X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=cgi-auth-hybrid.pm;h=f8c74ae63789b83927451bd939d761ed0c01a16c;hb=21e5e43683e3b969da7fd68669852634f43d34d5;hp=f7b48aa1ef4ccbd96ff156a66036202196349221;hpb=e1f49099d0f659ece466813a04a3c0afdcbf299c;p=cgi-auth-flexible.git

diff --git a/cgi-auth-hybrid.pm b/cgi-auth-hybrid.pm
index f7b48aa..f8c74ae 100644
--- a/cgi-auth-hybrid.pm
+++ b/cgi-auth-hybrid.pm
@@ -32,6 +32,56 @@ our @EXPORT_OK;
 use DBI;
 use CGI;
 
+#---------- default callbacks ----------
+
+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;
+}
+
+sub get_cookie_domain ($$$) {
+    my ($c,$r) = @_;
+    my $uri = new URI $r->_ch('get_url');
+    return $uri->host();
+}
+
+sub construct_cookie ($$$) {
+    my ($c, $r, $cookv) = @_;
+    return $c->cookie(-name => $r->{S}{cookie_name},
+		      -value => $cookv,
+		      -path => $r->{S}{cookie_path},
+		      -domain => $r->_ch('get_cookie_domain'),
+		      -expires => '+'.$r->{S}{login_timeout}.'s',
+		      -secure => $r->{S}{encrypted_only});
+}
+
+sub do_redirect_cgi ($$$$) {
+    my ($c, $r, $new_url, $cookie) = @_;
+    my @ha = ('text/html',
+	      -status => '303 See other',
+	      -location => $new_url);
+    push @ha, (-cookie => $cookie) if defined $cookie;
+    $r->_ch('print')($c->header(@ha).
+		     $c->start_html('Redirection').
+		     $c->a({href=>$new_url},
+			   "If you aren't redirected, click to continue.").
+		     $c->end_html());
+}			
+
 #---------- verifier object methods ----------
 
 sub new_verifier {
@@ -46,14 +96,27 @@ sub new_verifier {
 	    random_source => '/dev/urandom',
 	    associdlen => 128, # bits
 	    login_timeout => 86400, # seconds
-	    param_name => 'cah_associd',
+	    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,
-	    cookie_name => 'cah_associd', # make undef to disable cookie
-	    get_param => sub { $_[0]->param($s->{S}{param_name}) },
-	    get_cookie => sub { $s->{S}{cookie_name}
-				? $_[0]->cookie($s->{S}{cookie_name})
-				: '' },
+	    get_param => sub { $_[0]->param($_[2]) },
+	    get_param_list => sub { $_[1]->get_param_list() },
+	    get_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 { $_[1]->has_a_param('loggedout_param_names') },
+	    is_page => sub { return 1 },
+	    handle_divert => sub { return 0 },
+	    do_redirect => \&do_redirect_cgi, # this hook is allowed to throw
+	    cookie_path => "/",
+	    get_cookie_domain => \&get_cookie_domain,
+	    encrypted_only => 0,
+	    };
 	},
 	Dbh => undef,
     };
@@ -86,9 +149,9 @@ sub _dbopen ($) {
 
     eval {
 	$dbh->do("CREATE TABLE $s->{S}{assocdb_table} (".
-		 " associd VARCHAR PRIMARY KEY,".
+		 " associdh VARCHAR PRIMARY KEY,".
                  " username VARCHAR,".
-		 " last INTEGER"
+		 " last INTEGER NOT NULL"
 		 ")");
     };
     return $dbh;
@@ -111,56 +174,18 @@ sub new_request {
     bless $r, ref $classbase;
 }
 
-sub _cm ($$@) {
+sub _ch ($$@) { # calls an application hook
     my ($r,$methname, @args) = @_;
     my $methfunc = $r->{S}{$methname};
     return $methfunc->($r->{Cgi}, $r, @args);
 }
 
