X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=cgi-auth-hybrid.pm;h=6d2838764ea5f477a8ed66e59b58e02e91d84e4c;hb=b2d0c9b920f19f5fd913686e243fc66cd1e53b53;hp=f7b48aa1ef4ccbd96ff156a66036202196349221;hpb=e1f49099d0f659ece466813a04a3c0afdcbf299c;p=cgi-auth-flexible.git

diff --git a/cgi-auth-hybrid.pm b/cgi-auth-hybrid.pm
index f7b48aa..6d28387 100644
--- a/cgi-auth-hybrid.pm
+++ b/cgi-auth-hybrid.pm
@@ -32,6 +32,16 @@ our @EXPORT_OK;
 use DBI;
 use CGI;
 
+#---------- default callbacks ----------
+
+sub _def_is_logout ($$) {
+    my ($c,$r) = @_;
+    foreach my $pn (@{ $r->{S}{logout_param_names} }) {
+	return 1 if $r->_cm('get_param')($pn);
+    }
+    return 0;
+}
+
 #---------- verifier object methods ----------
 
 sub new_verifier {
@@ -46,14 +56,17 @@ 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(logout)],
 	    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_cah_cookie => sub { $_[0]->cookie($s->{S}{cookie_name}) },
 	    get_method => sub { $_[0]->request_method() },
+            is_login => sub { defined $_[1]->_rp('password_param_name') },
+            login_ok => sub { die },
+	    is_logout => \&_def_is_logout,
+	    is_page => sub { return 1 },
 	},
 	Dbh => undef,
     };
@@ -86,9 +99,9 @@ sub _dbopen ($) {
 
     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 +124,18 @@ 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 = $r->_ch('get_param',$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';
-	    $nmutate = 0;
-	}
-    }
-
 # pages/param-sets are
 #   n normal non-mutating page
 #   r retrieval of information for JS, non-mutating
@@ -169,72 +144,152 @@ sub _check_core ($) {
 #   i login
 #   o logout
 
+
+# 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   nrmuo    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
+    #  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    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
+    #  -   t   POST       i   complain about cookies being disabled
     #
-    #  -   y   GET   n           CLEAR COOKIES TO LOGOUT OPTION
+    #  any n   POST       i   complain about stale login form
+    #                           show new login form
     #
-    #  -/n any GET   n        cross-site link but user not logged in
-    #                           show login form
+    #  x1  t2  POST       i   login (or switch user)
+    #                           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
     #
-    #  -/n any GET    r       data request from stale session
-    #                           fail
+    #  t1  a2  ANY   nrmu     treat as  - a2 ANY
     #
-    #  any any GET     muoi   bug or attack, fail
+    #  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
+    #
+    #  -/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
     #
-    #  -   y2  GET            intra-site link or data request
-    #                           from session no longer known to browser
+    #  -/n n   POST  nrmu     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 ($) {
+    my ($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 $cookv = $r->_ch('get_cah_cookie');
+    my $parmv = $r->_rp('assoc_param_name');
+
+    my $cookt = $r->_db_lookup($cookv);
+    my $parmt = $r->_db_lookup($parmv);
+
+    if ($r->_ch('is_logout')) {
+	$r->_must_be_post();
+	die unless $parmt;
+	$r->_db_perhaps_revoke($cookv);
+	$r->_db_perhaps_revoke($parmv);
+	return 'LOGOUT';
+    }
+    if ($r->_ch('is_login')) {
+	return 'NOCOOKIE' if !$cookt && $parmt eq 't';
+	return 'LOGIN-STALE' if $parmt eq 'n';
+	$r->_db_perhpa
+	my $username = $r->_ch('login_ok');
+	return 'LOGIN-BAD' unless defined $username && length $username;
+	$r->_db_
+
+	}
+	
+
+	$r->_will_set_cookie('');
+	
+    }
 
 
-    #  any any GET   mutate   bug or attack, forbidden, call die
+UP TO HERE
+
+sub _check_core ($) {
+    my ($r) = @_;
+    my $qassoc = $r->_ch('get_param');
+    my ($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->_ch('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->_ch('get_method') eq 'GET';
+	    $nmutate = 0;
+	}
+    }
 
     my $dbh = $r->{Dbh};
     my ($nusername, $nlast) =
@@ -249,6 +304,25 @@ sub _check_core ($) {
     return ($nusername, $nassoc, $nmutate);
 }
 
+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} = $nassoc;
+}
+
 sub _check ($) {
     my ($r) = @_;
 
@@ -332,41 +406,21 @@ 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