Enum Error 

#[non_exhaustive]
pub enum Error {
    InvalidKey(String),
    InvalidNonce(String),
    AuthenticationFailed,
    NotExtractable,
    Unsupported(String),
    NotPermitted(String),
    Other(String),
    Extension(ExtensionError),
    Read(Error),
    ShortWrite,
}

Errors surfaced by key creation and cryptographic operations.

Mirrors the WIT types.error variant (see the doc comments in wit/webcrypto.wit for the full contracts), plus Error::Read for failures of a caller-supplied DataSource producer. Misuse of the API is unrepresentable by construction — operations are one-shot calls on immutable key resources — and so has no variant here.

#[non_exhaustive]: this enum carries Error::Read in addition to the WIT cases, so it grows independently of the package’s own rule that a new types.error case is semver-major. The From conversion below is exhaustive over the WIT variant, so a case added there is a compile error here rather than a silent fallthrough.

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.

InvalidKey(String)

The supplied key material is invalid for the algorithm (for example, a wrong-length raw key, or one rejected by an implementation’s key-length policy). The string is human-readable.

InvalidNonce(String)

The supplied nonce is invalid for the algorithm (for example, a wrong-length AES-GCM nonce). The string is human-readable.

AuthenticationFailed

Verification failed: the MAC tag, the signature, or the ciphertext or its associated data did not verify under the key. Deliberately carries no detail, so implementations cannot leak why verification failed.

NotExtractable

The key was created with extractable false, so its material cannot be exported.

Unsupported(String)

The request was well-formed, but the implementation does not serve the requested algorithm parameters. The string is human-readable.

NotPermitted(String)

The key does not permit the requested operation: it was minted (or arrived from a platform keystore) with the operation’s usage disabled. The string names the refused operation.

Other(String)

An implementation-specific operational failure (an external keystore that cannot complete the operation, an input exceeding a buffering limit, …). The string is human-readable.

Extension(ExtensionError)

A named condition outside the WIT error variant’s closed set, identified by the (origin, name) pair — the only branchable identity; message is human-readable prose, never contract. Handle an unrecognized pair as Error::Other. Known pairs have constants in extension.

Read(Error)

A caller-supplied DataSource producer failed while being fed into the operation (see DataSource::from_reader). The operation’s own result is discarded: it was computed over a truncated input.

ShortWrite

The operation succeeded without accepting the whole source: the provider closed the stream’s read end early and then reported success. The stream-closure rule permits ending the input early only when the operation fails (a failing operation’s own error is what these wrappers report), so this indicates a defective provider, not a condition to retry.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

Renders the WIT cases case-name-first — invalid-key: <detail> — plus the Error::Read case this type adds.

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

Formats the value using the given formatter.

impl Error for Error

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.

impl From<Error> for Error

fn from(error: Error) -> Self

Converts to this type from the input type.