-sub record_login ($$) {
-    my ($r,$nusername) = @_;
-    my $rsp = $r->{S}{random_source};
-    my $rsf = new IO::File $rsp, '<' or die "$rsp $!";
-    my $bytes = ($r->{S}{associdlen} + 7) >> 3;
-    my $nassocbin;
-    $!=0;
-    read($rsf,$nassocbin,$bytes) == $bytes or die "$rsp $!";
-    close $rsf;
-    my $nassoc = unpack "H*", $nassocbin;
-    my $dbh = $r->{Dbh};
-    $dbh->do("INSERT INTO $r->{S}{assocdb_table}".
-	     " (associd, username, last) VALUES (?,?,?)", {},
-	     $nassoc, $nusername, time);
-    $dbh->do("COMMIT");
-    $r->{U} = $nusername;
-    $r->{A} = $nassoc;
+sub _rp ($$@) {
+    my ($r,$pnvb) = @_;
+    my $pn = $r->{S}{$pnvb};
+    my $p = scalar $r->_ch('get_param',$pn)
 }
 
-sub _check_core ($) {
-    my ($r) = @_;
-    my $qassoc = $r->_cm('get_param');
-    my ($nassoc,$nmutate);
-    if (!defined $r->{S}{cookie_name}) {
-	# authentication is by hidden form parameter only
-	return undef unless defined $qassoc;
-	$nassoc = $qassoc;
-	$nmutate = 1;
-    } else {
-	# authentication is by cookie
-	# the cookie suffices for read-only GET requests
-	# for mutating and non-GET requests we require hidden param too
-	my $cassoc = $r->_cm('get_cookie');
-	return undef unless defined $cassoc;
-	$nassoc = $cassoc;
-	if (defined $qassoc && $qassoc eq $cassoc) {
-	    $nmutate = 1;
-	} else {
-	    return undef unless $r->{S}{promise_check_mutate};
-	    return undef unless $r->_cm('get_method') eq 'GET';
-	    $nmutate = 0;
-	}
-    }
-
 # pages/param-sets are
 #   n normal non-mutating page
 #   r retrieval of information for JS, non-mutating
@@ -168,85 +193,336 @@ sub _check_core ($) {
 #   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 par meth  form
+    # cook parm meth form
     #                      
-    #  y   y   GET   nr       fine, show page or send data
+    #  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
     #
-    #  y   -   GET   n        cross-site link
-    #                           show data
-    #  y1  y2  GET   n        intra-site link
-    #                           from session no longer known to browser
-    #                           do not revoke y2 as not a POST so not RESTful
-    #                           treat as cross-site link, show data
-    #  y   n   GET   n        intra-site link from stale session,
-    #                           treat as cross-site link, show data
+    #  -   -   GET         O  "just logged out" page
+    #  (any other)         O  bug or attack, fail
     #
-    #  y   -   GET    r       bug or attack, fail
-    #  y1  y2  GET    r       intra-site data request
-    #                           from session no longer known to browser
-    #                           do not revoke y2 as not a POST so not RESTful
-    #                           fail
-    #  y   n   GET    r       intra-site data request from stale session
-    #                           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)
     #
-    #  -   y   GET   n           CLEAR COOKIES TO LOGOUT OPTION
+    #  -   t   POST       i   complain about cookies being disabled
+    #                           (with link to login form)
     #
-    #  -/n any GET   n        cross-site link but user not logged in
-    #                           show login form
+    #  any n   POST       i   complain about stale login form
+    #                           show new login form
     #
-    #  -/n any GET    r       data request from stale session
-    #                           fail
+    #  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
     #
-    #  any any GET     muoi   bug or attack, fail
+    #  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
-    #  y   y   POST      o    logout
-    #  y   y   POST       i   login, redirect to GET of remaining params
     #
-    #  any -   POST           bug or xsrf attack, fail
+    #  y1  y2  GET   nr       request from stale page
+    #                           do not revoke y2 as not RESTful
+    #                           treat as   y1 n GET
     #
-    #  n/y1 y2 POST  r        intra-site form submission
-    #                           from session no longer known to browser
+    #  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"
-    #  n/y1 y2 POST    m      intra-site js operation
-    #                           from session no longer known to browser
-    #                           revoke y2
+    #                           with link to main data page
+    #
+    #  y   n   GET    r       intra-site request from stale page
     #                           fail
-    #  y   n   POST  r        intra-site form submission from stale session
-    #                           show "session interrupted"
-    #  y   n   POST    m      intra-site form submission from stale session
+    #
+    #  y   n   POST   r u     intra-site request from stale page
     #                           fail
     #
-    #  -   y2  GET            intra-site link or data request
-    #                           from session no longer known to browser
+    #  -/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
 
