英文:
First 8 bytes is truncating in AES decryption in java where encryption is done in c#
问题
public static String encrypt(String clearText, String passphrase) {
String encryptedText = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, 1000, 256);
SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
IvParameterSpec iv = new IvParameterSpec(Arrays.copyOf(saltByte, 16));
cipher.init(Cipher.ENCRYPT_MODE, key, iv);
byte[] encryptedBytes = cipher.doFinal(clearText.getBytes());
encryptedText = Base64.getEncoder().encodeToString(encryptedBytes);
} catch (Exception ex) {
ex.printStackTrace();
}
return encryptedText;
}
public static String decrypt(String cipherText, String passphrase) {
String decryptedText = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, 1000, 256);
SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
IvParameterSpec iv = new IvParameterSpec(Arrays.copyOf(saltByte, 16));
cipher.init(Cipher.DECRYPT_MODE, key, iv);
byte[] decryptedBytes = cipher.doFinal(Base64.getDecoder().decode(cipherText));
decryptedText = new String(decryptedBytes);
} catch (Exception ex) {
ex.printStackTrace();
}
return decryptedText;
}
Please note that the provided Java code snippets are equivalent to the C# encryption and decryption functions you provided. However, make sure to properly handle exceptions and consider security best practices when implementing encryption and decryption in your application.
英文:
I am trying to decrypt the string which is encrypted in c# with same key length and vector.
JAVA CODE
public static void main(String[] args) {
// TODO Auto-generated method stub
String cum006333 = decrypt("h+VJ5or2yBFQYawNWXET11nekUzWYYVWk0/O2fHxoLNm60l3d3qQo2NJjGr3+zZP", "MYPRIVATE@KEY");
System.out.println(cum006333);
}
public static String decrypt(String cipherText, String passphrase) {
String s = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] bytes = Base64.getDecoder().decode(cipherText);
int keySize = 256;
int iterCount = 1000;
int ivLength = 16;
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
byte[] ivB = Arrays.copyOf(bytes, ivLength);
byte[] data = Arrays.copyOfRange(bytes,ivLength, bytes.length);
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, iterCount, keySize);
SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
IvParameterSpec iv = new IvParameterSpec(ivB);
cipher.init(Cipher.DECRYPT_MODE, key, iv);
byte[] original = cipher.doFinal(data);
s = new String(original);
System.out.println(s);
} catch (Exception ex) {
ex.printStackTrace();
}
return s;
}
}
expexted output is - Duplicate Request ID
output coming is - e Request Id
I need to encrypt the request in java and send to api where they will decrypt it and use it. So i want java equivalent of the below C# code..
please find C# code used for encrypting and decrypting below
public static string EncryptResponse(string clearText)
{
string EncryptionKey = System.Configuration.ConfigurationManager.AppSettings["SECRETMSG"].ToString();
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes rfcdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = rfcdb.GetBytes(32);
encryptor.IV = rfcdb.GetBytes(16);
using (MemoryStream mem = new MemoryStream())
{
using (CryptoStream cryp = new CryptoStream(mem, encryptor.CreateEncryptor(), CryptoStreamMode.Write))
{
cryp.Write(clearBytes, 0, clearBytes.Length);
cryp.Close();
}
clearText = Convert.ToBase64String(mem.ToArray());
}
}
return clearText;
}
public static string DecryptResponse(string cipherText)
{
string EncryptionKey = System.Configuration.ConfigurationManager.AppSettings["SECRETMSG"].ToString();
byte[] cipherBytes = Convert.FromBase64String(cipherText);
using (Aes encryptor = Aes.Create())
{
Rfc2898DeriveBytes rfcdb = new Rfc2898DeriveBytes(EncryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });
encryptor.Key = rfcdb.GetBytes(32);
encryptor.IV = rfcdb.GetBytes(16);
using (MemoryStream mem = new MemoryStream())
{
using (CryptoStream cryp = new CryptoStream(mem, encryptor.CreateDecryptor(), CryptoStreamMode.Write))
