Enum CoapError 

pub enum CoapError {
    InvalidMessage(String),
    UnsupportedMethod(String),
    UnsupportedContentFormat(u16),
    BlockTransferError(String),
    DtlsError(String),
    PayloadTooLarge {
        size: usize,
        max: usize,
    },
    ResourceNotFound(String),
    Unauthorized(String),
    Forbidden(String),
    Internal(String),
}

Errors arising from CoAP/EST-coaps protocol handling.

Variants

InvalidMessage(String)

Malformed CoAP message (header, token, or option encoding).

UnsupportedMethod(String)

Unrecognized or unsupported CoAP method code.

UnsupportedContentFormat(u16)

Unrecognized CoAP Content-Format option value.

RFC 9148 §5.4 defines the content-format IDs that EST-coaps supports.

BlockTransferError(String)

Block-wise transfer failure per RFC 7959.

DtlsError(String)

DTLS session establishment or resumption failure.

RFC 9148 §5 requires DTLS to secure all EST-coaps exchanges.

PayloadTooLarge

Payload exceeds the configured maximum size.

Even with block-wise transfer, reassembled payloads are bounded to prevent resource exhaustion on constrained devices.

Fields

size: usize

Actual payload size in bytes.

max: usize

Configured maximum payload size in bytes.

ResourceNotFound(String)

No CoAP resource matches the requested URI path.

Unauthorized(String)

Client authentication required but not provided (4.01).

Returned when an EST operation requires mTLS client certificate authentication but no certificate was presented during the DTLS handshake.

Forbidden(String)

Authenticated client is not authorized for the request (4.03).

The peer authenticated successfully but the request is denied by an access-control policy — e.g. the EST enrollment-authorization check (NIAP CA PP FDP_ACF.1): the CSR names an identity the requester is not permitted to enroll. Distinct from Unauthorized, which means authentication itself is missing.

Internal(String)

Internal server error (catch-all).

Trait Implementations

impl Clone for CoapError

fn clone(&self) -> CoapError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CoapError

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

Formats the value using the given formatter.

impl Display for CoapError

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

Formats the value using the given formatter.

impl Error for CoapError

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.