I want to do aes-128-cbc encryption in JAVA and Linux, but it keeps giving me different results.
For example I want to decode string "my.txt". In Linux I do it in this way:
echo -n my.txt | openssl aes-128-cbc -K 6f838655d1bd6312b224d3d1c8de4fe1 -iv 9027ce06e06dbc8b -a
I also encode it to base64 and it's giving me this result: 86M5fwdUpQ3tbFrz0ddHJw==
In Java I use this method:
public static String encrypt(String key, String initVector, String value) {
try {
IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
byte[] encrypted = cipher.doFinal(value.getBytes());
System.out.println("encrypted string: "
+ Base64.encodeToString(encrypted, Base64.DEFAULT));
return Base64.encodeToString(encrypted, Base64.DEFAULT);
} catch (Exception ex) {
ex.printStackTrace();
}
return null;
}
And with same data it gives me completely different result: vgk6yxCrQ5iLFvHxMtQO7w==
I also tried to use aes-256-cbc with 32-symbol length iv. In Linux I use aes-256-cbc and in Android I use Spongy Castle library for this purpose, but it give different results too.
What I did wrong? Or maybe you have suggestion to choose different cross-platform algorithm to encryption.
The -K and -iv parameters expect Hex-encoded strings. Your key is 32 characters long, so it is 16 bytes or 128 bits. Your IV is 16 characters long, so it is 8 bytes or 64 bits. An IV for AES/CBC must be exactly 128 bits long. If it is not, then it must be padded somehow. Your IV is most likely padded with 0x00 bytes to get to 128 bits. You would have to do the same in Java.
The other issue is that you're treating the Hex-encoded key and IV as text, which means that you're treating it as a 256 bit key and 128 bit IV in Java. Which is probably not what you want. You have to decode the strings from Hex before use.
Let's use an imaginary implementation of byte[] fromHex(String hexStr):
byte[] ivBytes = new byte[16];
byte[] ivBytesShort = fromHex(initVector);
System.arraycopy(ivBytesShort, 0, ivBytes, 0, ivBytesShort.length);
IvParameterSpec iv = new IvParameterSpec(ivBytes);
SecretKeySpec skeySpec = new SecretKeySpec(fromHex(key), "AES");
Related
I am in a situation where a JSON is encrypted in PHP's openssl_encrypt and needs to be decrypted in JAVA.
$encrypted = "...ENCRYPTED DATA...";
$secretFile = "/path/to/secret/saved/in/text_file";
$secret = base64_decode(file_get_contents($secretFile));
var_dump(strlen($secret)); // prints : int(370)
$iv = substr($encrypted, 0, 16);
$data = substr($encrypted, 16);
$decrypted = openssl_decrypt($data, "aes-256-cbc", $secret, null, $iv);
This $decrypted has correct data which is now decrypted.
Now, the problem is when I try to do same things in Java it doesn't work :(
String path = "/path/to/secret/saved/in/text";
String payload = "...ENCRYPTED DATA...";
StringBuilder output = new StringBuilder();
String iv = payload.substring(0, 16);
byte[] secret = Base64.getDecoder().decode(Files.readAllBytes(Paths.get(path)));
String data = payload.substring(16);
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeySpec secretKeySpec = new SecretKeySpec(secret, "AES");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv.getBytes(), 0, cipher.getBlockSize());
cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec); // This line throws exception :
cipher.doFinal(data.getBytes(StandardCharsets.UTF_8));
Here it is:
Exception in thread "main" java.security.InvalidKeyException: Invalid AES key length: 370 bytes
at com.sun.crypto.provider.AESCrypt.init(AESCrypt.java:87)
at com.sun.crypto.provider.CipherBlockChaining.init(CipherBlockChaining.java:91)
at com.sun.crypto.provider.CipherCore.init(CipherCore.java:591)
at com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:346)
at javax.crypto.Cipher.init(Cipher.java:1394)
at javax.crypto.Cipher.init(Cipher.java:1327)
at com.sample.App.main(App.java:70)
I have already visited similar question like
AES-256 CBC encrypt in php and decrypt in Java or vice-versa
openssl_encrypt 256 CBC raw_data in java
Unable to exchange data encrypted with AES-256 between Java and PHP
and list continues.... but no luck there
btw, this is how encryption is done in PHP
$secretFile = "/path/to/secret/saved/in/text_file";
$secret = base64_decode(file_get_contents($secretFile));
$iv = bin2hex(openssl_random_pseudo_bytes(8));
$enc = openssl_encrypt($plainText, "aes-256-cbc", $secret, false, $iv);
return $iv.$enc;
and yes, I forgot to mention that my JRE is already at UnlimitedJCEPolicy and I can't change PHP code.
