# OpenSSLError The unified error type thrown by every `OpenSSL` Swift API. ``` enum OpenSSLError ``` ## Overview `OpenSSLError` is the single failure surface for this module. Each case carries a human-readable `String` that describes the specific failure condition; the string is surfaced verbatim by [`errorDescription`](/documentation/OpenSSL/OpenSSLError/errorDescription) to Foundation’s `LocalizedError` machinery, so it can be displayed in logs, alerts, or error UI without further processing. Instances are produced exclusively by this package’s Swift code — no raw `ERR_get_error()` C values bleed through. Equality compares the case *and* the associated `String`, which is convenient for tests but means the `String` contents are part of the observable API contract for those tests. > Note: Some cases are reserved for future API surface > (``doc://OpenSSL/documentation/OpenSSL/OpenSSLError/signingFailed(_:)``, > ``doc://OpenSSL/documentation/OpenSSL/OpenSSLError/verificationFailed(_:)``, > ``doc://OpenSSL/documentation/OpenSSL/OpenSSLError/invalidSignature(_:)``) and are not produced by any > code path shipping today. They exist so adding the corresponding > operations later is non-breaking for consumers who already pattern- > match on the full case list. > SeeAlso: ``doc://OpenSSL/documentation/OpenSSL/RSA/PrivateKey/init(pemRepresentation:)``, > ``doc://OpenSSL/documentation/OpenSSL/SHA256/SHA256Digest/init(rawValue:)``, > [Foundation `LocalizedError`](https://developer.apple.com/documentation/foundation/localizederror)