function GPG_Public_Key($asc)
{
$found = 0;
$i = strpos($asc, "-----BEGIN PGP PUBLIC KEY BLOCK-----");
if ($i === false) {
throw new Exception("Missing block header in Public Key");
}
// normalize line breaks
$asc = str_replace("\r\n", "\n", $asc);
// remove all "comment" lines which we should ignore
$lines = explode("\n", $asc);
for ($ln = 0; $ln < count($lines); $ln++) {
$line = $lines[$ln];
if (GPG_Utility::starts_with(strtolower(trim($line)), "comment:")) {
echo "REMOVING LINE\n";
unset($lines[$ln]);
}
}
$asc = implode("\n", $lines);
$a = strpos($asc, "\n", $i);
if ($a > 0) {
$a = strpos($asc, "\n", $a + 1);
}
$e = strpos($asc, "\n=", $i);
if ($a > 0 && $e > 0) {
$asc = substr($asc, $a + 2, $e - $a - 2);
} else {
throw new Exception("Unsupported Public Key format");
}
$len = 0;
$s = base64_decode($asc);
$sa = str_split($s);
for ($i = 0; $i < strlen($s);) {
$tag = ord($sa[$i++]);
if (($tag & 128) == 0) {
break;
}
if ($tag & 64) {
$tag &= 63;
$len = ord($sa[$i++]);
if ($len > 191 && $len < 224) {
$len = ($len - 192 << 8) + ord($sa[$i++]);
} else {
if ($len == 255) {
$len = (ord($sa[$i++]) << 24) + (ord($sa[$i++]) << 16) + (ord($sa[$i++]) << 8) + ord($sa[$i++]);
} else {
if ($len > 223 && len < 255) {
$len = 1 << ($len & 0x1f);
}
}
}
} else {
$len = $tag & 3;
$tag = $tag >> 2 & 15;
if ($len == 0) {
$len = ord($sa[$i++]);
} else {
if ($len == 1) {
$len = (ord($sa[$i++]) << 8) + ord($sa[$i++]);
} else {
if ($len == 2) {
$len = (ord($sa[$i++]) << 24) + (ord($sa[$i++]) << 16) + (ord($sa[$i++]) << 8) + ord($sa[$i++]);
} else {
$len = strlen($s) - 1;
}
}
}
}
if ($tag == 6 || $tag == 14) {
$k = $i;
$version = ord($sa[$i++]);
$found = 1;
$this->version = $version;
$time = (ord($sa[$i++]) << 24) + (ord($sa[$i++]) << 16) + (ord($sa[$i++]) << 8) + ord($sa[$i++]);
if ($version == 2 || $version == 3) {
$valid = ord($sa[$i++]) << 8 + ord($sa[$i++]);
}
$algo = ord($sa[$i++]);
if ($algo == 1 || $algo == 2) {
$m = $i;
$lm = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);
$i += $lm + 2;
$mod = substr($s, $m, $lm + 2);
$le = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);
$i += $le + 2;
$this->public_key = base64_encode(substr($s, $m, $lm + $le + 4));
$this->type = "RSA";
if ($version == 3) {
$this->fp = '';
$this->key_id = bin2hex(substr($mod, strlen($mod) - 8, 8));
} else {
if ($version == 4) {
$pkt = chr(0x99) . chr($len >> 8) . chr($len & 255) . substr($s, $k, $len);
$fp = sha1($pkt);
$this->fp = $fp;
$this->key_id = substr($fp, strlen($fp) - 16, 16);
} else {
$this->fp = "";
$this->key_id = "";
}
}
$found = 2;
} else {
if (($algo == 16 || $algo == 20) && $version == 4) {
$m = $i;
$lp = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);
$i += $lp + 2;
$lg = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);
$i += $lg + 2;
$ly = floor((ord($sa[$i]) * 256 + ord($sa[$i + 1]) + 7) / 8);
$i += $ly + 2;
$this->public_key = base64_encode(substr($s, $m, $lp + $lg + $ly + 6));
$pkt = chr(0x99) . chr($len >> 8) . chr($len & 255) . substr($s, $k, $len);
$fp = sha1($pkt);
$this->fp = $fp;
$this->key_id = substr($fp, strlen($fp) - 16, 16);
$this->type = "ELGAMAL";
$found = 3;
} else {
$i = $k + $len;
}
}
} else {
if ($tag == 13) {
$this->user = substr($s, $i, $len);
$i += $len;
} else {
$i += $len;
}
}
}
if ($found < 2) {
throw new Exception("Unable to parse Public Key");
// $this->version = "";
// $this->fp = "";
// $this->key_id = "";
// $this->user = "";
// $this->public_key = "";
}
}
