Develop Reference

Convert AES encryption java to Python

I hava Java code that do AES encryption, and i would like to convert it so it work in python. This is a main class, i made initVector constants so it would be easier to see if it work:
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.*;
import java.io.BufferedWriter;
public class test {
public static void main(String [] args)
{
String ss = "pUypiz-7hJ0y_JtpKWaydp";
String url = "";
String toBeEncrypted = "";
String initVector = "IqtY8jgALtjZNLM5";
String encodedInitVector = Encryptor.encodeB64mod(initVector.getBytes());
toBeEncrypted = "ch21979714702=put";
ss = Encryptor.decodeB64Mod(ss);
url = "i=" + encodedInitVector + "\n&a=" + Encryptor.encrypt(initVector, ss, toBeEncrypted);
System.out.println(url);
}
}
And this is Encryptor class:
import android.util.Base64;
import java.util.Random;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.io.IOUtils;
import java.util.*;
public class Encryptor {
public static String encrypt(String initVector, String key, String clearText) {
try {
byte[] value = clearText.getBytes("UTF-8");
IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
SecretKeySpec skeySpec = new SecretKeySpec(Base64.decode(key, 0), "AES");
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
cipher.init(1, skeySpec, iv);
return encodeB64mod(cipher.doFinal(value));
} catch (Exception ex) {
ex.printStackTrace();
return "";
}
}
public static String encodeB64mod(byte[] bytes) {
return Base64.encodeToString(bytes, 2).replace('+', '-').replace(IOUtils.DIR_SEPARATOR_UNIX, '_').replace("=", "");
}
}
I tried to make it work in python but i am doing something wrong
EDIT:
import base64
from Crypto.Cipher import AES
from Crypto import Random
raw ='ch21979714702=put'.encode('utf-8')
key = 'pUypiz-7hJ0y_JtpKWaydp' #should be conveted to hex
iv = b'IqtY8jgALtjZNLM5'
cipher = AES.new( key, AES.MODE_CBC, iv )
print (base64.b64encode( cipher.encrypt( raw ) ).decode('utf-8') )

You are requiring base64url decoding, which isn't the generic base 64 encoding: it replaces + with - and / with _. This is why the reverse replacement is performed in Java.
Here is the correct way to decode it. Please upvote it and downvote any answers that do not include the replacement characters or final padding with the = character.

The problem was in Python was that you need to use padding
from Crypto.Util import Padding
Padding.pad(raw, 16, style='pkcs7')
https://www.pycryptodome.org/en/latest/src/util/util.html
Unlike in java in Python you need to add that you want to use padding.

Regeneration of SecretKey results in different key in java

I am trying to create an Encryption Program. However, The problem is when I am trying to Regenerate the SecretKey, I get different key which is not the same as the encryption key.
Here is my code snippet which I am using for testing purpose.`
import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
import java.util.*;
import java.io.*;
import java.nio.charset.StandardCharsets;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
class Test
{
static void My_Get_Key() throws Exception
{
String temp;
File f=new File("/home/mandar/Desktop/key.txt");
Scanner sc=new Scanner(f);
temp=sc.nextLine();
byte[] sk=Base64.decode(temp);
//byte[] sk=temp.getBytes();
//byte[] sk=temp.getBytes(StandardCharsets.ISO_8859_1);
SecretKey OriginalKey=new SecretKeySpec(sk,0,sk.length,"AES");
System.out.println("Decrypt Key is "+OriginalKey.toString());
//return OriginalKey;
}
static void My_Key_Generate() throws Exception
{
KeyGenerator key=KeyGenerator.getInstance("AES");
key.init(128);
SecretKey sk=key.generateKey();
System.out.println("Encrypt Key is "+sk.toString());
BufferedWriter wt = new BufferedWriter(new FileWriter("/home/mandar/Desktop/key.txt"));
String KeyString =sk.toString();
byte[] bytekey= KeyString.getBytes();
String WriteKey= Base64.encode(bytekey);
wt.write(sk.toString());
wt.flush();
wt.close();
//return sk;
}
public static void main(String[] args) throws Exception
{
My_Key_Generate();
My_Get_Key();
}
}
please Help.
PS: I am trying to store the generated key by converting it into string and writing it into a file and using the same file to retrieve the string and regenerate the key again.

