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Original Path: trunk/webwork2/lib/WeBWorK/Authen.pm
| 1 : | sh002i | 455 | ################################################################################ |
| 2 : | sh002i | 1663 | # WeBWorK Online Homework Delivery System |
| 3 : | # Copyright © 2000-2003 The WeBWorK Project, http://openwebwork.sf.net/ | ||
| 4 : | gage | 1719 | # $CVSHeader: webwork-modperl/lib/WeBWorK/Authen.pm,v 1.25 2004/01/03 17:12:55 gage Exp $ |
| 5 : | sh002i | 1663 | # |
| 6 : | # This program is free software; you can redistribute it and/or modify it under | ||
| 7 : | # the terms of either: (a) the GNU General Public License as published by the | ||
| 8 : | # Free Software Foundation; either version 2, or (at your option) any later | ||
| 9 : | # version, or (b) the "Artistic License" which comes with this package. | ||
| 10 : | # | ||
| 11 : | # This program is distributed in the hope that it will be useful, but WITHOUT | ||
| 12 : | # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | ||
| 13 : | # FOR A PARTICULAR PURPOSE. See either the GNU General Public License or the | ||
| 14 : | # Artistic License for more details. | ||
| 15 : | sh002i | 455 | ################################################################################ |
| 16 : | |||
| 17 : | malsyned | 305 | package WeBWorK::Authen; |
| 18 : | |||
| 19 : | sh002i | 455 | =head1 NAME |
| 20 : | |||
| 21 : | WeBWorK::Authen - Check user identity, manage session keys. | ||
| 22 : | |||
| 23 : | =cut | ||
| 24 : | |||
| 25 : | malsyned | 441 | use strict; |
| 26 : | use warnings; | ||
| 27 : | sh002i | 1683 | use Apache::Cookie; |
| 28 : | sh002i | 1685 | use Apache::Util qw(unescape_uri_info); |
| 29 : | sh002i | 1683 | use Data::Dumper; |
| 30 : | malsyned | 335 | |
| 31 : | malsyned | 305 | sub new($$$) { |
| 32 : | malsyned | 323 | my $invocant = shift; |
| 33 : | my $class = ref($invocant) || $invocant; | ||
| 34 : | malsyned | 305 | my $self = {}; |
| 35 : | sh002i | 817 | ($self->{r}, $self->{ce}, $self->{db}) = @_; |
| 36 : | malsyned | 305 | bless $self, $class; |
| 37 : | return $self; | ||
| 38 : | } | ||
| 39 : | |||
| 40 : | sh002i | 817 | sub checkPassword($$$) { |
| 41 : | my ($self, $userID, $possibleClearPassword) = @_; | ||
| 42 : | sh002i | 1636 | my $Password = $self->{db}->getPassword($userID); # checked |
| 43 : | return 0 unless defined $Password; | ||
| 44 : | sh002i | 817 | my $possibleCryptPassword = crypt($possibleClearPassword, $Password->password()); |
| 45 : | return $possibleCryptPassword eq $Password->password(); | ||
| 46 : | } | ||
| 47 : | |||
| 48 : | sub generateKey($$) { | ||
| 49 : | my ($self, $userID) = @_; | ||
| 50 : | my @chars = @{ $self->{ce}->{sessionKeyChars} }; | ||
| 51 : | my $length = $self->{ce}->{sessionKeyLength}; | ||
| 52 : | malsyned | 323 | srand; |
| 53 : | sh002i | 817 | my $key = join ("", @chars[map rand(@chars), 1 .. $length]); |
| 54 : | return WeBWorK::DB::Record::Key->new(user_id=>$userID, key=>$key, timestamp=>time); | ||
| 55 : | } | ||
| 56 : | |||
| 57 : | sub checkKey($$$) { | ||
| 58 : | my ($self, $userID, $possibleKey) = @_; | ||
| 59 : | sh002i | 1636 | my $Key = $self->{db}->getKey($userID); # checked |
| 60 : | return 0 unless defined $Key; | ||
| 61 : | sh002i | 817 | if (time <= $Key->timestamp()+$self->{ce}->{sessionKeyTimeout}) { |
| 62 : | if ($possibleKey eq $Key->key()) { | ||
| 63 : | # unexpired and matches -- update timestamp | ||
| 64 : | $Key->timestamp(time); | ||
| 65 : | $self->{db}->putKey($Key); | ||
| 66 : | return 1; | ||
