includes/functions-auth.php

   1 <?php
   2 /**
   3  * Check for valid user via login form or stored cookie. Returns true or an error message
   4  *
   5  */
   6 function yourls_is_valid_user() {
   7         static $valid = false;
   8
   9         if( $valid )
  10                 return true;
  11
  12         // Allow plugins to short-circuit the whole function
  13         $pre = yourls_apply_filter( 'shunt_is_valid_user', null );
  14         if ( null !== $pre ) {
  15                 $valid = ( $pre === true ) ;
  16                 return $pre;
  17         }
  18
  19         // $unfiltered_valid : are credentials valid? Boolean value. It's "unfiltered" to allow plugins to eventually filter it.
  20         $unfiltered_valid = false;
  21
  22         // Logout request
  23         if( isset( $_GET['action'] ) && $_GET['action'] == 'logout' ) {
  24                 yourls_do_action( 'logout' );
  25                 yourls_store_cookie( null );
  26                 return yourls__( 'Logged out successfully' );
  27         }
  28
  29         // Check cookies or login request. Login form has precedence.
  30
  31         yourls_do_action( 'pre_login' );
  32
  33         // Determine auth method and check credentials
  34         if
  35                 // API only: Secure (no login or pwd) and time limited token
  36                 // ?timestamp=12345678&signature=md5(totoblah12345678)
  37                 ( yourls_is_API() &&
  38                   isset( $_REQUEST['timestamp'] ) && !empty($_REQUEST['timestamp'] ) &&
  39                   isset( $_REQUEST['signature'] ) && !empty($_REQUEST['signature'] )
  40                 )
  41                 {
  42                         yourls_do_action( 'pre_login_signature_timestamp' );
  43                         $unfiltered_valid = yourls_check_signature_timestamp();
  44                 }
  45
  46         elseif
  47                 // API only: Secure (no login or pwd)
  48                 // ?signature=md5(totoblah)
  49                 ( yourls_is_API() &&
  50                   !isset( $_REQUEST['timestamp'] ) &&
  51                   isset( $_REQUEST['signature'] ) && !empty( $_REQUEST['signature'] )
  52                 )
  53                 {
  54                         yourls_do_action( 'pre_login_signature' );
  55                         $unfiltered_valid = yourls_check_signature();
  56                 }
  57
  58         elseif
  59                 // API or normal: login with username & pwd
  60                 ( isset( $_REQUEST['username'] ) && isset( $_REQUEST['password'] )
  61                   && !empty( $_REQUEST['username'] ) && !empty( $_REQUEST['password']  ) )
  62                 {
  63                         yourls_do_action( 'pre_login_username_password' );
  64                         $unfiltered_valid = yourls_check_username_password();
  65                 }
  66
  67         elseif
  68                 // Normal only: cookies
  69                 ( !yourls_is_API() &&
  70                   isset( $_COOKIE['yourls_username'] ) )
  71                 {
  72                         yourls_do_action( 'pre_login_cookie' );
  73                         $unfiltered_valid = yourls_check_auth_cookie();
  74                 }
  75
  76         // Regardless of validity, allow plugins to filter the boolean and have final word
  77         $valid = yourls_apply_filter( 'is_valid_user', $unfiltered_valid );
  78
  79         // Login for the win!
  80         if ( $valid ) {
  81                 yourls_do_action( 'login' );
  82
  83                 // (Re)store encrypted cookie if needed
  84                 if ( !yourls_is_API() ) {
  85                         yourls_store_cookie( YOURLS_USER );
  86
  87                         // Login form : redirect to requested URL to avoid re-submitting the login form on page reload
  88                         if( isset( $_REQUEST['username'] ) && isset( $_REQUEST['password'] ) ) {
  89                                 $url = $_SERVER['REQUEST_URI'];
  90                                 yourls_redirect( $url );
  91                         }
  92                 }
  93
  94                 // Login successful
  95                 return true;
  96         }
  97
  98         // Login failed
  99         yourls_do_action( 'login_failed' );
 100
 101         if ( isset( $_REQUEST['username'] ) || isset( $_REQUEST['password'] ) ) {
 102                 return yourls__( 'Invalid username or password' );
 103         } else {
 104                 return yourls__( 'Please log in' );
 105         }
 106 }
 107
 108 /**
 109  * Check auth against list of login=>pwd. Sets user if applicable, returns bool
 110  *
 111  */
 112 function yourls_check_username_password() {
 113         global $yourls_user_passwords;
 114         if( isset( $yourls_user_passwords[ $_REQUEST['username'] ] ) && yourls_check_password_hash( $_REQUEST['username'], $_REQUEST['password'] ) ) {
 115                 yourls_set_user( $_REQUEST['username'] );
 116                 return true;
 117         }
 118         return false;
 119 }
 120
 121 /**
 122  * Check a submitted password sent in plain text against stored password which can be a salted hash
 123  *
 124  */
 125 function yourls_check_password_hash( $user, $submitted_password ) {
 126         global $yourls_user_passwords;
 127
 128         if( !isset( $yourls_user_passwords[ $user ] ) )
 129                 return false;
 130
 131         if ( yourls_has_phpass_password( $user ) ) {
 132                 // Stored password is hashed with phpass
 133                 $hasher = new PasswordHash( 8, false );
 134                 list( , $hash ) = explode( ':', $yourls_user_passwords[ $user ] );
 135                 $hash = str_replace( '!', '$', $hash );
 136                 return ( $hasher->CheckPassword( $submitted_password, $hash ) );
 137         } else if( yourls_has_md5_password( $user ) ) {
 138                 // Stored password is a salted md5 hash: "md5:<$r = rand(10000,99999)>:<md5($r.'thepassword')>"
 139                 list( , $salt, ) = explode( ':', $yourls_user_passwords[ $user ] );
 140                 return( $yourls_user_passwords[ $user ] == 'md5:'.$salt.':'.md5( $salt . $submitted_password ) );
 141         } else {
 142                 // Password stored in clear text
 143                 return( $yourls_user_passwords[ $user ] == $submitted_password );
 144         }
 145 }
 146
 147 /**
 148  * Overwrite plaintext passwords in config file with phpassed versions.
