lib/lib.php

   1 <?php
   2
   3
   4 /*
   5  * TODO's:
   6  * Implement TOTP fully
   7  * Error checking, lots of error checking
   8  * have a way of encapsulating token data stright into a single field so it could be added
   9  *    in some way to a preexisting app without modifying the DB as such... or by just adding
  10  *    a single field to a user table...
  11  * Remove all reliance on the SQLite database. Data should come from the encasultating application
  12  *    which will be expected to provde two function calls where it can get/store data - DONE
  13  */
  14
  15 /*
  16  * The way we should really be doing things is to have an array that encapsulates "normal" data (or a class?)
  17  * and then just manipulate it, then use a checkin function to push the data base into the db...
  18  */
  19
  20 class GoogleAuthenticator {
  21
  22         function __construct() {
  23         }
  24
  25         abstract function getData($username);
  26         abstract function putData($username, $data);
  27         abstract function getUsers();
  28
  29         // a function to create an empty data structure, filled with some defaults
  30         function createEmptyData() {
  31                 $data["tokenkey"] = ""; // the token key
  32                 $data["tokentype"] = "HOTP"; // the token type
  33                 $data["tokentimer"] = 30; // the token timer (For totp) and not supported by ga yet
  34                 $data["tokencounter"] = 1; // the token counter for hotp
  35                 $data["tokenalgorithm"] = "SHA1"; // the token algorithm (not supported by ga yet)
  36
  37                 return $data;
  38         }
  39
  40         // an internal funciton to get
  41         function internalGetData($username) {
  42                 $data = getData($username);
  43                 $deco = unserialize(base64_decode($data));
  44
  45                 if(!$deco) {
  46                         $deco = createEmptyData();
  47                 }
  48
  49                 return $deco;
  50         }
  51
  52
  53         function internalPutData($username, $data) {
  54                 $enco = base64_encode(serialize($data));
  55
  56                 return putData($username, $enco);
  57         }
  58
  59
  60         // set the token type the user it going to use.
  61         // this defaults to HOTP - we only do 30s token
  62         // so lets not be able to set that yet
  63         function setupTokenType($username, $tokentype) {
  64                 if($tokentype!="HOTP" and $tokentype!="TOTP") {
  65                         $errorText = "Invalid Token Type";
  66                         return false;
  67                 }
  68
  69                 $data = internalGetData($username);
  70                 $data["tokentype"] = $tokentype;
  71                 internalPutData($username, $data);
  72
  73                 return true;
  74         }
  75
  76
  77         // create "user" with insert
  78         function setUser($username, $key = "", $ttype="HOTP") {
  79                 if($key == "") $key = $this->createBase32Key();
  80                 $hkey = $this->helperb322hex($key);
  81
  82                 $token = internalGetData($username);
  83                 $token["tokenkey"] = $hkey;
  84                 $token["tokentype"] = $ttype;
  85
  86                 internalPutData($username, $token);
  87                 return $key;
  88         }
  89
  90
  91         // sets the key for a user - this is assuming you dont want
  92         // to use one created by the application. returns false
  93         // if the key is invalid or the user doesn't exist.
  94         function setUserKey($username, $key) {
  95                 // consider scrapping this
  96                 $token = internalGetData($username);
  97                 $token["tokenkey"] = $key;
  98                 internalPutData($username, $token);
  99         }
 100
 101
 102         // have user?
 103         function userExists($username) {
 104                 // need to think about this
 105         }
 106
 107
 108         // self explanitory?
 109         function deleteUser($username) {
 110                 // oh, we need to figure out how to do thi?
