Enum Error 

#[non_exhaustive]
pub enum Error {
    NoPathFound,
    DepthExceeded,
    BudgetExceeded,
    MalformedIntermediate,
}

Errors returned by path building.

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.

NoPathFound

No valid path from the target certificate to any trust anchor was found.

DepthExceeded

A topologically valid path exists but requires more intermediates than the configured maximum (see PathBuilderConfig::max_depth, default DEFAULT_MAX_DEPTH).

BudgetExceeded

The internal DFS node-visit budget was exhausted in a single round.

This guards against adversarial certificate pools that would otherwise cause exponential search time. Each iterative-deepening round and the depth probe start with a fresh budget of DFS_BUDGET node visits.

MalformedIntermediate

Reserved for future diagnostic use. Path building no longer surfaces this variant: a candidate whose BasicConstraints extension is present but cannot be DER-decoded is silently skipped, just like candidates with cA = FALSE or no BasicConstraints extension at all. This skip-not-fail behaviour is required so that a single malformed certificate in a CMS SignedData.certificates bag (or any other unsolicited-cert pool) cannot poison verification of an otherwise-valid chain.

The variant is retained because Error is #[non_exhaustive] and a future diagnostic mode may want to surface decode failures explicitly. Build_path itself returns Error::NoPathFound when no chain can be built — including when the only available intermediates have a malformed BasicConstraints extension.

Trait Implementations

impl Clone for Error

fn clone(&self) -> Error

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

Available on crate feature std only.

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 Hash for Error

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Error

fn eq(&self, other: &Error) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Error

impl StructuralPartialEq for Error