Struct OsKeychainBackend 

pub struct OsKeychainBackend { /* private fields */ }

A KeychainBackend backed by the host OS credential store.

Construct with OsKeychainBackend::open, which returns None when no usable OS store exists on this host. The crate performs no fallback; the caller selects an alternative backend, as the example below does.

A storage location, not an access-control primitive: the crate’s own seal is the primary access control, so callers MUST NOT file plaintext secrets here. See the module docs for the per-platform access boundary and for why a machine/system service must not use this backend.

Example

use std::sync::Arc;
use dig_keystore::backend::{KeychainBackend, OsKeychainBackend, FileBackend, BackendKey};

// Prefer the OS credential store; fall back to a file backend elsewhere.
let backend: Arc<dyn KeychainBackend> = match OsKeychainBackend::open("dig-app") {
    Some(os) => Arc::new(os),
    None => Arc::new(FileBackend::new("/var/lib/dig/keys")),
};
backend.write(&BackendKey::new("identity"), b"...").unwrap();

Implementations

impl OsKeychainBackend

pub fn open(_service: impl Into<String>) -> Option<Self>

No OS credential store is used on this target (Linux / wasm) — always returns None. The crate performs no fallback; choosing another backend is the caller’s responsibility. See the module docs for why Linux is excluded as a custody primary.

Trait Implementations

impl Debug for OsKeychainBackend

Redacted Debug — never prints service, account, or secret material.

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

Formats the value using the given formatter.

impl KeychainBackend for OsKeychainBackend

fn read(&self, key: &BackendKey) -> Result<Vec<u8>>

Read the full contents of the blob at key.

fn write(&self, key: &BackendKey, data: &[u8]) -> Result<()>

Write data to key. Implementations should be atomic — a reader seeing the key after this call must see either the old bytes or the new bytes in full, never a torn mix.

fn delete(&self, key: &BackendKey) -> Result<()>

Remove the blob at key. Implementations should best-effort overwrite the storage before removing so residual disk sectors do not retain the ciphertext.

fn list(&self, prefix: &str) -> Result<Vec<BackendKey>>

List keys that start with prefix. Order is unspecified.

fn exists(&self, key: &BackendKey) -> Result<bool>

Whether a blob exists at key. Default impl delegates to read; backends with cheaper existence checks should override.