 111                 $data = internalGetData($username);
 112                 $data["tokenkey"] = "";
 113                 internalPutData($username);
 114         }
 115
 116         // user has input their user name and some code, authenticate
 117         // it
 118         function authenticateUser($username, $code) {
 119
 120                 $tokendata = internalGetData($username);
 121
 122                 if($tokendata["tokenkey"] == "") {
 123                         $errorText = "No Assigned Token";
 124                         return false;
 125                 }
 126
 127                 // TODO: check return value
 128                 $ttype = $tokendata["tokentype"];
 129                 $tlid = $tokendata["tokencounter"];
 130                 $tkey = $tokendata["tokenkey"];
 131                 switch($ttype) {
 132                         case "HOTP":
 133                                 $st = $tlid;
 134                                 $en = $tlid+20;
 135                                 for($i=$st; $i<$en; $i++) {
 136                                         $stest = $this->oath_hotp($tkey, $i);
 137                                         //error_log("code: $code, $stest, $tkey, $tid");
 138                                         if($code == $stest) {
 139                                                 $tokendata["tokencounter"] = $i;
 140                                                 internalPutData($username, $tokendata);
 141                                                 return true;
 142                                         }
 143                                 }
 144                                 return false;
 145                                 break;
 146                         case "TOTP":
 147                                 $t_now = time();
 148                                 $t_ear = $t_now - 45;
 149                                 $t_lat = $t_now + 60;
 150                                 $t_st = ((int)($t_ear/30));
 151                                 $t_en = ((int)($t_lat/30));
 152                                 //error_log("kmac: $t_now, $t_ear, $t_lat, $t_st, $t_en");
 153                                 for($i=$t_st; $i<=$t_en; $i++) {
 154                                         $stest = $this->oath_hotp($tkey, $i);
 155                                         //error_log("code: $code, $stest, $tkey\n");
 156                                         if($code == $stest) {
 157                                                 return true;
 158                                         }
 159                                 }
 160                                 break;
 161                         default:
 162                                 echo "how the frig did i end up here?";
 163                 }
 164
 165                 return false;
 166
 167         }
 168
 169         // this function allows a user to resync their key. If too
 170         // many codes are called, we only check up to 20 codes in the future
 171         // so if the user is at 21, they'll always fail.
 172         function resyncCode($username, $code1, $code2) {
 173                 // here we'll go from 0 all the way thru to 200k.. if we cant find the code, so be it, they'll need a new one
 174                 // for HOTP tokens we start at x and go to x+20
 175
 176                 // for TOTP we go +/-1min TODO = remember that +/- 1min should
 177                 // be changed based on stepping if we change the expiration time
 178                 // for keys
 179
 180                 //              $this->dbConnector->query('CREATE TABLE "tokens" ("token_id" INTEGER PRIMARY KEY AUTOINCREMENT,"token_key" TEXT NOT NULL, "token_type" TEXT NOT NULL, "token_lastid" INTEGER NOT NULL)');
 181                 $tokendata = internalGetData($username);
 182
 183                 // TODO: check return value
 184                 $ttype = $tokendata["tokentype"];
 185                 $tlid = $tokendata["tokencounter"];
 186                 $tkey = $tokendata["tokenkey"];
 187
 188                 if($tkey == "") {
 189                         $this->errorText = "No Assigned Token";
 190                         return false;
 191                 }
 192
 193                 switch($ttype) {
 194                         case "HOTP":
 195                                 $st = 0;
 196                                 $en = 200000;
 197                                 for($i=$st; $i<$en; $i++) {
 198                                         $stest = $this->oath_hotp($tkey, $i);
 199                                         //echo "code: $code, $stest, $tkey\n";
 200                                         if($code1 == $stest) {
 201                                                 $stest2 = $this->oath_hotp($tkey, $i+1);
 202                                                 if($code2 == $stest2) {
 203                                                         $tokendata["tokencounter"] = $i+1;
 204                                                         internalPutData($username, $tokendata);
 205                                                         return true;
 206                                                 }
 207                                         }
 208                                 }
 209                                 return false;
 210                                 break;
 211                         case "TOTP":
 212                                 break;
 213                         default:
 214                                 echo "how the frig did i end up here?";
 215                 }
 216
 217                 return false;
 218         }
 219
 220         // gets the error text associated with the last error
 221         function getErrorText() {
 222                 return $this->errorText;
 223         }
 224
 225         // create a url compatibile with google authenticator.
 226         function createURL($user, $key,$toktype = "HOTP") {
 227                 // oddity in the google authenticator... hotp needs to be lowercase.