{
cryp.Write(cipherBytes, 0, cipherBytes.Length);
cryp.Close();
}
cipherText = Encoding.Unicode.GetString(mem.ToArray());
}
}
return cipherText;
}
答案1
得分: 1
很遗憾，你没有展示C#中的加密代码，这会直接指向解决方案，而不是争论和搜索。
你声称“截断”的原因不在于Java端（解密），而在于你的C#加密函数。很可能你对明文使用了UTF-16编码，而在Java端使用了标准编码（UTF-8）。
以下是稍微修改过的代码版本，其中为了确保所有数据具有正确的长度，添加了专门的输出。
观察“.doFinal”输出，我们可以看到一个值为（十六进制）“650020005200650071007500650073007400200049004400” - 每个字符之间有很多“x00”值，这明显是UTF-16编码，因此最终的字符串值不是“e Request Id”，而是“e R e q u e s t I D”。
将“new String”编码更改为“new String(original, StandardCharsets.UTF_16LE)”会得到“正确”的输出“e Request ID” - 但起始处的“Duplicat”在哪里？我相信你同样也是通过“Array-copying”获取密文的（base64编码）字符串，并且只复制密文的最后12个（或在UTF-16中为24个）字节，所以 - 我所相信的 - 你在C#端截断了密文。
以下是输出和修改后的代码行：
输出：
First 8 bytes is truncating in AES decryption in java where encryption is done in c#
cipherByte length: 48 data: 87e549e68af6c8115061ac0d597113d759de914cd6618556934fced9f1f1a0b366eb4977777a90a363498c6af7fb364f
ivB length: 16 data: 87e549e68af6c8115061ac0d597113d7
data length: 32 data: 59de914cd6618556934fced9f1f1a0b366eb4977777a90a363498c6af7fb364f
original length: 24 data: 650020005200650071007500650073007400200049004400
e R e q u e s t I D
e R e q u e s t I D
修改代码行：
s = new String(original);
改为
s = new String(original, StandardCharsets.UTF_16LE);
代码：
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.spec.KeySpec;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Base64;
public class mainSo {
public static void main(String[] args) {
System.out.println("First 8 bytes is truncating in AES decryption in java where encryption is done in c#");
String cipherstring = "h+VJ5or2yBFQYawNWXET11nekUzWYYVWk0/O2fHxoLNm60l3d3qQo2NJjGr3+zZP";
byte[] cipherByte = Base64.getDecoder().decode(cipherstring);
System.out.println("cipherByte length: " + cipherByte.length + " data: " + bytesToHex(cipherByte));
String cum006333 = decrypt(cipherstring, "KEY@CRISIL123");
System.out.println(cum006333);
}
public static String decrypt(String cipherText, String passphrase) {
String s = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] bytes = Base64.getDecoder().decode(cipherText);
int keySize = 256;
int iterCount = 1000;
int ivLength = 16;
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
byte[] ivB = Arrays.copyOf(bytes, ivLength);
byte[] data = Arrays.copyOfRange(bytes, ivLength, bytes.length);
System.out.println("ivB length: " + ivB.length + " data: " + bytesToHex(ivB));
System.out.println("data length: " + data.length + " data: " + bytesToHex(data));
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, iterCount, keySize);
SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
IvParameterSpec iv = new IvParameterSpec(ivB);
cipher.init(Cipher.DECRYPT_MODE, key, iv);
byte[] original = cipher.doFinal(data);
System.out.println("original length: " + original.length + " data: " + bytesToHex(original));
s = new String(original);
//s = new String(original, StandardCharsets.UTF_16LE);
System.out.println(s);
} catch (Exception ex) {
ex.printStackTrace();
}
return s;
}
private static String bytesToHex(byte[] bytes) {
StringBuffer result = new StringBuffer();
for (byte b : bytes) result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
return result.toString();
}
}
英文:
What a shame that you don't show us the encryption code in C# as it would point us directly to the solution instead of arguing and searching.
The reason for your claiming of "truncating" is not on Java-side (decryption) but on your c# encryption function. Most probably you are using a UTF-16 encoding for your plaintext but on Java-side the standard encoding (UTF-8) takes place.
Below you find a slightly added version of your code with dedicated outputs for your data to be fore sure all data has the right length.
Having a look on the ".doFinal" output we see a value of (hex) "650020005200650071007500650073007400200049004400" - a lot of "x00" values between each character that is definitely a UTF-16 encoding, so in the end the string value is not "e Request Id" but "e R e q u e s t I D".
