X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=cgi-auth-flexible.git;a=blobdiff_plain;f=cgi-auth-hybrid.pm;h=68a73809bdfebfd9fe88b1d2bdb5dfb3472041ed;hp=44058fc71cf93e80a7007b2c48396d101e59accb;hb=9c884995f0abeb3b8406cb9579d51d272183eeee;hpb=e0b5d2156bf63b93189ce95ca70467300059c6e9

diff --git a/cgi-auth-hybrid.pm b/cgi-auth-hybrid.pm
index 44058fc..68a7380 100644
--- a/cgi-auth-hybrid.pm
+++ b/cgi-auth-hybrid.pm
@@ -1,5 +1,21 @@
 # -*- perl -*-
 
+# This is part of CGI::Auth::Hybrid, a perl CGI authentication module.
+# Copyright (C) 2012 Ian Jackson.
+# 
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# 
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+# 
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 BEGIN {
     use Exporter   ();
     our ($VERSION, @ISA, @EXPORT, @EXPORT_OK, %EXPORT_TAGS);
@@ -13,74 +29,555 @@ BEGIN {
 }
 our @EXPORT_OK;
 
-our %_s = (
-    assocdb_path => 'cah-assocs.db';
-    assocdb_dsn => undef,
-    assocdb_user => '',
-    assocdb_password => '',
-    assocdb_table => 'assocs',
-    random_source => '/dev/urandom',
-    associdlen => 128, # bits
-    param_name => 'cah_associd',
-    cookie_name => 'cah_associd', # make undef to disable cookie
-    param_get => sub { _c()->param($s_{param_name}) },
-    cookie_get => sub { $_s{cookie_name} ? _c()->param($s_{cookie_name}) : '' },
-    );
-
 use DBI;
+use CGI;
 
-our $dbh;
+#---------- default callbacks ----------
 
-sub new {
+sub has_a_param ($$) {
+    my ($c,$cn) = @_;
+    foreach my $pn (@{ $r->{S}{$cn} }) {
+	return 1 if $r->_cm('get_param')($pn);
+    }
+    return 0;
+}
+
+sub get_param_list ($$) {
+    my ($c) = @_;
+    my @p = ( );
+    foreach my $name ($c->param()) {
+	foreach my $val ($c->param($name)) {
+	    push @p, $name, $val;
+	}
+    }
+    return @p;
+}
+
+#---------- verifier object methods ----------
+
+sub new_verifier {
+    my $class = shift;
+    my $s = {
+	S => {
+	    assocdb_path => 'cah-assocs.db';
+	    assocdb_dsn => undef,
+	    assocdb_user => '',
+	    assocdb_password => '',
+	    assocdb_table => 'assocs',
+	    random_source => '/dev/urandom',
+	    associdlen => 128, # bits
+	    login_timeout => 86400, # seconds
+	    assoc_param_name => 'cah_associd',
+	    password_param_name => 'password',
+	    logout_param_names => [qw(cah_logout)],
+	    loggedout_param_names => [qw(cah_loggedout)],
+	    promise_check_mutate => 0,
+	    get_param => sub { $_[0]->param($_[2]) },
+	    get_param_list => sub { $_[1]->get_param_list() },
+	    get_cah_cookie => sub { $_[0]->cookie($s->{S}{cookie_name}) },
+	    get_method => sub { $_[0]->request_method() },
+	    get_url => sub { $_[0]->url(); },
+            is_login => sub { defined $_[1]->_rp('password_param_name') },
+            login_ok => sub { die },
+	    is_logout => sub { $_[1]->has_a_param('logout_param_names') },
+	    is_loggedout => sub { $_[1]->has_a_param('loggedout_param_names') },
+	    is_page => sub { return 1 },
+	},
+	Dbh => undef,
+    };
     my ($k,$v);
     while (($k,$v,@_) = @_) {
-	die "unknown setting $k" unless %_s{$k};
-	$_s{$k} = $v;
+	die "unknown setting $k" unless exists $s->{S}{$k};
+	$s->{S}{$k} = $v;
     }
+    bless $s, $class;
+    $s->_dbopen();
+    return $s;
 }
 
-sub _dbopen () {
-    return if $dbh;
+sub _dbopen ($) {
+    my ($s) = @_;
+    my $dbh = $s->{Dbh};
+    return $dbh if $dbh; 
 
