Javascript/NodeJS equivalent code for the Java code Cipher.doFinal(byte[])? - java

I am migrating some server-side Java code to a new NodeJS server.
I am looking for an equivalent method call in Javascript to Java's Cipher.doFinal(byte[])
Note that I can't use NodeJS Buffers because they don't support negative Byte values. So to do my encryption, I'll need a method that accepts an array of positive and negative numbers.
Here's all of what I currently have that is related to this problem:
Node JS / Javascript:
var crypto = require('crypto');
var cipher = crypto.createCipher('aes256',key);
Java (javax.crypto.Cipher):
Cipher cipher;
SecretKeySpec skeySpec = new SecretKeySpec(key, "AES");
try {
cipher = Cipher.getInstance("AES");
} catch (NoSuchAlgorithmException e) {
} catch (NoSuchPaddingException e) {
}try {
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
} catch (InvalidKeyException e) {
}
later in the Java code, I call this method where Iv represents Initialization Vector:
byte[] newIv = cipher.doFinal(myIv);
How can I get the same result in JavaScript as I do in the doFinal Java method?

Byte handling
You can use NodeJS buffers. The byte arrays in Java may just consist of signed bytes, but those bytes are not handled any differently from unsigned bytes. Only the value of the actual bits matter. If you need to treat bytes directly, it is often best to use hexadecimals instead. You can convert to an positive integer value by performing b & 0xFF and you can do the opposite by performing (byte) b.
You could of course also do something similar in NodeJS to make NodeJS handle signed numbers, but it is common to treat keys, IV's etc. as unsigned.
Cipher selection
Now for the Java AES encryption, you are using the unsafe "AES/ECB/PKCS5Padding" mode, as the Oracle Java JCE provider defaults to ECB mode of encryption and PKCS#7 padding (incorrectly named "PKCS5Padding" by Java). ECB does not use an IV, so you can ignore the value of the IV. Strangely enough, you do have to use crypto.createCipheriv(algorithm, key, iv) as the crypto.createCipher(algorithm, password) uses a password instead of a key. Of course you should also use algorithm "AES-256-ECB" for NodeJS/OpenSSL - if your key is indeed 256 bits in size.

Turns out you can place an empty IV as follows:
var cipher = require('crypto').createCipheriv('aes-256'ecb', key, '');
As for the replacement method, simply store your old IV temporarily as a new IV and then attempt to update that new IV using the old one. Here's how it would look like in NodeJS using some of the above code on Initialization Vectors created as buffers:
var newIV = oldIV.slice();
newIV = cipher.update(newIV);
oldIV = newIV;

