SecretKey: $secretkey
";
$key = base32static::decode($secretkey);
print "Key(base 32 decode): $key
";
$unixtimestamp = time()/30;
print "UnixTimeStamp (time()/30): $unixtimestamp
";
for($i=-($rangein30s); $i<=$rangein30s; $i++) {
$checktime = (int)($unixtimestamp+$i);
print "Calculating oath_hotp from (int)(unixtimestamp +- 30sec offset): $checktime basing on secret key
";
$thiskey = self::oath_hotp($key, $checktime, true);
print "======================================================
";
print "CheckTime: $checktime oath_hotp:".$thiskey."
";
$result = $result." # ".self::oath_truncate($thiskey, 6, true);
}
return $result;
}
public static function getBarCodeUrl($username, $domain, $secretkey, $issuer) {
$url = "https://chart.apis.google.com/chart";
$url = $url."?chs=200x200&chld=M|0&cht=qr&chl=otpauth://totp/";
$url = $url.$username . "@" . $domain . "%3Fsecret%3D" . $secretkey . '%26issuer%3D' . rawurlencode($issuer);
return $url;
}
private static function oath_hotp ($key, $counter, $debug=false) {
$result = "";
$orgcounter = $counter;
$cur_counter = array(0,0,0,0,0,0,0,0);
if ($debug) {
print "Packing counter $counter (".dechex($counter).")into binary string - pay attention to hex representation of key and binary representation
";
}
for($i=7;$i>=0;$i--) { // C for unsigned char, * for repeating to the end of the input data
$cur_counter[$i] = pack ('C*', $counter);
if ($debug) {
print $cur_counter[$i]."(".dechex(ord($cur_counter[$i])).")"." from $counter
";
}
$counter = $counter >> 8;
}
if ($debug) {
foreach ($cur_counter as $char) {
print ord($char) . " ";
}
print "
";
}
$binary = implode($cur_counter);
// Pad to 8 characters
str_pad($binary, 8, chr(0), STR_PAD_LEFT);
if ($debug) {
print "Prior to HMAC calculation pad with zero on the left until 8 characters.
";
print "Calculate sha1 HMAC(Hash-based Message Authentication Code https://en.wikipedia.org/wiki/HMAC).
";
print "hash_hmac ('sha1', $binary, $key)
";
}
$result = hash_hmac ('sha1', $binary, $key);
if ($debug) {
print "Result: $result
";
}
return $result;
}
private static function oath_truncate($hash, $length = 6, $debug=false) {
$result="";
// Convert to dec
if ($debug) {
print "converting hex hash into characters
";
}
$hashcharacters = str_split($hash, 2);
if ($debug) {
print_r($hashcharacters);
print "
and convert to decimals:
";
}
for ($j=0; $j";
print "offset:".$offset;
}
$result = (
(($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);
return $result;
}
}