| 67 : | } else { | ||
| 68 : | # unexpired but doesn't match -- leave timestamp alone | ||
| 69 : | # we do this to keep an attacker from keeping someone's session | ||
| 70 : | # alive. (yeah, we don't match IPs.) | ||
| 71 : | return 0; | ||
| 72 : | } | ||
| 73 : | } else { | ||
| 74 : | # expired -- delete key | ||
| 75 : | $self->{db}->deleteKey($userID); | ||
| 76 : | return 0; | ||
| 77 : | malsyned | 323 | } |
| 78 : | } | ||
| 79 : | |||
| 80 : | sh002i | 817 | sub unexpiredKeyExists($$) { |
| 81 : | my ($self, $userID) = @_; | ||
| 82 : | sh002i | 1636 | my $Key = $self->{db}->getKey($userID); # checked |
| 83 : | return 0 unless defined $Key; | ||
| 84 : | sh002i | 817 | if (time <= $Key->timestamp()+$self->{ce}->{sessionKeyTimeout}) { |
| 85 : | # unexpired, but leave timestamp alone | ||
| 86 : | return 1; | ||
| 87 : | } else { | ||
| 88 : | # expired -- delete key | ||
| 89 : | $self->{db}->deleteKey($userID); | ||
| 90 : | return 0; | ||
| 91 : | } | ||
| 92 : | } | ||
| 93 : | |||
| 94 : | sh002i | 1683 | sub checkCookie { |
| 95 : | my ($self, $user, $key) = @_; | ||
| 96 : | my $r = $self->{r}; | ||
| 97 : | my %cookies = Apache::Cookie->fetch; | ||
| 98 : | my $cookie = $cookies{WeBWorKAuthentication}; | ||
| 99 : | if ($cookie) { | ||
| 100 : | my ($user, $key) = $cookie->value =~ m/^user=([^&]*)&key=([^&]*)$/; | ||
| 101 : | return $user, $key; | ||
| 102 : | } | ||
| 103 : | } | ||
| 104 : | |||
| 105 : | sub sendCookie { | ||
| 106 : | my ($self, $user, $key) = @_; | ||
| 107 : | my $r = $self->{r}; | ||
| 108 : | my $ce = $self->{ce}; | ||
| 109 : | my $cookie = Apache::Cookie->new($r, | ||
| 110 : | -name => "WeBWorKAuthentication", | ||
| 111 : | -value => "user=$user&key=$key", | ||
| 112 : | -expires => "+30D", | ||
| 113 : | -domain => $r->hostname, | ||
| 114 : | -path => $ce->{webworkURLRoot}, | ||
| 115 : | -secure => 0, | ||
| 116 : | ); | ||
| 117 : | $r->headers_out->set("Set-Cookie" => $cookie->as_string); | ||
| 118 : | } | ||
| 119 : | |||
| 120 : | sh002i | 1685 | sub killCookie { |
| 121 : | my ($self) = @_; | ||
| 122 : | my $r = $self->{r}; | ||
| 123 : | my $ce = $self->{ce}; | ||
| 124 : | my $cookie = Apache::Cookie->new($r, | ||
| 125 : | -name => "WeBWorKAuthentication", | ||
| 126 : | -value => "user=&key=", | ||
| 127 : | -expires => "-1D", | ||
| 128 : | -domain => $r->hostname, | ||
| 129 : | -path => $ce->{webworkURLRoot}, | ||
| 130 : | -secure => 0, | ||
| 131 : | ); | ||
| 132 : | $r->headers_out->set("Set-Cookie" => $cookie->as_string); | ||
| 133 : | } | ||
| 134 : | |||
| 135 : | sh002i | 1682 | # verify will return 1 if the person is who they say the are. If the |
| 136 : | # verification failed because of of invalid authentication data, a note will be | ||
| 137 : | # written in the request explaining why it failed. If the request failed because | ||
| 138 : | # no authentication data was provided, however, no note will be written, as this | ||
| 139 : | # is expected to happen whenever someone types in a URL manually, and is not | ||
| 140 : | # considered an error condition. | ||
| 141 : | malsyned | 305 | sub verify($) { |
| 142 : | my $self = shift; | ||
| 143 : | my $r = $self->{r}; | ||
| 144 : | sh002i | 817 | my $ce = $self->{ce}; |
| 145 : | my $db = $self->{db}; | ||
| 146 : | malsyned | 305 | |
| 147 : | sh002i | 817 | my $practiceUserPrefix = $ce->{practiceUserPrefix}; |
| 148 : | my $debugPracticeUser = $ce->{debugPracticeUser}; | ||
| 149 : | |||
| 150 : | malsyned | 825 | my $force_passwd_authen = $r->param('force_passwd_authen'); |
