sheave_core/handshake.rs
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421
//! # Types for the handshake step in RTMP.
//!
//! In RTMP, first, both sides are required doing handshake.
//! It is done respectively following steps:
//!
//! 1. Specifies RTMP version.
//! 2. Exchanges handshake data each other.
//! 3. Returns partner's handshake data.
//!
//! ## RTMP version
//!
//! 1 byte to specify a kind of encryption.
//! Default is 3.
//! This means doing handshake as the Raw RTMP, that is, not to encrypt.
//! Server should respond 3 if encryption specified by client has not implemented.
//! In this case, client can either degrade version to 3 or disconnect with server.
//!
//! ## Handshake
//!
//! 1536 bytes of actual handshake data.
//! Note this can be imprinted HMAC-SHA256 diegst/signature according to version of Flash Player/Flash Media Server.
//! Concretely, it is imprinted when respective version is following:
//!
//! * Flash Player: `>= 9`
//! * Flash Media Server: `>= 3`
//!
//! ### Examples
//!
//! Both sides are required taking following steps each version.
//!
//! * Below Flash Player 9/Flash Media Server 3
//!
//! ```rust
//! use std::time::Duration;
//! use sheave_core::handshake::{
//! Handshake,
//! Version
//! };
//!
//! let handshake = Handshake::new(Duration::default(), Version::UNSIGNED);
//! ```
//!
//! * And above Flash Player 9/Flash Media Server 3
//!
//! ```rust
//! use std::time::Duration;
//! use sheave_core::handshake::{
//! Handshake,
//! Version,
//! EncryptionAlgorithm
//! };
//!
//! // In a case of exchanging client-side request with server-side response.
//! let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
//! client_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
//! let mut key: Vec<u8> = Vec::new();
//! key.extend_from_slice(Handshake::SERVER_KEY);
//! key.extend_from_slice(Handshake::COMMON_KEY);
//! client_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
//! assert!(client_handshake.did_signature_match(EncryptionAlgorithm::NotEncrypted, key.as_slice()));
//!
//! // In a case of exchanging server-side request with client-side response.
//! let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
//! server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
//! let mut key: Vec<u8> = Vec::new();
//! key.extend_from_slice(Handshake::CLIENT_KEY);
//! key.extend_from_slice(Handshake::COMMON_KEY);
//! server_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
//! assert!(server_handshake.did_signature_match(EncryptionAlgorithm::NotEncrypted, key.as_slice()));
//! ```
//!
//! ### Encryption
//!
//! Currently, to implement handshake encryption isn't planned following causes:
//!
//! 1. Connected socket is in full view from outside. This is insecure though chunk is encrypted.
//! 2. If chunk encryption is implemented on RTMPTS, To decrypt chunk/socket takes both sides time in no small way. This is inefficient for real-time communications.
//! 3. Therefore I'm thinking we should leave encryption to only HTTPS.
mod version;
mod encryption_algorithm;
use std::time::Duration;
use rand::{
Fill,
thread_rng
};
use digest::{
CtOutput,
OutputSizeUser
};
use sha2::Sha256;
use hmac::{
Hmac,
Mac
};
pub use self::{
version::Version,
encryption_algorithm::EncryptionAlgorithm
};
type HmacSha256 = Hmac<Sha256>;
/// The 1536 bytes handshake data.
/// This respectively consists of following parts:
///
/// |Range|Representation|
/// | :- | :- |
/// |First 4 bytes|Timestamp (in milliseconds)|
/// |Second 4 bytes|Flash Player version/Flash Media Server version|
/// |Remained bytes|Randoms for handshake (may be contained digest/signature)|
#[derive(Debug)]
pub struct Handshake([u8; 1536]);
impl Handshake {
/// The key which is used to imprint ant client-side digest.
pub const CLIENT_KEY: &'static [u8] = b"Genuine Adobe Flash Player 001";
/// The key which is used to imprint any server-side digest.
pub const SERVER_KEY: &'static [u8] = b"Genuine Adobe Flash Media Server 001";
/// The key which is used to imprint any signature.
/// Both sides are required to contain this into a key of signature.
pub const COMMON_KEY: &'static [u8] = &[
0xF0, 0xEE, 0xC2, 0x4A, 0x80, 0x68, 0xBE, 0xE8, 0x2E, 0x00, 0xD0, 0xD1, 0x02, 0x9E, 0x7E, 0x57, 0x6E, 0xEC, 0x5D, 0x2D, 0x29, 0x80, 0x6F, 0xAB, 0x93, 0xB8, 0xE6, 0x36, 0xCF, 0xEB, 0x31, 0xAE
];
/// Constructs handshake data.
///
/// # Examples
///
/// ```rust
/// use std::time::Duration;
/// use sheave_core::handshake::{
/// Handshake,
/// Version,
/// EncryptionAlgorithm
/// };
///
/// // If you are a client.
/// let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
/// // If you are a server.
