【发布时间】：2018-11-11 22:18:00
【问题描述】：
我必须在 C++ 库和 php 之间进行统一的数据加密。这真的是我对 AES 的第一次冒险。我一直在阅读我能阅读的内容，并试图弄清楚。我想出了下面的代码。我似乎无法获得匹配的输出。几天来，我一直试图弄清楚这一点。
我注意到 php 和 CPP 版本的输出非常接近。
从 CPP 函数我们得到ta4SK7e1ziUMnBchxqol/TT82wNS8TmJQ/kFls+I04HuK4nP7kDT4J2zYJDB6WIx，从 php 我们得到ta4SK7e1ziUMnBchxqol/TT82wNS8TmJQ/kFls+I04H6XsCH1kfyiS/gu2oi57yY。如果你看，他们真的很近。只有最后几个字节不同。
所以我知道我很接近了，但我真的看不出我做错了什么。
这里是 C++ 代码：
QByteArray encryptAES(QByteArray passphrase, QByteArray plainText, QByteArray myiv)
{
unsigned char* Key = (unsigned char*) passphrase.data();
unsigned char* IV = (unsigned char*) myiv.data();
/** Setup the AES Key structure required for use in the OpenSSL APIs **/
AES_KEY* AesKey = new AES_KEY();
AES_set_encrypt_key(Key, 256, AesKey);
/** take an input string and pad it so it fits into 16 bytes (AES Block Size) **/
const int UserDataSize = (const int)plainText.size(); // Get the length pre-padding
int RequiredPadding = (AES_BLOCK_SIZE - (UserDataSize % AES_BLOCK_SIZE)); // Calculate required padding
for(int i=0; i < RequiredPadding; i++) {
plainText.push_back('\0');
}
unsigned char * UserData = (unsigned char*) plainText.data(); // Get the padded text as an unsigned char array
const int UserDataSizePadded = (const int)plainText.size();// and the length (OpenSSl is a C-API)
/** Peform the encryption **/
unsigned char EncryptedData[UserDataSizePadded] = {0}; // Hard-coded Array for OpenSSL (C++ can't dynamic arrays)
AES_cbc_encrypt(UserData, EncryptedData, UserDataSizePadded, (const AES_KEY*)AesKey, IV, AES_ENCRYPT);
QByteArray encrypted = QByteArray(reinterpret_cast<char*>(EncryptedData), UserDataSizePadded);
return encrypted;
}
QByteArray decryptAES(QByteArray passphrase, QByteArray encryptedText, QByteArray myiv)
{
unsigned char* Key = (unsigned char*) passphrase.data();
unsigned char* IV = (unsigned char*) myiv.data();
\
/** Setup an AES Key structure for the decrypt operation **/
AES_KEY* AesDecryptKey = new AES_KEY(); // AES Key to be used for Decryption
AES_set_decrypt_key(Key, 256, AesDecryptKey); // We Initialize this so we can use the OpenSSL Encryption API
/** Decrypt the data. Note that we use the same function call. Only change is the last parameter **/
unsigned char DecryptedData[encryptedText.size()] = {0}; // Hard-coded as C++ doesn't allow for dynamic arrays and OpenSSL requires an array
AES_cbc_encrypt((unsigned char*) encryptedText.data(), DecryptedData, encryptedText.size(), (const AES_KEY*)AesDecryptKey, IV, AES_DECRYPT);
QByteArray decrypted = QByteArray(reinterpret_cast<char*>(DecryptedData), encryptedText.size());
return decrypted;
}
int main(int argc, char *argv[])
{
QByteArray plainText("This string was AES-256-CBC encrypted.");
QByteArray phpEnc = QByteArray("ta4SK7e1ziUMnBchxqol/TT82wNS8TmJQ/kFls+I04H6XsCH1kfyiS/gu2oi57yY");
QByteArray key = QByteArray::fromBase64("pE4B5J5u18U55BTJho//Fioy2bEURa5W/o7HrO1O7/s=");
QByteArray iv = QByteArray::fromBase64("Gi9kSb/a5f0h7Mb+sRWQdQ==");
qDebug() << "AES Test KEY: " << key.toBase64();
qDebug() << "AES Test IV: " << iv.toBase64();
QByteArray enc = encryptAES(key,plainText, iv);
qDebug() << "AES Test Encrypt: " << enc.toBase64();
qDebug() << "AES Test Decrypt: " << decryptAES(key, enc, iv);
qDebug() << "AES Test Decrypt PHP: " << decryptAES(key, phpEnc, iv);
}
现在是php代码：
<?php
$method = 'AES-256-CBC';
$txt = "This string was AES-256-CBC encrypted.";
$iv = base64_decode("Gi9kSb/a5f0h7Mb+sRWQdQ==");
$key = base64_decode("pE4B5J5u18U55BTJho//Fioy2bEURa5W/o7HrO1O7/s=");
echo "AES Test KEY: ". base64_encode($iv)."\n\n<br>";
echo "AES Test IV: ". base64_encode($key)."\n\n<br>"."\n\n<br>";
$fromCPP = "ta4SK7e1ziUMnBchxqol/TT82wNS8TmJQ/kFls+I04HuK4nP7kDT4J2zYJDB6WIx";
$enc = openssl_encrypt($txt, $method, $key, OPENSSL_RAW_DATA, $iv);
$dec = openssl_decrypt($enc, $method, $key, OPENSSL_RAW_DATA, $iv);
//Test if php isn't padding
$UserDataSize = strlen($txt);
$RequiredPadding == (16 - ($UserDataSize % 16));
$paddedText = $txt;
for($i=0; $i < $RequiredPadding; $i++)
$paddedText .= "\0";
$enc2 = openssl_encrypt($paddedText, $method, $key, OPENSSL_RAW_DATA, $iv);
$dec2 = openssl_decrypt($enc2, $method, $key, OPENSSL_RAW_DATA, $iv);
//Try to decrypt CPP
$dec3 = openssl_decrypt(base64_decode($fromCPP), $method, $key, OPENSSL_RAW_DATA, $iv);
echo "AES Test Encrypt: ". base64_encode($enc)."\n\n<br>";
echo "AES Test Decrypt: ". $dec."\n\n<br>";
echo "AES Test Encrypt Padded: ". base64_encode($enc2)."\n\n<br>";
echo "AES Test Decrypt Padded: ". $dec2."\n\n<br>";
echo "AES Test Decrypt CPP: ". $dec3."\n\n<br>";
?>
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