1 unstable release
0.1.0 | Jan 18, 2023 |
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#4 in #powerpoint
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51KB
995 lines
office-crypto
Pure Rust library to decrypt password-protected MS Office files.
Example
This crate exposes two functions: decrypt_from_file
and decrypt_from_bytes
, which do exactly what they say they do. The resulting bytes can then be interpreted by any MS Office parser like docx or calamine.
use docx::DocxFile;
use office_crypto::decrypt_from_file;
use std::io::Cursor;
let decrypted: Vec<u8> = decrypt_from_file("protected.docx", "Password1234_").unwrap();
let docx = DocxFile::from_reader(Cursor::new(decrypted)).unwrap();
let docx = docx.parse().unwrap();
// Now we can access the docx content
Formats
- ECMA-376 (Agile Encryption/Standard Encryption)
- MS-DOCX (OOXML) (Word 2007-Present)
- MS-XLSX (OOXML) (Excel 2007-Present)
- MS-PPTX (OOXML) (PowerPoint 2007-Present)
- Office Binary Document RC4 CryptoAPI
- MS-DOC (Word 2002, 2003, 2004)
- MS-XLS (Excel 2002, 2003, 2004)
- MS-PPT (PowerPoint 2002, 2003, 2004)
- ECMA-376 (Extensible Encryption)
Non-SHA512 hash functions are not yet implemented. This only affects Agile encrypted files, but I have yet to find one that doesn't use SHA512.
Performance
Measured on an M1 Pro:
running 3 tests
test bench_agile_sha512 ... bench: 27,106,487 ns/iter (+/- 505,175)
test bench_agile_sha512_large ... bench: 71,372,716 ns/iter (+/- 3,915,458)
test bench_standard ... bench: 6,379,766 ns/iter (+/- 100,688)
File sizes for tests:
bench_agile_sha512
=> 25 KBbench_agile_sha512_large
=> 7.1 MBbench_standard
=> 7 KB
Note that the latest version of Word will create an Agile encrypted document.
Acknowledgements
This crate is essentially a port of the OOXML-specific features from msoffcrypto and olefile.
Dependencies
~4MB
~86K SLoC