[英]Error while decrypting file in java which is encrypted in.Net using Rijndael
我得到了Rijndael .Net加密文件和.Net RSA XML密鑰,並要求用Java對其解密。
提供給我的密鑰是256位。
我已經解析了RSA XML文件並用Java生成了公共密鑰。 我嘗試使用生成的密鑰解密,但是我收到異常的Illegal Key Size
異常,我認為我的Java代碼做錯了什么。
任何人都可以幫助檢查我的代碼是否有問題嗎?
.Net加密代碼:
public static void EncryptFile(string fileIn, string fileOut,
string publicKeyName, string publicKeyFile)
{
try
{
// Read the public key from key file
StreamReader sr = new StreamReader(publicKeyFile);
string strKeyText = sr.ReadToEnd();
sr.Close();
//Initialize Key container and Crypto service provider
RSACryptoServiceProvider rsa;
CspParameters cspp = new CspParameters();
cspp.KeyContainerName = publicKeyName;
rsa = new RSACryptoServiceProvider(cspp);
rsa.FromXmlString(strKeyText);
rsa.PersistKeyInCsp = true;
// Create instance of Rijndael for
// symetric encryption of the data.
RijndaelManaged alg = new RijndaelManaged();
// Key size is set to 256 for strong encryption
alg.KeySize = 256;
alg.BlockSize = 256;
// Cipher Mode is set to CBC to process the file in chunks
alg.Mode = CipherMode.CBC;
// Set padding mode to process the last block of the file
alg.Padding = PaddingMode.ISO10126;
ICryptoTransform transform = alg.CreateEncryptor();
// Use RSACryptoServiceProvider to
// enrypt the Rijndael key.
byte[] KeyEncrypted = rsa.Encrypt(alg.Key, false);
// Create byte arrays to contain
// the length values of the key and IV.
int intKeyLength = KeyEncrypted.Length;
byte[] LenK = BitConverter.GetBytes(intKeyLength);
int intIVLength = alg.IV.Length;
byte[] LenIV = BitConverter.GetBytes(intIVLength);
using (FileStream fsOut = new FileStream(fileOut, FileMode.Create))
{
// Write the following to the FileStream
// for the encrypted file (fsOut):
// - length of the key
// - length of the IV
// - ecrypted key
// - the IV
// - the encrypted cipher content
fsOut.Write(LenK, 0, 4);
fsOut.Write(LenIV, 0, 4);
fsOut.Write(KeyEncrypted, 0, intKeyLength);
fsOut.Write(alg.IV, 0, intIVLength);
// Now write the cipher text using
// a CryptoStream for encrypting.
using (CryptoStream cs = new CryptoStream(fsOut, transform, CryptoStreamMode.Write))
{
// intBlockSizeBytes can be any arbitrary size.
int intBlockSizeBytes = alg.BlockSize / 8;
byte[] DataBytes = new byte[intBlockSizeBytes];
int intBytesRead = 0;
using (FileStream fsIn = new FileStream(fileIn, FileMode.Open))
{
// By encrypting a chunk at
// a time, you can save memory
// and accommodate large files.
int intCount;
int intOffset = 0;
do
{
// if last block size is less than encryption chunk size
// use the last block size and padding character is used
// for remaining bytes
if (intBlockSizeBytes > (fsIn.Length - fsIn.Position))
{
intBlockSizeBytes = ((int)(fsIn.Length - fsIn.Position));
DataBytes = new byte[intBlockSizeBytes];
}
// read data bytes
intCount = fsIn.Read(DataBytes, 0, intBlockSizeBytes);
intOffset += intCount;
// write it into crypto stream
cs.Write(DataBytes, 0, intCount);
intBytesRead += intBlockSizeBytes;
} while (intCount > 0);
// close input file
fsIn.Close();
}
// close crypto stream
cs.FlushFinalBlock();
cs.Close();
}
// close output file
fsOut.Close();
}
}
catch
{
throw;
}
}
我寫來解密的Java代碼:
byte[] expBytes = Base64.decodeBase64(pkey.getExponentEle().trim());
byte[] modBytes = Base64.decodeBase64(pkey.getModulusEle().trim());
byte[] dBytes = Base64.decodeBase64(pkey.getdEle().trim());
BigInteger modules = new BigInteger(1, modBytes);
BigInteger exponent = new BigInteger(1, expBytes);
BigInteger d = new BigInteger(1, dBytes);
KeyFactory factory = KeyFactory.getInstance("RSA");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
RSAPublicKeySpec pubSpec = new RSAPublicKeySpec(modules, exponent);
PublicKey pubKey = factory.generatePublic(pubSpec);
final byte[] keyData = Arrays.copyOf(pubKey.getEncoded(), 256
/ Byte.SIZE);
final byte[] ivBytes = Arrays.copyOf(keyData, cipher.getBlockSize());
AlgorithmParameterSpec paramSpec = new IvParameterSpec(ivBytes);
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(keyData, "AES"), paramSpec);
byte[] decrypted = cipher.doFinal(encrypted);
System.out.println("decrypted: " + new String(decrypted));
如果我將密碼初始化更改為cipher.init(Cipher.DECRYPT_MODE, pubKey);
,然后出現錯誤Invalid AES key length: 162 bytes
您使用公鑰的方式錯誤。 您真的了解C#程序的工作原理嗎? 它使用什么參數?
您只是將公共密鑰位用作AES密鑰(即使我不太了解如何從中獲取162個字節)。
這是“混合加密”的示例-數據本身通過隨機AES密鑰(在此您聲明為256位)加密,而AES密鑰(在本例中為IV)也由RSA公鑰加密。 在Java中,有很多示例如何做到這一點 。
即使解密AES密鑰,您也應該知道用於加密它的參數(RSA / ECB / PKCS5Padding,RSA-AOEP等),盡管它應該位於XML內。
輸入參數-您正在使用PKCS5Padding
,但是檢查.NET代碼,則有所不同
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.