Struct SealedDynamic 

pub struct SealedDynamic<T: SealedPayload> { /* private fields */ }

Available on crate feature sealed only.

A variable-length secret (Vec<u8> or String) held encrypted in RAM while idle, opened for one closure call at a time. The sealed counterpart of Dynamic. Requires the sealed feature.

The ciphertext lives in an exact-size Box<[u8]>. Each access decrypts into an exact-capacity Dynamic that its Drop wipes. As with SealedFixed there is no expose_secret and no RevealSecret impl.

use secure_gate::{Dynamic, Prekey, SealedDynamic};

let prekey = Prekey::new();
let mut pw = SealedDynamic::seal(Dynamic::new(String::from("hunter2")), &prekey);
pw.with_secret(|s: &String| assert_eq!(s, "hunter2"));
pw.with_secret_mut(|s: &mut str| s.make_ascii_uppercase());
pw.with_secret(|s| assert_eq!(s, "HUNTER2"));

Panics

Every access panics if the sealed bytes fail to authenticate. The temporary is wiped and the stack below the call scrubbed before the panic continues.

Implementations

impl<T: SealedPayload> SealedDynamic<T>

pub fn seal(secret: Dynamic<T>, prekey: &Arc<Prekey>) -> Self

Seals secret under prekey. The plain wrapper is consumed and wiped on drop.

pub fn with_secret<F, R>(&self, f: F) -> R

where F: FnOnce(&T) -> R,

Decrypts into a temporary for the length of f, then wipes the temporary.

pub fn with_secret_mut<F, R>(&mut self, f: F) -> R

where F: FnOnce(&mut T::Mut) -> R,

Decrypts into a temporary, lets f change it in place, then seals the result under a fresh salt and wipes the temporary.

f gets &mut [u8] or &mut str, never &mut Vec or &mut String: the length is fixed, so the buffer can never reallocate and abandon an unwiped copy of the plaintext. To change the length, unseal, edit, and seal again.

If f panics, the temporary is still wiped, the stack scrubbed, and the sealed value left as it was.

pub fn unseal(self) -> Dynamic<T>

Opens the secret back into a plain Dynamic. Protection from sealing ends here; the returned wrapper still wipes on drop.

pub fn len(&self) -> usize

The secret’s length in bytes. Length can itself be sensitive for passwords; it is not printed by Debug.

pub fn is_empty(&self) -> bool

true if the secret is empty.

Trait Implementations

impl<T: SealedPayload> ConstantTimeEq for SealedDynamic<T>

Available on crate feature ct-eq only.

Constant-time equality: opens both sides and compares the plaintext with subtle. Unequal lengths compare unequal without opening either side.

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

Performs equality comparison in constant time.

impl<T: SealedPayload> Debug for SealedDynamic<T>

Always prints [REDACTED]: no salt, no tag, no length.

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

Formats the value using the given formatter.

impl<T: SealedPayload> RevealScoped for SealedDynamic<T>

type Inner = T

The secret’s type as the closure sees it.

fn with_secret<F, R>(&self, f: F) -> R

where F: FnOnce(&T) -> R,

Calls f with a reference to the secret that cannot outlive the call.