Related

How to convert crypto from java to nodejs

I have following code in Java.
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
secureRandom.setSeed(password.getBytes());
kgen.init(INIT_LENGTH, secureRandom);
SecretKey secretKey = kgen.generateKey();
byte[] enCodeFormat = secretKey.getEncoded();
SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
Cipher cipher = Cipher.getInstance("AES");
byte[] byteContent = content.getBytes("utf-8");
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] result = cipher.doFinal(byteContent);
return result;
I need to implement it in JavaScript/Node.js
I don't know how to implement it in JavaScript from secretString to key generated by KeyGenerator
from the comment section:
This is my code:
function encodeDesCBC( textToEncode, keyString, ivString ) {
const key = Buffer.from(keyString.substring(0, 8), 'utf8')
const iv = Buffer.from(ivString.substring(0, 8), 'utf8')
const cipher = crypto.createCipheriv('aes-128-cbc', key, iv)
let c = cipher.update(textToEncode, 'utf8', 'base64')
c += cipher.final('base64')
return base64url.escape(c)
}
My problem is secureRandom and KeyGenerator. I do not know how to implement it in nodejs
I don't know Java, but your usage looks somewhat weak, there are algorithms like PBKDF2 (which is old and discouraged now) and scrypt which do a much better job at turning human passwords into keying material. I'm also not sure where your IV is coming from in your Java code. Exactly replicating the Java code would be somewhat difficult as you'd need to know how your version of Java was implemented, and hence how the bytes passed to setSeed actually get turned into a key.
Node's Crypto module, as far as I can tell, assumes you know how long the keys are supposed to be. In the case of AES 128 in CBC mode, this would be 128 bits (i.e. 16 bytes) for both the key and IV.
Assuming you wanted to use things built into the Crypto module (argon2 would be recommended if you could relax this restriction) then you'd do something like:
const crypto = require('crypto');
const password = 'passw0rd';
const scrypt_salt = crypto.randomBytes(16);
const key = crypto.scryptSync(password, scrypt_salt, 16);
which would leave you with a suitable value in key, then you'd encrypt with:
const plaintext = 'the plain text to encode';
const iv = crypto.randomBytes(16);
const cipher = crypto.createCipheriv('aes-128-cbc', key, iv);
const ciphertext = Buffer.concat([
cipher.update(plaintext),
cipher.final(),
]);
and you could encode to Base64 with ciphertext.toString('base64').
Note that to be able to decrypt this, you'd need the scrypt_salt, iv, and ciphertext.
When you encrypt something using AES, there is always a "mode" in play. In your Java code you don't specify a mode explicitly - Cipher.getInstance("AES"). When you do not specify a mode, the default mode in Java is "ECB" which is the most insecured mode anyway.
In your NodeJs code, you're using "CBC" mode which is a altogether different mode.
Neither "ECB", nor "CBC" are considered secured enough. As of today, usually, the recommended mode is the GCM mode.
To generate a key from a password, ideally a "key derivation function" should be used. The 4 key derivation functions recommended by OWASP are: PBKDF2, Scrypt, Bcrypt and Argon2.
In your Java code, the password is used as a seed for the pseudo random number generator class SecureRandom. That's a little bit bizarre because even if you give the same password to your function, it will produce different key in different run. Yes, SecureRandom is also used to generate key. But if the requirement is to generate a key from a password, a key derivation function, as mentioned above, shoul be used. Both the approaches are shown in the following StackOverflow answer with detailed explanation. However, it uses "GCM" mode. But as long as you understand the concepts, you can use any mode of your choice.
https://stackoverflow.com/a/53015144/1235935
Similarly, you'll find the same implementation in NodeJs in the following StackOverflow answer:
https://stackoverflow.com/a/53573115/1235935
To further understand AES in general, you may want to go through the following StackOverflow answer:
https://stackoverflow.com/a/43779197/1235935

BadPaddingException: Given final block not properly padded due to different java version

