lib/lib.php

   1 <?php
   2
   3 abstract class GoogleAuthenticator {
   4
   5         function __construct() {
   6         }
   7
   8         abstract function getData($username);
   9         abstract function putData($username, $data);
  10         abstract function getUsers();
  11
  12         // a function to create an empty data structure, filled with some defaults
  13         function createEmptyData() {
  14                 $data["tokenkey"] = ""; // the token key
  15                 $data["tokentype"] = "HOTP"; // the token type
  16                 $data["tokentimer"] = 30; // the token timer (For totp) and not supported by ga yet
  17                 $data["tokencounter"] = 1; // the token counter for hotp
  18                 $data["tokenalgorithm"] = "SHA1"; // the token algorithm (not supported by ga yet)
  19
  20                 return $data;
  21         }
  22
  23         // an internal funciton to get
  24         function internalGetData($username) {
  25                 $data = $this->getData($username);
  26                 $deco = unserialize(base64_decode($data));
  27
  28                 if(!$deco) {
  29                         $deco = $this->createEmptyData();
  30                 }
  31
  32                 return $deco;
  33         }
  34
  35
  36         function internalPutData($username, $data) {
  37                 $enco = base64_encode(serialize($data));
  38
  39                 return $this->putData($username, $enco);
  40         }
  41
  42
  43         // set the token type the user it going to use.
  44         // this defaults to HOTP - we only do 30s token
  45         // so lets not be able to set that yet
  46         function setupTokenType($username, $tokentype) {
  47                 if($tokentype!="HOTP" and $tokentype!="TOTP") {
  48                         $errorText = "Invalid Token Type";
  49                         return false;
  50                 }
  51
  52                 $data = $this->internalGetData($username);
  53                 $data["tokentype"] = $tokentype;
  54                 $this->internalPutData($username, $data);
  55
  56                 return true;
  57         }
  58
  59
  60         // create "user" with insert
  61         function setUser($username, $key = "", $ttype="HOTP") {
  62                 if($key == "") $key = $this->createBase32Key();
  63                 $hkey = $this->helperb322hex($key);
  64
  65                 $token = $this->internalGetData($username);
  66                 $token["tokenkey"] = $hkey;
  67                 $token["tokentype"] = $ttype;
  68
  69                 $this->internalPutData($username, $token);
  70                 return $key;
  71         }
  72
  73
  74         function hasToken($username) {
  75                 $token = $this->internalGetData($username);
  76                 // TODO: change this to a pattern match for an actual key
  77                 if(!isset($token["tokenkey"])) return false;
  78                 if($token["tokenkey"] == "") return false;
  79         }
  80
  81
  82         // sets the key for a user - this is assuming you dont want
  83         // to use one created by the application. returns false
  84         // if the key is invalid or the user doesn't exist.
  85         function setUserKey($username, $key) {
  86                 // consider scrapping this
  87                 $token = $this->internalGetData($username);
  88                 $token["tokenkey"] = $key;
  89                 $this->internalPutData($username, $token);
  90         }
  91
  92
  93         // self explanitory?
  94         function deleteUser($username) {
  95                 // oh, we need to figure out how to do thi?
