I am trying to decrypt an AES encrypted string from Java, in C#. When I decrypt, it returns gibberish and does not match the original plain text, which was encrypted via Java code. Pls guide me on what is going wrong here.
Attached the Java code for encryption and the C# code for decryption. Pls let me know if you need more details.
I tried AesCryptoServiceProvider as well and it did not work either. You can see the code tried in the commented code in C#.
Pls note that I can make changes on my C# code only to match the Java code and can not make any edits to Java side.
Java code for Encryption:
/** encrypt cipher */
private static final Cipher ENCRYPT_CIPHER = generateCipher(Cipher.ENCRYPT_MODE);
private static String ENCRYPT_KEY = "key";
/**
* @param val
* @return encrypted value
* @throws Exception
*/
public String encrypt(final String val) throws Exception {
return new String(Base64.encodeBase64(ENCRYPT_CIPHER.doFinal(val.getBytes()), true)).toString();
}
/**
* @param encrypt
* @return cipher
*/
protected static Cipher generateCipher(final int encrypt) {
try {
final Cipher cipher = Cipher.getInstance("AES");
cipher.init(encrypt, SecretKeyFactory.getInstance("AES").generateSecret(new IBMAESKeySpec(Base64.decodeBase64(ENCRYPT_KEY.getBytes()))));
return cipher;
} catch (final Exception e) {
return null;
}
}
C# code for decryption:
private static String ENCRYPT_KEY = "key";
public String decodeString (String encodedStr)
{
/*using (var aesCryptoProvider = new AesCryptoServiceProvider())
{
aesCryptoProvider.BlockSize = 128;
aesCryptoProvider.KeySize = 256;
aesCryptoProvider.Key = Convert.FromBase64String(ENCRYPT_KEY.ToString());
aesCryptoProvider.Padding = PaddingMode.Zeros;
aesCryptoProvider.Mode = CipherMode.ECB;
using (var decryptor = aesCryptoProvider.CreateDecryptor())
using (var memoryStream = new MemoryStream(Convert.FromBase64String(encodedStr)))
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
using (var streamReader = new StreamReader(cryptoStream, Encoding.UTF8))
{
decodedStr = streamReader.ReadToEnd();
}
}
*/
using (AesManaged aesAlg = new AesManaged())
{
aesAlg.Key = Convert.FromBase64String(ENCRYPT_KEY.ToString()); ;
aesAlg.BlockSize = 128;
aesAlg.KeySize = 256;
aesAlg.Mode = CipherMode.ECB;
aesAlg.Padding = PaddingMode.Zeros;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor();
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(Convert.FromBase64String(encodedStr)))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
decodedStr = srDecrypt.ReadToEnd();
}
}
}
}
}
