Struct Secret 

pub struct Secret<T>(/* private fields */);

A wrapper for secret values that prevents accidental leakage.

• Debug and Display show [REDACTED]
• Zeroized on drop
• Access requires explicit expose() call

Type Constraints

Only use with flat data types that have no pointers (e.g. [u8; N]). See module-level documentation for details.

Implementations

impl<T> Secret<T>

pub const fn new(value: T) -> Self

Creates a new Secret wrapping the given value.

pub fn expose<R>(&self, f: impl for<'a> FnOnce(&'a T) -> R) -> R

Exposes the secret value for read-only access within a closure.

Note

The closure uses a higher-ranked trait bound (for<'a>) to prevent the returned value from containing references to the secret data. This ensures the reference cannot escape the closure scope. However, this does not prevent copying or cloning the secret value within the closure (e.g., secret.expose(|s| s.clone())). Callers should avoid leaking secrets through such patterns.

Additionally, any temporaries derived from the secret (e.g. s.as_slice()) may leave secret data on the stack that will not be automatically zeroized. Callers should wrap such temporaries in zeroize::Zeroizing if they contain sensitive data.

pub fn expose_unwrap(self) -> T

Consumes the Secret and returns the inner value, zeroizing the original memory location.

Use this when you need to transfer ownership of the secret value (e.g., for APIs that consume the value).

Trait Implementations

impl<T: Clone> Clone for Secret<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T> Debug for Secret<T>

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

Formats the value using the given formatter.

impl<T> Display for Secret<T>

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

Formats the value using the given formatter.

impl<T> Drop for Secret<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: CtEq> PartialEq for Secret<T>

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: CtEq> Eq for Secret<T>

impl<T> ZeroizeOnDrop for Secret<T>