Struct IvStash 

pub struct IvStash { /* private fields */ }

Remembers the IV used for each (plaintext, aad) pair so re-encrypting an unchanged value reproduces its exact previous ciphertext.

This is not an optimisation. sops edit decrypts, hands the tree to an editor, and re-encrypts everything; without the stash every line of the file changes on every edit, which destroys the property the whole format exists for — a readable, reviewable diff. Upstream calls it stash and keys it on exactly the same pair.

The security shape is worth stating rather than inheriting silently: two identical values at the same path reuse a nonce under one data key. Since the plaintexts are identical, GCM’s nonce-reuse failure reveals nothing an attacker did not already have (equal ciphertext for equal plaintext, which deterministic encryption concedes by construction). It is a knowing trade, not an oversight, and it is confined to unchanged values.

Implementations

impl IvStash

pub fn new() -> Self

pub fn remember(&mut self, plaintext: &Plaintext, aad: &Aad, iv: &[u8])

Record the IV a leaf was decrypted with, so an unchanged value keeps it.

pub fn recall(&self, plaintext: &Plaintext, aad: &Aad) -> Option<Iv>

The remembered IV for this pair, if any.

pub fn len(&self) -> usize

How many pairs are remembered. Diagnostics only.

pub fn is_empty(&self) -> bool

Trait Implementations

impl Debug for IvStash

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

The keys of this map are plaintexts. Printing the map would leak every value in the file, so Debug prints only the count.

impl Default for IvStash

fn default() -> IvStash

Returns the “default value” for a type.