-    #  -   y2        any      req from old session y2, del y2, show login
-    #  y1  y2        any      req from old session y2, del y2, show y1 main
+sub _check_divert_core ($) {
+fixme needs wrapping with something to make and commit a transaction
+    my ($r) = @_;
 
-    #  y1 any  GET   non-mut  cross-site link
-    #  y1 any  GET   non-mut  no mutation, show page providing new par
-    #
-    #  A   B         any      page from old session or cross-site request
-    #  any y2 POST  logout    do logout y2
+    my $meth = $r->_ch('get_method');
+    my $cookv = $r->_ch('get_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"
+	}
+    }
 
-    #  any any GET   mutate   bug or attack, forbidden, call die
+    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 undef unless defined $nusername;
+    return ('') unless defined $nusername;
+
     my $timeout = $r->{S}{login_timeout};
-    return undef unless !defined $timeout || time <= $nlast + $timeout;
+    return ('n') unless !defined $timeout || time <= $nlast + $timeout;
+
+    return ('t') unless defined $nusername;
 
     # hooray
-    return ($nusername, $nassoc, $nmutate);
+    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, $user, time);
+}
+
+sub url_with_query_params ($@) {
+    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 $handled = $r->_ch('handle_divert')($divert);
+    return 0 if $handled;
+
+    my $kind = $divert->{Kind};
+    my $cookie = $divert->{Cookie};
+    my $params = $divert->{Params};
+
+    if ($kind =~ m#^REDIRECT/#) {
+	# for redirects, we honour stored NextParams and SetCookie,
+	# as we would for non-divert
+	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') {
+	} else {
+	    die;
+	}
+	my $new_url = $r->url_with_query_params(@$params);
+	$r->_ch('do_redirect')($new_url, $cookie);
+	return 0;
+    }
+    
+
+if (defined $cookie) {
+        $r->_ch('header_out')($cookie);
+    }
+    
+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;
+    $!=0;
+    read($rsf,$nassocbin,$bytes) == $bytes or die "$rsp $!";
+    close $rsf;
+    my $nassoc = unpack "H*", $nassocbin;
+    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 ($) {
@@ -332,41 +608,21 @@ CGI::Auth::Hybrid - web authentication optionally using cookies
 
 =head1 USAGE PATTERN FOR SIMPLE APPLICATIONS
 
- if ( form submission is login request ) {
-     check login details, if wrong print error and quit
-     $authreq->record_login(...username...);
- }
- if ( form submission is logout request ) {
-     my $logged_out_user = $authreq->logout();
-     if (!defined $logged_out_user) {
-	 print "you are not logged in" error and quit
-     } else {
-	 print "goodbye $username you are now logged out" and quit
-     }
- }
- if ( !$authreq->check() ) {
-     display login form, quit
+ $authreq->check_ok() or return;
 
+ blah blah blah
+ $authreq->mutating();
+ blah blah blah
 
 =head1 USAGE PATTERN FOR FANCY APPLICATIONS
 
- if ( form submission is login request ) {
-     check login details, if wrong print error and quit
-     $authreq->record_login(...username...);
- }
- if ( !$authreq->check() ) {
-     display login form, quit
- if ( form submission is logout request ) {
-     die unless $authreq->mutate();
-     my $logged_out_user = $authreq->logout();
-     if (!defined $logged_out_user) {
-	 print "you are not logged in" error and quit
-     } else {
-	 print "goodbye $username you are now logged out" and quit
+ 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.
      }
  }
 
-
-advantages of cookie
- - user can sort of log out by clearing cookies
- - sophisticated applications can have get-requests