-    $_s{assocdb_dsn}="dbi:SQLite:dbname=$s_{assocdb_path}" 
-	if !$_s{assocdb_dsn};
+    $s->{S}{assocdb_dsn} ||= "dbi:SQLite:dbname=$s->{S}{assocdb_path}";
 
     my $u = umask 077;
-    $dbh = DBI->open($_s{assocdb_dsn}, $s_{assocdb_user}, 
-		     $s_{assocdb_password}, { 
+    $dbh = DBI->open($s->{S}{assocdb_dsn}, $s->{S}{assocdb_user}, 
+		     $s->{S}{assocdb_password}, { 
 			 AutoCommit => 0, RaiseError => 1,
 		     });
     die "${assocdb_dsn} $! ?" unless $dbh;
+    $s->{Dbh} = $dbh;
 
     $dbh->do("BEGIN");
 
     eval {
-	$dbh->do("CREATE TABLE $_s{assocdb_table} (".
-		 " associd VARCHAR PRIMARY KEY,".
-                 " username VARCHAR".
+	$dbh->do("CREATE TABLE $s->{S}{assocdb_table} (".
+		 " associdh VARCHAR PRIMARY KEY,".
+                 " username VARCHAR,".
+		 " last INTEGER NOT NULL"
 		 ")");
     };
+    return $dbh;
+}
+
+#---------- request object methods ----------
+
+sub new_request {
+    my ($classbase, $cgi, @extra) = @_;
+    if (!ref $classbase) {
+	$classbase = $classbase->new_verifier(@extra);
+    } else {
+	die if @extra;
+    }
+    my $r = {
+	S => $classbase->{S},
+	Dbh => $classbase->{Dbh},
+	Cgi => $cgi,
+    };
+    bless $r, ref $classbase;
+}
+
+sub _ch ($$@) { # calls an application hook
+    my ($r,$methname, @args) = @_;
+    my $methfunc = $r->{S}{$methname};
+    return $methfunc->($r->{Cgi}, $r, @args);
+}
+
+sub _rp ($$@) {
+    my ($r,$pnvb) = @_;
+    my $pn = $r->{S}{$pnvb};
+    my $p = scalar $r->_ch('get_param',$pn)
+}
+
+# pages/param-sets are
+#   n normal non-mutating page
+#   r retrieval of information for JS, non-mutating
+#   m mutating page
+#   u update of information by JS, mutating
+#   i login
+#   o logout
+#   O "you have just logged out" page load
+
+# in cook and par,
+#    a, aN     anything including -
+#    t, tN     temporary value (in our db, no logged in user yet)
+#    y, yN     value corresponds to logged-in user
+#    n, nN     value not in our db
+#    x, xN     t or y
+#    -         no value supplied
+# if N differs the case applies only when the two values differ
+# (eg,   a1 y2   does not apply when the logged-in value is supplied twice)
+
+# "stale session" means request originates from a page from a login
+# session which has been revoked (eg by logout); "cleared session"
+# means request originates from a browser which has a different (or
+# no) cookie.
+
+    # Case analysis, cookie mode, app promises re mutate:
+    # cook parm meth form
+    #                      
+    #  any -   POST  nrmuoi   bug or attack, fail
+    #  any -   GET    rmuoi   bug or attack, fail
+    #  any any GET     muoi   bug or attack, fail
+    #  any t   any   nrmu     bug or attack, fail
+    #
+    #  -   -   GET         O  "just logged out" page
+    #  (any other)         O  bug or attack, fail
+    #
+    #  a1  a2  POST      o    logout
+    #                           if a1 is valid, revoke it
+    #                           if a2 is valid, revoke it
+    #                           delete cookie
+    #                           redirect to "just logged out" page
+    #                             (which contains link to login form)
+    #
+    #  -   t   POST       i   complain about cookies being disabled
+    #                           (with link to login form)
+    #
+    #  any n   POST       i   complain about stale login form
+    #                           show new login form
+    #
+    #  x1  t2  POST       i   login (or switch user)
+    #                           if bad
+    #                             show new login form
+    #                           if good
+    #                             revoke x1 if it was valid and !=t2
+    #                             upgrade t2 to y2 in our db (setting username)
+    #                             set cookie to t2
+    #                             redirect to GET of remaining params
+    #
+    #  t1  a2  ANY   nrmu     treat as  - a2 ANY
+    #
+    #  y   -   GET   n        cross-site link
+    #                           show data
+    #
+    #  y   y   GET   nr       fine, show page or send data
+    #  y   y   POST  nrmu     mutation is OK, do operation
+    #
+    #  y1  y2  GET   nr       request from stale page
+    #                           do not revoke y2 as not RESTful
+    #                           treat as   y1 n GET
+    #
+    #  y1  y2  POST  nrmu     request from stale page
+    #                           revoke y2
+    #                           treat as   y1 n POST
+    #
+    #  y   n   GET   n        intra-site link from stale page,
+    #                           treat as cross-site link, show data
+    #
+    #  y   n   POST  n m      intra-site form submission from stale page
+    #                           show "session interrupted"
+    #                           with link to main data page
+    #
+    #  y   n   GET    r       intra-site request from stale page
+    #                           fail
+    #
+    #  y   n   POST   r u     intra-site request from stale page
+    #                           fail
+    #
+    #  -/n y2  GET   nr       intra-site link from cleared session
+    #                           do not revoke y2 as not RESTful
+    #                           treat as   -/n n GET
+    #
