---
title: ASAuthorizationPublicKeyCredentialLargeBlobAssertionInput
framework: authenticationservices
role: symbol
role_heading: Structure
path: authenticationservices/asauthorizationpublickeycredentiallargeblobassertioninput-swift.struct
---

# ASAuthorizationPublicKeyCredentialLargeBlobAssertionInput

A type that represents input for the binary large object extension in passkey assertion requests.

## Declaration

```swift
struct ASAuthorizationPublicKeyCredentialLargeBlobAssertionInput
```

## Overview

Overview Use this type during assertion (sign-in) with an existing passkey. An app can specify exactly one operation to perform during the sign-in: either read the existing saved blob or write a new blob (overwriting the existing one, if applicable). This restriction mirrors the operations available in the WebAuthn specification.

## Topics

### Using assertion inputs

- [read](authenticationservices/asauthorizationpublickeycredentiallargeblobassertioninput-swift.struct/read.md)
- [write(_:)](authenticationservices/asauthorizationpublickeycredentiallargeblobassertioninput-swift.struct/write(_:).md)

### Inspecting the operation

- [operation](authenticationservices/asauthorizationpublickeycredentiallargeblobassertioninput-swift.struct/operation-swift.property.md)
- [ASAuthorizationPublicKeyCredentialLargeBlobAssertionInput.Operation](authenticationservices/asauthorizationpublickeycredentiallargeblobassertioninput-swift.struct/operation-swift.enum.md)

## See Also

### Creating an assertion input

- [init(largeBlob:prf:)](authenticationservices/aspasskeyassertioncredentialextensioninput-swift.struct/init(largeblob:prf:).md)
- [ASAuthorizationPublicKeyCredentialPRFAssertionInput](authenticationservices/asauthorizationpublickeycredentialprfassertioninput-swift.struct.md)