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// LCOV_EXCL_LINE
//! Protected-access memory for cryptographic secrets.
//!
//! Provides a convenient way to allocate and access memory for
//! secret data. Data is protected from being read from and/or written
//! to outside of limited scopes, where it may be accessed through
//! pointer semantics or slice semantics.
//!
//! Memory allocations are protected by guard pages before after the
//! allocation, an underflow canary (to catch underflows before a
//! guard page), and are zeroed out when freed.
//!
//! # Core dumps
//!
//! This library explicitly disables core dumps in release builds that
//! target UNIX systems. This is done to avoid retrival of a secret
//! from it. You can still opt-in on allowing code dumps with
//! `allow-coredumps` feature flag.
//!
//! # Example: generating crytographic keys
//!
//! ```
//! use secrets::Secret;
//!
//! Secret::<[u8; 16]>::random(|s| {
//! // use `s` as if it were a `&mut [u8; 16]`
//! //
//! // the memory is `mlock(2)`ed and will be zeroed when this closure
//! // exits
//! });
//! ```
//!
//! # Example: load a master key from disk and generate subkeys from it
//!
//! ```
//! use std::fs::File;
//! use std::io::Read;
//!
//! use libsodium_sys as sodium;
//! use secrets::SecretBox;
//!
//! const KEY_LEN : usize = sodium::crypto_kdf_KEYBYTES as _;
//! const CTX_LEN : usize = sodium::crypto_kdf_CONTEXTBYTES as _;
//!
//! const CONTEXT : &[u8; CTX_LEN] = b"example\0";
//!
//! fn derive_subkey(
//! key: &[u8; KEY_LEN],
//! context: &[u8; CTX_LEN],
//! subkey_id: u64,
//! subkey: &mut [u8],
//! ) {
//! unsafe {
//! libsodium_sys::crypto_kdf_derive_from_key(
//! subkey.as_mut_ptr(),
//! subkey.len(),
//! subkey_id,
//! context.as_ptr() as *const i8,
//! key.as_ptr()
//! );
//! }
//! }
//!
//! let master_key = SecretBox::<[u8; KEY_LEN]>::try_new(|mut s| {
//! File::open("example/master_key/key")?.read_exact(s)
//! })?;
//!
//! let subkey_0 = SecretBox::<[u8; 16]>::new(|mut s| {
//! derive_subkey(&master_key.borrow(), CONTEXT, 0, s);
//! });
//!
//! let subkey_1 = SecretBox::<[u8; 16]>::new(|mut s| {
//! derive_subkey(&master_key.borrow(), CONTEXT, 1, s);
//! });
//!
//! assert_ne!(
//! subkey_0.borrow(),
//! subkey_1.borrow(),
//! );
//!
//! # Ok::<(), std::io::Error>(())
//! ```
//!
//! # Example: securely storing a decrypted ciphertext in memory
//!
//! ```
//! use std::fs::File;
//! use std::io::Read;
//!
//! use libsodium_sys as sodium;
//! use secrets::{SecretBox, SecretVec};
//!
//! const KEY_LEN : usize = sodium::crypto_secretbox_KEYBYTES as _;
//! const NONCE_LEN : usize = sodium::crypto_secretbox_NONCEBYTES as _;
//! const MAC_LEN : usize = sodium::crypto_secretbox_MACBYTES as _;
//!
//! let mut key = SecretBox::<[u8; KEY_LEN]>::zero();
//! let mut nonce = [0; NONCE_LEN];
//! let mut ciphertext = Vec::new();
//!
//! File::open("example/decrypted_ciphertext/key")?
//! .read_exact(key.borrow_mut().as_mut())?;
//!
//! File::open("example/decrypted_ciphertext/nonce")?
//! .read_exact(&mut nonce)?;
//!
//! File::open("example/decrypted_ciphertext/ciphertext")?
//! .read_to_end(&mut ciphertext)?;
//!
//! let plaintext = SecretVec::<u8>::new(ciphertext.len() - MAC_LEN, |mut s| {
//! if -1 == unsafe {
//! sodium::crypto_secretbox_open_easy(
//! s.as_mut_ptr(),
//! ciphertext.as_ptr(),
//! ciphertext.len() as _,
//! nonce.as_ptr(),
//! key.borrow().as_ptr(),
//! )
//! } {
//! panic!("failed to authenticate ciphertext during decryption");
//! }
//! });
//!
//! assert_eq!(
//! *b"attack at dawn",
//! *plaintext.borrow(),
//! );
//!