Changing the "new String" encoding to "new String(original, StandardCharsets.UTF_16LE)" get the "correct" output of "e Request ID" - but where is the missing
"Duplicat" in the beginning? I'm sure you are getting the (base64 encoded) string of ciphertext by "Array-copying" as well and you are just copy the last 12 (or 24 in UTF-16) bytes of the ciphertext so - what I am believing - you are truncating the ciphertext on C#-side.
output
First 8 bytes is truncating in AES decryption in java where encryption is done in c#
cipherByte length: 48 data: 87e549e68af6c8115061ac0d597113d759de914cd6618556934fced9f1f1a0b366eb4977777a90a363498c6af7fb364f
ivB length: 16 data: 87e549e68af6c8115061ac0d597113d7
data length: 32 data: 59de914cd6618556934fced9f1f1a0b366eb4977777a90a363498c6af7fb364f
original length: 24 data: 650020005200650071007500650073007400200049004400
e R e q u e s t I D
e R e q u e s t I D
change code line
s = new String(original);
to
s = new String(original, StandardCharsets.UTF_16LE);
gives:
e Request ID
code:
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import java.security.spec.KeySpec;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import java.util.Base64;
public class mainSo {
public static void main(String[] args) {
System.out.println("First 8 bytes is truncating in AES decryption in java where encryption is done in c#");
String cipherstring = "h+VJ5or2yBFQYawNWXET11nekUzWYYVWk0/O2fHxoLNm60l3d3qQo2NJjGr3+zZP";
byte[] cipherByte = Base64.getDecoder().decode(cipherstring);
System.out.println("cipherByte length: " + cipherByte.length + " data: " + bytesToHex(cipherByte));
String cum006333 = decrypt(cipherstring, "KEY@CRISIL123");
System.out.println(cum006333);
}
public static String decrypt(String cipherText, String passphrase) {
String s = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] bytes = Base64.getDecoder().decode(cipherText);
int keySize = 256;
int iterCount = 1000;
int ivLength = 16;
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
byte[] ivB = Arrays.copyOf(bytes, ivLength);
byte[] data = Arrays.copyOfRange(bytes,ivLength, bytes.length);
System.out.println("ivB length: " + ivB.length + " data: " + bytesToHex(ivB));
System.out.println("data length: " + data.length + " data: " + bytesToHex(data));
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, iterCount, keySize);
SecretKey key = new SecretKeySpec(factory.generateSecret(spec).getEncoded(), "AES");
IvParameterSpec iv = new IvParameterSpec(ivB);
cipher.init(Cipher.DECRYPT_MODE, key, iv);
byte[] original = cipher.doFinal(data);
System.out.println("original length: " + original.length + " data: " + bytesToHex(original));
s = new String(original);
//s = new String(original, StandardCharsets.UTF_16LE);
System.out.println(s);
} catch (Exception ex) {
ex.printStackTrace();
}
return s;
}
private static String bytesToHex(byte[] bytes) {
StringBuffer result = new StringBuffer();
for (byte b : bytes) result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
return result.toString();
}
}
答案2
得分: 1
由于您请求只返回翻译的代码部分，以下是您提供的代码的翻译版本：
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.spec.KeySpec;
import java.util.Arrays;
import java.util.Base64;
public class mainSo2 {
public static void main(String[] args) {
System.out.println("在 Java 中，AES 解密时会截断前 8 个字节，而在 C# 中进行加密");
String cipherstring = "h+VJ5or2yBFQYawNWXET11nekUzWYYVWk0/O2fHxoLNm60l3d3qQo2NJjGr3+zZP";
byte[] cipherByte = Base64.getDecoder().decode(cipherstring);
System.out.println("cipherByte 长度：" + cipherByte.length + " 数据：" + bytesToHex(cipherByte));
String decryptedText = decrypt(cipherstring, "KEY@CRISIL123");
System.out.println(decryptedText);
}
public static String decrypt(String cipherText, String passphrase) {
String s = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] bytes = Base64.getDecoder().decode(cipherText);
int keySize = 256;
int iterCount = 1000;
int ivLength = 16;
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, iterCount, (keySize + (8 * ivLength))); // 32 + 16
byte[] rawKey = factory.generateSecret(spec).getEncoded(); // 48 字节
byte[] keyDerived = Arrays.copyOf(rawKey, (keySize / 8)); // 前 32 字节
byte[] ivB = Arrays.copyOfRange(rawKey, (keySize / 8), rawKey.length); // 后 16 字节
System.out.println("keyDerived 长度：" + keyDerived.length + " 数据：" + bytesToHex(keyDerived));
System.out.println("ivB 长度：" + ivB.length + " 数据：" + bytesToHex(ivB));
SecretKey key = new SecretKeySpec(keyDerived, "AES");
IvParameterSpec iv = new IvParameterSpec(ivB);
cipher.init(Cipher.DECRYPT_MODE, key, iv);
byte[] original = cipher.doFinal(bytes);
System.out.println("original 长度：" + original.length + " 数据：" + bytesToHex(original));
s = new String(original, StandardCharsets.UTF_16LE);
System.out.println(s);
} catch (Exception ex) {
ex.printStackTrace();
}
return s;
}
private static String bytesToHex(byte[] bytes) {
StringBuffer result = new StringBuffer();
for (byte b : bytes) result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
return result.toString();
}
}
注意：由于您的代码涉及一些具体的技术内容，本翻译可能无法完全反映原始代码的含义和功能。如果您有任何关于翻译结果的疑问，欢迎随时提问。
英文:
As I don't like to mix answers I'm writing a second answer with the final solution for your question.