+    #  -/n y2  POST  nrmu     request from cleared session
+    #                           revoke y2
+    #                           treat as   -/n n POST
+    #
+    #  -/n n   GET   n        cross-site link but user not logged in
+    #                           show login form with redirect to orig params
+    #
+    #  -/n n   GET    rmu     user not logged in
+    #                           fail
+    #
+    #  -/n n   POST  n m      user not logged in
+    #                           show login form
+    #
+    #  -/n n   POST   r u     user not logged in
+    #                           fail
+
+sub _check_divert_core ($) {
+fixme needs wrapping with something to make and commit a transaction
+    my ($r) = @_;
+
+    my $meth = $r->_ch('get_method');
+    my $cookv = $r->_ch('get_cah_cookie');
+    my $parmv = $r->_rp('assoc_param_name');
+
+    my ($cookt,$cooku) = $r->_db_lookup($cookv);
+    my $parmt = $r->_db_lookup($parmv);
+
+    if ($r->_ch('is_logout')) {
+	$r->_must_be_post();
+	die unless $parmt;
+	$r->_db_revoke($cookv);
+	$r->_db_revoke($parmv);
+	return ({ Kind => 'REDIRECT/LOGGEDOUT',
+		  Message => "Logging out...",
+		  Cookie => '',
+		  Params => [ ] });
+    }
+    if ($r->_ch('is_loggedout')) {
+	die unless $meth eq 'GET';
+	die unless $cookt;
+	die unless $parmt;
+	return ({ Kind => 'SMALLPAGE/LOGGEDOUT',
+		  Message => "You have been logged out.",
+		  Cookie => '',
+		  Params => [ ] });
+    }
+    if ($r->_ch('is_login')) {
+	$r->_must_be_post();
+	return ({ Kind => 'LOGIN-STALE',
+		  Message => "Stale session; you need to log in again.",
+		  Cookie => $r->_fresh_cookie(),
+		  Params => [ ] })
+	    if $parmt eq 'n';
+	die unless $parmt eq 't' || $parmt eq 'y';
+	return ({ Kind => 'SMALLPAGE-NOCOOKIE',
+		  Message => "You do not seem to have cookies enabled.  ".
+		      "You must enable cookies as we use them for login.",
+		  Cookie => $r->_fresh_cookie(),
+		  Params => $r->_chain_params() })
+	    if !$cookt && $parmt eq 't';
+	return ({ Kind => 'LOGIN-BAD',
+		  Message => "Incorrect username/password.",
+		  Cookie => $cookv,
+		  Params => $r->_chain_params() })
+	    unless defined $username && length $username;
+	$r->_db_revoke($cookv) 
+	    if defined $cookv && !(defined $parmv && $cookv eq $parmv);
+	my $username = $r->_ch('login_ok');
+	$r->_db_record_login_ok($parmv,$username);
+	return ({ Kind => 'REDIRECT-LOGGEDIN',
+		  Message => "Logging in...",
+		  Cookie => $parmv,
+		  Params => $r->_chain_params() });
+    }
+    if ($cookt eq 't') {
+	$cookt = '';
+    }
+    die if $parmt eq 't';
+
+    if ($cookt eq 'y' && $parmt eq 'y' && $cookv ne $parmv) {
+	$r->_db_revoke($parmv) if $meth eq 'POST';
+	$parmt = 'n';
+    }
+
+    if ($cookt ne 'y') {
+	die unless !$cookt || $cookt eq 'n';
+	die unless !$parmt || $parmt eq 'n' || $parmt eq 'y';
+	if ($meth eq 'GET') {
+	    return ({ Kind => 'LOGIN-INCOMINGLINK',
+		      Message => "You need to log in again.",
+		      Cookie => $parmv,
+		      Params => $r->_chain_params() });
+	} else {
+	    return ((Kind => 'LOGIN-FRESH',
+		     Message => "You need to log in again.",
+		     Cookie => $parmv,
+		     Params => [ ]);
+	}
+    }
+
+    if (!$r->{S}{promise_check_mutate}) {
+	if ($meth ne 'POST') {
+	    return ({ Kind => 'MAINPAGEONLY',
+		      Message => 'Entering via cross-site link.',
+		      Cookie => $cookv,
+		      Params => [ ] });
+	    # NB caller must then ignore params & path!
+	    # if this is too hard they can spit out a small form
+	    # with a "click to continue"
+	}
+    }
+
+    die unless $cookt eq 'y';
+    die unless $parmt eq 'y';
+    die unless $cookv eq $parmv;
+    $r->{UserOK} = $cooku;
+    return undef;
+}
+
+sub _chain_params ($) {
+    my ($r) = @_;
+    my %elim = { };
+    foreach my $pncn (keys %{ $r->{S} }) {
+	if ($pncn =~ m/_param_name$/) {
+	    my $name = $r->{S}{$pncn};
+	    die "$pncn ?" if ref $name;
+	    $names = [ $name ];
+	} elsif ($pncn =~ m/_param_names$/) {
+	    $names = $r->{S}{$pncn};
+	} else {
+	    next;
+	}
+	foreach my $param (@$names) {
+	    $elim{$name} = 1;
+	}
+    }
+    my @p = $r->_ch('get_param_list');
+    my ($name,$val);
+    my @q = ();
+    while (@p) {
+	($name,$val,@p) = @p;
+	next if $elim{$name};
+	push @q, $name, $val;
+    }
+    return @q;
+}
+
+sub _db_lookup ($$) {
+    # returns ($t,$username)
+    # where $t is one of "t" "y" "n", or "" (for -)
+    my ($r,$v) = @_;
+
+    my $dbh = $r->{Dbh};
+
+    my ($nusername, $nlast) =
+	$dbh->selectrow_array("SELECT username, last".
+			      " FROM $r->{S}{assocdb_table}".
+			      " WHERE associd = ?", {}, $nassoc);
+    return ('') unless defined $nusername;
+
+    my $timeout = $r->{S}{login_timeout};
+    return ('n') unless !defined $timeout || time <= $nlast + $timeout;
+
+    return ('t') unless defined $nusername;
+
+    # hooray
+    return ('y', $nusername);
+}
+
+sub _db_revoke ($$) {
+    # revokes $v if it's valid; no-op if it's not
+    my ($r,$v) = @_;
+
+    my $dbh = $r->{Dbh};
+
+    $dbh->do("DELETE FROM $r->{S}{assocdb_table}".
+	     " WHERE associd = ?", {}, $v);
+}
+
+sub _db_record_login_ok ($$$) {
+    my ($r,$v,$user) = @_;
+    $r->_db_revoke($v);
+    $dbh->do("INSERT INTO $r->{S}{assocdb_table}".
+	     " (associd, username, last) VALUES (?,?,?)", {},
+	     $v, $user, time);
 }
 
