ds=sidebyside

docs: more work
---

diff --git a/caf.pod b/caf.pod
index ef64982..ba5300c 100644
--- a/caf.pod
+++ b/caf.pod
@@ -68,7 +68,13 @@ honour the return value.
 =item *
 
 If you're using C<check_ok>, implement either the
-C<username_password_error> or C<login_ok> hook.
+C<username_password_error> or C<login_ok> hook and provide it as
+a setting to C<new_verifier>.
+
+=item *
+
+Provide the setting C<dir> (or provide absolute paths for all the
+other relevant settings).
 
 =item *
 
@@ -111,6 +117,8 @@ The resulting verifier object can be used to process individual
 requests, in each case with
 C<< $authreq = CGI::Auth::Flexible->new_request($cgi_query) >>.
 
+See L</SETTINGS>.
+
 =head2 CHECKING AND RESPONSE GENERATION
 
 If the user is logged in, your application is to handle the request.
@@ -503,6 +511,180 @@ digits.
 
 =back
 
+=head1 SETTINGS
+
+C<new_verifier> and C<new_request> each take a list of settings, as
+a list of pairs C<< key => value >> (like a Perl hash assignment).
+
+The settings supplied to C<new_verifier> are stored in the verifier
+and will apply to all authreqs made from it unless overridden in the
+call to C<new_request>
+
+=over
+
+=head2 GENERAL SETTINGS
+
+=item C<dir>
+
+The directory CGI::Auth::Generic should use for its data storage.
+This is actually just a default absolute path used when the other
+path settings are relative values.
+
+Must be an absolute filename.
+
+=item C<assocdb_dbh>
+
+CGI::Auth::Flexible needs a database for recording users' login
+session.  This database needs to be shared across all instances of the
+web application, so in a multi-node cluster it needs to be your actual
+database.
+
+CGI::Auth::Flexible will create the table and index it needs if they
+don't already exist, and will manage their contents.  You do not need
+to integrate them into the rest of your webapp's data storage.  (In
+particular, there is no need for transactional integrity across
+changes made by CAF and your own application.)
+
+By default, CAF uses a sqlite3 database stored on local disk in the
+file named by C<assocdb_path>.  This will be suitable for all
+applications which run on a single host.
+
+This value, if supplied, should be a DBI handle for the database.
+
+=item C<assocdb_dsn>
+
+This is the DSN to pass to C<< DBI->connect >>.  Used only if
+C<assocdb_dbh> is not supplied.
+
+=item C<assocdb_path>
+
+Path to the sqlite3 database used for CAF's session storage.  The
+default is currently C<caf-assocs.db> but will change in the future.
+
+Used only if neither C<assocdb_dbh> or C<assocdb_dsn> are supplied.
+
+If this is a relative path, it is in C<dir>.
+
+=item C<assocdb_table>
+
+Prefix for the SQL tables and indices to use (and to create, if
+necessary).
+
+See L</DATABASE TABLES>.
+
+=item C<keys_path>
+
+Path to the keys file used by CAF.  This arrangement will change in
+the future.  See L</BUGS>.
+
+=item C<random_source>
+
+Special file to read random numbers from.  Should return
+cryptographically secure (pseudo)-random bytes, unpredictable to
+adversaries (even ones on the same machine).
+
+On Linux, there is no device which is properly suitable.  This is a
+bug in Linux.  You can use C</dev/random> which can block
+unnecessarily even though the kernel PRNG has been properly seeded and
+is fine, or C</dev/urandom> which might return values which attackers
+can predict if the kernel PRNG has not been properly seeded.
+
+The default is C</dev/urandom>.
+
+=item C<secretbits>
+
+Length of the assoc secret.  Defaults to 128.
+
+=item C<hash_algorithm>
+
+Must be a string suitable for use with C<new Digest>.
+Defaults to C<SHA-256>.
+
+=item C<login_timeout>
+
+A user will be logged out this many seconds after they first logged
+in.  Default: 86400 (one day).
+
+=item C<login_form_timeout>
+
+A login form becomes invalid this many seconds after it has been sent.
+Default: 3600 seconds (one hour).
+
+=item C<key_rollover>
+
+The key used for generating assoc secrets is rolled over approximately
+this often (in seconds).  Default: 86400.
+
+=item C<assoc_param_name>
+
+Name of the hidden form parameter.  Default: C<caf_assochash>.
+
+=item C<dummy_param_name_prefix>
+
+Some of CAF's HTML-generating functions need to invent form parameter
+names.  They will all start with this string.  Default: C<caf__>.
+
+=item C<cookie_name>
+
+Name of the cookie used for login sessions.  Default:
+C<caf_assocsecret>.
+
+=item C<password_param_name>
+
+Name of the password field in the login form.  Default: C<password>.
+
+Used by C<login_ok_password> (the default C<login_ok> hook),
+C<gen_plain_login_form> and the default C<is_login> hook.
+
+=item C<srcdump_param_name>
+
+Form parameter name used to indicate that this is a source download
+request.  If this parameter is supplied, C<check_ok> and
+C<check_divert> will arrange for the applicaton source code to be
+delivered as the response (in C<check_ok>'s case by doing it itself
+and in C<check_divert>'s case by asking your application to do so.
+
+Default is C<caf_srcdump>.
+
+=item C<username_param_names>
+
+Arrayref of name(s) of username form parameters.
+
+The first entry is used by C<login_ok_password> (the default
+C<login_ok> hook) to pass to the C<username_password_error> hook and
+used as the username if all is well.
+
+All the entries are used by C<gen_plain_login_fork> (the default
+C<gen_login_form> hook for C<check_ok>) to generate form entry fields.
+
+The default is C<['username']>.
+
+=back
+
+=head2 SETTINGS FOR SOURCE CODE DOWNLOAD FACILITY
+
+=over
+
+=item C<srcdump_path>
+
+Path to the directory used for storing pre-prepared source downloads.
+Defaults to C<caf-srcdump>.
+
+If this is a relative path, it is in C<dir>.
+
+=back
+
+
+
+=head1 DATABASE TABLES
+
+In a simple application, you do not need to worry about this.  But if
+your application runs on multiple frontend hosts with a shared
+database, you may need to create for yourself the tables and indices
+used by CGI::Auth::Flexible.
+
+xxx document _db_setup_do
+xxx make _db_setup_do explicitly overrideable
 
 
 xxx divert spec
@@ -510,3 +692,10 @@ xxx reqtype
 xxx settings
 xxx html generators
 xxx document cookie
+
+xxx bugs wrong default random on Linux
+xxx bugs wrong default random on *BSD
+xxx bugs keys not shared should be in db
+xxx rename caf-assocs.db
+xxx rename caf_assocsecret default cookie name
+xxx mention relationship between login_timeout and cookies