| 151 : | sh002i | 1684 | my $login_practice_user = $r->param('login_practice_user'); |
| 152 : | my $send_cookie = $r->param("send_cookie"); | ||
| 153 : | sh002i | 1685 | |
| 154 : | malsyned | 441 | my $error; |
| 155 : | sh002i | 817 | my $failWithoutError = 0; |
| 156 : | sh002i | 1685 | my $credentialSource = "params"; |
| 157 : | malsyned | 313 | |
| 158 : | sh002i | 1685 | my $user = $r->param('user'); |
| 159 : | my $passwd = $r->param('passwd'); | ||
| 160 : | my $key = $r->param('key'); | ||
| 161 : | |||
| 162 : | my ($cookieUser, $cookieKey) = $self->checkCookie; | ||
| 163 : | $cookieUser ||= ""; | ||
| 164 : | $cookieKey ||= ""; | ||
| 165 : | |||
| 166 : | sh002i | 817 | VERIFY: { |
| 167 : | # This block is here so we can "last" out of it when we've | ||
| 168 : | # decided whether we're going to succeed or fail. | ||
| 169 : | |||
| 170 : | sh002i | 1684 | if ($login_practice_user) { |
| 171 : | # ignore everything else, find an unused practice user | ||
| 172 : | my $found = 0; | ||
| 173 : | foreach my $userID (sort grep m/^$practiceUserPrefix/, $db->listUsers) { | ||
| 174 : | if (not $self->unexpiredKeyExists($userID)) { | ||
| 175 : | my $Key = $self->generateKey($userID); | ||
| 176 : | $db->addKey($Key); | ||
| 177 : | $r->param("user", $userID); | ||
| 178 : | $r->param("key", $Key->key); | ||
| 179 : | $found = 1; | ||
| 180 : | last; | ||
| 181 : | } | ||
| 182 : | } | ||
| 183 : | unless ($found) { | ||
| 184 : | $error = "No practice users are available. Please try again in a few minutes."; | ||
| 185 : | } | ||
| 186 : | last VERIFY; | ||
| 187 : | } | ||
| 188 : | |||
| 189 : | sh002i | 817 | # no authentication data was given. this is OK. |
| 190 : | unless (defined $user or defined $passwd or defined $key) { | ||
| 191 : | sh002i | 1683 | # check to see if a cookie was sent by the browser. if so, use the |
| 192 : | # user and key from the cookie for authentication. note that the | ||
| 193 : | # cookie is only used if no credentials are sent as parameters. | ||
| 194 : | if ($cookieUser and $cookieKey) { | ||
| 195 : | $user = $cookieUser; | ||
| 196 : | $key = $cookieKey; | ||
| 197 : | sh002i | 1684 | $r->param("user", $user); |
| 198 : | $r->param("key", $key); | ||
| 199 : | sh002i | 1685 | $credentialSource = "cookie"; |
| 200 : | sh002i | 1683 | } else { |
| 201 : | $failWithoutError = 1; | ||
| 202 : | last VERIFY; | ||
| 203 : | } | ||
| 204 : | sh002i | 817 | } |
| 205 : | |||
| 206 : | malsyned | 825 | if (defined $user and $force_passwd_authen) { |
| 207 : | $failWithoutError = 1; | ||
| 208 : | last VERIFY; | ||
| 209 : | } | ||
| 210 : | |||
| 211 : | # no user was supplied. somebody's building their own GET | ||
| 212 : | sh002i | 817 | unless ($user) { |
| 213 : | $error = "You must specify a username."; | ||
| 214 : | last VERIFY; | ||
| 215 : | } | ||
| 216 : | |||
| 217 : | # it's a practice user. | ||
| 218 : | malsyned | 349 | if ($practiceUserPrefix and $user =~ /^$practiceUserPrefix/) { |
| 219 : | sh002i | 817 | # we're not interested in a practice user's password |
| 220 : | $r->param("passwd", ""); | ||
| 221 : | |||
| 222 : | # it's a practice user that doesn't exist. | ||
| 223 : | sh002i | 1636 | unless (defined $db->getUser($user)) { # checked |
| 224 : | sh002i | 817 | $error = "That practice account does not exist."; |
| 225 : | last VERIFY; | ||
| 226 : | } | ||
| 227 : | gage | 1719 | unless ($db->getUser($user)->status eq 'C') { |
| 228 : | $error = "The user $user has been dropped from this course. "; | ||
| 229 : | last VERIFY; | ||
| 230 : | sh002i | 817 | |
