<?php
+abstract class GoogleAuthenticator {
+
+ function __construct() {
+ }
+
+ abstract function getData($username);
+ abstract function putData($username, $data);
+ abstract function getUsers();
+
+ // a function to create an empty data structure, filled with some defaults
+ function createEmptyData() {
+ $data["tokenkey"] = ""; // the token key
+ $data["tokentype"] = "HOTP"; // the token type
+ $data["tokentimer"] = 30; // the token timer (For totp) and not supported by ga yet
+ $data["tokencounter"] = 1; // the token counter for hotp
+ $data["tokenalgorithm"] = "SHA1"; // the token algorithm (not supported by ga yet)
+
+ return $data;
+ }
+
+ // an internal funciton to get
+ function internalGetData($username) {
+ $data = $this->getData($username);
+ $deco = unserialize(base64_decode($data));
+
+ if(!$deco) {
+ $deco = $this->createEmptyData();
+ }
+
+ return $deco;
+ }
+
+ function internalPutData($username, $data) {
+ $enco = base64_encode(serialize($data));
+
+ return $this->putData($username, $enco);
+ }
+
+
+ // set the token type the user it going to use.
+ // this defaults to HOTP - we only do 30s token
+ // so lets not be able to set that yet
+ function setupTokenType($username, $tokentype) {
+ if($tokentype!="HOTP" and $tokentype!="TOTP") {
+ $errorText = "Invalid Token Type";
+ return false;
+ }
+
+ $data = $this->internalGetData($username);
+ $data["tokentype"] = $tokentype;
+ $this->internalPutData($username, $data);
+
+ return true;
+ }
+
+
+ // create "user" with insert
+ function setUser($username, $ttype="HOTP", $key = "") {
+ if($key == "") $key = $this->createBase32Key();
+ $hkey = $this->helperb322hex($key);
+
+ $token = $this->internalGetData($username);
+ $token["tokenkey"] = $hkey;
+ $token["tokentype"] = $ttype;
+
+ $this->internalPutData($username, $token);
+ return $key;
+ }
+
+
+ function hasToken($username) {
+ $token = $this->internalGetData($username);
+ // TODO: change this to a pattern match for an actual key
+ if(!isset($token["tokenkey"])) return false;
+ if($token["tokenkey"] == "") return false;
+ return true;
+ }
+
+
+ // sets the key for a user - this is assuming you dont want
+ // to use one created by the application. returns false
+ // if the key is invalid or the user doesn't exist.
+ function setUserKey($username, $key) {
+ // consider scrapping this
+ $token = $this->internalGetData($username);
+ $token["tokenkey"] = $key;
+ $this->internalPutData($username, $token);
+ }
+
+
+ // self explanitory?
+ function deleteUser($username) {
+ // oh, we need to figure out how to do thi?
+ $data = $this->internalGetData($username);
+ $data["tokenkey"] = "";
+ $this->internalPutData($username);
+ }
+
+ // user has input their user name and some code, authenticate
+ // it
+ function authenticateUser($username, $code) {
+
+ if(preg_match("/[0-9][0-9][0-9][0-9][0-9][0-9]/",$code)<1) return false;
+ error_log("begin auth user");
+ $tokendata = $this->internalGetData($username);
+ $asdf = print_r($tokendata, true);
+ error_log("dat is $asdf");
+
+ if($tokendata["tokenkey"] == "") {
+ $errorText = "No Assigned Token";
+ return false;
+ }
+
+ // TODO: check return value
+ $ttype = $tokendata["tokentype"];
+ $tlid = $tokendata["tokencounter"];
+ $tkey = $tokendata["tokenkey"];
+
+ $asdf = print_r($tokendata, true);
+ error_log("dat is $asdf");
+ switch($ttype) {
+ case "HOTP":
+ $st = $tlid;
+ $en = $tlid+20;
+ for($i=$st; $i<$en; $i++) {
+ $stest = $this->oath_hotp($tkey, $i);
+ //error_log("code: $code, $stest, $tkey, $tid");
+ if($code == $stest) {
+ $tokendata["tokencounter"] = $i;
+ $this->internalPutData($username, $tokendata);
+ return true;
+ }
+ }
+ return false;
+ break;
+ case "TOTP":
+ $t_now = time();
+ $t_ear = $t_now - 45;
+ $t_lat = $t_now + 60;
+ $t_st = ((int)($t_ear/30));
+ $t_en = ((int)($t_lat/30));
+ //error_log("kmac: $t_now, $t_ear, $t_lat, $t_st, $t_en");
+ for($i=$t_st; $i<=$t_en; $i++) {
+ $stest = $this->oath_hotp($tkey, $i);
+ //error_log("code: $code, $stest, $tkey\n");
+ if($code == $stest) {
+ return true;
+ }
+ }
+ break;
+ default:
+ echo "how the frig did i end up here?";
+ }
+
+ return false;
+
+ }
+
+ // this function allows a user to resync their key. If too
+ // many codes are called, we only check up to 20 codes in the future
+ // so if the user is at 21, they'll always fail.
