对E-Safenet加密的密码分析攻击.zip

E-Safenet ========= This GitHub repository contains files that assist in cryptanalytic attacks on E-Safenet encryption. Several attacks were developed that may partially or fully recover E-Safenet encryption keys. * Known-plaintext attack * Probable-plaintext attack * Against source code files * Against binary files * Ciphertext-only attack All specifics and attacks are document in the [research paper](report.pdf?raw=true) on E-Safenet encryption. ## Python scripts The python scripts provided can be used to encrypt and decrypt using the E-Safenet encryption, or to extract encryption keys. Two main files are available: * [**esafenet.py**](esafenet.py): command-line interface to _known-plaintext_ and _probable-plaintext_ attacks * [**esafenet_gui.py**](esafenet_gui.py): GUI interface for the _ciphertext-only_ attack ##### Setup Prior to using these scripts, the simplelzo1x module has to be compiled first. This module provides an interface to the LZO v1.00 compression library. ``` cd simplelzo1x && sudo python setup.py install ``` More information about the library can be found in the [README](simplelzo1x/README) file in the simplelzo1x directory. ### esafenet.py ```none usage: esafenet.py [-h] [--infile INFILE] [--key KEY] [--outfile OUTFILE] [--infolder INFOLDER] [--outfolder OUTFOLDER] [--comp_file COMP_FILE] [--type pattern_type] [--language text_pattern_language] action E-safenet encryption/decryption/key generation positional arguments: action Action to perform Should be one of ['encrypt', 'decrypt', 'encrypt_folder', 'decrypt_folder', 'keygen', 'findkey', 'pattern_decrypt'] optional arguments: -h, --help show this help message and exit --infile INFILE Input file --key KEY Key file --outfile OUTFILE Output file --infolder INFOLDER Input folder --outfolder OUTFOLDER Output folder --comp_file COMP_FILE Plaintext comparison file used by findkey --type pattern_type Type for pattern decrypt (binary or text) --language text_pattern_language Language for text pattern decrypt (C, PHP or CS) ``` ##### Examples * Recovering the encryption key of a binary file (probable-plaintext attack): ``` $ python esafenet.py pattern_decrypt --type binary --infile encrypted.xls --outfile key.dat Decryption: key written to key.dat (4 0-bytes) ``` * Decrypting an E-Safenet file using a provided key: ``` $ python esafenet.py decrypt --infile encrypted.xls --key key.dat --outfile decrypted.xls Decryption: 153400 bytes written to decrypted.xls ``` * Recovering the key using the known-plaintext attack: ``` $ python esafenet.py findkey --infile encrypted.xls --comp_file decrypted.xls --outfile key.dat Succes: key written to key.dat ``` * Recovering the encryption key of source code files (probable-plaintext attack, C#): ``` $ python esafenet.py pattern_decrypt --type text --infolder srcfiles --outfolder /tmp --language CS --outfile key.dat Match found!! ... ``` ##### Troubleshooting If you get errors/crashes, they are probably caused by the LZO compression library. The first 512 bytes of an E-Safenet encrypted file are compressed. When using a wrong key, decompression may fail and lead to a crash. You can temporarily disable decompression of the first block by changing the *plain_header* variable in esafenet.py to an empty string: ``` plain_header = "" # plain_header = simplelzo1x.decompress(decr_header) ``` ### esafenet_gui.py The GUI app **esafenet_gui.py** can be used for the ciphertext-only attack. More information about this attack can be found in the research paper. 1. menu -> Open folder or file, select an E-Safenet file, or a folder containing only E-Safenet files **encrypted with the same key**. 2. menu -> Analyze, analyzes the files, tries to maximize plaintext in the file(s), as described in the report. Note: The analyze step may take some time (15s for 200kB on my 5y/o laptop, displaying results in thhe grid takes even longer...) Results are displayed as-is, this program is not complete. Feel free to do with it as you see fit.  ## CPLEX model For the mathematical implementation of the ciphertext-only attack, [cplex_coa.mod](cplex_coa.mod) provides a CPLEX model for the Binary Integer Programming problem that represents the maximization of printable characters in an E-Safenet encrypted document. ## Credits The code was released under the GPLv2 license.