Thanks for providing the C#-code as it answered 2 questions - what is the encoding of the plaintext and what data is included in the ciphertext.
Using this line on C# shows us that the encoding is UNICODE (=UTF 16) as I argued in my first answer:
byte[] clearBytes = Encoding.Unicode.GetBytes(clearText);
To get identical results in Java you need to decode any decryption result with
s = new String(original, StandardCharsets.UTF_16LE);
The second question - what is included in the ciphertext is answered very simple - just the ciphertext itself (no IV). The neccessary IV is derived by the
Rfc2898DeriveBytes...
encryptor.Key = rfcdb.GetBytes(32);
encryptor.IV = rfcdb.GetBytes(16);
Putting both information together I can decrypt the ciphertext with the given key as follows:
First 8 bytes is truncating in AES decryption in java where encryption is done in c#
cipherByte length: 48 data: 87e549e68af6c8115061ac0d597113d759de914cd6618556934fced9f1f1a0b366eb4977777a90a363498c6af7fb364f
keyDerived length: 32 data: e35b88684a86fe06ae80eab429b2c9c242ab64f225649aa484ced8f53e5de146
ivB length: 16 data: 19b9e11cb1e6c6aa69060fbdfe10484c
original length: 40 data: 4400750070006c006900630061007400650020005200650071007500650073007400200049004400
Duplicate Request ID
Duplicate Request ID
Here is the complete code:
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.spec.KeySpec;
import java.util.Arrays;
import java.util.Base64;
public class mainSo2 {
public static void main(String[] args) {
System.out.println("First 8 bytes is truncating in AES decryption in java where encryption is done in c#");
String cipherstring = "h+VJ5or2yBFQYawNWXET11nekUzWYYVWk0/O2fHxoLNm60l3d3qQo2NJjGr3+zZP";
byte[] cipherByte = Base64.getDecoder().decode(cipherstring);
System.out.println("cipherByte length: " + cipherByte.length + " data: " + bytesToHex(cipherByte));
String cum006333 = decrypt(cipherstring, "KEY@CRISIL123");
System.out.println(cum006333);
}
public static String decrypt(String cipherText, String passphrase) {
String s = null;
try {
Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] bytes = Base64.getDecoder().decode(cipherText);
int keySize = 256;
int iterCount = 1000;
int ivLength = 16;
byte[] saltByte = new byte[]{0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76};
KeySpec spec = new PBEKeySpec(passphrase.toCharArray(), saltByte, iterCount, (keySize + (8 * ivLength))); // 32 + 16
byte[] rawKey = factory.generateSecret(spec).getEncoded(); // 48 bytes
byte[] keyDerived = Arrays.copyOf(rawKey, (keySize / 8)); // first 32 bytes
byte[] ivB = Arrays.copyOfRange(rawKey, (keySize / 8), rawKey.length); // last 16 bytes
System.out.println("keyDerived length: " + keyDerived.length + " data: " + bytesToHex(keyDerived));
System.out.println("ivB length: " + ivB.length + " data: " + bytesToHex(ivB));
SecretKey key = new SecretKeySpec(keyDerived, "AES");
IvParameterSpec iv = new IvParameterSpec(ivB);
cipher.init(Cipher.DECRYPT_MODE, key, iv);
//byte[] original = cipher.doFinal(data);
byte[] original = cipher.doFinal(bytes);
System.out.println("original length: " + original.length + " data: " + bytesToHex(original));
s = new String(original, StandardCharsets.UTF_16LE);
System.out.println(s);
} catch (Exception ex) {
ex.printStackTrace();
}
return s;
}
private static String bytesToHex(byte[] bytes) {
StringBuffer result = new StringBuffer();
for (byte b : bytes) result.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
return result.toString();
}
}
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