use std::iter::repeat;
use libc::{c_int};
use ffi;
#[derive(Copy)]
pub enum Mode {
Encrypt,
Decrypt,
}
#[allow(non_camel_case_types)]
#[derive(Copy)]
pub enum Type {
AES_128_ECB,
AES_128_CBC,
#[cfg(feature = "aes_xts")]
AES_128_XTS,
AES_256_ECB,
AES_256_CBC,
#[cfg(feature = "aes_xts")]
AES_256_XTS,
RC4_128,
}
fn evpc(t: Type) -> (*const ffi::EVP_CIPHER, u32, u32) {
unsafe {
match t {
Type::AES_128_ECB => (ffi::EVP_aes_128_ecb(), 16, 16),
Type::AES_128_CBC => (ffi::EVP_aes_128_cbc(), 16, 16),
#[cfg(feature = "aes_xts")]
Type::AES_128_XTS => (ffi::EVP_aes_128_xts(), 32, 16),
Type::AES_256_ECB => (ffi::EVP_aes_256_ecb(), 32, 16),
Type::AES_256_CBC => (ffi::EVP_aes_256_cbc(), 32, 16),
#[cfg(feature = "aes_xts")]
Type::AES_256_XTS => (ffi::EVP_aes_256_xts(), 64, 16),
Type::RC4_128 => (ffi::EVP_rc4(), 16, 0),
}
}
}
pub struct Crypter {
evp: *const ffi::EVP_CIPHER,
ctx: *mut ffi::EVP_CIPHER_CTX,
keylen: u32,
blocksize: u32,
}
impl Crypter {
pub fn new(t: Type) -> Crypter {
ffi::init();
let ctx = unsafe { ffi::EVP_CIPHER_CTX_new() };
let (evp, keylen, blocksz) = evpc(t);
Crypter { evp: evp, ctx: ctx, keylen: keylen, blocksize: blocksz }
}
pub fn pad(&self, padding: bool) {
if self.blocksize > 0 {
unsafe {
let v = if padding { 1 as c_int } else { 0 };
ffi::EVP_CIPHER_CTX_set_padding(self.ctx, v);
}
}
}
pub fn init(&self, mode: Mode, key: &[u8], iv: Vec<u8>) {
unsafe {
let mode = match mode {
Mode::Encrypt => 1 as c_int,
Mode::Decrypt => 0 as c_int,
};
assert_eq!(key.len(), self.keylen as usize);
ffi::EVP_CipherInit(
self.ctx,
self.evp,
key.as_ptr(),
iv.as_ptr(),
mode
);
}
}
pub fn update(&self, data: &[u8]) -> Vec<u8> {
unsafe {
let sum = data.len() + (self.blocksize as usize);
let mut res = repeat(0u8).take(sum).collect::<Vec<_>>();
let mut reslen = sum as c_int;
ffi::EVP_CipherUpdate(
self.ctx,
res.as_mut_ptr(),
&mut reslen,
data.as_ptr(),
data.len() as c_int
);
res.truncate(reslen as usize);
res
}
}
pub fn finalize(&self) -> Vec<u8> {
unsafe {
let mut res = repeat(0u8).take(self.blocksize as usize).collect::<Vec<_>>();
let mut reslen = self.blocksize as c_int;
ffi::EVP_CipherFinal(self.ctx,
res.as_mut_ptr(),
&mut reslen);
res.truncate(reslen as usize);
res
}
}
}
impl Drop for Crypter {
fn drop(&mut self) {
unsafe {
ffi::EVP_CIPHER_CTX_free(self.ctx);
}
}
}
pub fn encrypt(t: Type, key: &[u8], iv: Vec<u8>, data: &[u8]) -> Vec<u8> {
let c = Crypter::new(t);
c.init(Mode::Encrypt, key, iv);
let mut r = c.update(data);
let rest = c.finalize();
r.extend(rest.into_iter());
r
}
pub fn decrypt(t: Type, key: &[u8], iv: Vec<u8>, data: &[u8]) -> Vec<u8> {
let c = Crypter::new(t);
c.init(Mode::Decrypt, key, iv);
let mut r = c.update(data);
let rest = c.finalize();
r.extend(rest.into_iter());
r
}
#[cfg(test)]
mod tests {
use serialize::hex::FromHex;
#[test]
fn test_aes_256_ecb() {
let k0 =
vec!(0x00u8, 0x01u8, 0x02u8, 0x03u8, 0x04u8, 0x05u8, 0x06u8, 0x07u8,
0x08u8, 0x09u8, 0x0au8, 0x0bu8, 0x0cu8, 0x0du8, 0x0eu8, 0x0fu8,
0x10u8, 0x11u8, 0x12u8, 0x13u8, 0x14u8, 0x15u8, 0x16u8, 0x17u8,
0x18u8, 0x19u8, 0x1au8, 0x1bu8, 0x1cu8, 0x1du8, 0x1eu8, 0x1fu8);
let p0 =
vec!(0x00u8, 0x11u8, 0x22u8, 0x33u8, 0x44u8, 0x55u8, 0x66u8, 0x77u8,