 149  *
 150  * @since 1.7
 151  * @return true if overwrite was successful, an error message otherwise
 152  */
 153 function yourls_hash_passwords_now() {
 154         global $yourls_user_passwords;
 155
 156         $configdata = file_get_contents( YOURLS_CONFIGFILE );
 157         if( $configdata == false )
 158                 return 'could not read file';
 159
 160         $to_hash = 0; // keep track of number of passwords that need hashing
 161         $hasher  = new PasswordHash( 8, false );
 162
 163         // TODO: check mode for writability
 164         foreach ( $yourls_user_passwords as $user => $password ) {
 165                 if ( !yourls_has_phpass_password( $user ) && !yourls_has_md5_password( $user ) ) {
 166                         $to_hash++;
 167                         $hash = $hasher->HashPassword( $password );
 168                         // PHP would interpret $ as a variable, so replace it in storage.
 169                         $hash = str_replace( '$', '!', $hash );
 170                         $quotes = "'" . '"';
 171                         $pattern = "/[$quotes]${user}[$quotes]\s*=>\s*[$quotes]" . preg_quote( $password, '-' ) . "[$quotes]/";
 172                         $replace = "'$user' => 'phpass:$hash' /* Password encrypted by YOURLS */ ";
 173                         $count = 0;
 174                         $configdata = preg_replace( $pattern, $replace, $configdata, -1, $count );
 175                         // There should be exactly one replacement. Otherwise, fast fail.
 176                         if ( $count != 1 ) {
 177                                 global $ydb;
 178                                 $ydb->debug_log[] = "Problem with preg_replace for password hash of user $user";
 179                                 return 'preg_replace problem';
 180                         }
 181                 }
 182         }
 183
 184         if( $to_hash == 0 )
 185                 return true; // There was no password to encrypt
 186
 187         $success = file_put_contents( YOURLS_CONFIGFILE, $configdata );
 188         if ( $success === FALSE ) {
 189                 global $ydb;
 190                 $ydb->debug_log[] = "Failed writing to " . YOURLS_CONFIGFILE;
 191                 return 'could not write file';
 192         }
 193         return true;
 194 }
 195
 196 /**
 197  * Check to see if any passwords are stored as cleartext.
 198  *
 199  * @since 1.7
 200  * @return bool true if any passwords are cleartext
 201  */
 202 function yourls_has_cleartext_passwords() {
 203         global $yourls_user_passwords;
 204         foreach ( $yourls_user_passwords as $user => $pwdata ) {
 205                 if ( !yourls_has_md5_password( $user ) && !yourls_has_phpass_password( $user ) ) {
 206                         return true;
 207                 }
 208         }
 209         return false;
 210 }
 211
 212 /**
 213  * Check if a user has a hashed password
 214  *
 215  * Check if a user password is 'md5:[38 chars]'. TODO: deprecate this when/if we have proper user management with
 216  * password hashes stored in the DB
 217  *
 218  * @since 1.7
 219  * @param string $user user login
 220  * @return bool true if password hashed, false otherwise
 221  */
 222 function yourls_has_md5_password( $user ) {
 223         global $yourls_user_passwords;
 224         return(    isset( $yourls_user_passwords[ $user ] )
 225                 && substr( $yourls_user_passwords[ $user ], 0, 4 ) == 'md5:'
 226                     && strlen( $yourls_user_passwords[ $user ] ) == 42 // http://www.google.com/search?q=the+answer+to+life+the+universe+and+everything
 227                    );
 228 }
 229
 230 /**
 231  * Check if a user's password is hashed with PHPASS.