/// let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
/// ```
pub fn new(timestamp: Duration, version: Version) -> Self {
let mut handshake_bytes: [u8; 1536] = [0; 1536];
let timestamp_bytes = (timestamp.as_millis() as u32).to_be_bytes();
let version_bytes: [u8; 4] = version.into();
handshake_bytes[..4].copy_from_slice(timestamp_bytes.as_slice());
handshake_bytes[4..8].copy_from_slice(version_bytes.as_slice());
handshake_bytes[8..].try_fill(&mut thread_rng()).unwrap();
Self(handshake_bytes)
}
/// Gets all handshake data.
pub fn get_bytes(&self) -> &[u8] {
&self.0
}
/// Gets first 4 bytes as timestamp.
pub fn get_timestamp(&self) -> Duration {
let mut timestamp_bytes: [u8; 4] = [0; 4];
timestamp_bytes.copy_from_slice(&self.0[..4]);
Duration::from_millis(u32::from_be_bytes(timestamp_bytes) as u64)
}
/// Gets second 4 bytes as Flash Player version/Flash Media Server version.
pub fn get_version(&self) -> Version {
let mut version_bytes: [u8; 4] = [0; 4];
version_bytes.copy_from_slice(&self.0[4..8]);
version_bytes.into()
}
fn get_digest_position(&self, encryption_algorithm: EncryptionAlgorithm) -> usize {
let offset: usize;
let adder: usize;
match encryption_algorithm {
EncryptionAlgorithm::NotEncrypted => {
offset = 8;
adder = 12;
},
_ => {
offset = 772;
adder = 776;
}
}
self.0[offset..(offset + 4)].iter().map(|byte| usize::from(*byte)).sum::<usize>() % 728 + adder
}
fn get_digest_message(&self, encryption_algorithm: EncryptionAlgorithm) -> Vec<u8> {
let digest_position = self.get_digest_position(encryption_algorithm);
let mut message: Vec<u8> = Vec::new();
message.extend_from_slice(&self.0[..digest_position]);
message.extend_from_slice(&self.0[(digest_position + HmacSha256::output_size())..]);
message
}
fn compute_digest(&self, encryption_algorithm: EncryptionAlgorithm, key: &[u8]) -> CtOutput<HmacSha256> {
let message = self.get_digest_message(encryption_algorithm);
let mut hmac = HmacSha256::new_from_slice(key).unwrap();
hmac.update(message.as_slice());
hmac.finalize()
}
/// Gets a digest contained in this handshake bytes.
/// Note its place is different by whether encrypts handshake bytes.
///
/// # Examples
///
/// ```rust
/// use std::time::Instant;
/// use sheave_core::handshake::{
/// EncryptionAlgorithm,
/// Handshake,
/// Version
/// };
///
/// let handshake = Handshake::new(Instant::now().elapsed(), Version::LATEST_CLIENT);
///
/// assert_ne!(handshake.get_digest(EncryptionAlgorithm::NotEncrypted), handshake.get_digest(EncryptionAlgorithm::DiffieHellman))
/// ```
pub fn get_digest(&self, encryption_algorithm: EncryptionAlgorithm) -> &[u8] {
let digest_position = self.get_digest_position(encryption_algorithm);
&self.0[digest_position..(digest_position + HmacSha256::output_size())]
}
/// Imprints an HMAC-SHA256 digest into handshake data.
///
/// # Examples
///
/// ```rust
/// use std::time::Duration;
/// use sheave_core::handshake::{
/// Handshake,
/// Version,
/// EncryptionAlgorithm
/// };
///
/// // In a case of sending client-side request.
/// let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
/// client_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
///
/// // In a case of sending server-side request.
/// let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
/// server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
/// ```
pub fn imprint_digest(&mut self, encryption_algorithm: EncryptionAlgorithm, key: &[u8]) {
let digest_position = self.get_digest_position(encryption_algorithm);
let digest = self.compute_digest(encryption_algorithm, key);
self.0[digest_position..(digest_position + HmacSha256::output_size())].copy_from_slice(digest.into_bytes().as_slice());
}
/// Checks whether imprinted digest matches with one computed by given key.
///
/// # Examples
///
/// ```rust
/// use std::time::Duration;
/// use sheave_core::handshake::{
/// Handshake,
/// Version,
/// EncryptionAlgorithm
/// };
///
/// // In a case of checking server-side request.
/// let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
/// server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
/// assert!(server_handshake.did_digest_match(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY));
///
/// // In a case of checking client-side request.
