Struct SecretBytes 

pub struct SecretBytes(/* private fields */);

A secret’s bytes. Zeroised on drop, prints as [redacted], and implements neither Display, Serialize nor Clone: a secret that can be formatted, serialised or copied is a secret that ends up in a log line, a JSON body, or a buffer nobody cleared.

Each absence below is paired with the same operation on a type that does allow it, so a case that stopped compiling for the wrong reason — a renamed import, a typo — would fail its pair and be noticed.

Not Display. {} is how a value reaches a log line by accident:

let secret = SecretBytes::new(b"hunter2".to_vec());
println!("{secret}");

let secret = SecretBytes::new(b"hunter2".to_vec());
// `Debug` is implemented, and redacts.
assert_eq!(format!("{secret:?}"), "SecretBytes([redacted])");

Not Clone. A copy is a second buffer nobody is tracking:

let secret = SecretBytes::new(b"hunter2".to_vec());
let _copy = secret.clone();

let secret = SecretBytes::new(b"hunter2".to_vec());
// Moving is fine: there is still exactly one buffer.
let moved = secret;
assert_eq!(moved.expose(), b"hunter2");

Not Serialize. Serialisation is how a secret reaches a JSON body:

fn needs_serialize<T: serde::Serialize>(_value: &T) {}
let secret = SecretBytes::new(b"hunter2".to_vec());
needs_serialize(&secret);

fn needs_serialize<T: serde::Serialize>(_value: &T) {}
// The bound itself is satisfiable — it is `SecretBytes` that refuses it.
needs_serialize(&"an ordinary string");

Implementations

impl SecretBytes

pub fn new(bytes: Vec<u8>) -> Self

pub fn expose(&self) -> &[u8]

The bytes. Named expose so a reader has to notice.

pub fn expose_str(&self) -> Result<&str, SecretsError>

The bytes as text, when the secret is one (an API key).

Errors

SecretsError::Invalid when the value is not UTF-8.

Trait Implementations

impl Debug for SecretBytes

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&str> for SecretBytes

fn from(value: &str) -> Self

Converts to this type from the input type.