The problem is that "sk.toString()" does not provide the contents of the key.
You need to call "sk.getEncoded()". Please note that it will return a byte array, not an String.
Write the contents of that byte array to the file and read it back.
Try with this modified code that uses "getEncoded()":
import java.util.*;
import java.nio.file.Files;
import java.nio.file.Paths;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
class Test {
static void My_Get_Key() throws Exception {
byte[] sk = Files.readAllBytes(Paths.get("/home/mandar/Desktop/key.txt"));
SecretKey OriginalKey = new SecretKeySpec(sk, 0, sk.length, "AES");
System.out.println("Decrypt Key is " + Arrays.toString(OriginalKey.getEncoded()));
}
static void My_Key_Generate() throws Exception {
KeyGenerator key = KeyGenerator.getInstance("AES");
key.init(128);
SecretKey sk = key.generateKey();
System.out.println("Encrypt Key is " + Arrays.toString(sk.getEncoded()));
Files.write(Paths.get("/home/mandar/Desktop/key.txt"), sk.getEncoded());
}
public static void main(String[] args) throws Exception {
My_Key_Generate();
My_Get_Key();
}
}

How to sign signature data using bouncy castle?

**This is my code to sign a String.</br>**
package my.package;
import java.io.FileInputStream;
import java.security.Key;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.Security;
import java.security.Signature;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.List;
import org.bouncycastle.cert.jcajce.JcaCertStore;
import org.bouncycastle.cms.CMSProcessableByteArray;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.CMSSignedDataGenerator;
import org.bouncycastle.cms.CMSTypedData;
import org.bouncycastle.cms.jcajce.JcaSignerInfoGeneratorBuilder;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.operator.ContentSigner;
import org.bouncycastle.operator.jcajce.JcaContentSignerBuilder;
import org.bouncycastle.operator.jcajce.JcaDigestCalculatorProviderBuilder;
import org.bouncycastle.util.Store;
import sun.misc.BASE64Encoder;
public class SignMessage {
static final String KEYSTORE_FILE = "keys/certificates.p12";
static final String KEYSTORE_INSTANCE = "PKCS12";
static final String KEYSTORE_PWD = "test";
static final String KEYSTORE_ALIAS = "Key1";
public static void main(String[] args) throws Exception {
String text = "This is a message";
Security.addProvider(new BouncyCastleProvider());
KeyStore ks = KeyStore.getInstance(KEYSTORE_INSTANCE);
ks.load(new FileInputStream(KEYSTORE_FILE), KEYSTORE_PWD.toCharArray());
Key key = ks.getKey(KEYSTORE_ALIAS, KEYSTORE_PWD.toCharArray());
//Sign
PrivateKey privKey = (PrivateKey) key;
Signature signature = Signature.getInstance("SHA1WithRSA", "BC");
signature.initSign(privKey);
signature.update(text.getBytes());
//Build CMS
X509Certificate cert = (X509Certificate) ks.getCertificate(KEYSTORE_ALIAS);
List certList = new ArrayList();
CMSTypedData msg = new CMSProcessableByteArray(signature.sign());
certList.add(cert);
Store certs = new JcaCertStore(certList);