/// let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
/// server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
/// assert!(server_handshake.did_digest_match(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY));
/// ```
pub fn did_digest_match(&self, encryption_algorithm: EncryptionAlgorithm, key: &[u8]) -> bool {
let expected = self.compute_digest(encryption_algorithm, key);
self.get_digest(encryption_algorithm) == expected.into_bytes().as_slice()
}
fn get_signature_position(&self) -> usize {
self.0.len() - HmacSha256::output_size()
}
fn get_signature_message(&self) -> &[u8] {
let signature_position = self.get_signature_position();
&self.0[..signature_position]
}
fn compute_signature(&self, encryption_algorithm: EncryptionAlgorithm, key: &[u8]) -> CtOutput<HmacSha256> {
let digest = self.get_digest(encryption_algorithm);
let mut hmac = HmacSha256::new_from_slice(key).unwrap();
hmac.update(digest);
let key_from_digest = hmac.finalize();
let message = self.get_signature_message();
let mut hmac = HmacSha256::new_from_slice(key_from_digest.into_bytes().as_slice()).unwrap();
hmac.update(message);
hmac.finalize()
}
/// Gets a signature contained into this handshake bytes.
pub fn get_signature(&self) -> &[u8] {
let signature_position = self.get_signature_position();
&self.0[signature_position..]
}
/// Imprints an HMAC-SHA256 signature into handshake data.
///
/// # Examples
///
/// ```rust
/// use std::time::Duration;
/// use sheave_core::handshake::{
/// Handshake,
/// Version,
/// EncryptionAlgorithm
/// };
///
/// // In a case of exchanging client-side request with server-side response.
/// let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
/// client_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
/// let mut key: Vec<u8> = Vec::new();
/// key.extend_from_slice(Handshake::SERVER_KEY);
/// key.extend_from_slice(Handshake::COMMON_KEY);
/// client_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
///
/// // In a case of exchanging server-side request with client-side response.
/// let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
/// server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
/// let mut key: Vec<u8> = Vec::new();
/// key.extend_from_slice(Handshake::CLIENT_KEY);
/// key.extend_from_slice(Handshake::COMMON_KEY);
/// server_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
/// ```
pub fn imprint_signature(&mut self, encryption_algorithm: EncryptionAlgorithm, key: &[u8]) {
let signature_position = self.get_signature_position();
let signature = self.compute_signature(encryption_algorithm, key);
self.0[signature_position..].copy_from_slice(signature.into_bytes().as_slice());
}
/// Checks whether imprinted signature matches one computed by given key.
///
/// # Examples
///
/// ```rust
/// use std::time::Duration;
/// use sheave_core::handshake::{
/// Handshake,
/// Version,
/// EncryptionAlgorithm
/// };
///
/// // In a case of checking client-side response.
/// let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
/// client_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
/// let mut key: Vec<u8> = Vec::new();
/// key.extend_from_slice(Handshake::SERVER_KEY);
/// key.extend_from_slice(Handshake::COMMON_KEY);
/// client_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
/// assert!(client_handshake.did_signature_match(EncryptionAlgorithm::NotEncrypted, key.as_slice()));
///
/// // In a case of checking server-side response.
/// let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
/// server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
/// let mut key: Vec<u8> = Vec::new();
/// key.extend_from_slice(Handshake::CLIENT_KEY);
/// key.extend_from_slice(Handshake::COMMON_KEY);
/// server_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
/// assert!(server_handshake.did_signature_match(EncryptionAlgorithm::NotEncrypted, key.as_slice()));
/// ```
pub fn did_signature_match(&self, encryption_algorithm: EncryptionAlgorithm, key: &[u8]) -> bool {
let expected = self.compute_signature(encryption_algorithm, key);
self.get_signature() == expected.into_bytes().as_slice()
}
}
impl From<[u8; 1536]> for Handshake {
fn from(handshake_bytes: [u8; 1536]) -> Self {
Self(handshake_bytes)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn did_client_digest_match() {
let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
client_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
assert!(client_handshake.did_digest_match(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY))
}
#[test]
fn did_server_digest_match() {
let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
assert!(server_handshake.did_digest_match(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY))
}
#[test]
fn did_client_signature_match() {
let mut client_handshake = Handshake::new(Duration::default(), Version::LATEST_CLIENT);
client_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::CLIENT_KEY);
let mut key: Vec<u8> = Vec::new();
key.extend_from_slice(Handshake::SERVER_KEY);
key.extend_from_slice(Handshake::COMMON_KEY);
client_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
assert!(client_handshake.did_signature_match(EncryptionAlgorithm::NotEncrypted, key.as_slice()))
}
#[test]
fn did_server_signature_match() {
let mut server_handshake = Handshake::new(Duration::default(), Version::LATEST_SERVER);
server_handshake.imprint_digest(EncryptionAlgorithm::NotEncrypted, Handshake::SERVER_KEY);
let mut key: Vec<u8> = Vec::new();
key.extend_from_slice(Handshake::CLIENT_KEY);
key.extend_from_slice(Handshake::COMMON_KEY);
server_handshake.imprint_signature(EncryptionAlgorithm::NotEncrypted, key.as_slice());
assert!(server_handshake.did_signature_match(EncryptionAlgorithm::NotEncrypted, key.as_slice()))
}
}