  96                 $data = $this->internalGetData($username);
  97                 $data["tokenkey"] = "";
  98                 $this->internalPutData($username);
  99         }
 100
 101         // user has input their user name and some code, authenticate
 102         // it
 103         function authenticateUser($username, $code) {
 104
 105                 if(preg_match("/[0-9][0-9][0-9][0-9][0-9][0-9]/",$code)<1) return false;
 106                 error_log("begin auth user");
 107                 $tokendata = $this->internalGetData($username);
 108                 $asdf = print_r($tokendata, true);
 109                 error_log("dat is $asdf");
 110
 111                 if($tokendata["tokenkey"] == "") {
 112                         $errorText = "No Assigned Token";
 113                         return false;
 114                 }
 115
 116                 // TODO: check return value
 117                 $ttype = $tokendata["tokentype"];
 118                 $tlid = $tokendata["tokencounter"];
 119                 $tkey = $tokendata["tokenkey"];
 120
 121                 $asdf = print_r($tokendata, true);
 122                 error_log("dat is $asdf");
 123                 switch($ttype) {
 124                         case "HOTP":
 125                                 $st = $tlid;
 126                                 $en = $tlid+20;
 127                                 for($i=$st; $i<$en; $i++) {
 128                                         $stest = $this->oath_hotp($tkey, $i);
 129                                         //error_log("code: $code, $stest, $tkey, $tid");
 130                                         if($code == $stest) {
 131                                                 $tokendata["tokencounter"] = $i;
 132                                                 $this->internalPutData($username, $tokendata);
 133                                                 return true;
 134                                         }
 135                                 }
 136                                 return false;
 137                                 break;
 138                         case "TOTP":
 139                                 $t_now = time();
 140                                 $t_ear = $t_now - 45;
 141                                 $t_lat = $t_now + 60;
 142                                 $t_st = ((int)($t_ear/30));
 143                                 $t_en = ((int)($t_lat/30));
 144                                 //error_log("kmac: $t_now, $t_ear, $t_lat, $t_st, $t_en");
 145                                 for($i=$t_st; $i<=$t_en; $i++) {
 146                                         $stest = $this->oath_hotp($tkey, $i);
 147                                         //error_log("code: $code, $stest, $tkey\n");
 148                                         if($code == $stest) {
 149                                                 return true;
 150                                         }
 151                                 }
 152                                 break;
 153                         default:
 154                                 echo "how the frig did i end up here?";
 155                 }
 156
 157                 return false;
 158
 159         }
 160
 161         // this function allows a user to resync their key. If too
 162         // many codes are called, we only check up to 20 codes in the future
 163         // so if the user is at 21, they'll always fail.
 164         function resyncCode($username, $code1, $code2) {
 165                 // 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
 166                 // for HOTP tokens we start at x and go to x+20
 167
 168                 // for TOTP we go +/-1min TODO = remember that +/- 1min should
 169                 // be changed based on stepping if we change the expiration time
 170                 // for keys
 171
 172                 //              $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)');
 173                 $tokendata = internalGetData($username);
 174
 175                 // TODO: check return value
 176                 $ttype = $tokendata["tokentype"];
 177                 $tlid = $tokendata["tokencounter"];
 178                 $tkey = $tokendata["tokenkey"];
 179
 180                 if($tkey == "") {
 181                         $this->errorText = "No Assigned Token";
 182                         return false;
 183                 }
 184
 185                 switch($ttype) {
 186                         case "HOTP":
 187                                 $st = 0;
 188                                 $en = 200000;
 189                                 for($i=$st; $i<$en; $i++) {
 190                                         $stest = $this->oath_hotp($tkey, $i);
 191                                         //echo "code: $code, $stest, $tkey\n";
 192                                         if($code1 == $stest) {
 193                                                 $stest2 = $this->oath_hotp($tkey, $i+1);
 194                                                 if($code2 == $stest2) {
 195                                                         $tokendata["tokencounter"] = $i+1;
 196                                                         internalPutData($username, $tokendata);
 197                                                         return true;
 198                                                 }
 199                                         }
 200                                 }
 201                                 return false;
 202                                 break;
 203                         case "TOTP":
 204                                 break;
 205                         default:
 206                                 echo "how the frig did i end up here?";
 207                 }
 208
 209                 return false;
 210         }
 211
 212         // gets the error text associated with the last error
 213         function getErrorText() {
 214                 return $this->errorText;
 215         }
 216
 217         // create a url compatibile with google authenticator.
 218         function createURL($user) {
 219                 // oddity in the google authenticator... hotp needs to be lowercase.