 228                 $toktype = strtolower($toktype);
 229                 if($toktype == "hotp") {
 230                         $url = "otpauth://$toktype/$user?secret=$key&counter=1";
 231                 } else {
 232                         $url = "otpauth://$toktype/$user?secret=$key";
 233                 }
 234                 //echo "url: $url\n";
 235                 return $url;
 236         }
 237
 238         // creeates a base 32 key (random)
 239         function createBase32Key() {
 240                 $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
 241                 $key = "";
 242                 for($i=0; $i<16; $i++) {
 243                         $offset = rand(0,strlen($alphabet)-1);
 244                         //echo "$i off is $offset\n";
 245                         $key .= $alphabet[$offset];
 246                 }
 247
 248                 return $key;
 249         }
 250
 251
 252         function helperb322hex($b32) {
 253         $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
 254
 255         $out = "";
 256         $dous = "";
 257
 258         for($i = 0; $i < strlen($b32); $i++) {
 259                 $in = strrpos($alphabet, $b32[$i]);
 260                 $b = str_pad(base_convert($in, 10, 2), 5, "0", STR_PAD_LEFT);
 261             $out .= $b;
 262             $dous .= $b.".";
 263         }
 264
 265         $ar = str_split($out,20);
 266
 267         //echo "$dous, $b\n";
 268
 269         //print_r($ar);
 270         $out2 = "";
 271         foreach($ar as $val) {
 272                 $rv = str_pad(base_convert($val, 2, 16), 5, "0", STR_PAD_LEFT);
 273                 //echo "rv: $rv from $val\n";
 274                 $out2 .= $rv;
 275
 276         }
 277         //echo "$out2\n";
 278
 279         return $out2;
 280         }
 281
 282         function helperhex2b32($hex) {
 283         $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
 284
 285         $ar = str_split($hex, 5);
 286
 287         $out = "";
 288         foreach($ar as $var) {
 289                 $bc = base_convert($var, 16, 2);
 290                 $bin = str_pad($bc, 20, "0", STR_PAD_LEFT);
 291                 $out .= $bin;
 292                 //echo "$bc was, $var is, $bin are\n";
 293         }
 294
 295         $out2 = "";
 296         $ar2 = str_split($out, 5);
 297         foreach($ar2 as $var2) {
 298                 $bc = base_convert($var2, 2, 10);
 299                 $out2 .= $alphabet[$bc];
 300         }
 301
 302         return $out2;
 303         }
 304
 305         function oath_hotp($key, $counter)
 306         {
 307                 $key = pack("H*", $key);
 308             $cur_counter = array(0,0,0,0,0,0,0,0);
 309             for($i=7;$i>=0;$i--)
 310             {
 311                 $cur_counter[$i] = pack ('C*', $counter);
 312                 $counter = $counter >> 8;
 313             }
 314             $bin_counter = implode($cur_counter);
 315             // Pad to 8 chars
 316             if (strlen ($bin_counter) < 8)
 317             {
 318                 $bin_counter = str_repeat (chr(0), 8 - strlen ($bin_counter)) . $bin_counter;
 319             }
 320
 321             // HMAC
 322             $hash = hash_hmac ('sha1', $bin_counter, $key);
 323             return str_pad($this->oath_truncate($hash), 6, "0", STR_PAD_LEFT);
 324         }
 325
 326         function oath_truncate($hash, $length = 6)
 327         {
 328             // Convert to dec
 329             foreach(str_split($hash,2) as $hex)
 330             {
 331                 $hmac_result[]=hexdec($hex);
 332             }
 333
 334             // Find offset
 335             $offset = $hmac_result[19] & 0xf;
 336
 337             // Algorithm from RFC
 338             return
 339             (
 340                 (($hmac_result[$offset+0] & 0x7f) << 24 ) |
 341                 (($hmac_result[$offset+1] & 0xff) << 16 ) |
 342                 (($hmac_result[$offset+2] & 0xff) << 8 ) |
 343                 ($hmac_result[$offset+3] & 0xff)
 344             ) % pow(10,$length);
 345         }
 346
 347
 348         // some private data bits.
 349         private $getDatafunction;
 350         private $putDatafunction;
 351         private $errorText;
 352 }
 353 ?>