//! # Ok::<(), std::io::Error>(())
//! ```
// TODO: examples directory
// TODO: replace sodium::fail() with mocks for testing cleanliness
#![warn(future_incompatible)]
#![warn(nonstandard_style)]
#![warn(rust_2018_compatibility)]
#![warn(rust_2018_idioms)]
#![warn(rust_2021_compatibility)]
#![warn(unused)]
#![warn(bare_trait_objects)]
#![warn(dead_code)]
#![warn(missing_copy_implementations)]
#![warn(missing_debug_implementations)]
#![warn(missing_docs)]
#![warn(single_use_lifetimes)]
#![warn(trivial_casts)]
#![warn(trivial_numeric_casts)]
#![warn(unreachable_pub)]
#![warn(unstable_features)]
#![warn(unused_import_braces)]
#![warn(unused_lifetimes)]
#![warn(unused_qualifications)]
#![warn(unused_results)]
#![warn(unsafe_code)]
#![warn(variant_size_differences)]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::all))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::pedantic))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::nursery))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::clone_on_ref_ptr))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::decimal_literal_representation))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::else_if_without_else))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::float_arithmetic))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::float_cmp_const))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::indexing_slicing))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::mem_forget))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::missing_docs_in_private_items))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::multiple_inherent_impl))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::multiple_inherent_impl))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::print_stdout))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::unwrap_used))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::shadow_reuse))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::shadow_same))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::unimplemented))]
#![cfg_attr(feature = "cargo-clippy", warn(clippy::use_debug))]
#![cfg_attr(feature = "cargo-clippy", allow(clippy::module_name_repetitions))]
#![cfg_attr(feature = "cargo-clippy", allow(clippy::must_use_candidate))]
// disabled due to https://github.com/rust-lang/rust-clippy/issues/5369
#![cfg_attr(feature = "cargo-clippy", allow(clippy::redundant_pub_crate))]
// disabled due to https://github.com/rust-lang/rust/issues/69952
#![cfg_attr(feature = "cargo-clippy", allow(clippy::wildcard_imports))]
/// Macros for ensuring code correctness inspired by [sqlite].
///
/// [sqlite]: https://www.sqlite.org/assert.html
#[cfg(profile = "debug")]
#[macro_use]
mod assert {
#![allow(unused_macros)]
/// Results in an `assert!` in debug builds but is a no-op in
/// coverage and release builds, since we have extraordinarily high
/// guarantees that it is impossible for this condition to happen in
/// released code.
macro_rules! proven {
($($arg:tt)*) => {
assert!($($arg)*)
};
}
/// This is intended to be used in a conditional expression, and
/// must have the negative case handled in the event that we're wrong;
/// in debug builds it performs an `assert!`, in coverage builds it
/// expands to `true`, and in production builds it evaluates to the
/// condition itself.
macro_rules! always {
($cond:expr) => { {
assert!($cond); true
} };
($cond:expr, $($arg:tt)*) => {
assert!($cond, $($arg)*)
};
}
/// The logical opposite of `always`
macro_rules! never {
($cond:expr) => { {
assert!(!$cond); false
} };
($cond:expr, $($arg:tt)*) => {
assert!(!$cond, $($arg)*)
};
}
/// Ensures, for code-coverage purposes, that we have tests for
/// which the condition provided evaluates to `true`, this allows
/// us to ensure at the source location itself that known edge cases
/// are considered and tested; in debug and release builds it's a
/// no-op, and in coverage builds it does some work that can't be
/// optimized away, so the coverage tool can ensure that that work
/// is performed at least once (and therefore the condition was
/// tested).
macro_rules! tested {
($cond:expr) => ()
}
}
/// See above.
#[cfg(profile = "coverage")]
#[macro_use]
mod assert {
#![allow(unused_macros)]
macro_rules! proven {
($($arg:tt)*) => ();
}
macro_rules! always {
($cond:expr) => {
true
};
($cond:expr, $($arg:tt)*) => {
assert!($cond, $($arg)*)
};
}
macro_rules! never {
($cond:expr) => {
false
};
($cond:expr, $($arg:tt)*) => {
assert!(!$cond, $($arg)*)
};
}
// Well, this sucks. The intent here is that code coverage tools
// will be able to detect if this line isn't run due to the
// condition never being satisfied. But right now, they aren't smart
// enough to do it due to how coverage is tracked. Macros are
// expanded, but their line hits aren't tracked separately. So just
// evaluating the condition is enough for the whole thing to be
// considered run.
//
// Still, we'll leave this in place with the hopes that some day it
// will start working and we'll live in a happy world where we can
// verify edge cases are tracked.
macro_rules! tested {
($cond:expr) => {
if $cond {
// TODO: replace with [`test::black_box`] when stable
let _ = crate::ffi::sodium::memcmp(&[], &[]);
}
};
}
}
/// See above.
#[cfg(profile = "release")]
#[macro_use]
mod assert {
#![allow(unused_macros)]
macro_rules! proven {
($($arg:tt)*) => ();
}
macro_rules! always {
($cond:expr) => {
$cond
};
($cond:expr, $($arg:tt)*) => {
assert!($cond, $($arg)*)
};
}
macro_rules! never {
($cond:expr) => {
$cond
};
($cond:expr, $($arg:tt)*) => {
assert!(!$cond, $($arg)*)
};
}
macro_rules! tested {
($cond:expr) => ();
}
}
/// Container for FFI-related code.
mod ffi {
pub(crate) mod sodium;
}
/// Container for `Box`.
mod boxed;
/// Container for `Secret`.
mod secret;
/// Container for `SecretBox`.
mod secret_box;
/// Container for `SecretVec`.
mod secret_vec;
pub mod traits;
pub use secret::Secret;
pub use secret_box::SecretBox;
pub use secret_vec::SecretVec;