I java 8 installed on client side where I am encrypting my data file using the below technique
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, key);
outputStream = new CipherOutputStream(new FileOutputStream(encryptedFile), cipher);
And now i am decrypting on server side where i have Java 7 installed as per the code below.
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, publicKey);
inputStream = new CipherInputStream(new FileInputStream(encryptedFile), cipher);
outputStream = new FileOutputStream(decryptedFileName);
Doing so give me below error
Caused by: java.io.IOException: javax.crypto.BadPaddingException: Given final block not properly padded
at javax.crypto.CipherInputStream.getMoreData(CipherInputStream.java:115) [jce.jar:1.7.0_71]
at javax.crypto.CipherInputStream.read(CipherInputStream.java:233) [jce.jar:1.7.0_71]
at javax.crypto.CipherInputStream.read(CipherInputStream.java:209) [jce.jar:1.7.0_71]
Same code works fine when i have same java version (1.7) installed on both side.
How can we fix this so that without changing the java version either of the side
There are a number of possible causes for this issue:
You don't specify how you are getting/generating the key. If your JREs differ in their possession/absence of the JCE Unlimited Strength Jurisdiction Policies, one will support 256-bit AES encryption and the other will only support 128-bit. If you are generating a key based on the available key lengths, this could be causing the keys not to match. Meanwhile, both of your Java 7 environments may have the same level policies installed.
You are not specifying the block cipher mode of operation or padding scheme on either side of the system -- I recommend an AEAD mode like GCM, EAX, or CCM (CTR + CBC-MAC) in conjunction with NoPadding, but even CBC/PKCS5Padding or CTR/NoPadding are better than the default AES/ECB/PKCS5Padding that you will get just by invoking Cipher.getInstance("AES").
You don't explain how you are encoding the cipher text before persisting it and then deserializing it for decryption. Without a safe encoding scheme like hexadecimal or Base64, you may (read: eventually will) encounter encoding issues working with raw binary values.
Once you change from ECB to another mode of operation, you will need to provide the initialization vector (IV) for both encryption and decryption, and transmit the IV alongside the cipher text. The IV does not need to be encrypted in any way, but it must be unique and non-predictable for each message encrypted with the same key. As it is always the block size of the cipher (fixed at 16 bytes/128 bits for AES), simply prepend the cipher text with the IV value and then split it for decryption.
AES (and all symmetric cryptography) uses the same key for encryption and decryption -- there are no public and private keys involved. It could just be a naming issue, but the fact that you are trying to decrypt with publicKey may indicate the wrong key being used. You should verify that both the encryption and decryption keys are byte-identical (same length (16, 24, or 32 bytes) and equal). ECB "decryption" will always "succeed" if the cipher text is an exact multiple of the block size (16 bytes). Then the padding is verified. If you attempt to decrypt a message with the wrong key, you will often (255/256 times) get a padding error. The other case is that the last byte decrypts to 0x01, which is a valid padding value for PKCS #5/#7, so it won't detect a padding error.
Demonstration that AES/ECB/PKCS5Padding is the default on Java 8 (1.8.0_101):
#Test
public void testCipherGetInstanceShouldDefaultToECB() throws Exception {
// Arrange
final String PLAINTEXT = "This is a plaintext message."
final SecretKey key = new SecretKeySpec(Hex.decodeHex("0123456789ABCDEFFEDCBA9876543210" as char[]), "AES")
Cipher unspecified = Cipher.getInstance("AES")
final Cipher EXPECTED_CIPHER = Cipher.getInstance("AES/ECB/PKCS5Padding")
unspecified.init(Cipher.ENCRYPT_MODE, key)
EXPECTED_CIPHER.init(Cipher.DECRYPT_MODE, key)
// Act
byte[] cipherBytes = unspecified.doFinal(PLAINTEXT.getBytes(StandardCharsets.UTF_8))
logger.info("Cipher text: ${Hex.encodeHexString(cipherBytes)}")
// Assert
byte[] recoveredBytes = EXPECTED_CIPHER.doFinal(cipherBytes)
String recovered = new String(recoveredBytes, StandardCharsets.UTF_8)
assert recovered == PLAINTEXT
}