+ function resyncCode($username, $code1, $code2) {
+ // 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
+ // for HOTP tokens we start at x and go to x+20
+
+ // for TOTP we go +/-1min TODO = remember that +/- 1min should
+ // be changed based on stepping if we change the expiration time
+ // for keys
+
+ // $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)');
+ $tokendata = internalGetData($username);
+
+ // TODO: check return value
+ $ttype = $tokendata["tokentype"];
+ $tlid = $tokendata["tokencounter"];
+ $tkey = $tokendata["tokenkey"];
+
+ if($tkey == "") {
+ $this->errorText = "No Assigned Token";
+ return false;
+ }
+
+ switch($ttype) {
+ case "HOTP":
+ $st = 0;
+ $en = 200000;
+ for($i=$st; $i<$en; $i++) {
+ $stest = $this->oath_hotp($tkey, $i);
+ //echo "code: $code, $stest, $tkey\n";
+ if($code1 == $stest) {
+ $stest2 = $this->oath_hotp($tkey, $i+1);
+ if($code2 == $stest2) {
+ $tokendata["tokencounter"] = $i+1;
+ internalPutData($username, $tokendata);
+ return true;
+ }
+ }
+ }
+ return false;
+ break;
+ case "TOTP":
+ break;
+ default:
+ echo "how the frig did i end up here?";
+ }
+
+ return false;
+ }
+
+ // gets the error text associated with the last error
+ function getErrorText() {
+ return $this->errorText;
+ }
+
+ // create a url compatibile with google authenticator.
+ function createURL($user) {
+ // oddity in the google authenticator... hotp needs to be lowercase.
+ $data = $this->internalGetData($user);
+ $toktype = $data["tokentype"];
+ $key = $this->helperhex2b32($data["tokenkey"]);
+ $toktype = strtolower($toktype);
+ if($toktype == "hotp") {
+ $url = "otpauth://$toktype/$user?secret=$key&counter=1";
+ } else {
+ $url = "otpauth://$toktype/$user?secret=$key";
+ }
+ //echo "url: $url\n";
+ return $url;
+ }
+
+ // creeates a base 32 key (random)
+ function createBase32Key() {
+ $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+ $key = "";
+ for($i=0; $i<16; $i++) {
+ $offset = rand(0,strlen($alphabet)-1);
+ //echo "$i off is $offset\n";
+ $key .= $alphabet[$offset];
+ }
+
+ return $key;
+ }
+
+ // returns a hex key
+ function getKey($username) {
+ $data = $this->internalGetData($username);
+ $key = $data["tokenkey"];
+
+ return $key;
+ }
+
+ // get key type
+ function getTokenType($username) {
+ $data = $this->internalGetData($username);
+ $toktype = $data["tokentype"];
+
+ return $toktype;
+ }
+
+
+ function helperb322hex($b32) {
+ $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+ $out = "";
+ $dous = "";
+
+ for($i = 0; $i < strlen($b32); $i++) {
+ $in = strrpos($alphabet, $b32[$i]);
+ $b = str_pad(base_convert($in, 10, 2), 5, "0", STR_PAD_LEFT);
+ $out .= $b;
+ $dous .= $b.".";
+ }
+
+ $ar = str_split($out,20);
+
+ //echo "$dous, $b\n";
+
+ //print_r($ar);
+ $out2 = "";
+ foreach($ar as $val) {
+ $rv = str_pad(base_convert($val, 2, 16), 5, "0", STR_PAD_LEFT);
+ //echo "rv: $rv from $val\n";
+ $out2 .= $rv;
+
+ }
+ //echo "$out2\n";
+
+ return $out2;
+ }
+
+ function helperhex2b32($hex) {
+ $alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+ $ar = str_split($hex, 5);
+
+ $out = "";
+ foreach($ar as $var) {
+ $bc = base_convert($var, 16, 2);
+ $bin = str_pad($bc, 20, "0", STR_PAD_LEFT);
+ $out .= $bin;
+ //echo "$bc was, $var is, $bin are\n";
+ }
+
+ $out2 = "";
+ $ar2 = str_split($out, 5);
+ foreach($ar2 as $var2) {
+ $bc = base_convert($var2, 2, 10);
+ $out2 .= $alphabet[$bc];
+ }
+
+ return $out2;
+ }
+
+ function oath_hotp($key, $counter)
+ {
+ $key = pack("H*", $key);
+ $cur_counter = array(0,0,0,0,0,0,0,0);
+ for($i=7;$i>=0;$i--)
+ {
+ $cur_counter[$i] = pack ('C*', $counter);
+ $counter = $counter >> 8;
+ }
+ $bin_counter = implode($cur_counter);
+ // Pad to 8 chars
+ if (strlen ($bin_counter) < 8)
+ {
+ $bin_counter = str_repeat (chr(0), 8 - strlen ($bin_counter)) . $bin_counter;
+ }
+
+ // HMAC
+ $hash = hash_hmac ('sha1', $bin_counter, $key);
+ return str_pad($this->oath_truncate($hash), 6, "0", STR_PAD_LEFT);
+ }
+
+ function oath_truncate($hash, $length = 6)
+ {
+ // Convert to dec
+ foreach(str_split($hash,2) as $hex)
+ {
+ $hmac_result[]=hexdec($hex);
+ }
+
+ // Find offset
+ $offset = $hmac_result[19] & 0xf;
+
+ // Algorithm from RFC
+ return
+ (
+ (($hmac_result[$offset+0] & 0x7f) << 24 ) |
+ (($hmac_result[$offset+1] & 0xff) << 16 ) |
+ (($hmac_result[$offset+2] & 0xff) << 8 ) |
+ ($hmac_result[$offset+3] & 0xff)
+ ) % pow(10,$length);
+ }
+
+
+ // some private data bits.
+ private $getDatafunction;
+ private $putDatafunction;
+ private $errorText;
+ private $errorCode;
+
+ /*
+ * error codes
+ * 1: Auth Failed
+ * 2: No Key
+ * 3: input code was invalid (user input an invalid code - must be 6 numerical digits)
+ * 4: user doesnt exist?
+ * 5: key invalid
+ */
+}
?>
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