ParagonIE_Sodium_Core_AEGIS256::encrypt( string $msg, string $ad, string $key, string $nonce ): array

75    public static function encrypt($msg, $ad, $key, $nonce)76    {77        $state = self::init($key, $nonce);78        $ad_len = self::strlen($ad);79        $msg_len = self::strlen($msg);80        $ad_blocks = ($ad_len + 15) >> 4;81        for ($i = 0; $i < $ad_blocks; ++$i) {82            $ai = self::substr($ad, $i << 4, 16);83            if (self::strlen($ai) < 16) {84                $ai = str_pad($ai, 16, "\0", STR_PAD_RIGHT);85            }86            $state->absorb($ai);87        }88 89        $ct = '';90        $msg_blocks = ($msg_len + 15) >> 4;91        for ($i = 0; $i < $msg_blocks; ++$i) {92            $xi = self::substr($msg, $i << 4, 16);93            if (self::strlen($xi) < 16) {94                $xi = str_pad($xi, 16, "\0", STR_PAD_RIGHT);95            }96            $ct .= $state->enc($xi);97        }98        $tag = $state->finalize(99            $ad_len << 3,100            $msg_len << 3101        );102        return array(103            self::substr($ct, 0, $msg_len),104            $tag105        );106 107    }