RUSTSEC-2021-0121

Non-aligned u32 read in Chacha20 encryption and decryption

Reported: October 8, 2021
Issued: October 18, 2021
Package: crypto2 (crates.io)
Type: INFO Unsound
Keywords: #crypto #alignment #unsound
Details: https://github.com/shadowsocks/crypto2/issues/27
Patched: no patched versions

Affected Functions

Version

crypto2::streamcipher::Chacha20::decrypt_slice

crypto2::streamcipher::Chacha20::encrypt_slice

crypto2::streamcipher::xor_si512_inplace

Description

The implementation does not enforce alignment requirements on input slices while incorrectly assuming 4-byte alignment through an unsafe call to std::slice::from_raw_parts_mut, which breaks the contract and introduces undefined behavior.

This affects Chacha20 encryption and decryption in crypto2.