 220                 $data = $this->internalGetData($user);
 221                 $toktype = $data["tokentype"];
 222                 $key = $data["tokenkey"];
 223                 $toktype = strtolower($toktype);
 224                 if($toktype == "hotp") {
 225                         $url = "otpauth://$toktype/$user?secret=$key&counter=1";
 226                 } else {
 227                         $url = "otpauth://$toktype/$user?secret=$key";
 228                 }
 229                 //echo "url: $url\n";
 230                 return $url;
 231         }
 232
 233         // creeates a base 32 key (random)
 234         function createBase32Key() {
 235                 $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
 236                 $key = "";
 237                 for($i=0; $i<16; $i++) {
 238                         $offset = rand(0,strlen($alphabet)-1);
 239                         //echo "$i off is $offset\n";
 240                         $key .= $alphabet[$offset];
 241                 }
 242
 243                 return $key;
 244         }
 245
 246
 247         function helperb322hex($b32) {
 248         $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
 249
 250         $out = "";
 251         $dous = "";
 252
 253         for($i = 0; $i < strlen($b32); $i++) {
 254                 $in = strrpos($alphabet, $b32[$i]);
 255                 $b = str_pad(base_convert($in, 10, 2), 5, "0", STR_PAD_LEFT);
 256             $out .= $b;
 257             $dous .= $b.".";
 258         }
 259
 260         $ar = str_split($out,20);
 261
 262         //echo "$dous, $b\n";
 263
 264         //print_r($ar);
 265         $out2 = "";
 266         foreach($ar as $val) {
 267                 $rv = str_pad(base_convert($val, 2, 16), 5, "0", STR_PAD_LEFT);
 268                 //echo "rv: $rv from $val\n";
 269                 $out2 .= $rv;
 270
 271         }
 272         //echo "$out2\n";
 273
 274         return $out2;
 275         }
 276
 277         function helperhex2b32($hex) {
 278         $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
 279
 280         $ar = str_split($hex, 5);
 281
 282         $out = "";
 283         foreach($ar as $var) {
 284                 $bc = base_convert($var, 16, 2);
 285                 $bin = str_pad($bc, 20, "0", STR_PAD_LEFT);
 286                 $out .= $bin;
 287                 //echo "$bc was, $var is, $bin are\n";
 288         }
 289
 290         $out2 = "";
 291         $ar2 = str_split($out, 5);
 292         foreach($ar2 as $var2) {
 293                 $bc = base_convert($var2, 2, 10);
 294                 $out2 .= $alphabet[$bc];
 295         }
 296
 297         return $out2;
 298         }
 299
 300         function oath_hotp($key, $counter)
 301         {
 302                 $key = pack("H*", $key);
 303             $cur_counter = array(0,0,0,0,0,0,0,0);
 304             for($i=7;$i>=0;$i--)
 305             {
 306                 $cur_counter[$i] = pack ('C*', $counter);
 307                 $counter = $counter >> 8;
 308             }
 309             $bin_counter = implode($cur_counter);
 310             // Pad to 8 chars
 311             if (strlen ($bin_counter) < 8)
 312             {
 313                 $bin_counter = str_repeat (chr(0), 8 - strlen ($bin_counter)) . $bin_counter;
 314             }
 315
 316             // HMAC
 317             $hash = hash_hmac ('sha1', $bin_counter, $key);
 318             return str_pad($this->oath_truncate($hash), 6, "0", STR_PAD_LEFT);
 319         }
 320
 321         function oath_truncate($hash, $length = 6)
 322         {
 323             // Convert to dec
 324             foreach(str_split($hash,2) as $hex)
 325             {
 326                 $hmac_result[]=hexdec($hex);
 327             }
 328
 329             // Find offset
 330             $offset = $hmac_result[19] & 0xf;
 331
 332             // Algorithm from RFC
 333             return
 334             (
 335                 (($hmac_result[$offset+0] & 0x7f) << 24 ) |
 336                 (($hmac_result[$offset+1] & 0xff) << 16 ) |
 337                 (($hmac_result[$offset+2] & 0xff) << 8 ) |
 338                 ($hmac_result[$offset+3] & 0xff)
 339             ) % pow(10,$length);
 340         }
 341
 342
 343         // some private data bits.
 344         private $getDatafunction;
 345         private $putDatafunction;
 346         private $errorText;
 347         private $errorCode;
 348
 349         /*
 350          * error codes
 351          * 1: Auth Failed
 352          * 2: No Key
 353          * 3: input code was invalid (user input an invalid code - must be 6 numerical digits)
 354          * 4: user doesnt exist?
 355          * 5: key invalid
 356          */
 357 }
 358 ?>