I am totally stuck at this point and can't move forward. Please help out.
EDIT#1
byte[] payload = ....;
byte[] iv = ....;
byte[] secret = ....; // Now 370 bits
byte[] data = Base64.getDecoder().decode(payload);
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
SecretKeySpec secretKeySpec = new SecretKeySpec(Arrays.copyOfRange(secret, 0, 32), "AES");
IvParameterSpec ivParameterSpec = new IvParameterSpec(iv, 0, cipher.getBlockSize());
cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec);
byte[] output = cipher.doFinal(data);
System.out.println(new String(output).trim());
Above snippet seems to be working with openssl_encrypt
EDIT#2
I am not sure if this is correct, but following is what I have done and encryption-decryption on both side are working fine.
Encrypt in PHP, Decrypt in JAVA use AES/CBC/NoPadding
Encrypt in JAVA, Decrypt in PHP use AES/CBC/PKCS5Padding
I won't provide a complete solution, but there are a few differences you should take care of
Encoding:
String iv = payload.substring(0, 16);
String data = payload.substring(16);
are you sure the IV and data are the same in Java and PHP (The IV is string?)? If the data are encrypted, they should be treated as a byte array, not string. Just REALLY make sure they are THE SAME (print hex/base64 in php and java)
For the IV you at the end call iv.getBytes(), but the locale encoding may/will corrupt your values. The String should be use only when it's really string (text). Don't use string for binaries.
Simply treat data and iv as byte[]
Key generation according to the openssl
AES key must have length of 256 bit for aes-256-cbc used. The thing is - openssl by default doesn't use the provided secret as a key (I believe it can, but I don't know how it is to be specified in PHP).
see OpenSSL EVP_BytesToKey issue in Java
and here is the EVP_BytesToKey implementation: https://olabini.com/blog/tag/evp_bytestokey/
you should generate a 256 bit key usging the EVP_BytesToKey function (it's a key derivation function used by openssl).
Edit:
Maarten (in the comments) is right. The key parameter is the key. Seems the PHP function is accepting parameter of any length which is misleading. According to some articles (e.g. http://thefsb.tumblr.com/post/110749271235/using-opensslendecrypt-in-php-instead-of) the key is trucated or padded to necessary length (so seems 370 bit key is truncated to length of 256 bits).
According to your example, I wrote fully working code for PHP and Java:
AesCipher class: https://gist.github.com/demisang/716250080d77a7f65e66f4e813e5a636
Notes:
-By default algo is AES-128-CBC.
-By default init vector is 16 bytes.
-Encoded result = base64(initVector + aes crypt).
-Encoded/Decoded results present as itself object, it gets more helpful and get possibility to check error, get error message and get init vector value after encode/decode operations.
PHP:
$secretKey = '26kozQaKwRuNJ24t';
$text = 'Some text'
$encrypted = AesCipher::encrypt($secretKey, $text);
$decrypted = AesCipher::decrypt($secretKey, $encrypted);
$encrypted->hasError(); // TRUE if operation failed, FALSE otherwise
$encrypted->getData(); // Encoded/Decoded result
$encrypted->getInitVector(); // Get used (random if encode) init vector
// $decrypted->* has identical methods
JAVA:
String secretKey = "26kozQaKwRuNJ24t";
String text = "Some text";
AesCipher encrypted = AesCipher.encrypt(secretKey, text);
AesCipher decrypted = AesCipher.decrypt(secretKey, encrypted);
encrypted.hasError(); // TRUE if operation failed, FALSE otherwise
encrypted.getData(); // Encoded/Decoded result
encrypted.getInitVector(); // Get used (random if encode) init vector
// decrypted.* has identical methods
I have a PHP encryption function. I need a java counter part for the same. Due to my limited knowledge in PHP I am unable to understand. Some one knows both the language, kindly help.
PHP code:
function encrypt($decrypted, $keyvalue) {
// Build a 256-bit $key which is a SHA256 hash of $keyvalue.
$key = hash('SHA256', $keyvalue, true);
// Build $iv and $iv_base64. We use a block size of 128 bits (AES compliant) and CBC mode. (Note: ECB mode is inadequate as IV is not used.)
srand(); $iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC), MCRYPT_RAND);
if (strlen($iv_base64 = rtrim(base64_encode($iv), '=')) != 22) return false;
// Encrypt $decrypted and an MD5 of $decrypted using $key. MD5 is fine to use here because it's just to verify successful decryption.
$encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $decrypted . md5($decrypted), MCRYPT_MODE_CBC, $iv));
// We're done!
return $iv_base64 . $encrypted;
}
Thanks in advance
Aniruddha
This should do it.
public static byte[] encrypt(byte[] decrypted, byte[] keyvalue) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException{
MessageDigest sha256 = MessageDigest.getInstance("SHA-256");
byte[] key = sha256.digest(keyvalue);
MessageDigest md5 = MessageDigest.getInstance("MD5");
byte[] checksum = md5.digest(decrypted);
//The length of the value to encrypt must be a multiple of 16.
byte[] decryptedAndChecksum = new byte[(decrypted.length + md5.getDigestLength() + 15) / 16 * 16];
System.arraycopy(decrypted, 0, decryptedAndChecksum, 0, decrypted.length);
System.arraycopy(checksum, 0, decryptedAndChecksum, decrypted.length, checksum.length);
//The remaining bytes of decryptedAndChecksum stay as 0 (default byte value) because PHP pads with 0's.
SecureRandom rnd = new SecureRandom();
byte[] iv = new byte[16];
rnd.nextBytes(iv);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
Cipher cipher = Cipher.getInstance("AES/CBC/NoPadding");
cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(key, "AES"), ivSpec);
byte[] encrypted = Base64.encodeBase64(cipher.doFinal(decryptedAndChecksum));
byte[] ivBase64 = Base64.encodeBase64String(iv).substring(0, 22).getBytes();
byte[] output = new byte[encrypted.length + ivBase64.length];
System.arraycopy(ivBase64, 0, output, 0, ivBase64.length);
System.arraycopy(encrypted, 0, output, ivBase64.length, encrypted.length);
return output;
}
The equivalent of MCRYPT_RIJNDAEL_128 and MCRYPT_MODE_CBC in java is AES/CBC/NoPadding. You also need a utility for Base64 encoding, the above code uses Base64 from the Apache Codec library.
Also, because the encryption key is 256 bits, you'll need the Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files. These can be downloaded from Oracle's website.
Finally, do heed ntoskrnl's warning. This encryption really could be better, don't copy-paste from the PHP manual.
I have "inherited" a Ruby on Rails app, and I must translate this app from Ruby to Java, and the most important thing, I don't have contact with the creator.
My problem is with the IV vector in AES-256 authentication. Ruby app uses AESCrypt gem to encrypt and decrypt user's password. It works fine, and I have already some thousands of users in DB.
The problem is when I try to do the same in Java (I've already updated JCE to allow 256bit key lenght). The Key and the IV are writen as binary strings in ruby source code (see bellow), and when I try to use it in Java I get a exception which say that the IV lenght must be 16 bytes long (I know that it must be 16 bytes long, but the binary string in Ruby has 32 characters).
Ruby code (works fine):
require 'openssl'
require 'digest/md5'
require 'base64'
module AESCrypt
KEY = "AB1CD237690AF13B6721AD237A"
IV = "por874hyufijdue7w63ysxwet4320o90"
TYPE = "AES-256-CBC"
def AESCrypt.key(key)
key = Digest::MD5.hexdigest(key)
key.slice(0..32)
end
# Encrypts a block of data given an encryption key and an
# initialization vector (iv). Keys, iv's, and the data returned
# are all binary strings. Cipher_type should be "AES-256-CBC",
# "AES-256-ECB", or any of the cipher types supported by OpenSSL.
# Pass nil for the iv if the encryption type doesn't use iv's (like
# ECB).
#:return: => String
#:arg: data => String
#:arg: key => String
#:arg: iv => String
#:arg: cipher_type => String
def AESCrypt.encrypt(data)
return nil if data.nil?
return data if data.blank?
