A tool/lib to encrypt/decrypt Microsoft Office Document

Environment

• 64-bit Windows Visual Studio 2012 or later
• gcc 4.6, clang 3.0 or later
• libssl
  • sudo apt install libssl-dev

How to make bin/msoffice-crypt.exe

Linux / MacOS

    mkdir work
    git clone https://github.com/herumi/cybozulib
    git clone https://github.com/herumi/msoffice
    cd msoffice
    make -j RELEASE=1

Windows

    mkdir work
    git clone https://github.com/herumi/cybozulib
    git clone https://github.com/herumi/msoffice
    git clone https://github.com/herumi/cybozulib_ext # for openssl
    cd msoffice
    mk.bat ; or open msoffice12.sln and build

How to use

• Encrypt test.xlsx with a password test.

bin/msoffice-crypt.exe -e -p test test.xlsx enc.xlsx

• Decrypt enc.xlsx with a password test.

bin/msoffice-crypt.exe -d -p test enc.xlsx dec.xlsx

Support format

Office 2010 or later Office Document format which suffix is pptx, docx, xlsx.

DLL for Windows

• msoc.dll (Microsoft Office Crypto)

• msoc.dll

• msoc.h

• Encrypt inFile with pass and make outFile.

MSOC_encrypt(outFile, inFile, pass, NULL);

• Decrypt inFile with pass and make outFile.

MSOC_decrypt(outFile, inFile, pass, NULL);

lib for Linux

• libmsoc.lib

License

BSD 3-Clause License

Copyright (c) 2015 Cybozu Labs, Inc. All rights reserved.

References

• Compound File Binary File Format(v20120328) [MS-CFB]

• Office Document Cryptography Structure Specification(v20120412) [MS-OFFCRYPTO]

• CODE BLUE 2015 [Backdoors with the MS Office file encryption master key and a proposal for a reliable file format]

• 99.9% built by herumi <3