Compatible AES algorithm for Java and Javascript

I need to encrypt some values in Java application using AES algorithm, and decrypt the same in my Javascript module of my application.
I saw some examples over the internet but it seems there's some differences in compatibility.
like below issue :
AES encryption in javascript and decrypting in java
Can someone please point me some code examples to solve this issue.
Thanks.
AES is an exactly specified algorithm, so all AES implementations must be "compatible". Having said that, AES is a variable-key-length block-cipher, operating on 128-bit blocks. To actually use this in a piece of software, you have to make a bunch of other choices: how to deal with input consisting of more than 1 block (this is called the "mode"), in some modes you need an initialization vector, you need to deal with input not consisting of an exact number of blocks (padding), how to encode characters into bytes, and how to represent bytes in a context (like a source file) that doesn't support that. All those things need to be compatible.
Below is a tested example. It uses the standard Java crypto functions (and Apache Commons Codec), and JavaScript crypto library crypto-js. Choices are as follows: 128-bit key, cipher-block-chaining mode (which needs an initialization vector), PKCS5/7 padding, UTF-8 for character encoding, Base64 to represent byte arrays.
This piece of Java will output Base64-encoded ciphertext:
String plainText = "Hello, World! This is a Java/Javascript AES test.";
SecretKey key = new SecretKeySpec(
Base64.decodeBase64("u/Gu5posvwDsXUnV5Zaq4g=="), "AES");
AlgorithmParameterSpec iv = new IvParameterSpec(
Base64.decodeBase64("5D9r9ZVzEYYgha93/aUK2w=="));
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, iv);
System.out.println(Base64.encodeBase64String(cipher.doFinal(
plainText.getBytes("UTF-8"))));
This piece of JavaScript correctly decrypts it:
<script src="http://crypto-js.googlecode.com/svn/tags/3.1.2/build/rollups/aes.js"></script>
<script>
var encrypted = CryptoJS.enc.Base64.parse('3Q7r1iqtaRuJCo6QHA9/GhkTmbl4VkitV9ZsD3K2VB7LuBNg4enkJUA1cF8cHyovUH2N/jFz3kbq0QsHfPByCg==');
var key = CryptoJS.enc.Base64.parse('u/Gu5posvwDsXUnV5Zaq4g==');
var iv = CryptoJS.enc.Base64.parse('5D9r9ZVzEYYgha93/aUK2w==');
document.write(CryptoJS.enc.Utf8.stringify(CryptoJS.AES.decrypt(
{ ciphertext: encrypted },
key,
{ mode: CryptoJS.mode.CBC, padding: CryptoJS.pad.Pkcs7, iv: iv, })));
</script>

IVParameter Spec Problem in Java

I am currently devloping a Windows application using C# and looking at developing a mobile app using Java.
The windows software and the mobile app will work together, the windows app will store information and encrypt certain information before storing it in an online database.
The mobile app will pull the information from the online database and will need to decrypt the encrypted string that is retrieved from the datbase.
The encryption method I am using in C# is below
byte[] clearTextBytes = Encoding.UTF8.GetBytes(encryptionString);
SymmetricAlgorithm rijn = SymmetricAlgorithm.Create();
MemoryStream ms = new MemoryStream();
byte[] rgbIV = Encoding.ASCII.GetBytes("ryojvlzmdalyglrj");
byte[] key = Encoding.ASCII.GetBytes("hcxilkqbbhczfeultgbskdmaunivmfuo");
CryptoStream cs = new CryptoStream(ms, rijn.CreateEncryptor(key, rgbIV), CryptoStreamMode.Write);
cs.Write(clearTextBytes, 0, clearTextBytes.Length);
cs.Close();
return Convert.ToBase64String(ms.ToArray());
The Windows method works fine.
The code I am using in Java is as follows:
KeySpec ks = new DESKeySpec("hcxilkqbbhczfeultgbskdmaunivmfuo".getBytes("UTF-8"));
SecretKey key = SecretKeyFactory.getInstance("DES").generateSecret(ks);
String ivString = "ryojvlzmdalyglrj";
byte[] ivByte = ivString.getBytes("UTF-8");
IvParameterSpec iv = new IvParameterSpec(ivByte);
//RC5ParameterSpec iv = new RC5ParameterSpec(ivByte);
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, iv);
byte[] encoded = cipher.doFinal(Base64.decodeBase64("iNtaFme3B/e6DppNSp9QLg=="));
Log.d("Decoded Password", encoded.toString());
As both methods need to encrypt and decrypt the same string together it has to use the same key and IV. The only problem that I am having is in the java method the IVParameterSpec is going into the catch with an error that says IV must be 8 bytes long.
How can I resolve this to ensure that I have the same IV as C#.
Thanks for the help
The problem is that you are encrypting (in C#) with AES (also known as Rjindael), but trying to decrypt in Java with DES. If you change your Java code to use AES then it should all work fine.
DES uses an 8-byte IV because it works on 64-bit blocks. AES uses a 16-byte IV because it works on 128-bit blocks.
You should also make sure you use the same character encoding. In C# you are using ASCII, but in java you're using UTF-8. In your case they will be the same, but you should really fix it now to prevent strange bugs in future. You can change the character set name in Java to "US-ASCII" and it'll work.
You have to use the same algorithm of course. The default algorithm is for .NET is AES, so that is what you should be using on the Java side as well.

