Registration Key Algorithm

This document describes the registration key generation algorithm found in app/src/main/java/bH/C0997e.java.

Overview

The algorithm generates registration keys for product licensing using a multi-step process that combines user information, applies various transformations, and generates a cryptographic hash.

Algorithm Steps

Method 1: Basic Obfuscation

a(String str, String str2, String str3, String str4)

Parameters:

• str - First name
• str2 - Last name
• str3 - Product name
• str4 - Email address

Process:

1. Input Validation - Check all parameters are non-null and non-empty

2. Concatenation - Create byte array by concatenating:

   lastName + productName + firstName + lastName + email
   

3. Byte Reversal - Reverse the entire byte array

   for (int i = 0; i < bArr.length / 2; i++) {
       byte temp = bArr[i];
       bArr[i] = bArr[(bArr.length - 1) - i];
       bArr[(bArr.length - 1) - i] = temp;
   }
   

4. Character Transformation - Apply mathematical formula to each byte:

   for (int i = 0; i < bArr.length; i++) {
       byte b = bArr[i];
       int transformed = (b + ((b - 32) % 7)) - (i % 4);
       if (transformed > 122) {
           transformed -= 9;
       }
       bArr[i] = (byte) transformed;
   }
   

5. Special Character Handling - Modify specific ASCII codes:

   for (int i = 0; i < bArr.length; i++) {
       if (bArr[i] == 96 || bArr[i] == 92 || bArr[i] == 91 || 
           bArr[i] == 93 || bArr[i] == 59 || bArr[i] == 46) {
           bArr[i] = (byte) (bArr[i] + 6 + (i % 10));
       }
   }
   

   Special characters affected: ` (96), \ (92), [ (91), ] (93), ; (59), . (46)

6. Return - Convert byte array to string

Method 2: Registration Key Generation (5 Parameters)

a(String str, String str2, String str3, String str4, String str5)

Parameters:

• str - First name
• str2 - Last name
• str3 - Product name
• str4 - Secret/seed value
• str5 - Email address

Process:

1. Get Obfuscated String - Call Method 1 to get obfuscated base string

2. MD5 Hashing - Create MD5 hash:

   MessageDigest md5 = MessageDigest.getInstance("MD5");
   byte[] input = (obfuscatedString + secret).getBytes();
   md5.update(input);
   md5.update(input);  // Update twice
   md5.digest();       // Digest once (discarded)
   md5.update(input);  // Update again
   byte[] hash = md5.digest();  // Final digest
   

3. Checksum Generation - Create 4-byte checksum using custom algorithm

4. Combine Checksum and Hash:

   result = checksum (4 bytes) + hash (16 bytes) = 20 bytes total
   

5. Base-32 Encoding - Convert to custom base-32 string:

   Charset: "123456789ABCDEFGHIJKLMNPQRSTUVWXYZ" (33 characters, no 'O')
   

   Each byte is mapped to a character: char = charset[abs(byte) % 33]

Method 3: Enhanced Registration Key (7 Parameters)

a(String str, String str2, String str3, String str4, String str5, String str6, String str7)

Additional parameters:

• str6 - Additional field 1
• str7 - Additional field 2

Changes from Method 2:

1. Lowercase Conversion - firstName, lastName, and email are converted to lowercase

2. Extended Base String:

   obfuscated(firstName.toLowerCase(), lastName.toLowerCase(), product, email.toLowerCase()) + field1 + field2
   

3. Modified MD5 Process:

   md5.update(input);
   md5.update(input);
   md5.update((input + field1).getBytes());  // Additional update with field1
   byte[] hash = md5.digest();
   

4. Different Character Set:

   Charset: "23456789ABCDEFGHJKLMNPQRSTUVWXYZ" (31 characters, no '1', 'I', 'O')
   char = charset[abs(byte) % 31]
   

Method 4: Full Registration Key (8 Parameters)

a(String str, String str2, String str3, String str4, String str5, String str6, String str7, String str8)

Additional parameter:

• str8 - Additional field 3

Changes:

• Base string includes all three additional fields: field1 + field2 + field3
• Same character set as Method 3

Usage Context

The registration dialog calls these methods (found in app/src/main/java/ao/dQ.java):

String calculatedKey = C0997e.a(firstName, lastName, "MegaLogViewer", email);

if (calculatedKey != null && calculatedKey.equals(userEnteredKey) && !alreadyRegistered(userEnteredKey)) {
    // Registration successful
}

Key Properties

• Character Sets: Custom base-32 encoding (excludes ambiguous characters like 'O', '1', 'I')
• Output Length: 20 characters (from 20 bytes)
• Hash Algorithm: MD5
• Deterministic: Same inputs always produce same key
• Case Handling: Methods 3 & 4 normalize to lowercase for consistency

Security Notes

• Uses MD5 hashing (considered weak by modern standards)
• Obfuscation through byte manipulation
• No salt/random component (deterministic output)
• Multiple hash iterations for additional complexity
• Custom encoding prevents simple reverse engineering