From 218caa410aa38c29984be31a5229b9fa717560ee Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:13 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- vendor/zip/src/aes_ctr.rs | 281 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 281 insertions(+) create mode 100644 vendor/zip/src/aes_ctr.rs (limited to 'vendor/zip/src/aes_ctr.rs') diff --git a/vendor/zip/src/aes_ctr.rs b/vendor/zip/src/aes_ctr.rs new file mode 100644 index 000000000..0f34335cb --- /dev/null +++ b/vendor/zip/src/aes_ctr.rs @@ -0,0 +1,281 @@ +//! A counter mode (CTR) for AES to work with the encryption used in zip files. +//! +//! This was implemented since the zip specification requires the mode to not use a nonce and uses a +//! different byte order (little endian) than NIST (big endian). +//! See [AesCtrZipKeyStream](./struct.AesCtrZipKeyStream.html) for more information. + +use aes::cipher::generic_array::GenericArray; +use aes::{BlockEncrypt, NewBlockCipher}; +use byteorder::WriteBytesExt; +use std::{any, fmt}; + +/// Internal block size of an AES cipher. +const AES_BLOCK_SIZE: usize = 16; + +/// AES-128. +#[derive(Debug)] +pub struct Aes128; +/// AES-192 +#[derive(Debug)] +pub struct Aes192; +/// AES-256. +#[derive(Debug)] +pub struct Aes256; + +/// An AES cipher kind. +pub trait AesKind { + /// Key type. + type Key: AsRef<[u8]>; + /// Cipher used to decrypt. + type Cipher; +} + +impl AesKind for Aes128 { + type Key = [u8; 16]; + type Cipher = aes::Aes128; +} + +impl AesKind for Aes192 { + type Key = [u8; 24]; + type Cipher = aes::Aes192; +} + +impl AesKind for Aes256 { + type Key = [u8; 32]; + type Cipher = aes::Aes256; +} + +/// An AES-CTR key stream generator. +/// +/// Implements the slightly non-standard AES-CTR variant used by WinZip AES encryption. +/// +/// Typical AES-CTR implementations combine a nonce with a 64 bit counter. WinZIP AES instead uses +/// no nonce and also uses a different byte order (little endian) than NIST (big endian). +/// +/// The stream implements the `Read` trait; encryption or decryption is performed by XOR-ing the +/// bytes from the key stream with the ciphertext/plaintext. +pub struct AesCtrZipKeyStream { + /// Current AES counter. + counter: u128, + /// AES cipher instance. + cipher: C::Cipher, + /// Stores the currently available keystream bytes. + buffer: [u8; AES_BLOCK_SIZE], + /// Number of bytes already used up from `buffer`. + pos: usize, +} + +impl fmt::Debug for AesCtrZipKeyStream +where + C: AesKind, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!