 232  *
 233  * @since 1.7
 234  * @param string $user user login
 235  * @return bool true if password hashed with PHPASS, otherwise false
 236  */
 237 function yourls_has_phpass_password( $user ) {
 238         global $yourls_user_passwords;
 239         return( isset( $yourls_user_passwords[ $user ] )
 240                 && substr( $yourls_user_passwords[ $user ], 0, 7 ) == 'phpass:'
 241         );
 242 }
 243
 244 /**
 245  * Check auth against encrypted COOKIE data. Sets user if applicable, returns bool
 246  *
 247  */
 248 function yourls_check_auth_cookie() {
 249         global $yourls_user_passwords;
 250         foreach( $yourls_user_passwords as $valid_user => $valid_password ) {
 251                 if ( yourls_salt( $valid_user ) == $_COOKIE['yourls_username'] ) {
 252                         yourls_set_user( $valid_user );
 253                         return true;
 254                 }
 255         }
 256         return false;
 257 }
 258
 259 /**
 260  * Check auth against signature and timestamp. Sets user if applicable, returns bool
 261  *
 262  */
 263 function yourls_check_signature_timestamp() {
 264         // Timestamp in PHP : time()
 265         // Timestamp in JS: parseInt(new Date().getTime() / 1000)
 266         global $yourls_user_passwords;
 267         foreach( $yourls_user_passwords as $valid_user => $valid_password ) {
 268                 if (
 269                         (
 270                                 md5( $_REQUEST['timestamp'].yourls_auth_signature( $valid_user ) ) == $_REQUEST['signature']
 271                                 or
 272                                 md5( yourls_auth_signature( $valid_user ).$_REQUEST['timestamp'] ) == $_REQUEST['signature']
 273                         )
 274                         &&
 275                         yourls_check_timestamp( $_REQUEST['timestamp'] )
 276                         ) {
 277                         yourls_set_user( $valid_user );
 278                         return true;
 279                 }
 280         }
 281         return false;
 282 }
 283
 284 /**
 285  * Check auth against signature. Sets user if applicable, returns bool
 286  *
 287  */
 288 function yourls_check_signature() {
 289         global $yourls_user_passwords;
 290         foreach( $yourls_user_passwords as $valid_user => $valid_password ) {
 291                 if ( yourls_auth_signature( $valid_user ) == $_REQUEST['signature'] ) {
 292                         yourls_set_user( $valid_user );
 293                         return true;
 294                 }
 295         }
 296         return false;
 297 }
 298
 299 /**
 300  * Generate secret signature hash
 301  *
 302  */
 303 function yourls_auth_signature( $username = false ) {
 304         if( !$username && defined('YOURLS_USER') ) {
 305                 $username = YOURLS_USER;
 306         }
 307         return ( $username ? substr( yourls_salt( $username ), 0, 10 ) : 'Cannot generate auth signature: no username' );
 308 }
 309
 310 /**
 311  * Check if timestamp is not too old
 312  *
 313  */
 314 function yourls_check_timestamp( $time ) {
 315         $now = time();
 316         // Allow timestamp to be a little in the future or the past -- see Issue 766
 317         return yourls_apply_filter( 'check_timestamp', abs( $now - $time ) < YOURLS_NONCE_LIFE, $time );
 318 }
 319
 320 /**
 321  * Store new cookie. No $user will delete the cookie.
 322  *
 323  */
 324 function yourls_store_cookie( $user = null ) {
 325         if( !$user ) {
 326                 $pass = null;
 327                 $time = time() - 3600;
 328         } else {
 329                 global $yourls_user_passwords;
 330                 if( isset($yourls_user_passwords[$user]) ) {
 331                         $pass = $yourls_user_passwords[$user];
 332                 } else {
 333                         die( 'Stealing cookies?' ); // This should never happen
 334                 }
 335                 $time = time() + YOURLS_COOKIE_LIFE;
 336         }
 337
 338         $domain   = yourls_apply_filter( 'setcookie_domain',   parse_url( YOURLS_SITE, 1 ) );
 339         $secure   = yourls_apply_filter( 'setcookie_secure',   yourls_is_ssl() );
 340         $httponly = yourls_apply_filter( 'setcookie_httponly', true );
 341
 342         if ( !headers_sent() ) {
 343                 // Set httponly if the php version is >= 5.2.0
 344                 if( version_compare( phpversion(), '5.2.0', 'ge' ) ) {
 345                         setcookie('yourls_username', yourls_salt( $user ), $time, '/', $domain, $secure, $httponly );
 346                 } else {
 347                         setcookie('yourls_username', yourls_salt( $user ), $time, '/', $domain, $secure );
 348                 }
 349         } else {
 350                 // For some reason cookies were not stored: action to be able to debug that
 351                 yourls_do_action( 'setcookie_failed', $user );
 352         }
 353 }
 354
 355 /**
 356  * Set user name
 357  *
 358  */
 359 function yourls_set_user( $user ) {
 360         if( !defined( 'YOURLS_USER' ) )
 361                 define( 'YOURLS_USER', $user );
 362 }
 363