GHSA-jp3w-3q88-34cf
Miscomputation when performing AES encryption in rust-crypto
Severidad por fuente
Ninguna fuente da una puntuación CVSS.
La etiqueta propia de Trivy es CRITICAL. Crítica según GHSA.
Descripción
The following Rust program demonstrates some strangeness in AES encryption - if you have an immutable key slice and then operate on that slice, you get different encryption output than if you operate on a copy of that key. For these functions, we expect that extending a 16 byte key to a 32 byte key by repeating it gives the same encrypted data, because the underlying rust-crypto functions repeat key data up to the necessary key size for the cipher. ```rust use crypto::{ aes, blockmodes, buffer, buffer::{BufferResult, ReadBuffer, WriteBuffer}, symmetriccipher, }; fn encrypt( key: &[u8], iv: &[u8], data: &str, ) -> Result<String, symmetriccipher::SymmetricCipherError> { let mut encryptor = aes::cbc_encryptor(aes::KeySize::KeySize256, key, iv, blockmodes::PkcsPadding); let mut encrypted_data = Vec::<u8>::new(); let mut read_buffer = buffer::RefReadBuffer::new(data.as_bytes()); let mut buffer = [0; 4096]; let mut write_buffer = buffer::RefWriteBuffer::new(&mut buffer); loop { let result = encryptor.encrypt(&mut read_buffer, &mut write_buffer, true)?; encrypted_data.extend( write_buffer .take_read_buffer() .take_remaining() .iter() .copied(), ); match result { BufferResult::BufferUnderflow => break, BufferResult::BufferOverflow => {} } } Ok(hex::encode(encrypted_data)) } fn working() { let data = "data"; let iv = [ 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF, ]; let key = [ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, ]; // The copy here makes the code work. let key_copy = key; let key2: Vec<u8> = key_copy.iter().cycle().take(32).copied().collect(); println!("key1:{} key2: {}", hex::encode(&key), hex::encode(&key2)); let x1 = encrypt(&key, &iv, data).unwrap(); println!("X1: {}", x1); let x2 = encrypt(&key2, &iv, data).unwrap(); println!("X2: {}", x2); assert_eq!(x1, x2); } fn broken() { let data = "data"; let iv = [ 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF, ]; let key = [ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, ]; // This operation shouldn't affect the contents of key at all. let key2: Vec<u8> = key.iter().cycle().take(32).copied().collect(); println!("key1:{} key2: {}", hex::encode(&key), hex::encode(&key2)); let x1 = encrypt(&key, &iv, data).unwrap(); println!("X1: {}", x1); let x2 = encrypt(&key2, &iv, data).unwrap(); println!("X2: {}", x2); assert_eq!(x1, x2); } fn main() { working(); broken(); } ``` The output from this program: ```shell Running `target/host/debug/rust-crypto-test` key1:000102030405060708090a0b0c0d0e0f key2: 000102030405060708090a0b0c0d0e0f000102030405060708090a0b0c0d0e0f X1: 90462bbe32965c8e7ea0addbbed4cddb X2: 90462bbe32965c8e7ea0addbbed4cddb key1:000102030405060708090a0b0c0d0e0f key2: 000102030405060708090a0b0c0d0e0f000102030405060708090a0b0c0d0e0f X1: 26e847e5e7df1947bf82a650548a7d5b X2: 90462bbe32965c8e7ea0addbbed4cddb thread 'main' panicked at 'assertion failed: `(left == right)` left: `"26e847e5e7df1947bf82a650548a7d5b"`, right: `"90462bbe32965c8e7ea0addbbed4cddb"`', src/main.rs:83:5 ``` Notably, the X1 key in the `broken()` test changes every time after rerunning the program.
Paquetes afectados y versiones corregidas
| Fuente | Paquete | Corregido en |
|---|---|---|
| cargo::GitHub Security Advisory Rust | rust-crypto | sin corrección indicada |