CMSSignedDataGenerator gen = new CMSSignedDataGenerator();
ContentSigner sha1Signer = new JcaContentSignerBuilder("SHA1withRSA").setProvider("BC").build(privKey);
gen.addSignerInfoGenerator(new JcaSignerInfoGeneratorBuilder(new JcaDigestCalculatorProviderBuilder().setProvider("BC").build()).build(sha1Signer, cert));
gen.addCertificates(certs);
CMSSignedData sigData = gen.generate(msg, false);
FileOutputStream sigfos = new FileOutputStream("D:\\SBI-DATA\\file\\signature_1.txt");
sigfos.write(Base64.encodeBase64(sp.getEncoded()));
sigfos.close();
}
}
Now, the EnvelopedData output will be used in the process to verify the signature by this way:
import java.security.Security;
import java.security.cert.X509Certificate;
import java.util.Collection;
import java.util.Iterator;
import org.bouncycastle.cert.X509CertificateHolder;
import org.bouncycastle.cert.jcajce.JcaX509CertificateConverter;
import org.bouncycastle.cms.CMSSignedData;
import org.bouncycastle.cms.SignerInformation;
import org.bouncycastle.cms.SignerInformationStore;
import org.bouncycastle.cms.jcajce.JcaSimpleSignerInfoVerifierBuilder;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.util.Store;
import org.bouncycastle.util.encoders.Base64;
public class VerifySignature {
public static void main(String[] args) throws Exception {
File p7s = new File("D:\\SBI-DATA\\file\\signature_2.txt") ;
int size = ((int) p7s.length());
byte[] sig = new byte[size];
File f = new File("D:\\SBI-DATA\\file\\plain.txt") ;
int sizecontent = ((int) f.length());
byte[] Data_Bytes = new byte[sizecontent];
Security.addProvider(new BouncyCastleProvider());
CMSSignedData signedData = new CMSSignedData(new CMSProcessableByteArray(Data_Bytes), sig);
Store store = signedData.getCertificates();
SignerInformationStore signers = signedData.getSignerInfos();
Collection c = signers.getSigners();
Iterator it = c.iterator();
while (it.hasNext()) {
SignerInformation signer = (SignerInformation) it.next();
Collection certCollection = store.getMatches(signer.getSID());
Iterator certIt = certCollection.iterator();
X509CertificateHolder certHolder = (X509CertificateHolder) certIt.next();
X509Certificate certFromSignedData = new JcaX509CertificateConverter().setProvider(BC_PROVIDER).getCertificate(certHolder);
if (signer.verify(new JcaSimpleSignerInfoVerifierBuilder().setProvider(BC_PROVIDER).build(certFromSignedData))) {
System.out.println("Signature verified");
} else {
System.out.println("Signature verification failed");
}
}
}
}
Everything works good until signer.verify(..) due to the following Exception:
Exception in thread "main" org.bouncycastle.cms.CMSSignerDigestMismatchException: message-digest attribute value does not match calculated value
at org.bouncycastle.cms.SignerInformation.doVerify(Unknown Source)
at org.bouncycastle.cms.SignerInformation.verify(Unknown Source)
at my.package.VerifySignature.main(VerifySignature.java:64)
And I really don't know what I am doing wrong. Can someone please give me a hint of what is happening?