| 231 : | gage | 1719 | } |
| 232 : | sh002i | 817 | # we've got a key. |
| 233 : | if ($key) { | ||
| 234 : | if ($self->checkKey($user, $key)) { | ||
| 235 : | # they key was valid. | ||
| 236 : | last VERIFY; | ||
| 237 : | } else { | ||
| 238 : | # the key was invalid. | ||
| 239 : | malsyned | 827 | $error = "Your session has timed out due to inactivity. You must login again."; |
| 240 : | sh002i | 817 | last VERIFY; |
| 241 : | } | ||
| 242 : | } | ||
| 243 : | |||
| 244 : | # -- here we know that a key was not supplied. -- | ||
| 245 : | |||
| 246 : | # it's the debug user. | ||
| 247 : | if ($debugPracticeUser and $user eq $debugPracticeUser) { | ||
| 248 : | # clobber any existing session, valid or not. | ||
| 249 : | my $Key = $self->generateKey($user); | ||
| 250 : | sh002i | 912 | eval { $db->deleteKey($user) }; |
| 251 : | sh002i | 817 | $db->addKey($Key); |
| 252 : | $r->param("key", $Key->key()); | ||
| 253 : | last VERIFY; | ||
| 254 : | } | ||
| 255 : | |||
| 256 : | # an unexpired key exists -- the account is in use. | ||
| 257 : | if ($self->unexpiredKeyExists($user)) { | ||
| 258 : | $error = "That practice account is in use."; | ||
| 259 : | last VERIFY; | ||
| 260 : | } | ||
| 261 : | |||
| 262 : | # here we know the account is not in use, so we | ||
| 263 : | # generate a new session key (unexpiredKeyExists | ||
| 264 : | # deleted any expired key) and succeed! | ||
| 265 : | my $Key = $self->generateKey($user); | ||
| 266 : | $db->addKey($Key); | ||
| 267 : | $r->param("key", $Key->key()); | ||
| 268 : | last VERIFY; | ||
| 269 : | } | ||
| 270 : | |||
| 271 : | # -- here we know it's a regular user. -- | ||
| 272 : | |||
| 273 : | # a key was supplied. | ||
| 274 : | if ($key) { | ||
| 275 : | # we're not interested in a user's password if they're | ||
| 276 : | # supplying a key | ||
| 277 : | $r->param("passwd", ""); | ||
| 278 : | |||
| 279 : | if ($self->checkKey($user, $key)) { | ||
| 280 : | # valid key, so succeed. | ||
| 281 : | last VERIFY; | ||
| 282 : | malsyned | 349 | } else { |
| 283 : | sh002i | 817 | # invalid key. the login page doesn't propogate the key, |
| 284 : | # so we know this is an expired session. | ||
| 285 : | malsyned | 827 | $error = "Your session has timed out due to inactivity. You must login again."; |
| 286 : | sh002i | 817 | last VERIFY; |
| 287 : | malsyned | 349 | } |
| 288 : | } | ||
| 289 : | sh002i | 817 | |
| 290 : | # a password was supplied. | ||
| 291 : | if ($passwd) { | ||
| 292 : | gage | 1719 | # if user has been dropped from the course fail with error message |
| 293 : | unless ($db->getUser($user)->status eq 'C') { | ||
| 294 : | $error = "The user $user has been dropped from this course. Please contact | ||
| 295 : | your instructor if this is an error."; | ||
| 296 : | last VERIFY; | ||
| 297 : | |||
| 298 : | } | ||
| 299 : | sh002i | 817 | if ($self->checkPassword($user, $passwd)) { |
| 300 : | # valid password, so create a new session. (we don't want | ||
| 301 : | # to reuse an old one, duh.) | ||
| 302 : | my $Key = $self->generateKey($user); | ||
| 303 : | sh002i | 912 | eval { $db->deleteKey($user) }; |
| 304 : | sh002i | 817 | $db->addKey($Key); |
| 305 : | $r->param("key", $Key->key()); | ||
| 306 : | # also delete the password | ||
| 307 : | $r->param("passwd", ""); | ||
| 308 : | last VERIFY; | ||
| 309 : | } else { | ||
| 310 : | # incorrect password. fail. | ||
| 311 : | $error = "Incorrect username or password."; | ||
| 312 : | last VERIFY; | ||
| 313 : | } | ||
| 314 : | malsyned | 313 | } |
| 315 : | sh002i | 817 | |