0x88u8, 0x99u8, 0xaau8, 0xbbu8, 0xccu8, 0xddu8, 0xeeu8, 0xffu8);
let c0 =
vec!(0x8eu8, 0xa2u8, 0xb7u8, 0xcau8, 0x51u8, 0x67u8, 0x45u8, 0xbfu8,
0xeau8, 0xfcu8, 0x49u8, 0x90u8, 0x4bu8, 0x49u8, 0x60u8, 0x89u8);
let c = super::Crypter::new(super::Type::AES_256_ECB);
c.init(super::Mode::Encrypt, k0.as_slice(), vec![]);
c.pad(false);
let mut r0 = c.update(p0.as_slice());
r0.extend(c.finalize().into_iter());
assert!(r0 == c0);
c.init(super::Mode::Decrypt, k0.as_slice(), vec![]);
c.pad(false);
let mut p1 = c.update(r0.as_slice());
p1.extend(c.finalize().into_iter());
assert!(p1 == p0);
}
#[test]
fn test_aes_256_cbc_decrypt() {
let cr = super::Crypter::new(super::Type::AES_256_CBC);
let iv = vec![
4_u8, 223_u8, 153_u8, 219_u8, 28_u8, 142_u8, 234_u8, 68_u8, 227_u8,
69_u8, 98_u8, 107_u8, 208_u8, 14_u8, 236_u8, 60_u8, 0_u8, 0_u8,
0_u8, 0_u8, 0_u8, 0_u8, 0_u8, 0_u8, 0_u8, 0_u8, 0_u8, 0_u8, 0_u8,
0_u8, 0_u8, 0_u8
];
let data = [
143_u8, 210_u8, 75_u8, 63_u8, 214_u8, 179_u8, 155_u8,
241_u8, 242_u8, 31_u8, 154_u8, 56_u8, 198_u8, 145_u8, 192_u8, 64_u8,
2_u8, 245_u8, 167_u8, 220_u8, 55_u8, 119_u8, 233_u8, 136_u8, 139_u8,
27_u8, 71_u8, 242_u8, 119_u8, 175_u8, 65_u8, 207_u8
];
let ciphered_data = [
0x4a_u8, 0x2e_u8, 0xe5_u8, 0x6_u8, 0xbf_u8, 0xcf_u8, 0xf2_u8, 0xd7_u8,
0xea_u8, 0x2d_u8, 0xb1_u8, 0x85_u8, 0x6c_u8, 0x93_u8, 0x65_u8, 0x6f_u8
];
cr.init(super::Mode::Decrypt, &data, iv);
cr.pad(false);
let unciphered_data_1 = cr.update(&ciphered_data);
let unciphered_data_2 = cr.finalize();
let expected_unciphered_data = b"I love turtles.\x01";
assert!(unciphered_data_2.len() == 0);
assert_eq!(
unciphered_data_1.as_slice(),
expected_unciphered_data
);
}
fn cipher_test(ciphertype: super::Type, pt: &str, ct: &str, key: &str, iv: &str) {
use serialize::hex::ToHex;
let cipher = super::Crypter::new(ciphertype);
cipher.init(super::Mode::Encrypt, key.from_hex().unwrap().as_slice(), iv.from_hex().unwrap());
let expected = ct.from_hex().unwrap().as_slice().to_vec();
let mut computed = cipher.update(pt.from_hex().unwrap().as_slice());
computed.extend(cipher.finalize().into_iter());
if computed != expected {
println!("Computed: {}", computed.as_slice().to_hex());
println!("Expected: {}", expected.as_slice().to_hex());
if computed.len() != expected.len() {
println!("Lengths differ: {} in computed vs {} expected",
computed.len(), expected.len());
}
panic!("test failure");
}
}
#[test]
fn test_rc4() {
let pt = "0000000000000000000000000000000000000000000000000000000000000000000000000000";
let ct = "A68686B04D686AA107BD8D4CAB191A3EEC0A6294BC78B60F65C25CB47BD7BB3A48EFC4D26BE4";
let key = "97CD440324DA5FD1F7955C1C13B6B466";
let iv = "";
cipher_test(super::Type::RC4_128, pt, ct, key, iv);
}
#[test]
#[cfg(feature = "aes_xts")]
fn test_aes256_xts() {
let pt = "77f4ef63d734ebd028508da66c22cdebdd52ecd6ee2ab0a50bc8ad0cfd692ca5fcd4e6dedc45df7f6503f462611dc542";
let ct = "ce7d905a7776ac72f240d22aafed5e4eb7566cdc7211220e970da634ce015f131a5ecb8d400bc9e84f0b81d8725dbbc7";
let key = "b6bfef891f83b5ff073f2231267be51eb084b791fa19a154399c0684c8b2dfcb37de77d28bbda3b4180026ad640b74243b3133e7b9fae629403f6733423dae28";
let iv = "db200efb7eaaa737dbdf40babb68953f";
cipher_test(super::Type::AES_256_XTS, pt, ct, key, iv);
}
}