use std::io;
use std::fmt;
-use std::rand::{ random, task_rng, distributions };
+use std::rand::{ Rng, StdRng, SeedableRng, distributions };
use std::rand::distributions::IndependentSample;
+use serialize::hex::{ ToHex };
use crypto;
// There are all the errors that may occur when reading an encrypted and authenticated packet.
#[deriving(Show)]
pub enum ReadingError {
IOReadError(io::IoError),
- UnknownPacketTypeReadError, // If the first byte is unknown.
+ UnknownPacketTypeError, // If the first byte is unknown.
UnconsistentEncryptedSizeError,
UnconsistentDataSizeError, // The data size is not valid.
UnconsistentMACSizeError, // The MAC hasn't the correct size.
MACMismatchError, // The uncrypted received data doesn't match to the received MAC.
PaddingError, // Padding format error.
DataError, // The data are invalid.
+ InvalidTimestampError
}
// A macro to return a 'IOReadError' in case of error.
static MAX_PAYLOAD_SIZE: uint = 39;
static FIXED_PACKET_SIZE: uint = 1 + 8 + 10; // Packet type + timestamp + MAC.
-#[deriving(Show)]
+#[deriving(Show, Clone)]
pub struct PacketData {
id: u8,
payload: Vec<u8> // The size can vary from 'MIN_PAYLOAD_SIZE' to 'MAX_PAYLOAD_SIZE' bytes.
}
-#[deriving(Show)]
+#[deriving(Show, Clone)]
pub enum ErrorType {
CryptError,
AuthError
}
-#[deriving(Show)]
+#[deriving(Clone)]
pub enum PacketType {
Command(PacketData),
Answer(PacketData),
Error(ErrorType),
}
+/// Serialized packet format : |LL|P|TTTTTTTT|D...D|MMMMMMMMMM|
+/// Where:
+/// LL: Size on the following data
+/// P: Packet type:
+/// 0x00: Command
+/// OxFF: Answer
+/// 0x0A: Decrypt error
+/// 0x0B: Authentication error
+/// TTTTTTTT: Timestamp (64 bits)
+/// D...D: Encrypted data (AES-256 CBC mode) of:
+/// |I|C...C|P...P| for command and answer packet:
+/// I: Command ID
+/// C: Command payload (from 7 to 39 bytes)
+/// P: Padding from 1 to 16, |I|C...C|P...P| size must be a multiple of 16
+/// |"0000000000000000"| for error packet (16 bytes length)
+/// MMMMMMMMMM: first 10 bytes (most significant) of the HMAC-SHA256 of:
+/// |I|C...C| for command ans answer packet
+/// |"0000000000"| for error packet
+#[deriving(Show)]
pub struct Packet {
pub t: PacketType,
pub timestamp: u64
}
-impl fmt::Show for Packet {
+impl fmt::Show for PacketType {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
fn data_to_str(data: &PacketData) -> String {
- format!("id: {}, payload({}): {}", data.id, data.payload.len(), data.payload)
+ format!("id: {}, payload({}): \"{}\"", data.id, data.payload.len(), data.payload.as_slice().to_hex())
}
- match self.t {
- Command(ref data) => write!(formatter, "Command packet {{ timestamp: {}, {} }}", self.timestamp, data_to_str(data)),
- Answer(ref data) => write!(formatter, "Answer packet {{ timestamp: {}, {} }}", self.timestamp, data_to_str(data)),
- Error(error_type) => write!(formatter, "Error packet {{ timestamp: {}, errorType: {} }}", self.timestamp, error_type)
+ match self {
+ &Command(ref data) => write!(formatter, "Command {{ {} }}", data_to_str(data)),
+ &Answer(ref data) => write!(formatter, "Answer {{ {} }}", data_to_str(data)),
+ &Error(error_type) => write!(formatter, "Error {{ errorType: {} }}", error_type)
}
}
}
impl Packet {
- pub fn random_packet_data() -> PacketData {
- let mut rng = task_rng();
+ pub fn random_packet_data(seed: &[uint]) -> PacketData {
+ let mut rng = if seed.is_empty() { StdRng::new().unwrap() } else { SeedableRng::from_seed(seed) };
+ let mut payload = Vec::from_elem(distributions::Range::new(MIN_PAYLOAD_SIZE, MAX_PAYLOAD_SIZE + 1).ind_sample(&mut rng), 0u8);
+ rng.fill_bytes(payload.as_mut_slice_());
PacketData {
- id: random::<u8>(),
- payload: Vec::from_fn(distributions::Range::new(MIN_PAYLOAD_SIZE, MAX_PAYLOAD_SIZE + 1).ind_sample(&mut rng), |_| random::<u8>())
+ id: rng.gen::<u8>(),
+ payload: payload
}
}
- pub fn write(&self, output: &mut io::Writer) -> WritingResult {
+ pub fn write(&self, output: &mut io::Writer) -> WritingResult {
fn packet_data(p: &PacketData) -> Vec<u8> {
let mut d = Vec::new();
d.push(p.id);
}
pub fn read(input: &mut io::Reader) -> ReadingResult {
+ fn consume(input: &mut io::Reader, nb_byte: uint) {
+ let _ = input.read_exact(nb_byte);
+ }
+
let data_size = try_read_io!(input.read_be_u16());
- let packet_type = try_read_io!(input.read_u8());
+
+ // Read and check the packet type.
+ let packet_type = try_read_io!(input.read_u8());
+ if ![0x00, 0xFF, 0x0A, 0x0B].iter().any(|p| *p == packet_type) {
+ consume(input, data_size as uint - 1);
+ return Err(UnknownPacketTypeError)
+ }
+
let timestamp = try_read_io!(input.read_be_u64());
let mut encrypted_data = Vec::from_elem(data_size as uint - FIXED_PACKET_SIZE, 0u8);
Ok(Packet {
t: match packet_type {
- 0x00 | 0xFF => {
+ // Command or answer.
+ 0x00 | 0xFF => {
if data.len() < MIN_PAYLOAD_SIZE + 1 || data.len() > MAX_PAYLOAD_SIZE + 1 {
return Err(UnconsistentDataSizeError)
}
let pd = PacketData { id: data[0], payload: data.tail().to_vec() }; // match data.as_slice() { [id, payload..] => PacketData { id: id, payload: payload.to_vec() } };
match packet_type { 0x00 => Command(pd), _ => Answer(pd) }
},
- 0x0A | 0x0B => {
+ // Error.
+ _ => {
if data.len() != 16 {
return Err(UnconsistentDataSizeError)
} else if data != Vec::from_elem(16, '0' as u8) {
return Err(DataError)
}
match packet_type { 0x0A => Error(CryptError), _ => Error(AuthError) }
- },
- _ =>
- return Err(UnknownPacketTypeReadError)
+ }
},
timestamp: timestamp
})
projects / crypto_lab1.git / blobdiff