I think you are signing it twice, once directly using Signature and the other one using ContentSigner. You need only to sign the data, not the signature.
So the solution should be to replace signature.sign() with text.getBytes(), or text.getBytes(StandardCharsets.UTF_8) if you want to explicitly define a character set for text instead of using some system default.

Java AES 256 CBC mode not working propery

Here's a ruby code to do AES in ECB and CBC:
require 'openssl'
require 'base64'
def encrypt(data, key, cipher_type)
aes = OpenSSL::Cipher::Cipher.new(cipher_type)
key = key.ljust(32, "\0")
aes.encrypt
aes.key = key
Base64.encode64(aes.update(data) + aes.final).tr("\n","")
end
puts encrypt("XJ5QJSVMKZGBOQO7HMSIJO5BERW2OYWDVNPM3BH32NLSWUCNJ4FIP3BML7EKUBNO", "000000", 'AES-256-ECB')
puts encrypt("XJ5QJSVMKZGBOQO7HMSIJO5BERW2OYWDVNPM3BH32NLSWUCNJ4FIP3BML7EKUBNO", "000000", 'AES-256-CBC')
And here's the Java Equivalent:
import org.apache.commons.codec.binary.Base64;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.util.Arrays;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
public class AESTest
{
public static void main(String [] args)
{
System.out.println(AESEncryptToBase64("AES/ECB/PKCS5padding", "000000", "XJ5QJSVMKZGBOQO7HMSIJO5BERW2OYWDVNPM3BH32NLSWUCNJ4FIP3BML7EKUBNO"));
System.out.println(AESEncryptToBase64("AES/CBC/PKCS5padding", "000000", "XJ5QJSVMKZGBOQO7HMSIJO5BERW2OYWDVNPM3BH32NLSWUCNJ4FIP3BML7EKUBNO"));
}
/**
*
* #param secret
* #param cleartext
* #return encrypted b64 string
*/
public static String AESEncryptToBase64(String cypher, String secret, String clearText) {
byte[] rawKey = new byte[32];
java.util.Arrays.fill(rawKey, (byte) 0);
byte[] secretBytes = secret.getBytes();
for(int i = 0; i &lt secretBytes.length; i++){
rawKey[i] = secretBytes[i];
}
SecretKeySpec skeySpec = new SecretKeySpec(rawKey, "AES");
try{
Cipher cipher = Cipher.getInstance(cypher);
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encryptedData = cipher.doFinal(clearText.getBytes());
if(encryptedData == null) return null;
// return "l";
return Base64.encodeBase64String(encryptedData);
} catch (Exception e){
e.printStackTrace();
}
return null;
}
}
COMPILE: commons jar: http://apache.mirrors.pair.com//commons/codec/binaries/commons-codec-1.7-bin.zip
$ javac -cp .:commons-codec-1.7.jar AESTest.java
RUN
$ ruby aestest.rb
hYnClaUD9brJfNpEp4YDH0l1Y/QBlGkclnVN8MObNZFsvykd2da8iT2pcwLftNfox1HK/KFWrdfXt0qhP0Aq/fudP1FPIhF3vUTOEDzJbiY=
hYnClaUD9brJfNpEp4YDH5xcdKI4W5soPmWMpU+NikmAEKGSZkDP3KaJVSqRyOHt3JlcoyQzPbuoHxPV6kw6GH/4atDrcmCwV5LacTp+mBg=
$ java -cp .:commons-codec-1.7.jar AESTest
hYnClaUD9brJfNpEp4YDH0l1Y/QBlGkclnVN8MObNZFsvykd2da8iT2pcwLftNfox1HK/KFWrdfXt0qhP0Aq/fudP1FPIhF3vUTOEDzJbiY=
kZZNkbxis/W9UtEgRkxakGH28QetvK4lbf/SxBLrNDYPkGnf3w4MwonOCsoi9FjLAQ34aElOJ3KUjm62fiYLWxwNiE/wls7AcQnXLD19ano=
Notice that ECB mode works exactly on both. But CBC mode is different. I ran this also on C and it turns out that Ruby is correct, Java is not.
What am I doing wrong in Java?

For CBC you need to provide an initialization vector, for example:
cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(new byte[16]));
have an if statement in your code and two different inits. The one for ECB is fine, and this one won't work with ECB.

java.lang.NoClassDefFoundError when adding a classpath

Code:
import org.apache.commons.codec.binary.Base64;
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.security.spec.InvalidKeySpecException;
import java.util.Arrays;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
public class AESTest
{
public static void main(String [] args)
{
String enc = AESEncryptToBase64("000000", "XJ5QJSVMKZGBOQO7HMSIJO5BERW2OYWDVNPM3BH32NLSWUCNJ4FIP3BML7EKUBNO");
System.out.println(enc);
}
/**
*
* #param secret
* #param cleartext
* #return encrypted b64 string
*/
public static String AESEncryptToBase64(String secret, String clearText) {
byte[] rawKey = new byte[32];
java.util.Arrays.fill(rawKey, (byte) 0);
byte[] secretBytes = secret.getBytes();
for(int i = 0; i &lt secretBytes.length; i++){
rawKey[i] = secretBytes[i];
}
SecretKeySpec skeySpec = new SecretKeySpec(rawKey, "AES");
try{
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encryptedData = cipher.doFinal(clearText.getBytes());
if(encryptedData == null) return null;
// return "l";
return Base64.encodeBase64String(encryptedData);
} catch (Exception e){
e.printStackTrace();
}
return null;
}
}
Compile And run:
$ javac -cp "commons-codec-1.7.jar" AESTest.java
$ java -cp "commons-codec-1.7.jar" AESTest
Exception in thread "main" java.lang.NoClassDefFoundError: AESTest
Caused by: java.lang.ClassNotFoundException: AESTest
Here's the apache-commons-codec:
http://apache.mirrors.pair.com//commons/codec/binaries/commons-codec-1.7-bin.zip

Include . into your classpath: java -cp ".:commons-codec-1.7.jar" AESTest
This will tell JVM to include classes from current folder to classpath