现在我在我的android项目中使用scotabb libs AESCryptor进行AES加密,
我真的需要字符串IV bcs我在swift(IOS)和webservice(c#)中使用AES加密/解密256和String IV的其他项目。
但是在使用空白IV的scotabb aesencriptor中。
是否可以将空白IV(字节)更改为16长度的字符串? 以及如何做到这一点?
这是我的班级
public final class AEScrypt{
private static final String TAG = "AESCrypt";
//AESCrypt-ObjC uses CBC and PKCS7Padding
private static final String AES_MODE = "AES/CBC/PKCS7Padding";
private static final String CHARSET = "UTF-8";
//AESCrypt-ObjC uses SHA-256 (and so a 256-bit key)
private static final String HASH_ALGORITHM = "SHA-256";
//AESCrypt-ObjC uses blank IV (not the best security, but the aim here is compatibility)
private static final byte[] ivBytes = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
//togglable log option (please turn off in live!)
public static boolean DEBUG_LOG_ENABLED = false;
private static SecretKeySpec generateKey(final String password) throws NoSuchAlgorithmException, UnsupportedEncodingException {
final MessageDigest digest = MessageDigest.getInstance(HASH_ALGORITHM);
byte[] bytes = password.getBytes("UTF-8");
digest.update(bytes, 0, bytes.length);
byte[] key = digest.digest();
log("SHA-256 key ", key);
SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
return secretKeySpec;
}
public static String encrypt(final String password, String message)
throws GeneralSecurityException {
try {
final SecretKeySpec key = generateKey(password);
log("message", message);
byte[] cipherText = encrypt(key, ivBytes, message.getBytes(CHARSET));
//NO_WRAP is important as was getting \n at the end
String encoded = Base64.encodeToString(cipherText, Base64.NO_WRAP);
log("Base64.NO_WRAP", encoded);
return encoded;
} catch (UnsupportedEncodingException e) {
if (DEBUG_LOG_ENABLED)
Log.e(TAG, "UnsupportedEncodingException ", e);
throw new GeneralSecurityException(e);
}
}
public static byte[] encrypt(final SecretKeySpec key, final byte[] iv, final byte[] message)
throws GeneralSecurityException {
final Cipher cipher = Cipher.getInstance(AES_MODE);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
byte[] cipherText = cipher.doFinal(message);
log("cipherText", cipherText);
return cipherText;
}
public static String decrypt(final String password, String base64EncodedCipherText)
throws GeneralSecurityException {
try {
final SecretKeySpec key = generateKey(password);
log("base64EncodedCipherText", base64EncodedCipherText);
byte[] decodedCipherText = Base64.decode(base64EncodedCipherText, Base64.NO_WRAP);
log("decodedCipherText", decodedCipherText);
byte[] decryptedBytes = decrypt(key, ivBytes, decodedCipherText);
log("decryptedBytes", decryptedBytes);
String message = new String(decryptedBytes, CHARSET);
log("message", message);
return message;
} catch (UnsupportedEncodingException e) {
if (DEBUG_LOG_ENABLED)
Log.e(TAG, "UnsupportedEncodingException ", e);
throw new GeneralSecurityException(e);
}
}
public static byte[] decrypt(final SecretKeySpec key, final byte[] iv, final byte[] decodedCipherText)
throws GeneralSecurityException {
final Cipher cipher = Cipher.getInstance(AES_MODE);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
byte[] decryptedBytes = cipher.doFinal(decodedCipherText);
log("decryptedBytes", decryptedBytes);
return decryptedBytes;
}
private static void log(String what, byte[] bytes) {
if (DEBUG_LOG_ENABLED)
Log.d(TAG, what + "[" + bytes.length + "] [" + bytesToHex(bytes) + "]");
}
private static void log(String what, String value) {
if (DEBUG_LOG_ENABLED)
Log.d(TAG, what + "[" + value.length() + "] [" + value + "]");
}
private static String bytesToHex(byte[] bytes) {
final char[] hexArray = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
'9', 'A', 'B', 'C', 'D', 'E', 'F'};
char[] hexChars = new char[bytes.length * 2];
int v;
for (int j = 0; j < bytes.length; j++) {
v = bytes[j] & 0xFF;
hexChars[j * 2] = hexArray[v >>> 4];
hexChars[j * 2 + 1] = hexArray[v & 0x0F];
}
return new String(hexChars);
}
private AESCrypt() {
}
}
答案 0 :(得分:1)
您可以将IV更改为所需的16字节值。您可以看到静态IV(错误想法)在类级别定义为0x00
* 16.您可以将该字节数组替换为另一个值,原始字节或已解码十六进制或Base64值等。
您应该为每个加密操作提供唯一且不可预测的IV,并将IV与密文一起传递以用于解密。 IV不需要受到保护或加密,并且可以与密文一起明确地传播。