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Crypto++ を使用して暗号化されたデータを PHP サイトに送信する C++ アプリケーションがあります。ただし、データが PHP 側に到達すると、データが適切に復号化されません。

C++ / Crypto++ コード:

char stupidKey[AES::MAX_KEYLENGTH] = "thisisastupidkeythisisastupidke";

ECB_Mode<AES>::Encryption aes((byte *)stupidKey, AES::MAX_KEYLENGTH);

std::string cypher;
StringSource(aData, true, new StreamTransformationFilter(aes, new StringSink( cypher ))); 
StringSource(cypher, true, new Base64Encoder( new StringSink(aOutput) ));

PHP コード:

define('CRYPT_SECRET', 'thisisastupidkeythisisastupidke');

$postData = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, 
                CRYPT_SECRET, base64_decode($_POST['request']), 
                MCRYPT_MODE_ECB);

注: ECB が暗号化モードとして不適切な選択であることは承知していますが、最初に IV の奇妙な点を追加せずにこれを機能させ、次に問題を複雑にしたいと考えています。

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3 に答える 3

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PHP のマニュアル (http://php.net/manual/en/function.mcrypt-decrypt.php) を見ると、MCRYPT_RIJNDAEL_256 は AES_256 とは異なります。最初のコメントはいくつかの助けを提供します: http://www.php.net/manual/en/function.mcrypt-decrypt.php#105985

注意、MCRYPT_RIJNDAEL_256 は AES_256 と同等ではありません。

openssl を使用して RIJNDAEL を AES から復号化する方法は、MCRYPT_RIJNDAEL_128 を使用し、次の関数で暗号化する前に文字列をパディングして暗号化することです。

<?php 
function pkcs5_pad ($text, $blocksize) { 
    $pad = $blocksize - (strlen($text) % $blocksize); 
    return $text . str_repeat(chr($pad), $pad); 
} 
?>

復号化では、AES_256 または AES_128 などの選択は、暗号化で使用されるキーサイズに基づいています。私の場合は 128 ビット キーだったので、AES_128 を使用しました。

于 2012-08-29T23:12:13.377 に答える
0 
Client Side using ECB - DES_EDE3
==================================

#include "cryptlib.h"
#include "modes.h"
#include "des.h"
#include "base64.h" <-- any base64 encoder/decoder i found the usage of crypto++ base64 class a bit hard to use since you have to know how many byte are taken to encode a byte in base 64...
#include "hex.h"

// Encode the data using the handy Crypto++ base64 encoder. Base64 uses
// 3 characters to store 2 characters.
const int BUFFER_LENGTH = 255;
byte plaintext[BUFFER_LENGTH];
byte ciphertext[BUFFER_LENGTH];
byte newciphertext[BUFFER_LENGTH];
byte decrypted[BUFFER_LENGTH];

CryptoPP::Base64Encoder base64Encoder;
CBase64Coding base64Coder;
CString MySensitiveDataUncrypted;
CString MySensitiveData;

// Set up the same key and IV
const int KEY_LENGTH = 24;
const int BLOCK_SIZE = CryptoPP::DES::BLOCKSIZE;
byte key[KEY_LENGTH], iv[CryptoPP::DES::BLOCKSIZE];
memset( key, 0, KEY_LENGTH);
memcpy( key, "012345678901234567890123", KEY_LENGTH );
memset( iv, 0, CryptoPP::DES::BLOCKSIZE);
memcpy( iv, "01234567", CryptoPP::DES::BLOCKSIZE );
memset( plaintext, 0, BUFFER_LENGTH);
memset( ciphertext, 0, BUFFER_LENGTH);
memset( newciphertext, 0, BUFFER_LENGTH);
strcpy((char*)plaintext,MySensitiveDataUncrypted.GetBuffer(0));
// now encrypt
CryptoPP::ECB_Mode::Encryption ecbEncryption(key, sizeof(key));
ecbEncryption.ProcessString(newciphertext, plaintext, BUFFER_LENGTH);
// your own base64 encoder/decoder
base64Coder.Encode((char *)newciphertext,BUFFER_LENGTH,(char *)ciphertext);
MySensitiveData.Format(_T("%s"),ciphertext);