Using openssl encryption with Java

I have a legacy C++ module that offers encryption/decryption using the openssl library (DES encryption). I'm trying to translate that code into java, and I don't want to rely on a DLL, JNI, etc...
C++ code looks like:
des_string_to_key(reinterpret_cast<const char *>(key1), &initkey);
des_string_to_key(reinterpret_cast<const char *>(key2), &key);
key_sched(&key, ks);
// ...
des_ncbc_encrypt(reinterpret_cast<const unsigned char *>(tmp.c_str()),
reinterpret_cast< unsigned char *>(encrypted_buffer), tmp.length(), ks, &initkey,
DES_ENCRYPT);
return base64(reinterpret_cast<const unsigned char *>(encrypted_buffer), strlen(encrypted_buffer));
Java code looks like:
Cipher ecipher;
try {
ecipher = Cipher.getInstance("DES");
SecretKeySpec keySpec = new SecretKeySpec(key, "DES");
ecipher.init(Cipher.ENCRYPT_MODE, keySpec);
byte[] utf8 = password.getBytes("UTF8");
byte[] enc = ecipher.doFinal(utf8);
return new sun.misc.BASE64Encoder().encode(enc);
}
catch {
// ...
}
So I can do DES encryption in Java pretty easily, but how can I get the same result as with the above code with methods that are completely different? What bothers me in particular is the fact that the C++ version uses 2 keys while the Java version uses only 1 key.
The answer about DES in CBC mode is quite satisfying but I can't get it to work yet.
Here are more details about the original code:
unsigned char key1[10]= {0};
unsigned char key2[50]= {0};
int i;
for (i=0;i<8;i++)
key1[i] = 31+int((i*sqrt((double)i*5)))%100;
key1[9]=0;
for (i=0;i<48;i++)
key2[i] = 31+int((i*i*sqrt((double)i*2)))%100;
key2[49]=0;
...
// Initialize encrypted buffer
memset(encrypted_buffer, 0, sizeof(encrypted_buffer));
// Add begin Text and End Text to the encrypted message
std::string input;
const char beginText = 2;
const char endText = 3;
input.append(1,beginText);
input.append(bufferToEncrypt);
input.append(1,endText);
// Add padding
tmp.assign(desPad(input));
des_ncbc_encrypt(reinterpret_cast<const unsigned char *>(tmp.c_str()),
reinterpret_cast< unsigned char *>(encrypted_buffer), tmp.length(), ks, &initkey,
DES_ENCRYPT);
...
From what I've read, the key should be 56 (or 64, it's not clear to me) bits long, but here it's 48 bytes long.
I'm not an OpenSSL expert, but I'd guess the C++ code is using DES in CBC mode thus needing an IV (that's what the initKey probably is, and that's why you think you need two keys). If I'm right, you need to change your Java code to use DES in CBC mode too, then the Java code too will require an encryption key and an IV.
Also, keep in mind that you really shouldn't use sun.misc.* classes in your code. This could break in other VMs as these are not public APIs. Apache Commons Codecs (among others) have implementations of Base64 that don't bear this problem.
I'm not really sure why single DES would ever use multiple keys. Even if you were using Triple-DES, I believe you would use a single key (with more bytes of data) rather than using separate keys with the Java Cryptography API.
The algorithms should match; if you're getting different results it may have to do with the way you're handling the keys and the text. Also keep in mind that Java characters are 2 bytes long, which C++ chars are 1 byte, so that may have something to do with it.

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