ParagonIE_Sodium_Core_AEGIS128L

10class ParagonIE_Sodium_Core_AEGIS128L extends ParagonIE_Sodium_Core_AES11{12    /**13     * @param string $ct14     * @param string $tag15     * @param string $ad16     * @param string $key17     * @param string $nonce18     * @return string19     * @throws SodiumException20     */21    public static function decrypt($ct, $tag, $ad, $key, $nonce)22    {23        $state = self::init($key, $nonce);24        $ad_blocks = (self::strlen($ad) + 31) >> 5;25        for ($i = 0; $i < $ad_blocks; ++$i) {26            $ai = self::substr($ad, $i << 5, 32);27            if (self::strlen($ai) < 32) {28                $ai = str_pad($ai, 32, "\0", STR_PAD_RIGHT);29            }30            $state->absorb($ai);31        }32 33        $msg = '';34        $cn = self::strlen($ct) & 31;35        $ct_blocks = self::strlen($ct) >> 5;36        for ($i = 0; $i < $ct_blocks; ++$i) {37            $msg .= $state->dec(self::substr($ct, $i << 5, 32));38        }39        if ($cn) {40            $start = $ct_blocks << 5;41            $msg .= $state->decPartial(self::substr($ct, $start, $cn));42        }43        $expected_tag = $state->finalize(44            self::strlen($ad) << 3,45            self::strlen($msg) << 346        );47        if (!self::hashEquals($expected_tag, $tag)) {48            try {49                // The RFC says to erase msg, so we shall try:50                ParagonIE_Sodium_Compat::memzero($msg);51            } catch (SodiumException $ex) {52                // Do nothing if we cannot memzero53            }54            throw new SodiumException('verification failed');55        }56        return $msg;57    }58 59    /**60     * @param string $msg61     * @param string $ad62     * @param string $key63     * @param string $nonce64     * @return array65     *66     * @throws SodiumException67     */68    public static function encrypt($msg, $ad, $key, $nonce)69    {70        $state = self::init($key, $nonce);71        // ad_blocks = Split(ZeroPad(ad, 256), 256)72        // for ai in ad_blocks:73        //     Absorb(ai)74        $ad_len = self::strlen($ad);75        $msg_len = self::strlen($msg);76        $ad_blocks = ($ad_len + 31) >> 5;77        for ($i = 0; $i < $ad_blocks; ++$i) {78            $ai = self::substr($ad, $i << 5, 32);79            if (self::strlen($ai) < 32) {80                $ai = str_pad($ai, 32, "\0", STR_PAD_RIGHT);81            }82            $state->absorb($ai);83        }84 85        // msg_blocks = Split(ZeroPad(msg, 256), 256)86        // for xi in msg_blocks:87        //     ct = ct || Enc(xi)88        $ct = '';89        $msg_blocks = ($msg_len + 31) >> 5;