// MySensitiveData can now be send over http


Server Side in PHP using ECB - DES_EDE3
=========================================

// $MyBase64EncodedSecretString will receive/store the encrypted string which will also be base64Encoded for HTTP protocol convenience

$key = "012345678901234567890123";
$iv = "01234567";

// Set up an "encryption" descriptor. This is basically just an object that
// encapsulates the encryption algorithm. 'tripledes' is the name of the
// algorithm, which is simply the DES algorithm done three times back to
// back. 'ecb' describes how to encrypt different blocks. See, DES
// actually only encrypts 8-byte blocks at a time. To encrypt more than 8
// bytes of data, you break the data up into 8-byte chunks (padding the
// last chunk with NULL, if need be), and then encrypt each block
// individually. Now, ECB (which stands for "Electronic Code Book", for
// whatever that's worth) means that each 8-byte block is encrypted
// independently. This has pros and cons that I don't care to discuss.
// The other option is CBC ("Cipher Block Chaining") which links the blocks,
// such as by XORing each block with the encrypted result of the previous
// block. Security geeks probably really get excited about this, but for my
// needs, I don't really care.
$td = mcrypt_module_open( 'tripledes', '', 'ecb', '' );
mcrypt_generic_init( $td, $key, $iv );

// Grab some interesting data from the descriptor.
// $maxKeySize = 24, meaning 24 bytes
// $maxIVSize = 8, meaning 8 bytes
$maxKeySize = mcrypt_enc_get_key_size( $td );
$maxIVSize = mcrypt_enc_get_iv_size( $td );
//echo "maxKeySize=$maxKeySize, maxIVSize=$maxIVSize\n";

// let's decrypt it and verify the result. Because DES pads
// the end of the original block with NULL bytes, let's trim those off to
// create the final result.
$MyEncodedSecretString = base64_decode( $MyBase64EncodedSecretString );
$MyDecodedString = rtrim( mdecrypt_generic( $td, $MyEncodedSecretString ), "\0" );

// And finally, clean up the encryption object
mcrypt_generic_deinit($td);
mcrypt_module_close($td);


Client Side Stronger Encryption using RSA
=========================================

First you will need to generate a public/private key pair using crypto++ keygen console application then your client code should be something like

// Client Side Using RSA
#include "cryptlib.h"
#include "rsa.h"
#include "hex.h"
#include "randpool.h"
#include "filesource.h"

CString MyNotverySecretStringInMemory;
CString MySensitiveData;
char pubFilename[128];
char seed[1024], message[1024];

// MAX = 19999991
strcpy(seed,"12345");

CString tmpPath;
TCHAR appPath[MAX_PATH];
::GetModuleFileName(NULL,appPath,MAX_PATH);

tmpPath = appPath;
tmpPath = tmpPath.Left(tmpPath.ReverseFind('\\')+1);
tmpPath += "public.key"; // 1024 key length for higher security.

strcpy(pubFilename,tmpPath.GetBuffer(0));
strcpy(message,MyNotverySecretStringInMemory.GetBuffer(0));
CryptoPP::FileSource pubFile(pubFilename, true, new CryptoPP::HexDecoder);
CryptoPP::RSAES_OAEP_SHA_Encryptor pub(pubFile);
CryptoPP::RandomPool randPool;
randPool.IncorporateEntropy((byte *)seed, strlen(seed));
std::string result;
CryptoPP::StringSource(message, true, new CryptoPP::PK_EncryptorFilter(randPool, pub, new CryptoPP::HexEncoder(new CryptoPP::StringSink(result))));
MySensitiveData.Format(_T("%s"),result.c_str());
于 2013-01-25T04:48:40.107 に答える