-sub record_login ($) {
-    my ($nusername) = @_;
-    my $rs = new IO::File $_s{random_source}, '<'
-	or die "$_s{random_source} $!";
-    my $bytes = ($_s{associdlen} + 7) >> 3;
+sub url_with_query_params ($@) {
+    my ($r, @params) = @_;
+    my $uri = URI->new($r->_ch('get_url'));
+    $uri->query_form(\@params);
+    return $uri->as_string();
+}
+
+sub check_ok ($) {
+    my ($r) = @_;
+
+    my ($divert) = $authreq->check_divert();
+    return 1 if $divert;
+
+    my $kind = $divert->{Kind};
+    my $cookie = $divert->{Cookie};
+    my $params = $divert->{Params};
+
+    if (defined $cookie) {
+        $r->_ch('header_out')($cookie);
+    }
+    if ($kind =~ m/^REDIRECT-/) {
+	# for redirects, we honour stored NextParams and SetCookie,
+	# as we would for non-divert
+	my $new_url = $r->_ch('get_url');
+	if ($divert_kind eq 'REDIRECT-LOGGEDOUT') {
+	    push @$params, $r->{S}{cah_loggedout}[0], 1;
+	} elsif ($divert_kind eq 'REDIRECT-LOGOUT') {
+	    push @$params, $r->{S}{cah_logout}[0], 1;
+	} elsif ($divert_kind eq 'REDIRECT-LOGGEDIN') {
+	}
+
+UP TO HERE
+
+sub record_login ($$) {
+    my ($r,$nusername) = @_;
+    my $rsp = $r->{S}{random_source};
+    my $rsf = new IO::File $rsp, '<' or die "$rsp $!";
+    my $bytes = ($r->{S}{associdlen} + 7) >> 3;
     my $nassocbin;
     $!=0;
-    read($rs,$nassocbin,$bytes) == $bytes or die "$s_{random_source} $!";
+    read($rsf,$nassocbin,$bytes) == $bytes or die "$rsp $!";
+    close $rsf;
     my $nassoc = unpack "H*", $nassocbin;
-    _dbopen();
-    $dbh->do("INSERT INTO $_s{assocdb_table}".
-	     " (associd, username) VALUES (?,?)", {},
-	     $nassoc, $nusername);
+    my $dbh = $r->{Dbh};
+    $dbh->do("INSERT INTO $r->{S}{assocdb_table}".
+	     " (associd, username, last) VALUES (?,?,?)", {},
+	     $nassoc, $nusername, time);
+    $dbh->do("COMMIT");
+    $r->{U} = $nusername;
+    $r->{A} = $nassoc;
+}
+
+sub _check ($) {
+    my ($r) = @_;
+
+    return if exists $r->{Username};
+    ($r->{Username}, $r->{Assoc}, $r->{Mutate}) = $r->_check();
+
+    if (defined $r->{Assoc}) {
+	$dbh->do("UPDATE $r->{S}{assocdb_table}".
+		 " SET last = ?".
+		 " WHERE associd = ?", {}, time, $nassoc);
+	$dbh->do("COMMIT");
+    }
+}
+
+sub logout ($) {
+    my ($r) = @_;
+
+    my ($nusername, $nassoc, $nmutate) = $r->_check();
+    return undef unless $nmutate;
+    $dbh->do("DELETE FROM $r->{S}{assocdb_table}".
+	     " WHERE associd = ?", {}, $nassoc);
     $dbh->do("COMMIT");
-    $username = $nusername;
-    $assoc =    $nassoc;
+    return $nusername;
 }
 