aes = OpenSSL::Cipher::Cipher.new(TYPE)
aes.encrypt
aes.key = AESCrypt.key(KEY)
aes.iv = IV if IV != nil
result = aes.update(data) + aes.final
Base64.encode64(result)
end
end
and this is my Java code (it should do the same, seems that works with a 16 chars/bytes IV):
public static void main(String[] args) throws UnsupportedEncodingException {
String KEY = "AB1CD237690AF13B6721AD237A";
String IV = "por874hyufijdue7w63ysxwet4320o90";
SecretKeySpec key = generateKey(KEY);
String message = "password";
final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivSpec = new IvParameterSpec(IV.getBytes());
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
byte[] ciphedText = cipher.doFinal(message.getBytes());
String encoded = Base64.encodeBase64String(ciphedText);
System.out.println("ENCRYPTED text= " + encoded);
}
public static SecretKeySpec generateKey(final String password) throws NoSuchAlgorithmException, UnsupportedEncodingException {
final MessageDigest digest = MessageDigest.getInstance("MD5");
byte[] bytes = password.getBytes("UTF-8");
digest.update(bytes, 0, bytes.length);
byte[] key = digest.digest();
SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
return secretKeySpec;
}
And I'm getting this exception (obviously):
java.security.InvalidAlgorithmParameterException: Wrong IV length: must be 16 bytes long
at com.sun.crypto.provider.CipherCore.init(CipherCore.java:516)
at com.sun.crypto.provider.AESCipher.engineInit(AESCipher.java:339)
at javax.crypto.Cipher.implInit(Cipher.java:801)
at javax.crypto.Cipher.chooseProvider(Cipher.java:859)
at javax.crypto.Cipher.init(Cipher.java:1370)
at javax.crypto.Cipher.init(Cipher.java:1301)
at com.javi.test.security.Test.main(Test.java:129)
I guess my problem is the way I convert the IV java string in byte[]. I think that openSSL code in ruby is unpacking (or doing something internally) the 32 bytes of the IV to 16 bytes. I have tried a lot of things, but I'm going crazy.
Anyone had the same problem or figure out where could be my problem?
I have posted the encryption code but I hace the same issue with decryption.
Thanks in advance, I'll be very grateful with every answer. :)
First, your IV is not actually iv, IV should be HEX encoded, but you have ASCII string "por874hyufijdue7w63ysxwet4320o90", may be it is some how encoded?
Second, IV.getBytes() will transofr IV's each character to hex encoding like p = 0x70, o = 0x6F, r = 0x72, etc...
It is not a useful answer, but may be hint.
Actually IV must be the same length as block cipher single block length. You have 32 bytes long IV itself, if you make IV.getBytes() IV length should match the cipher block length
so i am working on this assignement where i'm suppposed to make my own CBC and CTR algorithms using the predefined aes functions, for now i seem to have a problem, the output's Size is always a Block more than the input (input 64 ,output 80 , and so on ) here's the code i'm using, with hexadecimal to bytes conversion and bytes to hex :
public static String encrypt(String PT,String skey) throws Exception, NoSuchPaddingException {
Cipher cipher = Cipher.getInstance("AES");
SecretKeySpec key = new SecretKeySpec(skey.getBytes("ascii"), "AES");
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] val = hexToBytes(PT);
byte[] encVal = cipher.doFinal(val);
return byteToString(encVal);
}
the conversion functions are perfectly working, the val size is n * 16 bytes and the encVal size is (n+1) * 16 bytes
This is due to padding.
Cipher.getInstance("AES");
uses provider-specific default values for the mode and padding. For JDK 6 & 7, this would default to AES/ECB/PKCS5Padding.
I have Perl code that decrypts a String and I want to do the same in Java. This is the Perl code:
my $c = Crypt::CBC->new( -key => $keyString, -cipher => 'Blowfish', -header => 'randomiv');
return $c->decrypt_hex($config->{encrypted_password})
This is my attempt at the Java code:
Cipher cipher = Cipher.getInstance("Blowfish/CBC/PKCS5Padding");
// setup an IV (initialization vector) that should be
// randomly generated for each input that's encrypted
byte[] iv = new byte[cipher.getBlockSize()];
new SecureRandom().nextBytes(iv);
IvParameterSpec ivSpec = new IvParameterSpec(iv);
// decrypt
SecretKey secretKey = new SecretKeySpec(Base64.decodeBase64(keyString), "Blowfish");
cipher.init(Cipher.DECRYPT_MODE, secretKey, ivSpec);
byte[] decrypted = cipher.doFinal(Base64.decodeBase64(input));
return Hex.encodeHexString(decrypted);
I'm getting:javax.crypto.BadPaddingException: Given final block not properly padded. But according to this, the Crypt CBC library uses PKCS5 as the default padding.
Also, am I doing the hex encoding at the end right?
One of the problems you have is that you generate a random IV instead of importing the one used for encryption. Do you have access to the IV used at encryption? Could it be at the start of the ciphertext?
I don't do Perl, so I'm not quite sure if my response is valid. Base64 is probably not the right decoding you're looking for.
For creating your SecretKeySpec, try doing something like:
SecretKey secretKey = new SecretKeySpec(keyString.getBytes("ASCII"), "Blowfish");
For decoding the text, check out Hex.decodeHex(char[]) which can be found at http://commons.apache.org/codec/apidocs/org/apache/commons/codec/binary/Hex.html ... so your code might look something like this:
byte[] decrypted = cipher.doFinal(Hex.decodeHex(input.toCharArray()));
String unencryptedStuff = new String(decrypted);