Analyzed and Diagnosed Compression in .rxdb Files

📅 2025-05-15 — Session: Analyzed and Diagnosed Compression in .rxdb Files

🕒 00:05–00:30
🏷️ Labels: Compression, Data Extraction, Rxdb, LZ4, Diagnosis
📂 Project: Dev
⭐ Priority: MEDIUM

Session Goal: The session aimed to explore and diagnose compression issues in .rxdb files, focusing on extracting embedded dictionaries and analyzing file structures.

Key Activities:

• Explored methods to test hypotheses and extract embedded dictionaries from .rxdb files using shell commands and Python scripts.
• Analyzed the structure of .rxdb files to determine if they were compressed or encrypted, using entropy and statistical tests.
• Diagnosed specific blocks within binary files to identify the validity of compression formats like zlib and gzip.
• Utilized tools such as binwalk and custom scripts to extract compressed blocks and diagnose potential compression issues.
• Identified LZ4 magic signatures and proposed steps to extract and decompress data blocks.

Achievements:

• Confirmed the presence of compression or encryption in .rxdb files.
• Suggested strategies for decompression and further analysis, including the use of specific tools and scripts.
• Identified potential causes for LZ4 decoding errors and provided troubleshooting steps.

Pending Tasks:

• Further investigation into the decompression of specific blocks using alternative methods.
• Development of a C++ script to read strings from specific offsets if required.
• Verification of compression formats and additional testing on LZ4 frame decoding.