msoffcrypto-tool

The msoffcrypto.format package provides specialized modules for handling different Microsoft Office file formats. Developers can use these submodules to interact with specific encryption structures for legacy and modern Office documents.

Supported format submodules include:

• msoffcrypto.format.doc97: For legacy Word documents.
• msoffcrypto.format.ppt97: For legacy PowerPoint presentations.
• msoffcrypto.format.xls97: For legacy Excel spreadsheets.
• msoffcrypto.format.ooxml: For modern Office Open XML formats (e.g., .docx, .xlsx, .pptx).
• msoffcrypto.format.base: Contains base classes and fundamental logic.
• msoffcrypto.format.common: Contains shared utilities used across different format modules.

The msoffcrypto package is used for handling Microsoft Office encrypted files. It is organized into several subpackages that handle specific aspects of the decryption process:

• msoffcrypto.exceptions: Contains exception classes for error handling.
• msoffcrypto.format: Handles the parsing and structure of different Office file formats.
• msoffcrypto.method: Manages the cryptographic methods used for encryption/decryption.

The main msoffcrypto module serves as the primary entry point for interacting with the tool.

Install the tool and its library components using pip:

pip install msoffcrypto-tool

Note: The encryption feature is experimental. It only supports OOXML formats via the msoffcrypto.format.ooxml.OOXMLFile class.

Basic Encryption:

from msoffcrypto.format.ooxml import OOXMLFile

plain = open("plain.docx", "rb")
file = OOXMLFile(plain)

with open("encrypted.docx", "wb") as f:
    file.encrypt("Passw0rd", f)

plain.close()

In-memory Encryption:

from msoffcrypto.format.ooxml import OOXMLFile
import io

encrypted = io.BytesIO()

with open("plain.xlsx", "rb") as f:
    file = OOXMLFile(f)
    file.encrypt("Passw0rd", encrypted)

# 'encrypted' now contains an OLE container with an encrypted stream

Use the msoffcrypto.OfficeFile class to handle decryption in your Python code. You must first load the key using load_key() before calling decrypt().

Basic Decryption:

import msoffcrypto

encrypted = open("encrypted.docx", "rb")
file = msoffcrypto.OfficeFile(encrypted)
file.load_key(password="Passw0rd")

with open("decrypted.docx", "wb") as f:
    file.decrypt(f)

encrypted.close()

In-memory Decryption (e.g., for Pandas):

import msoffcrypto
import io
import pandas as pd

decrypted = io.BytesIO()

with open("encrypted.xlsx", "rb") as f:
    file = msoffcrypto.OfficeFile(f)
    file.load_key(password="Passw0rd")
    file.decrypt(decrypted)

df = pd.read_excel(decrypted)
print(df)

The following modules are available within the msoffcrypto.method package for handling different encryption standards:

• msoffcrypto.method.ecma376_agile: Implements the ECMA-376 Agile encryption standard.
• msoffcrypto.method.ecma376_extensible: Implements the ECMA-376 Extensible encryption standard.
• msoffcrypto.method.ecma376_standard: Implements the ECMA-376 Standard encryption standard.
• msoffcrypto.method.rc4: Implements the RC4 encryption algorithm.
• msoffcrypto.method.rc4_cryptoapi: Implements RC4 using the Windows CryptoAPI.
• msoffcrypto.method.xor_obfuscation: Implements XOR-based obfuscation.

Note: The encryption feature is currently experimental. Use it at your own risk. It only supports OOXML formats.

To password-protect a document, use the -e flag along with the -p flag.

msoffcrypto-tool -e -p Passw0rd plain.docx encrypted.docx

Use the msoffcrypto-tool command to decrypt files. You can provide the password directly using the -p flag or omit it to be prompted for input.

Decryption Command: msoffcrypto-tool <encrypted_file> <decrypted_file> -p <password>

Check if a file is encrypted: Use the -t flag with --test and -v (verbose) to check encryption status. The command returns exit code 1 if the file is encrypted and 0 if it is not.

# Decrypt with password
msoffcrypto-tool encrypted.docx decrypted.docx -p Passw0rd

# Decrypt with password prompt
msoffcrypto-tool encrypted.docx decrypted.docx -p

# Test if file is encrypted
msoffcrypto-tool document.doc --test -v

The following flags and arguments are available for the msoffcrypto-tool command line interface:

Use the -t or --test flag to check if a file is encrypted. This is a mutually exclusive option with the --password flag. If the file is not encrypted, the tool will print an error to stderr and exit with code 1.

msoffcrypto-tool input.docx --test