function verifySigature($message, $sign, $exponent, $modulus)
{
$intSign = bin2int(hex2bin($sign));
$intExponent = bin2int(hex2bin($exponent));
$intModulus = bin2int(hex2bin($modulus));
$intResult = powmod($intSign, $intExponent, $intModulus);
$hexResult = bin2hex(int2bin($intResult));
$md5Message = md5($message);
if ($md5Message == substr($hexResult, -32)) {
return "1";
} else {
return "0";
}
}
function rsa_decrypt($input)
{
global $private_key;
$check = bchexdec($input);
$modulus = bin2int($private_key["modulus"]);
$exponent = bchexdec("010001");
$result = bcpowmod($check, $exponent, $modulus);
$rb = bcdechex($result);
return strtoupper(padstr($rb));
}
/**
* バイナリデータからGIF画像の情報を取得して返す
*
* @param string &$data 画像のバイナリデータ
* @param array &$image_info 取得した画像情報を格納する配列
*
* @return boolean true => 情報の取得に成功
* false => エラー発生
*/
function getInfo(&$data, &$image_info)
{
//画像タイプにJPEGを設定。
$image_info['type'] = IMAGETYPE_GIF;
$image_info['extension'] = 'gif';
$bin_w = substr($data, 6, 2);
$bin_h = substr($data, 8, 2);
$image_info['w'] = bin2int($bin_w, 'v');
$image_info['h'] = bin2int($bin_h, 'v');
return true;
}
function bitOr($num1, $num2, $start_pos)
{
$start_byte = intval($start_pos / 8);
$start_bit = $start_pos % 8;
$tmp1 = int2bin($num1);
$num2 = bcmul($num2, 1 << $start_bit);
$tmp2 = int2bin($num2);
if ($start_byte < strlen($tmp1)) {
$tmp2 |= substr($tmp1, $start_byte);
$tmp1 = substr($tmp1, 0, $start_byte) . $tmp2;
} else {
$tmp1 = str_pad($tmp1, $start_byte, "") . $tmp2;
}
return bin2int($tmp1);
}
function rsa_decrypt($enc_data, $p, $q, $d)
{
$enc_data = int2bin($enc_data);
$exp = $d;
$modulus = bcmul($p, $q);
$data_len = strlen($enc_data);
$chunk_len = bitLen($modulus) - 1;
$block_len = (int) ceil($chunk_len / 8);
$curr_pos = 0;
$bit_pos = 0;
$plain_data = 0;
while ($curr_pos < $data_len) {
$tmp = bin2int(substr($enc_data, $curr_pos, $block_len));
$tmp = bcpowmod($tmp, $exp, $modulus);
$plain_data = bitOr($plain_data, $tmp, $bit_pos);
$bit_pos += $chunk_len;
$curr_pos += $block_len;
}
return int2bin($plain_data);
}
