rainy 0.0.1

A pure-rust implementation of the Noise Protocol Framework
Documentation 
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

//! The `snow` crate aims to be a straightforward Noise Protocol implementation. See the
//! [Noise Protocol Framework Spec](https://noiseprotocol.org/noise.html) for more
//! information.
//!
//! The typical usage flow is to use [`Builder`] to construct a [`HandshakeState`], where you
//! will complete the handshake phase and convert into either a [`TransportState`] (typically
//! when done over a reliable transport where the internal message counter can be used) or
//! [`StatelessTransportState`] (when you control the message counter for unreliable transports
//! like UDP).
//!
//! # Example
//!
//! ```
//! # use snow::Error;
//! #
//! # #[cfg(any(feature = "default-resolver-crypto", feature = "ring-accelerated"))]
//! # fn try_main() -> Result<(), Error> {
//! static PATTERN: &'static str = "Noise_NN_25519_ChaChaPoly_BLAKE2s";
//!
//! let mut initiator = snow::Builder::new(PATTERN.parse()?)
//!     .build_initiator()?;
//! let mut responder = snow::Builder::new(PATTERN.parse()?)
//!     .build_responder()?;
//!
//! let (mut read_buf, mut first_msg, mut second_msg) =
//!     ([0u8; 1024], [0u8; 1024], [0u8; 1024]);
//!
//! // -> e
//! let len = initiator.write_message(&[], &mut first_msg)?;
//!
//! // responder processes the first message...
//! responder.read_message(&first_msg[..len], &mut read_buf)?;
//!
//! // <- e, ee
//! let len = responder.write_message(&[], &mut second_msg)?;
//!
//! // initiator processes the response...
//! initiator.read_message(&second_msg[..len], &mut read_buf)?;
//!
//! // NN handshake complete, transition into transport mode.
//! let initiator = initiator.into_transport_mode();
//! let responder = responder.into_transport_mode();
//! #     Ok(())
//! # }
//! #
//! # #[cfg(not(any(feature = "default-resolver-crypto", feature = "ring-accelerated")))]
//! # fn try_main() -> Result<(), ()> { Ok(()) }
//! #
//! # fn main() {
//! #     try_main().unwrap();
//! # }
//! ```
//!
//! See `examples/simple.rs` for a more complete TCP client/server example with static keys.
//! # Crypto
//!
//! Cryptographic providers are swappable through `Builder::with_resolver()`, but by default
//! it chooses select, artisanal pure-Rust implementations (see `Cargo.toml` for a quick
//! overview).
//!
//! ### Other Providers
//!
//! #### ring
//!
//! [ring](https://github.com/briansmith/ring) is a crypto library based off of BoringSSL
//! and is significantly faster than most of the pure-Rust implementations.
//!
//! If you enable the `ring-resolver` feature, Snow will include a `resolvers::ring` module
//! as well as a `RingAcceleratedResolver` available to be used with
//! `Builder::with_resolver()`.
//!
//! If you enable the `ring-accelerated` feature, Snow will default to choosing `ring`'s
//! crypto implementations when available.
//!
//! ### Resolver primitives supported
//!
//! |                          | default          | ring               |
//! | -----------------------: | :--------------: | :----------------: |
//! |     CSPRNG               | ✔️               | ✔️                 |
//! |      25519               | ✔️               | ✔️                 |
//! |        448               |                  |                    |
//! |      P-256<sup>🏁</sup>  | ✔️               |                    |
//! |     AESGCM               | ✔️               | ✔️                 |
//! | ChaChaPoly               | ✔️               | ✔️                 |
//! | XChaChaPoly<sup>🏁</sup> | ✔️               |                    |
//! |     SHA256               | ✔️               | ✔️                 |
//! |     SHA512               | ✔️               | ✔️                 |
//! |    BLAKE2s               | ✔️               |                    |
//! |    BLAKE2b               | ✔️               |                    |
//!
//! 🏁 P-256 and XChaChaPoly are not in the official specification of Noise, and thus need to be enabled
//! via the feature flags `use-p256` and `use-xchacha20poly1305`, respectively.
//!
//! ## `no_std` support and feature selection
//!
//! Snow can be used in `no_std` environments if `alloc` is provided.
//!
//! By default, Snow uses the standard library, default crypto resolver and a selected collection
//! of crypto primitives. To use Snow in `no_std` environments or make other kinds of customized
//! setups, use Snow with `default-features = false`. This way you will individually select
//! the components you wish to use. `default-resolver` is the only built-in resolver that
//! currently supports `no_std`.
//!
//! To use a custom setup with `default-resolver`, enable your desired selection of cryptographic primitives:
//!
//! |             | Primitive                  | Feature flag           |
//! | ----------: | :------------------------- | :--------------------- |
//! | **DHs**     | Curve25519                 | `use-curve25519`       |
//! |             | P-256<sup>:🏁:</sup>       | `use-p256`             |
//! | **Ciphers** | AES-GCM                    | `use-aes-gcm`          |
//! |             | ChaChaPoly                 | `use-chacha20poly1305` |
//! |             | XChaChaPoly<sup>:🏁:</sup> | `use-xchacha20poly1305`|
//! | **Hashes**  | SHA-256                    | `use-sha2`             |
//! |             | SHA-512                    | `use-sha2`             |
//! |             | BLAKE2s                    | `use-blake2`           |
//! |             | BLAKE2b                    | `use-blake2`           |
//!
//! 🏁 XChaChaPoly and P-256 are not in the official specification of Noise, but they are supported
//! by Snow.

#![warn(missing_docs)]
#![cfg_attr(not(feature = "std"), no_std)]

#[cfg(not(feature = "std"))]
extern crate alloc;

// Make sure the user is running a supported configuration.
#[cfg(feature = "default-resolver")]
#[cfg(any(
    not(any(feature = "use-curve25519")),
    not(any(
        feature = "use-aes-gcm",
        feature = "use-chacha20poly1305",
        feature = "use-xchacha20poly1305"
    )),
    not(any(feature = "use-sha2", feature = "use-blake2"))
))]
compile_error!(
    "Valid selection of crypto primitived must be enabled when using feature 'default-resolver'.
    Enable at least one DH feature, one Cipher feature and one Hash feature. Check README.md for details."
);

macro_rules! copy_slices {
    ($inslice:expr, $outslice:expr) => {
        $outslice[..$inslice.len()].copy_from_slice(&$inslice[..])
    };
}

macro_rules! static_slice {
    ($_type:ty: $($item:expr),*) => ({
        static STATIC_SLICE: &'static [$_type] = &[$($item),*];
        STATIC_SLICE
    });
}

mod builder;
mod cipherstate;
mod constants;
pub mod error;
mod handshakestate;
mod stateless_transportstate;
mod symmetricstate;
mod transportstate;
mod utils;

pub mod params;
pub mod resolvers;
pub mod types;

pub use crate::{
    builder::{Builder, Keypair},
    error::Error,
    handshakestate::HandshakeState,
    stateless_transportstate::StatelessTransportState,
    transportstate::TransportState,
};