( + f, + "AesCtrZipKeyStream<{}>(counter: {})", + any::type_name::(), + self.counter + ) + } +} + +impl AesCtrZipKeyStream +where + C: AesKind, + C::Cipher: NewBlockCipher, +{ + /// Creates a new zip variant AES-CTR key stream. + /// + /// # Panics + /// + /// This panics if `key` doesn't have the correct size for cipher `C`. + pub fn new(key: &[u8]) -> AesCtrZipKeyStream { + AesCtrZipKeyStream { + counter: 1, + cipher: C::Cipher::new(GenericArray::from_slice(key)), + buffer: [0u8; AES_BLOCK_SIZE], + pos: AES_BLOCK_SIZE, + } + } +} + +impl AesCipher for AesCtrZipKeyStream +where + C: AesKind, + C::Cipher: BlockEncrypt, +{ + /// Decrypt or encrypt `target`. + #[inline] + fn crypt_in_place(&mut self, mut target: &mut [u8]) { + while !target.is_empty() { + if self.pos == AES_BLOCK_SIZE { + // Note: AES block size is always 16 bytes, same as u128. + self.buffer + .as_mut() + .write_u128::(self.counter) + .expect("did not expect u128 le conversion to fail"); + self.cipher + .encrypt_block(GenericArray::from_mut_slice(&mut self.buffer)); + self.counter += 1; + self.pos = 0; + } + + let target_len = target.len().min(AES_BLOCK_SIZE - self.pos); + + xor( + &mut target[0..target_len], + &self.buffer[self.pos..(self.pos + target_len)], + ); + target = &mut target[target_len..]; + self.pos += target_len; + } + } +} + +/// This trait allows using generic AES ciphers with different key sizes. +pub trait AesCipher { + fn crypt_in_place(&mut self, target: &mut [u8]); +} + +/// XORs a slice in place with another slice. +#[inline] +fn xor(dest: &mut [u8], src: &[u8]) { + assert_eq!(dest.len(), src.len()); + + for (lhs, rhs) in dest.iter_mut().zip(src.iter()) { + *lhs ^= *rhs; + } +} + +#[cfg(test)] +mod tests { + use super::{Aes128, Aes192, Aes256, AesCipher, AesCtrZipKeyStream, AesKind}; + use aes::{BlockEncrypt, NewBlockCipher}; + + /// Checks whether `crypt_in_place` produces the correct plaintext after one use and yields the + /// cipertext again after applying it again. + fn roundtrip(key: &[u8], ciphertext: &mut [u8], expected_plaintext: &[u8]) + where + Aes: AesKind, + Aes::Cipher: NewBlockCipher + BlockEncrypt, + { + let mut key_stream = AesCtrZipKeyStream::::new(key); + + let mut plaintext: Vec = ciphertext.to_vec(); + key_stream.crypt_in_place(plaintext.as_mut_slice()); + assert_eq!(plaintext, expected_plaintext.to_vec()); + + // Round-tripping should yield the ciphertext again. + let mut key_stream = AesCtrZipKeyStream::::new(key); + key_stream.crypt_in_place(&mut plaintext); + assert_eq!(plaintext, ciphertext.to_vec()); + } + + #[test] + #[should_panic] + fn new_with_wrong_key_size() { + AesCtrZipKeyStream::::new(&[1, 2, 3, 4, 5]); + } + + // The data used in these tests was generated with p7zip without any compression. + // It's not possible to recreate the exact same data, since a random salt is used for encryption. + // `7z a -phelloworld -mem=AES256 -mx=0 aes256_40byte.zip 40byte_data.txt` + #[test] + fn crypt_aes_256_0_byte() { + let mut ciphertext = []; + let expected_plaintext = &[]; + let key = [ + 0x0b, 0xec, 0x2e, 0xf2, 0x46, 0xf0, 0x7e, 0x35, 0x16, 0x54, 0xe0, 0x98, 0x10, 0xb3, + 0x18, 0x55, 0x24, 0xa3, 0x9e, 0x0e, 0x40, 0xe7, 0x92, 0xad, 0xb2, 0x8a, 0x48, 0xf4, + 0x5c, 0xd0, 0xc0, 0x54, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } + + #[test] + fn