reliakit-secret

Secret-safe wrappers for Rust values that should not leak through formatting or diagnostics.

reliakit-secret provides Secret<T>, a small wrapper that redacts its inner value in Debug and Display output. Access to the wrapped value is explicit through ExposeSecret.

The crate has no dependencies and forbids unsafe code.

What This Crate Does

This crate helps prevent accidental secret leaks in logs, error messages, debug output, and diagnostic reports.

Instead of passing a raw password, token, or API key through a public API, wrap it as a Secret<T>:

use reliakit_secret::{ExposeSecret, Secret};

fn connect(token: Secret<String>) {
    assert_eq!(format!("{token:?}"), "Secret([REDACTED])");
    let raw_token = token.expose_secret();
    assert!(!raw_token.is_empty());
}

What This Crate Does Not Do

This crate does not provide memory zeroization, encryption, process isolation, or protection against memory inspection. It is a formatting and diagnostics safety primitive.

Installation

[dependencies]
reliakit-secret = "0.1"

For no_std without allocation:

[dependencies]
reliakit-secret = { version = "0.1", default-features = false }

For no_std with string-backed secrets:

[dependencies]
reliakit-secret = { version = "0.1", default-features = false, features = ["alloc"] }

Examples

Generic secret

use reliakit_secret::{ExposeSecret, Secret};

let token = Secret::new("ghp_example_token");

assert_eq!(format!("{token:?}"), "Secret([REDACTED])");
assert_eq!(format!("{token}"), "[REDACTED]");
assert_eq!(token.expose_secret(), &"ghp_example_token");

String-backed secret

use reliakit_secret::{ExposeSecret, SecretString};

let password = SecretString::from_string("correct horse battery staple");

assert_eq!(password.expose_secret(), "correct horse battery staple");
assert_eq!(password.expose_str(), "correct horse battery staple");
assert_eq!(password.to_string(), "[REDACTED]");

Consuming a secret

use reliakit_secret::Secret;

let secret = Secret::new(String::from("token"));
let token = secret.into_inner();

assert_eq!(token, "token");

Available Types

Type	Description
`Secret<T>`	Generic wrapper that redacts `Debug` and `Display`
`SecretString`	`String`-backed secret, available with `std` or `alloc`
`ExposeSecret<T>`	Trait for explicit shared access
`ExposeSecretMut<T>`	Trait for explicit mutable access

Feature Flags

Flag	Default	Description
`std`	yes	Enables the standard library
`alloc`	no	Enables `SecretString` without `std`

`no_std`

The crate supports no_std.

Generic Secret<T> works without allocation. SecretString requires alloc or std.

Safety

This crate is #![forbid(unsafe_code)].

Minimum Supported Rust Version

Rust 1.85 and newer. No nightly features are used.

Status

Active. The crate is intentionally small and focused on formatting-safe secret wrappers.

License

Licensed under the MIT License.

reliakit-secret 0.1.2