# `RequestSeal.Digest.Error`
[🔗](https://github.com/baselabs/request_seal/blob/v0.5.2/lib/request_seal/digest/error.ex#L1)

Bounded digest failures without body, field, or algorithm input bytes.

  * `:mismatch` - a computed checksum differs from the field.
  * `:unsupported_algorithm` - no SHA-256/SHA-512 checksum can be checked, or a
    computation's algorithm list is not a nonempty unique list of `"sha-256"`
    and `"sha-512"`.
  * `:uncomputed_algorithm` - a stream did not hash a supported algorithm present
    in the field.
  * `:conflicting_digest` - a supported algorithm repeats across combined field
    occurrences, including identical checksums.
  * `:invalid_digest_length` - a known algorithm's checksum has the wrong size.
  * `:invalid_preference` - a preference weight is outside 0..10.
  * `:body_unavailable` - the body is streaming, unavailable, or consumed; this
    distinguishes missing bytes from retained empty content.
  * `:representation_required` - a representation check lacks explicit complete
    representation bytes.
  * `:invalid_field` - a preference selector other than the two RFC 9530
    preference field names.
  * `:invalid_body`, `:invalid_message`, `:invalid_kind`, `:invalid_chunk`,
    `:invalid_state`, and `:invalid_options` - invalid caller values. A
    `:max_bytes` above 16 MiB on `RequestSeal.Digest.compute/3` or
    `RequestSeal.Digest.check/3` returns `:invalid_options`.
  * `:limit` - content bytes exceed the `:max_bytes` bound.

Structured Fields errors retain their own bounded reason vocabulary
(`RequestSeal.StructuredFields.Error`); for example, an invalid Message given to
`RequestSeal.Digest.check_stream/3` or `RequestSeal.Digest.preferences/3`
returns that module's `:invalid_message`. No failure returns partial integrity
facts.

# `t`

```elixir
@type t() :: %RequestSeal.Digest.Error{reason: atom()}
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*