| 316 : | # neither a key or a password were supplied. | ||
| 317 : | $error = "You must enter a password." | ||
| 318 : | } | ||
| 319 : | |||
| 320 : | if (defined $error) { | ||
| 321 : | sh002i | 1685 | # authentication failed, store the error message |
| 322 : | sh002i | 817 | $r->notes("authen_error",$error); |
| 323 : | sh002i | 1685 | |
| 324 : | # if we got a cookie, it probably has incorrect information in it. so | ||
| 325 : | # we want to get rid of it | ||
| 326 : | if ($cookieUser or $cookieKey) { | ||
| 327 : | #warn "fail with error: killing cookie"; | ||
| 328 : | $self->killCookie; | ||
| 329 : | } | ||
| 330 : | |||
| 331 : | sh002i | 817 | return 0; |
| 332 : | sh002i | 1682 | } elsif ($failWithoutError) { |
| 333 : | sh002i | 1685 | # authentication failed, but we don't have any error message to report |
| 334 : | |||
| 335 : | # if we got a cookie, it probably has incorrect information in it. so | ||
| 336 : | # we want to get rid of it | ||
| 337 : | if ($cookieUser or $cookieKey) { | ||
| 338 : | #warn "fail without error: killing cookie"; | ||
| 339 : | $self->killCookie; | ||
| 340 : | } | ||
| 341 : | |||
| 342 : | sh002i | 1682 | return 0; |
| 343 : | malsyned | 313 | } else { |
| 344 : | sh002i | 1682 | # autentication succeeded! |
| 345 : | sh002i | 1685 | |
| 346 : | # we send a cookie if any of these conditions are met: | ||
| 347 : | # (a) a cookie was used for authentication | ||
| 348 : | # (b) a cookie was sent but not used for authentication, and the | ||
| 349 : | # credentials used for authentication were the same as those in | ||
| 350 : | # the cookie | ||
| 351 : | # (c) the user asked to have a cookie sent and is not a guest user. | ||
| 352 : | my $usedCookie = ($credentialSource eq "cookie") || 0; | ||
| 353 : | gage | 1694 | |
| 354 : | my $unusedCookieMatched = (defined($key) and defined($cookieUser) and defined($cookieKey) and | ||
| 355 : | $user eq $cookieUser and $key eq $cookieKey) || 0; | ||
| 356 : | sh002i | 1685 | my $userRequestsCookie = ($send_cookie and not $login_practice_user) || 0; |
| 357 : | #warn "usedCookie=$usedCookie\n"; | ||
| 358 : | #warn "unusedCookieMatched=$unusedCookieMatched\n"; | ||
| 359 : | #warn "userRequestsCookie=$userRequestsCookie\n"; | ||
| 360 : | if ($usedCookie or $unusedCookieMatched or $userRequestsCookie) { | ||
| 361 : | #warn "succeed: sending cookie"; | ||
| 362 : | sh002i | 1683 | $self->sendCookie($r->param("user"), $r->param("key")); |
| 363 : | sh002i | 1685 | } elsif ($cookieUser or $cookieKey) { |
| 364 : | # otherwise, we don't want any bad cookies sticking around | ||
| 365 : | #warn "succeed: killing cookie"; | ||
| 366 : | $self->killCookie; | ||
| 367 : | sh002i | 1683 | } |
| 368 : | sh002i | 1682 | return 1; |
| 369 : | malsyned | 305 | } |
| 370 : | malsyned | 313 | |
| 371 : | # Whatever you do, don't delete this! | ||
| 372 : | critical($r); | ||
| 373 : | sh002i | 1683 | # One time, I deleted it, and my mother broke her back, my cat died, and |
| 374 : | # the Pope got a tummy ache. When I replaced the line, I received eternal | ||
| 375 : | # salvation and a check for USD 500. | ||
| 376 : | malsyned | 305 | } |
| 377 : | |||
| 378 : | 1; | ||
| 379 : | malsyned | 522 | |
| 380 : | __END__ | ||
| 381 : | |||
| 382 : | =head1 AUTHOR | ||
| 383 : | |||
| 384 : | sh002i | 1682 | Written by Dennis Lambe Jr., malsyned (at) math.rochester.edu, and Sam |
| 385 : | Hathaway, sh002i (at) math.rochester.edu. | ||
| 386 : | malsyned | 522 | |
| 387 : | =cut |
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