Enum BackendError 

#[non_exhaustive]
pub enum BackendError {
    AuthRequired,
    PinRequired,
    PinFailed(u32),
    PinBlocked,
    UserPinNotInitialized,
    ManagementKeyRequired,
    KeyNotFound(String),
    ObjectNotFound(String),
    SlotEmpty(String),
    CapacityExceeded,
    OperationNotPermitted(String),
    AttributeReadOnly(String),
    UnsupportedAlgorithm(String),
    UnsupportedOperation(String),
    TokenNotPresent,
    HardwareFailure(String),
    InvalidKeyFormat(String),
    InvalidData(String),
    NotFound(String),
    Configuration(String),
    Other(String),
}

Backend-specific errors.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

AuthRequired

Authentication required (not logged in).

PinRequired

PIN required to access backend.

PinFailed(u32)

PIN verification failed (wrong PIN). Contains remaining retries if known.

PinBlocked

PIN is blocked (too many failed attempts).

UserPinNotInitialized

User PIN not initialized (PKCS#11: C_InitPIN not yet called).

ManagementKeyRequired

Management key authentication required.

KeyNotFound(String)

Key not found in backend storage.

ObjectNotFound(String)

Object not found (PKCS#11: find_objects returned empty).

SlotEmpty(String)

PIV slot is empty (no key or certificate).

CapacityExceeded

Backend storage capacity exceeded.

OperationNotPermitted(String)

Operation not permitted (key usage flags don’t allow this).

AttributeReadOnly(String)

Attribute is read-only (e.g., tried to set CKA_ALWAYS_SENSITIVE).

UnsupportedAlgorithm(String)

Algorithm not supported by this backend.

UnsupportedOperation(String)

Operation not supported by this backend.

TokenNotPresent

Token not present in slot.

HardwareFailure(String)

Hardware failure (device disconnected, I/O error, etc.).

InvalidKeyFormat(String)

Invalid key format or data.

InvalidData(String)

Invalid data (malformed input, unexpected encoding, etc.).

NotFound(String)

Backend not found in registry.

Configuration(String)

Configuration error (missing or invalid settings).

Other(String)

Generic backend error.

Implementations

impl BackendError

pub fn retriability(&self) -> Retriability

Classify whether a step that failed with this error may be retried.

The match is exhaustive with no wildcard arm on purpose: adding a new BackendError variant fails to compile until it is deliberately classified here.

Trait Implementations

impl Debug for BackendError

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

Formats the value using the given formatter.

impl Display for BackendError

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

Formats the value using the given formatter.

impl Error for BackendError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.