msoffcrypto-tool is a Python tool and library for decrypting and encrypting MS Office files using a password or other keys.
Contents
Installation
pip install msoffcrypto-tool
Examples
Decryption
Specify the password with -p flag:
msoffcrypto-tool encrypted.docx decrypted.docx -p Passw0rd
Password is prompted if you omit the password argument value:
$ msoffcrypto-tool encrypted.docx decrypted.docx -p
Password:
To check if the file is encrypted or not, use -t flag:
msoffcrypto-tool document.doc --test -v
It returns 1 if the file is encrypted, 0 if not.
Encryption (OOXML only, experimental)
Encryption feature is experimental. Please use it at your own risk.
To password-protect a document, use -e flag along with -p flag:
msoffcrypto-tool -e -p Passw0rd plain.docx encrypted.docx
As library
Password and more key types are supported with library functions.
Decryption
Basic usage:
import msoffcrypto
encrypted = open("encrypted.docx", "rb")
file = msoffcrypto.OfficeFile(encrypted)
file.load_key(password="Passw0rd") # Use password
with open("decrypted.docx", "wb") as f:
file.decrypt(f)
encrypted.close()
In-memory:
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") # Use password
file.decrypt(decrypted)
df = pd.read_excel(decrypted)
print(df)
Advanced usage:
# Verify password before decryption (default: False)
# The ECMA-376 Agile/Standard crypto system allows one to know whether the supplied password is correct before actually decrypting the file
# Currently, the verify_password option is only meaningful for ECMA-376 Agile/Standard Encryption
file.load_key(password="Passw0rd", verify_password=True)
# Use private key
file.load_key(private_key=open("priv.pem", "rb"))
# Use intermediate key (secretKey)
file.load_key(secret_key=binascii.unhexlify("AE8C36E68B4BB9EA46E5544A5FDB6693875B2FDE1507CBC65C8BCF99E25C2562"))
# Check the HMAC of the data payload before decryption (default: False)
# Currently, the verify_integrity option is only meaningful for ECMA-376 Agile Encryption
file.decrypt(open("decrypted.docx", "wb"), verify_integrity=True)
Supported key types are
- Passwords
- Intermediate keys (optional)
- Private keys used for generating escrow keys (escrow certificates) (optional)
See also “Backdooring MS Office documents with secret master keys” for more information on the key types.
Encryption (OOXML only, experimental)
Encryption feature is experimental. Please use it at your own risk.
Basic usage:
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:
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)
# Do stuff with encrypted buffer; it contains an OLE container with an encrypted stream
...
Supported encryption methods
MS-OFFCRYPTO specs
Other
PRs are welcome!
Tests
With coverage and pytest:
poetry install
poetry run coverage run -m pytest -v
Todo
Resources
Alternatives
Use cases and mentions
General
Corporate
Malware/maldoc analysis
CTF
In other languages
In publications
Contributors
Credits
评论