<?php
class PKCS7Encoder
{
public static $blockSize = 32;
function encode($text)
{
$amount_to_pad = PKCS7Encoder::$blockSize - (strlen($text) % PKCS7Encoder::$blockSize);
if ($amount_to_pad == 0) {
$amount_to_pad = PKCS7Encoder::$blockSize;
}
list($pad_chr, $tmp) = [chr($amount_to_pad), ''];
for ($index = 0; $index < $amount_to_pad; $index++) {
$tmp .= $pad_chr;
}
return $text . $tmp;
}
function decode($text)
{
$pad = ord(substr($text, -1));
if ($pad < 1 || $pad > PKCS7Encoder::$blockSize) {
$pad = 0;
}
return substr($text, 0, strlen($text) - $pad);
}
}
class Prpcrypt
{
public $key;
function __construct($key)
{
$this->key = base64_decode("{$key}=");
}
public function encrypt($text, $appid)
{
try {
$random = $this->getRandomStr();
$iv = substr($this->key, 0, 16);
$pkcEncoder = new PKCS7Encoder();
$text = $pkcEncoder->encode($random . pack("N", strlen($text)) . $text . $appid);
$encrypted = openssl_encrypt($text, 'AES-256-CBC', substr($this->key, 0, 32), OPENSSL_ZERO_PADDING, $iv);
return [ErrorCode::$OK, $encrypted];
} catch (Exception $e) {
return [ErrorCode::$EncryptAESError, null];
}
}
public function decrypt($encrypted)
{
try {
$iv = substr($this->key, 0, 16);
$decrypted = openssl_decrypt($encrypted, 'AES-256-CBC', substr($this->key, 0, 32), OPENSSL_ZERO_PADDING, $iv);
} catch (Exception $e) {
return [ErrorCode::$DecryptAESError, null];
}
try {
$pkcEncoder = new PKCS7Encoder();
$result = $pkcEncoder->decode($decrypted);
if (strlen($result) < 16) {
return [ErrorCode::$DecryptAESError, null];
}
$content = substr($result, 16, strlen($result));
$len_list = unpack("N", substr($content, 0, 4));
$xml_len = $len_list[1];
return [0, substr($content, 4, $xml_len), substr($content, $xml_len + 4)];
} catch (Exception $e) {
return [ErrorCode::$IllegalBuffer, null];
}
}
function getRandomStr($str = "")
{
$str_pol = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz";
$max = strlen($str_pol) - 1;
for ($i = 0; $i < 16; $i++) {
$str .= $str_pol[mt_rand(0, $max)];
}
return $str;
}
}
class ErrorCode
{
public static $OK = 0;
public static $ParseXmlError = 40002;
public static $IllegalAesKey = 40004;
public static $IllegalBuffer = 40008;
public static $EncryptAESError = 40006;
public static $DecryptAESError = 40007;
public static $EncodeBase64Error = 40009;
public static $DecodeBase64Error = 40010;
public static $GenReturnXmlError = 40011;
public static $ValidateAppidError = 40005;
public static $ComputeSignatureError = 40003;
public static $ValidateSignatureError = 40001;
public static $errCode = [
'0' => '处理成功',
'40001' => '校验签名失败',
'40002' => '解析xml失败',
'40003' => '计算签名失败',
'40004' => '不合法的AESKey',
'40005' => '校验AppID失败',
'40006' => 'AES加密失败',
'40007' => 'AES解密失败',
'40008' => '公众平台发送的xml不合法',
'40009' => 'Base64编码失败',
'40010' => 'Base64解码失败',
'40011' => '公众帐号生成回包xml失败',
];
public static function getErrText($code)
{
if (isset(self::$errCode[$code])) {
return self::$errCode[$code];
}
return false;
}
}