审查视图

simplewind/vendor/overtrue/wechat/src/Encryption/Encryptor.php 7.2 KB
1  
潘浩文 authored
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306
<?php

/*
 * This file is part of the overtrue/wechat.
 *
 * (c) overtrue <i@overtrue.me>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

/**
 * Encryptor.php.
 *
 * @author    overtrue <i@overtrue.me>
 * @copyright 2015 overtrue <i@overtrue.me>
 *
 * @see      https://github.com/overtrue
 * @see      http://overtrue.me
 */

namespace EasyWeChat\Encryption;

use EasyWeChat\Core\Exceptions\InvalidConfigException;
use EasyWeChat\Support\XML;
use Exception as BaseException;

/**
 * Class Encryptor.
 */
class Encryptor
{
    /**
     * App id.
     *
     * @var string
     */
    protected $appId;

    /**
     * App token.
     *
     * @var string
     */
    protected $token;

    /**
     * AES key.
     *
     * @var string
     */
    protected $AESKey;

    /**
     * Block size.
     *
     * @var int
     */
    protected $blockSize;

    /**
     * Constructor.
     *
     * @param string $appId
     * @param string $token
     * @param string $AESKey
     */
    public function __construct($appId, $token, $AESKey)
    {
        $this->appId = $appId;
        $this->token = $token;
        $this->AESKey = $AESKey;
        $this->blockSize = 32;
    }

    /**
     * Encrypt the message and return XML.
     *
     * @param string $xml
     * @param string $nonce
     * @param int    $timestamp
     *
     * @return string
     */
    public function encryptMsg($xml, $nonce = null, $timestamp = null)
    {
        $encrypt = $this->encrypt($xml, $this->appId);

        !is_null($nonce) || $nonce = substr($this->appId, 0, 10);
        !is_null($timestamp) || $timestamp = time();

        //生成安全签名
        $signature = $this->getSHA1($this->token, $timestamp, $nonce, $encrypt);

        $response = [
            'Encrypt' => $encrypt,
            'MsgSignature' => $signature,
            'TimeStamp' => $timestamp,
            'Nonce' => $nonce,
        ];

        //生成响应xml
        return XML::build($response);
    }

    /**
     * Decrypt message.
     *
     * @param string $msgSignature
     * @param string $nonce
     * @param string $timestamp
     * @param string $postXML
     *
     * @return array
     *
     * @throws EncryptionException
     */
    public function decryptMsg($msgSignature, $nonce, $timestamp, $postXML)
    {
        try {
            $array = XML::parse($postXML);
        } catch (BaseException $e) {
            throw new EncryptionException('Invalid xml.', EncryptionException::ERROR_PARSE_XML);
        }

        $encrypted = $array['Encrypt'];

        $signature = $this->getSHA1($this->token, $timestamp, $nonce, $encrypted);

        if ($signature !== $msgSignature) {
            throw new EncryptionException('Invalid Signature.', EncryptionException::ERROR_INVALID_SIGNATURE);
        }

        return XML::parse($this->decrypt($encrypted, $this->appId));
    }

    /**
     * Get SHA1.
     *
     * @return string
     *
     * @throws EncryptionException
     */
    public function getSHA1()
    {
        try {
            $array = func_get_args();
            sort($array, SORT_STRING);

            return sha1(implode($array));
        } catch (BaseException $e) {
            throw new EncryptionException($e->getMessage(), EncryptionException::ERROR_CALC_SIGNATURE);
        }
    }

    /**
     * Encode string.
     *
     * @param string $text
     *
     * @return string
     */
    public function encode($text)
    {
        $padAmount = $this->blockSize - (strlen($text) % $this->blockSize);

        $padAmount = 0 !== $padAmount ? $padAmount : $this->blockSize;

        $padChr = chr($padAmount);

        $tmp = '';

        for ($index = 0; $index < $padAmount; ++$index) {
            $tmp .= $padChr;
        }

        return $text.$tmp;
    }

    /**
     * Decode string.
     *
     * @param string $decrypted
     *
     * @return string
     */
    public function decode($decrypted)
    {
        $pad = ord(substr($decrypted, -1));

        if ($pad < 1 || $pad > $this->blockSize) {
            $pad = 0;
        }

        return substr($decrypted, 0, (strlen($decrypted) - $pad));
    }

    /**
     * Return AESKey.
     *
     * @return string
     *
     * @throws InvalidConfigException
     */
    protected function getAESKey()
    {
        if (empty($this->AESKey)) {
            throw new InvalidConfigException("Configuration mission, 'aes_key' is required.");
        }

        if (43 !== strlen($this->AESKey)) {
            throw new InvalidConfigException("The length of 'aes_key' must be 43.");
        }

        return base64_decode($this->AESKey.'=', true);
    }

    /**
     * Encrypt string.
     *
     * @param string $text
     * @param string $appId
     *
     * @return string
     *
     * @throws EncryptionException
     */
    private function encrypt($text, $appId)
    {
        try {
            $key = $this->getAESKey();
            $random = $this->getRandomStr();
            $text = $this->encode($random.pack('N', strlen($text)).$text.$appId);

            $iv = substr($key, 0, 16);

            $encrypted = openssl_encrypt($text, 'aes-256-cbc', $key, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $iv);

            return base64_encode($encrypted);
        } catch (BaseException $e) {
            throw new EncryptionException($e->getMessage(), EncryptionException::ERROR_ENCRYPT_AES);
        }
    }

    /**
     * Decrypt message.
     *
     * @param string $encrypted
     * @param string $appId
     *
     * @return string
     *
     * @throws EncryptionException
     */
    private function decrypt($encrypted, $appId)
    {
        try {
            $key = $this->getAESKey();
            $ciphertext = base64_decode($encrypted, true);
            $iv = substr($key, 0, 16);

            $decrypted = openssl_decrypt($ciphertext, 'aes-256-cbc', $key, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $iv);
        } catch (BaseException $e) {
            throw new EncryptionException($e->getMessage(), EncryptionException::ERROR_DECRYPT_AES);
        }

        try {
            $result = $this->decode($decrypted);

            if (strlen($result) < 16) {
                return '';
            }

            $content = substr($result, 16, strlen($result));
            $listLen = unpack('N', substr($content, 0, 4));
            $xmlLen = $listLen[1];
            $xml = substr($content, 4, $xmlLen);
            $fromAppId = trim(substr($content, $xmlLen + 4));
        } catch (BaseException $e) {
            throw new EncryptionException($e->getMessage(), EncryptionException::ERROR_INVALID_XML);
        }

        if ($fromAppId !== $appId) {
            throw new EncryptionException('Invalid appId.', EncryptionException::ERROR_INVALID_APPID);
        }

        $dataSet = json_decode($xml, true);
        if ($dataSet && (JSON_ERROR_NONE === json_last_error())) {
            // For mini-program JSON formats.
            // Convert to XML if the given string can be decode into a data array.
            $xml = XML::build($dataSet);
        }

        return $xml;
    }

    /**
     * Generate random string.
     *
     * @return string
     */
    private function getRandomStr()
    {
        return substr(str_shuffle('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz'), 0, 16);
    }
}