How to implement DES encrypting with ('DES/CBC/PKCS5Padding' mode) in Ruby? - ruby

Question

I'v received on some DES encrypted stuff from a 3rd part company. I can't decrypt it in ruby. But it works in my java code.
Here is java code:
public class Main {
public static void main(String[] args) {
try {
System.out.println(encrypt("12345678", "abc", "12345678"));
//System.out.println(encrypt("12345678", "ABC", "12345678"));
System.out.println(decrypt("12345678", "9YR6ZPdZufM=", "12345678"));
//System.out.println(decrypt("12345678", "6rtTnrF34mPkJ5SO3RiaaQ==", "12345678"));
} catch (Exception e) {
e.printStackTrace();
}
}
public static String encrypt(String key, String str, String ivString) throws Exception {
DESKeySpec desKeySpec = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
Key secretKey = keyFactory.generateSecret(desKeySpec);
IvParameterSpec iv = new IvParameterSpec(ivString.getBytes());
cipher.init(Cipher.ENCRYPT_MODE, secretKey, iv);
byte[] bytes = cipher.doFinal(str.getBytes());
dumpHex(bytes);
return Base64.encode(bytes);
}
public static void dumpHex(byte[] bytes) {
for (byte b : bytes) {
System.out.println(String.format("%02x",b&0xff));
}
System.out.println(bytesToHex(bytes));
}
final protected static char[] hexArray = "0123456789ABCDEF".toCharArray();
public static String bytesToHex(byte[] bytes) {
char[] hexChars = new char[bytes.length * 2];
for ( int j = 0; j < bytes.length; j++ ) {
int v = bytes[j] & 0xFF;
hexChars[j * 2] = hexArray[v >>> 4];
hexChars[j * 2 + 1] = hexArray[v & 0x0F];
}
return new String(hexChars);
}
public static String decrypt(String key, String str, String ivString) throws Exception {
byte[] data = Base64.decode(str);
dumpHex(data);
DESKeySpec dks = new DESKeySpec(key.getBytes());
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
Key secretKey = keyFactory.generateSecret(dks);
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
IvParameterSpec iv = new IvParameterSpec(ivString.getBytes());
cipher.init(Cipher.DECRYPT_MODE, secretKey, iv);
byte[] decryptedBytes = cipher.doFinal(data);
return new String(decryptedBytes, "gb2312");
}
}
I couldn't found the same DES mode ('DES/CBC/PKCS5Padding') in ruby. I got the different result when I try to encrypt the same string.
Here is my ruby source code:
class Des
require 'openssl'
require 'base64'
ALG = 'DES-EDE3-CBC'
KEY = "12345678"
DES_KEY = "12345678"
def encode(str)
des = OpenSSL::Cipher::Cipher.new(ALG)
des.pkcs5_keyivgen(KEY, DES_KEY)
des.encrypt
cipher = des.update(str) + des.final
pp cipher.length
pp cipher.unpack('H*')[0]
return Base64.encode64(cipher)
end
def decode(str)
str = Base64.decode64(str)
pp str.unpack('H*')[0]
des = OpenSSL::Cipher::Cipher.new(ALG)
des.pkcs5_keyivgen(KEY, DES_KEY)
des.decrypt
des.update(str) + des.final
end
def KEY()
pp KEY.length
KEY
end
def DES_KEY()
pp DES_KEY.length
DES_KEY
end
end
I encrypt 'abc' with java, get "9YR6ZPdZufM=". But get "5SHCjTOrygg=" in ruby version.It confused me a lot.

Answer 1

I change some config in ruby code, and it works. But I didn't know why...
def DES
ALG = 'DES-EDE-CBC'
KEY = "1234567812345678"
DES_KEY = "12345678"