-sub check () {
-    my $passocid = $_s{param_get}();
-    my $cassocid = $_s{cookie_get}();
-    if (
+sub check ($) {
+    my ($r) = @_;
+    $r->_check();
+    return !!defined $r->{Username};
+}
+
+sub check_mutate ($) {
+    my ($r) = @_;
+    $r->check();
+    return $r->{Mutate};
+}
+
+sub username ($) {
+    my ($r) = @_;
+    $r->check();
+    return $r->{Username};
+
+sub hidden_val ($) {
+    my ($r) = @_;
+    $r->check();
+    return defined $r->{Assoc} ? $r->{Assoc} : '';
+}
+
+#---------- simple wrappers ----------
+
+sub hidden_hargs ($) {
+    my ($r) = @_;
+    return (-name => $r->{S}{param_name},
+	    -default => $r->hidden_val());
+}
+
+sub hidden_html ($) {
+    my ($r) = @_;
+    return hidden($r->hidden_hargs());
+}
+
+sub cookiea_cargs ($) {
+    my ($r) = @_;
+    return (-name => $r->{S}{cookie_name},
+	    -value => hidden_val());
+}
+
+__END__
+
+=head1 NAME
+
+CGI::Auth::Hybrid - web authentication optionally using cookies
+
+=head1 SYNOPSYS
+
+ my $verifier = CGI::Auth::Hybrid->new_verifier(setting => value,...);
+ my $authreq = $verifier->new_request($cgi_request_object);
+
+ my $authreq = CGI::Auth::Hybrid->new_request($cgi_request_object,
+                                              setting => value,...);
+
+=head1 USAGE PATTERN FOR SIMPLE APPLICATIONS
+
+ $authreq->check_ok() or return;
+
+ blah blah blah
+ $authreq->mutating();
+ blah blah blah
+
+=head1 USAGE PATTERN FOR FANCY APPLICATIONS
+
+ my $divert_kind = $authreq->check_divert();
+ if ($divert_kind) {
+     if ($divert_kind eq 'LOGGEDOUT') {
+	 print "goodbye you are now logged out" and quit
+     } elsif ($divert_kind eq 'NOCOOKIES') {
+	 print "you need cookies" and quit
+     ... etc.
+     }
+ }
+