쿠키에 데이터를 저장하기위한 AES 암호화

Question

AES로 암호화하여 저장하기 위해 char 문자열을 가진 쿠키에 가능한 한 최대 문자를 저장해야합니다.

쿠키에는 약 4kb의 메모리가 있습니다.

그래서 나는이 문자들을 AES로 암호화 한 쿠키에 얼마나 많은 문자를 저장할 수 있는지 계산할 필요가 있습니다.

저장할 문자는 영숫자 문자열입니다.

EDIT :이 CODE

<?php 


$Pass = "132ksjcngpt04938idjsk39urtokg"; 
$Clear = "123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123456789o"; 


$crypted = fnEncrypt($Clear, $Pass); 
echo "Encrypred: ".$crypted."<br></br>"; 

$newClear = fnDecrypt($crypted, $Pass); 
echo "Decrypred: ".$newClear."<br></br>"; 



function fnEncrypt($sValue, $sSecretKey) 
{ 
    return trim(
     base64_encode(
      mcrypt_encrypt(
       MCRYPT_RIJNDAEL_128, 
       $sSecretKey, $sValue, 
       MCRYPT_MODE_ECB, 
       mcrypt_create_iv(
        mcrypt_get_iv_size(
         MCRYPT_RIJNDAEL_128, 
         MCRYPT_MODE_ECB 
        ), 
        MCRYPT_RAND) 
       ) 
      ) 
     ); 
} 

function fnDecrypt($sValue, $sSecretKey) 
{ 
    return trim(
     mcrypt_decrypt(
      MCRYPT_RIJNDAEL_128, 
      $sSecretKey, 
      base64_decode($sValue), 
      MCRYPT_MODE_ECB, 
      mcrypt_create_iv(
       mcrypt_get_iv_size(
        MCRYPT_RIJNDAEL_128, 
        MCRYPT_MODE_ECB 
       ), 
       MCRYPT_RAND 
      ) 
     ) 
    ); 
} 
?> 

I 테스트 OF MY 조각 평문과 chipertext

양쪽 모두 UTF-8 영숫자 문자를 허용 할 수 있으며 이는 결과 :

Encrypred: 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 

Decrypred: 123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123hryd{}ls.-''ksllasllallallallallal:{}::{}jdhhfn123456789o 

chiperText는 3040이다 암호화 UTF-8 문자

의 compoused되고 최대 4056 utf-8 문자

Answer 1

는 바이트에서 원시 암호문의 크기는 일반 텍스트 크기보다 32 바이트 커집니다. 16 개는 무작위 IV 용이고 MAC 용 16 개입니다.

이제 임의 바이트가 유효한 UTF-8이 아니므로 문제를 해결할 수 있도록 인코딩이 필요합니다. Base64는 많이 사용되는 변형이지만 크기를 원래 크기의 4/3로 늘립니다.
크기 제한이 4KB 일 경우 최대 3040 바이트의 일반 텍스트를 지원할 수 있습니다.

다른보다 효율적인 인코딩이 있지만 더 복잡해지고 어떤 문자가 유효한지 알아야합니다 (예 : \0). 절대적으로 필요한 경우를 제외하고는 권장하지 않습니다. 거의 모든 모드의 최악의

당신은 암호화 및 암호 해독에 동일한 IV 필요

1. 당신은 ECB를 사용 :

   ---

   코드는 실수도 많이 있습니다. 암호문 옆에 저장하십시오. 당신은 ECB가 IV를 사용하지 않기 때문에 그것을 알아 채지 못합니다.

2. 인증이 없습니다.
3. IV 세대가 좋지 않습니다. MCRYPT_RAND 대신 MCRYPT_DEV_URANDOM을 사용하십시오.

Answer 2

AES가 16 바이트 길이의 블록 (16 문자의 영숫자 문자로 볼 수 있음)을 사용하므로 잘못 입력했지만 일반 문자로 영숫자 문자로 UTF-8을 사용한다고 가정 해 보겠습니다. 이 컨텍스트에서) 일반 텍스트는 최소한 15 바이트로 패딩됩니다 (최악의 시나리오).

(n + 16) - (n % 16) 

그냥 내 2 센트 : 당신의 일반 텍스트의 길이 n을 부여 그래서

는, 결과 암호문 길이로 유추 할 수있다. 다리오. 당신은 AES-GCM으로 인증 된 스트리밍 모드를 사용하는 경우