# sec_protocol_metadata_access_supported_signature_algorithms(_:_:) ``` func sec_protocol_metadata_access_supported_signature_algorithms(_ metadata: sec_protocol_metadata_t, _ handler: @escaping (UInt16) -> Void) -> Bool ``` ## Parameters `metadata` A `sec_protocol_metadata_t` instance. `handler` A block to invoke one or more times, once per signature algorithm advertised by the peer. Each `signature_algorithm` is a TLS SignatureScheme codepoint (the on-the-wire 2-byte value) from the IANA “TLS SignatureScheme” registry — see RFC 8446 §4.2.3. ## Return Value Returns true if the supported signature list was accessible, false otherwise. ## Discussion \abstract Get the signature algorithms supported by the peer. Clients may call this in response to a challenge block. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)