crypt_aes_128_5_byte() { + let mut ciphertext = [0x98, 0xa9, 0x8c, 0x26, 0x0e]; + let expected_plaintext = b"asdf\n"; + let key = [ + 0xe0, 0x25, 0x7b, 0x57, 0x97, 0x6a, 0xa4, 0x23, 0xab, 0x94, 0xaa, 0x44, 0xfd, 0x47, + 0x4f, 0xa5, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } + + #[test] + fn crypt_aes_192_5_byte() { + let mut ciphertext = [0x36, 0x55, 0x5c, 0x61, 0x3c]; + let expected_plaintext = b"asdf\n"; + let key = [ + 0xe4, 0x4a, 0x88, 0x52, 0x8f, 0xf7, 0x0b, 0x81, 0x7b, 0x75, 0xf1, 0x74, 0x21, 0x37, + 0x8c, 0x90, 0xad, 0xbe, 0x4a, 0x65, 0xa8, 0x96, 0x0e, 0xcc, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } + + #[test] + fn crypt_aes_256_5_byte() { + let mut ciphertext = [0xc2, 0x47, 0xc0, 0xdc, 0x56]; + let expected_plaintext = b"asdf\n"; + let key = [ + 0x79, 0x5e, 0x17, 0xf2, 0xc6, 0x3d, 0x28, 0x9b, 0x4b, 0x4b, 0xbb, 0xa9, 0xba, 0xc9, + 0xa5, 0xee, 0x3a, 0x4f, 0x0f, 0x4b, 0x29, 0xbd, 0xe9, 0xb8, 0x41, 0x9c, 0x41, 0xa5, + 0x15, 0xb2, 0x86, 0xab, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } + + #[test] + fn crypt_aes_128_40_byte() { + let mut ciphertext = [ + 0xcf, 0x72, 0x6b, 0xa1, 0xb2, 0x0f, 0xdf, 0xaa, 0x10, 0xad, 0x9c, 0x7f, 0x6d, 0x1c, + 0x8d, 0xb5, 0x16, 0x7e, 0xbb, 0x11, 0x69, 0x52, 0x8c, 0x89, 0x80, 0x32, 0xaa, 0x76, + 0xa6, 0x18, 0x31, 0x98, 0xee, 0xdd, 0x22, 0x68, 0xb7, 0xe6, 0x77, 0xd2, + ]; + let expected_plaintext = b"Lorem ipsum dolor sit amet, consectetur\n"; + let key = [ + 0x43, 0x2b, 0x6d, 0xbe, 0x05, 0x76, 0x6c, 0x9e, 0xde, 0xca, 0x3b, 0xf8, 0xaf, 0x5d, + 0x81, 0xb6, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } + + #[test] + fn crypt_aes_192_40_byte() { + let mut ciphertext = [ + 0xa6, 0xfc, 0x52, 0x79, 0x2c, 0x6c, 0xfe, 0x68, 0xb1, 0xa8, 0xb3, 0x07, 0x52, 0x8b, + 0x82, 0xa6, 0x87, 0x9c, 0x72, 0x42, 0x3a, 0xf8, 0xc6, 0xa9, 0xc9, 0xfb, 0x61, 0x19, + 0x37, 0xb9, 0x56, 0x62, 0xf4, 0xfc, 0x5e, 0x7a, 0xdd, 0x55, 0x0a, 0x48, + ]; + let expected_plaintext = b"Lorem ipsum dolor sit amet, consectetur\n"; + let key = [ + 0xac, 0x92, 0x41, 0xba, 0xde, 0xd9, 0x02, 0xfe, 0x40, 0x92, 0x20, 0xf6, 0x56, 0x03, + 0xfe, 0xae, 0x1b, 0xba, 0x01, 0x97, 0x97, 0x79, 0xbb, 0xa6, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } + + #[test] + fn crypt_aes_256_40_byte() { + let mut ciphertext = [ + 0xa9, 0x99, 0xbd, 0xea, 0x82, 0x9b, 0x8f, 0x2f, 0xb7, 0x52, 0x2f, 0x6b, 0xd8, 0xf6, + 0xab, 0x0e, 0x24, 0x51, 0x9e, 0x18, 0x0f, 0xc0, 0x8f, 0x54, 0x15, 0x80, 0xae, 0xbc, + 0xa0, 0x5c, 0x8a, 0x11, 0x8d, 0x14, 0x7e, 0xc5, 0xb4, 0xae, 0xd3, 0x37, + ]; + let expected_plaintext = b"Lorem ipsum dolor sit amet, consectetur\n"; + let key = [ + 0x64, 0x7c, 0x7a, 0xde, 0xf0, 0xf2, 0x61, 0x49, 0x1c, 0xf1, 0xf1, 0xe3, 0x37, 0xfc, + 0xe1, 0x4d, 0x4a, 0x77, 0xd4, 0xeb, 0x9e, 0x3d, 0x75, 0xce, 0x9a, 0x3e, 0x10, 0x50, + 0xc2, 0x07, 0x36, 0xb6, + ]; + + roundtrip::(&key, &mut ciphertext, expected_plaintext); + } +} -- cgit v1.2.3